The Significance Of Dextran In History

In the World War Ⅱ, soldiers injured on the battlefield often died of very low blood pressure before they could reach hospital. But there was a dramatic change when the Korean War happened. There was a miracle life saver around – dextran.

Dextran is a complex carbohydrate, that is, a chain of sugar molecules strung together. It is a white powder which does not dissolve in water. Instead it absorbs water and swells into a loose jelly. So how did it help in the Korean War?

When a soldier is injured, he loses a lot of blood very quickly. This leads to loss of electrolytes and oxygen, and a sharp drop in blood pressure, endangering his life. He needs a blood transfusion immediately. But he cannot just be given any blood. If the blood groups do not match, there can be terrible complications.

During World War II, doctors tried transfusing plasma. Plasma is blood without any cells in it. It does not cause complications, and can immediately push up the blood pressure and replenish electrolytes. However, plasma can spoil easily, so it must be kept in ice all the time. An in the battlefield, where do you store plasma?

That’s where dextran helps. It can be carried dry, quickly mixed with water and salt and transfused to the patient. It pushes up the blood pressure immediately, while the saline helps restores some electrolytes. The patient can then be carried to a hospital where he can receive a proper blood transfusion.

How dextran was discovered
Dextran is made by bacteria. It is found in a place where you wouldn’t like it to be – dental plaque! It’s also found in small amounts in curd, and a fermented drink called kefir. But what was needed was a way to make dextran in large amounts.

In the 1940s, Allene Jeanes was a scientist at the USA’s Northern Regional Research Lab. A soft drink company had sent her a sample of their product, which had mysteriously become thick and gooey. She soon found that a bacterium had converted the sugar in the soda to dextran. Perhaps the bacteria had come from some worker’s dental plaque!

She found that the bacterium could be grown in the lab. It could grow in a vat of sugar solution, and make lots of dextran. That was then purified, dried, and sent on to Korea. There it would help soldiers survive the journey from battlefield to hospital, where they could get healed completely.

The Korean War ended in 1953, leaving Korea divided into two countries. But there was a clear winner of that war – dextran.

New Type Of Plastics

Things made of plastic, from credit cards to spoons to bags, have become so common in our lives that we can hardly think of life without them. Yet all plastics are made from petroleum, which will run out in a few decades. What do we do next?

How plastics are made
All plastics are polymers, that is they are made of a molecule which is itself made of hundreds of small molecules. These units are called monomers. Polyethylene (used in plastic bags) is made from a monomer unit called ethylene. Similarly styrofoam (used in disposable cups and plates) is made from a unit called styrene. PVC, which is used to make things like buckets and even plastic doors, is made from units of vinyl chloride linked to each other by chemical bonds. All these units ultimately come from petroleum. But the reserves of petroleum are quite rare, and will run out in our lifetime.

Plastic from potatoes
Potatoes contain a lot of starch (cellulose), which can be used to make a plastic-like material quite easily and cheaply. This plastic is not very strong or long-lasting. It is also very easily broken down by bacteria (see an article about eco-friendly plastic here). But that makes it the ideal material for making disposable spoons, cups, plates etc. In fact many companies have already begun to do so, and they have given it a nice name too – Spudware!

Plastic from chicken feathers and soybeans
The circuit board you see on electronic devices is made of a light but durable plastic, on which tiny electronic circuits are soldered on. As computers, mobile phones and other electronic gadgets spread through the world, we’ll need millions of these feather-bean boards!

A team from Cornell University found another way to make plastic. They used orange peels, and another material that is becoming increasingly common in our atmosphere – carbon dioxide. Orange peels contain a chemical called limonene (the same thing that gives the orange-y smell). The team found that you can convert it to limonene carbonate, which could then be polymerised into a useful plastic called poly-limonene carbonate (PLC). This is in fact a de-polluting plastic, because to make it you need to remove CO2 from the air, rather than add to it.

We hope that you’ll be inspired to make something equally clever from materials lying around the house too!

What’s the reason of hospital smell?

Ever stepped into a hospital, and immediately noticed the curious smell? It’s not the smell of disease, but of a particular disinfectant that hospitals prefer to use. This disinfectant is iodoform.


Iodoform is a compound of carbon, hydrogen and iodine, with the formula CHI3. It is used in hospitals and clinics as a mild disinfectant for cleaning the floors of the wards, corridors etc. It is not as strong-smelling as other disinfectants, which may disturb patients.

It can also be used as an antiseptic for treating skin infections, sores, bruises, boils, burns etc. When applied on the skin, iodoform decomposes to release iodine. It is iodine which acts as the actual antiseptic, killing bacteria and fungi. Iodoform is also safer than other antiseptics if it is accidentally swallowed.

Decline in use

Nowadays, newer kinds of antiseptics and disinfectants are available. These kill bacteria, fungi, insect larvae and worms much more effectively than iodoform. They also do not smell at all. Therefore modern hospitals are switching over to these antiseptics. And example is cetrimide (commonly sold as Savlon).

However iodoform is still useful in drug factories, where it is used as an intermediate in making many kinds of drug molecules.

What is olanzapine?

Zyprexa, the brand name of olanzapine, is in a family of drugs called “atypical antipsychotics.” It is also sometimes used to help treat delusions associated with other mental conditions such as bipolar disorder. These are the only conditions approved of by the FDA for this drug.

Zyprexa works as both a sedative and a mood stabilizer by acting on chemistry within the brain. This can help a patient suffering from GAD to get needed rest. Ideally, Zyprexa is to be used in combination with talk therapy. It cannot cure anxiety all by itself. By being sedated and having the moods stay steady, the patient has a better chance to pay attention to the talk therapy and try out any suggestions.

Olanzapine is available in pill form and also can be used as an intramuscular injection. However, injections are usually only given in a hospital setting.
The medicine is available as either a regular or orally disintegrating tablet, according to the Mayo Clinic. Adult schizophrenic patients usually start off at about 5 to 10 mg per day and usually do not exceed 20 mg per day. Those with bipolar disorder will usually need 5 to 15 mg per day, though as much as 20 mg may be needed to treat manic episodes. Olanzapine should not be taken with food.

People may experience one or more of the following side effects: blurred vision, other changes in vision, bloating of the arms, hands, feet, lower legs or face, clumsiness, problems talking and difficulty swallowing. It will also greatly increase your appetite. This combination of not wanting to move but wanting to eat causes you to gain weight. The most common side effect is significant weight gain, even over 20 pounds in 3 months.

Expert Insight
Zyprexa can often greatly help people suffering from anxiety. It can help them relax, rediscover some joys in life and to regain a sense of humor. In your doctor’s mind, the need to help your mental health will often take precedence over the possibility of weight gain from Zyprexa. Always tell your doctor any strange symptoms you suddenly develop when taking Zyprexa. The use of a cane or support when standing up is greatly recommended, or else you may get dizzy.

NASA Improve Baby Food: Lots More Information

When you think of baby formula, you probably don’t think of NASA or a space craft. The lead scientific team that invented the original baby food formula spent time as researchers for NASA, and it was there that they first conceived of a nutritional supplement that is now called Baby Formula all over the world.

In fact they were not even looking at nutrition for astronauts, but at creating oxygen in space!

While NASA researchers were exploring the idea of using algae as a way to create oxygen in outer space through the process of photosynthesis, they made a few new discoveries. During the research phase, certain types of algae were found to contain a couple of essential fatty acids that are present in human breast milk — Docosahexaenoic acid and Arachidonic acid.

This accidental discovery was researched and refined for years and was finally put to use in baby formula.

Healthier nerves and eyesight for babies

Many baby formulas are now enriched with DHA(Docosahexaenoic acid, the CAS number is 6217-54-5) and ARA. The human body naturally produces both DHA and ARA, and it’s been found that direct consumption of the two fatty acids can help babies — particularly premature babies — in their development.

While long-term benefits haven’t been proven yet, it appears that in the short term, both visual and neural developments are benefactors of this algae-enriched ingredient. The additives have only been in use since 2002, and while they’ve been FDA approved, the regulatory body has asked that companies that sell baby formula containing DHA and ARA monitor the effects for long-term study.

Thanks to NASA’s research, savvy parents now seek out DHA- and ARA-enriched formulas for their pre-term and full-term infants.

Main Toxic Chemicals In Beauty Products

People, especially women, use beauty products to look better, but unfortunately sometimes the short-term look is not worth the long-term damage that such products can do to our skin. The Campaign for Safe Cosmetics has revealed that an average American uses about 10 personal care products — from lipsticks to moisturizers — each day that contain hundreds of harmful ingredients.

The Safe Cosmetics Act of 2010 replaces the outdated federal law that holds no clauses against the presence of harmful chemicals in beauty products. According to this act, the Food and Drug Administration is vested with the power to ensure that products for personal use do not include any harmful ingredients.

Alcohol acts as a poisonous solvent. It is also known as a denaturant, or a chemical that brings changes to the structure of other chemical components. Alcohol is used as an ingredient in color rinses for the hair, hand lotions, after shave lotions and fragrances. It can cause nausea, headache and vomiting, flushing as well as depression. Other effects brought about by alcohol are dryness of hair and skin and cracks and fissures on the skin. These cracks can further develop as breeding grounds for bacteria.

Sodium Lauryl Sulfate, abbreviated as SLS, is a common detergent found in everything from toothpastes to makeup. It is so powerful it is also found in automobile de-greasing solutions and commercial floor cleaners. This chemical can badly dry out skin, and becomes a carcinogen when mixed with some other common beauty product ingredients.

Diethanolamine and Triethanolamine
Diethanolamine (DEA) and Triethanolamine (TEA) are chemicals that react with cosmetic ingredients that contain nitrites to form nitrosamines. Most of the nitrosamines are carcinogenic, or, they can cause cancer. These toxins mostly affect the liver and kidneys. These chemical reactions occur during the manufacturing process and while the cosmetics are stored in their containers.

This chemical is known by several other names such as mineral oil jelly, liquid Vaseline and paraffinum. It is one of the main ingredients in baby oil and body lotion. It can cause the extraction of natural oils contained in the skin and bring about chapping and dryness. It is also known to cause premature aging and block the removal of harmful chemicals from the skin, thus causing acne and other skin problems.

Vitamin D2 For Bones In Body

Vitamin D2, or Ergocalciferol, is one of the most important forms of Vitamin D. Vitamin D is essential to humans for its ability to help with normal bone growth. Vitamin D2 is a fat-soluble sterol, which is an organic molecule that is found in plants and yeast. A vitamin D deficiency can lead to diseases like rickets in children and osteomalacia–softening of the bones–in adults.

In the 1920s, vitamin D2 was discovered through exposing invertebrates, such as fungi or plants, to ultraviolet. Pharmaceutical companies patented the process. Vitamin D2 is not made naturally in vertebrates, or animals with an internal skeletal system. Vitamin D2 is better than vitamin D3 at absorbing ultraviolet radiation. It is white in color and is not soluble in water but in organic solvents and vegetable oil.

Vitamin D2 helps ensures the absorption of calcium happens in the body producing healthy bones, teeth and to help fight high blood pressure. Vitamin D2 may also help in the fight against osteoporosis and autoimmune diseases. Rickets today is often due to problems with the body’s absorption of vitamin D, diseases of the liver and kidney, or conditions that alter calcium in the body.

The recommended dose for vitamin D2 is 5 micrograms daily. Most multivitamins have the recommended daily allowance of vitamin D included in them. Luckily, Vitamin D is available in plentiful supply, from natural sources that are inexpensive, and even free.

Much of this requirement can be fulfilled by eating small portions of fatty fish. Grandmothers recommended cod liver oil for years for a reason–it’s packed with vitamins. Just one tablespoon provides 1360 IU of vitamin D, more than three times the daily requirement for most adults. Eggs are nature’s perfect food. Besides being packed with protein and good fats, they’re also a good source of vitamin D. But it’s all in the yolk, so go with the whole egg to get 20 IU.

Recent studies have suggested that vitamin D2 is not as efficient as vitamin D3 in biological value and its use in multivitamins should stop. Because vitamin D2 is manufactured, its stability and longevity is questionable. This can lead to issues with toxicity and loss of vitamin D concentration over time.

Researchers develop method for creating artificial fingerprints

A trio of researchers at the National Institute of Standards and Technology (NIST) in Maryland has found a way to accurately recreate human fingerprints. The reason for doing so, the team writes in their paper published in the journal Analytical Methods, is to provide a means for testing fingerprints for other chemicals as part of forensics research efforts.

Scientists know that when people work with explosives or illegal substances such as drugs, tiny amounts of those substances are captured in the oils produced in the fingers and are subsequently left behind in fingerprints when those people touch something else. Forensic research has focused on ways to recreate the process in an artificial way to better understand what properties are involved so as to better understand what occurred before, during or after a crime has been committed.

Researchers at NIST are hoping to discover new analysis techniques that will reveal more information about a person who has left fingerprints at a crime scene. By recreating the process in a controlled way, it becomes possible to vary environmental conditions to see what impact they might have on prints that are left behind.

Previous attempts to create artificial fingerprints have revolved around inkjet printing techniques, but have failed due to the oily nature of the materials involved, principally, sebum, the oil that is actually found in human fingerprints. The new method developed by the team at NIST takes a different approach.

The team created a solution by dissolving sebum in heptane to cause it to liquefy, then added particles of an explosive material followed by polyisobutylene to force the particles to remain suspended in the solution. To apply the solution they built a device that has a pneumatically controlled piston inside of a tube with a ball on the end (similar to an ink pen) that allows a controllable amount of the solution to pass through when pressed against a surface. Upon application, the solvents evaporate leaving just the sebum with the suspended particles still in it. In refining the piston-ball configuration, the team has found that they were able to apply the material onto surfaces in pattern shapes that resemble human fingerprints.

Fact & Treatment of Hepatitis B

Hepatitius B is a serious disease that causes inflammation of the liver. Hepatitis B is the most common liver disease in the world.Hepatitis B is caused by the hepatitis B virus (HBV). Available alternative cures include herbal formulations, traditional Chinese medicine and homeopathic remedies.

Types of Hepatitis
According to Dr. Larry Altshuler in his book Balanced Healing, hepatitis A is contracted through contaminated food or water, or through contact with an infected person. About 99 percent of hepatitis A cases resolve themselves. Hepatitis B is a blood-borne illness most often caused by sexual contact, needle use and blood transfusion; approximately 10 percent of people with hepatitis B become chronic carriers. Hepatitis C is also a blood-borne illness and accounts for 16 percent of cases.

How Hepatitis is Spread
The best way to protect against transmission of the disease is to know how it is spread. Hepatitis is spread through an infected mother to her newborn child, sex with an infected partner, sharing needles and other personal items, such as toothbrushes, with an infected person and direct contact or exposure to blood of an infected person. You are also at risk if you travel to countries with high levels of Hepatitis infections. Guard against these situations and make sure to get tested for early detection of the disease.

Entecavir hydrate
is an oral antiviral drug used in the treatment of hepatitis B infection. Entecavir hydrate is a nucleoside analog (more specifically, a guanine analogue) that inhibits reverse transcription, DNA replication and transcription in the viral replication process. Entecavir hydrate is more efficacious than previous agents used to treat hepatitis B (lamivudine and adefovir). Entecavir hydrate is also indicated for the treatment of chronic hepatitis B in adults with HIV/AIDS infection. However, Entecavir hydrate is not active against HIV.For adults, if you feel that you are at risk for hepatitis then you should contact your physician and discuss getting the vaccine.

Dr. Altshuler recommends several Chinese formulations if previous steps do not improve your symptoms or if your liver enzymes remain elevated. He suggests contacting a practitioner qualified in Chinese herbal medicine to determine which formulas are best for your symptoms. Improvements should be noted within three to six weeks but for maximum benefit the treatment should probably be taken longer.

What Causes Stained Aluminum Frames?

If you’ve seen mom or dad cooking rice in an aluminium pressure cooker, you might notice they put a slice of lemon in the cooker. Aluminum, like other metals, is susceptible to corrosion, oxygen in the air, as well as airborne dust and dirt. Wonder why they do that? What would happen if the lemon wasn’t there?

Let’s Understand Aluminium
Aluminium is an interesting metal. It is easy to beat into shape (malleable), so engineers
like it a lot for building things. It’s also very light in weight because it isn’t dense. And it doesn’t react very easily, so things made from aluminium don’t corrode. That makes it quite the opposite of iron or steel, which are heavy and rust easily.

This makes it a good material to make aeroplanes and space shuttles. But it also makes it a good material to make kitchen utensils. An aluminium cooker won’t leak aluminium ions when boiling rice in it (whereas a steel* cooker will). But over time, the acids present in food can cause some corrosion.

Why it blackens
There are two kinds of aluminium cooking vessels. The cheap ones are made of metallic
aluminium. ‘Anodised’ aluminium vessels have a protective coating (see below), but they’re more expensive.

Rice and dal and most other foods are generally acidic in content. During cooking, the acid
in the food helps the oxidation of aluminium to insoluble oxides. These settle on the base of the vessel, forming a dull grey layer. This layer is not smooth, so it can trap dirt, caramel (from some burnt sugar in the food) and other stuff, forming a dark stain which is difficult to clean.

What we can do about it
You can beat it by putting a slice of lemon (or a spoonful of vinegar) in the cooker while
cooking. There are acetate, oxalate(such as Magnesium Oxalate) and citrate ions present in the lemon, which react with the aluminium oxides, forming compounds that dissolve in water. You can also use potassium hydrogen tartarate (cream of tartar) to remove stains. The same principle works for hard water.

Or you can buy a cooker made of ‘anodised’ aluminium. ‘Anodising’ is a method by which the surface of the aluminium is oxidised using an electric current. A thin film of aluminium oxide forms on the surface. This thin film is smooth, and clings very tightly to the vessel. The advantage is that it is easier to clean, and prevents further corrosion of the aluminium by the acids in food.

Cream Of Tartar In Kitchen


Why are tarts and pastries made in bakeries so much smoother than when we make them at home? That’s because they use a secret ingredient – cream of tartar.


Uses in the kitchen


Chemists have another name for cream of tartar – they call it potassium hydrogen tartarate. It is a white, sour-tasting crystalline powder, and has many uses in the kitchen.


When you beat egg white, it produces foam that traps air. This is what helps make pastry light and fluffy. But the foam can break up, so bakers add a pinch of cream of tartar. This prevents the foam from collapsing. This helps the pastry remain smooth throughout.


Cream of tartar has many other uses too. If you make sugar syrup (for use with gulab jamuns, rasgullas etc), add a pinch of cream of tartar. That will prevent the sugar from crystallizing out of the syrup. Mixed with potassium chloride, it can serve as a substitute for salt. This is useful for people who have high blood pressure and should not take sodium.


If you add a pinch while boiling vegetables, it helps them keep their colour. This is because vegetable pigments are very sensitive to changes in pH. Cream of tartar acts a buffering agent, i.e. it prevents the pH from changing.


What do you do if you run out of baking powder, and the shops are closed? You can make your own with baking soda and cream of tartar(also known as Potassium bitartrate). When baking a cake, you can add a pinch each of these powders and mix well. The two chemicals react to form carbon dioxide in the oven, which causes the dough to rise. Baking soda alone will not work, as it needs an acid to activate it.


Cleaning agent


Cream of tartar is also a good rust remover. To use it, mix it with hydrogen peroxide and apply it on metallic objects. You can mix it with vinegar and use that mix to clean copper or brass utensils.Isn’t it a good chemical to have around the house?

Light and air: Sunlight-driven CO2 fixation

The increased use of renewable energy sources, particularly sunlight, is highly desirable, as is industrial production that is as CO2-neutral as possible. Both of these wishes could be fulfilled if CO2 could be used as the raw material in a system driven by solar energy. Japanese researchers have now introduced an approach to this type of process in the journal Angewandte Chemie. Their method is based on a principle similar to natural photosynthesis.

The use of carbon dioxide as a source of carbon may be an attractive option for reducing the consumption of fossil feedstocks and improving the CO2 footprint of chemical products. The biggest obstacle in our way is the high stability of the CO2 molecule. One of the possibilities for jumping this hurdle is to use very high-energy molecules to react with CO2. The photosynthetic process in green plants provides an example of how this could work. This process takes place in two steps: the light reactions and the dark reactions. In the light reactions, the photosynthetic system captures photons and stores their energy in the form of energetic chemical compounds. These are subsequently used to drive the dark reactions that use CO2 as a carbon source to synthesize complex sugar molecules.

Researchers working with Masahiro Murakami at Kyoto University used the same principle to design their process. In this case, the first step is also a reaction driven by light. The action of UV light can convert the starting material, an α-methylamino ketone, to a very energetic molecule. This also works with sunlight, as the researchers found out. An intramolecular rearrangement with ring closure results in a molecule containing a ring made of three carbon atoms and one nitrogen atom. This type of ring is under a great deal of strain and is correspondingly reactive. This “light reaction” was coupled to a “dark reaction”: In the subsequent light-independent step, the highly energetic compound captures CO2 in the presence of a base. This forms a cyclic amino-substituted carbonic acid diester (such as Carboni cacid allyl ethyl ester and the CAS number is 108-32-7that could be useful as an intermediate for chemical syntheses.

The striking thing about this reaction scheme is that the technique is simple. Diffuse sunlight on cloudy days is enough to drive the process. The second step can be carried out in the same reaction vessel through simple addition of the base and heating to 60 °C. The yield is 83 %. In addition, the process is very adaptable because a wide variety of α-methylamino ketones can be used as starting materials.

How To Make Milk Powder?

Alomost all of us have known the taste of milk powder, whether dry or dissolved in milk. Do you know that as powder, milk can be preserved for years together? Let’s have a look into how it is made.

Drying Milk
The Italian explorer Marco Polo reported that the soldiers of Kublai Khan (the Emperor of
the Mongols in the 13th century) knew how to make milk powder. They would leave milk to dry in the hot sun of the Gobi desert till it became quite thick. When they needed milk, they would put some of the dry paste in water and dissolve it. Easy wasn’t it?

Nowadays, milk is dried quickly in factories. There are two ways. One is called ‘spray drying’. Milk is sprayed into a huge chamber, and heated air is blown from the other end. The droplets of the milk dry up very quickly in the hot air, and fall down. The powder can then be scraped off and packed into jars or sachets.

Another way is ‘drum drying’. In this, milk is sprayed onto huge drums, which are heated by electric current. The heat makes the water in the milk evaporate, and the powder stays behind on the drum. Drum-dried milk is often flaky and sticky, while spray dried milk is powdery and non-stick.

Buy a few sachets of milk powder of different brands. Ask your friends to join you in feeling and tasting the powder. Which brand was spray-dried and which was drum-dried?

Why dry milk (and anything)
All living things need water to survive. This is because water is the solvent in which most
chemicals dissolve – like vitamins(such as Nicotinic acid and the CAS numner is 59-67-6), amino acids, carbohydrates and minerals. The enzymes that convert the food we eat into energy work only in a wet environment. This is true for every living organism, including bacteria.

If you go to a village, you will see chillies, papads, fish, grapes (to make raisins) and other things left out to dry in the sun. In a dry environment, bacteria cannot grow and multiply. If you remove moisture from food and store it in water-tight and air-tight containers, it will last almost forever.

The Colombo Plan
In the 1950s, there were food shortages in many countries, including India. A group of 8
countries had a meeting in Colombo, Sri Lanka. Here they created a plan by which countries like Australia, New Zealand and Canada would supply milk and other food to countries which were short of them. Under this plan, a large amount of milk powder was shipped from New Zealand to India. The powder would be dissolved in water to make milk, which was then distributed to homes. This continued till the White Revolution, when India was able to overcome its shortages.

New injectable gels toughen up after entering the body

Gels that can be injected into the body, carrying drugs or cells that regenerate damaged tissue, hold promise for treating many types of disease, including cancer. However, these injectable gels don’t always maintain their solid structure once inside the body.

MIT chemical engineer Bradley Olsen and his his students have now designed an injectable gel that responds to the body’s high temperature by forming a reinforcing network that makes the gel much more durable, allowing it to function over a longer period of time.

However, a drawback of these materials is that after they are injected into the body, they are still vulnerable to mechanical stresses. If such stresses make them undergo the transition to a liquid-like state again, they can fall apart. “Shear thinning is inherently not durable,” Olsen says. “How do you undergo a transition from not durable, which is required to be injected, to very durable, which is required for a long, useful implant life?”

The MIT researchers designed their hydrogel to include a second reinforcing network, which takes shape when polymers attached to the ends of each protein bind together. At lower temperatures, these polymers are soluble in water, so they float freely in the gel. However, when heated to body temperature, they become insoluble and separate out of the watery solution. This allows them to join together and form a sturdy grid within the gel, making it much more durable.

The MIT team answered that question by creating a reinforcing network within their gels that is activated only when the gel is heated to body temperature (37 degrees Celsius). Shear thinning gels can be made with many different materials (including polymers such as polyethylene glycol, or PEG), but Olsen’s lab is focusing on protein hydrogels, which are appealing because they can be designed relatively easily to promote biological functions such as cellular adhesion and cell migration.

The researchers found that gels with this reinforcing network were much slower to degrade when exposed to mechanical stress and were significantly stiffer.

Another advantage of these gels is that they can be tuned to degrade over time, which would be useful for long-term drug release. The researchers are now working on ways to control this feature, as well as incorporating different types of biological functions into the gels.

The Common Konwledge About Essential Oils

Essential oils are used in many homemade products. They can be expensive, though, if purchased commercially. If you have a flower or herb garden, or use a lot of essential oils, then an economical choice is to make your own essential oils. When you open a bottle of rose or lavender scent, do you wonder how it came to be there? Let’s have a look at how the fragrance of a rose is trapped and bottled!

Essential Oils
You might have read an earlier article about what made perfumes smell nice. In this
article, we’ll have a look into the many steps of chemistry required to make a perfume from the original flowers.

Every flower or leaf has a few chemicals unique to it. For example, lemon leaves contain a chemical called limonene. This is the one that gives them the unique ‘lemon’ smell. The reason they smell is because they evaporate easily, and when they enter our nose, the nerves can detect them.

Used in aromatherapy, rose oil will lift your spirits and help combat depression and anger. Its calming effects are similar to lavender and chamomile and are sometimes found in combination with these other oils. Rose oil helps people with insomnia or who have trouble sleeping through the night. Such chemicals are called ‘essential oils’. They are oils because when liquid, they don’t mix with water. The word essential refers to the fact that they represent the ‘essence’ of the plant. Lemon wouldn’t seem lemony without limonene.

So how do we get them out?
Over hundreds of years, chemists have found ways and means to separate these essential oils
from their plants. Scientists like Al-Kindi and ibn Hayyan were among the first to describe methods.

A common method is steam distillation. You can try it with the help of your chemistry teacher. Set up a distillation apparatus. Get some flowers and crush them (you’ll need a lot). Put them on a steel net and put the net in the part where the water boils (but the water shouldn’t touch the flowers). Now you’re ready to start.

As the water boils, the steam will pass through the crushed flowers. The heat makes the essential oils in them evaporate. As the steam and the evaporated oil pass into the condensation chamber, they’ll cool back to water and oil. Keep this vessel overnight. The water and oil will separate, giving you a layer of oil on top.

Carefully collect the oil from the upper layer into a fresh bottle. You can add some alcohol to build up the volume. Now you’ve got a scent ready!

Ingredient in diarrhea medicine leads to new farm fertilizer

The search for a sustainable slow-release fertilizer—a key to sustaining global food production at a time of burgeoning population growth—has led scientists to an ingredient used in some diarrhea medicines. They describe use of the substance, attapulgite, as a “carrier” for plant nutrients in a report in ACS’ journal Industrial & Engineering Chemistry Research.

This study was carried out to develop a novel slow-release fertilizer, which is based on natural attapulgite (APT) clay as a matrix, guar gum (GG) as an inner coating, and guar gum-g-poly(itaconic acid-co-acrylamide)/humic acid (GG-g-P(IA-co-AM)/HA) superabsorbent polymer as an outer coating. The coated compound fertilizer granules with diameter in the range of 2–3 mm possess low moisture content and high mechanical hardness.

Boli Ni and colleagues explain that about half of the 150 million tons of fertilizer used worldwide every year goes to waste. That’s because most fertilizers release nutrients too fast for the crops to use. The rest can run off farm fields and create water pollution problems. Existing slow-release fertilizers have drawbacks. So Ni’s team turned to the environmentally friendly substance attapulgite, an inexpensive, nutrient-rich clay used for decades to treat diarrhea and for other applications. It once was an ingredient in the Kaopectate marketed in the United States. They also included guar gum, used in cosmetics and to thicken foods, and humic acid (its CAS number is 1415-93-6) from decayed plant material.

The report describes development and successful tests of a new fertilizer composed of those three ingredients. The experimental data and analysis in this study indicated that the product prepared by a simple route can effectively reduce nutrient loss in runoff or leaching, improve soil moisture content, and regulate soil acidity and alkalinity level.
The slow-release pellets were easy to prepare, reduced nutrient loss via runoff and
leaching, improved soil moisture content and regulated soil acidity and alkalinity. “All of the results indicate that it may be expected to have wide applications for sustainable development of modern agriculture,” the scientists say.

What Is Aqua Regia?

Sometimes you may have seen an old gold ornament at home that has got spots or other signs of age. Your parents may take it to a ‘polisher’ to get it cleaned and polished. But did you know that the polisher actually removes a layer of gold?

You may have seen the video on aqua regia – the chemical that can dissolve gold. Gold is a ‘noble metal’. That means it will not react with anything ordinarily. It was so named because it can dissolve the so-called royal, or noble metals, although tantalum, iridium, and a few other metals are able to withstand it. But in jewellery it is actually alloyed with copper or silver, which tarnish over time.

Aqua regia (Latin for “royal water”) is a highly corrosive, fuming yellow or red solution. The chemical is very powerful and can dissolve gold within minutes. That’s because the nitric acid and the hydrochloric acid in it act together (They cannot dissolve gold by themselves). The nitric acid converts a tiny amount of gold metal to gold ions. These ions react immediately with the chloride ions from the hydrochloric acid. This causes even more gold atoms to turn into gold ions, and the reaction speeds up.

You should not clean gold ornaments with aqua regia. Aqua regia dissolves gold, even though neither constituent acid will do so alone, because, in combination, each acid performs a different task. Sadly, many people use it, claiming to be ‘gold cleaners’ or ‘gold polishers’. However, they are not being honest with you. They dip your gold ornaments for a little while in a solution of aqua regia, rinse them with water and give them back to you. The gold looks new and polished.

In truth, the aqua regia (the CAS number is 8007-56-5) has actually eaten up a few top layers of the gold. It is so thin that you won’t notice. But in a day’s work, ‘polishing’ hundreds of ornaments for unsuspecting people, a ‘polisher’ may remove quite a few grams of gold. He can then precipitate the gold using sodium bicarbonate.

To clean gold jewellery, all you really need is hot water, some soap and a toothbrush. That’s because most stains on gold jewellery are just dirt, which will go off with soap (But don’t do this if there are gemstones in the ornament, for soap water can leave stains on them). If they persist however, it is best that you take your ornaments to a professional jeweller for polishing.

Understanding Antibiotic Resistance

Scientists at the University of Bristol, together with collaborators at the University of Aveiro, Portugal, have solved the structure of an enzyme that breaks down carbapenems, antibiotics ‘of last resort’ which, until recently, were kept in reserve for serious infections that failed to respond to other treatments.

Increasingly, bacteria such as E. coli are resisting the action of carbapenems by producing enzymes (carbapenemases) that break a specific chemical bond in the antibiotic, destroying its antimicrobial activity.

Carbapenemases are members of the group of enzymes called beta-lactamases that break down penicillins and related antibiotics, but it has not been clear why carbapenemases can destroy carbapenems while other beta-lactamases cannot.

Using molecular dynamics simulations, Professor Adrian Mulholland in the School of Chemistry and Dr Jim Spencer in the School of Cellular and Molecular Medicine, showed how a particular type of carbapenemase enzyme reorients bound antibiotic to promote its breakdown and render it ineffective.

“The recent appearance and spread of bacteria that resist carbapenems is a serious and growing problem: potentially, we could be left with no effective antibiotic treatments for these infections. The emergence of bacteria that resist carbapenems is therefore very worrying.”

In a study published in the Journal of the American Chemical Society (JACS), the scientists combined laboratory experiments with computer simulations to investigate how one particular type of carbapenemase recognises and breaks down antibiotics. In beta-lactamase (the CAS number is 9073-60-3 or 9001-74-5) that cannot break down carbapenems, this rearrangement cannot happen, and so the enzyme cannot break down the antibiotic. Knowing this should help in designing new drugs that can resist being broken down.

Dr Spencer said: “Combining laboratory and computational techniques in this way gave us a full picture of the origins of antibiotic resistance. Our crystallographic results provided structures which were the essential starting point for the simulations and the simulations were key to understanding the dynamic behaviour of the enzyme-bound drug.

“Identifying the molecular interactions that make an enzyme able to break down the drug, as we have done here, is an important first step towards modifying the drug to overcome bacterial antibiotic resistance.”

Chemist develops spray to detect poison oak’s toxic oil

The last time Rebecca Braslau got a bad case of poison oak, she found herself pondering the chemical structure of urushiol, the toxic oil in poison oak and its relatives, poison ivy and poison sumac (all species of Toxicodendron).

“I thought: I’m a chemist. I should be able to do something about this,” said Braslau, a professor of chemistry and biochemistry at the University of California-Santa Cruz. Now her lab has developed a spray that can be used to detect urushiol on clothes and equipment, and potentially on skin, allowing people to wash off the oil before it causes an itchy, blistering skin rash.

Exposure to tiny amounts of urushiol is enough to cause this allergic reaction in susceptible people, and about 70 percent of U.S. adults are clinically allergic to urushiol or would become allergic if exposed enough times. Although Braslau said she doesn’t think there are toxicity concerns with any of the components of the spray, toxicology tests would be required before it could be approved for use on the skin.

“Of course, it would be great if we could deactivate the oil, but just being able to see it is useful because then you can wash it off,” she said. “People can keep getting exposed from items with the oil on them. About 10 percent of firefighters have to take time off work due to poison oak, and some of that is from exposure to oil that gets on their equipment.”

Chemically, urushiol belongs to a class of compounds known as catechols, which have a characteristic ring structure. Urushiol has a long greasy tail or “sidechain” attached to the ring, and different mixtures of urushiols with slightly different sidechains are found in the various Toxicodendron species.

Braslau’s spray detects the catechol ring structure. It contains a mixture of compounds, including a “profluorescent” compound in which the fluorescence of a dye molecule is quenched, and reaction with urushiol allows the dye to light up.

The formula has been patented, but Braslau said more work is needed to make it into a marketable product. She is also interested in developing it into a technique to detect catecholamines, which include physiologically important molecules such as dopamine and epinephrine.

Braslau’s work on this project has not been funded by any major grants, aside from a small starter grant from her university. Her lab is continuing to do some work on it, mostly experimenting with different dyes. Developing it into a commercial product, however, will require an investor willing to fund additional research, she said.

How To Prevent Apples Turning Brown?

     You start eating an apple, and just then you friend calls you up about homework, and you’re speaking for hours together. When you come back to your apple, it’s gone brown all over. What happened?

Rusting in apples

The brown colour is because your apple has rusted! That’s because apples are rich in iron, which is present in all their cells. When you cut an apple, the knife damages the cells. Oxygen from the air reacts with the iron in the apple cells, forming iron oxides. This is just like rust that forms on the surface of iron objects. An enzyme called polyphenol oxidase (that’s present in these cells) helps make this reaction go faster.

If you cut a browned apple into two again, you’ll notice that the insides are still white. That’s because the cells inside were intact, and did not let oxygen enter right inside.

Lots of other fruits and vegetables also turn brown when cut. These include bananas, pears and even potatoes.

Keeping an apple from turning brownThere’s no harm in eating an apple that has turned brown, for the iron oxide will not affect you. But when you’re making a fruit salad or apple pie, the browning may make it look unattractive. Here are some things you can do to stop or slow the browning:

  1. Cut and keep the apples under water. This prevents air from reaching the iron. But it may cause some vitamins to leach into the water.
  2. Rub the cut apples with lemon juice. The acid in the lemon juice stops the polyphenol oxidase from working.
  3. If you’re making apple pie, you can dip the apples in boiling water for a few seconds and take them out. This is called blanching, and it stops the browning enzyme.
  4. You can add some salt to the apples; the salt stops the enzyme. Do this if you don’t mind the salt-and-sweet taste that will result.
  5. Keep the apple pieces in an airtight jar, or wrap them in cling wrap very tightly. This also stops air from getting to them.

And finally, the method we like the most. Turn your apple into apple juice. The iron oxide gives it the special golden-brown colour, and it’s a tastier way to consume an apple!