bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prepregnancy Consumption of Fruits and Fruit Juices and the Risk of Gestational Diabetes Mellitus
Authors: Chen Liwei , Hu Frank B. , Yeung Edwina , Tobias Deirdre K. , Willett Walter C. , Zhang Cuilin 
Published: March 2012

OBJECTIVE
Examine the association of prepregnancy habitual consumption of fruits and fruit juices and gestational diabetes mellitus (GDM) risk.

RESEARCH DESIGN AND METHODS
A prospective study among women with at least one singleton pregnancy in the Nurses’ Health Study II from 1991 to 2001.

RESULTS
Among 13,475 women, 860 reported a first diagnosis of GDM. The adjusted relative risks (RRs) for GDM from the lowest to highest quintile of whole fruit consumption were 1.00 (referent), 0.80 (95% CI 0.65–0.98), 0.90 (0.73–1.10), 0.80 (0.64–1.00), and 0.93 (0.76–1.16), respectively. The corresponding RRs for fruit juice were 1.00, 0.82 (0.66–1.01), 0.78 (0.63–0.96), 0.84 (0.68–1.04), and 1.00 (0.81–1.23).

CONCLUSIONS
These data suggest that prepregnancy higher consumption of whole fruits is not associated with an increased GDM risk. The association between fruit juices and GDM risk appears to be nonlinear.
Herbarium specimens, photographs, and field observations show Philadelphia area plants are responding to climate change
Authors: Panchen Zoe A. , Primack Richard B. , Aniśko Tomasz , Lyons Robert E. 
Published: March 2012

• Premise of the study: The global climate is changing rapidly and is expected to continue changing in coming decades. Studying changes in plant flowering times during a historical period of warming temperatures gives us a way to examine the impacts of climate change and allows us to predict further changes in coming decades. The Greater Philadelphia region has a long and rich history of botanical study and documentation, with abundant herbarium specimens, field observations, and botanical photographs from the mid‐1800s onward. These extensive records also provide an opportunity to validate methodologies employed by other climate change researchers at a different biogeographical area and with a different group of species.• Methods: Data for 2539 flowering records from 1840 to 2010 were assessed to examine changes in flowering response over time and in relation to monthly minimum temperatures of 28 Piedmont species native to the Greater Philadelphia region.• Key results: Regression analysis of the date of flowering with year or with temperature showed that, on average, the Greater Philadelphia species studied are flowering 16 d earlier over the 170‐yr period and 2.7 d earlier per 1°C rise in monthly minimum temperature.• Conclusions: Of the species studied, woody plants with short flowering duration are the best indicators of a warming climate. For monthly minimum temperatures, temperatures 1 or 2 mo prior to flowering are most significantly correlated with flowering time. Studies combining herbarium specimens, photographs, and field observations are an effective method for detecting the effects of climate change on flowering times.
Permanent antistatic polypropylene based on polyethylene wax/polypropylene wax grafting sodium acrylate
Authors: Xu Xiang , Xiao Huining , Guan Yong , Li Shuzhao , Wei Dafu , Zheng Anna 
Published: March 2012

AbstractTwo types of permanent antistatic agents, polyethylene wax grafted with sodium acrylate (PEW‐g‐AAS) and polypropylene (PP) wax grafted with sodium acrylate (PPW‐g‐AAS), were prepared using a solution grafting method and applied to PP for enhancing antistatic properties. The grafting degree was determined using back titration method and structures were confirmed by Fourier transform infrared spectroscopy. The antistatic properties of PEW‐g‐AAS/PP blends and PPW‐g‐AAS/PP blends were characterized by surface resistivities (ρs) and volume resistivities (ρv), and a combination of contact angle measurements, scanning electron microscope, permittivity, and dielectric loss were used to investigate the surface and inner structures of the blends. Results showed ρs and ρv of PEW‐g‐AAS/PP blends dropped significantly (4–7 magnitudes) above a critical addition at 10%, where a electrostatic dissipative network formed; PPW‐g‐AAS revealed an inferior antistatic performance than PEW‐g‐AAS due to its better compatibility and smaller dispersed phase in the matrix. Further, the antistatic blends treated in 80°C water, 80°C air, and room temperature were investigated, and the results were interpreted from surface energy. Moreover, the addition of antistatic agent had little impact on tensile strength of the PP matrix. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Creep and strength retention of aramid fibers
Authors: Giannopoulos Ioannis P. , Burgoyne Chris J. 
Published: March 2012

AbstractCreep tests at ambient conditions have been carried out on Kevlar 49 and Technora yarns covering a wide stress spectrum (10–70% average breaking load) for a long period of time (up to a year). The results confirm that Kevlar 49 and Technora yarns show a nonlinear behavior at stresses below 40% of the breaking load and a linear behavior at stresses above 40%. The strength retention following creep for Kevlar 49 and Technora has also been examined. The results show a significant difference in the behavior of the two materials. Kevlar 49 appears to lose strength almost linearly with time, while Technora seems to lose strength much more rapidly. These results would have significant implications for design. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of poly(vinyl acetate) by degenerative transfer polymerization in the presence of iodine
Authors: Xu Wenjing , Zhang Wensheng , Li Wei , Yan Jinlong , Shen Guoyu , Li Jun 
Published: March 2012

AbstractPolymerization of vinyl acetate initiated by 2,2′‐azobis(isobutyronitrile) at 75°C in the presence of iodine has been investigated. The process efficiently controls the number‐average molecular weight and low polydispersities (Mw/Mn ≤ 1.52). Poly(vinyl acetate) with predetermined molecular weight and relatively low polydispersity was successfully synthesized. The polymerization was followed by online 1H‐NMR spectra to investigate the evolution of several compounds in the reaction medium, especially the adduct of α‐iodoisobutyronitrile ((CH3)2(CN)CI) between primary radicals and iodine. The structure of the end groups of poly(vinyl acetate) also was investigated using 1H‐NMR spectra. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of filler–elastomer interactions on the mechanical and nonlinear viscoelastic behaviors of chemically modified silica‐reinforced solution‐polymerized styrene butadiene rubber
Authors: Qu Liangliang , Yu Guozhu , Wang Lili , Li Chuanqing , Zhao Qingsong , Li Jing 
Published: March 2012

AbstractWe explore the effects of surface modification of silica on mechanical and nonlinear viscoelastic behaviors of solution‐polymerized styrene butadiene rubber (SSBR) filled by modified silica (M‐Silica). Compared with pristine silica‐filled SSBR, SSBR reinforced by M‐Silica presents not only better filler dispersity and mechanical properties but also lower internal friction in the certain temperature range. The cure kinetics was investigated in term of curemeter, and the kinetics parameters of SSBR/M‐Silica were found to vary from those of SSBR with pristine silica, indicating that silane coupling agent molecules grafted on the silica surface provoked an enhanced mobility of rubber chain adsorbed onto filler surface and then decreased the barrier of crosslink reaction. Analysis using tube model theory provided more evidence for the reinforcement effect of M‐Silica. SSBR containing M‐Silica exhibited a combination of increments in topological tube‐like constraints and crosslink density in comparison with SSBR filled with pristine silica. Strain dependence of dynamic modulus revealed that the secondary network formed by silica particles was destroyed to some extent with the increase of the hydrophobic character of silica surface. Loss factor of SSBR/M‐Silica was dominated by different mechanism in different temperature range, i.e., secondary filler network at glass transition temperature and rubber–filler interaction and entangled structure above room temperature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Review self‐assembly of amphipathic β‐sheet peptides: Insights and applications
Authors: Bowerman Charles J. , Nilsson Bradley L. 
Published: March 2012

AbstractAmphipathic peptides composed of alternating polar and nonpolar residues have a strong tendency to self‐assemble into one‐dimensional, amyloid‐like fibril structures. Fibrils derived from peptides of general (XZXZ)n sequence in which X is hydrophobic and Z is hydrophilic adopt a putative β‐sheet bilayer. The bilayer configuration allows burial of the hydrophobic X side chain groups in the core of the fibril and leaves the polar Z side chains exposed to solvent. This architectural arrangement provides fibrils that maintain high solubility in water and has facilitated the recent exploitation of self‐assembled amphipathic peptide fibrils as functional biomaterials. This article is a critical review of the development and application of self‐assembling amphipathic peptides with a focus on the fundamental insight these types of peptides provide into peptide self‐assembly phenomena. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 169–184, 2012.
Influence of an Unnatural Amino Acid Side Chain on the Conformational Dynamics of Peptides
Authors: Han Chen , Wang Jianping 
Published: March 2012

AbstractIn this work, a non‐natural amino acid, H‐propargylglycine‐OH (Pra), is chosen to examine the side‐chain effect on the backbone conformation of small peptides. The conformations of two synthesized Pra‐containing tripeptides, Ac‐Pra‐Pra‐NH2 (PPTP) and Ac‐Pra‐Ala‐NH2 (PATP), are examined by infrared (IR) spectroscopy in combination with molecular dynamics (MD) simulations and quantum chemical computations. By analyzing the joint distributions of backbone torsional angles, several significant conformations can be identified for the two tripeptides solvated in D2O. At room temperature, 44 % of PPTP exists in the α‐α conformation and 33 % of PATP exists in the α‐polyproline‐II conformation. Larger structural inhomogeneity is seen in both cases by MD simulations at elevated temperatures. Thus even a small side chain, such as the propargyl group can significantly alter the peptide backbone conformations. The results suggest that there is no overwhelming conformational propensity of the Pra residue in short peptides. IR spectra simulated in the amide‐I region using two different methods, reasonably reproduce the experimental IR spectra and their temperature dependence.
Primary Fragmentation Pathways of Gas Phase [M(Uracil−H)(Uracil)]+ Complexes (M=Zn, Cu, Ni, Co, Fe, Mn, Cd, Pd , Mg, Ca, Sr, Ba, and Pb): Loss of Uracil versus HNCO
Authors: Ali Osama Y. , Randell Nicholas M. , Fridgen Travis D. 
Published: March 2012

AbstractComplexes formed between metal dications, the conjugate base of uracil, and uracil are investigated by sustained off‐resonance irradiation collision‐induced dissociation (SORI‐CID) in a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. Positive‐ion electrospray spectra show that [M(Ura−H)(Ura)]+ (M=Zn, Cu, Ni, Co, Fe, Mn, Cd, Pd, Mg, Ca, Sr, Ba, or Pb) is the most abundant ion even at low concentrations of uracil. SORI‐CID experiments show that the main primary decomposition pathway for all [M(Ura−H)(Ura)]+, except where M=Ca, Sr, Ba, or Pb, is the loss of HNCO. Under the same SORI‐CID conditions, when M is Ca, Sr, Ba, or Pb, [M(Ura−H)(Ura)]+ are shown to lose a molecule of uracil. Similar results were observed under infrared multiple‐photon dissociation excitation conditions, except that [Ca(Ura−H)(Ura)]+ was found to lose HNCO as the primary fragmentation product. The binding energies between neutral uracil and [M(Ura−H)]+ (M=Zn, Cu, Ni, Fe, Cd, Pd ,Mg, Ca, Sr Ba, or Pb) are calculated by means of electronic‐structure calculations. The differences in the uracil binding energies between complexes which lose uracil and those which lose HNCO are consistent with the experimentally observed differences in fragmentation pathways. A size dependence in the binding energies suggests that the interaction between uracil and [M(Ura−H)]+ is ion–dipole complexation and the experimental evidence presented supports this.
Acene‐Modified Triphenylamine Dyes for Dye‐Sensitized Solar Cells: A Computational Study
Authors: Fan Wenjie , Tan Dazhi , Deng Wei‐Qiao 
Published: March 2012

AbstractA series of metal‐free acene‐modified triphenylamine dyes (benzene to pentacene, denoted as TPA‐AC1 to TPA‐AC5) are investigated as organic sensitizers for application in dye‐sensitized solar cells (DSSCs). A combination of density functional theory (DFT), density functional tight‐binding (DFTB), and time‐dependent DFT (TDDFT) approaches is employed. The effects of acene units on the spectra and electrochemical properties of the acene‐modified TPA organic dyes are demonstrated. The dye/(TiO2)46 anatase nanoparticle systems are also simulated to show the electronic structures at the interface. The results show that from TPA‐AC1 to TPA‐AC5 with increasing sizes of the acenes, the absorption and fluorescence spectra are systematically broadened and red‐shifted, but the oscillator strength and electron injection properties are reduced. The molecular orbital contributions show increasing localization on the bridging acene units from TPA‐AC1 to TPA‐AC5. From the theoretical examination of some key parameters including free enthalpy related to the electron injection, light‐harvesting efficiency, and the shift of semiconductor conduction band, TPA‐AC3 with an anthracene moiety demonstrates a balance of the above crucial factors. TPA‐AC3 is expected to be a promising dye with desirable energetic and spectroscopic parameters in the DSSC field, which is consistent with recent experimental work. This study is expected to deepen our understanding of TPA‐based organic dyes and assist the molecular design of new metal‐free dyes for the further optimization of DSSCs.
Antioxidant and prooxidant effects of lanthanum ions on Vicia faba L. seedlings under cadmium stress, suggesting ecological risk
Authors: Wang Cheng-Run , Xiao Jia-Jun , Tian Yuan , Bao Xia , Liu Ling , Yu Yan , Wang Xiao-Rong , Chen Tian-Yu 
Published: March 2012

Abstract
The present study combined chemical analyses and biological measurements to investigate biphasic effects of La on Cd stress in leaves of Vicia faba seedlings, which were hydroponically cultivated for 15 d in the combination of 6 µM CdCl2 and 2 to 480 µM La(NO3)3, respectively. The results showed that contents of Cd first elevated above and then declined below the 6 µM single Cd treatment when 2 to 30 µM extraneous La were combined. Contents of mineral nutrients altered differentially and became imbalanced. No distinct band was observed in catalase (CAT), guaiacol peroxidase (GPX), or ascorbate peroxidase (APX) patterns, but in superoxide dismutase (SOD) isozymes by the supplementation with 8 to 480 µM of extraneous La. Superoxide dismutase and APX activities changed as a U-shaped curve; however, CAT and GPX changed as an inverted U-shaped curve along with increasing La. Moreover, heat shock protein 70 (HSP 70) production was reduced below the single treatment of Cd at 2 to 8 µM of extraneous La and enhanced thereafter. Thus, La at lower concentrations promoted antioxidation against Cd stress; La at higher concentrations turned to prooxidant effects, implicating potential ecological risk. Heat shock protein 70, combined with the antioxidant enzymes, constitutes an integrative defense system, which can be used to estimate the degree of antioxidation or prooxidation of extraneous La to Cd-induced oxidative stress in the seedlings. Environ. Toxicol. Chem. 2012;31:1355–1362. © 2012 SETAC
Comparison of the SnowHydro snow sampler with existing snow tube designs
Authors: Dixon David , Boon Sarah 
Published: March 2012

AbstractSnow tube samplers are the primary method of measuring snow water equivalent (SWE) in the field, as they are considerably less destructive to the snowpack and faster to use than traditional snow pit techniques. This study evaluates the performance of three commonly used snow tube designs: Standard Federal, Meteorological Service of Canada (MSC), and SnowHydro. The Standard Federal and MSC designs have previously been extensively tested; however, the SnowHydro is a new design for which an error analysis has not yet been published. We compared the three designs in a shallow, highly stratified snowpack in both a forest and a clearcut, conditions that are not well represented in previous studies. While the Standard Federal produced SWE values closest to snow pit measurements, the SnowHydro snow tube outperformed the other two designs in terms of coring performance and produced more consistent SWE measurements. Although this is the first published study to quantify the performance of the SnowHydro sampler, additional studies under varying snow conditions are required to adequately quantify sampling errors. Copyright © 2012 John Wiley & Sons, Ltd.
Cancer incidence among Nordic airline cabin crew
Authors: Pukkala Eero , Helminen Mika , Haldorsen Tor , Hammar Niklas , Kojo Katja , Linnersjö Anette , Rafnsson Vilhjálmur , Tulinius Hrafn , Tveten Ulf , Auvinen Anssi 
Published: March 2012

AbstractAirline cabin crew are occupationally exposed to cosmic radiation and jet lag with potential disruption of circadian rhythms. This study assesses the influence of work‐related factors in cancer incidence of cabin crew members. A cohort of 8,507 female and 1,559 male airline cabin attendants from Finland, Iceland, Norway and Sweden was followed for cancer incidence for a mean follow‐up time of 23.6 years through the national cancer registries. Standardized incidence ratios (SIRs) were defined as ratios of observed and expected numbers of cases. A case‐control study nested in the cohort (excluding Norway) was conducted to assess the relation between the estimated cumulative cosmic radiation dose and cumulative number of flights crossing six time zones (indicator of circadian disruption) and cancer risk. Analysis of breast cancer was adjusted for parity and age at first live birth. Among female cabin crew, a significantly increased incidence was observed for breast cancer [SIR 1.50, 95% confidence interval (95% CI) 1.32–1.69], leukemia (1.89, 95% CI 1.03–3.17) and skin melanoma (1.85, 95% CI 1.41–2.38). Among men, significant excesses in skin melanoma (3.00, 95% CI 1.78–4.74), nonmelanoma skin cancer (2.47, 95% CI 1.18–4.53), Kaposi sarcoma (86.0, 95% CI 41.2–158) and alcohol‐related cancers (combined SIR 3.12, 95% CI 1.95–4.72) were found. This large study with complete follow‐up and comprehensive cancer incidence data shows an increased incidence of several cancers, but according to the case‐control analysis, excesses appear not to be related to the cosmic radiation or circadian disruptions from crossing multiple time zones.
Impairment of prostate cancer cell growth by a selective and reversible lysine‐specific demethylase 1 inhibitor
Authors: Willmann Dominica , Lim Soyoung , Wetzel Stefan , Metzger Eric , Jandausch Anett , Wilk Wolfram , Jung Manfred , Forne Ignasi , Imhof Axel , Janzer Andreas , Kirfel Jutta , Waldmann Herbert , Schüle Roland , Buettner Reinhard 
Published: March 2012

AbstractPost‐translational modifications of histones by chromatin modifying enzymes regulate chromatin structure and gene expression. As deregulation of histone modifications contributes to cancer progression, inhibition of chromatin modifying enzymes such as histone demethylases is an attractive therapeutic strategy to impair cancer growth. Lysine‐specific demethylase 1 (LSD1) removes mono‐ and dimethyl marks from lysine 4 or 9 of histone H3. LSD1 in association with the androgen receptor (AR) controls androgen‐dependent gene expression and prostate tumor cell proliferation, thus highlighting LSD1 as a drug target. By combining protein structure similarity clustering and in vitro screening, we identified Namoline, a γ‐pyrone, as a novel, selective and reversible LSD1 inhibitor. Namoline blocks LSD1 demethylase activity in vitro and in vivo. Inhibition of LSD1 by Namoline leads to silencing of AR‐regulated gene expression and severely impairs androgen‐dependent proliferation in vitro and in vivo. Thus, Namoline is a novel promising starting compound for the development of therapeutics to treat androgen‐dependent prostate cancer.
Nicotinic modulation of therapeutic response in vitro and in vivo
Authors: Warren Graham W. , Romano Michelle A. , Kudrimoti Mahesh R. , Randall Marcus E. , McGarry Ronald C. , Singh Anurag K. , Rangnekar Vivek M. 
Published: March 2012

AbstractTobacco use significantly increases the risk of developing cancer. Moreover, there is growing evidence that tobacco use decreases survival in cancer patients. Nicotine, a systemically available component of tobacco, is associated with tumor promotion and decreased apoptosis in cell culture; however, the role of nicotine on response to radiotherapy (RT) or chemoradiotherapy (CRT) in vivo has not been evaluated. Our study evaluated the effects of nicotine administration on cancer cell survival in cell culture and mouse models. Nicotine increased survival in two cell lines following RT in vitro. Nicotine administration in mice during fractionated RT or CRT increased xenograft regrowth as compared to RT or CRT alone. Nicotine increased hypoxia‐inducible factor 1‐alpha (HIF‐1α) expression in tumor xenografts without altering expression of carbonic‐anhydrase, a clinical marker of tumor hypoxia. The effects of nicotine on HIF‐1α expression were transient, returning to baseline levels within 2‐3 days after nicotine removal. Further mechanistic studies indicated that inhibition of phosphoinositide‐3‐kinase (PI3K) prevented nicotine‐mediated increases in HIF‐1α expression as well as the prosurvival effects of nicotine on RT. These findings imply that during tobacco use, nicotine may function as a systemic agent through acute and reversible regulation of HIF‐1α expression and a decreased therapeutic response.