Dihydroxylated 2,6-diphenyl-4-chlorophenylpyridines: Topoisomerase I and IIα dual inhibitors with DNA non-intercalative catalytic activity

Bist, Ganesh,Park, Seojeong,Song, Chanju,Thapa Magar, Til Bahadur,Shrestha, Aarajana,Kwon, Youngjoo,Lee, Eung-Seok S.E.C.T. [etc.] 2017 European journal of medicinal chemistry Vol.133 No.-

<P><B>Abstract</B></P> <P>With the aim to develop novel antiproliferative agents, a new series of eighteen dihydroxylated 2,6-diphenyl-4-chlorophenylpyridines were systematically designed, prepared, and investigated for their topoisomerase (topo) I and IIα inhibitory properties and antiproliferative effect in three different human cancer cell lines (HCT15, T47D, and HeLa). Compounds <B>22–30</B> which possess a <I>meta</I>- or <I>para</I>-phenol on 2-, or 6-position of central pyridine ring showed significant dual topo I and topo IIα inhibitory activities with strong antiproliferative activities against all the tested human cancer cell lines. However, compounds <B>13</B>–<B>21</B> which possess an <I>ortho</I>-phenol on 2-, or 6-position of central pyridine ring did not show significant topo I and topo IIα inhibitory activities but displayed moderate antiproliferative activities against all the tested human cancer cell lines. Compound <B>23</B> exhibited the highest antiproliferative potency as much as 348.5 and 105 times compared to etoposide and camptothecin, respectively, in T47D cancer cell line. The structure-activity relationship study revealed that the <I>para</I> position of a hydroxyl group at 2-and 6-phenyl ring and chlorine atom at the <I>para</I> position of 4-phenyl ring of the central pyridine exhibited the most significant topo I and topo IIα inhibition, which might indicate introduction of the chlorine atom at the phenyl ring of 4-pyridine have an important role as dual inhibitors of topo I and topo IIα. Compound <B>30</B> which showed the most potent dual topo I and topo IIα inhibition with strong antiproliferative activity in T47D cell line was selected to perform further study on the mechanism of action, which revealed that compound <B>30</B> functions as a potent DNA non-intercalative catalytic topo I and IIα dual inhibitor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Dihydroxylated 2,6-diphenyl-4-chlorophenylpyridines were designed and synthesized. </LI> <LI> Introduction of chlorine on 4-phenyl ring of central pyridine showed strong dual topo I and IIα inhibitor. </LI> <LI> Compound <B>30</B> exhibited the most potent dual topo I and IIα inhibition with strong antiproliferative activity. </LI> <LI> Compound <B>30</B> acts as a DNA non-intercalative catalytic topo IIα inhibitor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

The Effect of Religious Hazards in Health among Menstrual Women

Bimal Singh Bist 서울대학교 보건환경연구소 2014 보건학논집 Vol.51 No.2

Improved Power Quality IHQRR-BIFRED Converter Fed BLDC Motor Drive

Singh, Bhim,Bist, Vashist The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

This paper presents an IHQRR (Integrated High Quality Rectifier Regulator) BIFRED (Boost Integrated Flyback Rectifier Energy Storage DC-DC) converter fed BLDC (Brushless DC) motor drive. A reduced sensor topology is derived by utilizing a BIFRED converter to operate in a dual DCM (Discontinuous Conduction Mode) thus utilizing a voltage follower approach for the PFC (Power Factor Correction) and voltage control. A new approach for speed control is proposed using a single voltage sensor. The speed of the BLDC motor drive is controlled by varying the DC link voltage of the front end converter. Moreover, fundamental frequency switching of the VSI's (Voltage Source Inverter) switches is used for the electronic commutation of the BLDC motor which reduces the switching losses in the VSI. The proposed drive is designed for a wide range of speed control with an improved power quality at the AC mains which falls within the recommended limits imposed by international power quality standards such as IEC 61000-3-2.

Age-Related Maturation of Wave V Latency of Auditory Brainstem Response in Children

Mukesh Sharma,Sampan Singh Bist,Santosh Kumar 대한청각학회 2016 Journal of Audiology & Otology Vol.20 No.2

Background and Objectives: Auditory brainstem response (ABR) is a noninvasive measurement of a stimulus-locked, synchronous electrical event. ABR provides information concerning the functional integrity of brainstem nuclei. Age is a key factor in the interpretation of ABR peak latency among different age groups. Progressively with time it follows a “maturation pattern” during which latencies decrease. Wave V is very prominent and reliable for detection of threshold in children. The present study was performed to see the effect of age related auditory maturation on ABR wave V latency in children. Subjects and Methods: The study involved 80 subjects ranging in age from birth to 12 years. The subjects were divided equally into eight age groups. ABR were elicited by an acoustic click stimuli, brainstem responses collected through electrode and recorded at the same time. Latency of wave V was acknowledged. Results: Wave V latency decreased rapidly in early childhood, became slower after 3 years of age and completely matured by 12 years of age. There was no significant difference in latency of wave V between the ears with age. Conclusions: There is a distinct maturation pattern of wave V latency in ABR for both ears. ABR is a reliable test to assess the functional maturation of wave V in children.

Financial development, openness in financial services trade and economic growth

Rabia Khatun,Jagadish Prasad Bist 경희대학교 글로벌 통상·금융연구원 2019 International Trade, Politics and Development Vol.3 No.2

The purpose of this paper is to examine the relationship between financial development, openness in financial services trade and economic growth in BRICS countries for the period 1990–2012.An index for financial development has been constructed using principal component analysis technique by including banking sector development, stock market development, bond market development and insurance sector development. For the robustness of the result, the long-run cointegrating relationship amongst the variables has been analyzed.Overall financial development has a positive and significant impact on economic growth. To take the full advantage of openness in financial services trade, countries need to put more emphasis on the development of their stock markets, bond markets and the insurance sector. The result shows that openness in financial services trade has a positive impact on economic growth when the stock market, bond market and insurance sector are included in the system.The policy implication of the findings is that policymakers should focus more on developing all four areas of finance to get the full benefit of the financial system on the process of economic growth.The authors have constructed the better indicators of financial development in the case of BRICS economies. Most of the studies in BRICS economies have measured the development of the financial sector as either banking sector development or stock market development. However, the present study includes all four areas of finance (banking sector development, stock market development, insurance sector development and bond market development) into account.

Improved Power Quality IHQRR-BIFRED Converter Fed BLDC Motor Drive

Bhim Singh,Vashist Bist 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

This paper presents an IHQRR (Integrated High Quality Rectifier Regulator) BIFRED (Boost Integrated Flyback Rectifier Energy Storage DC-DC) converter fed BLDC (Brushless DC) motor drive. A reduced sensor topology is derived by utilizing a BIFRED converter to operate in a dual DCM (Discontinuous Conduction Mode) thus utilizing a voltage follower approach for the PFC(Power Factor Correction) and voltage control. A new approach for speed control is proposed using a single voltage sensor. The speed of the BLDC motor drive is controlled by varying the DC link voltage of the front end converter. Moreover, fundamental frequency switching of the VSI’s (Voltage Source Inverter) switches is used for the electronic commutation of the BLDC motor which reduces the switching losses in the VSI. The proposed drive is designed for a wide range of speed control with an improved power quality at the AC mains which falls within the recommended limits imposed by international power quality standards such as IEC 61000-3-2.

In Silico Computational Method for ACP classification and Peptide Class validation Server in Bioinformatics

Sadik Bhattarai,Prem Singh Bist,Hilal Tayara,Kil To Chomg 계명대학교 생활과학연구소 2023 科學論集 Vol.48 No.-

Music Onset Detection Using Convolutional Neural Network

Yagya Raj Pandey,Prem Singh Bist 한국디지털융합학회 2019 IJICTDC Vol.4 No.1

Onset detection is a primary task in audio processing for any higher-level audio processing such as music information retrieval or automatic speech recognition. Onset detection using data driven approach is hard due to labeled data scarcity. In this work we use some in build dataset for training our convolutional neural network (CNN) work and make some test data for Nepalese traditional music. The CNN with raw waveform of input audio signal performs well in this study for onset detection. This network performs well in diversified audio type where 50 millisecond windows are set in each audio file to identify the presence or absence of onset.

Photocatalytic and photoelectrochemical water oxidation over metal-doped monoclinic BiVO(4) photoanodes.

Parmar, Kanak Pal Singh,Kang, Hyun Joon,Bist, Amita,Dua, Piyush,Jang, Jum Suk,Lee, Jae Sung Wiley-VCH 2012 ChemSusChem Vol.5 No.10

<P>The visible-light-induced water oxidation ability of metal-ion-doped BiVO(4) was investigated and of 12 metal ion dopants tested, only W and Mo dramatically enhanced the water photo-oxidation activity of bare BiVO(4); Mo had the highest improvement by a factor of about six. Thus, BiVO(4) and W- or Mo-doped (2 atom %) BiVO(4) photoanodes about 1 μm thick were fabricated onto transparent conducting substrate by a metal-organic decomposition/spin-coating method. Under simulated one sun (air mass 1.5G, 100 mW cm(-2)) and at 1.23 V versus a reversible hydrogen electrode, the highest photocurrent density (J(PH)) of about 2.38 mA cm(-2) was achieved for Mo doping followed by W doping (J(PH) ? 1.98 mA cm(-2)), whereas undoped BiVO(4) gave a J(PH) value of about 0.42 mA cm(-2). The photoelectrochemical water oxidation activity of W- and Mo-doped BiVO(4) photoanodes corresponded to the incident photon to current conversion efficiency of about 35 and 40 % respectively. Electrochemical impedance spectroscopy and Mott-Schottky analysis indicated a positive flat band shift of about 30 mV, a carrier concentration 1.6-2 times higher, and a charge-transfer resistance reduced by 3-4-fold for W- or Mo-doped BiVO(4) relative to undoped BiVO(4). Electronic structure calculations revealed that both W and Mo were shallow donors and Mo doping generated superior conductivity to W doping. The photo-oxidation activity of water on BiVO(4) photoanodes (undoped<W doped<Mo doped) was in accordance with the results from electrochemical impedance spectroscopy, Mott-Schottky analysis, and theoretical electronic structural calculations. Thus, Mo or W doping enhanced the photocatalytic and photoelectrochemical water oxidation activity of monoclinic BiVO(4) by drastically reducing its charge-transfer resistance and thereby minimizing photoexcited electron-hole pair recombination.</P>

Synthesis and biological evaluation of pyridine-linked indanone derivatives: Potential agents for inflammatory bowel disease

Kadayat, Tara Man,Banskota, Suhrid,Bist, Ganesh,Gurung, Pallavi,Magar, Til Bahadur Thapa,Shrestha, Aarajana,Kim, Jung-Ae,Lee, Eung-Seok Elsevier 2018 Bioorganic & medicinal chemistry letters Vol.28 No.14

<P><B>Abstract</B></P> <P>A series of pyridine-linked indanone derivatives were designed and synthesized to discover new small molecules for the treatment of inflammatory bowel disease (IBD). Compounds <B>5b</B> and <B>5d</B> exhibited strongest inhibitory activity against TNF-α-induced monocyte adhesion to colon epithelial cells (an <I>in vitro</I> model of colitis). In TNBS (2,4,6-trinitrobenzenesulfonic acid)-induced rat colitis model, oral administration of the compounds <B>5b</B> and <B>5d</B> ameliorated colitis with significant recovery in altered expressions of E-cadherin, TNF-α and IL-1β expressions, indicating <B>5b</B> and <B>5d</B> as potential agents for therapeutics development against IBD.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Synthesis of pyridine-linked indanone derivatives <B>2</B>, <B>5a–l</B>, <B>8a–c</B> and <B>11a–c</B>. </LI> <LI> Potent anti-inflammatory effect by compounds <B>2</B>, <B>5a</B>, <B>5b</B>, <B>5d</B>, <B>5f</B>, and <B>5h</B>. </LI> <LI> Hydroxyl group substitution is favorable but alkoxy groups at indanone ring is less favored. </LI> <LI> <B>5b</B> and <B>5d</B> as potential agents for inflammatory bowel disease. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>