bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient and Practical One‐Pot Conversions of N‐Tosyltetrahydroisoquinolines into Isoquinolines and of N‐Tosyltetrahydro‐β‐carbolines into β‐Carbolines through Tandem β‐Elimination and Aromatization
Authors: Dong Jing , Shi Xiao‐Xin , Yan Jing‐Jing , Xing Jing , Zhang Qiang , Xiao Sen 
Published: November 2010

AbstractAn efficient, practical, and general method for conversions of N‐tosyltetrahydroisoquinolines (N‐tosyl‐THIQs) into isoquinolines and of N‐tosyltetrahydro‐β‐carbolines (N‐tosyl‐THBCs) into β‐carbolines is described. Treatment of N‐tosyl‐THIQs or N‐tosyl‐THBCs with base in dimethyl sulfoxide afforded dihydroisoquinolines or dihydro‐β‐carbolines as intermediates, and these were then oxidized in situ by molecular oxygen to furnish isoquinolines or β‐carbolines in good to high yields. Both one‐pot conversions occurred through tandem β‐elimination and aromatization.
Akt1 deficiency in schizophrenia and impairment of hippocampal plasticity and function
Authors: Balu Darrick T. , Carlson Gregory C. , Talbot Konrad , Kazi Hala , Hill‐Smith Tiffany E. , Easton Rachel M. , Birnbaum Morris J. , Lucki Irwin 
Published: November 2010

AbstractGenetic studies have associated deficient function of the serine/threonine kinase Akt1 with schizophrenia. This disorder is associated with developmental, structural, and functional abnormalities of the hippocampus that could be traced to abnormal Akt1 function. To establish a closer connection between Akt1 and hippocampal function, mice with a selective deletion of Akt1 (Akt1−/− mice) were examined for physiological and behavioral outcomes dependent on the hippocampus and associated with schizophrenia. Genetic deletion of Akt1 was associated with both impaired proliferative capacity of adult‐born hippocampal progenitors and hippocampal long‐term potentiation, indicating deficient functions of this brain region associated with neuroplasticity. Moreover, Akt1−/− mice demonstrated impairments in contextual fear conditioning and recall of spatial learning, behaviors known to selectively involve the hippocampus. Akt1−/− mice also showed reduced prepulse inhibition of the acoustic startle response, a sensorimotor gating response that is perturbed in schizophrenia. Postmortem tissue samples from patients with schizophrenia showed significant reductions of phosphorylated Akt levels in hilar neurons of the dentate gyrus, the neurogenic zone of the hippocampus. Taken together, these results implicate the Akt1 isoform in regulating hippocampal neuroplasticity and cognition and in contributing to the etiology of schizophrenia. © 2010 Wiley Periodicals, Inc.
Adult‐born neurons are necessary for extended contextual discrimination
Authors: Tronel Sophie , Belnoue Laure , Grosjean Noelle , Revest Jean‐Michel , Piazza Pier‐Vincenzo , Koehl Muriel , Abrous Djoher Nora 
Published: November 2010

AbstractNew neurons are continuously produced in the adult dentate gyrus of the hippocampus. It has been shown that one of the functions of adult neurogenesis is to support spatial pattern separation, a process that transforms similar memories into nonoverlapping representations. This prompted us to investigate whether adult‐born neurons are required for discriminating two contexts, i.e., for identifying a familiar environment and detect any changes introduced in it. We show that depleting adult‐born neurons impairs the animal's ability to disambiguate two contexts after extensive training. These data suggest that the continuous production of new dentate neurons plays a crucial role in extracting and separating efficiently contextual representation in order to discriminate features within events. © 2010 Wiley Periodicals, Inc.
Estimating the physical cluster‐size distribution within materials using atom‐probe
Authors: Stephenson L.T. , Moody M.P. , Gault B. , Ringer S.P. 
Published: November 2010

AbstractA limiting characteristic of the atom‐probe technique is the nondetection of ions and this embodies a significant “missing information” problem in investigations of atomic clustering phenomena causing difficulty in the interpretation of any atom‐probe experiment. It is shown that the measurable cluster‐size distribution can be modeled by a mixed binomial distribution. A deconvolution method based upon expectation‐maximization (EM) algorithm is presented to obtain the original physical distribution from an efficiency‐degraded distribution, thereby providing means to calculate accurate cluster number densities from atom probe results. The accuracy of this restoration was predominantly dependent upon the detector efficiency and was proved to be highly accurate in the case of conventional atom‐probe detector efficiencies (ϵ = 57%). Such considerations and measures are absolutely necessary when the number density of clusters and small precipitates is in any way regarded as important. We conclude that limitations in detector efficiency are more limiting for cluster‐finding analyses via atom‐probe techniques than spatial resolution issues, and therefore the current endeavors for improving detector technologies are well found. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Effect of long‐term cattle grazing on seasonal nitrogen and phosphorus concentrations in range forage species in the fescue grassland of southwestern Alberta
Authors: Li Chunli , Hao Xiying , Willms Walter D. , Zhao Mengli , Han Guodong 
Published: November 2010

AbstractNumerous studies have examined the nutritive quality of fodder plants in different seasons but few have related this seasonal response to long‐term grazing intensity. Our objective was to examine the effect of long‐term grazing on the concentrations of total nitrogen, δ15N, and total phosphorus in selected forage species from the fescue grassland near Stavely, Alberta. Plants were selected from paddocks that had been stocked at 0 (control), 2.4 (moderate grazing), and 4.8 (heavy grazing) animal unit months ha–1 for 58 years. Plant material from ten species was sampled and analyzed at monthly intervals from May to September in 2007. Total N and P concentrations were not (p > 0.05) affected by grazing for most species, but total N and P concentrations in Poa. pratensis L. were higher (p < 0.05) in grazed treatments than in the control. These results reflect an altered plant phenology through defoliation and illustrate delayed phenology in P. pratensis when grazed. The higher δ15N concentration for most species in the grazed treatments than the control is an indication of accelerated nitrogen cycling through dung and urine deposition.
Increased β‐cyanoalanine synthase and asparaginase activity in nitrogen‐deprived wheat exposed to cyanide
Authors: Machingura Marylou , Ebbs Stephen D. 
Published: November 2010

AbstractThe β‐cyanoalanine pathway in plants detoxifies cyanide by assimilating this metabolic poison. Given the possibility that cyanide in soil could serve as an alternate source of nitrogen for plant nutrition, this study investigated whether nitrogen deprivation of wheat seedlings altered the activity of the first enzyme of the pathway (β‐cyanoalanine synthase) or asparaginase. The results suggest that ambient, nontoxic concentrations of soil cyanide may serve as an alternate source of nitrogen for plants under nitrogen‐limiting conditions.
A combined application of thermal desorber and gas chromatography to the analysis of gaseous carbonyls with the aid of two internal standards
Authors: Kim Ki‐Hyun , Anthwal A. , Pandey Sudhir Kumar , Kabir Ehsanul , Sohn Jong Ryeul 
Published: November 2010

AbstractIn this study, a series of GC calibration experiments were conducted to examine the feasibility of the thermal desorption approach for the quantification of five carbonyl compounds (acetaldehyde, propionaldehyde, butyraldehyde, isovaleraldehyde, and valeraldehyde) in conjunction with two internal standard compounds. The gaseous working standards of carbonyls were calibrated with the aid of thermal desorption as a function of standard concentration and of loading volume. The detection properties were then compared against two types of external calibration data sets derived by fixed standard volume and fixed standard concentration approach. According to this comparison, the fixed standard volume‐based calibration of carbonyls should be more sensitive and reliable than its fixed standard concentration counterpart. Moreover, the use of internal standard can improve the analytical reliability of aromatics and some carbonyls to a considerable extent. Our preliminary test on real samples, however, indicates that the performance of internal calibration, when tested using samples of varying dilution ranges, can be moderately different from that derivable from standard gases. It thus suggests that the reliability of calibration approaches should be examined carefully with the considerations on the interactive relationships between the compound‐specific properties and the operation conditions of the instrumental setups.
High‐throughput quantification of isoflavones, biochanin A and genistein, and their conjugates in female rat plasma using LC‐ESI‐MS/MS: Application in pharmacokinetic study
Authors: Singh Sheelendra Pratap , Wahajuddin  , Ali Mushir M. , Jain Girish Kumar 
Published: November 2010

AbstractIsoflavones containing foods and dietary supplements are widely consumed for putative health benefits (e.g. cancer chemoprevention, beneficial effects on serum lipids associated with cardiovascular health, reduction of osteoporosis, relief of menopausal symptoms). This paper describes the development and validation of a sensitive high throughput LC‐ESI‐MS/MS method for quantifying biochanin A (BCA) and genistein (GEN), and their conjugates in rat plasma. The analytes were separated on a Supelco Discovery C18 (4.6×50 mm, 5.0 μm) column under isocratic condition using acetonitrile/methanol (50:50, v/v) and 0.1% acetic acid in the ratio of 90:10 v/v as a mobile phase. The intra‐ and inter‐day assay precision ranged from 2.66 to 8.34% and 4.40 to 8.10% (RSD %), respectively, and intra‐ and inter‐day assay accuracy was between 90.67–109.25% and 95.86–106.32%, respectively, for both the analytes. The lowest quantitation limit for BCA and GEN was 0.5 ng/mL in 0.1 mL of rat plasma. The method was successfully applied to the estimation of BCA, GEN and their conjugates in rat plasma following oral administration of BCA. Circulating conjugates (glucuronides/sulfates) of BCA and GEN were quantified using enzymatic hydrolysis of plasma samples. The levels of isoflavones glucuronides/sulfates were found to be much greater than the corresponding aglycones.
A sensitive column‐switching HPLC method for aripiprazole and dehydroaripiprazole and its application to human pharmacokinetic studies
Authors: Akamine Yumiko , Yasui‐Furukori Norio , Kojima Midori , Inoue Yoshimasa , Uno Tsukasa 
Published: November 2010

AbstractA simple and sensitive column‐switching HPLC‐UV method was developed for the simultaneous determination of aripiprazole, a novel atypical antipsychotic drug, and its active metabolite, dehydroaripiprazole in human plasma. Aripiprazole, its active metabolite and 7‐[5‐[4‐(3‐chloro‐2‐methylphenyl)‐1‐piperazinyl]pentyloxy]‐3,4‐dihydro‐2(1H)‐quinolinone (OPC‐14558) as an internal standard were extracted from 1 mL of plasma using a mixture of chloroform/n‐heptane (3:7, v/v), and the extract was injected into a column I (TSK BSA‐ODS/S precolumn, 5 μm) for cleanup and column II (C18 STR ODS‐II analytical column, 5 μm) for separation. Peaks were detected with an UV detector set at a wavelength of 254 nm, and the total time for chromatographic separation was ∼20 min. Mean absolute recoveries were 74.0 and 74.7% for aripiprazole and dehydroaripiprazole, respectively. Intra‐ and inter‐day CVs were less than 7.5 and 7.1% for aripiprazole concentrations ranging from 2 to 600 ng/mL, and 9.2 and 4.5% for dehydroaripiprazole concentrations ranging from 2 to 160 ng/mL. The validated concentration ranges for this method were 1–500 ng/mL and the limits of detection were 0.5 ng/mL for both aripiprazole and dehydroaripiprazole. This method was applied to pharmacokinetic study in human volunteers and patients taking aripiprazole.
Effects of intracellular organelles on the apparent diffusion coefficient of water molecules in cultured human embryonic kidney cells
Authors: Colvin Daniel C. , Jourquin Jerome , Xu Junzhong , Does Mark D. , Estrada Lourdes , Gore John C. 
Published: November 2010

AbstractThe apparent diffusion coefficient (ADC) of water in tissues is dependent on the size and spacing of structures in the cellular environment and has been used to characterize pathological changes in stroke and cancer. However, the factors that affect ADC values remain incompletely understood. Measurements of ADC are usually made using relatively long diffusion times; so they reflect the integrated effects of cellular structures over a broad range of spatial scales. We used temporal diffusion spectroscopy to study diffusion in packed cultured human embryonic kidney cells over a range of effective diffusion times following microtubule and actin/cytoskeleton depolymerization and disassembly of the Golgi complex. While Golgi disruption did not change ADC, depolymerization of the microtubule and the actin filament networks caused small decreases in ADC at short diffusion times only. Temporal diffusion spectroscopy provided a novel way to assess intracellular influences on the diffusion properties of tissue water. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Systematic review of pregnancy‐related carpal tunnel syndrome
Authors: Padua Luca , Pasquale Antonella Di , Pazzaglia Costanza , Liotta Giovanna A. , Librante Alessia , Mondelli Mauro 
Published: November 2010

AbstractThe reported incidence of pregnancy‐related carpal tunnel syndrome (PRCTS) ranges from 0.8% to 70%, and little is known of its natural history. We systematically reviewed the reported incidence of PRCTS and evaluated its natural history. We identified 214 studies that fulfilled our selection criteria. Six publications fulfilled the inclusion criteria. Five fulfilled the incidence criteria, 3 fulfilled the natural history criteria, and 2 of the 6 publications satisfied both. The reported incidence of neurophysiologically confirmed PRCTS ranged from 7% to 43%, whereas the incidence of clinically diagnosed PRCTS ranged from 31% to 62%. Symptoms persisted in more than 50% of the patients after 1 year and in about 30% after 3 years. Our review suggests that variations in the reported incidence of PRCTS largely depend on the methods used to detect this syndrome. Our data also suggest that symptoms persist in a substantial number of patients 1 or more years after delivery. Muscle Nerve 42: 697–702, 2010
Side‐chain effect of octa‐substituted POSS fillers on refraction in polymer composites
Authors: Tanaka Kazuo , Adachi Shigehiro , Chujo Yoshiki 
Published: November 2010

AbstractTo investigate the relationship between the chemical structures of the side chains of polyoctahedral oligomeric silsesquioxanes (POSS) fillers and the ability to decrease the refractive indices of the polymer composites, we examined the influence on the degree of polymer chain packing by the existence of the octa‐substituted POSS derivatives. The polymer composites containing methyl‐, ethyl‐, vinyl‐, isobutyl‐, octyl‐, octadecyl‐, cyclopentyl‐, and phenyl‐substituted POSS in poly(methyl methacrylate) (PMMA) were prepared. The packing coefficients of the PMMA composites containing POSS derivatives were evaluated from molar refractions and refractive indices of the films with the Lorentz–Lorenz equation. We found that the ethyl group shows the lowest values of the packing coefficients and a significant effect in reducing the refractive indices of the polymer composites. Finally, in summary, it was shown that POSS molecules can intrinsically offer to reduce a packing. In addition, less entanglement and smaller interactions between polymer chains and the substitution groups are favorable to release a packing, resulting in decreases in refractive indices. Our findings described here are the first efforts to quantitatively evaluate the ability of POSS fillers to lower refractive indices at the molecular level. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Waterborne polyesters partially based on renewable resources
Authors: Jasinska Lidia , Koning Cor E. 
Published: November 2010

AbstractA new experimental approach for preparing biobased, water‐soluble polyesters (PEs) via titanium(IV) n‐butoxide‐catalyzed bulk polycondensation is presented. In the described method polymers were obtained from isosorbide, maleic anhydride and poly(ethylene glycol) (PEG). The chemical structure of the synthesized PEs was confirmed using 2D NMR spectroscopy and by titration methods. Careful analysis of 2D NMR spectra viz. correlation spectra (COSY), heteronuclear single quantum correlation spectra (HSQC) and heteronuclear multiple‐bond correlation spectra (HMBC) allowed to accomplish the complete proton assignment of isosorbide, PEG, and unsaturated acid residues in the PEs. Moreover, by using NMR spectroscopy the transformation of maleic anhydride into fumaric acid ester and the absence of maleic acid ester units in the final polymer were proven. However, during polycondensation part of the unsaturated bonds has reacted in a Michael addition with isosorbide or PEG. Gel permeation chromatography measurements revealed that the unsaturated PEs have Mn values in the range 3000–5000 g/mol. These PEs, with a low content of carboxylic acid end groups, exhibited sufficient thermal resistance for practical applications, for example, as free radical curable coatings. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Synthesis and characterization of self‐catalyzed imide‐containing pthalonitrile resins
Authors: Amir Badshah , Zhou Heng , Liu Feng , Aurangzeb Hasan 
Published: November 2010

AbstractSome new amino‐ and imide‐containing phthalonitrile compounds with 1:1 molar ratio of amino group to pthalonitrile unit were successfully synthesized. The molecular structures were characterized by spectroscopic techniques. They were thermally polymerized under nitrogen/air, even in the absence of curing additives. The thermal properties of the cured products were characterized by thermogravimetric analysis and differential scanning calorimetry. The 5% weight loss temperatures ranged from 525 to 528 °C and 513 to 520 °C under nitrogen and air, respectively. Char yields (900 °C) were in the range of 62–70%. Rheometric measurements showed that the rate of the cure reaction differs for all the three monomers. The glass transition temperature advances with increasing extent of cure and disappears on postcure at 375 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Report from the Wellcome Trust/EBA “Perspectives in Clinical Proteomics” retreat – A strategy to implement Next‐Generation Proteomic Analyses to the clinic for patient benefit: Pathway to translation
Authors: Patterson Scott D. , Van Eyk Jennifer E. , Banks Rosamonde E. 
Published: November 2010

AbstractProteomics has long been thought to hold the promise of producing results of clinical utility which will influence patient treatment and outcomes. A recent Wellcome Trust/EBI meeting and retreat ‐ “Perspectives in Clinical Proteomics” ‐ brought together experts from a broad range of stakeholder groups with an interest in ensuring proteomics achieves this aim. This viewpoint presents views derived from these forums, proposing a pathway for the development of next‐generation proteomic analyses in the clinical setting from selection of candidates through to their validation and ultimate demonstration of utility through health technology assessments. Although not meant to be all encompassing, important elements for proteomics researchers to consider are presented.
Novel fluctuation‐based approach to optimization of frequency performance and degradation of nitride heterostructure field effect transistors
Authors: Matulionis A. , Liberis J. , Matulionienė I. , Šermukšnis E. , Leach J. H. , Wu M. , Morkoç H. 
Published: November 2010

AbstractThe fluctuation‐based technique has been used to shed light onto the physical processes responsible for the performance of nitride heterostructure field effect transistors. A non‐monotonic dependence of hot‐phonon lifetime on the density of two‐dimensional electron gas (2DEG) is found and interpreted in terms of plasmon–longitudinal‐optical‐phonon resonance. Experimental data show that the hot‐phonon lifetime acquires the shortest value in the vicinity of the resonance. At a fixed 2DEG density of the 2DEG, the resonance can be tuned in with supplied electric power. The signatures of the resonance have also been resolved in frequency performance of the transistors and their degradation. In particular, the transistor operation is the fastest and the reliability is the highest when the hot‐phonon lifetime is the shortest.magnified image
(online colour at: www.pss‐a.com) Drain current degradation (stars 8) correlates with hot‐phonon lifetime (curve).
The influence of early science experience in kindergarten on children's immediate and later science achievement: Evidence from the early childhood longitudinal study
Authors: Saçkes Mesut , Trundle Kathy Cabe , Bell Randy L. , O'Connell Ann A. 
Published: November 2010

AbstractThis study explores the impacts of selected early science experiences in kindergarten (frequency and duration of teachers' teaching of science, availability of sand/water table and science areas, and children's participation in cooking and science equipment activities) on children's science achievement in kindergarten and third grade using data for 8,642 children from the Early Childhood Longitudinal Study‐Kindergarten cohort (ECLS‐K). A theoretical model that depicts the relationships between the study variables was developed and tested using structural equation modeling. Results demonstrated that availability of science materials in kindergarten classrooms facilitated teachers' teaching of science and children's participation in science activities. Likewise, the frequency and the duration of kindergarten science teaching was a significant predictor of children's science activities but not of the children's end of kindergarten science achievement scores. Children's engagement with science activities that involved using science equipment also was not a significant predictor of their end of kindergarten science achievement. However, children's participation in cooking activities was. Children's prior knowledge, motivation, socio‐economic status, and gender were all statistically significant predictors of their science achievement at the end of kindergarten and end of third grade. Results of this study indicate that early science experiences provided in kindergarten are not strong predictors of children's immediate and later science achievement. Findings of the study suggest that the limited time and nature of science instruction might be related to the limited effect of the science experiences. Implications for teacher education programs and educational policy development are discussed. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 48: 217–235, 2011