Hydrogen Bond Dynamics Near A Micellar Surface: Origin of the Universal Slow Relaxation at Complex Aqueous Interfaces

The dynamics of hydrogen bonds among water molecules themselves and with the polar head groups (PHG) at a micellar surface have been investigated by long molecular dynamics simulations. The lifetime of the hydrogen bond between a PHG and a water molecule is found to be much longer than that between any two water molecules, and is likely to be a general feature of hydrophilic surfaces of organized assemblies. Analyses of individual water trajectories suggest that water molecules can remain bound to the micellar surface for more than a hundred picosecond. The activation energy for such a transition from the bound to a free state for the water molecules is estimated to be about 3.5kcal/mole.Comment: 12 pages. Phys. Rev. Lett. (Accepted) (2002

Analog and digital simulations of multiplex system performance

Analog and digital simulations of multiplex system performanc

Comparison of human B cell activation by TLR7 and TLR9 agonists

Research articl

Mild hypothermia delays the development of stone heart from untreated sustained ventricular fibrillation - a cardiovascular magnetic resonance study

<p>Abstract</p> <p>Background</p> <p>'Stone heart' resulting from ischemic contracture of the myocardium, precludes successful resuscitation from ventricular fibrillation (VF). We hypothesized that mild hypothermia might slow the progression to stone heart.</p> <p>Methods</p> <p>Fourteen swine (27 ± 1 kg) were randomized to normothermia (group I; n = 6) or hypothermia groups (group II; n = 8). Mild hypothermia (34 ± 2°C) was induced with ice packs prior to VF induction. The LV and right ventricular (RV) cross-sectional areas were followed by cardiovascular magnetic resonance until the development of stone heart. A commercial 1.5T GE Signa NV-CV/i scanner was used. Complete anatomic coverage of the heart was acquired using a steady-state free precession (SSFP) pulse sequence gated at baseline prior to VF onset. Un-gated SSFP images were obtained serially after VF induction. The ventricular endocardium was manually traced and LV and RV volumes were calculated at each time point.</p> <p>Results</p> <p>In group I, the LV was dilated compared to baseline at 5 minutes after VF and this remained for 20 minutes. Stone heart, arbitrarily defined as LV volume <1/3 of baseline at the onset of VF, occurred at 29 ± 3 minutes. In group II, there was less early dilation of the LV (p < 0.05) and the development of stone heart was delayed to 52 ± 4 minutes after onset of VF (P < 0.001).</p> <p>Conclusions</p> <p>In this closed-chest swine model of prolonged untreated VF, hypothermia reduced the early LV dilatation and importantly, delayed the onset of stone heart thereby extending a known, morphologic limit of resuscitability.</p

A robust method to quantify low molecular weight contaminants in heparin: detection of tris(2-n-butoxyethyl) phosphate

Recently, oversulfated chondroitin sulfate (OSCS) was identified in contaminated heparin preparations, which were linked to several adverse clinical events and deaths. Orthogonal analytical techniques, namely nuclear magnetic resonance (NMR) and capillary electrophoresis (CE), have since been applied by several authors for the evaluation of heparin purity and safety. NMR identification and quantification of residual solvents and non-volatile low molecular contaminants with USP acceptance levels of toxicity was achieved 40-fold faster than the traditional GC-headspace technique, which takes similar to 120 min against similar to 3 min to obtain a (1)H NMR spectrum with a signal/noise ratio of at least 1000/1. the procedure allowed detection of Class 1 residual solvents at 2 ppm and quantification was possible above 10 ppm. 2D NMR techniques (edited-HSQC (1)H/(13)C) permitted visualization of otherwise masked EDTA signals at 3.68/59.7 ppm and 3.34/53.5 ppm, which may be overlapping mononuclear heparin signals, or those of ethanol and methanol. Detailed NMR and ESI-MS/MS studies revealed a hitherto unknown contaminant, tris(2-n-butoxyethyl) phosphate (TBEP), which has potential health risks.Brazilian agency Fundacao AraucariaBrazilian agency FINEP (PRONEX-CARBOIDRATOS, PADCT II/SBIO)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed Parana, Dept Bioquim & Biol Mol, BR-81531980 Curitiba, PR, BrazilIst Ric Chim & Biochim G Ronzoni, I-20133 Milan, ItalyUniversidade Federal de São Paulo, Dept Bioquim & Biol Mol, BR-04044020 São Paulo, SP, BrazilUniv Liverpool, Sch Biol Sci, Liverpool L69 7ZB, Merseyside, EnglandUniversidade Federal de São Paulo, Dept Bioquim & Biol Mol, BR-04044020 São Paulo, SP, BrazilWeb of Scienc

Energy Technology Transfer for Industry Through the Texas Energy Extension Service

The Texas Energy Extension Service (EES) is one of ten Department of Energy funded pilot programs designed to test methods for assisting small energy users to reduce energy costs. A major thrust of EES in Texas is directed toward providing assistance to Texas manufacturers. This takes the form of responding to requests for technical information and conducting plant visits to energy intensive small manufacturers. An evaluation of program effectiveness and assessment of participants' needs has recently been conducted. The evaluation/needs assessment suggests that specific conservation information when delivered by credible organizations is acted upon and leads to reductions in energy costs

Novel Two-Stage Fine Milling Enables High-Throughput Determination of Glyphosate Residues in Raw Agricultural Commodities

Abstract Dramatic process-efficiency gains for residue analysis of glyphosate in raw agricultural commodities (RACs) were achieved by development and validation of a two-stage fine-milling process. This secondary milling produced a uniform and consistent product that could be reproducibly measured with 75 mg analytical test portions. The milligram scale sample size enabled the direct weighing of sample into a liquid-handler-compatible 96-well format. A high-throughput workflow based on this innovative comminution approach for the quantitation of glyphosate, a nonselective herbicide, and its main degradation product, aminomethylphosphonic acid, was validated in various RACs and used to demonstrate the applicability of the two-step milling process. The precision and reproducibility of 75 mg analytical portions taken through this assay was used to demonstrate the feasibility of using a two-stage fine-milling technique for pesticide residue applications. An RSD of less than 10% was achieved in endogenous glyphosate residues in multiple RACs. Comparable recoveries and superior precision were achieved with this new method as compared with a validated 10 g scale method.</jats:p

Connecting Students with Patients and Survivors to Enhance Cancer Research Training

AbstractThe professional training of cancer researchers in the basic sciences rarely involves interactions with patients. To provide nascent cancer scientists with an appreciation for and experience in interacting with the people most vested in their work, we created a program at Cornell University in which cancer researchers in training engage with the local patient community. Through this program, trainees gain a broader understanding of cancer, beyond the fundamental biology, and learn to effectively communicate scientific information to the public. We find that trainees and community members both benefit from interacting with one another and learning together about cancer using a common language.</jats:p