279 research outputs found
2-MethÂoxy-4-methyl-1-[1-(phenylÂsulfonÂyl)propan-2-yl]benzene
The title molÂecule, C17H20O3S, displays a U-shaped structure; the two benzene rings are nearly parallel and partially overlapped to each other, the dihedral angle and centroid-to-centroid distance being 15.0 (2)° and 3.723 (2) Å. In the crystal, weak interÂmolecular C—H⋯O hydrogen bonds link the molÂecules, forming supraÂmolecular chains running along the a axis
Diclofenac transdermal patch versus the sustained release tablet: A randomized clinical trial in rheumatoid arthritic patients
Purpose: To prepare and characterize transdermal films of diclofenac diethanolamine as a safer and more effective alternative than the sustained release (SR) tablet equivalent for prolonged relief from pain and inflammation in arthritis.Methods: Transdermal films of diclofenac were prepared using sodium carboxymethyl cellulose and polyvinyl pyrrolidone K30, with turpentine oil and sesame oil as penetration enhancers. The films were characterized for physicochemical properties and for ex vivo permeation in a randomized clinical trial(RCT) for analgesic activities in arthritic patients.Results: The transdermal films were uniform in weight and thickness, flat, with high drug content (94.40 ± 1.04 to 98.62 ± 1.08 %) and with high folding endurance (149 ± 9.09 to 192 ± 10.12). Drug permeation through excised rat abdominal skin was prolonged. Films containing penetration enhancers showed higher ex vivo drug permeation than those without the enhancer; furthermore, drug permeation increased with increase in the concentration of enhancer. The films were non-irritating to the skin. In RCT, F3 (containing turpentine oil, 1 %v/w) decreased the pain score from 9.87 ± 1.14 to 4.94 ± 0.78 units, compared with the SR tablet (once daily) which decreased pain from 9.59 ± 0.42 to 6.49 ± 1.20 units, 48 h post-administration. Turpentine oil showed better permeation enhancement than sesame oil in the transdermal films.Conclusion: Transdermal films of diclofenac, formulated with permeation enhancers, may have greater therapeutic advantages over conventional oral tablets in terms of prolonged release and improvement of patient compliance in rheumatoid arthritis.Keywords: Analgesic activity, Diclofenac, Permeation enhancer, Rheumatoid arthritis, Transdermal film
Risk factors and outcomes of postoperative pancreatic fistula after pancreatico-duodenectomy: an audit of 532 consecutive cases
Revisiting Image Aesthetic Assessment via Self-Supervised Feature Learning
Visual aesthetic assessment has been an active research field for decades.
Although latest methods have achieved promising performance on benchmark
datasets, they typically rely on a large number of manual annotations including
both aesthetic labels and related image attributes. In this paper, we revisit
the problem of image aesthetic assessment from the self-supervised feature
learning perspective. Our motivation is that a suitable feature representation
for image aesthetic assessment should be able to distinguish different
expert-designed image manipulations, which have close relationships with
negative aesthetic effects. To this end, we design two novel pretext tasks to
identify the types and parameters of editing operations applied to synthetic
instances. The features from our pretext tasks are then adapted for a one-layer
linear classifier to evaluate the performance in terms of binary aesthetic
classification. We conduct extensive quantitative experiments on three
benchmark datasets and demonstrate that our approach can faithfully extract
aesthetics-aware features and outperform alternative pretext schemes. Moreover,
we achieve comparable results to state-of-the-art supervised methods that use
10 million labels from ImageNet.Comment: AAAI Conference on Artificial Intelligence, 2020, accepte
Progress and outlook on advanced fly scans based on Mamba
Development related to PandABox-based fly scans is an important part of the
active work on Mamba, the software framework for beamline experiments at the
High Energy Photon Source (HEPS); presented in this paper is the progress of
our development, and some outlook for advanced fly scans based on knowledge
learned during the process. By treating fly scans as a collaboration between a
few loosely coupled subsystems - motors / mechanics, detectors / data
processing, sequencer devices like PandABox - systematic analyses of issues in
fly scans are conducted. Interesting products of these analyses include a
general-purpose software-based fly-scan mechanism, a general way to design
undulator-monochromator fly scans, a sketch of how to practically implement
online tuning of fly-scan behaviours based on processing of the data acquired,
and many more. Based on the results above, an architectural discussion on
>=10kHz fly scans is given.Comment: 10 pages, 6 figures, accepted by Synchrotron Rad. New
Theoretical and experimental study on vertical dynamic characteristics of six-axle heavy-haul locomotive on curve
This paper presents a method to study the vertical dynamic characteristics of a heavy-haul locomotive in curve. A quasi-static analysis model based on the static force equilibrium relationship is established to investigate the load bearing characteristics of suspension system when the locomotive runs through the curve. Then a locomotive–track coupled dynamics model is used to analyse the dynamic characteristics of wheel load in curves. Finally, a field test in curve is carried out to validate the simulated results. The theoretical analysis results indicate that due to the different twist shapes of track on the entry and exit transition curves, for some specific position in the suspension system or wheel arrangements, the corresponding vertical load along the curve length presents an asymmetry about the section of circular curve. The asymmetry is predominantly caused by the Superelevation Angle Differences (SADs) between car body, bogie frames and wheelsets. A distinct phenomenon is that the outer wheel–rail vertical load of the first axle increases when the locomotive enters the transition curve and then reduces when it exits. These results are expected to provide theoretical guidance to the design of the heavy-haul railways. It is suggested that the asymmetric characteristics of the wheel loads can be improved by some measures, such as adopting a low vertical stiffness in the secondary suspension and increasing the transition curve length.
First published online 04 May 201
Local melting to design strong and plastically deformable bulk metallic glass composites
Recently, CuZr-based bulk metallic glass (BMG) composites reinforced by the TRIP (transformation-induced plasticity) effect have been explored in attempt to accomplish an optimal of trade-off between strength and ductility. However, the design of such BMG composites with advanced mechanical properties still remains a big challenge for materials engineering. In this work, we proposed a technique of instantaneously and locally arc-melting BMG plate to artificially induce the precipitation of B2 crystals in the glassy matrix and then to tune mechanical properties. Through adjusting local melting process parameters (i.e. input powers, local melting positions, and distances between the electrode and amorphous plate), the size, volume fraction, and distribution of B2 crystals were well tailored and the corresponding formation mechanism was clearly clarified. The resultant BMG composites exhibit large compressive plasticity and high strength together with obvious work-hardening ability. This compelling approach could be of great significance for the steady development of metastable CuZr-based alloys with excellent mechanical properties
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