bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical conductivity, photoconductivity, and optical properties of poly(1,4‐diaminoanthraquinone) organic semiconductor for optoelectronic applications
Authors: Yakuphanoglu Fahrettin , Şenkal B. Filiz 
Published: April 2008

AbstractThe electrical conductivity and optical properties of the poly(1,4‐diaminoanthraquinone) [poly(1,4‐DAAQ)] have been investigated. The electrical conductivity of the polymer increases with temperature and room temperature conductivity was found to be 2.68  10−5 S cm−1. The optical band gap of the polymer is 1.87 eV due to the direct optical transitions. The photoconductivity of the polymer is higher than that of dark conductivity. When the light is switched on, the resistance decreases abruptly and when it is switched off, the resistance increases. This confirms that the polymer is a photoconductive material. The obtained results indicate that the poly(1,4‐DAAQ) is a photoconducting organic semiconductor with photovoltaic and dark current properties. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and preparation of biodegradable and visible light crosslinkable unsaturated fumarate‐based networks for biomedical applications
Authors: Doulabi Azadeh S. Hashemi , Mirzadeh Hamid , Imani Mohammad , Sharifi Shahriar , Atai Mohammad , Mehdipour‐Ataei Shahram 
Published: April 2008

AbstractBiodegradable polymers have currently attracted high interest as ideal carriers in drug delivery and tissue engineering applications. In situ forming devices based on these materials will synergistically provide the advantages of the customary prefabricated devices as well as ease of administration. To acheive these objectives, optically transparent and biodegradable macromers based on poly(ethylene glycol) and fumaric acid copolymers were synthesized using propylene oxide as a different proton scavenger to enhance in situ photocrosslinking capability. The macromers in different compositions were then photocured for 300 sec in the presence of a visible light initiator/accelerator couple and also a reactive diluent. Characterization of the macromers and the resulting networks were performed using different spectroscopic, chromatographic, physical, and thermal analysis techniques. The resulted shrinkage strain of the macromers upon photocuring was studied using the bounded disk technique, and initial shrinkage strain rates were obtained by numerical differentiation. Our results suggest that the compositions based on these unsaturated aliphatic polyesters are potentially useful to develop injectable, in situ photocrosslinkable carriers for drug and cell delivery applications. Copyright © 2008 John Wiley & Sons, Ltd.
Wilms tumour in Sudan
Authors: Abuidris Dafalla O. , Elimam Mohammed E. , Nugud Faisal M. , Elgaili Elgaili M. , Ahmed Mohamed E. , Arora Ramandeep S. 
Published: April 2008

AbstractBackgroundWilms tumour is one of the commonest childhood solid tumours which has an excellent outlook in the developed world with 5‐year overall survival exceeding 90%. There is little information from Sudan regarding Wilms tumour.ProcedureRecords of patients with Wilms tumour diagnosed and treated at Institute of Nuclear Medicine, Molecular Biology and Oncology (INMO) in the University of Gezira from May 1999 to June 2007 were reviewed.ResultsThirty‐seven children presented at a mean age of 4.1 years (range 2 months–13 years). The male to female ratio was 0.9–1. Abdominal swelling or mass was the commonest symptom. There was 1 child with Stage I (2.7%), 7 with stage II (18.9%), 25 with Stage III (67.6%) and 4 with Stage IV (10.8%). Following diagnosis 27% of children did not receive further treatment (5.4% died prior to treatment, 5.4% were not able to finance treatment and for the rest 16.2% no cause was identified). More than half of the children did not have a nephrectomy and only 4 (11%) completed treatment.ConclusionsThe poor outlook is related to several factors. Delayed presentation, poor awareness of treatment options, lack of finances, no provision of food, lodging and transport, absence of paediatric trained staff are the obstacles to better outcomes. Empowering parents with information, giving chemotherapy prior to nephrectomy, training staff and establishing links with a tertiary cancer centre in the developed world are some of the options to improve survival. Pediatr Blood Cancer 2008;50:1135–1137. © 2008 Wiley‐Liss, Inc.
The potential role of purine‐rich element binding protein (PUR) α as a novel treatment target for hormone‐refractory prostate cancer
Authors: Inoue Takahiro , Leman Eddy S. , Yeater David B. , Getzenberg Robert H. 
Published: April 2008

AbstractBACKGROUNDHormonal therapy for advanced prostate cancer is typically effective at first, but almost all men suffer refractory disease which often is life threatening. The nuclear matrix comprises not only of the structural elements of the nucleus, but is associated with many components of the molecular machinery. Our aim is to find novel targets for the treatment of hormone‐refractory prostate cancer (HRPC) by focusing on the composition of the nuclear matrix proteins (NMPs).METHODSLN96 cells were established at our Institution after long‐term culturing of LNCaP cells under androgen deprived conditions. The composition of NMPs of LNCaP cells and LN96 cells were analyzed by two‐dimensional (2D) electrophoresis and spots differentially expressed were investigated by mass spectrometry for identification. Among the spots identified, we analyzed the potential functional role of the identified proteins in prostate cancer cells by establishing stable overexpressed cells.RESULTSWe found that purine‐rich element binding protein (PUR)α was significantly repressed not only in NMPs but also in total protein and mRNA levels of LN96 cells in comparison to LNCaP cells under the same steroid deprived conditions. Moreover, PURα was decreased in its expression both at the protein and mRNA levels in the androgen‐independent prostate cancer cell lines, PC3 and DU145 in comparison to LNCaP cells. Stably overexpressing PURα in PC3 and DU145 cells negatively regulates cell proliferation, resulting in decreases in PCNA expression.CONCLUSIONFurther dissection of the role of PURα in cell growth regulation may reveal a novel target for HRPC. Prostate 68:1048–1056, 2008. © 2008 Wiley‐Liss, Inc.
Protease‐activated receptor‐1 upregulates fibroblast growth factor 7 in stroma of benign prostatic hyperplasia
Authors: Wang Wenbin , Zhang Xiaotun , Mize Gregory J. , Takayama Thomas K. 
Published: April 2008

AbstractBACKGROUNDBenign prostatic hyperplasia (BPH) is characterized by abnormal epithelial and stromal proliferation causing urinary obstruction. Prostate growth is regulated by a variety of growth factors secreted from the stroma, including fibroblast growth factor 7 (FGF‐7), a potent epithelial‐specific growth factor which is increased in hyperplastic prostate. However, the mediator(s) of FGF‐7 over‐expression is unclear. Protease‐activated receptor‐1 (PAR‐1) is a G‐protein coupled receptor known to induce multiple biological processes, but its effect on BPH pathogenesis is mostly unknown. The aim of this study was to investigate the role of PAR‐1 as a mediator of BPH development.METHODSPAR‐1 expression was investigated in BPH and normal prostate tissues by immunohistochemistry. Prostate stromal cells were isolated from BPH specimens, cultured and immunohistochemically characterized. Cultured stromal cells were stimulated with PAR‐1 agonists, and extracellular‐signal regulated kinase (ERK1/2) activation and cell proliferation were examined. PAR‐1 mediated FGF‐7 production by cultured stromal cells was assessed by RT‐PCR and immunoassays, and verified by small interfering RNA (siRNA).RESULTSPAR‐1 expression was increased in BPH stroma. In stromal cells isolated from BPH tissues, PAR‐1 agonists activated ERK1/2 in a time‐ and concentration‐dependent manner and with resultant enhanced cell proliferation. Pertussis toxin‐sensitive G protein/(βγ‐subunits)‐phosphatidylinositol 3‐kinase and protein kinase C pathways were involved in ERK1/2 phosphorylation. PAR‐1 activation strikingly induced FGF‐7 production from cultured stromal cells mediated predominantly via ERK1/2 signaling pathway, and PAR‐1 siRNA decreased the elicited FGF‐7 upregulation.CONCLUSIONSThe expression and function of PAR‐1 in BPH stroma indicate PAR‐1 may play important roles in BPH pathogenesis. Prostate 68:1064–1075, 2008. © 2008 Wiley‐Liss, Inc.
X‐ray structures of Sap1 and Sap5: Structural comparison of the secreted aspartic proteinases from Candida albicans
Authors: Borelli Claudia , Ruge Elisabeth , Lee Jung Hoon , Schaller Martin , Vogelsang Alexandra , Monod Michel , Korting Hans Christian , Huber Robert , Maskos Klaus 
Published: April 2008

AbstractProteolytic activity is an important virulence factor for Candida albicans (C. albicans). It is attributed to the family of the secreted aspartic proteinases (Saps) from C. albicans with a minimum of 10 members. Saps show controlled expression and regulation for the individual stages of the infection process. Distinct isoenzymes can be responsible for adherence and tissue damage of local infections, while others cause systemic diseases. Earlier, only the structures of Sap2 and Sap3 were known. In our research, we have now succeeded in solving the X‐ray crystal structures of the apoenzyme of Sap1 and Sap5 in complex with pepstatin A at 2.05 and 2.5 Å resolution, respectively. With the structure of Sap1, we have completed the set of structures of isoenzyme subgroup Sap1‐3. Of subgroup Sap4‐6, the structure of the enzyme Sap5 is the first structure that has been described up to now. This facilitates comparison of structural details as well as inhibitor binding modes among the different subgroup members. Structural analysis reveals a highly conserved overall secondary structure of Sap1‐3 and Sap5. However, Sap5 clearly differs from Sap1‐3 by its electrostatic overall charge as well as through structural conformation of its entrance to the active site cleft. Design of inhibitors specific for Sap5 should concentrate on the S4 and S3 pockets, which significantly differ from Sap1‐3 in size and electrostatic charge. Both Sap1 and Sap5 seem to play a major part in superficial Candida infections. Determination of the isoenzymes' structures can contribute to the development of new Sap‐specific inhibitors for the treatment of superficial infections with a structure‐based drug design program. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Structure‐based tailoring of compound libraries for high‐throughput screening: Discovery of novel EphB4 kinase inhibitors
Authors: Kolb Peter , Kipouros Catherine Berset , Huang Danzhi , Caflisch Amedeo 
Published: April 2008

AbstractHigh‐throughput docking is a computational tool frequently used to discover small‐molecule inhibitors of enzymes or receptors of known three‐dimensional structure. Because of the large number of molecules in chemical libraries, automatic procedures to prune multimillion compound collections are useful for high‐throughput docking and necessary for in vitro screening. Here, we propose an anchor‐based library tailoring approach (termed ALTA) to focus a chemical library by docking and prioritizing molecular fragments according to their binding energy which includes continuum electrostatics solvation. In principle, ALTA does not require prior knowledge of known inhibitors, but receptor‐based pharmacophore information (hydrogen bonds with the hinge region) is additionally used here to identify molecules with optimal anchor fragments for the ATP‐binding site of the EphB4 receptor tyrosine kinase. The 21,418 molecules of the focused library (from an initial collection of about 730,000) are docked into EphB4 and ranked by force‐field‐based energy including electrostatic solvation. Among the 43 compounds tested in vitro, eight molecules originating from two different anchors show low‐micromolar activity in a fluorescence‐based enzymatic assay. Four of them are active in a cell‐based assay and are potential anti‐angiogenic compounds. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Lessons from TGN1412 and TARGET: implications for observational studies and meta‐analysis
Authors: Senn Stephen 
Published: April 2008

AbstractTwo very different studies are examined: the first, a very large trial in osteoarthritis (the so‐called TARGET study) and the second a very small ‘first‐in‐man’ study of the monoclonal antibody TGN1412. In each trial the unbiased estimate of the treatment effect is not efficient and in con sequence the efficient estimate is not unbiased. In the case of the large trial it seems reasonable that unbiased estimation is desirable but in the case of the small trial it leads to absurd conclusions. These two cases are examined in detail and some general lessons for the analysis of clinical trials and observational studies and collections of studies are drawn. Copyright © 2008 John Wiley & Sons, Ltd.
Antioxidant and antiinflammatory activities of Sideritis perfoliata subsp. perfoliata (Lamiaceae)
Authors: Charami Maria‐Thiresia , Lazari Diamanto , Karioti Anastasia , Skaltsa Helen , Hadjipavlou‐Litina Dimitra , Souleles Christos 
Published: April 2008

AbstractSideritis perfoliata L. subsp. perfoliata is a plant widely used in folk medicine in Greece since antiquity because of its antiinflammatory, antirheumatic, antiulcer, digestive and vasoprotective properties.Phytochemical investigations of the polar extracts afforded four flavonoid glycosides, four phenylpropanoic glycosides, caffeic acid and one iridoid, ajugoside. Reactive oxygen species (ROS) are implicated in the aetiology of several inflammatory processes. In the present study polar fractions and isolated compounds from S. perfoliata subsp. perfoliata were evaluated for their antioxidant activity using DPPH spectrophotometric and TBA lipid peroxidation assays, as well as for their antiinflammatory activity using the soybean lipoxygenase bioassay.All extracts and isolated compounds showed significant antioxidant and inhibitory activity against soybean lipoxygenase. These findings give support to the ethnopharmacological use of the plant in the treatment of several inflammatory ailments. Copyright © 2008 John Wiley & Sons, Ltd.
Inhibitory effects of Angelicae Gigantis Radix on osteoclast formation
Authors: Kil Jong‐Seob , Kim Myung‐Gyou , Choi Hye Mi , Lim Jong‐Pil , Boo Yungmin , Kim Ee‐Hwa , Kim Jeung‐Beum , Kim Hye Kyung , Leem Kang‐Hyun 
Published: April 2008

AbstractAngelicae Gigantis Radix (AGR) is one of the most widely used herbal medications. AGR is the dried root of Angelica gigas Nakai (Umbelliferae), which is known as Korean angelica. This study investigated the effects of AGR on osteoclast formation using primary bone marrow cells. TNF‐α treatment increased tartrate‐resistant acid phosphatase (Trap) positive cells and Trap activity in bone marrow cells. However, AGR significantly decreased both TNF‐α‐induced Trap positive cells and Trap activity. RT‐PCR analyses revealed that AGR decreased mRNA levels of Trap and matrix metalloproteinase‐9 in TNF‐α‐treated bone marrow cells. In addition, AGR decreased TNF‐α‐induced activation of NF‐κB. These results suggest that AGR has an inhibitory effect on the formation of osteoclasts and its effect is partially related to the NF‐κB pathway. Copyright © 2008 John Wiley & Sons, Ltd.
Antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component, 1,2,3,4,6‐Penta‐O‐galloyl‐β‐d‐glucose
Authors: Piao Xiangshu , Piao Xiang‐Lan , Kim Hyun Young , Cho Eun Ju 
Published: April 2008

AbstractThe antioxidative activity of geranium (Pelargonium inquinans Ait) and its active component was investigated under in vitro and cellular oxidative stress models. The MeOH extract, and n‐hexane, EtOAc, BuOH and H2O fractions from geranium showed strong 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging effects and protective potential from oxidative damage by the radical generator, 2,2′‐azobis (2‐amidinopropane) dihydrochloride (AAPH) in renal epithelial LLC‐PK1 cells. In particular, the EtOAc fraction exerted the strongest antioxidative potential in not only the in vitro but also in the cellular system. It suggests that the antioxidative activity of geranium is attributed mainly to components from the EtOAc fraction. Furthermore, the active component, 1,2,3,4,6‐penta‐O‐galloyl‐β‐d‐glucose (PGG), was identified from the EtOAc fraction by the bioassay‐linked fractionation method. It displayed a potent antioxidant effect against the DPPH radical, showing an IC50 value of 1.14 µg/mL. Moreover, the compound recovered the cell viability declined by AAPH treatment significantly and dose‐dependently, implying a protective role against cellular oxidative damage. The present study suggests that geranium has an excellent antioxidative potential and that PGG from geranium is considered to be the active component with an antioxidative effect. Copyright © 2008 John Wiley & Sons, Ltd.
On the use of shear‐dependent turbulent length‐scales
Authors: Mauritsen Thorsten , Enger Leif 
Published: April 2008

AbstractWe investigate the behaviour of the recently proposed shear‐dependent turbulent length‐scale in the neutrally stratified surface layer. It is found that close to ground, this shear‐dependent length‐scale is proportional to height, and thus, equivalent to the law of the wall. We speculate that the law of the wall could be just a special case of applying the shear‐length to near‐surface flows. Copyright © 2008 Royal Meteorological Society
The influence of formamide (model of protein unit) on the intramolecular proton transfer in the DNA simple base guanine: A density functional theory study
Authors: Zhang An‐Guo , Zhang Hui , Zhou Zheng‐Yu , Jia Zhao‐Kun , Hou Rui‐Yan 
Published: April 2008

AbstractFor the purpose of investigating the influence of protein unit on the intramolecular proton transfer (IPT) reactions in the simple base guanine, a simple model (formamide) of peptides is designed to biological system investigations, and five complexes of formamide–guanine (FG1, FG2, FG3, FG4, and FG5) are determined at the B3LYP/6‐311++G(d,p) level of theory. For comparison, HF and MP2 methods are also used in this paper. The proton transfer (PT) reaction processes of guanine and FGs have been investigated employing the B3LYP/6‐311++G(d,p) level of theory. The selected thermodynamic and kinetic parameters, such as the activation energies (Ea), changes of enthalpy (ΔH) and changes of free energies (ΔG), as well as the equilibrium constants (Kp) for those reaction processes, have also been obtained by calculational means. The calculated results indicate that the assisted and protected effects of formamide on IPT in guanine are site‐dependent. CH1 is the lowest activation energy needed PT process no matter where the formamide molecule is located in. The activation energy of CH1 with formamide in S2 is the lowest one (153.3 KJ/mol), whereas the one of CH5 with formamide in S5 is the highest (318.3 KJ/mol). © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Representation of Kohn–Sham free atom eigenfunctions by Slater‐type orbitals
Authors: Romanowski Zbigniew , Jalbout Abraham F. 
Published: April 2008

AbstractSlater‐type orbitals are applied to represent the numerically obtained Kohn–Sham eigenfunction of free atom. The algorithm evaluating the nonlinear expansion coefficients of this approximation is described. Standard iterative solution of Kohn–Sham equation to obtain the nonlinear expansion coefficients is avoided and replaced by the projection method. First, the eigenfunction is obtained in the B‐spline space based on the Galerkin formulation of the finite element method. Then, based on the density functional theory, the conditions are formulated, which leads to the set of nonlinear equations. The proposed algorithm is general and can be applied for any atomic Kohn–Sham eigenfunction. As an examplary application of the proposed algorithm, the set of nonlinear equations is derived for occupied states of N, Al, Ga, and In atoms. The expansion coefficients, obtained for these atoms, are evaluated numerically by Newton procedure and listed in the tables. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Test and modification of the van der Waals' radii employed in the default PCM model
Authors: Mu Wei‐Hua , Chasse Gregory Adam , Fang De‐Cai 
Published: April 2008

AbstractHigh level ab initio calculations at the B3LYP/6‐311++G(d,p) and MP2(full)/6‐311++G(d,p) levels employing PCM/UA0 model with different van der Waals' radii for the systems that contain lithium atoms have been carried out, in order to see if the van der Waal's radius for lithium atom employed in the default PCM/UA0 model is proper or not. Comparative analysis indicated that the van der Waals' radius for alkali metals, especially for lithium atom in the default PCM/UA0 model within the Gaussian 03 package, is too small, which causes erroneous redundant imaginary frequencies (RIFs) in the characterization of Li‐containing compounds from moderate to big size. A new set of van der Waals' atomic radii based on QTAIM, proposed by Bader, was suggested for a better choice in the characterization of compounds containing alkali metals, for which it can effectively avoid the erroneous RIFs for corresponding geometries of these Li‐containing systems. © 2008 Wiley Periodicals, Inc. Int. J. Quantum Chem, 2008
How to get more mileage from randomness extractors
Authors: Shaltiel Ronen 
Published: April 2008

AbstractLet 𝒞 be a class of distributions over Bn. A deterministic randomness extractor for 𝒞 is a function E : BnarBm such that for any X in 𝒞 the distribution E(X) is statistically close to the uniform distribution. A long line of research deals with explicit constructions of such extractors for various classes 𝒞 while trying to maximize m.In this paper we give a general transformation that transforms a deterministic extractor E which extracts “few” bits into an extractor E′ that extracts “almost all the bits present in the source distribution.” More precisely, we prove a general theorem saying that if E and 𝒞 satisfy certain properties, then we can transform E into an extractor E′.Our methods build on (and generalize) a technique of Gabizon et al. [FOCS (2004) 394–403] that presents such a transformation for the very restricted class 𝒞 of “oblivious bit‐fixing sources.” The high level idea is to find properties of E and 𝒞 which allow “recycling” the output of E so that it can be “reused” to operate on the source distribution. An obvious obstacle is that the output of E is correlated with the source distribution.Using our transformation we give an explicit construction of a two‐source extractor E : Bn × BnarBm such that for every two independent distributions X1 and X2 over Bn with min‐entropy at least k = (1/2 + δ)n and eps ≤ 2, E(X1,X2) is eps‐close to the uniform distribution on m = 2k ‐ Cδ log(1/eps) bits. This result is optimal except for the precise constant Cδ and improves previous results by Chor and Goldreich [SICOMP 17 (1988) 230–261], Vazirani [Combinatorica 7 (1987) 375–392], and Dodis et al. [RANDOM (2004) 334–344].We also give explicit constructions of extractors for samplable distributions that extract many bits even out of “low‐entropy” samplable distributions. These constructions rely on average case hardness assumptions and extend some previous results by Trevisan and Vadhan [FOCS (2000) 32–42] which give such extractors only for distributions with “high entropy.” © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2008