bluuebunny/crossref_metadata_2025_split huggingface dataset:
Treatment of children with B‐cell non‐Hodgkin lymphoma in a low‐income country
Authors: Moleti Maria Luisa , Al‐Hadad Salma Abbas , Al‐Jadiry Mazin Faisal , Al‐Darraji Amir Fadhil , Al‐Saeed Raghad Majid , De Vellis Annalisa , Piciocchi Alfonso , Uccini Stefania , Foà Robin , Testi Anna Maria 
Published: December 2010

AbstractBackgroundAn adapted LMB 96 derived protocol for B‐cell non‐Hodgkin lymphoma (NHL) was implemented at the pediatric oncology unit of the Children Welfare Teaching Hospital in Baghdad (Iraq) from 2000 to present. The purpose was to evaluate the feasibility and efficacy of this intensive therapeutic regimen in a limited resource country.MethodsPatients <15 years of age with high grade B‐cell NHL were included. A modified LMB 96 regimen was employed with a reduction of cyclophosphamide and methotrexate dosages due to inadequate laboratory facilities and supportive care.ResultsBetween 2000 and 2005, 261 children with non‐lymphoblastic NHL were registered; 239 were eligible for the analysis. Two patients had stage I disease, 20 stage II, 179 stage III, and 38 stage IV. Fifty‐two patients (22%) had bulky disease. Twelve children were assigned to therapeutic group A (low risk), 184 to group B (intermediate risk), and 43 to group C (high risk). One hundred and eighty‐four patients (77%) had a complete response after the COP pre‐phase. Sixty‐nine patients (29%) died during treatment. Twenty‐nine patients abandoned treatment. At 24 months, the overall survival rate of the entire patient population was 66% (CI 95%: 62.2–70.6) and the event‐free survival rate 53.3% (CI 95%: 50.0–56.8).ConclusionsThe treatment schedule proved effective, but the treatment‐related mortality due to infections and metabolic complications was very high owing to the limited supportive care available. The high rate of treatment abandonment was also an important cause of failure, especially for children living far away from the hospital. Pediatr Blood Cancer 2011;56:560–567. © 2010 Wiley‐Liss, Inc.
Stereochemical control in the structures of linear δ,α‐hybrid tripeptides containing tetrahydrofuran amino acids
Authors: Chakraborty Tushar Kanti , Kumar N. V. Suresh , Roy Saumya , Dutta Samit Kumar , Kunwar Ajit Chand , Sridhar Balasubramanian , Singh Harjinder 
Published: December 2010

AbstractStructural and electronic properties of diastereomers of tetrahydrofuran amino acids (TAA) derived tripeptide, Boc‐TAA‐Leu‐Val‐OMe, are studied using density functional theory. Predicted secondary folding patterns with hydrogen bonded pseudocycles of different sizes in peptides containing (2R,5S)‐cis‐TAA and (2S,5R)‐cis‐TAA are confirmed by detailed NMR studies of both, and single crystal X‐ray analysis of the former. A novel unusual folding pattern emanating from three‐centered hydrogen bond is found in peptide with (2R,5S)‐cis relationship. Stereochemical control on the orientation of interacting sites is substantiated by structural analysis of the peptides. Using natural bonding orbital and atoms in molecules analyses, charge transfer interactions are analyzed. Copyright © 2010 John Wiley & Sons, Ltd.
Degradable multisegmented polymers synthesized by consecutive radical addition‐coupling reaction of α,ω‐macrobiradicals and nitroso compound
Authors: Zhang Chengyu , Wang Qi 
Published: December 2010

AbstractA consecutive radical addition‐coupling reaction induced by spin‐trapping agent is applied to produce degradable multisegmented polymer using α,ω‐dibromo polymer as a precursor. The macroradical generated by single electron transfer process catalyzed by Cu/PMDETA from α,ω‐dibromo polymer can be efficiently captured by 2‐methyl‐2‐nitrosopropane (MNP), which results in nitroxide radical. The in situ formed nitroxide radical immediately undergoes cross‐coupling reaction with polymeric radical, generating block polymer bridged with alkoxyamine moiety. The consecutive radical addition‐coupling reaction generates multisegmented polymer via step‐growth mechanism. Different multisegmented polymers have been prepared from α,ω‐dibromo‐PS, PtBA, and PtBA‐PS‐PtBA. The block number of multisegmented polymers can be tailored by varying the feed ratio of α,ω‐dibromo precursor to MNP. The multisegmented polymer can be degraded in the presence of hydrogen atom donor or air, and the molecular weight distribution transformed back into shape of its original precursor as it is conjugated by alkoxyamine moieties. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Kinetic analyses of disulfide formation between thiol groups attached to linear poly(acrylamide)
Authors: Hisano Nobuharu , Iwata Hiroo , Teramura Yuji , Chen Hao , Ikada Yoshito 
Published: December 2010

AbstractKinetic analyses were carried out for formation of disulfide crosslinkages between thiol groups on linear polymers, poly(acrylamide‐co‐N‐acrylcysteamine) (P‐SH). Disulfide crosslinkages were formed by auto‐oxidation of pendant thiol groups or through the thiol‐disulfide exchange reaction induced by addition of disulfide compounds gluthathione. In the auto‐oxidation reaction, the rate constant for disulfide formation highly depended on pH values of the reaction mixtures and the P‐SH concentrations. Gelation rate is too slow to enclose living cells into hydrogel under physiological pH 7.4. The hydrogel formation rate can be accelerated by addition of disulfides, such as oxidized glutathione. In the later case, oxygen in the reaction mixture is not consumed. The thiol‐disulfide exchange reaction is much more suitable for the cell encapsulation than the thiol auto‐oxidation reaction. These findings give a basis for enclosure of living cells in a hydrogel. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Crystal structure and substrate‐binding mode of cellulase 12A from Thermotoga maritima
Authors: Cheng Ya‐Shan , Ko Tzu‐Ping , Wu Tzu‐Hui , Ma Yanhe , Huang Chun‐Hsiang , Lai Hui‐Lin , Wang Andrew H.‐J. , Liu Je‐Ruei , Guo Rey‐Ting 
Published: December 2010

AbstractCellulases have been used in many applications to treat various carbohydrate‐containing materials. Thermotoga maritima cellulase 12A (TmCel12A) belongs to the GH12 family of glycoside hydrolases. It is a β‐1,4‐endoglucanase that degrades cellulose molecules into smaller fragments, facilitating further utilization of the carbohydrate. Because of its hyperthermophilic nature, the enzyme is especially suitable for industrial applications. Here the crystal structure of TmCel12A was determined by using an active‐site mutant E134C and its mercury‐containing derivatives. It adopts a β‐jellyroll protein fold typical of the GH12‐family enzymes, with two curved β‐sheets A and B and a central active‐site cleft. Structural comparison with other GH12 enzymes shows significant differences, as found in two longer and highly twisted β‐strands B8 and B9 and several loops. A unique Loop A3‐B3 that contains Arg60 and Tyr61 stabilizes the substrate by hydrogen bonding and stacking, as observed in the complex crystals with cellotetraose and cellobiose. The high‐resolution structures allow clear elucidation of the network of interactions between the enzyme and its substrate. The sugar residues bound to the enzyme appear to be more ordered in the −2 and −1 subsites than in the +1, +2 and −3 subsites. In the E134C crystals the bound −1 sugar at the cleavage site consistently show the α‐anomeric configuration, implicating an intermediate‐like structure. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Stain etching of silicon with V2O5
Authors: Kolasinski Kurt W. , Yadlovskiy Julia 
Published: December 2010

AbstractFormation of porous silicon by etching of silicon with vanadium pentoxide dissolved in HF(aq) has been studied with infrared spectroscopy and electron microscopy. The rate of film growth depends strongly on the V2O5 concentration. Addition of ethanol greatly decreases the etch rate and changes the pore morphology from a mixture of {100} + {110} planes to predominantly {100} planes. A plot of thickness vs. etch time in aqueous solutions evolves from a quadratic to a linear dependence. A model is developed in which the surface area depends linearly on film thickness and the thickness exhibits the measured functional form with respect to time. In this model pores with a uniform diameter nucleate randomly, initially grow rapidly before slowing to grow at a constant rate. The pore density increases linearly with time then saturates causing the transition to the linear growth rate phase. This model simultaneously fits both the short time and long time behaviour of the thickness and surface area. Pore formation does not involve an oxide intermediate. Films emit brilliant visible photoluminescence, and are highly uniform both in structure and photoluminescence. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous silicon‐based microtexturing of textured monocrystalline silicon solar cells
Authors: Saadoun Moncef , Fethi Boujmil Mohamed , Aouida Selma , Ben Rabha Mohamed , Bessaïs Brahim 
Published: December 2010

AbstractThis work aims to examine the effects of surface micro‐texturing on the performances of pyramidal textured monocrystalline silicon (c‐Si) photovoltaic solar cells. The surface micro‐textures were performed on the emitter of alkaline‐textured PV solar cells without damaging the junction, using the HNO3/HF vapor etching (VE) method. Scanning Electron Microscopy (SEM) shows that vapour etched pyramidal textures exhibit a high texture density essentially composed of porous silicon (PS) microstructure. The VE technique notably decreases the surface reflectivity from 12% for alkaline‐textured c‐Si wafers to about 6% after micro‐texturing. Subsequent to VE, the sheet resistance was found to increase indicating a reduction of the dead layer. Fourier Transform Infrared Spectroscopy (FTIR) measurements showed that the PS‐based micro‐textures are hydrogen‐rich, which could have passivation capabilities of the emitter. Taking into account basic phenomena occurring during carrier photogeneration and minority carrier collection, we tried explaining the variation of the short circuit current density (Jsc), the open circuit voltage (Voc) and the Fill factor (FF) due to PS‐microtexturing of the emitter of c‐Si solar cells (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous II‐VI vs. porous III‐V semiconductors
Authors: Langa S. , Tiginyanu I. M. , Monaico E. , Föll H. 
Published: December 2010

AbstractIn this work a morphological comparison of porous structures obtained by means of electrochemical etching in II‐VI (ZnSe, CdSe) and III‐V (InP, GaAs, GaP) semiconductors is presented. It is shown that in III‐V semiconductors current‐line and crystallographically oriented pores can be grown, whereas in II‐VI semiconductors only current line oriented pores can form. The lack of crystallographically oriented pores in II‐VI is a possible reason why no long range order for the current line oriented pores was observed in these materials up to now. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antimony doped tin oxide nanoparticles and their assembly in mesostructured film
Authors: Müller Vesna , Rasp Matthias , Stefanic Goran , Günther Sebastian , Rathousky Jiri , Niederberger Markus , Fattakhova‐Rohlfing Dina 
Published: December 2010

AbstractMesoporous transparent conducting films of antimony‐doped tin oxide (ATO) were prepared by self‐assembly of crystalline ATO nanoparticles, which enables to obtain a fully crystalline frameworks with a sufficient electric conductivity. Such frameworks are promising as transparent electrodes with a high surface area, as shown for ferrocene molecules covalently immobilized within a conducting mesoporous matrix. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chemical resistance of porous silicon: photolithographic applications
Authors: Lai Meifang , Parish Gia , Dell John , Liu Yinong , Keating Adrian 
Published: December 2010

AbstractLow‐temperature passivation is employed in this study to improve the chemical resistance of porous silicon to both weak‐alkali and HF solutions, enabling complex and multi‐mask patterning of porous silicon. Passivation is achieved by annealing the film in N2 atmosphere at temperatures ranging from 560°C‐800°C. The resistance of the passivated porous silicon to both KOH and HF solutions was examined by immersing the sample into these solutions and working out the optical thickness change. It is shown that higher passivation temperatures result in improved chemical resistance. Infrared spectroscopy show that exposing the films to HF can remove the passivation layer, enabling repeated anodisation; the restoration of the hydrogen bond on the porous silicon surface after HF immersion makes repeated passivation and processing possible (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Porous silicon used as an oxide diffusion mask to produce a periodic micro doped n++/n regions
Authors: Dimassi Wissem , Jafel Hayet , Lajnef Mohamed , Ali Kanzari M. , Bouaïcha Mongi , Bessaïs Brahim , Ezzaouia Hatem 
Published: December 2010

AbstractThe realization of screen‐printed contacts on silicon solar cells requires highly doped regions under the fingers and lowly doped and thin ones between them. In this work, we present a low‐cost approach to fabricate selective emitter (n++/n doped silicon regions), using oxidized porous silicon (ox‐PS) as a mask. Micro‐periodic fingers were opened on the porous silicon layer using a micro groove machining process. Optimized phosphorous diffusion through the micro grooved ox‐PS let us obtain n++ doped regions in opened zones and n doped large regions underneath the ox‐PS layer. The dark I‐V characteristics of the obtained device and Fourier transform infrared (FTIR) spectroscopy investigations of the PS layer show the possibility to use PS as a dielectric layer. The Light Beam Induced Current (LBIC) mapping of the realized device, confirm the presence of a micro periodic n++/n type structure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of CdCl2 annealing treatment on CdS thin films and CdTe/CdS thin film solar cells
Authors: Bai Zhizhong , Wan Lei , Hou Zerong , Wang Deliang 
Published: December 2010

AbstractIn order to study the effect of CdCl2 annealing treatment on thin CdS films and CdTe/CdS thin film solar cells, a comparative study was carried out on three types of CdTe/CdS solar cells, which had different kinds of CdS window layer: as‐deposited CdS, air‐annealed CdS without CdCl2 pre‐coating, and CdCl2‐annealed CdS. When annealed in air the CdS film was partially oxidated to CdO and CdSO4. These oxides increased the series resistance of the CdTe solar cell and led to the lowest fill factor. The presence of CdCl2 on the surface of a CdS thin film during heat treatment in air protected it from oxidation and promoted the recrystallization of the CdS film, resulting in large and closely packed grains with a grain size of ∼ 50 ‐150 nm. CdTe/CdS solar cell with such a kind of CdS window layer showed the largest short circuit current and highest conversion efficiency of 12.4%. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristic of (Pb1‐xZnx)S tandem structured quantum dot‐sensitized solar cell having wide light absorbance
Authors: Shin Inyoung , Seo Hyunwoong , Son Min‐Kyu , Kim Jin‐Kyoung , Kim Heeje 
Published: December 2010

AbstractA quantum dot‐sensitized solar cell (QD‐SSC) is one of these new type solar cells because of their advantages such as the inverse Auger effect, the tuning the particle size. Many quantum dot semiconductors such as CdS, CdSe, PbS and PbSe are used as the sensitizers instead of the ruthenium dye molecules in the QD‐SSC. The light absorbance of the quantum dot materials is changed as the dipping cycle and the amount of the materials. Therefore, the light absorbance and the efficiency of the QD‐SSC can be increased by using these characteristics.In this study, we tried to widen the light absorbance of the QD‐SSC by changing the doping amounts of Pb and Zn in the (Pb1‐xZnx)S material. Finally, we fabricated the (Pb1‐xZnx)S tandem structured QD‐SSC. When the tandem structure multilayer as the layer which contains less Zn amount is placed on the bottom and the layer which contains more Pb amount is placed on the top side, the light absorbance is broaden effectively by using this tandem structure. As a result, we got the I‐V characteristics of (Pb1‐xZnx)S QD‐SSC with 3 multilayer, 0.38 V, 3.219 mA/cm2, 0.39 of FF, 0.48%. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel composite contact design and fabrication for planar Gunn devices for millimeter‐wave and terahertz frequencies
Authors: Khalid A. , Li C. , Pilgrim N. J. , Holland M. C. , Dunn G. M. , Cumming D. R. S. 
Published: December 2010

AbstractContacts to planar Gunn devices on the semiconductor surface suffer from high electric field stress and current crowding leading to premature burn out. We have developed a new composite contact design using a Schottky extension of the conventional Ohmic contact. The composite contact structures have been fabricated and tested to mitigate the effects of high concentrations of charge and high electric fields at the anode edge of the planar Gunn diode. Monte Carlo simulations confirm these experimental results in composite contacts. These results suggest a mechanism of increased lifetime when using composite contacts as compared to conventional Ohmic contacts. This is of significant importance for planar Gunn device operation at millimetre wave and terahertz frequencies where high doping density (∼1017cm‐ 3) and short cathode to anode separation (1µm or less) is required. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
HVPE growth of c‐plane AlN on a‐plane sapphire using nitridation layer
Authors: Takagi Yuta , Miyagawa Reina , Miyake Hideto , Hiramatsu Kazumasa 
Published: December 2010

Abstractc‐plane AlN was grown on a‐ and c‐plane sapphire substrates by low‐pressure hydride vapor phase epitaxy with nitridation layer. The a‐plane sapphire was confirmed to be effective for obtaining high‐quality AlN with RMS surface roughness of 0.19 nm for 2 x 2 μm2 image and a large crack‐free thickness of 3.0 μm. The full widths at half maximum of (0002) and (10‐10) ω scans were 311 and 632 arcsec. for AlN on a‐plane sapphire substrate, respectively (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Surface plasmons for improving the performance of quantum dot structures for third generation solar cell applications
Authors: Pillai Supriya , Perez‐Wurfl Ivan , Conibeer Gavin J. , Green Martin A. 
Published: December 2010

AbstractWe use room temperature photoluminescence (PL) measurements to investigate the effect of surface plasmons on the emission from a single layer quantum dot structure. Silver metal nanoparticles are fabricated using self assembly techniques and tailored to provide selective scattering by varying the size of the particles. We report an 8 fold increase in the PL intensity at the peak emission wavelength of the silicon nanocrystals and up to a 15 fold increase in the emission corresponding to the surface plasmon resonance frequency. We attribute this enhnacement to both the scattering in and outcoupling of light by excitation of surface plasmons. The energy transfer from the nanocrystal excitons to surface plasmons and vice versa is tunable and has the potential to increase absorption in the bandgap engineered quantum dot cells for third generation photovoltaic (PV) applications such as tandem solar cells and hot‐carrier cells. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced dynamics of the multi‐orbital Hubbard model
Authors: Maeshima Nobuya , Hino Ken‐ichi , Yonemitsu Kenji 
Published: December 2010

AbstractWe investigate photoinduced dynamical properties of the one‐dimensional two‐orbital degenerate Hubbard model by calculating the time‐dependent many‐electron wave function. The transient optical response spectra around the charge‐transferpeak show characteristic coherent oscillations, which can be attributed to the Raman‐active orbital excitations (orbitons). An analysis for the oscillating component shows that the photoinduced oscillations are caused by the quantum interference between photogenerated states. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitation power dependence of nonlinear optical response of excitons in GaAs/AlAs superlattices
Authors: Yamashita Takae , Kojima Osamu , Kita Takashi , Akahane Kouichi 
Published: December 2010

AbstractWe studied effects of the miniband structure to control the nonlinear optical response of excitons in GaAs/AlAs superlattices. The excitation‐power dependence of the degenerate four‐wave‐mixing signal shows different saturation power in the samples with the thinner and thicker barriers, while the dependence of dephasing time is almost independent of the barrier width. The analysis of the excitation‐power dependence of the photoluminescence spectrum indicates the biexciton generation at lower excitation power in the sample with the thicker barrier width. These results demonstrate that the saturation of the four‐wave‐mixing signal intensity of the exciton comes from the contribution of the biexcitons. Our results support a possibility that the nonlinear optical response of excitons can be controlled by controlling the barrier width. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ground state of electron‐hole bilayer with density imbalance
Authors: Yamashita Kazuo , Asano Kenichi , Ohashi Takuma 
Published: December 2010

AbstractWe study electron‐hole bilayer system with density imbalance at zero temperature. By means of the mean‐field theory, we derive phase diagram and find that the FuldeFerrell state exists in vast areas of high density regions.We clarify that the system with long‐range interaction is fairly efficient for the realization of the Fulde‐Ferrell state due to the order parameter mixing effect. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photogenerated carriers in Si‐related random composites
Authors: Itoh Takashi 
Published: December 2010

AbstractBehaviors of photogenerated carriers in Si‐related random composites, hydrogenated microcrystalline silicon (μc‐Si:H) and hydrogenated amorphous silicon (a‐Si:H) have been discussed. In μc‐Si:H film, the γ ‐value changes from 0.82 to around 1 with decreasing the temperature from 300 K to 180 K. In a‐Si:H film, the gradual increase in the γ ‐value due to the photo‐degradation. In a‐Si:H thin film solar cell, the γ‐value of 0.95 is obtained from the light intensity dependence of photoconductivity. The discussions have been focused on recombination processes through the γ ‐value in μc‐Si:H and a‐Si:H films, and also in a‐Si:H thin film solar cell. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High vertical breakdown strength in with low specific on‐resistance AlGaN/AlN/GaN HEMTs on silicon
Authors: Arulkumaran S. , Vicknesh S. , Ng G. I. , Liu Z. H. , Selvaraj S. L. , Egawa T. 
Published: December 2010

AbstractOff‐state and vertical breakdown characteristics of AlGaN/AlN/GaN high‐electron‐mobility transistors (HEMTs) on high‐resistivity (HR)‐Si substrate were investigated and analysed. Three‐terminal off‐state breakdown (BVgd) was measured as a function of gate–drain spacing (Lgd). The saturation of BVgdwithLgdis because of increased gate leakage current. HEMTs withLgd= 6 µm exhibited a specific on‐resistanceRDS[ON]of 0.45 mΩ cm2. The figure of merit (FOM = BVgd2/RDS[ON]) is as high as 2.0 × 108V2Ω–1cm–2, the highest among the reported values for GaN HEMTs on Si substrate. A vertical breakdown of ∼1000 V was observed on 1.2 µm thick buffer GaN/AlN grown on Si substrate. The occurrence of high breakdown voltage is due to the high quality of GaN/AlN buffer layers on Si substrate with reduced threading dislocations which has been confirmed by transmission electron microscopy (TEM). This indicates that the AlGaN/AlN/GaN HEMT with 1.2 µm thick GaN/AlN buffer on Si substrate is promising candidate for high‐power and high‐speed switching device applications. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)