bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suzuki–Miyaura and Related Cross‐Couplings in Aqueous Solvents Catalyzed by Di(2‐pyridyl)methylamine‐Palladium Dichloride Complexes
Authors: Nájera Carmen , Gil‐Moltó Juan , Karlström Sofia 
Published: December 2004

AbstractDi(2‐pyridyl)methylamine‐based palladium dichloride complexes 4 are versatile catalysts for different types of cross‐coupling reactions in water or aqueous solvents under aerobic conditions. The Suzuki–Miyaura reaction of arylboronic acids can be performed with bromoarenes under water reflux using K2CO3 as base or at room temperature or 60 °C in aqueous methanol using KOH as base. For aryl chlorides the corresponding cross‐couplings with arylboronic acids can be carried out in refluxing water with K2CO3 as base and TBAB as additive to provide biaryls and heterobiaryls. Arylboronic acids react with benzylic chlorides and allylic substrates such as chlorides, acetates or carbonates also in refluxing water with K2CO3 as base or at room temperature in aqueous acetone and KOH as base, to give diarylmethanes and arylpropenes. Trimethylboroxine and alkylboronic acids are coupled with bromo‐ and chloroarenes under water at reflux with K2CO3 as base and TBAB as additive to furnish methyl‐ and butylarenes. These cross‐couplings have also been performed in shorter times under microwave irradiation. Several important intermediates such as, 4′‐methylbiphenyl‐2‐carbonitrile, 4‐biphenylacetic acid, 3‐(3‐methylphenyl)benzoic acid, 4,5‐diphenyl‐2‐methyl‐3(2H)pyridazinone and 2‐(4′‐fluorobenzyl)thiophene have been prepared under aqueous and aerobic conditions in good yields.
Nickel‐Catalyzed Cross‐Couplings of Unactivated Alkyl Halides and Pseudohalides with Organometallic Compounds
Authors: Netherton Matthew R. , Fu Gregory C. 
Published: December 2004

AbstractUntil recently, there had been a widespread perception that unactivated, β‐hydrogen‐containing alkyl halides/pseudohalides are not suitable partners for nickel‐catalyzed coupling reactions. During the past several years, a number of reports have dispelled this misconception by demonstrating that a diverse array of electrophiles and organometallic reagents can in fact be efficiently cross‐coupled.
Nickel‐2,2′‐Bipyridyl and Palladium‐Triphenylphosphine Complex Promoted Synthesis of New π‐Conjugated Poly(2‐hexylbenzotriazole)s and Characterization of the Polymers
Authors: Tanimoto Akitoshi , Yamamoto Takakazu 
Published: December 2004

AbstractA nickel(0) complex (Ni‐bpy) promoted dehalogenative polycondensation of 4,7‐dibromo‐2‐hexylbenzotriazole gives the new π‐conjugated polymer, polybenzotriazole [P(BTz)]. Palladium‐triphenylphosphine [Pd(PPh3)4] catalyzed the copolymerization between 4,7‐dibromo‐2‐hexylbenzotriazole with 2,5‐diethynyl‐1,4‐dihexyloxybenzene and 9,9′‐dihexylfluorene‐2,7‐bis(trimethylene borate) to give the corresponding polymers P(BTz‐AE) and P(BTz‐F), respectively. The number average molecular weights, Mn, of the polymers ranged from 3000 to 7400. P(BTz‐AE) showed a photoluminescence (PL) peak at 500 nm in CHCl3 with a high quantum yield of PL (87%).
Hard sphere compressibility factors for equation of state development
Authors: Wu Guang‐Wen , Sadus Richard J. 
Published: December 2004

AbstractNew molecular simulation data are reported for the compressibility factors of hard spheres covering the isotropic liquid, metastable fluid and solid ranges of density. These data provide a comprehensive set of values for the development of hard‐sphere equations of state. In particular, they represent a substantial increase in the data available at high isotropic liquid densities. A comparison is reported with examples of accurate hard sphere equations. In contrast to literature comparisons, which are weighted towards existing lower density data, including these new higher density data indicates that the overall accuracy of current equations of state is considerably less than previously reported. © 2004 American Institute of Chemical Engineers AIChE J, 51: 309–313, 2005
Wax precipitation modeled with many mixed solid phases
Authors: Heidemann Robert A , Madsen Jesper , Stenby Erling H. , Andersen Simon I. 
Published: December 2004

AbstractThe behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows substantial amounts of the lighter component dissolved in the heavier solid. Calculations have been performed taking into account the recrystallization of the solid alkanes into a second solid form. The Coutinho UNIQUAC model has been used to describe the lower‐temperature solid phases. The higher‐temperature mixed solid phase has been assumed to be either an ideal solution or to be described by Coutinho's Wilson activity coefficient model. This procedure accounts for more of the known behavior of mixed n‐alkane solids. Comparison is also made with results assuming that all of the solid phases, both high‐temperature and low‐temperature forms, are pure. Model calculations compare well with the data of Pauly et al. for C18 to C30 waxes precipitating from n‐decane solutions. © 2004 American Institute of Chemical Engineers AIChE J, 51: 290–308, 2005
Ullrich congenital muscular dystrophy: Connective tissue abnormalities in the skin support overlap with Ehlers–Danlos syndromes
Authors: Kirschner Janbernd , Hausser Ingrid , Zou Yaqun , Schreiber Gudrun , Christen Hans‐Jürgen , Brown Susan C. , Anton‐Lamprecht Ingrun , Muntoni Francesco , Hanefeld Folker , Bönnemann Carsten G. 
Published: December 2004

AbstractUllrich congenital muscular dystrophy (UCMD) is caused by mutations in the three genes coding for the alpha chains of collagen VI and characterized by generalized muscle weakness, striking hypermobility of distal joints in conjunction with variable contractures of more proximal joints, and normal intellectual development. The diagnosis is supported by abnormal immunoreactivity for collagen VI on muscle biopsies. As patients with UCMD show clinical characteristics typical of classical disorders of connective tissue such as Ehlers–Danlos syndromes (EDS), we investigated the ultrastructure of skin biopsy samples from patients with UCMD (n=5). Electron microscopy of skin biopsies revealed ultrastructural abnormalities in all cases, including alterations of collagen fibril morphology (variation in size and composite fibers) and increase in ground substance, which resemble those seen in patients with EDS. Our findings suggest that there is a true connective tissue component as part of the phenotypic spectrum of UCMD and that there is considerable clinical as well as morphological overlap between UCMD and classic connective tissue disorders. © 2004 Wiley‐Liss, Inc.
A Rational Approach to Maximize Success Rate in Target Discovery
Authors: Schneider Martin 
Published: December 2004

AbstractTo overcome the problem of high attrition rates in the drug discovery process, an efficient strategy how to identify, select, characterize and validate the most suitable drug targets before embarking on the resource‐intense steps of lead discovery and lead optimization is mandatory. We have implemented such an efficient strategy consisting of (i) Target Selection based on gene expression analyses of drugable target genes in clinical samples and relevant in vitro model systems, to identify candidate targets with a specific tissue distribution and presence in human disease; (ii) Target Assessment exploiting the three‐dimensional structure of proteins for detailed binding site analysis, to estimate the drugability of the protein for small‐molecule inhibitor binding as well as selectivity profiles; and (iii) Target Validation providing evidence for a functional role in in vitro model systems, thus corroborating the biological hypothesis underlying the therapeutic concept. This rational approach has led to the discovery of drug targets for Lead Discovery, maximizing the likelihood for achieving target‐selective inhibition by small‐molecule inhibitors with minimal in vivo side effects and a therapeutic effect based on a sound biological hypothesis.
How users assess Web pages for information seeking
Authors: Tombros Anastasios , Ruthven Ian , Jose Joemon M. 
Published: December 2004

AbstractIn this article, we investigate the criteria used by online searchers when assessing the relevance of Web pages for information‐seeking tasks. Twenty‐four participants were given three tasks each, and they indicated the features of Web pages that they used when deciding about the usefulness of the pages in relation to the tasks. These tasks were presented within the context of a simulated work‐task situation. We investigated the relative utility of features identified by participants (Web page content, structure, and quality) and how the importance of these features is affected by the type of information‐seeking task performed and the stage of the search. The results of this study provide a set of criteria used by searchers to decide about the utility of Web pages for different types of tasks. Such criteria can have implications for the design of systems that use or recommend Web pages.
Static magnetic fields alter arteriolar tone in vivo
Authors: Morris Cassandra , Skalak Thomas 
Published: December 2004

AbstractThis study was designed to directly quantify the effect of localized static magnetic field (SMF) exposure on the diameter of microvessels in adult rat skeletal muscle in vivo. Microvascular networks in the exteriorized rat spinotrapezius microvasculature were exposed to a localized, uniform 70 mT SMF for 15 min. Arteriolar vessel diameters were measured; and the extent of vessel contraction, microvascular tone, was calculated before exposure, immediately after exposure, and 15 and 30 min after removal of the field. A calculated value of high tone corresponds to vessels that are vasoconstricted and a calculated value of low tone refers to vessels that are vasodilated. Vessels with initial tone <15% showed an increasing trend in tone and, conversely, vessels with initial tone >15% showed a significant (P < 0.05) decrease in tone 15 and 30 min following application, respectively. Further classification of the data with regards to the initial vessel diameter demonstrated that vessels with initial diameters <30 μm and initial tone <15%, smaller diameter vessels that are initially vasodilated, showed significant (P < 0.05) increase in tone immediately, 15 and 30 min following SMF exposure. Additionally, <30 μm vessels with >15% initial tone, smaller diameter vessels that are initially vasoconstricted, demonstrated a significant (P < 0.05) decrease in tone 30 min after SMF exposure. Vessels with initial diameters >30 μm had no significant response to the SMF. These results imply that SMF exposure influences arteriolar diameters, and therefore microvascular tone, in a restorative fashion acting to normalize the tone to the median tone value of 15% following exposure. Because this response occurs primarily in the resistance arterioles, which significantly influence tissue perfusion, SMF application could be efficacious for the treatment of both ischemic and edematous tissue disorders involving compromised microvascular function. Bioelectromagnetics 26:1–9, 2005. © 2004 Wiley‐Liss, Inc.
On the fundamental communication abstraction supplied by P2P overlay networks
Authors: Cramer Curt , Fuhrmann Thomas 
Published: December 2004

AbstractThe disruptive advent of peer‐to‐peer (P2P) file sharing in 2000 attracted significant interest. P2P networks have matured from their initial form, unstructured overlays, to structured overlays like distributed hash tables (DHTs), which are considered state‐of‐the‐art. There are huge efforts to improve their performance. Various P2P applications like distributed storage and application‐layer multicast were proposed.However, little effort was spent to understand the communication abstraction P2P overlays supply. Only when it is understood, the reach of P2P ideas will significantly broaden. Furthermore, this clarification reveals novel approaches and highlights future directions.In this paper, we reconsider well‐known P2P overlays, linking them to insights from distributed systems research. We conclude that the main communication abstraction is that of a virtual address space or application‐specific naming. On this basis, P2P systems build a functional layer implementing, for example lookup, indirection and distributed processing. Our insights led us to identify interesting and unexplored points in the design space. Copyright © 2004 AEI.
Increased expression of cystic fibrosis transmembrane conductance regulator in rat liver after common bile duct ligation
Authors: Shen Hong , Fan Yijun , Yang Xi , Burczynski Frank J. , Li Ping , Gong Yuewen 
Published: December 2004

AbstractLiver disease associated with cystic fibrosis (CF) has been increasingly diagnosed and recognized as one of the major causes of death in CF during recent years. The autosomal‐recessive disorder of CF results from mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) that encodes the CFTR protein. Due to its existence and multifunction in biliary epithelial, over‐ or less‐expression of CFTR in the liver may play an important role in the development of CF liver disease (CFLD). The aim of current study is to investigate the expression of CFTR in the liver of common bile duct ligated (BDL) rats. After BDL, there was an increase in the abundance of CFTR mRNA and protein. Immunohistochemical staining also demonstrated an increased intensity of CFTR staining in the liver tissue section. In conclusion, there is an increased expression of CFTR in the liver after common BDL. © 2004 Wiley‐Liss, Inc.
CD44 promotes resistance to apoptosis in murine colonic epithelium
Authors: Lakshman Minalini , Subramaniam Venkateswaran , Wong Sophie , Jothy Serge 
Published: December 2004

AbstractDysregulated expression of CD44 isoforms occurs consistently in colon carcinogenesis, and this change occurs also in most other types of cancer. One of the basic features of malignant transformation is the acquisition of resistance to apoptosis. We previously found that the colonic epithelium of mice, deficient in CD44 is predisposed to apoptosis. In this study, we asked whether the expression of CD44 alters the response of the colon to an apoptotic stimulus, and what are the mechanisms involved. For this, we assessed the susceptibility of the murine colon to apoptosis by total body irradiation to induce apoptosis. Apoptotic and concomitant changes relevant to the mechanisms of apoptosis were monitored by molecular markers of apoptosis. We found enhanced susceptibility to apoptosis in CD44 deficient colonic epithelium based on an increase in the number of apoptotic bodies, and activation of caspase 3. This was not associated with alterations in proliferations as shown by comparable Ki‐67 expression and BrdU labeling. Furthermore, upregulated active caspase 3 in CD44 deficient colon was accompanied by concomitant molecular alterations in caspase 9 and not caspase 8, and this indicated the involvement of the mitochondrial pathway in apoptosis execution. Overall, this is the first report demonstrating CD44 mediated resistance to apoptosis in the colonic epithelium in vivo. This implicates CD44 in promoting cell transformation into a malignant phenotype, in conjunction with other anti‐apoptotic factors. © 2004 Wiley‐Liss, Inc.
Induction of macrophage elastase (MMP‐12) gene expression by statins
Authors: Arikan Meltem C. , Shapiro Steven D. , Mariani Thomas J. 
Published: December 2004

AbstractThe statins (including mevastatin and lovastatin) are a widely prescribed class of serum‐cholesterol lowering drugs that function by inhibiting 3‐hydroxymethylglutaryl coenzyme A (HMG CoA) reductase activity and cellular sterol synthesis. Statins are also widely being appreciated for their inhibitory effects upon inflammation, primarily mediated through direct regulation of inflammatory gene expression. Here we report that statins are also capable of increasing the expression of macrophage elastase (MMP‐12). The induction of MMP‐12 in mouse macrophages by statins is specific for HMG CoA reductase inhibition, rescued by mevalonate and not observed after inhibition of subsequent steps in the cholesterol biosynthetic pathway. Modulation of cholesterol metabolism may lead to changes in MMP‐12 expression and subsequent impacts during physiological and pathophysiological states. We conclude that statins, in addition to their previously described anti‐inflammatory properties, may promote the production of some proteinases from activated macrophages. © 2004 Wiley‐Liss, Inc.
Differential effects of thyroid hormones on energy metabolism of rat slow‐ and fast‐twitch muscles
Authors: Bahi L. , Garnier A. , Fortin D. , Serrurier B. , Veksler V. , Bigard A.X. , Ventura‐Clapier R. 
Published: December 2004

AbstractThyroid hormone (TH) is an important regulator of mitochondrial content and activity. As mitochondrial content and properties differ depending on muscle‐type, we compared mitochondrial regulation and biogenesis by T3 in slow‐twitch oxidative (soleus) and fast‐twitch mixed muscle (plantaris). Male Wistar rats were treated for 21 to 27 days with T3 (200 μg/kg/day). Oxidative capacity, regulation of mitochondrial respiration by substrates and phosphate acceptors, and transcription factors were studied. In soleus, T3 treatment increased maximal oxygen consumption (Vmax) and the activities of citrate synthase (CS) and cytochrome oxidase (COX) by 100%, 45%, and 71%, respectively (P < 0.001), whereas in plantaris only Vmax increased, by 39% (P < 0.01). ADP‐independent respiration rate was increased in soleus muscle by 216% suggesting mitochondrial uncoupling. Mitochondrial substrate utilization in soleus was also influenced by T3, as were mitochondrial enzymes. Lactate dehydrogenase (LDH) activity was elevated in soleus and plantaris by 63% and 11%, respectively (P < 0.01), and soleus creatine kinase was increased by 48% (P < 0.001). T3 increased the mRNA content of the transcriptional co‐activator of mitochondrial genes, PGC‐1α, and the I and IV COX subunits in soleus. The muscle specific response to thyroid hormones could be explained by a lower content of TH receptors in plantaris than soleus. Moreover, TRα mRNA level decreased further after T3 treatment. These results demonstrate that TH has a major effect on mitochondrial content, regulation and coupling in slow oxidative muscle, but to a lesser extent in fast muscle, due to the high expression of TH receptors and PGC‐1α transcription factor. © 2004 Wiley‐Liss, Inc.
Computerized morphometry of the cirrhotic liver: Comparative analysis in primary biliary cirrhosis, alcoholic cirrhosis, and posthepatitic cirrhosis
Authors: Vertemati Maurizio , Minola Ernesto , Goffredi Maria , Sabatella Guido , Gambacorta Marcello , Vizzotto Laura 
Published: December 2004

AbstractFibrosis and nodular regeneration are the hallmarks of liver cirrhosis. To assess the degree of fibrosis and the severity of the structural changes affecting parenchymal and extraparenchymal components in liver cirrhosis, a computerized morphometric model has been applied to liver specimens from patients undergoing liver transplantation for primary biliary cirrhosis, posthepatitic and alcoholic cirrhosis. Fifty‐eight hepatectomy specimens from patients undergoing liver transplantation for cirrhosis were analyzed: 17 alcoholic, 28 posthepatitic (HBV‐related and HCV‐related cirrhosis), and 13 primary biliary cirrhoses. Liver specimens were fixed in 10% neutral‐buffered formalin and embedded in paraffin. Sections were stained with chromotrope‐aniline blue method and monoclonal antibodies against cytokeratin 7 and CD31. Volume fractions of parenchymal compartment and fibrosis were stereologically determined on the specimens stained with chromotrope‐aniline blue method. Volume fractions of portal bile ducts, proliferated bile ductules, and hepatocytes with biliary metaplasia were measured on cytokeratin 7 stains, while volume fractions of capillary units have been evaluated on CD31 staining. Volume fraction of fibrosis was higher in primary biliary cirrhosis than in the other disease‐induced cirrhosis. The main differences were related to immunohistochemical staining. Volume fraction of hepatocytes with biliary metaplasia was higher in HCV‐related cirrhosis, whereas volume fractions of biliary structures were more prominent in HBV‐related cirrhosis. Primary biliary cirrhosis was characterized by a reduced number of bile ducts and by a wider expression of cytokeratin 7 into periportal hepatocytes. Capillary units were more prominent in primary biliary cirrhosis than alcoholic and posthepatitic cirrhosis. Our computerized morphometric model well describes and quantifies the morphological alterations of the liver and it could represent an adjunctive tool to evaluate the degree of dysplastic phenomena involving parenchymal and extraparenchymal compartments. Microsc. Res. Tech. 65:113–121, 2004. © 2004 Wiley‐Liss, Inc.
Polymorphism of human papillomavirus type 31 isolates infecting the genital tract of HIV‐seropositive and HIV‐seronegative women at risk for HIV infection
Authors: Gagnon Simon , Hankins Catherine , Tremblay Cécile , Pourreaux Karina , Forest Pierre , Rouah Fabrice , Coutlée François 
Published: December 2004

AbstractThe genomic polymorphism of high‐risk human papillomavirus (HPV) for types other than 16 has not been extensively described. We describe here the genomic polymorphism of high‐risk HPV type 31 in 79 women (62 HIV‐seropositive, 17 HIV‐seronegative) by PCR‐sequencing of the long control region (LCR), E6 and E7. LCR polymorphism was generated by 25 (6.4%) single‐nucleotide variations over 391 bases. Each variant compared to the prototype contained from 2 to 13 variations (mean of 9.4 ± 3.3, median of 10). Considering the number of variation sites in each region of HPV genome, the LCR was more variable than E6 (13 over 496 nucleotide (nt), P = 0.03) and E7 (9 over 296 nt, P = 0.03). Non‐synonymous nucleotide variations were found in 31 (75.6%) of 41 isolates and were observed at six positions in E6. Each of the 8 HPV‐31 E7 variants contained from 2 to 5 mutations (mean of 4.29 ± 1.11, median of 5) compared to the prototype. Three non‐synonymous E6 and E7 variations were within cysteine arrays. The LCR prototype was significantly over‐represented in Caucasian women (14 (25%) of 56) compared to women of African descent (0 (0%) of 15 women, P = 0.03). Four (23.5%) of 17 women with persistent versus 6 (25.0%) of 24 women with transient infections were infected by the prototype (P = 1.00). HPV‐31 LCR was more polymorphic than oncogenes and was associated with ethnicity. J. Med. Virol. 75:213–221, 2005. © 2004 Wiley‐Liss, Inc.