bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of Serology Assays for Diagnosing Celiac Disease in a Clinical Setting
Authors: Parizade Miriam , Bujanover Yoram , Weiss Batya , Nachmias Vered , Shainberg Bracha
Published: September 2009

Diagnosis of celiac disease frequently depends upon serology assays. We set out to prospectively assess the diagnostic value of five serology tests: an enzyme-linked immunosorbent assay (ELISA) for tissue transglutaminase (tTG)-immunoglobulin A (IgA) and tTG-IgG, a chemiluminescence assay for tTG-IgA, an ELISA for deamidated gliadin peptide (DGP) IgG and IgA screening, and detection of endomysial antibodies (Abs) by indirect immunofluorescence. One hundred sixteen children at high risk for developing celiac disease were evaluated clinically and underwent small bowel biopsies and blood serology tests. We examined differences between younger and older children in terms of clinical presentation, test performance, and the ability of high Ab levels to correctly predict diagnosis of celiac disease. Celiac disease was diagnosed for 85 (73%) children. No significant clinical differences were observed between the biopsy-positive and biopsy-negative groups. Children ≤3 years of age revealed higher concentrations of tTG-IgA and DGP Abs than children >3 years old (
P
= 0.017 and 0.007, respectively). High Ab concentrations were predictive of villous atrophies, with sensitivities ranging from 92.8% to 97.9%, depending on the assay and the cutoff points applied. Sensitivities, specificities, positive predictive values, and negative predictive values varied among assays and improved after correction for best cutoff points. Assay specificities obtained in the clinical setting were lower than expected. The new tTG-IgA chemiluminescence assay demonstrated high throughput but low specificity (74.2%). The tTG-IgA ELISA exhibited the highest test efficiency, and the tTG-IgA chemiluminescence assay was suitable for large-scale screening, with reduced specificity. High concentrations of celiac disease-specific Abs bring into question the need for performance of biopsies on children at high risk.
Vaccination with LiveLeishmania majorand CpG DNA Promotes Interleukin-2 Production by Dermal Dendritic Cells and NK Cell Activation
Authors: Laabs Eva Maria , Wu Wenhui , Mendez Susana
Published: September 2009

Cutaneous leishmaniasis due toLeishmania majoris an emerging, chronic parasitic disease that causes disfigurement and social stigmatization. Drug therapy is inadequate, and there is no vaccine. Inoculation of virulent parasites (leishmanization) is the only intervention that has ever provided protection, because it mimics natural infection and immunity, but it was discontinued due to safety concerns (uncontrolled vaccinal lesions). In an effort to retain the benefits (immunity) while avoiding the side effects (lesions) of leishmanization, we immunized C57BL/6 mice withL. majorand CpG DNA (Lm/CpG). This combination prevented lesions while inducing immunity. Also, the vaccination with live parasites and the Toll-like receptor 9 agonist enhanced innate immune responses by activating dermal dendritic cells (DCs) to produce cytokines. Here we report that the Lm/CpG vaccine induced dermal DCs, but not bone marrow-derived DCs, to produce interleukin-2 (IL-2). The release of this unusual DC-derived cytokine was concomitant with a peak in numbers of NK cells that produced gamma interferon (IFN-γ) and also enhanced activation of proliferation of IFN-γ+CD4+T cells. Parasite growth was controlled in Lm/CpG-vaccinated animals. This is the first demonstration of the ability of dermal DCs to produce IL-2 and of the activation of NK cells by vaccination in the context of leishmaniasis. Understanding how the Lm/CpG vaccine enhances innate immunity may provide new tools to develop vaccines againstL. major, other chronic infectious diseases, or other conditions, such as cancer.
High Interlaboratory Reproducibility of Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry-Based Species Identification of Nonfermenting Bacteria
Authors: Mellmann A. , Bimet F. , Bizet C. , Borovskaya A. D. , Drake R. R. , Eigner U. , Fahr A. M. , He Y. , Ilina E. N. , Kostrzewa M. , Maier T. , Mancinelli L. , Moussaoui W. , Prévost G. , Putignani L. , Seachord C. L. , Tang Y. W. , Harmsen D.
Published: September 2009

Matrix-assisted laser desorption ionization-time of flight mass spectrometry has emerged as a rapid, cost-effective alternative for bacterial species identification. Identifying 60 blind-coded nonfermenting bacteria samples, this international study (using eight laboratories) achieved 98.75% interlaboratory reproducibility. Only 6 of the 480 samples were misidentified due to interchanges (4 samples) or contamination (1 sample) or not identified because of insufficient signal intensity (1 sample).
Large Dissemination of VIM-2-Metallo-β-Lactamase-Producing
Pseudomonas aeruginosa
Strains Causing Health Care-Associated Community-Onset Infections
Authors: Tsakris Athanassios , Poulou Aggeliki , Kristo Ioulia , Pittaras Theodore , Spanakis Nicholas , Pournaras Spyros , Markou Fani
Published: September 2009

During a 3-year period (May 2005 to April 2008), a series of 45 outpatients presented with community-onset urinary tract infections due to carbapenem-resistant
Pseudomonas aeruginosa
isolates. Forty of them had a history of previous hospitalization or exposure to healthcare facilities, while the remaining five had not been previously admitted to our healthcare facilities or elsewhere within the preceding 12 months. In 18 outpatients, the carbapenem-resistant organisms caused recurrent community-onset urinary tract infections, while in three outpatients the organisms were also implicated in bacteremic episodes. All 45 single-patient
P. aeruginosa
isolates harbored the
bla
VIM-2
metallo-β-lactamase (MBL) gene in a common class 1 integron structure. They belonged to one predominant pulsed-field gel electrophoresis type and three sporadically detected types; two of the sporadic clonal types were identified among outpatients without previous exposure to healthcare facilities, while the predominant clonal type was also identified to cause infections in hospitalized patients. This is the first study documenting that MBL-producing
P. aeruginosa
isolates cause community-onset infections that are related or not with exposure to healthcare facilities. Community-onset infections in our patients most likely resulted from the nosocomial acquisition of MBL producers, followed by a prolonged digestive carriage. The high rate of recurrent infections in the community underlies the difficulty of constraining infections caused by such microorganisms in the extrahospital setting.
Replication Mode and Landscape Topology Differentially Affect RNA Virus Mutational Load and Robustness
Authors: Sardanyés Josep , Solé Ricard V. , Elena Santiago F.
Published: September 2009

Regardless of genome polarity, intermediaries of complementary sense must be synthesized and used as templates for the production of new genomic strands. Depending on whether these new genomic strands become themselves templates for producing extra antigenomic ones, thus giving rise to geometric growth, or only the firstly synthesized antigenomic strands can be used to this end, thus following Luria's stamping machine model, the abundances and distributions of mutant genomes will be different. Here we propose mathematical and bit string models that allow distinguishing between stamping machine and geometric replication. We have observed that, regardless the topology of the fitness landscape, the critical mutation rate at which the master sequence disappears increases as the mechanism of replication switches from purely geometric to stamping machine. We also found that, for a wide range of mutation rates, large-effect mutations do not accumulate regardless the scheme of replication. However, mild mutations accumulate more in the geometric model. Furthermore, at high mutation rates, geometric growth leads to a population collapse for intermediate values of mutational effects at which the stamping machine still produces master genomes. We observed that the critical mutation rate was weakly dependent on the strength of antagonistic epistasis but strongly dependent on synergistic epistasis. In conclusion, we have shown that RNA viruses may increase their robustness against the accumulation of deleterious mutations by replicating as stamping machines and that the magnitude of this benefit depends on the topology of the fitness landscape assumed.
The Myxoma Virus M-T5 Ankyrin Repeat Host Range Protein Is a Novel Adaptor That Coordinately Links the Cellular Signaling Pathways Mediated by Akt and Skp1 in Virus-Infected Cells
Authors: Werden Steven J. , Lanchbury Jerry , Shattuck Donna , Neff Chris , Dufford Max , McFadden Grant
Published: September 2009

Most poxviruses express multiple proteins containing ankyrin (ANK) repeats accounting for a large superfamily of related but unique determinants of poxviral tropism. Recently, select members of this novel family of poxvirus proteins have drawn considerable attention for their potential roles in modulating intracellular signaling networks during viral infection. The rabbit-specific poxvirus, myxoma virus (MYXV), encodes four unique ANK repeat proteins, termed M-T5, M148, M149, and M150, all of which include a carboxy-terminal PRANC domain which closely resembles a cellular protein motif called the F-box domain. Here, we show that each MYXV-encoded ANK repeat protein, including M-T5, interacts directly with the Skp1 component of the host SCF ubiquitin ligase complex, and that the binding of M-T5 to cullin 1 is indirect via binding to Skp1 in the host SCF complex. To understand the significance of these virus-host protein interactions, the various binding domains of M-T5 were mapped. The N-terminal ANK repeats I and II were identified as being important for interaction with Akt, whereas the C-terminal PRANC/F-box-like domain was essential for binding to Skp1. We also report that M-T5 can bind Akt and the host SCF complex (via Skp1) simultaneously in MYXV-infected cells. Finally, we report that M-T5 specifically mediates the relocalization of Akt from the nucleus to the cytoplasm during infection with the wild-type MYXV, but not the M-T5 knockout version of the virus. These results indicate that ANK/PRANC proteins play a critical role in reprogramming disparate cellular signaling cascades to establish a new cellular environment more favorable for virus replication.
Protonation of Individual Histidine Residues Is Not Required for the pH-Dependent Entry of West Nile Virus: Evaluation of the “Histidine Switch” Hypothesis
Authors: Nelson Steevenson , Poddar Subhajit , Lin Tsai-Yu , Pierson Theodore C.
Published: September 2009

Histidine residues have been hypothesized to function as sensors of environmental pH that can trigger the activity of viral fusion proteins. We investigated a requirement for histidine residues in the envelope (E) protein of West Nile virus during pH-dependent entry into cells. Each histidine was individually replaced with a nonionizable amino acid and tested functionally. In each instance, mutants capable of orchestrating pH-dependent infection were identified. These results do not support a requirement for any single histidine as a pH-sensing “switch,” and they suggest that additional features of the E protein are involved in triggering pH-dependent steps in the flavivirus life cycle.
Analysis of Human Immunodeficiency Virus Type 1 Matrix Binding to Membranes and Nucleic Acids
Authors: Alfadhli Ayna , Still Amelia , Barklis Eric
Published: September 2009

The human immunodeficiency virus type 1 (HIV-1) matrix (MA) protein targets HIV-1 precursor Gag (PrGag) proteins to assembly sites at plasma membrane (PM) sites that are enriched in cholesterol and phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P
2
]. MA is myristoylated, which enhances membrane binding, and specifically binds PI(4,5)P
2
through headgroup and 2′ acyl chain contacts. MA also binds nucleic acids, although the significance of this association with regard to the viral life cycle is unclear. We have devised a novel MA binding assay and used it to examine MA interactions with membranes and nucleic acids. Our results indicate that cholesterol increases the selectivity of MA for PI(4,5)P
2
-containing membranes, that PI(4,5)P
2
binding tolerates 2′ acyl chain variation, and that the MA myristate enhances membrane binding efficiency but not selectivity. We also observed that soluble PI(4,5)P
2
analogues do not compete effectively with PI(4,5)P
2
-containing liposomes for MA binding but surprisingly do increase nonspecific binding to liposomes. Finally, we have demonstrated that PI(4,5)P
2
-containing liposomes successfully outcompete nucleic acids for MA binding, whereas other liposomes do not. These results support a model in which RNA binding protects MA from associating with inappropriate cellular membranes prior to PrGag delivery to PM assembly sites.
Herpes Simplex Virus Requires VP11/12 To Induce Phosphorylation of the Activation Loop Tyrosine (Y394) of the Src Family Kinase Lck in T Lymphocytes
Authors: Wagner Melany J. , Smiley James R.
Published: September 2009

Herpes simplex virus (HSV) tegument proteins are released into the cytoplasm during viral entry and hence are among the first viral proteins encountered by an infected cell. Despite the implied importance of these proteins in the evasion of host defenses, the function of some, like virion protein 11/12 (VP11/12), have not been clearly defined. Previously, we reported that VP11/12 is strongly tyrosine phosphorylated during the infection of lymphocytes but not in fibroblasts or an epithelial cell line (G. Zahariadis, M. J. Wagner, R. C. Doepker, J. M. Maciejko, C. M. Crider, K. R. Jerome, and J. R. Smiley, J. Virol.82:6098-6108, 2008). We also showed that tyrosine phosphorylation depends in part on the activity of the lymphocyte-specific Src family kinase (SFK) Lck in Jurkat T cells. These data suggested that VP11/12 is a substrate of Lck and that Lck is activated during HSV infection. Here, we show that HSV infection markedly increases the fraction of Lck phosphorylated on its activation loop tyrosine (Y394), a feature characteristic of activated Lck. A previous report implicated the immediate-early protein ICP0 and the viral serine/threonine kinases US3 and UL13 in the induction of a similar activated phenotype of SFKs other than Lck in fibroblasts and suggested that ICP0 interacts directly with SFKs through their SH3 domain. However, we were unable to detect an interaction between ICP0 and Lck in T lymphocytes, and we show that ICP0, US3, and UL13 are not strictly required for Lck activation. In contrast, VP11/12 interacted with Lck or Lck signaling complexes and was strictly required for Lck activation during HSV infection. Thus, VP11/12 likely modulates host cell signaling pathways for the benefit of the virus.
A Single Point Mutation in Nonstructural Protein NS2 of Bovine Viral Diarrhea Virus Results in Temperature-Sensitive Attenuation of Viral Cytopathogenicity
Authors: Pankraz Alexander , Preis Simone , Thiel Heinz-Jürgen , Gallei Andreas , Becher Paul
Published: September 2009

ForBovine viral diarrhea virus(BVDV), the type species of the genusPestivirusin the familyFlaviviridae, cytopathogenic (cp) and noncytopathogenic (ncp) viruses are distinguished according to their effect on cultured cells. It has been established that cytopathogenicity of BVDV correlates with efficient production of viral nonstructural protein NS3 and with enhanced viral RNA synthesis. Here, we describe generation and characterization of a temperature-sensitive (ts) mutant of cp BVDV strain CP7, termed TS2.7. Infection of bovine cells with TS2.7 and the parent CP7 at 33°C resulted in efficient viral replication and a cytopathic effect. In contrast, the ability of TS2.7 to cause cytopathogenicity at 39.5°C was drastically reduced despite production of high titers of infectious virus. Further experiments, including nucleotide sequencing of the TS2.7 genome and reverse genetics, showed that a Y1338H substitution at residue 193 of NS2 resulted in the temperature-dependent attenuation of cytopathogenicity despite high levels of infectious virus production. Interestingly, TS2.7 and the reconstructed mutant CP7-Y1338H produced NS3 in addition to NS2-3 throughout infection. Compared to the parent CP7, NS2-3 processing was slightly decreased at both temperatures. Quantification of viral RNAs that were accumulated at 10 h postinfection demonstrated that attenuation of the cytopathogenicity of thetsmutants at 39.5°C correlated with reduced amounts of viral RNA, while the efficiency of viral RNA synthesis at 33°C was not affected. Taken together, the results of this study show that a mutation in BVDV NS2 attenuates viral RNA replication and suppresses viral cytopathogenicity at high temperature without altering NS3 expression and infectious virus production in a temperature-dependent manner.
Inhibition of Protein Kinase R Activation and Upregulation of GADD34 Expression Play a Synergistic Role in Facilitating Coronavirus Replication by Maintaining De Novo Protein Synthesis in Virus-Infected Cells
Authors: Wang Xiaoxing , Liao Ying , Yap Pei Ling , Png Kim J. , Tam James P. , Liu Ding Xiang
Published: September 2009

A diversity of strategies is evolved by RNA viruses to manipulate the host translation machinery in order to create an optimal environment for viral replication and progeny production. One of the common viral targets is the α subunit of eukaryotic initiation factor 2 (eIF-2α). In this report, we show that phosphorylation of eIF-2α was severely suppressed in human and animal cells infected with the coronavirus infectious bronchitis virus (IBV). To understand whether this suppression is through inhibition of protein kinase R (PKR), the double-stranded-RNA-dependent kinase that is one of the main kinases responsible for phosphorylation of eIF-2α, cells infected with IBV were analyzed by Western blotting. The results showed that the level of phosphorylated PKR was greatly reduced in IBV-infected cells. Overexpression of IBV structural and nonstructural proteins (nsp) demonstrated that nsp2 is a weak PKR antagonist. Furthermore, GADD34, a component of the protein phosphatase 1 (PP1) complex, which dephosphorylates eIF-2α, was significantly induced in IBV-infected cells. Inhibition of the PP1 activity by okadaic acid and overexpression of GADD34, eIF-2α, and PKR, as well as their mutant constructs in virus-infected cells, showed that these viral regulatory strategies played a synergistic role in facilitating coronavirus replication. Taken together, these results confirm that IBV has developed a combination of two mechanisms, i.e., blocking PKR activation and inducing GADD34 expression, to maintain de novo protein synthesis in IBV-infected cells and, meanwhile, to enhance viral replication.
Quantitative Spectroscopy of the Aurora. III. The Spectrum of Medium Intensity Aurora Between 3100 Å and 4700 Å
Authors: Jones A. Vallance , Gattinger R. L.
Published: September 2009

Averaged spectra of medium intensity (I(4278 Å) ≈ 5 kR) and low intensity aurora (I(4278 Å) ≈ 0.5 kR) in the 3100–4700 Å region at a slit width of 3.5 Å are presented. A detailed composite synthetic spectrum has been prepared for comparison with the observed medium intensity spectrum to determine accurately the relative intensities of the prominent emission features. Included in the synthetic spectrum were the N2 Vegard–Kaplan and second positive systems, the N2+ first negative system, atomic line emissions, and a background continuum. Synthetic comparison spectra of the NO β and O2 Herzberg I systems were also prepared but no significant observed spectral features could be identified as belonging to either of these two systems. Several emissions in the 3300 Å region, each less than 2% of I(4278 Å), remain unidentified.
Level Shifts in Predissociating Systems
Authors: Child M. S.
Published: September 2009

Analytical expressions are derived for the level shifts in systems undergoing type II predissociation. It is shown that the shifts at energies above the curve crossing point may be expected to oscillate in sign, with an amplitude comparable to the line width. At energies below the crossing point the magnitude of the shift is predicted to be much larger than that of the level width, and the formula for the shift reduces to a semiclassical average, over the level in question, of either the perturbation V122(r)/[V1(r) − V2(r)] or the diabatic–adiabatic potential difference [Formula: see text] according to whether it is regarded as a shift from the level supported by the diabatic or the adiabatic potential function.
Absorption Cross Sections of O2(a1Δg) and O2(X3Σg−) in the Region from 1087 to 1700 Å
Authors: Ogawa S. , Ogawa M.
Published: September 2009

An attempt has been made to measure the absorption cross sections of O2 in the metastable state a1Δg from 1087 to 1700 Å. The absorption is measurable (σa ≥ 3 × 10−19 cm2) from around 1500 Å towards shorter wavelengths. Many band structures overlaying various continua have been seen. Absorption cross sections of O2 in the ground state X3Σg− also have been measured in the same wavelength region and our results agree with previously published values within experimental error. The cross sections of O2(a1Δg) are generally larger than those of O2(X3Σg−) below 1290 Å except at the wavelengths of a few strong bands of O2(X3Σg−).
Rotating Clusters in Nuclei
Authors: Pauling Linus , Robinson Arthur B.
Published: September 2009

Values of R, the radius of rotation of the rotating cluster, are calculated from the energy of the lowest 2+ level of even–even nuclei with the assumption that the cluster consists of p2 or n2 respectively, for N or P magic, and of a helion (α) for N or P differing from a magic number by ± 2. The values as a function of A show a zigzag course, which is correlated with the polyspheron structure of the nuclei. If the mantle is not overcrowded the rotating cluster moves within the mantle. When the mantle becomes overcrowded the cluster glides over the surface of the mantle and the value of R increases by one spheron diameter, about 3.2 fm. At certain values of N a change in structure of the nucleus occurs, with increase in radius of the core by half a spheron diameter, permitting the cluster to drop back into the mantle, with decrease in R by half a spheron diameter. In the lanthanon region of permanent prolate deformation the rotating cluster is a polyhelion, containing the number of helions permitted by the difference between Z or N and the nearest magic number, and in the actinon region it contains all the nucleons beyond 208Pb, with maximum p10n16. An explanation is given of the difference between these regions.
Laser Excited Fluorescence Spectra of Gaseous Te2
Authors: Stone T. J. , Barrow R. F.
Published: September 2009

Three lines of the argon ion laser have been used to excite spectra of 128Te2 and 130Te2 which have been photographed with moderate resolution (up to about 300 000). Excitation is critically dependent on the operation of the laser as between multimode or single mode. The development of rotational structure can be varied by control of the pressure of Te2. In addition to the systems A 0u+, B 0u+–X 0g+, well known in the absorption spectrum, four series assigned to B 0u+–X 1g have been analyzed and a new system ascribed to B 1u±–X 1g± has been discovered. Constants (in cm−1) for the ground state of 130Te2 are as follows:[Formula: see text]It is concluded that laser fluorescence spectroscopy, even with fixed frequency lasers, has some advantages over conventional absorption and emission studies.
Structure and Bonding of KrClF: Intermolecular Force Fields in Van Der Waals Molecules
Authors: Novick Stewart E. , Harris Stephen J. , Janda Kenneth C. , Klemperer William
Published: September 2009

The radio frequency and microwave spectrum of KrClF has been measured by molecular beam electric resonance spectroscopy. The molecular constants for the major isotope (84Kr35ClF) are:[Formula: see text]The atomic arrangement is Kr—Cl—F with a linear equilibrium structure and the vibrationally averaged 84Kr—35Cl distance is 3.3884 Å. The molecular structure is very similar to that of ArClF, previously studied in this laboratory. Vibrational frequencies, force constants, estimated well depths, dipole moments, and distances in the two molecules are compared. Molecular constants of the four KrClF isotopes studied are used to derive a vibrational force field for the molecule, including anharmonic and bend–stretch coupling terms. A brief summary of the four linear van der Waals molecules studied spectroscopically in this laboratory is presented, along with a simple and structurally predictive model of the van der Waals bond.
First Observation of the BeAr+ and BeKr+ Molecules: The A2Π–X2Σ+ Band Systems in Emission
Authors: Subbaram K. V. , Coxon J. A. , Jones W. E.
Published: September 2009

Two new emission systems of violet degraded bands near 4000 Å were recorded from microwave discharges through mixtures of beryllium halide vapors with flowing argon and krypton at pressures ~ 200 Torr. The spectra are assigned as the A2Π–X2Σ+ systems of the hitherto unknown BeAr+ and BeKr+ molecules. Molecular constants are reported, and the large binding energies are discussed in terms of a predominant ion-induced dipole interaction.
Studies in Molecular Dynamics by Collision Induced Infrared Absorption in H2–Rare Gas Mixtures. III. H2–He Mixtures at Low Temperatures and Densities
Authors: McKellar A. R. W. , Mactaggart J. W. , Welsh H. L.
Published: September 2009

The collision induced fundamental band of H2 has been studied in H2–He mixtures with absorption paths of 110 and 165 m in a low temperature multiple traversal cell. Spectra were obtained at 18 and 61.5 K with densities in the range of 9 to 60 amagat. Under these conditions the structure of the band is particularly simple and amenable to analysis; the results of a profile analysis of the present spectra are compared with the higher temperature and density results in paper I (Mactaggart and Welsh) of this series. The long observed splitting of the Q branch of the H2 fundamental is manifested here as very sharp dips in the absorption profile at the Q1(0) and Q1(1) molecular frequencies and these provide a striking confirmation of Van Kranendonk's explanation of the 'splitting' as due to an intercollisional interference effect.
Infrared and Raman Spectra of 1,2-Dichloroethane and its Deuterium Compound in the Gaseous, Liquid, and Solid States
Authors: Mizushima S. , Shimanouchi T. , Harada I. , Abe Y. , Takeuchi H.
Published: September 2009

The infrared and Raman spectra of 1,2-dichloroethane and its deuterium compound in the gaseous, liquid, and solid states have been remeasured in the wide range of wavelength by the experimental techniques developed recently. Normal coordinate treatments have been made for crystals as well as for free molecules by use of computer programs made by us, and all the vibrational frequencies observed for free molecules and crystals have been assigned satisfactorily. Our previous conclusions of the existence of the trans and gauche forms have been confirmed spectroscopically and, furthermore, supported theoretically by the quantum mechanical treatment of the internal rotation.
The Absorption Spectrum of the BeH and BeD Molecules in the Vacuum Ultraviolet
Authors: Colin R. , Greef D. De
Published: September 2009

Absorption spectra of the BeH and BeD molecules have been studied in the vacuum ultraviolet using beryllium metal heated in a King furnace filled with 1 atm of hydrogen or deuterium gas. The B2Π–X2Σ+ band system at 1960 Å has been extended and in the region of 1900 to 1700 Å a number of new band systems have been found and analyzed rotationally: B′2Π–X2Σ+, G2Π–X2Σ+, E2Σ+–X2Σ+, and F2Σ+–X2Σ+. A strong band at 1850 Å has been identified as resulting from a transition to a 3d complex (D state) but could not be analyzed. The B, E, F, and D states are Rydberg states yielding an ionization potential of 66 200 ± 500 cm−1 (8.21 ± 0.05 eV). The B state, which has a double minimum potential energy curve, and the G state form a pair of states which result from an avoided crossing. From the analysis of the B′2Π–X2Σ+ system observed in the BeH spectrum a precise value of the ground state dissociation energy is derived: De(X2Σ+) = 17 426 ± 100 cm−1 (2.16 ± 0.01 eV).A weak absorption present at 1980 Å in the BeD spectrum has been tentatively attributed to another 2Σ+–X2Σ+ transition. All the observed excited states exhibit strong perturbations and a C2Σ+ state, probably repulsive, causes strong predissociation. A valueof De(X1Σ+) = 26 328 ± 500 cm−1 (3.26 ± 0.06 eV) is derived for the dissociation energy of the ground state of BeH+.
Spectral Line Identification Studies of Some Stars with Helium Anomalies
Authors: Campbell Bruce , Garrison R. F.
Published: September 2009

Spectral line identification studies have been carried out at 12 Å/mm for four peculiar helium stars in the Orion Belt Region and two standard stars. HD 36 526, HD 37 140, HD 37 321, and HD 37 479 (σ Orionis E) are compared with the sharp lined MK standards, ν Ononis (B3 V) and γ Lyrae (B9 III). The first two program stars have weak helium lines for their colors and also some features similar to those found in the peculiar A stars. This supports the contention that the weak helium line stars are hot analogs of the Ap stars.
Vibrational Spectra of Aminoacetonitrile
Authors: Bak B. , Hansen E. L. , Nicolaisen F. M. , Nielsen O. F.
Published: September 2009

The preparation of pure, stable aminoacetonitrile (1-amino-, 1′-cyanomethane) CH2NH2CN (1) is described. The Raman spectrum, now complete, and a novel infrared spectrum extending over the 50–3600 cm−1 region are reported. A tentative normal vibration analysis is presented and supported by Raman and infrared data from the spectra of CH2NHDCN (2) and CH2ND2CN (3), the interpretation being compatible with Cs symmetry (1 and 3) in accordance with McDonald and Tyler's results from microwave studies of 1, 2, and 3. The predominance of the trans rotamer may be attributed to intramolecular hydrogen bonding but this is too unimportant to influence the vibrational frequencies of gaseous 1, 2, and 3. However, large gas/liquid frequency shifts occur, quite possibly due to intermolecular hydrogen bonding in the liquid phase.
Two New Band Systems in the Near Ultraviolet Spectrum of N2
Authors: Carroll P. K. , Subbaram K. V.
Published: September 2009

Two new weak band systems have been identified under high resolution in the near ultraviolet emission spectrum of molecular nitrogen. They are found to arise from a transition from a hitherto unknown 1Πg state, which it is proposed to call k, to the a′ 1Σu− and w1Δu states. The upper state is interpreted as the 1ΠgRydberg state of configuration … (1πu)4 (3σg) 3dπg. Straightforward treatment of the data by conventional methods gives B0d = 1.906 cm−1, B1d = 1.824 cm−1, T0 = 113 630.87 cm−1, and ΔG1/2 = 2305.92 cm−1. Only the d levels, i.e., the levels corresponding to the 1Πg− component, are observed and the absence of the c levels is attributed to an unusual type of predissociation involving the predicted stable 1Σg+ state which goes to the dissociation limit 2D + 2D (14.522 eV) and the 3Σg− state which arises at the limit 4S + 2P (13.332 eV). A new level at 117 661.11 cm−1 with a Bd value of 1.695 cm−1 is identified as v = 2 of the y1Πg state. A strong homogeneous interaction is found to be occurring between the new k1Πg state and the y1Πg state. A deperturbation calculation is carried out and yields the following deperturbed constants: k1Πg: Be = 1.959 cm−1; αe = 0.031 cm−1; re = 1.109 Å; T0 = 113 723.58 cm−1; ΔG1/2 = 2182.32 cm−1, y1Πg: Be = 1.739 cm−1; αe = 0.017 cm−1; re = 1.177 Å; Te = 114 314.36 cm−1; ωe = 1906.43 cm−1; αexe = 37.51 cm−1.
Molecular Rovibronic Symmetries in Electric and Magnetic Fields
Authors: Watson James K. G.
Published: September 2009

The structures of the symmetry groups for the rovibronic levels of a molecule in a homogeneous electric or magnetic field are derived, and the symmetry classification of the levels in terms of the representations and corepresentations of these groups is discussed. Specific results are given for molecules of the point groups C3, C2v, C3v, D2d, and Td in an electric field. Symmetry in combined electric and magnetic fields and the inclusion of nuclear spins are considered briefly.
Axis Switching in the Transition of HCO: Determination of Molecular Geometry
Authors: Brown J. M. , Ramsay D. A.
Published: September 2009

The [Formula: see text] band systems of HCO and DCO have been reinvestigated with higher resolving power than in earlier work. Some weak lines have been assigned to K′ = 0 – K″ = 0 and K′ = 0 – K″ = 2 subbands; these lines derive their intensity from axis switching. The new data give values for the A rotational constants of HCO and DCO and permit a more reliable determination of the ground state geometry, viz, r0(CH) = 1.125(5) Å, r0(CO) = 1.175(1) Å, [Formula: see text]. The sign of the spin–rotation constant εaa has been shown to be positive.
On the Problem of Parity Violation in Atoms
Authors: Alekseev V. , Sobel'man I. , Zel'dovich B.
Published: September 2009

Possibilities of observation of the electron–nucleus weak interaction in atoms are discussed. Parity violating effects, e.g., circular dichroism, rotation of polarization planes, and splitting of frequencies of the circularly polarized modes of an interferometer are calculated for a number of atomic transitions.
COUPLING EFFICIENCY OF METAMATERIAL MAGNETOOPTICAL INTEGRATED ISOLATOR
Authors: EL-KHOZONDAR HALA J. , EL-KHOZONDAR RIFA J. , SHABAT MOHAMMED M.
Published: September 2009

Nonreciprocal devices such as isolators are well-known in light wave communication systems. The integrated optical isolator is presented where the magnetic field modes propagate perpendicular to the in-plane magnetization of a planar magnetooptical waveguide. The cladding and film of optical isolator are made of magnetic materials with magnetization adjusted to be parallel to their plan. The substrate is filled with new artificial metamaterials (MTMs). The dispersion equation of the transverse magnetic (TM) fields is derived. The difference Δβ between the phase constant for forward and backward propagation is calculated numerically for different values of MTMs permittivity (εs) and permeability (μs). Results show that the cutoff thickness is different for forward and backward propagation and varies with the MTMs parameters. The cutoff thickness of the isolator is selected such that the coupling coefficients of the isolator with optical fiber are obviously different for forward and backward propagation.
UNCONVENTIONAL LOW-ENERGY EXCITATIONS OF CUPRATE SUPERCONDUCTORS
Authors: YEH N.-C. , BEYER A. D.
Published: September 2009

Recent development in the physics of high-temperature cuprate superconductivity is reviewed, with special emphasis on the phenomena of unconventional and non-universal low-energy excitations of hole- and electron-type cuprate superconductors and the possible physical origin. A phenomenology based on coexisting competing orders with cuprate superconductivity in the ground state appears to provide a consistent account for a wide range of experimental findings, including the presence (absence) of pseudogaps and Fermi arcs above the superconducting transition Tc in hole-type (electron-type) cuprate superconductors and the novel conductance modulations below Tc, particularly in the vortex state. Moreover, the competing order scenario is compatible with the possibility of pre-formed Cooper pairs and significant phase fluctuations in cuprate superconductors. The physical implications of the unified phenomenology and remaining open issues for the microscopic mechanism of cuprate superconductivity are discussed.
GEOMETRIC PHASE IN A GENERALIZED TIME-DEPENDENT GIANT SPIN MODEL
Authors: WANG AN-LING , LIU FU-PING , YU ZHAO-XIAN , JIAO ZHI-YONG
Published: September 2009

By using of the invariant theory, we have studied the generalized time-dependent giant spin model. The dynamical and geometric phases are given, respectively. The Aharonov–Anandan phase is also obtained under the cyclical evolution.
METAL-INSULATOR TRANSITION OF NaxWO3 STUDIED BY ANGLE-RESOLVED PHOTOEMISSION SPECTROSCOPY
Authors: RAJ SATYABRATA , SATO TAKAFUMI , SOUMA SEIGO , TAKAHASHI TAKASHI , SARMA D. D. , MAHADEVAN PRIYA
Published: September 2009

The electronic structure of sodium tungsten bronzes Na x WO 3 is investigated by high-resolution angle-resolved photoemission spectroscopy (ARPES). The ARPES spectra measured in both insulating and metallic phases of Na x WO 3 reveals the origin of metal-insulator transition (MIT) in sodium tungsten bronze system. It is found that in insulating Na x WO 3 the states near the Fermi level (EF) are localized due to the strong disorder caused by the random distribution of Na + ions in WO 3 lattice. Due to the presence of disorder and long-range Coulomb interaction of conduction electrons, a soft Coulomb gap arises, where the density of states vanishes exactly at EF. In the metallic regime the states near EF are populated and the Fermi level shifts upward rigidly with increasing electron doping (x). Volume of electron-like Fermi surface (FS) at the Γ(X) point of the Brillouin zone gradually increases with increasing Na concentration due to W 5d t2g band filling. A rigid shift of the Fermi energy is found to give a qualitatively good description of the Fermi surface evolution. As we move from bulk-sensitive to more surface sensitive photon energy, we found the emergence of Fermi surfaces at X(M) and M(R) points similar to the one at the Γ(X) point in the metallic regime, suggesting that the reconstruction of surface was due to rotation/deformation of WO 6 octahedra.
A large-conductance (BK) potassium channel subtype affects both growth and mineralization of human osteoblasts
Authors: Henney Neil C. , Li Bo , Elford Carole , Reviriego Pablo , Campbell Anthony K. , Wann Kenneth T. , Evans Bronwen A. J.
Published: September 2009

The pharmacology of the large-conductance K+ (BK) channel in human osteoblasts is not well defined, and its role in bone is speculative. Here we assess BK channel properties in MG63 cells and primary human osteoblasts and determine whether pharmacological modulation affects cell function. We used RT-PCR and patch-clamp methods to determine the expression of BK channel subunits and cell number assays in the absence and presence of BK channel modulators. RT-PCR showed the presence of KCNMA1, KCNMB1, KCNMB2, KCNMB3, and KCNMB4 subunits. The BK channel was voltage dependent, with a mean unitary conductance of 228.8 pS ( n = 10) in cell-attached patches (140 mM K+/140 mM K+) and a conductance of 142.5 pS ( n = 16) in excised outside-out and 155 pS ( n = 6) in inside-out patches in 3 mM K+/140 mM K+. The selectivity ratio (ratio of K+ to Na+ permeability) was 15:1. The channel was blocked by tetraethylammonium (TEA, 0.3 mM), iberiotoxin (5–60 nM), tetrandrine (5–30 μM), and paxilline (10 μM) and activated by isopimaric acid (20 μM). BK channel modulators affected MG63 cell numbers: TEA and tetrandrine significantly increased cell numbers at low concentrations (3 mM and 3 μM, respectively) and reduced cell numbers at higher concentrations (>10 mM and >10 μM, respectively). Neither iberiotoxin (20–300 nM) nor slotoxin (300 nM) affected cell numbers. The increase in cell numbers by TEA was blocked by isopimaric acid. TEA (0.1–3.0 mM) significantly increased mineralization in primary osteoblasts. In conclusion, the BK channel has a distinctive pharmacology and is thus a target for therapeutic strategies aimed at modulating osteoblast proliferation and function.
Filamin A is required for vimentin-mediated cell adhesion and spreading
Authors: Kim Hugh , Nakamura Fumihiko , Lee Wilson , Shifrin Yulia , Arora Pamela , McCulloch Christopher A.
Published: September 2009

Cell adhesion and spreading are regulated by complex interactions involving the cytoskeleton and extracellular matrix proteins. We examined the interaction of the intermediate filament protein vimentin with the actin cross-linking protein filamin A in regulation of spreading in HEK-293 and 3T3 cells. Filamin A and vimentin-expressing cells were well spread on collagen and exhibited numerous cell extensions enriched with filamin A and vimentin. By contrast, cells treated with small interfering RNA (siRNA) to knock down filamin A or vimentin were poorly spread; both of these cell populations exhibited >50% reductions of cell adhesion, cell surface β1 integrin expression, and β1 integrin activation. Knockdown of filamin A reduced vimentin phosphorylation and blocked recruitment of vimentin to cell extensions, whereas knockdown of filamin and/or vimentin inhibited the formation of cell extensions. Reduced vimentin phosphorylation, cell spreading, and β1 integrin surface expression, and activation were phenocopied in cells treated with the protein kinase C inhibitor bisindolylmaleimide; cell spreading was also reduced by siRNA knockdown of protein kinase C-ε. By immunoprecipitation of cell lysates and by pull-down assays using purified proteins, we found an association between filamin A and vimentin. Filamin A also associated with protein kinase C-ε, which was enriched in cell extensions. These data indicate that filamin A associates with vimentin and to protein kinase C-ε, thereby enabling vimentin phosphorylation, which is important for β1 integrin activation and cell spreading on collagen.
Conditional knockout of Mn-SOD targeted to type IIB skeletal muscle fibers increases oxidative stress and is sufficient to alter aerobic exercise capacity
Authors: Lustgarten Michael S. , Jang Youngmok C. , Liu Yuhong , Muller Florian L. , Qi Wenbo , Steinhelper Mark , Brooks Susan V. , Larkin Lisa , Shimizu Takahiko , Shirasawa Takuji , McManus Linda M. , Bhattacharya Arunabh , Richardson Arlan , Van Remmen Holly
Published: September 2009

In vitro studies of isolated skeletal muscle have shown that oxidative stress is limiting with respect to contractile function. Mitochondria are a potential source of muscle function-limiting oxidants. To test the hypothesis that skeletal muscle-specific mitochondrial oxidative stress is sufficient to limit muscle function, we bred mice expressing Cre recombinase driven by the promoter for the inhibitory subunit of troponin ( TnIFast-iCre) with mice containing a floxed Sod2 ( Sod2 fl/fl) allele. Mn-SOD activity was reduced by 82% in glycolytic (mainly type II) muscle fiber homogenates from young TnIFastCreSod2 fl/fl mice . Furthermore, Mn-SOD content was reduced by 70% only in type IIB muscle fibers. Aconitase activity was decreased by 56%, which suggests an increase in mitochondrial matrix superoxide. Mitochondrial superoxide release was elevated more than twofold by mitochondria isolated from glycolytic skeletal muscle in TnIFastCreSod2 fl/fl mice. In contrast, the rate of mitochondrial H2O2 production was reduced by 33%, and only during respiration with complex II substrate. F2-isoprostanes were increased by 36% in tibialis anterior muscles isolated from TnIFastCreSod2 fl/fl mice. Elevated glycolytic muscle-specific mitochondrial oxidative stress and damage in TnIFastCreSod2 fl/fl mice were associated with a decreased ability of the extensor digitorum longus and gastrocnemius muscles to produce contractile force as a function of time, whereas force production by the soleus muscle was unaffected. TnIFastCreSod2 fl/fl mice ran 55% less distance on a treadmill than wild-type mice. Collectively, these data suggest that elevated mitochondrial oxidative stress and damage in glycolytic muscle fibers are sufficient to reduce contractile muscle function and aerobic exercise capacity.
Glucocorticoid reamplification within cells intensifies NF-κB and MAPK signaling and reinforces inflammation in activated preadipocytes
Authors: Ishii-Yonemoto Takako , Masuzaki Hiroaki , Yasue Shintaro , Okada Sadanori , Kozuka Chisayo , Tanaka Tomohiro , Noguchi Michio , Tomita Tsutomu , Fujikura Junji , Yamamoto Yuji , Ebihara Ken , Hosoda Kiminori , Nakao Kazuwa
Published: September 2009

Increased expression and activity of the intracellular glucocorticoid-reactivating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) contribute to dysfunction of adipose tissue. Although the pathophysiological role of 11β-HSD1 in mature adipocytes has long been investigated, its potential role in preadipocytes still remains obscure. The present study demonstrates that the expression of 11β-HSD1 in preadipocyte-rich stromal vascular fraction (SVF) cells in fat depots from ob/ob and diet-induced obese mice was markedly elevated compared with lean control. In 3T3-L1 preadipocytes, the level of mRNA and reductase activity of 11β-HSD1 was augmented by TNF-α, IL-1β, and LPS, with a concomitant increase in inducible nitric oxide synthase (iNOS), monocyte chemoattractant protein-1 (MCP-1), or IL-6 secretion. Pharmacological inhibition of 11β-HSD1 and RNA interference against 11β-HSD1 reduced the mRNA and protein levels of iNOS, MCP-1, and IL-6. In contrast, overexpression of 11β-HSD1 further augmented TNF-α-induced iNOS, IL-6, and MCP-1 expression. Moreover, 11β-HSD1 inhibitors attenuated TNF-α-induced phosphorylation of NF-κB p65 and p38-, JNK-, and ERK1/2-MAPK. Collectively, the present study provides novel evidence that inflammatory stimuli-induced 11β-HSD1 in activated preadipocytes intensifies NF-κB and MAPK signaling pathways and results in further induction of proinflammatory molecules. Not limited to 3T3-L1 preadipocytes, we also demonstrated that the notion was reproducible in the primary SVF cells from obese mice. These findings highlight an unexpected, proinflammatory role of reamplified glucocorticoids within preadipocytes in obese adipose tissue.
Natural antibodies and complement modulate intimal thickening after arterial injury
Authors: Dimayuga Paul C. , Cesena Fernando H. Y. , Chyu Kuang-Yuh , Yano Juliana , Amorn Allen , Fishbein Michael C. , Shah Prediman K. , Cercek Bojan
Published: September 2009

Immune factors are involved in modulating neointimal response to arterial wall injury, but the role of individual immune effectors in this response remains unclear. Using a carotid cuff injury model in mice, we tested the role of immunoglobulin isotypes in modulating intimal thickening by using adoptive transfer of splenocytes from WT mice, or the direct administration of IgG or IgM into immune-deficient Rag-1−/− [Rag-1 knockout (Rag-1KO)] mice. The direct role of complement was also tested by depletion of complement. Splenocytes from WT mice were isolated and adoptively transferred to Rag-1KO mice subjected to carotid cuff arterial injury. Transfer of splenocytes to Rag-1KO mice resulted in increased serum IgM and IgG within 48 h and were comparable to WT levels by 21 days after injury. Splenocyte transfer in Rag-1KO decreased intimal area by 40% compared with Rag-1KO mice without cell transfer. To further differentiate the relative contribution of IgM or IgG in reducing intimal thickening, additional groups of Rag-1KO mice were subjected to injury and given intravenous injections of pooled mouse IgG or IgM. Both IgG and IgM treatment significantly reduced intimal thickening compared with untreated Rag-1KO mice. Immunoglobulin treatments modified serum complement C3 profile and decreased C3 presence in injured arteries. Depletion of C3 using cobra venom factor in Rag-1KO mice significantly decreased intimal thickening. Our results identify the direct role of natural IgG and IgM, and complement in the modulation of neointimal response to arterial injury.