OBTAINING TEMPERATURE FIELDS AS A FUNCTION OF EFFICIENCY IN TIG WELDING BY NUMERICAL MODELING

The temperature field serves as the basis for predicting levels of residual stress in a welded joint. The aspects related to the mathematical modeling of complex welding procedures were pondered with the FEM: variations in the physical and mechanical properties of the materials as a function of the temperature, the transience and the speed of the welding process, the material phase transformations, the different mechanisms of heat exchange with the environment (convection and radiation), all them associated with a high level of nonlinearity. The heat source used in this analytical model for heat supply was the double ellipsoid model proposed by Goldak (2005), in which a 60 mm x 50 mm and 3 mm rectangular ASTM AH36 steel plate was used for the TIG process simulations. It was made a comparison of temperature fields for three different values of process efficiency (60%, 70% and 80%). The results showed many differences in the temperature fields following changes in the levels of residual stresses which will be determined in further studies

Pregnancy outcome in patients with fibroid: a retrospective study

Background: Fibroids are benign smooth muscle cell tumour of the uterus. In some patients of pregnancy associated with fibroid, it does not affect the outcome of pregnancy. On the other hand, various complications have been reported. The aim of our study was to evaluate the outcome in antenatal women with fibroids.Methods: This retrospective study was conducted at tertiary care center, obstetrics & gynecology department over a period of eighteen months between June 2018 to November 2019. Total 26 pregnant patients with >3 cm fibroid was included in the study. They were followed during antenatal period. Maternal age, parity, size of fibroid, complications during pregnancy, labour, and delivery, mode of delivery and indications of cesarean section were noted.Results: Out of 26 patients, 15 (57.6%) were between 26-30 years of age group and 16 (61.53%) were multigravidas. Normal vaginal delivery occurred in 8 (33.33%), while 16 (66.66%) delivered by caesarean section. There were 9 (34.61%) patients who had no complication whereas 17 (65.38%) had some complication. Pain was present in 8 (30.76%). PROM and preterm labour were present in 3 (18.75%) and 5 (19.23%) respectively. PPH was present in 2 (7.69%).Conclusions: Pregnant patients who have fibroids are to be carefully screened in the antenatal period, so as to have a regular follow up. The widespread use of ultrasonography has facilitated diagnosis and management of fibroids in pregnancy. The site and size of fibroid is very important to predict its effect on pregnancy

Doubling maize (Zea mays) production of India by 2025 – Challenges and opportunities

Maize (Zea mays L.) is a commodity of high economic significance in India. Its demand and production is increasing more rapidly as compared to other major commodities. It is estimated that by 2025, India would require 50 million metric tonnes (MMT) maize grain, of which 32 MMT would be required in the feed sector, 15 MMT in the industrial sector, 2 MMT as food, and 1 MMT for seed and miscellaneous purposes. Over this, there would be about 10 MMT of export potential also. Thus, in the next 10 years there is a necessity and opportunity for doubling India's maize production from the current level of approximately 25 MMT. Prevalence of yield limiting biotic and abiotic stresses, lower adoption of modern production technologies in certain regions, extension and policy gaps, etc. remain major challenges before the Indian maize sector. Therefore, strong technological and policy interventions would be required to achieve the goal of doubling maize production. By 2025, productivity level of 5-6 tonnes/ha need to be targeted, in order to double the production without significant increase in acreage. Technological interventions like cultivar development and diversification, incorporation of stress resilience in the germplasm, accelerating the breeding process through new tools, and adoption of modern cultivation and protection practices including conservation agriculture technologies would play a key role in increasing the productivity. At the same time, policy interventions like strengthening of post-harvest handling infrastructure, price stabilization mechanisms, and value chains, streamlining of extension system, augmenting hybrid seed delivery mechanisms, appropriate policy on genetically modified seeds etc. will be essentially required

OBTAINING TEMPERATURE FIELDS AS A FUNCTION OF EFFICIENCY IN TIG WELDING BY NUMERICAL MODELING

ABSTRACT The temperature field serves as the basis for predicting levels of residual stress in a welded joint. The aspects related to the mathematical modeling of complex welding procedures were pondered with the FEM: variations in the physical and mechanical properties of the materials as a function of the temperature, the transience and the speed of the welding process, the material phase transformations, the different mechanisms of heat exchange with the environment (convection and radiation), all them associated with a high level of nonlinearity. The heat source used in this analytical model for heat supply was the double ellipsoid model proposed b

An analysis of interspecific hybrids and phylogenetic implications in Cucumis (Cucurbitaceae)

Investigations on interspecific crossability in 8Cucumis species (2n = 24) and chromosome pairing and pollen fertility of their hybrids from 15 combinations have been utilized for tracing the phylogenetic relationships among these taxa and factors responsible for their differentiation. A collective evaluation of data suggests that there are three broad groups of species, one of the spiny fruited interfertile species, whose hybrids show varying degree of chromosome associations and low to high pollen fertility; the second of species with non-spiny fruits, which are completely incompatible with the former but weakly compatible with the cultivated species,C. melo L. to produce partly developed seeds, and the third group ofC. metuliferusE. Mey. exSchrad. andC. melo and its different botanical varieties. The species with spiny fruits can be further divided based on karyomorphological similarities and/or on relative genomic affinity, indicated by chromosome pairing and hybrid pollen fertility

The Putative Drp1 Inhibitor mdivi-1 Is a Reversible Mitochondrial Complex I Inhibitor that Modulates Reactive Oxygen Species

Mitochondrial fission mediated by the GTPase dynamin-related protein 1 (Drp1) is an attractive drug target in numerous maladies that range from heart disease to neurodegenerative disorders. The compound mdivi-1 is widely reported to inhibit Drp1-dependent fission, elongate mitochondria, and mitigate brain injury. Here, we show that mdivi-1 reversibly inhibits mitochondrial complex I-dependent O2 consumption and reverse electron transfer-mediated reactive oxygen species (ROS) production at concentrations (e.g., 50 μM) used to target mitochondrial fission. Respiratory inhibition is rescued by bypassing complex I using yeast NADH dehydrogenase Ndi1. Unexpectedly, respiratory impairment by mdivi-1 occurs without mitochondrial elongation, is not mimicked by Drp1 deletion, and is observed in Drp1-deficient fibroblasts. In addition, mdivi-1 poorly inhibits recombinant Drp1 GTPase activity (Ki > 1.2 mM). Overall, these results suggest that mdivi-1 is not a specific Drp1 inhibitor. The ability of mdivi-1 to reversibly inhibit complex I and modify mitochondrial ROS production may contribute to effects observed in disease models. © 2017 Elsevier Inc

Genetic modification of human mesenchymal stem cells helps to reduce adiposity and improve glucose tolerance in an obese diabetic mouse model

INTRODUCTION: Human mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into fat, muscle, bone and cartilage cells. Exposure of subcutaneous abdominal adipose tissue derived AD-MSCs to high glucose (HG) leads to superoxide accumulation and up-regulation of inflammatory molecules. Our aim was to inquire how HG exposure affects MSCs differentiation and whether the mechanism is reversible. METHODS: We exposed human adipose tissue derived MSCs to HG (25 mM) and compared it to normal glucose (NG, 5.5 mM) exposed cells at 7, 10 and 14 days. We examined mitochondrial superoxide accumulation (Mitosox-Red), cellular oxygen consumption rate (OCR, Seahorse) and gene expression. RESULTS: HG increased reactive superoxide (ROS) accumulation noted by day 7 both in cytosol and mitochondria. The OCR between the NG and HG exposed groups however did not change until 10 days at which point OCR of HG exposed cells were reduced significantly. We noted that HG exposure upregulated mRNA expression of adipogenic (PPARG, FABP-4, CREBP alpha and beta), inflammatory (IL-6 and TNF alpha) and antioxidant (SOD2 and Catalase) genes. Next, we used AdSOD2 to upregulate SOD2 prior to HG exposure and thereby noted reduction in superoxide generation. SOD2 upregulation helped reduce mRNA over-expression of PPARG, FABP-4, IL-6 and TNFα. In a series of separate experiments, we delivered the eGFP and SOD2 upregulated MSCs (5 days post ex-vivo transduction) and saline intra-peritoneally (IP) to obese diabetic (db/db) mice. We confirmed homing-in of eGFP labeled MSCs, delivered IP, to different inflamed fat pockets, particularly omental fat. Mice receiving SOD2-MSCs showed progressive reduction in body weight and improved glucose tolerance (GTT) at 4 weeks, post MSCs transplantation compared to the GFP-MSC group (control). CONCLUSIONS: High glucose evokes superoxide generation, OCR reduction and adipogenic differentiation. Mitochondrial superoxide dismutase upregulation quenches excess superoxide and reduces adipocyte inflammation. Delivery of superoxide dismutase (SOD2) using MSCs as a gene delivery vehicle reduces inflammation and improves glucose tolerance in vivo. Suppression of superoxide production and adipocyte inflammation using mitochondrial superoxide dismutase may be a novel and safe therapeutic tool to combat hyperglycemia mediated effects

N- and C-Terminal Domains of the Calcium Binding Protein EhCaBP1 of the Parasite Entamoeba histolytica Display Distinct Functions

Entamoeba histolytica, a protozoan parasite, is the causative agent of amoebiasis, and calcium signaling is thought to be involved in amoebic pathogenesis. EhCaBP1, a Ca2+ binding protein of E. histolytica, is essential for parasite growth. High resolution crystal structure of EhCaBP1 suggested an unusual arrangement of the EF-hand domains in the N-terminal part of the structure, while C-terminal part of the protein was not traced. The structure revealed a trimer with amino terminal domains of the three molecules interacting in a head-to-tail manner forming an assembled domain at the interface with EF1 and EF2 motifs of different molecules coming close to each other. In order to understand the specific roles of the two domains of EhCaBP1, the molecule was divided into two halves, and each half was separately expressed. The domains were characterized with respect to their structure, as well as specific functional features, such as ability to activate kinase and bind actin. The domains were also expressed in E. histolytica cells along with green fluorescent protein. The results suggest that the N-terminal domain retains some of the properties, such as localization in phagocytic cups and activation of kinase. Crystal structure of EhCaBP1 with Phenylalanine revealed that the assembled domains, which are similar to Calmodulin N-terminal domain, bind to Phenylalanine revealing the binding mode to the target proteins. The C-terminal domain did not show any of the activities tested. However, over-expression in amebic cells led to a dominant negative phenotype. The results suggest that the two domains of EhCaBP1 are functionally and structurally different from each other. Both the domains are required for structural stability and full range of functional diversity