bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Studies on Aryl H‐Phosphonates. Part 1. An Efficient Method for the Preparation of Deoxyribo‐ and Ribonucleoside 3′‐H‐phosphonate Monoesters by Transesterification of Diphenyl H‐Phosphonate.
Authors: JANKOWSKA J. , SOBKOWSKI M. , STAWINSKI J. , KRASZEWSKI A.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Total Synthesis of Arthrobacilin A.
Authors: GARCIA D. M. , YAMADA H. , HATAKEYAMA S. , NISHIZAWA M.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Titanium Mediation of Aldol Reactions in Fridamycin and Vineomycinone Syntheses.
Authors: PAUSLER G. M. , RUTLEDGE P. S.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Towards the Synthesis of Swinholide A and Scytophycin C. A Highly Stereocontrolled Synthesis of (‐)‐Pre‐Swinholide A.
Authors: PATERSON I. , CUMMING J. G. , SMITH J. D. , WARD R. A. , YEUNG K.‐S.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis via Ultrasound: A Very Short and Convenient Synthesis of (Z) and (E)‐Heneicos‐6‐en‐11‐ones.
Authors: TREHAN I. R. , SINGH J. , ARORA A. K. , KAUR J. , KAD G. L.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Catalysis by Structurally Designed Surfaces
Authors: IWASAWA Y.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Enzyme Chemistry
Authors: SUTHERLAND A. G.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Photocyclization of Arylethylenes: Mechanism and Scope of the Reactions
Authors: LAPOUYADE R.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Enzyme‐Mimetic C‐C and C‐N Bond Formations
Authors: ENDERS D.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Theoretical Organic Chemistry
Authors: MCDOUALL J. J. W.
Published: August 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Critical properties prediction based on a quartic equation of state
Authors: Zang Lian‐yun , Zhu Qing‐li , Yun Zhi
Published: August 2010

A quartic equation of state (EOS) [Yun et al., Fluid Phase Equilibr. 2001; 187–188: 275–298] is used for predicting critical properties of pure substances. Parameters in the EOS are rewritten as functions of temperature (T in K), and there are totally eleven substance‐specific constants in the functions for each substance. Data of few experimental points including saturated vapour pressure, saturated liquid molar volume and evaporation enthalpy at some temperatures are required in this study to determine the substance‐specific constants in the EOS, while the knowledge of molecular structure is not necessary.

Une équation d'état quartique (Yun et coll., «A new quartic equation of state,» Fluid Phase Equilib 187–188, 275–298 (2001)) est utilisée pour prédire les propriétés critiques des substances pures. Les paramètres de l'équation d'état sont réécrits comme des fonctions de la température (T, en K) et il y a un total de onze constantes propres aux substances dans les fonctions pour chaque substance. Les données de quelques points expérimentaux comprenant la pression de vapeur saturante, le volume molaire de la solution saturée et l'enthalpie d'évaporation à certaines températures sont requises dans cette étude dans le but de déterminer les constantes propres aux substances dans l'équation d'état, alors que la connaissance de la structure moléculaire n'est pas nécessaire. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering
Wavelet‐adaptive solvers on multi‐core architectures for the simulation of complex systems
Authors: Rossinelli Diego , Hejazialhosseini Babak , Bergdorf Michael , Koumoutsakos Petros
Published: August 2010

We build wavelet‐based adaptive numerical methods for the simulation of advection‐dominated flows that develop multiple spatial scales, with an emphasis on fluid mechanics problems. Wavelet‐based adaptivity is inherently sequential and in this work we demonstrate that these numerical methods can be implemented in software that is capable of harnessing the capabilities of multi‐core architectures while maintaining their computational efficiency. Recent designs in frameworks for multi‐core software development allow us to rethink parallelism as task‐based, where parallel tasks are specified and automatically mapped onto physical threads. This way of exposing parallelism enables the parallelization of algorithms that were considered inherently sequential, such as wavelet‐based adaptive simulations. In this paper we present a framework that combines wavelet‐based adaptivity with the task‐based parallelism. We demonstrate the promising performance obtained by simulating various physical systems on different multi‐core architectures using up to 16 cores. Copyright © 2010 John Wiley & Sons, Ltd.
Spatial embedding and the structure of complex networks
Authors: Bullock S. , Barnett L. , Di Paolo E. A.
Published: August 2010

We review and discuss the structural consequences of embedding a random network within a metric space such that nodes distributed in this space tend to be connected to those nearby. We find that where the spatial distribution of nodes is maximally symmetrical some of the structural properties of the resulting networks are similar to those of random nonspatial networks. However, where the distribution of nodes is inhomogeneous in some way, this ceases to be the case, with consequences for the distribution of neighborhood sizes within the network, the correlation between the number of neighbors of connected nodes, and the way in which the largest connected component of the network grows as the density of edges is increased. We present an overview of these findings in an attempt to convey the ramifications of spatial embedding to those studying real‐world complex systems. © 2010 Wiley Periodicals, Inc. Complexity 16: 20–28, 2010
Interaction between a dislocation and monovalent anion in various alkali halide crystals
Authors: Kohzuki Y.
Published: August 2010

It was investigated from (L0/L)2 versus ϕ0 curve that the Friedel relation between the effective stress and the average length of dislocation segments, L, is appropriate for the interaction between a dislocation and the monovalent anion in various alkali halides single crystals (NaCl: Br‐, NaBr: Cl‐ or I‐, KCl: Br‐or I‐, and RbCl: Br‐ or I‐). Here, L0 represents the average spacing of monovalent anions on a slip plane and ϕ0 is the bending angle at which the dislocation breaks away from the anion at the temperature of 0 K. This is because the anions are the weak obstacles such as impede the dislocation at ϕ0 above about 150 degrees, where the Friedel relation agrees with the Fleischer one (L02 = L2(π–ϕ0)/2). Furthermore, the values of (L /L0) were found to be within 4.05 to 5.87 for the crystals. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impedance analysis and high temperature conduction mechanism of flux grown Pb(Zn1/3Nb2/3)0.91Ti0.09O3 single crystal
Authors: Singh B. K. , Kumar B.
Published: August 2010

The electrical properties of Pb(Zn1/3 Nb2/3)0.91Ti0.09O3 single crystals over a wide range of frequencies (20 Hz to 2 MHz) and temperature (30 to 490 °C) were studied using impedance spectroscopic technique. A strongly frequency dependant Debye type relaxation process in crystals was observed. The activation energy for relaxation was found to be 1.72 eV. The nature of Cole‐Cole plot reveals the contribution of only grain (bulk) effect in the sample. The temperature dependant conductivity was found to different in different temperature regions, which shows the presence of different carrier for conduction. The activation energy for conduction in the order of 1.69 eV suggested that the conduction process in higher temperature region is governed by the presence of lead vacancy defect in the sample. Further, the negative temperature thermistor behaviour of the system was explored and various associated parameters were calculated. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Minimal Euclidean distance‐inspired optimal and suboptimal modulation schemes for vector OFDM system
Authors: Huang Xin‐Lin , Wang Gang , Hu Fei
Published: August 2010

In single‐input and single‐output (SISO) systems, the vector orthogonal frequency division multiplexing (VOFDM) has been proposed to reduce the cyclic prefix length, whereas the precoded OFDM has been proposed to overcome spectral‐null channels. However, VOFDM does not show robustness to spectral‐null channels, and the precoded OFDM system has expanded data rate. This work proposes the optimal and suboptimal modulation schemes in vector OFDM systems with knowledge of the channel impulse response (CIR) in order to reduce the bit error rate (BER). As the BER performance is determined by the diversity of the received vector symbols, the proposed modulation scheme mainly concerns the minimal Euclidean distance of all the possible received vector symbols. Through the analysis of the vector input and output equations, we derive the Euclidean distance of the received vector symbols. Then, we propose optimal and suboptimal modulation schemes in VOFDM system to overcome spectral‐null channels by improving the minimal Euclidean distance. Both theoretical performance analysis and simulation results are presented to show the robustness of our system. Finally, we conduct a compared performance analysis of the proposed VOFDM system, the conventional precoded OFDM system, and the conventional VOFDM system. Copyright © 2010 John Wiley & Sons, Ltd.
Recombinant EDA or Sonic Hedgehog rescue the branching defect in Ectodysplasin A pathway mutant salivary glands in vitro
Authors: Wells K.L. , Mou C. , Headon D.J. , Tucker A.S.
Published: August 2010

Hypohidrotic ectodermal dysplasia (HED) is characterized by defective ectodermal organ development. This includes the salivary glands (SGs), which have an important role in lubricating the oral cavity. In humans and mice, HED is caused by mutations in Ectodysplasin A (Eda) pathway genes. Various phenotypes of the mutant mouse EdaTa/Ta, which lacks the ligand Eda, can be rescued by maternal injection or in vitro culture supplementation with recombinant EDA. However, the response of the SGs to this treatment has not been investigated. Here, we show that the submandibular glands (SMGs) of EdaTa/Ta mice exhibit impaired branching morphogenesis, and that supplementation of EdaTa/Ta SMG explants with recombinant EDA rescues the defect. Supplementation of EdardlJ/dlJ SMGs with recombinant Sonic hedgehog (Shh) also rescues the defect, whereas treatment with recombinant Fgf8 does not. This work is the first to test the ability of putative Eda target molecules to rescue Eda pathway mutant SMGs. Developmental Dynamics 239:2674–2684, 2010. © 2010 Wiley‐Liss, Inc.
Developmental expression of Bdnf, Ntf4/5, and TrkB in the mouse peripheral taste system
Authors: Huang Tao , Krimm Robin F.
Published: August 2010

Brain‐derived neurotrophic factor (BDNF), neurotrophin‐4 (NT4), and their TrkB receptor regulate taste system development. To determine where and when gustatory neurons come in contact with these important factors, temporospatial expression patterns of Bdnf, Ntf4/5, and TrkB in the peripheral taste system were examined using RT‐PCR. In the lingual epithelium, Ntf4/5 mRNA expression was higher than that of Bdnf at embryonic day 12.5 (E12.5), and the expression of both factors decreased afterwards. However, Ntf4/5 expression decreased at an earlier age than Bdnf.
Bdnf and Ntf4/5 are expressed in equal amounts at E12.5 in geniculate ganglion, but Bdnf expression increased from E14.5 to birth, whereas Ntf4/5 expression decreased. These findings indicate that NT4 functions at early embryonic stages and is derived from different sources than Bdnf. TrkB expression in the geniculate ganglion is robust throughout development and is not a limiting factor for neurotrophin function in this system. Developmental Dynamics 239:2637–2646, 2010. © 2010 Wiley‐Liss, Inc.
Three‐Electrode‐Integrated Sensor into a Micropipette Tip
Authors: da Silva Rodrigo Amorim Bezerra , Rabelo Adriano César , Munoz Rodrigo Alejandro Abarza , Richter Eduardo Mathias
Published: August 2010

This work describes the construction, characterization, and application of a three‐electrode‐integrated sensor into a micropipette tip. The three electrodes (working, pseudoreference and counter) are positioned at the end of a micropipette tip. The working electrode (graphite composite or gold microfiber) is placed inside the micropipette tip and the pseudo‐reference and counter electrodes outside (diametrically opposed sides). This approach is candidate for portable applications and allows the analysis and studies in low‐volume solutions (ca. 10 µL) which are useful for waste minimization and development of clean analytical methods. In addition, the three‐electrode‐integrated sensor can be easy used as detector in flow injection system through its direct joining at the end of polyethylene tubing of the FIA system.
Recombinant clotting factor VIII concentrates: Heterogeneity and high‐purity evaluation
Authors: D'Amici Gian Maria , Timperio Anna Maria , Gevi Federica , Grazzini Giuliano , Zolla Lello
Published: August 2010

Factor VIII is an important glycoprotein involved in hemostasis. Insertion of expression vectors containing either the full‐length cDNA sequence of human factor VIII (FLrFVIII) or B‐domain deleted (BDDrFVIII) into mammalian cell lines results in the production of recombinant factor VIII (rFVIII) for therapeutic usage. Three commercially available rFVIII concentrates (Advate®, Helixate NexGen® and Refacto®), either FLrFVIII or BDDrFVIII, were investigated by 1‐ and 2‐DE and MS. The objective of this study was to compare the heterogeneity and the high purity of both rFVIII preparations before and after thrombin digestion. In particular, the 2‐D gel was optimized to better highlight the presence of contaminants and many unexpected proteins. Recombinant strategies consisting of insertion of expression vectors containing BDDrFVIII and FLrFVIII resulted in homogeneous and heterogeneous protein products, respectively, the latter consisting in a heterogeneous mixture of various B‐domain‐truncated forms of the molecule. Thrombin digestion of all the three rFVIII gave similar final products, plus one unexpected fragment of A2 domain missing 11 amino acids. Regarding the contaminants, Helixate NexGen® showed the presence of impurities, such as Hsp70 kDa, haptoglobin and proapolipoprotein; Refacto® showed glutathione S‐transferase and β‐lactamase, whereas Advate® apparently did not contain any contaminants. The proteomic approach will contribute to improving the quality assurance and manufacturing processes of rFVIII concentrates. In this view, the 2‐DE is mandatory for revealing the presence of contaminants.
Employing Volterra filters in the ADPCM technique for speech coding: a comprehensive investigation
Authors: Alipoor Gh. , Savoji M. H.
Published: August 2010

Although linear filters are useful in a various applications in the context of speech processing, there are several evidences for existence of nonlinearity in speech signals. Our main aim is to launch a comprehensive investigation into the exploitation of nonlinear Volterra filters in the context of the ADPCM‐based speech coding technique, using two methods of forward prediction, based on the LS criterion, and backward prediction, based on both LMS and RLS adaptation algorithms. In any case, after solving some innate problems, for example, ill‐conditioning and instability, schemes for optimum exploitation of nonlinear prediction are developed and simulation results are provided, tested with several performance criteria. With forward prediction a scheme is developed to detect and flag those frames for which, after stabilizing, including the quadratic predictor is beneficial. Scalar and vector quantisation methods are used for quantising the residual signal and the filter parameters, respectively. The results show that using this scheme a negligible improvement (up to 0.62 dB in the SNR) can be achieved, in spite of the increase in bit rate and complexity. With backward prediction two frame‐based schemes are developed in which for each frame, after examining a set of quadratic filters, the best filter in the sense of the best quality of the reconstructed speech is selected. The ultimate schemes result in an improvement of up to 1.5 dB in the overall SNR of the reconstructed speech at the cost of a slight increase in the bit‐rate, a short delay and a demanding increase in the complexity. Copyright © 2010 John Wiley & Sons, Ltd.
Liposomal incorporation of rose essential oil by a supercritical process
Authors: Wen Zhen , You Xinkui , Jiang Linzhi , Liu Bo , Zheng Zongkun , Pu Yitao , Cheng Bo
Published: August 2010

This study was conducted to investigate the possibility of applying a supercritical process to incorporate rose essential oil into liposomes. By rapid expansion of the supercritical solution of the lipid materials and rose essential oil into a surfactant solution, the liposomes entrapping rose essential oil were formed. In this process, the surfactant provided stabilization for liposomes by preventing flocculation and agglomeration resulting from particle collisions during the spraying process. The encapsulating performance and particle size distribution of liposomes could be controlled by changing pre‐expansion and expansion processing conditions. According to analysis by differential scanning calorimetry (DSC), the morphology and particle size, the liposomes formed were double‐layered vesicles entrapping the rose essential oil with a particle size of less than 100 nm. Compared with the liposomes prepared by thin‐film dispersion, the liposomes formed by the supercritical process exhibited higher encapsulation efficiency and smaller particle size with a unimodal distribution, which achieved the standards of Chinese Pharmacopoeia. The results suggest the supercritical process facilitated a more controllable operation for self‐assembly of liposomes incorporating heat‐sensitive components from natural products in the CO2 medium. Copyright © 2010 John Wiley & Sons, Ltd.
Isolation of new constituents with a formyl group from the heartwood of Santalum album L.
Authors: Hasegawa Toshio , Toriyama Takeshi , Ohshima Naoki , Tajima Yuji , Mimura Ikuyo , Hirota Kazuki , Nagasaki Yuya , Yamada Hideo
Published: August 2010

Sandalwood (Santalum album L.) is a traditional incense, and its essential oil is used in fragrances. The hexane extract from Indian sandalwood chips had a sandalwood odour similar to sandalwood chips, but it clearly differed from that of commercial essential oil. By fractional distillation of the extract under reduced pressure, a fraction was obtained that had a sandalwood‐like odour and contained several unknown formyl compounds as the main constituents. Santalyl formates were isolated as new components from this fraction by chromatography and characterized by 1H‐ and 13C‐NMR spectroscopy. These constituents were less abundant in the commercial essential oil than in the hexane extract. Santalyl formates were synthesized from the corresponding alcohols.
Inference for regression models with errors from a non‐invertible MA(1) process
Authors: Chen Mei‐Ching , Davis Richard A. , Song Li
Published: August 2010

This paper considers maximum likelihood estimation in a regression model when the errors follow a first‐order moving average model which is non‐invertible or nearly non‐invertible. The latter corresponds to a moving average parameter θ that is equal to or close to 1. The joint limiting distribution of the maximum likelihood estimators b̂ and $\hat\theta$ of the regression parameter vector b and the moving average parameter θ is described. Unlike the case with standard time series models, the limiting distribution of b̂ depends on whether or not θ is being estimated. Specifically, the limit distribution of b̂ is non‐normal if θ is also being estimated and is normal if θ is unestimated and equal to 1. The asymptotic behavior of the generalized likelihood ratio statistic for testing θ = 1 vs. θ < 1 is also studied and shown to perform well compared to the locally best invariant unbiased test of Tanaka (1990). We also indicate extensions to seasonal moving average models with a unit root. Copyright © 2010 John Wiley & Sons, Ltd.
Variety in vegetable and fruit consumption and risk of bladder cancer in the European Prospective Investigation into Cancer and Nutrition
Authors: Büchner Frederike L. , Bueno‐de‐Mesquita H. Bas , Ros Martine M. , Kampman Ellen , Egevad Lars , Overvad Kim , Tjønneland Anne , Roswall Nina , Clavel‐Chapelon Françoise , Boutron‐Ruault Marie‐Christine , Touillaud Marina , Kaaks Rudolf , Chang‐Claude Jenny , Boeing Heiner , Weikert Steffen , Trichopoulou Antonia , Naska Ada , Benetou Vicky , Palli Domenico , Sieri Sabina , Vineis Paolo , Tumino Rosario , Panico Salvatore , van Duijnhoven Fränzel J.B. , Peeters Petra H.M. , van Gils Carla H. , Lund Eiliv , Gram Inger T. , Sánchez Maria‐José , Jakszyn Paula , Larrañaga Nerea , Ardanaz Eva , Navarro Carmen , Rodríguez Laudina , Manjer Jonas , Ehrnström Roy , Hallmans Göran , Ljungberg Börje , Key Tim J. , Allen Naomi E. , Khaw Kay‐Tee , Wareham Nicholas , Slimani Nadia , Jenab Mazda , Boffetta Paolo , Kiemeney Lambertus A.L.M , Riboli Elio
Published: August 2010

Recent research does not show an association between fruit and vegetable consumption and bladder cancer risk. None of these studies investigated variety in fruit and vegetable consumption, which may capture different aspects of consumption. We investigated whether a varied consumption of vegetables and fruits is associated with bladder cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Detailed data on food consumption and complete follow‐up for cancer incidence were available for 452,185 participants, who were recruited from ten European countries. After a mean follow‐up of 8.7 years, 874 participants were diagnosed with bladder cancer. Diet diversity scores (DDSs) were used to quantify the variety in fruit and vegetable consumption. Multivariable Cox proportional hazard models were used to assess the effect of the DDSs on bladder cancer risk. There was no evidence of a statistically significant association between bladder cancer risk and any of the DDSs when these scores were considered as continuous covariates. However, the hazard ratio (HR) for the highest tertile of the DDS for combined fruit and vegetable consumption was marginally significant compared to the lowest (HR = 1.30, 95% confidence interval: 1.00–1.69, p‐trend = 0.05). In EPIC, there is no clear association between a varied fruit and vegetable consumption and bladder cancer risk. This finding provides further evidence for the absence of any strong association between fruit and vegetable consumption as measured by a food frequency questionnaire and bladder cancer risk.
Characterization of E2F3a function in HepG2 liver cancer cells
Authors: Li Wei , Ni Guo‐Xin , Zhang Ping , Zhang Zheng‐Xi , Li Wei , Wu Qiang
Published: August 2010

E2F3a is a transcription factor that has been shown to be overexpressed in liver cancer tissues. To characterize the function of E2F3a in hepatocellular carcinoma (HCC), effects of ectopic overexpression of E2F3a on cell cycle, apoptosis, and gene expression of HepG2 cells were studied. E2F3a significantly enhances the apoptotic rate of HepG2 cells by 33% but only has minor effects on cell proliferation. By using microarray analyses, we identified 162 target genes (160 upregulated and 2 downregulated) of the E2F3a. Differential expression of 11 genes was further confirmed by real‐time PCR. Eight of these 11 genes, including XAF1, CEACAM1, STAT1, ATF3, TNFSF10, KLF6, CLDN1, and TAP1, were confirmed to be upregulated by more than twofold. Functional enrichments of differentially expressed genes retrieved 21 apoptosis‐related genes and 32 transcriptional regulation‐related genes. These results suggest that E2F3a induces apoptosis in HepG2 cells and plays important roles in regulating transcription. Finally, positive correlation was found between E2F3a and CEACAM1 mRNA levels in clinically well‐differentiated human HCC specimens. J. Cell. Biochem. 111: 1244–1251, 2010. © 2010 Wiley‐Liss, Inc.
Modulation of GEF‐H1 Induced Signaling by Heparanase in Brain Metastatic Melanoma Cells
Authors: Ridgway Lon D. , Wetzel Michael D. , Marchetti Dario
Published: August 2010

Mechanisms of brain metastatic melanoma (BMM) remain largely unknown. Understanding the modulation of signaling pathways that alter BMM cell invasion and metastasis is critical to develop new therapies for BMM. Heparanase has been widely implicated in cancer and is the dominant mammalian endoglycosidase which degrades heparan sulfate chains of proteoglycans (HSPG) including syndecans (SDCs). Recent findings also indicate that heparanase possesses non‐enzymatic functions in its latent form. We hypothesized that extracellular heparanase modulates BMM cell signaling by involving SDC1/4 carboxy terminal—associated proteins and downstream targets. We digested BMM cell surface HS with human recombinant active or latent heparanase to delineate their effects on cytoskeletal dynamics and cell invasiveness. We identified the small GTPase guanine nucleotide exchange factor‐H1 (GEF‐H1) as a new component of a SDC signaling complex that is differentially expressed in BMM cells compared to corresponding non‐metastatic counterparts. Second, knockdown of GEF‐H1, SDC1, or SDC4 decreased BMM cell invasiveness and GEF‐H1 modulated small GTPase activity of Rac1 and RhoA in conjunction with heparanase treatment. Third, both active and latent forms of heparanase affected Rac1 and RhoA activity; notably increasing RhoA activity. Both forms of heparanase were found to mediate the expression and subcellular localization of GEF‐H1, and treatment of BMM with latent heparanase modulated SDC1/4 gene expression. Finally, treatment with exogenous heparanase downregulated BMM cell invasion. These studies indicate the relevance of heparanase signaling pathways in BMM progression, and provide insights into the molecular mechanisms regulating HSPG signaling in response to exogenous heparanase. J. Cell. Biochem. 111: 1299–1309, 2010. © 2010 Wiley‐Liss, Inc.
SIRT1 modulates high‐mobility group box 1‐induced osteoclastogenic cytokines in human periodontal ligament cells
Authors: Kim Young‐Suk , Lee Young‐Man , Park Jae‐Sang , Lee Suk‐Keun , Kim Eun‐Cheol
Published: August 2010

Bone resorptive cytokines contribute to bone loss in periodontal disease. However, the involvement of SIRT1 in high‐mobility group box 1 (HMGB1)‐induced osteoclastic cytokine production remains unknown. The aim of this study was to investigate the role of SIRT1 in the responses of human periodontal ligament cells to HMGB1 and to identify the underlying mechanisms. The effect of HMGB1 on osteoclastic cytokine expression and secretion, and the regulatory mechanisms involved were studied by ELISA, reverse transcription‐polymerase chain reaction, and Western blot analysis. HMGB1 upregulated the mRNA expression levels of the osteoclastic cytokines tumor necrosis factor (TNF)‐α, interleukin (IL)‐1β, IL‐6, IL‐11, and IL‐17. In addition, HMGB1 upregulated RANKL mRNA expression, and SIRT1 mRNA and protein expression. The upregulation of these cytokines by HMGB1 was attenuated by pretreatment with inhibitors of p38 mitogen‐activated protein kinase and NF‐κB, as well as neutralizing antibodies against Toll‐like receptors 2 and 4. Inhibition of SIRT1 by sirtinol or SIRT1 siRNA blocked the HMGB1‐stimulated expression of RANKL and cytokines. These results suggest that the inhibition of SIRT1 may attenuate HMGB1‐mediated periodontal bone resorption through the modulation of osteoclastogenic cytokine levels in human periodontal ligament cells. J. Cell. Biochem. 111: 1310–1320, 2010. © 2010 Wiley‐Liss, Inc.
Intramolecular interactions of L‐phenylalanine: Valence ionization spectra and orbital momentum distributions of its fragment molecules
Authors: Ganesan Aravindhan , Wang Feng , Falzon Chantal
Published: August 2010

Intramolecular interactions between fragments of L‐phenylalanine, i.e., phenyl and alaninyl, have been investigated using dual space analysis (DSA) quantum mechanically. Valence space photoelectron spectra (PES), orbital energy topology and correlation diagram, as well as orbital momentum distributions (MDs) of L‐phenylalanine, benzene and L‐alanine are studied using density functional theory methods. While fully resolved experimental PES of L‐phenylalanine is not yet available, our simulated PES reproduces major features of the experimental measurement. For benzene, the simulated orbital MDs for 1e1g and 1a2u orbitals also agree well with those measured using electron momentum spectra. Our theoretical models are then applied to reveal intramolecular interactions of the species on an orbital base, using DSA. Valence orbitals of L‐phenylalanine can be essentially deduced into contributions from its fragments such as phenyl and alaninyl as well as their interactions. The fragment orbitals inherit properties of their parent species in energy and shape (ie., MDs). Phenylalanine orbitals show strong bonding in the energy range of 14‐20 eV, rather than outside of this region. This study presents a competent orbital based fragments‐in‐molecules picture in the valence space, which supports the fragment molecular orbital picture and building block principle in valence space. The optimized structures of the molecules are represented using the recently developed interactive 3D‐PDF technique. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011
Synthesis of novel carbazolyl‐oxazolone derivatives and their spectroscopic properties
Authors: Gündoğdu Cevher , Topkaya Derya , Öztürk Gülsiye , Alp Serap , Ergün Yavuz
Published: August 2010

magnified image

Novel carbazolyl‐oxazolones, 3a, 3b, 3c, 3d, were synthesized with 3‐[N‐(2‐hydroxycarbonylmethyl)‐carboxamide]‐4‐methyl‐9H‐carbazole and several aryl aldehydes for the first time. Photo physical characterization of synthesized 2‐carbazolyl‐4‐arylidene‐5‐oxazolones (3a, 3b, 3c, 3d) in dichloromethane, chloroform, and toluene was performed. J. Heterocyclic Chem., (2010).
Up‐regulation of erythropoietin receptor by nitric oxide mediates hypoxia preconditioning
Authors: Chen Zhi‐Yong , Wang Li , Asavaritkrai Pundit , Noguchi Constance Tom
Published: August 2010

Erythropoietin (Epo), known to stimulate erythroid progenitor cell survival, proliferation, and differentiation, has been shown to be neuroprotective against brain ischemia in animal models. Both Epo and Epo receptor (EpoR) are expressed in the brain and are up‐regulated by hypoxia. Brain Epo signaling can stimulate neural cell survival and prevent neuron apoptosis. Neurons from EpoR null mice exhibit marked increased sensitivity to hypoxia. In endothelial cells, Epo has been shown to stimulate nitric oxide (NO) production, particularly at low pO2. We found here that the EpoR expression on neural cells and Epo's neuroprotective effect were regulated by NO. Hypoxia increased NO production as well as EpoR expression, and inhibition of NOS activity reduced the proportion of EpoR‐expressing neurons induced at low pO2. Conversely, addition of NO donor to cultures grown under normoxia induced EpoR. Similarly, NO donor increased EpoR promoter activity in a reporter gene assay, suggesting that NO regulates EpoR at the transcription level. Preincubation of neurons with NO results in induction of EpoR, which gives rise to protection against hypoxia even in the absence of exogenous Epo, although at high concentration NO is toxic. These data provide evidence of a role for NO in Epo activity in brain and suggest links between NO production, EpoR expression, and Epo signaling in neuroprotection. Published 2010 Wiley‐Liss, Inc.
L10p and P158DEL DJ‐1 mutations cause protein instability, aggregation, and dimerization impairments
Authors: Ramsey Chenere P. , Giasson Benoit I.
Published: August 2010

A variety of mutations in the gene encoding DJ‐1 protein cause autosomal recessive early‐onset parkinsonism. Recently, a novel pathogenic homozygous DJ‐1 missense mutation resulting in the L10P amino acid substitution was reported. In a separate study, a novel homozygous mutation resulting in the deletion of DJ‐1 residue P158 was also reported to be causative of disease. The specific effects of the novel L10P and P158DEL mutations on protein function have not been studied. Here, L10P and P158DEL DJ‐1 proteins were assessed for protein stability, dimerization, solubility, subcellular localization, and protective function in comparison with WT and the L166P DJ‐1 pathogenic variant. It was discovered that, compared with WT protein, L10P, L166P, and P158DEL DJ‐1 variants exhibited dramatically reduced protein stabilities. Degradation of each of the pathogenic mutants appeared to be mediated in part by the proteasome. Interestingly, unlike L166P DJ‐1, the L10P and P158DEL DJ‐1 variants retained the ability to dimerize with WT DJ‐1 protein; however, neither of these mutants was able to form homodimers. Additionally, the L10P, L166P, and P158DEL DJ‐1 variants exhibited altered profiles on size‐exclusion chromatography and demonstrated reduced solubilities in comparison with WT protein, and the latter aberration could be exacerbated in the presence of MG‐132. Furthermore, cells stably expressing L10P DJ‐1 were more vulnerable to treatments with proteasome inhibitors, suggesting that L10P DJ‐1 may be toxic to cells under conditions of proteasome stress. Taken together, these findings suggest that diverse aberrant mechanisms, including alterations in protein stability and protein folding, are associated with the pathogenicity of the L10P and P158DEL DJ‐1 variants. © 2010 Wiley‐Liss, Inc.
Mutation of iceA in Helicobacter pylori compromised IL‐8 induction from human gastric epithelial cells
Authors: Ma Yi Jun , Duan Guang Cai , Zhang Rong Guang , Fan Qing Tang , Zhang Wei Dong
Published: August 2010

IceA of Helicobacter pylori (H. pylori) has been suggested as a virulence factor for the bacteria, but its pathogenic role remains unelucidated. Here, we examined the effect of iceA mutation on the secretion of IL‐8 by human gastric epithelial cells. We also investigated whether the changes in IL‐8 production caused by iceA mutation were associated with impaired adherence of H. pylori to the epithelial cells or with impaired apoptosis of these cells. The iceA mutant strain was constructed from wildtype H. pylori strain by insertional mutagenesis of iceA. The human gastric epithelial cells SGC7901 were infected with wildtype or mutant H. pylori for appropriate lengths of time. The adherence of the bacteria to the epithelial cells was examined by fluorescent microscopy using an anti‐H. pylori antibody and flow cytometry. The apoptosis of the epithelial cells was studied by annexin‐V staining and flow cytometry. The production of IL‐8 by SGC 7901 cells was determined by ELISA. We found that iceA mutation was associated with significantly impaired production of IL‐8 from the epithelial cells, which was not due to impaired adherence by the bacteria to the epithelial cells as wildtype and mutant H. pylori exhibited similar levels of binding to the epithelial cells. Furthermore, inactivation of iceA did not affect the apoptotic cell death of SGC7901. Our findings indicate that iceA may contribute to the pathogenicity of H. pylori by modulating the production of IL‐8 by host epithelial cells. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimization of laccase production by Pleurotus ostreatus IMI 395545 using the Taguchi DOE methodology
Authors: Periasamy Rathinasamy , Palvannan Thayumanavan
Published: August 2010

Production of laccase using a submerged culture of Pleurotus orstreatus IMI 395545 was optimized by the Taguchi orthogonal array (OA) design of experiments (DOE) methodology. This approach facilitates the study of the interactions of a large number of variables spanned by factors and their settings, with a small number of experiments, leading to considerable savings in time and cost for process optimization. This methodology optimizes the number of impact factors and enables to calculate their interaction in the production of industrial enzymes. Eight factors, viz. glucose, yeast extract, malt extract, inoculum, mineral solution, inducer (1 mM CuSO4) and amino acid (l‐asparagine) at three levels and pH at two levels, with an OA layout of L18 (21 × 37) were selected for the proposed experimental design. The laccase yield obtained from the 18 sets of fermentation experiments performed with the selected factors and levels was further processed with Qualitek‐4 software. The optimized conditions shared an enhanced laccase expression of 86.8% (from 485.0 to 906.3 U). The combination of factors was further validated for laccase production and reactive blue 221 decolorization. The results revealed an enhanced laccase yield of 32.6% and dye decolorization up to 84.6%. This methodology allows the complete evaluation of main and interaction factors. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Do adolescents know when they need help in the aftermath of war?
Authors: Schiff Miriam , Pat‐Horenczyk Ruth , Benbenishty Rami , Brom Danny , Baum Naomi , Astor Ron Avi
Published: August 2010

This study examined Israeli Arab and Jewish students' reports on needing help, a year after the Second Lebanon War and whether students' requests for support were associated with posttraumatic distress. The representative sample included 1,800 Jewish and 2,351 Arab students, grades 7–11. The questionnaires included items regarding (a) exposure to wartime events and other negative life events, (b) measures of posttraumatic stress disorder, and (c) needing help. The results showed that about 30% of the students reported needing help from any source (e.g., parents, peers) in the aftermath of the war. Arab students were more likely to report needing help than Jewish students. The students who reported needing help experienced higher levels of posttraumatic symptoms.
The Joseph H. Ogura lecture: Teaching and learning—then and now
Authors: Fried Marvin P.
Published: August 2010

Education, the process of teaching and learning, has remained a passion of those in academic medicine. The context has changed over time, but the skills required are universal. The goal of these efforts is training the finest otolaryngologists who deliver the best care to their patients and build the future or our specialty. Laryngoscope, 2011
Analysis of skeletal mandibular abnormalities associated with cervicofacial lymphatic malformations
Authors: O Teresa M. , Kwak Roy , E. Portnof Jason , Berke Daryl M. , Lipari Brian , Waner Milton
Published: August 2010

Objectives/Hypothesis

Many children with cervicofacial lymphatic malformations have facial skeletal abnormalities. This study qualitatively and quantitatively evaluated these bony mandibular abnormalities.

Study Design

Retrospective chart review.

Methods

Patients with craniofacial lymphatic malformations presenting to a vascular anomalies center during a 2‐year period were included. An age‐matched control population was found on the Picture Archiving and Communication System database. Three‐dimensional reconstructions were created from computed tomography and magnetic resonance imaging. Qualitative observations and quantitative measurements were taken of the gonial angle, mandibular anterior dentoalveolar height, and anterior condylar displacement.

Results

There were 23 controls. A total of 21 patients with “beard” distribution malformations were studied; 10 had unilateral and 11 had bilateral disease.

Qualitatively, a few patterns emerged: outward ramal flaring, anterior displacement of the mandible, relative ipsilateral facial “hypertrophy,” and anterior positioning of the maxilla and orbit. The open‐bite deformity was a common finding leading to malocclusion and oral incompetence. Quantitatively, in 67 nondiseased sides, the average gonial angle was 131 degrees (standard deviation [SD] = 6.8), whereas in 32 diseased sides, the average angle was 152 degrees (SD = 14.0, P < 3.8E‐09). With half‐beard malformations, the diseased side averaged 153.9 and the nondiseased side averaged 140.8 (P = .008). The average condylar displacement was 8.5 mm versus 5.9 mm (diseased vs. nondiseased), and the average mandibular dentoalveolar height to face ratio was 0.37 (control = 0.34).

Conclusions

Cervicofacial lymphatic malformations in the “beard” distribution are associated with significant bony abnormalities leading to both functional and aesthetic sequelae. Our study is the first quantitative analysis of these changes. This is the first step in planning for dentofacial orthopedics, orthodontics, and orthognathic surgery. Laryngoscope, 2011
Wet‐Chemical Deposition of Functional Coatings for Bone Implantology
Authors: Nijhuis Arnold W. G. , Leeuwenburgh Sander C. G. , Jansen John A.
Published: August 2010

Since the early 1980s, research on the modification of bone implant surfaces by applying coatings has mainly focused on the application of inorganic calcium phosphate (CaP) coatings using physical deposition techniques. Organic components of the extracellular bone matrix, on the other hand, play an essential role in the process of bone healing, but cannot be applied using these physical techniques. Therefore, a recent trend in biomaterials research involves development of novel wet‐chemical deposition techniques for both inorganic and organic coatings. This study reviews the major wet‐chemical coating techniques that are used for the deposition of inorganic CaP coatings and organic biomolecules coatings.

magnified image
Efficient Molecular Weight Control with Trialkylaluminum in Ethylene/Norbornene Copolymerization by [Ph2C(Flu)(3‐MeCp)]ZrCl2/Methylaluminoxane Catalyst
Authors: Tada Tomoyuki , Cai Zhengguo , Nakayama Yuushou , Shiono Takeshi
Published: August 2010

Ethylene/norbornene copolymerizations were conducted with [Ph2C(Flu)(3‐RCp)]ZrCl2 [R: Me (1) or Me3Si (2)], which give alternating EN copolymers. The activity of 1 in the absence of R3Al was approximately twice that of 2 and increased further upon addition of R3Al. Et3Al increased the activity most effectively, and the $\overline {M} _{{\rm n}} $ of the produced polymer decreased from 100 000 to 25 000 g · mol−1. On the other hand, the $\overline {M} _{{\rm n}} $ value increased upon addition of iBu3Al from 100 000 to 209 000 g · mol−1 accompanied by an ≈2.5‐fold increase of activity. Consequently, 1 was found to be one of the most promising complexes for the synthesis of alternating EN copolymers, of which $\overline {M} _{{\rm n}} $ value was efficiently controlled by the kind and the amount of R3Al added.

magnified image
Die Chemie des Heliums
Authors: Cremer Dieter
Published: August 2010

Die Quantenchemie hat sich während der beiden letzten Jahrzehnte zu einem der wichtigsten Teilgebiete der Theoretischen Chemie entwickelt.1) Ursachen dafür sind die ständige Verbesserung quantenchemischer Methoden und vor allem die atemberaubende Weiterentwicklung von Hochleistungscomputern.
Kunststoffe bleiben weiterhin die Hauptträger des Chemie‐Wachstums
Authors: Nachtsheim Hubert
Published: August 2010

Zufriedenheit und Optimismus beherrschten die Stimmung beim Pressegespräch des Verbandes Kunststofferzeugende Industrie (VKE) im „Hessischen Hoff”︁ zu Frankfurt. Der Vorsitzende, Bayer‐Vorstandsmitglied Dr. Helmut Piechota, kam in seinem Statement zur Sache: Die deutschen Kunststofferzeuger haben im Rahmen der guten Konjunktur 1988 ein ausgezeichnetes Ergebnis erwirtschaften können. Piechota: “An den erfreulich gestiegenen Umsätzen und Ergebnissen der deutschen Chemieunternehmen hatten Kunststoffe einen erheblichen Anteil. Sie waren eigentlich die wichtigen Träger des Wachstums.”
Graphitrohrofen‐AAS: auf dem Weg zu absoluter Analyse
Authors: Schlemmer Gerhard
Published: August 2010

20 Jahre nach der kommerziellen Einführung der Graphitrohrofen‐AAS dokumentieren insgesamt fast 10000 Publikationen Anwendungsbreite und Grundlagenverständnis dieser Technik. In vielen Fällen erlaubt das Absorptionssignal einer unbekannten Probe bereits ohne Kalibrierung eine Voraussage über den Analytgehalt mit einer Abweichung von weniger als 20% vom wahren Wert. Modelle erlauben es, den Verlauf von Absorptionssignalen aus physikalischen Daten vorherzusagen. Die zeitlich aufgelöste Extinktion ermöglicht darüber hinaus Aussagen über physikalisch‐chemische Vorgänge an Graphitoberflächen und in der Gasphase einer bis zu 3000 K heißen Meßzelle.
Keine Rechtsgrundlage für die Gentechnik?
Authors: Pohlmann Andreas
Published: August 2010

Der Hessische Verwaltungsgerichtshof (VGH) in Kassel hat am 6. November 1989 mit einer unerwarteten Eilentscheidung den geplanten Versuchsbetrieb der gentechnischen Anlage zur Herstellung von Humaninsulin der Hoechst AG verhindert. In der Entscheidung sind rechtliche Ausführungen grundsätzlicher Art enthalten, die im Ergebnis bedeuten würden, daß bis zum Erlaß eines Gentechnikgesetzes keine gentechnischen Arbeiten mehr durchgeführt werden dürften.
Tagungsberichte
Authors: Stegmann H. B.
Published: August 2010

EPR, Photosynthese und Waldschäden. Eine Untersuchung an Fichten in montanen und urbanen Regionen
Mathematik + Chemie mit Standard–Textprogrammen ?
Authors: Glock B.
Published: August 2010

Wer eines der gängigen Textprogramme – Word oder WordPerfect – besitzt, kann bei nicht allzu hohen Ansprüchen und mit verhältnismäßig geringem Aufwand auch mathematische und/oder chemische Formeln in seine Manuskripte einbauen.