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 investigate the changes and diagnostic value of serum hypoxia inducible factor 1 subunit alpha(HIF-1α)and Toll-like receptor 4(TLR4)levels in patients with chronic obstructive pulmonary disease(COPD)complicated with pulmonary Aspergillosis infection.Methods A total of 240 COPD patients who visited Xi'an Qinhuang Hospital(hereinafter referred to as the hospital)from December 2020 to Decem-ber 2023 were selected as the study subjects in the study,and another 218 volunteers who underwent physical examinations at the hospital were selected as the control group.The COPD patients were separated into an in-fected group(124 cases)and an uninfected group(116 cases)based on whether they had pulmonary Aspergil-losis infection.Enzyme-linked immunosorbent assay was applied to detect the levels of HIF-1α and TLR4 in patients.Fully automated biochemical analyzer was applied to detect lactate dehydrogenase(LDH)and albu-min(ALB)levels.Multivariate Logistic regression was applied to analyze the influencing factors of infection in COPD patients.Pearson correlation was applied to analyze the correlation between HIF-1α and TLR4 levels in the infected group.Receiver operating characteristic(ROC)curve was applied to analyze the diagnostic val-ue of HIF-1α and TLR4 levels for the occurrence of infection in COPD patients.Results Compared with the control group,the COPD group showed an increase in HIF-1α and TLR4 levels(P＜0.05).Compared with the uninfected group,the proportion of dyspnea,antibiotics＞3 types,the duration of antibiotic use ≥ 14 days,mechanical ventilation procedures,the longer glucocorticosteroid(GC)use time,and levels of LDH,HIF-1α,TLR4 in the infected group were higher(P＜0.05),while the level of ALB was lower(P＜0.05).The types of antibiotics＞3 types,the duration of antibiotic use ≥ 14 days,the duration of GC use,and elevat-ed levels of LDH,HIF-1α,and TLR4 were independent risk factors for infection in COPD patients(P＜0.05),while elevated level of ALB was an independent protective factor for infection in COPD patients(P＜0.05).The levels of HIF-1α and TLR4 in the infected group were positively correlated(r=0.453,P＜0.001).The area under the curve(AUC)of HIF-1α and TLR4 in diagnosing infection in COPD patients alone was 0.816 and 0.813,and the AUC of their combined diagnosis was 0.930,which was better than their indi-vidual diagnoses(Zcombination-HIF-1α=4.923,Z combination-TLR4=5.192,P＜0.001,P＜0.001).Conclusion The levels of HIF-1α and TLR4 increase in COPD patients,and further increase after infection with pulmonary Aspergil-lus.They are independent risk factors for infection in patients,and the two are positively correlated.The combined di-agnosis of pulmonary aspergillosis has certain value and provides a theoretical basis for clinical diagnosis.

OBJECTIVE To establish HPLC methods with different separation principles to analyze the relevant impurities in the APIs of bivalirudin from seven enterprises, to provide a basis for the comprehensive control of related substances of bivalirudin. METHODS Reversed-phase high performance liquid chromatography(RP-HPLC) was used to separate and analyze 11 kinds of impurities. Hydrophilic chromatography(HILIC)-HPLC was used to control four process impurities. Polymers were determined by size exclusion chromatography(SEC)-HPLC. RESULTS The established RP-HPLC could effectively separate the principal component and 11 impurities, the correction factors of 11 impurities were between 0.8−1.2, the detection concentration of bivalirudin was 0.1 μg·mL−1, and the detection limit was 0.004%. The established HILIC-HPLC could effectively separate the principal components and four process impurities, and the detection concentration of bivalirudin was 0.3 μg·mL−1, and the detection limit was 0.01%. Under SEC-HPLC conditions, the polymer and bivalirudin peaked sequentially, the resolution of the two was 2.9, the detection concentration of bivalirudin was 6 ng·mL−1, and the detection limit was 0.000 6%. Fifteen kinds of known impurities and polymers in 15 batches of samples from 7 enterprises were calculated by the self-control method of principal components, and the impurity contents from different enterprises had a certain correlation with their production processes. CONCLUSION The three different principles of the method have good specificity, high sensitivity, good durability, and reliable results, and can be used for quality control of substances related to bivalirudin.

Objective:To established a rapid method for the determination of lactose(C12 H22 O11)content.Methods:The specific rotation([α]20D)of pure lactose was measured with lactose extract product,and the correc-tion coefficient was calculated.The measured rotatory value of the sample was multiplied by the correction coeffi-cient to obtain the mass(g)of lactose in the test product,and the lactose content was calculated.The equivalence of the newly established polarimetric method and the legal test method(HPLC-RID method)for the determination of lactose content was studied.Results:The linear relation of established method was excellent with the range of 0.05-0.20 g·mL-1(r=1.000 0)and the method also had good reproducibility(RSD=0.07％(n=6)).The lactose content of 141 batches samples measured by polarimetry was compared with the results determined by official analytical procedure,and the results showed the relative deviation between the same batches was less than 1.0％.The results of one-way ANOVA also showed that there was no significant difference between two groups(Sig.＞0.05).Conclusion:The performance of polarimetry is comparable to HPLC-RID in the Chinese Pharma-copoeia 2020 Vol Ⅳ.Meanwhile,the polarimetry can reduce the test cost,shorten the test time and meet the requirements of the quality control.

Galactinol synthase (GolS) genes play important roles in plant response to abiotic stress. In this research, the plant expression vector of soybean GmGolS2-2 gene was constructed and transformed into tobacco to study the drought tolerance of transgenic tobacco. A GmGolS2-2 gene with 975 bp coding sequence was cloned from soybean leaves by reverse transcription-polymerase chain reaction (RT-PCR). GmGolS2-2 was linked to the plant expression vector pRI101 by restriction enzyme sites Nde Ⅰ and EcoR Ⅰ, and transformed into tobacco by leaf disc method. Genomic DNA PCR and real-time PCR showed that three GmGolS2-2 transgenic tobacco plants were obtained. The growth status of GmGolS2-2 transgenic tobacco under drought stress was better than that of wild-type tobacco. After drought stress treatment, the electrolyte leakage and malondialdehyde content of transgenic tobacco were lower than those of wild-type tobacco, but the proline content and soluble sugar content were higher than those of wild-type tobacco. The results of real-time PCR showed that the heterologous expression of GmGolS2-2 increased the expression of stress-related genes NtERD10C and NtAQP1 in transgenic tobacco. The above results indicated that GmGolS2-2 improved drought resistance of transgenic tobacco.
Drought Resistance ; Tobacco/genetics* ; Soybeans/genetics* ; Plant Proteins/metabolism* ; Plants, Genetically Modified/genetics* ; Stress, Physiological/genetics* ; Droughts ; Gene Expression Regulation, Plant

Intervertebral disc degeneration is the most common cause of chronic low back pain and the leading cause of disability in adults. The fact that lacking of effective treatment methods often causes a serious economic and social burden. Intervertebral disc degeneration is the result of multifactorial factors. The prevalence of intervertebral disc degeneration increases drastically with age, what is more, mechanical trauma, genetic predisposition,lifestyle factors and certain metabolic disorders. At present, the main treatment methods both pharmacological and surgical interventions just aim at relieving symptoms and improving function, and can not fundamentally reverse the process of intervertebral disc degeneration, which not only bring inevitable side effects and high cost, but also the long-term curative effect is limited. In theory, biological therapy can not only reverse or delay the process of it, but also can maximize preservation and restore the normal physiological function of the disc, which has been the focus and hot spot areas of research in recent years. The methods of inhibiting inflammation, promote the proliferation and division of residual cells, stem cell transplantation, cell scaffolds and new biomaterials all provide new ideas and direction for the treatment of intervertebral disc degeneration. This paper makes a review of the research progress in related fields, in order to provide a valuable reference for the selection of intervertebral disc degeneration treatment options.

Objective:To investigate drug resistance gene in Mycoplasma pneumoniae(MP) and the distribution of 13 respiratory pathogens in bronchoalveolar lavage fluid(BALF) of children with Mycoplasma pneumoniae pneumonia(MPP).Methods:A total of 100 BALF of children with MPP in Peking University Third Hospital and Peking University First Hospital from January 2018 to January 2019 were collected.Fluorogenic quantitative PCR was used to detect nucleic acid and it′s drug resistance gene of MP and multiple PCR method was adopted to detect influenza A virus, influenza A virus-H 1N 1, influenza A virus-H 3N 2, influenza B, human parainfluenza virus, adenovirus, human bocavirus, human rhinovirus, Chlamydia pneumoniae, human metapneumovirus, MP, human coronavirus, and respi-ratory syncytial virus gene, and the results were compared by using Chi square test. Results:In 100 BALF samples, MP and drug resistance gene were detected by fluorogenic quantitative PCR.Totally, 83 cases (83.00%) were MP positive and 78 cases (93.98%) were drug resistant.All of them had the point mutations A2063G in V region of 23S rRNA domain.A total of 13 kinds of respiratory pathogens were detected by multiplex PCR method, and 89 cases (89.00%) were positive.Totally, 79 cases (79.00%) were MP positive, of which 74 cases (74.00%) detected only MP, and 5 cases (5.00%) detected MP combined with other pathogens.Other pathogens were detected in 10 cases (10.00%). The virus detection rate of 0-4 years old group was higher than that of >4-6 years old group ( P=0.042) and >6 years old group ( P=0.002), and the differences were statistically significant. Conclusions:MP can be detected in most BALF samples of MPP children, the drug resistance phenomenon is serious, and the main point mutation is A2063G.There were other respiratory pathogens and 2 or 3 pathogens were detected in a small number of BALF samples.

Objective:To explore the long-term preservation value and repair effect of normothermic machine perfusion (NMP) on clinically discarded kidneys.Methods:A case of clinical discarded donor kidney was collected, and NMP was carried out in vitro for 9 hours with recovered blood. The dynamic changes of renal appearance, blood gas and biochemistry analysis of perfusate and renal pathology were recorded. Results:In the second to fifth hour of NMP, the appearance of renal was pink and ex vivo normothermic perfusion assessment score (EVNP) was grade Ⅰ. While, the sixth hour and beyond of NMP, the appearance of kidney turned to dark red and EVNP was grade Ⅲ. The renal perfusion blood flow maintained above 150 ml/min in the first 6 hours and decreased significantly after that, and at the end, was only 50 ml/min. During the whole process of perfusion, urine output was maintained at about 100 ml/h. PO 2 remained above 100 mmHg in the first 5 hours of perfusion and from the 6th hour, was lower than 80 mmHg and continued to decline, and was close to 0 at the end of perfusion. The results showed that although the K + concentration changes in blood and urine in the first 5 hours of NMP had a good consistency, the lactic acid level had been rising. In addition, there was no significant change in the histopathology at the fourth hour of perfusion compared with that before zero-point puncture, and the fibrinous thrombus in glomeruli was improved compared with that before perfusion. However, at the sixth hour after perfusion and before the end of perfusion, the pathological changes of renal tissue were significantly worse. There were a large of thrombosis in glomerular blood vessels, renal tubular atrophy and acute tubular necrosis. Conclusions:NMP can realize the evaluation of extended criteria donors before transplantation, and it proves the feasibility and repair potential of NMP in kidney to a certain extent. At the same time, NMP also provides a new way to expand the source of donor kidney and to pre-treat organ in vitro.

【Objective】 To explore the dynamic change of depression in diabetic patients so as to provide evidence for early detection and warning of psychological problems in diabetic patients. 【Methods】 Based on the data from the China Health and Retirement Longitudinal Study （CHARLS）， the propensity score matching method was used to eliminate confounding factors in the study. The linear growth model， the nonlinear quadratic growth model， and the growth model without defined curve type were fitted respectively. According to the fitting indices of the models， the optimal solution of the growth function was determined to explore the changes of depression development in the diabetic patients. 【Results】 A total of 5 711 cases （5 380 cases in the non-diabetic group and 331 cases in the diabetic group） were included in the study. After propensity score matching， 1 621 cases （1 291 cases in the non-diabetic group and 330 cases in the diabetic group） were included and all confounding factors were balanced between the two groups. By fitting three growth curve models with latent variables， the results showed that the model without defined curve type was better than the other two models. The mean depression score for initial status in the non-diabetic and diabetic groups was 9.640 and 10.097， respectively， with significant inter-individual differences. During the follow-up period， the depression status of both groups showed a trend of decrease first and then increase， but the depression score was always lower in the non-diabetic group than in the diabetic group. At the same time， there was no individual difference in the rate of change between the two groups， and there was no statistical difference between the initial depression score and the subsequent slope of change. 【Conclusion】 Exploring the change track of depression status over time in diabetic patients， understanding the individual psychological change trend and further explaining the differences between individuals are of great significance for intervention on psychological status at different stages.

Objective:To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy.Methods:A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO′s recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics.Results:A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant ( P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% ( OR=1.42, 95% CI: 1.07-1.88, P=0.015), 46% ( OR=1.46, 95% CI: 1.13-1.88, P=0.004), and 64% ( OR=1.64, 95% CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study ( P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age ( OR=2.87, 95% CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 ( OR=1.59, 95% CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes ( OR=1.58, 95% CI: 1.18-2.13, P=0.002) and premature delivery ( OR=1.52, 95% CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM ( OR=5.34, 95% CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM ( OR=1.44, 95% CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia ( OR=4.11, 95% CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia ( OR=1.46, 95% CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery ( OR=1.47, 95% CI: 1.13-1.92, P=0.004). Conclusions:Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.