bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prevalence of HBV genotypes in Central and Eastern Europe
Authors: Deterding Katja , Constantinescu Ileana , Nedelcu Filofteia Daniela , Gervain Judit , Nĕmeček Vratislav , Srtunecky Otakar , Vince Adriana , Grgurevic Ivica , Bielawski Krzysztof P. , Zalewska Małgorzata , Bock Thomas , Ambrozaitis Arvydas , Stanczak Janusz , Takács Mária , Chulanov Vladimir , Slusarczyk Janusz , Dražd'áková Marcela , Wiegand Johannes , Cornberg Markus , Manns Michael P. , Wedemeyer Heiner 
Published: August 2008

AbstractThe importance of hepatitis B virus (HBV) genotypes for disease progression and response to interferon‐alpha‐based treatment is well established. While almost all patients in the Mediterranean area are infected with HBV genotype D, HBV genotype A is dominant in Northern Europe. However, the distribution of HBV genotypes is unknown for several Central and Eastern European countries. Data are described of 1313 HBsAg‐positive patients recruited at 14 referral centers in eight countries. There were only very few cases of HBV genotype B, C, E, F, and H infection while HBV genotypes A and D were found in 42% and 48% of patients, respectively. Eight percent of patients had positive bands for more than one genotype using the hybridization assay. The frequency of genotype A was higher in Poland (77%) and the Czech Republic (67%) as compared to Hungary (47%), Lithuania (41%), Croatia (8%), and Germany (32%). In contrast, HBV genotype D was most frequent in Croatian, Romanian, and Russian patients with 80%, 67%, and 93% of cases, respectively. In conclusion, HBV genotype A versus D showed significantly different distribution patterns in Central and Eastern Europe which deserves consideration for national guidelines and treatment decisions. J. Med. Virol. 80:1707–1711, 2008. © 2008 Wiley‐Liss, Inc.
Identification and in vitro characterisation of Lactobacillus plantarum strains from artisanal Bulgarian white brined cheeses
Authors: Georgieva Ralitsa N. , Iliev Ilia N. , Chipeva Valentina A. , Dimitonova Silvia P. , Samelis John , Danova Svetla T. 
Published: August 2008

AbstractLactobacillus plantarum strains were isolated from fully ripened, white brined Bulgarian home‐made cheeses. Strains were derived from phenotypically homogenous Lactobacillus group and were identified as L. plantarum based on both phenotypic and molecular identification (species‐specific and multiplex PCR) methods. Heterogeneity of L. plantarum isolates was evaluated by Rep‐PCR analysis.Further antimicrobial activity, antibiotic susceptibility and transit tolerance of the strains were evaluated. Most of them showed broad spectrum of activity against Gram‐negative bacteria (including human pathogens) independent on the presence of organic acids or hydrogen peroxide.All strains were sensitive to amoxicillin and sulfamethoxazole/trimethoprim, resistant to clinically relevant β ‐lactame antibiotics (penicillin and ampicillin) and to nalidixic acid, ciprofloxacin, streptomycin, and vancomycin. Significant variability in the sensitivity to tetracycline was noted.The tolerance to low pH, bile salts, pepsin and pancreatin at concentrations similar to those in the gastrointestinal tract was strain‐dependent. The exposure to bile salts was less destructive than exposure to pH 2.0 for all tested strains. Based on their combined responses to the above selection criteria, four L. plantarum strains, RL29, RL34, RL36 and RL37, were selected as potential probiotics for in vivo studies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efflux genes and active efflux activity detection in Malaysian clinical isolates of methicillin‐resistant Staphylococcus aureus (MRSA)
Authors: Saiful Azmi Johari , Mastura Mohtar , Zarizal Suhaili , Mazurah Mohamed Isa , Shuhaimi Mustafa , Ali Abdul Manaf 
Published: August 2008

AbstractEfflux‐mediated resistance has been recognized as an important contributor of antibiotic resistance in bacteria, especially in methicillin‐resistant Staphylococcus aureus (MRSA) isolates. This study was carried out to detect and analyze efflux genes (norA and mdeA) and active efflux activity in a collection of Malaysian MRSA and methicillin‐sensitive S. aureus (MSSA) clinical isolates. Nineteen isolates including three ATCC S. aureus reference strains were subjected to PCR detection and DNA sequence analysis for norA and mdeA and active efflux detection using modified minimum inhibitory concentration (MIC) assay. From the 19 isolates, 18 isolates harboured the mdeA gene while 16 isolates contained norA gene. DNA sequence analysis reveals 98–100% correlation between the PCR product and the published DNA sequences in GenBank. In addition, 16 isolates exhibited active efflux activity using the ethidium bromide (EtBr)‐reserpine combination MIC assay. To our knowledge, this is the first report on the detection of efflux genes and active efflux activity amongst Malaysian clinical isolates of MRSA/MSSA. Detection of active efflux activity may explain the previous report on efflux‐mediated drug resistance profile amongst the local clinical isolates. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In vitro antifungal activity and mechanism of action of chitinase against four plant pathogenic fungi
Authors: Yan RuiXiang , Hou JianHua , Ding DongFeng , Guan WenQqiang , Wang CuiYan , Wu ZhiQiang , Li MingGang 
Published: August 2008

AbstractTo determine why chitinase has different antifungal activity on different pathogenic fungi in vitro, we purified recombinant rice chitinase from Pichia pastoris and investigated its antifungal activity against four fungi – Rhizopus stolonifer (Ehrenb. et Fr.) Vuill, Botrytis squamosa Walker, Pythium aphanidermatum (eds.) Fitzp, and Aspergillus niger van Tiegh. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the surface microstructure and proportion of chitin in the cell wall of the four fungi, respectively. The results showed that the chitinase exhibited different antifungal activities against the four fungi, which was directly correlated to the surface microstructure and the proportion of chitin in the fungal cell wall. It will help understanding the antifungal mechanism of the recombinant chitinase and further determining its application scope on crop protection and post‐harvest storage of fruits and vegetables. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inducible nature of the enzymes involved in catabolism of caffeine and related methylxanthines
Authors: Dash Swati Sucharita , Gummadi Sathyanarayana N. 
Published: August 2008

AbstractPreviously isolated strain of Pseudomonas sp. has the capability of utilizing caffeine as the sole source of carbon and nitrogen and degrading caffeine at higher concentrations (>10 g l–1). In this study, an assay has been developed to study the enzymatic conversion of caffeine to subsequent methylxanthines by cell free extracts of Pseudomonas sp., the activity of which has been stabilized by use of stabilizers in the lysis buffer. Growth of the strain in various methylxanthines and later enzyme assay demonstrated that the enzyme(s) involved in degradation of caffeine and other methylxanthines were inducible in nature. The results also indicated that more than one enzyme are involved in degradation of caffeine to xanthine, which constitute the primary steps in bacterial caffeine catabolism. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metabolic adaptation and oxaloacetate homeostasis in P. fluorescens exposed to aluminum toxicity
Authors: Lemire Joseph , Kumar Puja , Mailloux Ryan , Cossar Kathyrn , Appanna Vasu D. 
Published: August 2008

AbstractMicrobial systems are known to elaborate intricate metabolic strategies in an effort to fend the toxic impact of numerous metals. In this study, we show that the exposure of Pseudomonas fluorescens to aluminum (Al) resulted in a metabolic shift aimed at diverting oxaloacetate towards the biogenesis of an aluminophore. This metabolic alteration was characterized by uncoupling of two gluconeogenic enzymes, namely pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK). While PC displayed a sharp increase in activity and expression, PEPCK was severely diminished. Malic enzyme (ME) and NAD kinase (NADK), two enzymes involved in maintaining a reductive environment, were markedly increased in the Al‐stressed cells. Hence, Al‐exposed Pseudomonas fluorescens evoked a metabolic response aimed at generating oxaloacetate and promoting an intracellular reductive environment. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Direct detection of Kitasatospora species with a chaperone oligonucleotide microarray method lacking PCR amplification
Authors: Guenther Sebastian , Groth Ingrid , Schierack Peter , Grabley Susanne , Munder Thomas 
Published: August 2008

AbstractIdentification of members of the genus Kitasatospora from soil samples has been introduced to evaluate occurrence of potential natural compound producers in different habitats. The microarray hybridization usually involves PCR amplification of the target DNA. Since PCR might lead to biased amplification, a diagnostic Kitasatospora microarray technique was improved by a protocol lacking PCR amplification prior to hybridization. The described advanced hybridization method used chaperone oligonucleotides for direct co‐hybridization with genomic DNA on an oligonuclotide microarray with optical readout. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
HIV entry inhibitors and their potential in HIV therapy
Authors: Qian Keduo , Morris‐Natschke Susan L. , Lee Kuo‐Hsiung 
Published: August 2008

AbstractThis review discusses recent progress in the development of anti‐HIV agents targeting the viral entry process. The three main classes (attachment inhibitors, co‐receptor binding inhibitors, and fusion inhibitors) are further broken down by specific mechanism of action and structure. Many of these inhibitors are in advanced clinical trials, including the HIV maturation inhibitor bevirimat, from the authors' laboratories. In addition, the CCR5 inhibitor maraviroc has recently been FDA‐approved. Possible roles for these agents in anti‐HIV therapy, including treatment of virus resistant to current drugs, are also discussed. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 2, 369–393, 2009
Heteronuclear dipolar decoupling effects on multiple‐quantum and satellite‐transition magic‐angle spinning NMR spectra
Authors: Ganapathy S. , Delevoye L. , Amoureux J. P. , Madhu P. K. 
Published: August 2008

AbstractWe here report on the influence of heteronuclear dipolar decoupling on the 27Al 3QMAS, 5QMAS, and the double‐quantum filter–satellite‐transition magic‐angle spinning (DQF‐STMAS) spectra of a strongly dipolar‐coupled system, gibbsite. The requirements for heteronuclear dipolar decoupling increase with the order of coherence evolving in the indirect dimension of a two‐dimensional (2D) experiment. The isotropic line width of the high‐resolution 2D spectra, in samples like gibbsite, is composed of four parts: the distribution of isotropic shifts (δISO, δQIS), the homogeneous broadening related to the proton–proton flip‐flop terms, the 27Al27Al homonulcear dipolar couplings, and the 1H27Al heteronuclear dipolar couplings. It is shown that, even in the case of gibbsite, where a strong proton–proton bath exists, the main resolution limiting factor in these experiments resides in the 1H27Al dipolar interaction. Copyright © 2008 John Wiley & Sons, Ltd.
DFT/NMR integrated approach: a valid support to the total synthesis of chiral molecules
Authors: Chini Maria Giovanna , Riccio Raffaele , Bifulco Giuseppe 
Published: August 2008

AbstractThe analysis of the configuration of kedarcidin chromophore and palau'amine through quantum chemical calculation of Js and chemical shifts suggests a fast and convenient quantum chemical approach that can be applied prior to proceeding to the total synthesis of complex natural compounds in order to avoid loss of time and resources employed in the total synthesis of wrong diastereoisomers. Copyright © 2008 John Wiley & Sons, Ltd.
Deposition of Barrier Coatings from Vinyltrimethylsilane‐Fed Glow Discharges
Authors: Francescangeli Adriano , Palumbo Fabio , d'Agostino Riccardo 
Published: August 2008

AbstractRadio‐frequency glow discharges fed with vinyltrimethylsilane have been studied for the deposition of barrier coatings onto polymer substrates as single or multiple layers. The deposition process has been investigated considering both the chemistry of the coatings and the spectroscopic analysis of the gas phase. It has been shown that RF power and oxygen addition allow one to switch from organosilane films to silica‐like inorganic, dense, barrier films. A deposition mechanism is suggested for the interpretation of the deposition kinetics. Furthermore, it has been shown that vinyltrimethylsilane can be conveniently exploited as single monomer for the deposition of organic/inorganic multistacks with high barrier performances.magnified image
Superionic transition of the NaI–AgI system
Authors: Lozano Z. C. A. , Correa H. , Lara D. Peña , Vargas R. A. 
Published: August 2008

AbstractThe solid electrolyte transition in NaI–AgI was studied by electrical conductivity measurements in the temperature range between 323 K and 523 K. Although NaI does not dissolve in AgI, the addition of NaI led to a stable α–β‐phase boundary of AgI at 420 K, decreased the total ionic conductivity in the α‐phase and caused a smaller step change of conductivity between the values above (α‐phase) and below (β‐phase) 420 K. The conductivity data were analyzed by considering that the ionic carrier density is the main source of the sudden increase in the ionic conductivity through this solid electrolyte transition; therefore, we propose a modified version of the Welch–Dienes trial model free energy density in which the quadratic terms for energy are conserved. In this model three terms were considered: the first one associated with the activation energy (Ui) to promote an atom toward an interstitial site; the second one associated with the attractive interaction due to the Frenkel pair (U) and the last one due to the configurational entropy. It was found that the observed step change in conductivity is mainly due to the carrier density ni The trial free energy function admits at least three solutions for given parameter values, but the equilibrium configuration is that in which ni = $ \bar n $i gives the minimum value at a given temperature. In this way, we were able to reproduce the conductivity changes observed in the NaI–AgI system at 420 K. The phase transition is expected to be first order because the order parameter (n) changes abruptly. The activation energy Ui associated with this anomaly was of the order of 0.3 eV, and the best fitting parameters were Γ = 2.81, x = 0.77 and γ = 5.49. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitonic imaging spectroscopy of single‐walled carbon nanotubes
Authors: Lefebvre Jacques , Austing David G. , Finnie Paul 
Published: August 2008

AbstractWe show how photoluminescence (PL) imaging can be used to gain fundamental spectroscopic information on the optical excitations in single‐walled carbon nanotubes (SWNTs). Individual SWNTs are identified, and emission and excitation (PLE) spectra are obtained. In addition to the dominant E11 and E22 transitions, we observe several resonances including the transverse E12 exciton, and up to three excited excitonic bands. The (n,m) family dependence is obtained for some 25 species in the 1.1 to 1.6 µm emission range. We provide simple power series expansion to facilitate (n,m) assignment of all these peaks. This paper complements recently published work. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carbon nanotubes for interconnects in VLSI integrated circuits
Authors: Robertson J. , Zhong G. , Telg H. , Thomsen C. , Warner J. M. , Briggs G. A. D. , Detlaff U. , Roth S. , Dijon J. 
Published: August 2008

AbstractThe paper reviews the requirements for carbon nanotubes to be used as interconnects in VLSI integrated circuits. It describes the production by chemical vapour deposition of high density arrays of nanotubes suitable for use as interconnects, and describes their characterisation by Raman and transmission electron microscopy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improving separation techniques for single‐walled carbon nanotubes: Towards monodisperse samples
Authors: Hennrich F. , Lebedkin S. , Kappes Manfred M. 
Published: August 2008

AbstractWe describe novel procedures which allow the facile production of monochiral single wall carbon nanotube suspensions using either density gradient centrifugation or selective dispersion with special organic polymers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of carbon nanotubes as horizontal interconnects
Authors: Zhang Can , Cott Daire , Chiodarelli Nicolo , Vereecken Philippe , Robertson John , Whelan Caroline M. 
Published: August 2008

AbstractIn this study, we evaluate the possibility of achieving horizontal carbon nanotube (CNT) growth for application as global interconnects in VLSI integrated circuits. A test structure suitable for electrical characterization has been designed and fabricated to assess horizontal CNT growth. Catalyst placement on the vertical electrode surface was realized by either physical vapour deposition or electroless deposition of Ni. The resulting yield of nanotubes grown by a chemical vapour deposition method is found to be low and randomly oriented, most likely due to low density of the catalyst particles deposited on the HGTS. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Infrared microreflectance study of the pressure effect on the structural properties of magnetically aligned single‐wall carbon nanotubes
Authors: Kuntscher C. A. , Thirunavukkuarasu K. , Kamarás K. , Simon F. , Walters D. A. 
Published: August 2008

AbstractThe optical response of magnetically aligned singlewall carbon nanotube films was studied by polarizationdependent reflectance measurements in the infrared and visible frequency range as a function of external pressure. At ambient pressure the optical properties are anisotropic and show the characteristic excitations (broad infrared peak and optical transitions).The pressure‐induced shift of the optical transitions reveals an anomaly at a critical pressure Pc≈2.7 GPa. This anomaly can be attributed to the circular‐to‐oval structural phase transition in the nanotubes. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inkjet printed resistive and chemical‐FET carbon nanotube gas sensors
Authors: Mäklin Jani , Mustonen Tero , Halonen Niina , Tóth Géza , Kordás Krisztián , Vähäkangas Jouko , Moilanen Hannu , Kukovecz Ákos , Kónya Zoltán , Haspel Henrik , Gingl Zoltán , Heszler Péter , Vajtai Robert , Ajayan Pulickel M. 
Published: August 2008

AbstractAqueous solutions of carboxyl functionalized single‐wall carbon nanotube (SWCNT) films are deposited on silicon chips by the inkjet printing technique. By varying the film thickness it is possible to obtain low‐ or high density networks of SWCNTs, having either nonlinear or linear current‐voltage characteristics, respectively. The electrical transport in the low‐density films is gate‐controllable and utilized as chemical field‐effect transistor sensors; whereas the high‐density SWCNT networks of nearly Ohmic behaviour are used as conventional resistive gas sensors. The response of both types of sensors is studied for hydrogen sulfide (H2S) analyte. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectrophoretically assembled carbon nanotube‐metal hybrid structures with reduced contact resistance
Authors: Ranjan Nitesh , Mertig Michael 
Published: August 2008

AbstractWe report the bottom‐up assembly of single‐walled carbon nanotube interconnects between micro‐fabricated gold electrodes by dielectrophoresis followed by a post‐dielectrophoretic deposition of metal from an aqueous Pd salt solution. The dielectrophoretic metal deposition along interconnects takes preferentially place at sites where high contact resistances occur. These create sufficiently high voltage drops, and thus, large field gradients which lead to a local deposition of met al. Since in turn the metal deposition leads to a reduction of the local resistances, the reported post‐treatment process is self‐regulating, that is, the deposition of metal stops when the contact resistances become sufficiently reduced. Applying this process to single interconnects of carbon nanotubes a reduction of the overall resistance below 1 MΩ has been achieved. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New phase of polymeric C60: double chains via [2+2] cycloaddition
Authors: Artyukhov Vasilii I. , Belova Elena E. , Chernozatonskii Leonid A. 
Published: August 2008

AbstractWe investigate the structure of a new phase of one‐dimensional polymeric C60 that has recently been demonstrated to form from the orthorhombic phase of polymeric C60 as a result of pressure‐driven photopolymerization, using ab initio calculations at the density‐functional theory level. The transition to the new phase proceeds via formation of additional [2+2] bonds between neighbouring C60 chains of the O phase, resulting in double chains of C60 units along the [100] crystallographic direction. The new phase is a semiconductor, like the original O phase, but with a narrower band gap. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gas chromatography/time‐of‐flight mass spectrometry based metabonomic approach to differentiating hypertension‐ and age‐related metabolic variation in spontaneously hypertensive rats
Authors: Lu Yihong , A Jiye , Wang Guangji , Hao Haiping , Huang Qing , Yan Bei , Zha Weibin , Gu Shenghua , Ren Hongcan , Zhang Ying , Fan Xialei , Zhang Mei , Hao Kun 
Published: August 2008

AbstractMetabonomics is a systematic approach to the study of in vivo metabolic profiles and therefore allows deep insight into and a better understanding of the pathogenesis of disease. To characterize the development of hypertension, a hypertensive animal model, the spontaneously hypertensive rat (SHR), and its normotensive control, the Wistar Kyoto (WKY) rat, were investigated and their blood plasma analyzed using the high‐throughput metabolomic tool, gas chromatography/time‐of‐flight mass spectrometry (GC/TOFMS). A total of 187 peaks were quantitatively determined after deconvolution, and 78 of them were identified. Principal components analysis (PCA) and projection to latent structure partial least‐squares discriminant analysis (PLS‐DA) were used to process the GC/TOFMS data. The resulting mathematical models were further validated by cross‐validation. Plasma compositional differences of many identified compounds showed hypertension‐related variation between SHR and WKY rats, and age‐related changes from 10 to 18 weeks for both the SHR and WKY rats. These compositional changes involved compounds such as hexadecanoic acid, linoleic acid, oleic acid, stearic acid, 3‐hydroxybutyric acid, citric acid, threonic acid, tyrosine, tryptophan, threonine, phenylalanine, serine, ornithine, methionine, 3‐hydroxyproline, creatinine, erythrose, myo‐inositol, D‐methylglucopyranoside, tocopherol, sitosterol, and nonesterified cholesterol. Significantly elevated free fatty acids (FFA) were observed in SHR relative to those in WKY rats, and their levels increased as the SHR aged from 10 to 18 weeks. The close correlation between FFA and hypertension suggests that FFA are potential biomarker candidates for hypertension and they may play an important role in the development of hypertension in SHR. It is also indicated that GC/TOFMS‐based metabonomics is a powerful approach to identifying potential biomarkers and investigating the pathological processes of hypertension and the physiological developments of aging. Copyright © 2008 John Wiley & Sons, Ltd.