Studies of the benzopyran class of selective COX-2 inhibitors using 3D-QSAR and molecular docking

Dharmendra K. Yadav,Saloni,Praveen Sharma,Sanjeev Misra,Harpreet Singh,Ricardo L. Mancera,김강,장청연,김미현,Horacio Pe´rez-Sa´nchez,최은화,수렌드라 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

The Gaussian-based 3D-QSAR studies for 58 selective COX-2 (cyclooxygenase-2) inhibitors belonging to benzopyran chemical class were performed. Partial least squares analysis produced statistically significant model with (R training 2 = 0.866) and predictability (Q training 2 = 0.66, Q test 2 = 0.846). The 3D-QSAR model includes steric, electrostatic, hydrophobic, and hydrogen bond acceptor field indicators, whereas the potential field contributions indicate that the steric and hydrophobic features of the molecules play an important role in governing their biological activity. A molecular docking simulation and protein–ligand interaction pattern analysis reveal the importance of Tyr-361 and Ser-516 of the COX-2 active site for X-ray crystal structures and this class of molecules. Thus the combined approach of ligand-based and structure-based models provided an improved understanding in the interaction between benzopyran chemical class and COX-2 inhibition, which will guide the future identification of more potent anti-inflammatory drugs.

Pregnancy - associated human listeriosis: Virulence and genotypic analysis of Listeria monocytogenes from clinical samples

Dharmendra Kumar Soni,Durg Vijai Singh,Suresh Kumar Dubey 한국미생물학회 2015 The journal of microbiology Vol.53 No.9

cccListeria monocytogenes, a life-threatening pathogen, poses severe risk during pregnancy, may cause abortion, fetal death or neonatal morbidity in terms of septicemia and meningitis. The present study aimed at characterizing L. monocytogenes isolated from pregnant women based on serotyping, antibiotic susceptibility, virulence genes, in vivo pathogenicity test and ERIC- and REP-PCR fingerprint analyses. The results revealed that out of 3700 human clinical samples, a total of 30 (0.81%) isolates [12 (0.80%) from placental bit (1500), 18 (0.81%) from vaginal swab (2200)] were positive for L. monocytogenes. All the isolates belonged to serogroup 4b, and were + ve for virulence genes tested i.e. inlA, inlC, inlJ, plcA, prfA, actA, hlyA, and iap. Based on the mice inoculation tests, 20 isolates showed 100% and 4 isolates 60% relative virulence while 6 isolates were non-pathogenic. Moreover, 2 and 10 isolates were resistant to ciprofloxacin and cefoxitin, respectively, while the rest susceptible to other antibiotics used in this study. ERIC- and REP-PCR collectively depicted that the isolates from placental bit and vaginal swab had distinct PCR fingerprints except a few isolates with identical patterns. This study demonstrates prevalence of pathogenic strains mostly resistant to cefoxitin and/or ciprofloxacin. The results indicate the importance of isolating and characterizing the pathogen from human clinical samples as the pre-requisite for accurate epidemiological investigations. Listeria monocytogenes, a life-threatening pathogen, poses severe risk during pregnancy, may cause abortion, fetal death or neonatal morbidity in terms of septicemia and meningitis. The present study aimed at characterizing L. monocytogenes isolated from pregnant women based on serotyping, antibiotic susceptibility, virulence genes, in vivo pathogenicity test and ERIC- and REP-PCR fingerprint analyses. The results revealed that out of 3700 human clinical samples, a total of 30 (0.81%) isolates [12 (0.80%) from placental bit (1500), 18 (0.81%) from vaginal swab (2200)] were positive for L. monocytogenes. All the isolates belonged to serogroup 4b, and were + ve for virulence genes tested i.e. inlA, inlC, inlJ, plcA, prfA, actA, hlyA, and iap. Based on the mice inoculation tests, 20 isolates showed 100% and 4 isolates 60% relative virulence while 6 isolates were non-pathogenic. Moreover, 2 and 10 isolates were resistant to ciprofloxacin and cefoxitin, respectively, while the rest susceptible to other antibiotics used in this study. ERIC- and REP-PCR collectively depicted that the isolates from placental bit and vaginal swab had distinct PCR fingerprints except a few isolates with identical patterns. This study demonstrates prevalence of pathogenic strains mostly resistant to cefoxitin and/or ciprofloxacin. The results indicate the importance of isolating and characterizing the pathogen from human clinical samples as the pre-requisite for accurate epidemiological investigations.

Soil Diversity: A Key for Natural Management of Biological and Chemical Constitute to Maintain Soil Health & Fertility

Dharmendra Singh,Parul Jain,Abhishek Gupta,Rajeev Nema 보안공학연구지원센터 2013 International Journal of Bio-Science and Bio-Techn Vol.5 No.1

Effect of support on the catalytic activity of supported Ni–Fe catalysts for the CO2 methanation reaction

Dharmendra Pandey,Goutam Deo 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.33 No.-

Nickel and iron supported on Al2O3, ZrO2, TiO2 and SiO2 containing Ni and Fe in the ratio of 3:1 showed ahigher CH4 yield compared to the supported Ni catalysts. The Nb2O5 supported catalyst was anexception. The relative enhancement in yield for the most active catalyst of each series was supportdependent, and the maximum enhancement was achieved when Al2O3 was the support. It appeared thatthe enhancements in yield was due to formation of a suitable Ni–Fe alloy and the maximumenhancement for the Al2O3 supported catalysts was due to the ability of the support to adsorb CO2.

Resistance distance method for determination of isomorphism, stiffness and best input link among planar Kinematic chains

Dharmendra Singh,Aas Mohd,R. A. Khan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.1

The detection of isomorphism among kinematic chains and their derived mechanisms has been a hot area of research for the last severalyears. In this paper, a quantitative method (resistance distance method) is proposed in order to compare all the distinct chains withspecified number of links and degree of freedom, for rigidity of the chain and to select the best input link to introduce motion and to testisomorphism thoroughly and uniquely. In this method, the kinematic chains are represented in the form of resistance graph and from thatgraph a Laplacian matrix is generated which is further transformed into a resistance distance matrix.

Comparative Study of Microstructure and Texture of Cast and Homogenized TX32 Magnesium Alloy After Hot Deformation

C. Dharmendra,K. P. Rao,Y. V. R. K. Prasad,N. Hort,K. U. Kainer 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.1

The effect of homogenization on the hot deformation behavior and texture evolution of Mg-3Sn-2Ca (TX32)alloy is investigated. The cast-homogenized alloy samples were hot compressed in the temperature and strainrate ranges of 300-500 °C and 0.0003-10 s-1,respectively, and a processing map has been developed by using theflow stress data. The map revealed two dynamic recrystallization (DRX) domains with a peak efficiency of 44%at 360 °C/0.0003 s-1(Domain 1) and 43% at 485 ○C/0.1 s-1(Domain 2). When compared with the map for as-castcondition, it is observed that both the domains moved towards higher temperatures although the shift ofDomain 1 is more noticeable. The apparent activation energy values in the two domains and the regime of flowinstability are nearly unchanged by homogenization, suggesting that Mg2Ca and CaMgSn particles in themicrostructure are thermally stable. Specimens deformed under conditions in Domain 1 have high Schmid factorsfor {0001} <1120> basal slip and {1100} <1120> prismatic slip, while in Domain 2 the deformation progresseddue to {112 2} <112 3> second-order pyramidal slip.

Dielectric-Spectroscopic and ac Conductivity Investigations on Manganese Doped Layered Na_1.9Li_0.1Ti₃O₇ Ceramics

Pal, Dharmendra,Pandey, J.L.,Shripal Korean Chemical Society 2009 대한화학회지 Vol.53 No.1

유전율-분광법과 교류 전도도 측정 연구를 망간이 혼입된 층상구조의 $Na_{1.9}Li_{0.1}Ti_3O_7$에 시도하였다. 373-723K 온도와 100Hz-1MHz 주파수 영역에서 loss 탄젠트 (Tan$\delta$), 상대적 유전율 ($\varepsilon_{r}$) 그리고 교류 전도 도 ($\sigma_{ac}$)의 의존성을 혼입 유도체들에 대하여 조사하였다. 다양한 전도도 메커니즘이 존재하는데 MSLT-1과 MSLT-2의 경우에는 낮은 온도영역에서 전자에 의한 전도도를 보인다. MSLT-3의 경우에는 금지된 층간 이온 전 도도가 전자 전도도와 함께 존재한다. 이러한 층간 이온 전도도는 모든 혼입 유도체들에 대하여 중간 온도 영역에 존재한다. 가장 높은 온도 영역에서는 MSLT-1과 MSLT-2의 경우에는 이온 전도도와 polaron에 의한 전도도가 존재하고 MSLT-3에 대하여는 이온 전도도 만이 존재한다. 망간이 혼입된 층상구조의 $Na_{1.9}Li_{0.1}Ti_3O_7$에서 Loss 탄젠트 (Tan$\delta$)는 전자 전도도와 쌍극자의 위치, 그리고 공간 전하 분극화에 기인한다. 상대적 유전율의 증가는 층간 에 쌍극자 수의 증가에 기인하고 반면 상대적 유전율의 감소는 높은 혼입율에 따른 누전 전류의 증가에 기인한다. The dielectric-spectroscopic and ac conductivity studies firstly carried out on layered manganese doped Sodium Lithium Trititanates ($Na_{1.9}Li_{0.1}Ti_3O_7$). The dependence of loss tangent (Tan$\delta$), relative permittivity ($\varepsilon_r$) and ac conductivity ($\sigma_{ac}$) in temperature range 373-723K and frequency range 100Hz-1MHz studied on doped derivatives. Various conduction mechanisms are involved during temperature range of study like electronic hopping conduction in lowest temperature region, for MSLT-1 and MSLT-2. The hindered interlayer ionic conduction exists with electronic hopping conduction for MSLT-3. The associated interlayer ionic conduction exists in mid temperature region for all doped derivatives. In highest temperature region modified interlayer ionic conduction along with the polaronic conduction, exist for MSLT-1, MSLT-2, and only modified interlayer ionic conduction for MSLT-3. The loss tangent (Tan$\delta$) in manganese-doped derivatives of layered $Na_{1.9}Li_{0.1}Ti_3O_7$ ceramic may be due to contribution of electric conduction, dipole orientation, and space charge polarization. The corresponding increase in the values of relative permittivity may be due to increase in number of dipoles in the interlayer space while the corresponding decrease in the values of relative permittivity may be due to the increase in the leakage current due to the higher doping.

Comment on Leprosy Control in Korea

DR.Dharmendra 대한나학회 1967 대한나학회지 Vol.4 No.1

State of air pollutants and related health risk over Haryana India as viewed from satellite platform in COVID-19 lockdown scenario

Singh Dharmendra,Nanda Chintan,Dahiya Meenakshi 대한공간정보학회 2022 Spatial Information Research Vol.30 No.1

COVID-19 driven lockdown has affected air quality worldwide. Changes in air pollutants concentration, Air Quality Index (AQI), and associated Excess Health Risk (ER%) were assessed using satellite data of before (2019), and during (2020) COVID-19 periods in the industrially, agriculturally developed and highly populated area of Haryana in the northern region of Indo-Gangetic Plains. Parameters such as Aerosol Optical Depth (AOD), Particulate matters (PM), Sulphur Di-Oxide (SO2), Nitrogen Di-Oxide (NO2), Carbon Mono-oxide (CO), and Methane (CH4) were derived using satellite data and validated using ground-based observations (n = 23). The coefficient of correlation (r) 0.91, 0.90, 0.95, 0.73, 0.81 and 0.80 were established with AOD, PM2.5, PM10, SO2, NO2 and CO, respectively. Significant reduction (p\0.005) in the concentration of air pollutants, viz. 38% in AOD, 55% in PM2.5, 61% in PM10, 31% in SO2, 10% in NO2, 5% in CO and 1% in CH4 were observed during lockdown. Significant (p\0.00) improvement in air quality was observed due to a 44% reduction in pollution level, which led to the reduction in ER% by 71%, which is quite significant. AQI and ER% from satellite and ground showed a high r2 i.e. 0.88 and 0.99 respectively, suggesting the potential application of satellite data for periodic AQI and ER% assessment.

Roles of RECQ helicases in recombination based DNA repair, genomic stability and aging.

Singh, Dharmendra Kumar,Ahn, Byungchan,Bohr, Vilhelm A Kluwer Academic Publishers 2009 Biogerontology Vol.10 No.3

<P>The maintenance of the stability of genetic material is an essential feature of every living organism. Organisms across all kingdoms have evolved diverse and highly efficient repair mechanisms to protect the genome from deleterious consequences of various genotoxic factors that might tend to destabilize the integrity of the genome in each generation. One such group of proteins that is actively involved in genome surveillance is the RecQ helicase family. These proteins are highly conserved DNA helicases, which have diverse roles in multiple DNA metabolic processes such as DNA replication, recombination and DNA repair. In humans, five RecQ helicases have been identified and three of them namely, WRN, BLM and RecQL4 have been linked to genetic diseases characterized by genome instability, premature aging and cancer predisposition. This helicase family plays important roles in various DNA repair pathways including protecting the genome from illegitimate recombination during chromosome segregation in mitosis and assuring genome stability. This review mainly focuses on various roles of human RecQ helicases in the process of recombination-based DNA repair to maintain genome stability and physiological consequences of their defects in the development of cancer and premature aging.</P>