20 research outputs found
Finite element computation of multi-physical micropolar transport phenomena from an inclined moving plate in porous media
Non-Newtonian flows arise in numerous industrial transport processes including materials fabrication systems.
Micropolar theory offers an excellent mechanism for exploring the fluid dynamics of new non-Newtonian materials which possess internal microstructure. Magnetic fields may also be used for controlling electrically-conducting polymeric flows. To explore numerical simulation of transport in rheological materials processing, in the current paper, a finite element computational solution is presented for magnetohydrodynamic (MHD), incompressible, dissipative, radiative and chemically-reacting micropolar fluid flow, heat and mass transfer adjacent to an inclined porous plate embedded in a saturated homogenous porous medium. Heat generation/absorption effects are included. Rosseland’s diffusion approximation is used to describe the radiative heat flux in the energy equation. A Darcy model is employed to simulate drag effects in the porous medium. The governing transport equations are rendered into non-dimensional form under the assumption of low Reynolds number and also low magnetic Reynolds number. Using a Galerkin formulation with a weighted residual scheme, finite element solutions are presented to the boundary value problem. The influence of plate inclination, Eringen coupling number, radiation-conduction number, heat absorption/generation parameter, chemical reaction parameter, plate moving velocity parameter, magnetic parameter, thermal Grashof number, species (solutal) Grashof number, permeability parameter, Eckert number on linear velocity, micro-rotation, temperature and concentration profiles. Furthermore, the influence of selected thermo-physical parameters on friction factor, surface heat transfer and mass transfer rate is also tabulated. The finite element solutions are verified with solutions from several limiting cases in the literature. Interesting features in the flow are identified and interpreted
Antiinflammatory and antiulcer activities of phytic acid in rats
179-185Maximum antiinflammatory activity of
phytic acid (PA) was seen at an oral dose of 150 mg/kg in the carrageenan induced
rat paw edema model. Although PA showed ability to prevent denaturation of
proteins, it showed less antiinflammatory activity than ibuprofen. Ability of
PA, to bring down thermal denaturation of proteins might be a contributing
factor in the mechanism of action against inflammation. PA, at all the doses
tested, showed significant protection from ulcers induced by ibuprofen, ethanol
and cold stress, with a maximum activity at 150 mg/kg. There was a significant
increase in gastric tissue malondialdehyde levels in ethanol treated rats but
these levels decreased following PA
pretreatment. Moreover, pretreatment with
PA significantly inhibited various effects of ethanol on gastric mucosa, such as,
reduction in the concentration of nonprotein sulfhydryl groups, necrosis,
erosions, congestion and hemorrhage. These results suggested that
gastro-protective effect of PA could be mediated by its antioxidant activity and
cytoprotection of gastric mucosa
Magnetically Recyclable Nano-Fe<sub>2</sub>O<sub>3</sub>-Catalyzed Chemoselective Synthesis and Antioxidant Activity of Diethyl (3-((5-Aryl-1<i>H</i>-1,2,4-triazol-3-yl)thio)propyl)phosphonates
<div><p></p><p>An efficient, green, and chemoselective S-alkylation of 5-aryl-1<i>H</i>-1,2,4-triazole-3-thiones with diethyl (3-bromopropyl)phosphonate in water, catalyzed by nano-Fe<sub>2</sub>O<sub>3</sub> under ligand- and base-free conditions, is reported. Clean reaction, less expensive catalyst, excellent yields, and easy workup are the advantages of the present method. The catalyst can be easily collected by a magnet and recycled without significant loss in catalytic activity. The newly synthesized compounds were screened for their antioxidant property by using 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay. The majority of the compounds exhibited good antioxidant activity.</p>
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Predictors of acute kidney injury in patients undergoing adult cardiac surgery
Background: Acute kidney injury (AKI) after cardiac surgery (CS) is not uncommon and has serious effects on mortality and morbidity. A majority of patients suffer mild forms of AKI. There is a paucity of Indian data regarding this important complication after CS. Aims and Objectives: The primary objective was to study the incidence of AKI associated with CS in an Indian study population. Secondary objectives were to describe the risk factors associated with AKI-CS in our population and to generate outcome data in patients who suffer this complication. Methods: Serial patients (n = 400) presenting for adult CS (emergency/elective) at a tertiary referral care hospital in South India from August 2016 to November 2017 were included as the study individuals. The incidence of AKI-CS AKI network (AKIN criteria), risk factors associated with this condition and the outcomes following AKI-CS are described. Results: Out of 400, 37 (9.25%) patients developed AKI after CS. AKI associated with CS was associated with a mortality of 13.5% (no AKI group mortality 2.8%, P = 0.001 [P < 0.05]). When AKI was severe enough to need renal replacement therapy, the mortality increased to 75%. Patients with AKI had a mean hospital stay 16.92 ± 12.75 days which was comparatively longer than patients without AKI (14 ± 7.98 days). Recent acute coronary syndrome, postoperative atrial fibrillation, and systemic hypertension significantly predicted the onset of AKI-CS in our population. Conclusions: The overall incidence of AKI-CS was 9.25%. The incidence of AKI-CS requiring dialysis (Stage 3 AKIN) AKI-CS was lower (2%). However, mortality risks were disproportionately high in patients with AKIN Stage 3 AKI-CS (75%). There is a need for quality improvement in the care of patients with AKI-CS in its most severe forms since mortality risks posed by the development of Stage 3 AKIN AKI is higher than reported in other index populations from high resource settings