GEN-ERIC News

A single solar cell produces a relatively low output – it’s a case of strength in numbers. Tiny strips of metal are used to link cells together. If the laser soldering temperature is too high, the solder joint may fracture. A new system provides automatic temperature regulation. Teamwork is what matters – even in the case of solar cells: To obtain sufficient power to operate a pocket calculator, parking ticket dispenser or photovoltaic module, sunlight has to be captured simultaneously by an array of cells. They are connected in series using tiny strips of metal known as stringers. Each stringer has to be positioned in precisely the right spot, then its solder coating is melted using a hot electrode. Researchers at the Fraunhofer Institute for Laser Technology have developed a non-contact soldering system in which the temperature is constantly monitored.

Almost immediately after it is donated, human blood begins to lose a key gas that opens up blood vessels to facilitate the transfer of oxygen from red blood cells to oxygen-starved tissues. Thus, millions of patients are apparently receiving transfusions with blood that is impaired in its ability to deliver oxygen, according to Duke University Medical Center researchers, who reported the results of their studies in two separate papers appearing early on-line in the Proceedings of the National Academy of Sciences. They also found that adding this gas back to stored blood before transfusion appears to restore red blood cells’ ability to transfer oxygen to tissues. These studies go a long way toward answering a major problem which many physicians are beginning to appreciate – blood transfusions with banked human blood may do more harm than good for a majority of patients, according to the researchers. Over the past five years, many studies, including some performed at Duke, have demonstrated that patients who receive blood transfusions have higher incidences of heart attack, heart failure, stroke and even death. While it is known that the banked blood is not the same as blood in the body, the reasons behind blood’s association with worse outcomes have not been well-understood. The key to the current findings is that nitric oxide in red blood cells is crucial to the delivery of oxygen to tissues. Nitric oxide keeps the blood vessels open. The new studies demonstrated that nitric oxide in red blood cells begins breaking down almost immediately after red blood cells leave the body.

Inside the cell nucleus, all our genetic information is located on twisted, double stranded molecules of DNA which are packaged into chromosomes. At the end of these chromosomes are telomeres, zones of repeated chains of DNA that are often compared to the plastic tips on shoelaces because they prevent chromosomes from fraying, and thus genetic information from getting scrambled when cells divide. The telomere is like a cellular clock, because every time a cell divides, the telomere shortens. After a cell has grown and divided a few dozen times, the telomeres turn on an alarm system that prevents further division. If this clock doesn’t function right, cells either end up with damaged chromosomes or they become “immortal” and continue dividing endlessly – either way it’s bad news and leads to cancer or disease. Understanding how telomeres function, and how this function can potentially be manipulated, is thus extremely important. The DNA in the chromosome acts like a sort of instruction manual for the cell. Genetic information is transcribed into segments of RNA that then go out into the cell and carry out a variety of tasks such as making proteins, catalyzing chemical reactions, or fulfilling structural roles. It was thought that telomeres were “silent” – that their DNA was not transcribed into strands of RNA. The researchers have turned this theory on its head by discovering telomeric RNA and showing that this RNA is transcribed from DNA on the telomere.