295 research outputs found

    Low Cost Efficient Treatment for Contaminated Water

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    8 p.International audienceHeavy metals pose a risk of contaminating groundwater and surface water sources due to geogenic activities, industries and agricultural sources. The removal of heavy metals e.g., cadmium, lead, and zinc from drinking, industrial and irrigation water at low concentrations is a recurring challenge, especially in developing countries. Biosorption is a relatively new process that has proved to be very promising for removal of heavy metals from aqueous solutions. The removal of contaminants viz., Cd(II), Pb(II) and Zn(II) by rice husk (lignin containing material) was studied in the laboratory. Batch studies were performed to evaluate the influences of various experimental parameters like pH, initial concentration of metal ions, biosorbent dosage and contact time. The selectivity of the process is also studied. The findings show the efficiency of material for the removal these contaminants with a low concentration in the range 1-5 mg/L. The removal efficiency is up to 95%

    Implants for site-specific drug delivery

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    No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38567/1/770020309_ftp.pd

    Development and implementation of Water Safety Plan at peri-urban village in India: A case study

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    Water Safety Plan is a risk based approach to reliably deliver safe drinking water to end-client. The approach emphasizes on system assessment, identification of hazards, use of simple indicators to monitor control points and periodic verification. A WSP was developed for a peri-urban village Bhendala. This study discusses the step-by-step tasks undertaken to promote improvement in water quality, quantity and awareness among community and suggest appropriate actions required to safeguard public health from contaminated water-related risks. Be the risks identified, this study suggests there is need to give continuous assistance to the local water management team for the maintainability of the WSP

    The efficacy of controlled release -sotalol-polyurethane epicardial implants for ventricular arrhythmias due to acute ischemia in dogs

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    Epicardially implanted -sotalol polyurethane composite matrices for preventing ischemic ventricular arrhythmias were studied in open chest dogs under general anesthesia. -sotalol was combined with a polyureapolyurethane (3:7) in solvent-cast films, which were characterized in vitro for their drug release at 37[deg]C at pH 7.4 (0.05 M K2HPO4). -sotalol in vitro release occurred rapidly in an initial burst phase, with roughly 20% released within the first five min, and 90% by 60 min. Thereafter, an exponentially decreasing release rate was observed with matrix depletion by five hours. In the animal studies, the left anterior descending coronary artery (LAD) was occluded for 10 min on an hourly basis for up to five occlusions. 10 min prior to the third LAD occlusion, either a -sotalol matrix or a vehicle matrix (control) was placed on either the ischemic or nonischemic left ventricular epicardium. The study was then continued observing the effects of matrix placement on occlusions 3,4, and 5. 200 mg -sotalol matrices, which delivered a net dose of 1.2 mg/kg, effectively inhibited ventricular arrhythmias only if placed on the left ventricular ischemic zone. Placement of 200 mg -sotalol matrices in the nonischemic zone was ineffective for significantly reducing the occurrence of ventricular arrhythmias. Furthermore, -sotalol controlled release matrices were ineffective for preventing ventricular fibrillation (VF) regardless of dose or placement site. 200 mg ischemic zone -sotalol matrices resulted in plasma sotalol levels in regional coronary venous samples ranging from 3.5 [mu]g/ml to 10.4 [mu]g/ml However, peripheral sotalol levels obtained simultaneously ranged from 0.23 [mu]g/ml to 0.78 [mu]g/ ml. It is concluded that epicardial -sotalol controlled release matrices inhibited ischemic ventricular arrhythmias, but not VF, if placed in the left ventricular ischemic zone during repeated LAD occlusions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31043/1/0000720.pd

    A DNA controlled-release coating for gene transfer: Transfection in skeletal and cardiac muscle

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    In this paper we report a novel technique of DNA-polymer coating for gene transfer. A proprietary DNA polymer solution was used for thin-layer coating on a chromic gut suture as a model study. The coated sutures were characterized for physical properties such as coating thickness, mass of the DNA deposited on the suture, surface characteristics as determined by scanning electron microscopy, and in vitro DNA release characteristics under simulated physiologic conditions. The in vivo gene transfection using DNA-coated sutures was demonstrated in rat skeletal muscle and in canine atrial myocardium. A heat-stable human placental alkaline phosphatase (AP) plasmid was used as a marker gene. Incisions of 1 to 1.5 cm were made in the rat skeletal muscles or the canine atrial myocardium. The sites were closed with either the DNA-coated sutures or control sutures. Two weeks after the surgery, the tissue samples adjacent to the suture lines were retrieved and analyzed for AP activity. The DNA-coated sutures demonstrated a sustained release of the DNA under in vitro conditions, with an ∼84% cumulative DNA release occurring in 26 days. An agarose gel electrophoresis of the DNA samples released from the suture demonstrated two bands, with the lower band corresponding to the input DNA (supercoiled). It seems that there was a partial transformation of the DNA from a supercoiled to an open circular form due to the polymer coating. The tissue sites, which received the DNA-coated sutures, demonstrated a significantly higher AP activity compared with the tissue sites that received control sutures. In the rat studies, the mean AP activity (square root of cpm/ µg protein) was 43.6 ± 3.3 vs 20.6 ± 2.1 ( p = 0.001) at the control sites. Similarly, in the canine studies, the AP activity was 73.6 ± 7.4 Vs 21.6 ± 1.4 ( p = 0.0009) at the control sites. Thus, our studies demonstrated a successful gene transfer using our DNA-polymer coating technique. This technique could be useful for coating sutures used in vascular and general surgery, and also for coating medical devices, such as stents, catheters, or orthopedic devices, to achieve a site-specific gene delivery.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34492/1/14_ftp.pd

    Determination of Debye Temperatures and Lamb-Mössbauer Factors for LnFeO3 Orthoferrite Perovskites (Ln = La, Nd, Sm, Eu, Gd)

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    Lanthanide orthoferrites have wide-ranging industrial uses including solar, catalytic and electronic applications. Here a series of lanthanide orthoferrite perovskites, LnFeO3 (Ln = La; Nd; Sm; Eu; Gd), prepared through a standard stoichiometric wet ball milling route using oxide precursors, has been studied. Characterisation through X-ray diffraction and X-ray fluorescence confirmed the synthesis of phase-pure or near-pure LnFeO3 compounds. 57Fe Mössbauer spectroscopy was performed over a temperature range of 10 K to 293 K to observe hyperfine structure and to enable calculation of the recoil-free fraction and Debye temperature (θD) of each orthoferrite. Debye temperatures (Ln = La 474 K; Nd 459 K; Sm 457 K; Eu 452 K; Gd 473 K) and recoil-free fractions (Ln = La 0.827; Nd 0.817; Sm 0.816; Eu 0.812; Gd 0.826) were approximated through minimising the difference in the temperature dependent experimental Centre Shift (CS) and theoretical Isomer Shift (IS), by allowing the Debye temperature and Isomer Shift values to vary. This method of minimising the difference between theoretical and actual values yields Debye temperatures consistent with results from other studies determined through thermal analysis methods. This displays the ability of variable-temperature Mössbauer spectroscopy to approximate Debye temperatures and recoil-free fractions, whilst observing temperature induced transitions over the temperature range observed. X-ray diffraction and Rietveld refinement show an inverse relationship between FeO6 octahedral volume and approximated Debye temperatures. Raman spectroscopy show an increase in the band positions attributed to soft modes of Ag symmetry, Ag(3) and Ag(5) from La to GdFeO3 corresponding to octahedral rotations and tilts in the [010] and [101] planes respectively
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