Objective:To analyze the wall thickness of C-shaped canals in permanent mandibular second molars.Methods:40 ex-tracted permanent mandibular second molars with C-shaped root were collected from native Chinese and were scanned by micro-CT scan-ner.The specimens were reconstructed three-dimensionally by software Mimics 10.01.The roots were sliced from cemento-enamel junc-tion (CEJ)to apex with 1 mm intervals.The cross-sectional root canal configurations were classified into 5 types according to the Fan's Classification.The minimum buccal wall thickness (MBWT),minimum lingual wall thickness(MLWT)and their locations,as well as the wall thickness at the mesial and distal reference sites were detected.Two-way ANOVA and post hoc LSD-t tests were used to com-pare the mean thickness at 4 sides.Results:Among 370 cross-sections of 40 C-shaped roots,C1,C2 and C3 canals were observed on 126(34.1%),46 (12.4%)and 160 (43.2%)sections respectively.Except at the 10 mm level,the mean MLWT was always lower than MBWT;and the MLWT and MBWT were always lower than the wall thickness at the mesial and distal reference sites.The differ-ence was statistically significant (P <0.05)along the root length above the 12 mm level.The MBWT of the C2 and C3 canals was more likely located at the mesial region,and the MBWT of the C1 and the MLWT of C1,C2 and C3 was more frequently located at the center region.Conclusion:The lingual wall of C-shaped canal in mandibualr second molars was the thinnest zone among four sides,and care should be taken during root canal instrumentation and post space preparation to avoid perforation.

Objective To explore the prevalence and management status of asthma in downtown of Qingdao City.Method A stratified-cluster-disproportional random sampling survey was conducted with uniform procedure and questionnaire.Results The overall incidence of asthma in Qingdao City was 3.12％ (188/6026).The 2 most frequently risk factors of asthma were the allergic history and the asthma heredity (OR =3.562,2.381,P ＜ 0.05 ).In 188 diagnosed asthma patients,only 65 (34.5％)asthma patients accepted the guideline therapy,and 51 (27.1％)of them achieved well-controlled or total control.The 2 common reasons for the poor compliance were fear of adverse drug reaciion and feeling of ineffectiveness of inhaled corticosteroids.Conclusion The population in urban area of Qingdao City is suffered with high prevalence of asthma,poor compliance of guideline treatment and terrible management status.

Non-invasive (NI) blood glucose measurement is a new method, this article deals with current researches and analyzes the advantages and shortages of different measurement methods, including electrochemical process and Optical methods (transmission, polarimetry and back scattering). Then, the technology of near-infrared spectra is emphasized in the analysis. Finally, the problem and technical analysis of non-invasive (NI) blood glucose measurement at the present time are discussed. We preliminarily aim at the method of NI blood glucose determination and the original concept of measuring apparatus, including the choice of incident light wavelength, determination of receiver point, establishment of the optical model of biological tissue, and apparatus design.
Blood Glucose ; analysis ; Blood Glucose Self-Monitoring ; instrumentation ; methods ; Diagnosis, Computer-Assisted ; instrumentation ; Equipment Design ; Humans

Objective To evaluate the safety and effectiveness of ultra-hypofractionated stereotactic body radiotherapy in the treatment of prostate cancer.Methods A total of 26 patients with prostate cancer treated with Cyber-Knife from May 2010 to May 2018 were analyzed retrospectively.The median age of the patients was 69 years old (range,57 to 87).Ultra-hypofractionated radiotherapy was delivered in five fractions of 7.0-7.5 Gy for a total dose of 35.0-37.5 Gy.Androgen deprivation therapy (ADT) was administered in combination with the Cyber-Knife.The primary endpoints were radiation toxicity,PSA-response,local control and symptom alleviation,while the secondary endpoints were progression-free survival and overall survival.Results No graded ≥ 3 acute and late radiation toxicities occurred during follow-up.The acute toxicity of Grades 1 and 2 was 38.4％ and 19.2％,while the late toxicity of Grades 1 and 2 was 30.8％ and 3.8％,respectively.At a median follow-up of 22.44 months,for patients with localized stage,PSA level was decreased significantly after radiotherapy (Z =2.900,2.794,2.510,2.090,P＜0.05).However,there was no statistically significant difference for the metastatic group (P＞ 0.05).Conclusions Ultra-hypofractionated stereotactic body radiotherapy is a safe and effective treatment for patients with prostate cancer.

Objective To analyze the radiation dose to the normal lung tissue of patients with early stage of non-small cell lung cancer treated by Cyberknife. Methods A retrospective analysis was conducted by summarizing the treatment plans of 264 patients with early stage non-small cell lung cancer from January 2011 to December 2013 in Tianjin Medical University Cancer Institute and Hospital. Sorted by the tumor volumes and locations, the Cyberknife plans were evaluated by means of dose volume histograms ( DVH) , homogeneity indexes ( HI) , percentage volumes receiving at least x Gy ( Vx ) of dose, i. e. , V5 , V10 , V20 , and V30 of the ipsilateral and contralateral lungs. For the tumors approximate to the hilus, the contralateral lungs were included in the optimization process, and the dose-volume metrics were analyzed for the contralateral and bilateral lungs. Results For the tumors close to the chest wall, V5≥(15. 21 ± 3. 12)％ in ipsilateral lung tissue and V5≥(1. 34 ± 0. 67)％ in contralateral lung tissue were observed. For the tumors near the hilus, V5≥(39. 4 ± 11. 90) ％ in ipsilateral lung tissue and V5≥(1. 48 ± 0. 34) ％ in contralateral lung tissue were observed. The irradiated volume ratios of both ipsilateral and contralateral lung tissue increased with the enlargement of tumor sizes. After including the contralateral lung tissue into the optimization, the irradiated volume ratios of the contralateral and bilateral lung tissue (V5,V10) decreasedsignificantly(t=2.44,4.81,3.53,3.17,P<0.05). Conclusions Higherriskof radiation injury in both ipsilateral and contralateral lung tissue can be expected for tumors near the hilus than near the chest wall. After including contralateral lung tissue into the planning optimization, lower dose to the contralateral and whole lung tissue was achieved, indicating a better protection of normal lung tissue.