bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of off‐axis concentrated loading on failure of curved brittle layer structures
Authors: Qasim Tarek , Ford Christopher , Bush Mark B. , Hu Xiaozhi , Lawn Brian R.
Published: August 2005

A study is made of the effects of superposed tangential force by off‐axis indentation loading on curved bilayers consisting of brittle shells filled with polymer support material. Such loadings are pertinent to all‐ceramic crown structures on tooth dentin in occlusal function. Layer flexure places the ceramic undersurfaces in tension, leading to fracture by initiation and propagation of radial cracks. Following an earlier study, model specimens with curved surfaces are prepared by pressing glass plates 1 mm thick onto steel spherical dies with radius of curvature 20 mm to 8 mm at elevated temperatures, and bonding the resultant hemispherical shells onto an epoxy support base. The specimens are tested by indentation with spheres loaded vertically but off‐center, with the contact center located at 30° to the hemisphere axis. The applied loads to initiate radial cracks are little affected by the resultant tangential component, but the loads to propagate the same cracks to the specimen edges are substantially reduced. Finite element calculations are used to evaluate stress states in the specimens for correlation with the experimental data. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Infinite classes of anti‐mitre and 5‐sparse Steiner triple systems
Authors: Fujiwara Yuichiro
Published: August 2005

In this paper, we present three constructions for anti‐mitre Steiner triple systems and a construction for 5‐sparse ones. The first construction for anti‐mitre STSs settles two of the four unsettled admissible residue classes modulo 18 and the second construction covers such a class modulo 36. The third construction generates many infinite classes of anti‐mitre STSs in the remaining possible orders. As a consequence of these three constructions we can construct anti‐mitre systems for at least 13/14 of the admissible orders. For 5‐sparse STS(υ), we give a construction for υ  ≡ 1, 19 (mod 54) and υ  ≠ 109. © 2005 Wiley Periodicals, Inc. J Combin Designs 14: 237–250, 2006
On isomorphic factorizations of circulant graphs
Authors: Alspach Brian , Dyer Danny , Kreher Donald L.
Published: August 2005

We investigate the conjecture that every circulant graph X admits a k‐isofactorization for every k dividing |E(X)|. We obtain partial results with an emphasis on small values of k. © 2006 Wiley Periodicals, Inc. J Combin Designs 14: 406–414, 2006
Butorphanol dependence increases hippocampal κ‐opioid receptor gene expression
Authors: Tanaka Sachiko , Fan Lir‐Wan , Tien Lu‐Tai , Park Younjoo , Liu‐Chen Lee‐Yuan , Rockhold Robin William , Ho Ing Kang
Published: August 2005

Butorphanol is a synthetic opioid agonist/antagonist analgesic agent, which exerts its effects mainly via κ‐opioid receptors. Characterizations of the gene expression levels of the mRNA for and protein levels of the κ‐opioid receptor in different brain regions of rats are essential for investigating possible mechanisms in the development of physical dependence on and withdrawal from butorphanol. Animals were rendered dependent by intracerebroventricular (i.c.v.) infusion of butorphanol (26 nmol/μl/hr) via osmotic minipumps for 3 days. Rats were sacrificed immediately (dependent group) or 7 hr after discontinuation of i.c.v. butorphanol infusion (withdrawal group). Expression levels of the mRNA for the κ‐opioid receptor, as detected by reverse transcription‐polymerase chain reaction followed by Southern blot analysis, were significantly increased in the cerebral cortex, striatum, and midbrain, including thalamus, hippocampus, and pons, in animals dependent on butorphanol. In both dependent and withdrawal groups, Western blot analysis of κ‐opioid receptor protein levels showed significant increases in the amygdaloid nucleus, paraventricular thalamus, and thalamus. However, in the withdrawal group, there were significant decreases in the hippocampus and cortical regions, including the frontal, parietal, and temporal cortex. Regional changes in the mRNA for and protein levels of the κ‐opioid receptor focus attention on highly special roles for this receptor in the development of physical dependence on and the expression of withdrawal from butorphanol dependence. © 2005 Wiley‐Liss, Inc.
New Biodegradable Amphiphilic Block Copolymers of ε‐Caprolactone and δ‐Valerolactone Catalyzed by Novel Aluminum Metal Complexes
Authors: Yang Jing , Jia Lin , Hao Qinghui , Li Yang , Li Qiaobo , Fang Qiang , Cao Amin
Published: August 2005

Summary: In our previous study [J. Yang, L. Jia, L. Yin, J. Yu, Z. Shi, Q. Fang, A. Cao, Macromol. Biosci. 2004, 4, 1092.], new biodegradable copolymers of diblock methoxy poly(ethylene glycol)‐block‐poly(ε‐caprolactone) and methoxy poly(ethylene glycol)‐block‐poly(δ‐valerolactone), and triblock poly(ε‐caprolactone)‐block‐poly(ethylene glycol)‐block‐poly(ε‐caprolactone) and poly(δ‐valerolactone)‐block‐poly(ethylene glycol)‐block‐poly(δ‐valero‐lactone) bearing narrow molecular weight distributions and well‐defined block architectures were reported to be prepared with our original aluminum metal complex templates. This work will continue to report new investigations on their water solubility, and reversible thermal responsive micellization and solution to gel transition in distilled water. Among the new synthesized copolymers (P1–P23), seven diblock or triblock samples (P3, P6, P7, P11, P12, P19, and P21) with higher hydrophilic building block populations were revealed to be water soluble under ambient temperature. By means of UV spectrophotometer attached with a thermostat, important parameters as critical micellization mass concentrations (CMCs) and critical micellization temperatures (CMTs) were characterized for these new amphiphile dilute aqueous solution with the aid of an lipophilic organic dye probe of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH). Furthermore, the critical gelation temperatures (CGTs) were simultaneously investigated for these water‐soluble block copolymers via a tube tilting method. It was found that the CMC, CMT, and CGT were strongly affected by the population and nature of the hydrophobic building blocks, and a higher hydrophobicity of the new amphiphilic block copolymer finally led to lower CMC and CMT, and higher CGT. In addition, the salts of KBr and NaCl were found to play as a salt‐out effect on the solution to gel transition for the diblock P6 and triblock P11, exhibiting an interesting tunable gelation temperature close to 35–42 °C. These results will pave new possibility for the synthesized block structural amphiphiles as potential biomaterials to be applied in vivo.

Thermal responsive micellization and gelation of diblock MPEG‐b‐PCL/PVL and triblock PVL/PCL‐b‐PEG‐b‐PCL/PVL.

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Thermal responsive micellization and gelation of diblock MPEG‐b‐PCL/PVL and triblock PVL/PCL‐b‐PEG‐b‐PCL/PVL.
Isolation and Structure Determination of Complexed Poly(3‐hydroxyalkanoate) from Beet (Beta vulgaris L.)
Authors: Suzuki Yoshikatsu , Esumi Yasuaki , Koshino Hiroyuki , Doi Yoshiharu
Published: August 2005

Summary: Complexed poly(3‐hydroxyalkanoate)s (cPHAs), one of two types of natural PHAs, occur in both prokaryotes and eukaryotes as a complex with biomacromolecules and could be involved in various physiological functions. In this study, a cPHA‐component derived from a complex with calcium polyphosphate was isolated from sugar beet (Beta vulgaris L.) and determined to be a homopolymer composed of 3‐hydroxybutyrate. MALDI MS provided the number‐average molecular weight ($\overline M _{\rm n}$ = 9 124 Da) and polydispersity index (PDI = 1.01), showing that beet cPHA has a slightly lower molecular mass than the known Escherichia coli cPHA. In addition, the structural analysis of both end groups showed that (i) 100 mol‐% of the carboxyl end is free, while about 30 mol‐% of the hydroxyl end is free and about 70 mol‐% masked and (ii) the end hydoxyl group is masked by at least six identified short‐chain alkanoic and alkanedioic acids. Based on such end‐group characteristics, the polymerization mechanism of beet cPHA is discussed.

Chemical structures of beet cPHA.

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Chemical structures of beet cPHA.
Cover Picture: Macromol. Rapid Commun. 17/2005
Authors: Katsampas Ilias , Roiter Yuri , Minko Sergiy , Tsitsilianis Constantinos
Published: August 2005

Cover: A poly(2‐vinyl pyridine)‐block‐poly(acrylic acid)‐block‐poly(butyl methacrylate) ABC terpolymer exhibits a rich polymorphism and multifunctionality in aqueous media. At low pH, three‐compartment spherical micelles are formed which are transformed to other micellar structures, i.e. compact spheres, flower like core‐shell and toroids (AFM images), upon switching pH. The flower like micelles are associated to a three‐dimensional physical network trough loop to bridge transitions above Cp = 0.6 wt.‐% (scheme). Further details can be found in the Communication by I. Katsampas, Y. Roiter, S. Minko, and C. Tsitsilianis* on page 1371.
Customer‐managed end‐to‐end lightpath provisioning
Authors: Wu Jing , Savoie Michel , Campbell Scott , Zhang Hanxi , Bochmann Gregor v. , Arnaud Bill St.
Published: August 2005

Customer‐owned and managed optical networks bring new cost‐saving benefits. Two types of such networks are becoming widely used: metro dark fiber networks and long‐haul leased wavelength networks. Customers may invoke a special QoS mechanism where end‐to‐end (E2E) lightpaths are dynamically established across multiple independently managed customer domains. The cost of bandwidth is substantially reduced since it largely becomes a capital cost rather than an ongoing service charge. Customers can optimize the overall resource consumption by utilizing resources from different suppliers. Remote peering and transit reduce the Internet connectivity cost. Bandwidth and quality of service are guaranteed because customers directly peer with each other using transport networks. An architecture for a customer‐managed E2E lightpath provisioning system is presented. Integration with Grid applications is discussed and a prototype demonstration is described. Copyright © 2005 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Proteomics of human umbilical vein endothelial cells applied to etoposide‐induced apoptosis
Authors: Bruneel Arnaud , Labas Valérie , Mailloux Agnès , Sharma Sanjiv , Royer Nicolas , Vinh Joëlle , Pernet Pascal , Vaubourdolle Michel , Baudin Bruno
Published: August 2005

We have undertaken to continue the proteomic study of human umbilical vein endothelial cells (HUVECs) using the combination of 2‐DE, automated trypsin digestion, and PMF analysis after MALDI‐TOF MS and peptide sequencing using nano LC‐ESI‐MS/MS. The overall functional characterization of the 162 identified proteins from primary cultures of HUVECs confirms the metabolic capabilities of endothelium and illustrates various cellular functions more related to cell motility and angiogenesis, protein folding, anti‐oxidant defenses, signal transduction, proteasome pathway and resistance to apoptosis. In comparison with controls cells, the differential proteomic analysis of HUVECs treated by the pro‐apoptotic topoisomerase inhibitor etoposide further revealed the variation of eight proteins, namely, GRP78, GRP94, valosin‐containing protein, proteinase inhibitor 9, cofilin, 37‐kDa laminin receptor protein, bovine apolipoprotein, and tropomyosin. These data suggest that etoposide‐induced apoptosis of human vascular endothelial cells results from the intricate involvement of multiple apoptosis processes including at least the mitochondrial and the ER stress pathways. The presented 2‐D pattern and protein database, as well as the data related to apoptosis of HUVECs, are available at http://www.huvec.com.
Fluorescence and photoisomerization studies of p‐nitrophenyl‐substituted ethenylindoles
Authors: Singh Anil K. , Hota Prasanta K.
Published: August 2005

The synthesis, electronic absorption, fluorescence (λf, λex, Φf, τf) and photoisomerization (Φt→c, photostationary state composition) properties of 3‐(4‐nitrophenylethenyl‐E)‐NH‐indole (1), 3‐(4‐nitrophenylethenyl‐E)‐N‐ethylindole (2) and 3‐(4‐nitrophenyl ethenyl‐E)‐N‐benzenesulfonylindole (3) in organic solvents of varying polarity are reported. The absorption maximum of these compounds undergoes a moderate red shift with increasing solvent polarity. However, the fluorescence maximum becomes highly red shifted with increasing solvent polarity. Whereas 1 and 2 show broad fluorescence bands, 3 exhibits dual fluorescence. Further, 1 and 2 fluoresce much more efficiently than 3. Correlation of the Stokes shift with solvent polarity parameters such as Δf and ET(30) and excited‐state dipole moment indicate a highly polar excited state for 1–3. Time‐resolved fluorescence studies show that the fluorescence decays are single‐ and multi‐exponential type, depending on the solvent polarity. Further, 1 and 2 do not show photoisomerization on irradiation. However, 3 is photoactive and shows efficient photoisomerization in non‐polar heptane. The sensitivity (ρ) of the photoreaction is determined in various solvent in terms of the Hammett plot, which showed that the excited states involved are electron deficient in nature and consequently stabilized more by an electron sufficient polar solvent and electron donating substituent. These results led us to suggest the existence of three types of excited states, namely the locally excited state, the intramolecular charge‐transfer excited state and the conformationally relaxed intramolecular charge‐transfer excited state in the photoprocesses of these compounds. Copyright © 2005 John Wiley & Sons, Ltd.
In situ FTIR spectroscopic study of the recently detected low‐temperature‐induced structural changes in isotactic polypropylene
Authors: Khafagy Rasha M. , Badr Y. A.
Published: August 2005

The in situ Fourier transform infrared spectroscopic study of isotactic polypropylene showed that structural changes are induced at liquid nitrogen temperature, and start to show up in the FTIR spectra with heating from −196 to +200 °C. This structural change leads to the detection of an abnormal behavior in the MIR absorption spectra of the investigated sample. Lowering the temperature brought the chains closer together and so increased the interchain interaction. At −196 °C splitting of some regularity bands assigned to helical chains within the crystalline region was observed, showing that the regularity of the chains increases because of cooling. Heating the samples from liquid nitrogen temperature caused an opposite conformational disordering, which resulted in the appearance of several new broad bands in the ranges: 600–700, 1614–1640, and 3050–3550 cm−1. These structural changes might be due to both twisting and folding of the chains, which gave rise to bands assigned to the various bending modes of CH2 molecules, in addition to the rotational isomers (conformers) resulting from rotation of the vinyl and alkyne end groups. Moreover, our experimental study of the behavior of several regularity bands suggests that at temperatures in the vicinity of +120 °C another high temperature structural change resulting from the disordering of helical sequences in the noncrystalline region takes place. Differential scanning calorimetry thermograms of the thermally treated and an untreated sample were found to confirm the obtained results. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2829–2842, 2005
Impedance spectra analysis of thermoresponsive poly(acryloyl‐L‐proline methyl ester) gel membrane in LiCl solution
Authors: Chen Jinhua , Asano Masaharu , Tsubokawa Norio , Maekawa Yasunari , Yamaki Tetsuya , Yoshida Masaru
Published: August 2005

Impedance spectra analysis of a thermoresponsive poly(acryloyl‐L‐proline methyl ester) (poly(A‐ProOMe)) hydrogel membranes in an aqueous solution of LiCl was carried out using a simple equivalent model. The hydrogel membrane was synthesized by γ‐radiation‐induced polymerization and crosslinking of A‐ProOMe monomer aqueous solution in a glass‐cast. By means of the impedance spectra analysis, a novel method for the calculation of the ionic conductivity of the hydrogel membranes in LiCl solution was proposed. The calculated ionic conductivity was in agreement with the determined value. In addition, effects of temperature and LiCl concentration on the impedance spectra and ionic conductivity of the gel membrane were analyzed. Results indicated that the impedance spectra analysis is a very useful tool for evaluating the electric properties of gel membranes in an electrolyte solution. The poly (A‐ProOMe) gel membrane in 1.0 M LiCl solution showed a high ionic conductivity of about 0.2 S/cm at 14 °C. The temperature‐dependence of the ionic conductivity was a complex nonlinear form due to the volume phase transition of the thermoresponsive poly(A‐ProOMe) gel membrane, and the volume phase transition temperature appeared to be decreased with the increase in the LiCl concentration. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2843–2851, 2005
NMR assignments of tryptophan residue in apo and holo LBD‐rVDR
Authors: Sicinska Wanda , Westler William M. , DeLuca Hector F.
Published: August 2005

Binding sites in the full‐length, ligand‐binding domain of rat vitamin D receptor (LBD‐rVDR) for an active hormone derived from vitamin D (1α,25‐dihydroxyvitamin D3) and three of its C‐2 substituted analogs were compared by nuclear magnetic resonance (NMR) spectroscopy. Specific residue labeled with [UL]‐15N2Trp allowed assignment of the side‐chain Hϵ1and Nε1resonances of the single tryptophan residue at position 282 in LBD‐rVDR. Comparison of1H[15N] Heteronuclear Single Quantum Correlation (HSQC) spectra of apo and holo LBD‐rVDR revealed that the position of the Trp282 Hε1and Nε1signals are sensitive to the presence of the ligand in the receptor cavity. Binding of the ligands to LBD‐rVDR results in a shift of both Trp Hε1and Nε1resonances to lower frequencies. The results indicate that the interaction between the ligands and Trp282 is not responsible for differences in calcemic activity observed in vitamin D analogs. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Inerting of centrifuges for safe operation
Authors: Grossel Stanley S.
Published: August 2005

Many centrifuging operations are hazardous because the feed slurries and wash liquors contains flammable liquids. In addition, ignition sources are frequently present. To avoid fires and explosions in centrifuges, purging is commonly applied before operation begins, and blanketing is done during operation, to lower the oxygen concentration below the limiting oxygen concentration of the flammable liquid. This communication discusses and describes the three commonly used inerting systems: monitoring by flow, monitoring by pressure, and monitoring by oxygen analysis. Details are given for each method, including schematic drawings and inerting procedures. General requirements for an effective centrifuge inerting system are discussed. Also, design considerations are presented for oxygen analyzer systems to avoid problems in their use. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
TEM characterization of La/B4C multilayer systems by the geometric phase method
Authors: Häussler D. , Spiecker E. , Yang S. , Jäger W. , Störmer M. , Bormann R. , Zwicker G.
Published: August 2005

New La/B4C multilayer systems with layer thicknesses in the nanometer range have been deposited onto structured silicon (001) surfaces by magnetron sputtering and have been characterized by transmission electron microscopy (TEM). By applying a geometric phase method which has been originally developed for measuring displacement fields from high‐resolution TEM images, we demonstrate that the structural perfection of multilayers, especially their local layer periods and local layer orientations, can be analyzed with high sensitivity from bright‐field TEM images of cross‐section specimens. The determination of these structure parameters is relevant for the assessment of the reflectivity properties of such multilayer systems in advanced X‐ray optical components. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective and practical risk management options for computerised system validation
Authors: McDowall R.D.
Published: August 2005

Risk management and risk assessment for computerised systems validation is a key regulatory issue following the Food and Drug Administration's (FDA) reassessment of the 21 Code of Federal Regulation (CFR) Part 11 regulations (Electronic Records and Electronic Signatures final rule). This paper reviews the GXP (i.e. Good Laboratory Practice (GLP), Good Clinical Practice (GCP) and Good Manufacturing Practice (GMP)) regulatory requirements and associated guidance documents and then focuses on the International Standards Organisation (ISO) 14971 risk management process and vocabulary for an overall risk management framework.

Several risk analysis methodologies are presented and assessed for their applicability for computerised system validation (CSV). The conclusion is that one methodology does not fit all situations and the prudent professional should select the best methodology applicable for the problem at hand. Finally, an overall risk management process flow for CSV is presented and discussed based on two questions: ‘Do I need to validate the system?’ and if so, ‘How much work do I need to do?’ A single integrated document is presented as an alternative to a full V‐model for the validation of lower risk computer systems. Copyright © 2005 John Wiley & Sons, Ltd.
What's New?
Authors: Hattemer‐Apostel Rita , Broughton Harold Steven
Published: August 2005

The What's New? section in the Quality Assurance Journal aims to draw attention to items of importance to QA professionals. There is usually a three‐month interval between final submission of manuscripts and distribution of the journal. For this issue, the entries in the What's New? section arise from the period of 1 March 2005 to 31 May 2005. If you feel that there is any other new information that should be brought to the attention of readers, please let us know by e‐mailing rha@verdandi.ch. Copyright © 2005 John Wiley & Sons, Ltd.
An adaptive quality‐of‐service network selection mechanism for heterogeneous mobile networks
Authors: Song Qingyang , Jamalipour Abbas
Published: August 2005

The success of broadband service has attracted more people to surf internet with the demand of high mobility and high bandwidth. The ongoing wireless local area network (WLAN) standardization and development activities allow WLAN to provide high data rate in unlicensed spectrum. It motivates cellular network operators to adopt WLAN as a complement to cellular 3G systems in hot spot areas. Consequently, it is imperative to develop a network selection technique to assure quality‐of‐service (QoS) for the integrated cellular/WLAN system. In this paper, an optimization scheme for mobile users to select a network in an integrated WLAN and universal mobile telecommunication system (UMTS) system is proposed. In order to provide users a prospect of being always best connected, analytic hierarchy process (AHP) and grey relational analysis (GRA) techniques are integrated to make decision. The former defines selection criteria and the latter evaluates network alternatives. The network selection module is built at the link layer, and collects the time‐varying QoS information through cross‐layer message signaling. Simulations conducted in a heterogeneous system with UMTS and WLAN show that the proposed network selection technique can successfully satisfy QoS requirements for a variety of applications through a fair decision on the optimum network for mobile users at any time. Copyright © 2005 John Wiley & Sons, Ltd.
Candida albicans SOU1 encodes a sorbose reductase required for L‐sorbose utilization
Authors: Greenberg Jay R. , Price Neil P. , Oliver Richard P. , Sherman Fred , Rustchenko Elena
Published: August 2005

Previous work in our laboratory showed that L‐sorbose utilization in Candida albicans is subject to a novel form of regulation which involves a reversible increase or decrease in the copy number of chromosome 5. Furthermore, the structural gene SOU1 is required for L‐sorbose utilization and encodes a member of the short chain dehydrogenase family. However, the precise function of SOU1 was not known and neither was the pathway for L‐sorbose utilization. We have now expressed SOU1 at a high level from a replicative plasmid having a constitutive ADH1 promoter and purified a version of Sou1p tagged with the FLAG epitope at the N‐terminus. Sou1FLAGNp has a sorbose reductase activity which utilizes NADPH as a co‐factor and converts L‐sorbose to D‐sorbitol. It can also less efficiently utilize fructose as a substrate with NADPH as a co‐factor, converting fructose to mannitol. In agreement with prediction, the purified enzyme has a subunit molecular weight of 31 kDa and a pI of about 4.8. It probably consists of four identical subunits and has a pH optimum of 6.2. The L‐sorbose utilization pathway in C. albicans probably converts L‐sorbose to fructose‐6‐phosphate via D‐sorbitol as an intermediate. The first step is catalysed by Sou1p. We also found that C. albicans extracts have a D‐sorbitol‐6‐phosphate dehydrogenase activity, not encoded by SOU1, which utilizes NADP as a co‐factor. This activity has not been described previously in yeasts and may be involved in the conversion of phosphorylated D‐sorbitol to fructose‐6‐phosphate or glucose‐6‐phosphate. Copyright © 2005 John Wiley & Sons, Ltd.
Characterization of thiol‐specific antioxidant 1 (TSA1) of Candida albicans
Authors: Shin Duck Hyang , Jung Saem , Park So Jeong , Kim Yeo Jung , Ahn Jung Min , Kim Wankee , Choi Wonja
Published: August 2005

We previously identified several proteins that are differentially expressed in pathogenic hyphae by comparing protein profiles of yeast and hyphae of Candida albicans. One of these, thiol‐specific antioxidant 1 (TSA1), attracted our attention because it may play some roles in surviving an unfavourable oxidative environment created by host cells. Two alleles of the C. albicans TSA1 (CaTSA1) gene are located in opposite orientation on the same chromosome. Using PCR‐directed disruption cassettes and URA‐Blaster, a series of deletion mutants that lack one to four copies were constructed to examine the functions of CaTSA1. Northern and Western analyses showed that both the transcript and protein products of CaTSA1 decreased proportionally to the disrupted copy number and were completely absent in the null mutant, indicating that all four TSA1 copies are equally functional at the transcriptional level. Intracellular H2O2 increased by an order of magnitude in deletion mutants lacking three to four copies, suggesting that CaTsa1p is not a redundant H2O2 scavenger. CaTsa1p was indispensable for yeast‐to‐hyphal transition when C. albicans was cultured under oxidative stress. The level of its oxidized form increased ∼five‐fold in hyphal cells, whereas that of the reduced form increased two‐fold compared to yeast cells. The ratio of oxidized to reduced form was increased three‐fold in hyphal cells. This overall increase was found to be controlled at the post‐transcriptional level. Interestingly, CaTsa1p is translocated to the nucleus of hyphal cells. These findings may be of biological significance for differentiation and pathogenicity. Copyright © 2005 John Wiley & Sons, Ltd.
Characterization of GPI14/YJR013w mutation that induces the cell wall integrity signalling pathway and results in increased protein production in Saccharomyces cerevisiae
Authors: Davydenko Svetlana G. , Feng DeJiang , Jäntti Jussi , Keränen Sirkka
Published: August 2005

We report here identification and characterization of a mutation in the GPI14 gene, the yeast homologue of the mammalian PIG‐M that functions in the synthesis of the GPI moiety anchoring proteins to the plasma membrane. We show that the first putative transmembrane domain of Gpi14p is not essential for its function. Downregulation of GPI14 expression/reduced protein function due to an amino terminal deletion resulted in increased transcription and production of an endogenous and a heterologous secreted protein expressed from HSP150 and ADH1 promoter, respectively. In these cells, unfolded protein response was induced but was not responsible for the enhanced production of these proteins. A cell wall defect in the gpi14 mutant cells was suggested by cell aggregation phenotype, increased sensitivity to Calcofluor white, an increased release of Gas1p and total protein into the culture medium. In the gpi14 mutant cells, transcription of RLM1, a transcription factor participating in the cell wall integrity signalling pathway, was increased, and deletion of RLM1 resulted in a synthetic lethal phenotype with the gpi14 mutation. These results suggest that partial inactivation of Gpi14p causes defects in the cell wall structure and suggest that compromised GPI anchor synthesis results in enhanced protein production via the cell wall integrity signalling pathway. Copyright © 2005 John Wiley & Sons, Ltd.
Low‐Dimensional Structural Units in Amine‐Templated Uranyl Oxoselenates(VI): Synthesis and Crystal Structures of [C3H12N2][(UO2)(SeO4)2(H2O)2](H2O), [C5H16N2]2[(UO2)(SeO4)2(H2O)](NO3)2, [C4H12N][(UO2)(SeO4)(NO3)], and [C4H14N2][(UO2)(SeO4)2(H2O)]
Authors: Krivovichev Sergey V. , Kahlenberg Volker
Published: August 2005

The crystals of four amine‐templated uranyl oxoselenates(VI), [C3H12N2][(UO2)(SeO4)2(H2O)2](H2O) (1), [C5H16N2]2[(UO2)(SeO4)2(H2O)](NO3)2 (2), [C4H12N][(UO2)(SeO4)(NO3)] (3), and [C4H14N2][(UO2)(SeO4)2(H2O)] (4) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The crystal structures of all four compounds have been solved by direct methods from X‐ray diffraction data. The structure of 1 (triclinic, ${\rm P}{\bar 1}$, a = 7.5611(16), b = 7.7650(17), c = 12.925(3) Å, α = 94.605(18), β = 94.405(17), γ = 96.470(17)°, V = 748.8(3) Å3, R1 = 0.029 for 2769 unique observed reflections) is based upon 0D‐units of the composition [(UO2)2(SeO4)4(H2O)4]4−. These discrete units are composed from two pentagonal [UO7]8− bipyramids linked via [SeO4]2− tetrahedra and are unknown in structural chemistry of uranium so far. The structure of 2 (monoclinic, C2/c, a = 28.916(5), b = 8.0836(10), c = 11.9856(16) Å, β = 110.909(11)°, V = 2617.1(6) Å3, R1 = 0.035 for 2578 unique observed reflections) contains [(UO2)(SeO4)2(H2O)]2− chains of corner‐sharing pentagonal [UO7]8− bipyramids and [SeO4]2− tetrahedra. The chains run parallel to the c axis and are arranged into layers parallel to (100). In the structure of 3 (monoclinic, C2/m, a = 21.244(5), b = 7.1092(11), c = 8.6581(18) Å, β = 97.693(17)°, V = 1295.8(4) Å3, R1 = 0.027 for 1386 unique observed reflections), pentagonal [UO7]8− bipyramids share corners with three [SeO4]2− tetrahedra each and an edge with a [NO3]− anion to form [(UO2)(SeO4)(NO3)]− chains parallel to the b axis. In the structure of 4 (triclinic, ${\rm P}{\bar 1}$, a = 6.853(2), b = 10.537(3), c = 10.574(3) Å, α = 99.62(3), β = 94.45(3), γ = 100.52(3)°, V = 735.6(4) Å3, R1 = 0.045 for 2713 unique observed reflections), one symmetrically independent pentagonal [UO7]8− bipyramid shares corners with four [SeO4]2− tetrahedra to form the [(UO2)(SeO4)2(H2O)]2− chains parallel to the a axis. A comparison to related uranyl compounds is given.
Synthesis and Structure of a New Vanadium(IV)‐Cadmium(II) Compound with the Nitrilotriacetate Ligand: {(NH4)2[(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]·H2O}n
Authors: Zhang Quan‐Zheng , Lu Can‐Zhong , Yang Wen‐Bin
Published: August 2005

A polymeric VIV‐Cd compound, {(NH4)2[(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]·H2O}n (H3nta = nitrilotriacetic acid), has been prepared and characterized by single‐crystal X‐ray diffraction. The compound crystallizes in the monoclinic space group C2/c with a = 17.3760(2) Å, b = 8.0488(1) Å, c = 17.3380(2) Å, β = 107.9690(10)°, V = 2306.55(5) Å3, Z = 4, and R1 = 0.0303 for 1958 observed reflections. The structure exhibits a heterometallic three‐dimensional network formed by polymeric [(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]2− anions.
Amine‐Templated Uranyl Selenates with Layered Structures. I Structural Diversity of Sheets with a U:Se ratio of 1:2
Authors: Krivovichev Sergey V. , Kahlenberg Volker , Tananaev Ivan G. , Myasoedov Boris F.
Published: August 2005

Crystals of four amine‐templated layered uranyl selenates, [C2H10N2][(UO2)(SeO4)2(H2O)](H2O) (1), [CH6N3]2[(UO2)(SeO4)2(H2O)](H2O)1.5 (2), [C4H12N]2[(UO2)(SeO4)2(H2O)] (3), and [CH6N3]3[(UO2)2(SeO4)2(H(SeO4)2)](H2O)2 (4) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The structures of all four compounds have been solved by direct methods. The structures of 1 (monoclinic, C2/c, a = 11.787(2), b = 7.7007(10), c = 16.600(3) Å, β = 102.016(14)°, V = 1473.7(4) Å3, R1 = 0.037 for 1743 unique observed reflections), 2 (monoclinic, C2/c, a = 37.314(4), b = 7.1771(6), c = 13.2054(14) Å, β = 109.267(8)°, V = 3338.4(6) Å3, R1 = 0.088 for 3005 unique observed reflections) and 3 (monoclinic, C2/c, a = 27.212(10), b = 7.372(3), c = 23.113(7) Å, β = 117.75(2)°, V = 4103(3) Å3, R1 = 0.073 for 2111 unique observed reflections) are based on sheets of the composition [(UO2)(SeO4)2(H2O)]2− consisting of pentagonal [UO7]8− pentagonal bipyramids linked via [SeO4]2− tetrahedra. The sheets have the same chemical composition but different topologies. The structure of 4 (orthorhombic, P212121, a = 10.7261(9), b = 13.918(2), c = 18.321(2) Å, V = 2735.1(5) Å3, R1 = 0.050 for 5683 unique observed reflections) contains [(UO2)2(SeO4)2(H(SeO4)2)]3− sheets parallel to (001). In all four structures, the layers are connected via protonated amine and H2O molecules.
Complexation of 1,4‐Bis(phenylthio)butane on Mercury(II) Salts: Formation of Extended 2D Coordination Polymers
Authors: Peindy Harmel N. , Guyon Fabrice , Knorr Michael , Strohmann Carsten
Published: August 2005

Two novel two‐dimensional (2D) coordination polymers of stoichiometry [{PhS(CH2)4SPh}Hg2X4]n (X = Cl, 2a; X = Br, 2b) have been prepared by treatment of HgX2 with PhS(CH2)4SPh 1, acting as bridging dithioether ligand. The extended 2D structures result from bridging coordination of 1 between two mercury atoms and intermolecular Hg–X interactions, thus linking the HgX2 units in two dimensions. As established for 2a,b by single‐crystal X‐ray diffraction, the coordination around the Hg centers in both isomorphous compounds (monoclinic, space group P21/c) is distorted tetrahedral, with quite short Hg‐thioether bonds of 2.4780(19) (2a) and 2.499(3) Å (2b), respectively.
Darstellung und Kristallstruktur von Cadmiumazid Cd(N3)2
Authors: Karau Friedrich , Schnick Wolfgang
Published: August 2005

Preparation and Crystal Structure of Cadmium Azide Cd(N3)2

Solvent free, binary cadmium azide was synthesized by the reaction of cadmium carbonate and a 24 weight% solution of HN3 in water. Cadmium azide is a colorless, crystalline powder which is highly sensitive to percussion and heat. Caution, the manipulation of Cd(N3)2 is very dangerous!

The crystal structure was solved by single‐crystal methods and the phase purity was verified by a Rietveld refinement (Cd(N3)2, Pbca, no. 61; a = 7.820(2), b = 6.440(2), c = 16.073(3) Å; Z = 8, 1174 independent reflections, 64 parameters, R1 = 0.022). Cadmium azide crystallizes in a new structure type. In the crystal there are edge‐sharing Cd2(N3)10 double octahedrons which are further connected to other units by azide bridges. Vibrational spectroscopic investigations (Raman an IR) are discussed with respect to the crystal structure data.
[{ReN(PMe2Ph)3}{ReO3N}]2 – Structural Evidence for the Nitridotrioxorhenate(VII) Anion, [ReO3N]2−
Authors: Braband Henrik , Yegen Eda , Oehlke Elisabeth , Abram Ulrich
Published: August 2005

Air‐stable, orange‐red single crystals of [{ReN(PMe2Ph)3}{ReO3N}]2 are formed when mer‐[ReNCl2(PMe2Ph)3] reacts with strong bases in MeOH. The resulting centrosymmetric tetranuclear complex contains each two {ReN(PMe2Ph)3}2+ and {ReO3N}2− building blocks. They are connected by two oxygen and two nitrogen atoms giving an almost planar {Re4O2N2} ring. The Re–N–Re bridges are only slightly bent (175.2(2)°), while the Re–O–Re angles are 160.9(1)°. The coordination environment of the rhenium atom in the nitridotrioxorhenate(VII) anion is a slightly distorted tetrahedron with O–Re–O and O–Re–N angles between 108.7(1)° and 111.3(1)°.
Selenious Acid as a Ligand: Molecular and Crystal Structure of [Co(H2O)2Cl2(H2SeO3)2]
Authors: Hamida Makram Ben , Wickleder Mathias S.
Published: August 2005

[Co(H2O)2Cl2(H2SeO3)2] (monoclinic, P21/c, Z = 2, a = 519.82(5), b = 1462.6(1), c = 643.09(7) pm, β = 92.51(1)°, Rall = 0.0583) was obtained from CoCl2 and H2SeO3 as purple plate–shaped single crystals. In the compound, the Co2+ ions are octahedrally coordinated by two Cl− ions, two H2O molecules, and two monodentate H2SeO3 molecules, leading to neutral complexes [Co(H2O)2Cl2(H2SeO3)2]. They are connected by hydrogen bonds involving both chlorine and oxygen atoms as acceptor atoms.
Synthese, Charakterisierung und Struktur des donorstabilisierten monomeren [PS3]− – Anions (Monometatrithiophosphates)
Authors: Dimitrov Anton , Hartwich Irmgard , Ziemer Burkhard , Heidemann Detlef , Meisel Manfred
Published: August 2005

Synthesis, Characterization, and Structure of the Donor‐stabilized Monomeric [PS3]− Anion (Monometatrithiophosphate)

The reaction between H2S and some σ4λ5‐derivatives of the monometa‐dithioxaphosphoric acid, [Py→PS2X] (Py = pyridine, X = Cl, NR2), at low temperature in propionitrile as a solvent leads to the formation of the corresponding ammonium salts with the new anion [Py→PS3]− (1). The single crystal structure determinations of three compounds 1a‐1c bearing the new title anion 1 reveal the existence of considerably short distances between the nitrogen of the cation and the sulphur atoms of the anion connected by a cationic proton in all cases. These hydrogen bond contacts fall below the sum of van der Waals radii of nitrogen and sulphur and are crucial for the stabilization of 1 in the crystals which is an electronical support in nature. If acidic hydrogen atoms are not present in the cations of the salts as in the case of tetraphenylarsonium as a counter cation a stabilisation of the new anion 1 does not occur. In this case, even from pyridine solutions, only the salt with the well known dimeric anion [PS3]22− crystallizes.
Synthesis, Characterization and Crystal Structures of new Palladium(II) Complexes and the first Platinum(III) Complex Containing ATT (ATT = 6‐Aza‐2‐thiothymine)
Authors: Ghassemzadeh Mitra , Heravi Majid M. , Neumüller Bernhard
Published: August 2005

Treatment of the ligand 6‐aza‐2‐thiothymine (ATT, HL, 1) with palladium chloride in methanol forms the ionic complex [(HL)4Pd]Cl2·8MeOH (2), while its reaction with palladium iodide in same solvent produces the neutral complex trans‐[(HL)2PdI2]·2MeOH (3) in high yields. The reaction of 1 with Na2[PdCl4] in the presence of sodium acetate in a molar ratio of 2:1:2 and with platinum(II) chloride in presence of sodium acetate led to the dimer tetranuclear complexes [(L4Pd2)NaCl]2·8MeOH (4) and [L4Pt2Cl2]·6MeOH·H2O (5). The latter is the first PtIII complex of the ligand. All complexes were characterized by elemental analyses and IR spectroscopy and the crystal structures of 2, 3, 4 and 5 are determined by single‐crystal X‐ray diffraction. Crystal data for 2 at −80 °C: triclinic space group ${\rm P}{\bar 1}$, a = 1006.6(1), b = 1006.9(1), c = 1158.1(1) pm, α = 85.20(1)°, β = 83.84(1)°, γ = 88.91(1)°, Z = 1, R1 = 0.0278; for 3 at −80 °C: triclinic space group ${\rm P}{\bar 1}$, a = 490.5(1), b = 977.2(2), c = 1116.8(2) pm, α = 90.26(1)°, β = 102.33(1)°, γ = 96.08(1)°, Z = 1, R1 = 0.0394; for 4 at −80 °C: orthorhombic space group Ccca, a = 1791.7(2), b = 1874.1(2), c = 2044.0(1) pm, Z = 4, R1 = 0.0341 and for 5 at −80 °C: monoclinic space group P21/c, a = 1464.3(1), b = 2003.7(1), c = 1368.5(1) pm, β = 95.66(1)°, Z = 4, R1 = 0.0429.
Selten‐Erd‐Metall‐Koordinationspolymere: Synthesen und Kristallstrukturen von drei neuen Glutaraten, [Pr2(Glu)3(H2O)4] · 10,5H2O, [Pr(Glu)(H2O)2]Cl und [Er(Glu)(GluH)(H2O)2]
Authors: Bromant Claudia , Nika Wassiliki , Pantenburg Ingo , Meyer Gerd
Published: August 2005

Rare‐Earth‐Metal Coordination Polymers: Syntheses and Crystal Structures of Three New Glutarates, [Pr2(Glu)3(H2O)4] · 10.5H2O, [Pr(Glu)(H2O)2]Cl, and [Er(Glu)(GluH)(H2O)2]

The new rare‐earth dicarboxylates [Pr2(Glu)3(H2O)4] · 10.5H2O (1), [Pr(Glu)(H2O)2]Cl (2) and [Er(Glu)(GluH)(H2O)2] (3) were obtained from the reactions of glutaric acid with PrCl3·6H2O and Er(OH)3, respectively. The crystal structures were determined by single‐crystal X‐ray diffraction. [Pr2(Glu)3(H2O)4] · 10,5H2O crystallizes in the orthorhombic space group Pnma (no. 62) with a = 871.7(4), b = 3105.0(9), c = 1308.3(9) pm and Z = 4. The crystals of [Pr(Glu)(H2O)2]Cl are monoclinic (I2/a; no. 15) with a = 786.2(1), b = 1527.6(2) c = 801.2(1) pm, β = 99.78(1)° and Z = 4. [Er(Glu)(GluH)(H2O)2] crystallizes in the monoclinic space group P21/a (no. 14) with lattice parameters of a = 882.4(1), b = 1375.3(2), c = 1267.4(2) pm, β = 107.13(1)° and Z = 4. The rare‐earth cations have the coordination numbers 10 (1), 8 + 1 (2) and 9 (3). The individual polyhedra are connected to chains and further to sheets in 1 and 2 and to double chains in 3. Only in the water‐rich compound 1 there are channels that contain crystal water molecules. It, therefore, has a considerably lower density than 2 and 3.
A New Copper(II) Complex with the N,N′‐Tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) Ligand: [Cu(TAMEN)](ClO4)2·H2O·DMF
Authors: Tudose Ramona , Pantenburg Ingo , Mosoarca Elena Maria , Meyer Gerd , Costişor Otilia
Published: August 2005

The synthesis of the Mannich base N,N′‐tetra(antipyryl‐4‐methyl)‐1,2‐ethanediamine (TAMEN) (1), its crystal structure as well as the synthesis and the crystal structure of the copper complex [Cu(TAMEN)](ClO4)2·H2O·DMF (2) are reported. C50H56N10O4·2C2H5OH (TAMEN·2EtOH) crystallizes with triclinic symmetry, space group $P{\bar 1}$, lattice parameters: a = 877.3(1), b = 1078.1(1), c = 1433.3(2) pm, α = 71.93(1), β = 82.16(1), γ = 84.54(1)° and Z = 1. The copper complex [Cu(TAMEN)](ClO4)2·H2O·DMF also crystallizes with triclinic symmetry, space group $P{\bar 1}$, lattice parameters: a = 1279.2(2), b = 1485.6(2), c = 1513.6(2) pm, α = 98.04(1), β = 101.24(1), γ = 94.66(1)° and Z = 2. The copper(II) atom is six‐coordinate with an elongated pseudo‐octahedral geometry due to a strong Jahn‐Teller effect.
Carbonyl‐Komplexe von Chrom, Molybdän und Wolfram mit Isocyanacetat. Reaktionen am koordinierten Isocyanacetat. Stabilisierung von Isocyanessigsäure und Isocyanacetylchlorid am Metall. Isocyanopeptide [1]
Authors: Achatz Dagobert , Lang Markus A. , Völkl Alfons , Fehlhammer Wolf Peter , Beck Wolfgang
Published: August 2005

Carbonyl Complexes of Chromium, Molybdenum and Tungsten with Isocyano Acetate. Reactions of Coordinated Isocyanoacetate. Stabilization of Isocyanoacetic Acid and Isocyanoacetyl Chloride at the Metal Atom. Isocyanopeptides

The reactions of [(OC)5MCNCH2CO2Et] (M = Cr, W) with Na[N(SiMe3)2] or with KOH afford the isocyanoacetate complexes [(OC)5MCNCH2CO2]− (1,2). Similarly, the complex [(OC)3Mo(CNCH2CO2−Li+)3] (4) was obtained from [(OC)3Mo(CNCH2CO2Et)3] (3) and LiOH. Protonation of 1 and 2 affords the sublimable isocyanoacetic acid complexes [(OC)5MCNCH2CO2H] (5, 6; M = Cr, W) in which the functional isocyanide is stabilized at the metal atom. Reactions of [(OC)5WCNCH2CO2−K+] and of [(OC)3Mo(CNCH2CO2−Li+)3] with oxalyl dichloride give the isocyanoacetyl chloride compounds [(OC)5WCNCH2COCl] (9) (sublimable) and [(OC)3Mo(CNCH2COCl)3] (10); the latter (10) was not isolated. Complexes 9 and 10 were reacted in situ with β‐alanine, glycine, phenylalanine and methionine esters as well as the peptide esters GlyGlyOEt, PhePheOMe, Phe‐β‐AlaOMe, and GlyGlyGlyOMe to form the isocyanoacetyl amino acid esters (11 ‐ 14) and the isocyanoacetyl peptide esters (15 ‐ 18) which are stabilized at the molybdenum atom.
A New Type of Anionic Framework in Microporous Potassium Iron(II) Phosphate K[Fe(PO4)]
Authors: Yakubovich Olga V. , Massa Werner , Dimitrova Olga V.
Published: August 2005

A new iron(II) orthophosphate K[Fe(PO4)] has been obtained by hydrothermal synthesis and its crystal structure was determined by single‐crystal X‐ray diffraction: space group P21/n, Z = 8, a = 9.6199(10), b = 8.6756(8), c = 10.8996(13) Å, β = 115.577(8)° at 193 K, R = 0.023. FeII shows coordination numbers (CN) 4 (distorted tetrahedral) and CN 5 (distorted trigonal bipyramidal). The [FeO4] and [FeO5] units form together with the [PO4] tetrahedra a microporous 3D para‐framework with open channels along the a and b directions. The potassium ions positioned in the channels show CN 7 and 8. The structural relations within the morphotropic row of non‐isotypic K[M(PO4)] structures (M = Zn, Ni, Mn, Fe) are discussed on the basis of common basic structural units.
A Tetrameric Neodymium Silanolate: [Nd(OSiMe3)3]4
Authors: Mansfeld Dirk , Mehring Michael
Published: August 2005

The title compound [Nd(OSiMe3)3]4 (1) was prepared by reaction of [Nd{N(SiMe3)2}3] with Me3SiOH in toluene at room temperature. Compound 1 crystallized from a concentrated toluene solution in the monoclinic space group P21/n with the lattice constants a = 15.144(1) Å, b = 25.142(1) Å, c = 20.391(1) Å and β = 103.755(2)°. In the solid state a tetramer is observed which shows Nd‐O bond distances in the range 2.129(2)‐2.675(2) Å.
Reactions of Nitridotechnetium(V) Complexes with Boranes
Authors: Hagenbach Adelheid , Abram Ulrich
Published: August 2005

Nitrido bridges between technetium and boron were formed during reactions of [TcN(PMe2Ph)(Et2dtc)2] (Et2dtc− = diethyldithiocarbamate) and BH3 or BPhCl2 at low temperatures. X‐Ray structure determinations show that the products contain almost linear Tc–N–B bonds with Tc–N distances which are only slightly lengthened with respect to the triple bonds in the precursor molecule. However, a significant lengthening of the Tc–S bond trans to the nitrido ligand is detected by the decrease of the structural trans influence of “N3−”N. The compounds are instable and decompose at room temperature under cleavage of the N–B bonds.

A reaction between [TcNCl2(PPh3)2] and BCl3 does not yield a product with a nitrido bridge. Prolonged heating in dichloromethane results in decomposition of the technetium complex and the formation of (HPPh3)2[TcCl6]. Hydrogen bonds are established between the complex anion and each two counter ions.