69 research outputs found

    Involvement of Src family of kinases and cAMP phosphodiesterase in the luteinizing hormone/chorionic gonadotropin receptor-mediated signaling in the corpus luteum of monkey

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    Background: In higher primates, during non-pregnant cycles, it is indisputable that circulating LH is essential for maintenance of corpus luteum (CL) function. On the other hand, during pregnancy, CL function gets rescued by the LH analogue, chorionic gonadotropin (CG). The molecular mechanisms involved in the control of luteal function during spontaneous luteolysis and rescue processes are not completely understood. Emerging evidence suggests that LH/CGR activation triggers proliferation and transformation of target cells by various signaling molecules as evident from studies demonstrating participation of Src family of tyrosine kinases (SFKs) and MAP kinases in hCG-mediated actions in Leydig cells. Since circulating LH concentration does not vary during luteal regression, it was hypothesized that decreased responsiveness of luteal cells to LH might occur due to changes in LH/CGR expression dynamics, modulation of SFKs or interference with steroid biosynthesis. Methods: Since, maintenance of structure and function of CL is dependent on the presence of functional LH/CGR its expression dynamics as well as mRNA and protein expressions of SFKs were determined throughout the luteal phase. Employing well characterized luteolysis and CL rescue animal models, activities of SFKs, cAMP phosphodiesterase (cAMP-PDE) and expression of SR-B1 (a membrane receptor associated with trafficking of cholesterol ester) were examined. Also, studies were carried out to investigate the mechanisms responsible for decline in progesterone biosynthesis in CL during the latter part of the non-pregnant cycle. Results and discussion: The decreased responsiveness of CL to LH during late luteal phase could not be accounted for by changes in LH/CGR mRNA levels, its transcript variants or protein. Results obtained employing model systems depicting different functional states of CL revealed increased activity of SFKs pSrc (Y-416)] and PDE as well as decreased expression of SR-B1correlating with initiation of spontaneous luteolysis. However, CG, by virtue of its heroic efforts, perhaps by inhibition of SFKs and PDE activation, prevents CL from undergoing regression during pregnancy. Conclusions: The results indicated participation of activated Src and increased activity of cAMP-PDE in the control of luteal function in vivo. That the exogenous hCG treatment caused decreased activation of Src and cAMP-PDE activity with increased circulating progesterone might explain the transient CL rescue that occurs during early pregnancy

    Feasibility of an Alcohol Intervention Programme for TB Patients with Alcohol Use Disorder (AUD) - A Qualitative Study from Chennai, South India

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    The negative influences of alcohol on TB management with regard to delays in seeking care as well as non compliance for treatment has been well documented. This study is part of a larger study on the prevalence of AUD (Alcohol Use Disorder) among TB patients which revealed that almost a quarter of TB patients who consumed alcohol could be classified as those who had AUD. However there is dearth of any effective alcohol intervention programme for TB patients with Alcohol Use Disorder (AUD).This qualitative study using the ecological system model was done to gain insights into the perceived effect of alcohol use on TB treatment and perceived necessity of an intervention programme for TB patients with AUD. We used purposive sampling to select 44 men from 73 TB patients with an AUDIT score >8. Focus group discussions (FGDs) and interviews were conducted with TB patients with AUD, their family members and health providers.TB patients with AUD report excessive alcohol intake as one of the reasons for their vulnerability for TB. Peer pressure has been reported by many as the main reason for alcohol consumption. The influences of alcohol use on TB treatment has been elaborated especially with regard to the fears around the adverse effects of alcohol on TB drugs and the fear of being reprimanded by health providers. The need for alcohol intervention programs was expressed by the TB patients, their families and health providers. Suggestions for the intervention programmes included individual and group sessions, involvement of family members, audiovisual aids and the importance of sensitization by health staff.The findings call for urgent need based interventions which need to be pilot tested with a randomized control trial to bring out a model intervention programme for TB patients with AUD

    Investigating early iron finds from Mayiladumparai Tamil Nadu

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    The paper covers preliminary metallurgical investigations related to the ferrous metal finds excavated at the Iron Age stie of Mayiladumparai by Tamil Nadu State Department of Archaeolog

    Examining queue-jumping phenomenon in heterogeneous traffic stream at signalized intersection using UAV-based data

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    © 2020, Springer-Verlag London Ltd., part of Springer Nature. This research presents an in-depth microscopic analysis of heterogeneous and undisciplined traffic at the signalized intersection. Traffic data extracted from the video recorded using an unmanned aerial vehicle (UAV) at an approach of a signalized intersection is analyzed to study the within green time dynamics of traffic flow. Various parameters of Wiedemann 74, Wiedemann 99, and lateral behavior models used in microscopic traffic simulation package, Vissim, are calibrated for the local heterogeneous traffic. This research is aimed at exploring the queue-jumping phenomenon of motorbikes at signalized intersections and its impact on the saturation flow rate, travel time, and delay. The study of within green time flow dynamics shows that the flow of traffic within green time is not uniform. Surprisingly, the results indicate that the traffic flow for the first few seconds of the green time is significantly higher than the remaining period of green time, which shows a contradiction to the fact that traffic flow for the first few seconds is lower due to accelerating vehicles. Mode-wise traffic counted per second shows that this anomaly is attributed to the presence of motorbikes in front of the queue. Consequently, the outputs of simulation results obtained from calibrated Vissim show that the simulated travel time for motorbikes is significantly lower than the field-observed travel times even though the average simulated traffic flow matches accurately with the field-observed traffic flow. The findings of this research highlight the need to incorporate the queue-jumping behavior of motorbikes in the microsimulation packages to enhance their capability to model heterogeneous and undisciplined traffic

    Involvement of Src family of kinases and cAMP phosphodiesterase in the luteinizing hormone/chorionic gonadotropin receptor-mediated signaling in the corpus luteum of monkey

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    Abstract Background In higher primates, during non-pregnant cycles, it is indisputable that circulating LH is essential for maintenance of corpus luteum (CL) function. On the other hand, during pregnancy, CL function gets rescued by the LH analogue, chorionic gonadotropin (CG). The molecular mechanisms involved in the control of luteal function during spontaneous luteolysis and rescue processes are not completely understood. Emerging evidence suggests that LH/CGR activation triggers proliferation and transformation of target cells by various signaling molecules as evident from studies demonstrating participation of Src family of tyrosine kinases (SFKs) and MAP kinases in hCG-mediated actions in Leydig cells. Since circulating LH concentration does not vary during luteal regression, it was hypothesized that decreased responsiveness of luteal cells to LH might occur due to changes in LH/CGR expression dynamics, modulation of SFKs or interference with steroid biosynthesis. Methods Since, maintenance of structure and function of CL is dependent on the presence of functional LH/CGR its expression dynamics as well as mRNA and protein expressions of SFKs were determined throughout the luteal phase. Employing well characterized luteolysis and CL rescue animal models, activities of SFKs, cAMP phosphodiesterase (cAMP-PDE) and expression of SR-B1 (a membrane receptor associated with trafficking of cholesterol ester) were examined. Also, studies were carried out to investigate the mechanisms responsible for decline in progesterone biosynthesis in CL during the latter part of the non-pregnant cycle. Results and discussion The decreased responsiveness of CL to LH during late luteal phase could not be accounted for by changes in LH/CGR mRNA levels, its transcript variants or protein. Results obtained employing model systems depicting different functional states of CL revealed increased activity of SFKs [pSrc (Y-416)] and PDE as well as decreased expression of SR-B1correlating with initiation of spontaneous luteolysis. However, CG, by virtue of its heroic efforts, perhaps by inhibition of SFKs and PDE activation, prevents CL from undergoing regression during pregnancy. Conclusions The results indicated participation of activated Src and increased activity of cAMP-PDE in the control of luteal function in vivo. That the exogenous hCG treatment caused decreased activation of Src and cAMP-PDE activity with increased circulating progesterone might explain the transient CL rescue that occurs during early pregnancy.</p

    Mathematical analysis of the effects of operating conditions and rheological behaviour of reaction medium on biodiesel synthesis under ultrasound irradiation

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    Ultrasound assisted transesterification has recently been introduced as an effective technology for biodiesel synthesis. However, the behaviour of micro bubbles under ultrasound is affected by operating conditions or rheological properties of reaction mixtures. This paper aims at investigating the changes of micro bubbles characteristics when operating conditions or rheological behaviour of the reaction medium are altered. The mechanistic simulation of micro bubbles was combined with the CFD simulation of reaction mixture to achieve the aims of this work. Continuity and momentum equations of Keller-Miksis model were employed along with reaction, mass and energy balances to simulate different characteristics of micro bubbles such as temperature, pressure, oscillation velocity, maximum radius of micro bubble, equilibrium state of bubble content, diffusion rates of reaction compounds towards bubbles and reaction within bubbles. It was found that among different combinations of reaction temperature, reactants ratio and intensity of ultrasound irradiation, the last one played the most important role. Radius, internal temperature and pressure of bubbles significantly increased with power amplitude due to stronger expansion and greater energy accumulation. At the same time, increase in reaction temperature and alcohol concentration made the bubbles characteristics rather moderate. It was also found that the growth of bubbles radius was reduced by about 4 times as the reaction progressed and the reaction mixture became more viscous and dense. The maximum internal temperature and pressure decreased by about 178 K and 220 bar due to moderate expansion of bubbles. Oscillation velocity was also restricted in this situation

    Electrical energy per order determination for the removal pollutant from industrial wastewater using UV/Fe 2+ /H 2 O 2 process: Optimization by response surface methodology

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    Comparison of UV, H2O2, Fe2+, UV/H2O2, UV/Fe2+, Fe2+/H2O2 and UV/Fe2+/H2O2 processes for the removal of percentage color, COD and electrical energy per order from the effluent distillery industry. The results showed that, UV/Fe2+/H2O2 process yield higher percentage color and COD removal with low electrical energy per order than UV, UV/H2O2, UV/Fe2+ process. To obtain the UV/Fe2+/H2O2 process performance by operating various parameters on the percentage color and COD removal using response surface methodology. A Regression quadratic model describing the percentage color and COD removal efficiency of UV/Fe2+/H2O2 process were developed and validate by analysis of variance. Experimental results showed that, UV/Fe2+/H2O2 process can effectively reduced 96.50% of color and 84.40% of COD removal of the distillery industry wastewater under the optimum conditions such as Fe2+-1.50 mM, H2O2-200 mM, COD-1500 ppm and pH-3.2, respectively. Result concluded that, UV/Fe2+/H2O2 process can be used effectively for the treatment of real industrial effluent

    Investigation of mass transfer intensification under power ultrasound irradiation using 3D computational simulation: A comparative analysis

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    This paper aims at investigating the influence of acoustic streaming induced by low-frequency (24 kHz) ultrasound irradiation on mass transfer in a two-phase system. The main objective is to discuss the possible mass transfer improvements under ultrasound irradiation. Three analyses were conducted: i) experimental analysis of mass transfer under ultrasound irradiation; ii) comparative analysis between the results of the ultrasound assisted mass transfer with that obtained from mechanically stirring; and iii) computational analysis of the systems using 3D CFD simulation. In the experimental part, the interactive effects of liquid rheological properties, ultrasound power and superficial gas velocity on mass transfer were investigated in two different sonicators. The results were then compared with that of mechanical stirring. In the computational part, the results were illustrated as a function of acoustic streaming behaviour, fluid flow pattern, gas/liquid volume fraction and turbulence in the two-phase system and finally the mass transfer coefficient was specified. It was found that additional turbulence created by ultrasound played the most important role on intensifying the mass transfer phenomena compared to that in stirred vessel. Furthermore, long residence time which depends on geometrical parameters is another key for mass transfer. The results obtained in the present study would help researchers understand the role of ultrasound as an energy source and acoustic streaming as one of the most important of ultrasound waves on intensifying gas-liquid mass transfer in a two-phase system and can be a breakthrough in the design procedure as no similar studies were found in the existing literature
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