bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of land surface evapotranspiration over the Heihe River basin based on the revised three‐temperature model
Authors: Luo Xinping , Wang Keli , Jiang Hao , Sun Jia , Zhu Qingliang
Published: May 2011

Evaporation and heat transfer mechanisms differ for different types of soils. In this study, Evapotranspiration (ET) models for the bare soil, vegetation land, and the mixed regions were developed based on the Land Surface Energy Balance Theory. Surface energy fluxes and daily ET of the Heihe River Basin were estimated using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data and meteorological observation data, including the daily duration time of the sun, air temperature, etc. based on the revised three‐temperature model (3T model), and then the distribution maps of ET were retrieved. Thereafter, Evaporator pan (E‐601) measurements obtained from meteorological observation stations in the study area were chosen to validate the accuracy of the calculated ET. Results showed that the maximum absolute error was 1·70 mm/d, whereas the minimum was 0·05 mm/d, which indicated that the revised 3T model was of adequate accuracy in estimating ET in the study area and could be extended to the regional scale. Also, the spatial distribution of surface ET was different in the upper, middle and lower reaches in the study area and fit with vegetation conditions. On the whole, the ET increased from desert of northeast to mountain of southwest. The results showed that the ET in the study area ranged from 0·06 to 7·00 mm/d, with an average value of 2·43 mm/d, on 2 August 2008. The highest ET values was from the forest or alpine meadow areas in the upper reaches, with more than 4 mm/d, the lowest values was from the Gobi desert in the lower reaches, with below 2 mm/d, and ET of oasis in the middle reaches was not only changed with the crop growth stage and vegetation conditions, but also controlled greatly by human activities, with more than 3·5 mm/d. Copyright © 2011 John Wiley & Sons, Ltd.
Forgiveness, depression, and suicidal behavior among a diverse sample of college students
Authors: Hirsch Jameson K. , Webb Jon R. , Jeglic Elizabeth L.
Published: June 2011

Depression and suicide are significant public health concerns for college‐age young adults. Meaning‐based characteristics, such as forgiveness, a voluntary coping process involving offering, feeling, or seeking a change from negative to positive cognitions, behaviors, and affect toward a transgressor, may buffer such poor mental health outcomes. Utilizing mediation analyses, we examined cross‐sectional associations between forgiveness, depression, and suicidal behavior in a diverse student sample reporting mild to severe depressive symptoms. The effect of self‐forgiveness on suicidal behavior was fully mediated by depression; self‐forgiveness was associated with depression and, in turn, with suicidal behavior. Forgiveness of others was directly associated with suicidal behavior. Prospective research is needed, yet self and other‐forgiveness may be appropriate targets for promotion in suicide prevention efforts. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–11, 2011.
DOES FOREIGN AID REDUCE ENERGY AND CARBON INTENSITIES OF DEVELOPING ECONOMIES?
Authors: Kretschmer Bettina , Hübler Michael , Nunnenkamp Peter
Published: June 2011

Advanced OECD countries are widely held responsible for containing global carbon emissions by providing financial and technical support to developing economies where emissions are increasing most rapidly. It is open to question, however, whether more generous official development assistance would help fight climate change effectively. Empirical evidence on the effects of foreign aid on energy and carbon emission intensities in recipient countries hardly exists. We contribute to closing this gap by considering energy use and carbon emissions as dependent climate‐related variables and the volume and structure of aid as possible determinants. In particular, we assessed the impact of aid that donors classify to be specifically related to energy issues. We performed dynamic panel Generalised Method of Moments and Least Squares Dummy Variable Corrected estimations. We found that aid tends to be effective in reducing the energy intensity of GDP in recipient countries. All the same, the carbon intensity of energy use is hardly affected. Scaling up aid efforts would thus be insufficient to fight climate change beyond improving energy efficiency. Copyright © 2011 John Wiley & Sons, Ltd.
The corrosion behavior of carbon steel in CO2‐saturated NaCl crevice solution containing acetic acid
Authors: Hu Q. , Guo X. , Zhang G. , Dong Z.
Published: June 2011

The corrosion behavior of X52 carbon steel electrodes in CO2‐saturated NaCl crevice solution containing HAc was investigated by electrochemical measurements. Chemical environment measurements by Cl− and pH microprobes show an enrichment of Cl− ions and an increase of pH values inside the crevice. Moreover, both increments could accelerate with the decreasing dimension of the crevice mouth due to the high diffusive resistance. When the electrode in the crevice solution is coupled with the electrode in bulk solution, the alkalization and the enrichment of Cl− ions in the crevice solution can result in a negative shift of potential of the electrode in crevice solution, while the potential of the electrode in bulk solution shifts positively during the corrosion process. Thus, a galvanic corrosion is established with the electrode in the crevice solution acting as anode while another in the bulk solution as cathode, i.e., the corrosion in the crevice solution was enhanced while the corrosion in the bulk solution was retarded. The anodic dissolution and the cathodic reduction processes dominate in the crevice solution and in the bulk solution, respectively.
Fabrication and characterization of micro‐arc oxidation (MAO) coatings on Mg‐Li alloy in alkaline polyphosphate electrolytes without and with the addition of K2TiF6
Authors: Song L. , Kou Y. , Song Y. , Shan D. , Zhu G. , Han E.‐H.
Published: June 2011

Micro‐arc oxidation (MAO) has been accomplished on Mg‐Li alloy in alkaline polyphosphate electrolytes without and with the addition of 10 g/L K2TiF6. The surface/cross‐section microstructures of the fabricated coatings were analyzed by scanning electron microscope (SEM); the compositions of the fabricated MAO coatings were analyzed by X‐ray diffraction (XRD) and energy dispersive X‐ray analysis (EDAX); the corrosion behaviors of bare and MAO coated Mg‐Li alloys were evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) in 3.5 wt% NaCl solution. Novel hybrid MAO coatings which showed hybrid composition of MgF2/Ti2O5/Ti6O11/MgO, as well as hybrid structure of a dense inner layer, a dense outer layer and an intermediate layer with some sealed/semi‐sealed pores, had been fabricated on Mg‐Li alloy in alkaline polyphosphate electrolytes with the addition of K2TiF6. Meanwhile, the corrosion resistance of the fabricated MAO coatings was improved obviously as the result of the addition of K2TiF6 in the electrolytes. Moreover, the multiple roles of ${\rm TiF}_{{\rm 6}}^{{\rm 2}{-} } $ on the MAO process accounted for the fabrication of the corrosion‐resistant hybrid MAO coatings.
Influences of cube texture on etched foil capacitance
Authors: Kuang F. , Li X. F. , Hong T. , Wang X. J. , Ma H.
Published: June 2011

The influences of aluminum cube texture on etched foil qualities and current efficiency were studied in this paper. The present results indicated that the decrease of cube texture (volume fraction) would lead to the decrease of tunnel densities on etched foils. Current efficiency changed little with cube texture and could reach up to 98%. The same current efficiency led to the same electrochemical corrosion weight loss, which caused the etched foils with a smaller tunnel density had a larger tunnel size. The same electrochemical corrosion weight loss would also lead to the etched foils produced by different cube texture foil have the same folding endurance. The etched foil produced by the foil with a better cube texture would have a larger tunnel density, which caused the capacitance of it was larger.
Modified EPR‐DL method for detection of the spinodal decomposition of 2205 duplex stainless steel
Authors: Stoulil J. , Bystriansky J.
Published: June 2011

The presented work deals with the possibility of electrochemical detection of the spinodal decomposition of duplex stainless steel's ferritic phase using the modified electrochemical potentiodynamic reactivation double loop (EPR‐DL) method. Specimens of FeCr23Ni6Mo3N (2205) steel exposed to the model low‐temperature annealing at 420 °C for up to 1000 h were used in the experiment. The specimens were evaluated using potentiodynamic curves measurements in chloride solutions and microhardness measurements. Despite hardening the ferritic phase for up to 1 h, a substantial drop of resistance to attack by chlorides was reported only after 1000 h of annealing. The modified EPR‐DL method in 2 M HCl + 0.1 M KSCN solution enables sensitive identification of the spinodal decomposition rate already from early stages.
In situ temperature measurement on the metal/oxide/electrolyte interface during the anodizing of aluminum
Authors: Schneider M. , Lämmel C. , Heubner C. , Michaelis A.
Published: June 2011

The temperature development during anodizing processes plays a key role in the case of industrial hard anodizing processes. Commonly, only the bath temperature is controlled; although it is well known that the bath temperature can significantly deviate from the temperature across the interface metal/oxide/electrolyte no investigation is known which shows the temperature deviation in this area. The authors have built a special experimental setup which allows a local temperature measurement across the interface. The results show the possibility of local resolved temperature measurements and the calculation of the heat flow into the metal and the anodizing bath. Based on this knowledge a target control of the current‐voltage‐regime avoids the formation of thermally caused cracks in hard anodized layers.
Inhibitory control during smooth pursuit in Parkinson's disease and Huntington's disease
Authors: Henderson Tracy , Georgiou‐Karistianis Nellie , White Owen , Millist Lynette , Williams David R. , Churchyard Andrew , Fielding Joanne
Published: May 2011

The basal ganglia are involved in the preferential selection and suppression of competing responses. Parkinson's disease and Huntington's disease are 2 prototypical basal ganglia disorders that feature impaired inhibitory control, a function of poor conflict resolution. Previous saccadic studies showed that individuals with Parkinson's disease experience difficulty suppressing unwanted ocular motor responses, whereas evidence for a similar difficulty in Huntington's disease is more equivocal. Relative to saccades, few research studies have examined inhibitory control processes in the context of an ongoing smooth pursuit task. In this study, we examined the ability of 16 patients with Parkinson's disease and 12 patients with Huntington's disease to suppress automatic responses to irrelevant distracters that transiently appeared during the tracking of a moving visual stimulus. Compared with an equivalent number of age‐matched controls, patients with Parkinson's disease generated proportionately more saccades to distracter stimuli. This was particularly evident for distracters appearing far away from the target. Conversely, whereas individuals with early‐stage Huntington's disease and healthy controls made a comparable number of errors toward distracter stimuli, those in a more advanced clinical stage demonstrated significantly poorer inhibitory control. The current findings in parkinsonian patients replicate those previously reported in the saccadic and manual response literature, demonstrating difficulty inhibiting a competing motor response. However, in Huntington's disease we demonstrate for the first time that inhibitory control declines in more advanced‐disease stages. This suggests that ocular motility may provide a sensitive marker of clinical disease progression in Huntington's disease. © 2011 Movement Disorder Society
T2‐weighted MRI of post‐infarct myocardial edema in mice
Authors: Beyers Ronald J. , Smith R. Scott , Xu Yaqin , Piras Bryan A. , Salerno Michael , Berr Stuart S. , Meyer Craig H. , Kramer Christopher M. , French Brent A. , Epstein Frederick H.
Published: May 2011

T2‐weighted, cardiac magnetic resonance imaging (T2w CMR) can be used to noninvasively detect and quantify the edematous region that corresponds to the area at risk (AAR) following myocardial infarction (MI). Previously, CMR has been used to examine structure and function in mice, expediting the study of genetic manipulations. To date, CMR has not been applied to imaging of post‐MI AAR in mice. We developed a whole‐heart, T2w CMR sequence to quantify the AAR in mouse models of ischemia and infarction. The ΔB0 and ΔB1 environment around the mouse heart at 7 T were measured, and a T2‐preparation sequence suitable for these conditions was developed. Both in vivo T2w and late gadolinium enhanced CMR were performed in mice after 20‐min coronary occlusions, resulting in measurements of AAR size of 32.5 ± 3.1 (mean ± SEM)% left ventricular mass, and MI size of 50.1 ± 6.4% AAR size. Excellent interobserver agreement and agreement with histology were also found. This T2w imaging method for mice may allow for future investigations of genetic manipulations and novel therapies affecting the AAR and salvaged myocardium following reperfused MI. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Closed circuit MR compatible pulsatile pump system using a ventricular assist device and pressure control unit
Authors: Lorenz R. , Benk C. , Bock J. , Stalder A.F. , Korvink J.G. , Hennig J. , Markl M.
Published: May 2011

The aim of this study was to evaluate the performance of a closed circuit MR compatible pneumatically driven pump system using a ventricular assist device as pulsatile flow pump for in vitro 3D flow simulation. Additionally, a pressure control unit was integrated into the flow circuit. The performance of the pump system and its test‐retest reliability was evaluated using a stenosis phantom (60% lumen narrowing). Bland–Altman analysis revealed a good test–retest reliability (mean differences = −0.016 m/s, limits of agreement = ±0.047 m/s) for in vitro flow measurements. Furthermore, a rapid prototyping in vitro model of a normal thoracic aorta was integrated into the flow circuit for a direct comparison of flow characteristics with in vivo data in the same subject. The pneumatically driven ventricular assist device was attached to the ascending aorta of the in vitro model to simulate the beating left ventricle. In the descending part of the healthy aorta a flexible stenosis was integrated to model an aortic coarctation. In vivo and in vitro comparison showed significant (P = 0.002) correlations (r = 0.9) of mean velocities. The simulation of increasing coarctation grade led to expected changes in the flow patterns such as jet flow in the post‐stenotic region and increased velocities. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Characterisation of rock aggregate breakage properties using realistic texture‐based modelling
Authors: Liu Hongyuan , Lindqvist Per‐Arne , Åkesson Urban , Kou Shaoquan , Lindqvist Jan‐Eric
Published: May 2011

Realistic texture‐based modelling methods, that is microstructural modelling and micromechanical modelling, are developed to simulate the rock aggregate breakage properties on the basis of the rock actual microstructure obtained using microscopic observations and image analysis. The breakage properties of three types of rocks, that is Avja, LEP and Vandle taken from three quarries in Sweden, in single aggregate breakage tests and in inter‐aggregate breakage tests are then modelled using the proposed methods. The microstructural modelling directly integrates the microscopic observation, image analysis and numerical simulation together and provides a valuable tool to investigate the mechanical properties of rock aggregates on the basis of their microstructure properties. The micromechanical modelling takes the most important microstructure properties of rock aggregates into consideration and can model the major mechanical properties. Throughout this study, it is concluded that in general, the microstructure properties of rock aggregate work together to affect their mechanical properties, and it is difficult to correlate a single microstructure property with the mechanical properties of rock aggregates. In particular, for the three types of rock Avja, LEP and Vandle in this study, crack size distribution, grain size and grain perimeter (i.e. grain shape and spatial arrangement) show good correlations with the mechanical properties. The crack length and the grain size negatively affect the mechanical properties of Avja, LEP and Vandle, but the perimeter positively influences the mechanical properties. Besides, the modelled rock aggregate breakage properties in both single aggregate and inter‐aggregate tests reveal that the aggregate microstructure, aggregate shape and loading conditions influence the breakage process of rock aggregate in service. For the rock aggregate with the same microstructure, the quadratic shape and good packing dramatically improve its mechanical properties. During services, the aggregate is easiest to be fragmented under point‐to‐point loading condition, and then in the sequence of multiple‐point, point‐to‐plane and plane‐to‐plane loading conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Loss of epithelial oestrogen receptor α inhibits oestrogen‐stimulated prostate proliferation and squamous metaplasia via in vivo tissue selective knockout models
Authors: Chen Ming , Yeh Chiuan‐Ren , Chang Hong‐Chiang , Vitkus Spencer , Wen Xing‐Qiao , Bhowmick Neil A. , Wolfe Andrew , Yeh Shuyuan
Published: June 2011

Squamous metaplasia (SQM) is a specific phenotype in response to oestrogen in the prostate and oestrogen receptor (ER) α is required to mediate this response. Previous studies utilizing tissue recombination with seminal vesicle (SV) mesenchyme and prostatic ductal tips from wild type and ERαKO mice suggested that both epithelial and stromal ERα are necessary for SQM. However, tissue recombination is conducted in the renal capsule of immune‐deficient mice, in which the microenvironment is different from normal prostate microenvironment in the intact mice. Furthermore, whether the requirement of stromal ERα in the SV for developing SQM is the same as in the prostate is unknown. Therefore, there is a clear need to evaluate the respective roles of ERα in prostate epithelial versus stromal compartments in the intact mouse. Here we generated a mouse model that has selectively lost ERα in either stromal (FSP‐ERαKO) or epithelial prostate cells (pes‐ERαKO) to determine the requirements of ERα for oestrogen‐stimulated prostate proliferation and SQM. Our results indicated that FSP‐ERαKO prostates develop full and uniform SQM, which suggests that loss of the majority (∼65%) of stromal ERα will not influence oestrogen‐mediated SQM. In contrast, loss of epithelial ERα inhibits oestrogen‐mediated prostate growth and SQM evidenced by decreasing cytokertin 10 positive squamous cell stratification and differentiation, by reduced ERα protein expression in SQM compared to wild type mice ERα, and by the presence of normal proliferative activities in the oestrogen‐treated pes‐ERαKO prostates. These in vivo results suggest that epithelial ERα is required for oestrogen‐mediated proliferative response and could be an appropriate target for preventing aberrant oestrogen signalling in the prostate. Copyright © 2011 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Effect of confinement on power‐law fluid flow past a circular cylinder
Authors: Rao M.K. , Sahu Akhilesh K. , Chhabra R.P.
Published: May 2011

The role of confinement on the flow of power‐law fluids past a cylinder confined symmetrically between two parallel walls has been investigated numerically over wide ranges of conditions as follows: power‐law index (0.4 ≤n≤ 1.8), Reynolds number (40 ≤Re≤ 140) and blockage ratio (2,4,6). For Newtonian fluids, moderate degree of confinement stabilizes the flow thereby delaying the onset of the laminar vortex shedding regime. Although similar stabilization also occurs in shear‐thickening fluids, this relationship is complex for shear‐thinning fluids. Depending upon the degree of shear‐thinning, the walls may stabilize or destabilize the flow. Extensive results are presented on streamline, vorticity contours and pressure profiles herein. The power‐law behavior exerts significant influence on the macroscopic momentum transfer characteristics also. Thus, the drag and lift coefficients and Strouhal number exhibit complex dependence on Reynolds number, blockage ratio and power‐law index. Finally, the present results are consistent with the limited data available in the literature. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers
Putative copper‐ and zinc‐binding motifs in Streptococcus pneumoniae identified by immobilized metal affinity chromatography and mass spectrometry
Authors: Sun Xuesong , Xiao Chuan‐le , Ge Ruiguang , Yin Xingfeng , Li Hui , Li Nan , Yang Xiaoyan , Zhu Ying , He Xiang , He Qing‐Yu
Published: May 2011

The aim of metalloproteomics is to identify and characterize putative metal‐binding proteins and metal‐binding motifs. In this study, we performed a systematical metalloproteomic analysis on Streptococcus pneumoniae through the combined use of efficient immobilized metal affinity chromatography enrichment and high‐accuracy linear ion trap‐Orbitrap MS to identify metal‐binding proteins and metal‐binding peptides. In total, 232 and 166 putative metal‐binding proteins were respectively isolated by Cu‐ and Zn‐immobilized metal affinity chromatography columns, in which 133 proteins were present in both preparations. The putative metalloproteins are mainly involved in protein, nucleotide and carbon metabolisms, oxidation and cell cycle regulation. Based on the sequence of the putative Cu‐ and Zn‐binding peptides, putative Cu‐binding motifs were identified: H(X)mH (m=0–11), C(X)2C, C(X)nH (n=2–4, 6, 9), H(X)iM (i=0–10) and M(X)tM (t=8 or 12), while putative Zn‐binding motifs were identified as follows: H(X)mH (m=1–12), H(X)iM (i=0–12), M(X)tM (t=0, 3 and 4), C(X)nH (n=1, 2, 7, 10 and 11). Equilibrium dialysis and inductively coupled plasma‐MS experiments confirmed that the artificially synthesized peptides harboring differential identified metal‐binding motifs interacted directly with the metal ions. The metalloproteomic study presented here suggests that the comparably large size and diverse functions of the S. pneumoniae metalloproteome may play important roles in various biological processes and thus contribute to the bacterial pathologies.
Water soluble poly(histamine acrylamide) with superior buffer capacity mediates efficient and nontoxic in vitro gene transfection
Authors: Luo Sibin , Cheng Ru , Meng Fenghua , Park Tae Gwan , Zhong Zhiyuan
Published: May 2011

Water‐soluble cationic polymers, poly(histamine acrylamide)s (PHAs), with superior buffer capacity at the endosomal pH range were designed, prepared, and investigated for non‐viral gene transfection. PHAs were obtained with molecular weights ranging from 9.2 to 28.7 kDa through controlled radical polymerization of histamine acrylamide (HA). Acid–base titration results displayed that all PHA polymers had a remarkably high buffer capacity of about 70% at pH 5.1–7.2. 12.7–28.7 kDa PHAs were able to effectively condense DNA into nano‐sized (<220 nm) polyplexes with moderate positive surface charges (+13–+19 mV) at N/P ratios ≥10/1. CCK assays indicated that polyplexes of 12.7 and 17.5 kDa PHAs were non‐toxic to COS‐7 cells up to a tested N/P ratio of 20/1. Interestingly, the in vitro transfection using pCMV‐Luc and pEGFP‐C1 plasmid DNA as reporter genes showed that polyplexes of 12.7 kDa PHA formed at an N/P ratio of 20/1 mediated efficient transfection in COS‐7 cells under 10% serum conditions, with transfection efficiencies comparable to that of 25 kDa polyethylenimine control. Their versatile design of structures, controlled synthesis, low cytotoxicity, and high transfection activity render PHA‐based cationic polymers particularly interesting for the development of safe and efficient non‐viral gene delivery systems. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.
Preparation, Characterization, and Catalytic Activity of Nanosized NiO and ZnO: Part 74
Authors: Kumar Dinesh , Kapoor Inder P. S. , Singh Gurdip , Siril Prem Felix , Tripathi Alok Mani
Published: June 2011

Nanocrystals of NiO and ZnO were prepared by a novel refluxing method and characterized by XRD and TEM. The average particles size of NiO and ZnO were found to be 6 and 31 nm, respectively, from the XRD patterns. These Transition Metal Oxide Nanocrystals (TMONs) were found to catalyze the thermal decomposition of 5‐nitro‐1, 2, 4‐triazol‐3‐one (NTO). Between the two TMOs, ZnO was found to have better catalytic activity than NiO. Kinetic parameters for the isothermal decomposition of NTO in presence and absence of these metal oxides were obtained using a model‐free isoconversional method. The activation energy for NTO, NTO+1 %NiO, and NTO+1 %ZnO was found to be 60.1, 52.1, and 47.9 kJ mol−1 and a similar order was found from the explosion studies (36.1, 31.6, and 27.4 kJ mol−1, respectively).
Crystal structure and enzymatic characterization of thymidylate synthase X from Helicobacter pylori strain SS1
Authors: Wang Kuifeng , Wang Qi , Chen Jing , Chen Lili , Jiang Hualiang , Shen Xu
Published: June 2011

Thymidylate synthase X (ThyX) catalyzes the methylation of dUMP to form dTMP in bacterial life cycle and is regarded as a promising target for antibiotics discovery. Helicobacter pylori is a human pathogen associated with a number of human diseases. Here, we cloned and purified the ThyX enzyme from H. pylori SS1 strain (HpThyX). The recombinant HpThyX was discovered to exhibit the maximum activity at pH 8.5, and Km values of the two substrates dUMP and CH2H4folate were determined to be 15.3 ± 1.25 μM and 0.35 ± 0.18 mM, respectively. The analyzed crystal structure of HpThyX with the cofactor FAD and the substrate dUMP (at 2.31 Å) revealed that the enzyme was a tetramer bound to four dUMP and four FAD molecules. Different from the catalytic feature of the classical thymidylate synthase (ThyA), N5 atom of the FAD functioned as a nucleophile in the catalytic reaction instead of Ser84 and Ser85 residues. Our current work is expected to help better understand the structural and enzymatic features of HpThyX thus further providing valuable information for anti‐H. pylori inhibitor discovery.
Serum prosaposin levels are increased in patients with advanced prostate cancer
Authors: Koochekpour Shahriar , Hu Siyi , Vellasco‐Gonzalez Cruz , Bernardo Ruiz , Azabdaftari Gissu , Zhu Guodong , Zhau Haiyen E. , Chung Leland W.K. , Vessella Robert L.
Published: May 2011

BACKGROUND

We previously cloned prosaposin (PSAP) from metastatic castrate‐resistant prostate cancer (mCRPCa) cells and demonstrated its genomic amplification and/or overexpression in metastatic PCa cell lines, xenografts, and lymph node metastases. The clinicohistopathological significance of serum PSAP levels and its tissue expression and association with predictive or prognostic variable in primary or advanced PCa are not known.

METHODS

We examined PSAP expression by immunohistochemical staining during early embryogenic development of the prostate and within a large tissue microarray which included 266 benign and malignant prostate tissues. In addition, serum PSAP levels in the age‐adjusted normal male population and in 154 normal individuals and patients with primary or mCRPCa were measured by an ELISA assay.

RESULTS

Univariate and multivariate analyses revealed a significant and inverse association between PSAP expression and clinical stages II and III tumors, dominant Gleason patterns 3 and 4, and seminal vesicle invasion. In the normal male population, the lowest serum PSAP level was detected before puberty, peaked at the most reproductive age group (20‐ to 39‐year old), and then, decreased to a range between the two groups for men above 40‐year old. Regardless of age and when compared with normal individuals, serum PSAP levels significantly decreased in primary organ‐confined PCa, but increased in those with mCRPCa.

CONCLUSION

Our results show that PSAP has the potential to differentiate between primary and advanced PCa. Additional large‐scale studies are needed to define the usefulness of tissue expression or serum PSAP levels as a diagnostic or prognostic marker or as a therapeutic target in PCa. Prostate 72:253–269, 2012. © 2011 Wiley Periodicals, Inc.
Characterization of dislocation arrays in AlN single crystals grown by PVT
Authors: Dalmau Rafael , Moody Baxter , Xie Jinqiao , Collazo Ramón , Sitar Zlatko
Published: May 2011

The density and distribution of extended defects in AlN single crystals grown by physical vapor transport (PVT) was studied by bright field and polarized light microscopy, defect‐selective etching, and high resolution X‐ray diffraction (HRXRD). Etch pits associated with dislocation arrays forming low angle grain boundaries (LAGB) were observed and two types of LAGB were identified. Reduction of LAGB in AlN grown under reduced radial temperature gradients, as estimated by simulation of the growth cell, was demonstrated.
Towards experimental identification of vacancy complexes in InN
Authors: Rauch Christian , Makkonen Ilja , Tuomisto Filip
Published: June 2011

In this contribution we present ab initio calculations of positron states and annihilation at vacancies and vacancy complexes in InN. Momentum distributions of annihilating electron–positron pairs in indium (VIn) and nitrogen vacancies (VN) as well as mixed vacancy clusters are calculated. Based on the modelled data the possibility of their experimental detection and distinction using positron annihilation spectroscopy is discussed. No localization of the positron density is found for isolated VN and VN clusters of up to 4VN. On the other hand, VIn and mixed vacancy clusters act as efficient positron traps in InN. While the calculated momentum distributions for the divacancy and VIn are quite close, mixed vacancy clusters which contain one VIn and two or more VN show well distinct spectra, that could be distinguished in suitable positron annihilation experiments.
Pressure induced phase transitions in transition metal nitrides: Ab initio study
Authors: Srivastava Anurag , Chauhan Mamta , Singh R. K.
Published: June 2011

We have analyzed the stability of transition metal nitrides (TMNs) XN (X = Ti, Zr, Hf, V, Nb, Ta) in their original rocksalt (B1) and hypothetical CsCl (B2) type phases under high compression. The ground state total energy calculation approach of the system has been used through the generalized gradient approximation (GGA) with the Perdew‐Burke‐Ernzerhof (PBE) type parameterization as exchange correlation functional. In the whole series of nitrides taken into consideration, tantalum nitride is found to be the most stable. We have observed that under compression the original B1‐type phase of these nitrides transforms to a B2‐type phase. We have also discussed the computation of ground state properties, like the lattice constant (a), bulk modulus (B0) and first order pressure derivative of the bulk modulus (B'0) of the TMNs and their host elements.
An optical and dielectric spectroscopy study of Er3+‐doped KTaO3
Authors: Trepakov Vladimir , Skvortsov Alexander , Poletaev Nikolai , Potůček Zdeněk , Nuzhnyy Dmitry , Jastrabik Lubomír , Dejneka Alexandr
Published: June 2011

We report the results of a multifaceted study of optical and dielectric properties of erbium‐doped (500 ppm) potassium tantalate incipient ferroelectric single crystals. Studies of optical absorption and photoluminescence spectra allowed us to determine the system of energy levels that control the main internal optical transitions in the 4f electronic shell of Er3+ in KTaO3. It was found that at least two types of Er3+ centres, major and minor ones, are present. The major centres are non‐cubic, formed by Er3+ substituting for K+ sites; these are responsible for the n‐type conductivity of KTaO3:Er crystals. Wideband optical absorption with a maximum at 1.13 eV (λ = 1097 nm) was observed in the near‐IR range and was attributed to polaron formation. Low‐temperature far‐infrared reflectivity studies revealed an increase in the frequency of the lowest transverse optical mode and a decrease in the dielectric permittivity in comparison with undoped KTaO3 crystals. This stiffening means the suppression of the ferroelectric instability in the system.
Magnetic properties of FeCuNbSiB nanocrystallized by flash annealing under high tensile stress
Authors: Herzer Giselher , Budinsky Viktoria , Polak Christian
Published: June 2011

We have investigated the creep induced anisotropy, magnetostriction, domain structure and coercivity of nanocrystalline Fe73.5Cu1Nb3Si15.5B7 crystallized by flash annealing under high tensile stress up to 800 MPa. The samples reveal a magnetic easy plane perpendicular to the stress axis with anisotropy constants up to Ku ≈ 12 kJ/m3 which even exceed the local magneto‐crystalline anisotropy (K1 ≈ 8 kJ/m3) of the crystalline Fe–Si phase. Although coercivity increases with Ku, it remains reasonably small even for huge induced anisotropy constants. The coercivity mechanism can be understood from the interplay of the induced anisotropy and the random fluctuations of the local magneto‐crystalline anisotropy of the crystallites. The tensile stress applied during annealing also affects the saturation magnetostriction constant λs. Thus, λs decreases with increasing magnitude of the annealing stress. This behaviour is compared to the elastic stress dependence of magnetostriction. The latter is well‐known for amorphous Co‐base alloys, but can also be observed in nanocrystalline alloys. The experimental results will be discussed theoretically in terms of the strain dependence of the magnetic anisotropy energy which ultimately provides the physical origin of magnetostrictive phenomena.
The effect of chemical disorder on the magnetic anisotropy of strained Fe–Co films
Authors: Neise C. , Schönecker S. , Richter M. , Koepernik K. , Eschrig H.
Published: June 2011

Strained Fe–Co films have recently been demonstrated to exhibit a large magnetocrystalline anisotropy (MCA) and thus to be of potential interest as magnetic storage material. Here, we show by means of density‐functional (DF) calculations, that chemical order can remarkably enhance the MCA. We also investigate the effect of relaxation perpendicular to the applied strain and evaluate the strain energy as a function of Co concentration and substrate lattice parameter. On this basis, favourable preparation routes for films with a large perpendicular anisotropy are suggested.
Effects of Y and Zn atoms on the elastic properties of Mg solid solution from first‐principles calculations
Authors: Yang Fang , Fan Tou‐Wen , Wu Jian , Tang Bi‐Yu , Peng Li‐Ming , Ding Wen‐Jiang
Published: June 2011

The effects of Y and Zn atoms on elastic properties of Mg solid solution are investigated by first‐principles calculations based on density function theory. Five supercell models (Mg96, Mg95Y1, Mg94Y2, Mg95Zn1 and Mg94Zn2) are adopted to simulate the variation of solute atoms content. Structural optimization is performed firstly, and then the five independent elastic constants of Mg solid solution are calculated. The bulk modulus B, shear modulus G, Young's modulus E and Poisson ratio ν are also derived by Voigt–Reuss–Hill (VRH) approximation, indicating a strong dependence of the elastic modulus on concentration of the solute atoms. Using the bulk modulus/shear modulus ratio (B/G), the change in the ductility of Mg solid solution with the solute atom content is further studied. In the end, the electronic density of states (DOS) is calculated and discussed.
Current transport through AlInN/GaN multilayers used as n‐type cladding layers in edge emitting laser diodes
Authors: Charash Ragh , Kim‐Chauveau Hyonju , Vajpeyi Agam , Akther Mahbub , Maaskant Pleun P. , Frayssinet Eric , de Mierry Philippe , Duboz Jean‐Yves , Corbett Brian
Published: June 2011

The current transport properties of an n ‐doped, lattice matched AlInN layer with multiple, periodic GaN insertions are reported. Samples with three and seven insertions were grown and mesa structures were etched through the AlInN structures to different depths to determine the voltage contribution from each heterointerface. The quality of the AlInN surface improved with the GaN insertions and with reducing the thickness of the individual AlInN layers from 80 nm to 55 nm. Simulations suggest that the large conduction band discontinuity can lead to high turn on voltages which can be reduced by high levels of doping. Current‐voltage measurements through the full structure show a diode characteristic which is temperature activated. A quasi‐linear current‐voltage characteristic is measured when the current is driven only through the uppermost GaN interlayer with 80 nm thick AlInN layers, indicating current leakage through defects in these layers (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Drift region optimization in high‐voltage GaN MOS‐gated HEMTs
Authors: Li Zhongda , Chow T. P.
Published: June 2011

The design of AlGaN/GaN heterojunction in high‐voltage lateral GaN MOS‐HEMT was studied and optimized. The effect of the heterojunction on the breakdown voltage of the device was studied using numerical simulations. The effect of the addition of a GaN cap layer on top of the AlGaN/GaN structure was evaluated, showing a higher breakdown voltage as well as a lower oxide field at the gate corner, due to the better Reduced Surface Field (RESURF) effect that originated from the balanced polarization charges. Further a 2‐zone RESURF design was achieved by etching part of the GaN cap in the drift region. The 2‐zone RESURF device showed 33% improvement in breakdown voltage from simulations compared with single zone RESURF devices. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
AlGaN/GaN HFET biosensors working at subthreshold regime for sensitivity enhancement
Authors: Wen Xuejin , Gupta Samit , Nicholson Theodore R. , Lee Stephen C. , Lu Wu
Published: June 2011

In this paper, we report an AlGaN/GaN heterostructure field effect transistor biosensor with enhanced sensitivity at subthreshold regime for streptavidin detection. The AlGaN surface is functionalized by oxidization, silanization, and biotinylation for detection of streptavidin. Using a Pt reference electrode dipped into the buffer as a gate, the device is configured as a field effect transistor that can be operated at different regimes. The sensing results show that the device sensitivity is strongly dependent on the ionic strength in the buffer. The sensitivity can be significantly improved in subthreshold regime in comparison with a floating gate device configuration. With the floating gate configuration, the sensitivity at a streptaviding concentration of 47.3 nM is 11.3% whereas the sensitivity is enhanced to 67.4% at a concentration of 4.73 nM when the device is biased at the subthreshold regime. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties and Judd‐Ofelt parameters of Sm3+ doped BiO1.5‐WO3‐TeO2 glasses
Authors: Fujiwara Takeshi , Hayakawa Tomokatsu , Nogami Masayuki , Duclère Jean‐René , Thomas Philippe
Published: June 2011

In this paper, the optical absorption and emission spectra of Sm3+ ions in 5BiO1.5‐20WO3‐75TeO2 glasses (0.2, 0.5, 1.0, 2.0 and 3.0 mol% of Sm3+) are presented. These glasses have been developed very recently and are found to exhibit excellent third‐order nonlinear properties. A Judd‐Ofelt analysis has been performed in order to calculate various optical parameters such as Judd‐Ofelt parameters, radiative transition probabilities, and stimulated emission cross‐section. According to the computed Judd‐Ofelt parameters, the symmetry of the sites occupied by the Sm3+ ions increased as the amount of Sm2O3 was increased, and the covalency decreased above 1.0 mol%. The results of the stimulated emission cross‐section revealed that the 4G5/2 → 6H7/2 transition of 1.0 mol% Sm3+ in 5BiO1.5‐20WO3‐75TeO2 glasses could be promising for lasing action.

Emission spectrum of 1.0 mol% Sm2O3‐doped 5BiO1.5‐20WO3‐75TeO2 glass. Judd‐Ofelt parameters (Ωλ) and peak emission stimulated cross‐section σ (λp) are shown in the figure. The 4G5/2 → 6H7/2 transition is promising for lasing action. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectra and third‐order nonlinear optical Z‐scan properties of MO‐Nb2O5‐TeO2 (M=Zn, Mg, Ca, Sr, Ba) glasses
Authors: Hayakawa Tomokatsu , Suhara Toshiki , Fujiwara Takeshi , Nogami Masayuki , Thomas Philippe
Published: June 2011

In this paper, the third‐order nonlinear optical susceptibilities, χ(3), of tellurite glasses with MO‐Nb2O5‐TeO2 system (M = Zn, Mg, Ca, Sr, Ba) was investigated by Z‐scan measurement using Ti:Sapphire femtosecond laser pulses. The relationship between the nonlinear optical properties and the glass structures, estimated by Raman spectroscopy, was discussed. The experimental results revealed that when alkaline‐earth ions (M2+) was doped in Nb2O5‐TeO2 binary network system the break in TeIV‐eqOax‐TeIV chain structure necessarily occurred but the terminations of –TeIV‐Oeq‐NbVI‐O‐ + M2+ + ‐Oax‐TeIV‐ or –TeIV‐Oeq‐ + M2+ + ‐O‐NbVI‐Oax‐TeIV‐ were more preferentially induced with an assist of NbO6 polyhedron, which produced TeO3+1 units or stabilized TeIVO4 units (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence of europium doped LiInO2 powder
Authors: Đačanin Lj. R. , Dramićanin M. D. , Nikolić M. G. , Mitrić M. , Petrović D. M. , Lukić S. R.
Published: June 2011

Lithium‐indium oxide is one of the candidate materials as solid‐state scintillators for solar neutrinos due to an inverse β–‐decay of 115In to 115Sn. On the other hand, when doped with rare‐earth ions such as Eu3+ or Sm3+, it becomes a promising phosphor material. In this report we present a simple solid‐state procedure for preparation of LiInO2:Eu3+ powders. X‐ray diffraction confirmed prod‐uct in tetragonal structural form (space group: I41/amd) and no impurity phases were detected. Then, high resolution photoluminescence emission measurements were performed at room and low temperatures to find 5D0 → 7FJ. Emission kinetics from 5D0 level exhibited pure single exponential behavior with lifetime of about 1.5 ms. Maximum energy splitting of 7F1 manifold is recorded as a function of temperature (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bulk heterojunction organic photovoltaic cell fabricated by the electrospray deposition method using mixed organic solvent
Authors: Fukuda Takeshi , Takagi Kenji , Asano Takashi , Honda Zentaro , Kamata Norihiko , Ueno Keiji , Shirai Hajime , Ju Jungmyoung , Yamagata Yutaka , Tajima Yusuke
Published: May 2011

A high‐efficiency bulk heterojunction organic photovoltaic cell (OPV) was achieved by the electrospray deposition method. The surface roughness of the P3HT:PCBM thin film can be reduced using the mixed solvent consisting of o‐dichlorobenzene (o‐DCB) and acetone. The effect of acetone concentration is related to its dielectric constant. Under an optimized concentration of acetone in o‐DCB (20 vol%), the P3HT/PCBM active layer with a smooth surface can be formed, and the power conversion efficiency of the OPV was 1.9%.

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(© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An algebraic approach to the collinear collision N2 + N2 in the semiclassical approximation
Authors: Santiago R. D. , Álvarez‐Bajo O. , Arias J. M. , Gómez‐Camacho J. , Lemus R.
Published: May 2011

An algebraic model to describe the collinear inelastic collision N2 + N2 in the semiclassical approximation is presented. The interactions for the diatomic systems are modeled in terms of Morse potentials, whereas an exponential function is taken for the interactions between the nearest atoms of the diatomic systems. This problem is treated in the interaction picture, where an approximation of the interaction potential in terms of the generators of three SU(2) groups is proposed, two corresponding to the Morse oscillators and the third one to the interaction. The transition probabilities are given in terms of a sum of products of three Wigner's d(β) functions corresponding to the three SU(2) groups. Our results are compared with exact quantum mechanical calculations. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
DFT studies of homogeneous catalysis in the gas phase: Dehydration kinetics of several tertiary alcohols with hydrogen chloride
Authors: Mora Jose R. , Marquez David J. , Marquez Edgar , Loroño Marcos , Cordova Tania , Chuchani Gabriel
Published: May 2011

The mechanisms for the acid‐catalyzed gas‐phase dehydration of the tertiary alcohols 2‐methyl‐2‐propanol, 2‐methyl‐2‐butanol, and 2‐methyl‐2‐pentanol were examined at B3LYP/6‐31G(d), B3LYP/6‐31G(d,p), B3LYP/6‐31G(2d,p), B3LYP/6‐31G(2d,2p), B3PW1/6‐31G(d), B3PW1/6‐31G(d,p), B3PW1/6‐31G(2d,p), B3PW1/6‐31G(2d,2p), MPW91PW91/6‐31G(d), MPW91PW91/6‐31G(d,p), MPW91PW91/6‐31G(2d,p), and MPW91PW91/6‐31G(2d,2p) levels of theory. Calculation results suggest that the dehydration processes catalyzed by hydrogen chloride to give the corresponding olefin and water occur with the formation of Van der Waals complexes between the alcohol and hydrogen chloride. The transition states are six‐membered cyclic structures involving one molecule of HCl and one of the alcohol. These reactions appear to be molecular in nature. Analysis of the progress along the reaction coordinate, in terms of bond orders, NBO charges, and geometrical parameters suggest these reactions to be moderately polar and nonsynchronous and are dominated by the breaking of the HCl bond, together with an important cleavage of CO bond in the transition state. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Modeling for accurate dimensional scanning electron microscope metrology: then and now
Authors: Postek Michael T. , Vladár András E.
Published: May 2011

A review of the evolution of modeling for accurate dimensional scanning electron microscopy is presented with an emphasis on developments in the Monte Carlo technique for modeling the generation of the electrons used for imaging and measurement. The progress of modeling for accurate metrology is discussed through a schematic technology timeline. In addition, a discussion of a future vision for accurate SEM dimensional metrology and the requirements to achieve it are presented. SCANNING 33: 114–125, 2011. Published 2011 by Wiley Periodicals, Inc.