In this study,thermosensitive and repairable molecularly imprinted solid-phase microextraction fibers were synthesized using spiramycin as template molecule,methacrylic acid and N-isopropylacrylamide as functional monomers,ethylene glycol dimethacrylate as crosslinking agent,and silanized quartz capillary as carrier. The prepared molecularly imprinted solid-phase microextraction fibers were characterized by scanning electron microscope and nitrogen adsorption/desorption,and various parameters affecting the extraction efficiency were optimized. Due to high selectivity and sensitivity of the fibers for macrolide antibiotics,the quantitative analysis of four macrolide antibiotics in food matrix,spiramycin,tilmicosin,tylosin,and josamycin,was peroformed in combination with high performance liquid chromatography. In the range of 0.5 to 50 μg/mL,the chromatographic peak area showed a good linear relationship with the concentration. The spike recoveries of the samples at three different addition levels were between 81.8% and 119.1%;the inter-day precisions were less than 13.8% (n=6),and the intra-day precisions were less than 15.5% (n=3).

Objective To determine the incidence and prevalence of transient ischemic attack (TIA) and to evaluate its epidemiological situation in Hunan province.Methods Seven monitoring points were randomly selected from the province,a total of 8 311 subjects aged≥50 years were then chosen by stratified sampling.The cases counted in prevalence was defined as patients diagnosed before 24:00 o'clock August 31st,2013,and the new diagnosis for incident counting was defined as those diagnosed between 00:00 September 1st,2012 and 24:00 August 31st,2013.Results Among all 8 311 screened subjects,the number of TIA patients was 24 (288.8 per 100 000 people),the incidence of TIA was 7 (85.2 per 100 000 people).Standardized prevalence and incidence were 283.2 and 82.4 per 100 000 respectively using 2010 China census population.Among them,the standardized incidence rate of female was higher than that of male (114.8 per 100 000 person-years vs.48.8 per 100 000 person-years),and the prevalence rate of males was higher than that of female (288.2 per 100 000 people vs.273.2 per 100 000 people).Hypertension is the most important risk factor for TIA (55.2％).Conclusion The incidence and prevalence of TIA in Hunan province are higher than the national average.Hypertension is the main risk factor.

Objective:To examine the associations of pre-pregnancy body mass index (BMI), gestational weight gain, and gestational diabetes mellitus (GDM) with early childhood BMI trajectories.Methods:A total of 1 227 mother-child pairs from the Peking University Birth Cohort in Tongzhou were included in this study. In the cohort, maternal pre-pregnancy weight, height, gestational weight gain, and GDM diagnosis were collected. The children were followed up at birth and at 1, 3, 6, 9, 12, 18, 24, 30, and 36 months of age to obtain height/length and weight data. The longitudinal data-based k-means clustering algorithm was used to identify early childhood BMI trajectory groups. The associations of maternal pre-pregnancy BMI, gestational weight gain, and GDM with early childhood BMI trajectories were analyzed using the logistic regression model. We further explored whether there is an interaction effect between pre-pregnancy overweight/obesity and excessive gestational weight gain on the risk of the high BMI trajectory in early childhood through multiplicative and additive interaction analyses. Results:The prevalence rates of overweight and obesity before pregnancy were 21.2% (260 cases) and 6.6% (81 cases) respectively. The prevalence of excessive gestational weight gain and GDM was 57.7% (708 cases) and 30.9% (379 cases). The early childhood BMI trajectories were named low, medium, and high trajectories, accounting for 30.5%, 45.4% and 24.1%, respectively. After controlling potential confounding factors, it was found that pre-pregnancy overweight ( OR=1.54, 95% CI: 1.12-2.12), obesity ( OR=2.33, 95% CI: 1.41-3.85), and excessive gestational weight gain ( OR=1.47, 95% CI: 1.10-1.97) were risk factors for being in the high BMI trajectory in early childhood. GDM was not significantly associated with early childhood BMI trajectories ( P>0.05). Compared with the independent effects of pre-pregnancy overweight/obesity ( OR=1.90, 95% CI: 1.17-3.09) and excessive gestational weight gain ( OR=1.45, 95% CI: 1.03-2.04), the risk of being in the high BMI trajectory in early childhood was greater when the two factors coexisted ( OR=2.38, 95% CI: 1.60-3.54). However, both the multiplicative and additive models showed no interaction effect between pre-pregnancy overweight/obesity and excessive gestational weight gain. Conclusions:Maternal pre-pregnancy overweight/obesity and excessive gestational weight gain are independent risk factors for children being in the high BMI trajectory in early childhood, providing scientific evidence for obesity prevention.

Objective:To compare the association between body mass index(BMI)trajectories deter-mined by different methods and the risk of overweight in early childhood in a prospective cohort study,and to identify children with higher risk of obesity during critical growth windows of early childhood.Methods:A total of 1 330 children from Peking University Birth Cohort in Tongzhou(PKUBC-T)were included in this study.The children were followed up at birth,1,3,6,9,12,18,and 24 months and 3 years of age to obtain their height/length and weight data,and calculate BMI Z-score.Latent class growth mixture modeling(GMM)and longitudinal data-based k-means clustering algorithm(KML)were used to determine the grouping of early childhood BMI trajectories from birth to 24 mouths.Linear regres-sion was used to compare the association between early childhood BMI trajectories determined by different methods and BMI Z-score at 3 years of age.The predictive performance of early childhood BMI trajecto-ries determined by different methods in predicting the risk of overweight(BMI Z-score＞1)at 3 years was compared using the average area under the curve(AUC)of 5-fold cross-validation in Logistic regres-sion models.Results:In the study population included in this research,the three-category trajectories determined using GMM were classified as low,medium,and high,accounting for 39.7％,54.1％,and 6.2％of the participants,respectively.The two-category trajectories determined using the KML method were classified as low and high,representing 50.3％and 49.7％of the participants,respectively.The three-category trajectories determined using the KML method were classified as low,medium,and high,accounting for 31.1％,47.4％,and 21.5％of the participants,respectively.There were certain differ-ences in the growth patterns reflected by the early childhood BMI trajectories determined using different methods.Linear regression analysis found that after adjusting for maternal ethnicity,educational level,delivery mode,parity,maternal age at delivery,gestational week at delivery,children's gender,and breastfeeding at 1 month of age,the association between the high trajectory group in the three-category trajectories determined by the KML method(manifested by a slightly higher BMI at birth,followed by rapid growth during infancy and a stable-high BMI until 24 months)and BMI Z-scores at 3 years was the strongest.Logistic regression analysis revealed that the three-category trajectory grouping determined by the KML method had the best predictive performance for the risk of overweight at 3 years.The results were basically consistent after additional adjustment for the high bound score of the child's diet balanced index,average daily physical activity time,and screen time.Conclusion:This study used different methods to identify early childhood BMI trajectories with varying characteristics,and found that the high trajectory group determined by the KML method was better able to identify children with a higher risk of overweight in early childhood.This provides scientific evidence for selecting appropriate methods to de-fine early childhood BMI trajectories.

Objective:To study the safety and efficacy of endoscopic combined intrarenal scopic surgery for complicated upper urinary calculi.Methods:The clinical data of 117 patients with complicated upper urinary calculi treated by simultaneous percutaneous nephroscopy combined with flexible ureteroscopy from March 2013 to February 2020 were retrospectively analyzed, including 71 males and 46 females, aged 31-73 years, with an average age of 45 years old. There were 29 cases of multiple kidney and ureteral stones, 22 cases of staghorn stones, 19 cases of postoperative residual stones, 18 cases secondary to urinary diversion, 13 cases of ureteral stricture with stones after kidney transplantation/ureteroplasty/endoscopic lithotripsy, 10 cases of isolated kidney, and 6 cases of caliceal diverticular stones. The maximum diameters of calculi were 13-45 mm, with an average of 27 mm.Results:All operative procedures of 117 patients were successful by one session. The mean operation time was (91.6±10.2) min. All cases were treated with single-channel lithotripsy combined antegrade percutaneous nephroscopy with retrograde flexibl eureteroscopy. An abdominal X-ray (KUB) or non-contrast CT was taken 3 to 7 days after the operation. There was no serious bleeding or infection after the operation, and the first-stage stone-free rate was 87.2% (102/117).Conclusions:The strategy of simultaneous antero-retrograde endoscopic combined intrarenal surgery for complicated upper urinary calculi can improve the success rate and first-stage stone-free rate, and reduce the number of percutaneous renal channel leading to the increasing safety of operation. It is an effective means of endourological management of urolithiasis.