bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organic Stereochemistry. Part 1. Symmetry Elements and Operations, Classification of Stereoisomers
Authors: Testa Bernard , Vistoli Giulio , Pedretti Alessandro 
Published: January 2013

AbstractThis review initiates a general presentation of the principles of stereochemistry with special reference to medicinal compounds. The format is essentially identical with that of a previous Series of seven reviews on the Metabolism of Drugs and Other Xenobiotics published between October 2006 and October 2009 by B. T. and Stefanie Krämer in Chemistry & Biodiversity. Here, there will be eight reviews published in Helvetica Chimica Acta, to be grouped and published in book form together with some additional material. Part 1 introduces this new series by presenting and illustrating basic concepts on which the edifice of stereochemistry is built. At the most basic level of such foundations, we find symmetry as presented here in terms of its elements, operations, and point groups. This is followed by a classification of isomeric molecular structures, as well as a classification of steric relationships between molecular fragments.
ANALYSING THE GENDER GAP IN EDUCATION ATTAINMENT: A SIMPLE FRAMEWORK WITH APPLICATION TO GHANA
Authors: Nguyen Minh Cong , Wodon Quentin 
Published: January 2013

AbstractA simple decomposition is provided to analyse the gender gap in educational attainment with an application to Ghana. The decomposition considers six conditional steps required for completing high school, namely starting and completing primary school, starting and completing junior high school, and starting and completing senior high school. Using household surveys parameters are estimated conditionally on having completed the previous step. By estimating the decomposition over time and comparing parameters between groups, we are able to assess whether the gender gap is being reduced over time and where dropping out takes place in the education system for various groups. Copyright © 2013 John Wiley & Sons, Ltd.
Subtype CRF01_AE dominate the sexually transmitted human immunodeficiency virus type 1 epidemic in Guangxi, China
Authors: Li Lin , Chen Lili , Liang Shujia , Liu Wei , Li Tianyi , Liu Yongjian , Li Hanping , Bao Zuoyi , Wang Xiaolin , Li Jingyun 
Published: January 2013

AbstractHuman immunodeficiency virus type 1 (HIV‐1) infection by sexual transmission in Guangxi, China had increased dramatically. However, limited information is available on the genetic characterization of the HIV‐1 epidemic. In this study, HIV‐1 seropositive drug‐naïve patients infected by heterosexual transmission were enrolled. The full length gag and pol genes were sequenced followed by phylogenetic analysis, recombinant analysis and drug resistant analysis. Multiple subtypes were identified, including CRF01_AE (80.1%), CRF07_BC (6.4%), CRF08_BC (10.2%), subtype B (1.7%), and URFs (1.7%). In the phylogenetic tree, two large CRF01_AE clusters were identified. One cluster is originating from Vietnam strains as being reported previously in intravenous drug users. One novel cluster was identified and showed close relationship to strains from Fujian province. Inter‐subtype recombination among CRF01_AE, subtype B and C was identified. Low level drug‐resistance in drug‐naïve heterosexually transmitted infections was found. The results suggested that multiple originating CRF01_AE strains dominated the HIV‐1 epidemic in heterosexual transmission in Guangxi province. J. Med. Virol. 85:388–395, 2013. © 2013 Wiley Periodicals, Inc.
Environmental surveillance of enterovirus in Northern India using an integrated shell vial culture with a semi‐nested RT PCR and partial sequencing of the VP1 gene
Authors: Shukla Deepti , Kumar Arvind , Srivastava Shalini , Idris Mohammad Z. , Dhole Tapan N. 
Published: January 2013

AbstractEnteroviruses have been reported in epidemic form during last 10 years in northern India. Environmental surveillance of sewage is the method of choice in limited resources countries for detection of enterovirus serotypes circulating in the community. Twenty‐four sewage samples collected between January, 2009 and December, 2010 were tested for enterovirus by using a new modified integrated shell vial culture (ISVC) with a semi‐nested RT‐PCR of a partial VP1 gene and virus isolation integrated with semi‐nested RT‐PCR of a partial VP1 gene. Twenty‐one (87.5%) out of 24 samples were positive for enterovirus by the conventional method and all samples (100%) by the ISVC–RT‐PCR. The additional positive samples detected by ISVC–RT‐PCR was typed as six different enterovirus serotypes (Sabin poliovirus 3, Coxsackievirus B3, Coxsackievirus A13, Coxsackievirus A17, Echovirus 33, and Enterovirus 75). Phylogenetic analysis of a partial VP1 gene of Echovirus 19 showed that one genetic lineage clustered with isolates from Georgia suggesting their importation into northern India. Detection of wild poliovirus in the absence of clinical cases with 16 different co‐circulating enterovirus serotypes supports the need of increased molecular surveillance of sewage. Rapid identification and characterization of enterovirus serotypes is necessary to study their transmission and evolution in different geographical regions to prevent future outbreak. J. Med. Virol. 85:505–511, 2013. © 2013 Wiley Periodicals, Inc.
The two faces of high self‐monitors: Chameleonic moderating effects of self‐monitoring on the relationships between personality traits and counterproductive work behaviors
Authors: Oh In‐Sue , Charlier Steven D. , Mount Michael K. , Berry Christopher M. 
Published: January 2013

SummaryThis study examines whether and how self‐monitoring moderates the relationships between two personality traits (agreeableness and conscientiousness) and counterproductive work behavior directed toward the organization (CWB‐O) and toward other employees (CWB‐I). High self‐monitors strive to attain personal goals related to status and prestige enhancement by adjusting their behavior to what the situation requires or allows for. We propose that the status enhancement motive can take on two different yet related forms—impression management (interpersonal potency) and opportunism (win‐at‐all‐costs)—depending on relevant situational cues. We hypothesize that in public, interpersonal settings where their behavior is visible to others, high self‐monitors' desire to enhance their status by looking good to others suppresses the natural expression of low agreeableness via increased engagement in CWB‐I. Conversely, we hypothesize that in private, non‐interpersonal settings where their behavior is rarely visible to others, high self‐monitors' desire to enhance their status by doing whatever it takes to get what they want intensifies the natural expression of low conscientiousness via increased engagement in CWB‐O. On the basis of two independent samples of participants, results of moderated multiple regression analyses provided support for the hypotheses. Copyright © 2013 John Wiley & Sons, Ltd.
Kinetic Studies of Substitution Reactions of Uranyl(VI) Schiff Base Complexes with Tributylphosphine
Authors: Asadi Zahra , Shorkaei Mohammad Ranjkesh 
Published: January 2013

AbstractThe kinetics of the substitution reaction of uranyl Schiff base complexes with tributylphosphine was studied spectrophotometrically in acetonitrile. Uranyl complexes have a pentagonal bipyramidal structure with a trans‐UO2 moiety at the axial positions. In uranyl tetradentate Schiff base complexes, the fifth position of the equatorial plane is occupied by the solvent molecule, which weakly coordinates to the U center. In a substitution reaction, tributylphosphine can easily replace the solvent molecule. By considering the excellent linearity of kobs versus the molar concentration of tributylphosphine, the large negative values of Δ S#, and the small values of Δ H#, an associative (A) mechanism has been suggested. By comparing the rate constants (k2) and the activation parameters, it is obvious that two parameters are effective in the rate of substitution reactions; The first parameter is the steric effect that the rate of reaction has been decreased by increasing this factor, and the other parameter is the electronic property that the electron‐withdrawing group leads to increase the rate of reaction and the electron donor group decreases it. © 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 168–174, 2013
Macromol. Biosci. 1/2013
Authors: Mandal Biman B. , Gil Eun Seok , Panilaitis Bruce , Kaplan David L. 
Published: January 2013

AbstractFront Cover: Highly aligned 3D silk scaffolds using directional freezing in a custom designed chamber was demonstrated. The method is versatile and holds potential to produce complex, multicomponent aligned structures for various tissue engineering and biomedical applications, needing immediate cell alignment to mimic native tissue hierarchy and function. Further details can be found in the article by B. B. Mandal, E. S. Gil, B. Panilaitis, and D. L. Kaplan* on page 48.magnified image
Redox Intitiated Cationic Polymerization
Authors: Crivello James V. 
Published: January 2013

AbstractTwo novel redox initiator systems have been developed for carrying out the cationic polymerizations of vinyl and heterocyclic monomers. The initiators are based on various onium salts as the oxidant together with an alkylborane or an organosilane as the reducing agent. Using both redox cationic initiator systems, the polymerizations of a wide variety of monomers can be carried out at or below room temperature in the presence or absence of unreactive solvents. Also described in this communication is the novel use of a two‐component redox system in which the reducing agent, a silane, is delivered to the monomer sample in the vapor state. Optical pyrometry (infrared thermography) was employed as a convenient method with which to monitor the polymerizations in real‐time. A study of the effects of variations in the structures of the onium salt, the silane and the type of noble metal catalyst were carried out. The use of these initiator systems for carrying out commercially attractive crosslinking polymerizations for coatings, composites and electronic encapsulations is discussed.
Polyisobutylene Based Supramolecular Networks via Living Carbocationic Polymerization
Authors: Hackethal Katharina , Binder Wolfgang H. 
Published: January 2013

AbstractFunctionalized, styrene based monomers were investigated for copolymerization with isobutylene (IB) via living carbocationic polymerization. The achieved incorporation of polar moieties into the polymer backbone yielded supramolecular networks, which were analyzed and characterized via rheological measurements.
Anionic Polymerization Behavior of α‐Methylene‐N‐methylpyrrolidone
Authors: Ishizone Takashi , Kitazawa Keita , Suzuki Takashi , Kawauchi Susumu 
Published: January 2013

AbstractAnionic polymerization of α‐methylene‐N‐methylpyrrolidone (MMP) was carried out in THF at −78∼0 °C with diphenylmethylpotassium (Ph2CHK) and with diphenylmethyllithium (Ph2CHLi) in the presence of Lewis acidic diethylzinc (Et2Zn). Poly(MMP)s possessing predicted molecular weights based on the molar ratios between monomer and initiators and narrow molecular weight distributions (Mw/Mn < 1.1) were obtained in quantitative yields. It was demonstrated that the propagating chain end of poly(MMP) was stable at −30 °C to form the polymers with well‐defined chain structures. From the polymerizations at the various temperatures ranging from −50 to −30 °C, the apparent rate constant and the activation energy of the polymerization were estimated as follows: ln k = −6.93 × 103/T + 25.7 and 57 ± 5 kJ mol−1, respectively.
Synthesis and Characterization of Poly(N‐isopropylacrylamide) and Poly(vinyl acetate) Diblock Copolymers via MADIX Process
Authors: Özgüç Çimen , Helvacıoğlu Ekmel , Nugay Nihan , Nugay Turgut 
Published: January 2013

AbstractThe synthesis of diblock copolymers of poly(N‐isopropylacrylamide) (PNIPAM) and poly(vinyl acetate) (PVAc) was performed by macromolecular design via interchange of xanthates (MADIX) process. Following the preparation of methyl (isopropoxycarbonothioyl) sulfanyl acetate (MIPCTSA) as chain transfer agent, it was reacted with vinyl acetate to obtain PVAc macro‐chain transfer agent. Then, block copolymerization was completed by successive addition of N‐isopropylacrylamide (NIPAM). 1H NMR spectroscopy confirmed the presence of both blocks in the copolymer structure, with the expected composition based on the feed ratio. Size Exclusion Chromatography (SEC) was used to investigate the relative values of molecular characteristics. Only 20% of PVAc was converted to block copolymer. The resultant block copolymer structures were further examined in terms of their morphologies as well as critical micelle concentration (CMC) by using ESEM and Fluorescence Excitation Spectroscopic techniques, respectively. Morphological characterization confirmed amphiphilic block copolymer formation with the existence of mainly ca. 100 nm well distributed micelles. The thermo responsive amphiphilic behavior of the block copolymer solutions were followed by Dynamic Light Scattering (DLS) technique.
In Situ Quenching Methods Toward exo‐Olefin‐Terminated Polyisobutylene
Authors: Ummadisetty Subramanyam , Morgan David L. , Stokes Casey D. , Harrison J.J. , Campbell Christopher G. , Storey Robson F. 
Published: January 2013

Abstractexo‐Olefin‐terminated polyisobutylene was obtained directly from living isobutylene polymerizations by addition of a quenching compound to the living chain ends. Three broad classes of compounds were evaluated including hindered bases such as hindered pyridines and piperidines, N‐hydro‐2,5‐disubstitutedpyrroles, and sulfides, ethers, and silylethers. The proposed mechanism of quenching unique to each class was discussed, with supporting kinetic, spectroscopic, and structure‐based evidence presented. Hindered bases were proposed to operate by E2 elimination reaction of free base at the carbenium ion. N‐Hydro‐2,5‐disubstitutedpyrroles were proposed to form the η5‐2,5‐disubstitutedpyrrolyltrichloro‐titanium(IV) coordination complex, which serves as the true quencher. Sulfides, ethers, and silylethers were proposed to operate by first converting the PIB chain ends quantitatively to the onium adduct, which is then decomposed to form exo‐olefin PIB. Sulfides and ethers were the best performing quenchers of all the types studied, particularly bulky ones such di‐tert‐butylsulfide and diisopropyl ether.
Investigation on the Friction Sensitivity of a Matchhead Composition Influenced by the Surface Roughness of Contact Materials
Authors: Nalla Mohamed Mohamed Ismail , Sivapirakasam Suthandathan Paramashivan , Surianarayanan Mahadevan 
Published: January 2013

AbstractFire and explosions in the processing of matchhead compositions are reported due to the friction sensitivity of materials used. This investigation is aimed at investigating the influence of different types of contact materials and their surface roughness on the friction sensitivity of a matchhead composition. The friction sensitivity of the matchhead composition was found to be dependent on the contact materials and their roughness. The results demonstrated that the contact materials and their surface roughness imparted variations to the sensitivity, ranging from 108 to 360 N. The sensitivity response of the energetic mixture was quicker in case of aluminum plate‐aluminum pin combinations than those when steel plate‐steel pin and brass plate‐brass pin combinations were used. For the first time, the experimental investigation identified a new value based on the material’s surface roughnesses called critical surface roughness, at which the matchhead composition ignited at a minimum frictional load. The matchhead composition was found to be highly hazardous at the critical surface roughness values of 1.09, 1.01, and 1.05 μm for aluminum, brass, and steel surfaces, respectively. Based on the experimental results this paper also discusses mechanism of ignition caused by the frictional load.
Experimental Research on Cohesion and Internal Friction Angle of the Double‐base Propellant
Authors: Zhang Jianbin , Ju Yutao , Zhou Changsheng 
Published: January 2013

AbstractA conventional triaxial confining pressure test was designed to suit the working environment of propellant grain. The mechanical properties of the double‐base propellant under varied confining pressure conditions were studied and analyzed. The results show that confining pressures have a pronounced influence on the mechanical properties of propellant materials. The yield value and compressive strength of propellant material increase as the confining pressure increases. The propellant material shows great ductility before it is destroyed, the ductility of propellant material increases with an increase in the confining pressure. The yield values and failure values of the propellant materials show linear relationships with the confining pressures. According to the Mohr‐Coulomb theory, the cohesion and internal friction angle of the double‐base propellant material were obtained. The influence factors of cohesion and internal friction angle of the double‐base propellant material are analyzed. The failure process and mechanism of propellant materials under varying confining pressures were studied. These projects have contributed to the understanding of the innate character of propellant materials and explain the damage and destruction of the structures and components. With this information, measures can be taken to improve the quality and structural performance of propellant grain. The information collected herein may lay the foundation for yield criteria and viscoelastic‐plastic constitutive model of propellant materials.
The use of spin desalting columns in DMSO‐quenched H/D‐exchange NMR experiments
Authors: Chandak Mahesh S. , Nakamura Takashi , Takenaka Toshio , Chaudhuri Tapan K. , Yagi‐Utsumi Maho , Chen Jin , Kato Koichi , Kuwajima Kunihiro 
Published: January 2013

AbstractDimethylsulfoxide (DMSO)‐quenched hydrogen/deuterium (H/D)‐exchange is a powerful method to characterize the H/D‐exchange behaviors of proteins and protein assemblies, and it is potentially useful for investigating non‐protected fast‐exchanging amide protons in the unfolded state. However, the method has not been used for studies on fully unfolded proteins in a concentrated denaturant or protein solutions at high salt concentrations. In all of the current DMSO‐quenched H/D‐exchange studies of proteins so far reported, lyophilization was used to remove D2O from the protein solution, and the lyophilized protein was dissolved in the DMSO solution to quench the H/D exchange reactions and to measure the amide proton signals by two‐dimensional nuclear magnetic resonance (2D NMR) spectra. The denaturants or salts remaining after lyophilization thus prevent the measurement of good NMR spectra. In this article, we report that the use of spin desalting columns is a very effective alternative to lyophilization for the medium exchange from the D2O buffer to the DMSO solution. We show that the medium exchange by a spin desalting column takes only about 10 min in contrast to an overnight length of time required for lyophilization, and that the use of spin desalting columns has made it possible to monitor the H/D‐exchange behavior of a fully unfolded protein in a concentrated denaturant. We report the results of unfolded ubiquitin in 6.0M guanidinium chloride.
Ethno‐Economic Satellite: the Case of Korean Residential Clusters in Auckland
Authors: Hong Seong‐Yun , Yoon Hong‐key 
Published: January 2013

ABSTRACTRecent studies on the residential patterns of Asian immigrants in Pacific Rim countries have revealed a new form of suburban ethnic settlements – ethnoburbs. The geographic distribution of Koreans in Auckland indicates that an ethnoburb‐like concentration has been developed in this small but rapidly increasing population group: Koreans are residentially clustered but not isolated from other population groups in an absolute sense. Interestingly, however, the economic structure of this ethnic community is somewhat different from that of ethnoburbs observed in North American cities. Statistical analysis of ethnic‐specific business directories demonstrates that the economic structure within the Korean residential clusters in Auckland is dependent on the state of their home country's economy. In this regard, Korean businesses are more like economic satellites rather than independent economic entities in the transnational market, as observed in other suburban ethnic settlements. The residential clustering of Koreans in Auckland is an important example of how suburban ethnic settlements can vary in terms of their economic structures. Copyright © 2013 John Wiley & Sons, Ltd.
Migrants' Remittances, Poverty and Social Protection in the South Pacific: Fiji and Tonga
Authors: Brown Richard P. C. , Connell John , Jimenez‐Soto Eliana V. 
Published: January 2013

ABSTRACTSmall island states are increasingly characterised by the growing role of international migration and remittances as components of national and household incomes. Recent household‐level survey data on migration and remittances in two Pacific island states, Fiji and Tonga, demonstrate that where formal social protection systems are largely absent, migration and remittances can perform a similar function informally, contributing significantly to development objectives. Remittances also have a positive effect on poverty alleviation and wealth creation, although the impacts on income distribution are mixed. From a policy perspective, these informal social protection and poverty alleviation mechanisms may be more effective in promoting development than policies designed to incorporate remittances into the formal financial systems. Migration and remittances play an increasingly valuable role in small states where domestic development opportunities are limited. Copyright © 2013 John Wiley & Sons, Ltd.
Gain characteristic of dilute nitride HELLISH‐VCSOA for 1.3 µm wavelength operation
Authors: Chaqmaqche F. A. I. , Mazzucato S. , Balkan N. , Hugues M. , Hopkinson M. 
Published: January 2013

AbstractOptical amplification of more than 3 dB is demonstrated using the Hot Electron Light Emitting and Lasing Semiconductor Heterostructure device in a Vertical Cavity Semiconductor Optical Amplifier configuration (HELLISH‐VCSOA). The device consists of dilute nitride quantum wells Ga0.35In0.65N0.02As0.08/GaAs multiple quantum well (MQW) layers placed in the active region between the doped GaAs claddings and undoped GaAs/AlAs DBRs. Compared to standard VCSOAs in the HELLISH device, the current here does not flow across the distributed Bragg reflectors (DBR) but is injected longitudinally into the p‐ and n‐doped cladding layers. Therefore DBR layers can be undoped, and heating problems en countered in conventional VCSOAs can be avoided. Current‐voltage and spectral characteristics are measured at room temperature under different optical and electrical excitation conditions to demonstrate the possibility of employing this device for amplification purposes (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)