bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vom Gen zum Produkt: Maßgeschneiderte Oligosaccharide durch Substrat‐, Enzym‐ und genetisches Engineering
Authors: Seibel J. 
Published: November 2009

AbstractNeue Strategien sind erforderlich für die Synthese und den Zugang komplexer Oligosaccharide und Glycokonjugate. Die Kombination von Enzym‐ und Substrat‐Engineering eröffnet eine Vielzahl neuer synthetischer Möglichkeiten bezüglich der Synthese von Oligosacchariden. Durch das Engineering der Enzyme gelingen das Steuern der Stereoselektivität und auch das Erweitern der Substratspezifität. Doch auch durch geeignete Wahl der Substrate können enzymatische Reaktionen in gewünschte Richtungen dirigiert werden. Jedoch liegt die besondere Stärke der Synthese in der Kombination beider Ansätze, die die synthetischen Möglichkeiten eines „althergebrachten Enzymes”︁ um ein Vielfaches erweitern kann.
New Antimicrobial Hexapeptides: Synthesis, Antimicrobial Activities, Cytotoxicity, and Mechanistic Studies
Authors: Sharma Rohit K. , Sundriyal Sandeep , Wangoo Nishima , Tegge Werner , Jain Rahul 
Published: November 2009

AbstractSynthetic antimicrobial peptides have recently emerged as promising candidates against drug‐resistant pathogens. We identified a novel hexapeptide, Orn‐D‐Trp‐D‐Phe‐Ile‐D‐Phe‐His(1‐Bzl)‐NH2, which exhibits broad‐spectrum antifungal and antibacterial activity. A lead optimization was undertaken by conducting a full amino acid scan with various proteinogenic and non‐proteinogenic amino acids depending on the hydrophobic or positive‐charge character of residues at various positions along the sequence. The hexapeptide was also cyclized to study the correlation between the linear and cyclic structures and their respective antimicrobial activities. The synthesized peptides were found to be active against the fungus Candida albicans and Gram‐positive bacteria such as methicillin‐resistant Staphylococcus aureus and methicillin‐resistant Staphylococcus epidermidis, as well as the Gram‐negative bacterium Escherichia coli; MIC values for the most potent structures were in the range of 1–5 μg mL−1 (IC50 values in the range of 0.02–2 μg mL−1). Most of the synthesized peptides showed no cytotoxic effects in an MTT assay up to the highest test concentration of 200 μg mL−1. A tryptophan fluorescence quenching study was performed in the presence of negatively charged and zwitterionic model membranes, mimicking bacterial and mammalian membranes, respectively. The results of the fluorescence study demonstrate that the tested peptides are selective toward bacterial over mammalian cells; this is associated with a preferential interaction between the peptides and the negatively charged phospholipids of bacterial cells.
Hydrogen Radical Additions to Unsaturated Hydrocarbons and the Reverse β‐Scission Reactions: Modeling of Activation Energies and Pre‐Exponential Factors
Authors: Sabbe Maarten K. , Reyniers Marie‐Françoise , Waroquier Michel , Marin Guy B. 
Published: November 2009

AbstractThe group additivity method for Arrhenius parameters is applied to hydrogen addition to alkenes and alkynes and the reverse β‐scission reactions, an important family of reactions in thermal processes based on radical chemistry. A consistent set of group additive values for 33 groups is derived to calculate the activation energy and pre‐exponential factor for a broad range of hydrogen addition reactions. The group additive values are determined from CBS‐QB3 ab‐initio‐calculated rate coefficients. A mean factor of deviation of only two between CBS‐QB3 and experimental rate coefficients for seven reactions in the range 300–1000 K is found. Tunneling coefficients for these reactions were found to be significant below 400 K and a correlation accounting for tunneling is presented. Application of the obtained group additive values to predict the kinetics for a set of 11 additions and β‐scissions yields rate coefficients within a factor of 3.5 of the CBS‐QB3 results except for two β‐scissions with severe steric effects. The mean factor of deviation with respect to experimental rate coefficients of 2.0 shows that the group additive method with tunneling corrections can accurately predict the kinetics and is at least as accurate as the most commonly used density functional methods. The constructed group additive model can hence be applied to predict the kinetics of hydrogen radical additions for a broad range of unsaturated compounds.
Global Minimum‐Energy Structure and Spectroscopic Properties of I2.−⋅n H2O Clusters: A Monte Carlo Simulated Annealing Study
Authors: Pathak Arup Kumar , Mukherjee Tulsi , Maity Dilip Kumar 
Published: November 2009

AbstractThe vibrational (IR and Raman) and photoelectron spectral properties of hydrated iodine‐dimer radical‐anion clusters, I2.−⋅n H2O (n=1–10), are presented. Several initial guess structures are considered for each size of cluster to locate the global minimum‐energy structure by applying a Monte Carlo simulated annealing procedure including spin–orbit interaction. In the Raman spectrum, hydration reduces the intensity of the II stretching band but enhances the intensity of the OH stretching band of water. Raman spectra of more highly hydrated clusters appear to be simpler than the corresponding IR spectra. Vibrational bands due to simultaneous stretching vibrations of OH bonds in a cyclic water network are observed for I2.−⋅n H2O clusters with n≥3. The vertical detachment energy (VDE) profile shows stepwise saturation that indicates closing of the geometrical shell in the hydrated clusters on addition of every four water molecules. The calculated VDE of finite‐size small hydrated clusters is extrapolated to evaluate the bulk VDE value of I2.− in aqueous solution as 7.6 eV at the CCSD(T) level of theory. Structure and spectroscopic properties of these hydrated clusters are compared with those of hydrated clusters of Cl2.− and Br2.−.
Electrochemical Properties of Phospholipid Monolayers at Liquid–Liquid Interfaces
Authors: Santos Hélder A. , García‐Morales Vladimir , Pereira Carlos M. 
Published: November 2009

AbstractBiomembrane models built at the interface between two immiscible electrolytes (ITIES) are useful systems to study phenomena of biological relevance by means of their electrochemical processes. The unique properties of ITIES allow one either to control or measure the potential difference across the biomimetic membranes. Herein we focus on phospholipid monolayers adsorbed at liquid–liquid interfaces, and besides discussing recent developments on the subject, we describe electrochemical techniques that can be used to get insight on the interfacial processes and electrostatic properties of phospholipid membranes at the ITIES. In particular, we examine the electrochemical and physicochemical properties of (modified) phospholipid monolayers and their interaction with other biologically relevant compounds. The use of liquid–liquid electrochemistry as a powerful tool to characterize drug properties is outlined. Although this review is not a survey of all the work in the field, it provides a comprehensive referencing to current research.
Using End Groups to Tune the Linear and Nonlinear Optical Properties of Bis(dioxaborine)‐Terminated Polymethine Dyes
Authors: Matichak Jonathan D. , Hales Joel M. , Ohira Shino , Barlow Stephen , Jang Sei‐Hum , Jen Alex K.‐Y. , Brédas Jean‐Luc , Perry Joseph W. , Marder Seth R. 
Published: November 2009

AbstractSix anionic pentamethine dyes with different 2,2‐difluoro‐4‐aryl‐1,3,2(2 H)‐dioxaborin‐6‐yl termini were synthesized and isolated as tetra‐n‐octylammonium salts with a variety of aryl groups appended to increase conjugation beyond the dioxaborine termini. The increased conjugation was expected to decrease the energy of the lowest‐lying excited state, and increase the transition dipole moment linking this state to the ground state, which would be anticipated to result in an increase in the real part of the third‐order polarizability, Re(γ). UV/Vis‐NIR absorption spectroscopy indicates that the absorption maxima in DMSO vary from 691 to 761 nm, with the longest wavelength transitions observed for a derivative where the aryl group is 4‐nitrophenyl. Closed‐aperture Z‐scan measurements at 1.3 μm in DMSO indicate that Re(γ) varies from −2.9×10−33 to −5.4×10−33 esu in these systems. The largest magnitude of Re(γ) was observed for a dye with E‐4‐styrylphenyl aryl groups. This result can be rationalized using a two‐state expression which relates Re(γ) to the energy and transition dipole moment of the transition from the ground state to the lowest‐lying excited state. A nonamethine analogue of this compound was also synthesized and exhibits a slightly larger Re(γ) with respect to a previously reported bis(dioxaborine)‐terminated nonamethine. The extension of conjugation beyond the dioxaborine termini seems to result in an overall increase in Re(γ). However, the effects are smaller than those found by increasing conjugation in the polymethine bridge due to reduced participation of terminal groups in the HOMO.
Churg‐Strauss and Goodpasture's syndromes: A rare association
Authors: Carrilho Patricia , Cruz Pedro , Natario Ana , Rocha Carla , Assuncao Jose , Barreto Carlos , Vaz Alvaro , Martins Ana Paula , Vinhas Jose 
Published: November 2009

AbstractChurg‐Strauss is a rare syndrome with only a few hundred cases reported in the literature. Overlap with other vasculitic disorders is even more unusual, although some cases have been described. Patients may have several phases of the syndrome over many years, before the development of systemic vasculitis. We report the case of a patient whose clinical and pathological evolution suggests an initial presentation consistent with Churg‐Strauss and a subsequent evolution to Goodpasture disease, a sequential development that had not yet been reported. Recent efforts to classify vasculitis according to clinical and pathological features have been most helpful in guiding diagnosis and therapeutic options, although some clinical cases still represent a challenge.
Vitamin D deficiency in dialysis patients and its effect on various disease markers
Authors: Korkor Adel B. , Bretzmann Christine M. , Eastwood Daniel C. 
Published: November 2009

AbstractBACKGROUNDEpidemiologic data has linked vitamin D deficiency with a variety of negative health outcomes. The purpose of this study was to determine the prevalence of 25‐hydroxy‐vitamin D deficiency in our outpatient dialysis patients and to assess the association between vitamin D level and various markers of disease.METHODSWe performed a cross‐sectional study evaluating 25‐hydroxy‐vitamin D levels in 327 chronic dialysis patients. Associations between vitamin D level and various disease markers were measured using Pearson correlation, Spearman correlation, and Kendall's Tau.RESULTSMean 25‐hydroxy‐vitamin D level was 19.7 ± 12.7 ng/mL. Vitamin D deficiency, defined as 25‐hydroxy‐vitamin D <30 ng/mL, was present in 85% of individuals (277/327). Using a Spearman correlation, there was a statistically significant negative association between vitamin D level and triglycerides and transferrin saturation while a positive association existed with albumin. No other significant correlations were noted.CONCLUSIONSAlthough vitamin D deficiency was highly prevalent in our dialysis patients, we were unable to demonstrate a correlation between a 25‐hydroxy‐vitamin D level and the majority of disease markers evaluated in this study. Further research is necessary to fully elucidate the consequence of vitamin D deficiency in patients with end‐stage renal disease.
Long‐term mycophenolate mofetil treatment in pediatric renal transplant patients
Authors: Roberts John P. , Potter Donald , Bouw M. René 
Published: November 2009

AbstractOBJECTIVEClinical trials have demonstrated the safety and efficacy of mycophenolate mofetil (MMF) in reducing adult renal allograft rejection. We assessed the long‐term safety and efficacy of MMF in pediatric renal allograft recipients.METHODSIn this 3‐year, open‐label, dose‐ranging study, 40 patients received twice‐daily (bid) MMF 15, 23, or 30 mg/kg (to a maximum of 1,500 mg bid), cyclosporine, and corticosteroids. As 23 mg/kg MMF bid was shown to provide similar pharmacokinetics to the adult dosage of 1 g bid, this study was terminated after most patients had received treatment for 1 to 2 years. Thereafter, 33 patients were eligible to continue receiving MMF 23 mg/kg bid in a follow‐up study.RESULTSA total of 26 patients completed both studies (total follow‐up of up to 3 years post‐transplant). There were no deaths in either study; 2 graft losses occurred during the dose‐ranging study. The total 3‐year acute rejection rate for both studies was 42% (17/40 patients). All patients experienced 1 or more adverse events, but only 4 patients (10%) withdrew because of adverse events.DISCUSSIONLong‐term treatment with MMF was effective in preventing rejection and provided excellent patient and graft survival. Mycophenolate mofetil was well tolerated and had a safety profile consistent with that in adult renal allograft recipients.
Nursing personnel faced with living kidney donation in a Spanish hospital with a living‐donor kidney transplant program
Authors: Ríos Antonio , Martínez‐Alarcón Laura , Rodríguez María del Mar , Lucas Dolores , Parrilla P. , Ramíre Pablo 
Published: November 2009

AbstractOBJECTIVETo analyze attitudes toward living‐kidney donation among nursing personnel in a Spanish hospital with a living kidney transplant program and to analyze the influence of different types of variables on such attitudes.METHODSThis was a descriptive transversal study. The study was carried out in a Spanish third‐level hospital with an organ transplant program (kidney, liver, pancreas, and heart) and a living‐donation program (kidney and liver). A random sample (n = 305) was taken and was stratified by type of service among nursing personnel. Attitude was evaluated using a validated survey. It was completed anonymously and was self‐administered.RESULTSThe questionnaire completion rate was 95% (n = 289). Of these respondents, 86% (n = 248) were in favor of living‐related kidney donation. The following were found to be factors that were significantly related to attitude toward living kidney donation: (1) attitude toward deceased donor donation (p = .002); (2) a respondent's belief in the possibility of needing a transplant in the future (p = .002); and (3) a respondent's willingness to accept a living donated kidney (p < .0005).DISCUSSIONOur hospital nursing personnel have a favorable attitude toward living‐related kidney donation, and this attitude is mainly determined by reciprocity.
Polyneuropathy in type 1 and type 2 diabetes: comparison of nerve conduction studies, thermal perception thresholds and intraepidermal nerve fibre densities
Authors: Løseth Sissel , Mellgren Svein I. , Jorde Rolf , Lindal Sigurd , Stålberg Erik 
Published: November 2009

AbstractBackgroundTo evaluate possible differences in distal polyneuropathy (PN) characteristics and degree of abnormalities for various small and large fibre parameters in diabetes type 1 (DM1) and type 2 (DM2).MethodsSixty‐six DM1 and 57 DM2 patients with or without PN symptoms were included. Nerve conduction studies (NCS), quantitative sensory testing (QST) and quantification of intraepidermal nerve fibres (IENFs) were performed. Z‐scores were calculated from reference materials.ResultsIn both groups, 42% had abnormal NCS classification, 42% (DM1) and 39% (DM2) abnormal QST, as well as 40% (DM1) and 32% (DM2) abnormal IENF density. Seventy percent (DM1) and 65% (DM2) had one of the three tests abnormal (differences not significant). Correlations were found between most Z‐score parameters and disease duration and HbA1c in DM1, but fewer in DM2. In multivariate analysis, some NCS and QST Z‐scores were more abnormal in DM2. Symptom scoring correlated better with NCS and QST parameters in DM1.ConclusionsThe differences could be referred to disease duration, glycaemic control and possibly patient age. The various parameters from NCS, QST and IENF analysis contribute differently in the assessment of polyneuropathy. Copyright © 2009 John Wiley & Sons, Ltd.
Diabetes and microvascular pathophysiology: role of epidermal growth factor receptor tyrosine kinase
Authors: Matrougui Khalid 
Published: November 2009

AbstractType 2 diabetes is responsible for the increased prevalence of ischaemic heart disease, generally related to coronary artery disease, which is associated with increased morbidity and death in diabetic patients. Epidermal growth factor receptor (EGFR) tyrosine kinase, one of the many factors involved in cell growth and migration, has been shown to be key element in the development of microvessel myogenic tone. In a recent study, we have shown that microvascular dysfunction in type 2 diabetes is dependent on the exacerbation of the EGFR tyrosine kinase phosphorylation. Thus, further elucidation of this EGFR transactivation and down stream signalling will offer a new direction to investigate the mechanism of microvascular dysfunction responsible for heart disease that occurs in type 2 diabetes. In this review, we discuss the link between the EGFR transactivation and microvascular dysfunction that occurs in type 2 diabetes. Copyright © 2009 John Wiley & Sons, Ltd.
Ex vivo TCR‐induced leukocyte gene expression of inflammatory mediators is increased in type 1 diabetic patients but not in overweight children
Authors: Rosa Jaime S. , Mitsuhashi Masato , Oliver Stacy R. , Ogura Mieko , Flores Rebecca L. , Pontello Andria M. , Galassetti Pietro R. 
Published: November 2009

AbstractBackgroundAbnormal systemic concentrations of proinflammatory cytokines/chemokines have been implicated in the development of long‐term cardiovascular complications in type 1 diabetes (T1DM) and obesity. Whether leukocyte white blood cell (WBC) gene expression of these proinflammatory mediators contributes to their increased systemic levels, however, remains unclear, especially in the pediatric patient populations. This study examines mRNA changes of 9 cytokines and chemokines in WBCs following ex vivo immunostimulation from 9 T1DM (13.4 ± 0.5 year, 4F/5 M), 23 overweight (OW, 12.3 ± 0.5 year, 10F/13M, BMI% 97.1 ± 0.5 and > 90.0), and 21 healthy (CL, 13.8 ± 0.7 year, 9F/12 M, BMI% 59.6 ± 4.6 and < 85.0) children.MethodsAll subjects had been maintained in euglycemic conditions for at least 90 min before blood draws. Whole blood was then sampled and incubated with anti‐T‐cell receptor (TCR) antibody or heat‐aggregated IgG (HAG) to stimulate T‐cell and Fc receptors (FcR), respectively. After lysis of leukocytes, mRNA levels of six tumor necrosis factor superfamily cytokines (TNFSF2, 5, 6, 7, 9, 14) and three chemokines (CCL8, 20, and CXCL10) were measured using RT‐PCR.ResultsFollowing TCR stimulation, T1DM displayed significantly greater mRNA responses than CL for TNFSF5, 7, 9, and CCL8, and CXCL10; TNFSF9, CCL8, and CXCL10 were also significantly higher in T1DM than OW; no difference was observed between OW and CL. FcR stimulation induced similar responses across groups.ConclusionsLeukocytes of T1DM children displayed exaggerated gene expression in response to ex vivo TCR induction of five key proinflammatory cytokines/chemokines. This elevated leukocyte gene expression may be one of the pathophysiological contributors to the development of vascular complications in T1DM. Copyright © 2009 John Wiley & Sons, Ltd.
Fibrinogen kinetics and protein turnover in obese non‐diabetic males: effects of insulin
Authors: Tessari P. , Cosma A. , Vettore M. , Millioni R. , Puricelli L. , Cogo P. , Cecchet D. , Carnielli V. , Kiwanuka E. 
Published: November 2009

AbstractBackgroundAlthough hyperfibrinogenemia and insulin resistance are common in obesity and diabetes mellitus, the impact of obesity per se on fibrinogen turnover and the insulin effects on fibrinogen and protein kinetics is unknown.MethodsWe measured fibrinogen and albumin fractional (FSR) and absolute (ASR) synthesis rates, as well as protein turnover, in non‐diabetic, obese and in control male subjects both before and following an euglycemic, euaminoacidemic, hyperinsulinemic clamp, using L‐[2H3]‐Leucine isotope infusion.ResultsIn the obese, basal fibrinogen concentrations was ≈ 25% greater (p < 0.035), and fibrinogen pool ≈ 45% greater (p < 0.005), than in controls. Both FSR and ASR of fibrinogen were similar to control values. With hyperinsulinemia, although fibrinogen FSR and ASR were not significantly modified with respect to baseline in either group, fibrinogen ASR resulted to be ≈ 50% greater in the obese than in controls (p < 0.015). Hyperinsulinemia equally stimulated albumin synthesis and suppressed leucine appearance from endogenous proteolysis in both groups. Amino acid clearance was also similar. In the obese, the insulin‐mediated glucose disposal was ≈ 50% lower (p < 0.03) than in controls, and it was inversely correlated with fibrinogen ASR during the clamp in both groups (r = − 0.58).ConclusionsIn obese, non‐diabetic males, post absorptive fibrinogen production is normal. Whole‐body amino acid disposal, basal and insulin‐responsive protein degradation, and albumin synthesis are also normal. However, the greater fibrinogen ASR in the obese with hyperinsulinemia, and the inverse relationship between insulin sensitivity and clamp fibrinogen production, suggest a role for hyperinsulinemia and/or insulin resistance on fibrinogen production in obesity. Copyright © 2009 John Wiley & Sons, Ltd.
Data management to enhance long‐term watershed research capacity: context and STEWARDS case study
Authors: Steiner Jean L. , Sadler E. John , Hatfield Jerry L. , Wilson Greg , James David , Vandenberg Bruce , Ross John D. , Oster Teri , Cole Kevin 
Published: November 2009

AbstractWater resources are under pressure globally due to growing population, human migration into arid regions, and diverse competing needs. In recent decades, progress in the study of information (informatics) and its manipulation via computer‐based tools has stimulated development of data systems in many natural resources disciplines. Such informatics systems provide data storage, access, visualization, perhaps with analysis/modelling tools, and download capacity. Application of database technology can overcome problems of fragmentation, inadequate documentation, and cumbersome manipulation of complex data. Data management was a critical requirement for USDA's Conservation Effects Assessment Project (CEAP) which was established to quantify environmental effects of agricultural conservation practices. Although USDA and the Agricultural Research Service (ARS) have conducted watershed research since early 20th century, the data have been managed and disseminated independently from each research location, reducing accessibility and utility of these data for policy‐relevant, multi‐site analyses. To address these concerns, STEWARDS (Sustaining the Earth's Watersheds—Agricultural Research Data System) was developed to compile, document, and provide access to data from loosely coupled research watersheds. The STEWARDS case study is used to illustrate the role of data management in enhancing ecohydrological research and evolving information technologies available to improve data management from complex ecohydrologic studies. Published in 2009 by John Wiley & Sons, Ltd.