ABSTRACT:Objective To analyze the stress changes of tooth tissues in the medial-occlusal (Class Ⅱ)cavity restored with different kinds of inlay materials by the three-dimensional (3-D)finite element.Methods The inlay restored 3-D finite element model of medial-occlusal (Class Ⅱ)cavity was established by CBCT scanning method and reverse engineering software Mimics,Geomagic Studio,Pro/E5.0 software,and finite element analysis software. The Von-mises stress and change tendency of tooth tissues and four different kinds of inlay materials were compared after taking vertical loading and tongue 45°to loading.Results There were different stress levels of tooth tissues among different inlays of medial-occlusal (MO)Class Ⅱ cavity.The stress level of the cobalt chromium alloy inlay was the largest,the stress level of the gold alloy inlay was lower,and the stress level of the composite inlay was the lowest.Dental tissues stress distribution was similar for the four different restorative materials,and focused on hole bottom of dentin near the pulp in dentin.Conclusion Compared with ceramics,gold alloy and cobalt chromium inlay restoration,restoration with composite resin inlay can reduce the organization stress of the remaining tooth in the medial-occlusal (Class Ⅱ)cavity type.

Objective:To analyse the stress distribution of the tooth and inlay with the restoration of resin,porcelain,gold alloy,co-balt chromium materials respectively.Methods:3-D finite element models of mandibular first molar with meiso-occlusal (class II) cavity and different inlays were established.Von-mises stress distribution on the tooth and inlay with vertical load and lingual load at 45°were analyzed.Results:After restoration peak stress of high elastic module materials and dental inlays was higher than that of the low elastic module material inlays,however,the restorations of the different elastic module materials had the similar stress distribution trend.The stress under of lateral load(lingual at 45°)to the teeth inlays was significantly higher than that under vertical load.Peak stress concentration of tooth was on the bottom of the cavity near the pulp chamber dentin;inlay peak stress distribution is mainly in its corresponding to the gingival wall.In the tooth tissues stress level of the contact surface of inlay restoration,the strength was as the fol-lowing:Composite resin inlay >ceramics inlay >the gold alloy ceramics inlay >cobalt chromium alloy inlay.The stress level of the inlay of the four kinds of inlay restoration materials was just opponent with the tooth tissues.Conclusion:Gingival wall is the weakest part of meiso-occlusal(class II)cavity inlay restoration,while near the pulp chamber at the bottom of the cavity is the weakest part of the tooth.Among the 4 materials Under the same load condition,composite resin inlay restoration has minimal tooth stress and uniform stress distribution,and can reduce the posibility of odontoschism and microleakage.

OBJECTIVE:To understand the current situation and problems of the human resources of herbalists in Chongqing, and to provide reference for the relevant departments in formulating development plan for herbalists and promoting the healthy and sustainable development of Chinese medicine industry. METHODS:Chongqing municipal health and family planning commission is-sued the questionnaires to investigate the post distribution,educational background,job title and advanced study of medicine staff in Chongqing medical institutions. RESULTS:Questionnaires were gathered and reported by county health bureaus with effective re-covery rate of 100%. There were totally 19 713 Chinese medicine practitioners in Chongqing,including 1 739 herbalists,account-ing for 8.8%. Only 1.7%of the herbalists were graduate degrees,and the proportion of highly educated herbalists was low. The pri-mary professional position of the herbalists accounted only 59.5% and senior professional position was only 4.7%,the professional titles of herbalists were generally on the low side. The proportion of further education for herbalists was only 3.2%. There were sig-nificant differences in the ages,working time,highest education,professional positions and post properties and further studies among different economic areas(P<0.05). Herbalists of one-hour economic circle had higher educational level and higher profes-sional position than other two areas. CONCLUSIONS:Chongqing is lack of herbalists,and lack of the senior professional posi-tions,their education level is low and further education rate is low. In order to promote the development of Chinese medicine,it is necessary to strengthen the training and introduction of outstanding and young talents,strengthen the continuing education and regu-lar standardized training,improve the salary and welfare treatment for authorized strength and positions and balance the training for herbalists in different economic areas.

Objective:To analyze of the transmission characteristics of a cluster of COVID-19 cases in Chongqing and evaluate the infectivity of COVID-19 in the incubation period.Methods:A retrospective survey was conducted by using unified questionnaire through field and telephone interviews among 129 close contacts of COVID-19 cases. The relationship of transmission was indicated by transmission chain, and the infectivity was analyzed by the contact history.Results:This cluster of COVID-19 cases occurred after a classmate party involving members in three families and work fellows in a factory ( R0=3.8). The infection rate during the incubation period was 17.57%. On average, it was infectious three days before onset. There was significant difference in infection rate among different contact modes ( χ2=15.10, P<0.01), There was significant difference in infection rate among single exposureswith different time length ( χ2=25.08, P<0.01). Conclusions:COVID-19 is highly infectious in the incubation period. The more confined the space is, the higher the risk is,and the longer the single exposure is, the higher the risk of transmission is. Indirect contact transmission still exists

Objective:To analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) in cases of febrile respiratory syndrome in China from 2010 to 2020.Methods:Based on the sub-project of the National Science and Technology Major Project for Infectious Disease Prevention and Control "Infectious Disease Monitoring Technology Platform", active monitoring of febrile respiratory syndrome cases was conducted in sentinel hospitals in 31 provinces across China (excluding Hong Kong, Macau, and Chinese Taiwan) from January 2010 to December 2020, resulting in the inclusion of 191 441 cases. Clinical specimens of monitored cases were screened for HRSV nucleic acid, and the differences in HRSV detection rates among different age groups, regions, and time periods were analyzed using the χ 2 test/Fisher exact probability method. Results:Among the 191 441 cases of febrile respiratory syndrome in China from 2010 to 2020, the age group M ( Q1, Q3) was 9 (2, 40) years old, with 83 773 cases (43.8%) in the <5 years old group. There were 113 660 males, with a male-to-female ratio of 1.5∶1.0. There were as many as 105 508 cases (55.2%) of scattered children and preschool children. About 70 565 cases (36.9%) lived in the northern region. There were 13 858 HRSV positive cases, with a total positive rate of 7.2%. The positive rate of HRSV detection in the northern population was 5.7% (4 004/70 565), which was lower than that in the southern population (8.2%, 9 854/120 876), and the difference was statistically significant (χ 2=407.4, P<0.001). HRSV was detected in all age groups, with the highest positive rate of 23.9% in the <6 months age group. The month with the highest positive rate was December, and autumn and winter were the main epidemic seasons. Both northern and southern HRSV subtypes were mainly infected with type A, with a low proportion of mixed infections of type A and type B. Conclusion:HRSV is a common pathogen causing respiratory infections in children from 2010 to 2020. It can be detected throughout the year and shows the main peak of prevalence in autumn and winter. The HRSV strain is mainly classified as a type A infection.

Objective:To analyze the epidemiological characteristics of human respiratory syncytial virus (HRSV) in cases of febrile respiratory syndrome in China from 2010 to 2020.Methods:Based on the sub-project of the National Science and Technology Major Project for Infectious Disease Prevention and Control "Infectious Disease Monitoring Technology Platform", active monitoring of febrile respiratory syndrome cases was conducted in sentinel hospitals in 31 provinces across China (excluding Hong Kong, Macau, and Chinese Taiwan) from January 2010 to December 2020, resulting in the inclusion of 191 441 cases. Clinical specimens of monitored cases were screened for HRSV nucleic acid, and the differences in HRSV detection rates among different age groups, regions, and time periods were analyzed using the χ 2 test/Fisher exact probability method. Results:Among the 191 441 cases of febrile respiratory syndrome in China from 2010 to 2020, the age group M ( Q1, Q3) was 9 (2, 40) years old, with 83 773 cases (43.8%) in the <5 years old group. There were 113 660 males, with a male-to-female ratio of 1.5∶1.0. There were as many as 105 508 cases (55.2%) of scattered children and preschool children. About 70 565 cases (36.9%) lived in the northern region. There were 13 858 HRSV positive cases, with a total positive rate of 7.2%. The positive rate of HRSV detection in the northern population was 5.7% (4 004/70 565), which was lower than that in the southern population (8.2%, 9 854/120 876), and the difference was statistically significant (χ 2=407.4, P<0.001). HRSV was detected in all age groups, with the highest positive rate of 23.9% in the <6 months age group. The month with the highest positive rate was December, and autumn and winter were the main epidemic seasons. Both northern and southern HRSV subtypes were mainly infected with type A, with a low proportion of mixed infections of type A and type B. Conclusion:HRSV is a common pathogen causing respiratory infections in children from 2010 to 2020. It can be detected throughout the year and shows the main peak of prevalence in autumn and winter. The HRSV strain is mainly classified as a type A infection.

OBJECTIVETo study the quantitative measurement of the extent of malrotation after interlocking intramedullary nailing of femoral shaft fracture.

METHODCT scan ("routine method") applied in 36 femoral shaft fractures that had been treated with close reduction and interlocking intramedullary nailing. For the judgement of the extent of malrotation, the anteversion of both fracture side and contralateral side were measured and the difference between the 2 sides was evaluated. The increase of anteversion represented internal rotation of the distal fragment, whereas the decrease of anteversion represented external rotation.

RESULTSThe maximum anteversion of the fracture sides, whereas 48 degrees, the minimum anteversion -10 degrees, the mean value, 15.04 degrees, and the standard error is 11.34 degrees. The maximum anteversion of the contralateral side, whereas 31.3 degrees, minimum -4.8 degrees, the mean value was 13.96 degrees and the standard error was 10.20 degrees (P < 0.001). Compared with the contralateral side, half of the 36 cases showed increased anteversion and the other half decreased anteversion. The mean value of internal rotation is 11.56 degrees, and external rotation 9.39 degrees. The maximum internal rotation was 37 degrees, the minimum 0.9 degrees. Eight cases had internal rotation less than 8 degrees, 6 between 10 degrees - 15 degrees, and 4 over 15 degrees. The maximum external rotation was 24.3 degrees, and the minimum 1.8 degrees. Eleven cases had external rotation less than 10 degrees, 4 between 10 degrees - 15 degrees and 3 over 15 degrees. The incidence of malrotation more than 10 degrees was 47% (17/36), and more than 15 degrees 19.4% (7/36).

CONCLUSIONThe incidence of malrotation after femoral shaft fracture treated with close reduction and interlocking intramedullary nailing is high. Attention should be paid to clinical management and strict control for rotational reduction intra-operatively.

Adolescent ; Adult ; Bone Nails ; Female ; Femoral Fractures ; diagnostic imaging ; pathology ; surgery ; Fracture Fixation, Intramedullary ; methods ; Humans ; Male ; Middle Aged ; Rotation ; Tomography, X-Ray Computed