[Performance of a recombinase - aided amplification assay for detection of Schistosoma japonicum infections in Oncomelania hupensis].

OBJECTIVE: To evaluate the efficiency of a recombinase-aided amplification (RAA) assay for the detection of Schistosoma japonicum infections in Oncomelania hupensis snails. METHODS: A group test was employed. Fifty Oncomelania snails were collected as a detection sample. The detection samples without infected snails were designated as negative specimens, while the detection samples that contained different numbers of infected snails were designated as positive specimens. A total of 10 negative specimens, 10 positive specimens containing 1 infected snail, 20 positive specimens containing 2 infected snails and 10 positive specimens containing 3 infected snails were assigned. Following random grouping, 40 specimens were subject to the florescent RAA assay using a blind method. The miradium shedding method served as a gold standard, and the sensitivity, specificity, Youden's index and coincidence rate of the florescent RAA assay were estimated. In addition, 20 samples consisted of 5 negative specimens and 15 positive specimens with 1, 2 and 3 infected snails respectively were grouped randomly. The same specimens were detected using the crushing method and fluorescent RAA assay with the blind method in a paired-design manner. Then, the test results were compared and analyzed. RESULTS: Florescent RAA assay detected 29 positives in the 30 specimens containing different numbers of infected snails, with a sensitivity of 96.67%, and 8 negatives in the 10 detection specimens without infected snails, with a specificity of 80.00%, showing a Youden's index of 0.77. The coincidence rate was 100% among 10 repeated assays for a detection specimen. In addition, there was no significant difference in the detection of infected snails between the florescent RAA assay and the crushing method (χ2 = 0, P > 0.05), and the actual coincidence rates of the florescent RAA assay and crushing method were 95.00% (19/20) and 90.00% (18/20) with the real results, respectively. CONCLUSION: Fluorescent RAA assay has a favorable efficiency for the detection of S. japonicum infections in Oncomelania snails, which shows a potential in screening of S. japonicum-infected Oncomelania snails.

[A case-control study on effect of occupational factor exposures on carotid atherosclerosis in steel workers].

Objective: To investigate the effect of occupational factor exposures on carotid atherosclerosis (CAS) in steel workers. Methods: A frequency matched case-control study was conducted by age and factory proportion. A total of 1 033 workers with carotid atherosclerosis diagnosed by ultrasonography examination from February to June 2017 were selected as case group, and 1 033 workers without carotid atherosclerosis indicated by physical examination at the same time were selected as control group. The basic information of the workers, such as diet pattern, lifestyle, serum biochemical index and occupation history, were collected. The effects of occupational hazards on carotid atherosclerosis were analyzed by univariate and multivariate logistic regression analyses. The combined effects of various occupational hazards on carotid atherosclerosis were evaluated by environmental risk score (ERS). Results: High temperature, noise, occupational stress and night shift days increased the risk of CAS. With the increase of cumulative high temperature and noise exposure, occupational stress and night shift days, the risk of CAS increased (trend text: χ(2)=37.53, P<0.01; χ(2)=16.98, P<0.01; χ(2)=13.93, P<0.01; χ(2)=5.59, P<0.05). After adjustment of covariates, compared with P(20) group, the risk of carotid artery in P(40), P(60), P(80) and P(100) groups were as follows: high temperature 1.61 (1.19-2.18), 1.69 (1.25-2.30), 1.84 (1.36-2.49), 2.43 (1.77-3.34); noise 1.70 (1.15-2.52), 1.68 (1.20-2.35), 1.80 (1.34-2.42), 2.23 (1.53-3.26); occupational stress 1.39 (1.04- 1.86), 1.41 (1.06-1.89), 1.45(1.09-1.95), 1.48 (1.10-1.98); night shift days 1.58 (1.08-2.33), 1.66 (1.12-2.47), 1.55 (1.04-2.31), 1.76 (1.17-2.64). The results of the environmental risk score showed that the risk of carotid atherosclerosis increased with the increase of ERS (ERS trend text χ(2)=51.61, P<0.01); RCS results showed that there was a linear relationship between ERS and CAS in steel workers(P<0.01). Linear dose-response relationship existed between ERS and CAS (nonlinear test P>0.05). Conclusions: High temperature, noise, occupational stress and night shift days were related to carotid atherosclerosis. Linear dose-response relationship existed between ERS and CAS in steel workers.

[Effect of occupational factors on pre-diabetes mellitus among iron and steel workers].

Objective: To investigate the prevalence of pre-diabetes mellitus (PDM) and the impact of occupation-related factors on PDM, among workers from a steel company in Tangshan city, Hebei province. Methods: Clustering sampling method was used to select a steel company and to carry out occupational health-related physical checkup programs for eligible workers who had working in this company for longer than one year. The study began in February and ended up in June, 2017. Workers who were with FPG level as ≤6.9 mmol/L, and free from diabetes, were selected as the subjects for this study. Questionnaires were used and physical examinations and FPG testing conducted. Results: The total number of subjects in this study was 4 173, of which 2 648 appeared as pre-diabetic, with the prevalence rate as 63.4%. Increase of the PDM prevalence was in parallel with the length of service, among the workers. The risk for the pre-diabetes in those who worked more than 8 hours per day was 1.696 times higher than those who worked less than or equal to 8 h/d (95%CI:1.517-1.937). Compared with those workers without exposures to heat, noise or carbon monoxides, the proportion of pre-diabetes appeared higher in workers exposed to heat, noise or CO with OR=1.782 (95%CI: 1.205-2.636), 1.815 (95%CI: 1.209-2.794) and 1.653 (95%CI: 1.158-2.361), respectively. Risks for those who were exposed to heat or noise were higher than those who were free from exposure to any occupational hazards (OR=2.098, 95%CI: 1.296-3.397). Prevalence rates of pre-diabetes in those who were exposed to heat, noise or CO, were higher than that those who were not. Conclusion: Working hours and exposures to heat, noise or CO appeared as influential factors on PDM.

Diffusively coupled bursters: effects of cell heterogeneity.

The interaction of a pair of weakly coupled biological bursters is examined.Bursting refers to oscillations in which an observable slowly alternates between phases of relative quiescence and rapid oscillatory behavior. The motivation for this work is to understand the role of electrical coupling in promoting the synchronization of bursting electrical activity (BEA) observed in the -cells of the islet of Langerhans, which secrete insulin in response to glucose. By studying the coupled fast subsystem of a model of BEA, we focus on the interaction that occurs during the rapid oscillatory phase. Coupling is weak, diffusive and non-scalar. In addition,non-identical oscillators are permitted. Using perturbation methods with the assumption that the uncoupled oscillators are near a Hopf bifurcation, a reduced system of equations is obtained. A detailed bifurcation study of this reduced system reveals a variety of patterns but suggests that asymmetrically phase-locked solutions are the most typical. Finally, the results are applied to the unreduced full bursting system and used to predict the burst pattern for a pair of cells with a given coupling strength and degree of heterogeneity.

Raman, fluorescence, and time-resolved light scattering as optical diagnostic techniques to separate diseased and normal biomedical media.

Studies of Raman scattering, fluorescence and time-resolved light scattering were conducted on cancer and normal biomedical media. Fourier transform Raman spectroscopic measurements were performed on human normal, benign and cancerous tissues from gynecological (GYN) tracts. A comparison of the intensity differences between various Raman modes as well as the number of Raman lines, enables one to distinguish normal GYN tissues from diseased tissues. Fluorescence spectroscopic measurements on human breast tissues show that the ratio of fluorescence intensity at 340 nm to that at 440 nm can be used to distinguish between cancerous and non-cancerous tissues. Separate studies on normal and cancerous breast cell lines show spectral differences. The measurements of back-scattered ultrafast laser pulses from human breast tissues show differences in the scattered pulse profiles for different tissues. These studies show that various optical techniques have the potential to be used in medical diagnostic applications.