303 research outputs found

    Effects of MHD on Modified Nanofluid Model with Variable Viscosity in a Porous Medium

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    A computational simulation for two-dimensional steady flow of modified nanofluid over an exponential stretching surface in a porous medium with magnet hydrodynamics and variable viscosity is presented in this study. Modified nanofluids are generalization of both hybrid nanofluids and simple nanofluids. Here, we consider three nanoparticles which drastically enhance the thermal conductivity of nanofluid. The viscous model associated with variable viscosity and MHD flow is employed. Well-known similarity transformations are utilized to convert the partial differential equations to system of ordinary differential equations. These converted equations are solved by utilizing the numerical technique Runge–Kutta-Fehlberg method. The impacts of variable viscosity, porosity parameter, Nusselt number, thermal and velocity slip, skin friction coefficient, solid nanoparticle, and magnetic field are observed. The computational results accomplished in the present investigation are validated and felt to be a good agreement with decayed results. It is highlighted that modified nanofluid model enhances the heat transfer rate much higher than the case of hybrid nanofluid and simple nanofluid model

    Down-regulation of DNMT3b in PC3 cells effects locus-specific DNA methylation, and represses cellular growth and migration

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    <p>Abstract</p> <p>Background</p> <p>Aberrations in DNA methylation patterns promote changes in gene expression patterns and are invariably associated with neoplasia. DNA methylation is carried out and maintained by several DNA methyltransferases (DNMTs) among which DNMT1 functions as a maintenance methylase while DNMT3a and 3b serve as de novo enzymes. Although DNMT3b has been shown to preferentially target the methylation of DNA sequences residing in pericentric heterochromatin whether it is involved in gene specific methylation remains an open question. To address this issue, we have silenced the expression of DNMT3b in the prostate-derived PC3 cells through RNA interference and subsequently studied the accompanied cellular changes as well as the expression profiles of selected genes.</p> <p>Results</p> <p>Our results demonstrate that DNMT3b depletion results in increased apoptosis and reduced migration of PC3 cells compared to the untransfected control cells. Reduced DNMT3b expression resulted in hypomethylation of retinoblastoma (Rb), retinoic-acid receptor β (RAR-β), and adenomatous polyposis coli (APC) gene promoters, and also culminated in increased expression of <it>CDKN3 </it>and <it>cytochrome b5</it>. Although DNMT3b silenced cells were found to have reduced growth and migratory potential, there was no apparent changes in their invasive ability compared to the parental PC3 cell line.</p> <p>Conclusion</p> <p>Our findings reveal that DNMT3b preferentially targets certain gene promoters in PC3 cells and that its depletion significantly reduces growth and migration of PC3 cells.</p

    Formulation Optimization and In-vitro Evaluation of Oral Floating Captopril Matrix Tablets using Factorial Design

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    Purpose: To develop a zero-order sustained release floating formulation of captopril, and optimize its drug release for enhanced oral bioavailability.Methods: A relatively new approach, 32 full factorial design, was used to formulate floating captopril matrix tablets and to systematically optimize its drug release using varying levels of xanthan gum and hydroxypropyl methylcellulose (HPMC) K100M polymers. Calcium carbonate was used as gasgenerating agent. After setting the levels by preliminary trials, nine tablet formulations (F1 - F9) were prepared by wet granulation method using Design Expert Software® - suggested combinations of polymers. The concentrations of HPMC K100M (X1) and xanthan gum (X2) were chosen as control variables. Conversely, the response variables selected were timed to release 50 % of the drug (t50%) at 6 h (Q6) and 12 h (Q12). Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) were used to assess compatibility between the drug and the excipients. The validity of the developed mathematical equations was assessed by designing three extra check-points.Results: The response surface plots drawn demonstrated the suitability of the hydrophilic matrixforming agents for formulating controlled release floating tablets of captopril. FTIR and DSC spectra showed no noticeable incompatibility between drug and polymers in both physical mixtures and in formulations. Floating time lag remained &lt; 5.5 min with floating duration &gt; 12 h. Considerable agreement was observed between predicted and actual release parameters. Fitting the data into different kinetic models showed that non-Fickian behavior for diffusion exponent (n) differed from 0.588 and 0.811.Conclusion: Optimum formulation (F4) showed satisfactory release profile. Moreover, the study successfully demonstrated influence of polymer blends in controlling release variables.Keywords: Captopril, Xanthan gum, Hydroxy propyl methyl cellulose , Factorial design, Bioavailabilit

    Promoter hypermethylation of tumor suppressor genes correlates with tumor grade and invasiveness in patients with urothelial bladder cancer

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    Purpose: To investigate the promoter methylation status at selected loci which encode for key proteins involved in apoptosis, DNA repair, cell cycle control and progression in urothelial cell carcinoma of bladder and compare the findings from tissue samples with that of plasma. Methods: Total genomic DNA was isolated from 43 non-muscle invasive (low grade) and 33 muscle invasive (high grade) urothelial bladder cancer samples along with 10 control cases of normal bladder mucosa. Promoter methylation status was investigated for RASSF1A, APC, MGMT, CDKN2A and CDKN2B genes using real-time methylation-specific PCR with SYBR® green. Plasma samples from 16 patients with muscle invasive high grade bladder cancer were also subjected to similar analyses. Results: Promoter hypermethylation was frequently observed in RASSF1A, APC and MGMT gene promoters (p-value \u3c 0.001). The methylation was more prominent in the muscle invasive high grade bladder cancer when compared to non-muscle invasive low grade group (p-value \u3c 0.001) and normal bladder mucosa (p-value \u3c 0.05). The RNA expression of RASSF1A, APC and MGMT was also found to be decreased in the muscle-invasive high grade bladder cancer when compared to the non muscle invasive low grade group (p-value \u3c 0.05). RASSF1A, MGMT and CDKN2A showed comparable results when data from 16 plasma samples was compared to the corresponding tissue samples. Conclusion: Our results suggest that epigenetic silencing of RASSF1A, APC and MGMT genes is strongly associated with invasive high grade urothelial bladder cancer. Thus, status of promoter methylation has the potential to serve as valuable tool for assessing aggressiveness of urothelial cell carcinoma of bladder

    Geoelectrical Survey for the Exploration of Ground Water using Vertical Electrical Sounding: A Case Study of Androt District Rawlakot, Azad Jammu & Kashmir

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    Vertical Electrical Sounding (VES) method has been widely used to depict the subsurface lithology, thickness and structure based on resistivity of layered media with the ultimate objective of evaluating groundwater potential. In this investigation, VES was used to outline subsurface geology to produce a 2D subsurface resistivity model based on the resistivity contrast of layered rocks, for evaluating the accessibility of groundwater in the Siwaliks group of Androt District Rawlakot, Azad Jammu and Kashmir (AJ&amp;K). The Schlumberger electrode configuration was used with spacing arrangement of current electrode (AB/2) going from 1.5 to 250 meters and potential electrode (MN) 1 to 50 meters. The VES data was qualitatively analyzed by using iteration software (IPI2win) which showed that the area is composed of clay, shale, fractured sandstone with intercalation of clay based on resistivity contrast. At depth of 40m-100m along VES indicates good prospects for ground water potential, associated with sandstone beds of Siwaliks group. The resistivity depth section maps at potential depth of 30m, 40m, 60m and 80m are prepared for the demarcation of potential reservoir beds at various depth. The interpreted sounding curves are interpreted qualitatively and pseudo section, Resistivity section and geological log are prepared based on resistivity contrast which shows agreement with geology and hydrological condition of the area. The favorable reservoir rock as an aquifer demarcated in the study area is fractured sandstone with intercalation of clay beds, with apparent resistivity range of 80Ωm to 100Ωm and thickness of 20m to 50m at different sites. The apparent resistivity sections revealed that the North East (NE) and North West (NW) regions are comparatively good potential reservoir for ground water

    Spatial and Temporal Variations of Temperature in the Punjab Province, Pakistan

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    Identifying the temperature change at a regional level is one of the essential parameters to determine the intensity of climate change. The current investigation provides an examination of changing trends of temperature in the Punjab province from 1970 to 2019. Sen's slope estimator method is applied to monthly data of mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) to calculate the rate of temperature change. Statistical methods were used to find out the level of significance in terms of negative or positive trends to examine the variability among various weather observatories. Moreover, predicted values have also been observed for a detailed analysis of temperature variability and trends. Significant and pronounced changes in the mean temperature (T mean) are distinguished all over the Punjab regions with an increasing trend from North to South Punjab. In the case of maximum temperature (Tmax), a faster rate of rising in temperature is observed over the Southern and Western regions of Punjab. In contrast, the minimum temperature (Tmin) shows an increasing trend in Central Punjab. The findings provide detailed insight to policymakers for the planning of mitigating efforts and adaptation strategies in response to climate change

    An Insight into Different Strategies for Control and Prophylaxis of Fasciolosis: A Review

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    Fasciolosis is one of the important diseases of livestock and has zoonotic importance. Fasciolosis can cause huge economic losses due to decrease in milk and meat production, decreased feed conversion ratio, and cost of treatment. Treatment and prophylaxis strategies for Fasciola infection are formed based on epidemiological data. The control of Fasciola infection can be attained by treating the animals with active anthelmintics. The use of different combinations of anthelmintics with a possible rotation is more effective against immature as well as adult flukes. Control of the intermediate host (snail) is vital for the reduction of fasciolosis. Due to the rapid growth of snails, the eradication is quite difficult in waterlogged and marshy areas. The use of different grazing methods and treatment of grazing areas can also help to control fasciolosis. A variety of antigens generated by Fasciola spp. have been shown to protect against liver fluke infection. The crude antigens, excretory/secretory, and refined antigens and their combination can be used as prophylactic treatment for the control of fasciolosis. The use of any of the single or combination of these methods can be very effective for the control of fasciolosis

    Analysis of cervical smears in a muslim population

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    Background: Screening for cancer of the cervix remains a neglected health care issue in Pakistan. To provide baseline data for future efforts to improve screening, we conducted a retrospective analysis of cervical smears taken in the obstetrics and gynaecological clinics of the Aga Khan University Hospital, Karachi, Pakistan.Method: We collected data on cervical smear cytology for cervical smears taken from January 1, 1990 to December 31,1996. We assessed risk factors for dysplasia, including age, age at first marriage, and number of pregnancies.Results: The overall prevalence of abnormal smears in our study was 0.5%. Of 20,995 cervical smears, 12,451 (59.3%) smears showed non-specific inflammation, 7302 (34.8%) were reported as normal, 809 (3.85%) showed monillial infection, 148 (0.71%) showed atypia, 105 (0.5%) had dysplastic cytology, and 52 (0.25%) samples were inadequate. The highest incidence of dysplastic smears was seen in the age group 35 to 44 years. Of 105 patients with dysplasia, 12 were pregnant, and all were asymptomatic, while in 93 non-pregnant women, 33 were symptomatic.Conclusion: The low prevalence of abnormal smears, compared with data from Western populations, could be due to the inherent bias of health awareness in the women who attended our hospital. The results of this study may serve as a baseline for future comparisons. A larger community-based study may establish the exact prevalence of malignant and premalignant lesions so as to plan for future screening

    Connection between the South and East Asian Monsoons: Comparing Summer Monsoon Rainfall of Pakistan and South Korea

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    This study investigates the tele-connection of the southeast Asian monsoon systems by comparing the summer monsoon (June to September) rainfall variability between Pakistan and south Korea. The daily data sets (19812014) of rainfall of Pakistan and south Korea are utilized to explore the possible link. The data products of the National Centers for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR) were also used for the understanding of the large-scale atmospheric environments. The patterns of summer monsoon rainfall on a daily basis between Pakistan and south Korea followed to each other throughout the year. Sub-seasonal differences of the summer monsoon revealed that July is the wettest month in both countries. The large-scale atmospheric environment of higher geopotential height revealed that the Tibetan high and the western north Pacific subtropical high are showing positive anomalies during positive phases over south Asia and east Asia, respectively. The anomalies of zonal wind are negative during positive phase and adverse in the negative phase between 20-40oN. The reduced westerly is interpreted as the seasonal variation and moving of jet streams from the east Asian route. The Tibetan high, northwestern Pacific subtropical high and the east Asian jet stream have reliable and sufficient linkage between the Pakistan and south Korea summer monsoon system
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