bluuebunny/crossref_metadata_2025 huggingface dataset:
VEGFR2 is selectively expressed by FOXP3high CD4+ Treg
Authors: Suzuki Hiroyuki , Onishi Hideya , Wada Junji , Yamasaki Akio , Tanaka Haruo , Nakano Kenji , Morisaki Takashi , Katano Mitsuo
Published: November 2009

CD25+ FOXP3+CD4+ T cells (Treg) have been considered to play an important role in immune tolerance against several tumor antigens. It has also been indicated that high‐level expression of FOXP3 (FOXP3high) is sufficient to confer suppressive activity to normal non‐Treg. Here, we showed for the first time that vascular endothelial growth factor receptor 2 (VEGFR2) is selectively expressed by FOXP3high but not FOXP3low Treg. Such VEGFR2+ Treg exist in several tissues including PBMC and malignant effusion‐derived lymphocytes. In conclusion, VEGFR2 may be a novel target for controlling Treg with highly suppressive function.
Natural and Unnatural A‐seco Terpenes from Pulegone: Synthesis of Galbanic Acid and Marneral Revisited
Authors: Corbu Andrei , Aquino Maurizio , Perez Manuel , Gandara Zoila , Arseniyadis Siméon
Published: November 2009

We describe herein an improved chiral‐pool strategy for assembling the core structure 3 (both antipodes) of various A‐seco terpenoids that have allowed us to prepare natural galbanic acid [(–)‐1] from (S)‐(–)‐pulegone [(–)‐2]. Furthermore, we were able to increase both the yield and step efficiency of the synthesis of marneral [(+)‐7] as well as to access higher homologues of ent‐galbanic acid [(+)‐4], ent‐secodrial [(+)‐5], and bis‐epi‐secochiliotrin (6) from (R)‐(+)‐pulegone [(+)‐2]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Adsorptive removal of Cd(II) ions from aqueous solutions by rice husk ash
Authors: Naiya Tarun Kumar , Bhattacharya Ashim Kumar , Das Sudip Kumar
Published: November 2009

This study deals with the adsorption characteristics of Cd(II) onto rice husk ash, low valued agricultural by‐product obtained during the rice processing from rice mill. The influences of pH, contact time, initial metal ion concentration, adsorbent concentration on the selectivity and sensitivity of the removal process were investigated. The optimum pH for adsorption was found to be 5 for Cd(II), and equilibrium was achieved within 2 h of contact time. Maximum adsorption of Cd(II) was obtained at an adsorbent dosage of 7.5 g/L, which may be considered as optimum adsorbent dosage level. Kinetics data were best described by pseudo‐second order model. The value of effective diffusion coefficient was of the order of 10−10 m2/s. The equilibrium adsorption data were better fitted to Freundlich isotherm models. The adsorption capacity (qmax) of rice husk ash for Cd(II) ions in terms of monolayer adsorption was 35.84 mg/g. The thermodynamic equilibrium constant and the Gibbs free energy were determined for and results indicated the spontaneous nature of the adsorption process. The adsorption energy calculated using Dubinin‐Radushkevich isotherm shows that adsorption of Cd(II) is chemical in nature. © 2009 American Institute of Chemical Engineers Environ Prog, 2009
AC Impedance Characterisation of a La0.8Sr0.2Co0.2Fe0.8O3–δ Electrode
Authors: Kournoutis V. Ch. , Tietz F. , Bebelis S.
Published: November 2009

The electrochemical characteristics of a La0.8Sr0.2Co0.2Fe0.8O3–δ electrode, synthesised using the spray‐drying technique and deposited via screen printing on a double layer Ce0.8Gd0.2O2–δ/ZrO2(8 mol% Y2O3) electrolyte, were studied using AC impedance spectroscopy. It was found that depending on temperature (600 to 850°C) and oxygen partial pressure P (0.7 to 100 kPa) the impedance characteristics of the electrode are determined by up to three different processes, which were identified as ionic conduction in the electrode bulk, interfacial charge transfer and gas phase diffusion, respectively, on the basis of the temperature and oxygen partial pressure dependence of the polarisation conductance associated with the individual processes and the related pseudocapacitance values.
Sulphonated Biphenylated Poly(aryl ether ketone)s for Fuel Cell Applications
Authors: Liu B. , Hu W. , Robertson G. P. , Kim Y. S. , Jiang Z. , Guiver M. D.
Published: November 2009

New series of fully aromatic poly(ether ketone)s with a biphenyl pendant groups were synthesised. A direct comparison of sulphonation reaction among monophenylated poly(ether ether ketone) (Ph‐PEEK), biphenylated poly(ether ether ketone) (BiPh‐PEEK) and PEEK (Victrex) was thoroughly investigated. Several advantages of the pendant‐phenyl poly(ether ketone)s compared with commercial PEEK were identified, including ready control over the site of sulphonation and degree of sulphonation (DS), and mild and rapid sulphonation. The basic membrane physical properties comprising of thermal and mechanical properties, dimensional stability and proton conductivity were studied. One new membrane, sulphonated biphenylated poly(ether ether ketone) (BiPh‐SPEEKDK) having a good combination of membrane properties was fabricated into a membrane electrode assembly (MEA), and it showed excellent direct methanol fuel cell (DMFC) performance.
Environmentally Friendly Fabrication of Surface‐Modified MWNT‐Supported Pt Nanocomposites for PEMFCs
Authors: Lee S. H. , Teshima K. , Jang I. Y. , Kim Y. J. , Sonobayashi Y. , Sugimura H. , Endo M. , Oishi S.
Published: November 2009

The functionalisation process of carbon nanotubes (CNTs) is required as a primary step in fabricating CNTs‐supported composites. In this study, multiwall carbon nanotubes (MWNTs) were treated under N2 atmospheric pressure plasma in order to functionalise their sidewalls with nitrogen‐containing and other functional groups. The surface‐treated MWNTs with –NO, –NH2 and other functional groups grafted on their sidewalls were analysed by X‐ray photoelectron spectroscopy (XPS). In addition, a certain amount of structural disorder generated by the continuous decoration of functional groups on the MWNT sidewalls was investigated by Raman spectroscopy and high‐resolution transmission electron microscopy (TEM). The functional groups introduced by N2 atmospheric pressure plasma were used as the chemical reaction sites for fabricating the Pt/MWNT nanocomposites. The deposition manner of Pt nanoparticles from their precursor ions (PtCl2–6) was positively correlated with the proportion of the surface functional groups. The plasma‐treated MWNT‐supported platinum catalysts exhibited higher electrochemical activity for hydrogen adsorption/desorption and methanol oxidation than did the catalysts prepared with MWNTs treated by HNO3/H2SO4. These results were due to the uniformly deposited Pt nanoparticles on the MWNTs caused by the strong interactions between the Pt precursors and the functional groups formed by N2 atmospheric pressure plasma.
N‐glycan based models improve diagnostic efficacies in hepatitis B virus‐related hepatocellular carcinoma
Authors: Fang Meng , Zhao Yun‐Peng , Zhou Fei‐Guo , Lu Lun‐Gen , Qi Peng , Wang Hao , Zhou Kun , Sun Shu‐Han , Chen Cui‐Ying , Gao Chun‐Fang
Published: November 2009

The early diagnosis of hepatocellular carcinoma (HCC) is of great clinical desirable due to lack of specific and sensitive markers. Alterations in the sugar chains of glycoprotein synthesized by the liver contribute to the molecular basis of abnormalities in carcinogenesis. This study aims to construct and assess the diagnostic value of N‐glycan based diagnostic model in HCC identification and follow‐up. A total of 393 subjects including HBV‐related HCC, liver fibrosis and healthy controls were recruited. Follow‐up was carried out before and after surgical treatment in HCC. N‐glycome of serum glycoprotein was profiled by DNA sequencer‐assisted fluorophore‐assisted carbohydrate electrophoresis (DSA‐FACE). Multiparameters diagnostic models were constructed based on N‐glycan markers. The result found that 2 N‐glycan structure abundances (NG1A2F, Peak 4; NA3Fb, Peak 9) were useful as N‐glycan markers. The diagnostic efficacy of the log ratio [log(p9/4)] was similar to that of AFP in differentiating HCC from fibrosis. The accuracy and sensitivity of the diagnostic model combining AFP and N‐glycan markers (Cscore B) were increased 7–10% compared with that of AFP. Log(p9/4) was more efficient in monitoring the progression of HCC with regarding to vascular invasion at improved specificity (16%) and accuracy (8%) compared with that of AFP. The N‐glycan markers were found to be changed significantly after surgical resection in HCC follow‐up. We conclude that the branching α (1,3)‐fucosylated triantennary glycan and a biantennary glycan are promising as N‐glycan markers. The diagnostic models based on the N‐glycan markers and AFP improve the efficacy in HCC diagnosis and progression monitoring.
SYUNZ‐16, a newly synthesized alkannin derivative, induces tumor cells apoptosis and suppresses tumor growth through inhibition of PKB/AKT kinase activity and blockade of AKT/FOXO signal pathway
Authors: Deng Rong , Tang Jun , Xie Bing‐Fen , Feng Gong‐Kan , Huang Yu‐Han , Liu Zong‐Chao , Zhu Xiao‐Feng
Published: November 2009

Alkannin is the major bioactive compound of Arnebia euchroma roots, which is used in many therapeutic remedies in Chinese traditional medicine. SYUNZ‐16 is a new derivative of alkannin. In this study, anticancer effects of SYUNZ‐16 on human lung adenocarcinoma cell line GLC‐82 and human hepatocarcinoma cell line Hep3B were tested in vitro. The results showed SYUNZ‐16 could obviously inhibit the proliferation of these cancer cell lines via induction of apoptosis, with the evidence of increasing AnnexinV‐positive cells and cleaved caspase‐3 and PARP fragments. More importantly, we found that SYUNZ‐16 could inhibit AKT activity in cell‐free system. Treatment of cancer cells with SYUNZ‐16 decreased the phosphorylation of AKT. Additionally, SYUNZ‐16 partially attenuated the phosphorylation levels of FKHR and FKHRL1 in a dose‐dependent and time‐dependent fashion, and led to an increase in the nuclear accumulation of exogenous FKHR, and upregulated the mRNA expression of Bim and TRADD in cancer cells. Further study showed that constitutively activated AKT1 transfection could reduce apoptosis induction mediated by SYUNZ‐16. The in vivo experiments showed that SYUNZ‐16 had inhibitory effects on S‐180 sarcoma implanted to mice. And in GLC‐82 xenograft models, SYUNZ‐16 at 20 mg/kg/qod remarkably inhibited the tumor growth with the T/C value of 45.3%. Taken together, SYUNZ‐16 might be a potent inhibitor of AKT signaling pathway in tumor cells. These data provide evidence for the development of SYUNZ‐16 as a potential antitumor drug candidate for further research and development.
UV curable polyester polyol acrylate/bentonite nanocomposites: Synthesis, characterization, and drug release
Authors: Thatiparti Thimma Reddy , Tammishetti Shekharam , Nivasu Muram V.
Published: November 2009

Polyesterpolyolacrylate/bentonite nanocomposites, capable of in situ photo polymerization, were synthesized and characterized. The organically modified bentonite clay was prepared by an ion exchange process, in which sodium ions were replaced by alkyl ammonium ions. Organo modification of bentonite was confirmed from X‐ray diffraction and fourier transform‐infrared data. Microstructures were characterized by XRD data and transmission electron microscopy (TEM). Both XRD data and TEM images of polyester polyol acrylate/organo modified bentonite nanocomposites indicated that most of silicate layers were intercalated into the acrylate matrix. The resulting nanocomposites were characterized by gel content, water equilibrium swell, tensile strength, and in vitro degradation. The results showed that water equilibrium swell and in vitro degradation of these nanocomposites decreased with increase in the clay content. The tensile strength of these nanocomposites also increased with increase in the clay content. Release of two model drugs namely sulfamethoxazole and diclofenac sodium (DS) from these nanocomposites was studied in phosphate buffer saline pH = 7.4 at 37°C. The drug release studies showed that sulfamethoxazole released slower than DS from polyester polyol acrylate nanocomposites. Therefore, these materials may be useful for mucoadhesive drug carriers and other biomedical applications. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Differences between bisphosphonates in binding affinities for hydroxyapatite
Authors: Lawson M. A. , Xia Z. , Barnett B. L. , Triffitt J. T. , Phipps R. J. , Dunford J. E. , Locklin R. M. , Ebetino F. H. , Russell R. G. G.
Published: November 2009

Bisphosphonates (BPs) inhibit bone resorption and are widely used for the treatment of bone diseases, including osteoporosis. BPs are also being studied for their effects on hydroxyapatite (HAP)‐containing biomaterials. There is a growing appreciation that there are hitherto unexpected differences among BPs in their mineral binding affinities that affect their pharmacological and biological properties. To study these differences, we have developed a method based on fast performance liquid chromatography using columns of HAP to which BPs and other phosphate‐containing compounds can adsorb and be eluted by using phosphate buffer gradients at pH 6.8. The individual compounds emerge as discrete and reproducible peaks for a range of compounds with different affinities. For example, the peak retention times (min; mean ± SEM) were 22.0 ± 0.3 for zoledronate, 16.16 ± 0.44 for risedronate, and 9.0 ± 0.28 for its phosphonocarboxylate analog, NE10790. These results suggest that there are substantial differences among BPs in their binding to HAP. These differences may be exploited in the development of biomaterials and may also partly explain the extent of their relative skeletal retention and persistence of biological effects observed in both animal and clinical studies. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2010
Improved biological performance of microarc‐oxidized low‐modulus Ti‐24Nb‐4Zr‐7.9Sn alloy
Authors: Wu Jiang , Liu Zheng‐Ming , Zhao Xiang‐Hui , Gao Yang , Hu Jiang , Gao Bo
Published: November 2009

Ti‐24Nb‐4Zr‐7.9Sn (TNZS) is a newly developed β‐titanium alloy with low modulus and it has been considered as good material for dental or orthopedic implant. The purpose of the current study is to evaluate the effect of micro‐arc oxidation (MAO) treatment on the biological performance of TNZS surface. The phases, morphology and chemical composition of the MAO‐treated surface were characterized by X‐ray diffraction, energy dispersive spectroscope and scanning electron microscopy analysis respectively. Then we tested the biocompatibility by examining the cell morphology and viability of osteoblast cells growing on MAO‐TNZS surface. The bone binding strength of the specimens was evaluated by removal torque test after implantation in rabbit tibiae for 6 weeks. Compared with the none‐treated titanium and TNZS specimens, MAO treated TNZS specimens showed a significant increase (p<0.05) in hydrophilicity, roughness, cell viability and removal torque forces. In summary, MAO treatment helps to form a porous surface with a biologically active bone‐like apatite layer on TNZS specimens, which may improve the biological response of MAO‐TNZS implants. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Controlled release of tetracycline from biodegradable β‐tricalcium phosphate composites
Authors: Luginbuehl Vera , Ruffieux Kurt , Hess Claudia , Reichardt Dennis , von Rechenberg Brigitte , Nuss Katja
Published: November 2009

For use in the prevention of bone infections, a novel controlled release system composed of β‐tricalcium phosphate (TCP) granules with biodegradable coatings incorporating the antibiotic drug tetracycline (TC) was developed. Six formulations using poly(D,L‐lactide) and poly(D,L‐lactide‐co‐glycolide) as coating materials to incorporate TC were prepared and tested in vitro and in vivo. Release of TC from TCP composites was dependent on the biodegradability of the used polymers and on physical–chemical interactions of TC with the polymer materials. Three characteristic release profiles were obtained: slow release lasting up to 67 days, intermediate release with 60% of the total dose released up to day 20, and fast release with a high initial burst and 90% of TC released within 4 days. Even though TC decomposition products had formed during in vitro release, no cytotoxic effects on osteoblast‐like cells were observed. The biological activity of TC after incorporation into PL(G)A films was confirmed using a TC‐repressible promoter system in genetically engineered Chinese Hamster Ovary (CHO) cells. TC‐loaded TCP composites implanted in ovine cancellous bone defects showed good biocompatibility and new bone formation in the histological evaluation. No differences in the cellular reactions were seen between antibiotic‐loaded composites and the control group. These experimental results indicate the potential of coated TCP composites to be used as local carrier system for controlled TC delivery with different release kinetics and good in vitro and in vivo biocompatibility. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
A Review—Micromorphological evidence of degradation in resin‐dentin bonds and potential preventional solutions
Authors: Hashimoto Masanori
Published: November 2009

Resin adhesion to dentin was first achieved in 1982 through mechanical hybridization between resin and collagen fibrils using an adhesive resin containing a functional monomer. Over the last 2 decades, newly developed adhesive resins have attempted to improve the bond strength at least in the first 24 h after bonding. Although much is known about the initial bond strength, learned through morphological analysis, the long‐term durability of bonds has not yet been established analytically. However, numerous recent studies have shown chemical biodegradation of resin‐dentin bonds under various testing regimes. In general, studies have shown that dentin bond strength decreases over time due to degradation of the resin and the collagen fibrils within the bonds. Furthermore, crystal formation around cured bonding resins has been reported in a number of adhesives after long‐term water storage. However, the extent and process of degradation or crystallization is adhesive type specific. This review mainly summarizes the most recent and state of the art work in degradation of the bonding of dental restorative compounds with dentin based on micromorphological data of scanning and transmission electron microscopy. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Rumination fosters indecision in dysphoria
Authors: van Randenborgh Annette , de Jong‐Meyer Renate , Hüffmeier Joachim
Published: November 2009

This study investigated the effects of rumination on indecision, assessed as high levels of perceived decision difficulty, low confidence in a decision, and decision latency. Dysphoric and nondysphoric participants were assigned to either a rumination or a distraction induction. Subsequently, they made four decisions with alleged real‐life consequences. As predicted, rumination exhibited a negative effect on dysphoric participants' decision‐making process. They experienced the decisions as more difficult and had less confidence in their choices. No effects emerged on the measure of decision time. Mediation analyses revealed that increased difficulty of the decisions was due to self‐focused thinking as a cognitive consequence of rumination, while reduced confidence in the decisions was partly mediated by negative affect that resulted from rumination. The finding that rumination affects the important life domain of decision making by fostering indecision in dysphoric individuals is a central extension of previous studies on rumination's consequences. In addition, these results provide insight into the depressive symptom of indecisiveness by revealing its underlying mechanisms. © 2009 Wiley Periodicals, Inc. J Clin Psychol 66: 229–248, 2010.
Concerns about substandard training for prescription privileges for psychologists
Authors: Heiby Elaine M.
Published: November 2009

This Commentary on the Muse and McGrath study (this issue, pp. XXX–XXX) refutes its conclusion that the amount of training for prescription privileges for psychologists (R×P) is equal to or greater than that for psychiatric nurse practitioners and physicians. First, the sample failed to include only training programs for nurses and psychologists that lead to independent prescribing. Second, training was defined by an arbitrary, nonvalidated list of “key content areas” that excluded much of the standard medical curricula for nurses and physicians to prescribe. Third, the levels of training for which the “key content areas” were assessed omitted undergraduate prerequisites, apprenticeships, supervised practice, and residencies that are a standard part of the nursing and physician programs studied. R×P training remains substandard. © 2009 Wiley Periodicals, Inc. J Clin Psychol: 66: 1–8, 2010.
Extraction of alcohol using emulsion liquid membrane consisting of paraffin oil as an organic phase and lecithin as a surfactant
Authors: Chanukya B.S. , Rastogi Navin K.
Published: November 2009

BACKGROUND: This paper reports on the use of a liquid emulsion membrane involving paraffin light oil as membrane phase and lecithin as surfactant for the extraction of alcohol from anthocyanin extract and simulated pineapple wine.

RESULTS: The extraction of alcohol was found to depend on the many factors such as surfactant concentration, contact time, stirring speed, stirring time, and ratio of membrane emulsion to feed volume. Results showed that optimum conditions for maximum alcohol extraction (25%) were lecithin concentration 3%, contact time 20 min, stirring speed 250 rpm and ratio of membrane emulsion to feed volume 1:2. Multistage extraction using this liquid emulsion membrane was found to completely remove alcohol from anthocyanin extract and from simulated pineapple wine in seven stages and five stages, respectively.

CONCLUSION: This liquid emulsion membrane was found to be a useful method for the extraction of alcohol from aqueous feed. Copyright © 2009 Society of Chemical Industry
Access to indoles via Diels‐Alder reactions of 3‐vinylpyrroles
Authors: Noland Wayland E. , Lanzatella Nicholas P.
Published: November 2009

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N‐p‐Toluenesulfonyl‐3‐vinylpyrrole underwent endo‐addition [4 + 2] cycloaddition reactions with maleimides and benzoquinones, followed by isomerization to give tetrahydroindoles in good yields. Dehydrogenation with activated MnO2 in refluxing toluene gave the corresponding indoles in fair to good yields. Detosylation via saponification or with magnesium in refluxing methanol gave the N‐H indoles in moderate to good yields. This method for formation of indoles is both convergent and versatile and uses starting materials that are conveniently prepared. J. Heterocyclic Chem., (2009).
Syntheses and reactions of halo‐ and arylazo‐substituted 3‐(3‐(2‐naphthyl)acryloyl)tropolones: Formation of (naphthalen‐ 2‐yl)vinyl)‐substituted heterocycle‐fused troponoid compounds
Authors: Gao Wentao , Sun Mingchun , Li Yang , Li Wei , Imafuku Kimiaki
Published: November 2009

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The starting substrate 3‐(3‐(2‐naphthyl)acryloyl)tropolone (1) was achieved by the aldol condensation reaction of 3‐acetyltropolone with 2‐naphthaldehyde. Compound (1) reacted with bromine to give 7‐bromo‐(2) and 5,7‐dibromo‐3‐(3‐(2‐naphthyl)acryloyl)tropolone (3) according to the amount of the brominated reagent. Iodination of 1 gave 7‐iodo‐3‐(3‐(2‐naphthyl)acryloyl)tropolone (4). Azo‐coupling reactions of 1, 2, and 4 gave 5‐arylazo‐3‐(3‐(2‐naphthyl)acryloyl) tropolones (5, 6, 7, 8). Compounds 1, 2, 3, 4 reacted with hydroxyamine to give 3‐[2‐(2‐naphthyl)vinyl]‐8H‐cyclohepta[d]isoxazol‐8‐ones (9, 10, 11, 12). The reactions of 1, 2, 3, 4 with phenylhydrazine and substituted phenylhydrazines gave 3‐[2‐(2‐naphthyl)vinyl]‐1‐phenylcyclohepta[c]pyrazol‐8(1H)‐ones (13, 14, 15, 16, 17, 18, 19, 20, 21). J. Heterocyclic Chem., (2009).
Microwave‐assisted Cadogan reaction for the synthesis of 2‐aryl‐2H‐indazoles, 2‐aryl‐1H‐benzimidazoles, 2‐carbonylindoles, carbazole, and phenazine
Authors: Creencia Evelyn Cuevas , Kosaka Masahiro , Muramatsu Toshikatsu , Kobayashi Masashi , Iizuka Tomohiro , Horaguchi Takaaki
Published: November 2009

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The Cadogan reaction, a widely accepted route for the synthesis of nitrogen containing heterocycles, is modified by using microwave radiation as the source of heat instead of the conventional heating by reflux in a nitrogen atmosphere for several hours. Appropriate starting materials were mixed with triethyl phosphite or triphenylphosphine and irradiated with microwaves for several minutes at a specific power to give the desired products. The indazoles were prepared by irradiating N‐(2‐nitrobenzylidene) anilines with triethyl phosphite at 200 W for 12–14 min to give 85–92% product yields. Irradiation of the mixture of N‐benzylidene‐2‐nitroanilines and triphenylphosphine at 200 W for 3–5 min yielded 93–96% of the benzimidazoles. The carbonylindoles were obtained in 61–68% yields by irradiating 2‐nitrochalcone or alkyl 2‐nitrocinnamates and triphenylphosphine with microwaves at 80–200 W for 8–11 min. The mixture of 2‐nitrobiphenyl and triphenylphosphine yielded 96% of carbazole when irradiated with microwaves at 200 W for 2 min while 75% of phenazine was obtained by irradiating the mixture of 2‐nitrodiphenylamine and triphenylphosphine with microwaves at 200 W for 3.5 min. These results show that microwave‐assisted Cadogan reactions gave better product yields at shorter reaction times. J. Heterocyclic Chem., (2009).
Variability of water quality in a riparian wetland with interacting shallow groundwater and surface water
Authors: Schmalz Britta , Springer Pina , Fohrer Nicola
Published: November 2009

Lowland catchment hydrology is dominated by shallow groundwater with complex interactions between groundwater and surface water. In lowland catchments of N Germany, a high fraction of agricultural land is drained and therefore influenced by fast water transport to discharge systems with resulting alterations to water quality. The investigated catchment area “Kielstau” (approx. 50 km2) in the N of Schleswig‐Holstein serves as an example. Detailed investigations on the interactions between groundwater, river, and ditch‐water quality were evaluated at a drained riparian wetland area (0.15 km2) used as grassland in the central part of this catchment. The water quality in the drainage ditches showed variability dependent on their hydrological integration. At the far‐from‐river end, groundwater and ditch‐water quality were in most parameters much more alike than at the close‐to‐river end. The composition of ditch water at the close‐to‐river end of the ditch was determined by transformation processes and dilution which took place along the ditch much more than exfiltration processes like those that were dominant at the far‐from‐river end. In most cases, the mean NH$ _4^+ $ concentrations were higher in the groundwater than in the ditches, but the highest concentrations were found all along the time in the close‐to‐river sampling points and in the river. The highest NO$ _3^- $ concentration was observed in a ditch influenced by an adjacent arable field as well as in the river. The concentrations of phosphate and total P were lower in groundwater than in the ditch water.
Biogeochemical interfaces in soil: The interdisciplinary challenge for soil science
Authors: Totsche Kai U. , Rennert Thilo , Gerzabek Martin H. , Kögel‐Knabner Ingrid , Smalla Kornelia , Spiteller Michael , Vogel Hans‐Jörg
Published: November 2009

Soil, the “Earth's thin skin” serves as the delicate interface between the biosphere, hydrosphere, atmosphere, and lithosphere. It is a dynamic and hierarchically organized system of various organic and inorganic constituents and organisms, the spatial structure of which defines a large, complex, and heterogeneous interface. Biogeochemical processes at soil interfaces are fundamental for the overall soil development, and they are the primary driving force for key ecosystem functions such as plant productivity and water quality. Ultimately, these processes control the fate and transport of contaminants and nutrients into the vadose zone and as such their biogeochemical cycling. The definite objective in biogeochemical‐interface research is to gain a mechanistic understanding of the architecture of these biogeochemical interfaces in soils and of the complex interplay and interdependencies of the physical, chemical, and biological processes acting at and within these dynamic interfaces in soil. The major challenges are (1) to identify the factors controlling the architecture of biogeochemical interfaces, (2) to link the processes operative at the individual molecular and/or organism scale to the phenomena active at the aggregate scale in a mechanistic way, and (3) to explain the behavior of organic chemicals in soil within a general mechanistic framework. To put this in action, integration of soil physical, chemical, and biological disciplines is mandatory. Indispensably, it requires the adaption and development of characterization and probing techniques adapted from the neighboring fields of molecular biology, analytical and computational chemistry as well as materials and nano‐sciences. To shape this field of fundamental soil research, the German Research Foundation (DFG) has granted the Priority Program “Biogeochemical Interfaces in Soil”, in which 22 individual research projects are involved.
Xylan‐Based Nanoparticles: Prodrugs for Ibuprofen Release
Authors: Daus Stephan , Heinze Thomas
Published: November 2009

Esterification of xylan with ibuprofen via activiation of the carboxylic acid with N,N′‐carbonyldiimidazole (CDI) yields products of high drug loadings. Subsequent sulfation of xylan ibuprofen esters using the gentle agent SO3/DMF was successfully carried out in order to modify hydrophobicity of the xylan esters. The structure of the novel xylan esters was evaluated by means of NMR spectroscopy. The resulting xylan derivatives self assemble into spherical nanoparticles with mean diameters ranging from 162 to 472 nm. Preliminary stability measurements indicate that hydrolytic stability decreases with increase in degree of substitution of sulfate groups. Thus, a new concept toward improved drug delivery from polysaccharide‐based nanoparticles can be established here.

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Electrochemical impedance spectroscopy investigation of chlorinated rubber‐based coatings containing polyaniline as anticorrosion agent
Authors: Baldissera A. F. , Freitas D. B. , Ferreira C. A.
Published: November 2009

Corrosion protection of mild steel by a newly developed chlorinated rubber (CR)‐based coating system containing the inherently conductive polymer polyaniline (PAni) as an anticorrosion agent was studied. The synthesis of PAni and preparation of CR‐based paint containing this polymer are described herein. The corrosion behavior of mild steel samples coated with a CR resin, CR/PAni‐EB (emeraldine base), CR/PAni‐ES (emeraldine salt), and CR/DBSA‐doped PAni were investigated in 3.5% NaCl solution. For this purpose, electrochemical impedance spectroscopy and corrosion potential versus time measurements were utilized. It was found that the addition of the two forms of PAni, doped and undoped, to the CR resin increased its corrosion protection efficiency.
Electrochemical corrosion of silicon carbide ceramics
Authors: Sydow U. , Schneider M. , Herrmann M. , Kleebe H.‐J. , Michaelis A.
Published: November 2009

Recently, SiC‐based ceramics have been found to exhibit corrosion damage patterns, which can only be explained by electrochemical processes. Therefore, the current work focusses on the electrochemical test procedures to determine the corrosion behaviour of solid state sintered silicon carbide (SSiC) ceramics in acidic and alkaline media. The corrosion current densities have been determined from linear voltammetric scans. At anodic polarization potentials, electrochemically induced etching patterns were observed in alkaline solution. The formation of pores and crevices during electrochemical oxidation in acidic solution could be monitored by field emission scanning electron microscopy (FESEM) in addition to transmission electron microscopy (TEM). Impedance spectra measured after anodic polarization could be described by the assumption of a pore model equivalent circuit.
Adsorption rate and protective effect of tributyl(cyclohexyl)ammonium chloride inhibitor on the acidic corrosion of steel
Authors: Magerramov A. M. , Rzayev Z. M. O. , Aliyev I. A. , Khalilova F. I.
Published: November 2009

The inhibition of corrosion of a steel surface by an inhibitor, tributyl(cyclohexyl)ammonium chloride (TBCA), was investigated by gravimetric and electrochemical polarization measurements in various aqueous solutions of HCl and H2SO4 acids. It is known that the most extensive corrosive destruction proceeds during the initial stage of contact between the metallic surface and the aggressive surroundings. The change from H2SO4 to HCl considerably decreases the time for formation of an adsorption layer. The high adsorption of the surface‐active cationic TBCA on the steel electrode surface can be explained by the specific adsorption of Cl− anions increasing the negative charge on the electrode surface. It was observed that the value of the polarizing current can be increased from time to time by addition of more TBCA inhibitor. This fact can be explained by the low stability of the film‐forming layer on the steel. A similar decrease of the protective effect was also observed in HCl solution. The inhibitor provides at least a slowing of the corrosion process (τ = 21 min). It was found that an increase in H2SO4 concentration from 1.0 to 0.2 N did not change the protective action of the inhibitor and had rather high values (θ = 283 ma/h, ψ = 84%, and τ = 14 min at [I] = 3.5 × 10−4 mol/L). It was shown that the attraction constant has a negative value (A = −1.5 and Ka = 22.3) for the inhibitor, which relates to a high value for the adsorption ability of TBCA in HCl solution and therefore with the intermolecular repulsive force between adsorption molecules having similar charges. The protective action of TBCA increases with an increase in temperature, which is correlated with the chemical nature of its adsorption on the steel surface.
Historic Account of the Development in the Understanding of the Propagation Kinetics of Acrylate Radical Polymerizations
Authors: van Herk Alex M.
Published: November 2009

Acrylates and methacrylate polymers are widely used in a variety of applications such as coatings, adhesives, and synthetic rubbers. In a continuous effort to increase the understanding and control over the radical (co)polymerizations of acrylate monomers the kinetic parameters, such as the propagation and termination rate constants, need to be determined. In particular, the propagation rate coefficients of the family of acrylate monomers have been a topic of intense scientific study over the last 10 years or so. In the last decade an almost full understanding of the complicated aspects of acrylate radical polymerizations has been established. It is the purpose of this essay to give a short historic account of the developments in this understanding of acrylate radical polymerizations.

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Online real‐time reconstruction of adaptive TSENSE with commodity CPU/GPU hardware
Authors: Roujol Sébastien , de Senneville Baudouin Denis , Vahala Erkki , Sørensen Thomas Sangild , Moonen Chrit , Ries Mario
Published: November 2009

Adaptive temporal sensitivity encoding (TSENSE) has been suggested as a robust parallel imaging method suitable for MR guidance of interventional procedures. However, in practice, the reconstruction of adaptive TSENSE images obtained with large coil arrays leads to long reconstruction times and latencies and thus hampers its use for applications such as MR‐guided thermotherapy or cardiovascular catheterization. Here, we demonstrate a real‐time reconstruction pipeline for adaptive TSENSE with low image latencies and high frame rates on affordable commodity personal computer hardware. For typical image sizes used in interventional imaging (128 × 96, 16 channels, sensitivity encoding (SENSE) factor 2‐4), the pipeline is able to reconstruct adaptive TSENSE images with image latencies below 90 ms at frame rates of up to 40 images/s, rendering the MR performance in practice limited by the constraints of the MR acquisition. Its performance is demonstrated by the online reconstruction of in vivo MR images for rapid temperature mapping of the kidney and for cardiac catheterization. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
High‐resolution magnetic resonance angiography in the mouse using a nanoparticle blood‐pool contrast agent
Authors: Howles Gabriel P. , Ghaghada Ketan B. , Qi Yi , Mukundan Srinivasan , Johnson G. Allan
Published: November 2009

High‐resolution magnetic resonance angiography is already a useful tool for studying mouse models of human disease. Magnetic resonance angiography in the mouse is typically performed using time‐of‐flight contrast. In this work, a new long‐circulating blood‐pool contrast agent—a liposomal nanoparticle with surface‐conjugated gadolinium (SC‐Gd liposomes)—was evaluated for use in mouse neurovascular magnetic resonance angiography. A total of 12 mice were imaged. Scan parameters were optimized for both time‐of‐flight and SC‐Gd contrast. Compared to time‐of‐flight contrast, SC‐Gd liposomes (0.08 mmol/kg) enabled improved small‐vessel contrast‐to‐noise ratio, larger field of view, shorter scan time, and imaging of venous structures. For a limited field of view, time‐of‐flight and SC‐Gd were not significantly different; however, SC‐Gd provided better contrast‐to‐noise ratio when the field of view encompassed the whole brain (P < 0.001) or the whole neurovascular axis (P < 0.001). SC‐Gd allowed acquisition of high‐resolution magnetic resonance angiography (52 × 52 × 100 micrometer3 or 0.27 nL), with 123% higher (P < 0.001) contrast‐to‐noise ratio in comparable scan time (∼45 min). Alternatively, SC‐Gd liposomes could be used to acquire high‐resolution magnetic resonance angiography (0.27 nL) with 32% higher contrast‐to‐noise ratio (P < 0.001) in 75% shorter scan time (12 min). Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Neuromuscular diseases associated with HIV‐1 infection
Authors: Robinson‐Papp Jessica , Simpson David M.
Published: November 2009

Neuromuscular disorders are common in human immunodeficiency virus (HIV); they occur at all stages of disease and affect all parts of the peripheral nervous system. These disorders have diverse etiologies including HIV itself, immune suppression and dysregulation, comorbid illnesses and infections, and side effects of medications. In this article, we review the following HIV‐associated conditions: distal symmetric polyneuropathy; inflammatory demyelinating polyneuropathy; mononeuropathy; mononeuropathy multiplex; autonomic neuropathy; progressive polyradiculopathy due to cytomegalovirus; herpes zoster; myopathy; and other, rarer disorders. Muscle Nerve, 2009
Developing reference data for nerve conduction studies: An application of quantile regression
Authors: Peng Limin , Wuu Joanne , Benatar Michael
Published: November 2009

Introduction: The interpretation of nerve conduction studies, as with any diagnostic test, requires an ability to differentiate normal from abnormal. To this end there have been many efforts to establish reference or normative data, but they have been hampered by a variety of methodological shortcomings. The goal of this article is to introduce a statistical method known as quantile regression, which we contend is better suited than existing methods to generate reference data, especially when there is a need to adjust for covariates. Methods: Statistical methods previously used for generation of reference data are reviewed. Quantile regression is presented and used to estimate the lower percentiles for response amplitudes of the radial sensory and tibial motor nerves. Results: Using data from 190 subjects, it is possible to estimate as low as the 2nd percentile for the radial nerve. Using data from 99 subjects it is possible to estimate as low as the 4th percentile for the tibial nerve. Percentile estimation for both nerves required adjustment for age, but no other covariates. Discussion: Quantile regression is well suited to the estimation of extreme percentiles, the very percentiles that are most relevant to reference data. It is also less dependent on data distribution and permits covariate adjustment, even for continuous variables such as age, which are clinically important determinants of reference data for nerve conduction studies. We recommend the use of quantile regression for future studies of reference data. Muscle Nerve 40: 763–771, 2009
Reference data for commonly used sensory and motor nerve conduction studies
Authors: Benatar Michael , Wuu Joanne , Peng Limin
Published: November 2009

Introduction: The goal of this study was to generate reference data for a wide range of sensory and motor nerve conduction studies (NCSs) that are commonly used in routine electrodiagnostic practice. Methods: NCS data were collected from control subjects with a normal neurological examination and no known risk factors for or symptoms to suggest disease of the peripheral nervous system. Thirteen sensory and motor nerves were studied in the upper and lower limbs using standard recording techniques. Quantile regression was used to obtain estimates of the lower (e.g., 5th) percentiles for sensory and motor amplitudes and conduction velocities, as well as estimates of the upper (e.g., 95th) percentiles for distal motor latency and F‐wave latencies. Results: Reference data for sensory and motor amplitudes required adjustment for age; F‐wave latencies required adjustment for gender. Covariate adjustments were not required for other reference data. Data from N = 100 and N = 190 subjects permitted estimation of as low as the 4th and 2nd percentile, respectively, but further increases to N = 296 did not permit estimation of a more extreme percentile. Discussion: Efforts to develop reference data require careful selection of study subjects; sufficient sample size; adjustment for relevant covariates; and appropriate statistical methods for analysis. Reference data that cannot be estimated reliably due to absent potentials or data variability must be interpreted with caution. We present data for a range of clinically applicable reference percentiles, but judgment regarding which is most appropriate for diagnostic purpose awaits empiric evaluation in a disease population. Muscle Nerve 40: 772–794, 2009
”Globalisierung ist keine Einbahnstraße“
Authors: Bulmahn Maren , Guggolz Ernst
Published: November 2009

China wird als erstes Land die aktuelle Krise überstanden haben. Über die Chancen der chemischen Industrie Chinas und der Welt sprach Dahai Yu mit den Nachrichten aus der Chemie.
”Nicht den Zug verpassen“
Authors: Bulmahn Maren , Guggolz Ernst
Published: November 2009

Ob — und wenn ja, welche — Spezialchemikalien in Zukunft in Saudi‐Arabien mit Gewinn produzierbar sind, berichtet Hubert Bader, Partner bei Chemadvice in den Nachrichten aus der Chemie.
Eliteuniversität des 19. Jahrhunderts
Authors: Lenoir Dieter
Published: November 2009

Osteuropa war im 19. Jahrhundert ein wichtiges Zentrum der Chemie. Ein Vermittlerrolle zwischen Ost und West spielte die deutschsprachige Universität Dorpat (heute Tartu) in Estland.
Die Farbe der Tonkrieger: Eine Aufgabe für die Chemie
Authors: Langhals Heinz
Published: November 2009

Die Terrakotta‐Armee, welche die Grabstätte des ersten chinesischen Kaisers Qin Shihuangdi bewacht, gehört zu den größten archäologischen Funden überhaupt. Ihre Restaurierung ist mit etablierten Methoden kaum zu beherrschen und erfordert neue chemische Wege und oft unkonventionelle Methoden, etwa bei der Konservierung der Farbschichten der Terrakotta‐Figuren.
Performance evaluation of a 32‐element head array with respect to the ultimate intrinsic SNR
Authors: Lattanzi Riccardo , Grant Aaron K. , Polimeni Jonathan R. , Ohliger Michael A. , Wiggins Graham C. , Wald Lawrence L. , Sodickson Daniel K.
Published: November 2009

The quality of an RF detector coil design is commonly judged on how it compares with other coil configurations. The aim of this article is to develop a tool for evaluating the absolute performance of RF coil arrays. An algorithm to calculate the ultimate intrinsic signal‐to‐noise ratio (SNR) was implemented for a spherical geometry. The same imaging tasks modeled in the calculations were reproduced experimentally using a 32‐element head array. Coil performance maps were then generated based on the ratio of experimentally measured SNR to the ultimate intrinsic SNR, for different acceleration factors associated with different degrees of parallel imaging. The relative performance in all cases was highest near the center of the samples (where the absolute SNR was lowest). The highest performance was found in the unaccelerated case and a maximum of 85% was observed with a phantom whose electrical properties are consistent with values in the human brain. The performance remained almost constant for 2‐fold acceleration, but deteriorated at higher acceleration factors, suggesting that larger arrays are needed for effective highly‐accelerated parallel imaging. The method proposed here can serve as a tool for the evaluation of coil designs, as well as a tool to guide the development of original designs which may begin to approach the optimal performance. Copyright © 2009 John Wiley & Sons, Ltd.
Damage development in a noncrimp‐glass fabric reinforced epoxy composite material
Authors: Cruz‐Santos G. , Rodríguez‐Laviada J. , Rios‐Soberanis C.R.
Published: November 2009

The relationship between textile architecture and the damage sequence under tensile loading has been investigated experimentally for a composite material reinforced with a noncrimp glass‐fiber textile of configuration [0°, +45°, 90°, −45°] stacking sequence based on epoxy resin matrix cured with high‐temperature hardener. The system chosen for this work consists of a bifunctional epoxy, diglycidyl ether of bisphenol A, cured with a tetrafunctional amine, diaminodiphenyl sulfone (DDS). This system ensures to obtain a rigid material with excellent mechanical properties in order to observe, analyze, and identify the process and progress of the generated damage and the failure mechanism which leads to the materials fracture. The properties have been studied for each ply direction at 0°, +45°, 90°, and −45° in order to make a comparative assessment of the influence of the polyester (PES) yarns in zig‐zag and unidirectional geometry, that hold together the four plies in the textile, in the composite damage generation. The laminates were uniaxially tensile loaded until final fracture occurred. It was found that PES threads have an effect on cracking progression depending on the textile orientation. POLYM. COMPOS., 2009. © 2009 Society of Plastics Engineers