75 research outputs found

    Effect of vitamin D on vascular health in hypertensive patients with vitamin D deficiency

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    Background: Many observational studies have shown association of cardiovascular disease and vitamin D deficiency. However, there is a need for prospective studies to show causal effect of vitamin D and cardiovascular diseases in India. Hence the present study was designed to study the effect of vitamin D on markers of vascular health in hypertensive patients with vitamin D deficiency. The objective of the study was to assess the effect of vitamin D supplementation on markers of vascular health in hypertensive patients with vitamin D deficiency.Methods: Hypertensive patients were screened for vitamin D deficiency defined as 25 OH vitamin D less than 20 ng/mL after written informed consent. Hypertensives deficient with 25 OH vitamin D were recruited for the study to receive cholecalciferol 60000 IU/ week for 8 weeks. The vascular parameters such as blood pressure, pulse wave velocity, arterial stiffness index, malondialdehyde and total antioxidant status were assessed at baseline and after 8 weeks of cholecalciferol. The results were analysed using paired‘t’ test.Results: A total of 119 hypertensive patients were screened for vitamin D status. Among them 57 patients were found to be vitamin D deficient (48.7%). Thirty two patients completed the study. The baseline serum 25 OH vitamin D3 was 12.55 ± 5.7 ng/mL and it increased to 40.06 ± 10.53 ng /mL after 8 weeks.Conclusions: The vascular parameters didn’t show any statistically significant difference between baseline and at 8 weeks. However trend for decline was observed for malondialdehyde, right brachial pulse wave velocity

    Molluscan resources of Kali river estuarine system in Karnataka

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    The present work has shown that there is an organized clam fishery for Meretrix meretrix, Paphia malabarica and Villorita cyprinoides in Kali River. The three species of clams show differential distribution. Paphia malabarica is confined to lower reaches of river from the river mouth to Nandangadda where salinity is 33.44%o suggesting that this species has distinct preference for areas where salinity is high. Meretrix meretrix occurs over a distance of 6.25 km from Nandangadda where the salinity is 30.82%o to Kinnar where the salinity is 8.76%o. Villorita cyprinoids is distributed only in low salinity areas in the upper parts of the river from Botjug to Mallapur where salinity is uniformly low fluctuating between 5.7%o and 0.24%o indicating that this species thrives well in low salinity conditions. During the survey conducted in November- December, 1978 observations were made on the environmental conditions, species composition of the molluscan resources, their distribution pattern, exploitation and marketing and the findings are presented in this paper

    Experimental study of the settlement and collection Of pearl oyster spat from Tuticorin area

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    For the first time settlement and growth of pearl oyst«rs have be-en observed on granite stones forming the embankments of the New Tuticorin Port. Large numbers of pearl oyster spat have also been collected by employing diflfeirent types of spat collectors and the rate of growth of the oysters in the farm has been studied

    Capture the growth kinetics of CVD growth of two-dimensional MoS 2

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    Understanding the microscopic mechanism is fundamental for function-oriented controlled chemical vapor deposition growth of two-dimensional (2D) materials. In this work, we reveal the growth kinetics of 2D MoS2 by capturing the nucleation seeds, evolving morphology, edge structure, and edge terminations at the atomic scale during chemical vapor deposition growth using the transmission electron microscopy and scanning transmission electron microscopy. The direct growth of few-layer and mono-layer MoS2 onto graphene-based transmission electron microscopy grids helped us to perform the subsequent transmission electron microscopy characterization without any solution-based transfer. Two seeding centers are observed: (i) Mo-oxysulfide (MoO x S2−y ) nanoparticles either in multi-shelled fullerene-like structures or as compact nanocrystals for the growth of fewer-layer MoS2; (ii) Mo-S atomic clusters. In the early stage growth, irregular polygons with two primary edge terminations, S-Mo Klein edges and Mo zigzag edges, appear approximately in equal numbers. The morphology evolves into a near-triangle shape in which Mo zigzag edges predominate. Results from density-functional theory calculations are consistent with the inferred growth kinetics, and thus support the growth mechanism we proposed. In general, the growth mechanisms found here should also be applicable in other 2D materials, such as MoSe2, WS2 and WSe2

    Hypoxic-mediated oxidative stress condition and hydroxyapatite-inducing osteogenic differentiation of human mesenchymal stem cells: a mathematical modelling study

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    Avascular necrosis (AVN) of the bones remains a major clinical challenge. Fractures in the talus, the scaphoid, and the neck of the femur are especially challenging to heal due to the low blood vessel network and the lack of collateral blood supply. These fractures are associated with high rates of nonunion and increased infections that require repeated operations. Conventional treatments by autografting or allografting bone replacement and synthetic bone implants have limitations, including the invasiveness of operative procedures, tissue supply insufficiency, and the risk of host rejection. The advancement in tissue engineering has revealed the potential of stem cells as restorative agents for bone injuries. The administration of mesenchymal stem cells (MSCs) into the talus, the scaphoid, and the neck of the femur could produce enhanced osteogenesis via the manipulation of MSC culture conditions. In this study, we used hydroxyapatite as the nanomaterial, and hypoxic milieu to enhance MSC differentiation capacity into the osteogenic lineage, allowing for more rapid and efficient bone cell replacement treatment. Our results demonstrate 1% oxygen and 12.5 μg/mL of hydroxyapatite (HAP) as the optimal conditions to incorporate the osteogenic medium for the osteogenic induction of MSCs. We also established a proof of concept that the addition of HAP and hypoxic conditions could augment the osteoinductive capacity of MSCs. We also developed an accurate mathematical model to support future bone cell replacement therapy

    The 2020 UV emitter roadmap

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    Solid state UV emitters have many advantages over conventional UV sources. The (Al,In,Ga)N material system is best suited to produce LEDs and laser diodes from 400 nm down to 210 nm—due to its large and tuneable direct band gap, n- and p-doping capability up to the largest bandgap material AlN and a growth and fabrication technology compatible with the current visible InGaN-based LED production. However AlGaN based UV-emitters still suffer from numerous challenges compared to their visible counterparts that become most obvious by consideration of their light output power, operation voltage and long term stability. Most of these challenges are related to the large bandgap of the materials. However, the development since the first realization of UV electroluminescence in the 1970s shows that an improvement in understanding and technology allows the performance of UV emitters to be pushed far beyond the current state. One example is the very recent realization of edge emitting laser diodes emitting in the UVC at 271.8 nm and in the UVB spectral range at 298 nm. This roadmap summarizes the current state of the art for the most important aspects of UV emitters, their challenges and provides an outlook for future developments
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