bluuebunny/crossref_metadata_2025 huggingface dataset:
Subduction‐induced mantle flow, finite strain, and seismic anisotropy: Numerical modeling
Authors: Li Zhong‐Hai , Di Leo Jeanette F. , Ribe Neil M.
Published: May 2014

Surface measurements of shear wave splitting patterns are widely used to infer the mantle circulation around subducting slabs; however, the relation between mantle flow and seismic anisotropy is still elusive. Finite strain is a direct measurement of time‐dependent deformation and has been proposed as a proxy for the crystal‐preferred orientation (CPO) of mantle minerals. We have conducted a series of numerical models to systematically investigate the mantle flow, finite strain, olivine CPO, and SKS wave splitting in oceanic subduction zones with variable slab width. They demonstrate that the preferred orientations of olivine a axes generally agree with the long (extensional) axes of the finite strain ellipsoid (FSE), even in these very complex mantle flow fields; however, neither the a axis nor the FSE axes necessarily aligns with the instantaneous mantle velocity vector. We identify two domains with distinct deformation mechanisms in the central subplate mantle, where simple shear induced by plate advance dominates at shallow depths and produces trench‐normal fast splitting, while pure shear induced by slab rollback dominates the deeper mantle and results in trench‐parallel fast splitting. The SKS splitting patterns are thus dependent on the competing effects of these two mechanisms and also on the subduction partition ratio γ = Xp/Xt: trench parallel when γ< 1 and trench normal when γ>1. In addition, different mantle deformation mechanisms and SKS splitting patterns are observed in the mantle wedge and around the slab edges, which may aid in the general interpretation of seismic anisotropy observations in natural subduction zones.
Recent Progress on Synchrotron‐Based In‐Situ Soft X‐ray Spectroscopy for Energy Materials
Authors: Liu Xiaosong , Yang Wanli , Liu Zhi
Published: May 2014

Soft X‐ray spectroscopy (SXS) techniques such as photoelectron spectroscopy, soft X‐ray absorption spectroscopy and X‐ray emission spectroscopy are efficient and direct tools to probe electronic structures of materials. Traditionally, these surface sensitive soft X‐ray techniques that detect electrons or photons require high vacuum to operate. Many recent in situ instrument developments of these techniques have overcome this vacuum barrier. One can now study many materials and model devices under near ambient, semi‐realistic, and operando conditions. Further developments of integrating the realistic sample environments with efficient and high resolution detection methods, particularly at the high brightness synchrotron light sources, are making SXS an important tool for the energy research community. In this progress report, we briefly describe the basic concept of several SXS techniques and discuss recent development of SXS instruments. We then present several recent studies, mostly in situ SXS experiments, on energy materials and devices. Using these studies, we would like to highlight that the integration of SXS and in situ environments can provide in‐depth insight of material's functionality and help researchers in new energy material developments. The remaining challenges and critical research directions are discussed at the end.
Combining Positive and Negative Dichroic Fluorophores for Advanced Light Management in Luminescent Solar Concentrators
Authors: Debije Michael G. , Menelaou Christopher , Herz Laura M. , Schenning Albertus P. H. J.
Published: May 2014

This work describes the unexpected alignment of a common perylene bisimide fluorescent dye (Lumogen Red305) in a host liquid crystal matrix. The negative dichroic fluorophore orients with the primary absorption/emission dipole, corresponding to the physical long axis of the perylene bisimide core, perpendicular to the director of a host liquid crystal. A second absorption dipole, which lies perpendicular to the primary dipole and corresponding to the physical short axis of the perylene core, lies parallel to the host liquid crystal. Individual illumination of the two absorbing optical transition dipole moments of the Red305 dye results in a single linearly polarized emission. When Red305 is combined with a second positive dichroic Coumarin‐type fluorophore that aligns in the conventional manner in a liquid crystal host, that is, with an absorption dipole along the physical long axis of the fluorophore and the director of the host liquid crystal, advanced light management is possible, such as electrically switchable colors and directing emission light to different edges in a luminescent solar concentrator device.
Generalized model of heat transfer and volatiles evolution inside particles for coal devolatilization
Authors: Yan Binhang , Cheng Yan , Xu Pengcheng , Cao Chenxi , Cheng Yi
Published: May 2014

Devolatilization is acknowledged as the first important step in coal conversion techniques. A comprehensive heat transfer and devolatilization model was established, with special consideration of the particle‐scale physics and chemistry, to predict the internal heat transport and pyrolysis behavior of particles. The chemical percolation devolatilization model with corrected kinetic parameters and structure parameters was validated with a lot of experimental data and then adopted to describe the devolatilization behaviors under a broader range of temperatures, heating rates, and coal types. The newly achieved understanding of the integrated effect of heating rate and coal type on coal devolatilization could help to provide a preliminary coal rank selection method for industrial processes. In particular, in‐depth discussion of the influences of heat conduction, volatiles diffusion, and endothermic heat of devolatilization inside particle indicated the dominant roles of these factors when the intensity of heat transfer was strong or the release of volatiles was rapid. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2893–2906, 2014
N = 2 supersymmetric radiation damping problem on a noncommutative plane
Authors: Abreu Everton M. C. , Mendes Albert C. R. , Oliveira Wilson
Published: May 2014

It is well known that a direct Lagrangian description of radiation damping is still missing. In this paper a specific approach to this problem is used, which is different from the standard way to treat the radiation damping problem. An supersymmetric extension for the model describing radiation damping on the noncommutative plane with electric and magnetic interactions was obtained. The entire supercharge algebra and the total Hamiltonian for the system were analyzed. Finally, noncommutativity features were introduced and their consequences explored.
HPMC layered tablets modified with chitosan and xanthan as matrices for controlled‐release fertilizers
Authors: Melaj Mariana A. , Daraio Marta E.
Published: May 2014

Polymeric matrices based on hydroxypropyl methylcellulose (HPMC) with xanthan (X) or chitosan (Q) and using KNO3 as a model fertilizer were prepared as three‐layered tablets and assayed as controlled release fertilizers (CRFs). The dynamic swelling behavior was analyzed in order to interpret the water uptake mechanism, which in general proved to be non‐Fickian. The presence of HPMC allows a substantially constant rate of fertilizer release. The release mechanism of KNO3 was analyzed and can be described as non‐Fickian diffusion, with release exponents ranging from 0.85 to 1.01, suggesting polymer relaxation as the major process controlling fertilizer release. Durability in soil indicates the blend Q‐HPMC as the more long‐lasting matrix of those tested, remaining at least 34 weeks. Both blends improve HPMC properties for agronomical applications, with X‐HPMC increasing the swelling rate and Q‐HPMC extending the permanence in the soil. Therefore, layered X‐HPMC and Q‐HPMC matrices can be proposed as suitable materials for the development of CRFs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40839.
Evaluation of two chemical crosslinking methods of poly(vinyl alcohol) hydrogels for injectable nucleus pulposus replacement
Authors: Binetti Valerie R. , Fussell Garland W. , Lowman Anthony M.
Published: May 2014

Low back pain caused by intervertebral disc degeneration is one of the most common spinal disorders among patients seeking medical treatment. The most common surgical treatments are spinal fusion and total disc arthroplasty, both of which are very invasive surgical procedures. Nucleus pulposus replacement is an earlier stage intervention for disc degeneration. One of the material classes being studied for this application is hydrogels: a three‐dimensional hydrated network of polymer(s), which mimics the mechanical and physiological properties of the nucleus. Poly(vinyl alcohol) (PVA), poly(vinyl pyrrolidone) (PVP), and poly(ethylene glycol) (PEG) hydrogels have previously been shown to be great candidate materials for injectable nucleus pulposus replacement, but have experienced issues with swelling and mass retention. The addition of chemical crosslinking to the PVA/PVP/PEG hydrogel system will allow tailoring of the swelling, mechanical, injectability, and mass loss properties of the hydrogel network. Two chemical crosslinking methods were evaluated for the PVA/PVP/PEG hydrogel system by characterizing the hydrogels with compression, swelling, and spectroscopy experiments. The results of these experiments led to the selection of the difunctional crosslinking strategy using PEG functionalized with terminal epoxide group (PEG diglycidyl ether) as the preferred crosslinking method. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40843.
Recycling of waste poly(ethylene terephthalate) into flame‐retardant rigid polyurethane foams
Authors: Li Mengjuan , Luo Jun , Huang Yanhong , Li Xiaoqiang , Yu Tianshi , Ge Mingqiao
Published: May 2014

Waste poly(ethylene terephthalate) (PET) textiles were effectively chemical recycling into flame‐retardant rigid polyurethane foams (PUFs). The PET textile wastes were glycolytically depolymerized to bis(2‐hydroxyethyl) terephthalate (BHET) by excess ethylene glycol as depolymerizing agent and zinc acetate dihydrate as catalyst. The PUFs were produced from BHET and polymeric methane diphenyl diisocyanate. The structures of BHET and PUFs were identified by FTIR spectra. The limiting oxygen index (LOI) of the PUFs (≥23.27%) was higher than that of common PUFs (16–18%), because the aromatic substituent in the depolymerized products improved the flame retardance. To improve the LOI of the PUFs, dimethyl methylphosphonate doped PUFs (DMMP‐PUFs) were produced. The LOI of DMMP‐PUFs was approached to 27.69% with the increasing of the doped DMMP. The influences of the flame retardant on the foams density, porosity, and compression properties were studied. Furthermore, the influences of foaming agent, catalyst, and flame retardant on the flame retardation were also investigated. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40857.
Investigation of the interaction between quercetin and human serum albumin by multiple spectra, electrochemical impedance spectra and molecular modeling
Authors: Dai Jie , Zou Ting , Wang Li , Zhang Yezhong , Liu Yi
Published: May 2014

Quercetin (Qu), a flavonoid compound, exists widely in the human diet and exhibits a variety of pharmacological activities. This work is aimed at studying the effect of Qu on the bioactive protein, human serum albumin (HSA) under simulated biophysical conditions. Multiple spectroscopic methods (including fluorescence and circular dichroism), electrochemical impedance spectra (EIS) and molecular modeling were employed to investigate the interaction between Qu and HSA. The fluorescence quenching and EIS experimental results showed that the fluorescence quenching of HSA was caused by formation of a Qu–HSA complex in the ground state, which belonged to the static quenching mechanism. Based on the calculated thermodynamic parameters, it concluded that the interaction was a spontaneous process and hydrogen bonds combined with van der Waal's forces played a major role in stabilizing the Qu–HSA complex. Molecular modeling results demonstrated that several amino acids participated in the binding process and the formed Qu–HSA complex was stabilized by H‐bonding network at site I in sub‐domain IIA, which was further confirmed by the site marker competitive experiments. The evidence from circular dichroism (CD) indicated that the secondary structure and microenvironment of HSA were changed. Alterations in the conformation of HSA were observed with a reduction in the amount of α helix from 59.9% (free HSA) to 56% (Qu–HSA complex), indicating a slight unfolding of the protein polypeptides. Copyright © 2014 John Wiley & Sons, Ltd.
Electrochemiluminescent pH sensor measured by the emission potential of TiO2 nanocrystals and its biosensing application
Authors: Liu Xuan , Wang Nianyue , Zhao Wei , Jiang Hui
Published: May 2014

This work reports for the first time a potential‐based nano‐electrochemiluminescent (ECL) pH sensor, using anatase TiO2 nanocrystals (NCs) as the ECL probe. The first ECL peak potential of the TiO2 NCs shifted negatively with increasing pH, showing a linear range from −0.47 V (vs Ag/AgCl) at pH 3 to −1.06 V at pH 10. This phenomenon was attributed to the absorption of ‘potential‐determining ions’ of OH− on the surface of TiO2 NCs, leading to larger impedance of the electron injection. Other common ‘potential‐determining ions’, such as phosphate, induced a slight potential shift of 0.03 V at a concentration of 0.1 M. Using urease as an enzyme model, a urea biosensor was developed by the simultaneous modification of urease and TiO2 NCs on indium–tin oxide (ITO) electrodes. The biosensor, measured on the basis of the pH increase caused by the enzyme catalysis reaction, had a linear range of 0.01–2.0 mM, with a potential shift of 0.175 V. The as‐prepared pH sensor, which has simple construction procedures and acceptable sensitivity and selectivity, may provide new avenues for the construction of ECL bioanalytical methodologies. Copyright © 2014 John Wiley & Sons, Ltd.
Liquid chromatography–tandem mass spectrometric assay for the determination of vaccarin in rat plasma: application to a pharmacokinetic study
Authors: Yang Guilin , Zhang Nan , Wang Tiance , Zhang Shudong , Xu Rihao , Zhu Zhicheng , Liu Kexiang
Published: May 2014

Vaccarin, a flavonoid glycoside, is considered one of the major active constituents of Vaccaria segetalis. A simple and specific liquid chromatography–tandem mass spectrometric method was developed and validated for quantifying vaccarin in rat plasma following intravenous dosing. Plasma samples were precipitated with methanol and separated on a Venusil‐C18 analytical column (2.1 × 50 mm, 5 µm particles) with gradient elution consisting of methanol and 0.1% (v/v) formic acid as the mobile phase. The detection was performed on an Agilent Triple Quad LC/MS with electrospray ionization inlet in the positive multiple reaction monitoring mode. Good linearity was achieved over the concentration range of 12.5–25,000 ng/mL (r2 > 0.99). Intra‐ and inter‐day precisions were <9.1%, and accuracy ranged from −2.8 to 8.7%. The lower limit of quantification for vaccarin was 12.5 ng/mL, and the analyte was stable under various storage conditions. This validated method was successfully applied to the preliminary pharmacokinetic studies of vaccarin following intravenous administrations of 1.21, 2.41, and 4.82 mg/kg vaccarin in rats. Copyright © 2014 John Wiley & Sons, Ltd.
Ultra‐high‐performance liquid chromatography tandem mass spectrometry method for the determination of gambogenic acid in dog plasma and its application to a pharmacokinetic study
Authors: Chen Jin Pei , Wang Dian Lei , Yang Li Li , Wang Chen Yin , Wang Shan Shan
Published: May 2014

A highly sensitive and rapid ultra‐high‐performance liquid chromatography–tandem mass spectrometry method was developed and validated for the determination of gambogenic acid in dog plasma. Gambogic acid was used as an internal standard (IS). After a simple liquid–liquid extraction by ethyl acetate, the analyte and internal standard were separated on an Acquity BEH C18 (100 × 2.1 mm, 1.7 µm; Waters ) column at a flow rate of 0.2 mL/min, using 0.1% formic acid–methanol (10:90, v/v) as mobile phase. Electrospray ionization source was applied and operated in the positive ion mode. Multiple reaction monitoring mode with the transitions m/z 631.3 → 507.3 and m/z 629.1 → 573.2 was used to quantify gambogenic acid and the internal standard, respectively. The calibration curves were linear in the range of 5–1000 ng/mL, with a coefficient of determination (r) of 0.999 and good calculated accuracy and precision. The low limit of quantification was 5 ng/mL. The intra‐and inter‐day precisions (relative standard deviations) were <15%. The methodology recoveries were more than 66.63%. This validated method was successfully applied to a pharmacokinetic study after intravenous injection administration of gambogenic acid in dogs at a dose of 1 mg/kg. Copyright © 2014 John Wiley & Sons, Ltd.
The Quest for Significance Model of Radicalization: Implications for the Management of Terrorist Detainees
Authors: Dugas Michelle , Kruglanski Arie W.
Published: May 2014

Radicalization and its culmination in terrorism represent a grave threat to the security and stability of the world. A related challenge is effective management of extremists who are detained in prison facilities. The major aim of this article is to review the significance quest model of radicalization and its implications for management of terrorist detainees. First, we review the significance quest model, which elaborates on the roles of motivation, ideology, and social processes in radicalization. Secondly, we explore the implications of the model in relation to the risks of prison radicalization. Finally, we analyze the model's implications for deradicalization strategies and review preliminary evidence for the effectiveness of a rehabilitation program targeting components of the significance quest. Based on this evidence, we argue that the psychology of radicalization provides compelling reason for the inclusion of deradicalization efforts as an essential component of the management of terrorist detainees. Copyright © 2014 John Wiley & Sons, Ltd.
PAX1/SOX1 DNA methylation and cervical neoplasia detection: a Taiwanese Gynecologic Oncology Group (TGOG) study
Authors: Lai Hung‐Cheng , Ou Yu‐Che , Chen Tze‐Chien , Huang Huei‐Jean , Cheng Ya‐Min , Chen Chi‐Hau , Chu Tang‐Yuan , Hsu Shih‐Tien , Liu Cheng‐Bin , Hung Yao‐Ching , Wen Kuo‐Chang , Yu Mu‐Hsien , Wang Kung‐Liahng
Published: May 2014

We aimed to determine whether PAX1/SOX1 methylation could be translated to clinical practice for cervical neoplasia detection when used alone and in combination with current cytology‐based Pap screening. We conducted a multicenter case–control study in 11 medical centers in Taiwan from December 2009 to November 2010. Six hundred seventy‐six patients were included in the analysis, including 330 in the training set and 346 in the testing set. Multiplex quantitative methylation‐specific polymerase chain reaction (PCR) was performed with a TaqMan probe system using a LightCycler 480 Real‐Time PCR System (Roche). The level of human papilloma virus (HPV) was analyzed using a Hybrid Capture 2 system (Digene). Receiver operating characteristic curves were generated to obtain the best cutoff values from the training data set. The sensitivities, specificities, and accuracies were validated in the testing set. The sensitivities for methylated (m) PAX1m and SOX1m and HPV testing for detecting CIN3+ lesions were 0.64, 0.71, and 0.89, and the specificities were 0.91, 0.77, and 0.68, respectively. Combined parallel testing of PAX1m/SOX1m tests with Pap smearing showed superior specificity (0.84/0.71 vs. 0.66, respectively) and similar sensitivity (0.93/0.96 vs. 0.97) to the combination of Pap smear results and HPV testing. Thus, combined parallel testing using Pap smears and PAX1 or SOX1 methylation tests may provide better performance than a combination of Pap smears with HPV testing in detection for cervical neoplasia.
Polyamines cause elevation of steroid 5α‐reductase mRNA levels by suppressing mRNA degradation in C6 glioma cells
Authors: Morita Kyoji , Lee Mi‐Sook , Her Song , Nishibori Naoyoshi
Published: May 2014

Polyamines are widely distributed in living organisms, and considered to play a potential role in various cellular processes. The effects of polyamines on gene expression as well as cell proliferation have been suggested to be closely associated with the physiological and pathological functions. However, it seems necessary to investigate their potential roles in the regulation of cellular metabolism and functions. Previously, glial cells have been suggested to be involved in the protection and preservation of neuronal functions, probably through the production of neurotrophic factors in the brain. On the other hand, neuroactive 5α‐reduced steroids promote glial cell differentiation, resulting in enhancement of their ability to produce brain‐derived neurotrophic factor (BDNF). Based on these findings, polyamines are assumed to stimulate the expression of the gene encoding steroid 5α‐reductase (5α‐R), which can induce the production of neuroactive 5α‐reduced steroids in glial cells. The effects of polyamines on 5α‐R mRNA levels in C6 glioma cells were examined as a model experiment. In consequence, spermine (SPM) and spermidine (SPD), but not putrescine (PUT), have been shown to elevate 5α‐R mRNA levels without activating the 5α‐R promoter. Furthermore, SPM increased 5α‐R mRNA levels under the conditions in which the mRNA biosynthesis was inhibited. Therefore, it can be speculated that polyamines increase 5α‐R mRNA levels as a consequence of suppressing the degradation of mRNA.
Radical‐Cation Dimerization Overwhelms Inclusion in [n]Pseudorotaxanes
Authors: Nchimi‐Nono Katia , Dalvand Parastoo , Wadhwa Kuldeep , Nuryyeva Selbi , Alneyadi Shaikha , Prakasam Thirumurugan , Fahrenbach Albert C. , Olsen John‐Carl , Asfari Zouhair , Platas‐Iglesias Carlos , Elhabiri Mourad , Trabolsi Ali
Published: May 2014

Suppression of the dimerization of the viologen radical cation by cucurbit[7]uril (CB7) in water is a well‐known phenomenon. Herein, two counter‐examples are presented. Two viologen‐containing thread molecules were designed, synthesized, and thoroughly characterized by 1H DOSY NMR spectrometry, UV/Vis absorption spectrophotometry, square‐wave voltammetry, and chronocoulometry: BV4+, which contains two viologen subunits, and HV12+, which contains six. In both threads, the viologen subunits are covalently bonded to a hexavalent phosphazene core. The corresponding [3]‐ and [7]pseudorotaxanes that form on complexation with CB7, that is, BV4+⊂(CB7)2 and HV12+⊂(CB7)6, were also analyzed. The properties of two monomeric control threads, namely, methyl viologen (MV2+) and benzyl methyl viologen (BMV2+), as well as their [2]pseudorotaxane complexes with CB7 (MV2+⊂CB7 and BMV2+⊂CB7) were also investigated. As expected, the control pseudorotaxanes remained intact after one‐electron reduction of their viologen‐recognition stations. In contrast, analogous reduction of BV4+⊂(CB7)2 and HV12+⊂(CB7)6 led to host–guest decomplexation and release of the free threads BV2(.+) and HV6(.+), respectively. 1H DOSY NMR spectrometric and chronocoulometric measurements showed that BV2(.+) and HV6(.+) have larger diffusion coefficients than the corresponding [3]‐ and [7]pseudorotaxanes, and UV/Vis absorption studies provided evidence for intramolecular radical‐cation dimerization. These results demonstrate that radical‐cation dimerization, a relatively weak interaction, can be used as a driving force in novel molecular switches.
Modified SWCNTs with Amphoteric Redox and Solubilizing Properties
Authors: Rodríguez‐Pérez Laura , García Raúl , Herranz María Ángeles , Martín Nazario
Published: May 2014

Invited for the cover of this issue is the group of Nazario Martín at Universidad Complutense de Madrid and IMDEA Nanoscience. The image depicts how doubly functionalized single‐wall carbon nanotubes (SWCNTs) can be switched from being soluble in aqueous solutions (with a Br− counteranion) to being soluble in organic solvents (with a PF6− counteranion). Read the full text of the article at 10.1002/chem.201400183.
Multiple Ambient Hydrolysis Deposition of Tin Oxide into Nanoporous Carbon To Give a Stable Anode for Lithium‐Ion Batteries
Authors: Raju Vadivukarasi , Wang Xingfeng , Luo Wei , Ji Xiulei
Published: May 2014

A novel ambient hydrolysis deposition (AHD) methodology that employs sequential water adsorption followed by a hydrolysis reaction to infiltrate SnO2 nanoparticles into the nanopores of mesoporous carbon in a conformal and controllable manner is introduced. The empty space in the SnO2/C composites can be adjusted by varying the number of AHD cycles. An SnO2/C composite with an intermediate SnO2 loading exhibited an initial specific delithiation capacity of 1054 mAh g−1 as an anode for Li‐ion batteries. The capacity contribution from SnO2 in the composite electrode approaches the theoretical capacity of SnO2 (1494 mAh g−1) if both Sn alloying and SnO2 conversion reactions are considered to be reversible. The composite shows a specific capacity of 573 mAh g−1 after 300 cycles, that is, one of the most stable cycling performances for SnO2/mesoporous carbon composites. The results demonstrated the importance of well‐tuned empty space in nanostructured composites to accommodate expansion of the electrode active mass during alloying/dealloying and conversion reactions.
Global heat loss and thermal stress analysis in Czochralski crystal growth
Authors: Li Xiaolong , Liu Yulan , Wang Biao , Zhu YunZhong
Published: May 2014

Based on our invention of an energy‐efficient Czochalski crystal growth furnace, a 2D‐axisymmetric numerical simulation model of LiNbO3 crystal growth is developed. The heat transfer, melt and gas flow, radiation and the interface deflection have been examined. Heat losses in the furnace and the insulator, as well as the heating power and thermal stress distribution at three stages of crystal growth are calculated in detail. It is found that a large proportion of heat dissipates through the water‐cooling system, and at the steel shell of the furnace, gas convection heat transfer is the major cooling mechanism. Less heat dissipation by radiation and more heat flux by gas convection to the crystal sidewall results in a larger concentrated thermal stress, which may induce large crystal cracks in the growth process. The simulation results of heating power are in coincidence with the actual power of our furnace, which verifies the feasibility of our model. The detailed information with respect to the device obtained from simulation can help to optimize the energy‐saving design and growth process.
Determination of the phase diagram for the crystallization of L‐asparaginase II by a turbidity technique ‐ part II. ‐MPD and crystallography studies‐
Authors: Liu Yi , Ulrich Joachim
Published: May 2014

The phase diagram for the crystallization of L‐asparaginase II including the metastable zone width (MZW), in the presence of PEG6000 and ethanol, respectively, has been studied by an online turbidity technique out of the crystallization in solution (see part I of this work ). Here this paper describes a further investigation on constructing a phase diagram including MZW for the crystallization of L‐asparaginase II with a different precipitant agent of 2‐methyl‐2, 4‐pentandiol (MPD). Along with the phase diagram, the single crystal X‐ray data were successfully collected at 100K from a crystal formed in the presence of 26% (v/v) MPD. The crystals indicate an orthorhombic form and belong to the space group of P212121 with the unit cell parameters a = 93.9, b = 125.77, c = 151.75Å. The crystal diffracted up to a resolution of 2.88 Å.
Microwave‐assistant route to hybrid semiconductor nanocrystals with quasi solution‐solid‐solid mechanism
Authors: Bao Chunlin , Zhu Guoxing , Shen Mengqi , Liu Miaomiao , Xiao Peng
Published: May 2014

A facile microwave‐assistant route was developed for the synthesis of hybrid nanocrystals. Colloidal hybrid nanocrystals, Ag2S‐CdS, were prepared by using Ag2S nanocrystals and cadmium diethyldithiocarbamate as raw materials under microwave irradiation. The fast ion conductor, Ag2S nanocrystal, catalyzes the growth of CdS nano‐building blocks through a quasi solution‐solid‐solid mechanism. The ultraviolet‐visible absorption and photoluminescence spectra of the Ag2S‐CdS hybrid nanocrystals were investigated. One of the main advantages for this synthesis is the efficiency of dramatically reducing overall processing time. This report provides a new route for the growth of semiconductor hybrid nanocrystals based on Ag2S and may be extended to the preparation of other hybrid colloidal nanostructures.
Parenting behaviors and vagal tone at six months predict attachment disorganization at twelve months
Authors: Holochwost Steven J. , Gariépy Jean‐Louis , Propper Cathi B. , Mills‐Koonce W. Roger , Moore Ginger A.
Published: May 2014

The authors investigated the relationships among parenting behaviors, infant vagal tone, and subsequent attachment classification. Vagal tone was assessed among 6‐month olds (n = 95) during the still‐face paradigm (SFP) via respiratory sinus arrhythmia (RSA), while attachment security and disorganization were measured at 12 months during the strange situation procedure (SSP). Infants demonstrating higher levels of RSA during the normal interaction and reunion episodes of the SFP whose mothers were also rated as negative‐intrusive exhibited higher levels of attachment disorganization at 12 months, while infants with lower RSA and mothers who were negative‐intrusive did not exhibit higher levels of disorganization. These results suggest that high levels of RSA may not be adaptive within the context of negative‐intrusive parenting. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1423–1430, 2014.
The therapeutic process in psychological treatments for eating disorders: A systematic review
Authors: Brauhardt Anne , de Zwaan Martina , Hilbert Anja
Published: May 2014

Objective

For eating disorders, a vast number of investigations have demonstrated the efficacy of psychological treatments. However, evidence supporting the impact of therapeutic process aspects on outcome (i.e., process‐outcome research) has not been disentangled.

Method

Using the Generic Model of Psychotherapy (GMP) to organize various process aspects, a systematic literature search was conducted on psychological treatment studies for anorexia nervosa, bulimia nervosa, binge‐eating disorder, and eating disorders not otherwise specified.

Results

Improved outcomes resulted for family‐based treatment compared to individual treatment, for individual compared to group treatment, booster sessions, and positive patient expectations (GMP contract aspect); for nutritional counseling and exercising but not exposure with response prevention as adjunct interventions (therapeutic operations); for highly motivated patients and, to a lesser extent, for therapeutic alliance (therapeutic bond); as well as for rapid response and longer overall treatment duration (temporal patterns). Regarding other GMP aspects, studies on self‐relatedness were completely lacking and in‐session impacts were rarely investigated.

Discussion

As most studies assessed only a limited number of process aspects, the ability to draw conclusions about their overall impact regarding outcome is rather limited. Therefore, future process‐outcome research is needed beyond investigations of treatment efficacy for eating disorders. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:565–584)
First Examples of Near‐Infrared Luminescent Poly(methyl methacrylate)‐Supported Metallopolymers Based on Zn2Ln‐Arrayed Schiff Base Complexes
Authors: Miao Tie‐Zheng , Feng Wei‐Xu , Zhang Zhao , Su Pei‐Yang , Lü Xing‐Qiang , Song Ji‐Rong , Fan Dai‐Di , Wong Wai‐Kwok , Jones Richard A. , Su Cheng‐Yong
Published: May 2014

The first examples of Wolf Type II Zn2Ln‐containing metallopolymers poly{MMA‐co‐[Zn2(L)2(4‐vp)2Ln(NO3)3]} (Ln = La, Nd, Yb, Er, Gd; H2L = N,N′‐bis(salicylidene)ethylene‐1,2‐diamine; 4‐vp = 4‐vinylpyridine; MMA = methyl methacrylate) are obtained from the controlled copolymerization of heterotrinuclear Zn2Ln‐arrayed complexes [Zn2(L)2(4‐vp)2Ln(NO3)3] (Ln = La, 1; Ln = Nd, 2; Ln = Yb, 3; Ln = Er, 4; Ln = Gd, 5) with MMA. The strong and characteristic near‐infrared (NIR) luminescent Ln3+‐centered emission for each of the PMMA‐supported poly{MMA‐co‐[Zn2(L)2(4‐vp)2Ln(NO3)3]} (Ln = Nd, Yb, Er) hybrid materials is retained with somewhat higher intrinsic quantum yields than those of the respective Zn2Ln‐arrayed complex. Especially for poly(MMA‐co‐3), which has more efficient sensitization from both ligand‐centered singlet (1LC) and triplet (3LC) states of the chromophores, the concentration self‐quenching of Yb3+‐based NIR luminescence could be effectively prevented.
Experimental and theoretical insights into photochemical transformation kinetics and mechanisms of aqueous propylparaben and risk assessment of its degradation products
Authors: An Taicheng , Fang Hansun , Li Guiying , Wang Shilong , Yao Side
Published: May 2014

The kinetics and mechanisms of ultraviolet photochemical transformation of propylparaben (PPB) were studied. Specific kinetics scavenging experiments coupled with quantum yield determinations were used to distinguish the roles of various reactive species induced by self-sensitized and direct photolysis reactions, and the excited triplet state of PPB (3PPB*) was identified as the most important species to initiate the photochemical degradation of PPB in aquatic environments. The computational results of time-resolved absorption spectra proved that 3PPB* is a highly reactive electron acceptor, and a head-to-tail hydrogen transfer mechanism probably occurs through electron coupled with proton transfer. Physical quenching by, or chemical reaction of 3PPB* with, O2 was confirmed as a key step affecting the initial PPB transformation pathways and degradation mechanisms. The transformation products were identified and the toxicity evolutions of PPB solutions during photochemical degradation under aerobic and anaerobic conditions were compared. The results indicate that anaerobic conditions are more likely than aerobic conditions to lead to the elimination and detoxification of PPB but less likely to lead to PPB mineralization. Environ Toxicol Chem 2014;33:1809–1816. © 2014 SETAC
Next‐generation sequencing sheds light on the natural history of hepatitis C infection in patients who fail treatment
Authors: Abdelrahman Tamer , Hughes Joseph , Main Janice , McLauchlan John , Thursz Mark , Thomson Emma
Published: May 2014

High rates of sexually transmitted infection and reinfection with hepatitis C virus (HCV) have recently been reported in human immunodeficiency virus (HIV)‐infected men who have sex with men and reinfection has also been described in monoinfected injecting drug users. The diagnosis of reinfection has traditionally been based on direct Sanger sequencing of samples pre‐ and posttreatment, but not on more sensitive deep sequencing techniques. We studied viral quasispecies dynamics in patients who failed standard of care therapy in a high‐risk HIV‐infected cohort of patients with early HCV infection to determine whether treatment failure was associated with reinfection or recrudescence of preexisting infection. Paired sequences (pre‐ and posttreatment) were analyzed. The HCV E2 hypervariable region‐1 was amplified using nested reverse‐transcription polymerase chain reaction (RT‐PCR) with indexed genotype‐specific primers and the same products were sequenced using both Sanger and 454 pyrosequencing approaches. Of 99 HIV‐infected patients with acute HCV treated with 24‐48 weeks of pegylated interferon alpha and ribavirin, 15 failed to achieve a sustained virological response (six relapsed, six had a null response, and three had a partial response). Using direct sequencing, 10/15 patients (66%) had evidence of a previously undetected strain posttreatment; in many studies, this is interpreted as reinfection. However, pyrosequencing revealed that 15/15 (100%) of patients had evidence of persisting infection; 6/15 (40%) patients had evidence of a previously undetected variant present in the posttreatment sample in addition to a variant that was detected at baseline. This could represent superinfection or a limitation of the sensitivity of pyrosequencing. Conclusion: In this high‐risk group, the emergence of new viral strains following treatment failure is most commonly associated with emerging dominance of preexisting minority variants rather than reinfection. Superinfection may occur in this cohort but reinfection is overestimated by Sanger sequencing. (Hepatology 2015;61:88–97)
Successful anti-scavenger receptor class B type I (SR-BI) monoclonal antibody therapy in humanized mice after challenge with HCV variants with in vitro resistance to SR-BI-targeting agents
Authors: Vercauteren Koen , Van Den Eede Naomi , Mesalam Ahmed Atef , Belouzard Sandrine , Catanese Maria Teresa , Bankwitz Dorothea , Wong-Staal Flossie , Cortese Riccardo , Dubuisson Jean , Rice Charles M. , Pietschmann Thomas , Leroux-Roels Geert , Nicosia Alfredo , Meuleman Philip
Published: May 2014

Hepatitis C virus (HCV)-induced endstage liver disease is currently a major indication for liver transplantation. After transplantation the donor liver inevitably becomes infected with the circulating virus. Monoclonal antibodies (mAbs) against the HCV coreceptor scavenger receptor class B type I (SR-BI) inhibit HCV infection of different genotypes, both in cell culture and in humanized mice. Anti-SR-BI mAb therapy is successful even when initiated several days after HCV exposure, supporting its potential applicability to prevent HCV reinfection of liver allografts. However, HCV variants with reduced SR-BI dependency have been described in the literature, which could potentially limit the use of SR-BI targeting therapy. In this study we show, both in a preventative and postexposure setting, that humanized mice infected with HCV variants exhibiting increased

in vitro

resistance to SR-BI-targeting molecules remain responsive to anti-SR-BI mAb therapy

in vivo

. A 2-week antibody therapy readily cleared HCV RNA from the circulation of infected humanized mice. We found no evidence supporting increased SR-BI-receptor dependency of viral particles isolated from humanized mice compared to cell culture-produced virus. However, we observed that, unlike wild-type virus, the

in vitro

infectivity of the resistant variants was inhibited by both human high density lipoprotein (HDL) and very low density lipoprotein (VLDL). The combination of mAb1671 with these lipoproteins further increased the antiviral effect.

Conclusion

: HCV variants that are less dependent on SR-BI

in vitro

can still be efficiently blocked by an anti-SR-BI mAb in humanized mice. Since these variants are also more susceptible to neutralization by anti-HCV envelope antibodies, their chance of emerging during anti-SR-BI therapy is severely reduced. Our data indicate that anti-SR-BI receptor therapy could be an effective way to prevent HCV infection in a liver transplant setting. (Hepatology 2014;60:1508–1518)
Modulation of miR-29 expression by alpha-fetoprotein is linked to the hepatocellular carcinoma epigenome
Authors: Parpart Sonya , Roessler Stephanie , Dong Fei , Rao Vinay , Takai Atsushi , Ji Junfang , Qin Lun-Xiu , Ye Qing-Hai , Jia Hu-Liang , Tang Zhao-You , Wang Xin Wei
Published: May 2014

Globally, hepatocellular carcinoma (HCC) accounts for 70%-85% of primary liver cancers and ranks as the second leading cause of male cancer death. Serum alpha-fetoprotein (AFP), normally highly expressed in the liver only during fetal development, is reactivated in 60% of HCC tumors and associated with poor patient outcome. We hypothesize that AFP+ and AFP− tumors differ biologically. Multivariable analysis in 237 HCC cases demonstrates that AFP level predicts poor survival independent of tumor stage (P < 0.043). Using microarray-based global microRNA (miRNA) profiling, we found that miRNA-29 (miR-29) family members were the most significantly (P < 0.001) down-regulated miRNAs in AFP+ tumors. Consistent with miR-29's role in targeting DNA methyltransferase 3A (DNMT3A), a key enzyme regulating DNA methylation, we found a significant inverse correlation (P < 0.001) between miR-29 and DNMT3A gene expression, suggesting that they might be functionally antagonistic. Moreover, global DNA methylation profiling reveals that AFP+ and AFP− HCC tumors have distinct global DNA methylation patterns and that increased DNA methylation is associated with AFP+ HCC. Experimentally, we found that AFP expression in AFP− HCC cells induces cell proliferation, migration, and invasion. Overexpression of AFP, or conditioned media from AFP+ cells, inhibits miR-29a expression and induces DNMT3A expression in AFP− HCC cells. AFP also inhibited transcription of the miR-29a/b-1 locus, and this effect is mediated through c-MYC binding to the transcript of miR-29a/b-1. Furthermore, AFP expression promotes tumor growth of AFP− HCC cells in nude mice. Conclusion: Tumor biology differs considerably between AFP+ HCC and AFP− HCC; AFP is a functional antagonist of miR-29, which may contribute to global epigenetic alterations and poor prognosis in HCC. (Hepatology 2014;60:872–883)
Bile acids alter male fertility through G-protein-coupled bile acid receptor 1 signaling pathways in mice
Authors: Baptissart Marine , Vega Aurélie , Martinot Emmanuelle , Pommier Aurélien J. , Houten Sander M. , Marceau Geoffroy , de Haze Angélique , Baron Silvère , Schoonjans Kristina , Lobaccaro Jean-Marc A. , Volle David H.
Published: May 2014

Bile acids (BAs) are signaling molecules that are involved in many physiological functions, such as glucose and energy metabolism. These effects are mediated through activation of the nuclear and membrane receptors, farnesoid X receptor (FXR-α) and TGR5 (G-protein-coupled bile acid receptor 1; GPBAR1). Although both receptors are expressed within the testes, the potential effect of BAs on testis physiology and male fertility has not been explored thus far. Here, we demonstrate that mice fed a diet supplemented with cholic acid have reduced fertility subsequent to testicular defects. Initially, germ cell sloughing and rupture of the blood-testis barrier occur and are correlated with decreased protein accumulation of connexin-43 (Cx43) and N-cadherin, whereas at later stages, apoptosis of spermatids is observed. These abnormalities are associated with increased intratesticular BA levels in general and deoxycholic acid, a TGR5 agonist, in particular. We demonstrate here that Tgr5 is expressed within the germ cell lineage, where it represses Cx43 expression through regulation of the transcriptional repressor, T-box transcription factor 2 gene. Consistent with this finding, mice deficient for Tgr5 are protected against the deleterious testicular effects of BA exposure. Conclusions: These data identify the testis as a new target of BAs and emphasize TGR5 as a critical element in testicular pathophysiology. This work may open new perspectives on the potential effect of BAs on testis physiology during liver dysfunction. (Hepatology 2014;60:1054-1065)
A phenomenological study to explore the experiences of Ugandan women that have undergone transvaginal ultrasound
Authors: Mubuuke Aloysius Gonzaga
Published: May 2014

Introduction

Transvaginal ultrasound (TVUS) is an important examination of the female pelvis that involves the transducer being inserted into the vagina to obtain more detailed images of the pelvic organs. Unfortunately, this examination has received mixed experiences from the women who have undergone it. This study set out to explore the lived experiences of Ugandan women who have undergone TVUS.

Methods

It was a phenomenological exploratory study involving 20 women in Uganda that had previously undergone TVUS. Data were collected using in‐depth individual interviews. The responses from the women were audio‐recorded and later transcribed. Thematic analysis was used to interpret and make meaning of the data collected.

Results

Analysis of data revealed mostly negative experiences of the women who were included in this study. Key words from the participating women that illustrated the negative experiences included: fear, vulnerability, guilt, anxiety and embarrassment. It was also observed that these initial negative experiences are likely to reduce the women's acceptability and compliance to TVUS even when it is needed for better clinical management. Data were categorised into the following three thematic areas: (1) broken communication, (2) anxiety and discomfort and (3) cultural influence.

Conclusion

Women in this study portrayed negative experiences of undergoing TVUS. Key suggestions like informed consent are recommended to improve compliance of the women to this type of procedure.
Acute administration of the small‐molecule p75NTRligand does not prevent hippocampal neuron loss or development of spontaneous seizures after pilocarpine‐induced status epilepticus
Authors: Grabenstatter H.L. , Carlsen J. , Raol Y.H. , Yang T. , Hund D. , Cruz Del Angel Y. , White A.M. , Gonzalez M.I. , Longo F.M. , Russek S.J. , Brooks‐Kayal A.R.
Published: May 2014

Neurotrophins, such as brain‐derived neurotrophic factor (BDNF), are initially expressed in a precursor form (e.g., pro‐BDNF) and cleaved to form mature BDNF (mBDNF). After pilocarpine‐induced status epilepticus (SE), increases in neurotrophins regulate a wide variety of cell‐signaling pathways, including prosurvival and cell‐death machinery in a receptor‐specific manner. Pro‐BDNF preferentially binds to the p75 neurotrophin receptor (p75NTR), whereas mBDNF is the major ligand of the tropomyosin‐related kinase receptor. To elucidate a potential role for p75NTRin acute stages of epileptogenesis, rats were injected prior to and at onset of SE with LM11A‐31, a small‐molecule ligand that binds to p75NTRto promote survival signaling and inhibit neuronal cell death. Modulation of early p75NTRsignaling and its effects on electrographic SE, SE‐induced neurodegeneration, and subsequent spontaneous seizures were examined after LM11A‐31 administration. Despite an established neuroprotective effect of LM11A‐31 in several animal models of neurodegenerative disorders (e.g., Alzheimer's disease, traumatic brain injury, and spinal cord injury), high‐dose LM11A‐31 administration prior to and at onset of SE did not reduce the intensity of electrographic SE, prevent SE‐induced neuronal cell injury, or inhibit the progression of epileptogenesis. Further studies are required to understand the role of p75NTRactivation during epileptogenesis and in seizure‐induced cell injury in the hippocampus, among other potential cellular pathologies contributing to the onset of spontaneous seizures. Additional studies utilizing more prolonged treatment with LM11A‐31 are required to reach a definite conclusion on its potential neuroprotective role in epilepsy. © 2014 Wiley Periodicals, Inc.