bluuebunny/crossref_metadata_2025 huggingface dataset:
Type 6 Secretion System–Mediated Immunity to Type 4 Secretion System–Mediated Gene Transfer
Authors: Ho Brian T. , Basler Marek , Mekalanos John J.
Published: October 2013

Bacterial Détente?

Type VI secretion systems (T6SS) correspond to dynamic intracellular organelles that are functionally analogous to contractile bacteriophage tails. The T6SS of several bacteria species have been found to be responsible for antagonistic behavior that likely reflects the translocation of toxic proteins (effectors) between cells.
Pseudomonas aeruginosa
is able to sense exogenous T6SS attack and assemble its own T6SS apparatus to launch a retaliatory attack aimed directly at the attacker. Now,

Ho
et al.

(p.
250
) describe how exogenous attack is sensed in a process that involves membrane disruption and suggest that the T6SS provides a general cellular defense mechanism against not only T6SS but also conjugative DNA elements delivered via the type IV secretion system involved in mating pair formation.
Biology's Dry Future
Authors: Service Robert F.
Published: October 2013

The explosion of publicly available databases housing sequences, structures, and images allows life scientists to make fundamental discoveries without ever getting their hands "wet" at the lab bench.
LIFE SCIENCE TECHNOLOGIES: Exome Sequencing: Toward an Interpretable Genome
Authors: Perkel Jeffrey M.
Published: October 2013

The U.S. National Human Genome Research Institute says it can sequence genomes for $5,826 as of April 2013—just 0.006% of the $95.2 million per-genome price tag in September 2001. Commercial entities can do it for even less, and by the end of 2013, the cost could well dip below $1,000. Yet even at that low, low price, whole genome sequencing isn't cheap, at least not when researchers need to decode them by the thousands. Enter exome sequencing. Faster, cheaper, and more easily interpreted than its full-sized counterpart, an exome is to a genome as an abstract is to a research article: concise, information-rich, and easily digested.
Genetic Diversity of Newcastle Disease Virus in Wild Birds and Pigeons in West Africa
Authors: Snoeck Chantal J. , Adeyanju Adeniyi T. , Owoade Ademola A. , Couacy-Hymann Emmanuel , Alkali Bello R. , Ottosson Ulf , Muller Claude P.
Published: October 2013

In West and Central Africa, virulent Newcastle disease virus (NDV) strains of the recently identified genotypes XIV, XVII, and XVIII are enzootic in poultry, representing a considerable threat to the sector. The increasing number of reports of virulent strains in wild birds at least in other parts of the world raised the question of a potential role of wild birds in the spread of virulent NDV in sub-Saharan Africa as well. We investigated 1,723 asymptomatic birds sampled at live-bird markets and sites important for wild-bird conservation in Nigeria and 19 sick or dead wild birds in Côte d'Ivoire for NDV class I and II. Typical avirulent wild-type genotype I strains were found in wild waterfowl in wetlands in northeastern Nigeria. They were unrelated to vaccine strains, and the involvement of inter- or intracontinental migratory birds in their circulation in the region is suggested. Phylogenetic analyses also revealed that genotype VI strains found in pigeons, including some putative new subgenotype VIh and VIi strains, were introduced on multiple separate occasions in Nigeria. A single virulent genotype XVIII strain was found in a dead wild bird in Côte d'Ivoire, probably as a result of spillover from sick poultry. In conclusion, screening of wild birds and pigeons for NDV revealed the presence a variety of virulent and avirulent strains in West Africa but did not provide strong evidence that wild birds play an important role in the spread of virulent strains in the region.
Evaluation of a Prototype Flow Cytometry Test for Serodiagnosis of Canine Visceral Leishmaniasis
Authors: Ker Henrique Gama , Coura-Vital Wendel , Aguiar-Soares Rodrigo Dian de Oliveira , Roatt Bruno Mendes , das Dores Moreira Nádia , Carneiro Cláudia Martins , Machado Evandro Marques de Menezes , Teixeira-Carvalho Andréa , Martins-Filho Olindo Assis , Giunchetti Rodolfo Cordeiro , Araújo Márcio Sobreira Silva , Coelho Eduardo Antonio Ferraz , da Silveira-Lemos Denise , Reis Alexandre Barbosa
Published: October 2013

Diagnosing canine visceral leishmaniasis (CVL) is a critical challenge since conventional immunoserological tests still present some deficiencies. The current study evaluated a prototype flow cytometry serology test, using antigens and fluorescent antibodies that had been stored for 1 year at 4°C, on a broad range of serum samples. Noninfected control dogs and
Leishmania infantum
-infected dogs were tested, and the prototype test showed excellent performance in differentiating these groups with high sensitivity, specificity, positive and negative predictive values, and accuracy (100% in all analyses). When the CVL group was evaluated according to the dogs' clinical status, the prototype test showed outstanding accuracy in all groups with positive serology (asymptomatic II, oligosymptomatic, and symptomatic). However, in dogs which had positive results by PCR-restriction fragment length polymorphism (RFLP) but negative results by conventional serology (asymptomatic I), serological reactivity was not observed. Additionally, sera from 40 dogs immunized with different vaccines (Leishmune, Leish-Tec, or LBSap) did not present serological reactivity in the prototype test. Eighty-eight dogs infected with other pathogens (
Trypanosoma cruzi
,
Leishmania braziliensis
,
Ehrlichia canis
, and
Babesia canis
) were used to determine cross-reactivity and specificity, and the prototype test performed well, particularly in dogs infected with
B. canis
and
E. canis
(100% and 93.3% specificities, respectively). In conclusion, our data reinforce the potential of the prototype test for use as a commercial kit and highlight its outstanding performance even after storage for 1 year at 4°C. Moreover, the prototype test efficiently provided accurate CVL serodiagnosis with an absence of false-positive results in vaccinated dogs and minor cross-reactivity against other canine pathogens.
Consistency of Influenza A Virus Detection Test Results across Respiratory Specimen Collection Methods Using Real-Time Reverse Transcription-PCR
Authors: Spencer Sarah , Gaglani Manjusha , Naleway Allison , Reynolds Sue , Ball Sarah , Bozeman Sam , Henkle Emily , Meece Jennifer , Vandermause Mary , Clipper Lydia , Thompson Mark
Published: October 2013

In our prospective cohort study, we compared the performance of nasopharyngeal, oropharyngeal, and nasal swabs for the detection of influenza virus using real-time reverse transcription-PCR assay. Joint consideration of results from oropharyngeal and nasal swabs was as effective as consideration of results from nasopharyngeal swabs alone, as measured by sensitivity and noninferiority analysis.
Temporal and Spatial Compartmentalization of Drug-Resistant Cytomegalovirus (CMV) in a Child with CMV Meningoencephalitis: Implications for Sampling in Molecular Diagnosis
Authors: Frange Pierre , Boutolleau David , Leruez-Ville Marianne , Touzot Fabien , Cros Guilhem , Heritier Sebastien , Moshous Despina , Neven Benedicte , Fischer Alain , Blanche Stephane
Published: October 2013

We describe a case of antiviral-resistant cytomegalovirus meningoencephalitis occurring after hematopoietic stem cell transplantation. Antiviral-resistant cytomegalovirus was identified in blood 16 months earlier. However, wild-type cytomegalovirus was evidenced in blood when the meningoencephalitis was diagnosed. Treatment of meningoencephalitis should be adapted to all previously identified resistance mutations in any compartment.
A Chimeric Dengue Virus Vaccine using Japanese Encephalitis Virus Vaccine Strain SA14-14-2 as Backbone Is Immunogenic and Protective against Either Parental Virus in Mice and Nonhuman Primates
Authors: Li Xiao-Feng , Deng Yong-Qiang , Yang Hui-Qiang , Zhao Hui , Jiang Tao , Yu Xue-Dong , Li Shi-Hua , Ye Qing , Zhu Shun-Ya , Wang Hong-Jiang , Zhang Yu , Ma Jie , Yu Yong-Xin , Liu Zhong-Yu , Li Yu-Hua , Qin E-De , Shi Pei-Yong , Qin Cheng-Feng
Published: October 2013

The development of a safe and efficient dengue vaccine represents a global challenge in public health. Chimeric dengue viruses (DENV) based on an attenuated flavivirus have been well developed as vaccine candidates by using reverse genetics. In this study, based on the full-length infectious cDNA clone of the well-known Japanese encephalitis virus live vaccine strain SA14-14-2 as a backbone, a novel chimeric dengue virus (named ChinDENV) was rationally designed and constructed by replacement with the premembrane and envelope genes of dengue 2 virus. The recovered chimeric virus showed growth and plaque properties similar to those of the parental DENV in mammalian and mosquito cells. ChinDENV was highly attenuated in mice, and no viremia was induced in rhesus monkeys upon subcutaneous inoculation. ChinDENV retained its genetic stability and attenuation phenotype after serial 15 passages in cultured cells. A single immunization with various doses of ChinDENV elicited strong neutralizing antibodies in a dose-dependent manner. When vaccinated monkeys were challenged with wild-type DENV, all animals except one that received the lower dose were protected against the development of viremia. Furthermore, immunization with ChinDENV conferred efficient cross protection against lethal JEV challenge in mice in association with robust cellular immunity induced by the replicating nonstructural proteins. Taken together, the results of this preclinical study well demonstrate the great potential of ChinDENV for further development as a dengue vaccine candidate, and this kind of chimeric flavivirus based on JE vaccine virus represents a powerful tool to deliver foreign antigens.
Standard Trivalent Influenza Virus Protein Vaccination Does Not Prime Antibody-Dependent Cellular Cytotoxicity in Macaques
Authors: Jegaskanda Sinthujan , Amarasena Thakshila H. , Laurie Karen L. , Tan Hyon-Xhi , Butler Jeff , Parsons Matthew S. , Alcantara Sheilajen , Petravic Janka , Davenport Miles P. , Hurt Aeron C. , Reading Patrick C. , Kent Stephen J.
Published: October 2013

Yearly vaccination with the trivalent inactivated influenza vaccine (TIV) is recommended, since current vaccines induce little cross neutralization to divergent influenza strains. Whether the TIV can induce antibody-dependent cellular cytotoxicity (ADCC) responses that can cross-recognize divergent influenza virus strains is unknown. We immunized 6 influenza-naive pigtail macaques twice with the 2011–2012 season TIV and then challenged the macaques, along with 12 control macaques, serially with H1N1 and H3N2 viruses. We measured ADCC responses in plasma to a panel of H1 and H3 hemagglutinin (HA) proteins and influenza virus-specific CD8 T cell (CTL) responses using a sensitive major histocompatibility complex (MHC) tetramer reagent. The TIV was weakly immunogenic and, although binding antibodies were detected by enzyme-linked immunosorbent assay (ELISA), did not induce detectable influenza virus-specific ADCC or CTL responses. The H1N1 challenge elicited robust ADCC to both homologous and heterologous H1 HA proteins, but not influenza virus HA proteins from different subtypes (H2 to H7). There was no anamnestic influenza virus-specific ADCC or CTL response in vaccinated animals. The subsequent H3N2 challenge did not induce or boost ADCC either to H1 HA proteins or to divergent H3 proteins but did boost CTL responses. ADCC or CTL responses were not induced by TIV vaccination in influenza-naive macaques. There was a marked difference in the ability of infection compared to that of vaccination to induce cross-reactive ADCC and CTL responses. Improved vaccination strategies are needed to induce broad-based ADCC immunity to influenza.
Simian Foamy Virus Infection of Rhesus Macaques in Bangladesh: Relationship of Latent Proviruses and Transcriptionally Active Viruses
Authors: Soliven Khanh , Wang Xiaoxing , Small Christopher T. , Feeroz Mostafa M. , Lee Eun-Gyung , Craig Karen L. , Hasan Kamrul , Engel Gregory A. , Jones-Engel Lisa , Matsen Frederick A. , Linial Maxine L.
Published: October 2013

Simian foamy viruses (SFV) are complex retroviruses that are ubiquitous in nonhuman primates (NHP) and are zoonotically transmitted to humans, presumably through NHP saliva, by licking, biting, and other behaviors. We have studied SFV in free-ranging rhesus macaques in Bangladesh. It has been previously shown that SFV in immunocompetent animals replicates to detectable levels only in superficial epithelial cells of the oral mucosa, although latent proviruses are found in most, if not all, tissues. In this study, we compare DNA sequences from latent SFV proviruses found in blood cells of 30 Bangladesh rhesus macaques to RNA sequences of transcriptionally active SFV from buccal swabs obtained from the same animals. Viral strains, defined by differences in SFV
gag
sequences, from buccal mucosal specimens overlapped with those from blood samples in 90% of animals. Thus, latent proviruses in peripheral blood mononuclear cells (PBMC) are, to a great extent, representative of viruses likely to be transmitted to other hosts. The level of SFV RNA in buccal swabs varied greatly between macaques, with increasing amounts of viral RNA in older animals. Evidence of APOBEC3-induced mutations was found in
gag
sequences derived from the blood and oral mucosa.
Truncation and Sequence Shuffling of Segment 6 Generate Replication-Competent Neuraminidase-Negative Influenza H5N1 Viruses
Authors: Kalthoff Donata , Röhrs Susanne , Höper Dirk , Hoffmann Bernd , Bogs Jessica , Stech Jürgen , Beer Martin
Published: October 2013

Influenza viruses are highly genetically variable and escape from immunogenic pressure by antigenic changes in their surface proteins, referred to as “antigenic drift” and “antigenic shift.” To assess the potential genetic plasticity under strong selection pressure, highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 was passaged 50 times in embryonated chicken eggs in the presence of a neutralizing, polyclonal chicken serum. The resulting mutant acquired major alterations in the neuraminidase (NA)-encoding segment. Extensive deletions and rearrangements were detected, in contrast to only 12 amino acid substitutions within all other segments. Interestingly, this new neuraminidase segment resulted from complex sequence shuffling and insertion of a short fragment originating from the PA segment. Characterization of that novel variant revealed a loss of the neuraminidase protein and enzymatic activity, but its replication efficiency remained comparable to that of the wild type. Using reverse genetics, a recombinant virus consisting of the wild-type backbone and the shortened NA segment could be generated; however, generation of this recombinant virus required the polybasic hemagglutinin cleavage site. Two independent repetitions starting with egg passage 30 in the presence of alternative chicken-derived immune sera selected mutants with similar but different large deletions within the NA segment without any neuraminidase activity, indicating a general mechanism. In chicken, these virus variants were avirulent, even though the HPAIV polybasic hemagglutinin cleavage site was still present. Overall, the variants reported here are the first HPAIV H5N1 strains without a functional neuraminidase shown to grow efficiently without any helper factor. These novel HPAIV variants may facilitate future studies shedding light on the role of neuraminidase in virus replication and pathogenicity.
Next-Generation Sequence Analysis of the Genome of RFHVMn, the Macaque Homolog of Kaposi's Sarcoma (KS)-Associated Herpesvirus, from a KS-Like Tumor of a Pig-Tailed Macaque
Authors: Bruce A. Gregory , Ryan Jonathan T. , Thomas Mathew J. , Peng Xinxia , Grundhoff Adam , Tsai Che-Chung , Rose Timothy M.
Published: October 2013

The complete sequence of retroperitoneal fibromatosis-associated herpesvirus
Macaca nemestrina
(RFHVMn), the pig-tailed macaque homolog of Kaposi's sarcoma-associated herpesvirus (KSHV), was determined by next-generation sequence analysis of a Kaposi's sarcoma (KS)-like macaque tumor. Colinearity of genes was observed with the KSHV genome, and the core herpesvirus genes had strong sequence homology to the corresponding KSHV genes. RFHVMn lacked homologs of open reading frame 11 (ORF11) and KSHV ORFs K5 and K6, which appear to have been generated by duplication of ORFs K3 and K4 after the divergence of KSHV and RFHV. RFHVMn contained positional homologs of all other unique KSHV genes, although some showed limited sequence similarity. RFHVMn contained a number of candidate microRNA genes. Although there was little sequence similarity with KSHV microRNAs, one candidate contained the same seed sequence as the positional homolog, kshv-miR-K12-10a, suggesting functional overlap. RNA transcript splicing was highly conserved between RFHVMn and KSHV, and strong sequence conservation was noted in specific promoters and putative origins of replication, predicting important functional similarities. Sequence comparisons indicated that RFHVMn and KSHV developed in long-term synchrony with the evolution of their hosts, and both viruses phylogenetically group within the RV1 lineage of Old World primate rhadinoviruses. RFHVMn is the closest homolog of KSHV to be completely sequenced and the first sequenced RV1 rhadinovirus homolog of KSHV from a nonhuman Old World primate. The strong genetic and sequence similarity between RFHVMn and KSHV, coupled with similarities in biology and pathology, demonstrate that RFHVMn infection in macaques offers an important and relevant model for the study of KSHV in humans.
CpG Dinucleotide Frequencies Reveal the Role of Host Methylation Capabilities in Parvovirus Evolution
Authors: Upadhyay Mohita , Samal Jasmine , Kandpal Manish , Vasaikar Suhas , Biswas Banhi , Gomes James , Vivekanandan Perumal
Published: October 2013

Parvoviruses are rapidly evolving viruses that infect a wide range of hosts, including vertebrates and invertebrates. Extensive methylation of the parvovirus genome has been recently demonstrated. A global pattern of methylation of CpG dinucleotides is seen in vertebrate genomes, compared to “fractional” methylation patterns in invertebrate genomes. It remains unknown if the loss of CpG dinucleotides occurs in all viruses of a given DNA virus family that infect host species spanning across vertebrates and invertebrates. We investigated the link between the extent of CpG dinucleotide depletion among autonomous parvoviruses and the evolutionary lineage of the infected host. We demonstrate major differences in the relative abundance of CpG dinucleotides among autonomous parvoviruses which share similar genome organization and common ancestry, depending on the infected host species. Parvoviruses infecting vertebrate hosts had significantly lower relative abundance of CpG dinucleotides than parvoviruses infecting invertebrate hosts. The strong correlation of CpG dinucleotide depletion with the gain in TpG/CpA dinucleotides and the loss of TpA dinucleotides among parvoviruses suggests a major role for CpG methylation in the evolution of parvoviruses. Our data present evidence that links the relative abundance of CpG dinucleotides in parvoviruses to the methylation capabilities of the infected host. In sum, our findings support a novel perspective of host-driven evolution among autonomous parvoviruses.
The Nuclear-Cytoplasmic Shuttling of Virion Host Shutoff RNase Is Enabled by pU
L
47 and an Embedded Nuclear Export Signal and Defines the Sites of Degradation of AU-Rich and Stable Cellular mRNAs
Authors: Shu Minfeng , Taddeo Brunella , Roizman Bernard
Published: October 2013

The herpes simplex virus host shutoff RNase (VHS-RNase) is the major early block of host responses to infection. VHS-RNase is introduced into cells during infection and selectively degrades stable mRNAs made before infection and the normally short-lived AU-rich stress response mRNAs induced by sensors of innate immunity. Through its interactions with pU
L
47, another tegument protein, it spares from degradation viral mRNAs. Analyses of embedded motifs revealed that VHS-RNase contains a nuclear export signal (NES) but not a nuclear localization signal. To reconcile the potential nuclear localization with earlier studies showing that VHS-RNase degrades mRNAs in polyribosomes, we constructed a mutant in which NES was ablated. Comparison of the mutant and wild-type VHS-RNases revealed the following. (i) On infection, VHS-RNase is transported to the nucleus, but only the wild-type protein shuttles between the nucleus and cytoplasm. (ii) Both VHS-RNases localized in the cytoplasm following transfection. On cotransfection with pU
L
47, a fraction of VHS-RNase was translocated to the nucleus, suggesting that pU
L
47 may enable nuclear localization of VHS-RNase. (iii) In infected cells, VHS-RNase lacking NES degraded the short-lived AU-rich mRNAs but not the stable mRNAs. In transfected cells, both wild-type and NES mutant VHS-RNases effectively degraded cellular mRNAs. Our results suggest that the stable mRNAs are degraded in the cytoplasm, whereas the AU-rich mRNAs may be degraded in both cellular compartments. The selective sparing of viral mRNAs may take place during the nuclear phase in the course of interaction of pU
L
47, VHS-RNase, and nascent viral mRNAs.
Cardiac energy metabolism is positively associated with skeletal muscle energy metabolism in physically active adolescents and young adults
Authors: Banks Laura , Wells Greg D. , McCrindle Brian W.
Published: October 2013

31Phosphorus Magnetic Resonance Spectroscopy (31P MRS) is a well-validated, noninvasive magnetic resonance imaging technique that has been used to determine cardiac and skeletal muscle energy metabolism in vivo. Few studies have documented cardiac energy metabolism in adolescents and young adult cohorts. This cross-sectional study sought to explore the association among cardiac energy metabolism, skeletal muscle energy metabolism, moderate-to-vigorous physical activity (MVPA), and age in adolescents and young adults. Ten healthy, active participants (40% male) with a mean ± SD age of 18.6 ± 4.9 years, body mass index of 21.1 ± 2.4 kg·m−2, and median MVPA level of 83 min per weekday (lower quartile: 45 min per weekday; upper quartile: 114 min per weekday) completed the following study assessments: a 31P MRS scan to determine cardiac and skeletal muscle energy metabolism, cardiopulmonary exercise testing to determine aerobic power, and accelerometry to determine MVPA over 7 days. Resting cardiac energy metabolism, as measured by the ratio of phosphocreatine to adenosine triphosphate (PCr/ATPβ, mean ± SD: 2.76 ± 0.65), was positively associated with skeletal muscle aerobic oxidative function (Estimate (SE): −0.1(0.01), p < 0.001), as measured by PCr recovery half-time following 60 s of exercise (34 ± 9 s). This association, which was adjusted for peak aerobic power, MVPA, age, and sex, suggests the development of an association between cardiac and skeletal muscle health at any early age. Larger studies are needed to establish normative data for both physically active and sedentary males and females that may be used for comparison in future studies involving clinical cohorts.
Hybridization inPopulusalters the species composition and interactions of root-colonizing fungi: consequences for host plant performance
Authors: Gehring Catherine A. , Ji Baoming , Fong Sarah , Whitham Thomas G.
Published: October 2013

Interactions among plants and soil microbes can significantly influence plant communities, yet we understand little about how hybridization of plant species might alter these interactions. In addition, few studies have explored the effects of different components of soil microbial communities on plant performance. We tested for feedbacks between soil microbes within a Populus hybridizing system using approaches that allowed us to isolate the effects of arbuscular mycorrhizal fungi (AMF) and root endophytes. We found significant differences among the arbuscular mycorrhizal (AM) fungal spore communities cultured from Populus angustifolia James, Populus fremontii S. Watson, and their F1hybrids. Populus angustifolia cuttings grew 40% larger when inoculated with AM fungal spores from F1hybrids than with spores from P. fremontii, while growth with spores from P. angustifolia was intermediate. However, parental and hybrid inocula promoted growth equally when soil inoculum was used. Roots inoculated with AM fungal spores alone were colonized principally by AMF, while those inoculated with soil were colonized mostly by dark septate endophytes. These results indicate that genetic variation among hybridizing plant species can influence both microbial communities and their interactions with host plants, but these effects depend upon the type of microbe. Furthermore, our results suggest that interactions among fungi during root colonization may alter the composition and function of the plant microbiome.
Can quantum control modify thermodynamic behavior?
Authors: Gelbwaser-Klimovsky D. , Erez N. , Alicki R. , Kurizki G.
Published: October 2013

We review the effects of frequent, impulsive quantum nondemolition measurements of the energy of two-level systems, alias qubits, in contact with a thermal bath. The resulting entropy and temperature of the system subject to measurements at intervals below the bath memory (Markovianity) time are completely determined by the measurement rate. Namely, they are unrelated to what is expected by standard thermodynamical behavior that holds for Markovian baths. These anomalies allow for very fast control of heating, cooling, and state-purification (entropy reduction) of qubits, much sooner than their thermal equilibration time. We further show that frequent measurements may enable the extraction of work in a closed cycle from the system−bath interaction (correlation) energy, a hitherto unexploited work resource. They allow for work even if no information is gathered or the bath is at zero temperature, provided the cycle is within the bath memory time.
Fluorofenidone attenuates vascular remodeling in hypoxia-induced pulmonary hypertension of rats
Authors: Li Xian-Wei , Du Jie , Hu Gao-Yun , Hu Chang-Ping , Li Dai , Li Yuan-Jian , Li Xiao-Hui
Published: October 2013

Fluorofenidone (AKF-PD) is a novel pyridone derivate that targets transforming growth factor-β1(TGF-β1) signaling. Previous studies have proven that AKF-PD functions as an antifibrotic agent in pulmonary fibrosis and renal fibrosis models. Activated TGF-β1signaling is thought to be a major feature of pulmonary hypertension (PH). TGF-β1exerts powerful pro-proliferation effects on pulmonary arterial smooth muscle cells (PASMCs), and hence, prompts vascular remodeling. This study is designed to investigate the effect of AKF-PD on vascular remodeling in a rat model of hypoxia-induced PH. PH was induced in rats by 4 weeks of hypoxia. The expression of TGF-β1, collagen I, and collagen III was analyzed by ELISA, immunohistochemistry, real-time PCR, or Western blot. Proliferation of cultured PASMCs was determined by the BrdU incorporation method and flow cytometry. The results showed that AKF-PD treatment (0.5 or 1.0 g·(kg body mass)·d−1) for 4 weeks attenuated pulmonary vascular remodeling and improved homodynamic parameters. TGF-β1level was significantly down-regulated by AKF-PD both in vivo and in vitro. Furthermore, hypoxia- and TGF-β1-induced PASMC proliferation and collagen expression were both significantly suppressed by AKF-PD. These results suggest that AKF-PD ameliorates the progression of PH induced by hypoxia in rats through its regulation of TGF-β1expression, PASMC proliferation, and the extracellular matrix.
RIEMANN ZETA ZEROS AND PRIME NUMBER SPECTRA IN QUANTUM FIELD THEORY
Authors: MENEZES G. , SVAITER B. F. , SVAITER N. F.
Published: October 2013

The Riemann hypothesis states that all nontrivial zeros of the zeta function lie in the critical line Re (s) = 1/2. Hilbert and Pólya suggested that one possible way to prove the Riemann hypothesis is to interpret the nontrivial zeros in the light of spectral theory. Using the construction of the so-called super-zeta functions or secondary zeta functions built over the Riemann nontrivial zeros and the regularity property of one of this function at the origin, we show that it is possible to extend the Hilbert–Pólya conjecture to systems with countably infinite number of degrees of freedom. The sequence of the nontrivial zeros of the Riemann zeta function can be interpreted as the spectrum of a self-adjoint operator of some hypothetical system described by the functional approach to quantum field theory. However, if one considers the same situation with numerical sequences whose asymptotic distributions are not "far away" from the asymptotic distribution of prime numbers, the associated functional integral cannot be constructed. Finally, we discuss possible relations between the asymptotic behavior of a sequence and the analytic domain of the associated zeta function.
ANTIPARTICLES CREATION IN TUNNELING
Authors: DE LEO STEFANO , ROTELLI PIETRO
Published: October 2013

We study particle interaction with a Dirac step potential. In the standard Klein energy zone, the hypothesis of Klein pair production predicts the existence of free/oscillatory antiparticles. In this paper, we discuss the tunneling energy zone characterized by evanescent wave functions in the classically forbidden region. We ask the question of the nature, particle or antiparticle, of the densities within the classically forbidden region. The answer to this question is relevant to the correct form of the reflection coefficient.
CHAOS IN COMPUTING THE ENVIRONMENTAL INTERFACE TEMPERATURE: NONLINEAR DYNAMIC AND COMPLEXITY ANALYSIS OF SOLUTIONS
Authors: MIMIĆ GORDAN , MIHAILOVIĆ DRAGUTIN T. , BUDINČEVIĆ MIRKO
Published: October 2013

In this paper, we consider an environmental interface as a complex system, in which difference equations for calculating the environmental interface temperature and deeper soil layer temperature are represented by the coupled maps. First equation has its background in the energy balance equation while the second one in the prognostic equation for deeper soil layer temperature, commonly used in land surface parametrization schemes. Nonlinear dynamical consideration of this coupled system includes: (i) examination of period one fixed point and (ii) bifurcation analysis. Focusing part of analysis is calculation of the Lyapunov exponent for a specific range of values of system parameters and discussion about domain of stability for this coupled system. Finally, we calculate Kolmogorov complexity of time series generated from the coupled system.
Geology and U–Pb geochronology of the Espedalen Complex, southern Norway, and its position in the Caledonian nappe systems
Authors: Corfu F. , Heim M.
Published: October 2013

The Espedalen Nappe is located in the east of the Jotun–Valdres Nappe Complex in southern Norway. Its main component, the Espedalen Complex, consists of an early suite of jotunite, charnockite and augengneiss, a main anorthosite–ultramafite–norite suite, and a late gabbronorite suite. Mafic dykes and lamprophyres cut the complex, some being feeders to the Stylskampen mafic to felsic suite at the western margin of the complex. The complex hosts Ni–Cu mineralizations which were mined in past centuries. Two crystalline outliers occur at Ormtjernkampen and Røssjøkollen further south. Caledonian convergence thrust the nappe on to Early Palaeozoic sedimentary rocks. Rocks of the Espedalen Complex are covered and/or tectonically interleaved with Late Precambrian conglomerates and arkoses of the Valdres Group. Dating of zircon and titanite by ID-TIMS U–Pb indicates formation of the complex at 1520–1510 Ma, followed by deformation and metamorphism between 1050 and 950 Ma during the Sveconorwegian orogeny, before the eventual translation during the Caledonian orogeny. These data indicate an affinity of the nappe with Telemarkian crust in the autochthonous Baltic basement, in contrast to the rocks of the overlying Jotun Complex which correlate instead to Gothian crust formed between 1600 and 1700 Ma.
Oxygen Evolution Reaction for Ta Compound Films Prepared by Reaction Sputtering with Resintering
Authors: Matsuzawa Koichi , Goto Keisuke , Takahashi Kenichi , Kohno Yuji , Ota Ken-ichiro , Mitsushima Shigenori
Published: October 2013

In order to improve catalytic activity for oxygen evolution reaction, we have investigated effect of resintering under vacuum at high temperature on activities of tantrum compound film prepared by reactive sputtering. As a result, the tantrum compound film which was prepared with resintering process during formation of film was larger surface area than that without resintering after sputttering. The tantrum compound film with resintering was also improved for specific catalytic activity than that without resintering after sputtering for the oxygen evolution reaction.
Hydrogen Generation by Electrocatalyic Reforming of Biomass-Related Compounds: Ethylene Glycol
Authors: Stuve Eric M. , Spies Kurt
Published: October 2013

Electrocatalytic reforming (ECR) of ethylene glycol (EG) was studied in an effort to determine the feasibility of ECR for hydrogen production from biomass. Measurements were made in a proton exchange membrane (PEM) reactor with Pt/C anode and cathode and Nafion electrolyte. Electrooxidation of EG in aqueous phase was studied over the temperature range of 40--137 °C. Reaction progress was followed by cyclic voltammetry, potential-step chronoamperometry, and chromatographic analysis of reaction products. Sustained reaction occurred at an overpotential as low as 0.49 V at 137 °C. A variety of partial oxidation products were observed; glycolaldehyde, glycolic acid, and traces of oxalic acid; mostly at low temperatures. The results were interpreted according to the dual pathways mechanism, in which path A involves a series reaction through a CO
ads
intermediate, and path B is parallel route to CO2 that bypasses CO
ads
. Activation energies of 18 and 43 kJ/mol were measured for EG conversion and CO2 production. The lower value is attributed to formation of partial oxidation products, and the higher value to CO
ads
electrooxidation in path A. The sustained reaction at low overpotential along with near complete oxidation, both of which occur at high temperature, show that ECR can be a viable process in biomass reforming, and that further studies must be conducted at higher temperatures for a more complete understanding of this process.
Enhanced Photoelectrochemical Activity of GaN by Dry Etching into Nanopillar Array
Authors: Tseng Wei-Jhih , Mehta Bharat , Dorp Dennis H. van , Lieten Ruben R. , Vereecken Philippe M. , Borghs Gustaaf
Published: October 2013

GaN nanopillar arrays are fabricated by inductively-coupled-plasma dry etching of a GaN epitaxial layer, using self-assembled Ni clusters as mask. Pillars of 0.4-1.6 μm height were prepared and were investigated photoelectrochemically. After the roughening, the surface area increases up to 6 times and the plateau photocurrent increases by 84% with respect to the planar GaN. The enlarged GaN/electrolyte interface promotes charge transfer and photocarrier separation in the pillar array. The defect-mediated carrier recombination becomes more important after the dry etching process. The impact of surface damage is studied by the photoelectrochemical and photoluminescence measurements.
An Electrochemical Method for the Production of Graphite Oxide
Authors: Parker Andrew James , Dickinson James William , Boxall Colin , Joyce Malcolm J
Published: October 2013

We report on the development of a technique for the rapid production of exfoliated graphite oxide, using an electrochemical oxidation and exfoliation method. Vitreous carbon foam (VCF) sheets were utilised as the anode in an electrolytic cell. VCF anodes were oxidized under a maximum applied electric field of 60V and a current of 2A in NaOH electrolyte solutions. The resulting solids, collected after separation of the electrolyte, were analysed using ultraviolet-visible spectroscopy, X-ray diffraction and scanning electron microscopy. The preliminary analysis shows that the solids collected were comprised of graphite oxide and partially reduced graphite oxide platelets. Quartz substrates coated in partially reduced graphite oxide solutions were thermally annealed to produce conductive layers.
Non-Enzymatic Glucose Oxidation at Electrocatalytic Metal Oxide Films
Authors: Doyle Richard L. , Komarkova Gabriela , O'Brien Patrick , Lyons Michael E.G.
Published: October 2013

The electro-oxidation of glucose at nickel hydroxide films is discussed. These films can be electrodeposited using a simple potential multi-cycling procedure. The resulting films exhibit a nanostructured surface morphology. Cyclic voltammetry, rotating-disk electrode voltammetry and electrochemical impedance spectroscopy have been used to elucidate the kinetics and mechanism of the oxidation of glucose. NiOOH is shown to be the active form of the nickel hydroxide layer and the impedance data indicates significant surface adsorption at these sites. Furthermore, mass-transport-corrected Tafel slopes of ca. 40 and 60 mV/dec were observed at low and high potentials respectively identifying a change in rate-control with increasing potential. Finally, we show using amperometric techniques that this simple modified electrode possesses excellent sensitivity for the oxidation of glucose, displaying current increases of ca. 3.7 mA mM−1 cm−2 with a limit of detection of the order of 2.0 μM glucose.
The Electrochemical Approach towards Proton Coupled Electron Transfer Pathways for Oxidation of Thymine in Water
Authors: Soomro Muhammad Tahir , Grampp Guenter , Nguyen Truong Xuan , Ismail Iqbal Mohammad
Published: October 2013

The work describes the use of cyclic voltammetry to investigate the proton coupled electron transfer (PCET) pathways for oxidation of thymine in water. Biologically important compounds like DNA bases, and amino acids showed irreversible behavior when oxidized electrochemically. The reversible redox potentials for such systems (say, irreversible electrochcemical systems) were estimated by analyzing the cyclic voltammograms recorded at different scan rates. The approach presents here is relatively simple and easy for obtaining reversible redox potential of electrochemically irreversible systems. Moreover, for the case of thymine, the obtained reversible oxidation potential also used to establish the PCET-pathways for oxidation of thymine in water.
Adsorption Study of Metal Ions on Electrochemically Synthesized Poly-(ortho-phenylenediamine)
Authors: Etorki Abdunnaser Mohmed , El Rais Mahmoud abdellsamed
Published: October 2013

The present work deals with the study of uptake behaviour of Cd(II), Pb(II), and Zn(II) ions by Electrochemically synthesized Poly-(ortho-phenylenediamine) (POPD) using batch equilibration technique with both single and binary mixtures. The effect of the various parameters such as electrochemically synthesis method, physical oxidation state of the polymer, polymer thickness, solution pH and metal ion concentration on the adsorption, kinetics and efficiency were investigated. The results showed avary broad concentration range of the metal ions from (0.2 to 20 mg/L) can be adsorbed on the polymer at pH = 6.6 (efficiently >98%). The adsorption capacity of the polymer to different concentrations of metal ions was evaluated as the milligram of metal ions by one gram of various forms of the polymer. The DC conductivity measurements were also employed on the solid polymer before and after adsorption of metal ions. The experimental adsorption date was fitted to different mathematical isotherms to estimate the binding constant of metal ions with the polymer in both single and mixed ion solutions.
Electrode Performance of Newly Developed Ni-W-S Deposited Alloy for Alkaline Water Electrolysis
Authors: Yoshihara Sachio , Suzuki Daisuke , Someya Kouji , Kikuchi Takanori , Ishikawa Yoshifusa
Published: October 2013

Ni-W-S coatings were fabricated by electroplating. The bath denoted as “Ni-W-S No.1” was derived from a neutral pH bath for Ni-W alloy plating. Furthermore, sulfosalicylic acid was added as a stress reducer in order to prevent surface cracks. In the solution denoted as “Ni-W-S No.2” contains sodium tungstate, as a source of tungsten, sodium citrate. Plating solution denoted as “Ni-S” is same bath with Ni-W-S No.2 without sodium tungstate. Ni-W-S electrodes showed significantly excellent characteristics as a cathode for alkaline water electrolysis. Specifically, the Ni-W-S electrode in which sulfosalicylic acid was added as a stress reducer exhibited an excellent performance comparing to conventional Ni-S and Ni cathode. In order to obtain the performances of thus obtained electrode for alkaline water electrolysis, an electrode surface morphology was observed by SEM and the film composition was evaluated by EDX. In order to specify the crystal structure, XRD was employed. Furthermore, in order to evaluate the durability performance as a cathode for water electrolysis, sequential changes in electrode performance was investigated periodically using LSV while performing long-term electrolysis test for 48 hours. Furthermore the prevention of sulfur dissolution during cathodic polarization was monitored.
Cyclic Voltammetry Study of Anodic and Cathodic Reactions on Graphite in Cryolite- Silica Melt
Authors: Sokhanvaran Samira , Barati Mansoor
Published: October 2013

Electrodeposition of Si from cryolite based melts is a possible solution for mass production of solar grade silicon. The deposition potential of Si on the candidate cathode, such as graphite, is fundamental information that needs to be measured and applied to restrict the co–deposition of impurities. In this study this potential was measured using cyclic voltammetry. As the activity of SiO2 in the electrolyte affects the deposition potential, the measurement was carried out in a range of SiO2 concentration, allowing the prediction of potential change during the actual deposition process, where the SiO2 content undergoes fluctuations. The kinetics of the oxidation and reduction reactions were also studied using the recorded voltammograms, showing that reduction of Si is a two steps process controlled by diffusion.
Electrodeposition of Niobium on Magnesium Using Green Ionic Liquids
Authors: Mahapatro Anil , Hakim Jehanzeb , Crane Justen B , Senthil Kumar Siddarth
Published: October 2013

In recent years magnesium (Mg) and its alloys are being increasingly investigated as alternatives to iron and aluminum to reduce the weight of structural materials in automotive applications. Relatively poor corrosion resistance of Mg has severely limited the growth of magnesium in automobiles. Coatings via electro-deposition can protect magnesium and its alloys from corroding but challenges associated with this technology are in the use of toxic chemicals such as chromium, cyanide, fluoride and corrosive acid based pretreatment and bath solutions. In this manuscript we report the electro-deposition of niobium on magnesium using green ionic liquids. The SEM-EDS elemental analysis confirmed the deposition of niobium on magnesium alloy. Optimization of process parameters are needed to obtain a stress and pore free coating.
Hormonal regulation of salt and water excretion: a mathematical model of whole kidney function and pressure natriuresis
Authors: Moss Robert , Thomas S. Randall
Published: October 2013

We present a lumped-nephron model that explicitly represents the main features of the underlying physiology, incorporating the major hormonal regulatory effects on both tubular and vascular function, and that accurately simulates hormonal regulation of renal salt and water excretion. This is the first model to explicitly couple glomerulovascular and medullary dynamics, and it is much more detailed in structure than existing whole organ models and renal portions of multiorgan models. In contrast to previous medullary models, which have only considered the antidiuretic state, our model is able to regulate water and sodium excretion over a variety of experimental conditions in good agreement with data from experimental studies of the rat. Since the properties of the vasculature and epithelia are explicitly represented, they can be altered to simulate pathophysiological conditions and pharmacological interventions. The model serves as an appropriate starting point for simulations of physiological, pathophysiological, and pharmacological renal conditions and for exploring the relationship between the extrarenal environment and renal excretory function in physiological and pathophysiological contexts.
Petri Net-Based R&D Process Modeling and Optimization for Composite Materials
Authors: Hu Xiaomei , Zhao Lei , Li Wenlong
Published: October 2013

Considering the current R&D process for new composite materials involves some complex details, such as formula design, specimen/sample production, materials/sample test, assessment, materials/sample feedback from customers, and mass production, the workflow model of Petri net-based R&D process for new composite materials’ is proposed. By analyzing the time property of the whole Petri net, the optimized model for new composite materials R&D workflow is further proposed. By analyzing the experiment data and application in some materials R&D enterprise, it is demonstrated that the workflow optimization model shortens the period of R&D on new materials for 15%, definitely improving the R&D efficiency. This indicates the feasibility and availability of the model.
ERK1/2 Blockade Prevents Epithelial–Mesenchymal Transition in Lung Cancer Cells and Promotes Their Sensitivity to EGFR Inhibition
Authors: Buonato Janine M. , Lazzara Matthew J.
Published: October 2013

Overcoming cellular mechanisms of de novo and acquired resistance to drug therapy remains a central challenge in the clinical management of many cancers, including non–small cell lung cancer (NSCLC). Although much work has linked the epithelial–mesenchymal transition (EMT) in cancer cells to the emergence of drug resistance, it is less clear where tractable routes may exist to reverse or inhibit EMT as a strategy for drug sensitization. Here, we demonstrate that extracellular signal-regulated kinase (ERK) 1/2 (mitogen-activated protein kinase 3/1, MAPK3/1) signaling plays a key role in directing the mesenchymal character of NSCLC cells and that blocking ERK signaling is sufficient to heighten therapeutic responses to EGF receptor (EGFR) inhibitors. MEK1/2 (MAPKK1/2) inhibition promoted an epithelial phenotype in NSCLC cells, preventing induction of EMT by exogenous TGF-β. Moreover, in cells exhibiting de novo or acquired resistance to the EGFR inhibitor gefitinib, MEK inhibition enhanced the sensitivity to gefitinib and slowed cell migration. These effects only occurred, however, if MEK was inhibited for a period sufficient to trigger changes in EMT marker expression. Consistent with these findings, changes in EMT phenotypes and markers were also induced by the expression of mutant KRAS in a MEK-dependent manner. Our results suggest that prolonged exposure to MEK or ERK inhibitors may not only restrain EMT but also overcome naïve or acquired resistance of NSCLC to EGFR-targeted therapy in the clinic. Cancer Res; 74(1); 309–19. ©2013 AACR.