Empirical evaluation of coresets for L1- regression

by Ashish DwivediM.Tech

Instabilities granular media with flexible boundaries

by Debayan BhattacharyaPh.D

Prefetching in hybrid main memory systems

by Subisha VM.Tech

Design of a hybrid fuel burner coupled to a diesel reforming system for energy recovery from waste gas of fuel cell

by Dhanurdhar RamswamyM.Tech

Methanol stream reforming on plate reactor over catalyst surface supported by copper metal foam

by Piyush AgrawalM.Tech

Investigation of nanoparticle immobilized cellulase: nanoparticle identity, linker length and polyphenol hydrolysis

Cellulase containing nanobiocatalysts have been useful as an extraction tool based on their ability to disrupt plant cell walls. In this work, we investigate the effect of nanoparticle composition and chemical linkage towards immobilized cellulase activity. Cellulase nanoconstructs have been prepared, characterized and compared for their loading efficiencies with standard assays and enzyme kinetics and correlate well with the cognate loading efficiencies. Application of the cellulase-immobilized nanoparticles on onion skins results in release of a distinctive composition of polyphenols. The aglycosidic form of quercetin is the dominant product of onion skin hydrolysis affected by cellulase nanobiocatalysts. Chitosan-coated iron oxide nanoparticles with APTES-conjugated cellulase are found to be most effective for polyphenol release and for transformation of glycosidic to aglycosidic form of quercetin. These results shed light on the activity of immobilized cellulase beyond their role in cell wall disruption and are important for the practical application of cellulase nanobiocatalysts.by Sanjay Kumar, Vinod Morya, Joshna Gadhavi, Anjani Vishnoi, Jaskaran Singh and Bhaskar Datt

Laterality of damage influences the relationship between impairment and arm use after stroke

Objectives:�To investigate whether the relationship between arm use and motor impairment post-stroke is influenced by the hemisphere of damage.�Methods:�Right-handed patients with unilateral left hemisphere damage (LHD) or right (RHD) (n=58; 28 LHD, 30 RHD) were recruited for this study. The Arm Motor Ability Test and Functional Impact Assessment were used to derive arm use patterns. The Fugl-Meyer motor assessment scale was used to quantify the level of motor impairment.�Results:�A significant interaction between patient group and impairment level was observed for contralesional, but not ipsilesional arm use. For lower impairment levels, contralesional (right arm for LHD and left arm for RHD) arm use was greater in LHD than RHD patients. In contrast, for greater levels of impairment, there were no arm use differences between the two patient groups.�Conclusions:�When motor impairment is significant, it overrides potential effects of stroke laterality on the patterns of arm use. However, a robust influence of hemisphere of damage on the patterns of arm use is evident at lower impairment levels. This may be attributed to previously described arm preference effects. These findings suggest adoption of distinct strategies for rehabilitation following left�versus�right hemisphere damage in right-handers, at least when the impairment is moderate to low. (JINS, 2019,�00, 1�9)by Goldy Yadav, Kathleen Y Haaland and Pratik K Muth

Preface to the microbubbles: exploring gas-liquid interfaces for biomedical applications special issue

by Mohan Edirisinghe and Sameer Dalv

Perfect proton selectivity in ion transport through two-dimensional crystals

Defect-free monolayers of graphene and hexagonal boron nitride are surprisingly permeable to thermal protons, despite being completely impenetrable to all gases. It remains untested whether small ions can permeate through the two-dimensional crystals. Here we show that mechanically exfoliated graphene and hexagonal boron nitride exhibit perfect Nernst selectivity such that only protons can permeate through, with no detectable flow of counterions. In the experiments, we use suspended monolayers that have few, if any, atomic-scale defects, as shown by gas permeation tests, and place them to separate reservoirs filled with hydrochloric acid solutions. Protons account for all the electrical current and chloride ions are blocked. This result corroborates the previous conclusion that thermal protons can pierce defect-free two-dimensional crystals. Besides the importance for theoretical developments, our results are also of interest for research on various separation technologies based on two-dimensional materials. Introduction Proton transport through two-dimensional (2D) crystals has recently been studied, both experimentally and theoretically1,2,3,4,5,6,7,8,9. As for the experiment, it was found that proton permeation through mechanically exfoliated crystals is thermally activated with energy barriers of ?0.8?eV for graphene and ?0.3?eV for monolayer hexagonal boron nitride (hBN)1. Further measurements using deuterons, nuclei of the hydrogen isotope deuterium, show that quantum oscillations raise the energy of incoming protons by 0.2?eV2. This correction yielded the total barriers of ?0.5?eV for monolayer hBN and ?1?eV for graphene. From a theoretical perspective, the latter value is notably lower (by at least 30% but typically a factor of 2) than that found in density-functional calculations for graphene3,4,5,6,7. To account for the difference, a recent theory suggests that graphene can be partially hydrogenated during the measurements, which makes its lattice slightly sparser; thus, making it more permeable to protons8,9. An alternative explanation put forward attributes the observed proton currents to atomic-scale lattice defects, including vacancies10,11. This was argued on the basis of ion-selectivity measurements using chemical-vapor-deposited (CVD) graphene11. Indeed, CVD graphene is known to possess a large density of atomic-scale defects that appear during growth12,13,14. Such defects are generally absent in mechanically exfoliated 2D crystals, which was proven conclusively in gas-leak experiments using the so-called nanoballoons15,16,17. Even a single angstrom-sized vacancy per micrometer-size area could be detected in those experiments16,17. Whereas it is plausible that vacancies and similar defects played a dominant role in experiments using CVD graphene10,11, extrapolation of those results to mechanically exfoliated 2D crystals is unjustifiable. To resolve the controversy, it is crucial to carry out similar ion-selectivity studies using mechanically exfoliated crystals with little or no defects1,2,15. Here we report ion-selectivity measurements using mechanically exfoliated graphene and hBN monolayers. The crystals are found to be perfectly selective with respect to protons. The latter can permeate through the 2D membranes, whereas even such small ions as chlorine are blocked. The results support the previous conclusion1 that transport of thermal protons through high-quality graphene and hBN occurs through their bulk and does not involve vacancies and other atomic-scale defects.by K. Gopinadhan et al

Defect-induced electronic states amplify the cellular toxicity of ZnO nanoparticles

Zinc oxide nanoparticles (ZnO NPs) are used in numerous applications, including sunscreens, cosmetics, textiles, and electrical devices. Increased consumer and occupational exposure to ZnO NPs potentially poses a risk for toxicity. While many studies have examined the toxicity of ZnO NPs, little is known regarding the toxicological impact of inherent defects arising from batch-to-batch variations. It was hypothesized that the presence of varying chemical defects in ZnO NPs will contribute to cellular toxicity in rat aortic endothelial cells (RAECs). Pristine and defected ZnO NPs (oxidized, reduced, and annealed) were prepared and assessed three major cellular outcomes; cytotoxicity/apoptosis, reactive oxygen species production and oxidative stress, and endoplasmic reticulum (ER) stress. ZnO NPs chemical defects were confirmed by X-ray photoelectron spectroscopy and photoluminescence. Increased toxicity was observed in defected ZnO NPs compared to the pristine NPs as measured by cell viability, ER stress, and glutathione redox potential. It was determined that ZnO NPs induced ER stress through the PERK pathway. Taken together, these results demonstrate a previously unrecognized contribution of chemical defects to the toxicity of ZnO NPs, which should be considered in the risk assessment of engineered nanomaterials.by Indushekhar Persaud, Achyut J. Raghavendra, Archini Paruthi, Nasser B. Alsaleh, Valerie C. Minarchick, James R. Roede, Ramakrishna Podila and Jared M. Brow