Objective: To establish a method for determining the molecular weight and molecular weight distribution of Poly(Lactide-co-Glycolide Acid) (PLGA) using Size Exclusion Chromatography-Refractive Index-Multiangle Laser Light Scattering (SEC-RI-MALLS) and Size Exclusion Chromatography-Refractive Index (SEC-RID), and to compare the results obtained from these two methods.
Methods: For SEC-RI-MALLS, tetrahydrofuran was used as the mobile phase, Shodex GPC KF-803L was employed as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, and an injection volume of 100 μL. For SEC-RID, tetrahydrofuran was also used as the mobile phase, Agilent PLgel 5 μm MIXD-D was used as the chromatographic column with a flow rate of 1 mL·min^-1, column temperature at 30 ℃, differential detector temperature at 35 ℃, and an injection volume of 20 μL. The molecular weight and molecular weight distribution were calculated using Agilent’s GPC software. The newly established methods were validated methodologically, and the molecular weight and molecular weight distribution of 13 batches of samples were determined.
Results: The precision, accuracy, stability, and repeatability tests for SEC-RI-MALLS showed RSD values of 1.35%, 1.58%, 1.53%, and 1.26%, respectively. The SEC-RID method exhibited good linearity (r=0.999 9), with RSD values for precision, accuracy, stability, and repeatability tests (n=6) of 2.05%, 1.62%, 1.30%, and 2.97%, respectively. The results obtained from SEC-RI-MALLS were lower than those from SEC-RID, and the molecular weight distribution coefficient was smaller, but the results from the paired T-test performed with the value measured by SEC-RID method and the value measured by SEC-RI-MALLS method multiplied a conversion coefficient of 1.5 showed no significant difference between the two methods.
Conclusion: Both methods are stable and reliable, and can be used for the determination of PLGA molecular weight and molecular weight distribution based on the specific situations.

Objective:To juxtapose laparoscopic cholecystectomy combined with common bile duct exploration and stone extraction (LC+ LCBDE) against endoscopic retrograde cholangiopancreatography/sphincterotomy with laparoscopic cholecystectomy (LC+ ERCP/EST) in the therapeutic context of acute biliary pancreatitis.Methods:The clinical data of patients with acute biliary pancreatitis in Department of Hepatobiliary Surgery, Datong Third People's Hospital from January 2017 to January 2021 were retrospectively analyzed. A total of 44 patients were inrolled, including 23 males and 21 females, with the age of (60.6±11.7) years. Based on different treatment approaches, the patients were divided into the LC+ LCBDE group ( n=33) and the LC+ ERCP group ( n=11, LC+ ERCP/EST). Total bilirubin, direct bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood amylase, operation time, postoperative hospitalization stays, total hospitalization cost, postoperative anal exhaust time, and postoperative complications (bile leakage, fever, bleeding) were compared between the two groups. Results:There were no significant differences in preoperative total bilirubin, direct bilirubin, ALT, AST, and blood amylase between LC+ ERCP group and LC+ LCBDE groups (all P>0.05). In LC+ LCBDE group, operation time was 110.0 (96.3, 147.5) min, postoperative hospitalization time was 9.0 (7.5, 11.0) d, postoperative exhaust time was 2.0 (1.0, 2.0) d, and in LC+ LCBDE group, operation time was 60.0 (32.0, 65.0) min, postoperative hospitalization time was 7.0 (4.0, 8.0) d, postoperative exhaust time was 1.0 (1.0, 1.0) d. Comparisons with LC+ LCBDE group, LC+ ERCP group had shorter postoperative hospitalization stay and earlier postoperative exhaust time, the total hospitalization cost of LC+ LCBDE group was 23 829.3 (21 779.6, 27 221.9) yuan, which was higher than 36 894.8 (31 963.5, 41 172.2) yuan in LC+ ERCP group, and the differences were statistically significant (all P<0.05). Comparison of postoperative total bilirubin, direct bilirubin, ALT and AST between LC+ ERCP group and LC+ LCBDE group, with no significant difference(all P>0.05). No postoperative complications such as bile leakage, residual stones, fever and bleeding occurred in both groups. Conclusion:Compared with LC+ ERCP/EST, LC+ LCBDE in the treatment of acute biliary pancreatitis, although the operation time and hospital stay are longer, but the total hospitalization cost is less, there is no need for multiple operations, and it can be used as the first choice for acute biliary pancreatitis.

Due to the complex components of polysorbate 80, analysis is time-consuming and labor-intensive, so there is an urgent need to find a method for rapid analysis of polysorbate 80 components.In this study, 10 batches of samples collected from 3 domestic and foreign enterprises were analyzed by UHPLC-HRMS, with the being further results were analyzed by the ExcipientProfiler software and supplemented by the extended database.The results showed that the ExcipientProfiler software could quickly identify the [M+Na]+ peak in the mass spectrogram, and obtain the information of component distribution, the numbers of components and the degree of polymerization of the sample.Meanwhile, the numbers of components obtained by the ExcipientProfiler software could be used to distinguish the injection grade samples from the ordinary grade samples by systematic clustering analysis.In addition, it was found through further supplement that the sample contained other fatty acid ester components by manually searching the relevant extended database.The polyoxyethylene sorbitan tetraoleate components were found in the sample according to the analysis of mass spectrum data.Therefore, although this method is fast and simple, it is necessary to add polyoxyethylene sorbitan tetraoleate components and other fatty acid ester components to further supplement the information in the ExcipientProfiler software, so that it can be better used for the analysis of polysorbate 80.

Objective To analyze the correlation between urinary albumin/creatinine ratio (ACR) and 24-hour urinary microalbumin (UMA) and evaluate the predictive value of ARC for early diabetic nephropathy.Methods A total of 368 patients with type 2 diabetes mellitus were retrospectively collected.Early diabetic nephropathy was defined as 24h UMA 30～＜300 mg/24h.The correlation between ACR and 24hUMA,and the area under the receiver operating characteristic (ROC) curve of ACR in diagnosis of early diabetic nephropathy were calculated.Gender,age,course of disease,fasting venous blood glucose,glycosylated hemoglobin,blood pressure,triglyceride and total cholesterol were used as adjusting variables to establish univariate and multivariate logistic models of ACR for early diabetic nephropathy,respectively.A regression model was used to evaluate the diagnostic value of ACR for early diabetic nephropathy.Results The correlation between ACR and 24h UMA was 0.658.The area under ROC curve of ACR for early diabetic nephropathy was 0.907 before and 0.933 after adjustments of gender,age,course of disease,fasting venous blood glucose,glycosylated hemoglobin,blood pressure,triglyceride and total cholesterol,respectively.The OR value of ACR of diabetic nephropathy was 2.016 before and 2.762 after same adjustments.The calibration of Hosmer-Lemeshow chi-square test evaluation model was 19.362 before (P=0.13) and 14.928 after adjustments (P=0.061).Conclusion ACR is a better predictor for early diabetic nephropathy although its value is influenced by gender,age,course of disease,blood sugar,lipid,and blood pressure.

Objective To discuss the clinical application of percutaneous radiologic gastrostomy (PRG) in treating dysphagia associated with amyotrophic lateral sclerosis (ALS),and to evaluate its safety and improvement effect on patient's nutritional status in ALS patients with pulmonary insufficiency.Methods The clinical data of 51 ALS patients who received PRG were retrospectively analyzed.The success rate of surgery and postoperative complications were recorded.All patients were regularly followed up,and the longterm complications as well as the one-,3-and 6-month mortality rates after the surgery were documented.The improvement of patient's nutritional status was evaluated.Results PRG was successfully accomplished in all 51 patients,the technical success rate was 100％.Mild postoperative complications occurred in 7 patients (13.73％) and severe massive hemorrhage in one patient (2.0％).After PRG,no signs or symptoms of impaired respiratory function were observed.No death occurred in one month and in 3 months after PRG.Six months after PRG,three patients died(6.8 ％,3/44).One month after PRG,31 patients had an increase in body weight of more than 1 kg,and the mean BMI was increased from preoperative t8.60±2.14 to postoperative 19.27±1.81 (one month after PRG),19.17±1.93 (3 month after PRG) and 18.89±2.33 (6 month after PRG).Conclusion For the performance of PRG no gastroscopy or anesthesia is needed,thus,the risk of aspiration asphyxia can be reduced in ALS patients complicated by pulmonary insufficiency and the success rate as well as the safety can be improved.Therefore,this technique is an effective means to ensure that the ALS patients with pulmonary insufficiency can get adequate energy intake to improve their nutritional status.

Objective To understand the status and correlative factors on menarche and first spermatorrhea among children and adolescents,in Chongqing,in order to provide theoretical basis for carrying out sex and health education in this population.Methods By random stratified and cluster sampling,10 498 students (5 372 boys and 5 126 girls),5 to 18 years old and living in Chongqing urban districts,were enrolled.General situation and physical features of the population were studied.Statistics analysis system included logistic regression methods,t-test and chi-square test.Results For urban kids,first experience of spermatorrhea was 0.218 years later than those living in the rural areas (Z=-73.287,P＜0.001),but median age for girls in urban areas was 0.073 years earlier than in rural areas (Z=-71.589,P＜0.001).Except for factor as mother' s education level in the family (x2=21.564,P＜0.001),other family or environment related factors did not show significant difference between the two groups of boys (P＞0.05).However,significant difference appeared in average family income (x2=6.175,P=0.046) between two groups of girls.Data from the logistic analysis showed that BMI,hip circumference,height,weight,number of children in the family,time of sleep and the diet structure were associated with menarche.Correlative factors of boys' first spermatorrhea would include:high-energy snacks,hip circumference,weight,height,school type and mother's education level (P＜ 0.05).Conclusion First spermatorrhea and menstruation of boys and girls were closely related to environment of the family,diet and the time of sleep.

Objective To study the influence of local administration of Icariin on orthodontically induced inflammatory root resorption (OIIRR ).Methods After rat models of orthodontic root movement were successfully established,rats were injected with 200 mg/kg Icariin (Icariin group)or saline (positive control group), respectively.Left maxillary served as the negative control group.The resorption pit of root surface was measured using scanning electron microscopy (SEM), HE staining, and tartrate resistant acid phosphatase (TRAP ). Results The level of TRAP positive cells and root resorption score in Icariin group were significantly lower than those in the positive control group (P < 0.05 ).Each measured value differed significantly between thenegative control group and the positive control group (P <0.05).The level of TRAP positive cells was significantly different (P <0.05),while root resorption scores did not differ between Icariin group and the negative control group (P >0.05).Conclusion Local administration of Icariin may reduce the degree of orthodontically induced resorption.

Objective To investigate the feasibility of a noval anterior cubital approach for the coronoid via flexor?prona?tor teres interval and assess the clinical result. Methods Five formalin?fixed adult cadaver elbows were used. Through a single universal anteromedial longitudinal skin incision, the coronoid tip was exposed via pronator and flexor carpiradialis interval, and coronoid anteromedial facet and base via palm longus and flexor carpi ulnaris interval. The distances from the entry point to the muscles or branching point of the nerves to the line passing through medial and lateral epicondyles, as well as the length were mea?sured with regard to the motor nerve branches arising from median nerve to pronator teres, flexor carpiradialis, palm longus and flexor digiti superficialis, as well as the most proximal two motor branches to flexor carpi ulnaris arising from ulnar nerve. From September 2013 to August 2014, 4 male patients with ulnar coronoid fracture were treated operatively through the above anterior cubital approach in our hospital. They were all left side involved, with an average age of 32 years (range, 16-42 years). According to O’Driscoll classification, there were two cases of type Ib and two cases IIb respectively. They were all treated by open reduction and internal fixation through flexor?pronator teres interval. Results At cubital fossa, there were 2-3 branches to the pronator teres mostly, 1 branch to flexor carpiradialis and palm longus arising from median nerve. The branch to the flexor digiti superficia?lis usually was long and thick, and divided into 2-5 short twigs near muscle. The branch to palm longus had the same trunk with that to flexor digiti superficialis. The branch to flexor digiti superficialis was the most proximal among those passed through the in?terval of pronator teres and flexor carpiradialis, and its entry point to the muscle had an averaged distance of 37.22 mm to the line passing through medial and lateral humeral epicondyles. It was optimal to expose coronoid tip through the interval of pronator teres and flexor carpiradialis. It was safe to expose coronoid proximal to the branch to flexor digiti superficialis. While, it was better to expose the anteromedial facet and base of corocoid through the interval of palm longus and flexor carpiulnaris via median and ul?nar nerve interface. All of the four patients were followed up for an average period of 9 months. They all achieved bone union from 6 weeks to 3months (mean, 9 weeks). All the patients obtained excellent result according to the modified An&Morrey elbow per?formance index with scores from 94 to 100. Conclusion The novel anteromedial cubital approach via flexor?pronator teres is opti?mal for exposure of coronoid.

Objective:To survey the relation of different vertical skeletal facial type and the third molar agenesis.Methods:The vertical face type of 207 subjects was divided into high angle(n=45),average angle(n=99)and low angle(n=63)groups by the assessments of MP-SN angle.The assessment of the third molar was made from panoramic radiographs,then the third molar agenesis rate of different vertical skeletal facial types was analysed.Chi-square criterion examination was conducted with SPSS 17.0 software. Results:In the high angle group,whether in the maxillary or mandibular,unilateral or bilateral,the absent percentage of third molar was higher than that in low angle group(P<0.05).In the females the bilateral maxillary third molar absent percentage was higher than in the males(P<0.05).The absent percentage of maxillary third molar was higher than that of the mandibular third molar(P<0.05).Conclusion:The third molar absence depends on vertical skeletal facial type.The absent percentage of third molar in the in-dividuals with high angle type is higher than that in those with low angle type(P<0.05).

Objective To evaluate the clinical results of operative treatments for the complex posterior tibial plateau fractures via posterior approach. Methods Eleven cases with complex posterior tibial plateau fracture from June 2008 through June 2010 were reviewed retrospectively. There were 7 males and 4females, with age from 33 years to 60 years (average, 47.8 years). According to AO classification, there were 41-B2.2.4 type in 2 cases, 41-B3.1.2 type in 3, 41-B3.3.2 type in 3, 41-B3.1.2 type combined 41-B3.3.2 type in 2, 41-C3.3 type in 1. Carlson posterior lateral approach were used in 5 cases, posterior medial approach were used in 3 cases, and posterior medial and/or lateral approach combined with anterior approach were used in 3 cases. All fractures were fixed with plates. Autogenous ilium grafts were used if necessary.Results All cases were followed up. The average follow-up time was 1.6 years (range, 3-24 months). At the final follow-up visit, bone union was obtained in all cases. The mean Rasmussen score was 16.7 (range, 15-18), and the mean HSS was 86.2 (range, 75-96). The postoperative knee range of motion were 0°-135°, 0°-130° and -10°-125° in 5 cases with posterior lateral plateau fractures, 3 cases with posterior medial plateau fractures and 3 cases with anterior and posterior plateau and intercondylar fractures respectively. There was no vascular and nerve injuries. Loosing or breaking of hardware's was not found. Conclusion The Carlson posterior lateral and/or medial approach is preferred for the complex posterior plateau fractures, with the advantages of direct reduction and stabilization.