Effect of Electric Field on Energy States of Electrons in Spherical Parabolic Quantum Dots

Bose,C.,Chakraborty,C.,Sarkar,C. K. 대한전자공학회 1997 ICVC : International Conference on VLSI and CAD Vol.5 No.1

An attempt is made to estimate the electric field induced shifts in electronic states in a spherical quantum dot (QD) with an isotropic parabolic potential (PP) by using a perturbation method. The results, computed for GaAs QD, shows that the electric field lowers the energy levels. The field induced energy shift is found to be the same for all levels, and also larger far a larger dot.

Estimation of Bergsma’s covariance

Bose Arup,Kappara Divya,Bhattacharjee Madhuchhanda 한국통계학회 2023 Journal of the Korean Statistical Society Vol.52 No.4

Bergsma (A new correlation coefficient, its orthogonal decomposition and associated tests of independence, arXiv preprint arXiv:math/0604627, 2006) proposed a covariance ĸ(X , Y ) between random variables X and Y, and gave two estimates for it, based on n i.i.d. samples. He derived the asymptotic distributions of these estimates under the assumption of independence between X and Y. Our main focus is on the dependent case. This measure turns out to be same as the distance covariance (dCov) measure for multivariate X and Y, when we specialize to real-valued X and Y. We first derive several alternate expressions for ĸ, which are useful to understand the properties of ĸ and its estimates better. One of the alternate expressions for ĸ leads to a very intuitive third estimator of ĸ that is a nice function of four U-statistics. We establish the exact finite sample algebraic relation between the three estimates. This yields the relation between the bias of these estimators. In the dependent case, using the U statistics central limit theorem, it is easy to show that our estimate is asymptotic normal. The relation between the three estimates is then used to show that Bergsma’s two estimates have the same limit distribution in the dependent case. When X and Y are independent, the above limit is degenerate. With a higher scaling, the non-degenerate limit distribution of all three estimators is obtained using the theory of degenerate U-statistics and the above algebraic relations. In particular, the known asymptotic distribution results for the two estimates of Bergsma for the independent case follow. For specific parametric bivariate distributions, the value of ĸ can be derived in terms of the natural dependence parameters of these distributions. In particular, we derive the formula for ĸ when (X, Y) are distributed as Gumbel’s bivariate exponential. We bring out various aspects of these estimators through extensive simulations from several prominent bivariate distributions. In particular, we investigate the empirical relationship between \kappa and the dependence parameters, the distributional properties of the estimators, and the accuracy of these estimators. We also investigate the finite sample powers of these measures for testing independence, compare these among themselves, and with other well known such measures. Based on these exercises, the proposed estimator seems as good or better than its competitors both in terms of power and computing efficiency.

Importance of Hydrophilic Pretreatment in the Hydrothermal Growth of Amorphous Molybdenum Sulfide for Hydrogen Evolution Catalysis

Bose, Ranjith,Balasingam, Suresh Kannan,Shin, Seokhee,Jin, Zhenyu,Kwon, Do Hyun,Jun, Yongseok,Min, Yo-Sep American Chemical Society 2015 Langmuir Vol.31 No.18

<P>Amorphous molybdenum sulfide (MoS<SUB><I>x</I></SUB>) has been identified as an excellent catalyst for the hydrogen evolution reaction (HER). It is still a challenge to prepare amorphous MoS<SUB><I>x</I></SUB> as a more active and stable catalyst for the HER. Here the amorphous MoS<SUB><I>x</I></SUB> catalysts are prepared on carbon fiber paper (CFP) substrates at 200 °C by a simple hydrothermal method using molybdic acid and thioacetamide. Because the CFP is intrinsically hydrophobic due to its graphene-like carbon structure, two kinds of hydrophilic pretreatment methods [plasma pretreatment (PP) and electrochemical pretreatment (EP)] are investigated to convert the hydrophobic surface of the CFP to be hydrophilic prior to the hydrothermal growth of MoS<SUB><I>x</I></SUB>. In the HER catalysis, the MoS<SUB><I>x</I></SUB> catalysts grown on the pretreated CFPs reach a cathodic current density of 10 mA/cm<SUP>2</SUP> at a much lower overpotential of 231 mV on the MoS<SUB><I>x</I></SUB>/EP-CFP and 205 mV on the MoS<SUB><I>x</I></SUB>/PP-CFP, compared to a high overpotential of 290 mV on the MoS<SUB><I>x</I></SUB> of the nonpretreated CFP. Turnover frequency per site is also significantly improved when the MoS<SUB><I>x</I></SUB> are grown on the pretreated CFPs. However, the Tafel slopes of all amorphous MoS<SUB><I>x</I></SUB> catalysts are in the range of 46–50 mV/dec, suggesting the Volmer–Heyrovsky mechanism as a major pathway for the HER. In addition, regardless of the presence or absence of the pretreatment, the hydrothermally grown MoS<SUB><I>x</I></SUB> catalyst on CFP exhibits such excellent stability that the degradation of the cathodic current density is negligible after 1000 cycles in a stability test, possibly due to the relatively high growth temperature.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2015/langd5.2015.31.issue-18/acs.langmuir.5b00205/production/images/medium/la-2015-00205r_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/la5b00205'>ACS Electronic Supporting Info</A></P>

A note on the perimeter of fat objects

Bose, P.,Cheong, O.,Dujmovic, V. Elsevier 2011 Computational Geometry Vol.44 No.1

In this Note, we show that the size of the perimeter of (α,β)-covered objects is a linear function of the diameter. Specifically, for an (α,β)-covered object O, per(O)=<cdiam(O)αβsin<SUP>2</SUP>α, for a positive constant c. One easy consequence of the result is that every point on the boundary of such an object sees a constant fraction of the boundary. Locally γ-fat objects are a generalization of (α,β)-covered objects. We show that no such relationship between perimeter and diameter can hold for locally γ-fat objects.

Evaluation of <i>In Vitro</i> Anti-Inflammatory Activities and Protective Effect of Fermented Preparations of Rhizoma Atractylodis Macrocephalae on Intestinal Barrier Function against Lipopolysaccharide Insult

Bose, Shambhunath,Kim, Hojun Hindawi Publishing Corporation 2013 Evidence-based Complementary and Alternative Medic Vol.2013 No.-

<P>Lipopolysaccharide (LPS), a potent inducer of systemic inflammatory responses, is known to cause impairment of intestinal barrier function. Here, we evaluated the <I>in vitro</I> protective effect of an unfermented formulation of Rhizoma Atractylodis Macrocephalae (RAM), a traditional Chinese herbal medicine widely used in the treatment of many digestive and gastrointestinal disorders, and two fermented preparations of RAM, designated as FRAM-1 (prepared in Luria-Bertani broth) and FRAM-2 (prepared in glucose), on intestinal epithelial cells (IECs) against LPS insult. In general, fermented formulations, especially FRAM-2, but not unfermented RAM, exerted an appreciable protective effect on IECs against LPS-induced perturbation of membrane resistance and permeability. Both fermented formulations exhibited appreciable anti-inflammatory activities in terms of their ability to inhibit LPS-induced gene expression and induced production of a number of key inflammatory mediators and cytokines in RAW 264.7 macrophage cells. However, in most cases, FRAM-2 exhibited stronger anti-inflammatory effects than FRAM-1. Our findings also suggest that suppression of nuclear factor-<I><I>κ</I></I><I><I>β</I></I> (NF-<I><I>κ</I></I><I><I>β</I></I>) activity might be one of the possible mechanisms by which the fermented RAM exerts its anti-inflammatory effects. Collectively, our results highlight the benefits of using fermented products of RAM to protect against LPS-induced inflammatory insult and impairment in intestinal barrier function.</P>

Genetic Variability and Association of Yield Attributing Characters with Grain Yield in Deepwater Rice

Bose L. K.,Pradhan S. K.,Mohanty A.,Nagaraju M. The Korean Society of Crop Science 2005 Korean journal of crop science Vol.50 No.4

A study on genetic variability and association of yield attributing characters with grain yield was carried out using 35 deepwater rice genotypes. High genotypic co-efficient of variation (GCV) was observed for plot yield, $EBT/m^2$, plant height and days to $50\%$ flowering (DFF). For all the traits, estimates of the phenotypic co-efficient of variation (PCV) were higher than GCV, indicating presence of environmental influence. High heritability and genetic advance was observed for plot yield, $EBT/m^2$ and plant height. Plot yield had significant positive association with test weight, $EBT/m^2$ and DFF. However, test weight had the maximum direct effect on grain yield

Antioxidant and free radical scavenging activities of Cleome rutidosperma

Bose, Anindya,Mondal, Sumanta,Gupta, Jayanta Kumar,Ghosh, Tirtha,Debbhuti, Debabrata,Si, Sudam Kyung Hee Oriental Medicine Research Center 2008 Oriental pharmacy and experimental medicine Vol.8 No.2

The study was aimed at evaluating the antioxidant and free radical scavenging activities of ethanolic extract and its fractions of Cleome rutidosperma. The antioxidant activity, reducing power, total phenolic content, total flavonoid content, superoxide anion scavenging activity, nitric oxide anion scavenging activity, in vitro antilipid peroxidation activity and in vitro non-enzymatic hemoglobin glycosylation were studied. The results obtained in the study indicate that Cleome rutidosperma is a potential source of natural antioxidant. All the parameters were found to be concentration dependent and increased with increasing amounts of sample. Flavonoids, phenolic compound like tannins, terpenoids may be responsible for the antioxidant activity of the plant. Variation of solubility parameters in various models may be attributed to non-linearity of activity of ethanol extract fractions models. Further investigation on the isolation and identification of antioxidant component(s) in the plant may lead to chemical entities with potential for clinical use.

Carbon-based nanostructured materials and their composites as supercapacitor electrodes

Bose, Saswata,Kuila, Tapas,Mishra, Ananta Kumar,Rajasekar, R.,Kim, Nam Hoon,Lee, Joong Hee The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.3

<p>This critical review provides an overview of current research on carbon-based nanostructured materials and their composites for use as supercapacitor electrodes. Particular emphasis has been directed towards basic principles of supercapacitors and various factors affecting their performance. The focus of the review is the detailed discussion regarding the performance and stability of carbon-based materials and their composites. Pseudo-active species, such as, conducting polymer/metal oxide have been found to exhibit pseudo-capacitive behavior and carbon-based materials demonstrate electrical double layer capacitance. Carbon-based materials, such as, graphene, carbon nanotubes, and carbon nanofibers, provide high surface area for the deposition of conducting polymer/metal oxide that facilitates the efficient ion diffusion phenomenon and contribute towards higher specific capacitance of the carbon based composite materials with excellent cyclic stability. However, further scope of research still exists from the view point of developing high energy supercapacitor devices in a cost effective and simple way. This review will be of value to researchers and emerging scientists dealing with or interested in carbon chemistry.</p> <P>Graphic Abstract</P><P>This review provides a summary of on-going researches on carbon-based nanostructured materials and their composites along with a demonstration of their performance and stability for use as supercapacitor electrodes. <img src='http://pubs.rsc.org/ej/JM/2011/c1jm14468e/c1jm14468e-ga.gif'> </P>

Bioengineered stem cell membrane functionalized nanocarriers for therapeutic targeting of severe hindlimb ischemia

Bose, Rajendran JC.,Kim, Byoung Ju,Arai, Yoshie,Han, In-bo,Moon, James J.,Paulmurugan, Ramasamy,Park, Hansoo,Lee, Soo-Hong Elsevier 2018 Biomaterials Vol.185 No.-

<P><B>Abstract</B></P> <P>Bioengineering strategies to enhance the natural targeting function of nanocarriers would expand their therapeutic applications. Here, we designed bioengineered stem cell membrane-functionalized nanocarriers (BSMNCs) harboring C-X-C chemokine receptor type 4 (CXCR4) to achieve robust targeting and also to increase their retention time in ischemic tissue. Stem cell membrane coated nanocarrier (SMNCs) or poly (lactic-<I>co</I>-glycolic acid) (PLGA) nanocarriers (PNCs) and BSMNCs were prepared by functionalizing PNCs with human adipose-derived stem cells (hASCs) membranes and hASCs engineered to overexpress CXCR4-receptor, respectively. The functionalization of PNCs with stem cell membranes derived from hASCs significantly enhance the nanocarrier penetration across endothelial cell barrier compare to PNCs. In addition, stem cell membrane functionalization on PNCs also significantly decreased the nanoparticles uptake in J774 (murine) and THP (human) macrophages respectively from 84% to 76%–29% and 24%. Interestingly, BSMNCs showed much higher level of accumulation in ischemic tissue than SMNCs. Systemic retro-orbital injection of BSMNCs loaded with VEGF into mice with hindlimb ischemia resulted substantially enhancement of blood reperfusion, muscle repair, and limb salvage compared to animals treated with SMNCs loaded with similar concentration of VEGF. The reported strategy could be used to create biocompatible and custom-tailored biomimetic nanoparticles with various hybrid functionalities, which may overcome the limitations of current nanoparticle-based therapeutic and imaging platforms.</P>

Preparation of cationic lipid layered PLGA hybrid nanoparticles for gene delivery

Bose, R.J.C.,Ahn, J.C.,Yoshie, A.,Park, S.,Park, H.,Lee, S.H. Elsevier Science Publishers 2015 Journal of controlled release Vol.213 No.-