Abstract: Objective - - To establish a pre column derivatization high performance liquid chromatography method for detecting Methods dimethyl sulfate (DMS) in workplace air. DMS in workplace air was collected with mercaptopyridine impregnated （ silicone tube. The derivative of DMS and mercaptopyridine was eluted by mobile phase phase A: water, phase B: acetonitrile, ∶ the volume ratio was 40 60) , and separated with a C18 column, then detected with diode array detector and quantitated by a Results - standard curve. The linear range of DMS was 0.17 40.00 mg/L, with the correlation coefficient of 0.999 95. The detection limit and the lower limit of quantitation were 0.05 and 0.17 mg/L respectively. The minimum detection concentration and minimum quantitation concentration were 0.02 and 0.04 mg/m³, respectively (air sample volume of 4.5 L, 1.0 mL sample - - - solution). The average desorption efficiency was 98.40% 102.00%. The within run and between run relative standard deviations - - were 0.61% 3.92% and 1.71% 6.00%, respectively. The samples could be stored at room temperature for at least 14 days. Conclusion This method can be used to detect DMS in workplace air.

Abstract: Nitrobenzene compounds (NBCs) are widely used in the world. It has 40 isomers such as nitrobenzene, dinitrobenzene and nitrotoluene, that are highly toxic and difficult to degrade and can cause harm to human health in different degrees. At pres⁃ ent, there is no unified standard method and occupational exposure limit for the detection of NBCs in the air. In terms of sampling medium, solid adsorption tube is mostly used for trapping vapor state NBCs, and filter membrane and solid adsorption tube are mostly used in series for sampling coexist NBCs in vapor state and aerosol state. In the detection methods, gas chromatography and liquid chromatography are common, and ultraviolet spectrophotometry, Raman spectroscopy, ion migration spectrometry and some other rapid response methods and technologies are also used in the detection of NBCs. In the detection of NBCs by gas chro⁃ matography, capillary column separation is commonly used, and the main detectors are flame ionization detector, electron capture detector and mass spectrometry detector. It is of practical significance to establish a method with high sensitivity, strong practica⁃ bility, convenient operation, and can simultaneously collect and detect a variety of NBCs in different states.

The paper is aimed to search more natural plant antioxidants and further research and develop new medicinal plant resources in Guizhou. The Guizhou special miao medicine "bod zangd dak" was extracted with 60% ethanol. The antioxidant activity of the different polarity components separated from the extract was tested by DPPH method with ascorbic acid as positive control. The results showed that the IC50 of the different polarity components was as following: ascorbic acid (0.033 4 g x L(-1)) < ethyl acetate components (0.052 3 g x L(-1)) < total tannins components (0.054 9 g x L(-1)) < 60% ethanol extraction components (0.076 7 g x L(-1)) < butanol extraction components (0.110 g x L(-1)) < water-soluble polysaccharides components (0.168 g x L(-1)) < water extraction components (0.174 g x L(-1)) < water components after extraction (0.226 g x L(-1)) < total polysaccharides components (0.645 g x L(-1)). It is concluded that the different polarity components have different free radical scavenging activity and that provides a scientific basis for further search of the active ingredients and the activive mechanism.
Antioxidants ; chemistry ; isolation & purification ; Biphenyl Compounds ; chemistry ; China ; ethnology ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Free Radicals ; chemistry ; Medicine, Chinese Traditional ; Picrates ; chemistry ; Plant Roots ; chemistry ; Plant Stems ; chemistry ; Smilax ; chemistry

Objective - - To prepare the GDH 5 air sampling tube for simultaneous collection of eight kinds of chloro nitrobenzene （ ） ， compounds CNBs in the air of workplace and establish a matching determination method using gas chromatography. Methods - - ， Eight kinds of CNBs in vapor and aerosol state were collected by self developed GDH 5 air sampling tube desorbed ， ， ， by toluene separated by polysiloxane gas chromatography column detected by microcell electron capture detector and Results - （ - quantified by external standard method. It was determined that the air sampling tube was assembled by XAD 2 ion ） - ， exchange resin and glass fiber filter membrane. The linear range of CNBs was 0.80 240.00 mg/L and the linear correlation - - coefficients were greater than 0.999 9. The detection limit was 7.87 13.03 μg/L. The minimum detectable concentration was 0.60 3， - 3（ ） 1.33 μg/m and the minimum quantitative concentration was 2.00 4.22 μg/m sample 45.00 L . The average desorption - - （RSD） - ， - RSD efficiency was 101.2% 110.0%. The within run relative standard deviation was 0.8% 4.1% and the between run - Conclusion - was 0.3% 5.8%. The samples could be stored for more than 30 days at room temperature. GDH 5 air sampling tube and its associated determination method can be used for the collection and determination of eight kinds of CNBs in workplace air.

Objective To investigate the prevalence and associated risk factors of diabetes mellitus in populations of Hans and Kazaks in Xinjiang. Methods A total of 7 299 Hans and Kazaks adults from Shihezi, Xinyuan County of Yining city, and Shawan town of Tacheng City were surveyed. The data were collected according to questionnaire and physical examination and laboratory test. Results The prevalence rates of diabetes mellitus for male, female and all subjects were 8. 14% , 7. 77% , 7. 93% (Hans), and 7. 41% , 4. 90% , 5. 89% (Kazaks), respectively in Hans and Kazaks, Standardized rates were 6. 40% , 7. 06% , 6. 66% (Hans), and 5. 87% , 4. 60% , 5. 28% ( Kazaks), respectively . The prevalence rates of impaired fasting glucose( IFG) were 9. 54% , 8. 08% , 8. 70% ( Hans), and 12. 18% , 8. 62% , 10. 03% ( Kazaks), respectively. Standardized rates were 7. 04% , 7. 23% , 8. 54% ( Hans), and 10. 12% , 8. 09% , 9. 31% ( Kazaks), respectively. Old age, hypertension, dyslipidemia, overweight and obesity, and central obesity were risk factors for diabetes mellitus. Conclusion The prevalence rates of diabetes mellitus and IFG in Hans and Kazaks are higher than those in ethnic minorities in other region. Primary or secondary prevention should be implemented in time.

Objective - To analyze the prevalence and influencing factors of work related musculoskeletal disorders (WMSDs) Methods among painters in the manufacturing industry. A total of 639 painters from one shipbuilding enterprise, one automobile manufacturing enterprise and three wooden furniture manufacturing enterprises in Guangdong Province were selected as the research subjects using typical sampling method. The Chinese version of Musculoskeletal Disorders Questionnaire was Results used to investigate the prevalence of WMSDs in the past one year, and the influencing factors were analyzed. The total prevalence rate of WMSDs among painters in the manufacturing industry was 37.4%. The prevalence of WMSDs in different vs vs P industries from high to low was shipbuilding, automobile and furniture manufacturing (50.0% 38.7% 29.0%, <0.01). The prevalence of WMSDs in different parts of the body from high to low was neck, ankle/foot, shoulder, low back, upper back, knee, vs vs vs vs vs vs vs vs P hand/wrist, hip/leg and elbow (20.7% 19.2% 17.4% 15.8% 14.1% 13.8% 13.5% 9.5% 6.6%, <0.01). Multivariate logistic regression analysis results showed that working in uncomfortable postures was a risk factor for neck, ankle/ P P foot and shoulder WMSDs (all <0.01); long time head turning was a risk factor for neck and shoulder WMSDs (both <0.05); P overweight and obesity, and bending and turning frequently at the same time were risk factors for ankle/foot WMSDs (all <0.05); P adequate rest time was a protective factor for neck and ankle/foot WMSDs (both <0.01); participated in physical exercise more P than once a week was a protective factor of neck and shoulder WMSDs in painters (all <0.05), after excluding the influence of Conclusion confounding factors. The prevalence of WMSDs in manufacturing painters was high, and the main body parts E mail 4813545@qq.com E mail wangzhongxu2003@163.com· · 中国职业医学 年 月第 卷第 期 ， ， ， 482 2022 10 49 5 Chin Occup Med October 2022 Vol.49 No.5 involved were neck, ankle/foot and shoulder. The influencing factors include individual factors, poor ergonomics factors and unreasonable work organization.

Objective To detect the expression levels of high mobility group box chromosomal protein 1 (HMGB1) and Th17 cells transcription factors, related cytokines in peripheral blood of rheumatoid arthritis (RA) patients and analyze the relations between HMGB1 and CRP, ESR, RF in RA patients. The other aim of this study is to identify the expression level of HMGBI and the relationship between HMGB1 and Th17 in RA patients. Methods The mRNA levels of HMGB1, RORyt, interleukin (IL)-17 in the peripheral blood mononuclear cells (PBMC) were determined by quantitative real-time PCR (QRT-PCR) from 80 patients with rheumatoid arthritis,including 32 RA patients in stable phase and 48 patients in active phase, and 50 healthy volunteers. The concentration of HMGB1, IL-23, IL-17 in plasma were detected by enzyme linked immunosorbent assay (ELISA), one-way ANOVA and Spearman's correleation were adopted for statistical analysis.Results The mRNAs of HMGBI, RORyt and IL-17 in RA patients were higher than that in healthy control group (P<0.05), especially in active RA patients [ HMGB 1 (0.424±0.262) pg/ml, RORγt (0.34±0.25) pg/ml,IL-17 (1.42±0.38) pg/ml,P<0.01 ] when compared with patients with stable disease. The concentration of HMGB1, IL-23 and IL-17 in the plasma of RA patients was higher than that of the healthy control group (P< 0.05), and was positively correlated with the expression levels of HMGB1, Th 17-associated factors and the level of CRP, ESR, RF in RA patients' plasma(P<0.05). Conclusion The HMGB1 and Thl7 cells levels are higher in active RA patients than those in patients with stable disease, arid there is significant positive correlation between them. Detection of peripheral HMGB1 and Thl7 cell-specific transcription factors or related cytokines can help to understand the development and progress of rheumatoid arthritis and provide clues for new treatment targets for RA.

Hip Joint ; diagnostic imaging ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Ossification, Heterotopic ; diagnostic imaging ; pathology ; surgery ; Radiography

OBJECTIVETo analysis the homology among the extended-V region of the surface proteins in different serotype Streptococcus mutans (c, f, d, g) and to find out it's significance in anti-caries vaccine.

METHODSThe DNA of the bacteria (standarded serotype c, d, f, g and partial serotype c clinicals) was extracted and the extended-V region (SrV+, 1 384-2 514 bp) was amplified using polymerase chain reaction (PCR). Then the products were assessed using restriction fragment length polymorphism (RFLP) by endonuclease Dde I. The genotypings were sequenced and analysised using the program of BLAST on NCBI Gene Bank database.

RESULTSAbout 1.13 kb fragments were produced both in serotype c and f, the serotype d and g were failed. The RFLP results showed that five different patterns(A, B, C, D, E) among the 117 PCR products were reveled by Dde I. The ration of the genotypings A and B were the most among the strains, the C was lower, the D and E respectively was 1 and 3 strains per genotype. OMZ175 (serotype f) was belong to B genotype. Selected one of the A, B, C genotypings to sequenced and blasted. Then the results of the blastn showed that the identities of the gene sequence were 92%-98% between the serotype c and serotype f, part sequence of the serotype g was homology with the SrV+ of the serotype c, the protein sequence among serotype c, d, f, g were 77%-82%.

CONCLUSIONIt is reasonable to use some putative pipetides to study the anti-caries vaccine among the extended-V regions of the surface proteins in different serotype (c, d, f, g) in S. mutans.

OBJECTIVETo preliminarily investigate the relationship between the Lactate dehydrogenase (LDH) activity of Streptococcus mutans (S. mutans) and dental caries initiation.

METHODS100 S. mutans strains derived from caries-active and caries-free individuals were cultured in BHI medium supplemented with glucose. Cells were extracted and ruptured, and the extracted liquid protein was quantified with Coomassie brilliant blue G250 staining methods. LDH activity was assayed using the pyruvate-dependent oxidation of NADH-with and without FDP.

RESULTSLDH activity of the two groups strains had no difference (P > 0.05), but the distribution of differ class enzyme activity strains in the two groups was different (P < 0.05).

CONCLUSIONLDH activity of S. mutans is correlated to the initiation of dental caries to some extent. The measurement methods in this study can be applied in preliminary quantitation of LDH activity and the screening of S. mutans strains.