229 resultados para Klee, Nathan


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The feasibility of laser cooling AlH and AlF is investigated using ab initio quantum chemistry. All the electronic states corresponding to the ground and lowest two excited states of the Al atom are calculated using multi-reference configuration interaction (MRCI) and the large AV6Z basis set for AlH. The smaller AVQZ basis set is used to calculate the valence electronic states of AlF. Theoretical Franck-Condon factors are determined for the A(1)Pi -> X(1)Sigma(+) transitions in both radicals and found to agree with the highly diagonal factors found experimentally, suggesting computational chemistry is an effective method for screening suitable laser cooling candidates. AlH does not appear to have a transition quite as diagonal as that in SrF (which has been laser cooled) but the A(1)Pi -> X(1)Sigma(+) transition transition of AlF is a strong candidate for cooling with just a single laser, though the cooling frequency is deep in the UV. Furthermore, the a (3)Pi -> X(1)Sigma(+) transitions are also strongly diagonal and in AlF is a practical method for obtaining very low final temperatures around 3 mu K.

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Strategies to produce an ultracold sample of carbon atoms are explored and assessed with the help of quantum chemistry. After a brief discussion of the experimental difficulties using conventional methods, two strategies are investigated. The first attempts to exploit charge exchange reactions between ultracold metal atoms and sympathetically cooled C+ ions. Ab initio calculations including electron correlation have been conducted on the molecular ions [LiC]+ and [BeC]+ to determine whether alkali or alkaline earth metals are a suitable buffer gas for the formation of C atoms but strong spontaneous radiative charge exchange ensure they are not ideal. The second technique involves the stimulated production of ultracold C atoms from a gas of laser cooled carbides. Calculations on LiC suggest that the alkali carbides are not suitable but the CH radical is a possible laser cooling candidate thanks to very favourable Frank-Condon factors. A scheme based on a four pulse STIRAP excitation pathway to a Feshbach resonance is outlined for the production of atomic fragments with near zero centre of mass velocity.

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Under what conditions does successful police reform take place? Can democratic forms of policing exist within undemocratic state structures? What are the motives of donor and recipient nations, and can the norms of global civil society be cultivated in order to promote human rights, democratic governance, and fair and accountable policing? These questions are addressed in this volume, which presents a unique examination of Western-led police reform efforts by theoretically linking neoliberal globalization, police reform and development. The authors present seven country case studies based on this theoretical approach (Afghanistan, Brazil, Iraq, Northern Ireland, South Africa, Trinidad and Tobago, and Turkey) and assess the prospects for successful police reform in a global context.

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I argue for a certain conception of events according to which they are essentially extended and temporal entities (contra Leftow), and then go on to argue that God is necessarily the subject of such events (even before creation--a claim which is particularly controversial). Together these claims entail that God is necessarily temporal.

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Drawing upon original survey research this article seeks to identify the generative processes that influence perceptions of the police in the context of an inner-city neighbourhood in Northern Ireland that has been affected by increases in crime and disorder in the aftermath of the peace process. Conceptually we draw upon recent research from England and Wales that outlines confidence in the police in terms of instrumental and expressive dimensions. We apply this framework and consider whether it provides a useful template for understanding the post-conflict dynamics of police-community relations in our study area. Contrary to much received wisdom our analysis suggests that instrumental concerns about crime and illegal activity are a more influential predictor of attitudes to the police than expressive concerns with disorder and anti-social behaviour. Consequently our discussion points to the variance in local and national survey data and questions the degree to which the latter can usefully inform our understanding of trends and developments in discrete micro-spaces. Our conclusion outlines the potential policy implications for state policing practice in deprived urban spaces.

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Charge transfer is a subfemtosecond process in molecules that creates chemical and electronic structure changes. At the quantum level the process can be coherently controlled by ultrashort light pulses. We show how the charge transfer process can be manipulated using a combination of dynamic and static fields and predict how this can be observed experimentally by imaging with photoionization.

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Metal organic frameworks (MOFs) are highly porous materials that can store significant amounts of gas, including nitric oxide. The chemical composition and toxicology of many (but not all) of these materials makes them potentially suitable for medical applications. In this paper, we will describe how triggered release methods can be used to deliver biologically relevant amounts of NO and then show how Ni, Co and Cu-containing MOFs are biologically active materials with potential applications in several different areas (anti-thrombosis, dermatology and wound healing, anti-bacterial, vasodilation etc.). We will also discuss the pros and cons of MOFs, including their chemical and biological stability and the toxicology of MOFs in general. (C) 2009 Elsevier Inc. All rights reserved.

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Microalbuminuria is a common diagnosis in the clinical care of patients with type 1 diabetes mellitus. Long-term outcomes after the development of microalbuminuria are variable.

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Clinical treatment goals of type 1 diabetes mellitus (T1DM) have changed since the Diabetes Control and Complications Trial (DCCT) demonstrated reduced long-term complications with intensive diabetes therapy. There have been few longitudinal studies to describe the clinical course of T1DM in the age of intensive therapy. Our objective was to describe the current-day clinical course of T1DM.

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S-(2-Succinyl)cysteine (2SC) has been identified as a chemical modification in plasma proteins, in the non-mercaptalbumin fraction of human plasma albumin, in human skin collagen, and in rat skeletal muscle proteins and urine. 2SC increases in human skin collagen with age and is increased in muscle protein of diabetic vs. control rats. The concentration of 2SC in skin collagen and muscle protein correlated strongly with that of the advanced glycation/lipoxidation end-product (AGE/ALE), N(epsilon)-(carboxymethyl)lysine (CML). 2SC is formed by a Michael addition reaction of cysteine sulfhydryl groups with fumarate at physiological pH. Fumarate, but not succinate, inactivates the sulfhydryl enzyme, glyceraldehyde-3-phosphate dehydrogenase in vitro, in concert with formation of 2SC. 2SC is the first example of spontaneous chemical modification of protein by a metabolic intermediate in the Krebs cycle. These observations identify fumarate as an endogenous electrophile and suggest a role for fumarate in regulation of metabolism.

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Type 1 diabetes mellitus is associated with an increased risk of cardiovascular disease (CVD) that is not fully explained by conventional risk factors. The Diabetes Control and Complications Trial (DCCT) showed that intensive diabetes therapy reduced levels of LDL cholesterol and triglycerides but increased the risk of major weight gain, which might adversely affect CVD risk. The present study examined the effect of intensive therapy on levels of several markers of inflammation that have been linked to risk of CVD.

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It has been suggested that low-density lipoprotein (LDL) modified by glycation may be more susceptible to oxidation and thus, enhance its atherogenicity. Using affinity chromatography, LDL glycated in vivo (G-LDL) and relatively nonglycated. (N-LDL) subfractions can be isolated from the same individual. The extent of and susceptibility to oxidation of N-LDL compared with G-LDL was determined in 15 type 1 diabetic patients. Total LDL was isolated and separated by boronate affinity chromatography into relatively glycated (G-) and nonglycated (N-) subfractions. The extent of glycation, glycoxidation, and lipoxidation, lipid soluble antioxidant content, susceptibility to in vitro oxidation, and nuclear magnetic resonance (NMR)-determined particle size and subclass distribution were determined for each subfraction. Glycation, (fructose-lysine) was higher in G-LDL versus N-LDL, (0.28 +/- 0.08 v 0.13 +/- 0.04 mmol/mol lysine, P <.0001). However, levels of glycoxidation/lipoxidation products and of antioxidants were similar or lower in G-LDL compared with N-LDL and were inversely correlated with fructose-lysine (FL) concentrations in G-LDL, but positively correlated in N-LDL. In vitro LDL (CuCl2) oxidation demonstrated a longer lag time for oxidation of G-LDL than N-LDL (50 +/- 0.16 v 37 +/- 0.15 min, P <.01), but there was no difference in the rate or extent of lipid oxidation, nor in any aspect of protein oxidation. Mean LDL particle size and subclass distribution did not differ between G-LDL and N-LDL. Thus, G-LDL from well-controlled type 1 diabetic patients is not more modified by oxidation, more susceptible to oxidation, or smaller than relatively N-LDL, suggesting alternative factors may contribute to the atherogenicity of LDL from type 1 diabetic patients.

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Introduction: Whilst there are reports of viral myopathies affecting children and the immunocompromised, infective myositis is a relatively rare inflammatory myopathy in adults. The clinical spectrum can range from benign myalgias to more serious complications in certain risk groups. Case Presentation: We present two cases of myositis as a result of parvovirus B19 infection.
Conclusion: Viral myositis and parvovirus B19 associated myositis should be considered in adults presenting with significant myalgia.

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Toll-like receptors (TLRs) are crucial in the innate immune response to pathogens, in that they recognize and respond to pathogen associated molecular patterns, which leads to activation of intracellular signaling pathways and altered gene expression. Vaccinia virus (VV), the poxvirus used to vaccinate against smallpox, encodes proteins that antagonize important components of host antiviral defense. Here we show that the VV protein A52R blocks the activation of the transcription factor nuclear factor kappa B (NF-kappa B) by multiple TLRs, including TLR3, a recently identified receptor for viral RNA. A52R associates with both interleukin 1 receptor-associated kinase 2 (IRAK2) and tumor necrosis factor receptor-associated factor 6 (TRAF6), two key proteins important in TLR signal transduction. Further, A52R could disrupt signaling complexes containing these proteins. A virus deletion mutant lacking the A52R gene was attenuated compared with wild-type and revertant controls in a murine intranasal model of infection. This study reveals a novel mechanism used by VV to suppress the host immunity. We demonstrate viral disabling of TLRs, providing further evidence for an important role for this family of receptors in the antiviral response.

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This Letter describes the development and SAR of a novel series of GlyT1 inhibitors derived from a scaffold hopping approach, in lieu of an HTS campaign, which provided intellectual property position. Members within this new [3.3.0]​-​based series, e.g. I, displayed excellent GlyT1 potency, selectivity, free fraction, and modest CNS penetration. Moreover, enantioselective GlyT1 inhibition was obsd., within this novel series and a no. of other piperidine bioisosteric cores.