bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nano‐ice on Boron Nitride Nanomesh: Accessing Proton Disorder
Authors: Ma Haifeng , Brugger Thomas , Berner Simon , Ding Yun , Iannuzzi Marcella , Hutter Jürg , Osterwalder Jürg , Greber Thomas 
Published: December 2009

AbstractWater was investigated on a h‐BN/Rh(111) nanomesh template using variable temperature scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. Below 52 K, two distinct phases self‐assemble within the 3.2 nm unit cell of the nanomesh that consists of “holes” and “wires”. In the 2 nm holes, an ordered phase of nano‐ice crystals with about 40 molecules is found. The ice crystals arrange in a bilayer honeycomb lattice, where hydrogen atoms of the lower layer point to the substrate. The phase on the 1 nm wires is a low density gas phase. Tunneling barrier height dI/dz spectroscopy measurements reveal the dipoles of individual molecules in the nano‐ice clusters and access proton disorder.
Structural distortions of semiconducting silicon crystals caused by constant electric field
Authors: Aboyan A. O. , Aghbalyan S. G. 
Published: December 2009

AbstractStructural distortions in nonpolar, particularly, in semiconducting silicon crystals, caused by constant electric field have been disclosed by means of X‐ray interferometry. It was shown that in the field both the direction of moiré fringes and the frequency (period) are changed, and the moiré patterns disappear at values of potential difference in excess of 1.5 kV. The moiré pattern obtained under the action of electrostatic field is independent of the direction (polarity) of the field, the pictures for both the polarities being completely identical. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Deposition of Niobium Nitride Thin Films from Tert‐Butylamido‐Tris‐(Diethylamido)‐Niobium by a Modified Industrial MOCVD Reactor
Authors: Thiede Tobias B. , Parala Harish , Reuter Knud , Passing Gerd , Kirchmeyer Stephan , Hinz Jörn , Lemberger Martin , Bauer Anton J. , Barreca Davide , Gasparotto Alberto , Fischer Roland A. 
Published: December 2009

AbstractNiobium nitride thin films are deposited on 2″ silicon (100) wafers using a modified industrial metal‐organic (MO) CVD reactor of the type AIX‐200RF, starting from tert‐butylamido‐tris‐(diethylamido)‐niobium (TBTDEN) and ammonia. Films of thicknesses 50‐200 nm are deposited at temperatures ranging from 400 °C to 800 °C under reactor pressures of 1 and 5 mbar using various ammonia flow rates, and are characterized by the use of complementary techniques, namely X‐ray diffraction (XRD), scanning electron microscopy (SEM), secondary neutral mass spectrometry (SNMS), Rutherford backscattering spectrometry (RBS), X‐ray photoelectron spectroscopy (XPS), and electrical measurements. Films deposited above 450 °C consist of the cubic δ‐NbN phase, apart from the presence of Nb‐O and Nb‐O‐N species predominantly in the outermost film regions. The lowest specific resistivities, determined by four point probe measurements, are in the range 500–600 µΩ cm. A NbN/SiO2/p‐Si gate stack is fabricated using the grown niobium nitride films. From the capacitance‐voltage (C‐V)‐curves, flat‐band voltages are extracted which, when plotted against SiO2‐insulator thickness, yield a work function of 4.72 eV for as‐deposited films.
Synthesis of Fused 4‐Iodoselenophene[2,3‐b]thiophenes by Electrophilic Cyclization of 3‐Alkynylthiophenes
Authors: Stein André L. , da Rocha Juliana , Menezes Paulo Henrique , Zeni Gilson 
Published: December 2009

AbstractWe present here our results on the electrophilic cyclization reaction of 3‐alkynylthiophenes with different electrophiles such as I2, ICl, and PhSeBr. The cyclization reaction proceeded cleanly under mild reaction conditions, giving fused 4‐iodoselenophene[2,3‐b]thiophenes in excellent yields. In addition, the obtained chalcogenophenes were readily transformed into more complex products through palladium‐ or copper‐catalyzed cross‐coupling reactions with thiols, boronic acids, and organozinc reagents.
Reduction of Alkynyl α‐Hydroxy Esters: Stereoselective α‐Ketol Rearrangement
Authors: Hameury Thomas , Bellosta Véronique , Guillemont Jérôme , Van Hijfte Luc , Cossy Janine 
Published: December 2009

AbstractThe α‐ketol rearrangement of tertiary α‐hydroxy esters induced by LiAlH4/acid treatment provides α‐hydroxy ketones in good yields and high diastereoselectivity. A mechanism is proposed for this reaction as well as a model to explain the diastereoselectivity of the rearrangement.
Aminal–Pyrrolidine Organocatalysts – Highly Efficient and Modular Catalysts for α‐Functionalization of Carbonyl Compounds
Authors: Quintard Adrien , Belot Sébastien , Marchal Estelle , Alexakis Alexandre 
Published: December 2009

AbstractThe substitution of the 4‐position of hydroxyproline by aphenol group, together with an aminal on the 2‐position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the α‐functionalization of a wide range of linear/branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and α‐amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol‐%). As a proof of efficiency, TOFs of up to 1000 h–1 could be obtained.
A framework for the development of STR genotyping in domestic animal species: Characterization and population study of 12 canine X‐chromosome loci
Authors: van Asch Barbara , Pinheiro Raquel , Pereira Rui , Alves Cíntia , Pereira Vânia , Pereira Filipe , Gusmão Leonor , Amorim António 
Published: December 2009

AbstractThis study reports the methodology used to search, select and characterize STR loci on the canine X chromosome using publicly available genome resources and following the current guidelines for human and non‐human forensic testing. After several rounds of selection, 12 X‐STR markers were optimized for simultaneous co‐amplification in a single PCR, and genetic profiles were determined in a sample of 103 unrelated dogs. Mendelian inheritance was verified and mutation rates were assessed using family groups. Alleles that varied in size were sequenced to create a standardized nomenclature proposal based on the number of repeats. All loci conformed to Hardy–Weinberg expectations. The resulting panel showed high forensic efficiency, presenting high values of power of discrimination (in males and females) and mean exclusion chance, both in trios involving female offspring and in duos composed of dam and male offspring. Its use may complement the information obtained by autosomal STR analysis and contribute to the resolution of complex cases of kinship in dogs. The presented methodology for the de novo construction of an STR multiplex may also provide a helpful framework for analogous work in other animal species. As an increasing number of reference genomes become available, convenient tools for individual identification and parentage testing based on STR loci selected from autosomes or sex chromosomes' sequences may be created following this strategy.
Large‐fruited Salicaceae s.l. from the Miocene tuff of the Eichelskopf, northern Hessen, Germany
Authors: Manchester S. R. , Hottenrott M. 
Published: December 2009

AbstractReexamination of Saccoglottis kayseri (Schindehütte) Kirchheimer from the Miocene tuff of the Eichelskopf southeast of Homberg an der Efze in northern Hessen, Germany, indicates that the species was incorrectly attributed to Humiriaceae. The large ovoid fruits are 6‐ and 7‐valved capsules bearing numerous seeds in parietal position. The outer surface is hexagonally or heptagonally ridged. Each valve of the capsule bears a broad, ventral longitudinal band that is densely punctate indicating the position of numerous seeds. These characters point to affinities with the Salicaceae s.l. (incl. most former Flacourtiaceae), and match particularly well with Itoa L., which is distributed today in southern China and eastern Malesia. However, the fruit valves appear to separate only from the apical end, rather than both from base and apex which is a feature of fruits in the Itoa‐Carrierea‐Poliothyrsis group. We treat the fruits as a new genus of Salicaceae, Schindehuettea gen. nov. under the binomial Schindehuettea kayseri (Schindehütte) Manchester. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pollen morphology of Alcea L. and Althaea L. genera (Malvaceae) in Turkey
Authors: Cabi E. , Başer B. , Uzunhisarcikli M. E. , Yavru A. 
Published: December 2009

AbstractPollen grains of 22 taxa from Alcea L. and Althaea L. genera (Malvaceae) were examined using light microscope and scanning electron microscope to assess whether pollen traits can be used to delimitate at generic and specific levels. Furthermore quantitative data were subjected to cluster analysis. The pollen grains of Althaea genus are spheroidal, pantoporate, echinate which is characterized by having subglobose pattern at the base of echinae. The pollen of Alcea are spheroidal, pantoporate, echinate and baculate. Distances between pori are longer in Althaea (9.04–12.75 μm) pollens than pollens of Alcea (5.12–7.28 μm). The results of this study confirmed that differences about pollen characteristics among the taxa are not functional in separating taxa at specific level especially in Alcea genus, whereas there have been clear differences based on pollen morphology between two closely related genera. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Asparagus khorasanensis (Asparagaceae), a new species from Iran
Authors: Hamdi S. M. M. , Assadi M. 
Published: December 2009

AbstractAsparagus khorasanensis is described as a new species from Khorasan province. This species belongs to the section Asparagus. The new species is compared with its closest relative Asparagus breslerianus Schult. (1830). This species is similar to Asparagus breslerianus Schult. (1830) in having unequal cladodes, height stems, scale leaves. Asparagus khorasanensis differs from A. breslerianus in having a higher cladod number (2–4 vs. 1–3), a higher cladod diameter (1.5–2 vs. 1–1.5 mm), longer internodes (5–15 vs. 15–20 mm), longer scale like leaves (2–2.5 vs. 0.5–0.7 mm), one flowers at base of branches vs. two flowers, longer anther (3–4 vs. 1.7–2 mm), bigger berries (7–8 vs. 5–5.5 mm), longer surface of periclinal cell wall (32–48 (–50) × 12–2–(–23) vs. 12–36 (–40) × 12–18(–20) µm), surface of periclinal cell wall is convex vs. surface of periclinal cell wall is concave and shape of surface cells of seed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling of CO Poisoning and its Dynamics in HTPEM Fuel Cells
Authors: Bergmann A. , Gerteisen D. , Kurz T. 
Published: December 2009

AbstractIn this work, a dynamic, 2‐dimensional, non‐isothermal model of a PBI‐based HTPEM fuel cell has been developed. The model consists of a five‐layer geometry with gas channels, gas diffusion layers (GDL) and membrane. The catalyst layers are taken into account as infinitesimal thin reaction layers between GDL and membrane. The overall cell behaviour is simulated considering conservation of mass, momentum, species, charge and energy. The model is focussed on CO poisoning of the anode in steady state as well as in dynamic operation. Therefore, a temperature and time‐dependent approach of adsorption/desorption of CO and H2 on the catalyst sites and the electrochemical reactions of the adsorbed species is applied. The temperature dependency of the fuel cell performance is investigated in a temperature range between 125 and 160 °C at pure hydrogen operation. CO poisoning of the anode is analysed with polarisation curves for different CO concentrations as well as the dynamic response during a CO pulse. The model results are validated by experimental data of in‐house measurements.
Detecting interacting genetic loci with effects on quantitative traits where the nature and order of the interaction are unknown
Authors: Davies Joanna L. , Hein Jotun , Holmes Chris C. 
Published: December 2009

AbstractStandard techniques for single marker quantitative trait mapping perform poorly in detecting complex interacting genetic influences. When a genetic marker interacts with other genetic markers and/or environmental factors to influence a quantitative trait, a sample of individuals will show different effects according to their exposure to other interacting factors. This paper presents a Bayesian mixture model, which effectively models heterogeneous genetic effects apparent at a single marker. We compute approximate Bayes factors which provide an efficient strategy for screening genetic markers (genome‐wide) for evidence of a heterogeneous effect on a quantitative trait. We present a simulation study which demonstrates that the approximation is good and provide a real data example which identifies a population‐specific genetic effect on gene expression in the HapMap CEU and YRI populations. We advocate the use of the model as a strategy for identifying candidate interacting markers without any knowledge of the nature or order of the interaction. The source of heterogeneity can be modeled as an extension.Genet. Epidemiol. 34: 299–308, 2010. © 2009 Wiley‐Liss, Inc.
Elucidation of real‐time hardening mechanisms of two novel high‐strength calcium phosphate bone cements
Authors: Smirnov Valery V. , Rau Julietta V. , Generosi Amanda , Albertini Valerio Rossi , Ferro Daniela , Barinov Sergey M. 
Published: December 2009

AbstractDespite the numerous literature data available in the field of calcium phosphate bone cements, the mechanism and kinetics of their hardening, both of which are of great importance for cements application, in most cases, is unknown. In this work, the mechanism and kinetics of hardening of two novel high‐strength calcium phosphate bone cements were studied using the energy dispersive X‐ray diffraction technique, which allows rapid collection of the patterns. The phase transformations occurring on the setting and hardening processes were monitored in situ. Containing minimal quantity of components, whose mixing leads to the formation of cements with pH close to neutral, the cements under study are simple in handling. The main component of both formulations is tetracalcium phosphate. In both cements, the effect of the addition of high‐ and low‐molecular weight chitosan on phase development and kinetics was investigated in detail. One of the cements has the compressive strength of about 70 MPa, whereas the strength of the other, containing Ca3Al2O6, is much higher, about 100 MPa. This latter cement could be regarded as an alternative to the common low‐strength bioresorbable brushite cements. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
The effects of osmotic stress on the structure and function of the cell nucleus
Authors: Finan John D. , Guilak Farshid 
Published: December 2009

AbstractOsmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically‐ or volume‐activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper‐osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo‐osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically‐induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis. J. Cell. Biochem. 109: 460–467, 2010. © 2009 Wiley‐Liss, Inc.
Lateral line system and its innervation in Tetraodontiformes with outgroup comparisons: Descriptions and phylogenetic implications
Authors: Nakae Masanori , Sasaki Kunio 
Published: December 2009

AbstractThe lateral line system and its innervation in ten tetraodontiform families and five outgroup taxa were examined. Although some homology issues remained unresolved, tetraodontiforms were characterized by having two types (at least) of superficial neuromasts (defined by the presence or absence of supporting structures) and accessory lateral lines and neuromasts (except Molidae in which “accessory” elements were absent). The preopercular line in Tetraodontiformes was not homologous with that of typical teleosts, because the line was innervated by the opercular ramule that was newly derived from the mandibular ramus, the condition being identical to that in Lophiidae. Within Tetraodontiformes, the number of neuromasts varied between 70 and 277 in the main lines and between 0 and 52 in accessory elements. Variations were also recognized in the presence or absence of the supraorbital commissure, mandibular line, otic line, postotic line, ventral trunk line, and some lateral line nerve rami, most notably the dorsal branch of the opercular ramule, being absent in Aracanidae, Ostraciidae, Tetraodontidae, Diodontidae, and Molidae. Morphological characteristics derived from the lateral line system and its innervation provided some support for a sister relationship of tetraodontiforms with lophiiforms. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Analysis of the expression and function of BRINP family genes during neuronal differentiation in mouse embryonic stem cell‐derived neural stem cells
Authors: Terashima Michiyo , Kobayashi Miwako , Motomiya Makoto , Inoue Nobuo , Yoshida Tetsu , Okano Hideyuki , Iwasaki Norimasa , Minami Akio , Matsuoka Ichiro 
Published: December 2009

AbstractWe previously identified a novel family of genes, BRINP1, 2, and 3, that are predominantly and widely expressed in both the central nervous system (CNS) and peripheral nervous system (PNS). In the present study, we analyzed the expression pattern of three BRINP genes during differentiation of mouse embryonic stem (ES) cell‐derived neural stem cells (NSCs) and their effects on the cell‐cycle regulation of NSCs. While there was no significant expression of any BRINP‐mRNA expressed in mouse ES cells, BRINP 1 and 2‐mRNAs was expressed at high levels in the ES cell‐derived neural stem cells. Upon differentiation into neuronal cells in the presence of retinoic acid and BDNF, all three types of BRINP‐mRNA were induced with a similar time course peaking at day three of treatment. Upon differentiation into astroglial cells in the presence of serum, BRINP1‐mRNA was slightly up‐regulated, while BRINP2‐ and BRINP3‐mRNAs were almost abolished in the astrocytes. While 69.2, 26.1, and 7.7% of cells in a population of NSCs in the exponentially growing phase were in the G1, S and G2 phases, respectively, over‐expression of any one of the three BRINP genes completely abolished cells in the G2 phase and significantly reduced the cells in S phase to 11.8–13.8%. Based on these results, the physiological roles of induced BRINP genes in the cell‐cycle suppression of terminally differentiated post‐mitotic neurons are discussed. © 2009 Wiley‐Liss, Inc.
Endothelial cell heterogeneity of blood‐brain barrier gene expression along the cerebral microvasculature
Authors: Macdonald Jennifer A. , Murugesan Nivetha , Pachter Joel S. 
Published: December 2009

AbstractThe blood‐brain barrier (BBB) refers to the network of microvessels that selectively restricts the passage of substances between the circulation and the central nervous system (CNS). This microvascular network is comprised of arterioles, capillaries and venules, yet the respective contribution of each of these to the BBB awaits clarification. In this regard, it has been postulated that brain microvascular endothelial cells (BMEC) from these different tributaries might exhibit considerable heterogeneity in form and function, with such diversity underlying unique roles in physiological and pathophysiological processes. Means to begin exploring such endothelial differences in situ, free from caveats associated with cell isolation and culturing procedures, are crucial to comprehending the nature and treatment of CNS diseases with vascular involvement. Here, the recently validated approach of immuno‐laser capture microdissection (immuno‐LCM) coupled to quantitative real‐time PCR (qRT‐PCR) was used to analyze gene expression patterns of BMEC retrieved in situ from either capillaries or venules. From profiling 87 genes known to play a role in BBB function and/or be enriched in isolated brain microvessels, results imply that most BBB properties reside in both segments, but that capillaries preferentially express some genes related to solute transport, while venules tend toward higher expression of an assortment of genes involved in inflammatory‐related tasks. Fuller appreciation of such heterogeneity will be critical for efficient therapeutic targeting of the endothelium and the management of CNS disease. © 2009 Wiley‐Liss, Inc.
In vitro digestion of fresh alfalfa under different conditions of ruminal pH
Authors: Palladino Rafael A , Wawrzkiewicz Marisa , Danelón Jose L , Gaggiotti Monica , Jaurena Gustavo 
Published: December 2009

AbstractBACKGROUND: Relatively low ruminal pH values have been frequently registered in dairy cows grazing alfalfa, which can be involved in reducing feed digestion. An in vitro experiment was carried out to study the effect of ruminal pH (6.4, 6.1, 5.8 and 5.5) on the digestion of fresh alfalfa.RESULTS: Decreasing the pH, in vitro gas production (ivGP) decreased (P < 0.05). The lowest ivGP was registered at pH 5.5 and it was product of a higher lag time and a lower digestion rate. Dry matter disappearance (DMD) was not affected by pH at 48 h (P > 0.05). Neutral detergent disappearance (NDFD) at 48 h decreased below pH 6.1. The NDFD was reduced by 62% at pH 5.5 with respect to results at pH 6.4 and 6.1 (where the highest DMD and NDFD were observed).CONCLUSION: As expected, low rumen pH decreased alfalfa digestion. However, limits to ruminal digestion activity differed from those usually proposed for TMR diets. It is apparent that different relationships between rumen pH and NDFD exist when cows graze fresh alfalfa or grasses. Moreover, our results suggest the convenience to complement the data obtained through ivGP, DMD and NDFD. While ivGP and DMD seem to be more useful at early digestion times, NDFD may be a good predictor of final digestion. Copyright © 2009 Society of Chemical Industry