bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study on the clinical and virological characteristics among patients with single occult hepatitis B virus (HBV), single occult hepatitis C virus (HCV) and occult HBV and HCV dual infection
Authors: Castillo Inmaculada , Rodríguez‐Iñigo Elena , López‐Alcorocho Juan Manuel , Bartolomé Javier , Pardo Margarita , Carreño Vicente 
Published: January 2007

AbstractOccult hepatitis B virus (HBV) and occult hepatitis C virus (HCV) infection are two recently described different forms of HBV and HCV infections. This work compares the clinical, virologic, and histologic characteristics of patients with occult dual infection to those of patients with single occult HBV or HCV infection. Seventy‐six patients with abnormal liver function tests of unknown etiology (serum HBsAg, anti‐HCV, HBV‐DNA, and HCV‐RNA negative) were included in the study. Viral genomes were tested in liver by real‐time PCR and confirmed by in situ hybridization. Of the 76 patients, 17 had occult HBV infection (intrahepatic HBV‐DNA positive, HCV‐RNA negative), 35 had occult HCV infection (intrahepatic HCV‐RNA positive, HBV‐DNA negative) and 24 occult dual infection (intrahepatic HCV‐RNA and HBV‐DNA). No differences among the three groups were found regarding clinical and epidemiologic data. The median load of intrahepatic genomic and antigenomic HCV‐RNA strands was similar between single occult HCV infection and occult HBV and HCV dual infection. The percentage of HCV‐infected hepatocytes did not differ between these groups. In occult single HBV infection, intrahepatic levels of HBV‐DNA and percentage of HBV‐infected hepatocytes were similar to the group of patients with occult dual infection. Finally, no differences were found in histological liver damage among the three groups. In conclusion, liver disease in patients with occult dual infection was not more severe than in patients with single occult HBV or occult HCV infection. Moreover, in occult dual infection there is no a reciprocal inhibition of the viral genomes. J. Med. Virol. 79:236–241, 2007. © 2007 Wiley‐Liss, Inc.
Relationship between mutations in HIV‐1 RNase H domain and nucleoside reverse transcriptase inhibitors resistance mutations in naïve and pre‐treated HIV infected patients
Authors: Roquebert Bénédicte , Wirden Marc , Simon Anne , Deval Jérome , Katlama Christine , Calvez Vincent , Marcelin Anne‐Geneviève 
Published: January 2007

AbstractRecent studies have highlighted the need of investigating the in vivo role of ribonuclease H (RNase H) in nucleoside reverse transcriptase inhibitors (NRTIs) resistance. The prevalence of RNase H mutations in naive and in NRTI pre‐treated patients in regimen failure were compared and some specific associations between NRTI resistance mutations and RNase H mutations were determined. Four positions were mutated more frequently in pre‐treated patients than in naive patients: L469T/I/M/H, T470P/S/E/K, A554T/L/K, and K558R/G/E. Mutations at position K558 were also associated with the number of thymidine analog mutations (TAMs). These results suggest that these mutations could play a role in NRTI resistance. J. Med. Virol. 79:207–211, 2007. © 2007 Wiley‐Liss, Inc.
Very low density lipoprotein and low density lipoprotein isolated from patients with hepatitis C infection induce altered cellular lipid metabolism
Authors: Napolitano Mariarosaria , Giuliani Alessandro , Alonzi Tonino , Mancone Carmine , D'Offizi Gianpiero , Tripodi Marco , Bravo Elena 
Published: January 2007

AbstractSeveral abnormalities of lipid metabolism, including hypo‐β‐lipoproteinemia and liver steatosis are associated with infection by hepatitis C virus (HCV). The aim of this study was to determine whether circulating lipoproteins of patients with HCV infection could directly cause alterations of lipid cellular metabolism. To this end the metabolic response of human monocyte‐derived macrophages (HMDM) to very low‐density lipoprotein (VLDL) and low‐density lipoprotein (LDL), measuring the cholesteryl ester (CE) and triglyceride (TG) production was analyzed. Lipoproteins were isolated from 18 patients infected with hepatitis C virus (HCV‐VLDL and HCV‐LDL) and from normal healthy donors (ct‐VLDL and ct‐LDL). In comparison to ct‐lipoproteins, HCV‐lipoproteins induced significant differences in HMDM CE and TG production. HCV‐VLDL decreased CE and TG production; while HCV‐LDL induced an increased TG synthesis. The present findings suggest that HCV infection modifies VLDL and LDL molecular composition, affecting cellular lipid metabolism, thus promoting intracellular lipid accumulation and hypo‐β‐lipoproteinemia. J. Med. Virol. 79:254–258, 2007. © 2007 Wiley‐Liss, Inc.
A framework for testing meso‐mediational relationships in Organizational Behavior
Authors: Mathieu John E. , Taylor Scott R. 
Published: January 2007

AbstractWe advance a framework for testing mediational relationships that traverse levels of analysis. We differentiate mediation that functions within levels, as well as different forms of meso‐mediation that operate downward across levels of analysis. We discuss the preconditions and evidential basis for these meso‐mediational type relationships. We then provide an empirical example that illustrates the different types of mediation and conclude with recommendations and extensions for studying more complex meso‐mediational organizational phenomena. Copyright © 2007 John Wiley & Sons, Ltd.
Amphiphilic Multi‐Arm Star‐Block Copolymers for Encapsulation of Fragrance Molecules
Authors: Ternat Céline , Kreutzer Georg , Plummer Christopher J. G. , Nguyen Tuan Q. , Herrmann Andreas , Ouali Lahoussine , Sommer Horst , Fieber Wolfgang , Velazco Maria Inés , Klok Harm‐Anton , Månson Jan‐Anders E. 
Published: January 2007

AbstractNovel amphiphilic multi‐arm star‐block copolymers with a hyperbranched core, a hydrophobic inner shell, and a hydrophilic outer shell have been prepared from a commercial hyperbranched polyester macroinitiator by ring‐opening polymerization of ε‐caprolactone, followed by atom transfer radical polymerization of tert‐butyl acrylate (tBuA). Hydrolysis of the tert‐butyl groups was then used to convert the poly(tBuA) blocks to poly(acrylic acid), resulting in stable amphiphilic core‐shell structures with significantly higher degrees of functionality than reported so far in the literature. A strong correlation between the maximum concentration of selected hydrophobic guest molecules and the concentration of amphiphilic star‐block copolymer in aqueous solution was observed by 1H NMR, demonstrating the capacity of these copolymers to encapsulate and disperse significant loadings (up to about 27 wt.‐%) of volatile hydrophobic molecules such as fragrances in water.magnified image
Ring‐Opening Homo‐ and Copolymerization of Cis/Trans‐3‐oxa‐4‐oxobicyclo‐ and Cis/Trans‐4‐oxa‐3‐oxobicyclo[5.4.0]undecane
Authors: Kerep Patrick , Ritter Helmut 
Published: January 2007

AbstractRing‐opening polymerization of the bicyclic lactone mixture 2, cis/trans‐3‐oxa‐4‐oxo‐ and cis/trans‐4‐oxa‐3‐oxobicyclo[5.4.0]undecane with Sn(Oct)2 as a catalyst was investigated for the first time (Scheme 1). The lactones were obtained by Baeyer–Villiger oxidation of cis/trans‐2‐decalone 1 (Scheme 2). Additionally, copolymerization of 2 with ε‐caprolactone in different ratios was performed. GPC measurements and 1H NMR spectroscopy proved that 2 was quantitatively incorporated into the polymer, leading to polycaprolactone with cyclohexane moieties in its backbone. $\overline M _{\rm n}$ values were up to 25 000 with $\overline M _{\rm w} /\overline M _{\rm n}$ ≤ 2.4. DSC measurements revealed a linear dependence of the melting points and the glass transition temperatures of the polymers on the feed of the bicyclic lactone 2. Additionally, the time dependence of the cis/trans ratio of the residual monomers was followed during the course of polymerization reaction by gas chromatography. The crystallinity of the resulting copolymers was investigated via polarization microscopy. Finally, it was shown that the mixture of 2 with ε‐caprolactone could be selectively polymerized with lipase. Only ε‐caprolactone was converted, while 2 remained unreacted in the residue.magnified image
On optimality of one‐bug‐look‐ahead policies for a software testing model
Authors: Jiang Xiaoyue , Du Donglei , Ray Thomas G. 
Published: January 2007

AbstractThe optimality of the One‐Bug‐Look‐Ahead (OLA) software release policy proposed by Morali and Soyer (Nav Res Logist 50 (2003), 88–104) is re‐examined in this paper. A counterexample is constructed to show that OLA is not optimal in general. The optimal stopping approach is then called upon to prove that OLA possesses weaker sense of optimality under conditional monotonicity and the strong sense of optimality holds under a more restrictive sample‐wise monotonicity condition. The NTDS data are analyzed for illustration, and OLA is shown to be robust with respect to model parameters. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007.
Modeling of a Pneumatic Hybrid Actuator using an Exponential Approach for Approximation of the Valve‐Actuator Behaviour
Authors: Dhanu Singh M. , Liem K. , Neumann R. , Kecskeméthy A. 
Published: January 2007

AbstractThe present paper describes a mathematical model for the control of a hybrid actuator consisting of a fluidic muscle and a linear pressure spring which is inflated by a proportional directional control valve in 3/3‐way function. The device is applied for physical simulation of arbitrary force/displacement relationships.The mathematical model of the system fluidic muscle/valve consists of the approximation of the pressure time‐history by an exponential function. The coefficients of the exponential function are identified from corresponding measurement and Least Squares minimization. The advantages of this approximation are that the differential equation for the pressure becomes simple and the computations more efficient. This makes the approach suitable for model‐based control. The paper shows that with the proposed model sufficient accuracy can be achieved such as to have a good mathematical model for feedback linearization. For later use the device can be employed in fields of biomechanics as well as in general environments such as motion simulations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular transport of aromatic hydrocarbons through lignin‐filled natural rubber composites
Authors: Mathew Thomas V. , Kuriakose Sunny 
Published: January 2007

AbstractThe diffusion and transport of organic solvents through lignin‐filled natural rubber composites have been studied in the temperature range 25–45°C. The diffusion of aromatic solvents through these samples were studied with special reference to the effect of filler concentration, penetrant size, and temperature. Transport coefficients such as diffusion, permeation, and sorption coefficients were estimated. The van't Hoff relationship was used to determine the thermodynamic parameters. The first order kinetic rate constant has been evaluated. A correlation between theoretical and experimental sorption results was evaluated. POLYM. COMPOS., 28:15–22, 2007. © 2007 Society of Plastics Engineers
Spirometric pulmonary function in 3‐ to 5‐year‐old children
Authors: Pesant Caroline , Santschi Miriam , Praud Jean‐Paul , Geoffroy Mario , Niyonsenga Théophile , Vlachos‐Mayer Helen 
Published: January 2007

AbstractForced expiratory maneuvers are routinely used in children, 6 years of age and older for the diagnosis and follow‐up of respiratory diseases. Our objective was to establish normative data for an extensive number of parameters measured during forced spirometry in healthy 3‐ to 5‐year‐old children. Children aged between 3 and 5 years were tested in 11 daycare centers. Usual parameters, including FEV1, FVC, PEF, FEF25–75, FEF25, FEF50, FEF75, and Aex were measured and analyzed in relation to sex, age, height, and weight. In addition, the same analysis was performed for FEV0.5 and FEV0.75. One hundred sixty‐four children were recruited for testing including 87 girls and 77 boys. Thirty‐five were 3 years old, 63 were 4 years old, and 66 were 5 years old. Overall, 143 children (87%) accepted to perform the test and 128 children (78%) were able to perform at least two technically acceptable expiratory maneuvers. Analyses using different regression models showed that height was the best predictor for every parameter. In conclusion, the present study confirms that most healthy 3–5 years old children can perform valid forced expiratory maneuvers. In agreement with other studies, we found that height is the most important single predictor of various parameters measured on forced spirometry. The present study is the first to establish normative values for FEV0.75, as well as to demonstrate that Aex can be easily performed in the majority of children aged 3–5 years. These are likely important parameters of lung function in this age range. Pediatr Pulmonol. 2007; 42:263–271. © 2007 Wiley‐Liss, Inc.
Antimicrobial activity and chemical composition of essential oil from Hedychium coronarium
Authors: Joy Beena , Rajan Akhila , Abraham Emilia 
Published: January 2007

AbstractThe essential oil from fresh and dried rhizomes of Hedychium coronarium on GC‐MS analysis resulted in the identification of 44 and 38 constituents representing 93.91% and 95.41%, respectively. The major components of the essential oil from fresh and dried Hedychium coronarium rhizome were 1,8‐cineole (41.42%, 37.44%), β‐pinene (10.39%, 17.4%) and α‐terpineol (8.8%, 6.7%). The aromatic oil has antifungal as well as antibacterial effects. The antimicrobial activities of the essential oil were individually evaluated against four microorganisms, including two bacteria and two fungi. It was found that the antimicrobial activity was higher in the fresh sample than the dried. Both samples showed a better activity against Trichoderma sp. and Candida albicans than against the bacteria Bacillus subtilis and Pseudomonas aeruginosa. Copyright © 2007 John Wiley & Sons, Ltd.
Improving robot navigation through self‐supervised online learning
Authors: Sofman Boris , Lin Ellie , Bagnell J. Andrew , Cole John , Vandapel Nicolas , Stentz Anthony 
Published: January 2007

AbstractIn mobile robotics, there are often features that, while potentially powerful for improving navigation, prove difficult to profit from as they generalize poorly to novel situations. Overhead imagery data, for instance, have the potential to greatly enhance autonomous robot navigation in complex outdoor environments. In practice, reliable and effective automated interpretation of imagery from diverse terrain, environmental conditions, and sensor varieties proves challenging. Similarly, fixed techniques that successfully interpret on‐board sensor data across many environments begin to fail past short ranges as the density and accuracy necessary for such computation quickly degrade and features that are able to be computed from distant data are very domain specific. We introduce an online, probabilistic model to effectively learn to use these scope‐limited features by leveraging other features that, while perhaps otherwise more limited, generalize reliably. We apply our approach to provide an efficient, self‐supervised learning method that accurately predicts traversal costs over large areas from overhead data. We present results from field testing on‐board a robot operating over large distances in various off‐road environments. Additionally, we show how our algorithm can be used offline with overhead data to produce a priori traversal cost maps and detect misalignments between overhead data and estimated vehicle positions. This approach can significantly improve the versatility of many unmanned ground vehicles by allowing them to traverse highly varied terrains with increased performance. © 2007 Wiley Periodicals, Inc.
Field penetration into amorphous‐carbon films: consequences for field‐induced electron emission
Authors: Forbes Richard G. , Xanthakis J. P. 
Published: January 2007

AbstractThe phenomenon of low‐macroscopic‐field (LMF) electron emission is sometimes exhibited by thin films of non‐metallic materials. Both wide‐band‐gap semiconductors and hopping conductors such as amorphous carbon exhibit this phenomenon, and its origin has been under discussion for some years. This paper first uses a simple theory to discuss field penetration into hopping conductors with a high density of localised states near the charge‐neutrality level. This theory is physically similar to widely used existing theories, in that it assumes continuous charge distributions and uses the one‐dimensional Poisson's equation. The theory suggests that little field penetration occurs, and that models of LMF emission based on uniform barrier lowering are not viable. Unexpected self‐consistency difficulties are also created for some types of local‐field‐enhancement model. A re‐assessment of the validity of this simple field‐penetration theory suggests the following. Contrary to a basic assumption of this type of theory, the granularity of the screening charge distribution is a dominant feature of the physics associated with LMF emission from nanoscale‐sized emission sites on thin films of hopping conductors. The authors think that the screening is carried out by discrete charges in localised states, although details are not clear. This conclusion is potentially very far‐reaching. In particular, new forms of field‐penetration theory may be required before definitive decisions can be made about the self‐consistency of some models of local field enhancement. Copyright © 2007 John Wiley & Sons, Ltd.
Automobile exhaust catalysis at the atomic scale: atom‐probe investigations on platinum alloys
Authors: Bagot P. A. J. , Cerezo A. , Smith G. D. W. , de Bocarmé T. Visart , Godfrey T. J. 
Published: January 2007

AbstractA dedicated three‐dimensional atom‐probe has been fitted with anin situhigh pressure/temperature reaction cell. This was used for studying the interaction of gases with Pt‐alloy surfaces typical of those employed in automotive exhaust catalysis. The reactions of nitric oxide (NO) and oxygen (O2) on Pt and Pt–17.4 at.% Rh FIM specimens were explored, revealing a range of surface restructuring and segregation effects, which depend sensitively on catalyst composition, orientation, temperature and gas chemistry. Specifically, we observed that exposure of Pt–Rh to either NO or O2at 422–473 K and 10 mbar induced Rh surface segregation uniformly over the surface. However, on raising the temperature to 573 K or higher, the Pt–Rh{111} surface remained Rh‐enriched but the Pt–Rh{001} surface became severely Rh‐depleted. We attribute this observation to the possible diffusion of Rh species across the specimen apex, indicating that segregation occurs in directions both normal and parallel to the surface in Pt–Rh catalysts. Copyright © 2007 John Wiley & Sons, Ltd.
Aspects of the observation of clusters in the 3‐dimensional atom probe
Authors: Cerezo A. , Davin L. 
Published: January 2007

AbstractThe maximum separation method is a useful technique for the identification of solute clusters within 3‐dimensional atom probe (3DAP) data. However, the method requires the selection of appropriate parameters that will correctly identify solute clusters without incorrectly identifying random variation in solute atom separations as being due to cluster formation. A simple analytical approach has been used to estimate the apparent number of clusters that would be expected using the maximum separation method in a random solute distribution of a given overall composition. Results of the analytical model have been found to give a good match with tests where the maximum separation method has been applied to randomised experimental 3DAP data. The model allows calculation of suitable parameters for accurate identification of clusters under a range of different conditions. A Poisson probability distribution has been used to formalise the errors involved in the measurement of the number densities of clusters or precipitates within 3DAP data. This approach also allows an upper limit for the precipitate density to be defined in cases where no precipitates are observed within a volume of analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Thermal reaction and stability of NiFe/Cu thin films investigated by atom probe tomography
Authors: Ene C. B. , Schmitz G. , Kirchheim R. , Hütten A. 
Published: January 2007

AbstractNiFe/Cu multilayer stacks of 2 nm single layer thickness were deposited onto needle‐shaped W tips by ion beam sputtering and analysed by atom probe tomography (TAP) after appropriate heat treatments. After annealing at 250 °C for 30 min, no significant structural or chemical transformation of the initial layer system is detected, although such a heat treatment appreciably reduces the magneto resistivity. A slight decrease of the concentration slope at the interfaces is attributed to a very short‐range interdiffusion. Clear grain boundary diffusion is observed after annealing at 400 °C for 30 min. Further annealing at 500 °C for 20 min and 40 min still preserves the layered structure with a homogeneous solution of Ni inside the Cu layers of up to 25 at.% Ni. Copyright © 2007 John Wiley & Sons, Ltd.
The process of software maintenance: a comparison of object‐oriented and third‐generation development languages
Authors: Eierman Michael A. , Dishaw Mark T. 
Published: January 2007

AbstractWe suggest that there is a lack of empirical evidence for claims that object‐oriented software has an advantage in terms of software maintenance. We use a model of software maintenance that suggests that the maintenance task and programming language have an impact on the maintenance process and, in turn, use the maintenance process to explore the impact of the programming language on the maintenance process. A field study design, using students, examined the perceived difference in process employed by students using an object‐oriented language and those using a third‐generation language. We found a difference in the perceived process used by the two groups of students. Students using the object‐oriented language perceived that they performed more planning and diagnosis activities during the maintenance process and students using a third‐generation language perceived that they performed more knowledge building activities. Copyright © 2007 John Wiley & Sons, Ltd.
Review of content‐aware resource allocation schemes for video streaming over wireless networks
Authors: Pahalawatta Peshala V. , Katsaggelos Aggelos K. 
Published: January 2007

AbstractAs wireless technology evolves towards its fourth generation (4G) of development, the prospect of offering multimedia services such as on‐demand video streaming and video conferencing to wireless mobile clients becomes increasingly more viable. The eventual success of such applications depends on the efficient management of the limited system resources while taking into account the time‐varying wireless channel conditions as well as the varying multimedia source content. In this paper, we review some of the recent advances in cross‐layer design schemes, which aim at providing significant gains in performance for video streaming systems through content‐aware resource allocation. Advances in both, real‐time video streaming, where the video is encoded and transmitted in real‐time, as well as, on‐demand video streaming, where the video is pre‐encoded in a media server, are considered. Copyright © 2007 John Wiley & Sons, Ltd.