38,325 research outputs found

    A Deep Learning Approach to Structured Signal Recovery

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    In this paper, we develop a new framework for sensing and recovering structured signals. In contrast to compressive sensing (CS) systems that employ linear measurements, sparse representations, and computationally complex convex/greedy algorithms, we introduce a deep learning framework that supports both linear and mildly nonlinear measurements, that learns a structured representation from training data, and that efficiently computes a signal estimate. In particular, we apply a stacked denoising autoencoder (SDA), as an unsupervised feature learner. SDA enables us to capture statistical dependencies between the different elements of certain signals and improve signal recovery performance as compared to the CS approach

    A refined gravity model from Lageos (GEM-L2)

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    For abstract for A83-1354

    INCIDENCES OF-AND RISK FACTOR FOR NEW ONSET DIABETES AFTER TRANSPLANTATION IN LIVE DONOR KIDNEY TRANSPLANTATION: A PROSPECTIVE SINGLE CENTRE STUDY

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    Objective: The objective of present study was to evaluate incidence and risk factors for the development of new-onset diabetes after transplantation (NODAT) after kidney transplantation at our center.Methods: A total 79 nondiabetic patients who underwent living donor kidney transplantation from January 2014 to August 2014 were prospectively enrolled. All the patients were followed for one year. All the patients received the same protocol of immunosuppressive therapy. NODAT was defined as if a patient had HbA1c ≥ 6.5%, fasting venous plasma glucose ≥126 mg/dl, or was receiving diet or medical therapy for diabetes.Results: The incidence of NODAT was 29.9% after one year. Risk factors associated with the development of NODAT included older age (OR: 1.07; p<0.05), family history (OR: 3.58; P<0.05), hepatitis C virus (HCV) positivity (OR: 11.15; p<0.05), obesity (OR: 4.28; p<0.05), pre-transplant triglycerides (OR: 1.01; p<0.005) and cholesterol level (OR: 1.01; p<0.005).Conclusion: The prevalence of potentially modifiable risk factors in our study cohort was overweight recipients and pretransplant HCV infection, serum triglycerides, and cholesterol levels.Keywords: New-onset Diabetes after transplantation, Kidney transplantation, Tacrolimus, Hepatitis C virus

    MULTIPLE UNIT PELLET SYSTEM (MUPS) BASED FAST DISINTEGRATING DELAYED-RELEASE TABLETS FOR PANTOPRAZOLE DELIVERY

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    Objective: The rationale for the study was to develop multiple unit pellet system (MUPS) of delayed release pantoprazole with desired physical properties and unaltered drug release profile from pellets even after compression into a fast disintegrating tablet.Methods: In the presented study, delayed release pellets of pantoprazole were developed by two methods, i.e. extrusion-spheronization and drug layering techniques, coated using enteric polymer and subsequently compressed in to tablet. In drug layering technique, pantoprazole was loaded on Celphere®102 (microcrystalline cellulose spheres) as well as on Suglet® (sugar spheres) in fluid bed processor. Acid resistant polymer Eudragit ND 30D was subsequently coated on each type of drug loaded pellets. Suitable tableting excipients were prepared such as soft pellets, Ceolus® (fibrous grade of microcrystalline cellulose) granules, Ludipress® (compressible lactose composition), Avicel® PH 200 and different combination of them. Various factors like property of pellets to be compressed, coating level, the composition of tableting excipient and ratio of drug-loaded pellets to tableting excipients were identified and optimized.Results: MUPS with delayed releasing pellets of pantoprazole proved to provide sufficient hardness, rapid disintegration property, and unaltered release profile after compression. Delayed release pantoprazole pellets prepared by drug layering on celphere® 102 followed by coating with Eudragit® NE 30D showed better compressibility to withstand the drug release properties. The combination of Ceolus® granules and Ludipress (in 1:1 ratio) was found to be suitable tableting excipient that helped compression of pellets without rupturing polymeric coat. Pellets to excipients ratio at 1:3 was found optimum.Conclusion: Compaction behaviour of pantoprazole delayed-release pellets without loss of original delayed release profile was achieved by formulating as MUPS based tablet of pantoprazole delayed release pellets using celephere® 102 was developed which was found suitable for desired release profile and physical properties

    Improving the Isotretinoin Photostability by Incorporating in Microemulsion Matrix

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    The present paper demonstrates the increased photostability of isotretinoin when loaded in microemulsion. The photodegradation of isotretinoin, in methanol and microemulsion formulation was studied under direct sun light. The photodegradation process was monitored by UV spectrophotometry. In methanol solution, isotretinoin undergoes complete photodegradation just within a few minutes of light exposure. Isotretinoin incorporated in microemulsion formulation showed an increased stability in comparison to the methanol solutions. In particular for isotretinoin, a residual concentration of 75% was still present after a light irradiance versus a residual value of just 16% measured at the same time in methanol solution. Further, degradation kinetic parameters of isotretinoin-loaded microemulsion formulation were demonstrated increase isotretinoin half-life about five-times in comparison with a methanol solution under a direct sun light

    Crystals in Materials Science

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    The GEM-T2 gravitational model

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    The GEM-T2 is the latest in a series of Goddard Earth Models of the terrestrial field. It was designed to bring modeling capabilities one step closer towards ultimately determining the TOPEX/Poseidon satellite's radial position to an accuracy of 10-cm RMS (root mean square). It also improves models of the long wavelength geoid to support many oceanographic and geophysical applications. The GEM-T2 extends the spherical harmonic field to include more than 600 coefficients above degree 36 (which was the limit for its predecessor, GEM-T1). Like GEM-T1, it was produced entirely from satellite tracking data, but it now uses nearly twice as many satellites (31 vs. 17), contains four times the number of observations (2.4 million), has twice the number of data arcs (1132), and utilizes precise laser tracking from 11 satellites. The estimation technique for the solution has been augmented to include an optimum data weighting procedure with automatic error calibration for the gravitational parameters. Results for the GEM-T2 error calibration indicate significant improvement over previous satellite-only models. The error of commission in determining the geoid has been reduced from 155 cm in GEM-T1 to 105 cm for GEM-T2 for the 36 x 36 portion of the field, and 141 cm for the entire model. The orbital accuracies achieved using GEM-T2 are likewise improved. Also, the projected radial error on the TOPEX satellite orbit indicates 9.4 cm RMS for GEM-T2, compared to 24.1 cm for GEM-T1

    Dynamic sea surface topography, gravity and improved orbit accuracies from the direct evaluation of SEASAT altimeter data

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    A method for the simultaneous solution of dynamic ocean topography, gravity and orbits using satellite altimeter data is described. A GEM-T1 based gravitational model called PGS-3337 that incorporates Seasat altimetry, surface gravimetry and satellite tracking data has been determined complete to degree and order 50. The altimeter data is utilized as a dynamic observation of the satellite's height above the sea surface with a degree 10 model of dynamic topography being recovered simultaneously with the orbit parameters, gravity and tidal terms in this model. PGS-3337 has a geoid uncertainty of 60 cm root-mean-square (RMS) globally, with the uncertainty over the altimeter tracked ocean being in the 25 cm range. Doppler determined orbits for Seasat, show large improvements, with the sub-30 cm radial accuracies being achieved. When altimeter data is used in orbit determination, radial orbital accuracies of 20 cm are achieved. The RMS of fit to the altimeter data directly gives 30 cm fits for Seasat when using PGS-3337 and its geoid and dynamic topography model. This performance level is two to three times better than that achieved with earlier Goddard earth models (GEM) using the dynamic topography from long-term oceanographic averages. The recovered dynamic topography reveals the global long wavelength circulation of the oceans with a resolution of 1500 km. The power in the dynamic topography recovery is now found to be closer to that of oceanographic studies than for previous satellite solutions. This is attributed primarily to the improved modeling of the geoid which has occurred. Study of the altimeter residuals reveals regions where tidal models are poor and sea state effects are major limitations
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