bluuebunny/crossref_metadata_2025_split huggingface dataset:
On‐resin conversion of Cys(Acm)‐containing peptides to their corresponding Cys(Scm) congeners
Authors: Mullen Daniel G. , Weigel Benjamin , Barany George , Distefano Mark D. 
Published: April 2010

AbstractThe Acm protecting group for the thiol functionality of cysteine is removed under conditions (Hg2+) that are orthogonal to the acidic milieu used for global deprotection in Fmoc‐based solid‐phase peptide synthesis. This use of a toxic heavy metal for deprotection has limited the usefulness of Acm in peptide synthesis. The Acm group may be converted to the Scm derivative that can then be used as a reactive intermediate for unsymmetrical disulfide formation. It may also be removed by mild reductive conditions to generate unprotected cysteine. Conversion of Cys(Acm)‐containing peptides to their corresponding Cys(Scm) derivatives in solution is often problematic because the sulfenyl chloride reagent used for this conversion may react with the sensitive amino acids tyrosine and tryptophan. In this protocol, we report a method for on‐resin Acm to Scm conversion that allows the preparation of Cys(Scm)‐containing peptides under conditions that do not modify other amino acids. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Photo‐EPR and magneto‐optical spectroscopy of iron centres in ZnO
Authors: Azamat D. V. , Debus J. , Yakovlev D. R. , Ivanov V. Yu. , Godlewski M. , Fanciulli M. , Bayer M. 
Published: April 2010

AbstractZnO has attracted increasing interest as promising material for optoelectronics and spintronics. Magnetic properties of ZnO can be controlled by doping with transition metal ions among which Fe3+ is one of the interesting candidates. We report on the properties of Fe3+ centres in hydrothermally and chemical vapour transport grown ZnO single crystals investigated by photo‐electron paramagnetic resonance (EPR) and optical spectroscopy. Detailed magneto‐optical studies of Zeeman components of spin‐forbidden electric dipole transitions 4T1(G) → 6A1(6S) of Fe3+ centre in ZnO reveal the trigonal symmetry of fine structure of lowest Γ8 (4T1) excited state. The studies were performed in external magnetic fields up to 10 T and in the temperature range from 2 to 30 K. The energy positions of the Zeeman components at 8 T were measured as a function of the direction of applied magnetic field in $(1\bar {2}10)$ and (0001) planes. The detailed check of the angular variation of Zeeman lines shows two magnetically non‐equivalent Fe3+ centres. These special features were accounted by contribution of higher rank Zeeman terms of dimension BJ3. The photo‐generated EPR spectra of trigonal Fe3+ centres were detected in hydrothermally grown ZnO single crystals in addition to three types of charge compensated iron centres presented in these samples in the dark conditions.
Ultra‐violet ZnSSe, ZnMgS epilayers and MQW structures grown by MOVPE on GaP substrates
Authors: Kuznetsov Petr , Yakushcheva Galina , Jitov Victor , Zakharov Leonid , Lusanov Valery , Kozlovsky Vladimir , Tiberi Michael 
Published: April 2010

AbstractThe latest results on MOVPE growth of thick ZnSSe, ZnMgS epitaxial layers and MQW structures on their base are presented. The structures were grown on GaP substrates with different missorientation from (100) plane using ZnEt2, (MeCp)2Mg, Et2S2 and Et2Se as precursors at 490‐530 °C. The growth conditions of epilayers and periodic structures on substrate tilted by 10° to (111)A plane with high luminescence properties and smooth surface at thickness more than 5 μm were found. Thick ZnMgS‐based structures, grown under constant flow of (MeCp)2Mg supplied into reactor, have not stable Mg content. Therefore, the correction of Mg supply during the growth of ZnSSe/ZnMgS MQW structures was carried out. Based on the grown MQW structure, electron beam pumped vertical‐cavity surface‐emitting lasers (eVCSEL) was fabricated. Lasing at 376 nm with 0.8 W output power was achieved at RT and accelerating voltage of 50 kV. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Point and nanoscale defects in Cd(S, Se, Te) crystals induced by plastic deformation
Authors: Babentsov V. , Boiko V. , Grill R. , Franc J. , Shepelskii G. A. 
Published: April 2010

AbstractThe effect of uniaxial plastic deformation, indentation, and scribing along the selected axes on the excitonic and deep level photoluminescence (PL) of CdS, CdSe, CdTe, and ternary CdSeTe compounds has been studied. Dislocations movement produces new near band‐gap narrow PL lines, and changes initial wide PL bands (the deep level emission), in particular, a relative intensity increase or appearing of the near midgap 0.8 eV, 1.1 and 1.45 eV bands in CdTe, and corresponding PL bands in other II‐VI compounds (CdS, CdSe, and CdSeTe) (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physical and chemical cross analyses of II‐VI semiconductor nanomaterials
Authors: Dalmasso S. , Arl D. , Fregnaux M. , Gaumet J.‐J. , Zhang Y. , Laurenti J.‐P. 
Published: April 2010

AbstractCdS quantum dots (QDs) are synthesized by the single source precursor thermal method. Compared with previous reports, a temperature ramp allows faster elaboration of smaller nanocrystals (NCs) with efficient room temperature (RT) visible emission. A cross‐disciplinary study between chemical analyses and physical techniques provides consistent data for these small NCs. Joint mass spectrometry, transmission electron microscopy and optical spectrometry techniques give a consistent picture about purity and stability of precursors, average size and size dispersion of the NCs, as well as their optical spectral response in correlation with their size via quantum confinement effects. RT photoluminescence spectroscopy reveals the great potential of such QDs and their tunable response wavelength in the visible spectrum. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electroluminescence from a n‐ZnO/p‐GaN hybrid LED
Authors: Behrends Arne , Bakin Andrey , Waag Andreas , Kwack Ho‐Sang , Dang Le Si 
Published: April 2010

AbstractIn this work we report on the fabrication and characterization of a n‐ZnO/p‐GaN heterojunction LED. The p‐GaN layer was fabricated using MOCVD on Al2O3 with Mg as the acceptor whereas the ZnO nanostructures were grown in a very simple vapor transport system without any additionally doping. Room temperature electroluminescence (EL) measurements show green deep band emission centered at 2.3 eV which is clearly visible with the naked eye when the structure is forward biased. Cathodoluminescence mapping was performed to explain the absence of the band edge emission in the EL spectrum. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ga doped ZnO thin films prepared by RF plasma assisted DC magnetron sputtering under reductive atmosphere without heating substrates
Authors: Hinoki Toshio , Yazawa Kenji , Kinoshita Kentaro , Ohmi Koutoku , Kishida Satoru 
Published: April 2010

AbstractGa doped ZnO (GZO) transparent conductive thin films have been prepared by RF plasma assisted DC magnetron sputtering under a reductive atmosphere without intentionally heating substrate. The resistivity of the GZO film facing the erosion area in the source target falls to about a 1/1000 value by providing the RF plasma, resulting in a uniform distribution of the sheet resistance. Currently obtained values of resistivity, Hall mobility, and carrier concentration are 1 x 10‐2 Ω‐cm, 4 cm2/Vs, and 3 x 1020 cm‐3, respectively. It has been also found that the crystallization of GZO films is also enhanced by the RF plasma. After the accelerated aging test (60 °C ‐ 95%RH) for 250 hrs, the sheet resistance maintains almost the same as the initial value for the GZO film prepared with RF plasma, though that increases by 15 times for the film prepared without RF plasma. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cr2+:CdS crystal as a new material for room‐temperature tunable mid‐infrared lasing
Authors: Akimov V. A. , Frolov M. P. , Korostelin Yu. V. , Kozlovsky V. I. , Landman A. I. , Mislavskii V. V. , Podmar'kov Yu. P. , Skasyrsky Ya. K. , Voronov A.A. 
Published: April 2010

AbstractBy using the seeded physical vapour transport (SPVT) method the CdS:Cr single crystals were grown. Doping concentration up to 5×1018 cm‐3 was achieved. The emission lifetime of the exited state, 5E, of Cr2+ in CdS host was measured to be 0.93 μs at room temperature and 7.3 μs at liquid nitrogen temperature. The measured values of peak absorption and emission cross sections were found to be 1.4×10‐18 and 1.1×10‐18 cm2 respectively. Tuning possibility and efficiency of pulsed Cr2+:CdS laser was described. CW laser operation with slope efficiency of 52% and output power up to 0.79 W was obtained (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improvement of chemical stability of aqueous solution grown ZnO nanorods by aminosilane modification
Authors: Ogata Ken‐ichi , Dobashi Hideaki , Koike Kazuto , Sasa Shigehiko , Inoue Masataka , Yano Mitsuaki 
Published: April 2010

AbstractAiming at stable biosensing operation, aqueous‐grown ZnO nanorods on sapphire substrates were examined their chemical stability against the immersion in HCl solution. Density and diameter of the ZnO nanorods were remained but their height was shortened when immersed with aminosilane modification while bare ZnO nanorods were completely disappeared after 5 min immersion, indicating that the aminosilane modification is useful to improve the chemical stability of ZnO nanolods even though the membrane by the silanezation process is not fully stable to HCl solution. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of variable crucible dropping rate on solid‐liquid interface in CdZnTe crystal growth
Authors: Zhou Chenying , Min Jiahua , Wang Changjun , Liang Xiaoyan , Teng Jianyong , Wang Linjun 
Published: April 2010

AbstractThe Cd0.9Zn0.1Te crystal growth with low pressure and vertical Bridgman method (LPVB) was numerically simulated and analysed by the simulation software of Comsol Multiphysics. In the process of crystal growth, the influence of variable crucible dropping rate on solid‐liquid interface was studied in this paper. The variability of crucible dropping rate was achieved by a specifical furnace temperature distribution function, while the selection and analysis of crucible dropping rate was obtained by the combination of orthogonal experimental design method and regression analysis method. In this paper, the value of relative crystal growth rate was defined, and the influence of variable crucible dropping rate on solid‐liquid interface was discussed by comparing these values. The simulation results showed that if the crucible dropping rate was 3.5 mm/h (ν1) in the first stage and 0.6 mm/h (ν2) in the second stage, and the distance (d) between the bottom of crucible and the position of melting point in tempreture field was 0.02 m at the time of dropping rate change, the solid‐liquid interface was appreciably convex after 211 hours' growth, and the relative crystal growth rate was 0.45%, which made the solid‐liquid interface smooth and kept the crystal grow up spontaneously.
ZnS:N and ZnS:N,Ag grown by molecular beam epitaxy
Authors: Ichino K. , Kotani A. , Tanaka H. , Kawai T. 
Published: April 2010

AbstractThe N‐doping conditions have been investigated in the growth of ZnS:N by molecular beam epitaxy using RF plasma of N2 gas. As a result, high growth temperatures are found to be suitable for the effective incorporation and the activation of N acceptors. The capacitance versus voltage data of the ZnS:N layers grown at around 350 °C exhibit p‐type behavior, while the undoped layers show an n‐type characteristic due to residual donors. ZnS:N,Ag epitaxial layers were also grown to investigate the effect of Ag‐co‐doping. It is shown that the p‐type behavior of the N‐doped layers is enhanced by the Ag‐co‐doping. This suggests the formation of Ag‐related complex centers compensating residual donors (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A magnetoelectric logic gate
Authors: Hu Jia‐Mian , Li Zheng , Lin Y. H. , Nan C. W. 
Published: April 2010

AbstractWe present a strain‐mediated magnetoelectric logic (ME‐logic) gate, with electric field directly used as the logical input/output. The basic building block of the ME‐logic device is a magnetic tunnel junction (MTJ) attached to a ferroelectric layer, in which the resistance of the MTJ unit can be modulated by an electric field applied to the ferroelectric layer. The ME‐logic device combines the advantage of conventional MTJ‐based logic devices, while avoiding their problems associated with generating high local magnetic fields required in the switching circuits. Two possible schemes of such ME‐logic devices are introduced, i.e., either operated as a logic NOR, NOT or NAND gate, or selected to realize the logical NOR, NOT or NAND function at run‐time.magnified imageSequence of a magnetoelectric logic gate.(© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of probe pollutants on morphological and mechanical measurements of muscle and collagen fibers using atomic force microscopy
Authors: Zhu Jie , Sabharwal Tanya , Guo Lianhong , Lee Jenny , Wang Lin , Wang Guodong 
Published: April 2010

AbstractBecause of the interaction between probes and samples, pollutants in buffer solution or in the air would easily bind to probes and make the probe polluted, which might influence the morphological and mechanical measurements with atomic force microscopy. The polluted probes might transfer the pollutants onto the samples and thus change the surface ultrastructure of samples, or collect the deviated feedback signals to make the phantasm images. The former process is irreversible even if a new probe is employed, and the latter one is a reversible process as long as changing the used/polluted probe. Effects of polluted probes on morphological and mechanical characteristics of insect flight muscle and rat tail tendon collagen I fibers had been discussed in this study, in which, we constructed a series of methods to avoid/reduce the collecting of phantasm images and deviated mechanical information, such as changing the scanning direction and scanning force, replacing the new probes, or cleaning the polluted probes. SCANNING 32:113–121, 2010. © 2010 Wiley Periodicals, Inc.
Constructing a GDP‐based index for use as a benchmark
Authors: Cohen Ruben D. 
Published: April 2010

AbstractThe gross domestic product (GDP) is a fundamental economic indicator that is frequently used as a benchmark for local equity indices. The widespread appeal of this association is understandable because an equity index, especially if broad, could, like the GDP, also manifest the state of the economy. At the same time, however, the validity of a direct relation between the two is debatable since the GDP is known to be characteristically different from the typical equity index, however broad.In this work, we review some of the key elements that separate the GDP from a typical broad equity index in order to explain why the two cannot be compared directly with each other. We then incorporate a readily available mapping technique to create a GDP‐based index that circumvents their inherent disparities and, thus, enable us to benchmark one against the other. Copyright © 2010 Wilmott Magazine Ltd.
A simple but promisingly more empirically consistent model for stock price and option pricing
Authors: Pang Huadong (Henry) 
Published: April 2010

AbstractIn this paper, we propose a simple stochastic model for stock price dynamics and option pricing, which not only has the same analyticity as log‐normal and Black‐Scholes model, but is also possibly more consistent with many phenomenons arising from empirical stock and option markets than many of the well‐known existing models. It is another way to model stock price and options under leptokurtic distribution that hopefully can add some new insight or give new ideas to improve stock and option valuation. Copyright © 2010 Wilmott Magazine Ltd.
Hematopoietic stem cell: self‐renewal versus differentiation
Authors: Seita Jun , Weissman Irving L. 
Published: April 2010

AbstractThe mammalian blood system, containing more than 10 distinct mature cell types, stands on one specific cell type, hematopoietic stem cell (HSC). Within the system, only HSCs possess the ability of both multipotency and self‐renewal. Multipotency is the ability to differentiate into all functional blood cells. Self‐renewal is the ability to give rise to HSC itself without differentiation. Since mature blood cells (MBCs) are predominantly short‐lived, HSCs continuously provide more differentiated progenitors while properly maintaining the HSC pool size throughout life by precisely balancing self‐renewal and differentiation. Thus, understanding the mechanisms of self‐renewal and differentiation of HSC has been a central issue. In this review, we focus on the hierarchical structure of the hematopoietic system, the current understanding of microenvironment and molecular cues regulating self‐renewal and differentiation of adult HSCs, and the currently emerging systems approaches to understand HSC biology. Copyright © 2010 John Wiley & Sons, Inc.This article is categorized under:

Developmental Biology > Stem Cell Biology and Regeneration
Quality at the Point of Service: Profiles of Practice in After‐School Settings
Authors: Smith Charles , Peck Stephen C. , Denault Anne-Sophie , Blazevski Juliane , Akiva Tom 
Published: April 2010

AbstractA unique observational data set was used to explore quality at the point of service in after‐school programs. Staff practices in after‐school settings were represented on a series of unidimensional scales closely indexed to staff behavior. In order to account for heterogeneity of staff performances, pattern‐centered methods were used to construct profiles of common staff practices. Results revealed six pedagogy profiles that were classified in terms of three broad types of performances delivered by after‐school staff: (1) positive youth development, (2) staff‐centered, and (3) low‐quality. Staff membership in these profiles was not related to youth‐staff ratio. However, results revealed significant differences between the profiles on the content of the offering and the age of youth in the setting.
Condition status and parasite infection of Neogobius kessleri and N. melanostomus (Gobiidae) in their native and non‐native area of distribution of the Danube River
Authors: Ondračková Markéta , Francová Kateřina , Dávidová Martina , Polačik Matej , Jurajda Pavel 
Published: April 2010

AbstractThe success of introduced species is often facilitated by escape from the effects of natural predators and parasites. Introduced species can profit from this favourable situation, attaining higher population densities and greater individual sizes in novel areas. In this study, somatic condition and parasite infection were compared between native and non‐native populations of Neogobius kessleri Günther; introduced only within the interconnected Danube and Rhine River system, and N. melanostomus (Pallas); widely introduced throughout several river systems in Europe and North America. Higher values of Fulton's condition factor were observed in non‐native populations of both goby species. Neogobius melanostomus attained higher gonadosomatic index values in non‐native populations, indicating potential increased investment in reproduction in its new area. A lower splenosomatic index was observed in non‐native populations, especially in N. melanostomus. Parasite infracommunity richness and mean abundance were higher in N. kessleri in both native and non‐native populations, suggesting higher susceptibility of N. kessleri to these parasites. Non‐native populations of both hosts showed higher infra‐community richness as a result of acquiring parasites native to the new area, but lower parasite abundance. Differences in success of the introduction and establishment in new areas between the two fish species may be associated with a relatively low parasite infection rate and a higher gonadosomatic index in non‐native populations of N. melanostomus in comparison to N. kessleri.
Serum oxidizability potential is associated with age and exercise test results
Authors: Goldhammer Ehud , Rivlin Yelena , Shnizer Sergei , Shanati Allah , Sagiv Moran , Rosenschein Uri 
Published: April 2010

Abstract
The purpose of this paper is to find out whether serum oxidizability potential measured before an exercise test (EXT) correlates with age and ischemic heart disease severity. Oxidizability potential was determined in 3 age groups, in gr. I patients < 45 years, in gr. II age
$$ {\hbox{range}} = {45} - {7}0{\hbox{years}} $$
, and in gr. III patients > 70 years. Included subjects had chronic ischemic heart disease (IHD) and underwent a symptom-limited EXT upon initiation of a cardiac rehabilitation program. The thermo-chemiluminescence (TCL) assay was used to assess serum oxidizability potential. This assay is based on heat-induced oxidation of serum, leading to the formation of electronically excited species in the form of unstable carbonyls, which further decompose into stable carbonyls and light energy (low chemiluminescence). Measured photons emission is represented by a kinetic curve which is described by its amplitude and slope (=ratio). We assessed the correlations of TCL ratio with age, exercise duration, metabolic equivalents (METS), maximal heart rate (mHR), maximal systolic BP, >1 mm S-T depression, diabetes, hypertension, smoking, left ventricular ejection fraction (LVEF)> or <40%, previous myocardial infarction, and aorto-coronary bypass surgery. A high TCL ratio (%) correlated well with METS (r = 0.82), mHR (r = 0.77) and with exercise-induced S-T segment shift (r = 0.86, p < 0.05). A lower serum oxidizability potential, expressed as a low TCL ratio, thus suggestive of a previous high oxidative stress, was found in the two older age groups compared to gr. I (<45 years), p = 0.041, and in particular, in gr. III patients with low LVEF%. The TCL ratio (%) in gr. III was 188.7 ± 14.5, 192 ± 17 in gr. II, and 214 ± 13 in gr. I (p < 0.05), and was 166 ± 13.1 in gr. III with LVEF < 45% as compared to 271 ± 15.7 in gr. I patients with LVEF > 45% (p < 0.01). A trend for lower TCL ratio (%) was found in diabetic, hypertensive, and post-coronary bypass surgery patients. A paradoxically low TCL ratio (low oxidizability potential) was observed in patients without S-T depression compared to patients with S-T depression (189 ± 22 vs. 201 ± 15, p = NS), due to the fact these patients had a much lower LVEF% and a lower exercise capacity. Serum oxidizability potential is associated with age, EXT parameters, results, and IHD severity. TCL ratio is an “easy-to-measure marker” that might be incorporated into risk assessment and prediction in aged IHD patients.