Monday, August 2, 2010
Monday, July 19, 2010
Artificial Cells Communicate and Cooperate Like Biological Cells, Ants
Recently reported in the Proceedings of the National Academy of Sciences (PNAS), the research is a significant step toward producing synthetic cells that behave like natural organisms and could perform important, microscale functions in fields ranging from the chemical industry to medicine.
The team presents in the PNAS paper computational models that provide a blueprint for developing artificial cells -- or microcapsules -- that can communicate, move independently, and transport "cargo" such as chemicals needed for reactions. Most importantly, the "biologically inspired" devices function entirely through simple physical and chemical processes, behaving like complex natural organisms but without the complicated internal biochemistry, said corresponding author Anna Balazs, Distinguished Professor of Chemical Engineering in Pitt's Swanson School of Engineering.
In one video of the interaction, as the signaling cell emits the agonist nanoparticles, the target cell responds with antagonists that stop the first cell from secreting. Once the signaling cell goes dormant, the target cell likewise stops releasing antagonists -- which makes the signaling cell start up again. The microcapsules get locked into a cycle that equates to an intercellular conversation, a dialogue humans could control by adjusting the capsules' permeability and the quantity of nanoparticles they contain.
The team presents in the PNAS paper computational models that provide a blueprint for developing artificial cells -- or microcapsules -- that can communicate, move independently, and transport "cargo" such as chemicals needed for reactions. Most importantly, the "biologically inspired" devices function entirely through simple physical and chemical processes, behaving like complex natural organisms but without the complicated internal biochemistry, said corresponding author Anna Balazs, Distinguished Professor of Chemical Engineering in Pitt's Swanson School of Engineering.
In one video of the interaction, as the signaling cell emits the agonist nanoparticles, the target cell responds with antagonists that stop the first cell from secreting. Once the signaling cell goes dormant, the target cell likewise stops releasing antagonists -- which makes the signaling cell start up again. The microcapsules get locked into a cycle that equates to an intercellular conversation, a dialogue humans could control by adjusting the capsules' permeability and the quantity of nanoparticles they contain.
Monday, July 5, 2010
Oil Spills Raise Arsenic Levels in the Ocean,says Research
Arsenic is a poisonous chemical element found in minerals and it is present in oil. High levels of arsenic in seawater can enable the toxin to enter the food chain. It can disrupt the photosynthesis process in marine plants and increase the chances of genetic alterations that can cause birth defects and behavioural changes in aquatic life. It can also kill animals such as birds that feed on sea creatures affected by arsenic.
In the study, a team from Imperial College London has discovered that oil spills can partially block the ocean's natural filtration system and prevent this from cleaning arsenic out of the seawater. The researchers say their study sheds light on a new toxic threat from the Gulf of Mexico oil leak.
Arsenic occurs naturally in the ocean, but sediments on the sea floor filter it out of seawater, which keeps the levels of naturally occurring arsenic low. However, arsenic is also flushed into the ocean in wastewater from oil rigs and from accidental oil spills and leakages from underground oil reservoirs.
In the study, the researchers discovered that oil spills and leakages clog up sediments on the ocean floor with oil, which prevents the sediments from bonding with arsenic and burying it safely underground with subsequent layers of sediment. The scientists say this shutdown of the natural filtration system causes arsenic levels in seawater to rise, which means that it can enter the marine ecosystem, where it becomes more concentrated and poisonous the further it moves up the food chain.
The team carried out experiments in the laboratory that mimicked conditions in the ocean, to see how the goethite binds to arsenic under natural conditions. They discovered that seawater alters the chemistry of goethite, where low pH levels in the water create a positive change on the surface of goethite sediments, making them attractive to the negatively charged arsenic.
In the study, a team from Imperial College London has discovered that oil spills can partially block the ocean's natural filtration system and prevent this from cleaning arsenic out of the seawater. The researchers say their study sheds light on a new toxic threat from the Gulf of Mexico oil leak.
Arsenic occurs naturally in the ocean, but sediments on the sea floor filter it out of seawater, which keeps the levels of naturally occurring arsenic low. However, arsenic is also flushed into the ocean in wastewater from oil rigs and from accidental oil spills and leakages from underground oil reservoirs.
In the study, the researchers discovered that oil spills and leakages clog up sediments on the ocean floor with oil, which prevents the sediments from bonding with arsenic and burying it safely underground with subsequent layers of sediment. The scientists say this shutdown of the natural filtration system causes arsenic levels in seawater to rise, which means that it can enter the marine ecosystem, where it becomes more concentrated and poisonous the further it moves up the food chain.
The team carried out experiments in the laboratory that mimicked conditions in the ocean, to see how the goethite binds to arsenic under natural conditions. They discovered that seawater alters the chemistry of goethite, where low pH levels in the water create a positive change on the surface of goethite sediments, making them attractive to the negatively charged arsenic.
Friday, April 30, 2010
The health dangers of piling up bad habits
At this point, most of us generally have a clue about the basics of staying in good health—eat well, exercise, don't drink too much and don't smoke. And plenty of research has been dedicated to exploring how failing on any of those fronts, or even more than one at a time, can be detrimental to overall health. Yet, for many people, those bad habits have a way of accumulating. And, according to a new study published this week in the Archives of Internal Medicine, their cumulative impact can be pretty grim. In an analysis of nearly 5,000 adults tracked for two decades, researchers found that stacking up these four bad habits can work together to prematurely age you by as much as 12 years.
Overall, 314 people studied had all four unhealthy behaviors. Among them, 91 died during the study, or 29 percent. Among the 387 healthiest people with none of the four habits, only 32 died, or about 8 percent.
Looked at independently, the risky behaviors included smoking, a sedentary lifestyle, little consumption of fruit and vegetables and regular drinking—an average of three drinks per day for men, or two for women. When compared to people who had the most healthy habits—those who never smoked, exercised at least two hours per week, ate plenty of fruits and veggies and didn't drink at all, or drank more moderately, those with all four bad habits had an increased risk of death equivalent to being 12 years older.
Overall, 314 people studied had all four unhealthy behaviors. Among them, 91 died during the study, or 29 percent. Among the 387 healthiest people with none of the four habits, only 32 died, or about 8 percent.
Looked at independently, the risky behaviors included smoking, a sedentary lifestyle, little consumption of fruit and vegetables and regular drinking—an average of three drinks per day for men, or two for women. When compared to people who had the most healthy habits—those who never smoked, exercised at least two hours per week, ate plenty of fruits and veggies and didn't drink at all, or drank more moderately, those with all four bad habits had an increased risk of death equivalent to being 12 years older.
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