366 research outputs found

    Secondary Flow and Heat Transfer of Two Incompressible Immiscible Fluids Between Two Parallel Plates in a Rotating System

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    When a straight channel formed by two parallel plates, through which two immiscible fluids are flowing under constant pressure gradients is rotated about an axis perpendicular to the plates, secondary motion is set up. The secondary motion is analysed in detail for constant angular velocity ohm', lambda the ratio of their viscosities. The associated heat transfer problems, when the plate temperatures are equal and different, have also been studied

    Quenching of fluorescence of aromatic molecules by graphene due to electron transfer

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    Investigations on the fluorescence quenching of graphene have been carried out with two organic donor molecules, pyrene butanaoic acid succinimidyl ester (PyBS, I) and oligo(p-phenylenevinylene) methyl ester (OPV-ester, II). Absorption and photoluminescence spectra of I and II recorded in mixture with increasing the concentrations of graphene showed no change in the former, but remarkable quenching of fluorescence. The property of graphene to quench fluorescence of these aromatic molecules is shown to be associated with photo-induced electron transfer, on the basis of fluorescence decay and time-resolved transient absorption spectroscopic measurements.Comment: 18 pages, 6 figure

    Low bit Rate Video Quality Analysis Using NRDPF-VQA Algorithm

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    In this work, we propose NRDPF-VQA (No Reference Distortion Patch Features Video Quality Assessment) model aims to use to measure the video quality assessment for H.264/AVC (Advanced Video Coding). The proposed method takes advantage of the contrast changes in the video quality by luminance changes. The proposed quality metric was tested by using LIVE video database. The experimental results show that the new index performance compared with the other NR-VQA models that require training on LIVE video databases, CSIQ video database, and VQEG HDTV video database. The values are compared with human score index analysis of DMOS

    Performance Analysis of No Reference Image quality based on Human Perception

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    In this work, a No-Reference objective image quality assessment based on NRDPF-IQA metric and classification based metric are tested using LIVE database, which consisting of Gaussian white noise, Gaussian blur, Rayleigh fast fading channel, JPEG compressed images, JPEG2000 images. We plot the Spearman’s Rank Order Correlation Coefficient [SROCC] between each of these features and human DMOS from the LIVE-IQA database using our proposed method to ascertain how well the features correlate with human judgement quality. The analysis of the testing and training is done by SVM model. The proposed method shows better results compared with the earlier methods. Finally, the results are generated by using MATLAB.DOI:http://dx.doi.org/10.11591/ijece.v4i6.678

    FORMULATION AND EVALUATION OF TAFLUPROST OPHTHALMIC SOLUTION

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    The aim of the present study was to formulate, develop and evaluate ophthalmic solution containing Tafluprost. The selected prostaglandin analogue belongs to BCS - II. So to increase the solubility of the Tafluprost in WFI Beta Cyclodextrin was used by performing various trials variables of the experiments procedure Stirring time and speed were optimized to enhance the solubility. From the experimental procedure with different trails 20mg/mL of Cyclodextrins was fixed for the optimized formula. The product were characterized for appearance, physical state, colour and odour of the drug characteristics. The prepared formulations were evaluated for pH, osmolality and assay and found to be in acceptable ranges. Stability study was carried out for optimized formulation at 40°C±2°C /NMT 25%RH and 30°C ±2°C/ 65%±5% RH for 3 months, were evaluated for pH ,osmolality ,assay found to be within  acceptable limits. Finally it can be concluded that the in house product Tafluprost ophthalmic solution was met with in the specification

    The diagnostic utility of cell block as an adjunct to cytological smears

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    Objectives: Cytological examination of serous fluids is of paramount importance in detecting cancer cells. Distinguishing malignant cells from benign reactive mesothelial cells in fluid cytology is an everyday diagnostic problem. Cell blocks are valuable when the features in cytology are inconclusive. The motive of this study was to assess the utility of this method in increasing the diagnostic yield of serous fluids. Methods: 225 (25%) effusion fluids were analyzed carefully by both smear and cell block technique. Results: Among 225 fluids, 139 were pleural, 84 peritoneal and 2 pericardial. In case of pleural fluids and ascitic fluids, maximum numbers of cases were inflammatory. By the cell block technique, 5 additional cases of malignancy in pleural fluids and 7 additional cases of malignancy in ascitic fluids were diagnosed which could not be detected in the cytological smears. In pericardial fluids both cases were inflammatory. Male predominance was noted in case of pleural effusion and female predominance was noted in case of pericardial effusion and ascites. Maximum numbers of cases were seen in the age group of 40-60 years. Conclusion: We conclude that the cell block technique when used as an adjuvant to routine smear examination has increased the diagnostic yield because of better preservation of the architectural pattern

    Correlation between malondialdehyde (MDA) and uric acid levels in preeclampsia

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    Background: Hypertensive disorders of human pregnancy, such as preeclampsia, complicates a sizeable percentage of all pregnancies, need its early indication and warning. The aim of present study was to determine the association between lipid peroxidation product, serum malondialdehyde (MDA) and serum uric acid levels in preeclampsia and find out any association between these two parameters in preeclampsia. Methods: Thirty preeclampsia and thirty gestational age matched normotensive pregnant women attending Narayana General Hospital, Nellore were included in the study. Serum MDA levels were measured by Thiobarbituric acid reactive substances(TBARS) method and serum uric acid levels were estimated by automated chemistry analyser using commercial kits. Results: Serum MDA (Mean±SEM 24.4±2.38 vs 7.9± 0.28 nmol/ml, p value < 0.000) and serum uric acid levels (7.2 ± 0.25 vs 3.9 ± 0.14 mg/dl, p value <0.000) were significantly elevated in preeclampsia cases when compared with that of normotensive pregnant women. A weak positive correlation between serum uric acid and serum MDA (r value 0.065, p value 0.734) was noticed in preeclampsia.Conclusion: Serum MDA and uric acid may be included as additional markers for screening and progression of preeclampsia, thereby helpful in effectively treating the condition at an early stage.

    A FAST AND SENSITIVE SPECTROPHOTOMETRIC METHOD FOR THE DETERMINATION OF HYDRAZINE IN ATAZANAVIR SULFATE DRUG SUBSTANCE

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    Objective: To develop a fast and sensitive UV spectrophotometric method for the quantitative estimation of Hydrazine in Atazanavir Sulfate drug substances and validate as per ICH guidelines. Methods: The method was based upon the observation, that a characteristic colour results upon addition of a solution of p-Dimethylaminobenzaldehyde in ethyl alcohol and hydrochloric acid to hydrazine and estimated at absorbance maximum Â&nbsp;458 nm in Atazanavir drug substance. Results: The developed method resulted in Hydrazine exhibiting linearity in the range 0.2 to 2.7 µg/g. The Intraday and interday precision is exemplified by relative standard deviation of 0.959 % and 0.947%. Percentage Mean recovery was found to be in the range of 97â€101%, during accuracy studies. The limit of detection (LOD) and limit of quantitiation (LOQ) were found to be 0.2 µg/g and 0.6 µg/g respectively. Conclusion: The present work was aimed to develop a visible spectrophotometric method, which is simple, sensitive, accurate and cost effective to evaluate the quality of the bulk and pharmaceutical formulations

    UPLC SEPARATION ANALYSIS OF EMTRICITABINE, TENOFOVIR, COBICISTAT AND ELVITEGRAVIR FROM THEIR DEGRADATION PRODUCTS

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    Objective: A simple, rapid, accurate and precise stability-indicating UPLC analytical method has been developed and validated for the quantitative analysis of Emtricitabine, Tenofovir, Cobicistat and Elvitegravir in bulk drugs and combined dosage forms.Methods: ACE C18 (50 mm x 3 mm, 2µ). The column temperature was maintained at 30oC and run time 8 min. The mobile phase was a mixture of Mobile Phase: A–0.1% TFA in Acetonitrile, B–0.1% TFA in Milli-Q-water. The injection volume of samples was 20μl. UV detection was carried out using a UV-PDA detector at 240 nm. The validation of this method was done as per ICH guidelines.Results: The retention times were observed as 1.46, 3.59, 4.13, 4.64 min for Emtricitabine, Tenofovir disoproxyl fumarate, Cobicistat, and Elvitegravir respectively. Linearity ranges were observed 150-275 µg/ml Emtricitabine, 250-375 µg/ml Tenofovir, 100-225 µg/ml Cobicistat and 100-225 µg/ml Elvitegravir. Relative Standard Deviation did not exceed 2.Conclusion: The newly developed UPLC method for separation of different degradation products along with the pure drugs were found to be capable of giving faster retention times while still maintaining good resolution than that achieved with conventional HPLC. The decreased flow rate 0.4 ml/min, in UPLC indicate more economical. This method exhibited an excellent performance in terms of sensitivity and speed. The results of stress testing undertaken according to the ICH guidelines reveal that the method is specific and stability-indicating. The proposed method has the ability to separate these drugs from their degradation products in tablet dosage forms and hence can be applied to the analysis of routine quality control samples and samples obtained from stability studies.Keywords: Stability indicating assay, RP-UPLC, Emtricitabine, Tenofovir, Cobicistat, Elvitegravir, Forced degradation studie

    Novel 2,5-disubstituted-1,3,4-oxadiazole derivatives induce apoptosis in HepG2 cells through p53 mediated intrinsic pathway

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    AbstractA series of novel 1,3,4-oxadiazole derivatives (OSD, OCOD, ONOD, OPD, COD, PMOD, and PCOD) were synthesized and characterized. Their structures were confirmed on the basis of IR, NMR and mass spectroscopy and molecular weights were found in the range 300–325g/mol. Cancerous cell lines (MCF-7, HepG2) and non-cancerous cell lines (Chang liver cells) were treated with these compounds for 48h, which caused dose dependent decrease in the cell viability. From the seven derivatives, OSD was found to be most potent with IC50 value close to 50μM on all tested cell lines. Hence, this compound was selected for mechanistic study on HepG2 cell lines. Fluorescent cell staining and DNA fragmentation study of 50μM OSD on HepG2 cells, showed events marked by apoptosis such as nuclear fragmentation, cytoplasm shrinkage and DNA damage. Further, the cells with same treatment were quantified for apoptosis using annexin V-PI flow cytometric technique. The percentage of apoptotic cells was significantly higher (p<0.05) after OSD treatment compared to control cells. OSD induced a significant increase (p<0.05) in the expression of the tumor suppressor p53 in HepG2 cells. The constitutive expression of anti-apoptotic protein Bcl-2 significantly decreased (p<0.05) after treatment, while the expression of proapoptotic protein Bax significantly increased (p<0.05). The change in Bax to Bcl-2 ratio suggested involvement of Bcl-2 family in induction of apoptosis. Furthermore, the levels of caspase-9 and caspase-3 were significantly (p<0.05) up regulated in HepG2 cells after OSD treatment. The data suggest that 1,3,4-oxadiazole derivatives induce apoptosis mediated by intrinsic pathway of apoptosis. The findings strengthen the potential of the 1,3,4-oxadiazole scaffold OSD, as an agent with chemotherapeutic and cytostatic activity in human hepatocellular carcinoma in vitro
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