Posts by Jai Ganesh

Jai Ganesh · Dark Discussions at Cafe Infinity

2446) Vincent du Vigneaud

Gist:

Work

The element sulfur plays an important role in some of the chemical compounds and processes that are the basis of all life. Vincent du Vigneaud studied sulfurous compounds, including oxytocin, a hormone that among other things plays a role in sexual intimacy and reproduction among people and mammals. In 1953 du Vigneaud succeeded in isolating the substance and determining its chemical composition. It became the first peptide hormone to have its sequence of amino acids determined. He also succeeded in producing oxytocin by artificial means.

Summary

Vincent du Vigneaud (born May 18, 1901, Chicago, Illinois, U.S.—died December 11, 1978, White Plains, New York) was an American biochemist and winner of the Nobel Prize for Chemistry in 1955 for the isolation and synthesis of two pituitary hormones: vasopressin, which acts on the muscles of the blood vessels to cause elevation of blood pressure; and oxytocin, the principal agent causing contraction of the uterus and secretion of milk.

Du Vigneaud studied at the University of Illinois at Urbana-Champaign, took a doctorate from the University of Rochester, New York (1927), and then studied at Johns Hopkins University, Baltimore, the Kaiser Wilhelm Institute, Berlin, and the University of Edinburgh. He headed the biochemistry department of the George Washington University Medical School, Washington, D.C. (1932–38), and was professor and head of the department of biochemistry at the Cornell University Medical College, New York City (1938–67), and professor of chemistry at Cornell University, Ithaca, New York (1967–75).

Du Vigneaud and his staff at Cornell helped identify the chemical structure of the hormone insulin in the late 1930s, and in the early 1940s they established the structure of the sulfur-bearing vitamin biotin. Later that decade, they isolated vasopressin and oxytocin and analyzed both those hormones’ chemical structure. Du Vigneaud found that the oxytocin molecule contains only eight different amino acids (nine amino acids in total, whereby a disulfide bond forms a link between two cysteines), in contrast to the hundreds of amino acids most other proteins contain. In 1953 he was able to synthesize oxytocin, becoming the first to achieve the synthesis of a protein hormone. In 1946 du Vigneaud and his colleagues at Cornell achieved another breakthrough, the synthesis of penicillin.

Details

Vincent du Vigneaud (May 18, 1901 – December 11, 1978) was an American biochemist. He was recipient of the 1955 Nobel Prize in Chemistry "for his work on biochemically important sulphur compounds, especially for the first synthesis of a polypeptide hormone," a reference to his work on the peptide hormone oxytocin.

Biography

Vincent du Vigneaud was born in Chicago in 1901. Of French descent, he was the son of inventor and mechanic Alfred du Vigneaud and Mary Theresa. He studied at the Schurz High School and completed secondary education in 1918. His interest in sulfur began when he entered high school and his new friends invited him to run chemical experiments on explosives using sulfur. During World War I, senior students were made to work on farms, and du Vigneaud worked near Caledonia, Illinois. There he became an expert in milking cows, which inspired him to become a farmer. However, his elder sister, Beatrice, persuaded him to take up chemistry at the University of Illinois at Urbana-Champaign, after which he enrolled in the chemical engineering course. He later recalled:

I found during the first year that it was chemistry rather than engineering that appealed to me most. I switched to a major in chemistry, since I was deeply impressed by the senior student's work, especially in organic chemistry. I also found that I was most interested in those aspects of organic chemistry that had to do with medical substances and began to develop an interest in biochemistry.

His interest was aroused by lectures of Carl Shipp Marvel and Howard B. Lewis, whom he remembered as being 'extremely enthusiastic about sulfur." With little support from the family, he found odd jobs to support himself. After receiving his MS in 1924 he joined DuPont.

He married Zella Zon Ford, whom he met on June 12, 1924, while working as a waiter during his university course. During the fall of 1924, Marvel found him a job as an assistant biochemist at the Philadelphia General Hospital that helped him to teach clinical chemistry at the Graduate School of Medicine, University of Pennsylvania. Marvel would pay for the trip to Pennsylvania in exchange for du Vigneaud's preparation of 10 pounds of cupferron. Resuming his academic career in 1925, du Vigneaud joined the group of John R. Murlin at the University of Rochester for his PhD thesis. He graduated in 1927 with his work The Sulfur of Insulin.

After a post-doctoral position with John Jacob Abel at Johns Hopkins University Medical School (1927–1928), he traveled to Europe as a National Research Council Fellow in 1928–1929, where he worked with Max Bergmann and Leonidas Zervas at the Kaiser Wilhelm Institute for Leather Research in Dresden, and with George Barger at the University of Edinburgh Medical School. He then returned to the University of Illinois as a professor.

In 1932, he started working at the George Washington University Medical School in Washington, D.C., and in 1938, he attended the Cornell Medical College in New York City, where he stayed until his emeritation in 1967. Following retirement, he held a position at Cornell University in Ithaca, New York.

In 1974, du Vigneaud had a stroke which forced his retirement. He died in 1978, one year after his wife's death in 1977.

Scientific contributions

Du Vigneaud's career was characterized by an interest in sulfur-containing peptides, proteins, and especially peptide hormones. Even before his Nobel-Prize-winning work on elucidating and synthesizing oxytocin and vasopressin via manipulating the AVP gene, he had established a reputation from his research on insulin, biotin, transmethylation, and penicillin.

He also carried out a series of structure-activity relationships for oxytocin and vasopressin, perhaps the first of their type for peptides. That work culminated in the publication of a book entitled A Trail of Research in Sulphur Chemistry and Metabolism and Related Fields.

Honours

Du Vigneaud joined Alpha Chi Sigma while at the University of Illinois in 1930. He was elected to the United States National Academy of Sciences and the American Philosophical Society in 1944, and the American Academy of Arts and Sciences in 1948. He received the 1955 Nobel Prize in Chemistry "for his work on biochemically important sulphur compounds, especially for the first synthesis of a polypeptide hormone," a reference to his work on the peptide hormone oxytocin.

Jai Ganesh · This is Cool

2509) Refrigerant

Gist

Refrigerants are chemical fluids (compounds) used in HVAC and refrigeration systems that alternate between liquid and gaseous states to absorb, transport, and release heat, thereby cooling spaces or items. Common types include Hydrofluorocarbons (HFCs like R-134a, R-410A) and increasingly, eco-friendly natural refrigerants like propane and CO2.

Refrigerant is the working fluid used in air conditioners, refrigeration, and heat pump systems. It is a chemical compound that changes temperature as it transitions between liquid and gas form – cooling as it vaporizes, and heating up as it condenses.

Summary

Refrigerants are working fluids that carry heat from a cold environment to a warm environment while circulating between them. For example, the refrigerant in an air conditioner carries heat from a cool indoor environment to a hotter outdoor environment. Similarly, the refrigerant in a kitchen refrigerator carries heat from the inside the refrigerator out to the surrounding room. A wide range of fluids are used as refrigerants, with the specific choice depending on the temperature range needed and constraints related to the system involved.

Refrigerants are the basis of vapor compression refrigeration systems. The refrigerant is circulated in a loop between the cold and warm environments. In the low-temperature environment, the refrigerant absorbs heat at low pressure, causing it to evaporate. The gaseous refrigerant then enters a compressor, which raises its pressure and temperature. The pressurized refrigerant circulates through the warm environment, where it releases heat and condenses to liquid form. The high-pressure liquid is then depressurized and returned to the cold environment as a liquid-vapor mixture.

Refrigerants are also used in heat pumps, which work like refrigeration systems. In the winter, a heat pump absorbs heat from the cold outdoor environment and releases it into the warm indoor environment. In summer, the direction of heat transfer is reversed.

Refrigerants include naturally occurring fluids, such as ammonia, carbon dioxide, propane, or isobutane, and synthetic fluids, such as chlorofluorocarbons, hydrochlorofluorocarbons, or hydrofluorocarbons. Many older synthetic refrigerants have been banned to protect the Earth's ozone layer or to limit climate change. Some refrigerants are flammable or toxic, making careful handling and disposal essential.

Refrigerants, while strongly associated with vapor compression systems, are used for many other purposes. These applications include propelling aerosols, polymer foam production, chemical feedstocks, fire suppression, and solvents.

Chillers are refrigeration systems that have a secondary loop which circulates a refrigerating liquid (as opposed to a refrigerant), with vapor compression refrigeration used to chill the secondary liquid.[5] Absorption refrigeration systems operate by absorbing a gas, such as ammonia, into a liquid, such as water.

Details

Refrigerants are crucial for commercial refrigeration systems, responsible for cooling and preserving perishable items. With refrigerant regulations phasing out ozone-depleting refrigerants, such as R-22, many businesses are transitioning to more environmentally friendly options. Understanding the different types of refrigerants available for commercial use can help you make an informed decision when it comes to replacing your refrigerator or freezer.

What Is Refrigerant?

Refrigerant is a cooling agent that absorbs heat and leaves cool air behind when passed through a compressor and evaporator. It undergoes a continuous cycle of compression and expansion where the coolant fluctuates between a liquid or gas state as it goes through the thermodynamic process to transfer heat efficiently.

How Refrigerant Works

Here is how refrigerant cools the inside of refrigerators and the air for AC units:

1) The refrigerant begins as a liquid when it passes through the expansion device in your unit. It expands and cools due to the sudden drop in pressure causing it to turn into a gas.
2) As the gaseous refrigerant passes through the copper evaporator coil inside the unit, it absorbs the heat from the products inside.
3) The unit’s compressor then pulls the refrigerant gas and the absorbed heat away from the food products, increasing the pressure of the gas.
4) The hot, high-pressure refrigerant then passes through the condenser coils. As it does so, it radiates its heat into the atmosphere and cools back into a liquid.
5) The liquid refrigerant reenters the expansion device and the process begins again.

Types of Refrigerant

Common types of refrigerants include synthetic compounds like hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), and natural compounds like ammonia and carbon dioxide. Each type has its own unique ID number, properties, and environmental impact, making it important for businesses to choose the right refrigerant for their specific needs.

Because of the negative impact on the environment, there are refrigerant regulations in place that have listed a variety of banned refrigerant types that are being phased out and replaced with more environmentally friendly alternatives. A refrigerant’s environmental impact is measured by two main characteristics: Ozone Depletion Potential (ODP) and Global Warming Potential (GWP). ODP measures a refrigerant's impact on the ozone layer, while GWP assesses its contribution to global warming. Choosing refrigerants with lower ODP and GWP values can help businesses reduce their environmental footprint and comply with regulations aimed at mitigating climate change.

Additional Information

When we say “refrigerant” we mean a fluid that can easily boil from a liquid into a vapour and also be condensed from a vapour back into a liquid. This needs to occur again and again, continuously without fail.

An example of a refrigerant would be water. This is able to evaporate and condense and is easy and safe to use. It’s used in Absorption chillers as a refrigerant, you can find out more about this type of chiller by clicking here. The reason water isn’t typically used as a refrigerant in common air conditioning units is because there are specially made refrigerants designed specifically for this task, and these are able to perform much more efficiently.

Some of the more common refrigerants on the market ate R22, R134A and R410A, although the laws and regulations on refrigerants are tightening and many of these will be phased out in the long run. These common refrigerants all have extremely low boiling points compared to water. This allows it to evaporate into a vapour with very little thermal energy applied which means the refrigerant can extract heat more rapidly.

Lets look at how refrigerant moves around the system. We’ll start with the compressor as this is the heart of the system, it forces the refrigerant around each of the components within the refrigeration system. The refrigerant will enter as a saturated vapour and is a low temperature and low pressure. As the compressor pulls the refrigerant in, it rapidly compresses it, this forces the molecules together so the same amount of molecules fits into a smaller volume. The molecules are all constantly bouncing around and compressing them into a smaller space causes them to collide more often, as they collide they convert their kinetic energy into heat. At the same time, all the energy that is put in by the compressor is converted into internal energy within the refrigerant. This results in the refrigerant increasing in internal energy, enthalpy, temperature and pressure. You’ll know this if you’ve ever used a bike pump, the pump becomes very hot as the pressure increases.

The refrigerant now moves to the condenser. The condenser is where all the unwanted heat is rejected out into the atmosphere. This will include all the heat from the building as well as the heat from the compressor. When the refrigerant enters the condenser, it needs to be at a higher temperature than the ambient air around it, in order for the heat to transfer. The greater the temperature difference, the easier the heat transfer will be. The refrigerant enters as a superheated vapour at high pressure and temperature, it then passes along the tubes of the condenser. During this move, fans will blow air across the condenser (in an air cooled system) to remove the unwanted energy. Much like blowing a hot spoon of soup to cool it down. As the air blows across the tubes, it removes heat from the refrigerant. As the refrigerant gives up its heat it will condense into a liquid so by the time the refrigerant leaves the condenser it will be a completely saturated liquid, still at high pressure, but slightly cooler although it will have decreased in both enthalpy and entropy.

The refrigerant then makes its way to the expansion valve. The expansion valve meters the flow of refrigerant into the evaporator. In this example we’re using a thermal expansion valve which holds back refrigerant, creating a high and low pressure side. The valve will then adjust to allow some refrigerant to flow and this will be part liquid and part vapour. As it passes through it will expand to try and fill the void. As it expands the refrigerant reduces in pressure and temperature, just like if you hold a deodorant spray can and hold the trigger down. The refrigerant leaves the expansion valve at low pressure and temperature then heads straight into the evaporator.

The evaporator receives the refrigerant and another fan blows the warm air of the room across the evaporator coil. The temperature of the room air is higher than the temperature of the cool refrigerant this allows it to absorb more energy and boil the refrigerant completely into a vapour. Much like heating a pan of water, the heat will cause the water to evaporate into steam vapour and the vapour will carry the heat away, if you were to place your hand over the rising steam you will find it’s very hot. Although I wouldn’t recommend this and it can cause injury. Remember we looked earlier at the low boiling point of refrigerants, so room temperature air is enough to boil it into a vapour.

The refrigerant leaves the evaporator as a low temperature, low pressure vapour. The temperature only changes slightly which confuses many people, but the reason it doesn’t increase dramatically is because it is undergoing a phase change from a liquid to a vapour so the thermal energy is being used to break the bonds between the molecules but the enthalpy and entropy will increase and this is where the energy is going. The temperature will only change once the fluid is no longer undergoing a phase change.

1. The expansion valve relieves pressure and passes the refrigerant into the evaporator coil as a cold, low-pressure liquid.
2. As the refrigerant warms within the coil, it phases back into a gaseous state.
3. The cool gas is compressed and fed into the condenser coil as a hot, high-pressure gas.
4. As the hot, pressurized refrigerant cools within the condenser coil, it phases back into a warm liquid state.
5. This process triggers the air handler within your system to distribute the heated or cooled air throughout your home based on your thermostat settings.

Jai Ganesh · Jokes

Q: Why did the lemon stop rolling down the hill?
A: It ran out of juice.
* * *
Q: Why did the lemon go out with a prune?
A: Because she couldn't find a date.
* * *
Q: What do you call a dancing pie?
A: Lemon Merengue.
* * *
Q: Why do lemons wear suntan lotion?
A: Because they peel.
* * *
Q: What did lemon say to lime?
A: Nothing stupid, lemons don't talk!
* * *

Jai Ganesh · Dark Discussions at Cafe Infinity

Come Quotes - XVIII

1. I believe cats to be spirits come to earth. A cat, I am sure, could walk on a cloud without coming through. - Jules Verne

2. Luck has nothing to do with it, because I have spent many, many hours, countless hours, on the court working for my one moment in time, not knowing when it would come. - Serena Williams

3. I'd say it's been my biggest problem all my life... it's money. It takes a lot of money to make these dreams come true. - Walt Disney

4. All of my misfortunes come from having thought too well of my fellows. - Jean-Jacques Rousseau

5. When people see your personality come out, they feel so good, like they actually know who you are. - Usain Bolt

6. Our birth is but a sleep and a forgetting. Not in entire forgetfulness, and not in utter nakedness, but trailing clouds of glory do we come. - William Wordsworth

7. You do things when the opportunities come along. I've had periods in my life when I've had a bundle of ideas come along, and I've had long dry spells. If I get an idea next week, I'll do something. If not, I won't do a darn thing. - Warren Buffett

8. I've been lucky. Opportunities don't often come along. So, when they do, you have to grab them. - Audrey Hepburn.

Jai Ganesh · This is Cool

Hydrogen Peroxide

Gist

Hydrogen peroxide (H2O2) is a powerful, versatile oxidizing agent and antiseptic, commonly used at 3% concentration for treating minor skin wounds, mouth irritation, bleaching hair, and disinfecting surfaces. It acts as an antimicrobial by releasing oxygen to break down microorganisms, though it can damage healthy tissue.

Hydrogen peroxide is used as a versatile disinfectant, antiseptic, and bleaching agent for wound cleaning, surface sanitizing, laundry whitening, and hair lightening, while industrially it bleaches paper, treats wastewater, and aids in chemical synthesis, with uses also extending to food packaging and agriculture, but it should be used cautiously on skin to avoid damage.

Summary

Hydrogen peroxide is a chemical compound with the formula H2O2. In its pure form, it is a very pale blue liquid; however, at lower concentrations, it appears colorless due to the faintness of the blue coloration. The molecule hydrogen peroxide is asymmetrical and highly polarized. Its strong tendency to form hydrogen bond networks results in greater viscosity compared to water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3%–6% by weight) in water for consumer use and in higher concentrations for industrial use. Concentrated hydrogen peroxide, or "high-test peroxide", decomposes explosively when heated and has been used as both a monopropellant and an oxidizer in rocketry.

Hydrogen peroxide is a reactive oxygen species and the simplest peroxide, a compound having an oxygen–oxygen single bond. It decomposes slowly into water and elemental oxygen when exposed to light, and rapidly in the presence of organic or reactive compounds. It is typically stored with a stabilizer in a weakly acidic solution in an opaque bottle. Hydrogen peroxide is found in biological systems including the human body. Enzymes that use or decompose hydrogen peroxide are classified as peroxidases.

Details

Remember the days when a tumble off your bike inevitably led to a cotton ball dipped in hydrogen peroxide? If you’ve never been subjected to the sting, consider yourself lucky. And rest assured that healthcare experts no longer recommend using hydrogen peroxide for cuts and scrapes.

But it still has a lot of other uses around your home.

We asked family medicine physician Sarah Pickering Beers, MD, to explain how to use hydrogen peroxide safely — and when to leave it on the shelf.

What is hydrogen peroxide?

Hydrogen peroxide is water with an extra oxygen molecule (H2O2 instead of H2O). That extra boost of oxygen gives it serious cleaning and germ-killing power.

“The extra oxygen molecule kills bacteria,” Dr. Pickering Beers says. “It’s also what removes color from porous surfaces like fabric.” (In other words, it bleaches them.)

Is hydrogen peroxide safe?

Yes — but with limits. Hydrogen peroxide can be helpful for disinfecting and stain removal.

But don’t use it directly on your skin.

“Hydrogen peroxide has fallen out of favor as a wound cleanser,” Dr. Pickering Beers says. “It irritates the skin and can prevent the wound from healing. Essentially, it can do more harm than good.”

Instead, wash minor wounds with soap and water, pat dry and apply antibiotic ointment and a bandage.

It’s a similar story with acne. In the past, hydrogen peroxide may have been a suggested remedy for pimples, but it’s no longer recommended.

“It’s too irritating for skin and doesn’t stay active long enough to help with acne,” she explains. Opt for acne-fighters like salicylic acid or benzoyl peroxide instead. They penetrate your skin and fight acne-causing bacteria longer — and are gentler on your skin.

What is hydrogen peroxide used for?

Hydrogen peroxide can be used all over your home — from the bathroom to the fridge — as long as you use it safely.

Follow these precautions:

* Keep it out of reach of kids and pets. Hydrogen peroxide can be harmful if swallowed or spilled on skin in large amounts.
* Use gloves and ventilate the space. Peroxide can irritate your skin and eyes. And breathing it in can be harmful.
* If it stops bubbling when you use it, it’s expired. Pour it down the drain and replace it.
* Keep it in its original container or a dark spray bottle. Hydrogen peroxide breaks down over time, especially when exposed to light.
* Stick with 3% medical-grade peroxide. Stronger concentrations, like 35% food-grade peroxide, aren’t safe for home use. “Food-grade peroxide can be toxic if you inhale it or get it on your skin,” Dr. Pickering Beers warns.

With those ground rules covered, let’s clean up.

Cleaning and disinfecting

Hydrogen peroxide kills germs. Use a 50/50 mix of water and peroxide in a spray bottle to disinfect shared objects and surfaces, like:

* Counters
* Cutting boards
* Doorknobs
* Mirrors
* Garbage cans
* Refrigerators
* Sinks and bathtubs
* Toilets
* Toys

Spray, let sit for five minutes and rinse surfaces that touch food.

Washing produce

Want a cheap, chemical-free way to clean fruits and veggies?

Add 1/4 cup of peroxide to a large bowl or sink full of water. Soak your fruits and veggies, rinse them well and allow them to dry.

This method helps remove germs and pesticides — and may even help your produce last longer.

Removing household stains

Hydrogen peroxide is a natural bleach. It works great on white or off-white surfaces — but test a small area first. Like bleach, it can remove color, so avoid using it on colored fabrics.

Try it on:

* Carpet stains: Spray on white carpet and blot gently.
* Clothing stains: Soak white clothes in a mix of water and 1 cup of peroxide for 30 minutes. Or add peroxide to your washer’s bleach compartment.
* Grout: Spray on white tile grout, let it sit, then scrub.
* Cookware: Sprinkle baking soda on ceramic pots and pans, spray with peroxide, let sit 10 minutes and rinse.

Cleaning beauty tools

Hydrogen peroxide isn’t a skin care product, but you can use it to sanitize tools, like your:

* Nail clippers
* Tweezers
* Eyelash curlers
* Nails

Noticing yellow or discolored fingernails? Or did opting for midnight blue during your last mani-pedi leave your nails stained?

Soaking your nails in warm water and 3 tablespoons of peroxide for three minutes can brighten them up.

This method works best on natural nails. Don’t use it if you have cuts or broken skin around your cuticles, and stop if you notice irritation.

Teeth

Hydrogen peroxide is found in many over-the-counter teeth-whitening products. It can help lift stains, but use it with care.

“Talk to your dentist before trying whitening products,” advises Dr. Pickering Beers. “They can make your teeth more sensitive.”

You can also try gargling with diluted peroxide to kill everyday germs in your mouth. Or choose mouthwash that already contains peroxide (and probably tastes better). Just be sure not to swallow it.

You can also try using hydrogen peroxide to clean your toothbrush. Dip it in peroxide for five minutes to kill germs and rinse thoroughly with water. If you choose this method, be sure to change out the peroxide daily — and always replace your toothbrush at least every three to four months.

Bottom line

Hydrogen peroxide is a powerful cleaning solution — but it’s not for your body. So, if you haven’t already, it’s time to move your brown bottle of bubbly stuff from the medicine cabinet and find it a new home with the cleaning supplies.

Additional Information

Hydrogen peroxide is a colorless liquid at room temperature with a bitter taste. Small amounts of gaseous hydrogen peroxide occur naturally in the air. Hydrogen peroxide is unstable, decomposing readily to oxygen and water with release of heat. Although nonflammable, it is a powerful oxidizing agent that can cause spontaneous combustion when it comes in contact with organic material. Hydrogen peroxide is found in many households at low concentrations (3-9%) for medicinal applications and as a clothes and hair bleach. In industry, hydrogen peroxide in higher concentrations is used as a bleach for textiles and paper, as a component of rocket fuels, and for producing foam rubber and organic chemicals.

Hydrogen peroxide, aqueous solution, stabilized, with more than 60% hydrogen peroxide appears as a colorless liquid. Vapors may irritate the eyes and mucous membranes. Under prolonged exposure to fire or heat containers may violently rupture due to decomposition. Used to bleach textiles and wood pulp, in chemical manufacturing and food processing.

Hydrogen peroxide, aqueous solution, with not less than 20% but not more than 60% hydrogen peroxide (stabilized as necessary) appears as colorless aqueous solution. Vapors may irritate the eyes and mucous membranes. Contact with most common metals and their compounds may cause violent decomposition, especially in the higher concentrations. Contact with combustible materials may result in spontaneous ignition. Prolonged exposure to fire or heat may cause decomposition and rupturing of the container. Used to bleach textiles and wood pulp, in chemical manufacturing and food processing.

Hydrogen peroxide solution is the colorless liquid dissolved in water. Its vapors are irritating to the eyes and mucous membranes. The material, especially the higher concentrations, can violently decompose in contact with most common metals and their compounds. Contact with combustible materials can result in spontaneous ignition. Under prolonged exposure to fire or heat containers may violently rupture due to decomposition of the material. It is used to bleach textiles and wood pulp, in chemical manufacturing and food processing.

Hydrogen peroxide, stabilized appears as a crystalline solid at low temperatures. Has a slightly pungent, irritating odor. Used in the bleaching and deodorizing of textiles, wood pulp, hair, fur, etc. as a source of organic and inorganic peroxides; pulp and paper industry; plasticizers; rocket fuel; foam rubber; manufacture of glycerol; antichlor; dyeing; electroplating; antiseptic; laboratory reagent; epoxidation; hydroxylation; oxidation and reduction; viscosity control for starch and cellulose derivatives; refining and cleaning metals; bleaching and oxidizing agent in foods; neutralizing agent in wine distillation; seed disinfectant; substitute for chlorine in water and sewage treatment.

Hydrogen peroxide is the simplest peroxide with a chemical formula H2O2. Hydrogen peroxide is an unstable compound in the presence of a base or catalyst, and is typically stored with a stabilizer in a weakly acidic solution. If heated to its boiling point, it may undergo potentially explosive thermal decomposition. Hydrogen peroxide is formed in the body of mammals during reduction of oxygen either directly in a two-electron transfer reaction. As a natural product of metabolism, it readily undergoes decomposition by catalase in normal cells. Due to its potent and broad-spectrum antimicrobial actions, hydrogen peroxide is used in both liquid and gas form for preservative, disinfection and sterilization applications as an oxidative biocide. It is used in industrial and cosmetic applications as a bleaching agent. Hydrogen peroxide is also considered as a generally recognized as safe compound by the FDA; it is used as an antimicrobial agent in starch and cheese products, and as an oxidizing and reducing agent in products containing dried eggs, dried egg whites, and dried egg yolks.

Hydrogen Peroxide is a peroxide and oxidizing agent with disinfectant, antiviral and anti-bacterial activities. Upon rinsing and gargling or topical application, hydrogen peroxide exerts its oxidizing activity and produces free radicals which leads to oxidative damage to proteins and membrane lipids. This may inactivate and destroy pathogens and may prevent spreading of infection.

Uses of Hydrogen Peroxide

* Industrial peroxide is mostly used in medicine and is a bleaching agent in our everyday life. About 30% of peroxide is used as a bleaching agent for textiles, paper, pumps, lather, and oil industries.
* A large quantity of about 33% uses in the manufacture of borax, epoxides, propylene oxide, and other chemicals.
* In environmental science, peroxide is used in pollution control during the treatment of sewage cleanup and waste.
* It uses as a mild antiseptic to prevent the small cuts, and buns on the skin.
* Hydrogen peroxide is also used as a mouth rinse in medicine to the freshness or as a mouth cleaner.

hydrogen-peroxide-formula-H2O2-structure-production-facts-and-uses.png

Jai Ganesh · Science HQ

Kidney Function Test

Gist

Kidney function tests (KFT) are blood and urine analyses, including eGFRcreatinine, and BUN, designed to evaluate how efficiently your kidneys filter waste and maintain fluid balance. These tests are vital for detecting early-stage chronic kidney disease (CKD), particularly in those with diabetes or hypertension. Normal eGFR is >90 mL/min/1.73 m².

The main kidney function tests involve blood and urine analysis to check how well kidneys filter waste, primarily measuring Creatinine, Blood Urea Nitrogen (BUN), and calculating the Estimated Glomerular Filtration Rate (eGFR) from a blood test, alongside urine tests for albuminuria (protein) and other abnormalities, with imaging scans sometimes used for structural issues.

Summary

Kidney function test is any clinical and laboratory procedure designed to evaluate various aspects of renal (kidney) capacity and efficiency and to aid in the diagnosis of kidney disorders. Such tests can be divided into several categories, which include (1) concentration and dilution tests, whereby the specific gravity of urine is determined at regular time intervals following water restriction or large water intake, to measure the capacity of the kidneys to conserve water, (2) clearance tests, which give an estimate of the filtration rate of the glomeruli, the principal filtering structures of the kidneys (see inulin clearance), and overall renal blood flow (see phenolsulfonphthalein test), (3) visual and physical examination of the urine, which usually includes the recording of its physical characteristics such as colour, total volume, and specific gravity, as well as checking for the abnormal presence of pus, hyaline casts (precipitation of pure protein from the kidney tubules), and red and white blood cells; proteinuria, the presence of protein in the urine, is often the first abnormal finding indicative of kidney disease, (4) determination of the concentration of various substances in the urine, notably glucose, amino acids, phosphate, sodium, and potassium, to help detect possible impairment of the specific kidney mechanisms normally involved with their reabsorption.

In addition to clinical and laboratory tests, the use of X-rays and radioisotopes is also valuable in the diagnosis of kidney disorders.

Details

Kidney function tests measure how efficiently your kidneys are working. Most of these tests check how well your kidneys clear waste from your blood. A kidney test may involve a blood test, 24-hour urine sample or both. You usually have your test results the same day or within a few days.

Overview:

What are kidney function tests?

Kidney function tests are urine (pee) and/or blood tests that evaluate how well your kidneys work. Your kidneys support your overall health by getting rid of waste and balancing body fluids and electrolytes. Most kidney function tests measure how well your glomeruli (glo-MARE-yoo-lye) work. Your glomeruli are tiny filters in your kidney that help clean your blood. The tests measure how efficiently glomeruli clear wastes from your blood.

Kidney function tests can make you feel a little anxious. It’s hard for some people to relax for a blood draw, and it can feel weird peeing into a cup and handing it over to a healthcare provider. But they’re an important tool in monitoring your kidney health. Providers understand these feelings and will do their best to make you feel comfortable.

Another name for kidney function tests is renal function tests.

What do your kidneys do?

Your kidneys are part of your urinary system. Most people have two kidneys. They typically sit in the back of your abdomen, below your ribcage on either side of your spine. They help your body filter waste products and remove them as pee.

Your kidneys are also important for producing:

* Hormones that regulate blood pressure
* Erythropoietin, which is important for red blood cell production; red blood cells carry oxygen throughout your body
* Vitamin D, which maintains bone and muscle health

Why might I need a kidney function test?

Some conditions, like diabetes or high blood pressure (hypertension), affect how well your kidneys work. If you have a condition that affects your kidneys, a healthcare provider may use kidney function tests to help monitor the condition and your overall kidney health.

You may also need a kidney function test if you have symptoms that may indicate kidney problems. These symptoms may include:

* Blood in your pee (hematuria)
* Foamy urine (may indicate proteinuria)
* Pain or burning when you pee (dysuria)
* Frequent urges to pee
* Peeing less than expected (oliguria)
* Problems starting to pee
* Body swelling (edema)
* Feeling very tired (fatigue)
* Nausea and vomiting
* Loss of appetite

What are the types of kidney function tests?

A healthcare provider may recommend one or more different types of kidney function tests. You may have blood tests for kidney function, such as:

* Blood urea nitrogen (BUN). This test measures nitrogen in your blood. Protein makes nitrogen when it breaks down.
* Estimated GFR (eGFR). Estimated Glomerular Filtration Rate (eGFR) : This test measures your filtration rates according to your protein levels, age, sex, height and weight.
* Serum creatinine. This test looks for creatinine buildup. When your muscle tissue breaks down, it creates the waste product creatinine.

A provider may also recommend 24-hour urine tests, including:

* Microalbuminuria. This test specifically looks for the protein albumin.
* Urinalysis. This test evaluates your pee for blood, proteins, urine acidity, specific gravity and the presence of tiny, tubelike particles (casts) and crystals.

Test Details:

How do I prepare for kidney function tests?

It depends on exactly what kind of kidney function test a healthcare provider recommends.

For some blood tests, you may need to:

* Avoid eating or drinking (fast) for several hours before the test. A provider will let you know if you need to fast.
* Moisturize your arms. Moisturizing can make it easier for a provider to insert the needle and acquire your blood sample.
* Let the provider know if you’re afraid of needles (trypanophobia). They can recommend coping strategies to make yourself as comfortable as possible during the blood test.

You usually don’t have to do anything to prepare for a urine test. Make sure you drink an extra glass of water before the test to ensure you can provide a sample that’s large enough for testing. It’s also a good idea to tell a provider if you’re currently getting your period (menstruating). The presence of menstrual blood and other vaginal discharge may affect your results.

What happens during a kidney urine test?

You complete 24-hour urine tests at home. A healthcare provider will give you a container to collect pee. On the day of the test:

* Pee into the toilet as usual after you first wake up.
* For the rest of the day, pee into the container.
* On day two, pee into the container when you first wake up.
* Complete the test by dropping your sample off at the provider’s office or lab.

What happens during a kidney blood test?

For a kidney blood test, you visit a healthcare provider’s office or a lab to give a blood sample. A provider who has blood-draw training (phlebotomist) uses a small needle and test tube to collect your blood sample — usually from a vein in your arm.

What can I expect after a kidney function test?

Kidney function tests are simple and rarely pose any long-term risks. But after blood tests, some people experience:

* Bruising
* Dizziness
* Feeling very tired

Call a provider if you have pain, fatigue or other symptoms that don’t go away.

Additional Information

Kidneys are a pair of bean-shaped organs located on the back side of the abdomen. The kidney filters the blood removing the waste products as urine from the body. It helps in the regulation of electrolytes like sodium, potassium and calcium. This regulation prevents diseases like high blood pressure, diabetes etc.

Nephrons are inside kidneys, tiny structures that filter the blood, help remove waste products, and restore essential elements like electrolytes, water and glucose into the bloodstream. Moreover, it removes certain waste products like drugs and excess ions into the rine. The kidney regulates urine concentration according to hydration and body needs.

If you are concerned about your kidneys, you have come to the right place, as this blog describes renal health and the KFT test in detail.

What is the KFT or Kidney Function Test?

KFT, or Kidney Functioning Test, as its abbreviated form describes, is a blood test to determine and evaluate kidney health. It measures several parameters, like calcium, potassium, creatinine, uric acid, chloride, sodium, blood urea, blood urea nitrogen, and phosphorus. The importance of this test is that it helps to assess proper functioning of the kidneys.

The blood and urine samples will determine your renal health, from work efficiency to how effectively the waste is excreted. It is a preventative test for chronic kidney disease. The sooner the kidney disease is diagnosed, the sooner its treatment will be, and you can easily divert major complications and life-threatening situations by changing your lifestyle.

What Different Tests in KFT Help to Determine Renal Health?

KFT test evaluates parameters such as creatinine, urea, and uric acid to diagnose inflammation, infection, or damage and detect kidney disease. Here are some different tests included in KFT test that reveals everything about your renal health:

Glomerular filtration rate

The Glomerular part of the kidney ensures that essential plasma proteins are retained in the blood, and the filtrate is passed on as urine. If there is kidney damage, the kidneys are inefficient in filtering the blood as fast as they should. Depending upon the results, the physician will categorize the test results in various stages and help identify the severity of kidney disease.

However, a GFR of 60 or higher indicates healthy renal health and that your kidneys are efficiently working. However, a GFR score of less than 60 indicates kidney disease, and if the score slips down to 15 or below, it might indicate kidney failure.

Blood Urea Nitrogen (BUN)

It measures the amount of nitrogen in your bloodstream. Nitrogen is a waste product eliminated by the kidney. High BUN levels are a sign that the kidneys are not working well. However, abnormal BUN levels don't need to require medical treatment. The high BUN levels can also indicate dehydration, a high protein diet, increasing age, and the effect of certain medications.

Serum Creatinine

Besides GFR, creatinine is another essential parameter that helps access renal health. It is a byproduct of energy metabolism produced during the working of muscles. The kidney removes this creatinine in urine. A healthy working kidney should have low creatinine and high GFR values. However, the presence of high levels of creatinine in the blood signifies the presence of kidney malfunction.

Uric Acid

Uric acid is normal body waste, which is produced by the breakdown of purine, a natural substance produced in the body. In healthy individuals, uric acid is excreted in the urine, but in the presence of kidney diseases, this urine accumulates in the blood. It is considered high when it is over 7 milligrams per deciliter for men and over 6 milligrams per deciliter for women.

The uric acid is considered less when it is less than 2 milligrams per deciliter. High and low uric acid levels are risky as high uric acid is associated with gout and kidney stones, and low uric acid is associated with neurological disorders and kidney stones.

Major Causes Affecting Renal Health

The two major factors that contribute to affect kidney health are:

* Type 1 and Type 2 Diabetes -
Prolonged high glucose levels damage the blood vessels in the kidneys leading to diabetic nephropathy.

* High Blood Pressure
High blood pressure weakens and damages the arteries around the kidneys with time, reducing the blood flow to the kidney tissue. The damaged tissues would not be able to filter the blood efficiently.

Signs And Symptoms to Get A KFT Test

Here are some signs indicating kidney problems, and the doctor might recommend a KFT test to evaluate the renal health:

* High blood pressure
* Diabetes
* Blood in urine
* Pain during urination
* Swelling in hand and feet
* Difficulty urinating
* Family history of kidney-damaging condition
* Old age (above 60)
* Smoking
* Obesity
* Frequent use of medication that can cause kidney damage.

Summing up,

Every organ in our body plays a fundamental role, and the kidney helps filter your blood and remove all the waste. The modern-lifestyle approaches and poor eating habits can affect renal health, eventually leading to chronic kidney disease or kidney failure.

One of the best ways to maintain kidney function is choosing healthy food choices, adequate sleep, regular exercise, and maintaining a healthy weight. However, it is better to get testing done to keep in tune with your body.

KFT tests can help to reveal your renal health, and you can take preventive measures to avoid complications.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#10775. What does the term in Biology Habituation mean?

#10776. What does the term in Biology Heredity mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#5971. What does the noun delusion mean?

#5962. What does the adjective deluxe mean?

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#2582. What does the medical term Hypercapnia mean?

Jai Ganesh · Jai Ganesh's Puzzles

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#9868.

Jai Ganesh · Jai Ganesh's Puzzles

Hi,

#6361.

Jai Ganesh · Exercises

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2722.

Jai Ganesh · Dark Discussions at Cafe Infinity

2445) Polykarp Kusch

Gist:

Work

In certain respects, electrons and atoms behave as if they were rotating charged particles that generate a magnetic field. Their magnetic moment provides a way of measuring how strongly they are affected by a magnetic field. Drawing upon quantum mechanics and relativity theory, Paul Dirac developed a theory for the interaction of charged particles with electromagnetic fields. Through precise measurements, Polykarp Kusch showed in 1947 that the electron’s magnetic moment was somewhat greater than the theory predicted. This became important for the further development of quantum electrodynamics.

Summary

Polykarp Kusch (born Jan. 26, 1911, Blankenburg, Ger.—died March 20, 1993, Dallas, Texas, U.S.) was a German-American physicist who, with Willis E. Lamb, Jr., was awarded the Nobel Prize for Physics in 1955 for his accurate determination that the magnetic moment of the electron is greater than its theoretical value, thus leading to reconsideration of and innovations in quantum electrodynamics.

Kusch was brought to the United States in 1912 and became a citizen in 1922. In 1937, at Columbia University, he worked with the physicist Isidor I. Rabi on studies of the effects of magnetic fields on beams of atoms. He spent the wartime years in research on radar and returned to Columbia in 1946 as professor of physics, a position he held until 1972. Among other posts held by Kusch at Columbia were department chairman (1949–52, 1960–63), director of the radiation laboratory (1952–60), and academic vice president and provost (1969–72). In 1972 he took a position as professor at the University of Texas, Dallas, where he remained until his retirement in 1982.

In 1947, through precise atomic beam studies, Kusch demonstrated that the magnetic properties of the electron were not in agreement with existing theories. Subsequently, he made accurate measurements of the magnetic moment of the electron and its behaviour in hydrogen. In work characterized by great accuracy and reliability, he measured numerous atomic, molecular, and nuclear properties by radio-frequency beam techniques.

Details

Polykarp Kusch (January 26, 1911 – March 20, 1993) was a German-American physicist who shared the 1955 Nobel Prize in Physics with Willis Eugene Lamb for his accurate determination that the electron magnetic moment was greater than its theoretical value, thus leading to reconsideration of and innovations in quantum electrodynamics.

Early life and education

Kusch was born in Blankenburg, Germany to John Mathias Kusch, a Lutheran missionary, and his wife, Henrietta van der Haas. In 1912, Kusch and his family had emigrated to the United States, where by 1922 he became a naturalized citizen. After graduating from grade school in the Midwest, Kusch attended Case Institute of Technology in Cleveland, Ohio (now known as Case Western Reserve University), where he majored in physics. After graduating from the Case Western Reserve University with bachelor of science degree in 1931, Kusch joined University of Illinois at Urbana–Champaign, from where he received his master's degree in 1933. He continued his education at the same alma mater, studying for his Ph.D. under mentorship from F. Wheeler Loomis and after defending his thesis titled "The Molecular Spectrum of Caesium and Rubidium", graduated from it in 1936. In 1935, prior to moving to the University of Minnesota, Kusch married his girlfriend, Edith Starr McRoberts. Together, they had three daughters.

Career

Kusch then moved to New York City, where from 1937 and until his departure for the newly founded University of Texas at Dallas, he spent much of his career as a professor at Columbia University, and served as the university's provost for several years. He worked on molecular beam resonance studies under I. I. Rabi, then discovered the electron anomalous magnetic moment. Many measurements of magnetic moments and hyperfine structure followed. He expanded into chemical physics and continued to publish research on molecular beams. During his tenure at Columbia, he was the doctoral supervisor for Gordon Gould, the inventor of the laser.

Kusch was a fellow of the American Physical Society since 1940 and of the American Academy of Arts and Sciences since 1959. He was elected a member of the National Academy of Sciences in 1956. In 1967, he was elected to the American Philosophical Society.

Kusch's wife Edith died in 1959, and in the following year he married Betty Pezzoni. They had two daughters. Kusch House, a residential dormitory for undergraduate students at Case Western Reserve University in Cleveland, Ohio on the South Campus, is named after Kusch. It is located on Carlton Road in Cleveland Heights. The University of Texas at Dallas has a Polykarp Kusch Auditorium with a plaque.

Kusch died on March 20, 1993, aged 82. His widow Betty died in 2003, aged 77.

Jai Ganesh · This is Cool

2508) Firefly

Gist

Light production in fireflies is due to the chemical process of bioluminescence. This occurs in specialized light-emitting organs (known as photophores), usually located on a female firefly's lower abdomen.

Summary

The Lampyridae are a family of elateroid beetles with more than 2,400 described species, many of which are light-emitting. They are soft-bodied beetles commonly called fireflies, lightning bugs, starflies or glowworms for their conspicuous production of light, mainly during twilight, to attract mates. The type species is Lampyris noctiluca, the common glow-worm of Europe. Light production in the Lampyridae is thought to have originated as a warning signal that the larvae were distasteful. This ability to create light was then co-opted as a mating signal and, in a further development, adult female fireflies of the genus Photuris mimic the flash pattern of the Photinus beetle to trap their males as prey.

Fireflies are found in temperate and tropical climates. Many live in marshes or in wet, wooded areas where their larvae have abundant sources of food. Although all fireflies nominally glow as larvae, only some species produce light in their adult stage, and the location of the light organ varies among species and between sexes of the same species. Fireflies have attracted human attention since classical antiquity; their presence has been taken to signify a wide variety of conditions in different cultures and is especially appreciated aesthetically in Japan, where parks are set aside for this specific purpose.

Firefly, (family Lampyridae) is a family of some 2,000 species of beetles (insect order Coleoptera) found in most tropical and temperate regions that have special light-producing organs on the underside of the abdomen. Most fireflies are nocturnal, although some species are diurnal. They are soft-bodied beetles that range from 5 to 25 mm (up to 1 inch) in length. The flattened, dark brown or black body is often marked with orange or yellow.

Some adult fireflies do not eat, whereas many feed on pollen and nectar. In a few species females are predatory on males of other firefly species. Both sexes are usually winged and luminous, although in some species only one sex has the light-producing organ. Females lacking wings and resembling the long, flat larvae are commonly referred to as glowworms. The larvae are sometimes luminescent before they hatch. Larvae live on the ground and feed on snails and slugs by injecting a fluid into their prey and then withdrawing the partly digested matter through hollow mouthparts. The common glowworm (Lampyris noctiluca) is a member of this family.

Most fireflies produce short, rhythmic flashes in a pattern characteristic of the species. The rhythmic flash pattern is part of a signal system that brings the sexes together. Both the rate of flashing and the amount of time before the female’s response to the male are important. Some authorities feel that the flashing is also a protective mechanism, reminding predators of the firefly’s bitter taste. However, some frogs eat such large numbers of fireflies that they themselves glow.

Firefly light is produced under nervous control within special cells (photocytes) richly supplied with air tubes (tracheae). Firefly light is a cold light with approximately 100 percent of the energy given off as light and only a minute amount of heat. Only light in the visible spectrum is emitted. Some tropical members of the coleopteran family Elateridae are also called fireflies.

The emitted light (due to a chemical process known as bioluminescence) of such organisms as fireflies, various marine organisms (see marine bioluminescence), and a number of algae, fungi, and bacteria is based on the oxidation of any of several organic molecules known as luciferins. The luciferins are broken down by the enzyme luciferase and react with the energy molecule ATP and oxygen, resulting in a glowing light.

Details

It’s a quiet, warm summer evening with no human in sight for miles in the woods. As the sun sets, tiny flashes of light start to flicker throughout the trees. At first there’s just a few, but soon hundreds of blinking lights are floating in the forest. Fireflies have come out for the evening.

Flying Beetles

Also known as lightning bugs, fireflies are beetles. Most fireflies are winged. That’s different from other light-producing insects of the same family, called glowworms. (Animals that produce light are called luminescent.)

There are about 2,000 firefly species. These insects often live in humid regions of Asia and the Americas, where they mostly feast on plant pollen and nectar. Firefly larvae—recently hatched worm-like fireflies that haven’t fully developed yet (including their wings)—feed on worms, snails, and insects.

You Glow, Guys!

Fireflies mostly use their light to “talk” to other fireflies and find a mate. They have special organs under their abdomens that take in oxygen. Inside special cells, they combine the oxygen with a substance called luciferin to make light with almost no heat. They use this light, called bioluminescence, to light up the ends of their abdomen.

Each firefly species has its own unique flashing pattern. When a male firefly wants to communicate with a female firefly, he flies near the ground while he flashes his light every six seconds. Once he’s near the ground, a female can more easily tell if he’s from the same species as she is. (Most female fireflies can’t fly.) She answers his flashes by turning on her lights. Then the male finds her.

Predators, such as birds or toads, get a different message from these lights. Although they can easily spot fireflies by their glow, they rarely eat them. That’s because fireflies release drops of toxic, foul-tasting blood. Their flashing is a warning light to predators to stay away.

Lights Out?

Fireflies aren’t endangered, but scientists are worried about them. In recent years, fewer of the insects have been spotted during the summer. Pesticide use and loss of habitat have likely impacted the population, as has light pollution. Too much nighttime light can be harmful to wildlife, affecting their migration patterns and hunting abilities. For fireflies, light pollution interferes with their attempts to signal each other.

Scientists aren’t sure how much the firefly population has dropped since their small size makes them hard to tag and track. Plus an adult firefly's life span is just one to three weeks, which makes counting them difficult. Scientists are working on ways to better track and protect these insects.

Additional Information

Scientifically, fireflies are classified under Lampyridae, a family of insects within the beetle order Coleoptera, or winged beetles. There are estimated to be 2000+ firefly species spread across temperate and tropical zones all over the world.

Hear the word firefly or lightningbug, and what comes to mind? Warm summer nights? Flickering lights in the encroaching dark? Maybe soft grass underfoot, with children running about? Few species ignite such warm feelings of nostalgia as fireflies. These beacons of light are some of our most beloved insects, and no wonder. Their bioluminescence fills us with awe. Their very presence feels magical. Their light has inspired artwork, literature, dance, and music. Beyond their immense cultural value, they have played critical roles in scientific research and medicine, and they are integral components of healthy, thriving ecosystems.

Fireflies are cherished, but they are also declining. Anecdotal reports from around the globe describe fewer individuals being seen each year. And while long-term monitoring studies are scarce, some of the data we have are concerning. For example, based on assessments published on the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species, one in three assessed North American fireflies may be at risk of extinction. Researchers found that 14% of the assessed species were categorized as threatened, but this number may be much higher since nearly half of the assessed species are data deficient. There is an urgent need to study firefly populations more closely to fully understand their plight and ensure conservation efforts are effective.

Introduction

In many places the insects called fireflies are a familiar sight on summer nights. They are noticeable because they can produce flashes of light. Fireflies belong to the beetle family. They are also called lightning bugs.

Where Fireflies Live

There are about 2,000 species, or types, of firefly. They live in tropical and mild parts of the world. They generally like warm, humid areas, but some live in dry places.

Fireflies retire into the ground during the day. At night, they tend to flock to dark, open areas where their lights can be the most noticeable. The best time to see them is in the later evening hours on dry summer nights.

Physical Features

Adult fireflies range in size from 0.2 to 1 inch (5 to 25 millimeters) long. They have a soft, flattened body that is dark brown or black, sometimes with orange or yellow marks. Males have wings and are good fliers. Females either have short wings or no wings. The females without wings are often called glowworms. Young fireflies, which also have no wings, are also called glowworms.

Behavior

Fireflies produce light with special organs, or body parts, on the underside of the body. These organs make light by mixing chemicals with oxygen from the air. Fireflies make a certain series of flashes to attract a mate. When a possible mate sees the flashes, it returns the signal.

Life Cycle

Females die soon after laying eggs, which hatch into larvae within a few weeks. It takes larvae one or two summers to grow into adults. Larvae can glow, but much more faintly than adults and only for a few seconds at a time. Larvae eat tiny snails and slugs, but adult fireflies may not eat.

Jai Ganesh · Jokes

Q: What did the Bacon say to the Tomato?
A: Lettuce get together!
* * *
Q: What water yields the most beautiful lettuce heads?
A: Perspiration!
* * *
Q: What is a Honeymoon Salad?
A: Lettuce alone, with no dressing!
* * *
Q: What did the vegetables say to the Salad Dressing?
A: Lettuce all smile.
* * *
Q: What did the host of Top Chef say to the contestants?
A: Lettuce begin.
* * *
Q: What do you do with epileptic lettuce?
A: You make a seizure salad!
* * *

Jai Ganesh · Dark Discussions at Cafe Infinity

Come Quotes - XVII

1. 'Obama and Biden want to raise taxes by a trillion dollars.' Guess what? Yes, we do in one regard: We want to let that trillion dollar tax cut expire so the middle class doesn't have to bear the burden of all that money going to the super-wealthy. That's not a tax raise. That's called fairness where I come from. - Joe Biden

2. The time has come for us to draw the line. The time has come for the responsible leaders of both political parties to take a stand against overgrown Government and for the American taxpayer. - Richard M. Nixon

3. I have found out one thing and that is, if you have an idea, and it is a good idea, if you only stick to it you will come out all right. - Cecil Rhodes

4. This is my 20th year in the sport. I've known swimming and that's it. I don't want to swim past age 30; if I continue after this Olympics, and come back in 2016, I'll be 31. I'm looking forward to being able to see the other side of the fence. - Michael Phelps

5. You that would judge me, do not judge alone this book or that, come to this hallowed place where my friends' portraits hang and look thereon; Ireland's history in their lineaments trace; think where man's glory most begins and ends and say my glory was I had such friends. - William Butler Yeats

6. Come, gentlemen, I hope we shall drink down all unkindness. - William Shakespeare

7. We meet aliens every day who have something to give us. They come in the form of people with different opinions. - William Shatner

8. Doing is the great thing, for if people resolutely do what is right, they come in time to like doing it. - John Ruskin.

Jai Ganesh · This is Cool

Thermopile

Gist

A thermopile is an electronic device that converts thermal energy into electrical energy (voltage) using multiple thermocouples connected in series. By stacking thermocouples, it increases voltage output and sensitivity, allowing it to detect small infrared radiation changes or measure temperature differences. Common uses include contactless IR thermometers, gas fireplace flame safety sensors, and thermal energy harvesting.

Thermopiles are used for contactless temperature sensing. The function of a thermopile is to transfer the heat radiation emitted from the object to a voltage output. The output is in the range of tens or hundreds of millivolts. Thermopiles work as sensors or generators.

Summary

Details

A thermopile or a thermoelectric pile is a device that converts thermal energy into electrical energy. It is composed of several thermocouples connected usually in series or, less commonly, in parallel. Such a device works on the principle of the thermoelectric effect, i.e., generating a voltage when its dissimilar metals (thermocouples) are exposed to a temperature difference.

Operation

Thermocouples operate by measuring the temperature differential from their junction point to the point in which the thermocouple output voltage is measured. Once a closed circuit is made up of more than one metal and there is a difference in temperature between junctions and points of transition from one metal to another, a current is produced as if generated by a difference of potential between the hot and cold junction.

A thermopile usually consists of multiple thermocouples connected electrically in series and thermally in parallel, with junctions distributed between two isothermal regions. Each thermocouple produces a small voltage proportional to the temperature difference between its hot and cold junctions. By connecting many thermocouples, the voltages are summed, yielding an output that scales with both the temperature gradient and the number of junctions. Owing to their passive operation, thermopiles are widely used in non-contact infrared thermometry, energy harvesting, and process monitoring applications.

Thermopiles do not respond to absolute temperature, but generate an output voltage proportional to a local temperature difference or temperature gradient. The amount of voltage and power are very small and they are measured in milli-watts and milli-volts using controlled devices that are specifically designed for such purpose.

Applications

Thermopiles are used to provide an output in response to temperature as part of a temperature measuring device, such as the infrared thermometers widely used by medical professionals to measure body temperature, or in thermal accelerometers to measure the temperature profile inside the sealed cavity of the sensor. They are also used in heat flux sensors and pyrheliometers and gas burner safety controls. The output of a thermopile is usually in the range of tens or hundreds of millivolts. As well as increasing the signal level, the device may be used to provide spatial temperature averaging.

Thermopiles are also used to generate electrical energy from, for instance, heat from electrical components, solar wind, radioactive materials, laser radiation or combustion. The process is also an example of the Peltier effect (electric current transferring heat energy) as the process transfers heat from the hot to the cold junctions.

There are also the so-called thermopile sensors, which are power meters based on the principle that the optical or laser power is converted to heat and the resulting increase in temperature is measured by a thermopile.

Additional Information:

Thermopiles work as sensors or generators.

As a sensor, the thermopile is used to determine a relatively low temperature (compared with normal thermocouple operations). Applications for thermopile sensors include appliances such as microwave ovens, clothes driers, medical devices, automotive (car climate control, seat occupancy, blind spot alert, black ice detection), consumer products (printers, copiers, mobile phones) and many other applications.

A thermopile generator generates electrical energy from heat. A typical application is flame failure. In a gas water heater, gas fireplace or gas stove a thermopile generator produces voltage while a pilot light is lit. Once the pilot light is extinguished, the voltage drop triggers a valve shutting off gas supply to the appliance.

Jai Ganesh · Science HQ

Liver Function Test

Gist

Liver function tests (LFTs) are blood tests that measure enzymes, proteins, and substances produced or processed by the liver to assess its overall health, screen for infections (hepatitis), and monitor damage or disease. They commonly measure ALT, AST, ALP, bilirubin, and albumin. Elevated levels often indicate liver inflammation, damage, or bile duct issues.

Liver function tests (also called a liver panel) use a sample of your blood to measure several substances made by your liver.

The most common liver function tests measure:

* Albumin, a protein made in the liver.
* Total protein. This test measures the total amount of protein in your blood, which includes albumin and globulins. These proteins are mainly made in your liver.
* ALP (alkaline phosphatase), ALT (alanine transaminase), AST (aspartate aminotransferase), and GGT (gamma-glutamyl transferase). These are enzymes that are mainly made in your liver. Enzymes are proteins that speed up certain chemical reactions in your body.
* Bilirubin, a waste product your body makes when it breaks down old red blood cells. Your liver removes most of the bilirubin from your body.
* Lactate dehydrogenase (LDH), an enzyme found in most of the tissues in your body, but some of the largest amounts are found in your liver.
* Prothrombin time (PT), how long it takes your blood to clot. Prothrombin is a protein involved in blood clotting. It's made in your liver.

Some of these tests can show how well your liver is working and others can show whether your liver may be damaged by liver disease or injury. But liver function tests alone usually can't diagnose specific diseases. So, if your results are abnormal, you'll usually need other tests to find the exact cause.

Summary

Liver function tests are blood tests used to help find the cause of your symptoms and monitor liver disease or damage. The tests measure the levels of certain enzymes and proteins in your blood.

Some of these tests measure how well the liver is performing its regular functions of producing protein and clearing bilirubin, a blood waste product. Other liver function tests measure enzymes that liver cells release in response to damage or disease.

Irregular liver function test results don't always mean liver disease. A member of your health care team will typically explain your results and what they mean.

Why it's done

Liver function tests can be used to:

* Screen for liver infections, such as hepatitis.
* Monitor a disease, such as viral or alcoholic hepatitis, and determine how well a treatment is working.
* Look for signs of serious disease, particularly scarring of the liver, called cirrhosis.
* Monitor possible side effects of medicines.

Liver function tests check the levels of certain enzymes and proteins in your blood. Levels that are higher or lower than usual can mean liver problems. The pattern and degree of elevation of these tests along with the overall clinical picture can provide hints to the underlying cause of these problems.

Some common liver function tests include:

* Alanine transaminase (ALT). ALT is an enzyme found in the liver that helps convert proteins into energy for the liver cells. When the liver is damaged, ALT is released into the bloodstream and levels increase. This test is sometimes referred to as SGPT.
* Aspartate transaminase (AST). AST is an enzyme that helps the body break down amino acids. Like ALT, AST is usually present in blood at low levels. An increase in AST levels may mean liver damage, liver disease or muscle damage. This test is sometimes referred to as SGOT.
* Alkaline phosphatase (ALP). ALP is an enzyme found in the liver and bone and is important for breaking down proteins. Higher-than-usual levels of ALP may mean liver damage or disease, such as a blocked bile duct, or certain bone diseases, as this enzyme is also present in bones.
* Albumin and total protein. Albumin is one of several proteins made in the liver. Your body needs these proteins to fight infections and to perform other functions. Lower-than-usual levels of albumin and total protein may mean liver damage or disease. These low levels also can be seen in other gastrointestinal and kidney-related conditions.
* Bilirubin. Bilirubin is a substance produced during the breakdown of red blood cells. Bilirubin passes through the liver and is excreted in stool. Higher levels of bilirubin might mean liver damage or disease. At times, conditions such as a blockage of the liver ducts or certain types of anemia also can lead to elevated bilirubin.
* Gamma-glutamyltransferase (GGT). GGT is an enzyme in the blood. Higher-than-usual levels may mean liver or bile duct damage. This test is nonspecific and may be elevated in conditions other than liver disease.
* L-lactate dehydrogenase (LD). LD is an enzyme found in the liver. Higher levels may mean liver damage. However, other conditions also may cause higher levels of LD.
* Prothrombin time (PT). PT is the time it takes your blood to clot. Increased PT may mean liver damage. However, it also can be higher if you're taking certain blood-thinning drugs, such as warfarin.

Details

Liver function tests are blood tests that measure different substances produced by your liver, including proteins, enzymes and bilirubin. High or low levels of different substances can indicate different diseases.

Overview:

What are liver function tests?

Liver function tests are blood tests that measure different substances produced by your liver. These measurements give your healthcare provider important information about the overall health of your liver and how well it’s working. A liver panel will often measure several substances in one blood sample. It may include various enzymes, proteins and byproducts.

What are the five primary liver function tests?

The most common liver tests include:

* Liver enzymes test. Your liver enzymes include alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase * (GGT). These are elevated when there’s liver injury.
* Total protein test.A total protein test measures levels of protein in your blood. Your liver makes protein, and low protein levels may indicate that your liver isn’t functioning optimally.
* Bilirubin test. Bilirubin is a waste product that your liver deposits in bile.
* LDH test. Lactate dehydrogenase (LDH) is an enzyme found in many of your body’s tissues, including your liver.
* Prothrombin Time (PT) test. This test measures how long it takes for a sample of your blood to clot, a process that involves proteins that your liver produces.

These tests are all part of a routine blood panel called a comprehensive metabolic panel.

When are tests done to check liver function?

Your healthcare provider might want to check these values to screen you for possible hepatitis or other liver diseases. If they already know that you have liver disease, they might want to check how it’s progressing or whether a treatment is working. You may also have a liver test to monitor the side effects of certain medications that are known to affect your liver.

What kinds of things can a liver panel tell you?

Different values and ratios of different substances may tell your healthcare provider:

* If you have liver inflammation (hepatitis).
* Whether the inflammation is alcohol-related or nonalcoholic (metabolic).
* Whether you have a problem in your liver itself or in your bile ducts.
* If your liver function is impaired, and if so, how much.
* If your bile flow is impaired, and if so, how much.
* Whether your medications are affecting your liver, and if so, how much.

Test Details:

How do liver function tests work?

A healthcare provider draws a small amount of blood from a vein in your arm to test in the lab. They’ll look for abnormally high or low levels of different substances. Often, they’ll want to compare levels of different enzymes or proteins to each other. If the balance is off, that can help them understand better what may be going on in your liver.

What happens during the test?

You may have the test at a hospital or a specialized testing facility. Your healthcare technician will locate the vein in your arm that they’ll use to draw blood from and then clean the site. They may wrap your arm with a compression band to make your veins stick out. They’ll insert a small needle into your vein and draw blood into a vial. It only takes a few minutes.

What happens after?

Your technician will send your blood sample to a lab for analysis. The lab may be in the same facility or a different one. This may determine how fast your results come back. It may be a few hours or a few days. As long as you aren’t feeling lightheaded from the blood draw, you can go home now, resume your medications and have something to eat and drink.

Additional Information

* Liver function tests (LFTs) are blood tests that check how well your liver is working.
* They measure proteins, enzymes and other substances in your blood.
* LFTs can help find liver disease and liver problems, check their severity and monitor treatment.
* If your test results are abnormal, your doctor may recommend more tests.

Discuss the results of your LFT blood test with your doctor to understand what they mean for you.

What are liver function tests?

Liver function tests (LFTs) are common blood tests that check how well your liver is working. They measure different proteins, enzymes and other substances in your blood.

These tests help:

* find liver disease and liver problems
* check how severe any problems are
* track how well treatment is working

Your liver is a large organ in your abdomen. It helps your body by filtering harmful substances and breaking down medicines and alcohol. It also supports digestion, makes bile and produces important proteins and enzymes.

Liver function tests are also called hepatic function tests.

Different liver function tests

There are several liver function tests, including:

* alanine aminotransferase (ALT) — an enzyme that shows liver cell health
* albumin — a protein made by the liver that helps regulate fluids
* alkaline phosphatase (ALP) — an enzyme linked to bile flow and bone health, as well as made by the placenta during pregnancy
* aspartate aminotransferase (AST) — an enzyme that can indicate liver damage
* bilirubin — a substance that reflects bile production and excretion
* gamma glutamyl transferase (GGT) — an enzyme that can indicate liver stress
* total protein — the total amount of proteins in the blood, including albumin and globulins

What are proteins and enzymes?

Proteins are important building blocks in your body. Some proteins, such as albumin and globulins, help move nutrients, fight infections and balance fluids.

Enzymes are special proteins that speed up chemical reactions in your body. Liver enzymes, such as ALT and AST help break down substances and can show if your liver is damaged.

When are liver function tests used?

Your doctor may refer you for liver function tests to check for liver problems and monitor your liver health, especially if you:

* have or may have a liver condition or liver disease
* have or may have cirrhosis of the liver
* have or may have a hepatitis virus infection
* have signs of a biliary obstruction — a blockage in the bile ducts that stops bile from draining properly into your gut
* drink a lot of alcohol
* have a family history of liver disease
* take medicines that can affect your liver function

Your doctor might refer you for LFTs if you have symptoms such as:

* jaundice (yellowing of the skin or eyes)
* dark urine (wee) or light-coloured faeces (math)
* nausea and vomiting
* abdominal (tummy) pain or swelling
* itching

Where can I get a liver function test?

You usually need to go to a pathology collection centre with a referral from your doctor. Your doctor will recommend one near you.

Sometimes, your doctor will collect blood for testing in their clinic. Blood tests are also routinely done in hospitals.

Jai Ganesh · Jai Ganesh's Puzzles

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2721.

Jai Ganesh · Jokes

Q: What's Tiger Woods favorite brand of potato chips?
A: Lays.
* * *
Q: Why did the Oreo go to the dentist?
A: Because it lost its filling.
* * *
There are two types of people in this world: People who love pizza and liars.
* * *
Why do we cook bacon and bake cookies?
* * *
What's the best part of Valentines Day?
The day after when all the chocolate goes on sale.
* * *
Knock Knock.
Who's There?
Queso!
Queso who?
Queso mistaken identity.
* * *

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