Objective To develop an ion-pairing reversed-phase high performance liquid chromatography(IP-RP-HPLC)method for the determination of L-methionine sulphoximine(MSX) residues in recombinant protein therapeutics, and to verify and preliminarily apply it, so as to provide a reference for the quality control of related products.Methods A chromatographic analysis method was screened and the mobile phase conditions such as ion-pairing reagent, pH and salt concentration were optimized to develop an IP-RP-HPLC method for the determination of MSX residues in recombinant protein therapeutics. The method was verified for specificity, system applicability, linearity, limit of detection(LOD) and limit of quantitation(LOQ), precision, accuracy and solution stability, by which the residual MSX contents in multiple batches of in-process sample and bulk of recombinant protein therapeutics were determined.Results The chromatographic conditions were determined as follows: using Hypersil GOLDTMC18 column(4. 6 mm × 250 mm, 5 μm) at column temperature of 25 ℃; 50 mmol/L sodium dihydrogen phosphate(containing 5 mmol/L sodium 1-octane sulfonate, pH 2. 0)-acetonitrile(volume fraction of 85 ∶ 15) as mobile phase for isocratic elution at a flow rate of 0. 6 mL/min; detection wavelength of 200 nm; injection volume of 50 μL. The method exhibited good specificity and system applicability. The control substance showed good linearity in the concentration range of 10-100 μg/mL, with a correlation coefficient(R) of 0. 999 95. The LOD and LOQ were 5 and 0. 5 μg/mL, respectively. MSX was not detected in either recombinant protein A or B, and the relative standard deviations(RSDs) of the measured concentrations of six parallel spiked samples were 1. 3% and 1. 1%, respectively, with the recovery rates ranged from 94% to 103%. For recombinant protein A spiked test sample placed at 10 ℃, the RSD of the measured concentrations at 0 h and 12 h were 2. 1%. MSX was not detected in the in-process samples and bulk of recombinant protein A test samples and three batches of recombinant protein B samples.Conclusion The developed IP-RP-HPLC method has the characteristics of simple operation and high sensitivity, and can be used for the quality control of MSX residues in recombinant protein therapeutics.

Donation after death is the most important ethical principle to carry out organ donation after citizens’ death. The newly-revised Regulations on Human Organ Donation and Transplantation does not define death, and avoids the key question of “whether to recognize brain death”. Certain legal risks or damages to the rights and interests of donors may exist in organ donation. Death is an inevitable part of human life. It is necessary to establish specific criteria, which is also the only approach, to define death in any era. Death criteria are established based on the view of death, and restricted by the development level of productive forces and other social factors. The determination of death criteria hugely varies between China and the West. To standardize organ donation and transplantation and promote high-quality development of organ donation, medical staff must adhere to the principle of pure motivation, take informed consents as the premise, respect the donors' and their close relatives' rights to choose their own death criteria, strictly follow the death judgment procedures and operating norms, and ensure the scientificity, accuracy and fairness of death determination.

BACKGROUND:Current studies have confirmed that Ganoderma lucidum polysaccharides can promote nerve regeneration in neurodegeneration-related diseases.The occurrence of neurodegenerative diseases is closely related to mitochondrial dysfunction,but the role of Ganoderma lucidum polysaccharides on the regulation of apoptosis and mitochondrial function in neurodegenerative diseases is not yet clarified. OBJECTIVE:To explore the regulatory effects and mechanisms of Ganoderma lucidum polysaccharides on apoptosis and mitochondrial dysfunction in H2O2-induced SH-SY5Y cells. METHODS:SH-SY5Y cells were divided into three groups:control group,H2O2 group,and Ganoderma lucidum polysaccharides group.Cells in the control group were normally cultured.Cells in the H2O2 group were treated with 300 μmol/L H2O2 for 24 hours.In the Ganoderma lucidum polysaccharides group,the intervention with 300 μg/L Ganoderma lucidum polysaccharides was conducted first for 1-2 hours,followed by the addition of 300 μmol/L H2O2 for 24 hours.The mitochondrial membrane potential was detected by JC-1 kit.Apoptosis was detected by TUNEL staining kit.The activities of malondialdehyde and superoxide dismutase were detected by malondialdehyde test kit and superoxide dismutase test kit,respectively.The apoptosis and expression of mitochondrial dynamics-related proteins were detected by immunofluorescence staining and western blot assay. RESULTS AND CONCLUSION:(1)Compared with the control group,the mitochondrial membrane potential and superoxide dismutase activity were significantly reduced,as well as apoptotic rate and malondialdehyde levels were significantly increased in the H2O2 group(P<0.05).After treatment with Ganoderma lucidum polysaccharides,the membrane potential and superoxide dismutase activities were significantly increased,and apoptotic rate and malondialdehyde levels were significantly reduced compared with the H2O2 group(P<0.05).(2)The expression levels of pro-apoptotic proteins Bax and Caspase-3 were significantly increased,but the expression of anti-apoptotic protein Bcl-2 was significantly decreased in the H2O2 group compared with the control group(P<0.05).Compared with the H2O2 group,the levels of Bax and Caspase-3 were significantly decreased,but the expression of anti-apoptotic protein Bcl-2 was significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(3)Compared with the control group,the expression of mitochondrial splitting proteins Fis1 and p-Drp1 was significantly increased,but the expression of mitochondrial fusion proteins OPA1,Mfn1,and Mfn2 was decreased in the H2O2 group(P<0.05).Compared with the H2O2 group,Fis1 and p-Drp1 expression was significantly reduced,but the expression levels of OPA1,Mfn1,and Mfn2 were significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(4)The above results confirm that Ganoderma lucidum polysaccharides can attenuate H2O2-induced oxidative stress damage and apoptosis in SH-SY5Y cells by ameliorating mitochondrial dysfunction.

Objective:To explore the microbiological and disease distribution characteristics of multidrug-resistant bacteria in patients hospitalized in a critical care rehabilitation ward, and to analyze the risk factors leading to multidrug-resistant bacterial infections.Methods:Microbiology screening data describing 679 patients admitted to a critical care rehabilitation ward were retrospectively analyzed to divide the subjects into a multidrug-resistant group (positive for multidrug-resistant bacterial infections, n=166) and a non-multidrug-resistant group (negative for multidrug-resistant bacterial infections, n=513). The risk factors were then analyzed using logistic regression. Results:Among 369 strains of multidrug-resistant bacteria observed, 329 were gram-negative bacteria (89.2%), mainly Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. They were distributed in sputum (56.9%) and mid-epidemic urine (28.2%) specimens. Patients whose primary disease was hemorrhagic or ischemic cerebrovascular disease accounted for 40.96% and 23.49% of the multidrug-resistant bacterial infections, respectively. Logistic regression analysis showed that albumin level, dependence on mechanical ventilation, central venous cannulation, or an indwelling urinary catheter or cystostomy tube were significant independent predictors of such infections.Conclusion:The multidrug-resistant bacterial infections of patients admitted to the critically ill rehabilitation unit are mainly caused by gram-negative bacteria. Their occurrence is closely related to low albumin levels and mechanical ventilation, as well as to bearing an indwelling central venous catheter, a urinary catheter or a cystostomy catheter.

Objective:To investigate clinical curative effect of multiple composite tissues replantation with microsurgical technique in single hand.Methods:From May 2008 to December 2021, the clinical data of patients who underwent multiple composite tissue replantation in single hand in Chongming Hospital Affiliated to Shanghai University of Medicine & Health Sciences and Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, were retrospectively analyzed. According to the severed site, anatomical level, the injury cause, the severity of injury, the size of severed tissue, and replantation conditions (such as blood vessels for anastomosis), the severed tissue was evaluated and carried out modified classification (type Ⅰ-Ⅳ) before the operation, and the surgical plan was designed. The severed composite tissue was debrided in emergency, the severed bone and muscle tissue were fixed, and the arteries, veins and nerves were anastomosed by microsurgical technique under a high-power microscope. The ratio of arteries to veins was 1∶1-1∶2. If enough arteries and veins could not be found, arteriovenous shunt could be used to form arterial venous flap or venous arterialized flap, or form artery flap by just artery anastomosis, or form venous flap by just vein anastomosis. Then skin tissue was sutured after recanalization. After the operation, the patients received specialized treatment and guided rehabilitation exercise. The wound healing of hand, skin color, skin quality, swelling degree, sensation, pain degree of joint, and activity function were followed up after the operation. At the last follow-up, the patient’s self-evaluation of the treatment effect was divided into three levels: satisfactory, average, and unsatisfactory. One chief physician and one doctor-in-charge were responsible for the comprehensive evaluation of curative effect, according to the assessment standard for upper limb function issued by Chinese Medical Association of Hand Surgery. 80-100 points were excellent, 60-79 points were good, 40-59 points were fair, and <40 points were poor.Results:A total of 94 severed composite tissues in 35 patients, including of 20 male patients and 15 female patients were enrolled. The average age was 36.4 years (range, 16-65 years). Fifty severed tissues in 18 cases were classified into type Ⅰ, 40 severed tissues in 15 cases type Ⅱ, 4 severed tissues in 2 cases type Ⅲ. Among the 35 cases, 1 case of thumb pulp severed tissue was necrotic at the edge (0.3 cm×0.5 cm) due to local contusion, 1 case of index finger lateral severed tissue was necrotic at the edge (0.3 cm×0.8 cm) due to local avulsion injury, and healed after dressing change, and the other replanted composite tissue survived. The patients were followed up for 3 to 65 months (average, 18.5 months). The wounds were completely healed, and the color, elasticity, and quality of the replanted tissue was close to the surrounding normal skin. There was no obvious swelling or atrophy deformity of the hands. According to the patients’ self-assessment, 31 cases were satisfied and 4 cases were average. Comprehensive evaluation of hand function and appearance: excellent in 23 cases, good in 9 cases, fair in 3 cases, excellent and good rate was about 91.4% (32/35).Conclusion:Though multiple composite tissues replantation with microsurgical technique in single hand is difficult, and vascular anastomosis technical requirement is high, once surgery succeeds, the function and appearance can get good recovery, and patient satisfaction is also relatively high.

Objective:To understand the major cognition, major choice motivation and the relationship between the two of medical students, and provide references and suggestions for the selection of talents in various majors of medical schools and the effective development of enrollment work.Methods:This study selected undergraduates of Batch 2019 from Peking University Health Science Center as the survey objects, conducted a questionnaire survey on their major cognition, major choice motivation and influencing factors, and used principal component analysis and Spearman rank correlation analysis.Results:The study found that the major cognition scores of 640 undergraduates of Batch 2019 from Peking University Health Science Center were clinical medicine (3.24±0.89) > stomatology (2.89±1.00) > basic medicine (2.66±1.02) > pharmacy (2.54±0.97) > preventive medicine (2.29±0.93) > nursing medicine (2.21±0.99) > medical laboratory (1.98±0.95) > medical English (1.95±0.93). Six major motivation factors for professional choice were school and professional strength, professional learning and job prospects, own factors, Peking University sentiments and the influence of others, medical factors, school policies, and the contribution rates were 34.60%, 12.97%, 7.42%, 6.00%, 5.59% and 5.37%, respectively. Major cognition scores and major choice motivation factors were positively correlated with each other to some extent.Conclusions:At present, students' major cognition level of medical majors still has a large room for improvement, and the motivational factors of major choice are more complicated, among which "the school and professional strength" and "the prospects of study and work" are important factors. Medical schools should focus on strengthening major publicity, improving students' major cognition, attracting aspiring students to apply for medical majors from many aspects, and improving the training quality of medical professionals.

Objective To identify clinical risk factors for early major adverse cardiovascular events (MACEs) following surgical correction of supravalvar aortic stenosis (SVAS). Methods Patients who underwent SVAS surgical correction between 2002 and 2019 in Beijing and Yunnan Fuwai Cardiovascular Hospitals were included. The patients were divided into a MACEs group and a non-MACEs group based on whether MACEs concurring during postoperative hospitalization or within 30 days following surgical correction for SVAS. Their preoperative, intraoperative, and postoperative clinical data were collected for multivariate logistic regression. Results This study included 302 patients. There were 199 males and 103 females, with a median age of 63.0 (29.2, 131.2) months. The incidence of early postoperative MACEs was 7.0% (21/302). The multivariate logistic regression model identified independent risk factors for early postoperative MACEs, including ICU duration (OR=1.01, 95%CI 1.00-1.01, P=0.032), intraoperative cardiopulmonary bypass (CPB) time (OR=1.02, 95%CI 1.01-1.04, P=0.014), aortic annulus diameter (OR=0.65, 95%CI 0.43-0.97, P=0.035), aortic sinus inner diameter (OR=0.75, 95%CI 0.57-0.98, P=0.037), and diameter of the stenosis (OR=0.56, 95%CI 0.35-0.90, P=0.016). Conclusion The independent risk factors for early postoperative MACEs include ICU duration, intraoperative CPB time, aortic annulus diameter, aortic sinus inner diameter, and diameter of the stenosis. Early identification of high-risk populations for MACEs is beneficial for the development of clinical treatment strategies.

Objective This paper investigates the effect of a multi-physical field fusion intervention based on transcranial direct current stimulation(tDCS),transcranial magnetic stimulation(TMS)and music on mental fatigue.Methods After fatigue induction,10 subjects received blank group stimulation,music group stimulation and tDCS-TMS-Music stimulation,respectively.tDCS stimulation sites were located in the bilateral frontal regions of the subjects,and TMS stimulation sites were located in the bilateral occipital regions of the hindbrain.Heart rate variability and reaction performance were measured before and after each intervention to determine the elimination effect of different intervention programs on mental fatigue.Results Compared with the control group,the tDCS-TMS-Music group showed significantly greater improvements in subjective mental workload,response performance,and heart rate variability.Conclusion The results of this study support that tDCS-TMS-Music can effectively alleviate mental fatigue induced by long-term cognitive performance tasks,and the intervention effect is better than music intervention and resting-state relief at the same time.

Objective:To investigate clinical curative effect of multiple composite tissues replantation with microsurgical technique in single hand.Methods:From May 2008 to December 2021, the clinical data of patients who underwent multiple composite tissue replantation in single hand in Chongming Hospital Affiliated to Shanghai University of Medicine & Health Sciences and Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, were retrospectively analyzed. According to the severed site, anatomical level, the injury cause, the severity of injury, the size of severed tissue, and replantation conditions (such as blood vessels for anastomosis), the severed tissue was evaluated and carried out modified classification (type Ⅰ-Ⅳ) before the operation, and the surgical plan was designed. The severed composite tissue was debrided in emergency, the severed bone and muscle tissue were fixed, and the arteries, veins and nerves were anastomosed by microsurgical technique under a high-power microscope. The ratio of arteries to veins was 1∶1-1∶2. If enough arteries and veins could not be found, arteriovenous shunt could be used to form arterial venous flap or venous arterialized flap, or form artery flap by just artery anastomosis, or form venous flap by just vein anastomosis. Then skin tissue was sutured after recanalization. After the operation, the patients received specialized treatment and guided rehabilitation exercise. The wound healing of hand, skin color, skin quality, swelling degree, sensation, pain degree of joint, and activity function were followed up after the operation. At the last follow-up, the patient’s self-evaluation of the treatment effect was divided into three levels: satisfactory, average, and unsatisfactory. One chief physician and one doctor-in-charge were responsible for the comprehensive evaluation of curative effect, according to the assessment standard for upper limb function issued by Chinese Medical Association of Hand Surgery. 80-100 points were excellent, 60-79 points were good, 40-59 points were fair, and <40 points were poor.Results:A total of 94 severed composite tissues in 35 patients, including of 20 male patients and 15 female patients were enrolled. The average age was 36.4 years (range, 16-65 years). Fifty severed tissues in 18 cases were classified into type Ⅰ, 40 severed tissues in 15 cases type Ⅱ, 4 severed tissues in 2 cases type Ⅲ. Among the 35 cases, 1 case of thumb pulp severed tissue was necrotic at the edge (0.3 cm×0.5 cm) due to local contusion, 1 case of index finger lateral severed tissue was necrotic at the edge (0.3 cm×0.8 cm) due to local avulsion injury, and healed after dressing change, and the other replanted composite tissue survived. The patients were followed up for 3 to 65 months (average, 18.5 months). The wounds were completely healed, and the color, elasticity, and quality of the replanted tissue was close to the surrounding normal skin. There was no obvious swelling or atrophy deformity of the hands. According to the patients’ self-assessment, 31 cases were satisfied and 4 cases were average. Comprehensive evaluation of hand function and appearance: excellent in 23 cases, good in 9 cases, fair in 3 cases, excellent and good rate was about 91.4% (32/35).Conclusion:Though multiple composite tissues replantation with microsurgical technique in single hand is difficult, and vascular anastomosis technical requirement is high, once surgery succeeds, the function and appearance can get good recovery, and patient satisfaction is also relatively high.

Objectives:To investigate the association between normal-weight central obesity with new-onset cardiovascular disease and all-cause mortality risk. Methods:A prospective cohort study was conducted,selecting a total of 93885 participants from the Kailuan Study who had their first physical examination in 2006-2007.According to waist circumference (central obesity:male waist circumference ≥90 cm,female waist circumference ≥85 cm;no central obesity:male waist circumference<90 cm,female waist circumference<85 cm) and body mass index (BMI,normal weight:18.5 kg/m2≤BMI<24.0 kg/m2;overweight/obesity:BMI ≥24.0 kg/m2),the participants were divided into 4 groups:normal weight no central obesity group (G1 group),normal weight central obesity group (G2 group),overweight/obesity no central obesity group (G3 group) and overweight/central obesity group (G4 group);Using the Kaplan-Meier method,the cumulative incidence of new-onset cardiovascular diseases (including hemorrhagic stroke,ischemic stroke and myocardial infarction) and all-cause mortality in different groups was calculated,and the Log-rank test was used for intergroup comparisons.Furthermore,the associations between the different groups and the risk of new-onset cardiovascular diseases and all-cause mortality were analyzed using the multivariate Cox proportional hazard regression model. Results:After a median follow-up of 14.97 (14.55,15.17) years,the cumulative incidence of new-onset cardiovascular diseases in G1 group,G2 group,G3 group and G4 group was 7.62％,10.84％,8.67％,12.91％ respectively (log-rank P<0.05) and the cumulative incidence of all-cause mortality was 12.83％,19.72％,10.65％,16.33％ respectively (log-rank P<0.01).After adjusting for confounding factors,Cox regression analysis showed that the HR (95％CI) of new-onset cardiovascular diseases in G2 group,G3 group and G4 group were 1.14 (1.04-1.25),1.07 (1.01-1.14),1.27 (1.21-1.34),respectively compared with G1 group (all P<0.05).The HR (95％CI) of all-cause mortality were 1.06 (1.00-1.14),0.90 (0.85-0.95),0.97 (0.93-1.01) compared with G1 group,and P values were 0.07,<0.01,0.15,respectively.The results of sensitivity analysis were consistent with the above major studies after excluding overweight/obesity and cancer participants during follow-up. Conclusions:Normal-weight central obesity increases the risk of new-onset cardiovascular diseases and all-cause mortality.