30 research outputs found

    Characterization of foam flow in pipes using two flow regime concept

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    The objective of this study is to investigate the characteristics of foam flow behavior in pipes in a wide range of experimental conditions, including two pipe materials (stainless steel and nylon pipes with about 0.36 - 0.38 inch in inner diameter and 12 ft in length), three surfactant formulations (Cedepal FA-406, Stepanform-1050, and Aquet-944), and three surfactant concentrations (0.1, 0.5, and 5 wt%). The concept of “two foam-flow regimes”, consisting of high-quality regime and low-quality regime, is at the heart of interpreting the experimental data. The experimental results in horizontal pipes showed the presence of two distinct high-quality and low-quality foam-flow regimes which could be identified by both pressure responses and direct visual observations. The high-quality regime was characterized by unstable and oscillating pressure responses represented by slug flow, while the low-quality regime was characterized by stable pressure responses represented by either plug flow or segregated flow. These two distinct flow regimes, separated by a locus of fg* in the contour plot, were shown to have different sensitivities to the change in gas and liquid velocities: (1) foam rheology in the high-quality regime was sensitive to both gas and liquid velocities because of the resulting changes in lengths of foam-slug and free-gas sections adjusted to the new flow conditions, and (2) foam rheology in the low-quality regime was sensitive to gas velocity because of finer foam texture at higher shear rates, and was relatively insensitive to liquid velocity because of lubricating effect and drainage effect. The results at different inclination angles showed that foam rheology was not significantly altered by the inclination angle as long as the slug-flow or plug-flow pattern was formed because of a viscous-force dominant environment. However, if flow conditions fell within the segregated-flow pattern, foam rheology was governed by the gravitational force rather than the viscous force, and therefore the flow characteristics were sensitive to inclination angles. These findings were supported by visual observations as well as pressure responses. The implication of these experimental findings is discussed for applications such as foam-assisted underbalanced drilling processes and foam-fracturing treatments in the petroleum industry

    Developing linkages for agricultural technology transfer: A case study of research institution and voluntary organization partnership

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    A paradigm shift to the private and voluntary organizations led extension is being witnessed as the public agricultural extension system has been adversely affected by various constraints. ICAR-Indian Agricultural Research Institute (IARI) a premier agricultural research institution took lead to develop linkages with voluntary organizations (VOs) of repute for speedy transfer of agricultural technologies to the ultimate users. The present study was conducted on randomly selected 120 farmers of Patiala district to analyze the effectiveness of IARI linkage with VO namely Young Farmers' Association (YFA) of Punjab state. The advisory services through IARI-YFA linkage, higher yield of IARI released varieties, social participation of farmers and their education were the major determinants for the adoption of IARI varieties. In case of both rice and wheat, IARI varieties were sown in more than 60% area of the total land holdings of the farmers. Although, the linkage was perceived highly effective in terms of the delivery of farm technologies, advisory services, farm literature supplied, farmers' fair, front line demonstrations, impact on yield and income of farmers and satisfaction of farmers but non-availability of seeds in desired quantity, higher seed cost and less land for seed multiplication were major inhibiting factors. The functional efficacy of linkage may be enhanced through close collaboration of state level government and private agencies for broad based, inclusive and sustainable agricultural development

    Preterm birth among pregnancies conceived by assisted reproduction techniques in Mumbai, Maharashtra, India

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    Background: Preterm births are an enormous global problem on families, medical system and economy. The rates of preterm birth are increasing and one of the contributors is growing use of Assisted Reproduction Techniques (ART) leading to multifetal gestations. Some risk factors for preterm birth are specific to women who conceive by ART. Since there is limited data from India, this pilot study was undertaken to assess the magnitude of preterm birth among pregnancies conceived by ART and to study the contributing factors.Methods: Clinic based descriptive cohort study through eight ART clinics in Mumbai for one year. Data was collected using an in-depth questionnaire on socio-demographic characteristics, medical history, ART details, course and complications during pregnancy, mode of delivery, pregnancy outcome, risk factors related to preterm birth and neonatal outcome. Complete details of 113 participants who completed the study were analyzed.Results: Study showed high incidence of preterm birth (76.23%) among women conceived with ART. Multiple gestations were observed in 45.1%. Pregnancy related complications like heterotrophic pregnancy (3%), pre eclampsia (15%) and gestational diabetes (11%) were high. Incidence of caesarean section was very high (98%). Neonatal outcome was good with 98% live births and only 2 still births.Conclusions: Present study highlights that preterm birth, multiple pregnancies, pregnancy related complications like preeclampsia, gestational diabetes and caesarean sections are very high among women conceived by ART. With growing use of ART there is an urgent need to develop a National ART Surveillance system in India like the one in Centre for Disease Control Atlanta to get complete data on the pregnancy course and outcomes of ART conceptions. Efforts to limit the number of embryos transferred should be strengthened to prevent multiple births

    Surfactant protein D inhibits HIV-1 infection of target cells via interference with gp120-CD4 interaction and modulates pro-inflammatory cytokine production

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    © 2014 Pandit et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Surfactant Protein SP-D, a member of the collectin family, is a pattern recognition protein, secreted by mucosal epithelial cells and has an important role in innate immunity against various pathogens. In this study, we confirm that native human SP-D and a recombinant fragment of human SP-D (rhSP-D) bind to gp120 of HIV-1 and significantly inhibit viral replication in vitro in a calcium and dose-dependent manner. We show, for the first time, that SP-D and rhSP-D act as potent inhibitors of HIV-1 entry in to target cells and block the interaction between CD4 and gp120 in a dose-dependent manner. The rhSP-D-mediated inhibition of viral replication was examined using three clinical isolates of HIV-1 and three target cells: Jurkat T cells, U937 monocytic cells and PBMCs. HIV-1 induced cytokine storm in the three target cells was significantly suppressed by rhSP-D. Phosphorylation of key kinases p38, Erk1/2 and AKT, which contribute to HIV-1 induced immune activation, was significantly reduced in vitro in the presence of rhSP-D. Notably, anti-HIV-1 activity of rhSP-D was retained in the presence of biological fluids such as cervico-vaginal lavage and seminal plasma. Our study illustrates the multi-faceted role of human SPD against HIV-1 and potential of rhSP-D for immunotherapy to inhibit viral entry and immune activation in acute HIV infection. © 2014 Pandit et al.The work (Project no. 2011-16850) was supported by Medical Innovation Fund of Indian Council of Medical Research, New Delhi, India (www.icmr.nic.in/)

    Complex genetics of female fertility

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    Variation in reproductive lifespan and female fertility have implications for health, population size and ageing. Fertility declines well before general signs of menopause and is also adversely affected by common reproductive diseases, including polycystic ovarian syndrome (PCOS) and endometriosis. Understanding the factors that regulate the timing of puberty and menopause, and the relationships with fertility are important for individuals and for policy. Substantial genetic variation exists for common traits associated with reproductive lifespan and for common diseases influencing female fertility. Genetic studies have identified mutations in genes contributing to disorders of reproduction, and in the last ten years, genome-wide association studies (GWAS) have transformed our understanding of common genetic contributions to these complex traits and diseases. These studies have made great progress towards understanding the genetic factors contributing to variation in traits and diseases influencing female fertility. The data emerging from GWAS demonstrate the utility of genetics to explain epidemiological observations, revealing shared biological pathways linking puberty timing, fertility, reproductive ageing and health outcomes. Many variants implicate DNA damage/repair genes in variation in the age at menopause with implications for follicle health and ageing. In addition to the discovery of individual genes and pathways, the increasingly powerful studies on common genetic risk factors help interpret the underlying relationships and direction of causation in the regulation of reproductive lifespan, fertility and related traits

    Glucose Regulated Protein 78 Phosphorylation in Sperm Undergoes Dynamic Changes during Maturation

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    <div><p>GRP78, a resident endoplasmic reticulum (ER) chaperone involved in protein transport, folding and assembly, has been reported in sperm. It is shown to be localized in the neck region of human sperm. We have previously reported GRP78 to be less phosphorylated in asthenozoosperm.The present study aimed to determine whether sperm GRP78 undergoes phosphorylation changes during epididymal maturation and whether there are any differences in GRP78 phosphoforms in asthenozoosperm vis-à-vis normozoosperm. Testicular- and cauda epididymal- sperm from adult male Holtzman rats, and semen ejaculates collected from normal and asthenozoospermic individuals were investigated. DIGE carried out to determine phosphorylation of GRP78 in asthenozoosperm and normal sperm reveals a shift in the location of GRP78 of asthenozoosperm towards the alkaline pH, indicative of reduced GRP78 phosphorylation. Immunoprecipitation studies using antibodies specific to GRP78, serine-, threonine-, and tyrosine phosphorylation and Pan phospho antibody demonstrates GRP78 to be phosphorylated at all three residues in rat spermatozoa. Phosphatase assays using Calf intestinal alkaline phosphatase and Lambda protein phosphatase followed by nanofluidic proteomic immunoassay (NIA) show that in rat, GP<sub>4.96</sub>, GP<sub>4.94</sub> and GP<sub>4.85</sub> are the three phosphoforms in mature (caudal) sperm as against two phosphoforms GP<sub>4.96</sub>and GP<sub>4.94</sub>in immature (testicular) sperm. In mature human sperm GP<sub>5.04</sub>, GP<sub>4.96</sub>, and GP<sub>4.94</sub>were the 3 phosphoforms observed. GP<sub>4.94</sub>[P = 0.014]andGP<sub>5.04</sub> [P = 0.02] are significantly reduced in asthenozoosperm. Ours is the first report indicating GRP78 in sperm to be phosphorylated at serine, threonine and tyrosine residues contrary to published literature reporting GRP78 not to be tyrosine phosphorylated. We report the presence of GRP78 phosphoforms in rat- and human- sperm and our data suggest that GRP78 phosphorylation in sperm undergoes spatial reorganization during epididymal maturation. Significant differences observed in 2 out of 3 phosphoforms in asthenozoosperm suggest that GRP78 phosphorylation may have functional relevance in sperm with consequent clinical implications.</p></div

    Multipleforms of GRP78 in Human sperm by NIA.

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    <p>Representative isoelectropherograms of NIA profile for GRP78 in normal sperm <b>(A)</b> and asthenozoosperm <b>(B)</b>. Four peaks GP<sub>4.94</sub>, GP<sub>4.96</sub><sup>,</sup> GP<sub>5.04</sub> and GP<sub>5.43</sub> are consistently observed. Bar diagram of the cumulative data comparing GRP78 profile of Asthenozoosperm with that of Normozoosperm is shown <b>(C)</b>. Experiments were performed in 3 biological replicates for each group with 3 technical replicates for each. Values expressed are mean ± Standard Deviation (SD). Statistical significance was determined using Unpaired Students’ ‘t’ test with significance level set at P ≤ 0.05. ‘GP’ represents the GRP78 Peak and the value in the subscript indicates the pI of the respective peak.</p

    Effect of drill pipe orbital motion on non-Newtonian fluid flow in an eccentric wellbore: a study with computational fluid dynamics

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    10.1007/s13202-021-01403-yJournal of Petroleum Exploration and Production Technolog

    Cystic fibrosis transmembrane conductance regulator (CFTR) gene abnormalities in Indian males with congenital bilateral absence of vas deferens & renal anomalies

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    Background & objectives: The role of cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in congenital bilateral absence of vas deferens and unilateral renal agenesis (CBAVD-URA) has been controversial. Here, we report the cases of five Indian males with CBAVD-URA. The objective was to evaluate the presence or absence of CFTR gene mutations and variants in CBAVD-URA. The female partners of these males were also screened for cystic fibrosis (CF) carrier status. Methods: Direct DNA sequencing of CFTR gene was carried out in five Indian infertile males having CBAVD-URA. Female partners (n=5) and healthy controls (n=32) were also screened. Results: Three potential regulatory CFTR gene variants (c.1540A>G, c.2694T>G and c.4521G>A) were detected along with IVS8-5T mutation in three infertile males with CBAVD-URA. Five novel CFTR gene variants (c.621+91A>G, c.2752+106A>T, c.2751+85_88delTA, c.3120+529InsC and c.4375-69C>T), four potential regulatory CFTR gene variants (M470V, T854T, P1290P, Q1463Q) and seven previously reported CFTR gene variants (c.196+12T>C, c.875+40A>G, c.3041-71G>C, c.3271+42A>T, c.3272-93T>C, c.3500-140A>C and c.3601-65C>A) were detected in infertile men having CBAVD and renal anomalies Interpretation & conclusions: Based on our findings, we speculate that CBAVD-URA may also be attributed to CFTR gene mutations and can be considered as CFTR-related disorder (CFTR-RD). The CFTR gene mutation screening may be offered to CBAVD-URA men and their female partners undergoing ICSI. Further studies need to be done in a large sample to confirm the findings
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