bluuebunny/crossref_metadata_2025_split huggingface dataset:
An ab initio simulation of the UV/visible spectra of N‐benzylideneaniline dyes
Authors: Jacquemin Denis , Laurent Adèle D. , Perpète Eric A. , André Jean‐Marie 
Published: July 2009

AbstractThe structural parameters and the absorption spectra of more than thirty N‐benzylideneaniline dyes have been determined with a theoretical scheme combining the time‐dependent density functional theory and the polarizable continuum model. For the unsubstituted molecule, the PBE0 hybrid nicely reproduces both the measured structural parameters and the absorption spectrum, and we demonstrate that the nature of the two first transitions is reversed compared with azobenzene. For the set of substituted compounds, the average TD‐DFT error (0.19 eV), that can be significantly reduced by a simple statistical treatment, mainly originates in the charge‐transfer states of push–pull derivatives, whereas local transitions are accurately modeled. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009
Changes in 13C/12C of oil palm leaves to understand carbon use during their passage from heterotrophy to autotrophy
Authors: Lamade Emmanuelle , Setiyo Indra Eko , Girard Sébastien , Ghashghaie Jaleh 
Published: July 2009

AbstractThe carbon isotope composition of leaf bulk organic matter was determined on the tropical tree Elaeis guineensis Jacq. (oil palm) in North Sumatra (Indonesia) to get a better understanding of the changes in carbon metabolism during the passage from heterotrophy to autotrophy of the leaves. Leaf soluble sugar (sucrose, glucose and fructose) contents, stomatal conductance and dark respiration, as well as leaf chlorophyll and nitrogen contents, were also investigated. Different growing stages were sampled from leaf rank −6 to rank 57. The mean values for the δ13C of bulk organic matter were −29.01 ± 0.9‰ for the leaflets during the autotrophic stage, −27.87 ± 1.08‰ for the petioles and −28.17 ± 1.09‰ for the rachises, which are in the range of expected values for a C3 plant. The differences in δ13C among leaf ranks clearly revealed the changes in the origin of the carbon source used for leaf growth. Leaves were 13C‐enriched at ranks below zero (around −27‰). During this period, the ‘spear’ leaves were completely heterotrophic and reserves from storage organs were mobilised for the growth of these young emerging leaves. 13C‐depletion was then observed when the leaf was expanding at rank 1, and there was a continuous decrease during the progressive passage from heterotrophy until reaching full autotrophy. Thereafter, the δ13C remained more or less constant at around −29.5‰. Changes in sugar content and in δ13C related to leaf ranks showed an interesting similarity of the passage from heterotrophy to autotrophy of oil palm leaves to the budburst of some temperate trees or seed germination reported in the literature. Copyright © 2009 John Wiley & Sons, Ltd.
Should baseline be a covariate or dependent variable in analyses of change from baseline in clinical trials?
Authors: Liu Guanghan F. , Lu Kaifeng , Mogg Robin , Mallick Madhuja , Mehrotra Devan V. 
Published: July 2009

AbstractIn randomized clinical trials, a pre‐treatment measurement is often taken at baseline, and post‐treatment effects are measured at several time points post‐baseline, say t=1, …, T. At the end of the trial, it is of interest to assess the treatment effect based on the mean change from baseline at the last time point T. We consider statistical methods for (i) a point estimate and 95 per cent confidence interval for the mean change from baseline at time T for each treatment group, and (ii) a p‐value and 95 per cent confidence interval for the between‐group difference in the mean change from baseline. The manner in which the baseline responses are used in the analysis influences both the accuracy and the efficiency of items (i) and (ii). In this paper, we will consider the ANCOVA approach with change from baseline as a dependent variable and compare that with a constrained longitudinal data analysis (cLDA) model proposed by Liang and Zeger (Sankhya: Indian J. Stat. (Ser B) 2000; 62:134–148), in which the baseline is modeled as a dependent variable in conjunction with the constraint of a common baseline mean across the treatment groups. Some drawbacks of the ANCOVA model and potential advantages of the cLDA approach are discussed and illustrated using numerical simulations. Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of the relationship between longitudinal gene expressions and ordered categorical event data
Authors: Rajicic Natasa , Finkelstein Dianne M. , Schoenfeld David A. 
Published: July 2009

AbstractThe NIH project ‘Inflammatory and Host Response to Injury’ (Glue) is being conducted to study the changes in the body over time in response to trauma and burn. Patients are monitored for changes in their clinical status, such as the onset of and recovery from organ failure. Blood samples are drawn over the first days and weeks after the injury to obtain gene expression levels over time. Our goal was to develop a method of selecting genes that differentially expressed in patients who either improved or experienced organ failure. For this, we needed a test for the association between longitudinal gene expressions and the time to the occurrence of ordered categorical outcomes indicating recovery, stable disease, and organ failure. We propose a test for which the relationship between the gene expression and the events is modeled using the cumulative proportional odds model that is a generalization of the pooling repeated observation method. Given the high‐dimensionality of the microarray data, it was necessary to control for the multiplicity of the testing. To control for the false discovery rate (FDR), we applied both a permutational approach as well as Efron's empirical estimation method. We explore our method through simulations and provide the analysis of the multi‐center, longitudinal study of immune response to inflammation and trauma (http://www.gluegrant.org). Copyright © 2009 John Wiley & Sons, Ltd.
Sample sizes for a robust ranking and selection of genes in microarray experiments
Authors: Matsui Shigeyuki , Oura Tomonori 
Published: July 2009

AbstractThe main role of high‐throughput microarrays today is screening of relevant genes from a large pool of candidate genes. For prioritizing genes for subsequent studies, gene ranking based on the strength of the association with the phenotype is a relevant statistical output. In this article, we propose sample size calculations based on gene ranking and selection using the non‐parametric Mann–Whitney–Wilcoxon statistic in microarray experiments. The use of the non‐parametric statistic is expected to be advantageous in robustification in gene ranking for the deviation from normality and for possible scale change by using different platforms such as polymerase chain reaction‐based platforms in subsequent studies in gene expression data. Application to the data set from a clinical study for lymphoma is given. Copyright © 2009 John Wiley & Sons, Ltd.
Long-Term, Stable Differentiation of Human Embryonic Stem Cell-Derived Neural Precursors Grafted into the Adult Mammalian Neostriatum
Authors: Nasonkin Igor , Mahairaki Vasiliki , Xu Leyan , Hatfield Glen , Cummings Brian J. , Eberhart Charles , Ryugo David K. , Maric Dragan , Bar Eli , Koliatsos Vassilis E. 
Published: July 2009

Abstract
Stem cell grafts have been advocated as experimental treatments for neurological diseases by virtue of their ability to offer trophic support for injured neurons and, theoretically, to replace dead neurons. Human embryonic stem cells (HESCs) are a rich source of neural precursors (NPs) for grafting, but have been questioned for their tendency to form tumors. Here we studied the ability of HESC-derived NP grafts optimized for cell number and differentiation stage prior to transplantation, to survive and stably differentiate and integrate in the basal forebrain (neostriatum) of young adult nude rats over long periods of time (6 months). NPs were derived from adherent monolayer cultures of HESCs exposed to noggin. After transplantation, NPs showed a drastic reduction in mitotic activity and an avid differentiation into neurons that projected via major white matter tracts to a variety of forebrain targets. A third of NP-derived neurons expressed the basal forebrain-neostriatal marker dopamine-regulated and cyclic AMP-regulated phosphoprotein. Graft-derived neurons formed mature synapses with host postsynaptic structures, including dendrite shafts and spines. NPs inoculated in white matter tracts showed a tendency toward glial (primarily astrocytic) differentiation, whereas NPs inoculated in the ventricular epithelium persisted as nestin(+) precursors. Our findings demonstrate the long-term ability of noggin-derived human NPs to structurally integrate tumor-free into the mature mammalian forebrain, while maintaining some cell fate plasticity that is strongly influenced by particular central nervous system (CNS) niches.
3D Timelapse Analysis of Muscle Satellite Cell Motility
Authors: Siegel Ashley L. , Atchison Kevin , Fisher Kevin E. , Davis George E. , Cornelison D.D.W. 
Published: July 2009

AbstractSkeletal muscle repair and regeneration requires the activity of satellite cells, a population of myogenic stem cells scattered throughout the tissue and activated to proliferate and differentiate in response to myotrauma or disease. While it seems likely that satellite cells would need to navigate local muscle tissue to reach damaged areas, relatively little data on such motility exist, and most studies have been with immortalized cell lines. We find that primary satellite cells are significantly more motile than myoblast cell lines, and that adhesion to laminin promotes primary cell motility more than fourfold over other substrates. Using timelapse videomicroscopy to assess satellite cell motility on single living myofibers, we have identified a requirement for the laminin-binding integrin α7β1 in satellite cell motility, as well as a role for hepatocyte growth factor in promoting directional persistence. The extensive migratory behavior of satellite cells resident on muscle fibers suggests caution when determining, based on fixed specimens, whether adjacent cells are daughters from the same mother cell. We also observed more persistent long-term contact between individual satellite cells than has been previously supposed, potential cell-cell attractive and repulsive interactions, and migration between host myofibers. Based on such activity, we assayed for expression of “pathfinding” cues, and found that satellite cells express multiple guidance ligands and receptors. Together, these data suggest that satellite cell migration in vivo may be more extensive than currently thought, and could be regulated by combinations of signals, including adhesive haptotaxis, soluble factors, and guidance cues.
Isolation of Neural Crest Derived Chromaffin Progenitors from Adult Adrenal Medulla
Authors: Chung Kuei-Fang , Sicard Flavie , Vukicevic Vladimir , Hermann Andreas , Storch Alexander , Huttner Wieland B. , Bornstein Stefan R. , Ehrhart-Bornstein Monika 
Published: July 2009

Abstract
Chromaffin cells of the adrenal medulla are neural crest-derived cells of the sympathoadrenal lineage. Unlike the closely-related sympathetic neurons, a subpopulation of proliferation-competent cells exists even in the adult. Here, we describe the isolation, expansion, and in vitro characterization of proliferation-competent progenitor cells from the bovine adrenal medulla. Similar to neurospheres, these cells, when prevented from adherence to the culture dish, grew in spheres, which we named chromospheres. These chromospheres were devoid of mRNA specific for smooth muscle cells (MYH11) or endothelial cells (PECAM1). During sphere formation, markers for differentiated chromaffin cells, such as phenylethanolamine-N-methyl transferase, were downregulated while neural progenitor markers nestin, vimentin, musashi 1, and nerve growth factor receptor, as well as markers of neural crest progenitor cells such as Sox1 and Sox9, were upregulated. Clonal analysis and bromo-2′-deoxyuridine-incorporation analysis demonstrated the self-renewing capacity of chromosphere cells. Differentiation protocols using NGF and BMP4 or dexamethasone induced neuronal or endocrine differentiation, respectively. Electrophysiological analyses of neural cells derived from chromospheres revealed functional properties of mature nerve cells, such as tetrodotoxin-sensitive sodium channels and action potentials. Our study provides evidence that proliferation and differentiation competent chromaffin progenitor cells can be isolated from adult adrenal medulla and that these cells might harbor the potential for the treatment of neurodegenerative diseases, such as Parkinson's disease.
Performance of bolted angle connections in progressive collapse of steel frames
Authors: Pirmoz Akbar 
Published: July 2009

AbstractThis paper is mainly focused on the behaviour of bolted top‐seat angle connections with double web angles, categorized as partially restrained connections, in progressive collapse of semi‐rigid steel frames due to sudden column loss. The main characteristics of this type of loading are declared and the effect of the imposed boundary conditions on the motivated elements is depicted. To study the performance of frame connections under these conditions, refined nonlinear finite element modelling technique is used. The models are created based on the previous experimental studies and their accuracy is examined through a comparison to the results of these tests. New models are created under conditions of the progressive collapse and the behaviour of the connections is studied. The study showed that due to the applied boundary conditions, the connections behave stiffer and show a higher moment capacity. Based on the results of the numerical models, equations are presented to estimate the moment‐rotation response of the studied connections under progressive collapse conditions based on the beam and connection mechanical and geometrical properties and the connection rotation. Copyright © 2009 John Wiley & Sons, Ltd.
A case study of the structural responses of a tall building in Singapore subjected to close‐in detonations
Authors: Li Bing , Pan Tso‐Chien , Nair Anand 
Published: July 2009

AbstractThe response of tall buildings has been a major concern in metropolitan cities, especially with the recent surge in extreme activities targeted at structures with viable commercial values. This paper discusses a study carried out on the structural behaviour of a 2D frame, modelled to represent a tall building with ABAQUS. The model frame was subjected to a charge of the equivalent weight of 1 ton of TNT but placed at two varying cases of 5 and 10‐m standoff distances. Plane‐strain elements that incorporate the feature of material nonlinearity were utilized to model the structural components of the building and the simulated blast overpressures were obtained from the CONWEP software. The effects of large deformations of beams and columns corresponding to the short time loading duration depicted by the explosions were analysed from a local perspective. The extent of the damage is based on a local index defined as the ratio of curvatures. These local indices are consequently used to determine the possibility of disproportionate collapse of the frame from a global perspective. Finally, the provision of more ductile structural detailing is recommended to enhance the structural integrity of the building, increasing its resilience against blast attacks. Copyright © 2009 John Wiley & Sons, Ltd.
Male gender as a favorable prognostic factor in pregnancies with enlarged nuchal translucency
Authors: Timmerman E. , Pajkrt E. , Bilardo C. M. 
Published: July 2009

AbstractObjectiveThe aim of this study was to investigate the influence of fetal gender on pregnancy outcome in fetuses with enlarged nuchal translucency (NT).MethodsPregnancy outcomes of all women who underwent an NT measurement at our institution between January 2000 and November 2007 were retrospectively reviewed. Separate analyses were performed for fetuses with normal and with enlarged (≥ 95th percentile) NT.ResultsA normal NT was measured in 3637 males (51.4%) and 3435 females (48.6%). Of the fetuses with enlarged NT 365 were males (57.4%) and 271 females (42.6%) (P = 0.001). In this group a normal pregnancy outcome—of those pregnancies for which the outcome was known—was registered for 187/332 (56.3%) of the male fetuses and 98/249 (39.4%) of the female fetuses (P < 0.001; relative risk (RR) for adverse outcome for male gender, 0.72). Eighty percent of the chromosomally normal male fetuses with an enlarged NT had an uneventful pregnancy outcome; this increased to 90% when only the male fetuses with NT measurements ≥ 95th percentile and < 99th percentile and normal karyotype were considered (RR for adverse outcome for male gender, 0.47).ConclusionIn a population of fetuses with enlarged NT there are significantly more males. Male fetuses with enlarged NT and normal chromosomes have an almost two‐fold greater chance of a favorable outcome than females. We believe that a minimal degree of NT enlargement in male fetuses without genetic or structural anomalies may be interpreted as a feature of accelerated growth or, alternatively, as a maturational delay of the cardiovascular system more common in males, leading to moderately increased nuchal fluid accumulation. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Effect of mifepristone on the corpus luteum in early pregnancy
Authors: Niinimäki M. , Ruokonen A. , Tapanainen J. S. , Järvelä I. Y. 
Published: July 2009

AbstractObjectiveThe antiprogestin mifepristone is widely used for medical termination of pregnancy (TOP). Previous studies have suggested that the mechanism of mifepristone is based on its action in the endometrium and myometrium. The aim of this study was to evaluate the possible effects of mifepristone on corpus luteum activity.MethodsThis was a prospective, longitudinal controlled study to which 20 patients undergoing medical TOP (study group) and 20 patients with normal ongoing pregnancy (control group) were recruited. Medical TOP was induced with 200 mg of mifepristone followed by 0.8 mg of misoprostol 2 days later. Three‐dimensional ultrasound examinations and hormone assays (progesterone, human chorionic gonadotropin, and 17‐hydroxyprogesterone) were performed in both groups on the day of, and 2 days after, administration of mifepristone. Total volume (vascularized + non‐vascularized) of the dominant (containing corpus luteum) and non‐dominant ovary and serum hormone levels were measured.ResultsAfter administration of mifepristone, a decrease in serum progesterone levels was observed with a simultaneous decrease in the non‐vascularized volume of the dominant ovary in the study group. No such changes were observed in the control group.ConclusionsThe observations indicate that, in addition to trophoblastic tissue, the corpus luteum is also the target of mifepristone. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Agreement between umbilical vein volume blood flow measurements obtained at the intra‐abdominal portion and free loop of the umbilical cord
Authors: Flo K. , Wilsgaard T. , Acharya G. 
Published: July 2009

AbstractObjectiveThe umbilical vein (UV) is a single vessel and theoretically the volume of blood flowing through it should be equal whether it is measured at the intra‐abdominal portion (IA) or a free loop of the umbilical cord (FL). However, the reported values vary considerably depending on the technique and site of measurement. Our objective was to investigate the correlation and agreement between UV volume blood flows (Quv) measured at the IA and FL.MethodsBlood flow velocities and inner diameter of the UV were measured cross‐sectionally at the IA and FL in 131 pregnant women at 22–24 weeks' gestation, and in 53 of them longitudinally at 4‐weekly intervals until delivery. For each sampling site, the Quv was calculated as: 0.5 × time‐averaged maximum velocity × π × (UV diameter/2)2.ResultsThe mean Quv measured at the IA (61.5 ± 23.3 mL/min) and FL (60.7 ± 17.6 mL/min) cross‐sectionally in 131 fetuses at 22–24 weeks of gestation were similar, but the bivariate correlation between them was not strong (r = 0.38; P < 0.0001) and the intraclass correlation coefficient (ICC) was 0.37 (95% CI, 0.21–0.51). When the agreement between 131 pairs of Quv measurements was tested with Bland–Altman analysis, the mean of the ratio IA‐Quv/FL‐Quv was found to be 1.05 (i.e. IA‐Quv exceeded FL‐Quv on average by 5%) with 95% limits of agreement of 0.31–1.78. In the longitudinal analysis of 232 pairs of Quv measurements from 53 fetuses at 22–40 weeks, the mean Quv obtained at the IA and FL were similar, i.e. 164 ± 87 (range, 25–484) mL/min vs. 159 ± 82 (range, 30–470) mL/min, and the correlation between them, assessed after grouping the observations in five different gestational age groups of 4‐week intervals, was slightly better (r = 0.45–0.62; P < 0.0001). The ICC for the Quv measurements obtained at the two sites ranged from 0.38 to 0.54. The mean of the ratio IA‐Quv/FL‐Quv was 1.07 (i.e. IA‐Quv exceeded FL‐Quv on average by 7%), with 95% limits of agreement of 0.39–1.75.ConclusionAverage Quv measured at the IA and FL was similar, but the agreement between individual pairs of measurements was not good enough to be able to use them interchangeably. Therefore, any clinical application of Quv measurement would require standardization of the technique, strict adherence to methodology and use of appropriate reference ranges for it to be useful. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Preparation and Properties of Sodium Dimethyldithioarsinate Dihydrate, Me2AsS2Na·2H2O, and Palladium(II) Dimethyldithioarsinate, (Me2AsS2)2Pd
Authors: Ioannou Panayiotis V. , Vachliotis Dimitris G. , Nastopoulos Vassilios , Tasiopoulos Anastasios J. 
Published: July 2009

AbstractPalladium(II) acetate in non‐deaerated chloroform splits Bunsen’s cacodyl disulfide, Me2As(S)–S–AsMe2, giving the complex (Me2AsS2)2Pd, slightly soluble in chloroform, and the arsonium ion Me2As:+. However, after a few minutes the complex reacted giving Me2As(S)–O–As(S)Me2 and other, so far unidentified compounds. Therefore, the complex (Me2AsS2)2Pd was prepared from sodium dimethyldithioarsinate dihydrate, Me2AsS2Na·2H2O, and palladium(II) acetate. (Me2AsS2)2Pd reacts with PdII and Ph3P in a different way compared to other (Me2AsS2)xM (M = heavy metal cation) and (Me2PS2)2Pd. The reaction of equimolar quantities of Me2AsS2Na·2H2O and Ph3P under argon involved four consecutive reactions with Me2As–O–AsMe2 and Me2AsS2Na as the final products. The salt Me2AsS2Na·2H2O has been structurally characterized: triclinic, P\bar{1}, a = 6.0285(2) Å, b = 6.5552(2) Å, c = 12.1480(4) Å, α = 98.282(2)ό, β = 93.994(3)ό, γ = 115.951(3)ό, V = 422.38(3) Å3, Z = 2, R1 = 0.0207, wR2 = 0.0414.