1,272 research outputs found

    Experimental and Clinical Evaluation of Nootropic Activity of Bacopa monniera Linn. (Brahmi)

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    Bacopa monniera Linn. (Brahmi) is an annual creeper belonging to familyScrophulariaceae and growing all over the Indian sub-continent in marshy areas. It is a major Medhya Rasayana used in Ayurveda for treatment of memory disorders. Large number of saponins and glycosides has been isolated from the plant. Most of the experimental and clinical studies have been done with crude extracts or standardized preparation of the two active saponins Bacosides A and B.Extracts or saponin mixture facilitate learning, improve consolidation of learned behavior and delay extinction in several models of learnt behavior in normal rats and mice as well as in chemically induced or transgenic models of Alzheimer's disease. They also prevent or reverse amnesia produced by drugs, stress or ischemic hypoxia. Other CNS effects include anti-anxiety, anti-convulsant and analgesic activity. Several mechanisms have been proposed to explain the mechanism of these CNS effects.Extracts as well as the bacoside preparation have been found safe and well tolerated in healthy volunteers in single dose or chronic administration for several weeks in a number of double blind placebo controlled studies in India and abroad. Chronic administration significantly improved information processing, learning and memory consolidation. It was found more effective than caffeine in a comparative study.Double blind placebo controlled studies with bacoside preparation have demonstrated beneficial effects and safety in elderly patients with Age Related Memory Impairment and in children with Attention Deficit Memory Disorder. It has also been found useful in anxiety neurosis, epilepsy and sleep disturbances in post menopausal women.The standardized preparation is marketed as a prescription drug after having obtained the necessary regulatory approval in India, Australia, New Zealand and South Africa and as an OTC product in several other south east Asian and African countries.Bacopa monniera Linn. (Brahmi) is an annual creeper belonging to familyScrophulariaceae and growing all over the Indian sub-continent in marshy areas. It is amajor Medhya Rasayana used in Ayurveda for treatment of memory disorders. Largenumber of saponins and glycosides has been isolated from the plant. Most of theexperimental and clinical studies have been done with crude extracts or standardizedpreparation of the two active saponins Bacosides A and B.Extracts or saponin mixture facilitate learning, improve consolidation of learnedbehavior and delay extinction in several models of learnt behavior in normal rats andmice as well as in chemically induced or transgenic models of Alzheimer's disease.They also prevent or reverse amnesia produced by drugs, stress or ischemic hypoxia.Other CNS effects include anti-anxiety, anti-convulsant and analgesic activity. Severalmechanisms have been proposed to explain the mechanism of these CNS effects.Extracts as well as the bacoside preparation have been found safe and well tolerated inhealthy volunteers in single dose or chronic administration for several weeks in anumber of double blind placebo controlled studies in India and abroad. Chronicadministration significantly improved information processing, learning and memoryconsolidation. It was found more effective than caffeine in a comparative study.Double blind placebo controlled studies with bacoside preparation have demonstratedbeneficial effects and safety in elderly patients with Age Related Memory Impairmentand in children with Attention Deficit Memory Disorder. It has also been found usefulin anxiety neurosis, epilepsy and sleep disturbances in post menopausal women.The standardized preparation is marketed as a prescription drug after having obtainedthe necessary regulatory approval in India, Australia, New Zealand and South Africaand as an OTC product in several other south east Asian and African countries.Bacopa monniera Linn. (Brahmi) is an annual creeper belonging to familyScrophulariaceae and growing all over the Indian sub-continent in marshy areas. It is a major Medhya Rasayana used in Ayurveda for treatment of memory disorders. Large number of saponins and glycosides has been isolated from the plant. Most of the experimental and clinical studies have been done with crude extracts or standardized preparation of the two active saponins Bacosides A and B.Extracts or saponin mixture facilitate learning, improve consolidation of learned behavior and delay extinction in several models of learnt behavior in normal rats and mice as well as in chemically induced or transgenic models of Alzheimer's disease. They also prevent or reverse amnesia produced by drugs, stress or ischemic hypoxia. Other CNS effects include anti-anxiety, anti-convulsant and analgesic activity. Several mechanisms have been proposed to explain the mechanism of these CNS effects.Extracts as well as the bacoside preparation have been found safe and well tolerated in healthy volunteers in single dose or chronic administration for several weeks in a number of double blind placebo controlled studies in India and abroad. Chronic administration significantly improved information processing, learning and memory consolidation. It was found more effective than caffeine in a comparative study.Double blind placebo controlled studies with bacoside preparation have demonstrated beneficial effects and safety in elderly patients with Age Related Memory Impairment and in children with Attention Deficit Memory Disorder. It has also been found useful in anxiety neurosis, epilepsy and sleep disturbances in post menopausal women.The standardized preparation is marketed as a prescription drug after having obtained the necessary regulatory approval in India, Australia, New Zealand and South Africa and as an OTC product in several other south east Asian and African countries.Bacopa monniera Linn. (Brahmi) is an annual creeper belonging to familyScrophulariaceae and growing all over the Indian sub-continent in marshy areas. It is amajor Medhya Rasayana used in Ayurveda for treatment of memory disorders. Largenumber of saponins and glycosides has been isolated from the plant. Most of theexperimental and clinical studies have been done with crude extracts or standardizedpreparation of the two active saponins Bacosides A and B.Extracts or saponin mixture facilitate learning, improve consolidation of learnedbehavior and delay extinction in several models of learnt behavior in normal rats andmice as well as in chemically induced or transgenic models of Alzheimer's disease.They also prevent or reverse amnesia produced by drugs, stress or ischemic hypoxia.Other CNS effects include anti-anxiety, anti-convulsant and analgesic activity. Severalmechanisms have been proposed to explain the mechanism of these CNS effects.Extracts as well as the bacoside preparation have been found safe and well tolerated inhealthy volunteers in single dose or chronic administration for several weeks in anumber of double blind placebo controlled studies in India and abroad. Chronicadministration significantly improved information processing, learning and memoryconsolidation. It was found more effective than caffeine in a comparative study.Double blind placebo controlled studies with bacoside preparation have demonstratedbeneficial effects and safety in elderly patients with Age Related Memory Impairmentand in children with Attention Deficit Memory Disorder. It has also been found usefulin anxiety neurosis, epilepsy and sleep disturbances in post menopausal women.The standardized preparation is marketed as a prescription drug after having obtainedthe necessary regulatory approval in India, Australia, New Zealand and South Africaand as an OTC product in several other south east Asian and African countries

    Antireflective Huygens’ Metasurface with Correlated Disorder Made from High-Index Disks Implemented into Silicon Heterojunction Solar Cells

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    A large variety of different strategies has been proposed as alternatives to random textures to improve light coupling into solar cells. While the understanding of dedicated nanophotonic systems deepens continuously, only a few of the proposed designs are industrially accepted due to a lack of scalability. In this Article, a tailored disordered arrangement of high-index dielectric submicron-sized titanium dioxide (TiO2_{2}) disks is experimentally exploited as an antireflective Huygens’ metasurface for standard heterojunction silicon solar cells. The disordered array is fabricated using a scalable bottom-up technique based on colloidal self-assembly that is applicable virtually irrespective of material or surface morphology of the device. We observe a broadband reduction of reflectance resulting in a relative improvement of a short-circuit current by 5.1% compared to a reference cell with an optimized flat antireflective indium tin oxide (ITO) layer. A theoretical model based on Born’s first approximation is proposed that links the current increase in the arrangement of disks expressed in terms of the structure factor S(q) of the disk array. Additionally, we discuss the optical performance of the metasurface within the framework of helicity preservation, which can be achieved at specific wavelengths for an isolated disk for illumination along the symmetry axis by tuning its dimensions. By comparison to a simulated periodic metasurface, we show that this framework is applicable in the case of the structure factor approaching zero and the disks’ arrangement becoming stealthy hyperuniform

    Microwave shielding properties of Co/Ni attached to single walled carbon nanotubes

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    Cobalt/nickel nanoparticles attached to single-walled carbon nanotubes (Co/Ni@SWCNTs) were prepared by dc-arc discharge technique. Co/Ni@SWCNTs were characterized by scanning electron microscopy, high resolution transmission electron microscopy (HRTEM), Raman spectroscopy and energy dispersive X-ray analysis techniques. HRTEM results confirmed attachment of magnetic nanoparticles onto SWCNTs having 1.2 nm diameter. A microwave shielding effectiveness value of 24 dB (blocking >99% radiation) by a 1.5 mm thick sample in the frequency range of 12.4-18 GHz was observed. In order to understand the mechanism of shielding, dielectric andmagnetic attributes of the shielding effectiveness of Co/Ni@SWCNTs have been evaluated. Eddy currents and natural resonances due to the presence of magnetic nanoparticles, electronic polarization and their relaxation, interfacial polarization and unique composition of the shield contributed significantly in achieving good shielding effectiveness. The observed microwave shielding crossed the limit required for commercial applications which suggests that these nanocomposites are promising microwave shielding materials in the Ku band

    Early Observations of the Type Ia Supernova iPTF 16abc: A Case of Interaction with Nearby, Unbound Material and/or Strong Ejecta Mixing

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    Early observations of Type Ia supernovae (SNe Ia) provide a unique probe of their progenitor systems and explosion physics. Here we report the intermediate Palomar Transient Factory (iPTF) discovery of an extraordinarily young SN Ia, iPTF 16abc. By fitting a power law to our early light curve, we infer that first light for the SN, that is when the SN could have first been detected by our survey, occurred only 0.15±0.070.150.15\pm_{0.07}^{0.15} days before our first detection. In the \sim24 hr after discovery, iPTF 16abc rose by \sim2 mag, featuring a near-linear rise in flux for \gtrsim3 days. Early spectra show strong C II absorption, which disappears after \sim7 days. Unlike the extensivelyobserved SN Ia SN 2011fe, the (BV)0(B-V)_0 colors of iPTF 16abc are blue and nearly constant in the days after explosion. We show that our early observations of iPTF 16abc cannot be explained by either SN shock breakout and the associated, subsequent cooling or the SN ejecta colliding with a stellar companion. Instead, we argue that the early characteristics of iPTF 16abc, including (i) the rapid, near-linear rise, (ii) the nonevolving blue colors, and (iii) the strong C II absorption, are the result of either ejecta interaction with nearby, unbound material or vigorous mixing of radioactive 56^{56}Ni in the SN ejecta, or a combination of the two. In the next few years, dozens of very young \textit{normal} SNe Ia will be discovered, and observations similar to those presented here will constrain the white dwarf explosion mechanism.Comment: 18 pages, 12 figures, accepted by Ap

    A new measurement of K+(e4) decay and the s-wave pi-pi-scattering length a00

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    A sample of 400000 events from the decay K+->pi+pi-e+nu(e)(K(e4)) has been collected in experiment E865 at the Brookhaven AGS. The analysis of these data yields new measurements of the K(e4) branching ratio (4.11+-0.01+-0.11)*10**(-5)), the s-wave pi-pi scattering length a00=0.228+-0.012+-0.003, and the form factors F, G, and H of the hadronic current and their dependence on the invariant pi-pi mass

    First observation of the decay K+ -> e+ nu mu+ mu-

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    Experiment 865 at the Brookhaven AGS has observed the decay K^+ -> e^+ nu mu^+ mu^-. The branching ratio extracted is (1.72 +/- 0.37(stat) +/- 0.17(syst) +/- 0.19(model)) x 10^{-8} where the third term in the error results from the use of a model to extrapolate into a kinematic region dominated by background.Comment: 4 pages, 6 figures, Revtex4. Correction to figure and minor text change

    An Improved upper limit on the decay K^+ -> pi^+ mu^+ e^-

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    Based on results of a search for the lepton-family-number-violating decay K+π+μ+eK^+ \to \pi^+\mu^+ e^- with data collected by experiment E865 at the Alternating Gradient Synchrotron of Brookhaven National Laboratory, we place an upper limit on the branching ratio at 2.1×10112.1 \times 10^{-11} (90% C.L.). Combining the results with earlier E865 data and those of a previous experiment, E777, an upper limit on the branching ratio of 1.3×10111.3 \times 10^{-11} (90% C.L.) is obtained.Comment: v2: 13 pages, submitted to the Phys. Rev. D v3: 13 pages, resubmitted to Phys. Rev. D (corrections include: a more detailed overview of the combined analysis of the available experimntal data

    New, high statistics measurement of the K+ -> pi0 e+ nu (Ke3) branching ratio

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    E865 at the Brookhaven National Laboratory AGS collected about 70,000 K+(e3) events with the purpose of measuring the relative K+(e3) branching ratio. The pi0 in all the decays was detected using the e+e- pair from pi0 -> e+e-gamma decay and no photons were required. Using the Particle Data Group branching ratios for the normalization decays we obtain BR(K+(e3(gamma))=(5.13+/-0.02(stat)+/-0.09(sys)+/-0.04(norm))%, where K+(e3(gamma))includestheeffectofvirtualandrealphotons.Thisresultis2.3sigmahigherthanthecurrentParticleDataGroupvalue.TheimplicationsofthisresultfortheK+(e3(gamma)) includes the effect of virtual and real photons. This result is 2.3 sigma higher than the current Particle Data Group value. The implications of this result for the V_{us}$ element of the CKM matrix, and the matrix's unitarity are discussed.Comment: 4 pages, 5 figures; final version accepted by PR
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