bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper(0)‐mediated radical copolymerization of vinyl acetate and acrylonitrile in DMSO at ambient temperature
Authors: Yu Huali , Wu Yang , Gao Jinlong , Wang Wenxiang , Zhang Zhengbiao , Zhu Xiulin 
Published: August 2012

AbstractIn this work, Cu(0)‐mediated radical copolymerization of vinyl acetate (VAc) and acrylonitrile (AN) was explored. The polymerization was carried out at 25°C with 2,2′‐bipyridine as ligand and dimethyl sulfoxide as solvent. The copolymerization proceeded smoothly producing moderately controlled molecular weights at low VAc feed ratios. The high VAc feed ratios generated low polymerization rate and poorly controlled molecular weights. FTIR, 1H NMR, and differential scanning calorimetry confirmed the successful obtaining of the copolymers. Based on 1H NMR spectra, the reactivity ratios of VAc and AN were calculated to be 0.003 and 1.605, respectively. This work conveyed the first example for the Cu(0)‐mediated radical polymerization of AN and VAc, wherein VAc cannot be homopolymerized by Cu(0)‐mediated radical polymerization technique. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Collapse‐expansion transition of elastic shell induced by grafted polymer chains
Authors: Chai Aihua , Zhang Dong , Chen Hongping , Wen Xiaohui , He Linli , Zhang Linxi 
Published: August 2012

AbstractA coarse‐grained model for an elastic shell grafted with polymer chains is investigated by molecular dynamics methods. With increasing the number of grafted polymer chains (GPCs), it is found that the conformation of the shell undergoes from expansion to collapse and back to the expansion. By varying the density of the GPCs, the phase transition of the elastic shell can be successfully controlled at moderate bending energy of the shell and at moderate binding energy between the shell and GPCs. Furthermore, the self‐assembly structures of the GPCs are also affected by the elastic shell in certain conditions. In the case of a few GPCs on the shell, the chains tend to be adsorbed on the shell surface unfolded at high value of bending energy. However, when the bending energy is small, the chains can be folded several times easily. This may be an important step toward a deeper understanding of how to control the microstructure in the production of biocomposites. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Polar phase formation in poly(vinylidene fluoride) induced by melt annealing
Authors: Pan Huayan , Na Bing , Lv Ruihua , Li Chun , Zhu Jie , Yu Zhiwei 
Published: August 2012

AbstractIt is still a challenge to obtain polar phase of poly(vinylidene fluoride) from melt crystallization at normal conditions. This study demonstrates that polar β‐ and γ phases can be produced through melting re‐crystallization of α phase, provided that moderate memory effects in the melt is achieved by annealing. Otherwise, it is inevitable to re‐crystallize into α phase without any trace of polar phase. Small fragments, generated from the disintegration of long TGTG′ sequences, most likely adopt trans conformation in the melt before approaching random coils, thus responsible for the formation of polar phase upon cooling. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Experimental Methodology for Obtaining the Flow Curve of Sheet Materials in a Wide Range of Strains
Authors: Zhuang Xincun , Zhao Zhen , Li Hongye , Xiang Hua 
Published: August 2012

AbstractAn experimental approach for determining the stress–strain curve over a large range of strains through tensile test is introduced. The novel aspect of the proposed approach is to apply different degrees of cold working on the sheet metal specimens before tensile test. By adding the pre‐strain derived from cold working to the strain from tensile test, the corresponding stress–strain curves can be shifted to large strains. Since the variation trend of these curves is in high coincidence with the results from compression test, it is convinced that the stress–strain curve of tensile test over a large range of strains can be experimentally extrapolated based on such an approach, especially aiming at medium‐thick sheet metal. Based on the tensile test results, five different extrapolation models were evaluated with respect to different sampling dataset. It was revealed that the true stress–plastic strain curve over a given strain range could be approximated well by the extrapolation models of Ludwik, Ghosh, and Hocket‐Sherby based on sampling data points of standard tensile test combined with a prescribed data point from tensile test after cold working.
Science teachers and scientific argumentation: Trends in views and practice
Authors: Sampson Victor , Blanchard Margaret R. 
Published: August 2012

AbstractCurrent research indicates that student engagement in scientific argumentation can foster a better understanding of the concepts and the processes of science. Yet opportunities for students to participate in authentic argumentation inside the science classroom are rare. There also is little known about science teachers' understandings of argumentation, their ability to participate in this complex practice, or their views about using argumentation as part of the teaching and learning of science. In this study, the researchers used a cognitive appraisal interview to examine how 30 secondary science teachers evaluate alternative explanations, generate an argument to support a specific explanation, and investigate their views about engaging students in argumentation. The analysis of the teachers' comments and actions during the interview indicates that these teachers relied primarily on their prior content knowledge to evaluate the validity of an explanation rather than using available data. Although some of the teachers included data and reasoning in their arguments, most of the teachers crafted an argument that simply expanded on a chosen explanation but provided no real support for it. The teachers also mentioned multiple barriers to the integration of argumentation into the teaching and learning of science, primarily related to their perceptions of students' ability levels, even though all of these teachers viewed argumentation as a way to help students understand science. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 1122–1148, 2012
Synthesis, Structure, Photoluminescence and Thermal Properties of Sodium Ethene‐Bis‐Nitrobenzenesulfonate
Authors: Yu Yan‐Hong , Qian Kun , Wang Xing‐Cong 
Published: August 2012

AbstractAbstract. Sodium ethene‐bis‐nitrobenzenesulfonate, [Na2(ENS)·6H2O]n(1) was synthesized through coupling reaction of o‐nitrotoluenesulfonic acid in NaOH solution and characterized by single crystal X‐ray diffraction, elemental analysis, IR and 1H NMR spectroscopy, XRPD, DSC and TGA (where ENS2– = ethene‐bis‐nitrobenzenesulfonate). The asymmetrical unit of (1) consists of two octahedral NaI ions, and the neighboring metal centers are bridged by μ2 water molecules resulting in the formation of an inorganic tetranuclear unit. The tetranuclear units were connected through the ENS2– ligands into a 2D topology net. The weak π–π stacking and H‐bonding interactions further stabilized the structure. The crystals of (C7H6NO5S)–·(H5O2)+ (2) were obtained by post‐processing the unreacted raw material to recycle. Furthermore, the rigidity and the conjugation effect of the aromatic system in compound 1 were increased through the coordination interactions of metal atoms to ligands, resulting in the emission coming from ligand enhanced with red‐shifting about 9 nm of the maximal wavelength. The conjugation effects and the steric arrangement of the substituent groups play the main role to the luminescence intensity and red‐shift effect.
Mechanical reproductive isolation via divergent genital morphology betweenCarabus insulicolaandC. esakiiwith implications in species coexistence
Authors: Kubota Kôhei , Miyazaki Kôji , Ebihara Shiho , Takami Yasuoki 
Published: August 2012

AbstractThe mechanical isolation hypothesis predicts that physical incompatibility between divergent reproductive morphologies hinders hybridization between populations. However, evidence for this hypothesis remains scarce. We examined this hypothesis using two parapatric carabid beetles,Carabus insulicolaandC.esakii, which are of the subgenusOhomopterusand exhibit a species‐specific genital lock‐and‐key system. Our interspecific crossing experiment revealed that incompatibility of genital morphologies served as a strong postmating‐prezygotic isolation barrier. This isolation was asymmetric: a decrease in female fitness was more costly in the cross with greater genitalic incompatibility between aC.esakiifemale and aC.insulicolamale. These two species share a limited sympatric area, but the mechanism responsible for their coexistence is unclear given no evidence of premating isolation via male mate choice. A comparison of the present results with those of previous studies that quantified reproductive isolation betweenOhomopterusspecies suggest that strong mechanical isolation via genitalic incompatibility plays a major role in species isolation, but that it may be less important in species coexistence.
Biotransformation of benzonitrile herbicides via the nitrile hydratase–amidase pathway in rhodococci
Authors: Veselá Alicja B , Pelantová Helena , Šulc Miroslav , Macková Martina , Lovecká Petra , Thimová Markéta , Pasquarelli Fabrizia , Pičmanová Martina , Pátek Miroslav , Bhalla Tek Chand , Martínková Ludmila 
Published: August 2012

Abstract
The aim of this work was to determine the ability of rhodococci to transform 3,5-dichloro-4-hydroxybenzonitrile (chloroxynil), 3,5-dibromo-4-hydroxybenzonitrile (bromoxynil), 3,5-diiodo-4-hydroxybenzonitrile (ioxynil) and 2,6-dichlorobenzonitrile (dichlobenil); to identify the products and determine their acute toxicities. Rhodococcus erythropolis A4 and Rhodococcus rhodochrous PA-34 converted benzonitrile herbicides into amides, but only the former strain was able to hydrolyze 2,6-dichlorobenzamide into 2,6-dichlorobenzoic acid, and produced also more of the carboxylic acids from the other herbicides compared to strain PA-34. Transformation of nitriles into amides decreased acute toxicities for chloroxynil and dichlobenil, but increased them for bromoxynil and ioxynil. The amides inhibited root growth in Lactuca sativa less than the nitriles but more than the acids. The conversion of the nitrile group may be the first step in the mineralization of benzonitrile herbicides but cannot be itself considered to be a detoxification.
Synthesis and Characterization of Novel n‐9 Fatty Acid Conjugates Possessing Antineoplastic Properties
Authors: Khan Azmat A. , Husain Ahmad , Jabeen Mumtaz , Mustafa Jamal , Owais Mohammad 
Published: August 2012

AbstractThe present study enumerates the synthesis, spectroscopic characterization, and evaluation of anticancer potential of esters of two n‐9 fatty acids viz., oleic acid (OLA) and ricinoleic acid (RCA) with 2,4‐ or 2,6‐diisopropylphenol. The synthesis strategy involved esterification of the hydroxyl group of diisopropylphenol (propofol) to the terminal carboxyl group of n‐9 fatty acid. The synthesized propofol‐n‐9 conjugates having greater lipophilic character were tested initially for cytotoxicity in‐vitro. The conjugates showed specific growth inhibition of cancer cell lines whereas no effect was observed in normal cells. In general, pronounced growth inhibition was found against the human skin malignant melanoma cell line (SK‐MEL‐1). The anticancer potential was also determined by testing the effect of these conjugates on cell migration, cell adhesion and induction of apoptosis in SK‐MEL‐1 cancer cells. Propofol‐OLA conjugates significantly induced apoptosis in contrast to propofol‐RCA conjugates which showed only weak signals for cytochrome c. Conclusively, the synthesized novel ester conjugates showed considerable moderation of anti‐tumor activity. This preliminary study places in‐house synthesized conjugates into the new class of anticancer agents that possess selectivity toward cancer cells over normal cells.
Fatty Acid Composition and Some Physicochemical Properties of Oils from Allanblackia gabonensis and A.stanerana Kernels
Authors: Pengou Martin , Noumi Guy Bertrand , Ngameni Emmanuel 
Published: August 2012

AbstractThe physicochemical properties and chemical composition of oils extracted from two varieties of mature seeds of Allanblackia gabonensis and A.stanerana were assessed. The physicochemical properties of oils from Allanblackia gabonensis and A. stanerana were respectively 5.35 and 22.023 % for the water content; 68.15 and 69.87 % for the extraction yield on a dry basis; 0.35 and 0.30 mg KOH/g oil for the acid index; 35.57 and 29.75 g of I2/100 g oil for the iodine index; 1.3740 and 1.4150 for the refractive index. The fatty acid profile of those oils showed respectively four saturated fatty acids 60.61 and 70.94 %, two monounsaturated fatty acids 37.46 and 28.22 %, two polyunsaturated fatty acids 0.82 and 0.81 % for Allanblackia gabonensis and A. stanerana oils respectively. In both cases, fatty acids C18:0 and C18:1 were dominant. Most of the physicochemical properties showed significant variation (P < 0.05) from one oil to other, the difference being insignificant (P > 0.05) between the two chemical compositions. The analysis of these characteristics showed interesting application features for these oils.
A comparison of vital registration and reproductive‐age mortality survey in Bukidnon, Philippines, 2008
Authors: Garces Roston G. , Sobel Howard L. , Pabellon Joy A.L. , Lopez Juan M. , de Quiroz Castro Maricel , Nyunt‐U Soe 
Published: August 2012

AbstractObjectiveTo determine the accuracy of reported maternal deaths for 2008 in a province in the Philippines.MethodsA reproductive‐age mortality survey (RAMOS) was conducted to identify deaths of women aged 15–49 years from Bukidnon, Philippines, in 2008. Sources included various health and community reporting units. Verbal autopsies were carried out to ascertain maternal deaths.ResultsThe survey found 58 pregnancy‐related deaths in 2008, of which 52 were maternal deaths. Of the 52, 14 were found in local civil registries but 4 were not classified as maternal deaths. No single reporting unit identified all deaths. Local civil registries provided an estimated maternal mortality ratio (MMR) of 49 per 100 000 live births. The present RAMOS estimated an MMR of 209 (95% confidence interval, 191–226) per 100 000 live births.ConclusionOfficial reports led people using the data to believe that the MMR in the province was on track for Millennium Development Goal 5 (to reduce MMR by three‐quarters by 2015). The present survey showed that local civil registries missed three‐quarters of all maternal deaths. All countries engaged in addressing maternal mortality reduction should consider similar approaches to improve data quality.
Experiences of women undergoing colposcopy in southeastern Nigeria
Authors: Chigbu Chibuike O. , Aniebue Uzochukwu U. 
Published: August 2012

AbstractObjectiveTo evaluate the experiences, preferences, and needs of women undergoing colposcopy in southeastern Nigeria.MethodsWomen undergoing colposcopy at 2 centers in southeastern Nigeria between August 1, 2009, and October 31, 2011, were interviewed using structured interviewer‐administered questionnaires.ResultsIn total, 409 women were interviewed. The majority (60.8%) of these women were satisfied with the overall process of colposcopy. Invasion of privacy and re‐assuring attitude of attending clinic personnel were reported as the most dissatisfying and most satisfying aspects of colposcopy, respectively. Privacy during the procedure and written take‐home information were the most frequently reported needs. Most participants preferred a female colposcopist and the presence of their spouse during colposcopic examination.ConclusionSoutheastern Nigerian women are less satisfied with the overall process of colposcopy than their counterparts from high‐income settings. The majority of the women interviewed would have an improved colposcopic experience if their privacy concerns and information needs were addressed and their spouses allowed into the examination room. The findings from the present study should encourage existing and emerging colposcopy service providers in low‐resource settings to improve both service delivery and their patients' overall colposcopic experience.
A Turkish Gynecologic Oncology Group study of fertility‐sparing treatment for early‐stage endometrial cancer
Authors: Dursun Polat , Erkanli Serkan , Güzel Ahmet Bariş , Gultekin Murat , Tarhan Nefise Cagla , Altundag Ozden , Demirkiran Fuat , Beşe Tugan , Yildirim Yusuf , Bozdag Gurkan , Yarali Hakan , Simsek Tayyup , Ozcelik Bulent , Ortaç Firat , Taskin Salih , Guvenal Tevfik , Ozgul Nejat , Haberal Ali , Vardar M. Ali , Dede Murat , Yenen Mufit , Altintas Aytekin , Arvas Macit , Ayhan Ali 
Published: August 2012

AbstractObjectiveTo analyze the results of fertility‐sparing treatment of early‐stage endometrial cancer (EC) in patients treated at Turkish gynecologic oncology centers, and to present a review of the literature.MethodsThirteen healthcare centers in Turkey were contacted to determine if they were eligible to participate in the study. Centers that were eligible and agreed to participate were sent a database form to record the demographic characteristics, clinicopathologic findings, and follow‐up results for their EC patients.ResultsEleven Turkish healthcare centers provided data on 43 EC patients. Mean duration of treatment was 5 months and mean follow‐up was 49 months. In total, 35 (81.4%) patients were tumor free following primary progesterone therapy. Mean time from the end of progesterone therapy to pregnancy was 10.6 ± 4.3 months (range, 3–18 months). Two patients had tumor recurrence during follow‐up. The pregnancy rate among the 31 women who actively sought pregnancy was 41.9% (n = 13).ConclusionConservative management of early‐stage EC in women of reproductive age using oral progestins was effective and did not compromise oncological outcome. Pregnancy in the study patients was achieved spontaneously and artificially.
The role of Purkinje fibers in the emergence of an incessant form of polymorphic ventricular tachycardia or ventricular fibrillation associated with ischemic heart disease
Authors: Kobayashi Yoshinori , Iwasaki Yu‐ki , Miyauchi Yasushi , Hayashi Meiso , Ohno Norihiko , Yodogawa Kenji , Morita Norishige , Tanaka Keiji , Mizuno Kyouichi 
Published: August 2012

AbstractBackground: The clinical and electrophysiological characteristic of ventricular premature contractions (VPCs) which trigger the incessant form of polymorphic ventricular tachycardia (VT), so‐called “electrical storm” associated with ischemic heart disease, remains unclarified. The aim of this study was to evaluate those matters and the possible role of the Purkinje network in the emergence of an electrical storm.Methods and results: We experienced 5 patients (68 ± 5 years, mean LVEF: 29%) with electrical storms which occurred during the acute phase of an infarction in 3 patients and the remote phase in 2. The triggering VPCs were multifocal in 3 patients and monofocal in the remaining 2. Radiofrequency (RF) catheter ablation was performed for a goal of eliminating the triggering VPCs. A total of 9 different kinds of VPCs differentiated by their morphology were successfully eliminated by the RF deliveries targeting the VPCs’ foci. At the successful ablation sites, Purkinje potentials preceded the QRS onset of the VPC by 67 ± 23 ms, suggesting the VPCs originated in the surviving Purkinje fibers. Moreover, the extensive RF deliveries applied at the surviving Purkinje network rendered the polymorphic VT unable to be induced by programmed stimulation which reproducibly induced it before the ablation in 2 patients.Conclusion: A surviving Purkinje network might contribute not only to the initiation of the repetitive form of lethal ventricular arrhythmias, but also to the perpetuation of the arrhythmias in patients with ischemic heart disease.
Adenosine‐Sensitive Focal Reentrant Atrial Tachycardia Originating From the Mitral Annulus‐Aorta Junction
Authors: Morishima Itsuro , Sone Takahito , Tsuboi Hideyuki , Mukawa Hiroaki , Uesugi Michitaka 
Published: August 2012

AbstractAdenosine‐sensitive reentrant atrial tachycardia (AT) has been recognized to originate from the confined area of either the right or left atiroventricular nodal regions. We describe a case with adenosine‐sensitive focal AT which was successfully ablated at the uncommon focus located at the mitral annulus‐aorta junction. The mode of AT initiation during the atrial extrastimulus suggested as the mechanism tachycardia reentry; AT was terminated by a bolus of 2 mg of adenosine 5’‐triphosphate. These electrophysiological features are possibly associated with a substrate involved in the mitral annulus‐aorta junction with node‐like properties that is responsive to adenosine.
Two Cases of Pilsicainide Intoxication showing the Brugada‐type Electrocardiographic Findings and Incessant Wide QRS Tachycardia
Authors: Sumiyoshi Masataka , Hayashi Hidemori , Ichinose Tetsuo , Itoh Seigo , Kawamura Masaki , Suwa Satoru , Sakurai Hidehiko 
Published: August 2012

AbstractWe have experienced two patients with the Brugada‐type electrocardiographic abnormalities and incessant wide QRS tachycardia (presumed ventricular tachycardia) induced by intoxication of a class IC antiarrhythmic drug pilsicainide. They were elderly men with impaired renal function. Plasma concentration of pilsicainide was elevated to a toxic level in both patients. After cessation of pilsicainide, incessant wide QRS tachycardia spontaneously subsided and intraventricular conduction delay with coved type ST segment elevation in V1 and V2 disappeared. In the elderly or patients with renal dysfunction, we should be very careful regarding dose adjustment of pilsicainide or it may be better to avoid using this drug.
Cardiac Pacing Suppressed Macroscopic T Wave Alternans in a Patient with Heart Failure Caused by Non‐ischemic Cardiomyopathy
Authors: Miyaji Kotaro , Abe Keisuke , Abe Koji , Kondo Naomichi , Suzuki Hiroki , Kodera Satoshi , Sato Kazutoshi , Kushida Shunichi , Kanda Junji , Suzuki Makoto , Nishizaki Mitsuhiro 
Published: August 2012

AbstractA 67‐year‐old male with dilated cardiomyopathy and chronic renal failure who received chronic hemodialysis for 9 years admitted with pulmonary edema. Three days after admission, electrocardiogram showed transient prolongation of QT interval which was followed by macroscopic T wave alternans (TWA) and ventricular fibrillation (VF). Temporary pacing from right ventricular apex suppressed TWA and VF effectively. Combined cardiac resynchronization therapy and implantable cardioverter defibrillator device was implanted for the secondary prevention of VF. Both prolongation of QT interval and TWA disappeared for 10 days after therapy and no arrhythmic event occurred since then.