bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformational preferences and prolyl cis–trans isomerization of phosphorylated Ser/Thr‐Pro motifs
Authors: Byun Byung Jin , Kang Young Kee 
Published: November 2009

AbstractThe conformational study on Ac‐pSer‐Pro‐NHMe and Ac‐pThr‐Pro‐NHMe peptides has been carried out using hybrid density functional methods with the implicit solvation reaction field theory at the B3LYP/ 6‐311++G(d,p)//B3LYP/6‐31+G(d) level of theory in the gas phase and in solution (chloroform and water). For both pSer‐Pro and pThr‐Pro peptides in the gas phase and in chloroform, the most preferred conformation has the α‐helical structure for the pSer/pThr residue, the down‐puckered polyproline I structure for the Pro residue, and the cis prolyl peptide bond between the two residues, in which two hydrogen bonds between the phosphate oxygens with the backbone NH groups seem to play a role. However, the trans conformations that have a single hydrogen bond of the phosphate oxygen with either of two backbone NH groups become most preferred for both peptides in water. This is because the hydration free energy of the anionic oxygen of the phosphate group is expected to dramatically decrease for the cis conformation upon formation of the hydrogen bond with the backbone NH groups. These calculated results are consistent with the observations by NMR and IR experiments, suggesting the existence of hydrogen bonds between the charged phosphoryl group and the backbone amide protons in solution. The calculated cis populations of 14.7 and 14.2% and rotational barriers of 19.87 and 20.57 kcal/mol to the cis‐to‐trans isomerization for pSer‐Pro and pThr‐Pro peptides in water, respectively, are consistent with the observed values for pSer‐Pro and pThr‐Pro containing peptides from NMR experiments. However, the hydrogen bond between the prolyl nitrogen and the following amide NH group, which was suggested to be capable of catalyzing the prolyl isomerization, does not play a role in stabilizing the preferred transition state for the pSer/pThr‐Pro peptides in water. Instead, the amide hydrogen of the NHMe group is involved in a bifurcated hydrogen bond with the anionic oxygen and phosphoester oxygen of the phosphate group. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 330–339, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Development and validation of a HPLC method for determination of levonorgestrel and quinestrol in rat plasma
Authors: Tang Tao , Li Pingliang , Luo Laixin , Shi Dazhao , Li Jianqiang , Cao Yongsong 
Published: November 2009

AbstractLevonorgestrel and quinestrol, commonly known as EP‐1, has long been used in the control of wild rodents. Up to the present time, however, no method for simultaneous quantification of levonorgestrel and quinestrol in rat plasma has been reported. In the present study, a sensitive reverse‐phase high‐performance liquid chromatography with ultraviolet detection (RP‐HPLC‐UV) method for quantification of levonorgestrel and quinestrol in rat plasma has been developed. It uses a Kromasil ODS C18 column and acetonitrile‐0.1% formic acid (85 : 15, v/v) mobile phase at ambient temperature. The plasma sample was prepared by hexane–isoamyl alcohol extraction (90 : 10, v/v). The flow rate and detection wavelength were 1.0 mL/min and 230 nm. The correlation coefficients were greater than 0.9995 within 0.08–50 μg/mL for levonorgestrel and 0.12–50 μg/mL for quinestrol, and the limits of detection were 0.02 and 0.05 μg/mL for levonorgestrel and quinestrol, respectively. Average recovery ranged from 92.5 to 96.3% and inter‐day RSDs were less than 7.56%. This method can be applied to the further pharmacokinetic study of levonorgestrel and quinestrol in rat plasma. Copyright © 2009 John Wiley & Sons, Ltd.
In vitro and in vivo studies of androst‐4‐ene‐3,6,17‐trione in horses by gas chromatography–mass spectrometry
Authors: Leung Gary N. W. , Tang Francis P. W. , Wan Terence S. M. , Wong Colton H. F. , Lam Kenneth K. H. , Stewart Brian D. 
Published: November 2009

AbstractThis paper describes the application of gas chromatography–mass spectrometry (GC‐MS) for in vitro and in vivo studies of 6‐OXO in horses, with a special aim to identify the most appropriate target metabolite to be monitored for controlling the administration of 6‐OXO in racehorses. In vitro studies of 6‐OXO were performed using horse liver microsomes. The major biotransformation observed was reduction of one keto group at the C3 or C6 positions. Three in vitro metabolites, namely 6α‐hydroxyandrost‐4‐ene‐3,17‐dione (M1), 3α‐hydroxyandrost‐4‐ene‐6,17‐dione (M2a) and 3β‐hydroxyandrost‐4‐ene‐6,17‐dione (M2b) were identified. For the in vivo studies, two thoroughbred geldings were each administered orally with 500 mg of androst‐4‐ene‐3,6,17‐trione (5 capsules of 6‐OXO®) by stomach tubing. The results revealed that 6‐OXO was extensively metabolized. The three in vitro metabolites (M1, M2a and M2b) identified earlier were all detected in post‐administration urine samples. In addition, seven other urinary metabolites, derived from a further reduction of either one of the remaining keto groups or one of the remaining keto groups and the olefin group, were identified. These metabolites included 6α,17β‐dihydroxyandrost‐4‐en‐3‐one (M3a), 6,17‐dihydroxyandrost‐4‐en‐3‐one (M3b and M3c), 3β,6β‐dihydroxyandrost‐4‐en‐17‐one (M4a), 3,6‐dihydroxyandrost‐4‐en‐17‐one (M4b), 3,6‐dihydroxyandrostan‐17‐one (M5) and 3,17‐dihydroxyandrostan‐6‐one (M6). The longest detection time observed in urine was up to 46 h for the M6 metabolite. For blood samples, the peak 6‐OXO plasma concentration was observed 1 h post administration. Plasma 6‐OXO decreased rapidly and was not detectable 12 h post administration. Copyright © 2009 John Wiley & Sons, Ltd.
Staying safe: strategies for qualitative child abuse researchers
Authors: Coles Jan , Mudaly Neerosh 
Published: November 2009

AbstractUndertaking interview‐based research with victim/survivors of child abuse can be difficult and challenging for researchers. Much has been written about the impact of research on participants, but researcher effects are less explored. This paper reviews the literature on sensitive interview‐based research and child abuse research. The theoretical underpinnings of researcher trauma are outlined and challenges identified and related to child abuse research using researcher reflections from the authors' interview‐based research with children who have been abused and young mothers who were sexually abused in childhood. Strategies and recommendations are developed to minimise child abuse researcher trauma. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of supplementation with free glutamine and the dipeptide alanyl‐glutamine on parameters of muscle damage and inflammation in rats submitted to prolonged exercise
Authors: Cruzat Vinicius Fernandes , Rogero Marcelo Macedo , Tirapegui Julio 
Published: November 2009

AbstractIn this study, we investigated the effect of the supplementation with the dipeptide L‐alanyl‐L‐glutamine (DIP) and a solution containing L‐glutamine and L‐alanine on plasma levels markers of muscle damage and levels of pro‐inflammatory cytokines and glutamine metabolism in rats submitted to prolonged exercise. Rats were submitted to sessions of swim training for 6 weeks. Twenty‐one days prior to euthanasia, the animals were supplemented with DIP (n = 8) (1.5 g.kg−1), a solution of free L‐glutamine (1 g.kg−1) and free L‐alanine (0.61 g.kg−1) (G&A, n = 8) or water (control (CON), n = 8). Animals were killed at rest before (R), after prolonged exercise (PE—2 h of exercise). Plasma concentrations of glutamine, glutamate, tumour necrosis factor‐α (TNF‐α), prostaglandin E2 (PGE2) and activity of creatine kinase (CK), lactate dehydrogenase (LDH) and muscle concentrations of glutamine and glutamate were measured. The concentrations of plasma TNF‐α, PGE2 and the activity of CK were lower in the G&A‐R and DIP‐R groups, compared to the CON‐R. Glutamine in plasma (p < 0.04) and soleus muscle (p < 0.001) was higher in the DIP‐R and G&A‐R groups relative to the CON‐R group. G&A‐PE and DIP‐PE groups exhibited lower concentrations of plasma PGE2 (p < 0.05) and TNF‐α (p < 0.05), and higher concentrations of glutamine and glutamate in soleus (p < 0.001) and gastrocnemius muscles (p < 0.05) relative to the CON‐PE group. We concluded that supplementation with free L‐glutamine and the dipeptide LL‐alanyl‐LL‐glutamine represents an effective source of glutamine, which may attenuate inflammation biomarkers after periods of training and plasma levels of CK and the inflammatory response induced by prolonged exercise. Copyright © 2009 John Wiley & Sons, Ltd.
Template‐Synthesized Porous Silicon Carbide as an Effective Host for Zeolite Catalysts
Authors: Gu Lijun , Ma Ding , Yao Songdong , Liu Xiumei , Han Xiuwen , Shen Wenjie , Bao Xinhe 
Published: November 2009

AbstractA facile method has been developed for the fabrication of porous silicon carbide (SiC) by means of sintering a mixture of SiC powder and carbon pellets at a relatively lower temperature, that is, 1450 °C, in air. The pore density and the total pore volume of the resulting porous SiC could be tuned by changing the initial SiC/C weight ratio. The structure evolution and the associated property changes during the preparation were examined through X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, 29Si magic‐angle spinning (MAS) NMR spectroscopy, and mercury‐intrusion porosimetry analyses. Silica and SiOxCy ceramics formed in situ during the calcination process acted as binders of the porous SiC grains. The porous SiC can be used as a host for the growth of ZSM‐5 zeolite crystals to form the ZSM‐5/porous‐SiC composite material. After loading another catalytic active component of molybdenum, a novel catalytic material, Mo‐ZSM‐5/porous‐SiC, was obtained, which exhibited improved catalytic activity in the methane dehydroaromatization reaction.
Molecular tweezers for enantiodiscrimination in NMR: Di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl benzenedicarboxylates
Authors: Gil Sergio , Palomino‐Schätzlein Martina , Burusco Kepa Koldo , Jaime Carlos , Virgili Albert 
Published: November 2009

AbstractA series of new chiral molecular tweezers, di‐(R,R)‐1‐[10‐(1‐hydroxy‐2,2,2‐trifluoroethyl)‐9‐anthryl]‐2,2,2‐trifluoroethyl phthalate (2), isophthalate (3) and terephthalate (4), were synthesized and their structure studied by NMR and molecular mechanics. Their effectiveness as chiral solvating agents for the determination of the enantiomeric purity of chiral compounds using NMR was demonstrated. Chirality 2010. © 2009 Wiley‐Liss, Inc.
Experimental and computational studies of enantioseparation of structurally similar chiral compounds on amylose tris(3,5‐dimethylphenylcarbamate)
Authors: Kasat Rahul B. , Franses Elias I. , Wang Nien‐Hwa Linda 
Published: November 2009

AbstractThe enantioseparation of 14 structurally similar chiral solutes, with one or two chiral centers, are studied for a commercially important polysaccharide‐based chiral stationary phase, amylose tris(3,5‐dimethylphenylcarbamate) (ADMPC). Among these solutes, only two solutes show significant enantioresolutions of 2 to 2.5 in n‐hexane/2‐propanol (90/10, v/v) at 298 K. The retention factors of the chiral solutes vary significantly from 0.7 to 7.0, and they are compared with those of simpler nonchiral solutes having similar but fewer functional groups. The sorbent–solute H‐bonding interactions between the solute functional groups and the polymer CO and NH functional groups are probed with attenuated total reflection infrared spectroscopy (ATR‐IR). The H‐bonding interactions of the polymer CO and NH groups with the solutes result in changes in the IR amide band wavenumbers of ADMPC upon solute adsorption. The nanostructure of an ADMPC cavity and the potential interactions with the chiral solutes are proposed based on the sorbent–solute–solvent HPLC data, the sorbent–solute IR data, and the sorbent–solute molecular dynamics (MD) simulations. The results are consistent with the three point attachment hypothesis and indicate that a significant enantioresolution in ADMPC requires at least three different interaction sites for simultaneous H‐bonds and phenyl–phenyl interactions for phenylpropylamine (PPA) and various structurally similar chiral solutes. Chirality 2010. © 2009 Wiley‐Liss, Inc.
Estimation methods for time‐dependent AUC models with survival data
Authors: Hung Hung , Chiang Chin‐Tsang 
Published: November 2009

AbstractThe performance of clinical tests for disease screening is often evaluated using the area under the receiver‐operating characteristic (ROC) curve (AUC). Recent developments have extended the traditional setting to the AUC with binary time‐varying failure status. Without considering covariates, our first theme is to propose a simple and easily computed nonparametric estimator for the time‐dependent AUC. Moreover, we use generalized linear models with time‐varying coefficients to characterize the time‐dependent AUC as a function of covariate values. The corresponding estimation procedures are proposed to estimate the parameter functions of interest. The derived limiting Gaussian processes and the estimated asymptotic variances enable us to construct the approximated confidence regions for the AUCs. The finite sample properties of our proposed estimators and inference procedures are examined through extensive simulations. An analysis of the AIDS Clinical Trials Group (ACTG) 175 data is further presented to show the applicability of the proposed methods. The Canadian Journal of Statistics 38:8–26; 2010 © 2009 Statistical Society of Canada
Die Publikumsfrage in der Chemie‐Vorlesung
Authors: Fels Gregor 
Published: November 2009

AbstractWer kennt sie nicht, die Quizsendung „Wer wird Millionär”︁, bei der die Zuschauer im Studio über die Publikumsfrage aktiv am Quiz beteiligt werden? Technisch erfolgt das über ein „personal response system”︁ (PRS), mit dem sich registrieren und anzeigen lässt, wie viel Prozent der Zuschauer jeweils welche der vorgegebenen Antworten für die richtige Lösung hält. Da ist man auch als Zuschauer ganz bei der Sache, und sollte man einmal die Antwort nicht gewusst oder die Frage sogar falsch beantwortet haben, kann man trotzdem noch zufrieden sein, denn man hat ja nichts verloren, sondern im Gegenteil noch etwas dazu gelernt. So wie die Zuschauer über die Publikumsfrage in das Quiz einbezogen werden, können Dozenten die Studierenden mit Hilfe von PRS‐Verfahren aus ihrer traditionell passiven Rolle herausholen und aktiv an der Vorlesung beteiligen.
Rare incidence of congestive heart failure in gastrointestinal stromal tumor and other sarcoma patients receiving imatinib mesylate
Authors: Trent Jonathan C. , Patel Shalin S. , Zhang Jianhu , Araujo Dejka M. , Plana Juan‐Carlos , Lenihan Daniel J. , Fan Dominic , Patel Shreyaskumar R. , Benjamin Robert S. , Khakoo Aarif Y. 
Published: November 2009

AbstractBACKGROUND:The authors sought to determine the incidence and severity of cardiovascular toxicity caused by imatinib mesylate in gastrointestinal stromal tumor (GIST) and other sarcoma patients, and to explore cardiotoxicity caused by imatinib mesylate using cell culture and in vitro models.METHODS:To determine the incidence and significance of serious cardiac adverse events in GIST and other sarcoma patients receiving imatinib mesylate, the authors performed a retrospective analysis of 219 consecutive patients treated with imatinib mesylate. In vitro studies of imatinib mesylate on cultured cardiomyocytes and biochemical studies of cardiac lysates from mice treated with imatinib mesylate were performed to define the potential cardiotoxic effects of imatinib mesylate.RESULTS:Grade 3 or 4 potentially cardiotoxic adverse events (mostly edema or effusions) occurred in 8.2% of patients, were manageable with medical therapy, and infrequently required dose reduction or discontinuation of imatinib mesylate. Arrhythmias, acute coronary syndromes, or heart failure were uncommon, occurring in <1% of treated patients. However, administration of imatinib in a mouse model system resulted in inhibition of activation of protein kinases that are known to be important in the cardiac stress response.CONCLUSIONS:The authors concluded that imatinib is an uncommon cause of cardiotoxicity, and that the cardiovascular adverse events that occur are manageable when recognized and treated. Nevertheless, our preclinical findings suggest that imatinib remains a potential cardiotoxin. Furthermore, the cardiac consequences of long‐term imatinib therapy remain unknown. We therefore recommend treatment of risk factors for cardiovascular disease in imatinib‐treated patients in accord with the American Heart Association guidelines for the prevention and treatment of heart failure. Cancer 2010. © 2010 American Cancer Society.
Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations and risk for pancreatic adenocarcinoma
Authors: McWilliams Robert R. , Petersen Gloria M. , Rabe Kari G. , Holtegaard Leonard M. , Lynch Pamela J. , Bishop Michele D. , Highsmith W. Edward 
Published: November 2009

AbstractBACKGROUND:Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene are common in white persons and are associated with pancreatic disease. The purpose of this case‐control study was to determine whether CFTR mutations confer a higher risk of pancreatic cancer.METHODS:In a case‐control study, the authors compared the rates of 39 common cystic fibrosis‐associated CFTR mutations between 949 white patients with pancreatic adenocarcinoma and 13,340 white controls from a clinical laboratory database for prenatal testing for CFTR mutations. The main outcome measure was the CFTR mutation frequency in patients and controls.RESULTS:Overall, 50 (5.3%) of 949 patients with pancreatic cancer carried a common CFTR mutation versus 510 (3.8%) of 13,340 controls (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.04‐1.89; P = .027). Among patients who were younger when their disease was diagnosed (<60 years), the carrier frequency was higher than in controls (OR, 1.82; 95% CI, 1.14‐2.94; P = .011). In patient‐only analyses, the presence of a mutation was associated with younger age (median 62 vs 67 years; P = .034). In subgroups, the difference was seen only among ever‐smokers (60 vs 65 years, P = .028). Subsequent sequencing analysis of the CFTR gene detected 8 (16%) compound heterozygotes among the 50 patients initially detected to have 1 mutation.CONCLUSIONS:Carrying a disease‐associated mutation in CFTR is associated with a modest increase in risk for pancreatic cancer. Those affected appear to be diagnosed at a younger age, especially among smokers. Clinical evidence of antecedent pancreatitis was uncommon among both carriers and noncarriers of CFTR mutations. Cancer 2010. © 2010 American Cancer Society.
One‐Step Hydrothermal Synthesis of Nitrogen‐Doped Nanocarbons: Albumine Directing the Carbonization of Glucose
Authors: Baccile Niki , Antonietti Markus , Titirici Maria‐Magdalena 
Published: November 2009

AbstractWe present a simple and green one‐step pathway towards nitrogen‐doped carbon nanostructures with controlled mesoporosity through hydrothermal treatment of glucose in the presence of model proteins. Performing the reaction with different amounts of egg white ovalbumin protein (OvA), carbonaceous nanoparticles or continuous nanosponges with high specific surface areas can be efficiently produced. The nitrogen content of the structures is rather high (up to 8 wt %) and can be kept constant up to 950 °C, while oxygen elimination and graphitization of the carbon material occurs. We demonstrate here that sustainable natural resources can be efficiently used in the synthesis of pure high‐potential nanomaterials.
The diagnostic value of endobronchial ultrasound‐guided needle biopsy in lung cancer and mediastinal adenopathy
Authors: Sun Wei , Song Kunchang , Zervos Michael , Pass Harvey , Cangiarella Joan , Bizekis Costas , Crawford Bernard , Wang Beverly Y. 
Published: November 2009

AbstractEndobronchial ultrasonography (EBUS) has emerged as a new diagnostic tool that allows the bronchoscopist to see beyond the airway, including pulmonary and mediastinal lesion. The real time EBUS‐guided transbronchial needle aspiration (TBNA) has advanced the diagnostic yield in primary lung pathology and mediastinal lymph node staging of lung carcinoma. Sixty‐four patients (36 males, 28 females, ages ranging from 16 to 86 years) with peribronchial lung lesions and mediastinal and/or hilar lymph node lesions underwent EBUS‐TBNA. All patients had intraoperative cytological assessment by smears on aspiration samples or touch preparation on needle core biopsies.The cytological final diagnoses were categorized as negative, suspicious/positive, and non‐diagnostic. Forty‐nine samples were obtained from lymph node lesions and 15 samples were obtained from lung lesions. In cytology specimens, 32 patients had suspicious/positive diagnoses and 32 patients had negative diagnosis. In follow‐up histology specimens, 35 patients had malignant diagnoses, including 18 adenocarcinomas, 8 small cell carcinomas, 6 squamous cell carcinomas, 1 metastatic hepatocellular carcinoma, 1 metastatic melanoma, and 1 lymphoma. Twenty‐nine patients had negative diagnoses. Sensitivity and specificity were 88.9% and 96.4%, respectively. Positive and negative predictive values were 97.0% and 87.1%, respectively. Diagnostic accuracy was 92.2%. EBUS‐TBNA is an efficient and effective technique for diagnosis of intrapulmonary and mediastinal/hilar lymph nodes. It becomes significantly invaluable on clinical management for staging in those patients with lung cancer of other metastatic malignancies. This technique enables us to obtain tissue samples for quick diagnoses beyond central airway with minimal complications. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.
A rapid and efficient method of genotyping zebrafish mutants
Authors: Parant John M. , George Stephen A. , Pryor Rob , Wittwer Carl T. , Yost H. Joseph 
Published: November 2009

AbstractIn order to facilitate high throughput genotyping of zebrafish, we have developed a novel technique that uses High Resolution Melting Analysis (HRMA) to distinguish wild‐type, heterozygous mutants and homogyzous mutants. This one hour technique removes the need for restriction enzymes and agarose gels. The generated melting curve profiles are sensitive enough to detect non‐specific PCR products. We have been able to reliably genotype three classes of mutations in zebrafish, including point mutants, apchu745 (apcmcr), and p53zy7 (p53I166T), a small deletion mutant (bap28y75) and a retroviral insertion mutant (wdr43hi821a). This technique can genotype individual zebrafish embryos and adults (by tail‐clip) and is applicable to other model organisms. Developmental Dynamics 238:3168–3174, 2009. © 2009 Wiley‐Liss, Inc.
Micrographia and hypophonia in anorexia nervosa
Authors: Sekar Murali Krishnan , Arcelus Jon , Palmer Robert L. 
Published: November 2009

AbstractMicrographia is a condition, in which the sufferers write with small handwriting. Hypophonia is described as low volume speech. Both conditions have been described in neurological conditions, such as lesions in the deep white matter of the brain, Parkinson's disease etc., In this case report, we are presenting a 22‐years‐old female patient with anorexia nervosa who suffered from both these conditions. The patient also suffered from epilepsy. The onset of these symptoms, progress, and current status provides scope for discussing both the possible biological and psychodynamic etiology for these symptoms in this young woman. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010; 43:762–765