Influence of Constant Stresses on Transverse Surface Waves Between Two Elastic Media

The influence of constant stresses on velocities of propagation of transverse surface wave between two elastic media is studied, assuming the constraints at contact surfac

Design and Finite Element Analysis of Aircraft Wing using Ribs and Spars

In this paper, project detailed design of trainer aircraft wing structuremade by using CATIA. Then stress analysis of the wing structure is carried out tocompute the stresses at wing structure. The stresses are estimated by using thefinite element approach with the help of ANSYS to find out the safety factor of thestructure. In a structure like airframe, a fatigue crack may appear at the location ofhigh tensile stress. Life prediction requires a model for fatigue damageaccumulation, constant amplitude S-N (stress life) data for various stress ratiosand local stress history at the stress concentration. The response of the wingstructure will be evaluated.In this thesis, the trainer aircraft wing structure withskin, spars and ribs is considered for the detailed analysis. The wing structureconsists of 15 ribs and two spars with skin. Front spar having „I‟ section and rearspar having „C‟ section. Stress and fatigue analysis of the whole wing section iscarried out to compute the stresses and life at spars and ribs due to the appliedpressure load.In this project, the mentor aircraft wing with winglets with atdifferent angles (450 and 250) is thinking about for the itemized investigation.Static and fatigue analysis of the entire wing area is done to figure the burdens andlife at various winglet points (250 and 450) because of the applying weight load

Rheological Behavior of Aqueous Suspensions of Laponite: New Insights into the Ageing Phenomena

In this paper, ageing behavior of suspensions of laponite with varying salt concentration is investigated using rheological tools. It is observed that the ageing is accompanied by an increase in the complex viscosity. The succeeding creep experiments performed at various ages showed damped oscillations in the strain. The characteristic time-scale of the damped oscillations, retardation time, showed a prominent decrease with the age of the system. However, this dependence weakens with an increase in the salt concentration, which is known to change microstructure of the system from glass-like to gel-like. We postulate that a decrease in the retardation time can be represented as a decrease in the viscosity (friction) of the dissipative environment surrounding the arrested entities that opposes elastic deformation of the system. We believe that ageing in colloidal glass leads to a greater ordering that enhances relative spacing between the constituents thereby reducing the frictional resistance. However, since a gel state is inherently different in structure (fractal network) than that of a glass (disordered), ageing in the same does not induce ordering. Consequently, we observe inverse dependence of retardation time on age becoming weaker with an increase in the salt concentration. We analyze these results from a perspective of ageing dynamics of both glass state and gel state of laponite suspensions.Comment: 27 Pages, 12 figure

ANTIHYPERLIPIDEMIC ACTIVITY OF CASSIA FISTULA BARK USING HIGH FAT DIET INDUCED HYPERLIPIDEMIA

Objective: To study the antihyperlipidemic and anti atherosclerotic activity of Cassia fistula extracts in experimentally induced atherosclerotic rats.Methods: In this study, the antihyperlipidemic activity of Cassia fistula bark was evaluated by the administration of high fat diet. Atherosclerosis was induced in wistar rats by feeding with high cholesterol diet for 21 d. Oral feeding of cholesterol (500 mg/kg b.w./day) dissolved in coconut oil (0.5 ml/rat/day) caused an elevation in total cholesterol, LDL cholesterol, VLDL cholesterol triglycerides serum of rats.Results: Administration of Cassia fistula extracts (methanolic and ethyl acetate extract at 500 mg/kg respectively) along with high cholesterol diet reduced the raised serum level of total cholesterol, triglyceride, LDL, VLDL and increased the serum HDL level as compared to the control group (High cholesterol group). Histopathology study of heart has shown decrease in myocardial degeneration and inflammation which may be attributed to the anti atherosclerotic activity of the Cassis fistula bark extracts.Conclusion: These results suggested that Cassia fistula bark possess significant antihyperlipidemic activity.Â

SOMES: A REVIEW ON COMPOSITION, FORMULATION METHODS AND EVALUATIONS OF DIFFERENT TYPES OF “SOMES” DRUG DELIVERY SYSTEM

Many drugs are available in the market for several diseases, disorder or even for a condition, but it is difficult to select a suitable carrier to attain maximum bioavailability and potential for a potent drug. Attaining a controlled and sustained release of a drug is purely focused on the selection of a carrier (natural, synthetic and hybrid) like nanosomes. Nanosomes have become a prominent tool in the field of pharmacy. Nanosomes are small uniform structures which deliver the drug to the specific targeted site, which mainly depends upon the presence of ligands, shape, size and surface chemistry. Nanosomes are available in various types which include Niosomes, Liposomes, Electrosomes, Aquasomes, Transfersomes, Phytosomes, Enzymosomes, Ethosomes, Invasome and Sphingosomes. In general, all these nanosomes are quite similar in nature with minute differences in their vesicular characteristics and composition. This review traces various ‘somes’ composition and their role in the formulation, applications, advantages, disadvantages, common formulation procedures and evaluation parameters

Propagation of pure fetal and maternal mesenchymal stromal cells from terminal chorionic villi of human term placenta

Long term propagation of human fetal Mesenchymal Stromal Cells (MSC) in vitro has proven elusive due to limited availability of fetal tissue sources and lack of appropriate methodologies. Here, we have demonstrated the presence of fetal and maternal cells within the tips of Terminal Chorionic Villi (TCV) of normal human term placenta and we have exploited inherent differences in the adhesive and migratory properties of maternal vs. fetal cells, to establish pure MSC cultures of both cell types. The origin and purity of each culture was confirmed by X-Y chromosome-specific Fluorescence In Situ Hybridization (FISH) and Short Tandem Repeat (STR) genotyping. This is the first demonstration of fetal and maternal cells in the TCV of human term placenta and also of deriving pure fetal MSC cultures from them. The concomitant availability of pure cultures of adult and fetal MSC from one tissue provides a good system to compare genetic and epigenetic differences between adult and fetal MSCs and also to generate new models of cell based therapies in regenerative medicine

Contrast nephropathy in patients with impaired renal function: High versus low osmolar media

Contrast nephropathy in patients with impaired renal function: High versus low osmolar media. Prescription of low osmolar contrast to prevent nephrotoxicity in subjects with pre-existing renal impairment is costly and has not been clearly shown to be effective. We entered 249 subjects with a pre-contrast serum creatinine greater than 120 /xmol/liter (1.35 mg/dl) having cardiac catheterization or intravenous contrast into a randomized controlled trial comparing high and low osmolar contrast. The outcome assessed was a rise in serum creatinine repeated 48 to 72 hours after contrast. A further 117 patients entered the non-randomized prospective arm of the study. In the randomized study the serum creatinine rose by at least 25% after contrast in 8 of 117 (6.8%) given high and in 5 of 132 (3.8%) given low osmolar contrast (P > 0.05, one-tailed 95% confidence interval for the difference 3 to 7.8%). More severe renal failure (greater than 50% increase in serum creatinine) after contrast was uncommon (3.4% with high and 1.5% with low osmolar contrast). A rise in serum creatinine after contrast was significantly associated with the severity of the pre-contrast renal impairment and the presence of diabetes mellitus, but not with type of contrast. Diabetics with a serum creatinine greater than 200 µl/liter (2.25 mg/dl) pre-contrast had a highest risk of deterioration in renal function after contrast. We conclude that in patients with pre-existing renal impairment the incidence of contrast nephropathy was not significantly different comparing high osmolar and nonionic contrast. The potential benefit of nonionic contrast in moderate renal impairment is likely to be small, but trials in diabetics with severe renal impairment should be undertaken urgently

Evaluation of Outcomes following Focal Ablative Therapy for Treatment of Localised Clinically Significant Prostate Cancer in Patients >70 Years: A Multi-institute, Multi-energy 15-year Experience

PURPOSE: In older patients who do not wish to undergo watchful waiting, focal therapy could be an alternative to the more morbid radical treatment. We evaluated the role of focal therapy (FT) in patients 70 years and older as an alternative management modality. MATERIALS AND METHODS: 649 patients across 11 UK sites receiving focal high intensity focused ultrasound (HIFU) or cryotherapy between June 2006 - July 2020 reported within the UK based HIFU Evaluation and Assessment of Treatment and the International Cryotherapy Evaluation (ICE) registries were evaluated. Primary outcome was failure free survival (FFS) defined by need for more than 1 focal re-ablation, progression onto radical treatment, development of metastases, need for systemic treatment or prostate cancer specific death. This was compared to the FFS in patients undergoing radical treatment via a propensity score weighted analysis. RESULTS: Median age was 74 years (IQR: 72, 77) and median follow-up 24 months (IQR: 12, 41). 60% had intermediate risk disease and 35% high risk disease. 113 patients (17%) required further treatment. 16 had radical treatment and 44 required systemic treatment. FFS was 82% (95% CI: 76-87%) at 5 years. Comparing patients who had radical therapy to those who had focal therapy, 5-year FFS was 96%, (95% CI: 93-100%) and 82% (95% CI: 75-91%) respectively, P < .001. 93% of those in the radical treatment arm had received Radiotherapy as their primary treatment with its associated use of Androgen Deprivation Therapy (ADT) thereby leading to potential over estimation of treatment success in the radical treatment arm, especially given the similar metastases free and overall survival rates seen. CONCLUSIONS: We propose FT to be an effective management option for the older or comorbid patient who is unsuitable for or not willing to undergo radical treatment

Identification of Ventricular Tachycardia Using Intracavitary Ventricular Electrograms: Analysis of Time and Frequency Domain Patterns

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74961/1/j.1540-8159.1988.tb06279.x.pd