Humans ; COVID-19 ; HIV Infections/drug therapy* ; Risk Factors

Abstract Plant exocrine-like nanovesicles(PELNs) is a new nano-therapeutic agent and delivery platform, which not only has the potential for disease treatment, but also can be used as a drug carrier to target disease sites and play a dual role in treatment and delivery. More importantly, PELNs has the characteristics of green nature and low immunogenicity. This review systematically introduced several secretory mechanisms of PELNs:Outer capsule positive organelle, polyvesicular body, vacuole and autophagosome; three components such as lipid, protein and nucleic acid; centrifugation, ultrafiltration, size exclusion chromatography, flow field-flow fractionation, immunomagnetic beads, polymer precipitation and other separation methods and their biological functions such as anti-inflammation, anti-tumor, protection of regeneration, antivirus, liver protection, etc.; sorted out the potential mechanism of PELNs as a therapeutic agent and molecular delivery platform, and put forward the problems existing in the research process of PELNs, such as quantification, mechanism research and few clinical trials. And its development potential in the future is discussed.

Seed quality plays an important role in the agricultural and animal husbandry production, the effective utilization of genetic resources, the conservation of biodiversity and the restoration and reconstruction of plant communities. Seed aging is a common physiological phenomenon during storage. It is a natural irreversible process that occurs and develops along with the extension of seed storage time. It is not only related to the growth, yield and quality of seed and seedling establishment, but also has an important effect on the conservation, utilization and development of plant germplasm resources. The physiological mechanisms of seed aging are complex and diverse. Most studies focus on conventional physiological characterization, while systematic and comprehensive in-depth studies are lacking. Here we review the recent advances in understanding the physiology of seed aging process, including the methods of seed aging, the effect of aging on seed germination, and the physiological and molecular mechanisms of seed aging. The change of multiple physiological parameters, including seed vigor, electrical conductivity, malondialdehyde content and storage material in the seed, antioxidant enzyme activity and mitochondrial structure, were summarized. Moreover, insights into the mechanism of seed aging from the aspects of transcriptome, proteome and aging related gene function were summarized. This study may facilitate the research of seed biology and the conservation and utilization of germplasm resources.
Germination ; Plants ; Proteome ; Seedlings ; Seeds/genetics*

Objective:To investigate the clinical value of stylized laparoscopic hemicolec-tomy for left colon cancer.Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 174 patients who underwent laparoscopic hemicolectomy for left colon cancer in the First Affiliated Hospital of Nanjing Medical University from January 2016 to December 2020 were collected. There were 106 males and 68 females, aged 59(range, 17?86)years. All patients underwent stylized laparoscopic hemicolectomy for left colon cancer. Observation indicators: (1) surgical situations; (2) postoperative complications; (3) postoperative histopathological examinations; (4) follow-up. Follow-up was conducted using outpatient examination or telephone interview to detect tumor recurrence and metastasis and survival of patients up to October 2021. Follow-up was performed once every 3 months within postoperative 2 years, once every 6 months within postoperative 2 to 5 years and once a year after postoperative 5 years, with the end point as tumor recurrence and metastasis or death of patients. Measurement data with normal distribution were represented as Mean±SD and measurement data with skewed distribution were represented as M(range) or M( Q1, Q3). Count data were described as absolute numbers or percentages. Kaplan-Meier method was used to draw survival curve and calculate survival rate. Results:(1) Surgical situations. All the 174 patients underwent stylized laparoscopic hemicolectomy for left colon cancer successfully, including 6 cases receiving preoperative enteral stent placement due to bowel obstruc-tion, 3 cases receiving defunctioning ileostomy and 1 case receiving Hartmann procedure. The operation time, volume of intraoperative blood loss, time to postoperative initial defecation and duration of postoperative hospital stay of the 174 patients were 97(80,106)minutes, 45(25,60)mL, 5(3,6)days and 7(6,8)days, respectively. (2) Postoperative complications. Twelve of the 174 patients had complications, including 4 cases with incision infection or fat liquefaction, 3 cases with anastomotic leakage, 2 cases with incomplete bowel obstruction, 1 case with abdominal hemo-rrhage, 1 case with chylous leakage and 1 case with pulmonary infection. The 2 cases with anastomotic leakage underwent ileostomy. The patient with abdominal hemorrhage underwent laparotomy to stop bleeding. One elder patient died of postoperative pulmonary infection. The other patients with complications recovered with conservative treatment. (3) Postoperative histopatho-logical examinations. Of the 174 patients, there were 27 cases in stage Ⅰ of TNM staging, 68 cases in stage Ⅱ, 77 cases in stage Ⅲ and 2 cases in stage Ⅳ. There were 9 cases with well differentiated tumor, 107 cases with moderately differentiated tumor and 58 cases with poorly differentiated tumor. The number of lymph node detected, the number of positive lymph node and tumor diameter of the 174 patients were 19(15,23), 0(0,2) and 4(3,5)cm, respectively. Of the 174 patients, there were 79 cases with lymph node metastases, 21 cases with cancerous nodules, 35 cases with vascular invasion and 29 cases with nerve invasion. (4) Follow-up. Of the 174 patients, 157 cases were followed up for 27(range, 1?70)months. Of the 157 patients who conducted follow-up, 20 cases had tumor metastasis, including 9 cases with multiple metastasis, 5 cases with liver metastasis, 4 cases with lung metastasis, 1 case with bone metastasis and 1 case with spleen metastasis. The 5-year overall survival rate and tumor free survival rate of the 157 patients were 90.9% and 80.8%, respectively.Conclusion:The stylized laparoscopic hemicolectomy for left colon cancer is safe and feasible.

Objective:To investigate the characteristics of No.253 lymph node metastasis in middle and low rectal cancer and its influencing factors.Methods:The retrospective case-control study was conducted. The clinicopathological data of 2 316 patients with middle and low rectal cancer who were admitted to the First Affiliated Hospital of Nanjing Medical University from January 2013 to October 2021 were collected. There were 1 339 males and 977 females, aged (61±12)years. All patients underwent D 3 radical surgery for rectal cancer. Observation indicators: (1) No.253 lymph node metastasis in patients with middle and low rectal cancer; (2) analysis of influencing factors for No.253 lymph node metastasis in patients with middle and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD. Count data were expressed as absolute numbers and percentages, and comparison between groups was performed by the chi-square test. Logistic regression model was used for multivariate analysis. Results:(1) No.253 lymph node metastasis in patients with middle and low rectal cancer. There were 128 of 2 316 patients with positive No.253 lymph node and 2 188 cases with negative No.253 lymph node. The No.253 lymph node metastasis rate was 5.527%(128/2 316). There were 568 of 2 316 patients with the distance from distal margin of tumor to anal margin as 8?10 cm, 766 cases as ≥6 cm and<8 cm, 982 cases as <6 cm. Of the 568 patients with the distance from distal margin of tumor to anal margin as 8?10 cm, 57 cases had positive No.253 lymph node, including 3 cases(5.263%) of high differentiated tumor, 9 cases(15.789%) of moderate differentiated tumor, 45 cases(78.948%) of low differentiated tumor, respectively. There was 0 case of the above 57 patients with positive No.253 lymph node in TNM stage Ⅰ, 0 case in TNM stage Ⅱ, 20 cases(35.088%) in TNM stage Ⅲ, 37 cases(64.912%) in TNM stage Ⅳ, respectively. Of the 766 patients with the distance from distal margin of tumor to anal margin as ≥6 cm and <8 cm, 42 cases had positive No.253 lymph node, including 4 cases(9.524%) of high differentiated tumor, 11 cases(26.190%) of moderate differentiated tumor, 27 cases(64.286%) of low differentiated tumor, respectively. There was 0 case of the above 42 patients with positive No.253 lymph node in TNM stage Ⅰ, 0 case in TNM stage Ⅱ, 19 cases(45.238%) in TNM stage Ⅲ, 23 cases(54.762%) in TNM stage Ⅳ, respectively. Of the 982 patients with the distance from distal margin of tumor to anal margin as <6 cm, 29 cases had positive No.253 lymph node, including 1 case (3.448%) of high differentiated tumor, 3 cases (10.345%) of moderate differentiated tumor, 25 cases (86.207%) of low differentiated tumor, respectively. There was 0 case of the above 29 patients with positive No.253 lymph node in TNM stage Ⅰ, 0 case in TNM stage Ⅱ, 12 cases(41.379%) in TNM stage Ⅲ, 17 cases(58.621%) in TNM stage Ⅳ, respectively. (2) Analysis of influencing factors for No.253 lymph node metastasis in patients with middle and low rectal cancer. Results of univariate analysis showed that tumor T staging, tumor N staging, tumor TNM staging, tumor differentiation degree, the distance from distal margin of tumor to anal margin were related factors for No.253 lymph node metastasis in patients with middle and low rectal cancer ( χ2=28.48, 44.58, 172.62, 227.67, 34.57, P<0.05). Results of multivariate analysis showed that tumor T staging as stage T4, tumor N staging as stage N2, tumor TNM staging as stage Ⅳ, low differentiated tumor, the distance from distal margin of tumor to anal margin as ≥6 cm and <8 cm, 8?10 cm were independent risk factors for No.253 lymph node metastasis in patients with middle and low rectal cancer ( odds ratio=2.74, 3.48, 10.72, 21.47, 1.92, 3.67, 95% confidence intervals as 1.91?3.92, 2.42?4.98, 7.36?15.62, 10.33?44.60, 1.27?2.91, 2.31?5.81, P<0.05). Conclusions:The risk of No.253 lymph node metastasis is relatively high in middle and low rectal cancer patients with long distance from distal margin of tumor to anal margin, low differentiated tumor, and in high TNM stages. Tumor T staging as stage T4, tumor N staging as stage N2, tumor TNM staging as stage Ⅳ, low differentiated tumor, the distance from distal margin of tumor to anal margin as ≥6 cm and <8 cm, 8?10 cm are independent risk factors for No.253 lymph node metastasis in patients with middle and low rectal cancer.

Objective:To study the clinical features and drug resistance profile of neonatal sepsis caused by different species of Klebsiella.Methods:From January 2009 to December 2018, cryopreserved Klebsiella strains from blood culture of neonatal sepsis cases in NICU of our hospital were reactivated. Molecular identification and antimicrobial susceptibility tests were performed. Clinical features, laboratory tests, drug resistance profile and prognosis of these patients were analyzed retrospectively.Results:A total of 29 strains of Klebsiella were reactivated. Molecular identification assigned 22 cases (75.9%) into Klebsiella pneumoniae (Kpn) group and 7 cases (24.1%) into Klebsiella quasipneumoniae (Kqu) group. Gestational age and birth weight of Kpn group were higher than Kqu group [(33.1±3.2) weeks vs. (30.6±0.9) weeks, (1 847±677) g vs. (1 416±121) g] ( P<0.05). Abdominal distension was more common in Kqu group than Kpn group [42.9% (3/7) vs. 4.5% (1/22), P<0.05]. No significant differences existed in the laboratory tests including white blood cell count, platelet count, hypersensitive C-reactive protein and procalcitonin between the two groups ( P>0.05). Kpn was 100.0% sensitive to Cefazolin-Tazobactam and Amikacinto and less sensitive to Imipenem and Cefperazone-Sulbactam, Meropenem and Ertapenem. Kqu was generally more sensitive than Kpn and the sensitivity of Kqu to Imipenem was 100.0%. No significant differences existed of the prognosis between the two groups ( P>0.05). Conclusions:Kpn is the main pathogen of neonatal Klebsiella sepsis. Kqu sepsis is more common in neonates with smaller gestational age and lower birth weight. Abdominal distention is common presenting symptom in Kpn sepsis and sensitive antibiotics should be used early.

Objective: To investigate psychoactive substance abuse and associated factors among middle school students in Liaoning, and to provide policy suggestions and reference opinions for relevant departments. Methods: A questionnaire survey was conducted among 12 598 middle school students in 10 cities of Liaoning by multi stage stratified cluster sampling. Multivariate Logistic regression model was used to analyze associated factors of psychoactive substance abuse. Results: About 0.94% ( n =118) of all participants reported substance abuse behavior, the highest abuse rate was in the third grade students in vocational middle school, the most common psychoactive substance was “laughing balloon”, accounting for 0.57%. Multivariate Logistic regression analysis revealed that girls, moderate academic burden were generally negatively associated with more psychoactive substance use( OR = 0.57 , 0.58, P <0.05). Academic performance class was ranked in the last ten, monthly pocket money more than 500 yuan and sleep with medication were generally positively associated with more psychoactive substance use ( OR =1.93, 2.52, 4.29, P < 0.05 ). Conclusion The problem of psychoactive substance abuse among middle school students can not be ignored. Effective prevention and control of psychoactive substance abuse can be achieved through publicity, education, awareness raising, early intervention, counseling and treatment, and through coordination of adolescents, families, schools, government and the society.

Background Programmed necrosis is closely related to the occurrence and development of neurodegenerative diseases, but whether lead causes programmed cell necrosis has not been reported. Objective This experiment is designed to probe into the function of programmed necrosis and the effect of its inhibitor on lead-induced microglia (BV2 cell) injury. Methods The BV2 cells at logarithmic growth phase were treated with 0, 1, 5, 10, 25, 50, 100, and 200 μmol·L⁻¹ lead acetate for 12, 24, 36, and 48 h, respectively, and methylthiazolyldiphenyl-tetrazolium bromide (MTT) was used to determine cell viability. After treatment with 0, 25, 50, and 100 μmol·L⁻¹ lead acetate for 24 h, enzyme-linked immunosorbent assay, Western blotting, and flow cytometry were used to determine the expressions of tumor necrosis factor-α (TNF-α), receptor-interacting protein kinase 3 (RIPK3), receptor-interacting protein kinase 1 (RIPK1), and mixed lineage kinase domain-like protein (MLKL) in the cells, and the effect of RIPK1 inhibitor Nec-1 pretreatment on lead-induced BV2 cell injury . Results The BV2 cell viability decreased with higher lead concentration (r_{12 h}=−0.995, r_{24 h}=−0.984, r_{36 h}=−0.983, r_{48 h}=−0.981, all P<0.01) and time extension (only for 5 μmol·L⁻¹ lead acetate, r=−0.994, P<0.01). Compared with the control group, the BV2 cell viability decreased at the same exposure time when the concentration of lead was above 10 μmol·L⁻¹ (P<0.01). Compared with the control group, the expressions of RIPK1 and MLKL were increased in the 25, 50, and 100 μmol·L⁻¹ lead groups (P<0.05 or 0.01), accompanied by an increase in the contents of inflammatory cytokine TNF-α, especially in the 100 μmol·L⁻¹ lead group, the increment was the highest (P<0.01). The expression levels of p-RIPK1 and p-MLKL in BV2 cells were both increased when the concentration of lead acetate was above 50 μmol·L⁻¹ (P<0.01). In addition, pretreatment with Nec-1 increased the cell viability rate and decreased the necrosis and late apoptosis rate of BV2 cells exposed to lead compared with corresponding lead exposure groups (P<0.05). Conclusions Lead can reduce BV2 cell viability, increase necrosis rate, and up-regulate the expressions of RIPK1, RIPK3, amd MLKL, and the phosphorylation levels of RIPK1 and MLKL. The RIPK1 inhibitor Nec-1 has an intervention effect on lead-induced damage in BV2 cells, indicating that programmed necrosis may play a role in lead neurotoxicity.

Objective:To analyze the incidence and epidemiological characteristics of traumatic spinal cord injury in China in 2018.Methods:Multi-stage stratified cluster sampling was used to randomly select hospitals capable of treating patients with spinal cord injury from 3 regions，9 provinces and 27 cities in China to retrospectively investigate eligible patients with traumatic spinal cord injury admitted in 2018. National and regional incidence rates were calculated. The data of cause of injury，injury level，severity of injury，segment and type of fracture，complications，death and other data were collected by medical record questionnaire，and analyzed according to geographical region，age and gender.Results:Medical records of 4，134 patients were included in this study，with a male-to-female ratio of 2.99∶1. The incidence of traumatic spinal cord injury in China in 2018 was 50.484 / 1 million （95% CI 50.122-50.846）. The highest incidence in the Eastern region was 53.791 / 1 million （95% CI 53.217-54.365）. In the whole country，the main causes of injury were high falls （29.58%），as well as in the Western region （40.68%），while the main causes of injury in the Eastern and Central regions were traffic injuries （31.22%，30.10%）. The main injury level was cervical spinal cord in the whole country （64.49%），and the proportion of cervical spinal cord injury in the Central region was the highest （74.68%），and the proportion of lumbosacral spinal cord injury in the Western region was the highest （32.30%）. The highest proportion of degree of injury was incomplete quadriplegia （55.20%），and the distribution pattern was the same in each region. A total of 65.87% of the patients were complicated with fracture or dislocation，77.95% in the Western region and only 54.77% in the Central region. In the whole country，the head was the main combined injury （37.87%），as well as in the Eastern and Central regions，while the proportion of chest combined injury in the Western region was the highest （38.57%）. A total of 32.90% of the patients were complicated with respiratory complications. There were 23 patients （0.56%） died in hospital，of which 17（73.91%） died of respiratory dysfunction. Conclusions:The Eastern region of China has a high incidence of traumatic spinal cord injury. Other epidemiological features include high fall as the main cause of injury cervical spinal cord injury as the main injury level，incomplete quadriplegia as the main degree of injury，head as the main combined injury，and respiratory complications as the main complication.