Gaurav Sharma

Bio: Gaurav Sharma is an academic researcher from Shenzhen University. The author has contributed to research in topics: Medicine & Photocatalysis. The author has an hindex of 82, co-authored 1244 publications receiving 31482 citations. Previous affiliations of Gaurav Sharma include Northeastern University & D. E. Shaw & Co..

GO/TiO2-Related Nanocomposites as Photocatalysts for Pollutant Removal in Wastewater Treatment

Abstract: Water pollution has been a prevalent issue globally for some time. Some pollutants are released into the water system without treatment, making the water not suitable for consumption. This problem may lead to more grave problems in the future including the destruction of the ecosystem along with the organisms inhabiting it, and illness and diseases endangering human health. Conventional methods have been implemented to remove hazardous pollutants such as dyes, heavy metals, and oil but are incapable of doing so due to economic restraints and the inability to degrade the pollutants, leading to secondary pollution. Photocatalysis is a more recently applied concept and is proven to be able to completely remove and degrade pollutants into simpler organic compounds. Titanium dioxide (TiO2) is a fine example of a photocatalyst owing to its cost-effectiveness and superb efficiency. However, issues such as the high recombination rate of photogenerated electrons along with positive holes while being only limited to UV irradiation need to be addressed. Carbonaceous materials such as graphene oxide (GO) can overcome such issues by reducing the recombination rate and providing a platform for adsorption accompanied by photocatalytic degradation of TiO2. The history and development of the synthesis of GO will be discussed, followed by the methods used for GO/TiO2 synthesis. The hybrid of GO/TiO2 as a photocatalyst has received some attention in the application of wastewater treatment due to its efficiency and it being environmentally benign. This review paper thereby aims to identify the origins of different pollutants followed by the sickness they may potentially inflict. Recent findings, including that GO/TiO2-related nanocomposites can remove pollutants from the water system, and on the photodegradation mechanism for pollutants including aromatic dyes, heavy metal and crude oil, will be briefly discussed in this review. Moreover, several crucial factors that affect the performance of photocatalysis in pollutant removal will be discussed as well. Therefore, this paper presents a critical review of recent achievements in the use of GO/TiO2-related nanocomposites and photocatalysis for removing various pollutants in wastewater treatment.

Co-Polarized [1-13C]Pyruvate and [1,3-13C2]Acetoacetate Provide a Simultaneous View of Cytosolic and Mitochondrial Redox in a Single Experiment.

Abstract: Cellular redox is intricately linked to energy production and normal cell function. Although the redox states of mitochondria and cytosol are connected by shuttle mechanisms, the redox state of mitochondria may differ from redox in the cytosol in response to stress. However, detecting these differences in functioning tissues is difficult. Here, we employed 13C magnetic resonance spectroscopy (MRS) and co-polarized [1-13C]pyruvate and [1,3-13C2]acetoacetate ([1,3-13C2]AcAc) to monitor production of hyperpolarized (HP) lactate and β-hydroxybutyrate as indicators of cytosolic and mitochondrial redox, respectively. Isolated rat hearts were examined under normoxic conditions, during low-flow ischemia, and after pretreatment with either aminooxyacetate (AOA) or rotenone. All interventions were associated with an increase in [Pi]/[ATP] measured by 31P NMR. In well-oxygenated untreated hearts, rapid conversion of HP [1-13C]pyruvate to [1-13C]lactate and [1,3-13C2]AcAc to [1,3-13C2]β-hydroxybutyrate ([1,3-13C2]β-HB) was readily detected. A significant increase in HP [1,3-13C2]β-HB but not [1-13C]lactate was observed in rotenone-treated and ischemic hearts, consistent with an increase in mitochondrial NADH but not cytosolic NADH. AOA treatments did not alter the productions of HP [1-13C]lactate or [1,3-13C2]β-HB. This study demonstrates that biomarkers of mitochondrial and cytosolic redox may be detected simultaneously in functioning tissues using co-polarized [1-13C]pyruvate and [1,3-13C2]AcAc and 13C MRS and that changes in mitochondrial redox may precede changes in cytosolic redox.

Analysis of misregistration induced color shifts in the superposition of periodic screens

Abstract: We present an analysis and model for evaluation of color shifts in halftone printing caused by inter-separation misregistration for periodic clustered dot halftones. Using a lattice framework, we present intuitive analysis that demonstrates conditions under which the average color is asymptotically invariant under inter-separation misregistration. Combining the framework with an analytic representation for the halftone dots, we develop a hybrid analytical-numerical model for quantitatively estimating color shifts as a function of inter-separation misregistration. The model is compared against experimental data for a xerographic printer.

Comparison of Clonidine and Dexmedetomidine as an Adjuvant to 0.5% Ropivacaine in Supraclavicular Brachial Plexus Block: A Prospective, Randomized, Double-blind and Controlled Study

Abstract: Background: Brachial plexus blockade is the cornerstone of regional anesthesia practice. This study was done to compare clonidine and dexmedetomidine as an adjuvant to 0.5% ropivacaine in supraclavicular brachial plexus block (SCB). Materials and methods: A prospective, randomized, double-blind study was done in 120 patients of American Society of Anaesthesiologist (ASA) grade I and II undergoing elective upper limb surgery under SCB. Patients were randomized into three groups. Group 1 (n = 40) received 30 ml of 0.5% ropivacaine, group 2 (n = 40) received 30 ml of 0.5% ropivacaine with 2 mg/kg clonidine, and group 3 (n = 40) received 30 ml of 0.5% ropivacaine with 1 mg/kg dexmedetomidine. Onset and recovery time of sensory and motor block, duration of analgesia and quality of block, hemodynamic variables, and level of sedation were studied in the three groups. Results: Sensory and motor block onset times were shorter in group 3 than in group 1 and 2 (p < 0.0001). Sensory and motor block durations and duration of analgesia were longer in group 3 than in groups 1 and 2 (p < 0.0001). Blood pressure and heart rate were lower in group 3 as compared to groups 1 and 2 (p < 0.0001). The number of patients achieving grade IV quality of block was higher in group 3 as compared to the other groups. Conclusion: Dexmedetomidine when added in SCB shortened the onset of sensory and motor block and enhances the duration of sensory and motor block and duration of analgesia without significant side effects.

Optimized Elliptic Curve Cryptography for wireless sensor networks

Abstract: Recent technical advances have made it possible to develop such devices, which are small in size, cheap and capable of wireless communication using radio interfaces and provide pervasive services to the user. Sensor networks are the extreme examples of such ubiquous and pervasive computer paradigm. The constraints imposed on the wireless sensor networks make it more prone to cost of computation. So, the major issue is to reduce the computation cost by implementing some optimization technique, so that the overall efficiency of the system increases without any loss of information. In this paper, we list out few optimization techniques that can be used in Elliptic Curve Cryptography for wireless sensor networks.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

SPAdes, a new genome assembly algorithm and its applications to single-cell sequencing ( 7th Annual SFAF Meeting, 2012)

Abstract: The lion's share of bacteria in various environments cannot be cloned in the laboratory and thus cannot be sequenced using existing technologies. A major goal of single-cell genomics is to complement gene-centric metagenomic data with whole-genome assemblies of uncultivated organisms. Assembly of single-cell data is challenging because of highly non-uniform read coverage as well as elevated levels of sequencing errors and chimeric reads. We describe SPAdes, a new assembler for both single-cell and standard (multicell) assembly, and demonstrate that it improves on the recently released E+V-SC assembler (specialized for single-cell data) and on popular assemblers Velvet and SoapDeNovo (for multicell data). SPAdes generates single-cell assemblies, providing information about genomes of uncultivatable bacteria that vastly exceeds what may be obtained via traditional metagenomics studies. SPAdes is available online ( http://bioinf.spbau.ru/spades ). It is distributed as open source software.