8,153 research outputs found
Electromagnetic transition rates of ÂčÂČC and Âčâ¶O in rotational-vibrational models
We develop a formalism to calculate electromagnetic (EM) transition rates for rotational-vibrational models of nuclei. The formalism is applied to recently proposed models of ÂčÂČC and Âčâ¶O which are inspired by nuclear dynamics in the Skyrme model. We compare the results to experimental data as well as other nuclear models. The results for ÂčÂČC are in good agreement with the data across all models, making it difficult to differentiate the models. More experimental data is needed to do this, and we suggest which transitions would be most interesting to measure. The models of Âčâ¶O are less successful in describing the data, and we suggest some possible improvements to our approximations which may help
Quantized Skyrmions from SU(4) weight diagrams
Starting from solutions of the lightly-bound Skyrme model, we construct many
new Skyrmion solutions of the standard Skyrme model with tetrahedral or
octahedral symmetry. These solutions are closely related to weight diagrams of
the group SU(4), which enables us to systematically derive some geometric and
energetic properties of the Skyrmions, up to baryon number 85. We discuss the
rigid body quantization of these Skyrmions, and compare the results with
properties of a selection of observed nuclei
Formulation and Development of Dendrimer-Based Transdermal Patches of Meloxicam for the Management of Arthritis
Purpose: To develop transdermal patches of meloxicam (MLX) using chitosan and hydroxypropyl methylcellulose (HPMC) and polyvinyl alcohol (PVA) as hydrophilic polymers, polyamido amine (PAMAM) dendrimer as a permeation enhancer, and dibutyl pthalate as a plasticizerMethods: The patches were prepared by solvent casting evaporation technique using 3-factor, 3-level Box-Behnken design. The patches were evaluated for physical appearance, thickness, weight variation, folding endurance, drug content uniformity, tensile strength, moisture absorption and moisture loss, in vitro drug release, as well as by field-emission scanning electron microscopy (FESEM) and x-ray diffraction (XRD). A specially designed glass diffusion cell was used for the in vitro drug release study. The effect of concentrations of dependent variables (PAMAM G3, chitosan and dibutyl pthalate) on drug release was investigated.Results: The patches demonstrated satisfactory characteristics. PAMAM dendrimer significantly enhanced (p < 0.5) the permeation of MLX. A maximum of 85.7 % drug release was achieved in 24 h.Conclusion: Dendrimer increased the release of MLX by increasing its solubility and permeation through the membrane. Thus, dendrimer patches are a potentially suitable transdermal drug delivery system for the management of some diseased conditions.Keywords: Dendrimers, Transdermal patches, Skin permeation, Permeation enhancer, Chitosan, Hydroxypropyl methyl cellulose, Meloxicam, Plasticize
Management of an incidental finding of right internal jugular vein agenesis
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Effect of nickel on the microstructure and mechanical property of die-cast AlâMgâSiâMn alloy
The effect of nickel on the microstructure and mechanical properties of a die-cast AlâMgâSiâMn alloy has been investigated. The results show that the presence of Ni in the alloy promotes the formation of Ni-rich intermetallics. These occur consistently during solidification in the die-cast AlâMgâSiâMn alloy across different levels of Ni content. The Ni-rich intermetallics exhibit dendritic morphology during the primary solidification and lamellar morphology during the eutectic solidification stage. Ni was found to be always associated with iron forming AlFeMnSiNi intermetallics, and no Al3Ni intermetallic was observed when Ni concentrations were up to 2.06 wt% in the alloy. Although with different morphologies, the Ni-rich intermetallics were identified as the same AlFeMnSiNi phase bearing a typical composition of Al[100â140](Fe,Mn)[2â7]SiNi[4â9]. With increasing Ni content, the spacing of the α-AlâMg2Si eutectic phase was enlarged in the AlâMgâSiâMn alloy. The addition of Ni to the alloy resulted in a slight increase in the yield strength, but a significant decrease in the elongation. The ultimate tensile strength (UTS) increased slightly from 300 to 320 MPa when a small amount (e.g. 0.16 wt%) of Ni was added to the alloy, but further increase of the Ni content resulted in a decrease of the UTS.The Engineering and Physical Sciences Research Council (EPSRC), Technology Strategy Board (TSB) and Jaguar Land Rover (JLR) in the United Kingdom
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Argo real-time quality control intercomparison
The real-time quality control (RTQC) methods applied to Argo profiling float data by the United Kingdom (UK) Met Office, the United States (US) Fleet Numerical Meteorology and Oceanography Centre, the Australian Bureau of Meteorology and the Coriolis Centre are compared and contrasted. Data are taken from the period 2007 to 2011 inclusive and RTQC performance is assessed with respect to Argo delayed-mode quality control (DMQC). An intercomparison of RTQC techniques is performed using a common data set of profiles from 2010 and 2011. The RTQC systems are found to have similar power in identifying faulty Argo profiles but to vary widely in the number of good profiles incorrectly rejected. The efficacy of individual QC tests are inferred from the results of the intercomparison. Techniques to increase QC
performance are discussed
Toxicological evaluation of precocene II isolated from Ageratum conyzoides L. (Asteraceae) in Sprague Dawley rats
Precocene II (6,7-dimethoxy-2,2-dimethyl-2-chromene) was the main constituent isolated from Ageratum conyzoides L. and reportedly possessed antifungal activity. The study investigated the isolation,purification and toxicological effects of precocene II from A. conyzoides in Sprague Dawley rats. Precocene II was isolated from the petroleum ether fraction of the plant and the structure was determined by  1H-,13C-,DEPT-NMR and MS spectral techniques. Three groups of eight rats per group were used for the study. While groups B and C were respectively administered with 25 and 50 mg/kg of precocene II in 0.25% CMC-Na for 11 days by gastric intubation, group A was administered with 0.25% CMC-Na and served as the control group. After the last treatment, animals were fasted overnight and on the 12th day, they were injected intravenously with 0.2 ml/kg body weight of phenobarbital. Animalswere subsequently dissected from the abdominal region; blood was collected from the pulmonary vein into EDTA anti-coagulated and non anti-coagulated tubes. The liver, kidney and spleen tissues wereextracted into separate bottles for histopathological examinations. Results from hematological study indicated that the white blood cell (WBC), red blood cell (RBC), plateletcrit (PCT) and mean corpuscular hemoglobin count (MCHC) were significantly higher across the treated group s. Biochemical result showed that serum glucose level was significantly reduced in the treated groups. No apparent damage was noticed in the liver, kidney and spleen tissues. The result therefore suggests that precocene II possesses hypoglycemic property and could alter some hematopoietic elements but was not toxic to the liver, kidney and spleen tissues
An electro-hydrodynamics modeling of droplet actuation on solid surface by surfactant-mediated electro-dewetting
We propose an electro-hydrodynamics model to describe the dynamic evolution
of a slender drop containing a dilute ionic surfactant on a naturally wettable
surface, with a varying external electric field. This unified model reproduces
fundamental microfluidic operations controlled by electrical signals, including
dewetting, rewetting, and droplet shifting. In this paper, lubrication theory
analysis and numerical simulations illustrate how to electrically control the
wettability of surface via the charged surfactant. Our numerical results show
that electric field promotes dewetting by attracting ionic surfactants onto the
transition thin-film region and promotes rewetting by attracting them away from
the region.Comment: 16 pages, 13 figure
A two-component regulatory system modulates twitching motility in Dichelobacter nodosus
© 2015 Elsevier B.V. All rights reserved. Dichelobacter nodosus is the essential causative agent of footrot in sheep and type IV fimbriae-mediated twitching motility has been shownto be essential for virulence.Wehave identified a two-component signal transduction system (TwmSR) that shows similarity to chemosensory systems from other bacteria. Insertional inactivation of the gene encoding the response regulator, TwmR, led to a twitching motility defect, with the mutant having a reduced rate of twitching motility when compared to the wild-type and a mutant complemented with the wild-type twmR gene. The reduced rate of twitching motility was not a consequence of a reduced growth rate or decreased production of surface located fimbriae, but video microscopy indicated that it appeared to result from an overall loss of twitching directionality. These results suggest that a chemotactic response to environmental factors may play an important role in the D. nodosus-mediated disease process
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