bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein C and S and inflammation in sickle cell disease
Authors: Schnog J.B. , Mac Gillavry M.R. , van Zanten A.P. , Meijers J.C.M. , Rojer R.A. , Duits A.J. , ten Cate H. , Brandjes D.P.M. 
Published: April 2004

AbstractReduced activity of naturally occurring anticoagulants (NOAC) protein C and protein S may contribute to vaso‐occlusion in sickle cell disease (SCD). We studied whether protein C and S are related to clinical vaso‐occlusion, hematological markers of disease severity (hemoglobin levels, leukocyte counts, and percentage of fetal hemoglobin), and inflammation in SCD. Protein C activity, protein S (free and total) antigen, endothelial activation markers (soluble vascular cell adhesion molecule‐1 [sVCAM‐1], von Willebrand antigen [vWF]), and high sensitive C‐reactive protein (hsCRP) levels were measured in 30 HbSS and 20 HbSC patients and in race‐matched HbAA controls. NOAC levels were reduced in patients, and endothelial activation markers and hsCRP were elevated (except vWF in HbSC patients). Protein C activity and vWF levels were lower in HbSC patients who experienced painful crises compared to HbSC patients who were clinically asymptomatic. No other differences were observed between patients who did and did not experience vaso‐occlusive events (painful crises, stroke, acute chest syndromes) or leg ulcers. A significant positive correlation between total protein S with hemoglobin levels and a significant negative correlation between total and free protein S and sVCAM‐1 were detected in HbSS patients. Except perhaps for protein C in relation to painful crises in HbSC patients, these markers were not associated with the occurrence of clinical events. The protein S, hemoglobin, and sVCAM‐1 associations may suggest decreased endothelial protein S production due to the more severe endothelial perturbation in HbSS patients with lower hemoglobin levels. Am. J. Hematol. 76:26–32, 2004. © 2004 Wiley‐Liss, Inc.
Morphology of polyimide fibers derived from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride and 4,4′‐oxydianiline
Authors: Zhang Qing‐Hua , Dai Mian , Ding Meng‐Xian , Chen Da‐Jun , Gao Lian‐Xun 
Published: April 2004

AbstractAs one member of high performance fibers, aromatic polyimide fibers possess many advantages, such as high strength, high modulus, high and low temperature resistance, and radiation resistance. However, the preparation of the high performance fibers is so difficult that the commercial fibers have not been produced except P84 with good flame retardancy. In this report, a polyimide was synthesized from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐oxydianiline (ODA) and the fibers were prepared from its solution by a dry‐jet wet‐spinning process. The formation of the as‐spun fibers in different coagulation bath composition was discussed. Scanning electron microscope (SEM) was employed to study the morphology of the as‐spun fibers. As a result, the remnant solvent existed in the as‐spun fibers generated from coagulation bath of alcohol and water. There were many fibrils and microvoids with the dimension of tens of nanometers in the fibers. One could observe the obvious fibrillation and the drawn fibers. The measurement for the mechanical properties of the fibers with a drawing ratio of 5.5 indicated that tensile strength and initial modulus were 2.4 and 114 GPa, respectively. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 669–675, 2004
Computational Investigation of Hydrogen Abstraction from 2‐Aminoethanol by the 1,5‐Dideoxyribose‐5‐yl Radical: A Model Study of a Reaction Occurring in the Active Site of Ethanolamine Ammonia Lyase
Authors: Semialjac Marija , Schwarz Helmut 
Published: April 2004

AbstractHydrogen abstraction from 2‐aminoethanol by the 5′‐deoxyadenosyl radical, which is formed upon CoC bond homolysis in coenzyme B12, was investigated by theoretical means with employment of the DFT (B3LYP) and ab initio (MP2) approaches. As a model system for the 5′‐deoxyadenosyl moiety the computationally less demanding 1,5‐dideoxyribose was employed; two conformers, which differ in ring conformation (C2‐ and C3‐endo), were considered. If hydrogen is abstracted from “free” substrate by the C2‐endo conformer of the 1,5‐dideoxyribose‐5‐yl radical, the activation enthalpy is 16.7 kcal mol−1; with the C3‐endo counterpart, the value is 17.3 kcal mol−1. These energetic requirements are slightly above the activation enthalpy limit (15 kcal mol−1) determined experimentally for the rate‐determining step of the sequence, that is, hydrogen delivery from 5′‐deoxyadenosine to the product radical. The activation enthalpy is lower when the substrate interacts with at least one amino acid from the active site. According to the computations, when a His model system partially protonates the substrate the activation enthalpy is 4.5 kcal mol−1 for the C3‐endo conformer and 5.8 kcal mol−1 for the C2‐endo counterpart. As hydrogen abstraction from the fully as well as the partially protonated substrate is preceded by the formation of quite stable encounter complexes, the actual activation barriers are around 13–15 kcal mol−1. A synergistic interaction of 2‐aminoethanol with two amino acids where His partially protonates the NH2 group and Asp partially deprotonates the OH group of the substrate results in an activation enthalpy of 12.4 kcal mol−1 for the C3‐endo conformer and 13.2 kcal mol−1 for the C2‐endo counterpart. However, if encounter complexes exist in the active site, the actual activation barriers are much higher (>25 kcal mol−1) than that reported for the rate‐determining step. These findings together with previous computations suggest that the energetics of the initial hydrogen abstraction decrease with an interaction of the substrate with only a protonating auxiliary, but for the rearrangement of the radical the synergistic effects of two auxiliaries are essential to pull the barrier below the limit of 15 kcal mol−1.
Predicting crashes in a model of evolving networks
Authors: Krause Andreas 
Published: April 2004

AbstractWe consider an evolving network of interacting species which exhibits self‐organization. The system is characterized by repeated crashes in which a large number of species are extinct and subsequent recoveries. We investigate the macroscopic properties of this system before such crashes, concentrating on the variance of the relative population sizes of species and its evolution over time. A simple score function is constructed to determine the probability of a crash within a certain time interval to be used as a predictor for crashes. © 2004 Wiley Periodicals, Inc. Complexity 9: 24–30, 2004
Navier‐Stokes Neutral and Plasma Fluid Modelling in 3D
Authors: Riemann J. , Borchardt M. , Schneider R. , Mutzke A. , Rognlien T. D. , Umansky M. 
Published: April 2004

AbstractThe 3D finite volume transport code BoRiS is applied to a system of coupled plasma and neutral fluid equations in a slab. Demonstrating easy implementation of new equations, a new parallel BoRiS version is tested on three different models for the neutral fluid – diffusive, parallel Navier‐Stokes and full Navier‐Stokes – and the results are compared to each other. Typical effects like density enhancement by ionization of recycled neutrals in front of a target plate can be seen and differences are linked to the neutral models in use. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Computational atomic physics for plasma edge modeling
Authors: Schultz D. R. , Krstic P. S. , Minami T. , Pindzola M. S. , Robicheaux F. J. , Colgan J. P. , Loch S. D. , Griffin D. C. , Ballance C. P. , Badnell N. R. , Summers H. P. 
Published: April 2004

AbstractAtomic processes play important roles in the physics of the edge plasma and in enabling diagnostics. In this paper we illustrate a number of recent projects undertaken to expand or remediate the existing atomic database required for modeling and related studies. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The influence of molecular dynamics on divertor detachment in TCV
Authors: Wischmeier M. , Pitts R. A. , Alfier A. , Andrebe Y. , Behn R. , Coster D. , Horacek J. , Nielsen P. , Pasqualotto R. , Reiter D. , Zabolotsky A. 
Published: April 2004

AbstractIf vibrationally excited molecules are discretised into individual species and proper account is taken of the toroidal geometry in simulating neutrals, some improvement can be made in simulating the anomalous detachment behaviour seen at the outer target of TCV single‐null lower L‐mode discharges. This contribution discusses the inclusion of these options into SOLPS5.0 (B2.5/Eirene) simulations of TCV discharges previously modelled with the SOLPS4.0 package, but demonstrates that current physics contained within the simulations is still by a large margin insufficient to describe the experimental measurements. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Upper beak truncation in chicken embryos with the cleft primary palate mutation is due to an epithelial defect in the frontonasal mass
Authors: MacDonald Mary E. , Abbott Ursula K. , Richman Joy M. 
Published: April 2004

AbstractIn this study, we used the chicken mutant strain known as cleft primary palate (cpp) to study the mechanisms of beak outgrowth. cpp mutants have complete truncation of the upper beak with normal development of the lower beak. Based on structural analysis and grafts of facial prominences, we localized the defect to the frontonasal mass and its derivatives. Several explanations that would account for the outgrowth defect were investigated, including abnormal expression of genes in the frontonasal epithelium, intrinsic defects in epithelium and/or mesenchyme defects in epithelial–mesenchymal signalling, a localized decrease in cell proliferation or a localized increase in programmed cell death. One of the genes expressed in the frontonasal epithelial growth zone, Fgf8, failed to down‐regulate and was maintained for at least 48 hr beyond the time when down‐regulation normally occurs. Recombination experiments further illustrated that the frontonasal mass epithelium was abnormal in the cpp mutants, whereas mutant mesenchyme was capable of normal outgrowth when combined with wild‐type epithelium. Cell proliferation was not decreased in mutant embryos nor was cell death initially increased. Later, at stages 31–32, when the prenasal cartilage begins directed outgrowth, there was an increase in cell death within the mutant upper but not lower beak cartilage. The cpp beak truncation, therefore, is due to an epithelial defect in the frontonasal mass that is coincident with a failure to down‐regulate expression of Fgf8. Developmental Dynamics 230:335–349, 2004. © 2004 Wiley‐Liss, Inc.
HMG box transcription factor gene Hbp1 is expressed in germ cells of the developing mouse testis
Authors: Smith James M. , Bowles Josephine , Wilson Megan , Koopman Peter 
Published: April 2004

AbstractHMG box containing protein 1 (HBP1) is a high mobility group domain transcriptional repressor that regulates proliferation in differentiated tissues. We have found mouse Hbp1 to be expressed strongly in the embryonic mouse testis from approximately 12.5 days post coitum, compared with low levels of expression in the embryonic ovary. Expression of Hbp1 is maintained in the developing testis beyond the onset of spermatogenesis after birth. Whole‐mount in situ hybridisation analysis showed that expression of Hbp1 in the XY gonad is localized within the developing testis cords, the precursors of the seminiferous tubules. Expression of Hbp1 is not apparent in testis cords of gonads from homozygous We mutant embryos, which lack germ cells. In situ hybridisation analysis on cryosectioned embryonic testis indicated that Hbp1 expression resembles that of the germ cell marker Oct4. We conclude that Hbp1 is up‐regulated specifically in germ cells of the developing XY gonad. The expression of Hbp1 in XY germ cells appears to correlate with the onset of mitotic arrest in these cells. Developmental Dynamics 230:366–370, 2004. © 2004 Wiley‐Liss, Inc.
Time course of programmed cell death in Ciona intestinalis in relation to mitotic activity and MAPK signaling
Authors: Tarallo Raffaella , Sordino Paolo 
Published: April 2004

AbstractProgrammed cell death (PCD) in the ascidian species Ciona intestinalis (Tunicata; Chordata) is investigated from early larvae to juvenile stages, by means of digoxigenin‐based terminal deoxynucleotidyl transferase‐mediated biotinylated UTP nick end labeling (TUNEL) technique. At first, PCD in the swimming larva affects trunk mesenchyme and central nervous system (CNS), then it participates extensively to metamorphosis, until it is restricted to developing organs of juveniles. Analysis of patterns of cell death and division in the larval CNS question old models on the genesis of the adult C. intestinalis brain. Upon performing immunochemical and functional assays for mitogen‐activated protein kinase (MAPK) kinase kinase‐1 (MEKK1), MAPK kinase 1/2 (MEK1/2), c‐Jun NH2‐terminal kinase (JNK), and dual phosphorylated extracellular regulated kinase 1/2 (dpERK1/2), the neurogenic competence of the larval brain appears to rely on a combinatorial regulation of PCD by the mitogen‐activated protein kinase signaling cascade. These results show that, in tunicates, PCD consists of a multistep program implicated in growth and patterning with various roles. Developmental Dynamics 230:251–262, 2004. © 2004 Wiley‐Liss, Inc.
Characterization of triacsin C inhibition of short‐, medium‐, and long‐chain fatty acid:CoA ligases of human liver
Authors: Vessey Donald A. , Kelley Michael , Warren Robert S. 
Published: April 2004

AbstractShort‐, medium‐, and long‐chain fatty acid:CoA ligases from human liver were tested for their sensitivity to inhibition by triacsin C. The short‐chain fatty acid:CoA ligase was inhibited less than 10% by concentrations of triacsin C as high as 80 μM. The two mitochondrial xenobiotic/medium‐chain fatty acid:CoA ligases (XM‐ligases), HXM‐A and HXM‐B, were partially inhibited by triacsin C, and the inhibitions were characterized by low affinity for triacsin C (KI values > 100 μM). These inhibitions were found to be the result of triacsin C competing with medium‐chain fatty acid for binding at the active site. The microsomal and mitochondrial forms of long‐chain fatty acid:CoA ligase (also termed long‐chain fatty acyl‐CoA synthetase, or long‐chain acyl‐CoA synthetase LACS) were potently inhibited by triacsin C, and the inhibition had identical characteristics for both LACS forms. Dixon plots of this inhibition were biphasic. There is a high‐affinity site with a KI of 0.1 μM that accounts for a maximum of 70% of the inhibition. There is also a low affinity site with a KI of 6 μM that accounts for a maximum of 30% inhibition. Kinetic analysis revealed that the high‐affinity inhibition of the mitochondrial and microsomal LACS forms is the result of triacsin C binding at the palmitate substrate site.The high‐affinity triacsin C inhibition of both the mitochondrial and microsomal LACS forms was found to require a high concentration of free Mg2+, with the EC50 for inhibition being 3 mM free Mg2+. The low affinity triacsin C inhibition was also enhanced by Mg2+. The data suggests that Mg2+ promotes triacsin C inhibition of LACS by enhancing binding at the palmitate binding site. In contrast, the partial inhibition of the XM‐ligases by triacsin C, which showed only a low‐affinity component, did not require Mg2+. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:100–106, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20009
Cardiotoxicity of doxorubicin/paclitaxel combination in rats: Effect of sequence and timing of administration
Authors: Saad Sherif Y. , Najjar Tawfeeg A. O. , Alashari Mouied 
Published: April 2004

AbstractThe higher incidence of cardiotoxicity of doxorubicin (DOX)/paclitaxel (PTX) combination compared with DOX alone remains to be a major obstacle against effective chemotherapeutic treatment. We investigated the effect of sequence and time interval between administration of both drugs on the severity of cardiotoxicity of the combination. Male Wistar rats were divided into seven groups. DOX was administeded intraperitoneally (ip) at a single dose of 5 mg kg−1 every other 2 days, 2 doses per week for a total cumulative dose of 20 mg kg−1. PTX was administered by an ip route at a dose of 20 mg kg−1 every other 2 days. Both drugs were injected either alone or sequentially in combination. In one case, DOX preceded PTX by 30 min and 24 h and in the other case, PTX preceded DOX by 30 min and 24 h. Cardiotoxicity was evaluated by both biochemical and histopathological examination, 48 h after the last DOX dose. DOX‐induced cardiotoxicity was manifested by abnormal biochemical changes including marked increases in serum creatine phosphokinase isoenzyme (CK‐MB), lactate dehydrogenase (LDH), glutathione peroxidase (GSH‐Px), and aspartate aminotransferase (AST) activity levels. Myocardial tissue from DOX‐treated rats showed significant increases in malondialdehyde (MDA) production and total nitrate/nitrite (NOx) levels, parallel with depletion of “endogenous antioxidant reserve,'' including GSH contents and GSH‐Px activity level. PTX treatment produced significant changes in the biochemical parameters measured by a lower magnitude than those changes produced by DOX alone. Combination of both drugs resulted in aggravation of DOX‐induced cardiotoxicity regardless the sequence and time interval between administration of either drug. Administration of PTX 30 min and 24 h after DOX treatment showed exaggeration of combination‐induced cardiotoxicity compared with the reverse sequence. This exacerbation was manifested by much more pronounced changes in serum and cardiac tissue parameters measured. Histopathological examination of ventricles of rat's heart revealed that DOX treatment produced myo‐cytolysis and myocardial necrosis. Administration of PTX following DOX treatment showed extensive myocardial necrosis compared with those rats treated with either DOX alone or the reverse sequence of administration. Moreover, rats treated with PTX 24 h after DOX treatment showed exaggeration of the combination‐induced cardiotoxicity. In conclusion, PTX might synergistically aggravate DOX‐induced cardiotoxicity. The effect might be much more pronounced with those rats treated with PTX 24 h after DOX treatment. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:78–86, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20012
Efficient synthesis of 6‐chloro‐3‐((2‐(S)‐azetidinyl)methoxy)‐5‐((E)‐2‐(2‐[18F]fluoropyridin‐4‐yl)vinyl)pyridine ([18F]NIDA 52289), a very high affinity radioligand for nicotinic acetylcholine receptors
Authors: Zhang Yi , Hall Andrew W. , Horti Andrew G. 
Published: April 2004

Abstract6‐Chloro‐3‐((2‐(S)‐azetidinyl)methoxy)‐5‐((E)‐2‐(2‐[18F]fluoropyridin‐4‐yl)vinyl)pyridine ([18F]NIDA 52289), a very high affinity radioligand for studying nicotinic acetylcholine receptors (nAChRs) by positron‐emission tomography, was synthesized through Kryptofix 222 assisted no‐carrier‐added nucleophilic [18F]fluorination of 6‐chloro‐3‐((1‐(tert‐butoxycarbonyl)‐2‐(S)‐azetidinyl)methoxy)‐5‐((E)‐2‐(2‐bromopyridin‐4‐yl)vinyl)pyridine, followed by acidic deprotection. The overall radiochemical yield of the radiosynthesis was 10% (non‐decay‐corrected), the specific radioactivity was in the range of 93–326 GBq/µmol (2.5–8.8 mCi/µmol) and the radiochemical purity was greater than 99%. Copyright © 2004 John Wiley & Sons, Ltd.
Woman with a 26‐year history of parkinsonism, supranuclear ophthalmoplegia, and loss of postural reflexes
Authors: Gordon Paul H. , Fahn Stanley , Chin Steven , Golbe Lawrence I. , Lynch Timothy , Eidelberg David 
Published: April 2004

AbstractA woman who had her first serious fall at age 48 years subsequently developed neurological symptoms. Her case is described, differential diagnoses are presented, pathology is discussed, and a final diagnosis is reached. © 2004 Movement Disorder Society
A new path‐following constraint for strain‐softening finite element simulations
Authors: Lorentz E. , Badel P. 
Published: April 2004

AbstractThe application of strain‐softening constitutive relations to model the failure modes of real‐life structures is faced to numerical difficulties related to instabilities that appear as sharp snap‐backs of the structural response. A path‐following method has to complement the solution algorithm to achieve convergence despite these critical points. Because of the sharpness of the snap‐backs, it is believed essential that the path‐following constraint distinguish between a purely elastic unloading and a dissipative path. For that purpose, a new constraint based on the maximal value of the elastic predictor for the yield function is proposed. As it is highly non linear, a specific solution algorithm is required. The robustness of this constraint is illustrated by three applications: the study of crack propagations by means of a cohesive zone model, the failure of a structure submitted to nonlocal damage and the simulation of a nonlocal strain‐softening plastic specimen. Copyright © 2004 John Wiley & Sons, Ltd.
Multi‐lithology stratigraphic model under maximum erosion rate constraint
Authors: Eymard R. , Gallouët T. , Granjeon D. , Masson R. , Tran Q. H. 
Published: April 2004

AbstractNon‐linear single lithology or multi‐lithology diffusion models have been widely used by sedimentologists and geomorphologists in the field of stratigraphic basin simulations to simulate the large scale depositional transport processes of sediments. Nevertheless, as noticed by many authors, erosion and sedimentation processes are non‐symmetric. Soil material must first be produced in situ by weathering processes prior to be transported by diffusion. This is usually taken into account through a prescribed maximum erosion rate of the sediments, but no mathematical description of the coupling with the diffusion model has been proposed so far. In this paper, we introduce a new mathematical formulation for the coupling of the weather limited erosion and the multi‐lithology diffusion models, which appears as a non‐standard free boundary problem for a new variable acting as a limitor of the fluxes.One of the main advantages of this formulation, compared to existing discrete coupling models, is to enable the definition of efficient discretization schemes. A finite volume scheme with implicit time integration is introduced which is proved to be unconditionally stable in the l∞ norm for the sediment thickness, the sediment concentrations in the lithologies, and the flux limitor variables. A Newton algorithm with an iterative computation of the saturated constraints is used to solve efficiently the non‐linear system resulting from the discretization. The efficiency of the model and the numerical scheme is illustrated on 2D and 3D basin simulation examples. Copyright © 2004 John Wiley & Sons, Ltd.