Phenylpyruvic acid (PPA) is used as a food and feed additive and has a wide range of applications in the pharmaceutical, chemical and other fields. At present, PPA is mainly produced by chemical synthesis. With the green transformation of the manufacturing industry, biotransformation will be a good alternative for PPA production. The L-amino acid deaminase (PmiLAAD) from Proteus mirabilis has been widely studied for the production of PPA. However, the low yield limits its industrial production. To further enhance the production of PPA and better meet industrial demands, a more efficient synthesis method for PPA was established. In this study, PmiLAAD was heterologously expressed in Escherichia coli. Subsequently, a colorimetric reaction method was established to screen the strains with high PPA production. The semi-rational design of PmiLAAD was carried out, and the obtained triple-site mutant V18 (V437I/S93C/E417A) showed a 35% increase in catalytic activity compared with the wild type. Meanwhile, the effect of N-terminal truncation on the catalytic activity of the V18 mutant was investigated. After the optimization of the whole-cell conditions for the obtained mutant V18-N7, fed-batch conversion was carried out in a 5-L fermenter, and 44.13 g/L of PPA was synthesized with a conversion rate of 88%, which showed certain potential for industrial application. This study lays foundation for the industrial production of phenylpyruvic acid and also offers insights into the biosynthesis of other chemicals.
Escherichia coli/metabolism* ; Proteus mirabilis/genetics* ; Phenylpyruvic Acids/metabolism* ; Protein Engineering/methods* ; Recombinant Proteins/biosynthesis* ; Bacterial Proteins/metabolism*

Eating disorders(ED) are a group of psychiatric disorders related to abnormal eating behaviors, with complex and variable symptoms, frequent crossover of diagnoses among various subtypes, high comorbidity rates, and often difficulties in medical treatment, which seriously affect the quality of life of patients. Understanding ED from a transdiagnostic perspective provides new ideas for treatment. According to the theory of cognitive behavioral therapy, psychological cognitive development is an important maintenance mechanism for the transdiagnosis of ED. Core beliefs, as the deepest level of psychological cognition, play an important role in the development and maintenance of ED. A large number of studies have found that among patients with various subtypes of ED, the core beliefs related to the self involve body shape and weight, achievement/worth, sense of control, and the core beliefs related to the world/others involve unloveability and abandonment influence both eating-related symptoms and comorbidity levels. For the first time, this paper focuses on sorting out the transdiagnostic core beliefs of patients with ED and further clarifying the relationship between transdiagnostic core beliefs and ED symptoms, in order to better understand, prevent and treat ED, then promote recovery and reduce relapse.

Eating disorders(ED) are a group of psychiatric disorders related to abnormal eating behaviors, with complex and variable symptoms, frequent crossover of diagnoses among various subtypes, high comorbidity rates, and often difficulties in medical treatment, which seriously affect the quality of life of patients. Understanding ED from a transdiagnostic perspective provides new ideas for treatment. According to the theory of cognitive behavioral therapy, psychological cognitive development is an important maintenance mechanism for the transdiagnosis of ED. Core beliefs, as the deepest level of psychological cognition, play an important role in the development and maintenance of ED. A large number of studies have found that among patients with various subtypes of ED, the core beliefs related to the self involve body shape and weight, achievement/worth, sense of control, and the core beliefs related to the world/others involve unloveability and abandonment influence both eating-related symptoms and comorbidity levels. For the first time, this paper focuses on sorting out the transdiagnostic core beliefs of patients with ED and further clarifying the relationship between transdiagnostic core beliefs and ED symptoms, in order to better understand, prevent and treat ED, then promote recovery and reduce relapse.

Objective:To explore the challenges in the implementation of drug centralized volume-based procurement policies in hospitals and propose corresponding optimization suggestions.Methods:From August to December 2023, a purposive sampling was conducted to select 11 pharmaceutical experts from tertiary hospitals in China for Delphi method. The survey content included " policy recommendations for promoting the acceleration and expansion of national drug centralized procurement and retaining surplus medical insurance funds for centralized procurement" .Results:Survey participants gave feedback on a set of existing problems found in the implementation of drug centralized procurement policies and proposed corresponding optimization methods. Kendall′s W coefficient of the specialist consultation was 0.332( P<0.05), demonstrating good consistency and concentration of the expert opinions. Among the problems, the score of drug supply guarantee was the highest(mean value of importance was 4.45). At the same time, the recommendation of strengthening monitoring and early warning, coordination and dispatch, and effectively ensuring the supply of centralized drug procurement had the highest score and concentration(mean value of importance was 4.91, coefficient of variation was 0.06). Conclusions:Through Delphi method, this study revealed issues and optimization methods in the implementation of drug centralized procurement policies in hospitals. The findings could provide valuable insights for improvements in the pharmaceutical sector and future policy adjustments.

Objective:To summarize the construction and practice of the compulsory postgraduate course "reproductive genetics in gynecology and obstetrics" in Department of Gynecology and Obstetrics, Peking University, and to evaluate the teaching effect of this course.Methods:A total of 139 postgraduates who studied in Department of Obstetrics and Gynecology, Peking University, from 2019 to 2021 were enrolled as subjects, and a syllabus was constructed through a top-level design based on the "biological-psychological-social medicine pattern", with the teaching objectives of reproductive genetics theory, clinical translation, genetic counseling methods, and research advances. The teaching effect was evaluated by analyzing teaching assessment results, teaching evaluation feedback, and teaching achievements. SPSS 26.0 software was used to perform the t-test and the chi-square test. Results:The written test score, usual performance score, and total score of the postgraduate students in 2021 were higher than those in 2019 and 2020 [(73.50±8.19) vs. (70.94±14.90); (68.60±2.82) vs. (68.22±4.58); (90.58±4.18) vs. (89.49±7.60)], with significant differences in written test score and total score ( P<0.05). There was a high degree of satisfaction with the feedback of teaching, and 85.61% (119/139) of the students selected "great satisfaction"; in particular, there were increases in the degree of satisfaction with expanding research ideas and reflecting the advances in this discipline, but with no significant difference. There was a significant increase in the number of published articles. Conclusion:For the active implementation of the course of "Reproductive Genetics in Obstetrics and Gynecology", improving the teaching process in a planned and step-by-step way through a top-level design in advance can help to expand research ideas for future research work among postgraduates in obstetrics and gynecology and promote the sustainable development and improvement of the teaching of the emerging interdisciplinary discipline of reproductive genetics in obstetrics and gynecology.

Objective:To explore the characteristics of ovarian torsion in in vitro fertilization-embryo transfer (IVF-ET) cycles and identify factors that may affect the outcome. Methods:Patients who underwent surgery for ovarian torsion during IVF treatment in the Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital from January 2010 to December 2019 were included. The general information, IVF cycle characteristics, and intraoperative findings of patients were retrospectively analyzed. The diagnosis and treatment process were summarized. The pregnancy outcomes were followed up, and the possible influencing factors were analyzed.Results:There were 141 539 cycles of controlled ovarian stimulation (COS) and 75 585 cycles of frozen-thawed embryo transfer (FET) during the study period. A total of 50 patients were diagnosed with ovarian torsion and treated surgically, 90.0% of them occurred in the COS cycles (39 cases in fresh embryo transfer cycles and 6 cases in embryo freezing cycles), and 10.0% (5/50) occurred in the FET cycles (endometrial preparation in natural cycles or ovulation induction cycles). About 86.0% (43/50) of the patients occurred during pregnancy assisted with IVF-ET and 81.4% (35/43) occurred in the first trimester of pregnancy. All patients except one had abdominal pain as the first symptom, only 34.0% (17/50) of the patients had definite inducements, and all patients had signs of tenderness in the lower abdomen and adnexal area. Preoperative ultrasound examination showed that the average diameter of the torsional ovaries was (78.17±15.98) mm, compared with (48.69±15.96) mm in the controls, with an average difference of (30.13±19.69) mm (-3.5-80.0 mm). About 76.2% (32/42) of the torsional ovaries showed blood flow signals by color doppler ultrasound. All patients underwent surgery, and the coincidence rate between the preoperative diagnosis and the surgical diagnosis was 96%. Totally 22 torsional ovaries (44%) were found to be purplish-black, of which 16 cases underwent adnexectomy by laparoscopy or laparotomy. Totally 34 cases (68%) underwent ovarian detorsion. The average torsional degree of ovaries in the adnexectomy group was higher than that in the ovarian detorsion group [(727.50±206.54)° vs. (477.35±262.92)°, P=0.002]. There were no statistical differences between the two groups in the duration from onset to operation and the ratio of ovarian blood signal deficiency (all P>0.05). Among 44 patients with the embryo transfer, 84.1% (37/44) of patients obtained live birth, 1 case had implantation failure, and 6 cases had a spontaneous abortion. Patients with an adverse pregnancy outcome and patients with a live birth did not have significantly different ovarian torsion time, surgical methods, the duration from onset to operation, and other factors. Conclusion:Ovarian torsion in patients with IVF-ET treatment mostly occurs in the first trimester of pregnancy after fresh embryo transfer. Abdominal pain accompanied by differential enlargement of bilateral ovaries may suggest the possibility of ovarian torsion. We are unable to rule out ovarian torsion by observation of ovarian blood flow with color Doppler ultrasound. Active surgery was helpful to make a clear diagnosis and protect the fertility of patients. Patients with long torsional durations, purplish-black ovaries, or ovarian blood deficiency still have the opportunity to retain the torsional ovary. The pregnancy outcome of patients with ovarian torsion was satisfactory after surgical treatment.

Objective:To explore the feasibility and effective methods of obtaining immature oocytes during laparoscopic ovarian tissue resection in female tumor patients, aiming at oocytes freezing matured in vitro for fertility preservation. Methods:Retrospective analysis was made on the general data, surgical methods and postoperative follow-up data of 22 tumor patients who underwent laparoscopic ovarian tissue resection at the Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital from November 2015 to April 2022. The study group included 14 patients who simultaneously obtained in vitro maturation (IVM) of immature eggs during laparoscopy. Control group included 8 patients who only underwent cortical resection. The operation time, the amount of bleeding, the number of frozen cortex and other data of the two groups were analyzed to evaluate the application value and safety of this method. Furtherly, the study group was divided into two subgroups, the transvaginal egg retrieval subgroup (10 patients) and the translaparoscopic egg retrieval subgroup (4 patients), according to the method of different methods used for egg retrieval. The time of surgery, the number of eggs obtained and the number of frozen cortices were analyzed in both subgroups to evaluate the efficiency of the different methods of egg retrieval. All 22 patients were followed up annually after surgery, analyzing the information of tumor treatment, menstrual status, and if possible, pelvic ultrasound and sex hormone levels, recording ovarian function after tumor treatment in these patients and providing hormone replacement therapy (HRT) within the indications. Results:There were no statistically significant differences between the study group and control group in terms of age, duration of disease, anti-Müllerian hormone (AMH) level, and the number of frozen cortices. But the number of basal sinus follicles (19.71±6.04), procedure time [(68.07±17.35) min], and bleeding volume [9.0 (5.0,10.5) mL] in the study group were higher than those in control group with statistically significant differences [9.25±3.15, P<0.001; (44.25±16.97) min, P=0.005; 3.5 (2.0, 5.0) mL, P=0.001]. In the transvaginal egg retrieval subgroup, the number of oocytes obtained [15.5 (11.0, 21.0)] and age [(27.00±2.94) years] were significantly higher than those in the translaparoscopic egg retrieval subgroup [4.0 (0.8, 10.3), P=0.028;(15.75±2.22) years, P<0.001], while no statistically significant differences were observed between the two subgroups in the number of sinus follicles, time to surgery, and number of frozen cortices. All 7 patients who underwent hematopoietic stem cell transplantation (HSCT) had amenorrhea after discharge, and were given HRT after disease remission, and their physical development and quality of life were maintained and improved. Conclusion:Young oncology patients who underwent ovarian cortical resection with simultaneous acquisition of immature eggs, in vitro matured oocytes freezing increased the chance of fertility preservation. The efficiency of transvaginal acquisition of immature oocytes was higher; the rate of amenorrhea after HSCT was high, and HRT could improve the quality of life of patients.

Objective:To explore the characteristics of ovarian torsion in in vitro fertilization-embryo transfer (IVF-ET) cycles and identify factors that may affect the outcome. Methods:Patients who underwent surgery for ovarian torsion during IVF treatment in the Center of Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital from January 2010 to December 2019 were included. The general information, IVF cycle characteristics, and intraoperative findings of patients were retrospectively analyzed. The diagnosis and treatment process were summarized. The pregnancy outcomes were followed up, and the possible influencing factors were analyzed.Results:There were 141 539 cycles of controlled ovarian stimulation (COS) and 75 585 cycles of frozen-thawed embryo transfer (FET) during the study period. A total of 50 patients were diagnosed with ovarian torsion and treated surgically, 90.0% of them occurred in the COS cycles (39 cases in fresh embryo transfer cycles and 6 cases in embryo freezing cycles), and 10.0% (5/50) occurred in the FET cycles (endometrial preparation in natural cycles or ovulation induction cycles). About 86.0% (43/50) of the patients occurred during pregnancy assisted with IVF-ET and 81.4% (35/43) occurred in the first trimester of pregnancy. All patients except one had abdominal pain as the first symptom, only 34.0% (17/50) of the patients had definite inducements, and all patients had signs of tenderness in the lower abdomen and adnexal area. Preoperative ultrasound examination showed that the average diameter of the torsional ovaries was (78.17±15.98) mm, compared with (48.69±15.96) mm in the controls, with an average difference of (30.13±19.69) mm (-3.5-80.0 mm). About 76.2% (32/42) of the torsional ovaries showed blood flow signals by color doppler ultrasound. All patients underwent surgery, and the coincidence rate between the preoperative diagnosis and the surgical diagnosis was 96%. Totally 22 torsional ovaries (44%) were found to be purplish-black, of which 16 cases underwent adnexectomy by laparoscopy or laparotomy. Totally 34 cases (68%) underwent ovarian detorsion. The average torsional degree of ovaries in the adnexectomy group was higher than that in the ovarian detorsion group [(727.50±206.54)° vs. (477.35±262.92)°, P=0.002]. There were no statistical differences between the two groups in the duration from onset to operation and the ratio of ovarian blood signal deficiency (all P>0.05). Among 44 patients with the embryo transfer, 84.1% (37/44) of patients obtained live birth, 1 case had implantation failure, and 6 cases had a spontaneous abortion. Patients with an adverse pregnancy outcome and patients with a live birth did not have significantly different ovarian torsion time, surgical methods, the duration from onset to operation, and other factors. Conclusion:Ovarian torsion in patients with IVF-ET treatment mostly occurs in the first trimester of pregnancy after fresh embryo transfer. Abdominal pain accompanied by differential enlargement of bilateral ovaries may suggest the possibility of ovarian torsion. We are unable to rule out ovarian torsion by observation of ovarian blood flow with color Doppler ultrasound. Active surgery was helpful to make a clear diagnosis and protect the fertility of patients. Patients with long torsional durations, purplish-black ovaries, or ovarian blood deficiency still have the opportunity to retain the torsional ovary. The pregnancy outcome of patients with ovarian torsion was satisfactory after surgical treatment.

Objective:To explore the feasibility and effective methods of obtaining immature oocytes during laparoscopic ovarian tissue resection in female tumor patients, aiming at oocytes freezing matured in vitro for fertility preservation. Methods:Retrospective analysis was made on the general data, surgical methods and postoperative follow-up data of 22 tumor patients who underwent laparoscopic ovarian tissue resection at the Center for Reproductive Medicine, Department of Obstetrics and Gynecology, Peking University Third Hospital from November 2015 to April 2022. The study group included 14 patients who simultaneously obtained in vitro maturation (IVM) of immature eggs during laparoscopy. Control group included 8 patients who only underwent cortical resection. The operation time, the amount of bleeding, the number of frozen cortex and other data of the two groups were analyzed to evaluate the application value and safety of this method. Furtherly, the study group was divided into two subgroups, the transvaginal egg retrieval subgroup (10 patients) and the translaparoscopic egg retrieval subgroup (4 patients), according to the method of different methods used for egg retrieval. The time of surgery, the number of eggs obtained and the number of frozen cortices were analyzed in both subgroups to evaluate the efficiency of the different methods of egg retrieval. All 22 patients were followed up annually after surgery, analyzing the information of tumor treatment, menstrual status, and if possible, pelvic ultrasound and sex hormone levels, recording ovarian function after tumor treatment in these patients and providing hormone replacement therapy (HRT) within the indications. Results:There were no statistically significant differences between the study group and control group in terms of age, duration of disease, anti-Müllerian hormone (AMH) level, and the number of frozen cortices. But the number of basal sinus follicles (19.71±6.04), procedure time [(68.07±17.35) min], and bleeding volume [9.0 (5.0,10.5) mL] in the study group were higher than those in control group with statistically significant differences [9.25±3.15, P<0.001; (44.25±16.97) min, P=0.005; 3.5 (2.0, 5.0) mL, P=0.001]. In the transvaginal egg retrieval subgroup, the number of oocytes obtained [15.5 (11.0, 21.0)] and age [(27.00±2.94) years] were significantly higher than those in the translaparoscopic egg retrieval subgroup [4.0 (0.8, 10.3), P=0.028;(15.75±2.22) years, P<0.001], while no statistically significant differences were observed between the two subgroups in the number of sinus follicles, time to surgery, and number of frozen cortices. All 7 patients who underwent hematopoietic stem cell transplantation (HSCT) had amenorrhea after discharge, and were given HRT after disease remission, and their physical development and quality of life were maintained and improved. Conclusion:Young oncology patients who underwent ovarian cortical resection with simultaneous acquisition of immature eggs, in vitro matured oocytes freezing increased the chance of fertility preservation. The efficiency of transvaginal acquisition of immature oocytes was higher; the rate of amenorrhea after HSCT was high, and HRT could improve the quality of life of patients.

【Objective】 To explore the correlation between red blood cell lifespan and adhesion molecules on the surface of red blood cell membrane, in order to establish a method to detect the duration of red blood cell storage. 【Methods】 10 samples(10 mL each) of fresh red blood cell, collectedf rom 10 healthy voluntary blood donors, were divided into 5 age groups (layers) by Percoll density gradient centrifugation. The expression of CD47, CD44 and CD147 on the surface of red blood cell membrane in each layer was detected using flow cytometry. The variance of protein expression in each layer of red blood cells was analyzed by SPSS statistical software. 【Results】 The expression levels (%) of 3 adhesion molecules on the surface of red blood cell membranes from young to old were CD47: 14.44±2.61, 9.30±1.75, 7.84±1.49, 6.54±1.32 and 5.53±1.12 (P<0.01); CD44: 25.01±1.94, 19.22±1.52, 17.10±1.28, 15.18±1.11 and 13.56±1.08 (P<0.01); CD147: 33.46±1.99, 28.31±2.95, 23.83±1.59, 20.40±1.56 and 18.03±1.65 (P<0.01). 【Conclusion】 The expression levels of CD47, CD44 and CD147 on the surface of red blood cell membranes have showed a downward trend as the storage extended. These three protein adhesion molecules have showed a correlation with red blood cells lifespan, and could be used as detection markers of cell age.