bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heavy atom motions and tunneling in hydrogen transfer reactions: the importance of the pre‐tunneling state
Authors: Limbach Hans‐Heinrich , Schowen K. Barbara , Schowen Richard L. 
Published: May 2010

AbstractArrhenius curves of selected hydrogen transfer reactions in organic molecules and enzymes are reviewed with the focus on systems exhibiting temperature‐independent kinetic isotope effects. The latter can be rationalized in terms of a ‘pre‐tunneling state’ which is formed from the reactants by heavy atom motions and which represents a suitable molecular configuration for tunneling to occur. Within the Bell–Limbach tunneling model, formation of the pre‐tunneling state dominates the Arrhenius curves of the H and the D transfer even at higher temperatures if a large energyEmis required to reach the pre‐tunneling state. Tunneling from higher vibrational levels and the over‐barrier reaction via the transition state which lead to temperature‐dependent kinetic isotope effects dominate the Arrhenius curves only ifEmis small compared to the energy of the transition state. Using published data on several hydrogen transfer systems, the type of motions leading to the pre‐tunneling state is explored. Among the phenomena which lead to large energies of the pre‐tunneling state are (i) cleavage of hydrogen bonds or coordination bonds of the donor or acceptor atoms to molecules or molecular groups in order to allow the formation of the pre‐tunneling state, (ii) the occurrence of an energetic intermediate on the reaction pathway within which tunneling takes place, and (iii) major reorganization of a molecular skeleton, requiring the excitation of specific vibrations in order to reach the pre‐tunneling state. This model suggests a solution to the puzzle of Kwart's findings of temperature‐independent kinetic isotope effects for hydrogen transfer in small organic molecules. Copyright © 2010 John Wiley & Sons, Ltd.
Anisotropic plasticity and chain orientation in polymer glasses
Authors: Ge Ting , Robbins Mark O. 
Published: May 2010

AbstractThe anisotropic mechanical response of oriented polymer glasses is studied through simulations with a coarse‐grained model. Systems are first oriented by uniaxial compression or tension along an axis. Then the mechanical response to subsequent deformation along the same axis or along a perpendicular axis is measured. As in experiments, the flow stress and strain hardening modulus are both larger when deformation increases the degree of molecular orientation produced by prestrain, and smaller when deformation reduces the degree of orientation. All stress curves for parallel prestrains collapse when plotted against either the total integrated strain or the degree of molecular orientation. Stress curves for perpendicular prestrains can also be collapsed. The stress depends on the degree of strain or molecular orientation along the final deformation axis and is independent of the degree of orientation in the perpendicular plane. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1473–1482, 2010
Crystallization kinetics and crystalline morphology of poly(ε‐caprolactone) in blends with grafted rubber particles
Authors: L'Abee Roy , Van Duin Martin , Goossens Han 
Published: May 2010

AbstractThe crystallization behavior of pure PCL and PCL in blends with crosslinked rubber particles was studied under (non)isothermal crystallization conditions, where the rubber particles were grafted with PCL chains via hydrogen abstraction of the aliphatic moieties in PCL. The crystal growth and the organization of crystals into spherulitic superstructures are significantly influenced by the presence of the grafted rubber particles, which act as an excellent nucleating agent for PCL. The nucleating efficiency shows an exponential dependency on the PCL grafting density and, according to an Avrami analysis, an increased PCL grafting density increases the overall crystallization rate of the PCL matrix. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1438–1448, 2010
Polymers on snow: Toward skiing faster
Authors: Giesbrecht Jan L. , Smith Paul , Tervoort Theo A. 
Published: May 2010

AbstractIn this study, small‐scale model skis running down a Nordic ski track were used to investigate the tribological properties of polymer ski soles of a wide range of chemical compositions and surface structures on snow at temperatures of −2 to −4 °C. It was found that ski soles consisting of smooth hydrophilic films of an arithmetical mean surface roughness of less than 0.2 μm experience a considerably higher friction with snow than flat hydrophobic films indicating that for such soles, capillary bridging of the lubricating water film between the snow and the ski base is the dominating friction mechanism. An optimum surface roughness of the ski soles was detected —in the range of 0.2–1 μm. At this surface roughness, sliders are always fast, essentially independent of chemical composition of the ski sole and surface topology. At higher surface roughness, it was found that friction between polymer and snow increases again, especially for structured surfaces that are not aligned in the gliding direction. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1543–1551, 2010
Strain hardening and its relation to Bauschinger effects in oriented polymers
Authors: Senden D. J. A. , van Dommelen J. A. W. , Govaert L. E. 
Published: May 2010

AbstractThe nature of strain hardening in glassy polymers is investigated by studying the mechanical response of oriented polycarbonate in uniaxial extension and compression. The yield stress in extension is observed to increase strongly with predeformation, whereas it slightly decreases in compression (the so‐called Bauschinger effect). Moreover, oriented specimens tend to display increased strain hardening in extension, whereas this nearly vanishes in compression. It is shown that these observations can be captured by the introduction of a viscous contribution to strain hardening in terms of a deformation dependence of the flow stress. This can originate either from a deformation‐induced change in activation volume, as observed for isotactic polypropylene, or from a deformation‐induced change of the rate constant, as observed for polycarbonate, which causes the room temperature yield kinetics of this material to shift from the α into the (α+β) regime. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1483–1491, 2010
Adjustment to cancer and the information needs of people with lung cancer
Authors: Mulcare H. , Schofield P. , Kashima Y. , Milgrom J. , Wirth A. , Bishop M. , Wheeler G. 
Published: May 2010

AbstractObjective: Although typically high, the need for information varies between cancer patients. Few studies, however, have examined the factors that predict patient information needs. This study investigated the influence of different styles of adjustment to cancer on information needs. It was proposed that adjustment styles can be defined in terms of goal pursuit and that adjustment influences information needs as these also arise from goal pursuit.Method: Seventy‐three lung cancer patients were recruited at their first appointment with their radiation oncologist. Participants completed the Patient Information Needs Questionnaire measuring Disease Orientated (DO) information and Action Orientated (AO) information, the Mini‐Mental Adjustment to Cancer Scale, and a purpose‐built measure of cancer‐related personal goals.Results: High levels of the adjustment styles, Fighting Spirit and Anxious Preoccupation, were related to a high need for DO information (p=0.042 and 0.023, respectively). Conversely, high levels of the adjustment style Cognitive Avoidance was related to a low need for DO information (p=0.041). High levels of Anxious Preoccupation were also positively related to a high need for AO information (p=0.018). Support for the proposed theoretical model was also found: information goals predicted information needs and mediated the relationship between Fighting Spirit and DO information need.Conclusions: These findings suggest that information needs vary as a function of adjustment to cancer. Consequently information provision to cancer patients could be more appropriately tailored by attending to how a patient is adjusting to their diagnosis of cancer. Copyright © 2010 John Wiley & Sons, Ltd.
Correlates of quality of life‐related outcomes in breast cancer patients participating in the Pathfinders pilot study
Authors: Smith Sophia K. , Herndon James E. , Lyerly H. Kim , Coan April , Wheeler Jane L. , Staley Tina , Abernethy Amy P. 
Published: May 2010

AbstractObjective: In a pilot study, participation in the Pathfinders program was associated with reductions in distress and despair and improvements in quality of life (QOL) among advanced breast cancer patients. This study explores the relationship between psychosocial resources invoked through the Pathfinders intervention and outcomes.Methods: Advanced breast cancer patients were enrolled in a prospective, single‐arm, pilot study of the Pathfinders psychosocial program. Participants met at least monthly with a licensed clinical social worker who administered the Pathfinders intervention, which focused on strengthening adaptive coping skills, identifying inner strengths, and developing a self‐care plan. Longitudinal assessments over 6 months used validated instruments to assess changes in Pathfinders targets (coping, social support, self‐efficacy, spirituality, and optimism) and outcomes (distress, despair, QOL, and fatigue). Multiple linear regression models examined the joint effect of average changes in target subscales on average outcome changes, adjusted for baseline outcome scores and patient characteristics.Results: Participants (n=44) were: mean age 51 (SD, 12), 20% non‐Caucasian, 50% college degree, and 75% married. Improvements in active coping skills, self‐efficacy, and spiritual meaning/peace significantly correlated with an improvement in despair after adjustment for demographic characteristics (all P<0.05). Improvements in social support significantly correlated with positive changes in distress (P<0.05). Gains in learned optimism independently correlated with an increase in overall QOL (P<0.01).Conclusions: In this pilot assessment, changes in pre‐defined Pathfinders targets such as coping skills, social support, self‐efficacy, spirituality, and optimism correlated with improvements in patient‐reported outcomes. Copyright © 2010 John Wiley & Sons, Ltd.
Family‐oriented multilevel study on the psychological functioning of adolescent children having a mother with cancer
Authors: Huizinga Gea A. , Visser Annemieke , Van der Graaf Winette T. A. , Hoekstra Harald J. , Stewart Roy E. , Hoekstra‐Weebers Josette E. H. M. 
Published: May 2010

AbstractObjective: This study aims to identify the predictive power of adolescents', parents', and illness characteristics on the functioning of adolescents when a mother has cancer.Methods: Two hundred and seventy‐one adolescents, 128 mothers with cancer, and 96 spouses completed standardized questionnaires 1–5 years after diagnosis. Stress response symptoms (SRS), internalizing and externalizing problems were assessed in adolescents. Parents' SRS, trait anxiety, marital satisfaction, and parent–adolescent communication were assessed in parents. Descriptive statistics and multilevel analyses accounting for non‐independence of observations within groups were used.Results: Descriptive analyses showed clinically elevated SRS in 20% of the sons and 30% of the daughters. Daughters experienced more internalizing problems than norm group girls. Multilevel analyses showed that adolescents' female gender and older age were associated with impaired child functioning. Higher levels of parents' trait anxiety and SRS, marital dissatisfaction, and poorer parent–adolescent communication were significant predictors also. Recurrent disease was associated with SRS and internalizing problems, and more intensive treatment with externalizing problems. Female gender and poorer parent–adolescent communication were overall the best predictors.Conclusions: Having a mother with cancer may have far‐reaching consequences for more than a quarter of the adolescent offspring. The multilevel approach of this study identified individual‐level adolescent' risk characteristics as well as family‐level risk characteristics for mental health problems. Adolescents at risk should be referred to health‐care professionals specialized in working with families to help them to adapt to their parent's illness. Copyright © 2010 John Wiley & Sons, Ltd.
What is a psychological intervention? A metareview and practical proposal
Authors: Hodges Laura J. , Walker Jane , Kleiboer Annet M. , Ramirez Amanda J. , Richardson Alison , Velikova Galina , Sharpe Michael 
Published: May 2010

AbstractObjective: What do we mean by a ‘psychological intervention’ in the context of cancer care? It is critical to know what treatments are included under this term, if data from diverse treatment trials are to be summarized in order to inform clinical practice. We, therefore, aimed to determine how the term ‘psychological intervention’ has been defined and used to group and compare interventions in reviews of cancer care.Methods: We conducted a review of existing reviews (a metareview). These included systematic and narrative reviews and meta‐analyses of interventions that were described as ‘psychological’, with the aim of determining: (a) the definitions for ‘psychological interventions’ that were used and (b) the treatments that were included within this category.Results: We identified 66 relevant reviews. Surprisingly, we were unable to find any explicit definition of the term ‘psychological intervention’ in these reviews. The reviews included 79 different treatments with little consistency between reviews in which treatments were included.Conclusions: There is confusion about what ‘psychological intervention’ means in the cancer review literature. A clearer definition is essential to summarize research findings. We propose that rather than simply grouping interventions as ‘psychological’, it would be more useful if reviews focussed on specified domains of the interventions, namely content, proposed mechanism, target outcome, and methods of delivery. This would enable greater specificity in the review question, more meaningful comparisons, and would hopefully provide clearer answers for the readers of the reviews. A checklist for the summarizing of reports of interventions for review is provided. Copyright © 2010 John Wiley & Sons, Ltd.
Barium Salts of Tetrazole Derivatives – Synthesis and Characterization
Authors: Damavarapu Reddy , Klapötke Thomas M. , Stierstorfer Jörg , Tarantik Karina R. 
Published: May 2010

AbstractThe compounds barium tetrazolate (6), barium 5‐aminotetrazolate tetrahydrate (7), barium 5‐nitriminotetrazolate dihydrate (8), barium bis(1H‐5‐nitriminotetrazolate) tetrahydrate (9), barium 1‐methyl‐5‐nitriminotetrazolate monohydrate (10), and barium 2‐methyl‐5‐nitriminotetrazolate dihydrate (11) were synthesized by the reactions of barium hydroxide octahydrate and 1H‐tetrazole (1), 5‐aminotetrazole (2), 1,4H‐5‐nitriminotetrazole (3), 1‐methyl‐5‐nitriminotetrazole (4), and 2‐methyl‐5‐nitraminotetrazole (5), respectively. The compounds were characterized using multi‐nuclear NMR spectroscopy, vibrational (IR and Raman) spectroscopy, elemental analysis, and differential scanning calorimetry. The solid‐state structures of 7–11 were determined using low temperature X‐ray diffraction and a comprehensive characterization is given. In addition, the sensitivities (impact, friction, electrical discharge) of 6–11 were investigated and bomb calorimetric measurements were carried out.
X‐ray crystallographic analysis of adipocyte fatty acid binding protein (aP2) modified with 4‐hydroxy‐2‐nonenal
Authors: Hellberg Kristina , Grimsrud Paul A. , Kruse Andrew C. , Banaszak Leonard J. , Ohlendorf Douglas H. , Bernlohr David A. 
Published: May 2010

AbstractFatty acid binding proteins (FABP) have been characterized as facilitating the intracellular solubilization and transport of long‐chain fatty acyl carboxylates via noncovalent interactions. More recent work has shown that the adipocyte FABP is also covalently modified in vivo on Cys117 with 4‐hydroxy‐2‐nonenal (4‐HNE), a bioactive aldehyde linked to oxidative stress and inflammation. To evaluate 4‐HNE binding and modification, the crystal structures of adipocyte FABP covalently and noncovalently bound to 4‐HNE have been solved to 1.9 Å and 2.3 Å resolution, respectively. While the 4‐HNE in the noncovalently modified protein is coordinated similarly to a carboxylate of a fatty acid, the covalent form show a novel coordination through a water molecule at the polar end of the lipid. Other defining features between the two structures with 4‐HNE and previously solved structures of the protein include a peptide flip between residues Ala36 and Lys37 and the rotation of the side chain of Phe57 into its closed conformation. Representing the first structure of an endogenous target protein covalently modified by 4‐HNE, these results define a new class of in vivo ligands for FABPs and extend their physiological substrates to include bioactive aldehydes.
Chemoprevention of prostate cancer with lycopene in the TRAMP model
Authors: Konijeti Ramdev , Henning Susanne , Moro Aune , Sheikh Ahmed , Elashoff David , Shapiro Ari , Ku Melvin , Said Jonathan W. , Heber David , Cohen Pinchas , Aronson William J. 
Published: May 2010

AbstractBACKGROUNDDietary lycopene combined with other constituents from whole tomatoes was previously found to have greater chemopreventive effects against prostate cancer as compared to pure lycopene provided in a beadlet formulation. We hypothesized that tomato paste would have greater chemopreventive effects in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice relative to equivalent lycopene doses provided from lycopene beadlets.METHODSFifty‐nine TRAMP mice were randomized to a control diet or to diets providing 28 mg lycopene per kg diet from tomato paste (TP) or from lycopene beadlet (LB), and sacrificed at 20 weeks. Prostate histopathology, prostate weight and serum levels of IGF‐I and IGF binding protein‐3 were evaluated.RESULTSThe incidence of prostate cancer was significantly decreased in the LB group relative to the control group (60% vs. 95%, respectively, P = 0.0197) whereas the difference between the TP and control groups was not statistically significant (80% vs. 95%, P = 0.34). There was no difference in prostate weights between the groups. Total lycopene levels in the serum and prostate tissue were similarly elevated in the LB and TP groups relative to the control group. The ratio of 5‐cis‐lycopene to trans‐lycopene in the serum was significantly greater in the LB group relative to the TP group (P = 0.0001). Oxidative DNA damage was significantly reduced in the livers of mice fed LB and TP diets relative to the control group.CONCLUSIONSThis preclinical trial suggests significant chemopreventive activity with a lycopene beadlet‐enriched diet. The chemopreventive effects of lycopene from beadlets versus whole tomato products requires further testing in preclinical and clinical models of prostate cancer. Prostate 70: 1547–1554, 2010. © 2010 Wiley‐Liss, Inc.
Growth of InGaN/GaN light emitting diodes by MOCVD with a thin tapered reactor cell
Authors: Iso Kenji , Takaki Ryohei , Ishihama Yoshiyasu , Inagawa Tomokazu , Takahashi Yuzuru 
Published: May 2010

AbstractInGaN/GaN‐based light emitting diodes (LEDs) can be grown by using metal organic chemical vapor deposition (MOCVD) to make eight, 3‐inch diameter wafers with a thin, tapered reactor cell at atmospheric pressure. The reactor configuration was optimized for the purpose of improving the GaN growth rate and its in‐plane distribution. The growth rate and the layer uniformity of GaN were improved when the reactor cell was narrowed down and tapered. The on‐wafer deviation of the electroluminescence (EL) peak wavelength and power were 5 nm and within 4%, respectively, except at the edge. The full width at half maximum (FWHM) of EL spectrum for an LED grown at atmospheric pressure was consistently smaller than that of one grown at reduced pressure over the entire wavelength range.
GaN/AlN quantum disc single‐nanowire photodetectors
Authors: Rigutti L. , Tchernycheva M. , Bugallo A. De Luna , Jacopin G. , Julien F. H. , Songmuang R. , Monroy E. , Chou S. T. , Lin Y. T. , Tseng P. H. , Tu L. W. , Fortuna F. , Zagonel L. , Kociak M. , Stephan O. 
Published: May 2010

AbstractWe demonstrate single‐nanowire photodetectors based on nanowires containing GaN/AlN quantum disc heterostructures. The structural and electronic properties are investigated by photocurrent and microphotoluminescence spectroscopy, as well as scanning transmission electron microscopy. Single‐nanowire photodetectors are visible‐blind with photoresponse in the ultraviolet spectral range arising from interband absorption in the multi‐quantum disc GaN/AlN heterostructure. The photoconductive gain as high as 104 is measured.
Optical polarization anisotropy of nonpolar InN epilayers
Authors: Wang K. , Yamaguchi T. , Takeda A. , Kimura T. , Kawashima K. , Araki T. , Nanishi Y. 
Published: May 2010

AbstractPhotoluminescence (PL) intensity of both a‐plane and m‐plane InN epilayers has been observed to strongly depend on polarization angle. The PL intensity for polarization perpendicular to c‐axis (E⟂c) is up to four times as that of polarization parallel to c‐axis (E//c) for a‐plane InN, and this ratio is up to seven times for m‐plane InN. The absorption edges of a‐plane samples for the two polarizations are separated by 19 meV, with (E//c) at higher energy side. The PL detected from sample edge also shows such anisotropy. X‐ray diffraction experiments for a series of a‐plane samples, taking orthorhombic distortion of lattice into account, have shown some samples are compressively strained along growth direction and others have negligible strain. With measured strain, the polarization anisotropy has been analyzed by comparing the experimental results with calculated transition energies and relative oscillator strengths including anisotropic in‐plane strain.
AlGaN/GaN HFETs on Fe‐doped GaN substrates
Authors: Oshimura Yoshinori , Takeda Kenichiro , Sugiyama Takayuki , Iwaya Motoaki , Kamiyama Satoshi , Amano Hiroshi , Akasaki Isamu , Bandoh Akira , Udagawa Takashi 
Published: May 2010

AbstractAlGaN/GaN HFETs with different undoped GaN thicknesses were grown on Fe‐doped freestanding GaN substrates by conventional MOVPE. To realize a high drain current, thick undoped GaN is found to be necessary. SIMS measurement shows that Fe is redistributed into the epilayer, by which the scattering center is generated at the channel when the thickness of the undoped GaN is insufficient. We also observed a similar Fe profile in the GaN/sapphire template placed on the side of the Fe‐doped GaN substrate during growth. Therefore, Fe in the Fe‐doped GaN substrate is redistributed not only through a solid but also through vapor. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)