Tag Archives: brown university

Touch of Gold Improves Nanoparticle Fuel-Cell Reactions

By Guest PostMarch 13, 2012Scienceadvanced electron microscopy, brown university, carbon monoxide, catalyst, co, crystal structure, crystallization, feptau, formic acid, fuel cell reaction, gold, gold atom, helmets, huiyuan zhu, japanese firefighters, mass activity, metallic nanoparticle, nanoparticle catalyst, np, organic material, oxidation, palladium, sen zhang, shaojun guo, shouheng sun, tetragonal, trimetallic nanoparticle

Chemists at Brown University have created a triple-headed metallic nanoparticle that reportedly performs better and lasts longer than any other nanoparticle catalyst studied in fuel-cell reactions. The key is the addition of gold: It yields a more uniform crystal structure while removing carbon monoxide from the reaction. Results published in the Journal of the American Chemical Society.

PROVIDENCE, R.I. [Brown University] — Advances in fuel-cell technology have been stymied by the inadequacy of metals studied as catalysts. The drawback to platinum, other than cost, is that it absorbs carbon monoxide in reactions involving fuel cells powered by organic materials like formic acid. A more recently tested metal, palladium, breaks down over time. (more…)

Will a Genetic Mutation Cause Trouble? Ask Spliceman

By Guest PostMarch 5, 2012Scienceaaa, ata, brown university, chimpanzees, david orenstein, dna sequences, gene, genetic mutation, human genome mutation database, humans, kian huat lim, messenger rna, Rhesus monkeys, shamil sunyaev, spliceman, web based program, william fairbrother

New, free Web-based software described in the journal Bioinformatics analyzes DNA sequences to determine if mutations are likely to cause errors in splicing of messenger RNA. When gene splicing goes awry, a wide variety of diseases can result.

PROVIDENCE, R.I. [Brown University] — In a brief paper in the journal Bioinformatics, Brown University researchers describe a new, freely available Web-based program called Spliceman for predicting whether genetic mutations are likely to disrupt the splicing of messenger RNA, potentially leading to disease.

“Spliceman takes a set of DNA sequences with point mutations and computes how likely these single nucleotide variants alter splicing phenotypes,” write co-authors Kian Huat Lim, a graduate student, and William Fairbrother, assistant professor of biology, in an “application note” published in advance online Feb. 10. It will appear in print in April. (more…)

Ross Levine: Finance and Baseball

By Guest PostMarch 1, 2012Economyballs and strikes, baseball, brown university, deborah baum, economist, electronic monitoring, federal reserve, financial crises, financial markets, financial meltdown, gerard caprio, grand poobahs, guardians of finance, home crowd, homicide, james r barth, l jon wertheim, public, regulatory agencies, ross levine, scorecasting, the sentinel, tobias j moskowitz, united states

In Guardians of Finance, economists Ross Levine, James R. Barth, and Gerard Caprio Jr. argue that the financial meltdown of 2007 to 2009 was no accident — it was negligent homicide. Levine speaks with Deb Baum about how that happened, what can be done, and why the home team always seems to win.

A new book co-authored by Brown University economist Ross Levine argues that the reason the United States suffers financial crises time and time again is because the major regulatory agencies — the so-called “guardians of finance” — do not work for the public. Instead, they frequently work in the best interests of the financial services industry, the very entities they are supposed to be regulating. Guardians of Finance: Making Regulators Work for Us, published in February by MIT Press, goes beyond telling us what went wrong. The authors also suggest reforms needed to prevent the next crisis. (more…)

Researchers Make Living Model of Brain Tumor

By Guest PostFebruary 20, 2012Science3 d characteristics, 3 d model, 3d glioma model, agarose hydrogel mold, anti therapeutic agent, aruna sigdel, blood vessel, brain tumor, brown university, chenjie xu, concept, diameter, diffusion, don ho, endothelial cell, glioma, iron oxide nanoparticles, jeffrey morgan, magnetic resonance imaging, microns, microtissues, nanocarrier, nathan kohler, petri dish, raghu kalluri, rat, rg2 cell gliomas, richard lewis, shouheng sun, tissue culture, tissue model, tumstatin

*Researchers have created a living 3-D model of a brain tumor and its surrounding blood vessels. In experiments, the scientists report that iron-oxide nanoparticles carrying the agent tumstatin were taken by blood vessels, meaning they should block blood vessel growth. The living-tissue model could be used to test the effectiveness of nanoparticles in fighting other diseases. Results appear in Theranostics.*

PROVIDENCE, R.I. [Brown University] — Brown University scientists have created the first three-dimensional living tissue model, complete with surrounding blood vessels, to analyze the effectiveness of therapeutics to combat brain tumors. The 3-D model gives medical researchers more and better information than Petri dish tissue cultures.

The researchers created a glioma, or brain tumor, and the network of blood vessels that surrounds it. In a series of experiments, the team showed that iron-oxide nanoparticles ferrying the chemical tumstatin penetrated the blood vessels that sustain the tumor with oxygen and nutrients. The iron-oxide nanoparticles are important, because they are readily taken up by endothelial cells and can be tracked by magnetic resonance imaging. (more…)

‘Explorers’ Use Uncertainty And Specific Area of Brain

By Guest PostFebruary 11, 2012Scienceambiguity, architecture, bradley doll, brain, brown university, cognitive control, computational power, data, david badre, decision making strategy, explorers, function, functional architecture, mathematical model, michael frank, mri scanner, mystery, nicole long, nonexplorers, rostrolateral prefrontal cortex, status quo, thought process, uncertainty, virtual clock

*As they try to find the best reward among options, some people explore based on how uncertain they are about the outcome of the options. Those who employ that thought process, unlike people who use other strategies, uniquely harness the computational power of the rostrolateral prefrontal cortex, a new study finds.*

PROVIDENCE, R.I. [Brown University] — Life shrouds most choices in mystery. Some people inch toward a comfortable enough spot and stick close to that rewarding status quo. Out to dinner, they order the usual. Others consider their options systematically or randomly. But many choose to grapple with the uncertainty head on. “Explorers” order the special because they aren’t sure they’ll like it. It’s a strategy of maximizing rewards by discovering whether as yet unexplored options might yield better returns. In a new study, Brown University researchers show that such explorers use a specific part of their brain to calculate the relative uncertainty of their choices, while non-explorers do not. (more…)

Lecture or Listen: When Patients Waver on Meds

By Guest PostFebruary 5, 2012Healthadherence, aids and behavior, antiretroviral therapy, arv drugs, arv medication, Baltimore, brown university, detroit, hiv-positive, m barton laws, mary catherine beach, new york city, patient, portland, william rogers, yoojin lee

*According to a new analysis of hundreds of recorded office visits, doctors and nurse practitioners typically issued orders and asked closed or leading questions when talking to their HIV-positive patients about adherence to antiretroviral therapy. Attempts at problem-solving with patients who had lapsed occurred in less than a quarter of visits.*

PROVIDENCE, R.I. [Brown University] — Take your medicine, Doctor’s orders. It’s a simple idea that may seem especially obvious when the pills are the antiretroviral (ARV) drugs that add decades to the lives of HIV-positive patients. But despite the reality that keeping up with drug regimens is not easy for many patients, a new analysis of hundreds of recorded doctor’s office visits finds that physicians and nurse practitioners often still rely on lecturing, ordering, and scolding rather than listening and problem solving with their patients. (more…)

In Lab, Pannexin1 Restores Tight Binding of Cells Lost in Cancer

By Guest PostJanuary 31, 2012Health, Science3d petri dish, 3d system, accelerating effect, actin, biomechanical role, brain tumor, brian bao, brown university, c6, cancerous cell, carbenoxolone, charles lai, christian naus, drug, glioma, gross multicellular behavior, jeffrey morgan, mechanical integrity, molecule atp, pannexin1, probenecid, protein, rat, receptor, scaffold free, Technology, tissue, tumor cell

*By studying tumor cell behavior in a novel “scaffold-free” 3-D system, researchers have determined that the protein Pannexin1 may play an important biomechanical role in binding tissues together, an effect that is lost in cancerous cells.*

PROVIDENCE, R.I. [Brown University] — First there is the tumor and then there’s the horrible question of whether the cancerous cells will spread. Scientists increasingly believe that the structural properties of the tumor itself, such as how tightly the tumor cells are packed together, play a decisive role in the progression of the disease. In a new study, researchers show that the protein Pannexin1, known to have tumor-suppressive properties, plays an important role in keeping the cells within a tissue closely packed together, an effect that may be lost with cancer.

“In healthy tissues, the recently discovered protein Pannexin1 may be playing an important role in upholding the mechanical integrity of the tissue,” said first author and Brown University M.D./Ph.D. student Brian Bao. “When we develop cancer, we lose Pannexin1 and we lose this integrity.” (more…)

Biochip Measures Glucose in Saliva, Not Blood

By Guest PostJanuary 22, 2012Sciencealec roelke, americans, biochip, biological device, blood, brown university, chip, convergence, diabetics, domenico pacifici, environmental substances, glucose concentration, glucose levels, grooves, human hair, human saliva, interaction of electrons, interference, jing feng, light, light intensity, maxima and minima, measure, microfluidic channels, milligrams per deciliter, Nanotechnology, ocean waves, photons, plasmonic interferometers, steve rhieu, surface plasmon polariton, surface plasmon waves, surface plasmonics, tayhas palmore, vihang mehta, vince siu, wavelength

*Engineers at Brown University have designed a biological device that can measure glucose concentrations in human saliva. The technique could eliminate the need for diabetics to draw blood to check their glucose levels. The biochip uses plasmonic interferometers and could be used to measure a range of biological and environmental substances. Results are published in Nano Letters.*

PROVIDENCE, R.I. [Brown University] — For the 26 million Americans with diabetes, drawing blood is the most prevalent way to check glucose levels. It is invasive and at least minimally painful. Researchers at Brown University are working on a new sensor that can check blood sugar levels by measuring glucose concentrations in saliva instead.

The technique takes advantage of a convergence of nanotechnology and surface plasmonics, which explores the interaction of electrons and photons (light). The engineers at Brown etched thousands of plasmonic interferometers onto a fingernail-size biochip and measured the concentration of glucose molecules in water on the chip. Their results showed that the specially designed biochip could detect glucose levels similar to the levels found in human saliva. Glucose in human saliva is typically about 100 times less concentrated than in the blood. (more…)