Generation of tunable, high repetition rate optical frequency combs using on-chip silicon modulators

We experimentally demonstrate tunable, highly-stable frequency combs with high repetition-rates using a single, charge injection based silicon PN modulator. In this work, we demonstrate combs in the C-band with over 8 lines in a 20-dB bandwidth. We demonstrate continuous tuning of the center frequency in the C-band and tuning of the repetition-rate from 7.5GHz to 12.5GHz. We also demonstrate through simulations the potential for bandwidth scaling using an optimized silicon PIN modulator. We find that, the time varying free carrier absorption due to carrier injection, an undesirable effect in data modulators, assists here in enhancing flatness in the generated combs.Comment: 10 pages, 7 figure

Studies on Formulation and Evaluation of Ethyl Cellulose Based Extended Release Metformin Hydrochloride Matrix Tablets

Monolithic matrix tablets of metformin hydrochloride were formulated as extended release tablets by employing ethyl cellulose polymer and the extended release characterization of the formulated tablets was investigated.  Extended release matrix tablets containing 500 mg metformin hydrochloride were developed by changing concentration of drug :  polymer (EC) in the ratio of 5:1, 5:2, 5:3 and 5:4 by direct compression.  Formulations were optimized based on the acceptable tablet properties invitro and invivo drug release.  The resulting formulations produced robust tablets with optimum hardness, weight variation, drug content and low friability.  The result of invitro and invivo drug release studies indicated that formulation (drug:polymer =5:3), is the most successful of the study and exhibited constant and extended release of metformin hydrochloride 99-100.5% release at the end of 10 h compared with reference standard.  Further, the formulation F3 was subjected to exposure at room and accelerated condition to stability studies.  A decrease in release of the drug was observed on increasing polymer ratio at certain level.  Before tablet compression, the resulting formulation blends were evaluated for angle of repose, bulk density, % porosity, % compressibility index and drug polymer compatibility study of drug and excipients.  The t25, t50 and t90 drug release values was calculated from selected formulation F3 on every month of stability studies and comparision of both room and accelerated condition by statistical t-test, there is no difference between storage temperature. The formulation F3 was showed similar invitro and invivo drug release when compared to marketed sustained release tablet (F5M)

ANTI-INFLAMMATORY ACTIVITY OF CURCUMIN AND CAPSAICIN AUGMENTED IN COMBINATION

Objective: Dietary curcumin and capsaicin are well known for their health beneficial potencies. The current study was done to assess the anti-inflammatory activity of curcumin, capsaicin and their combination by employing in vitro and in vivo models.Methods: We investigated the protective effect of curcumin, capsaicin and their combination using in vitro heat induced human red blood cell (HRBC) membrane stabilisation, in vivo 3% agar induced leukocyte mobilisation and acetic acid induced vascular permeability assay.Results: Curcumin, capsaicin and their combination exhibited concentration dependent protective effect against heat-induced HRBC membrane destabilisation, while combined curcumin and capsaicin restored 87.0±0.64 % membrane stability and it is found to be better than curcumin, capsaicin and diclofenac sodium (75.0±0.25. 72±0.9 and 80.0±0.31 %) protective effect. In agar suspension induced leukocyte mobilization assay, the combined curcumin and capsaicin had shown 39.5±1.58 % of inhibition compared to individual curcumin and capsaicin, which showed moderate inhibition of 16.0±3.14 and 21.6±2.17 % respectively. Besides, the combined curcumin and capsaicin had shown highly significant inhibition of acetic acid-induced vascular permeability in rats (62.0±3.14 %), whereas individual curcumin and capsaicin showed moderate inhibition of vascular permeability with 36.0±2.41 and 43.0±1.92 % respectively.Conclusion: This study demonstrates the significant anti-inflammatory property of combined curcumin and capsaicin at half of the individual concentration of curcumin and capsaicin

A Review of Research Projects done by Under-Graduate Medical Students over a Period of Fifteen Years in a Medical College in Coimbatore

Background: As per Medical Council of India guidelines, Under-graduate medical students must involve in planning, implementation and evaluation of a health education program. Problem Solving for Better Health (PSBH) is an excellent opportunity provided to fulfill this objective. PSBH participants are encouraged to generate new ideas and methods to more effectively utilize the resources that are currently available to them to help solve specific health problems in their areas. Many of the PSBH projects are Health Education Intervention projects and Behavior change is the core idea of Health Education. We intend to assess the projects documenting behavior change following Health Education Intervention.Methods: Abstract, Objectives, Methodology, Results, Discussion and Questionnaires of the submitted Health Education Intervention projects were reviewed for data on the Knowledge, Attitude, Practice, and Change in Behavior of participants before and after Health Education Intervention. Data entered in Epi-Info 6.0 and percentage projects showing Knowledge, Attitude and Behavioral change were assessed.Results: Out of the 243 PSBH projects 177(72.83%) were Health Education Intervention projects. Behavioral assessment before intervention was done in 152(85.87%) studies. 88(49.71%) studies have documented the changes in behavior after intervention and only 38 out of these 88 studies have documented the statistical significance for the change in behavior. 2(0.01%) of the studies have used Health Education Models other than Knowledge Attitude Practice (KAP) Model. Convenient sampling is done in all the studies.Conclusion: Nearly half of the PSBH projects on Health Education Intervention have documented the change in behavior. The use of appropriate Health Education Models, standard sampling methods, proper statistical analysis and documenting change in Behavior will add value for their study

STUDY OF GROWTH PROMOTING EFFECTS OF AYU-707 - A POLYHERBAL POWDER IN IMMATURE RATS

ABSTRACTObjective: The growth promoting effects of AYU-707 was investigated in 1 and 2 months immature rats.Methods: The AYU-707 was administered orally at a dose of 5 (1-month-old rats) and 6.5 g/kg body weight (BW) (2-month-old rats) for 45 days.During and end of the study, BW, tail length, body circumference, and feed efficiency were determined. After 24 hrs of the last treatment, the bloodwas withdrawn by retro-orbital puncture and blood, hemoglobin, serum alkaline phosphatase, serum glutamate-oxaloacetate transaminase, serumglutamic-pyruvic transaminase, calcium, total protein, and amylase were estimated. Then, the rats were sacrificed by overdose ketamine and thefemur weight, tibial density, bone hydroxyproline content, and epiphyseal plate width were determined. Then, the spleen, lung, liver, kidney, heart,and uterus weights were determined.Results: The preliminary phytochemical investigation confirms the presence of carbohydrate, amino acid, alkaloids, flavonoids, and tannins in AYU707powder.The ratstreatedwith AYU-707haveshownsignificantdifferencesin most of the growthenhancementparameterswhencomparedtothenormal rats.Conclusion: From the results of the present study, it is concluded that AYU-707 formulated by M/s Ayurwin Pharma Pvt. Ltd., Bengaluru, possessessuperior anabolic and growth promotion properties that may serve to promote the growth in children associated with growth-related disorders.Keywords: Body circumference, Tibial density, Flavonoids, Hydroxyproline, Epiphyseal plate

Asymmetry to symmetry transition of Fano line-shape: Analytical derivation

An analytical derivation of Fano line-shape asymmetry ratio has been presented here for a general case. It is shown that Fano line-shape becomes less asymmetric as \q is increased and finally becomes completely symmetric in the limiting condition of q equal to infinity. Asymmetry ratios of Fano line-shapes have been calculated and are found to be in good consonance with the reported expressions for asymmetry ratio as a function of Fano parameter. Application of this derivation is also mentioned for explanation of asymmetry to symmetry transition of Fano line-shape in quantum confined silicon nanostructures.Comment: 3 figures, Latex files, Theoretica