bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combined Rhodium/Gold Catalysis: From Propargyloxiranes to 2,5‐Dihydrofurans in One Pot
Authors: Aksın‐Artok Özge , Krause Norbert 
Published: February 2011

AbstractA new and efficient one‐pot synthesis of 2,5‐dihydrofurans from propargyloxiranes and arylboronic acids takes advantage of sequential rhodium‐gold catalysis. The transformation proceeds with center‐to‐axis‐to‐center chirality transfer and tolerates a wide variety of electron‐accepting or electron‐withdrawing substituents at the arylboronic acid, as well as cyclic or acyclic propargyloxiranes.
Studies on the release of ibuprofen from Al3+ ion cross‐linked homopolymeric and interpenetrating network hydrogel beads of carboxymethyl xanthan and sodium alginate
Authors: Ray Rajat , Maity Siddhartha , Mandal Sanchita , Chatterjee Tapan Kumar , Sa Biswanath 
Published: February 2011

AbstractHomopolymeric and interpenetrating network (IPN) hydrogel beads of ibuprofen (IBP), a nonsteroidal anti‐inflammatory drug, were prepared using carboxymethyl xanthan and sodium alginate as polymers and AlCl3 as a cross‐linking agent. Formation of IPN structure was examined using FTIR analysis. The effect of composition of the hydrogel beads and the amount drug load on the release of IBP was studied in acidic and phosphate buffer (PB) solution of pH 6.8. In accordance with the swelling behavior of the beads, drug release from the IPN beads in acidic solution was found to be confined within those from homopolymeric beads. On the other hand, drug release from IPN beads in PB solution was found to be less than those from the homopolymeric beads although the swelling of the beads followed the same trend as in an acidic solution. An increase in the drug load further decreased the drug release from all the beads in both the dissolution media. FTIR, XRD, and DSC analyses demonstrated the absence of any interaction between the drug and the polymers. The results indicated that IPN hydrogel beads provided more sustained release of IBP than homopolymeric beads. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30:1–11, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20199
Solvent effects on the thermal and mechanical properties of poly(methyl methacrylate) casted from concentrated solutions
Authors: Patra Niranjan , Barone Alberto C. , Salerno Marco 
Published: February 2011

AbstractThe thermal, mechanical, and structural properties of poly(methyl methacrylate) (PMMA) samples casted from solutions of chloroform, toluene, and N,N‐dimethylformamide (DMF) were investigated by means of differential scanning calorimetry, nanoindentation, and Fourier transform infrared spectroscopy, respectively. The thermal analysis showed that for PMMA prepared from chloroform and toluene solutions the glass transition temperature was quite lower than for bulk PMMA, whereas for PMMA prepared from the DMF solution it was higher. The mechanical analysis showed higher reduced modulus and lower creep effect for PMMA prepared from the DMF solution than for PMMA prepared from the chloroform and toluene solutions. The spectroscopic analysis pointed out the formation of a strong bond between the polymer carbonyl group and the solvent amide group for the PMMA prepared from the DMF solution and a significant distortion of the polymer chain for the PMMA prepared from the chloroform and toluene solutions. Therefore, the observed thermal and mechanical behavior is ascribed to the different hydrogen bonding contributions, the rotation of the end group, and the distortion of the polymer chain. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30:12–20, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20203
Effect of packing pressure on refractive index variation in injection molding of precision plastic optical lens
Authors: Yang Can , Su Lijuan , Huang Chunning , Huang Han‐Xiong , Castro Jose M. , Yi Allen Y. 
Published: February 2011

AbstractIn this study, refractive index variation in injection‐molded polymethylmethacrylate optical lenses under different levels of packing pressure was evaluated using a Shack–Hartmann wavefront sensor‐based metrology system. The experimental results showed that optical polymer's refractive index exhibits a considerable amount of variation for the lenses molded under different packing pressures. Specifically, within the range investigated in this study, refractive index variation is more uniform when higher packing pressure was used but less so for lower packing pressure. Refractive index variation is believed to be the result of density variation, which itself is caused by shrinkage variation at different packing conditions. In addition, using density information in the plastic lenses predicted by finite element simulation, refractive index variation was numerically determined using the differential Lorentz–Lorenz equation and the results were in good agreement with the experiments conducted in this research. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 30:51–61, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20211
Polymer Blend Solar Cells Based on a High‐Mobility Naphthalenediimide‐Based Polymer Acceptor: Device Physics, Photophysics and Morphology
Authors: Moore Jennifer R. , Albert‐Seifried Sebastian , Rao Akshay , Massip Sylvain , Watts Benjamin , Morgan David J. , Friend Richard H. , McNeill Christopher R. , Sirringhaus Henning 
Published: February 2011

AbstractA high electron mobility polymer, poly{[N,N’‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5’‐(2,2’‐bithiophene) (P(NDI2OD‐T2)) is investigated for use as an electron acceptor in all‐polymer blends. Despite the high bulk electron mobility, near‐infrared absorption band and compatible energy levels, bulk heterojunction devices fabricated with poly(3‐hexylthiophene) (P3HT) as the electron donor exhibit power conversion efficiencies of only 0.2%. In order to understand this disappointing photovoltaic performance, systematic investigations of the photophysics, device physics and morphology of this system are performed. Ultra‐fast transient absorption spectroscopy reveals a two‐stage decay process with an initial rapid loss of photoinduced polarons, followed by a second slower decay. This second slower decay is similar to what is observed for efficient P3HT:PCBM ([6,6]‐phenyl C61‐butyric acid methyl ester) blends, however the initial fast decay that is absent in P3HT:PCBM blends suggests rapid, geminate recombination of charge pairs shortly after charge transfer. X‐ray microscopy reveals coarse phase separation of P3HT:P(NDI2OD‐T2) blends with domains of size 0.2 to 1 micrometer. P3HT photoluminescence, however, is still found to be efficiently quenched indicating intermixing within these mesoscale domains. This hierarchy of phase separation is consistent with the transient absorption, whereby localized confinement of charges on isolated chains in the matrix of the other polymer hinders the separation of interfacial electron‐hole pairs. These results indicate that local, interfacial processes are the key factor determining the overall efficiency of this system and highlight the need for improved morphological control in order for the potential benefit of high‐mobility electron accepting polymers to be realized.
Ethnic differences in patterns of occupational exposure in New Zealand
Authors: Eng Amanda , 't Mannetje Andrea , Ellison‐Loschmann Lis , McLean Dave , Cheng Soo , Pearce Neil 
Published: February 2011

AbstractObjectivesTo investigate the differences in occupational exposure between Māori (New Zealand's indigenous people) and non‐Māori.MethodsParticipants were randomly selected from the Electoral Roll. Exposure to occupational risk factors was assessed through telephone interviews and exposure prevalences of Māori (n = 273) and non‐Māori (n = 2,724) were compared. Subsequently, Māori were matched with non‐Māori on current occupation (n = 482) to assess whether ethnic differences also exist within occupations.ResultsMāori were more likely to report exposure to physical strain (e.g., lifting, standing). Part of these differences remained when Māori were compared with non‐Māori in the same job. In addition, Māori women were twice as likely to categorize their job as very or extremely stressful than non‐Māori women in the same job, while Māori men were twice as likely to report exposure to dust.ConclusionMarked ethnic differences exist in risk factors for occupational ill‐health, due to both occupational distribution and the distribution of tasks within occupations. Am. J. Ind. Med. 54:410–418, 2011. © 2011 Wiley‐Liss, Inc.
Cancer incidence and mortality among workers exposed to benzidine
Authors: Brown Shannon Cameron , Alberts Risa , Schoenberg Mark 
Published: February 2011

AbstractBackgroundA historical cohort study was conducted among 997 individuals employed at a chemical production facility to investigate whether occupational exposures to benzidine and other arylamines were associated with the increased risk of cancer.MethodsCancers were identified from cancer registries, death certificates, and medical records. Exposures were evaluated using a job‐exposure matrix. Workers were categorized into exposure groups to calculate cancer‐specific standardized incidence ratios (SIRs) and perform survival analyses.ResultsSIRs for cancer of the bladder (SIR = 3.5; CI 1.7, 6.4), small intestine (SIR 18.4; CI 2.2, 66.4), and soft tissue including heart (SIR = 11.9; CI 1.4, 42.8) were elevated among workers with the highest exposures and risk increased with increasing exposures. SIRs for several additional cancers were also elevated.ConclusionOur results support previous findings of increased risk of bladder cancer among individuals exposed to benzidine and other arylamines. Workers may also have been at increased risk for cancers other than cancer of the bladder. Am. J. Ind. Med. 54:300–306, 2011. © 2011 Wiley‐Liss, Inc.
Assessing occupational health and safety of young workers who use youth employment centers
Authors: Breslin F. Curtis , Morassaei Sara , Wood Matt , Mustard Cameron A. 
Published: February 2011

AbstractBackgroundAdolescents and young adults who are out of school are at elevated risk for a work injury.MethodsTo obtain more information on this “high risk” group of young workers, young people at youth employment centers across Ontario were asked through an online survey about training, unsafe work conditions, work injuries and safety knowledge.ResultsThe 1,886 youth who completed the survey reported a medically attended work injury rate of 14.45 per 100 FTEs. Also, the most common unsafe work conditions were dust/particles, trip hazards and heavy lifting. In addition, many young workers reported using much of their income for living essentials (e.g., rent).ConclusionsThough not a representative sample, it appears that youth using employment centers experience many unsafe work conditions and work injuries. While many report safety training, the nature and effectiveness of this training remains to be determined. The large portion of young workers out of school and working for living essentials included in this sample suggest that youth employment centers should be considered in future prevention efforts targeting this vulnerable subgroup of workers. Am. J. Ind. Med. 54:325–337, 2011. © 2011 Wiley‐Liss, Inc.
Understanding emotions in primates: in honor of Darwin's 200th birthday
Authors: Fragaszy Dorothy , Simpson Elizabeth 
Published: February 2011

AbstractIn the bicentenary year of Darwin's birth, the American Society of Primatologists honored his memory by convening a symposium entitled “Understanding emotions in primates: In honor of Darwin's 200th birthday.” The four articles in this special section, excepting this introduction, derive from that symposium. The section confirms that the topic of emotion is once again, as in Darwin's lifetime, the subject of wide‐ranging, theoretically exciting research, and that studies with nonhuman primates are at the leading edge of a rapidly changing field. Am. J. Primatol. 73:503–506, 2011. © 2011 Wiley‐Liss, Inc.
From Conventional to Unusual Enzyme Inhibitor Scaffolds: The Quest for Target Specificity
Authors: Meggers Eric 
Published: February 2011

AbstractThe tremendous challenge presented by the specific molecular recognition of single biomacromolecular targets within complex biological systems demands novel and creative design strategies. This Minireview discusses some conventional and unusual approaches for the design of target‐selective enzyme inhibitors with a focus on the underlying chemical scaffolds. These include complicated natural‐product‐like organic molecules, stable octahedral metal complexes, fullerenes, carboranes, polymetallic clusters, and even polymers. Thus the whole repertoire of organic, inorganic, and macromolecular chemistry can be applied to tackle the problem of target‐specific enzyme inhibition.
Photoreactive s‐triazine as crosslinking agents for UV‐crosslinkable acrylic pressure‐sensitive adhesives
Authors: Czech Zbigniew , Butwin Agnieszka , Kabatc Janina 
Published: February 2011

AbstractThe UV‐crosslinking as an established technology has been used in many industrial manufacturing processes. New application and technical specifications of UV‐crosslinking lead to continuous development of tailor‐made photoinitiators which can efficiently meet specific requirements. A new class of radical reactive photoinitiators based on s‐triazine has been used for crosslinking of acrylic pressure‐sensitive adhesives containing double bonds. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Encapsulation of disperse dye by phase separation technique using poly(styrene‐maleic acid)
Authors: Fu Shaohai , Zhang Guifang , Ding Lei , Tian Anli , Wang Chaoxia 
Published: February 2011

AbstractC.I. disperse dye blue 60 was encapsulated by poly(styrene‐maleic acid) using phase separation technique, followed by the preparation of the encapsulated disperse dye dispersion. The effects of process conditions on particle size of the dispersion were investigated. The results showed that the particle size of the encapsulated disperse dye dispersion was small, and the stability was excellent when mass ratio of poly(styrene‐maleic acid) to disperse dye (Rp/d), dropping speed of phase separation agent (Ds), disperse dye content in dispersion (Cd), and dispersing time (Dt) were about 20%, 7 mL/min, 5–7.5%, and 1.5 h, respectively. Transmission electron microscope (TEM), zeta potentials, and contact angle indicated that C.I. disperse dye blue 60 was successfully encapsulated by poly(styrene‐maleic acid). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Influence of graphite nanosheets on the structure and properties of PVC‐based nanocomposites
Authors: Al‐Hartomy Omar A. , Al‐Salamy Falleh , Al‐Ghamdi Ahmed A. , Abdel Fatah M. , Dishovsky Nikolay , El‐Tantawy Farid 
Published: February 2011

AbstractPolyvinyl chloride‐ (PVC)‐ based nanocomposites, containing graphite nanosheets (G), which may be used as electromagnetic wave absorbers was developed and investigated. The microstructure of polyvinyl chloride/graphite nanocomposites (PVC/G) were examined by means of X ‐ray diffraction, scanning electron microscopy (SEM), and thermal gravimetric analyses (TGA). SEM image reveals that the graphite nanosheets were well dispersed in the PVC matrix without agglomeration. Thermal stability of the PVC/G nanocomposites is improved as a result of inclusion of graphite nanosheets. The PVC/G nanocomposites were characterized to investigate the effect of dispersion of graphite nanosheets in PVC matrix. The dielectric spectroscopy of PVC/G nanocomposites in frequency range from 1 to 12 GHz has been performed. The results show that PVC/G nanocomposites exhibit high dielectric constant at the measured frequencies. Coefficient of attenuation and coefficient of reflection of PVC/G composites have been also examined in a frequency range from 1 to 12 GHz. The electromagnetic interference shielding effectiveness (EMI) depends on graphite volume fraction in the composite. The results show that the PVC/G represents a new class of conducting lightweight nanomaterial that can absorb electromagnetic waves at microwave frequency and may be promising for future commercial use. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
PVDF/CB composites prepared by novel solvent casting method for low voltage PTC temperature regulation applications
Authors: Acott Samuel M. , Parsons Tamsin M. , Nevell James M. , Perera Semali P. 
Published: February 2011

AbstractA novel solvent casting preparation technique utilizing three variants of poly(vinylidene fluoride) (PVDF) to achieve a thermal cut off and a self regulation effect at a low applied voltage is reported in this study. The positive temperature coefficient (PTC) composites were prepared by dissolving PVDF in 1‐methyl‐2‐pyrrolidone (NMP) solvent, blending with Vulcan® XC72 carbon black (CB) filler, crosslinking with vinyl trimethoxysilane (VTMOS) and quenching in water. All composites displayed a highly macrovoidal structure that promoted a PTC effect when subjected to a thermal expansion effect via an electrical current. Subsequently the current was cut off and self regulation behavior was exhibited. Kynar® 761A PVDF resulted in the strongest PTC effect, and displayed temperature regulation at around 100°C which may be attributed to the highly semi crystalline nature and the larger molecular weight of this polymer in comparison with the other PVDF composites studied. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Exploring Femoral Diaphyseal Shape Variation in Wild and Captive Chimpanzees by Means of Morphometric Mapping: A Test of Wolff's Law
Authors: Morimoto Naoki , De León Marcia S. Ponce , Zollikofer Christoph P.E. 
Published: February 2011

AbstractLong bone shafts (diaphyses) serve as load‐bearing structures during locomotion, implying a close relationship between diaphyseal form and its locomotor function. Diaphyseal form‐function relationships, however, are complex, as they are mediated by various factors such as developmental programs, evolutionary adaptation, and functional adaptation through bone remodeling during an individual's lifetime. The effects of the latter process (“Wolff's Law”) are best assessed by comparing diaphyseal morphologies of conspecific individuals under different locomotor regimes. Here we use morphometric mapping (MM) to analyze the morphology of entire femoral diaphyses in an ontogenetic series of wild and captive common chimpanzees (Pan troglodytes troglodytes). MM reveals patterns of variation of diaphyseal structural and functional properties, which cannot be recognized with conventional cross‐sectional analysis and/or geometric morphometric methods. Our data show that diaphyseal shape, cortical bone distribution and inferred cross‐sectional biomechanical properties vary both along ontogenetic trajectories and independent of ontogeny. Mean ontogenetic trajectories of wild and captive chimpanzees, however, were found to be statistically identical. This indicates that the basic developmental program of the diaphysis is not altered by different loading conditions. Significant differences in diaphyseal shape between groups could only be identified in the distal diaphysis, where wild chimpanzees exhibit higher mediolateral relative to anteroposterior cortical bone thickness. Overall, thus, the hypothesis that Wolff's Law predominantly governs long bone diaphyseal morphology is rejected. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.
The proportional lack of archaeal pathogens: Do viruses/phages hold the key?
Authors: Gill Erin E. , Brinkman Fiona S. L. 
Published: February 2011

AbstractAlthough Archaea inhabit the human body and possess some characteristics of pathogens, there is a notable lack of pathogenic archaeal species identified to date. We hypothesize that the scarcity of disease‐causing Archaea is due, in part, to mutually‐exclusive phage and virus populations infecting Bacteria and Archaea, coupled with an association of bacterial virulence factors with phages or mobile elements. The ability of bacterial phages to infect Bacteria and then use them as a vehicle to infect eukaryotes may be difficult for archaeal viruses to evolve independently. Differences in extracellular structures between Bacteria and Archaea would make adsorption of bacterial phage particles onto Archaea (i.e. horizontal transfer of virulence) exceedingly hard. If phage and virus populations are indeed exclusive to their respective host Domains, this has important implications for both the evolution of pathogens and approaches to infectious disease control.
Prediction of the binding mode between GSK3β and a peptide derived from GSKIP using molecular dynamics simulation
Authors: Tang Xu‐Nan , Lo Cheng‐Wei , Chuang Yu‐Chung , Chen Chao‐Tung , Sun Ying‐Chieh , Hong Yi‐Ren , Yang Chia‐Ning 
Published: February 2011

AbstractGSK3β plays an important role in many physiological functions; dysregulated GSK3β is involved in human diseases such as diabetes, cancer, and Alzheimer's disease. This study uses MD simulations to determine the interaction between GSK3β and a peptide derived from GSKIP, a novel GSK3β interacting protein. Results show that GSKIPtide is inlaid in a binding pocket consisting of an α‐helix and an extended loop near the carboxy‐terminal end. This binding pocket is hydrophobic, and is responsible for the protein–protein interaction of two other GSK3β interacting proteins: FRAT and Axin. The GSKIPtide binding mode is closer to that of AxinGID (in the Axin‐GSK3‐interacting domain). The single‐point mutations of V267G and Y288F in GSK3β differentiate the binding modes between GSK3 and GSKIPtide, AxinGID, and FRATide. The V2677G mutation of GSK3β reduces the GSKIPtide binding affinity by 70% and abolishes the binding affinity with AxinGID, but has no effect on FRATide. However, GSK3β Y288F completely abolishes the FRATide binding without affecting GSKIPtide or AxinGID binding. An analysis of the GSK3β–GSKIPtide complex structure and the X‐ray crystal structures of GSK3β‐FRATide and GSK3β‐AxinGID complexes suggests that the hydroxyl group of Y288 is crucial to maintaining a hydrogen bond network in GSK3β‐FRATide. The hydrophobic side chain of V267 maintains the integrity of helix–helix ridge‐groove hydrophobic interaction for GSK3β‐GSKIPtide and GSK3β‐AxinGID. This study simulates these two mutant systems to provide atomic‐level evidence of the aforementioned experimental results and validate the wild‐type complex structure prediction. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 461–471, 2011.
Time resolved SAXS and RNA folding
Authors: Pollack Lois 
Published: February 2011

AbstractSmall angle X‐ray scattering provides low resolution structural information about macromolecules in solution. When coupled with rapid mixing methods, SAXS reports time‐dependent conformational changes of RNA induced by the addition of Mg2+ to trigger folding. Thus time‐resolved SAXS provides unique information about the global or overall structures of transient intermediates populated during folding. Notably, SAXS provides information about the earliest folding events, which can evade detection by other methods. © 2011 Wiley Periodicals, Inc. Biopolymers 95: 543–549, 2011.