ObjectiveTo study the diagnosis of thyroid cancer concurrent with multiple thyroid nodules.Methods The clinical data of 23 patients of multiple thyroid nodules with thyroid cancer undergoing exploration from May 1988 to December 2000 were analyzed retrospectively.ResultsThe diagnosis of concurrent carcinoma was made preoperatively in 6 cases. 13 out of the 23 patients underwent second operation for the postoperative pathology being malignant. Thyroid cancer was identified concurrent with benign nodules in 20 cases. Conclusion Thyroid cancer when found on the background of multiple thyroid nodules is often coexistant with benign thyroid disease, hence the diagnosis is difficult to make clinically. Second operation is sometimes inevitable when the pathology identified a cancer in preoperatively diagnosed benign nodules.

The method of PBL (problem based learning) teaching in China is widely recognized. However, the characteristics of Vocational Medical Education limit its wider application. The paper discusses the mode which is suitable for our country by analyzing the major issues,improving methods of teaching and doing experiments.

Objective:To investigate the distribution and intensity of noise and ultraviolet radiation of welding posts in a refrigeration equipment manufacturing enterprise, in conjunction with the health status of welding workers, providing scientific evidence for the prevention and control of occupational diseases in this type of post.Methods:In May 2019, a cross-sectional survey method was used to select 576 welding workers in the pressure vessel workshop and the unit assembly workshop of a refrigeration complete equipment manufacturer from 2016 to 2018 as the research objects. The occupational hygiene survey and occupational hazard factor measurement were carried out in the workplace, and the measurement data and occupational health examination results were statistically analyzed.Results:The over standard rate of individual Lex in pressure vessel workshop was 82.2% (37/45) . Compared with the unit assembly workshop, the individual Lex of welding workers in pressure vessel workshop was higher than that in unit assembly workshop ( t=13.43, P= 0.00) ; the effective irradiance exceeding rate of welding workers in pressure vessel workshop and unit assembly workshop was 33.3% (4/12) and 25.0% (3/12) , The meacurement of ovradiation in the moskment the occupational exposure limit. The deaf rate and hearing loss rate in pressure vessel workshop were 1.5% (5/336) 20.5% (69/336) , respectively, significantly higher than that in umit assembly workshop ( P<0.05) . The detection rate of hearing loss of pressure vessel workshop workers increased year by year, and the difference was statistically significant (χ 2trend=22.42, P<0.01) ; compared with the unit assembly workshop from 2016 to 2018, the detection rates of lens opacity, corneal cloudiness and hearing loss of pressure vessel workshop workers were statistically significant (χ 2=9.45, 14.80, 55.99, P<0.01) . Conclusion:Welding workers exposed to noise and ultraviolet radiation are easy to be ignored. The enterprise management department should attach great importance to it and take comprehensive measures to protect the health of welding workers.

Objective:To investigate the distribution and intensity of noise and ultraviolet radiation of welding posts in a refrigeration equipment manufacturing enterprise, in conjunction with the health status of welding workers, providing scientific evidence for the prevention and control of occupational diseases in this type of post.Methods:In May 2019, a cross-sectional survey method was used to select 576 welding workers in the pressure vessel workshop and the unit assembly workshop of a refrigeration complete equipment manufacturer from 2016 to 2018 as the research objects. The occupational hygiene survey and occupational hazard factor measurement were carried out in the workplace, and the measurement data and occupational health examination results were statistically analyzed.Results:The over standard rate of individual Lex in pressure vessel workshop was 82.2% (37/45) . Compared with the unit assembly workshop, the individual Lex of welding workers in pressure vessel workshop was higher than that in unit assembly workshop ( t=13.43, P= 0.00) ; the effective irradiance exceeding rate of welding workers in pressure vessel workshop and unit assembly workshop was 33.3% (4/12) and 25.0% (3/12) , The meacurement of ovradiation in the moskment the occupational exposure limit. The deaf rate and hearing loss rate in pressure vessel workshop were 1.5% (5/336) 20.5% (69/336) , respectively, significantly higher than that in umit assembly workshop ( P<0.05) . The detection rate of hearing loss of pressure vessel workshop workers increased year by year, and the difference was statistically significant (χ 2trend=22.42, P<0.01) ; compared with the unit assembly workshop from 2016 to 2018, the detection rates of lens opacity, corneal cloudiness and hearing loss of pressure vessel workshop workers were statistically significant (χ 2=9.45, 14.80, 55.99, P<0.01) . Conclusion:Welding workers exposed to noise and ultraviolet radiation are easy to be ignored. The enterprise management department should attach great importance to it and take comprehensive measures to protect the health of welding workers.

OBJECTIVE: To formulate a limit of occupational benzoquinone in the air of workplace. METHODS: According to GBZ/T 210. 1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace,the relevant literatures on toxicology,epidemiology and foreign occupational exposure limit for benzoquinone were collected and analyzed. A benzoquinone production enterprise was selected as the research subject. Occupational hygiene investigation and occupational epidemiological investigation were carried out. The occupational exposure limit of benzoquinone in the air of workplace was assessed. RESULTS: The literature data analysis results showed that benzoquinone is a highly toxic substance,has strong stimulated effect on human respiratory tract,eyes and skin. The occupational exposure limit of benzoquinone in the workplace air in the United States of America,Germany and Australian is 0. 400 mg/m~3. In the benzoquinone production enterprise,the median of concentration-time weighted average of benzoquinone exposed workers( exposure group) was 0. 100 mg/m~3. The median of concentration-short term exposure limit in the workplace air was 0. 160 mg/m~3. There was no significant difference on the abnormal detection rate of conjunctivitis,dermatitis,and abnormal liver B type and abnormal kidney B type ultrasound between the exposure group and the control group( P > 0. 05). There was no significant difference on the serum liver function and renal function indexes between the two groups( P > 0. 05). The results of blood routine examination in the two groups were within the normal reference range. CONCLUSION: It is suggested that the permissible concentration-time weighted average of benzoquinone in the workplace air should be set at 0. 400 mg/m~3 in China.