bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Conductivity Properties of PEDOT Prepared through a Modified LB Film Method
Authors: Zheng Huajing , Jiang Yadong , Xu Jianhua , Yang Yajie
Published: March 2011

Adopting LB film method, an arachidic acid (AA)/PEDOT multilayer LB film was chosen, and polymerized EDOT monomers in hydrophilic group of LB to prepare arachidic acid (AA)/PEDOT multilayer LB film. UV‐Vis, FT‐IR and XPS analyses implied that EDOT was effectively polymerized in film, and thus PEDOT conducting polymer was produced. Analyses of XRR and SIMS indicated that film had a well‐arranged lamella structure, and further research showed that polymerization of EDOT in AA film destroyed the orderliness of the original LB film. This phenomenon could be related to the destructive effect of polymerization on layered structure. We used four‐point probe and semiconductor instrument to study the conductivity property of the film, and observed that the conductivity of AA/PEDOT film had sudden changes with the processing time of changes in effective conduction network. That was caused by "permeability" in conducting channel of multilayer film. The test results also indicated that the conductivity of AA/PEDOT film was obviously better than that of spin‐coating PEDOT/PSS film or that of ODA‐SA/PEDOT‐PSS film, which was due to the higher π structure of PEDOT structure and ordered film structure.
Homology Modeling of Cry1Ac Toxin‐binding Alkaline Phosphatase Receptor from Helicoverpa armigera and Its Functional Interpretation
Authors: Shan Shipinga , Xia Liqiu , Ding Xuezhia , Zhang Youminga , Hu Shengbiaoa , Sun Yunjuna , Yu Ziquana , Han Lizhenb
Published: March 2011

Alkaline phosphatases (ALPs) attached to the midgut membrane with glycosyl phosphotidyl inositol (GPI) have been proposed as the putative Cry1Ac toxin receptor in Helicoverpa armigera. Activated toxins bind to ALP receptors on the brush border membrane vesicle (BBMV) of the midgut epithelium, which activates intracellular oncotic pathways and leads to cell death. However, with the long‐term use of Cry toxin, insects can develop a strong resistance to insecticidal delta‐endotoxins. Although the molecular mechanism of insect resistance has not been fully understood, insects develop resistance to biopesticides due to changes of toxins binding to midgut receptors. So, it is a good idea to investigate the molecular mechanism of insect resistance by analyzing ALP receptor from Helicoverpa armigera (Ha‐ALP). Based on crystal structure of shrimp alkaline phosphatase, the three‐dimensional structure of the Cry1Ac toxin‐binding Ha‐ALP receptor was obtained by homology modeling and the model was further evaluated using PROSA energy and ERRAT. The important role of binding of toxin to GalNAc on Ha‐ALP was discussed in the aspect of Cry1Ac toxicity. Specific recognition sites of the binding of oligosaccharides to Ha‐ALP were predicted. Post‐translational modification of ALP provides insights into the functional properties of ALP and leads to profound understanding of receptor and toxin interactions.
A Calorimetric Study on the Interaction of Zinc and Cadmium Ions with Jack Bean Urease
Authors: Rezaei Behbehani G. , Saboury A. A. , Sabbaghy F.
Published: March 2011

A thermodynamic study on the interaction of Jack bean urease, JBU, with Zn2+ and Cd2+ ions was studied by isothermal titration calorimetry (ITC) at 290, 300 and 310 K in 30 mmol/L Tris buffer solution, pH 7.0. The heats of JBU+Zn2+ and JBU+ 2+ interactions are reported and analyzed in terms of the extended solvation theory. It was indicated that there is a set of 12 identical and non‐interacting binding sites for Zn2+ and Cd2+ ions. The interactions of Zn2+ and Cd2+ ions with JBU are exothermic and both enthalpy and entropy driven. The association equilibrium constants for JBU+Zn2+ complexes are 4118.20, 3354.70 and 2790.62 L·mol−1 at 290, 300 and 310 K respectively. The association equilibrium constants for JBU+Cd2+ interactions are 2831.6 and 2386.28 L· −1 at 300 and 310 K, respectively.
DFT Studies on Detonation Properties, Pyrolysis Mechanism, and Stability of the Nitro and Hydroxyl Derivatives of Benzene
Authors: Du Hongchen , Liu Hui , Liu Yan , Zhang Jianyinga , Wang Fang , Gong Xuedong
Published: March 2011

Ninety‐one nitro and hydroxyl derivatives of benzene were studied at the B3LYP/6‐31G∗︁ level of density functional theory. Detonation properties were calculated using the Kamlet‐Jacobs equation. Three candidates (pentanitrophenol, pentanitrobenzene, and hexanitrobenzene) were recommended as potential high energy density compounds for their perfect detonation performances and reasonable stability. The pyrolysis mechanism was studied by analyzing the bond dissociation energy (BDE) and the activation energy (Ea) of hydrogen transfer (H–T) reaction for those with adjacent nitro and hydroxyl groups. The results show that Ea is much lower than BDEs of all bonds, so when there are adjacent nitro and hydroxyl groups in a molecule, the stability of the compound will decrease and the pyrolysis will be initiated by the H–T process. Otherwise, the pyrolysis will start from the breaking of the weakest C–NO2 bond, and only under such condition, the Mulliken population or BDE of the C–NO2 bond can be used to assess the relative stability of the compound.
Preparation, Characterization and Non‐isothermal Kinetics of the Dehydration Process of [Sm(p‐MOBA)3bath]2·4H2O
Authors: Wang Juanfen , Liu Xin , Tian Liang , Zhang Dahai , Wu Kezhong , Zhang Jianjun
Published: March 2011

The new complex of [Sm(p‐MOBA)3bath]2·4H2O (p‐MOBA, p‐methoxybenzoate; bath, 4,7‐diphenyl‐1,10‐phenanthroline) was synthesized and characterized by elemental analysis, molar conductance, IR, UV and XRD patterns. The thermal decomposition of the complex was studied under the non‐isothermal condition by TG‐DTG and IR techniques. The most probable mechanism function of the dehydration process was obtained from the analysis of DSC curves of the complex employing the double extrapolated method on the basis of integral isoconversional non‐linear (NL‐INT) and Tang‐Wanjun integral equations. The integral function of the mechanism was [1− (1−α)1/2]1/2 and the corresponding kinetic parameters (activation energy E and the pre‐exponential factor A) were obtained.
Simultaneous Al2O3 Doping and Sulfation in Hierarchically Porous ZrO2 Solid Acids by an One‐pot Synthesis for Enhanced Recycling Catalytic Performances
Authors: Wang Nan , Chen Yu , Ye Zhengqing , Chen Hangrong , Shi Jianlin
Published: March 2011

Alumina doping and sulfation in hierarchically porous zirconia solid acids have been achieved simultaneously via one‐pot and bi‐surfactant‐assisted self‐assembly process, using aluminum sulfate as both Al and SO42− sources. The prepared composite solid acids showed much enhanced acidity and recycling catalytic activity for an esterification reaction compared with sulfated zirconia without alumina doping and Al‐doped sulfated zirconia without hierarchically porous structure.
Cationic Micelle‐catalyzed Ring‐Opening Reactions of Aziridines with Thiols in Water
Authors: Yang Min , Yang Qin , Chen Puqing , Peng Yiyuan
Published: March 2011

An efficient and practical method is described for the ring‐opening reactions of N‐tosylaziridines with various thiols in water under mild conditions. Various surfactants have been evaluated to optimize the reactions. Under optimal conditions, these reactions gave rise to the corresponding β‐amino sulfides in good to excellent yields.
Design, Synthesis and Evaluation of Substituted N‐(3‐Arylpropyl)‐9,10‐dihydro‐9‐oxoacridine‐4‐carboxamides as Potent MDR Reversal Agents in Cancer
Authors: Velingkar V. S. , Dandekar V. D.
Published: March 2011

A novel class of molecules with structure N‐(3‐arylpropyl)‐9,10‐dihydro‐9‐oxoacridine‐4‐carboxamides (20–29) were designed by generating a pharmacophore for potent MDR reversal activity using phase drug design software. The designed molecules were synthesized by a novel synthesis route and evaluated for their inhibitory effects on the transport activity of P‐glycoprotein (P‐gp) by standard Hoechst 33342 assay method. Based on the pIC50 values of ten title compounds screened, three compounds exhibited better activity as compared to Verapamil used as standard.
Synthesis and in vitro Fungicidal Activity of a Series of Novel N‐(Heterocycly)phthalimides
Authors: Ban Shurong , Chen Wenbin , Xi Zhen
Published: March 2011

A series of novel phthalimides was prepared and tested for antifungal activity in vitro against seven phytopathogenic fungi:Rhizoctonia solani, Fusarium oxysporum f.sp. cucumerinum Owen., Botrytis cinerea, Fulvia fulva, Sclerotinia sclerotiorum de Bary, Phytophthora capsici, Botryosphaeria berengeriama. The results showed that those compounds holding the structure of 6‐methylpyridin‐2‐yl exhibited good activity against Phytophthora capsici and Botrytis cinerea.
Synthesis and Fungicidal Activity of 2‐Acetyl‐6‐(un)substituted‐1H‐benzimidazole Oxime‐ethers
Authors: Jiang Lin , Wang Haibo , Mu Wei , Ji Zengchen , Cao Peng
Published: March 2011

Twelve novel compounds of 2‐acetyl‐1H‐benzimidazole oxime‐ethers and 2‐acetyl‐6‐chloro‐1H‐benzimidazole oxime‐ethers were synthesized with o‐phenylenediamine (or 4‐chloro‐o‐phenylenediamine), 2‐hydroxypropyl acid, alkoxy (or benzyloxy) amines hydrochloride as starting materials. The structures of the target compounds were characterized by IR, 1H NMR spectra and elemental analyses. The in vitro fungicidal activities against Botrytis cinerea Pers and Alternaria alternata were also evaluated by mycelium growth rate method. The results indicate that the compounds 3b, 3c, 3f, 3g and 3h exhibit good activities against Botrytis cinerea Pers, while 3b and 3f possess excellent activities against Alternaria alternate, and their fungicidal activities are all higher than that of carbendazim.
Sensitive Spectrofluorimetric Method of Analysis for Gabapentin in Pure and Pharmaceutical Preparations
Authors: Ulu Sevgi Tatar , Kel Elif
Published: March 2011

Highly sensitive spectrofluorimetric method was developed and validated for the determination of gabapentin in pure and pharmaceutical preparations. The method was based on nucleophilic substitution reaction of gabapentin with 4‐fluoro‐7‐nitrobenzofurazan (NBD‐F) in an alkaline medium (pH 9.5) to form a highly fluorescent derivative that was measured at 521 nm after excitation at 458 nm. The factors affecting the reaction was carefully studied and optimized. The method was successfully validated for linearity, limit of detection, limit of quantification, accuracy, precision, robustness and specificity. Under the optimized conditions, linear relationship with good correlation coefficient (0.9998) was found between the relative fluorescence intensity and gabapentin concentration in the range of 10–100 ng·mL−1. The limit of detection and limit of quantification were 0.43 and 1.30 ng·mL−1, respectively. The proposed method was successfully applied to the determination of gabapentin in its pharmaceutical capsules. The results obtained by the proposed method were comparable with those obtained by the official method. Statistical comparison by t‐ and F‐ tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level.
Electrochemiluminescent Detection Method for Glyphosate in Soybean on Carbon Fiber‐ionic Liquid Paste Electrode
Authors: Cai Qihong , Chen Xiaoping , Qiu Bin , Lin Zhenyu
Published: March 2011

A carbon fiber paste electrode using ionic liquid as the binder (CFILE) was fabricated. The electrochemical characteristics of the electrode was examined in ferro‐/ferricyanide solution and showed better conductivity and reversibility when compared with graphite paste‐ionic liquid electrode (GPILE) and a little better than that on the carbon nanotube paste‐ionic liquid electrode (CNTILE). Glyphosate (GLY), a pesticide, exhibited excellent catalysis to the oxidation of Ru(bpy)2+3 on CFILE and brought an obvious enhancement to the electrochemiluminescence (ECL) intensity of Ru(bpy)2+3. Based on the catalytic ability of GLY, a simple ECL method for GLY detection had been established. Under optimum conditions, the enhanced ECL intensities were found to had linearly respond to the GLY concentration between 3.0×10−7 and 3.0×10−5 mol/L, and the detection limit (S/N=3) was 2.0×10−7 mol/L. The electrode also showed excellent sensitivity in detecting GLY‐spiked soybean samples. The linear range for GLY in soybean samples was 1.0×10−6–4.0×10−5 mol/L and the detection limit was 5.0×10−7 mol/L, equal to 8.45 µg GLY in per gram of soybean. The detection limit in soybean sample was lower than the USA, EU regulation and so on. If the method is coupled with the separation technology, it can be applied to detect the GLY in the contaminated samples.
Unexpected Adsorption Capacity of Ca‐deficient Hydroxyapatite in Oil/water System
Authors: Jin Hui , Kuang Chunxiang
Published: March 2011

Symmetrical diynes were synthesized by ligand‐free copper‐catalyzed homocoupling reaction of 1,1‐dibromo‐1‐alkenes using a DBU/DMSO system at room temperature in good to excellent yields dot.−1.
Undocumented alcoholism and its correlation with tobacco and illegal drug use in advanced cancer patients
Authors: Dev Rony , Parsons Henrique A. , Palla Shana , Palmer J. Lynn , Del Fabbro Egidio , Bruera Eduardo
Published: March 2011

BACKGROUND:

The objectives of this retrospective study were to determine the frequency of undiagnosed alcoholism among patients with advanced cancer who were referred to palliative care and to explore its correlation with alcoholism, tobacco abuse, and use of illegal drugs.

METHODS:

The authors reviewed 665 consecutive charts and identified 598 patients (90%) who completed a screening survey that was designed to identify alcoholism, the Cut Down, Annoyed, Guilty, Eye Opener (CAGE) questionnaire, including 100 consecutive patients who had CAGE‐positive and CAGE‐negative results. Data on tobacco and illegal drug use, the Edmonton Symptom Assessment Scale, and the morphine equivalent daily dose were collected.

RESULTS:

The frequency of CAGE‐positive results in this palliative care population was 100 of 598 patients (17%). Only 13 of 100 patients (13%) in that CAGE‐positive group had been identified as alcoholics before their palliative care consultation. Compared with CAGE‐negative patients, CAGE‐positive patients were younger (aged 58.6 years vs 61.3 years; P = .07), predominantly men (68 of 100 patients vs 51 of 100 patients; P = .021), more likely to have a history of tobacco use (86 of 100 patients vs 48 of 100 patients; P < .001), more likely to be actively using nicotine (33 of 100 patients vs 9 of 100 patients; P = .02), and more likely to have a history of illegal recreational drug use (17 of 100 patients vs 1 of 100 patients; P < .001). Pain and dyspnea were worse in patients who had a history of nicotine use. Both CAGE‐positive patients and patients who had a history of tobacco use more frequently were receiving strong opioids at the time of their palliative care consultation.

CONCLUSIONS:

The current findings suggested that alcoholism is highly prevalent and frequently under diagnosed in patients with advanced cancer. CAGE‐positive patients were more likely to have a history of, or to actively engage in, smoking and illegal recreational drug use, placing them at risk for inappropriate opioid escalation and abuse. Cancer 2011;. © 2011 American Cancer Society.
Sphincter‐sparing local excision and hypofractionated radiation therapy for anorectal melanoma
Authors: Kelly Patrick , Zagars Gunar K. , Cormier Jancie N. , Ross Merrick I. , Guadagnolo B. Ashleigh
Published: March 2011

BACKGROUND:

Anorectal melanoma is a rare disease with a poor prognosis. Because survival is determined by distant failure, many centers have adopted sphincter‐sparing excision for primary tumor control. However, this approach is associated with high rates of local failure (∼50%). In this study, the authors report their 20‐year experience with sphincter‐sparing excision combined with radiation therapy (RT) for the treatment of localized anorectal melanoma.

METHODS:

The authors reviewed the records of 54 patients with localized anorectal melanoma who were treated at the University of Texas MD Anderson Cancer Center from 1989 to 2008. All patients underwent definitive local excision with or without sentinel lymph node biopsy or lymph node dissection. RT (25‐36 grays in 5‐6 fractions) was delivered to extended fields that targeted the primary site and draining pelvic/inguinal lymphatics in 39 patients and to limited fields that targeted only the primary site in 15 patients.

RESULTS:

The 5‐year rates of local control (LC), lymph node control (NC), and sphincter preservation were 82%, 88%, and 96%, respectively. However, because of the high rate of distant metastasis, the overall survival (OS) rate at 5 years was only 30%. Although there were no significant differences in LC, NC, or OS based on RT field extent, patients who received extended‐field RT had higher rates of lymphedema than patients who received limited‐field RT.

CONCLUSIONS:

The current results indicated that combined sphincter‐sparing local excision and RT is a well tolerated approach that provides effective LC for patients with anorectal melanoma. Inclusion of the inguinal lymph node basins in the RT fields did not improve outcomes and was associated with an increased risk of lymphedema. Cancer 2011;. © 2011 American Cancer Society.
Treatment‐related mortality in children with acute lymphoblastic leukemia in Central America
Authors: Gupta Sumit , Antillon Federico A. , Bonilla Miguel , Fu Ligia , Howard Scott C. , Ribeiro Raul C. , Sung Lillian
Published: March 2011

BACKGROUND:

The objectives of this study were to describe the incidence, timing, and predictors of treatment‐related mortality (TRM) among children with acute lymphoblastic leukemia (ALL) in El Salvador, Guatemala, and Honduras.

METHODS:

Patients aged <20 years who were diagnosed with ALL between January 2000 and March 2008, who received treatment in any of the 3 countries, and who started induction chemotherapy were included in the study. Almost all patients were treated on the El Salvador‐Guatemala‐Honduras II protocol, which was based on the St. Jude Total XIII and XV protocols. Biologic, socioeconomic, and nutritional variables were examined as predictors of TRM.

RESULTS:

Of 1670 patients, TRM occurred as a first event in 156 children (9.3%); TRM occurred during remission induction therapy in 92 of 156 children (59%), between remission induction and maintenance therapy in 27 of 156 children (17%), and during maintenance therapy in 37 of 156 children (24%). Although the TRM rate decreased in patients who were diagnosed after July 1, 2004 (11.2% vs 7.9%; P = .02), the rate of induction death did not change (5.2% vs 5.8%; P = .58). Independent predictors of induction death included higher risk ALL (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.03‐3.27; P = .04), lower initial platelet counts (OR per 10 × 109/L, 0.94; 95% CI, 0.89‐0.98; P = .005), and longer travel time to the clinic (OR, 1.06 per hour; 95% CI, 1.01‐1.14; P = .03).

CONCLUSIONS:

In Central America, TRM remains an important cause of treatment failure in children with ALL. A large proportion of TRM occurs in maintenance, although this proportion has decreased over time. Supportive care interventions should especially target children who present with low platelet counts. Further study on transfusion ability and the location of induction deaths is required. Cancer 2011;. © 2011 American Cancer Society.
Ecological Viability or Liability? Insurance System Responses to Climate Risk
Authors: Phelan Liam , Taplin Ros , Henderson‐Sellers Ann , Albrecht Glenn
Published: March 2011

Climate change is a phenomenon of the Earth system, which is characterized by thresholds and non‐linear change. This analysis considers the adequacy of insurance (in its broadest sense) responses to climate risk. This paper provides novel critiques of insurance system responses to climate change and of the attendant political economy perspective on the relationship between insurance and climate change. A complex adaptive systems (CAS) analysis suggests that ecologically effective (i.e. strong) mitigation is the only viable approach to manage medium‐ and long‐term climate risk – for the insurance system itself and for human societies more widely. In contrast, we find that even the most substantial insurance system responses to date are generally adaptive and weakly mitigative. This analysis extends an earlier political economy perspective that explains the limitations of insurance system responses to climate change, but provides little guidance to the ecological implications of such responses. As such, this paper raises questions about the ongoing viability of the insurance system, and hence about the many aspects of human societies globally reliant on the insurance system as their primary risk governance tool. We conclude that the CAS approach provides new insights, which could prompt insurance system evolution in support of effective climate risk governance. Copyright © 2011 John Wiley & Sons, Ltd and ERP Environment.
A Spirocyclic Borate and a Dihydroborate Derived from the 1,2‐Diselenolato‐1,2‐dicarba‐closo‐dodecaborane(12) Dianion [1,2‐(1,2‐C2B10H10)Se2]2–: Structures, NMR Spectroscopy, and DFT Calculations
Authors: Wrackmeyer Bernd , Klimkina Elena V. , Milius Wolfgang
Published: March 2011

The reaction of the diselenolato‐1,2‐dicarba‐closo‐dodecaborane(12) dianion with BF3–OEt2affords selectively a spirocyclic bis(1,2‐dicarba‐closo‐dodecaborane‐1,2‐diselena)borate, whereas the analogous reaction with boron trichloride leads mainly to 1,2‐bis(ethylseleno)‐1,2‐dicarba‐closo‐dodecaborane(12) through ether cleavage. The spirocyclic borate reacts with methanol by cleavage of both Se–B and Se–C bonds. With borane in THF (BH3/THF) and also with LiBH4exchange reactions take place, which afford the 1,2‐dicarba‐closo‐dodecaborane‐1,2‐diselenadihydroborate. The molecular structures of both borates as tetrabutylammonium salts were determined by X‐ray analysis. In solution, the borates were characterized by multinuclear magnetic resonance spectroscopy (1H,11B,13C,77Se). The gas‐phase geometries of the borate anions were optimized [RB3LYP/6‐3111+G(d,p) level of theory], and the NMR spectroscopic parameters (chemical shifts and coupling constants) were calculated.
Hydrogen bonding networks in [(η6‐arene)Cr(CO)3] complexes
Authors: Murugesapandian Balasubramanian , Roesky Peter W.
Published: March 2011

The four different [(η6‐arene)chromium tricarbonyl] complexes [(η6‐C6H5CH2COOH) Cr(CO)3], [{η6‐(1,2‐C6H4(NH2)COOEt)}Cr(CO)3], [η6 ‐{2,6‐C6H4(i‐Pr)2NH2}Cr(CO)3], and [{η6 ‐(1,4‐C6H4(NH2)CH3)}Cr(CO)3] were synthesized and structurally characterized by single crystal X‐ray diffraction. All compounds form hydrogen bonds in the solid state, leading to dimeric or polymeric networks. The hydrogen bonds are an essential part of the network. The connectivity is influenced by the groups on which the protons are bound (COOH vs. NH2) and by the steric demand of the ligand. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:294–300, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20679
Time is up: increasing shadow price of time in primary‐care office visits
Authors: Tai‐Seale Ming , McGuire Thomas
Published: March 2011

A physician's own time is a scarce resource in primary care, and the physician must constantly evaluate the gain from spending more time with the current patient against moving to address the health‐care needs of the next. We formulate and test two alternative hypotheses. The first hypothesis is based on the premise that with time so scarce, physicians equalize the marginal value of time across patients. The second, alternative hypothesis states that physicians allocate the same time to each patient, regardless of how much the patient benefits from the time at the margin. For our empirical work, we examine the presence of a sharply increasing subjective shadow price of time around the ‘target’ time using video recordings of 385 visits by elderly patients to their primary care physician. We structure the data at the ‘topic’ level and find evidence consistent with the alternative hypothesis. Specifically, time elapsed within a visit is a very strong determinant of the current topic being the ‘last topic’. This finding implies the physician's shadow price of time is rising during the course of a visit. We consider whether dislodging a target‐time mentality from physicians (and patients) might contribute to more productive primary care practice. Copyright © 2011 John Wiley & Sons, Ltd.
Free convection of composite porous medium in a vertical channel
Authors: Umavathi J. C.
Published: March 2011

A fully developed free convection flow of immiscible fluids in a vertical channel filled with a porous medium is analyzed in the presence of source/sink. The flow is modeled using the Darcy–Brinkman–Forchheimer equation model. The viscous and Darcy dissipation terms are included in the energy equation. The channel walls are maintained at two different constant temperatures. The transport properties of both fluids are assumed to be constant. Continuous conditions for velocity, temperature, shear stress, and heat flux of both fluids at the interface are employed. The resulting coupled nonlinear equations are solved analytically using regular perturbation method and numerically using finite difference method. The velocity and temperature profiles are obtained in terms of porous parameter, Grashof number, viscosity ratio, width ratio, conductivity ratio, and heat generation or heat absorption coefficient. It is found that the presence of porous matrix and heat absorption reduces the flow field. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20340
Heat transfer characteristics of a reservoir embedded loop heat pipe (Heat transfer characteristics of a deployable radiator for use on the ETS‐VIII satellite while in orbit)
Authors: Ishikawa Hiroaki , Nomura Takehide , Saito Yasuyuki , Kawasaki Haruo , Okamoto Atsushi , Hatakenaka Ryuta
Published: March 2011

As heat generation in satellites increases, ensuring that they are provided with sufficient radiator panel area is an important problem. Deployable radiators, with radiator panels that are deployed post‐launch in space to increase the satellite's effective radiator panel area of the satellite, are becoming an important thermal control technology. A reservoir embedded loop heat pipe (RELHP) is used in deployable radiators as a heat transport device. A deployable radiator of this type was mounted on the ETS‐VIII satellite, which was launched on December 18, 2006 and injected into a geostationary orbit. The satellite is still operating without any significant issues over two years later. This paper investigates the heat transport characteristics of an RELHP system used in a deployable radiator in a geostationary orbital environment. This system can be successfully started up in a micro gravity environment. We also found that the sub‐cooling region is shorter in a micro gravity environment than in a terrestrial gravity environment, because there is less heat leakage into the reservoir in a micro gravity environment. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20346
The effect of a metal plate barrier with holes blocking channel in the forced convection of rectangular modules
Authors: Fujii Masao , Sawai Toru
Published: March 2011

The experimental work reported here has provided an analysis of the effect of a perforated barrier, fully spanning the flow passage upstream of a pair of modules in a duct, on heat transfer and pressure drop characteristics of heated, rectangular modules that are commonly encountered in electronic equipment.

The barrier has been shown to be an effective means towards providing heat transfer enhancement. Heat transfer was increased with increasing barrier hole diameter d, and decreasing barrier porosity σ and module‐barrier distance L. The enhancing effect of the barrier was found to change dramatically at L/d = 3.5 and 18. Experimental data on heat transfer coefficients were correlated as a function of L/d, σ, and Reynolds number.

The pressure loss coefficient of the barrier is influenced by porosity σ, and is insensitive to the other factors experimentally investigated. The average pressure loss coefficient was correlated as a function of σ. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20348
Emerging topics in human tumor virology
Authors: Hoppe‐Seyler Felix , Hoppe‐Seyler Karin
Published: March 2011

After a long period of scepticism and disbelief, tumor viruses are today recognized as a significant cancer risk factor for humans. Much has been learned about the viral transforming mechanisms and prophylactic vaccines have been developed against 2 major tumor viruses, HBV and HPV. Yet, many important issues of tumor virology remain unresolved and exciting new ones are emerging from recent discoveries. They define future research directions for the field and include (i) novel strategies for tumor virus hunting, (ii) tumor viruses as experimental tools to study human carcinogenesis, (iii) the interplay between viruses and the world of small noncoding RNAs, (iv) epigenetic interactions between tumor viruses and the host cell, (v) the role of virus/virus interactions for viral carcinogenesis and (vi) novel strategies for prevention and therapy of virus‐associated cancers. These topics are discussed by summarizing recent developments, pointing out unresolved issues and suggesting possible strategies for their solution.
VEGF directly suppresses activation of T cells from ovarian cancer patients and healthy individuals via VEGF receptor Type 2
Authors: Ziogas Apostolos C. , Gavalas Nikos G. , Tsiatas Marinos , Tsitsilonis Ourania , Politi Ekaterini , Terpos Evangelos , Rodolakis Alexandros , Vlahos George , Thomakos Nikolaos , Haidopoulos Dimitrios , Antsaklis Aristidis , Dimopoulos Meletios A. , Bamias Aristotle
Published: March 2011

The role of vascular endothelial growth factor (VEGF) in tumor angiogenesis is well characterized; nevertheless, it is also a key element in promoting tumor evasion of the immune system by downregulating dendritic cell maturation and thus T cell activation. We sought to investigate the possible direct effect of VEGF on T cell activation and through which type of VEGF receptor (VEGFR) it exerts this effect. Circulating T cells from healthy donors and ovarian cancer patients were expanded in cultures with anti‐CD3 and IL‐2 with or without VEGF for 14 days, and the number of T cells was assessed. Cultured T cells were also tested for their cytotoxic activity in a standard 4‐hr 51Cr‐release assay, and the expression of VEGFRs 1, 2 and 3 was assayed by flow cytometry, immunocytochemistry and Western blotting. To assess the ability of activated T cells to secrete VEGF, levels in culture supernatants were measured by enzyme linked immunosorbent assay. The addition of VEGF in cultures significantly reduced T cell proliferation in a dose‐dependent manner. Protein expression studies demonstrated that CD3+ T cells express VEGFR‐2 on their surface upon activation. Experiments with anti‐VEGFR‐2 antibodies showed that the direct suppressive effect of VEGF on T cell proliferation is mediated by VEGFR‐2. We also showed that VEGF significantly reduced the cytotoxic activity of T cells and that activated T cells secrete VEGF in the culture environment. Overall, our study shows that T cells secret VEGF and expresses VEGFR‐2 upon activation. VEGF directly suppresses T cell activation via VEGF receptor type 2.
LINE‐1 hypomethylation is associated with bladder cancer risk among nonsmoking Chinese
Authors: Cash Haley L. , Tao Li , Yuan Jian‐Min , Marsit Carmen J. , Houseman E. Andres , Xiang Yong‐Bing , Gao Yu‐Tang , Nelson Heather H. , Kelsey Karl T.
Published: March 2011

Reduced levels of global DNA methylation, assessed in peripheral blood, have been associated with bladder cancer risk in European and American populations. Similar data are lacking in Asian populations where genetic differences, lifestyle factors and different environmental exposures may affect DNA methylation and its risk relationship with bladder cancer. The association between global DNA methylation measured at long interspersed nuclear element (LINE‐1) repeat regions through bisulfite pyrosequencing in lymphocyte DNA and bladder cancer risk was examined in a case–control study of 510 bladder cancer patients and 528 healthy control subjects in Shanghai, China. In an initial analysis restricted to control subjects, LINE‐1 methylation was elevated among men, those who frequently consumed cruciferous vegetables and those with a null genotype for either glutathione S‐transferase M1 (GSTM1) or GSTT1. In contrast, reduced LINE‐1 methylation was found in current smokers with a high‐cytochrome P450 1A2 (CYP1A2) phenotype index. In a case–control analysis, there was no significant association of LINE‐1 methylation with case status, although reduced LINE‐1 methylation was associated with increased risk of bladder cancer among never smokers (p for trend = 0.03); analysis by tertile revealed odds ratios (ORs) of 1.91 (lowest tertile; 95% CI = 1.17–3.13) and 1.34 (middle tertile; 95% CI = 0.79–2.28) when compared with the highest tertile. This association was strongest among nonsmokers null for either the GSTM1 or GSTT1 genotype (p for trend = 0.006). Further research is needed to understand the relationships between methyl group availability and LINE‐1 methylation in relation to bladder cancer risk.
Side‐necked turtle (Pleurodira, Chelonia, reptilia) hemoglobin: cDNA‐derived primary structures and X‐ray crystal structures of Hb A
Authors: Hasegawa Tomokazu , Shishikura Fumio , Kuwada Takao
Published: March 2011

Red blood cells of yellow‐spotted river turtles (Podocnemis unifilis, Pleurodira, Chelonia, REPTILIA) have two hemoglobin (Hb) components, Hb A and Hb D. We purified the hemoglobin component homologous to amniote (reptiles, birds, and mammals) adult Hb A which comprises two identical αA‐globin polypeptides and two identical β‐globin polypeptides. To establish the crystal structure of Podocnemis Hb A, we first determined the globin primary structures using cDNA nucleotide sequencing with the assistance of protein sequencing. The purified Podocnemis Hb A produced a different form of crystal for each of the two different buffer systems used: form A, tetragonal crystals (space group, P41212), produced under neutral pH (pH 7–8) conditions; and form B, hexagonal crystals (space group, P6122), produced under high alkaline pH (pH 11–13) conditions. Single crystals of the two forms were examined by Raman microscopy with an excitation of 532 nm, indicating their structural differences. The crystal structures of the two forms were constructed by X‐ray crystallographic diffraction at a resolution of 2.20 Å for form A and 2.35 Å for form B. The differences of the tertiary and quaternary structures of the two forms were marginal; however, one clear difference was found in helix structure. When comparing Podocnemis Hb A with Hb A from specimens in other taxa, such as Anser
indicus (birds) and Homo
sapiens (mammals) by SHELXPRO, the root mean square deviation (RMSD) between the corresponding Cα atoms of the two globins does not exceed 2.0 Å. These low values indicate the crystal structures resemble each other. Our data on X‐ray crystal structures and Raman spectra not only reveal the first findings on the two crystal forms of Podocnemis
unifilis Hb A but also provide the first refined models for reptilian adult Hb A. © 2011 IUBMB IUBMB Life, 63(3): 188–196, 2011
Structural properties of 2/2 hemoglobins: The group III protein from Helicobacter hepaticus
Authors: Nothnagel Henry J. , Winer Benjamin Y. , Vuletich David A. , Pond Matthew P. , Lecomte Juliette T. J.
Published: March 2011

The ε‐proteobacterium Helicobacter hepaticus (Hh) contains a gene coding for a hemoglobin (Hb). The protein belongs to the 2/2 Hb lineage and is representative of group III, a set of Hbs about which little is known. An expression and purification procedure was developed for Hh Hb. Electronic absorption and nuclear magnetic resonance (NMR) spectra were used to characterize ligation states of the ferric and ferrous protein. The pKa of the acid/alkaline transition of ferric Hh Hb was 7.3, an unusually low value. NMR analysis of the cyanomet complex showed the orientation of the heme group to be reversed when compared with most group I and group II 2/2 Hbs. Ferrous Hh Hb formed a stable cyanide complex that yielded NMR spectra similar to those of the carbonmonoxy complex. All forms of Hh Hb were self‐associated at NMR concentrations. Comparison was made to the related Campylobacter jejuni 2/2 Hb (Ctb), and the amino acid conservation pattern of group III was reinspected to help in the generalization of structure–function relationships. © 2011 IUBMB IUBMB Life, 63(3): 197–205, 2011
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii
Authors: Boechi Leonardo , Martì Marcelo A. , Vergara Alessandro , Sica Filomena , Mazzarella Lelio , Estrin Dario A. , Merlino Antonello
Published: March 2011

The Root effect describes the drastic drop of oxygen affinity and loss of cooperativity at acidic pH expressed in the hemoglobins (Hb) of certain fish. The comparison between the deoxy structures of the Root effect Hb from the Antarctic fish Trematomus bernacchii (HbTb) at different pHs (pH = 6.2 and pH = 8.4) shows that the most significant differences are localized at the CDα region, where a salt bridge between Asp48 and His55 breaks during the low‐to‐high pH transition. In order to shed light on the relationship between pH, CDα loop structure and dynamics, and oxygen access to the active site in the alpha chain of HbTb, different computer simulation techniques were performed. Our results highlight the importance of the protonation of His55 in regulating oxygen access, underscoring its pivotal role in the structural and functional properties of HbTb. These data provide further support to the hypothesis that this residue might contribute to the release of Root protons in HbTb and underline the fact that an efficient transport of molecular oxygen in Hbs relies on a subtle balance of tertiary structure and protein conformational flexibility. © 2011 IUBMB IUBMB Life, 63(3): 175–182, 2011
Structural and functional properties of class 1 plant hemoglobins
Authors: Igamberdiev Abir U. , Bykova Natalia V. , Hill Robert D.
Published: March 2011

Nonsymbiotic class 1 plant hemoglobins are induced under hypoxia. Structurally they are protein dimers consisting of two identical subunits, each containing heme iron in a weak hexacoordinate state. The weak hexacoordination of heme‐iron binding to the distal histidine results in an extremely high avidity to oxygen, with a dissociation constant in the nanomolar range. This low dissociation constant is due to rapid oxygen binding resulting in protein conformational changes that slow dissociation from the heme site. Class 1 hemoglobins are characterized by an increased rate of Fe3+ reduction which is likely mediated by cysteine residue. This cysteine can form a reversible covalent bond between two monomers as shown by mass spectrometry analysis and, in addition to its structural role, prevents the molecule from autoxidation. The structural properties of class 1 hemoglobins allow them to serve as soluble electron transport proteins in the enzymatic system scavenging nitric oxide produced in low oxygen via reduction of nitrite. During oxygenation of nitric oxide to nitrate, oxidized ferric hemoglobin is formed (methemoglobin), which can be reduced by an associated reductase. The identified candidate for this reduction is monodehydroascorbate reductase. It is suggested that hemoglobin functions as a terminal electron acceptor during the hypoxic turnover of nitrogen, the process aided by its extremely high affinity for oxygen. © 2011 IUBMB IUBMB Life, 63(3): 146–152, 2011
Structure and dynamics of Antarctic fish neuroglobin assessed by computer simulations
Authors: Boron Ignacio , Russo Roberta , Boechi Leonardo , Cheng C.‐H. Christina , di Prisco Guido , Estrin Darío A. , Verde Cinzia , Nadra Alejandro D.
Published: March 2011

Neuroglobin (Ngb) is a heme protein, highly conserved along evolution, predominantly found in the nervous system. It is upregulated by hypoxia and ischemia and may have a neuroprotective role under hypoxic stress. Although many other roles have been proposed, the physiological function is still unclear. Antarctic icefishes lack hemoglobin and some species also lack myoglobin, but all have Ngb and thus may help the elucidation of Ngb function. We present the first theoretically derived structure of fish Ngb and describe its behavior using molecular dynamics simulations. Specifically, we sequenced and analyzed Ngbs from a colorless‐blooded Antarctic icefish species Chaenocephalus aceratus and a related red‐blooded species (Dissostichus mawsoni). Both fish Ngbs are 6‐coordinated but have some peculiarities that differentiate them from mammalian counterparts: they have extensions in the N and C termini that can interact with the EF loop, and a gap in the alignment that changes the CD‐region structure/dynamics that has been found to play a key role in human neuroglobin. Our results suggest that a single mutation between both fish Ngbs is responsible for significant difference in the behavior of the proteins. The functional role of these characteristics is discussed. © 2011 IUBMB IUBMB Life, 63(3): 206–213, 2011
Hutchinson-gilford progeria is a skeletal dysplasia
Authors: Gordon Catherine M , Gordon Leslie B , Snyder Brian D , Nazarian Ara , Quinn Nicolle , Huh Susanna , Giobbie-Hurder Anita , Neuberg Donna , Cleveland Robert , Kleinman Monica , Miller David T , Kieran Mark W
Published: March 2011

Hutchinson-Gilford progeria syndrome (HGPS) is a rare segmental premature aging disorder that affects bone and body composition, among other tissues. We sought to determine whether bone density and structural geometry are altered in children with HGPS and whether relationships exist among these parameters and measures of skeletal anthropometry, body composition, and nutrition. We prospectively enrolled 26 children with HGPS (ages 3.1 to 16.2 years). Outcomes included anthropometric data; bone age; areal bone mineral density (aBMD) and body composition by dual-energy X-ray absorptiometry (DXA); volumetric bone mineral density (vBMD), strength-strain index (SSI), and bone structural rigidity calculated from radial transaxial peripheral quantitative computed tomographic (pQCT) images; serum bone biomarkers and hormonal measures; and nutrition assessments. Children with HGPS had low axial aBMD Z-scores by DXA, which improved after adjustment for height age, whereas differences in radial vBMD by pQCT were less striking. However, pQCT revealed distinct abnormalities in both novel measures of bone structural geometry and skeletal strength at the radius compared with healthy controls. Dietary intake was adequate, confirming that HGPS does not represent a model of malnutrition-induced bone loss. Taken together, these findings suggest that the phenotype of HGPS represents a unique skeletal dysplasia. © 2011 American Society for Bone and Mineral Research.
Protein folding and the order/disorder paradox
Authors: Kulkarni Prakash , Rajagopalan Krithika , Yeater David , Getzenberg Robert H.
Published: March 2011

Most proteins encoded by the nuclear genome are synthesized in the cytoplasm and fold into precise 3D structures. During synthesis, the nascent polypeptide begins to fold as it traverses the large subunit of the ribosome and is assisted by molecular chaperones in attaining its precise folded/highly ordered state efficiently and in a biologically relevant timescale. Proteins that are misfolded are culled, re‐routed, and marked by mechanisms such as ubiquitinylation for degradation ensuring strict quality control (QC). In addition to the highly ordered “globular” proteins, emerging evidence indicates that a large fraction of the proteome also comprises the so‐called “Intrinsically Disordered Proteins” (IDPs). IDPs are proteins that lack rigid 3D structures and instead, exist as dynamic ensembles. The dynamic structures in the IDPs have many similarities with “normal” globular proteins such as the native (ordered), and non‐native (molten globule, pre‐molten globule, and coil‐like) states seen during folding of “normal” globular proteins. However, unlike the case of the nascent globular proteins, IDPs evade being detected as “misfolded” and degraded by the cell's QC system. We refer to this paradox as the order/disorder paradox and postulate that the IDPs capitalize on their intrinsic promiscuity and ability to undergo disorder‐to‐order transitions upon binding to biological targets (coupled folding and binding) to escape the cell's surveillance machinery. Understanding the mechanism by which the IDPs evade the quality check has wide implications from protein folding to disease biology since the aggregation of misfolded proteins underlies several debilitating illnesses such as many neurodegenerative diseases and cancer. J. Cell. Biochem. 112: 1949–1952, 2011. © 2011 Wiley‐Liss, Inc.
Survival, development, and gonadal differentiation in Rana dalmatina chronically exposed to chlorpyrifos
Authors: Bernabò Ilaria , Gallo Luisa , Sperone Emilio , Tripepi Sandro , Brunelli Elvira
Published: March 2011

Chlorpyrifos is an organophosphate pesticide among the most widely used in the world, which is suspected to be an endocrine‐disrupting compound. To determine the capacity of chlorpyrifos to affect gonadal differentiation in Rana dalmatina, tadpoles were exposed to this pesticide during larval development until completion of metamorphosis at ecologically relevant concentrations (0.025 and 0.05 mg/L). No effects of chlorpyrifos exposure on survival, development, or metamorphosis were observed. After a 1 month metamorphosis, the gonadal phenotype was determined by gross morphology and histological examination. Morphological and histological analysis revealed normal ovaries or testes in froglets belonging to control group, whereas testes from several froglets exposed to chlorpyrifos were interspersed with testicular oocytes in histological sections. Chlorpyrifos exposure during the entire larval period did not affect sex ratio, but reduced the percentage of males with histologically normal testes. The findings suggest that chlorpyrifos exposure has significant effects on gonadal differentiation in some animals by inducing an intersex condition and alterations to testicular morphology, and that R. dalmatina is sensitive to endocrine disruption. Thereby, this study provides evidence that the ecologically relevant concentrations of chlorpyrifos, although not adversely affect the survival, development, or metamorphosis, may interfere with sex differentiation and reproductive development of R. dalmatina via endocrine‐disrupting mechanisms. J. Exp. Zool. 315:314–327, 2011.. © 2011 Wiley‐Liss, Inc.
Simple efficient synthesis of 4‐aminoquinazoline via amidine of N‐arylamidoxime
Authors: Patil Sachin S. , Mhaske Pravin C. , Patil Sachin V. , Bobade Vivek D.
Published: March 2011

Preparation of 4‐amino‐2‐aryl quinazolines by reduction of N‐(2‐cyanoaryl) amidoximes via amidines using SnCl2 in ethanol. J. Heterocyclic Chem., (2011).