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In environmental epidemiological research, extensive non-random environmental exposures and complex confounding biases pose significant challenges when attempting causal inference. In recent years, the introduction of causal inference methods into observational studies has provided a broader range of statistical tools for causal inference research in environmental epidemiology. The instrumental variable (IV) approach, as a causal inference technique for effectively controlling unmeasured confounding factors, has gradually found application in the field of environmental epidemiological research. This article reviewed the basic principles of IV and summarized the current research progress and limitations of applying IV for causal inference in environmental epidemiology. IV application in the field of environmental epidemiology is still in the initial stage. Rational use of IV and effective integration with other causal inference methods will become the focus of the development of causal inference in environmental epidemiology. The aim of this paper is to provide a methodological reference and basis for future studies involving causal inference to target population health effects of environmental exposures in China.
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Objective:To investigate the factors related to recurrent laryngeal nerve invasion in papillary thyroid carcinoma (PTC) with posterior capsular involvment.Methods:The data of 186 PTC patients admitted and operated from Jun 2017 to Jun 2022 were retrospectively analyzed. The invasion of recurrent laryngeal nerve was evaluated on its relation to gender, age, tumor size, Hashimoto's thyroiditis, lymph node metastasis in central region, BRAFV600E gene mutation especially PTC posterior capsular involvement.Results:The recurrent laryngeal nerve was invaded in 30 out of 186 patients. Univariate analysis showed that recurrent laryngeal nerve invasion was related to tumor size, Hashimoto's thyroiditis and cervical lymph node metastasis( χ2=6.964,4.814,6.078, P<0.05). Multivariate regression analysis showed that tumor size and lymph node metastasis in cervical region were independent risk factors for recurrent laryngeal nerve invasion(β=1.020,1.622, P<0.05). Hashimoto's thyroiditis was a protective factor for recurrent laryngeal nerve invasion (β=-1.881, P<0.05). Conclusions:When papillary thyroid carcinoma invaded the capsule, the risk of recurrent laryngeal nerve invasion was higher with larger tumor size and cervical lymph node metastasis, while Hashimoto's thyroiditis was a protective factor for the risk of recurrent nerve invasion.
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Objective To test and evaluate the protection and quality control status of some radiodiagnostic equipment in Gansu Province, China, and to strengthen the quality control and protection of radiodiagnostic equipment in hospitals. Methods A total of 72 medical institutions involving 203 sets of radiodiagnostic equipment and workplaces were selected to carry out the quality control and protection test according to relevant national standards. Results The qualified rate for the quality control test of the 203 sets of radiodiagnostic equipment was 92.1%, and that of the workplaces was 100%. Conclusion The results basically reflect the quality control and protection status of radiodiagnostic equipment in Gansu Province, indicating that regular inspection and timely debugging is very important.
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Objective To master and analyze the current situation of the monitoring technical ability of the radiation occupational hazards in the grass-roots CDCs in our province, and to provide relevant scientific basis for the modernization of the occupational health technical support system of the radiation occupational hazards in our province. Methods By means of questionnaire, we investigated, summarized and analyzed the status of the department setting, personnel and equipment of the technical service institutions for monitoring radiation occupational hazards in grassroots CDCs in our province. Results In terms of department setting, the setting rate of city and state level is 40.0%, and that of county and district level is 12.8%. In terms of human resources, the average number of people in each institution is 2.6, of which 61.1% are part-time employees and 38.9% are full-time employees. The average number of employees in each institution at county and district level is 1.1, of which 95.7% are part-time employees and 4.3% are full-time employees. The educational background distribution of municipal and county-level institutions were mainly undergraduate, accounting for 80.5% and 50.0% respectively. The educational background of staff in municipal and state level institutions was mainly occupational health, accounting for 58.3%, while the education background of staff in county and district level institutions was mainly other disciplines of medical and health, accounting for 64.1%. Conclusion Therefore, health administrative departments at all levels should support and guide CDCs at all levels to speed up the system layout and basic capacity-building according to the construction standards of technical support system for occupational disease prevention and control.
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<p><b>OBJECTIVE</b>To report on prenatal diagnosis and follow up of two patients with paternal uniparental disomy of chromosome 6 (pUPD6).</p><p><b>METHODS</b>Fetal cells were subjected to in situ culturing and G-banded chromosomal analysis. DNA samples of the fetuses and their parents were also analyzed with single nucleotide polymorphism microarray (SNP array).</p><p><b>RESULTS</b>Both fetuses had a normal male karyotype. SNP array analysis showed both have carried pUPD6.</p><p><b>CONCLUSION</b>pUPD6 can lead to transient neonatal diabetes mellitus type 1. Homozygous status of recessive mutations, disorder of gene imprinting, and its influence on placental function are the main factors to be considered during prenatal diagnosis and genetic counseling for pUPD6.</p>
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Objective To develop a new type of respiratory inductive plethysmograph to achieve high signal-noise rate(SNR)and low system power cost,and also to eliminate the cross-talk between chest and abdominal band sensors.Method Either of the two bands was powered by a very high power oscillator in a very short time,and these two bands were switched on in turn.The sensor structure of the respiratory inductive plethysmograph was modified so that these two bands could be embeded in a shirt conveniently.Result With these new designs,the cross-talk between these two bands was greatly eliminated and high SNR and low system power cost were achieved.This new wearable respiration monitoring system is easy to use,and can be used for long time and ambulatory monitoring.Conclusion This new system meets the design requirement with excellent performance.With this new wearable respiration monitoring system,non-invasive measurement of ventilation and non-intrusive detection of sleep apnea event can be achieved.
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Objective To introduce the structure and operating principle of a laser optometer for dark focus(DF). Methods Infrared and vernier means were used in the examination of dark focus. The stability, relationship between dark focus and refractive error were studied. Results The laser optometer was proved to be a reliable instrument with fine stability and good repeatability. Conclusion The laser optometer for dark focus can be used for further study relating to the aviation vision.