121 research outputs found
Antimicrobial activity study of ethanolic extract of Alternanthera sessilis linn. aerial parts
The ethanolic extract of Alternanthera sessilis Linn. was evaluated for antimicrobial activity study against medically important gram-positive bacteria such as Staphylococcus aureus, Bacillus subtilis, Bacillus polymexia & Streotococcus faecalis, gram negative bacteria such as Pseudomonas aerugenosa, Salmonella typhii, Shigella dysenteriae & Escherichia coli and fungi like Penicillum notatum, Aspergillus niger & Candida albicans. The in-vitro antimicrobial activity, minimum inhibitory concentration (MIC) of ethanolic extract was performed by broth dilution method and the zone of inhibition was studied by agar disc diffusion method at concentrations of 2, 5 and 10mg/ml in DMSO. Ciprofloxacin (5µg/ml) and Cotrimazole (25µg/ml) were used as reference control for the antibacterial and antifungal studies respectively. The results of MIC study revealed the antimicrobial activity of the extract against the tested strains of microorganisms between concentration range of 50 and 400 µg/ml. The results of zone of inhibition study revealed concentration dependant nature of the extract with better effectiveness against gram-positive bacteria than gram-negative bacteria. The present study indicates the potential usefulness of Alternanthera sessilis Linn. aerial parts in the treatment of various pathogenic diseases as mentioned in the ayurvedic literature
THERAPEUTIC MANAGEMENT OF SARCOPTIC MANGE IN RABBIT WITH IVERMECTIN
Sarcoptic mange infected non-descriptive rabbits were successfully treated with
Ivermectin @ 400 µg / kg body weight sub-cutaneously once weekly for 4 weeks resulted
complete recovery within a month in Kalyani area, West Bengal, India
Improved infrared photoluminescence characteristics from circularly ordered self-assembled Ge islands
The formation of circularly ordered Ge-islands on Si(001) has been achieved because of nonuniform strain field around the periphery of the holes patterned by focused ion beam in combination with a self-assembled growth using molecular beam epitaxy. The photoluminescence (PL) spectra obtained from patterned areas (i.e., ordered islands) show a significant signal enhancement, which sustained till 200 K, without any vertical stacking of islands. The origin of two activation energies in temperature-dependent PL spectra of the ordered islands has been explained in detail
Inter-Landau-level Andreev Reflection at the Dirac Point in a Graphene Quantum Hall State Coupled to a NbSe2 Superconductor
Superconductivity and quantum Hall effect are distinct states of matter
occurring in apparently incompatible physical conditions. Recent theoretical
developments suggest that the coupling of quantum Hall effect with a
superconductor can provide a fertile ground for realizing exotic topological
excitations such as non-abelian Majorana fermions or Fibonacci particles. As a
step toward that goal, we report observation of Andreev reflection at the
junction of a quantum Hall edge state in a single layer graphene and a
quasi-two dimensional niobium diselenide (NbSe2) superconductor. Our principal
finding is the observation of an anomalous finite-temperature conductance peak
located precisely at the Dirac point, providing a definitive evidence for
inter-Landau level Andreev reflection in a quantum Hall system. Our
observations are well supported by detailed numerical simulations, which offer
additional insight into the role of the edge states in Andreev physics. This
study paves the way for investigating analogous Andreev reflection in a
fractional quantum Hall system coupled to a superconductor to realize exotic
quasiparticles.Comment: published verio
Evidence of a compensated semimetal with electronic correlations at the CNP of twisted double bilayer graphene
Recently, magic-angle twisted bilayer graphene (MATBLG) has shown the
emergence of various interaction-driven novel quantum phases at the
commensurate fillings of the moir'e superlattice, while the charge neutrality
point (CNP) remains mostly a vanilla insulator. Here, we show an emerging phase
of nearly compensated semimetallicity at the CNP of twisted double bilayer
graphene (TDBLG), a close cousin of MATBLG, with signatures of electronic
correlation. Using electrical and thermal transport, we find almost two orders
of magnitude enhancement of the thermopower in magnetic fields much smaller
than the extreme quantum limit, accompanied by a large magnetoresistance() at CNP. This provides indisputable experimental evidence that TDBLG
near CNP is a compensated semimetal. Moreover, at low temperatures, we observe
an unusual sublinear temperature dependence of resistance. A recent theory
predicts the formation of an excitonic metal near CNP, where small electron and
hole pockets coexist. We understand the sublinear temperature dependence in
terms of critical fluctuations in this theory
An Eight-year Study Report on Arsenic Contamination in Groundwater and Health Effects in Eruani Village, Bangladesh and an Approach for Its Mitigation
Based on several surveys during 1997-2005 and visits of a medical team
to Eruani village, Laksham upazila, Comilla district, Bangladesh, the
arsenic contamination situation and consequent clinical manifestations
of arsenicosis among the villagers, including dermatology, neuropathy,
and obstetric outcome, are reported here. Analysis of biological
samples from patients and non-patients showed high body burden of
arsenic. Even after eight years of known exposure, village children
were still drinking arsenic-contaminated water, and many of them had
arsenical skin lesions. There were social problems due to the symptoms
of arsenicosis. The last survey established that there is a lack of
proper awareness among villagers about different aspects of arsenic
toxicity. The viability of different options of safe water, such as
dugwells, deep tubewells, rainwater harvesting, and surface water with
watershed management in the village, was studied. Finally, based on 19
years of field experience, it was felt that, for any successful
mitigation programme, emphasis should be given to creating awareness
among villagers about the arsenic problem, role of arsenic-free water,
better nutrition from local fruits and vegetables, and, above all,
active participation of women along with others in the struggle against
the arsenic menace
Biocontrol of larval mosquitoes by Acilius sulcatus (Coleoptera: Dytiscidae)
<p>Abstract</p> <p>Background</p> <p>Problems associated with resistant mosquitoes and the effects on non-target species by chemicals, evoke a reason to find alternative methods to control mosquitoes, like the use of natural predators. In this regard, aquatic coleopterans have been explored less compared to other insect predators. In the present study, an evaluation of the role of the larvae of <it>Acilius sulcatus </it>Linnaeus 1758 (Coleoptera: Dytiscidae) as predator of mosquito immatures was made in the laboratory. Its efficacy under field condition was also determined to emphasize its potential as bio-control agent of mosquitoes.</p> <p>Methods</p> <p>In the laboratory, the predation potential of the larvae of <it>A. sulcatus </it>was assessed using the larvae of <it>Culex quinquefasciatus </it>Say 1823 (Diptera: Culicidae) as prey at varying predator and prey densities and available space. Under field conditions, the effectiveness of the larvae of <it>A. sulcatus </it>was evaluated through augmentative release in ten cemented tanks hosting immatures of different mosquito species at varying density. The dip density changes in the mosquito immatures were used as indicator for the effectiveness of <it>A. sulcatus </it>larvae.</p> <p>Results</p> <p>A single larva of <it>A. sulcatus </it>consumed on an average 34 IV instar larvae of <it>Cx. quinquefasciatus </it>in a 24 h period. It was observed that feeding rate of <it>A. sulcatus </it>did not differ between the light-on (6 a.m. – 6 p.m.), and dark (6 p.m. – 6 a.m.) phases, but decreased with the volume of water i.e., space availability. The prey consumption of the larvae of <it>A. sulcatus </it>differed significantly (P < 0.05) with different prey, predator and volume combinations, revealed through univariate ANOVA. The field study revealed a significant decrease (p < 0.05) in larval density of different species of mosquitoes after 30 days from the introduction of <it>A. sulcatus </it>larvae, while with the withdrawal, a significant increase (p < 0.05) in larval density was noted indicating the efficacy of <it>A. sulcatus </it>in regulating mosquito immatures. In the control tanks, mean larval density did not differ (p > 0.05) throughout the study period.</p> <p>Conclusion</p> <p>the larvae of the dytiscid beetle <it>A. sulcatus </it>proved to be an efficient predator of mosquito immatures and may be useful in biocontrol of medically important mosquitoes.</p
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