A battery powered by urine
I’m having flashbacks to seventh grade science class (one of my favoritest classes ever), and the voltaic pile that we made. Scientists have recently created a battery that is powered by urine, similar to the original voltaic piles, only miniaturized.
I’m not quite sure why this is so amazing given that it’s essentially technology from the 1700s. The device creates electricity via an electrochemical reaction: one side of the paper gains electrons (oxidation) and one side loses electrons (reduction). This redox reaction creates a small amount of voltage, which can be used to power small medical devices such as diabetes monitors. Urine contains glucose, the concentration of which can be used to determine the level of sugar in the blood.
The unit is much smaller than a traditional voltaic pile, but it functions on the same principle:
The battery unit is made from a layer of paper that is steeped in copper chloride (CuCl) and sandwiched between strips of magnesium and copper. This “sandwich” is then held in place by being laminated, which involves passing the battery unit between a pair of transparent plastic films through a heating roller at 120ºC. The final product has dimensions of 60 mm x 30 mm, and a thickness of just 1 mm (a little bit smaller than a credit card).
Writing in the Journal of Micromechanics and Microengineering, Lee describes how the battery was created and quantifies its performance. Using 0.2 ml of urine, they generated a voltage of around 1.5 V with a corresponding maximum power of 1.5 mW. They also found that the battery performances (such as voltage, power or duration) may be designed or adjusted by changing the geometry or materials used.
I guess the more things change, the more they stay the same?
748 days in space
At 748 days, Sergei Krikalev, the commander of the International Space Station, has set a new record for cumulative days in space. Aside from his new record, Krikalev has done some pretty impressive things before this most recent achievement as well.
Krikalev, who was born in Leningrad, Russia, in 1958, won the top national prize for daredevil aerobatic flying in 1986 and later received numerous international honours, including “Hero of Russia”, for his spaceflights. He flew twice to the Russian space station Mir - once staying on for back-to-back six-month tours when one of the subsequent two flights to Mir was cancelled.
He also flew on the first joint US-Russian space shuttle mission in 1994, the first mission to assemble the International Space Station in 1998 and was a member of the first crew to live onboard the ISS in 2000.
Widely considered the best, Krikalev apparently has no fear. Not of bone loss, radiation exposure, being alone, or anything else. Or if these things worry him, he doesn’t let anyone know. Some would argue that for doing the incredible things that he’s done, the stories he could tell are worth the risk. God knows, that’s how I would feel if the loneliness didn’t kill me. After all, who wouldn’t want to go into space? I’m not so sure I’d want to spend two years there, though, especially if I had a family waiting for me back on Earth.
But when Krikalev finally does come home, he will have something to worry about: his physical condition. Radiation exposure in space can alter DNA, creating oncogenes, or cancer precursors. When DNA is damaged by radiation, it is repaired, except that when it is repaired, it can be fixed incorrectly: during repair, the strands are stuck back together and smoothed out, and no comparison to the original strand is made, which can lead to incorrect DNA sequences. (This incorrect repair is also the reason that people can get skin cancer when their skin cells are damaged by UV light.)
Cancer risks aside, cosmonauts and astronauts also sometimes have difficulty adjusting to social life on Earth again. Thus far, Krikalev has been remarkably resilient to the depression-like symptoms that often take hold of space travelers after the initial euphoria and excitement of being in space wear off, so this probably won’t be much of a problem for him, given that he’s done a one-year stint in space before this mission. Not that frequency of occurrence makes social adjustment any easier, of course.
Perhaps the biggest, most immediate health concern is over the density of his bones. Even with methods in place to reduce bone density loss, astronauts and cosmonauts lose an average of 1.5% of their bone density for every month they are in space, and he’s been there for almost 25 months, and it will be 27 months by the time he finally comes back home. The average post-menopausal woman loses about 1.5% of her bone density per year. So in theory if he were a post-menopausal woman, Krikalev will have lost the equivalent of 27 years of bone density when he comes back to Earth. Growing bone-mass back can be achieved, but it is a long process, and it is unknown how the quality of bone mass compares to that which was lost. Recall that bone marrow turns into fat as people age, and Krikalev has done quite a bit of aging in the last 2 years. I wonder if astronauts and/or cosmonauts take any osteoporosis drugs like Fosamax or Actonel? Hrm. I wonder who I could ask that would know…
Update: Bisphononates like risedronate and alendronate have been studied in bedrest studies (physiological equivalents to extended space travel), but not used in space missions.
People don’t eat less to compensate for overeating
I’ve written about obesity in the past, and I couldn’t pass up this particular article I just came across. The basic premise is that if one eats more than usual and gains some weight over the course of, say, a week, one is not inclined to eat less to make up for it. The possible reason cited:
“The study suggests that eating behavior does not normally respond to internal cues, such as physiological mechanisms involved in the regulation of body weight, but to external cues,” said David Levitsky, professor of nutritional sciences and of psychology at Cornell. “In other words, when the subjects returned to the same environment — in this case our eating lab — they returned to their same eating patterns, regardless of any biological signals.”
The results add to the growing evidence that environmental cues, especially portion size, appear to be a major determinant of how much we eat, he said. This finding runs counter to the current view that food intake is largely determined by biological mechanisms.
However, I would posit a more built-in mechanism: evolutionary history. In the past, when humans were primarily hunter-gatherers, a boom time would often be followed by a period of less bounty. It would seem, then, that evolution would select for eating more now and not being worried about eating less later. Gaining a little girth temporarily would allow one to be held over on less, later.
I emailed the author of the report asking for their opinion on the matter, and I am anxiously awaiting their reply.
Money can, in fact, buy you happiness. Sort of.
According to new research, money can buy you happiness, but only if it’s relative to the incomes of others in one’s own peer group. That is, if I make more money than my friend Bob, I’m probably happier than him, and he’s probably more unhappy than me. Of course, this makes pretty good sense, but the paper doesn’t attempt to explain why this is.
So I’m going to take a stab at it in the light of my recent reading.
Human beings are social creatures. Even those that prefer to be alone most of the time require some social interaction — the vast majority of the population falls within the normal bounds of introverted- vs. extroverted-ness. If one were to take a human baby and separate him from society for his whole life, he would not have any social skills and would die relatively quickly. As individuals, we cannot exist for long in isolation. (This is one of the reasons that solitary confinement is generally reserved as a way of punishing prisoners.) Those rare few that truly hate all social interaction are few and far between. The Unabomber comes to mind, but even he likes a bit of intellectual stimulation every once in a while.
Because we are social, we form social groups based on appearance, age, and perhaps most importantly, ideology. Peers tend to be those that have overlapping interests, ages, and ideologies, and so we judge ourselves on how we are relative to them, because they are our mirroring surface. If one is more successful (in whatever way one defines success), one tends to be more self-confident and secure in one’s own abilities and talents. These qualities lend themselves to happiness and contentment. Friends and strangers alike are more drawn to this successful individual because he exudes confidence. This, in turn, makes him more successful, which is a large part of the reason that a well-crafted façade for someone just starting out in business is one of the most important aspects of becoming truly successful. The image and perception of success breeds further success. It is only a simple matter, then to see why those that are more more financially successful than their peers are happier than their peers: because everyone around them appreciates them more, will defer to them (because they’re clearly doing something right), and, in general, admires them.
So it’s not so big of a stretch to see why happiness often mirrors financial success.
The problem of static
Mars has been in the news quite a lot lately, especially with the success of the recent Sojourner landing and “Mars hoax“. Well, the red planet is back in the news again due to an issue that most people — unless you’re in the electronics sector — much on earth: static electricity. On Mars, though, it’s a much bigger problem for two reasons. Firstly, the potential to create an electrical charge is much greater on Mars, than it is on Earth.
When certain pairs of unlike materials, such as wool and hard shoe-sole leather, rub together, one material gives up some of its electrons to the other material. The separation of charge can create a strong electric field.
Here on Earth, the air around us and the clothes we wear usually have enough humidity to be decent electrical conductors, so any charges separated by walking or rubbing have a ready path to ground. Electrons bleed off into the ground instead of accumulating on your body.
NASA will have to overcome this obstacle in order to establish Mars and lunar bases. But the problem isn’t as simple as it might seem at first glance. Here on Earth, the moisture in the air and the ground makes absorbing the excess electrons that build up quite easy. But on Mars (and the moon), there is almost no moisture. An astronaut touching, for instance, the door to a lunar or Mars base could fry the sensitive electrical circuitry in his suit. Apollo astronauts didn’t have this problem, probably because they were not active enough to create the static charges necessarily to create an electrical shock. But astronauts on Mars, using heavy equipment, might.
On Earth, the best ground is, well, the ground. But on Mars, it might well be the martian atmosphere itself, with a little help:
On Mars, the best ground might be, ironically, the air. A tiny radioactive source “such as that used in smoke detectors,” could be attached to each spacesuit and to the habitat, suggests Landis. Low-energy alpha particles would fly off into the rarefied atmosphere, hitting molecules and ionizing them (removing electrons). Thus, the atmosphere right around the habitat or astronaut would become conductive, neutralizing any excess charge.
Solving the same problem on the moon, though, might be a little bit different:
Achieving a common ground on the Moon would be trickier, where there’s not even a rarefied atmosphere to help bleed off the charge. Instead, a common ground might be provided by burying a huge sheet of foil or mesh of fine wires, possibly made of aluminum (which is highly conductive and could be extracted from lunar soil), underneath the entire work area. Then all the habitat’s walls and apparatus would be electrically connected to the aluminum.
As always, more research and testing needs to be done. Regardless, frying space suits is a sure way to get oneself stranded on terra firma far away from home.
From “bugs” to drugs
Wired’s running a story called “Turning Bugs into Drugs.” Unfortunately, the article’s opening two of sentences are almost completely wrong:
The dirty secret of pharmacology is that most medicines don’t work all that well. Stomach acids erode them, the liver filters them out, and the bloodstream shunts them away.
The real dirty secret here is that this is largely incorrect information. While it is true that some drugs’ efficacy is decreased as a result of metabolic processes, the actual truth is that pharmaceutical companies take these effects into consideration while designing drugs. Systemic drugs (those which enter the bloodstream and act on the body as a whole) are often inert in the molecular form that is introduced to the body via tablet, IV, etc. Then, when the body begins metabolizing the compound, the active form of the drug “falls out” so that it can go to work. In other words, it is the byproducts of the body’s metabolic processes that are actually the active forms of their respective drugs. So while the original form might “erode,” this could very well be part of the design.
Granted, not all drugs are like this, especially antibiotics, but many are. This error aside, the article has got some cool information about new drugs in the pipeline made from bacteria.
For cancer patients (these seem pretty out there):
Listeria monocytogenes causes deadly food poisoning, and the immune system responds in force at the first sign of the bacteria’s presence in the body. Stripping the bacteria of toxic genes and substituting ones that make molecules found in tumors may retrain the immune system to go after cancerous cells.
Status: Preliminary human trials later this year
Clostridium novyi is a relative of the bacteria that causes botulism. It doesn’t grow in live tissue at the edges of tumors but thrives deep in their dead interiors (where there’s no oxygen), eventually liquefying them. When the immune system cleans up the mess, it learns to kill living cancer cells.
Status: Animal studies
This cancer-fighter seems within the realm of possibility:
Salmonella typhimurium flourishes in tumors. By adding a gene that converts a relatively innocuous chemical called a prodrug into a toxin, it can be used to fight cancer. The prodrug goes to every cell in the body but only wipes out the ones inside the tumor.
Status: Preliminary human trials
A pet topic of mine since I have Crohn’s:
Lactococcus lactis is the bacteria used to ferment milk to make cheese. Tweak it to make IL-10 [Interleukin-10], and the bug passes through the stomach and makes medicine at the intestinal wall.
Status: Preliminary human trials
Modifying bacteria to make other products in the case of the Crohn’s and the last cancer treatment above has been done for years. E. coli is used to make insulin, for example, and has been made this way for a very long time. It is relatively easy to do because the bacterial genomes are much less complex than the human genome, and making modifications to it is relatively easy. I hope some of these treatments come to fruition.
The impact of celebrity on medicine
At the risk of reading like Us Weekly or People Magazine, I wish to mention some aspects of medicine and pop culture that often get overlooked. I promise I’ll keep it short. The big issue recently brought to light due to Tom Cruise’s recent Scientology shenanigans highlights the impact that celebrities can have on all aspects of society. Cruise’s comments regarding psychiatry — “there’s no such thing as a chemical imbalance” — can alienate Cruise fans from the medical profession those who need psychiatric help the most. Psychiatrists and other practitioners decried Mr. Cruise’s ignorance because it might cause those individuals who need help the most (who, ironically, happen to often be the most impressionable) to not seek it out because it’s “all in their head.” Some people thought that the medical community was overreacting, but I offer this New Scientist article as indirect evidence of the impact celebrity can have on popular opinion regarding health matters and awareness.
Kylie Minogue, for those of you that don’t know, is an actress/pop singer from Australia. Recently diagnosed with breast cancer, Australia was inundated with a media blitz about mammograms and breast cancer screenings as a direct result of Ms. Minogue’s popularity:
Overall, the team found a 40% increase in bookings during the two weeks of intense publicity about Minogue’s diagnosis, but the rate was even higher in women who had never been screened before.
“I don’t think anyone really knew what to expect, but to see a 101% increase in mammogram bookings among previously unscreened women is just remarkable,” says Simon Chapman of the University of Sydney, who led the work. Six weeks after the publicity, bookings remained more than one-third higher among previously unscreened women.
This jumps lends credibility to the idea that celebrities can and do weild an unusual (and often unhealthy) amount of sway over public opinion and their actions can hurt or help as they see fit to use their influence.
Celebrity illnesses can create the sort of media coverage of a disease that advertising budgets cannot buy, Chapman adds. And he thinks health agencies should improve their response to announcements of new diagnoses among celebrities.
Unfortunately, this celebrity influence is a double-edged sword.