New Power Generation Technique: Hybrid Nanomaterial Converts Light and Thermal Energy Into Electrical Current

A University of Texas at Arlington physics professor has helped create a hybrid nanomaterial that can be used to convert light and thermal energy into electrical current, surpassing earlier methods that used either light or thermal energy, but not both.

Working with Louisiana Tech University assistant professor Long Que, UT Arlington associate physics professor Wei Chen and graduate students Santana Bala Lakshmanan and Chang Yang synthesized a combination of copper sulfide nanoparticles and single-walled carbon nanotubes.

The team used the nanomaterial to build a prototype thermoelectric generator that they hope can eventually produce milliwatts of power. Paired with microchips, the technology could be used in devices such as self-powering sensors, low-power electronic devices and implantable biomedical micro-devices, Chen said.

"If we can convert both light and heat to electricity, the potential is huge for energy production," Chen said. "By increasing the number of the micro-devices on a chip, this technology might offer a new and efficient platform to complement or even replace current solar cell technology."

In lab tests, the new thin-film structure showed increases by as much at 80 percent in light absorption when compared to single-walled nanotube thin-film devices alone, making it a more efficient generator.

Copper sulfide is also less expensive and more environment-friendly than the noble metals used in similar hybrids.

In October, the journal Nanotechnology published a paper on the work called "Optical thermal response of single-walled carbon nanotube-copper sulfide nanoparticle hybrid nanomaterials." In it, researchers also say also found that they could enhance the thermal and optical switching effects of the hybrid nanomaterial as much as ten times by using asymmetric illumination, rather than symmetric illumination.

Coauthors on the Nanotechnology paper from Louisiana Tech include Yi-Hsuan Tseng, Yuan He and Que, all of the school's Institute for Micromanufacturing.

"Dr. Chen's research with nanomaterials is an important advancement with the potential for far-reaching applications," said Pamela Jansma, dean of the UT Arlington College of Science. "This is the kind of work that demonstrates the value of a research university in North Texas and beyond."

Chen is currently receiving funding from the U.S. Department of Defense to develop nanoparticle self-lighting photodynamic therapy for use against breast and prostate cancers. In 2010, he was the first to publish results in the journal Nanomedicinedemonstrating that near infrared light could be used to heat copper sulfide nanoparticles for photothermal therapy in cancer treatment, which destroys cancer cells with heat between 41 and 45 degrees Celsius.

Next month, the Journal of Biomedical Nanotechnology will publish Chen's work successfully coupling gold nanoparticles with the copper sulfide nanoparticles for the photothermal therapy. Such a material would be less costly and potentially more effective than using gold particles alone, Chen said.

Journal References:

1.      Santana Bala Lakshmanan, Xiaoju Zou, Marius Hossu, Lun Ma, Chang Yang, Wei Chen. Local Field Enhanced Au/CuS Nanocomposites as Efficient Photothermal Transducer Agents for Cancer Treatment. Journal of Biomedical Nanotechnology, 2012; 8 (6): 883 DOI:10.1166/jbn.2012.1486

2.      Yi-Hsuan Tseng, Yuan He, Santana Lakshmanan, Chang Yang, Wei Chen, Long Que. Optical and thermal response of single-walled carbon nanotube–copper sulfide nanoparticle hybrid nanomaterials.Nanotechnology, 2012; 23 (45): 455708 DOI: 10.1088/0957-4484/23/45/455708

Source:

The above story is reprinted from materials provided by University of Texas at Arlington.

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New Antidote for Smoke-Related Cyanide Toxicity Shows Promise

Smoke inhalation is the major cause of death in fire victims due to cyanide poisoning. However, new research presented at CHEST 2012, the annual meeting of the American College of Chest Physicians, shows that a new antidote, cobinamide, may help reverse the effects of cyanide toxicity.

  

Researchers from multiple institutions, including the University of California Irvine Medical Center, exposed six ventilator-supported New Zealand white rabbits to cold smoke breaths until toxic carbon monoxide levels were achieved, concurrent with intravenous cyanide infusion. Intravenous cobinamide was administered in treatment arm animals and compared with control responses.

Results showed that intravenous cobinamide reversed cyanide toxicity in these animals in the face of smoke-induced carbon monoxide exposure, without evident adverse effects. Researchers concluded that cobinamide shows promise as a potential antidote for cyanide poisoning in smoke inhalation victims and that it could potentially be administered in mass casualty exposure scenarios.

This study was presented during CHEST 2012, the annual meeting of the American College of Chest Physicians, held October 20 -- 25, in Atlanta, Georgia.

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Genetic Link Between Pancreatitis and Alcohol Consumption

A new study published online November 12 in Nature Geneticsreveals a genetic link between chronic pancreatitis and alcohol consumption. Researchers from the University of Pittsburgh School of Medicine and more than 25 other health centers across the United States found a genetic variant on chromosome X near the claudin-2 gene (CLDN2) that predicts which men who are heavy drinkers are at high risk of developing chronic pancreatitis.

This finding enables doctors to identify people with early signs of pancreatitis or an attack of acute pancreatitis who are at very high risk for progressing to chronic pancreatitis, allowing them to take preventative action to slow the development of the disease, and give the pancreas a chance to heal. Once an individual develops pancreatitis it takes several years for the pancreas to deteriorate.

"The discovery that chronic pancreatitis has a genetic basis solves a major mystery about why some people develop chronic pancreatitis and others do not," said David C. Whitcomb, M.D., professor of medicine, cell biology and physiology, and human genetics at the University of Pittsburgh School of Medicine and lead author of the report. "We also knew there was an unexpected higher risk of men developing pancreatitis with alcohol consumption, but until now we weren't sure why. Our discovery of this new genetic variant on chromosome X helps explain this mystery as well."

Over 100,000 Americans suffer from chronic pancreatitis, a progressive inflammatory disease characterized by abdominal pain and permanent damage to the pancreas. Most studies report excessive alcohol consumption as the major risk factor for adult-onset chronic pancreatitis. However, according to Dr. Whitcomb, who also is chief of the Division of Gastroenterology, Hepatology and Nutrition, only 3 percent of individuals who are alcoholics develop chronic pancreatitis, suggesting a pancreas-specific risk factor.

The study was conducted over 10 years and involved more than 2,000 patients, all of whom underwent DNA testing in a study funded by the National Institutes of Health. Researchers discovered that there was a common DNA variant on the X chromosome that is present in 26 percent of men without pancreatitis, but jumps to nearly 50 percent of men diagnosed with alcoholic pancreatitis. Women have two X chromosomes, so most women with the high-risk DNA variant on one X chromosome appear to be protected from alcoholic chronic pancreatitis by the other X chromosome, if it is normal. Men have one X chromosome and one Y chromosome, so if they inherit a high-risk X chromosome, there is no protection.

The factor on chromosome X does not appear to cause pancreatitis, but if pancreatic injury occurs for any reason such as gallstone pancreatitis or abdominal trauma, it is more likely that the person will develop chronic pancreatitis -- especially if they also drink alcohol.

"This information is important because the high-risk chromosome can be identified in patients who drink and have early signs of pancreatic injury," said Dhiraj Yadav, M.D., M.P.H., associate professor of medicine, Division of Gastroenterology, Hepatology and Nutrition at Pitt, and a co-investigator on the study. "If pancreatic injury and acute pancreatitis occur, patients must stop drinking immediately."

Nationally, 16 percent of men drink alcohol at levels defined by the National Institute on Alcohol Abuse and Alcoholism as high risk. Twenty-six percent of these men who drink heavily are at high risk of chronic pancreatitis following pancreas injury. Only 10 percent of women drink alcohol at dangerous levels, and of these only 6 percent have the X chromosome variant on both X chromosomes.

"Previous discoveries show that chronic pancreatitis without alcohol involvement has a strong genetic link. This helps to eliminate the previous stigma that patients with chronic pancreatitis must also be heavy drinkers," added Dr. Whitcomb. "This study proves that there is a genetic element to the disease."

Referrals of at-risk patients are welcome at UPMC and other large academic centers. The Pancreas Clinic within the UPMC Digestive Disorder Center is designed to evaluate patients using genetic and other data to provide treatment that is individualized to each patient. In addition to clinical care, the physician-scientists who staff this clinic are actively involved in teaching physicians and trainees the art and science of personalized medicine for chronic pancreatitis.

Collaborators on this study include Bernie Devlin, Ph.D., Adam Slivka, M.D., Ph.D., Dhiraj Yadav, M.D., M.P.H., Randall E. Brand, M.D., Vijay Singh, M.D., Alyssa M Krasinskas, M.D., all of the University of Pittsburgh; Jill P. Smith, M.D., of Pennsylvania State -- Hershey; John P. Neoptolemos, M.D., of the University of Liverpool; Markus M. Lerch, M.D., of the University of Greifswald; and others.

This research was supported by National Institutes of Health grants DK061451, DK054709, DK063922, MH057881, CA117926, UL1 RR024153 and UL1TR000005.

Journal Reference:

1.      David C Whitcomb, Jessica LaRusch, Alyssa M Krasinskas, Lambertus Klei, Jill P Smith, Randall E Brand, John P Neoptolemos, Markus M Lerch, Matt Tector, Bimaljit S Sandhu, Nalini M Guda, Lidiya Orlichenko, Marilyn S Albert, Roger L Albin, Liana G Apostolova, Steven E Arnold, Clinton T Baldwin, Robert Barber, Lisa L Barnes, Thomas G Beach, Gary W Beecham, Duane Beekly, David A Bennett, Eileen H Bigio, Thomas D Bird, Deborah Blacker, Adam Boxer, James R Burke, Joseph D Buxbaum, Nigel J Cairns, Laura B Cantwell, Chuanhai Cao, Regina M Carney, Steven L Carroll, Helena C Chui, David G Clark, David H Cribbs, Elizabeth A Crocco, Carlos Cruchaga, Charles DeCarli, F Yesim Demirci, Malcolm Dick, Dennis W Dickson, Ranjan Duara, Nilufer Ertekin-Taner, Kelley M Faber, Kenneth B Fallon, Martin R Farlow, Steven Ferris, Tatiana M Foroud, Matthew P Frosch, Douglas R Galasko, Mary Ganguli, Marla Gearing, Daniel H Geschwind, Bernardino Ghetti, John R Gilbert, Sid Gilman, Jonathan D Glass, Alison M Goate, Neill R Graff-Radford, Robert C Green, John H Growdon, Hakon Hakonarson, Kara L Hamilton-Nelson, Ronald L Hamilton, Lindy E Harrell, Elizabeth Head, Lawrence S Honig, Christine M Hulette, Bradley T Hyman, Gregory A Jicha, Lee-Way Jin, Gyungah Jun, M Ilyas Kamboh, Anna Karydas, Jeffrey A Kaye, Ronald Kim, Edward H Koo, Neil W Kowall, Joel H Kramer, Patricia Kramer, Walter A Kukull, Frank M LaFerla, James J Lah, James B Leverenz, Allan I Levey, Ge Li, Chiao-Feng Lin, Andrew P Lieberman, Oscar L Lopez, Kathryn L Lunetta, Constantine G Lyketsos, Wendy J Mack, Daniel C Marson, Eden R Martin, Frank Martiniuk, Deborah C Mash, Eliezer Masliah, Ann C McKee, Marsel Mesulam, Bruce L Miller, Carol A Miller, Joshua W Miller, Thomas J Montine, John C Morris, Jill R Murrell, Adam C Naj, John M Olichney, Joseph E Parisi, Elaine Peskind, Ronald C Petersen, Aimee Pierce, Wayne W Poon, Huntington Potter, Joseph F Quinn, Ashok Raj, Murray Raskind, Eric M Reiman, Barry Reisberg, Christiane Reitz, John M Ringman, Erik D Roberson, Howard J Rosen, Roger N Rosenberg, Mary Sano, Andrew J Saykin, Julie A Schneider, Lon S Schneider, William W Seeley, Amanda G Smith, Joshua A Sonnen, Salvatore Spina, Robert A Stern, Rudolph E Tanzi, John Q Trojanowski, Juan C Troncoso, Debby W Tsuang, Otto Valladares, Vivianna M Van Deerlin, Linda J Van Eldik, Badri N Vardarajan, Harry V Vinters, Jean Paul Vonsattel, Li-San Wang, Sandra Weintraub, Kathleen A Welsh-Bohmer, Jennifer Williamson, Randall L Woltjer, Clinton B Wright, Steven G Younkin, Chang-En Yu, Lei Yu, Samer Alkaade, Stephen T Amann, Michelle A Anderson, John Baillie, Peter A Banks, Darwin Conwell, Gregory A Coté, Peter B Cotton, James DiSario, Lindsay A Farrer, Chris E Forsmark, Marianne Johnstone, Timothy B Gardner, Andres Gelrud, William Greenhalf, Jonathan L Haines, Douglas J Hartman, Robert A Hawes, Christopher Lawrence, Michele Lewis, Julia Mayerle, Richard Mayeux, Nadine M Melhem, Mary E Money, Thiruvengadam Muniraj, Georgios I Papachristou, Margaret A Pericak-Vance, Joseph Romagnuolo, Gerard D Schellenberg, Stuart Sherman, Peter Simon, Vijay P Singh, Adam Slivka, Donna Stolz, Robert Sutton, Frank Ulrich Weiss, C Mel Wilcox, Narcis Octavian Zarnescu, Stephen R Wisniewski, Michael R O'Connell, Michelle L Kienholz, Kathryn Roeder, M Michael Barmada, Dhiraj Yadav, Bernie Devlin. Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis. Nature Genetics, 2012; DOI: 10.1038/ng.2466

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Children’s Headaches Rarely Indicate a Need for Eyeglasses, Study Finds

A new study provides the first clear evidence that vision or eye problems are rarely the cause of recurring headaches in children, even if the headaches usually strike while the child is doing schoolwork or other visual tasks. Many parents assume that frequent headaches mean their child needs glasses, so they ask their doctor to refer their child for an eye exam. This study was conducted by pediatric ophthalmologists who wanted to find reliable answers for parents, family doctors and pediatricians facing this common health question.

The research is being presented today at the 116th Annual Meeting of the American Academy of Ophthalmology, conducted jointly this year with the Asia-Pacific Academy of Ophthalmology.

In this retrospective study, which was conducted at the ophthalmology clinic of Albany Medical Center in New York state, researchers reviewed the medical records of 158 children under age 18 who were seen at the clinic for frequent headaches from 2002-11. All of the children received complete eye exams by the clinic's ophthalmologists.

No significant correlation was found between their frequent headaches and a need for vision correction. The researchers reached this conclusion by comparing the results of the clinic's exams of the children with headaches to the records of their previous eye exams and other relevant medical care. Eye health and vision test results remained unchanged from earlier exams for 75 percent of the children. Also, children who already had eyeglasses were not found to need new prescriptions at the time they were seen at the clinic for headaches. Although about 14 percent of the children reported that their headaches occurred while doing visual tasks like homework, and about nine percent reported visual symptoms associated with their headaches, a need for vision correction did not appear to be the primary cause or a significant factor in any of these cases, according to the study.

The researchers considered it positive that most of the children's headaches resolved over time. Follow up reports from parents showed that headaches improved in 76.4 percent of all study subjects, including those who did and those who did not receive new vision correction prescriptions. Children who received new prescriptions were not more likely than others to have their headaches improve. Assessing the causes of the headaches and addressing the children's long-term outcomes were beyond the scope of this study.

"We hope our study will help reassure parents that in most cases their children's headaches are not related to vision or eye problems, and that most headaches will clear up in time," said Zachary Roth, M.D., who led the research team. "The information should also be useful to family doctors and pediatricians in caring for children and parents who have this common health concern."

About thirty percent of the children in the study had eye conditions that went beyond the need for vision correction, including strabismus (misaligned eyes) amblyopia ("lazy eye") or other rarer, more serious conditions. Seventeen percent had a family history of migraine. Because this was a retrospective study, the researchers were unable to connect these factors with headache causes.

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Limiting Carbs to Dinner-Time Increases Satiety, Reduces Risk for Diabetes and Cardiovascular Disease, Research Finds

An experimental diet with carbohydrates eaten mostly at dinner could benefit people suffering from severe and morbid obesity, according to new research at the Hebrew University of Jerusalem. 

The diet influences secretion patters of hormones responsible for hunger and satiety, as well as hormones associated with metabolic syndrome. In this way the diet can help dieters persist over the long run, and reduce risk factors for diabetes and cardiovascular disease.

The research was carried out by research student Sigal Sofer under the auspices of Prof. (Emeritus) Zecharia Madar, at the Institute of Biochemistry, Food Science and Nutrition at the Hebrew University's Robert H. Smith Faculty of Agriculture, Food and Environment. (Prof. Madar is now Chief Scientist at Israel's Ministry of Education.)

Sofer randomly assigned 78 police officers to either the experimental diet (carbohydrates at dinner) or a control weight loss diet (carbohydrates throughout the day). 63 subjects finished the six-month program.

The researchers examined the experimental diet's effect on the secretion of three hormones: leptin, considered to be the satiety hormone, whose level in the blood is usually low during the day and high during the night; ghrelin, considered the hunger hormone, whose level in the blood is usually high during the day and low during the night; and adiponectin, considered the link between obesity, insulin resistance and the metabolic syndrome, whose curve is low and flat in obese people.

"The idea came about from studies on Muslims during Ramadan, when they fast during the day and eat high-carbohydrate meals in the evening, that showed the secretion curve of leptin was changed," explained Prof. Madar.

The researchers found that the innovative dietary manipulation led to changes in daylight hormonal profiles in favor of the dieters: the satiety hormone leptin's secretion curve became convex during daylight hours with a nadir in the late day; the hunger hormone ghrelin's secretion curve became concave, peaking only in the evening hours; and the curve of adiponectin, considered the link between obesity, insulin resistance and the metabolic syndrome, was elevated. At the same time this dietary pattern led to lower hunger scores, and better anthropometric (weight, abdominal circumference and body fat), biochemical (blood sugar, blood lipids) and inflammatory outcomes compared to the control group.

The findings suggest there is an advantage in concentrating carbohydrate intake in the evening, especially for people at risk of developing diabetes or cardiovascular disease due to obesity. "The findings lay the basis for a more appropriate dietary alternative for those people who have difficulty persisting in diets over time," said Prof. Madar. "The next step is to understand the mechanisms that led to the results obtained."

The study was published in two continuous papers: "Greater weight loss and hormonal changes after 6 months diet with carbohydrates eaten mostly at dinner" (published in Obesity) and "Changes in daily leptin, ghrelin and adiponectin profiles following a diet with carbohydrates eaten at dinner in obese subjects" (published in Nutrition, Metabolism & Cardiovascular Diseases).

Sources of support for the study include Meuhedet Medical Services, Israel; the Israeli Police Force; the Kaplan Medical Center in Rehovot, Israel (for Dr. Fink); the Israel Diabetes Association; and the Israel Lung and Tuberculosis Association (for Prof. Eliraz).

Journal References:

1.      S. Sofer, A. Eliraz, S. Kaplan, H. Voet, G. Fink, T. Kima, Z. Madar. Changes in daily leptin, ghrelin and adiponectin profiles following a diet with carbohydrates eaten at dinner in obese subjects.Nutrition, Metabolism and Cardiovascular Diseases, 2012; DOI: 10.1016/j.numecd.2012.04.008

2.      Sigal Sofer, Abraham Eliraz, Sara Kaplan, Hillary Voet, Gershon Fink, Tzadok Kima, Zecharia Madar. Greater Weight Loss and Hormonal Changes After 6 Months Diet With Carbohydrates Eaten Mostly at Dinner.Obesity, 2011; 19 (10): 2006 DOI: 10.1038/oby.2011.48

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Meet Xenoceratops: Canada's Newest Horned Dinosaur

Scientists have named a new species of horned dinosaur (ceratopsian) from Alberta, Canada. Xenoceratops foremostensis (Zee-NO-Sare-ah-tops) was identified from fossils originally collected in 1958. Approximately 20 feet long and weighing more than 2 tons, the newly identified plant-eating dinosaur represents the oldest known large-bodied horned dinosaur from Canada.

Research describing the new species is published in the October 2012 issue of the Canadian Journal of Earth Sciences.

"Starting 80 million years ago, the large-bodied horned dinosaurs in North America underwent an evolutionary explosion," said lead author Dr. Michael Ryan, curator of vertebrate paleontology at The Cleveland Museum of Natural History. "Xenoceratops shows us that even the geologically oldest ceratopsids had massive spikes on their head shields and that their cranial ornamentation would only become more elaborate as new species evolved."

Xenoceratops (Xeno + ceratops) means "alien horned-face," referring to the strange pattern of horns on its head and the scarcity of horned dinosaur fossils from this part of the fossil record. It also honors the Village of Foremost, located close to where the dinosaur was discovered.Xenoceratops had a parrot-like beak with two long brow horns above its eyes. A large frill protruded from the back of its skull featuring two huge spikes.

"Xenoceratops provides new information on the early evolution of ceratopsids, the group of large-bodied horned dinosaurs that includes Triceratops," said co-author Dr. David Evans of the Royal Ontario Museum and University of Toronto. "The early fossil record of ceratopsids remains scant, and this discovery highlights just how much more there is to learn about the origin of this diverse group."

The new dinosaur is described from skull fragments from at least three individuals from the Foremost Formation originally collected by Dr. Wann Langston Jr. in the 1950s, and is currently housed in the Canadian Museum of Nature in Ottawa, Canada. Ryan and Evans stumbled upon the undescribed material more than a decade ago and recognized the bones as a new type of horned dinosaur. Evans later discovered a 50-year-old plaster field jacket at the Canadian Museum of Nature containing more skull bones from the same fossil locality and had them prepared in his lab at the Royal Ontario Museum.

This dinosaur is just the latest in a series of new finds being made by Ryan and Evans as part of their Southern Alberta Dinosaur Project, which is designed to fill in gaps in our knowledge of Late Cretaceous dinosaurs and study their evolution. This project focuses on the paleontology of some of the oldest dinosaur-bearing rocks in Alberta, which is less intensely studied than that of the famous badlands of Dinosaur Provincial Park and Drumheller.

"This discovery of a previously unknown species also drives home the importance of having access to scientific collections," says co-author Kieran Shepherd, curator of paleobiology for the Canadian Museum of Nature, which holds the specimen. "The collections are an untapped source of new material for study, and offer the potential for many new discoveries."

Xenoceratops was identified by a team comprising palaeontologists Dr. Michael J. Ryan, curator of vertebrate paleontology at The Cleveland Museum of Natural History; and Dr. David Evans, curator, vertebrate palaeontology of the Department of Natural History at the Royal Ontario Museum; as well as Kieran Shepherd, curator of paleobiology for the Canadian Museum of Nature.

Journal Reference:

1.      Michael J. Ryan, David C. Evans, Kieran M. Shepherd, Hans Sues. A new ceratopsid from the Foremost Formation (middle Campanian) of Alberta. Canadian Journal of Earth Sciences, 2012; 49 (10): 1251 DOI:10.1139/e2012-056

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Active Video Gaming Linked With Higher Energy Expenditure in Children

Compared with rest and sedentary video game play, active video gaming with dancing and boxing were associated with increased heart rate, oxygen uptake and energy expenditure in a study of 18 school children in England, according to a report published Online First by Archives of Pediatrics & Adolescent Medicine, a JAMA Network publication.

Low levels of physical activity have been linked to obesity. Active video game playing compared with traditional sedentary video game playing encourages more movement and could help children increase their physical activity levels, according to the study background.

Stephen R. Smallwood, M.Sc., and colleagues from the University of Chester, England, examined the physiologic responses and energy expenditure of active video gaming using a video game with a webcam-style sensor device and software technology that allows the player to interact directly without the need for a game controller, the authors explain in the background. The study included 10 boys and eight girls ages 11 to 15 years.

"Significant increases were observed in heart rate, VO₂ [oxygen uptake] and energy expenditure during all gaming conditions compared with both rest and sedentary game play," the authors comment.

The games, Dance Central andKinect Sports Boxing, increased energy expenditure by 150 percent and 263 percent, respectively, above resting values and were 103 percent and 194 percent higher than traditional video gaming, according to the study.

"Although it is unlikely that active video game play can single-handedly provide the recommended amount of physical activity for children or expend the number of calories required to prevent or reverse the obesity epidemic, it appears from the results of this study that Kinect active game play can contribute to children's physical activity levels and energy expenditure, at least in the short term," the authors conclude. 

Journal Reference:

1.      Stephen R. Smallwood, Michael M. Morris, Stephen J. Fallows, John P. Buckley. Physiologic Responses and Energy Expenditure of Kinect Active Video Game Play in Schoolchildren. Arch Pediatr Adolesc Med., September 24, 2012 DOI: 10.1001/archpediatrics.2012.1271

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