So I’m sure that all those of us who have already made it back to the states took a plane home, and at some point while the plane was taxiing to and from the runway, or you were waiting for the slow people in front you to get their carry-on luggage and get off the plane, you looked out the window and saw some large fuel trucks. Now we all know that the fuel in there isn’t the same petrol that you put in your car, but what’s the difference?
When fuel for aviation was first deviating from gasoline used in automobiles, it was simply a matter of having a higher octane rating for the more powerful, high-performance engines used in planes. A higher octane rating means that the fuel can be compressed more before combustion, so it can be used in better engines. After the higher octane ratings were achieved, aviators wanted a safer fuel with a higher flash point. The flash point is the temperature at which something can catch fire when exposed to an open flame. Gasoline is a mixture of hydrocarbons ranging from 4 to12 carbons per molecule, and it has a flash point of about 30 degrees Fahrenheit. Jet-A, the kerosene-based commercial jet fuel, was developed which contains hydrocarbons which have anywhere from 5-15 carbons. This fuel has a flash point of 100 degrees Fahrenheit. This fuel can take the compression in jet engines, and is less likely to catch on fire. So the main lesson to take away from this is if you’re ever fueling up a plane, don’t use gasoline.
http://en.wikipedia.org/wiki/Jet_fuel
http://en.wikipedia.org/wiki/Gasoline
http://wiki.answers.com/Q/What_is_the_difference_between_jet_fuel_and_car_fuel
Thursday, July 9, 2009
Wednesday, July 8, 2009
Mosquitoes, Shmosquitoes..
As our final days in Italy come to a close, Sanet and I are enjoying a three-night stay in Venice. With the colorful people and the bustling atmosphere as hundreds and thousands of tourists roam the almost-flooded streets during high tide, we escaped the main island today for a tour of the four islands around the edge of Venice: Murano, Burano, Cimetero, and Torcello. Murano is known for its fabulous Venetian glass, Burano for its handmade lace, Cimetero for its centuries of graves of deceased Venetians, and Torcello for its miniscule population (20) and its leaning church bell tower, which leans at the same degree as Pisa’s famous torre. Way back when, Torcello was actually the birthplace of Venice. People from the mainland would settle here to avoid barbarian masses roaming the lands. But even today, you can see why not many could survive on this island- there is no fresh water, the land can't be farmed, and there is a significant number of mosquitoes. When I read this in Rick Steve’s, I had to curse these “bastard butterflies,” as our Italian friends from Siena liked to call them. Over the past two days, I have been eaten alive by mosquitoes, so I decided to look into some chemistry of how to repel these nasty buggers.
There are many products on the market that claim to repel mosquitoes, both natural and synthetic. The most common natural repellent is citronella oil, which is made from a grass that grows in Southeast Asia. The leaves are picked and dried, then steam-distilled to extract the essential oil, which is added to lotions, candles, etc. Citronellal is the main terpenoid in the oil which gives it the lemon scent it is known for.
Sadly for us, citronella is not actually a very successful repellent, proven by a study published in the Journal of American Mosquito Control Association. Citronella candles and incense reduced the biting rate by less than 50%. A second study published in the same journal found that citronella was the least effective out of three types of essential-oil candles (geraniol candles reduced biting rate by 85%).
Another repellent option which has been controversial for half a century is DEET (N,N-diethyl-3-methylbenzamide).
There are two possible reasons for why DEET repels mosquitoes so well. First, DEET inhibits the carbon dioxide receptors in the bugs' nervous systems, thus rendering them senseless when it comes to smell. Or, instead of jamming their senses of smell, perhaps mosquitoes just don't like the smell of DEET and would prefer to avoid it. Apparently there is a lot more research to be done on this topic. The bad news is that in larger concentrations and with longer exposure times, DEET can be toxic and lead to severe neurological problems.....
So what can I do to keep from becoming completely covered in mosquito bites? Not much since I have no idea how to ask for repellent in Italian. But it's not a big deal since we leave for Atlanta on Saturday morning, to my dismay... At least I will find solace in the fact that I have some awesome anti-itch cream waiting for me in my apartment.
Arrivederci, Italia, you will be missed.
Evaluation of the efficacy of 3% citronella candles and 5% citronella incense for protection against field populations of Aedes mosquitoes. (http://www.ncbi.nlm.nih.gov/pubmed/8827606)
http://expertvoices.nsdl.org/connectingnews/2008/08/26/after-50-years-scientists-still-not-sure-how-deet-works/
There are many products on the market that claim to repel mosquitoes, both natural and synthetic. The most common natural repellent is citronella oil, which is made from a grass that grows in Southeast Asia. The leaves are picked and dried, then steam-distilled to extract the essential oil, which is added to lotions, candles, etc. Citronellal is the main terpenoid in the oil which gives it the lemon scent it is known for.
Sadly for us, citronella is not actually a very successful repellent, proven by a study published in the Journal of American Mosquito Control Association. Citronella candles and incense reduced the biting rate by less than 50%. A second study published in the same journal found that citronella was the least effective out of three types of essential-oil candles (geraniol candles reduced biting rate by 85%).Another repellent option which has been controversial for half a century is DEET (N,N-diethyl-3-methylbenzamide).
There are two possible reasons for why DEET repels mosquitoes so well. First, DEET inhibits the carbon dioxide receptors in the bugs' nervous systems, thus rendering them senseless when it comes to smell. Or, instead of jamming their senses of smell, perhaps mosquitoes just don't like the smell of DEET and would prefer to avoid it. Apparently there is a lot more research to be done on this topic. The bad news is that in larger concentrations and with longer exposure times, DEET can be toxic and lead to severe neurological problems.....So what can I do to keep from becoming completely covered in mosquito bites? Not much since I have no idea how to ask for repellent in Italian. But it's not a big deal since we leave for Atlanta on Saturday morning, to my dismay... At least I will find solace in the fact that I have some awesome anti-itch cream waiting for me in my apartment.
Arrivederci, Italia, you will be missed.
Pharmacokinetics, formulation, and safety of insect repellent N,N-diethyl-3-methylbenzamide (deet): a review. ( http://www.ncbi.nlm.nih.gov/pubmed/8827606)
Evaluation of the efficacy of 3% citronella candles and 5% citronella incense for protection against field populations of Aedes mosquitoes. (http://www.ncbi.nlm.nih.gov/pubmed/8827606)
Indoor Protection Against Mosquito and Sand Fly Bites: A Comparison Between Citronella, Linalool, and Geraniol Candles (http://www.bioone.org/doi/abs/10.2987/8756-971X(2008)24%5B150%3AIPAMAS%5D2.0.CO%3B2)
http://en.wikipedia.org/wiki/Citronella_oil#Use_as_an_insect_repellenthttp://expertvoices.nsdl.org/connectingnews/2008/08/26/after-50-years-scientists-still-not-sure-how-deet-works/
Fire-the-works-up
Yet again I missed out on an opportunity for fireworks and celebration. I didn’t even have some kind of sexy drink with my all-time favorite Perspectives in Chemistry teacher, Dr. Daphne Norton. This 4th of July was a sad reminder that I have only seen fireworks on that day twice in my life. Growing up in another country and then for the last 8 years that I have lived in America, not being in the U.S. for the big day, I have missed out on a great many of these colorful night-time displays. As a tribute to my failed attempt at being patriotic this year, I will instead approach the subject of fireworks from another entertaining point; CHEMISTRY.
Every High School student spent at least one day in a chemistry class in which you could throw some different metals into a flame and watch the pretty colors. If not, then those left surely have at some point in their lives thrown some table salt into a flame and watched the effects as it burned. Throughout time the basic theory behind the chemistry has been used in many versatile ways: art, gun powder, photography, elementary science fair projects, and pyrotechnics. But what is actually happening?
Much thought goes into creating fireworks. Not only do you get different patterns in the sky and different colors, but you also get different kinds of light emitted. The colors of the fireworks come from metal compounds such as strontium (red), aluminum (white), magnesium (white), and copper (blue) among others. These can burn as either incandescent or luminescent light. The first uses light produced from heat, the second uses an energy source other than heat and thus can sometimes be called “cold light”. Incandescent fireworks give many of the orange, yellow, and white colors as increasing temperatures with different compounds. Luminescence comes from the absorption of light by an electron that becomes excited and unstable, when the electron jumps back to its stable, ground state it emits light. This principle can be used in different analytical chemistry techniques such as atomic absorption [spectra] (AAS).
The different chemical components of fireworks are as follows: an oxidizing agent, a reducing agent, a coloring agent, and binders and regulators. Because the nature of fireworks is a combustion reaction an important part of this reaction is oxygen to burn the mixtures. This is provided by the oxidizing agent, commonly nitrates, chlorates or perchlorates. Next, reducing agents burn the oxygen to create hot gasses. A combination of reducing agents can be used to speed or slow the process. Two such reducing agents are Sulfur and charcoal. The coloring agents are as mentioned, different compounds such as, strontium salts and lithium salts for red colors, aluminum, titanium, or magnesium for silver or white, and sodium compounds for yellow colors. The last two elements of fireworks are not very chemical, but rather there for the physical aspect of packaging and the resulting shapes of the fireworks.
I hope this gave some insight into the colorful and creative side of chemistry and the festivities created by its many uses.
Works Cited:
http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=bombs-bursting-in-air-whats-in-thos-2009-07-03
http://chemistry.about.com/od/fireworkspyrotechnics/Fireworks_Pyrotechnics.htm
http://library.thinkquest.org/15384/chem/index.htm
http://chemistry.about.com/od/fireworkspyrotechnics/a/fireworkcolors.htm
Every High School student spent at least one day in a chemistry class in which you could throw some different metals into a flame and watch the pretty colors. If not, then those left surely have at some point in their lives thrown some table salt into a flame and watched the effects as it burned. Throughout time the basic theory behind the chemistry has been used in many versatile ways: art, gun powder, photography, elementary science fair projects, and pyrotechnics. But what is actually happening?
Much thought goes into creating fireworks. Not only do you get different patterns in the sky and different colors, but you also get different kinds of light emitted. The colors of the fireworks come from metal compounds such as strontium (red), aluminum (white), magnesium (white), and copper (blue) among others. These can burn as either incandescent or luminescent light. The first uses light produced from heat, the second uses an energy source other than heat and thus can sometimes be called “cold light”. Incandescent fireworks give many of the orange, yellow, and white colors as increasing temperatures with different compounds. Luminescence comes from the absorption of light by an electron that becomes excited and unstable, when the electron jumps back to its stable, ground state it emits light. This principle can be used in different analytical chemistry techniques such as atomic absorption [spectra] (AAS).
The different chemical components of fireworks are as follows: an oxidizing agent, a reducing agent, a coloring agent, and binders and regulators. Because the nature of fireworks is a combustion reaction an important part of this reaction is oxygen to burn the mixtures. This is provided by the oxidizing agent, commonly nitrates, chlorates or perchlorates. Next, reducing agents burn the oxygen to create hot gasses. A combination of reducing agents can be used to speed or slow the process. Two such reducing agents are Sulfur and charcoal. The coloring agents are as mentioned, different compounds such as, strontium salts and lithium salts for red colors, aluminum, titanium, or magnesium for silver or white, and sodium compounds for yellow colors. The last two elements of fireworks are not very chemical, but rather there for the physical aspect of packaging and the resulting shapes of the fireworks.
I hope this gave some insight into the colorful and creative side of chemistry and the festivities created by its many uses.
Works Cited:
http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=bombs-bursting-in-air-whats-in-thos-2009-07-03
http://chemistry.about.com/od/fireworkspyrotechnics/Fireworks_Pyrotechnics.htm
http://library.thinkquest.org/15384/chem/index.htm
http://chemistry.about.com/od/fireworkspyrotechnics/a/fireworkcolors.htm
The world through rose colored glass
After the studies in Siena ended, I took the opportunity at hand and decided to visit some other places in Italy. It was on this trip that I ended up in Venice… along with the many bridges and canals, taxi boats and gondolas, there was also the wonderful variety of industry native to Venice, such as lace and glass. Not being much taken with the idea of visiting a lace factory, however exciting that may sound, I took a trip to Murano, the small island known for its beautiful creations in the glass blowing factory. I had previously visited a crystal blowing factory with the other Emory students, but Murano was a new experience for me…. Quite a few purchases into my trip, I realize just how lucrative the industry is and some further inspection told me that much of its appeal lies not just in the glass, but the use of color and gold leaf in the actual glass. From this comes my inspiration to for this blog entry: glass and color.
Just as the art of glass blowing had to develop with knowledge and skill, so too did the use of color in glass evolve over time. Colored glass was an accidental discovery, an inventive fluke deriving from impurities. Dark brown or green glass came from impurities in the sand, such as iron, or from the fire smoke, such as sulfur. This fluke lead to the resourceful use of different minerals or metal salts for coloring. Gold chloride creates ruby glass and to make a glow in the dark glass you would use uranium oxide.
Metals can be used in other ways to color glass. Adding metallic compounds to the glass can cause an iridescent effect. Or if you would like that beautiful gold or silver leaf look to the glass without worrying about the metal oxidizing or wearing away, thin layers of colloidal metals are added to the glass and then coating that with another layer of clear glass.
Most of the colored glasses involve some sort of metal oxide ‘contaminating’ the glass itself, such as iron oxide (green, brown), cobalt oxide (deep blue), manganese oxide (deep amber, amethyst), and antimony oxides (white). A lot of the finer designs, though, have other secrets that have nothing to do with combination chemistry of glass and other compounds, but instead is simply the use of glass layering a beautiful work of brushstroke or similar technique.
So next time you pick up that gorgeous green glass that your friend brought you back from Murano, ask yourself: “Is there any iron in this?”
Cited works:
http://www.sciencedaily.com/releases/2009/06/090617123435.htm
http://chemistry.about.com/cs/inorganic/a/aa032503a.htm
Just as the art of glass blowing had to develop with knowledge and skill, so too did the use of color in glass evolve over time. Colored glass was an accidental discovery, an inventive fluke deriving from impurities. Dark brown or green glass came from impurities in the sand, such as iron, or from the fire smoke, such as sulfur. This fluke lead to the resourceful use of different minerals or metal salts for coloring. Gold chloride creates ruby glass and to make a glow in the dark glass you would use uranium oxide.
Metals can be used in other ways to color glass. Adding metallic compounds to the glass can cause an iridescent effect. Or if you would like that beautiful gold or silver leaf look to the glass without worrying about the metal oxidizing or wearing away, thin layers of colloidal metals are added to the glass and then coating that with another layer of clear glass.
Most of the colored glasses involve some sort of metal oxide ‘contaminating’ the glass itself, such as iron oxide (green, brown), cobalt oxide (deep blue), manganese oxide (deep amber, amethyst), and antimony oxides (white). A lot of the finer designs, though, have other secrets that have nothing to do with combination chemistry of glass and other compounds, but instead is simply the use of glass layering a beautiful work of brushstroke or similar technique.
So next time you pick up that gorgeous green glass that your friend brought you back from Murano, ask yourself: “Is there any iron in this?”
Cited works:
http://www.sciencedaily.com/releases/2009/06/090617123435.htm
http://chemistry.about.com/cs/inorganic/a/aa032503a.htm
More Good News Involving Wine
So we’ve learned all about the antioxidant capabilities of the polyphenols in wine, but what about the other health benefits of some of these compounds? One in particular, resveratrol, has been linked to many health benefits including life extension, cancer prevention, and even lowering blood-sugar levels. Resveratrol is produced naturally by plants that are being attacked by things like bacteria or fungi, but they are also found in the skins of red grapes and are therefore present in red wine.
Human testing has been limited with this compound, but it has been shown that it can extend the median life of flies, worms, and even fish by a significant amount. Animal studies have also shown that it is effective against cancer as long as it can be delivered to the necessary areas in significant amounts. The only time that a study using humans has had positive results with resveratrol was in a study that showed how high doses of it significantly lowered blood sugar levels.
The exact mechanisms of resveratrol are not well understood, but it has been shown to activate different enzymes, and in some cases, cause apoptosis (programmed cell death) which could explain some of their anti cancer properties. Although resveratrol may not end up making us live longer, cancer free lives, it does give us another reason to keep drinking red wine.
References:
http://en.wikipedia.org/wiki/Resveratrol
Human testing has been limited with this compound, but it has been shown that it can extend the median life of flies, worms, and even fish by a significant amount. Animal studies have also shown that it is effective against cancer as long as it can be delivered to the necessary areas in significant amounts. The only time that a study using humans has had positive results with resveratrol was in a study that showed how high doses of it significantly lowered blood sugar levels.
The exact mechanisms of resveratrol are not well understood, but it has been shown to activate different enzymes, and in some cases, cause apoptosis (programmed cell death) which could explain some of their anti cancer properties. Although resveratrol may not end up making us live longer, cancer free lives, it does give us another reason to keep drinking red wine.
References:
http://en.wikipedia.org/wiki/Resveratrol
Boron cancer threrapy part 2
I wanted to talk more about the Boron therapy for cancer that Dr Soria talked about in his class. The ideal therapy is the one in which only the cancerous cells are destroyed without damaging healthy tissue or affecting the function of important systems specially when treating brain tumors because the cells of the brain are the most sensitive and the ones with the most important function. BNCT is a technique that uses radiation to destroy the cells but the way it works is different and is much more selective because it destroys only the cells close to the target cell.
This is not the typical radiation technique since the beam does not destroy all of the tumor cells but the target cell is one which contains an isotope of boron. The key in this process is that the boron attaches to the cancer cell by attaching it to compunds that have special affinity for tumor cells.
The basic principle for the neutron capture therapy. A higher concentration of Boron exists in the tumor cells than in the nomrmal ones. Nuclides have different affinity for the thermal neutrons absoption. Of the nucleides that have this affinity B-10 is the most attractive because it is not radioactive and is very avaliable. Even if the affinity of most of the tissues is the highest for boron there are considerably amounts of nitrogen and hydrogen and its content inside the cell are significant. To avoid the presence of these undesirable isotopes the high amounts of Boron 10 are attached to the cell until the point that is saturates the cell.
This is not the typical radiation technique since the beam does not destroy all of the tumor cells but the target cell is one which contains an isotope of boron. The key in this process is that the boron attaches to the cancer cell by attaching it to compunds that have special affinity for tumor cells.
The basic principle for the neutron capture therapy. A higher concentration of Boron exists in the tumor cells than in the nomrmal ones. Nuclides have different affinity for the thermal neutrons absoption. Of the nucleides that have this affinity B-10 is the most attractive because it is not radioactive and is very avaliable. Even if the affinity of most of the tissues is the highest for boron there are considerably amounts of nitrogen and hydrogen and its content inside the cell are significant. To avoid the presence of these undesirable isotopes the high amounts of Boron 10 are attached to the cell until the point that is saturates the cell.
Ode to Jet Lag
Monday morning in Rome, Anne and I woke up at 6:30am to catch the train from Termini station to the airport. We arrived at the airport a little before 9 and my flight was scheduled to leave at 11:20. I boarded the plane around 10:30 and the plane did not take off until around 3:45pm, due to some “technical difficulties.” I landed in Washington D.C. at 7:30pm (1:30am Italy time) and waited until 10pm for my connecting flight. I finally arrived in Rochester at midnight, and arrived at my house at 12:30am (6:30am Italy time), exactly 24 hours after I had woken up in Rome. Within that 24 hour period I took 3 naps; each lasted no more than an hour. I did not actually go to sleep until almost 2am, and somehow I woke up at 4:30am. My body was completely still on Italy time, so waking up at 10:30am Italy time was apparently enough of a sleep in, despite my lack of sleep over the previous 28 hours. This got me thinking – why do I need sleep in the first place? What exactly is sleep and why couldn’t I manage to fall back asleep even though I was so tired?
The reasons for sleep are still not well understood, though sleep is always being studied. What is definite about sleep is that it gives the body time to recharge its batteries by repairing muscles and replacing dead cells. Sleep also gives the brain time to organize memories – it is believed that dreams play a role in this. A lack of sleep compromises the immune system and the ability to think clearly. Certain chemicals released in the brain are associated with sleep. Growth hormone is released in children while they sleep, and the levels of the neurohormone orexin vary greatly from sleeping to wakened periods. The level of melatonin in the body is also raised during the sleeping period.
A study done on cats showed that the levels of adenosine are directly related to sleep. Adenosine is the nucleoside that forms the core of adenosine triphosphate (ATP), the molecule that powers most of the biochemical reactions inside cells. According to the study, adenosine levels build up during waking hours and decline during sleep periods. This research suggests that the body’s regular need for sleep comes from the brain’s need to replenish low stores of energy. When an animal’s energy levels in the brain get low, levels may be restored through sleep. Rising concentrations of adenosine may be how the brain recognizes that it is running low on energy and needs to recharge. When researchers deprived cats of sleep for 6 hours, their adenosine levels were double what they had been after being awake for 2 hours. When they were finally allowed to sleep for 3 hours, the adenosine levels slowly declined. This must be why I woke up at 4:30am yesterday, despite my sleep deprivation over the previous day. My guess is that my short naps were long enough to lower adenosine levels in my brain to the point where my body’s normal sleep schedule was more important to my sleep patterns than my utter exhaustion. Oh well, luckily I have plenty of time to catch up on sleep in the next few days.
Like many of the other students did, I also would like to thank everyone for a phenomenal 5 weeks. All the amazing activities and great friendships I made definitely place this summer in my top 5. For anyone who doesn’t realize, that means this summer is rivaling with summers spent at *gasp* Jew camp! Now you all know I’m serious when I say grazie mille for making this summer unforgettable. You all rock :)
References:
http://health.howstuffworks.com/sleep.htm
http://www.sciencenews.org/sn_arc97/5_24_97/fob2.htm
http://www.chemistrydaily.com/chemistry/Sleep
The reasons for sleep are still not well understood, though sleep is always being studied. What is definite about sleep is that it gives the body time to recharge its batteries by repairing muscles and replacing dead cells. Sleep also gives the brain time to organize memories – it is believed that dreams play a role in this. A lack of sleep compromises the immune system and the ability to think clearly. Certain chemicals released in the brain are associated with sleep. Growth hormone is released in children while they sleep, and the levels of the neurohormone orexin vary greatly from sleeping to wakened periods. The level of melatonin in the body is also raised during the sleeping period.
A study done on cats showed that the levels of adenosine are directly related to sleep. Adenosine is the nucleoside that forms the core of adenosine triphosphate (ATP), the molecule that powers most of the biochemical reactions inside cells. According to the study, adenosine levels build up during waking hours and decline during sleep periods. This research suggests that the body’s regular need for sleep comes from the brain’s need to replenish low stores of energy. When an animal’s energy levels in the brain get low, levels may be restored through sleep. Rising concentrations of adenosine may be how the brain recognizes that it is running low on energy and needs to recharge. When researchers deprived cats of sleep for 6 hours, their adenosine levels were double what they had been after being awake for 2 hours. When they were finally allowed to sleep for 3 hours, the adenosine levels slowly declined. This must be why I woke up at 4:30am yesterday, despite my sleep deprivation over the previous day. My guess is that my short naps were long enough to lower adenosine levels in my brain to the point where my body’s normal sleep schedule was more important to my sleep patterns than my utter exhaustion. Oh well, luckily I have plenty of time to catch up on sleep in the next few days.
Like many of the other students did, I also would like to thank everyone for a phenomenal 5 weeks. All the amazing activities and great friendships I made definitely place this summer in my top 5. For anyone who doesn’t realize, that means this summer is rivaling with summers spent at *gasp* Jew camp! Now you all know I’m serious when I say grazie mille for making this summer unforgettable. You all rock :)
References:
http://health.howstuffworks.com/sleep.htm
http://www.sciencenews.org/sn_arc97/5_24_97/fob2.htm
http://www.chemistrydaily.com/chemistry/Sleep
Tuesday, July 7, 2009
A Future With Swirl-Shaped Cell Membranes!
Last Wednesday, I gave a presentation on the chemical properties for the formation of patterns in nature. One of my examples involved fairly current research on the pattern formation of the lipid bilayer. I found this study truly exciting and will explain it in more detail. The Belousov-Zhabotinsky reaction (BZ reaction) involves the addition of energy to a medium containing bromine and an acid. The addition of “fuel” breaks the second law of thermodynamics and leads to the accumulation of undesirable products. Once the necessary reagents run out, the reaction reverses and regains equilibrium.
Current research on the lipid bilayer involves the addition of the BZ reaction to the lipid bilayer to alter the sandwich model. The sandwich model represents a phosholipid layer between two outer protein layers. Before the BZ reaction was analyzed for pattern formation, the integrity of the bilayer was detected through x-ray scattering. X-ray scattering reveals a sample’s shape and size through the sample’s dispersion of x-rays. The x-ray scattering results revealed that the integrity of the lipid bilayer was maintained by the addition of BZ reagents.
The next step of the experiment involved the addition of BZ reagents to observe he various pattern formations of the lipid bilayer. Each pattern was classified depending on the lipid content. The lipid content is represented by the percentage of the weight of the lipid over the total weight of the solution. The mechanism behind the BZ reaction with the lipid bilayer is not known yet. One theory involves the presence of pore-like defects in the lipid bilayer that may allow the disruption of the sandwich model for new patterns. Researchers plan to use this information as a model for patterning phenomena in nature.
Reference
Rossi, F.; Ristori, S.; Rustici, M.; Marchettini, N.; Tiezzi, E. Dynamics of pattern formation in biomimetic systems Journal of Theoretical Biology 2008, 255, 404-412.
Current research on the lipid bilayer involves the addition of the BZ reaction to the lipid bilayer to alter the sandwich model. The sandwich model represents a phosholipid layer between two outer protein layers. Before the BZ reaction was analyzed for pattern formation, the integrity of the bilayer was detected through x-ray scattering. X-ray scattering reveals a sample’s shape and size through the sample’s dispersion of x-rays. The x-ray scattering results revealed that the integrity of the lipid bilayer was maintained by the addition of BZ reagents.
The next step of the experiment involved the addition of BZ reagents to observe he various pattern formations of the lipid bilayer. Each pattern was classified depending on the lipid content. The lipid content is represented by the percentage of the weight of the lipid over the total weight of the solution. The mechanism behind the BZ reaction with the lipid bilayer is not known yet. One theory involves the presence of pore-like defects in the lipid bilayer that may allow the disruption of the sandwich model for new patterns. Researchers plan to use this information as a model for patterning phenomena in nature.
Reference
Rossi, F.; Ristori, S.; Rustici, M.; Marchettini, N.; Tiezzi, E. Dynamics of pattern formation in biomimetic systems Journal of Theoretical Biology 2008, 255, 404-412.
Blingin' Security Checks please?
For Dr. Soria’s presentations, I researched a lot of information on gold nanoparticle use for cancer treatment. I planned on blogging about other applications for gold nanoparticles and was intrigued by its use in toxin detection. These nanoparticles make possible a portable detection system that could scan for viruses, bacteria, and toxins used by bio-terrorists, perhaps right in the airport. However, my own personal airport TSA search coming back from Italy was not so pleasant as to include gold nanoparticles.
Nanoparticles can be conjugated to antibodies specific for the toxin in question. These probes can then be used with a very small sample of cells. Once bound, a comparison of infected cells and healthy cells should yield a dramatic difference in appearance. The difference between gold nanoparticle detection and previous methods is its portability and rapid speed. Once the nanoparticles are bound, visualization through a microscope shows cells covered with the light-reflecting probes.
A more quantitative method sometimes used is surface plasmon resonance spectroscopy, which measures the nanoparticles’ interaction with light at specific frequencies. Higher or lower absorbances mark higher or lower amounts of bound probes. Specifically for ease in toxin detection, new research has taken advantage of visible color changes. Nanoparticles are created and then coated with sugars. This weak solution is then mixed with the toxin, modified, and yields a solution with a new color. A pure gold nanoparticle solution is made at first to be red but changes blue when a toxin is present. The depth of color correlates to the concentration of toxin as well. Further research on this topic could yield almost endless possibilities. Forensic chemistry could use gold nanoparticles at crime scenes, and water sources could be determined whether safe or unsafe to drink.
References:
http://news.bbc.co.uk/2/hi/technology/4872188.stm
Sunday, July 5, 2009
Issues with Radiocarbon Dating
As I was flying home this weekend, I was thinking of what I could write my final blog about and I came up across the concept of radiocarbon dating in the book I was reading, Guns, Germs, and Steel. (I also came across The Shroud of Turin when I was watching the Pink Panther 2, but I didn’t think I could write a meaningful blog about such a ridiculous movie). I know that Imran had talked about radiocarbon dating in a previous blog, but I just wanted to talk about some of the problems of radiocarbon dating that were mentioned in this book.
During photosynthesis, plants intake atmospheric carbon. The ratio of carbon-14 to carbon-12, two isotopes of carbon, in atmospheric carbon is approximately 1:1,000,000. However, once a plant dies, approximately half of the carbon-14 decays into carbon-12 every 5700 years. Therefore, the date of a specific plant is based on the ratio of carbon-14 to carbon-12.
Until the 1980’s, scientists had a problem dating small materials found in archeological sites because a substantial amount of carbon needed to be collected from the source in order to determine its age. However, this problem was solved with a technique called accelerator mass spectrometry. This technique only required a very small sample and thus was vital in many historical discoveries. One example is that concept of food production. It was originally thought to originate in the
However, another scientific discovery was that the ratio of carbon-14 to carbon-12 in the atmosphere is not always constant. This ratio changes with time. Therefore, some radiocarbon dates needed to be ‘calibrated’ with a new ratio. This was done with the help of growth rings in long-lived trees. The trees had a known specific date (based on the very accurate growth rings), and then the carbon ratio was analyzed in these trees to determine what the true ratio of carbon-14 to carbon-12 was during that age. This discovery had a strong influence on some archeological sites which were incorrectly dated based on the old ratio. Even now, other sites are still being accessed and calibrated so that the true dates of the sites can be known.
Like others, I just wanted to end this blog with a word of thanks and gratitude toward my peers and professors. I have never had an experience like these past five weeks and I will never forget it. I truly hope to see each and every one of you in the near future. Until then, Arrivederci!
Eating like a Horse
As our trip to Siena comes to a close, Arthur, Ankush, and I decided to partake in a final ritual of manhood: eating. Now we are no Joey Chestnut or Takeru Kobayashi, two men who just ate 60+ hot dogs at the Nathan's Hot Dog Eating Contest. We are not even Daniel Oyon, Santoh Reddy, or Yoav Karpenshif, who took down the powerful Matthew Weinschenk by eating a dozen Krispy Kremes. No, we were much gutsier. We three geniuses of gastronomia ate a one kilogram steak each. If you are trying to do the calculation in your head, 1 kilo is about 2.2 pounds and 2.2 pounds is about 35 ounces of pure meaty goodness. As Arthur and I said, that steak was “the best worst decision of our lives,” as are still digesting it. While we tried to cut through the three inches of mammal, with gallons of sweat streaming down our faces, I naturally thought about chemistry and how my stomach would break down eating the equivalent of a puppy. I was really thinking about it 24 hours later when I felt like a cow had overtaken my body. Thus, I would like to talk about the fine art of digesting protein, as we had enough protein for a family of five. (Just for your information, in 100 grams of a t-bone steak there is approximately 24 grams of protein. That means we ate about 240 grams. The recommended daily allowance of protein is about 50 grams. Eat your heart out Arnold Schwarzenegger.)
Digesting protein is really quite simple. Protein is made up of long amino acid chains that we know helps aid in muscle formation. The environment in the stomach is mostly made of pepsin, hydrochloric acid with a pH from 2-5. This acid is secreted by parietal cells at a pH of about 0.8, but after mixing with other stomach liquids it reaches a pH from 2-3. The long chains of protein are broken down into smaller chains by these strong acids as the food passes into your small intestine. Then, enzymes from the pancreas (such as trypsin and chymotrypsin) break down the proteins further. Now, the small amino chains are absorbed into the body.
Many enzymes are required in this process because each amino acid chain breaks down differently. If food is broken down appropriately and not eaten to excess (*cough* Arthur, Ankush and I) almost 100% of protein is made into individual amino acids.
I would like to end this last blog post, much like Imran, by thanking everyone involved in this trip. From the Unisi students and faculty, to Natalie, to our tremendous professors in Dr. Soria and Dr. Norton, to eighteen incredible kids, I have never had more fun or enjoyed living so much as on this trip. To the Unisi people, thanks for your warm hospitality, pleasing dinners, and accepting us as your own. To our professors, thank you for putting up with all of our loud mouths while still allowing us to have fun. Oh, and thanks for going to that ridiculous carnival with us. Finally, thanks to eighteen of the most intelligent, entertaining, and legendary kids at Emory University. I am glad to hold the record for the largest party at the Refugio: 10-15 people playing cards in the common room. The stories I have are uncountable and I look forward to telling them for years to come. Siena will never be the same.
p.s. Sameer does not eat pork.
References
http://tuberose.com/Digestion.html
http://www.netrition.com/rdi_page.html
http://www.highproteinfoods.net/beef-and-veal/1576
Digesting protein is really quite simple. Protein is made up of long amino acid chains that we know helps aid in muscle formation. The environment in the stomach is mostly made of pepsin, hydrochloric acid with a pH from 2-5. This acid is secreted by parietal cells at a pH of about 0.8, but after mixing with other stomach liquids it reaches a pH from 2-3. The long chains of protein are broken down into smaller chains by these strong acids as the food passes into your small intestine. Then, enzymes from the pancreas (such as trypsin and chymotrypsin) break down the proteins further. Now, the small amino chains are absorbed into the body.
Many enzymes are required in this process because each amino acid chain breaks down differently. If food is broken down appropriately and not eaten to excess (*cough* Arthur, Ankush and I) almost 100% of protein is made into individual amino acids.
I would like to end this last blog post, much like Imran, by thanking everyone involved in this trip. From the Unisi students and faculty, to Natalie, to our tremendous professors in Dr. Soria and Dr. Norton, to eighteen incredible kids, I have never had more fun or enjoyed living so much as on this trip. To the Unisi people, thanks for your warm hospitality, pleasing dinners, and accepting us as your own. To our professors, thank you for putting up with all of our loud mouths while still allowing us to have fun. Oh, and thanks for going to that ridiculous carnival with us. Finally, thanks to eighteen of the most intelligent, entertaining, and legendary kids at Emory University. I am glad to hold the record for the largest party at the Refugio: 10-15 people playing cards in the common room. The stories I have are uncountable and I look forward to telling them for years to come. Siena will never be the same.
p.s. Sameer does not eat pork.
References
http://tuberose.com/Digestion.html
http://www.netrition.com/rdi_page.html
http://www.highproteinfoods.net/beef-and-veal/1576
Saturday, July 4, 2009
Caught in the Act: Art Forgery
Art forgery has existed for thousands of years dating back to a time when ancient Roman sculptors produced fake copies of Greek sculptures. Yet, perhaps the most famous story of forgery occurred in the Renaissance, 1496 to be exact, and involved the great Michelangelo. At a young age, Michelangelo decided to test his skill by sculpting a sleeping cupid statue, burying it in the acidic earth, and passing it off as an antiquity. The artificially aged statue found its way into the hands of Cardinal Raffaello Riario of San Giorgi. Only after hearing of Michelangelo’s bragging did the Cardinal learn of the forgery and demand his money back. Nowadays, however, there are other ways to learn of a forgery than through counterfeiters’ boasting.
Through a talented team of art conservators and scientists, the authenticity of a painting can be determined in a variety of ways beyond the initial visual analysis. These include: carbon dating, X-ray radiographs, and X-ray diffraction. All of these techniques hinge on verifying the date of the painting by examining the materials that comprise the work of art. Carbon dating, a method that analyzes the ratio of carbon isotopes 12C and 14C, is useful in determining the age of materials less than 10,000 years. X-ray radiographs, on the other hand, help conservators see the creative process of the artist, revealing every layer of paint on the canvas. Sometimes a painting will appear to be an antique until radiographs reveal a typical 19th-century painting underneath. Lastly, X-ray diffraction is used to understand the pigments in the painting. Conservators and art historians alike know the dates of when certain pigments were introduced into the art world. For example, if X-ray diffraction shows the usage of Prussian blue, an ink of the 18th century, in a painting that claims to be of the 17th century, it is a fraud.
Clearly it is important for paintings to be examined before being sold to museums and collectors for large sums. Carbon dating, X-ray radiographs and X-ray diffraction are only a few of the techniques utilized by scientists to verify a painting’s authenticity. And while the number and accuracy of the techniques used by conservators grow, the techniques of modern-day forgers are desperately trying to keep pace and trick us once again.
References:
http://www.history.com/encyclopedia.do?articleId=201568
http://www.museumofhoaxes.com/hoax/Hoaxipedia/Renaissance_Forgeries/
The all powerful oxygen
After much thought, I decided to write my last blog about a topic I thoroughly enjoyed researching for my second paper: atomic oxygen. A single atom of oxygen, atomic oxygen does not exist in Earth's atmosphere. In space, however, it is formed when the sun's UV rays split diatomic oxygen into a pair of free radical oxygen. This atom is destructive on its own because it has two unpaired electrons that are desperate to pair with other electrons.
Researchers at NASA accidentally discovered that atomic oxygen could be used to remove layers of organic material from a surface. This discovery created awareness that atomic oxygen could be used for removing organic contaminants or aged varnishes from the surface of paintings.
Remember how in the linseed oil article from class there was a reference made about how some lady kissed a painting of a tub, planting a big one near the bottom of the painting? The painting, "Bathtub," by Andy Warhol had to be restored using the atomic oxygen method since traditional solvent methods were unable to be utilized.
On a side note, worldwide an average of one collection or gallery suffers fire damage every day (estimated), and paintings damaged by charring are very resistant to traditional cleaning techniques. Current processes used to restore artwork generally use chemical solvents to remove dirt, varnish and thin layers of soot. With damage from heavy deposits of soot, or even charring or graffiti, these techniques are not effective. NASA found that atomic oxygen could remove layers of soot from charred paintings too. How? Because atomic oxygen will not react with inorganic oxides, such as most paint pigments, it could be used to restore paintings damaged by soot.
Below is a link portraying how atomic oxygen was used to restore the charred painting, Madonna of the Chair. The left photograph was taken after the Cleveland Museum of Art staff used acetone and methylene chloride to clean and restore the painting. The right half was taken after Glenn researchers used the atomic oxygen technique to clean the painting.
http://www.nasa.gov/images/content/67935main_atomicox_big.jpg
I just want to end this last post of mine by saying that I enjoyed my entire stay in Italy with 18 of the most interesting characters I have ever met, all of who I have grown to love in just a matter of a few weeks. Oh and Natalie, Daphne, and Jose, you guys aren't half bad either!!! Just playing, of course. Thank you, everyone (including Renzo, Gabriella, Daniela and the Italian students), for making this one of the most pleasant, exciting, and memorable experiences I have ever had! I hope to see everyone around during my final year of college at Emory! I love you guys!
Sources:
http://www.nasa.gov/vision/earth/everydaylife/AtomicOxRestoration.html
Researchers at NASA accidentally discovered that atomic oxygen could be used to remove layers of organic material from a surface. This discovery created awareness that atomic oxygen could be used for removing organic contaminants or aged varnishes from the surface of paintings.
Remember how in the linseed oil article from class there was a reference made about how some lady kissed a painting of a tub, planting a big one near the bottom of the painting? The painting, "Bathtub," by Andy Warhol had to be restored using the atomic oxygen method since traditional solvent methods were unable to be utilized.
On a side note, worldwide an average of one collection or gallery suffers fire damage every day (estimated), and paintings damaged by charring are very resistant to traditional cleaning techniques. Current processes used to restore artwork generally use chemical solvents to remove dirt, varnish and thin layers of soot. With damage from heavy deposits of soot, or even charring or graffiti, these techniques are not effective. NASA found that atomic oxygen could remove layers of soot from charred paintings too. How? Because atomic oxygen will not react with inorganic oxides, such as most paint pigments, it could be used to restore paintings damaged by soot.
Below is a link portraying how atomic oxygen was used to restore the charred painting, Madonna of the Chair. The left photograph was taken after the Cleveland Museum of Art staff used acetone and methylene chloride to clean and restore the painting. The right half was taken after Glenn researchers used the atomic oxygen technique to clean the painting.
http://www.nasa.gov/images/content/67935main_atomicox_big.jpg
I just want to end this last post of mine by saying that I enjoyed my entire stay in Italy with 18 of the most interesting characters I have ever met, all of who I have grown to love in just a matter of a few weeks. Oh and Natalie, Daphne, and Jose, you guys aren't half bad either!!! Just playing, of course. Thank you, everyone (including Renzo, Gabriella, Daniela and the Italian students), for making this one of the most pleasant, exciting, and memorable experiences I have ever had! I hope to see everyone around during my final year of college at Emory! I love you guys!
Sources:
http://www.nasa.gov/vision/earth/everydaylife/AtomicOxRestoration.html
Dude, are you crying?
As our journey here in Siena comes to an end, we say our goodbyes to new friends, wondering if we will ever see them again or come back to this beautiful city. After saying goodbye to some of our closest Italian friends, Angelo and Paolo, I started wondering if there was any chemistry behind the act of crying. Being a guy, of course I have never shed a tear in my life, except in the movie Click, which was an unbelievably sad movie. Though I could find little information about the emotional act of crying, I did come across why onions make people cry, which I also found interesting. After eating an entire onion for fun at one point in my life, I have been somewhat curious about this vegetable.
Everyone knows that cutting up onions will make your eyes burn a bit and tear up. When you cut an onion, you break cells, releasing their contents of amino acid sulfoxides. Enzymes mix with these acids to form propanethiol that float to your eyes. This reacts with the water in your eyes to form sulfuric acid; this irritates your eyes, causing your eyes to release tears to wash it away. Cooking onions inactivates the enzyme, so the smell of cooked onions do not burn your eyes. If your eyes really irritate you when you are trying to chop up onions, you can try refrigerating onions before cutting them, as the cooler temperature will slow down the reaction, or cutting the onion underwater.
Also, I had a great time in Siena with all of you. I wish nothing but the best for everyone’s future. If anyone wants to have a glass of wine with me back in the states, give me a ring and I’ll try my best to come, after all, I do like to party.
http://chemistry.about.com/od/chemistryfaqs/f/onionscry.htm
Everyone knows that cutting up onions will make your eyes burn a bit and tear up. When you cut an onion, you break cells, releasing their contents of amino acid sulfoxides. Enzymes mix with these acids to form propanethiol that float to your eyes. This reacts with the water in your eyes to form sulfuric acid; this irritates your eyes, causing your eyes to release tears to wash it away. Cooking onions inactivates the enzyme, so the smell of cooked onions do not burn your eyes. If your eyes really irritate you when you are trying to chop up onions, you can try refrigerating onions before cutting them, as the cooler temperature will slow down the reaction, or cutting the onion underwater.
Also, I had a great time in Siena with all of you. I wish nothing but the best for everyone’s future. If anyone wants to have a glass of wine with me back in the states, give me a ring and I’ll try my best to come, after all, I do like to party.
http://chemistry.about.com/od/chemistryfaqs/f/onionscry.htm
A chilling injury...
As I was cleaning out our refrigerator this morning in the Refugio, I came across a long lost banana that I had left in there during the Brazil V. US game. Of course, the banana looked completely nasty, but since I had no other food... I ate it. And you know what? It was good. I mean gooood. So, I decided to look into banana peels and why they turn black and unappealing.
In 2007, there was a study done on how heat treatments effect the browning of banana peels, a.k.a. their chilling injury (or CI). Previous studies had shown that if treated in hot water before cold storage, other tropical fruits showed less ripening and browning, so, why not bananas too? The bananas were gathered at 80% maturity, which is the same maturity that we would buy in a grocery store. They were then placed in water at 42 degrees C for 5, 10, or 15 minutes, then stored at 4 degrees C. At various points during cold storage, samples from the peels were taken to observe any chemical or structural changes.
The results? The main reason for chilling injury is the amount of saturated versus unsaturated fatty acids in the peels. The control bananas (which were not treated with the hot water) showed an increase is saturated FAs and a decrease in unsaturated FAs. The heat treatments prevented the increase in saturated FAs while changing the decrease of unsaturated FAs to an increase in them. Basically, the better the ratio of saturated versus unsaturated fatty acids, the higher the peel's tolerance to cold temperatures. The heat treated bananas began browning four days later than those not treated, and after ten days, the heat treated bananas did not show maximum blackening, while the control bananas looked like the banana I found in our fridge.
So the moral of the story: if you want to store your bananas in the refrigerator without them becoming black and gross, you should try the hot water treatment, and let me know how it goes.
And for your entertainment, here is another experiment done with banana peels brought to you by Mythbusters.... http://www.youtube.com/watch?v=YZRq3XxCZXo
And for further reading on the experiment, here is the paper.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TBJ-4R5G84B-3&_user=7597297&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=947741236&_rerunOrigin=google&_acct=C000036918&_version=1&_urlVersion=0&_userid=7597297&md5=a8368c83c4f5118cb1c9be9b16d375fa
In 2007, there was a study done on how heat treatments effect the browning of banana peels, a.k.a. their chilling injury (or CI). Previous studies had shown that if treated in hot water before cold storage, other tropical fruits showed less ripening and browning, so, why not bananas too? The bananas were gathered at 80% maturity, which is the same maturity that we would buy in a grocery store. They were then placed in water at 42 degrees C for 5, 10, or 15 minutes, then stored at 4 degrees C. At various points during cold storage, samples from the peels were taken to observe any chemical or structural changes.
The results? The main reason for chilling injury is the amount of saturated versus unsaturated fatty acids in the peels. The control bananas (which were not treated with the hot water) showed an increase is saturated FAs and a decrease in unsaturated FAs. The heat treatments prevented the increase in saturated FAs while changing the decrease of unsaturated FAs to an increase in them. Basically, the better the ratio of saturated versus unsaturated fatty acids, the higher the peel's tolerance to cold temperatures. The heat treated bananas began browning four days later than those not treated, and after ten days, the heat treated bananas did not show maximum blackening, while the control bananas looked like the banana I found in our fridge.
So the moral of the story: if you want to store your bananas in the refrigerator without them becoming black and gross, you should try the hot water treatment, and let me know how it goes.
And for your entertainment, here is another experiment done with banana peels brought to you by Mythbusters.... http://www.youtube.com/watch?v=YZRq3XxCZXo
And for further reading on the experiment, here is the paper.
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TBJ-4R5G84B-3&_user=7597297&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=947741236&_rerunOrigin=google&_acct=C000036918&_version=1&_urlVersion=0&_userid=7597297&md5=a8368c83c4f5118cb1c9be9b16d375fa
Friday, July 3, 2009
Sore muscles
The weekend before last, several friends and I travelled to Cinque Terre, where we hiked through the trails connecting each of the five coastal towns. By the time we got back to Siena however, my legs were quite stiff and sore, just like the soreness one feels after a long run or a day at the gym. At any rate, within a day or two, my legs were back to normal. Just as I did at one time, some of you may be wondering why your muscles get sore after a tough workout.
Your cells obtain the energy needed to do work (i.e. hiking over a mountain) by breaking down glucose to produce ATP (adenosine triphosphate). This is typically done through an aerobic process in which glucose is broken down to pyruvate, which is then broken down further to carbon dioxide and water through the electron transport chain. This process is aerobic because oxygen is the final electron acceptor at the end of the electron transport chain, where it is converted to water. However, in times when large amounts of energy are required, such as weight lifting or sprinting, the amount of ATP needed is typically far greater than the amount of oxygen the lungs can provide.
When this happens, the body switches to an anaerobic process, in which oxygen is not used. Although this process does not produce nearly as much energy, it does produce enough to allow body functions to continue. As your breathing and heart rate increase, oxygen levels in muscle tissue eventually peak. When this happens, the electron transport chain function also peaks. However, because glucose is being broken down at a much faster rate, pyruvate eventually begins to build up inside the cell. This excess pyruvate is then diverted into an alternative pathway, through which it is converted to lactic acid. It is the presence of this lactic acid that leads to muscle soreness because it cannot be readily eliminated by the cell, unlike carbon dioxide and water.
When the body’s energy requirements subsequently drop, the anaerobic processes eventually stop. However, the muscle cells still require a minimal amount of energy to for normal daily function, and so all the pyruvate produced is once again pushed into the electron transport chain. In addition, all the lactic acid that has built up in the cells begins to be converted back to pyruvate, which then can also be sent to the electron transport chain. Consequently, within a day or two, all the lactic acid that has built up in the cells will have been converted back into pyruvate and all the muscle soreness will be gone.
Your cells obtain the energy needed to do work (i.e. hiking over a mountain) by breaking down glucose to produce ATP (adenosine triphosphate). This is typically done through an aerobic process in which glucose is broken down to pyruvate, which is then broken down further to carbon dioxide and water through the electron transport chain. This process is aerobic because oxygen is the final electron acceptor at the end of the electron transport chain, where it is converted to water. However, in times when large amounts of energy are required, such as weight lifting or sprinting, the amount of ATP needed is typically far greater than the amount of oxygen the lungs can provide.
When this happens, the body switches to an anaerobic process, in which oxygen is not used. Although this process does not produce nearly as much energy, it does produce enough to allow body functions to continue. As your breathing and heart rate increase, oxygen levels in muscle tissue eventually peak. When this happens, the electron transport chain function also peaks. However, because glucose is being broken down at a much faster rate, pyruvate eventually begins to build up inside the cell. This excess pyruvate is then diverted into an alternative pathway, through which it is converted to lactic acid. It is the presence of this lactic acid that leads to muscle soreness because it cannot be readily eliminated by the cell, unlike carbon dioxide and water.
When the body’s energy requirements subsequently drop, the anaerobic processes eventually stop. However, the muscle cells still require a minimal amount of energy to for normal daily function, and so all the pyruvate produced is once again pushed into the electron transport chain. In addition, all the lactic acid that has built up in the cells begins to be converted back to pyruvate, which then can also be sent to the electron transport chain. Consequently, within a day or two, all the lactic acid that has built up in the cells will have been converted back into pyruvate and all the muscle soreness will be gone.
Meth from Sudafed
As I was taking a Sudafed pill this morning to clear up my sinuses, I was reminded of the presentations that were given regarding drugs and the brief discussion we had afterwards about the synthesis of methamphetamines. The structure of meth is 
this
this And the structure of pseudoephedrine, the active ingrediant in Sudafed is this
Now one can see why we have to sign for buying Sudafed, and we are restricted to the amount we can buy at one time. Or rather, we are not restricted if we go to different stores, but the computer system will red flag us and send our information to some form of law enforcement. It would be easy to manipulate pseudoephedrine into methamphetamine just by reducing the alcohol group by various means (theoretically one way is to bubble hydrogen gas through a solution of pseudoephedrine and paladium or platinum pellets for catalysts).
So the hard part about making meth is not its synthesis. What really is the challenge is isolating pseudoephedrine from the Sudafed pill. The most amount of pseudoephedrine that can be found in a tablet s 240mg, enough for one "hit" of meth, though during the isolation process much meth can be lost if the "chemist" is not careful. If one pill has enough pseudoephedrine for a hit of meth, one may wonder why taking one of thses Sudafed pills doesn't give you the same effect. That alcohol group is enough to change the chemistry of the drug such that the two drugs will not have the same effects at the same doses. But that doesn't mean Sudafed itself cannot be misused as a recreational drug. Take enough of it and you can get F-ed up easily. Anywho, just thought I'd share what I had found on this subject.
Wednesday, July 1, 2009
Camouflage Chemistry/Biology
After my presentation today, Anthony asked a very good question regarding the chemistry of camouflaging. It sparked my interest to look up the subject matter and write my final blog over it. I found a website that explained the science behind camouflaging very well, so I am just going to directly quote it.
'Chameleons change color by manipulating the chromatophores in their sub-dermal layer. Each chromatophore contains one pigment, and a sphincter muscle. When contracted, the pigment is squeezed up into a flat region above the chromatophore, showing that pigment. As you can imagine, this works much like an RGB display; an animal can have only a few pigments, and make many different colors by combining them selectively. Chameleons have four different layers to their skin, in order of increasing depth: the protective epidermis, the chromatophore layer (which contains red and yellow pigments), the melanophore layer which can display brown or black pigments or reflect blue, and the nether layer, which is white. Any given color morph of a species of chameleon only has a few different patterns and color combinations in its palette.
So say the chameleon is frightened by a Boomslang or a Shrike (both predators of chameleons), a combination of hormone action and nerve impulses will selectively expand and contract some chromatophores of the chameleon into either a camouflage pattern or a bright pattern which often means "I taste bad" or "I'm poisonous" in the animal world. These transitions can take as little as a few seconds, and a viewer will see a gradual shift from one color pattern to the other. '
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