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Sample records for akademie vd cesk

  1. VD--Epidemic Among Teenagers. Public Affairs Pamphlet No. 517.

    ERIC Educational Resources Information Center

    Saltman, Jules

    This booklet discusses the venereal disease (VD) epidemic among teenagers. After presenting some basic facts about VD, the effect, treatment, and prevention of both gonorrhea and syphilis is discussed. The booklet then examines statistics concerning gonorrhea and syphilis. It also looks at why the VD epidemic exists and includes discussions on (1)…

  2. Hyphopodium-Specific VdNoxB/VdPls1-Dependent ROS-Ca2+ Signaling Is Required for Plant Infection by Verticillium dahliae

    PubMed Central

    Zhao, Yun-Long; Zhou, Ting-Ting; Guo, Hui-Shan

    2016-01-01

    Verticillium dahliae is a phytopathogenic fungus obligate in root infection. A few hyphopodia differentiate from large numbers of hyphae after conidia germination on the root surface for further infection. However, the molecular features and role of hyphopodia in the pathogenicity of V. dahliae remain elusive. In this study, we found that the VdPls1, a tetraspanin, and the VdNoxB, a catalytic subunit of membrane-bound NADPH oxidases for reactive oxygen species (ROS) production, were specifically expressed in hyphopodia. VdPls1 and VdNoxB highly co-localize with the plasma membrane at the base of hyphopodia, where ROS and penetration pegs are generated. Mutant strains, VdΔnoxb and VdΔpls1, in which VdPls1 and VdNoxB were deleted, respectively, developed defective hyphpodia incapable of producing ROS and penetration pegs. Defective plasma membrane localization of VdNoxB in VdΔpls1 demonstrates that VdPls1 functions as an adaptor protein for the recruitment and activation of the VdNoxB. Furthermore, in VdΔnoxb and VdΔpls1, tip-high Ca2+ accumulation was impaired in hyphopodia, but not in vegetative hyphal tips. Moreover, nuclear targeting of VdCrz1 and activation of calcineurin-Crz1 signaling upon hyphopodium induction in wild-type V. dahliae was impaired in both knockout mutants, indicating that VdPls1/VdNoxB-dependent ROS was specifically required for tip-high Ca2+ elevation in hyphopodia to activate the transcription factor VdCrz1 in the regulation of penetration peg formation. Together with the loss of virulence of VdΔnoxb and VdΔpls1, which are unable to initiate colonization in cotton plants, our data demonstrate that VdNoxB/VdPls1-mediated ROS production activates VdCrz1 signaling through Ca2+ elevation in hyphopodia, infectious structures of V. dahliae, to regulate penetration peg formation during the initial colonization of cotton roots. PMID:27463643

  3. Identification and characterization of a pathogenicity-related gene VdCYP1 from Verticillium dahliae

    PubMed Central

    Zhang, Dan-Dan; Wang, Xin-Yan; Chen, Jie-Yin; Kong, Zhi-Qiang; Gui, Yue-Jing; Li, Nan-Yang; Bao, Yu-Ming; Dai, Xiao-Feng

    2016-01-01

    Verticillium dahliae is a phytopathogenic fungus that causes vascular wilt disease in a wide variety of crop plants, thereby causing extensive economic loss. In present study, one V. dahliae T-DNA mutant M01C06 showed the pathogenicity loss on cotton, and the expression of a flanking gene encoding cytochrome P450 monooxygenase (P450, VdCYP1) was strongly repressed. P450s of fungi could affect the fungal pathogenicity by involving in the synthesis of secondary metabolites. However, there was no report about the pathogenic function of P450s in V. dahliae. VdCYP1 gene deletion and complementation experiments confirmed that VdCYP1 was the pathogenicity-related gene in V. dahliae. A comparison of culture supernatants of the VdCYP1 deletion mutants and wild-type strains indicates that at least 14 kinds of secondary metabolites syntheses were affected due to VdCYP1 gene deletion. One of these compounds, sulfacetamide, had the ability to induce the necrosis and wilting symptoms in cotton. Above results indicate that VdCYP1 could participate in pathogenesis by involving the secondary metabolism in V. dahliae, such as the compound sulfacetamide. In conclusion, VdCYP1 acts as an important pathogenicity-related factor to involve in secondary metabolism that likely contributes to the pathogenic process in V. dahliae. PMID:27329129

  4. Isolation and functional analysis of the pathogenicity-related gene VdPR3 from Verticillium dahliae on cotton.

    PubMed

    Zhang, Ya-Lin; Li, Zhi-Fang; Feng, Zi-Li; Feng, Hong-Jie; Zhao, Li-Hong; Shi, Yong-Qiang; Hu, Xiao-Ping; Zhu, He-Qin

    2015-11-01

    The fungal plant pathogen Verticillium dahliae is the causal agent of vascular wilt, a disease that can seriously diminish cotton fiber yield. The pathogenicity mechanism and the identity of the genes that interact with cotton during the infection process still remain unclear. In this study, we investigated the low-pathogenic, non-microsclerotium-producing mutant vdpr3 obtained in a previous study from the screening of a T-DNA insertional library of the highly virulent isolate Vd080; the pathogenicity-related gene (VdPR3) in wild-type strain Vd080 was cloned. Knockout mutants (ΔVdPR3) showed lower mycelium growth and obvious reduction in sporulation ability without microsclerotium formation. An evaluation of carbon utilization in mutants and wild-type isolate Vd080 demonstrated that mutants-lacking VdPR3 exhibited decreased cellulase and amylase activities, which was restored in the complementary mutants (ΔVdPR3-C) to levels similar to those of Vd080. ΔVdPR3 postponed infectious events in cotton and showed a significant reduction in pathogenicity. Reintroduction of a functional VdPR3 copy into ΔVdPR3-C restored the ability to infect cotton plants. These results suggest that VdPR3 is a multifunctional gene involved in growth development, extracellular enzyme activity, and virulence of V. dahliae on cotton.

  5. 14. Cortlandt V.D. Hubbard, Photographer November 1967 DETAIL: ORCHESTRA SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. Cortlandt V.D. Hubbard, Photographer November 1967 DETAIL: ORCHESTRA SECTION AND TIERS SHOWING DECORATED COLUMNS, BRACKETS, MOLDINGS - American Academy of Music, 232-246 South Broad Street, Philadelphia, Philadelphia County, PA

  6. VdMsb regulates virulence and microsclerotia production in the fungal plant pathogen Verticillium dahliae.

    PubMed

    Tian, Liangliang; Xu, Jun; Zhou, Lei; Guo, Wangzhen

    2014-10-25

    The vascular wilt fungus Verticillium dahliae infects the roots of cotton plants and can seriously diminish the yield and quality of this and other dicotyledons. However, the key genes involved in V. dahliae infection and pathogenesis in cotton remain unclear. Msb encodes a transmembrane mucin that is highly conserved in the MAPK signal pathway. Msb has been implicated previously in pathogenicity in various aerial plant fungi. In this study, V. dahliae Msb (VdMsb) was found to be required for fungal virulence and microsclerotia production. Strains lacking VdMsb exhibited reduced conidiation and microsclerotia formation. Compared with wild-type and gene-complemented strains, the invasive growth and adhesive capacity of VdMsb deletion mutants were significantly decreased. These results suggest that VdMsb plays a role in development and virulence in V. dahliae.

  7. Gravity affects the responsiveness of Runx2 to 1, 25-dihydroxyvitamin D3 (VD3)

    NASA Astrophysics Data System (ADS)

    Guo, Feima; Dai, Zhongquan; Wu, Feng; Liu, Zhaoxia; Tan, Yingjun; Wan, Yumin; Shang, Peng; Li, Yinghui

    2013-03-01

    Bone loss resulting from spaceflight is mainly caused by decreased bone formation, and decreased osteoblast proliferation and differentiation. Transcription factor Runx2 plays an important role in osteoblast differentiation and function by responding to microenvironment changes including cytokine and mechanical factors. The effects of 1, 25-dihydroxyvitamin D3 (VD3) on Runx2 in terms of mechanical competence is far less clear. This study describes how gravity affects the response of Runx2 to VD3. A MC3T3-6OSE2-Luc osteoblast model was constructed in which the activity of Runx2 was reflected by reporter luciferase activity identifed by bone-related cytokines. The results showed that luciferase activity in MC3T3-6OSE2-Luc cells transfected with Runx2 was twice that of the vacant vector. Alkaline phosphatase (ALP) activity was increased in MC3T3-6OSE2-Luc cells by different concentrations of IGF-I and BMP2. MC3T3-6OSE2-Luc cells were cultured under simulated microgravity or centrifuge with or without VD3. In simulated microgravity, luciferase activity was decreased after 48 h of clinorotation culture, but increased in the centrifuge culture. Luciferase activity was increased after VD3 treatment in normal conditions and simulated microgravity, the increase in luciferase activity in simulated microgravity was lower than that in the 1 g condition when simultaneously treated with VD3 and higher than that in the centrifuge condition. Co-immunoprecipitation showed that the interaction between the VD3 receptor (VDR) and Runx2 was decreased by simulated microgravity, but increased by centrifugation. From these results, we conclude that gravity affects the response of Runx2 to VD3 which results from an alteration in the interaction between VDR and Runx2 under different gravity conditions.

  8. Exact kinetic energy enables accurate evaluation of weak interactions by the FDE-vdW method

    SciTech Connect

    Sinha, Debalina; Pavanello, Michele

    2015-08-28

    The correlation energy of interaction is an elusive and sought-after interaction between molecular systems. By partitioning the response function of the system into subsystem contributions, the Frozen Density Embedding (FDE)-vdW method provides a computationally amenable nonlocal correlation functional based on the adiabatic connection fluctuation dissipation theorem applied to subsystem density functional theory. In reproducing potential energy surfaces of weakly interacting dimers, we show that FDE-vdW, either employing semilocal or exact nonadditive kinetic energy functionals, is in quantitative agreement with high-accuracy coupled cluster calculations (overall mean unsigned error of 0.5 kcal/mol). When employing the exact kinetic energy (which we term the Kohn-Sham (KS)-vdW method), the binding energies are generally closer to the benchmark, and the energy surfaces are also smoother.

  9. Exact kinetic energy enables accurate evaluation of weak interactions by the FDE-vdW method.

    PubMed

    Sinha, Debalina; Pavanello, Michele

    2015-08-28

    The correlation energy of interaction is an elusive and sought-after interaction between molecular systems. By partitioning the response function of the system into subsystem contributions, the Frozen Density Embedding (FDE)-vdW method provides a computationally amenable nonlocal correlation functional based on the adiabatic connection fluctuation dissipation theorem applied to subsystem density functional theory. In reproducing potential energy surfaces of weakly interacting dimers, we show that FDE-vdW, either employing semilocal or exact nonadditive kinetic energy functionals, is in quantitative agreement with high-accuracy coupled cluster calculations (overall mean unsigned error of 0.5 kcal/mol). When employing the exact kinetic energy (which we term the Kohn-Sham (KS)-vdW method), the binding energies are generally closer to the benchmark, and the energy surfaces are also smoother.

  10. mBEEF-vdW: Robust fitting of error estimation density functionals

    NASA Astrophysics Data System (ADS)

    Lundgaard, Keld T.; Wellendorff, Jess; Voss, Johannes; Jacobsen, Karsten W.; Bligaard, Thomas

    2016-06-01

    We propose a general-purpose semilocal/nonlocal exchange-correlation functional approximation, named mBEEF-vdW. The exchange is a meta generalized gradient approximation, and the correlation is a semilocal and nonlocal mixture, with the Rutgers-Chalmers approximation for van der Waals (vdW) forces. The functional is fitted within the Bayesian error estimation functional (BEEF) framework [J. Wellendorff et al., Phys. Rev. B 85, 235149 (2012), 10.1103/PhysRevB.85.235149; J. Wellendorff et al., J. Chem. Phys. 140, 144107 (2014), 10.1063/1.4870397]. We improve the previously used fitting procedures by introducing a robust MM-estimator based loss function, reducing the sensitivity to outliers in the datasets. To more reliably determine the optimal model complexity, we furthermore introduce a generalization of the bootstrap 0.632 estimator with hierarchical bootstrap sampling and geometric mean estimator over the training datasets. Using this estimator, we show that the robust loss function leads to a 10 % improvement in the estimated prediction error over the previously used least-squares loss function. The mBEEF-vdW functional is benchmarked against popular density functional approximations over a wide range of datasets relevant for heterogeneous catalysis, including datasets that were not used for its training. Overall, we find that mBEEF-vdW has a higher general accuracy than competing popular functionals, and it is one of the best performing functionals on chemisorption systems, surface energies, lattice constants, and dispersion. We also show the potential-energy curve of graphene on the nickel(111) surface, where mBEEF-vdW matches the experimental binding length. mBEEF-vdW is currently available in gpaw and other density functional theory codes through Libxc, version 3.0.0.

  11. VD: is society willing to meet the price of realistic legislation?

    PubMed

    Rozovsky, L E

    1972-12-23

    A significant question at this time is whether there is any rationale for venereal disease (VD) legislation and legislation for all communicable diseases. VD legislation, to be effective, needs to reflect the causes of the spread of the disease. The causes would appear to rest on an increase in sexual activity and indiscriminate sexual activity among vast numbers of people throughout the world rather than an increase in the activity of the disease itself. Causes include increased population mobility and migration, urbanization, higher birthrates increasing the youthful and most sexually active part of the population, the discarding of traditional values, the removal of the fear of pregnancy by modern contraceptives, and a lack of knowledge concerning the nature of VD. Early legislation tried to control at least 1 cause of the spread of VD, i.e., prostitution. Legislation was also directed against homosexuality. 1 method of attacking indiscriminate sexual activity was to legislate against advertisements for curing VD. Legislation has also attempted to control individuals infected by making it an offense to communicate VD. The Criminal Code of Canada and VD regulations throughout the world are illustrative of such efforts. There has been no success in gaining convictions. Clearly, private activities cannot be controlled by law, but a legislative requirement for a premarital examination for VD is realistic since marriage is a public act. To combat the majority of cases, most jurisdictions have chosen compulsory reporting, tracing of contact, and control--all by force of law. Legislation varies from country to country as to what information is reported, to whom and under what conditions, but the basic system in those countries which employ a compulsory contract tracing system is the same in that to a large degree it depends for its success on the private physician. Legislation fails because it has tried to force the private physician to be a public officer. Unrealistic

  12. VdCrz1 is involved in microsclerotia formation and required for full virulence in Verticillium dahliae.

    PubMed

    Xiong, Dianguang; Wang, Yonglin; Tang, Chen; Fang, Yulin; Zou, Jingyi; Tian, Chengming

    2015-09-01

    Calcium signaling plays crucial roles in ion stress tolerance, sporulation and pathogenicity in fungi. Although the signaling pathway mediated by calcineurin and the calcineurin-responsive zinc finger transcription factor Crz1 is well characterized in other fungi, this pathway is not well characterized in the phytopathogenic fungus, Verticillium dahliae. To better understand the role of this calcineurin-dependent transcription factor in V. dahliae, an ortholog of CRZ1, VdCrz1, was identified and characterized functionally. Transcriptional analysis of VdCrz1 and GFP expression driven by the VdCrz1 promoter indicated that VdCrz1 was involved in microsclerotia development. After targeted deletion of VdCrz1, microsclerotia formation and melanin accumulation were impaired. Furthermore, the ΔVdCrz1 mutants were hypersensitive to high concentrations of Ca(2+) and cell wall-perturbing agents, such as sodium dodecyl sulfate. The addition of Mg(2+) to the medium restores the microsclerotia formation in ΔVdCrz1 mutants. The ΔVdCrz1 mutants exhibited delayed Verticillium wilt symptoms on smoke tree. These results suggest that VdCrz1 plays important roles in Ca(2+) signaling, cell wall integrity, microsclerotia development and full virulence in V. dahliae.

  13. VD 16 and the Control of German Imprints: A Review Article.

    ERIC Educational Resources Information Center

    Hackenberg, Michael

    1984-01-01

    Reviews the first volume of Germany's national bibliography of sixteenth-century editions--"Verzeichnis der im deutschen Sprachbereich erschienenen Drucke des XVI. Jahrhunderts" (VD16)--and describes the project which is currently cataloging and recarding all known editions printed between 1501 and 1600 in German-speaking regions of that…

  14. Functional Analysis of the Pathogenicity-Related Gene VdPR1 in the Vascular Wilt Fungus Verticillium dahliae

    PubMed Central

    Zhang, Ya-Lin; Li, Zhi-Fang; Feng, Zi-Li; Feng, Hong-Jie; Shi, Yong-Qiang; Zhao, Li-Hong; Zhang, Xi-Ling; Zhu, He-Qin

    2016-01-01

    Verticillium dahliae Kleb., the causal agent of vascular wilt, can seriously diminish the yield and quality of many crops, including cotton. The pathogenic mechanism to cotton is complicated and unclear now. To screen pathogencity related genes and identify their function is the reliable way to explain the mechanism. In this study, we obtained a low-pathogenicity mutant vdpr1 from a T-DNA insertional library of the highly virulent isolate of V. dahliae Vd080, isolated from cotton. The tagged gene was named pathogenicity-related gene (VdPR1). The deletion mutant ΔVdPR1 did not form microsclerotia and showed a drastic reduction in spore yield and mycelial growth, compared to wild type. Also, ΔVdPR1 showed significantly lower protease and cellulase activities than those of wild type. Complementation of the mutant strain with VdPR1 (strain ΔVdPR1-C) almost completely rescued the attributes described above to wild-type levels. The knockout mutant ΔVdPR1 showed delayed infection, caused mild disease symptoms, formed a smaller biomass in roots of the host, and showed compromised systemic invasive growth in the xylem. These results suggest that VdPR1 is a multifaceted gene involved in regulating the growth development, early infection and pathogenicity of V. dahliae. PMID:27846253

  15. VdNUC-2, the Key Regulator of Phosphate Responsive Signaling Pathway, Is Required for Verticillium dahliae Infection

    PubMed Central

    Deng, Sheng; Wang, Cai-yue; Zhang, Xin; Wang, Qing; Lin, Ling

    2015-01-01

    In fungal cells, a phosphate (Pi) responsive signaling and metabolism (PHO) pathway regulates Pi-homeostasis. NUC-2/PHO81 and its homologs are one of the most important components in the regulation pathway. In soil-borne phytopathogenic fungus Verticillium dahliae, we identified a Neurospora crassa nuc-2 homolog gene VdNUC-2. VdNUC-2 is composed of 1,018 amino acids, and is highly conserved in tested filamentous fungi. Under conditions of Pi-starvation, compared with the wild-type strain and ectopic complementation strains, the VdNUC-2 knocked out mutants exhibited reduced radial growth, decreased production of conidia and microsclerotia, and were more sensitive to hydrogen peroxide stress. The virulence of VdNUC-2 defective mutants was significantly compromised, and that was unable to be restored by exogenous application of extra Pi. Additionally, the deletion mutants of VdNUC-1, a key transcription factor gene positively controlled by VdNUC-2 in the PHO pathway, showed the similar cultural phenotypes as VdNUC-2 mutants when both of them grew in Pi-limited conditions. However, the virulence of VdNUC-1 mutants was comparable to the wild-type strain. These evidences indicated that the virulence reduction in VdNUC-2 mutants is not due to the interruptions in the PHO pathway or the disturbance of Pi-homeostasis in V. dahliae cytoplasm. VdNUC-2 is not only a crucial gene in the PHO pathway in V. dahliae, but also is required for the full virulence during host-infection. PMID:26670613

  16. The Mitogen-Activated Protein Kinase Kinase VdPbs2 of Verticillium dahliae Regulates Microsclerotia Formation, Stress Response, and Plant Infection

    PubMed Central

    Tian, Longyan; Wang, Yonglin; Yu, Jun; Xiong, Dianguang; Zhao, Hengjun; Tian, Chengming

    2016-01-01

    Verticillium dahliae, a ubiquitous phytopathogenic fungus, forms resting structures, known as microsclerotia that play crucial roles in Verticillium wilt diseases. VdHog1, a mitogen-activated protein kinase (MAPK), controls microsclerotia formation, virulence, and stress response in V. dahliae. In this study, we present detailed evidence that the conserved upstream component of VdHog1, VdPbs2, is a key regulator of microsclerotia formation, oxidative stress and fungicide response and plant virulence in V. dahliae. We identified VdPbs2, homologous to the yeast MAPK kinase Pbs2. Similar to the VdHog1 deletion mutant, VdPbs2 deletion strains exhibited delayed melanin synthesis and reduced formation of microsclerotia. When exposed to stresses, VdPbs2 mutants were more sensitive than the wild type to osmotic agents and peroxide, but more resistant to inhibitors of cell wall synthesis and some fungicides. Finally, VdPbs2 deletion mutants exhibited reduced virulence on smoke tree and tobacco seedlings. When taken together, we implicate that VdPbs2 and VdHog1 function in a cascade that regulates microsclerotia formation and virulence, but not all VdHog1 dependent functions are VdPbs2 regulated. This study thus provides novel insights into the signal transduction mechanisms that regulate microsclerotia formation and pathogenesis in this fungus. PMID:27729908

  17. MADS-Box Transcription Factor VdMcm1 Regulates Conidiation, Microsclerotia Formation, Pathogenicity, and Secondary Metabolism of Verticillium dahliae

    PubMed Central

    Xiong, Dianguang; Wang, Yonglin; Tian, Longyan; Tian, Chengming

    2016-01-01

    Verticillium dahliae, a notorious phytopathogenic fungus, causes vascular wilt diseases in many plant species resulting in devastating yield losses worldwide. Due to its ability to colonize plant xylem and form microsclerotia, V. dahliae is highly persistent and difficult to control. In this study, we show that the MADS-box transcription factor VdMcm1 is a key regulator of conidiation, microsclerotia formation, virulence, and secondary metabolism of V. dahliae. In addition, our findings suggest that VdMcm1 is involved in cell wall integrity. Finally, comparative RNA-Seq analysis reveals 823 significantly downregulated genes in the VdMcm1 deletion mutant, with diverse biological functions in transcriptional regulation, plant infection, cell adhesion, secondary metabolism, transmembrane transport activity, and cell secretion. When taken together, these data suggest that VdMcm1 performs pleiotropic functions in V. dahliae. PMID:27536281

  18. Noncovalent Interactions in SIESTA Using the vdW-DF Functional: S22 Benchmark and Macrocyclic Structures.

    PubMed

    Carter, Damien J; Rohl, Andrew L

    2012-01-10

    We investigate the performance of the vdW-DF functional of Dion et al. implemented in the SIESTA code. In particular, the S22 data set and several calixarene-based host-guest structures are examined to assess the performance of the functional. The binding energy error statistics for the S22 data set reveal that the vdW-DF functional performs very well when compared to a range of other methods of treating dispersion in density functional theory, and to vdW-DF implementations in other codes. For the calixarene host-guest structures, the structural properties and binding energies are compared to previous experimental and computational studies, and in most cases we find that vdW-DF provides superior results to other computational studies.

  19. A long-period Cepheid variable in the starburst cluster VdBH222

    NASA Astrophysics Data System (ADS)

    Clark, J. S.; Negueruela, I.; Lohr, M. E.; Dorda, R.; González-Fernández, C.; Lewis, F.; Roche, P.

    2015-12-01

    Context. Galactic starburst clusters play a twin role in astrophysics, serving as laboratories for the study of stellar physics and also delineating the structure and recent star formation history of the Milky Way. Aims: In order to exploit these opportunities we have undertaken a spectroscopic survey of the red supergiant dominated young massive clusters thought to be present at both near and far ends of the Galactic Bar. Methods: Specifically, multi-epoch observations were employed to identify and investigate stellar variability and its potential role in initiating mass loss amongst the cool super-/hypergiant populations of these aggregates. Results: Significant spectroscopic variability suggestive of radial pulsations was found for the yellow supergiant VdBH 222 #505. Follow-up photometric investigations revealed modulation with a period of ~23.325 d; both timescale and pulsational profile are consistent with a Cepheid classification. Conclusions: #505 is one of the longest period Galactic cluster Cepheids identified to date and hence of considerable use in constraining the bright end of the period/luminosity relation at solar metallicities. In conjunction with extant photometry we infer a distance of ~6 kpc for VdBH222 and an age of ~20 Myr. This results in a moderate reduction in both the integrated cluster mass (~2×104M⊙) and the initial masses of the evolved cluster members (~10 M⊙). As such VdBH222 becomes an excellent test-bed for studying the properties of some of the lowest mass stars observed to undergo type-II supernovae. Moreover, the distance is in tension with a location of VdBH 222 at the far end of the Galactic Bar. Instead a birthsite in the near 3 kpc arm is suggested; providing compelling evidence of extensive recent star formation in a region of the inner Milky Way which has hitherto been thought to be devoid of such activity. Based on observations made at the European Southern Observatory, Paranal, Chile under programs ESO 093.D-0168.

  20. Within-population diversity of koala Chlamydophila pecorum at ompA VD1-VD3 and the ORF663 hypothetical gene.

    PubMed

    Higgins, D P; Beninati, T; Meek, M; Irish, J; Griffith, J E

    2012-05-04

    Infection of koalas by Chlamydophila pecorum is very common and causes significant morbidity, infertility and mortality. Fundamental to management of the disease is an understanding of the importance of multi-serotype infection or pathogen virulence in pathogenesis; these may need consideration in plans involving koala movement, vaccination, or disease risk assessment. Here we describe diversity of ompA VD1-3, and ORF663 hypothetical gene tandem repeat regions, in a single population of koalas with diverse disease outcomes. We PCR amplified and sequenced 72 partial ompA segments and amplified 25 tandem repeat segments (ORF663 hypothetical gene) from C. pecorum obtained from 62 koalas. Although several ompA genotypes were identified nationally, only one ompA genotype existed within the population studied, indicating that severe chlamydial disease occurs commonly in free-ranging koalas in the absence of infection by multiple MOMP serotypes of C. pecorum. In contrast, variation in tandem repeats within the ORF663 hypothetical gene was very high, approaching the entire range reported for pathogenic and non-pathogenic C. pecorum of European ruminants; providing an impetus for further investigation of this as a potential virulence trait.

  1. Hydrogen adsorption at the graphene surface: A vdW-DF perspective

    SciTech Connect

    Cooper, Valentino R; Ihm, Yungok; Morris, James R

    2012-01-01

    We use the recently developed van der Waals density functional (vdW-DF) along with the C09x exchange functional to explore the interactions of molecular hydrogen with a single sheet of graphene. Our calculations demonstrate the importance of the inclusion of dispersion interactions for evaluating the adsorption capacity of graphitic, sparsely packed materials. In particular we show that, although the commonly used local density approximation (LDA) exchange-correlation functional gives reasonable H$_2$-graphene separation distances, these interactions are in fact too strong and decrease too rapidly as the H$_2$-graphene distance increases. On the other hand, calculations employing the generalized gradient approximation (GGA) for exchange and correlation exhibit very little binding. The vdW-DF$^{\\rm C09x}$ functional, however, gives binding very similar to benchmark second-order M$\\o$ller-Plesset (MP2) theory results for the H$_2$-coronene interaction and has an appropriate long range interaction with the graphene sheet. This shortcoming of the LDA and GGA functionals is shown to have significant consequences on the overall adsorption densities of H$_2$ near the graphene, thus emphasizing the fundamental importance of properly characterizing the interactions of adsorbed molecules in porous media.

  2. A simple VD/VT gas-collection valve for use with Siemens ventilators.

    PubMed

    Ritz, R; Crogan, S

    1986-11-01

    An accurate knowledge of the ratio of physiologic dead space to tidal volume (VD/VT) is useful in managing mechanically ventilated patients. When collecting the sample of exhaled gases, one must separate the gas compressed in the ventilator circuit during inspiration from the gas exhaled by the patient. This is best accomplished by placing a separate gas-collection valve at the patient Y-piece, which will allow the patient's exhaled volumes to be collected separately. We designed a gas-collection valve for use with Siemens-Elema Servo 900B and 900C ventilators that performs this function over a wide range of ventilatory conditions. Our systems has several distinct advantages over the option provided by the manufacturer: Its economical cost represents significant savings, and it is more versatile than the Siemens gas analyzer. A larger variety of gas analyzers can be used for the measurement, and more accurate CO2 production values can be provided, along with directly determined VD/VT values.

  3. Spectroscopic and photometric characteristics of stars in the field of the cluster vdB 130

    NASA Astrophysics Data System (ADS)

    Tatarnikova, A. A.; Tatarnikov, A. M.; Sitnik, T. G.; Egorov, O. V.

    2016-12-01

    The observational data for 24 stars toward the young cluster vdB 130 are analyzed. The spectroscopic and photometric BV RIJHK observations have been carried out with the following telescopes: 6-m at the Special Astrophysical Observatory of the Russian Academy of Sciences, 60-cm at the Southern Station of the Moscow State University, and 2.5-m at the Caucasus Observatory of the Sternberg Astronomical Institute of theMoscow State University. Nine stars previously selected as cluster members have been found to belong to different subtypes of type B. A minimum color excess toward the cluster, E( B - V) = 0.9 mag, has been revealed for the vdB 130 stars lying outside the molecular cloud. Maximum color excesses, E( B - V) = 1.3-1.4 mag, have been found in the spectra of cluster stars 1r and 5r observed in dust blobs. Inside the cluster R v is shown to differ from the standard one. The overwhelming majority of the remaining investigated stars belong to late types and have minor color excesses (≤0.3) typical of close distances.

  4. van der Waals Density Functional Theory vdW-DFq for Semihard Materials

    NASA Astrophysics Data System (ADS)

    Peng, Qing; de, Suvranu

    There are a large number of materials with mild stiffness, which are not as soft as tissues and not as strong as metals. These semihard materials includes energetic materials, molecular crystals, layered materials, and van der Waals crystals. The integrity and mechanical stability are mainly determined by the interactions between instantaneously induced dipoles, the so called London dispersion force or van der Waals force. It is challenging to accurately model the structural and mechanical properties of these semihard materials in the frame of density functional theory where the non-local correlation functionals are not well known. Here we propose a van der Waals density functional named vdW-DFq to accurately model the density and geometry of semihard materials. Using β-cyclotetramethylene tetranitramine as a prototype, we adjust the enhancement factor of the exchange energy functional with generalized gradient approximations. We find this method to be simple and robust over a wide tuning range when calibrating the functional on-demand with experimental data. With a calibrated value q = 1 . 05 , the proposed vdW-DFq method shows good performance in predicting the geometries of 11 common energetic material molecular crystals and 3 typical layered van der Waals crystals. The authors would like to acknowledge the generous financial support from the Defense Threat Reduction Agency (DTRA) Grant # HDTRA1-13-1-0025.

  5. Bioavailability, rheology and sensory evaluation of fat-free yogurt enriched with VD3 encapsulated in re-assembled casein micelles.

    PubMed

    Levinson, Yonatan; Ish-Shalom, Sophia; Segal, Elena; Livney, Yoav D

    2016-03-01

    Vitamin D3 (VD3) deficiency is a global problem. Better ways are needed to enrich foods with this important nutraceutical. VD3 is fat-soluble, hence requiring a suitable vehicle for enriching nonfat foods. Our objectives were to assess the bioavailability of VD3, from fat-free yogurt, in re-assembled casein micelles (rCMs) compared to that in polysorbate-80 (PS80/Tween-80) a commonly used synthetic emulsifier, and to assess and compare their rheology and palatability. We enriched fat-free yogurt with VD3 loaded into either rCM (VD3-rCMs) or PS80 (VD3-PS80). In vivo VD3 bioavailability was evaluated by a large randomized, double blind, placebo-controlled clinical trial, measuring serum 25(OH)D increase in subjects who consumed fat-free yogurt with 50,000 IU of either VD3-rCM, VD3-PS80, or VD3-free placebo yogurt. Both VD3-rCM and VD3-PS80 increased the serum 25(OH)D levels by ∼8 ng ml(-1) and no significant differences in mean 25(OH)D levels were observed, evidencing the fact that VD3 bioavailability in rCM was as high as that in the synthetic emulsifier. VD3-rCM yogurt had a higher viscosity than VD3-PS80 yogurt. In sensory evaluations, panelists were able to discern between VD3-rCM and VD3-PS80 yogurt, and showed a dislike for PS80 yogurt, compared to rCM or the unenriched control. These results complement our past results showing higher protection against thermal treatment, UV irradiation, and deterioration during shelf life, conferred to hydrophobic nutraceuticals by rCM compared to that by the synthetic surfactant or to the unprotected bioactive, in showing the advantageous use of rCM over the synthetic emulsifier as a delivery system for the enrichment of food with VD3 and other hydrophobic nutraceuticals.

  6. van der Waals forces in density functional theory: a review of the vdW-DF method

    NASA Astrophysics Data System (ADS)

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-06-01

    A density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology is reviewed. The insights that led to the construction of the Rutgers-Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only for dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.

  7. van der Waals forces in density functional theory: a review of the vdW-DF method

    DOE PAGES

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; ...

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only formore » dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.« less

  8. van der Waals forces in density functional theory: a review of the vdW-DF method

    SciTech Connect

    Berland, Kristian; Cooper, Valentino R.; Lee, Kyuho; Schröder, Elsebeth; Thonhauser, T.; Hyldgaard, Per; Lundqvist, Bengt I.

    2015-05-15

    We review a density functional theory (DFT) that accounts for van der Waals (vdW) interactions in condensed matter, materials physics, chemistry, and biology. The insights that led to the construction of the Rutgers–Chalmers van der Waals density functional (vdW-DF) are presented with the aim of giving a historical perspective, while also emphasizing more recent efforts which have sought to improve its accuracy. In addition to technical details, we discuss a range of recent applications that illustrate the necessity of including dispersion interactions in DFT. This review highlights the value of the vdW-DF method as a general-purpose method, not only for dispersion bound systems, but also in densely packed systems where these types of interactions are traditionally thought to be negligible.

  9. ThP05 Biogeneration of Volatile Selenium Compounds in Biosolids/Biofuels and Quantification by VD/GC/ICPMS

    EPA Science Inventory

    A noval analytical approach that uses VD/GC/ICPMS for the on-line extraction and quantificationof volatile organopmetalloids is described. Several species of arsenic, selenium, antimony, bismuth and tellurium are amenable to this technique. Preliminary results of a study on the...

  10. Specific caspase inhibitor Q-VD-OPh prevents neonatal stroke in P7 rat: a role for gender.

    PubMed

    Renolleau, Sylvain; Fau, Sébastien; Goyenvalle, Catherine; Joly, Luc-Marie; Chauvier, David; Jacotot, Etienne; Mariani, Jean; Charriaut-Marlangue, Christiane

    2007-02-01

    Hypoxia-ischaemia in the developing brain results in brain injury with prominent features of apoptosis. In the present study, a third generation dipeptidyl broad-spectrum caspase inhibitor, quinoline-Val-Asp(Ome)-CH2-O-phenoxy (Q-VD-OPh), was tested in a model of unilateral focal ischaemia with reperfusion in 7-day-old rats. Q-VD-OPh (1 mg/kg, i.p.) reduced cell death, resulting in significant neuroprotection at 48 h of recovery (infarct volume of 12.6 +/- 2.8 vs. 24.3 +/- 2.2%, p = 0.006). The neuroprotective effects observed at 48 h post-ischaemia hold up at 21 days of survival time and attenuate neurological dysfunction. Analysis by gender revealed that females were strongly protected (6.7 +/- 3.3%, p = 0.006), in contrast to males in which there was no significant effect, when Q-VD-OPh was given after clip removal on the left common carotid artery. Immunoblot analysis demonstrated that Q-VD-OPh inhibits caspase 3 cleavage into its p17 active form and caspase 1 up-regulation and cleavage in vivo. Following ischaemia in P7 rats, males and females displayed different time course and pattern of cytochrome c release and active p17 caspase 3 during the first 24 h of recovery. In contrast, no significant difference was observed for caspase 1 expression between genders. These results indicate that ischaemia activates caspases shortly after reperfusion and that the sex of the animal may strongly influences apoptotic pathways in the pathogenesis of neonatal brain injury. The specificity, effectiveness, and reduced toxicity of Q-VD-OPh may determine the potential use of peptide-derived irreversible caspase inhibitors as promising therapeutics.

  11. Graphene-based vdW heterostructure Induced High-efficiency Thermoelectric Devices

    NASA Astrophysics Data System (ADS)

    Liang, Shijun; Ang, Lay Kee

    Thermoelectric material (TE) can convert the heat into electricity to provide green energy source and its performance is characterized by a figure of merit (ZT) parameter. Traditional TE materials only give ZT equal to around 1 at room temperature. But, it is believed that materials with ZT >3 will find wide applications at this low temperature range. Prior studies have implied that the interrelation between electric conductivity and lattice thermal conductivity renders the goal of engineering ZT of bulk materials to reach ZT >3. In this work, we propose a high-efficiency van del Waals (vdW) heterostructure-based thermionic device with graphene electrodes, which is able to harvest wasted heat (around 400K) based on the newly established thermionic emission law of graphene electrodes instead of Seebeck effect, to boost the efficiency of power generation over 10% around room temperature. The efficiency can be above 20% if the Schottky barrier height and cross-plane lattice thermal conductivity of transition metal dichacogenides (TMD) materials can be fine-engineered. As a refrigerator at 260 K, the efficiency is 50% to 80% of Carnot efficiency. Finally, we identify two TMD materials as the ideal candidates of graphene/TMD/graphene devices based on the state-of-art technology.

  12. A general optimization method applied to a vdW-DF functional for water

    NASA Astrophysics Data System (ADS)

    Fritz, Michelle; Soler, Jose M.; Fernandez-Serra, Marivi

    In particularly delicate systems, like liquid water, ab initio exchange and correlation functionals are simply not accurate enough for many practical applications. In these cases, fitting the functional to reference data is a sensible alternative to empirical interatomic potentials. However, a global optimization requires functional forms that depend on many parameters and the usual trial and error strategy becomes cumbersome and suboptimal. We have developed a general and powerful optimization scheme called data projection onto parameter space (DPPS) and applied it to the optimization of a van der Waals density functional (vdW-DF) for water. In an arbitrarily large parameter space, DPPS solves for vector of unknown parameters for a given set of known data, and poorly sampled subspaces are determined by the physically-motivated functional shape of ab initio functionals using Bayes' theory. We present a new GGA exchange functional that has been optimized with the DPPS method for 1-body, 2-body, and 3-body energies of water systems and results from testing the performance of the optimized functional when applied to the calculation of ice cohesion energies and ab initio liquid water simulations. We found that our optimized functional improves the description of both liquid water and ice when compared to other versions of GGA exchange.

  13. Surface composition and dynamical evolution of two retrograde objects in the outer solar system: 2008 YB3 and 2005 VD

    NASA Astrophysics Data System (ADS)

    Pinilla-Alonso, N.; Alvarez-Candal, A.; Melita, M. D.; Lorenzi, V.; Licandro, J.; Carvano, J.; Lazzaro, D.; Carraro, G.; Alí-Lagoa, V.; Costa, E.; Hasselmann, P. H.

    2013-02-01

    Most of the objects in the trans-Neptunian belt (TNb) and related populations move in prograde orbits with low eccentricity and inclination. However, the list of icy minor bodies moving in orbits with an inclination above 40° has increased in recent years. The origin of these bodies, and in particular of those objects in retrograde orbits, is not well determined, and different scenarios are considered, depending on their inclination and perihelion. In this paper, we present new observational and dynamical data of two objects in retrograde orbits, 2008 YB3 and 2005 VD. We find that the surface of these extreme objects is depleted of ices and does not contain the "ultra-red" matter typical of some Centaurs. Despite small differences, these objects share common colors and spectral characteristics with the Trojans, comet nuclei, and the group of grey Centaurs. All of these populations are supposed to be covered by a mantle of dust responsible for their reddish-to-neutral color. To investigate if the surface properties and dynamical evolution of these bodies are related, we integrate their orbits for 108 years to the past. We find a remarkable difference in their dynamical evolutions: 2005 VD's evolution is dominated by a Kozai resonance with planet Jupiter while that of 2008 YB3 is dominated by close encounters with planets Jupiter and Saturn. Our models suggest that the immediate site of provenance of 2005 VD is the in the Oort Cloud, whereas for 2008 YB3 it is in the trans-Neptunian region. Additionally, the study of their residence time shows that 2005 VD has spent a larger lapse of time moving in orbits in the region of the giant planets than 2008 YB3. Together with the small differences in color between these two objects, with 2005 VD being more neutral than 2008 YB3, this fact suggests that the surface of 2005 VD has suffered a higher degree of processing, which is probably related to cometary activity episodes. Partially based on observations made with ESO

  14. Adsorption of pentacene on (100) vicinal surfaces: role of coordination, surface chemistry and vdWs effects

    NASA Astrophysics Data System (ADS)

    Matos, Jeronimo; Kara, Abdelkader

    2015-03-01

    In contrast to low miller index surfaces, vicinal surfaces are characterized by steps and step edges that not only present an interesting atomic landscape for the adsorption organic molecules, but also a unique electronic structure resulting in part from the low coordinated atoms at the step edges. The adsorption of pentacene on the stepped (511), (711), (911) surfaces (respectively 3, 4 and 5-atom wide terraces) of Cu and Ag (coinage transition metals); Pt (reactive transition metal); and Ni (reactive, magnetic transition metal) are studied using density functional theory, in order to investigate the support effects arising from differing surface chemistry. We compare the adsorption energy, adsorption geometry and electronic structure predicted by the PBE functional with those obtained from one of the optimized vdW-DF methods: optB88-vdW. Work supported by the U.S. Department of Energy Basic Energy Science under Contract No. DE-FG02-11ER16243.

  15. Structural, energetic and electrical properties of encapsulation of penicillamine drug into the CNTs based on vdW-DF perspective

    NASA Astrophysics Data System (ADS)

    Khorsand, Ameneh; Jamehbozorgi, Saeid; Ghiasi, Reza; Rezvani, Mahyar

    2015-08-01

    First-principles van der Waals density functional (vdW-DF) calculation using GGA/PBE functional and DZP basis set implemented in the SIESTA package was carried out to investigation the encapsulation of penicillamine drug into the both armchair and zigzag single wall carbon nanotubes (SWCNTs). The results reveal that the drug encapsulated inside the CNT cavity is weakly bounded. The obtained results of binding energies indicated that incorporation of drug is favored inside the zigzag SWCNTs compared with armchair counterparts. We address here the role of vdW interaction for penicillamine drug when inclusion in the CNTs. It worth mentioning that encapsulation of vdW forces can be effects on the binding properties. The electronic structures and Mulliken charge population are analysed for the energetically most favorable complexes which shows that encapsulated penicillamine changes slightly the electronic properties of SWCNTs and trivial charges are transferred from drug to CNTs during encapsulation process. Global reactivity descriptor values such as electronegativity (χ), global hardness (η), global softness (S), electronic chemical potential (μ), and electrophilicity index (ω) were calculated. We anticipated that these findings supply the new way and value information for help in the experimental study and future applications.

  16. NO serves as a signaling intermediate downstream of H₂O₂ to modulate dynamic microtubule cytoskeleton during responses to VD-toxins in Arabidopsis.

    PubMed

    Yao, Lin-Lin; Pei, Bao-Lei; Zhou, Qun; Li, Ying-Zhang

    2012-02-01

    Although hydrogen peroxide (H₂O₂) and nitric oxide (NO) can act as an upstream signaling molecule to modulate the dynamic microtubule cytoskeleton during the defense responses to Verticillium dahliae (VD) toxins in Arabidopsis, it is not known the relationship between these two signaling molecules. Here, we show that VD-toxin-induced NO accumulation was dependent on prior H₂O₂ production, NO is downstream of H₂O₂ in the signaling process, and that H₂O₂ acted synergistically with NO to modulate the dynamic microtubule cytoskeleton responses to VD-toxins in Arabidopsis.

  17. C. elegans fmi-1/flamingo and Wnt pathway components interact genetically to control the anteroposterior neurite growth of the VD GABAergic neurons.

    PubMed

    Huarcaya Najarro, Elvis; Ackley, Brian D

    2013-05-01

    Directed axonal growth is essential to establish neuronal networks. During the early development of the VD neurons, an anterior neurite that will become the VD axon extends along the anteroposterior (A/P) axis in the ventral nerve cord (VNC) in Caenorhabditis elegans. Little is known about the cellular and molecular mechanisms that are important for correct neurite growth in the VNC. In fmi-1/flamingo mutant animals, we observed that some postembryonically born VD neurons had a posterior neurite instead of a normal anterior neurite, which caused aberrant VD commissure patterning along the A/P axis. In addition, VD anterior neurites had underextension defects in the VNC in fmi-1 animals, whereas VD commissure growth along the dorsoventral (D/V) axis occurred normally in these animals, suggesting that fmi-1 is important for neurite growth along the A/P axis but not the D/V axis. We also uncovered unknown details of the early development of the VD neurons, indicating that the neurite defects arose during their early development. Interestingly, though fmi-1 is present at this time in the VNC, we did not observe FMI-1 in the VD neurons themselves, suggesting that fmi-1 might be working in a cell non-autonomous fashion. Furthermore, fmi-1 appears to be working in a novel pathway, independently from the planar cell polarity pathway and in parallel to lin-17/frizzled and dsh-1/dishevelled, to determine the direction of neurite growth. Our findings indicate that redundant developmental pathways regulate neurite growth in the VNC in C. elegans.

  18. Field evaluations of the VD max approach for substantiation of a 25 kGy sterilization dose and its application to other preselected doses

    NASA Astrophysics Data System (ADS)

    Kowalski, John B.; Herring, Craig; Baryschpolec, Lisa; Reger, John; Patel, Jay; Feeney, Mary; Tallentire, Alan

    2002-08-01

    The International and European standards for radiation sterilization require evidence of the effectiveness of a minimum sterilization dose of 25 kGy but do not provide detailed guidance on how this evidence can be generated. An approach, designated VD max, has recently been described and computer evaluated to provide safe and unambiguous substantiation of a 25 kGy sterilization dose. The approach has been further developed into a practical method, which has been subjected to field evaluations at three manufacturing facilities which produce different types of medical devices. The three facilities each used a different overall evaluation strategy: Facility A used VD max for quarterly dose audits; Facility B compared VD max and Method 1 in side-by-side parallel experiments; and Facility C, a new facility at start-up, used VD max for initial substantiation of 25 kGy and subsequent quarterly dose audits. A common element at all three facilities was the use of 10 product units for irradiation in the verification dose experiment. The field evaluations of the VD max method were successful at all three facilities; they included many different types of medical devices/product families with a wide range of average bioburden and sample item portion values used in the verification dose experiments. Overall, around 500 verification dose experiments were performed and no failures were observed. In the side-by-side parallel experiments, the outcomes of the VD max experiments were consistent with the outcomes observed with Method 1. The VD max approach has been extended to sterilization doses >25 and <25 kGy; verification doses have been derived for sterilization doses of 15, 20, 30, and 35 kGy. Widespread application of the VD max method for doses other than 25 kGy must await controlled field evaluations and the development of appropriate specifications/standards.

  19. The mitogen-activated protein kinase gene, VdHog1, regulates osmotic stress response, microsclerotia formation and virulence in Verticillium dahliae.

    PubMed

    Wang, Yonglin; Tian, Longyan; Xiong, Dianguang; Klosterman, Steven J; Xiao, Shuxiao; Tian, Chengming

    2016-03-01

    The fungus Verticillium dahliae has gained worldwide notoriety as a destructive plant pathogen, causing vascular wilt diseases on diverse plant species. V. dahliae produces melanized resting bodies, known as microsclerotia, which can survive for 15 years in the soil, and are thus critically important in its disease cycle. However, the molecular mechanisms that underpin microsclerotia formation, survival, and germination remain poorly understood. In this study, we observed that deletion of VdHog1 (ΔVdHog1), encoding a homolog of a high-osmolarity glycerol (HOG) response mitogen-activated protein kinase, displayed decreased numbers of melanized microsclerotia in culture, heightened sensitivity to hyperosmotic stress, and increased resistance to the fungicide fludioxonil. Through RNA-Seq analysis, we identified 221 genes differentially expressed in the ΔVdHog1 strain. Interestingly, the expression levels of genes involved in melanin biosynthesis, as well as the hydrophobin gene VDH1, involved in the early stage of microsclerotia formation, were significantly decreased in the ΔVdHog1 strains relative to the wild-type expression levels. The ΔVdHog1 strains exhibited decreased virulence relative to the wild type strain on smoke tree seedlings. These results indicate that VdHog1 regulates hyperosmotic stress responses in V. dahliae, and establishes the Hog1-mediated pathway as a target to further probe the up- and downstream processes that regulate asexual development in this fungus.

  20. VdCYC8, Encoding CYC8 Glucose Repression Mediator Protein, Is Required for Microsclerotia Formation and Full Virulence in Verticillium dahliae.

    PubMed

    Li, Zhi-Fang; Liu, Yi-Jie; Feng, Zi-Li; Feng, Hong-Jie; Klosterman, Steven J; Zhou, Fang-Fang; Zhao, Li-Hong; Shi, Yong-Qiang; Zhu, He-Qin

    2015-01-01

    Verticillium dahliae is the primary causal agent for Verticillium wilt disease on a diverse array of economically important crops, including cotton. In previous research, we obtained the low-pathogenicity mutant T286 from the T-DNA insertional mutant library of the highly virulent isolate Vd080 derived from cotton. In this study, the target disrupted gene VdCYC8 was identified by TAIL-PCR, encoding a homolog of CYC8 proteins involved in glucose repression. The deletion mutant ΔCYC8 exhibited several developmental deficiencies, including reduced microsclerotia formation, reduced sporulation, and slower growth. Moreover, compared with the wild type strain Vd080, the pathogenicity of strain ΔCYC8 was significantly decreased on cotton seedlings. However, the complementary mutants ΔCYC8-C led to restoration of the wild type phenotype or near wild type levels of virulence on cotton. Interestingly, pathogenicity of the strains was correlated with VdCYC8 gene expression levels in complemented mutants. Gene expression analyses in the wild type strain Vd080, the ΔCYC8-45 strain, and complemented strain ΔCYC8-C26 indicated that VdCYC8 regulates the transcription levels of several genes in V. dahliae that have roles in melanin and production.

  1. VizieR Online Data Catalog: Photometry of VdBH 222 stars and field stars (Marco+, 2014)

    NASA Astrophysics Data System (ADS)

    Marco, A.; Negueruela, I.; Gonzalez-Fernandez, C.; Maiz Apellaniz, J.; Dorda, R.; Clark, J. S.

    2014-05-01

    We obtained UBVR photometry of VdBH 222 using the ESO Faint Object Spectrograph and Camera (EFOSC2) on the NTT on the night of 24 June 2012. The instrument was equipped with CCD#40, which is a Loral/Lesser, thinned, AR-coated, UV-flooded, and MPP chip that is controlled by ESO-FIERA. It covers a field of view of and 4.1'x4.1' and has a pixel scale of 0.12". The JHK images were obtained using the Son OF Isaac (SOFI) near-IR spectrograph and camera on the NTT on 13 July 2008, equipped with a CCD providing a pixel scale of 0.288arcsec and an field of view of 4.92x4.95' (4 data files).

  2. Lightcurve Photometry of NEAs 4450 Pan, (170891) 2004 TY16 2002 RC118, and 2007 VD12

    NASA Astrophysics Data System (ADS)

    Carbognani, Alberto

    2008-09-01

    Lightcurve periods and amplitudes are reported for Amor asteroid (170891) 2004 TY16 (P = 2.795 ± 0.002 h; A = 0.2 ± 0.02 mag), Amor asteroid 2002 RC118 (P = 9.98 ± 0.02 h; A = 0.4 ± 0.03 mag), and Apollo PHA 2007 VD12 (P = 7.418 ± 0.005 h; A = 0.6 ± 0.05 mag). For 4450 Pan it was not possible to establish a period, but we were able to determine color indices, absolute magnitude, and diameter. A search for a cometary activity of 2002 RC118 was made with negative results.

  3. The role of vdW interactions in coverage dependent adsorption energies of atomic adsorbates on Pt(111) and Pd(111)

    NASA Astrophysics Data System (ADS)

    Thirumalai, Hari; Kitchin, John R.

    2016-08-01

    Adsorption, a fundamental process in heterogeneous catalysis is known to be dependent on the adsorbate-adsorbate and surface-adsorbate bonds. van der Waals (vdW) interactions are one of the types of interactions that have not been examined thoroughly as a function of adsorbate coverage. In this work we quantify the vdW interactions for atomic adsorbates on late transition metal surfaces, and determine how these long range forces affect the coverage dependent adsorption energies. We calculate the adsorption energies of carbon, nitrogen, oxygen, sulfur, fluorine, bromine and chlorine species on Pt(111) and Pd(111) at coverages ranging from 1/4 to 1 ML using the BEEF-vdW functional. We observe that adsorption energies remain coverage dependent, and this coverage dependence is shown to be statistically significant. vdW interactions are found to be coverage dependent, but more significantly, they are found to be dependent on molecular properties such as adsorbate size, and consequently, correlate with the adsorbate effective nuclear charge. We observe that these interactions account for a reduction in the binding energy of the system, due to the destabilizing attractive interactions between the adsorbates which weaken its bond with the surface.

  4. VdCYC8, encoding CYC8 glucose repression mediator protein, is required for microsclerotia formation and full virulence in Verticillium dahliae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium dahliae is the primary causal agent for Verticillium wilt disease on a diverse array of economically important crops, including cotton. In previous research, we screened a T-DNA insertional mutant library of the highly virulent isolate Vd080 derived from cotton. In this study, the targ...

  5. A cupin domain-containing protein with a quercetinase activity (VdQase) regulates Verticillium dahliae's pathogenicity and contributes to counteracting host defenses

    PubMed Central

    El Hadrami, Abdelbasset; Islam, Md. Rashidul; Adam, Lorne R.; Daayf, Fouad

    2015-01-01

    We previously identified rutin as part of potato root responses to its pathogen Verticillium dahliae. Rutin was directly toxic to the pathogen at doses greater than 160 μM, a threshold below which many V. dahliae pathogenicity-related genes were up-regulated. We identified and characterized a cupin domain-containing protein (VdQase) with a dioxygenase activity and a potential role in V. dahliae-potato interactions. The pathogenicity of VdQase knock-out mutants generated through Agrobacterium tumefasciens-mediated transformation was significantly reduced on susceptible potato cultivar Kennebec compared to wild type isolates. Fluorescence microscopy revealed a higher accumulation of flavonols in the stems of infected potatoes and a higher concentration of rutin in the leaves in response to the VdQase mutants as compared to wild type isolates. This, along with the HPLC characterization of high residual and non-utilized quercetin in presence of the knockout mutants, indicates the involvement of VdQase in the catabolism of quercetin and possibly other flavonols in planta. Quantification of Salicylic and Jasmonic Acids (SA, JA) in response to the mutants vs. wild type isolates revealed involvement of VdQase in the interference with signaling, suggesting a role in pathogenicity. It is hypothesized that the by-product of dioxygenation 2-protocatechuoylphloroglucinolcarboxylic acid, after dissociating into phloroglucinol and protocatechuoyl moieties, becomes a starting point for benzoic acid and SA, thereby interfering with the JA pathway and affecting the interaction outcome. These events may be key factors for V. dahliae in countering potato defenses and becoming notorious in the rhizosphere. PMID:26113857

  6. A fully consistent spin formalism for the nonempirical van der Waals density functional vdW-DF

    NASA Astrophysics Data System (ADS)

    Thonhauser, T.; Zuluaga, S.; Arter, C.; Berland, K.; Schröder, E.; Hyldgaard, P.

    We present a proper nonempirical spin-density formalism for the van der Waals density functional (vdW-DF) method. We show that this generalization, termed svdW-DF, is firmly rooted in the single-particle nature of exchange and we test it on a range of spin systems. We investigate in detail the role of spin in the van der Waals driven adsorption of H2 and CO2 in the linear magnets Mn-MOF74, Fe-MOF74, Co-MOF74, and Ni-MOF74. In all cases, we find that spin plays a significant role during the adsorption process despite the general weakness of the molecular-magnetic responses. The case of CO2 adsorption in Ni-MOF74 is particularly interesting, as the inclusion of spin effects results in an increased attraction, opposite to what the diamagnetic nature of CO2 would suggest. We explain this counter-intuitive result, tracking the behavior to a coincidental hybridization of the O p states with the Ni d states in the down-spin channel. More generally, by providing insight on van der Waals interactions in concert with spin effects, our nonempirical svdW-DF method opens the door for a deeper understanding of weak nonlocal magnetic interactions. Work supported by DOE DE-FG02-08ER46491 and NSF DMR-1145968.

  7. Structural and ionic conductivity studies of electrospun polymer blend P(VdF-co-HFP)/PMMA electrolyte membrane for lithium battery application

    SciTech Connect

    Padmaraj, O.; Satyanarayana, N.; Venkateswarlu, M.

    2015-06-24

    A novel fibrous polymer blend [(100-x) % P(VdF-co-HFP)/x % PMMA, x = 10, 20, 30, 40, 50] electrolyte membranes were prepared by electrospinning technique. Structural, thermal and surface morphology of all the compositions of electrospun polymer blend membranes were studied by using XRD, DSC & SEM. The newly developed five different compositions of polymer blend fibrous electrolyte membranes were obtained by soaking in an electrolyte solution contains 1M LiPF{sub 6} in EC: DEC (1:1,v/v). The wet-ability and conductivity of all the compositions of polymer blend electrolyte membranes are evaluated through electrolyte uptake and impedance measurements. The polymer blend [90% P(VdF-co-HFP)/10% PMMA] electrolyte membrane showed good wet-ability and high conductivity (1.788 × 10{sup −3} Scm{sup −1}) at room temperature.

  8. In-depth proteomic analysis of Varroa destructor: Detection of DWV-complex, ABPV, VdMLV and honeybee proteins in the mite

    PubMed Central

    Erban, Tomas; Harant, Karel; Hubalek, Martin; Vitamvas, Pavel; Kamler, Martin; Poltronieri, Palmiro; Tyl, Jan; Markovic, Martin; Titera, Dalibor

    2015-01-01

    We investigated pathogens in the parasitic honeybee mite Varroa destructor using nanoLC-MS/MS (TripleTOF) and 2D-E-MS/MS proteomics approaches supplemented with affinity-chromatography to concentrate trace target proteins. Peptides were detected from the currently uncharacterized Varroa destructor Macula-like virus (VdMLV), the deformed wing virus (DWV)-complex and the acute bee paralysis virus (ABPV). Peptide alignments revealed detection of complete structural DWV-complex block VP2-VP1-VP3, VDV-1 helicase and single-amino-acid substitution A/K/Q in VP1, the ABPV structural block VP1-VP4-VP2-VP3 including uncleaved VP4/VP2, and VdMLV coat protein. Isoforms of viral structural proteins of highest abundance were localized via 2D-E. The presence of all types of capsid/coat proteins of a particular virus suggested the presence of virions in Varroa. Also, matches between the MWs of viral structural proteins on 2D-E and their theoretical MWs indicated that viruses were not digested. The absence/scarce detection of non-structural proteins compared with high-abundance structural proteins suggest that the viruses did not replicate in the mite; hence, virions accumulate in the Varroa gut via hemolymph feeding. Hemolymph feeding also resulted in the detection of a variety of honeybee proteins. The advantages of MS-based proteomics for pathogen detection, false-positive pathogen detection, virus replication, posttranslational modifications, and the presence of honeybee proteins in Varroa are discussed. PMID:26358842

  9. PETN, RDX, HMX, TATB: band gap dependence on pressure under hydrostatic compression from DFT with GW and vdW corrections

    NASA Astrophysics Data System (ADS)

    Mukhanov, Andrei; Yanilkin, Alexei

    2014-03-01

    In the middle of 1990s Gilman (Gilman J. J. 1995 Phil. Mag. B, 71:6, 1057) proposed the idea that explosives transit from insulator to conductor state with following adiabatic expansion of free electrons in shockwave. One of the reasons of such a behavior of electrons is narrowing or disappearing of the fundamental band gap in explosive single crystal. It is well known that similar behavior can be simulated by DFT. But there is a severe problem of lowering the value of gap by DFT. So for quantitative prediction of narrowing of gap under pressure it is necessary to use more complicated methods like GW. From first principle calculations we determined elastic moduli for ideal crystals of PETN, RDX, HMX, and TATB. Accounting for those moduli we simulated the 0 K isotherms for hydrostatic compression of single crystal. Due to the essential role of van der Waals interaction in such materials the vdW corrections to DFT in Grimme's form was used. We obtained the dependencies for band gap on pressure under hydrostatic compression. Our preliminary results on GW calculations show that for TATB at initial uncompressed volume we have the value of gap twice a bigger in GW than in DFT.

  10. Nuclear Zero Point Effects as a Function of Density in Ice-like Structures and Liquid Water from vdW-DF Ab Initio Calculations

    NASA Astrophysics Data System (ADS)

    Pamuk, Betül; Allen, Philip B.; Soler, Jose M.; Fernández-Serra, Marivi

    2014-03-01

    The contributions of nuclear zero point vibrations to the structures of liquid water and ice are not negligible. Recently, we have explained the source of an anomalous isotope shift in hexagonal ice, representing itself as an increase in the lattice volume when H is replaced by D, by calculating free energy within the quasiharmonic approximation, with ab initio density functional theory. In this work, we extend our studies to analyze the zero point effect in other ice-like structures under different densities: clathrate hydrates, LDL and HDL-like amorphous ices with different densities, and a highly dense ice phase, ice VIII. We show that there is a transition from anomalous isotope effect to normal isotope effect as the density increases. We also analyze nuclear zero point effects in liquid water using different vdW-DFs and make connections to this anomalous-normal isotope effect transition in ice. This work is supported by DOE Early Career Award No. DE-SC0003871.

  11. C. elegans fmi-1/flamingo and Wnt pathway components interact genetically to control the anteroposterior neurite growth of the VD GABAergic neurons.

    PubMed

    Ackley, Brian D

    2013-07-01

    During development, multiple environmental cues, e.g., growth factors, cell adhesion molecules, etc., interact to influence the pattern of outgrowth of axons and dendrites in a cell-specific fashion. As a result, individual neurons may receive similar signals, but make unique choices, leading to distinct wiring within the nervous system. C. elegans has been useful in identifying molecular cues that influence neuronal development, as well as the downstream mechanisms that allow individual neurons to make cell-specific responses. Recently, we described a role for the conserved cadherin domain-containing protein, FMI-1/flamingo, in multiple stages of neural development in C. elegans. During the initial phase of neurite outgrowth, FMI-1 seems to have a relatively cell-specific effect on the VD neurons to promote the initial neurite formed to grow toward the anterior. In this capacity, FMI-1 appears to work coordinately with at least two Wnt ligands, EGL-20 and LIN-44, and multiple downstream Wnt signaling components (including LIN-17/Frizzled, DSH-1/Disheveled, and BAR-1/β-catenin). Here I will discuss some of the ideas we considered about how FMI-1 could affect neurons as they acquire their morphology during development.

  12. VD: Facts You Should Know.

    ERIC Educational Resources Information Center

    Blanzaco, Andre; And Others

    This booklet presents information about venereal disease to the student in a simple, step-by-step way. It includes at least one question box on almost every page, requiring the reader to become actively involved with the material which is presented. The booklet is made up of seven sections, and is accompanied by a separate booklet which contains…

  13. [Quality management in a combined clinic - the quality management system according to DIN EN ISO 9001 of the The German Association of Spa Accommodation Resorts e. V. (VdKB)].

    PubMed

    Eckert, H; Schulze, U

    2004-06-01

    The implementation of a quality system in health care organizations offers huge potentials for improvement and development. But the realization of such systems necessitates high investments, which small companies and family businesses often are unable to raise. The German Association of Spa Accommodation Resorts (VdKB) commissioned two consultants to develop a reasonably priced implementation concept of a DIN EN ISO 9001 quality system specially adjusted to small companies and family businesses in medical spa and rehabilitation services, which was successfully accredited in May 2003. This paper describes fundamental requirements in combine management systems, considers the pros and cons of management combines and demonstrates the practical realization of combine requirements on the example of the VdKB-combine system.

  14. Waging War on V.D.

    ERIC Educational Resources Information Center

    Yarber, William L.

    1978-01-01

    Describes the characteristics and treatments of the most prevalent sexually transmissable diseases in the United States. Advocates a junior high-senior high health education program to cope with the diseases. (CP)

  15. Cohesion and Semantics. Reports on Text Linguistics. Meddelanden Fran Stiftelsens for Abo Akademi Forskningsinstitut, Nr 41.

    ERIC Educational Resources Information Center

    Ostman, Jan-Ola, Ed.

    This collection of papers on semantics and cohesion is organized into two sections: Meaning and Semantics, and Textual Cohesion. Titles and authors are as follows: "Functional Text Semantics, Idioms, and Variability" (Jan-Ola Ostman); "On the Degree of Motivation in Signs Used in Metaphors Involving Plant Symbolism" (Ralf…

  16. Foreign Language Learning and Bilingualism. Publications of the Research Institute of the ABO Akademi Foundation NR 105.

    ERIC Educational Resources Information Center

    Ringbom, Hakan, Ed.

    This collection of six essays and one bibliography on second language learning includes: (1) "Transfer in Relation to Some Other Variables in L2-Learning" (Hakan Ringbom); (2) "Word Frequencies in Finnish and Finland-Swedish Learner Language" (Hakan Ringbom); (3) "The Influence of Swedish on the English of Finnish…

  17. Farm Water Supply and Sanitation--Pipe, Plumbing, Skills and Symbols. Student Materials. V.A. III. V-D-1, V-D-2.

    ERIC Educational Resources Information Center

    Texas A and M Univ., College Station. Vocational Instructional Services.

    Designed for use by individuals enrolled in vocational agricultural classes, these student materials deal with farm water supply, sanitation, and plumbing skills. Topics covered in the unit are maintaining the farm water supply; repairing faucets and valves, leaks in pipes and storage tanks, and water closets; clearing clogged drains and traps;…

  18. VizieR Online Data Catalog: Astrometry of 3 vdBH open clusters (Orellana+, 2015)

    NASA Astrophysics Data System (ADS)

    Orellana, R. B.; de Biasi, M. S.; Paiz, L. G.; Bustos Fierro, I. H.; Calderon, J. H.

    2015-07-01

    The astrometric data used in this paper, stellar position and proper motion, come from the UCAC4 Catalogue with positions over 113 million stars and 105 million of them with proper motions. (7 data files).

  19. The VD Epidemic. How It Started, Where It's Going, and What to Do About It.

    ERIC Educational Resources Information Center

    Lasagna, Louis

    This book concerning the venereal disease epidemic is designed to do the following two things: (1) to give the general public straightforward, explicit information on this ancient disease; and (2) to transform the current mood of complacency into a demand that eradication programs be set in motion at once. This book is all-encompassing in scope…

  20. Health Occupations Education I. Module No. V-A to V-D.

    ERIC Educational Resources Information Center

    Dunmeyer, Kathryn; And Others

    This set of 4 modules on bedmaking is 1 of 11 sets in the Health Occupations Education I instructional package for the first year of a 2-year course of study. The materials are designed to prepare students through individualized instruction for entry-level job opportunities on health care teams in a variety of practice settings. Each module may…

  1. Sitzungsberichte der Heidelberger Akademie der Wissenschaften> " Jahrgang 1990 Sitzungsber.Heidelberg 90 " "Gott hat die Natur einfältig gemacht, sie aber suchen viel Künste"

    NASA Astrophysics Data System (ADS)

    Zehe, Horst

    Der Aufsatz demonstriert anhand ausgiebig kommentierter zeitgenössischer Zeugnisse Goethes Reaktion auf die Arbeiten Fraunhofers, insbesondere auf die Entdeckung der dunklen Linien im Sonnenspektrum. Den Fehlurteilen Goethes werden dabei die Urteile zeitgenössischer Physiker wie Chladni und J.F.W. Herschel gegenübergestellt. Bislang noch ungedruckte Dokumente aus dem Weimarer Goethe- und Schiller-Archiv belegen, daß sich Goethe nicht nur literarisch mit Fraunhofer beschäftigte, sondern daß er auch dessen Versuche mit Hilfe des Jenaer Universitätsmechanikers Körner getreulich zu wiederholen suchte.

  2. Psycholinguistics and Foreign Language Learning. Papers from a Conference (Stockholm, Sweden and Abo, Finland, October 25-26, 1982). Meddelanden fran Stiftelsens for Abo Akademi Forskningsinstitut Nr.86.

    ERIC Educational Resources Information Center

    Ringbom, Hakan, Ed.

    At irregular intervals, beginning in 1977, Swedish-Finnish conferences on contrastive and applied linguistics have been arranged in Stockholm and Turko/Abo. This volume presents most of the papers given at the 1982 conference. Papers include: "Free Recall of Mixed Language Lists. Error Patterns in Bilingual Memory" (Karin Aronsson, Anja Metsola,…

  3. Study on the Interaction Coefficients in PR Equation with vdW Mixing Rules for HFC and HC Binary Mixtures

    NASA Astrophysics Data System (ADS)

    Chen, Jian-Xin; Hu, Peng; Chen, Ze-Shao

    2008-12-01

    The Peng-Robinson equation of state with the van der Waals mixing rules was used to correlate vapor-liquid equilibrium (VLE) data for HFC/HC, HFC/HFC, and HC/HC binary mixtures. The interaction parameter k ij was obtained for every binary mixture. It was assumed that k ij has contributions from the two components, and each component has its own constant contribution factor k i for the mixture, and the values of k ij indicate the degree in difference of properties between the two components. Therefore, the interaction parameters k ij is proposed as: k ij = k i - k j . The values of the mixing factor k i for Hydrofluorocarbons (HFCs) and Hydrocarbons (HCs), including propane, isobutane, n-butane, R23, R32, R125, R143a, R134a, R152a, R227ea R236fa, R236ea, and R245fa, were obtained by least-square fitting. In total, 39 refrigerant binary mixtures were analyzed on the basis of this method, and the results showed good agreement with experimental data. The overall average absolute deviations of pressure and vapor mole fraction are 1.3 % and 0.0089, respectively.

  4. New spreading law of thin film liquids controlled by gravity and vdW forces under thermal fluctuations

    NASA Astrophysics Data System (ADS)

    Nesic, Svetozar; Cuerno Rejado, Rodolfo; Moro Egido, Esteban

    2013-11-01

    It has been shown that, in the regime controlled by surface tension, the spreading dynamics of a thin viscous fluid droplet changes significantly when it is subjected to thermal fluctuations. Technically, this has been accomplished through the incorporation of appropriate stochastic terms into the standard lubrication equation. In practice, it leads to a modification of the classic Tanner's law for spreading, with implications for Micro and Nanofluidic systems. We have recently found a new law of spreading for the same kind of systems, but in the gravity-dominated regime. Moreover, in the deteministic case a finite contact angle is formed when a van der Waals attractive force is introduced to the system and we show that there is a slight change in contact angle when thermal fluctuations are taken into account. Ph.D student and a member of GISC (http://matematicas.uc3m.es/index.php/gisc).

  5. Millimeter-Wave Spectroscopy of the vdW Bands of He-HCN Near the Dissociation Limit.

    NASA Astrophysics Data System (ADS)

    Harada, Kensuke; Tanaka, Keiichi

    2010-06-01

    The He-HCN complex is a weakly bound complex with binding energy of about 9 cm-1. We have measured the internal rotation bands (to the j = 1 and 2 states) and intermolecular stretching bands of the He-HCN complex by millimeter-wave absorption spectroscopy combined with a pulsed-jet expansion technique, and reported the potential energy surface (PES) to reproduce the observed transition frequencies. The PES obtained has a global minimum in the linear configuration with a depth of 30.3 cm-1 and has a saddle point at the anti-linear configuration with a depth of 20.3 cm-1. The intermolecular stretching level and the second excited (j = 2) level of the internal rotation state are determined to be located 9.1407 and 9.0529 cm-1, respectively, above the ground state, very close to the calculated dissociation limit (D_0) of 9.33 cm-1 . In the present study, we have extended the measurement to the transitions to the bound states above the "dissociation limit" (D_0) and observed several such transitions for the first time in the ground state of the molecular complex. The rovibrational levels of He-HCN with e label dissociate to the HCN molecule with J=0 and the He atom (D_0), while those with f label, due to the parity conservation, to the HCN molecule with J=1 and the He atom which is higher in energy by about 2BHCN ˜ 2.96 cm-1 than D_0, as discussed in the infrared study of He-HF. The PES obtained in the present analysis indicates that four f levels in the j = 1 and 2 excited states are bound above the "dissociation limit" (D_0) due to the parity conservation. In addition five levels (both of e and f labels) are predicted to be bound by centrifugal barrier with finite life times but not yet observed. K. Harada, K. Tanaka, T. Tanaka, S. Nanbu, and M. Aoyagi, J. Chem. Phys. 117, 7041 (2002). C. M. Lovejoy and D. J. Nesbitt, J. Chem. Phys. 93, 5387 (1990).

  6. Deuteron frozen-spin- polarized target for nd experiments at the VdG accelerator of Charles University

    NASA Astrophysics Data System (ADS)

    Borisov, N. S.; Bazhanov, N. A.; Belyaev, A. A.; Brož, J.; Černý, J.; Doležal, Z.; Fedorov, A. N.; Gurevich, G. M.; Ivanov, M. P.; Kodyš, P.; Kubík, P.; Kuzmin, E. S.; Lazarev, A. B.; Lehar, F.; Lukhanin, O. O.; Matafonov, V. N.; Neganov, A. B.; Pisarev, I. L.; Švejda, J.; Shilov, S. N.; Usov, Yu. A.; Wilhelm, I.

    2008-08-01

    A frozen-spin- polarized deuteron target cooled by the 3He/ 4He dilution refrigerator is described. Fully deuterated 1,2-propanediol was used as a target material. Deuteron vector polarization about 40% was obtained for the target in the shape of a cylinder of 2-cm diameter and 6-cm length. The target is intended for a study of 3N interactions at the polarized neutron beam generated by the Van de Graaff accelerator at the Charles University in Prague.

  7. Sitzungsberichte der Heidelberger Akademie der Wissenschaften¬Jahrgang 1990 Sitzungsber.Heidelberg 90¬"Gott hat die Natur einfältig gemacht, sie aber suchen viel Künste"

    NASA Astrophysics Data System (ADS)

    Zehe, Horst

    Der Aufsatz demonstriert anhand ausgiebig kommentierter zeitgenössischer Zeugnisse Goethes Reaktion auf die Arbeiten Fraunhofers, insbesondere auf die Entdeckung der dunklen Linien im Sonnenspektrum. Den Fehlurteilen Goethes werden dabei die Urteile zeitgenössischer Physiker wie Chladni und J.F.W. Herschel gegenübergestellt. Bislang noch ungedruckte Dokumente aus dem Weimarer Goethe- und Schiller-Archiv belegen, daß sich Goethe nicht nur literarisch mit Fraunhofer beschäftigte, sondern daß er auch dessen Versuche mit Hilfe des Jenaer Universitätsmechanikers Körner getreulich zu wiederholen suchte.

  8. Impromptu Speech: A Symposium. Papers Contributed to a Symposium on Problems in the Linguistic Study of Impromptu Speech (Abo, Finland, November 20-22, 1981). Meddelanden fran Stiftelsens for Abo Akademi Forskningsinstitut Nr.78.

    ERIC Educational Resources Information Center

    Enkvist, Nils Erik, Ed.

    The titles of papers in this document on impromptu or spontaneous speech are as follows: "Impromptu Speech, Structure, and Process"; "Non-Verbal Aspects of Impromptu Speech"; "Echanges, interventions et actes de langage dans la structure de la conversation" ("Exchanges, Interventions, and Speech Acts in the…

  9. Final report from VFL Technologies for the pilot-scale thermal treatment of Lower East Fork Poplar Creek floodplain soils. LEFPC appendices. Volume 5. Appendix V-D

    SciTech Connect

    1994-09-01

    This final report from VFL Technologies for the pilot-scale thermal treatment of lower East Fork Poplar Creek floodplain soils dated September 1994 contains LEFPC Appendices, Volume 5, Appendix V - D. This appendix includes the final verification run data package (PAH, TCLP herbicides, TCLP pesticides).

  10. Bedside determination of bicarbonate and base excess, blood oxygen saturation and content, VD/VT, and P50 using a programmable calculator.

    PubMed

    Wilkinson, P L

    1979-06-01

    Assessing and modifying oxygen transport are major parts of ICU patient management. Determination of base excess, blood oxygen saturation and content, dead space ventilation, and P50 helps in this management. A program is described for determining these variables using a T1 59 programmable calculator and PC 100A printer. Each variable can be independently calculated without running the whole program. The calculator-printer's small size, low cost, and hard copy printout make it a valuable and versatile tool for calculating physiological variables. The program is easily entered by an stored on magnetic card, and prompts the user to enter the appropriate variables, making is easy to run by untrained personnel.

  11. On the cutoff parameter in the translation-invariant theory of the strong coupling polaron (response to comments [8] on the paper V.D. Lakhno, SSC 152 (2012) 621)

    NASA Astrophysics Data System (ADS)

    Lakhno, V. D.

    2012-10-01

    The paper is a reply to the arguments adduced by the authors of [8] against the results obtained by the author in [6,7]. It is shown that these arguments are based on the erroneous approach made in [8] to the strong coupling limit when the cutoff parameter is introduced in the theory.

  12. Cooperative Threat Reduction for a New Era

    DTIC Science & Technology

    2004-09-01

    James E. Goodby, Daniel L. Burghart, Cheryl A. Loeb and Charles L. Thornton Center for Technology and... Daniel L. Burghart joined the Center for Technology and National Security Policy in July 2003 after his retirement from the United States Army as a...sample was seized by police in Ceske Budejovice. May 29, 1999 Rousse , Bulgaria HEU: 10 grams Customs officials arrested a man trying to smuggle HEU at

  13. Micronuclei levels in mothers and their newborns from regions with different types of air pollution.

    PubMed

    Rossnerova, Andrea; Spatova, Milada; Pastorkova, Anna; Tabashidze, Nana; Veleminsky, Milos; Balascak, Ivan; Solansky, Ivo; Sram, Radim J

    2011-10-01

    The aim of this study was to analyze genetic damage in human lymphocytes measured using automated image analysis of micronuclei (MN) in a group of 178 mothers and their newborns from two locations in the Czech Republic. The concentrations of benzo[a]pyrene (B[a]P), particulate matter of aerodynamic diameter <2.5 μm (PM2.5) and benzene were measured by stationary monitoring in the winter season of 2008/2009 in the capital city of Prague and in Ceske Budejovice, a regional city in a rural area. The 3-month mean concentration of B[a]P before delivery was lower in Prague in comparison with Ceske Budejovice: 1.9 ± 0.5ng/m³ vs. 3.2 ± 0.2ng/m³ (p<0.001). The opposite trend was found for PM2.5 and benzene: 27.0 ± 2.5μg/m³ and 2.5 ± 0.5μg/m³ vs. 24.5 ± 0.7μg/m³ and 2.1 ± 0.8μg/m³ (p<0.001) for Prague vs. Ceske Budejovice, respectively. The average age of the mothers was 31 years (range, 18-49 years). The frequencies of MN per 1000 binucleated cells were 8.35 ± 3.06 vs. 6.47 ± 2.35 (p<0.001) for mothers from Prague and Ceske Budejovice, respectively, and 2.17 ± 1.32 vs. 3.82 ± 2.43 (p<0.001) for newborns from Prague and Ceske Budejovice, respectively. Other factors, including vitamin intake, exposure to tobacco smoke, body mass index (BMI) before pregnancy, the education level of the mothers and the impact of the mothers' and fathers' ages were analyzed in our study. The results suggest that the different sensitivity of the study groups to various mixtures of carcinogenic pollutants could be affected by significant differences in lifestyle factors. Possible higher genetic damage was analyzed in newborns of smoking mothers, and the birth weight of this group was 7.4% lower (p<0.05) in comparison with the newborns of nonsmoking mothers. No impact of the age of the mothers or fathers on MN frequency in the newborns was observed.

  14. Health impact of air pollution to children.

    PubMed

    Sram, Radim J; Binkova, Blanka; Dostal, Miroslav; Merkerova-Dostalova, Michaela; Libalova, Helena; Milcova, Alena; Rossner, Pavel; Rossnerova, Andrea; Schmuczerova, Jana; Svecova, Vlasta; Topinka, Jan; Votavova, Hana

    2013-08-01

    Health impact of air pollution to children was studied over the last twenty years in heavily polluted parts of the Czech Republic during. The research program (Teplice Program) analyzed these effects in the polluted district Teplice (North Bohemia) and control district Prachatice (Southern Bohemia). Study of pregnancy outcomes for newborns delivered between 1994 and 1998 demonstrated that increase in intrauterine growth retardation (IUGR) was associated with PM10 and c-PAHs exposure (carcinogenic polycyclic aromatic hydrocarbons) in the first month of gestation. Morbidity was followed in the cohort of newborns (N=1492) up to the age of 10years. Coal combustion in homes was associated with increased incidence of lower respiratory track illness and impaired early childhood skeletal growth up to the age of 3years. In preschool children, we observed the effect of increased concentrations of PM2.5 and PAHs on development of bronchitis. The Northern Moravia Region (Silesia) is characterized by high concentrations of c-PAHs due to industrial air pollution. Exposure to B[a]P (benzo[a]pyrene) in Ostrava-Radvanice is the highest in the EU. Children from this part of the city of Ostrava suffered higher incidence of acute respiratory diseases in the first year of life. Gene expression profiles in leukocytes of asthmatic children compared to children without asthma were evaluated in groups from Ostrava-Radvanice and Prachatice. The results suggest the distinct molecular phenotype of asthma bronchiale in children living in polluted Ostrava region compared to children living in Prachatice. The effect of exposure to air pollution to biomarkers in newborns was analyzed in Prague vs. Ceske Budejovice, two locations with different levels of pollution in winter season. B[a]P concentrations were higher in Ceske Budejovice. DNA adducts and micronuclei were also elevated in cord blood in Ceske Budejovice in comparison to Prague. Study of gene expression profiles in the cord blood showed

  15. Reports on Text Linguistics: Approaches to Word Order.

    ERIC Educational Resources Information Center

    Enkvist, Nils Erik; Kohonen, Viljo

    This volume contains papers presented in connection with a symposium held in 1975 and sponsored by Abo Akademi, for the purpose of discussing ongoing research in word-order studies. Papers include: (1) a prolegomena by N.E. Enkvist; (2) "On the Ordering of Sister Constituents in Swedish," by E. Andersson; (3) "What is New…

  16. [Complementarity of causality and finality in biology--a report reviewing two lectures given at the 1987 annual meeting of the Leopoldina].

    PubMed

    Peil, J

    1988-01-01

    Reviews of the opening lecture of H. Mohr "The Elementary in the Science--Possibilities and Limits of the Reductionism" and of the final lecture of N. Bischof "Order and Organization as Heuristic Principles of the Reductive Way of Thinking" at the meeting 1987 of the Deutsche Akademie der Naturforscher LEOPOLDINA are framed by remarks about the connections between Biology and Physics.

  17. On the Resonance Concept in Systems of Linear and Nonlinear Ordinary Differential Equations

    DTIC Science & Technology

    1965-11-01

    Determinanten und Matrizen mit Anwen- dungen in Physik und Technik). Berlin: Akademie-Verlag 1949. The author wishes to express his thanks to Prof.Dr.R.Iglisch...Case in the System of Ordinary Linear Differential Equations, Part III ( Studium des Resonanzfalles bei Systemen linearer gew6hnlicher

  18. On the Extreme Order Statistics for a Stationary Sequence.

    DTIC Science & Technology

    1987-07-01

    DTIC TAB U!, anounced 0 "+’. ~juztfjatin------ Technical Report No. 198 By. ~~Distribtion/_____. * July 1987 Aviltbility Cods 7 Avai A-/ o - St...Random Measures. Berlin: Akademie-Verlag, London- New York: Academic Press . Le-dbetter, M. R. (1974). On extreme values in stationary sequences. Z

  19. Physik-Nobelpreis 2004 Von der Freiheit in der Welt der Quarks

    NASA Astrophysics Data System (ADS)

    Bartels, Jochen

    2004-11-01

    Die Schwedische Akademie der Wissenschaften vergab in diesem Jahr den Physik-Nobelpreis zu gleichen Teilen an die amerikanischen Physiker David Gross, David Politzer und Frank Wilczek. Sie würdigte damit ihre theoretischen Arbeiten zur asymptotischen Freiheit in der starken Wechselwirkung.

  20. Exploitation of the Sol-Gel Route in Processing of Ceramics and Composites.

    DTIC Science & Technology

    1987-07-10

    is the only substance which Matijevic [22]. was ever observed to grow from seed." In each case, boehmite (particle size, about Since 1982 when we...Zsigmondy and P. A. Thiessen, Das Kolloide 22 E. Matijevic . Monodispersed colloidal metal Gold, Akademie, Leipzig. 1925, p. 229. oxides, sulfides, and

  1. The Quasigeoid and the Standard Elevations -- East Germany --

    DTIC Science & Technology

    2007-11-02

    3. Listing, E. B., »About our Present Knowledge of the Shape and Siae of the Earth," Nachrichten der Koenig- .lichen Gesellschaft /Reports of the...sT, "The Outer Gravitational Field and the Shape of the Physical Earth’s Surface," (in Russian), Nachrichten der Akademie der Wissenschaftea der

  2. Vitamin D metabolism, sex hormones, and male reproductive function.

    PubMed

    Blomberg Jensen, Martin

    2012-08-01

    The spectrum of vitamin D (VD)-mediated effects has expanded in recent years, and VD is now recognized as a versatile signaling molecule rather than being solely a regulator of bone health and calcium homeostasis. One of the recently identified target areas of VD is male reproductive function. The VD receptor (VDR) and the VD metabolizing enzyme expression studies documented the presence of this system in the testes, mature spermatozoa, and ejaculatory tract, suggesting that both systemic and local VD metabolism may influence male reproductive function. However, it is still debated which cell is the main VD target in the testis and to what extent VD is important for sex hormone production and function of spermatozoa. This review summarizes descriptive studies on testicular VD metabolism and spatial distribution of VDR and the VD metabolizing enzymes in the mammalian testes and discusses mechanistic and association studies conducted in animals and humans. The reviewed evidence suggests some effects of VD on estrogen and testosterone biosynthesis and implicates involvement of both systemic and local VD metabolism in the regulation of male fertility potential.

  3. Vitamin D deficiency exacerbates atypical antipsychotic-induced metabolic side effects in rats: involvement of the INSIG/SREBP pathway.

    PubMed

    Dang, Ruili; Jiang, Pei; Cai, Hualin; Li, Huande; Guo, Ren; Wu, Yanqin; Zhang, Lihong; Zhu, Wenye; He, Xin; Liu, Yiping; Xu, Ping

    2015-08-01

    Metabolic syndrome is a major concern in psychotic patients receiving atypical antipsychotics. Recent evidence suggests that sterol regulatory element-binding proteins (SREBPs) and insulin-induced genes (INSIGs) are implicated in the antipsychotic-induced metabolic side-effects. Vitamin D (VD) deficiency, a highly prevalent phenomenon among patients with psychosis, might also predispose individuals to metabolic syndrome Considering that VD has modulating effects on the INSIG/SREBP pathway, it is possible that VD may have a role in the antipsychotic-induced metabolic disturbances involving its effects on the INSIG/SREBP system. Thus, the present study aimed to evaluate the effects of VD deficiency and VD supplementation on antipsychotic-induced metabolic changes in rats. After 4-week administration, clozapine (10mg/kg/d) and risperidone (1mg/kg/d) both caused glucose intolerance and insulin resistance in VD deficient rats, but not in rats with sufficient VD status. Antipsychotic treatments, especially clozapine, elevated serum lipid levels, which were most apparent in VD deficient rats, but alleviated in VD-supplemented rats. Additionally, antipsychotic treatments down-regulated INSIGs and up-regulated SREBPs expression in VD deficient rats, and these effects were attenuated when VD status was more sufficient. Collectively, this study disclose the novel findings that antipsychotic-induced metabolic disturbances is exacerbated by VD deficiency and can be alleviated by VD supplementation, providing new evidence for the promising role of VD in prevention and treatment of metabolic disorders caused by antipsychotic medications. Furthermore, our data also suggest the involvement of INSIG/SREBP pathway in the antipsychotic-induced hyperlipidemia and beneficial effects of VD on lipid profile.

  4. Vitamin D(3) enhances ATRA-mediated neurosteroid biosynthesis in human glioma GI-1 cells.

    PubMed

    Yagishita, Toshiaki; Kushida, Akira; Tamura, Hiroomi

    2012-09-01

    Emerging evidence indicates that vitamin D (VD) is an important modulator of brain development and function. To investigate whether VD modulates neurosteroid biosynthesis in neural cells, we investigated the effect of VD(3) on steroidogenic gene expression in human glioma GI-1 cells. We found that VD(3) enhanced CYP11A1 and 3β-hydroxysteroid dehydrogenase gene expression. The induction of CYP11A1 gene expression by VD(3) was dose- and incubation time-dependent. Calcipotriol, a VD(3) receptor (VDR) agonist, also induced CYP11A1 gene expression in GI-1 cells, indicating that VDR is involved in this induction. The induction of progesterone (PROG) de novo synthesis was observed along with the induction of steroidogenic genes by VD(3). Furthermore, VD(3) enhanced all-trans retinoic acid (ATRA)-induced CYP11A1 gene expression and PROG production. This suggests cooperative regulation of steroidogenic gene expression by the two fat-soluble vitamins, A and D. In addition, a mixed culture of neuronal IMR-32 cells and GI-1 cells treated with ATRA and VD(3) resulted in the induction of PROG-responsive gene expression in the IMR-32 cells. This result shows a paracrine action of PROG that is induced in and released by the GI-1 cells. The relationship between neurological dysfunction associated with VD deficiency and neurosteroid induction by VD is discussed.

  5. Adsorption of large hydrocarbons on coinage metals: a van der Waals density functional study.

    PubMed

    Björk, Jonas; Stafström, Sven

    2014-09-15

    The adsorption of organic molecules onto the close-packed facets of coinage metals is studied, and how accurately adsorption heights can be described by using recent advances of the van der Waals density functional (vdWDF), with optPBE/vdWDF, optB86b/vdWDF, vdWDF2, and rev/vdWDF2 functionals is illustrated. The adsorption of two prototypical aromatic hydrocarbons is investigated, and the calculated adsorption heights are compared to experimental literature values from normal incident X-ray standing wave absorption and a state-of-the-art semi-empirical method. It is shown that both the optB86b/vdWDF and rev/vdWDF2 functionals describe adsorption heights with an accuracy of 0.1 Å, compared to experimental values, and are concluded as reliable methods of choice for related systems.

  6. Potential determinants of deductible uptake in health insurance: How to increase uptake in The Netherlands?

    PubMed

    van Winssen, K P M; van Kleef, R C; van de Ven, W P M M

    2016-12-01

    In health insurance, voluntary deductibles are offered to the insured in return for a premium rebate. Previous research has shown that 11 % of the Dutch insured opted for a voluntary deductible (VD) in health insurance in 2014, while the highest VD level was financially profitable for almost 50 % of the population in retrospect. To explain this discrepancy, this paper identifies and discusses six potential determinants of the decision to opt for a VD from the behavioral economic literature: loss aversion, risk attitude, ambiguity aversion, debt aversion, omission bias, and liquidity constraints. Based on these determinants, five potential strategies are proposed to increase the number of insured opting for a VD. Presenting the VD as the default option and providing transparent information regarding the VD are the two most promising strategies. If, as a result of these strategies, more insured would opt for a VD, moral hazard would be reduced.

  7. Verticillium dahliae manipulates plant immunity by glycoside hydrolase 12 proteins in conjuction with carbohydrate-binding module 1.

    PubMed

    Gui, Yue-Jing; Chen, Jie-Yin; Zhang, Dan-Dan; Li, Nan-Yang; Li, Ting-Gang; Zhang, Wen-Qi; Wang, Xin-Yan; Short, Dylan P G; Li, Lei; Guo, Wei; Kong, Zhi-Qiang; Bao, Yu-Ming; Subbarao, Krishna V; Dai, Xiao-Feng

    2017-02-15

    Glycoside hydrolase 12 (GH12) proteins act as virulence factors and pathogen-associated molecular patterns (PAMPs) in oomycetes. However, the pathogenic mechanisms of fungal GH12 proteins have not been characterized. In this study, we demonstrated that two of the six GH12 proteins produced by the fungus Verticillium dahliae Vd991, VdEG1 and VdEG3 acted as PAMPs to trigger cell death and PAMP-triggered immunity (PTI) independent of their enzymatic activity in Nicotiana benthamiana. A 63-amino-acid peptide of VdEG3 was sufficient for cell death-inducing activity, but this was not the case for the corresponding peptide of VdEG1. Further study indicated that VdEG1 and VdEG3 trigger PTI in different ways: BAK1 is required for VdEG1- and VdEG3-triggered immunity, while SOBIR1 is specifically required for VdEG1-triggered immunity in N. benthamiana. Unlike oomycetes, which employ RXLR effectors to suppress host immunity, a carbohydrate-binding module family 1 (CBM1) protein domain suppressed GH12 protein-induced cell death. Furthermore, during infection of N. benthamiana and cotton, VdEG1 and VdEG3 acted as PAMPs and virulence factors, respectively indicative of host-dependent molecular functions. These results suggest that VdEG1 and VdEG3 associate differently with BAK1 and SOBIR1 receptor-like kinases to trigger immunity in N. benthamiana, and together with CBM1-containing proteins manipulate plant immunity. This article is protected by copyright. All rights reserved.

  8. A Drosophila haemocyte-specific protein, hemolectin, similar to human von Willebrand factor.

    PubMed Central

    Goto, A; Kumagai, T; Kumagai, C; Hirose, J; Narita, H; Mori, H; Kadowaki, T; Beck, K; Kitagawa, Y

    2001-01-01

    We identified a novel Drosophila protein of approximately 400 kDa, hemolectin (d-Hml), secreted from haemocyte-derived Kc167 cells. Its 11.7 kbp cDNA contains an open reading frame of 3843 amino acid residues, with conserved domains in von Willebrand factor (VWF), coagulation factor V/VIII and complement factors. The d-hml gene is located on the third chromosome (position 70C1-5) and consists of 26 exons. The major part of d-Hml consists of well-known motifs with the organization: CP1-EG1-CP2-EG2-CP3-VD1-VD2-VD'-VD3-VC1-VD"-VD"'-FC1-FC2-VC2-LA1-VD4-VD5-VC3-VB1-VB2-VC4-VC5-CK1 (CP, complement-control protein domain; EG, epidermal-growth-factor-like domain; VB, VC, VD, VWF type B-, C- and D-like domains; VD', VD", VD"', truncated C-terminal VDs; FC, coagulation factor V/VIII type C domain; LA, low-density-lipoprotein-receptor class A domain; CK, cysteine knot domain). The organization of VD1-VD2-VD'-VD3, essential for VWF to be processed by furin, to bind to coagulation factor VIII and to form interchain disulphide linkages, is conserved. The 400 kDa form of d-Hml was sensitive to acidic cleavage near the boundary between VD2 and VD', where the cleavage site of pro-VWF is located. Agarose-gel electrophoresis of metabolically radiolabelled d-Hml suggested that it is secreted from Kc167 cells mainly as dimers. Resembling VWF, 7.9% (305 residues) of cysteine residues on the d-Hml sequence had well-conserved positions in each motif. Coinciding with the development of phagocytic haemocytes, d-hml transcript was detected in late embryos and larvae. Its low-level expression in adult flies was induced by injury at any position on the body. PMID:11563973

  9. Metabolic responses to dietary cholecalciferol and phosphorus in abalone Haliotis discus hannai ino.

    PubMed

    Zhang, Wenbing; Mai, Kangsen; Xu, Wei; Ma, Hongming

    2003-10-01

    Metabolic responses of cholecalciferol (VD(3)) and minerals (Ca, P and Mg) in abalone Haliotis discus hannai Ino to dietary VD(3) and phosphorus (P) were investigated. Based on a 2 x 2 factorial design, four casein-gelatin-based diets were formulated. The basal diet was supplemented with either 0 or 2000 IU VD(3)/kg diet and 0 or 10 g P/kg diet. The abalone was reared in P-free artificial seawater for 55 days. Results showed that dietary VD(3) was hydroxylated to 25-hydroxyvitamin D(3) [25(OH)D(3)] and 1 alpha,25-dihydroxyvitamin D(3) [1 alpha,25(OH)(2)D(3)] in abalone, and subsequently raised the serum levels of these two VD(3) metabolites. Dietary P deficiency elevated serum 1 alpha,25(OH)(2)D(3) level only when the dietary VD(3) supplementation was sufficient. The supplementations of either dietary VD(3) or P significantly increased the levels of P in serum, mantle and hepatopancreas, and only the addition of VD(3) significantly raised the concentrations of Ca in serum and mantle (P<0.05). Interaction between dietary VD(3) and P was only found significant on the concentrations of P and Mg in mantle (P<0.05). The concentrations of Ca, P and Mg in muscle were not significantly influenced by these dietary treatments. Hence, the metabolic responses in serum, muscle, mantle and hepatopancreas of abalone to dietary VD(3) and P were in different manners.

  10. Electron response in van der Waals density functionals

    NASA Astrophysics Data System (ADS)

    Hyldgaard, Per

    2013-03-01

    There is significant interest in density functional theory (DFT) of dispersive or van der Waals (vdW) interactions and in DFT studies of sparse systems where vdW forces contribute to the cohesion and behavior. The Rutgers-Chalmers van der Waals density functional (vdW-DF) method [PRL 92, 246401 (2004); PRB 76, 125112 (2007)] is a nonempirical approach to calculate vdW bonding and for DFT characterizations of sparse matter. The vdW-DF framework is defined by a single exchange-correlation density functional that rests on a plasmon-type description for both semilocal components and for a parameter-free evaluation of nonlocal correlation. My talk summarizes a set of vdW-DF studies that seeks to map and analyze details in the vdW-DF electron-response nature. The purpose is in part to extract consequences that can facilitate an experiment-theory comparison that goes beyond binding geometries and energies. The aim is also to seek implications that can help develop the vdW-DF framework. I present an analysis of the relative importance of morphology, screening (image-plane formation), and collective effects in the vdW-DF description of molecular systems. In addition, I compare vdW-DF results with Cu(111) experiments that tests the electron-response behavior in terms of adsorption-induced band shifts, the form of the overall light-molecule physisorption potential, and the corrugation in the kinetic-energy repulsion of molecules at surfaces. Overall, the vdW-DF studies suggest the importance of benchmarking vdW methods across different length scales and by exploring the variation that arise when related structures have a different balance between exchange repulsion and vdW attraction.

  11. Modeling the adsorption of short alkanes in the zeolite SSZ-13 using "van der Waals" DFT exchange correlation functionals: Understanding the advantages and limitations of such functionals

    NASA Astrophysics Data System (ADS)

    Göltl, Florian; Sautet, Philippe

    2014-04-01

    The inclusion of non-local interactions is one of the large challenges in density functional theory. Very promising methods are the vdW-DF2 and BEEF-vdW functionals, which combine a semi-local approximation for exchange interactions and a non-local correlation expression. In this work we apply those functionals to model the adsorption of short alkanes in the zeolite SSZ-13. Even though results for energetics are improved with respect to other vdW-DF based methods, we still find a comparatively large error compared to high-level calculations. These errors result from approximations in the determination of the dielectric function and of the van der Waals kernel. The insights presented in this work will help to understand the performance not only of vdW-DF2 and BEEF-vdW, but all vdW-DF based functionals in various chemically or physically important systems.

  12. Heterostructures based on inorganic and organic van der Waals systems

    NASA Astrophysics Data System (ADS)

    Lee, Gwan-Hyoung; Lee, Chul-Ho; van der Zande, Arend M.; Han, Minyong; Cui, Xu; Arefe, Ghidewon; Nuckolls, Colin; Heinz, Tony F.; Hone, James; Kim, Philip

    2014-09-01

    The two-dimensional limit of layered materials has recently been realized through the use of van der Waals (vdW) heterostructures composed of weakly interacting layers. In this paper, we describe two different classes of vdW heterostructures: inorganic vdW heterostructures prepared by co-lamination and restacking; and organic-inorganic hetero-epitaxy created by physical vapor deposition of organic molecule crystals on an inorganic vdW substrate. Both types of heterostructures exhibit atomically clean vdW interfaces. Employing such vdW heterostructures, we have demonstrated various novel devices, including graphene/hexagonal boron nitride (hBN) and MoS2 heterostructures for memory devices; graphene/MoS2/WSe2/graphene vertical p-n junctions for photovoltaic devices, and organic crystals on hBN with graphene electrodes for high-performance transistors.

  13. Nanoparticles based on hydrophobic alginate derivative as nutraceutical delivery vehicle: vitamin D3 loading.

    PubMed

    Sun, Fusheng; Ju, Chuanxia; Chen, Jiahong; Liu, Sai; Liu, Na; Wang, Keke; Liu, Chenguang

    2012-02-01

    We report the application of Vitamin D3 (VD(3)) in nanoparticles of oleoyl alginate ester (OAE)(OAE-VD(3)). The internalization of fluorescent OAE-VD(3) by Caco-2 cells was visualized by confocal laser scanning microscopy. In vivo pharmacokinetic studies showed that incorporation into OAE nanoparticles resulted in increased absorption of VD(3). Its application in the treatment of rickets was assayed using a model of nutritionally induced vitamin D-deficiency rickets. The results showed that the encapsulated VD(3) had better efficacy than that of the free drug in vivo. Our studies provide evidence that OAE nanoparticles are valuable as nutraceutical delivery vehicles to enhance the absorption of VD(3).

  14. Electrosorptive Detection of Simple Organic Compounds in Liquid Chromatography.

    DTIC Science & Technology

    1987-09-30

    Jehring , Elektrosorpelonsanalyse mit der Wechselstrompolarographle, Akademie-Verlag, Berlin, 1974. 3. F. G. Banica, A. Sadoveanu and C. Patroescu...13. 30. H. Jehring , op. cit., Ch. 11. 31. T. Raxnstad and M. J. Weaver, Anal. Chim. Acta, in press. 32. T. Ramstad and M. J. Weaver, submitted for...Comprehensive Treatise of Electrochemistry, Plenum, New York, 1980, Vol. 1, Ch. 8. 41. H. Jehring , op. cit., Ch. 10. 24 42. Ibid., Cbs. 6 and 10. 43

  15. Fast Array Algorithms for Structured Matrices

    DTIC Science & Technology

    1989-06-01

    matrices and operators, Akademie-Verlag, Berlin, 1984. [111. T. Kailath , Linear Systems , Prentice-Hall, Englewood Cliffs, New Jersey, 1980. [121. T... Linear Systems Prentice-Hall, Englewood Cliffs, New Jersey, 1980. [131. T. Kailath, Signal processing in the VLSI era, VLSI and Modem Signal Processing...vol 5, No. 1., (1984), pp. 237-254. [11]. F. Gantmacher The theory of matrices, vol. 2, Chelsea Publishing Comp., New York, 1960. [121. T. Kailath

  16. Characterization of cytochrome P450 CYP109E1 from Bacillus megaterium as a novel vitamin D3 hydroxylase.

    PubMed

    Abdulmughni, Ammar; Jóźwik, Ilona K; Putkaradze, Natalia; Brill, Elisa; Zapp, Josef; Thunnissen, Andy-Mark W H; Hannemann, Frank; Bernhardt, Rita

    2017-02-10

    In this study the ability of CYP109E1 from Bacillus megaterium to metabolize vitamin D3 (VD3) was investigated. In an in vitro system using bovine adrenodoxin reductase (AdR) and adrenodoxin (Adx4-108), VD3 was converted by CYP109E1 into several products. Furthermore, a whole-cell system in B. megaterium MS941 was established. The new system showed a conversion of 95% after 24h. By NMR analysis it was found that CYP109E1 catalyzes hydroxylation of VD3 at carbons C-24 and C-25, resulting in the formation of 24(S)-hydroxyvitamin D3 (24S(OH)VD3), 25-hydroxyvitamin D3 (25(OH)VD3) and 24S,25-dihydroxyvitamin D3 (24S,25(OH)2VD3). Through time dependent whole-cell conversion of VD3, we identified that the formation of 24S,25(OH)2VD3 by CYP109E1 is derived from VD3 via the intermediate 24S(OH)VD3. Moreover, using docking analysis and site-directed mutagenesis, we identified important active site residues capable of determining substrate specificity and regio-selectivity. HPLC analysis of the whole-cell conversion with the I85A-mutant revealed an increased selectivity towards 25-hydroxylation of VD3 compared with the wild type activity, resulting in an approximately 2-fold increase of 25(OH)VD3 production (45mgl(-1)day(-1)) compared to wild type (24.5mgl(-1)day(-1)).

  17. Purification, characterization, and directed evolution study of a vitamin D{sub 3} hydroxylase from Pseudonocardia autotrophica

    SciTech Connect

    Fujii, Yoshikazu; Kabumoto, Hiroki; Nishimura, Kenji; Fujii, Tadashi; Yanai, Satoshi; Takeda, Koji; Tamura, Noriko; Arisawa, Akira; Tamura, Tomohiro

    2009-07-24

    Vitamin D{sub 3} (VD{sub 3}) is a fat-soluble prohormone that plays a crucial role in bone metabolism, immunity, and control of cell proliferation and cell differentiation in mammals. The actinomycete Pseudonocardia autotrophica is capable of bioconversion of VD{sub 3} into its physiologically active forms, namely, 25(OH)VD{sub 3} or 1{alpha},25(OH){sub 2}VD{sub 3}. In this study, we isolated and characterized Vdh (vitamin D{sub 3} hydroxylase), which hydroxylates VD{sub 3} from P. autotrophica NBRC 12743. The vdh gene encodes a protein containing 403 amino acids with a molecular weight of 44,368 Da. This hydroxylase was found to be homologous with the P450 belonging to CYP107 family. Vdh had the same ratio of the V{sub max} values for VD{sub 3} 25-hydroxylation and 25(OH)VD{sub 3} 1{alpha}-hydroxylation, while other enzymes showed preferential regio-specific hydroxylation on VD{sub 3}. We characterized a collection of Vdh mutants obtained by random mutagenesis and obtained a Vdh-K1 mutant by the combination of four amino acid substitutions. Vdh-K1 showed one-order higher VD{sub 3} 25-hydroxylase activity than the wild-type enzyme. Biotransformation of VD{sub 3} into 25(OH)VD{sub 3} was successfully accomplished with a Vdh-expressed recombinant strain of actinobacterium Rhodococcus erythropolis. Vdh may be a useful enzyme for the production of physiologically active forms of VD{sub 3} by a single cytochrome P450.

  18. Controlled Synthesis of Organic/Inorganic van der Waals Solid for Tunable Light-Matter Interactions.

    PubMed

    Niu, Lin; Liu, Xinfeng; Cong, Chunxiao; Wu, Chunyang; Wu, Di; Chang, Tay Rong; Wang, Hong; Zeng, Qingsheng; Zhou, Jiadong; Wang, Xingli; Fu, Wei; Yu, Peng; Fu, Qundong; Najmaei, Sina; Zhang, Zhuhua; Yakobson, Boris I; Tay, Beng Kang; Zhou, Wu; Jeng, Horng Tay; Lin, Hsin; Sum, Tze Chien; Jin, Chuanhong; He, Haiyong; Yu, Ting; Liu, Zheng

    2015-12-16

    High-quality organic and inorganic van der Waals (vdW) solids are realized using methylammonium lead halide (CH3 NH3 PbI3 ) as the organic part (organic perovskite) and 2D inorganic monolayers as counterparts. By stacking on various 2D monolayers, the vdW solids exhibit dramatically different light emissions. Futhermore, organic/h-BN vdW solid arrays are patterned for red-light emission.

  19. Neuroanatomic and behavioral correlates of urinary dysfunction induced by vaginal distension in rats.

    PubMed

    Palacios, J L; Juárez, M; Morán, C; Xelhuantzi, N; Damaser, M S; Cruz, Y

    2016-05-01

    The aim of the present study was to use a model of simulated human childbirth in rats to determine the damage to genitourinary structures and behavioral signs of urinary dysfunction induced by vaginal distension (VD) in female rats. In experiment 1, the length of the genitourinary tract and the nerves associated with it were measured immediately after simulated human delivery induced by VD or sham (SH) procedures. Electroneurograms of the dorsal nerve of the clitoris (DNC) were also recorded. In experiment 2, histological characteristics of the bladder and major pelvic ganglion of VD and SH rats were evaluated. In experiment 3, urinary parameters were determined in conscious animals during 6 h of dark and 6 h of light before and 3 days after VD or SH procedures. VD significantly increased distal vagina width (P < 0.001) and the length of the motor branch of the sacral plexus (P < 0.05), DNC (P < 0.05), and vesical nerves (P < 0.01) and decreased DNC frequency and amplitude of firing. VD occluded the pelvic urethra, inducing urinary retention, hematomas in the bladder, and thinness of the epithelial (P < 0.05) and detrusor (P < 0.01) layers of the bladder. Major pelvic ganglion parameters were not modified after VD. Rats dripped urine in unusual places to void, without the stereotyped behavior of micturition after VD. The neuroanatomic injuries after VD occur alongside behavioral signs of urinary incontinence as determined by a new behavioral tool for assessing micturition in conscious animals.

  20. Construction of van der Waals magnetic tunnel junction using ferromagnetic layered dichalcogenide

    NASA Astrophysics Data System (ADS)

    Arai, Miho; Moriya, Rai; Yabuki, Naoto; Masubuchi, Satoru; Ueno, Keiji; Machida, Tomoki

    2015-09-01

    We investigate the micromechanical exfoliation and van der Waals (vdW) assembly of ferromagnetic layered dichalcogenide Fe0.25TaS2. The vdW interlayer coupling at the Fe-intercalated plane of Fe0.25TaS2 allows exfoliation of flakes. A vdW junction between the cleaved crystal surfaces is constructed by dry transfer method. We observe tunnel magnetoresistance in the resulting junction under an external magnetic field applied perpendicular to the plane, demonstrating spin-polarized tunneling between the ferromagnetic layered material and the vdW junction.

  1. AAC as a Potential Target Gene to Control Verticillium dahliae

    PubMed Central

    Su, Xiaofeng; Rehman, Latifur; Guo, Huiming; Li, Xiaokang; Zhang, Rui; Cheng, Hongmei

    2017-01-01

    Verticillium dahliae invades the roots of host plants and causes vascular wilt, which seriously diminishes the yield of cotton and other important crops. The protein AAC (ADP, ATP carrier) is responsible for transferring ATP from the mitochondria into the cytoplasm. When V. dahliae protoplasts were transformed with short interfering RNAs (siRNAs) targeting the VdAAC gene, fungal growth and sporulation were significantly inhibited. To further confirm a role for VdAAC in fungal development, we generated knockout mutants (ΔVdACC). Compared with wild-type V. dahliae (Vd wt), ΔVdAAC was impaired in germination and virulence; these impairments were rescued in the complementary strains (ΔVdAAC-C). Moreover, when an RNAi construct of VdAAC under the control of the 35S promoter was used to transform Nicotiana benthamiana, the expression of VdAAC was downregulated in the transgenic seedlings, and they had elevated resistance against V. dahliae. The results of this study suggest that VdAAC contributes to fungal development, virulence and is a promising candidate gene to control V. dahliae. In addition, RNAi is a highly efficient way to silence fungal genes and provides a novel strategy to improve disease resistance in plants. PMID:28075391

  2. Construction of van der Waals magnetic tunnel junction using ferromagnetic layered dichalcogenide

    SciTech Connect

    Arai, Miho; Moriya, Rai Yabuki, Naoto; Masubuchi, Satoru; Ueno, Keiji; Machida, Tomoki

    2015-09-07

    We investigate the micromechanical exfoliation and van der Waals (vdW) assembly of ferromagnetic layered dichalcogenide Fe{sub 0.25}TaS{sub 2}. The vdW interlayer coupling at the Fe-intercalated plane of Fe{sub 0.25}TaS{sub 2} allows exfoliation of flakes. A vdW junction between the cleaved crystal surfaces is constructed by dry transfer method. We observe tunnel magnetoresistance in the resulting junction under an external magnetic field applied perpendicular to the plane, demonstrating spin-polarized tunneling between the ferromagnetic layered material and the vdW junction.

  3. Prevalence and risk factors for low vitamin D status among breastfeeding mother–infant dyads in an environment with abundant sunshine

    PubMed Central

    Salameh, Khalil; Al-Janahi, Najah Saleh Ali; Reedy, Adriana M; Dawodu, Adekunle

    2016-01-01

    Purpose Evaluation of vitamin D (vD) status and risk factors for low vD among breastfeeding mother–infant dyads in a population at high risk for vD deficiency. Subjects and methods We measured serum 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone at 1 month postpartum in 60 consecutive exclusively breastfeeding Arab mother–infant dyads enrolled in a high dose vD supplementation study to prevent vD deficiency in Doha, Qatar, (latitude 25°N) during summer months. Data were collected on demography, sun exposure, and vD supplementation. Comparison with a US cohort was evaluated. vD deficiency was defined as serum 25(OH)D <50 nmol/L and severe deficiency categorized as 25(OH)D <25 nmol/L in mothers and infants. Results Mean maternal age was 29 years and 77% had college or university education. Maternal median 25(OH)D was 32.5 nmol/L and 78% were vD-deficient and 20% had 25(OH)D <25 nmol/L. Only 42% of mothers had reportedly taken vD supplements postpartum and median dietary vD intake (119 IU/day) and calcium (490 mg/day) were low. Maternal median sun index score (sun exposure [hours/week] × body surface area exposed while outdoors) was 0. Maternal 25(OH)D correlated with percent body surface area exposure while outdoors (rs=0.37, P=0.004). Infant median 25(OH)D was 20 nmol/L and 83% were deficient, while 58% had 25(OH)D <25 nmol/L. Infant 25(OH)D correlated with maternal levels (rs=0.41, P=0.001). None of the infants received vD supplement at 1 month of age and median sun index score was 0. Infant’s parathyroid hormone showed negative correlations with 25(OH)D (rs=−0.28, P=0.03). Sun exposure, vD supplementation rate, and vD status were lower in Doha than Cincinnati, US cohort. Conclusion vD deficiency is common in breastfeeding mother–infant dyads in this sunny environment and is associated with sun avoidance and low vD intake. We suggest corrective vD supplement of breastfeeding mothers and their infants, which should preferably start during

  4. Secretory proteins are delivered to the septin-organized penetration interface during root infection by Verticillium dahliae

    PubMed Central

    Zhou, Ting-Ting; Zhao, Yun-Long

    2017-01-01

    Successful infection of the host requires secretion of effector proteins to evade or suppress plant immunity. Secretion of effectors in root-infecting fungal pathogens, however, remains unexplored. We previously reported that Verticillium dahliae, a root-infecting phytopathogenic fungus, develops a penetration peg from a hyphopodium to infect cotton roots. In this study, we report that a septin ring, requiring VdSep5, partitions the hyphopodium and the invasive hypha and form the specialized fungus-host interface. The mutant strain, VdΔnoxb, in which NADPH oxidase B (VdNoxB) is deleted, impaired formation of the septin ring at the hyphal neck, indicating that NADPH oxidases regulate septin ring organization. Using GFP tagging and live cell imaging, we observed that several signal peptide containing secreted proteins showed ring signal accumulation/secretion at the penetration interface surrounding the hyphal neck. Targeted mutation for VdSep5 reduced the delivery rate of secretory proteins to the penetration interface. Blocking the secretory pathway by disrupting the vesicular trafficking factors, VdSec22 and VdSyn8, or the exocyst subunit, VdExo70, also arrested delivery of the secreted proteins inside the hyphopodium. Reduced virulence was observed when cotton roots were infected with VdΔsep5, VdΔsec22, VdΔsyn8 and VdΔexo70 mutants compared to infection with the isogenic wild-type V592. Taken together, our data demonstrate that the hyphal neck is an important site for protein secretion during plant root infection, and that the multiple secretory routes are involved in the secretion. PMID:28282450

  5. van der Waals density functionals applied to corundum-type sesquioxides: bulk properties and adsorption of CH3 and C6H6 on (0001) surfaces.

    PubMed

    Dabaghmanesh, Samira; Neyts, Erik C; Partoens, Bart

    2016-08-17

    van der Waals (vdW) forces play an important role in the adsorption of molecules on the surface of solids. However, the choice of the most suitable vdW functional for different systems is an essential problem which must be addressed for different systems. The lack of a systematic study on the performance of the vdW functionals in the bulk and adsorption properties of metal-oxides motivated us to examine different vdW approaches and compute the bulk and molecular adsorption properties of α-Cr2O3, α-Fe2O3, and α-Al2O3. For the bulk properties, we compared our results for the heat of formation, cohesive energy, lattice parameters and bond distances between the different vdW functionals and available experimental data. Next we studied the adsorption of benzene and CH3 molecules on top of different oxide surfaces. We employed different approximations to exchange and correlation within DFT, namely, the Perdew-Burke-Ernzerhof (PBE) GGA, (PBE)+U, and vdW density functionals [DFT(vdW-DF/DF2/optPBE/optB86b/optB88)+U] as well as DFT-D2/D3(+U) methods of Grimme for the bulk calculations and optB86b-vdW(+U) and DFT-D2(+U) for the adsorption energy calculations. Our results highlight the importance of vdW interactions not only in the adsorption of molecules, but importantly also for the bulk properties. Although the vdW contribution in the adsorption of CH3 (as a chemisorption interaction) is less important compared to the adsorption of benzene (as a physisorption interaction), this contribution is not negligible. Also adsorption of benzene on ferryl/chromyl terminated surfaces shows an important chemisorption contribution in which the vdW interactions become less significant.

  6. Ethacrynic acid and 1 alpha,25-dihydroxyvitamin D3 cooperatively inhibit proliferation and induce differentiation of human myeloid leukemia cells.

    PubMed

    Makishima, M; Honma, Y

    1996-09-01

    The active form of vitamin D, 1 alpha,25-dihydroxyvitamin D3 (VD3), inhibits proliferation and induces differentiation of leukemia cells, but its clinical use is limited by the adverse effect of hypercalcemia. In this study we found that the loop diuretic ethacrynic acid, which is used to treat hypercalcemia, enhanced the differentiation of human leukemia cells induced by VD3. Ethacrynic acid alone inhibited the proliferation of human promyelocytic HL-60 cells while only slightly increasing differentiation markers such as nitroblue tetrazolium (NBT)-reducing and lysozyme activities. Ethacrynic acid effectively enhanced the growth-inhibiting action of VD3. In the presence of ethacrynic acid, VD3 increased the NBT-reducing and lysozyme activities and the CD11b expression of HL-60 cells more effectively than VD3 alone. Other loop diuretics, furosemide and bumetanide, also enhanced the differentiation of HL-60 cells induced by VD3, but to a lesser extent than ethacrynic acid. The differentiation of HL-60 cells induced by all-trans retinoic acid, dimethyl sulfoxide or phorbol-12-myristate 13-acetate was also enhanced by ethacrynic acid with increasing NBT-reducing and lysozyme activities and the expression of CD11b or CD14 surface antigen. Morphologically, ethacrynic acid enhanced the monocytic differentiation of HL-60 cells induced by VD3 and phorbol ester and the granulocytic differentiation by retinoic acid and dimethyl sulfoxide. Other human myelomonocytic leukemia ML-1, U937, P39/TSU and P31/FUJ cells were induced to differentiate by VD3 and this was also enhanced by ethacrynic acid. The long-term culture of HL-60 cells showed that ethacrynic acid plus VD3 induced the complete growth arrest of HL-60 cells. Therefore ethacrynic acid, which is used to treat hypercalcemia, enhanced the proliferation-inhibiting and differentiation-inducing activities of VD3 and the combination of ethacrynic acid and VD3 may be useful in therapy for myeloid leukemia.

  7. STS (Space Transportation System) Experiment Support Structure Needs Assessment.

    DTIC Science & Technology

    1986-04-01

    LABILITY OF REPORT 2b &CLASSI FICATION/OOWRNGRADING SCHEDULE STATN~ENT "AR* mpf.vd for pubic. r~ euq .." 4 PERFORMING ORGANIZATION REPORT NUMBERISI 5...q ~ .- ~ ~ ~ 400 ~ 4%% %-% N T- -7 Td . T-.. -7 ’-’ i Chapter Five FINDINGS, CONCLUSIONS, 4VD EC41eATIUS In the preceding chapters the factors

  8. The role of the van der Waals interactions in the adsorption of anthracene and pentacene on the Ag(111) surface.

    PubMed

    Morbec, Juliana M; Kratzer, Peter

    2017-01-21

    Using first-principles calculations based on density-functional theory (DFT), we investigated the effects of the van der Waals (vdW) interactions on the structural and electronic properties of anthracene and pentacene adsorbed on the Ag(111) surface. We found that the inclusion of vdW corrections strongly affects the binding of both anthracene/Ag(111) and pentacene/Ag(111), yielding adsorption heights and energies more consistent with the experimental results than standard DFT calculations with generalized gradient approximation (GGA). For anthracene/Ag(111) the effect of the vdW interactions is even more dramatic: we found that "pure" DFT-GGA calculations (without including vdW corrections) result in preference for a tilted configuration, in contrast to the experimental observations of flat-lying adsorption; including vdW corrections, on the other hand, alters the binding geometry of anthracene/Ag(111), favoring the flat configuration. The electronic structure obtained using a self-consistent vdW scheme was found to be nearly indistinguishable from the conventional DFT electronic structure once the correct vdW geometry is employed for these physisorbed systems. Moreover, we show that a vdW correction scheme based on a hybrid functional DFT calculation (HSE) results in an improved description of the highest occupied molecular level of the adsorbed molecules.

  9. The role of the van der Waals interactions in the adsorption of anthracene and pentacene on the Ag(111) surface

    NASA Astrophysics Data System (ADS)

    Morbec, Juliana M.; Kratzer, Peter

    2017-01-01

    Using first-principles calculations based on density-functional theory (DFT), we investigated the effects of the van der Waals (vdW) interactions on the structural and electronic properties of anthracene and pentacene adsorbed on the Ag(111) surface. We found that the inclusion of vdW corrections strongly affects the binding of both anthracene/Ag(111) and pentacene/Ag(111), yielding adsorption heights and energies more consistent with the experimental results than standard DFT calculations with generalized gradient approximation (GGA). For anthracene/Ag(111) the effect of the vdW interactions is even more dramatic: we found that "pure" DFT-GGA calculations (without including vdW corrections) result in preference for a tilted configuration, in contrast to the experimental observations of flat-lying adsorption; including vdW corrections, on the other hand, alters the binding geometry of anthracene/Ag(111), favoring the flat configuration. The electronic structure obtained using a self-consistent vdW scheme was found to be nearly indistinguishable from the conventional DFT electronic structure once the correct vdW geometry is employed for these physisorbed systems. Moreover, we show that a vdW correction scheme based on a hybrid functional DFT calculation (HSE) results in an improved description of the highest occupied molecular level of the adsorbed molecules.

  10. The Development of Memory-Encoding Processes. Final Report.

    ERIC Educational Resources Information Center

    Hall, James W.

    Eight experiments are described in this report. In experiment 1, four and five year olds were presented four verbal discrimination (VD) lists. For three of the lists all correct items were either conceptually, acoustically, or affectively similar. The fourth was a control list. The conceptual list facilitated VD learning. Experiment 2 indicated…

  11. Virtual dimensionality analysis for hyperspectral imagery

    NASA Astrophysics Data System (ADS)

    Chang, Chein-I.; Lee, Li-Chien; Paylor, Drew

    2015-05-01

    Virtual dimensionality (VD) has been widely used to estimate number of endmembers in the past. Unfortunately, the original idea of VD was developed to specify the number of spectrally distinct signatures in hyperspectral data where there is no provided specific definition of what "spectrally distinct signatures" are. As a result, many techniques developed to estimate VD have produced various values for VD. This paper addresses this issue by develops a target specified VD (TSVD) theory where the value of VD is completely determined by targets of interest. In particular, the VD techniques can be categorized according to targets characterized by eigenvalues/eigenvectors and real target signal sources which are used for a binary composite hypothesis testing problem. For the latter case the Automatic Target Generation Process (ATGP) is particularly used to generate real target signal sources to replace eigenvalues/eigenvectors as signal sources to be used for the binary hypothesis testing problem. In order to find probability distributions under each hypothesis the extreme theory used by Maximum Orthogonal Complement Algorithm (MOCA) is used for their derivations. As a result, VD can be estimated by two types of signals sources, eigenvalues/eigenvectors along with two types of detectors, maximum likelihood detector and Neyman-Pearson detector.

  12. [Vitamin D and Polycystic Ovary Syndrome].

    PubMed

    Lazúrová, Ivica; Figurová, Jana; Dravecká, Ingrid

    2016-01-01

    Currently there is growing evidence on possible influence of vitamin D (VD) on reproductive function in both females and males. The relationship between VD and clinical or laboratory manifestations of polycystic ovary syndrome (PCOS) seems to be mostly evaluated. Patients with PCOS have been demonstrated to have significantly lower levels of serum VD and they also have the higher prevalence of vitamin D deficiency as compared to controls. Some studies documented the relation of VD to serum androgen levels, other found that VD correlated with metabolic parameters (body weight, insulin resistance and lipid profile) only. Several interventional studies demonstrated that VD replacement improved these metabolic parameters in PCOS women with VD deficiency. On the other hand some studies also documented improvement of ovarian function and androgen levels. Also vitamin D replacement may represent an additional treatment in VD deficient PCOS women with the aim to improve phenotypic manifestations. It requires further randomized interventional studies on larger groups of patients.Key words: metabolic syndrome - polycystic ovary syndrome - vitamin D.

  13. Verbal Discrimination Learning in a Random Mixture of Two-, Three-, and Four-Word Items with Two Stimulus Presentation Rates.

    ERIC Educational Resources Information Center

    Bugarin, Temotio Espina, Jr.

    The purpose of this experiment was to determine whether a constant information processing rate would occur when subjects in verbal discrimination (VD) learning were presented a mixture of items of different lengths. Forty-two Naval Postgraduate School students served in a VD experiment with a random mixture of two-, three-, and four-word items at…

  14. An Adaptive Reconfigurable Active Voltage Doubler/Rectifier for Extended-Range Inductive Power Transmission

    PubMed Central

    Lee, Hyung-Min; Ghovanloo, Maysam

    2014-01-01

    We present an adaptive reconfigurable active voltage doubler (VD)/rectifier (REC) (VD/REC) in standard CMOS, which can adaptively change its topology to either a VD or a REC by sensing the output voltage, leading to more robust inductive power transmission over an extended range. Both active VD and REC modes provide much lower dropout voltage and far better power conversion efficiency (PCE) compared to their passive counterparts by adopting offset-controlled high-speed comparators that drive the rectifying switches at proper times in the high-frequency band. We have fabricated the active VD/REC in a 0.5-µm 3-metal 2-poly CMOS process, occupying 0.585 mm2 of chip area. In an exemplar setup, VD/REC extended the power transmission range by 33% (from 6 to 8 cm) in relative coil distance and 41.5% (from 53° to 75°) in relative coil orientation compared to using the REC alone. While providing 3.1-V dc output across a 500-Ω load from 2.15- (VD) and 3.7-V (REC) peak ac inputs at 13.56 MHz, VD/REC achieved measured PCEs of 70% and 77%, respectively. PMID:24633369

  15. Impairment of vitamin D metabolism due to environmental cadmium exposure, and possible relevance to sex-related differences in vulnerability to the bone damage

    SciTech Connect

    Tsuritani, Ikiko; Honda, Ryumon; Ishizaki, Masao; Yamada, Yuichi ); Kido, Teruhiko; Nogawa, Koji )

    1992-12-01

    To determine whether depleted serum 1[alpha],25-dihydroxyvitamin D (VD) concentrations are associated with cadmium (Cd)-induced renal damage, the relationships between four indices of renal function and two indicators of bone metabolism, that is, serum VD and parathyroid hormone (PTH) concentrations, were analyzed in 30 male and 44 female subjects exposed to environmental Cd. Also, these associations were compared in male and female subjects to evaluate sex-related differences in vulnerability to the bone damage observed in Cd-exposed persons. Serum VD decreased significantly with declines in creatinine clearance and percentage tubular reabsorption of phosphate, and with increases in serum creatinine and serum [beta][sub 2]-microglobulin ([beta][sub 2]m) concentrations in the female subjects exposed to Cd, but not in the male subjects. The correlation between serum VD and PTH levels was also significant only in the females. Correlation coefficients between serum [beta][sub 2]m and VD and those between serum PTH and VD in both sexes were significantly different. These results suggest that renal damage due to Cd exposure leads to the decreases in the serum VD level and increases in serum PTH level, and that the more marked changes in serum VD and PTH in the women may play a role in the development of sex-related differences in Cd-induced bone injury.

  16. Bone characteristics of 16 wk-old turkeys subjected to different dietary regimens and simulated stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of a yeast extract (YE) feed supplement and/or vitamin D3 (VD) on the bone properties of 16 wk-old turkeys, transiently subjected to a simulated stress using dexamethasone (Dex), were determined. The turkeys were fed diets with or without YE and/or VD during 6, 11, and 15 wk post hatch, ...

  17. Effects of yeast extract and vitamin D on turkey mortality and cellulitis incidence in a transport stress model.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We evaluated yeast extract (YE) and vitamin D (VD) in turkeys treated with dexamethasone (Dex) at intervals designed to simulate transport stress during a 3 stage growout. YE but not VD decreased early mortality (P = 0.001) and mortality at wk 7 (P= 0.02) and wk 12 (P = 0.002) but not wk 16. Celluli...

  18. Retinal Vessel Density in Optical Coherence Tomography Angiography in Optic Atrophy after Nonarteritic Anterior Ischemic Optic Neuropathy

    PubMed Central

    Kao, Ling-Yuh; Sun, Ming-Hui

    2017-01-01

    Aims. To compare optical coherence tomography angiography (OCT-A) retinal vasculature measurements between normal and optic atrophy after nonarteritic anterior ischemic optic neuropathy (NAION) subjects. Design. This prospective observational study was conducted between July 2015 and August 2016 at the ophthalmology outpatient department of a referral center in Taiwan. Peripapillary (4.5 × 4.5 mm) and parafoveal (6 × 6 mm) OCT-A scans were acquired. Measurements of the peripapillary region were obtained in two areas: (1) circumpapillary vessel density (cpVD) and (2) whole enface image vessel density (wiVD). Results. 13 participants with optic atrophy after NAION had lower peripapillary vessel density than the 18 age-matched participants in the healthy control (HC) group (p < 0.001 for both cpVD and wiVD). However, the parafoveal vessel density was not significantly different between the two groups (p = 0.49). The areas under the receiver operating characteristic curve for the HC and NAION eyes were 0.992 for cpVD and 0.970 for wiVD. cpVD and wiVD were significantly correlated with the average retinal nerve fiber layer thickness (p < 0.001 for both). Conclusion. Peripapillary retinal perfusion is significantly decreased in optic atrophy after NAION. OCT-A may aid in the understanding of structure-function-perfusion relationships in NAION. PMID:28316838

  19. 14 CFR 23.629 - Flutter.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... surfaces. (e) For turbopropeller-powered airplanes, the dynamic evaluation must include— (1) Whirl mode... damping as VD is approached. (c) Any rational analysis used to predict freedom from flutter, control... must be shown by analysis to be free from flutter up to VD/MD after fatigue failure, or obvious...

  20. 14 CFR 23.629 - Flutter.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... surfaces. (e) For turbopropeller-powered airplanes, the dynamic evaluation must include— (1) Whirl mode... damping as VD is approached. (c) Any rational analysis used to predict freedom from flutter, control... must be shown by analysis to be free from flutter up to VD/MD after fatigue failure, or obvious...

  1. Pulmonary administration of 1,25-dihydroxyvitamin D3 to the lungs induces alveolar regeneration in a mouse model of chronic obstructive pulmonary disease.

    PubMed

    Horiguchi, Michiko; Hirokawa, Mai; Abe, Kaori; Kumagai, Harumi; Yamashita, Chikamasa

    2016-07-10

    Chronic obstructive pulmonary disease (COPD) is a progressive respiratory disease with several causes, including smoking, and no curative therapeutic agent is available, particularly for destructive alveolar lesions. In this study, we investigated the differentiation-inducing effect on undifferentiated lung cells (Calu-6) and the alveolar regenerative effect of the active vitamin 1,25-dihydroxy vitamin D3 (VD3) with the ultimate goal of developing a novel curative drug for COPD. First, the differentiation-inducing effect of VD3 on Calu-6 cells was evaluated. Treatment with VD3 increased the proportions of type I alveolar epithelial (AT-I) and type II alveolar epithelial (AT-II) cells constituting alveoli in a concentration- and treatment time-dependent manner, demonstrating the potent differentiation-inducing activity of VD3 on Calu-6 cells. We thus administered VD3 topically to the mice lung using a previously developed intrapulmonary administration via self-inhalation method. To evaluate the alveolus-repairing effect of VD3, we administered VD3 intrapulmonarily to elastase-induced COPD model mice and computed the mean distance between the alveolar walls as an index of the extent of alveolar injury. Results showed significant decreases in the alveolar wall distance in groups of mice that received 0.01, 0.1, and 1μg/kg of intrapulmonary VD3, revealing excellent alveolus-regenerating effect of VD3. Furthermore, we evaluated the effect of VD3 on improving respiratory function using a respiratory function analyzer. Lung elasticity and respiratory competence [forced expiratory volume (FEV) 1 s %] are reduced in COPD, reflecting advanced emphysematous changes. In elastase-induced COPD model mice, although lung elasticity and respiratory competence were reduced, VD3 administered intrapulmonarily twice weekly for 2weeks recovered tissue elastance and forced expiratory volume in 0.05s to the forced vital capacity, which are indicators of lung elasticity and respiratory

  2. Interlayer Transition and Infrared Photodetection in Atomically Thin Type-II MoTe₂/MoS₂ van der Waals Heterostructures.

    PubMed

    Zhang, Kenan; Zhang, Tianning; Cheng, Guanghui; Li, Tianxin; Wang, Shuxia; Wei, Wei; Zhou, Xiaohao; Yu, Weiwei; Sun, Yan; Wang, Peng; Zhang, Dong; Zeng, Changgan; Wang, Xingjun; Hu, Weida; Fan, Hong Jin; Shen, Guozhen; Chen, Xin; Duan, Xiangfeng; Chang, Kai; Dai, Ning

    2016-03-22

    We demonstrate the type-II staggered band alignment in MoTe2/MoS2 van der Waals (vdW) heterostructures and an interlayer optical transition at ∼1.55 μm. The photoinduced charge separation between the MoTe2/MoS2 vdW heterostructure is verified by Kelvin probe force microscopy (KPFM) under illumination, density function theory (DFT) simulations and photoluminescence (PL) spectroscopy. Photoelectrical measurements of MoTe2/MoS2 vdW heterostructures show a distinct photocurrent response in the infrared regime (1550 nm). The creation of type-II vdW heterostructures with strong interlayer coupling could improve our fundamental understanding of the essential physics behind vdW heterostructures and help the design of next-generation infrared optoelectronics.

  3. Analysis of the genetic information of a DNA segment of a new virus from silkworm.

    PubMed

    Bando, H; Hayakawa, T; Asano, S; Sahara, K; Nakagaki, M; Iizuka, T

    1995-01-01

    In 1983, a parvo-like virus (Yamanashi isolate) was newly isolated from silkworm. However, unlike parvovirus, two DNA molecules (VD1 and 2) were always extracted from purified virions. To investigate the structure and organization of the virus genomes, we determined the complete nucleotide sequence of VD2. The sequence consisted of 6031 nucleotides (nts) and contained a large open reading frame (ORF1) with 3513 nts. A smaller open reading frame (ORF2) with 702 nts was found in the complementary sequence. Computer analysis revealed that both ORFs did not code for the major structural proteins (VP1, 2, 3, and 4). These results suggest that VD2 has not enough information to produce progeny virions by itself. Further, the structural importance of the terminal sequence (CTS) common to both VD1 and VD2 was also predicted by a computer analysis.

  4. Van der Waals materials for the passivation of monolayer closed-packed films of CdSe quantum dots

    NASA Astrophysics Data System (ADS)

    Wang, Dennis Zi-Ren; Zhang, Datong; Creswell, Richard; Lu, Chenguang; Hu, Jiayang; Herman, Irving P.

    2015-03-01

    Van der Waals (vdW) materials are shown to protect CdSe quantum dots (QDs) from oxidization. Few-layer vdW materials, e.g. graphene and MoS2, were transferred onto a monolayer closed-packed CdSe quantum dots and were examined by photoluminescence (PL) after different time periods. By comparing the PL of CdSe QDs in uncovered areas and those covered by different numbers of layers of graphene and MoS2, we saw that vdW encapsulation slows down the aging of CdSe QDs dramatically. PL mapping results clearly showed better protection of the CdSe QDs under the central part of the vdW material compared to that at the edge; this can be explained by the diffusion of oxygen and water vapor from the edge of the vdW materials.

  5. 1α, 25-Dihydroxyvitamin D₃ and the vitamin D receptor regulates ΔNp63α levels and keratinocyte proliferation.

    PubMed

    Hill, N T; Zhang, J; Leonard, M K; Lee, M; Shamma, H N; Kadakia, M

    2015-06-11

    1α, 25-dihydroxyvitamin D3 (VD3), a secosteriod that has been explored as an anti-cancer agent, was also shown to promote cell survival. Its receptor, the Vitamin D Receptor (VDR), is a direct target of the proto-oncogene ΔNp63α, which is overexpressed in non-melanoma skin cancers. The interconnection between VDR/VD3 signaling and ΔNp63α, led us to examine whether VDR/VD3 signaling promotes keratinocyte proliferation by regulating ΔNp63α levels. Our data demonstrate that VDR regulates ΔNp63α expression at both the transcript and protein level. Interestingly, although low doses of VD3 led to an increase in ΔNp63α protein levels and keratinocyte proliferation, high doses of VD3 failed to increase ΔNp63α protein levels and resulted in reduced proliferation. Increased expression of ΔNp63α by low dose VD3 was shown to be dependent on VDR and critical for the proliferative effects of VD3. VD3-mediated increases in ΔNp63α protein levels occur via activation of both p38 MAPK and Akt kinases. Finally, analysis of samples from patients with squamous cell carcinoma (SCC), basal cell carcinoma and precursors to invasive SCC demonstrated a significant correlation between p63 and VDR levels when compared with healthy normal skin control samples. Delineation of the mechanisms by which VD3 exerts its effect on ΔNp63α and cell proliferation is critical for determining the future of VD3 in cancer therapies.

  6. Allosteric Modulation of Drp1 Mechanoenzyme Assembly and Mitochondrial Fission by the Variable Domain*

    PubMed Central

    Strack, Stefan; Cribbs, J. Thomas

    2012-01-01

    The mechanoenzyme dynamin-related protein 1 (Drp1) hydrolyzes GTP to power mitochondrial fission, a process required for organelle biogenesis, quality control, transport, and apoptosis. The pleckstrin homology domain of dynamin is essential for targeting to and severing of lipid tubules, but the function of the corresponding variable domain (VD, or insert B) of Drp1 is unknown. We replaced the VD of Drp1 with a panel of linker sequences of varying length and secondary structure composition and found that the VD is dispensable for mitochondrial recruitment, association with the Drp1-anchoring protein Mff (mitochondrial fission factor), and basal and protonophore-induced mitochondrial fragmentation. Indeed, several ΔVD mutants constitutively localized to the outer mitochondrial membrane (OMM) and fragmented mitochondria more efficiently than wild-type Drp1. Consistent with an autoinhibitory role of the VD, we identified Arg-376 in the Drp1 stalk domain as necessary for Mff interaction, assembly into spirals, and mitochondrial fission. Switching the length of N- and C-terminal α-helical segments in the VD-replacing linker converted Drp1 from constitutively active and OMM-localized to inactive and cytosolic. Other hypoactive ΔVD mutants formed stable and characteristically shaped aggregates, including extended filaments. Phosphorylation of a PKA site bordering the VD disassembled the filamentous ΔVD mutant and accelerated cytosolic diffusion of full-length Drp1. We propose a model for regulation of Drp1-dependent mitochondrial fission, in which posttranslational modifications in or near the VD alter the conformation of a membrane-proximal oligomerization interface to influence Drp1 assembly rate and/or geometry. This in turn modulates Arg-376-dependent OMM targeting of Drp1 via multivalent interactions with Mff. PMID:22334657

  7. A Prospective Validation Study of Bioimpedance with Volume Displacement in Early-Stage Breast Cancer Patients at Risk for Lymphedema

    PubMed Central

    Barrio, Andrea V.; Eaton, Anne; Frazier, Thomas G.

    2015-01-01

    BACKGROUND Although volume displacement (VD) is considered the gold standard for diagnosing breast cancer (BC)-related lymphedema, it is inconvenient. We compared bioimpedance (L-Dex) and VD measurements in a prospective cohort of BC patients at risk for lymphedema. METHODS Between 2010–2014, 223 BC patients were enrolled. Following exclusions (n=37), 186 received baseline VD and L-Dex; follow-up measurements were performed at 3–6 month intervals for 3 years. At each visit, patients fit into one of three categories: normal (normal VD and L-Dex); abnormal L-Dex (L-Dex>10 or increase in 10 from baseline and normal VD); or lymphedema (relative arm volume difference of >10% by VD +/− abnormal L-Dex). Change in L-Dex was plotted against change in VD; correlation was assessed using Pearson correlation. RESULTS At a median follow-up of 18.2mos, 152 patients were normal; 25 had an abnormal L-Dex; and 9 developed lymphedema without a prior L-Dex abnormality. Of 25 abnormal L-Dex patients, 4 progressed to lymphedema for a total of 13 patients with lymphedema. Evaluating all time points, 186 patients had 829 follow-up measurements. Sensitivity and specificity of L-Dex compared to VD were 75% and 93%, respectively. There was no correlation between change in VD and change in L-Dex at 3mos (R=0.31) or 6mos (R=0.21). CONCLUSIONS VD and bioimpedance demonstrated poor correlation with inconsistent overlap of measurements considered abnormal. Of patients with an abnormal L-Dex, few progressed to lymphedema; most with lymphedema did not have a prior L-Dex abnormality. Further studies are needed to understand the clinical significance of bioimpedance. PMID:26085222

  8. Characterization of the isoforms of type IIb sodium-dependent phosphate cotransporter (Slc34a2) in yellow catfish, Pelteobagrus fulvidraco, and their vitamin D3-regulated expression under low-phosphate conditions.

    PubMed

    Chen, Pei; Huang, Yanqing; Bayir, Abdulkadir; Wang, Chunfang

    2017-02-01

    In this study, two isoforms slc34a2 genes (type IIb sodium-dependent phosphate cotransporter), slc34a2a2 and slc34a2b, were cloned from intestine and kidney of yellow catfish (Pelteobagrus fulvidraco), with rapid amplification of cDNA ends. The structure differences and the regulation effects of dietary VD3 under low phosphorus were compared among three isoforms of slc34a2 in yellow catfish. The predicted Slc34a2a2 and Slc34a2b proteins match 65 % and 53.8 % sequence identity, with Slc34a2a1, respectively. The membrane-spanning domains were different among these three isoforms. Intestinal Slc34a2a1 and Slc34a2a2 proteins had eight and eleven transmembrane domains, while renal Slc34a2b protein had nine. The tissue distribution study showed that same as slc34a2a1, slc34a2a2 mRNA was mainly distributed in intestine and slc34a2b mRNA in kidney. The effect of vitamin D3 (VD3) level on slc34a2 subfamily expression under low-phosphate conditions, induced by the addition of 0 (VD0), 324 (VD1), 1243 (VD2), 3621 (VD3), 8040 (VD4), or 22700 (VD5) IU VD3/kg feed, was assessed by qPCR. The dose-responsive expression of intestinal slc34a2a2 and high expression of intestinal slc34a2a2 in VD5 together with peak expression of kidney slc34a2b in VD3 coincided with the accumulation of body phosphate content. These data suggested that appropriate level of dietary VD3 up-regulated slc34a2a1, slc34a2a2, and slc34a2b mRNA levels, which increased phosphate retention. In conclusion, the current study provided another possible approach to improve dietary phosphate utilization by adding appropriate level of VD3 to a low-phosphate diet to regulate intestinal and renal slc34a2 gene expression and thus minimize the excretion of phosphorus in yellow catfish.

  9. Vitamin D inhibits the occurrence of experimental cerebral malaria in mice by suppressing the host inflammatory response

    PubMed Central

    He, Xiyue; Yan, Juan; Zhu, Xiaotong; Wang, Qinghui; Pang, Wei; Qi, Zanmei; Wang, Meilian; Luo, Enjie; Parker, Daniel M.; Cantorna, Margherita T.; Cui, Liwang; Cao, Yaming

    2014-01-01

    In animal models of experimental cerebral malaria (ECM), neuropathology is associated with an overwhelming inflammatory response and sequestration of leucocytes and parasite-infected red blood cells in the brain. Here we explored the effect of vitamin D (VD, cholecalciferol) treatment on host immunity and outcome of ECM in C57BL/6 mice during Plasmodium berghei ANKA (PbA) infection. We observed that oral administration of VD both before and after PbA infection completely protected mice from ECM. VD administration significantly dampened the inducible systemic inflammatory responses with reduced circulating cytokines IFN-γ and TNF and decreased expression of these cytokines by the spleen cells. Meanwhile, VD also resulted in decreased expression of the chemokines CXCL9 and CXCL10 and cytoadhesion molecules (ICAM-1, VCAM-1 and CD36) in the brain, leading to reduced accumulation of pathogenic T cells in the brain and ultimately substantial improvement of the blood-brain barriers of PbA-infected mice. In addition, VD inhibited the differentiation, activation and maturation of splenic dendritic cells. Meanwhile, regulatory T cells and IL-10 expression levels were upregulated upon VD treatment. These data collectively demonstrated the suppressive function of VD on host inflammatory responses, which provides significant survival benefits in the murine ECM model. PMID:24965778

  10. Including screening in van der Waals corrected density functional theory calculations: The case of atoms and small molecules physisorbed on graphene

    SciTech Connect

    Silvestrelli, Pier Luigi; Ambrosetti, Alberto

    2014-03-28

    The Density Functional Theory (DFT)/van der Waals-Quantum Harmonic Oscillator-Wannier function (vdW-QHO-WF) method, recently developed to include the vdW interactions in approximated DFT by combining the quantum harmonic oscillator model with the maximally localized Wannier function technique, is applied to the cases of atoms and small molecules (X=Ar, CO, H{sub 2}, H{sub 2}O) weakly interacting with benzene and with the ideal planar graphene surface. Comparison is also presented with the results obtained by other DFT vdW-corrected schemes, including PBE+D, vdW-DF, vdW-DF2, rVV10, and by the simpler Local Density Approximation (LDA) and semilocal generalized gradient approximation approaches. While for the X-benzene systems all the considered vdW-corrected schemes perform reasonably well, it turns out that an accurate description of the X-graphene interaction requires a proper treatment of many-body contributions and of short-range screening effects, as demonstrated by adopting an improved version of the DFT/vdW-QHO-WF method. We also comment on the widespread attitude of relying on LDA to get a rough description of weakly interacting systems.

  11. Synergistic Effect of Vaginal Trauma and Ovariectomy in a Murine Model of Stress Urinary Incontinence: Upregulation of Urethral Nitric Oxide Synthases and Estrogen Receptors

    PubMed Central

    Chen, Huey-Yi; Chen, Wen-Chi; Lin, Yu-Ning

    2014-01-01

    The molecular mechanisms underlying stress urinary incontinence (SUI) are unclear. We aimed to evaluate the molecular alterations in mice urethras following vaginal trauma and ovariectomy (OVX). Twenty-four virgin female mice were equally distributed into four groups: noninstrumented control; vaginal distension (VD) group; OVX group; and VD + OVX group. Changes in leak point pressures (LPPs), genital tract morphology, body weight gain, plasma 17β-estradiol level and expressions of neuronal nitric oxide synthase (nNOS), induced nitric oxide synthase (iNOS), and estrogen receptors (ERs—ERα and ERβ) were analyzed. Three weeks after VD, the four groups differed significantly in genital size and body weight gain. Compared with the control group, the plasma estradiol levels were significantly decreased in the OVX and VD + OVX groups, and LPPs were significantly decreased in all three groups. nNOS, iNOS, and ERα expressions in the urethra were significantly increased in the VD and VD + OVX groups, whereas ERβ expression was significantly increased only in the VD + OVX group. These results show that SUI following vaginal trauma and OVX involves urethral upregulations of nNOS, iNOS, and ERs, suggesting that NO- and ER-mediated signaling might play a role in the synergistic effect of birth trauma and OVX-related SUI pathogenesis. PMID:25258476

  12. Functional analysis of autophagy genes via Agrobacterium-mediated transformation in the vascular Wilt fungus Verticillium dahliae.

    PubMed

    Zhou, Lei; Zhao, Jun; Guo, Wangzhen; Zhang, Tianzhen

    2013-08-20

    Autophagy is a widely conserved intracellular process for degradation and recycling of proteins, organelles and cytoplasm in eukaryotic organisms and is now emerging as an important process in foliar infection by many plant pathogenic fungi. However, the role of autophagy in soil-borne fungal physiology and infection biology is poorly understood. Here, we report the establishment of an Agrobacterium tumefaciens-mediated transformation (ATMT) system and its application to investigate two autophagy genes, VdATG8 and VdATG12, by means of targeted gene replacement and complementation. Transformation of a cotton-infecting Verticillium dahliae strain Vd8 with a novel binary vector pCOM led to the production of 384 geneticin-resistant transformants per 1 × 10(6) conidia. V. dahliae mutants lacking either VdATG8 or VdATG12 exhibited reduced conidiation and impaired aerial hyphae production. Disease development on Arabidopsis plants was slightly delayed when inoculated with VdATG8 or VdATG12 gene deletion mutants, compared with the wild-type and gene complemented strains. Surprisingly, in vitro inoculation with unimpaired roots revealed that the abilities of root invasion were not affected in gene deletion mutants. These results indicate that autophagy is necessary for aerial hyphae development and plant colonization but not for root infection in V. dahliae.

  13. Evidence That Loss-of-Function Filaggrin Gene Mutations Evolved in Northern Europeans to Favor Intracutaneous Vitamin D3 Production

    PubMed Central

    Thyssen, Jacob P.; Bikle, Daniel D.

    2014-01-01

    Skin pigmentation lightened progressively to a variable extent, as modern humans emigrated out of Africa, but extreme lightening occurred only in northern Europeans. Yet, loss of pigmentation alone cannot suffice to sustain cutaneous vitamin D3 (VD3) formation at the high latitudes of northern Europe. We hypothesized that loss-of-function mutations in the epidermal structural protein, filaggrin (FLG), could have evolved to sustain adequate VD3 status. Loss of FLG results in reduced generation of trans-urocanic acid, the principal endogenous ultraviolet-B (UV-B) filter in lightly-pigmented individuals. Accordingly, we identified a higher prevalence of FLG mutations in northern European populations when compared to more southern European, Asian and African populations that correlates significantly with differences in circulating 25-OH-VD3 levels in these same populations. By allowing additional UV-B penetration and intracutaneous VD3 formation, the latitude-dependent gradient in FLG mutations, likely together with other concurrent mutations in VD3 metabolic pathways, provide a non-pigment-based mechanism that sustains higher levels of circulating VD3 in northern Europeans. At the time that FLG mutations evolved, xerosis due to FLG deficiency was a lesser price to pay for enhanced VD3 production. Yet, the increase in FLG mutations has inadvertently contributed to an epidemic of atopic diseases that has emerged in recent decades. PMID:25506102

  14. Effect of vitamin D3 on production of progesterone in porcine granulosa cells by regulation of steroidogenic enzymes.

    PubMed

    Hong, So-Hye; Lee, Jae-Eon; Kim, Hong Sung; Jung, Young-Jin; Hwang, DaeYoun; Lee, Jae Ho; Yang, Seung Yun; Kim, Seung-Chul; Cho, Seong-Keun; An, Beum-Soo

    2016-05-01

    1,25-dihydroxyvitamin D3 (VD3), an active form of Vitamin D, is photosynthesized in the skin of vertebrates in response to solar ultraviolet B radiation (UV-B). VD3 deficiency can cause health problems such as immune disease, metabolic disease, and bone disorders. It has also been demonstrated that VD3 is involved in reproductive functions. Female sex hormones such as estrogen and progesterone are biosynthesized mainly in ovarian granulosa cells as the ovarian follicle develops. The functions of sex hormones include regulation of the estrus cycle and puberty as well as maintenance of pregnancy in females. In this study, we isolated granulosa cells from porcine ovaries and cultured them for experiments. To examine the effects of VD3 on ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by Real-time PCR and Western blotting assay. Production of progesterone from granulosa cells was also measured by ELISA assay. As a result, transcriptional and translational regulation of progesterone biosynthesis-related genes in granulosa cells was significantly altered by VD3. Furthermore, progesterone concentrations in porcine granulosa cell-cultured media decreased in response to VD3. These results show that VD3 was a strong regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.

  15. A hybrid mixture discriminant analysis-random forest computational model for the prediction of volume of distribution of drugs in human.

    PubMed

    Lombardo, Franco; Obach, R Scott; Dicapua, Frank M; Bakken, Gregory A; Lu, Jing; Potter, David M; Gao, Feng; Miller, Michael D; Zhang, Yao

    2006-04-06

    A computational approach is described that can predict the VD(ss) of new compounds in humans, with an accuracy of within 2-fold of the actual value. A dataset of VD values for 384 drugs in humans was used to train a hybrid mixture discriminant analysis-random forest (MDA-RF) model using 31 computed descriptors. Descriptors included terms describing lipophilicity, ionization, molecular volume, and various molecular fragments. For a test set of 23 proprietary compounds not used in model construction, the geometric mean fold-error (GMFE) was 1.78-fold (+/-11.4%). The model was also tested using a leave-class out approach wherein subsets of drugs based on therapeutic class were removed from the training set of 384, the model was recast, and the VD(ss) values for each of the subsets were predicted. GMFE values ranged from 1.46 to 2.94-fold, depending on the subset. Finally, for an additional set of 74 compounds, VD(ss) predictions made using the computational model were compared to predictions made using previously described methods dependent on animal pharmacokinetic data. Computational VD(ss) predictions were, on average, 2.13-fold different from the VD(ss) predictions from animal data. The computational model described can predict human VD(ss) with an accuracy comparable to predictions requiring substantially greater effort and can be applied in place of animal experimentation.

  16. Effect of vitamin D3 on production of progesterone in porcine granulosa cells by regulation of steroidogenic enzymes

    PubMed Central

    Hong, So-Hye; Lee, Jae-Eon; Kim, Hong Sung; Jung, Young-Jin; Hwang, DaeYoun; Lee, Jae Ho; Yang, Seung Yun; Kim, Seung-Chul; Cho, Seong-Keun; An, Beum-Soo

    2016-01-01

    Abstract 1,25-dihydroxyvitamin D3 (VD3), an active form of Vitamin D, is photosynthesized in the skin of vertebrates in response to solar ultraviolet B radiation (UV-B). VD3 deficiency can cause health problems such as immune disease, metabolic disease, and bone disorders. It has also been demonstrated that VD3 is involved in reproductive functions. Female sex hormones such as estrogen and progesterone are biosynthesized mainly in ovarian granulosa cells as the ovarian follicle develops. The functions of sex hormones include regulation of the estrus cycle and puberty as well as maintenance of pregnancy in females. In this study, we isolated granulosa cells from porcine ovaries and cultured them for experiments. To examine the effects of VD3 on ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by Real-time PCR and Western blotting assay. Production of progesterone from granulosa cells was also measured by ELISA assay. As a result, transcriptional and translational regulation of progesterone biosynthesis-related genes in granulosa cells was significantly altered by VD3. Furthermore, progesterone concentrations in porcine granulosa cell-cultured media decreased in response to VD3. These results show that VD3 was a strong regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss. PMID:27533930

  17. Effect of vitamin D on bioavailability and lipid lowering efficacy of simvastatin.

    PubMed

    Al-Asmari, Abdulrahman K; Ullah, Zabih; Al-Sabaan, Fahad; Tariq, Mohammad; Al-Eid, Ahmed; Al-Omani, Saud F

    2015-03-01

    The 3-hydroxy 3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) inhibitors known as "statins" are widely prescribed for the management of dyslipidemia. In spite of their muscle toxicity, use of statins has alarmingly increased worldwide. A recent report suggests that vitamin D (VD) levels are closely associated with lipid lowering activity and muscular toxicity of statins. However, data are limited and inconclusive. The present study was undertaken to investigate the effect of VD supplementation on the bioavailability and lipid lowering effect of simvastatin (ST). Adult Sprague-Dawley male rats (250 ± 10 g) were divided into four groups including control, ST (100 mg/kg/day), VD (100 μg/kg/day) and ST + VD group, respectively. After the dosing period of 8 days the animals were sacrificed and the blood was collected for the analysis of ST, its active metabolite simvastatin acid (STA), total cholesterol, triglyceride and liver enzymes including aspartate transaminase and alanine transaminase. The result of this study showed a significant decrease in the level of cholesterol and triglyceride in ST alone treated group, whereas VD alone failed to alter the blood lipid levels. Concomitant treatment with VD produced significant decrease in the bioavailability of ST and STA. However, there was no significant difference in the level of cholesterol in ST alone and in ST + VD treated group. Our results on the liver enzyme suggest that ST alone or in combination with VD does not produce any hepatotoxicity. Further studies using VD along with various statins for a longer duration are suggested.

  18. Stress and vitamin D: altered vitamin D metabolism in both the hippocampus and myocardium of chronic unpredictable mild stress exposed rats.

    PubMed

    Jiang, Pei; Zhang, Wen-Yuan; Li, Huan-De; Cai, Hua-Lin; Liu, Yi-Ping; Chen, Lin-Yao

    2013-10-01

    Exposure to stressful life events is associated with the onset of major depression and increases the risk of cardiac morbidity and mortality. While recent evidence has indicated the existence of an interrelationship between local vitamin D (VD) metabolism and many aspects of human physiology including brain and heart function, much is still unknown concerning the biological link between VD signaling and stress-induced depressive behavior and cardiac dysfunction. In the present study, we observed the VD intracrine system in the hippocampus and myocardium of chronic unpredictable mild stress (CUMS) exposed rats. After 4 weeks of CUMS procedure, rats were induced to a depressive-like state and the cytochromes P450 enzymes involved in VD activating and catabolizing (CYP27B1 and CYP24A1 respectively) and VD receptor (VDR) were assessed by real time RT-PCR and western blot in the hippocampus, myocardium and kidney. In the hippocampus of depressed rats, CYP27B1, CYP24A1 and VDR expression were significantly increased and the local status of 1,25-dihydroxyvitamin D (1,25(OH)2D) was higher compared with controls. Furthermore, hippocampal mRNA levels of VD target genes (calbindin-d28k, neurotrophin-3) and RXRα (heterodimeric partner of VDR) were upregulated in response to chronic stress. Similar to the hippocampus, CUMS also induced CYP27B1/CYP24A1/VDR expression in the myocardium. However, renal metabolism of VD and serum1,25(OH)2D status were unchanged. Meanwhile, sertraline treatment could partly normalize the stress-induced alterations of VD metabolism. In conclusion, this study firstly showed a co-elevated expression of CYP27B1/CYP24A1/VDR in both the hippocampus and myocardium of CUMS rats, which suggests VD signaling may be involved in the compensatory mechanism that protect from stress-induced deteriorating effects on the brain and heart.

  19. Comparing van der Waals DFT methods for water on NaCl(001) and MgO(001)

    NASA Astrophysics Data System (ADS)

    Kebede, Getachew G.; Spângberg, Daniel; Mitev, Pavlin D.; Broqvist, Peter; Hermansson, Kersti

    2017-02-01

    In this work, a range of van der Waals type density functionals are applied to the H2O/NaCl(001) and H2O/MgO(001) interface systems to explore the effect of an explicit dispersion treatment. The functionals we use are the self-consistent vdW functionals vdW-DF, vdW-DF2, optPBE-vdW, optB88-vdW, optB86b-vdW, and vdW-DF-cx, as well as the dispersion-corrected PBE-TS and PBE-D2 methods; they are all compared with the standard PBE functional. For both NaCl(001) and MgO(001), we find that the dispersion-flavoured functionals stabilize the water-surface interface by approximately 20%-40% compared to the PBE results. For NaCl(001), where the water molecules remain intact for all overlayers, the dominant contribution to the adsorption energy from "density functional theory dispersion" stems from the water-surface interactions rather than the water-water interactions. The optPBE-vdW and vdW-DF-cx functionals yield adsorption energies in good agreement with available experimental values for both NaCl and MgO. To probe the strengths of the perturbations of the adsorbed water molecules, we also calculated water dipole moments and found an increase up to 85% for water at the MgO(001) surface and 70% at the NaCl(001) surface, compared to the gas-phase dipole moment.

  20. 1α,25-dihydroxyvitamin D3 modulates the hair-inductive capacity of dermal papilla cells: therapeutic potential for hair regeneration.

    PubMed

    Aoi, Noriyuki; Inoue, Keita; Chikanishi, Toshihiro; Fujiki, Ryoji; Yamamoto, Hanako; Kato, Harunosuke; Eto, Hitomi; Doi, Kentaro; Itami, Satoshi; Kato, Shigeaki; Yoshimura, Kotaro

    2012-08-01

    Dermal papilla cells (DPCs) have the potential to induce differentiation of epithelial stem cells into hair, and Wnt signaling is deeply involved in the initiation process. The functional limitation of expanded adult DPCs has been a difficult challenge for cell-based hair regrowth therapy. We previously reported that 1α,25-dihydroxyvitamin D(3) (VD(3)) upregulates expression of transforming growth factor (TGF)-β2 and alkaline phosphatase (ALP) activity, both features of hair-inducing human DPCs (hDPCs). In this study, we further examined the effects and signaling pathways associated with VD(3) actions on DPCs. VD(3) suppressed hDPC proliferation in a dose-dependent, noncytotoxic manner. Among the Wnt-related genes investigated, Wnt10b expression was significantly upregulated by VD(3) in hDPCs. Wnt10b upregulation, as well as upregulation of ALPL (ALP, liver/bone/kidney) and TGF-β2, by VD(3) was specific in hDPCs and not detected in human dermal fibroblasts. Screening of paracrine or endocrine factors in the skin indicated that all-trans retinoic acid (atRA) upregulated Wnt10b gene expression, although synergistic upregulation (combined atRA and VD(3)) was not seen. RNA interference with vitamin D receptor (VDR) revealed that VD(3) upregulation of Wnt10b, ALPL, and TGF-β2 was mediated through the genomic VDR pathway. In a rat model of de novo hair regeneration by murine DPC transplantation, pretreatment with VD(3) significantly enhanced hair folliculogenesis. Specifically, a greater number of outgrowing hair shafts and higher maturation of regenerated follicles were observed. Together, these data suggest that VD(3) may promote functional differentiation of DPCs and be useful in preserving the hair follicle-inductive capacity of cultured DPCs for hair regeneration therapies.

  1. Novel Infection System of Recombinant BmBDV DNA into BmN Cells of Silkworm, Bombyx mori.

    PubMed

    Guo, Rui; Cao, Guangli; Zhu, Yuexiong; Kumar, Dhiraj; Xue, Renyu; Lu, Yahong; Hu, Xiaolong; Gong, Chengliang

    2016-10-01

    Bombyx mori bidensovirus (BmBDV) was previously termed as Bombyx mori densovirus type 2 and later it was reclassified in the new genus bidensovirus of the new family Bidnaviridae. The genome of BmBDV Zhenjiang isolate (BmBDV-Z) consists of two non-homologous single-stranded linear DNA molecules VD1 and VD2 which are encapsidated into separate virion. To investigate the infectivity of BmBDV DNA, recombinant plasmids pGEM-VD1 inserted with VD1 genome were transfected into the BmN cells of silkworm. Structural proteins of BmBDV were detected with Western blot and immunofluorescence assay, which indicates pGEM-VD1 replicated in the transfected BmN cells and viral proteins were also expressed. Through TEM observation, we identified about 20 nm BmBDV-like viral particles, which confirmed that BmBDV can be generated after transfection. Subsequently, a recombinant baculovirus BmBac-VD1 inserted with VD1 genome was constructed. Results of Western blot and immunofluorescence assay indicated that viral structural proteins of BmBDV were expressed in the BmBac-VD1-infected cells. Baculiform and spherical virions were also observed in infected cells by TEM, and two kinds of virions were separated. However, results of molecular biological detection revealed that infectious sequence from BmBac-VD1 was packaged within spherical virion. Therefore, we suggested that vector inserted with BmBDV genomic DNA showed infectivity, and BmBDV-like viral particles packaging recombinant DNA can be produced in the cultured BmN cells. Outcome of our current research provided not only a new method of infection to explore the gene function of BmBDV in vitro but also a protocol to facilitate development of more effective new-type pesticides.

  2. Comparing van der Waals DFT methods for water on NaCl(001) and MgO(001).

    PubMed

    Kebede, Getachew G; Spångberg, Daniel; Mitev, Pavlin D; Broqvist, Peter; Hermansson, Kersti

    2017-02-14

    In this work, a range of van der Waals type density functionals are applied to the H2O/NaCl(001) and H2O/MgO(001) interface systems to explore the effect of an explicit dispersion treatment. The functionals we use are the self-consistent vdW functionals vdW-DF, vdW-DF2, optPBE-vdW, optB88-vdW, optB86b-vdW, and vdW-DF-cx, as well as the dispersion-corrected PBE-TS and PBE-D2 methods; they are all compared with the standard PBE functional. For both NaCl(001) and MgO(001), we find that the dispersion-flavoured functionals stabilize the water-surface interface by approximately 20%-40% compared to the PBE results. For NaCl(001), where the water molecules remain intact for all overlayers, the dominant contribution to the adsorption energy from "density functional theory dispersion" stems from the water-surface interactions rather than the water-water interactions. The optPBE-vdW and vdW-DF-cx functionals yield adsorption energies in good agreement with available experimental values for both NaCl and MgO. To probe the strengths of the perturbations of the adsorbed water molecules, we also calculated water dipole moments and found an increase up to 85% for water at the MgO(001) surface and 70% at the NaCl(001) surface, compared to the gas-phase dipole moment.

  3. Thermal instability theory analysis of multifaceted asymmetric radiation from the edge (MARFE) in Tokamak Experiment for Technology Oriented Research (TEXTOR)

    SciTech Connect

    Kelly, F. A.; Stacey, W. M.; Rapp, J.; Brix, M.

    2001-07-01

    The density limits for a series of shots in TEXTOR [Tokamak Experiment for Technology Oriented Research, E. Hintz, P. Bogen, H. A. Claa{ss}en , in Contributions to High-Temperature Plasma Physics, edited by K. H. Spatschek and J. Uhlenbusch (Akademie Verlag, Berlin, 1994, p. 373)], over a range of heating powers, that ended in multifaceted asymmetric radiation from the edge (MARFE) have been analyzed within the context of thermal instability theory. The prediction of MARFE onset agrees with observation to within the experimental uncertainty.

  4. Interlayer coupling effects on Schottky barrier in the arsenene-graphene van der Waals heterostructures

    SciTech Connect

    Xia, Congxin Xue, Bin; Wang, Tianxing; Peng, Yuting; Jia, Yu

    2015-11-09

    The electronic characteristics of arsenene-graphene van der Waals (vdW) heterostructures are studied by using first-principles methods. The results show that a linear Dirac-like dispersion relation around the Fermi level can be quite well preserved in the vdW heterostructures. Moreover, the p-type Schottky barrier (0.18 eV) to n-type Schottky barrier (0.31 eV) transition occurs when the interlayer distance increases from 2.8 to 4.5 Å, which indicates that the Schottky barrier can be tuned effectively by the interlayer distance in the vdW heterostructures.

  5. A Local Parabolic Method for Long Distance Wave Propagation

    DTIC Science & Technology

    2005-09-21

    centroid motion and total integrated amplitude at each point along the pulse surface. The main issue in computing these cases is that conventional...This is necessary because the Lattice Confinement terms should not depend on the scale of the quantity being confined. Another important point is that...4,VD2 2+ E5,VD xb where b is a local harmonic mean of 3 at each grid point : B~f FI N’ where 6, and VD denote discrete operators and Eqn. 1.2 was

  6. Quantitative Understanding of van der Waals Interactions by Analyzing the Adsorption Structure and Low-Frequency Vibrational Modes of Single Benzene Molecules on Silver.

    PubMed

    Yuan, Dingwang; Han, Zhumin; Czap, Gregory; Chiang, Chi-Lun; Xu, Chen; Ho, W; Wu, Ruqian

    2016-06-16

    The combination of a sub-Kelvin scanning tunneling microscope and density functional calculations incorporating van der Waals (vdW) corrections has been used successfully to probe the adsorption structure and low-frequency vibrational modes of single benzene molecules on Ag(110). The inclusion of optimized vdW functionals and improved C6-based vdW dispersion schemes in density functional theory is crucial for obtaining the correct adsorption structure and low-energy vibrational modes. These results demonstrate the emerging capability to quantitatively probe the van der Waals interactions between a physisorbed molecule and an inert substrate.

  7. Towards an accurate description of perovskite ferroelectrics: exchange and correlation effects

    PubMed Central

    Yuk, Simuck F.; Pitike, Krishna Chaitanya; Nakhmanson, Serge M.; Eisenbach, Markus; Li, Ying Wai; Cooper, Valentino R.

    2017-01-01

    Using the van der Waals density functional with C09 exchange (vdW-DF-C09), which has been applied to describing a wide range of dispersion-bound systems, we explore the physical properties of prototypical ABO3 bulk ferroelectric oxides. Surprisingly, vdW-DF-C09 provides a superior description of experimental values for lattice constants, polarization and bulk moduli, exhibiting similar accuracy to the modified Perdew-Burke-Erzenhoff functional which was designed specifically for bulk solids (PBEsol). The relative performance of vdW-DF-C09 is strongly linked to the form of the exchange enhancement factor which, like PBEsol, tends to behave like the gradient expansion approximation for small reduced gradients. These results suggest the general-purpose nature of the class of vdW-DF functionals, with particular consequences for predicting material functionality across dense and sparse matter regimes. PMID:28256544

  8. Cortical microtubule as a sensor and target of nitric oxide signal during the defence responses to Verticillium dahliae toxins in Arabidopsis.

    PubMed

    Shi, Fu-Mei; Yao, Lin-Lin; Pei, Bao-Lei; Zhou, Qun; Li, Xiu-Li; Li, Yun; Li, Ying-Zhang

    2009-04-01

    The molecular mechanisms of signal transduction of plants in response to Verticillium dahliae (VD) are not known. Here, we show that Arabidopsis reacts to VD-toxins with a rapid burst of nitric oxide (NO) and cortical microtubule destabilization. VD-toxins treatment triggered a disruption of cortical microtubules network. This disruption can be influenced by NO production. However, cortical microtubule disruptions were not involved in regulating the NO production. The results indicated that NO may act as an upstream signalling molecule to trigger the depolymerization of cortical microtubule. Cortical microtubules may act as a target of NO signal and as a sensor to mediate the activation of PR-1 gene expression. These results suggested that NO production and cortical microtubule dynamics appeared to be parts of the important signalling system and are involved in the defence mechanisms to VD-toxins in Arabidopsis.

  9. Electrically Tunable van der Waals Interaction in Graphene-Molecule Complex.

    PubMed

    Muruganathan, Manoharan; Sun, Jian; Imamura, Tomonori; Mizuta, Hiroshi

    2015-12-09

    van der Waals (vdW) interactions play a central role in the surface-related physics and chemistry. Tuning of the correlated charge fluctuation in a vdW complex is a plausible way of modulating the molecules interaction at the atomic surface. Here, we report the vdW interaction tunability of the graphene-CO2 complex by combining the first-principles calculations with the vdW density functionals and the time evaluation measurements of CO2 molecules adsorption/desorption on graphene under an external electric field. The field-dependent charge transfer within the complex unveils the controllable tuning of CO2 from acceptor to donor. Meanwhile, the configuration of the adsorbed molecule, the equilibrium distance from graphene and O-C-O bonding angle, is modified accordingly. The range of electrical tunability is a unique feature for each type of molecule.

  10. Van der Waals density functional: An appropriate exchange functional

    NASA Astrophysics Data System (ADS)

    Cooper, Valentino R.

    2010-04-01

    In this Rapid Communication, an exchange functional which is compatible with the nonlocal Rutgers-Chalmers correlation functional [van der Waals density functional (vdW-DF)] is presented. This functional, when employed with vdW-DF, demonstrates remarkable improvements on intermolecular separation distances while further improving the accuracy of vdW-DF interaction energies. The key to the success of this three-parameter functional is its reduction in short-range exchange repulsion through matching to the gradient expansion approximation in the slowly varying/high-density limit while recovering the large reduced gradient, s , limit set in the revised Perdew-Burke-Ernzerhof (revPBE) exchange functional. This augmented exchange functional could be a solution to long-standing issues of vdW-DF lending to further applicability of density-functional theory to the study of relatively large, dispersion bound (van der Waals) complexes.

  11. Continuous and discontinuous absorbing-state phase transitions on Voronoi-Delaunay random lattices

    NASA Astrophysics Data System (ADS)

    de Oliveira, Marcelo M.; Alves, Sidiney G.; Ferreira, Silvio C.

    2016-01-01

    We study absorbing-state phase transitions (APTs) in two-dimensional Voronoi-Delaunay (VD) random lattices with quenched coordination disorder. Quenched randomness usually changes the criticality and destroys discontinuous transitions in low-dimensional nonequilibrium systems. We performed extensive simulations of the Ziff-Gulari-Barshad model, and verified that the VD disorder does not change the nature of its discontinuous transition. Our results corroborate recent findings of Barghathi and Vojta [H. Barghathi and T. Vojta, Phys. Rev. Lett. 113, 120602 (2014), 10.1103/PhysRevLett.113.120602], stating the irrelevance of topological disorder in a class of random lattices that includes VD, and raise the interesting possibility that disorder in nonequilibrium APT may, under certain conditions, be irrelevant for the phase coexistence. We also verify that the VD disorder is irrelevant for the critical behavior of models belonging to the directed percolation and Manna universality classes.

  12. Recognition of DNA sequencing through binding of nucleobases to graphene

    NASA Astrophysics Data System (ADS)

    Zaffino, Valentina

    Graphene is one of the most promising materials in nanotechnology. Its large surface to volume ratio, high conductivity and electron mobility at room temperature are outstanding properties for use in DNA sensors. For this study, we used Density Functional Theory (DFT), ?with and without the inclusion of van der Waals (vdW) interactions, ?to investigate the adsorption of nucleobases (cytosine, guanine, adenine, thymine, and uracil) on pristine graphene and graphene with defects (Divacancy and Stone-Wales). We investigated the performance of two types of vdW-DF functional (optB86b-vdW and rPW86-vdW), as well as the PBE functional, and their description of the adsorption geometry and electronic structure of the nucleobase-graphene systems.The inclusion of defects results in an increase in binding energy, closer adsorption of the molecule to graphene and greater buckling in both the graphene structure and nucleobase.

  13. [One point determination of oral caffeine clearance in patients with liver diseases].

    PubMed

    Richter, E; Brachtel, D; Hofstetter, G; Joeres, R; Klinker, H; Junggeburth, J; Epping, J; Zilly, W

    1988-12-01

    Caffeine clearance has been determined in 117 volunteers and patients (including 27 patients with liver cirrhosis) after oral application of 366.1 mg caffeine according to conventional pharmacokinetic methods (Cl = D/AUC). The resulting clearance values can be estimated with adequate accuracy from the plasma concentration at 12h for a concentration range of 2.0 to 6.5 mg/l according to Cl max = Doses/C 12h x t 12h x e and for concentrations higher than 6.5 mg/l according to Cl = Vd x (1n (D/Vd) - 1n C 12h/t 12h Vd is estimated from body weight as Vd = 0.42 x BW. "One - point" - estimation does not provide reliable data for plasma concentrations below 2.0 mg/l.

  14. The Impact of Inflammatory and Infectious Diseases of Vulvar on Quality of Life

    PubMed Central

    Özyurt, Selçuk; Özkan, Bülent; Karaca, Şemsettin; Karakuzu, Ali; Bilgin, İlgül

    2016-01-01

    Objectives This study aimed to evaluate the effects of vulvar dermatoses (VD) and vulvar infections (VE) on anxiety, depression scores, general, and dermatological quality of life (QOL) of women. Methods We conducted a cross-sectional survey on patients diagnosed with VD and VE. All patients were assessed using a sociodemographic form, Skindex-29 scale, World Health Organization QOL (WHOQOL) BREF scale, Hamilton anxiety rating scale (HAM-A), Hamilton depression rating scale (HAM-D). Results HAM-A score was significantly higher in the VD group than in the control group. Based on age groups, all subscales of Skindex-29 were found to be higher in women > 50 years. For women with severe pruritus, the symptom subscale was higher in patients with skin involvement and the function and emotion subscales were higher in patients with and emotion subscales were higher in patients with mucosal involvement. Conclusions We found that VD was particularly significantly associated with decreased QOL. PMID:28119892

  15. Towards an accurate description of perovskite ferroelectrics: exchange and correlation effects.

    PubMed

    Yuk, Simuck F; Pitike, Krishna Chaitanya; Nakhmanson, Serge M; Eisenbach, Markus; Li, Ying Wai; Cooper, Valentino R

    2017-03-03

    Using the van der Waals density functional with C09 exchange (vdW-DF-C09), which has been applied to describing a wide range of dispersion-bound systems, we explore the physical properties of prototypical ABO3 bulk ferroelectric oxides. Surprisingly, vdW-DF-C09 provides a superior description of experimental values for lattice constants, polarization and bulk moduli, exhibiting similar accuracy to the modified Perdew-Burke-Erzenhoff functional which was designed specifically for bulk solids (PBEsol). The relative performance of vdW-DF-C09 is strongly linked to the form of the exchange enhancement factor which, like PBEsol, tends to behave like the gradient expansion approximation for small reduced gradients. These results suggest the general-purpose nature of the class of vdW-DF functionals, with particular consequences for predicting material functionality across dense and sparse matter regimes.

  16. Towards an accurate description of perovskite ferroelectrics: exchange and correlation effects

    DOE PAGES

    Yuk, Simuck F.; Pitike, Krishna Chaitanya; Nakhmanson, Serge M.; ...

    2017-03-03

    Using the van der Waals density functional with C09 exchange (vdW-DF-C09), which has been applied to describing a wide range of dispersion-bound systems, we explore the physical properties of prototypical ABO3 bulk ferroelectric oxides. Surprisingly, vdW-DF-C09 provides a superior description of experimental values for lattice constants, polarization and bulk moduli, exhibiting similar accuracy to the modified Perdew-Burke-Erzenhoff functional which was designed specifically for bulk solids (PBEsol). The relative performance of vdW-DF-C09 is strongly linked to the form of the exchange enhancement factor which, like PBEsol, tends to behave like the gradient expansion approximation for small reduced gradients. These results suggestmore » the general-purpose nature of the class of vdW-DF functionals, with particular consequences for predicting material functionality across dense and sparse matter regimes.« less

  17. Osteo-maturation of adipose-derived stem cells required the combined action of vitamin D3, beta-glycerophosphate, and ascorbic acid.

    PubMed

    Gupta, Anurag; Leong, David Tai; Bai, Hui Fen; Singh, Shiv Brat; Lim, Thiam-Chye; Hutmacher, Dietmar Werner

    2007-10-12

    This study investigated the effects of various components [vitamin D3 (VD3), beta-glycerophosphate (BGP), and ascorbic acid (AA)] on the potential of human adipose-derived progenitor cells (ADPCs) to transdifferentiate into osteoblast-like cells. ADPCs were induced under four different supplement groups: (1) VD3+BGP+AA, (2) VD3 alone, (3) BGP+AA, and (4) no VD3, BGP or AA. Mineralization studies and presence of bone matrix-related proteins by immunostaining showed that the Group 1 ADPCs showed their ability to undergo osteoblastic differentiation. Further evaluation was made by estimation of levels of RUNX-2 and TAZ genes. Group 1 ADPCs showed the consistent expression of RUNX-2 and TAZ levels over the study period of 28days. The study showed good correlation among various parameters evaluated to conclude that ADPCs could be an alternative source for generating osteoblast-like cells.

  18. Projectile Impact Effects on Aircraft Wire Harnesses

    DTIC Science & Technology

    1986-01-08

    ity, tNaVdI Air Syswems Coruiiina, Wosniln~ton, UC 20jul. Lnri neem inj, Support Office, fidval Air Station, Norfolk, VA. ~. Klixun Circuit breakers, Texas Instruiiients, Inc., circuift Ereaker Products Publication 249. 41

  19. Comparative van der Waals density-functional study of graphene on metal surfaces

    NASA Astrophysics Data System (ADS)

    Hamada, Ikutaro; Otani, Minoru

    2010-10-01

    We present a comparative van der Waals density-functional (vdW-DF) study of graphene adsorbed on (111) surfaces of Ni, Cu, Pd, Ag, Au, and Pt, using the second version of vdW-DF (vdW-DF2) of Lee [Phys. Rev. B 82, 081101(R) (2010)]10.1103/PhysRevB.82.081101 and the exchange functional (C09) developed by Cooper [Phys. Rev. B 81, 161104(R) (2010)]10.1103/PhysRevB.81.161104. We show that the use of the vdW-DF2 correlation together with the C09 exchange yields the most satisfactory results: Adsorption geometries of graphene are in good agreement with available experiment data, and the electronic structure of graphene varies depending on the nature of the substrate. Band-gap opening at the K point observed on the Ni(111) surface is reproduced reasonably well.

  20. Electric field modulation of Schottky barrier height in graphene/MoSe{sub 2} van der Waals heterointerface

    SciTech Connect

    Sata, Yohta; Moriya, Rai E-mail: tmachida@iis.u-tokyo.ac.jp; Morikawa, Sei; Yabuki, Naoto; Masubuchi, Satoru; Machida, Tomoki E-mail: tmachida@iis.u-tokyo.ac.jp

    2015-07-13

    We demonstrate a vertical field-effect transistor based on a graphene/MoSe{sub 2} van der Waals (vdW) heterostructure. The vdW interface between the graphene and MoSe{sub 2} exhibits a Schottky barrier with an ideality factor of around 1.3, suggesting a high-quality interface. Owing to the low density of states in graphene, the position of the Fermi level in the graphene can be strongly modulated by an external electric field. Therefore, the Schottky barrier height at the graphene/MoSe{sub 2} vdW interface is also modulated. We demonstrate a large current ON-OFF ratio of 10{sup 5}. These results point to the potential high performance of the graphene/MoSe{sub 2} vdW heterostructure for electronics applications.

  1. Common 1H-MRS Characteristics in Patients With Alzheimer's Disease and Vascular Dementia Diagnosed With Kidney Essence Deficiency Syndrome: A Preliminary Study.

    PubMed

    Guo, Zhongwei; Liu, Xiaozheng; Cao, Yulin; Hou, Hongtao; Chen, Xingli; Chen, Yongcan; Huang, Feihua; Chen, Wei

    2017-02-27

    Context • Traditional Chinese medicine (TCM) indicates that both Alzheimer's disease (AD) and vascular dementia (VD) should be categorized as dementia and that they have a common etiology and pathogenesis under TCM classification of syndromes, such as with kidney essence deficiency syndrome (KEDS). The pathological location is mainly in the brain. However, it remains unclear whether AD and VD patients with KEDS exhibit a metabolic commonality in the same region of the brain. Objective • The study intended to investigate the metabolic characteristics of the brain using proton magnetic resonance spectroscopy (1H-MRS) in patients with AD and VD who had been diagnosed with KEDS. Design • The research team designed a pilot study, with the participants being allocated to 3 groups: (1) an AD group, (2) a VD group, and (3) a control group. All data analysis was carried out by a trained radiologist who was blinded to each participant's diagnosis. Setting • The study took place at the Tongde Hospital of Zhejiang Province (Zhejiang Sheng, China). Participants • Participants were patients at the Tongde Hospital with mild AD or VD who had been diagnosed with KEDS. The normal controls were patients' spouses or guardians with normal cognitive function. Outcome Measures • All participants underwent 1H-MRS. The N-acetyl aspartate (NAA)/myo-inositol (mI), NAA/creatine (Cr), choline (Cho)/Cr, and mI/Cr ratios were bilaterally measured in the posterior cingulate gyrus (PCG) and anterior cingulate gyrus (ACG) by the Syngo spectroscopy postprocessing package. Demographic characteristics and 1H-MRS data were assessed across the AD, VD, and normal control groups. Results • Thirteen patients with mild AD with KEDS, 15 patients with mild VD with KEDS, and 18 normal controls were recruited from May 2013 through May 2014. The AD and VD groups did not significantly differ in the NAA/mI, NAA/Cr, Cho/Cr, and mI/Cr ratios in either the PCG or the ACG, with the exception being the

  2. [Clinical aspects of vibration disease caused by general vibration].

    PubMed

    Tarasova, L A; Lagutina, G N; Komleva, L M; Suvorov, G A; Starozhuk, I A; Filatova, O V

    1989-01-01

    The clinico-functional examination of agricultural machine-operators, truck drivers, excavator and boring machine operators revealed that, under low-frequency general vibration, polymorphic pathologic changes occur in human organism. Those include peripheral vascular and neuritic disorders and changes in the vertebral column. The most peculiar symptoms of VD are dealt with. The data obtained show to the importance of further elaboration of differential diagnostic criteria of VD, specifying its pathogenic mechanisms and prevention measures working out.

  3. Targeted delivery of vitamin D3-loaded nanoparticles to C6 glioma cell line increased resistance to doxorubicin, epirubicin, and docetaxel in vitro.

    PubMed

    Maleklou, Nargess; Allameh, Abdolamir; Kazemi, Bahram

    2016-12-01

    In recent years, targeted delivery systems have been used along with combinatorial therapy to decrease drug resistance and increase cancer therapy efficacy. The anti-proliferative effects of vitamin D3 (VD3) on cancerous cells, such as C6 glioma, with active hedgehog pathways raised the question as to whether pre-targeting C6 glioma cells with VD3-loaded nanoparticles (VD3NPs) can enhance the anti-tumor effects of doxorubicin, epirobicin, and docetaxel on this drug-resistant cell line. Here, studying at cellular, nuclear, protein, and gene levels we demonstrated that VD3NP-doxorubicin and VD3NP-epirobicin combinations increased the probability of chemotherapy/radiotherapy resistance and cancer stem cell (CSC) properties in C6 glioma significantly (P < 0.05), compared to doxorubicin and epirobicin alone. However, VD3NP-docetaxel combination may have the potential in sensitizing C6 cells to ionizing irradiation, but this combination also increased the CSC properties and the probability of drug resistance significantly (P < 0.05), compared to docetaxel alone. Although our previous study showed that targeted delivery of VD3 reduced the rate of proliferation significantly (P < 0.05) in C6 glioma cells (a drug-resistant cell line), here we concluded that combinatorial therapy of exogenous VD3 with doxorubicin, epirobicin, and docetaxel not only did not lead to the enhancement of cytotoxic effects of the aforementioned drugs but also increased the cancerous characteristics in C6 glioma, in vitro.

  4. Van der Waals coefficients beyond the classical shell model

    SciTech Connect

    Tao, Jianmin; Fang, Yuan; Hao, Pan; Scuseria, G. E.; Ruzsinszky, Adrienn; Perdew, John P.

    2015-01-14

    Van der Waals (vdW) coefficients can be accurately generated and understood by modelling the dynamic multipole polarizability of each interacting object. Accurate static polarizabilities are the key to accurate dynamic polarizabilities and vdW coefficients. In this work, we present and study in detail a hollow-sphere model for the dynamic multipole polarizability proposed recently by two of the present authors (JT and JPP) to simulate the vdW coefficients for inhomogeneous systems that allow for a cavity. The inputs to this model are the accurate static multipole polarizabilities and the electron density. A simplification of the full hollow-sphere model, the single-frequency approximation (SFA), circumvents the need for a detailed electron density and for a double numerical integration over space. We find that the hollow-sphere model in SFA is not only accurate for nanoclusters and cage molecules (e.g., fullerenes) but also yields vdW coefficients among atoms, fullerenes, and small clusters in good agreement with expensive time-dependent density functional calculations. However, the classical shell model (CSM), which inputs the static dipole polarizabilities and estimates the static higher-order multipole polarizabilities therefrom, is accurate for the higher-order vdW coefficients only when the interacting objects are large. For the lowest-order vdW coefficient C{sub 6}, SFA and CSM are exactly the same. The higher-order (C{sub 8} and C{sub 10}) terms of the vdW expansion can be almost as important as the C{sub 6} term in molecular crystals. Application to a variety of clusters shows that there is strong non-additivity of the long-range vdW interactions between nanoclusters.

  5. CCD Photometry of the Open Cluster Tombaugh 5 in the Vilnius System

    DTIC Science & Technology

    2011-01-01

    Collinder 428 (Laugalys et ai. 2007) and IC 361 (Zdanavicius et al. 2010), and four areas in the dark cloud LDN 935 at the North America and Pelican nebulae ...based on the Dobashi et a!. (2005) atlas of dark clouds (TGU numbers) and shows the positions of the nebulae Sh2-202, Sh2-205, vdB 14 and vdB 15, the

  6. Dynamical screening of van der Waals interactions in nanostructured solids: Sublimation of fullerenes

    NASA Astrophysics Data System (ADS)

    Tao, Jianmin; Yang, Jing; Rappe, Andrew M.

    2015-04-01

    Sublimation energy is one of the most important properties of molecular crystals, but it is difficult to study, because the attractive long-range van der Waals (vdW) interaction plays an important role. Here, we apply efficient semilocal density functional theory (DFT), corrected with the dynamically screened vdW interaction (DFT + vdW), the Rutgers-Chalmers nonlocal vdW-DF, and the pairwise-based dispersion-corrected DFT-D2 developed by Grimme and co-workers, to study the sublimation of fullerenes. We find that the short-range part, which accounts for the interaction due to the orbital overlap between fullerenes, is negligibly small. Our calculation shows that there exists a strong screening effect on the vdW interaction arising from the valence electrons of fullerenes. On the other hand, higher-order contributions can be as important as the leading-order term. The reasons are that (i) the surface of fullerene molecules is metallic and thus highly polarizable, (ii) the band gap of fullerene solids is small (less than 2 eV), and (iii) fullerene molecules in the solid phase are so densely packed, yielding the high valence electron density and small equilibrium intermolecular distances (the first nearest neighbor distance is only about 10 Å for C60). However, these two effects make opposite contributions, leading to significant error cancellation between these two contributions. We demonstrate that, by considering higher-order contributions and the dynamical screening, the DFT + vdW method can yield sublimation energies of fullerenes in good agreement with reference values, followed by vdW-DF and DFT-D2. The insights from this study are important for a better understanding of the long-range nature of vdW interactions in nanostructured solids.

  7. Regulatory Mechanisms of Vitamin D3 on Production of Nitric Oxide and Pro-inflammatory Cytokines in Microglial BV-2 Cells.

    PubMed

    Dulla, Yevgeny Aster T; Kurauchi, Yuki; Hisatsune, Akinori; Seki, Takahiro; Shudo, Koichi; Katsuki, Hiroshi

    2016-11-01

    Inhibition of pro-inflammatory functions of microglia has been considered a promising strategy to prevent pathogenic events in the central nervous system under neurodegenerative conditions. Here we examined potential inhibitory effects of nuclear receptor ligands on lipopolysaccharide (LPS)-induced inflammatory responses in microglial BV-2 cells. We demonstrate that a vitamin D receptor agonist 1,25-dihydroxyvitamin D3 (VD3) and a retinoid X receptor agonist HX630 affect LPS-induced expression of pro-inflammatory factors. Specifically, both VD3 and HX630 inhibited expression of mRNAs encoding inducible nitric oxide synthase (iNOS) and IL-6, whereas expression of IL-1β mRNA was inhibited only by VD3. The inhibitory effect of VD3 and HX630 on expression of iNOS and IL-6 mRNAs was additive. Effect of VD3 and HX630 was also observed for inhibition of iNOS protein expression and nitric oxide production. Moreover, VD3 and HX630 inhibited LPS-induced activation of extracellular signal-regulated kinase (ERK) and nuclear translocation of nuclear factor κB (NF-κB). PD98059, an inhibitor of ERK kinase, attenuated LPS-induced nuclear translocation of NF-κB and induction of mRNAs for iNOS, IL-1β and IL-6. These results indicate that VD3 can inhibit production of several pro-inflammatory molecules from microglia, and that suppression of ERK activation is at least in part involved in the anti-inflammatory effect of VD3.

  8. Van der Waals epitaxial growth of two-dimensional single-crystalline GaSe domains on graphene

    DOE PAGES

    Li, Xufan; Basile, Leonardo; Huang, Bing; ...

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigationsmore » of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.« less

  9. Van der Waals epitaxial growth of two-dimensional single-crystalline GaSe domains on graphene

    SciTech Connect

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V.; Puretzky, Alexander A.; Lin, Ming -Wei; Chi, Miaofang; Idrobo Tapia, Juan Carlos; Rouleau, Christopher M.; Sumpter, Bobby G.; Yoon, Mina; Geohegan, David B.; Xiao, Kai

    2015-07-22

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially-structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to stamping, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here, we explore the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. Guided by the wrinkles on graphene, GaSe nuclei form that share a predominant lattice orientation. Due to vdW epitaxial growth many nuclei grow as perfectly aligned crystals and coalesce to form large (tens of microns), single-crystal flakes. Through theoretical investigations of interlayer energetics, and measurements of preferred orientations by atomic-resolution STEM and electron diffraction, a 10.9 interlayer rotation of the GaSe lattice with respect to the underlying graphene is found to be the most energetically preferred vdW heterostructure with the largest binding energy and the longest-range ordering. These GaSe/Gr vdW heterostructures exhibit an enhanced Raman E21g band of monolayer GaSe along with highly-quenched photoluminescence due to strong charge transfer. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.

  10. ESSDERC (European Solid State Device Research Conference) 17th Held in Bologna, Italy on 14-17 September 1987

    DTIC Science & Technology

    1987-09-17

    are stressed by imposing a of the continuous increase of the applied volta - constant current at the drain and at the sub- ges (Vd and Vsub)’ In order...the current across the J a the mean current N scrom the device section, device. VD the voltae applied between anode and cathode, For two opposite...threshold voltae control. Although VTb is Front gate threshold voltage versus film thickness (V b-0 V). Same technological parameters as in positive

  11. Seasonal variations in vitamin D status in indoor and outdoor female athletes

    PubMed Central

    MARUYAMA-NAGAO, ASAKO; SAKURABA, KEISHOKU; SUZUKI, YOSHIO

    2016-01-01

    Vitamin D (VD) insufficiency is a concern, particularly among young females. The VD status shows seasonal variations, since it correlates with duration of sunlight exposure. VD insufficiency in indoor athletes is therefore suggested in winter. The aim of the present study was to determine seasonal variations in VD and bone status among indoor and outdoor female athletes. The prospective study was conducted in participants aged 20–22 years old. The participants comprised of 15 indoor and 15 outdoor athletes. The biochemical markers and bone parameters were measured in March, June, September and December. The serum 25-hydroxyvitamin D (25-OH-VD) concentration showed a seasonal oscillation, with a nadir in March (indoor, 19±4.0 ng/ml; outdoor, 32±2.7 ng/ml) and a peak in September (indoor, 32±6.6 ng/ml; outdoor, 39±5.7 ng/ml). The amplitude of oscillation was greater in the indoor compared to the outdoor athletes. Seasonal variations in serum calcium exhibited a similar pattern, while the parathyroid hormone showed an inverse pattern to serum 25-OH-VD. The nadir in bone mass, measured as speed of sound, occurred in June after peaking in December among the indoor and outdoor athletes. The pattern followed 3 months after the changes in 25-OH-VD. Indoor sports athletes are more susceptible to VD insufficiency compared to outdoor sports athletes. Insufficiency is most likely to arise in winter, and could affect bone mineralization observed 3 months after. PMID:27347414

  12. Optical Coherence Tomography Angiography Vessel Density in Healthy, Glaucoma Suspect, and Glaucoma Eyes

    PubMed Central

    Yarmohammadi, Adeleh; Zangwill, Linda M.; Diniz-Filho, Alberto; Suh, Min Hee; Manalastas, Patricia Isabel; Fatehee, Naeem; Yousefi, Siamak; Belghith, Akram; Saunders, Luke J.; Medeiros, Felipe A.; Huang, David; Weinreb, Robert N.

    2016-01-01

    Purpose The purpose of this study was to compare retinal nerve fiber layer (RNFL) thickness and optical coherence tomography angiography (OCT-A) retinal vasculature measurements in healthy, glaucoma suspect, and glaucoma patients. Methods Two hundred sixty-one eyes of 164 healthy, glaucoma suspect, and open-angle glaucoma (OAG) participants from the Diagnostic Innovations in Glaucoma Study with good quality OCT-A images were included. Retinal vasculature information was summarized as a vessel density map and as vessel density (%), which is the proportion of flowing vessel area over the total area evaluated. Two vessel density measurements extracted from the RNFL were analyzed: (1) circumpapillary vessel density (cpVD) measured in a 750-μm-wide elliptical annulus around the disc and (2) whole image vessel density (wiVD) measured over the entire image. Areas under the receiver operating characteristic curves (AUROC) were used to evaluate diagnostic accuracy. Results Age-adjusted mean vessel density was significantly lower in OAG eyes compared with glaucoma suspects and healthy eyes. (cpVD: 55.1 ± 7%, 60.3 ± 5%, and 64.2 ± 3%, respectively; P < 0.001; and wiVD: 46.2 ± 6%, 51.3 ± 5%, and 56.6 ± 3%, respectively; P < 0.001). For differentiating between glaucoma and healthy eyes, the age-adjusted AUROC was highest for wiVD (0.94), followed by RNFL thickness (0.92) and cpVD (0.83). The AUROCs for differentiating between healthy and glaucoma suspect eyes were highest for wiVD (0.70), followed by cpVD (0.65) and RNFL thickness (0.65). Conclusions Optical coherence tomography angiography vessel density had similar diagnostic accuracy to RNFL thickness measurements for differentiating between healthy and glaucoma eyes. These results suggest that OCT-A measurements reflect damage to tissues relevant to the pathophysiology of OAG. PMID:27409505

  13. Dynamical screening of van der Waals interactions in nanostructured solids: Sublimation of fullerenes

    SciTech Connect

    Tao, Jianmin; Yang, Jing; Rappe, Andrew M.

    2015-04-28

    Sublimation energy is one of the most important properties of molecular crystals, but it is difficult to study, because the attractive long-range van der Waals (vdW) interaction plays an important role. Here, we apply efficient semilocal density functional theory (DFT), corrected with the dynamically screened vdW interaction (DFT + vdW), the Rutgers-Chalmers nonlocal vdW-DF, and the pairwise-based dispersion-corrected DFT-D2 developed by Grimme and co-workers, to study the sublimation of fullerenes. We find that the short-range part, which accounts for the interaction due to the orbital overlap between fullerenes, is negligibly small. Our calculation shows that there exists a strong screening effect on the vdW interaction arising from the valence electrons of fullerenes. On the other hand, higher-order contributions can be as important as the leading-order term. The reasons are that (i) the surface of fullerene molecules is metallic and thus highly polarizable, (ii) the band gap of fullerene solids is small (less than 2 eV), and (iii) fullerene molecules in the solid phase are so densely packed, yielding the high valence electron density and small equilibrium intermolecular distances (the first nearest neighbor distance is only about 10 Å for C{sub 60}). However, these two effects make opposite contributions, leading to significant error cancellation between these two contributions. We demonstrate that, by considering higher-order contributions and the dynamical screening, the DFT + vdW method can yield sublimation energies of fullerenes in good agreement with reference values, followed by vdW-DF and DFT-D2. The insights from this study are important for a better understanding of the long-range nature of vdW interactions in nanostructured solids.

  14. Research of Extension of the Life Cycle of Helicopter Rotor Blade in Hungary

    DTIC Science & Technology

    2003-02-01

    Radiography (DXR), and (iii) Vibration Diagnostics (VD) with Statistical Energy Analysis (SEA) were semi- simultaneously applied [1]. The used three...2.2. Vibration Diagnostics (VD)) Parallel to the NDT measurements the Statistical Energy Analysis (SEA) as a vibration diagnostical tool were...noises were analysed with a dual-channel real time frequency analyser (BK2035). In addition to the Statistical Energy Analysis measurement a small

  15. Interaction of boron with graphite: A van der Waals density functional study

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Wang, Chen; Liang, Tongxiang; Lai, Wensheng

    2016-08-01

    Boron doping has been widely investigated to improve oxidation resistance of graphite. In this work the interaction of boron with graphite is investigated by a van der Waals density-functional approach (vdW-DF). The traditional density-functional theory (DFT) is well accounted for the binding in boron-substituted graphite. However, to investigate the boron atom on graphite surface and the interstitial impurities require use of a description of graphite interlayer binding. Traditional DFT cannot describe the vdW physics, for instance, GGA calculations show no relevant binding between graphite sheets. LDA shows some binding, but they fail to provide an accurate account of vdW forces. In this paper, we compare the calculation results of graphite lattice constant and cohesive energy by several functionals, it shows that vdW-DF such as two optimized functionals optB88-vdW and optB86b-vdW give much improved results than traditional DFT. The vdW-DF approach is then applied to study the interaction of boron with graphite. Boron adsorption, substitution, and intercalation are discussed in terms of structural parameters and electronic structures. When adsorbing on graphite surface, boron behaves as π electron acceptor. The π electron approaches boron atom because of more electropositive of boron than carbon. For substitution situation, the hole introduced by boron mainly concentrates on boron and the nearest three carbon atoms. The B-doped graphite system with the hole has less ability to offer electrons to oxygen, ultimately resulted in the inhibition of carbon oxidation. For interstitial doping, vdW-DFs show more accurate formation energy than LDA. PBE functional cannot describe the interstitial boron in graphite reasonably because of the ignoring binding of graphite sheets. The investigation of electron structures of boron doped graphite will play an important role in understanding the oxidation mechanism in further study.

  16. Combination of lenalidomide with vitamin D3 induces apoptosis in mantle cell lymphoma via demethylation of BIK

    PubMed Central

    Brosseau, C; Dousset, C; Touzeau, C; Maïga, S; Moreau, P; Amiot, M; Le Gouill, S; Pellat-Deceunynck, C

    2014-01-01

    Mantle cell lymphoma (MCL) is a currently incurable B-cell malignancy. Lenalidomide (Len) has been demonstrated to be one of the most efficient new treatment options. Because Len and 1α,25-dihydroxyvitamin (VD3) synergize to kill breast cancer cells, we investigated whether VD3 could increase the ability of Len to induce MCL cell death. While MCL cells were weakly sensitive to Len (1 μM), the addition of VD3 at physiological dose (100 nM) strongly increased cell death, accompanied by slowdown in cell cycle progression in MCL cell lines (n=4 out of 6) and primary samples (n=5 out of 7). The Len/VD3 treatment markedly increased the expression of the BH3-only BCL2-interacting killer (Bik) without affecting the expression of other Bcl-2 molecules. Immunoprecipitation assays demonstrated that Bik was free from anti-apoptotic partners, Bcl-2 and Bcl-xL, in treated cells. Moreover, silencing of BIK prevented apoptosis induced by Len/VD3, confirming the direct involvement of Bik in cell death. Bik accumulation induced by Len/VD3 was related to an increase in BIK mRNA levels, which resulted from a demethylation of BIK CpG islands. The sensitivity of MCL cells to Len/VD3 was similar to the response to 5-azacytidine, which also induced demethylation of BIK CpG islands. These preclinical data provide the rationale to investigate the role of VD3 in vivo in the response to Len. PMID:25165875

  17. Radiation-epidemiological Study of Cerebrovascular Diseases in the Cohort of Russian Recovery Operation Workers of the Chernobyl Accident.

    PubMed

    Kashcheev, V V; Chekin, S Yu; Maksioutov, M A; Tumanov, K A; Menyaylo, A N; Kochergina, E V; Kashcheeva, P V; Gorsky, A I; Shchukina, N V; Karpenko, S V; Ivanov, V K

    2016-08-01

    The paper presents an analysis of the incidence of cerebrovascular diseases (CeVD) in the cohort of Russian workers involved in recovery tasks after the Chernobyl accident. The studied cohort consists of 53,772 recovery operation workers (liquidators) who arrived in the zone of the Chernobyl accident within the first year after this accident (26 April 1986-26 April 1987). The mean external whole body dose in the cohort was 0.161 Gy, while individual doses varied from 0.0001 Gy to 1.42 Gy. During the follow-up period 1986-2012, a total of 23,264 cases of CeVD were diagnosed as a result of annual health examinations. A Poisson regression model was applied for estimation of radiation risks and for an assessment of other risk factors of CeVD. The following factors were considered as risk factors for CeVD: the dose, duration of the liquidators' work in the Chernobyl zone, and the concomitant diseases (hypertension, ischemic heart disease, atherosclerosis, and diabetes). The baseline incidence of CeVD is statistically significantly (p < 0.001) associated with all studied concomitant diseases. The incidence of CeVD has revealed a statistically significant dose response with the lack of a latent period and with the average ERR/Gy = 0.45, 95% CI: (0.28, 0.62), p < 0.001. Radiation risks of CeVD statistically significantly (p = 0.03) varied with the duration of liquidators' stay in the Chernobyl zone; for those who stayed in the Chernobyl zone less than 6 wk, ERR/Gy = 0.64, 95% CI = (0.38; 0.93), p < 0.001. Among studied concomitant diseases, diabetes mellitus statistically significantly (p = 0.002) increases the radiation risk of CeVD: for liquidators with diagnosed diabetes, ERR/Gy = 1.29.

  18. The Future of INTELSAT in a Competitive Environment

    DTIC Science & Technology

    1988-12-01

    prices, however, raises three issues: * INTELSAT’s ability to price competitively without requiring modification of Article V(d) in the INTELSAT agreement...that forbids price discrimination. While some leeway exists to pricing flexibly under Article V(d), it could pose a barrier to the degree of flexible...successfully consulted under Article XIV(d) of the INTELSAT Agreement as posing no "significant" economic harm to INTELSAT. Consultation procedures for six

  19. Parathyroidectomy: is vitamin D a player for a good outcome?

    PubMed

    M, Carsote; Dn, Paduraru; Ae, Nica; A, Valea

    2016-01-01

    Background: The field of parathyroidectomy (PTx) is complex and brings together many specialists. Even if the surgical approaches changed from classical to minimally invasive PTx, a good outcome is correlated with an adequate localization before and during PTx, while blood assays, such as parathormone (PTH) or 25-hydroxyvitamin D, become useful additional markers. Aim. Specific aspects related to parathyroidectomy and vitamins D (VD) were introduced. Material and Method. The article represents a PubMed-based narrative review. Results. The growing evidence regarding the high prevalence of hypovitaminosis D and early detection of primary hyperparathyroidism (HPT) requires a particular attention to the association of these two disorders, which may be incidental, but some common pathogenic links are displayed. Low VD stimulates PTH production as a secondary or even tertiary type of HPT diagnosis. VD deficiency is associated with larger parathyroid adenomas and higher levels of PTH before and after surgery for primary HPT. Asymptomatically and normocalcemic forms of primary HPT, which are not immediately referred to PTx, require a normalization of the VD levels. VD supplements are safe under some serum calcium cutoffs and offer a better outcome after PTx. However, primary HPT is cured by surgery and, if the indication is well established, this should not be delayed too long to replace VD. Up to half of PTx cases may experience increased PTH levels after surgery, but most of these are transitory if rapid VD correction is done and only a few remaining cases will eventually develop persistent / recurrent primary HPT. Conclusion. A close following of 25-hydroxivitamin D represents one of the keys for a good outcome in the field of parathyroid surgery. Abbreviations: HPT = hyperparathyroidism, MEN = Multiple Endocrine Neoplasia Syndrome, PTx = parathyroidectomy, PTH = parathormone, VD = Vitamin D.

  20. Keratinocyte G2/M growth arrest by 1,25-dihydroxyvitamin D3 is caused by Cdc2 phosphorylation through Wee1 and Myt1 regulation.

    PubMed

    Dai, Xiuju; Yamasaki, Kenshi; Yang, Lujun; Sayama, Koji; Shirakata, Yuji; Tokumara, Sho; Yahata, Yoko; Tohyama, Mikiko; Hashimoto, Koji

    2004-06-01

    1,25-dihydroxyvitamin D3 (1,25[OH]2VD3) has an antiproliferative effect on keratinocyte growth, and its derivatives are used for the treatment of psoriasis. It was reported previously that 1,25[OH]2VD3 induced cell cycle arrest not only at the G0/G1 phase but also at the G2/M phase. However, the mechanism of 1,25[OH]2VD3-induced G2/M phase arrest in keratinocytes has not been fully understood. The addition of 10(-8) to 10(-6) M 1,25[OH]2VD3 to cultured normal human keratinocytes enhanced the expression of Myt1 mRNA preceding Wee1 mRNA; 10(-6) M 1,25[OH]2VD3 unregulated Myt1 mRNA from 6 h to 24 h and Wee1 mRNA from 12 to 48 h. Interestingly, the levels of phosphorylated Cdc2 were increased between 6 h and 48 h after 1,25[OH]2VD3 treatment, although the expression levels of Cdc2 mRNA and its protein production were reduced. 1,25[OH]2VD3 also decreased the expression of cyclin B1, which forms a complex with Cdc2. These data indicated that the increase of Myt1 and Wee1 induced the phosphorylation of Cdc2 leading to G2/M arrest. In conclusion, the induction of Cdc2 phosphorylation due to the increase of Wee1 and Myt1 as well as the reduction of Cdc2 and cyclin B1 are involved in 1,25[OH]2VD3-induced G2/M arrest of keratinocytes.

  1. [Surgical treatment of recurrence of the varicose veins in the lower extremities].

    PubMed

    Henyk, S M; Oleksyn, V I; Henyk, I S

    2000-11-01

    The results of treatment in 1080 patients with the lower extremities varicose disease (VD) were analyzed. For the subcutaneous veins recurrent varicose (SVV) there were operated 11.2% patients, including, once--76.1%, twice--17.4%, three times--6.5%. In all 146 the operations were performed. Sclerosing therapy of SVV was applied in 21 patients. Basic mistake during performance of the first operative intervention for the VD was insufficient evaluation of character of the blood outflow disorder.

  2. State-dependent variability of dynamic functional connectivity between frontoparietal and default networks relates to cognitive flexibility.

    PubMed

    Douw, Linda; Wakeman, Daniel G; Tanaka, Naoaki; Liu, Hesheng; Stufflebeam, Steven M

    2016-12-17

    The brain is a dynamic, flexible network that continuously reconfigures. However, the neural underpinnings of how state-dependent variability of dynamic functional connectivity (vdFC) relates to cognitive flexibility are unclear. We therefore investigated flexible functional connectivity during resting-state and task-state functional magnetic resonance imaging (rs-fMRI and t-fMRI, resp.) and performed separate, out-of-scanner neuropsychological testing. We hypothesize that state-dependent vdFC between the frontoparietal network (FPN) and the default mode network (DMN) relates to cognitive flexibility. Seventeen healthy subjects performed the Stroop color word test and underwent t-fMRI (Stroop computerized version) and rs-fMRI. Time series were extracted from a cortical atlas, and a sliding window approach was used to obtain a number of correlation matrices per subject. vdFC was defined as the standard deviation of connectivity strengths over these windows. Higher task-state FPN-DMN vdFC was associated with greater out-of-scanner cognitive flexibility, while the opposite relationship was present for resting-state FPN-DMN vdFC. Moreover, greater contrast between task-state and resting-state vdFC related to better cognitive performance. In conclusion, our results suggest that not only the dynamics of connectivity between these networks is seminal for optimal functioning, but also that the contrast between dynamics across states reflects cognitive performance.

  3. Effect of the van der Waals interaction on the electron energy-loss near edge structure theoretical calculation.

    PubMed

    Katsukura, Hirotaka; Miyata, Tomohiro; Tomita, Kota; Mizoguchi, Teruyasu

    2016-07-21

    The effect of the van der Waals (vdW) interaction on the simulation of the electron energy-loss near edge structure (ELNES) by a first-principles band-structure calculation is reported. The effect of the vdW interaction is considered by the Tkatchenko-Scheffler scheme, and the change of the spectrum profile and the energy shift are discussed. We perform calculations on systems in the solid, liquid and gaseous states. The transition energy shifts to lower energy by approximately 0.1eV in the condensed (solid and liquid) systems by introducing the vdW effect into the calculation, whereas the energy shift in the gaseous models is negligible owing to the long intermolecular distance. We reveal that the vdW interaction exhibits a larger effect on the excited state than the ground state owing to the presence of an excited electron in the unoccupied band. Moreover, the vdW effect is found to depend on the local electron density and the molecular coordination. In addition, this study suggests that the detection of the vdW interactions exhibited within materials is possible by a very stable and high resolution observation.

  4. A van der Waals DFT Approach to Modeling Water

    NASA Astrophysics Data System (ADS)

    Kolb, Brian; Thonhauser, Timo

    2010-03-01

    We present density functional theory calculations for small water clusters and bulk water including van der Waals interactions via the non-local functional vdW-DF [1]. Historically, standard functionals such as LDA or GGA have been unable to accurately predict vibrational frequencies of small water clusters or the freezing point of bulk water, which has been partly attributed to the lack of van der Waals interactions [2]. We have implemented vdW-DF in the PWscf package, using an efficient convolution approach [3]. Our results for the vibrational frequencies of small water clusters show that vdW-DF gives a significant improvement compared to LDA or GGA. While the discrepancy between experiment and LDA/GGA is as much as 28% for certain modes, vdW-DF reduces this error to only about 6%. We also present results for the vibrational spectrum and Raman spectrum of periodic ice, again showing the advantages of vdW-DF. In addition, we show preliminary results for bulk water from our vdW-DF MD simulations.[4pt] [1] Thonhauser et al., Phys. Rev. B 76, 125112 (2007).[2] H. Sit and N. Marzari, J. Chem. Phys. 122, 204510 (2005). [3] G. Roman-Perez and J. Soler, Phys. Rev. Lett. 103, 096102 (2009).

  5. Recent developments and future directions in the growth of nanostructures by van der Waals epitaxy

    NASA Astrophysics Data System (ADS)

    Bakti Utama, Muhammad Iqbal; Zhang, Qing; Zhang, Jun; Yuan, Yanwen; Belarre, Francisco J.; Arbiol, Jordi; Xiong, Qihua

    2013-04-01

    Here we review the characteristics of ``van der Waals epitaxy'' (vdWE) as an alternative epitaxy mechanism that has been demonstrated as a viable method for circumventing the lattice matching requirements for epitaxial growth. Particular focus is given on the application of vdWE for nonplanar nanostructures. We highlight our works on the vdWE growth of nanowire arrays, tripods, and tetrapods from various semiconductors (ZnO, ZnTe, CdS, CdSe, CdSxSe1-x, CdTe, and PbS) on muscovite mica substrates, irrespective of the ensuing lattice mismatch. We then address the controllability of the synthesis and the growth mechanism of ZnO nanowires from catalyst-free vdWE in vapor transport growth. As exemplified herein with optical characterizations of ZnO and CdSe nanowires, we show that samples from vdWE may possess properties that are as excellent as those from conventional epitaxy. With our works, we aim to advocate vdWE as a prospective universal growth strategy for nonplanar epitaxial nanostructures.

  6. New Vehicle Detection Method with Aspect Ratio Estimation for Hypothesized Windows.

    PubMed

    Kim, Jisu; Baek, Jeonghyun; Park, Yongseo; Kim, Euntai

    2015-12-09

    All kinds of vehicles have different ratios of width to height, which are called the aspect ratios. Most previous works, however, use a fixed aspect ratio for vehicle detection (VD). The use of a fixed vehicle aspect ratio for VD degrades the performance. Thus, the estimation of a vehicle aspect ratio is an important part of robust VD. Taking this idea into account, a new on-road vehicle detection system is proposed in this paper. The proposed method estimates the aspect ratio of the hypothesized windows to improve the VD performance. Our proposed method uses an Aggregate Channel Feature (ACF) and a support vector machine (SVM) to verify the hypothesized windows with the estimated aspect ratio. The contribution of this paper is threefold. First, the estimation of vehicle aspect ratio is inserted between the HG (hypothesis generation) and the HV (hypothesis verification). Second, a simple HG method named a signed horizontal edge map is proposed to speed up VD. Third, a new measure is proposed to represent the overlapping ratio between the ground truth and the detection results. This new measure is used to show that the proposed method is better than previous works in terms of robust VD. Finally, the Pittsburgh dataset is used to verify the performance of the proposed method.

  7. Porcine Epidemic Diarrhea Virus Infection Induced the Unbalance of Gut Microbiota in Piglets.

    PubMed

    Liu, Shuyun; Zhao, Lele; Zhai, Zhengxiao; Zhao, Wenjing; Ding, Jinmei; Dai, Ronghua; Sun, Tao; Meng, He

    2015-12-01

    Porcine epidemic diarrhea (PED) is a devastating disease in livestock industry. Most of the previous studies related to the PED were focused on the pathology and etiology of porcine epidemic diarrhea virus (PEDV). A little was known regarding the status of gut microbiota after piglets infected by PEDV. In this study, aided by metagenome sequencing technology, gut microbiota profiles in feces of viral diarrhea (VD) and viral control (VC) piglets were investigated. The results showed that the abundance of four dominant phyla (Fusobacteria, Actinobacteria, Verrucomicrobia, and Proteobacteria) in feces was affected greatly by porcine epidemic diarrhea. Especially, the abundance of Fusobacteria was higher in VD piglets (36%) than in VC piglets (5%). On the contrary, the Verrucomicrobia was detected in lower distribution proportion in VD piglets (around 0%) than in VC piglets (20%). Furthermore, 25 genera were significantly different between VC and VD piglets at the genus level. Among the 25 genera, Leptotrichia belonging to Fusobacteria was remarkably lower in VC piglets than in VD piglets. Akkermansia belonging to Verrucomicrobia was higher in VC piglets than in VD piglets. Our findings implicated that the gut microbiota associated with PED significantly provided an insight into the pathology and physiology of PED.

  8. New Vehicle Detection Method with Aspect Ratio Estimation for Hypothesized Windows

    PubMed Central

    Kim, Jisu; Baek, Jeonghyun; Park, Yongseo; Kim, Euntai

    2015-01-01

    All kinds of vehicles have different ratios of width to height, which are called the aspect ratios. Most previous works, however, use a fixed aspect ratio for vehicle detection (VD). The use of a fixed vehicle aspect ratio for VD degrades the performance. Thus, the estimation of a vehicle aspect ratio is an important part of robust VD. Taking this idea into account, a new on-road vehicle detection system is proposed in this paper. The proposed method estimates the aspect ratio of the hypothesized windows to improve the VD performance. Our proposed method uses an Aggregate Channel Feature (ACF) and a support vector machine (SVM) to verify the hypothesized windows with the estimated aspect ratio. The contribution of this paper is threefold. First, the estimation of vehicle aspect ratio is inserted between the HG (hypothesis generation) and the HV (hypothesis verification). Second, a simple HG method named a signed horizontal edge map is proposed to speed up VD. Third, a new measure is proposed to represent the overlapping ratio between the ground truth and the detection results. This new measure is used to show that the proposed method is better than previous works in terms of robust VD. Finally, the Pittsburgh dataset is used to verify the performance of the proposed method. PMID:26690177

  9. Molecular cloning and expression of key gene encoding hypothetical DNA polymerase from B. mori parvo-like virus.

    PubMed

    Zhang, Junhong; Li, Guohui; Chen, Huiqing; Li, Xiaogang; Lv, Meng; Chen, Keping; Yao, Qin

    2010-10-01

    BmPLV-Z is the abbreviation for Bombyx mori parvo-like virus (China isolate). This is a novel virus with two single-stranded linear DNA molecules, viz., VD1 (6543 bp) and VD2 (6022 bp), which are encapsidated respectively into separate virions. Analysis of the deduced amino acid sequence of VD1-ORF4 indicated the existence of a putative DNA-polymerase with exonuclease activity, possibly involved in the replication of BmPLV-Z. In the present study, a recombinant baculovirus was constructed to express the full length of the protein encoded by the VD1-ORF4 gene (3318 bp). In addition, a 2163-bp fragment amplified from the very same gene was cloned into prokaryotic expression vector pET-30a and expressed in E.coli Rosetta 2 (DE3) pLysS. The expressed fusion protein was employed to immunize New Zealand white rabbits for the production of an antiserum, afterwards used for examining the expression of the protein encoded by VD1-ORF4 gene in Sf-9 cells infected with recombinant baculovirus. Western blot analysis of extracts from thus cells infected revealed a specific band of about 120 kDa, thereby indicating that the full length protein encoded by the VD1-ORF4 gene had been successfully and stably expressed in Sf-9 cells.

  10. Clinical utility of copper, ceruloplasmin, and metallothionein plasma determinations in human neurodegenerative patients and their first-degree relatives.

    PubMed

    Arnal, Nathalie; Cristalli, Diana Olga; de Alaniz, María J T; Marra, Carlos Alberto

    2010-03-10

    The concentration of plasma copper, ceruloplasmin (CRP), non-ceruloplasmin-bound Cu (NCBC), and metallothioneins (MTs) were studied as putative biomarkers for neurodegenerative diseases in patients and in their first-degree relatives. We found increased levels of Cu in the plasma of Alzheimer's disease (AD), Parkinson's disease (PD), and vascular dementia (VD) patients, and the increase observed in VD group was linked to the evolution of the disease. CRP was also elevated in response to the inflammatory component of the diseases, however, a correlation with illness progression was only observed in VD patients. The level of MTs is proportional to the evolution of VD. The Cu/CRP and Cu/MTs ratios are both indicative of disease progression for AD patients but not for those with PD or VD. Moreover, there is a correlation between the NCBC levels and the cognitive impairment estimated through the Mini-mental State Examination (MMSE) scale. This dependence is linear for AD and PD patients and non-linear for the VD ones. The relative values of NCBC showed dependence on the disease duration, especially for AD. Copper measurement and the Cu/CRP ratio may be predictive markers of risk for the first-degree relatives of AD patients. We believe that these results are valuable as a reliable clinical tool.

  11. A voluntary deductible in health insurance: the more years you opt for it, the lower your premium?

    PubMed

    van Winssen, K P M; van Kleef, R C; van de Ven, W P M M

    2017-03-01

    Adverse selection regarding a voluntary deductible (VD) in health insurance implies that insured only opt for a VD if they expect no (or few) healthcare expenses. This paper investigates two potential strategies to reduce adverse selection: (1) differentiating the premium to the duration of the contract for which the VD holds (ex-ante approach) and (2) differentiating the premium to the number of years for which insured have opted for a VD (ex-post approach). It can be hypothesized that premiums will decrease with the duration of the contract or the number of years for which insured have opted for a VD, providing an incentive to insured to opt for a deductible also in (incidental) years they expect relatively high expenses. To test this hypothesis, we examine which premium patterns would occur under these strategies using data on healthcare expenses and risk characteristics of over 750,000 insured from 6 years. Our results show that, under the assumptions made, only without risk equalization the premiums could decrease with the duration of the contract or the number of years for which insured have opted for a VD. With (sophisticated) risk equalization, decreasing premiums seem unfeasible, both under the ex-ante and ex-post approach. Given these findings, we are sceptical about the feasibility of these strategies to counteract adverse selection.

  12. Non-additivity of molecule-surface van der Waals potentials from force measurements

    PubMed Central

    Wagner, Christian; Fournier, Norman; Ruiz, Victor G.; Li, Chen; Müllen, Klaus; Rohlfing, Michael; Tkatchenko, Alexandre; Temirov, Ruslan; Tautz, F. Stefan

    2014-01-01

    Van der Waals (vdW) forces act ubiquitously in condensed matter. Despite being weak on an atomic level, they substantially influence molecular and biological systems due to their long range and system-size scaling. The difficulty to isolate and measure vdW forces on a single-molecule level causes our present understanding to be strongly theory based. Here we show measurements of the attractive potential between differently sized organic molecules and a metal surface using an atomic force microscope. Our choice of molecules and the large molecule-surface separation cause this attraction to be purely of vdW type. The experiment allows testing the asymptotic vdW force law and its validity range. We find a superlinear growth of the vdW attraction with molecular size, originating from the increased deconfinement of electrons in the molecules. Because such non-additive vdW contributions are not accounted for in most first-principles or empirical calculations, we suggest further development in that direction. PMID:25424490

  13. Effects of van der Waals Interactions in the Adsorption of Isooctane and Ethanol on Fe(100) Surfaces.

    PubMed

    Bedolla, Pedro O; Feldbauer, Gregor; Wolloch, Michael; Eder, Stefan J; Dörr, Nicole; Mohn, Peter; Redinger, Josef; Vernes, András

    2014-08-07

    van der Waals (vdW) forces play a fundamental role in the structure and behavior of diverse systems. Because of development of functionals that include nonlocal correlation, it is possible to study the effects of vdW interactions in systems of industrial and tribological interest. Here we simulated within the framework of density functional theory (DFT) the adsorption of isooctane (2,2,4-trimethylpentane) and ethanol on an Fe(100) surface, employing various exchange-correlation functionals to take vdW forces into account. In particular, this paper discusses the effect of vdW forces on the magnitude of adsorption energies, equilibrium geometries, and their role in the binding mechanism. According to our calculations, vdW interactions increase the adsorption energies and reduce the equilibrium distances. Nevertheless, they do not influence the spatial configuration of the adsorbed molecules. Their effect on the electronic density is a nonisotropic, delocalized accumulation of charge between the molecule and the slab. In conclusion, vdW forces are essential for the adsorption of isooctane and ethanol on a bcc Fe(100) surface.

  14. Vitamin D3 inhibits micro RNA-17-92 to promote specific immunotherapy in allergic rhinitis.

    PubMed

    Yu, Zhi-Jian; Zeng, Lu; Luo, Xiang-Qian; Geng, Xiao-Rui; Xu, Rui; Chen, Kun; Yang, Gui; Luo, Xi; Liu, Zhi-Qiang; Liu, Zhi-Gang; Liu, Da-Bo; Yang, Ping-Chang; Li, Hua-Bin

    2017-04-03

    It is recognized that T helper 2 (Th2) polarization plays a critical role in a large number of immune disorders. Yet, the remedies for reconciling the established Th2 polarization are still limited currently. Published data indicate that micro RNA-17-92 cluster is associated with the skewed immune response; 25 vitamin D3 (VD3) can regulate multiple bioactivities in the body. This study tests a hypothesis that VD3 facilitates the effect of specific immunotherapy (SIT) on Th2 response. We observed that treatment with either SIT or VD3 alleviated AR symptoms as well as reduced serum levels of specific IgE and T helper (Th) 2 cytokines, suppressed miR-19a (one of the members of the miR-17-92 cluster) and increased IL-10 in peripheral B cells, which was further improved in those AR patients treated with both SIT and VD3. The expression of miR-19a and IL-10 was significantly negatively correlated with each other in peripheral B cells of AR patients. Metabolites of VD3 formed a complex with retinoid acid receptor to repress the expression of miR-19a in B cells. We conclude that administration with VD3 promotes the effect of SIT on suppression of AR via repressing the expression of miR-19a in peripheral B cells.

  15. Impact of prior treatment on patients with relapsed multiple myeloma treated with carfilzomib and dexamethasone vs bortezomib and dexamethasone in the phase 3 ENDEAVOR study

    PubMed Central

    Moreau, P; Joshua, D; Chng, W-J; Palumbo, A; Goldschmidt, H; Hájek, R; Facon, T; Ludwig, H; Pour, L; Niesvizky, R; Oriol, A; Rosiñol, L; Suvorov, A; Gaidano, G; Pika, T; Weisel, K; Goranova-Marinova, V; Gillenwater, H H; Mohamed, N; Aggarwal, S; Feng, S; Dimopoulos, M A

    2017-01-01

    The randomized phase 3 ENDEAVOR study (N=929) compared carfilzomib and dexamethasone (Kd) with bortezomib and dexamethasone (Vd) in relapsed multiple myeloma (RMM). We performed a subgroup analysis from ENDEAVOR in patients categorized by number of prior lines of therapy or by prior treatment. Median progression-free survival (PFS) for patients with one prior line was 22.2 months for Kd vs 10.1 months for Vd, and median PFS for patients with ⩾2 prior lines was 14.9 months for Kd vs 8.4 months for Vd. For patients with prior bortezomib exposure, the median PFS was 15.6 months for Kd vs 8.1 months for Vd, and for patients with prior lenalidomide exposure the median PFS was 12.9 months for Kd vs 7.3 months for Vd. Overall response rates (Kd vs Vd) were 81.9 vs 65.5% (one prior line), 72.0 vs 59.7% (⩾2 prior lines), 71.2 vs 60.3% (prior bortezomib) and 70.1 vs 59.3% (prior lenalidomide). The safety profile in the prior lines subgroups was qualitatively similar to that in the broader ENDEAVOR population. In RMM, outcomes are improved when receiving treatment with carfilzomib compared with bortezomib, regardless of the number of prior therapy lines or prior exposure to bortezomib or lenalidomide. PMID:27491641

  16. A standardised terminology of the embryonic envelopes and associated developmental stages of tapeworms (Platyhelminthes: Cestoda).

    PubMed

    Conn, David Bruce; Swiderski, Zdzisław

    2008-03-01

    Over the past 40 years, much has been published on the ultrastructure and cellular development of embryonic structures in a wide range of cestodes. However, the literature contains many discrepancies in both terminology and interpretations because of the facts that these organisms are phylogenetically diverse within their respective orders and families, the habitats that affect embryonic envelope structure are diverse, and the work has been done in various laboratories around the world. This review and synthesis was initiated by a working group of biologists from around the world convened at the Fifth International Workshop on Cestode Systematics and Phylogeny in Ceské Budejovice, at the Institute of Parasitology of the Biology Centre, Academy of Sciences of the Czech Republic. It brings together the data from published work and establishes a uniform terminology and interpretation based on the data as they are presented. A consensus was reached for standardised definitions of the oncosphere, hexacanth, coracidium, embryonic envelopes, outer envelope, inner envelope, embryophore, vitelline capsule, shell, and outer coat. All of these are defined as components of the embryo or its vitellocyte-derived or uterine-derived coatings.

  17. Phosphorylation of a Herpes Simplex Virus 1 dUTPase by a Viral Protein Kinase, Us3, Dictates Viral Pathogenicity in the Central Nervous System but Not at the Periphery

    PubMed Central

    Kato, Akihisa; Shindo, Keiko; Maruzuru, Yuhei

    2014-01-01

    ABSTRACT Herpes simplex virus 1 (HSV-1) encodes Us3 protein kinase, which is critical for viral pathogenicity in both mouse peripheral sites (e.g., eyes and vaginas) and in the central nervous systems (CNS) of mice after intracranial and peripheral inoculations, respectively. Whereas some Us3 substrates involved in Us3 pathogenicity in peripheral sites have been reported, those involved in Us3 pathogenicity in the CNS remain to be identified. We recently reported that Us3 phosphorylated HSV-1 dUTPase (vdUTPase) at serine 187 (Ser-187) in infected cells, and this phosphorylation promoted viral replication by regulating optimal enzymatic activity of vdUTPase. In the present study, we show that the replacement of vdUTPase Ser-187 by alanine (S187A) significantly reduced viral replication and virulence in the CNS of mice following intracranial inoculation and that the phosphomimetic substitution at vdUTPase Ser-187 in part restored the wild-type viral replication and virulence. Interestingly, the S187A mutation in vdUTPase had no effect on viral replication and pathogenic effects in the eyes and vaginas of mice after ocular and vaginal inoculation, respectively. Similarly, the enzyme-dead mutation in vdUTPase significantly reduced viral replication and virulence in the CNS of mice after intracranial inoculation, whereas the mutation had no effect on viral replication and pathogenic effects in the eyes and vaginas of mice after ocular and vaginal inoculation, respectively. These observations suggested that vdUTPase was one of the Us3 substrates responsible for Us3 pathogenicity in the CNS and that the CNS-specific virulence of HSV-1 involved strict regulation of vdUTPase activity by Us3 phosphorylation. IMPORTANCE Herpes simplex virus 1 (HSV-1) encodes a viral protein kinase Us3 which is critical for pathogenicity both in peripheral sites and in the central nervous systems (CNS) of mice following peripheral and intracranial inoculations, respectively. Whereas some Us3

  18. THE ASSOCIATION BETWEEN PHYSIOLOGIC DEAD-SPACE FRACTION AND MORTALITY IN PATIENTS WITH THE ACUTE RESPIRATORY DISTRESS SYNDROME ENROLLED INTO A PROSPECTIVE MULTI-CENTERED CLINICAL TRIAL

    PubMed Central

    Kallet, Richard H; Zhuo, Hanjing; Liu, Kathleen D.; Calfee, Carolyn S.; Matthay, Michael A

    2014-01-01

    Objective To test the association between pulmonary dead-space fraction (VD/VT) and mortality in patients with ARDS (Berlin Definition, PaO2/FiO2 ≤ 300 mm Hg; PEEP ≥ 5 cm H2O) enrolled into a clinical trial incorporating lung-protective ventilation. Design Prospective, multi-center study. Setting Medical-surgical intensive care units in the United States. Subjects 126 ALI patients enrolled into a phase III randomized, placebo-controlled study of aerosolized albuterol. Interventions None Measurements and Main Results VD/VT and pulmonary mechanics were measured within 4 hours of enrollment and repeated daily on study days 1 and 2 in subjects requiring arterial blood gases for clinical management. At baseline, non-survivors had a trend towards higher VD/VT compared to survivors (0.62 ± 0.11 vs. 0.56 ± 0.11 respectively, p = 0.08). Differences in VD/VT between non-survivors and survivors became significant on study days 1 (0.64 ± 0.12 vs. 0.55 ± 0.11 respectively, p = 0.01) and 2 (0.67 ± 0.12 vs. 0.56 ± 0.11 respectively, p=0.004). Likewise, the association between VD/VT and mortality was significant on study day 1 (odds ratio per 0.10 change in VD/VT [95% confidence interval]: 6.84 [1.62–28.84] p = 0.01; and study day 2: 4.90 [1.28–18.73] p = 0.02) after adjusting for VD/VT, PaO2/FiO2, oxygenation index, vasopressor use and the primary risk for ARDS. Using a Cox proportional hazard model, VD/VT was associated with a trend towards higher mortality (HR = 4.37 [CI: 0.99 – 19.32]; p = 0.052) that became significant when the analysis was adjusted for daily oxygenation index (HR = 1.74 [95% CI: 1.12 – 3.35] p = 0.04). Conclusions Markedly elevated VD/VT (≥ 0.60) in early ARDS is associated with higher mortality. Measuring VD/VT may be useful in identifying ARDS patients at increased risk of death who are enrolled into a therapeutic trial. PMID:24381187

  19. Vestibular and oculomotor influences on visual dependency

    PubMed Central

    Da Silva Melo, Mariane; Siddiqui, Aazim A.; Arshad, Qadeer; Patel, Mitesh

    2016-01-01

    The degree to which a person relies on visual stimuli for spatial orientation is termed visual dependency (VD). VD is considered a perceptual trait or cognitive style influenced by psychological factors and mediated by central reweighting of the sensory inputs involved in spatial orientation. VD is often measured with the rod-and-disk test, in which participants align a central rod to the subjective visual vertical (SVV) in the presence of a background that is either stationary or rotating around the line of sight—dynamic SVV. Although this task has been employed to assess VD in health and vestibular disease, what effect torsional nystagmic eye movements may have on individual performance is unknown. Using caloric ear irrigation, 3D video-oculography, and the rod-and-disk test, we show that caloric torsional nystagmus modulates measures of VD and demonstrate that increases in tilt after irrigation are positively correlated with changes in ocular torsional eye movements. When the direction of the slow phase of the torsional eye movement induced by the caloric is congruent with that induced by the rotating visual stimulus, there is a significant increase in tilt. When these two torsional components are in opposition, there is a decrease. These findings show that measures of VD can be influenced by oculomotor responses induced by caloric stimulation. The findings are of significance for clinical studies, as they indicate that VD, which often increases in vestibular disorders, is modulated not only by changes in cognitive style but also by eye movements, in particular nystagmus. PMID:27358321

  20. The alterations of Ca2+/calmodulin/CaMKII/CaV1.2 signaling in experimental models of Alzheimer's disease and vascular dementia.

    PubMed

    Min, Dongyu; Guo, Feng; Zhu, Shu; Xu, Xiaoxue; Mao, Xiaoyuan; Cao, Yonggang; Lv, Xintong; Gao, Qinghua; Wang, Lei; Chen, Tianbao; Shaw, Chris; Hao, Liying; Cai, Jiqun

    2013-03-22

    The two critical forms of dementia are Alzheimer's disease (AD) and vascular dementia (VD). The alterations of Ca(2+)/calmodulin/CaMKII/CaV1.2 signaling in AD and VD have not been well elucidated. Here we have demonstrated changes in the levels of CaV1.2, calmodulin, p-CaMKII, p-CREB and BDNF proteins by Western blot analysis and the co-localization of p-CaMKII/CaV1.2 by double-labeling immunofluorescence in the hippocampus of APP/PS1 mice and VD gerbils. Additionally, expression of these proteins and intracellular calcium levels were examined in cultured neurons treated with Aβ1-42. The expression of CaV1.2 protein was increased in VD gerbils and in cultured neurons but decreased in APP/PS1 mice; the expression of calmodulin protein was increased in APP/PS1 mice and VD gerbils; levels of p-CaMKII, p-CREB and BDNF proteins were decreased in AD and VD models. The number of neurons in which p-CaMKII and CaV1.2 were co-localized, was decreased in the CA1 and CA3 regions in two models. Intracellular calcium was increased in the cultured neurons treated with Aβ1-42. Collectively, our results suggest that the alterations in CaV1.2, calmodulin, p-CaMKII, p-CREB and BDNF can be reflective of an involvement in the impairment in memory and cognition in AD and VD models.

  1. Differential expression of cartilage and bone-related proteins in pediatric and adult diseased aortic valves.

    PubMed

    Wirrig, Elaine E; Hinton, Robert B; Yutzey, Katherine E

    2011-03-01

    Approximately 5 million people are affected with aortic valve disease (AoVD) in the United States. The most common treatment is aortic valve (AoV) replacement surgery, however, replacement valves are susceptible to failure, necessitating additional surgeries. The molecular mechanisms underlying disease progression and late AoV calcification are not well understood. Recent studies suggest that genes involved in bone and cartilage development play an active role in osteogenic-like calcification in human calcific AoVD (CAVD). In an effort to define the molecular pathways involved in AoVD progression and calcification, expression of markers of valve mesenchymal progenitors, chondrogenic precursors, and osteogenic differentiation was compared in pediatric non-calcified and adult calcified AoV specimens. Valvular interstitial cell (VIC) activation, extracellular matrix (ECM) disorganization, and markers of valve mesenchymal and skeletal chondrogenic progenitor cells were observed in both pediatric and adult AoVD. However, activated BMP signaling, increased expression of cartilage and bone-type collagens, and increased expression of the osteogenic marker Runx2 are observed in adult diseased AoVs. They are not observed in the majority of pediatric diseased valves, representing a marked distinction in the molecular profile between pediatric and adult diseased AoVs. The combined evidence suggests that an actively regulated osteochondrogenic disease process underlies the pathological changes affecting AoVD progression, ultimately resulting in stenotic AoVD. Both pediatric and adult diseased AoVs express protein markers of valve mesenchymal and chondrogenic progenitor cells while adult diseased AoVs also express proteins involved in osteogenic calcification. These findings provide specific molecular indicators of AoVD progression, which may lead to identification of early disease markers and the development of potential therapeutics.

  2. Van der Waals Epitaxial Growth of Two-Dimensional Single-Crystalline GaSe Domains on Graphene.

    PubMed

    Li, Xufan; Basile, Leonardo; Huang, Bing; Ma, Cheng; Lee, Jaekwang; Vlassiouk, Ivan V; Puretzky, Alexander A; Lin, Ming-Wei; Yoon, Mina; Chi, Miaofang; Idrobo, Juan C; Rouleau, Christopher M; Sumpter, Bobby G; Geohegan, David B; Xiao, Kai

    2015-08-25

    Two-dimensional (2D) van der Waals (vdW) heterostructures are a family of artificially structured materials that promise tunable optoelectronic properties for devices with enhanced functionalities. Compared to transferring, direct epitaxy of vdW heterostructures is ideal for clean interlayer interfaces and scalable device fabrication. Here we report the synthesis and preferred orientations of 2D GaSe atomic layers on graphene (Gr) by vdW epitaxy. GaSe crystals are found to nucleate predominantly on random wrinkles or grain boundaries of graphene, share a preferred lattice orientation with underlying graphene, and grow into large (tens of micrometers) irregularly shaped, single-crystalline domains. The domains are found to propagate with triangular edges that merge into the large single crystals during growth. Electron diffraction reveals that approximately 50% of the GaSe domains are oriented with a 10.5 ± 0.3° interlayer rotation with respect to the underlying graphene. Theoretical investigations of interlayer energetics reveal that a 10.9° interlayer rotation is the most energetically preferred vdW heterostructure. In addition, strong charge transfer in these GaSe/Gr vdW heterostructures is predicted, which agrees with the observed enhancement in the Raman E(2)1g band of monolayer GaSe and highly quenched photoluminescence compared to GaSe/SiO2. Despite the very large lattice mismatch of GaSe/Gr through vdW epitaxy, the predominant orientation control and convergent formation of large single-crystal flakes demonstrated here is promising for the scalable synthesis of large-area vdW heterostructures for the development of new optical and optoelectronic devices.

  3. Nucleotide Excision Repair and Vitamin D--Relevance for Skin Cancer Therapy.

    PubMed

    Pawlowska, Elzbieta; Wysokinski, Daniel; Blasiak, Janusz

    2016-04-06

    Ultraviolet (UV) radiation is involved in almost all skin cancer cases, but on the other hand, it stimulates the production of pre-vitamin D3, whose active metabolite, 1,25-dihydroxyvitamin D3 (1,25VD3), plays important physiological functions on binding with its receptor (vitamin D receptor, VDR). UV-induced DNA damages in the form of cyclobutane pyrimidine dimers or (6-4)-pyrimidine-pyrimidone photoproducts are frequently found in skin cancer and its precursors. Therefore, removing these lesions is essential for the prevention of skin cancer. As UV-induced DNA damages are repaired by nucleotide excision repair (NER), the interaction of 1,25VD3 with NER components can be important for skin cancer transformation. Several studies show that 1,25VD3 protects DNA against damage induced by UV, but the exact mechanism of this protection is not completely clear. 1,25VD3 was also shown to affect cell cycle regulation and apoptosis in several signaling pathways, so it can be considered as a potential modulator of the cellular DNA damage response, which is crucial for mutagenesis and cancer transformation. 1,25VD3 was shown to affect DNA repair and potentially NER through decreasing nitrosylation of DNA repair enzymes by NO overproduction by UV, but other mechanisms of the interaction between 1,25VD3 and NER machinery also are suggested. Therefore, the array of NER gene functioning could be analyzed and an appropriate amount of 1.25VD3 could be recommended to decrease UV-induced DNA damage important for skin cancer transformation.

  4. Noninvasive quantification of fluid mechanical energy losses in the total cavopulmonary connection with magnetic resonance phase velocity mapping.

    PubMed

    Venkatachari, Anand K; Halliburton, Sandra S; Setser, Randolph M; White, Richard D; Chatzimavroudis, George P

    2007-01-01

    A major determinant of the success of surgical vascular modifications, such as the total cavopulmonary connection (TCPC), is the energetic efficiency that is assessed by calculating the mechanical energy loss of blood flow through the new connection. Currently, however, to determine the energy loss, invasive pressure measurements are necessary. Therefore, this study evaluated the feasibility of the viscous dissipation (VD) method, which has the potential to provide the energy loss without the need for invasive pressure measurements. Two experimental phantoms, a U-shaped tube and a glass TCPC, were scanned in a magnetic resonance (MR) imaging scanner and the images were used to construct computational models of both geometries. MR phase velocity mapping (PVM) acquisitions of all three spatial components of the fluid velocity were made in both phantoms and the VD was calculated. VD results from MR PVM experiments were compared with VD results from computational fluid dynamics (CFD) simulations on the image-based computational models. The results showed an overall agreement between MR PVM and CFD. There was a similar ascending tendency in the VD values as the image spatial resolution increased. The most accurate computations of the energy loss were achieved for a CFD grid density that was too high for MR to achieve under current MR system capabilities (in-plane pixel size of less than 0.4 mm). Nevertheless, the agreement between the MR PVM and the CFD VD results under the same resolution settings suggests that the VD method implemented with a clinical imaging modality such as MR has good potential to quantify the energy loss in vascular geometries such as the TCPC.

  5. On the role of long range interactions for the adsorption of sexithiophene on Ag(110) surface

    SciTech Connect

    Matos, Jeronimo; Rojas, Tomas; Yildirim, Handan E-mail: Abdelkader.Kara@ucf.edu; Kara, Abdelkader E-mail: Abdelkader.Kara@ucf.edu

    2014-04-14

    The adsorption characteristics of the sexithiophene (6T) molecule on Ag(110) are studied using density functional theory with the inclusion of van der Waals (vdW) interactions. The stable adsorption configurations on 6T on Ag(110) as well as the nature of bonding the Ag substrate are evaluated. We also assess the performance of the vdW-DF method in describing the adsorption, energetics, heights, as well as the interface characteristics with the Ag(110) surface. We find two lowest adsorption energy configurations, at which the 6T molecule aligns with its molecular long axis parallel and perpendicular to the [001] direction, to be energetically close to each other, suggesting that they may coexist. Our findings indicate a significant increase in the 6T adsorption energies upon the inclusion of vdW interactions with the highest increase obtained using the opt-type functionals, in particular with the optB86b-vdW functional. The revPBE-vdW and rPW86-vdW2 functionals lead to less enhancement in adsorption energies that is attributed to the strong repulsive nature of these functionals, in agreement with earlier predictions. Upon adsorption of the 6T molecule, the changes in the atomic and electronic structures of the 6T molecule and Ag surface are found to be negligible; there is no charge transfer, and no interface state is observed. The work function is reduced upon adsorption with the largest change is ∼0.6 eV obtained using the optB88-vdW functional. The results are in good agreement with the available experimental observations of the adsorption configurations and the work function changes. Based on our results, we conclude that the nature of bonding for 6T on Ag(110) can be classified as strong physisorption.

  6. Vitamin D for combination photodynamic therapy of skin cancer in individuals with vitamin D deficiency: Insights from a preclinical study in a mouse model of squamous cell carcinoma

    NASA Astrophysics Data System (ADS)

    Anand, Sanjay; Thomas, Erik; Hasan, Tayyaba; Maytin, Edward V.

    2016-03-01

    Combination photodynamic therapy (cPDT) in which vitamin D (VD) is given prior to aminolevulinate, a precursor (pro-drug) for protoporphyrin IX (PpIX), is an approach developed in our laboratory. We previously showed that 1α,25- dihydroxyvitamin D3 (calcitriol), given prior to PDT, enhances accumulation of PpIX and improves cell death post-PDT in a mouse skin cancer model. However, since calcitriol poses a risk for hypercalcemia, we replaced systemic calcitriol with oral cholecalciferol (D3), administered as a high (tenfold, "10K") diet over a ten-day period. Here, we ask whether VD deficiency might alter the response to cPDT. Nude mice were fed a VD-deficient diet for at least 4 weeks ("deficient"); controls were fed a normal 1,000 IU/kg diet ("1K"). Human A431 cells were implanted subcutaneously and mice were switched to the 10K diet or continued on their baseline diets (controls). In other experiments, mice received a human equivalent dose of 50,000 IU D3 by oral gavage, to simulate administration of a single, high-dose VD pill. At various times, tumors were harvested and serum was collected to measure levels of VD metabolic intermediates. A significant increase in PpIX levels and in the expression of differentiation and proliferation markers in tumor tissue was observed after VD supplementation of both the deficient and 1K mice. Further results describing mechanistic details of PpIX enhancement through alteration of heme- and VD-metabolic enzyme levels will be presented. Based on these results, a clinical study using oral vitamin D prior to PDT for human skin cancer should be performed.

  7. Nucleotide Excision Repair and Vitamin D—Relevance for Skin Cancer Therapy

    PubMed Central

    Pawlowska, Elzbieta; Wysokinski, Daniel; Blasiak, Janusz

    2016-01-01

    Ultraviolet (UV) radiation is involved in almost all skin cancer cases, but on the other hand, it stimulates the production of pre-vitamin D3, whose active metabolite, 1,25-dihydroxyvitamin D3 (1,25VD3), plays important physiological functions on binding with its receptor (vitamin D receptor, VDR). UV-induced DNA damages in the form of cyclobutane pyrimidine dimers or (6-4)-pyrimidine-pyrimidone photoproducts are frequently found in skin cancer and its precursors. Therefore, removing these lesions is essential for the prevention of skin cancer. As UV-induced DNA damages are repaired by nucleotide excision repair (NER), the interaction of 1,25VD3 with NER components can be important for skin cancer transformation. Several studies show that 1,25VD3 protects DNA against damage induced by UV, but the exact mechanism of this protection is not completely clear. 1,25VD3 was also shown to affect cell cycle regulation and apoptosis in several signaling pathways, so it can be considered as a potential modulator of the cellular DNA damage response, which is crucial for mutagenesis and cancer transformation. 1,25VD3 was shown to affect DNA repair and potentially NER through decreasing nitrosylation of DNA repair enzymes by NO overproduction by UV, but other mechanisms of the interaction between 1,25VD3 and NER machinery also are suggested. Therefore, the array of NER gene functioning could be analyzed and an appropriate amount of 1.25VD3 could be recommended to decrease UV-induced DNA damage important for skin cancer transformation. PMID:27058533

  8. Vinyl-Deoxyadenosine in a Sarcin/Ricin RNA Loop and its Binding to Ricin Toxin A-Chain

    PubMed Central

    Roday, Setu; Saen-oon, Suwipa; Schramm, Vern L.

    2008-01-01

    8-Vinyl-2’-deoxyadenosine (8vdA) is a fluorophore with a quantum yield comparable to 2-aminopurine nucleoside. 8vdA was incorporated into a 10-mer stem-tetraloop RNA (8vdA-10) structure to characterize the properties of the base, 8-vinyladenine (8-vA), with respect to adenine as a substrate or inhibitor for ribosome inactivating proteins. Ricin Toxin A-chain (RTA) and Pokeweed Antiviral Protein (PAP) catalyze the release of adenine from a specific adenosine on a stem-tetraloop (GAGA) sequence at the elongation factor (eEF2) binding site of the 28S subunit of eukaryotic ribosomes, thereby arresting translation. RTA does not catalyze 8-vinyladenine release from 8vdA-10. Molecular dynamics simulations implicate a role for Arg 180 in oxacarbenium ion destabilization and lack of catalysis. However, 8vdA-10 is an active site analog and inhibits RTA with a Ki value of 2.4 μM. Adenine is also released from the second adenosine in the modified tetraloop demonstrating an alternative mode for the binding of this motif in the RTA active site. The 8vdA analog defines the specificities of RTA for the two adenylate depurination sites in an RNA substrate with a GAGA tetraloop. The rate of non-enzymatic acid-catalyzed solvolysis of 8-vinyladenine from the stem-loop RNA is described. Unlike RTA, PAP catalyzes the slow release of 8-vinyladenine from 8vdA-10. The isolation of 8-vA and its physicochemical characterization is described. PMID:17477546

  9. Effect of Vitamin D on basal and Luteinizing Hormone (LH) induced testosterone production and mitochondrial dehydrogenase activity in cultured Leydig cells from immature and mature rams.

    PubMed

    Huang, Yang; Jin, Hui; Chen, Jianwei; Jiang, Xiaolong; Li, Pengfei; Ren, Youshe; Liu, Wenzhong; Yao, Jianbo; Folger, Joseph K; Smith, George W; Lv, Lihua

    2015-07-01

    The objectives of this study were to investigate the potential effects of 1α,25-(OH)2VD3 (biologically active form of Vitamin D) on basal and LH-induced testosterone production and mitochondrial dehydrogenase activity in Leydig cells from immature and mature rams cultured in vitro. Leydig cells were isolated from testes of immature and mature rams, treated without (control) or with increasing concentrations of LH (1, 10, 100ng/ml) and/or 1α,25-(OH)2VD3 (1, 10, 100nM). After 24h, concentrations of testosterone in culture media were measured. After 96h, mitochondrial dehydrogenase activity in Leydig cells were measured. In immature and mature ram Leydig cells, treatment with 10 and 100ng/ml LH increased testosterone production and mitochondrial dehydrogenase activity. Treatment with 1α,25-(OH)2VD3 in the absence of LH did not increase testosterone production, but 10 and 100nM 1α,25-(OH)2VD3 increased LH induced testosterone production for both immature and mature ram Leydig cells. Treatment with all doses of 1α,25-(OH)2VD3 in the absence of LH and 10 and 100ng/ml LH in the absence of 1α,25-(OH)2VD3 increased mitochondrial dehydrogenase activity for cultured Leydig cells from immature and mature rams and 1 and 10nM 1α,25-(OH)2VD3 treatment enhanced the LH induced increase in mitochondrial dehydrogenase activity. Result demonstrate Vitamin D3 induced regulation of function of Leydig cells from immature and mature rams cultured in the presence or absence of LH and support a potential role for Vitamin D3 in regulation of gonadal function in rams.

  10. Cotransport of clay colloids and viruses through water-saturated vertically oriented columns packed with glass beads: Gravity effects.

    PubMed

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2016-03-01

    The cotransport of clay colloids and viruses in vertically oriented laboratory columns packed with glass beads was investigated. Bacteriophages MS2 and ΦX174 were used as model viruses, and kaolinite (ΚGa-1b) and montmorillonite (STx-1b) as model clay colloids. A steady flow rate of Q=1.5 mL/min was applied in both vertical up (VU) and vertical down (VD) flow directions. In the presence of KGa-1b, estimated mass recovery values for both viruses were higher for VD than VU flow direction, while in the presence of STx-1b the opposite was observed. However, for all cases examined, the produced mass of viruses attached onto suspended clay particles were higher for VD than VU flow direction, suggesting that the flow direction significantly influences virus attachment onto clays, as well as packed column retention of viruses attached onto suspended clays. KGa-1b hindered the transport of ΦX174 under VD flow, while STx-1b facilitated the transport of ΦX174 under both VU and VD flow directions. Moreover, KGa-1b and STx-1b facilitated the transport of MS2 in most of the cases examined except of the case where KGa-1b was present under VD flow. Also, the experimental data were used for the estimation of virus surface-coverages and virus surface concentrations generated by virus diffusion-limited attachment, as well as virus attachment due to sedimentation. Both sedimentation and diffusion limited virus attachment were higher for VD than VU flow, except the case of MS2 and STx-1b cotransport. The diffusion-limited attachment was higher for MS2 than ΦΧ174 for all cases examined.

  11. Ligand selectivity in tachykinin and natalisin neuropeptidergic systems of the honey bee parasitic mite Varroa destructor.

    PubMed

    Jiang, Hongbo; Kim, Donghun; Dobesh, Sharon; Evans, Jay D; Nachman, Ronald J; Kaczmarek, Krzysztof; Zabrocki, Janusz; Park, Yoonseong

    2016-01-28

    The varroa mite, Varroa destructor, is a devastating ectoparasite of the honey bees Apis mellifera and A. cerana. Control of these mites in beehives is a challenge in part due to the lack of toxic agents that are specific to mites and not to the host honey bee. In searching for a specific toxic target of varroa mites, we investigated two closely related neuropeptidergic systems, tachykinin-related peptide (TRP) and natalisin (NTL), and their respective receptors. Honey bees lack both NTL and the NTL receptor in their genome sequences, providing the rationale for investigating these receptors to understand their specificities to various ligands. We characterized the receptors for NTL and TRP of V. destructor (VdNTL-R and VdTRP-R, respectively) and for TRP of A. mellifera (AmTRP-R) in a heterologous reporter assay system to determine the activities of various ligands including TRP/NTL peptides and peptidomimetics. Although we found that AmTRP-R is highly promiscuous, activated by various ligands including two VdNTL peptides when a total of 36 ligands were tested, we serendipitously found that peptides carrying the C-terminal motif -FWxxRamide are highly specific to VdTRP-R. This motif can serve as a seed sequence for designing a VdTRP-R-specific agonist.

  12. Ligand selectivity in tachykinin and natalisin neuropeptidergic systems of the honey bee parasitic mite Varroa destructor

    PubMed Central

    Jiang, Hongbo; Kim, Donghun; Dobesh, Sharon; Evans, Jay D.; Nachman, Ronald J.; Kaczmarek, Krzysztof; Zabrocki, Janusz; Park, Yoonseong

    2016-01-01

    The varroa mite, Varroa destructor, is a devastating ectoparasite of the honey bees Apis mellifera and A. cerana. Control of these mites in beehives is a challenge in part due to the lack of toxic agents that are specific to mites and not to the host honey bee. In searching for a specific toxic target of varroa mites, we investigated two closely related neuropeptidergic systems, tachykinin-related peptide (TRP) and natalisin (NTL), and their respective receptors. Honey bees lack both NTL and the NTL receptor in their genome sequences, providing the rationale for investigating these receptors to understand their specificities to various ligands. We characterized the receptors for NTL and TRP of V. destructor (VdNTL-R and VdTRP-R, respectively) and for TRP of A. mellifera (AmTRP-R) in a heterologous reporter assay system to determine the activities of various ligands including TRP/NTL peptides and peptidomimetics. Although we found that AmTRP-R is highly promiscuous, activated by various ligands including two VdNTL peptides when a total of 36 ligands were tested, we serendipitously found that peptides carrying the C-terminal motif -FWxxRamide are highly specific to VdTRP-R. This motif can serve as a seed sequence for designing a VdTRP-R-specific agonist. PMID:26817786

  13. Vibration of Piezoelectric ZnO-SWCNT Nanowires

    PubMed Central

    Xiao, Yao; Wang, Chengyuan; Feng, Yuantian

    2016-01-01

    A hybrid nanowire (HNW) was constructed by coating a single-wall carbon nanotube (SWCNT) with piezoelectric zinc oxide (ZnO). The two components of the HNW interact with each other via the van der Waals (vdW) force. This paper aims to study the effect of the piezoelectricity in the ZnO layer and the inter-phase vdW interaction on the fundamental vibration of the HNWs. In doing this, a new model was developed where the two components of the HNWs were modeled as Euler beams coupled via the interphase vdW interaction. Based on the model, the dependence of the frequency on an applied electrical voltage was calculated for HNWs of different geometric sizes to reveal the voltage effect. The results were then compared with those calculated without considering the inter-phase vdW interaction. It was found that the interphase vdW interaction can substantially decrease the structural stiffness, leading to a greatly enhanced piezoelectric effect but a lower frequency for the vibration of the HNWs. PMID:28335370

  14. Delivery route preferences of urban women of low socioeconomic status*

    PubMed Central

    Kudish, Bela; Mehta, Shobha; Kruger, Michael; Russell, Evie; Sokol, Robert J.

    2010-01-01

    Objective To identify the main determinants of mode of delivery preference among urban dwelling women of lower socioeconomic status (SES). Methods Over a 12-month period, a self-completion 36-item questionnaire was administered to a convenience sample of 308 women within the first 3 postpartum days. Non-parametric tests were used for analysis. Results Study participants were mostly African American (>85%), single mothers (>75%), and unemployed (≥55%). Among the women, 85.7% had vaginal delivery (VD) and 14.3% had cesarean delivery (CD). Women who preferred CD (10%) were more likely to be concerned about a vaginal tear/episiotomy during VD, forceps, and a "big" baby compared with women who preferred VD, for whom “pushing the baby out myself” and “fear of cesarean” were the most important factors. In the final model of 7 factors, the 3 main factors found to positively impact maternal preference for CD were a vaginal cut during VD (P<0.001), higher mean BMI (P=0.001), and cesarean as the most recent delivery type (P<0.001). The total explained variance by this model was 46%. Conclusions Short-term complications of a VD, higher BMI, and a previous cesarean delivery are the most significant factors that impact the preferences of women of lower SES for future mode of delivery. PMID:20579999

  15. Stabilization of thin liquid films by repulsive van der Waals force.

    PubMed

    Li, Er Qiang; Vakarelski, Ivan U; Chan, Derek Y C; Thoroddsen, Sigurdur T

    2014-05-13

    Using high-speed video recording of bubble rise experiments, we study the stability of thin liquid films trapped between a rising bubble and a surfactant-free liquid-liquid meniscus interface. Using different combinations of nonpolar oils and water that are all immiscible, we investigate the extent to which film stability can be predicted by attractive and repulsive van der Waals (vdW) interactions that are indicated by the relative magnitude of the refractive indices of the liquid combinations, for example, water (refractive index, n = 1.33), perfluorohexane (n = 1.23), and tetradecane (n = 1.43). We show that, when the film-forming phase was oil (perfluorohexane or tetradecane), the stability of the film could always be predicted from the sign of the vdW interaction, with a repulsive vdW force resulting in a stable film and an attractive vdW force resulting in film rupture. However, if aqueous electrolyte is the film-forming bulk phase between the rising air bubble and the upper oil phase, the film always ruptured, even when a repulsive vdW interaction was predicted. We interpret these results as supporting the hypothesis that a short-ranged hydrophobic attraction determines the stability of the thin water film formed between an air phase and a nonpolar oil phase.

  16. High-Resolution Variable-Density 3D Cones Coronary MRA

    PubMed Central

    Addy, Nii Okai; Ingle, R. Reeve; Wu, Holden H.; Hu, Bob S.; Nishimura, Dwight G.

    2015-01-01

    Purpose To improve the spatial/temporal resolution of whole-heart coronary MR angiography (CMRA) by developing a variable-density (VD) 3D cones acquisition suitable for image reconstruction with parallel imaging and compressed sensing techniques. Methods A VD 3D cones trajectory design incorporates both radial and spiral trajectory undersampling techniques to achieve higher resolution. This design is used to generate a VD cones trajectory with 0.8 mm/66 ms isotropic spatial/temporal resolution, using a similar number of readouts as our previous fully sampled cones trajectory (1.2 mm/100 ms). Scans of volunteers and patients are performed to evaluate the performance of the VD trajectory, using non-Cartesian L1-ESPIRiT for high-resolution image reconstruction. Results With gridding reconstruction, the high-resolution scans experience an expected drop in signal-to-noise and contrast-to-noise ratios, but with L1-ESPIRiT, the apparent noise is substantially reduced. Compared to 1.2 mm images, in each volunteer, the L1-ESPIRiT 0.8 mm images exhibit higher vessel sharpness values in the right and left anterior descending arteries. Conclusion CMRA with isotropic sub-millimeter spatial resolution and high temporal resolution can be performed with VD 3D cones to improve the depiction of coronary arteries. PMID:26172829

  17. Evolution of Moiré Profiles from van der Waals Superstructures of Boron Nitride Nanosheets

    PubMed Central

    Liao, Yunlong; Cao, Wei; Connell, John W.; Chen, Zhongfang; Lin, Yi

    2016-01-01

    Two-dimensional (2D) van der Waals (vdW) superstructures, or vdW solids, are formed by the precise restacking of 2D nanosheet lattices, which can lead to unique physical and electronic properties that are not available in the parent nanosheets. Moiré patterns formed by the crystalline mismatch between adjacent nanosheets are the most direct features for vdW superstructures under microscopic imaging. In this article, transmission electron microscopy (TEM) observation of hexagonal Moiré patterns with unusually large micrometer-sized lateral areas (up to ~1 μm2) and periodicities (up to ~50 nm) from restacking of liquid exfoliated hexagonal boron nitride nanosheets (BNNSs) is reported. This observation was attributed to the long range crystallinity and the contaminant-free surfaces of these chemically inert nanosheets. Parallel-line-like Moiré fringes with similarly large periodicities were also observed. The simulations and experiments unambiguously revealed that the hexagonal patterns and the parallel fringes originated from the same rotationally mismatched vdW stacking of BNNSs and can be inter-converted by simply tilting the TEM specimen following designated directions. This finding may pave the way for further structural decoding of other 2D vdW superstructure systems with more complex Moiré images. PMID:27188697

  18. Cerebrovascular Diseases in Workers at Mayak PA: The Difference in Radiation Risk between Incidence and Mortality

    PubMed Central

    Simonetto, Cristoforo; Schöllnberger, Helmut; Azizova, Tamara V.; Grigoryeva, Evgenia S.; Pikulina, Maria V.; Eidemüller, Markus

    2015-01-01

    A detailed analysis of cerebrovascular diseases (CeVD) for the cohort of workers at Mayak Production Association (PA) is presented. This cohort is especially suitable for the analysis of radiation induced circulatory diseases, due to the detailed medical surveillance and information on several risk factors. The risk after external, typically protracted, gamma exposure is analysed, accounting for potential additional internal alpha exposure. Three different endpoints have been investigated: incidence and mortality from all cerebrovascular diseases and incidence of stroke. Particular emphasis was given to the form of the dose-response relationship and the time dependence of the radiation induced risk. Young attained age was observed to be an important, aggravating modifier of radiation risk for incidence of CeVD and stroke. For incidence of CeVD, our analysis supports a dose response sub-linear for low doses. Finally, the excess relative risk per dose was confirmed to be significantly higher for incidence of CeVD compared to CeVD mortality and incidence of stroke. Arguments are presented for this difference to be based on a true biological effect. PMID:25933038

  19. Tunable GaTe-MoS2 van der Waals p-n Junctions with Novel Optoelectronic Performance.

    PubMed

    Wang, Feng; Wang, Zhenxing; Xu, Kai; Wang, Fengmei; Wang, Qisheng; Huang, Yun; Yin, Lei; He, Jun

    2015-11-11

    P-n junctions based on vertically stacked van der Waals (vdW) materials have attracted a great deal of attention and may open up unforeseen opportunities in electronics and optoelectronics. However, due to the lack of intrinsic p-type vdW materials, most previous studies generally adopted electrical gating, special electrode contacts, or chemical doping methods to realize p-n vdW junctions. GaTe is an intrinsic p-type vdW material with a relatively high charge density, and it has a direct band gap that is independent of thickness. Here, we report the construction of ultrathin and tunable p-GaTe/n-MoS2 vdW heterostructure with high photovoltaic and photodetecting performance. The rectification ratio, external quantum efficiency, and photoresponsivity are as high as 4 × 10(5), 61.68%, and 21.83 AW(-1), respectively. In particular, the detectivity is up to 8.4 × 10(13) Jones, which is even higher than commercial Si, InGaAs photodetectors. This study demonstrates the promising potential of p-GaTe/n-MoS2 heterostructures for next-generation electronic and optoelectronic devices.

  20. Evolution of Moiré Profiles from van der Waals Superstructures of Boron Nitride Nanosheets.

    PubMed

    Liao, Yunlong; Cao, Wei; Connell, John W; Chen, Zhongfang; Lin, Yi

    2016-05-18

    Two-dimensional (2D) van der Waals (vdW) superstructures, or vdW solids, are formed by the precise restacking of 2D nanosheet lattices, which can lead to unique physical and electronic properties that are not available in the parent nanosheets. Moiré patterns formed by the crystalline mismatch between adjacent nanosheets are the most direct features for vdW superstructures under microscopic imaging. In this article, transmission electron microscopy (TEM) observation of hexagonal Moiré patterns with unusually large micrometer-sized lateral areas (up to ~1 μm(2)) and periodicities (up to ~50 nm) from restacking of liquid exfoliated hexagonal boron nitride nanosheets (BNNSs) is reported. This observation was attributed to the long range crystallinity and the contaminant-free surfaces of these chemically inert nanosheets. Parallel-line-like Moiré fringes with similarly large periodicities were also observed. The simulations and experiments unambiguously revealed that the hexagonal patterns and the parallel fringes originated from the same rotationally mismatched vdW stacking of BNNSs and can be inter-converted by simply tilting the TEM specimen following designated directions. This finding may pave the way for further structural decoding of other 2D vdW superstructure systems with more complex Moiré images.

  1. Induction of differentiation of myelogenous leukemia cells by humulone, a bitter in the hop.

    PubMed

    Honma, Y; Tobe, H; Makishima, M; Yokoyama, A; Okabe-Kado, J

    1998-07-01

    The active form of vitamin D, 1alpha,25-dihydroxyvitamin D3 (VD3), inhibits proliferation and induces differentiation of myelomonocytic leukemia cells, but its clinical use is limited by the adverse effect of hypercalcemia. VD3 mobilizes calcium stores from bone by inducing the dissolution of bone mineral and matrix. We have recently found that humulone, a bitter in the hop extract for beer brewing, effectively inhibits bone resorption. In this study we examined the effect of humulone on the differentiation of human myelogenous leukemia cells. Humulone alone inhibited the growth of monoblastic leukemia U937 cells while only slightly increasing differentiation markers such as nitroblue tetrazolium (NBT)-reducing and lysozyme activities. Humulone effectively enhanced the differentiation-inducing action of VD3. Other myelomonocytic leukemia cells were induced to differentiate by VD3 and this was also enhanced by humulone. Since humulone is a less-toxic inhibitor of bone resorption, the combination of humulone and VD3 may be useful in differentiation therapy of myelomonocytic leukemia.

  2. Transition metal dichalcogenide heterojunction PN diode toward ultimate photovoltaic benefits

    NASA Astrophysics Data System (ADS)

    Ahn, Jongtae; Jeon, Pyo Jin; Raza, Syed Raza Ali; Pezeshki, Atiye; Min, Sung-Wook; Hwang, Do Kyung; Im, Seongil

    2016-12-01

    Recently, two-dimensional (2D) transition metal dichalcogenide (TMDC) semiconductors as van der Waals (vdW) materials have attracted much attention from researchers. Among many 2D TMDC materials, a few layer-thin molybdenum disulfide (MoS2) and tungsten diselenide (WSe2) have been most intensively studied respectively as 2D n- and p-type semiconductors. Here, we have fabricated vertical vdW heterojunction n-MoS2/p-WSe2 diode with a few tens nm-thick layers by using vertically-sandwiched ohmic terminals, so that no quasi neutral region may exist between two terminals. As a result, we obtained high photo responsivity at zero volt without any electric power, and it appears comparable to those of commercially-optimized Si PN diode. Photo-voltage output of 0.3 V was easily obtained from our vdW PN diode as open circuit voltage, and can be doubled up to 0.6 V by using two PN diodes. These beneficial photovoltaic results from vdW PN diode were directly applied to PV switching dynamics and transistor photo gating, for the first time. We regard that our vdW n-MoS2/p-WSe2 heterojunction diode could maximize its photovoltaic energy benefits with optimized TMDC thicknesses.

  3. Narrowband Ultraviolet B Exposures Maintain Vitamin D Levels During Winter: A Randomized Controlled Trial.

    PubMed

    Karppinen, Toni; Ala-Houhala, Meri; Ylianttila, Lasse; Kautiainen, Hannu; Viljakainen, Heli; Reunala, Timo; Snellman, Erna

    2016-05-01

    Exposure to solar ultraviolet B radiation during the summer months is the main source of vitamin D (VD) for people living in northern latitudes. The aim of this study was to determine whether artificial narrowband ultraviolet B (NB-UVB) whole-body exposures could maintain VD levels in winter. The intervention group received 2 standard erythema doses (SEDs) of NB-UVB exposures every second week from October 2013 to April 2014. In October 2013 serum 25-hydroxyvitamin D concentrations were 78.3 nmol/l in the intervention group (n = 16) and 76.8 nmol/l in the control group (n = 18). By April 2014 the concentrations had increased by 11.7 nmol/l (p = 0.029) in the intervention group and decreased by 11.1 nmol/l (p = 0.022) in the control group. The baseline VD concentration showed a negative correlation (p = 0.012) with body mass index (BMI). In conclusion, a suberythemal NB-UVB dose of 2 SED every second week maintains and even increases serum VD concentrations during the winter. A high BMI seems to predispose subjects to low levels of VD.

  4. Internal anatomy and ultrastructure of the male reproductive system of the spider crab Maja brachydactyla (Decapoda: Brachyura).

    PubMed

    Simeó, C G; Ribes, E; Rotllant, G

    2009-10-01

    The morphology and function of the male reproductive system in the spider crab Maja brachydactyla, an important commercial species, is described using light and electron microscopy. The reproductive system follows the pattern found among brachyuran with several peculiarities. The testis, known as tubular testis, consists of a single, highly coiled seminiferous tubule divided all along by an inner epithelium into germinal, transformation, and evacuation zones, each playing a different role during spermatogenesis. The vas deferens (VD) presents diverticula increasing in number and size towards the median VD, where spermatophores are stored. The inner monostratified epithelium exocytoses the materials involved in the spermatophore wall formation (named substance I and II) and spermatophore storage in the anterior and median VD, respectively. A large accessory gland is attached to the posterior VD, and its secretions are released as granules in apocrine secretion, and stored in the lumen of the diverticula as seminal fluids. A striated musculature may contribute to the formation and movement of spermatophores and seminal fluids along the VD. The ejaculatory duct (ED) shows a multilayered musculature and a nonsecretory pseudostratified epithelium, and extrudes the reproductive products towards the gonopores. A tissue attached to the ED is identified as the androgenic gland.

  5. Primary hyperparathyroidism and vitamin D deficiency.

    PubMed

    Vélayoudom-Céphise, Fritz-Line; Wémeau, Jean-Louis

    2015-05-01

    Primary hyperparathyroidism (PHPT) and vitamin D (VD) deficiency are frequent conditions due to the widespread application of assays for calcium and VD. PHPT presentation is dominated by diversity in its expression and the current predominance of asymptomatic forms. VD, which plays a major role in calcium and phosphate homeostasis, is also involved in many physiological processes in this disease, such as lipid and glucose metabolism, and in the signalling pathways and functioning of many cell types. The bone and cardiometabolic complications described in PHPT are exacerbated by vitamin D deficiency, the prevalence of which varies according to many parameters (environment, skin pigmentation, associated chronic diseases, liver and kidney function, assay kit used, etc.). In response to this observation, experts in field from medical societies validated the indication for systematic assay of VD occurring with PHPT and the need for replacement in case of deficiency. Several epidemiological studies have confirmed that replacement with natural vitamin D is well tolerated and safe in subjects with PHPT and VD deficiency. This supplementation reduces hyperparathormonemia, does not have symptomatic effects on calciuria, and especially improves the bone and functional condition of patients.

  6. Communication: Accurate higher-order van der Waals coefficients between molecules from a model dynamic multipole polarizability

    SciTech Connect

    Tao, Jianmin; Rappe, Andrew M.

    2016-01-21

    Due to the absence of the long-range van der Waals (vdW) interaction, conventional density functional theory (DFT) often fails in the description of molecular complexes and solids. In recent years, considerable progress has been made in the development of the vdW correction. However, the vdW correction based on the leading-order coefficient C{sub 6} alone can only achieve limited accuracy, while accurate modeling of higher-order coefficients remains a formidable task, due to the strong non-additivity effect. Here, we apply a model dynamic multipole polarizability within a modified single-frequency approximation to calculate C{sub 8} and C{sub 10} between small molecules. We find that the higher-order vdW coefficients from this model can achieve remarkable accuracy, with mean absolute relative deviations of 5% for C{sub 8} and 7% for C{sub 10}. Inclusion of accurate higher-order contributions in the vdW correction will effectively enhance the predictive power of DFT in condensed matter physics and quantum chemistry.

  7. On the accuracy of van der Waals inclusive density-functional theory exchange-correlation functionals for ice at ambient and high pressures

    NASA Astrophysics Data System (ADS)

    Santra, Biswajit; Klimeš, Jiří; Tkatchenko, Alexandre; Alfè, Dario; Slater, Ben; Michaelides, Angelos; Car, Roberto; Scheffler, Matthias

    2013-10-01

    Density-functional theory (DFT) has been widely used to study water and ice for at least 20 years. However, the reliability of different DFT exchange-correlation (xc) functionals for water remains a matter of considerable debate. This is particularly true in light of the recent development of DFT based methods that account for van der Waals (vdW) dispersion forces. Here, we report a detailed study with several xc functionals (semi-local, hybrid, and vdW inclusive approaches) on ice Ih and six proton ordered phases of ice. Consistent with our previous study [B. Santra, J. Klimeš, D. Alfè, A. Tkatchenko, B. Slater, A. Michaelides, R. Car, and M. Scheffler, Phys. Rev. Lett. 107, 185701 (2011)] which showed that vdW forces become increasingly important at high pressures, we find here that all vdW inclusive methods considered improve the relative energies and transition pressures of the high-pressure ice phases compared to those obtained with semi-local or hybrid xc functionals. However, we also find that significant discrepancies between experiment and the vdW inclusive approaches remain in the cohesive properties of the various phases, causing certain phases to be absent from the phase diagram. Therefore, room for improvement in the description of water at ambient and high pressures remains and we suggest that because of the stern test the high pressure ice phases pose they should be used in future benchmark studies of simulation methods for water.

  8. On the accuracy of van der Waals inclusive density-functional theory exchange-correlation functionals for ice at ambient and high pressures.

    PubMed

    Santra, Biswajit; Klimes, Jirí; Tkatchenko, Alexandre; Alfè, Dario; Slater, Ben; Michaelides, Angelos; Car, Roberto; Scheffler, Matthias

    2013-10-21

    Density-functional theory (DFT) has been widely used to study water and ice for at least 20 years. However, the reliability of different DFT exchange-correlation (xc) functionals for water remains a matter of considerable debate. This is particularly true in light of the recent development of DFT based methods that account for van der Waals (vdW) dispersion forces. Here, we report a detailed study with several xc functionals (semi-local, hybrid, and vdW inclusive approaches) on ice Ih and six proton ordered phases of ice. Consistent with our previous study [B. Santra, J. Klimeš, D. Alfè, A. Tkatchenko, B. Slater, A. Michaelides, R. Car, and M. Scheffler, Phys. Rev. Lett. 107, 185701 (2011)] which showed that vdW forces become increasingly important at high pressures, we find here that all vdW inclusive methods considered improve the relative energies and transition pressures of the high-pressure ice phases compared to those obtained with semi-local or hybrid xc functionals. However, we also find that significant discrepancies between experiment and the vdW inclusive approaches remain in the cohesive properties of the various phases, causing certain phases to be absent from the phase diagram. Therefore, room for improvement in the description of water at ambient and high pressures remains and we suggest that because of the stern test the high pressure ice phases pose they should be used in future benchmark studies of simulation methods for water.

  9. Versatile van der Waals Density Functional Based on a Meta-Generalized Gradient Approximation

    NASA Astrophysics Data System (ADS)

    Peng, Haowei; Yang, Zeng-Hui; Perdew, John P.; Sun, Jianwei

    2016-10-01

    A "best-of-both-worlds" van der Waals (vdW) density functional is constructed, seamlessly supplementing the strongly constrained and appropriately normed (SCAN) meta-generalized gradient approximation for short- and intermediate-range interactions with the long-range vdW interaction from r VV 10 , the revised Vydrov-van Voorhis nonlocal correlation functional. The resultant SCAN +r VV 10 is the only vdW density functional to date that yields excellent interlayer binding energies and spacings, as well as intralayer lattice constants in 28 layered materials. Its versatility for various kinds of bonding is further demonstrated by its good performance for 22 interactions between molecules; the cohesive energies and lattice constants of 50 solids; the adsorption energy and distance of a benzene molecule on coinage-metal surfaces; the binding energy curves for graphene on Cu(111), Ni(111), and Co(0001) surfaces; and the rare-gas solids. We argue that a good semilocal approximation should (as SCAN does) capture the intermediate-range vdW through its exchange term. We have found an effective range of the vdW interaction between 8 and 16 Å for systems considered here, suggesting that this interaction is negligibly small at the larger distances where it reaches its asymptotic power-law decay.

  10. Thermopower distribution of single molecule junctions with different interaction types

    NASA Astrophysics Data System (ADS)

    Kim, Taekyeong

    2015-11-01

    The thermopower (S) distribution in single-molecule junctions with different interaction types were investigated by using a scanning tunneling microscope break-junction (STM-BJ) technique. We used 4,4'-bipyridine (BPy) and 1,2-bis(4-pyridyl)ethylene (BPyE) molecules, each having the Van der Waals (vdW) interaction between a pyridine ring and a Au atom and a donor-acceptor (DA) interaction between a nitrogen(N) atom and a Au atom, depending on the different binding geometries formed with the Au electrodes. From the full width at half maximum (FWHM) in the distribution of S, we found that S had a smaller variation for the vdW interaction compared to the DA interaction, due to the high binding stability of vdW interaction. Furthermore, we measured the molecular bonding forces which are in the range of 1.5 nN - 1.8 nN for the vdW interaction and 0.8 nN for the DA interaction. This confirms that the bonding is stronger for the vdW interaction than for the DA interaction, which is consistent with the experimental results for the S distributions as well as those for the molecular bonding stabilities.

  11. Usefulness of minipigs for predicting human pharmacokinetics: Prediction of distribution volume and plasma clearance.

    PubMed

    Yoshimatsu, Hiromichi; Konno, Yoshihiro; Ishii, Kunikazu; Satsukawa, Masahiro; Yamashita, Shinji

    2016-02-01

    In this study, advantages of minipigs to use in preclinical study for new drug development were evaluated in terms of prediction of human pharmacokinetic (PK) parameters of various drugs. Fourteen model drugs having diverse physicochemical properties were selected and intravenously administered to mice, rats and minipigs to obtain their PK parameters. The human volume of distribution (Vd) and clearance (CL) of model drugs were predicted from PK parameters in each animal species. When Vd of 14 drugs in each species were directly compared with those in humans, minipigs showed the highest correlation. Correction of Vd with an unbound fraction of drugs in tissues further improved the correlation. Allometric scaling that included minipig data resulted in high accuracy in the prediction of human Vd, clearly indicating an importance of minipig data. Minipigs also showed the high predictability of human CL. The prediction of human CL by allometric scaling showed a high accuracy when the data of minipigs were included. In conclusion, potential advantages of minipigs for predicting human Vd and CL were clearly demonstrated. Reliable prediction of human PK from data of minipigs appears to be possible in preclinical PK study, without relying on PK analysis in other species.

  12. Volumetric capnography and chronic obstructive pulmonary disease staging

    PubMed Central

    Romero, Pablo V; Rodriguez, Benigno; de Oliveira, Daniela; Blanch, L; Manresa, Federico

    2007-01-01

    Spirometry is difficult for some COPD patient to perform. Volumetric capnography could be a second choice test to evaluate the severity of functional disturbances. The aim of this work is to test this hypothesis. A total number of 98 subjects were classified either as normal ex-smokers (N = 14) or COPD patients. The latter were staged following GOLD recommendations. Spirometry and volumetric capnography recordings were obtained from each patient. Spirometry parameters, Bohr Dead Space (VD Bohr), Airways Dead Space from the pre-interface expirate corrected curve (VD aw), Phase III slope (SlIII) and Volume of alveolar ejection (VAE) were measured. Index of Ventilatory Efficiency (IVE), and Index of Airways Heterogeneity (IAH) were calculated as: IVE = VAE/(VT – VD aw) and IAH = 1 – [(VT – VD Bohr)/(VT – VD aw)]. In ANOCOVA analysis IAH showed the greatest association with stage (F > 40), with no significant covariant dependence on VT. A receiver operating characteristics curve analysis showed values of the area under the curve greater than 0.9 for IAH and IVE at all stage levels, with a sensitivity = specificity value greater than 80%. We conclude that IAH and IVE can be used when spirometry cannot be reliably performed, as an alternative test to evaluate the degree of functional involvement in COPD patients. PMID:18229577

  13. Effect of gravity on virus and clay colloid cotransport through vertical water-saturated columns

    NASA Astrophysics Data System (ADS)

    Syngouna, Vasiliki I.; Chrysikopoulos, Constantinos V.

    2015-04-01

    The cotransport of clay colloids and viruses in vertically oriented laboratory columnspacked with glass beadswas investigated. Bacteriophages MS2 and ΦX174 were used as model viruses, and kaolinite (kGa-1b) and montmorillonite (STx-1b) as model clay colloids. A steady flow rate of Q=1.5 mL/min was applied in bothvertical upward (VU) and vertically downward (VD) flowdirections. For most of the cases examined in this study, estimated mass recovery values were higher for VD than VU flows, suggesting that the flow direction significantly influenced particle deposition.KGa-1b hindered the transport of ΦX174 under VD flow conditions,while STx-1b facilitated the transport of ΦX174 under both VU and VD flow conditions. Moreover, KGa-1b hindered,while STx-1b facilitated the transport of MS2 in all of thecases examined. Also, the experimental data were used for the estimation of virus surface-coverages, and virus surface concentrations for virus diffusion-limited adsorption, and virus adsorption by sedimentation. The sedimentation limited virus adsorption was higher for VD than VU flows, and the diffusion-limited adsorption was higher for MS2 than ΦX174.

  14. Increased circulating VCAM-1 correlates with advanced disease and poor survival in patients with multiple myeloma: reduction by post-bortezomib and lenalidomide treatment

    PubMed Central

    Terpos, E; Migkou, M; Christoulas, D; Gavriatopoulou, M; Eleutherakis-Papaiakovou, E; Kanellias, N; Iakovaki, M; Panagiotidis, I; Ziogas, D C; Fotiou, D; Kastritis, E; Dimopoulos, M A

    2016-01-01

    Circulating vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and selectins were prospectively measured in 145 newly-diagnosed patients with symptomatic myeloma (NDMM), 61 patients with asymptomatic/smoldering myeloma (SMM), 47 with monoclonal gammopathy of undetermined significance (MGUS) and 87 multiple myeloma (MM) patients at first relapse who received lenalidomide- or bortezomib-based treatment (RD, n=47; or VD, n=40). Patients with NDMM had increased VCAM-1 and ICAM-1 compared with MGUS and SMM patients. Elevated VCAM-1 correlated with ISS-3 and was independently associated with inferior overall survival (OS) (45 months for patients with VCAM-1 >median vs 75 months, P=0.001). MM patients at first relapse had increased levels of ICAM-1 and L-selectin, even compared with NDMM patients and had increased levels of VCAM-1 compared with MGUS and SMM. Both VD and RD reduced dramatically serum VCAM-1 after four cycles of therapy, but only VD reduced serum ICAM-1, irrespective of response to therapy. The reduction of VCAM-1 was more pronounced after RD than after VD. Our study provides evidence for the prognostic value of VCAM-1 in myeloma patients, suggesting that VCAM-1 could be a suitable target for the development of anti-myeloma therapies. Furthermore, the reduction of VCAM-1 and ICAM-1 by RD and VD supports the inhibitory effect of these drugs on the adhesion of MM cells to stromal cells. PMID:27232930

  15. The role of van der Waals interactions in the adsorption of noble gases on metal surfaces

    SciTech Connect

    Chen, De-Li; Al-Saidi, W A; Johnson, J Karl

    2012-10-03

    Adsorption of noble gases on metal surfaces is determined by weak interactions. We applied two versions of the nonlocal van der Waals density functional (vdW-DF) to compute adsorption energies of Ar, Kr, and Xe on Pt(111), Pd(111), Cu(111), and Cu(110) metal surfaces. We have compared our results with data obtained using other density functional approaches, including the semiempirical vdW corrected DFT-D2. The vdW-DF results show considerable improvements in the description of adsorption energies and equilibrium distances over other DFTbased methods, giving good agreement with experiments. We have also calculated perpendicular vibrational energies for noble gases on the metal surfaces using vdWDF data and found excellent agreement with available experimental results. Our vdW-DF calculations show that adsorption of noble gases on low-coordination sites is energetically favored over high-coordination sites, but only by a few meV. Analysis of the 2-dimensional potential energy surface shows that the high-coordination sites are local maxima on the 2-dimensional potential energy surface and therefore unlikely to be observed in experiments, which provides an explanation of the experimental observations. The DFT-D2 approach with the standard parameterization was found to overestimate the dispersion interactions, and to give the wrong adsorption site preference for four of the nine systems we studied.

  16. Evolution of Moiré Profiles from van der Waals Superstructures of Boron Nitride Nanosheets

    NASA Astrophysics Data System (ADS)

    Liao, Yunlong; Cao, Wei; Connell, John W.; Chen, Zhongfang; Lin, Yi

    2016-05-01

    Two-dimensional (2D) van der Waals (vdW) superstructures, or vdW solids, are formed by the precise restacking of 2D nanosheet lattices, which can lead to unique physical and electronic properties that are not available in the parent nanosheets. Moiré patterns formed by the crystalline mismatch between adjacent nanosheets are the most direct features for vdW superstructures under microscopic imaging. In this article, transmission electron microscopy (TEM) observation of hexagonal Moiré patterns with unusually large micrometer-sized lateral areas (up to ~1 μm2) and periodicities (up to ~50 nm) from restacking of liquid exfoliated hexagonal boron nitride nanosheets (BNNSs) is reported. This observation was attributed to the long range crystallinity and the contaminant-free surfaces of these chemically inert nanosheets. Parallel-line-like Moiré fringes with similarly large periodicities were also observed. The simulations and experiments unambiguously revealed that the hexagonal patterns and the parallel fringes originated from the same rotationally mismatched vdW stacking of BNNSs and can be inter-converted by simply tilting the TEM specimen following designated directions. This finding may pave the way for further structural decoding of other 2D vdW superstructure systems with more complex Moiré images.

  17. Plant-Derived Tick Repellents Activate the Honey Bee Ectoparasitic Mite TRPA1.

    PubMed

    Peng, Guangda; Kashio, Makiko; Morimoto, Tomomi; Li, Tianbang; Zhu, Jingting; Tominaga, Makoto; Kadowaki, Tatsuhiko

    2015-07-14

    We have identified and characterized the TRPA1 channel of Varroa destructor (VdTRPA1), a major ectoparasitic mite of honey bee. One of the two VdTRPA1 isoforms, VdTRPA1L, was activated by a variety of plant-derived compounds, including electrophilic compounds, suggesting that chemical activation profiles are mostly shared between arthropod TRPA1 channels. Nevertheless, carvacrol and α-terpineol activated VdTRPA1L but not a honey bee noxious-stimuli-sensitive TRPA, AmHsTRPA, and Drosophila melanogaster TRPA1. Activation of VdTRPA1L in D. melanogaster taste neurons by the above compounds was sufficient to modify the gustatory behaviors. Carvacrol and α-terpineol repelled V. destructor in a laboratory assay, and α-terpineol repressed V. destructor entry for reproduction into the brood cells in hives. Understanding the functions of parasite TRP channels not only gives clues about the evolving molecular and cellular mechanisms of parasitism but also helps in the development of control methods.

  18. Structural evolution of amino acid crystals under stress from a non-empirical density functional

    NASA Astrophysics Data System (ADS)

    Sabatini, Riccardo; Küçükbenli, Emine; Kolb, Brian; Thonhauser, T.; de Gironcoli, Stefano

    2012-10-01

    Use of the non-local correlation functional vdW-DF (from ‘van der Waals density functional’ Dion M et al 2004 Phys. Rev. Lett. 92 246401) has become a popular approach for including van der Waals interactions within density functional theory. In this work, we extend the vdW-DF theory and derive the corresponding stress tensor in a fashion similar to the LDA and GGA approach, which allows for a straightforward implementation in any electronic structure code. We then apply our methodology to investigate the structural evolution of amino acid crystals of glycine and l-alanine under pressure up to 10 GPa—with and without van der Waals interactions—and find that for an accurate description of intermolecular interactions and phase transitions in these systems, the inclusion of van der Waals interactions is crucial. For glycine, calculations including the vdW-DF (vdW-DF-c09x) functional are found to systematically overestimate (underestimate) the crystal lattice parameters, yet the stability ordering of the different polymorphs is determined accurately, at variance with the GGA case. In the case of l-alanine, our vdW-DF results agree with recent experiments that question the phase transition reported for this crystal at 2.3 GPa, as the a and c cell parameters happen to become equal but no phase transition is observed.

  19. Probing the relation between protein-protein interactions and DNA binding for a linker mutant of the bacterial nucleoid protein H-NS.

    PubMed

    Giangrossi, Mara; Wintraecken, Kathelijne; Spurio, Roberto; de Vries, Renko

    2014-02-01

    We have investigated the relationship between oligomerization in solution and DNA binding for the bacterial nucleoid protein H-NS. This was done by comparing oligomerization and DNA binding of H-NS with that of a H-NS D68V-D71V linker mutant. The double linker mutation D68V-D71V, that makes the linker significantly more hydrophobic, leads to a dramatically enhanced and strongly temperature-dependent H-NS oligomerization in solution, as detected by dynamic light scattering. The DNA binding affinity of H-NS D68V-D71V for the hns promoter region is lower and has stronger temperature dependence than that of H-NS. DNase I footprinting experiments show that at high concentrations, regions protected by H-NS D68V-D71V are larger and less defined than for H-NS. In vitro transcription assays show that the enhanced protection also leads to enhanced transcriptional repression. Whereas the lower affinity of the H-NS D68V-D71V for DNA could be caused by competition between oligomerization in solution and oligomerization on DNA, the larger size of protected regions clearly confirms the notion that cooperative binding of H-NS to DNA is related to protein-protein interactions. These results emphasize the relative contributions of protein-protein interactions and substrate-dependent oligomerization in the control of gene repression operated by H-NS.

  20. Evidence that natural benzodiazepine-like compounds increase during spontaneous labour.

    PubMed

    Facchinetti, Fabio; Avallone, Rossella; Modugno, Giuseppe; Baraldi, Mario

    2006-01-01

    Natural benzodiazepine-like compounds (NBDZ) are present in the blood of normal people free of commercial benzodiazepine medication. In this work, we evaluated the levels of NBDZ in maternal/foetal serum during delivery after spontaneous labour (VD) or caesarean section (CS). For both the VD (n=11) and the CS (n=11) groups (VD+CS=22), three blood samples were collected at three different times: the first was collected three days before labour, the second immediately after delivery or at fetal abdominal extraction and the third one was obtained at second day post-partum. NBDZ were measured by radioreceptor binding assay after HPLC extraction and purification while cortisol was measured through radioimmunoassay. In the VD group, a significant increase of NBDZ levels occurred at labour in comparison with the levels found in pre- and post-partum periods. By the contrary, no differences in NBDZ levels were found in the CS group at the three different times. The levels of cortisol in the VD group were found to be higher at labour than that determined at pre- and post-partum. Again no significant changes were found in the CS group. These findings suggest for the first time that labour is associated with a marked increase of NBDZ which could be envisaged as a stress-related event.

  1. [Science and society. Guidelines for the Leopoldina Study Center].

    PubMed

    Hacker, Jörg

    2014-01-01

    In order to adequately perform its many diverse tasks as a scholars' society and as the German National Academy of Sciences, the Deutsche Akademie der Naturforscher Leopoldina needs to view itself in a historical context. This can only happen as part of a culture of remembrance which fosters the memory of the Leopoldina's past and subjects this to a critical analysis in the context of the history of science and academies. The newly founded Leopoldina Study Center for the History of Science and Science Academies is to be a forum that pursues established forms of historical research at the Leopoldina, organizes new scientific projects, and presents its findings to the public. The aim is to involve as many Leopoldina members as possible from all of its disciplines, as well as to collaborate with national and international partners.

  2. On the theory of the Balmer series⋆. Presented at the meeting on 6 December 1915

    NASA Astrophysics Data System (ADS)

    Sommerfeld, A.

    2014-04-01

    The German original was published as "Zur Theorie der Balmerschen Serie" in Sitzungsberichte der mathematisch-physikalischen Klasse der K. B. Akademie der Wissenschaften zu München, 1915, S. 425-458; it is available as electronic supplementary material at http://dx.doi.org/10.1140/epjh/e2013-40053-8 or in the printed collection, Eckert, M. and Sommerfeld, A. (2013). Die Bohr-Sommerfeldsche Atomtheorie: Sommerfelds Erweiterung des Bohrschen Atommodells 1915/16. Klassische Texte der Wissenschaft. Springer, Berlin, Heidelberg.The translation here is by Patrick D.F. Ion, 1456 Kensington Drive, Ann Arbor, MI 48104-6214; e-mail: ion@ams.org. The numbers in the margins indicate the starts of original pages translated. The footnote numbering has been changed from the original to match the English text.

  3. The fine structure of Hydrogen and Hydrogen-like lines⋆. Presented at the meeting on 8 January 1916

    NASA Astrophysics Data System (ADS)

    Sommerfeld, A.

    2014-04-01

    The German original was published as "Die Feinstruktur der Wasserstoff- und der Wasserstoff-ähnlichen Linien" in Sitzungsberichte der mathematisch-physikalischen Klasse der K. B. Akademie der Wissenschaften zu München, 1915, S. 459-500; it is available as electronic supplementary material at http://dx.doi.org/10.1140/epjh/e2013-40054-0 or in the printed collection, Eckert, M. and Sommerfeld, A. (2013). Die Bohr-Sommerfeldsche Atomtheorie: Sommerfelds Erweiterung des Bohrschen Atommodells 1915/16. Klassische Texte der Wissenschaft. Springer, Berlin, Heidelberg.The translation here is by Patrick D. F. Ion, 1456 Kensington Drive, Ann Arbor, MI 48104-6214; e-mail: ion@ams.org. The numbers in the margins indicate the starts of original pages translated. The footnote numbering has been changed from the original to match the English text.

  4. A theoretical and experimental investigation on the adsorption of pentacene on the Cu(322) surface

    NASA Astrophysics Data System (ADS)

    Matos, Jeronimo; Sauvage-Simkin, Michele; Coati, Alessandro; Garreau, Yves; Vlad, Alina; Muller, Kathrin; Bendounan, Azzedine; Kara, Abdelkader

    In this study, complementary techniques including density functional theory (DFT), grazing incidence x-ray diffraction (GIXD), and scanning tunneling microscopy (STM) are used to study the surface distortions induced by the adsorption of pentacene on the stepped Cu(322) surface. GIXD measurements are performed for the clean Cu(322) surface and at various coverages of pentacene, up to one monolayer. For the one monolayer case, reciprocal space maps from GIXD measurement suggest the reconstruction of the steps to double the step width and height, with two pentacene molecules present at each terrace. Complementary DFT calculations are carried out, with and without the self-consistent inclusion of vdW interactions, using the optB88-vdW and PBE functionals. Our investigation illustrates a prototype method for conducting future benchmarking studies to assess the accuracy of the current self-consistent vdW functionals when applied to organic molecule adsorption.

  5. Nanomechanical probing of the layer/substrate interface of an exfoliated InSe sheet on sapphire

    PubMed Central

    Beardsley, Ryan; Akimov, Andrey V.; Greener, Jake D. G.; Mudd, Garry W.; Sandeep, Sathyan; Kudrynskyi, Zakhar R.; Kovalyuk, Zakhar D.; Patanè, Amalia; Kent, Anthony J.

    2016-01-01

    Van der Waals (vdW) layered crystals and heterostructures have attracted substantial interest for potential applications in a wide range of emerging technologies. An important, but often overlooked, consideration in the development of implementable devices is phonon transport through the structure interfaces. Here we report on the interface properties of exfoliated InSe on a sapphire substrate. We use a picosecond acoustic technique to probe the phonon resonances in the InSe vdW layered crystal. Analysis of the nanomechanics indicates that the InSe is mechanically decoupled from the substrate and thus presents an elastically imperfect interface. A high degree of phonon isolation at the interface points toward applications in thermoelectric devices, or the inclusion of an acoustic transition layer in device design. These findings demonstrate basic properties of layered structures and so illustrate the usefulness of nanomechanical probing in nanolayer/nanolayer or nanolayer/substrate interface tuning in vdW heterostructures. PMID:27256805

  6. Quantitative structure-pharmacokinetic relationship (QSPkP) analysis of the volume of distribution values of anti-infective agents from J group of the ATC classification in humans.

    PubMed

    Louis, Bruno; Agrawal, Vijay K

    2012-11-01

    In this study, a quantitative structure-pharmacokinetic relationship (QSPkR) model for the volume of distribution (Vd) values of 126 anti-infective drugs in humans was developed employing multiple linear regression (MLR), artificial neural network (ANN) and support vector regression (SVM) using theoretical molecular structural descriptors. A correlation-based feature selection (CFS) was employed to select the relevant descriptors for modeling. The model results show that the main factors governing Vd of anti-infective drugs are 3D molecular representations of atomic van der Waals volumes and Sanderson electronegativities, number of aliphatic and aromatic amino groups, number of beta-lactam rings and topological 2D shape of the molecule. Model predictivity was evaluated by external validation, using a variety of statistical tests and the SVM model demonstrated better performance compared to other models. The developed models can be used to predict the Vd values of anti-infective drugs.

  7. Verticillium dahliae toxins-induced nitric oxide production in Arabidopsis is major dependent on nitrate reductase.

    PubMed

    Shi, Fu-Mei; Li, Ying-Zhang

    2008-01-31

    The source of nitric oxide (NO) in plants is unclear and it has been reported NO can be produced by nitric oxide synthase (NOS) like enzymes and by nitrate reductase (NR). Here we used wild-type, Atnos1 mutant and nia1, nia2 NR-deficient mutant plants of Arabidopsis thaliana to investigate the potential source of NO production in response to Verticillium dahliae toxins (VD-toxins). The results revealed that NO production is much higher in wild-type and Atnos1 mutant than in nia1, nia2 NR-deficient mutants. The NR inhibitor had a significant effect on VD-toxins-induced NO production; whereas NOS inhibitor had a slight effect. NR activity was significantly implicated in NO production. The results indicated that as NO was induced in response to VD-toxins in Arabidopsis, the major source was the NR pathway. The production of NOS-system appeared to be secondary.

  8. Two-Dimensional Semiconductor Optoelectronics Based on van der Waals Heterostructures

    PubMed Central

    Lee, Jae Yoon; Shin, Jun-Hwan; Lee, Gwan-Hyoung; Lee, Chul-Ho

    2016-01-01

    Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDCs) and black phosphorous have drawn tremendous attention as an emerging optical material due to their unique and remarkable optical properties. In addition, the ability to create the atomically-controlled van der Waals (vdW) heterostructures enables realizing novel optoelectronic devices that are distinct from conventional bulk counterparts. In this short review, we first present the atomic and electronic structures of 2D semiconducting TMDCs and their exceptional optical properties, and further discuss the fabrication and distinctive features of vdW heterostructures assembled from different kinds of 2D materials with various physical properties. We then focus on reviewing the recent progress on the fabrication of 2D semiconductor optoelectronic devices based on vdW heterostructures including photodetectors, solar cells, and light-emitting devices. Finally, we highlight the perspectives and challenges of optoelectronics based on 2D semiconductor heterostructures. PMID:28335321

  9. Nanocavity Integrated van der Waals Heterostructure Light-Emitting Tunneling Diode.

    PubMed

    Liu, Chang-Hua; Clark, Genevieve; Fryett, Taylor; Wu, Sanfeng; Zheng, Jiajiu; Hatami, Fariba; Xu, Xiaodong; Majumdar, Arka

    2017-01-11

    Developing a nanoscale, integrable, and electrically pumped single mode light source is an essential step toward on-chip optical information technologies and sensors. Here, we demonstrate nanocavity enhanced electroluminescence in van der Waals heterostructures (vdWhs) at room temperature. The vertically assembled light-emitting device uses graphene/boron nitride as top and bottom tunneling contacts and monolayer WSe2 as an active light emitter. By integrating a photonic crystal cavity on top of the vdWh, we observe the electroluminescence is locally enhanced (>4 times) by the nanocavity. The emission at the cavity resonance is single mode and highly linearly polarized (84%) along the cavity mode. By applying voltage pulses, we demonstrate direct modulation of this single mode electroluminescence at a speed of ∼1 MHz, which is faster than most of the planar optoelectronics based on transition metal chalcogenides (TMDCs). Our work shows that cavity integrated vdWhs present a promising nanoscale optoelectronic platform.

  10. General van der Waals potential for common organic molecules.

    PubMed

    Qi, Rui; Wang, Qiantao; Ren, Pengyu

    2016-10-15

    This work presents a systematic development of a new van der Waals potential (vdW2016) for common organic molecules based on symmetry-adapted perturbation theory (SAPT) energy decomposition. The Buf-14-7 function, as well as Cubic-mean and Waldman-Hagler mixing rules were chosen given their best performance among other popular potentials. A database containing 39 organic molecules and 108 dimers was utilized to derive a general set of vdW parameters, which were further validated on nucleobase stacking systems and testing organic dimers. The vdW2016 potential is anticipated to significantly improve the accuracy and transferability of new generations of force fields for organic molecules.

  11. The vibration of nanosprings affected by van der Waals interactions.

    PubMed

    Zhao, Junhua; Ben, Sudong; Yu, Peishi

    2016-10-01

    The vibration of tightly helical nanosprings affected by van der Waals (vdW) interactions is investigated based on continuum modelling. Explicit solutions are derived to clarify the influence of initial pitch, stiffness and the number of nanosprings on the period, frequency and amplitude of the vibration. Unlike classic linear/nonlinear springs, the waveform of the vibration is always asymmetric for tightly helical nanosprings due to the asymmetry of vdW attraction and repulsion. The at most three equilibrium positions for the nanosprings strongly depend on the deformation due to competition between the vdW interactions and the elastic energy of the nanosprings. This study provides physical insights into the origin of the novel dynamic properties of such nanosprings.

  12. East-west asymmetry in type-2 echoes and enhanced electron drift in the equatorial electrojet

    NASA Astrophysics Data System (ADS)

    Tsunoda, Roland T.; Ecklund, Warner L.

    2002-04-01

    Simultaneous measurements of type-2 echoes in the equatorial electrojet (EEJ) and the 150 km echoes were made with a tri-beam radar on Pohnpei (Federated States of Micronesia). Using the mean Doppler velocity (<VD>) to estimate the line-of-sight component of electron drift velocity ([(V_e)]), we show that its vertical component (Vez) increases with altitude and exceeds Vez measured at 150 km, between 96 and 103 km. At 103 km, the ratio of vertical <VD> to Vez at 150 km was five. This enhancement explains the hitherto puzzling east-west asymmetry in <VD> of type-2 echoes. More importantly, we show how the enhanced Vez appears to be associated with the discrepancy in the altitude of peak current density of the EEJ, between measurement and model. We discuss roles played by kilometer-scale irregularities and close by describing apparent effects by atmospheric gravity waves.

  13. Endogenous estimation of safety coefficient for optimal design of biochemical reactors at industrial level

    NASA Astrophysics Data System (ADS)

    Siontorou, Christina G.; Karydi, Angeliki

    2012-12-01

    This work deals with the endogenous estimation of the Safety Coefficient Ge = Vd/Vm, where Vd is the design volume and Vm is the mean volume of liquid of a biochemical reactor operating at industrial level. The Vd-value is estimated through Monte Carlo simulation while Vm-value is obtained by means of material balances and biochemical kinetics. A case example on waste water biological treatment is presented, referring to a well-mixed bioreactor followed by a clarifier. The Ge-values finally estimated are in the lower part of the (exogenously determined) region as suggested in the relevant technical literature, implying a significant saving of investment capital, which forms the principle component of fixed cost. Similar applications are also mentioned in brief.

  14. Anisotropic rectifying characteristics induced by the superconducting gap of YBa2Cu3O7-δ/Nb-doped SrTiO3 heterojunctions

    NASA Astrophysics Data System (ADS)

    Zhang, M. J.; Hao, F. X.; Zhang, C.; Liu, X.; Li, X. G.

    2015-11-01

    In this paper, we investigated the anisotropic rectifying characteristics of a YBa2Cu3O7-δ (YBCO)/Nb-doped SrTiO3 heterojunction in magnetic fields of up to 9 T by rotating the junction from H//c to H//ab of the YBCO film. From the temperature and field dependencies of the diffusion potential Vd, we found that the angle-resolved reductions of Vd from its original value, δVd, were induced by the anisotropic superconducting gap Δ of the YBCO. The anisotropic parameter obtained from Δ was close to that obtained from the angular-dependent upper critical fields of the YBCO. This heterojunction is helpful both in investigating the superconducting gap and in designing sensitive superconducting devices.

  15. Excimer Lasers

    DTIC Science & Technology

    1976-06-01

    CONTINUE 46 C HATE CONSTANTS - ELCTRONIC VD=SQRT(2*TE/MASXE)* 3E10 J=NE*E*VD VDISC=V-H*J*A-L*A*E*VD*(NE-NEP)/DT NEP=NE RC=6.38E7*(5QRT(2*TE))**3...TG)/ 3E10 +CSTMDE*P**2*EXP(-VüXE/ +TG)*.25/3EI0 BETAD=CSTMD*P**2*EXP(-VDX/TG)*.25/ 3E10 GAJNE=CSTME*(PX1*EXP(-VEA/TG)/(KAEX*1.5)-2*P*XE*EXP(-VEX/TG...3EI0 +-CSTMDE*(P**2*EXP(-VDXE/TG)*.25)/ 3E10 GAIND=CSTMD*(PD1*EXP(-VDA/TG)/(KADI*12)-P**2*EXP(-VDX/TG)*.25) +/3EI0 C OUTPUT IF(ISTEP/IPrMNT-FL()AT

  16. Towards a more accurate van der Waals density functional

    NASA Astrophysics Data System (ADS)

    Hamada, Ikutaro

    2014-03-01

    The van der Waals density functional (vdW-DF) of Dion et al. [1] has attracted considerable attention, because the functional is able to describe intra- and intermolecular bondings with different natures, e.g., covalent and van der Waals bondings in a seamless fashion within the framework of density functional theory. However, the accuracy of the functional is yet to be improved for the applications to various systems. Here I propose an exchange functional for the second version of vdW-DF [2], which improves the accuracy of vdW-DF. The keys in the improved exchange are the matching to the gradient expansion approximation in the slowly varying limit and the large density gradient behavior set in Becke's exchange (B86b)[3]. Systematic study on gas phase molecules, solids, and molecular adsorption demonstrates the applicability of the proposed functional to a wide variety of materials.

  17. Structure and Formation of Synthetic Hemozoin: Insights from First Principles Calculations

    NASA Astrophysics Data System (ADS)

    Marom, Noa; Tkatchenko, Alexandre; Kapishnikov, Sergey; Kronik, Leeor; Leiserowitz, Leslie

    2011-03-01

    Malaria has reemerged due to parasite resistance to synthetic drugs that act by inhibiting crystallization of the malaria pigment, hemozoin (HZ). Understanding the process of HZ nucleation is therefore vital. The crystal structure of synthetic HZ, β -hematin (β H), has recently been determined via x-ray diffraction. We employ van der Waals (vdW) corrected density functional theory to study the β H crystal and its repeat unit, a heme dimer. We find that vdW interactions play a major role in the binding of the heme dimer and the β H crystal. Accounting for the β H periodicity is a must for obtaining the correct geometry of the heme dimer, due to vdW interactions with adjacent dimers. The different isomers of the heme dimer are close in energy, consistent with the observed pseudo-polymorphism. We use these findings to comment on β H crystallization mechanisms.

  18. Demand and withdraw communication among couples experiencing husband violence.

    PubMed

    Holtzworth-Munroe, A; Smutzler, N; Stuart, G L

    1998-10-01

    Two studies compared marital communication behaviors of violent and nonviolent couples. In Study 1, violent distressed (VD) men reported more husband demand-wife withdraw than did nonviolent men. Distressed men reported less mutual constructive communication and more mutual blame and avoidance than did nondistressed men. Interactions of VD, violent nondistressed (VND), nonviolent distressed (NVD), and nonviolent nondistressed couples were coded in Study 2. VD spouses tended to engage in the most demand and withdraw and the least positive behavior; violent couples had the highest levels of contempt. On some codes, VND couples resembled NVD couples, suggesting that violence without distress may correlate differently with marital communication than violence in combination with distress and that severity of violence is important to consider.

  19. Aggregation of BiTe monolayer on Bi2Te3 (111) induced by diffusion of intercalated atoms in the van der Waals gap

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Wen; Huang, Wen-Kai; Zhang, Kai-Wen; Shu, Da-Jun; Wang, Mu; Li, Shao-Chun

    2017-03-01

    We report a postgrowth aging mechanism of Bi2Te3 (111) films with scanning tunneling microscopy in combination with density functional theory calculation. It is found that a monolayered structure with a squared lattice symmetry gradually aggregates from the surface steps. Theoretical calculations indicate that the van der Waals (vdW) gap not only acts as a natural reservoir for self-intercalated Bi and Te atoms, but also provides them easy diffusion pathways. Once hopping out of the gap, these defective atoms prefer to develop into a two-dimensional BiTe superstructure on the Bi2Te3 (111) surface driven by positive energy gain. Considering the common nature of weak bonding between vdW layers, we expect such unusual diffusion and aggregation of the intercalated atoms may be of general importance for most kinds of vdW layered materials.

  20. Self-consistent study of the Josephson effect for SNS junction with mixed s + d-wave superconductors

    NASA Astrophysics Data System (ADS)

    Zheng, Zhiming; Zhang, Weiyi; Xing, D. Y.

    1998-06-01

    The quasiclassical theory has been applied to study the Josephson junction consisting of mixed s + d-wave superconductors. The order parameter and critical current are calculated selfconsistently for various d-wave ratio vd2 and relative crystal orientation angle θ of the two superconductors. It is found that both the magnitude and the form of critical current depend sensitively on vd2 and θ. For vd2 > 0.63, there always exists an angle θ where the current-phase relation I( fgf) has a period of π instead of 2π in conventional s-wave superconductors. Our result can be used to determine whether the high Tc superconductor is a pure d-wave or mixed s + d-wave superconductor.

  1. Self-consistent van der Waals density functional study of benzene adsorption on Si(100)

    NASA Astrophysics Data System (ADS)

    Hamamoto, Yuji; Hamada, Ikutaro; Inagaki, Kouji; Morikawa, Yoshitada

    2016-06-01

    The adsorption of benzene on the Si(100) surface is studied theoretically using the self-consistent van der Waals density functional (vdW-DF) method. The adsorption energies of two competing adsorption structures, butterfly (BF) and tight-bridge (TB) structures, are calculated with several vdW-DFs at saturation coverage. Our results show that recently proposed vdW-DFs with high accuracy all prefer TB to BF, in accord with more accurate calculations based on exact exchange and correlation within the random-phase approximation. Detailed analyses reveal the important roles played by the molecule-surface interaction and molecular deformation upon adsorption, and we suggest that their precise description is a prerequisite for accurate prediction of the most stable adsorption structure of organic molecules on semiconductor surfaces.

  2. Abnormal distribution of pulmonary blood flow in aortic valve disease

    PubMed Central

    Goodenday, Lucy S.; Simon, George; Craig, Hazel; Dalby, Lola

    1970-01-01

    Wasted ventilatory volume (VD) and its ratio to tidal volume (VD/VT) were measured at rest and during exertion in 17 patients with aortic valve disease. We considered VD/VT to indicate abnormal ventilation: perfusion relations if it did not decrease on exertion, or if the exercising value was greater than 40 per cent. Plain chest radiographs were independently examined for evidence of diversion of pulmonary blood to the upper lobes. There was significant agreement (p<0·05) between radiographic and pulmonary function estimations of abnormality. This suggests that the raised pulmonary venous pressure associated with left ventricular failure creates an abnormal pattern of blood flow through the lung, which is responsible for causing inadequate perfusion with respect to ventilation. Images PMID:5420086

  3. Self-Assembly of Nanoclusters into Mono-, Few-, and Multilayered Sheets via Dipole-Induced Asymmetric van der Waals Attraction.

    PubMed

    Wu, Zhennan; Liu, Jiale; Li, Yanchun; Cheng, Ziyi; Li, Tingting; Zhang, Hao; Lu, Zhongyuan; Yang, Bai

    2015-06-23

    Two-dimensional (2D) nanomaterials possessing regular layered structures and versatile chemical composition are highly expected in many applications. Despite the importance of van der Waals (vdW) attraction in constructing and maintaining layered structures, the origin of 2D anisotropy is not fully understood, yet. Here, we report the 2D self-assembly of ligand-capped Au15 nanoclusters into mono-, few-, and multilayered sheets in colloidal solution. Both the experimental results and computer simulation reveal that the 2D self-assembly is initiated by 1D dipolar attraction common in nanometer-sized objects. The dense 1D attachment of Au15 leads to a redistribution of the surface ligands, thus generating asymmetric vdW attraction. The deliberate control of the coordination of dipolar and vdW attraction further allows to manipulate the thickness and morphologies of 2D self-assembly architectures.

  4. High speed Radix-4 soft-decision Viterbi decoder for MB-OFDM UWB system

    NASA Astrophysics Data System (ADS)

    Liang, Guixuan; Portilla, Jorge; Riesgo, Teresa

    2013-05-01

    In this paper, a 64 state soft decision Viterbi Decoder (VD) system by using a high speed radix-4 Add Compare Select (ACS) architecture is presented. The proposed VD system can support different data rate (from 53.5 Mbps to 480 Mbps) for Multiband Orthogonal Frequency-division Multiplexing (MB-OFDM) Ultra-Wideband (UWB) system when implemented onto the FPGA board. The proposed VD employs efficient two steps Radix 4 architecture, which is responsible of calculating two steps of 64 state Radix 4 Branch Metrics (BM) within one clock cycle. The branch metrics are calculated using a uniform distance measurement algorithm, which equals to the symbol itself when compared to logic-0 and equal to its one's complement when compared to logic-1. By employing the modified Modulo Normalization algorithm, it is possible to use only a 10- bit memory block to restore each of the 64 state metrics, with the advantage of avoiding errors caused by overflow during the updating process for state metrics, and simplifying the comparator circuit of the ACS unit. The Two Pointer Even Algorithm, which is considered to be very simple and more hardware-efficient than the register exchange algorithm, is used for tracing back the survivor sequence and output the decoded data stream. 3-bit soft decision input sequences are used for gathering the experimental results. The sampling frequency of the MBOFDM UWB system is 528 MHz, by using the proposed two steps Radix 4 VD architecture we can process 4 input signals in parallel within one clock cycle, therefore only 132 MHz operating frequency is needed for the proposed VD system. This will dramatically reduce the dynamic power consumption for hardware implementation. Final results of the implementation show that the proposed VD architecture can support a maximum working frequency of 152.5 MHz on Xilinx XUPV5-LX110T Evaluation Platform.

  5. [A technique for a rapid imaging of regional CBF and partition coefficient using dynamic SPECT and N-isopropyl-p-[123I]iodoamphetamine (123I-IMP)].

    PubMed

    Itoh, H; Iida, H; Murakami, M; Bloomfield, P M; Miura, S; Okudera, T; Inugami, A; Ogawa, T; Hatazawa, J; Fujita, H

    1993-01-01

    IMP is a flow tracer due to a large first pass extraction fraction and high affinity in the brain, but significant clearance from the brain causes change of distribution when the scan start time is delayed. The purpose of the present study is to develop a new method to rapidly calculate a quantitative CBF image by taking into account for the clearance effects. A dynamic SPECT scan was performed on 5 subjects (4 patients with cerebral infarction and 1 normal volunteer) following slow intravenous infusion of 123I-IMP. The arterial input function was obtained by frequent blood sampling and by measuring an octanol extraction ratio for each sample. Firstly, non-linear least square fitting (NLS) was performed to investigate the tracer kinetics of 123I-IMP. The 3 compartment model analysis yielded negligibly small k3 (retaining rate constant) (0.0056 +/- 0.0128 (ml/ml/min)), and consistent k1 (transport rate constant) with those determined by 2 compartment model (2CM) analysis (r = 0.96, p < 0.001). In addition, k1 was consistent with CBF measured by 15O water PET technique. These observations suggested validity of using 2CM for describing the IMP tracer kinetics. Secondly, a weighted integration (WI) technique has been implemented to calculate rapidly images of CBF and partition coefficient (Vd). The WI technique yielded values of CBF (k1) and Vd (k1/k2). They were confirmed to be consistent with those determined by NLS technique (CBF; r = 0.99, p < 0.001, Vd; r = 0.99, p < 0.001), and calculated k1 agreed well with PET CBF (r = 0.91, p < 0.001). We observed changed Vd in infarcted patients. This supports an importance for calculating of Vd image. Vd image will provide additional clinical information because 123I-IMP binding mechanism may be related to cell viability.

  6. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

    DOE PAGES

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; ...

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically-thin electronics and optoelectronics due to their diverse functionalities. While heterostructures consisting of different transition metal dichacolgenide monolayers with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. Here, we report the growth of monolayer GaSe/MoSe2 heterostructures with large lattice misfit by two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between themore » two layers, forming an incommensurate vdW heterostructure. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructure at the crystal interface. Such vertically-stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photo-generated charge carriers between layers, resulting in a gate-tunable photovoltaic response. In conclusion, these GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.« less

  7. Nesfatin-1 and Vitamin D levels may be associated with systolic and diastolic blood pressure values and hearth rate in polycystic ovary syndrome.

    PubMed

    Sahin, Figen Kir; Sahin, Serap Baydur; Ural, Ulku Mete; Cure, Medine Cumhur; Senturk, Senol; Tekin, Yesim Bayoglu; Balik, Gulsah; Cure, Erkan; Yuce, Suleyman; Kirbas, Aynur

    2015-07-09

    Obesity, insulin resistance (IR), inflammation, and hyperandrogenism may lead to polycystic ovary syndrome (PCOS) and hypertension. Nesfatin-1 (N1) may be related to IR, obesity, and hypertension. Furthermore, a vitamin D (VD) deficiency is associated with hypertension and PCOS. We aimed to investigate N1 and VD levels in PCOS that have an effect on systolic and diastolic blood pressure (BP) and heart rate (HR).This study included 54 patients with PCOS and 48 age-body mass index (BMI)-matched healthy controls. PCOS was diagnosed according to clinical practice guidelines. Ferriman-Gallwey scores (FGS) were calculated, while N1, VD, and other hormonal and biochemical parameters were measured for all subjects. Systolic and diastolic BP was measured as well. HR was calculated using an electrocardiogram.The levels of N1 (p < 0.001), high-sensitivity C-reactive protein (hs-CRP) (p = 0.036), homeostasis model assessment as an index of insulin resistance (HOMA-IR) (p < 0.001), systolic (p < 0.001) and diastolic (p < 0.001) BP and HR (p < 0.001) in the PCOS group were significantly higher than in the control group. However, the VD levels of the PCOS group were lower than the control group (p = 0.004). N1 had a strong positive correlation with BMI, HOMA-IR, hs-CRP, luteinizing hormone, systolic and diastolic BP, and HR. VD levels were negatively correlated with HOMA-IR and luteinizing hormone.Elevated N1 and decreased VD levels may be related to the presence of high-normal BP or hypertension in PCOS subjects.  N1 level may be associated with an increased BP due to its relation to inflammation and IR.

  8. Effects of alkali supplementation and vitamin D insufficiency on rat skeletal muscle.

    PubMed

    Ceglia, Lisa; Rivas, Donato A; Pojednic, Rachele M; Price, Lori Lyn; Harris, Susan S; Smith, Donald; Fielding, Roger A; Dawson-Hughes, Bess

    2013-10-01

    Data on the independent and potential combined effects of acid-base balance and vitamin D status on muscle mass and metabolism are lacking. We investigated whether alkali supplementation with potassium bicarbonate (KHCO3), with or without vitamin D3 (± VD3), alters urinary nitrogen (indicator of muscle proteolysis), muscle fiber cross-sectional area (FCSA), fiber number (FN), and anabolic (IGF-1, Akt, p70s6k) and catabolic (FOXO3a, MURF1, MAFbx) signaling pathways regulating muscle mass. Thirty-six, 20-month-old, Fischer 344/Brown-Norway rats were randomly assigned in a 2 × 2 factorial design to one of two KHCO3-supplemented diets (± VD3) or diets without KHCO3 (± VD3) for 12 weeks. Soleus, extensor digitorum longus (EDL), and plantaris muscles were harvested at 12 weeks. Independent of VD3 group, KHCO3 supplementation resulted in 35 % lower mean urinary nitrogen to creatinine ratio, 10 % higher mean type I FCSA (adjusted to muscle weight), but no statistically different mean type II FCSA (adjusted to muscle weight) or FN compared to no KHCO3. Among VD3-replete rats, phosphorylated-Akt protein expression was twofold higher in the KHCO3 compared to no KHCO3 groups, but this effect was blunted in rats on VD3-deficient diets. Neither intervention significantly affected serum or intramuscular IGF-1 expression, p70s6k or FOXO3a activation, or MURF1 and MAFbx gene expression. These findings provide support for alkali supplementation as a promising intervention to promote preservation of skeletal muscle mass, particularly in the setting of higher vitamin D status. Additional research is needed in defining the muscle biological pathways that are being targeted by alkali and vitamin D supplementation.

  9. Histochemical examination of adipose derived stem cells combined with β-TCP for bone defects restoration under systemic administration of 1α,25(OH)2D3.

    PubMed

    Feng, Wei; Lv, Shengyu; Cui, Jian; Han, Xiuchun; Du, Juan; Sun, Jing; Wang, Kefeng; Wang, Zhenming; Lu, Xiong; Guo, Jie; Oda, Kimimitsu; Amizuka, Norio; Xu, Xin; Li, Minqi

    2015-09-01

    The purpose of this study was to evaluate the effects of osteogenic differentiated adipose-derived stem cell (ADSC) loaded beta-tricalcium phosphate (β-TCP) in the restoration of bone defects under intraperitoneal administration of 1α,25-dihydroxyvitamin D3(1α,25(OH)2D3). ADSCs were isolated from the fat tissue of 8 week old Wister rats and co-cultured with β-TCP for 21 days under osteogenic induction. Then the ADSC-β-TCP complexes were implanted into bone defects in the femora of rats. 1α,25(OH)2D3 (VD) or normal saline (NS) was administrated intraperitoneally every other day after the surgery. Femora were harvested at day 7, day 14 and day 28 post-surgery. There were 4 groups for all specimens: β-TCP-NS group; β-TCP-ADSC-NS group; β-TCP-VD group and β-TCP-ADSC-VD group. Alkaline phosphatase (ALP) was up-regulated obviously in ADSC groups compared with non-ADSC groups at day 7, day 14 and day 28, although high expression of runt-related transcription factor 2 (RUNX2) was only seen at day 7. Furthermore, the number of TRAP-positive osteoclasts and the expression of cathepsin K (CK) were significantly decreased in VD groups compared with non-VD groups at day 7 and day 14. As a most significant finding, the β-TCP-ADSC-VD group showed the highest BV/TV ratio compared with the other three groups at day 28. Taken together, ADSC-loaded β-TCP under the administration of 1α,25(OH)2D3 made a promising therapy for bone defects restoration.

  10. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

    SciTech Connect

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A.; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T.; Chi, Miaofang; Kravchenko, Ivan; Fowlkes, Jason; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically-thin electronics and optoelectronics due to their diverse functionalities. While heterostructures consisting of different transition metal dichacolgenide monolayers with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) or edge epitaxy, constructing heterostructures from monolayers of layered semiconductors with large lattice misfits still remains challenging. Here, we report the growth of monolayer GaSe/MoSe2 heterostructures with large lattice misfit by two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between the two layers, forming an incommensurate vdW heterostructure. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructure at the crystal interface. Such vertically-stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photo-generated charge carriers between layers, resulting in a gate-tunable photovoltaic response. In conclusion, these GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.

  11. Supersaturating silicon with transition metals by ion implantation and pulsed laser melting

    NASA Astrophysics Data System (ADS)

    Recht, Daniel; Smith, Matthew J.; Charnvanichborikarn, Supakit; Sullivan, Joseph T.; Winkler, Mark T.; Mathews, Jay; Warrender, Jeffrey M.; Buonassisi, Tonio; Williams, James S.; Gradečak, Silvija; Aziz, Michael J.

    2013-09-01

    We investigate the possibility of creating an intermediate band semiconductor by supersaturating Si with a range of transition metals (Au, Co, Cr, Cu, Fe, Pd, Pt, W, and Zn) using ion implantation followed by pulsed laser melting (PLM). Structural characterization shows evidence of either surface segregation or cellular breakdown in all transition metals investigated, preventing the formation of high supersaturations. However, concentration-depth profiling reveals that regions of Si supersaturated with Au and Zn are formed below the regions of cellular breakdown. Fits to the concentration-depth profile are used to estimate the diffusive speeds, vD, of Au and Zn, and put lower bounds on vD of the other metals ranging from 102 to 104 m/s. Knowledge of vD is used to tailor the irradiation conditions and synthesize single-crystal Si supersaturated with 1019 Au/cm3 without cellular breakdown. Values of vD are compared to those for other elements in Si. Two independent thermophysical properties, the solute diffusivity at the melting temperature, Ds(Tm), and the equilibrium partition coefficient, ke, are shown to simultaneously affect vD. We demonstrate a correlation between vD and the ratio Ds(Tm)/ke0.67, which is exhibited for Group III, IV, and V solutes but not for the transition metals investigated. Nevertheless, comparison with experimental results suggests that Ds(Tm)/ke0.67 might serve as a metric for evaluating the potential to supersaturate Si with transition metals by PLM.

  12. Calcium effects and systemic exposure of vitamin D3 analogues after topical treatment of active vitamin D3-containing ointments in rats.

    PubMed

    Hosomi, Atsushi; Hirabe, Maho; Tokuda, Takuya; Nakamura, Hiroaki; Amano, Toru; Okamoto, Tadao

    2016-10-05

    Topical agents containing vitamin D3 (VD3) analogues such as calcipotriol, maxacalcitol and tacalcitol and the combination of calcipotriol/betamethasone dipropionate (betamethasone) are prescribed for patients with psoriasis. However, they are known to occasionally cause hypercalcemia, and the frequency of hypercalcemia is suggested to vary according to the VD3 analogue used. In this study, to address the reason for these differences, the calcemic effects of maxacalcitol-, calcipotriol- and calcipotriol/betamethasone-containing ointments in rats were evaluated. The serum calcium levels in rats treated with ointments containing maxacalcitol, but not calcipotriol or calcipotriol/betamethasone, were significantly elevated, which is consistent with clinical observations. The serum concentration of VD3 analogue in rats treated with ointments containing calcipotriol and calcipotriol/betamethasone was lower than that in rats treated with maxacalcitol-containing ointment. Thus, the calcemic effects appear to be associated with the systemic exposure of VD3 analogues in rats. To understand the mechanism underlying the different systemic exposures of VD3 analogues, skin permeation and metabolic stability of VD3 analogues were evaluated. The cumulative amount of calcipotriol permeated through rat skin was significantly lower than that of maxacalcitol. On the other hand, the metabolic clearance of calcipotriol in rat hepatocytes was higher than that of maxacalcitol. Similar results were obtained using human skin and human hepatocytes. The current study demonstrates that the lower calcemic effects of calcipotriol- and calcipotriol/betamethasone-containing ointments are caused by the low systemic exposure of calcipotriol according to low skin permeability and rapid hepatic elimination after topical application.

  13. Nesfatin-1 and Vitamin D levels may be associated with systolic and diastolic blood pressure values and hearth rate in polycystic ovary syndrome

    PubMed Central

    Sahin, Figen Kir; Sahin, Serap Baydur; Ural, Ulku Mete; Cure, Medine Cumhur; Senturk, Senol; Tekin, Yesim Bayoglu; Balik, Gulsah; Cure, Erkan; Yuce, Suleyman; Kirbas, Aynur

    2015-01-01

    Obesity, insulin resistance (IR), inflammation, and hyperandrogenism may lead to polycystic ovary syndrome (PCOS) and hypertension. Nesfatin-1 (N1) may be related to IR, obesity, and hypertension. Furthermore, a vitamin D (VD) deficiency is associated with hypertension and PCOS. We aimed to investigate N1 and VD levels in PCOS that have an effect on systolic and diastolic blood pressure (BP) and heart rate (HR). This study included 54 patients with PCOS and 48 age-body mass index (BMI)-matched healthy controls. PCOS was diagnosed according to clinical practice guidelines. Ferriman-Gallwey scores (FGS) were calculated, while N1, VD, and other hormonal and biochemical parameters were measured for all subjects. Systolic and diastolic BP was measured as well. HR was calculated using an electrocardiogram. The levels of N1 (p < 0.001), high-sensitivity C-reactive protein (hs-CRP) (p = 0.036), homeostasis model assessment as an index of insulin resistance (HOMA-IR) (p < 0.001), systolic (p < 0.001) and diastolic (p < 0.001) BP and HR (p < 0.001) in the PCOS group were significantly higher than in the control group. However, the VD levels of the PCOS group were lower than the control group (p = 0.004). N1 had a strong positive correlation with BMI, HOMA-IR, hs-CRP, luteinizing hormone, systolic and diastolic BP, and HR. VD levels were negatively correlated with HOMA-IR and luteinizing hormone. Elevated N1 and decreased VD levels may be related to the presence of high-normal BP or hypertension in PCOS subjects. N1 level may be associated with an increased BP due to its relation to inflammation and IR. PMID:26295295

  14. Impact of caesarean section on mode of delivery, pregnancy-induced and pregnancy-associated disorders, and complications in the subsequent pregnancy in Germany

    PubMed Central

    Jacob, Louis; Taskan, Sevil; Macharey, George; Sechet, Ingeborg; Ziller, Volker; Kostev, Karel

    2016-01-01

    Objectives: To analyze the impact of caesarean section (CS) on mode of delivery, pregnancy-induced and pregnancy-associated disorders, as well as complications in the subsequent pregnancy within German gynecological practices. Methods: 1,801 women with CS and 1,801 matched women with vaginal delivery (VD) from the IMS Disease Analyzer database were included. The impact of previous CS on the mode of delivery and pregnancy-associated disorders as well as complications prior to or during birth in the subsequent pregnancy were analyzed. Cox regressions were used to determine the influence of CS with regard to these outcomes. Results: Medical abortion and single spontaneous delivery were significantly less frequent in women with a history of CS compared to VD (OR equal to 0.52 and 0.04 respectively), whereas CS after CS was the significantly more common mode of delivery (79.0% versus 9.3%, OR=36.47). Gestational hypertension without significant proteinuria, gestational hypertension with significant proteinuria, and polyhydramnios were more frequent in women with CS than in women with VD (OR equal to 6.80, 1.71, and 2.29). Hemorrhage and maternal care for known or suspected disproportion were more common in the CS group than in the VD group (OR equal to 1.34 and 3.75). Prolonged pregnancy, preterm labor, abnormalities arising from forces of labor, and perineal laceration during delivery were significantly less frequent in women with CS than in women with VD (OR between 0.32 and 0.75), whereas long labor was more common (OR=2.09). Conclusion: Women with CS were more likely to undergo further CS and to develop major pregnancy-associated diseases in the following pregnancy compared to women with VD. PMID:27346991

  15. Mechanics of rolling of nanoribbon on tube and sphere

    NASA Astrophysics Data System (ADS)

    Yin, Qifang; Shi, Xinghua

    2013-05-01

    The configuration of graphene nano-ribbon (GNR) assembly on carbon nanotube (CNT) and sphere is studied through theoretical modeling and molecular simulation. The GNR can spontaneously wind onto the CNT due to van der Waals (vdW) interaction and form two basic configurations: helix and scroll. The final configuration arises from the competition among three energy terms: the bending energy of the GNR, the vdW interaction between GNR and CNT, the vdW between the GNR itself. We derive analytical solutions by accounting for the three energy parts, with which we draw phase diagrams and predict the final configuration (helix or scroll) based on the selected parameters. The molecular simulations are conducted to verify the model with the results agree well with the model predicted. Our work can be used to actively control and transfer the tube-like nanoparticles and viruses as well as to assemble ribbon-like nanomaterials.The configuration of graphene nano-ribbon (GNR) assembly on carbon nanotube (CNT) and sphere is studied through theoretical modeling and molecular simulation. The GNR can spontaneously wind onto the CNT due to van der Waals (vdW) interaction and form two basic configurations: helix and scroll. The final configuration arises from the competition among three energy terms: the bending energy of the GNR, the vdW interaction between GNR and CNT, the vdW between the GNR itself. We derive analytical solutions by accounting for the three energy parts, with which we draw phase diagrams and predict the final configuration (helix or scroll) based on the selected parameters. The molecular simulations are conducted to verify the model with the results agree well with the model predicted. Our work can be used to actively control and transfer the tube-like nanoparticles and viruses as well as to assemble ribbon-like nanomaterials. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr00489a

  16. Low-sodium Dietary Approaches to Stop Hypertension-type diet including lean red meat lowers blood pressure in postmenopausal women.

    PubMed

    Nowson, Caryl A; Wattanapenpaiboon, Naiyana; Pachett, Annabelle

    2009-01-01

    Low-sodium Dietary Approaches to Stop Hypertension (DASH) diets are base producing but restrict red meat without clear justification. We hypothesized that a vitality diet (VD), a low-sodium DASH-type diet with a low dietary acid load containing 6 servings of 100 g cooked lean red meat per week, would be more effective in reducing blood pressure (BP) compared with a higher acid load reference healthy diet (RHD) based on general dietary guidelines to reduce fat intake and increase intake of breads and cereals. A randomized, parallel dietary intervention study was conducted to compare the BP-lowering effect of these 2 diets in postmenopausal women with high/normal BP. Women were randomly assigned to follow either VD or RHD for 14 weeks. Home BP was measured daily with an automated BP monitor under standard conditions. Of 111 women commencing the study, 95 completed (46 VD, 49 RHD). Systolic BP (SBP) throughout the intervention was lower in the VD group compared to the RHD group (repeated-measures analysis of variance time by diet, P = .04), such that at the end of the study, the VD had a fall of SBP by 5.6 +/- 1.3 mm Hg (mean +/- SEM) compared with a fall of 2.7 +/- 1.0 mm Hg in the RHD (group difference, P = .08). When only those taking antihypertensive medications were assessed, the VD (n = 17) had a significant fall of 6.5 +/- 2.5 mm Hg SBP (P = .02) and 4.6 +/- 1.4 mm Hg diastolic BP (P = .005) after 14 weeks, and their BP was lower than that of the RHD group (n = 18) throughout the study (P < .05). We concluded that a low-sodium DASH diet with a low dietary acid load, which also included lean red meat on most days of the week, was effective in reducing BP in older women, particularly in those taking antihypertensive medications.

  17. Mechanism of augmented exercise hyperpnea in chronic heart failure and dead space loading

    PubMed Central

    Poon, Chi-Sang; Tin, Chung

    2013-01-01

    Patients with chronic heart failure (CHF) suffer increased alveolar VD/VT (dead-space-to-tidal-volume ratio), yet they demonstrate augmented pulmonary ventilation such that arterial PCO2 (PaCO2) remains remarkably normal from rest to moderate exercise. This paradoxical effect suggests that the control law governing exercise hyperpnea is not merely determined by metabolic CO2 production (V̇CO2) per se but is responsive to an apparent (real-feel) metabolic CO2 load (V˙CO2o) that also incorporates the adverse effect of physiological VD/VT on pulmonary CO2 elimination. By contrast, healthy individuals subjected to dead space loading also experience augmented ventilation at rest and during exercise as with increased alveolar VD/VT in CHF, but the resultant response is hypercapnic instead of eucapnic, as with CO2 breathing. The ventilatory effects of dead space loading are therefore similar to those of increased alveolar VD/VT and CO2 breathing combined. These observations are consistent with the hypothesis that the increased series VD/VT in dead space loading adds to V˙CO2o as with increased alveolar VD/VT in CHF, but this is through rebreathing of CO2 in dead space gas thus creating a virtual (illusory) airway CO2 load within each inspiration, as opposed to a true airway CO2 load during CO2 breathing that clogs the mechanism for CO2 elimination through pulmonary ventilation. Thus, the chemosensing mechanism at the respiratory controller may be responsive to putative drive signals mediated by within-breath PaCO2 oscillations independent of breath-to-breath fluctuations of the mean PaCO2 level. Skeletal muscle afferents feedback, while important for early-phase exercise cardioventilatory dynamics, appears inconsequential for late-phase exercise hyperpnea. PMID:23274121

  18. Diaphragm curvature modulates the relationship between muscle shortening and volume displacement.

    PubMed

    Greybeck, Brad J; Wettergreen, Matthew; Hubmayr, Rolf D; Boriek, Aladin M

    2011-07-01

    During physiological spontaneous breathing maneuvers, the diaphragm displaces volume while maintaining curvature. However, with maximal diaphragm activation, curvature decreases sharply. We tested the hypotheses that the relationship between diaphragm muscle shortening and volume displacement (VD) is nonlinear and that curvature is a determinant of such a relationship. Radiopaque markers were surgically placed on three neighboring muscle fibers in the midcostal region of the diaphragm in six dogs. The three-dimensional locations were determined using biplanar fluoroscopy and diaphragm VD, curvature, and muscle shortening were computed in the prone and supine postures during spontaneous breathing (SB), spontaneous inspiration efforts after airway occlusion at lung volumes ranging from functional residual capacity (FRC) to total lung capacity, and during bilateral maximal phrenic nerve stimulation at those same lung volumes. In supine dogs, diaphragm VD was approximately two- to three-fold greater during maximal phrenic nerve stimulation than during SB. The contribution of muscle shortening to VD nonlinearly increases with level of diaphragm activation independent of posture. During submaximal diaphragm activation, the contribution is essentially linear due to constancy of diaphragm curvature in both the prone and supine posture. However, the sudden loss of curvature during maximal bilateral phrenic nerve stimulation at muscle shortening values greater than 40% (ΔL/L(FRC)) causes a nonlinear increase in the contribution of muscle shortening to diaphragm VD, which is concomitant with a nonlinear change in diaphragm curvature. We conclude that the nonlinear relationship between diaphragm muscle shortening and its VD is, in part, due to a loss of its curvature at extreme muscle shortening.

  19. High-Pressure Phase Transition and Stability of CeSb, LaSb, and LuSb with NaCl-TYPE Structure

    NASA Astrophysics Data System (ADS)

    Singh, Sadhna; Singh, R. K.; Gour, Atul

    We have predicted the phase transition pressures and corresponding relative volume changes of CeSb, LaSb, and LuSb having NaCl-type structure under high pressure using three-body interaction potential approach (TBIPA) incorporated with short-range van der Walls (vdW) interaction and zero point energy effects. We have obtained phase transition pressures and relative volume changes which are in close agreement with measured values. Thus TBIPA with vdW interaction and zero point energy effects are found to be promising potential models for the prediction of transition pressure and stability of rare-earth compounds.

  20. Slidable atomic layers in van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Kobayashi, Yu; Taniguchi, Takashi; Watanabe, Kenji; Maniwa, Yutaka; Miyata, Yasumitsu

    2017-04-01

    We report the preparation and manipulation of slidable atomic layers in clean, incommensurate van der Waals (vdW) heterostructures. Monolayer and multilayer WS2 grains are grown on graphite and hexagonal boron nitride (hBN) via chemical vapor deposition, and these grains can slide smoothly on graphite and hBN surfaces by manipulation with a tip. Furthermore, this sliding process allows the suspension, tearing, stacking, and connection of the atomic layers. These results demonstrate a novel approach for developing a wide variety of atomic-layer heterostructures with tunable interlayer coupling and an ideal system for studying the superlubricity of incommensurate, highly clean vdW contacts.

  1. Strong room-temperature negative transconductance in an axial Si/Ge hetero-nanowire tunneling field-effect transistor

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Le, Son T.; Hou, Xiaoxiao; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, S. T.

    2014-08-01

    We report on room-temperature negative transconductance (NTC) in axial Si/Ge hetero-nanowire tunneling field-effect transistors. The NTC produces a current peak-to-valley ratio >45, a high value for a Si-based device. We characterize the NTC over a range of gate VG and drain VD voltages, finding that NTC persists down to VD = -50 mV. The physical mechanism responsible for the NTC is the VG-induced depletion in the p-Ge section that eventually reduces the maximum electric field that triggers the tunneling ID, as confirmed via three-dimensional (3D) technology computer-aided design simulations.

  2. Adaptations of skeletal muscle mitochondria to exercise training.

    PubMed

    Lundby, Carsten; Jacobs, Robert A

    2016-01-01

    Mitochondrial volume density (Mito(VD)) is composed of two distinct mitochondrial subpopulations--intermyofibrillar mitochondria (Mito(IMF)) and subsarcolemmal mitochondria (Mito(SS)). With exercise training, Mito(VD) may increase by up to 40% and is, for the most part, related to an increase in Mito(IMF). Exercise-induced adaptations in mitochondrial function depend on the intensity of training and appear to be explained predominately by an increased expression of mitochondrial enzymes that facilitate aerobic metabolism. Although mitochondrial content often increases with training, it seems that mitochondrial adaptations are not needed to facilitate maximal oxygen uptake, whereas such adaptations are of greater importance for endurance capacity.

  3. Effect of Vitamin D3 Supplementation on Inflammatory Markers and Glycemic Measures among Overweight or Obese Adults: A Systematic Review of Randomized Controlled Trials

    PubMed Central

    Zuk, Aleksandra; Fitzpatrick, Tiffany; Rosella, Laura C.

    2016-01-01

    Background Obesity induced low-grade chronic inflammation disrupts proper immune and metabolic function. Vitamin D deficiency increases inflammation, which is associated with cardiometabolic risk. This systematic review examines the association between oral vitamin D (VD) supplementation and circulating inflammatory biomarkers and glycemic outcomes from randomized controlled trials (RCTs) of overweight and/or obese adults. Methods MEDLINE OVID, EMBASE and the Cochrane Central Register of Controlled Trials were searched according to a predefined protocol. Eligible RCTs included adults randomized to receive either oral VD or placebo. Two reviewers independently assessed RCTs for inclusion. Bias was assessed using the Cochrane Collaboration risk of bias tool. Mean differences were calculated comparing end-of-study sample means between the independent VD and placebo groups. Results Eleven unique RCTs met inclusion criteria from a total of 3,383 identified citations, including 79 screened articles and 14 full text data extractions. Inflammatory and glycemic measures were reported in 7 and 10 RCTs, respectively. Most trial findings were non-significant with considerable heterogeneity in design, participants and outcomes. All but one trial was rated as either high or unclear risk of bias. Two RCTs reported significant changes in inflammatory biomarkers; however, the mean difference between groups was not statistically significant: C-reactive protein 0.19 mg/L (p = 0.88); Tumor Necrosis Factor -0.54 pg/ml (p = 0.20). Two other trials found significant mean differences in fasting plasma glucose -0.32 mmol/L (p = 0.03), Hemoglobin A1c -0.13% (p = 0.04), and Homeostatic Model Assessment -0.86 (p = 0.02) following VD supplementation. Conclusions Overall, there is no clear established benefit of VD supplementation on inflammatory biomarkers among overweight/obese adults. Baseline serum VD possibly influences the effect of VD repletion on inflammatory markers. Risk of bias was

  4. Lennard-Jones parameters for small diameter carbon nanotubes and water for molecular mechanics simulations from van der Waals density functional calculations.

    PubMed

    Kaukonen, M; Gulans, A; Havu, P; Kauppinen, E

    2012-03-05

    Lennard-Jones (LJ) parameters are derived for classical nonpolarizable force fields for carbon nanotubes (CNTs) and for CNT-water interaction from van der Waals (vdW) enhanced density functional calculations. The new LJ parameters for carbon-carbon interactions are of the same order as those previously used in the literature but differ significantly for CNT-water interactions. This may partially originate from the fact that in addition to pure vdW interactions the polarization and other quantum mechanics effects are embedded into the LJ-potential.

  5. Influence of the van der Waals interaction in the dissociation dynamics of N{sub 2} on W(110) from first principles

    SciTech Connect

    Martin-Gondre, L.; Juaristi, J. I.; Blanco-Rey, M.; Díez Muiño, R.; Alducin, M.

    2015-02-21

    Using ab initio molecular dynamics (AIMD) calculations, we investigate the role of the van der Waals (vdW) interaction in the dissociative adsorption of N{sub 2} on W(110). Hitherto, existing classical dynamics calculations performed on six-dimensional potential energy surfaces based on density functional theory (DFT), and the semi-local PW91 and RPBE [Hammer et al. Phys. Rev. B 59, 7413 (1999)] exchange-correlation functionals were unable to fully describe the dependence of the initial sticking coefficient on the molecular beam incidence conditions as found in experiments. N{sub 2} dissociation on W(110) was shown to be very sensitive not only to short molecule-surface distances but also to large distances where the vdW interaction, not included in semilocal-DFT, should dominate. In this work, we perform a systematic study on the dissociative adsorption using a selection of existing non-local functionals that include the vdW interaction (vdW-functionals). Clearly, the inclusion of the non-local correlation term contributes in all cases to correct the unrealistic energy barriers that were identified in the RPBE at large molecule-surface distances. Among the tested vdW-functionals, the original vdW-DF by Dion et al. [Phys. Rev. Lett. 92, 246401 (2004)] and the ulterior vdW-DF2 give also an adequate description of the N{sub 2} adsorption energy and energy barrier at the transition state, i.e., of the properties that are commonly used to verify the quality of any exchange-correlation functional. However, the results of our AIMD calculations, which are performed at different incidence conditions and hence extensively probe the multi-configurational potential energy surface of the system, do not seem as satisfactory as the preliminary static analysis suggested. When comparing the obtained dissociation probabilities with existing experimental data, none of the used vdW-functionals seems to provide altogether an adequate description of the N{sub 2}/W(110) interaction at

  6. Data-Driven Property Estimation for Protective Clothing

    DTIC Science & Technology

    2014-09-01

    CV1 VD x C CV1 VD dt dh          hx  ses CC  seC     se2sesese aln11ln  ssese VC sss VC .1ase  1ase  0ase  0Csese...The governing equations and the external boundary condition (Eqs. 32 to 35) change accordingly: (40) (41)   sss VC

  7. Structure and energetics of azobenzene on Ag(111): benchmarking semiempirical dispersion correction approaches.

    PubMed

    Mercurio, G; McNellis, E R; Martin, I; Hagen, S; Leyssner, F; Soubatch, S; Meyer, J; Wolf, M; Tegeder, P; Tautz, F S; Reuter, K

    2010-01-22

    We employ normal-incidence x-ray standing wave and temperature programed desorption spectroscopy to derive the adsorption geometry and energetics of the prototypical molecular switch azobenzene at Ag(111). This allows us to assess the accuracy of semiempirical correction schemes as a computationally efficient means to overcome the deficiency of semilocal density-functional theory with respect to long-range van der Waals (vdW) interactions. The obtained agreement underscores the significant improvement provided by the account of vdW interactions, with remaining differences mainly attributed to the neglect of electronic screening at the metallic surface.

  8. The Anomalous Effect of Interface Traps on Generation Current in Lightly Doped Drain nMOSFET's

    NASA Astrophysics Data System (ADS)

    Ma, Xiao-Hua; Gao, Hai-Xia; Cao, Yan-Rong; Chen, Hai-Feng; Hao, Yue

    2010-05-01

    The anomalous phenomenon of generation current IGD in the lightly doped drain (LDD) nMOSFET measured under the drain bias VD-step mode is reported. We propose an assumption of activated (A) and frozen (F) traps for the VD-step mode: The A traps contributes to IGD while the F process can make them lose the roles as generation centers. The A and F regions can form the F-A region. The comparison of the F and A regions decides the role of the F-A region. The experiments confirm the assumption.

  9. Constraints on the Interstellar Dust Flux Based on Stardust at Home Search Results

    NASA Technical Reports Server (NTRS)

    Zolensky, Michael E.; Westphal, J.; Allen, C.; Anderson, D.; Bajt, S.; Bechtel, H. A.; Borg, J.; Brenker, F.; Bridges, J.; Brownlee, D. E.; Burchell, M.

    2011-01-01

    Recent advances in active particle selection in the Heidelberg Van de r Graaf (VdG) dust accelerator have led to high-fidelity, low-backgro und calibrations of track sizes in aerogel as a function of particle size and velocity in the difficult regime above 10 km sec..1 and sub micron sizes. To the extent that the VdG shots are analogs for inters tellar dust (ISD) impacts, these new measurements enable us to place preliminary constraints on the ISD flux based on Stardust@home data.

  10. Interactions between surface discharges induced by volume discharges in a dielectric barrier discharge system

    SciTech Connect

    Gao, Yenan; Dong, Lifang Zhao, Longhu; Wang, Yongjie; Pan, Yuyang; Li, Ben

    2014-10-15

    The interaction between micro-discharges involved in surface discharges (SDs) is studied in dielectric barrier discharge system. Instantaneous images taken by high speed cameras show that the SDs are induced by volume discharges (VDs). They cannot cross the midperpendicular of two neighbouring volume charges at low voltage while they stretch along it at high voltage, indicating that there is interaction between SDs. The differences of plasma parameters between SD and VD are studied by optical emission spectroscopy. The simulation of the electric fields of the wall charges accumulated by VD further confirms the existence of the interaction.

  11. Mycorrhizal symbiosis and local adaptation in Aster amellus: a field transplant experiment.

    PubMed

    Pánková, Hana; Raabová, Jana; Münzbergová, Zuzana

    2014-01-01

    Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K) and Ceske Stredohori (region S). Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S) in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local adaptation studies

  12. How to Communicate Near Earth Objects with the Public - Klet Observatory Experience

    NASA Astrophysics Data System (ADS)

    Ticha, Jana; Tichy, Milos; Kocer, Michal

    2015-08-01

    Near-Earth Object (NEO) research is counted among the most popular parts of communicating astronomy with the public. Increasing research results in the field of Near-Earth Objects as well as impact hazard investigations cause growing interest among general public and media. Furthermore NEO related issues have outstanding educational value. So thus communicating NEO detection, NEO characterization, possible impact effects, space missions to NEOs, ways of mitigation and impact warnings with the public and media belong to the most important tasks of scientists and research institutions.Our institution represents an unique liaison of the small professional research institution devoted especially to NEO studies (the Klet Observatory, Czech Republic) and the educational and public outreach branch (the Observatory and Planetarium Ceske Budejovice, Czech Republic). This all has been giving us an excellent opportunity for bringing NEO information to wider audience. We have been obtaining a wide experience in communicating NEOs with the public more than twenty years.There is a wide spectrum of public outreach tools aimed to NEO research and hazard. As the most useful ones we consider two special on-line magazines (e-zins) devoted to asteroids (www.planetky.cz) and comets (www.komety.cz) in Czech language, educational multimedia presentations for schools at different levels in planetarium, summer excursions for wide public just at the Klet Observatory on the top of the Klet mountain, public lectures, meetings and exhibitions. It seems to be very contributing and favoured by public to have opportunities for more or less informal meetings just with NEO researchers from time to time. Very important part of NEO public outreach consists of continuous contact with journalists and media including press releases, interviews, news, periodical programs. An increasing role of social media is taken into account through Facebook and Twitter profiles.The essential goal of all mentioned NEO

  13. Mycorrhizal Symbiosis and Local Adaptation in Aster amellus: A Field Transplant Experiment

    PubMed Central

    Pánková, Hana; Raabová, Jana; Münzbergová, Zuzana

    2014-01-01

    Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K) and Ceske Stredohori (region S). Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S) in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local adaptation studies

  14. Elements of Vortex-Dipole Dynamics in a Nonuniform Bose-Einstein Condensate

    NASA Astrophysics Data System (ADS)

    Sakhel, Roger R.; Sakhel, Asaad R.

    2016-09-01

    The elements of the vortex-dipole (VD) dynamics are numerically examined in a nonuniform Bose-Einstein condensate (BEC) using the time-dependent Gross-Pitaevskii equation that is solved by the split-step Crank-Nicolson method in real time. The BEC is trapped in a harmonic potential, surrounded by a hard-wall box potential, and stirred by an attractive focusing laser. In this regard, we particularly refer to a recent examination by Aioi et al. (Phys. Rev. X, 1: 021003, 2011) who presented controlled VD generation using a red laser in an infinite homogeneous BEC for comparison. It is found that the dynamics in the present nonuniform BEC is quite different from the one reported earlier by Aioi et al. The elements considered are the phase maps that demonstrate the presence of phase rings, the effects of the coupling constant on the vortex lifetime, the density at the vortex core, and the heating effects of the stirrer. Upon a suitable choice of coupling for our system, a VD generated by the moving fragment is transferred to and trapped by the central BEC cloud. The latter serves as a dissipationless vortex respository, where the lifetime of the VD is extended on demand. An analytical model is presented that qualitatively reproduces the wavefunction with its principle features and provides details inaccessible by the present numerical method such as the coupling between stirrer and BEC.

  15. VOLATILE ORGANO-METALLOIDS IN BIO-SOLID MATERIALS: ANALYSIS BY VACUUM DISTILLATION-GC/MS

    EPA Science Inventory

    An analytical method based on vacuum distillation-gas chromatography-mass spectrometry (VD-GC-MS)

    was developed for determining volatile organo-metalloid contaminants in bio-solid materials. Method

    performance was evaluated for dimethylselenide (DMSe), dimethyldisel...

  16. Toward a Systematic Evaluation of Vowel Target Events across Speech Tasks

    ERIC Educational Resources Information Center

    Kuo, Christina

    2011-01-01

    The core objective of this study was to examine whether acoustic variability of vowel production in American English, across speaking tasks, is systematic. Ten male speakers who spoke a relatively homogeneous Wisconsin dialect produced eight monophthong vowels (in hVd and CVC contexts) in four speaking tasks, including clear-speech, citation form,…

  17. Cerebral Hemodynamics and Cognitive Function in Cirrhotic Patients with Hepatic Encephalopathy

    PubMed Central

    Zhou, Yuqing; Dong, Qian; Zhang, Rong; Zhou, Shunfeng; Li, Linqiang; Cheng, Keran; Kong, Rui; Yu, Qiang; Xu, Shizan; Li, Jingjing; Li, Sainan; Feng, Jiao; Wu, Liwei; Liu, Tong; Lu, Xiya; Xia, Yujing

    2016-01-01

    Aims. To investigate cerebral hemodynamics in cirrhotic patients with HE and to observe effects of treatment in cerebral hemodynamics and correlations among ammonia, cerebral hemodynamics, and cognitive function. Methods. There were four groups: healthy controls (group 1), cirrhosis without HE (group 2), cirrhosis with MHE (group 3), and cirrhosis with OHE (group 4). Ammonia and cerebral hemodynamics (by TCD) were assessed. Patients in group 3 were subsequently randomized to two subgroups: the control (group A) and the treated (group B, treated with lactulose for two months), and they were retested for ammonia and TCD after treatment. Results. Ammonia, Vm, Vd, PI, and RI were statistically different before treatment, and ammonia, PI, and RI levels paralleled the severity of HE (P < 0.05). In group B, Vd increased and ammonia, PI, and RI declined following treatment (P < 0.05), while there were no differences in group A (P > 0.05). Correlations were found between ammonia and Vd, PI, RI, NCT-A, and DST and also found between Vd, PI, RI, and NCT-A and DST (P < 0.05). Conclusions. This study revealed that cerebral hemodynamics were related to the severity of HE and cerebral autoregulation was impaired. There were tight correlations among ammonia, cerebral hemodynamics, and cognitive function, and, following treatment, cerebral hemodynamics improved. PMID:28096811

  18. van der Waals density functionals built upon the electron-gas tradition: Facing the challenge of competing interactions

    SciTech Connect

    Berland, Kristian; Arter, Calvin A.; Thonhauser, T.; Cooper, Valentino R.; Lee, Kyuho; Lundqvist, Bengt I.; Schröder, Elsebeth; Hyldgaard, Per

    2014-05-14

    The theoretical description of sparse matter attracts much interest, in particular for those ground-state properties that can be described by density functional theory. One proposed approach, the van der Waals density functional (vdW-DF) method, rests on strong physical foundations and offers simple yet accurate and robust functionals. A very recent functional within this method called vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B 89, 035412 (2014)] stands out in its attempt to use an exchange energy derived from the same plasmon-based theory from which the nonlocal correlation energy was derived. Encouraged by its good performance for solids, layered materials, and aromatic molecules, we apply it to several systems that are characterized by competing interactions. These include the ferroelectric response in PbTiO{sub 3}, the adsorption of small molecules within metal-organic frameworks, the graphite/diamond phase transition, and the adsorption of an aromatic-molecule on the Ag(111) surface. Our results indicate that vdW-DF-cx is overall well suited to tackle these challenging systems. In addition to being a competitive density functional for sparse matter, the vdW-DF-cx construction presents a more robust general-purpose functional that could be applied to a range of materials problems with a variety of competing interactions.

  19. van der Waals density functionals built upon the electron-gas tradition: Facing the challenge of competing interactions

    SciTech Connect

    Berland, Kristian; Arter, Calvin A; Cooper, Valentino R; Lee, Dr. Kyuho; Lundqvist, Prof. Bengt I.; Schroder, Prof. Elsebeth; Thonhauser, Prof. Timo; Hyldgaard, Per

    2014-01-01

    The theoretical description of sparse matter attracts much interest, in particular for those groundstate properties that can be described by density functional theory (DFT). One proposed approach, the van der Waals density functional (vdW-DF) method, rests on strong physical foundations and offers simple yet accurate and robust functionals. A very recent functional within this method called vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B, in print] stands out in its attempt to use an exchange energy derived from the same plasmon-based theory from which the nonlocal correlation energy was derived. Encouraged by its good performance for solids, layered materials, and aromatic molecules, we apply it to several systems that are characterized by competing interactions. These include the ferroelectric response in PbTiO3, the adsorption of small molecules within metal-organic frameworks (MOFs), the graphite/diamond phase transition, and the adsorption of an aromaticmolecule on the Ag(111) surface. Our results indicate that vdW-DF-cx is overall well suited to tackle these challenging systems. In addition to being a competitive density functional for sparse matter, the vdW-DF-cx construction presents a more robust general purpose functional that could be applied to a range of materials problems with a variety of competing interactions.

  20. Electronic Communication in Covalently vs. Non-Covalently Bonded Polyfluorene Systems: the Role of the Covalent Linker.

    NASA Astrophysics Data System (ADS)

    Uhler, Brandon; Reilly, Neil J.; Talipov, Marat R.; Ivanov, Maxim; Timerghazin, Qadir; Rathore, Rajendra; Reid, Scott

    2015-06-01

    The covalently linked polyfluorene molecules F1-F6 (see left) are prototypical molecular wires by virtue of their favorable electron/hole transport properties brought about by π-stacking. To understand the role of the covalent linker in facilitating electron transport in these systems, we have investigated several van der Waals (vdW) analogues by resonant mass spectroscopy. Electronic spectra and ion yield curves are reported for jet-cooled vdW clusters containing up to six fluorene units. The near-coincidence of the electronic band origins for the dimer and larger clusters suggests that a structure containing a central dimer chromophore is the predominant conformational motif. As for F1-F6, the threshold ionization potentials extracted from the ion yield measurements decrease linearly with inverse cluster size. Importantly, however, the rate of decrease is significantly smaller in the vdW clusters, indicating more efficient hole stabilization in the covalently bound systems. Results for similar vdW clusters that are locked into specific conformations by steric effects will also be reported.

  1. Polymorphism and Elastic Response of Molecular Materials from First Principles: How Hard Can it Be?

    NASA Astrophysics Data System (ADS)

    Reilly, Anthony; Tkatchenko, Alexandre

    2014-03-01

    Molecular materials are of great fundamental and applied importance in science and industry, with numerous applications in pharmaceuticals, electronics, sensing, and catalysis. A key challenge for theory has been the prediction of their stability, polymorphism and response to perturbations. While pairwise models of van der Waals (vdW) interactions have improved the ability of density functional theory (DFT) to model these systems, substantial quantitative and even qualitative failures remain. In this contribution we show how a many-body description of vdW interactions can dramatically improve the accuracy of DFT for molecular materials, yielding quantitative description of stabilities and polymorphism for these challenging systems. Moreover, the role of many-body vdW interactions goes beyond stabilities to response properties. In particular, we have studied the elastic properties of a series of molecular crystals, finding that many-body vdW interactions can account for up to 30% of the elastic response, leading to quantitative and qualitative changes in elastic behavior. We will illustrate these crucial effects with the challenging case of the polymorphs of aspirin, leading to a better understanding of the conflicting experimental and theoretical studies of this system.

  2. Diffuse-interface modeling of liquid-vapor coexistence in equilibrium drops using smoothed particle hydrodynamics.

    PubMed

    Sigalotti, Leonardo Di G; Troconis, Jorge; Sira, Eloy; Peña-Polo, Franklin; Klapp, Jaime

    2014-07-01

    We study numerically liquid-vapor phase separation in two-dimensional, nonisothermal, van der Waals (vdW) liquid drops using the method of smoothed particle hydrodynamics (SPH). In contrast to previous SPH simulations of drop formation, our approach is fully adaptive and follows the diffuse-interface model for a single-component fluid, where a reversible, capillary (Korteweg) force is added to the equations of motion to model the rapid but smooth transition of physical quantities through the interface separating the bulk phases. Surface tension arises naturally from the cohesive part of the vdW equation of state and the capillary forces. The drop models all start from a square-shaped liquid and spinodal decomposition is investigated for a range of initial densities and temperatures. The simulations predict the formation of stable, subcritical liquid drops with a vapor atmosphere, with the densities and temperatures of coexisting liquid and vapor in the vdW phase diagram closely matching the binodal curve. We find that the values of surface tension, as determined from the Young-Laplace equation, are in good agreement with the results of independent numerical simulations and experimental data. The models also predict the increase of the vapor pressure with temperature and the fitting to the numerical data reproduces very well the Clausius-Clapeyron relation, thus allowing for the calculation of the vaporization pressure for this vdW fluid.

  3. van der Waals forces and electron-electron interactions in two strained graphene layers

    NASA Astrophysics Data System (ADS)

    Sharma, Anand; Harnish, Peter; Sylvester, Alexander; Kotov, Valeri N.; Neto, A. H. Castro

    2014-06-01

    We evaluate the van der Waals (vdW) interaction energy at zero temperature between two undoped strained graphene layers separated by a finite distance. We consider the following three models for the anisotropic case: (a) where one of the two layers is uniaxially strained, (b) the two layers are strained in the same direction, and (c) one of the layers is strained in the perpendicular direction with respect to the other. We find that for all three models and given value of the electron-electron interaction coupling, the vdW interaction energy increases with increasing anisotropy. The effect is most striking for the case when both layers are strained in the same direction where we observe up to an order of magnitude increase in the strained relative to the unstrained case. We also investigate the effect of electron-electron interaction renormalization in the region of large separation between the strained graphene layers. We find that the many-body renormalization contributions to the correlation energy are non-negligible and the vdW interaction energy decreases as a function of increasing distance between the layers due to renormalization of the Fermi velocity, the anisotropy, and the effective interaction. Our analysis can be useful in designing graphene-based vdW heterostructures which, in recent times, has seen an upsurge in research activity.

  4. Scaling Laws for van der Waals Interactions in Nanostructured Materials

    NASA Astrophysics Data System (ADS)

    Gobre, Vivekanand; Tkatchenko, Alexandre

    2014-03-01

    Van der Waals (vdW) forces originate from interactions between fluctuating multipoles in matter and play a significant role in the structure and stability of nanostructured materials. Many models used to describe vdW interactions in nanomaterials are based on a simple pairwise-additive approximation, neglecting the strong electrodynamic response effects caused by long-range fluctuations in matter. We develop and utilize an efficient microscopic method to demonstrate that vdW interactions in nanomaterials act at distances greater than typically assumed, and can be characterized by different scaling laws depending on the dimensionality and size of the system. Specifically, we study the behaviour of vdW interactions in single-layer and multilayer graphene, fullerenes of varying size, single-wall carbon nanotubes and graphene nanoribbons. As a function of nanostructure size, the van der Waals coefficients follow unusual trends for all of the considered systems, and deviate significantly from the conventionally employed pairwise-additive picture. We propose that the peculiar van der Waals interactions in nanostructured materials could be exploited to control their self-assembly.

  5. Van der Waals Effects on semiconductor clusters.

    PubMed

    Li, Haisheng; Chen, Weiguang; Han, Xiaoyu; Li, Liben; Sun, Qiang; Guo, Zhengxiao; Jia, Yu

    2015-09-30

    Van der Waals (vdW) interactions play an important role on semiconductors in nanoscale. Here, we utilized first-principles calculations based on density functional theory to demonstrate the growth mode transition from prolate to multiunit configurations for Gen (n = 10-50) clusters. In agreement with the injected ion drift tube techniques that "clusters with n < 70 can be thought of as loosely bound assemblies of small strongly bound fragments (such as Ge7 and Ge10 )," we found these stable fragments are connected by Ge6 , Ge9 , or Ge10 unit (from bulk diamond), via strong covalent bonds. Our calculated cations usually fragment to Ge7 and Ge10 clusters, in accordance with the experiment results that the spectra Ge7 and Ge10 correspond to the mass abundance spectra. By controlling a germanium cluster with vdW interactions parameters in the program or not, we found that the vdW effects strengthen the covalent bond from different units more strikingly than that in a single unit. With more bonds between units than the threadlike structures, the multiunit structures have larger vdW energies, explaining why the isolated nanowires are harder to produce. © 2015 Wiley Periodicals, Inc.

  6. How van der Waals interactions determine the unique properties of water.

    PubMed

    Morawietz, Tobias; Singraber, Andreas; Dellago, Christoph; Behler, Jörg

    2016-07-26

    Whereas the interactions between water molecules are dominated by strongly directional hydrogen bonds (HBs), it was recently proposed that relatively weak, isotropic van der Waals (vdW) forces are essential for understanding the properties of liquid water and ice. This insight was derived from ab initio computer simulations, which provide an unbiased description of water at the atomic level and yield information on the underlying molecular forces. However, the high computational cost of such simulations prevents the systematic investigation of the influence of vdW forces on the thermodynamic anomalies of water. Here, we develop efficient ab initio-quality neural network potentials and use them to demonstrate that vdW interactions are crucial for the formation of water's density maximum and its negative volume of melting. Both phenomena can be explained by the flexibility of the HB network, which is the result of a delicate balance of weak vdW forces, causing, e.g., a pronounced expansion of the second solvation shell upon cooling that induces the density maximum.

  7. Dispersion interactions in Density Functional Theory

    NASA Astrophysics Data System (ADS)

    Andrinopoulos, Lampros; Hine, Nicholas; Mostofi, Arash

    2012-02-01

    Semilocal functionals in Density Functional Theory (DFT) achieve high accuracy simulating a wide range of systems, but miss the effect of dispersion (vdW) interactions, important in weakly bound systems. We study two different methods to include vdW in DFT: First, we investigate a recent approach [1] to evaluate the vdW contribution to the total energy using maximally-localized Wannier functions. Using a set of simple dimers, we show that it has a number of shortcomings that hamper its predictive power; we then develop and implement a series of improvements [2] and obtain binding energies and equilibrium geometries in closer agreement to quantum-chemical coupled-cluster calculations. Second, we implement the vdW-DF functional [3], using Soler's method [4], within ONETEP [5], a linear-scaling DFT code, and apply it to a range of systems. This method within a linear-scaling DFT code allows the simulation of weakly bound systems of larger scale, such as organic/inorganic interfaces, biological systems and implicit solvation models. [1] P. Silvestrelli, JPC A 113, 5224 (2009). [2] L. Andrinopoulos et al, JCP 135, 154105 (2011). [3] M. Dion et al, PRL 92, 246401 (2004). [4] G. Rom'an-P'erez, J.M. Soler, PRL 103, 096102 (2009). [5] C. Skylaris et al, JCP 122, 084119 (2005).

  8. Teaching About Sexually Transmitted Diseases; A Curriculum Guide and Resources For Grades 7-12.

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    This curriculum guide provides school districts that already have VD education programs with up-to-date information about research and epidemiology relating to sexually transmitted diseases. For districts wishing to implement a program for the first time, it offers both a structured framework and the resources and materials needed for a complete…

  9. Multichannel Compression: Effects of Reduced Spectral Contrast on Vowel Identification

    ERIC Educational Resources Information Center

    Bor, Stephanie; Souza, Pamela; Wright, Richard

    2008-01-01

    Purpose: To clarify if large numbers of wide dynamic range compression channels provide advantages for vowel identification and to measure its acoustic effects. Methods: Eight vowels produced by 12 talkers in the /hVd/ context were compressed using 1, 2, 4, 8, and 16 channels. Formant contrast indices (mean formant peak minus mean formant trough;…

  10. Estrogen has opposing effects on vascular reactivity in obese, insulin-resistant male Zucker rats

    NASA Technical Reports Server (NTRS)

    Brooks-Asplund, Esther M.; Shoukas, Artin A.; Kim, Soon-Yul; Burke, Sean A.; Berkowitz, Dan E.

    2002-01-01

    We hypothesized that estradiol treatment would improve vascular dysfunction commonly associated with obesity, hyperlipidemia, and insulin resistance. A sham operation or 17beta-estradiol pellet implantation was performed in male lean and obese Zucker rats. Maximal vasoconstriction (VC) to phenylephrine (PE) and potassium chloride was exaggerated in control obese rats compared with lean rats, but estradiol significantly attenuated VC in the obese rats. Estradiol reduced the PE EC50 in all groups. This effect was cyclooxygenase independent, because preincubation with indomethacin reduced VC response to PE similarly in a subset of control and estrogen-treated lean rats. Endothelium-independent vasodilation (VD) to sodium nitroprusside was similar among groups, but endothelium-dependent VD to ACh was significantly impaired in obese compared with lean rats. Estradiol improved VD in lean and obese rats by decreasing EC50 but impaired function by decreasing maximal VD. The shift in EC50 corresponded to an upregulation in nitric oxide synthase III protein expression in the aorta of the estrogen-treated obese rats. In summary, estrogen treatment improves vascular function in male insulin-resistant, obese rats, partially via an upregulation of nitric oxide synthase III protein expression. These effects are counteracted by adverse factors, such as hyperlipidemia and, potentially, a release of an endothelium-derived contractile agent.

  11. Effect of chia seed meal on baking quality of cakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chia seed is a good source of dietary fiber and complete proteins; chia seeds contain many health-promoting compounds and can be incorporated into baking goods for high-protein, high-fiber diet. Food grade chia seeds were obtained from a local grocery store and ground into meal using Retsch Model VD...

  12. Persistent photoconductivity in two-dimensional Mo1-xW xSe2–MoSe2 van der Waals heterojunctions

    DOE PAGES

    Puretzky, Alexander A.; Basile, Leonardo; Idrobo, Juan Carlos; ...

    2016-02-16

    Van der Waals (vdW) heterojunctions consisting of vertically-stacked individual or multiple layers of two-dimensional (2D) layered semiconductors, especially the transition metal dichalcogenides (TMDs), are fascinating new artificial solids just nanometers-thin that promise novel optoelectronic functionalities due to the sensitivity of their electronic and optical properties to strong quantum confinement and interfacial interactions. Here, monolayers of n-type MoSe2 and p-type Mo1-xW xSe2–MoSe2 are grown by vapor transport methods, then transferred and stamped to form artificial vdW heterostructures with different interlayer orientations. Atomic-resolution Z-contrast electron microscopy and electron diffraction are used to characterize both the individual monolayers and the atomic registry betweenmore » layers in the bilayer vdW heterostructures. These measurements are compared with photoluminescence and low-frequency Raman spectroscopy, which indicates strong interlayer coupling in heterostructures. Remarkably, the heterojunctions exhibit an unprecedented photoconductivity effect that persists at room temperature for several days. This persistent photoconductivity is shown to be tunable by applying a gate bias that equilibrates the charge distribution. Furthermore, these measurements indicate that such ultrathin vdW heterojunctions can function as rewritable optoelectronic switches or memory elements under time-dependent photo-illumination, an effect which appears promising for new monolayer TMDs-based optoelectronic devices applications.« less

  13. Persistent photoconductivity in two-dimensional Mo1-xW xSe2–MoSe2 van der Waals heterojunctions

    SciTech Connect

    Puretzky, Alexander A.; Basile, Leonardo; Idrobo, Juan Carlos; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai; Li, Xufan; Lin, Ming -Wei; Wang, Kei

    2016-02-16

    Van der Waals (vdW) heterojunctions consisting of vertically-stacked individual or multiple layers of two-dimensional (2D) layered semiconductors, especially the transition metal dichalcogenides (TMDs), are fascinating new artificial solids just nanometers-thin that promise novel optoelectronic functionalities due to the sensitivity of their electronic and optical properties to strong quantum confinement and interfacial interactions. Here, monolayers of n-type MoSe2 and p-type Mo1-xW xSe2–MoSe2 are grown by vapor transport methods, then transferred and stamped to form artificial vdW heterostructures with different interlayer orientations. Atomic-resolution Z-contrast electron microscopy and electron diffraction are used to characterize both the individual monolayers and the atomic registry between layers in the bilayer vdW heterostructures. These measurements are compared with photoluminescence and low-frequency Raman spectroscopy, which indicates strong interlayer coupling in heterostructures. Remarkably, the heterojunctions exhibit an unprecedented photoconductivity effect that persists at room temperature for several days. This persistent photoconductivity is shown to be tunable by applying a gate bias that equilibrates the charge distribution. Furthermore, these measurements indicate that such ultrathin vdW heterojunctions can function as rewritable optoelectronic switches or memory elements under time-dependent photo-illumination, an effect which appears promising for new monolayer TMDs-based optoelectronic devices applications.

  14. The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals

    NASA Astrophysics Data System (ADS)

    Mudd, G. W.; Molas, M. R.; Chen, X.; Zólyomi, V.; Nogajewski, K.; Kudrynskyi, Z. R.; Kovalyuk, Z. D.; Yusa, G.; Makarovsky, O.; Eaves, L.; Potemski, M.; Fal’Ko, V. I.; Patanè, A.

    2016-12-01

    The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to the family of vdW layered crystals, which transforms from a direct to an indirect band gap semiconductor as the number of layers is reduced. We investigate this direct-to-indirect bandgap crossover, demonstrate a highly tuneable optical response from the near infrared to the visible spectrum with decreasing layer thickness down to 2 layers, and report quantum dot-like optical emissions distributed over a wide range of energy. Our analysis also indicates that electron and exciton effective masses are weakly dependent on the layer thickness and are significantly smaller than in other vdW crystals. These properties are unprecedented within the large family of vdW crystals and demonstrate the potential of InSe for electronic and photonic technologies.

  15. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor

    PubMed Central

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations. PMID:26322058

  16. Interannual variability in ozone removal by a temperate deciduous forest

    NASA Astrophysics Data System (ADS)

    Clifton, O. E.; Fiore, A. M.; Munger, J. W.; Malyshev, S.; Horowitz, L. W.; Shevliakova, E.; Paulot, F.; Murray, L. T.; Griffin, K. L.

    2017-01-01

    The ozone (O3) dry depositional sink and its contribution to observed variability in tropospheric O3 are both poorly understood. Distinguishing O3 uptake through plant stomata versus other pathways is relevant for quantifying the O3 influence on carbon and water cycles. We use a decade of O3, carbon, and energy eddy covariance (EC) fluxes at Harvard Forest to investigate interannual variability (IAV) in O3 deposition velocities (vd,O3). In each month, monthly mean vd,O3 for the highest year is twice that for the lowest. Two independent stomatal conductance estimates, based on either water vapor EC or gross primary productivity, vary little from year to year relative to canopy conductance. We conclude that nonstomatal deposition controls the substantial observed IAV in summertime vd,O3 during the 1990s over this deciduous forest. The absence of obvious relationships between meteorology and vd,O3 implies a need for additional long-term, high-quality measurements and further investigation of nonstomatal mechanisms.

  17. Conserved molecular mechanisms underlying the effects of small molecule xenobiotic chemotherapeutics on cells

    PubMed Central

    SARIN, HEMANT

    2016-01-01

    For proper determination of the apoptotic potential of chemoxenobiotics in synergism, it is important to understand the modes, levels and character of interactions of chemoxenobiotics with cells in the context of predicted conserved biophysical properties. Chemoxenobiotic structures are studied with respect to atom distribution over molecular space, the predicted overall octanol-to-water partition coefficient (Log OWPC; unitless) and molecular size viz a viz van der Waals diameter (vdWD). The Log OWPC-to-vdWD (nm−1) parameter is determined, and where applicable, hydrophilic interacting moiety/core-to-vdWD (nm−1) and lipophilic incorporating hydrophobic moiety/core-to-vdWD (nm−1) parameters of their part-structures are determined. The cellular and sub-cellular level interactions of the spectrum of xenobiotic chemotherapies have been characterized, for which a classification system has been developed based on predicted conserved biophysical properties with respect to the mode of chemotherapeutic effect. The findings of this study are applicable towards improving the effectiveness of existing combination chemotherapy regimens and the predictive accuracy of personalized cancer treatment algorithms as well as towards the selection of appropriate novel xenobiotics with the potential to be potent chemotherapeutics for dendrimer nanoparticle-based effective transvascular delivery. PMID:26998284

  18. 40 CFR 63.11562 - What are my initial compliance requirements?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... production rate or asphalt charging rate over the duration of the test, Mg/hr (ton/hr). K = conversion factor... assumptions used to calculate the process emission rate that demonstrate compliance with the emission limits... following equations to calculate the asphalt charging rate (P). (i) P = (Vd)/(K′ Θ) Where: P =...

  19. The non-structural protein NS-2 of Bombyx mori parvo-like virus is localized to the nuclear membrane.

    PubMed

    Wang, Fenghua; Hu, Zhaoyang; He, Yuanqing; Li, Guohui; Kong, Jie; Cao, Jian; Chen, Keping; Yao, Qin

    2011-07-01

    Bombyx mori parvo-like virus (BmPLV) has two complementary single-stranded DNA genome (VD1 and VD2) and owns a self-encoding DNA polymerase motif, but its replication mechanism is unclear. In our previous research, a protein encoded by VD1-ORF1 was indentified in the midgut of BmPLV China Zhenjiang isolate-(BmPLV-Z) infected silkworm larvae via two-dimensional gel electrophoresis (2-DE). This protein was named as non-structural protein 2 (NS2), which showed no similarity to that of parvoviruses. To date, little is known about it. In this study, sequence alignment results showed that NS2 shared homology with some chromosomal replication initiator protein dnaA and DNA-binding response regulators. The ns2 was cloned and expressed in E. coli, and then a polyclonal antibody of the NS2 protein was prepared successfully. The data from real-time quantitative PCR displayed that the transcription of VD1-ORF1 from BmPLV-Z-infected midguts started from 28-h post inoculation (h p.i.) in low amounts, but in high amounts at late stages of infection. Immunofluorescence showed that NS2 ultimately concentrated on the nuclear membrane in BmN cells at late stages, indicating that NS2 might be associated with integral membrane protein.

  20. Transposable elements in phytopathogenic Verticillium spp.: insights into genome evolution and inter- and intra-specific diversification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium dahliae (Vd) and Verticillium albo-atrum (Va) are cosmopolitan soil fungi causing very disruptive vascular diseases on a wide range of crop plants. To date, no sexual stage has been identified in either microorganism suggesting that somatic mutation is a major force in generating geneti...

  1. Noninvasive Optical Imaging of UV-Induced Squamous Cell Carcinoma in Murine Skin: Studies of Early Tumor Development and Vitamin D Enhancement of Protoporphyrin IX Production

    PubMed Central

    Rollakanti, Kishore R.; Anand, Sanjay; Davis, Scott C.; Pogue, Brian W.; Maytin, Edward V.

    2015-01-01

    Better noninvasive techniques are needed to monitor protoporphyrin IX (PpIX) levels before and during photodynamic therapy (PDT) of squamous cell carcinoma (SCC) of the skin. Our aim was to evaluate: (1) multispectral fluorescent imaging of ultraviolet light (UV)-induced cancer and precancer in a mouse model of SCC; (2) multispectral imaging and probe-based fluorescence detection as a tool to study Vitamin D (VD) effects on aminolevulinic acid (ALA)-induced PpIX synthesis. Dorsal skin of hairless mice was imaged weekly during a 24-week UV carcinogenesis protocol. Hot spots of PpIX fluorescence were detectable by multispectral imaging beginning at 14 weeks of UV exposure. Many hot spots disappeared after cessation of UV at week 20, but others persisted or became visible after week 20, and corresponded to tumors that eventually became visible by eye. In SCC-bearing mice pretreated with topical VD before ALA application, our optical techniques confirmed that VD preconditioning induces a tumor-selective increase in PpIX levels. Fluorescence-based optical imaging of PpIX is a promising tool for detecting early SCC lesions of the skin. Pretreatment with VD can increase the ability to detect early tumors, providing a potential new way to improve efficacy of ALA-PDT. PMID:26223149

  2. Fabrication of WS2/GaN p-n Junction by Wafer-Scale WS2 Thin Film Transfer

    PubMed Central

    Yu, Yang; Fong, Patrick W. K.; Wang, Shifeng; Surya, Charles

    2016-01-01

    High quality wafer-scale free-standing WS2 grown by van der Waals rheotaxy (vdWR) using Ni as a texture promoting layer is reported. The microstructure of vdWR grown WS2 was significantly modified from mixture of crystallites with their c-axes both parallel to (type I) and perpendicular to (type II) the substrate to large type II crystallites. Wafer-scale transfer of vdWR grown WS2 onto different substrates by an etching-free technique was demonstrated for the first time that utilized the hydrophobic property of WS2 and hydrophilic property of sapphire. Our results show that vdWR is a reliable technique to obtain type-II textured crystallites in WS2, which is the key factor for the wafer-scale etching-free transfer. The transferred films were found to be free of observable wrinkles, cracks, or polymer residues. High quality p-n junctions fabricated by room-temperature transfer of the p-type WS2 onto an n-type GaN was demonstrated with a small leakage current density of 29.6 μA/cm2 at −1 V which shows superior performances compared to the directly grown WS2/GaN heterojunctions. PMID:27897210

  3. Esaki Diodes in van der Waals Heterojunctions with Broken-Gap Energy Band Alignment.

    PubMed

    Yan, Rusen; Fathipour, Sara; Han, Yimo; Song, Bo; Xiao, Shudong; Li, Mingda; Ma, Nan; Protasenko, Vladimir; Muller, David A; Jena, Debdeep; Xing, Huili Grace

    2015-09-09

    van der Waals (vdW) heterojunctions composed of two-dimensional (2D) layered materials are emerging as a solid-state materials family that exhibits novel physics phenomena that can power a range of electronic and photonic applications. Here, we present the first demonstration of an important building block in vdW solids: room temperature Esaki tunnel diodes. The Esaki diodes were realized in vdW heterostructures made of black phosphorus (BP) and tin diselenide (SnSe2), two layered semiconductors that possess a broken-gap energy band offset. The presence of a thin insulating barrier between BP and SnSe2 enabled the observation of a prominent negative differential resistance (NDR) region in the forward-bias current-voltage characteristics, with a peak to valley ratio of 1.8 at 300 K and 2.8 at 80 K. A weak temperature dependence of the NDR indicates electron tunneling being the dominant transport mechanism, and a theoretical model shows excellent agreement with the experimental results. Furthermore, the broken-gap band alignment is confirmed by the junction photoresponse, and the phosphorus double planes in a single layer of BP are resolved in transmission electron microscopy (TEM) for the first time. Our results represent a significant advance in the fundamental understanding of vdW heterojunctions and broaden the potential applications of 2D layered materials.

  4. 1-FFT amino acids involved in high DP inulin accumulation in Viguiera discolor.

    PubMed

    De Sadeleer, Emerik; Vergauwen, Rudy; Struyf, Tom; Le Roy, Katrien; Van den Ende, Wim

    2015-01-01

    Fructans are important vacuolar reserve carbohydrates with drought, cold, ROS and general abiotic stress mediating properties. They occur in 15% of all flowering plants and are believed to display health benefits as a prebiotic and dietary fiber. Fructans are synthesized by specific fructosyltransferases and classified based on the linkage type between fructosyl units. Inulins, one of these fructan types with β(2-1) linkages, are elongated by fructan:fructan 1-fructosyltransferases (1-FFT) using a fructosyl unit from a donor inulin to elongate the acceptor inulin molecule. The sequence identity of the 1-FFT of Viguiera discolor (Vd) and Helianthus tuberosus (Ht) is 91% although these enzymes produce distinct fructans. The Vd 1-FFT produces high degree of polymerization (DP) inulins by preferring the elongation of long chain inulins, in contrast to the Ht 1-FFT which prefers small molecules (DP3 or 4) as acceptor. Since higher DP inulins have interesting properties for industrial, food and medical applications, we report here on the influence of two amino acids on the high DP inulin production capacity of the Vd 1-FFT. Introducing the M19F and H308T mutations in the active site of the Vd 1-FFT greatly reduces its capacity to produce high DP inulin molecules. Both amino acids can be considered important to this capacity, although the double mutation had a much higher impact than the single mutations.

  5. 14 CFR 23.253 - High speed characteristics.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under... airspeed limit altitude. (b) Allowing for pilot reaction time after occurrence of the effective inherent or...) Exceeding VD/MD, or VDF/MDF for turbojets, the maximum speed shown under § 23.251, or the...

  6. 14 CFR 23.253 - High speed characteristics.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Requirements § 23.253 High speed characteristics. If a maximum operating speed VMO/MMO is established under... airspeed limit altitude. (b) Allowing for pilot reaction time after occurrence of the effective inherent or...) Exceeding VD/MD, or VDF/MDF for turbojets, the maximum speed shown under § 23.251, or the...

  7. 14 CFR 23.253 - High speed characteristics.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., 2011. If a maximum operating speed VMO/MMO is established under § 23.1505(c), the following speed..., passenger movement, leveling off from climb, and descent from Mach to airspeed limit altitude. (b) Allowing... speed reduced to VMO/MMO, without— (1) Exceeding VD/MD, the maximum speed shown under § 23.251, or...

  8. Advanced Technology Component Derating

    DTIC Science & Technology

    1992-02-01

    Mike, ’WSI: A Technology For Reliability,’ Yield Modeling And Defect Tolerance In VLSI 73. Meredith, John W., ’Microelectronics Reliability,’ IEEE Region...34Reterojunction Bipolar Digital ICs Using M=VD Material,’ IEEE Gallium Arsenide Tntegrated Circuit Symposium, 1986 156 121. Wilhems n, Finn, Yee

  9. A characterization of structural proteins expressed by Bombyx mori bidensovirus.

    PubMed

    Lü, Peng; Xing, Yali; Hu, Zhaoyang; Yang, Yanhua; Pan, Ye; Chen, Kangmin; Zhu, Feifei; Zhou, Yajing; Chen, Keping; Yao, Qin

    2017-03-01

    Bombyx mori bidensiovirus (BmBDV) is a species of Bidensovirus that has been was placed into a new genus within the new family Bidnaviridae by the International Committee on Taxonomy of Viruses. BmBDV causes fatal flacherie disease in silkworms, which causes large losses to the sericulture industry. BmBDV contains two sets of complementary linear single-stranded DNAs of approximately 6.5kb (viral DNA 1, VD1) and 6.0kb (viral DNA 2, VD2). VD1 and VD2 are encapsidated in separate icosahedral non-enveloped capsids, which are similar in size and shape. However, the strategies used to express BmBDV structural proteins remains unclear. In this work, a total of six structural proteins were separated by two-dimensional electrophoresis and shown to be encoded by the BmBDV VP gene via mass spectrometry. The transmission electron microscopy results showed that co-expression of the BmBDV VP and SP structural proteins in Spodoptera frugiperda sf9 cells resulted in the formation of 22-24nm virus-like particles. Furthermore, a mutation of the major structural protein-encoding VP gene, in which the second in-frame ATG codon was mutated to GCG, abrogated the production of several structural proteins, indicating that this strategy of expressing BmBDV VP is dependent on a leaky scanning translation mechanism.

  10. 7 CFR 51.888 - Maturity requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of Agriculture, Citrus, Fruit and Vegetable Standardization, 1688 W. Adams, Phoenix, AZ 85007 or in... Vegetable Quality Control, Standardization Section, 1220 N Street, P.O. Box 942871, Sacramento, California 94271-0001 or copies of both regulations may be inspected at USDA, AMS, F&VD, FPB,...

  11. 25-hydroxyvitamin D levels and juvenile idiopathic arthritis: is there an association with disease activity?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the association between serum levels of 25-hydroxyvitamin D [25(OH)D] and disease activity in juvenile idiopathic arthritis (JIA), to determine the prevalence of vitamin D (VD) deficiency [25(OH)D=19 ng/ml] and insufficiency [25(OH)D 20-29 ng/ml], and to determine factors associated with ...

  12. A simplified Van der Waals-Platteeuw model of clathrate hydrates with multiple occupancy of cavities.

    PubMed

    Martín, Angel

    2010-07-29

    In clathrate hydrates formed by small guest molecules such as H(2) or He, hydrate cavities may be occupied by clusters of several guest molecules. Multiple occupancy of cavities is important for applications of clathrate hydrates as gas storage and transportation media due to the increase of storage capacity of the material associated with multiple occupancy. Computational approaches for clathrate hydrates with multiple occupancy such as Grand Canonical Monte Carlo (GCMC) simulations or van der Waals-Platteeuw (vdW-P) models with rigorous calculations of Langmuir adsorption constants are complex and require considerable computational effort. In this work, a simplified vdW-P model for clathrate hydrates with multiple occupancy is presented. In this model, it is assumed that guest molecules inside cavities form clusters in which molecules occupy fixed positions with respect to each other. For validation of this supposition, results obtained with this model have been compared with GCMC simulations of sII He and H(2) hydrates with multiple occupancy. Results of the simplified procedure presented in this work regarding the fractional occupancy of cavities by molecular clusters agree well with GCMC simulations. The simplified vdW-P model presented in this work requires a small computational effort, equivalent to calculations with the standard vdW-P model for hydrates with single occupancy.

  13. 26 CFR 1.460-4 - Methods of accounting for long-term contracts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... rules governing step-in-the-shoes transactions are provided in paragraph (k)(3) of this section. Special... distribution. (3) Step-in-the-shoes transactions—(i) Scope. Except as otherwise provided in paragraph (k)(3)(v)(D) of this section, the step-in-the-shoes rules in this paragraph (k)(3) apply to the...

  14. 26 CFR 1.460-4 - Methods of accounting for long-term contracts.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... rules governing step-in-the-shoes transactions are provided in paragraph (k)(3) of this section. Special... distribution. (3) Step-in-the-shoes transactions—(i) Scope. Except as otherwise provided in paragraph (k)(3)(v)(D) of this section, the step-in-the-shoes rules in this paragraph (k)(3) apply to the...

  15. 26 CFR 1.460-4 - Methods of accounting for long-term contracts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... rules governing step-in-the-shoes transactions are provided in paragraph (k)(3) of this section. Special... distribution. (3) Step-in-the-shoes transactions—(i) Scope. Except as otherwise provided in paragraph (k)(3)(v)(D) of this section, the step-in-the-shoes rules in this paragraph (k)(3) apply to the...

  16. 26 CFR 1.460-4 - Methods of accounting for long-term contracts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rules governing step-in-the-shoes transactions are provided in paragraph (k)(3) of this section. Special... distribution. (3) Step-in-the-shoes transactions—(i) Scope. Except as otherwise provided in paragraph (k)(3)(v)(D) of this section, the step-in-the-shoes rules in this paragraph (k)(3) apply to the...

  17. 26 CFR 1.460-4 - Methods of accounting for long-term contracts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... rules governing step-in-the-shoes transactions are provided in paragraph (k)(3) of this section. Special... distribution. (3) Step-in-the-shoes transactions—(i) Scope. Except as otherwise provided in paragraph (k)(3)(v)(D) of this section, the step-in-the-shoes rules in this paragraph (k)(3) apply to the...

  18. Caenorhabditis elegans flamingo cadherin fmi-1 regulates GABAergic neuronal development.

    PubMed

    Najarro, Elvis Huarcaya; Wong, Lianna; Zhen, Mei; Carpio, Edgar Pinedo; Goncharov, Alexandr; Garriga, Gian; Lundquist, Erik A; Jin, Yishi; Ackley, Brian D

    2012-03-21

    In a genetic screen for regulators of synaptic morphology, we identified the single Caenorhabditis elegans flamingo-like cadherin fmi-1. The fmi-1 mutants exhibit defective axon pathfinding, reduced synapse number, aberrant synapse size and morphology, as well as an abnormal accumulation of synaptic vesicles at nonsynaptic regions. Although FMI-1 is primarily expressed in the nervous system, it is not expressed in the ventral D-type (VD) GABAergic motorneurons, which are defective in fmi-1 mutants. The axon and synaptic defects of VD neurons could be rescued when fmi-1 was expressed exclusively in non-VD neighboring neurons, suggesting a cell nonautonomous action of FMI-1. FMI-1 protein that lacked its intracellular domain still retained its ability to rescue the vesicle accumulation defects of GABAergic motorneurons, indicating that the extracellular domain was sufficient for this function of FMI-1 in GABAergic neuromuscular junction development. Mutations in cdh-4, a Fat-like cadherin, cause similar defects in GABAergic motorneurons. The cdh-4 is expressed by the VD neurons and seems to function in the same genetic pathway as fmi-1 to regulate GABAergic neuron development. Thus, fmi-1 and cdh-4 cadherins might act together to regulate synapse development and axon pathfinding.

  19. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must be designed for loads resulting from— (1) Gust velocities specified in § 23.333(c) with flaps retracted; and... unaccelerated flight at the pertinent design speeds VF, VC, and VD must first be determined. The...

  20. Fabrication of WS2/GaN p-n Junction by Wafer-Scale WS2 Thin Film Transfer

    NASA Astrophysics Data System (ADS)

    Yu, Yang; Fong, Patrick W. K.; Wang, Shifeng; Surya, Charles

    2016-11-01

    High quality wafer-scale free-standing WS2 grown by van der Waals rheotaxy (vdWR) using Ni as a texture promoting layer is reported. The microstructure of vdWR grown WS2 was significantly modified from mixture of crystallites with their c-axes both parallel to (type I) and perpendicular to (type II) the substrate to large type II crystallites. Wafer-scale transfer of vdWR grown WS2 onto different substrates by an etching-free technique was demonstrated for the first time that utilized the hydrophobic property of WS2 and hydrophilic property of sapphire. Our results show that vdWR is a reliable technique to obtain type-II textured crystallites in WS2, which is the key factor for the wafer-scale etching-free transfer. The transferred films were found to be free of observable wrinkles, cracks, or polymer residues. High quality p-n junctions fabricated by room-temperature transfer of the p-type WS2 onto an n-type GaN was demonstrated with a small leakage current density of 29.6 μA/cm2 at ‑1 V which shows superior performances compared to the directly grown WS2/GaN heterojunctions.

  1. A Population Pharmacokinetic Approach to Describe Cephalexin Disposition in Adult and Aged Dogs

    PubMed Central

    Prados, Ana Paula; Kreil, Verónica; Monfrinotti, Agustina; Quaine, Pamela; Tarragona, Lisa; Hallu, Ruben

    2014-01-01

    This study was conducted in order to characterize the pharmacokinetics of orally administered cephalexin to healthy adult and aged dogs, using a population pharmacokinetic approach. Two hundred and eighty-six cephalexin plasma concentrations obtained from previous pharmacokinetic studies were used. Sex, age, pharmaceutical formulation, and breed were evaluated as covariates. A one-compartment model with an absorption lag-time (Tlag) best described the data. The final model included age (adult; aged) on apparent volume of distribution (Vd/F), apparent elimination rate (ke/F), and Tlag; sex (female; male) on ke/F, and breed (Beagle; mixed-breed) on Vd/F. Addition of the covariates to the model explained 78% of the interindividal variability (IIV) in Vd/F, 36% in ke/F, and 24% in Tlag, respectively. Formulation did not affect the variability of any of the pharmacokinetic parameters. Tlag was longer, whereas Vd/F and ke/F were lower in aged compared to adult animals; in female aged dogs ke/F was lower than in male aged dogs; however, the differences were of low magnitude. Different disposition of cephalexin may be expected in aged dogs. PMID:25431741

  2. Electronic structures and enhanced optical properties of blue phosphorene/transition metal dichalcogenides van der Waals heterostructures

    PubMed Central

    Peng, Qiong; Wang, Zhenyu; Sa, Baisheng; Wu, Bo; Sun, Zhimei

    2016-01-01

    As a fast emerging topic, van der Waals (vdW) heterostructures have been proposed to modify two-dimensional layered materials with desired properties, thus greatly extending the applications of these materials. In this work, the stacking characteristics, electronic structures, band edge alignments, charge density distributions and optical properties of blue phosphorene/transition metal dichalcogenides (BlueP/TMDs) vdW heterostructures were systematically studied based on vdW corrected density functional theory. Interestingly, the valence band maximum and conduction band minimum are located in different parts of BlueP/MoSe2, BlueP/WS2 and BlueP/WSe2 heterostructures. The MoSe2, WS2 or WSe2 layer can be used as the electron donor and the BlueP layer can be used as the electron acceptor. We further found that the optical properties under visible-light irradiation of BlueP/TMDs vdW heterostructures are significantly improved. In particular, the predicted upper limit energy conversion efficiencies of BlueP/MoS2 and BlueP/MoSe2 heterostructures reach as large as 1.16% and 0.98%, respectively, suggesting their potential applications in efficient thin-film solar cells and optoelectronic devices. PMID:27553787

  3. RADIAL VELOCITIES FROM VLT-KMOS SPECTRA OF GIANT STARS IN THE GLOBULAR CLUSTER NGC 6388

    SciTech Connect

    Lapenna, E.; Mucciarelli, A.; Lanzoni, B.; Ferraro, F. R.; Dalessandro, E.; Valenti, E.; Cirasuolo, M.

    2015-01-01

    We present new radial velocity measurements for 82 stars, members of the Galactic globular cluster (GC) NGC 6388, obtained from ESO-VLT K-band Multi Object Spectrograph (KMOS) spectra acquired during the instrument Science Verification. The accuracy of the wavelength calibration is discussed and a number of tests of the KMOS response are presented. The cluster systemic velocity obtained (81.3 ± 1.5 km s{sup –1}) is in very good agreement with previous determinations. While a hint of ordered rotation is found between 9'' and 20'' from the cluster center, where the distribution of radial velocities is clearly bimodal, more data are needed before drawing any firm conclusions. The acquired sample of radial velocities has also been used to determine the cluster velocity dispersion (VD) profile between ∼9'' and 70'', supplementing previous measurements at r < 2'' and r > 60'' obtained with ESO-SINFONI and ESO-FLAMES spectroscopy, respectively. The new portion of the VD profile nicely matches the previous ones, better defining the knee of the distribution. The present work clearly shows the effectiveness of a deployable integral field unit in measuring the radial velocities of individual stars for determining the VD profile of Galactic GCs. It represents the pilot project for an ongoing large program with KMOS and FLAMES at the ESO-VLT, aimed at determining the next generation of VD and rotation profiles for a representative sample of GCs.

  4. Paeoniflorin attenuates hippocampal damage in a rat model of vascular dementia

    PubMed Central

    Zhang, Ying; Wang, Li-Li; Wu, Yan; Wang, Ning; Wang, Shang-Ming; Zhang, Bin; Shi, Cui-Ge; Zhang, Shu-Cheng

    2016-01-01

    Paeoniflorn (PF), the principal bioactive component of Paeoniae radix prescribed in traditional Chinese medicine, possesses a wide range of biological effects and exhibits neuroprotective effects in numerous diseases. Previous studies have demonstrated that PF significantly attenuates memory impairment in rats with vascular dementia (VD). In the present study, a bilateral common carotid artery occlusion (BCCAO) rat model was used to explore the underlying mechanisms of PF. The expression levels of neuron-specific enolase (NSE), S100β, B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein, cytochrome c and brain-derived neurotrophic factor (BDNF) in the hippocampus were measured by western blot analysis. The results showed that administration of PF for 28 days significantly decreased the expression levels of NSE and S100β, both sensitive markers for brain damage, in vascular dementia (VD) model rats. In addition, PF inhibited the initiation of apoptotic cell death and attenuated the decreased expression levels of BDNF induced by bilateral common carotid artery occlusion. These data confirm the neuroprotective effects of PF on VD and provide a novel insight into the long-term use of PF as a potential treatment in the stages of early cognitive impairment in VD. PMID:28101164

  5. The direct-to-indirect band gap crossover in two-dimensional van der Waals Indium Selenide crystals

    PubMed Central

    Mudd, G. W.; Molas, M. R.; Chen, X.; Zólyomi, V.; Nogajewski, K.; Kudrynskyi, Z. R.; Kovalyuk, Z. D.; Yusa, G.; Makarovsky, O.; Eaves, L.; Potemski, M.; Fal’ko, V. I.; Patanè, A.

    2016-01-01

    The electronic band structure of van der Waals (vdW) layered crystals has properties that depend on the composition, thickness and stacking of the component layers. Here we use density functional theory and high field magneto-optics to investigate the metal chalcogenide InSe, a recent addition to the family of vdW layered crystals, which transforms from a direct to an indirect band gap semiconductor as the number of layers is reduced. We investigate this direct-to-indirect bandgap crossover, demonstrate a highly tuneable optical response from the near infrared to the visible spectrum with decreasing layer thickness down to 2 layers, and report quantum dot-like optical emissions distributed over a wide range of energy. Our analysis also indicates that electron and exciton effective masses are weakly dependent on the layer thickness and are significantly smaller than in other vdW crystals. These properties are unprecedented within the large family of vdW crystals and demonstrate the potential of InSe for electronic and photonic technologies. PMID:28008964

  6. Identification of pathogenicity-related genes in the vascular wilt fungus Verticillium dahliae by Agrobacterium tumefaciens-mediated T-DNA insertional mutagenesis.

    PubMed

    Maruthachalam, K; Klosterman, S J; Kang, S; Hayes, R J; Subbarao, K V

    2011-11-01

    Verticillium dahliae is the causal agent of vascular wilt in many economically important crops worldwide. Identification of genes that control pathogenicity or virulence may suggest targets for alternative control methods for this fungus. In this study, Agrobacterium tumefaciens-mediated transformation (ATMT) was applied for insertional mutagenesis of V. dahliae conidia. Southern blot analysis indicated that T-DNAs were inserted randomly into the V. dahliae genome and that 69% of the transformants were the result of single copy T-DNA insertion. DNA sequences flanking T-DNA insertion were isolated through inverse PCR (iPCR), and these sequences were aligned to the genome sequence to identify the genomic position of insertion. V. dahliae mutants of particular interest selected based on culture phenotypes included those that had lost the ability to form microsclerotia and subsequently used for virulence assay. Based on the virulence assay of 181 transformants, we identified several mutant strains of V. dahliae that did not cause symptoms on lettuce plants. Among these mutants, T-DNA was inserted in genes encoding an endoglucanase 1 (VdEg-1), a hydroxyl-methyl glutaryl-CoA synthase (VdHMGS), a major facilitator superfamily 1 (VdMFS1), and a glycosylphosphatidylinositol (GPI) mannosyltransferase 3 (VdGPIM3). These results suggest that ATMT can effectively be used to identify genes associated with pathogenicity and other functions in V. dahliae.

  7. 14 CFR 23.441 - Maneuvering loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... from VA to VD/MD. When computing the tail loads— (1) The airplane must be yawed to the largest... Maneuvering loads. (a) At speeds up to V A, the vertical surfaces must be designed to withstand the following conditions. In computing the loads, the yawing velocity may be assumed to be zero: (1) With the airplane...

  8. Prevalence and characterization of Chlamydia DNA in zoo animals in Japan.

    PubMed

    Kabeya, Hidenori; Sato, Shingo; Maruyama, Soichi

    2015-09-01

    Because many people visit zoos, prevention of zoonoses is important from the standpoint of public health. This study examined the prevalence of Chlamydia among zoo animals in Japan by PCR and characterized these bacteria by performing phylogenetic analyses of the sequences of the variable domain (VD) 2 and VD4 regions of the ompA gene, which encodes the Chlamydia major outer membrane protein. Fecal samples were collected from 1150 zoo animals in five zoos and examined for Chlamydia DNA. Chlamydia psittaci DNA was found in 3.9% of mammals, 7.2% of birds and 8.1% of reptiles. The prevalence of Chlamydia pneumoniae DNA was significantly higher in reptiles (5.8%) than in mammals (0.3%) and birds (0.3%). Phylogenetic analysis of the ompA VD2 region from 18 samples showed that nine were in three different clusters containing C. psittaci strains, six were in a cluster containing C. pneumoniae strains and three each formed a distinct branch. Furthermore, phylogenetic analysis of the ompA VD4 region showed that C. pneumoniae DNAs from reptiles were close to those from human patients. The C. pneumoniae DNAs from the European glass lizard, Emerald tree boa, and Panther chameleon were classified in clusters that were distinct from other strains, suggesting that these reptiles had each been infected with a specific C. pneumoniae genotype. This study showed that diverse Chlamydia strains have been prevalent among a variety of zoo animals.

  9. The Design and Use of a Viscometer for the Study of Reacting Resin Systems.

    DTIC Science & Technology

    1981-11-01

    VD is derived from a unit referred to as a function generator. In Fig 7b a clock pulse is fed into a counter E whose output feeds a digital-to...unit requires a supply of compressed air to energise the torque transducer; this comes from an external 240 V ac mtor -driven pump which, together with a

  10. Collected Works of the 30th Chief of Staff, United States Army, June 1983 - June 1987

    DTIC Science & Technology

    1987-06-01

    and steldy piogrets m ow moa tim- -ota alba ... . ’N 2%. *.. .........*. ......... . % % The time now seems right for a more positive Anwr - To fufill...vd- .%m take his poncho off hts head loge and came upon some natives sewing up a horsewhich had been bitten by a coccodde -Do you know %ihv I r

  11. Characterization of giardin protein expression during encystation of Giardia duodenalis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giardia duodenalis trophozoites attach to the gut surface by means of a ventral disk that contains various giardin proteins that appear to be important to VD structural integrity. One approach to preventing giardiasis is to stimulate giardin-specific antibodies and thereby block trophozoite attachme...

  12. Amplification of terahertz frequency acoustic phonons by drifting electrons in three-dimensional Dirac semimetals

    NASA Astrophysics Data System (ADS)

    Bhargavi, K. S.; Kubakaddi, S. S.

    2016-09-01

    The amplification coefficient α of acoustic phonons is theoretically investigated in a three-dimensional Dirac semimetal (3DDS) driven by a dc electric field E causing the drift of the electrons. It is numerically studied as a function of the frequency ωq, drift velocity vd, electron concentration ne, and temperature T in the Dirac semimetal Cd3As2. We find that the amplification of acoustic phonons (α ˜ hundreds of cm-1) takes place when the electron drift velocity vd is greater than the sound velocity vs. The amplification is found to occur at small E (˜few V/cm) due to large electron mobility. The frequency dependence of α shows amplification in the THz regime with a maximum αm occurring at the same frequency ωqm for different vd. The αm is found to increase with increasing vd. α vs ωq for different ne also shows a maximum, with αm shifting to higher ωq for larger ne. Each maximum is followed by a vanishing α at nearly "2kf cutoff," where kf is the Fermi wave vector. It is found that αm/ne and ωqm/ne1/3 are nearly constant. The αm ˜ ne can be used to identify the 3DDS phase as it differs from αm ˜ ne1/3 dependence in conventional bulk Cd3As2 semiconductor.

  13. How van der Waals interactions determine the unique properties of water

    PubMed Central

    Morawietz, Tobias; Singraber, Andreas; Dellago, Christoph; Behler, Jörg

    2016-01-01

    Whereas the interactions between water molecules are dominated by strongly directional hydrogen bonds (HBs), it was recently proposed that relatively weak, isotropic van der Waals (vdW) forces are essential for understanding the properties of liquid water and ice. This insight was derived from ab initio computer simulations, which provide an unbiased description of water at the atomic level and yield information on the underlying molecular forces. However, the high computational cost of such simulations prevents the systematic investigation of the influence of vdW forces on the thermodynamic anomalies of water. Here, we develop efficient ab initio-quality neural network potentials and use them to demonstrate that vdW interactions are crucial for the formation of water’s density maximum and its negative volume of melting. Both phenomena can be explained by the flexibility of the HB network, which is the result of a delicate balance of weak vdW forces, causing, e.g., a pronounced expansion of the second solvation shell upon cooling that induces the density maximum. PMID:27402761

  14. Sensory-induced plasticity of motor pattern selection in the lobster stomatogastric nervous system.

    PubMed

    Nargeot, R; Moulins, M

    1997-08-01

    In a previous study, a bilateral sensory input pathway to the crustacean stomatogastric nervous system was reported to induce the functional switching of an identified motor neuron (VD) from one rhythm generating neural network (the pyloric circuit) to another (the cardiac sac network). In the present in vitro study on the spiny lobster, Palinurus vulgaris, we have shown that under certain conditions, repetitive trains of phasic stimulation (1 s, 40 Hz) of one of these sensory nerves elicits either an increase or a decrease in efficacy of the VD switching response. In preparations showing no previous sign either of increase or decrease in VD switching, either response can be induced by prior conditioning stimulation. The increasing effect can be induced by unpaired conditioning stimulation of the contralateral sensory nerve. Conversely, the decrease in switching efficacy is obtained by pairing stimulation of the sensory-motor pathway with that applied to its contralateral partner. Both the experimentally induced increase and decrease in VD switching are long-lasting, remaining observable for at least 20 min and in some cases up to 3 h after the original conditioning procedure. Our results suggest that this system provides a suitable 'simple' model for the analysis of experience-related plasticity of the switching of a neuron from one network to another.

  15. Anaerobic soil disinfestation disease control performance in strawberry as influenced by environmental variables

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustainability of the California strawberry industry is challenged by soil-borne diseases caused by Fusarium oxysporum (Fo), Macrophomina phaseolina (Mp) and Verticillium dahliae (Vd). Anaerobic soil disinfestation (ASD) has been studied as a non-fumigant measure for control of these diseases. This ...

  16. Accurate and efficient calculation of van der Waals interactions within density functional theory by local atomic potential approach.

    PubMed

    Sun, Y Y; Kim, Yong-Hyun; Lee, Kyuho; Zhang, S B

    2008-10-21

    Density functional theory (DFT) in the commonly used local density or generalized gradient approximation fails to describe van der Waals (vdW) interactions that are vital to organic, biological, and other molecular systems. Here, we propose a simple, efficient, yet accurate local atomic potential (LAP) approach, named DFT+LAP, for including vdW interactions in the framework of DFT. The LAPs for H, C, N, and O are generated by fitting the DFT+LAP potential energy curves of small molecule dimers to those obtained from coupled cluster calculations with single, double, and perturbatively treated triple excitations, CCSD(T). Excellent transferability of the LAPs is demonstrated by remarkable agreement with the JSCH-2005 benchmark database [P. Jurecka et al. Phys. Chem. Chem. Phys. 8, 1985 (2006)], which provides the interaction energies of CCSD(T) quality for 165 vdW and hydrogen-bonded complexes. For over 100 vdW dominant complexes in this database, our DFT+LAP calculations give a mean absolute deviation from the benchmark results less than 0.5 kcal/mol. The DFT+LAP approach involves no extra computational cost other than standard DFT calculations and no modification of existing DFT codes, which enables straightforward quantum simulations, such as ab initio molecular dynamics, on biomolecular systems, as well as on other organic systems.

  17. Dry deposition of O3 and SO2 estimated from gradient measurements above a temperate mixed forest.

    PubMed

    Wu, Zhiyong; Staebler, Ralf; Vet, Robert; Zhang, Leiming

    2016-03-01

    Vertical profiles of O3 and SO2 concentrations were monitored at the Borden Forest site in southern Ontario, Canada from May 2008 to April 2013. A modified gradient method (MGM) was applied to estimate O3 and SO2 dry deposition fluxes using concentration gradients between a level above and a level below the canopy top. The calculated five-year mean (median) dry deposition velocity (Vd) were 0.35 (0.27) and 0.59 (0.54) cm s(-1), respectively, for O3 and SO2. Vd(O3) exhibited large seasonal variations with the highest monthly mean of 0.68 cm s(-1) in August and the lowest of 0.09 cm s(-1) in February. In contrast, seasonal variations of Vd(SO2) were smaller with monthly means ranging from 0.48 (May) to 0.81 cm s(-1) (December). The different seasonal variations between O3 and SO2 were caused by the enhanced SO2 uptake by snow surfaces in winter. Diurnal variations showed a peak value of Vd in early morning in summer months for both O3 and SO2. Canopy wetness increased the non-stomatal uptake of O3 while decreasing the stomatal uptake. This also applied to SO2, but additional factors such as surface acidity also played an important role on the overall uptake.

  18. Implementation of an Open-Loop Rule-Based Control Strategy for a Hybrid-Electric Propulsion System On a Small RPA

    DTIC Science & Technology

    2011-03-01

    ix List of Figures Figure 1: Series hybrid configuration [12... Electromotive Force (V) Um Electric Motor Open Circuit Voltage (V) u Clutch Displacement Angle (rad) Vbat Battery Voltage (V) Vd Cylinder Displacement...of three areas: series hybrid, parallel hybrid, and the power-split hybrid. A great number of these designs incorporate the gasoline internal

  19. The use of the SAEM algorithm in MONOLIX software for estimation of population pharmacokinetic-pharmacodynamic-viral dynamics parameters of maraviroc in asymptomatic HIV subjects.

    PubMed

    Chan, Phylinda L S; Jacqmin, Philippe; Lavielle, Marc; McFadyen, Lynn; Weatherley, Barry

    2011-02-01

    Using simulated viral load data for a given maraviroc monotherapy study design, the feasibility of different algorithms to perform parameter estimation for a pharmacokinetic-pharmacodynamic-viral dynamics (PKPD-VD) model was assessed. The assessed algorithms are the first-order conditional estimation method with interaction (FOCEI) implemented in NONMEM VI and the SAEM algorithm implemented in MONOLIX version 2.4. Simulated data were also used to test if an effect compartment and/or a lag time could be distinguished to describe an observed delay in onset of viral inhibition using SAEM. The preferred model was then used to describe the observed maraviroc monotherapy plasma concentration and viral load data using SAEM. In this last step, three modelling approaches were compared; (i) sequential PKPD-VD with fixed individual Empirical Bayesian Estimates (EBE) for PK, (ii) sequential PKPD-VD with fixed population PK parameters and including concentrations, and (iii) simultaneous PKPD-VD. Using FOCEI, many convergence problems (56%) were experienced with fitting the sequential PKPD-VD model to the simulated data. For the sequential modelling approach, SAEM (with default settings) took less time to generate population and individual estimates including diagnostics than with FOCEI without diagnostics. For the given maraviroc monotherapy sampling design, it was difficult to separate the viral dynamics system delay from a pharmacokinetic distributional delay or delay due to receptor binding and subsequent cellular signalling. The preferred model included a viral load lag time without inter-individual variability. Parameter estimates from the SAEM analysis of observed data were comparable among the three modelling approaches. For the sequential methods, computation time is approximately 25% less when fixing individual EBE of PK parameters with omission of the concentration data compared with fixed population PK parameters and retention of concentration data in the PD-VD

  20. Vaginal douching by women with vulvovaginitis and relation to reproductive health hazards

    PubMed Central

    2013-01-01

    Background Vaginal douching (VD) is a common practice among married women all over the world specially those in the Middle East. It is used for personal hygiene or for other aesthetic reasons in many countries. The current study investigates the prevalence of VD among patients with vulvovaginitis in Egypt. It also compares the reproductive health hazards among women performing routine VD with those using external hygiene. It also investigates why, and how women practice this douching. Methods A cross sectional observational study was conducted in a tertiary university affiliated hospital in Assiut, Egypt. An interview administered questionnaire was administered to 620 women by two trained clinic nurses. Women presented to the outpatient clinic and diagnosed to have any type of vaginal infections were approached for participation. The principle outcome was the history of preterm labor in women who routinely performed VD versus those who did not (upon which sample size was estimated). Other outcome measures were the types of vaginal infections, and reproductive implications comprising, ectopic pregnancy, abortion and pelvic inflammatory disease (PID). Results The participants were predominantly multiparas from semi-urban background and middle socioeconomic level. Considering VD as a religious duty and a kind of personal cleanliness were the most common reasons for performing VD in 88.9% and 80.6% of the studied population, respectively. History of preterm labor was reported in 19.2% versus 11.9% (p=0.048), while history of PID in 13.2% versus 6.0% (p=0.008) in women performing VD compared to those not performing this habit, respectively. There were no significant differences between the two groups as regard the history of ectopic pregnancy or the number of previous abortions. Conclusion Vaginal douching is a prevalent practice in Egypt and has traditional and religious roots within the community. There are many misbeliefs around this habit in Egypt. Vaginal douching

  1. Anti-inflammatory effects of 1,25-dihydroxyvitamin D3 in monocytes cultured in serum from patients with type 2 diabetes mellitus and diabetic nephropathy with uremia via Toll-like receptor 4 and nuclear factor-κB p65.

    PubMed

    Yang, Mengxue; Xu, Jie; Yu, Jie; Yang, Bo; Gan, Hua; Li, Sicheng; Li, Xianwen

    2015-12-01

    Type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN) seriously affect the quality of human life. 1,25-dihydroxyvitamin D3 (VD3) is known to exert anti‑inflammatory and immunomodulatory effects. The present study investigated the effects of VD3 on Toll‑like receptor 4 (TLR4) and nuclear factor (NF)‑κB p65 expression in monocytes from patients with T2DM and investigated the underlying mechanisms. Serum from subjects of the control, T2DM and DN with uremia groups was isolated, and THP‑1 monocytes were cultured in these sera with or without VD3. After treatment with lipopolysaccharide (LPS) and interleukin (IL)‑15, monocytes and culture supernatants were collected. The expression of TLR4, TLR9 and IL‑15 mRNA was detected using reverse‑transcription polymerase chain reaction analysis. Furthermore, the protein expression of TLR4, NF‑κB p65 and inhibitor of NF‑κB (IκB) was determined using western blot analysis. The levels of IL‑6 and monocyte chemotactic protein in culture supernatants were detected using ELISAs. The impact of LPS, IL‑15 and VD3 on the TLR/NF‑κB signaling pathway in the T2DM and DN uremia groups was also investigated. In the T2DM and DN uremia groups, LPS and IL‑15 downregulated the expression of IκB and upregulated levels of proteins, including TLR4, NF‑κB p65, IL‑6 and monocyte chemoattractant protein 1, as well as TLR4 and IL‑15 mRNA. There was no significant difference in TLR9 mRNA protein expression among the three groups. VD3 partially blocked the above effects; However, pre‑treatment with VD3 had no significant effect on TLR4 mRNA expression, protein expression of NF-κB p65 and IκB, or the levels of associated inflammatory cytokines. In conclusion, the present study indicated that anti‑inflammatory effects of VD3 in inflammatory immune responses in T2DM and DN uremia are associated with the TLR4/NF-κB p65 signaling pathway.

  2. van der Waals Corrected Density Functional Theory Calculations on Zeolitic Imidazolate Frameworks

    NASA Astrophysics Data System (ADS)

    Ray, Keith George

    The van der Waals force is ubiquitous in nature, however, first principles calculations of this interaction for large systems, i.e., around 1000 atoms, have been performed only recently. In the following are presented results on the application of the van der Waals density functional (vdW-DF) to gas adsorption and transport in zeolitic imidazolate frameworks (ZIFs). Carbon dioxide and methane binding energies and positions are calculated with the vdW-DF in three distinct binding sites in a series of five rho topology ZIFs. The isostructural set of ZIFs was selected in order to isolate the effect of framework functionalization. Gas molecules are found to bind in locations with high coordination to framework atoms at distances of around 3 A. Contributions to the binding energy from induced polarization and dispersion are quantified in order to elucidate the origins of strong CO2 adsorption and selectivity over CH4. The dispersion energy is found to dominate the interactions, however, CO2 adsorption is also enhanced by electrostatic interactions with asymmetrically functionalized linkers. Steric constraints for methane molecules, that do not impede carbon dioxide binding, further contribute to selectivity. Binding energy landscapes for CO2 and CH4 are calculated using classical force fields for the same set of rho ZIFs and several other ZIFs that differ in functionalization and topology. Quantities extracted from these landscapes are used to explain the effect of framework topology on gas adsorption at low and high pressure as well as how the positions of adsorbed gas molecules evolve as a function of pressure. Materials with large surface areas have greater gas uptake at high pressure, while smaller pores, which are associated with stronger binding, adsorb more gas at low pressure. Finally, the effect of framework flexibility on CO2 transport through the double 8-ring channel of ZIF-97 is investigated with computationally intensive climbing-nudged elastic band

  3. Water use and quality of fresh surface-water resources in the Barataria-Terrebonne Basins, Louisiana

    USGS Publications Warehouse

    Johnson-Thibaut, Penny M.; Demcheck, Dennis K.; Swarzenski, Christopher M.; Ensminger, Paul A.

    1998-01-01

    Approximately 170 Mgal/d (million gallons per day) of ground- and surface-water was withdrawn from the Barataria-Terrebonne Basins in 1995. Of this amount, surface water accounted for 64 percent ( 110 MgaVd) of the total withdrawal rates in the basins. The largest surface-water withdrawal rates were from Bayou Lafourche ( 40 Mgal/d), Bayou Boeuf ( 14 MgaVd), and the Gulf Intracoastal Waterway (4.2 Mgal/d). The largest ground-water withdrawal rates were from the Mississippi River alluvial aquifer (29 Mgal/d), the Gonzales-New Orleans aquifer (9.5 Mgal/d), and the Norco aquifer (3.6 MgaVd). The amounts of water withdrawn in the basins in 1995 differed by category of use. Public water suppliers within the basins withdrew 41 Mgal/d of water. The five largest public water suppliers in the basins withdrew 30 Mgal/d of surface water: Terrebonne Waterworks District 1 withdrew the largest amount, almost 15 MgaVd. Industrial facilities withdrew 88 Mgal/d, fossil-fuel plants withdrew 4.7 MgaVd, and commercial facilities withdrew 0.67 MgaVd. Aggregate water-withdrawal rates, compiled by parish for aquaculture (37 Mgal/d), livestock (0.56 Mgal/d), rural domestic (0.44 MgaVd), and irrigation uses (0.54 MgaVd), totaled about 38 MgaVd in the basins. Ninety-five percent of aquaculture withdrawal rates, primarily for crawfish and alligator farming, were from surface-water sources. >br> Total water-withdrawal rates increased 221 percent from 1960–95. Surface-water withdrawal rates have increased by 310 percent, and ground-water withdrawal rates have increased by 133 percent. The projection for the total water-withdrawal rates in 2020 is 220 MgaVd, an increase of 30 percent from 1995. Surface-water withdrawal rates would account for 59 percent of the total, or 130 Mgal/d. Surface-water withdrawal rates are projected to increase by 20 percent from 1995 to 2020. Analysis of water-quality data from the Mississippi River indicates that the main threats to surface water resources are

  4. Partial protective of chickens against Eimeria tenella challenge with recombinant EtMIC-1 antigen.

    PubMed

    Qi, N S; Wang, Y Y; Liao, S Q; Wu, C Y; Lv, M N; Li, J; Tong, Z X; Sun, M F

    2013-06-01

    Eimeria tenella microneme protein 1 (EtMIC-1) is highly conserved with TgMIC-2, which is involved in parasite binding specifically to host cells. Little is known about the immune responses and protective efficacy against E. tenella infection with EtMIC-1 antigen. In the present study, the recombinant proteins of E. tenella mature MIC-1 and adhesive domain (von Willebrand factor type A domain, EtMIC-1-VD) were obtained, protective efficacy against E.tenella infection and the mucosal immune response, which is induced in broilers was evaluated. The antibody levels and the transcription profiles of cytokine of chickens, such as interleukin-12 (IL-12) and interferon-γ (IFN-γ), were detected after being immunized three times with the recombinant EtMIC-1 and EtMIC-1-VD by ELISA assay and quantitative real-time PCR, respectively. The results showed that both groups of chickens, after being immunized with 100 μg EtMIC-1 or EtMIC-1-VD antigen, induced about tenfold higher IgG levels compared to the nonimmune groups. The transcription profiles of IL-12 and IFN-γ of the immunized groups were significantly higher than the control groups as well. The anticoccidial index of the group immunized with 100 μg EtMIC-1 and the group immunized with 100 μg EtMIC-1-VD were 167.2 and 165.5, respectively, which are significantly higher than low-dose immunized groups and challenged control groups. Our data suggests that VD domain is the key functional structure of EtMIC-1 that could trigger a significant humoral and cellular response against E. tenella infection, and EtMIC-1 had the potential in imparting partial protection in chickens against homologous challenge.

  5. Pilot study on the bioactivity of vitamin d in the skin after oral supplementation.

    PubMed

    Curiel-Lewandrowski, Clara; Tang, Jean Y; Einspahr, Janine G; Bermudez, Yira; Hsu, Chiu Hsieh; Rezaee, Melika; Lee, Alex H; Tangrea, Joseph; Parnes, Howard L; Alberts, David S; Chow, H-H Sherry

    2015-06-01

    Laboratory studies suggest that vitamin D (VD) supplementation inhibits skin carcinogenesis. However, epidemiologic studies report mixed findings in the association between circulating VD levels and skin cancer risk. We conducted a clinical study to determine whether oral cholecalciferol supplementation would exert direct bioactivity in human skin through modulation of the VD receptor (VDR). We enrolled 25 individuals with serum 25-hydroxyvitamin-D levels <30 ng/mL and with skin photodamage to take 50,000 IU of cholecalciferol biweekly for 8 to 9 weeks. Then, we obtained baseline and end-of-study skin biopsies from photodamaged (PD) and photoprotected (PP) skin, and from benign nevi (BN) and tested for mRNA expression of VDR and cytochrome P450-24 (CYP24), and markers of keratinocytic differentiation. High-dose cholecalciferol supplementation significantly elevated circulating levels of 25-hydroxyvitamin-D (P < 0.0001) and 1,25-dihydroxyvitamin-D (P < 0.0001). VDR expression in PD- and PP-skin showed minimum changes after supplementation. CYP24 expression in PD- and PP-skin was increased after supplementation by 186%, P = 0.08, and 134%, P = 0.07, respectively. In BNs from 11 participants, a trend for higher VDR and CYP24 expression was observed (average of 20%, P = 0.08, and 544%, P = 0.09, respectively). Caspase-14 expression at the basal layer in PD skin samples was the only epidermal differentiation marker that was significantly increased (49%, P < 0.0001). High-dose cholecalciferol supplementation raised serum VD metabolite levels concurrently with CYP24 mRNA and caspase-14 levels in the skin. Our findings of significant variability in the range of VDR and CYP24 expression across study samples represent an important consideration in studies evaluating the role of VD as a skin cancer chemopreventive agent.

  6. Mechanistic Origin of the Ultrastrong Adhesion between Graphene and a-SiO2: Beyond van der Waals.

    PubMed

    Kumar, Sandeep; Parks, David; Kamrin, Ken

    2016-07-26

    The origin of the ultrastrong adhesion between graphene and a-SiO2 has remained a mystery. This adhesion is believed to be predominantly van der Waals (vdW) in nature. By rigorously analyzing recently reported blistering and nanoindentation experiments, we show that the ultrastrong adhesion between graphene and a-SiO2 cannot be attributed to vdW forces alone. Our analyses show that the fracture toughness of the graphene/a-SiO2 interface, when the interfacial adhesion is modeled with vdW forces alone, is anomalously weak compared to the measured values. The anomaly is related to an ultrasmall fracture process zone (FPZ): owing to the lack of a third dimension in graphene, the FPZ for the graphene/a-SiO2 interface is extremely small, and the combination of predominantly tensile vdW forces, distributed over such a small area, is bound to result in a correspondingly small interfacial fracture toughness. Through multiscale modeling, combining the results of finite element analysis and molecular dynamics simulations, we show that the adhesion between graphene and a-SiO2 involves two different kinds of interactions: one, a weak, long-range interaction arising from vdW adhesion and, second, discrete, short-range interactions originating from graphene clinging to the undercoordinated Si (≡Si·) and the nonbridging O (≡Si-O·) defects on a-SiO2. A strong resistance to relative opening and sliding provided by the latter mechanism is identified as the operative mechanism responsible for the ultrastrong adhesion between graphene and a-SiO2.

  7. A modified micrometeorological gradient method for estimating O3 dry deposition over a forest canopy

    NASA Astrophysics Data System (ADS)

    Wu, Z. Y.; Zhang, L.; Wang, X. M.; Munger, J. W.

    2015-01-01

    Small pollutant concentration gradients between levels above a plant canopy result in large uncertainties in estimated air-surface exchange fluxes when using existing micrometeorological gradient methods, including the aerodynamic gradient method (AGM) and the modified Bowen-Ratio method (MBR). A modified micrometeorological gradient method (MGM) is proposed in this study for estimating O3 dry deposition fluxes over a forest canopy using concentration gradients between a level above and a level below the canopy top, taking advantage of relatively large gradients between these levels due to significant pollutant uptake at top layers of the canopy. The new method is compared with the AGM and MBR methods and is also evaluated using eddy-covariance (EC) flux measurements collected at the Harvard Forest Environmental Measurement Site, Massachusetts during 1993-2000. All the three gradient methods (AGM, MBR and MGM) produced similar diurnal cycles of O3 dry deposition velocity (Vd(O3)) to the EC measurements, with the MGM method being the closest in magnitude to the EC measurements. The multi-year average Vd(O3) differed significantly between these methods, with the AGM, MBR and MGM method being 2.28, 1.45 and 1.18 times of that of the EC. Sensitivity experiments identified several input parameters for the MGM method as first-order parameters that affect the estimated Vd(O3). A 10% uncertainty in the wind speed attenuation coefficient or canopy displacement height can cause about 10% uncertainty in the estimated Vd(O3). An unrealistic leaf area density vertical profile can cause an uncertainty of a factor of 2.0 in the estimated Vd(O3). Other input parameters or formulas for stability functions only caused an uncertainly of a few percent. The new method provides an alternative approach in monitoring/estimating long-term deposition fluxes of similar pollutants over tall canopies.

  8. A modified micrometeorological gradient method for estimating O3 dry depositions over a forest canopy

    NASA Astrophysics Data System (ADS)

    Wu, Z. Y.; Zhang, L.; Wang, X. M.; Munger, J. W.

    2015-07-01

    Small pollutant concentration gradients between levels above a plant canopy result in large uncertainties in estimated air-surface exchange fluxes when using existing micrometeorological gradient methods, including the aerodynamic gradient method (AGM) and the modified Bowen ratio method (MBR). A modified micrometeorological gradient method (MGM) is proposed in this study for estimating O3 dry deposition fluxes over a forest canopy using concentration gradients between a level above and a level below the canopy top, taking advantage of relatively large gradients between these levels due to significant pollutant uptake in the top layers of the canopy. The new method is compared with the AGM and MBR methods and is also evaluated using eddy-covariance (EC) flux measurements collected at the Harvard Forest Environmental Measurement Site, Massachusetts, during 1993-2000. All three gradient methods (AGM, MBR, and MGM) produced similar diurnal cycles of O3 dry deposition velocity (Vd(O3)) to the EC measurements, with the MGM method being the closest in magnitude to the EC measurements. The multi-year average Vd(O3) differed significantly between these methods, with the AGM, MBR, and MGM method being 2.28, 1.45, and 1.18 times that of the EC, respectively. Sensitivity experiments identified several input parameters for the MGM method as first-order parameters that affect the estimated Vd(O3). A 10% uncertainty in the wind speed attenuation coefficient or canopy displacement height can cause about 10% uncertainty in the estimated Vd(O3). An unrealistic leaf area density vertical profile can cause an uncertainty of a factor of 2.0 in the estimated Vd(O3). Other input parameters or formulas for stability functions only caused an uncertainly of a few percent. The new method provides an alternative approach to monitoring/estimating long-term deposition fluxes of similar pollutants over tall canopies.

  9. Effect of Selective 5-HT6R Agonist on Expression of 5-HT Receptor and Neurotransmitter in Vascular Dementia Rats

    PubMed Central

    Yu, Haining; Chen, Tao; Zhou, Li; Tang, Jiyou

    2017-01-01

    Background 5-HT6 receptor (5-HT6R) has pluripotent roles regulating secretion of neurotransmitters. However, whether 5-HT6R is involved in the development of vascular dementia (VD) remains unclear. To evaluate the role and mechanism of 5-HT6R in VD, this study established a rat VD model to evaluate the effect of selective 5-HT6R agonist on the expression of 5-HT6R mRNA and neurotransmitter. Material/Methods Eighty healthy male SD rats (7 weeks old) were randomly assigned to sham, model, 5-HT6R agonist, and placebo groups (N=20 each). A rat VD model was generated by permeant bilateral ligation of the common carotid artery. 5-HT6R agonist, placebo, or saline were given intraperitoneally for 4 weeks. The Morris water maze was utilized to test learning and memory function. Brains were extracted to separate the cortex and hippocampal tissues, in which glutamate and γ-aminobutyric acid (GABA) levels were analyzed. mRNA and protein levels of 5-HT6R were determined by RT-PCR and immunohistochemistry (IHC), respectively. Results Model rats had longer escape latency and fewer crossing platform times. Contents of DA, Glu, GABA, and Ach were lowered in cortical and hippocampal tissues, and 5-HT6R expression was suppressed (p<0.05). The application of 5-HT6R agonist shortened escape latency and increased the number of passing through the platform. It also improved hippocampal CA1 neuronal damage and elevated DA, Glu, GABA, and Ach contents and expression of 5-HT6R. Expression of 5-HT6R was not different from the placebo group. Conclusions Selective 5-HT6R agonist can alleviate learning deficit of VD rats, possibly via improving neurotransmitter levels in brain regions. PMID:28196966

  10. The van der Waals coefficients between carbon nanostructures and small molecules: A time-dependent density functional theory study.

    PubMed

    Kamal, C; Ghanty, T K; Banerjee, Arup; Chakrabarti, Aparna

    2009-10-28

    We employ all-electron ab initio time-dependent density functional theory based method to calculate the long-range dipole-dipole dispersion coefficient, namely, the van der Waals (vdW) coefficient (C(6)) between fullerenes and finite-length carbon nanotubes as well as between these structures and different small molecules. Our aim is to accurately estimate the strength of the long-range vdW interaction in terms of the C(6) coefficients between these systems and also compare these values as a function of shape and size. The dispersion coefficients are obtained via Casimir-Polder relation. The calculations are carried out with the asymptotically correct exchange-correlation potential-the statistical average of orbital potential. It is observed from our calculations that the C(6) coefficients of the carbon nanotubes increase nonlinearly with length, which implies a much stronger vdW interaction between the longer carbon nanostructures compared with the shorter ones. Additionally, it is found that the values of C(6) and polarizability are about 40%-50% lower for the carbon cages when compared with the results corresponding to the quasi-one-dimensional nanotubes with equivalent number of atoms. From our calculations of the vdW coefficients between the small molecules and the carbon nanostructures, it is observed that for H(2), the C(6) value is much larger compared with that of He. It is found that the rare gas atoms have very low values of vdW coefficient with the carbon nanostructures. In contrast, it is found that other gas molecules, including the ones that are environmentally important, possess much higher C(6) values. Carbon tetrachloride as well as chlorine molecule show very high C(6) values with themselves as well as with the carbon nanostructures. This is due to the presence of the weakly bound seven electrons in the valence state for the halogen atoms, which makes these compounds much more polarizable compared with the others.

  11. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy.

    PubMed

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T; Chi, Miaofang; Kravchenko, Ivan; Fowlkes, Jason; Rouleau, Christopher M; Geohegan, David B; Xiao, Kai

    2016-04-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically thin electronics and optoelectronics because of their diverse functionalities. Although heterostructures consisting of different 2D materials with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) epitaxy, constructing heterostructures from layered semiconductors with large lattice misfits remains challenging. We report the growth of 2D GaSe/MoSe2 heterostructures with a large lattice misfit using two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between the two layers, forming a periodic superlattice. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructures at the crystal interface. Such vertically stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photogenerated charge carriers between layers, resulting in a gate-tunable photovoltaic response. These GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells.

  12. Nitric acid dry deposition to conifer forests: Niwot Ridge spruce-fir-pine study

    USGS Publications Warehouse

    Sievering, H.; Kelly, T.; McConville, G.; Seibold, C.; Turnipseed, A.

    2001-01-01

    The dry deposition velocity of nitric acid, Vd(HNO3), over a 12-m (mean height) spruce-fir forest at Niwot Ridge, Colorado was estimated during 13 daytime periods using the flux-gradient approach. Turbulence intensity at this site is high (mean u* of 0.65ms-1 with u of 2.9ms-1) and contributed to the large observed Vd(HNO3). The overriding contributor is identified to be the small aerodynamic needle width of the conifer trees. Two cases had inflated Vd(HNO3) due to height-differentiated nitric acid loss to soil-derived particle surfaces. Not considering these cases, the mean Vd(HNO3) was 7.6cms-1. The mean laminar boundary layer resistance (Rb) was found to be 7.8sm-1 (of similar magnitude to that of the aerodynamic resistance, 8.5sm-1). The data-determined Rb is bracketed by two theoretical estimates of the mean Rb, 5.9 and 8.6sm-1, that include consideration of the small canopy length scale (aerodynamic needle width), 1mm or less, at this conifer forest. However, the poor correlation of data-determined Rb values with both sets of theoretical estimates indicates that measurement error needs to be reduced and/or improved formulations of theoretical Rb values are in order. The large observed Vd(HNO3) at this conifer forest site is attributed to high turbulence intensity, and, especially, to small aerodynamic needle width. Copyright ?? 2001 Elsevier Science Ltd.

  13. Bacteria and bacterial DNA in atherosclerotic plaque and aneurysmal wall biopsies from patients with and without periodontitis

    PubMed Central

    Armingohar, Zahra; Jørgensen, Jørgen J.; Kristoffersen, Anne Karin; Abesha-Belay, Emnet; Olsen, Ingar

    2014-01-01

    Background Several studies have reported an association between chronic periodontitis (CP) and cardiovascular diseases. Detection of periodontopathogens, including red complex bacteria (RCB), in vascular lesions has suggested these bacteria to be involved in the pathogenesis of atherosclerosis and abdominal aortic aneurysms. Objective In this study, we investigate bacteria and their DNA in vascular biopsies from patients with vascular diseases (VD; i.e. abdominal aortic aneurysms, atherosclerotic carotid, and common femoral arteries), with and without CP. Methods DNA was extracted from vascular biopsies selected from 40 VD patients: 30 with CP and 10 without CP. The V3-V5 region of the 16S rDNA (V3-V5) was polymerase chain reaction (PCR)-amplified, and the amplicons were cloned into Escherichia coli, sequenced, and classified (GenBank and the Human Oral Microbiome database). Species-specific primers were used for the detection of Porphyromonas gingivalis. In addition, 10 randomly selected vascular biopsies from the CP group were subjected to scanning electron microscopy (SEM) for visualization of bacteria. Checkerboard DNA–DNA hybridization was performed to assess the presence of RCB in 10 randomly selected subgingival plaque samples from CP patients. Results A higher load and mean diversity of bacteria were detected in vascular biopsies from VD patients with CP compared to those without CP. Enterobacteriaceae were frequently detected in vascular biopsies together with cultivable, commensal oral, and not-yet-cultured bacterial species. While 70% of the subgingival plaque samples from CP patients showed presence of RCB, only P. gingivalis was detected in one vascular biopsy. Bacterial cells were seen in all 10 vascular biopsies examined by SEM. Conclusions A higher bacterial load and more diverse colonization were detected in VD lesions of CP patients as compared to patients without CP. This indicated that a multitude of bacterial species both from the gut and the

  14. Polymorphisms in the interleukin-10 gene and chronic periodontitis in patients with atherosclerotic and aortic aneurysmal vascular diseases

    PubMed Central

    Armingohar, Zahra; Jørgensen, Jørgen J.; Kristoffersen, Anne K.; Schenck, Karl; Dembic, Zlatko

    2015-01-01

    Background Chronic periodontitis (CP), atherosclerotic and aortic aneurysmal vascular diseases (VD) are chronic inflammatory conditions with multifactorial etiologies, including involvement of predisposing genetic factors. In a previous study, polymorphisms in the gene for the anti-inflammatory interleukin-1 receptor antagonist were associated with CP in patients with VD. Objective This study investigates whether polymorphisms in the gene for the anti-inflammatory interleukin-10 (IL10) could be related to CP in the same manner. Methods Seventy-two patients with VD of whom 35 had CP were genotyped for single nucleotide polymorphisms (SNPs) in the IL10 −592 (rs1800872), −819 (rs1800871), and −1,082 (rs1800896) gene by Taqman rtPCR method and by DNA sequencing. Results The C alleles and C/C genotypes of IL10 −592 and IL10 −819 frequencies were significantly higher, while the frequencies of the IL10 −592 (C/A) and IL10 −819 (C/T) heterozygote genotypes were significantly lower in the VD group with CP compared to those without CP. The IL10 haplotype ATA frequency (−1,082, −819, −592) showed a trend to a significant difference between the two groups indicating protection against CP. Conclusions Taken together, our findings suggest an independent association of genetic polymorphisms in the IL-10 gene locus with CP in patients with VD. Development of CP and the implications on vascular disease emphasize the importance of early detection and adequate treatment of periodontitis among these patients. PMID:25700628

  15. Analysis of proteins encoded in the bipartite genome of a new type of parvo-like virus isolated from silkworm - structural protein with DNA polymerase motif.

    PubMed

    Hayakawa, T; Kojima, K; Nonaka, K; Nakagaki, M; Sahara, K; Asano, S i; Iizuka, T; Bando, H

    2000-01-01

    Bombyx mori densonucleosis virus type 2 (BmDNV-2) is a small, spherical virus containing two complementary single-stranded linear DNA molecules (VD1, VD2). BmDNV-2 is a new type of virus with a unique, yet unspecified replication mechanism which is different from that of parvoviruses (Bando, H., Choi, H., Ito, Y., Nakagaki, M. , Kawase, S., 1992. Structural analysis on the single-stranded genomic DNAs of the virus newly isolated from silkworm: the DNA molecules share a common terminal sequence, Arch. Virol. 124, 187-193; Bando, H., Hayakawa, T., Asano, S., Sahara, K., Nakagaki, M. , Iizuka, T., 1995. Analysis of the genetic information of a DNA segment of a new virus from silkworm, Arch. Virol., 140, 1147-1155; Hayakawa, T., Asano, S., Sahara, K., Iizuka, T., Bando, H., 1997. Detection of replicative intermediate with closed terminus of Bombyx densonucleosis virus. Arch. Virol. 142, 1-7). Recent analyses on the genomic information of BmDNV-2 identified open reading frames which code for three tentative nonstructural proteins and four (VP1 to 4) of the six known structural proteins (Bando, H., Hayakawa, T., Asano, S., Sahara, K., Nakagaki, M., Iizuka, T., 1995. Analysis of the genetic information of a DNA segment of a new virus from silkworm, Arch. Virol., 140, 1147-1155; Nakagaki et al., in preparation). In this report we demonstrate that the two largest ORFs, VD1-ORF1 and VD2-ORF1, code for the two remaining structural proteins. In addition, computer-assisted analysis revealed that the structural protein encoded in VD1-ORF1 contains sequences conserved among various DNA polymerases, and showed an evolutionary relationship with the DNA polymerases involved in protein-primed replication.

  16. Hypergravity hinders axonal development of motor neurons in Caenorhabditis elegans

    PubMed Central

    Kalichamy, Saraswathi Subbammal; Yoon, Kyoung-hye

    2016-01-01

    As space flight becomes more accessible in the future, humans will be exposed to gravity conditions other than our 1G environment on Earth. Our bodies and physiology, however, are adapted for life at 1G gravity. Altering gravity can have profound effects on the body, particularly the development of muscles, but the reasons and biology behind gravity’s effect are not fully known. We asked whether increasing gravity had effects on the development of motor neurons that innervate and control muscle, a relatively unexplored area of gravity biology. Using the nematode model organism Caenorhabditis elegans, we examined changes in response to hypergravity in the development of the 19 GABAergic DD/VD motor neurons that innervate body muscle. We found that a high gravity force above 10G significantly increases the number of animals with defects in the development of axonal projections from the DD/VD neurons. We showed that a critical period of hypergravity exposure during the embryonic/early larval stage was sufficient to induce defects. While characterizing the nature of the axonal defects, we found that in normal 1G gravity conditions, DD/VD axonal defects occasionally occurred, with the majority of defects occurring on the dorsal side of the animal and in the mid-body region, and a significantly higher rate of error in the 13 VD axons than the 6 DD axons. Hypergravity exposure increased the rate of DD/VD axonal defects, but did not change the distribution or the characteristics of the defects. Our study demonstrates that altering gravity can impact motor neuron development. PMID:27833821

  17. Comparative study of van der Waals corrections to the bulk properties of graphite

    NASA Astrophysics Data System (ADS)

    Rêgo, Celso R. C.; Oliveira, Luiz N.; Tereshchuk, Polina; Da Silva, Juarez L. F.

    2015-10-01

    Graphite is a stack of honeycomb (graphene) layers bound together by nonlocal, long-range van der Waals (vdW) forces, which are poorly described by density functional theory (DFT) within local or semilocal exchange-correlation functionals. Several approximations have been proposed to add a vdW correction to the DFT total energies (Stefan Grimme (D2 and D3) with different damping functions (D3-BJ), Tkatchenko-Scheffler (TS) without and with self-consistent screening (TS  +  SCS) effects). Those corrections have remarkly improved the agreement between our results and experiment for the interlayer distance (from 3.8 to 0.1%) and high-level random-phase approximation (RPA) calculations for interlayer binding energy (from 56.2 to 0.6%). We report a systematic investigation of various structural, energetic and electron properties with the aforementioned vdW corrections followed by comparison with experimental and theoretical RPA data. Comparison between the resulting relative errors shows that the TS  +  SCS correction provides the best results; the other corrections yield significantly larger errors for at least one of the studied properties. If considerations of computational costs or convergence problems rule out the TS  +  SCS approach, we recommend the D3-BJ correction. Comparison between the computed {πz}Γ\\text{ } -splitting and experimental results shows disagreements of 10% or more with all vdW corrections. Even the computationally more expensive hybrid PBE0 has proved unable to improve the agreement with the measured splitting. Our results indicate that improvements of the exchange-correlation functionals beyond the vdW corrections are necessary to accurately describe the band structure of graphite.

  18. Comparative study of van der Waals corrections to the bulk properties of graphite.

    PubMed

    Rêgo, Celso R C; Oliveira, Luiz N; Tereshchuk, Polina; Da Silva, Juarez L F

    2015-10-21

    Graphite is a stack of honeycomb (graphene) layers bound together by nonlocal, long-range van der Waals (vdW) forces, which are poorly described by density functional theory (DFT) within local or semilocal exchange-correlation functionals. Several approximations have been proposed to add a vdW correction to the DFT total energies (Stefan Grimme (D2 and D3) with different damping functions (D3-BJ), Tkatchenko-Scheffler (TS) without and with self-consistent screening (TS  +  SCS) effects). Those corrections have remarkly improved the agreement between our results and experiment for the interlayer distance (from 3.9 to 0.6%) [corrected] and high-level random-phase approximation (RPA) calculations for interlayer binding energy (from 69.5 to 1.5%). [corrected]. We report a systematic investigation of various structural, energetic and electron properties with the aforementioned vdW corrections followed by comparison with experimental and theoretical RPA data. Comparison between the resulting relative errors shows that the TS  +  SCS correction provides the best results; the other corrections yield significantly larger errors for at least one of the studied properties. If considerations of computational costs or convergence problems rule out the TS  +  SCS approach, we recommend the D3-BJ correction. Comparison between the computed π(z)Γ-splitting and experimental results shows disagreements of 10% or more with all vdW corrections. Even the computationally more expensive hybrid PBE0 has proved unable to improve the agreement with the measured splitting. Our results indicate that improvements of the exchange-correlation functionals beyond the vdW corrections are necessary to accurately describe the band structure of graphite.

  19. Modulation of the partition coefficient between octanol and buffer at pH 7.4 and pKa to achieve the optimum balance of blood clearance and volume of distribution for a series of tetrahydropyran histamine type 3 receptor antagonists.

    PubMed

    Hay, Tanya; Jones, Rhys; Beaumont, Kevin; Kemp, Mark

    2009-09-01

    The relationship between rat pharmacokinetics and physicochemical parameters [the partition coefficient between octanol and buffer at pH 7.4 (log D((7.4))) and pK(a)] was studied for a series of tetrahydropyran compounds. Sixteen compounds ranging in log D((7.4)) 0.1 to 1.8 were administered intravenously to rats, and the pharmacokinetic parameters were determined from blood concentration time curves. Across the series, a weak correlation was observed between log D((7.4)) and blood clearance, suggesting that log D((7.4)) values less than 0.5 were required to prevent clearance at hepatic blood flow. In terms of the volume of distribution (V(d)), the compounds fell into three distinct subseries characterized by the number of basic centers and differences in ionization of each basic center at physiological pH. These were referred to as the monobasic, weak second base, and strong second base subseries. All the compounds exhibited V(d) greater than body water, as would be expected from their lipophilic and basic nature. For a given clog P, the strong second base subseries showed higher V(d) than the weak second base subseries, which in turn exhibited higher values than the monobasic subseries. In addition, for the weak second base subseries, V(d) could be tuned by modulating the pK(a) of the second basic center. This relationship was rationalized in respect to the interactions of the ionizable centers with phospholipid heads in the cell membrane and/or lysosomal trapping. Compounds in the weak second base subseries showed optimal V(d), and when combined with a log D((7.4)) of 0.1, driving to moderate blood clearance, one compound showed the optimal pharmacokinetic profile.

  20. Salutary effect of gastric pentadecapeptide BPC 157 in two different stress urinary incontinence models in female rats

    PubMed Central

    Jandric, Ivan; Vrcic, Hrvoje; Balen, Marica Jandric; Kolenc, Danijela; Brcic, Luka; Radic, Bozo; Drmic, Domagoj; Seiwerth, Sven; Sikiric, Predrag

    2013-01-01

    Background Since an originally anti-ulcer stable gastric pentadecapeptide BPC 157 (PL 14736) was shown to promote healing of injured striated muscle and smooth muscle in the gastrointestinal tract, we explored its therapeutic potentials for leak point pressure (LPP) recovery in rat stress urinary incontinence (SUI) after transabdominal urethrolysis (TU) and prolonged vaginal dilatation (VD). Material/Methods During a 7-day period, TU-rats and VD-rats (or healthy rats) received BPC 157, either (i) intraperitoneally, 10 μg/kg or 10 ng/kg, once daily (first administration 30 min after surgery, last 24 h before LPP-testing and sacrifice), or (ii) per-orally, 10 μg/kg in drinking water (0.16 μg/mL, 12 mL/rat/day). Vesicourethral segments were harvested for immunohistochemical evaluation. Results All BPC 157 regimens counteracted decrease of LPP values in TU-rats and VD-rats. Additionally, BPC 157-TU rats (μg-intraperitoneally or per-orally) and BPC 157-VD rats (μg intraperitoneally) reached LPP values originally noted in healthy rats. Conversely, in healthy rats, BPC 157 did not alter LPP. Immunohistochemical studies revealed higher desmin (delineates striated organization of skeletal muscle), smooth muscle actin, and CD34 (angiogenic marker) positivity within the urethral wall in BPC 157-treated rats vs. controls, as well as overall preserved muscle/connective tissue ratio assessed with Mallory’s trichrome staining. Conclusions Pentadecapeptide BPC 157, applied parenterally or per-orally, appears to ameliorate the SUI in rat models, improving the otherwise detrimental course of healing after VD and TU, which may be analogous to human injury. These beneficial effects may possibly be selectively used in future strategies for treatment of SUI. PMID:23478678

  1. Density, structure, and dynamics of water: the effect of van der Waals interactions.

    PubMed

    Wang, Jue; Román-Pérez, G; Soler, Jose M; Artacho, Emilio; Fernández-Serra, M-V

    2011-01-14

    It is known that ab initio molecular dynamics (AIMD) simulations of liquid water at ambient conditions, based on the generalized gradient approximation (GGA) to density functional theory (DFT), with commonly used functionals fail to produce structural and diffusive properties in reasonable agreement with experiment. This is true for canonical, constant temperature simulations where the density of the liquid is fixed to the experimental density. The equilibrium density, at ambient conditions, of DFT water has recently been shown by Schmidt et al. [J. Phys. Chem. B, 113, 11959 (2009)] to be underestimated by different GGA functionals for exchange and correlation, and corrected by the addition of interatomic pair potentials to describe van der Waals (vdW) interactions. In this contribution we present a DFT-AIMD study of liquid water using several GGA functionals as well as the van der Waals density functional (vdW-DF) of Dion et al. [Phys. Rev. Lett. 92, 246401 (2004)]. As expected, we find that the density of water is grossly underestimated by GGA functionals. When a vdW-DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections. We analyze the origin of the density differences between all the functionals. We show that the vdW-DF increases the population of non-H-bonded interstitial sites, at distances between the first and second coordination shells. However, it excessively weakens the H-bond network, collapsing the second coordination shell. This structural problem is partially associated to the choice of GGA exchange in the vdW-DF. We show that a different choice for the exchange functional is enough to achieve an overall improvement both in structure and diffusivity.

  2. Effectiveness of elcatonin for alleviating pain and inhibiting bone resorption in patients with osteoporotic vertebral fractures.

    PubMed

    Tanaka, Shinya; Yoshida, Akira; Kono, Shinjiro; Oguma, Tadanori; Hasegawa, Kyoichi; Ito, Manabu

    2016-11-09

    Elderly patients with osteoporotic vertebral fractures often experience severe pain that reduces their quality of life (QOL). Calcitonin, a bone resorption inhibitor, has been reported to alleviate pain in such patients; however, few clinical studies have demonstrated this effect. The objective of this study was to compare changes in pain scores, activities of daily living (ADL), QOL, bone resorption, bone mineral density (BMD), and fracture healing among patients with new vertebral fractures who received different treatment modalities. We conducted an open-label, multicenter, randomized, parallel control group study comprising 107 female patients ≥55 years old with acute back pain from vertebral fracture. All subjects received either intramuscular injections of elcatonin, a derivative of calcitonin, or an oral nonsteroidal antiinflammatory drug (NSAID) combined with an active vitamin D3 (VD3) analogue for 6 months. The pain was assessed using a visual analogue scale, and ADL and QOL were assessed using questionnaires. BMD was measured using dual-energy X-ray absorptiometry. A two-tailed significance level of 5% was used. The elcatonin IM group had significantly higher QOL score at 2 weeks and later, and significantly lower VAS and ADL scores than those in the NSAID + VD3 group at 1 month and later. The elcatonin IM group had significantly reduced TRACP-5b levels compared with those in the NSAID + VD3 group at 3 months and later and significantly higher percent changes in BMD than the NSAID + VD3 group. These results suggest that elcatonin significantly alleviated pain, inhibited bone resorption, and improved ADL, QOL, and BMD compared with NSAID + VD3.

  3. Atomic structure of metal-halide perovskites from first principles: The chicken-and-egg paradox of the organic-inorganic interaction

    NASA Astrophysics Data System (ADS)

    Li, Jingrui; Rinke, Patrick

    2016-07-01

    We have studied the prototype hybrid organic-inorganic perovskite CH3NH3PbI3 and its three close relatives, CH3NH3SnI3 ,CH3NH3PbCl3 , and CsPbI3, using relativistic density function theory. The long-range van der Waals (vdW) interactions were incorporated into the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional using the Tkatchenko-Scheffler pairwise scheme. Our results reveal that hydrogen bonding, which is well described by the PBE functional, plays a decisive role for the structural parameters of these systems, including the position and orientation of the organic cation as well as the deformation of the inorganic framework. The magnitude of the inorganic-framework deformation depends sensitively on the orientation of the organic cation, and directly influences the stability of the hybrid perovskites. Our results suggest that the organic and the inorganic components complement each other; the low symmetry of the organic cation is the origin of the inorganic-framework deformation, which then aids the overall stabilization of the hybrid perovskite structure. This stabilization is indirectly affected by vdW interactions, which lead to smaller unit-cell volumes than in PBE and therefore modulate the interaction between the organic cation and the inorganic framework. The vdW-induced lattice-constant corrections are system dependent and lead to PBE+vdW lattice constants in good agreement with experiment. Further insight is gained by analyzing the vdW contributions. In all iodide-based hybrid perovskites, the interaction between the organic cation and the iodide anions provides the largest lattice-constant change, followed by iodine-iodine and the organic cation—heavy-metal cation interaction. These corrections follow an almost linear dependence on the lattice constant within the range considered in our study and are therefore approximately additive.

  4. Electrochemical characterization of electrospun nanocomposite polymer blend electrolyte fibrous membrane for lithium battery.

    PubMed

    Padmaraj, O; Rao, B Nageswara; Venkateswarlu, M; Satyanarayana, N

    2015-04-23

    Novel hybrid (organic/inorganic) electrospun nanocomposite polymer blend electrolyte fibrous membranes with the composition poly(vinylidene difluoride-co-hexafluoropropylene) [P(VdF-co-HFP)]/poly(methyl methacrylate) [P(MMA)]/magnesium aluminate (MgAl2O4)/LiPF6 were prepared by the electrospinning technique. All of the prepared electrospun P(VdF-co-HFP), PMMA blend [90% P(VdF-co-HFP)/10% PMMA], and nanocomposite polymer blend [90% P(VdF-co-HFP)/10% PMMA/x wt % MgAl2O4 (x = 2, 4, 6, and 8)] fibrous membranes were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The fibrous nanocomposite separator-cum-polymer blend electrolyte membranes were obtained by soaking the nanocomposite polymer blend membranes in an electrolyte solution containing 1 M LiPF6 in ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1, v/v). The newly developed fibrous nanocomposite polymer blend electrolyte [90% P(VdF-co-HFP)/10% PMMA/6 wt % MgAl2O4/LiPF6] membrane showed a low crystallinity, low average fiber diameter, high thermal stability, high electrolyte uptake, high conductivity (2.60 × 10(-3) S cm(-1)) at room temperature, and good potential stability above 4.5 V. The best properties of the fibrous nanocomposite polymer blend electrolyte (NCPBE) membrane with a 6 wt % MgAl2O4 filler content was used for the fabrication of a Li/NCPBE/LiCoO2 CR 2032 coin cell. The electrochemical performance of the fabricated CR 2032 cell was evaluated at a current density of 0.1 C-rate. The fabricated CR 2032 cell lithium battery using the newly developed NCPBE membrane delivered an initial discharge capacity of 166 mAh g(-1) and a stable cycle performance.

  5. Comparison of carotid artery blood velocity measurements by vector and standard Doppler approaches.

    PubMed

    Tortoli, Piero; Lenge, Matteo; Righi, Daniele; Ciuti, Gabriele; Liebgott, Hervé; Ricci, Stefano

    2015-05-01

    Although severely affected by the angle dependency, carotid artery peak systolic velocity measurements are widely used for assessment of stenosis. In this study, blood peak systolic velocities in the common and internal carotid arteries of both healthy volunteers and patients with internal carotid artery stenosis were measured by two vector Doppler (VD) methods and compared with measurements obtained with the conventional spectral Doppler approach. Although the two VD techniques were completely different (using the transmission of focused beams and plane waves, respectively), the measurement results indicate that these techniques are nearly equivalent. The peak systolic velocities measured in 22 healthy common carotid arteries by the two VD techniques were very close (according to Bland-Altman analysis, the average difference was 3.2%, with limits of agreement of ± 8.6%). Application of Bland-Altman analysis to comparison of either VD technique with the spectral Doppler method provided a 21%-25% average difference with ± 13%-15% limits of agreement. Analysis of the results obtained from 15 internal carotid arteries led to similar conclusions, indicating significant overestimation of peak systolic velocity with the spectral Doppler method. Inter- and intra-operator repeatability measurements performed in a group of 8 healthy volunteers provided equivalent results for all of the methods (coefficients of variability in the range 2.7%-6.9%), even though the sonographers were not familiar with the VD methods. The results of this study suggest that the introduction of vector Doppler methods in commercial machines may finally be considered mature and capable of overcoming the angle-dependent overestimation typical of the standard spectral Doppler approach.

  6. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods.

  7. Two-dimensional GaSe/MoSe2 misfit bilayer heterojunctions by van der Waals epitaxy

    PubMed Central

    Li, Xufan; Lin, Ming-Wei; Lin, Junhao; Huang, Bing; Puretzky, Alexander A.; Ma, Cheng; Wang, Kai; Zhou, Wu; Pantelides, Sokrates T.; Chi, Miaofang; Kravchenko, Ivan; Fowlkes, Jason; Rouleau, Christopher M.; Geohegan, David B.; Xiao, Kai

    2016-01-01

    Two-dimensional (2D) heterostructures hold the promise for future atomically thin electronics and optoelectronics because of their diverse functionalities. Although heterostructures consisting of different 2D materials with well-matched lattices and novel physical properties have been successfully fabricated via van der Waals (vdW) epitaxy, constructing heterostructures from layered semiconductors with large lattice misfits remains challenging. We report the growth of 2D GaSe/MoSe2 heterostructures with a large lattice misfit using two-step chemical vapor deposition (CVD). Both vertically stacked and lateral heterostructures are demonstrated. The vertically stacked GaSe/MoSe2 heterostructures exhibit vdW epitaxy with well-aligned lattice orientation between the two layers, forming a periodic superlattice. However, the lateral heterostructures exhibit no lateral epitaxial alignment at the interface between GaSe and MoSe2 crystalline domains. Instead of a direct lateral connection at the boundary region where the same lattice orientation is observed between GaSe and MoSe2 monolayer domains in lateral GaSe/MoSe2 heterostructures, GaSe monolayers are found to overgrow MoSe2 during CVD, forming a stripe of vertically stacked vdW heterostructures at the crystal interface. Such vertically stacked vdW GaSe/MoSe2 heterostructures are shown to form p-n junctions with effective transport and separation of photogenerated charge carriers between layers, resulting in a gate-tunable photovoltaic response. These GaSe/MoSe2 vdW heterostructures should have applications as gate-tunable field-effect transistors, photodetectors, and solar cells. PMID:27152356

  8. Test of a nonempirical density functional: Short-range part of the van der Waals interaction in rare-gas dimers

    NASA Astrophysics Data System (ADS)

    Tao, Jianmin; Perdew, John P.

    2005-03-01

    It is known that the nonempirical generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE) provides a much more realistic description of the short-range part of the van der Waals (vdW) interaction than does the local spin density (LSD) approximation. In the present work, the ability of the higher-level nonempirical meta-GGA of Tao, Perdew, Staroverov, and Scuseria (TPSS) to describe vdW interaction is tested self-consistently in ten rare-gas dimers with Z ⩽36. The one-parameter hybrid version (TPSSh) of the TPSS exchange-correlation functional is also included in this test. Calculations show that both TPSS and TPSSh functionals correctly yield vdW bonds in these dimers and significantly improve the prediction of bond lengths, binding energies, and harmonic vibrational frequencies over LSD. The rather close agreement of TPSS with PBE for these dimers confirms a principle of the TPSS construction: preservation of the PBE large-gradient behavior. More importantly, it suggests that TPSS can serve as a platform on which to construct a still-higher level of nonempirical functionals. Compared with the PBE GGA, TPSS, and TPSSh yield a slightly weaker binding. As for normally bonded molecules, TPSSh yields the most accurate vibrational frequencies. The typically too-long bond lengths and too-small binding energies of TPSS meta-GGA suggest the need for some long-range vdW interaction correction even in this class of systems. The effect of basis-set superposition error on the calculated properties of these vdW systems is investigated. We also show that the relatively strong anharmonic effects in the rare-gas dimers are described remarkably well by the Morse potential.

  9. Application of van der Waals functionals to the calculation of dissociative adsorption of N2 on W(110) for static and dynamic systems

    NASA Astrophysics Data System (ADS)

    Migliorini, Davide; Nattino, Francesco; Kroes, Geert-Jan

    2016-02-01

    The fundamental understanding of molecule-surface reactions is of great importance to heterogeneous catalysis, motivating many theoretical and experimental studies. Even though much attention has been dedicated to the dissociative chemisorption of N2 on tungsten surfaces, none of the existing theoretical models has been able to quantitatively reproduce experimental reaction probabilities for the sticking of N2 to W(110). In this work, the dissociative chemisorption of N2 on W(110) has been studied with both static electronic structure and ab initio molecular dynamics (AIMD) calculations including the surface temperature effects through surface atom motion. Calculations have been performed using density functional theory, testing functionals that account for the long range van der Waals (vdW) interactions, which were previously only considered in dynamical calculations within the static surface approximation. The vdW-DF2 functional improves the description of the potential energy surface for N2 on W(110), returning less deep molecular adsorption wells and a better ratio between the barriers for the indirect dissociation and the desorption, as suggested by previous theoretical work and experimental evidence. Using the vdW-DF2 functional less trapping-mediated dissociation is obtained compared to results obtained with standard semi-local functionals such as PBE and RPBE, improving agreement with experimental data at Ei = 0.9 eV. However, at Ei = 2.287 and off-normal incidence, the vdW-DF2 AIMD underestimates the experimental reaction probabilities, showing that also with the vdW-DF2 functional the N2 on W(110) interaction is not yet described with quantitative accuracy.

  10. Risk factors for dementia in the epidemiological study of Munguialde County (Basque Country-Spain)

    PubMed Central

    Fernández Martínez, Manuel; Castro Flores, Jessica; Pérez de las Heras, Susana; Mandaluniz Lekumberri, Aitziber; Gordejuela Menocal, María; Zarranz Imirizaldu, Juan José

    2008-01-01

    Background Prevalence of degenerative dementias and dementias associated with cerebrovascular disease is increasing. Dementia is one of the most significant public health problem. In recent years, the role of vascular risk factors (hypertension, diabetes mellitus and hypercholesterolemia) and depression has been evaluated. The incidence of dementia and risk factors has not been fully investigated in Spain. The aim of this study was to identify the risk factors for dementia, Alzheimer's disease (AD) and vascular dementia (VD) in elderly people in Munguialde County (Spain). Methods A two phase, door-to-door populational study was performed. Demographic variables and the presence of vascular risk factors and depression were recorded. The MMSE, the DSM-IV and the conventional criteria for AD and VD were used in the evaluation. The odds ratio for each risk factor was calculated by logistic regression analysis. Results 1756 healthy subjects and 175 patients with dementia participated in the study. Of these, 133 had AD, 15 VD and the remainder other dementias. The risk factors for dementia and AD were female sex (OR = 1.67 and 1.97, respectively); age (OR = 1.14 and 1.15); stroke (OR = 7.84 and 3); and depression (OR = 53.08 and 3.19). Stroke was the only risk factor for VD (OR = 119). Conclusion Greater age, female sex, stroke and depression increase the risk of suffering dementia, AD and VD. The relationship between depression, vascular risk factors and dementia has clear public health implications. Prevention and early treatment of vascular risk factors and depression may have an important impact in lowering the risk of dementia and could modify the natural history of the disease. PMID:18922150

  11. Mechanisms of acetylcholine-mediated vasodilatation in young and aged human skin

    PubMed Central

    Holowatz, Lacy A; Thompson, Caitlin S; Minson, Christopher T; Kenney, W Larry

    2005-01-01

    Thermoregulatory cutaneous vasodilatation (VD) is attenuated in aged skin. While acetylcholine (ACh) plays a role in thermally mediated VD, the precise mechanisms through which ACh-mediated VD acts and whether those downstream mechanisms change with ageing are unclear. We tested the hypotheses that both nitric oxide (NO)- and prostanoid-mediated pathways contribute to exogenous ACh-mediated VD, and that both are attenuated with advanced age. Twelve young (Y: 23 ± 1 years) and 10 older (O: 69 ± 1 years) subjects underwent infusions of 137.5 μm ACh at four intradermal microdialysis sites: control (C, Ringer solution), NO synthase inhibited (NOS-I, 10 mml-NAME), cyclooxygenase inhibited (COX-I, 10 mm ketorolac) and NOS-I + COX-I. Red blood cell flux was monitored using laser-Doppler flowmetry, and cutaneous vascular conductance (CVC) was calculated (laser-Doppler flux/mean arterial pressure) and normalized to maximal CVC (%CVCmax) (28 mm sodium nitroprusside + local heating to 43°C). Baseline %CVCmax was increased in the O at COX-I sites (COX-I 16 ± 1, NOS-I + COX-I 16 ± 2 versus C 10 ± 1%CVCmax; P < 0.001) but not in the young, suggesting an age-related shift toward COX vasoconstrictors contributing to basal cutaneous vasomotor tone. There was no difference in peak %CVCmax during ACh infusion between age groups, and the response was unchanged by NOS-I (O: NOS-I 35 ± 5 versus C 38 ± 5%CVCmax; P = 0.84) (Y: NOS-I 41 ± 4 versus C 39 ± 4%CVCmax; P = 0.67). COX-I and NOS-I + COX-I attenuated the peak CVC response to ACh in both groups (COX-I O: 29 ± 3, Y: 22 ± 2%CVCmaxversus C; P < 0.001 both groups; NOS-I + COX-I O: 32 ± 3 versus Y: 29 ± 2%CVCmax; versus C; P < 0.001 both groups). ACh mediates cutaneous VD through prostanoid and non-NO-, non-prostanoid-dependent pathways. Further, older subjects have a diminished prostanoid contribution to ACh-mediated VD. PMID:15661816

  12. Vibrational dynamics of aniline(Ar)1 and aniline(CH4)1 clusters

    NASA Astrophysics Data System (ADS)

    Nimlos, M. R.; Young, M. A.; Bernstein, E. R.; Kelley, D. F.

    1989-11-01

    The first excited electronic state (S1) vibrational dynamics of aniline(Ar)1 and aniline(CH4)1 van der Waals (vdW) clusters have been studied using molecular jet and time resolved emission spectroscopic techniques. The rates of intramolecular vibrational energy redistribution (IVR) and vibrational predissociation (VP) as functions of vibrational energy are reported for both clusters. For vibrational energy in excess of the cluster binding energy, both clusters are observed to dissociate. The dispersed emission spectra of these clusters demonstrate that aniline(Ar)1 dissociates to all energetically accessible bare molecule states and that aniline(CH4)1 dissociates selectively to only the bare molecule vibrationless state. The emission kinetics show that in the aniline(Ar)1 case, the initially excited states have nanosecond lifetimes, and intermediate cluster states have very short lifetimes. In contrast, the initially excited aniline(CH4)1 states and other intermediate vibrationally excited cluster states are very short lived (<100 ps), and the intermediate cluster 00 state is observed. These results can be understood semiquantitatively in terms of an overall serial IVR/VP mechanism which consists of the following: (1) the rates of chromophore to vdW mode IVR are given by Fermi's golden rule, and the density of vdW vibrational states is the most important factor in determining the relative [aniline(Ar)1 vs aniline(CH4)1] rates of IVR; (2) IVR among the vdW modes is rapid; and (3) VP rates can be calculated by a restricted vdW mode phase space Rice-Ramsberger-Kassel-Marcus theory. Since the density of vdW states is three orders of magnitude greater for aniline(CH4)1 than aniline(Ar)1 at 700 cm-1, the model predicts that IVR is slow and rate limiting in aniline(Ar)1, whereas VP is slow and rate limiting in aniline(CH4)1. The agreement of these predictions with the experimental results is very good and is discussed in detail.

  13. Design and rationale of a multicentre, randomised, double-blind, placebo-controlled clinical trial to evaluate the effect of vitamin D on ventricular remodelling in patients with anterior myocardial infarction: the VITamin D in Acute Myocardial Infarction (VITDAMI) trial

    PubMed Central

    Tuñón, José; González-Hernández, Ignacio; Llanos-Jiménez, Lucía; Alonso-Martín, Joaquín; Escudier-Villa, Juan M; Tarín, Nieves; Cristóbal, Carmen; Sanz, Petra; Pello, Ana M; Aceña, Álvaro; Carda, Rocío; Orejas, Miguel; Tomás, Marta; Beltrán, Paula; Calero Rueda, Marta; Marcos, Esther; Serrano-Antolín, José María; Gutiérrez-Landaluce, Carlos; Jiménez, Rosa; Cabezudo, Jorge; Curcio, Alejandro; Peces-Barba, Germán; González-Parra, Emilio; Muñoz-Siscart, Raquel; González-Casaus, María Luisa; Lorenzo, Antonio; Huelmos, Ana; Goicolea, Javier; Ibáñez, Borja; Hernández, Gonzalo; Alonso-Pulpón, Luis M; Farré, Jerónimo; Lorenzo, Óscar; Mahíllo-Fernández, Ignacio; Egido, Jesús

    2016-01-01

    Introduction Decreased plasma vitamin D (VD) levels are linked to cardiovascular damage. However, clinical trials have not demonstrated a benefit of VD supplements on left ventricular (LV) remodelling. Anterior ST-elevation acute myocardial infarction (STEMI) is the best human model to study the effect of treatments on LV remodelling. We present a proof-of-concept study that aims to investigate whether VD improves LV remodelling in patients with anterior STEMI. Methods and analysis The VITamin D in Acute Myocardial Infarction (VITDAMI) trial is a multicentre, randomised, double-blind, placebo-controlled trial. 144 patients with anterior STEMI will be assigned to receive calcifediol 0.266 mg capsules (Hidroferol SGC)/15 days or placebo on a 2:1 basis during 12 months. Primary objective: to evaluate the effect of calcifediol on LV remodelling defined as an increase in LV end-diastolic volume ≥10% (MRI). Secondary objectives: change in LV end-diastolic and end-systolic volumes, ejection fraction, LV mass, diastolic function, sphericity index and size of fibrotic area; endothelial function; plasma levels of aminoterminal fragment of B-type natriuretic peptide, galectin-3 and monocyte chemoattractant protein-1; levels of calcidiol (VD metabolite) and other components of mineral metabolism (fibroblast growth factor-23 (FGF-23), the soluble form of its receptor klotho, parathormone and phosphate). Differences in the effect of VD will be investigated according to the plasma levels of FGF-23 and klotho. Treatment safety and tolerability will be assessed. This is the first study to evaluate the effect of VD on cardiac remodelling in patients with STEMI. Ethics and dissemination This trial has been approved by the corresponding Institutional Review Board (IRB) and National Competent Authority (Agencia Española de Medicamentos y Productos Sanitarios (AEMPS)). It will be conducted in accordance with good clinical practice (International Council for Harmonisation of

  14. Source Emission Testing of Hospital and Classified Waste Incinerators, Plattsburgh AFB, New York

    DTIC Science & Technology

    1988-07-01

    Gas volume Temperature Orifice Wet test Dry gas Wet test Dry Pas meter manometer meter r meter Inlet Outlet Avg- Time setting (VW), (Vd), (tW), ( td ... td ). ( td ), (), * (Ali), 1 3 FI O C-, in. H20 ft ft I min Oin. H2 0.5 5__ le 139 ’k. gj3 0 1.0 5 5IV.5 < /,0 -.. ~7 73C, ,-,.o • G 7- -3.o 6O 7.q P...Ir 1508, ?% ’ 𔄁,:;., 3.0 10 ..-- 33 4.00 1 z317 S35/ Avg AN, V Pb( td + 460) 0.0317 Al (t + 460) %n -. A H]c %’.Xt. -" YiAH @ t 460) V ,1 H20 T.- Vd

  15. Effect of van der Waals interactions on the chemisorption and physisorption of phenol and phenoxy on metal surfaces

    NASA Astrophysics Data System (ADS)

    Peköz, Rengin; Donadio, Davide

    2016-09-01

    The adsorption of phenol and phenoxy on the (111) surface of Au and Pt has been investigated by density functional theory calculations with the conventional PBE functional and three different non-local van der Waals (vdW) exchange and correlation functionals. It is found that both phenol and phenoxy on Au(111) are physisorbed. In contrast, phenol on Pt(111) presents an adsorption energy profile with a stable chemisorption state and a weakly metastable physisorbed precursor. While the use of vdW functionals is essential to determine the correct binding energy of both chemisorption and physisorption states, the relative stability and existence of an energy barrier between them depend on the semi-local approximations in the functionals. The first dissociation mechanism of phenol, yielding phenoxy and atomic hydrogen, has been also investigated, and the reaction and activation energies of the resulting phenoxy on the flat surfaces of Au and Pt were discussed.

  16. Differential voltage analyses of high-power, lithium-ion cells. 1. Technique and application

    NASA Astrophysics Data System (ADS)

    Bloom, Ira; Jansen, Andrew N.; Abraham, Daniel P.; Knuth, Jamie; Jones, Scott A.; Battaglia, Vincent S.; Henriksen, Gary L.

    The C/25 discharge data from 18650-size cells containing LiNi 0.8Co 0.1Al 0.1O 2 cathode and graphite anode laminates were analyzed through the use of the differential voltage, d V/d Q, curves. Using half-cell data, the peaks in the d V/d Q curve of the full cell data were assigned. Analysis of the relative peak shifts allowed for the determination of the source of capacity fade. For cells formed and aged at 45 °C for 40 weeks (capacity fade = 7.5%), the analysis indicated negligible loss of accessible material at the anode and at the cathode. Capacity loss of the cell could be accounted for, largely, by side reactions at the anode. This type of analysis can be used when the introduction of a reference electrode is difficult or impractical.

  17. Vastly enhancing the chemical stability of phosphorene by employing an electric field.

    PubMed

    Gao, Junfeng; Zhang, Gang; Zhang, Yong-Wei

    2017-03-23

    Currently, a major hurdle preventing phosphorene from various electronic applications is its rapid oxidation under ambient conditions. Thus how to enhance its chemical stability by suppressing oxidation becomes an urgent task. Here, we reveal a highly effective procedure to suppress the oxidation of phosphorene by employing a suitable van der Waals (vdW) substrate and a vertical electric field. Our first-principles study shows that the phosphorene-MoSe2 vdW heterostructure is able to reverse the stability of physisorption and chemisorption of molecular O2 on phosphorene. With further application of a vertical electric field of -0.6 V Å(-1), the energy barrier for oxidation is able to further increase to 0.91 eV, leading to a 10(5) times enhancement in its lifetime compared with that without using the procedure at room temperature. Our work presents a viable strategy to vastly enhance the chemical stability of phosphorene in air.

  18. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    SciTech Connect

    Liu, Fucai; You, Lu; Seyler, Kyle L.; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T.; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M.; Wang, Junling; Liu, Zheng

    2016-08-11

    In this study, two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ~320 K. Switchable polarization is observed in thin CIPS of ~4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ~100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.

  19. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    DOE PAGES

    Liu, Fucai; You, Lu; Seyler, Kyle L.; ...

    2016-08-11

    In this study, two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ~320 K. Switchable polarization is observed in thin CIPS of ~4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ~100. Themore » addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.« less

  20. Photocurrent measurements in Coupled Quantum Well van der Waals Heterostructures made of 2D Transition Metal Dichalcogenides

    NASA Astrophysics Data System (ADS)

    Joe, Andrew; Jauregui, Luis; High, Alex; Dibos, Alan; Gulpinar, Elgin; Pistunova, Kateryna; Park, Hongkun; Kim, Philip

    , Luis A. Jauregui, Alex A. High, Alan Dibos, Elgin Gulpinar, Kateryna Pistunova, Hongkun Park, Philip Kim Harvard University, Physics Department -abstract- Single layer transition metal dichalcogenides (TMDC) are 2-dimensional (2D) semiconductors van der Waals (vdW) characterized by a direct optical bandgap in the visible wavelength (~2 eV). Characterization of the band alignment between TMDC and the barrier is important for the fabrication of tunneling devices. Here, we fabricate coupled quantum well (CQW) heterostructures made of 2D TMDCs with hexagonal Boron nitride (hBN) as an atomically thin barrier and gate dielectric and with top and bottom metal (or graphite) as gate electrodes. We observe a clear dependence of the photo-generated current with varying hBN thickness, electrode workfunctions, electric field, laser excitation power, excitation wavelength, and temperature. We will discuss the implication of photocurrent in relation to quantum transport process across the vdW interfaces.

  1. Oxygen-assisted excitation of methyl iodide as a test of double spin-flip transition in van der Waals complex CH3I-O2

    NASA Astrophysics Data System (ADS)

    Bogomolov, Alexandr S.; Kochubei, Sergei A.; Baklanov, Alexey V.

    2016-09-01

    Photoexcitation of van der Waals (vdW) complex CH3I-O2 has been studied with velocity map imaging of I atoms arising in photodissociation. A new scheme of resonance-enhanced multiphoton ionization of iodine atoms has been applied with simultaneous use of UV and VIS radiation. The measured kinetic energy of I(2P3/2) atoms indicates photogeneration of precursor CH3I molecules via complex-specific channel with excitation energy expected for double spin-flip transition in complex CH3I-O2. The angular distribution for recoil directions of I(2P3/2) atoms coming from vdW complexes also corresponds to that expected for double spin-flip transition.

  2. High pressure phase transition in group III nitrides compounds

    NASA Astrophysics Data System (ADS)

    Soni, Shubhangi; Verma, S.; Kaurav, Netram; Choudhary, K. K.

    2016-05-01

    Using an effective interionic interaction potential (EIOP), the pressure induced structural phase transformation from ZnS-type (B3) to NaCl-type (B1) structure in group III Post-Transition Metal Nitrides [TMN; TM=Ga and Tl] were investigated. The long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach with modified ionic charge are properly incorporated in the EIOP. The vdW coefficients are computed following the Slater-Kirkwood variational method, as both the ions are polarizable. The estimated value of the phase transition pressure (Pt) and the magnitude of the discontinuity in volume at the transition pressure are consistent as compared to the reported data.

  3. Vibrational and thermal properties of β-HMX and TATB from dispersion corrected density functional theory

    NASA Astrophysics Data System (ADS)

    Landerville, Aaron C.; Oleynik, Ivan I.

    2017-01-01

    Dispersion Corrected Density Functional Theory (DFT+vdW) calculations are performed to predict vibrational and thermal properties of the bulk energetic materials (EMs) β-octahydrocyclotetramethylene-tetranitramine (β-HMX) and triaminotrinitrobenzene (TATB). DFT+vdW calculations of pressure-dependent crystal structure and the hydrostatic equation of state are followed by frozen-phonon calculations of their respective vibration spectra at each pressure. These are then used under the quasi-harmonic approximation to obtain zero-point and thermal free energy contributions to the pressure, resulting in pressure-volume-temperature (PVT) EOS for each material that are in excellent agreement with experiment. Heat capacities, and coefficients of thermal expansion as functions of temperature are also calculated and compared with experiment.

  4. Hydrogen peroxide modulates the dynamic microtubule cytoskeleton during the defence responses to Verticillium dahliae toxins in Arabidopsis.

    PubMed

    Yao, Lin-Lin; Zhou, Qun; Pei, Bao-Lei; Li, Ying-Zhang

    2011-09-01

    The molecular mechanisms of signal transduction of plants in response to infection by Verticillium dahliae (VD) are not well understood. We previously showed that NO may act as an upstream signalling molecule to trigger the depolymerization of cortical microtubules in Arabidopsis. In the present study, we used the wild-type, and atrbohD and atrbohF mutants of Arabidopsis to explore the mechanisms of action of H(2)O(2) signals and the dynamic microtubule cytoskeleton in defence responses. We demonstrated that H(2)O(2) may also act as an upstream signalling molecule to regulate cortical microtubule depolymerization. The depolymerization of the cortical microtubules played a functional role in the signalling pathway to mediate the expression of defence genes. The results indicate that H(2)O(2) modulates the dynamic microtubule cytoskeleton to trigger the expression of defence genes against V. dahliae toxins (VD-toxins) in Arabidopsis.

  5. [The autonomic regulation of the cardiovascular system in subjects with the autonomic dystonia syndrome subjected to ionizing radiation exposure as a result of the accident at the Chernobyl Atomic Electric Power Station].

    PubMed

    Niagu, A I; Zazimko, R N

    1995-01-01

    180 males in the age of 21-50, all the participants of Chernobyl accident consequences liquidation were examined. In all individuals vegetative dystonia (VD) syndrome was diagnosed (total radiation doses 0.1-1.0 Grey according to D. Erwin method). It was established that VD syndrome differed in these persons by pronounced stages of disorders manifestation as well as by polymorphism of vegetative disturbances. These findings testify central and peripheral vegetative nervous system parts involvement. In 40.2% of cases in individuals which were examined in rest and in 56.2% after dosed physical loading the functional disorders of vegetative cardiovascular system regulation of vagal type mainly (76.5%) were revealed. Clear correlation was not observed between vegetative disorders and radiation dose value. The estimation of contribution of each of the possible pathogenic factors (exactly stressogenic, radioactive and others) in vegetative disturbances development is not possible now.

  6. Radial Corrugations of Multi-Walled Carbon Nanotubes Driven by Inter-Wall Nonbonding Interactions.

    PubMed

    Huang, Xu; Liang, Wentao; Zhang, Sulin

    2011-12-01

    We perform large-scale quasi-continuum simulations to determine the stable cross-sectional configurations of free-standing multi-walled carbon nanotubes (MWCNTs). We show that at an inter-wall spacing larger than the equilibrium distance set by the inter-wall van der Waals (vdW) interactions, the initial circular cross-sections of the MWCNTs are transformed into symmetric polygonal shapes or asymmetric water-drop-like shapes. Our simulations also show that removing several innermost walls causes even more drastic cross-sectional polygonization of the MWCNTs. The predicted cross-sectional configurations agree with prior experimental observations. We attribute the radial corrugations to the compressive stresses induced by the excessive inter-wall vdW energy release of the MWCNTs. The stable cross-sectional configurations provide fundamental guidance to the design of single MWCNT-based devices and shed lights on the mechanical control of electrical properties.

  7. Prediction of radial breathing-like modes of double-walled carbon nanotubes with arbitrary chirality

    NASA Astrophysics Data System (ADS)

    Ghavanloo, Esmaeal; Fazelzadeh, S. Ahmad

    2014-10-01

    The radial breathing-like modes (RBLMs) of double-walled carbon nanotubes (DWCNTs) with arbitrary chirality are investigated by a simple analytical model. For this purpose, DWCNT is considered as double concentric elastic thin cylindrical shells, which are coupled through van der Waals (vdW) forces between two adjacent tubes. Lennard-Jones potential and a molecular mechanics model are used to calculate the vdW forces and to predict the mechanical properties, respectively. The validity of these theoretical results is confirmed through the comparison of the experimental results. Finally, a new approach is proposed to determine the diameters and the chiral indices of the inner and outer tubes of the DWCNTs with high precision.

  8. The Impact of Complex Forcing on the Viscous Torsional Vibration Damper's Work in the Crankshaft of the Rotating Combustion Engine

    NASA Astrophysics Data System (ADS)

    Jagiełowicz-Ryznar, C.

    2016-12-01

    The numerical calculations results of torsional vibration of the multi-cylinder crankshaft in the serial combustion engine (MC), including a viscous damper (VD), at complex forcing, were shown. In fact, in the MC case the crankshaft rotation forcings spectrum is the sum of harmonic forcing whose amplitude can be compared with the amplitude of the 1st harmonic. A significant impact, in the engine operational velocity, on the vibration damping process of MC, may be the amplitude of the 2nd harmonic of a forcing moment. The calculations results of MC vibration, depending on the amplitude of the 2nd harmonic of the forcing moment, for the first form of the torsional vibration, were shown. Higher forms of torsional vibrations have no practical significance. The calculations assume the optimum damping coefficient VD, when the simple harmonic forcing is equal to the base critical velocity of the MC crankshaft.

  9. Improved description of soft layered materials with van der Waals density functional theory.

    PubMed

    Graziano, Gabriella; Klimeš, Jiří; Fernandez-Alonso, Felix; Michaelides, Angelos

    2012-10-24

    The accurate description of van der Waals forces within density functional theory is currently one of the most active areas of research in computational physics and chemistry. Here we report results on the structural and energetic properties of graphite and hexagonal boron nitride, two layered materials where interlayer binding is dominated by van der Waals forces. Results from several density functionals are reported, including the optimized Becke88 van der Waals (optB88-vdW) and the optimized PBE van der Waals (optPBE-vdW) (Klimeš et al 2010 J. Phys.: Condens. Matter 22 022201) functionals. Where comparison to experiment and higher-level theory is possible, the results obtained from the two new van der Waals density functionals are in good agreement. An analysis of the physical nature of the interlayer binding in both graphite and hexagonal boron nitride is also reported.

  10. Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier.

    PubMed

    Liu, Yuanyue; Stradins, Paul; Wei, Su-Huai

    2016-04-01

    Two-dimensional (2D) semiconductors have shown great potential for electronic and optoelectronic applications. However, their development is limited by a large Schottky barrier (SB) at the metal-semiconductor junction (MSJ), which is difficult to tune by using conventional metals because of the effect of strong Fermi level pinning (FLP). We show that this problem can be overcome by using 2D metals, which are bounded with 2D semiconductors through van der Waals (vdW) interactions. This success relies on a weak FLP at the vdW MSJ, which is attributed to the suppression of metal-induced gap states. Consequently, the SB becomes tunable and can vanish with proper 2D metals (for example, H-NbS2). This work not only offers new insights into the fundamental properties of heterojunctions but also uncovers the great potential of 2D metals for device applications.

  11. Chemical free device fabrication of two dimensional van der Waals materials based transistors by using one-off stamping

    NASA Astrophysics Data System (ADS)

    Lee, Young Tack; Choi, Won Kook; Hwang, Do Kyung

    2016-06-01

    We report on a chemical free one-off imprinting method to fabricate two dimensional (2D) van der Waals (vdWs) materials based transistors. Such one-off imprinting technique is the simplest and effective way to prevent unintentional chemical reaction or damage of 2D vdWs active channel during device fabrication process. 2D MoS2 nanosheets based transistors with a hexagonal-boron-nitride (h-BN) passivation layer, prepared by one-off imprinting, show negligible variations of transfer characteristics after chemical vapor deposition process. In addition, this method enables the fabrication of all 2D MoS2 transistors consisting of h-BN gate insulator, and graphene source/drain and gate electrodes without any chemical damage.

  12. Radiation Dose-Volume Effects in the Stomach and Small Bowel

    SciTech Connect

    Kavanagh, Brian D.; Pan, Charlie C.; Dawson, Laura A.; Das, Shiva K.; Li, X. Allen; Ten Haken, Randall K.; Miften, Moyed

    2010-03-01

    Published data suggest that the risk of moderately severe (>=Grade 3) radiation-induced acute small-bowel toxicity can be predicted with a threshold model whereby for a given dose level, D, if the volume receiving that dose or greater (VD) exceeds a threshold quantity, the risk of toxicity escalates. Estimates of VD depend on the means of structure segmenting (e.g., V15 = 120 cc if individual bowel loops are outlined or V45 = 195 cc if entire peritoneal potential space of bowel is outlined). A similar predictive model of acute toxicity is not available for stomach. Late small-bowel/stomach toxicity is likely related to maximum dose and/or volume threshold parameters qualitatively similar to those related to acute toxicity risk. Concurrent chemotherapy has been associated with a higher risk of acute toxicity, and a history of abdominal surgery has been associated with a higher risk of late toxicity.

  13. Accurate van der Waals coefficients from density functional theory

    PubMed Central

    Tao, Jianmin; Perdew, John P.; Ruzsinszky, Adrienn

    2012-01-01

    The van der Waals interaction is a weak, long-range correlation, arising from quantum electronic charge fluctuations. This interaction affects many properties of materials. A simple and yet accurate estimate of this effect will facilitate computer simulation of complex molecular materials and drug design. Here we develop a fast approach for accurate evaluation of dynamic multipole polarizabilities and van der Waals (vdW) coefficients of all orders from the electron density and static multipole polarizabilities of each atom or other spherical object, without empirical fitting. Our dynamic polarizabilities (dipole, quadrupole, octupole, etc.) are exact in the zero- and high-frequency limits, and exact at all frequencies for a metallic sphere of uniform density. Our theory predicts dynamic multipole polarizabilities in excellent agreement with more expensive many-body methods, and yields therefrom vdW coefficients C6, C8, C10 for atom pairs with a mean absolute relative error of only 3%. PMID:22205765

  14. Tuning the Schottky barrier in the arsenene/graphene van der Waals heterostructures by electric field

    NASA Astrophysics Data System (ADS)

    Li, Wei; Wang, Tian-Xing; Dai, Xian-Qi; Wang, Xiao-Long; Ma, Ya-Qiang; Chang, Shan-Shan; Tang, Ya-Nan

    2017-04-01

    Using density functional theory calculations, we investigate the electronic properties of arsenene/graphene van der Waals (vdW) heterostructures by applying external electric field perpendicular to the layers. It is demonstrated that weak vdW interactions dominate between arsenene and graphene with their intrinsic electronic properties preserved. We find that an n-type Schottky contact is formed at the arsenene/graphene interface with a Schottky barrier of 0.54 eV. Moreover, the vertical electric field can not only control the Schottky barrier height but also the Schottky contacts (n-type and p-type) and Ohmic contacts (n-type) at the interface. Tunable p-type doping in graphene is achieved under the negative electric field because electrons can transfer from the Dirac point of graphene to the conduction band of arsenene. The present study would open a new avenue for application of ultrathin arsenene/graphene heterostructures in future nano- and optoelectronics.

  15. High-performance black phosphorus top-gate ferroelectric transistor for nonvolatile memory applications

    NASA Astrophysics Data System (ADS)

    Lee, Young Tack; Hwang, Do Kyung; Choi, Won Kook

    2016-10-01

    Two-dimensional (2D) van der Waals (vdW) atomic crystals have been extensively studied and significant progress has been made. The newest 2D vdW material, called black phosphorus (BP), has attracted considerable attention due to its unique physical properties, such as its being a singlecomponent material like graphene, and its having a high mobility and direct band gap. Here, we report on a high-performance BP nanosheet based ferroelectric field effect transistor (FeFET) with a poly(vinylidenefluoride-trifluoroethylene) top-gate insulator for a nonvolatile memory application. The BP FeFETs show the highest linear hole mobility of 563 cm2/Vs and a clear memory window of more than 15 V. For more advanced nonvolatile memory circuit applications, two different types of resistive-load and complementary ferroelectric memory inverters were implemented, which showed distinct memory on/off switching characteristics.

  16. Varroa destructor changes its cuticular hydrocarbons to mimic new hosts

    PubMed Central

    Le Conte, Y.; Huang, Z. Y.; Roux, M.; Zeng, Z. J.; Christidès, J.-P.; Bagnères, A.-G.

    2015-01-01

    Varroa destructor (Vd) is a honeybee ectoparasite. Its original host is the Asian honeybee, Apis cerana, but it has also become a severe, global threat to the European honeybee, Apis mellifera. Previous studies have shown that Varroa can mimic a host's cuticular hydrocarbons (HC), enabling the parasite to escape the hygienic behaviour of the host honeybees. By transferring mites between the two honeybee species, we further demonstrate that Vd is able to mimic the cuticular HC of a novel host species when artificially transferred to this new host. Mites originally from A. cerana are more efficient than mites from A. mellifera in mimicking HC of both A. cerana and A. mellifera. This remarkable adaptability may explain their relatively recent host-shift from A. cerana to A. mellifera. PMID:26041867

  17. Causes of Vitamin D Deficiency and Effect of Vitamin D Supplementation on Metabolic Complications in Obesity: a Review.

    PubMed

    Wamberg, Louise; Pedersen, Steen B; Rejnmark, Lars; Richelsen, Bjørn

    2015-12-01

    Obese subjects are often characterized by low plasma 25-hydroxy-vitamin D (25OHD) levels. Many explanations for this association have been proposed. Low plasma 25OHD is associated with obesity-related comorbidities such as insulin resistance, type 2 diabetes mellitus, and low-grade inflammation. In this review, we discuss the proposed mechanisms for low 25OHD in obesity and explore the results of recent RCTs on vitamin D (VD) supplementation on obesity and its metabolic complications such as insulin resistance and type 2 diabetes. Although the results from these clinical randomized controlled trials vary, the general picture is that VD treatment of obese individuals does not seem to be an effective treatment of obesity-related metabolic complications.

  18. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    NASA Astrophysics Data System (ADS)

    Liu, Fucai; You, Lu; Seyler, Kyle L.; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T.; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M.; Wang, Junling; Liu, Zheng

    2016-08-01

    Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ~320 K. Switchable polarization is observed in thin CIPS of ~4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ~100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity.

  19. Doping of carbon nanotubes with aluminum atom to improve Pt adsorption

    NASA Astrophysics Data System (ADS)

    Ganji, M. D.; Ahangari, M. Ghorbanzadeh; Khosravi, A.

    2014-01-01

    We implement the ab initio van der Waals (vdW) calculations at the density functional level of theory (vdW-DF) for the investigation of Pt adsorption ability of Al-doped carbon nanotubes (Al-CNTs). We present and discuss the energetically favorable sites for a single Pt atom adsorbed on the surface of Al-CNTs. Our results show significantly increment in the binding energy of Pt on the Al-CNT compared with pristine CNTs. We also find that Pt adsorption ability of Al-CNTs is more stronger than that of B- and N-doped CNTs. This is explained by the negative charges introduced in the neighboring C atoms by dopant atom. Our results verify that Al-doped CNTs seems to be more suitable materials for Pt adsorption than pure and also B- and N-doped CNTs.

  20. Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier

    PubMed Central

    Liu, Yuanyue; Stradins, Paul; Wei, Su-Huai

    2016-01-01

    Two-dimensional (2D) semiconductors have shown great potential for electronic and optoelectronic applications. However, their development is limited by a large Schottky barrier (SB) at the metal-semiconductor junction (MSJ), which is difficult to tune by using conventional metals because of the effect of strong Fermi level pinning (FLP). We show that this problem can be overcome by using 2D metals, which are bounded with 2D semiconductors through van der Waals (vdW) interactions. This success relies on a weak FLP at the vdW MSJ, which is attributed to the suppression of metal-induced gap states. Consequently, the SB becomes tunable and can vanish with proper 2D metals (for example, H-NbS2). This work not only offers new insights into the fundamental properties of heterojunctions but also uncovers the great potential of 2D metals for device applications. PMID:27152360

  1. Prediction of volume of distribution values in human using immobilized artificial membrane partitioning coefficients, the fraction of compound ionized and plasma protein binding data.

    PubMed

    Sui, Xiaofan; Sun, Jin; Li, Haiyan; Wang, Yongjun; Liu, Jianfang; Liu, Xiaohong; Zhang, Wenping; Chen, Lijiang; He, Zhonggui

    2009-11-01

    We developed an improved Lombardeo's method (J. Med. Chem., 2004) for prediction of VD(ss) in human. With ElogD substituted by logk(IAM), together with f(i (7.4)) (the fraction of compound ionized at pH 7.4) and logf(u) (logarithmic fraction of compound unbound in plasma), the predictive equation of f(ut) (the fraction of the compound unbound in tissues) for the 121 compounds was built, predictive VD(ss) was further obtained from the Øie-Tozer equation. Our model could be applicable to structurally diverse compounds, including acids, bases, neutrals, and ampholytes. Interior and exterior validation results indicated the model had a robust predictive ability. Compared to the Lombardeo's and Hollósy's (J. Med. Chem., 2006) methods, our model can be generally applicable with better predictive accuracy.

  2. Vacuum distillation/vapor filtration water recovery, phases 1 and 2

    NASA Technical Reports Server (NTRS)

    Honegger, R. J.; Remus, G. A.; Krug, E. K.

    1973-01-01

    The research is reported on the development of an evaporator for vacuum distillation/vapor filtration VD/VF water reclamation system for use on manned space flights. The design, fabrication, and tests of a six-man evaporator are described. It is concluded that: (1) A condenser with an internal rotating impeller and coolant surfaces directly opposite the condensing surfaces is an effective condenser. (2) The VD/VF evaporator, catalyst unit and condenser function satisfactorily based on thermal, mechanical and recovery performance during a 145-hour evaluation test. (3) The quality of recovered water, as measured by analyses for total organic carbon, pH, conductivity, turbidity, and viable bacteria density was within established limits for potability.

  3. Electronic structure and photoabsorption property of pseudocubic perovskites CH3NH3PbX3(X = I, Br) including van der Waals interaction

    NASA Astrophysics Data System (ADS)

    Yu, Chol-Jun; Jong, Un-Gi; Ri, Mun-Hyok; Ri, Gum-Chol; Pae, Yong-Hyon

    2016-11-01

    Using density functional theory with the inclusion of van der Waals (vdW) interaction, we have investigated electronic energy bands, density of states, effective masses of charge carriers, and photo absorption coefficients of pseudo-cubic CH$_3$NH$_3$PbX$_3$ (X=I, Br). Our results confirm the direct bandgap of 1.49 (1.92) eV for X=I (Br) in the pseudo-cubic $Pm$ phase with lattice constant of 6.324 (5.966) \\AA, being agreed well with experiment and indicating the necessity of vdW correction. The calculated photo absorption coefficients for X=I (Br) have the onset at red (orange) color and the first peak around violet (ultraviolet) color in overall agreement with the experiment.

  4. Electrostatic Equations for Large Scale Plasma Simulation Studies.

    DTIC Science & Technology

    1984-07-19

    iv i/Xj- v~d 1- vb)1X + g /X)I +L diSevb g/X) x~ 9 (7) and (~d v/X -vb Xv ) d v~ex0 Yn D ein en e + d bJ -X2 ~vd /X 2 + Svb X - +~ vbJ ~tXg + X -12~ d...ahIE x /B BV) +~{S~2~ven -s i~i/A + V(Se - S1)A - + S~fX) x(10) e4 e S Oi5 0-7 where S a e D -e .2£𔃼 sI = -D- (d e+ vbj 2 2= o/B AS v x2 + e en 1 VinJ

  5. Lattice Boltzmann Simulations for High Density Ratio Flows of Multiphase Fluids

    NASA Astrophysics Data System (ADS)

    Wei, Yikun; Qian, Yuehong

    2010-11-01

    In the present communication, we will show that the compression effect of the Redlich-Kwong equation of state(EOS) is lower than that of the van der Waals (vdW) EOS. The Redlich-Kwong equation of state has a better agreement with experimental data for the coexistence curve than the van derWaals (vdW) EOS. We implement the Redlich-Kwong EOS in the lattice Boltzmann simulations via a pseudo-potential. As a result, multi-phase flows with large density ratios may be simulated, thus many real applications in engineering problems can be applied. Acknowledgement: This research is supported in part by Ministry of Education in China via project IRT0844 and NSFC project 10625210 and Shanghai Sci and Tech. Com. Project 08ZZ43

  6. Radiographic evaluation of positional atelectasis in sedated dogs breathing room air versus 100% oxygen

    PubMed Central

    Barletta, Michele; Almondia, Donna; Williams, Jamie; Crochik, Sonia; Hofmeister, Erik

    2014-01-01

    This study documents the degree of positional atelectasis in sedated dogs receiving 100% oxygen (O2) versus room air. Initial lateral recumbency was determined by an orthopedic study and initial treatment (O2 or room air) was randomized. Each dog was maintained in lateral recumbency for 15 min, at which time ventrodorsal (VD) and opposite lateral thoracic radiographs were obtained. Each dog was then maintained in the opposite lateral recumbency and received the other treatment for 15 min, followed by a VD and opposite lateral radiograph. Radiographs were scored for severity of pulmonary pattern and mediastinal shift by 3 radiologists. Dogs breathing O2 had significantly higher scores than dogs breathing room air. If radiographically detectable dependent atelectasis is present, repeat thoracic images following manual positive ventilation and/or position change to the opposite lateral recumbency should be made to rule out the effect of O2 positional atelectasis and avoid misdiagnosis. PMID:25320389

  7. Giant vacuum forces via transmission lines

    NASA Astrophysics Data System (ADS)

    Shahmoon, Ephraim; Mazets, Igor; Kurizki, Gershon

    2015-03-01

    Quantum electromagnetic fluctuations induce forces between neutral particles, namely, the van der Waals (vdW) and Casimir interactions. Here we show that these fundamental interactions can be enhanced by many orders of magnitude upon changing the character of the mediating vacuum photon-modes. We consider two dipoles in the vicinity of any standard electric transmission line and find analytically that the interaction scales non-trivially with the inter-dipolar distance, resulting in a strong and long-range interaction. This may have profound implications on the non-additivity of vdW and Casimir interactions in many-particle systems, and opens the door for Casimir Physics in 1d. We discuss the possibilities of measuring this effect, e.g. in a coplanar waveguide line. In January 2015, my affiliation is supposed to change to ``Department of Physics, Harvard University.''

  8. Improving the accuracy of the nonlocal van der Waals density functional with minimal empiricism.

    PubMed

    Vydrov, Oleg A; Van Voorhis, Troy

    2009-03-14

    The nonlocal van der Waals density functional (vdW-DF) captures the essential physics of the dispersion interaction not only in the asymptotic regime but also for a general case of overlapping fragment densities. A balanced treatment of other energetic contributions, such as exchange, is crucial if we aim for accurate description of various properties of weakly bound systems. In this paper, the vdW-DF correlation functional is modified to make it better compatible with accurate exchange functionals. We suggest a slightly simplified construction of the nonlocal correlation, yielding more accurate asymptotic C(6) coefficients. We also derive a gradient correction, containing a parameter that can be adjusted to suit an exchange functional of choice. We devise a particularly apt combination of exchange and correlation terms, which satisfies many important constraints and performs well for our benchmark tests.

  9. Prolonged modification of action potential shape by synaptic inputs in molluscan neurones.

    PubMed

    Winlow, W

    1985-01-01

    1. Somatic action potentials of Lymnaea neurons are modified by excitatory or inhibitory synaptic inputs and have been studied using phase-plane techniques and an action potential duration monitor. 2. Excitatory synaptic inputs increase the rate of neuronal discharge, cause action potential broadening, a decrease in the maximum rate of depolarization (Vd) and a decrease in the maximum rate of repolarization (Vr). 3. Inhibitory synaptic inputs decrease the discharge rate and cause narrowing of action potentials, an increase in Vd and an increase in Vr. 4. The effects reported above outlast the original synaptic inputs by many seconds and, if the somatic action potentials are similar to those in the axon terminals, they may have far-reaching effects on transmitter release.

  10. Structural Changes in Alloys of the Al-Cu-Mg System Under Ion Bombardment and Shock-Wave Loading

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, V. V.; Gushchina, N. V.; Romanov, I. Yu.; Kaigorodova, L. I.; Grigor'ev, A. N.; Pavlenko, A. V.; Plokhoi, V. V.

    2017-02-01

    To confirm the hypothesis on the shock-wave nature of long-range effects upon corpuscular irradiation of condensed media presumably caused by emission and propagation of post-cascade shock waves, comparative experiments on ion beam modification and mechanical shock-wave loading of specimens of VD1 and D16 alloys of the Al-Cu-Mg system are performed. Direct analogy between the processes of microstructural change of cold-deformed VD1 and D16 alloys under mechanical shock loading and irradiation by beams of accelerated Ar+ ions (E = 20-40 keV) with low fluences (1015-1016 cm-2) is established. This demonstrates the important role of the dynamic long-range effects that have not yet been considered in classical radiation physics of solids.

  11. Room-temperature ferroelectricity in CuInP2S6 ultrathin flakes

    PubMed Central

    Liu, Fucai; You, Lu; Seyler, Kyle L.; Li, Xiaobao; Yu, Peng; Lin, Junhao; Wang, Xuewen; Zhou, Jiadong; Wang, Hong; He, Haiyong; Pantelides, Sokrates T.; Zhou, Wu; Sharma, Pradeep; Xu, Xiaodong; Ajayan, Pulickel M.; Wang, Junling; Liu, Zheng

    2016-01-01

    Two-dimensional (2D) materials have emerged as promising candidates for various optoelectronic applications based on their diverse electronic properties, ranging from insulating to superconducting. However, cooperative phenomena such as ferroelectricity in the 2D limit have not been well explored. Here, we report room-temperature ferroelectricity in 2D CuInP2S6 (CIPS) with a transition temperature of ∼320 K. Switchable polarization is observed in thin CIPS of ∼4 nm. To demonstrate the potential of this 2D ferroelectric material, we prepare a van der Waals (vdW) ferroelectric diode formed by CIPS/Si heterostructure, which shows good memory behaviour with on/off ratio of ∼100. The addition of ferroelectricity to the 2D family opens up possibilities for numerous novel applications, including sensors, actuators, non-volatile memory devices, and various vdW heterostructures based on 2D ferroelectricity. PMID:27510418

  12. Supercooling of Hydrogen on Template Materials to Deterministically Seed Ignition-Quality Solid Fuel Layers

    SciTech Connect

    Shin, S. J.; Zepeda-Ruiz, L. A.; Lee, J. R. I.; Baxamusa, S. H.

    2016-09-01

    In this study, we explored templating effects of various materials for hydrogen (H2 and D2) solidification by measuring the degree of supercooling required for liquid hydrogen to solidify below each triple point. The results show high supercooling (>100 mK) for most metallic, covalent, and ionic solids, and low supercooling (<100 mK) for van der Waals (vdW) solids. We attribute the low supercooling of vdW solids to the weak interaction of the substrate and hydrogen. Highly ordered pyrolytic graphite showed the lowest supercooling among materials that are solid at room temperature, but did not exhibit a templating effect within a fill-tube and capsule assembly.

  13. Supercooling of Hydrogen on Template Materials to Deterministically Seed Ignition-Quality Solid Fuel Layers

    DOE PAGES

    Shin, S. J.; Zepeda-Ruiz, L. A.; Lee, J. R. I.; ...

    2016-09-01

    In this study, we explored templating effects of various materials for hydrogen (H2 and D2) solidification by measuring the degree of supercooling required for liquid hydrogen to solidify below each triple point. The results show high supercooling (>100 mK) for most metallic, covalent, and ionic solids, and low supercooling (<100 mK) for van der Waals (vdW) solids. We attribute the low supercooling of vdW solids to the weak interaction of the substrate and hydrogen. Highly ordered pyrolytic graphite showed the lowest supercooling among materials that are solid at room temperature, but did not exhibit a templating effect within a fill-tubemore » and capsule assembly.« less

  14. Unraveling cellulose microfibrils: a twisted tale.

    PubMed

    Hadden, Jodi A; French, Alfred D; Woods, Robert J

    2013-10-01

    Molecular dynamics (MD) simulations of cellulose microfibrils are pertinent to the paper, textile, and biofuels industries for their unique capacity to characterize dynamic behavior and atomic-level interactions with solvent molecules and cellulase enzymes. While high-resolution crystallographic data have established a solid basis for computational analysis of cellulose, previous work has demonstrated a tendency for modeled microfibrils to diverge from the linear experimental structure and adopt a twisted conformation. Here, we investigate the dependence of this twisting behavior on computational approximations and establish the theoretical basis for its occurrence. We examine the role of solvent, the effect of nonbonded force field parameters [partial charges and van der Waals (vdW) contributions], and the use of explicitly modeled oxygen lone pairs in both the solute and solvent. Findings suggest that microfibril twisting is favored by vdW interactions, and counteracted by both intrachain hydrogen bonds and solvent effects at the microfibril surface.

  15. Structural and vibrational properties of α-MoO3 from van der Waals corrected density functional theory calculations

    NASA Astrophysics Data System (ADS)

    Ding, Hong; Ray, Keith G.; Ozolins, Vidvuds; Asta, Mark

    2012-01-01

    Structural and vibrational properties of α-MoO3 are studied employing two recently proposed methodologies for incorporating van der Waals (vdW) contributions in density functional theory (DFT) based calculations. The DFT-D2 [S. Grimme, J. Comput. Chem.JCCHDD0192-865110.1002/jcc.20495 27, 1787 (2006)] and optB88 vdW-DFT [J. Klimeš , J. Phys.: Condens. MatterPRBMDO0953-898410.1088/0953-8984/22/2/022201 22, 022201 (2010)] methods are shown to give rise to increased accuracy in predicted lattice parameters, relative to conventional DFT methods. Calculated vibrational frequencies agree with measurements to within 5% and 10% for modes involving bonded and nonbonded interactions in this compound, respectively.

  16. A crossover in anisotropic nanomechanochemistry of van der Waals crystals

    SciTech Connect

    Shimamura, Kohei; Misawa, Masaaki; Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Vashishta, Priya; Shimojo, Fuyuki

    2015-12-07

    In nanoscale mechanochemistry, mechanical forces selectively break covalent bonds to essentially control chemical reactions. An archetype is anisotropic detonation of layered energetic molecular crystals bonded by van der Waals (vdW) interactions. Here, quantum molecular dynamics simulations reveal a crossover of anisotropic nanomechanochemistry of vdW crystal. Within 10{sup −13} s from the passage of shock front, lateral collision produces NO{sub 2} via twisting and bending of nitro-groups and the resulting inverse Jahn-Teller effect, which is mediated by strong intra-layer hydrogen bonds. Subsequently, as we transition from heterogeneous to homogeneous mechanochemical regimes around 10{sup −12} s, shock normal to multilayers becomes more reactive, producing H{sub 2}O assisted by inter-layer N-N bond formation. These time-resolved results provide much needed atomistic understanding of nanomechanochemistry that underlies a wider range of technologies.

  17. Coherent Atom Optics with fast metastable rare gas atoms

    SciTech Connect

    Grucker, J.; Baudon, J.; Karam, J.-C.; Perales, F.; Vassilev, G.; Ducloy, M.; Bocvarski, V.

    2006-12-01

    Coherent atom optics experiments making use of an ultra-narrow beam of fast metastable atoms generated by metastability exchange are reported. The transverse coherence of the beam (coherence radius of 1.7 {mu}m for He*, 1.2 {mu}m for Ne*, 0.87 {mu}m for Ar*) is demonstrated via the atomic diffraction by a non-magnetic 2{mu}m-period reflection grating. The combination of the non-scalar van der Waals (vdW) interaction with the Zeeman interaction generated by a static magnetic field gives rise to ''vdW-Zeeman'' transitions among Zeeman sub-levels. Exo-energetic transitions of this type are observed with Ne*(3P2) atoms traversing a copper micro-slit grating. They can be used as a tunable beam splitter in an inelastic Fresnel bi-prism atom interferometer.

  18. Tunable Schottky contacts in the antimonene/graphene van der Waals heterostructures

    NASA Astrophysics Data System (ADS)

    Li, Wei; Wang, Xinlian; Dai, Xianqi

    2017-03-01

    Electronic structures modulation in the antimonene/graphene van der Waals(vdW) heterostructure with an external electric field(Eext) are investigated by density functional theory calculations. It is demonstrated that weak vdW interactions dominate between antimonene and graphene with their intrinsic electronic properties preserved. Furthermore, the vertical Eext can control not only the Schottky barrier but also the Schottky contacts (n-type and p-type) and Ohmic contacts (n-type) at the antimonene/graphene interface. Meanwhile, the negative Eext can shifts the Dirac point of graphene above the Fermi level, resulting in p-type doping in graphene because electrons can easily transfer from the Dirac point of graphene to the conduction band of antimonene. The present study would open a new avenue for application of ultrathin antimonene/graphene heterostructures in future nano- and optoelectronics.

  19. Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier

    DOE PAGES

    Liu, Yuanyue; Stradins, Paul; Wei, Su -Huai

    2016-04-22

    Two-dimensional (2D) semiconductors have shown great potential for electronic and optoelectronic applications. However, their development is limited by a large Schottky barrier (SB) at the metal-semiconductor junction (MSJ), which is difficult to tune by using conventional metals because of the effect of strong Fermi level pinning (FLP). We show that this problem can be overcome by using 2D metals, which are bounded with 2D semiconductors through van der Waals (vdW) interactions. This success relies on a weak FLP at the vdW MSJ, which is attributed to the suppression of metal-induced gap states. Consequently, the SB becomes tunable and can vanishmore » with proper 2D metals (for example, H-NbS2). This work not only offers new insights into the fundamental properties of heterojunctions but also uncovers the great potential of 2D metals for device applications.« less

  20. Van der Waals metal-semiconductor junction: Weak Fermi level pinning enables effective tuning of Schottky barrier

    SciTech Connect

    Liu, Yuanyue; Stradins, Paul; Wei, Su -Huai

    2016-04-22

    Two-dimensional (2D) semiconductors have shown great potential for electronic and optoelectronic applications. However, their development is limited by a large Schottky barrier (SB) at the metal-semiconductor junction (MSJ), which is difficult to tune by using conventional metals because of the effect of strong Fermi level pinning (FLP). We show that this problem can be overcome by using 2D metals, which are bounded with 2D semiconductors through van der Waals (vdW) interactions. This success relies on a weak FLP at the vdW MSJ, which is attributed to the suppression of metal-induced gap states. Consequently, the SB becomes tunable and can vanish with proper 2D metals (for example, H-NbS2). This work not only offers new insights into the fundamental properties of heterojunctions but also uncovers the great potential of 2D metals for device applications.

  1. 14 CFR Appendix G to Part 25 - Continuous Gust Design Criteria

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... selected. (ii) At speed VB: Uσ is equal to 1.32 times the values obtained under paragraph (b)(3)(i) of this... appendix. (iv) At speeds between VB and Vc and between Vc and VD: Uσ is equal to a value obtained by linear.... y=net value of the load or stress. Yone=g=value of the load or stress in one-g level flight....

  2. 14 CFR Appendix G to Part 25 - Continuous Gust Design Criteria

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... selected. (ii) At speed VB: Uσ is equal to 1.32 times the values obtained under paragraph (b)(3)(i) of this... appendix. (iv) At speeds between VB and Vc and between Vc and VD: Uσ is equal to a value obtained by linear.... y=net value of the load or stress. Yone=g=value of the load or stress in one-g level flight....

  3. 14 CFR Appendix G to Part 25 - Continuous Gust Design Criteria

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... selected. (ii) At speed VB: Uσ is equal to 1.32 times the values obtained under paragraph (b)(3)(i) of this... appendix. (iv) At speeds between VB and Vc and between Vc and VD: Uσ is equal to a value obtained by linear.... y=net value of the load or stress. Yone=g=value of the load or stress in one-g level flight....

  4. 14 CFR Appendix G to Part 25 - Continuous Gust Design Criteria

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... selected. (ii) At speed VB: Uσ is equal to 1.32 times the values obtained under paragraph (b)(3)(i) of this... appendix. (iv) At speeds between VB and Vc and between Vc and VD: Uσ is equal to a value obtained by linear.... y=net value of the load or stress. Yone=g=value of the load or stress in one-g level flight....

  5. 14 CFR Appendix G to Part 25 - Continuous Gust Design Criteria

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... selected. (ii) At speed VB: Uσ is equal to 1.32 times the values obtained under paragraph (b)(3)(i) of this... appendix. (iv) At speeds between VB and Vc and between Vc and VD: Uσ is equal to a value obtained by linear.... y=net value of the load or stress. Yone=g=value of the load or stress in one-g level flight....

  6. Reversible Tailoring of Mechanical Properties of Carbon Nanotube Forests by Immersing in Solvents

    DTIC Science & Technology

    2014-12-07

    Author’s personal copy Reversible tailoring of mechanical properties of carbon nanotube forests by immersing in solvents Parisa Pour Shahid Saeed...December 2013 Available online 7 December 2013 A B S T R A C T The mechanical behavior of carbon nanotube (CNT) forests soaked in three solvents – tol- uene...solvents, produces the lowest vdW forces between individual CNTs. Furthermore, wet–dry cycling of CNT forests shows the revers- ibility and

  7. Laser Doppler Experiments

    DTIC Science & Technology

    1992-06-19

    Spacer material: Zerodur , ULE or equivalent 3. Mirrors to be optically contacted to spacer 4. Mirror surfaces: matched to better than Vd120, after...the mechanical, optical and electronic design of the apparatus to date. The Contraves mount was fitted with new coude mirrors for the YAG laser; the...accuracy  MHz. The choice of mirror reflectances for the interferometer plates and the tolerance to be placed on the field of view have been

  8. Quantitative angiography during coronary angioplasty with a single angiographic view: a comparison of automated edge detection and videodensitometric techniques.

    PubMed

    Escaned, J; Foley, D P; Haase, J; Di Mario, C; Hermans, W R; de Feyter, P J; Serruys, P W

    1993-12-01

    Little information is available on the reliability of coronary luminal measurements obtained from quantitative analysis of a single angiographic view, an approach that is central to the practical use of on-line quantitative angiography. In the present study we investigated the contribution of two different techniques of quantitative angiography, edge detection (ED) and videodensitometry (VD), to the application of this concept during coronary angioplasty. Forty-six balloon angioplasty procedures were included in this study, all of them performed in a stenosis located in the mid right coronary segment. This coronary location was chosen to optimize data collection on luminal morphology and to minimize the number of factors that may adversely affect quantitative analysis with both techniques. In all cases two orthogonal angiographic projections were obtained before, after balloon dilatation, and at follow-up. Correlation coefficients and differences between orthogonal measurements obtained with each technique were used to evaluate the agreement between orthogonal readings at every stage of the procedure. The obtained correlation coefficients and mean differences (MD) between orthogonal measurements were as follows: before percutaneous transluminal coronary angiography (PTCA), 0.67 (MD 0.01 +/- 0.47 mm2) and 0.57 (MD 0.05 +/- 0.64 mm2) for ED and VD, respectively (Pitman's test for SD, p < 0.05); after balloon dilatation, 0.32 (MD -0.56 +/- 1.53 mm2) and 0.53 (MD -0.15 +/- 1.43 mm2) for ED and VD, respectively (paired t test for MD, p < 0.05); and at follow-up 0.79 (MD -0.15 +/- 0.97 mm2) and 0.73 (MD 0.17 +/- 1.16 mm2) for ED and VD, respectively (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Molecular Modeling of Energetic Materials: The Parameterization and Validation of Nitrate Esters in the COMPASS Force Field

    DTIC Science & Technology

    2000-11-01

    Lennard - Jones 9-6 function for the van der Waals (vdW) term and a Coulombic term for an electrostatic interaction. To validate the force field, molecular mechanics calculations and molecular dynamics simulations have been made on a variety of molecules containing the nitrate ester functionality. Using this force field, excellent agreement has been obtained between the calculated and experimental values for molecular structures, vibrational frequencies, liquid densities, heats of vaporization, crystal structure, mechanical properties and lattice

  10. Caffeine citrate treatment for extremely premature infants with apnea: population pharmacokinetics, absolute bioavailability, and implications for therapeutic drug monitoring.

    PubMed

    Charles, Bruce G; Townsend, Sarah R; Steer, Peter A; Flenady, Vicki J; Gray, Peter H; Shearman, Andrew

    2008-12-01

    The objective of this study was to develop a population model of the pharmacokinetics (PK) of caffeine after orogastric or intravenous administration to extremely premature neonates with apnea of prematurity who were to undergo extubation from ventilation. Infants of gestational age <30 weeks were randomly allocated to receive maintenance caffeine citrate dosing of either 5 or 20 mg/kg/d. Four blood samples were drawn at prerandomized times from each infant during caffeine treatment. Serum caffeine was assayed by enzyme-multiplied immunoassay technique. Concentration data (431 samples, median: 4 per subject) were obtained from 110 (52 male) infants of mean birth weight of 1009 g, current mean weight (WT) of 992 g, mean gestational age of 27.6 weeks, and mean postnatal age (PNA) of 12 days. Of 1022 doses given, 145 were orogastric, permitting estimation of absolute bioavailability. A 1-compartment model with first-order absorption was fitted to the data in NONMEM. Patient characteristics were screened (P < 0.01) in nested models for pharmacokinetic influence. Model stability was assessed by nonparametric bootstrapping. Clearance (CL) increased nonlinearly with increasing PNA, whereas volume of distribution (Vd) increased linearly with WT, according to the following allometric models: CL (L/h) = 0.167 (WT/70) (PNA/12); Vd (L) = 58.7 (WT/70). The mean elimination half-life was 101. Interindividual variability (IIV) of CL and Vd was 18.8 % and 22.3 %, respectively. Interoccasion variability (IOV) of CL and Vd was 35.1% and 11.1%, respectively. This study established that the elimination of caffeine was severely depressed in extremely premature infants but increased nonlinearly after birth up to age 6 weeks. Caffeine was completely absorbed, which has favorable implications for switching between intravenous and orogastric routes. The interoccasion variability about CL was twice the interindividual variability, which, among other factors, indicates that routine serum

  11. Effect of Processing Parameters on Reliability of VARTM/SCRIMP Composite Panels - Phase 1

    DTIC Science & Technology

    2007-07-01

    ASTM recommended three test methods for calculating the in-plane shear properties of the composite material ( ASTM D4762 , 2004). The tests were: the v...D3518M, 2001; ASTM D4255/D4255M, 2002). It was noted in the ASTM D4762 standard that the tensile test of [+45] laminate was limited to panels with...devised a standard guide for testing PMC materials ( ASTM D4762 , 2004). For characterizing the composite material compressive properties, the guide

  12. Photodissociation dynamics of the Kr-HBr cluster: the effect of the rare gas atom substitution.

    PubMed

    López-López, S; García-Vela, A

    2004-01-08

    The ultraviolet photolysis dynamics of Kr-HBr(v=0) is investigated by means of wave packet calculations, focusing on the fragmentation pathway Kr-HBr+ variant Planck's over 2pi omega-->H+Kr-Br. Photolysis is simulated by starting from two different cluster initial states, namely the ground van der Waals (vdW) and an excited vdW bending state, associated with the Kr-H-Br and Kr-Br-H isomers, respectively. The results show that, for the two initial states of the cluster, the Kr-Br product yield is lower than that of Ar-Br radicals found in previous studies on Ar-HBr photolysis. Despite this decrease, the Kr-Br yield is found to be still rather high, in particular for the initial excited vdW state of Kr-HBr(v=0). In addition, the Kr-Br product state distributions exhibit a remarkably higher excitation (mainly rotational) than the corresponding Ar-Br distributions. The lower yield and higher excitation of Kr-Br as compared to Ar-Br, are attributed to a larger share of the energy available for the radical going to internal excitation in the case of the Kr-Br product. The different partition of the energy available for Kr-Br also causes significant deviations in the photolysis behavior of Kr-HBr when compared to that of Ar-HBr, in the case of the initial excited vdW state of both clusters. A common feature of the photodissociation of Kr-HBr and Ar-HBr is the manifestation of quantum interference effects in the Kr-Br and Ar-Br rotational state distributions, in the form of pronounced structures of supernumerary rotational rainbows.

  13. van der Waals epitaxy of CdTe thin film on graphene

    NASA Astrophysics Data System (ADS)

    Mohanty, Dibyajyoti; Xie, Weiyu; Wang, Yiping; Lu, Zonghuan; Shi, Jian; Zhang, Shengbai; Wang, Gwo-Ching; Lu, Toh-Ming; Bhat, Ishwara B.

    2016-10-01

    van der Waals epitaxy (vdWE) facilitates the epitaxial growth of materials having a large lattice mismatch with the substrate. Although vdWE of two-dimensional (2D) materials on 2D materials have been extensively studied, the vdWE for three-dimensional (3D) materials on 2D substrates remains a challenge. It is perceived that a 2D substrate passes little information to dictate the 3D growth. In this article, we demonstrated the vdWE growth of the CdTe(111) thin film on a graphene buffered SiO2/Si substrate using metalorganic chemical vapor deposition technique, despite a 46% large lattice mismatch between CdTe and graphene and a symmetry change from cubic to hexagonal. Our CdTe films produce a very narrow X-ray rocking curve, and the X-ray pole figure analysis showed 12 CdTe (111) peaks at a chi angle of 70°. This was attributed to two sets of parallel epitaxy of CdTe on graphene with a 30° relative orientation giving rise to a 12-fold symmetry in the pole figure. First-principles calculations reveal that, despite the relatively small energy differences, the graphene buffer layer does pass epitaxial information to CdTe as the parallel epitaxy, obtained in the experiment, is energetically favored. The work paves a way for the growth of high quality CdTe film on a large area as well as on the amorphous substrates.

  14. Effect of audio and visual distraction on patients undergoing colonoscopy: a randomized controlled study

    PubMed Central

    De Silva, A. P.; Niriella, M. A.; Nandamuni, Y.; Nanayakkara, S. D.; Perera, K. R. P.; Kodisinghe, S. K.; Subasinghe, K. C. E.; Pathmeswaran, A.; de Silva, H. J.

    2016-01-01

    Background and study aims: Colonoscopy can cause anxiety and discomfort in patients. Sedation and analgesia as premedication can lead to complications in the elderly and those with comorbidities. This has led to an interest in the use of audio-visual distraction during the colonoscopy. We compared the effects of audio (AD) versus visual distraction (VD) in reducing discomfort and the need for sedation during colonoscopy. Patients and methods: Consecutive patients undergoing colonoscopy were randomized into three groups: one group was allowed to listen to the music of their choice (AD), the second group was allowed to watch a movie of their choice (VD), and the third group was not allowed either distraction during colonoscopy and acted as a control (C). Patient controlled analgesia and sedation were administered to all three groups. We used 25 mg of pethidine in 5-mg aliquots and 2.5 mg of midazolam in 0.5-mg aliquots. All patients were assessed for perceived pain and willingness to repeat the procedure. Number of “top-ups” of sedation and total dose of pethidine and midazolam were noted. Patient cooperation and ease of procedure were assessed by the colonoscopist. Results: In total, 200 patients were recruited [AD, n = 66 (32 males, median age 57 years); VD, n = 67 (43 males, median age 58 years); C, n = 67 (35 males, median age 59 years)]. The AD group had significantly less pain (P = 0.001), better patient cooperation (P = 0.001) and willingness to undergo a repeat procedure (P = 0.024) compared with VD and C groups. Conclusions: AD reduces pain and discomfort, improves patient cooperation and willingness to undergo a repeat procedure, and seems a useful, simple adjunct to low dose sedation during colonoscopy. Study registration: SLCTR/2014/031. PMID:27853748

  15. Epitaxial Growth of Molecular Crystals on van der Waals Substrates for High-Performance Organic Electronics

    DTIC Science & Technology

    2014-01-01

    but also to provide a less disruptive surface for the crystal growth. We employ vdW graphene electrodes that serve as an electrical contact [ 27,28...growth, chemical-vapor-deposited graphene fi lms were transferred onto the top of h-BN layers using the pre-patterned poly-dimethyl siloxane (PDMS...stamp [ 27 ] to create a lateral graphene /h-BN/ graphene heterostructure. During this transfer process, the h-BN surface over the channel region does

  16. Finite-temperature properties of nonmagnetic transition metals: Comparison of the performance of constraint-based semilocal and nonlocal functionals

    NASA Astrophysics Data System (ADS)

    Gharaee, Leili; Erhart, Paul; Hyldgaard, Per

    2017-02-01

    We assess the performance of nonempirical, truly nonlocal, and semilocal functionals with regard to structural and thermal properties of 3 d ,4 d , and 5 d nonmagnetic transition metals. We focus on constraint- based functionals and consider the consistent-exchange van der Waals density-functional version vdW-DF-cx [Phys. Rev. B 89, 035412 (2014), 10.1103/PhysRevB.89.035412], the semilocal PBE functional [Phys. Rev. Lett. 77, 3865 (1996), 10.1103/PhysRevLett.77.3865], and the PBEsol functional [Phys. Rev. Lett. 100, 136406 (2008), 10.1103/PhysRevLett.100.136406], as well as the AM05 metafunctional [Phys. Rev. B 72, 085108 (2005), 10.1103/PhysRevB.72.085108]. Using the quasiharmonic approximation, the structural parameters, elastic response, and thermal expansion at finite temperatures are computed and compared to experimental data. We also compute cohesive energies explicitly including zero-point vibrations. It is shown that overall vdW-DF-cx provides an accurate description of thermal properties and retains a level of transferability and accuracy that is comparable to or better than some of the best constraint-based semilocal functionals. Especially, with regard to the cohesive energies, the consistent inclusion of spin-polarization effects in the atoms turns out to be crucial, and it is important to use the rigorous spin-vdW-DF-cx formulation [Phys. Rev. Lett. 115, 136402 (2015), 10.1103/PhysRevLett.115.136402]. This demonstrates that vdW-DF-cx has general-purpose character and can be used to study systems that have both sparse and dense electron distributions.

  17. Different genotypes of Trypanosoma cruzi produce distinctive placental environment genetic response in chronic experimental infection.

    PubMed

    Juiz, Natalia Anahí; Solana, María Elisa; Acevedo, Gonzalo Raúl; Benatar, Alejandro Francisco; Ramirez, Juan Carlos; da Costa, Priscilla Almeida; Macedo, Andrea Mara; Longhi, Silvia Andrea; Schijman, Alejandro G

    2017-03-01

    Congenital infection of Trypanosoma cruzi allows transmission of this parasite through generations. Despite the problematic that this entails, little is known about the placenta environment genetic response produced against infection. We performed functional genomics by microarray analysis in C57Bl/6J mice comparing placentas from uninfected animals and from animals infected with two different T. cruzi strains: K98, a clone of the non-lethal myotropic CA-I strain (TcI), and VD (TcVI), isolated from a human case of congenital infection. Analysis of networks by GeneMANIA of differentially expressed genes showed that "Secretory Granule" was a pathway down-regulated in both infected groups, whereas "Innate Immune Response" and "Response to Interferon-gamma" were pathways up-regulated in VD infection but not in K98. Applying another approach, the GSEA algorithm that detects small changes in predetermined gene sets, we found that metabolic processes, transcription and macromolecular transport were down-regulated in infected placentas environment and some pathways related to cascade signaling had opposite regulation: over-represented in VD and down-regulated in K98 group. We also have found a stronger tropism to the placental organ by VD strain, by detection of parasite DNA and RNA, suggesting living parasites. Our study is the first one to describe in a murine model the genetic response of placental environment to T. cruzi infection and suggests the development of a strong immune response, parasite genotype-dependent, to the detriment of cellular metabolism, which may contribute to control infection preventing the risk of congenital transmission.

  18. Investigation of the range of validity of the pairwise summation method applied to the calculation of the surface roughness correction to the van der Waals force

    NASA Astrophysics Data System (ADS)

    Gusso, André; Burnham, Nancy A.

    2016-09-01

    It has long been recognized that stochastic surface roughness can considerably change the van der Waals (vdW) force between interacting surfaces and particles. However, few analytical expressions for the vdW force between rough surfaces have been presented in the literature. Because they have been derived using perturbative methods or the proximity force approximation the expressions are valid when the roughness correction is small and for a limited range of roughness parameters and surface separation. In this work, a nonperturbative approach, the effective density method (EDM) is proposed to circumvent some of these limitations. The method simplifies the calculations of the roughness correction based on pairwise summation (PWS), and allows us to derive simple expressions for the vdW force and energy between two semispaces covered with stochastic rough surfaces. Because the range of applicability of PWS and, therefore, of our results, are not known a priori, we compare the predictions based on the EDM with those based on the multilayer effective medium model, whose range of validity can be defined more properly and which is valid when the roughness correction is comparatively large. We conclude that the PWS can be used for roughness characterized by a correlation length of the order of its rms amplitude, when this amplitude is of the order of or smaller than a few nanometers, and only for typically insulating materials such as silicon dioxide, silicon nitride, diamond, and certain glasses, polymers and ceramics. The results are relevant for the correct modeling of systems where the vdW force can play a significant role such as micro and nanodevices, for the calculation of the tip-sample force in atomic force microscopy, and in problems involving adhesion.

  19. MHD-model for low-frequency waves in a tokamak with toroidal plasma rotation and problem of existence of global geodesic acoustic modes

    SciTech Connect

    Lakhin, V. P.; Sorokina, E. A. E-mail: vilkiae@gmail.com; Ilgisonis, V. I.; Konovaltseva, L. V.

    2015-12-15

    A set of reduced linear equations for the description of low-frequency perturbations in toroidally rotating plasma in axisymmetric tokamak is derived in the framework of ideal magnetohydrodynamics. The model suitable for the study of global geodesic acoustic modes (GGAMs) is designed. An example of the use of the developed model for derivation of the integral conditions for GGAM existence and of the corresponding dispersion relation is presented. The paper is dedicated to the memory of academician V.D. Shafranov.

  20. A Study of the Adjustment of Adopted Children in Air Force Families

    DTIC Science & Technology

    1988-01-01

    result from the adoptions. Supportive counseling could be helpful to these couples in their transition from a childless state to that of nurturing ...1. occasional 2. somewhat 3. very often nceer often Vd 12Y ju L 121 (15). Obesity or underweight: 0. rareJy or I. occasional 2. somewhat 3. very often...York: John Wiley & Sons. Erikson, E. H. (1980). Identity and the life cycle. New York: W. W. Norton. Erikson, E. H. (1985). Childhood and society

  1. A Model for Predicting Thermomechanical Response of Large Space Structures.

    DTIC Science & Technology

    1985-06-01

    mK -s- w~ FU Ms- +4i5 - WI --- I Cli FIG.1 (VdW) SMIS -4 u~r4 m ..,I - Im m m m m m U ) In m r~ _ _ _ m m A ’I Ii~ FIG. 2 ACKNOWLEDGEMENT The author...34 Texas A & M Mechanics and .Materials Center, IMM-4875-85-6, May 1985. [ 5 1 Allen. D. H. and Hausler , W. E., IfWedicted Temperature Field in a

  2. Self-consistent van der Waals density functional: Development and Applications

    NASA Astrophysics Data System (ADS)

    Cooper, Valentino

    2008-03-01

    The inability of density functional theory (DFT), with standard exchange-correlation functionals, to correctly describe van der Waals/dispersion (vdW) interactions has severely limited its applicability to sparsely packed systems, such as organic and biological molecules. Numerous attempts have been made to correct these deficiencies; however, many of them either require extensive reparameterization for each new situation or scale poorly with system size. In this paper, I will discuss the development and implementation of an exchange-correlation functional which correctly incorporates non-local vdW interactions within DFT (vdW-DF)ootnotetextM. Dion, H. Rydberg, E. Schröder, B. I. Lundqvist and D. C. Langreth, Phys. Rev. Lett., 92, 246401 (2004). In addition, I will present our recent development of the corresponding exchange- correlation potential (Vxc)ootnotetextT. Thonhauser, V. R. Cooper, S. Li, A. Puzder, P. Hyldgaard, and David C. Langreth, Phys. Rev. B, 76, 125112 (2007). The Vxc gives us the ability to compute Hellmann-Feynman forces, allowing for structural relaxations and molecular dynamics simulation. Using the Vxc I will examine the nature of the van der Waals bond between molecules. Finally, to demonstrate the power of the vdW-DF, I will discuss our relatively large scale application of the functional to study the influence of stacking interactions on the structure and stability of DNA. Here, I will show how these interactions are crucial for defining the twist and base pair separation in DNA and how methyl-nucleobase and methyl-methyl interactions give additional stability to DNA.

  3. The Relationship between Radiation Sensitivity and Redox Equilibria.

    DTIC Science & Technology

    1984-09-01

    highest concentration in our glasses are chlorine and hydrogen . Paramagnentic states arising from molecule ions or ions of these elements in glasses can...due to OH overtone absorptions and intrinsic (1) defect centers The removal of water from the sol-gel glasses , necessary to reduce the OH overtone...gels is independent of the water content of the initial solutions from which the VdCUUM " dried gels were produced. Fig. 2 shows the ESR-spectrum at

  4. Sustained low-efficiency dialysis in septic shock: Hemodynamic tolerability and efficacy

    PubMed Central

    Mishra, Shakti Bedanta; Singh, Ratender Kumar; Baronia, Arvind Kumar; Poddar, Banani; Azim, Afzal; Gurjar, Mohan

    2016-01-01

    Aim of the Study: Acute kidney injury (AKI) in septic shock has poor outcomes. Sustained low-efficiency dialysis (SLED) is increasingly replacing continuous renal replacement therapy as the preferred modality in Intensive Care Units (ICUs). However, the essential aspects of hemodynamic tolerability and efficacy of SLED in septic shock AKI has been minimally studied. Patients and Methods: We describe hemodynamic tolerability using modified vasopressor index (VI) and vasopressor dependency (VD) and efficacy using a combination of Kt/v, correction of acidosis, electrolyte, and fluid overload. Adult ICU patients of septic shock in AKI requiring SLED were included in this study. Results: One hundred and twenty-four patients of septic shock AKI requiring SLED were enrolled in the study. There were 74 nonsurvivors (NSs). Approximately, 56% (278/498) of the sessions in which vasopressors were required were studied. Metabolic acidosis (49%) was the predominant indication for the initiation of SLED in these patients. Baseline characteristics between survivors and NSs were comparable, except for age, severity scores, AKI stage, and coexisting illness. VI and VD prior to the initiation of SLED and delta VI and VD during SLED were significantly higher in NSs. Hemodynamic tolerability and efficacy of SLED was achievable only at lower vasopressor doses. Conclusion: VI, VD, and combination of Kt/v together with correction of acidosis, electrolyte, and fluid overload can be used to describe hemodynamic tolerability and efficacy of SLED in septic shock AKI. However, at higher vasopressor doses in septic shock, hemodynamic tolerability and efficacy of SLED requires further evidence. PMID:28149027

  5. Influence of long-term head-down body position on innervation density in extremity blood vessels

    NASA Technical Reports Server (NTRS)

    Lorant, M.; Raffai, G.; Nadasy, G.; Feher, E.; Monos, E.

    2001-01-01

    The aim of the present study was to quantitate and compare the density of nerve terminals (NTD), as well as of their synaptic vesicle population (SyVD) in saphenous and brachial vein and artery, obtained from rats maintained in the horizontal or head-down tilted (HDT) position for two weeks. The same technique was applied as that for the head-up tilt study.

  6. Impact of protective agents and drying methods on desiccation tolerance of Salix nigra L. seeds.

    PubMed

    Santagapita, Patricio R; Ott Schneider, Helena; Agudelo-Laverde, Lina M; Buera, M Pilar

    2014-09-01

    Willow seeds are classified as orthodox, but they show some recalcitrant characteristics, as they lose viability in a few weeks at room temperature. The aim of this work was to improve the desiccation tolerance of willow seeds (Salix nigra L.), as a model of sensitive materials to dehydration, through imbibition in solutions and later vacuum (VD) or freeze-drying (FD). Imbibition was conducted with 45% w/v trehalose or polyethylene glycol 400 -PEG- or water prior to dehydration treatments. Water- and especially trehalose-imbibed seeds subjected to VD showed better germination capability with respect to the freeze-dried ones. Water crystallization was mainly responsible for the great loss of capability germination observed in water- or trehalose-imbibed seeds subjected to FD. PEG behavior was better when seeds were FD instead of VD. DSC thermograms of seeds allowed to identify two thermal transitions corresponding to lipids melting and to proteins denaturation. This last transition reveals information about proteins state/functionality. Dehydration of control and PEG- or water-imbibed seeds affected proteins functionality leading to lower germinability. In the case of trehalose-imbibed seeds subjected to VD, proteins maintained their native state along dehydration, and the seeds showed a great germination capacity for all the water content range. Germinated seeds showed higher luminosity (L*), greenness (a*) and yellowness (b*) values than not-germinated seeds independently of the employed agent. Present work reveals that the presence of adequate protective agents as well the dehydration method were the main critical factors involved in willow seed desiccation tolerance.

  7. Laser System Reliability

    DTIC Science & Technology

    1977-03-01

    NEALE CAPT. RANDALL D. GODFREY CAPT. JOHN E. ACTON HR. DAVE B. LEMMING (ASD) :,^ 19 . ••^w**** SECTION III RELIABILITY PREDICTION...Dete Exchange Program) failure rate date bank. In addition, some data have been obtained from Hughes. Rocketdyne , Garrett, and the AFWL’s APT Failure...Central Ave, Suite 306, Albuq, NM 87108 R/M Systems, Inc (Dr. K. Blemel), 10801 Lomas 81vd NE, Albuquerque, NM 87112 Rocketdyne 01 v, Rockwell

  8. Free vibration of multiwall carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Wang, C. Y.; Ru, C. Q.; Mioduchowski, A.

    2005-06-01

    A multiple-elastic shell model is applied to systematically study free vibration of multiwall carbon nanotubes (MWNTs). Using Flugge [Stresses in Shells (Springer, Berlin, 1960)] equations of elastic shells, vibrational frequencies and associated modes are calculated for MWNTs of innermost radii 5 and 0.65 nm, respectively. The emphasis is placed on the effect of interlayer van der Waals (vdW) interaction on free vibration of MWNTs. Our results show that the interlayer vdW interaction has a crucial effect on radial (R) modes of large-radius MWNTs (e.g., of the innermost radius 5 nm), but is less pronounced for R modes of small-radius MWNTs (e.g., of the innermost radius 0.65 nm), and usually negligible for torsional (T) and longitudinal (L) modes of MWNTs. This is attributed to the fact that the interlayer vdW interaction, characterized by a radius-independent vdW interaction coefficient, depends on radial deflections only, and is dominant only for large-radius MWNTs of lower radial rigidity but less pronounced for small-radius MWNTs of much higher radial rigidity. As a result, the R modes of large-radius MWNTs are typically collective motions of almost all nested tubes, and the R modes of small-radius MWNTs, as well as the T and L modes of MWNTs, are basically vibrations of individual tubes. In particular, an approximate single-shell model is suggested to replace the multiple-shell model in calculating the lowest frequency of R mode of thin MWNTs (defined by the innermost radius-to-thickness ratio not less than 4) with relative errors less than 10%. In addition, the simplified Flugge single equation is adopted to substitute the exact Flugge equations in determining the R-mode frequencies of MWNTs with relative errors less than 10%.

  9. The use of geographical information systems for disaster risk reduction strategies: a case study of Volcan de Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Landeg, O.

    Contemporary disaster risk management requires the analysis of vulnerability and hazard exposure, which is imperative at Volcan de Colima (VdC), Mexico, due to the predicted, large-magnitude eruption forecast to occur before 2025. The methods used to gauge social vulnerability included the development and application of proxies to census records, the undertaking of a building vulnerability survey and the spatial mapping of civil and emergency infrastructure. Hazard exposure was assessed using primary modelling of laharic events and the digitalisation of secondary data sources detailing the modelled extent of pyroclastic flows and tephra deposition associated with a large-magnitude (VEI 5) eruption at VdC. The undertaking and analysis of a risk perception survey of the population enabled an understanding of the cognitive behaviour of residents towards the volcanic risk. In comparison to the published hazard map, the GIS analysis highlighted an underestimation of lahar hazard on the western flank of VdC and the regional tephra hazard. Vulnerability analysis identified three communities where social deprivation is relatively high, and those with significant elderly and transient populations near the volcano. Furthermore, recognition of the possibility of an eruption in the near future was found to be low across the study region. These results also contributed to the analysis of emergency management procedures and the preparedness of the regional authorities. This multidisciplinary research programme demonstrates the success of applying a GIS platform to varied integrative spatial and temporal analysis. Furthermore, ascertaining the impact of future activity at VdC upon its surrounding populations permits the evaluation of emergency preparedness and disaster risk reduction strategies.

  10. High Performance Crystalline Organic Transistors and Circuit

    DTIC Science & Technology

    2011-08-02

    first SiO Z OPentacene Au Pentacene ZrO2 AuPd SiO2 4 film. Bilayer dielectrics exhibit lower defect-related leakage effects, as pinholes or...OPVC P t Au SiO2 AuPd ZrO2 PVCn Pentacene 15 0 -1 -2 -3 -4 -5 0 -1 -2 -3 -4 -5 -6 -7 -2V -3V -4V I d (μ A ) Vd (V) -5V Figure 11: Output

  11. The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

    DOE PAGES

    Wang, Han; Bang, Junhyeok; Sun, Yiyang; ...

    2016-05-10

    Here, the success of van der Waals (vdW) heterostructures, made of graphene, metal dichalcogenides, and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that vdW heterostructues can exhibit ultra-fast charge transfer despite the weak binding of the heterostructure. Using time-dependent density functional theory molecular dynamics, we identify a strong dynamic coupling between the vdW layers associated with charge transfer. This dynamic coupling results in rapid nonlinear coherentmore » charge oscillations which constitute a purely electronic phenomenon and are shown to be a general feature of vdW heterostructures provided they have a critical minimum dipole coupling. Application to MoS2/WS2 heterostructure yields good agreement with experiment, indicating near complete charge transfer within a timescale of 100 fs.The success of van der Waals heterostructures made of graphene, metal dichalcogenides and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that van der Waals heterostructues can exhibit ultrafast charge transfer despite the weak binding of these heterostructures. Here we find, using time-dependent density functional theory molecular dynamics, that the collective motion of excitons at the interface leads to plasma oscillations associated with optical excitation. By constructing a simple model of the van der Waals heterostructure, we show that there exists an unexpected criticality of the oscillations, yielding rapid charge transfer across the

  12. The role of collective motion in the ultrafast charge transfer in van der Waals heterostructures

    SciTech Connect

    Wang, Han; Bang, Junhyeok; Sun, Yiyang; West, Damien; Meunier, Vincent; Zhang, Shengbai; Liang, Linagbo

    2016-05-10

    Here, the success of van der Waals (vdW) heterostructures, made of graphene, metal dichalcogenides, and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that vdW heterostructues can exhibit ultra-fast charge transfer despite the weak binding of the heterostructure. Using time-dependent density functional theory molecular dynamics, we identify a strong dynamic coupling between the vdW layers associated with charge transfer. This dynamic coupling results in rapid nonlinear coherent charge oscillations which constitute a purely electronic phenomenon and are shown to be a general feature of vdW heterostructures provided they have a critical minimum dipole coupling. Application to MoS2/WS2 heterostructure yields good agreement with experiment, indicating near complete charge transfer within a timescale of 100 fs.The success of van der Waals heterostructures made of graphene, metal dichalcogenides and other layered materials, hinges on the understanding of charge transfer across the interface as the foundation for new device concepts and applications. In contrast to conventional heterostructures, where a strong interfacial coupling is essential to charge transfer, recent experimental findings indicate that van der Waals heterostructues can exhibit ultrafast charge transfer despite the weak binding of these heterostructures. Here we find, using time-dependent density functional theory molecular dynamics, that the collective motion of excitons at the interface leads to plasma oscillations associated with optical excitation. By constructing a simple model of the van der Waals heterostructure, we show that there exists an unexpected criticality of the oscillations, yielding rapid charge transfer across the interface

  13. Objective Evaluation of Vergence Disorders and a Research-Based Novel Method for Vergence Rehabilitation

    PubMed Central

    Kapoula, Zoï; Morize, Aurélien; Daniel, François; Jonqua, Fabienne; Orssaud, Christophe; Brémond-Gignac, Dominique

    2016-01-01

    Purpose We performed video-oculography to evaluate vergence eye movement abnormalities in students diagnosed clinically with vergence disorders. We tested the efficiency of a novel rehabilitation method and evaluated its benefits with video-oculography cross-correlated with clinical tests and symptomatology. Methods A total of 19 students (20–27 years old) underwent ophthalmologic, orthoptic examination, and a vergence test coupled with video-oculography. Eight patients were diagnosed with vergence disorders with a high symptomatology score (CISS) and performed a 5-week session of vergence rehabilitation. Vergence and rehabilitation tasks were performed with a trapezoid surface of light emitting diodes (LEDs) and adjacent buzzers (US 8851669). We used a novel Vergence double-step (Vd-s) protocol: the target stepped to a second position before the vergence movement completion. Afterward the vergence test was repeated 1 week and 1 month later. Results Abnormally increased intertrial variability was observed for many vergence parameters (gain, duration, and speed) for the subjects with vergence disorders. High CISS scores were correlated with variability and increased latency. After the Vd-s, variability of all parameters dropped to normal or better levels. Moreover, the convergence and divergence latency diminished significantly to levels better than normal; benefits were maintained 1 month after completion of Vd-s. CISS scores dropped to normal level, which was maintained up to 1 year. Conclusions and Translational Relevance: Intertrial variability is the major marker of vergence disorders. The Vd-s research-based method leads to normalization of vergence properties and lasting removal of symptoms. The efficiency of the method is due to the spatiotemporal parameters of repetitive trials that stimulate neural plasticity. PMID:26981330

  14. Double-stranded RNA interferes in a sequence-specific manner with the infection of representative members of the two viroid families

    SciTech Connect

    Carbonell, Alberto; Martinez de Alba, Angel-Emilio Gago, Selma

    2008-02-05

    Infection by viroids, non-protein-coding circular RNAs, occurs with the accumulation of 21-24 nt viroid-derived small RNAs (vd-sRNAs) with characteristic properties of small interfering RNAs (siRNAs) associated to RNA silencing. The vd-sRNAs most likely derive from dicer-like (DCL) enzymes acting on viroid-specific dsRNA, the key elicitor of RNA silencing, or on the highly structured genomic RNA. Previously, viral dsRNAs delivered mechanically or agroinoculated have been shown to interfere with virus infection in a sequence-specific manner. Here, we report similar results with members of the two families of nuclear- and chloroplast-replicating viroids. Moreover, homologous vd-sRNAs co-delivered mechanically also interfered with one of the viroids examined. The interference was sequence-specific, temperature-dependent and, in some cases, also dependent on the dose of the co-inoculated dsRNA or vd-sRNAs. The sequence-specific nature of these effects suggests the involvement of the RNA induced silencing complex (RISC), which provides sequence specificity to RNA silencing machinery. Therefore, viroid titer in natural infections might be regulated by the concerted action of DCL and RISC. Viroids could have evolved their secondary structure as a compromise between resistance to DCL and RISC, which act preferentially against RNAs with compact and relaxed secondary structures, respectively. In addition, compartmentation, association with proteins or active replication might also help viroids to elude their host RNA silencing machinery.

  15. Analysis and Modeling for Thermal Focal Plane Arrays.

    DTIC Science & Technology

    1984-07-10

    or de- cision, unless so designated by other documentation., Tia docuirent a bci aj-2t1 vd kmr pWlj-? rohlus. -rd WJ0: its a esearch 2002 HOGBACK ...SCIENTIFIC & TECHNICAL REPORT paration FINAL TECHNICAL REPORT 2002 HOGBACK ROAD. SUITE 19 ANN ARBOR. MICHIGAN 48104 10 JULY 1984 CDRL A004 Accession For NTIS...PROGRAM ELEMENT. PROJECT. TASK AREA & WORK UNIT NUMBERS Nichols Research Corporation 2002 Hogback Road, Suite 19 Ann Arbor, MI 48104 .. 11

  16. Vesicles from pH-regulated reversible gemini amino-acid surfactants as nanocapsules for delivery.

    PubMed

    Lv, Jing; Qiao, Weihong; Li, Zongshi

    2016-10-01

    Reversible transition from micelles to vesicles by regulating pH were realized by gemini amino-acid surfactants N,N'-dialkyl-N,N'-diacetate ethylenediamine. Measurement results of ζ-potential at different pH and DLS at varying solvents revealed that the protonation between H(+) and double NCH2COO(-) groups (generating NH(+)CH2COO(-)), expressed as pKa1 and pKa2, is the key driving force to control the aggregation behaviors of gemini surfactant molecule. Effect of pH on the bilayer structure was studied in detail by using steady-state fluorescence spectroscopy of hydrophobic pyrene and Coumarin 153 (C153) respectively and fluorescence resonance energy transfer (FRET) from C153 to Rhodamine 6G (R6G). Various pH-regulated and pH-reversible self-assemblies were obtained in one surfactant system. Vitamin D3 was encapsulated in vesicle bilayers to form nano-VD3-capsules as VD3 supplement agent for health care products. By using the electrostatic attraction between Ca(2+) and double -COO(-) groups, nano-VD3-capsules with Ca(2+) coated outermost layers were prepared as a formulation for VD3 and calcium co-supplement agent. DLS and TEM were performed to check stability and morphology of the nano-capsules. It is concluded that the pH-regulated gemini amino-acid surfactants can be used to construct colloidal systems for delivering hydrophobic drugs or nutritions without lipids at human physiological pH level.

  17. JPRS Report, Epidemiology, Aids

    DTIC Science & Technology

    2007-11-02

    Dec 1990 panies in the country. MB1005145091 Lusaka Zambia National Broadcasting Mrs. Ntombela said the following behaviours are high Corporation...country are men in the sexually active age group of 20 to 40 years. Among factors associated with HIV infection are the history of a person’s sexually...run counter to socialism , and which caused VD to tries, and the Chinese people were seemingly unaffected become rampant. by it. At the most it was

  18. Effect of duloxetine, a norepinephrine and serotonin reuptake inhibitor, on sneeze-induced urethral continence reflex in rats.

    PubMed

    Miyazato, Minoru; Kaiho, Yasuhiro; Kamo, Izumi; Chancellor, Michael B; Sugaya, Kimio; de Groat, William C; Yoshimura, Naoki

    2008-07-01

    We investigated the effect of duloxetine, a norepinephrine (NE) and serotonin (5-HT) reuptake inhibitor, on the neurally evoked urethral continence reflex induced by sneezing in rats. To clarify the role of noradrenergic and serotonergic mechanisms in preventing stress urinary incontinence (SUI) during sneezing, we examined the effect of duloxetine followed by intrathecal (it) methiothepin maleate (5-HT receptor and alpha1-adrenoceptor antagonist) or terazosin or idazoxan (selective alpha1- and alpha2-adrenoceptor antagonists, respectively). Amplitude of urethral pressure responses during sneezing (A-URS), urethral baseline pressure (UBP) at the midurethra, and sneeze-induced leak point pressure (S-LPP) were measured in normal adult female rats and rats with SUI induced by vaginal distension (VD). In normal and VD rats, intravenous application of duloxetine (1 mg/kg) increased A-URS by 35% and 34% and UBP by 21% and 34%, respectively. Sneezing-induced fluid leakage from the urethral orifice was observed in VD rats but not in normal rats. S-LPP was increased from 39.1 to 92.2 cmH2O by intravenous duloxetine in incontinent VD rats. Duloxetine-mediated enhancement of A-URS was inhibited by terazosin but not methiothepin maleate (it). In addition, simultaneous intrathecal application of methiothepin and terazosin induced a reduction in A-URS during sneezing, which was not increased by intravenous duloxetine. However, the reduced A-URS after intrathecal application of methiothepin and terazosin returned to the control level when duloxetine (iv) was applied after intrathecal idazoxan administration. These results indicate that duloxetine can prevent SUI by facilitating noradrenergic and serotonergic systems in the spinal cord to enhance the sneeze-induced active urethral closure mechanism.

  19. Role of noradrenergic pathways in sneeze-induced urethral continence reflex in rats.

    PubMed

    Kaiho, Yasuhiro; Kamo, Izumi; Chancellor, Michael B; Arai, Yoichi; de Groat, William C; Yoshimura, Naoki

    2007-02-01

    To clarify the role of noradrenergic pathways in preventing stress urinary incontinence (SUI) during sneezing, we investigated the effect of the norepinephrine reuptake inhibitor nisoxetine and alpha-adrenoceptor antagonists phentolamine (nonspecific blocker) and prazosin (alpha(1)-receptor-selective blocker) on the neurally evoked urethral continence reflex induced by sneezing in rats. The amplitude of urethral pressure responses during sneezing (A-URS), urethral baseline pressure (UBP) at the midurethra, and sneeze-induced leak point pressure (S-LPP) were measured in normal female adult rats and rats with SUI induced by vaginal distention (VD). In normal rats, intrathecal (it) phentolamine (0.02 nmol) and prazosin (0.02 nmol) decreased A-URS by 11.9 and 15.7%, respectively, without affecting UBP. In both normal and VD rats, intravenous (iv) application of nisoxetine (1 mg/kg) increased A-URS by 17.2 and 18.3% and UBP by 23.7 and 32.7%, respectively. Phentolamine or prazosin (both it) eliminated nisoxetine-induced increases in A-URS, but not the increases in UBP, which were, however, suppressed by iv phentolamine (5 mg/kg) or prazosin (1 mg/kg). Sneezing induced fluid leakage from the urethral orifice in VD rats, but not in normal rats. In VD rats, S-LPP was increased by 30.2% by iv nisoxetine. Application of phentolamine and prazosin (both it) decreased S-LPP by 15.7 and 20.6%, respectively, and nisoxetine induced increases in S-LPP to 13.2 and 12.3%, respectively. These results indicate that activation of the noradrenergic system by a norepinephrine reuptake inhibitor can prevent SUI via alpha(1-)adrenoceptors by enhancing the sneeze-induced active urethral closure mechanism at the spinal level and augmenting UBP at the periphery.

  20. Clinical potential for vitamin D as a neoadjuvant for photodynamic therapy of nonmelanoma skin cancer

    NASA Astrophysics Data System (ADS)

    Maytin, Edward V.; Anand, Sanjay; Rollakanti, Kishore

    2015-03-01

    Nonmelanoma skin cancer (NMSC), comprising basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), is the most common form of human cancer worldwide. Effective therapies include surgical excision, cryotherapy, and ionizing radiation, but all of these cause scarring. ALA-based PDT is a non-scarring modality used routinely for NMSC in Europe but not in the USA, primarily due to lingering uncertainties about efficacy. We have identified three agents (methotrexate, 5-fluorouracil, and vitamin D) that can be used as neoadjuvants, i.e., can be given as a pretreatment prior to ALA-PDT, to improve the efficacy of tumor killing in mouse models of NMSC. Vitamin D (VD3) is the most recent neoadjuvant on this list. In this presentation we make the case that VD3 may be superior to the other agents to improve results of ALA-PDT skin cancer treatment. The active form of VD3 (calcitriol) is available topically as a pharmaceutical grade cream or ointment (FDA-approved for psoriasis), and works well for boosting ALA-PDT tumor treatment in mouse models. For deep tumors not reachable by a topical route, calcitriol can be given systemically and is very effective, but carries a risk of causing hypercalcemia as a side effect. To circumvent this risk, we have conducted experiments with the natural dietary form of VD3 (cholecalciferol), and showed that this improves ALA-PDT efficacy almost to the same extent as calcitriol. Because cholecalciferol does not increase serum calcium levels, this represents a potentially extremely safe approach. Data in mouse models of BCC and SCC will be presented.

  1. The potential of theragnostic 124I-8H9 convection-enhanced delivery in diffuse intrinsic pontine glioma

    PubMed Central

    Luther, Neal; Zhou, Zhiping; Zanzonico, Pat; Cheung, Nai-Kong; Humm, John; Edgar, Mark A.; Souweidane, Mark M.

    2014-01-01

    Background Reasons for failure in prior human glioma convection-enhanced delivery (CED) clinical trials remain unclear. Concentration-dependent volume of distribution (Vd) measurement of CED-infused agents in the human brain is challenging and highlights a potential technical shortcoming. Activity of iodine isotope 124 (124I ) in tissue can be directly measured in vivo with high resolution via PET. With the potential therapeutic utility of radioimmunotherapy, we postulate 124I conjugated to the antiglioma monoclonal antibody 8H9 may serve as a “theragnostic” agent delivered via CED to diffuse intrinsic pontine glioma. Methods Fifteen rats underwent CED of 0.1–1.0 mCi of 131I-8H9 to the pons for toxicity evaluation. Six additional rats underwent CED of 10 µCi of 124I-8H9 to the pons for dosimetry, with serial microPET performed for 1 week. Two primates underwent CED of gadolinium-albumin and 1.0 mCi of 124I-8H9 to the pons for safety and dosimetry analysis. Serial postoperative PET, blood, and CSF radioactivity counts were performed. Results One rat (1.0 mCi 131I-8H9 infusion) suffered toxicity necessitating early sacrifice. PET analysis in rats yielded a pontine absorbed dose of 37 Gy/mCi. In primates, no toxicity was observed, and absorbed pontine dose was 3.8 Gy/mCi. Activity decreased 10-fold with 48 h following CED in both animal models. Mean Vd was 0.14 cc3 (volume of infusion [Vi] to Vd ratio = 14) in the rat and 6.2 cc3 (Vd/Vi = 9.5) in primate. Conclusion The safety and feasibility of 124I dosimetry following CED via PET is demonstrated, establishing a preclinical framework for a trial evaluating CED of 124I-8H9 for diffuse intrinsic pontine glioma. PMID:24526309

  2. Adsorption of water and ethanol on noble and transition-metal substrates: a density functional investigation within van der Waals corrections.

    PubMed

    Freire, Rafael L H; Kiejna, Adam; Da Silva, Juarez L F

    2016-10-26

    We report the results of extensive computational investigation of the adsorption properties of water and ethanol on several Cu-, Pt-, and Au-based substrates, including the close-packed unreconstructed Cu(111), Pt(111), and Au(111) surfaces, defected metal substrates with on-surface low-coordinated sites generated by the intermixing of Pt-Cu and Pt-Au in the topmost surface layers and strained on-surface and sub-surface Pt-layers at Cu(111) and Au(111) substrates. The calculations are based on the density functional theory (DFT) within the van der Waals (vdW) correction. For all the substrates, we found that water and ethanol bind via the anionic O atom to the cationic one-fold coordinated on-top metal sites, which enhances the adsorbate-substrate Coulomb interactions. For water, both DFT and DFT + vdW calculations predict a flat geometry. For ethanol, the DFT and DFT + vdW results are in contrast, namely, DFT yields a perpendicular orientation of the C-C bond with respect to the surface, while we obtained a parallel orientation of the C-C bond using DFT + vdW, which maximizes the adsorption energies. Despite expected deviations due to the nature of the weak adsorbate-substrate interactions, we found that the adsorption energy of water and ethanol shows a linear dependence as a function of the position of the center of gravity of the occupied d-band, and hence, the magnitude of the adsorption energy increases as the d-band center position shifts towards the Fermi energy. Thus, it indicates hybridization between the O p- and metal d-states, which determines the magnitude of the adsorption energy of water and ethanol on clean, low-coordinated, and strained noble and transition-metal substrates.

  3. Retinoic acid cross-talk with calcitriol activity in Atlantic salmon (Salmo salar).

    PubMed

    Ørnsrud, R; Lock, E J; Glover, C N; Flik, G

    2009-09-01

    Vitamins A (VA) and D (VD) are metabolised by vertebrates to bioactive retinoic acid (RA) and calcitriol (CTR). RA and CTR involvement in bone metabolism requires fine-tuned regulation of their synthesis and breakdown. In mammals antagonism of VA and VD is observed, but the mechanism of interaction is unknown. We investigated VA-VD interactions in Atlantic salmon (Salmo salar L.) following i.p. injection of RA and/or CTR. VA metabolites, CTR, calcium (Ca), magnesium (Mg) and phosphorus (P) were determined in plasma. Expression of bone matrix Gla protein (mgp), collagen 1 alpha2 chain (col1a2) and alkaline phosphatase (alp) mRNA was quantified to reflect osteogenesis. Branchial epithelial Ca channel (ecac listed as trpv6 in ZFIN Database) mRNA levels and intestinal Ca and P influx were determined to study Ca/P handling targets of RA and CTR. RA-injection (with or without CTR) decreased plasma CTR-levels three- to sixfold. CTR injection did not affect RA metabolites, but lowered CTR in plasma 3 and 5 days after injection. Lowered plasma CTR correlated with decreased mgp and col1a2 expression in all groups and with decreased alp in CTR-injected fish. RA-treated salmon had enhanced alp expression, irrespective of reduced plasma CTR. Expression of ecac and unidirectional intestinal influx of Ca were stimulated following RA-CTR treatment. Plasma Ca, Mg and P were not affected by any treatment. The results suggest cross-talk of RA with the VD endocrine system in Atlantic salmon. Enhanced Ca flux and osteogenesis (alp transcription) in RA-treated fish and inhibition of mgp expression revealed unprecedented disturbance of Ca physiology in hypervitaminosis A.

  4. Robotic Tactile Sensor Fabricated from Piezoelectric Polyvinylidene Fluoride Films

    DTIC Science & Technology

    1988-12-01

    with IC Emphasis t ............ PVDF Film Thickness V ............ Volts Vbias ......... Bias Voltage Vdd .......... Amplifier Supply Voltage VdS... pressure sensitivity and coupling (mechanical and electrical) of several sensor configurations. The critical variables will be the PVDF film thickness and...the relative thinness of the films - (7:2.25-2.26). Despite these disadvantages, PVDF film has found its way into a myriad of applications because it

  5. Biochemical regulation of breast cancer cell expression of S1P2 (Edg-5) and S1P3 (Edg-3) G protein-coupled receptors for sphingosine 1-phosphate.

    PubMed

    Dolezalova, Hana; Shankar, Geetha; Huang, Mei-Chuan; Bikle, Daniel D; Goetzl, Edward J

    2003-03-01

    G protein-coupled receptors (GPCRs) for lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P) transduce signals to many functions of normal cells. Most human cancer cells upregulate S1P and LPA GPCRs, in patterns distinctive for each type of tumor. The findings that 1-alpha, 25-dihydroxy-vitamin D(3) (VD3) and all-trans retinoic acid (RA) differentially alter expression of the predominant S1P(3) (Edg-3) R and S1P(2) (Edg-5) R in human breast cancer cells (BCCs) permitted analyses of their individual activities, despite a lack of selective pharmacological probes. S1P-evoked increases in [Ca(2+)](i) in S1P(3) R-predominant BCCs were suppressed by concentrations of VD3 and RA which decreased expression of S1P(3) Rs, despite RA-induced increases in S1P(2) Rs. S1P-elicited chemokinetic migration of S1P(3) R-predominant BCCs across a type IV collagen-coated micropore filter also was inhibited by concentrations of VD3 and RA which decreased expression of S1P(3) Rs. The RA-induced increase in expression of S1P(2) Rs did not prevent suppression by RA of S1P-elicited chemokinesis, which appears to be mediated by S1P(3) Rs, but instead exposed S1P(2) R-mediated inhibition of epidermal growth factor-stimulated chemotaxis of BCCs. In contrast, expression of the predominant LPA(2) Rs, LPA-evoked increase in [Ca(2+)](i) and LPA-stimulated chemokinetic migration were suppressed concomitantly by RA but not VD3. Thus two structurally-homologous S1P Rs of BCCs differ in coupling to [Ca(2+)](i) signaling and have opposite effects on protein growth factor-stimulated chemotaxis.

  6. Effect of selective serotonin reuptake inhibitors on expression of 5-HT1AR and neurotransmitters in rats with vascular dementia.

    PubMed

    Guo, K; Yin, G; Zi, X H; Zhu, H X; Pan, Q

    2016-12-02

    5-hydroxytryptamine receptor 1A (5-HT1AR) is closely associated with cognitive functions. Selective serotonin reuptake inhibitors (SSRIs) can protect individuals from brain damage following ischemia/hypoxia. To investigate the function of SSRIs in vascular dementia (VD), we established a rat model of VD, and observed the effect of SSRIs on the expression of 5-HT1AR mRNA and neurotransmitters. Male SD rats (6 months) were randomly assigned into sham, model, and SSRI groups (N = 30). VD was achieved by permanent ligation of the bilateral common carotid artery. Escitalopram, a highly selective 5-HT reabsorption inhibitor, was ip injected into the rats for three consecutive weeks. The Morris water-maze was used to test learning and memory. H&E staining for neuronal injury was conducted on cortical and hippocampal tissues. HPLC was used to determine the levels of dopamine (DA), 5-HT, and norepinephrine (NE). RT-PCR was used to determine expression of 5-HT1AR mRNA. As compared to control rats, model animals demonstrated elongated escape latency, lower platform crossing times, and significant injuries to hippocampal CA1 neurons. This was accompanied by reductions in DA, 5-HT, and NE levels in hippocampal tissues, as well as reduced cortical 5-HT and decreased 5-HT1AR mRNA expression (P < 0.05). Escitalopram treatments reduced escape latency, elevated platform crossing times, improved CA1 neuronal damage, increased DA and 5-HT levels in hippocampal and cortical neurons, as well as elevated expression of 5-HT1AR mRNA (P < 0.05). Therefore, SSRIs may improve cognitive dysfunction of VD rats, possibly by stimulating expression of neurotransmitters and protecting neurons.

  7. The Effect of Saquinavir on the Rate of Metabolism of Midazolam

    DTIC Science & Technology

    1999-10-01

    margin of safety of a therapy ( Katzung , 1997). V max The maximal velocity of the biotransformation of a specific drug ( Katzung , 1997). Volume of...Distribution (Vd) The amount of drug present in the body in relation to the concentration of the drug in the plasma expressed in liters ( Katzung , 1997...Charlhant, D., Dreano, Y., Picart, D., Lohezic, F. & Riche, C. (1998). Drug Metabolism and Disposition, 26, 257-260. Katzung , B. (Ed.). (1998). Basic

  8. Timing in SWISSNET Specification, Development, Implementation and Operational Experience

    DTIC Science & Technology

    1989-11-01

    34Performance Aspects of Reference Clock D i s t r i b u t i o n f o r Evo lv ing D i g i t a l Networks", IEEE Communications Magazine , Vol . 27, No. 4...34 , IEEE communications Magazine , Vol . 27, No. 4, pp. 35-45, ( A p r i l 1989). C4I K* Hi l ty and P. Kartaschoff, PTT Report VD 22.001 A, 18

  9. Integrated Information Support System (IISS). Volume 8. User Interface Subsystem. Part 37. Layout Optimization System Development Specification

    DTIC Science & Technology

    1990-09-30

    line style to use for the connector and the form to use if the relation is complex, such as the IDEFIX generic relation. The existence of a complex...characters available for use in the stretchy line facility and their definition codes are: character code character code \\hs \\vs I \\vd .... \\ hd \\vu...example illustrates the use of stretchy line definitions to create a pictorial representation of an object. The object to be created is an IDEFIX

  10. Computations of Lifshitz-van der Waals interaction energies between irregular particles and surfaces at all separations for resuspension modelling

    NASA Astrophysics Data System (ADS)

    Priye, Aashish; Marlow, William H.

    2013-10-01

    The phenomenon of particle resuspension plays a vital role in numerous fields. Among many aspects of particle resuspension dynamics, a dominant concern is the accurate description and formulation of the van der Waals (vdW) interactions between the particle and substrate. Current models treat adhesion by incorporating a material-dependent Hamaker's constant which relies on the heuristic Hamaker's two-body interactions. However, this assumption of pairwise summation of interaction energies can lead to significant errors in condensed matter as it does not take into account the many-body interaction and retardation effects. To address these issues, an approach based on Lifshitz continuum theory of vdW interactions has been developed to calculate the principal many-body interactions between arbitrary geometries at all separation distances to a high degree of accuracy through Lifshitz's theory. We have applied this numerical implementation to calculate the many-body vdW interactions between spherical particles and surfaces with sinusoidally varying roughness profile and also to non-spherical particles (cubes, cylinders, tetrahedron etc) orientated differently with respect to the surface. Our calculations revealed that increasing the surface roughness amplitude decreases the adhesion force and non-spherical particles adhere to the surfaces more strongly when their flatter sides are oriented towards the surface. Such practical shapes and structures of particle-surface systems have not been previously considered in resuspension models and this rigorous treatment of vdW interactions provides more realistic adhesion forces between the particle and the surface which can then be coupled with computational fluid dynamics models to improve the predictive capabilities of particle resuspension dynamics.

  11. Delivery quality assurance with ArcCHECK

    SciTech Connect

    Neilson, Christopher; Klein, Michael; Barnett, Rob; Yartsev, Slav

    2013-04-01

    Radiation therapy requires delivery quality assurance (DQA) to ensure that treatment is accurate and closely follows the plan. We report our experience with the ArcCHECK phantom and investigate its potential optimization for the DQA process. One-hundred seventy DQA plans from 84 patients were studied. Plans were classified into 2 groups: those with the target situated on the diodes of the ArcCHECK (D plans) and those with the target situated at the center (C plans). Gamma pass rates for 8 target sites were examined. The parameters used to analyze the data included 3%/3 mm with the Van Dyk percent difference criteria (VD) on, 3%/3 mm with the VD off, 2%/2 mm with the VD on, and x/3 mm with the VD on and the percentage dosimetric agreement “x” for diode plans adjusted. D plans typically displayed maximum planned dose (MPD) on the cylindrical surface containing ArcCHECK diodes than center plans, resulting in inflated gamma pass rates. When this was taken into account by adjusting the percentage dosimetric agreement, C plans outperformed D plans by an average of 3.5%. ArcCHECK can streamline the DQA process, consuming less time and resources than radiographic films. It is unnecessary to generate 2 DQA plans for each patient; a single center plan will suffice. Six of 8 target sites consistently displayed pass rates well within our acceptance criteria; the lesser performance of head and neck and spinal sites can be attributed to marginally lower doses and increased high gradient of plans.

  12. Different genotypes of Trypanosoma cruzi produce distinctive placental environment genetic response in chronic experimental infection

    PubMed Central

    Juiz, Natalia Anahí; Solana, María Elisa; Acevedo, Gonzalo Raúl; Benatar, Alejandro Francisco; Ramirez, Juan Carlos; da Costa, Priscilla Almeida; Macedo, Andrea Mara; Longhi, Silvia Andrea

    2017-01-01

    Congenital infection of Trypanosoma cruzi allows transmission of this parasite through generations. Despite the problematic that this entails, little is known about the placenta environment genetic response produced against infection. We performed functional genomics by microarray analysis in C57Bl/6J mice comparing placentas from uninfected animals and from animals infected with two different T. cruzi strains: K98, a clone of the non-lethal myotropic CA-I strain (TcI), and VD (TcVI), isolated from a human case of congenital infection. Analysis of networks by GeneMANIA of differentially expressed genes showed that “Secretory Granule” was a pathway down-regulated in both infected groups, whereas “Innate Immune Response” and “Response to Interferon-gamma” were pathways up-regulated in VD infection but not in K98. Applying another approach, the GSEA algorithm that detects small changes in predetermined gene sets, we found that metabolic processes, transcription and macromolecular transport were down-regulated in infected placentas environment and some pathways related to cascade signaling had opposite regulation: over-represented in VD and down-regulated in K98 group. We also have found a stronger tropism to the placental organ by VD strain, by detection of parasite DNA and RNA, suggesting living parasites. Our study is the first one to describe in a murine model the genetic response of placental environment to T. cruzi infection and suggests the development of a strong immune response, parasite genotype-dependent, to the detriment of cellular metabolism, which may contribute to control infection preventing the risk of congenital transmission. PMID:28273076

  13. Views of Medical Physics in the United Kingdom and Ireland, 1980.

    DTIC Science & Technology

    1981-05-19

    scientific personnel and contractors. It is not considered part of the scien- tific literatur, and should not be cited as such. APPW=VD FOR PUBLIC...cervix. At the General Infirmary, duties of the Medical Physics department include both teaching and research. Being a part of the hospital, the...the use of w- mesons for radiotherapy. There will be a n- meson beam as part of the new spallation neutron source at the Rutherford Laboratory. The

  14. B-1B Avionics Systems AFSC 457X3

    DTIC Science & Technology

    1992-01-01

    maintaining the auto flight control system (autopilot), various sensors, and computers. These airmen report spending 73 percent of their time...LU -uj LUJ >- LUJO I- ~cr L") Of0C) -- => -j -i L/) Vd) LUL d.J ’-4 -j - ’_4 _’-_ LU I- I - LUJ 4-41 LU ’-- Ji~ la- 0-4 V)0 cl LLJ Ci Ur- Ll LU) DrD 3

  15. Particle Deposition onto Enclosure Surfaces

    DTIC Science & Technology

    2009-08-20

    Rate, P 16 4.3 Comparison of vd and fi 16 5. Methods for Measurement of Particle Deposition 19 5.1 Measuring Particle Deposition Rate, p 19...deposition. 18 5. Methods for Measurement of Particle Deposition Owing to its importance for numerous engineering systems, the processes of particle...particle counter, time-of-flight aerosol spectrometer, electrical aerosol mobility analyzer, as well as aerosol generation methods , can be found in

  16. Innate and Adaptive Immune Responses Both Contribute to Pathological CD4 T Cell Activation in HIV-1 Infected Ugandans

    DTIC Science & Technology

    2011-04-01

    Matud JL, Yamashita TE, Mellors JW, et al. (2002) Predictive value of immunologic and virologic markers after long or short duration of HIV-1...of AIDS. Annu Rev Med 60: 471–484. 10. Gonzalez VD, Landay AL, Sandberg JK (2010) Innate immunity and chronic immune activation in HCV /HIV-1 co...rescues the proliferative response of simian immunodeficiency virus-specific CD4 and CD8 T cells during chronic infection. Immunology 124: 277–293. 31

  17. A Theory for the Scalar Roughness and the Scalar Transfer Coefficients over Snow and Sea Ice,

    DTIC Science & Technology

    1986-09-01

    and camphor ... 7 4. Model predictions for an aerodynamically rough surface compared with the ex- perimental data of Dipprey and Sabersky (1963...stability 4.,. Ls Latent heat of sublimation of ice , . Pr v/D, Prandtl number Q Water vapor density Qr Water vapor density at an arbitrary reference height...specific heat of air at constant pressure L, = latent heat of sublimation of ice. Equations 1-3 define the roughness lengths. z0 is the familiar

  18. Dark-matter haloes and the M-σ relation for supermassive black holes

    NASA Astrophysics Data System (ADS)

    Larkin, Adam C.; McLaughlin, Dean E.

    2016-10-01

    We develop models of two-component spherical galaxies to establish scaling relations linking the properties of spheroids at z = 0 (total stellar masses, effective radii Re and velocity dispersions within Re) to the properties of their dark-matter haloes at both z = 0 and higher redshifts. Our main motivation is the widely accepted idea that the accretion-driven growth of supermassive black holes (SMBHs) in protogalaxies is limited by quasar-mode feedback and gas blow-out. The SMBH masses, MBH, should then be connected to the dark-matter potential wells at the redshift zqso of the blow-out. We specifically consider the example of a power-law dependence on the maximum circular speed in a protogalactic dark-matter halo: M_{BH}∝ V^4_{d,pk}, as could be expected if quasar-mode feedback were momentum-driven. For haloes with a given Vd,pk at a given zqso ≥ 0, our model scaling relations give a typical stellar velocity dispersion σap(Re) at z = 0. Thus, they transform a theoretical MBH-Vd,pk relation into a prediction for an observable MBH-σap(Re) relation. We find the latter to be distinctly non-linear in log-log space. Its shape depends on the generic redshift evolution of haloes in a Λ cold dark matter cosmology and the systematic variation of stellar-to-dark matter mass fraction at z = 0, in addition to any assumptions about the physics underlying the MBH-Vd,pk relation. Despite some clear limitations of the form we use for MBH versus Vd,pk, and even though we do not include any SMBH growth through dry mergers at low redshift, our results for MBH-σap(Re) compare well to data for local early types if we take zqso ˜ 2-4.

  19. Identification and characterization of a viroid resembling apple dimple fruit viroid in fig (Ficus carica L.) by next generation sequencing of small RNAs.

    PubMed

    Chiumenti, M; Torchetti, E M; Di Serio, F; Minafra, A

    2014-08-08

    Viroids are small (246-401 nt) circular and non coding RNAs infecting higher plants. They are targeted by host Dicer-like enzymes (DCLs) that generate small RNAs of 21-24 nt (sRNAs), which are involved in the host RNA silencing pathways. The accumulation in plant tissues of such viroid-derived small RNAs (vd-sRNAs) is a clear sign of an ongoing viroid infection. In this study, next generation sequencing of a sRNAs library and assembling of the sequenced vd-sRNAs were instrumental for the identification of a viroid resembling apple dimple fruit viroid (ADFVd) in a fig accession. After confirming by molecular methods the presence of this viroid in the fig tree, its population was characterized, showing that the ADFVd master sequence from fig diverges from that of the ADFVd reference variant from apple. Moreover, since this viroid accumulates at a low level in fig, a semi-nested RT-PCR assay was developed for detecting it in other fig accessions. ADFVd seems to have a wider host range than thought before and this poses questions about its epidemiology. A further characterization of ADFVd-sRNAs showed similar accumulation of (+) or (-) vd-sRNAs that mapped on the viroid genome generating hotspot profiles. Moreover, similarly to other nuclear-replicating viroids, vd-sRNAs of 21, 22 and 24 nt in size prevailed in the distribution profiles. Altogether, these data support the involvement of double-stranded RNAs and different DCLs, targeting the same restricted viroid regions, in the genesis of ADFVd-sRNAs.

  20. West Europe Report, No. 2154.

    DTIC Science & Technology

    2007-11-02

    for unrenewable fossil fuels with people who are worse off. [Answer] We in Sweden are not going to import more oil, of course, although it is true... Juan Manuel Fanjul Sedeno; ABC, 12 Apr 83) 105 - d - SWEDEN Palme: Conservatives Threaten Peace by Asking Freedom for East (Sven...Automobile Industry Association (VdA), in summing up, "conserve resources. They use less fuel and they no longer pollute the environment as severely as