Objective　To establish gas chromatographic method for determination of air methylcyclohexane in workplace. Method　This method was based on “Standardization of methods for determination of toxic substances in workplace air". Results　Breakthrough capacities of 100 mg of active carbon was >15.05 mg.Absorption efficiencies were 99.64%～100% when methylcyclohexane concentrations were 21.7～127.0 mg/m3.The sample could be stored in the active carbon tube at least for 8 days. Precision(RSD) was 4.4%～8.4%.Desorption efficiencies were 91.8%～96.6%,the lowest detection limit was 0.13 mg/m3.Other volatilizable organic solvents,e.g.,benzene,n-heptane,n-hexane,toluene were not interferences. Conclusion　This method meets the requirement of "Standardization of methods for determination of toxic substances in workplace air". It is suitable for determination of methylcyclohexane in workplace air.

Objective　To establish gas chromatographic method for determination of air methylcyclohexane in workplace. Method　This method was based on “Standardization of methods for determination of toxic substances in workplace air". Results　Breakthrough capacities of 100 mg of active carbon was >15.05 mg.Absorption efficiencies were 99.64%～100% when methylcyclohexane concentrations were 21.7～127.0 mg/m3.The sample could be stored in the active carbon tube at least for 8 days. Precision(RSD) was 4.4%～8.4%.Desorption efficiencies were 91.8%～96.6%,the lowest detection limit was 0.13 mg/m3.Other volatilizable organic solvents,e.g.,benzene,n-heptane,n-hexane,toluene were not interferences. Conclusion　This method meets the requirement of "Standardization of methods for determination of toxic substances in workplace air". It is suitable for determination of methylcyclohexane in workplace air.

OBJECTIVETo explore the characteristics in CFHR1 concentration and the frequency of CFHR1 gene polymorphisms of patients with type 2 diabetes mellitus (T2DM) based on the high level of complement factor H (CFH) expression among such patients and the similarity between CFHR1 and CFH in terms of sequence and functions.

METHODSFifty T2DM patients and 30 healthy controls were selected. The plasma samples were separated by pI with OFFGEL electrophoresis following solution digestion. Further separation and identification were carried out on a Nano HPLC-Chip-MS/MS system. Differentially expressed proteins were identified by comparison. Enzyme-linked immunosorbent assay (ELISA) was used to validate the result. Genomic DNA of the two groups was extracted. Polymerase chain reaction and sequencing were used to determine the single nucleotide polymorphisms in the 6 exons of the CFHR1 gene.

RESULTSThe CFHR1 level in plasma of T2DM patients were significantly higher than that of the healthy controls (P=2.78× 10). A significant difference in allelic frequencies of rs12406079 of the fifth exon of the CFHR1 gene was found between the two groups (χ=5.692, P=0.017).

CONCLUSIONThe concentration of CFHR1 and frequencies of CFHR1 gene polymorphisms among patients with T2DM differ significantly from healthy subjects. Polymorphisms of the CFHR1 gene are associated with T2DM.

Complement C3b Inactivator Proteins ; genetics ; metabolism ; Diabetes Mellitus, Type 2 ; genetics ; metabolism ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide

OBJECTIVEThis study aims to describe the distribution of 24 elements in urine of Shenzhen residents.

METHODSAccording to the principle of equal probability of selection method, in March 2011 to July, total 11 communities were chosen as the basic sampling unit in Shenzhen, with 1 to 2 communities in each of the municipal district. Then 75 families from each sampling unit were selected using systematic sampling method. In total, 2 200 subjects were chosen. 10-20 ml morning middle stream urine was collected, and then detected the concentration of Li, Be, Sr, Cd, Cs, Ta, Pb, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Sn, Sb, Te, As, Se, Ru, Na, Mg, K, and analysed the discrepancies between gender and among age groups.

RESULTSIn those 24 elements, the concentration of Na was highest, the medians( 5th percentile (P 5), 95th percentile (P 95)) were 2 845.78 (920.29, 5 974.53) mg/L; Be was lowest, the result was 0.10(0.01, 0.58) µg/L. Except macroelements of Na (2 921.97 (985.14, 6 201.51) mg/L), Mg (48.20(8.23, 132.41) mg/L), K (2 323.20(683.98, 5 657.47) mg/L), the content of Rb was highest, 3.31(9.82, 7.83) mg/L, followed by Zn, 454.54(113.90, 1 320.00) µg/L, the content of V, Cr, Mn, Se, Tl was pretty low, the median of those elements all less than 1.00 µg/L. Statistically significant differences were found between genders and among age groups in Pb, Fe, Se (gender: Z values were 4.51, 2.53, 4.00, all P values were <0.05; age groups: H values were 55.67, 129.42, 18.46, all P values were <0.05). The medians(P5, P95) were 2.04 (0.57, 5.31), 202.88 (48.66, 564.90), 49.68 (14.34, 150.91) µg/L. The values of male were 2.22 (0.71, 5.33), 212 (47.50, 567.29), 53.42 (16.20, 160.63) µg/L. And the results of female were 1.95 (0.51, 5.24), 193.69 (49.52, 562.31), 46.62 (12.65, 142.80) µg/L; the values of less than 17 years old subjects were 1.66 (0.38, 3.77), 106.13 (26.69, 459.81), 51.86 (15.86, 169.71) µg/L; the results were 1.96 (0.52, 5.08), 209.83(52.87, 577.81), 54.14 (15.14, 144.11) µg/L in the group of 18 to 40 years old; in the 41 to 65 years old group, the values were 2.29 (0.78, 5.85), 228.15 (67.74, 615.16), 46.62 (13.95, 143.57) µg/L, the results were 2.19 (0.65, 5.69), 195.92(55.17, 490.24), 43.16 (12.42, 155.36) µg/L in 66 years old and more group.

CONCLUSIONAmong these 24 elements in urine of Shenzhen residents, the Na concentration was highest, while Be was lowest. Elements (Pb, Fe, Se) differed with the condition of gender and age groups. So we should take all these factors into account to establish their reference values.

Adolescent ; Adult ; Aged ; China ; epidemiology ; Cross-Sectional Studies ; Female ; Humans ; Male ; Middle Aged ; Trace Elements ; urine ; Young Adult

Objective:To evaluate the diagnostic accuracy of the convolutional neural network（CNN） in diagnosing nasopharyngeal carcinoma using endoscopic narrowband imaging. Methods:A total of 834 cases with nasopharyngeal lesions were collected from the People's Hospital of Guangxi Zhuang Autonomous Region between 2014 and 2016. We trained the DenseNet201 model to classify the endoscopic images, evaluated its performance using the test dataset, and compared the results with those of two independent endoscopic experts. Results:The area under the ROC curve of the CNN in diagnosing nasopharyngeal carcinoma was 0.98. The sensitivity and specificity of the CNN were 91.90% and 94.69%, respectively. The sensitivity of the two expert-based assessment was 92.08% and 91.06%, respectively, and the specificity was 95.58% and 92.79%, respectively. There was no significant difference between the diagnostic accuracy of CNN and the expert-based assessment （P=0.282, P=0.085）. Moreover, there was no significant difference in the accuracy in discriminating early-stage and late-stage nasopharyngeal carcinoma（P=0.382）. The CNN model could rapidly distinguish nasopharyngeal carcinoma from benign lesions, with an image recognition time of 0.1 s/piece. Conclusion:The CNN model can quickly distinguish nasopharyngeal carcinoma from benign nasopharyngeal lesions, which can aid endoscopists in diagnosing nasopharyngeal lesions and reduce the rate of nasopharyngeal biopsy.
Humans ; Nasopharyngeal Carcinoma ; Narrow Band Imaging ; China ; Neural Networks, Computer ; Nasopharyngeal Neoplasms/diagnostic imaging*