1,272 research outputs found
Experimental and Clinical Evaluation of Nootropic Activity of Bacopa monniera Linn. (Brahmi)
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
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 (TiO) 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
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
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 days before our first
detection. In the 24 hr after discovery, iPTF 16abc rose by 2 mag,
featuring a near-linear rise in flux for 3 days. Early spectra show
strong C II absorption, which disappears after 7 days. Unlike the
extensivelyobserved SN Ia SN 2011fe, the 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
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
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-
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^-
Based on results of a search for the lepton-family-number-violating decay
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 (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 (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
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
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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