bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanistic Study on Rearrangement Cascades Starting from Annulated 2‐Aza‐hepta‐2,4‐dienyl‐6‐ynyl Anions: Formation of Aniline and Azepine Derivatives
Authors: Lyaskovskyy Volodymyr , Fröhlich Roland , Würthwein Ernst‐Ulrich 
Published: January 2007

AbstractDeprotonation of benzothiophene‐derived alkynyl imine 11 with lithium diisopropylamide (LDA) and subsequent transmetalation with ZnCl2 etherate furnished azepine 12 upon aqueous workup. Similarly, alkynyl benzaldimine 1 a gave a mixture of benzazepine 13 and naphthylamine 14. Allylic benzonitriles 15 a,b reacted to produce naphthylamine 16 upon deprotonation with LDA at room temperature. In an analogous manner, imino benzonitrile 17 may be converted into 4‐amino isoquinoline 18 by means of an intramolecular nucleophilic attack on the nitrile function upon treatment with LDA. The allylic benzonitriles 19 a,b were prepared by LDA treatment of alkynyl imine 11. They were further converted to amino dibenzothiophene 20 by LDA deprotonation and aqueous workup. These various transformations represent the key steps of a multistep reaction cascade, which was previously postulated on the basis of quantum chemical calculations. Thus, all features of this complex rearrangement mechanism could now be confirmed experimentally. DFT calculations support the lower reactivity of zinc species in the ring‐opening step compared to the lithium intermediates. All new compounds were completely characterized by spectroscopic data, including X‐ray diffraction studies for the key compounds 12, 19 a, and 20.
Breaches of the pial basement membrane and disappearance of the glia limitans during development underlie the cortical lamination defect in the mouse model of muscle‐eye‐brain disease
Authors: Hu Huaiyu , Yang Yuan , Eade Amber , Xiong Yufang , Qi Yue 
Published: January 2007

AbstractNeuronal overmigration is the underlying cellular mechanism of cerebral cortical malformations in syndromes of congenital muscular dystrophies caused by defects in O‐mannosyl glycosylation. Overmigration involves multiple developmental abnormalities in the brain surface basement membrane, Cajal‐Retzius cells, and radial glia. We tested the hypothesis that breaches in basement membrane and the underlying glia limitans are the key initial events of the cellular pathomechanisms by carrying out a detailed developmental study with a mouse model of muscle‐eye‐brain disease, mice deficient in O‐mannose β1,2‐N‐acetylglucosaminyltransferase 1 (POMGnT1). The pial basement membrane was normal in the knockout mouse at E11.5. It was breached during rapid cerebral cortical expansion at E13.5. Radial glial endfeet, which comprise glia limitans, grew out of the neural boundary. Neurons moved out of the neural boundary through these breaches. The overgrown radial glia and emigrated neurons disrupted the overlying pia mater. The overmigrated neurons did not participate in cortical plate (CP) development; rather they formed a diffuse cell zone (DCZ) outside the original cortical boundary. Together, the DCZ and the CP formed the knockout cerebral cortex, with disappearance of the basement membrane and the glia limitans. These results suggest that disappearance of the basement membrane and the glia limitans at the cerebral cortical surface during development underlies cortical lamination defects in congenital muscular dystrophies and a cellular mechanism of cortical malformation distinct from that of the reeler mouse, double cortex syndrome, and periventricular heterotopia. J. Comp. Neurol. 501:168–183, 2007. © 2007 Wiley‐Liss, Inc.
A multigrid method for solving the Navier–Stokes/Boussinesq equations
Authors: Cheikh Nader Ben , Beya Brahim Ben , Lili Taieb 
Published: January 2007

AbstractThe present work investigates the efficiency and the accuracy of a multigrid (MG) technique for solving the Navier–Stokes/Boussinesq equations. In order to improve convergence, an accelerated full multigrid (AFMG) method with the iterative red and black successive over‐relaxation smoother (RBSOR) is utilized. The AFMG method consists in introducing an accelerated parameter Γ>0 in the standard full multigrid procedure (FMG). A well‐known benchmark problem is used to demonstrate the effectiveness and the accuracy of the method. Solutions are compared with those of the literature and show excellent agreement. Results for Prandtl numbers Pr=12.5, 6.8, 0.71 and 0.025 are also presented in this paper. It is observed that the mean heat transfer rate is minimum for Pr=0.71 and maximum for Pr=0.025. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis, Crystal Structures, and Oxidation States of MM′X‐Type Platinum–Rhodium Dinuclear Complexes Having Amidate Bridging Ligands
Authors: Uemura Kazuhiro , Yamasaki Kana , Fukui Kôichi , Matsumoto Kazuko 
Published: January 2007

AbstractSix novel Pt–Rh dinuclear complexes (1–6), [PtRh(PVM)2(NH3)2Cl3]·4H2O (1, PVM = tBuCONH–), [PtRh(PVM)2(en)Cl3]·3H2O (2, en = ethylenediamine), [PtRh(PVM)2(NH2CH3)2Cl3]·3H2O (3), [PtRh(PVM)2(NH2tBu)2Cl3]·3H2O (4), [PtRh(TCM)2(NH3)2Cl3] (5, TCM = Cl3CCONH–), and [PtRh(BZM)2(NH3)2Cl3]·H2O (6, BZM = PhCONH–), have been synthesized from Pt mononuclear complexes having nitrogen‐coordinated amidate ligands with noncoordinated amidate oxygen atoms. X‐ray analysis revealed that compounds 1 and 2 form zigzag one‐dimensional chains in the form [–Pt–Rh–Cl–]n. The oxidation states of the metal ions have been determined by X‐ray photoelectron spectroscopy (XPS) and 195Pt NMR spectroscopic analysis, and are Pt(+2, d8)···Rh(+3, d6). In comparison with the Pt–Rh distances found in the literature, it has become apparent that the Pt–Rh dinuclear complexes have a dative Pt(d8)→Rh(d6) bond, where the Pt d orbital is stabilized by the overlap with the d orbital of the Rh atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The Outer Membrane of the Marine Gram‐Negative Bacterium Alteromonas addita is Composed of a Very Short‐Chain Lipopolysaccharide with a High Negative Charge Density
Authors: Leone Serena , Molinaro Antonio , Sturiale Luisa , Garozzo Domenico , Nazarenko Evgeny L. , Gorshkova Raisa P. , Ivanova Elena P. , Shevchenko Liudmila S. , Lanzetta Rosa , Parrilli Michelangelo 
Published: January 2007

AbstractThe complete structure of the lipopolysaccharide isolated from the Gram‐negative marine bacterium Alteromonas addita, type strain KMM 3600T = R10SW13T, has been elucidated by means of a combined chemical approach and state‐of‐the‐art NMR and MS analyses. Isolation and characterisation of the lipid A moiety and the core oligosaccharide were pursued separately after either acid or alkaline treatment of the lipopolysaccharide. The structure detected was identified as a novel, highly negatively charged, deep‐rough lipopolysaccharide in which a trisaccharide subunit is connected to a typical lipid A glucosamine backbone. Within the core oligosaccharide, a phosphodiester bridge connects a glucose unit to a heptose residue.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Large cystic infiltrating ductal carcinoma in male breast
Authors: Degirmenci Bumin , Gulhan Sitki , Acar Murat , Haktanir Alpay 
Published: January 2007

AbstractCystic infiltrating ductal carcinoma is a very rare entity that, to the best of our knowledge, has not yet been reported in males. We report the sonographic and CT findings of a large cystic infiltrating ductal carcinoma in a 51‐year‐old man. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 35, 2007
Towards a consensus on datasets and evaluation metrics for developing B‐cell epitope prediction tools
Authors: Greenbaum Jason A. , Andersen Pernille Haste , Blythe Martin , Bui Huynh‐Hoa , Cachau Raul E. , Crowe James , Davies Matthew , Kolaskar A. S. , Lund Ole , Morrison Sherrie , Mumey Brendan , Ofran Yanay , Pellequer Jean‐Luc , Pinilla Clemencia , Ponomarenko Julia V. , Raghava G. P. S. , van Regenmortel Marc H. V. , Roggen Erwin L. , Sette Alessandro , Schlessinger Avner , Sollner Johannes , Zand Martin , Peters Bjoern 
Published: January 2007

AbstractA B‐cell epitope is the three‐dimensional structure within an antigen that can be bound to the variable region of an antibody. The prediction of B‐cell epitopes is highly desirable for various immunological applications, but has presented a set of unique challenges to the bioinformatics and immunology communities. Improving the accuracy of B‐cell epitope prediction methods depends on a community consensus on the data and metrics utilized to develop and evaluate such tools. A workshop, sponsored by the National Institute of Allergy and Infectious Disease (NIAID), was recently held in Washington, DC to discuss the current state of the B‐cell epitope prediction field. Many of the currently available tools were surveyed and a set of recommendations was devised to facilitate improvements in the currently existing tools and to expedite future tool development. An underlying theme of the recommendations put forth by the panel is increased collaboration among research groups. By developing common datasets, standardized data formats, and the means with which to consolidate information, we hope to greatly enhance the development of B‐cell epitope prediction tools. Copyright © 2007 John Wiley & Sons, Ltd.
LC/MS characterization of undesired products formed during iodoacetamide derivatization of sulfhydryl groups of peptides
Authors: Yang Zhihua , Attygalle Athula B. 
Published: January 2007

AbstractMany undesired by‐products have been noticed during alkylation with iodoacetamide, a widely used derivatization reaction in proteomics for the determination of sulfhydryl groups in peptides and proteins. We report here that iodoacetamide reacts with the N‐terminal NH2 and the C‐terminal carboxylic acid groups, in addition to the peripheral residues bearing protic functional groups. If sufficient reaction time is given, the N‐terminal NH2 group is readily dialkylated by iodoacetamide. In fact, the N‐terminal NH2 group reacts even faster than the reactive sites present in residues, such as tyrosine or histidine. LC/MS investigations with certain reactive peptides show that by‐products are formed in a relatively short reaction time, even at room temperature. Interestingly, derivatives formed in this way are useful for sequence determination of peptides by MS since the intensities of y″ ions are highly suppressed in the spectra of N‐terminus mono‐ and dialkylated peptides, whereas those of b‐ions are significantly enhanced. For example, in the spectrum of N,N‐dicarboxamidomethyl derivative of Val‐Ala‐Ala‐Phe (VAAF), the y‐series ions are virtually absent. On the other hand, when the derivatization takes place at the carboxylic group, the y‐series ions are markedly observed in the spectra of these undesired O‐carboxamidomethyl derivatives. Copyright © 2007 John Wiley & Sons, Ltd.
Anti‐catabolic effect of OP‐1 in chronically compressed intervertebral discs
Authors: Chubinskaya Susan , Kawakami Mamoru , Rappoport Lev , Matsumoto Takuji , Migita Nami , Rueger David C. 
Published: January 2007

AbstractExperimental animal models of disc degeneration have been used to assess the biomechanical behavior, biochemical composition, and biological changes in the intervertebral discs. The objective of our study was to evaluate the anabolic and anti‐catabolic effects of intradiscal injection of Osteogenic Protein‐1 (OP‐1) by histology and immunohistochemistry in disc degeneration model. Thirty‐four rats were divided into five groups: intact control; sham control; compressed nucleus pulposus (NP) injected with saline; and two OP‐1 groups: COP‐1 group (compression was continued after intradiscal OP‐1 injection) and ROP‐1 group (compression was released at the time of OP‐1 injection). Anabolic and anti‐catabolic effects of OP‐1 were evaluated by histology and immunohistochemistry with the following antibodies: anti‐pro‐ and anti‐mature OP‐1, anti‐MMP‐13, anti‐aggrecanase, anti‐substance P, anti‐tumor necrosis factor‐α (TNF‐α), and anti‐interleukin‐1β (IL‐1β). The OP‐1 injection to the degenerative disc stimulated an anabolic response characterized by the restoration of the normal morphology of the disc, increased Safranin O staining in the NP, extention of the extracellular matrix, and stimulation of endogenous OP‐1 synthesis in the NP, annulus fibrosis (AF), and end‐plate. The anti‐catabolic effect of OP‐1 was documented by reduced immunostaining for aggrecanase, MMP‐13, substance P, TNF‐α, and IL‐1β. This study confirmed the anti‐catabolic activity of OP‐1 as demonstrated previously in human articular cartilage and provided critical evidence for the potential of OP‐1 therapy in the treatment of disc degeneration. Because substance P is a neuropeptide linked with inflammation and pain, a reduction in the level of this protein may support our previously reported results on the effect of OP‐1 on pain‐related behavior. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:517–530, 2007
(S)‐(–)‐α,α‐Di(2‐naphthyl)‐2‐pyrrolidinemethanol, a useful tool to study the recognition mechanism in chiral ligand‐exchange chromatography
Authors: Natalini Benedetto , Sardella Roccaldo , Macchiarulo Antonio , Natalini Serena , Pellicciari Roberto 
Published: January 2007

AbstractA dynamic coating of the RP‐18 carbon chain layers with the new chiral selector (S)‐(–)‐α,α‐di(2‐naphthyl)‐2‐pyrrolidinemethanol allowed the formation of a mixed chiral stationary phase that has been used in the separation of a selected set of amino acid racemates. Both a representative model and classification structure‐property relationship studies have been performed in order to study the contribution of hydrophobic, bulky and electron‐donating groups in the side chain of the chiral selector to the mechanism of chiral recognition.
Reaction kinetics and pathway of hydrothermal decomposition of aspartic acid
Authors: Faisal Muhammad , Sato Nobuaki , Quitain Armando T. , Daimon Hiroyuki , Fujie Koichi 
Published: January 2007

AbstractThe kinetics and pathway of hydrothermal decomposition of aspartic acid were studied using a continuous‐flow tubular reactor. The reaction was carried out in the temperature range of 200–260°C and at a pressure of 20 MPa. Deamination was the primary reaction, indicated by the presence of significant amount of ammonia, fumaric acid, or maleic acid in the products. Other reaction products were pyruvic acid, malic acid, and traces of succinic and lactic acid. Traces of alanine were also detected, showing the possibility of decomposing high‐molecular weight amino acids to obtain simple amino acids such as glycine or alanine. Results on the effect of reaction parameters demonstrated that decomposition of aspartic acid is highly temperature dependent under hydrothermal conditions. For a slight temperature difference of 60°C (from 200 to 260°C), the first‐order reaction rate constants of 0.003 significantly increased to 0.231 s−1. The activation energy was 144 kJ/mol, as calculated by the Arrhenius equation. No significant effect was exhibited by other reaction parameters such as pH and pressure. The results are useful in controlling the hydrolysis of proteinaceous materials toward high yield of aspartic acid under hydrothermal conditions. © 2007 Wiley Periodicals, Inc. 39: 175–180, 2007
Long-Term Survival and Predictors of Relapse After Orthotopic Liver Transplantation for Alcoholic Liver Disease
Authors: Pfitzmann Robert , Schwenzer Jeannette , Rayes Nada , Seehofer Daniel , Neuhaus Ruth , Nüssler Natascha C. 
Published: January 2007

Abstract

The relevance of sobriety for outcome after orthotopic liver transplantation (OLT) for alcoholic liver disease (ALD) is still discussed controversially. We conducted a retrospective analysis of 300 patients transplanted for ALD with regard to recurrent alcohol consumption, risk factors for drinking after OLT, and long-term survival. The 300 patients underwent OLT for ALD between 1989 and 2002. Median follow-up was 89 months. Incidence and severity of drinking, survival rates, and causes of death were assessed. Age, gender, duration of pretransplant sobriety, social support, presence of children, and the results of psychosomatic evaluation were analyzed for their impact on recurrent alcohol consumption after OLT. Drinking of various degrees was observed in 19% of ALD patients after OLT. Pretransplant sobriety of less than 6 months, absence of companion in life, presence of young children, and a predicted poor psychosomatic prognosis were associated with an increased risk of recurrent alcohol consumption, whereas age and gender were not independent risk factors. Survival rates of patients who resumed abusive drinking were significantly lower than survival rates of abstinent patients or patients with minor lapses. Recurrent alcoholic liver disease accounted for the vast majority of deaths among patients who resumed abusive drinking after OLT, whereas malignant tumors, infections, and cardiovascular disease were the most common causes of death among abstinent patients. In conclusion, abusive drinking after OLT is associated with poor long-term survival. Analysis of risk factors may help to identify patients with a high risk for recurrent alcohol abuse after OLT. Liver Transpl, 2006. © 2006 AASLD.
Myasthenia gravis and Lambert–Eaton myasthenic syndrome in the same patient
Authors: Sha Sharon J. , Layzer Robert B. 
Published: January 2007

AbstractAn 18‐year‐old‐woman developed symptoms of generalized myasthenia gravis (MG). Antibodies to the acetylcholine receptor were found in her serum, but electrodiagnostic testing showed abnormalities typical of the Lambert–Eaton myasthenic syndrome (LEMS). Following thymectomy, the thymus gland showed thymic hyperplasia typical of MG, and the patient responded to treatment with 3,4‐diaminopyridine and pyridostigmine. There have been few reports in the literature of MG and LEMS coexisting in the same patient. In this case, electrodiagnostic tests, antibody studies, thymus pathology, and response to treatment suggest that both disorders contributed to the patient's symptoms. Thymic hyperplasia, so far only known to be associated with MG, provides strong evidence that both diseases were symptomatic. Muscle Nerve, 2007
Synthesis and optoelectronic properties of silole‐containing polyfluorenes with binary structures
Authors: Liu Zhitian , Wang Lei , Chen Junwu , Wang Feng , Ouyang Xiaoying , Cao Yong 
Published: January 2007

Abstract2,5‐Bis(2‐bromofluorene‐7‐yl)silole was prepared by a modified one‐pot synthesis with a reverse addition procedure, from which novel silole‐containing polyfluorenes with binary random and alternating structures (silole contents between 4.5 and 25% and high Mw up to 509 kDa were successfully synthesized. The well‐defined repeating unit of the alternating copolymer comprises a terfluorene and a silole ring. Optoelectronic properties including UV absorption, electrochemistry, photoluminescence (PL), and electroluminescence (EL) of the copolymers were examined. The different excitation energy transfers from fluorene to silole of the copolymers in solution and in the solid state were compared. The films of the copolymers showed silole‐dominant green emissions with high absolute PL quantum yields up to 83%. EL devices of the copolymers with a configuration of ITO/PEDOT/copolymer/Ba/Al displayed exclusive silole emissions peaked at around 543 nm and the highest EL efficiency was achieved with the alternating copolymer. Using the alternating copolymer and poly(9,9‐dioctylfluorene) as the blend‐type emissive layer, a maximum external quantum efficiency of 1.99% (four times to that of the neat film) was realized, which was a high efficiency so far reported for silole‐containing polymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 756–767, 2007
On modelling response propensity for dwelling unit (DU) level non‐response adjustment in the Medical Expenditure Panel Survey (MEPS)
Authors: Wun Lap‐Ming , Ezzati‐Rice Trena M. , Diaz‐Tena Nuria , Greenblatt Janet 
Published: January 2007

AbstractNon‐response is a common problem in household sample surveys. The Medical Expenditure Panel Survey (MEPS), sponsored by the Agency for Healthcare Research and Quality (AHRQ), is a complex national probability sample survey. The survey is designed to produce annual national and regional estimates of health‐care use, expenditures, sources of payment, and insurance coverage for the U.S. civilian non‐institutionalized population. The MEPS sample is a sub‐sample of respondents to the prior year's National Health Interview Survey (NHIS) conducted by the National Center for Health Statistics (NCHS). The MEPS, like most sample surveys, experiences unit, or total, non‐response despite intensive efforts to maximize response rates. This paper summarizes research on comparing alternative approaches for modelling response propensity to compensate for dwelling unit (DU), i.e. household level non‐response in the MEPS.Non‐response in sample surveys is usually compensated for by some form of weighting adjustment to reduce the bias in survey estimates. To compensate for potential bias in survey estimates in the MEPS, two separate non‐response adjustments are carried out. The first is an adjustment for DU level non‐response at the round one interview to account for non‐response among those households subsampled from NHIS for the MEPS. The second non‐response adjustment is a person level adjustment to compensate for attrition across the five rounds of data collection. This paper deals only with the DU level non‐response adjustment. Currently, the categorical search tree algorithm method, the chi‐squared automatic interaction detector (CHAID), is used to model the response probability at the DU level and to create the non‐response adjustment cells. In this study, we investigate an alternative approach, i.e. logistic regression to model the response probability. Main effects models and models with interaction terms are both evaluated. We further examine inclusion of the base weights as a covariate in the logistic models. We compare variability of weights of the two alternative response propensity approaches as well as direct use of propensity scores.The logistic regression approaches produce results similar to CHAID; however, using propensity scores from logistic models with interaction terms to form five classification groups for weight adjustment appears to perform best in terms of limiting variability and bias. Published in 2007 by John Wiley & Sons, Ltd.
Epizootiology of virus diseases in three lepidopterous insect species of alfalfa
Authors: Tanada Y. , Omi Esther M. 
Published: January 2007

SummaryThe incidence of virus infections in three lepidopterous insect species was studied from 1965 to 1968 in alfalfa fields in California. The insects were the alfalfa caterpillar, Colias eurytheme; the beet armyworm, Spodoptera exigua; and the alfalfa looper, Autographa californica. In C. eurytheme, the major virus was a nuclear polyhedrosis virus (NPV); in S. exigua, a granulosis virus (GV) and an NPV; in A. californica, a GV. Virus epizootics did not develop in very high densities of C. eurytheme. Virus epizootics occurred in low host densities of the three insect species, especially in populations of A. californica. The virus acted as a density‐dependent factor in the regulation of the populations of S. exigua and A. californica. Temperature, humidity and rainfall had no marked effect on the incidence of virus infections.