Kinetics of the electrochemical process of galena electrodes in the diethyldithiocarbamate solution

The electrochemical process of galena in a pH 12.8 buffer solution was investigated using chronoamperometry and chronopotentiometry. To establish kinetic parameters on the surface of galena in the diethyldithiocarbamate solution, the exchange current density and the dependence of current density on reaction time were determined. Experimental results demonstrate that the exchange current density of galena is 1.585× 10^-2A/m2 in the diethyldithiocarbamate-free solution. In the diethyldithiocarbamate solution, the thickness of lead diethyldi- thiocarbamate adsorbed on the surface of galena is 3.28 molecular layers, the diffusion coefficient of diethyldithiocarbamate on the surface of galena electrodes is 1.13 × 10^-10 m2/s, and the exchange current density of galena is 0.45 A/m2. Lead diethyldithiocarbamate on the surface of galena is firmly adsorbed.

Bedaquiline-containing regimens in patients with pulmonary multidrug-resistant tuberculosis in China:focus on the safety

Background:World Health Organization recommends countries introducing new drug and short treatment regimen for drug resistant tuberculosis(DR-TB)should develop and implement a system for active pharmacovigilance that allows for detection,reporting and management of adverse events.The aim of the study is to evaluate the frequency and severity of adverse events(AEs)of bedaquiline-containing regimen in a cohort of Chinese patients with multidrug-resistant(MDR)/extensively drug-resistant(XDR)-TB based on active drug safety monitoring(aDSM)system of New Drug Introduction and Protection Program(NDIP).

Computer-vision-guided semi-autonomous concrete crack repair for infrastructure maintenance using a robotic arm

Engineering inspection and maintenance technologies play an important role in safety,operation,maintenance and management of buildings.In project construction control,supervision of engineering quality is a difficult task.To address such inspection and maintenance issues,this study presents a computer-vision-guided semi-autonomous robotic system for identification and repair of concrete cracks,and humans can make repair plans for this system.Concrete cracks are characterized through computer vision,and a crack feature database is established.Furthermore,a trajectory generation and coordinate transformation method is designed to determine the robotic execution coordinates.In addition,a knowledge base repair method is examined to make appropriate decisions on repair technology for concrete cracks,and a robotic arm is designed for crack repair.Finally,simulations and experiments are conducted,proving the feasibility of the repair method proposed.The result of this study can potentially improve the performance of on-site automatic concrete crack repair,while addressing such issues as high accident rate,low efficiency,and big loss of skilled workers.

Levels of three opioid peptides in goats' CNS induced by different electroacupuncture frequencies

Acupuncture is a traditional therapeutic technique in Oriental medicine,which has a long history of 4000 years. As a modern version of hand acupuncture,electroacupuncture (EA) can provide a valid analgesic effect and has little physiological interference. It was successfully used to ameliorate pain not only in varieties of painful diseases,but in various operations,such as cesarean section,gastrectomy,enterectomy and castration,in animals during the 1970s. Since then,analgesia-regulating mechanism of EA has been extensively investigated. Previous studies found that electroacupuncture analgesia (EAA) was involved in modulations of neurotransmitters or neuromodulators in the central nerve system (CNS),and most early studies focused on the role of neurotransmitters such as serotonin,noradrenaline, dopamine and acetylcholine. Later,it was certified that some endogenous opioid peptides (EOPs),mainly including enkephalin,β-endorphin and dynorphin,played a more important role in EAA. EA of different frequencies can promote the release of different EOPs in the CNS. Studies showed that EAA induced by 2 Hz (low frequency) was mediated by the release of met-enkephalin (M-ENK) and β-endorphin (β-EP),while EAA by 100 Hz (high frequency) was mediated by the release of dynorphin-A (DYN-A) in the CNS in rats. Although these results in rats above are extrapolated to give reasonable explanations for acupuncture analgesia phenomenon and its treatment of related diseases in human,there are still some unknown mechanisms to be investigated. It has been proved that analgesia induced by EA varies in animal species. In order to quantitatively estimate the degree of acupuncture-induced analgesia,some researchers used an anesthetic to ensure a complete analgesia and to assess the reduction of the amount of the anesthetics consumed in the EA plus anesthetic group as compared to the anesthetic group without acupuncture. Studies showed EA in combination with anesthetics resulted in the reduction of the dosage of the anesthetics in human,rat and goat by 45%-55%,50%-60% and over 75%,respectively. It is clear that the analgesic effect induced by EA in goats (ruminants) is superior to that in rats or human. Therefore,the modalities of EOP release elicited by different frequencies in ruminants could be different from those in rats. In the present study,goats were stimulated with EA of different frequencies to determine the analgesic efficacy and the release levels of M-ENK,β-EP and DYN-A in the CNS in order to probe into the mechanisms of EA-induced analgesia in ruminants. Goats were stimulated by electroacupuncture of different frequencies: 0,2,40,60,80 or 100 Hz at a set of Baihui,Santai,Ergen,and Sanyangluo points for 30 min. The pain threshold was measured using the method of potassium iontophoresis. The levels of met-enkephalin,β-endorphin and dynorphin-A were determined with SABC immunohistochemisty. The results showed that 60 Hz increased pain threshold by 91%; its increasing rate was higher (P < 0. 01) than that by any other frequency used. The three EOPs were distributed in most analgesia-related nuclei and areas in the CNS. 2 Hz and 100 Hz induced met-enkephalin immunoactivities to increase (P < 0. 05) in nucleus accumbens,septal area,caudate nucleus,amygdala,paraventricular nucleus of hypothalamus,periaqueductal gray,dorsal raphe nucleus and locus ceruleus. These two frequencies elicited β-endorphin immunoactivities to increase (P < 0. 05) in nucleus accumbens,septal area,supraoptic nucleus,ventromedial nucleus of hypothalamus,periaqueductal gray,dorsal raphe nucleus,locus ceruleus,solitary nucleus,amygdale. 60 Hz increased (P < 0. 05) the release of met-enkephalin or β-endorphin in the nuclei and areas mentioned above,and habenular nucleus,substantia nigra,parabrachial nucleus and nucleus raphe magnus. High frequencies induced dynorphin-A immunoactivities to increase (P < 0. 05) in spinal cord dorsal horn and most analgesia-related nuclei in the CNS. It suggested that 60 Hz induced the simultaneous release of the three EOPs in extensive analgesia-related nuclei and areas of the CNS,which may be contributive to optimal analgesic effects and species variation.