bluuebunny/crossref_metadata_2025 huggingface dataset:
The crystal structure of phenylpyruvate decarboxylase from Azospirillum brasilense at 1.5 Å resolution
Authors: Versées Wim , Spaepen Stijn , Vanderleyden Jos , Steyaert Jan
Published: March 2007

Phenylpyruvate decarboxylase (PPDC) of Azospirillum brasilense, involved in the biosynthesis of the plant hormone indole‐3‐acetic acid and the antimicrobial compound phenylacetic acid, is a thiamine diphosphate‐dependent enzyme that catalyses the nonoxidative decarboxylation of indole‐ and phenylpyruvate. Analogous to yeast pyruvate decarboxylases, PPDC is subject to allosteric substrate activation, showing sigmoidal v versus [S] plots. The present paper reports the crystal structure of this enzyme determined at 1.5 Å resolution. The subunit architecture of PPDC is characteristic for other members of the pyruvate oxidase family, with each subunit consisting of three domains with an open α/β topology. An active site loop, bearing the catalytic residues His112 and His113, could not be modelled due to flexibility. The biological tetramer is best described as an asymmetric dimer of dimers. A cysteine residue that has been suggested as the site for regulatory substrate binding in yeast pyruvate decarboxylase is not conserved, requiring a different mechanism for allosteric substrate activation in PPDC. Only minor changes occur in the interactions with the cofactors, thiamine diphosphate and Mg2+, compared to pyruvate decarboxylase. A greater diversity is observed in the substrate binding pocket accounting for the difference in substrate specificity. Moreover, a catalytically important glutamate residue conserved in nearly all decarboxylases is replaced by a leucine in PPDC. The consequences of these differences in terms of the catalytic and regulatory mechanism of PPDC are discussed.
Patent Rights and Human Rights: Exploring their Relationships
Authors: Haugen Hans Morten
Published: March 2007

The assessment of the relationship between patent rights and human rights has resulted in several tentative findings, such as by the UN Sub‐Commission on the Promotion and Protection of Human Rights, that there are “apparent” or “actual or potential” conflicts. Also the World Intellectual Property Organization says that “conflicts may exist” between the two. This article, which is based on a Ph.D. dissertation on the right to food and the Agreement on Trade‐Related Aspects of Intellectual Property Rights (TRIPS Agreement), analyzes the relationship between the two, based on an established understanding of conflict in international law, namely incompatible obligations. Also another level of conflict is introduced, namely conflict on the level of prescribed measures in one treaty which impedes the taking of measures prescribed by another treaty. Finally, the article assesses conflict on the level of impact. The findings are that strict legal conflict between the two is difficult to establish, but that there are serious concerns regarding their implementation. Developing states should make use of all the flexibilities that the TRIPS Agreement provides.
Surgical repair of femoral fractures in New World camelids: five cases (1996–2003)
Authors: Shoemaker RW , Wilson DG
Published: March 2007

Five New World camelids were admitted to the Western College of Veterinary Medicine between 1996 and 2003 for evaluation of femoral fractures. There were three alpacas and two llamas. Four of the animals were female and three were less than 3 months of age. Fracture configurations consisted of distal physeal fractures (three), a comminuted diaphyseal/metaphyseal fracture, and a transverse diaphyseal fracture. Fractures were diagnosed with a combination of physical examination and radiographs in all cases. All five fractures were repaired with internal fixation and three animals were discharged from the hospital with fractures that healed. One cria underwent successful internal fixation but died from pulmonary oedema during recovery from anaesthesia. Postoperative complications were rare and limited to inadequate fracture stability in one alpaca and prolonged recovery to weight bearing in another. One llama with a comminuted metaphyseal fracture, repaired with a 4.5 mm dynamic compression plate, subsequently had catastrophic failure of the bone 17 days after surgery. Overall the clients were pleased with the outcome of discharged animals. Although femoral fractures are considered rare, they pose a unique opportunity for the large animal veterinarian to successfully achieve fracture union with the aid of internal fixation.
Mapping of a disease susceptibility locus in the HLA region for Primary Biliary Cirrhosis in Japan
Authors: Yahagi Kaichiro , Ueno Yoshiyuki , Nomura Eiki , Fukushima Koji , Moritoki Yuki , Kogure Takayuki , Kojima Yasuhiro , Negoro Kenichi , Kinouchi Yoshitaka , Shimosegawa Tooru
Published: March 2007

Aims:  Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic disease of unknown pathogenesis. However, several reports have demonstrated the involvement of genetic backgrounds in this syndrome. The aim of this study is to examine the genetic disequilibrium in the HLA region in Japanese patients using six microsatellite markers.

Methods:  Genomic DNAs were obtained from 73 patients with PBC (patient cohort) and 186 healthy volunteers (control cohort). Genetic polymorphisms at six microsatellite markers (D6S1568, DQ.CAR, D6S273, TNF‐d, C1‐2‐A, C3‐2‐11) were determined using fluorescence‐labeled polymerase chain reaction (PCR) genetic analyzer. Allele frequencies were estimated by direct counting and the genotypic differentiation test was performed by the Markov chain method using Genepop software.

Results:  Among these six microsatellite markers, four markers in the patients significantly (P < 0.05) deviated from the Hardy–Weinberg equilibrium: DQ.CAR (P = 0.0278), D6S273 (P = 0.0168), TNF‐d (P = 0.0089) and C1‐2‐A (P = 0.0005). Genotypic differentiation test between the patients and controls demonstrated that DQ.CAR (P = 0.0111), TNF‐d (P = 0.0051) and C1‐2‐A (P = 0.0371) were significant. Finally, allelic association test revealed before correction for multiple testing demonstrated allele125 of TNF‐d (P = 0.00065, Pc = 0.0052) and allele246 of C1‐2‐A (P = 0.0026 Pc = 0.033) had significant association after Bonferroni’s correction.

Conclusion:  Disequilibrium mapping using microsatellite markers was a useful method to narrow a disease susceptibility locus. The possible susceptibility gene in the HLA region is thought to be localized around or in the TNF gene. Further studies seem feasible using more closely distributed microsatellite markers or single nucleotide polymorphisms (SNPs) to narrow the susceptibility locus in PBC in Japanese populations.
Gas Turbine Fogging Technology: A State-of-the-Art Review—Part II: Overspray Fogging—Analytical and Experimental Aspects
Authors: Bhargava R. K. , Meher-Homji C. B. , Chaker M. A. , Bianchi M. , Melino F. , Peretto A. , Ingistov S.
Published: March 2007

The strong influence of ambient temperature on the output and heat rate on a gas turbine has popularized the application of inlet fogging and overspray for power augmentation. One of the main advantages of overspray fogging is that it enhances power output as a result of decrease in compression work associated with the continuous evaporation of water within the compressor due to fog intercooling. A comprehensive review on the current understanding of the analytical and experimental aspects of overspray fogging technology as applied to gas turbines is presented in this paper.
Comparative Performance Analysis of Internal and External Reforming of Methanol in SOFC-MGT Hybrid Power Plants
Authors: Cocco Daniele , Tola Vittorio
Published: March 2007

SOFC-MGT hybrid power plants are a very attractive near term option, as they achieve efficiencies of over 60% even for small power outputs (200-400kW). The SOFC hybrid systems currently developed are fuelled with natural gas, which is reformed inside the same stack at about 800-900°C. However, the use of alternative fuels with a lower reforming temperature can lead to enhanced performance of the hybrid power plant. This paper reports a comparative performance analysis of SOFC-MGT power plants fuelled by methane and methanol. Since the reforming temperature of methanol (250-300°C) is significantly lower than that of methane (700-900°C), for the methanol fuelled plant both internal and external reforming have been examined. The performance analysis has been carried out by considering different values for the most important operating parameters of the fuel cell. The comparative analysis has demonstrated that simply replacing methane with methanol in SOFC-MGT power plants with internal reforming slightly reduces the efficiency. However, the use of methanol in SOFC-MGT power plants with external reforming enhances efficiency significantly (by about 4 percentage points). The use of methanol with external fuel reforming raises efficiency of the stack thanks to the improved heat management and to the higher hydrogen partial pressure at the anode inlet.
Kinetics of Jet Fuel Combustion Over Extended Conditions: Experimental and Modeling
Authors: Dagaut Philippe
Published: March 2007

The oxidation of kerosene (Jet-A1) has been studied experimentally in a jet-stirred reactor at 1 to 40atm and constant residence time, over the high temperature range 800-1300K, and for variable equivalence ratio 0.5<φ<2. Concentration profiles of reactants, stable intermediates, and final products have been obtained by probe sampling followed by on-line and off-line GC analyses. The oxidation of kerosene in these conditions was modeled using a detailed kinetic reaction mechanism (209 species and 1673 reactions, most of them reversible). In the kinetic modeling, kerosene was represented by four surrogate model fuels: 100% n-decane, n-decane-n-propylbenzene (74%∕26%mole), n-decane-n-propylcyclohexane (74%∕26%mole), and n-decane-n-propylbenzene-n-propylcyclohexane (74%∕15%∕11%mole). The three-component model fuel was the most appropriate for simulating the JSR experiments. It was also successfully used to simulate the structure of a fuel-rich premixed kerosene-oxygen-nitrogen flame and ignition delays taken from the literature.
Particle Image Velocimetry Measurements of the Three-Dimensional Flow in an Exhaust Hood Model of a Low-Pressure Steam Turbine
Authors: Zhang Wei , Paik Bu Geun , Jang Young Gil , Lee Sang Joon , Lee Su Eon , Kim Jin Hwan
Published: March 2007

The three-dimensional flow structure inside an exhaust hood model of a low-pressure steam turbine was investigated using a particle image velocimetry (PIV) velocity field measurement technique. The PIV measurements were carried out in several selected planes under design operation conditions with simulated total pressure distribution and axial velocity profile. The mean flow fields revealed a complicated vortical flow structure and the major sources of energy loss. Vortices with different scales were observed inside the exhaust hood: a strong separation vortex (SV) behind the tip of the guide vane, a longitudinal vortex (LV) at the exhaust hood top, a large-scale passage vortex (PV) evolving throughout the flow path, and an end-wall vortex (EWV) in the region adjacent to the front end-wall. Both the SV and the large-scale PV seemed to consume large amounts of kinetic energy and reduce the pressure recovery ability. The results indicate that the steam guide vane and the bearing cone should be carefully designed so as to control the vortical flow structure inside the exhaust hood.
Enhanced Splash Models for High Pressure Diesel Spray
Authors: Allocca L. , Andreassi L. , Ubertini S.
Published: March 2007

Mixture preparation is a crucial aspect for the correct operation of modern direct injection (DI) Diesel engines as it greatly influences and alters the combustion process and, therefore, the exhaust emissions. The complete comprehension of the spray impingement phenomenon is a quite complete task and a mixed numerical-experimental approach has to be considered. On the modeling side, several studies can be found in the scientific literature but only in the last years complete multidimensional modeling has been developed and applied to engine simulations. Among the models available in literature, in this paper, the models by Bai and Gosman (Bai, C., and Gosman, A. D., 1995, SAE Technical Paper No. 950283) and by Lee et al. (Lee, S., and Ryou, H., 2000, Proceedings of the Eighth International Conference on Liquid Atomization and Spray Systems, Pasadena, CA, pp. 586–593; Lee, S., Ko, G. H., Ryas, H., and Hong, K. B., 2001, KSME Int. J., 15(7), pp. 951–961) have been selected and implemented in the KIVA-3V code. On the experimental side, the behavior of a Diesel impinging spray emerging from a common rail injection system (injection pressures of 80 and 120MPa) has been analyzed. The impinging spray has been lightened by a pulsed laser sheet generated from the second harmonic of a Nd-yttrium-aluminum-garnet laser. The images have been acquired by a charge coupled device camera at different times from the start of injection. Digital image processing software has enabled to extract the characteristic parameters of the impinging spray with respect to different operating conditions. The comparison of numerical and experimental data shows that both models should be modified in order to allow a proper simulation of the splash phenomena in modern Diesel engines. Then the numerical data in terms of radial growth, height and shape of the splash cloud, as predicted by modified versions of the models are compared to the experimental ones. Differences among the models are highlighted and discussed.
Rayleigh-Bénard Convection in Open and Closed Rotating Cavities
Authors: King Martin P. , Wilson Michael , Owen J. Michael
Published: March 2007

Buoyancy effects can be significant in the rotating annular cavities found between compressor discs in gas-turbine engines, where Rayleigh numbers above 1012 are common. In some engines, the cavity is “closed” so that the air is confined between four rotating surfaces: two discs and inner and outer cylinders. In most engines, however, the cavity is “open” and there is an axial throughflow of cooling air at the center. For open rotating cavities, a review of the published evidence suggests a Rayleigh–Bénard type of flow structure, in which, at the larger radii, there are pairs of cyclonic and anti-cyclonic vortices. The toroidal circulation created by the axial throughflow is usually restricted to the smaller radii in the cavity. For a closed rotating annulus, solution of the unsteady Navier–Stokes equations, for Rayleigh numbers up to 109, show Rayleigh–Bénard convection similar to that found in stationary enclosures. The computed streamlines in the r-θ plane show pairs of cyclonic and anti-cyclonic vortices; but, at the larger Rayleigh numbers, the computed isotherms suggest that the flow in the annulus is thermally mixed. At the higher Rayleigh numbers, the computed instantaneous Nusselt numbers are unsteady and tend to oscillate with time. The computed time-averaged Nusselt numbers are in good agreement with the correlations for Rayleigh–Bénard convection in a stationary enclosure, but they are significantly higher than the published empirical correlations for a closed rotating annulus.
Dynamic Behavior of Spherical Friction Dampers and Its Implication to Damper Contact Stiffness
Authors: Koh K-H. , Griffin J. H.
Published: March 2007

A model that predicts the quasi-static behavior of a friction damper that has spherical contacts was developed using Mindlin’s theory. The model was integrated into a dynamic analysis that predicts the vibratory response of frictionally damped blades. The analytical approach was corroborated through a set of benchmark experiments using a blades/damper test fixture. There was good agreement between the theoretical predictions of amplitude and the values that were measured experimentally over a wide range of test conditions. It is concluded that it is possible to predict the vibratory response of frictionally damped vibrating systems using continuum mechanics, provided that the contact geometry is clearly defined and the local nonlinear contact is correctly taken into account.
Waterjet Peening and Surface Preparation at 600MPa: A Preliminary Experimental Study
Authors: Chillman A. , Ramulu M. , Hashish M.
Published: March 2007

An experimental study was conducted to explore the surface preparation as well as the effects of high-pressure waterjet peening at 600MPa on the surface integrity and finish of metals. The concept of larger droplet size and multiple droplet impacts resulting from an ultra-high-pressure waterjet was used to explore and develop the peening process. A combination of microstructure analysis, microhardness measurements, and profilometry were used in determining the depth of plastic deformation and surface finish that result from the surface treatment process. It was found that waterjet peening at 600MPa induces plastic deformation to greater depths in the subsurface layer of metals than laser shock peening. The degree of plastic deformation and the state of the material surface were found to be strongly dependent on the peening conditions and desired surface roughness. Based on these first investigation results, water peening at 600MPa may serve as a new method for introducing compressive residual stresses in engineering components.
Reversible Electrowetting of Liquid-Metal Droplet
Authors: Wan Zhiliang , Zeng Hongjun , Feinerman Alan
Published: March 2007

This paper reports experimental investigations on the electrowetting effect of liquid metals, e.g., mercury, on dielectric films. Largest contact angle change of 74deg (from 141degto67deg) is achieved on top of a Parylene film. Highly reversible electrowetting with very low hysteresis (2-4deg) is demonstrated on the Teflon®-coated surfaces. The actuation voltage for 30deg contact angle change (from 148degto118deg) is largely reduced to 25V by using a high-dielectric-constant tantalum oxide film as the dielectric layer. The effect of trapped charges in the dielectric film on the electrowetting is observed and measured. The rise and fall times of the electrowetting actuation are inversely proportional to the droplet diameter and as short as 0.1-0.2ms for a 50μmdia droplet. The actuation reliability is tested, and a long-time operation is achieved in an oil environment.
Fiber Orientation Control Related to Papermaking
Authors: Carlsson Allan , Lundell Fredrik , Söderberg L. Daniel
Published: March 2007

The orientation of fibers suspended in a shear flow flowing over a solid wall has been studied experimentally. The possibility to control this orientation with physical surface modifications, ridges, has also been studied. The fiber suspension was driven by gravity down a slightly inclined glass plate and a charge-coupled device camera was used to capture images of the fibers in the flow. Image analysis based on the concept of steerable filters extracted the position and orientation of the fibers in the plane of the image. From these data, the velocity of the fibers was determined. When viewing the flow from the side, the velocity of the fibers at different heights was measured and found to agree with the theoretical solution for Newtonian flow down an inclined plate. Moving the camera so that the flow was filmed from below, the orientation, and velocity of fibers in the plane parallel to the solid surface was determined. The known relationship between the velocity and the wall normal position of the fibers made it possible to determine the height above the plate for each identified fiber. Far away from the wall, the fibers were aligned with the flow direction in both cases. In a region close to the smooth plate surface the fibers oriented themselves perpendicular to the flow direction. This change in orientation did not occur when the surface structure was modified with ridges.
Mixed Convection From a Heated Square Cylinder to Newtonian and Power-Law Fluids
Authors: Dhiman A. K. , Anjaiah N. , Chhabra R. P. , Eswaran V.
Published: March 2007

Steady laminar mixed convection flow and heat transfer to Newtonian and power-law fluids from a heated square cylinder has been analyzed numerically. The full momentum and energy equations along with the Boussinesq approximation to simulate the buoyancy effects have been solved. A semi-explicit finite volume method with nonuniform grid has been used for the range of conditions as: Reynolds number 1–30, power-law index: 0.8–1.5, Prandtl number 0.7–100 (Pe⩽3000) for Richardson number 0–0.5 in an unbounded configuration. The drag coefficient and the Nusselt number have been reported for a range of values of the Reynolds number, Prandtl number, and Richardson number for Newtonian, shear-thickening (n>1) and shear-thinning (n<1) fluids. In addition, detailed streamline and isotherm contours are also presented to show the complex flow field, especially in the rear of the cylinder. The effects of Prandtl number and of power-law index on the Nusselt number are found to be more pronounced than that of buoyancy parameter (Ri⩽0.5) for a fixed Reynolds number in the steady cross-flow regime (Re⩽30).
Rates of and Reasons for Failure of Commercial Human Immunodeficiency Virus Type 1 Viral Load Assays in Brazil
Authors: Drexler Jan Felix , de Souza Luna Luciano Kleber , Pedroso Celia , Pedral-Sampaio Diana Brasil , Queiroz Artur T. L. , Brites Carlos , Netto Eduardo M. , Drosten Christian
Published: March 2007

We examined failures of commercial human immunodeficiency virus type 1 (HIV-1) viral load assays of 1,195 plasma samples from Brazilian patients. Assay failure was assumed for samples in which the virus was undetectable by commercial assay but which tested positive by real-time reverse transcription-PCR of the HIV-1 long terminal repeat (LTR) region or if the viral load differed by >2 log
10
from that determined by LTR assay. Failure rates for Bayer Versant bDNA 3.0, Roche Amplicor Monitor v1.5, and bioMerieux NucliSens QT were 0.68, 0.47, and 4.33%, respectively. NucliSens may be inadequate for use in Brazil.
First Case of Human Babesiosis in Korea: Detection and Characterization of a Novel Type of
Babesia
sp. (KO1) Similar to Ovine
Babesia
Authors: Kim Jung-Yeon , Cho Shin-Hyeong , Joo Hyun-Na , Tsuji Masayoshi , Cho Sung-Ran , Park Il-Joong , Chung Gyung-Tae , Ju Jung-Won , Cheun Hyeng-Il , Lee Hyeong-Woo , Lee Young-Hee , Kim Tong-Soo
Published: March 2007

We report on the first case of human babesiosis in Korea. The intraerythrocytic parasite (KO1) in the patient's blood mainly appeared as paired pyriforms and ring forms; but Maltese cross forms were not seen, and the parasite showed morphological features consistent with those of the genus
Babesia
sensu stricto. The sequence of the 18S rRNA gene of KO1 was closely related to that of
Babesia
spp. isolated from sheep in China (similarity, 98%). The present study provides the first evidence of the presence of a hitherto unidentified, new type of
Babesia
parasite capable of infecting humans.
Molecular Investigations of an Outbreak of Parainfluenza Virus Type 3 and Respiratory Syncytial Virus Infections in a Hematology Unit
Authors: Jalal Hamid , Bibby David F. , Bennett Julie , Sampson Rebecca E. , Brink Nicola S. , MacKinnon Stephen , Tedder Richard S. , Ward Katherine N.
Published: March 2007

A large simultaneous outbreak of respiratory syncytial virus (RSV) and parainfluenza type 3 (PIV-3) infections occurred on an adult hematology unit. Implementation of enhanced infection control was complicated by cocirculation of the two different viruses, with prolonged viral shedding from infected patients, and placed great pressure on health care staff; of 27 infected hematopoietic stem cell transplant patients, 9 died, and the unit was closed for 2 months. Retrospective molecular investigation of the virus strains involved in the outbreak was performed by analyzing part of the fusion gene of PIV-3 and part of the glycoprotein gene of RSV. Reverse transcription-PCR on nasopharyngeal aspirates from patients infected before and during the simultaneous outbreak generated amplicons for sequence analysis. A single strain of RSV and a single strain of PIV-3 had spread from person to person within the unit; 7 patients were infected with RSV, 22 were infected with PIV-3, and 4 were infected with both viruses. The PIV-3 outbreak had started at the beginning of August 3 months before the RSV outbreak; it had arisen when PIV-3 was introduced from the community by a patient and passed to another patient, who became chronically infected with the identical strain and, in spite of being nursed in isolation, was most likely the source from which widespread infection occurred in November. Had these early cases been linked to a common PIV-3 strain at the time of diagnosis, enhanced infection control precautions might have prevented the eventual extensive spread of PIV-3, making it much easier to deal with the later RSV outbreak.
Acute Postoperative Endophthalmitis Caused by
Staphylococcus lugdunensis
Authors: Chiquet C. , Pechinot A. , Creuzot-Garcher C. , Benito Y. , Croize J. , Boisset S. , Romanet J. P. , Lina G. , Vandenesch F.
Published: March 2007

Acute postoperative endophthalmitis caused by
Staphylococcus lugdunensis
is infrequently reported in clinical studies. Five cases of acute postcataract surgery endophthalmitis caused by
S. lugdunensis
were taken from a multicenter prospective study conducted in four university-affiliated hospitals in France (2004 to 2005). These cases were characterized by severe ocular inflammation occurring with a mean delay of 7.6 days after cataract surgery, severe visual loss (hand motions or less in three cases), and dense infiltration of the vitreous. Each of these patients was initially treated by using a standard protocol with intravitreal (vancomycin and ceftazidime), systemic, and topical antibiotics. Given the severity of the endophthalmitis, even though bacteria were sensitive to intravitreal antibiotics, pars plana vitrectomy was needed in four cases. The final visual prognosis was complicated by severe retinal detachment in three cases. The microbiological diagnosis was reached by using conventional cultures with specific biochemical tests and eubacterial PCR amplification followed by direct sequencing.
Enteric Ganglionitis in Rhesus Macaques Infected with Simian Immunodeficiency Virus
Authors: Orandle Marlene S. , Veazey Ronald S. , Lackner Andrew A.
Published: March 2007

Gastrointestinal (GI) disease is a debilitating feature of human immunodeficiency virus (HIV) infection that can occur in the absence of histopathological abnormalities or identifiable enteropathogens. However, the mechanisms of GI dysfunction are poorly understood. The present study was undertaken to characterize changes in resident and inflammatory cells in the enteric nervous system (ENS) of macaques during the acute stage of simian immunodeficiency virus (SIV) infection to gain insight into potential pathogenic mechanisms of GI disease. Ganglia from duodenum, ileum, and colon were examined in healthy and acutely infected macaques by using a combination of routine histology, double-label immunofluorescence and in situ hybridization. Evaluation of tissues from infected macaques showed progressive infiltration of myenteric ganglia by CD3+T cells and IBA1+macrophages beginning as early as 8 days postinfection. Quantitative image analysis revealed that the severity of myenteric ganglionitis increased with time after SIV infection and, in general, was more severe in ganglia from the small intestine than in ganglia from the colon. Despite an abundance of inflammatory cells in myenteric ganglia during acute infection, the ENS was not a target for virus infection. This study provides evidence that the ENS may be playing a role in the pathogenesis of GI disease and enteropathy in HIV-infected people.
Murine Gammaherpesvirus 68 Open Reading Frame 24 Is Required for Late Gene Expression after DNA Replication
Authors: Wong Elaine , Wu Ting-Ting , Reyes Nichole , Deng Hongyu , Sun Ren
Published: March 2007

Open reading frame 24 (ORF24) of murine gammaherpesvirus 68 (MHV-68) is conserved among beta- and gammaherpesviruses; however, its function in viral replication has not been defined. Using MHV-68 as a model, we have identified ORF24 as being essential for viral replication. An ORF24-null virus was generated and shown to be defective in late gene expression. Expression of early genes, as well as viral genome replication, was not affected. Furthermore, the defect in late gene expression was likely due to a deficiency in transcription. Thus, we have identified an MHV-68 protein, ORF24, that is essential for the expression of viral late proteins yet dispensable for viral DNA replication.
Murine Hepatitis Virus Replicase Protein nsp10 Is a Critical Regulator of Viral RNA Synthesis
Authors: Donaldson Eric F. , Sims Amy C. , Graham Rachel L. , Denison Mark R. , Baric Ralph S.
Published: March 2007

Coronavirus replication requires proteolytic processing of the large polyprotein encoded by ORF1a/ab into putative functional intermediates and eventually ∼15 mature proteins. The C-terminal ORF1a protein nsp10 colocalizes with viral replication complexes, but its role in transcription/replication is not well defined. To investigate the role of nsp10 in coronavirus transcription/replication, alanine replacements were engineered into a murine hepatitis virus (MHV) infectious clone in place of conserved residues in predicted functional domains or charged amino acid pairs/triplets, and rescued viruses were analyzed for mutant phenotypes. Of the 16 engineered clones, 5 viable viruses were rescued, 3 mutant viruses generated no cytopathic effect but were competent to synthesize viral subgenomic RNAs, and 8 were not viable. All viable mutants showed reductions in growth kinetics and overall viral RNA synthesis, implicating nsp10 as being a cofactor in positive- or negative-strand synthesis. Viable mutant nsp10-E2 was compromised in its ability to process the nascent polyprotein, as processing intermediates were detected in cells infected with this virus that were not detectable in wild-type infections. Mapping the mutations onto the crystal structure of severe acute respiratory syndrome virus nsp10 identified a central core resistant to mutation. Mutations targeting residues in or near either zinc-binding finger generated nonviable phenotypes, demonstrating that both domains are essential to nsp10 function and MHV replication. All mutations resulting in viable phenotypes mapped to loops outside the central core and were characterized by a global decrease in RNA synthesis. These results demonstrate that nsp10 is a critical regulator of coronavirus RNA synthesis and may play an important role in polyprotein processing.
Lignan Glucosides and Serotonin Phenylpropanoids from the Seeds of Leuzea carthamoides
Authors: Harmatha Juraj , Buděšínský Miloš , Vokáč Karel , Pavlík Milan , Grüner Karel , Laudová Věra
Published: March 2007

Two lignan glucosides, the known tracheloside and the new carthamoside, together with their two known aglycones, trachelogenin and (7E,8'S)-7,8-didehydroarctigenin (cf. cartha- mogenin), were isolated from the seeds of Leuzea carthamoides. Additional four phenylpropanoid derivatives of tryptamine, the E and Z isomers of N-feruloylserotonin and N-isoferuloylserotonin, were also isolated and identified. Their structure determination and identification were performed by spectroscopic, mainly NMR analysis.
Photocatalytic Degradation of NOx Over Platinum and Nitrogen Codoped Titanium Dioxide Under Visible Light Irradiation
Authors: Zhou Lin , Tan Xin , Zhao Lin , Sun Ming
Published: March 2007

In order to utilize visible light and enhance the catalytic efficiency in photocatalytic conversion of NOx, nitrogen and platinum atoms were doped in commercially available photocatalytic TiO2 powders by impregnating and photodeposition methods, respectively. X-ray diffraction (XRD) showed that the crystal structures of TiO2 were not changed after the doping process. Analysis by X-ray photoelectron spectroscopy (XPS) indicated that N atoms were incorporated in the bulk phase of TiO2 as N-Ti-O linkages and Pt atoms were at the surface. A significant shift of the absorption edge to lower energy and higher absorption in the visible light region were observed. This Pt,N-codoped TiO2 powder exhibited excellent photocatalytic activity and fairly stable chemical property for the degradation of NOx under visible light irradiation. The sample mixed with 20 wt.% ammonium carbonate and doped with 0.5 at.% platinum atoms showed the best photocatalytic activity and its activity can be restored by rinsing with water after long-term operation.
Asian herbal-tobacco cigarettes: “not medicine but less harmful”?: Table 1
Authors: Chen Aiyin , Glantz Stanton , Tong Elisa
Published: March 2007

Objective:To describe the development and health claims of Asian herbal-tobacco cigarettes.

Methods:Analysis of international news sources, company websites, and the transnational tobacco companies’ (TTC) documents. PubMed searches of herbs and brands.

Results:Twenty-three brands were identified, mainly from China. Many products claimed to relieve respiratory symptoms and reduce toxins, with four herb-only products advertised for smoking cessation. No literature was found to verify the health claims, except one Korean trial of an herb-only product. Asian herbal-tobacco cigarettes were initially produced by China by the 1970s and introduced to Japan in the 1980s. Despite initial news about research demonstrating a safer cigarette, the TTC analyses of these cigarettes suggest that these early products were not palatable and had potentially toxic cardiovascular effects. By the late 1990s, China began producing more herbal-tobacco cigarettes in a renewed effort to reduce harmful constituents in cigarettes. After 2000, tobacco companies from Korea, Taiwan, and Thailand began producing similar products. Tobacco control groups in Japan, Taiwan, and Thailand voiced concern over the health claims of herbal-tobacco products. In 2005, China designated two herbal-tobacco brands as key for development.

Conclusion:Asian herbal-tobacco cigarettes claim to reduce harm, but no published literature is available to verify these claims or investigate unidentified toxicities. The increase in Asian herbal-tobacco cigarette production by 2000 coincides with the Asian tobacco companies’ regular scientific meetings with TTCs and their interest in harm reduction. Asia faces additional challenges in tobacco control with these culturally concordant products that may discourage smokers from quitting.
EXISTENCE AND GLOBAL EXPONENTIAL STABILITY OF PERIODIC SOLUTION OF A CLASS OF IMPULSIVE NETWORKS WITH INFINITE DELAYS
Authors: XIA YONGHUI , CAO JINDE , LIN MUREN
Published: March 2007

Sufficient conditions are obtained for the existence and global exponential stability of a unique periodic solution of a class of impulsive tow-neuron networks with variable and unbounded delays. The approaches are based on Mawhin's continuation theorem of coincidence degree theory and Lyapunov functions.
INVESTIGATION OF SPONTANEOUS CHIRAL-SYMMETRY BREAKING FROM LATTICE QCD WITH MASSLESS QUARKS
Authors: LUO XIANG-QIAN
Published: March 2007

We apply the probability distribution function method to the study of chiral properties of QCD with quarks in the exact massless limit. A relation among the chiral condensate, zeros of the Bessel function and eigenvalue of Dirac operator is also given. The chiral condensate in this limit can be measured with small number of eigenvalues of the massless Dirac operator and without any ambiguous mass extrapolation. Results for lattice QCD with Kogut-Susskind quarks are shown.
SCHRÖDINGER FUNCTIONAL FORMALISM WITH GINSPARG-WILSON FERMION
Authors: TANIGUCHI YUSUKE
Published: March 2007

In this proceeding we propose a new procedure to impose the Schrödinger functional Dirichlet boundary condition on the overlap Dirac operator and the domain-wall fermion using an orbifolding projection. With this procedure the zero mode problem with Dirichlet boundary condition can easily be avoided.
OVERLAP FERMIONS IN THE STRONG COUPLING LIMIT
Authors: YE PENG , YU XIAO-LU , GUAN YI , LUO XIANG-QIAN
Published: March 2007

We analyze the overlap fermion formulation expanded in powers of a hopping parameter in the strong coupling limit. The mass of the quasi-Goldstone pion is obtained. A random walk representation for the overlap fermion propagator is developed, to conclude that the expanded overlap fermion formulation, however, cannot be totally solve the fermion-doubling problem.
H-Dibaryon from Lattice QCD with Improved Anisotropic Actions
Authors: Luo Zhi-Huan , Loan Mushtaq , Luo Xiang-Qian
Published: March 2007

The six quark state(uuddss) called H dibaryon(JP = 0+,S = -2) has been calculated to study its existence and stability. The simulations are performed in quenched QCD on 83 × 24 and 163 × 48 anisotropic lattices with Symanzik improved gauge action and Clover fermion action. The gauge coupling is β = 2.0 and aspect ratio ξ = as/at = 3.0. Preliminary results indicate that mass of H dibaryon is 2134(100)Mev on 83 × 24 lattice and 2167(59)Mev on 163 × 48 respectively. It seems that the radius of H dibaryon is very large and the finite size effect is very obvious.
QCD IN HADRONIC B DECAYS
Authors: LÜ CAI-DIAN
Published: March 2007

The perturbative QCD approach is based on kT factorization, including the Sudakov form factors so that to avoid the endpoint singularity. In this approach, we calculate the charmless B decays like B → ππ decays etc. to produce the right number of branching ratios and also CP asymmetry parameters. For final states with at least one charmed meson, like B → Dπ decays, our results also agree with the experiments.
SOME TESTS ON CPT INVARIANCE
Authors: GENG C. Q. , GENG LEI
Published: March 2007

We first briefly review tests on CPT invariance based on the consequences of the CPT theorem and then present some possible CPT tests due to exotic models in which some of the CPT conditions are lost, such as those without hermiticity.
MODEL DEPENDENT ANALYSES ON THE Nc DEPENDENCE OF THE σ POLE TRAJECTORY
Authors: SUN Z. X. , XIAO L. Y. , XIAO Z. G. , ZHENG H. Q.
Published: March 2007

We explore the nature of the σ or f0(600) meson using large Nc technique, assuming that the σ pole dominates low energy physics in the IJ =00 channel. We trace the Nc dependence of the σ pole position using [1,1] Padé approximation of SU(3) chiral amplitude, [1,2] Padé approximation of SU(2) chiral amplitudes, and the PKU parametrization form. We find that in all 3 cases the σ pole moves to the real axis of the complex s-plane. Finally we construct a pedagogical example using the SU(2) Padé amplitude to show that when the analyticity property of the scattering amplitude is violated, it is possible that the σ pole resides on the complex s plane when Nc is large.
ELECTRODYNAMICS FOR NUCLEAR MATTER IN BULK
Authors: RUFFINI REMO , ROTONDO MICHAEL , XUE SHE-SHENG
Published: March 2007

We present an approach to analyze the electrodynamics of nuclear matter in bulk using the relativistic Thomas–Fermi equation. We generalize to the case of N ≃ (m Planck /m n )3 nucleons of mass m n an approach well tested in very heavy nuclei (Z ≃ 106). Particular attention is given to implement the condition of charge neutrality globally on the entire configuration, versus the one usually adopted on a microscopic scale. As the limit N ≃ (m Planck /m n )3 is approached the penetration of electrons inside the core increases and a relatively small tail of electrons persists leading to a significant electron density outside the core. Within a region of 102 electron Compton wavelength near the core, surface electric fields close to the critical value for pair creation by vacuum polarization effect develop. These results can have important consequences on the understanding of physical process in neutron star structures as well as on the initial conditions leading to the process of gravitational collapse to a black hole.
STATIC CHARGED DILATON BLACK HOLE SOLUTIONS IN NON-COMMUTATIVE SPACES
Authors: SETARE M. R. , SADEGHI J.
Published: March 2007

Here we consider the black hole solutions which were obtained by Chan and Mann.1 These solutions represent static charged black holes with a dilaton field. Then we compute the corrections to the horizons and Hawking temperature of these black holes. These corrections stem from the space non-commutativity. We show that in a non-commutative case, temperature of extreme black hole, in contrast to that of the commutative case, is not zero.
WHITE NOISE HEISENBERG EVOLUTION AND EVANS–HUDSON FLOWS
Authors: ACCARDI LUIGI , AYED WIDED , OUERDIANE HABIB
Published: March 2007

We study white noise Heisenberg equations giving rise to flows which are *-automorphisms of the observable algebra, but not necessarily inner automorphisms. We prove that the causally normally ordered form of these white noise Heisenberg equations are equivalent to Evans–Hudson flows. This gives in particular, the microscopic structure of the maps defining these flows, in terms of the original white noise derivations.
Structural and regulatory roles of muscle ankyrin repeat protein family in skeletal muscle
Authors: Barash Ilona A. , Bang Marie-Louise , Mathew Liby , Greaser Marion L. , Chen Ju , Lieber Richard L.
Published: March 2007

The biological response of muscle to eccentric contractions (ECs) results in strengthening and protection from further injury. However, the cellular basis for this response remains unclear. Previous studies identified the muscle ankyrin repeat protein ( MARP) family, consisting of cardiac ankyrin repeat protein ( CARP), ankyrin repeat domain 2/ankyrin repeat protein with PEST and proline-rich region ( Ankrd2/Arpp), and diabetes-associated ankyrin repeat protein ( DARP), as rapidly and specifically upregulated in mice after a single bout of EC. To determine the role of these genes in skeletal muscle, a survey of skeletal muscle structural and functional characteristics was performed on mice lacking all three MARP family members (MKO). There was a slight trend toward MKO muscles having a slower fiber type distribution but no differences in muscle fiber size. Single MKO fibers were less stiff, tended to have longer resting sarcomere lengths, and expressed a longer isoform of titin than their wild-type counterparts, indicating that these proteins may play a role in the passive mechanical behavior of muscle. Finally, MKO mice showed a greater degree of torque loss after a bout of ECs compared with wild-type mice, although they recovered from the injury with the same or even improved time course. This recovery was associated with enhanced expression of the muscle regulatory genes MyoD and muscle LIM protein ( MLP), suggesting that the MARP family may play both important structural and gene regulatory roles in skeletal muscle.
Relocalization of the V-ATPase B2 subunit to the apical membrane of epididymal clear cells of mice deficient in the B1 subunit
Authors: Da Silva Nicolas , Shum Winnie W. C. , El-Annan Jaafar , Păunescu Teodor G. , McKee Mary , Smith Peter J. S. , Brown Dennis , Breton Sylvie
Published: March 2007

An acidic luminal pH in the epididymis contributes to maintaining sperm quiescent during their maturation and storage. The vacuolar H+ATPase (V-ATPase), located in narrow and clear cells, is a major contributor to luminal acidification. Mutations in one of the V-ATPase subunits, ATP6v1B1 (B1), cause distal renal tubular acidosis in humans but surprisingly, B1−/− mice do not develop metabolic acidosis and are fertile. While B1 is located in the apical membrane of narrow and clear cells, the B2 subunit localizes to subapical vesicles in wild-type mouse, rat and human epididymis. However, a marked increase (84%) in the mean pixel intensity of B2 staining was observed in the apical pole of clear cells by conventional immunofluorescence, and relocalization into their apical membrane was detected by confocal microscopy in B1−/− mice compared with B1+/+. Immunogold electron microscopy showed abundant B2 in the apical microvilli of clear cells in B1−/− mice. B2 mRNA expression, determined by real time RT-PCR using laser-microdissected epithelial cells, was identical in both groups. Semiquantitative Western blots from whole epididymis and cauda epididymidis showed no variation of B2 expression. Finally, the luminal pH of the cauda epididymidis was the same in B1−/− mice as in B1+/+ (pH 6.7). These data indicate that whereas overall expression of B2 is not affected in B1−/− mice, significant redistribution of B2-containing complexes occurs from intracellular compartments into the apical membrane of clear cells in B1−/− mice. This relocation compensates for the absence of functional B1 and maintains the luminal pH in an acidic range that is compatible with fertility.
Apoptosis and Id2 expression in diaphragm and soleus muscle from the emphysematous hamster
Authors: Degens Hans , Swisher Anne K. , Heijdra Yvonne F. , Siu Parco M. , Richard Dekhuijzen P. N. , Alway Stephen E.
Published: March 2007

During chronic obstructive pulmonary disease (COPD) diaphragm and peripheral muscle weakness occur. Muscle remodeling and wasting may be a result of apoptosis and changes in muscle-specific transcription factors, such as MyoD, altering muscle-specific gene transcription and muscle regenerative capacity. To investigate this, we instilled under ketamine/xylazine anesthesia porcine elastase in the lungs of hamsters to induce emphysema. The emphysematous hamster is an accepted model for COPD. In the diaphragm and peripheral muscles we assessed the occurrence of apoptosis, and in the diaphragm and soleus also the expression of MyoD and inhibitor of differentiation protein 2 (Id2). There was no significant muscle atrophy in emphysematous hamsters. The mRNA levels of TNF-α and markers of apoptosis were significantly elevated in the diaphragm and soleus muscles during emphysema. This was accompanied by an increased presence of nucleosomes in the cytosol. Caspase 3 activity and the DNA-binding activity of the p65 subunit of NF-κB, however, were unaltered in all muscles. The protein expression of MyoD and Id2 were decreased and increased in the diaphragm and the soleus muscle, respectively. Thus, despite the absence of muscle atrophy in emphysematous hamsters, there was evidence of increased TNF-α expression, apoptosis, and altered muscle-specific transcriptional regulation as reflected by decreased MyoD and elevated Id2 levels at least in the soleus and diaphragm muscle. These alterations may impair the regenerative capacity of skeletal muscles and ultimately contribute to muscle wasting.