Asingleparticle-inductivelycoupledplasmamassspectrometric(SP-ICP-MS)methodwas established to detect the size distribution and number concentrations of silver nanoparticle ( AgNPs) in dilute aqueous solution. The optimal dwell time was 3 ms to reduce possibility of two or more particles entering into detector simultaneously. An iterative algorithm was applied to distinguish AgNPs as outliers from baseline and dissolved metal ion signal if the measured intensity was beyond five time standard deviation of whole data. Size distribution and number concentration of three commercial silver nanoparticle dispersions ( nominal diameters of 30, 50, 100 nm) were determined using SP-ICP-MS. The result of SP-ICP-MS is accurately similar to the transmission electron microscopy ( TEM) , indicating that SP-ICP-MS is able to size silver nanoparticles. The particle size detection limit is 25 nm and the limit of number concentration is 8 × 104 particles/L in dilute solution. Tap water added with silver nanoparticle was tested to obtain a similar size distribution and number concentration. This method is simple, fast and highly sensitive, which can be used to investigate risk assessment of silver nanoparticle in aqueous environment and monitor silver nanoparticle in drinking water.

OBJECTIVE To screen for a simple,accurate and no-traumatic detecting method of Helicobacter pylori(Hp). METHODS Hp in gastric fluid and dental plaque was detected with fluorescent antibody method,bacterial culture,urease test and Hp diagnosis card at the same time in 62 cases with gastric and duodenal disease.The gather of gastric fluid applied the capsule method. RESULTS The detective rates of Hp in gastric fluid by four methods were 85.5%,9.7%,61.3%,and 56.5%;the detective rates of Hp in dental plaque by four methods were 88.7%,25.8%,69.4%,and 90.3%,respectively. CONCLUSIONS Fluorescent antibody method combined with capsule method detecting Hp in gastric fluid is specific,sensitive and without trauma.Thus,it is suggested to be used clinically.

Objective To understand the empiric antimicrobial use in patients with pyelonephritis in a hospital,and pro-vide reference for clinical rational antimicrobial use.Methods Data of 620 patients with pyelonephritis admitted to the nephrology department of a hospital between January 2011 and September 2014 were collected,application of antimicrobial agents,coincidence between empiric antimicrobial use and antimicrobial susceptibility testing results in patients with different diseases and different ages were analyzed.Results Before antimicrobial susceptibility testing results were reported,620 pa-tients use 625 times of antimicrobial agents,5 of whom used two kinds of antimicrobial agents at the same time,8 varieties in 15 types of antimicrobial agents were involved,the most frequently used antimicrobial agents were third generation ceph-alosporins,cephamycins,and fluoroquinolones.The overall,partial,and non-coincidence rate between antimicrobial use and antimicrobial susceptibility testing results were 64.32%(n=402),8.32%(n=52),and 27.36%(n=171)respective-ly.The overall coincidence rate in patients with acute pyelonephritis was higher than those with chronic pyelonephritis (77.61% [n=357]vs 58.79%[n=97],P <0.05).The overall coincidence rate in patients <50 years old and ≥50 years old were 68.12%(156/229)and 75.25%(298/396)respectively,there was no significant different between two groups (χ2 =2.93,P =0.09).Conclusion The non-coincidence rate between empiric antimicrobial use and antimicrobial suscepti-bility testing results is high,measures needs to be taken to improve the empiric antimicrobials use.

Objective To explore the application effect of"three-station"teaching rounds in standardized training teach-ing rounds of general surgery residents.Methods 50 trained doctors from the general surgical base from July 2022 to July 2023 were randomly selected and divided into two groups,with 25 patients in each.The observation group used a"three-station"teaching ward round,while the control group used a traditional teaching ward round mode.The exam scores,ward round effects,satisfaction,and experience were compared.Results The total scores of the observation group were significantly higher than those of the control group(P＜0.05),and the scores of the medical history collection and physical examination in the case anal-ysis test and skill test were significantly higher than those of the control group(P＜0.05).There was no significant difference in the theoretical test scores between the two groups(P＞0.05).The proportion of"Yes"in the questionnaire of the observation group was higher than that of the control group in the aspects of improving the diagnosis and treatment of diseases,clinical think-ing,doctor-patient communication ability and increasing learning interest(P＜0.05).The satisfaction of questionnaire teaching round in the observation group was 84.0％,significantly higher than that in the control group(60.0％)(P＜0.05).In the observation group,the percentages of the attending physicians and the teaching rounds were 64.0％and 68.0％,respectively,which were significantly higher than those of the control group(28.0％and 32.0％,P＜0.05).Conclusion The"three-sta-tion"teaching ward round can improve the exam scores,ward round effectiveness and satisfaction,improve the experience of attending physicians and teaching ward round subjects,and is worth promoting in various resident training bases.