1.Comparison of the failure mode of various types of glass ionomer cements.
Yan WANG ; Xin-chun ZHANG ; B W DARVELL
Chinese Journal of Stomatology 2006;41(11):687-689
<b>OBJECTIVEb>To investigate the failure mode of various types of glass ionomer cements by Hertzian indentation test.
<b>METHODSb>Discs of 10 mm diameter and 2 mm thickness were prepared for six glass ionomer cement products (A-D: conventional type setting through an acid-base chemical reaction, A and B without reinforcement, C with silver reinforcement, D with ceramic reinforcement; E and F: resin-modified type), ten for each. These were tested on top of glass-reinforced polyamide-nylon 6, 6 substrates by a universal testing machine, loading centrally with a 20 mm diameter ball. Load at the first crack was recorded. Failure mode was observed under scanning electron microscope.
<b>RESULTSb>The former four products presented typical brittle fracture, while the latter two usually fractured incompletely. The failure loads at the first crack of the six glass ionomer cements were (258.86 +/- 10.49), (230.88 +/- 21.66), (281.90 +/- 25.39), (282.11 +/- 9.60), (756.67 +/- 83.50) and (1 148.00 +/- 147.78) N, respectively. Significant difference was found between the former four and the latter two products.
<b>CONCLUSIONSb>The type (setting mode) of glass ionomer cement controls its failure mode. Inclusion of metallic or ceramic filler has little effect on increasing the load bearing capacity of glass ionomer cement.
Compressive Strength ; Dental Porcelain ; chemistry ; Glass Ionomer Cements ; chemistry ; Materials Testing ; methods ; Resins, Synthetic ; chemistry ; Silver ; chemistry
2.The status quo of service quality evaluation of pension institutions in China and research progress.
L W ZHANG ; Y B ZENG ; L X WANG ; Y FANG
Chinese Journal of Epidemiology 2018;39(11):1524-1529
With the accelerating process of population aging in China, social pension system has been rapidly developed, but its service quality remains poor. How to provide quality and efficient elderly care services has become a major livelihood issue of general public. The existing evaluation standards for service quality in the elderly care institutions vary greatly in terms of literature review and practice, and they have only single perspective and lack systematic review. Based on the three-dimensional theory of "structure-process-result" quality evaluation, this paper systematically compares and evaluates the evaluation index system and evaluation management mechanism of service quality of pension institutions in typical countries and regions, and provides an evidence-based basis for establishing an evaluation management system, which is in line with China's national conditions and covers evaluation principles, subject and object, regulation, rewards and punishments, and classifications.
Aged
;
Aging
;
China
;
Humans
;
Pensions
;
Research
3.A case of human infection with highly pathogenic avian influenza A (H7N9) virus through poultry processing without protection measure.
Y MA ; Z B ZHANG ; L CAO ; J Y LU ; K B LI ; W Z SU ; T G LI ; Z C YANG ; M WANG
Chinese Journal of Epidemiology 2018;39(6):799-804
<b>Objective:b> To investigate the infection pattern and etiological characteristics of a case of human infection with highly pathogenic avian influenza A (H7N9) virus and provide evidence for the prevention and control of human infection with highly pathogenic avian influenza virus. <b>Methods:b> Epidemiological investigation was conducted to explore the case's exposure history, infection route and disease progression. Samples collected from the patient, environments and poultry were tested by using real time reverse transcriptase-polymerase chain reaction (RT-PCR). Virus isolation, genome sequencing and phylogenetic analysis were conducted for positive samples. <b>Results:b> The case had no live poultry contact history, but had a history of pulled chicken processing without taking protection measure in an unventilated kitchen before the onset. Samples collected from the patient's lower respiratory tract, the remaining frozen chicken meat and the live poultry market were all influenza A (H7N9) virus positive. The isolated viruses from these positive samples were highly homogenous. An insertion which lead to the addition of multiple basic amino acid residues (PEVPKRKRTAR/GL) was found at the HA cleavage site, suggesting that this virus might be highly pathogenic. <b>Conclusions:b> Live poultry processing without protection measure is an important infection mode of "poultry to human" transmission of avian influenza viruses. Due to the limitation of protection measures in live poultry markets in Guangzhou, it is necessary to promote the standardized large scale poultry farming, the complete restriction of live poultry sales and centralized poultry slaughtering as well as ice fresh sale.
Animals
;
Chickens
;
China
;
Commerce
;
Humans
;
Influenza A Virus, H7N9 Subtype/pathogenicity*
;
Influenza in Birds/virology*
;
Influenza, Human/virology*
;
Phylogeny
;
Poultry/virology*
;
Real-Time Polymerase Chain Reaction
;
Zoonoses
4.Estimation on the health life expectancy of adults in Zhejiang province, 2016.
F R FEI ; R Y HU ; X Y WANG ; J M ZHONG ; W W GONG ; J PAN ; H B WU ; M WANG ; H WANG ; M YU
Chinese Journal of Epidemiology 2018;39(9):1249-1254
<b>Objective:b> To estimate the health-adjusted life expectancy (HALE) of adults in Zhejiang province and evaluate the health status of the adults. <b>Methods:b> This study was based on the mortality data collected from Zhejiang Chronic Disease Surveillance Information and Management System, and mortality rates from the underreporting survey and self-reported health data in 2016. Hierarchical Ordered Probit (HOPIT) model was used to estimate the severity-weighted prevalence of disability. Sullivan's method was used to calculate the HALE. <b>Results:b> After adjustment by HOPIT model, the severity-weighted prevalence of disability increased significantly with age (χ(2)=5 795.81,P<0.001), and it was higher in females than in males (χ(2)=5 353.27, P<0.001). The life expectancy and self-evaluated HALE were 59.08 years and 48.68 years, respectively, in those aged ≥20 years, the difference was 10.40 years due to disability. The proportion of HALE loss due to disability in the total life expectancy was 17.61%, and it increased with age. HALE was higher in males than in females (49.21 years vs. 48.14 years), and in urban residents than in rural residents (49.92 years vs. 47.43 years). <b>Conclusion:b> The proportion of loss of HALE in the total life expectancy in adults was high in Zhejiang, and it higher in males than in females, in urban residents than rural residents. Programs on improving health care in women and rural residents should be promoted.
Adult
;
China/epidemiology*
;
Chronic Disease/epidemiology*
;
Disabled Persons/statistics & numerical data*
;
Female
;
Health Status
;
Humans
;
Life Expectancy/ethnology*
;
Male
;
Middle Aged
;
Prevalence
;
Sex Distribution
5.IgG4-Associated Cholangitis Can Mimic Hilar Cholangiocarcinoma.
Victor M ZAYDFUDIM ; Andrew Y WANG ; Eduard E DE LANGE ; Zimin ZHAO ; Christopher A MOSKALUK ; Todd W BAUER ; Reid B ADAMS
Gut and Liver 2015;9(4):556-560
IgG4-associated cholangitis can mimic hilar cholangiocarcinoma. Previously reported patients with IgG4-associated cholangitis mimicking cholangiocarcinoma had elevated serum IgG4 levels and long-segment biliary strictures. However, in the absence of other diagnostic criteria for malignancy, IgG4-associated cholangitis should remain a consideration among patients with normal serum IgG4 and a hilar mass suspicious for cholangiocarcinoma. The presence of a hilar mass and a malignant-appearing biliary stricture in two patients with normal serum IgG4 prompted further evaluation and subsequent concomitant liver and bile duct resection and reconstruction. The diagnosis of IgG4-associated cholangitis was established during the pathologic evaluation of the resected specimens. IgG4-associated cholangitis is a known imitator of hilar cholangiocarcinoma and should be considered in the differential diagnosis even among serologically IgG4-negative patients with a hilar mass prior to operative resection.
Aged
;
Bile Ducts/pathology/surgery
;
Cholangitis/blood/*diagnosis
;
Diagnosis, Differential
;
Humans
;
Immunoglobulin G/*blood
;
Klatskin Tumor/blood/*diagnosis
;
Liver/pathology/surgery
;
Male
6.Dynamic path analysis on life course epidemiology.
Z W TIAN ; G Y ZENG ; S L WU ; L T HUANG ; B Z WANG ; H Z TAN
Chinese Journal of Epidemiology 2018;39(1):86-89
In the studies of modern epidemiology, exposure in a short term cannot fully elaborate the mechanism of the development of diseases or health-related events. Thus, lights have been shed on to life course epidemiology, which studies the exposures in early life time and their effects related to the development of chronic diseases. When exploring the mechanism leading from one exposure to an outcome and its effects through other factors, due to the existence of time-variant effects, conventional statistic methods could not meet the needs of etiological analysis in life course epidemiology. This paper summarizes the dynamic path analysis model, including the model structure and significance, and its application in life course epidemiology. Meanwhile, the procedure of data processing and etiology analyzing were introduced. In conclusion, dynamic path analysis is a useful tool which can be used to better elucidate the mechanisms that underlie the etiology of chronic diseases.
Chronic Disease/epidemiology*
;
Epidemiologic Studies
;
Humans
;
Models, Theoretical
;
Risk Factors
;
Time
8.A summary of item and method of national chronic obstructive pulmonary disease surveillance in China.
L W FANG ; H L BAO ; B H WANG ; Y J FENG ; S CONG ; N WANG ; J FAN ; L H WANG
Chinese Journal of Epidemiology 2018;39(5):546-550
COPD refers to a group of chronic respiratory diseases which seriously influence the people's health and life quality. The national COPD surveillance in China has been implemented since 2014 with the goal of monitoring the prevalence and trend of COPD and related risk factors in China. The paper summarizes the item and method of national COPD surveillance in China.
Aged
;
China/epidemiology*
;
Chronic Disease/psychology*
;
Female
;
Humans
;
Male
;
Middle Aged
;
Population Surveillance/methods*
;
Prevalence
;
Pulmonary Disease, Chronic Obstructive/psychology*
;
Quality of Life
;
Risk Factors
9.Survey of smoking prevalence in adults aged 40 years and older in China, 2014.
N WANG ; Y J FENG ; H L BAO ; S CONG ; J FAN ; B H WANG ; L H WANG ; L W FANG
Chinese Journal of Epidemiology 2018;39(5):551-556
<b>Objective:b> Smoking is the most important risk factor for COPD. Understanding the smoking rate, current smoking rate, average age to start smoking and average daily consumption of cigarettes among people aged ≥40 years in China can provide scientific evidence for the effective control and prevention of COPD. <b>Methods:b> Data were from COPD surveillance in China (2014 to 2015) which covered 31 provinces, autonomous regions and municipalities. A total of 75 107 adults aged ≥40 years selected through multi-stage stratified cluster sampling from 125 surveillance sites (county/district) were surveyed by electronic questionnaire during face to face interviews. The smoking rate and other smoking index were estimated by using weighting complex sampling design. <b>Results:b> The smoking rate and current smoking rate were 40.0% (95%CI: 38.5%-42.0%) and 31.0% (95%CI: 29.7%-32.0%), respectively, among the Chinese aged ≥40 years in 2014. The smoking rate and current smoking rate in males (74.1% and 57.6%) were much higher than those in females (5.4% and 4.0%). And the two rates were significantly higher in rural area (41.2% and 32.4%) than in urban area (38.8% and 29.5%). The mean age of smokers to start smoking was 20.1 (95%CI: 19.7-20.5) years. The younger the smokers were, the earlier their average age to start smoking was (The ages to start smoking for smokers aged 40-, 50-, 60-, ≥70 years were 18.3, 19.2, 20.9 and 23.1 years, respectively). Average daily cigarette consumption of current daily smokers was 18.9 (95%CI: 18.1-19.7) cigarettes, and the daily cigarette consumption was higher in males (19.3 cigarettes) than in females (12.5 cigarettes). <b>Conclusion:b> The smoking rate in males aged ≥40 years is high in China. Compared with urban area, the smoking rate in rural area is higher, posing a big challenge for COPD control and prevention.
Adult
;
Aged
;
Asian People/statistics & numerical data*
;
China/epidemiology*
;
Female
;
Humans
;
Male
;
Prevalence
;
Risk Factors
;
Smoking/psychology*
;
Smoking Cessation
;
Surveys and Questionnaires
;
Young Adult
10.Analysis on passive smoking exposure in adults aged 40 years and older in China, 2014.
S CONG ; Y J FENG ; H L BAO ; N WANG ; J FAN ; B H WANG ; L H WANG ; L W FANG
Chinese Journal of Epidemiology 2018;39(5):557-562
<b>Objective:b> To describe and analyze the passive smoking exposure level in adults aged ≥40 years in China. <b>Methods:b> A total of 75 107 adults from 125 sites of COPD surveillance points in China were surveyed by electronic questionnaire during face to face interviews. After comprehensive weighting of the samples, the passive smoking exposure level was analyzed. <b>Results:b> The passive smoking exposure rate of the adults aged ≥40 years was 44.9% (95%CI: 42.3%-47.5%). The exposure rate was highest in those aged from 40 to 49 years (51.0%, 95%CI: 47.9%-54.1%) in term of age groups, in those with senior high school education level and above (48.6%, 95%CI: 44.9%-52.2%) in term of education level, and in office workers (57.7%, 95%CI: 51.8%-63.7%) in term of occupation. The adults reporting passive smoking exposure every days in a week accounted for 27.7% (95%CI: 25.5%-29.8%), and those reporting household passive smoking exposure accounted for 28.3% (95%CI: 26.2%-30.5%). Logistic regression analysis showed that the passive smoking exposure level was different in different age groups and occupation groups. <b>Conclusion:b> The passive smoking exposure level is still high in adults in China. Age and occupation are the influencing factors of passive smoking exposure level.
Adult
;
Aged
;
Asian People/statistics & numerical data*
;
China/epidemiology*
;
Environmental Exposure
;
Family Characteristics
;
Female
;
Humans
;
Male
;
Middle Aged
;
Population Surveillance/methods*
;
Smoking/epidemiology*
;
Surveys and Questionnaires
;
Tobacco Smoke Pollution/statistics & numerical data*