Klebsiella pneumoniae(K.pneumoniae)is important zoonotic pathogen causing multiple local and systemic infections.At present,the drug resistance of K.pneumoniae is serious,and mul-tiple drug-resistant strains continue to emerge.Even the incidence of drug-resistant K.pneumoniae infection is increasing year by year.In this study,K.pneumoniae clinical isolate 71Y was used as the starting strain,and a phage with strong lytic activity was successfully obtained from sewage samples.The phage was named vB_KpnP_71Y(abbreviated as P71Y),the general biological char-acteristics and genome of P71Y were further studied and analyzed.P71Y can form clear plaque with a diameter of 2-5 mm and a translucent halo ring on the host bacterium 71Y lawn.Electron micros-copy observation shows that P71Y is a member of the order Autographiviridae and family Caudovi-rales.The incubation period for P71Y infected with K.pneumoniae is about 3 minutes,and one in-fection cycle lasts for about 50 minutes.Each infection of a bacterium can produce approximately 58 progeny phage virus particles.Cleavage spectra showed that the phage could lysate K20 and K57 serotypes of K.pneumoniae.The phage had good stability at 4-50 ℃ and pH values of 3-12.Genom-ic analysis revealed that P71Y contained a double-stranded DNA with a total length of 39 700 bp and a G+C content of 53％.There are a total of 53 coding genes,P71Y does not carry virulence factors and drug resistance genes,which has shown genetic safety.This study isolated a novel lytic phage that can cleave multiple serotypes of K.pneumoniae,which provided experimental materials for the study of the interaction between bacteriophages,different serotypes of K.pneumoniae,and the application of phage for the prevention and controlling of infections caused by multi-drug-re-sistant K.pneumoniae.

The complement system is an important part of the innate immune system,including more than 50 secretory proteins and membrane-bound proteins,and it contributes to the clearance of apoptotic cells and invading pathogens to limit inflammatory immune responses and maintaining brain homeostasis.Complement activity is strictly regulated to protect cells from random attacks or to prevent the deposition of complement proteins in physiological cases.However,overactivation or abnormal regulation of the complement cascade in the brain can lead to neuronal damage and brain dysfunction.Recent studies have pointed out that changes in complement molecules exist in patients with psychiatric diseases and play an important role in the occurrence and development of diseases by regulating the function of neurons and glial cells.Therefore,summarizing the latest research progress of complement system in psychiatric diseases such as schizophrenia,autism spectrum disorder,major depression,bipolar disorder and anxiety disorder can provide new ideas for preventing and controlling psychiatric diseases caused by abnormal activation of complement system.

Inflammatory injury of the intestine is often accompanied by symptoms such as damage to intestinal mucosa, increased intestinal permeability, and intestinal motility dysfunction. Inflammatory factors spread throughout the body via blood circulation, and can cause multi-organ failure. Pyroptosis is a newly discovered way of programmed cell death, which is mainly characterized by the formation of plasma membrane vesicles, cell swelling until the rupture of the cell membrane, and the release of cell contents, thereby activating a drastic inflammatory response and expanding the inflammatory response cascade. Pyroptosis is widely involved in the occurrence of diseases, and the underlying mechanisms for inflammation are still a hot spot of current research. The caspase-1 mediated canonical inflammasome pathway of pyroptosis and caspase-4/5/8/11-mediated non-canonical inflammasome pathway are closely related to the occurrence and development of intestinal inflammation. Therefore, investigation of the signaling pathways and molecular mechanisms of pyroptosis in intestinal injury in sepsis, inflammatory bowel diseases, infectious enteristic, and intestinal tumor is of great significance for the prevention and treatment of intestinal inflammatory injury.
Humans ; Pyroptosis ; Inflammasomes/metabolism* ; Apoptosis ; Caspase 1 ; Inflammation

Objective:To investigate the survival of 2019 novel coronavirus (2019-nCoV) on the surface of inanimate objects at different temperatures.Methods:CNKI, WanFang Database, VIP, PubMed, Web of Science, Cochrane Library and Embase were searched for articles published from January 1, 2020 to June 15, 2022 with "2019-nCoV, surface, inanimate, environments, environmental, matrices, factors, conditions, contact, personal protective equipment, transmission, stability, persistence, viability, survival, survivability, infectivity, transmission". The literature was screened according to the inclusion and exclusion criteria. After the data in the literature were extracted, the improved MINORS scale was used to evaluate the literature quality. RevMan5.4 software was used for meta analysis, and Stata17.0 software was used for Begg′s test and Egger′s test to evaluate the publication bias.Results:A total of 20 studies were included. Meta-analysis result showed that the survival ability of 2019-nCoV on the surface of non-porous objects (stainless steel, glass and plastic) was significantly different from that on the surface of porous objects (cloth, wood board, banknote, cotton, cardboard) ( Z=5.94, P<0.001; Z=17.85, P=0.004; Z=38.20, P<0.001). The result of subgroup analysis showed that there was no significant difference in the survival ability of the virus between banknotes and glass, plastic surfaces under the same conditions ( Z=0.81, P=0.420; Z=1.79, P=0.070). The half-life of the virus at 4 ℃ was significantly different from that at 25 ℃[ MD=47.49 h, 95% CI: 7.00~87.99, Z=2.30, P=0.020]; The half-life of the virus at 25 ℃ was also significantly different compared with that at 35 ℃[ MD=5.46 h, 95% CI: 0.13~10.78, Z=2.01, P=0.040]. Conclusions:Under the same conditions, the survival time of 2019-nCoV on the surface of nonporous objects was longer than that on the surface of porous objects, and the higher the temperature, the shorter the survival time.

Objective:To explore the effect of social isolation (SI) on cognitive function and the phenotypic transition of hippocampal astrocytes in mice.Methods:Twenty male C57BL/6 mice aged 3-4 weeks were randomly divided into normal group house (GH group) and social isolation group (SI Group). The mice in SI group were fed one per cage for 8 weeks to establish a social isolation model, and the mice in GH group were fed five per cage. The cognitive function of mice was detected by the novel object recognition test and novel location recognition test. The expression of astrocyte marker glial fibrillary acidic protein (GFAP) was detected by immunohistochemistry, RT-PCR and Western blot.The astrocyte morphology change was quantitatively analyzed by Sholl Analysis.The expression of the hippocampal A1-A2 astrocytes markers proteasome subunit beta 8(PSMB8) and a member of the S100 family of Ca 2+ -binding proteins (S100A10) were determined by RT-PCR and Western blot. Statistical analysis was performed using GraphPad Prism 6.0 software, and t-test was used for comparison between two groups. Results:The results of cognitive function showed that the exploration index of novel object ((-5.54±3.30)%, (33.42±7.14)%; t=4.680, P=0.001) and the exploration index of novel location((-7.96±4.81)%, (23.55±8.20)%; t=3.670, P=0.008) in SI group were both lower than those in GH group.Immunohistochemical results showed that the number of GFAP positive cells in hippocampus of SI group was significantly lower than that of GH group((369.90±42.97), (544.90±57.64); t=2.480, P=0.023). The results of Sholl analysis showed that the protuberance of hippocampal astrocytes in SI Group retracted.There were significant differences in the number of intersections between the two groups at 6, 8, 10, 12, 14 and 16 μm away from astrocyte cell body(all P<0.05). Western blot showed that the expression of GFAP protein in SI group was lower than that in GH group((0.85±0.05), (1.03±0.06); t=2.527, P=0.028). The results of PCR showed that the expression of GFAP mRNA in SI group was lower than that in GH group ((0.83±0.05), (1.00±0.03); t=2.970, P=0.018). The expression of A1 phenotypic marker PSMB8 mRNA ((1.58±0.17), (1.00±0.06); t=2.931, P=0.011) and A2 phenotypic marker S100A10 mRNA ((1.52±0.14), (1.00±0.07); t=3.121, P=0.007) in the hippocampus of SI group were higher than those in GH group.Compared with the GH group, the expression of the neurotrophic factors IGF-1 mRNA in the SI group was down-regulated ((0.73±0.07), (1.00±0.08); t=2.327, P<0.05), while the expression of LCN2 mRNA((1.12±0.03), (1.00±0.03), t=2.575, P<0.05), IL-1β mRNA(1.76±0.19), (1.00±0.07), t=3.460, P<0.01) and TNF-α mRNA((2.18±0.42), (1.00±0.07), t=2.427, P<0.05) were up-regulated in the SI group. Conclusion:The pathological mechanism of social isolation-induced cognitive impairment in mice may be related with the phenotypic changes of astrocytes.

Objective:To investigate the current situation of students' academic procrastination behavior in medical colleges and universities and its influencing factors, and to put forward suggestions to reduce the academic procrastination of medical students.Methods:A total of 1 327 undergraduate students from three medical colleges and universities in Heilongjiang Province were randomly selected to receive questionnaire investigation on life satisfaction, anxiety, and academic procrastination. SPSS 23.0 was used for data analysis.Results:①The total procrastination scores of medical students were (35.00±8.92) points. ②There were statistical differences in the academic procrastination of medical students with different genders, whether the only children, the reasons for choosing the major, and the level of achievement ( P < 0.05). There was no statistical difference in academic procrastination among medical students of different ages and grades ( P > 0.05). ③Medical students' procrastination was positively correlated with their anxiety level ( r = 0.102, P < 0.01), and negatively correlated with life satisfaction ( r = -0.117, P < 0.01). ④Regression analysis showed that the following six predictive variables including the level of achievement, gender, life satisfaction, anxiety, reasons for choosing the major, and whether the only children could effectively explain the variance of 14.2% academic procrastination of medical students. Conclusion:The overall degree of academic procrastination of medical students is higher than that of non-medical students. And the students' achievement level, gender, life satisfaction, anxiety, the reasons for choosing this major and whether the only child are the influencing factors of academic procrastination.

Objective:To investigate whether irradiated U251 glioma cells can induce bystander effects in unexposed neural stem cells (NSCs) thus affecting its proliferation, stemness and differentiation.Methods:The cells were divided into NSCs group, NSCs+ U251 group (co-cultured with U251) and NSCs+ IR U251 group (co-cultured with 10 Gy irradiated U251). Glioma cells and NSCs were co-cultured in a transwell insert set. Cell counting and neurosphere diameter measuring were carried out to evaluate the proliferation and neurosphere formation ability of NSCs. Immunofluorescence assay was performed to detect the expression of Nestin protein to evaluate the stemness maintenance of NSCs, and to measure the expression levels of Tuj1 and GFAP proteins, the number of neuronal dendrites, synaptic length, the number of glial protrusions, as well as the length of glial protrusions.Results:The number of NSCs cultured with irradiated U251 cells was obviously smaller than that of NSCs cultured with sham-irradiated U251 cells ( t=2.52, P<0.05). The neurosphere formation ability of NSCs and the percentage of Nestin positive NSCs after co-culture with irradiated U251 cells significantly reduced in comparison with those after co-culture with sham-irradiated U251 cells ( t=-3.50, P<0.05). The percentages and the extent of NSCs differentiating into neuronal cells and glial cells( t=6.09, P<0.05)decreased obviously after co-culture with irradiated U251 cells in comparison with those after co-culture with sham-irradiated U251 cells. Conclusions:Irradiated glioma cells can significantly inhibit the proliferation, stemness and differentiation of unexposed NSCs due to bystander effect.

Objective:To investigate the effect of MCC950 (a NLRP3 inflammasome inhibitor) on cognitive impairment in mice with radiation-induced inflammatory brain injury.Methods:Mice were divided into normal (NS) group, whole body irradiation (IR) group and MCC950 intervention post irradiation (IR+ MCC950) group according to the random number table method, with 15 mice in each group. The mice in IR group and IR+ MCC950 group were irradiated with a single dose of 4.0 Gy. The radiation source was 137Cs and the dose rate was 1.118 Gy/min. The mice in NS group were not irradiated. Mice in IR+ MCC950 group were injected intraperitoneally with MCC950 once a day (10 mg/kg each time) from 3 weeks after irradiation. Behavioral tests such as new and old things recognition experiment and social cognition experiment were used to detect the cognitive function of mice. Immunohistochemistry was used to detect the expression of NeuN protein in CA3 area of mouse hippocampus. PCR and Western blot were used to detect the expression of NLRP3 inflammatory body related protein. Results:Compared with NS group, the short-term and long-term recognition index of new and old things in the IR group decreased significantly ( t=4.321, 5.473, P<0.01), and the social cognitive recognition index of the IR group also decreased significantly ( t=2.097, P<0.05). MCC950 treatment reversed the above changes (short-term and long-term new and old thing recognition test: t=5.860, 4.598, P<0.05; new and old position recognition test: t=3.040, P<0.05; social cognition test: t=4.021, P<0.01). The expression of NLRP3, Caspase-1, IL-1 β and IL-18 in mice hippocampus of the IR group was significantly higher than that of the control group ( t=2.699, 8.515, 3.340, 3.950, P<0.05). Compared with NS mice, radiation significantly increased the expressions of Bax, Caspase-3 and PARP1 in hippocampus ( t=3.887, 2.742, 3.287, P<0.05), while MCC950 significantly decreased the expressions of Bax, Caspase-3 and PARP1( t=2.852, 4.090, 9.614, P<0.05). Conclusions:NLRP3 inflammasome inhibitor MCC950 could alleviate radiation-induced cognitive impairment, which may be due to the inhibition of hippocampal inflammatory and neuronal death.

PURPOSE: Rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone administered every 3 weeks (R-CHOP-21) is the standard care for diffuse large B-cell lymphoma (DLBCL). It is unknown whether the dose-dense R-CHOP (R-CHOP-14) could improve the outcome of the disease in Asian population. MATERIALS AND METHODS: Newly diagnosed DLBCL patients were centrally, randomly assigned (1:1) to receive R-CHOP-14 or R-CHOP-21. R-CHOP-14 was administered every 2 weeks, and R-CHOP-21 was administered every 3 weeks. Primary end point was disease-free survival (DFS). Secondary end points included overall survival (OS), progression-free survival (PFS), response rate and toxicities. RESULTS: Seven hundred and two patients were randomly assigned to receive R-CHOP-14 (n=349) or R-CHOP-21 (n=353). With a median follow-up of 45.6 months, the two groups did not differ significantly in 3-year DFS (79.6% for R-CHOP-14 vs. 83.2% for R-CHOP-21, p=0.311), 3-year OS (77.5% for R-CHOP-14 vs. 77.6% for R-CHOP-21, p=0.903), or 3-year PFS (63.2% for R-CHOP-14 vs. 66.1% for R-CHOP-21, p=0.447). Patients with an International Prognostic Index (IPI) score ≥ 2 had a poorer prognosis compared to those with an IPI score < 2. Grade 3/4 hematologic and non-hematologic toxicities were manageable and similar between R-CHOP-14 and R-CHOP-21. CONCLUSION: R-CHOP-14 did not improve the outcome of DLBCL compared to R-CHOP-21 in Asian population. With manageable and similar toxicities, both of the two regimens were suitable for Asian DLBCL patients. For high-risk patients with IPI ≥ 2, new combination regimens based on R-CHOP deserve further investigation to improve efficacy.
Asian Continental Ancestry Group ; B-Lymphocytes ; Cyclophosphamide ; Disease-Free Survival ; Doxorubicin ; Follow-Up Studies ; Humans ; Lymphoma, B-Cell ; Prednisone ; Prognosis ; Rituximab ; Vincristine

Objective To examine the current situation of the career plateau among anesthesiologists and analyze the impact of occupational stressors on it. Methods A questionnaire survey was conducted on the anesthesiologists. A total of 300 questionnaires were distributed and 278 questionnaires were effectively collected. Statistical analysis using SPSS 19.0 was performed to assess the status quo of career plateau among anesthesiologists. Pearson correlation analysis and stepwise regression analysis were used to analyze the influence of occupational stressors on career plateau . Results The average value of occupational stressors among anesthesiologists was (3.22±0.55), and the average value of career plateau was (3.90±0.70). Occupational interest in the occupational stressors of anesthesiologists is negatively correlated with the occupational plateau (r=-0.552, P<0.01), and career development is negatively correlated with occupational plateau (r=-0.541, P<0.01) as well. Both occupational interest and career development show a negative predictive effect on the career plateau (β=-0.359, P<0.01 andβ=-0.334, P<0.01, respectively). Conclusion Career plateau among anesthesiologists is at a medium-to-high level. Occupational interest and occupational development in occupational stressors have a negative predictive effect on occupational plateaus, so hospital managers should pay attention to them.