bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aryl Formate as Bifunctional Reagent: Applications in Palladium‐Catalyzed Carbonylative Coupling Reactions Using In Situ Generated CO
Authors: Li Haoquan , Neumann Helfried , Beller Matthias , Wu Xiao‐Feng 
Published: February 2014

AbstractAfter decades of development, carbonylation reactions have become one of the most powerful tools in modern organic synthesis. However, the requirement of CO gas limits the applications of such reactions. Reported herein is a versatile and practical protocol for carbonylative reactions which rely on the cooperation of phenyl formate and nonaflate, and the generation of CO in situ. This protocol has a high functional‐group tolerance and could be applied in carbonylations with C, N, and, O nucleophiles. The corresponding amides, alkynones, furanones, and aryl benzoates were synthesized in good yields.
Catalytic Asymmetric Transannulation of NH‐1,2,3‐Triazoles with Olefins
Authors: Kwok Sen Wai , Zhang Li , Grimster Neil P. , Fokin Valery V. 
Published: February 2014

AbstractA convenient one‐pot asymmetric synthesis of 2,3‐dihydropyrroles from in situ generated triflated triazoles and olefins is described that further expands the utility of azavinyl carbene chemistry and provides access to an important class of cyclic enamides. Mechanistic investigations support the involvement of triflated cyclopropylaldimine intermediates in the formation of 2,3‐dihydropyrrole. To the best of our knowledge, this is the first example of a chiral Brønsted acid catalyzed rearrangement of cyclopropylimines into enantioenriched 2,3‐dihydropyrroles.
Synthesis of cationic nickel(II) compounds for butadiene polymerization
Authors: Liu Li , Zhang Xu , Liu Heng , Zhang Xuequan , Sun Guangping , Zhang Hexin 
Published: February 2014

ABSTRACTA series of cationic nickel(II) compounds with various counter ions ([BF4]–, [CF3SO3]–) and N‐bearing ligands (1,10‐phenanthroline, benzimidazole and terpyridine) were synthesized. The simple compound, Ni(Phen)2Cl2, was prepared as a reference compound. All title compounds were characterized by elemental analysis, and infrared spectra analyses and compounds, some specific ones, were further examined by X‐ray crystallographic analysis. Upon treatment with ethylaluminum sesquichloride, these nickel(II) compounds exhibited high activities (up to 88.5%/4 h) for butadiene polymerization and afforded liquid polybutadiene (Mw < 30,000) with a high cis‐content (up to 92.1%). Various polymerization conditions were investigated in detail, and it was found that less steric hindrance of the ligands enhanced the catalytic activities of the nickel(II) compounds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40511.
Rheological behavior of cellulose nanocrystal suspension: Influence of concentration and aspect ratio
Authors: Wu Qiang , Meng Yujie , Wang Siqun , Li Yanjun , Fu Shenyun , Ma Lingfei , Harper David 
Published: February 2014

ABSTRACTThe steady and dynamic rheological behaviors of two cellulose nanocrystal (CNC) suspensions were investigated over a wide range of concentrations. The viscosity, storage and loss modules increased with increasing CNC concentration, and both CNC suspensions showed three regions in a viscosity‐concentration graph. The two critical concentrations depended on the aspect ratio and corresponded to the overlap and gelation concentration. Because of the higher aspect ratio, switchgrass CNC suspension transitioned into a biphasic state and formed a hydrogel at lower concentrations than those of cotton CNC suspensions. Furthermore, the complex viscosities of both CNC suspensions were higher than their steady viscosities; therefore, neither CNC suspension followed the Cox–Merz rule, which may be attributed to the existence of a liquid crystal domain in each suspension. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40525.
Increased 2,3‐butanediol production by changing codon usages in Escherichia coli
Authors: Park Seo‐Young , Kim Borim , Lee Soojin , Oh Minkyu , Won Jong‐In , Lee Jinwon 
Published: February 2014

AbstractThe natural microorganism Escherichia coli without modification is not suitable for the efficient production of 2,3‐butanediol (2,3‐BD) on an industrial scale because of its poor metabolic performance. Metabolic capacities of E. coli have been improved to produce 2,3‐BD efficiently, the performance of which is possible for producing such a product. Codon optimization with the ribosome‐binding site for the efficient production of target genes (budA and budC) was achieved by molecular engineering, which allowed the metabolic engineering to proceed to the next level. As a result, comparing the productivity in 26 H, where the amount of p18COR was 1.04 g/L and that of p18WTR was 0.41 g/L, represents an approximate 60.6% increase in the productivity of the p18WTR with codon optimization. In other words, p18COR was 2.54‐fold greater than p18WTR in the production of 2,3‐BD.
Anti‐senescence effect of FatI gene in goat somatic cells
Authors: Sun Xing‐Hong , Sun Xiao‐Feng , Ma Jin‐Mei , Liu Huan‐Qi , Min Ling‐Jiang , Pan Qing‐Jie , Qin Guo‐Qing , Shen Wei , Li Lan 
Published: February 2014

AbstractThe fatty acid dehydrogenase I (FatI) is able to express in mammalian cells and convert n‐6 polyunsaturated fatty acids (PUFAs) to n‐3 PUFAs. n‐3 PUFA is an important component of the cell membrane and plays an important role in the prevention and control of a variety of human diseases. However, n‐3 PUFAs cannot be endogenously synthesized by mammals because they lack the dehydrogenase that converts n‐6 to n‐3 PUFA. For the time being, gradually matured transgenic technology makes it possible to produce transgenic animals that are able to synthesize n‐3 PUFAs by themselves. However, the transgenic technology itself may bring negative impacts. In this study, the eukaryotic expression vector pcDNA3.1‐FatI was introduced into the genome of Boer goat fetal fibroblasts cultured in vitro, and the influence of biological characteristics of the fetal fibroblast was studied via overexpression of FatI. The results showed that the proliferation and apoptosis of cultured fetal fibroblast were not affected significantly by the overexpression of FatI using BrdU and TUNEL staining methods, respectively. Moreover, the overexpression of FatI significantly inhibited the senescence of somatic cells compared with enhanced green fluorescent protein (EGFP) transgenic cells (P < 0.01). Quantitative PCR revealed that the mRNA expression of P16 and P53 in the FatI transgenic cell group was significantly lower than that in the EGFP transgenic cell group (P < 0.01). In conclusion, the senescence of goat somatic cells was inhibited by the overexpression of the FatI gene.
Congenital anomalies identified at birth among infants born following assisted reproductive technology in colorado
Authors: Moses X.J. Ethan , Torres Tirsa , Rasmussen Anna , George Christopher 
Published: February 2014

BackgroundAssisted reproductive technology (ART) has assisted many infertile couples in conceiving. Despite increasing use in the United States, the association between ART and congenital anomalies remains a highly contested subject. We conducted a study to examine the risk of congenital anomalies among infants conceived using ART.MethodsA retrospective cohort study of 344,567 infants born in Colorado from 2007 to 2011 was conducted using data obtained from the Colorado Birth Certificate Database. The incidence of congenital anomalies identified at birth following conception with ART was assessed and compared with all naturally conceived infants born during the same time period. The odds ratio was calculated using multiple logistic regression after adjusting for multiple confounders.ResultsOf 2071 infants, 23 (1.11%) conceived using ART had a congenital anomaly identified at birth compared with 3826 (1.12%) of 342,496 infants conceived naturally. The adjusted odds ratio of a congenital anomaly among infants born following conception with ART was 1.01 (95% confidence interval, 0.67–1.52). The proportion of infants born following usage of ART in Colorado has not changed significantly (p = 0.20) from 2007 to 2011 with an overall proportion of 0.60% (range 0.52–0.64%), while the incidence of congenital anomalies has decreased significantly (p = 0.002) during the study years with an average of 1.12% (range, 0.92–1.25%).ConclusionThis study suggests that conception by means of ART is not associated with an increased risk of congenital abnormalities identified by birth certificate data in Colorado when compared with births following natural conception. Birth Defects Research (Part A) 100:92–99, 2014. © 2014 Wiley Periodicals, Inc.
One‐carbon metabolite levels in mid‐pregnancy and risks of conotruncal heart defects
Authors: Shaw Gary M. , Yang Wei , Carmichael Suzan L. , Vollset Stein Emil , Hobbs Charlotte A. , Lammer Edward J. , Ueland Per M. 
Published: February 2014

BackgroundEvidence exists for an association between use of vitamin supplements with folic acid in early pregnancy and reduced risk for offspring with conotruncal heart defects. A few observations have been made about nutrients related to one‐carbon metabolism other than folate. Our prospective study attempted to extend information on nutrition and conotruncal heart defects by measuring analytes in mid‐pregnancy sera.MethodsThis study included data from a repository of women's mid‐pregnancy serum specimens based on screened pregnancies in California from 2002–2007. Each woman's specimen was linked with delivery information to determine whether her fetus had a conotruncal heart defect or another structural malformation, or was nonmalformed. We identified 140 conotruncal cases and randomly selected 280 specimens as nonmalformed controls. Specimens were tested for a variety of analytes, including homocysteine, methylmalonic acid, folate, vitamin B12, pyridoxal phosphate, pyridoxal, pyridoxic acid, riboflavin, total choline, betaine, methionine, cysteine, cystathionine, arginine, asymmetric and symmetric dimethylarginine.Results and ConclusionsWe did not observe statistical evidence for substantial differences between cases and controls for any of the measured analytes.Analyses specifically targeting B‐vitamins also did not reveal differences between cases and controls. Birth Defects Research (Part A) 100:107–115, 2014. © 2014 Wiley Periodicals, Inc.
Classical endocannabinoid‐like compounds and their regulation by nutrients
Authors: Kleberg Karen , Hassing Helle A. , Hansen Harald S. 
Published: February 2014

AbstractEndocannabinoid‐like compounds are structurally related to the true endocannabinoids but do not contain highly unsaturated fatty acids, and they do not bind the cannabinoid receptors. The classical endocannabinoid‐like compounds include N‐acylethanolamines and 2‐monoacylglycerols, and their structural resemblance to the endocannabinoids makes them players in the endocannabinoid system, where they can interfere with the actions of the true endocannabinoids, because they in several cases engage the same synthesizing and degrading enzymes. In addition they have pharmacological actions of their own, which are particularly interesting in a nutritional and metabolic context. Exogenously supplied oleoylethanolamide, palmitoylethanolamide, and linoleoylethanolamide have anorexic effects, and the endogenous formation of these N‐acylethanolamines in the small intestine may serve an important role in regulating food intake, through signaling via PPARα and the vagus nerve to the brain appetite center. A chronic high‐fat diet will decrease intestinal levels of these anorectic N‐acylethanolamines and this may contribute to the hyperphagic effect of high‐fat diet; 2‐monoacylglycerols mediate endocrine responses in the small intestine; probably trough activation of GPR119 on enteroendocrine cells, and diet‐derived 2‐monoacylglycerols, for example, 2‐oleoylglycerol and 2‐palmitoylglycerol might be important for intestinal fat sensing. Whether these 2‐monoacylglycerols have signaling functions in other tissues is unclear at present. © 2014 BioFactors, 40(4):363–372, 2014
Repurposing of gallium‐based drugs for antibacterial therapy
Authors: Bonchi Carlo , Imperi Francesco , Minandri Fabrizia , Visca Paolo , Frangipani Emanuela 
Published: February 2014

AbstractWhile the occurrence and spread of antibiotic resistance in bacterial pathogens is vanishing current anti‐infective therapies, the antibiotic discovery pipeline is drying up. In the last years, the repurposing of existing drugs for new clinical applications has become a major research area in drug discovery, also in the field of anti‐infectives. This review discusses the potential of repurposing previously approved gallium formulations in antibacterial chemotherapy. Gallium has no proven function in biological systems, but it can act as an iron‐mimetic in both prokaryotic and eukaryotic cells. The activity of gallium mostly relies on its ability to replace iron in redox enzymes, thus impairing their function and ultimately hampering cell growth. Cancer cells and bacteria are preferential gallium targets due to their active metabolism and fast growth. The wealth of knowledge on the pharmacological properties of gallium has opened the door to the repurposing of gallium‐based drugs for the treatment of infections sustained by antibiotic‐resistant bacterial pathogens, such as Acinetobacter baumannii or Pseudomonas aeruginosa, and for suppression of Mycobacterium tuberculosis growth. The promising antibacterial activity of gallium both in vitro and in different animal models of infection raises the hope that gallium will confirm its efficacy in clinical trials, and will become a valuable therapeutic option to cure otherwise untreatable bacterial infections. © 2014 BioFactors, 40(3):303–312, 2014
Management of suspected anastomotic leak after bariatric laparoscopic Roux-en-y gastric bypass
Authors: Jacobsen H J , Nergard B J , Leifsson B G , Frederiksen S G , Agajahni E , Ekelund M , Hedenbro J , Gislason H 
Published: February 2014

Abstract

Background
Anastomotic leak is one of the most serious complications following bariatric laparoscopic Roux-en-Y gastric bypass (LRYGB), and associated with high morbidity rates and prolonged hospital stay. Timely management is of utmost importance for the clinical outcome. This study evaluated the approach to suspected leakage in a high-volume bariatric surgery unit.

Methods
All consecutive patients who underwent LRYGB performed by the same team of surgeons were registered prospectively in a clinical database from September 2005 to June 2012. Suspected leaks were identified based on either clinical suspicion and/or associated laboratory values, or by a complication severity grade of at least II using the Clavien–Dindo score.

Results
A total of 6030 patients underwent LRYGB during the study period. The leakage rate was 1·1 per cent (64 patients). Forty-five leaks (70 per cent) were treated surgically and 19 (30 per cent) conservatively. Eight (13 per cent) of 64 patients needed intensive care and the mortality rate was 3 per cent (2 of 64). Early leaks (developing in 5 days or fewer after LRYGB) were treated by suture of the defect in 20 of 22 patients and/or operative drainage in 13. Late leaks (after 5 days) were managed with operative drainage in 19 of 23 patients and insertion of a gastrostomy tube in 15. Patients who underwent surgical treatment early after the symptoms of leakage developed had a shorter hospital stay than those who had symptoms for more than 24 h before reoperation (12·5 versus 24·4 days respectively; P &lt; 0·001).

Conclusion
Clinical suspicion of an anastomotic leak should prompt an aggressive surgical approach without undue delay. Early operative treatment was associated with shorter hospital stay. Delays in treatment, including patient delay, after symptom development were associated with adverse outcomes.
Comparison of fluorodeoxyglucose uptake in symptomatic carotid artery and stable femoral artery plaques
Authors: Shaikh S , Welch A , Ramalingam S L , Murray A , Wilson H M , McKiddie F , Brittenden J 
Published: February 2014

Abstract

Background
Fluorine-18-labelled fluoroxdeoxyglucose (FDG) positron emission tomography (PET) has been used to evaluate atherosclerotic plaque metabolic activity, and through its uptake by macrophages is believed to have the potential to identify vulnerable plaques. The aims were to compare FDG uptake in carotid plaques from patients who had sustained a recent thromboembolic cerebrovascular event with that in femoral artery plaques from patients with leg ischaemia, and to correlate FDG uptake with the proportion of M1 and M2 macrophages present.

Methods
Consecutive patients who had carotid endarterectomy for symptomatic, significant carotid stenosis and patients with severe leg ischaemia and significant stenosis of the common femoral artery underwent FDG-PET and histological plaque analysis. The voxel with the greatest activity in the region of interest was calculated using the Patlak method over 60 min. Plaques were dual-stained for CD68, and M1 and M2 macrophage subsets.

Results
There were 29 carotid and 25 femoral artery plaques for study. The maximum dynamic uptake was similar in carotid compared with femoral plaques: median (range) 9·7 (7·1–12·2) versus 10·0 (7·4–16·6) respectively (P = 0·281). CD68 macrophage counts were significantly increased in carotid compared with femoral plaques (39·5 (33·9–50·1) versus 11·5 (7·7–21·3) respectively; P &lt; 0·001), as was the proportion of M1 proinflammatory macrophages. The degree of carotid stenosis correlated with the maximum dynamic FDG uptake (rs = 0·48, P = 0·008).

Conclusion
FDG uptake was no greater in symptomatic carotid plaques than in the less inflammatory femoral plaques. In patients on statin therapy. FDG uptake occurred in areas of significant arterial stenosis, irrespective of the degree of inflammation.
Design of a comprehensive biochemistry and molecular biology experiment: Phase variation caused by recombinational regulation of bacterial gene expression
Authors: Sheng Xiumei , Xu Shungao , Lu Renyun , Isaac Dadzie , Zhang Xueyi , Zhang Haifang , Wang Huifang , Qiao Zheng , Huang Xinxiang 
Published: February 2014

AbstractScientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about Salmonella enterica serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation, antibody agglutination test, and PCR analysis. Phase variation was observed by baterial motility assay and identified by antibody agglutination test and PCR analysis. This comprehensive experiment can be performed to help students improve their ability to use the knowledge acquired in Biochemistry and Molecular Biology. © 2014 by The International Union of Biochemistry and Molecular Biology, 42(3):XXXXX–XXXXX, 2014.
Problem‐solving test: Transport of a viral protein in a cell‐free system
Authors: Szeberényi József 
Published: February 2014

AbstractTerms to be familiar with before you start to solve the test: protein glycosylation, glycoprotein, endoplasmic reticulum, Golgi complex, mannose, oligosaccharide, free polysomes, cell fractionation, [35S]methionine; pulse labeling; nuclear fraction, mitochondrial fraction, microsomal fraction, cytosol, gel electrophoresis, autoradiography, trypsin, deoxycholate, detergent, sucrose density gradient, isopycnic gradient centrifugation © 2014 by The International Union of Biochemistry and Molecular Biology, 42(2):174–177, 2014
The role of kappa opioid receptors in stress‐induced reinstatement of alcohol seeking in rats
Authors: Funk Douglas , Coen Kathleen , Lê A. D. 
Published: February 2014

AbstractIntroductionStress is related to heavy alcohol use and relapse in alcoholics. Using the reinstatement model, we have shown that corticotropin‐releasing factor (CRF) underlies stress‐induced relapse to alcohol seeking in laboratory rodents. Little is known about how other neurotransmitters interact with CRF in these effects. Dynorphin and its receptor (kappa opioid receptor, KOR) are involved in stress responses and in alcohol seeking. KOR and CRF receptors (CRF R) may interact in the production of stress‐related behaviors but it is not known whether this interaction is involved in reinstatement of alcohol seeking.MethodsMale Long Evans rats were trained to self‐administer alcohol (12% w/v). After extinction of responding, we determined the effects of the KOR agonist, U50,488 (2.5, 5 mg/kg) on reinstatement of alcohol seeking, and their sensitivity to the selective KOR antagonist nor‐binaltorphimine dihydrochloride (nor‐BNI) (10 mg/kg) administered at different times before U50,488. We then examined the effects of nor‐BNI on reinstatement induced by the stressor yohimbine (1.25 mg/kg) and on reinstatement induced by exposure to alcohol‐associated cues . Finally, we determined whether CRF R1 blockade with antalarmin (10, 20 mg/kg) attenuates alcohol seeking induced by U50,488.ResultsU50,488 reinstated alcohol seeking. Prior treatment with nor‐BNI 2, but not 24 h before administration of U50,488 or yohimbine blocked reinstatement induced by these drugs. Cue‐induced reinstatement was blocked by nor‐BNI administered 2 h prior to testing. Finally, U50,488‐induced reinstatement was blocked by antalarmin.ConclusionsThese data further support a role for KOR in reinstatement of alcohol seeking under nonstress and stressful conditions and that KOR and CRF R interact in these effects.
Effect of TiO2 Surface Structure on the Hydrogen Production Activity of the Pt@CuO/TiO2 Photocatalysts for Water Splitting
Authors: Teng Fei , Chen Mindong , Li Na , Hua Xia , Wang Kai , Xu Tongguang 
Published: February 2014

AbstractCuO/TiO2 composites were prepared by the impregnation method, in which TiO2 nanosheets and nanorods are used as the precursors, respectively. We investigated the effect of the TiO2 surface structure on the activity and recyclability of the photocatalysts. The hydrogen production activities were tested in a 3 mol L−1 methanol aqueous solution under UV‐light irradiation. After deposition of Pt, both Pt@CuO/TiO2 samples displayed higher hydrogen production activities than the Pt/TiO2 samples. The results reveal that the TiO2 sheet‐based samples display higher hydrogen production activities and stability than the TiO2 rod‐based ones. It is proposed that a more stable p–n heterojunction form at the interface between CuO and TiO2 nanosheets owing to the strong interaction of CuO with the {0 0 1} facets of the TiO2 sheets, which significantly refrains the recombination rate of electrons and holes.
Thermodynamic Constraints for the Utilization of CO2
Authors: Müller Karsten , Mokrushina Liudmila , Arlt Wolfgang 
Published: February 2014

AbstractThe production of chemical compounds from carbon dioxide could be a way to reduce this major greenhouse gas and gain a cheap raw material base. A variety of potential reactions might be suitable from a chemical point of view, but the low energetic level of carbon dioxide leads to severe limitations of the thermodynamic equilibrium. Most carbon dioxide utilization reactions are therefore not meaningful for an implementation outside the laboratory. This article gives an overview of the potential reactions to produce fine chemicals from carbon dioxide and their thermodynamic feasibility.