[Research progress on the current situation of long working hours and its adverse health effects on occupational population].

In recent years, with the development of social economy, the extension of working hours has become a common phenomenon all over the world. Occupational health hazards caused by long working hours have attracted extensive attention. This paper summarized the research related to long working hours at home and abroad in recent years, described the current situation of long working hours, expounded the adverse effects of long working hours on mood or emotional symptoms, chronic diseases and its pathogenic mechanism of occupational population. We summarized the situation and limitations in this field, and to provide new ideas and directions for further in-depth research.

[Investigation and analysis of noise hazards in three key industries in Shenzhen City].

Objective: To understand the basic situation of noise hazards in wood furniture manufacturing, stone processing and special equipment manufacturing industries in Shenzhen City, and to provide basis for preventing and controlling noise hazards. Methods: In August 2019, stratified random sampling ws used to select 21 wood funiture manafacturing, 15 stone processing and 24 special equipment manufactruing as survey object. Through the methods of occupational health field investigation, noise intensity measurement and occupational health examination data collection, the noise hazards of 60 enterprises in three industries were statistically analyzed. Results: There were 154, 44 and 113 noise detection points in wood furniture manufacturing, stone processing and special equipment manufacturing enterprises, and 101, 27 and 78 out of standard points respectively, and the exceeding standard rates were 65.6% (101/154) , 61.4% (27/44) and 69.0% (78/113) , respectively. There were 1670, 172 and 856 workers exposed to noise in the three industries. Among them, 1198, 134 and 703 people had taken occupational health examination. The physical examination rates were 71.7% (1198/1670) , 77.9% (134/172) and 82.1% (703/856) , respectively. The abnormal rates were 19.1% (229/1198) , 51.5% (69/134) and 37.8% (266/703) , respectively. Conclusion: High intensity noise working environment, too long noise exposure time, incorrect wearing of personal protective equipment and neglect of occupational health examination are important reasons for hearing loss of noise exposed personnel.

[P(0) protein promotes the expression of INF-γ and IL-10 in peripheral blood of n-hexane neuropathy patients].

Objective: To study the changes of monocyte cytokines in peripheral blood of n-hexane neuropathy patients induced by P(0) protein, and to explore the role of autoimmunity in n-hexane neuropathy patients. Methods: In May 2018, 5 patients with peripheral neuropathy diagnosed as n-hexane poisoning were selected as case group in Shenzhen Prevention and Treatment Center for Occupational Disease in 2017. 6 workers exposure to n-hexane and 6 workers without n-hexane exposure were selected as contact group and control group. Peripheral blood mononuclear cells(PBMC) were isolated from venous blood. Results: The number of spots produced by INF-γ and IL-10 increased after stimulation with P(0) protein in case group, and the positive rate was significantly higher than control group and the contact group. Conclusion: Autoimmunity induced by P(0) protein may be involved in the occurrence of myelin sheath damage in n-hexane neuropathy patients.

Visual detection technique for efficient screening and isolation of Salmonella based on a novel enrichment assay using chromatography membrane.

To detect Salmonella more efficiently and isolate strains more easily, a novel and simple detection method that uses an enrichment assay and two chromogenic reactions on a chromatography membrane was developed. Grade 3 chromatography paper is used as functionalized solid phase support (SPS), which contains specially optimized medium. One reaction for screening is based on the sulfate-reducing capacity of Salmonella. Hydrogen sulfide (H2S) generated by Salmonella reacts with ammonium ferric citrate to produce black colored ferrous sulfide. Another reaction is based on Salmonella C8 esterase that is unique for Enterobacteriaceae except Serratia and interacts with 4-methylumbelliferyl caprylate (MUCAP) to produce fluorescent umbelliferone, which is visible under ultraviolet light. A very low detection limit (10(1) CFU ml(-1)) for Salmonella was achieved on the background of 10(5) CFU ml(-1) Escherichia coli. More importantly, testing with more than 1,000 anal samples indicated that our method has a high positive detection rate and is relatively low cost, compared with the traditional culture-based method. It took only 1 day for the preliminary screening and 2 days to efficiently isolate the Salmonella cells, indicating that the new assay is specific, rapid, and simple for Salmonella detection. In contrast to the traditional culture-based method, this method can be easily used to screen and isolate targeted strains with the naked eye. The results of quantitative and comparative experiments showed that the visual detection technique is an efficient alternative method for the screening of Salmonella spp. in many applications of large-sized samples related to public health surveillance.