bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical investigation of the effect of hypertensive blood pressure on cerebral aneurysm—Dependence of the effect on the aneurysm shape
Authors: Torii Ryo , Oshima Marie , Kobayashi Toshio , Takagi Kiyoshi , Tezduyar Tayfun E.
Published: April 2007

Fluid–structure interaction (FSI) computations of two cerebral aneurysms are carried out under hypertensive and normotensive blood pressures. Hypertensive blood pressure is one of the major risk factors in subarachnoid hemorrhage, which is mostly caused by the rupture of cerebral aneurysm. Since hemodynamic wall shear stress (WSS) is known to play an important role in aneurysm progression, investigating the WSS distribution in conjunction with hypertensive blood pressure is expected to provide a better understanding of aneurysms. The WSS distributions obtained from the simulations show that hypertensive blood pressure considerably affects one of the subjects but not the other. The effect is a wider spreading of the high WSS region on the aneurysm wall, which prevents the wall from weakening. It is also shown that the deformation of the aneurysm wall can alter the flow patterns in the aneurysm to diminish the stagnant flow near the apex, which is linked to the weakening of the wall. The effect of hypertensive blood pressure and wall deformation is shown to be highly dependent on individual aneurysm geometry, and that stresses the importance of subject‐specific simulations. Copyright © 2007 John Wiley & Sons, Ltd.
Selenium‐Containing Heterocycles from Isoselenocyanates: Synthesis of 5‐Amino‐2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐selones
Authors: Sommen Geoffroy L. , Linden Anthony , Heimgartner Heinz
Published: April 2007

The reaction ofS‐methylisothiosemicarbazide hydroiodide (=S‐methyl hydrazinecarboximidothioate hydroiodide;1), prepared from thiosemicarbazide by treatment with MeI in EtOH, and aryl isoselenocyanates5in CH2Cl2affords 3H‐1,2,4‐triazole‐3‐selone derivatives7in good yield (Scheme 2, Table 1). During attempted crystallization, these products undergo an oxidative dimerization to give the corresponding bis(4H‐1,2,4‐triazol‐3‐yl) diselenides11(Scheme 3). The structure of11awas established by X‐ray crystallography.
Triterpene Esters Isolated from Leaves of Maytenus salicifoliaReissek
Authors: de Miranda Roqueline Rodrigues Silva , de Fátima Silva Grácia Divina , Duarte Lucienir Pains , Filho Sidney Augusto Vieira
Published: April 2007

The triterpene ester (3β)‐olean‐18‐en‐3‐yl stearate (1), together with (3β)‐urs‐12‐en‐3‐yl stearate (2), and (3β)‐lup‐20(29)‐en‐3‐yl stearate (3) were isolated from leaves of Maytenus salicifolia Reissek (Celastraceae). The structure of 1, a new compound, including its configuration, was established by 1H, 13C, and DEPT‐135 NMR data, including 2D experiments (HSQC, HMBC, COSY, and NOESY). The molecular mass (692 Da) was confirmed by gas chromatography coupled with mass spectrometry (CG/MS).
Three New Bibenzyl Derivatives from the Chinese Liverwort Marchantia polymorpha L.
Authors: Fang Lei , Guo Huai‐Fang , Lou Hong‐Xiang
Published: April 2007

From the Et2O extract of the Chinese liverwort Marchantia polymorpha L., three new bibenzyl (=1,1′‐(ethane‐1,2‐diyl)bisbenzene) derivatives, compounds 1–3, were obtained, together with the two known compounds marchantin J and perrottetin E. Their structures were established by NMR and HR‐EI‐MS analyses. Polymorphatin A (1) represents a new type of bis[bibenzyl] skeleton, and compound 3 is the first example of a bibenzyl oxidatively coupled to a phenylmethanol.
Stille Cross‐Coupling of a Racemic Planar‐Chiral Ferrocene and Crystallographic Trace Analysis of Catalysis Intermediates and By‐products
Authors: Weber Immo , Heinemann Frank W. , Bakatselos Panagiotis , Zenneck Ulrich
Published: April 2007

A pressure‐controlled procedure for the SN1 reaction of rac‐1‐[(dimethylamino)methyl]‐2‐(tributylstannyl)ferrocene (1) to rac‐1‐(phthalimidomethyl)‐2‐(tributylstannyl)ferrocene (2) was developed. Pd0‐Catalyzed Stille coupling of 2 with iodobenzene afforded rac‐1‐phenyl‐2‐(N‐phthalimidomethyl)ferrocene (5) in 74% yield; after trace enrichment by crystallization of the combined mother liquors, one single crystal of each, 5, catalysis intermediate trans‐iodo(σ‐phenyl)bis(triphenylarsino)palladium(II) (7), trans‐diiodobis(triphenylarsino)palladium(II) (8), and rac‐2,2′‐bis(phthalimidomethyl)‐1,1′‐biferrocene (9) could be isolated by crystal sorting under a microscope and characterized by X‐ray crystal structure analysis. Furthermore, 5 was deprotected to amine (11), which does even survive the Birch reduction to rac‐1‐(aminomethyl)‐2‐(cyclohexa‐2,5‐dienyl)ferrocene (12).
The influence of actual and unrequited interventions
Authors: Dominguez Kathryn M. E. , Panthaki Freyan
Published: April 2007

Intervention operations are used by governments to manage their exchange rates but officials rarely confirm their presence in the market, leading inevitably to erroneous reports in the financial press. There are also reports of what we term, unrequited interventions, interventions that the market expects but do not materialize. In this paper we examine the effects of various types of intervention news on intra‐day exchange rate behaviour. We find that unrequited interventions have a statistically significant influence on returns, volatility and order flow, suggesting that the expectation of intervention, even when governments do not intervene, can affect currency values. Copyright © 2007 John Wiley & Sons, Ltd.
Myths and reality of foreign exchange interventions: an application to Japan
Authors: Ito Takatoshi
Published: April 2007

The objective of this paper is to examine what we know, and do not know, about foreign exchange interventions by the monetary authorities, and to present some new evidence on the Japanese intervention activities. With limited data, efforts are made to determine whether some conventionally made assertions are a myth or a fact. Copyright © 2007 John Wiley & Sons, Ltd.
Discounting the distant future: How much does model selection affect the certainty equivalent rate?
Authors: Groom Ben , Koundouri Phoebe , Panopoulou Ekaterini , Pantelidis Theologos
Published: April 2007

Recent work in evaluating investments with long‐term consequences has turned towards establishing a schedule of Declining Discount Rates (DDRs). Using US data we show that the employment of models that account for changes in the interest rate generating mechanism has important implications for operationalising a theory of DDRs that depends upon uncertainty. The policy implications of DDRs are then analysed in the context of climate change for the USA, where the use of a state space model can increase valuations by 150% compared to conventional constant discounting. Copyright © 2007 John Wiley & Sons, Ltd.
Correcting for bias in retrospective data
Authors: Shachar Ron , Eckstein Zvi
Published: April 2007

When panel data are not available, retrospective data are used in the estimation of dynamic choice models. However, retrospective data are not reliable. Previous studies of voting choices, for example, have shown that respondents misreport their past choices in order to appear more consistent with their current choice. Such retrospective bias leads to inconsistent estimates, especially when there is state dependence in choices. Specifically, observed persistence in retrospective data may be due to (a) true state dependence, (b) unobserved heterogeneity, and (c) retrospective bias in reporting previous choices. Whereas Heckman in his 1981 study deals with (a) and (b), we introduce a method to estimate true state dependence while accounting for both unobserved heterogeneity and retrospective reporting bias. Our method is based on modeling the reporting behavior and integrating it into the estimation. The identification strategy is based on the correlation between the reported previous choices and current exogenous variables. Using data on Israeli voters, we find that the probability that a respondent whose vote intention in 1991 differed from his or her past voting choices would lie about their past choices is 0.23. Copyright © 2007 John Wiley & Sons, Ltd.
Fast evaluation of scaled opposite spin second‐order Møller–Plesset correlation energies using auxiliary basis expansions and exploiting sparsity
Authors: Jung Yousung , Shao Yihan , Head‐Gordon Martin
Published: April 2007

The scaled opposite spin Møller–Plesset method (SOS‐MP2) is an economical way of obtaining correlation energies that are computationally cheaper, and yet, in a statistical sense, of higher quality than standard MP2 theory, by introducing one empirical parameter. But SOS‐MP2 still has a fourth‐order scaling step that makes the method inapplicable to very large molecular systems. We reduce the scaling of SOS‐MP2 by exploiting the sparsity of expansion coefficients and local integral matrices, by performing local auxiliary basis expansions for the occupied‐virtual product distributions. To exploit sparsity of 3‐index local quantities, we use a blocking scheme in which entire zero‐rows and columns, for a given third global index, are deleted by comparison against a numerical threshold. This approach minimizes sparse matrix book‐keeping overhead, and also provides sufficiently large submatrices after blocking, to allow efficient matrix–matrix multiplies. The resulting algorithm is formally cubic scaling, and requires only moderate computational resources (quadratic memory and disk space) and, in favorable cases, is shown to yield effective quadratic scaling behavior in the size regime we can apply it to. Errors associated with local fitting using the attenuated Coulomb metric and numerical thresholds in the blocking procedure are found to be insignificant in terms of the predicted relative energies. A diverse set of test calculations shows that the size of system where significant computational savings can be achieved depends strongly on the dimensionality of the system, and the extent of localizability of the molecular orbitals. © 2007 Wiley Periodicals, Inc. J Comput Chem 2007
Beiträge zur Theorie des mit einer euklidischen Schraubung verknüpften kubischen Nullsystems
Authors: Bereis Rudolf , Brauner Heinrich
Published: April 2007

Mit jeder euklidischen Schraubung ist eine gewisse Punkt‐Ebenenverwandtschaft 3. Grades verknüpft, deren allgemeine Theorie schon vielfach betrachtet wurde. Dieser Beitrag zur Theorie dieser Verwandtschaft, in dem vor allem Methoden der konstruktiven Geometrie Verwendung finden, liefert eine genaue Untersuchung der einer geraden Punktreihe bzw. einem Ebenenbüschel sowie gewissen Strahlmannigfaltigkeiten entsprechenden Gebilde.
Solvent effects on one‐bond BLi coupling constants in boryllithium compounds
Authors: Del Bene Janet E. , Elguero José
Published: April 2007

EOM‐CCSD 11B7Li coupling constants and B chemical shifts have been computed for Li‐diazaborole and its complexes with one H2O or FLi molecule. BLi coupling constants for a model compound H2BLi and its complexes with up to 4 H2O or FLi molecules have also been obtained in an attempt to resolve discrepancies between the computed values of these properties for isolated Li‐diazaborole and experimentally determined values for boryllithium in a THF solution. The presence of solvent molecules increases the ion‐pair character of the BLi bond, with the result that 1J(BLi) decreases systematically as the basicity and the number of solvent molecules increases. In the presence of even a single solvent molecule, the boron chemical shift for Li‐diazaborole increases, and approaches the experimental value. The computed results emphasize the role of the solvent in determining these NMR properties. Copyright © 2007 John Wiley & Sons, Ltd.
Structural determination of seven new triterpenoids from Kadsura heteroclita by NMR techniques
Authors: Wang Wei , Xu Zhengren , Yang Min , Liu Rongxia , Wang Weixing , Liu Peng , Guo Dean
Published: April 2007

Seven new triterpenoids, namely heteroclitalactones G–M (1–7), were isolated from the ethanol extract of the stems of Kadsura heteroclita. Structures of these compounds were characterized by extensive 1D and 2D NMR spectroscopic analyses. Copyright © 2007 John Wiley & Sons, Ltd.
Structural determination of a new 2(3 → 20)abeotaxane with an unusual 13β‐substitution pattern and a new 6/8/6‐ring taxane from Taxus cuspidata
Authors: Huo Changhong , Su Xiaohui , Li Xing , Zhang Xiping , Li Cunfang , Wang Yufang , Shi Qingwen , Kiyota Hiromasa
Published: April 2007

A new 2(3 → 20)abeotaxane with an unusual 13β‐substitution pattern and a new 6/8/6‐ring taxane were isolated from the methanol extract of the needles of Taxus cuspidata. The structures were established as 2α,7β‐diacetoxy‐5α,10β,13β‐trihydroxy‐2(3 → 20)abeotaxa‐4(20), 11‐dien‐9‐one (1) and 2α,5α,7β,9α,13α‐pentahydroxy‐10β‐acetoxytaxa‐4(20),11‐diene (2) on the basis of 1D and 2D NMR spectral data and high‐resolution FAB‐MS analyses. Copyright © 2007 John Wiley & Sons, Ltd.
A proteomic study of the major allergens from yellow jacket venoms
Authors: Kolarich Daniel , Loos Andreas , Léonard Renaud , Mach Lukas , Marzban Gorji , Hemmer Wolfgang , Altmann Friedrich
Published: April 2007

The venoms of stinging insects belong to the most dangerous allergen sources and can cause fatal anaphylactic reactions. Reliable prediction of a patient's risk to anaphylactic reactions is vital, and diagnosis requires the knowledge of the relevant allergens. Recently, a new hyaluronidase ‐like glycoprotein from Vespula vulgaris (Ves v 2b) was identified. This led us to investigate hyaluronidases and also other major allergens from V. germanica and four additional Vespula species. By MALDI‐Q‐TOF‐MS, the new hyaluronidase‐like protein was shown to be the major component of the 43‐kDa band in all Vespula species studied. LC‐ESI‐Q‐TOF‐MS/MS sequencing of Ves g 2a and Ves g 2b facilitated the cloning of their cDNA. Ves v 2b and Ves g 2b turned out to be essentially identical on protein level. Whereas the less abundant “a” form displayed enzymatic activity, the new “b” homologue did not. This is probably caused by amino acid exchanges in the active site, and it raises questions about the physiological role of this protein. Sequence comparisons by MS/MS of antigen 5 and phospholipases from V. vulgaris, germanica, maculifrons, pensylvanica, flavopilosa and squamosa revealed the latter as a taxonomic outlier and led to the discovery of several not previously reported amino acid differences.
The phosphorylation pattern of bovine heart complex I subunits
Authors: Palmisano Giuseppe , Sardanelli Anna Maria , Signorile Anna , Papa Sergio , Larsen Martin R.
Published: April 2007

The phosphoproteome of bovine heart complex I of the respiratory chain has been analysed with a procedure based on nondenaturing gel electrophoretic separation of complex I from small quantities of mitochondria samples, in‐gel digestion, in combination with phosphopeptide enrichment by titanium dioxide and MS. The results, complemented by analyses of purified samples of complex I, showed phosphorylation of five subunits of the complex, 42 kDa (human gene NDUFA10), ESSS, B14.5a (human gene NDUFA7), B14.5b (human gene NDUFC2) and B16.6 (GRIM‐19). MS also revealed the presence of phosphorylated programmed cell death protein 8(AIF) in native and purified samples of complex I analysed. The possible physiological relevance of these findings is discussed.
Proteomic analysis of pancreatic endocrine tumor cell lines treated with the histone deacetylase inhibitor trichostatin A
Authors: Cecconi Daniela , Donadelli Massimo , Rinalducci Sara , Zolla Lello , Scupoli Maria Teresa , Scarpa Aldo , Palmieri Marta , Righetti Pier Giorgio
Published: April 2007

Effects of the histone‐deacetylases inhibitor trichostatin A (TSA) on the growth of three different human pancreatic endocrine carcinoma cell lines (CM, BON, and QGP‐1) have been assessed via dosage‐dependent growth inhibition curves. TSA determined strong inhibition of cell growth with similar IC50 values for the different cell lines: 80.5 nM (CM), 61.6 nM (BON), and 86 nM (QGP‐1), by arresting the cell cycle in G2/M phase and inducing apoptosis. 2DE and nano‐RP‐HPLC‐ESI‐MS/MS analysis revealed 34, 33, and 38 unique proteins differentially expressed after TSA treatment in the CM, BON, and QGP‐1 cell lines, respectively. The most important groups of modulated proteins belong to cell proliferation, cell cycle, and apoptosis classes (such as peroxiredoxins 1 and 2, the diablo protein, and HSP27). Other proteins pertain to processes such as regulation of gene expression (nucleophosmin, oncoprotein dek), signal transduction (calcium‐calmodulin), chromatin, and cytoskeleton organization (calgizzarin, dynein, and lamin), RNA splicing (nucleolin, HNRPC), and protein folding (HSP70). The present data are in agreement with previous proteomic analyses performed on pancreatic ductal carcinoma cell lines (Cecconi, D. et al.., Electrophoresis 2003; Cecconi, D. et al., J. Proteome Res. 2005) and place histone‐deacetylases inhibitors among the potentially most powerful drugs for the treatment of pancreatic tumors.
Proton‐conductive membranes based on blends of polyimides
Authors: Okazaki Yasuhide , Nagaoka Shoji , Kawakami Hiroyoshi
Published: April 2007

We prepared novel proton‐conductivity membranes based on blends of sulfonated polyimides. The blend membranes were prepared from a sulfonated homopolyimide and a sulfonated copolyimide with a solvent‐casting method. The proton conductivities of the blend membranes were measured as functions of the temperature with four‐point‐probe electrochemical impedance spectroscopy. The conductivity of the membranes strongly depended on the sulfonated homopolyimide content and increased with an increase in the content. The proton conductivity of all the blended membranes indicated a higher value than that determined in Nafion at 80 °C, and this may mean that the proton transfer in the blend membranes is responsible for the ionic channels induced by the hydrophobic and hydrophilic domains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1325–1332, 2007
Elevated haptoglobin level of cerebrospinal fluid in Guillain‐Barré syndrome revealed by proteomics analysis
Authors: Chang Kuo‐Hsuan , Lyu Rong‐Kuo , Tseng Mu‐Yun , Ro Long‐Sun , Wu Yih‐Ru , Chang Hong‐Shiu , Hsu Wen‐Chuin , Kuo Hung‐Chou , Huang Chin‐Chang , Chu Chun‐Che , Hsieh Sen‐Yung , Chen Chiung‐Mei
Published: April 2007

Guillain‐Barré Syndrome (GBS) is a rare autoimmune inflammatory polyneuropathy with a high risk of respiratory failure and unclear pathogenesis. Currently, there are no valid biomarkers for diagnosis of GBS. We used 2‐DE and MS to analyze the protein profiles of five pairs of cerebrospinal fluid (CSF) samples of the GBS patients and the patient controls. Three proteins (orosomucoid, haptoglobin and apolipoprotein A‐IV) were up‐regulated, and two proteins (prostaglandin D2 synthase and transthyretin) were down‐regulated in the CSF of the GBS patients. The CSF haptoglobin level, quantified by enzyme‐linked immunosorbent assay, was significantly higher in the GBS patients (12.44 ± 2.70 μg/mL) compared to the chronic inflammatory demyelinating polyradiculoneuropathy (2.82 ± 0.83 μg/mL), viral meningitis (3.57 ± 0.97 μg/mL) and control patients (1.44 ± 0.35 μg/mL, p<0.05). This study indicated that protein profile analysis using a combination of 2‐DE and MS provides an effective strategy for elucidating the pathogenesis and identifying potential CSF biomarkers for GBS. The raised intrathecal synthesis of haptoglobin specifically only in GBS patients, but not in patients with other neurological diseases examined, provides evidence of central nervous system involvement in GBS, and may be used as a potential diagnostic marker for GBS.
Detection of pockets on protein surfaces using small and large probe spheres to find putative ligand binding sites
Authors: Kawabata Takeshi , Go Nobuhiro
Published: April 2007

One of the simplest ways to predict ligand binding sites is to identify pocket‐shaped regions on the protein surface. Many programs have already been proposed to identify these pocket regions. Examination of their algorithms revealed that a pocket intrinsically has two arbitrary properties, “size” and “depth”. We proposed a new definition for pockets using two explicit adjustable parameters that correspond to these two arbitrary properties. A pocket region is defined as a space into which a small probe can enter, but a large probe cannot. The radii of small and large probe spheres are the two parameters that correspond to the “size” and “depth” of the pockets, respectively. These values can be adjusted individual putative ligand molecule. To determine the optimal value of the large probe spheres radius, we generated pockets for thousands of protein structures in the database, using several size of large probe spheres, examined the correspondence of these pockets with known binding site positions. A new measure of shallowness, a minimum inaccessible radius, Rinaccess, indicated that binding sites of coenzymes are very deep, while those for adenine/guanine mononucleotide have only medium shallowness and those for short peptides and oligosaccharides are shallow. The optimal radius of large probe spheres was 3–4 Å for the coenzymes, 4 Å for adenine/guanine mononucleotides, and 5 Å or more for peptides/oligosaccharides. Comparison of our program with two other popular pocket‐finding programs showed that our program had a higher performance of detecting binding pockets, although it required more computational time. Proteins 2007. © 2007 Wiley‐Liss, Inc.
A 1.55 Å resolution X‐ray crystal structure of HEF2/ERH and insights into its transcriptional and cell‐cycle interaction networks
Authors: Jin Tengchuan , Guo Feng , Serebriiskii Ilya G , Howard Andrew , Zhang Yu‐Zhu
Published: April 2007

Functional complementation screens can identify known or novel proteins with important intracellular activities. We have isolated human enhancer of filamentation 2 (HEF2) in a screen to find human genes that promote pseudohyphal growth in budding yeast. HEF2 is identical to enhancer of rudimentary homolog (ERH), a highly conserved protein of 104 amino acids. In silico protein‐interaction mapping implies that HEF2/ERH interacts with transcription factors, cell‐cycle regulators, and other proteins shown to enhance filamentous growth in S. cerevisiae, suggesting a context for studies of HEF2/ERH function. To provide a mechanistic basis to study of HEF2/ERH, we have determined the crystal structure of HEF2/ERH at 1.55 Å. The crystal asymmetric unit contains a HEF2/ERH monomer. The two monomers of the physiological dimer are related by the y, x, –z crystal symmetric operation. The HEF2/ERH structure is characterized by a novel α + β fold, a four‐strand antiparallel β‐sheet with three α‐helixes on one side of the sheet. The β‐sheets from the two monomers together constitute a pseudo‐β‐barrel, and form the center of the functional HEF2/ERH dimer, with a cavity channel at the dimer interface. Docking of this structure to the HEF2/ERH partner protein DCOH/PCD suggests that HEF2/ERH may regulate the oligomeric state of this protein. These data suggest that HEF2/ERH may be an important transcription regulator that also functions in the control of cell‐cycle progression. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Benchmarking of TASSER in the ab initio limit
Authors: Borreguero Jose M. , Skolnick Jeffrey
Published: April 2007

A significant number of protein sequences in a given proteome have no obvious evolutionarily related protein in the database of solved protein structures, the PDB. Under these conditions, ab initio or template‐free modeling methods are the sole means of predicting protein structure. To assess its expected performance on proteomes, the TASSER structure prediction algorithm is benchmarked in the ab initio limit on a representative set of 1129 nonhomologous sequences ranging from 40 to 200 residues that cover the PDB at 30% sequence identity and which adopt α, α + β, and β secondary structures. For sequences in the 40–100 (100–200) residue range, as assessed by their root mean square deviation from native, RMSD, the best of the top five ranked models of TASSER has a global fold that is significantly close to the native structure for 25% (16%) of the sequences, and with a correct identification of the structure of the protein core for 59% (36%). In the absence of a native structure, the structural similarity among the top five ranked models is a moderately reliable predictor of folding accuracy. If we classify the sequences according to their secondary structure content, then 64% (36%) of α, 43% (24%) of α + β, and 20% (12%) of β sequences in the 40–100 (100–200) residue range have a significant TM‐score (TM‐score ≥0.4). TASSER performs best on helical proteins because there are less secondary structural elements to arrange in a helical protein than in a beta protein of equal length, since the average length of a helix is longer than that of a strand. In addition, helical proteins have shorter loops and dangling tails. If we exclude these flexible fragments, then TASSER has similar accuracy for sequences containing the same number of secondary structural elements, irrespective of whether they are helices and/or strands. Thus, it is the effective configurational entropy of the protein that dictates the average likelihood of correctly arranging the secondary structure elements. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Drug block of the hERG potassium channel: Insight from modeling
Authors: Stansfeld Phillip J. , Gedeck Peter , Gosling Martin , Cox Brian , Mitcheson John S. , Sutcliffe Michael J.
Published: April 2007

Many commonly used, structurally diverse, drugs block the human ether‐a‐go‐go‐related gene (hERG) K+channel to cause acquired long QT syndrome, which can lead to sudden death via lethal cardiac arrhythmias. This undesirable side effect is a major hurdle in the development of safe drugs. To gain insight about the structure of hERG and the nature of drug block we have produced structural models of the channel pore domain, into each of which we have docked a set of 20 hERG blockers. In the absence of an experimentally determined three‐dimensional structure of hERG, each of the models was validated against site‐directed mutagenesis data. First, hERG models were produced of the open and closed channel states, based on homology with the prokaryotic K+channel crystal structures. The modeled complexes were in partial agreement with the mutagenesis data. To improve agreement with mutagenesis data, a KcsA‐based model was refined by rotating the four copies of the S6 transmembrane helix half a residue position toward the C‐terminus, so as to place all residues known to be involved in drug binding in positions lining the central cavity. This model produces complexes that are consistent with mutagenesis data for smaller, but not larger, ligands. Larger ligands could be accommodated following refinement of this model by enlarging the cavity using the inherent flexibility about the glycine hinge (Gly648) in S6, to produce results consistent with the experimental data for the majority of ligands tested. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Structure networks of E. coli glutaminyl‐tRNA synthetase: Effects of ligand binding
Authors: Sathyapriya R. , Vishveshwara Saraswathi
Published: April 2007

It is well known that proteins undergo backbone as well as side chain conformational changes upon ligand binding, which is not necessarily confined to the active site. Both the local and the global conformational changes brought out by ligand‐binding have been extensively studied earlier. However, the global changes have been reported mainly at the protein backbone level. Here we present a method that explicitly takes into account the side chain interactions, yet providing a global view of the ligand‐induced conformational changes. This is achieved through the analysis of Protein Structure Networks (PSN), constructed from the noncovalent side chain interactions in the protein. Here, E. coli Glutaminyl‐tRNA synthetase (GlnRS) in the ligand‐free and different ligand‐bound states is used as a case study to assess the effect of binding of tRNA, ATP, and the amino acid Gln to GlnRS. The PSNs are constructed on the basis of the strength of noncovalent interactions existing between the side chains of amino acids. The parameters like the size of the largest cluster, edge to node ratio, and the total number of hubs are used to quantitatively assess the structure network changes. These network parameters have effectively captured the ligand‐induced structural changes at a global structure network level. Hubs, the highly connected amino acids, are also identified from these networks. Specifically, we are able to characterize different types of hubs based on the comparison of structure networks of the GlnRS system. The differences in the structure networks in both the presence and the absence of the ligands are reflected in these hubs. For instance, the characterization of hubs that are present in both the ligand‐free and all the ligand‐bound GlnRS (the invariant hubs) might implicate their role in structural integrity. On the other hand, identification of hubs unique to a particular ligand‐bound structure (the exclusive hubs) not only highlights the structural differences mediated by ligand‐binding at the structure network level, but also highlights significance of these amino acids hubs in binding to the ligand and catalyzing the biochemical function. Further, the hubs identified from this study could be ideal targets for mutational studies to ascertain the ligand‐induced structure–function relationships in E. coli GlnRS. The formalism used in this study is simple and can be applied to other protein‐ligands in general to understand the allosteric changes mediated by the binding of ligands. Proteins 2007. © 2007 Wiley‐Liss, Inc.
Energy structure and micromechanism of photo‐electromotive force effect in V‐doped CdTe crystals
Authors: Gnatenko Yu. P. , Brodyn M. S. , Faryna I. O. , Bukivskij P. M. , Shigiltchoff O. A. , Furyer M. S. , Gamernyk R. V. , Kukhtarev N. , Kukhtareva T.
Published: April 2007

For the first time photo‐electromotive force (photo‐EMF) measurements were carried out for CdTe crystals doped with V atoms as a result of the photogeneration of carriers from deep impurity centers to the conduction band. Tilted geometry was applied that allowed two‐dimensional monitoring of the vi‐ bration source. The CdTe:V crystals were excited by a He–Ne laser with a wavelength of 1.15 μm (ħω = 1.08 eV) and P = 2 mW. The mechanism of the appearance of the holographic current in the CdTe:V crystals taking into account real defect structure was proposed. The frequency dependence of the ac photo‐EMF (holographic) current for the CdTe:V crystals was measured. It was shown that a low cut‐off frequency for a laser intensity I = 0.2 mW/mm2 equals 6.0 kHz, which corresponds to a response time of 26 μs. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Enhanced ultraviolet photoluminescence from V‐doped ZnO thin films prepared by a sol–gel process
Authors: Wei Ling , Zhang Liting , Zhang Yang , Zhang W. F.
Published: April 2007

Undoped and vanadium‐doped ZnO thin films were prepared on single‐crystalline p‐type Si(100) substrates by a sol–gel process and further annealed in an oxygen atmosphere. The influence of vanadium doping on the structural, surface morphological and optical properties of ZnO thin films was investigated by X‐ray diffraction, atomic force microscopy and photoluminescence measurements. Both the undoped and V‐doped ZnO thin films were of polycrystalline hexagonal wurtzite structure with (002)‐preferred orientation. The crystallite size and the root‐mean‐square roughness of V‐doped ZnO are smaller than those of undoped ZnO. Vanadium doping could reduce deep level defects of ZnO and thus strengthen ultraviolet (UV) emission. The peak intensity of UV emission increased with increasing annealing temperature above 400 °C. After annealing at 800 °C, the UV emission for the V‐doped ZnO films was largely enhanced, while the visible emission was distinctly weakened. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of response of second‐order sliding mode controllers to external inputs in frequency domain
Authors: Boiko Igor , Castellanos Ivan , Fridman Leonid
Published: April 2007

Response of systems with the second‐order sliding‐mode (SOSM) control algorithms to an external harmonic excitation is analysed in the frequency domain. The analysis is done via application of the concept of the equivalent gain of a nonlinear function. The equivalent gain is used as a model of propagation of averaged values of signals through nonlinear elements of the system. Two SOSM algorithms: twisting and super‐twisting are analysed. The results are presented in the format of the conventional amplitude and phase frequency response. Copyright © 2007 John Wiley & Sons, Ltd.
Sex differences in the regulation of cocaine and amphetamine‐regulated transcript expression in hypothalamic nuclei of rats by forced swim stress
Authors: Gozen Oguz , Balkan Burcu , Yararbas Gorkem , Koylu Ersin O. , Kuhar Michael J. , Pogun Sakire
Published: April 2007

Cocaine and amphetamine‐regulated transcript (CART) peptides are suggested to play a role in several physiological processes including feeding, reward, neuroendocrine modulation, and the stress response. Although some studies implicate the modulation of CART peptide expression by glucocorticoids, direct evidence relating CART to the stress response is limited. The present study was undertaken to evaluate the possible involvement of CART peptides during acute stress in male and female rats. Forced swim was used as the stress procedure. Following stress, serum adrenocorticotropic hormone (ACTH), and corticosterone (CORT) levels were determined, and CART immunocytochemistry was performed in the paraventricular (PVN) and arcuate (ARC) nuclei of the hypothalamus. Our results depict the following changes: (1) Serum ACTH and CORT levels were increased by stress and CORT levels were higher in female rats than males. (2) Stress modulated the number of CART expressing neurons. The degree and direction of this modulation varied according to the hypothalamic region and the sex of the subject. Forced swim stress increased CART peptide expression significantly in the PVN of female rats. In males, although there was a tendency for an increase in CART‐immunoreactive cells by forced swim stress, the difference was not statistically significant. In the ARC nucleus, forced swim stress did not affect CART peptide expression in either sex. Our results suggest differential and sexually dimorphic modulation of CART expression in the PVN and ARC by forced swim stress. Synapse 61:561–568, 2007. © 2007 Wiley‐Liss, Inc.
Antagonist‐induced increase in 5‐HT1A‐receptor expression in adult rat hippocampus and cortex
Authors: Abbas Syed Y. , Nogueira Maria I. , Azmitia Efrain C.
Published: April 2007

Many receptor antagonists function as reverse agonists on the signaling transduction pathway, but little is known about the action of these drugs on the regulation of receptor expression. Serotonin 1A (5‐HT1A) receptor expression in 5‐HT and serum‐free fetal hippocampal cultures is increased in the presence of a specific 5‐HT1A‐receptor antagonist N‐(2‐(4‐(2‐methoxyphenyl)‐1‐piperazinyl)ethyl)‐N‐(2‐pyridinyl) cyclohexane carboxamide (WAY 100635). To study the plasticity of postsynaptic 5‐HT1A receptors in the presence of antagonist in vivo, adult Sprague Dawley rats were injected i.p. either once or twice daily with a dose of WAY 100635 (3 mg/kg) over a period of 3 days. The 5‐HT1A receptor expression was detected by immunocytochemistry and light microscopy, and the receptor immunoreactivity (IR) in hippocampus subregions was quantitatively assessed by using a comparative computer‐assisted morphometric analysis. Following the daily injections of WAY 100635, a significant increase in 5‐HT1A receptor labeling in hippocampal neurons was recorded. This marked increase in 5‐HT1A receptor expression, which occurred within 4 h after a single injection of WAY 100635, is evident on the somata membrane and dendritic processes of hippocampal and cortex layer V neurons. By contrast, no increase in 5‐HT1A receptor‐IR was observed after multiple daily injections at a low dose (1 mg/kg) of WAY 100635. Our study shows that a single or multiple daily injections of WAY 100635 can result in an increase in 5‐HT1A receptor‐IR. This increase in labeling is consistent with an enhanced expression of the receptor protein. The action of this “inverse agonist” may have clinical importance in disorders such as depression, epilepsy, and Alzheimer's disease in which 5‐HT1A receptor levels are deficient. Synapse 61:531–539, 2007. © 2007 Wiley‐Liss, Inc.
Time‐expanded decision networks: A framework for designing evolvable complex systems
Authors: Silver Matthew R. , de Weck Olivier L.
Published: April 2007

This paper describes the concept of Time‐Expanded Decision Networks (TDNs), a new methodology to design and analyze flexibility in large‐scale complex systems. This includes a preliminary application of the methodology to the design of Heavy Lift Launch Vehicles for NASA's space exploration initiative. Synthesizing concepts from Decision Theory, Real Options Analysis, Network Optimization, and Scenario Planning, TDN provides a holistic framework to quantify the value of system flexibility, analyze development and operational paths, and identify designs that can allow managers and systems engineers to react more easily to exogenous uncertainty. TDN consists of five principle steps, which can be implemented as a software tool: (1) Design a set of potential system configurations; (2) quantify switching costs to create a “static network” that captures the difficulty of switching among these configurations; (3) create a time‐expanded decision network by expanding the static network in time, including chance and decision nodes; (4) evaluate minimum cost paths through the network under plausible operating scenarios; and (5) modify the set of initial design configurations to exploit high‐leverage switches and repeat the process to convergence. Results can inform decisions about how and where to embed flexibility in order to enable system evolution along various development and operational paths. © 2007 Wiley Periodicals, Inc. Syst Eng 10: 167–186, 2007
From the history of the environment to environmental history: A personal understanding of environmental history studies
Authors: Xueqin MEI
Published: April 2007

By and large, there are three kinds of research on environment: the history of environment as a field of natural history studies, the history of environment as within the scope of history of society studies, and environmental history as the study of the relationship between human and nature. The methodological perspective of the relationship between humanity and environmental distinguishes the third from the previous two. From this perspective, when we probe the mutual effects between human and nature, we will stress on their interactions. The new era and the realities of contemporary society foster the rise of environmental history, which has not only theoretical values but also practical significance.
Dressing for power: Rite, costume, and state authority in Ming Dynasty China
Authors: Zujie YUAN
Published: April 2007

As soon as Zhu Yuanzhang, the founder of the Ming Dynasty, assumed the throne, he and his Confucian assistants imposed a system of clothing regulation on the court and society in order to create a hierarchical power structure. As an important aspect of Chinese civilization, the clothing system functioned to form a social hierarchy, to regulate people’s activities, to harmonize the relations among the people, and finally to make a stable society under the close control of the state. The state control in the Ming remained effective until the reigns of Hongzhi (1488–1506) and Zhengde (1506–1521), when commercialization released people’s consumption desires and economic dynamics and caused deregulation of the Ming clothing system, which eventually undermined the state authority.
Philosophical edifi cation and edifi catory philosophy: On the basic features of the Confucian spirit
Authors: Jinglin LI
Published: April 2007

Edification 教化 is one of the central concepts of Confucianism. The metaphysical basis of the Confucian edification is the “philosophical theory” in the sense of rational humanism rather than the “religious doctrine” in the sense of pure faith. Confucianism did not create a system of ceremony and propriety owned by Confucians only. The system of ceremony and propriety on which Confucians depend to carry out their social edification is that of “rites and music,” the common life style of ancient China. After continual metaphysical explanation and elevation, the system of ceremony and propriety and that of rites and music have undergone a sort of ever-evolving historical fluctuation, and evinced a sort of openness and forgiveness comparable to that of any other religious form. Compared with typical religious practices, whose ceremonies and rituals that have their own special fixity and exclusivity, Confucian ceremonies and rituals are fundamentally different. The edification of Confucianism can be labeled as “edification in the sense of philosophy.” As a “philosophy”, Confucianism’s vision did not focus on cognition but on completion and realization.
Logic paradigm in the “Mobian” investigation: From a hermeneutic point of view
Authors: Zhongtang CHENG
Published: April 2007

This article describes the logic paradigm in the “Mobian” 墨辩 (the debate theory of the Mohist school) investigation from the point of view of hermeneutics, discloses the relationship between the overinterpretation tradition in China and the logic paradigm in the “Mobian” investigation, observes the overinterpretation of the “Mobian” by the creators and supporters of the logic paradigm from Liang Qichao and Hu Shi to the modernists, including mathematical logicians, and analyzes Shen Youding’s reflections on the logic paradigm in his later life.
A preliminary discussion on Daoist bionomy: On the basis of Chen Yingning’s philosophy of immortals
Authors: Zhongjian MOU
Published: April 2007

From the modern point of view, the Daoist regimen culture in China is actually a kind of oriental bionomy. Although it is less developed than the Western life sciences in terms of details and techniques, it has unique advantages in terms of its comprehensive grasp and dynamic observation of life, as well as its emphasis on the development of life potentiality and on the self adjustment and improvement of living bodies. Chen Yingning reestablished a Daoist bionomy through Xianxue 仙学 (Philosophy of Immortals) which involves religious faith, philosophy and sciences, leaving us a valuable legacy. To establish a new bionomy system required by the modern society through learning from the Daoist bionomy, the academic circle has to seriously explore the four issues: (1) at the level of faith, to turn the Daoist faith in deities and gods into a pursuit of ideal personality; (2) with respect to the principles of regimen, to extend the dual cultivation into a kind of universal concept; (3) as with the way of regimen, to learn from the regimen thought of Daoism and combine the inner cultivation with the outer one, and static exercise with dynamic exercise; and (4) with regard to the ways of treatment of diseases, to combine the Daoist medicine with the Western medicine.
Cogito: From Descartes to Sartre
Authors: Weimin MO
Published: April 2007

Cogito, as the first principle of Descartes’ metaphysical system, initiated the modern philosophy of consciousness, becoming both the source and subject of modern Western philosophical discourse. The philosophies of Maine de Biran, Kant, Husserl, Heidegger, Sartre, Merleau-Ponty, and others developed by answering the following questions? Is consciousness substantial or not? Does consciousness require the guarantee of a transcendental subject? Is Cogito epistemological or ontological? Am I a being-for-myself or a being-for-others? Outlining the developmental history of the idea of Cogito from Descartes to Sartre is important for totally comprehending the evolution and development of Western philosophy.
Perthes disease: A survey of management amongst members of the British Society for Children's Orthopaedic Surgery (BSCOS)
Authors: Annamalai Suresh Kumar Masilamani , Buckingham Rachel , Cashman John
Published: April 2007

The treatment of Legg-Calvé-Perthes disease remains controversial. The aim of this survey was to ascertain the current management strategies of this condition amongst UK paediatric orthopaedic surgeons, with particular regard to containment procedures in the fragmentation phase. Questionnaires were distributed at the January 2006 meeting of the British Society for Children's Orthopaedic Surgery (BSCOS) and was posted to all absent members. The results showed a great deal of variability not only in the treatment of Perthes disease, but also in the decision-making processes. Consideration must now be given to a carefully constructed national multi-centre prospective randomised controlled study into the optimum management of this disease
Family developmental risk factors among adolescents with disabilities and children of parents with disabilities
Authors: Hogan Dennis P. , Shandra Carrie L. , Msall Michael E.
Published: April 2007

This paper investigates how the learning environments and family dynamics differ if households have a child with a disability or a parent with a disability. Using data from the National Longitudinal Survey of Youth 1997, results indicate that children with disabilities experience similar learning environments as other children, but have somewhat weaker relationships with their parents. In two‐parent families, maternal disability lowers parents’ school involvement and is associated with a less enriching home environment. Paternal disability reduces maternal monitoring and positive family activities possibly because mothers divert care‐giving resources from their children to their male partners. Children in mother‐headed households experience learning environments and family dynamics that are similar regardless of their own disability status or that of their mothers, but these outcomes are markedly inferior to those of children growing up in two‐parent households. Future research on adolescent development should consider the disability status of children and parents, with particular attention to patterns of gendered care‐giving in American families.
New tensio‐active molecules stabilize a human G protein‐coupled receptor in solution
Authors: Damian Marjorie , Perino Sandrine , Polidori Ange , Martin Aimée , Serre Laurence , Pucci Bernard , Banères Jean-Louis
Published: April 2007

Structural characterization of membrane proteins is hampered by the instability of the isolated proteins in detergent solutions. Here, we describe a new class of phospholipid‐like surfactants that stabilize the G protein‐coupled receptor, BLT1. These compounds, called C13U9, C13U19, C15U25 and C17U16, were synthesized by radical polymerization of Tris(hydroxymethyl) acrylamidomethane in the presence of thioglycerol, first endowed with two hydrocarbon chains with variable lengths (13–17 carbon atoms), as transfer reagent. C13U19, C17U16 or C15U25 significantly enhanced the stability of BLT1 in solution compared to what was obtained with common detergents. These molecules therefore represent a promising step towards the structural characterization of BLT1 and possibly other membrane proteins.
The peroxisomal protein import machinery
Authors: Platta Harald W. , Erdmann Ralf
Published: April 2007

Peroxisomes are unique organelles whose physiological functions vary depending on the cellular environment or metabolic and developmental state of the organism. These changes in enzyme content are accomplished by the dynamically operating membrane and matrix protein import machineries of peroxisomes that rely on the concerted function of at least 20 peroxins. The import of folded matrix proteins is mediated by cycling receptors that shuttle between the cytosol and peroxisomal lumen. Receptor release back to the cytosol represents the ATP‐dependent step of peroxisomal matrix protein import, which consists of two energy‐consuming reactions: receptor ubiquitination and dislocation.