173 research outputs found

    Uji Efek Antipiretik Ekstrak Meniran (Phyllantus Niruri L.) Pada Tikus Wistar (Rattus Norvegicus) Jantan Yang Diinduksi Vaksin Dpt-hb

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    : The aim of this study is to investigate the antipyretic effect of leaf-flower extract (Phyllanthus niruri L.) in Wistar rats induced by DPT-HB vaccine. Samples were 15 Wistar rats as test animals and were divided into five groups of three in each. The negative control group was given orally distilled water, positive control group was given paracetamol and 3 experimental groups were given ethanolic leaf-flower extracts (100 mg, 200 mg and 300 mg /200 g body weight of rats). Pyrexia was induced in rats by intramuscular injection of 0.2 ml DPT-HB vaccine. Antipyretic activity was measured at 0, 30, 60, 90, 120, 150, 180 minutes after administration of leaf-flower extract, paracetamol and distilled water. The results showed that leaf-flower extract at a dose of 300 mg /200 g BW decreased the rectal temperature greater than with doses of 100 and 200 mg /200 g BW for 180 minutes of measurement. Conclusion: Leaf-flower extract has antipyretic effect in Wistar rats

    Uji Efek Ekstrak Etanol Daun Jambu Biji (Psidium Guajava L) Terhadap Kadar Kolesterol Total Tikus Wistar (Rattus Norvegicus)

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    : This research aims to determine the effect of ethanol extract of guava leaves on levels of total cholesterol of rat that is induced propylthiouracil. This was an experimental research. The sample used was 15 rats were divided into 5 groups (1 group is consist of 3 rats), namely: 1) positive control, 2) extract dose of 200 mg/kgBB, 3) extract dose of 400 mg/kgBB, 4) extract dose of 800 mg/kgBB and 5) negative control. Group 1 to 4 are given propylthiouracil given for 14 days, then given treatment appropiate with the group. The result show that: 1) the average of total cholesterol levels increased after administration propylthiouracil from 156.34 mg/dL to 247.84 mg/dL, 2) at a dose of 200 mg/kgBB, 400 mg/kgBB and 800 mg/kgBB showed a decline in total cholesterol levels by 32.73%, 58.73% and 47.26%, 3) the positive control decreased total cholesterol levels by 39.46% and 4) total cholesterol levels on negative is unstable (there are up and some are down). The result of this research concluse that: guava leaf extract at dose of 200 mg/kgBB, 400 mg/kgBB and 800 mg kgBB have an effect in lowering total cholesterol of rat had been induced prophylthiouracil

    Evidence for Quark-Hadron Duality in the Proton Spin Asymmetry A1A_1

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    Spin-dependent lepton-nucleon scattering data have been used to investigate the validity of the concept of quark-hadron duality for the spin asymmetry A1A_1. Longitudinally polarised positrons were scattered off a longitudinally polarised hydrogen target for values of Q2Q^2 between 1.2 and 12 GeV2^2 and values of W2W^2 between 1 and 4 GeV2^2. The average double-spin asymmetry in the nucleon resonance region is found to agree with that measured in deep-inelastic scattering at the same values of the Bjorken scaling variable xx. This finding implies that the description of A1A_1 in terms of quark degrees of freedom is valid also in the nucleon resonance region for values of Q2Q^2 above 1.6 GeV2^2.Comment: 5 pages, 1 eps figure, table added, new references added, in print in Phys. Rev. Let

    Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target

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    Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of both the pion (ϕ\phi) and the target spin axis (ϕS\phi_S) about the virtual photon direction and relative to the lepton scattering plane. The extracted Fourier component \cmpi is a signal of the previously unmeasured quark transversity distribution, in conjunction with the so-called Collins fragmentation function, also unknown. The Fourier component \smpi of the asymmetry arises from a correlation between the transverse polarization of the target nucleon and the intrinsic transverse momentum of quarks, as represented by the previously unmeasured Sivers distribution function. Evidence for both signals is observed, but the Sivers asymmetry may be affected by exclusive vector meson productio

    The Q2Q^2-dependence of the generalised Gerasimov-Drell-Hearn integral for the deuteron, proton and neutron

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    The Gerasimov-Drell-Hearn (GDH) sum rule connects the anomalous contribution to the magnetic moment of the target nucleus with an energy-weighted integral of the difference of the helicity-dependent photoabsorption cross sections. The data collected by HERMES with a deuterium target are presented together with a re-analysis of previous measurements on the proton. This provides a measurement of the generalised GDH integral covering simultaneously the nucleon-resonance and the deep inelastic scattering regions. The contribution of the nucleon-resonance region is seen to decrease rapidly with increasing Q2Q^2. The DIS contribution is sizeable over the full measured range, even down to the lowest measured Q2Q^2. As expected, at higher Q2Q^2 the data are found to be in agreement with previous measurements of the first moment of g1g_1. From data on the deuteron and proton, the GDH integral for the neutron has been derived and the proton--neutron difference evaluated. This difference is found to satisfy the fundamental Bjorken sum rule at Q2=5Q^2 = 5 GeV2^2.Comment: 12 pages, 10 figure

    First Measurement of the Tensor Structure Function b1b_1 of the Deuteron

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    The \Hermes experiment has investigated the tensor spin structure of the deuteron using the 27.6 GeV/c positron beam of \Hera. The use of a tensor polarized deuteron gas target with only a negligible residual vector polarization enabled the first measurement of the tensor asymmetry \At and the tensor structure function \bd for average values of the Bj{\o}rken variable 0.01<0.450.01<0.45 and of the squared four-momentum transfer 0.5GeV2<5GeV20.5 {\rm GeV^2} <5 {\rm GeV^2}. The quantities \At and \bd are found to be non-zero. The rise of \bd for decreasing values of xx can be interpreted to originate from the same mechanism that leads to nuclear shadowing in unpolarized scattering

    The Flavor Asymmetry of the Light Quark Sea from Semi-inclusive Deep-inelastic Scattering

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    The flavor asymmetry of the light quark sea of the nucleon is determined in the kinematic range 0.02<x<0.3 and 1 GeV^2<Q^2<10 GeV^2, for the first time from semi-inclusive deep-inelastic scattering. The quantity (dbar(x)-ubar(x))/(u(x)-d(x)) is derived from a relationship between the yields of positive and negative pions from unpolarized hydrogen and deuterium targets. The flavor asymmetry dbar-ubar is found to be non-zero and x dependent, showing an excess of dbar over ubar quarks in the proton.Comment: 7 Pages, 2 figures, RevTeX format; slight revision in text, small change in extraction of dbar-ubar and comparison with a high q2 parameterizatio
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