Nanotechnology is a new and emerging technology with wealth of applications. It involves the synthesis and application of materials having one of the dimensions in the range of 1–100 nm. A wide ...variety of physico–chemical approaches are being used these days for the synthesis of nanoparticles (NPs). However, biogenic reduction of metal precursors to produce corresponding NPs is eco-friendly, less expensive, free of chemical contaminants for medical and biological applications where purity of NPs is of major concern. Biogenic reduction is a “Bottom Up” approach similar to chemical reduction where a reducing agent is replaced by extract of a natural products with inherent stabilizing, growth terminating and capping properties. Furthermore, the nature of biological entities in different concentrations in combination with reducing organic agents influence the size and shape of NPs. Present review focuses on microbes or plants based green synthesis of Ag, Au, Cu, Fe, Pd, Ru, PbS, CdS, CuO, CeO₂, Fe₃O₄, TiO₂, and ZnO NPs and their potential applications.
Cyanobacteria are prominent inhabitants of many agricultural soils, where they potentially contribute towards biological nitrogen fixation, help in phosphate solubilization and mineral release to ...improve soil fertility and crop productivity. However, beside naturally fertilizing and balancing mineral nutrition in the soil, many cyanobacteria are known to release various kinds of biologically active substances like proteins, vitamins, carbohydrates, amino acids, polysaccharides and phytohormones that function as elicitor molecules to promote plant growth and help them to fight against biotic and abiotic stress. These metabolites produced by the cyanobacteria affect the gene expression of the host plants and thereby bring about qualitative and quantitative changes in the phytochemical composition of the plants. Experiments carried out with live inoculum or with the extracts of cyanobacterial strains on several plant species, such as rice, wheat, maize, cotton etc., have demonstrated the synthesis of signalling metabolites. Thus, in view of its beneficial effect, this paper reviews the role of cyanobacteria in triggering the growth and development of plants and hence its utilization in agriculture.
The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum ...reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
A newly hybrid nature inspired algorithm called HPSOGWO is presented with the combination of Particle Swarm Optimization (PSO) and Grey Wolf Optimizer (GWO). The main idea is to improve the ability ...of exploitation in Particle Swarm Optimization with the ability of exploration in Grey Wolf Optimizer to produce both variants’ strength. Some unimodal, multimodal, and fixed-dimension multimodal test functions are used to check the solution quality and performance of HPSOGWO variant. The numerical and statistical solutions show that the hybrid variant outperforms significantly the PSO and GWO variants in terms of solution quality, solution stability, convergence speed, and ability to find the global optimum.
Natural changes in climate due to internal as well as external factors, like anthropogenic emission, fossil fuel combustion, transportation and heating which cause CO2 emissions is one of the major ...issues which causes global warming (increasing concentrations of greenhouse gases). The production of algae is identified as one of the solutions of carbon sequestration along with production of renewable fuel solving the problem of food crisis to a certain extent. This review paper summarizes how CO2 levels affected micro algal species. Several species of algae as Scenedesmus obliquus, Botryococcus braunii, Chlorella vulgaris, Nannochloropsis oculata have been reported to accumulate high concentration of lipid. These species are suitable for biofuel production as well as Carbon fixation.
Aerosol emissions from biomass burning are of specific interest over the globe due to their strong radiative impacts and climate implications. The present study examines the impact of paddy crop ...residue burning over northern India during the postmonsoon (October–November) season of 2012 on modification of aerosol properties, as well as the long‐range transport of smoke plumes, altitude characteristics, and affected areas via the synergy of ground‐based measurements and satellite observations. During this period, Moderate Resolution Imaging Spectroradiometer (MODIS) images show a thick smoke/hazy aerosol layer below 2–2.5 km in the atmosphere covering nearly the whole Indo‐Gangetic Plains (IGP). The air mass trajectories originating from the biomass‐burning source region over Punjab at 500 m reveal a potential aerosol transport pathway along the Ganges valley from west to east, resulting in a strong aerosol optical depth (AOD) gradient. Sometimes, depending upon the wind direction and meteorological conditions, the plumes also influence central India, the Arabian Sea, and the Bay of Bengal, thus contributing to Asian pollution outflow. The increased number of fire counts (Terra and Aqua MODIS data) is associated with severe aerosol‐laden atmospheres (AOD500 nm > 1.0) over six IGP locations, high values of Ångström exponent (>1.2), high particulate mass 2.5 (PM2.5) concentrations (>100–150 µgm−3), and enhanced Ozone Monitoring Instrument Aerosol Index gradient (~2.5) and NO2 concentrations (~6 × 1015 mol/cm2), indicating the dominance of smoke aerosols from agricultural crop residue burning. The aerosol size distribution is shifted toward the fine‐mode fraction, also exhibiting an increase in the radius of fine aerosols due to coagulation processes in a highly turbid environment. The spectral variation of the single‐scattering albedo reveals enhanced dominance of moderately absorbing aerosols, while the aerosol properties, modification, and mixing atmospheric processes differentiate along the IGP sites depending on the distance from the aerosol source, urban influence, and local characteristics.
Key Points
Satellite and ground‐based monitoring of agriculture fires in northern India
Transport pathways, smoke plume characteristics, and affected areas
Variation of aerosol loading as a function of distance from the source
IntroductionFactitious hematemesis is the bleeding type of Munchausen’s syndrome together with dual diagnosis of school refusal is rarely reported in the literature. It is a condition in which the ...patient intentionally produces symptoms to assume a sick role and gain medical attention. Underdiagnosis of this disorder results in the unnecessary use of medical resources, i.e. unnecessary medical tests and evaluations.ObjectivescaseWe present this rare case of a patient with chronic factitious disorder who presented to the emergency with hematemesis. The 12 year old male patient grade 6 student presented with curious history of hematemesis just before the entrance of school and in the new school premises since 2 years resulting in school refusal and multiple doctor shopping. The patient underwent laboratory tests (such as the examination of sputum specimens, urinalysis, complete blood evaluations) and diagnostic studies (fiberoptic bronchoscopy with bronchoalveolar lavage, computerized tomography and radiography of the chest, bronchial arteriography, endocopic studies etc), because he continually presented with hematemesis, in order to spot and discover the nature of the bleeding. Since such examinations failed (a few of them-namely fiberoptic bronchoscopies--were even performed when he was coughing up blood) and psychiatric consultations revealed the presence of psychologically traumatic events in the patient’s history which could explain the psychopathic traits of her personality (in fact she was aggressive and unstable in interpersonal relations), a diagnosis of factitious hematemesis in Munchausen’s syndrome was made.MethodsThe typical characteristics that should prompt the physician to include Munchausen syndrome in the diagnosis include deliberately lying, repeatedly coming to the clinic/hospital with similar complaints in a short span of time, taking excessive drugs (especially insulin and warfarin) to induce side-effects, recurrent abdominal pain, scars on limbs, and rheumatologic and hematological disorders.ResultsWe recommend that physicians all across the globe should report more cases of Munchausen syndrome. More research is required in this arena to understand the cultural, social, and psychological aspects of Munchausen syndrome and to find out which treatment strategy can be most beneficial for such patientsConclusionsMunchausen syndrome is a diagnostic dilemma that needs to be given adequate medical and social attention by encouraging further research and spreading awareness not only amongst the general population but also health care providers. With proper evaluation, diagnosis, and psychotherapy, the disease will not remain a diagnostic dilemma and would be easier to control and treat. This case report will contribute towards the awareness of physicians about Munchausen syndrome and the strategies to diagnose and treat it.Disclosure of InterestNone Declared
The growing demand for non-ferrous metals (Aluminium, Copper, Nickle, Lead and Zinc) has grown the non-ferrous metallurgical industry, which generate huge amount of solid waste. Most common method ...for the disposal of these solid wastes is dumping at sites, which pollutes the soil and water and covers the useful land. Geopolymerization technique can be very helpful for the safe disposal of these solid wastes, which converts the solid wastes into valuable construction materials such as binders, mortar, bricks, paving blocks and concrete etc. However, to commercialize the use of these construction products, some key aspects require detailed examination. Alternative techniques and materials will have to be identified to increase their reactivity in geopolymerization and in-depth knowledge of reaction mechanism, mix design, strength and durability characteristics of resulting geopolymer will have to be studied. The present paper reviews the important studies on geopolymerization of different solid wastes produced from non-ferrous industry. The optimum synthesis parameters such as alkali activators, curing temperature, curing time and molar ratio etc. for the geopolymerization of these solid wastes are reported and exiting gaps and future trends are also discussed.
•Different solid wastes produced from non-ferrous industry have been reviewed.•Optimum synthesis parameters for geopolymerization of solid wastes are reported.•Valued construction materials can be obtained by geopolymerization of solid wastes.•Key barriers in geopolymerization are processing methods & activators availability.•Future research required on properties of resultant geopolymer from solid wastes.
The introductory aspect of this review starts with a prologue on bioimaging in general and optical imaging in particular, and finally focuses on the most recently explored red and near infrared (NIR) ...emitting persistent luminescence nanoparticles (PLNPs) for bioimaging applications. Accordingly, a pre-requisite towards a better understanding of the subject makes it vital to talk about persistent luminescence, and the developments in red and NIR emitting persistent phosphors. In this context, different synthesis techniques to design nanoparticles and chemically modified (surface modification) nanostructures have also been summarized. Finally, the use of these nanostructures as bioimaging and targeting probes, both for
in vitro
and
in vivo
studies, in diverse frameworks, has been reviewed in detail. The significant findings suggest that, Mn
2+
and/or Cr
3+
doped nanostructures, particularly gallogermanates, are able to give an intense red-near infrared persistent emission with a longer afterglow time for more than 2 weeks and are suitable for bio-imaging applications. The review also talks about the remaining challenges, new dimensions and future course of research in this field.
Schematic representation of the different processes in persistent luminescence: charging (1), stimulation (2), discharging (3) (PET-persistent energy transfer, QT-quantum tunneling).
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