bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prognostic factors of Epstein–Barr virus‐associated hemophagocytic lymphohistiocytosis in children: Report of the Japan Histiocytosis Study Group
Authors: Kogawa Kazuhiro , Sato Hiroki , Asano Takeshi , Ohga Shouichi , Kudo Kazuko , Morimoto Akira , Ohta Shigeru , Wakiguchi Hiroshi , Kanegane Hirokazu , Oda Megumi , Ishii Eiichi 
Published: February 2014

BackgroundDespite several advances in the treatment of Epstein–Barr virus (EBV) in recent years, patients with Epstein–Barr virus‐associated hemophagocytic lymphohistiocytosis (EBV‐HLH) do not always show satisfactory outcomes. We here conducted a nationwide survey in Japan to identify prognostic factors of EBV‐HLH in children with this disease in an effort to improve the management and the outcomes of these patients.ProcedureBetween January 2003 and June 2008, we enrolled 98 children younger than 18 years of age who were diagnosed with EBV‐HLH. We then studied the clinical characteristics and laboratory findings at the time of diagnosis with the aim to identify prognostic factors for EBV‐HLH.ResultsThe mean age of onset of EBV‐HLH was 3.9 ± 2.8 years. Most of our patients presented with fever, hepatosplenomegaly, lymphadenopathy, and hemophagocytosis of bone marrow. Sixty‐two percent of patients showed T cell clonality, and 97% had EBV infection in either T or natural killer cells. Most patients (60%) were treated with a multi‐agent chemotherapeutic regimen, including corticosteroid, etoposide, and cyclosporine. After initial treatment, 90.3% of patients were in remission, and 7 patients (8.2%) experienced recurrence of EBV infection. Among several prognostic factors, patients with both hyperbilirubinemia (>1.8 mg/dl) and hyperferritinemia (>20,300 ng/ml) at the time of diagnosis had significantly poorer outcomes than those with low serum bilirubin and ferritin levels.ConclusionsThese findings suggest that the therapeutic strategy for children with EBV‐HLH could be tailored according to the laboratory findings at diagnosis. Pediatr Blood Cancer 2014;61:1257–1262. © 2014 Wiley Periodicals, Inc.
Transposition of the great arteries: factors influencing prenatal diagnosis
Authors: Bertagna F. , Rakza T. , Vaksmann G. , Ramdane‐Sebbane N. , Devisme L. , Storme L. , Francart C. , Vaast P. , Houfflin‐Debarge V. 
Published: February 2014

ABSTRACTObjectiveThe objective of this study is to highlight the factors that may affect prenatal diagnosis of transposition of the great arteries (TGA) in order to improve it.MethodsThis is a retrospective study performed between 2004 and 2009 in the maternity units from North of France. We identified a total of 68 cases of TGA (isolated or associated with only VSD or coarctation of aorta), of which 32 (47.1%) had prenatal diagnosis (PND+) and 36 did not (PND−). Maternal characteristics and ultrasound factors were studied in relation to PND.ResultsMaternal weight and body mass index were significantly higher in the PND− group (70.4 kg and 26.5 kg/m2 vs 63.6 kg and 23.6 kg/m2, respectively). Maternal obesity (body mass index >30) was significantly more frequent in the PND− group (27.8% vs 12.5%). More than a quarter of TGA (28.1%) were diagnosed during the third trimester.ConclusionObesity is the main cause of missed PND of TGA. Obese patients with suboptimal prenatal scans may benefit from reassessment of fetal cardiac anatomy and/or from referral for fetal echocardiography. © 2014 John Wiley & Sons, Ltd.
Highly conductive p  + + ‐AlGaAs/n  + + ‐GaInP tunnel junctions for ultra‐high concentrator solar cells
Authors: Barrigón Enrique , García Ivan , Barrutia Laura , Rey‐Stolle Ignacio , Algora Carlos 
Published: February 2014

AbstractTunnel junctions are key for developing multijunction solar cells (MJSC) for ultra‐high concentration applications. We have developed a highly conductive, high bandgap p  + + ‐AlGaAs/n  + + ‐GaInP tunnel junction with a peak tunneling current density for as‐grown and thermal annealed devices of 996 A/cm 2 and 235 A/cm 2, respectively. The J–V characteristics of the tunnel junction after thermal annealing, together with its behavior at MJSCs typical operation temperatures, indicate that this tunnel junction is a suitable candidate for ultra‐high concentrator MJSC designs. The benefits of the optical transparency are also assessed for a lattice‐matched GaInP/GaInAs/Ge triple junction solar cell, yielding a current density increase in the middle cell of 0.506 mA/cm 2 with respect to previous designs. Copyright © 2014 John Wiley & Sons, Ltd.
Novel alkoxyanthracene donor and benzothiadiazole acceptor for organic thin film transistor and bulk heterojunction organic photovoltaic cells
Authors: Ma Jae Yeol , Yun Hui‐Jun , Kim Seul‐Ong , Lee Gi Back , Cha Hyojung , Park Chan Eon , Kwon Soon‐Ki , Kim Yun‐Hi 
Published: February 2014

ABSTRACTNovel alkoxy anthracene (ODA)‐based polymeric semiconductors were designed for polymer solar cell applications. Alkoxyanthracene, which contains many π electrons and electron donating group, was easily synthesized. The copolymers, poly(alkoxy anthracene‐alt‐thiophene benzothiadiazole thiophene) poly(ODA‐TBT) and poly(alkoxy anthracene‐alt‐benzothiadiazole) poly(ODA‐BT), have been obtained by Suzuki coupling polymerization. Both polymers have ODA unit as a donor and benzothiadiazole as an acceptor. ODA‐TBT has thiophene linkages between ODA and benzothiadiazole. The optical, thermal, and electrochemical properties have been investigated by UV–visible absorption, thermal gravimetric analysis, differential scanning calorimetry, and CV. Organic thin‐film transistor using polymers showed that the hole mobility of poly(ODA‐alt‐TBT) was around 3.6 × 10−3 cm2/Vs with on/off ratio of 9.91 × 105 while that of poly(ODA‐alt‐BT) was around 1.21 × 10−2 cm2/Vs with on/off ratio of 2.64 × 106. Organic photovoltaic performance based on polymers were evaluated with a configuration of ITO/PEDOT:PSS/active layer/LiF/Al. Poly(ODA‐TBT) exhibits a short circuit current (Jsc) of 3.9 mA/cm2 and power conversion efficiency (PCE) of 1.4%, and poly(ODA‐BT) exhibits the Jsc of 6.4 mA/cm2 and PCE of 2.2%. The better device performance of poly(ODA‐BT) is attributed to its charge transfer ability and enhanced mobility and crystallinity although poly(ODA‐BT) does not have extended π‐conjugation due to twisted structure compared with poly(ODA‐TBT). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1306–1314
Living and stereoselective polymerization of rac‐lactide by bimetallic aluminum Schiff‐Base complexes
Authors: Qu Zhi , Duan Ranlong , Pang Xuan , Gao Bo , Li Xiang , Tang Zhaohui , Wang Xianhong , Chen Xuesi 
Published: February 2014

ABSTRACTA series of bimetallic aluminum Schiff‐base complexes have been prepared and characterized. The complexes used as catalysts were applied in the lactide polymerization to test their activities and stereoselectivities. All polymerizations are living, as evidenced by the narrow polydispersities and the good fit between calculated and found number‐average molecular weights of the isolated polymers. Isotactic enriched polylactide was obtained by using these complexes. Kinetic studies indicated that the polymerizations are both first‐ordered with respect to lactide monomer and catalyst. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1344–1352
Self‐consistent field theory investigation of directed self‐assembly in cylindrical confinement
Authors: Laachi Nabil , Delaney Kris T. , Kim Bongkeun , Hur Su‐Mi , Bristol Robert , Shykind David , Weinheimer Corey J. , Fredrickson Glenn H. 
Published: February 2014

ABSTRACTWe use self‐consistent field theory to study the self‐assembly of cylinder‐forming diblock copolymers confined in a cylindrical prepattern. This situation arises in contact holes—the hole shrink problem—where the goal is to produce a cylindrical hole with reduced dimensions relative to a guiding prepattern. In this study, we focus on systems with a critical prepattern dimension ranging from 50 nm to 100 nm that consequently lead to the formation of a single cylinder in the middle of the hole. We find that a variety of defect morphologies arise from the self‐assembly process and are strongly governed by the prepattern dimensions, wetting conditions as well as the polymer molecular weight. We also consider blends of diblock copolymers and homopolymers and determine optimal blending configurations that not only favor the formation of the desired cylindrical morphology but also extend the processing window relative to the pure diblock case. When defective structures form inside the prepattern, we compute their formation energy and use the string method to examine the kinetic pathways for the transition from the defective state to the perfect cylindrical state. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 142–153
Multilayer films composed of conductive poly(3‐hydroxybutyrate)/carbon nanotubes bionanocomposites and a photoresponsive conducting polymer
Authors: Valentini Luca , Fabbri Paola , Messori Massimo , Degli Esposti Micaela , Bittolo Bon Silvia 
Published: February 2014

ABSTRACTIn order to develop new electronic devices, it is necessary to find innovative solutions to the eco‐sustainability problem of materials as substrates for circuits. We realized a photoresponsive device consisting of a semiconducting polymer film deposited onto optically semitransparent and conductive biodegradable poly(3‐hydroxybutyrate) (PHB)/carbon nanotube (CNT) substrates. The experiments indicated that the PHB‐CNT bionanocomposite substrate behaves as an optical window trapping electric charges produced by the photoexcitation of the semiconducting polymer. Such PHB‐CNT functional substrates are expected to be attractive for eco‐friendly electronics. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 596–602
Characterising Runoff Generation Processes in a Lake‐Rich Thermokarst Landscape (Old Crow Flats, Yukon, Canada) using δ18O, δ2H and d‐excess Measurements
Authors: Turner Kevin W. , Edwards Thomas W. D. , Wolfe Brent B. 
Published: February 2014

ABSTRACTApplication of novel hydrological methods for assessing runoff generation in remote northern landscapes is necessary to identify the consequences of climate variability and change. In Old Crow Flats, a lake‐rich thermokarst landscape in northern Yukon Territory (Canada), local land users have concerns over the effects of recent lake drainage and fluctuating river discharge on their traditional way of life. In the absence of hydrometric stations, we evaluate the utility of isotopic monitoring of the lower Old Crow River, which is fed by several tributaries and drains the flats, for tracking runoff generation. Isotopic ‘snapshots’ obtained from 2007, 2008 and 2009 during the recession limb of the spring freshet hydrograph provided characteristic patterns of deuterium excess (d‐excess) along the Old Crow River. River sampling in June 2007 captured a pulse of evaporatively enriched lake water originating from a rainfall‐triggered catastrophic lake drainage event, identified by decreased d‐excess values. June 2008 was marked by negligible variability in d‐excess values along the same reach of the river, consistent with minimal export of lake waters after a winter of below‐normal snow accumulation. In contrast, rising d‐excess values along the study reach in June 2009 indicate enhanced rainfall‐generated runoff. River isotope sampling could be used to monitor spatial and temporal variability in runoff generation processes in the Old Crow Flats and other northern lake‐rich landscapes drained by rivers. Copyright © 2014 John Wiley & Sons, Ltd.
Cystic Fibrosis Database (CFDB): A new web‐based tool for cystic fibrosis specialists
Authors: Buzzetti Roberto , Cirilli Natalia , Minicucci Laura , Raia Valeria , Salvatore Donatello , Maffeis Paolo 
Published: February 2014

SummaryIn order to help specialists involved in CF care and clinical research to know the current best evidence about clinical effectiveness of interventions in CF, we designed and developed a web‐based, free access tool called “CFDB”—Cystic Fibrosis DataBase (www.inetflow.it/CFDB). The database was built by searching in Medline, Embase, Cochrane Library and worldwide trials registries all studies involving clinical interventions in CF. The tool lets the user define queries starting from one or more types of pathological conditions and one or more interventions. The output of the queries is structured in three levels: (1) how many and which studies deal with the conditions formulated in the query; (2) which are the main results of these studies; (3) a critical summary of the literature related to the query. This tool, providing a quick overview of the available evidence in clinical research in CF, may help clinical decision making, designing of new trials and building guidelines. Pediatr Pulmonol. 2014; 49:938–940. © 2014 Wiley Periodicals, Inc.
The bronchodilator response as a predictor of inhaled corticosteroid responsiveness in asthmatic children with normal baseline spirometry
Authors: Galant Stanley P. , Morphew Tricia , Guijon Olga , Pham Linh 
Published: February 2014

SummaryRationaleAlthough inhaled corticosteroids (ICS) are considered first line controller therapy in children with persistent asthma, heterogeneity of the ICS response can be an important clinical problem. The purpose of this study is to determine the value of the bronchodilator response (BDR) in identifying the ICS responder and establish the optimal BDR cut‐point that could be particularly useful in the clinic setting when baseline spirometry is normal.MethodsMexican American asthmatic children, 5–18 years, with normal baseline spirometry who required low dose (step 2), or medium dose (step 3) ICS therapy were evaluated by skin prick test for atopy, and pre‐ and post‐bronchodilator spirometry. ICS responders were defined by a ≥7.5% improvement in the FEV1 following 4–6 weeks of therapy. The optimal cut‐point was determined by Receiver Operator Characteristic (ROC) curves as the best balance between sensitivity and specificity.ResultsThere were 34.8% of the 132 study patients who were ICS responders. ROC curves showed the BDR ≥10% to be an optimal cut‐point with sensitivity 46%, specificity 76%, positive predictive value (PPV) 50%, and negative predictive value (NPV) 72%. Atopic females with a BDR ≥10% had a PPV of 73%.ConclusionsThe composite phenotype of female gender, atopic, and the BDR of ≥10% identified 73% as ICS responders compared to 50% in our overall population with a BDR of ≥10% alone, with minimal false positives. We suggest that the BDR in conjunction with gender and atopic status be considered as potentially useful predictors of the ICS responder, particularly when baseline spirometry is normal. Pediatr Pulmonol. 2014; 49:1162–1169. © 2014 Wiley Periodicals, Inc.
Self‐aligned gate‐last enhancement‐ and depletion‐mode AlN/GaN MOSHEMTs on Si
Authors: Huang Tongde , Ma Jun , Lu Xing , Liu Zhao Jun , Zhu Xueliang , Lau Kei May 
Published: February 2014

AbstractThis paper demonstrates the fabrication of self‐aligned gate‐last enhancement‐ and depletion‐mode (E/D‐mode) AlN/GaN metal‐oxide‐semiconductor high‐electron‐mobility‐transistors (MOSHEMTs). In addition, the effects of annealing on threshold voltage (Vth) are analyzed. The E and D‐mode transistors were fabricated with Ni/Au and Ti/Au as the gate metal, respectively. The Ni/Au gated MOSHEMTs show Vth = +0.3 V after post‐gate metallization annealing, and the Ti/Au gated MOSHEMTs without annealing show Vth= ‐1.8 V. In the E‐mode (Ni/Au gated) transistors, the Vth shift after post‐gate annealing is due to the decrease of fixed charges at the Al2O3/GaN interface. An investigation has been conducted for the understanding of the Vth shift, which is crucial for improving the transistors' stability in various applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐efficiency blue and green LEDs grown on Si with 5 micrometer thick GaN buffer
Authors: Zou Xinbo , Wong Ka Ming , Chong Wing Cheung , Ma Jun , Lau Kei May 
Published: February 2014

AbstractHigh‐efficiency blue and green light‐emitting diodes (LEDs) were grown on planar Si substrates using a 5 µm thick GaN buffer by metalorganic chemical vapor deposition (MOCVD). AlN/GaN superlattices (SLs)–based interlayers were inserted twice for stress balancing and dislocation reduction. Smooth surface and low dislocation density of 1 × 109 cm–2 were achieved. The light output power (LOP) of bare 300 × 300 µm2 447 nm–LEDs and 510 nm–LEDs on Si was measured to be 2.15 mW and 0.85 mW at 20 mA, respectively. At –15 V, leakage current of as low as 3 µA was achieved for 447 nm–LEDs while higher leakage current was measured for green LEDs. After Si substrate removal, the LOP of packaged 440 nm– and 500 nm–LEDs reached 8.50 mW and 4.85 mW at 20 mA, respectively. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of semipolar {11$ \bar 2 $2} light‐emitting diodes using a hole blocking layer
Authors: Nakao Kota , Haziq Muhammad , Okamura Yasumasa , Yamane Keisuke , Okada Narihito , Tadatomo Kazuyuki 
Published: February 2014

AbstractIn this study, we fabricated {11$ \bar 2 $2} light‐emitting diodes (LEDs) using a single quantum well (SQW) and hole blocking layer (HBL) with various Al compositions and investigated the effect of the HBL on the characteristics of the LED. The electroluminescence (EL) intensity increased with an increase of the Al composition of the HBL. Furthermore, the EL intensity increased by a factor of six when the Al composition of the HBL increased by 25%. The forward voltages of the LEDs with the HBLwere approximately 3 V regardless of the Al composition of the HBL. The prevention of hole overflow using the HBL is demonstrated by the injection current dependence of the EL intensity and the blueshift by comparing the SQW LEDs with the HBLs with the SQW LEDs without the HBL and a multiple quantum well LED. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Non‐polar (11$ \bar 2 $0) InGaN quantum dots with short exciton lifetimes grown by metal‐organic vapour phase epitaxy
Authors: Emery Robert M. , Zhu Tongtong , Oehler Fabrice , Reid Benjamin , Taylor Robert A. , Kappers Menno J. , Oliver Rachel A. 
Published: February 2014

AbstractInGaN quantum dot (QD) structures have been grown by metal organic vapour phase epitaxy (MOVPE) on non‐polar (11‐20) GaN surfaces by employing an anneal step in nitrogen immediately after the growth of the InGaN. Here, we compare the growth of such structures on pseudo‐substrates grown using an epitaxial lateral overgrowth (ELOG) technique and on pseudo‐substrates grown using a simpler in situ SiNx interlayer. The less complex defect reduction approach results in a significantly higher defect density, but does not detrimentally effect the QD formation. For both types of pseudo‐substrate, sharp peaks with resolution limited widths are observed in both cathodoluminescence at 9 K and micro‐photoluminescence at 4.2 K. The QDs demonstrate significantly reduced exciton lifetimes compared to structures grown on c‐plane, which has advantages for possible applications in single photon sources. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN tubes with coaxial non‐ and semipolar GaInN quantum wells
Authors: Heinz Dominik , Fikry Mohamed , Aschenbrenner Timo , Schowalter Marco , Meisch Tobias , Madel Manfred , Huber Florian , Hocker Matthias , Frey Manuel , Tischer Ingo , Neuschl Benjamin , Mehrtens Thorsten , Müller Knut , Rosenauer Andreas , Hommel Detlef , Thonke Klaus , Scholz Ferdinand 
Published: February 2014

AbstractWe present the position‐controlled growth of GaN nanotubes with coaxial GaInN quantum wells by using ZnO nanowires grown on top of GaN pyramids as templates. High resolution scanning transmission electron microscopy allows us to perform a detailed structural analysis of individual tubes. In particular, we report about structural properties like indium incorporation, thickness, and homogeneity of quantum wells realized on nonpolar m‐plane side facets or on semipolar tips. Additionally, high resolution spatially and spectrally resolved cathodoluminescence spectroscopy performed at low temperature enables us to clearly identify the quantum well luminescence contributions for different kinds of facets on a single tube. The luminescence of the quantum wells deposited at variable temperatures shows a clear spectral shift in the cathodoluminescence signal, yielding an activation energy for the indium desorption from the m‐plane side facets of about 1.6 eV. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GaN‐on‐Si wafers for HEMTs with high power‐driving capability
Authors: Hu Cheng‐Yu , Murad Saad , Nishikawa Atsushi , Groh Lars , Pinos Andrea , Tan Weisin , Chitnis Ashay , Sizov Victor , Yagi Takuma , Lutgen Stephan 
Published: February 2014

AbstractBy means of our patented strain engineering technology, we achieved high crystal quality and near zero wafer bow on our 150 mm GaN‐on‐Si wafers. To show the feasibility of our wafers for HEMTs with large gate periphery, we investigated the buffer breakdown(VBR) yield on device test structures with different periphery. To reduce the processing complexity, we used comb‐shaped structures with only source and drain contacts and N+ implant isolation in between the contacts. The VBR was defined at buffer leakage of 1 µA/mm. For a typical source‐drain distance of 14 µm, the VBR yield specification is 600 V. Then we demonstrated over 80% VBR yield for 100 mm device test structures on our 150 mm GaN‐on‐Si wafers. This high yield for large periphery test structures shows that our 150 mm GaN‐on‐Si wafers are very suitable for fabricating large HEMT devices. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of thermoelectric properties of GaN and ZnO samples
Authors: Kucukgok B. , Wang B. , Melton A. G. , Lu N. , Ferguson I. T. 
Published: February 2014

AbstractIn this paper, room temperature thermoelectric (TE) properties of wide bandgap thin film GaN and bulk ZnO are studied. Bulk GaN is also incorporated with epitaxy films to make comparison. GaN and ZnO materials have superior electrical performance and chemical stability at high temperatures and are currently found in many commercial applications, such as, photovoltaic, solid‐state lighting, and gas sensors. Since there are not many semiconductor materials that can operate effectively at high temperatures, wide bandgap materials like GaN and ZnO would be a promising solution for high temperatures thermoelectric power generation. In order to understand their TE properties, we systematically compared and characterized TE behaviour of GaN and ZnO thin films with a function of doping concentrations. The common trend of a decrease in Seebeck coefficients with the increase of carrier concentration for thin film and bulk GaN is observed, however, reverse TE trend for bulk ZnO, were observed. The most commonly observed TE trend is attributed to Mott‐Jones relation to simple transport models while inverse trend could be suggested as hopping conductance. Moreover, the Seebeck coefficients of ZnO samples are found to be larger than those of thin film and bulk GaN samples in the similar carrier density. Highest power factors, 2.6×10–4 W/mK2and 0.65×10–4 W/mK2, and Seebeck coefficients, 478 µV/K and 481 μV/K were measured for thin film GaN and bulk ZnO, respectively. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)