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.

BACKGROUND:Lingual movable wing is a new type of lingual orthodontic technique and the different stretching lengths of the wring affect the torque control effect of anterior teeth.However,there is yet no related biomechanical research. OBJECTIVE:To investigate the displacement trend of dentition during adduction of mandibular anterior teeth and the effect of different wing stretching lengths on the biomechanical effect of mandibular anterior teeth. METHODS:The data of the mandible and lower dentition were collected by cone-beam CT and reconstructed using Mimics software to establish a three-dimensional finite element model of mandibular anterior teeth adducted by the lingual movable wing.The ANSYS software was used to analyze the initial displacement of the mandibular anterior teeth under the following conditions:A,2 mm stretching length;B,2.5 mm stretching length;C,3 mm stretching length;and D,3.5 mm stretching length. RESULTS AND CONCLUSION:The trend of initial displacement of lower dentition:The central incisors moved lingually with depression,the lateral incisors and canines moved mildly lingually with mesial lingual torsion,the second premolar was tilted distally with a marked lingual inclination and the first molar showed an overall mesial inclination with mesial crown eversion.Therefore,in the adduction cases of mandibular tooth extraction,attention should be paid to the lingual movement of the second premolar,which could be offset by corresponding techniques in clinic.The trend of anterior tooth displacement in all directions:from condition A to condition D,in the sagittal direction,the difference value in crown-root displacement of central incisors changed from-11.891 μm to-5.757 4 μm,indicating that the central incisor changes from oblique movement to overall movement.The difference value in crown-root displacement of lateral incisors changed from-11.828 1 μm to-6.711 45 μm,and that of canines changed from-7.572 3 μm to-4.695 5 μm,indicating that the oblique movement of the lateral incisors and canines is also changing to an overall movement.In the vertical direction,from condition A to condition D,the reduction of incisors was gradually increased,while that of canines was gradually decreased.These findings indicate that the stretching length of the wing can affect the oblique movement trend of the anterior teeth.As the wing continues to stretch,the torque control of the lower anterior teeth will become better.

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.

Objective To investigate the infection status and drug resistance of urogenital tract mycoplasma in Lianyungang district,Jiangsu.Methods Based on retrospective collection of 22 889 cases of suspected mycoplasma genital infection in Lianyungang Mater-nity and Child Health Hospital from 2015 to 2022,the infection and drug resistance rate of genital mycoplasma were analyzed.Results A total of 8 943 genital mycoplasma positive specimens were detected.Among them,the infection rate of Ureaplasma urealyticum(Uu)was the highest,accounting for 33.64％(7 700/22 889),which was significantly higher than that of Mycoplasma hominis(Mh),3.91％(894/22 889),and that of mixed(Uu+Mh)type,1.52％(349/22 889).The difference was statistically significant(P＜0.05).The infection rates of genital mycoplasma and Uu showed increasing trend from 2015 to 2022.The overall infection rates of genital mycoplasma in females were 42.42％,which was significantly higher than that in males of 22.47％.The highest infection rate of 40.84％(6 108/14 955)was found in the group of 20 to 40 years old as compared to those younger than 20 years old as well as those over 40 years old.The genital mycoplasma was highly sensitive to doxycycline,minocycline and josamycin,and the drug resistance rate was lower than 5.00％.From 2015 to 2022,there was an increasing trend of resistance rates to erythromycin,ofloxacin and ciprofloxa-cin in Uu-infected patients(P＜0.05)and erythromycin,roxithromycin,azithromycin and ofloxacin in Mh-infected patients(P＜0.05).Conclusion The incidence of urogenital tract mycoplasma infection in Lianyungang district shows a gradual increase for recent years.Doxycycline,minocycline and josamycin are suitable as the first choice for the treatment of genital mycoplasma infection.Most quinolo-ne drugs have shown high resistance rate,indicating that this type of drugs are possibly overused.The strengthened relevant monitoring of antibacterial drugs should be necessary.

Objective:To compare the clinical efficacy of arthroscopy-assisted and open reduction and internal fixation in the treatment of Schatzker type I-III tibial plateau fractures.Methods:The data of patients with Schatzker type I-III tibial plateau fractures who were treated from August 2017 to July 2019 were retrospectively analyzed. According to the treatment, the patients were divided into the arthroscopic-assisted minimally invasive reduction and internal fixation group (arthroscopy group) and the conventional open reduction and internal fixation group (incision group). In the arthroscopy group, there were 30 patients, 19 males and 11 females were included; the age was 45.13±7.12 years old (range, 29-60 years). Among them, 13 cases were Schatzker type I fractures, 14 cases were Schatzker type II fractures, and 3 cases were Schatzker type III fractures. In the incision group, there were 30 patients, 17 males and 13 females were included; the age was 43.53±7.79 years old (range, 31-58 years). Among them, 11 cases were Schatzker type I fractures, 15 cases were Schatzker type II fractures, and 4 cases were Schatzker type III fractures. The operation time, intraoperative blood loss, postoperative ambulation time, postoperative complete weight-bearing time and postoperative complications were recorded. The degree of knee joint swelling, knee flexion and extension range of motion and the American knee society knee score (AKS score) were compared between the arthroscopy group and the incision group.Results:Both groups were followed up. The follow-up time of the arthroscopy group were 10-18 months, with an average of 14 months; the follow-up time in the incision group were 12-18 months, with an average of 15 months. In the arthroscopy group, the operation time (87.60±9.20 min vs. 94.33±10.65 min), intraoperative blood loss (57.16±9.63 ml vs. 71.93±11.15 ml), postoperative ambulation time (5.13±1.28 d vs. 6.17±1.53 d) and postoperative complete weight-bearing time (12.83±1.68 weeks vs. 14.23±1.77 weeks) were superior to the incision group, and the differences were statistically significant ( t=2.62, 5.49, 2.83, 3.94; all P<0.05). The healing time was 13.33±1.37 weeks in the arthroscopy group and 14.86±1.63 weeks in the incision group, and the difference was statistically significant ( t=3.94, P<0.001). At 1 year after surgery, the range of flexion and extension of knee joint in the arthroscopy group was 116.77°±12.46°, which was better than that in the incision group, which was 109.13°±9.89°, and the difference was statistically significant ( t=2.63, P=0.011). The AKS score in the arthroscopy group was 164.57±11.16 points, and the score in the incision group was 149.53±14.77 points, and the difference was statistically significant ( t=4.45, P<0.001). There were no malunion or compartment syndrome in the arthroscopy group and the incision group. The total incidence of complications in the arthroscopy group was 13% (4/30), including 2 cases of poor wound healing, 2 of poor knee range of motion after operation. The total incidence of complications in the incision group was 23% (7/30), including 4 cases of poor wound healing, 1 of wound infection, 2 of poor knee range of motion after operation. And the difference between the two groups in complication incidence was not statistically significant (χ 2=1.00, P=0.317). Conclusion:Arthroscopic-assisted reduction and internal fixation in the treatment of Schatzker I-III tibial plateau fractures has the advantages of less trauma, less bleeding, early mobility, fewer complications, and better knee joint function, and there are no obvious arthroscopic-related complications, which is a safe and reliable treatment method.

Objective: To investigate the inhibitory effect of polydopamine (PDA) on enamel demineralization in isolated teeth and the induction of hydroxyapatite (HA) production on the surface of demineralized enamel to provide a novel protocol for the prevention and treatment of enamel demineralization. Methods: Twenty isolated bovine teeth were cut into 20 enamel slices and randomly divided into an experimental group and a control group, with 10 slices in each group. The enamel slices in the experimental group were immersed in 2 mg/mL freshly prepared dopamine solution and incubated for 24 hours at room temperature in the dark to prepare the PDA coating, while the control group was left untreated. Then, the isolated bovine teeth, with and without PDA coating, were immersed in artificial demineralization solution at 37 °C for 3 days, followed by 7 days in simulated body fluid (SBF), and the immersion solution was changed daily. The surface morphology of enamel was observed by scanning electron microscopy (SEM), the calcium/phosphorus ratio of the enamel surface was analyzed by energy dispersive spectroscopy (EDS), and the characteristic functional groups in enamel deposits were analyzed by Fourier transform infrared spectroscopy (FTIR). Results: Compared with the control group, the number of demineralized pores produced after 3 d of enamel demineralization with polydopamine coating was less, and the diameter was smaller. EDS elemental analysis showed that the Ca/P ratio after enamel demineralization was 2.37 in the experimental group, which was smaller than the 2.53 ratio in the control group. In the remineralization experiment, after 7 days of remineralization of PDA coated enamel in the experimental group, lamellar grains were produced on the enamel surface, and the growth showed obvious directionality, growth regularity and uniform arrangement. In the control group, the surface of enamel was flocculent mineral deposit, and the crystallinity was poor. The FTIR results proved that the enamel surface deposit of PDA-coated enamel was HA after 7 d of remineralization. Conclusion PDA can affect the nucleation process of HA and promote the production of HA on the surface of demineralized enamel.

Lingguizhugan Decoction (LGZG) has been investigated in basic studies, with satisfactory effects on insulin resistance in non-alcoholic fatty liver disease (NAFLD). This translational approach aimed to explore the effect and underlying mechanism of LGZG in clinical setting. A randomized, double-blinded, placebo-controlled trial was performed. A total of 243 eligible participants with NAFLD were equally allocated to receive LGZG (two groups: standard dose and low dose) or placebo for 12 weeks on the basis of lifestyle modifications. The primary efficacy variable was homeostasis model assessment of insulin resistance (HOMA-IR). Analyses were performed in two populations in accordance with body mass index (BMI; overweight/obese, BMI ⩾ 24 kg/m²; lean, BMI < 24 kg/m²). For overweight/obese participants, low-dose LGZG significantly decreased their HOMA-IR level compared with placebo (-0.19 (1.47) versus 0.08 (1.99), P = 0.038). For lean subjects, neither dose of LGZG showed a superior effect compared with placebo. Methylated DNA immunoprecipitation sequencing and real-time qPCR found that the DNA N6-methyladenine modification levels of protein phosphatase 1 regulatory subunit 3A (PPP1R3A) and autophagy related 3 (ATG3) significantly increased after LGZG intervention in overweight/obese population. Low-dose LGZG effectively improved insulin resistance in overweight/obese subjects with NAFLD. The underlying mechanism may be related to the regulation of DNA N6-methyladenine modification of PPP1R3A and ATG3. Lean subjects may not be a targeted population for LGZG.
Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Overweight/drug therapy* ; Insulin Resistance ; Obesity/drug therapy* ; China ; DNA/therapeutic use*

In February, 2019, a patient with a defect of open dorsal cartilage and bone in the first metatarsal head, including the defects of soft tissue, tendon and joint capsule, was treated in our department. After multiple debridement, the vascularised medial femoral condyle osteochondral chimeric tissue flap was transferred to repair the composite tissue defect in the metatarsal head at the second stage. After 18 months of follow-up, the patient felt no pain in the foot and walking, and there was no sign of lameness and discomfort at donor sites. The postoperative functional recovery was satisfactory.

Non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer. The systemic antitumor therapy of advanced NSCLC has undergone renovations of chemotherapy, targeted therapy and immunotherapy, which results in greatly improved survival for patients with advanced NSCLC. Immune checkpoint inhibitors (ICIs), especially targeting programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1), has changed the treatment paradigm of NSCLC. ICIs have become the standard treatment for advanced NSCLC without epidermal growth factor receptor(EGFR) mutation or anaplastic lymphomakinase(ALK) translocation in the first- or second-line setting, and for locally advanced NSCLC following concurrent radiotherapy and chemotherapy. ICIs are also promising in adjuvant/neoadjuvant therapy. More and more ICIs have been approved domestically for the treatment of NSCLC. Led by the NSCLC expert committee of Chinese Society of Clinical Oncology (CSCO), this consensus was developed and updated based on thoroughly reviewing domestic and foreign literatures, clinical trial data, systematic reviews, experts' discussion and the consensus(2019 version). This consensus will aid domestic clinicians in the treatment of NSCLC with ICIs.
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Objective:To explore the morphological characteristics, treatment strategies and clinical results of complex hyperextension tibial plateau fractures.Methods:From October 2017 to January 2019, data of 27 patients with complex hyperextension tibial plateau fractures were retrospectively analyzed. There were 19 males and 8 females with an average age of 43.4 years (range, 23-68 years). According to Schatzker classification of tibial plateau fractures: there are 8 cases of type IV, 5 of type V, and 14 of type VI; according to the three-column theory classification: there are 8 cases of two-column fracture and 19 cases of three-column fracture. Bicondylar fractures were treated with medial Tomofix locking plate and anterolateral L-shaped locking plate through medial and anterolateral approach; tibialmedial condylar fractures was treated with T-shaped plate and posteromedial locking plate through extended medial approach. Patients with anterior tibial fractures were treated with horizontal strip plate through modified anterior median approach. Combined soft tissue or bone injury was repaired. The fracture healing and reduction were evaluated by X-ray and CT scan. The reduction of tibial plateau fracture was evaluated by Rasmussen radiology standard, and the knee joint function was evaluated 12 months after the operation by the score of American hospital for special surgery (HSS).Results:All the 27 surgeries were performedsuccessfully. The operation time was 130-350 minutes, with an average time of 165 minutes. Twenty-seven cases were followed up for 12-24 months, with an average period of 15.8 months. All fractures were healed. The average clinical healing time was 13.5 weeks (range, 10-18 weeks). Twelve months after operation, Rasmussen's radiology score was 13-18, with an average of 16.7 points, among them there were 19 excellent and 8 good. Twelve months after the operation, the score of HSS knee joint was 82-98, with an average score of 93.2 points, and there were 22 cases excellent, 4 cases good and 1 case fair. The excellent and good rate was 96.2% (26/27).Conclusion:Complex hyperextension tibial plateau fractures often combined with tibial bicondylar, medial tibial condyle or anterior tibial fractures. According to the morphological characteristics of complex hyperextension tibial plateau fractures, using appropriate surgical approach and internal fixation, repairing ligament soft tissue structure and reconstructing knee joint stability can achieve satisfactory results.