1,372 research outputs found

    Structural insights into the production of 3-hydroxypropionic acid by aldehyde dehydrogenase from Azospirillum brasilense

    Get PDF
    3-Hydroxypropionic acid (3-HP) is an important platform chemical to be converted to acrylic acid and acrylamide. Aldehyde dehydrogenase (ALDH), an enzyme that catalyzes the reaction of 3-hydroxypropionaldehyde (3-HPA) to 3-HP, determines 3-HP production rate during the conversion of glycerol to 3-HP. To elucidate molecular mechanism of 3-HP production, we determined the first crystal structure of a 3-HP producing ALDH, alpha-ketoglutarate-semialdehyde dehydrogenase from Azospirillum basilensis (AbKGSADH), in its apo-form and in complex with NAD(+). Although showing an overall structure similar to other ALDHs, the AbKGSADH enzyme had an optimal substrate binding site for accepting 3-HPA as a substrate. Molecular docking simulation of 3-HPA into the AbKGSADH structure revealed that the residues Asn159, Gln160 and Arg163 stabilize the aldehyde-and the hydroxyl-groups of 3-HPA through hydrogen bonds, and several hydrophobic residues, such as Phe156, Val286, Ile288, and Phe450, provide the optimal size and shape for 3-HPA binding. We also compared AbKGSADH with other reported 3-HP producing ALDHs for the crucial amino acid residues for enzyme catalysis and substrate binding, which provides structural implications on how these enzymes utilize 3-HPA as a substrate

    Drug Quality Control in Kenya: Observation in Drug Analysis and Research Unit during the Period 1996-2000

    Get PDF
    The Drug Analysis and Research Unit received and analyzed 261 drug samples over a five-year period, 1996 to 2000. Samples were received from regulatory authorities, local industry, non-governmental organizations, hospitals and private practitioners. The samples analyzed constituted 59.8 % locally manufactured and 40.2 % imported products. The overall rate of failure to comply with quality specifications set out in the respective monographs was 21.1 %. This represents 24.6 % and 16.2 % of the locally manufactured and imported drugs, respectively. Key Words: Quality control, active pharmaceutical ingredient content, dissolution. East and Central African Journal of Pharmaceutical Sciences Vol.5(2) 2002: 28-3

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

    Get PDF
    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

    Get PDF
    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

    Get PDF
    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Quality of Antiretroviral Drugs Analyzed in the Drug Analysis and Research Unit During 2000-2003

    Get PDF
    During the period 2000-2003 the Drug Analysis and Research Unit received and analyzed 33 samples of antiretroviral drugs. Locally manufactured products accounted for 57.6 % of the samples, while the imported drugs constituted 42.4 %. The drugs consisted of single, double and triple component preparations. They were subjected to the identity, assay and dissolution tests. 30 samples (90.9 %) complied with compedial specifications for these tests, while 3 failed. The results obtained show that manufacture of quality generic antiretroviral drugs is achievable. Key Words: Antiretroviral, assay, dissolution, nucleoside reverse-transcriptase inhibitor East & Central African Journal of Pharmaceutical Sciences Vol.6(1) 2003: 20-2

    Drug Quality Control in Kenya: Observation in the Drug Analysis and Research Unit During the Period 2001-2005

    Get PDF
    During the five-year period January 2001 to December 2005, the Drug Analysis and Research Unit received and analyzed 394 drug samples. Samples were received from regulatory authorities, local industry, non-governmental organizations, hospitals and private practitioners. The samples analyzed constituted 37.8 % locally manufactured and 62.2 % imported products. In contrast to previous years when failure rates of over 20 % were recorded, the overall rate of failure to comply with compendial quality specifications was 6.1 %, comprising of 8.7 % locally manufactured and 4.5 % imported drugs

    Monitoring Functional Capability of Individuals with Lower Limb Amputations Using Mobile Phones

    Get PDF
    To be effective, a prescribed prosthetic device must match the functional requirements and capabilities of each patient. These capabilities are usually assessed by a clinician and reported by the Medicare K-level designation of mobility. However, it is not clear how the K-level designation objectively relates to the use of prostheses outside of a clinical environment. Here, we quantify participant activity using mobile phones and relate activity measured during real world activity to the assigned K-levels. We observe a correlation between K-level and the proportion of moderate to high activity over the course of a week. This relationship suggests that accelerometry-based technologies such as mobile phones can be used to evaluate real world activity for mobility assessment. Quantifying everyday activity promises to improve assessment of real world prosthesis use, leading to a better matching of prostheses to individuals and enabling better evaluations of future prosthetic devices.Max Nader Center for Rehabilitation Technologies and Outcome

    The deuteron: structure and form factors

    Get PDF
    A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic
    corecore