Analysis on risk factor of chronic disease-related behaviors among adult residents in Liubei District, Liuzhou City / 中华疾病控制杂志

Objective To explore the risk factor of chronic disease-related behaviors such as smoking, drinking, exercising and eating habit among residents in Liubei District, Liuzhou City. Methods 2 487 adult residents in Liubei District were sampled by multistage sampling method and surveyed on their way of life and behavior risk factors. The content of questionnaire involved familial population information, past medical history, way of life and eating habit. EpiData 3.1 was applied to install database, SPSS 17.0 was used for data analysis, multivariate Logistic regression was used to analyze the risk factor of chronic disease-related behaviors. Results The rates of hypertension, diabetes, stroke, chronic obstructive pulmonary disease (COPD) were 13.63%，4.22%，3.62%,0.36% and 6.84%, respectively. The rate of smoking, drinking, doing physical exercise and eat breakfast regularly were 22.92%, 5.43%，52.87% and 93.07%. Multivariate Logistic regression analysis showed that older and smoking were risk factors of chronic disease, while physical exercise was protective factor of chronic disease. Conclusions Intervening measure taken in chronic disease demonstration zone were effective in the past 5 years， and health education on behavioral intervention should be carried on continuous to reduce incidence of chronic disease.

Risk assessment on occupational hazards in automobile maintenance industry / 预防医学

Objective To investigate the occupational hazards in automobile maintenance industry in Hangzhou and to provide field-research based evidence for prevention and control. Methods We visited 12 workshops of automobile maintenance to investigate the actors of occupational hazards, examine the protective facilities, and evaluate the occupation-related risk using MES method. Results The factors of occupation-related hazards at polishing posts met the criteria. At the painting posts in the painting room, the factors of chemical hazards satisfied the criteria, however, the levels of xylene and butyl acetate exceeded the standard lines in some enterprises when the ventilation system was close. The noise was higher than the limit at a few posts of sheet metal. The ventilation in spray paint room and the dust collector in dry mill room work well. The risks of occupational hazards at grinding, painting, and sheet metal posts were slightly harmful. Conclusion The occupational hazard factors in automobile repair enterprises were much more complicated. The noise hazard of the sheet metal posts was relatively prominent.

Effect of Hedgehog Signaling Pathway Abnormality on Chemothe-rapeutic Resistance of Multiple Myeloma / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To study the correlation between the excessive activation of Hedgehog signal and the drug resistance of multiple myeloma.</p><p><b>METHODS</b>The resistant cell line RPMI 8226/R of multiple myeloma was established by an ascending concentration gradient method. The experiment consisted of 4 groups: RPMI8226/R, RPMI8226/S, GANT61+RPMI8226/R and GANT61+RPMI8226/S. The CCK-8 (cell counting kit-8) assay was used to detect the cell proliferation inhibition rate in 4 groups; the RT-PCR was used to detect the expression of Gli1, Gli2, Shh, Ihh, Smo and Sufu in the RPMI8226/S and RPMI8226/R cells. The Western blot was used to detect the expression of the resistant protein Cyclin D1, P21 and BCL-2 and MDR-related signaling pathways protein p-Akt, p-MAPK and STAT3 in the RPMI8226/S and RPMI8226/R cells. After adding different concentration of GANT61, the Western blot was used to detect the expression of Gli2 in RPMI8226/R and RPMI8226/S cells.</p><p><b>RESULTS</b>The expression of Shh, Ihh, Smo Gli2 was enhanced significantly in the RPMI8226/R cells, but the expression of Sufu inhibitor was reduced, the expression level of related protein in Hedgehog signaling pathway was significanly higher in RPMI8226/R than that in RPMI8226/S. After theatment of GANT61 in vitro, the expression level of Gli2 in multiple myelom cells obviously decreased, the decreasing effect of GANT61 on Gli2 expression in RPMI8226/R cells was more significant than that in RPMI8226/S cells. The sensitivity of RPMI8226/R cells to DOX after treatment with GANT61 (IC) was risen from 7.11±0.061 µmol/L to 0.99±0.053 µmol/L, the corresponding cell resistance index decreased from 5.51 to 1.69.</p><p><b>CONCLUSION</b>the activation of Hedgehog signaling pathway is closely related with the resistance of multiple myeloma cells, and GANT61 can block the Hedgehog signaling pathway, thus Hedgehog signaling may be used as a new target for multiple myeloma treatment.</p>

Identification of Haploid Maize Kernel Using NIR Spectroscopy in Reflectance and Transmittance Modes: A Comparative Study.

The spectra measurements mode that suitable for haploid maize kernel identification was explored using MicroNIR-1700 series of miniature near infrared spectrometer by JDSU company. Based on Near Infrared Spectroscopy (NIRS) qualitative analysis techniques, we conducted a comparative study using reflectance and transmittance spectra to identify haploid maize kernels. Partial least squares-discriminant analysis (PLS-OLDA) was used to compress the pretreated spectral data, and then the identification models were built based on Support Vector Machine (SVM). The measured data were recorded in reflectance and transmittance modes and the recognition correct rates were calculated. For measurements taken in reflectance mode, the average recognition rate was less than 60% regardless of embryo side positions. In transmittance mode, however, the average recognition rate reached 93.2%. The experiment results show that diffuse reflection spectrum could only obtain corn grain surface information, so embryo side positions severely affect haploid maize kernel identification effect when reflectance measurements mode have been employed, but they have far less impact on transmittance mode. The near infrared diffuse transmittance spectra analyzes non-uniform samples can achieve the analysis of optical path depth information accumulation, all information of the sample interior can be obtained, so transmittance spectra could identify haploid maize effectively and be desensitized to kernel positions. NIRS qualitative analysis techniques with features of rapid, nondestructive could identify the haploid and Micro-NIR spectrometer scan fast and cost less, which have utility for automatically selecting haploid maize kernels from hybrid kernels.

[Study of Modeling Samples Selection Method Based on Near Infrared Spectrum].

For more wheat varieties classification problem, we use near infrared spectrumto do qualitative analysis. Increasing the size of modeling sample could increase information of the model, however, at the same time, it also makes information redundancy so that modeling time and storage space will increase, thus, we need to decrease the size of modeling sample though selecting them. Some information must be lost and the effects of the model must be worse if we select samples blindly. We put forward the k nearest neighbor-density sample selection based on the traditional selection methods. Experiments use the near infrared diffuse reflection spectrum of wheat seed from lots of days. First, we use preprocessing and feature extraction to deal with the wheat original spectrum, then select modeling sample by three methods that are random sampling, k nearest neighbor and k nearest neighbor-density, finally, we establish the models of BPR(Biomimetic Pattern Recognition) and BPRI(Biomimetic Pattern Recognition Improved). The experimental results show that in the model of BPR we get the best results using the selection method of k nearest neighbor-density, especially it also decreases the size of modeling sample deeply, and in the model of BPRI the results using the selection method of k nearest neighbor-density are much better than random sampling and a little better than k nearest neighbor, but in the meanwhile the size of modeling sample using the selection method of k nearest neighbor-density are much smaller than k nearest neighbor. The experimental results prove that the sample selection method of k nearest neighbor-density can not only greatly reduce the modeling sample size, and ensure the quality of the model, it has obvious effect on varieties classification problem of wheat.

[Detection of Adulteration in Milk Powder with Starch Near Infrared].

Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together to construct a model, the CAR-T of mixed starch content of a sample may reach 0.1%, the CRR-T can reach 1%, if the model construction and predicting were performed with near infrared spectrum data tested in a same day. However, the CAR-T can just stably reach up to 5% and the CRR-T have the same result, if the model construction and predicting were crossly performed with mixed near infrared spectrum data tested in different days. Furthermore, the correct recognizing threshold mixed starch of a sample can stably reach up to 1% and the CAR-T can reach 5%, if the model construction was based on near infrared spectrum data combined the previous four days to predict the output of the another day. On the other hand, we also engaged quantitative analysis to the starch content in milk power with two kinds of arithmetic (PLSR, LS-SVR). In contrast with the testing outputs, the reliability of both the CAR-T and CRR-T in qualitative analysis was further validated.

[Maize Hybrid Seed Purity Identification Based on Near Infrared Reflectance (NIR) and Transmittance (NIT) Spectra].

This article explore the feasibility of using Near Infrared Reflectance (NIR) and Transmittance (NIT) Spectroscopy (908.1-1677.2 nm wavelength range) to identify maize hybrid purity, and compare the performance of NIR and NIT spectroscopy. Principle Component Analysis (PCA) and Orthogonal Linear Discriminant Analysis (OLDA) were used to reduce the dimension of spectra which have been pretreated by first derivative and vector normalization. The hybrid purity identification model of Nonghua101 and Jingyu16 were built by SVM. Models based on NIR spectra obtained correct identification rate as 100% and 90% for Nonghua101 and Jingyu16 respectively. But NIR spectra were greatly influenced by the placement of seeds, and there existed significant difference between NIR spectra of embryo and non-embryo side. Models based on NIT spectroscopy yielded correct identification rate as 98% both for Nonghua101 and Jingyu16. NIT spectra of embryo and non-embryo side were highly similar. The results indicate that it is feasible to identify maize hybrid purity based on NIR and NIT spectroscopy, and NIT spectroscopy is more suitable to analyze single seed kernel than NIR spectroscopy.

Discrimination of Maize Haploid Seeds from Hybrid Seeds Using Vis Spectroscopy and Support Vector Machine Method.

Doubled haploid (DH) lines are routinely applied in the hybrid maize breeding programs of many institutes and companies for their advantages of complete homozygosity and short breeding cycle length. A key issue in this approach is an efficient screening system to identify haploid kernels from the hybrid kernels crossed with the inducer. At present, haploid kernel selection is carried out manually using the"red-crown" kernel trait (the haploid kernel has a non-pigmented embryo and pigmented endosperm) controlled by the R1-nj gene. Manual selection is time-consuming and unreliable. Furthermore, the color of the kernel embryo is concealed by the pericarp. Here, we establish a novel approach for identifying maize haploid kernels based on visible (Vis) spectroscopy and support vector machine (SVM) pattern recognition technology. The diffuse transmittance spectra of individual kernels (141 haploid kernels and 141 hybrid kernels from 9 genotypes) were collected using a portable UV-Vis spectrometer and integrating sphere. The raw spectral data were preprocessed using smoothing and vector normalization methods. The desired feature wavelengths were selected based on the results of the Kolmogorov-Smirnov test. The wavelengths with p values above 0. 05 were eliminated because the distributions of absorbance data in these wavelengths show no significant difference between haploid and hybrid kernels. Principal component analysis was then performed to reduce the number of variables. The SVM model was evaluated by 9-fold cross-validation. In each round, samples of one genotype were used as the testing set, while those of other genotypes were used as the training set. The mean rate of correct discrimination was 92.06%. This result demonstrates the feasibility of using Vis spectroscopy to identify haploid maize kernels. The method would help develop a rapid and accurate automated screening-system for haploid kernels.

[Near infrared spectroscopy analysis method of maize hybrid seed purity discrimination].

Near infrared spectroscopy analysis method of discrimination of maize hybrid seed purity was studied with the sample of Nong Hua 101 (NH101) from different origins and years. Spectral acquisition time lasted for 10 months. Using Fourier transform (FT) near infrared spectroscopy instruments, including 23 days in different seasons (divided into five time periods), a total of 920 near infrared diffuse reflectance spectra of single corn grain of those samples were collected. Moving window average, first derivative and vector normalization were used to pretreat all original spectra, principal component analysis (PCA) and linear discriminant analysis (LDA) were applied to reduce data dimensionality, and the discrimination model was established based on biomimetic pattern recognition (BPR) method. Spectral distortion was calibrated by spectra pretreatment, which makes characteristics spatial distribution range of sample spectra set contract. The relative distance between hybrid and female parent increased by nearly 70-fold, and the discrimination model achieved the identification of hybrid and female parent seeds. Through the choice of representative samples, the model's response capacity to the changes in spectral acquisition time, place and environment, etc. was improved. Besides, the model's response capacity to the changes in time and site of seed production was also improved, and the robustness of the model was enhanced. The average correct acceptance rate (CAR) of the test set reached more than 95% while the average correct rejection rate (CRR) of the test set also reached 85%.

[Feasibility study on an approach for identifying corn kernel varieties with seed coating agents via near infrared spectroscopy].

It is generally accepted that near infrared reflectance spectroscopy (NIRS) can be used to identify variety authenticity of bare maize seeds. In practical, maize seeds are covered with seed coating agents. Therefore it's of huge significance to investigate the feasibility of identifying coated maize seeds by NIRS. This study employed NIRS to quickly determine the variety of coated maize seeds. Influence of seed coating agent on NIR spectra was discussed. The NIR spectra of coated maize seeds were obtained using an innovative method to avoid the impact of the seed coating agent. Coated seeds were cut open, and the sections were scanned by the spectrometer, so as to acquire the information of the seed itself. Then, support vector machine (SVM), soft independent modeling of class analogy (SIMCA), and biomimetic pattern recognition (BPR) was employed to establish the identification model for four maize varieties, and yield 93%, 95.8%, 98% average correct rate respectively. BPR model showed better performance than SVM and SIMCA models. The robustness of identification model was tested by seeds harvested from four regions and model showed good performance.

Molecular mechanism of Doxorubicin resistance in multiple myeloma cell line / 中国实验血液学杂志

This study was aimed to investigate the molecular mechanism of doxorubicin resistance in multiple myeloma cell line and certify the effect of Notch signal over-expression on drug resistance of myeloma cells. The doxorubicin RPMI 8226 cell line (RPMI8226/DOX) was established by culturing 8226 cells with continuous low concentration and intermittent gradually-increasing-concentration of doxorubicin in vitro, the mRNA expression of Notch2,Jagged1, Jagged2, HES1 were measured by RT-PCR and the P-170 protein expression was detected by Western blot in RPMI 8226 cell line; the changes of IL-6 and VEGF were tested by ELISA. The results showed that the Notch mRNA expression (Notch2, Jagged1, Jagged2 increased gradually along with the increase of chemotherapeutic drug resistance, but the expression of HESI mRNA gradually decreased along with the increase of drug resistance. The expression level of P-170 protein was upregulated gradually along with the increase of drug resistance. The level of VEGF and IL-6 in culture supernatants of RPMI8226/DOX was higher than that in RPMI 8226. It is concluded that the establishment of RPMI 8226/DOX cell line is a useful model to analyze the mechanism of chemotherapeutic drug resistance in multiple myeloma, Notch activation is closely correlated with the drug resistance of multiple myeloma and Notch signaling may to be used as a new target for multiple myeloma treatment.

Expression of SLC25A38 in leukemic cells from children with acute lymphoblastic leukemia / 中国实验血液学杂志

This study was aimed to investigate the SLC25A38 expression in pediatric patients with acute lymphoblastic leukemia (ALL) and its clinical significance. A total of 23 newly diagnosed ALL pedictric patients were enrolled in test group, 10 pediatric patients with non-hematologic malignancies were selected as control group. The expression in protein and mRNA levels of SLC25A38 were detected by Western blot and real-time PCR respectively. The results showed that the SLC25A38 protein was positive in 8 of 23 pediatric ALL patients (34.78%), while no positive case was found in 10 controls. The relative expression level of SLC25A38 mRNA was 0.4673 ± 0.05344 in SLC25A38-protein positive group of ALL patients, while that was 1.296 ± 0.2517 in SLC25A38-protein negative group of ALL patients. The expression level of SLC25A38 mRNA in SLC25A38-protein positive group was significantly lower than that in negative group (P = 0.001) . No statistically significant difference was found in comparison of SLC25A38-protein negative group of ALL patients with the control group (P = 0.1097). The analysis of clinical data showed that there were significantly differences in sex, immunophenotype, initial peripheral white blood cell count and LDH between the SLC25A38-protein positive and SLC25A38-protein negative groups (P < 0.05). It is concluded that as a novel protein, SLC25A38 highly expressed in pediatric ALL patients, indicating that SLC25A38 may serve as a molecular marker and potential therapeutic target for acute lymphoblastic leukemia in children.

[Study on method of maize hybrid purity identification based on hyperspectral image technology].

The feasibility of employing hyperspectral image technology to identify maize hybrid purity was studied by analyzing the spectral information of maize hyperspectral image. The hyperspectral images of hybrid and female parent of maize variety NH101 in the range of 871-1 699 nm including 308 wavelengths were collected by hyperspectral imaging system. We extracted average spectral information of interested region on maize seed and built identification models of hybrid and female parent of maize variety NH101 based on processed spectral data. The influences of different sample laying modes (seed embryo facing the light source, seed embryo backward light source, and seed put in different locations on sample stage) and experimental environments on the performance of identification models were discussed. Spectral collected under different sample laying modes and experimental environments were used to test the robustness of identification models. The average correct acceptance rates and average correct rejection rates are more than 90%. The feature spectral bands (1 195-1 246 nm) with which the differences between hybrid and female parent are the largest were extracted by a wavelength selection method based on standard deviations, called Qs. The performance of identification models built based on spectral data in feature spectral bands reached the same level of models built based on spectral data in the full range of 925-1 597 nm. The results demonstrated the feasibility of using hyperspectral image technology as an objective and rapid method for the identification of maize hybrid purity.

[The utility research on NIR diffuse reflectance and transmittance measurements mode in authenticity identification of maize population samples].

In the present paper, the spectral measurements of maize population samples were researched so as to identify their authenticity. Diffuse reflectance and transmittance measure modes were used to collect spectral data of 8 maize varieties. DPLS-DA was used to compress pretreated data. The recognition models of eight maize varieties were built based on biomimetic pattern recognition (BPR). The average correct recognition rate and average correct rejection rate of identification models built by two modes were calculated. The average recognition rate and rejection rate of diffuse reflectance method reached 94.50% and 96.71%, and those of transmittance method reached 98.5% and 98.00%, respectively. Both of them met the requirements of maize preliminary screening, and the recognition rate and rejection rate of transmittance method are higher than diffuse reflectance method by 4% and 1.3% respectively.

[Study of feature extraction methods for maize's near infrared spectra in biomimetic pattern recognition].

Near infrared spectrum is an important step in near infrared spectrum qualitative analysis, which influences the qualitative analysis results directly. Diffuse transmittance measurements mode was used to collect spectral data of eight maize varieties. PCA, ICA, PLS-DA and wavelet transformation were used to extract features of pretreated data. Finally, we used the test set data to test the recognition models of eight maize varieties which were built based on biomimetic pattern recognition (BPR). We draw a conclusion that PLS-DA can make models get higher average correct recognition rate than PCA, ICA and Wavelet transformation.

[Study on spectral measurement methods in identification of maize variety authenticity based on near infrared spectra of single kernels].

In order to establish the better maize variety identification models based on single kernel samples, the near-infrared spectral measurement methods were studied by comparing the direction of the maize seed's embryo, diffuse reflectance and transmission mode, devices of holding the sample according to their impacts on the performance of variety identification models. Partial least squares-discriminant analysis (PLSDA) was used to compress the pretreated spectral data into 9 variables, and then the identification models were built based on biomimetic pattern recognition (BPR). The results show that with the maize grain's embryo facing the light source the models can be made perform better than with embryo backing toward the light source, diffuse reflectance mode is better than transmission mode, and small sample pool performs better than the small aperture. The measurement method of acquiring the diffuse reflectance near infrared spectra of maize by small pool with the seed embryo facing the light source can make models have the best performance. The average correct identification rate of the models is 94.6%, and the average correct rejection rates for the varieties not belonging to the models reached 96.5%.

Determination of hydrogen selenide in workplace air with atomic fluorescence / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To determined hydrogen selenide in workplace air with atomic fluorescence.</p><p><b>METHOD</b>Hydrogen selenide were sampled with 0.1 mol/L sodium hydroxide solution in multi-hole absorbing tubes. The sampled absorbing solution were digested with (9+1) nitric acid/perchloric acid. The selenide in sample were reduced by potassium borohydride in 5.0% hydrochloride solution and determined with atomic fluorescence.</p><p><b>RESULTS</b>There was a good linearity (r=0.9999) over the concentration of 0-150 microg/L, The precision of low, middle and high concentration were 3.1%, 7.4% and 6.7%, respectively. The sample collection rate can reach 99%.</p><p><b>CONCLUSION</b>The method was accurate and sensitive to detect hydrogen selenide in workplace air.</p>

The improvement of determination method of carbon disulfide in workplace air with gas chromatography / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>Establishment of determination method of carbon disulfide in charcoal tube with low toxicity solvents desorption-gas chromatography.</p><p><b>METHODS</b>Four types of solvent with low toxicity are applied respectively as substitution of benzene to desorb the carbon disulfide in samples of charcoal tube. The signal strength and desorption efficiency of the detector are compared by using different solvents.</p><p><b>RESULTS</b>Chloroform has been considered as the best alternative solvent of benzene. Carbon disulfide has a good linearity (R = 0.9997) over the concentration of 0 ∼ 54.7 µg/ml, detection limit can reach 0.2 µg/ml. When the sampling volume is 3.0 L, the minimum detectable concentration is 0.07 mg/m(3).</p><p><b>CONCLUSION</b>With the use of chloroform, the health hazard to laboratory personnel and environment pollution as well as the costs of experiments are reduced.</p>

The optimization of 2-thiothiazolidine-4-carboxylic acid back extraction in urine and determination by HPLC / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>Establishment of determination method of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine with HPLC.</p><p><b>METHODS</b>A volume of 0.5 ml hydrochloric acid (2 mol/L) and 0.5 ml pure water was added into 1 ml urine, and then extracted by 4 ml of diethyl ether by shaking for 2 min. Remove the water phase in a tube with plug and extract again, mix the two extraction diethyl ether together, take 4 ml by adding 2 ml borax-monopotassium phosphate buffer and shaking for 2 min to extract, then take the water phase to detect. A C(18) column and UV detector were used for separating and detecting. The wavelength was 273 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 µl.</p><p><b>RESULTS</b>TTCA has a good linearity (r = 0.9995) over the concentration of1 1 ∼ 10 µg and the minimum detectable concentration of TTCA in urine was 0.1 µg/ml. The within-day precision (RSD) were 8.4%, 3.0% and 1.7%, the between-day precision (RSD) were 11%, 3.8%, 1.9%, respectively. The extraction recovery were between 80% ∼ 102%.</p><p><b>CONCLUSION</b>The method was accurate and sensitive to detect TTCA in urine.</p>

The rervising of biological exposure index for carbon disulfide exposuring / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the biological exposure index of carbon disulfide in China.</p><p><b>METHODS</b>High-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.</p><p><b>RESULTS</b>The 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.</p><p><b>CONCLUSION</b>The biological exposure index of CS(2) in China might be revised for 1.2 mg/g Cr.</p>