bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reorientation dynamics in liquid alcohols from Raman spectroscopy
Authors: Lin Ke , Hu Naiyin , Zhou Xiaoguo , Liu Shilin , Luo Yi 
Published: May 2011

AbstractPolarized Raman spectroscopy has been employed to study the reorientational, or more specifically the translational relaxation dynamics, of alcohol molecules in pure liquids and aqueous solutions. It is found from the spectral width measurements that alcohol molecules in pure liquids have typically translational relaxation times on the order of picoseconds, following the order methanol < ethanol < i‐propanol < n‐propanol. Temperature‐dependent measurements show that hydrogen‐bonding (HB) and hydrophobic interactions control the translational motion. The hydrophobic interaction reduces the relaxation time more apparently in view of the CH3 group than the skeleton motion. For alcohol–water mixtures, the increase of water concentration generally slows down the relaxation process in a non‐monotonic behavior. However, the trend stops at a certain point and the motion of alcohol molecules becomes faster when the alcohol concentration further drops. Different mechanisms have been proposed to interpret these observations, which might be helpful to gain deeper insight into the HB networks of alcohols with water. Our study strongly illustrates that Raman spectroscopy can be applied to the study of fast translational motion of molecules in HB systems. Copyright © 2011 John Wiley & Sons, Ltd.
Simultaneous acquisition of all four forms of circular polarization Raman optical activity: results for α‐pinene and lysozyme
Authors: Li Honggang , Nafie Laurence A. 
Published: May 2011

AbstractA new circularly polarized (CP) Raman spectrometer is described that demonstrates simultaneous acquisition of all four forms of circular polarization Raman optical activity (ROA). The instrument is a design extension of a commercially available back scattering circular polarization (SCP) ROA spectrometer. Circular polarization of the incident beam is introduced with a quarter‐wave plate, and a half‐wave plate alternately positioned in and out of the beam controls the modulation between right circular polarization (RCP) or left circular polarization (LCP) states. Combining this modulation with the simultaneous detection of RCP and LCP scattered Raman radiation allows the measurement of incident circular polarization (ICP), SCP, in‐phase dual circular polarization(DCPI) and out‐of‐phase DCPII‐ROA. In addition, three different forms of backscattered Raman spectra, namely unpolarized, highly polarized, and depolarized Raman spectra, as well as a degree of circularity spectrum are obtained. The performance of the new all‐CP ROA spectrometer is evaluated with neat α‐pinene and aqueous hen lysozyme solution. Copyright © 2011 John Wiley & Sons, Ltd.
A Model for Red Blood Cells in Simulations of Large‐scale Blood Flows
Authors: Melchionna Simone 
Published: May 2011

AbstractRed blood cells (RBCs) are an essential component of blood. A method to include the particulate nature of blood is introduced here with the goal of studying circulation in large‐scale realistic vessels. The method uses a combination of the Lattice Boltzmann method (LBM) to account for the plasma motion, and a modified molecular dynamics scheme for the cellular motion. Numerical results illustrate the quality of the model in reproducing known rheological properties of blood as much as revealing the effect of RBC structuring on the wall shear stress, with consequences on the development of cardiovascular diseases.magnified image
Three Routes to the Friction Matrix and Their Application to the Coarse‐Graining of Atomic Lattices
Authors: Kauzlarić David , Español Pep , Greiner Andreas , Succi Sauro 
Published: May 2011

AbstractThe calculation of the friction matrix in the coarse‐grained (CG) description of an atomistic system is a crucial issue, in order to properly account for the dissipative effects inherent to any reduced representation of the atomistic dynamics. Within the Mori‐Zwanzig projection operator approach to CG, there are several possibilities for the definition of the friction matrix, depending on the projector that is being used. In this paper, the connection of two of these projectors (Mori's and Zwanzig's) is discussed and the corresponding merits and limitations are analysed. Moreover, three different ways of computing the friction matrix in the Mori's framework are presented, along with a discussion of their mutual connections. By the example of CG centre of mass blob variables in the graphene lattice, it is shown that, even though the three approaches are equivalent from a theoretical viewpoint, they may differ considerably in terms of practical implementation for computer simulation purposes. In the given example, which is representative for atomic lattices, it turns out that a linear regression of the velocity–velocity correlation function, inspired by the Einstein–Helfand approach, is the least error‐prone against disturbances from optical modes. magnified image
Effects of medium and pore‐fluid compressibility on chemical‐dissolution front instability in fluid‐saturated porous media
Authors: Zhao Chongbin , Hobbs Bruce E. , Ord Alison 
Published: May 2011

SUMMARYTheoretical analysis and computational simulations have been carried out to investigate how medium and pore‐fluid compressibility affects the chemical‐dissolution front propagation, which is associated with a fully‐coupled nonlinear problem between porosity, pore‐fluid pressure, pore‐fluid density and reactive chemical‐species transport within a deformable and fluid‐saturated porous medium. When the fully‐coupled nonlinear system is in a subcritical state, some analytical solutions have been derived for a special case, in which the ratio of the equilibrium concentration to the solid molar density of the chemical species is approaching zero. To investigate the effect of either medium compressibility or pore‐fluid compressibility on the evolutions of chemical dissolution fronts in supercritical chemical dissolution systems, numerical algorithms and procedures have been also proposed. The related theoretical and numerical results have demonstrated that: (i) not only can pore‐fluid compressibility affect the propagating speeds of chemical dissolution fronts in both subcritical and supercritical systems, but also it can affect the growth and amplitudes of irregular chemical dissolution fronts in supercritical systems; (ii) medium compressibility may have a little influence on the propagating speeds of chemical dissolution fronts, but it can have significant effects on the growth and amplitudes of irregular chemical dissolution fronts in supercritical systems; and (iii) both medium and pore‐fluid compressibility may stabilize irregular chemical‐dissolution‐fronts in supercritical chemical dissolution systems. Copyright © 2011 John Wiley & Sons, Ltd.
The human urothelium consists of multiple clonal units, each maintained by a stem cell
Authors: Gaisa Nadine T , Graham Trevor A , McDonald Stuart AC , Cañadillas‐Lopez Sagrario , Poulsom Richard , Heidenreich Axel , Jakse Gerhard , Tadrous Paul J , Knuechel Ruth , Wright Nicholas A 
Published: May 2011

AbstractLittle is known about the clonal architecture of human urothelium. It is likely that urothelial stem cells reside within the basal epithelial layer, yet lineage tracing from a single stem cell as a means to show the presence of a urothelial stem cell has never been performed. Here, we identify clonally related cell areas within human bladder mucosa in order to visualize epithelial fields maintained by a single founder/stem cell. Sixteen frozen cystectomy specimens were serially sectioned. Patches of cells deficient for the mitochondrially encoded enzyme cytochrome c oxidase (CCO) were identified using dual‐colour enzyme histochemistry. To show that these patches represent clonal proliferations, small CCO‐proficient and ‐deficient areas were individually laser‐capture microdissected and the entire mitochondrial genome (mtDNA) in each area was PCR amplified and sequenced to identify mtDNA mutations. Immunohistochemistry was performed for the different cell layers of the urothelium and adjacent mesenchyme. CCO‐deficient patches could be observed in normal urothelium of all cystectomy specimens. The two‐dimensional length of these negative patches varied from 2–3 cells (about 30 µm) to 4.7 mm. Each cell area within a CCO‐deficient patch contained an identical somatic mtDNA mutation, indicating that the patch was a clonal unit. Patches contained all the mature cell differentiation stages present in the urothelium, suggesting the presence of a stem cell. Our results demonstrate that the normal mucosa of human bladder contains stem cell‐derived clonal units that actively replenish the urothelium during ageing. The size of the clonal unit attributable to each stem cell was broadly distributed, suggesting replacement of one stem cell clone by another. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Haem oxygenase‐1 dictates intrauterine fetal survival in mice via carbon monoxide
Authors: Zenclussen Maria Laura , Casalis Pablo Ariel , El‐Mousleh Tarek , Rebelo Sofia , Langwisch Stefanie , Linzke Nadja , Volk Hans‐Dieter , Fest Stefan , Soares Miguel Parreira , Zenclussen Ana Claudia 
Published: May 2011

AbstractPregnancy establishment implies the existence of a highly vascularized and transient organ, the placenta, which ensures oxygen supply to the fetus via haemoproteins. Haem metabolism, including its catabolism by haem oxygenase‐1 (HO‐1), should be of importance in maintaining the homeostasis of haemoproteins and controlling the deleterious effects associated with haem release from maternal or fetal haemoglobins, thus ensuring placental function and fetal development. We demonstrate that HO‐1 expression is essential to promote placental function and fetal development, thus determining the success of pregnancy. Hmox1 deletion in mice has pathological consequences for pregnancy, namely suboptimal placentation followed by intrauterine fetal growth restriction (IUGR) and fetal lethality. These pathological effects can be mimicked by administration of exogenous haem in wild‐type mice. Fetal and maternal HO‐1 is required to prevent post‐implantation fetal loss through a mechanism that acts independently of maternal adaptive immunity and hormones. The protective HO‐1 effects on placentation and fetal growth can be mimicked by the exogenous administration of carbon monoxide (CO), a product of haem catabolism by HO‐1 that restores placentation and fetal growth. In a clinical relevant model of IUGR, CO reduces the levels of free haem in circulation and prevents fetal death. We unravel a novel physiological role for HO‐1/CO in sustaining pregnancy which aids in understanding the biology of pregnancy and reveals a promising therapeutic application in the treatment of pregnancy pathologies. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Neutrophils promote motility of cancer cells via a hyaluronan‐mediated TLR4/PI3K activation loop
Authors: Wu Yan , Zhao Qiyi , Peng Chen , Sun Lin , Li Xue‐Feng , Kuang Dong‐Ming 
Published: May 2011

AbstractInflammation is a component of tumour progression mechanisms. Neutrophils are a common inflammatory infiltrate in many tumours, but their regulation and functions in neoplasia are not understood. We recently demonstrated that pro‐inflammatory IL‐17‐producing cells recruited blood neutrophils into the peritumoural stroma of hepatocellular carcinoma by epithelium‐derived CXC chemokines. Here we show that a substantial population of neutrophils accumulates in the peritumoural stroma of hepatocellular, cervical, colorectal, and gastric carcinomas, and that this correlates with metastases in hepatocellular and gastric carcinomas. Exposure of neutrophils to culture supernatants from several types of solid tumour cells (TSN) resulted in sustained survival and pro‐tumourigenic effects of cells. Kinetic experiments reveal that, shortly after exposure to TSN, neutrophils began to provoke activation and then produced significant inflammatory cytokines and expressed more anti‐apoptotic Mcl‐1 but less pro‐apoptotic Bax. These long‐lived neutrophils effectively enhanced the cancer cell motility via a contact‐dependent mechanism; this effect, together with early activation and subsequent longevity of TSN‐exposed neutrophils, could be reversed by blocking the activation of PI3K/Akt signalling in neutrophils. Moreover, we found that hyaluronan (HA) fragments constitute a common factor produced by various tumours that mimics the effect of TSN to induce long‐lived neutrophils and subsequent malignant cell migration. The effects of TSN were inhibited by function blocking interactions between HA and its receptor TLR4 on neutrophils, suggesting that this is a key signalling pathway involved. These results indicate that HA derived from malignant cells educates neutrophils to adopt an activated phenotype, and in that way stimulates the metastasis of malignant cells, which represents a positive regulatory loop between tumours and their stroma during neoplastic progression. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Simultaneously assessing intended and unintended treatment effects of multiple treatment options: a pragmatic “matrix design”
Authors: Rassen Jeremy A. , Solomon Daniel H. , Glynn Robert J. , Schneeweiss Sebastian 
Published: May 2011

ABSTRACTPurposeA key aspect of comparative effectiveness research is the assessment of competing treatment options and multiple outcomes rather than a single treatment option and a single benefit or harm. In this commentary, we describe a methodological framework that supports the simultaneous examination of a “matrix” of treatments and outcomes in non‐randomized data.MethodsWe outline the methodological challenges to a matrix‐type study (matrix design). We consider propensity score matching with multiple treatment groups, statistical analysis, and choice of association measure when evaluating multiple outcomes. We also discuss multiple testing, use of high‐dimensional propensity scores for covariate balancing in light of multiple outcomes, and suitability of available software.ConclusionThe matrix design study methods facilitate examination of the comparative benefits and harms of competing treatment choices, and also provides the input required for calculating the numbers needed to treat and for a broader benefit/harm assessment that weighs endpoints of varying severity. Copyright © 2011 John Wiley & Sons, Ltd.
Analytical treatment of Trivich–Flinn and Shockley–Queisser photovoltaic efficiency limits using polylogarithms
Authors: Green Martin A. 
Published: May 2011

ABSTRACTSolutions for the Trivich–Flinn and Shockley–Queisser formulations of the limiting efficiency of photovoltaic conversion are derived in terms of polylogarithms. Earlier Trivich–Flinn limits are shown to be zero temperature limits of the Shockley–Queisser approach. The limiting efficiency of an infinite stack of tandem cells was also investigated with an analytically based solution derived, the limit on photovoltaic conversion for a time‐symmetric system, which is compared to the time‐asymmetric limit. Copyright © 2011 John Wiley & Sons, Ltd.
Identification of β2‐microglobulin as a urinary biomarker for chronic allograft nephropathy using proteomic methods
Authors: Johnston Olwyn , Cassidy Hilary , O'Connell Séin , O'Riordan Aisling , Gallagher William , Maguire Patricia B. , Wynne Kieran , Cagney Gerard , Ryan Michael P. , Conlon Peter J. , McMorrow Tara 
Published: May 2011

AbstractPurpose: Chronic allograft nephropathy (CAN) remains the leading cause of renal graft loss after the first year following renal transplantation. This study aimed to identify novel urinary proteomic profiles, which could distinguish and predict CAN in susceptible individuals.Experimental design: The study included 34 renal transplant patients with histologically proven CAN and 36 patients with normal renal transplant function. High‐throughput proteomic profiles were generated from urine samples with three different ProteinChip arrays by surface‐enhanced laser‐desorption/ionization time‐of‐flight mass spectrometry (SELDI‐TOF‐MS). Following SELDI, a biomarker pattern software analysis was performed which led to the identification of a novel biomarker pattern that could distinguish patients with CAN from those with normal renal function.Results: An 11.7 kDa protein identified as β2 microglobulin was the primary protein of this biomarker pattern, distinguishing CAN from control patients (receiver operator characteristic [ROC]=0.996). SELDI‐TOF‐MS comparison of purified β2 microglobulin protein and CAN urine demonstrated identical 11.7 kDa protein peaks. Significantly, higher concentrations of 2 microglobulin were found in the urine of patients with CAN compared with the urine of normal renal function transplant recipients (p<0.001).Conclusions and clinical relevance: Although further validation in a larger more diverse patient population is required to determine if this β2 microglobulin protein biomarker will provide a potential means of diagnosing CAN by noninvasive methods in a clinical setting, this study clearly shows a capability to stratify control and disease patients.
Multi‐Objective Optimization of Interior Ballistic Performance Using NSGA‐II
Authors: Li Kejing , Zhang Xiaobing 
Published: May 2011

AbstractThis paper investigates an interior ballistic design with equal and unequal web thicknesses of seven‐perforation propellant grains using optimization methods. In order to reveal the influence of the web thickness of the propellant grains on the overall interior ballistic performance, burning seven‐perforation propellant grains with both equal and unequal web thickness is modeled. A currently popular evolution algorithm (EA) is used to compare two charge shapes, and to seek which one could achieve the optimal ballistic performance. Complete optimization of the interior ballistic performance is a complex process in view of the conflicting objectives to be achieved and a solution to such problems is sought by converting them into a single composite objective and using many tedious measurements. In this paper, a true multi‐objective optimization of the interior ballistic charging design is carried out by considering three objectives simultaneously. The non‐dominated sorting genetic algorithm version II (NSGA‐II) is used to solve this multi‐objective optimization problem (MOP). In order to check its implementation, both the conventional optimization algorithm‐hill climbing method (HCM) and NSGA‐II are used to solve the same single objective problem. The NSGA‐II used to capture the full Pareto‐optimal front is capable of identifying the trade‐off among the conflicting objectives thereby providing alternative useful designs for a designer. Furthermore, for seven‐perforation propellant grains, the results of using equal web thickness are compared with those of unequal web thickness, and it is shown that the two charge shapes produce no distinct difference in the interior ballistic performance.
On the equivalence of string vacua
Authors: Faraggi A.E. 
Published: May 2011

AbstractThe heterotic‐string models in the free fermionic formulation are among the most realistic string vacua constructed to date, which motivates their detailed exploration. Classification of free fermionic heterotic‐string vacua revealed a duality under exchange of spinor and vector representations of the SO(10) GUT symmetry. The spinor–vector duality was subsequently demonstrated in a Z2 × Z2 × Z2 orbifold, in which the map is realised as exchange of discrete torsions. Analysis of the orbifold partition function shows that the duality map preserves the number of massless twisted states. While the dual vacua are distinct from the point of view of the low energy field theory it is suggested that they are equivalent from the string point of view and may be connected by continuous and discrete transformations.
Warped 5D standard model consistent with EWPT
Authors: Cabrer J. , v. Gersdorff G. , Quirós M. 
Published: May 2011

AbstractFor a 5D Standard Model propagating in an AdS background with an IR localized Higgs, compatibility of bulk KK gauge modes with EWPT yields a phenomenologically unappealing KK spectrum (mKK< 12.5 TeV) and leads to a “little hierarchy problem”. For a bulk Higgs the solution to the hierarchy problem reduces the previous bound only by ∼ $^{1 \over 2}$. As a way out, models with an enhanced bulk gauge symmetry SU(2)R × U(1)B‐L were proposed. In this note we describe a much simpler (5D Standard) Model, where introduction of an enlarged gauge symmetry is no longer required. It is based on a warped gravitational background which departs from AdS at the IR brane and a bulk propagating Higgs. The model is consistent with EWPT for a range of KK masses within the LHC reach.
Towards classification of SO(10) heterotic string vacua
Authors: Rizos J. 
Published: May 2011

AbstractWe report some recent progress towards classification of phenomenologically appealing heterotic string models in the Free Fermionic Formulation. We focus on a class of Z2× Z2 models with SO(10) space‐time gauge symmetry and study their main phenomenological aspects. We further consider reducing the gauge symmetry to the Pati–Salam gauge group SU(4) × SU(2) L × SU(2)R and impose a series of phenomenological constraints including the existence of gauge symmetry breaking Higgs particles and the elimination of exotic fractionally charged states.
Loop QCD
Authors: Papadopoulos C.G. 
Published: May 2011

AbstractIn this lecture I briefly review the extraordinary developments, over the last few years, of QCD calculations beyond the leading approximation. The new reduction techniques have been paved the way for many calculations, that most people believed impossible before. In particular the OPP method is discussed along with the description of the HELAC‐NLO system. A couple of its applications are briefly presented.
Flavour violating up‐squark decays at LHC
Authors: Eberl H. , Bartl A. , Herrmann B. , Hidaka K. , Majerotto W. , Porod W. 
Published: May 2011

AbstractWe study the effect of squark generation mixing on squark production and decays at the LHC in the Minimal Supersymmetric Standard Model (MSSM). We show that the effect can be very large despite the very strong constraints on quark flavour violation (QFV) from experimental data on B mesons. We find that the two lightest up‐type squarks

can have large branching ratios for the decays into

and

at the same time, leading to QFV signals ‘

+ missing‐ET + X′ with a significant rate. The observation of this remarkable signature would provide a powerful test of supersymmetric QFV at LHC. This could have a significant impact on the search for squarks and the determination of the underlying MSSM parameters.
Recent developments in non‐Abelian T‐duality in string theory
Authors: Sfetsos K. 
Published: May 2011

AbstractSynopsis: We briefly review the essential points of our recent work in non‐Abelian T‐duality. In particular, we show how non‐Abelian T‐duals can effectively describe infinitely high spin sectors of a parent theory and how to implement the transformation in the presence of non‐vanishing Ramond fields in type‐II supergravity.