bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of Glutathione and Activation of Immune Functions by Low‐Dose, Whole‐Body Irradiation with γ‐Rays
Authors: Kojima Shuji
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mechanism of Olefin Cycloalumination with Triethylaluminum into Aluminacyclopentanes Using Cp2ZrCl2 as a Catalyst
Authors: Khalilov Leonard M. , Parfenova Ludmila V. , Rusakov Sergey V. , Balaev Aleksandr V. , Dzhemilev Usein M.
Published: January 2007

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Alternative synthetic route to chiral N‐substituted camphor‐derived β‐amino alcohols
Authors: Cheng Gin‐ian , Shei Chun‐tin , Sung Kuangsen
Published: January 2007

An alternative route from (1R)‐(+)‐camphor to chiral N‐substituted camphor‐derived β‐amino alcohol (4b–e) consists of four steps with a total yield of 28%. N‐Alkylation of camphor‐derived β‐amino alcohol (4a) involves condensation and hydride reduction in one pot without isolation of intermediates. Condensation of 4a with aldehydes or ketones generates a mixture of 1,3‐oxazolidines (6) and imino‐alcohols (7), which are reduced to 4b–e by NaBH4. Chirality, 2007. © 2007 Wiley‐Liss, Inc.
One‐ and Two‐Photon Singlet Oxygen Generation with New Fluorene‐Based Photosensitizers
Authors: Andrasik Stephen J. , Belfield Kevin D. , Bondar Mykhailo V. , Hernandez Florencio E. , Morales Alma R. , Przhonska Olga V. , Yao Sheng
Published: January 2007

The spectral properties of new fluorene‐based photosensitizers for efficient singlet oxygen production are investigated at room temperature and 77 K. Two‐photon absorption (2PA) cross‐sections of the fluorene derivatives are measured by the open aperture Z‐scan method. The quantum yields of singlet oxygen generation under one‐ and two‐photon excitation (ΦΔ and 2PAΦΔ, respectively), are determined by the direct measurement of singlet oxygen luminescence at ≈1270 nm. The values of ΦΔ are independent of excitation wavelength, ranging from 0.6–0.9. The singlet oxygen quantum yields under two‐photon excitation are 2PAΦΔ≈1/2ΦΔ, indicating that the two processes exhibit the same mechanism of singlet oxygen production, independent of the mechanism of photon absorption.
Interacting neural networks and the emergence of social structure
Authors: Stoica‐Klüver Christina , Klüver Jürgen
Published: January 2007

The article describes a computational model for the simulation of the emergence of social structure or social order, respectively. The model is theoretically based on the theory of social typifying by Berger and Luckmann. It consists of interacting artificial actors (agents), which are represented by two neural networks, an action net, and a perception net. By mutually adjusting of their actions, the agents are able to constitute a self‐organized social order in dependency of their personal characteristics and certain features of their environment. A fictitious example demonstrates the applicability of the model to problems of extra‐terrestrial robotics. © 2007 Wiley Periodicals, Inc. Complexity 12: 41–52, 2007
Highly Ordered Macroporous Gold Film Formed by CVD Using Monodisperse Polystyrene Spheres as Templates
Authors: Au R. H. W. , Puddephatt R. J.
Published: January 2007

Macroporous gold films have been prepared by chemical vapor deposition using polystyrene spheres as templates. The gold films are prepared by using the CVD precursor complex [AuMe(PMe3)]. In order to effect the CVD at low temperature, the polystyrene spheres are seeded with palladium metal, in order to catalyze the decomposition of the gold precursor complex.
The Synthesis of ZrO2/SiO2 Nanocomposites by the Two‐Step CVD of a Volatile Halogen‐Free Zr Alkoxide in a Fluidized‐Bed Reactor
Authors: Xia W. , Wang Y. , Hagen V. , Heel A. , Kasper G. , Patil U. , Devi A. , Muhler M.
Published: January 2007

ZrO2/SiO2 nanocomposites with Zr loadings in the range 0.88 wt % to 12.2 wt % were prepared by a two‐step metal‐organic (MO)CVD process in a fluidized‐bed reactor with the Zr alkoxide [Zr(OiPr)2(tbaoac)2] as the precursor. The high surface area of silica was hardly diminished by the deposition, and the deposited zirconia species were highly dispersed, as indicated by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) investigations. The XPS data reveal a linear increase of the Zr surface concentration with increasing Zr loading. The high degree of dispersion is attributed to a strong interaction between the zirconia species and the support through the formation of Si‐O‐Zr bonds. Correspondingly, the intensity of the isolated silanol bands detected by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) was found to decrease with increasing Zr loading.
Influence of 4‐ and 6‐color flow cytometers and acquisition/analysis softwares on the determination of lymphocyte subsets in HIV infection
Authors: Ashman M. , Sachdeva N. , Davila L. , Scott G. , Mitchell C. , Cintron L. , Rathore M. , Asthana D.
Published: January 2007

Background and Objectives:

Lymphocyte immunophenotyping provides valuable information for the diagnosis and monitoring of patients with cellular immunodeficiencies, such as HIV/AIDS. In this study, we have assessed the influence of 4‐color and 6‐color flow cytometers, and respective analytical softwares on the enumeration of lymphocytes in HIV infected individuals.

Methods:

The expression of various cell surface markers on lymphocytes was measured from the EDTA blood of 66 HIV infected patients on the FACSCalibur™ (4‐color) and FACSCanto™ (6‐color) flow cytometers. Percentage of lymphocytes expressing a particular cell surface marker was analyzed on FACSCalibur using the Cell Quest Pro™ software (v 5.2), while the analysis on FACSCanto was done using FACSCanto (v 1.0.3) and FACSDiva™ (v 4.1) softwares respectively.

Results:

The data shows significantly higher mean CD3 T‐cell counts on FACSCalibur, Cell Quest Pro (1,864 ± 1,044 cells/μl) as compared to FACSCanto (1,840 ± 1,040 cells/μl) (P < 0.05). The CD4 T‐cell counts were also higher on FACSCalibur, Cell Quest Pro (885 ± 770 cells/μl), and FACSDiva (892 ± 773 cells/μl) versus FACSCanto (867 ± 767 cells/μl) (P < 0.05). FACSCalibur, Cell Quest Pro, and FACSDiva showed similar values except for CD8 T‐lymphocytes where FACSDiva had significantly lower values (P < 0.05). The B‐cell counts were unaffected when either of the instruments or softwares were used, while the natural killer (NK) cells (CD16 + 56 positive cells) showed similar trend like CD3 and CD4 counts with significant differences in the mean cell counts between FACSCalibur, Cell Quest Pro (240 ± 165 cells/μl), and FACSDiva (238 ± 163 cells/μl) versus FACSCanto with higher NK cell counts (260 ± 176 cells/μl).

Conclusions:

The enumeration of lymphocyte subsets was comparable between FACSCalibur, Cell Quest Pro, and FACSDiva, based analysis and it was significantly different than FACSCanto software based analysis. Our observations suggest that FACSDiva software should be preferred over the FACSCanto software for immunophenotyping on FACSCanto flow cytometer and the laboratories should report the instrument and software used for the specimen analysis while reporting immunophenotyping results. © 2007 Clinical Cytometry Society
Thallium Halides – New Aspects of the Stereochemical Activity of Electron Lone Pairs of Heavier Main‐Group Elements
Authors: Mudring Anja‐Verena
Published: January 2007

Density functional theory studies in the linear muffin tin approximation on thallium halides (TlX; X = F, Cl, Br, I) show that structural distortions due to a stereochemically active lone pair of electrons depend crucially on cation–anion interactions. Such distortions do not originate from a 6s–6p hybridisation on the heavy metal as the Tl 6s and 6p states are energetically too far apart to mix directly. In the case of TlF, the Tl 6s and the F 2p states are located in the same energy region, which leads to an efficient interaction that produces strongly antibonding Tl–F states directly below the Fermi level that would destabilize the solid. Minimisation of these unfavourable covalent antibonding interactions is the driving force for structural distortion. In the case of the heavier thallium halides, the growing energetic mismatch between Tl 6s states and X np states leads to weaker covalent interactions. Thus, the compounds become more ionic and high symmetry structures are adopted as covalent interactions play only a minor role. The low symmetry structure of TlI observed at low temperatures is stabilized by attractive metal–metal bonding. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Transition Metal‐Assisted Hydrolysis of Pyrazole‐Appended Organooxotin Carboxylates Accompanied by Ligand Transfer
Authors: Chandrasekhar Vadapalli , Thilagar Pakkirisamy , Senapati Tapas
Published: January 2007

The reaction of the potentially multi‐site coordination ligands [{nBu2SnO2CL}2O]2 (1), [{nBu2SnO2CL′}2O]2 (2), [nBuSn(O)O2CL]6 (3), and [nBuSn(O)O2CL′]6 (4), (L = (Pz)2CH‐); L′ = (3,5‐Me2Pz)2CH‐; Pz = pyrazolyl) with hydrated metal salts leads to the hydrolysis of the organotin carboxylates accompanied by the formation of insoluble organotinoxide/hydroxides and metal complexes. The in situ generated LCOO and L′COO ligands bind to the metal ions. The complexes [Cu(LCOO)2(NO3)2(nBu2Sn((H2O)2)]n[Cu(LCOO)2] (5), [Mg(L′COO)2] (6), [Cu(LCOO)2] (7), and [{(Cu(L′COO)2(Cu(MeOH))3}{ClO4}2]n (8) were isolated and structurally characterized. The solid‐state structure of 5 reveals that two discrete molecules are present in the same asymmetric unit; a heterobimetallic coordination polymer, [Cu(LCOO)2(NO3)2(nBu2Sn((H2O)2)]n and a discrete coordination complex, [Cu(LCOO)2]. The cationic portion of the heterobimetallic compound contains alternate six‐coordinate SnIV and CuII centers bridged by the carboxylate oxygen atoms of the LCOO ligand.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis of Selectively 13C‐Labelled Bilin Compounds
Authors: Makhynya Yevgen , Hussain Zakir , Bauschlicher Tanja , Schwinte Pascale , Siebert Friedrich , Gärtner Wolfgang
Published: January 2007

A series of open‐chain tetrapyrroles, each carrying one or more 13C‐labels in its three ring‐bridging methine groups, were synthesized. These compounds – [5‐, [10‐, and [15‐13C]‐phycocyanobilins (PCB), [10‐13C]‐phytochromobilin, and [10,15‐13C2]‐PCB – were each obtained by a convergent route, starting with the four pyrrole building blocks, with the initial formation of the left and the right halves of the tetrapyrrole separately, followed by a final condensation of the two dipyrrole units to yield the target bilin compound. The 13C‐labels were all inserted as C1‐ or C2‐units prior to the appropriate condensation. The substitution pattern of these bilins on ring A (ethylidene substituent at position 3) allows covalent attachment to the apoprotein of the plant photoreceptor phytochrome. The isotope shift produced by insertion of a 13C‐isotope is demonstrated in the FT‐IR spectra of phytochrome‐incorporated [10‐13C]‐phytochromobilin. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Symmetrical and Nonsymmetrical Liquid Crystalline Oligothiophenes: Convenient Synthesis and Transition‐Temperature Engineering
Authors: Leroy Julie , Boucher Nicolas , Sergeyev Sergey , Sferrazza Michele , Geerts Yves Henri
Published: January 2007

Two approaches to transition‐temperature engineering in liquid crystalline oligothiophenes are described: (i) substitution at the aromatic core with two identical branched alkyl chains and (ii) desymmetrization of the molecule with two alkyl substituents of different length or structure. Key steps in the synthesis of symmetrical and nonsymmetrical terthiophenes and quaterthiophenes involve Suzuki coupling and carbanion alkylation. A well‐adjusted balance between the π–π stacking of the aromatic core and the disorder caused by the peripheral alkyl chains is demonstrated to be important for the control of the thermotropic behavior of oligothiophene mesogens. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Chemo‐Enzymatic Synthesis of All Isomers of 2‐Methylbutane‐1,2,3,4‐tetraol – Important Contributors to Atmospheric Aerosols
Authors: Moen Anders Riise , Ruud Kjersti , Anthonsen Thorleif
Published: January 2007

By a combination of stereospecific osmium catalyzed oxidation of dimethyl citraconate and lipase catalysed enantioselective resolution of the formed dimethyl (2R*,3S*)‐2,3‐dihydroxy‐2‐methylbutanedioate, followed by reduction, (2R,3S)‐ and (2S,3R)‐2‐methylbutane‐1,2,3,4‐tetraol were isolated. Similar reactions starting with dimethyl mesaconate gave the isomers, (2R,3R)‐ and (2S,3S)‐2‐methylbutane‐1,2,3,4‐tetraol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
The capture of fly ash particles using circular and noncircular cross‐section fabric filters
Authors: Sánchez Javier R. , Rodríguez J.M. , Alvaro A. , Estévez A.M.
Published: January 2007

The great interest in the use of fabric filters made of noncircular cross‐section fibers for collecting small coal fly ash particles (Geldart's type‐C particles) can be seen in this study, in which a nonwoven fabric filter made of circular cross‐section polyester fibers was compared with another nonwoven fabric filter made of predominantly trilobal cross‐section polyimide fibers.

The experimental results show that the collection efficiency of the coal fly ash particles of the polyimide fiber filters is higher than that of polyester fiber filters, mainly for particles smaller than 1.2 μm and with a superficial aerosol velocity of 0.1 m/s. Moreover, the pressure drop across the fabric filters made of polyimide fibers is lower than that of the polyester fiber filters.

The influence of the thickness of the polyimide fibers on collection efficiency and pressure drop was also checked, and the results showed that the thinnest fiber fabric filter had the highest collection efficiency, as well as the highest pressure drop. © 2007 American Institute of Chemical Engineers Environ Prog 26:50–58, 2007.
Daily to seasonal cross‐shore behaviour of quasi‐persistent intertidal beach morphology
Authors: Quartel S. , Ruessink B. G. , Kroon A.
Published: January 2007

In this study, an intertidal bar and trough system on the beach of Noordwijk, The Netherlands was monitored over a 15‐month period in order to examine the daily to seasonal sequential cross‐shore behaviour and to establish which conditions force or interrupt this cyclic bar behaviour. The beach morphology (bars and troughs) was classified from low‐tide Argus video images based on surface composition. From the classified images, time series of the landward boundary of the bar and of the trough were extracted. The time series of the alongshore‐averaged boundary positions described sawtooth motion with a period between 1 and 4 months, comprising gradual landward migration followed by abrupt seaward shifts. The abrupt seaward shift appeared to be a morphological reset induced by storm events, which lasted at least 30 h with a large average root‐mean‐square wave height (≥2 m) and offshore surge level (≥0·5 m), and a small trough (<20 m wide) in the pre‐storm beach morphology. The time series of the boundary positions exhibited very little longer (seasonal) scale variability, but somewhat larger smaller (daily) scale variability. The bar boundary was found to be more dynamic than the trough boundary. Copyright © 2007 John Wiley & Sons, Ltd.
An approach for bearing fault detection in electrical motors
Authors: Gülmezoğlu M. Bilginer , Ergin Semih
Published: January 2007

In this paper, a novel approach for fault detection and diagnosis of induction motors is proposed. This approach depends on determination of a common vector for each class, called the common vector approach (CVA). The common vector of each class represents invariant features or common properties of that class. Vibration signals measured from the rotor ball bearings of an induction motor are used in the experimental study. Experimental results indicate that the proposed approach can be efficiently used for the analysis of faulty conditions in induction motors. Copyright © 2007 John Wiley & Sons, Ltd.
Pricing American exchange options in a jump‐diffusion model
Authors: Lindset Snorre
Published: January 2007

A way to estimate the value of an American exchange option when the underlying assets follow jump‐diffusion processes is presented. The estimate is based on combining a European exchange option and a Bermudan exchange option with two exercise dates by using Richardson extrapolation as proposed by R. Geske and H. Johnson (1984). Closed‐form solutions for the values of European and Bermudan exchange options are derived. Several numerical examples are presented, illustrating that the early exercise feature may have a significant economic value. The results presented should have potential for pricing over‐the‐counter options and in particular for pricing real options. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27:257–273, 2007
Isolation of two regions on rat chromosomes 5 and 18 affecting mammary cancer susceptibility
Authors: Stieber Daniel , Piessevaux Géraldine , Rivière Michèle , Laes Jean‐François , Quan Xiaojiang , Szpirer Josiane , Szpirer Claude
Published: January 2007

We previously mapped several quantitative trait loci (QTLs) controlling DMBA‐induced mammary tumor development in female rats derived from a SPRD‐Cu3 (susceptible strain) × WKY (resistant strain) cross. Two of these QTLs were assigned to chromosomes 5 and 18. In the present study, we generated and characterized congenic strains in which a segment of WKY chromosomes 5 or 18 was introduced in the SPRD‐Cu3 genetic background, thereby physically demonstrating that each of these two chromosomes controls mammary tumor multiplicity. The chromosome 5 QTL (Mcstm1) accounts for 7 tumors per animal (versus a total of 11 tumors per SPRD‐Cu3 rat). The chromosome 18 QTL (Mcstm2) accounts for 3 tumors per animal and is the first chemically‐induced mammary cancer susceptibility locus assigned to this chromosome. In addition, the Mcstm1 region was shown to also controls tumor latency. These loci thus play a major role in chemically‐induced mammary tumor development. QTLs controlling chemically‐induced or estrogen‐induced mammary tumor development have independently been identified on chromosomes 5 and 18, using susceptible strains others than SPRD‐Cu3. Therefore the haplotype structure of the relevant chromosome regions was analyzed in the different strains. Some chromosome regions were found to be highly mosaic (haplotype blocks < 1 Mb), while one region showed an apparently conserved haplotype block of 7.5 Mb. This analysis points to limited regions that could harbor the causative genes and also indicates that at least Mcstm2 is a novel QTL. © 2007 Wiley‐Liss, Inc.
Evidence for heritable predisposition to epigenetic silencing of MLH1
Authors: Chen Huiping , Taylor Nicholas P. , Sotamaa Kaisa M. , Mutch David G. , Powell Matthew A. , Schmidt Amy P. , Feng Sheng , Hampel Heather L. , Chapelle Albert de la , Goodfellow Paul J.
Published: January 2007

Epigenetic silencing of MLH1 is the most common cause of defective DNA mismatch repair in endometrial and colorectal cancers. We hypothesized that variation in the MLH1 gene might contribute to the risk for MLH1 methylation and epigenetic silencing. We undertook a case‐control study to test for the association between MLH1 variants and abnormal MLH1 methylation. Eight MLH1 SNPs were typed in the normal DNA from women with endometrial carcinoma. For these studies, the cases were women whose cancers exhibited MLH1 methylation (N = 98) and the controls were women whose cancers had no MLH1 methylation (N = 219). One MLH1 SNP, rs1800734, located in the MLH1 CpG island at −93 from the translation start site, was significantly associated with MLH1 methylation as were age at diagnosis and patient body mass index. In validation experiments, a similar‐sized cohort of colorectal carcinoma patients (N = 387) showed a similar degree of association with the −93 SNP; a smaller cohort of endometrial carcinomas (N = 181) showed no association. Combining all 3 cohorts showed an odds ratio of 1.61 (95% CI: 1.20–2.16) for the AA or AG vs. GG genotype at the −93 SNP. Identification of risk alleles for MLH1 methylation could shed light on mechanisms of epigenetic silencing and may ultimately lead to new approaches to the prevention or treatment of malignancies associated with MLH1 inactivation. © 2007 Wiley‐Liss, Inc.
Control of crystallinity of hydrated products in a calcium phosphate bone cement
Authors: Wang Xiupeng , Ye Jiandong , Wang Yingjun , Wu Xianpei , Bai Bo
Published: January 2007

In this study, a calcium phosphate cement (CPC), consisting of partially crystallized calcium phosphate (PCCP), was synthesized. X‐ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR) and scanning electronic microscope (SEM) were used to characterize the cement. The results showed that by changing the ratio of amorphous calcium phosphate (ACP) to PCCP in the cement, hydrated products of controllable crystallinity were obtained. With increase in the relative amount of PCCP, the hydrated products changed gradually from very poor crystallinity with little needle‐like hydroxyapatite (Hap) crystallites to relatively high crystallinity with more needle‐like Hap crystallites; the compressive strength of the cement increased, and the degradation of the cement decreased. The cement was implanted into the tibia tubercle of healthy mature Zelanian white rabbits and the histological specimens were obtained after 4 and 16 weeks of implantation. The result revealed that this bone cement was biocompatible and showed very early osteoconductive properties. Thus, the CPC has potential for use in orthopedic surgery for filling non‐ load‐bearing bone defects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Crystallization and preliminary X‐ray analysis of a domain in the Runx2 transcription factor that interacts with the 1α,25 dihydroxy vitamin D3 receptor
Authors: Bruna Carola , Arriagada Gloria , Lian Jane B. , Stein Gary S. , Bunster Marta , Martinez‐Oyanedel Jose , Montecino Martin
Published: January 2007

The Runx2 transcription factor is a key regulator of osteoblast differentiation. In response to 1α,25 dihydroxy vitamin D3, Runx2 may interact with the 1α,25 dihydroxy vitamin D3 receptor (VDR) in the promoter of target genes, producing a synergic activation of their transcription. Previous studies have suggested that the motifs responsible for the VDR–Runx2 interaction are contained within the 230–361 domain of Runx2. In this work, we confirmed by GST‐pull down that Runx2I(209–361) is sufficient to interact with the VDR. To obtain structural information, GST–Runx2I(209–361) protein was overexpressed in Escherichia coli, purified and crystallized using the hanging‐drop vapor‐diffusion method and polyethyleneglycol as a precipitant. The crystals were found to diffract to a maximum resolution of 2.7 Å and a complete data set to a 3.3 Å resolution was collected and analyzed. The crystals belong to the tetragonal system, with a space group P4 and unit‐cell parameters of a = b = 90.8, and c = 57.2 Å. The presence of a monomer of the recombinant GST–Runx2I(209–361) in the asymmetric unit gives a VM of 2.7 Å3 Da−1 and a solvent content of 54.8%. J. Cell. Biochem. 101: 785–789, 2007. © 2007 Wiley‐Liss, Inc.
Transcriptional regulation of human Oct4 by steroidogenic factor‐1
Authors: Yang Heung‐Mo , Do Hyun‐Jin , Kim Dong‐Ku , Park Jin‐Ki , Chang Won‐Kyong , Chung Hyung‐Min , Choi Sang‐Yun , Kim Jae‐Hwan
Published: January 2007

Oct4 encodes a transcription factor that is involved in the maintenance of self‐renewal in stem cells. Recently, the molecular mechanisms that regulate Oct4 expression have come under investigation. In this study, we demonstrate that the orphan nuclear receptor steroidogenic factor‐1 (SF‐1) behaves as a transcriptional activator of human Oct4 (hOct4) through direct interaction with a SF‐1 binding element in the hOct4 proximal promoter. We found that Oct4 and SF‐1 were co‐expressed in undifferentiated human embryonal carcinoma NCCIT cells and downregulated during retinoic acid‐mediated differentiation. We examined the functional role played by SF‐1 in regulation of hOct4 transcription using a luciferase reporter assay and Western blot analysis. Overexpression of SF‐1 increased up to about threefold hOct4 promoter activity and endogenous hOct4 protein expression. Sequence analysis of the hOct4 promoter revealed that the transcriptional activity was closely linked to Conserved Regions 1 (CR1) and 2 (CR2), which contain three putative SF‐1‐binding sites (1st, 2nd, and 3rd SF‐1). Binding assays and mutagenesis of binding sites indicated that the 1st and 2nd SF‐1 elements (in CR1 and CR2, respectively) might be important cis‐regulatory elements in hOct4 promoter activity. However, differences in response to SF‐1 overexpression between wild‐type and mutant hOct4 promoters revealed that the 1st SF‐1 element is the key binding site for SF‐1‐mediated transcriptional activation. Thus, our data indicate that SF‐1 plays a crucial role in the regulation of hOct4 transcription through direct binding to the 1st SF‐1 in CR1 of the hOct4 proximal promoter. J. Cell. Biochem. 101:1198–1209, 2007. © 2007 Wiley‐Liss, Inc.
Calculations of frequency‐dependent molecular magnetizabilities with quasi‐relativistic time‐dependent generalized unrestricted Hartree–Fock method
Authors: Yoshizawa Terutaka , Hada Masahiko
Published: January 2007

The time‐dependent generalized unrestricted Hartree–Fock (TDGUHF) method combined with a two‐component quasi‐relativistic Hamiltonian generated from the Douglas–Kroll–Hess (DKH) transformation was developed to calculate frequency‐dependent molecular magnetizabilities, which are the linear response quantity of a molecule to an external magnetic field. By calculating the magnetizabilities of H2X (X = O, S, Se, and Te), the noble gases (He, Ne, Ar, Kr, and Xe) and small open shell molecules (CH2, CH3, and O2), we found that scalar relativistic terms affect mainly the diamagnetic magnetizability and spin‐orbit (SO) interaction affects the paramagnetic magnetizability. © 2007 Wiley Periodicals, Inc. J Comput Chem 28: 740–747, 2007
Protein kinase D2 potentiates MEK/ERK/RSK signaling, c‐Fos accumulation and DNA synthesis induced by bombesin in Swiss 3T3 cells
Authors: Sinnett‐Smith James , Zhukova Elena , Rey Osvaldo , Rozengurt Enrique
Published: January 2007

Protein kinase D (PKD) plays an important role in mediating cellular DNA synthesis in response to G protein‐coupled receptor (GPCR) agonists but the function of other isoforms of the PKD family has been much less explored. Here, we examined whether PKD2 overexpression in Swiss 3T3 cells facilitates DNA synthesis and the activation of the extracellular regulated protein kinase (ERK) pathway in response to the mitogenic GPCR agonist bombesin. We show that PKD2 overexpression markedly potentiated the ability of this agonist to induce DNA synthesis. Addition of bombesin to Swiss 3T3 cells overexpressing PKD2 also induced a striking increase in the duration of MEK/ERK/RSK activation as compared with cultures of control cells. In contrast, neither DNA synthesis nor the duration of ERK activation in response to epidermal growth factor, which acts via protein kinase C/PKD2‐independent pathways, was increased. Furthermore, bombesin promoted a striking accumulation of c‐Fos protein in cells overexpressing PKD2. Our study demonstrates that PKD2, like PKD, facilitates mitogenesis and supports the hypothesis that an increase in the duration of the ERK signaling leading to accumulation of immediate gene products is one of the mechanisms by which isoforms of the PKD family enhance re‐initiation of DNA synthesis by Gq‐coupled receptor activation. J. Cell. Physiol. 211: 781–790, 2007. © 2007 Wiley‐Liss, Inc.
Expression of Gadd45a and p53 proteins in human pancreatic cancer: Potential effects on clinical outcomes
Authors: Dong Ming , Dong Qi , Zhang Hao , Zhou Jianping , Tian Yulin , Dong Yuting
Published: January 2007

Background and Objectives

p53 gene has a dual role as a trigger of apoptosis and as an initiator of DNA repair. Gadd45a gene assumes the function to maintain the stability of genome. The present study was designed to assess the significance of Gadd45a and p53 protein expression on pancreatic cancer.

Methods

The expression of p53 and Gadd45a was immunohistochemically studied in 59 patients with pancreatic cancer.

Results

The positive expression rate of p53 and Gadd45a was 67.8% and 42.4%, respectively. p53 expression in the patients <65 years was significantly higher than that in the patients ≥65 years (P = 0.030). Gadd 45a expression showed no correlation to the patients' age. There was no relation for p53 expression to differentiation and TNM stages. Gadd 45a expression showed significant difference in histological differentiation (P = 0.007). The median survival time of p53(+) and Gadd45a(+) group was shorter than that of p53(−) and Gadd45a(−) group (P > 0.05), respectively. Meanwhile, the median survival time of p53 (+)Gadd45a(+) group was also shorter than that of p53(−)Gadd45a(−) group (P > 0.05).

Conclusions

p53 and Gadd45a proteins are both highly expressed in pancreatic cancer. The overexpression of p53 and Gadd45a may have connection with the malignant biologic behavior of pancreatic cancer. J. Surg. Oncol.. © 2007 Wiley‐Liss, Inc.
Anti‐friction, anti‐wear and load‐carrying characteristics of environment friendly additive formulation
Authors: Anand O. N. , Kumar Vijay , Singh A. K. , Bisht R. P. S.
Published: January 2007

The extreme pressure (EP), anti‐wear and friction‐reducing characteristics of some of the commercial additive formulation and individual components on which these formulations are based have been studied and compared to characteristics of the components synthesised from naturally available non‐traditional vegetable oils and cashew nut shell liquid that have been refined and partially hydrogenated to improve stability. It has been shown that individual components from sulphurised and phosphosulphurised vegetable oils, esters and hydrogenated cardanol (derived from cashews) have better anti‐wear and friction‐reducing characteristics than the sulphurised olefins and alkylaryl phosphorothioates normally used as EP and anti‐wear additives, while the load‐carrying characteristics of a number of the combination of these derivatives are comparable. It has been shown that all these formulations are rapidly biodegradable and non‐toxic in nature as compared to traditional EP, anti‐wear and friction‐reducing additives, which fill in the category of slightly toxic to harmful.

It is possible to formulate energy‐efficient EP gear oils that are fully biodegradable and non‐toxic by a combination of vegetable oil‐based additives of sulphurised vegetable oils, phosphosulphurised methyl recinoleate and phosphosulphurised hydrogenated cardanol amine borate, which meet all the performance characteristics of US steel 224 eg 52100, M‐50 AISI 1010 requirements. Copyright © 2007 John Wiley & Sons, Ltd.
Copolymers of 3,4‐Ethylenedioxythiophene and 3‐Methylthiophene: Properties, Applications and Morphologies
Authors: Ocampo Cintia , Armelin Elaine , Estrany Francesc , del Valle Luis J. , Oliver Ramón , Sepulcre Francesc , Alemán Carlos
Published: January 2007

Copolymers of 3,4‐ethylenedioxythiophene and 3‐methylthiophene have been prepared by recurrent potential pulses using monomer mixtures with various concentration ratios, their properties being compared with those of the corresponding homopolymers. In addition, different technological applications have been tested for the generated copolymers. Results indicate that the properties of the copolymers are closer to those of poly(3,4‐ethylenedioxythiophene) than to those poly(3‐methylthiophene). Furthermore, the ability of the copolymers to store charge and to interact with plasmid DNA suggest that they are very promising materials.

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Preparation of the Ultra‐Low Dielectric Constant Polyimide Fiber Membranes Enabled by Electrospinning
Authors: Liu Jieyu , Min Yong , Chen Jingyu , Zhou Hongwei , Wang Ce
Published: January 2007

In this article, electrospinning technique has been demonstrated for the synthesis of ultra‐low dielectric constant polyimide fiber membranes. Poly(amic acid) fiber membranes have been prepared as precursor. After the treatment of thermal imidization, ultra‐low dielectric constant polyimide fibers membranes can be obtained. The morphologies and structures of precursors and products are characterized by scanning electron microscopy (SEM), Fourier transmission infrared (FTIR) spectra, and a radio frequency (RF) impedance/capacitance material analyzer. The DK of the as‐prepared polyimide membrane ranges from 1.53 to 1.56, which could be applied in the electronic packaging industry.

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Chemical and microphysical characterization of ambient aerosols with the aerodyne aerosol mass spectrometer
Authors: Canagaratna M.R. , Jayne J.T. , Jimenez J.L. , Allan J.D. , Alfarra M.R. , Zhang Q. , Onasch T.B. , Drewnick F. , Coe H. , Middlebrook A. , Delia A. , Williams L.R. , Trimborn A.M. , Northway M.J. , DeCarlo P.F. , Kolb C.E. , Davidovits P. , Worsnop D.R.
Published: January 2007

The application of mass spectrometric techniques to the real‐time measurement and characterization of aerosols represents a significant advance in the field of atmospheric science. This review focuses on the aerosol mass spectrometer (AMS), an instrument designed and developed at Aerodyne Research, Inc. (ARI) that is the most widely used thermal vaporization AMS. The AMS uses aerodynamic lens inlet technology together with thermal vaporization and electron‐impact mass spectrometry to measure the real‐time non‐refractory (NR) chemical speciation and mass loading as a function of particle size of fine aerosol particles with aerodynamic diameters between ∼50 and 1,000 nm. The original AMS utilizes a quadrupole mass spectrometer (Q) with electron impact (EI) ionization and produces ensemble average data of particle properties. Later versions employ time‐of‐flight (ToF) mass spectrometers and can produce full mass spectral data for single particles. This manuscript presents a detailed discussion of the strengths and limitations of the AMS measurement approach and reviews how the measurements are used to characterize particle properties. Results from selected laboratory experiments and field measurement campaigns are also presented to highlight the different applications of this instrument. Recent instrumental developments, such as the incorporation of softer ionization techniques (vacuum ultraviolet (VUV) photo‐ionization, Li+ ion, and electron attachment) and high‐resolution ToF mass spectrometers, that yield more detailed information about the organic aerosol component are also described. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:185–222, 2007
Tensile Testing of Single Regenerated Cellulose Fibres
Authors: Adusumalli Ramesh‐Babu , Müller Ulrich , Weber Hedda , Roeder Thomas , Sixta Herbert , Gindl Wolfgang
Published: January 2007

Summary: A tensile testing set‐up was developed for the determination of the elastic modulus, tensile strength, and failure strain of single regenerated cellulose fibres. Since the accuracy of strain measurement is crucial for the measured elastic modulus and failure strain, strain measurements were performed mechanically and with a non‐contacting optical method in parallel. The optical validation of mechanical strain measurement showed an agreement of measured strain >99%, confirming the accuracy and usefulness of the set‐up and sample geometry developed for the test series.
Cellulose‐Nanocomposites: Towards High Performance Composite Materials
Authors: Kohler Robert , Nebel Kai
Published: January 2007

Summary: Strong cellulose fibres, e.g. flax and hemp, are increasingly used for composites. Despite substantial advantages, the tensile strength of these fibres is limited due to their complex structure and the unavoidable imperfections of the cell wall, inherent from growth or induced by processing. Essential improvements are possible by using highly crystalline cellulose fibrils (“whiskers”) which can be isolated from the cell wall, thus eliminating the influence of adhesion and defects. Instead of complete fibrillation, which demands special time consuming processing, a partly fibrillation has been achieved by adapted textile finishing procedures which have the potential for mass production. By combining chemical and mechanical/hydro‐mechanical treatments it is possible to produce finest fibrils with diameters from below 1 µm down to the nanometer range. The problem of fibril agglomeration during drying has been avoided by forming homogenous fibrous sheets in a wet‐laid non‐woven process. These sheets can be impregnated with thermosetting resins. Alternatively thermoplastic polymers can be directly integrated to form hybrid materials ready for moulding. The resulting composites show greatly enhanced mechanical properties.
Functional and Comfort Properties of Textiles from TENCEL® Fibres Resulting from the Fibres' Water‐Absorbing Nanostructure: A Review
Authors: Schuster K. Christian , Suchomel Friedrich , Männer Johann , Abu‐Rous Mohammad , Firgo Heinrich
Published: January 2007

Summary: The comfort in wear of textiles has been studied extensively on the level of textile construction. The influence of the fibre material is present in the experience of textile consumers, but objective assessment is rather difficult. Some recent works are reviewed here. TENCEL® is a man‐made cellulosic fibre of the generic fibre type lyocell. The background of the special comfort in wear of textiles made from TENCEL® fibres is explained as a consequence of the fibres' water‐absorbing nanostructure. The basis for these properties are found in the high absorption of water and water vapour, which leads to high heat capacity and heat balancing effect for thermoregulation, comparable with the action of phase change materials. The thermal wear properties resulting are the cool and dry touch, the active cooling effect in sports wear, and the warming properties when used as an insulation layer. These effects are to a certain extent adaptive to the environment, providing comfort in a wide range of climatic conditions. Moreover, neutral electric properties, retarded bacterial growth and good skin sensory perception add to the overall skin friendly properties, which were also shown in wear studies with patients suffering from skin diseases.
Synthesis and Properties of Novel Hydrogels from Cross‐linked Starch Phosphates
Authors: Passauer Lars , Liebner Falk , Fischer Klaus
Published: January 2007

Summary: Starch based stable hydrogels providing high swelling and water storing capacity are not only of certain interest for the cosmetics and hygiene industry but also have the potential to become an effective tool in combating desertification and supporting cultivation in many regions of the world. It has been found that strong water adsorbing covalent networks with free swelling capacity (FSC) of up to 190 g water/g hydrogel can be obtained by cross‐linking low‐substituted mono‐starch phosphates (MSP) in a semi‐dry process with di‐ and tricarboxylic acids such as succinic acid (SA), adipic acid (AA) or citric acid (CA). The linear behaviour over a wide frequency range of the rheological parameters G′ and G″ which were determined by using a shearing disc viscosimeter clearly reveal that the cross‐linked starch phosphates are stable hydrogels having stronger elastic than viscous properties.
Determination of the Mode of Free Radical Termination from Pulsed Laser Polymerization Experiments
Authors: Nikitin Anatoly N. , Hutchinson Robin A.
Published: January 2007

The molecular‐weight distribution (MWD), obtained by pulsed laser polymerization (PLP) at the high termination rate limit has been considered for investigating termination kinetics. The proposed methodology takes into account both the composite model for termination and the chain‐length dependencies of propagation for short‐chain and long‐chain radicals. Power‐law expressions are used to represent propagation $[k_{\rm p}^L = k_{\rm p}^0 (L)^{ - \alpha } ]$ and termination $[k_{\rm t}^{L,L} = k_{\rm t}^0 (L)^{ - \beta } ]$ of long‐chain radicals (where k and k represent the maximum “virtual” rate coefficients for monomeric radicals, and α and β capture the chain‐length dependencies for propagation and termination), with the combined value of (β − α) evaluated from the MWD, after correcting for the influence of the kinetics of short‐chain radicals. A novel method is also developed for determining the mode of termination, δ, from MWDs produced by PLP at the high termination rate limit. Simulations for methyl methacrylate (MMA) polymerization at 25 °C confirm that the method can be applied robustly in the presence of complicating factors such as chain transfer to monomer and SEC broadening. The analysis of an experimental MWD obtained for MMA polymerization at 25 °C results in estimates of 0.14 ± 0.03 for (β − α) and 0.75 ± 0.04 for δ.

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Impaired motor imagery in patients with essential tremor: A case control study
Authors: Lo Yew‐Long , Louis Elan D. , Fook‐Chong Stephanie , Tan Eng‐King
Published: January 2007

Motor imagery (MI), which refers to the process of mental representation of movements, has not been studied in patients with essential tremor (ET). We investigated the presence of impaired MI in ET patients compared with healthy controls. A group of drug‐naive and nondemented ET patients and age‐matched controls were studied using transcranial magnetic stimulation, while they were specifically instructed to try and imagine themselves performing two motor tasks. The various clinical and electrophysiological variables were evaluated and compared. Repeated measures ANOVA demonstrated a significant difference between ET patients and controls with respect to mean motor‐evoked potential (MEP) amplitudes (F(1,38) = 31.92, P < 0.005) during MI. The process of MI effectively facilitated MEP amplitude in controls but not in ET patients, regardless of side of stimulation or motor tasks. We provide evidence to demonstrate impairment of MI in a group of ET patients compared with healthy controls. The basis for this novel finding is unclear, and further studies are warranted to determine whether it is related to cerebellar or motor cortical dysfunction. © 2007 Movement Disorder Society
An Adaptive Finite Element Approach for Brittle Fracture
Authors: Geißler Gordon , Kaliske Michael
Published: January 2007

The extension of the finite element method to take discrete fracture and failure modes into account is a current field of research. In recent times, first results in terms of cohesive element formulations have been introduced into commercial applications. Such element formulations are able to cover the discrete behaviour of interfaces between different materials or the mechanical processes of thin layers. These approaches are not suitable for simulations with unknown crack paths in homogeneous materials, due to the initial elastic phase of the material formulation and the necessity to define potential crack paths a priori. The presented strategy starts with an unextended model and modifies the structure during the computations in terms of an adaptive procedure. The idea is to generate additional elements, based on the cohesive element formulation, to approximate arbitrary crack paths. For this purpose, a failure criterion is introduced. For nodes where the limiting value is reached, cohesive elements are introduced between the volume element boundaries of accordingly facets and corresponding nodes are duplicated. Necessary modifications for this application on system level as well as the element and the material formulation are introduced. By means of some numerical examples, the functionality of the presented procedure is demonstrated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of configurational forces in the context of a kinked crack
Authors: Horst Thomas , Lauke Bernd , Heinrich Gert
Published: January 2007

The application of the configurational force approach in crack problems is often used in order to establish fracture criteria that are adapted to a specific material behaviour. The tangential component of the calculated vectorial quantity that acts at the crack tip is a generalisation of the conventional J‐integral and can be interpreted as the energy release rate when the crack extends in this direction. However, the interpretation of nontangential components in the same way, and hence the interpretation of this vectorial quantity as the crack driving force, is not consistent with established kink criteria in the special case of linear elastic fracture mechanics.

As a classical example, an in‐plane loaded crack in a homogeneous isotropic linear elastic material is considered under the small strain assumption. Using the expansion of stress intensity factors at the extended crack tip, nontangential components of the configurational force can be interpreted as sensitivities to crack deflection. This perspective has the potential of generalisation which can be applied to more complex situations in order to study the interplay between mechanical fields in the vicinity of the crack tip and the microstructural influence within the process zone. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of critical strains and loads in layered composites
Authors: Menshykov Oleksandr V. , Guz Igor A. , Menshykova Maryna V.
Published: January 2007

The present work is devoted to investigation of the compressive fracture for piecewise homogeneous materials with specific kinds of delaminations (defects with connected edges). The critical buckling strains and loads at which ply instability in laminated composites occurs under uniaxial and biaxial compression were evaluated. Different types of layers (linear elastic, elastic‐plastic, hyper‐elastic incompressible) were investigated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isotropic softening model for high‐cycle fatigue
Authors: Paluszyński B. , Schnack E.
Published: January 2007

As known the high cycle loading of structural elements above the fatigue limit results in catastrophic propagation of macroscopic fatigue crack(s). Therefore it is in demand to find a method, which would allow for early prediction of the fatigue life‐time of particular structural element.

The series of force‐driven tests carried on 30CrNiMo8 steel have shown that, although the stresses by high‐cycle fatigue do not reach the tensile stress, the material strength (measured indirectly from the strain‐stress loop) decreases from the begin of the test, hence the damage nucleates and propagates from the very begin of the loading history.

In this study we propose a thermodynamically consistent, strain driven constitutive model for isotropic damage accumulation by high‐cycle fatigue of a homogeneous isotropic material, which should be capable to account for the above‐mentioned experimental results. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)