305 research outputs found

    Enhancement of field generation via maximal atomic coherence prepared by fast adiabatic passage in Rb vapor

    Get PDF
    We have experimentally demonstrated the enhancement of coherent Raman scattering in Rb atomic vapor by exciting atomic coherence with fractional stimulated Raman adiabatic passage. Experimental results are in good agreement with numerical simulations. The results support the possibility of increasing the sensitivity of CARS by preparing atomic or molecular coherence using short pulses

    Electromagnetically induced transparency in cold 85Rb atoms trapped in the ground hyperfine F = 2 state

    Full text link
    We report electromagnetically induced transparency (EIT) in cold 85Rb atoms, trapped in the lower hyperfine level F = 2, of the ground state 52S1/2^{2}S_{1/2} (Tiwari V B \textit{et al} 2008 {\it Phys. Rev.} A {\bf 78} 063421). Two steady state Λ\Lambda-type systems of hyperfine energy levels are investigated using probe transitions into the levels F^{\prime} = 2 and F^{\prime} = 3 of the excited state 52P3/2^{2}P_{3/2} in the presence of coupling transitions F = 3 \to F^{\prime} = 2 and F = 3 \to F^{\prime} = 3, respectively. The effects of uncoupled magnetic sublevel transitions and coupling field's Rabi frequency on the EIT signal from these systems are studied using a simple theoretical model.Comment: 12 pages, 7 figure

    EVALUATION OF DIFFERENT REARING MEDIA FOR CORCYRA CEPHALONICA (STAINTON) UNDER LABORATORY CONDITION

    Get PDF
    The rearing media to improve the mass production of C. cephalonica as a factitious host revealed three promising media viz., T3 (sorghum + groundnut + powdered yeast), T4 (sorghum + gram + powdered yeast) and T6 (sorghum + cowpea + powdered yeast) with heavier larvae in T3 (53.33 mg), T4 (52.50 mg) and T6 (54.50 mg). The heavier pupae were also recorded in T4 (34.67 mg), T6 (34.17 mg) and T3 (33.17 mg) while heavier female moths were recorded in T3 (39.33 mg), T4 (34.83 mg) and T6 (34.0 mg). The maximum moth emergence were in T3 (523.84), T4 (476.34) and T6 (470.0). Whereas, the maximum total females were noticed in T3 (266.17), T6 (251.50) and T4 (243.34). The maximum fecundity was recorded in Corcyra females emerged from T3 (611.54), T4 (494.28) and T6 (481.08). Moreover, the maximum projected egg laying was realized from the females emerged from T3 (8.14 cc), T6 (6.10 cc) and T4 (6.01 cc). The significantly maximum weight of 100 Corcyra egg was exhibited with females emerged from T4 (3.73 mg), T6 (3.70 mg). The maximum length and breadth of egg was obtained from females emerged from T4 (0.70 and 0.40 mm), T6 (0.62 and 0.39 mm) and T3 (0.56 and 0.35 mm), respectively. However, no much detrimental impact on the life cycle of C. cephalonica were exhibited through modification of rearing media though the female preponderance (sex ratio as M: F) was noticed in T3 (0.97:1), T4 (0.96:1) and T6 (0.87:1)

    Dynamics of coherently pumped lasers with linearly polarized pump and generated fields

    Get PDF
    The influence of light polarization on the dynamics of an optically pumped single-mode laser with a homogeneously broadened four-level medium is theoretically investigated in detail. Pump and laser fields with either parallel or crossed linear polarizations are considered, as are typical in far-infrared-laser experiments. Numerical simulations reveal dramatically different dynamic behaviors for these two polarization configurations. The analysis of the model equations allows us to find the physical origin of both behaviors. In particular, the crossed-polarization configuration is shown to be effective in decoupling the pump and laser fields, thus allowing for the appearance of Lorenz-type dynamics

    Comparison of capillary based microflurometric assay for CD4+ T cell count estimation with dual platform Flow cytometry

    Get PDF
    The CD4+ T cell count estimation is an important monitoring tool for HIV disease progression and efficacy of anti-retroviral treatment (ART). Due to availability of ART at low cost in developing countries, quest for reliable cost effective alternative methods for CD4+ T cell count estimation has gained importance. A simple capillary-based microflurometric assay (EasyCD4 System, Guava Technology) was compared with the conventional flow cytometric assay for estimation of CD4+ T cell counts in 79 HIV infected individuals. CD4+ T cell count estimation by both the assays showed strong correlation (r = 0.938, p < 0.001, 95% CI 0.90 to 0.96). The Bland Altman plot analysis showed that the limits of variation were within agreeable limits of ± 2SD (-161 to 129 cells/mm(3)). The Easy CD4 assay showed 100% sensitivity for estimating the CD4+ T cell counts < 200 cells/mm(3 )and < 350 cells/mm(3 )and 97% sensitivity to estimate CD4+ T cell count < 500 cells/mm(3). The specificity ranged from 82 to 100%. The Kappa factor ranged from 0.735 for the CD4+ T cell counts < 350 cells/mm(3 )to 0.771 for < 500 cells/mm(3 )CD4+ T cell counts. The system works with a simple protocol, is easy to maintain and has low running cost. The system is compact and generates minimum amount of waste. Hence the EasyCD4 System could be applied for estimation of CD4+ T cell counts in resource poor settings

    Few cycle dynamics of multiphoton double ionization

    Get PDF
    In intense field ionization, an electron removed from the atomic core oscillates in the combined fields of the laser and the parent ion. This oscillation forces repeated revivals of its spatial correlation with the bound electrons. The total probability of double ionization depends on the number of returns and therefore on the number of optical periods in the laser pulse. We observed the yield of Ne\ub2\u207a relative to Ne\u207a with 12 fs pulses to be clearly less compared to 50 fs pulses in qualitative agreement with our theoretical model.Peer reviewed: YesNRC publication: Ye

    Ringer's lactate improves liver recovery in a murine model of acetaminophen toxicity

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Acetaminophen (APAP) overdose induces massive hepatocyte necrosis. Liver regeneration is a vital process for survival after a toxic insult. Since hepatocytes are mostly in a quiescent state (G<sub>0</sub>), the regeneration process requires the priming of hepatocytes by cytokines such as TNF-α and IL-6. Ringer's lactate solution (RLS) has been shown to increase serum TNF-α and IL-6 in patients and experimental animals; in addition, RLS also provides lactate, which can be used as an alternative metabolic fuel to meet the higher energy demand by liver regeneration. Therefore, we tested whether RLS therapy improves liver recovery after APAP overdose.</p> <p>Methods</p> <p>C57BL/6 male mice were intraperitoneally injected with a single dose of APAP (300 mg/kg dissolved in 1 mL sterile saline). Following 2 hrs of APAP challenge, the mice were given 1 mL RLS or Saline treatment every 12 hours for a total of 72 hours.</p> <p>Results</p> <p>72 hrs after APAP challenge, compared to saline-treated group, RLS treatment significantly lowered serum transaminases (ALT/AST) and improved liver recovery seen in histopathology. This beneficial effect was associated with increased hepatic tissue TNF-α concentration, enhanced hepatic NF-κB DNA binding and increased expression of cell cycle protein cyclin D1, three important factors in liver regeneration.</p> <p>Conclusion</p> <p>RLS improves liver recovery from APAP hepatotoxicity.</p
    corecore