Objective To quantitatively assess the association of short-term exposure to polycyclic aromatic hydrocarbons (PAHs) in ambient fine particulate matter (PM2.5) with residents mortality. Methods A time-stratified case-crossover study was conducted from 2020 to 2022 among 10606 non-accidental residents by using the Guangzhou Cause of Death Surveillance System in Conghua District, Guangzhou. Exposure levels of PAHs in PM_2.5 and meteorological data during the study period were obtained from the Center for Disease Control and Prevention in Conghua District and the China Meteorological Administration Land Data Assimilation System (CLDAS-V2.0), respectively. Conditional Poisson regression model was used to estimate the exposure-response association between PAHs and the mortality risk. Results Fluoranthene, chrysene, benzo[k]fluoranthene, benzo[a]pyrene, and indeno[1,2,3-cd]pyrene were significantly associated with an increased risk of mortality. For every one interquartile range increase in exposure levels, the non-accidental mortality risks increased by 8.33% (95% CI: 1.80%, 15.27%), 4.67% (95% CI: 1.86%, 7.57%), 6.07% (95% CI: 2.08%, 10.21%), 4.62% (95% CI: 1.85%, 7.47%), and 4.70% (95% CI: 0.53%, 9.03%), respectively. The estimated non accidental deaths attributable to exposure to fluoranthene, chrysene, benzo[k]fluorine, benzo[a]pyrene and indine[1,2,3-cd]pyrene were 5.91%, 6.08%, 6.51%, 6.46%, and 4.21%, respectively. Conclusions Short-term exposure to PAHs in PM_2.5, including fluoranthene, chrysene, benzo[k]fluoranthene, benzo[a]pyrene and indine[1,2,3-cd]pyrene, was significantly associated with an increased risk of mortality among residents.

Objective:To investigate the application effect of case-based learning (CBL) based on the clinical case library of stomatology in standardized residency training for comprehensive stomatology.Methods:A total of 52 residents in Department of Stomatology, Chongqing Medical University, were given CBL teaching based on the clinical case library of comprehensive stomatology, and a questionnaire survey was performed to evaluate the teaching effect. Theoretical and skill assessments were performed before and after CBL teaching, and a comparative analysis was performed. SPSS 19.0 software was used for the t-test. Results:The questionnaire survey showed that CBL teaching based on the clinical case library of stomatology effectively improved the ability of independent learning [92.31% (48/52)], the interest in learning [88.46% (46/52)], and the ability for case diagnosis and the accuracy of investigation and judgment [94.23% (49/52)]. This method helped with the mastery and understanding of the theoretical knowledge in stomatology [96.15% (50/52)] and improved the abilities for expression and communication [84.62% (44/52)] and the ability to find and solve problems [94.23% (49/52)]. It also helped to stimulate the interest in scientific research and teaching [82.69% (43/52)] and create an active classroom atmosphere [82.69% (43/52)]. Among these residents, 94.23% (49/52) liked CBL teaching, and 88.64% (46/52) thought the setting of the case library was reasonable. After the application of CBL teaching, there were significant increases in theoretical score [from (66.74±4.25) points to (81.44±7.16) points] and skill examination score [from (64.00±3.14) points to (81.96±7.50) points].Conclusions:CBL teaching based on the case library of stomatology has a good teaching effect in the standardized residency training for comprehensive stomatology and can not only improve the theoretical and skill assessments of residents, but also improve their learning interest and clinical thinking ability.

Objective:Cardiac arrest (CA) represents a significant public health challenge, posing a substantial threat to individual health and survival. To enhance the survival rates of patients experiencing out-of-hospital cardiac arrest (OHCA), Baoan District in Shenzhen City has undertaken exploratory initiatives and practical interventions, yielding promising preliminary outcomes.Methods:1.Innovate emergency medical services by developing a "four-circle integration" system that connects to the hospital. This system encompasses the social emergency medical system, the out-of-hospital emergency medical system, the in-hospital emergency medical service system, and the intensive care treatment system. 2.Develop a comprehensive model for the construction of a social emergency medical training system, characterized by party leadership, government oversight, departmental coordination, professional guidance, technological support, and community involvement, termed the "Baonan Model." Additionally, establish evaluation criteria to assess the effectiveness of the social emergency medical training system in Baonan District; 3. Develop a cardiac arrest registration system and a social emergency medical training management system for Baonan District; 4. Enhance the proficiency in treatment techniques and the quality of cardiopulmonary resuscitation among emergency medical professionals; 5. Strengthen and advance the development of a "five-minute social rescue network" to address the critical "emergency window period." .Result:In Baonan District, 9.18% of the public is trained in emergency medical skills. The bystander CPR rate for OHCA is 26.11%, AED use is at 4.78%, the 30-day survival rate is 6.31%, and the discharge survival rate is 4.44%.Conclusion:The implementation of the aforementioned measures can substantially enhance the survival rate of patients experiencing OHCA at the time of discharge.

Objective:To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey.Methods:From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis.Results:The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant ( P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index ( P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels ( P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables ( P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061–1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039–1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260–2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127–1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168–1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608–0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495–0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534–0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428–0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674–0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944–1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783–1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion:The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

Objective:To determine the prevalence and risk factors of constipation in Hangzhou urban areas by analyzing data from a recent epidemiological survey.Methods:From August 2022 to June 2023, a cross-sectional survey was conducted on 43 communities on eight streets in suburbs of Hangzhou, including Wangjiang, Sijiqing, Puyan, Changhe, Ziyang, Xiaoshanchengxiang, Zhuantang, and Banshan. Written questionnaires were filled out face to face by community doctors. The prevalence of constipation was investigated using a combination of the Bristol stool typing method and the Rome IV criteria. The risk factors for constipation were analyzed using multivariate logistic regression analysis.Results:The study cohort comprised 10,479 participants, 5551 of whom were male (53.0%) and 4928 female (47.0%). The overall prevalence of constipation was 10.6% (1107/10,479). The prevalence was 11.0% (613/5551) for male and 10.0% (494/4928) for female participants; this difference is not statistically significant ( P>0.05).There were no significant differences in the prevalence of constipation between different categories of body mass index ( P>0.05). The prevalence of constipation was highest in individuals aged 70 years and above, accounting for 15.4% (264/1717) of all cases. There were significant differences in the prevalence of constipation between different occupations, marital statuses, and educational levels ( P<0.001). Patients with hypertension or diabetes mellitus had a higher prevalence of constipation than those without these conditions, those who had been taking long-term medication had a higher prevalence of constipation than those who did not, parents of children with constipation had a higher prevalence of constipation than those with children who did not have constipation, and there were other significant differences in various variables ( P<0.001). Multivariate logistic regression analysis of modifiable factors revealed that eating less fruit (OR=1.284, 95%CI: 1.061–1.553, P=0.010), liking spicy and salty food (OR=1.234, 95%CI: 1.039–1.466, P=0.016), sleeping for too long (OR=1.644, 95%CI: 1.260–2.144, P<0.001), irregular sleep patterns (OR=1.370, 95%CI: 1.127–1.665, P=0.002) and minimal exercise (OR=1.388, 95% CI: 1.168–1.649, P<0.001) were all risk factors for constipation; whereas mix diets (OR=0.709,95%CI:0.608–0.826, P<0.001), meat diets (OR=0.604,95%CI: 0.495–0.736, P<0.001), moderate alcohol consumption (OR=0.659, 95% CI: 0.534–0.812, P<0.001), less or no drinking (OR=0.523, 95% CI: 0.428–0.638, P<0.001), and non-smoking (OR=0.819, 95%CI:0.674–0.995, P<0.001) protected against constipation. We found no association between dietary preferences and the risk of constipation (refined grains: OR=1.147, 95%CI:0.944–1.393, P=0.167; no specific preference: OR=0.935, 95%CI:0.783–1.117, P=0.459). The rate of agreement between self-evaluation of constipation by the respondents and objective criteria was higher for negatives (95.8%) than for positives (38.0%). Conclusion:The prevalence of constipation is relatively high in the urban population of Hangzhou. A good lifestyle and diet can significantly reduce its incidence. There should be more emphasis on preventive education, promotion of prevention of constipation, and advocacy for a healthy lifestyle.

Objective:To explore the application effect of task-driven teaching method combined with Sandwich teaching method in the standardized residency training of oral general practitioners.Methods:A total of 40 trainees of the standardized residency training of the Teaching and Research Section of Oral General Practice in Chongqing Medical University were randomly divided into experimental group and control group. The experimental group ( n=20) adopted task-driven teaching method combined Sandwich teaching method, and the control group ( n=20) adopted the traditional teaching method. The theory assessment, skills assessment and the teaching satisfaction questionnaire survey were conducted to evaluate the teaching effects. SPSS 19.0 software was used for t-test. Results:The theoretical test scores of the experimental group were significantly higher than those of the control group [(85.85±25.61) points vs. (74.35±10.53) points], and the difference between the two groups was statistically significant ( t=8.56, P < 0.001). The skill test scores of the experimental group were significantly higher than those of the control group [(86.50±18.20) points vs. (73.40±16.57) points], and the difference was statistically significant ( t=9.94, P<0.001). The results of the teaching satisfaction questionnaire showed that the experimental group had significantly higher scores than control group in such seven aspects as improving students autonomous learning ability and interest in learning, teamwork and interpersonal relationships, diagnostic ability of cases and the accuracy, doctor-patient expression and communication ability, ability to find and solve problems, stimulating interest in scientific research and teaching, mastering and understanding the oral theoretical knowledge and so on ( t=10.40, 10.40, 9.95, 5.43, 7.66, 8.08, 9.60, respectively, all P<0.001). Task-driven teaching combined with Sandwich teaching method stimulated the learning interest of trainees and improved their comprehensive ability. Conclusion:Task-driven teaching combined with Sandwich teaching method has greatly improved the teaching effect of standardized residency training of oral general practitioners.

Objective:To share the implementation experience of hierarchical first aid training scheme for elementary and middle school students in Baoan District of Shenzhen City and evaluate its effect of training. Methods:During August 2018 and August 2019, elementary and middle schools students who participated in the first aid training held by emergency rescue training center of Baoan District were enrolled. Baseline information including the number of students, the number of attending tutors, the number of cardiopulmonary resuscitation (CPR) training models, automated external defibrillator (AED) models were recorded. According to hierarchical levels of three age, students received different courses with content from simple to hard: the course of elementary school students was consisting of dialing 120, smart animation on how to identify accidental damage, demonstration of AED and Hemlick techniques, CPR practise (40 minutes). The course of junior high school students was consisted of how to dial 120, how to identify accidental damage and simple disposal, application of CPR and AED, practice CPR and AED and Hemlick techniques (90 minutes). The course of high school students was consisted of how to dial 120, identify accidental damage and right disposal, identification of out-of-hospital cardiac arrest, the key-point of CPR and AED, practice CPR and AED, Hemlick techniques and hemostatic bandage (120 minutes). At the end of course, elementary school students were voluntary for skill assessment; junior high school students only were compulsory for skill assessment in small classes but not required in large classes, just for demonstration; additionally, the whole high school students were compulsory for skill assessment. The characteristics of first aid training students at different levels were collected in order to compare the differences on the usage of CPR training model and AED training model, the distribution of emergency resource, the ratio for passing examination.Results:A total of 12 896 students and 2 086 training instructors took parted in 200 lists of first aid training courses, 8 557 CPR models and 8 493 AED models were used. On average, there are 65.27±5.61 students in each session, and 10.52±10.43 training instructors. There are 43.09±19.06 CPR training models and 42.77±18.61 AED training models. The mean ratio of student to tutor was 6.07±1.47, student to CPR model was 1.54±1.02, and student to AED model was 1.54±1.03. In the end of course, 10 494 students participated in the examination with the participation rate of 81.37%; 10 114 students passed the examination with the passing rate of 96.38%. Hierarchical analysis showed: compare to elementary school students, the average number of junior high school students in every training session significantly increased (cases: 69.94±8.77 vs. 58.69±6.12, P < 0.05), but the average number of high school students in every training session significantly decreased (cases: 57.35±5.79 vs. 58.69±6.12, P < 0.05). The proportion of instructors in junior high school students' training significantly reduced (5.94±1.39 vs. 6.48±2.02, P < 0.05). The examination ratio of junior high school students and high school students was increased significantly [81.07% (6 667/8 224), 100% (2 313/2 313) vs. 64.18% (1 514/2 359), both P < 0.05], but the ratio of passing the examination was significantly reduced [95.47% (6 365/6 667), 96.88% (2 241/2 313) vs. 99.60%(1 508/1 514), both P < 0.01]. This might be related to the low difficulty of elementary school students' assessment and the low proportion of compulsory examination. Conclusions:Hierarchical scheme is feasible for first aid training in elementary and middle school students, the content of course should be desighed from easy to hard. Synchronously, sufficient training instructors and training models should be equipped to ensure the quality.

Objective: To investigate the manufacturing procedures of personalized miniscrew-assisted rapid palatal expanders (pMARPE) using digital technologies and to evaluate the effect of the expanders when expanding the midpalatal suture of an adult. Methods: Digital technologies were used to make pMARPE, which was used to treat a 21-year-old woman with maxillary transverse deficiency (MTD). The relevant literature on MARPE was reviewed. Results: PMARPE could be manufactured using intraoral digital scanning, computer-aided design and computer-aided manufacturing(CAD/CAM ), and 3D printing technologies. After expansion, the width of the anterior midpalatal suture, posterior midpalatal suture and maxillary skeletal width increased by 3.9 mm, 3.2 mm and 4.7 mm, respectively. There was no significant change in the inclination of maxillary first molars, and the height of alveolar ridge decreased slightly. It could be seen that using digital technologies to manufacture personalized expanders was possible for MARPE , and the initial stability of miniscrews played an important role in the expansion success rate, the increase of molar inclination is composed of many parts, and the decrease of alveolar ridge height may be overestimated due to the measurement method, as shown by a literature review. Conclusion The midpalatal suture of an adult patient with MTD could be expanded by pMARPE. However, the effect of this expander on the inclination of the first molar and alveolar bone height needs to be further studied with a larger sample size.

Transverse maxillary deficiency is a common malocclusion in the clinic. Palatal expansion techniques are commonly used in the treatment of maxillary transverse deficiency. Traditional palatal expansion techniques have good effects on the treatment of children and adolescents whose palatal suture has not yet closed, but the effects on adult patients are unsatisfied. New palatal expansion techniques, such as miniscrew-assisted rapid palatal expansion and surgical-assisted maxillary expansion, have increased the age-related indications for palatal expansion, and their bone expansion effect has been strengthened. With the development of CAD/CAM technology and 3D printing technology, techniques such as Invisalign and personalized appliances have been developed and have promising application prospects. To provide references for the clinical treatment of maxillary transverse deficiency, palatal expansion techniques are reviewed from the following aspects: mechanism and indications, expansion pattern, traditional and new palatal expansion appliances, stability and retention of palatal expansion, outlook of future expanders, etc.

Objective:To analyze the component ratio of the social emergency training instructors in Baoan District, Shenzhen;Methods:During January 2018 to January 2019,participants, candidate to be social emergency training instructors in Baoan district, Shenzhen, were enrolled in our analysis. they needed orderly pass primary selection and intensive selection to be formal social emergency training instructors. Personal data from candidates including hospital, serving department, degree and professional types were collected. According to serving departments, candidates from pre-hospital emergency, emergency ward and critical care unite is belong to the emergency group and other s who is not from above departments belong to the non-emergency group.Results:Total of 1 270 candidates took part in 7 primary classes and 27 intensive selection until 1131 of them received the formal certifications. 440(38.90%) instructors from emergency group and 691(61.10%) instructors belong to non-emergency group. At category level of hospital, 213 (18.83%) is from three grade, 525 (46.42%) is from two grade, 254 (22.46%) is from specialized hospitals, and 139 (12.29%) is from community health centers. In non-emergency group, ratio of serving departments are consists of: 15.77% from internal medicine, 10.14% from chirurgery, 8.11% from pediatrics, 7.96% from obstetrics and gynecology, 2.62% cases from otorhinolaryngology, 24.29% from medical assistants, 20.11% from community health center and 11.00% from administrative officer. Nurses (64.13%) is the majority professional types of social emergency training instructors. In terms of degree, bachelor mainly occupied at 71.02%. Primary (53.18%) and attending (30.47%) account for majority of position ranks.Conclusions:Our team of social emergency training instructors,mainly from local medical staffers, has a great educational background and competitive team; Among them, emergency team is crucial to provoke other medical staffs from different departments to participate in career at social emergency training.