3,213 research outputs found

    ENVIRONMENTAL IMPLICATIONS AND APPLICATIONS OF NANOMATERIALS

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    Recent advances in material science and nanotechnology have given rise to a myriad of developments, while in the meantime call for research into the impacts of nanomaterials on the environment and human health. Although considerable progress has been made in the past decade concerning the behavior of nanomaterials in biological systems, such understanding is critically lacking with respect to the fate of nanomaterials in ecosystems. Accordingly, this dissertation addresses the interactions between nanomaterials and algae--the major constituent of the aquatic food chain (Part I, Chapter two), and exploits the physicochemistry of nanoscaled synthetic dendritic polymers for environmental applications, especially for water purification that is a focused theme of the entire dossier (Part II, Chapters two-five). This dissertation is organized as follows. Chapter one presents a general review of the physical/physicochemical properties, characterizations, implications--especially ecological implication, and applications of a host of most produced and studied nanomaterials. In addition, advances in environmental applications of nanomaterials are discussed. Chapter two examines algal responses to two major types of engineered nanomaterials - quantum dots and polystyrene. Inhibited photosynthetic activities of green algae are observed as a result of the physical adsorption of the nanomaterials. Chapter three elucidates the physicochemical properties of poly(amidoamine)-tris(hydroxymethyl)amidomethane- and amine-terminated dendrimers towards their applications in water remediation. Here, the capacities and mechanisms of the dendrimers in hosting cationic copper, anionic nitrate, polyaromatic phenanthrene, and the more heterogeneous humic acids are discussed. Based on the results of Chapter three, Chapter four presents a dendrimer-based novel optical scheme for improving the detection sensitivity and selectivity of environmental pollutants. Specifically, the surface plasmon resonance of a gold nanowire and the high hosting capacity of dendrimers are utilized for enhancing the detection limit of copper down to the nanomolar level. Chapter five exploits a promising use of dendrimers for the removal of potentially harmful discharged nanoparticles. Here fullerenols are used as a model nanomaterial, and their interactions with dendrimers of two different generations are studied using spectrophotometry and thermodynamics methods. Chapter six summarizes the key findings in this dissertation and presents future work that is stimulated by this Doctor of Philosophy (PhD) research

    Endocarditis Caused by Abiotrophia and Granulicatella Species

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    Endocarditis caused by Abiotrophia and Granulicatella species, formerly known as nutritionally variant streptococci (NVS) is rare. It is associated with increased complications such as heart failure, systemic emboli, valve replacement surgery, treatment failures and mortality. The diagnosis of these infections is challenging due to specific nutritional growth requirements although modern techniques such as 16S rRNA sequence analysis and Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) are particularly useful. Penicillin resistance among these organisms is a growing problem. Penicillin and gentamicin combination or alternatively Vancomycin alone are the recommended treatment options, however there is increasing data regarding susceptibilities to other antibiotics. Varying susceptibilities to antibiotics among different species of NVS needs to be studied further

    Fraud Detection using Machine Learning in the Mobile Payment Service

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    The transformation of payment mechanism from face-to-face transactions to non-face-to-face transactions has led to increased popularity of Internet Banking, credit card, online billing in the mobile phone itself and, hence, it is directly proportional to the advancement of smartphones in particular. However, the probability of any kind of anomalous payments increases and due to that the requirement of fraud detection arises. This paper provides the idea of the trend followed in the detection of fraud in online payment through mobile phone with the help of machine learning [1]

    Biodegradable Polymeric Substances Produced by a Marine Bacterium from a Surplus Stream of the Biodiesel Industry

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    Crude glycerol is generated as a by-product during transesterification process and during hydrolysis of fat in the soap-manufacturing process, and poses a problem for waste management. In the present approach, an efficient process was designed for simultaneous production of 0.2 g/L extracellular ε-polylysine and 64.6% (w/w) intracellular polyhydroxyalkanoate (PHA) in the same fermentation broth (1 L shake flask) utilizing Jatropha biodiesel waste residues as carbon rich source by marine bacterial strain (Bacillus licheniformis PL26), isolated from west coast of India. The synthesized ε-polylysine and polyhydroxyalkanoate PHA by Bacillus licheniformis PL26 was characterized by thermogravimetric analysis (TGA), differential scanning colorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and 1H Nuclear magnetic resonance spectroscopy (NMR). The PHA produced by Bacillus licheniformis was found to be poly-3-hydroxybutyrate-co-3-hydroxyvalerate (P3HB-co-3HV). The developed process needs to be statistically optimized further for gaining still better yield of both the products in an efficient manner

    Impact of diabetes mellitus on ventricular structure, arterial stiffness, and pulsatile hemodynamics in heart failure with preserved ejection fraction

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    Background-Heterogeneity in the underlying processes that contribute to heart failure with preserved ejection fraction (HFpEF) is increasingly recognized. Diabetes mellitus is a frequent comorbidity in HFpEF, but its impact on left ventricular and arterial structure and function in HFpEF is unknown. Methods and Results-Weassessed the impact of diabetesmellitus on left ventricular cellular and interstitial hypertrophy (assessedwith cardiacmagnetic resonance imaging, including T1mapping pregadolinium and postgadolinium administration), arterial stiffness (assessed with arterial tonometry), and pulsatile arterial hemodynamics (assessed with in-office pressure-flow analyses and 24-hour ambulatory monitoring) among 53 subjects with HFpEF (32 diabetic and 21 nondiabetic subjects). Despite few differences in clinical characteristics, diabetic subjects with HFpEF exhibited a markedly greater left ventricular mass index (78.1 [95% CI, 70.4-85.9] g versus 63.6 [95% CI, 55.8-71.3] g; P=0.0093) and indexed extracellular volume (23.6 [95% CI, 21.2-26.1] mL/m(2) versus 16.2 [95% CI, 13.1-19.4] mL/m(2); P=0.0008). Pronounced aortic stiffening was also observed in the diabetic group (carotid-femoral pulse wave velocity, 11.86 [95% CI, 10.4-13.1] m/s versus 8.8 [95% CI, 7.5-10.1] m/s; P=0.0027), with an adverse pulsatile hemodynamic profile characterized by increased oscillatory power (315 [95% CI, 258-373] mWversus 190 [95% CI, 144-236] mW; P=0.0007), aortic characteristic impedance (0.154 [95% CI, 0.124-0.183] mmHg/mL per second versus 0.096 [95% CI, 0.072-0.121] mm Hg/mL per second; P=0.0024), and forward (59.5 [95% CI, 52.8-66.1] mm Hg versus 40.1 [95% CI, 31.6-48.6] mm Hg; P=0.0010) and backward (19.6 [95% CI, 16.2-22.9] mm Hg versus 14.1 [95% CI, 10.9-17.3] mm Hg; P=0.0169) wave amplitude. Abnormal pulsatile hemodynamics were also evident in 24-hour ambulatory monitoring, despite the absence of significant differences in 24-hour systolic blood pressure between the groups. Conclusions-Diabetes mellitus is a key determinant of left ventricular remodeling, arterial stiffness, adverse pulsatile hemodynamics, and ventricular-arterial interactions in HFpEF

    Agonistic Association of Lepidoptera and Fungus in the Development of Leaf-spot Disease in High Altitude Mango and its Control

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    Plants are common prey for pests, though plants at high altitudes are less prone to diseases. However, our sample proved to be an exception, as disease in plants have become a major problem in North India, especially in old, crowded orchards where there is excessive shade .Mango, our test plant, is well adapted to tropical and subtropical climate. Here we considered the mechanism of disease initiation in the mango leaves by the entry of a fungal pathogen- Cercospora mangiferae, and its possible agonistic association with an insect of the Lepidoptera group, Procontarinia sp . Our aim is to suggest a pesticide to avert the entry and reduce the occurrence of the disease. The specimen, collected from a place called Jorolle (NH 88) near Sundernagar, is 10 kms away from the Beas-Sutlej confluence in the state of Himachal Pradesh, during the months of January-February, the temperature recorded was between 7-14°C. The environment in the vicinity of the mango orchard was dry, windy, and grimy and plagued by vehicular emissions. There were predominantly 2 kinds of leaf spots-a white and a brown spot. The spread of the disease started from the lower mature leaves to the upper younger leaves. Enormity of the infection was much greater in leaves having galls along their margins. The gall formation results due to the mechanical damage caused by the infection due to a midge fly (Procontarinia sp). The average diameter of galls ranged between 3-4mm. As affirmed earlier, the leaves with large number of galls are the primary  home for the fungus- Cercospora mangiferae where they reside in larger numbers. Although the mechanism of an agonistic association is obscure but the possibility of such an association cannot be ruled out completely; where the primary infection caused by the midge insect paves the way for secondary infection by the fungus. Our sole intention was to prevent occurrence of such an association, by inhibiting both the infections from occurring individually. Our test pesticide belonged to the Malathione group. Its main component is monocrotophos which interferes not only with the nerve impulse transmission of the insect but also damages the cell wall of the fungal pathogen thereby attending both the problems. The experiment was performed with different concentrations of pesticide and it was observed that at 43.5%w/w it was effective enough to prevent 100% germination. Our studies provide a conclusive result which suggests that if the pesticide, at the effective concentration is sprayed till run-off, the young tender leaves of Mangifera indica will be protected from both the midge insect as well as the fungal pathogen.Key words: Chausa, Langra, Dashehari, Leaf spot, Cercospora mangiferae, White spot, Brown Spot, Gall, Procontarinia sp., pesticide, Malathione, Hilcron, Monocrotophos Arup Kumar Mitra et al. Agonistic Association of Lepidoptera and Fungus in the Development of Leaf-spot Disease in High Altitude Mango and its Control.  J Phytol 2/7 (2010) 28-36

    Recent Advances in Research on Down Syndrome

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    Down syndrome (DS) or trisomy 21 is one of the most important genetic causes of mental retardation. Sincere and significant attempts have been made towards understanding the congenital diseases that affect DS patients. Better understanding of gene networks associated with such malformations will help to predict the complex genetic trait behind congenital disease in DS and will also provide the basis for tailored gene therapies that could begin to heal or prevent such malformation without the need to resort to invasive surgery. Further, susceptible mutation screening in women will also be helpful for both prenatal diagnosis of DS birth and assessing the risk of predisposition to Alzheimer’s disease and congenital heart disease. Stress condition and neurodegeneration are two important markers in Down syndrome patients and mtDNA variation can also be used as an important biomarker. It has been suggested that nutraceuticals which reduce reactive oxygen species (ROS) level may be used to treat trisomy 21 condition. As mitochondria play a crucial role in the regulation of free radicals, only a detail analysis will reveal the origin of phenotypic characteristics among trisomy 21 DS patients. On the other hand, several mechanisms are responsible for neurodegeneration as well as altered cognition. It includes impaired neurogenesis leading to hypocellularity in the cortex, hippocampus and cerebellum, altered dendritic morphology, altered synapses, increased inhibition and neurodegeneration. The new knowledge of the pathogenic mechanisms in DS individuals has been acquired from mouse model. These studies provide the basis for developing new drugs for clinical trials in DS individuals and to sustain the hope that some of these drugs will be useful in treating intellectual disability in DS individuals

    Association of inflammatory biomarkers with lung cancer in North Indian population

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    Background: Lung cancer is characterized by uncontrolled cell growth of the lung tissues. It is the leading cause of cancer-related deaths worldwide.Objectives: The study aimed to determine the circulating CRP, TNF-α, IL-6 and IL-8 levels in lung cancer and healthy control and also established association between these biomarkers with the smoking status as well as the stages of the disease.Methodology: 51 lung cancer patients and 51 healthy controls were enrolled in this case-control study. The serum levels of CRP, TNF-α, IL-6 and IL-8 were measured in lung cancer patients and healthy control groups.Results: The levels of serum CRP, TNF-α, IL-6 and IL-8 were significantly higher in lung cancer patients when compared with controls(P<0.0001). The levels of these biomarkers were also significantly higher in stage iii/iv as compared to stage i/ii(P<0.001). Significant difference in the levels of these biomarkers were also found in smoker and non-smoker lung cancer patients as compared to controls(P<0.001).Conclusion: CRP, TNF-α, IL-6 and IL-8 are the promising biomarkers in the identification of lung cancer patients. The study also supports the association of inflammatory markers to lung cancer risk. Hence these findings suggest the levels of these biomarkerscould be a useful tool for guiding the diagnosis of lung cancer.Keywords: Lung cancer, biomarker, inflammation, stage, smoking

    Microtubule-associated protein 1B: a neuronal binding partner for gigaxonin

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    Giant axonal neuropathy (GAN), an autosomal recessive disorder caused by mutations in GAN, is characterized cytopathologically by cytoskeletal abnormality. Based on its sequence, gigaxonin contains an NH2-terminal BTB domain followed by six kelch repeats, which are believed to be important for protein–protein interactions (Adams, J., R. Kelso, and L. Cooley. 2000. Trends Cell Biol. 10:17–24.). Here, we report the identification of a neuronal binding partner of gigaxonin. Results obtained from yeast two-hybrid screening, cotransfections, and coimmunoprecipitations demonstrate that gigaxonin binds directly to microtubule-associated protein (MAP)1B light chain (LC; MAP1B-LC), a protein involved in maintaining the integrity of cytoskeletal structures and promoting neuronal stability. Studies using double immunofluorescent microscopy and ultrastructural analysis revealed physiological colocalization of gigaxonin with MAP1B in neurons. Furthermore, in transfected cells the specific interaction of gigaxonin with MAP1B is shown to enhance the microtubule stability required for axonal transport over long distance. At least two different mutations identified in GAN patients (Bomont, P., L. Cavalier, F. Blondeau, C. Ben Hamida, S. Belal, M. Tazir, E. Demir, H. Topaloglu, R. Korinthenberg, B. Tuysuz, et al. 2000. Nat. Genet. 26:370–374.) lead to loss of gigaxonin–MAP1B-LC interaction. The devastating axonal degeneration and neuronal death found in GAN patients point to the importance of gigaxonin for neuronal survival. Our findings may provide important insights into the pathogenesis of neurodegenerative disorders related to cytoskeletal abnormalities
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