Posts about chemistry

Scientific Inquiry Leads to Using Fluoride for Healthy Teeth

This webcast, from the wonderful SciShow, explores how we discovered fluoride helps prevent tooth decay and how we then used that knowledge and finally discovered why it worked.

I love stories of how we learn for observing what is happening. We don’t always need to innovate by thinking up creative new ideas. If we are observant we can pick up anomalies and then examine the situation to find possible explanations and then experiment to see if those explanations prove true.

When working this way we often are seeing correlation and then trying to figure out which part of the correlation is an actual cause. So in this dental example, a dentist noticed his patients had bad brown stains on their teeth than others populations did.

After investigation the natural fluoridation of the water in Colorado Springs, Colorado, USA seemed like it might be an explanation (though they didn’t understand the chemistry that would cause that result). They also explored the sense that the discolored teeth were resistant to decay.

Even without knowing why it is possible to test if the conditions are the cause. Scientists discovered by reducing the level of fluoridation in the water the ugly brown stains could be eliminated (these stains took a long time to develop and didn’t develop in adults). Eventually scientists ran an experiment in Grand Rapids, Michigan and found fluoridation of the water achieved amazing results for dental health. The practice of fluoridation was then adopted widely and resulted in greatly improved dental health.

In 1901, Frederick McKay, a recent dental school graduate, opened a dental practice in Colorado Springs, Colorado. He was interested in what he saw and sought out other dentists to explore the situation with him but had little success. In 1909, he found some success when renowned dental researcher Dr. G.V. Black collaborate with him.
Dr. H. Trendley Dean, head of the Dental Hygiene Unit at the National Institute of Health built on their work when he began investigating the epidemiology of fluorosis in 1931. It wasn’t until 1945 that the Grand Rapids test started. Science can take a long time to move forward.

Only later did scientists unravel why this worked. The fluoride reacts to create a stronger enamel than if the fluoride is not present. Which results in the enamal being less easily dissolved by bacteria.
Health tip: use a dental stimudent (dental picks) or floss your teeth to maintain healthy gums and prevent tooth decay. It makes a big difference.

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How Corn Syrup Might Be Making Us Fat

How Corn Syrup Might Be Making Us Hungry–and Fat by Katherine Harmon

…Glucose lowered the activity of the hypothalamus but fructose actually prompted a small spike to this area. As might be expected from these results, the glucose drink alone increased the feelings of fullness reported by volunteers, which indicates that they would be less likely to consume more calories after having something sweetened with glucose than something sweetened with more fructose.

Fructose and glucose look similar molecularly, but fructose is metabolized differently by the body and prompts the body to secrete less insulin than does glucose (insulin plays a role in telling the body to feel full and in dulling the reward the body gets from food). Fructose also fails to reduce the amount of circulating ghrelin (a hunger-signaling hormone) as much as glucose does. (Animal studies have shown that fructose can, indeed, cross the blood-brain barrier and be metabolized in the hypothalamus.) Previous studies have shown that this effect was pronounced in animal models…

Most of the science indicates calories consumed is by far the dominant factor in weight gain. Different foods with the same calories can affect how hungry you feel. Thus the biggest factor in reducing weight gain seems to be reducing calories and one way to help is to eat food that leaves you feeling full and avoid foods that don’t.

The science is not completely clear though on whether certain diets can have a significant affect above and beyond calorie levels. I am skeptical of such claims, however. There are concerns beyond calories for healthy eating – getting a well balanced diet is important.

Healthy physical activity is also important. Burning off calories with exercise allows more consumption without weight gain. And exercise is important for health not just to avoid gaining weight.

Related: Researchers Find High-Fructose Corn Syrup Results in More Weight GainDoes Drinking Diet Soda Result in Weight Gain?Waste from Gut Bacteria Helps Host Control WeightModeling Weight Loss Over the Long TermHow Caffeine Affects Your Body

Solar Powered Water Jug to Purify Drinking Water

Deepika Kurup, a 14-year-old New York student, won the Discovery Education 3M Young Scientist Challenge for her invention of a solar-powered water jug that changes dirty water into purified drinking water. She won the top prize of $25,000.

During “the 5 minutes of my presentation 15 children have died from lack of clean drinking water.”

I am thankful we have kids like this to create solutions for us that will make the world a better place. We rely on hundreds of thousands of such people to use science and engineering methods to benefit society.

Related: Strawjet: Invention of the YearCheap Drinking Water From SeawaterWater and Electricity for AllThanksgiving, Appropriately (power of capitalism and people to provide long term increases in standards of living)

2012 Nobel Prize in Chemistry to Robert Lefkowitz and Brian Kobilka

The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry for 2012 to

  • Robert J. Lefkowitz, Howard Hughes Medical Institute and Duke University Medical Center, Durham, NC, USA
  • and Brian K. Kobilka, Stanford University School of Medicine, Stanford, CA, USA

for studies of G-protein–coupled receptors.

Your body is a fine-tuned system of interactions between billions of cells. Each cell has tiny receptors that enable it to sense its environment, so it can adapt to new situtations. Robert Lefkowitz and Brian Kobilka are awarded the 2012 Nobel Prize in Chemistry for groundbreaking discoveries that reveal the inner workings of an important family of such receptors: G-protein–coupled receptors.

For a long time, it remained a mystery how cells could sense their environment. Scientists knew that hormones such as adrenalin had powerful effects: increasing blood pressure and making the heart beat faster. They suspected that cell surfaces contained some kind of recipient for hormones. But what these receptors actually consisted of and how they worked remained obscured for most of the 20th Century.

Lefkowitz started to use radioactivity in 1968 in order to trace cells’ receptors. He attached an iodine isotope to various hormones, and thanks to the radiation, he managed to unveil several receptors, among those a receptor for adrenalin: β-adrenergic receptor. His team of researchers extracted the receptor from its hiding place in the cell wall and gained an initial understanding of how it works.

The team achieved its next big step during the 1980s. The newly recruited Kobilka accepted the challenge to isolate the gene that codes for the β-adrenergic receptor from the gigantic human genome. His creative approach allowed him to attain his goal. When the researchers analyzed the gene, they discovered that the receptor was similar to one in the eye that captures light. They realized that there is a whole family of receptors that look alike and function in the same manner.

Today this family is referred to as G-protein–coupled receptors. About a thousand genes code for such receptors, for example, for light, flavour, odour, adrenalin, histamine, dopamine and serotonin. About half of all medications achieve their effect through G-protein–coupled receptors.

The studies by Lefkowitz and Kobilka are crucial for understanding how G-protein–coupled receptors function. Furthermore, in 2011, Kobilka achieved another break-through; he and his research team captured an image of the β-adrenergic receptor at the exact moment that it is activated by a hormone and sends a signal into the cell. This image is a molecular masterpiece – the result of decades of research.

Related: More details on the research2011 Nobel Prize in Chemistry2009 Nobel Prize in Chemistry: the Structure and Function of the RibosomeThe Nobel Prize in Chemistry 2008

Science PhD Job Market in 2012

The too-big-to-fail-bank crisis continues to produce huge economic pain throughout the economy. Science PhDs are not immune, though they are faring much better than others.

U.S. pushes for more scientists, but the jobs aren’t there

Since 2000, U.S. drug firms have slashed 300,000 jobs, according to an analysis by consulting firm Challenger, Gray & Christmas. In the latest closure, Roche last month announced it is shuttering its storied Nutley, N.J., campus — where Valium was invented — and shedding another 1,000 research jobs.

Largely because of drug industry cuts, the unemployment rate among chemists now stands at its highest mark in 40 years, at 4.6 percent, according to the American Chemical Society, which has 164,000 members. For young chemists, the picture is much worse. Just 38 percent of new PhD chemists were employed in 2011, according to a recent ACS survey.

Two groups seem to be doing better than other scientists: physicists and physicians. The unemployment rate among those two groups hovers around 1 to 2 percent, according to surveys from NSF and other groups. Physicists end up working in many technical fields — and some go to Wall Street — while the demand for doctors continues to climb as the U.S. population grows and ages.

But for the much larger pool of biologists and chemists, “It’s a particularly difficult time right now,” Stephan said.

From 1998 to 2003, the budget of the National Institutes of Health doubled to $30 billion per year. That boost — much of which flows to universities — drew in new, young scientists. The number of new PhDs in the medical and life sciences boomed, nearly doubling from 2003 to 2007, according to the NSF.

The current overall USA unemployment rate is 8.2%.

The current economy doesn’t provide for nearly guaranteed success. The 1960’s, in the USA, might have come close; but that was a very rare situation where the richest country ever was at the prime of economic might (and even added on top of that science was seen as key to promote continued economic success). Today, like everyone else (except trust fund babies), scientists and engineers have to make their way in the difficult economy: and that should be expected to be the case in the coming decades.

Right now, physicians continue to do very well but the huge problems in the USA health system (we pay double what other rich countries do for not better outcomes) make that a far from a certain career. They likely will continue to do very well, financially, just not as well as they have been used to.

Science and engineering education prepare people well for economic success but it is not sufficient to guarantee the easy life. Just like everyone else, the ability to adapt to current market conditions is important in the current economic climate – and will likely continue to be hugely important going forward.

The reason to get a undergraduate or graduate science or engineering education is because you are interested in science and engineering. The economic prospects are likely to continue to be above average (compared to other education choices) but those choosing this path should do so because they are interested. It makes sense to me to factor in how your economic prospects will be influenced by your choices but no matter what choices are made a career is going to take hard work and likely many frustrations and obstacles. But hopefully a career will provide much more joy than hardship.

Related: Career Prospect for Engineers Continues to Look PositiveAnother Survey Shows Engineering Degree Results in the Highest PayThe Software Developer Labor Market

The Chemistry of Fireworks

The video features John A. Conkling, Ph.D., who literally wrote the book on fireworks — he is the author of The Chemistry of Pyrotechnics.

The earliest documentation of fireworks dates back to 7th century China.

A Syrian named Hasan al-Rammah wrote of rockets, fireworks, and other incendiaries, using terms that suggested he derived his knowledge from Chinese sources, such as his references to fireworks as “Chinese flowers”.

Chinese fireworks began to gain popularity around the mid-17th century.

Related: Cooking with Chemistry, Hard CandyThe Chemistry of CookingVideo of Briggs-Rauscher Oscillating Chemical Reaction

Good Chemistry: A Love Song for Ionic Bonds

Song and video by 10th grade student, Eli Cirino, for extra credit in his chemistry class.

An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. Ionic bonds are formed between a cation, which is usually a metal, and an anion, which is usually a nonmetal.

An ionic bond is considered a bond where the ionic character is greater than the covalent character (ionic bonds cannot exist on their own, they must have a covalent bond present also).

Related: Protein Synthesis: 1971 VideoCooking with Chemistry: Hard CandyThe Chemistry of Hair Coloring

Photosynthesis: Science Explained

Another very good webcast on a science topic from Crash Course. It is packed with info, thankfully you can pause and rewind as much as you need. Well normally you can, YouTube decided to not let me do that just now 🙁

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10 Year Old’s Molecule Design Becomes the Topic of a Scientific Paper

10-Year-Old Helps Professor With Theoretical Chemistry by Marimar White-Espin

[10-year-old Clara] Lazen’s teacher, Kenneth Boehr, introduced Border Star Montessori School’s 5th grade class to the periodic table, molecules and chemical bonds. Lazen found the topic interesting and Boehr gave her the tools she needed to explore the subject.

Equipped with a molecule-building kit, Lazen experimented with the colored wooden balls by creating existing molecules and some of her own.

Lazen approached Boehr and asked if the molecule she created using the kit was real. Unsure of the answer, Boehr emailed his longtime graduate school friend and chemistry professor at HSU, Robert Zoellner.

“Maybe [the molecule] is real and we’ll find out,” Zoellner responded.

Upon further research, Zoellner discovered the particular molecule, tetrakis(nitratoxycarbon) methane, Lazen had created had never been discussed in literature and possibly had never been thought of before.

The significance of the molecule Lazen created is that it has the potential to store energy. The dense structure allows for stable energy storage meaning the molecule can be used to produce energy or as an explosive.

Lazen was excited to hear her discovery could be used as an explosive. “I thought, ‘Wow, it could go boom!’ I could put [the molecule] in a bomb and it could blow up something,” she said.

Lazen’s mother, Lori Schmidt was excited to hear that not only would her daughter be a co-author to the scientific article, but the discovery would be recognized in a scientific journal. “One only dreams as a parent,”

Fun stuff.

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The Beneficial Phytochemicals in Vegetables Help Us Lead Healthy Lives

If I don’t pay attention, I won’t eat enough vegetables. Even when I do pay attention I still don’t eat enough (but get closer). Paying attention to what you eat is important for your health.

Some tips from the video.

  • Eat a wide variety of vegetables, to get the benefits each offers.
  • Cruciferous vegetables have cancer preventing benefits and enhancing the immune system. Vegetables in this category include broccoli and cauliflower.
  • Berries also have chemicals that aid in the prevention of cancer.

Related: Healthy Diet, Healthy Living, Healthy WeightEat food. Not too much. Mostly plants.Are Our Vegtables Less Nutritious?

How Lysozyme Protein in Our Tear-Drops Kill Bacteria

A disease-fighting protein in our teardrops has been tethered to a tiny transistor, enabling UC Irvine scientists to discover exactly how it destroys dangerous bacteria. The research could prove critical to long-term work aimed at diagnosing cancers and other illnesses in their very early stages.

Ever since Nobel laureate Alexander Fleming found that human tears contain antiseptic proteins called lysozymes about a century ago, scientists have tried to solve the mystery of how they could relentlessly wipe out far larger bacteria. It turns out that lysozymes have jaws that latch on and chomp through rows of cell walls like someone hungrily devouring an ear of corn.

“Those jaws chew apart the walls of the bacteria that are trying to get into your eyes and infect them,” said molecular biologist and chemistry professor Gregory Weiss, who co-led the project with associate professor of physics & astronomy Philip Collins.

The researchers decoded the protein’s behavior by building one of the world’s smallest transistors – 25 times smaller than similar circuitry in laptop computers or smartphones. Individual lysozymes were glued to the live wire, and their eating activities were monitored.

“Our circuits are molecule-sized microphones,” Collins said. “It’s just like a stethoscope listening to your heart, except we’re listening to a single molecule of protein.”

It took years for the UCI scientists to assemble the transistor and attach single-molecule teardrop proteins. The scientists hope the same novel technology can be used to detect cancerous molecules. It could take a decade to figure out but would be well worth it, said Weiss, who lost his father to lung cancer.

“If we can detect single molecules associated with cancer, then that means we’d be able to detect it very, very early,” Weiss said. “That would be very exciting, because we know that if we treat cancer early, it will be much more successful, patients will be cured much faster, and costs will be much less.”

The project was sponsored by the National Cancer Institute and the National Science Foundation. Co-authors of the Science paper are Yongki Choi, Issa Moody, Patrick Sims, Steven Hunt, Brad Corso and Israel Perez.

Related: full press releaseWhy ‘Licking Your Wounds’ WorksHow Bleach Kills BacteriaAlgorithmic Self-Assembly

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