bluuebunny/crossref_metadata_2025 huggingface dataset:
TGF-β sensitivity is determined by N-linked glycosylation of the type II TGF-β receptor
Authors: Kim Young-Woong , Park Jinah , Lee Hyun-Ju , Lee So-Young , Kim Seong-Jin
Published: May 2012

N-linked glycosylation is a critical determinant of protein structure and function, regulating processes such as protein folding, stability and localization, ligand–receptor binding and intracellular signalling. TβRII [type II TGF-β (transforming growth factor β) receptor] plays a crucial role in the TGF-β signalling pathway. Although N-linked glycosylation of TβRII was first demonstrated over a decade ago, it was unclear how this modification influenced TβRII biology. In the present study, we show that inhibiting the N-linked glycosylation process successfully hinders binding of TGF-β1 to TβRII and subsequently renders cells resistant to TGF-β signalling. The lung cancer cell line A549, the gastric carcinoma cell line MKN1 and the immortal cell line HEK (human embryonic kidney)-293 exhibit reduced TGF-β signalling when either treated with two inhibitors, including tunicamycin (a potent N-linked glycosylation inhibitor) and kifunensine [an inhibitor of ER (endoplasmic reticulum) and Golgi mannosidase I family members], or introduced with a non-glycosylated mutant version of TβRII. We demonstrate that defective N-linked glycosylation prevents TβRII proteins from being transported to the cell surface. Moreover, we clearly show that not only the complex type, but also a high-mannose type, of TβRII can be localized on the cell surface. Collectively, these findings demonstrate that N-linked glycosylation is essentially required for the successful cell surface transportation of TβRII, suggesting a novel mechanism by which the TGF-β sensitivity can be regulated by N-linked glycosylation levels of TβRII.
A Safe and Accurate Method of Assessing the Size of Implants Required in Orbital Floor Reconstruction
Authors: Lim Thiam Chye , Rasheed Zulfikar Mohamed , Sundar Gangadhara
Published: May 2012

Many methods to determine the size of an orbital floor implant depend on trial and error. However, this technique is imprecise and the repeated insertion and removal of the implant leads to soft tissue trauma and swelling. A method of measuring orbital floor dimensions intraoperatively using a waterproof paper ruler is presented in this study. This technique has the advantage of being simple, precise, safe, and expedient.
The Use of Risdon Cables in Pediatric Maxillofacial Trauma: A Technique Revisited
Authors: Madsen Matthew , Tiwana Paul S. , Alpert Brian
Published: May 2012

Although less common than adult fractures, fractures of the pediatric maxillofacial skeleton present unique challenges. Different considerations including variations of anatomy including tooth buds, dental variations, as well as considerations for future growth must be addressed. When traditional techniques to treat adult fractures are applied for securing intermaxillary fixation (IMF) such as arch bars, difficulty arises because the primary teeth are shorter and conventional arch bar techniques may slip off intra or postoperatively. We present a technique to achieve both IMF as well as interdental stability using a Risdon cable. Although this technique is not new, we present it as our preferred method for treating pediatric fractures of the facial skeleton where IMF must be accomplished.
Superior Orbital Fissure Syndrome: A Case Report
Authors: Evans Heath H. , Wurth Bradley A. , Penna Kevin J.
Published: May 2012

Superior orbital fissure syndrome is an infrequently encountered entity with a unique presentation and significant morbidity. This article reviews the background of the syndrome, treatments in the literature, and discusses a recent case with treatment strategy.
Demonstrating That Continents Had Drifted: Paleomagnetic Measurements at the Australian National University 1952 - 1964
Authors: Lilley F. E. M.
Published: May 2012

Over fifty years ago, the new Department of Geophysics of the Australian National University in Canberra pursued research in paleomagnetism which was to be fundamental to the major developments in Earth Sciences now known as the plate tectonics revolution. In the setting of some then unexplained phenomena such as reversely magnetized rocks, and slightly in advance of fundamental developments in the dating of rocks using radioactive decay schemes of naturally-occurring isotopes, a team led by Edward Irving obtained data for the Australian continent which, accepted and combined with data from Europe and North America, demanded that major continents of the globe had moved relative to each other over geological time. Generally these facts are recognised in histories of science, however such histories usually do not record the local Australian National University setting, which it is intended to describe in this paper. Essential for the paleomagnetic work was the skilled support of a wide range of Australian geologists, who guided collection strategy and supplied oriented samples that had been collected continent-wide. It may also be little appreciated that the first paleomagnetic measurements at the Australian National University were carried out by J. C. Jaeger on samples of Tasmanian dolerite, following work on the same rock by P. M. S. Blackett's group in England. Because these cores were vertical and the magnetization in them approximately vertical, that they were not oriented with regard to horizontal direction was unimportant. Their vertical magnetization gave a forerunner of the continental-drift result.
Perennial herbaceous crops with potential for biofuel production in the temperate regions of the USA.
Authors: Voigt T. B. , Lee D. K. , Kling G. J.
Published: May 2012

As the US government in the Energy Independence and Security Act of 2007 has mandated that 60.5 billion litres of advanced biofuels are to come from cellulosic sources in the near future, there is increasing need to produce high-yielding, well-adapted and renewable bioenergy crops. Moreover, the US Department of Energy's 'Billion-Ton Update: Bioenergy Supply for a Bioenergy and Bioproducts Industry' predicts that the temperate regions of the USA will contribute much cellulosic feedstock. In this review, the authors focus on herbaceous crops in the temperate regions of the USA and the potential these crops have to contribute to the production of advanced biofuels in the future. Featured are examinations of perennial grasses including
Andropogon gerardii
,
Arundo donax
,
Miscanthus
×
giganteus
,
Panicum virgatum
,
Phalaris arundinacea
,
Sorghastrum nutans
and
Spartina pectinata
; polystands represented by the Conservation Reserve Program (CRP) and tallgrass prairie; and the broadleaved herbaceous crops (forbs)
Helianthus grosseserratus
,
Sida hermaphrodita
,
Silphium perfoliatum
,
Solidago gigantea
and
Vernonia gigantea
. Growth characteristics, and when available, yield information is presented for each individual crop or mixed planting system. When the agronomics have been determined, individual species, rather than polystands, have been most commonly employed in the existing biomass production.
P. virgatum
(switchgrass) is an example of an herbaceous crop that has been grown in monostands in temperate regions of the USA. Conversely, CRP lands and tallgrass prairie have provided the benefits of multifunctional polystands that can improve water quality, air quality, soil erosion, greenhouse-gas emission, wildlife habitat, aesthetics, employment and rural communities along with net biomass productivity. Biomass yield information for many herbaceous crops is limited.
The EU's health claims legislation: how much evidence is enough?
Authors: Lalor F. , Wall P. G.
Published: May 2012

Health-enhancing or functional foods are designed to improve health. The food industry uses health claims to describe the properties of these foods and these are regulated all over the world. In the European Union, the European Food Safety Authority (EFSA), under Regulation 1924/2006 on nutrition and health claims reviews applications by the food industry for approval for these claims. Most of these have been rejected and 'cause and effect relationship has not been established' is the most common explanation by EFSA for rejecting the applications. However, each opinion published by EFSA needs to be considered on its own merits to fully understand the rationale for EFSA's decision. Well-designed human intervention trials are essential components of a successful opinion from EFSA. Certain common features exist for these trials, e.g. suitable target population, suitable controls for the intervention, the substance being used in the intervention is the same as that to be sold on the market place and more. More positive opinions have been published in more recent months than in the past and it seems that by studying EFSA opinions published in the past, lessons have been learnt as patterns begin to emerge. In terms of scientific expertise, the required standard has been set very high. EFSA will not establish any sort of precedent and publish a positive opinion for a claim that does not meet these high standards.
Troubling Naturalism: Shirana Shahbazi's The Curve
Authors: Rounthwaite Adair
Published: May 2012

This article performs a reading of Shirana Shahbazi's photo-based mural The Curve (2007), an artwork that interrogates the production of knowledge based on various ideas of truth in representation. The Curve meditates on knowledge production in relation to three sites: contemporary documentary photography, the history of northern European still-life painting, and the murals of religious leaders and martyrs that adorn Tehran. The effect of these multiple citations is the creation of an artwork that cannot be comfortably contextualized either in Western art history or in contemporary Iranian visual culture. The Curve thereby anticipates and attempts to block its own assimilation into art historical and critical discourses that reduce the work of Iranian artists to static reflections of a particular geographical and political reality. The artwork thus demands a consideration of the ways in which context, as a term in contemporary global art history, is ideologically constructed within a certain network of power relationships.
Spin-orbit Splitting and Lifetime Broadening in theA2Δ Electronic State ofl-C5H
Authors: Haddad Mohammad Ali , Zhao Dong-feng , Linnartz Harold , Ubachs Wim
Published: May 2012

Optical absorption bands at ∼18772 and ∼18807 cm−1, previously assigned to A2Δ-X2Π electronic origin band transitions of the linear carbon-chain radicals C5H and C5D, respectively, have been reinvestigated. The spectra have been recorded in direct absorption applying cavity ring-down spectroscopy to a supersonically expanding acetylene/helium plasma. The improved spectra allow deducing a l-C5H upper state spin-orbit coupling constant A′=−0.7(3) cm−1 and a A2Δ lifetime of 1.6±0.3 ps.
O2(1Δ) Yield Measurement by Raman Spectroscopy With Elimination of Chlorine Fluorescence Interference
Authors: Cui Rong-rong , Shi Wen-bo , Deng Lie-zheng , Yang He-ping , Sha Guo-he , Zhang Cun-hao
Published: May 2012

Deleterious chlorine fluorescence was found to occur at the same frequency as the Raman scattering of O2(1Δ) and O2(3Σ), seriously affecting the O2(1Δ) yield measurement in the reaction of chlorine with basic hydrogen peroxide by use of the Raman spectroscopy technique. To solve this problem we have taken advantage of the fact that Raman radiation is always strongly polarized while fluorescence is essentially non-polarized in a gaseous medium. When chlorine utilization of a singlet oxygen generator is 88%, O2(1Δ) yield reaches (42.4±7.4)% with the effect of chlorine fluorescence completely eliminated.
Stable High-Energy Density Super-Atom Clusters of Aluminum Hydride
Authors: Lian Ke-yan , Jiang Yuan-fei , Fei De-hou , Feng Wei , Jin Ming-xing , Ding Da-jun , Luo Yi
Published: May 2012

With the concept of super-atom, first principles calculations propose a new type of super stable cage clusters AlnH3n that are much more energetic stable than the well established clusters, AlnHn+2. In the new clusters, the aluminum core-frame acts as a super-atom with n vertexes and 2n Al-Al edges, which allow to adsorb n hydrogen atoms at the top-site and 2n at the bridge-site. Using Al12H36 as the basic unit, stable chain structures, (Al12H36)m, have been constructed following the same connection mechanism as for (AlH3)n linear polymeric structures. Apart from high hydrogen percentage per molecule, calculations have shown that these new clusters possess large heat of formation values and their combustion heat is about 4.8 times of the methane, making them a promising high energy density material.
Glass Formation ofn-Butanol: Coarse-grained Molecular Dynamics Simulations Using Gay-Berne Potential Model
Authors: Xie Gui-long , Zhang Yong-hong , Huang Shi-ping
Published: May 2012

Using coarse-grained molecular dynamics simulations based on Gay-Berne potential model, we have simulated the cooling process of liquid n-butanol. A new set of GB parameters are obtained by fitting the results of density functional theory calculations. The simulations are carried out in the range of 290-50 K with temperature decrements of 10 K. The cooling characteristics are determined on the basis of the variations of the density, the potential energy and orientational order parameter with temperature, whose slopes all show discontinuity. Both the radial distribution function curves and the second-rank orientational correlation function curves exhibit splitting in the second peak. Using the discontinuous change of these thermodynamic and structure properties, we obtain the glass transition at an estimate of temperature Tg=120±10 K, which is in good agreement with experimental results 110±1 K.
Secondary Structure Analysis of Native Cellulose by Molecular Dynamics Simulations with Coarse Grained Model
Authors: Wu Shuai , Zhan Hai-yi , Wang Hong-ming , Ju Yan
Published: May 2012

The secondary structure of different Iβ cellulose was analyzed by a molecular dynamics simulation with MARTINI coarse-grained force field, where each chain of the cellulose includes 40 D-glucoses units. Calculation gives a satisfied description about the secondary structure of the cellulose. As the chain number increasing, the cellulose becomes the form of a helix, with the diameter of screw growing and spiral rising. Interestingly, the celluloses with chain number N 4 of 6, 24 and 36 do show right-hand twisting. On the contrast, the celluloses with N 8 of 12, 16 chains are left-hand twisting. These simulations indicate that the cellulose with chain number larger than 36 will break down to two parts. Besides, the result indicates that 36-chains cellulose model is the most stable among all models. Furthermore, the Lennard-Jones potential determines the secondary structure. In addition, an equation was set up to analyze the twisting structure.
Optical Properties of CdS Nanobelts and Nanosaws Synthesized by Thermal Evaporation Method
Authors: Peng Zhi-wei , Zou Bing-suo
Published: May 2012

By a simple one-step H2-assisted thermal evaporation method, high quality CdS nanostructures have been successfully fabricated on Au coated Si substrates in large scale. The as-synthesized CdS nanostructures consisted of sword-like nanobelts and toothed nanosaws with a single-crystal hexagonal wurtzite structure. The deposition temperature played an important role in determining the size and morphology of the CdS nanostructures. A combination of vapor-liquid-solid and vapor-solid growth mechanisms were proposed to interpret the formation of CdS nanostructures. Photoluminescence measurement indicated that the nanobelts and nanosaws have a prominent green emission at about 512 nm, which is the band-to-band emission of CdS. The waveguide characteristics of both types of CdS nanostructures were observed and discussed.
CalMaTe: a method and software to improve allele-specific copy number of SNP arrays for downstream segmentation
Authors: Ortiz-Estevez Maria , Aramburu Ander , Bengtsson Henrik , Neuvial Pierre , Rubio Angel
Published: May 2012

Summary: CalMaTe calibrates preprocessed allele-specific copy number estimates (ASCNs) from DNA microarrays by controlling for single-nucleotide polymorphism-specific allelic crosstalk. The resulting ASCNs are on average more accurate, which increases the power of segmentation methods for detecting changes between copy number states in tumor studies including copy neutral loss of heterozygosity. CalMaTe applies to any ASCNs regardless of preprocessing method and microarray technology, e.g. Affymetrix and Illumina.

Availability: The method is available on CRAN (http://cran.r-project.org/) in the open-source R package calmate, which also includes an add-on to the Aroma Project framework (http://www.aroma-project.org/).

Contact:  arubio@ceit.es

Supplementary information:  Supplementary data are available at Bioinformatics online.
Correcting for the bias due to expression specificity improves the estimation of constrained evolution of expression between mouse and human
Authors: Piasecka Barbara , Robinson-Rechavi Marc , Bergmann Sven
Published: May 2012

Motivation: Comparative analyses of gene expression data from different species have become an important component of the study of molecular evolution. Thus methods are needed to estimate evolutionary distances between expression profiles, as well as a neutral reference to estimate selective pressure. Divergence between expression profiles of homologous genes is often calculated with Pearson's or Euclidean distance. Neutral divergence is usually inferred from randomized data. Despite being widely used, neither of these two steps has been well studied. Here, we analyze these methods formally and on real data, highlight their limitations and propose improvements.

Results: It has been demonstrated that Pearson's distance, in contrast to Euclidean distance, leads to underestimation of the expression similarity between homologous genes with a conserved uniform pattern of expression. Here, we first extend this study to genes with conserved, but specific pattern of expression. Surprisingly, we find that both Pearson's and Euclidean distances used as a measure of expression similarity between genes depend on the expression specificity of those genes. We also show that the Euclidean distance depends strongly on data normalization. Next, we show that the randomization procedure that is widely used to estimate the rate of neutral evolution is biased when broadly expressed genes are abundant in the data. To overcome this problem, we propose a novel randomization procedure that is unbiased with respect to expression profiles present in the datasets. Applying our method to the mouse and human gene expression data suggests significant gene expression conservation between these species.

Contact:  marc.robinson-rechavi@unil.ch; sven.bergmann@unil.ch

Supplementary information:  Supplementary data are available at Bioinformatics online.
MicrobeDB: a locally maintainable database of microbial genomic sequences
Authors: Langille Morgan G. I. , Laird Matthew R. , Hsiao William W. L. , Chiu Terry A. , Eisen Jonathan A. , Brinkman Fiona S. L.
Published: May 2012

Summary: Analysis of microbial genomes often requires the general organization and comparison of tens to thousands of genomes both from public repositories and unpublished sources. MicrobeDB provides a foundation for such projects by the automation of downloading published, completed bacterial and archaeal genomes from key sources, parsing annotations of all genomes (both public and private) into a local database, and allowing interaction with the database through an easy to use programming interface. MicrobeDB creates a simple to use, easy to maintain, centralized local resource for various large-scale comparative genomic analyses and a back-end for future microbial application design.

Availability: MicrobeDB is freely available under the GNU-GPL at: http://github.com/mlangill/microbedb/

Contact:  morgan.g.i.langille@gmail.com
New iron(III) nitrate hydrates: Fe(NO3)3·xH2O withx= 4, 5 and 6
Authors: Schmidt Horst , Asztalos Annifrid , Bok Frank , Voigt Wolfgang
Published: May 2012

Crystals of the title compounds were grown from their hydrous melts or solutions. The crystal structure of iron(III) trinitrate hexahydrate {hexaaquairon(III) trinitrate, [Fe(H2O)6](NO3)3} is built up from [Fe(H2O)6]2+octahedra and nitrate anions connectedviahydrogen bonds. In iron(III) trinitrate pentahydrate {pentaaquanitratoiron(III) dinitrate, [Fe(NO3)(H2O)5](NO3)2}, one water molecule in the coordination octahedron of the FeIIIatom is substituted by an O atom of a nitrate group. Iron(III) trinitrate tetrahydrate {triaquadinitratoiron(III) nitrate monohydrate, [Fe(NO3)2(H2O)3]NO3·H2O} represents the first example of a simple iron(III) nitrate with pentagonal–bipyramidal coordination geometry, where two bidentate nitrate anions and one water molecule form a pentagonal plane.
2-[4,5-Diphenyl-2-(pyridin-2-yl)-1H-imidazol-1-yl]-3-phenylpropan-1-ol
Authors: Yang Liangru , Xiao Yongmei , He Kun , Yuan Jinwei , Mao Pu
Published: May 2012

In the title compound, C29H25N3O, the central imidazole ring forms dihedral angles of 64.7 (3), 33.5 (3) and 81.2 (2)° with the pyridyl and two phenyl substituents, respectively. An intramolecular C—H...N hydrogen bond is observed. In the crystal, O—H...N and C—H...O hydrogen bonds link the molecules into chains parallel to the a axis.
2-[(4-Chlorophenyl)(2-hydroxy-5-oxocyclopent-1-en-1-yl)methyl]-3-hydroxycyclopent-2-en-1-one
Authors: Li Gongzhen , Cai Peijun , Huo Junhao , Shi Chong
Published: May 2012

There are two molecules in the asymmetric unit of the title compound, C17H15ClO4, in which the dihedral angles between the five-membered rings are 57.3 (1) and 51.4 (1)°. An intramolecular O—H...O hydrogen bond occurs in each molecule. In the crystal, O—H...O and C—H...O hydrogen bonds link the moleclues into chains along the b axis.
A novel monoclinic phase of impurity-doped CaGa2S4 as a phosphor with high emission intensity
Authors: Suzuki Akihiro , Takizawa Takeo , Hidaka Chiharu , Shigetaka Nomura , Kitajima Ittetsu
Published: May 2012

In the solid-state synthesis of impurity-doped CaGa2S4, calcium tetrathiodigallate(III), a novel phosphor material (denominated as the X-phase), with monoclinic symmetry in the space group P21/a, has been discovered. Its emission intensity is higher than that of the known orthorhombic polymorph of CaGa2S4 crystallizing in the space group Fddd. The asymmetric unit of the monoclinic phase consists of two Ca, four Ga and eight S sites. Each of the Ca and Ga atoms is surrounded by seven and four sulfide ions, respectively, thereby sharing each of the sulfur sites with the nearest neighbours. In contrast, the corresponding sites in the orthorhombic phase are surrounded by eight and four S atoms, respectively. The photoluminescence peaks from Mn2+ and Ce3+ in the doped X-phase, both of which are supposed to replace Ca2+ ions, have been observed to shift towards the high energy side in comparison with those in the orthorhombic phase. This suggests that the crystal field around the Mn2+ and Ce3+ ions in the X-phase is weaker than that in the orthorhombic phase.
Bis(dicyanamido-κN)tetrakis(pyridine-κN)nickel(II)
Authors: Wöhlert Susanne , Wriedt Mario , Jess Inke , Näther Christian
Published: May 2012

In the crystal structure of the title compound, [Ni(C2N3)2(C5H5N)4], the NiII cations are coordinated by four pyridine ligands and two dicyanamide anions into discrete complexes. The shortest Ni...Ni separation is 8.1068 (10) Å. The structure is pseudo-centrosymmetric and can also be refined in the space group C2/c in which both anionic ligands are strongly disordered and the refinement leads to significantly poorer reliability factors.
N-(1-Acetyl-5-benzoyl-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazol-3-yl)benzamide
Authors: Bai Xiao-Guang , Wang Ju-Xian , Wang Yu-Cheng
Published: May 2012

In the molecule of the title compound, C21H18N4O3, the fused pyrrolo[3,4-c]pyrazole ring system is approximately planar [maximum deviation = 0.0486 (16) Å] and forms dihedral angles of 87.21 (8) and 35.46 (7)° with the phenyl rings. In the crystal, N—H...O and C—H...O hydrogen bonds and weak C—H...π interactions link the molecules into chains parallel to [201].
rac-1-(2-Aminocarbonyl-2-bromoethyl)pyridinium bromide
Authors: Köppen Robert , Emmerling Franziska , Koch Matthias
Published: May 2012

In the crystal structure of the title compound, C8H10BrN2O+·Br−, intermolecular N—H...Br hydrogen bonds link the molecules into infinite chains along [001]. The inclined angle between the pyridine ring plane and the plane defined by the acid amide group is 63.97 (4)°.
4-[(5-Bromo-2-hydroxybenzylidene)amino]-3-propyl-1H-1,2,4-triazole-5(4H)-thione
Authors: Wu Xin , Yuan Cai-Xia , Ma Ling , Zhai Kai-Lu , Zhu Miao-Li
Published: May 2012

The asymmetric unit of the title compound, C12H13BrN4OS, contains two independent molecules in which the dihedral angles between the triazole and benzene rings are 2.9 (3) and 7.5 (3)°. The thione group is of the form R
2C=S. An intramolecular O—H...N hydrogen bond occurs in each molecule. The crystal structure features weak N—H...S interactions and π–π stacking of the benzene rings [centroid–centroid distance = 3.667 (3) Å].
Decachlorohexa-1,5-diene
Authors: Schollmeyer Dieter , Detert Heiner
Published: May 2012

The title compound, C6Cl10, cystallizes in a nearly C2-symmetrical gauche conformation. Both trichlorovinyl groups are nearly planar [Cl—C—C—Cl torsion angles = −178.47 (12) and −179.93 (11)°] and the lengths of their C—Cl bonds increase from the terminal trans and cis C—Cl bonds to the internal bonds. The Cl—C—Cl bond angles of the terminal dichloromethylene units are compressed to 111.75 (11) and 111.40 (11)°.
1-(5-Bromo-1-benzofuran-2-yl)ethanone
Authors: Fun Hoong-Kun , Quah Ching Kheng , Abdel-Aziz Hatem A.
Published: May 2012

The title compound, C10H7BrO2, is approximately planar (r.m.s. deviation = 0.057 Å for the 13 non-H atoms). In the crystal, molecules are linked via C—H...O hydrogen bonds into C(5) chains propagating in [100].
Ethyl 2-(4-bromophenyl)-1-phenyl-1H-benzimidazole-5-carboxylate
Authors: Yoon Yeong Keng , Ali Mohamed Ashraf , Choon Tan Soo , Arshad Suhana , Razak Ibrahim Abdul
Published: May 2012

In the title compound, C22H17BrN2O2, the benzimidazole ring system is essentially planar, with a maximum deviation of 0.017 (1) Å, and forms dihedral angles of 27.79 (6) and 64.43 (6)° with the phenyl and bromo-substituted benzene rings, respectively. In the crystal, molecules are linked into one-dimensional chains along the a axis by weak C—H...O hydrogen bonds. Weak intermolecular C—H...π interactions are also present.
1-(3-Ethylphenyl)-4,6-dimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile
Authors: Al-Said Mansour S. , Ghorab Mostafa M. , Ghabbour Hazem A. , Arshad Suhana , Fun Hoong-Kun
Published: May 2012

In the title compound, C16H16N2O, the essentially planar 1,2-dihydropyridine ring [maximum deviation = 0.021 (1) Å] makes a dihedral angle of 85.33 (8)° with the benzene ring. In the crystal, molecules are linked into a chain along the b axis via C—H...O interactions.
3-{[Bis(pyridin-2-ylmethyl)amino]methyl}-2-hydroxy-5-methylbenzaldehyde
Authors: Wang Ruo-Xu , Gao Da-Zhi , Ye Fan , Wu Yan-Fei , Zhu Dun-Ru
Published: May 2012

In the title compound, C21H21N3O2, the pyridine rings and the benzene ring lie in a propeller arrangement around the central tertiary amine N atom. The dihedral angles formed by the benzene ring with the pyridine rings are 61.0 (3) and 49.6 (3)°, while the dihedral angle between the pyridine rings is 69.7 (3)°. The molecular conformation is stabilized by intramolecular bifurcated O—H...N hydrogen bonds. In the crystal, inversion dimers are formed via pairs of C—H...N hydrogen bonds.
N,N′-Dibutyl-N,N,N′,N′-tetramethylethane-1,2-diaminium μ-oxido-bis[trichloridoferrate(III)]
Authors: Närhi Sari M. , Kostamo Jatta , Asikkala Janne , Oilunkaniemi Raija , Laitinen Risto S.
Published: May 2012

The asymmetric unit of the title compound, (C14H34N2)[Fe2Cl6O], contains one complete cation, two half-cations and two anions. The two half-cations are completed by crystallographic inversion symmetry. The FeIII atoms adopt fairly regular FeCl3O tetrahedral geometries, although the bridging Fe—O—Fe bond angles differ significantly in the two anions, which both adopt an eclipsed conformation. In the crystal, the components are linked by C—H...Cl and C—H...O interactions.
Poly[(μ3-benzene-1,3-dicarboxylato-κ4
O
1:O
1′:O
3,O
3′)bis(pyridine-κN)cobalt(II)]
Authors: Xie Fengxia , Zhang Dan , Zhang Xinxin
Published: May 2012

In the asymmetric unit of the title polymeric compound, [Co(C8H4O4)(C5H5N)2]
n
, there are two crystallographically independent CoII atoms, each of which is six-coordinated in a distorted octahedral geometry by four O atoms from benzenedicarboxylate anions and two N atoms from pyridine ligands. The benzenedicarboxylate dianions bridge the CoII atoms into a tape running along the b axis. C—H...O hydrogen bonds are observed in the tape and between the tapes.
2-[4-(Benzyloxy)benzylidene]malononitrile
Authors: Gan Hai-feng , Liu Xue-wei , Fang Zheng , Guo Kai
Published: May 2012

In the title molecule, C17H12N2O, the dihedral angle between the two benzene rings is 84.98 (10)°. The dicyanoethylene group is coplanar with the benzene ring to which it is bonded. No classic hydrogen bonds were found in the crystal.
(1S*,5R*)-9-Phenyl-9-azabicyclo[3.3.1]nonan-3-one
Authors: Jiang Zhen-ju , He Qi , Li Zhen , Wang Zhou-yu
Published: May 2012

In the title compound, C14H17NO, the piperidinone and piperidine rings both adopt a chair conformation. The chiral crystals were obtained from a racemic reaction product via spontaneous resolution.
A new dabco-templated metal sulfate: 1,4-diazoniabicyclo[2.2.2]octane hexaaquacadmium bis(sulfate)
Authors: Wang Bi-Qin , Yan Hai-Biao , Fang Ci-Jun , Zhang Zhi
Published: May 2012

The title double molecular salt, (C6H14N2)[Cd(H2O)6](SO4)2, is an isostructure of its Mn and Co analogues. The CdII atom adopts a near-regular CdO6 octahedral coordination geometry. The crystal structure can be described as an alternation of cationic and anionic layers along [010], and numerous O—H...O and N—H...O hydrogen bonds are observed. No thermal anomalies corresponding to possible phase transitions were observed in DSC (differential scanning calorimetry) measurements and the 93 K structure is almost the same as the room-temperature structure.
4-Phenyl-1H-imidazole-2(3H)-thione
Authors: Owczarzak Anita M. , Kubicki Maciej
Published: May 2012

In the asymmetric unit of the title compound, C9H8N2S, there are four symmetry-independent molecules (Z′ = 4). The geometrical features of these molecules are quite similar: in the normal probability plots the R
2 correlation factors for bond lengths and angles are generally around 0.95. The twist angles between the imidazole and phenyl rings (which are planar within 3σ) range from 9.0 (6) to 13.1 (5)°. In the crystal, pairs of independent molecules are joined by linear N—H...S and weak C—H...S hydrogen bonds, forming infinite ribbons, of the type ∼ABABAB∼ and ∼CDCDCD∼, propagating along [110]. Second-order hydrogen-bonded R
2
2(8) rings are formed via interweaving infinite C
2
2(8) chains.
2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylate
Authors: Cai Hong-Xin , Zhang Zhao-Po
Published: May 2012

In the title molecule, C13H19NO4, except for two C atoms of the tert-butyl group, the non-H atoms are almost coplanar (r.m.s. deviation = 0.2542 Å). In the crystal, molecules are linked into centrosymmetric dimers by two intermolecular N—H...O hydrogen bonds, forming an R
2
2(10) ring motif.
4-[(E)-(Hydroxyimino)methyl]-N,N-dimethylanilinium chloride
Authors: Devi T. Uma , Kalpana G. , Priya S. , Ravikumar K. , Selvanayagam S.
Published: May 2012

In the title compound, C9H13N2O+·Cl−, the cation, apart from the methyl groups, is almost planar, with a maximum deviation of 0.040 (1) Å; the methyl C atoms deviate by 0.389 (2) and −1.247 (1) Å, from the mean plane. In the crystal, cations and anions associate through C—H...Cl hydrogen bonds, forming a helical arrangement. In addition, intermolecular O—H...Cl, N—H...Cl and C—H...N interactions are observed.
catena-Poly[[diaquanickel(II)]-bis(μ-2-{[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetato)]
Authors: Gao Ru-Qin , Xia Chao-Hui , Li Guo-Ting
Published: May 2012

In the title compound, [Ni(C9H6N3O3S)2(H2O)2]
n
, the NiII atom, located on an inversion center, is ligated in an octahedral geometry by two carboxylate O atoms from two 2-{[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]sulfanyl}acetate (L) ligands and two O atoms from water molecules in the equatorial plane, and two pyridine N atoms from other two L ligands at the apical sites. Two L ligands bridge pairs of metal atoms in an antiparallel manner, forming centrosymmetric dinuclear quasi-rectangular units which are linked into infinite double-stranded chains parallel to [100]. O—H...O hydrogen bonds between the coordinating water molecules and the carboxylate groups of the L ligand as well as interchain S...N interactions [2.726 (2)–3.363 (2) Å] lead to the formation of a layer structure parallel to (001).
1,4-Dimethylpiperazine-1,4-diium dibromide dihydrate
Authors: Sun Su-Wen
Published: May 2012

In the title hydrated molecular salt, C6H16N2
2+·2Br−·2H2O, the complete 1,4-dimethylpiperazine-1,4-diium dication is generated by crystallographic inversion symmetry and both exocyclic C—N bonds are in equatorial orientations. In the crystal, the components are linked by N—H...O and O—H...Br hydrogen bonds, generating chains propagating in [110].
Diaquabis{1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole-κN
3}dichloridocadmium hexahydrate
Authors: Xie Xin-Nian , Lu Meng , Yuan Juan , Yang Huai-Xia
Published: May 2012

In the title complex, [CdCl2(C11H10N4)2(H2O)2]·6H2O, the CdII atom is located on a twofold rotation axis and is coordinated by two N atoms from two 1-[(1H-benzimidazol-2-yl)methyl]-1H-imidazole ligands and two water O atoms in equatorial positions and by two Cl atoms in axial positions, leading to an elongated octahedral environment. The two coordinating and two of the lattice water molecules are also located on twofold rotation axes. In the crystal, complex molecules and solvent water molecules are linked through a complex intermolecular N—H...O, O—H...N, O—H...O and O—H...Cl hydrogen-bonding scheme into a three-dimensional network.
2,17-Dichloro-8,9,10,11-tetrahydro-19H-dibenzo[k,n][1,10,4,7]dioxadiazacyclopentadecine-7,12(6H,13H)-dione
Authors: Pojarová Michaela , Dušek Michal , Sedláková Zdeňka , Makrlík Emanuel
Published: May 2012

In the crystal structure of the title compound, C19H18Cl2N2O4, N—H...O hydrogen bonds link the molecules into infinite chains along the b axis. The structure also features weak C—H...O and C—H...Cl hydrogen bonds and C—H...π and (lone pair)...π interactions [Cl...centroid = 3.5871 (7) Å]. An intramolecular N—H...O bond occurs.
{4,4′,6,6′-Tetrabromo-2,2′-[2,2-dimethylpropane-1,3-diylbis(nitrilomethanylylidene)]diphenolato}nickel(II)
Authors: Kargar Hadi , Kia Reza , Tahir Muhammad Nawaz
Published: May 2012

The asymmetric unit of the title compound, [Ni(C19H16Br4N2O2)], comprises half of a Schiff base complex. The geometry around the NiII atom, located on a twofold rotation axis, is distorted square-planar, which is supported by the N2O2 donor atoms of the coordinated ligand. The dihedral angle between the substituted benzene rings is 23.19 (17)°. In the crystal, a short intermolecular Br...Br [3.6475 (7) Å] interaction is present.
2-tert-Butyl-4-chloro-5-[4-(2-fluoroethoxy)benzyloxy]pyridazin-3(2H)-one
Authors: Jing Huihui , Mou Tiantian , Zhang Xianzhong
Published: May 2012

In the title compound, C17H20ClFN2O3, the dihedral angle between the pyridazine and benzene rings is 41.37 (10)°. In the crystal, there are no significant intermolecular interactions present. The terminal –CH2F group is disordered over two sets of sites with an occupancy ratio of 0.737 (2):0.263 (2).
N-(4-Methylpiperazin-4-ium-1-yl)dithiocarbamate sesquihydrate
Authors: Mietlarek-Kropidłowska Anna , Chojnacki Jarosław , Wityk Paweł , Wieczór Miłosz , Becker Barbara
Published: May 2012

In the crystal structure of the title compound, C6H13N3S2·1.5H2O, weak N—H...S interactions between the zwitterionic molecules are observed, leading to an extensively folded layered arrangement parallel to (100). There are three crystallographically independent water molecules in the asymmetric unit, which are disordered and only half occupied.
2-[(Diphenylphosphoryl)(hydroxy)methyl]-5-methoxyphenol
Authors: Shao Yutian , Yang Chao , Xia Wujiong
Published: May 2012

In the title compound, C20H19O4P, the dihedral angle between the phenyl rings is 73.3 (4)° and the dihedral angles between the benzene ring and the two phenyl rings are 43.0 (3) and 54.3 (1)°. In the crystal, O—H...O hydrogen bonds and weak O—H...O interactions are observed, which form a supramolecular sheet parallel to (010).
Di-μ-iodido-bis[(dimethyl 2,2′-biquinoline-4,4′-dicarboxylate-κ2
N,N′)copper(I)]
Authors: Starosta Radosław , Komarnicka Urszula K. , Nagaj Justyna , Stokowa-Sołtys Kamila , Bykowska Aleksandra
Published: May 2012

In the centrosymmetric dinuclear title complex, [Cu2I2(C22H16N2O4)2], the CuI atom is coordinated in a distorted tetrahedral geometry by an N,N′-bidentate dimethyl 2,2′-biquinoline-4,4′-dicarboxylate ligand and two symmetry-related I atoms, which act as bridges to a symmetry-related CuI atom. The distance between the CuI atoms within the dinuclear unit is 2.6723 (11) Å.
2-Amino-3-carboxypyrazin-1-ium perchlorate bis(2-aminopyrazin-1-ium-3-carboxylate) monohydrate
Authors: Berrah Fadila , Bouacida Sofiane , Bouhraoua Ahlem , Roisnel Thierry
Published: May 2012

The asymmetric unit of the title compound, C5H6N3O2
+·ClO4
−·2C5H5N3O2·H2O, comprises two symmetry-independent zwitterions, one cation, one perchlorate anion and one water molecule. In the crystal, the three different types of organic entities are linked by N—H...O and N—H...N hydrogen bonds, forming undulating sheets parallel to (1-10). These sheets are in turn connected by O—H...N and O—H...O hydrogen bonds involving perchlorate anions and water molecules, forming a three-dimensional network. Intramolecular N—H...O and weak intermolecular C—H...O hydrogen bonds are also present.
PDE5 inhibitors, sildenafil and vardenafil, reverse multidrug resistance by inhibiting the efflux function of multidrug resistance protein 7 (ATP‐binding Cassette C10) transporter
Authors: Chen Jun‐Jiang , Sun Yue‐Li , Tiwari Amit K. , Xiao Zhi‐Jie , Sodani Kamlesh , Yang Dong‐Hua , Vispute Saraubh G. , Jiang Wen‐Qi , Chen Si‐Dong , Chen Zhe‐Sheng
Published: May 2012

Phosphodiesterase type 5 (PDE5) inhibitors are widely used in the treatment of male erectile dysfunction and pulmonary hypertension. Recently, several groups have evaluated the ability of PDE5 inhibitors for their anticancer activities. Previously, we had shown that sildenafil, vardenafil and tadalafil could reverse P‐glycoprotein (ATP‐binding cassette B1)‐mediated MDR. In the present study, we determined whether these PDE5 inhibitors have the potential to reverse multidrug resistance protein 7 (MRP7; ATP‐binding cassette C10)‐mediated MDR. We found that sildenafil and vardenafil dose‐dependently enhanced the sensitivity of MRP7‐transfected HEK293 cells to paclitaxel, docetaxel and vinblastine, while tadalafil had only a minimal effect. Accumulation and efflux experiments demonstrated that sildenafil and vardenafil increased the intracellular accumulation of [3H]‐paclitaxel by inhibiting the efflux of [3H]‐paclitaxel in HEK/MRP7 cells. In addition, immunoblot and immunofluorescence analyses indicated that no significant alterations of MRP7 protein expression and localization in plasma membranes were found after treatment with sildenafil, vardenafil or tadalafil. These results demonstrate that sildenafil and vardenafil reverse MRP7‐mediated a MDR through inhibition of the drug efflux function of MRP7. Our findings indicate a potentially novel use of PDE5 inhibitors as an adjuvant chemotherapeutic agent in clinical practice. (Cancer Sci, doi: 10.1111/j.1349‐7006.2012.02328.x, 2012)
Exploring the relationship betweenNDVIand African elephant population density in protected areas
Authors: Duffy James P. , Pettorelli Nathalie
Published: May 2012

Assessing the extent to which populations are limited by bottom‐up processes driven by food limitation is crucial to our understanding of how ecosystems should be managed. Using satellite‐derived Normalised Difference Vegetation Index (NDVI) as an index of resource availability, we investigated the relationships between greenness levels and African elephant (Loxodonta africana) population densities. Our results unveiled a positive relationship betweenNDVIand elephant densities in nonforest populations, but failed to capture any significant effects of survey area and type, number of years after the continental poaching ban and theIUCNcategory of the protected area in which the survey was undertaken. The number of forest elephant populations for which density estimates were available was very low, and no significant relationship betweenNDVIand forest elephant density could be established. Altogether, our study suggests thatNDVIcan successfully be linked to megaherbivore abundance across Africa and further highlights that a continental approach to energy–abundance relationships can be conducted in a relatively low‐cost manner and short timescale, supporting managers' efforts to identify future suitable areas for elephant populations.
Are responses of herbivores to environmental variability spatially consistent in alpine ecosystems?
Authors: Nielsen Anders , Yoccoz Nigel G. , Steinheim Geir , Storvik Geir O. , Rekdal Yngve , Angeloff Michael , Pettorelli Nathalie , Holand Øystein , Mysterud Atle
Published: May 2012

Animal responses to global climate variation might be spatially inconsistent. This may arise from spatial variation in factors limiting populations' growth or from differences in the links between global climate patterns and ecologically relevant local climate variation. For example, the North Atlantic Oscillation (NAO) has a spatially consistent relation to temperature, but inconsistent spatial relation to snow depth in Scandinavia. Furthermore, there are multiple mechanistic ways by which climate may limit animal populations, involving both direct effects through thermoregulation and indirect pathways through trophic interactions. It is conceptually appealing to directly model the predicted mechanistic links. This includes the use of climate variables mimicking such interactions, for example, to use growing degree days (GDD) as a proxy for plant growth rather than average monthly temperature. Using a unique database of autumn body mass of 83331 domestic lambs from the period 1992–2007 in four alpine ranges in Norway, we demonstrate the utility of hierarchical, mechanistic path models fitted using a Bayesian approach to analyse explicitly predicted relationships among environmental variables and between lamb body mass and the environmental variables. We found large spatial variation in strength of responses of autumn lamb body mass to the NAO, to a proxy for plant growth in spring (the Normalized Difference Vegetation Index, NDVI) and effects even differed in direction to local summer climate. Average local temperature outperformed GDD as a predictor of the NDVI, whereas the NAO index in two areas outperformed local weather variables as a predictor of lamb body mass, despite the weaker mechanistic link. Our study highlights that spatial variation in strength of herbivore responses may arise from several processes. Furthermore, mechanistically more appealing measures do not always increase predictive power due to scale of measurement and since global measures may provide more relevant “weather packages” for larger scales.
Feedback from plant species change amplifies CO2 enhancement of grassland productivity
Authors: Polley H. Wayne , Jin Virginia L. , Fay Philip A.
Published: May 2012

Dynamic global vegetation models simulate feedbacks of vegetation change on ecosystem processes, but direct, experimental evidence for feedbacks that result from atmospheric CO2 enrichment is rare. We hypothesized that feedbacks from species change would amplify the initial CO2 stimulation of aboveground net primary productivity (ANPP) of tallgrass prairie communities. Communities of perennial forb and C4 grass species were grown for 5 years along a field CO2 gradient (250–500 μL L−1) in central Texas USA on each of three soil types, including upland and lowland clay soils and a sandy soil. CO2 enrichment increased community ANPP by 0–117% among years and soils and increased the contribution of the tallgrass species Sorghastrum nutans (Indian grass) to community ANPP on each of the three soil types. CO2‐induced changes in ANPP and Sorghastrum abundance were linked. The slope of ANPP‐CO2 regressions increased between initial and final years on the two clay soils because of a positive feedback from the increase in Sorghastrum fraction. This feedback accounted for 30–60% of the CO2‐mediated increase in ANPP on the upland and lowland clay soils during the final 3 years and 1 year of the experiment, respectively. By contrast, species change had little influence on the ANPP‐CO2 response on the sandy soil, possibly because Sorghastrum increased largely at the expense of a functionally similar C4 grass species. By favoring a mesic C4 tall grass, CO2 enrichment approximately doubled the initial enhancement of community ANPP on two clay soils. The CO2‐stimulation of grassland productivity may be significantly underestimated if feedbacks from plant community change are not considered.
Different inter‐annual responses to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing
Authors: Song Ming‐Hua , Yu Fei‐Hai , Ouyang Hua , Cao Guang‐Min , Xu Xing‐Liang , Cornelissen Johannes H.C.
Published: May 2012

Plant species and functional groups in nitrogen (N) limited communities may coexist through strong eco‐physiological niche differentiation, leading to idiosyncratic responses to multiple nutrition and disturbance regimes. Very little is known about how such responses depend on the availability of N in different chemical forms. Here we hypothesize that idiosyncratic year‐to‐year responses of plant functional groups to availability and form of nitrogen explain species coexistence in an alpine meadow community after release from grazing. We conducted a 6 year N addition experiment in an alpine meadow on the Tibetan Plateau released from grazing by livestock. The experimental design featured three N forms (ammonium, nitrate, and ammonium nitrate), crossed with three levels of N supply rates (0.375, 1.500 and 7.500 g N m−2 yr−1), with unfertilized treatments without and with light grazing as controls. All treatments showed increasing productivity and decreasing species richness after cessation of grazing and these responses were stronger at higher N rates. Although N forms did not affect aboveground biomass at community level, different functional groups did show different responses to N chemical form and supply rate and these responses varied from year to year. In support of our hypothesis, these idiosyncratic responses seemed to enable a substantial diversity and biomass of sedges, forbs, and legumes to still coexist with the increasingly productive grasses in the absence of grazing, at least at low and intermediate N availability regimes. This study provides direct field‐based evidence in support of the hypothesis that idiosyncratic and annually varying responses to both N quantity and quality may be a key driver of community structure and species coexistence. This finding has important implications for the diversity and functioning of other ecosystems with spatial and temporal variation in available N quantity and quality as related to changing atmospheric N deposition, land‐use, and climate‐induced soil warming.