bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple OPR genes influence personality traits in substance dependent and healthy subjects in two American populations
Authors: Luo Xingguang , Zuo Lingjun , Kranzler Henry , Zhang Huiping , Wang Shuang , Gelernter Joel 
Published: January 2008

AbstractPersonality traits are among the most complex quantitative traits. Certain personality traits are associated with substance dependence (SD); genetic factors may influence both. Associations between opioid receptor (OPR) genes and SD have been reported. This study investigated the relationship between OPR genes and personality traits in a case–control sample. We assessed dimensions of the five‐factor model of personality in 556 subjects: 250 with SD [181 European‐Americans (EAs) and 69 African‐Americans (AAs)] and 306 healthy subjects (266 EAs and 40 AAs). We genotyped 20 OPRM1 markers, 8 OPRD1 markers, and 7 OPRK1 markers, and 38 unlinked ancestry‐informative markers in these subjects. The relationships between OPR genes and personality traits were examined using MANCOVA, controlling for gene–gene interaction effects and potential confounders. Associations were decomposed by Roy–Bargmann Stepdown ANCOVA. We found that personality traits were associated as main or interaction effects with the haplotypes, diplotypes, alleles and genotypes at the three OPR genes (0.002 < P < 0.046 from MANCOVA; 0.0004 < P < 0.049 from ANCOVA). Diplotype TTAGGA/TTCAGA at OPRM1 had main effects on Extraversion (P = 0.008), and diplotypes OPRM1⁁TTCAGA/TTCAGA and OPRD1⁁CAC/TAC had interaction effects on Openness (P = 0.010) after conservative correction for multiple testing. The present study demonstrates that the genes encoding the mu‐, delta‐, and kappa‐opioid receptors may contribute to variation in personality traits. Further, the three OPR genes have significant interaction effects on personality traits. This work provides additional evidence that personality traits and SD have a partially overlapping genetic basis. © 2008 Wiley‐Liss, Inc.
Change of chemical composition and hydrogen bonding behavior due to chlorination of crosslinked polyamide membranes
Authors: Kwon Young‐Nam , Tang Chuyang Y. , Leckie James O. 
Published: January 2008

AbstractThe effect of membrane exposure to hypochlorite oxidant on property changes (chemical composition and hydrogen bonding behavior) of four FilmTec© thin film composite crosslinked polyamide membranes has been investigated. Crosslinking densities of the membranes were about 25–35%, with about 3–4 chlorines bound to the repeating unit of the polyamide membranes. This was equivalent to ∼ 39% of all nitrogens being chlorinated in the polyamide membranes assuming the amide nitrogen is the dominant reaction site with chlorine. FTIR spectra showed the amide I band (CO stretching peak at 1663 cm−1) of polyamide membranes shifted to higher wave‐numbers and the peak intensity of the amide II band (NH bending peak at 1541 cm−1) decreased after chlorination. The peak shift and decrease of peak intensity resulted from breakage of hydrogen bonds between CO and NH groups within the polymers. The XPS and FTIR analytical analysis showed that there is no difference in the chlorine attack of polyamide membranes of higher or lower crosslinking density, and that the chlorination breaks and weakens hydrogen bonding. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermally stable poly(propylene carbonate) synthesized by copolymerizing with bulky naphthalene containing monomer
Authors: Gao L. J. , Xiao M. , Wang S. J. , Meng Y. Z. 
Published: January 2008

AbstractTo enhance the thermal and mechanical properties of poly(propylene carbonate) (PPC), the terpolymers were synthesized from carbon dioxide, propylene oxide, and a third monomer, [(2‐naphthyloxy)methyl]oxirane (NMO) using supported zinc glutarate as catalyst. The structure of these terpolymers was confirmed by 1H NMR spectroscopy. The catalytic activity, molecular weight, carbonate unit content, as well as thermal and mechanical properties were investigated extensively. The experimental results showed that the catalytic activity, molecular weight, and carbonate unit content decreased with the incorporation of NMO. DSC measurements indicated that the introduction of NMO increased the glass transition temperature from 38 to 42°C. TGA tests revealed that the thermal decomposition temperature (Tg−5%) of the synthesized terpolymer increased significantly, being 34°C higher than that of pure PPC. Accordingly, the mechanical properties proved also to be enhanced greatly as evidenced by tensile tests. These thermal and mechanical improvements are of importance for the practical process and application of PPC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and comparative study of conducting polyaniline/lead titanate and polyaniline–dodecylbenzenesulfonic acid/lead titanate composites
Authors: Basavaraja C. , Pierson R. , Huh Do Sung 
Published: January 2008

AbstractTo study the effect of a surfactant on the properties of polyaniline (PANI)/metal oxide composites, PANI/lead titanate (PbTiO3) composites were synthesized with different weight percentages (10, 20, 30, 40, and 50 wt %) of PbTiO3 in both the absence and presence of dodecylbenzenesulfonic acid (DBSA) by the polymerization of aniline with ammonium persulfate as an initiator. The structural characteristics and stability, surface characteristics, and electric properties of PANI/PbTiO3 and PANI–DBSA/PbTiO3 were studied and compared. The interfacial interactions and thermal stability of these composites were characterized with X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetry techniques. The results indicate significant changes in the physicochemical properties of the composites with the incorporation of DBSA. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanical properties of thermoplastic elastomers based on silicone rubber and an ethylene–octene copolymer by dynamic vulcanization
Authors: Basuli U. , Chaki T. K. , Naskar K. 
Published: January 2008

AbstractThermoplastic vulcanizates (TPVs) are a special class of thermoplastic elastomers that are generally produced by the simultaneous mixing and crosslinking of a rubber with a thermoplastic polymer at an elevated temperature. Novel peroxide‐cured TPVs based on blends of silicone rubber and the thermoplastic Engage (an ethylene–octene copolymer) have been developed. These TPVs exhibit very good overall mechanical and electrical properties. With an increasing concentration of dicumyl peroxide, the tensile strength, modulus, and hardness of the TPVs increase, whereas the elongation at break decreases. Significant correlations have been obtained from oscillating disc rheometer torque values with various physical properties, such as the modulus and tension set of the TPVs. The aging characteristics and recyclability of the silicone‐based TPVs are also excellent. Scanning electron microscopy photomicrographs of the TPVs have confirmed a dispersed phase morphology. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Grafting of glycidyl methacrylate onto high‐density polyethylene with reaction time in the batch mixer
Authors: Cho Kuk Young , Eom Ji‐Yong , Kim Chang‐Hyeon , Park Jung‐Ki 
Published: January 2008

AbstractThe melt grafting of glycidyl methacrylate (GMA) onto high‐density polyethylene (HDPE) in the presence of free radical initiators was investigated in the batch mixer. The graft content was determined with the titration and FTIR spectroscopy. The graft content increased with the increase of peroxide and initially introduced GMA concentration. Increase of the grafted GMA content resulted in decrease of the melt index. Interestingly, there was a sudden drop of GMA grafting content with the reaction time. It is assumed that depolymerization of GMA have taken place over the ceiling temperature. The crystallinity of the prepared glycidyl methacrylate grafted high density polyethylene (HDPE‐g‐GMA) was determined by the measurement of the heat of fusion. GMA grafted site acted as defect and crystallinity of the HDPE‐g‐GMA decreased with the increase of grafting reaction. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Polymer dispersed liquid crystals based on poly(styrene‐b‐ethylene oxide), poly(bisphenol a carbonate) or poly(methylphenylsiloxane), and 4′‐(hexyloxy)‐4‐biphenyl‐carbonitrile: Analysis of phase diagrams and morphologies generated
Authors: Tercjak Agnieszka , Serrano Elena , Larrañaga Maider , Mondragon Iñaki 
Published: January 2008

AbstractThermodynamic phase behavior was studied for polymer dispersed liquid crystal (PDLC) films consisting of blends of different thermoplastics such as poly (bisphenol A carbonate) (PC), poly(methylphenylsiloxane) (PMPLSi), poly(styrene‐b‐ethylene oxide) (PSEO) block copolymer, and low‐molecular weight 4′‐(hexyloxy)‐4‐biphenyl‐carbonitrile (HOBC) liquid crystals. The phase diagrams of these PDLC systems were built up using thermal transitions determined by differential scanning calorimetry (DSC), transmission optical microscopy (TOM), and dynamic mechanical analysis (DMA). Final morphology of these PDLC films generated by temperature induced phase separation was monitored by TOM. The final morphology of HOBC blends with PC, PSEO, or PMPLSi could be modified by controlling the relative compositions resulting in PDLC systems with small and narrow size‐distribution of nematic droplets, suitable for use in thermo‐optical devices. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Middle Cranial Fossa Anatomy and the Origin of Modern Humans
Authors: Bastir Markus , Rosas Antonio , Lieberman Daniel E. , O'Higgins Paul 
Published: January 2008

AbstractAnatomically, modern humans differ from archaic forms in possessing a globular neurocranium and a retracted face and in cognitive functions, many of which are associated with the temporal lobes. The middle cranial fossa (MCF) interacts during growth and development with the temporal lobes, the midface, and the mandible. It has been proposed that evolutionary transformations of the MCF (perhaps from modification of the temporal lobes) can have substantial influences on craniofacial morphology. Here, we use three‐dimensional (3D) geometric morphometrics and computer reconstructions of computed tomography‐scanned fossil hominids, fossil and recent modern humans and chimpanzees to address this issue further. Mean comparisons and permutation analyses of scaled 3D basicranial landmarks confirm that the MCF of Homo sapiens is highly significantly different (P < 0.001) from H. neanderthalensis, H. heidelbergensis, and Pan troglodytes. Modern humans have a unique configuration with relatively more anterolateral projection of the MCF pole relative to the optic chiasm and the foramen rotundum. These findings are discussed in the context of evolutionary changes in craniofacial morphology and the origins of modern human autapomorphies. In particular, the findings of this study point to variations in the temporal lobe, which, through effects on the MCF and face, are central to the evolution of modern human facial form. Anat Rec, 291:130–140, 2008. © 2008 Wiley‐Liss, Inc.
Cell Signal Transduction Mechanism for Nitric Oxide Regulating Lymphatic Stomata and its Draining Capability
Authors: Li Yan‐Yuan , Li Ji‐Cheng 
Published: January 2008

AbstractWe have previously demonstrated that nitric oxide (NO) is involved in the regulation of the lymphatic stomata. However, the related mechanisms are still unknown. The present study was designed to test the hypothesis that NO–cyclic guanosine monophosphate (cGMP) ‐mediated cytosolic Ca2+ concentration ([Ca2+]i) signaling may contribute to the regulation of the lymphatic stomata and lymph drainage. Using trypan blue as a tracer, the effects of NO‐cGMP‐Ca2+ signal cascade on the lymphatic stomata and lymph absorption were examined by means of scanning electron microscopy. Then, the role of NO in cGMP and [Ca2+]i of rat peritoneal mesothelial cells (RPMCs) was measured by radioimmunoassay and a confocal laser scanning microscope. Our results showed that NO‐donor spermine/nitric oxide complex (Sper/NO) could broaden the opening area of the lymphatic stomata and enhance lymph absorption in a dose‐dependent manner. These NO‐mediated changes could be blocked by 1H‐[1,2,4] oxadiazolo [4,3‐a] quinoxalin‐1‐one (ODQ), a specific inhibitor of soluble guanylyl cyclase, and mimicked by calcium channel blocker nifedipine. Furthermore, Sper/NO enhanced the cGMP level and lessened [Ca2+]i in RPMCs, which was completely abrogated at the presence of ODQ. Nifedipine induced an immediate and marked decrease of [Ca2+]i in the RPMCs, which was not attenuated by addition of Sper/NO, indicating that the Sper/NO‐cGMP signaling system induced [Ca2+]i change was related to the L‐type voltage‐gated calcium channel in the RPMCs. Our results suggest that NO enlarges the opening area of the lymphatic stomata to strengthen the lymph drainage of tracer by means of NO‐cGMP‐[Ca2+]i signal transduction pathway in the RPMCs. Anat Rec, 291:216–223, 2008. © 2008 Wiley‐Liss, Inc.
Fourier transform infrared spectroscopy analysis of the conformational quality of recombinant proteins within inclusion bodies
Authors: Doglia Silvia Maria , Ami Diletta , Natalello Antonino , Gatti‐Lafranconi Pietro , Lotti Marina 
Published: January 2008

AbstractThe solubility of recombinant proteins produced in bacterial cells is considered a key issue in biotechnology as most overexpressed polypeptides undergo aggregation in inclusion bodies, from which they have to be recovered by solubilization and refolding procedures. Physiological and molecular strategies have been implemented to revert or at least to control aggregation but they often meet only partial success and have to be optimized case by case. Recent studies have shown that proteins embedded in inclusion bodies may retain residual structure and biological function and question the former axiom that solubility and activity are necessarily coupled. This allows for a switch in the goals from obtaining soluble products to controlling the conformational quality of aggregated proteins. Central to this approach is the availability of analytical methods to monitor protein structure within inclusion bodies. We describe here the use of Fourier transform infrared spectroscopy for the structural analysis of inclusion bodies both purified from cells and in vivo. Examples are reported concerning the study of kinetics of aggregation and structure of aggregates as a function of expression levels, temperature and co‐expression of chaperones.
Bruce Merrifield and solid‐phase peptide synthesis: A historical assessment
Authors: Mitchell Alexander R. 
Published: January 2008

AbstractBruce Merrifield, trained as a biochemist, had to address three major challenges related to the development and acceptance of solid‐phase peptide synthesis (SPPS). The challenges were (1) to reduce the concept of peptide synthesis on a insoluble support to practice, (2) overcome the resistance of synthetic chemists to this novel approach, and (3) establish that a biochemist had the scientific credentials to effect the proposed revolutionary change in chemical synthesis. How these challenges were met is discussed in this article. © 2008 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 175–184, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Thermodynamics and mechanism of cutinase stabilization by trehalose
Authors: Baptista Ricardo P. , Pedersen Shona , Cabrita Gonçalo J. M. , Otzen Daniel E. , Cabral Joaquim M. S. , Melo Eduardo P. 
Published: January 2008

AbstractTrehalose has been widely used to stabilize cellular structures such as membranes and proteins. The effect of trehalose on the stability of the enzyme cutinase was studied. Thermal unfolding of cutinase reveals that trehalose delays thermal unfolding, thus increasing the temperature at the midpoint of unfolding by 7.2°. Despite this stabilizing effect, trehalose also favors pathways that lead to irreversible denaturation. Stopped‐flow kinetics of cutinase folding and unfolding was measured and temperature was introduced as experimental variable to assess the mechanism and thermodynamics of protein stabilization by trehalose. The main stabilizing effect of trehalose was to delay the rate constant of the unfolding of an intermediate. A full thermodynamic analysis of this step has revealed that trehalose induces the phenomenon of entropy–enthalpy compensation, but the enthalpic contribution increases more significantly leading to a net stabilizing effect that slows down unfolding of the intermediate. Regarding the molecular mechanism of stabilization, trehalose increases the compactness of the unfolded state. The conformational space accessible to the unfolded state decreases in the presence of trehalose when the unfolded state acquires residual native interactions that channel the folding of the protein. This residual structure results into less hydrophobic groups being newly exposed upon unfolding, as less water molecules are immobilized upon unfolding. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 538–547, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Synthesis and Electronic Properties of Monodisperse Oligophenothiazines
Authors: Sailer Markus , Franz Adam W. , Müller Thomas J. J. 
Published: January 2008

AbstractStarting from N‐hexylphenothiazine, a versatile construction kit of brominated and borylated phenothiazines can be easily prepared by a sequence of bromination, bromo–lithium exchange/borylation, and Suzuki coupling. Subsequent Suzuki arylation of the building blocks gives soluble, monodisperse, and structurally well defined oligophenothiazines in good yields. The molecular weights at the peak maximum (Mp), obtained by GPC (gel permeation chromatography), and the actual molecular weights of the oligomer series, obtained by mass spectrometry, show excellent correlation. A QM/MM conformational analysis for the complete series reveals that the obvious butterfly‐shaped phenothiazine structure multiplies and significantly reduces the hydrodynamic volume of the oligomers. The electronic properties (absorption and emission spectroscopy and cyclic voltammetry) give reasonable correlations with the chain length. With regard to the emission maxima, the effective conjugation length is already reached with the hexamer. Oligophenothiazines are highly fluorescent, with high fluorescence quantum yields, and are simultaneously highly electroactive, with low oxidation potentials.
Visualizing the Crystal Structure and Locating the Catalytic Activity of Micro‐ and Mesoporous ZSM‐5 Zeolite Crystals by Using In Situ Optical and Fluorescence Microscopy
Authors: Kox Marianne H. F. , Stavitski Eli , Groen Johan C. , Pérez‐Ramírez Javier , Kapteijn Freek , Weckhuysen Bert M. 
Published: January 2008

AbstractA combination of optical and fluorescence microscopy was used to study the morphology of micro‐ and mesoporous H‐ZSM‐5 zeolite crystals (17×4×4 μm) and to evaluate, in a spatially resolved manner, the effect of mesoporosity, introduced via desilication, on catalytic performance. For this purpose, the oligomerization of various styrene molecules was used as a model reaction, in which the carbocation intermediates formed in the zeolite pores act as reporter molecules. In situ confocal fluorescence measurements after the template removal process showed that the crystals generally consist of three different subunits that have pyramidal boundaries with each other. Examination of these crystals during styrene oligomerization revealed differences in the catalytic activity between the purely microporous and the combined micro‐ and mesoporous crystals. The introduction of intracrystalline mesoporosity limits the formation to dimeric carbocation intermediates and facilitates the transport of styrene molecules inside the zeolite volume. This leads to a more uniform coloration and fluorescence pattern of the crystals. Moreover, the oligomerization of various styrene compounds, which differ in their reactivity, provides a good way of estimating the Brønsted acid strength in a spatially resolved manner, showing a nonhomogeneously distributed Brønsted acidity over the volume of the crystals. More detailed information on the structure of the ZSM‐5 crystals was revealed for mesoporous crystals during the oligomerization of 4‐methoxystyrene. This reaction induced an “explosion” of the crystal leading to the formation of a complex system with at least eight different subunits. Finally, polarized‐light microscopy was used to unravel the pore geometry in these individual building blocks. The observed differences in catalytic behavior between micro‐ and mesoporous ZSM‐5 crystals are strengthened by the microspectroscopic techniques employed, which show that upon desilication the crystal morphology is affected, the product distribution is changed towards less conjugated carbocation intermediates, and that a gradient in Brønsted acid strength appears to be present.
Cost‐effectiveness of temozolomide for the treatment of newly diagnosed glioblastoma multiforme
Authors: Lamers Leida M. , Stupp Roger , van den Bent Martin J. , Al Maiwenn J. , Gorlia Thierry , Wasserfallen Jean‐Blaise , Mittmann Nicole , Jin Seung Soo , Crott Ralph , Uyl‐de Groot Carin A. 
Published: January 2008

AbstractBACKGROUND.The study aimed to compare the cost‐effectiveness of concomitant and adjuvant temozolomide (TMZ) for the treatment of newly diagnosed glioblastoma multiforme versus initial radiotherapy alone from a public health care perspective.METHODS.The economic evaluation was performed alongside a randomized, multicenter, phase 3 trial. The primary endpoint of the trial was overall survival. Costs included all direct medical costs. Economic data were collected prospectively for a subgroup of 219 patients (38%). Unit costs for drugs, procedures, laboratory and imaging, radiotherapy, and hospital costs per day were collected from the official national reimbursement lists based on 2004. For the cost‐effectiveness analysis, survival was expressed as 2.5 years restricted mean estimates. The incremental cost‐effectiveness ratio (ICER) was constructed. Confidence intervals for the ICER were calculated using the Fieller method and bootstrapping.RESULTS.The difference in 2.5 years restricted mean survival between the treatment arms was 0.25 life‐years and the ICER was €37,361 per life‐year gained with a 95% confidence interval (CI) ranging from €19,544 to €123,616. The area between the survival curves of the treatment arms suggests an increase of the overall survival gain for a longer follow‐up. An extrapolation of the overall survival per treatment arm and imputation of costs for the extrapolated survival showed a substantial reduction in ICER.CONCLUSIONS.The ICER of €37,361 per life‐year gained is a conservative estimate. We concluded that despite the high TMZ acquisition costs, the costs per life‐year gained are comparable to accepted first‐line treatment with chemotherapy in patients with cancer. Cancer 2008. © 2008 American Cancer Society.