Evaluation of the toxicity of different phytoextracts of Ocimum basilicum against Anopheles stephensi and Culex quinquefasciatus

Prejwltta Maurya,Preeti Sharma,Lalit Mohan,Lata Batabyal,C.N. Srivastava 한국응용곤충학회 2009 Journal of Asia-Pacific Entomology Vol.12 No.2

The larvicidal effect of the crude carbon tetrachloride, methanol and petroleum ether leaf extracts of a widely grown medicinal plant, Ocimum basilicum, against Anopheles stephensi and Culex quinquefasciatus was evaluated. Petroleum ether extract was found to be the most effective against the larvae of both mosquitoes, with LC50 values of 8.29, 4.57; 87.68, 47.25 ppm and LC90 values of 10.06, 6.06; 129.32, 65.58 ppm against A. stephensi and C. quinquefasciatus being observed after 24 and 48 h of treatment, respectively. The efficacy of petroleum ether was followed by that of the carbon tetrachloride and methanol extracts, which had LC50 values of 268.61, 143.85; 446.61, 384.84 ppm and LC90 values of 641.23, 507.80; 923.60, 887.00 ppm against A. stephensi after 24 and 48 h, respectively, and LC50 values of 24.14, 17.02; 63.48, 53.77 ppm and LC90 values of 295.38, 204.23; 689.71, 388.87 ppm against C. quinquefasciatus after 24 and 48 h of treatment, respectively. These extracts are highly toxic against mosquito larvae from a range of species; therefore, they may be useful for the management of mosquito larvae to control vector borne diseases. The larvicidal effect of the crude carbon tetrachloride, methanol and petroleum ether leaf extracts of a widely grown medicinal plant, Ocimum basilicum, against Anopheles stephensi and Culex quinquefasciatus was evaluated. Petroleum ether extract was found to be the most effective against the larvae of both mosquitoes, with LC50 values of 8.29, 4.57; 87.68, 47.25 ppm and LC90 values of 10.06, 6.06; 129.32, 65.58 ppm against A. stephensi and C. quinquefasciatus being observed after 24 and 48 h of treatment, respectively. The efficacy of petroleum ether was followed by that of the carbon tetrachloride and methanol extracts, which had LC50 values of 268.61, 143.85; 446.61, 384.84 ppm and LC90 values of 641.23, 507.80; 923.60, 887.00 ppm against A. stephensi after 24 and 48 h, respectively, and LC50 values of 24.14, 17.02; 63.48, 53.77 ppm and LC90 values of 295.38, 204.23; 689.71, 388.87 ppm against C. quinquefasciatus after 24 and 48 h of treatment, respectively. These extracts are highly toxic against mosquito larvae from a range of species; therefore, they may be useful for the management of mosquito larvae to control vector borne diseases.

Light-Controlled Self-Assembly of Semiconductor Nanoparticles into Twisted Ribbons

Srivastava, S.,Santos, A.,Critchley, K.,Kim, K.-S.,Podsiadlo, P.,Sun, K.,Lee, J.,Xu, C.,Lilly, G. D.,Glotzer, S. C.,Kotov, N. A. American Association for the Advancement of Scienc 2010 Science Vol.327 No.5971

Synthesis, magnetic and Mossbauer spectroscopic studies of Cr doped lithium ferrite nanoparticles

Srivastava, M.,Layek, S.,Singh, J.,Das, A.K.,Verma, H.C.,Ojha, A.K.,Kim, N.H.,Lee, J.H. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.591 No.-

Lithium-based ferrites are promising and potential magnetic materials for microwave applications. They possess a spinel (AB<SUB>2</SUB>O<SUB>4</SUB>) type crystal structure, where the distributions of metal cations over the tetrahedral (A) and octahedral (B) voids play a crucial role for exhibiting different physical properties. Among various parameter of synthesis, pH is an important factor that influences the cation distribution over A and B voids, overall growth of the nanoparticles and different physical properties. In the present work single phase Cr substituted lithium ferrite nanoparticles have been synthesized by the sol-gel method at different pH. The phase identification and crystallite size have been probed by X-ray diffraction studies. The crystallite size changes by 44.2-48.8nm upon varying the pH from 3.5 to 11.5. In order to investigate the cations distribution at A/B sites, Mossbauer spectroscopic measurements were done. The values of magnetic hyperfine field obtained from the Mossbauer data for the A and B sites are ~49.5T and 51T, respectively. Moreover, it is observed that the area ratio of B site to A site increases with increasing the pH. This observation further suggests that the B site is more preferable for Fe<SUP>3+</SUP> cations at higher pH than the A site. The magnetic parameter such as saturation magnetization (M<SUB>s</SUB>), remanent magnetization (M<SUB>r</SUB>), coercive field (H<SUB>C</SUB>) and squareness (S) are determined by vibrating sample magnetometer (VSM) measurements, which show a consistent increase with increasing pH. The reason for the variation in magnetic properties has been explained on the basis of increased Fe<SUP>3+</SUP> cation occupancies at the B site and size effect, which is well supported by Mossbauer spectroscopic and XRD studies.

Growth Inhibitory Nature of Artemisia annua Extract against Culex quinquefasciatus (Say)

Preeti Sharma,Lalit Mohan,C.N. Srivastava 한국응용곤충학회 2006 Journal of Asia-Pacific Entomology Vol.9 No.4

Petroleum ether (Pee), carbon tetrachloride (Cte) and methanol extract (Mee) of Artemisia annua, Chenopodium album and Sonchus oleraceus were screened for their efficacy against Culex quinquefasciatus larvae. Pee of A. annua, Mee of A. annua and Ch. album, Cte of A. Annua were found effective in descending order after 24 and 48 hrs of treatment. Pee of A. annua, the most potent extract with LC50 78.2 ppm was selected to study its influence on the development and metamorphosis of the culicine mosquito. The extract significantly affected the hatching, larval development, pupal transformation and also lengthened the larval and pupal periods. Growth index was remarkably reduced. Treated culicine eggs, larvae and pupae showed deformities including disruption of the body wall, distorted alimentary canal, damaged tracheal network and arrested histogenesis. The extract has remarkable effect on the metamorphosis and high larvicidal potential, hence, can be used as an effective alternative to the existing synthetic pesticides for the control of Cx. quinquefasciatus.

Evaluation of Solanum xanthocarpum extract as a synergist for cypermethrin against larvae of the filarial vector Culex quinquefasciatus (Say)

Lalit MOHAN,Preeti SHARMA,C. N. SRIVASTAVA 한국곤충학회 2006 Entomological Research Vol.36 No.4

Cypermethrin and crude extracts of Solanum xanthocarpum were both observed fortheir larvicidal activity against Culex quinquefasciatus. Petroleum ether extract with lethal concentration (LC)50 and LC90 of 41.28 and 111.16 p.p.m. after 24 h and LC50 38.48 and LC90 80.83 p.p.m. after 48 h, respectively, was found to be the most effective, followed by carbon tetrachloride and methanol extracts. LC50 and LC90 for cypermethrin were 0.0027 and 0.0097 p.p.m. after 24 h and 0.0013 and 0.0092 p.p.m. after 48 h of exposure, respectively. Combined formulations were evaluated for synergistic activity and a 1:1 ratio of cypermethrin and petroleum ether extract was observed to be more effective than 1:2 and 1:4 ratios. Combinations of S. xanthocarpum extracts and cypermethrin demonstrated higher larvicidal activity, indicating synergistic activity. These results demonstrate the need for further studies on the effectiveness and toxicity to humans and animals, particularly aquatic forms.

Growth Inhibitory Nature of Artemisia annua Extract against Culex quinquefasciatus (Say)

Shaema, Preeti,Mohan, Lalit,Srivastava, C.N. Korean Society of Applied Entomology 2006 Journal of Asia-Pacific Entomology Vol.9 No.4

Petroleum ether (Pee), carbon tetrachloride (Cte) and methanol extract (Mee) of Artemisia anmua, Chenopodium album and Sonchus oleraceus were screened for their efficacy against Culex quinquefasciatus larvae. Pee of A. annua, Mee of A. annua and Ch. album, Cte of A. Annua were found effective in descending order after 24 and 48 hrs of treatment. Pee of A. annua, the most potent extract with $LC_{50}\;78.2\;ppm$ was selected to study its influence on the development and metamorphosis of the culicine mosquito. The extract significantly affected the hatching, larval development, pupal transformation and also lengthened the larval and pupal periods. Growth index was remarkably reduced. Treated culicine eggs, larvae and pupae showed deformities including disruption of the body wall, distorted alimentary canal, damaged tracheal network and arrested histogenesis. The extract has remarkable effect on the metamorphosis and high larvicidal potential, hence, can be used as an effective alternative to the existing synthetic pesticides for the control of Cx. quinquefasciatus.

Impact analysis of neem kernel extracts on the developmental profile of Anopheles stephensi

Preeti Sharma,Lalit Mohan,C.N. Srivastava 한국응용곤충학회 2006 Journal of Asia-Pacific Entomology Vol.9 No.1

evaluation of the larvicidal effi-cacy ofAgeratum conyzoides,Argemone mexicanaand Azadirachta indicawas carried out againstAno-pheles stephensito develop an effective ecofriendlyinsecticide of plant origin. The methanol extract ofA. indicawas observed remarkably active with LC50values 18.2 and 13.1 ppm after 24 and 48 hours ofexposure. Petroleum ether extracts ofAg. conyzoideswith LC50 425.6 and 267.9 pm, carbon tetra chlo-ride extract ofAr. mexicanawith LC50 313.2 and240.3 ppm and petroleum ether extract ofAz. indicawith LC50 189.1 and 53. 5 ppm after 24 and 48hours of exposure were also found effective. Theimpact of Az.indica methanol extract on the lifecycle of malaria vector was further observed. Me-thanol extract of Az.indica causes deformities indifferent developmental stages of the malaria vector.Total developmental period was also extended from10 to 15 It remarkably influenced hatching rates,larval-pupal transformation and development, adultemergence and growth index. Larval and pupalKey words An. stephensi, Ageratum, Argemone,Azadirachta, phytoextract, metamorphosis, larvicide.

Relative larvicidal potentiality of nano-encapsulated Temephos and Imidacloprid against Culex quinquefasciatus

Sweta Bhan,Lalit MOHAN,C. N. SRIVASTAVA 한국응용곤충학회 2014 Journal of Asia-Pacific Entomology Vol.17 No.4

Encapsulation of temephos ranging from 1% to 16% and imidacloprid from 1% to 8% within biodegradable andbiocompatible, polyethylene glycol in different ratios was done by using melt-dispersion method. The efficacyof encapsulated forms was evaluated and compared with their non-capsulated forms against larvae of Culexquinquefasciatus. The encapsulated temephos was more toxic than the encapsulated imidacloprid with LC50values of 0.013, 0.010 and 0.003 mg/L after 24, 48 and 72 h, respectively. No doubt, the non-capsulated temephosand imidacloprid were more effective as compared to their encapsulated forms. However, the same mortalityrate was achieved by the slow release of lesser amount of pesticides after encapsulation, e.g., 0.003 mg/L for 8%temephos formulation and 0.019 mg/L for 4% imidacloprid as compared to their non-capsulated form oftemephos and imidacloprid (0.004 and 0.021 mL/L) after 72 h of exposure. Thus, encapsulated forms are moreeconomical and eco-friendly due to controlled slow release of their nanoparticles.

Physiological and Functional Evaluation of the Transposed Human Pylorus as a Distal Sphincter

( Abhijit Chandra ),( Uday C Ghoshal ),( Vishal Gupta ),( Ramendra Jauhari ),( Rajendra N Srivastava ),( Asha Misra ),( Ashok Kumar ) 대한소화기기능성질환·운동학회 2012 Journal of Neurogastroenterology and Motility (JNM Vol.18 No.3

Background/Aims Studies evaluating the human pylorus as a sphincter are scanty and contradictory. Recently, we have shown technical feasibility of transposing the human pylorus for end-stage fecal incontinence. This unique cohort of patients provided us an opportunity to study the sphincter properties of the pylorus in its ectopic position. Methods Antro-pylorus transposition on end sigmoid colostomies (n = 3) and in the perineum (n = 15) was performed for various indications. Antro-pylorus was assessed functionally (digital examination, high resolution spatiotemporal manometry, barium retention studies and colonoscopy) and by imaging (doppler ultrasound, MRI and CT angiography) in its ectopic position. Results The median resting pressure of pylorus on colostomy was 30 mmHg (range 28-38). In benign group, median resting pressure in perineum was 12.5 mmHg (range 6-44) that increased to 21.5 mmHg (range 12-29) (P = 0.481) and 31 mmHg (range 16-77) (P = 0.034) on first and second follow-up, respectively. In malignant group, median post-operative pressures were 20 mmHg (range 14-36) and 21 mmHg (range 18-44) on first and second follow-up, respectively. A definite tone and gripping sensation were felt in all the patients on digital examination. On distal loopogram, performed through the diverting colostomies, barium was retained proximal to the neo-pyloric valve. Both perineal ultrasound and MRI showed viable transposed graft. CT angiography and color doppler studies confirmed vascular flow in the transposed position. Conclusions The human pyloric valve can function as a tonic sphincter when removed from the gastroduodenal continuity. (J Neurogastroenterol Motil 2012;18:269-277)

DESIGN AND DEVELOPMENT OF A HEADING ANGLE CONTROLLER FOR AN UNMANNED GROUND VEHICLE

S. SAHOO,S. C. SUBRAMANIAN,N. MAHALE,S. SRIVASTAVA 한국자동차공학회 2015 International journal of automotive technology Vol.16 No.1

This paper describes the design and implementation of a controller to track the desired heading angle for an unmanned ground vehicle (UGV) considering the limits on rotation of steering wheel and steering motor rate. The well-known “bicycle model” approximation, that considers the vehicle slip angle and ground-wheel interaction, has been used. In this work, combined closed loop control for steering motor and heading angle of the vehicle has been considered for better accuracy. The challenge in designing this control system is to include the actuator dynamics as the response time to steer the front wheel is in the same order as that of the heading angle dynamics of the vehicle. Experiments have been conducted, analysis of data collected is presented and the resulting mathematical representation is explained in detail. Results from both simulation and experimental implementation are also compared. It has been found that the vehicle controller can be tuned effectively to achieve the desired heading angle changes up to twenty degrees within three seconds when the vehicle is moving at a speed of 1.4 m/sec.