bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Mechanism of the Stereospecific Intramolecular Arylation of Lithiated Ureas: The Role of Li+ Probed by Electronic Structure Calculations, and by NMR and IR Spectroscopy
Authors: Grainger Damian M. , Campbell Smith Alison , Vincent Mark A. , Hillier Ian H. , Wheatley Andrew E. H. , Clayden Jonathan 
Published: December 2011

AbstractIn situ NMR and IR spectroscopy studies were carried out on the rearrangement of lithiated N‐benzyl‐N′‐aryl ureas, which involves N‐to‐C aryl transfer with retention of configuration. The IR spectroscopy studies revealed that initial benzylic lithiation was followed by migration of the aryl ring to yield a lithiated urea product without a detectable dearomatised intermediate. Similar results were obtained by NMR spectroscopy, but when 1,3‐dimethyl‐3,4,5,6‐tetrahydro‐2(1H)‐pyrimidinone (DMPU) was added to the solvent mixture, a transient dearomatised intermediate was detectable during migration of a 1‐naphthyl ring. DFT calculations highlight the importance of coordinated lithium cations, and their migration from one site to another, in the rearrangement. Rearrangement is initiated by migration of a solvated lithium cation from the anionic centre of the starting organolithium to a site close the adjacent phenyl ring, allowing retentive attack of the anionic centre on the more remote ring with movement of the solvated lithium cation to the remote ring stabilising the developing negative charge. A short‐lived spirocyclic intermediate is predicted to undergo elimination by loss of the urea substituent, completing the migration. Coordination of the carbonyl group to a second solvated lithium cation appears to be essential for this step. Calculated shifts for this intermediate when a 1‐naphthyl ring is migrating are consistent with the transient signals observed by NMR spectroscopy. Alternative pathways involving (1) invertive migration and (2) attack on the urea C=O group were also calculated and were found to require significantly higher energy transition states.
Recent approaches in sensitive enantioseparations by CE
Authors: Sánchez‐Hernández Laura , Castro‐Puyana María , Marina María Luisa , Crego Antonio L. 
Published: December 2011

AbstractThe latest strategies and instrumental improvements for enhancing the detection sensitivity in chiral analysis by CE are reviewed in this work. Following the previous reviews by García‐Ruiz et al. (Electrophoresis 2006, 27, 195–212) and Sánchez‐Hernández et al. (Electrophoresis 2008, 29, 237–251; Electrophoresis 2010, 31, 28–43), this review includes those papers that were published during the period from June 2009 to May 2011. These works describe the use of offline and online sample treatment techniques, online sample preconcentration techniques based on electrophoretic principles, and alternative detection systems to UV–Vis to increase the detection sensitivity. The application of the above‐mentioned strategies, either alone or combined, to improve the sensitivity in the enantiomeric analysis of a broad range of samples, such as pharmaceutical, biological, food and environmental samples, enables to decrease the limits of detection up to 10−12 M. The use of microchips to achieve sensitive chiral separations is also discussed.
Cyclic test of a coupled steel plate shear wall substructure
Authors: Li Chao‐Hsien , Tsai Keh‐Chyuan , Chang Jing‐Tang , Lin Chih‐Han , Chen Jia‐Chian , Lin Te‐Hung , Chen Pei‐Ching 
Published: December 2011

SUMMARYCoupled steel plate shear wall (C‐SPSW) consists of two or more steel plate shear walls interconnected by coupling beams at the floor levels. In this study, a six‐story C‐SPSW prototype building was designed. A 40% scale C‐SPSW specimen, which is representative of the bottom two‐and‐half‐story substructure of the prototype, was cyclically tested using Multi‐Axial Testing System at the National Center for Research on Earthquake Engineering in 2009. In addition to a constant vertical force representing the gravity load effects, cyclic increasing displacements and the corresponding overturning moments transmitted from the upper stories were computed online and simultaneously applied on the substructural specimen. This paper firstly introduces the designs of the prototype C‐SPSW and the test specimen. Then, the test results and the numerical simulation are discussed in detail. Test results confirm the effectiveness of the proposed column capacity design method, which aims at limiting the plastic hinge formation within the bottom quarter height of the bottom column. Test and analytical results suggest that the coupling beam rotational demands can be estimated as the design story drifts when the formation of desirable plastic mechanism of the C‐SPSW is expected. Copyright © 2011 John Wiley & Sons, Ltd.
Next generation analytic tools for large scale genetic epidemiology studies of complex diseases
Authors: Mechanic Leah E. , Chen Huann‐Sheng , Amos Christopher I. , Chatterjee Nilanjan , Cox Nancy J. , Divi Rao L. , Fan Ruzong , Harris Emily L. , Jacobs Kevin , Kraft Peter , Leal Suzanne M. , McAllister Kimberly , Moore Jason H. , Paltoo Dina N. , Province Michael A. , Ramos Erin M. , Ritchie Marylyn D. , Roeder Kathryn , Schaid Daniel J. , Stephens Matthew , Thomas Duncan C. , Weinberg Clarice R. , Witte John S. , Zhang Shunpu , Zöllner Sebastian , Feuer Eric J. , Gillanders Elizabeth M. 
Published: December 2011

AbstractOver the past several years, genome‐wide association studies (GWAS) have succeeded in identifying hundreds of genetic markers associated with common diseases. However, most of these markers confer relatively small increments of risk and explain only a small proportion of familial clustering. To identify obstacles to future progress in genetic epidemiology research and provide recommendations to NIH for overcoming these barriers, the National Cancer Institute sponsored a workshop entitled “Next Generation Analytic Tools for Large‐Scale Genetic Epidemiology Studies of Complex Diseases” on September 15–16, 2010. The goal of the workshop was to facilitate discussions on (1) statistical strategies and methods to efficiently identify genetic and environmental factors contributing to the risk of complex disease; and (2) how to develop, apply, and evaluate these strategies for the design, analysis, and interpretation of large‐scale complex disease association studies in order to guide NIH in setting the future agenda in this area of research. The workshop was organized as a series of short presentations covering scientific (gene‐gene and gene‐environment interaction, complex phenotypes, and rare variants and next generation sequencing) and methodological (simulation modeling and computational resources and data management) topic areas. Specific needs to advance the field were identified during each session and are summarized.Genet. Epidemiol. 36 : 22–35, 2012. © 2011 Wiley Periodicals, Inc.
Astrocyte stellation, a process dependent on Rac1 is sustained by the regulated exocytosis of enlargeosomes
Authors: Racchetti Gabriella , D'Alessandro Rosalba , Meldolesi Jacopo 
Published: December 2011

AbstractCultured astrocytes exhibit a flat/epitelioid phenotype much different from the star‐like phenotype of tissue astrocytes. Upon exposure to treatments that affect the small GTPase Rho and/or its effector ROCK, however, flat astrocytes undergo stellation, with restructuring of cytoskeleton and outgrowth of processes with lamellipodia, assuming a phenotype closer to that exhibited in situ. The mechanisms of this change are known only in part. Using the ROCK blocker drug Y27632, which induces rapid (tens of min), dose‐dependent and reversible stellations, we focused on two specific aspects of the process: its dependence on small GTPases and the large surface expansion of the cells. Contrary to previous reports, we found stellation to be governed by the small G protein Rac1, up to disappearance of the process when Rac1 was downregulated or blocked by a specific drug. In contrast cdc42, the other G‐protein often involved in phenotype changes, appeared not involved. The surface expansion concomitant to cytoskeleton restructuring, also dependent on Rac1, was found to be at least partially sustained by the exocytosis of enlargeosomes, small vesicles distinct from classical cell organelles, which are abundant in astrocytes. Exhaustion of stellation induced by repeated administrations of Y27632 correlated with the decrease of the enlargeosome pool. A whole‐cell process like stellation of cultured astrocytes might be irrelevant in the brain tissue. However, local restructuring of the cytoskeleton coordinate with surface expansion, occurring at critical cell sites and sustained by mechanisms analogous to those of stellation, might be of importance in both astrocyte physiology and pathology. © 2011 Wiley Periodicals, Inc.
Equipping Adolescent English Learners for Academic Achievement: An Interview With Susana Dutro and Ellen Levy
Authors: Dutro Susana , Levy Ellen , Moore David W. 
Published: December 2011

AbstractSusana Dutro and Ellen Levy are leaders of E.L. Achieve, an organization dedicated to assisting educators in equipping English learners for academic achievement. They see adolescent English learners regularly confronting the challenge of developing the language needed to fully participate in middle and high school classrooms. Their approach to helping learners meet this challenge involves systematic, proficiency‐leveled instruction in standard English along with explicit instruction in the discipline‐specific language of core content areas. They provide numerous structured opportunities with oral language to enable English learners to develop and express sophisticated thinking. When implementing school‐wide changes, they move from prominent to supportive roles as teachers and administrators assume control of the initiative. Implementing a shared vision of high quality language instruction for all adolescent English learners is seen as the most important step educators can take to best serve these youth.
Protective effects of apocynin on cisplatin‐induced ototoxicity in an auditory cell line and in zebrafish
Authors: Choi June , Im Gi Jung , Chang Jiwon , Chae Sung Won , Lee Seung Hoon , Kwon Soon‐Young , Chung Ah‐Young , Park Hae‐Chul , Jung Hak Hyun 
Published: December 2011

ABSTRACTCisplatin is a very effective anticancer drug and generates reactive oxygen species (ROS) such as superoxide anions that can deplete antioxidant protective molecules in the cochlea. These processes result in the death of cochlear hair cells by induction of apoptosis. Apocynin, which is used as a specific nicotinamide adenine dinucleotide phosphate oxidase inhibitor, has a preventive effect for intracellular ROS generation. In this study, the effect of apocynin was investigated in a cochlear organ of Corti‐derived cell line, HEI‐OC1 cells, and in transgenic zebrafish (Brn3C: EGFP). To investigate the protective effects of apocynin, HEI‐OC1 cells were treated with various concentrations of apocynin and a 20 µm concentration of cisplatin, simultaneously. An in vivo study of transgenic zebrafish (Brn3C: EGFP) was used to investigate the protective effects of apocynin on cisplatin‐induced hair cell death. In an in vitro study, apocynin appeared to protect against cisplatin‐induced apoptotic features on Hoechst 33258 staining in the HEI‐OC1 cells. Treatment of the HEI‐OC1 cells with 100 µm of apocynin, significantly decreased caspase‐3 activity. Treatment of the cells with a 100 µm concentration of apocynin and a 20 µm concentration of cisplatin significantly decreased the intracellular ROS production. In the in vivo study, apocynin significantly decreased the TUNEL reaction and prevented cisplatin‐induced hair cell loss of the neuromasts in the transgenic zebrafish at low concentrations (125 and 250 µm). These findings suggest that apocynin has antioxidative effects and prevents cisplatin‐induced apoptotic cell death in HEI‐OC1 cells as well as in zebrafish. Copyright © 2011 John Wiley & Sons, Ltd.
A review of poisonous plants that cause reproductive failure and malformations in the ruminants of Brazil
Authors: Riet‐Correa Franklin , Medeiros Rosane M. T. , Schild Ana Lucia 
Published: December 2011

ABSTRACTThe objective of this review is to provide a report on toxic plants causing reproductive problems in ruminants in Brazil. Aspidosperma pyrifolium causes abortion or stillbirth in goats, as well as most likely in sheep and cattle, in the semiarid regions of Northeastern Brazil. Intoxications by Ateleia glazioveana, Tetrapterys acutifolia and T. multiglandulosa result in abortion and neonatal mortality in cattle and sheep, and the same signs have been experimentally observed in goats. These three plants can also cause cardiac fibrosis and a nervous disease with spongiosis of the central nervous system. Other plants known to cause abortion include Enterolobium contortisiliquum, E. gummiferum, Stryphnodendron coriaceum, S. obovatum and S. fissuratum. These plants can also cause digestive signs and photosensitization. Abortions have been reported in animals intoxicated by nitrates and nitrites as well. Infertility, abortions and the birth of weak offspring have been reported in animals intoxicated by plants containing swainsonine, including Ipomoea spp., Turbina cordata and Sida carpinifolia. Trifolium subterraneum causes estrogenism in cattle. Mimosa tenuiflora and, most likely, M. ophthalmocentra cause malformations and embryonic mortality in goats, sheep and cattle in the semiarid regions of Northeastern Brazil. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular mechanism of HIV‐1 integrase–vDNA interactions and strand transfer inhibitor action: A molecular modeling perspective
Authors: Xue Weiwei , Liu Huanxiang , Yao Xiaojun 
Published: December 2011

AbstractHuman immunodeficiency virus type 1 (HIV‐1) integrase (IN) is an essential enzyme for splicing a viral DNA (vDNA) replica of its genome into host cell chromosomal DNA (hDNA) and has been recently recognized as a promising therapeutic target for developing anti‐AIDS agents. The interaction between HIV‐1 IN and vDNA plays an important role in the integration process of the virus. However, a detailed understanding about the mechanism of this interactions as well as the action of the anti‐HIV drug raltegravir (RAL, approved by FDA in 2007) targeting HIV‐1 IN in the inhibition of the vDNA strand transfer is still absent. In the present work, a molecular modeling study by combining homology modeling, molecular dynamics (MD) simulations with molecular mechanics Poisson–Boltzmann surface area (MM‐PBSA), and molecular mechanics Generalized‐Born surface area (MM‐GBSA) calculations was performed to investigate the molecular mechanism of HIV‐1 IN–vDNA interactions and the inhibition action of vDNA strand transfer inhibitor (INSTI) RAL. The structural analysis showed that RAL did not influence the interaction between vDNA and HIV‐1 IN, but rather targeted a special conformation of HIV‐1 IN to compete with host DNA and block the function of HIV‐1 IN by forcing the 3′‐OH of the terminal A17 nucleotide away from the three catalytic residues (Asp64, Asp116, and Glu152) and two Mg2+ ions. Thus, the obtained results could be helpful for understanding of the integration process of the HIV‐1 virus and provide some new clues for the rational design and discovery of potential compounds that would specifically block HIV‐1 virus replication. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Effects of mindfulness‐based stress reduction on emotional experience and expression: a randomized controlled trial
Authors: Robins Clive J. , Keng Shian‐Ling , Ekblad Andrew G. , Brantley Jeffrey G. 
Published: December 2011

AbstractObjectives: Mindfulness‐based stress reduction (MBSR) has been found to reduce psychological distress and improve psychological adjustment in medical, psychiatric, and nonclinical samples. We examined its effects on several processes, attitudes, and behavior patterns related to emotion regulation. Design: Fifty‐six adults were randomly assigned to MBSR or to a waiting list (WL). Results: Compared with WL completers (n = 21), MBSR completers (n = 20) reported significantly greater increases in trait mindfulness and decreases in absent‐mindedness, greater increases in self‐compassion, and decreases in fear of emotions, suppression of anger, aggressive anger expression, worry, and difficulties regulating emotions. The WL group subsequently received MBSR, and the two groups combined showed significant changes on all of these variables from pre‐MBSR to post‐MBSR, and on all except the 2 anger variables from pre‐test to 2‐month follow‐up, as well as significant reductions in rumination. Conclusion: An 8‐week mindfulness training program might increase mindful awareness in daily life and have beneficial impact on clinically relevant emotion regulation processes. © 2011 Wiley Periodicals, Inc. J Clin Psychol 68:1–15, 2011.
Assessment of carotid stenosis using three‐dimensional T2‐weighted dark blood imaging: Initial experience
Authors: Mihai Georgeta , Winner Marshall W. , Raman Subha V. , Rajagopalan Sanjay , Simonetti Orlando P. , Chung Yiu‐Cho 
Published: December 2011

AbstractPurpose:To evaluate the use of a T2‐weighted SPACE sequence (T2w‐SPACE) to assess carotid stenosis via several methods and compare its performance with contrast‐enhanced magnetic resonance angiography (ceMRA).Materials and Methods:Fifteen patients with carotid atherosclerosis underwent dark blood (DB)‐MRI using a 3D turbo spin echo with variable flip angles sequence (T2w‐SPACE) and ceMRA. Images were coregistered and evaluated by two observers. Comparisons were made for luminal diameter, luminal area, degree of luminal stenosis (NASCET: North American Symptomatic Endarterectomy Trial; ECST: European Carotid Surgery Trial, and area stenosis), and vessel wall area. Degree of NASCET stenosis was clinically classified as mild (<50%), moderate (50%–69%), or severe (>69%).Results:Excellent agreement was seen between ceMRA and T2w‐SPACE and between observers for assessment of lumen diameter, lumen area, vessel wall area, and degree of NASCET stenosis (r > 0.80, P < 0.001). ECST stenosis was consistently higher than NASCET stenosis (48 ± 14% vs. 24 ± 22%, P < 0.001). Area stenosis (72 ± 2%) was significantly higher (P < 0.001) than both ESCT and NASCET stenosis.Conclusion:DB‐MRI of carotid arteries using T2w‐SPACE is clinically feasible. It provides accurate measurements of lumen size and degree of stenosis in comparison with ceMRA and offers a more reproducible measure of ECST stenosis than ceMRA. J. Magn. Reson. Imaging 2012;449‐455. © 2011 Wiley Periodicals, Inc.
Erythropoietin augments bone formation in a rabbit posterolateral spinal fusion model
Authors: Rölfing Jan Hendrik Duedal , Bendtsen Michael , Jensen Jonas , Stiehler Maik , Foldager Casper Bindzus , Hellfritzsch Michel Bach , Bünger Cody 
Published: December 2011

AbstractWe tested the hypothesis that erythropoietin (EPO) enhances bone formation after posterolateral spinal fusion (PLF) in a rabbit model. Thirty‐four adult rabbits underwent posterolateral intertransverse arthrodesis at the L5–L6 level using 2.0 g autograft per side. The animals were randomly divided into two groups receiving subcutaneous daily injections of either EPO or saline for 20 days. Treatment commenced 2 days preoperatively. Hemoglobin was monitored at baseline and 2, 4, and 6 weeks after fusion surgery. After euthanasia 6 weeks postoperatively, manual palpation, radiographic, and histomorphometric examinations were performed. Bone volume of the fusion mass was estimated by CT after 6 weeks. EPO increased bone fusion volume to 3.85 ccm (3.66–4.05) compared with 3.26 ccm (2.97–3.55) in the control group (p < 0.01). EPO treatment improved vascularization of the fusion mass and increased hemoglobin levels (p < 0.01). Fusion rate tended to be higher in the EPO group based on manual palpation, CT, and radiographic examinations. For the first time EPO has shown to augment bone formation after autograft PLF in a rabbit model. Increased vascularization provides a partial explanation for the efficacy of EPO as a bone autograft enhancer. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1083–1088, 2012
How a Sphagnum fuscum‐dominated bog changed into a calcareous fen: the unique Holocene history of a Slovak spring‐fed mire
Authors: Hájková Petra , Grootjans Ab , Lamentowicz Mariusz , Rybníčková Eliška , Madaras Mikuláš , Opravilová Věra , Michaelis Dierk , Hájek Michal , Joosten Hans , Wołejko Lesław 
Published: December 2011

AbstractIn general, mires develop by autogenic succession from more groundwater‐fed to more rainwater‐fed. This study from a calcareous mire in the West Carpathians (Slovakia) describes a similar development in the Early Holocene, followed by a reverse development in the Middle and Late Holocene. Pollen, macrofossil and testate amoeba analyses show that the site started as a minerotrophic open fen woodland. After 10 700 cal a BP autogenic succession led to the accumulation of at least 1 m of Sphagnum fuscum peat. Around 9000 cal a BP, as climate could no longer sustain a stable water regime, the bog desiccated and a fire broke out. The fire removed part of the peat layer and as a consequence relative water levels rose, leading to the establishment of a wet minerotrophic swamp carr with Thelypteris palustris, Equisetum sp. and Alnus sp. with extremely slow peat accumulation. After 600 cal a BP, rapid peat accumulation with calcareous tufa formation resumed as a result of anthropogenic deforestation and hydrological changes in the catchment and resulting increased groundwater discharge. At present the mire still hosts a wealth of relict and endangered plant and animal species typical of calcareous fens and fen meadows. Copyright © 2011 John Wiley & Sons, Ltd.
Extreme events as drivers of early human behaviour in Africa? The case for variability, not catastrophic drought
Authors: Thomas David S. G. , Burrough Sallie L. , Parker Adrian G. 
Published: December 2011

AbstractExtreme Late Quaternary climatic events, sometimes of considerable continental extent, are being proposed as major contributors to ancestral human behaviour, particularly migration, in Africa. Most recently, a catastrophic drought in the Afro‐Asian monsoon region has been proposed for 16 000–17 000 years ago, driven by global impacts of the Heinrich event 1 (H1), with potentially significant consequences for Palaeolithic cultures. We provide a new analysis of the assertion and find, on examination of a wide set of palaeoenvironmental records, that the scale and extent of the proposed drought is not supported. While some parts of the African tropics, close to the equator, do appear dry at this time, data for the tropics as a whole suggest markedly variable terrestrial conditions, with some environmental systems experiencing very positive hydrological excursions during H1. We contend that in the quest for evidence of climate drivers of ancestral human behaviour, the variability associated with spatially and temporally complex climatic conditions is a significant factor in itself. Copyright © 2011 John Wiley & Sons, Ltd.