bluuebunny/crossref_metadata_2025_split huggingface dataset:
Core‐corona model analysis of the low energy beam scan at RHIC
Authors: Gemard M. , Aichelin J. 
Published: January 2015

AbstractThe centrality dependence of spectra of identified particles in collisions between ultrarelativistic heavy ions with a center of mass energy (√s) of 39 and 11.5 AGeV is analyzed in the core‐corona model. We show that at these energies the spectra can be well understood assuming that they are composed of two components whose relative fraction depends on the centrality of the interaction: The core component which describes an equilibrated quark gluon plasma and the corona component which is caused by nucleons close to the surface of the interaction zone which scatter only once and which is identical to that observed in proton‐proton collisions. The success of this approach at 39 and 11.5 AGeV shows that the physics does not change between this energy and √s = 200 AGeV for which this model has been developed (Aichelin 2008). This presents circumstantial evidence that a quark gluon plasma is also created at center of mass energies as low as 11.5 AGeV. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of strong magnetic fields on the population of hyperon stars
Authors: Gomes R. O. , Dexheimer V. , Vasconcellos C. A. Z. 
Published: January 2015

AbstractIn this contribution we study the effects of strong magnetic fields on the particle population of neutron stars with hyperon degrees of freedom in their composition. The star matter is described by a multi‐component model with parameterized baryon‐meson interaction couplings. We study the magnetic effects on the equation of state (EoS) due to the Landau quantization, assuming a density dependent static magnetic field that reaches about 1019 G in the center of the star. The Tolman‐Oppenheimer‐Volkoff equations are solved in order to understand the dependence of the mass‐radius relation and hyperon population on the magnetic field intensity assuming different interaction coupling schemes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rotation and cooling of neutron stars
Authors: Negreiros R. , Schramm S. , Weber F. 
Published: January 2015

AbstractDriven by the loss of energy, isolated rotating neutron stars (pulsars) are gradually slowing down to lower frequencies, which increases the tremendous compression of the matter inside of them. This increase in compression changes both the global properties of rotating neutron stars as well as their hadronic core compositions. Both effects may register themselves observationally in the thermal evolution of such stars, as demonstrated in this work. The rotation‐driven particle process which we consider here is the direct Urca (DU) process, which is known to become operative in neutron stars if the number of protons in the stellar core exceeds a critical limit of around 11 % to 15 %. We find that neutron stars spinning down from moderately high rotation rates of a few hundred Hertz may be creating just the right conditions where the DU process becomes operative, leading to an observable effect (enhanced cooling) in the temperature evolution of such neutron stars. We will also study the thermal evolution of neutron stars whose spherical symmetry has been broken due to non‐zero rotation. For this we will derive the energy balance and transport equations, taking into account the metric of a rotating fluid distribution and solve these equations numerically. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The many lives of magnetized neutron stars
Authors: Perna R. , Pons J. A. , Viganò D. , Rea N. 
Published: January 2015

AbstractThe magnetic field strength at birth is arguably one of the most important properties to determine the evolutionary path of a neutron star. Objects with very high fields, collectively known as magnetars, are characterized by high X‐ray quiescent luminosities, occurrence of outbursts, and, for some of them, sporadic giant flares. While the magnetic field strength is believed to drive their collective behaviour, however, the diversity of their properties, and, especially, the observation of magnetar‐like bursts from “low‐field” pulsars, has been a theoretical puzzle. In this review, we discuss results of long‐term simulations following the coupled evolution of the X‐ray luminosity and the timing properties for a large, homogeneous sample of X‐ray emitting isolated neutron stars, accounting for a range of initial magnetic field strengths, envelope compositions, and neutron star masses. In addition, by following the evolution of magnetic stresses within the neutron star crust, we can also relate the observed magnetar phenomenology to the physical properties of neutron stars, and in particular to their age and magnetic field strength and topology. The dichotomy of “high‐B” field pulsars versus magnetars is naturally explained, and occasional outbursts from old, low B‐field neutron stars are predicted. We conclude by speculating on the fate of old magnetars, and by presenting observational diagnostics of the neutron star crustal field topology. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Loop Quantum Gravity
Authors: Piguet O. 
Published: January 2015

AbstractIn this talk, I give a short general introduction to Loop Quantum Gravity (LQG), beginning with some motivations for quantizing General Relativity, listing various attempts and then focusing on the case of LQG. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective field theory for neutron stars with strong Σ–‐hyperon repulsion
Authors: Razeira M. , Mesquita A. , Vasconcellos C.A.Z. , Ruffini R. , Rueda J.A. , Gomes R.O. 
Published: January 2015

AbstractWe investigate the role of many‐body correlations in the maximum mass of neutron stars using the effective relativistic QHD‐model with parameterized couplings which represents an extended compilation of other effective models found in the literature. Our model exhausts the whole fundamental baryon octet (n, p, Σ–, Σ0, Σ+, Λ, Ξ–, Ξ0) and simulates corrections to the minimal Yukawa couplings by considering many‐body nonlinear self‐couplings and meson‐meson interaction terms involving scalar‐isoscalar (σ, σ*), vector‐isoscalar (ω, ϕ), vector‐isovector (ρ) and scalar‐isovector (δ). Following recent experimental results, we consider in our calculations the extreme case where the Σ– experiences such a strong repulsion that it does not appear at all in nuclear matter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Wind braking of magnetars: To understand magnetars' multiwave radiation properties
Authors: Tong H. , Xu R. X. 
Published: January 2015

AbstractMagnetars are proposed to be peculiar neutron stars powered by their super‐strong magnetic field. Observationally, anomalous X‐ray pulsars and soft gamma‐ray repeaters are believed to be magnetar candidates. While more and more multiwave observations of magnetars are available, we see unfortunately an accumulation of failed predictions of the traditional magnetar model. These challenges urge a reconsidering of the magnetar phenomenon. Wind braking of magnetars is one of the alternative modelings. The release of magnetic energy may generate a particle outflow (i.e., particle wind) which results in both an anomalous X‐ray luminosity (LX) and a significantly high spindown rate (Ṗ). In this wind braking scenario, only a strong multipole field is necessary for a magnetar (a strong dipole field is no longer needed). Wind braking of magnetars may help us to understand their multiwave radiation properties, including (1) non‐detection of magnetars in the Fermi ‐LAT observations, (2) timing behaviors of low magnetic field magnetars, (3) nature of anti‐glitches, (4) criterion for magnetar radio emission, etc. In the wind braking model of magnetars, timing events of magnetars should always be accompanied by radiative events. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rotational behaviors and magnetic field evolution of radio pulsars
Authors: Xie Y. , Zhang S.‐N. 
Published: January 2015

AbstractThe observed long‐term spin‐down evolution of isolated radio pulsars cannot be explained by the standard magnetic dipole radiation with a constant braking torque. However, how and why the torque varies remains still controversial, an outstanding problem in our understanding of neutron stars. We have constructed a phenomenological model of the evolution of surface magnetic fields of pulsars which contains a long‐term decay modulated by short‐term oscillations; a pulsar's spin is thus modified by its magnetic field evolution. The predictions of this model agree with the precisely measured spin evolution of several individual pulsars. The derived parameters suggest that the Hall drift and Hall waves in neutron star crusts are probably responsible for the long‐term change and short‐term quasi‐periodical oscillations, respectively. Many statistical properties of the timing noise of pulsars can well be reproduced with this model, including correlations and the distributions of the observed braking indices of the pulsars which span over a range of more than 100 millions. We have also presented a phenomenological model for the recovery processes of classical and slow glitches which can successfully model the observed slow and classical glitch events without biases. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Implication of ornithine acetyltransferase activity on l‐ornithine production in Corynebacterium glutamicum
Authors: Hao Ning , Mu Jingrui , Hu Nan , Xu Sheng , Shen Peng , Yan Ming , Li Yan , Xu Lin 
Published: January 2015

Abstractl‐Ornithine is an intermediate of the l‐arginine biosynthetic pathway in Corynebacterium glutamicum. The effect of ornithine acetyltransferase (OATase; ArgJ) on l‐ornithine production was investigated, and C. glutamicum 1006 was engineered to overproduce l‐ornithine as a major product by inactivating regulatory repressor argR gene and overexpressing argJ gene. A genome sequence analysis indicated that the argF gene encoding ornithine carbamoyltransferase in C. glutamicum 1006 was mutated, resulting in the accumulation of a certain amount of l‐ornithine (20.5 g/L). The assays using a crude extract of C. glutamicum 1006 indicated that the l‐ornithine concentration for 50% inhibition of OAT was 5 mM. To enhance l‐ornithine production, the argJ gene from C. glutamicum ATCC 13032 was overexpressed. In flask cultures, the resulting strain, C. glutamicum 1006∆argR‐argJ, produced 31.6 g/L l‐ornithine, which is 54.15% more than that produced by C. glutamicum 1006. The OAT activity of C. glutamicum 1006∆argR‐argJ was significantly greater than that of C. glutamicum 1006, and this study achieved the highest conversion ratio of sugar to acid (0.396 g/g) compared with those of previous reports. ArgJ strongly influences the production of l‐ornithine in C. glutamicum.
Effects of even and odd number fatty acids cofeeding on PHA production and composition in Pseudomonas putida Bet001 isolated from palm oil mill effluent
Authors: Mohd Razaif‐Mazinah Mohd Rafais , Mohamad Annuar Mohamad Suffian , Sharifuddin Yusrizam 
Published: January 2015

AbstractThe biosynthesis of medium‐chain‐length poly‐3‐hydroxyalkanoates by Pseudomonas putida Bet001 cultivated on mixed carbon sources was investigated. The mixed carbon sources consisted of heptanoic acid (HA) and oleic acid (OA). A relatively low PHA content at 1.2% (w/w) and 11.4% (w/w) was obtained when HA or OA was used as the sole carbon source. When these fatty acids were supplied as a mixture, PHA content increased threefold. Interestingly, the mixture‐derived PHA composed of both odd and even monomer units, namely. 3‐hydroxyheptanoate, 3‐hydroxyoctanoate, 3‐hydroxydecanoate, and 3‐hydroxydodecanoate and no unsaturated monomer was detected. It is hypothesized that the even‐numbered monomers were derived primarily from OA, whereas the odd‐numbered monomer was derived from HA. This also points out to an efficient and yet distinct fatty acids metabolism that fed the PHA biosynthesis machinery of this particular microorganism. PHA obtained was elastomeric because melting temperature (Tm) and crystallinity were absent. It showed good thermal stability with degradation temperature (Td) ranging from 275.96 to 283.05 °C.
Study on the mechanism of the interaction between acteoside and pepsin using spectroscopic techniques
Authors: Fang Yifeng , Xu Hong , Shen Liangliang , Huang Fengwen , Yibulayin Shadaiti , Huang Songyang , Tian Shengli , Hu Zhangli , He Zhendan , Li Fangrong , Li Yinong , Zhou Kai 
Published: January 2015

AbstractThe interaction of acteoside with pepsin has been investigated using fluorescence spectra, UV/vis absorption spectra, three‐dimensional (3D) fluorescence spectra and synchronous fluorescence spectra, along with a molecular docking method. The fluorescence experiments indicate that acteoside can quench the intrinsic fluorescence of pepsin through combined quenching at a low concentration of acteoside, and static quenching at high concentrations. Thermodynamic analysis suggests that hydrogen bonds and van der Waal's forces are the main forces between pepsin and acteoside. According to the theory of Förster's non‐radiation energy transfer, the binding distance between pepsin and acteoside was calculated to be 2.018 nm, which implies that energy transfer occurs between acteoside and pepsin. In addition, experimental results from UV/vis absorption spectra, 3D fluorescence spectra and synchronous fluorescence spectra imply that pepsin undergoes a conformation change when it interacts with acteoside. Copyright © 2015 John Wiley & Sons, Ltd.
Meta-analysis of complication rates for single-loop versus dual-loop (Roux-en-Y) with isolated pancreaticojejunostomy reconstruction after pancreaticoduodenectomy
Authors: Klaiber U , Probst P , Knebel P , Contin P , Diener M K , Büchler M W , Hackert T 
Published: January 2015

Abstract

Background
Postoperative pancreatic fistula is one of the most important and potentially severe complications after partial pancreaticoduodenectomy. In this context, the reduction of postoperative pancreatic fistula by means of a dual-loop (Roux-en-Y) reconstruction with isolation of the pancreaticojejunostomy from biliary drainage has been evaluated in several studies. This systematic review and meta-analysis summarizes evidence of effectiveness and safety of the isolation of the pancreaticojejunostomy compared with conventional single-loop reconstruction.

Methods
Randomized clinical trials (RCTs) and controlled clinical trials (CCTs) comparing outcomes of dual-loop reconstruction with isolated pancreaticojejunostomy and single-loop reconstruction were searched according to PRISMA guidelines. Random-effects meta-analyses were performed and the results presented as weighted risk ratios or mean differences with their corresponding 95 per cent c.i.

Results
Of 83 trials screened for eligibility, three RCTs and four CCTs including a total of 802 patients were finally included. Quantitative synthesis showed no significant statistical difference between the two procedures regarding postoperative pancreatic fistula, delayed gastric emptying, haemorrhage, intra-abdominal fluid collection or abscess, bile leakage, wound infection, pneumonia, overall morbidity, mortality, reinterventions, reoperations, perioperative blood loss and length of hospital stay. Duration of surgery was significantly longer in patients undergoing dual-loop reconstruction.

Conclusion
Dual-loop (Roux-en-Y) reconstruction with isolated pancreaticojejunostomy after partial pancreaticoduodenectomy is not superior to single-loop reconstruction regarding pancreatic fistula rate or other relevant outcomes. Additional superiority trials are therefore not warranted, although a high-quality trial may be justified to prove equivalence or non-inferiority.
Education mitigates age‐related decline in N‐Acetylaspartate levels
Authors: Erickson Kirk I. , Leckie Regina L. , Weinstein Andrea M. , Radchenkova Polina , Sutton Bradley P. , Prakash Ruchika Shaurya , Voss Michelle W. , Chaddock‐Heyman Laura , McAuley Edward , Kramer Arthur F. 
Published: January 2015

AbstractBackgroundGreater educational attainment is associated with better neurocognitive health in older adults and is thought to reflect a measure of cognitive reserve. In vivo neuroimaging tools have begun to identify the brain systems and networks potentially responsible for reserve.MethodsWe examined the relationship between education, a commonly used proxy for cognitive reserve, and N‐acetylaspartate (NAA) in neurologically healthy older adults (N = 135; mean age = 66 years). Using single voxel MR spectroscopy, we predicted that higher levels of education would moderate an age‐related decline in NAA in the frontal cortex.ResultsAfter controlling for the variance associated with cardiorespiratory fitness, sex, annual income, and creatine levels, there were no significant main effects of education (B = 0.016, P = 0.787) or age (B = −0.058, P = 0.204) on NAA levels. However, consistent with our predictions, there was a significant education X age interaction such that more years of education offset an age‐related decline in NAA (B = 0.025, P = 0.031). When examining working memory via the backwards digit span task, longer span length was associated with greater education (P < 0.01) and showed a trend with greater NAA concentrations (P < 0.06); however, there was no age X education interaction on digit span performance nor a significant moderated mediation effect between age, education, and NAA on digit span performance.ConclusionsTaken together, these results suggest that higher levels of education may attenuate an age‐related reduction in neuronal viability in the frontal cortex.
Enhancement and Induction of HIV‐1 Infection through an Assembled Peptide Derived from the CD4 Binding Site of gp120
Authors: Groß Andrea , Rödel Katja , Kneidl Barbara , Donhauser Norbert , Mössl Marek , Lump Edina , Münch Jan , Schmidt Barbara , Eichler Jutta 
Published: January 2015

AbstractContact between the human immunodeficiency virus (HIV‐1) and its target cell is initiated by the interaction of viral gp120 with cellular CD4. An assembled peptide (CD4bs‐M) that presents the CD4 binding site of gp120 was previously shown to inhibit the gp120–CD4 interaction. Here, we demonstrate that CD4bs‐M selectively enhances infection of cells with HIV‐1, whereas infection with herpes simplex virus remains largely unaffected. The effects of CD4bs‐M variants containing D‐amino acids, or prolines at selected positions, point to the importance of side chain orientation and spatial orientation of this fragment. Furthermore, CD4bs‐M was shown to assemble into amyloid‐like fibrils that capture HIV‐1 particles, which likely contributes to the infection‐enhancing effect. Beyond infection enhancement, CD4bs‐M enabled HIV‐1 infection of CD4‐negative cells, suggesting that binding of the peptide to gp120 facilitates interaction of gp120 with coreceptors, which might in turn enhance HIV‐1 entry.
How bifurcation angle impacts the fate of side branch after main vessel stenting: A retrospective analysis of 1,200 consecutive bifurcation lesions in a single center
Authors: Zhang Dong , Xu Bo , Yin Dong , Li Yiping , He Yuan , You Shijie , Qiao Shubin , Wu Yongjian , Yan Hongbing , Yang Yuejin , Gao Runlin , Dou Kefei 
Published: January 2015

ObjectivesWe aimed to investigate the effect of bifurcation angle (BA) on side branch (SB) occlusion after main vessel (MV) stenting. Background: BA is thought to impact the risk of SB occlusion in coronary bifurcation patients undergoing percutaneous coronary intervention (PCI).MethodsA total of 1,171 consecutive patients with 1,200 bifurcation lesions undergoing one stent or provisional two stent techniques were studied. The lesions were divided into low angle and high angle groups using the median BA (52°). Multivariate logistic regression analysis was performed to identify independent predictors of SB occlusion.ResultsSB occlusion occurred in 88 (7.33%) of 1,200 bifurcation lesions treated with the one stent technique or MV stenting first strategy. The rate of SB occlusion was significantly higher in the high angle group (63/600, 10.5%) than the low angle group (25/600, 4.2%) (P < 0.001). The rate of SB occlusion increased significantly across quartiles of BA as follows: from 3.63% in the first quartile of BA, to 4.71% in quartile II, to 8.14% in quartile III to 12.97% in quartile IV (P < 0.001). Multivariable analysis showed that high angle was an independent predictor of SB occlusion (odds ratio: 1.026, 95% confidence intervals: 1.014–1.037, P < 0.001). Plaque distribution at the same side of SB, MV Thrombolysis in Myocardial Infarction flow grade before stenting, pre‐procedural diameter stenosis of bifurcation core, diameter ratio between MV/SB and diameter stenosis of SB before MV stenting were also independent predictors of SB occlusion.ConclusionsHigh BA was an independent predictor of SB occlusion after MV stenting. The occlusion risk of SB with a high BA should not be ignored. © 2015 Wiley Periodicals, Inc.
PLATINUM China: A prospective, randomized investigation of the platinum chromium everolimus‐eluting stent in de novo coronary artery lesions
Authors: Gao Runlin , Han Yaling , Yang Yuejin , Zhang Jian , Hou Yuqing , Wang Haichang , Li Hui , Fang Quan , Yu Bo , Xu Bo , Allocco Dominic J. , Dawkins Keith D. 
Published: January 2015

ObjectivesThe PLATINUM China clinical trial evaluated the safety and effectiveness of the thin‐strut, everolimus‐eluting, platinum‐chromium PROMUS™ Element™ stent (PtCr‐EES) (Boston Scientific, Marlborough, MA) for the treatment of patients in China.BackgroundClinical outcomes from the PtCr‐EES have not been evaluated in patients from China, nor has it been directly compared with the second‐generation stainless steel paclitaxel‐eluting TAXUS Liberté stent (PES) in a randomized head‐to‐head trial.Methods In this prospective, multicenter, single‐blind, superiority trial, patients with a single de novo atherosclerotic coronary artery lesion were randomized 1:3 to receive either the PES or PtCr‐EES. The primary endpoint was in‐stent late loss at 9 months.ResultsAmong 127 PES and 373 PtCr‐EES patients (71.2% male; mean age 57.3 years), the primary endpoint of 9‐month in‐stent late loss was 0.40 ± 0.45mm for PES versus 0.11 ± 0.36 mm for PtCr‐EES (P < 0.001). In‐stent % diameter stenosis was 22.20±16.00% for PES versus 11.06±13.86% for PtCr‐EES (P<0.001) at 9 months. The 1‐year rate of death/MI was 1.6% (2/127) for PES versus 0% (0/371) for PtCr‐EES (P=0.06) and target vessel revascularization was 4.7% (6/127) for PES versus 2.7% (10/371) for PtCr‐EES (P=0.26). No stent thromboses occurred at12 months in either group.ConclusionsIn the largest prospective angiographic evaluation conducted to date with this stent, the PROMUS Element PtCr‐EES was superior to the TAXUS Liberté PES for the primary endpoint of late loss at 9 months, with low rates of clinical events at 1 year. Clinical follow‐up will continue to 2 years. © 2015 Wiley Periodicals, Inc.
Probing The Structure Evolution of Iron‐Based Fischer–Tropsch to Produce Olefins by Operando Raman Spectroscopy
Authors: Fu Donglong , Dai Weiwei , Xu Xinchao , Mao Wei , Su Junjie , Zhang Zhengpai , Shi Bianfang , Smith Julian , Li Ping , Xu Jing , Han Yi‐Fan 
Published: January 2015

AbstractBy using operando Raman spectroscopy (ORS), we investigated the panoramic structure evolution of an iron oxide (α‐Fe2O3) catalyst, which is used for the production of olefins via Fischer–Tropsch (FTO). During activation in different atmospheres and reaction at 260 °C and 3.0 MPa, α‐Fe2O3 was only partially transformed into γ‐Fe2O3 by H2 pretreatment; meanwhile, a transformation of α‐Fe2O3→γ‐Fe2O3→Fe3O4→Fe5C2 was observed in both CO and syngas (H2/CO). Combining with other techniques such as XRD, TEM, XPS and TPSR, we reveal that assembles of various iron oxides (γ‐Fe2O3, Fe3O4, Fe carbide, and their combinations) are responsible for FTO. Especially, the preliminary relationship of catalyst structure and performance relating to the production of olefins directly from syngas was established. Such a study is critical for further understanding of the FTO reaction and other catalytic reactions.