bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and properties of poly(tetrafluoroethylene)/calcium carbonate hybrid porous membranes
Authors: Huang Qinglin , Xiao Changfa , Hu Xiaoyu 
Published: December 2011

AbstractPoly(tetrafluoroethylene) (PTFE)/calcium carbonate (CaCO3) hybrid porous membranes were prepared from a mixture of PTFE emulsion and nanoscale CaCO3 particles by using polyvinyl alcohol as the fiber forming polymer. The interfacial microvoids (IFMs) were obtained owing to the different mechanical properties of PTFE and CaCO3. Effects of CaCO3 contents and membrane draw ratios on membranes structure and properties were investigated. Results showed that: (1) as the CaCO3 content increase, the membrane hydrophobicity improved owing to the increasing of membranes surface roughness, (2) the membrane porosity and pure water flux increased as the CaCO3 content and membrane draw ratios increasing. By the membrane morphology configuration with scanning electron microscopy, it was found that the IFMs quantity and pore size improved obviously with the draw ratios increasing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Systematic review of intraoperative cholangiography in cholecystectomy
Authors: Ford J A , Soop M , Du J , Loveday B P T , Rodgers M 
Published: December 2011

Abstract

Background
Intraoperative cholangiography (IOC) is used to detect choledocholithiasis and identify or prevent bile duct injury. The aim of this study was systematically to review the randomized clinical trials of IOC for these two indications.

Methods
MEDLINE, Embase, the Cochrane Library, clinicaltrials.gov and the World Health Organization database of clinical trials were searched systematically (January 1980 to February 2011) to identify trials. Two authors performed the literature search and extracted data independently. Primary endpoints were bile duct injury and retained common bile duct (CBD) stones diagnosed at any stage after surgery. Preliminary meta-analysis was undertaken, but the trials were too methodologically heterogeneous and the outcome events too infrequent to allow meaningful meta-analysis.

Results
Eight randomized trials were identified including 1715 patients. Six trials assessed the value of routine IOC in patients at low risk of choledocholithiasis. Two trials randomized all patients (including those at high risk) to routine or selective IOC. Two cases of major bile duct injury were reported, and 13 of retained CBD stones. No trial demonstrated a benefit in detecting CBD stones. IOC added a mean of 16 min to the total operating time.

Conclusion
There is no robust evidence to support or abandon the use of IOC to prevent retained CBD stones or bile duct injury. Level 1 evidence for IOC is of poor to moderate quality. None of the trials, alone or in combination, was sufficiently powered to demonstrate a benefit of IOC. Further small trials cannot be recommended.
Axillary recurrence rate 5 years after negative sentinel node biopsy for breast cancer
Authors: Andersson Y , de Boniface J , Jönsson P-E , Ingvar C , Liljegren G , Bergkvist L , Frisell J 
Published: December 2011

Abstract

Background
Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection (ALND) as the standard axillary staging procedure in breast cancer. Follow-up studies in SLN-negative women treated without ALND report low rates of axillary recurrence, but most studies have short follow-up, and few are multicentre studies.

Methods
Between September 2000 and January 2004, patients who were SLN-negative and did not have ALND were included in a prospective cohort. Kaplan-Meier estimates were used to analyse the rates of axillary recurrence and survival. The risk of axillary recurrence was also compared in centres with high and low experience with the SLN biopsy (SLNB) technique.

Results
A total of 2195 patients with 2216 breast tumours were followed for a median of 65 months. Isolated axillary recurrence was diagnosed in 1·0 per cent of patients. The event-free 5-year survival rate was 88·8 per cent and the overall 5-year survival rate 93·1 per cent. There was no difference in recurrence rates between centres contributing fewer than 150 SLNB procedures to the cohort and centres contributing 150 or more procedures.

Conclusion
This study confirmed the low risk of axillary recurrence 5 years after SLNB for breast cancer without ALND.
First chemoenzymatic synthesis of (+)‐2‐carboxypyrrolidine‐3‐acetic acid, the nucleus of kainoid amino acids
Authors: Felluga Fulvia , Forzato Cristina , Nitti Patrizia , Pitacco Giuliana , Ghelfi Franco , Valentin Ennio 
Published: December 2011

AbstractThe distinctive nucleus of kainoid amino acids, (2S,3R)‐(+)‐2‐carboxypyrrolidine‐3‐acetic acid 6, was synthesized by a chemoenzymatic process, exploiting the diastereomeric cis/trans methyl pyroglutamate derivatives 10a, 10b, 10c/11a, 11b, 11c as key intermediates. These mixtures, when subjected to a kinetic resolution mediated by α‐chymotrypsin, reacted diastereo‐, regio‐, and enantioselectively to give the trans derivatives (+)‐10a, 10b, 10c possessing the correct (2S,3R) configuration. Subsequently, the desired product (2S,3R)‐(+)‐6 could be obtained after well‐established transformations. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Chiral calix[4]arenes bearing amino alcohol functionality as membrane carriers for transport of chiral amino acid methylesters and mandelic acid
Authors: Bozkurt Selahattin , Yilmaz Mustafa , Sirit Abdulkadir 
Published: December 2011

AbstractNovel chiral calix[4]arene derivatives bearing amino alcohol moieties at the lower rim have been synthesized from the reaction of p‐tert‐butylcalix[4]arene diester with various amino alcohols. The transport of amino acid esters (phenylglycine, phenylalanine, and tryptophan methyl esters hydrochloride) and mandelic acid were studied through chloroform bulk liquid membrane system using chiral calix[4]arenes 15, 16, 17, 18, 19, 20. All these receptors have been found to act as carriers for transport of aromatic amino acid methylesters and mandelic acid from the aqueous source phase to the aqueous receiving phase. The influence of calixarene and guest structures upon transport through liquid membrane is discussed. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Enantioselective toxicity of metolachlor to scenedesmus obliquus in the presence of cyclodextrins
Authors: Liu Hui J. , Cai Wei D. , Huang Ruo N. , Xia Hui L. , Wen Yue Z. 
Published: December 2011

AbstractCyclodextrins (CDs) possess a variety of chiral centers and are capable of recognizing enantiomeric molecules through the formation of inclusion complexes. Two types of CDs, α‐cyclodextrin (α‐CD) and β‐cyclodextrin (β‐CD), were selected to evaluate the effects of the enantioselective ecotoxicity of racemic metolachlor (Rac‐metolachlor) and its S‐enantiomer (S‐metolachlor) on the freshwater algae Scenedesmus obliquus (S. obliquus) by acute toxicity test. The results showed that the aquatic toxicity of S‐metolachlor was higher than Rac‐metolachlor and that CDs enhanced the toxicity of metolachlor enantioselectively by increasing the aquatic toxicity of Rac‐metolachlor rather than that of S‐metolachlor to S. obliquus. The equilibrium constant for Rac‐metolachlor‐CD complexes was higher than that of S‐metolachlor‐CDs, which was responsible for the greater aquatic toxicity shift effect of Rac‐metolachlor. Thermodynamic studies of CD complexes showed that inclusion for all of the complexes was primarily a spontaneous, enthalpy‐driven process. These results will help to understand the preliminary mechanism of shifting aquatic toxicity of metolachlor by CDs and the CDs mediated environmental processes of metolachlor, to correctly apply CDs to chiral pesticides formulation and environmental remediation of chiral contaminants. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Effect of trichlorobenzene additive on the performance and morphology of polyfluorene and fullerene derivative bulk heterojunction solar cells
Authors: Koetniyom W. , Keawprajak A. , Piyakulawat P. , Jiramitmongkon K. , Nukeaw J. , Pratontep S. , Asawapirom U. 
Published: December 2011

AbstractThe influence of additive, namely 1,3,5‐trichlorobenzene (TCB), on the morphology and performance of bulk heterojunction (BHJ) organic solar cells was studied based on a 1:2 (w/w) blend of benzothiadiazole/thiophene‐based copolymers (PFTBzTT) to [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM). The active layers were deposited by spin‐coating from solutions using chloroform, with different additive concentrations from 0 to 36 mg/ml. The addition of solvent additive into the polymer solution was able to improve the performance of BHJ solar cells. The maximum power conversion efficiency (%PCE) of 0.85% was obtained for a cell with the TCB concentration of 12 mg/ml after annealing at 180°C for 20 min. From atomic force microscopy (AFM) images, the films processed without TCB appear smoother than those with the TCB additive. A large extent of segregation was also observed in the films processed with a high TCB concentration. The optical images of the thin films suggest that the optimum concentrations of the additive cause the polymer self‐organisation, resulting in some aggregation of large PCBM crystals. © 2011 Canadian Society for Chemical Engineering
Mapping of Surface‐Enhanced Fluorescence on Metal Nanoparticles using Super‐Resolution Photoactivation Localization Microscopy
Authors: Lin Hongzhen , Centeno Silvia P. , Su Liang , Kenens Bart , Rocha Susana , Sliwa Michel , Hofkens Johan , Uji‐i Hiroshi 
Published: December 2011

AbstractPhotoactivation localization microscopy (PALM) was applied to study surface‐enhanced fluorescence (SEF) on metal nanostructures (SEF‐PALM). The detection of fluorescence from individual single molecules can be used to image the point‐spread‐function and spatial distribution of the fluorescence emitted in the vicinity of a metal surface. Due to the strong scattering effect, the angular distribution of the fluorescence is altered by metals, resulting in a spatial shift of fluorescence spots with respect to the metal nanostructures, and has to be taken into account in the analysis. SEF‐PALM can be used to discriminate effects of labelling density when estimating the enhancement factor in SEF. Furthermore, nanostructures with sizes below the diffraction limit can be resolved using this technique. SEF‐PALM is established as a powerful tool to study plasmon‐mediated phenomena on metal nanostructures.
A Cyano‐Bridged Vanadium–Niobium Bimetal Assembly Exhibiting a High Curie Temperature of 210 K
Authors: Imoto Kenta , Takemura Miho , Tokoro Hiroko , Ohkoshi Shin‐ichi 
Published: December 2011

AbstractWe report a cyano‐bridged V–Nb bimetal assembly, K0.59VII1.59VIII0.41[NbIV(CN)8]·(SO4)0.50·6.9H2O, exhibiting ferrimagnetism with a high Curie temperature (TC) of 210 K, which is the highest TC value among those of octacyano‐bridged bimetal assemblies. Such a high TC value originates from the high coordination number of octacyanoniobate and the strong superexchange interaction between VII (S = 3/2) and NbIV (S = 1/2) through the CN groups.
Tandem Reactions Leading to Benzo[c]chromen‐6‐ones and 3‐Substituted Isocoumarins
Authors: Fan Xuesen , He Yan , Cui Liangyan , Guo Shenghai , Wang Jianji , Zhang Xinying 
Published: December 2011

AbstractA simple and convenient protocol for the synthesis of benzo[c]chromen‐6‐ones and 3‐substituted isocoumarins through a CuI‐catalyzed tandem reaction of 2‐bromobenzoates withcyclohexane‐1,3‐diones or acyclic 1,3‐diones is developed. This strategy can also be extended to the one‐pot synthesis of isoquinolin‐1(2H)‐one and 3,4‐dihydrophenanthridine‐1,6(2H,5H)‐dione.
Dissociable pathways facilitate theta and non‐theta states in the median raphe—Septohippocampal circuit
Authors: Crooks Robert , Jackson Jesse , Bland Brian H. 
Published: December 2011

AbstractHippocampal theta rhythms in vivo are modulated by a synchronizing projection from the medial septum (MS) and a desynchronizing input from the median raphe nucleus (MRn) of the brainstem. Inactivation of the MS suppresses theta rhythms while inactivation of the median raphe produces persistent theta. However, different pathways arise from within the MS and the median raphe and therefore different brain states could be facilitated by different forms of median raphe or septohippocampal inputs. Here, we found in urethane anesthetized rats that suppression of outputs from the MRn with procaine leads to persistent hippocampal theta as previously reported. The discharge properties of hippocampal theta‐related cells recorded during both spontaneously occurring theta and MRn 8‐OH‐DPAT‐induced theta did not differ significantly. This persistent theta was abolished by inactivation of the MS with either procaine or atropine sulfate. Selective inactivation of serotonergic median raphe outputs with the 5‐HT‐1A agonist (8‐OH‐DPAT) induced theta that was also abolished by medial septal inactivation using procaine. Thus, persistent theta following complete median raphe inactivation or selective serotonergic inactivation arises from a median raphe to MS pathway. However, 8‐OH‐DPAT infusions into the median raphe together with atropine infusions in the MS did not abolish theta activity. These data suggest that the non‐serotonergic (possibly glutamatergic) median raphe projections to the MS can facilitate the generation of hippocampal theta in the absence of medial septal cholinergic tone. These results demonstrate that dissociable neuronal pathways in the median raphe–MS–hippocampal circuit promote different brain states (theta or non‐theta) and a median raphe non‐serotonergic (likely glutamatergic) system may serve a separate function from the ascending serotonergic raphe projection in the regulation of hippocampal network activity. © 2011 Wiley Periodicals, Inc.
Hiding in plain view: Lesions of the medial temporal lobe impair online representation
Authors: Warren David E. , Duff Melissa C. , Jensen Unni , Tranel Daniel , Cohen Neal J. 
Published: December 2011

AbstractThe hippocampus is necessary for the normal formation of enduring declarative memories, but its role in cognitive processes spanning short intervals is less well understood. Within the last decade, several reports have described modest behavioral deficits in medial temporal lobe (MTL)‐lesion patients when they perform tasks that do not seem likely to rely on enduring memory. An intriguing but sparsely‐tested implication of such results is that the MTL is involved in the online representation of information, possibly of an associative/relational nature, irrespective of delay. We administered several tests that simultaneously presented all information necessary for accurate responses to a group of MTL‐lesion patients with severe declarative memory deficits but otherwise normal cognition, and to matched brain‐damaged and healthy comparison participants. MTL‐lesion patients performed less well than either comparison group in the Hooper Visual Organization Test, and several patients performed outside the normal range on the Overlapping Figures Test. A novel follow‐up borrowing characteristics of the Overlapping Figures Test revealed impaired identification of novel items by MTL‐lesion patients when target items were obscured by distracters, and two additional novel tests of fragmented object identification further implicated the hippocampus/MTL in the integration of information across very brief intervals. These findings suggest that MTL structures including the hippocampus contribute similarly to cognition irrespective of timescale. © 2011 Wiley Periodicals, Inc.
Metadislocations in Complex Metallic Alloys and their Relation to Dislocations in Icosahedral Quasicrystals
Authors: Feuerbacher Michael , Heggen Marc 
Published: December 2011

AbstractComplex metallic alloys and quasicrystals are closely related. Both possess icosahedral local order, but while in quasicrystals the long‐range order and hence the macroscopic structure is also icosahedral, in complex metallic alloys a periodic structure with large lattice parameters is formed. Metadislocations are novel and highly complex structural defects in complex metallic alloys. Focusing on metadislocations in ε‐type phases, we will review the basic geometric concepts of metadislocations and the relation between the number of phason planes, Burgers vector, and the elastic energy. The properties of dislocations in icosahedral Al‐Pd‐Mn will briefly be recalled and discussed in relation to metadislocations.
High doses of 2,2′‐dithienyl diselenide cause systemic toxicity in rats: an in vitro and in vivo study
Authors: Chagas Pietro Maria , Bortolatto Cristiani Folharini , Wilhelm Ethel Antunes , Nogueira Cristina Wayne 
Published: December 2011

ABSTRACTOrganoselenium compounds have important pharmacological properties. However, these compounds can cause toxicity, typically related to oxidation of endogenous thiols. The aim of this study was to investigate whether 2,2′‐dithienyl diselenide (DTDS) has potential toxicity in vitro and in vivo. Therefore, sulfhydryl‐containing enzyme activities, δ‐aminolevulinic acid dehydratase (δ‐ALA‐D) and Na+–K+‐ATPase were used to predict DTDS toxicity in rat brain homogenate in vitro. In in vivo experiments, a DTDS administration (50 or 100 mg kg−1, p.o.) to rats was performed and toxicological parameters were determined. DTDS inhibited δ‐ALA‐D (IC50 2 µm) and Na+–K+‐ATPase (IC50 17 µm) activities in vitro. The inhibitory effect of DTDS on δ‐ALA‐D and Na+–K+‐ATPase activities was restored by dithiothreitol. DTDS (5–25 µm) elicited a thiol oxidase‐like activity. In vivo, DTDS (50 and 100 mg kg−1) caused systemic toxicity, evidenced by a decrease in water and food intakes and body weight gain, as well as the death of rats. DTDS at the dose of 100 mg kg−1 increased plasma alanine and aspartate aminotransferase activities and decreased urea levels. At 50 and 100 mg kg−1, it increased lipid peroxidation levels. At the highest dose, DTDS inhibited δ‐ALA‐D activity. By contrast, Na+–K+‐ATPase activity and antioxidant defense were not altered in the brains of rats exposed to DTDS. In conclusion, interaction with the cisteinyl residues seems to mediate the inhibitory effect of DTDS on sulfhydryl‐containing enzymes in vitro. In addition, high oral doses of DTDS induce toxicity in rats. Copyright © 2011 John Wiley & Sons, Ltd.
Toxicokinetic modeling of folpet fungicide and its ring‐biomarkers of exposure in humans
Authors: Heredia‐Ortiz Roberto , Berthet Aurélie , Bouchard Michèle 
Published: December 2011

ABSTRACTA human in vivo toxicokinetic model was built to allow a better understanding of the toxicokinetics of folpet fungicide and its key ring biomarkers of exposure: phthalimide (PI), phthalamic acid (PAA) and phthalic acid (PA). Both PI and the sum of ring metabolites, expressed as PA equivalents (PAeq), may be used as biomarkers of exposure. The conceptual representation of the model was based on the analysis of the time course of these biomarkers in volunteers orally and dermally exposed to folpet. In the model, compartments were also used to represent the body burden of folpet and experimentally relevant PI, PAA and PA ring metabolites in blood and in key tissues as well as in excreta, hence urinary and feces. The time evolution of these biomarkers in each compartment of the model was then mathematically described by a system of coupled differential equations. The mathematical parameters of the model were then determined from best fits to the time courses of PI and PAeq in blood and urine of five volunteers administered orally 1 mg kg−1 and dermally 10 mg kg−1 of folpet. In the case of oral administration, the mean elimination half‐life of PI from blood (through feces, urine or metabolism) was found to be 39.9 h as compared with 28.0 h for PAeq. In the case of a dermal application, mean elimination half‐life of PI and PAeq was estimated to be 34.3 and 29.3 h, respectively. The average final fractions of administered dose recovered in urine as PI over the 0–96 h period were 0.030 and 0.002%, for oral and dermal exposure, respectively. Corresponding values for PAeq were 24.5 and 1.83%, respectively. Finally, the average clearance rate of PI from blood calculated from the oral and dermal data was 0.09 ± 0.03 and 0.13 ± 0.05 ml h−1 while the volume of distribution was 4.30 ± 1.12 and 6.05 ± 2.22 l, respectively. It was not possible to obtain the corresponding values from PAeq data owing to the lack of blood time course data. Copyright © 2011 John Wiley & Sons, Ltd.
Deoxyactein Isolated from Cimicifuga racemosa protects osteoblastic MC3T3‐E1 cells against antimycin A‐induced cytotoxicity
Authors: Choi Eun Mi 
Published: December 2011

ABSTRACTDeoxyactein is one of the major constituents isolated from Cimicifuga racemosa. In the present study, we investigated the protective effects of deoxyactein on antimycin A (mitochondrial electron transport inhibitor)‐induced toxicity in osteoblastic MC3T3‐E1 cells. Exposure of MC3T3‐E1 cells to antimycin A caused significant cell viability loss, as well as mitochondrial membrane potential dissipation, complex IV inactivation, ATP loss, intracellular calcium ([Ca2+]i) elevation and oxidative stress. Pretreatment with deoxyactein prior to antimycin A exposure significantly reduced antimycin A‐induced cell damage by preventing mitochondrial membrane potential dissipation, complex IV inactivation, ATP loss, [Ca2+]i elevation and oxidative stress. Moreover, deoxyactein increased the activation of PI3K (phosphoinositide 3‐kinase), Akt (protein kinase B) and CREB (cAMP‐response element‐binding protein) inhibited by antimycin A. All these data indicate that deoxyactein may reduce or prevent osteoblasts degeneration in osteoporosis or other degenerative disorders. Copyright © 2011 John Wiley & Sons, Ltd.
Determination of Cadmium and Lead in Human Teeth Samples Using Dispersive Liquid‐liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry
Authors: Zhang Chunyan , Wang Yining , Cheng Xiangrong , Xia Haibin , Liang Pei 
Published: December 2011

AbstractA new method for the determination of cadmium and lead in human teeth was developed based on dispersive liquid‐liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry determination. In the proposed approach, O,O‐diethyldithiophosphate (DDTP) was used as a chelating agent, and carbon tetrachloride and methanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of cadmium and lead and their subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of 116 and 68 for cadmium and lead were achieved. The detection limit for cadmium and lead was 5.6 and 45 ng L−1, and the relative standard deviation (R.S.D) was 4.5% and 3.8% (n = 7, c = 1.0 ng mL−1), respectively. Verification of the accuracy of the method was carried out by analysis of a standard reference material (NIST 1486, bone meal). The method was successfully applied to the determination of trace amount of cadmium and lead in human teeth samples with satisfactory results.
Synthesis of novel pyrazolo[3,4‐d]pyrimidines peri‐fused with 1,4‐diazepine, 1,4‐thiazepine, and 1,2,4‐triazepine rings
Authors: Masevicius Viktoras , Juskenas Robertas , Tumkevicius Sigitas 
Published: December 2011

AbstractA simple and efficient synthesis of novel ortho‐ and peri‐annulated heterocyclic systems—2,6,7,9‐tetrahydro‐8H‐pyrazolo[5,4,3‐de]pyrimido[4,5‐e][1,4]diazepine, 2,6,7,9‐tetrahydro‐8H‐pyrazolo[5,4,3‐de]pyrimido [5,4‐f][1,4]thiazepine, and 6,9‐dihydro‐2H‐pyrazolo[3,4,5‐ef]pyrimido[5,4‐f][1,2,4]triazepine is described. J. Heterocyclic Chem.,, (2012).