Objective:To discuss the promotive effect of nerve growth factor(NGF),which is highly expressed in the adipose-derived stem cell(ADSC)-induced Schwann-like cells(SCLCs),on the growth of dorsal root ganglion(DRG)cell processes in the rats,and to clarify its mechanism.Methods:The ADSCs were extracted from the epididymal adipose tissue of the SD rats,and their multidirectional differentiation potential was identified through osteogenic,adipogenic,and chondrogenic induction.The ADSCs were induced to differentiate into the SCLCs,and the expression levels of glial fibrillary acidic protein(GFAP)and S100 calcium-binding protein β(S100β)protein in the ADSCs and SCLCs were detected by immunofluorescence staining and Western blotting methods.The DRG cells were isolated and cultured,and immunofluorescence staining was used to detect the βⅢ-tubulin expression in the DRG cells for identification.The SCLCs were co-cultured with the DRG cells(co-culture group),the single-culture DRG cells were regared as DRG group and toluidine blue staining was used to observe and measure the length of DRG cell processes under the optical microscope in co-culture group and DRG group.Small interfering RNA(siRNA)transfection was used to knock down NGF,and plasmid transfection was used to over-express NGF.Real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the NGF mRNA expression levels in the cells in various groups;enzyme-linked immunosorbent assay(ELISA)method was used to detect the NGF protein levels in the cell supernatants.The transfected SCLCs were co-cultured with DRG cells and divided into control group,siNC/vector group,NGF knockdown group(si-NGF group),and NGF over-expression group(oe-NGF group).The lengths of DRG cell processes in various groups were observed.Results:The primary ADSCs adhered within 24 h after seeding,with a small number of lipid droplets remaining.After 3 d of culture,the cells were mostly short spindle-shaped,fusiform,or polygonal,growing rapidly in a vortex pattern.After passaging,the cells exhibited a uniform morphology,appearing as long spindles arranged in a fish-school pattern.After 14 d of adipogenic induction,the cell morphology changed from spindle-shaped to flat-round,with translucent lipid droplets forming in the cytoplasm,which were stained red by Oil Red O.After 28 d of osteogenic induction,the cells appeared sand-like with blurred morphology,and calcified nodules were observed,which were stained red by Alizarin Red and deposited in the extracellular matrix.After 28 d of chondrogenic induction in a 3D culture system,millet-sized chondrogenic spheres formed.Frozen sections of the spheres were stained with Alcian Blue,and acidic mucopolysaccharides in the cartilage tissue were stained blue under the microscope.Under the fluorescence microscope,the third-passage purified ADSCs showed positive expression of CD29[fluorescein isothiocy anate(FITC)-labeled green fluorescence]and CD44(Cy3-labeled red fluorescence).The immunofluorescence staining results showed that GFAP was labeled with FITC(green fluorescence),and S100β was labeled with Cy3(red fluorescence).The Western blotting results showed that compared with ADSCs,the expression levels of S100β and GFAP proteins in the SCLCs were increased(P<0.05).The primary DRG cells began to adhere 6 h after conventional culture,and after 3 d,the cell bodies appeared round and bright,with two linear processes extending from them.Under fluorescence microscope,the cells positively expressed the neuron-specific marker βⅢ-tubulin,confirming that the isolated cells were DRG cells.Compared with the ADSCs,the NGF protein expression level in the SCLCs was increased(P<0.05).Compared with DRG group,the length of DRG cell processes in co-culture group was the highest when DRG cells and SCLCs were co-cultured at a 1∶2 ratio(P<0.05).The RT-qPCR results showed that compared with si-NC group,the expression levels of NGF mRNA in the cell supernatant in si-NGF-1,si-NGF-2,and si-NGF-3 groups were significantly decreased(P<0.05),with si-NGF-1 showing the highest knockdown efficiency,which was selected for subsequent experiments.The ELISA results showed that compared with si-NC group,the NGF levels in the cell supernatant of si-NGF-1,si-NGF-2,and si-NGF-3 groups were decreased(P<0.05).Compared with Vector group,the expression level of NGF mRNA and NGF protein level in the supernatant in oe-NGF group were increased(P<0.05).Compared with control group and siNC/vector group,the length of DRG cell processes in si-NGF group was decreased(P<0.05),while the length of DRG cell processes in oe-NGF group was increased(P<0.05).Conclusion:ADSCs can be directionally differentiated into SCLCs,and the differentiated cells highly express NGF.Knockdown or overexpression of NGF can affect the growth of DRG cell processes.

OBJECTIVE To explore the isolation rates,drug resistance and molecular epidemiological characteristics of carbapenem-resistant gram-negative bacilli(CRGNB)isolated from intensive care units(ICU)of a tertiary hos-pital so as to provide bases for prevention and control of the nosocomial infections caused by CRGNB.METHODS The environmental surfaces that were high frequently contacted by the patients with CRGNB infections[carbapen-em-resistant Klebsiella pneumoniae(CRKP),carbapenem-resistant Acinetobacter baumannii(CRAB),carbap-enem-resistant Pseudomonas aeruginosa(CRPA)]and their hands were randomly sampled from the ICU of a ter-tiary three-A hospital from Apr.2024 to Aug.2024.Multilocus sequence typing(MLST)and detection of drug re-sistance genes were performed by means of complete genome sequencing technique and bioinformatics,and the ho-mology between the CRGNB strains isolated from the patients and the strains isolated from their surrounding was observed.RESULTS Totally 30(7.85％)strains of CRGNB were isolated,23(6.02％)of which were CRKP,7(1.83％)were CRAB,and no strain of CRPA was detected.The molecular subtyping showed that ST 11(93.33％)was dominant among the CRKP strains,and ST2(69.23％)was dominant among the CRAB strains.The phylogenetic analysis indicated that there were clonal transmission tendencies of CRKP-ST11 and CRAB-ST2.The analysis of drug resistance genes showed that the CRAB strains mainly carried ant(3")-lla(100％),blaOXA-23(92.31％)and amvA(92.31％);blaOXA-23 and blaOXA-66 were the major carbapenems resistance genes;the CRKP strains mainly carried the drug resistance genes emrDh,rmtB1,fosA and kdeA(all were 96.67％),followed by the carbapenems resistance gene blaKPC-2(90.00％).CONCLUSIONS ST11 is the predomi-nant molecular subtype for CRGNB among the CRKP strains isolated from the ICU,anf ST2 predominant among the CRAB strains;the carrying rates of drug resistance genes are high.There is risk of clonal transmission.It is necessary to strengthen the monitoring and take comprehensive infection control measures so as to reduce the incidence of nosocomial infections.

OBJECTIVE To explore the isolation rates,drug resistance and molecular epidemiological characteristics of carbapenem-resistant gram-negative bacilli(CRGNB)isolated from intensive care units(ICU)of a tertiary hos-pital so as to provide bases for prevention and control of the nosocomial infections caused by CRGNB.METHODS The environmental surfaces that were high frequently contacted by the patients with CRGNB infections[carbapen-em-resistant Klebsiella pneumoniae(CRKP),carbapenem-resistant Acinetobacter baumannii(CRAB),carbap-enem-resistant Pseudomonas aeruginosa(CRPA)]and their hands were randomly sampled from the ICU of a ter-tiary three-A hospital from Apr.2024 to Aug.2024.Multilocus sequence typing(MLST)and detection of drug re-sistance genes were performed by means of complete genome sequencing technique and bioinformatics,and the ho-mology between the CRGNB strains isolated from the patients and the strains isolated from their surrounding was observed.RESULTS Totally 30(7.85％)strains of CRGNB were isolated,23(6.02％)of which were CRKP,7(1.83％)were CRAB,and no strain of CRPA was detected.The molecular subtyping showed that ST 11(93.33％)was dominant among the CRKP strains,and ST2(69.23％)was dominant among the CRAB strains.The phylogenetic analysis indicated that there were clonal transmission tendencies of CRKP-ST11 and CRAB-ST2.The analysis of drug resistance genes showed that the CRAB strains mainly carried ant(3")-lla(100％),blaOXA-23(92.31％)and amvA(92.31％);blaOXA-23 and blaOXA-66 were the major carbapenems resistance genes;the CRKP strains mainly carried the drug resistance genes emrDh,rmtB1,fosA and kdeA(all were 96.67％),followed by the carbapenems resistance gene blaKPC-2(90.00％).CONCLUSIONS ST11 is the predomi-nant molecular subtype for CRGNB among the CRKP strains isolated from the ICU,anf ST2 predominant among the CRAB strains;the carrying rates of drug resistance genes are high.There is risk of clonal transmission.It is necessary to strengthen the monitoring and take comprehensive infection control measures so as to reduce the incidence of nosocomial infections.

Using high-energy proton to image the region of interest can directly obtain the accurate estimation of the proton stopping power of the lesions,which is of great significance to reduce the range uncertainty in proton therapy.As a fundamental function of proton computed tomography(CT),radiographic imaging plays a crucial role in assisting clinical positioning.The study develops a compact proton CT detector based on an active array pixel CMOS chip in Monte-Carlo simulation toolkit Geant4,and evaluates the radiographic imaging capability of the system using 180 MeV protons.The angles of tracks are successfully reconstructed.CTP404,CTP528,and the CTP515 of specific materials are used for simulation,obtaining the spatial and density resolutions,and measuring the proton relative stopping power(RSP).The image signal-to-noise ratio is improved when using 2° proton scattering angle cut-off value.The spatial resolution is 3-4 lp/cm measured using CTP528 module.The density resolution is better than 0.05 g/cm3,and the RSP resolution is within 5%when CTP404 module is used.Through the imaging of CTP515 phantom of specific material,it is demonstrated that the system has potential for imaging common human tissues.

Background Steel workers are exposed to occupational hazardous factors such as dust, noise, and heat, and often work in shifts, making them prone to sleep disorders. Objective To explore potential influencing factors of sleep disorders among workers in a steel enterprise in Gansu Province, and provide a basis for reducing the risk of sleep disorders among them. Methods From January to March 2022, a self-made questionnaire combined with the Pittsburgh Sleep Quality Index (PSQI) were used to investigate the employees of a steel enterprise in Gansu Province. According to their PSQI scores, they were divided into a normal sleep group and a sleep disorder group. The general demographic variables of the two groups were balanced by 1∶1 propensity score matching (PSM). Multiple logistic regression was used to analyze the contributing factors of sleep disorders. Restricted cubic spline (RCS) model was used to analyze potential dose-response relationship between weekly working hours and sleep disorders. Results The prevalence of sleep disorders in the steel workers was 48.06% (6029/12544). After PSM, 5847 pairs were successfully matched, and the distributions of matched variables were well balanced between the two groups. The results of multiple logistic regression showed that hypertension (OR=1.39, 95%CI: 1.24, 1.56), diabetes mellitus (OR=1.34, 95%CI: 1.07, 1.66), three-shift system (OR=1.26, 95%CI: 1.12, 1.41), dust exposure (OR=1.14, 95%CI: 1.01, 1.29), noise exposure (OR=1.23, 95%CI: 1.09, 1.39), heat exposure (OR=1.16, 95%CI: 1.04, 1.29), and work injury (OR=1.22, 95%CI: 1.02, 1.46) increased the risk of sleep disorders. Compared with workers with < 10 years of service, those with 10-20 years (OR=1.31, 95%CI: 1.19, 1.44), 20-30 years (OR=1.34, 95%CI: 1.19, 1.52), and ≥30 years of service (OR=1.35, 95%CI: 1.19, 1.53) had a higher risk of sleep disorders. Compared with non-exercise workers, the risk of developing sleep disorders was lower in workers with occasional exercise (OR=0.61, 95%CI: 0.56, 0.66) and regular exercise (OR=0.55, 95%CI: 0.49, 0.62). The RCS model showed that the weekly working hours and sleep disorders in the steel workers showed a nonlinear dose-response relationship (P<0.05 for overall trend, P<0.05 for nonlinear test). The relationship between weekly working hours and sleep disorders showed a "U" shaped distribution, with a significant increase in the risk of sleep disorders when the weekly working hours exceeded 49 h. Conclusion The non-occupational influencing factors of sleep disorders of employees in the steel enterprise include hypertension, diabetes, physical exercise, and occupational influencing factors include length of service, weekly working hours, shifts, dust exposure, noise exposure, heat exposure, and work injuries. It is recommended to consider both occupational and non-occupational factors to formulate appropriate sleep disorder prevention and control measures for steel employees to reduce the risk of sleep disorders.

{L-End}Objective To analyze the correlation between occupational burnout and sleep quality among steelworkers. {L-End}Methods A total of 11 491 steelworkers from a large steel enterprise in Gansu Province were selected as the research subjects using convenient sampling method. The Burnout Questionnaire and the Pittsburgh Sleep Quality Index Scale were used to investigate their occupational burnout and sleep quality. Hierarchical regression analysis was used to analyze the effects of occupational burnout on the sleep quality. {L-End}Results The detection rate of occupational burnout and sleep disorder were 50.4% and 39.0%, respectively. There was a positive correlation between the level of occupational burnout and the total score of sleep quality (Spearman correlation coefficient=0.454, P<0.05). The results of hierarchical regression analysis, adjusting for confounding factors such as gender, age, marital status, education level, alcohol consumption, exercise, weekly working hours, seniority, work shift, noise exposure, dust exposure, and high-temperature work, showed that the score of occupational burnout was positively related to the score of sleep quality(P<0.01), explaining 16.0% of the variance in the score of sleep quality among these steelworkers. {L-End}Conclusion The detection rate of occupational burnout and sleep disorders are relatively high among the steelworkers in this enterprise. Higher levels of occupational burnout are associated with poorer sleep quality. Alleviating occupational burnout among steelworkers may contribute to improving their sleep quality.

Objective:To explore the different metabolites in the follicular fluids (FFs) of polycystic ovary syndrome (PCOS) patients and non-PCOS patients and their effects on the maturation of mouse oocytes and the developmental potential of in vitro fertilization (IVF) embryos. Methods:The clinical data were collected for the retrospective cohort study. Animal experiments were conducted in a randomized controlled trial. This study included PCOS ( n=71) and non-PCOS ( n=70) patients who underwent the first IVF or intracytoplasmic sperm injection (ICSI) cycle in Shanghai JIAI Genetics & IVF institute from June 2019 to June 2020. The patients' FFs were collected and the clinical data from these patients were analyzed. Raman spectroscopy analysis technology was used to detect differences in the metabolic spectra of FFs between the two groups. Mouse GV phase oocytes were placed in FFs from PCOS patients and non-PCOS patients for in vitro maturation (IVM) culture respectively, then the matured mouse oocytes were collected for IVF. The effects of differential metabolites in FFs on mouse oocyte maturation and embryonic development were further explored. The Raman spectrum was also applied to identify the differences of the IVM spent culture media. Results:The MⅡ rate [82.19% (886/1 078)] and day 3 available embryo rate [51.30% (553/1 078)] from PCOS group were significantly lower than those of the non-PCOS group [85.85% (625/728), P=0.038; 53.30% (388/728), P=0.042]. However, there were no significant differences between the two groups in the cumulative clinical pregnancy rate and the cumulative live birth rate (all P>0.05). Raman was capable of distinguishing PCOS from non-PCOS FFs. The characteristic Raman displacement difference between the two groups is mainly concentrated in the 600-1 000 cm -1, as well as 1 168 cm -1, 1 344 cm -1, 1 440 cm -1, 1 504 cm -1, 1 632 cm -1 and 1 664 cm -1. The Raman characteristic shift database showed that the different metabolites of the two sets of FFs samples were mainly concentrated in protein, lipids, free nucleic acis, glucose, cholesterol, carotenoids, and amino acids. Mouse oocyte IVM results showed that the PCOS-FF group had a lower MⅡ rate [49.04% (77/157)] than that of non-PCOS group [65.07% (95/146), P=0.005). IVF results showed the PCOS-FF group had a significantly lower cleavage rate [46.75% (36/77)] than that of non-PCOS group [63.16% (60/95), P=0.031], but there was no significant difference in the blastocyst rate between the two groups ( P>0.05). Conclusion:Differential metabolites detected by Raman spectrum in the PCOS FFs may cause defected maturation of the oocytes, leading to infertility, and Raman spectroscopy is an effective approach towards PCOS diagnosis and the identification of metabolomics differences.

Objective:To explore the different metabolites in the follicular fluids (FFs) of polycystic ovary syndrome (PCOS) patients and non-PCOS patients and their effects on the maturation of mouse oocytes and the developmental potential of in vitro fertilization (IVF) embryos. Methods:The clinical data were collected for the retrospective cohort study. Animal experiments were conducted in a randomized controlled trial. This study included PCOS ( n=71) and non-PCOS ( n=70) patients who underwent the first IVF or intracytoplasmic sperm injection (ICSI) cycle in Shanghai JIAI Genetics & IVF institute from June 2019 to June 2020. The patients' FFs were collected and the clinical data from these patients were analyzed. Raman spectroscopy analysis technology was used to detect differences in the metabolic spectra of FFs between the two groups. Mouse GV phase oocytes were placed in FFs from PCOS patients and non-PCOS patients for in vitro maturation (IVM) culture respectively, then the matured mouse oocytes were collected for IVF. The effects of differential metabolites in FFs on mouse oocyte maturation and embryonic development were further explored. The Raman spectrum was also applied to identify the differences of the IVM spent culture media. Results:The MⅡ rate [82.19% (886/1 078)] and day 3 available embryo rate [51.30% (553/1 078)] from PCOS group were significantly lower than those of the non-PCOS group [85.85% (625/728), P=0.038; 53.30% (388/728), P=0.042]. However, there were no significant differences between the two groups in the cumulative clinical pregnancy rate and the cumulative live birth rate (all P>0.05). Raman was capable of distinguishing PCOS from non-PCOS FFs. The characteristic Raman displacement difference between the two groups is mainly concentrated in the 600-1 000 cm -1, as well as 1 168 cm -1, 1 344 cm -1, 1 440 cm -1, 1 504 cm -1, 1 632 cm -1 and 1 664 cm -1. The Raman characteristic shift database showed that the different metabolites of the two sets of FFs samples were mainly concentrated in protein, lipids, free nucleic acis, glucose, cholesterol, carotenoids, and amino acids. Mouse oocyte IVM results showed that the PCOS-FF group had a lower MⅡ rate [49.04% (77/157)] than that of non-PCOS group [65.07% (95/146), P=0.005). IVF results showed the PCOS-FF group had a significantly lower cleavage rate [46.75% (36/77)] than that of non-PCOS group [63.16% (60/95), P=0.031], but there was no significant difference in the blastocyst rate between the two groups ( P>0.05). Conclusion:Differential metabolites detected by Raman spectrum in the PCOS FFs may cause defected maturation of the oocytes, leading to infertility, and Raman spectroscopy is an effective approach towards PCOS diagnosis and the identification of metabolomics differences.

Objective:To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods:A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results:The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates.Conclusion:Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

Objective:To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods:A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results:The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates.Conclusion:Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.