187 research outputs found

    Cells and Organs on Chip—A Revolutionary Platform for Biomedicine

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    Lab‐on‐a‐chip (LOC) and microfluidics are important technologies with numerous applications from drug delivery to tissue engineering. LOC integrates fluidic and electronic components on a single chip and becomes very attractive due to the possibility of their state‐of‐art implementation in personalized devices for the point‐of‐care treatments. Microfluidics is the technique that deals with small (10-9 to 10-18 L) amounts of fluids, using channels with dimensions of 10 to 100 ÎŒm. These LOC and microfluidics devices enable the development of next‐generation portable and implantable bioelectronics devices. Superior chip‐based technologies are emerging with the advances in microfluidics and motivating various chip‐based methods for rapid low‐cost analysis as compared to traditional laboratory method.An organ‐on‐chip (OOC) is on‐chip cell culture device created with microfabrication techniques and contains continuously perfused chambers inhabited by living cells that simulate tissue‐ and organ‐level physiology. In vitro models of cells, tissues and organ based on LOC devices are a major breakthrough for research in biologic systems and mechanisms. The recapitulations of cellular events in OOC devices provide them an edge over two‐dimensional (2D) and three‐dimensional (3D) cultures and open a gateway for their newer applications in biomedicine such as tissue engineering, drug discovery and disease modeling. In this chapter, the advancement and potential applications of OOC devices are discussed

    Thermal and Transport Behavior of Single Crystalline R2CoGa8 (R = Gd, Tb, Dy, Ho, Er, Tm, Lu and Y) Compounds

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    The anisotropy in electrical transport and thermal behavior of single crystalline R2_{2}CoGa8_{8} series of compounds is presented. These compounds crystallize in a tetragonal structure with space gropup P4/mmm. The nonmagnetic counterparts of the series namely Y2_{2}CoGa8_{8} and Lu2_{2}CoGa8_{8}show a behavior consistent with the low density of states at the fermi level. In Y2_{2}CoGa8_{8}, a possibility of charge density wave transition is observed at ≈\approx 30 K. Gd2_{2}CoGa8_{8} and Er2_{2}CoGa8_{8} show a presence of short range correlation above the magnetic ordering temperature of the compound. In case of Gd2_{2}CoGa8_{8}, the magnetoresistance exhibits a significant anisotropy for current parallel to {[}100{]} and {[}001{]} directions. Compounds with other magnetic rare earths (R = Tb, Dy, Ho and Tm) show the normal expected magnetic behavior whereas Dy2_{2}CoGa8_{8} exhibits the possibility of charge density wave (CDW) transition at approximately same temperature as that of Y2_{2}CoGa8_{8}. The thermal property of these compounds is analysed on the basis of crystalline electric field (CEF) calculations.Comment: 10 Pages 14 Figures. Submitted to PR

    Graphene Quantum Dots - From Emergence to Nanotheranostic Applications

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    Quantum dots are at the cutting edge of nanotechnology development. Due to their unique optical and physical properties, they have potential applications in many avenues of medicine and biotechnology. With the advancements in nano-sciences, novel applications of quantum dots are constantly being explored for drug delivery and bioimaging. Graphene quantum dots (GQDs) are nanoparticles of graphene with properties of quantum dots as well as graphene. GQDs have ignited remarkable research interest in the field of medicine and biology and are considered as well-suited candidates for nanotheranostic applications due to their excellent biocompatibility and tunable physicochemical properties. The promising emerging implications of GQD platforms for diagnostics and therapeutics advances are the basis of this chapter

    Magnetocrystalline anisotropy in RAu_{2}Ge_{2} (R = La, Ce and Pr) single crystals

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    Anisotropic magnetic properties of single crystalline RAu_{2}Ge_{2} (R = La, Ce and Pr) compounds are reported. LaAu_{2}Ge_{2} exhibit a Pauli-paramagnetic behavior whereas CeAu_{2}Ge_{2} and PrAu_{2}Ge_{2} show an antiferromagnetic ordering with N\grave{e}el temperatures T_{N} = 13.5 and 9 K, respectively. The anisotropic magnetic response of Ce and Pr compounds establishes [001] as the easy axis of magnetization and a sharp spin-flip type metamagnetic transition is observed in the magnetic isotherms. The resistance and magnetoresistance behavior of these compounds, in particular LaAu_{2}Ge_{2}, indicate an anisotropic Fermi surface. The magnetoresistivity of CeAu_{2}Ge_{2} apparently reveals the presence of a residual Kondo interaction. A crystal electric field analysis of the anisotropic susceptibility in conjunction with the experimentally inferred Schottky heat capacity enables us to propose a crystal electric field level scheme for Ce and Pr compounds. For CeAu_{2}Ge_{2} our values are in excellent agreement with the previous reports on neutron diffraction. The heat capacity data in LaAu_{2}Ge_{2} show clearly the existence of Einstein contribution to the heat capacity.Comment: Submitted to PRB 11 Pages 13 Figure

    Predicting the impact of climate change on range and genetic diversity patterns of the endangered endemic Nilgiri tahr (Nilgiritragus hylocrius) in the western Ghats, India

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    [Context] Climate change is considered an important factor affecting the distribution and genetic diversity of species. While many studies have described the influence of climate change on population structure at various scales, little is known about the genetic consequences of a changing climate on endemic species.[Objectives] To assess possible changes in the distribution and genetic structure of the endangered Nilgiri tahr (Nilgiritragus hylocrius), which is endemic to the Western Ghats in India, under climate change and human disturbances.[Methods] We integrated tahr occurrence and nuclear DNA data with environmental geo-datasets to project the response of tahr populations to future climate change with respect to its distribution, genetic diversity and population structure. We screened the environmental variables using MaxEnt to identify a manageable set of predictors to be used in an ensemble approach, based on ten species distribution modelling techniques, to quantify the current tahr distribution. We then projected the distribution and genetic structure under two climate change scenarios.[Results] We found that suitable habitat for tahr (9,605 km2) is determined predominantly by a combination of climatic, human disturbance and topographic factors that result in a highly fragmented habitat throughout its distribution range in the Western Ghats. Under the severe high emissions RCP8.5 scenario tahr populations may lose more than half of their available habitat (55.5%) by 2070. Application of spatial Bayesian clustering suggests that their current genetic structure comprise four genetic clusters, with three of them reflecting a clear geographic structure. However, under climate change, two of these clusters may be lost, and in the future a homogenization of the genetic background of the remaining populations may arise due to prevalence of one gene pool cluster in the remaining populations.[Conclusions] Our interdisciplinary approach that combines niche modelling and genetic data identified the climate refugia (i.e., the remaining stable habitats that overlap with the current suitable areas), where the tahr populations would be restricted to small, isolated and fragmented areas. Essential factors to avert local extinctions of vulnerable tahr populations are a reduction of human disturbances, dispersal of tahr between fragmented populations, and the availability of corridors.This research was supported by the Department of Biotechnology, Ministry of Science and Technology, Government of India, and by a German Research Foundation (DFG) fellowship awarded to RK (project number 273837911).Peer reviewe

    Management of chronic obstructive pulmonary disease in India: a systematic review.

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    OBJECTIVES: Chronic diseases are fast becoming the largest health burden in India. Despite this, their management in India has not been well studied. We aimed to systematically review the nature and efficacy of current management strategies for chronic obstructive pulmonary disease (COPD) in India. METHODS: We used database searches (MEDLINE, EMBASE, IndMED, CENTRAL and CINAHL), journal hand-searches, scanning of reference lists and contact with experts to identify studies for systematic review. We did not review management strategies aimed at chronic diseases more generally, nor management of acute exacerbations. Due to the heterogeneity of reviewed studies, meta-analysis was not appropriate. Thus, narrative methods were used. SETTING: India. PARTICIPANTS: All adult populations resident in India. MAIN OUTCOME MEASURES: 1. Trialled interventions and outcomes 2. Extent and efficacy of current management strategies 3. Above outcomes by subgroup. RESULTS: We found information regarding current management - particularly regarding the implementation of national guidelines and primary prevention - to be minimal. This led to difficulty in interpreting studies of management strategies, which were varied and generally of positive effect. Data regarding current management outcomes were very few. CONCLUSIONS: The current understanding of management strategies for COPD in India is limited due to a lack of published data. Determination of the extent of current use of management guidelines, availability and use of treatment, and current primary prevention strategies would be useful. This would also provide evidence on which to interpret existing and future studies of management outcomes and novel interventions
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