Contact Activity of Combination Use of Three Kinds of Plant Extracts on Helicoverpa armigera

[Objectives] The aim was to study the contact activity of combination use of garlic,onion and stone calamus extracts on Helicoverpa armigera and their co-toxicity coefficient( CTC) and mixture ratio. [Methods] Leaf dipping method was used to study the contact activity of the three kinds of plant extracts against H. armigera. Based on this,the co-toxicity coefficient of the compound of the three kinds of extracts was determined. Orthogonal test was used to explore the optimal mixture ratio of the three kinds of extract for combination use. [Results]The extracts of garlic,onion and stone calamus had good inhibition and contract activity on H. armigera larvae. The LC50 values of the three kinds of plant extracts against H. armigera were 175. 0,217. 0 and 79. 2 mg/L,respectively. When the mixture ratios of stone calamus to garlic,and stone calamus to onion were both 2:1,the extract showed a synergistic effect( CTC > 120); when the mixture ratios of stone calamus to garlic,and stone calamus to onion were 1:1 and 1:2,respectively,the extracts showed an additive effect( 80 < CTC < 120); and then garlic extract and onion extract were mixed according to the ratio of 1:1,the additive effect was slight( CTC < 90). Among the three kinds of extracts,the extract of stone calamus showed the strongest contact activity,followed by that of garlic. The results of co-toxicity coefficient determination and orthogonal test showed that the contact activity of combination use of the three kinds of extracts was stronger than that of the single extract overall. When the extracts of garlic,onion and stone calamus were mixed according to the ratio of 2:3:1( mass concentration ratio),the contact activity of the compound against H. armigera reached 95. 3%. [Conclusions]The study results provide a scientific basis and theoretical reference for the development of new plant-derived pesticides based on the pharmacodynamics of garlic,onion and stone calamus.

Contact Activities of 20 Plant Extracts against Lipaphis erysimi Kaltenbach

[Objective] The aim was to screen out plants which had strong contact activity against Lipaphis erysimi Kaltenbach. [Method] Twenty plant species which were collected from Gupo Mountain in Hezhou of China were extracted with methanol by cold soaking method. Contact activities of 20 methanol plant extracts against L. erysimi were determined by capillary micro spot method. [Result] The methanol extracts from Mussaenda esquirolli Levi. and Folium trematis Orientalis had the highest contact activities against L. erysimi at the dose of 10 p^g/head, and their 24 h corrected mortality rates were 92.22% and 92.15%, respectively; followed by Folium trematis and Viola hossei, with 24 h corrected mortality rate of 87.59% and 82.95%, respectively. The methanol extract of Hedyotis lancea had medium activity, with 24 h corrected mortality rate of 65.52%. Methanol extracts of the other plants had low contact activities against L. erysimi, with the corrected mortality rate lower than 50%. The methanol extracts of M. esquiroUi, F. variolosa and F. trematis had high contact toxicity, with LDS0 of 0. 768 6, 0.784 1 and 1. 504 4 μg/head, respectively. [ Conclusion] M. esquirolli, F. variolosa and F. trematis show exploitation potential, and they are worth further studying.

Subthalamic deep brain stimulation for Parkinson＇s disease： correlation of active contacts and electrophysiologically mapped subthalamic nucleus

Background Subthalamic deep brain stimulation （STN-DBS） has been shown to be effective in the treatment of Parkinson＇s disease. The site for permanent stimulation is still in debate. This study aimed to assess the position of active contacts in relation to the subthalamic nucleus. Methods We reviewed the location of 40 electrodes in 34 patients who underwent STN-DBS. The position of electrode was evaluated by postoperative magnetic resonance imaging （MRI）. The position of active contacts was compared with the subthalamic nucleus （STN） determined by intraoperative electrophysiological mapping and postoperative MRI. Results The average position of the 40 active contacts was （11.7±1.2） mm lateral, （0.6±1.3） mm anterior, and （0.7±1.4） mm vertical to the midcommissural point. The dorsal margin of the STN was （11.6±1.1） mm lateral, （0.2±1.1） mm anterior, and （1.3±1.1） mm vertical to the midcommissural point. When compared with the dorsal margin of the STN, the active contacts were located more dorsally （P=0.033） and anteriorly （P=-0.012）, no significant difference was found in the lateral direction （P=0.107）. When compared with the position of the STN, 26 （65%） of active contacts were located in the region dorsal to the STN, only 13 （32.5%） were located in the upper two-thirds portion of STN. Conclusions The site for permanent stimulation appears to be in the subthalamic region dorsal to the STN, close to the dorsal margin of the STN. Besides the dorsal portion of the STN, other structures such as fields of Forel H and zona incerta may also be involved in the therapeutic benefit of deep brain stimulation.

Supporting tuberculosis program in active contact tracing:a case study from Pakistan

Tuberculosis(TB)is on the rise in Pakistan and there could be multiple reasons including poverty,difficulty in access to TB treatment services,non-compliance with treatment,social stigma etc.According to the TB program managers,limited treatment and testing sites for tuberculosis and lack of trained human resources play a major role in compromising TB management.A major lacuna in the TB control program is the absence of active contact tracing strategy.This is essential for a disease where positive cases are known to be able to infect a further 10-15 individuals in a year.Tackling tuberculosis in Pakistan has been beleaguered by funding challenges and other systems’bottlenecks such as lack of skilled human resources and insufficient supply of medicines,despite the fact that disease burden is one of the highest in the world.Although it is a notifiable disease,active case finding,contact tracing and reporting is notoriously low throughout the country.Access to diagnostics and treatment facilities has been limited and stigma attached to the disease remains deeply entrenched among the communities.Researchers have shown that enhanced and active approaches to contact investigation effectively identifies additional patients with TB among household contacts at a relatively modest cost.USAID’s Integrated Health Systems Strengthening and Service Delivery Activity extended support to the Health Departments of Sindh and Khyber Pakhtunkhwa provinces.In collaboration with the two provincial TB programs,community based active contact tracing was conducted on 17,696 individuals,based on the index cases.Among the contacts traced,243 cases were diagnosed as drug sensitive or drug resistant TB.Awareness sessions were conducted to sensitize people on the various aspects of disease and importance of getting tested.The project also supported establishing three satellite Programmatic Management of Drug Resistant Tuberculosis(PMDT)sites for drug resistant TB treatment,enhancing the programs’diagnostic and testing capacity.