bluuebunny/crossref_metadata_2025_split huggingface dataset:
Essential oil composition of Hypericum hirsutum L.
Authors: Gudžic B. T. , Šmelcerović A. , D̄ord̄ević S. , Mimica‐Dukić N. , Ristić M. 
Published: September 2006

AbstractThe essential oil of Hypericum hirsutum was analysed for the first time. Twenty‐seven components were identified. The non‐terpene compounds had the highest contribution (46.6%). A low monoterpenes content (1.3%) characterized the oil. The major constituents were n‐undecane (32.2%), patchoulene (11.8%) and caryophyllene oxide (9.3%), which are not significantly represented in the essential oils of other species of the genus Hypericum examined. Copyright © 2006 John Wiley & Sons, Ltd.
The admixture maximum likelihood test: a novel experiment‐wise test of association between disease and multiple SNPs
Authors: Tyrer Jonathan , Pharoah Paul D.P. , Easton Douglas F. 
Published: September 2006

AbstractDisease association studies often test large numbers of markers, and various methods have been proposed to correct for multiple testing. In this paper, we propose an admixture maximum likelihood approach that estimates both the proportion of associated single nucleotide polymorphisms (SNPs) and their typical effect size. We assessed this method and compared it with several previously proposed approaches by simulation. The maximum likelihood approach performed similarly to or better than all other tests across a wide range of alternative hypotheses. The rank truncated product method also had good power, though somewhat inferior to the maximum likelihood approach in most cases. A simple Bonferroni correction performed best only when the number of associated SNPs was small.Genet.Epidemiol. 2006. © 2006 Wiley‐Liss, Inc.
Microglia instruct subventricular zone neurogenesis
Authors: Walton Noah M. , Sutter Benjamin M. , Laywell Eric D. , Levkoff Lindsay H. , Kearns Sean M. , Marshall Gregory P. , Scheffler Bjorn , Steindler Dennis A. 
Published: September 2006

AbstractMicroglia are increasingly implicated as a source of non‐neural regulation of postnatal neurogenesis and neuronal development. To evaluate better the contributions of microglia to neural stem cells (NSCs) of the subventricular neuraxis, we employed an adherent culture system that models the continuing proliferation and differentiation of the dissociated neuropoietic subventricular tissues. In this model, neuropoietic cells retain the ability to self‐renew and form multipotent neurospheres, but progressively lose the ability to generate committed neuroblasts with continued culture. Neurogenesis in highly expanded NSCs can be rescued by coculture with microglial cells or microglia‐conditioned medium, indicating that microglia provide secreted factor(s) essential for neurogenesis, but not NSC maintenance, self‐renewal, or propagation. Our findings suggest an instructive role for microglial cells in contributing to postnatal neurogenesis in the largest neurogenic niche of the mammalian brain. © 2006 Wiley‐Liss, Inc.
Phenotypic and functional characteristics of mesenchymal stem cells differentiated along a Schwann cell lineage
Authors: Caddick Jenny , Kingham Paul J. , Gardiner Natalie J , Wiberg Mikael , Terenghi Giorgio 
Published: September 2006

AbstractWe have investigated the phenotypic and bioassay characteristics of bone marrow mesenchymal stromal cells (MSCs) differentiated along a Schwann cell lineage using glial growth factor. Expression of the Schwann cell markers S100, P75, and GFAP was determined by immunocytochemical staining and Western blotting. The levels of the stem cell markers Stro‐1 and alkaline phosphatase and the neural progenitor marker nestin were also examined throughout the differentiation process. The phenotypic properties of cells differentiated at different passages were also compared. In addition to a phenotypic characterization, the functional ability of differentiated MSCs has been investigated employing a co‐culture bioassay with dissociated primary sensory neurons. Following differentiation, MSCs underwent morphological changes similar to those of cultured Schwann cells and stained positively for all three Schwann cell markers. Quantitative Western blot analysis showed that the levels of S100 and P75 protein were significantly elevated upon differentiation. Differentiated MSCs were also found to enhance neurite outgrowth in co‐culture with sensory neurons to a level equivalent or superior to that produced by Schwann cells. These findings support the assertion that MSCs can be differentiated into cells that are Schwann cell‐like in terms of both phenotype and function. © 2006 Wiley‐Liss, Inc.
On the winter evolution of snow thermophysical properties over land‐fast first‐year sea ice
Authors: Langlois Alexandre , Mundy C. J. , Barber David G. 
Published: September 2006

AbstractThe geophysical, thermodynamic and dielectric properties of snow are important state variables that are known to be sensitive to Arctic climate variability and change. Given recent observations of changes in the Arctic physical system (Arctic Climate Impact Assessment, 2004), it is important to focus on the processes that give rise to variability in the horizontal, vertical and temporal dimensions of the life‐history of snow on sea ice. The objectives in this study are to present these ‘state’ variables and to investigate the processes that govern variability in the vertical, horizontal and temporal dimension by using a case study over land‐fast first‐year sea ice for the period December 2003 to June 2004.Results from two sampling areas (thin and thick snowpacks) show that differences in snowpack thickness can substantially change the vertical and temporal evolution of snow properties. During the late fall and early winter (cooling period) we measured no significant changes in the physical properties, except for thin snow‐cover salinity, which decreased throughout the period. Fall‐snow desalination was only observed under thin snowpacks with a rate of −0·12 ppt day−1. Significant changes occurred in the late winter and early spring (warming period), especially for snow grain size. Snow grain kinetic growth of 0·25–0·48 mm·day−1 was measured coincidently with increasing salinity and wetness for both thin and thick snowpacks. Copyright © 2006 John Wiley & Sons, Ltd.
Development and validation of a reversed‐phase HPLC method for monitoring of synthetic reactions during the manufacture of a key intermediate of an anti‐hypertensive drug
Authors: Rao Ramisetti Nageswara , Nagaraju Dongari , Jena Nivedita , Kumaraswamy Gullapalli 
Published: September 2006

AbstractA reversed‐phase high‐performance liquid‐chromatographic method for monitoring of reactions involved in process development of a key intermediate of antihypertensive drugs, e.g, doxazosin mesylate, prazosin, alfuzosin, terazosin, etc., has been developed and validated. The HPLC profiles of impurities of 4‐amino‐2‐chloro‐6,7‐dimethoxyquinazoline were used as fingerprints to follow the synthetic procedures in the manufacturing unit. The separation was accomplished on an Inertsil ODS‐3 column with isocratic elution using acetonitrile‐ammonium acetate (10 mM; pH 4.0; 50:50 v/v) as mobile phase and a photodiode array detector set at 240 nm at ambient temperature. The method was validated with respect to accuracy, precision, linearity, and limits of detection and quantification. The method could detect the impurities at a level of 0.01 to 0.20 μg/mL and it was found to be suitable not only for monitoring of reactions but also for quality assurance of 4‐amino‐2‐chloro‐6,7‐dimethoxyquinazoline.
Alzheimer's disease presenting as corticobasal syndrome
Authors: Chand Pratap , Grafman Jordan , Dickson Dennis , Ishizawa Keisuke , Litvan Irene 
Published: September 2006

AbstractA 60‐year‐old man presented with slowly progressive left hemi‐Parkinsonism, left hand apraxia, myoclonus, dystonia, visuospatial disturbances, and alien limb phenomenon, resembling corticobasal syndrome. Eight years later, neuropathology revealed features of Alzheimer's disease, with asymmetrical (right more than left) cortical tau burden with image analysis. The videotaped clinical features, neuropsychological aspects, and neuropathological correlates are presented and discussed. © 2006 Movement Disorder Society
Density functional computations of 99Ru chemical shifts: relativistic effects, influence of the density functional, and study of solvent effects on fac—[Ru(CO)3I3]−
Authors: Autschbach Jochen , Zheng Shaohui 
Published: September 2006

AbstractSolvent effects on the 99Ru NMR chemical shift of the complex fac—[Ru(CO)3I3]− are investigated computationally using density functional theory. Further, benchmark calculations of the 99Ru shift for a set of ten Ru complexes have been performed in order to calibrate the computational model and to determine the importance of relativistic effects on the 99Ru nuclear magnetic shielding and on the chemical shift. A computational model for fac—[Ru(CO)3I3]− that includes both explicit solvent molecules and a continuum model is shown to yield the best agreement with experiment. Relativistic corrections are shown to be of minor importance for determining 99Ru chemical shifts. On the other hand, the nature of the density functional is of importance. In agreement with literature data for ligand trends of 99Ru chemical shifts, the chemical shift range for different solvents is also best reproduced by a hybrid functional. Copyright © 2006 John Wiley & Sons, Ltd.
Direct NMR resonance assignments of the active site histidine residue in Escherichia coli thioesterase I/protease I/lysophospholipase L1
Authors: Wu Wen‐Jin , Tyukhtenko Sergiy I. , Huang Tai‐Huang 
Published: September 2006

AbstractOwing to the hydrogen‐bond interaction and rapid exchange rate with the bulk water, the transverse relaxation time for the Nδ1H proton of the catalytic histidine in Escherichia coli thioesterase I/protease I/lysophospholipase L1 (TEP‐I) is rather short. Because of its catalytic importance, it is desirable to detect and assign this proton resonance. In this paper, we report the first direct NMR correlation between the short‐lived Nδ1H proton and its covalently attached Nδ1–nitrogen of the catalytic His157 residue in E. coli thioesterase/protease I. We have used gradient‐enhanced jump‐return spin‐echo HMQC (GE‐JR SE HMQC) to obtain a direct correlation between the short‐lived Nδ1H proton and its covalently attached Nδ1–nitrogen. The sensitivity of detection for the short‐lived Nδ1H proton was enhanced substantially by improved water suppression, in particular, the suppression of radiation damping via pulsed field gradients. Copyright © 2006 John Wiley & Sons, Ltd.
Malabsorption syndrome with and without small intestinal bacterial overgrowth: A study on upper‐gut aspirate using 1H NMR spectroscopy
Authors: Bala Lakshmi , Ghoshal Uday Chand , Ghoshal Ujjala , Tripathi Pratima , Misra Asha , Gowda G.A. Nagana , Khetrapal C.L. 
Published: September 2006

AbstractBiochemicals in the upper‐gut aspirate in 31 patients with malabsorption syndrome (MAS) with and without small intestinal bacterial overgrowth (SIBO), and 10 disease‐free controls were analyzed using high‐resolution 1H‐NMR spectroscopy, and were correlated with the degree of SIBO and severity of MAS. Compared to controls, the patients had higher quantities (μmol/L: median [range]) of total bile acids/cholesterol (2000 [0–12000] vs. 300 [0–600]), lactate (700 [0–5200] vs. nil [0–30]), acetate (200 [0–6500] vs. 20 [0–200]), and formate (80 [0–900] vs. nil [0–50]) (P < 0.01, Mann‐Whitney U‐test). However, amino acids and glucose were comparable in both. Quantities (μmol/L: median [range]) of acetate (1330 [220–6500] vs. 100 [0–1430]), lactate (1430 [670–3300] vs. 300 [0–5200]), formate (360 [0–600] vs. 25 [0–800]), and unconjugated bile acids (500 [40–600] vs. 10 [0–300]) were higher in MAS patients with SIBO than those without SIBO (P < 0.01, Mann‐Whitney U‐test, for all). In patients with MAS the quantity of acetate positively correlated with the degree of SIBO, and unconjugated bile acids correlated with the degree of steatorrhoea (Spearman's rank correlation coefficient, two‐tailed, P < 0.05: 0.46 and 0.52, respectively). This study demonstrates the bacterial production of metabolites and deconjugation of bile acids in patients with MAS. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Improvement of reduction method combined with sub‐domain scheme in large‐scale problem
Authors: Kim Hyungi , Cho Maenghyo 
Published: September 2006

AbstractFor a few decades, various approximate techniques have been developed to calculate the eigenvalues in a reduced manner. In order to construct reliable reduced systems it is essential to select the proper primary degrees of freedom (PDOFs). Unless the PDOFs are selected properly, the selection of PDOFs might be localized and the eigenvalue prediction might emphasize excessively the lower modes or lose the important modes. Moreover, sometimes, it takes considerable amount of computing time to construct a reduced system in large‐scale problem. These troubles in constructing reduced system can be avoided by applying reduction scheme in sub‐domain level. After dividing global system into a number of sub‐domains, reduced system which has only the PDOFs is constructed in each sub‐domain. This paper presents new algorithms to construct efficient reduction system through three different schemes. They are version 1, version 2 and version 3 systems. The version 3 system is constructed by combining the advantages of the version 1 and the version 2 systems. Numerical examples demonstrate that the proposed version 3 method saves computational cost effectively and provides a reduced system which can predict accurate eigenvalues of global system. Copyright © 2006 John Wiley & Sons, Ltd.
Advances in plant proteomics
Authors: Chen Sixue , Harmon Alice C. 
Published: September 2006

AbstractWith the avalanche of genomic information and improvements in analytical technology, proteomics is becoming increasingly important for the study of many different aspects of plant functions. Since proteins serve as important components of major signaling and biochemical pathways, studies at protein levels are essential to reveal molecular mechanisms underlying plant growth, development, and interactions with the environment. The plant proteome is highly complex and dynamic. Although great strides need to be taken towards the ultimate goal of characterizing all the proteins in a proteome, current technologies have provided immense opportunities for high‐throughput proteomic studies that have gone beyond simple protein identification to analyzing various functional aspects, such as quantification, PTM, subcellular localization, and protein–protein interactions. In this review of plant proteomics, advances in protein fractionation, separation, and MS will be outlined. Focus will be on recent development in functional analysis of plant proteins, which paves the way towards the comprehensive integration with transcriptomics, metabolomics, and other large scale “‐omics” into systems biology.
Proteomics and transfusion medicine: Future perspectives
Authors: Queloz Pierre‐Alain , Thadikkaran Lynne , Crettaz David , Rossier Joel S. , Barelli Stefano , Tissot Jean‐Daniel 
Published: September 2006

AbstractLimited number of important discoveries have greatly contributed to the progresses achieved in the blood transfusion; ABO histo‐blood groups, citrate as anticoagulant, fractionation of plasma proteins, plastic bags and apheresis machines. Three major types of blood products are transfused to patients: red cell concentrates, platelet concentrates and fresh frozen plasma. Several parameters of these products change during storage process and they have been well studied over the years. However, several aspects have completely been ignored; in particular those related to peptide and protein changes. This review presents what has been done using proteomic tools and the potentials of proteomics for transfusion medicine.
Aqueous polymer two‐phase systems: Effective tools for plasma membrane proteomics
Authors: Schindler Jens , Nothwang Hans Gerd 
Published: September 2006

AbstractPlasma membranes (PMs) are of particular importance for all living cells. They form a selectively permeable barrier to the environment. Many essential tasks of PMs are carried out by their proteinaceous components, including molecular transport, cell‐cell interactions, and signal transduction. Due to the key role of these proteins for cellular function, they take center‐stage in basic and applied research. A major problem towards in‐depth identification and characterization of PM proteins by modern proteomic approaches is their low abundance and immense heterogeneity in different cells. Highly selective and efficient purification protocols are hence essential to any PM proteome analysis. An effective tool for preparative isolation of PMs is partitioning in aqueous polymer two‐phase systems. In two‐phase systems, membranes are separated according to differences in surface properties rather than size and density. Despite their rare application to the fractionation of animal tissues and cells, they represent an attractive alternative to conventional fractionation protocols. Here, we review the principles of partitioning using aqueous polymer two‐phase systems and compare aqueous polymer two‐phase systems with other methods currently used for the isolation of PMs.
Proteomics as a route to identification of toxicity targets in environmental toxicology
Authors: Dowling Vera A. , Sheehan David 
Published: September 2006

AbstractEcotoxicology describes a three‐way relationship between ecosystems, chemical pollutants and living organisms. It is predicated on the fact that chemical pollution can exert toxic effects on organisms at the individual and population levels. These toxic effects may provide important information to supplement chemical analysis of environmental samples and aid in assessing the environmental quality of specific ecosystems. Traditionally, effects have been detected by means of biomarkers which, of necessity, were often molecules or processes known to be affected by pollutants. Proteomics provides a means of achieving high‐throughput analysis of effects on protein populations and sub‐populations with the potential to identify novel biomarkers. This review summarises the main approaches currently used in this area and assesses the potential of proteomics for identification of novel toxicity targets.
Expression, purification, and physicochemical characterization of theN‐terminal active site of human angiotensin‐I converting enzyme
Authors: Vamvakas Sotirios‐Spyridon M. , Leondiadis Leondios , Pairas George , Manessi‐Zoupa Evy , Spyroulias Georgios A. , Cordopatis Paul 
Published: September 2006

AbstractWe have cloned, over expressed, and purified one of the two catalytic domains (residues Ala361to Gly468, ACE‐N) of human somatic angiotensin‐I converting enzyme inEscherichia coli.This construct represents theN‐catalytic domain including the two binding motifs and the 23 amino acid spacers as well as some amino acid residues before and after the motifs that might help in correct conformation. The overexpressed protein was exclusively localized to insoluble inclusion bodies. Inclusion bodies were solubilized in an 8‐Murea buffer. Purification was carried out by differential centrifugation and gel filtration chromatography under denaturing conditions. About 12 mg of ACE‐N peptide per liter of bacterial culture was obtained. The integrity of recombinant protein domain was confirmed by ESI/MS. Structural analysis using CD spectroscopy has shown that, in the presence of TFE, the ACE‐N protein fragment has taken a conformation, which is consistent with the one found in testis ACE by X‐ray crystallography. This purification procedure enables the production of an isotopically labeled protein fragment for structural studying in solution by NMR spectroscopy. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd.
Impurity induced inter‐tube conductance in double‐wall carbon nanotubes
Authors: Uryu Seiji , Ando Tsuneya 
Published: September 2006

AbstractInter‐tube conductance in finite‐length double‐wall carbon nanotubes with impurities is numerically studied. In the absence of impurities the conductance drastically decreases due to cancellation of inter‐tube coupling at different sites when the edges of the double‐wall region are smoothed. This suppression is reduced in the presence of impurities and the averaged conductance increases with increase of the length. This indicates that irregular position dependence of inter‐tube coupling caused by impurities induces inter‐tube transfer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Thermal effects in Raman spectra of hexagonal boron nitride and nanotube‐containing boron nitride soot
Authors: Arutyunyan N. R. , Obraztsova E. D. , Silly M. , Jaffrennou P. , Attal‐Tretout B. , Loiseau A. , Chuvilin A. L. 
Published: September 2006

AbstractThe temperature‐induced changes in Raman spectra of two BN‐based materials: a hexagonal boron nitride and soot with single‐wall BN nanotubes, have been measured in temperature range 77–600 K in course of heating in the oven/cryostat cell. A nonlinear temperature dependence of the tangential Raman mode position (being at 1366 cm–1 at room temperature) has been observed for both materials. In the temperature range 350–600 K a linear approximation of the tangential Raman mode shifting was applicable. The measured rates were –0.014 cm–1/K (for h‐BN) and –0.027 cm–1/K (for the nanotube‐containing sample). The effects of the oven and laser heating have been compared. Under the laser heating with the same power density the nanotube‐containing soot demonstrated much bigger shifts (up to 30 cm–1) than h‐BN. The data obtained are useful for in‐situ diagnostics of different BN‐based phases in course of synthesis. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitons in carbon nanotubes
Authors: Maultzsch J. , Pomraenke R. , Reich S. , Chang E. , Prezzi D. , Ruini A. , Molinari E. , Strano M. S. , Thomsen C. , Lienau C. 
Published: September 2006

AbstractWe present two‐photon excitation luminescence experiments on carbon nanotubes which show the excitonic origin of the optical excitations. The two‐photon allowed exciton state, which has even parity under rotation about the U‐axis, is roughly 300 meV above the one‐photon active, odd‐parity state. This indicates exciton binding energies on the order of 400 meV for nanotubes with diameters around 8 Å. Ab‐initio calculations of the exciton wavefunctions and energies are in good agreement with our experimental results, confirming the predictions on the symmetry of the exciton states. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)