22 research outputs found
Biosorption of Cadmium by Mangrove-Derived Cyanobacteria (Gloeocapsa sp ARKK3)
Dried microbial biomass of Gloeocapsa sp. Trichoderma, and Thrustochytrids used as bioadsorbent for the removal of cadmium in the artificial sewage. Among the three species the maximum adsorption recorded in Gloeocapsa sp. biomass. For the augmentation of cadmium removal in sewage, adsorption process conditions was statistically optimized by the method of response surface methodology (RSM) and adsorption kinetics also studied. The important factors of temperature, pH, adsorbent dosage and processing time were selected for optimization, and it was done with 30 experimental cycles derived from centre composite design (CCD). The statistical optimization reveled that optimized condition for cadmium removal was pH 9, temperature 40ºC, adsorbent dosage 0.6 mg.l-1 and 60 minutes. Finally in this condition was experimentally proved with yield of cadmium removal of 92.9 % under statistically optimized condition. In the case of the adsorption kinetic Gloeocapsa sp. biomass showed a significant adsorption capacity of qmax-56.96 (mg.g-1). The present study concluded that the microbial dried biomass derived from marine Gloeocapsa sp. was a potent source for the removal of the cadmium in the sewage waste water
De Novo Generated Human Red Blood Cells in Humanized Mice Support Plasmodium falciparum Infection
Immunodeficient mouse–human chimeras provide a powerful approach to study host specific pathogens like Plasmodium (P.) falciparum that causes human malaria. Existing mouse models of P. falciparum infection require repeated injections of human red blood cells (RBCs). In addition, clodronate lipsomes and anti-neutrophil antibodies are injected to suppress the clearance of human RBCs by the residual immune system of the immunodeficient mice. Engraftment of NOD-scid Il2rg[superscript -/-] mice with human hematopoietic stem cells leads to reconstitution of human immune cells. Although human B cell reconstitution is robust and T cell reconstitution is reasonable in the recipient mice, human RBC reconstitution is generally poor or undetectable. The poor reconstitution is mainly the result of a deficiency of appropriate human cytokines that are necessary for the development and maintenance of these cell lineages. Delivery of plasmid DNA encoding human erythropoietin and interleukin-3 into humanized mice by hydrodynamic tail-vein injection resulted in significantly enhanced reconstitution of erythrocytes. With this improved humanized mouse, here we show that P. falciparum infects de novo generated human RBCs, develops into schizonts and causes successive reinvasion. We also show that different parasite strains exhibit variation in their ability to infect these humanized mice. Parasites could be detected by nested PCR in the blood samples of humanized mice infected with P. falciparum K1 and HB3 strains for 3 cycles, whereas in other strains such as 3D7, DD2, 7G8, FCR3 and W2mef parasites could only be detected for 1 cycle. In vivo adaptation of K1 strain further improves the infection efficiency and parasites can be detected by microscopy for 3 cycles. The parasitemia ranges between 0.13 and 0.25% at the first cycle of infection, falls between 0.08 and 0.15% at the second cycle, and drops to barely detectable levels at the third cycle of infection. Compared to existing mouse models, our model generates human RBCs de novo and does not require the treatment of mice with immunomodulators.Singapore. National Research Foundation (Singapore-MIT Alliance for Research and Technology
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Snakebite and its socio-economic impact on the rural population of Tamil Nadu, India
BACKGROUND:
Snakebite represents a significant health issue worldwide, affecting several million people each year with as many as 95,000 deaths. India is considered to be the country most affected, but much remains unknown about snakebite incidence in this country, its socio-economic impact and how snakebite management could be improved.
METHODS/PRINCIPAL FINDINGS:
We conducted a study within rural villages in Tamil Nadu, India, which combines a household survey (28,494 people) of snakebite incidence with a more detailed survey of victims in order to understand the health and socio-economic effects of the bite, the treatments obtained and their views about future improvements. Our survey suggests that snakebite incidence is higher than previously reported. 3.9% of those surveyed had suffered from snakebite and the number of deaths corresponds to 0.45% of the population. The socio-economic impact of this is very considerable in terms of the treatment costs and the long-term effects on the health and ability of survivors to work. To reduce this, the victims recommended improvements to the accessibility and affordability of antivenom treatment.
CONCLUSIONS:
Snakebite has a considerable and disproportionate impact on rural populations, particularly in South Asia. This study provides an incentive for researchers and the public to work together to reduce the incidence and improve the outcomes for snake bite victims and their families
Mechanical, structural and tribological properties of superaustenitic stainless steel submitted at solution heat treatment
Optimization of Micro-Alloying Elements for Mechanical Properties in Normalized Cast Steel Using Taguchi Technique
In this study, Taguchi method is used to find out the effect of micro alloying elements like vanadium, niobium and titanium on the hardness and tensile strength of the normalized cast steel. Based on this method, plan of experiments were made by using orthogonal arrays to acquire the data on hardness and tensile strength. The signal to noise ratio and analysis of variance (ANOVA) are used to investigate the effect of these micro alloying elements on these two mechanical properties of the micro alloyed normalized cast steel. The results indicated that in the micro alloyed normalized cast steel both these properties increases when compared to non-micro-alloyed normalized cast steel. The effect of niobium addition was found to be significantly higher to obtain higher hardness and tensile strength when compared to other micro alloying elements. The maximum hardness of 200HV and the maximum tensile strength of 780 N/mm2 were obtained in 0.05%Nb addition micro alloyed normalized cast steel. Micro-alloyed with niobium normalized cast steel have the finest and uniform microstructure and fine pearlite colonies distributed uniformly in the ferrite. The optimum condition to obtain higher hardness and tensile strength were determined. The results were verified with experiments
Investigation of Shrinkage Defect in Castings by Quantitative Ishikawa Diagram
Metal casting process involves processes such as pattern making, moulding and melting etc. Casting defects occur due to combination of various processes even though efforts are taken to control them. The first step in the defect analysis is to identify the major casting defect among the many casting defects. Then the analysis is to be made to find the root cause of the particular defect. Moreover it is especially difficult to identify the root causes of the defect. Therefore, a systematic method is required to identify the root cause of the defect among possible causes, consequently specific remedial measures have to be implemented to control them. This paper presents a systematic procedure to identify the root cause of shrinkage defect in an automobile body casting (SG 500/7) and control it by the application of Pareto chart and Ishikawa diagram. with quantitative Weightage. It was found that the root causes were larger volume section in the cope, insufficient feeding of riser and insufficient poured metal in the riser. The necessary remedial measures were taken and castings were reproduced. The shrinkage defect in the castings was completely eliminated
Photoluminescences properties of lanthanum-silver co-doped ZnO nano particles
Recently, transition metal (TM) and rare earth ion doped II–VI semiconductor nanoparticles have received much attention because such doping can modify and improve optical properties of II–VI semiconductor nanoparticles by large amount. In this study, undoped, La doped and La+Ag co-doped ZnO nano particles have been successfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcinated at 600 °C for 2 h. The effect of lanthanum and lanthanum-silver incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescences properties were found to be enhanced for the La and La+Ag co-doped ZnO nanoparticles
Study on the Synthesis, Structural, Optical and Electrical Properties of ZnO and Lanthanum Doped ZnO Nano Particles by Sol-Gel Method
International audienceIn this study, pure and lanthanum doped ZnO nano particles have been succaessfully synthesized by sol-gel method using the mixture of Zinc acetate dihydrate and ethanol solution. The powders were calcination at 600°C for 2h. The effect of lanthanum incorporation on the structure, morphology, optical and electrical conductivity were examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Absorption (EDAX), Fourier transform infrared spectroscopy (FTIR), UV and Photo Luminescence (PL) Characterization. The average particle size of the synthesized ZnO nanoparticles is calculated using the Scherrer formula and is found to be of less than 20 nm. Luminescence as well as conductivity properties were found to be enhanced for the La doped ZnO nanoparticles. Introduction. Synthesize and study of nanostructured materials have become a major attractive interdisciplinary area of research over the past few decades. Recently rare earth ion doped II-IV semiconductor nano particles have received much attention because such doping can modify and improve optical properties of II-VI semiconductor nanoparticles by large amount [1-4]. Zinc Oxide is a transparent electro conductive and piezo electric material. Zinc Oxide is an excellent ultraviolet absorber and antibacterial agent. ZnO is one of the metal oxides which attracts due to its direct band gap energy of 3.37eV and large excitation binding energy of 60 meV at room temperature which provides excitonic emission more efficiently even at high temperature. ZnO is particularly important because of their unique optical/electronic properties and promising applications in various fields such as photonic catalysis [5], light emitting diodes [6], field emission, gas sensors [7], fluorescent materials and solar cells [8]
Synthesis, microstructure and mechanical properties of Al-Si-Mg alloy hybrid (zircon + alumina) composite
20-26<span style="font-size:11.0pt;mso-bidi-font-size:
10.0pt;font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="" lang="EN-US">In
the present work, a detailed study of zircon and alumina reinforcement in to
the matrix of Al-Si-Mg alloy on the microstructure and wear behavior has been
carried out. To study the effect of reinforcement on the wear behaviour of
these composites, the alloy is reinforced with different amounts of zircon and
alumina particles limiting to the total 15 wt%. The microstructure of these
hybrid composites reveal uniform distribution of the reinforced particles.
Composites are found to exhibit better hardness and wear resistance compared to
base alloy. Among the different composites, the one reinforced with 3.75 wt% of
zircon and 11.25 wt% of alumina particles (composite B) is found to be the best
combination exhibiting high hardness and low wear rate at a test load of 15 N.
SEM analysis of worn surface of hybrid composites shows no evidence of plastic
deformation of matrix phase. Abrasive wear mechanism and particle pull out is
the common feature observed from all the composites.</span
In vivo splenic clearance correlates with In vitro deformability of red blood cells from plasmodium yoelii-infected mice
Recent experimental and clinical studies suggest a crucial role of mechanical splenic filtration in the host's defense against malaria parasites. Subtle changes in red blood cell (RBC) deformability, caused by infection or drug treatment, could influence the pathophysiological outcome. However, in vitro deformability measurements have not been directly linked in vivo with the splenic clearance of RBCs. In this study, mice infected with malaria-inducing Plasmodium yoelii revealed that chloroquine treatment could lead to significant alterations to RBC deformability and increase clearance of both infected and uninfected RBCs in vivo. These results have clear implications for the mechanism of human malarial anemia, a severe pathological condition affecting malaria patients.Published versio