Objective To measure the course of the mandibular canal in mandibula posterior area by cone-beam computed tomography ( CBCT ) , to provide a theoretical support for implant preoperative assessment. Methods Mandibular data of 65 people measured by CBCT were collected, measured the distance between mandibular canal around the bone wall and analyzed the differences by gender and the differences between the left and the right. Results The average distance of mandibular canal outer edge to the buccal bone plate by former backward in-creased gradually,at least in the area of the mental formen, at largest in the area of the mental foramen after 18 mm. The average distance between mandibular canal inner edge to lingual bone plate by former backward reduced gradually, at largest in the area of the mental foramen,at least in the area of the mental foramen after 18 mm. The average distance between mandibular canal upper edge to alveolar crest by former backward reduced gradually,at largest in the area of the mental foramen, at least in the area of the mental foramen after 18 mm. The average dis-tance between the edge of mandibular canal to the edge of mandible by former backward reduced previous,then in-creased, at least in the area of the mental foramen after 6 mm, at largest in the area of the mental foramen after 18 mm. All the results had no significant statistical differences between the male and the female, and had no significant statistical differences between the left and the right. Conclusion The trajectory of the mandibular canal from front to back is downward first, then upward in the mesial of the first molar in the vertical, and whose from the buccal side to the lingual side. That has significance for assessment before implant in mandibular posterior area.

This study was aimed to objectify Color Inspection in Traditional Chinese Medicine (CITCM). A quantita-tive system for CITCM was designed and developed. The entire system included two parts, which were the hardware and the software. The hardware was an image acquisition device in a standard lighting condition. The software was used for digital image processing. The chromaticity of facial special region (SR) corresponding to five internal organs were calculated. The system was carried out by taking 100 samples of people. It was concluded that the experiment verified the effectiveness of the system in objective study of CITCM. It can be used as basis for the further study on CITCM.

Aseptic loosening of the prosthesis is a major form for the failure of artificial joints, which results in the conglomeration of wear particles at the bone-implant interface. This paper briefly reviews the recent development of tribology of artificial joints preserving good lubrication, enhancing the wear resistance of materials for the joints, reducing the generation of sensitive-size particles and depressing the debris-tissue reactions. Suggestion for improvement in the design of artificial joints is presented.
Biocompatible Materials ; chemistry ; Equipment Failure Analysis ; Friction ; Humans ; Joint Prosthesis ; trends ; Lubrication ; Prosthesis Failure

Objective : To study the epidemiological characteristics of coronavirus disease 2019 （COVID-19） in Zhoushan, so as to provide reference for improving the prevention and control capability of COVID-19. Methods : All the confirmed cases of COVID-19 in Zhoushan, diagnosed according to China’s “COVID-19 diagnosis and treatment plan （fifth version） ” and reported from January 19 to February 17, 2020, were extracted from the infectious disease surveillance system. Data of general information, clinical characteristics, laboratory Results, transmission and detection routes were collected and analyzed. Results : By February 17, Ten confirmed cases of COVID-19 in Zhoushan had been reported, including 7 males and 3 females. They were all adults, with an average age of （50.90±15.00） years. Five cases were discharged. The incubation period ranged from 2 to 12 days, with a median of 5 days. The first symptoms were fever （8 cases）, cough （7 cases） and muscle pain （2 cases）. Chest computed tomographic （CT） scans showed ground glass opacities in the lungs of all the cases. Six cases had Wuhan related exposure. SARS-CoV-2 was tested positive in the sputum specimens or throat swabs of all the cases and the faeces of 4 cases. The last suspicious exposure of 5 cases occurred before, and that of another 5 cases occurred after the onset of clinical symptoms in the confirmed maternal cases. Three cases were found in active consultation after clinical symptoms, and another 7 cases were found in the monitoring of close contacts. Conclusions The 10 confirmed cases of COVID-19 reported in Zhoushan are all adults, and most have Wuhan related exposure. SARS-CoV-2 can be detected in the fecal samples, but the existence of fecal-oral transmission needs more research. SARS-CoV-2 has strong infectivity, and may also have infectivity before the onset of symptoms （at the end of incubation period）. Isolation and early detection of close contacts are conducive for early case-finding.