Ca2+ Efflux from Temperature Sensitive Liposomes and In Situ Formation of Metal Cholate Liposome Gels: Basic Studies and Potentials for Sustained Site-Specific Drug Delivery

Liposomes or vesicles are biomimetic close containers for the delivery of drugs at the local site for an extended period of time. On the other hand hydrogels which are three-dimensional hydrophilic matrices are another class of popular materials for sustained release. Such hybrids combine the features of liposomes and polymer to ensure a sustained local drug delivery. In the present work a novel liposome/hydrogel soft assembly is explored which may be potentially useful for drug delivery applications. We report thermally triggered release of Ca+2 from temperature sensitive liposomal  compartments constituted as 90 mol% DPPC and 10 mol% DMPC to induce rapid gelation of a solution of calcium cholate and AgNO3 (extravesicular precursor fluid). Calcium chloride loaded liposomes were prepared using the lipid film rehydration method. The formation of unilamellar bilayer were supported by the fluorometric studies using a compatible and labeled fluoropore (NBD-PS). Hydrogels were obtained by mixing Ca+2 loaded liposome with extravesicular precursor fluid and incubating the content at 37oC. The concentration of the cholate during gelation was sublytic in order to avoid vesicle solubilization. The integrity of liposomes within the hydrogels were preserved during gelation as confirmed by transmission electron microscopy (TEM). The presence of low concentration of cholate (for example 0.05 mM) also permitted spectrophotometric monitoring of Ca+2 efflux for Ca-vesicles employing calcium sensitive dye, Arsenazo III.  We expect that this simple experiment may also be useful for developing implantable as well as rapidly gelling injectable biomaterials for site-specific drug delivery. The present work is also significant as the antimicrobial properties of hydrogels containing silver has been widely recognized for its therapeutic profile.   Keywords: Liposome, triggered release, metal cholate liposome gel, site-specific delivery

Siderophore-Producing Bacteria from a Sand Dune Ecosystem and the Effect of Sodium Benzoate on Siderophore Production by a Potential Isolate

Bioremediation in natural ecosystems is dependent upon the availability of micronutrients and cofactors, of which iron is one of the essential elements. Under aerobic and alkaline conditions, iron oxidizes to Fe+3 creating iron deficiency. To acquire this essential growth-limiting nutrient, bacteria produce low-molecular-weight, high-affinity iron chelators termed siderophores. In this study, siderophore-producing bacteria from rhizosphere and nonrhizosphere areas of coastal sand dunes were isolated using a culture-dependent approach and were assigned to 8 different genera with the predominance of Bacillus sp. Studies on the ability of these isolates to grow on sodium benzoate revealed that a pigmented bacterial culture TMR2.13 identified as Pseudomonas aeruginosa showed growth on mineral salts medium (MSM) with 2% of sodium benzoate and produced a yellowish fluorescent siderophore identified as pyoverdine. This was inhibited above 54 μM of added iron in MSM with glucose without affecting growth, while, in presence of sodium benzoate, siderophore was produced even up to the presence of 108 μM of added iron. Increase in the requirement of iron for metabolism of aromatic compounds in ecosystems where the nutrient deficiencies occur naturally would be one of the regulating factors for the bioremediation process

Challenges and opportunities in 2D heterostructures for electronic and optoelectronic devices

Two-dimensional (2D) materials such as graphene, transition metal dichalcogenides (TMDs), and their heterojunctions are prospective materials for future electronics, optoelectronics, and quantum technologies. Assembling different 2D layers offers unique ways to control optical, electrical, thermal, magnetic, and topological phenomena. Controlled fabrications of electronic grade 2D heterojunctions are of paramount importance. Here, we enlist novel and scalable strategies to fabricate 2D vertical and lateral heterojunctions, consisting of semiconductors, metals, and/or semimetals. Critical issues that need to be addressed are the device-to-device variations, reliability, stability, and performances of 2D heterostructures in electronic and optoelectronic applications. Also, stacking order-dependent formation of moir\ue9 excitons in 2D heterostructures are emerging with exotic physics and new opportunities. Furthermore, the realization of 2D heterojunction-based novel devices, including excitonic and valleytronic transistors, demands more extensive research efforts for real-world applications. We also outline emergent phenomena in 2D heterojunctions central to nanoelectronics, optoelectronics, spintronics, and energy applications

A CROSS-SECTIONAL STUDY EVALUATION OF DIAGNOSTIC IMPLICATIONS OF PLATELET INDICES IN THROMBOCYTOPENIA.

Introduction: Thrombocytopenia (TCP) refers to a reduction of platelet count below 150 x 109/ L; it’s not a disease entity by itself, but a finding that may result from a number of disease processes. Automated hematology analyzers that determine the Mean Platelet Volume (MPV), Platelet Distribution Width (PDW), Plateletcrit (PCT), and Platelet Large Cell Ratio (P-LCR), could be very helpful to facilitate the differential diagnosis of thrombocytopenia and to monitor thrombocytopenic conditions. Materials and methods: A cross-sectional study of platelet indices of 512 thrombocytopenic samples by automated hematology analyzers was done. Results: The cases of thrombocytopenia were classified into hypo-productive (362 cases) and hyper-destructive (150) groups. A most common cause of hypo-productive and hyper-destructive thrombocytopenia was Aplastic anemia and ITP, respectively. All the indices were significantly higher (p-value < 0.05) in hyper-destructive TCP compared to hypo-productive TCP, except Plateletcrit. Conclusion: The results of the present study show platelet indices to be a useful and reliable test to differentiate between hyper-destructive thrombocytopenia from the hypo-productive type with statistically significant differences

Distribution and sources of polychlorinated biphenyls in air, dust and sediment from India

Persistent organic pollutants, such as polychlorinated biphenyls (PCBs), pose a serious risk for human health and the environment. In this study, PCBs contamination and sources of ambient air, road dust, and sediments in the most polluted city in India, Raipur, has been measured over the period 2008–2015. The seasonal variations of particulate matter (PM), elemental carbon (EC), organic carbon (OC), and carbonate carbon (CC) were studied, and maximum concentrations were detected in the December–January period each year. Total PCBs concentrations in the ambient air (associated with PM), road dust, and sediments samples during 2008 were in the 186–645 pg m−3, 102–537, and 241–538 ng g−1 range, respectively. 2-chlorobiphenyl (PCB-1) and 4-chlorobiphenyl (PCB-3) were the dominant chemical compounds identified. A substantial vertical migration of the PCBs in the sediments was observed. Concentration variations (spatial and temporal), correlations, and sources of PCB are discussed. In particular, an average increment rate of 6.2%, 4.9%, and 5.4% of PCBs concentration in the particulate matter (PM10), road dust, and sediments, respectively, was observed over the 2008–2015 period. The reported data points to India's low degree of accomplishment of the Stockholm Convention's requirement to phase out the use of PCBs in equipment by 2025 and ensure elimination of PCBs by 2028

Remoteness and Chronic Poverty in a Forest Region of Southern Orissa: A Tale of Entitlement Failure and State Apathy

This paper seeks to examine the extent, nature and structural factors (social, physical and legal) leading to poverty in southern region of Orissa, which has a dubious distinction of having the highest incidence of poverty among rural regions in India. The analysis is based on both secondary as well as primary data; the later pertain to a sample of households from four villages in Southern Orissa. The analysis reinstates the fact that chronic poverty in terms of- both severity and long duration- is an overarching reality for almost nine out of ten households in the region. Similarly, it highlights severe deprivation in terms of food consumption, with a significantly large proportion of households consuming just about half of the prescribed norm of cereal intake. The paper dwells at length on the existing policy initiatives and suggests alternative framework for addressing the issue of chronic chronic poverty in the region.poverty, forest, India, Orissa

A study on effect of ethanolic extract of triticum aestivum in anxiety behaviour induced by chronic unpredictable stress in a rat model

Objectives- This study was undertaken to evaluate the effect of Ethanolic extract of Triticum aestivum (TAE) on different anxiety like behaviour induced by Chronic unpredictable stress in wistar albino rats. Materials and methods- Effect of TAE was studied on chronic unpredictable stress induced rats. The reference standard drug (Diazepam 1mg/kg po) and the test drug, TAE at doses of 150mg/kg and 200mg/kg b.w. were given to rats for 14 days. Anti-anxiety activity was assessed by using Light and Dark Box test. Then the locomotor activity of rats was assessed as indicator of anxiety. Animals were sacrificed at the end of this experiment..The adrenal and spleen weight, ulcer index as well as various biochemical parameters like Malondialdehyde (MDA) and Superoxide dismutase (SOD) were assessed. Results- The stay in Light box was increased, rearing activity was increased to a significant level in both Diazepam and TAE-200 mg/kg treated rats and this effect was comparable to that of normal non-stressed vehicle treated rats. Chronic stress caused elevation of MDA and depression of SOD level which is reversed by Ethanolic extract of Triticum aestivum (TAE)

First-principles study of a vertical spin switch in atomic scale two-dimensional platform

High in-plane charge carrier mobility and long spin diffusion length makes graphene a unique material for spin-based devices. However, in a vertical graphene junction, the 2pz orbitals of carbon atoms in graphene can be tuned via suitable magnetic substrates; this would affect the spin injection into graphene. Here, a vertical spin switch has been designed by embedding a single layer of graphene as a tunnel layer between the Ni (1 1 1) substrate. Periodic density functional approach in conjunction with Julliere’s model is used to calculate the tunnel magnetoresistance (TMR). Further, single-layered hexagonal Boron Nitride (h-BN) is sandwiched between the graphene and Ni (1 1 1) substrate to understand the role of hybridization at the interface on TMR. Our calculation shows that in contrast to the graphene junction, a much higher TMR value is obtainable in the case of the graphene/h-BN multi-tunnel junction (MTJ). The TMR in graphene junction is found to decrease with the increase of an externally applied electric field, and drops to zero for a field greater than equal to 0.16 V/Å. Similar phenomenon was observed in the case of h-BN/graphene MTJ, where TMR value remains unchanged for electric field up to 0.1 V/Å beyond which it drops to zero. The change in hybridization and charge-carrier-population at the interface modifies the magnetic exchange interaction and magnetic anisotropy resulting in a spin flip at interface, leads to rapid drop in TMR after a threshold electric field. The high and tunable TMR value suggests h-BN assisted high performance graphene based vertical spin switch

Enhancement of Mechanical, Thermal and Morphological Properties of Eleusine Indica Grass Fiber Reinforced Epoxy Composites

This research focuses on developing a new material by reinforcing chemically treated Eleusine Indica (EI) fiber with epoxy resin as matrix. Composites using varying wt% of treated EI fibers were fabricated taking epoxy as matrix. The effect of chemical treatment and fiber loading on various mechanical properties, thermal, and morphology using a scanning electron microscope (SEM) was investigated. From the results obtained, it is obvious that the mechanical and thermal properties of composites reinforced with chemically treated fibers were enhanced due to fiber surface modification which helps in better bonding with matrix. Moreover, the composites with 20 wt% fiber concentration shows good tensile strength, Young’s modulus, impact strength and was found to be 79.31MPa, 3.84 GPa, 32.24 KJ/m2 respectively. At this fiber loading the composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and thermogravimetric (TGA) and compared with untreated fiber reinforced composites and neat epoxy. Finally, the failure analysis of fracture surface due to delimitation, pull-out of the fibers, percentage of voids, and composite fracture has been verified using scanning electron microscope. The findings provide manufacturers and engineers with a general concept of how to employ the composites to make low-weight automotive parts for improved fuel efficiency