Analytical Modelling and Simulation Analysis of Junctionless Nanotube (JL NT) MOSFET

Raj Kumar,Raj Kumar,Arvind Kumar 한국전기전자재료학회 2022 Transactions on Electrical and Electronic Material Vol.23 No.4

In this paper, an analytical model for junctionless nanotube (JLNT) MOSFET has been developed. The analytical model for minimum central potential, threshold voltage and drain current has been developed by using variable separation method. These model expressions are further applied to analyse the Short Channel Effects (SCEs) of JL NT MOSFET. The electrical performance of proposed device has been investigated by varying different process parameters such as silicon nanotube thickness, gate oxide thickness, and gate length. All the results of developed models have been validated by comparing with so obtained simulated results from genius 3D device simulator of VisualTCAD for different device parameters. JLNT MOSFET with appropriate design parameters can be further explored for circuit applications.

Synthesis, Antioxidant and Molecular Docking Studies of (-)-Catechin Derivatives

Kumar, Deepak,Kumar, Raj,Ramajayam, R.,Lee, Keun Woo,Shin, Dong-Soo Korean Chemical Society 2021 대한화학회지 Vol.65 No.2

12 kinds of (-)-catechin derivatives were designed and synthesized. The catechin derivatives were evaluated their antioxidant activities using DPPH method. Most of them showed good antioxidant activity, particularly compounds 1d, 1e and 1j exhibited more activity than butylated hydroxytoluene (BHT). Molecular docking studies for compounds 1d, 1e and 1j with STAT1 showed not only sufficent characteristics binding cavity but also agreement with the observed biological activity. Acording to docking results, the compounds showed greater than hydrogen bonding, hydrophobic interactions, electrostatic interactions, and Van der Waals interactions as compared to the reference compound. They formed hydrogen bonds with important residues such as Lys566, His568, Leu570, and Phe644. The compounds showed a novel hydrogen bonding interaction with Arg649, which was not reported previously. Our results might suggest the compounds could serve as a novel anti-oxidant agent.

Novel phyto-derivative BRM270 inhibits hepatocellular carcinoma cells proliferation by inducing G2/M phase cell cycle arrest and apoptosis in xenograft mice model

Kumar Mongre, Raj,Sharma, Neelesh,Singh Sodhi, Simrinder,Ghosh, Mrinmoy,Kumar Singh, Amit,Kim, Nameun,Park, Yang Ho,Shin, Young Gyu,Kim, Sung Jin,Jiao Jiao, Zhang,Huynh, Do Luong,Jeong, Dong Kee EDITIONS SCIENTIFIQUES ELSEVIER 2017 BIOMEDICINE AND PHARMACOTHERAPY Vol.87 No.-

<P><B>Abstract</B></P> <P>Hepatocellular carcinoma (HCC) is a major threat to human health worldwide and development of novel antineoplastic drug is demanding task. BRM270 is a proprietary combination of traditional medicinal herbs, has been shown to be effective against a wide range of stem-like cancer initiating cells (SLCICs). However, the underlying mechanism and antitumor efficacy of BRM270 in human hepatocellular carcinoma (HCC) cells have not been well elucidated till date. Here we studied the tumoricidal effect of BRM270 on human-CD133<SUP>+</SUP> expressing stem-like HepG-2 and SNU-398 cells. Gene expression profiling by qPCR and specific cellular protein expressions was measured using immunocytochemistry/western blot analysis. <I>In vivo</I> efficacy of BRM270 has been elucidated in the SLCICs induced xenograft model. In addition, 2DG-(2-Deoxy-<SMALL>D</SMALL>-Glucose) optical-probe guided tumor monitoring was performed to delineate the size and extent of metastasized tumor. Significant (<I>P</I> <I><</I> 0.05) induction of Annexin-V positive cell population and dose-dependent upregulation of caspase-3 confirmed apoptotic cell death by pre/late apoptosis. In addition, bright field and fluorescence microscopy of treated cells revealed apoptotic morphology and DNA fragmentation in Hoechst33342 staining. Levels of c-Myc, Bcl-2 and c-Jun as invasive potential apoptotic marker were detected using qPCR/Western blot. Moreover, BRM270 significantly (<I>P</I> <I><</I> 0.05) increased survival rate that observed by Kaplan-Meier log rank test. In conclusion, these results indicate that BRM270 can effectively inhibit proliferation and induce apoptosis in hepatoma cells by down-regulating CyclinD1/Bcl2 mediated c-Jun apoptotic pathway.</P>

Development of ciclopirox nail lacquer with enhanced permeation and retention

( Raj Kumar Thapa ),( Ju Yeon Choi ),( Toe Gyung Go ),( Min Hyung Kang ),( Sang Duk Han ),( Joon Ho Jun ),( Mi Won Son ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2016 영남대학교 약품개발연구소 연구업적집 Vol.26 No.-

Onychomycosis is a prevailing disease caused by fungal infection of nails that mostly affects athletes and the elderly. Ciclopirox is approved by the US Food and Drug Administration for the topical treatment of ony-chomycosis. However, the desired penetration of ciclopirox into the nail bed has not been achieved via topical appli-cation for efficient treatment. Therefore, the main aim of this study was to enhance ciclopirox permeation and retention in nail by the development of a new nail lacquer formulation. We screened the effects of different solvents, alkalizing agents, and permeation enhancers on the per-meation of bovine hooves by ciclopirox and its retention in human nail clippings. The results suggest that isopropyl alcohol, potassium hydroxide, and urea as the solvent, alkalizing agent, and permeation enhancer, respectively, improved the permeation of the ciclopirox nail lacquer formulation the most with high flux rates. Comparison of the final formulation and marketed product revealed enhanced retention of ciclopirox from our developed for-mulation in human nail clippings. Therefore, our newly developed nail lacquer may be a potentially effective for-mulation for the treatment of onychomycosis in humans.

Ionic liquid assisted recovery of cobalt and nickel metals from spent lithium-ion batteries (LIBs)

( Raj Tirath ),( Raj Morya ),( Ashutosh Kumar Pandey ),( Sang-hyoun Kim ) 한국폐기물자원순환학회 2022 ISSE 초록집 Vol.2022 No.-

Lithium-ion batteries (LIBs) have become an essential component of the energy supply chain for transportation (in electric vehicles) and renewable energy storage systems. This surge in demand necessitates an increase in production, which, in turn, results in a large number of waste LIBs. LIB cathode material primarily contains heavy metal elements such as nickel (Ni) and cobalt (Co), which are potentially hazardous to human health and the environment if discarded improperly. The leaching of Co and Ni into various water streams has become an environmental hazard and is continuously affecting human health through the food chain. Thus, recycling spent LIBs has gotten a lot of attention because it provides a cost-effective way to ensure a steady supply of these metals for LIB remanufacturing. Thus, recycling spent LIBs has received a lot of attention because it offers a cost-effective way to ensure a steady supply of these metals for LIB remanufacturing while also encouraging safer environmental load reduction. Solvent extraction is the most widely accepted method for separating these metals, but traditional extractants employed in conjunction with molecular diluents often lack selectivity and cause major environmental hurdles. Thus, the present study demonstrated a state-of-the-art approach for the recovery of cobalt and nickel from waste LIBs using green ionic liquids, which is such as recycling from a sustainable perspective. Ionic liquids are molten salts of organic cation and inorganic/ organic anion and are considered as green solvents. Here in, two halogen-free, low viscous, biocompatible fatty acid-based hydrophobic ionic liquids (ILs) were synthesized, characterized, and used to recover cobalt, Co(II), and nickel, Ni(II), from aqueous solutions. The extraction behaviors of Co(II) and Ni(II) were studied further by varying the equilibrium time, ILs molar concentration, metal loading, and temperature. Thermodynamic parameters such as enthalpy change and Gibbs free energy change were also investigated showed that metal recovery is governed by metal transfer phenomenon. Study revealed that fatty acid-based ILs were found to be capable of extracting > 99 % Co(II) and Ni(II) from aqueous solutions at 298 K in 15 minutes using a 1:1 (org: aq.) ratio at low concentrations of 2.5 to 10 g L^-1. Furthermore, when the metal concentration was greater than 10 g L^-1, Co(II) extraction was preferred over Ni(II) extraction for methyltrioctylammonium oleate IL.

Analysis and optimization of drug solubility to improve pharmacokinetics

Raj Kumar Thapa,최한곤,용철순,김종오 한국약제학회 2017 Journal of Pharmaceutical Investigation Vol.47 No.2

Solubility measurement is one of the key elements that need to be considered in drug discovery and development process. Hence, its appropriate analysis and optimization is necessary to enhance the drug’s pharmacokinetic and therapeutic effects. In this article, different methods used for solubility analysis and optimization such as shake flask, potentiometric, turbidimetric, computational, miniature device and high throughput automated methods have been summarized. Additionally, the effect of solubility optimization methods (physical, chemical and carrier technology modifications) on pharmacokinetic enhancement has also been elucidated. New fast, feasible and automated methods of solubility analysis are necessary for its accurate measurement as well as for minimization of errors posed by traditional methods. Among the physical, chemical and carrier modification methods; higher potential is exhibited by nanoparticulate drug delivery carriers for optimization of drug solubility and enhancement of pharmacokinetics. Based on the drug characteristics and delivery requirement, appropriate method can be chosen for efficient solubility and pharmacokinetics enhancement of lipophilic drugs, especially of BCS class II and class IV.

ON HARMONIC CONVOLUTIONS INVOLVING A VERTICAL STRIP MAPPING

Kumar, Raj,Gupta, Sushma,Singh, Sukhjit,Dorff, Michael Korean Mathematical Society 2015 대한수학회보 Vol.52 No.1

Let $f_{\beta}=h_{\beta}+\bar{g}_{\beta}$ and $F_a=H_a+\bar{G}_a$ be harmonic mappings obtained by shearing of analytic mappings $h_{\beta}+g_{\beta}=1/(2isin{\beta})log\((1+ze^{i{\beta}})/(1+ze^{-i{\beta}})\)$, 0 < ${\beta}$ < ${\pi}$ and $H_a+G_a=z/(1-z)$, respectively. Kumar et al. [7] conjectured that if ${\omega}(z)=e^{i{\theta}}z^n({\theta}{\in}\mathbb{R},n{\in}\mathbb{N})$ and ${\omega}_a(z)=(a-z)/(1-az)$, $a{\in}(-1,1)$ are dilatations of $f_{\beta}$ and $F_a$, respectively, then $F_a\tilde{\ast}f_{\beta}{\in}S^0_H$ and is convex in the direction of the real axis, provided $a{\in}[(n-2)/(n+2),1)$. They claimed to have verified the result for n = 1, 2, 3 and 4 only. In the present paper, we settle the above conjecture, in the affirmative, for ${\beta}={\pi}/2$ and for all $n{\in}\mathbb{N}$.

In vitro antioxidant and free radical scavenging activities of stem extract of Euphorbia trigona Miller

Raj Kumar Salar,Pooja Sharma,Sukhvinder Singh Purewal 셀메드 세포교정의약학회 2015 TANG Vol.5 No.2

Antioxidative and free radical scavenging properties of different stem extracts of Euphorbia trigona were evaluated and correlated with its total phenolic content. Aqueous, acetone and methanolic extracts of shade dried stem were obtained and were concentrated in vacuo. The antioxidant and free radical scavenging activities of stem extracts was determined by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, reducing power assay, deoxyribose degradation assay and Fe2+chelating assay. Total phenolic contents (TPC) were evaluated using Folin-Ciocalteu reagent. The results confirmed that the plant is a rich source of polyphenolic compounds which are invariably higher compared to other herbs. All extracts showed TPC in the range of 146.6 – 168.6 mg/g gallic acid equivalents at 300 µg/ml of extract. Among the three extracts ME showed highest scavenging activity as evidenced by maximum scavenging of DPPH (83.2%), OH• radicals (94.81%), Fe2+chelating activity (88.59%) and a high reducing power 0.623 at 300 µg/ml. Our results demonstrate that Euphorbia trigona, an unexplored xerophytic plant could be potential source of natural antioxidants and phytotherapeutic agents. The plant possess invariably high amount of polyphenolic compounds with a broad spectrum of antioxidant properties and could be further used for food, feed and pharmaceutical applications.

Graphene oxide-wrapped PEGylated liquid crystalline nanoparticles for effective chemo-photothermal therapy of metastatic prostate cancer cells

( Raj Kumar Thapa ),( Yu Seok Youn ),( Jee Heon Jeong ),( Han Gon Choi ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2016 영남대학교 약품개발연구소 연구업적집 Vol.26 No.-

Here, we report the preparation of PEGylated liquid crystalline nanoparticles (LCN) loaded with docetaxel (DTX) and wrapped with grapheme oxide (GO), called PEG-GO/LCN/DTX, for effective chemo-photothermal therapy of metastatic prostate cancer cells. The prepared formulation exhibited a small particle size(<250 nm), high durg loading capacity(~15%), and efficient near infrared (NIR) light-induced thermal heat. Importantly, PEG-GO/LCN/DTX successfully accumulated in prostate cancer cells and exhib-ited potent apoptotic and actimigration effects, mediated by the combination of the anticancer effects of DTX and the thermal heat induced by exposure of GO to NIR light. Taken together, our findings sup-port that PEG-GO/LCN/DTX may be an effective system for treatment of metastatic prostate cancer. Moreover, the results establish a proof-of-concept for the potential chemo-photothermal functional-ity of PEG-GO/LCN/DTX. This hybrid system of LCN and GO could provide controlled and tatgeted drug delivery with enhanced NIR-induced thermal effects for effective treatment of metastatic cancers.

Receptor-targeted, drug-loaded, functionalized graphene oxides for chemotherapy and photothermal therapy

( Raj Kumar Thapa ),( Ju Yeon Choi ),( Bijay Kumar Poudel ),( Han Gon Choi ),( Chul Soon Yong ),( Jong Oh Kim ) 영남대학교 약품개발연구소 2016 영남대학교 약품개발연구소 연구업적집 Vol.26 No.-

Cancer is one of the leading causes of death worldwide. Although different chemotherapeutic agents have been developed to treat cancers, their use can be limited by low cellular uptake, drug resistance, and side effects. Hence, targeted drug delivery systems are continually being developed in order to improve the efficacy of chemotherapeutic agents. The main aim of this study was to prepare folic acid (F A)-conjugated polyvinyl pyrrolidone-functionalized graphene oxides (GO) (FA-GO) for targeted delivery of sorafenib (SF). GO were prepared using a modified Hummer``s method and subsequently altered to prepare FA-GO and SF-loaded FA-GO (FA-GO/SF). Characterization of GO derivatives was done using ultraviolet/ visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, atomic force microscopy, zeta potential measurements, and determination of in vitro drug release. Hemo-lytic toxicity, in vitro cytotoxicity, cellular uptake, and apoptotic effects of FA-GO/SF were also investigated. The results revealed that GO was successfully synthesized and that further transformation to FA-GO improved the stability and SF drug-loading capacity. In addition, the enhanced SF release under acidic conditions suggested possible benefits for cancer treatment. Conjugation of FA within the FA-GO/SF delivery system enabled targeted delivery of SF to cancer cells expressing high levels of FA receptors, thus increasing the cellular uptake and apoptotic effects of SF. Furthermore, the photothermal effect achieved by exposure of GO to near-infrared irradiation enhanced the anticancer effects ofF A-GO/SF. Taken together, FA-GO/SF is a potential carrier for targeted delivery of chemotherapeutic agents in cancer.