bluuebunny/crossref_metadata_2025_split huggingface dataset:
c/a Ratio‐Dependent Energy‐Storage Density in (0.9−x)Bi0.5Na0.5TiO3–xBaTiO3–0.1K0.5Na0.5NbO3 Ceramics
Authors: Gao Feng , Dong Xianlin , Mao Chaoliang , Cao Fei , Wang Genshui 
Published: October 2011

The (0.9−x)Bi0.5Na0.5TiO3–xBaTiO3–0.1K0.5Na0.5NbO3 [BNBKN(x), x = 0.060, 0.063, 0.066, and 0.069] ceramics were fabricated by the conventional sintering technique. The P–E hysteresis loops measured under 5 kV/mm at room temperature show that the BNBKN(0.063) ceramics obtain the maximum (Ps−Pr) value of 20.6 μC/cm2 and the largest energy‐storage density W of 0.424 J/cm3. In addition, calculation from the X‐ray diffraction results shows that the BNBKN(0.063) ceramics are featured with the largest c/a ratio of 0.70887. The W is observed to increase with the increase of the c/a ratio in the BNBKN(x) ceramics. The c/a ratio can be regarded as a significant factor for W in the BNBKN(x) ceramics.
Solid‐State Reactive Sintering and Optical Characteristics of Transparent Er:YAG Laser Ceramics
Authors: Li Jiang , Zhou Jun , Pan Yubai , Liu Wenbin , Zhang Wenxin , Guo Jingkun , Chen Hao , Shen Deyuan , Yang Xiaofang , Zhao Ting 
Published: October 2011

Highly transparent Er:YAG ceramics were fabricated by solid‐state reactive sintering using a mixture of commercial α‐Al2O3, Y2O3, and Er2O3 powders with tetraethoxysilane and MgO as sintering aids. A fully dense 1.0 at.% Er:YAG ceramic with an average grain size of ~25 μm was obtained by vacuum sintering at 1800°C for 30 h. The in‐line transmittance reached 83% near the lasing wavelength of 1645 nm with a scattering loss of ~0.02 cm−1. Laser operation of such a Er:YAG ceramic rod (4.0 mm × 4.0 mm × 10.8 mm) was demonstrated at 1645 nm with a slope efficiency of 51% under resonant pumping at 1532 nm, and the maximum continuous‐wave laser output was 13 W.
Jichengite 3CuIr2S4·(Ni, Fe)9S8, a New Mineral, and Its Crystal Structure
Authors: YÜ Zuxiang , HAO Ziguo , WANG Hanggen , YIN Shuping , CAI Jianhui 
Published: October 2011

Abstract:A new mineral, jichengite ideally 3CuTr2S4·(Ni,Fe)9S8, was found as a constituent of placer concentrates at a branch of the Luanhe River, about 220 km NNE of Beijing. Its associated minerals are chromite, magnetite, ilmenite, zircon, native gold, iridium, ferrian platinum and osmium. The placer is distributed at places around ultrabasic rock, which hosts chromite orebodies, from which PGM originated. Jichengite occurs commonly as massive or granular aggregates. No perfect morphology of jichengite was observed. It is steel gray and opaque with metallic luster and black streak. It has a Mohs hardness of 5, VHN (d) μm 21.65, Hm 4.465, Hv = 268.1 N/um2. It is brittle and weakly magnetic. Cleavage {010} is rarely observed. No fracture was observed. Density could not be measured because of its too small grain size. Density (calc.) is 7.003 g/cm3. Reflect light is reddish‐brown, without internal reflections. Anisotropism is distinct with grayish or yellowish white in crossed nicols and bluish violet‐copper red in uncrossed nicols. Jichengite shows weak pleochroism and strong bireflectance. The reflectance values in air at the Standard Commission on Ore Mineralogy wavelengths are: 38.9, 34.3 at 470 nm, 38.9, 34.5 at 546 nm, 39.1, 35.3 at 590 nm, 39.2, 36.8 at 650 nm, parallel‐axial extinction. The six strongest lines in the X‐ray powder‐diffraction pattern [d in Å, (I), (hkl)] are: 3.00 (100) (116), 2.80 (50) (205), 2.48. (50) (208), 1.916 (40) (2, 1, 10), 1.765 (60) (220), 1.753 (50) (2, 0, 16). Five chemical analyses carried out, yielding the following results: S 25.76 (25.49–5.97), Fe 10.03 (9.78–10.31), Co 0.78 (0.75–0.81), Ni 12.48 (12.32–12.85), Cu 4.77 (4.69–1.83), Ir 46.98(46.14–17.89), sum 100.80wt%, which produced a formula (Cu1.556Fe0.976)2.532(Ir5.063S10.126)·(Fe2.7451Ni4.404Co0.273)7.422S6.517. The ideal formula is X10Ir5S17.5, which was calculated by single crystal structure analyses, where X = Cu(II) + Fe(II) + Ni(II) + Co(II). The single crystal data were collected using a diffractometer with Mo Kα radiation and a graphite monochromate. The crystal system is trigonal with space group R3m and unit cell parameters a=7.0745(14) Å, c=34.267(10) Å (The superstructure not found), and the final R Indices [with 564 observed reflections, I>2sigma (I)] are R1=0.0495, wR2=0.1349. The specimens are deposited in the Geological Museum of China.
Analysis of Reservoir Forming Conditions and Prediction of Continuous Tight Gas Reservoirs for the Deep Jurassic in the Eastern Kuqa Depression, Tarim Basin
Authors: ZOU Caineng , JIA Jinhua , TAO Shizhen , TAO Xiaowan 
Published: October 2011

Abstract:The exploration targets in the Kuqa Depression at present are mainly structure traps in Cretaceous‐Tertiary. Due to the complexity of mountain distribution and reservoir forming conditions, the exploration of Jurassic in the eastern Kuqa Depression has been in a state of semi‐stagnation since the discovery of the Yinan‐2 gas reservoir. According to the concept and theory of “continuous petroleum reservoirs” and the re‐analysis of the forming conditions of the Yinan‐2 gas reservoir and regional natural gas in the eastern Kuqa Depression, it is believed that the deep Jurassic has good natural gas accumulation conditions as well as geological conditions for forming continuous tight gas reservoirs. The boundary of the Yinan‐2 gas reservoir is not controlled by a structural spillpoint. The downdip part of the structure is dominated by gas, while the hanging wall of the fault is filled by water and forming obvious inverted gas and water. The gas reservoir has the normal temperature and ultrahigh pressure which formed in the near source or inner‐source. All of these characteristics indicate that the Yinan‐2 gas reservoir is different from conventional gas reservoirs. The deep Jurassic in the eastern Kuqa Depression has multisets of source‐reservoir‐cap assemblages, which comprise interbedded sandstones and mudstones. These assemblages are characterized by a self‐generation, self‐preserving and self‐coverage model. Reservoir sandstones and coal measure mudstones are interbedded with each other at a large scale. As the source rocks, Triassic‐Jurassic coal measure mudstones distribute continuously at a large scale and can generate and expel hydrocarbon. Source rocks contact intimately with the overlying sandstone reservoirs. During the late stage of hydrocarbon expulsion, natural gas charged continuously and directly into the neighboring reservoirs. Petroleum migrated mainly in a vertical direction over short distances. With ultra‐high pressure and strong charging intensity, natural gas accumulated continuously. Reservoirs are dominated by sandstones of braided delta facies. The sand bodies distribute continuously horizontal. With low porosity and low permeability, the reservoirs are featured by strong heterogeneity. It is hypothesized that the sandstones of the interior depression tend to be relatively tight with increasing depth and structure stress weakness. Thus, it is predicted that continuous tight gas reservoirs of ultra‐high pressure may exist in the deep formations of the eastern and even the whole Kuqa Depression. So, it is worth evaluating the exploration potential.
Clinical outcome of esophageal varices after hepatic arterial infusion chemotherapy for advanced hepatocellular carcinoma with major portal vein tumor thrombus
Authors: Kodama Hideaki , Aikata Hiroshi , Murakami Eisuke , Miyaki Daisuke , Nagaoki Yuko , Hashimoto Yoshimasa , Azakami Takahiro , Katamura Yoshio , Kawaoka Tomokazu , Takaki Shintaro , Hiramatsu Akira , Waki Koji , Imamura Michio , Kawakami Yoshiiku , Takahashi Shoichi , Ishikawa Masaki , Kakizawa Hideaki , Awai Kazuo , Kenjo Masahiro , Nagata Yasushi , Chayama Kazuaki 
Published: October 2011

Aim:  To analyze the clinical outcome of esophageal varices (EV) after hepatic arterial infusion chemotherapy (HAIC) in patients with advanced hepatocellular carcinoma (HCC) and major portal vein tumor thrombus (Vp3/4).Methods:  The study subjects were 45 consecutive patients who received HAIC for HCC with Vp3/4 between January 2005 and December 2009. HAIC comprised the combination therapy of intra‐arterial 5‐FU with interferon‐α (5‐FU/IFN) in 23 patients and low‐dose cisplatin plus 5‐FU (FP) in 22. Radiotherapy (RT) was also provided in 19 patients for portal vein tumor thrombosis. Aggravation rate for EV and overall survival rate were analyzed.Results:  The aggravation rates for EV were 47% and 64% at 12 and 24 months, respectively. The survival rates were 47% and 33% at 12 and 24 months, respectively. The response rates to 5‐FU/IFN and FP were 35% and 41%, while the disease control rates in these two groups were 57% and 50%, respectively. There were no significant differences in the objective response and disease control between 5‐FU/IFN and FP. Multivariate analysis identified size of EV (F2/F3) (HR = 7.554, P = 0.006) and HCC disease control (HR = 5.948, P = 0.015) as significant and independent determinants of aggravation of EV, and HCC disease control (HR = 12.233, P < 0.001), metastasis from HCC (HR = 11.469, P = 0.001), ascites (HR = 8.825, P = 0.003) and low serum albumin (HR = 4.953, P = 0.026) as determinants of overall survival. RT for portal vein tumor thrombosis tended to reduce the aggravation rate for EV in patients with these risk factors.Conclusions:  Hepatocellular carcinoma disease control was the most significant and independent factor for aggravation of EV and overall survival in HCC patients with major portal vein tumor thrombosis treated with HAIC.
Israel–Syria: The Elusive Peace*
Authors: Olmert Josef 
Published: October 2011

AbstractFor 20 years, as of 1991, multiple rounds of negotiations took place between Syria and Israel. These negotiations revolved around the entire gamut of problems separating the two countries: borders, recognition, finality of the conflict, normalization, security arrangements, the Israeli civilian population in the disputed territory, water, Lebanon, the Palestinian issue, Iran, and terrorism. Israeli Prime Ministers, Syrian presidents, foreign ministers, and senior generals from both sides participated in the talks, and third parties such as the United States and Turkey were also involved. Yet peace was not achieved, although not for a lack of effort. This article tries to shed light on some of the reasons for this continuing failure.
Mediation of Host Immune Responses after Immunization of Neonatal Calves with a Heat-Killed Mycobacterium avium subsp. paratuberculosis Vaccine
Authors: Stabel J. R. , Waters W. R. , Bannantine J. P. , Lyashchenko K. 
Published: October 2011

ABSTRACT

A major drawback of current whole-cell vaccines for
Mycobacterium avium
subsp.
paratuberculosis
is the interference with diagnostic tests for bovine tuberculosis (TB) and paratuberculosis. The current study was designed to explore the effects of immunization with a heat-killed whole-cell vaccine (Mycopar) on diagnostic test performance and to characterize host immune responses to vaccination over a 12-month period. Neonatal dairy calves were assigned to treatment groups consisting of (i) controls, not vaccinated (
n
= 5), and (ii) vaccinates, vaccinated with Mycopar vaccine (
n
= 5). The results from this study demonstrated a rapid initiation of
M. avium
subsp.
paratuberculosis
-specific gamma interferon (IFN-γ) in vaccinated calves by 7 days, with robust responses throughout the study. Vaccinated calves also had responses to
M. bovis
purified protein derivative tuberculin (BoPPD) but minimal reactivity to ESAT-6/CFP-10, an
M. bovis
recombinant fusion protein. The levels of antigen-specific interleukin-4 (IL-4) and IL-10 were markedly decreased in vaccinated calves between days 7 and 90 of the study but thereafter were similar to the levels in controls. Vaccinated calves began to seroconvert at 4 months, with 4/5 calves having detectable
M. avium
subsp.
paratuberculosis
antibody by 6 months. The responses in test platforms for bovine TB were negligible in the vaccinate group, as only one calf had a response, which was in the suspect range of the comparative cervical skin test. Serum antibody responses to
M. bovis
antigens ESAT-6, CFP-10, and MPB83 were negative on the Vet TB STAT-PAK, DPP VetTB, and DPP BovidTB tests. These results suggest that the Mycopar vaccine will interfere with diagnostic tools for paratuberculosis but result in low interference with the comparative cervical skin test and emerging serologic tests for
M. bovis
.
Macromolecular Assembly-Driven Processing of the 2/3 Cleavage Site in the Alphavirus Replicase Polyprotein
Authors: Lulla Aleksei , Lulla Valeria , Merits Andres 
Published: October 2011

ABSTRACT

Semliki Forest virus (SFV) is a member of the
Alphavirus
genus, which produces its replicase proteins in the form of a nonstructural (ns) polyprotein precursor P1234. The maturation of the replicase occurs in a temporally controlled manner by protease activity of nsP2. The template preference and enzymatic capabilities of the alphaviral replication complex have a very important connection with its composition, which is irreversibly altered by proteolysis. The final cleavage of the 2/3 site in the ns polyprotein apparently leads to significant rearrangements within the replication complex and thus denotes the “point of no return” for viral replication progression. Numerous studies have devised rules for when and how ns protease acts, but how the alphaviral 2/3 site is recognized remained largely unexplained. In contrast to the other two cleavage sites within the ns polyprotein, the 2/3 site evidently lacks primary sequence elements in the vicinity of the scissile bond sufficient for specific protease recognition. In this study, we sought to investigate the molecular details of the regulation of the 2/3 site processing in the SFV ns polyprotein. We present evidence that correct macromolecular assembly, presumably strengthened by exosite interactions rather than the functionality of the individual nsP2 protease, is the driving force for specific substrate targeting. We conclude that structural elements within the macrodomain of nsP3 are used for precise positioning of a substrate recognition sequence at the catalytic center of the protease and that this process is coordinated by the exact N-terminal end of nsP2, thus representing a unique regulation mechanism used by alphaviruses.
Mutational Mapping of pUL131A of Human Cytomegalovirus Emphasizes Its Central Role for Endothelial Cell Tropism
Authors: Schuessler Andrea , Sampaio Kerstin Laib , Straschewski Sarah , Sinzger Christian 
Published: October 2011

ABSTRACT
The UL131A protein is part of a pentameric variant of the gcIII complex in the virion envelope of human cytomegalovirus (HCMV), which has been found essential for efficient entry into endothelial cells (ECs). Using a systematic mutational scanning approach, we aimed to define peptide motifs within the UL131A protein that contribute to EC infection. Mutant viruses were generated in which charged amino acids within frames of 2 to 6 amino acids were replaced with alanines. The resulting viruses were evaluated with regard to their potential to infect EC cultures. Four clusters of charged amino acids essential for EC infection were identified (amino acids 22 to 27, 32 to 35, 64 to 69, and 116 to 121). Mutations of individual charge clusters within amino acids 72 to 104 caused minor reductions of EC tropism, but these effects were additive in a combined mutation, showing that this region also contributes to EC tropism. Only charge clusters within amino acids 46 to 58 were found irrelevant for EC infection. In conclusion, the unusual sensitivity to mutations, together with the remarkable conservation of the UL131A protein, emphasizes its particular role for EC tropism of HCMV.
Important but Differential Roles for Actin in Trafficking of Epstein-Barr Virus in B Cells and Epithelial Cells
Authors: Valencia Sarah M. , Hutt-Fletcher Lindsey M. 
Published: October 2011

ABSTRACTEpstein-Barr virus (EBV) uses different virus and cell proteins to enter its two major targets, B lymphocytes and epithelial cells. The routes that the virus takes into the two cell types are also different. To determine if these differences extend to movement from the cell surface to the nucleus, we examined the fate of incoming virus. Essentially all virus that entered a B cell remained stable for at least 8 h. In contrast, up to 80% of virus entering an epithelial cell was degraded in a compartment sensitive to inhibitors of components involved in autophagy. Inhibitors of actin remodeling blocked entry into a B cell but had no effect or enhanced entry into an epithelial cell. Inhibitors of the microtubule network reduced intracellular transport in both cell types, but movement to the nucleus in an epithelial cell also required involvement of the actin cytoskeleton. Deletion of the cytoplasmic tail of CR2, which in an epithelial cell interacts with the actin nucleator FHOS/FHOD when cross-linked by EBV, had no effect on infection. However, inhibitors of downstream signaling by integrins reduced intracellular transport. Cooperation of the microtubule and actin cytoskeletons, possibly activated by interaction with integrin binding proteins in the envelope of EBV, is needed for successful infection of an epithelial cell.
Pestivirus Virion Morphogenesis in the Absence of Uncleaved Nonstructural Protein 2-3
Authors: Lattwein E. , Klemens O. , Schwindt S. , Becher P. , Tautz N. 
Published: October 2011

ABSTRACTThe familyFlaviviridaecontains three genera of positive-strand RNA viruses, namely,Flavivirus,Hepacivirus(e.g., hepatitis C virus [HCV]), andPestivirus. Pestiviruses, like bovine viral diarrhea virus (BVDV), bear a striking degree of similarity to HCV concerning polyprotein organization, processing, and function. Along this line, in both systems, release of nonstructural protein 3 (NS3) is essential for viral RNA replication. However, both viruses differ significantly with respect to processing efficiency at the NS2/3 cleavage site and abundance as well as functional relevance of uncleaved NS2-3. In BVDV-infected cells, significant amounts of NS2-3 accumulate at late time points postinfection and play an essential but ill-defined role in the production of infectious virions. In contrast, complete cleavage of the HCV NS2-3 counterpart has been reported, and unprocessed NS2-3 is not required throughout the life cycle of HCV, at least in cell culture. Here we describe the selection and characterization of the first pestiviral genome with the capability to complete productive infection in the absence of uncleaved NS2-3. Despite the insertion of a ubiquitin gene or an internal ribosomal entry site between the NS2 and NS3 coding sequences, the selected chimeric BVDV-1 genomes gave rise to infectious virus progeny. In this context, a mutation in the N-terminal third of NS2 was identified as a critical determinant for efficient production of infectious virions in the absence of uncleaved NS2-3. These findings challenge a previously accepted dogma for pestivirus replication and provide new implications for virion morphogenesis of pestiviruses and HCV.
Ligand-Bound Structures of the Dengue Virus Protease Reveal the Active Conformation
Authors: Noble Christian G. , Seh Cheah Chen , Chao Alexander T. , Shi Pei Yong 
Published: October 2011

ABSTRACTDengue is a mosquito-borne viral hemorrhagic disease that is a major threat to human health in tropical and subtropical regions. Here we report crystal structures of a peptide covalently bound to dengue virus serotype 3 (DENV-3) protease as well as the serine-protease inhibitor aprotinin bound to the same enzyme. These structures reveal, for the first time, a catalytically active, closed conformation of the DENV protease. In the presence of the peptide, the DENV-3 protease forms the closed conformation in which the hydrophilic β-hairpin region of NS2B wraps around the NS3 protease core, in a manner analogous to the structure of West Nile virus (WNV) protease. Our results confirm that flavivirus proteases form the closed conformation during proteolysis, as previously proposed for WNV. The current DENV-3 protease structures reveal the detailed interactions at the P4′ to P3 sites of the substrate. The new structural information explains the sequence preference, particularly for long basic residues in the nonprime side, as well as the difference in substrate specificity between the WNV and DENV proteases at the prime side. Structural analysis of the DENV-3 protease-peptide complex revealed a pocket that is formed by residues from NS2B and NS3; this pocket also exists in the WNV NS2B/NS3 protease structure and could be targeted for potential antivirus development. The structural information presented in the current study is invaluable for the design of specific inhibitors of DENV protease.
The Lytic Phase of Epstein-Barr Virus Requires a Viral Genome with 5-Methylcytosine Residues in CpG Sites
Authors: Kalla Markus , Göbel Christine , Hammerschmidt Wolfgang 
Published: October 2011

ABSTRACT

Epstein-Barr virus (EBV) is a human herpesvirus which has been studied intensively for its role in certain human tumors. It also serves as a model of herpesviral latency because it establishes an immediate, latent infection in human B cells. When EBV infects quiescent, primary B cells it induces their continuous proliferation to yield growth-transformed B-cell lines
in vitro
. The lytic or productive phase of EBV's life cycle is induced by the expression of the viral
BZLF1
gene in latently infected cells. The BZLF1 protein is a transactivator, which selectively binds to two classes of distinct DNA sequence motifs. One class is similar to the motifs that are bound by members of the AP-1 transcription factor family to which BZLF1 belongs. The second class, which contains CpG motifs, is predominant in viral promoters of early lytic genes and is BZLF1's preferred or exclusive target sequence when methylated. The
BZLF1
gene is transiently expressed in newly infected B cells but fails to induce EBV's lytic cycle, potentially because the virion DNA is unmethylated. Here we report that the lack of 5-methylcytosine residues in CpG sites of virion DNA prevents the expression of essential lytic genes indispensable for viral DNA amplification during productive infection. This finding indicates that BZLF1 transactivates these promoters in a methylation-dependent fashion and explains how progeny virus synthesis is abrogated in newly infected B cells. Our data also reveal that viral lytic DNA synthesis precludes CpG methylation of virion DNA during EBV's lytic, productive cycle, which can be overcome by the ectopic expression of a prokaryotic cytosine methyltransferase to yield CpG-methylated virion DNA. Upon infection of B cells, randomly CpG-methylated virion DNA induces high expression of essential lytic genes in contrast to virion DNA free of 5-methylcytosine residues. Our data suggest that unmethylated virion DNA is part of EBV's strategy to prevent the viral lytic phase in newly infected B cells, allowing it to establish its characteristic latent infection in them.