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:The prediction model of postoperative recurrence of ovarian endometriosis cyst(OEM)was constructed to provide a reference for evaluating postoperative recurrence of OEM patients.Methods:The clinical,pathological and follow-up data of 342 patients who underwent the initial laparoscopic ovarian cystectomy for OEM at The Second Hospital of Hebei Medical University from January 1,2017 to October 31,2021 were retro-spectively analyzed.Based on univariate and multivariate Cox regression analysis,the relevant factors affecting OEM recurrence were identified.According to the results of multivariate analysis,a nomogram was drawn.The C index and receiver operating characteristic(ROC)curve were used to test the efficiency of the prediction model.Results:The 2-year recurrence rate of OEM patients was 20.4%and the 5-year recurrence rate was 35.2%.Uni-variate and multivariate Cox regression analysis showed that menstrual cycle(HR 0.916,95%CI 0.860-0.976,P=0.006),delivery≥1(HR 0.376,95%CI 0.171-0.827,P=0.015),CA125≥100 U/ml(HR 1.790,95%CI 1.167-2.746,P=0.008),total cyst diameter≥10 cm(HR 2.254,95%CI 1.318-3.854,P=0.003),and postoperative medications(HR 0.434,95%CI 0.292-0.644,P=0.000)were associated with OEM recurrence and were included in the no-mogram prediction model.The C-index of the nomogram prediction model was 0.710(95%CI 0.665-0.754),and the area under the curve(AUC)of the ROC for OEM patients with recurrence at 2 years after surgery was 0.786 and 0.708 at 5 years.Conclusions:In this study,we developed a nomogram to predict the probability of recur-rence at 2 years and 5 years for OEM patients under 45 years who underwent conservative surgery,which has i-deal predictive performance and helps clinicians to screen high-risk patients,and thus give high-risk OEM patients additional attention and intervention.

Objective:The prediction model of postoperative recurrence of ovarian endometriosis cyst(OEM)was constructed to provide a reference for evaluating postoperative recurrence of OEM patients.Methods:The clinical,pathological and follow-up data of 342 patients who underwent the initial laparoscopic ovarian cystectomy for OEM at The Second Hospital of Hebei Medical University from January 1,2017 to October 31,2021 were retro-spectively analyzed.Based on univariate and multivariate Cox regression analysis,the relevant factors affecting OEM recurrence were identified.According to the results of multivariate analysis,a nomogram was drawn.The C index and receiver operating characteristic(ROC)curve were used to test the efficiency of the prediction model.Results:The 2-year recurrence rate of OEM patients was 20.4%and the 5-year recurrence rate was 35.2%.Uni-variate and multivariate Cox regression analysis showed that menstrual cycle(HR 0.916,95%CI 0.860-0.976,P=0.006),delivery≥1(HR 0.376,95%CI 0.171-0.827,P=0.015),CA125≥100 U/ml(HR 1.790,95%CI 1.167-2.746,P=0.008),total cyst diameter≥10 cm(HR 2.254,95%CI 1.318-3.854,P=0.003),and postoperative medications(HR 0.434,95%CI 0.292-0.644,P=0.000)were associated with OEM recurrence and were included in the no-mogram prediction model.The C-index of the nomogram prediction model was 0.710(95%CI 0.665-0.754),and the area under the curve(AUC)of the ROC for OEM patients with recurrence at 2 years after surgery was 0.786 and 0.708 at 5 years.Conclusions:In this study,we developed a nomogram to predict the probability of recur-rence at 2 years and 5 years for OEM patients under 45 years who underwent conservative surgery,which has i-deal predictive performance and helps clinicians to screen high-risk patients,and thus give high-risk OEM patients additional attention and intervention.

As an active hydroxyanthraquinone ingredient, emodin is abundant in Chinese medicine herbs, such as Rheum palmatum, Polygonum cuspidatum and Polygonum multiflorum.Modern pharmacological studies have shown that emodin has a variety of pharmacological activities including anti-tumor, anti-inflammatory and immunoregulatory, antibacterial and anti-viral effects, myocardial protection, neuroprotection, renal protection, bone protection, antifibrosis and so on, which indicate its high medicinal value and broad application prospects.This article aims to summarize the progress in the pharmacological activity and mechanism of action of emodin published in domestic and international journals over the last 5 years and highlight the potential targets and molecular signaling pathways linked with emodin, so as to provide some clues and references for further development and clinical application of emodin.