Effects of Agitating Intensity on Anaerobic Digestion Performance of Corn Straw Silage

Anaerobic fermentation can increase biomass energy use efficiency of crop straws and realize win-win of energy and environment.This paper explored the biogas generation performance of anaerobic digestion of cow dung liquid as nitrogen source in three different levels of stirring intensity at 30℃ constant temperature condition. Through p H value,biogas production,chemical oxygen demand( COD),methane content,volatile fatty acid( VFA),principal component analysis( PCA) and modified Gompertz model,effects of agitating intensity on anaerobic digestion performance of corn straw silage were evaluated. Results indicate that the COD removal rate of three agitating intensity levels is higher than 85%,and p H value is about 6.5; the cumulative biogas production after 20 days is 2h > 4h > 1h of agitating; in the49 th day,the biogas production is 1.9 Lat 30 min /2h,1.7 L at 30 min /4 h,and 1. 6 Lat 30 min / h; the maximum biogas production rate is 30 min /2h > 30 min /4h > 30 min / h; and the maximum methane production rate is 30 min /4h > 30 min /2h > 30 min / h; in the same energy consumption,the biogas production at 30 min /4h is higher than 1h. In conclusion,overall analysis of energy consumption and economic factors indicate that 30 min /4 h agitating intensity is more suitable for straw biogas fermentation project. This study is expected to provide theoretical foundation for biogas fermentation project.

A National Multicenter Survey on Management of Pain, Agitation, and Delirium in Intensive Care Units in China

Background： The management of pain, agitation, and deliriunl （PAD） in Intensive Care Unit （ICU） is beneficial for patients and makes it widely applied in clinical practice. Previous studies showed that the clinical practice of PAD in ICU was improving： yet relatively little intbrmation is available in China. This study aimed to investigate the practice of PAD in ICUs in China. Methods： A multicenter, nationwide survey was conducted using a clinician-directed questionnaire from September 19 to December 18, 2016. The questionnaire focused on the assessment and naanagement of PAD by the clinicians in ICUs. The practice of PAD was compared among the lbur regions of China （North, Southeast, Northwest, and Southwest）. The data were expressed as percentage and fi＇equency. The Chi-square test, Fisher＇s exact test, and line-row Chi-square test were used. Results： Of the 1011 valid questionnaire lbrms, the response rtite was 80.37%. The clinicians came from 704 hospitals across 158 cities of China. The rate of PAD assessment was 75.77%, 90.21%, and 66.77%, respectively. The rates of PAD scores were 45.8%, 68.94%, and 34.03%, respectively. The visual analog scale, Richmond agitation-sedation scale, and conlktsion assessment method lbr the ICU were the first choices of scales for PAl） assessment. Fentanyl, midazolam, and dexmedetomidine were the first choices of agents for analgesic, sedation, and delirium treatment. While choosing analgesics and sedatives, the clinicians put the pharmacological characteristics of drugs in the first place （66.07% and 76.36%）. Daily interruption for sedation was carried out by 67.26% clinicians. Most of the clinicians （87.24%） used analgesics while using sedatives. Of the 738 （73%） clinicians titrating the sedatives oil the basis of the proposed target sedation level, 268 （26.61%） clinicians just depended on their clinical experience. Totally, 519 （51.34%） clinicians never used other nondrug strategies tbr PAD. The working time of clinicians was an important thctor in the management of analgesia and sedation rather than their titles and educational background. The ratios of pain score and sedation score in the Southwest China were the highest and the North China were the lowest. The ratios of delirium assessment and score were the same in the four regions of China. Moreover, the first choices of scales for PAD in the four regions were the same. However, the top three choices of agents in PAD treatment in the four regions were not the same. Conclusions： The practice of PAD in China lbllows the international guidelines; however, the pain assessment should be improved. The PAD practice is a little different across the four regions of China： however, the trend is consistent. Trial Registration： The study is registered at http：//www.clinicaltrials.gov （No. ChiCTR-OOC-16000014, www.chictr, org.cn/index.aspx.）.