916 research outputs found

    A review on biogenic synthesis of gold nanoparticles, characterization, and its applications

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    The nano-sized particles make an imprint on us in our daily lives and it has great importance in the numerous fields of biotechnology like the food industry, medical and industrial field. Gold nanoparticles are one of the widely used particles as it has many therapeutic applications, such as drug delivery system for many diseases like cancer, cardiovascular diseases, diabetes mellitus etc. biosensors, and environmental applications of dye degradation, bioremediation of toxic chemicals present in the environment (soil and atmosphere). Gold nanoparticles synthesis by the green route has become the latest development, because of the bioavailability of sources like plants or microorganisms, and it also reduces the utilization of toxic chemicals. This review explains the various microorganisms like bacteria, algae, fungi, actinomycetes and yeast involved in the synthesis of these nanoparticles also elucidate the size, shape and functional groups involved in the synthesis of nanoparticles and its applications

    Synthesis of zinc oxide nanoparticles using plant leaf extract against urinary tract infection pathogen

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    In modern science, Nanotechnology is an ablaze field for the researchers. Zinc oxide nanoparticles (ZnO NPs) are known to be one of the most multifunctional inorganic nanoparticles with its application in treatment of urinary tract infection. Nanoparticles were synthesized using Passiflora caerulea fresh leaf extract and were characterized by UV-visible spectroscopy (UV-vis), X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Energy dispersive analysis of x-ray (EDAX), Atomic force microscopy (AFM). Therefore, the study reveals an efficient, eco-friendly and simple method for the green synthesis of multifunctional ZnO NPs using P. caerulea. Urinary tract infection causing microbes were isolated from the disease affected patient urine sample. The synthesized nanoparticles have been tested against the pathogenic culture showed a very good zone of inhibition compared with plant extract. It indicates the biomedical capability of ZnO NPs

    SYNTHESIS AND CHARACTERIZATION OF SILVER NANOPARTICLES FROM MARINE BROWN SEAWEED AND ITS ANTIFUNGAL EFFICIENCY AGAINST CLINICAL FUNGAL PATHOGENS

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    Objectives: The aim of this study is to synthesize silver nanoparticles using the algal extract of Padina tetrastromatica and evaluate its antifungal activity against pathogenic fungus isolated from clinical samples.Results: Formation of brown color at 15 minutes indicates the production of silver nanoparticles by the extract of brown algae P. tetrastromatica. Surface plasmon resonance band was centered at 440 nm which was observed by UV-vis spectrophotometer. SEM image revealed spherical and cubical nanoparticles with high agglomeration, and energy-dispersive X-ray illustrates elemental components of silver formed at 3 keV. TEM shows spherical, truncated, and ellipsoidal nanoparticles and also it evidences the algae compounds that are capped with nanoparticles. SAED pattern proved four diffraction face-centered cubic rings at (111), (200), (220), and (311) which indicates the crystalline nature of nanoparticles. Silver nanoparticles show high inhibition activity against Fusarium sp, Aspergillus niger, Candida albicans, Aspergillus fumigatus, and Aspergillus flavus at different concentrations. P. tetrastromatica-mediated synthesis of silver nanoparticles shows rapid and eco-friendly silver ion reduction process.Methods: Dried algal biomass was used to prepare the pure algal extract and added with 1 mM AgNO , and the color change was noted and recorded by ultraviolet (UV)-vis spectrophotometer. The morphological characteristics were analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Crystalline structure was analyzed by SAED pattern. Antifungal activity was performed by agar well diffusion method against various pathogenic fungi.Conclusion: Therefore, this present study elucidates that algae-mediated synthesized silver nanoparticles have antifungal activity against pathogenic fungi, so it can be developed as a novel medicine for human welfare in biomedical applications in the near future.Keywords: Padina tetrastromatica, Silver nanoparticles, Transmission electron microscopy, Antifungal activity, Green synthesis.Â

    GREEN SYNTHESIS OF SILVER NANOPARTICLES USING MEDICINAL PLANT ACALYPHA INDICA LEAF EXTRACTS AND ITS APPLICATION AS AN ANTIOXIDANT AND ANTIMICROBIAL AGENT AGAINST FOODBORNE PATHOGENS

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    Objective: In the present study, silver (Ag) nanoparticles was synthesized by traditionally used medicinal plant Acalypha indica, which was characterized using various advanced tools, and its antioxidant as well as antimicrobial properties, was studied against food pathogens.Methods: The synthesis of silver (Ag) nanoparticles from the leaf extracts were monitored with the characterization of silver nanoparticles with the help of UV-visible spectrophotometer. The optimized time for the synthesis of nanoparticles was 3 h, followed by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), surface emission microscopy analysis (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and energy dispersive spectroscopy analysis (EDX). The antioxidant activity was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power assay, while antifungal activity was performed against food pathogens by measuring the zone of inhibition values (ZOI).Results: The Ag nanoparticle produced, have an average particle size of 34 nm with a spherical shape, analyzed from the XRD studies, and size was confirmed with the SEM and TEM analysis. The FTIR analysis gave information about the possible compounds adsorbed on the surface of the Ag nanoparticles. The Ag nanoparticles had good reducing power than the standard and the IC50 value for Ag nanoparticles was 5 mg/ml, while the standard taken had an IC50 value of nearly 6-7 mg/ml. The fungal strain A. fumigates showed ZOI of 133% at 75 µl of concentration proving that Ag nanoparticles can act effectively against this strain when compared to other strains even at low concentrations.Conclusion: The produced Ag nanoparticles can be used for its therapeutic purposes and for large-scale synthesis in food industries for food preservation or packaging.Â

    Travel to extraterrestrial bodies over time: some exploratory analyses of mission data

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    This paper discusses data pertaining to space missions to astronomical bodies beyond earth. The analyses provide summarizing facts and graphs obtained by mining data about (1) missions launched by all countries that go to the moon and planets, and (2) Earth satellites obtained from a Union of Concerned Scientists (UCS) dataset and lists of publically available satellite data

    Thin-film fabrication for high pressure thermoelectric and electrical resistivity studies

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    Thermoelectric materials are of interest for application such as thermoelectric cooler in microprocessors and power generators in cars. High pressure plays an important role in understanding the changes in the figure of merit of thermoelectric thin films. To study the thermoelectric thin films a direct approach is to fabricate the thin film on the surface of a diamond anvil, so that the pressure dependence of structure and transport properties can be investigated easily. If we could successfully fabricate the electrical probes by depositing thin films, then it reduces the use of electrical wires as probes inside the diamond cell, as the wires are easily breakable at high pressure. We have study different Molybdenum (MO) electrode fabrication and methods to deposit thermoelectric thin films using sputtering deposition (physical vapor deposition)

    INSULIN SECRETAGOGUE EFFECT OF ROOTS OF RAVENALA MADAGASCARIENSIS SONN. - AN IN VITRO STUDY

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    Objective: The objective of this study was to establish the cytotoxicity profile and to evaluate the insulin secretagogue effect of ethanolic root extract of Ravenala madagascariensis Sonn. Methods: The cell viability of rat insulinoma 5F (RIN5F) cell lines over the treatment of plant extract was assessed by 3-(4,5-dimethyl-2-thiazolyl)- 2,5-diphenyltetrazolium bromide assay. The insulin-releasing effect was evaluated by insulin secretion assay over RIN5F cell lines by enzyme-linked immunosorbent assay. Results: The ethanolic extract of the roots of R. madagascariensis Sonn. showed negligible cytotoxicity at 20–40 μg/ml, and hence, concentrations up to 40 μg/ml were used in insulin secretion assay. The ethanolic root extract at 20 and 40 μg/ml significantly (p<0.05 compared to control) stimulated the insulin release in a dose-dependent manner even in the presence of glucose at lower and higher concentrations (5 and 10 mM). Conclusion: Thus, our results validate its traditional claim in the treatment of diabetes by stimulating the secretion of insulin, thereby suggesting a possible mechanism of its antidiabetic effect

    MANET Hidden and Exposed Terminal - Challenges and Survey

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    Mobile Adhoc Network (MANET)is a self organized wireless Network which was created to communicate among  the nodes without support of the any Infrastructure. While transmission of the packets between the nodes, many challenges the every nodes faces. One of the Major challenges is Hidden and Exposed nodes issues in the MANET. This causes the packet drop or packet failure while the transmitting the packets. Also which  reflects in degrades the throughput of the MANET and performance of the MANET nodes when the heavy traffic ,retransmission of the dropped packets delayed the communication. This article discussed about hidden and Exposed terminal problem and challenges in MANET and also dissimilar survey in MANET
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