Relative toxicity of different combinations of temephos and fenthion with Solanum xanthocarpum extract against anopheline larvae

Lalit Mohan,Preeti Sharma,Shrankhla,Chand Narayan SRIVASTAVA 한국곤충학회 2013 Entomological Research Vol.43 No.4

The relative toxicity of different concentrations of temephos and fenthion with petroleum ether root extract of Solanum xanthocarpum (Schrader) at 1 : 1, 1 : 2 and 1 : 4 ratios was evaluated against Anopheles stephensi (Liston) larvae. All combinations exhibited antagonism at concentrations lower than LC50 values and synergism at concentrations higher than their LC90 values. A 1 : 1 product ratio was the most effective.

Prospective role of insecticides of fungal origin: Review

Chand Narayan SRIVASTAVA,Prejwltta MAURYA,Preeti SHARMA,Lalit MOHAN 한국곤충학회 2009 Entomological Research Vol.39 No.6

Advances in the application of microbial-based technology in insect pest management assist us to counter problems created by the application of chemical pesticides. These are mainly strong environmental effects, resistance development and high costs. Among the microbial pesticides, fungal pesticides are now preferred as they are target specific, ecofriendly, lacking in toxic residue and are economical. Being numerous with great diversification, entomopathogenic fungi therefore have great potential to control a large variety of insect pests. Fungi are applied directly in form of spores, mycelia or blastospores or by their metabolites (mycotoxins). Both approaches have very promising roles in insect pest management. However, there are three main obstacles in the development of fungal pesticides: (i) scant production of mycotoxins; (ii) carcinogenic mycotoxicosis in non-target organisms; and (iii) slow effectiveness. Therefore, to eliminate these problems, attention has recently been paid to a synergistic approach to combating insecticide resistance. Next to synergism, genetic manipulation is also used to enhance the pathogenicity and virulence of fungal insecticides. However, the key risk associated with the release of recombinant microorganisms into the environment is that the novel organism may have unforeseen undesirable characteristics. Therefore, the introduction of synergists in pest control could have great benefit both economically and ecologically. An ideal synergistic approach is the mixing of more than two accelerating components together, i.e. tripartite or multiple synergism to enhance effectiveness. Thus, synergistic approaches have a bright future and require further research and financial support.

Effect of thickness variation of hole injection and hole blocking layers on the performance of fluorescent green organic light emitting diodes

K. Narayan,S. Varadharajaperumal,G. Mohan Rao,M. Manoj Varma,T. Srinivas 한국물리학회 2013 Current Applied Physics Vol.13 No.1

In this paper we present the effect of thickness variation of hole injection and hole blocking layers on the performance of fluorescent green organic light emitting diodes (OLEDs). A number of OLED devices have been fabricated with combinations of hole injecting and hole blocking layers of varying thicknesses. Even though hole blocking and hole injection layers have opposite functions, yet there is a particular combination of their thicknesses when they function in conjunction and luminous efficiency and power efficiency are maximized. The optimum thickness of CuPc (Copper(II) phthalocyanine) layer, used as hole injection layer and BCP (2,9 dimethyl-4,7-diphenyl-1,10-phenanthroline) used as hole blocking layer were found to be 18 nm and 10 nm respectively. It is with this delicate adjustment of thicknesses, charge balancing is achieved and luminous efficiency and power efficiency were optimized. The maximum luminous efficiency of 3.82 cd/A at a current density of 24.45 mA/cm2 and maximum power efficiency of 2.61 lm/W at a current density of 5.3 mA/cm2 were achieved. We obtained luminance of 5993 cd/m2 when current density was 140 mA/cm2. The EL spectra was obtained for the LEDs and found that it has a peaking at 524 nm of wavelength.

Larvicidal activity of Pseudocalymma alliaceum and Allium sativum against Culex quinquefasciatus (Say)

Shrankhla,Preeti Sharma,Lalit Mohan,Chand Narayan SRIVASTAVA 한국곤충학회 2011 Entomological Research Vol.41 No.6

The larvicidal activity of the plant extracts Pseudocalymma alliaceum and Allium sativum were determined against Culex quinquefasciatus. The hexane extract of P. alliaceum and the petroleum ether extract of A. sativum exhibited larvicidal efficacy against Cx. quinquefasciatus larvae. Extracts of P. alliaceum resulted in concentrations that produced 50% mortality LC_50 and LC_90 values of 2.49 and 15.06 ppm, respectively, after 24 h and 1.16 and 8.45 ppm after 48 h. Extracts of A. sativum resulted in LC_50 and LC_90 values of 8.38 and 29.15 ppm after 24 h and 7.28 and 44.19 ppm after 48 h of exposure, respectively. The results indicate that the plant extract component(s) present in the hexane extract of P. alliaceum leaves demonstrated greater potential as an efficient larvicide than A. sativum against Cx. quinquefasciatus.

Predictions of thermodynamic properties of pure fluids, refrigerants, and binary mixtures using modified Peng-Robinson equation of state

Pradnya Nirmala Prabhakar Ghoderao,Mohan Narayan,Vishwanath Haily Dalvi,변헌수 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.12

The Peng-Robinson (PR) EOS is a very successful two-parameter equation of state to estimate thermodynamicproperties of pure compounds as well as mixtures. The PR EOS has been modified and revised several ways toimprove estimates, and the most popular modification is for the attractive term through alpha function and temperaturedependent covolume parameter in the repulsive term. However, the unphysical, i.e., negative values of temperaturedependent co volume parameter at high temperature lead to undesirable results. We have addressed this issue inthe present work by incorporating a temperature dependent covolume parameter and yet physically consistent over alarge range of temperature. In the present work, the Modified-Peng-Robinson 2 (MPR2) equation of state is presentedby modifying the alpha function in attractive term and temperature dependent co-volume parameter in repulsive termof the PR EOS. The accuracy of MPR2 EOS is demonstrated by comparing results with the PR, HKM1, and MPR1equations of state. The thermodynamic properties, namely saturated vapor pressure and liquid density, enthalpy ofvaporization, compressed liquid densities in sub and supercritical region, heat capacities (isobaric and isochoric), andsound velocity of pure compounds, are predicted by MPR2 EOS which agrees very well with the experimental data. We have further studied 24 refrigerant properties like vapor and liquid densities. The work has also been extended tostudy the phase behavior of 26 binary mixtures using van der Waals single fluid mixing rules.

GSTT1 null and MPO -463G>A Polymorphisms and Carboplatin Toxicity in an Indian Population

Bag, Arundhati,Pant, Nirdosh Kumar,Jeena, Lalit Mohan,Bag, Niladri,Jyala, Narayan Singh Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.8

Carboplatin, a second generation platinum drug, is widely used to treat different types of cancers. However, myelosuppression remains a major consideration in its use. Genetic polymorphisms of enzymes involved in drug disposition can influence therapeutic outcome. The homozygous null deletion of phase II metabolic gene GSTT1 that abolishes its xenobiotic- detoxifying ability may be associated with carboplatin toxicity. Further, since carboplatin generates oxidative stress, polymorphisms of oxidative stress genes that regulate the cellular level of free radicals may have important roles in generating drug- related adverse effects. We here investigated the null polymorphism of GSTT1, and the -463G>A promoter polymorphism of oxidative stress gene myeloperoxidase (MPO) for carboplatin toxicity in a population of northern India. Cancer patients who were treated with carboplatin, and developed toxicity was considered. The study group comprised of 10 patients who developed therapy- related adverse effects. Peripheral blood was taken from patients for DNA isolation. GSTT1 null genotype was determined by conducting duplex PCR and MPO-463 G>A was determined by PCR followed by RFLP. Hematologic toxicity was experienced by 5 patients, 2 of them had grade 3 and 4 toxicity and 3 others had grade 2 toxicity. They also had gastrointestinal (GI) toxicity. Remaining 5 individuals developed GI toxicity but no hematological toxicity. While GG homozygous of MPO was present in majority of patients having hematologic toxicity (in 4 out of 5 individuals), one A allele (AG genotype) was present in 4 patients who did not have any hematological toxicity. Thus variant A allele of MPO -463G>A may be related to lower hematological toxicity. These preliminary data, however, are required to be confirmed in larger studies along with other relevant polymorphisms.