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60 curved root canals of permanent teeth with angles of curvature ranging from 15°to 40°(Schneider's methodology)were prepared using the instruments of Hyflex CM(HC) and ProTaper(PT) Universal respectively(n=30).Using standardized pre-and post-instrumentation paralleling periapical radiographs,canal curvature was determined by image analysis software and the clinical shaping effect of Hyflex CM and ProTaper rotary NiTi files were compared.The canal curvature in group HC and PT decreased by 4.54°±3.25° and 5.63°±3.84° respectively(between pre-and post-treatment in both groups,P0.05).Hyflex CM can meet the clinical necessity for the instrumentation of curved root canals.
ABSTRACT
Objective:To describe the secular trends of premarital medical examination ( PME ) in China during 1996 and 2013 and to assess the impacts of national health policies on the PME rate. Methods:The information on marriage and PME for districts and counties in 31 provinces of China was annually collected by the Office for National Maternal & Child Health Statistics of China, and the infor-mation on the health policies was from official governmental websites. According to the main health poli-cies, the calendar years were categorized into 3 periods:1996 to 2003 was mandatory PME period;2004 to 2008 was encouraged voluntary PME period; and 2009 to 2013 was free-paid voluntary PME period. Results: During the 18-year period, 284 242 719 people were registered for a marriage in which 107 198 795 were examined, giving the PME rate of 37. 7%. During the mandatory PME period, the rate ranged 52 . 7% -67 . 7% with an average of 60 . 9% ( urban 71 . 5%, and rural 51 . 7%) . In 2004 , the first year when the PME became voluntary, the rate was abruptly dropped to 2. 6%, and thereafter gradually increased to 11 . 5% in 2008 . As the policies of the free-paid voluntary PME were subsequently issued, the rate was quickly increased to 52. 3% (urban 49. 8%, and rural 54. 6%) in 2013. The in-creasing trend was consistently observed both in urban and rural areas, and across East, Middle, West, and Northeast economical regions. However, the rates differed greatly among provinces. In 2013, 5 pro-vinces had rates of >90% ( Guangxi 97 . 5%, Fujian 96 . 0%, Ningxia 95 . 4%, Zhejiang 93 . 4% and Anhui 90. 1%), whereas some provinces were stuck at a low rate, including developed and underdeve-loped provinces/cities. The PME rate in 2013 was 27. 4% for Shanghai, 25. 5% for Guangdong, 12. 4%for Chongqing, 5. 8% for Beijing and 4. 6% for Tianjin. Underdeveloped provinces were Guizhou (6. 4%) and Qinghai (1. 8%). Conclusion:As various national policies to promote voluntary PME were issued, the PME rate was significantly increased after a sharp decline, though it varied greatly by provinces. For provinces with high PME rate, PME-related health benefits need to be evaluated;for provinces with low rate, it is of important practical significance to explore a cost-effective health service model that is likely incorporated with pre-pregnancy examination.
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<p><b>OBJECTIVE</b>Field surveys were performed under WHO recommended validation procedures, using the Lot Quality Assurance-Cluster Sample(LQA-CS)method to validate the elimination status regarding neonatal tetanus in China.</p><p><b>METHODS</b>LQA-CS surveys were conducted in two areas under the highest risk of neonatal tetanus-Jiangmen prefecture in Guangdong and Hechi in Guangxi. Random sampling method was conducted on 96 survey clusters in each prefecture with 12 eligible live births(live birth born one year before the survey)for each cluster, by trained investigators.</p><p><b>RESULTS</b>There were 1 153 eligible live births from 23 465 families surveyed in Jiangmen and 1 152 eligible live births from 21 623 families being studied in Hechi. All the indices on quality control were strictly followed. There was no neonatal tetanus case which met the criteria of neonatal elimination found in either of the areas. Data showed that neonatal tetanus had been eliminated in both Jiangmen and Hechi cities.</p><p><b>CONCLUSION</b>Since both Jiangmen and Hechi were cities having the highest-risk in China, it was most likely that neonatal tetanus had also been eliminated in other prefectures at lower risk. Elimination programs on MNT was therefore considered validate in China when the study was carried out. However, the achievements needed to be maintained.</p>
Subject(s)
Humans , Infant, Newborn , China , Epidemiology , Lot Quality Assurance Sampling , Tetanus , EpidemiologyABSTRACT
The timing of marriages, first birth interval and the prevalence of premarital conception (PMC) among women of successive birth cohorts in one rural county in Yunnan, China, were examined. Detailed pregnancy histories were collected for 1,336 women aged 15-64 years using a Life History Calendar. The rising marriage age and shorter first birth interval correspond to over-all changes in the Chinese society over the same time period. The mean age at first marriage for women born before 1950 was just below 20, and 22.5 among women born 1976-1980. The later marriage age was partly offset by the dramatic shortening of the first birth interval from over 30 months in the oldest cohort to 11-12 months in the youngest. One explanation of the shortening of the first birth interval may be the increase in premarital conception. Among the young women in our study almost one-third of first pregnancies were conceived before marriage.