Objective To discusse the fouling mechanism of 0.2 ?m Al_2O_3 ceramic membrane in the microfiltration of Qiju Dihuang Pill aqueous extract. Methods Qiju Dihuang Pill aqueous extract was microfiltered in this experiment. The distributions of filtration resistance were studied according to the Darcy-Poiseuille principle. The substance of deposit on the membrane surface was analysed by Fourior transform infra-red spectrum and particle diameter analysis. The characteristic of the surface and cross section of the polluted membrane was observed by SEM. Results The filtration resistance was mainly concentrated on the surface of deposit resistance, the membrane itself and the concentration polarization resistance were less important, and the pore blocking resistance was the least important. Moreover, this result was proved by SEM analysis. The molecule of the fouling substance mainly contained peptid, carbonyl, and hydroxy bonds by IR. The particle size distribution of the deposit substance on the polluted membrane surface: The particle radius taking a larger percentage in volume concentrated in 18.267 ?m around, while the particle radius taking a larger percentage in quantity concentrated in 0.424 ?m around. Conclusion Study on the fouling mechanism of the membrane in the microfiltration provides a great significant guidance for exploring the effective measure of relieving the reduced membrane flux and the appropriate cleaning procotrol.

Objective To discuss the fouling mechanism of ceramic membrane in the microfiltation of extract of Qijudihuang Wan and obtain the effective cleaning method. Method The extract of Qijudihuang Wan was microfilted in this experiment, and the distributions of filtration resistance were studied according to the Darcy-Poiseuille principle. The characteristic of the surface and section of the polluted membrane was analysed by SEM also. Result ①For the main body, the filtration resistance is mainly decided by the deposit resistance, the membrane itself and the concentration polarization resistance are less important, and the pore blocking resistance is least important. Moreover, this result is proved by the analysis of SEM. ②The effective four-step cleaning procotrol, which can almost recover original membrane flux, is achieved by three cleaner, including ultrasound, NaOH solution and HCl solution. Conclusion Based on the different fouling mechanism, the appropriate cleaning method can be obtained. This provides great significance for the application of the industrialized manufacture.

AIM: To discuss the fouling mechanism of 0.2 ?m Al_2O_3 ceramic membrane in the microfiltation of extraction of Qijudihuang Pills, and obtain the effective cleaning procotrol. METHODS: The extract of Qijudihuang Pills microfiltered and the distributions of filtration resistance were studied according to the Darcy-Poiseuille principle. The characteristic of the surface and section of the polluted membrane were analysed by SEM also. RESULTS: ① For the main body, the filtration resistance was mainly decided by the deposit resistance, the membrane itself and the concentration polarization resistance were less important, and the pore blocking resistance was minimum. Moreover, this result was proved by the analysis of SEM. ② The effective four-step cleaning procotrol, which could almost recover original membrane flux, was achieved by three cleaner, including ultrasound, NaOH solution and HCl solution. CONCLUSION: Based on the different fouling mechanism,the appropriate cleaning procotrol can be obtained. This provides great significance for the application of the industrialized manufacture.

AIM: To discuss the fouling mechanism in 0.2 ?m Al_2O_3 commie membrane microfiltation of Tangkeqmg Compound water extract. METHODS: The total filtration resistance and its distribution were used as indexes to study the effect of pore size and materials of ceramic membrane on membrane fouling in clarification. SEM (scanning electronic microgragh) technology was used to study the microstructure of surface and section of new membrane and contammted membrane and physica and chemical examination were done on the fouling substances on the membrane surface. RESULTS: The pore size and materials of membrane affected the total filtration resistance and its distribution in clarification. The results of filtration resistance dislribution and SEM suggested that the fouling of 0.2 ?m Al_2O_3 membrane mainly lied on the surface. The contaminations on membrane surface were mostly the substances holding function groups, such as C=O, CO-NH and C-O-C. According to volume percentage, the semidiameter of contaminations on the membrane was mostly around 23.738 ?m. However, according to quantity percentage, the semidiameter of contaminations on the membrane was mostly around 0.521 ?m. CONCLUSION: Study on the fouling mechanism of the membrane is of great significance for looking for the effective measures for relieving the downward trend of the membrane flux and for the appropriate membrane cleaning in the clarification of Tangkeqing Compound extract using 0.2 ?m Al_2O_3 ceramic membrane.

Objective To study the distribution of filtration resistance in AL2O3(0.2 ?m) ceramic membrane microfiltration of Tangkeqing water extract,obtain the effective membrane cleaning methods,and enrich the theory of ceramic membrane cleaning technology.Methods The filtration resistance and its distribution were got with the filtration model of the Darcy-Poiseuille principle which was modified by M.MDa-Cin,etc.Meanwhile,The microstructure of fouled membrane surface and cross-section was analyzed by SEM.Results The main parts of filtration resistance lay in deposit layer and concentration polarization layer with the ratio of 52.5% and 34.4%,respectively.However,the membrane itself and the pore blocking were in the fewer ratios of 8.8% and 4.3%,respectively.The result was in accordance with that of SEM.The fouled AL2O3 membrane was cleaned with low-pressure tap water and ultrasonic wave successirely.Conclusion The appropriate cleaning means are chosen based on the filtration resistance,which can provide good instructions for the industrialized production.

Graduate education is a major way for training advanced talents in the field of military preventive medicine,and the process management is the key step for training talents with high quality of theoretic creation and experimental skills.In order to cultivate excellent graduate students with distinct military especially naval characters,in recent years,we have made certain exploration and practices during the education management process,facilitating construction of educational and experimental platform,intensifying theoretic ability and lab skills,improving research project selection and design,emphasizing middle evaluation and so on.Now a new type of process management mode of graduate education in military preventive medicine with significant military character has come into being.

Objective:To understand the trend of Helicobacter pylori （Hp） resistance to clarithromycin and levofloxacin and to provide guidance for Hp eradication therapy. Methods:From January 2014 to December 2018， a total of 66 515 patients with gastrointestinal symptoms were enrolled in the First People's Hospital of Wenling. The patients were divided into the following groups： childhood （0 to 6 years old）； juvenile （7 to 17 years old）； youth （18 to 40 years old），middle age （41 to 65 years old），and old age （≥66 years old）. All patients received gastroscopy， gastric mucosal biopsy， Hp culture and drug sensitivity test of clarithromycin and levofloxacin. Results:The Hp positive rate showed a significant downward trend in 2016， 2017 and 2018 （χ²=14.317， 47.079， 88.054， all P<0.05）. The average resistance rate of Hp to clarithromycin from 2014 to 2018 was 22.72% （4 732/20 831） showing an increasing trend， but the increase was slower after 2017. The average resistance rate to levofloxacin was 30.55% （6 364/20 831）， and the overall trend showed a sharp rise from 2015 to 2017 （χ²=38.383， 49.569， both P<0.05）， and a significant decline was detected after 2017 （χ²=18.841， P<0.05）. The resistance rate of Hp to levofloxacin in patients increased with age. The clarithromycin resistance rate first decreased and then increased with age， and the resistance rate in old age （32.52%， 763/2 346） was higher than that in youth （22.09%， 1 086/4 916） and middle age patients （21.21%， 2 854/13 458）， and the differences were significant （χ²=991.071， 144.968， both P<0.05）. The resistance rate of Hp rose from 12.73% （14/110） in juvenile to 43.31% （1 016/2 346） in old age （χ²=228.867， P<0.05）. Conclusion:In recent years， the positive rate of Hp infection in Wenling area has a decreasing trend. Although the resistance rate of Hp to clarithromycin and levofloxacin has been rising slowly or decreasing， it is still at a high level. In the selection of Hp eradication program， the differences between patients in different age groups should be considered with particular attention on the minors.