bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of quinestrol and levonorgestrel on populations of plateau pikas, Ochotona curzoniae, in the Qinghai‐Tibetan Plateau
Authors: Liu Ming , Qu Jiapeng , Yang Min , Wang Zengli , Wang Yanling , Zhang Yanming , Zhang Zhibin 
Published: January 2012

AbstractBACKGROUND: Plateau pikas (Ochotona curzoniae, Hodgson, 1858) are viewed as a pest in the Tibetan Plateau meadow ecosystem when their population densities are high. Traditional culling using rodenticides often poses a high risk to non‐target species and even to humans. In this study, an investigation was made of the infertility effects of quinestrol (E), levonorgestrel (P) and a combination of the two (EP, ratio E:P = 1:2) on plateau pikas during 2007 and 2008.RESULTS: Treatment with E or EP significantly decreased the pregnancy rate of female pikas in 2007. In 2008, there was a cross‐year effect that still suppressed male reproduction in treated groups. Treatment with E obviously reduced the reproduction of pikas but not their population abundance in 2007; the reduction in population size was significant in 2008.CONCLUSIONS: Single baiting of quinestrol in early breeding season reduced the reproduction and population size of pikas throughout 2007. The effect of infertility lasted into the next breeding season through a cross‐year effect, which resulted in a significant reduction of population size in 2008. Quinestrol is a very promising non‐lethal approach to managing pika populations; however, several factors need to be investigated further to improve the practicality of this method. Copyright © 2012 Society of Chemical Industry
Enhanced light output power of green LEDs employing AlGaN interlayer in InGaN/GaN MQW structure on sapphire (0001) substrate
Authors: Shioda Tomonari , Yoshida Hisashi , Tachibana Koichi , Sugiyama Naoharu , Nunoue Shinya 
Published: January 2012

AbstractIn order to enhance light output power of green light‐emitting diodes (LEDs) on a sapphire (0001) substrate, we employ 1.5 nm‐thick AlGaN interlayer between an InGaN well layer and an upper GaN barrier layer. AlGaN interlayer controls asymmetric band profile due to piezoelectric field, and thus it controls the quantum‐confined Stark effect. Although both photoluminescence intensity and electroluminescence intensity of a conventional MQW decreases drastically as the emission wavelength becomes longer, the intensity drop at spectral range of 530–580 nm is suppressed by utilizing an AlGaN interlayer. The maximum light output power of 12 mW at 532 nm and external quantum efficiency of 25.4% have been achieved for the LED employing Al0.30Ga0.70N interlayer at a driving current of 20 mA. This result indicates that the band‐engineering approach is effective for an IQE enhancement at pure green or longer wavelength, even if a polar (0001) face is utilized.
GaN‐based high‐frequency devices and circuits: A Fraunhofer perspective
Authors: Waltereit Patrick , Bronner Wolfgang , Quay Rüdiger , Dammann Michael , Cäsar Markus , Müller Stefan , van Raay Friedbert , Kiefer Rudolf , Brückner Peter , Kühn Jutta , Musser Markus , Kirste Lutz , Haupt Christian , Pletschen Wilfried , Lim Taek , Aidam Rolf , Mikulla Michael , Ambacher Oliver 
Published: January 2012

AbstractWe present the current status of our technology for GaN‐based HEMTs and MMICs as well as results ranging from the L‐band up to the W‐band. Epitaxial growth is carried out on 4H‐SiC(0001) substrates by both MOCVD and MBE. Processing is done using standard III–V equipment including both frontside and backside processing. For L‐band power bars we arrive at output powers, efficiencies and gains beyond 100 W, 60% and 17 dB, all measured under cw conditions at 50 V drain bias. The X‐band MMICs are characterized by a high efficiency above 40% for two‐stage amplifiers. Towards mm‐wave applications we have fabricated HEMTs with transit frequencies above 100 GHz and W‐band MMICs delivering 0.5 W/mm at 94 GHz with 7% PAE. First quaternary InAlGaN barriers show promising results for this new materials system. Reliability tests return a very good long‐term stability of our devices even at an elevated channel temperature of 200 °C with an extrapolated lifetime of 5 × 105. Initial space capability tests including total ion dose radiation insensitivity, radiation displacement damage, hydrogen poisoning and single event effect are successfully passed.
Large polycyclic aromatic hydrocarbons for application in donor–acceptor photovoltaics
Authors: Hesse Holger Christian , Schaffer Christoph , Hundschell Christian , Narita Akimitsu , Feng Xinliang , Müllen Klaus , Nickel Bert , Schmidt‐Mende Lukas 
Published: January 2012

AbstractWe present the photovoltaic application of a donor–acceptor system consisting of very large polycyclic aromatic hydrocarbons. Using vacuum sublimated hexa‐peri‐hexabenzocoronenes we evidence long exciton diffusion lengths of approximately 25 nm. In conjunction with the heaxfluorinated analogue for the first time a photovoltaic device using nanographene as active material for both donor and acceptor compounds was fabricated. The bi‐layered device exhibits a remarkably high open circuit voltage of 1.39 V. Light absorption of the photoactive materials used here is strictly confined to wavelengths below 500 nm, rendering this approach especially interesting for the application in semi‐transparent devices as well as multi‐layered and tandem solar cells.magnified image
The photovoltaic performance of devices based on vacuum sublimated hexa‐peri‐hexabenzocoronenes is shown.
Dependence of magnetization on cation distributions in the spinel ferrites Cu1 − xZnxFe2O4(0.0 ≤ x ≤ 1.0)
Authors: Han Q. J. , Ji D. H. , Tang G. D. , Li Z. Z. , Hou X. , Qi W. H. , Bian R. R. , Liu S. R. 
Published: January 2012

AbstractFerrite samples of the composition Cu1 − xZnxFe2O4(0.0 ≤ x ≤ 1.0) were synthesized by chemical coprecipitation. The samples exhibited a single‐phase cubic spinel structure and the saturation magnetization of the samples was found to increase with increasing Zn content, whenx ≤ 0.4; and then decreased with increasingx. The dependence of magnetization on cation distributions in the ferrite samples has been estimated using a quantum‐mechanical method proposed by our group. Estimated cation distributions obtained by fitting the magnetic moments of the samples were used to perform Rietveld fitting for X‐ray diffraction patterns. The acceptable error parameters in the Rietveld fitting indicate that the estimated cation distributions in the samples are reasonable.
Dielectric function and bowing parameters of InGaN alloys
Authors: Sakalauskas E. , Tuna Ö. , Kraus A. , Bremers H. , Rossow U. , Giesen C. , Heuken M. , Hangleiter A. , Gobsch G. , Goldhahn R. 
Published: January 2012

AbstractGa‐rich (0001)‐oriented InxGa1−xN alloys grown by molecular beam epitaxy or metal‐organic vapour phase epitaxy on GaN/sapphire templates were investigated by spectroscopic ellipsometry at room temperature. The analysis of the extracted dielectric function yielded the characteristic transition energies, i.e., for the band gaps and the high‐energy critical points (van Hove singularities). Accounting for strain by using the k · p formalism, a band‐gap bowing parameter of 1.65 ± 0.07 eV for strain‐free material was deduced. It is consistent with the ab initio calculated band‐gap‐dependence for uniform (not clustered) InGaN alloys. The bowing parameters for the high‐energy inter‐band transitions were found to be close to ∼1 eV.
Carrier recombination processes in In‐polar and N‐polar p‐type InN films
Authors: Imai Daichi , Ishitani Yoshihiro , Fujiwara Masayuki , Wang Xinqian , Kusakabe Kazuhide , Yoshikawa Akihiko 
Published: January 2012

AbstractRadiative recombination efficiency in InN is lower than the other III nitride binary compounds (GaN, AlN). Particularly, photoluminescence (PL) intensity in p‐InN is weaker than that in n‐InN by three orders or more. We investigate the nonradiative recombination (NR) processes in InN with respect to carrier density, activation energy of NR processes, and carrier scattering rate of the inside bulk region estimated by infrared (IR) measurements, and show that NR centers of p‐InN originate from the same defect species as those of n‐type films. We also compare PL properties of N‐polar and In‐polar samples, and show that NR process is initiated by electron capture by deep levels of accepter nature.
Low‐temperature photoluminescence studies of In‐rich InAlN nanocolumns
Authors: Kamimura Jumpei , Kishino Katsumi , Kikuchi Akihiko 
Published: January 2012

AbstractHigh‐quality Inx Al1–xN (0.71 ≤ xIn ≤ 1.00) nanocolumns (NCs) have been grown on Si(111) substrates by rf‐plasma‐assisted molecular‐beam epitaxy (rf‐MBE). Low‐temperature photoluminescence (LT‐PL) spectra of various In‐rich InAlN NCs were measured at 4 K and single peak PL emissions were observed in the wavelength region from 0.89 µm to 1.79 µm. Temperature‐dependent PL spectra of In0.92Al0.08N NCs were studied and the so‐called “S‐shape” (decrease–increase–decrease) PL peak energy shift was observed with increasing temperature. This shift indicates the carrier localization induced by the In segregation effect and is different from the anomalous blue shift frequently observed in InN films and nanowires with high residual carrier concentra‐ tions. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Highly Size‐ and Shape‐Controlled Synthesis of Silver Nanoparticles via a Templated Tollens Reaction
Authors: Dondi Ruggero , Su Wu , Griffith Gerry A. , Clark Graham , Burley Glenn A. 
Published: January 2012

AbstractA mild, facile one‐step synthetic strategy for the preparation of size‐ and shape‐controlled silver nanoparticles (AgNPs) is presented. The high degree of size‐ and shape‐control of these AgNPs is achieved by the use of triazole sugar ligands scaffolded by a central resorcinol ether core. Both the triazoles and the resorcinol ether core mediate the nucleation, growth, and passivation phases of the preparation of AgNP in the presence of the Tollens reagent as the silver source. Kinetic and 1H NMR titration data is presented describing the nature of the interactions between the Tollens reagent and these ligands.
Predictive Gold Nanocluster Formation Controlled by Metal‐Ligand Complexes
Authors: Pettibone John M. , Hudgens Jeffrey W. 
Published: January 2012

AbstractThe formation of ligand‐protected gold nanoclusters during size‐selective syntheses is seemingly driven by the inherent properties of the protecting ligands, but a general description of the product formation has not been presented. This study uses diphosphine‐protected Au clusters as a model system to examine i) control of metal‐ligand complex distributions in methanol–chloroform solutions, ii) role of solution perturbations, e.g., oxidation, and iii) nanocluster formation through reduction of characterized complex distributions. By selectively reducing complexes and monitoring cluster formation with electrospray ionization mass spectrometry and UV–vis, data show the distribution of complexes can be controlled through ligand exchange, and the reduction of specific complexes produce characteristic ligated gold clusters based on ligand class. Specifically, 1,n‐bis(diphenylphosphino)n‐alkane ligands, Ln, where n = 1 through 6, are classified into two distinct sets. The classes represent ligands that either form mainly [AuLn2]+ (Class I, n = 1–3) or bridged [Au2Ln2]2+ (Class II, n = 4–6) complexes after complete ligand exchange with AuClPPh3. Selectively reducing gold‐phosphine ligand complexes allows mapping of product formation, resulting collectively in a predictive tool for ligated gold cluster production by simply monitoring the initial complex distribution prior to reduction.
Genome-Wide Analysis of N1ICD/RBPJ Targets In Vivo Reveals Direct Transcriptional Regulation of Wnt, SHH, and Hippo Pathway Effectors by Notch1
Authors: Li Yaochen , Hibbs Matthew Aaron , Gard Ashley Lauren , Shylo Natalia Aliakseeuna , Yun Kyuson 
Published: January 2012

Abstract
The Notch pathway plays a pivotal role in regulating cell fate decisions in many stem cell systems. However, the full repertoire of Notch target genes in vivo and the mechanisms through which this pathway activity is integrated with other signaling pathways are largely unknown. Here, we report a transgenic mouse in which the activation of the Notch pathway massively expands the neural stem cell (NSC) pool in a cell context-dependent manner. Using this in vivo system, we identify direct targets of RBPJ/N1ICD in cortical NSCs at a genome-wide level through combined ChIP-Seq and transcriptome analyses. Through a highly conservative analysis of these datasets, we identified 98 genes that are directly regulated by N1ICD/RPBJ in vivo. These include many transcription factors that are known to be critical for NSC self-renewal (Sox2, Pax6, Tlx, and Id4) and the transcriptional effectors of the Wnt, SHH, and Hippo pathways, TCF4, Gli2, Gli3, Yap1, and Tead2. Since little is known about the function of the Hippo-Yap pathway in NSCs, we analyzed Yap1 expression and function in NSCs. We show that Yap1 expression is restricted to the stem cell compartment in the developing forebrain and that its expression is sufficient to rescue Notch pathway inhibition in NSC self-renewal assays. Together, results of this study reveal a previously underappreciated complexity and breadth of Notch1 targets in vivo and show direct interaction between Notch and Hippo-Yap pathways in NSCs.
Disclosure of potential conflicts of interest is found at the end of this article.
Structural Synthon Approach to the Study of Stacking Faults in the Layered Double Hydroxides of Lithium and Aluminum
Authors: Britto Sylvia , Kamath P. Vishnu 
Published: January 2012

AbstractA single layer of the Li‐Al layered double hydroxide (LDH) can be considered to be a structural synthon that can be stacked in a number of ways to give rise to the polytypes of the Li‐Al LDH family. The topotactic imbibition of lithium into gibbsite and bayerite precursors gives rise to crystalline 2H and 1M1 polytypes respectively. In contrast the sample formed through a gel to crystallite route is found to be a 1M1 polytype with stacking disorders whose local symmetry corresponds to the 1M2 polytype. On heating, a solid‐solid 1M1→1H polytype transformation is observed.
Synthese von verbrückend substituierten sekundären Phosphanen sowie deren Reaktionen mit Triisopropylindium
Authors: von Hänisch Carsten , Kracke Andreas 
Published: January 2012

AbstractIn this work we report the synthesis and characterisation of the 1.5‐diphosphanyldiethylether O{C2H4PH(SiiPr3)}2 (2) in which two silyl‐substituted phosphine groups are linked by an ether bridge as well as the compound O(SiiPr2PHEt)2 (3) where two ethyl substitute phosphine groups are connected by a siloxane bridge. In addition, we describe the metalation of 2 and 3 with triisopropylindium. These reactions lead to the compounds [O{C2H4P(SiiPr3)IniPr2}2] (4) and [O{SiiPr2P(Et)IniPr2}2] (5) with In2P2 ring structures.
Four LnIII‐MgII Metal Organic Frameworks Containing Fan‐like Helices and Independent [Mg(H2O)6]2+ Units
Authors: Chang Li‐Mei , Zhao Xia , Gu Zhi‐Gang , Liu Wen‐Jing , Wei Zhi‐Qiang , Liu Ying‐Liang , Mo Hai‐Hong , Yue Shan‐Tang 
Published: January 2012

AbstractFour LnII‐MgII metal organic frameworks, namely {Mg(H2O)6·[MgLn(oda)3]2}·6H2O [Ln = Eu (1), Tb (2), Gd (3), Nd (4); H2oda = 2, 2′‐oxydiacetic acid], were synthesized by self‐assembly reactions under hydrothermal conditions and characterized by single‐crystal X‐ray crystal diffraction, elemental analysis, IR spectroscopy as well as thermal analysis. Single‐crystal analysis shows that all four compounds are isostructural and exhibit three‐dimensional metal organic frameworks constructed by fan‐like helices and isolated [Mg(H2O)6]2+ units. Meanwhile, the solid‐state luminescence properties of compounds 1 and 2 were also investigated.
Hydroxylammonium 5‐Nitriminotetrazolates
Authors: Fischer Niko , Klapötke Thomas M. , Piercey Davin G. , Stierstorfer Jörg 
Published: January 2012

AbstractThe hydroxylammonium salts of monodeprotonated 5‐nitriminotetrazole (4), double deprotonated 5‐nitriminotetrazole (5), 1‐methyl‐5‐nitriminotetrazole (6), and 2‐methyl‐5‐nitraminotetrazole (7) have been prepared in high yield from the corresponding 5‐nitriminotetrazoles as free acids and an aqueous solution of hydroxylamine or the metathesis reactions of hydroxylammonium hydrochloride with the silver salt of the corresponding nitriminotetrazole, respectively. The energetic salts 4–7 were fully characterized by single‐crystal X‐ray diffraction (4–6), NMR spectroscopy, IR‐ and Raman spectroscopy as well as DSC measurements. The sensitivities towards impact, friction and electrical discharge were determined. In addition, several detonation parameters (e.g. heat of explosion, detonation velocity) were computed by the EXPLO5.04 computer code based on calculated (CBS‐4M) heats of formation and X‐ray densities.
On the Rare Earth Metal Bismuthide Oxides RE2BiO2 (RE = Nd, Tb, Dy, Ho)
Authors: Nuss Jürgen , Jansen Martin 
Published: January 2012

AbstractA series of new RE2BiO2 compounds (RE = Nd, Tb, Dy, Ho) has been synthesized from elemental bismuth, REBi, and RE2O3 in all‐solid state reactions in sealed tantalum ampoules at 1770 K. The dark grey metallic compounds adopt the anti‐ThCr2Si2 type of structure (I4/mmm, tI10), according to X‐ray single crystal structure analysis. As a main structural feature, there are PbO analogous slabs, [REO]+, and 44 nets of Bi2– anions, alternately stacked along the c‐axis.
Yeast culture collections of the world: meeting the needs of industrial researchers
Authors: Boundy-Mills Kyria 
Published: January 2012

Abstract
The importance of selecting optimal yeast strains for research or industrial applications is often underestimated. For example, utilizing a strain background that already provides the desired stress tolerance or nutrient utilization profile can eliminate costly strain optimization. Yeast culture collections can provide not only the yeast strains but also data and curator expertise to help narrow the search for the optimal strain. While some collections are known for a broad range of cultures and services, other “boutique” collections can provide a broader selection of strains of certain categories, a surprising amount of characterization data, and assistance in selecting strains. This article provides information on dozens of yeast collections of the world, profiles of selected yeast culture collections, and the services that they provide: e.g., strain preservation for patent or safe deposit purposes, species identification service, training workshops, and consulting on yeast identification and physiology. Utilization of these services can save industrial researchers valuable time and resources.
Update on clinical aspects and treatment of selected vitamin‐responsive disorders II (riboflavin and CoQ10)
Authors: Horvath Rita 
Published: January 2012

AbstractRiboflavin and ubiquinone (Coenzyme Q10, CoQ10) deficiencies are heterogeneous groups of autosomal recessive conditions affecting both children and adults. Riboflavin (vitamin B2)‐derived cofactors are essential for the function of numerous dehydrogenases. Genetic defects of the riboflavin transport have been detected in Brown‐Vialetto‐Van Laere and Fazio‐Londe syndromes (C20orf54), and haploinsufficiency of GPR172B has been proposed in one patient to cause persistent riboflavin deficiency. Mutations in the electron tranferring fravoprotein genes (ETFA/ETFB) and its dehydrogenase (ETFDH) are causative for multiple acyl‐CoA dehydrogenase deficiency. Mutations in ACAD9, encoding the acyl‐CoA dehydrogenase 9 protein were recently reported in mitochondrial disease with respiratory chain complex I deficiency. All these conditions may respond to riboflavin therapy. CoQ10 is a lipid‐soluble component of the cell membranes, where it functions as a mobile electron and proton carrier, but also participates in other cellular processes as a potent antioxidant, and by influencing pyrimidine metabolism. The increasing number of molecular defects in enzymes of the CoQ10 biosynthetic pathways (PDSS1, PDSS2, COQ2, COQ6, COQ9, CABC1/ADCK3) underlies the importance of these conditions. The clinical heterogeneity may reflect blocks at different levels in the complex biosynthetic pathway. Despite the identification of several primary CoQ10 deficiency genes, the number of reported patients is still low, and no true genotype‐phenotype correlations are known which makes the genetic diagnosis still difficult. Additionally to primary CoQ10 deficiencies, where the mutation impairs a protein directly involved in CoQ10 biosynthesis, we can differentiate secondary deficiencies. CoQ10 supplementation may be beneficial in both primary and secondary deficiencies and therefore the early recognition of these diseases is of utmost importance.
Heterozygosity for an in‐frame deletion causes glutaryl‐CoA dehydrogenase deficiency in a patient detected by newborn screening: investigation of the effect of the mutant allele
Authors: Bross Peter , Frederiksen Jane B. , Bie Anne S. , Hansen Jakob , Palmfeldt Johan , Nielsen Marit N. , Duno Morten , Lund Allan M. , Christensen Ernst 
Published: January 2012

AbstractA patient with suspected glutaric aciduria type 1 (GA‐1) was detected by newborn screening. GA‐1 is known as an autosomal recessively inherited disease due to defects in the gene coding for glutaryl‐CoA dehydrogenase (GCDH), a mitochondrial enzyme involved in the catabolism of the amino acids hydroxylysine, lysine and tryptophan. DNA and cDNA sequencing revealed a 18 bp deletion (c.553_570del18) resulting in deletion of six amino acids (p.Gly185_Ser190del) in one allele and no sequence changes in the other allele. Confirmatory biochemical analysis of blood, urine and cultured fibroblasts from the proband were consistent with a mild biochemical GA‐1 phenotype. Recombinant expression of the mutant variant in E. coli showed that the GCDH‐(p.Gly185_Ser190del) protein displayed severely decreased assembly into tetramers and enzyme activity. To discover a potential dominant negative effect of the mutant protein, we engineered a prokaryotic expression system in which expression of a wild type and a mutant GCDH allele is controlled by separately inducible promoters. These cells displayed decreased levels of GCDH tetramer and enzyme activity when expressing both the wild type and the mutant GCDH variant protein compared to the situation when only the wild type allele was expressed. Further experiments suggest that the major impact of the GCDH‐(p.Gly185_Ser190del) protein in heterozygous cells consists of hampering the assembly of wild type GCDH into tetramers. Our experimental data are consistent with the hypothesis that heterozygosity for this mutation confers a dominant negative effect resulting in a GCDH enzyme activity that is significantly lower than the expected 50%.