1,3-propanediol (1,3-PD) is an important material for chemical industry, therefore, there is much interest in the production of 1,3-PD. The gene dhaT encoding 1, 3-propanediol dehydrogenase ( PDOR) of Citrobacter freundii was amplified by PCR. Sequence analysis of the similarity at the nucleotide and amino acid level between the gene encoding C. freundii PDOR and that of C. freundii ( U09771 ) were 78% and 90% , respectively. The recombinant plasmid pSE-dhaT was constructed by inserting dhaT gene into expression vector pSE380 and then transformed E. coli JM109. The recombinant strain was induced by IPTG to express dhaT. Further more the recombinant enzyme was purifed from recombinant E. coli by Ni-nitrilotriacetate affinity chromatography followed by Sephacral S-300 gel filtration. A single obvious protein about 42kDa could be obtained by the sodium dodecyl sulfate-polyacrylamide gel electrophoresis of recombinant enzyme. The purified enzyme was used to determined enzyme property on the substrate of propionaldehyde and 1, 3-PD. The optimal temperature and optimal pH of the purified enzyme were 37℃, 8.0 for reduction and 25℃, 10. 5 for oxidation, respectively; and the kinetic property of PDOR about Km and V max were 10. 05mmol/L, 37. 27?mol/min/mg for propionaldehyde and 1. 28mmol/L, 25. 55?mol/min/mg for 1,3-PD, respectively; The deduced dhaT gene product (388 amino acids) showed a specific reduction activity of 49. 50U/mg and oxidation activity of 79. 92U/ mg. There also have a putative iron-binding motif ( G-XX-H-X-X-A-H-X-X-G-X-X-X-X-X-P-H-G) as a fingerprint pattern in the recombinant enzyme, the motif is fully conserved among these 1, 3-propanediol dehydrogenase. It is beneficial to the researches of high producing 1, 3-propanediol by gene engineering strain.

OBJECTIVETo study the biological exposure index of carbon disulfide in China.

METHODSHigh-performance liquid chromatography (HPLC) was used to detect the levels of 2-thiothiazolidine-4-carboxylic acid (TTCA) in the urine of the workers after working shift end, Gas chromatography was used to detect the concentrations of the carbon disulfide in the workplace air. The relationship between the urine TTCA levels and the concentrations of the carbon disulfide was analyzed, the biological exposure index and judgement result from PC-TWA were compared.

RESULTSThe levels of TTCA in urine of workers occupationally exposed to carbon disulfide were closely and positively related with the concentrations of the carbon disulfide in the workplace air. The regression equation was Y = 0.265X - 0.165, The biological exposure index of carbon disulfide were calculated by regression equation according to occupational exposure limits of carbon disulfide in China.

CONCLUSIONThe biological exposure index of CS(2) in China might be revised for 1.2 mg/g Cr.

Carbon Disulfide ; analysis ; Chromatography, Gas ; Environmental Monitoring ; Humans ; Occupational Exposure ; analysis ; Thiazolidines ; urine ; Threshold Limit Values ; Workplace

OBJECTIVETo investigate the exposure levels of carbon disulfide (CS(2)) for a chemical fiber industry.

METHODSThe concentration of CS(2) was monitored in representative workshops and types of work, and the datas of that over the years were collected.

RESULTSThe short-term exposure concentration of CS(2) about 80% of the type of work was less than or equal to 10 mg/m(3), which of more than 90% was less than or equal to 20 mg/m(3). The time weighted average concentration of CS(2) about 70% of the type of work was less than or equal to 5 mg/m(3), which of more than 90% was less than or equal to 10 mg/m(3). The short-term exposure concentration of CS(2) which was more than 15 mg/m(3) or the time weighted average concentration of CS(2) which was more than 30 mg/m(3) was only for little type of work.

CONCLUSIONThe concentration of CS(2) for the most type of work was lower, but there were still a number of types of work exposuring the higher concentration, which exceed the national occupational exposure limits.

Carbon Disulfide ; analysis ; Chemical Industry ; Humans ; Occupational Exposure ; analysis ; Workplace

OBJECTIVETo study the effects of long-term exposure to carbon disulfide (SC(2)) on cardiovascular system of workers.

METHODSThe concentrations of CS(2) were detected in the representative workshops with different exposure levels. The indicators related to cardiovascular system were tested in 633 workers occupationally exposed to CS(2), which included blood pressure, electrocardiogram, blood routine (blood RT), cholesterol (TCHO), triglyceride (TG) and so on. The data were analyzed by chi-square test and multiple logistic regression analysis.

RESULTSThe exposure concentration of CS(2) for 389 workers was less than or equal to 5 mg/m(3), which for other 244 workers was higher than 5 mg/m(3). The maximum exposure concentration of CS(2) was 15.73 mg/m(3). There were no significant effects of CS(2) on the electrocardiogram, red blood cells, white blood cells, blood platelet, TCHO and TG of workers. However, the positive effects of CS(2) on blood pressure and negative effects of CS(2) on hemoglobin were found. The rates of high TCHO, TG and hypertension in male workers were significantly higher than those in female workers (P < 0.05). The rates of high TCHO, hypertension and sinus arrhythmia in older workers (≤ 30 years old) were significantly higher than those in young workers (> 30 years old) (P < 0.05). The rate of sinus arrhythmia in workers with 1 - 10 working years was significantly higher than that in workers with more than 10 working years (P < 0.05). The rate of hypertension in workers with 1 - 10 working years was significantly lower than that in workers with more than 10 working years (P < 0.05).

CONCLUSIONThere were no significant effects of CS(2) exposure on the indexes of cardiovascular system of workers.

Adult ; Blood Pressure ; Carbon Disulfide ; adverse effects ; Cardiovascular System ; drug effects ; physiopathology ; Erythrocyte Count ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure ; analysis ; Risk Factors ; Young Adult

OBJECTIVETo analyze the distribution of the musculoskeletal disorders, work load and working postures in different factories, gender, education levels, age and working years among manufacturing workers.

METHODSIn a cross-sectional study of 5134 manufacturing workers in 12 factories, the morbidities for musculoskeletal disorders in one year period were measured with questionnaires.

RESULTSThe morbidities for musculoskeletal disorders in body sites: waist, neck, shoulder, wrist, ankle/feet, knee, hip/buttocks and elbows were 59.7%, 47.9%, 38.1%, 33.7%, 26.9%, 25.4%, 15.2%, and 14.9%, respectively in one year period. There were significant differences of morbidities for musculoskeletal symptoms in body sites of workers among different factories (P < 0.05 or P < 0.01). The morbidities of musculoskeletal symptoms in elbows, waist, wrists and ankle/feet of the workers in refractory material and chemical fiber factories were higher than those in other factories, the morbidities for musculoskeletal symptoms of workers in garments and diamond factories were lower than those in other factories. The morbidities for musculoskeletal symptoms in neck, shoulders and wrists of female workers were significantly higher than those of male workers (P < 0.01). There were significant differences of the morbidities for musculoskeletal symptoms in body sites among workers with different educational levels (P < 0.05 or P < 0.01). There were significant differences of the morbidities for musculoskeletal symptoms in neck, shoulders, wrists, hip/buttocks and knee among groups with different age or different working years (P < 0.01), and the morbidities for musculoskeletal symptoms increased with age and working years. The proportions of unhealthy working postures and high working load among workers in refractory material and chemical fiber factories were higher; but those in garments and diamond factories were lower.

CONCLUSIONThe morbidities for musculoskeletal symptoms in waist, neck, shoulder and wrists of workers in manufacturing workers were higher; the gender, education level, age and working years could influenced the morbidities for musculoskeletal disorders.

Adult ; Female ; Humans ; Industry ; Male ; Musculoskeletal Diseases ; epidemiology ; Occupational Diseases ; epidemiology ; Posture ; Surveys and Questionnaires

The anhydrite and gypsum are the main sulfate minerals during evaporation of seawater or lake.They record the information about relative hydrogeology and the composition of mother liquor.Boron is diffluent element, and often occurs in all kinds of evaporites.Presently, the boron isotope has been applied widely in mineral deposits forming, geochemistry and palaeoenvironment.However, there is little research about characteristic of boron isotope in anhydrite and gypsum minerals, because of the low content of boron and micro-solubility in water and hydrochloric acid.This study developed a method of extracting and purifying boron in anhydrite and gypsum by phase transformation and ion-exchange.Firstly, the samples were mixed with ammonium hydrogen carbonate to transform the calcium sulfate to calcium carbonate.And diluted hydrochloric acid (1 mol/L) was added to resolve calcium carbonate.The percent conversion was about 85%in the first stage, and up to complete resolution by repeating this process.Secondly, boron specific ion-exchange resin ( Amberlite IRA 743 ) was used to gather the boron ions fully and further refined the samples with more than 1 μg of boron by anionic and cationic resin mixed by Ion Exchange Ⅱ and Dowex 50 W × 8.Finally, according to the modified method by He, the values of boron isotope were determined by TIMS.The boron content is analytically pure gypsum was 3.501 ± 0.128 μg/g ( n=12 , RSD=3.6%) and the average recovery was 100.47%.Besides, the δ11B value of analytically pure gypsum added with NIST SRM 951 was 17.98‰±0.21‰ (n=3, RSD=1.2%).This method has good repeatability and can meet the requirements of boron isotopic measurement of anhydrite and gypsum.

OBJECTIVETo investigate the application value of chemiluminescence method (CMIA) detection of Treponema pallidum (TP) specific antibodies in the blood test.

METHODSOver the same period the de novo enzyme linked immunosorbent assay (ELISA) and Abbott chemical luminescence method were used to detect the specific antibody of syphilis in a total of 66298 samples; TP-ELISA negative and TP-CMIA positive unpaid blood donation blood samples for syphilis specific antibody were detected and confirmed by Western blot.

RESULTSBlood samples from 66298 blood donors were detected by TP-ELISA, the positive samples was 250 and the positive rate was 0.38%. The positive samples of TP-CMIA was 297, the positive rate was 0.45%, the difference was statistically significant (P<0.05). The blood samples of 47 unpaid blood donors were confirmed by TP-Western blot method, as a result, 32 samples were positive, 15 were negative, and result detected by TP-ELISA method was negative.

CONCLUSIONTP-CMIA sensitivity is higher than that of TP-ELISA, and possesses higher sensitivity and specificity, and quick detection, simple operation, easy automation, suggesting greater application value in blood detection of Treponema pallidum.