Biological remediation of trivalent chromium from effluents

Out of the industrial waste streams/effluents entering in the aquatic system containing metallic species, tanneries release high amounts of chromium, an anthropogenic pollutant because of use of basic chromium sulphate in the tanning processes. Trivalent chromium, Cr(lll) is the targeted ionic species for removal by biosorption on a fungal species in this work, as the technique has inherent merit of easy adsorbent regeneration and lower capital costs. The study involves the use of Aspergillus niger (A.niger), to remediate chromium from a model tanning solution with Cr(lll) concentration of 500 ppm. The fungal species was grown in Czapek Dox media at 2.5 pH and 35°C temperature and its biomass was used in various forms such as live, autoclaved and alkali treated. With 1% (w/v) alkali treated biomass, the biosorption of chromium reached to a maximum of 91% for a feed concentration of 500 ppm in 2h time at 2.5 pH, 35°C and AIR (Adsorbent : Solution Volume) ratio of 1/100. The lower biosorption of metal (42 ¬44%) was observed with live and autoclaved biomass. The biosorption of chromium(111) on the fungal biomass was explained with various isotherms and fitted to the kinetic model involving first order expression. The study focuses on establishing the mechanism of bioremediation of chromium on A.niger

Environmental Quality of the Boula-Nuasahi Chromite Mine Area in India

Chromite mining can create hostile conditions for organisms in the surrounding environment. Overburden soil and mine water samples were collected and analyzed for their microbial diversity, nutrient content, and water quality at the Boula-Nuasahi Mine. Most of the water parameters that were measured exceed national/international standards. The microbial population was low (soil: 45 ± 0.06 9 105 bacteria, 20 ± 0.03 9 105 fungus) and the overburden soils have a low nutrient (N, P, K) content. The metal ions were found to have leached to nearby agriculture lands, making them less fertile for crop production.Overburden dumps and seepage water were found to be the main sources of chromium pollution

Characterization Of Glipizide-Loaded Polymethacrylate Microspheres Prepared By An Emulsion Solvent Evaporation Method

Purpose: The purpose of the present investigation was to formulate and evaluate microencapsulated glipizide produced by the emulsion – solvent evaporation method, Method: Microspheres were prepared using polymethacrylate polymers (Eudragit® RS 100 and RL 100) by solvent evaporation method and characterized for their micromeritic properties and drug loading, as well as by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. In vitro release studies were performed in phosphate buffer (pH 7.4). Result: The resulting microspheres obtained by solvent evaporation method were white and free flowing in nature. The mean particle size of microspheres ranged from 420 - 660 μm and the encapsulation efficiencies ranged from 40.27 - 86.67 %. The encapsulation efficiency was also found to be dependant on nature of polymer used in the formulation. The infrared spectra confirmed the stable character of glipizide in the drug-loaded microspheres. Scanning electron microscopy revealed that the microspheres were spherical in nature. From the in vitro drug dissolution studies it was found that the sustaining effect of microspheres depended on the polymer concentration, amount of dispersant used and the type of polymer used in the formulation. The mechanism of drug release from the microspheres was found to be non-Fickian type. Conclusion: Eudragit® microspheres containing glipizide could be prepared successfully by using an emulsion solvent evaporation technique using polymethacrylate polymers, which will not only sustain the release of drug but also manage the complicacy of the diabetes in a better manner. Keywords: glipizide, Eudragit®, microspheres, controlled release, polymethacrylate.Tropical Journal of Pharmaceutical Research Vol. 7 (1) 2008: pp. 879-88

Microbial Bioremediation of Chromium: A promising approach of environmental microbiology

Heavy-metal pollution represents an important environmental problem due to the toxic effects of metals, and their accumulation throughout the food chain leading to serious ecological and health problems. Metal remediation through common physico-chemical techniques is expensive and unsuitable in case of voluminous effluents containing complexing organic matter and low metal contamination. Biotechnological approaches that are designed to address to such problems have, therefore, received great deal of attention in the recent years. Microorganisms are intimately involved in metal biogeochemistry with a variety of processes determining mobility, and therefore, bioavailability and bioremediation. The balance between mobilization and immobilization varies depending on the organisms involved, their environment and physicochemical conditions. Metal mobilization can arise from a variety of leaching mechanisms, complexation by metabolites and siderophores, and methylation, where this results in volatilization. Immobilization can result from sorption to biomass or exopolymers, transport and intracellular sequestration or precipitation as organic and inorganic compounds, e.g., oxalates (fungi) and sulfides. This chapter discusses the principle of microbial-metal interaction and mechanisms of the bioremediation process and also includes the chromium bioremediation using native isolates. Some details on bio-reduction of chromium (VI) and chromium (III) from their specific sources are described to exemplify the role of metal tolerant native microbial isolates

The correlation of cardiovascular risk factors and angiographic findings with serum vitamin D levels in patients undergoing coronary angiography

Background: Studies regarding correlation of various conventional risks factors for Coronary Artery Disease (CAD) are many. Keeping in mind the scarcity of studies regarding Vit-D Deficiency (VDD), a new risk factor in CAD, present study was conducted to correlate Vit-D level with conventional risk factors and Coronary Angiography (CAG).Methods: Hundred adult patients admitted to Medicine and Cardiology undergoing CAG with suspected or established CAD were kept in study. Patients having renal, hepatic, parathyroid disease, osteomalacia and patients taking drugs interfering with Vitamin D (Vit-D) metabolism were excluded. After detailed history and thorough clinical examination, routine investigations and 25-(OH) D level was estimated. Subsequently patients underwent CAG. Statistical analysis by Mann Whitey test and Chi-square Test was done and inference was drawn.Results: 100 patients in different age groups had hypertension (HTN) in 53, diabetics mellitus (DM) 39, dyslipidemia 62, smokers 38 and family history of CAD 19. CAG showed normal coronaries in 4, Single Vessel Disease (SVD) in 30, double vessel diseases (DVD) 43 and triple vessel disease (TVD) 22. Vit-D level 30ng/ml (normal) in 10. VDD was profound in 51-60 and 61-70 years age groups. Statistical correlation of VDD was not significant with conventional risk factors, but statistically significant correlation of VDD was observed with dyslipidemia and CAG findings in our study.Conclusions: Like earlier studies we observed significant correlation of Vit-D levels with CAD. Though dyslipidemia was significantly correlated with VDD, correlation of other conventional risk factors like age, sex, HTN, DM, smoking and family history was not found. We conclude from this study presence of significant association of VDD with severe CAD. DVD and TVD by CAG were common with low Vit-D levels

Complete Break Up of Ortho Positronium (Ps)- Hydrogenic ion System

The dynamics of the complete breakup process in an Ortho Ps - He+ system including electron loss to the continuum (ELC) is studied where both the projectile and the target get ionized. The process is essentially a four body problem and the present model takes account of the two centre effect on the electron ejected from the Ps atom which is crucial for a proper description of the ELC phenomena. The calculations are performed in the framework of Coulomb Distorted Eikonal Approximation. The exchange effect between the target and the projectile electron is taken into account in a consistent manner. The proper asymptotic 3-body boundary condition for this ionization process is also satisfied in the present model. A distinct broad ELC peak is noted in the fully differential cross sections (5DCS) for the Ps electron corroborating qualitatively the experiment for the Ps - He system. Both the dynamics of the ELC from the Ps and the ejected electron from the target He+ in the FDCS are studied using coplanar geometry. Interesting features are noted in the FDCS for both the electrons belonging to the target and the projectile.Comment: 14 pages,7 figure

Ground Delay Program Analytics with Behavioral Cloning and Inverse Reinforcement Learning

We used historical data to build two types of model that predict Ground Delay Program implementation decisions and also produce insights into how and why those decisions are made. More specifically, we built behavioral cloning and inverse reinforcement learning models that predict hourly Ground Delay Program implementation at Newark Liberty International and San Francisco International airports. Data available to the models include actual and scheduled air traffic metrics and observed and forecasted weather conditions. We found that the random forest behavioral cloning models we developed are substantially better at predicting hourly Ground Delay Program implementation for these airports than the inverse reinforcement learning models we developed. However, all of the models struggle to predict the initialization and cancellation of Ground Delay Programs. We also investigated the structure of the models in order to gain insights into Ground Delay Program implementation decision making. Notably, characteristics of both types of model suggest that GDP implementation decisions are more tactical than strategic: they are made primarily based on conditions now or conditions anticipated in only the next couple of hours

Noninvasive Monitoring of Placenta-Specific Transgene Expression by Bioluminescence Imaging

BACKGROUND: Placental dysfunction underlies numerous complications of pregnancy. A major obstacle to understanding the roles of potential mediators of placental pathology has been the absence of suitable methods for tissue-specific gene manipulation and sensitive assays for studying gene functions in the placentas of intact animals. We describe a sensitive and noninvasive method of repetitively tracking placenta-specific gene expression throughout pregnancy using lentivirus-mediated transduction of optical reporter genes in mouse blastocysts. METHODOLOGY/PRINCIPAL FINDINGS: Zona-free blastocysts were incubated with lentivirus expressing firefly luciferase (Fluc) and Tomato fluorescent fusion protein for trophectoderm-specific infection and transplanted into day 3 pseudopregnant recipients (GD3). Animals were examined for Fluc expression by live bioluminescence imaging (BLI) at different points during pregnancy, and the placentas were examined for tomato expression in different cell types on GD18. In another set of experiments, blastocysts with maximum photon fluxes in the range of 2.0E+4 to 6.0E+4 p/s/cm(2)/sr were transferred. Fluc expression was detectable in all surrogate dams by day 5 of pregnancy by live imaging, and the signal increased dramatically thereafter each day until GD12, reaching a peak at GD16 and maintaining that level through GD18. All of the placentas, but none of the fetuses, analyzed on GD18 by BLI showed different degrees of Fluc expression. However, only placentas of dams transferred with selected blastocysts showed uniform photon distribution with no significant variability of photon intensity among placentas of the same litter. Tomato expression in the placentas was limited to only trophoblast cell lineages. CONCLUSIONS/SIGNIFICANCE: These results, for the first time, demonstrate the feasibility of selecting lentivirally-transduced blastocysts for uniform gene expression in all placentas of the same litter and early detection and quantitative analysis of gene expression throughout pregnancy by live BLI. This method may be useful for a wide range of applications involving trophoblast-specific gene manipulations in utero