Excitability of motor and sensory axons in multifocal motor neuropathy

ObjectiveTo assess excitability differences between motor and sensory axons of affected nerves in patients with multifocal motor neuropathy (MMN).MethodsWe performed motor and sensory excitability tests in affected median nerves of 20 MMN patients and in 20 age-matched normal subjects. CMAPs were recorded from the thenar and SNAPs from the 3rd digit. Clinical tests included assessment of muscle strength, two-point discrimination and joint position.ResultsAll MMN patients had weakness of the thenar muscle and normal sensory tests. Motor excitability testing in MMN showed an increased threshold for a 50% CMAP, increased rheobase, decreased stimulus-response slope, fanning-out of threshold electrotonus, decreased resting I/V slope, shortened refractory period, and more pronounced superexcitability. Sensory excitability testing in MMN revealed decreased accommodation half-time and S2-accommodation and less pronounced subexcitability. Mathematical modeling indicated increased Barrett-Barrett conductance for motor fibers and increase in internodal fast potassium conductance for sensory fibers.ConclusionsExcitability findings in MMN suggest myelin sheath or paranodal seal involvement in motor fibers and, possibly, paranodal detachment in sensory fibers.SignificanceExcitability properties of affected nerves in MMN differ between motor and sensory nerve fibers.     

从积极防御战略浅析我军新型饮用水安全保障体系的构建

随着我军新时期积极防御军事战略的实行,未来战争战场环境将愈发复杂与多样,部队所面临的饮用水水源与水质将更加复杂。我军现有饮用水安全检测、净化技术与装备还存在信息化、一体化程度不高,新型制取饮用水技术研究深度不够,以及对涉及国家安全的重要战略要地水资源现状有待进一步调研等情况。为能在各种特殊和恶劣条件下确保作战人员的饮水用安全,应建立国家战略水资源安全防护体系,加快水安全卫生装备信息化和全天候适应性研究,深入开展特殊环境下饮用水保障新技术研究。     

Modeling the hepatitis A epidemiological transition in Thailand

BackgroundIn most low- and middle-income countries, hepatitis A virus (HAV) is shifting or expected to shift from high endemicity to intermediate or low endemicity. A decreased risk of HAV infection will cause an increase in the average age at infection and will therefore increase the proportion of infections that results in severe disease. Mathematical models can provide insights into the factors contributing to this epidemiological transition.MethodsAn MSLIR compartmental dynamic transmission model stratified by age and setting (rural and urban) was developed and calibrated with demographic, environmental, and epidemiological data from Thailand. HAV transmission was modeled as a function of urbanization and access to clean drinking water. The model was used to project various epidemiological measures.ResultsThe age at midpoint of population immunity remains considerably younger in rural areas than in urban areas. The mean age of symptomatic hepatitis A infection in Thailand has shifted from childhood toward early adulthood in rural areas and is transitioning from early adulthood toward middle adulthood in urban areas. The model showed a significant decrease in incidence rates of total and symptomatic infections in rural and urban settings in Thailand over the past several decades as water access has increased, although the overall incidence rate of symptomatic HAV is projected to slightly increase in the coming decades.ConclusionsModeling the relationship between water, urbanization, and HAV endemicity is a novel approach in the estimation of HAV epidemiological trends and future projections. This approach provides insights about the shifting HAV epidemiology and could be used to evaluate the public health impact of vaccination and other interventions in a diversity of settings.     

Anaesthesia for endoscopic surgery

Anaesthesia for endoscopic airway surgery involves unique challenges. The anaesthetist and surgeon are working in close anatomical proximity and the concept of shared airway is never more relevant. Understanding the planned procedure and the needs of the surgeon for access to the surgical field will enable the provision of anaesthesia and airway management using a variety of techniques. Planning for safe induction, maintenance and emergence of anaesthesia will also be guided by the specific pathology and patient characteristics and requires effective communication between the surgeon and anaesthetist.     

广西南北两地水源水和饮用水中微囊藻毒素-LR含量调查

目的比较广西北回归线两侧的南宁地区和桂林地区水源水和饮用水中微囊藻毒素-LR(microcystin-LR,MC-LR)含量差异。方法于2017年采集南宁地区和桂林地区主要水源水及饮用水水样,采用酶联免疫吸附法(ELISA)检测水中MC-LR的含量。结果南宁地区与桂林地区水源水和饮用水中MC-LR平均含量均未超过我国地表水环境质量标准、饮用水卫生标准限值1μg/L。南北两地水库水中MC-LR平均含量均高于江河水、井水和山泉水(P<0.05)。南宁地区不同类型水源水MC-LR含量与桂林地区相比,水库水MC-LR平均含量较高,差异有统计学意义(P<0.05)。南北两地分散式供水末梢水中MC-LR平均含量均高于农村和城市集中式供水(P<0.05)。南宁地区的水源水和出厂水MC-LR平均含量分别为(0.256±0.048)、(0.210±0.025)μg/L,两者差异有统计学意义(P<0.05)。南宁地区水源水MC-LR含量在10月份达到峰值。结论广西南北两地水源水和饮用水中MC-LR含量均未超过国标中所规定的标准限值,南北两地水库水MC-LR含量存在明显差异,分散式供水MC-LR含量高于集中式供水。南宁地区水源水MC-LR平均含量高于出厂水,且在10月份达到峰值。提示需加强水源水和饮用水水质日常监测,秋季严格控制自来水处理工艺,以保证水质安全。     

环境水样中痕量铜的浊点萃取-火焰原子吸收光谱测定法

目的建立环境水样中痕量铜的浊点萃取(cloud point extraction,CPE)-火焰原子吸收光谱(flame atomic absorption spectrometry,FAAS)测定法。方法样品在p H 9.5的条件下,加入0.4 ml的1 mmol/L 2-(5-溴-2-吡啶偶氮)-5-二乙氨基酚(5-Br-PADAP)溶液,0.1%氯化钙溶液0.1 ml,5%(W/V)Triton X-114溶液0.8 ml,40℃加热15 min后离心,采用火焰原子吸收光谱法进行检测。结果在2~240μg/L的线性范围内,所得回归方程为A=0.002 7c+0.024 6,r=0.995 8。以3倍信噪比计算,方法的检出限为0.62μg/L,富集倍数为36.58倍,平均加标回收率为96.28%~98.08%,RSD为1.67%~3.13%。结论该方法简单、灵敏,具有良好的重现性,适用于环境水样中痕量铜的测定。     

浅析南宁市餐厨垃圾资源化利用和无害化处理厂工程给排水设计

以南宁市餐厨垃圾资源化利用和无害化处理厂的给排水专业工程设计实例,简要介绍和分析餐厨垃圾资源化利用和无害化处理厂给排水设计中的思路和方法。