275 research outputs found

    DEVELOPMENT OF OLMESARTAN MEDOXOMIL-LOADED CHITOSAN MICROPARTICLES: A POTENTIAL STRATEGY TO IMPROVE PHYSICOCHEMICAL AND MICROMERITIC PROPERTIES

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    Objective: The objective of the present research was to improve physicochemical and micromeritic properties of Olmesartan Medoxomil (OLM), BCS class II antihypertensive drug by loading in Chitosan (CH) microparticles.Methods: The 32 full factorial design was assigned for microparticles prepared by single emulsion technique method using CH, a natural polymer and Glutaraldehyde (GA) as cross linking agent. Developed microparticles were characterized for Micromeritic properties, morphology by Scanning Electron Microscopy (SEM), drug entrapment efficiency, in vitro drug release, and interaction studies Fourier transfer infrared spectroscopy (FTIR) & Differential Scanning Calorimetry (DSC), drug crystallinity study by X-ray diffractometry (XRD) & DSC.Results: Maximum entrapment efficiency was found 61.76% for maximal CH and lower GA concentration. Saturation solubility of microparticles was increased by 13.74 times to that of pure OLM. FTIR showed compatibility between drug and polymer. XRD, DSC and SEM studies confirmed reduction in crystallinity of drug. It led to increase in dissolution profile of the drug and showed 92.61% of drug release in 120 min. These microparticle preparations also helped in improving micromeritic properties like bulk density, tapped density, the angle of repose, Hausner's ratio and Carr's index.Conclusion: The results obtained in the present work demonstrate the potential use of CH to modulate physicochemical and micromeritic properties of OLM especially obtaining significant improvement in dissolution rate. Â

    Momentum-dependent relaxation dynamics of the doped repulsive Hubbard model

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    We study the dynamical behavior of doped electronic systems subject to a global ramp of the repulsive Hubbard interaction. We start with formulating a real-time generalization of the fluctuation-exchange approximation. Implementing this numerically, we investigate the weak-coupling regime of the Hubbard model both in the electron-doped and hole-doped regimes. The results show that both local and nonlocal (momentum-dependent) observables evolve toward a thermal state, although the temperature of the final state depends on the ramp duration and the band filling. We further reveal a momentum-dependent relaxation rate of the distribution function in doped systems and trace back its physical origin to the anisotropic self-energies in the momentum space

    Bending and free vibration analysis of thick isotropic plates by using exponential shear deformation theory

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    This paper presents a variationally consistent an exponential shear deformation theory for the bi-directional bending and free vibration analysis of thick plates. The theory presented herein is built upon the classical plate theory. In this displacement-based, refined shear deformation theory, an exponential functions are used in terms of thickness co-ordinate to include the effect of transverse shear deformation and rotary inertia. The number of unknown displacement variables in the proposed theory are same as that in first order shear deformation theory. The transverse shear stress can be obtained directly from the constitutive relations satisfying the shear stress free surface conditions on the top and bottom surfaces of the plate, hence the theory does not require shear correction factor. Governing equations and boundary conditions of the theory are obtained using the dynamic version of principle of virtual work. The simply supported thick isotropic square and rectangular plates are considered for the detailed numerical studies. Results of displacements, stresses and frequencies are compared with those of other refined theories and exact theory to show the efficiency of proposed theory. Results obtained by using proposed theory are found to be agree well with the exact elasticity results. The objective of the paper is to investigate the bending and dynamic response of thick isotropic square and rectangular plates using an exponential shear deformation theory

    Design and Development of Saline Monitoring System Using Load cell

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    As the world population grows, the need for health care increases. In recent years, progress in medical care has been rapid due to the advancements in the field of sensors, microcontrollers and computers. A major reason for this is the combination of the two important disciplines namely medicine and engineering.                      This paper describes the development of an automatic saline monitoring system using a low cost indigenously developed load cell and GSM (Global system for mobile communication) modem. This enables the doctor or nurse on duty to monitor the saline flow rate from a distance. The Atmel16microcontroller is used for providing co-ordination action.                       Load cell which acts as a weight sensor , used to sense the weight of the bottle.  The detection of saline drop rate is quite faithful. Message about the status of the bottle is transmitted through GSM technology to a distant mobile cell for future actions as well as displayed on LCD display

    Higher order computational model considering the effects of transverse normal strain and 2-parameter elastic foundation for the bending of laminated panels

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    In this study, the authors analyze laminated composite panels supported on an elastic foundation considering the effects of transverse normal strain. A 2-parameter, i.e., Winkler and Pasternak foundation model is assumed to represent the interaction between the panels and the foundation. The theory presented here takes into account the effects of transverse shear and normal strains. The theory plots realistic distributions of the transverse shear stress through the plate thickness and satisfies the shear-free conditions at the extreme surfaces of the panel. The differential equations of the present model are obtained from the principle of virtual work. The laminated composite panel resting on the elastic foundation is analyzed for simply supported boundary conditions. For the verification purpose, the presented problems are also solved using the Reddy's model, Mindlin's model, and the classical model. Good agreement is observed between the numerical results obtained using the present model and the other models

    Second-harmonic generation in the topological multifold semimetal RhSi

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    Recent experiments in the topological Weyl semimetal TaAs have observed record-breaking second-harmonic generation (SHG), a nonlinear optical response at 2? generated by an incoming light source at ?. However, whether SHG is enhanced in topological semimetals in general is a challenging open question because their band structure entangles the contributions arising from trivial bands and topological band crossings. In this work, we circumvent this problem by studying RhSi, a chiral topological semimetal with a simple band structure with topological multifold fermions close to the Fermi energy. We measure SHG in a wide frequency window, ? [0.27,1.5]eV and, using first-principles calculations, we establish that, due to their linear dispersion, the contribution of multifold fermions to SHG is subdominant as compared with other regions in the Brillouin zone. Our calculations suggest that parts of the bands where the dispersion is relatively flat contribute significantly to SHG. As a whole, our results suggest avenues to enhance SHG responses. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by the Max Planck Society

    Markers characterizing corneal damage during aging of rat

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    Aging is a biological phenomenon that involves an increase of oxidative stress associated with gradual degradation of the structure and function of the cornea. Gender differences and subsequent deterioration of cornea is an interesting topic, especially yet few data are available concerning the impact of age, especially on the corneal. One hundred male and female Wistar albino rats ages 3, 6, 18, 24, and 30 months (n=10 equal for male and female) were used. At the time interval, cornea were investigated by light and transmission electron microscopy (TEM), immunohistochemistry of caspase 3 (casp3), glial fibrillar acidic protein(GFAP) and CD45 and  flow cytometry of DNA, bcl-2-like protein 4 (BAX), transforming growth factor beta (TGF-β) and Cd45 (lymphocyte common antigen). Light and TEM investigation  revealed apparent deterioration of atrophy of corneal epithelium with vesicular vacuolar degeneration, hyalinization of stromal collagen fibrils and swelling and degeneration of the endothelial lining the descemet's membrane. There was apparent loss of keratocytes within corneal stroma. Immunohistochemistry of casp 3 and CD45 were markedly increased manifesting cell damage. GFAP showed apparent reduction of innervation of corneal stroma and endothelium layer. Flow cytometry of DNA, Bax and TGF revealed increased apoptic cell death of cornea of 30M-old rats. We concluded that aging contributed to an apparent increase of cellular damage of different corneal region associated with alterations of cell markers

    An investigation of ontogenic development of mouth and its size in larval and juvenile of Vimba vimba

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    In this study, mouth morphological development and the importance of size of pellet food at the onset of exogenous feeding, with respect to mouth size from hatching through 60s day after hatching (DAH), were studied in larval and juvenile Vimba bream (Vimba vimba). The samples were randomly taken at 1-8 DAH, then with 2, 5, and 10 days intervals until 60 DAH (being released into the sea). Morphological examinations of mouth were followed using SEM. The lengths of upper and lower jaws as well as the size of mouth gap at 45° and 90° were calculated to estimate the size of pellet food. The larval mouth opened at 1 DAH and filiform papillae, and lips began to form at 2 DAH. The first taste buds developed at 3 DAH. The larval mouth developed a crescent shape at 4 DAH and the structure of papilla became clear. A number of neuromast cells were observed around the mouth at 8 DAH. Finally, it can be concluded that with the onset of exogenous feeding, Vimba vimba larvae is probably able to ingest and digest 110 µm pellet food since 8 DAH. Thus, since 20 DAH until the end of larval rearing period, formulated diets can only be used

    Insertion of a foldable hydrophobic IOL through the trabeculectomy fistula in cases with Microincision cataract surgery combined with trabeculectomy

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    BACKGROUND: The use of conventional foldable hydrophobic intraocular lenses (IOLs) in microincision cataract surgery (MICS) currently requires wound enlargement. We describe a combined surgical technique of MICS and trabeculectomy with insertion of a foldable IOL through the trabeculectomy fistula. METHODS: After completion of MICS through two side port incisions, a 3.2 mm keratome is used to enter the anterior chamber under the previously outlined scleral flap. An Acrysof multi piece IOL (Alcon labs, Fort Worth, Tx) is inserted into the capsular bag through this incision. The scleral flap is then elevated and a 2 × 2 mm fistula made with a Kelly's punch. The scleral flap and conjunctival closure is performed as usual. RESULTS: Five patients with primary open angle glaucoma with a visually significant cataract underwent the above mentioned procedure. An IOL was implated in the capsular bag in all cases with no intraperative complications. After surgery, all patients obtained a best corrected visual acuity of 20/20, IOL was well centered at 4 weeks follow up. The mean IOP (without any antiglaucoma medication) was 13.2 + 2.4 mm Hg at 12 weeks with a well formed diffuse filtering bleb in all the cases. CONCLUSION: The technique of combining MICS with trabeculectomy and insertion of a foldable IOL through the trabeculectomy fistula is a feasible and valuable technique for cases which require combined cataract and glaucoma surgery

    The Photo-Electrical Behavior of n-Si and p-Si/Orange Dye/ Conductive Glass Cells

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    The photo-electrical behavior of n-Si/orange dye/conductive glass and p-Si/orange dye/conductive glass sandwich type cells were investigated. In these cells crystal silicon of n-type and p-type and conductive glass (CG) electrodes were employed and the aqueous solution of organic dye (OD) was used as an electrolyte in the distilled water. Under filament lamp illumination, photo-induced open-circuit voltage and shortcircuit current exponentially dropped with time for the n-Si/orange dye/CG cell. In the p-Si/orange dye/CG cell, the photovoltaic effect was not observed. The n-Si/OD/CG cell showed high photo-electrical response under illumination. In the light-voltage/current conversion, these cells behaved as a differentiator and exhibited charge-storage properties
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