bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of novel alicyclic‐functionalized polyimides prepared from natural—(D)‐camphor
Authors: Zhang Hengsheng , Li Juan , Tian Zhilin , Liu Feng 
Published: February 2013

AbstractIn this article, a new alicyclic‐functionalized diamine, 1,3‐bis(4‐aminophenoxymethylene)‐1,2,2‐trimethylclopentane (BAMT) was successfully synthesized starting from natural —(D)‐camphor through four reaction steps of oxidation to offer a dicaboxylic acid, reduction to offer a diol, nucleophilic substitution to give a dinitro compound and then reduction to give the final diamine. Two alicyclic‐containing polyimides were prepared by polycondensing BAMT with 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐oxydiphthalicanhydride (ODPA), respectively. For the studies of the structure–property relationships of the polyimides, one aromatic polyimide of 4, 4′‐oxydianiline (ODA) polycondensed with ODPA was prepared in comparison. The alicyclic‐containinig polyimides PI (BPDA‐BAMT) and PI (ODPA‐BAMT) maintain good thermal properties with glass transition temperatures (Tg) of 257°C and 240°C, and temperatures at 5% weight loss (T5) of 443°C and 436°C in nitrogen, respectively. The alicyclic polyimides exhibit tensile strengths of 91.9–133 MPa, Young's moduli of 2.75—3.24 GPa, and elongations at break of 5.6–18%. Compared with the aromatic polyimide PI (ODPA‐ODA), PI (ODPA‐BAMT) shows improved transparency with the UV‐Vis transmittance at 500 nm over 80%. In addition, PI (ODPA‐BAMT) displays better solubility than PI (ODPA‐ODA), which has been confirmed by the bigger d‐spacing value of PI (ODPA‐BAMT) than that of PI (ODPA‐ODA) calculated from the Wide‐angle X‐ray Diffraction spectra. This study indicates that the renewable forestry compound, such as natural —(D)‐camphor, could be a good origin for the structural designing and preparation of alicyclic‐containing polyimides with outstanding combined features suitable for advanced microelectronic and optoelectronic applications. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Crystallization behavior of poly(lactide)/poly(β‐hydroxybutyrate)/talc composites
Authors: Tri Phuong Nguyen , Domenek Sandra , Guinault Alain , Sollogoub Cyrille 
Published: February 2013

AbstractThe morphology and miscibility of commercial poly(lactide) (PLA)/poly(β‐hydroxybutyrate) (PHB, from 5 to 20 wt %) blends prepared by melt extrusion method, were investigated using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) observations. The results show that for all the studied blend contents, PLA/PHB blends are immiscible. The effects of PHB and talc on the nonisothermal cold crystallization kinetics of PLA were examined using a differential scanning calorimetry (DSC) at different heating rates. PHB acted as a nucleating agent on PLA and the addition of talc to the blend yielded further improvement, since significant increase in the enthalpy peak was observed for samples containing 10 wt % PHB and talc (from 0.5 to 5 phr). The crystallization kinetics were then examined using the Avrami–Jeziorny and Liu–Mo approach. The simultaneous presence of PHB and talc induced a decrease of the crystallization half time. The evolution of activation energies determined with Kissinger's equation suggests that blending with PHB and incorporating talc promote nonisothermal cold crystallization of PLA. The synergistic nucleating effect of PHB and talc was also observed on isothermal crystallization of PLA from the melt. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of the filler structure of carbon nanomaterials on the electrical, thermal, and rheological properties of epoxy composites
Authors: He Zhiping , Zhang Xiaohua , Chen Minghai , Li Min , Gu Yizhuo , Zhang Zuoguang , Li Qingwen 
Published: February 2013

AbstractCarbon nanotubes (CNTs) and graphene nanosheets (GNSs) were used as fillers in epoxy composites with the aim of increasing the electrical and thermal conductivities of the composites. The filling of pristine CNTs produced the highest electrical conductivity (σ), whereas a high CNT functionalization and the two‐dimensional planar structure of GNSs were promising for improving the thermal conductivity. A combination of CNTs and GNSs exploited the advantages of both. When the CNT fraction was larger than 50 wt %, a higher σ was obtained. When a small amount of functionalized CNTs was added to the GNSs, the thermal conductivity was also increased. The rheological measurements revealed the lowest complex viscosity for the GNS filling and showed the exciting advantages of an easy processing. As a result, the mixed filling also exhibited a much lower viscosity than the pure CNT fillings. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of novel antibacterial monomers (UDMQA) and their potential application in dental resin
Authors: Liang Xiaoxu , Huang Qiting , Liu Fang , He Jingwei , Lin Zhengmei 
Published: February 2013

AbstractTo prepare antibacterial dental resin, a series of novel urethane dimethacrylates quaternary ammonium methacrylate monomers (UDMQAs) with different substituted alkyl chain length were synthesized, and their structures were confirmed by FTIR and 1H‐NMR spectra. The obtained UDMQAs were used to replace 2,2‐Bis[4‐(2‐hydroxy‐3‐methacryloyloxypropyl)‐phenyl]propane (Bis‐GMA) totally as base monomers of dental resin and mixed with Tri‐ethyleneglycol dimethacrylate (TEGDMA) at the mass ratio of 50/50. The properties of these prepared resins like antibacterial activity, double bond conversion (DC), polymerization shrinkage, flexural strength (FS), and modulus (FM), water sorption and sol fraction were investigated. The most commonly used dental resin Bis‐GMA/TEGDMA (50wt/50wt) was chosen as a reference. The results showed that UDMQAs could endow dental resin with antibacterial activity. Compared with Bis‐GMA‐based dental resin, UDMQAs‐based resin had the same or higher DC, lower polymerization shrinkage, lower flexural strength and modulus, and higher water sorption and sol fraction. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Reworking practice through an AfL project: an analysis of teachers’ collaborative engagement with new assessment guidelines
Authors: Hermansen Hege , Nerland Monika 
Published: February 2013

In recent years, the concept of Assessment for Learning (AfL) has travelled across countries, giving rise to a range of educational policy initiatives and school development projects. While researchers have focused on issues such as how formative assessment can support student learning and lead to more efficient classroom practices, less attention has been paid to the collaborative work required to develop shared assessment practices at the school level, and to the integration of AfL‐related principles and tools in the collective practice. This paper focuses on the challenges emerging for a teacher team engaging with an AfL project in a lower secondary school in Norway. By employing concepts and perspectives from social practice theory, AfL is understood as a problem complex that needs to be explored and developed locally. We have analysed data from seven video‐recorded meetings of an AfL team, supplemented by interviews and field notes, in order to make visible the micro processes of teachers' collaborative work. The analysis shows how the teachers needed to rework historically established practices and principles, which in turn called for a negotiation and re‐contextualisation of new concepts and artefacts in their efforts to develop shared assessment practices. This again required ways of representing existing practices and imagining future scenarios. Based on these observations we recommend that AfL projects be understood in their wider curricular, institutional, and social contexts, and that the constructive dimensions of teachers' collaborative work in such projects should be acknowledged.
Development of a new UPLC‐MSMS method for the determination of temozolomide in mice: application to plasma pharmacokinetics and brain distribution study
Authors: Goldwirt Lauriane , Zahr Noel , Farinotti Robert , Fernandez Christine 
Published: February 2013

ABSTRACTA sensitive and accurate liquid chromatography method with mass spectrometry detection was developed and validated for the quantification of temozolomide in mouse plasma and brain. Theophyllin was used as the internal standard. A single‐step protein precipitation was used for plasma and brain sample preparation. The method was validated with respect to selectivity, extraction recovery, linearity, intra‐ and inter‐day precision and accuracy, limit of quantification and stability. The method has a limit of quantification of 50 ng/mL for temozolomide in plasma and 125 ng/g in brain. This method was used successfully to perform brain and plasma pharmacokinetic studies of temozolomide in mice after intraperitoneal administration. Copyright © 2013 John Wiley & Sons, Ltd.
Is there a role for immune checkpoint blockade with ipilimumab in prostate cancer?
Authors: Cha Edward , Small Eric J. 
Published: February 2013

AbstractTreatment for advanced prostate cancer has and will continue to grow increasingly complex, owing to the introduction of multiple new therapeutic approaches with the potential to substantially improve outcomes for this disease. Agents that modulate the patient's immune system to fight prostate cancer – immunotherapeutics – are among the most exciting of these new approaches. The addition of antigen‐specific immunotherapy to the treatment of castration‐resistant prostate cancer (CRPC) has paved the way for additional research that seeks to augment the activity of the immune system itself. The monoclonal antibody ipilimumab, approved in over 40 countries to treat advanced melanoma and currently under phase 2 and 3 investigation in prostate cancer, is thought to act by augmenting immune responses to tumors through blockade of cytotoxic T‐lymphocyte antigen 4, an inhibitory immune checkpoint molecule. Ipilimumab has been studied in seven phase 1 and 2 clinical trials that evaluated various doses, schedules, and combinations across the spectrum of patients with advanced prostate cancer. The CRPC studies of ipilimumab to date suggest that the agent is active in prostate cancer as monotherapy or in combination with radiotherapy, docetaxel, or other immunotherapeutics, and that the adverse event profile is as expected given the safety data in advanced melanoma. The ongoing phase 3 program will further characterize the risk/benefit profile of ipilimumab in chemotherapy‐naïve and ‐pretreated CRPC.
When food is more than nutrition: Understanding emotional eating and overconsumption
Authors: Kemp Elyria , Bui My , Grier Sonya 
Published: February 2013

ABSTRACTThis research examines how more proximal or immediate goals of affect regulation impact goals of weight loss and maintenance. Findings suggest that both psychological and social factors play a role in eating behavior and food overconsumption. Specifically, the narratives of self‐identified emotional eaters reveal that negative emotion, prefactual thinking, and ruminative propensities play major roles in contributing to food‐related consumption. Additionally, emotional eating informants' consumption behavior is greatly impacted by the attitudes and behaviors of others. Several approaches for developing interventions for emotional eaters and furthering transformative research in obesity and overconsumption are discussed.Copyright © 2013 John Wiley & Sons, Ltd.
Fluorescent Probes for G‐Quadruplex Structures
Authors: Vummidi Balayeshwanth R. , Alzeer Jawad , Luedtke Nathan W. 
Published: February 2013

AbstractMounting evidence supports the presence of biologically relevant G‐quadruplexes in single‐cell organisms, but the existence of endogenous G‐quadruplex structures in mammalian cells remains highly controversial. This is due, in part, to the common misconception that DNA and RNA molecules are passive information carriers with relatively little structural or functional complexity. For those working in the field, however, the lack of available tools for characterizing DNA structures in vivo remains a major limitation to addressing fundamental questions about structure–function relationships of nucleic acids. In this review, we present progress towards the direct detection of G‐quadruplex structures by using small molecules and modified oligonucleotides as fluorescent probes. While most development has focused on cell‐permeable probes that selectively bind to G‐quadruplex structures with high affinity, these same probes can induce G‐quadruplex folding, thereby making the native conformation of the DNA or RNA molecule (i.e., in the absence of probe) uncertain. For this reason, modified oligonucleotides and fluorescent base analogues that serve as “internal” fluorescent probes are presented as an orthogonal means for detecting conformational changes, without necessarily perturbing the equilibria between G‐quadruplex, single‐stranded, and duplex DNA. The major challenges and motivation for the development of fluorescent probes for G‐quadruplex structures are presented, along with a summary of the key photophysical, biophysical, and biological properties of reported examples.
Partitioning of Fluoroquinolones on Wastewater Sludge
Authors: Zhou Xuefei , Zhang Yalei , Shi Lu , Chen Jiabin , Qiang Zhimin , Zhang Tian C. 
Published: February 2013

AbstractLaboratory‐scale batch experiments were conducted to investigate the adsorption behavior of eight fluoroquinolones (FQs) on aerobic, anoxic, and anaerobic sludge, under different adsorpiton time, pH, and temperature conditions. Results indicated that adsorption of FQs onto all sludge was a physical sorption process. The relationship of the partitioning coefficient (Kd) and the octanol/water partition coefficient (Kow) for each FQ was established. The adsorbed fraction of FQs on sludge could then be predicted with the Kd. It was calculated that about 50–72% of the FQs were adsorbed on the sludge. Therefore, the adsorption effect must be considered when studying the fate and occurrence of FQs in wastewater treatment systems.
L‐band surface‐coil resonator with voltage‐control impedance‐matching for EPR tooth dosimetry
Authors: Haga Tadatsugu , Hirata Hiroshi , Lesniewski Piotr , Rychert Kevin M. , Williams Benjamin B. , Flood ANN B. , Swartz Harold M. 
Published: February 2013

AbstractA surface‐coil resonator that is capable of voltage‐control for impedance‐matching is described in the context of its application in electron paramagnetic resonance (EPR)‐based tooth dosimetry. Varactor‐based coupling of an 1,150 MHz surface‐coil resonator was achieved to supply RF power. The developed resonator consists of a single‐turn loop, 9 mm in mean diameter; a capacitor made of a polytetrafluoroethylene (PTFE) substrate; a quarter‐wavelength parallel transmission line; a half‐wave line balun, and varactors. The surface coil and the PTFE substrate capacitor were connected to a quarter‐wavelength parallel transmission line. For the newly developed resonator, an RF magnetic field‐generation efficiency of 130 μT/W1/2 was achieved, and the sensitivity of the surface‐coil resonator was investigated with an irradiated tooth. Measurements consisting of six sets of EPR spectra on a 10 Gy irradiated tooth using this newly developed resonator achieved a standard error of the mean (SEM) of 1.1 Gy. This level of accuracy of dose measurements was comparable to the SEM with a previously developed resonator; however, the previous resonator was not capable of voltage‐control for impedance‐matching adjustment, which represents a significant advance in facilitating automation. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B:32–40, 2013
Effects of different field strengths, gradient directions, and acquisitions on fractional anisotropy in diffusion tensor imaging: A tract‐based spatial statistics study
Authors: Seo Youngseob 
Published: February 2013

AbstractThe effects of increasing acquisitions and gradient directions on fractional anisotropy (FA) at 1.5T versus 3T were investigated using an operator‐independent methodology (tract‐based spatial statistics) by minimizing technical differences in image acquisition between the two magnetic resonance imaging platforms and also FA values at roughly equivalent signal‐to‐noise ratio and data acquisition time were compared. Five healthy subjects underwent this experiment. Diffusion tensor imaging (DTI) was performed at 1.5T and 3T. Gradient schemes were 6, 30, and 96 directions. The numbers of acquisitions were 5, 10, and 15 for 6‐direction; 1, 2, and 3 acquisitions for 30‐direction; and 1 acquisition for 96‐direction scheme. FA values in the callosal genu (CG), callosal splenium (CS), posterior limb of the internal capsule (PLIC), and the superior longitudinal fasciculus (SLF) bilaterally were assessed. For 6‐direction scheme at 5 acquisitions, FA values were higher at 1.5T than at 3T. FA values derived using 30‐direction scheme were higher at 3T than 1.5T in the left SLF and PLIC bilaterally. In the CG and CS, FA values at equivalent signal‐to‐noise ratio derived from different acquisitions and gradient directions differed by <7.6%. In the right PLIC and left SLF, FA values measured for 6‐direction scheme differed from 30‐direction scheme by >11% at 1.5T. DTI data acquired at 3T are not always comparable to that at 1.5T. The center of the brain does not appear to be affected but the peripheral white matter appears to be affected by field strengths, number of acquisitions, and gradient directions. © 2013 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 43B:41–48, 2013
Universality for the Focusing Nonlinear Schrödinger Equation at the Gradient Catastrophe Point: Rational Breathers and Poles of the Tritronquée Solution to Painlevé I
Authors: Bertola Marco , Tovbis Alexander 
Published: February 2013

AbstractThe semiclassical (zero‐dispersion) limit of solutions $q=q(x,t,\epsilon)$ to the one‐dimensional focusing nonlinear Schrödinger equation (NLS) is studied in a scaling neighborhood D of a point of gradient catastrophe ($x_0,t_0$). We consider a class of solutions, specified in the text, that decay as $|x| \rightarrow \infty$. The neighborhood D contains the region of modulated plane wave (with rapid phase oscillations), as well as the region of fast‐amplitude oscillations (spikes). In this paper we establish the following universal behaviors of the NLS solutions q near the point of gradient catastrophe: (i) each spike has height $3|q{_0}(x_0,t_0)|$ and uniform shape of the rational breather solution to the NLS, scaled to the size ${\cal O}(\epsilon)$; (ii) the location of the spikes is determined by the poles of the tritronquée solution of the Painlevé I (P1) equation through an explicit map between D and a region of the Painlevé independent variable; (iii) if $(x,t)\in D$ but lies away from the spikes, the asymptotics of the NLS solution $q(x,t, \epsilon)$ is given by the plane wave approximation $q_0(x,t, \epsilon)$, with the correction term being expressed in terms of the tritronquée solution of P1. The relation with the conjecture of Dubrovin, Grava, and Klein about the behavior of solutions to the focusing NLS near a point of gradient catastrophe is discussed. We conjecture that the P1 hierarchy occurs at higher degenerate catastrophe points and that the amplitudes of the spikes are odd multiples of the amplitude at the corresponding catastrophe point. Our technique is based on the nonlinear steepest‐descent method for matrix Riemann‐Hilbert problems and discrete Schlesinger isomonodromic transformations. © 2013 Wiley Periodicals, Inc.
Liposomal Amphotericin B for the Treatment of Cryptococcal Meningitis in HIV/AIDS Patients in India—A Pilot Pharmacokinetic Study
Authors: Jadhav Manoj , Jadhav Priyanka , Shinde Vishal , Kadam Prashant , Kshirsagar Nilima 
Published: February 2013

AbstractThe liposomal formulation of amphotericin B greatly reduces side effects like nephrotoxicity. The present pilot study describes the pharmacokinetic characteristics of liposomal Amp B given to eight patients of cryptococcal meningitis with HIV/AIDS at a dose of 1 and 3 mg/kg/day. We observed that the pharmacokinetic parameters namely AUC, Cmax, CL, Vd, and half‐life were not proportionate with 1 and 3 mg/kg/day dose of Fungiosme™. With 1 and 3 mg/kg/day dose the mean Cmax was found to be 626.54 ± 39.26 and 1049.90 ± 742.75 ng/mL, respectively. In conclusion, liposomal Amp B was observed to be safe and efficacious in the treatment of cryptococcal meningitis in HIV/AIDS patients, however, a pharmacokinetics study with larger cohort of patients of cryptococcal meningitis in HIV AIDS is warranted.
Probing the deep critical zone beneath the Luquillo Experimental Forest, Puerto Rico
Authors: Buss H. L. , Brantley S. L. , Scatena F. N. , Bazilievskaya E. A. , Blum A. , Schulz M. , Jiménez R. , White A. F. , Rother G. , Cole D. 
Published: February 2013

ABSTRACTRecent work has suggested that weathering processes occurring in the subsurface produce the majority of silicate weathering products discharged to the world's oceans, thereby exerting a primary control on global temperature via the well‐known positive feedback between silicate weathering and CO2. In addition, chemical and physical weathering processes deep within the critical zone create aquifers and control groundwater chemistry, watershed geometry and regolith formation rates. Despite this, most weathering studies are restricted to the shallow critical zone (e.g. soils, outcrops). Here we investigate the chemical weathering, fracturing and geomorphology of the deep critical zone in the Bisley watershed in the Luquillo Critical Zone Observatory, Puerto Rico, from two boreholes drilled to 37.2 and 27.0 m depth, from which continuous core samples were taken. Corestones exposed aboveground were also sampled. Weathered rinds developed on exposed corestones and along fracture surfaces on subsurface rocks slough off of exposed corestones once rinds attain a thickness up to ~1 cm, preventing the corestones from rounding due to diffusion limitation. Such corestones at the land surface are assumed to be what remains after exhumation of similar, fractured bedrock pieces that were observed in the drilled cores between thick layers of regolith. Some of these subsurface corestones are massive and others are highly fractured, whereas aboveground corestones are generally massive with little to no apparent fracturing. Subsurface corestones are larger and less fractured in the borehole drilled on a road where it crosses a ridge compared with the borehole drilled where the road crosses the stream channel. Both borehole profiles indicate that the weathering zone extends to well below the stream channel in this upland catchment; hence weathering depth is not controlled by the stream level within the catchment and not all of the water in the watershed is discharged to the stream. Copyright © 2013 John Wiley & Sons, Ltd.