Antibacterial activity of Glycyrrhiza glabra roots against certain gram-positive and gram-negative bacterial strains

The present study aimed to evaluate the antibacterial potency of grinded crude material (root of Glycyrrhiza glabra) against some gram-positive and gram-negative bacterial strains. Two solvents (methanol and acetone) were used to extract the phytochemicals from the test material. Four different concentrations (100%, 75%, 50% and 25%) of methanolic and acetonic extract were used to investigate the inhibiting properties against Salmonella typhi, Escherichia.coli, Vibrio cholerae, Staphylococcus aureus, Bacillus cereus and Bacillus subtilis strains. Among methanol and acetone extracts, later exhibited low antibacterial activity. The 100% (w/v) concentration of both extracts showed maximum inhibition against B. subtilis followed by E. coli, S. aureus, B. cereus, S. typhi and V. Cholerae. Maximum activity in acetonic extract was obtained against B. cereus followed by S. typhi, E. coli, V. cholerae and S .aureus and minimum in B. subtilis. A reverse pattern of inhibition activity was found in both extacts (methanolic and acetonic) against B. subtilis. Maximum activity was found in methanolic extract against B. subtilis (18.6 mm) but it was only 14.3 mm against this strain in acetonic extract. The antibacterial activity of the crude samples corresponded to that of concentration. Hence there was positive correlation of antibacterial activity with the test material

Treatment of Snake Bites at a Regional Burn Center: Report of a Case Series

Background. Although uncommon, snakebites can cause significant morbidity and mortality. The objective of this study was to review the characteristics, treatment, and outcome of patients with a suspected or known snakebite who were treated at a regional verified burn center. Methods. A retrospective chart review of all snakebite victims was conducted for the time frame between January 1991 and June 2009. Results. During the study period, 12 patients were identified. One of the twelve patients was excluded because he had been admitted as an outpatient for wound debridement after being initially treated at another facility. Ten of the remaining 11 patients were male (90.9%). Rattlesnakes were responsible for the majority of bites. One of the eleven patients needed a fasciotomy. The majority of patients received antivenin (ACP/fabAV). No anaphylactoid reactions to either antivenin were recorded. There were no deaths. Conclusion. With burn centers evolving into centers for the care of complex wounds, patients with snakebite injuries can be managed safely in a burn center

Cytotoxic Effect of Poly-Dispersed Single Walled Carbon Nanotubes on Erythrocytes In Vitro and In Vivo

Single wall Carbon Nanotubes (SWCNTs) are hydrophobic and do not disperse in aqueous solvents. Acid functionalization of SWCNTs results in attachment of carboxy and sulfonate groups to carbon atoms and the resulting acid functionalized product (AF-SWCNTs) is negatively charged and disperses easily in water and buffers. In the present study, effect of AF-SWCNTs on blood erythrocytes was examined. Incubation of mouse erythrocytes with AF-SWCNTs and not with control SWCNTs, resulted in a dose and time dependent lysis of erythrocyte. Using fluorescence tagged AF-SWCNTs, binding of AF-SWCNTs with erythrocytes could be demonstrated. Confocal microscopy results indicated that AF-SWCNTs could enter the erythrocytes. Treatment with AF-SWCNTs resulted in exposure of hydrophobic patches on erythrocyte membrane that is indicative of membrane damage. A time and dose dependent increase in externalization of phosphatidylserine on erythrocyte membrane bilayer was also found. Administration of AF-SWCNTs through intravenous route resulted in a transient anemia as seen by a sharp decline in blood erythrocyte count accompanied with a significant drop in blood haemoglobin level. Administration of AF-SWCNTs through intratracheal administration also showed significant decline in RBC count while administration through other routes (gavage and intra-peritoneal) was not effective. By using a recently developed technique of a two step in vivo biotinylation of erythrocytes that enables simultaneous enumeration of young (age <10 days) and old (age>40 days) erythrocytes in mouse blood, it was found that the in vivo toxic effect of AF-SWCNTs was more pronounced on older subpopulation of erythrocytes. Subpopulation of old erythrocytes fell after treatment with AF-SWCNTs but recovered by third day after the intravenous administration of AF-SWCNTs. Taken together our results indicate that treatment with AF-SWCNTs results in acute membrane damage and eventual lysis of erythrocytes. Intravenous administration of AF-SWCNTs resulted in a transient anemia in which older erythrocytes are preferably lysed

Massive Spin Collective Mode in Quantum Hall Ferromagnet

It is shown that the collective spin rotation of a single Skyrmion in quantum Hall ferromagnet can be regarded as precession of the entire spin texture in the external magnetic field, with an effective moment of inertia which becomes infinite in the zero g-factor limit. This low-lying spin excitation may dramatically enhance the nuclear spin relaxation rate via the hyperfine interaction in the quantum well slightly away from filling factor equal one.Comment: 4 page

Optically Pumped NMR Measurements of the Electron Spin Polarization in GaAs Quantum Wells near Landau Level Filling Factor nu=1/3

The Knight shift of Ga-71 nuclei is measured in two different electron-doped multiple quantum well samples using optically pumped NMR. These data are the first direct measurements of the electron spin polarization, P(nu,T)=/max, near nu=1/3. The P(T) data at nu=1/3 probe the neutral spin-flip excitations of a fractional quantum Hall ferromagnet. In addition, the saturated P(nu) drops on either side of nu=1/3, even in a Btot=12 Tesla field. The observed depolarization is quite small, consistent with an average of about 0.1 spin-flips per quasihole (or quasiparticle), a value which does not appear to be explicable by the current theoretical understanding of the FQHE near nu=1/3.Comment: 4 pages (REVTEX), 5 eps figures embedded in text; minor changes, published versio

Spectroscopic Evidence for the Localization of Skyrmions near Nu=1 as T->0

Optically pumped nuclear magnetic resonance measurements of Ga-71 spectra were carried out in an n-doped GaAs/Al0.1Ga0.9As multiple quantum well sample near the integer quantum Hall ground state Nu=1. As the temperature is lowered (down to T~0.3 K), a ``tilted plateau'' emerges in the Knight shift data, which is a novel experimental signature of quasiparticle localization. The dependence of the spectra on both T and Nu suggests that the localization is a collective process. The frozen limit spectra appear to rule out a 2D lattice of conventional skyrmions.Comment: 4 pages (REVTEX), 5 eps figures embedded in text, published versio

BWIBots: A platform for bridging the gap between AI and human–robot interaction research

Recent progress in both AI and robotics have enabled the development of general purpose robot platforms that are capable of executing a wide variety of complex, temporally extended service tasks in open environments. This article introduces a novel, custom-designed multi-robot platform for research on AI, robotics, and especially human–robot interaction for service robots. Called BWIBots, the robots were designed as a part of the Building-Wide Intelligence (BWI) project at the University of Texas at Austin. The article begins with a description of, and justification for, the hardware and software design decisions underlying the BWIBots, with the aim of informing the design of such platforms in the future. It then proceeds to present an overview of various research contributions that have enabled the BWIBots to better (a) execute action sequences to complete user requests, (b) efficiently ask questions to resolve user requests, (c) understand human commands given in natural language, and (d) understand human intention from afar. The article concludes with a look forward towards future research opportunities and applications enabled by the BWIBot platform

A Composite Fermion Hofstader Problem: Partially Polarized Density Wave States in the 2/5 FQHE

It is well-known that the 2/5 state is unpolarized at zero Zeeman energy, while it is fully polarized at large Zeeman energies. A novel state with charge/spin density wave order for Composite Fermions is proposed to exist at intermediate values of the Zeeman coupling for 2/5. This state has half the maximum possible polarization, and can be extended to other incompressible fractions. A Hartree-Fock calculation based on the new approach for all fractional quantum Hall states developed by R.Shankar and the author is used to demonstrate the stability of this state to single-particle excitations, and compute gaps. We compare our results with a very recent experiment which shows direct evidence for the existence of such a state, and also with more indirect evidence from past experiments.Comment: One reference added, minor clarifying change