This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the r...This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the revenue over expectation problem.Properties of RR-ER model and the consistency between RR-ER model and traditional risk measure model with regard to continuous random variables are discussed.Case analysis is presented to prove the practicality and efficiency of this new method.展开更多
In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function ...In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function and the properties of the estimator by using methods of numerical modeling are discussed. In the model under consideration, the estimates were compared using numerical methods to determine which of the estimates is actually better.展开更多
Refined risk prediction must be achieved to guarantee the safe and steady operation of chemical production processes.However,there is high nonlinearity and association coupling among massive,complicated multisource pr...Refined risk prediction must be achieved to guarantee the safe and steady operation of chemical production processes.However,there is high nonlinearity and association coupling among massive,complicated multisource process data,resulting in a low accuracy of existing prediction technology.For that reason,a real-time risk prediction method for chemical processes based on the attention-based bidirectional long short-term memory(Attention-based Bi-LSTM)is proposed in this study.First,multisource process data,such as temperature,pressure,flow rate,and liquid level,are preprocessed for denoising.Data correlation is analyzed in time windows by setting time windows and moving step lengths to explore correlations,thus establishing a complex network model oriented to the chemical production process.Second,network structure entropy is introduced to reduce the dimensions of the multisource process data.Moreover,a 1D relative risk sequence is acquired by maxemin deviation standardization to judge whether the chemical process is in a steady state.Finally,an Attention-based Bi-LSTM algorithm is established by integrating the attention mechanism and the Bi-LSTM network to fit and train 1D relative risk sequences.In that way,the proposed algorithm achieves real-time prediction and intelligent perception of risk states during chemical production.A case study based on the Tennessee Eastman process(TEP)is conducted.The validity and reasonability of the proposed method are verified by analyzing distribution laws of relative risks under normal and fault conditions.Also,the proposed algorithm importantly improves the prediction accuracy of chemical process risks relative to that of existing prediction technologies.展开更多
Objective:The spectrum and risk of cancer in relatives of BRCA1/2 pathogenic variant carriers in the Chinese population have not been established.Methods:A family history of cancer in 9903 unselected breast cancer pat...Objective:The spectrum and risk of cancer in relatives of BRCA1/2 pathogenic variant carriers in the Chinese population have not been established.Methods:A family history of cancer in 9903 unselected breast cancer patients was retrospectively analyzed.BRCA1/2 status was determined for all patients and relative risks(RRs)were calculated to evaluate cancer risk in relatives of the patients.Results:The incidences of breast cancer in female relatives of BRCA1 carriers,BRCA2 carriers,and non-carriers were 33.0%,32.2%,and 7.7%,respectively.The corresponding incidences of ovarian cancer were 11.5%,2.4%,and 0.5%,respectively.The incidences of pancreatic cancer in male relatives of BRCA1 carriers,BRCA2 carriers,and non-carriers were 1.4%,2.7%,and 0.6%,respectively.The corresponding incidences of prostate cancer were 1.0%,2.1%,and 0.4%,respectively.The risks of breast and ovarian cancers in female relatives of BRCA1 and BRCA2 carriers were significantly higher than female relatives of non-carriers(BRCA1:RR=4.29,P<0.001 and RR=21.95,P<0.001;BRCA2:RR=4.19,P<0.001 and RR=4.65,P<0.001,respectively).Additionally,higher risks of pancreatic and prostate cancers were noted in male relatives of BRCA2 carriers than non-carriers(RR=4.34,P=0.001 and RR=4.86,P=0.001,respectively).Conclusions:Female relatives of BRCA1 and BRCA2 carriers are at increased risk for breast and ovarian cancers,and male relatives of BRCA2 carriers are at increased risk for pancreatic and prostate cancers.展开更多
Objective To estimate the relative risks of dyslipidemia, hypertension, diabetes mellitus, and metabolic syndromes among overweight and obese Chinese children compared with their normal weight counterparts. Methods Ov...Objective To estimate the relative risks of dyslipidemia, hypertension, diabetes mellitus, and metabolic syndromes among overweight and obese Chinese children compared with their normal weight counterparts. Methods Overweight and obesity were defined by age- and sex-specific BMI classification reference for Chinese children and adolescents. Pediatric metabolic syndrome （MetS） and each risk factor for MetS were defined using the criteria for US adolescents. Definition of hyper-TC, LDL, and dyslipidemia for adults was applied as well. General linear model factor analysis and chi-square test were used to compare the difference in metabolic indicators among normal weight, overweight, and obese groups. Multiple logistic regression analysis was performed to estimate the odds ratio of metabolic abnormalities between obesity, overweight, and normal weight children, after adjustment for living area, family economic level, age, sex, and daily exercise time and TV watching time, as well as different dietary indices in the model. Results Significant increases in blood lipids, glucose, and blood pressure were found among overweight and obese children as compared with their counterparts with normal weight. By applying WGOC-recommended BMI classification, the risks for hypertriglyceridemia, low HDL and dyslipidemia among overweight children were 1.9, 1.4, and 1.5 times, and was 3.3, 1.5, and 1.8 times among obese groups compared to their counterparts with normal weight after adjustment for age, sex, region, socioeconomic status, physical activity, and dietary intakes. The overweight and obese children （15-17.9 years） had a high-risk of developing hypertension, which was 2.3 and 2.9 times higher than their counterparts with normal weight. Above 90% obese adolescents had abdominal obesity, while less than 1% normal weight ones had abdominal obesity. No obese adolescents were free from any risk factors for MetS, while 36.9% of normal weight adolescents were from the risk factors. 83.3% obese boys and all obese girls had metabolic syndrome, while only 15.5% normal weight boys and 18.8% normal weight girls had metabolic syndrome. Four risk factors for metabolic syndrome were found in 8.3% obese boys while none in normal weight boys and girls. The prevalence of MetS among normal weight, overweight, and obesity groups was 1.5%, 18.3%, and 38.1% respectively. Conclusion The cardiovascular disease （CVD） risk factors are clustered in obese Chinese children. Our observations strongly suggest that efforts should be made to prevent the onset of overweight and its associated diseases during early childhood.展开更多
Objective:To assess whether people who ever use any form of chewing substance in Asia are at increased risk of cardiovascular disease(CVD).Methods:PubMed and ISI Web of Science were searched for relevant studies,with ...Objective:To assess whether people who ever use any form of chewing substance in Asia are at increased risk of cardiovascular disease(CVD).Methods:PubMed and ISI Web of Science were searched for relevant studies,with no limitation on language or study year.Studies were included if they provided quantitative estimate of the association between ever use of chewing substance and the occurrence of CVD.Two authors independently implemented inclusion criteria,abstracted study characteristics,and performed meta-analysis.Summary relative risks were estimated on the basis of a random effect model.We used Q statistic and Egger's test to examine heterogeneity across studies and potential publication bias,respectively.Results:Eight eligible studies were included.The relative risk of CVD for ever using chewing substances with or without tobacco was 1.26(95% confidence interval(CI) 1.12-1.40),which was unchanged when restricted to cohort studies [1.25(1.08-1.42)] or cohort studies in Taiwan [1.31(1.12-1.51)].The summary relative risk for ischemic heart disease was 1.27(1.02-1.52),and was lowered to 1.26(0.85-1.67) after exclusion of a cross-sectional study.The overall relative risk for cerebrovascular disease was 1.32(1.08-1.56).On the basis of the Taiwan data,the summary relative risk of CVD for betel(Areca catechu) chewing was 1.30(1.17-1.44).Data on dose-response were limited to betel chewing in Taiwan,suggesting a relationship between risk of CVD and cumulative exposure.Two large cohorts in Taiwan reported a greater risk of CVD with betel chewing than with smoking.Conclusions:An association was detected between betel chewing with or without tobacco and the risk of CVD.Betel chewing may impose a greater CVD risk than smoking.More effort is needed in developing betel chewing cessation programmes.The relationship between betel chewing and subgroups of CVD requires further investigation.展开更多
There is evidence that a substantial part of genetic predisposition to prostate cancer （PCa） may be due to lower penetrance genes which are found by genome-wide association studies. We have recently conducted such a...There is evidence that a substantial part of genetic predisposition to prostate cancer （PCa） may be due to lower penetrance genes which are found by genome-wide association studies. We have recently conducted such a study and seven new regions of the genome linked to PCa risk have been identified. Three of these loci contain candidate susceptibility genes： MSMB, LMTK2 and KLK2/3. The MSMB and KLK2/3 genes may be useful for PCa screening, and the LMTK2 gene might provide a potential therapeutic target. Together with results from other groups, there are now 23 germline genetic variants which have been reported. These results have the potential to be developed into a genetic test. However, we consider that marketing of tests to the public is premature, as PCa risk can not be evaluated fully at this stage and the appropriate screening protocols need to be developed. Follow-up validation studies, as well as studies to explore the psychological implications of genetic profile testing, will be vital prior to roll out into healthcare.展开更多
Using expectations regarding utilities to make decisions in a risk environment hides a paradox,which is called the expected utility enigma.Moreover,the mystery has not been solved yet;an imagined utility function on t...Using expectations regarding utilities to make decisions in a risk environment hides a paradox,which is called the expected utility enigma.Moreover,the mystery has not been solved yet;an imagined utility function on the risk-return plane has been applied to establish the mean-variance model,but this hypothetical utility function not only lacks foundation,it also holds an internal contradiction.This paper studies these basic problems.Through risk preference VNM condition is proposed to solve the expected utility enigma.How can a utility function satisfy the VNM condition?This is a basic problem that is hard to deal with.Fortunately,it is found in this paper that the VNM utility function can have some concrete forms when individuals have constant relative risk aversion.Furthermore,in order to explore the basis of mean-variance utility,an MV function is founded that is based on the VNM utility function and rooted in underlying investment activities.It is shown that the MV function is just the investor's utility function on the risk-return plane and that it has normal properties.Finally,the MV function is used to analyze the laws of investment activities in a systematic risk environment.In doing so,a tool,TRR,is used to measure risk aversion tendencies and to weigh risk and return.展开更多
AIM: To quantitatively evaluate the impact of smoking on tooth loss.METHODS: We performed a Pub Med search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their v...AIM: To quantitatively evaluate the impact of smoking on tooth loss.METHODS: We performed a Pub Med search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using metaregression models. RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73(95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers(1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers(2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.展开更多
Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a phloem-feeding beetle native to Asia that is causing widespread mortality of ash trees in eastern North America. In this study, we quant...Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a phloem-feeding beetle native to Asia that is causing widespread mortality of ash trees in eastern North America. In this study, we quantify ash mortality risk associated with potential anthropogenic-induced introduction of Emerald Ash Borer (EAB) in North Dakota. The cohort model is calibrated with data from Ohio using weighting across factors—proximity to existing ash stands, campgrounds, roads and rails—to get a more accurate assessment of overall ash mortality risk. These factors are known to be associated with introduction of EAB to unaffected areas. Two protocols, a) “detection trees” and b) EAB traps are utilized to investigate EAB presence. Ash mortality risk maps such as the ones produced here may guide the placement of traps. Although North Dakota regions of high density ash tree stands are few, the resulting relative ash mortality risk map displays: a) very high risk areas around the Turtle Mountains and Theodore Roosevelt National Park and b) regions of high relative risk along the main riparian corridors. The applicability of risk maps such as the one developed may aid in assessing areas that may require significant monitoring.展开更多
Background:It has been well-established that acute radiation exposures increase the risk of leukemia.However,it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations ...Background:It has been well-established that acute radiation exposures increase the risk of leukemia.However,it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations who receive repeated low-dose radiation exposure.The purpose of this study was to estimate quantified associations between low-dose radiation exposures and leukemia.Methods:The Chinese medical X-ray worker study(CMXW)included 27,011 medical X-ray workers employed at major hospitals in 24 provinces in China from 1950 to 1980,and a control population of 25,782 physicians matched by hospital,who were unexposed to X-ray equipment.Poisson regression models were used to esti-mate the excess relative risk(ERR)and excess absolute risk(EAR)for the incidence of leukemia associated with cumulative doses.A meta-analysis of the published literature on low-dose occupational radiation exposure and leukemia risk was also conducted.Results:The incidence rates of leukemia in X-ray workers and the control group were 6.70 and 3.39 per 100,000 person-years,respectively.Among X-ray workers,the average cumulative red bone marrow dose was 0.046 Gy.We found a positive relationship between 2-year lagged cumulative red bone marrow dose and risk of leukemia excluding chronic lymphocytic leukemia(CLL)(ERR=0.66 per 100 mGy,90%CI:0.09,1.53;EAR=0.29 per 104 PY-100 mGy,90%CI:0.07,0.56).The excess risk was largely driven by myeloid leukemia(ERR=1.06 per 100 mGy,90%CI:0.22,2.51).Based on the meta-analysis,the pooled ERR at 100 mGy was 0.19(95%CI:0.08,0.31).Conclusion:This study provides strong evidence of a positive and linear doseresponse relationship between cu-mulative red bone marrow dose and the incidence of non-CLL leukemia.展开更多
Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populat...Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populations,particularly for pneumonia.Methods We developed a method to evaluate risks from airborne microorganisms,guided by the principle that closer evolutionary relationships reflect similar biological characteristics,and thus used16 S rDNA sequences of 10 common pneumonia-related bacterial pathogens.We calculated a risk of breath-related(Rbr)index of airborne bacterial communities and verified effectiveness with artificial flora and a clinical project.Results We suggested applying Rbr80 to evaluate the health risks of airborne bacterial communities that comprise 80% of dominant operational taxonomic units(OTUs).The feasibility of Rbr80 was confirmed by artificial flora and by pneumonia data from a hospital.A high Rbr80 value indicated a high risk of pneumonia from airborne bacterial communities.Conclusion Rbr80 is an effective index to evaluate the pneumonia-associated risk from airborne bacteria.Values of Rbr80 greater than 15.40 are considered high risk.展开更多
Risk assessment and uncertainty approximation are two major and important parameters that need to be adopted for the development of pharmaceutical process to ensure reliable results.Additionally,there is a need to swi...Risk assessment and uncertainty approximation are two major and important parameters that need to be adopted for the development of pharmaceutical process to ensure reliable results.Additionally,there is a need to switch from the traditional method validation checklist to provide a high level of assurance of method reliability to measure quality attribute of a drug product.In the present work,evaluation of risk profile,combined standard uncertainty and expanded uncertainty in the analysis of acyclovir were studied.Uncertainty was calculated using cause-effect approach,and to make it more accurately applicable a method was validated in our laboratory as per the ICH guidelines.While assessing the results of validation,the calibration model was justified by the lack of fit and Levene＇s test.Risk profile represents the future applications of this method.In uncertainty the major contribution is due to sample concentration and mass.This work demonstrates the application of theoretical concepts of calibration model tests,relative bias,risk profile and uncertainty in routine methods used for analysis in pharmaceutical field.展开更多
[Objectives]Metabolic obese normal weight(MONW)is becoming one of the pubic problems which are threatening human health.Whereas,MONW was facing a great challenge for limited attention,especially for the female in Chin...[Objectives]Metabolic obese normal weight(MONW)is becoming one of the pubic problems which are threatening human health.Whereas,MONW was facing a great challenge for limited attention,especially for the female in China.The aim of this research was to estimate the prevalence of MONW and its related risk components in South China.[Methods]A community-based cross-sectional study was performed on 3349 residents aged 18-93 years in The First Affiliated Hospital of Jinan University,Guangzhou,China,in 2019.Data was collected by physical examination data which included physical measurements and laboratory examinations.[Results]In all subjects,55%were females(M/F=1509/1840).The prevalence of MONW was 16.09%(0.04%for male,16.05%for female,P<0.001).The prevalence increased significantly with increasing age in both genders(P<0.001).The binary logistic regression analysis shows that among the risk factors with MONW,age,BMI,gender,systolic pressure,hypertension[Male:ORs=2.56,95%CI(1.23,5.32);Female:ORs=2.88,95%CI(1.76,4.71)]and hypertriglyceridemia[Male:ORs=3.23,95%CI(1.67,6.19);Female:ORs=2.57,95%CI(1.64,4.03)]were found to be statistically significant.The level of ALT in MONW group was(27.88±15.85)in male and(24.33±15.75)in female,which were significantly higher than those in the non-MetS group.[Conclusions]The prevalence of MONW was pretty high.We considered MONW be significantly associated with the increase of ALT.Female gender,advanced age,and elevated ALT were independent risk factors for MONW.It was high time that the government should raise the public attention toward metabolic function in normal weight population.Effective prevention and treatment strategies for MONW and its risk factors should be developed targeting different ages and genders.展开更多
Objective:To investigate the relationship between occupational X-ray exposure and cancer risk in medical X-ray diagnostic workers,a cohort study was conducted in medical X-ray diagnostic workers in Jiangsu province,Ch...Objective:To investigate the relationship between occupational X-ray exposure and cancer risk in medical X-ray diagnostic workers,a cohort study was conducted in medical X-ray diagnostic workers in Jiangsu province,China,based on Chinese Medical X-ray Workers Cohort,in order to provide scientific evidence for the improvement of occupational radiation protection in medical X-ray diagnostic workers.Methods:From 2011 to 2021,a retrospective cohort study was conducted in 2,984 medical X-ray diagnostic workers who worked in the radiology departments of all hospitals in Jiangsu during 1950–1980 and were alive by June 30,2011(radiation group)and 2,601 medical workers who worked in other departments of the same hospitals during the same period and were alive by June 30,2011(control group).Basic information and cancer incidence were collected from the study participants.The person-years of observation in the study participants during 2011–2021 was calculated.Cox regression model was used to calculate the relative risk for cancers such as solid cancer,lung cancer,and lymphomas in the radiation group after adjustment for sex,age,year of birth,and year to start working,and stratified analyses on the risks for total cancer and solid cancer in the radiation group were performed for confounders such as sex.Results:The total number of person-years of follow-up was 52,327,and the loss to follow-up rate was 3.15%.A total of 544 cancer cases were detected in follow-up during this period.Compared with the control group,the hazard ratio(HR)of total cancer was 1.13(95%CI:0.93–1.37),and the HR of solid cancer was 1.11(95%CI:0.91–1.36)in the radiation group.Compared with the control group,the radiation group had significantly higher risk for lymphoma(HR?10.36,95%CI:1.27–84.27).Stratified analyses showed that the medical X-ray workers who started to working before 1970 had higher risks for solid cancer(HR?1.26,95%CI:1.01–1.59)and total cancer(HR?1.29,95%CI:1.04–1.62)compared with those who started working after 1970.Conclusion:The risk for lymphoma was high in the medical X-ray workers in Jiangsu,suggesting that it is necessaryt to strengthen the occupational radiation protection for medical X-ray workers.展开更多
Stroke patients often experience motor deficits and cognitive problems after a stroke. Objective: To improve our understanding of the cognitive consequences of stroke. Method: a descriptive and analytical cross-sectio...Stroke patients often experience motor deficits and cognitive problems after a stroke. Objective: To improve our understanding of the cognitive consequences of stroke. Method: a descriptive and analytical cross-sectional study was conducted over 12-month period in the neurology departments of the Cocody and Treichville Hospitals in Côte d’Ivoire. Results: Out of 724 patients admitted to the neurology department, 415 (57.32%) were stroke patients, of which 145 (34.94%) were screened. The frequency of global cognitive functioning impairment was 86.21%, significantly higher than the frequency of patients without impairment, which was 13.79%. The study focused on detailing the cognitive status of stroke patients in neurology departments, assessing several cognitive functions during the subacute phase of stroke. These functions included global cognitive functioning, executive functions, language and memory. The frequency of post-stroke cognitive impairment is high among stroke patients in Abidjan. This frequency is comparable to figures found in Subsaharian stroke populations. Demographic and clinical characteristics studied included age, gender, education level, employment status, vascular diseases and cerebral affected area. Among these characteristics, only the education level and the cerebral affected area have been found significant. Conclusion: The incidence of cognitive impairment after a stroke is significantly high among stroke patients in Abidjan.展开更多
Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing s...Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it （P〈0.01）. Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their cumulative silica exposure （OR-3.00, 95% CI 2.34-3.83）. Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m^3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m^3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m^3 for those with 20 years of employment, or below 0.1 mg/m^3 for those with 30 or 40 years of silica exposure. Conclusions At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthend.展开更多
Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedest...Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedestrians. A pedestrian safety analysis of the common right-turn mode at four-phase signalized intersections is presented. Relative risk is used as a measure of the effect of behaviors. The analysis mainly includes five pedestrian factors that affect the conflict process between pedestrians and right-turning vehicles. Pedestrians tend to have a higher risk of being involved in conflicts in the following six situations: crossing with others, running over the crossing, entering the intersection, being near the exit lane, crossing in the middle or at the end of a green light when the right-turn lane is shared, crossing at the beginning of a green light or red period when the right-turn lane is exclusive. It is easier for pedestrians to get priority when crossing the street in the following situations: running over a crossing, entering the intersection, being near the entrance lane, and not using the crosswalk. However, pedestrians are more inclined to yield to right-turning vehicles when pedestrians are crossing in the middle of the green light time. Some measures to alleviate the conflict are put forward according to the conclusion. Video observations also indicate that a clear pedestrian waiting area must be marked for both pedestrian safety and right-turning vehicle efficiency at major flat intersections, particularly when the arms cover the lateral dividing strips.展开更多
Owing to information asymmetry,evaluating the credit risk of small-and mediumsized enterprises(SMEs)is difficult.While previous studies evaluating the credit risk of SMEs have mostly focused on intrinsic risk generate...Owing to information asymmetry,evaluating the credit risk of small-and mediumsized enterprises(SMEs)is difficult.While previous studies evaluating the credit risk of SMEs have mostly focused on intrinsic risk generated by SMEs,our study considers both intrinsic and relational risks generated by neighbor firms’publicly available risk events.We propose a framework for quantifying relational risk based on publicly available risk events for SMEs’credit risk evaluation.Our proposed framework quantifies relational risk by weighting the impact of publicly available risk events of each firm in an interfirm network—considering the impact of interfirm network type,risk event type,and time dependence of risk events—and combines the relational risk score with financial and demographic features to evaluate SMEs credit risk.Our results reveal that relational risk score significantly improves both discrimination and granting performances of credit risk evaluation of SMEs,providing valuable managerial and practical implications for financial institutions.展开更多
文摘This paper identifies the shortcomings of variance and semi-variance methods in investment risk measurement and introduces a new model,namely RR-ER (relative risk and excess revenue) model,which takes account of the revenue over expectation problem.Properties of RR-ER model and the consistency between RR-ER model and traditional risk measure model with regard to continuous random variables are discussed.Case analysis is presented to prove the practicality and efficiency of this new method.
文摘In this article, the lifetime data subjecting to right random censoring is considered. Nonparametric estimation of the distribution function based on the conception of presmoothed estimation of relative-risk function and the properties of the estimator by using methods of numerical modeling are discussed. In the model under consideration, the estimates were compared using numerical methods to determine which of the estimates is actually better.
基金supported by the National Natural Science Foundation of China(52004014)the Fundamental Research Funds for the Central Universities(ZY2406)the National Key Research&Development Program of China(2021YFB3301100).
文摘Refined risk prediction must be achieved to guarantee the safe and steady operation of chemical production processes.However,there is high nonlinearity and association coupling among massive,complicated multisource process data,resulting in a low accuracy of existing prediction technology.For that reason,a real-time risk prediction method for chemical processes based on the attention-based bidirectional long short-term memory(Attention-based Bi-LSTM)is proposed in this study.First,multisource process data,such as temperature,pressure,flow rate,and liquid level,are preprocessed for denoising.Data correlation is analyzed in time windows by setting time windows and moving step lengths to explore correlations,thus establishing a complex network model oriented to the chemical production process.Second,network structure entropy is introduced to reduce the dimensions of the multisource process data.Moreover,a 1D relative risk sequence is acquired by maxemin deviation standardization to judge whether the chemical process is in a steady state.Finally,an Attention-based Bi-LSTM algorithm is established by integrating the attention mechanism and the Bi-LSTM network to fit and train 1D relative risk sequences.In that way,the proposed algorithm achieves real-time prediction and intelligent perception of risk states during chemical production.A case study based on the Tennessee Eastman process(TEP)is conducted.The validity and reasonability of the proposed method are verified by analyzing distribution laws of relative risks under normal and fault conditions.Also,the proposed algorithm importantly improves the prediction accuracy of chemical process risks relative to that of existing prediction technologies.
基金supported by grants from National Natural Science Foundation of China(Grant Nos.81974422,81772824,and 81802635)。
文摘Objective:The spectrum and risk of cancer in relatives of BRCA1/2 pathogenic variant carriers in the Chinese population have not been established.Methods:A family history of cancer in 9903 unselected breast cancer patients was retrospectively analyzed.BRCA1/2 status was determined for all patients and relative risks(RRs)were calculated to evaluate cancer risk in relatives of the patients.Results:The incidences of breast cancer in female relatives of BRCA1 carriers,BRCA2 carriers,and non-carriers were 33.0%,32.2%,and 7.7%,respectively.The corresponding incidences of ovarian cancer were 11.5%,2.4%,and 0.5%,respectively.The incidences of pancreatic cancer in male relatives of BRCA1 carriers,BRCA2 carriers,and non-carriers were 1.4%,2.7%,and 0.6%,respectively.The corresponding incidences of prostate cancer were 1.0%,2.1%,and 0.4%,respectively.The risks of breast and ovarian cancers in female relatives of BRCA1 and BRCA2 carriers were significantly higher than female relatives of non-carriers(BRCA1:RR=4.29,P<0.001 and RR=21.95,P<0.001;BRCA2:RR=4.19,P<0.001 and RR=4.65,P<0.001,respectively).Additionally,higher risks of pancreatic and prostate cancers were noted in male relatives of BRCA2 carriers than non-carriers(RR=4.34,P=0.001 and RR=4.86,P=0.001,respectively).Conclusions:Female relatives of BRCA1 and BRCA2 carriers are at increased risk for breast and ovarian cancers,and male relatives of BRCA2 carriers are at increased risk for pancreatic and prostate cancers.
基金This study was funded by Ministry of Health of Science and Technology (2001 DEA 30035,2002D2A40022,2003DIA6N008), China.
文摘Objective To estimate the relative risks of dyslipidemia, hypertension, diabetes mellitus, and metabolic syndromes among overweight and obese Chinese children compared with their normal weight counterparts. Methods Overweight and obesity were defined by age- and sex-specific BMI classification reference for Chinese children and adolescents. Pediatric metabolic syndrome （MetS） and each risk factor for MetS were defined using the criteria for US adolescents. Definition of hyper-TC, LDL, and dyslipidemia for adults was applied as well. General linear model factor analysis and chi-square test were used to compare the difference in metabolic indicators among normal weight, overweight, and obese groups. Multiple logistic regression analysis was performed to estimate the odds ratio of metabolic abnormalities between obesity, overweight, and normal weight children, after adjustment for living area, family economic level, age, sex, and daily exercise time and TV watching time, as well as different dietary indices in the model. Results Significant increases in blood lipids, glucose, and blood pressure were found among overweight and obese children as compared with their counterparts with normal weight. By applying WGOC-recommended BMI classification, the risks for hypertriglyceridemia, low HDL and dyslipidemia among overweight children were 1.9, 1.4, and 1.5 times, and was 3.3, 1.5, and 1.8 times among obese groups compared to their counterparts with normal weight after adjustment for age, sex, region, socioeconomic status, physical activity, and dietary intakes. The overweight and obese children （15-17.9 years） had a high-risk of developing hypertension, which was 2.3 and 2.9 times higher than their counterparts with normal weight. Above 90% obese adolescents had abdominal obesity, while less than 1% normal weight ones had abdominal obesity. No obese adolescents were free from any risk factors for MetS, while 36.9% of normal weight adolescents were from the risk factors. 83.3% obese boys and all obese girls had metabolic syndrome, while only 15.5% normal weight boys and 18.8% normal weight girls had metabolic syndrome. Four risk factors for metabolic syndrome were found in 8.3% obese boys while none in normal weight boys and girls. The prevalence of MetS among normal weight, overweight, and obesity groups was 1.5%, 18.3%, and 38.1% respectively. Conclusion The cardiovascular disease （CVD） risk factors are clustered in obese Chinese children. Our observations strongly suggest that efforts should be made to prevent the onset of overweight and its associated diseases during early childhood.
基金(No. 2004C30067) supported by the Zhejiang Provincial Science and Technology Plan Project,China
文摘Objective:To assess whether people who ever use any form of chewing substance in Asia are at increased risk of cardiovascular disease(CVD).Methods:PubMed and ISI Web of Science were searched for relevant studies,with no limitation on language or study year.Studies were included if they provided quantitative estimate of the association between ever use of chewing substance and the occurrence of CVD.Two authors independently implemented inclusion criteria,abstracted study characteristics,and performed meta-analysis.Summary relative risks were estimated on the basis of a random effect model.We used Q statistic and Egger's test to examine heterogeneity across studies and potential publication bias,respectively.Results:Eight eligible studies were included.The relative risk of CVD for ever using chewing substances with or without tobacco was 1.26(95% confidence interval(CI) 1.12-1.40),which was unchanged when restricted to cohort studies [1.25(1.08-1.42)] or cohort studies in Taiwan [1.31(1.12-1.51)].The summary relative risk for ischemic heart disease was 1.27(1.02-1.52),and was lowered to 1.26(0.85-1.67) after exclusion of a cross-sectional study.The overall relative risk for cerebrovascular disease was 1.32(1.08-1.56).On the basis of the Taiwan data,the summary relative risk of CVD for betel(Areca catechu) chewing was 1.30(1.17-1.44).Data on dose-response were limited to betel chewing in Taiwan,suggesting a relationship between risk of CVD and cumulative exposure.Two large cohorts in Taiwan reported a greater risk of CVD with betel chewing than with smoking.Conclusions:An association was detected between betel chewing with or without tobacco and the risk of CVD.Betel chewing may impose a greater CVD risk than smoking.More effort is needed in developing betel chewing cessation programmes.The relationship between betel chewing and subgroups of CVD requires further investigation.
文摘There is evidence that a substantial part of genetic predisposition to prostate cancer （PCa） may be due to lower penetrance genes which are found by genome-wide association studies. We have recently conducted such a study and seven new regions of the genome linked to PCa risk have been identified. Three of these loci contain candidate susceptibility genes： MSMB, LMTK2 and KLK2/3. The MSMB and KLK2/3 genes may be useful for PCa screening, and the LMTK2 gene might provide a potential therapeutic target. Together with results from other groups, there are now 23 germline genetic variants which have been reported. These results have the potential to be developed into a genetic test. However, we consider that marketing of tests to the public is premature, as PCa risk can not be evaluated fully at this stage and the appropriate screening protocols need to be developed. Follow-up validation studies, as well as studies to explore the psychological implications of genetic profile testing, will be vital prior to roll out into healthcare.
文摘Using expectations regarding utilities to make decisions in a risk environment hides a paradox,which is called the expected utility enigma.Moreover,the mystery has not been solved yet;an imagined utility function on the risk-return plane has been applied to establish the mean-variance model,but this hypothetical utility function not only lacks foundation,it also holds an internal contradiction.This paper studies these basic problems.Through risk preference VNM condition is proposed to solve the expected utility enigma.How can a utility function satisfy the VNM condition?This is a basic problem that is hard to deal with.Fortunately,it is found in this paper that the VNM utility function can have some concrete forms when individuals have constant relative risk aversion.Furthermore,in order to explore the basis of mean-variance utility,an MV function is founded that is based on the VNM utility function and rooted in underlying investment activities.It is shown that the MV function is just the investor's utility function on the risk-return plane and that it has normal properties.Finally,the MV function is used to analyze the laws of investment activities in a systematic risk environment.In doing so,a tool,TRR,is used to measure risk aversion tendencies and to weigh risk and return.
基金Supported by Grant-in-Aid for the Third Term Comprehensive 10-year Strategy for Cancer Control,No.H20-3rd-002Grant-in-Aid for Cancer Research,Grant No.13-21-13-1 from the Japanese Ministry of Health,Labor and Welfare
文摘AIM: To quantitatively evaluate the impact of smoking on tooth loss.METHODS: We performed a Pub Med search to identify published articles that investigated the risk of tooth loss by smoking, from which RRs and their variance with characteristics of each study were extracted. The random-effects models were used to derive a pooled effect across studies. Potential sources of heterogeneity on the characteristics of the study and their influence on the pooled effect size were investigated using metaregression models. RESULTS: We identified 24 studies containing a total of 95973 participants for analysis. The pooled RR of ever-smokers compared with never- smokers was 1.73(95%CI: 1.60-1.86, P < 0.001). In meta-regression analysis, only the mean age of participants alone was identified as a statistically significant source of heterogeneity. The effect of smoking on tooth loss was stronger when the mean age of study participants was higher, indicating possible enhancement of tooth loss due to aging by smoking. RR was significantly lower in former smokers(1.49, 95%CI: 1.32-1.69, P < 0.001) than in current smokers(2.10, 95%CI: 1.87-2.35, P < 0.001), indicating the substantial benefit of smoking cessation for reducing the risk of tooth loss.CONCLUSION: Smoking is an independent risk factor for tooth loss regardless of many other confounders. Smoking cessation may attenuate this effect.
文摘Emerald ash borer (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae) is a phloem-feeding beetle native to Asia that is causing widespread mortality of ash trees in eastern North America. In this study, we quantify ash mortality risk associated with potential anthropogenic-induced introduction of Emerald Ash Borer (EAB) in North Dakota. The cohort model is calibrated with data from Ohio using weighting across factors—proximity to existing ash stands, campgrounds, roads and rails—to get a more accurate assessment of overall ash mortality risk. These factors are known to be associated with introduction of EAB to unaffected areas. Two protocols, a) “detection trees” and b) EAB traps are utilized to investigate EAB presence. Ash mortality risk maps such as the ones produced here may guide the placement of traps. Although North Dakota regions of high density ash tree stands are few, the resulting relative ash mortality risk map displays: a) very high risk areas around the Turtle Mountains and Theodore Roosevelt National Park and b) regions of high relative risk along the main riparian corridors. The applicability of risk maps such as the one developed may aid in assessing areas that may require significant monitoring.
基金supported by the CAMS Innovation Fund for Med-ical Science(2019-I2M-2-006 and 2021-I2M-1-042)the Fundamen-tal Research Funds for the Central Universities(3332021066 and 3332020104)+1 种基金the National Natural Science Foundation of China(81772243,81803172,81803167,31800703,31971168,81972976,31900891,32071241,32171239,and 82072331)the Natural Sci-ence Foundation of Tianjin(19JCYBJC26600 and 20JCQNJC00340).
文摘Background:It has been well-established that acute radiation exposures increase the risk of leukemia.However,it is still unknown whether these leukemia risk estimates could be extrapolated to occupational populations who receive repeated low-dose radiation exposure.The purpose of this study was to estimate quantified associations between low-dose radiation exposures and leukemia.Methods:The Chinese medical X-ray worker study(CMXW)included 27,011 medical X-ray workers employed at major hospitals in 24 provinces in China from 1950 to 1980,and a control population of 25,782 physicians matched by hospital,who were unexposed to X-ray equipment.Poisson regression models were used to esti-mate the excess relative risk(ERR)and excess absolute risk(EAR)for the incidence of leukemia associated with cumulative doses.A meta-analysis of the published literature on low-dose occupational radiation exposure and leukemia risk was also conducted.Results:The incidence rates of leukemia in X-ray workers and the control group were 6.70 and 3.39 per 100,000 person-years,respectively.Among X-ray workers,the average cumulative red bone marrow dose was 0.046 Gy.We found a positive relationship between 2-year lagged cumulative red bone marrow dose and risk of leukemia excluding chronic lymphocytic leukemia(CLL)(ERR=0.66 per 100 mGy,90%CI:0.09,1.53;EAR=0.29 per 104 PY-100 mGy,90%CI:0.07,0.56).The excess risk was largely driven by myeloid leukemia(ERR=1.06 per 100 mGy,90%CI:0.22,2.51).Based on the meta-analysis,the pooled ERR at 100 mGy was 0.19(95%CI:0.08,0.31).Conclusion:This study provides strong evidence of a positive and linear doseresponse relationship between cu-mulative red bone marrow dose and the incidence of non-CLL leukemia.
基金supported by the CAMS Innovation Fund for Medical Science[CIFMS,2018-I2M-1-001]the National Key R&D Program of China[2017YFC0702800]+1 种基金the National Natural Science Foundation of China[82070103]the Central Public-interest Scientific Institution Basal Research Fund[2016ZX310037]。
文摘Objective Airborne microbial communities include a significant number of uncultured and poorly characterized bacteria.No effective method currently exists to evaluate the health risks of such complex bacterial populations,particularly for pneumonia.Methods We developed a method to evaluate risks from airborne microorganisms,guided by the principle that closer evolutionary relationships reflect similar biological characteristics,and thus used16 S rDNA sequences of 10 common pneumonia-related bacterial pathogens.We calculated a risk of breath-related(Rbr)index of airborne bacterial communities and verified effectiveness with artificial flora and a clinical project.Results We suggested applying Rbr80 to evaluate the health risks of airborne bacterial communities that comprise 80% of dominant operational taxonomic units(OTUs).The feasibility of Rbr80 was confirmed by artificial flora and by pneumonia data from a hospital.A high Rbr80 value indicated a high risk of pneumonia from airborne bacterial communities.Conclusion Rbr80 is an effective index to evaluate the pneumonia-associated risk from airborne bacteria.Values of Rbr80 greater than 15.40 are considered high risk.
文摘Risk assessment and uncertainty approximation are two major and important parameters that need to be adopted for the development of pharmaceutical process to ensure reliable results.Additionally,there is a need to switch from the traditional method validation checklist to provide a high level of assurance of method reliability to measure quality attribute of a drug product.In the present work,evaluation of risk profile,combined standard uncertainty and expanded uncertainty in the analysis of acyclovir were studied.Uncertainty was calculated using cause-effect approach,and to make it more accurately applicable a method was validated in our laboratory as per the ICH guidelines.While assessing the results of validation,the calibration model was justified by the lack of fit and Levene＇s test.Risk profile represents the future applications of this method.In uncertainty the major contribution is due to sample concentration and mass.This work demonstrates the application of theoretical concepts of calibration model tests,relative bias,risk profile and uncertainty in routine methods used for analysis in pharmaceutical field.
基金Projects of Administration of Traditional Chinese Medicine of Guangdong Province of China(20182022,20182023,20191083)General Program of the National Natural Science Foundation of China(82074305)Laboratory Construction of Traditional Chinese Medicine of Guangdong Province of China(89017020).
文摘[Objectives]Metabolic obese normal weight(MONW)is becoming one of the pubic problems which are threatening human health.Whereas,MONW was facing a great challenge for limited attention,especially for the female in China.The aim of this research was to estimate the prevalence of MONW and its related risk components in South China.[Methods]A community-based cross-sectional study was performed on 3349 residents aged 18-93 years in The First Affiliated Hospital of Jinan University,Guangzhou,China,in 2019.Data was collected by physical examination data which included physical measurements and laboratory examinations.[Results]In all subjects,55%were females(M/F=1509/1840).The prevalence of MONW was 16.09%(0.04%for male,16.05%for female,P<0.001).The prevalence increased significantly with increasing age in both genders(P<0.001).The binary logistic regression analysis shows that among the risk factors with MONW,age,BMI,gender,systolic pressure,hypertension[Male:ORs=2.56,95%CI(1.23,5.32);Female:ORs=2.88,95%CI(1.76,4.71)]and hypertriglyceridemia[Male:ORs=3.23,95%CI(1.67,6.19);Female:ORs=2.57,95%CI(1.64,4.03)]were found to be statistically significant.The level of ALT in MONW group was(27.88±15.85)in male and(24.33±15.75)in female,which were significantly higher than those in the non-MetS group.[Conclusions]The prevalence of MONW was pretty high.We considered MONW be significantly associated with the increase of ALT.Female gender,advanced age,and elevated ALT were independent risk factors for MONW.It was high time that the government should raise the public attention toward metabolic function in normal weight population.Effective prevention and treatment strategies for MONW and its risk factors should be developed targeting different ages and genders.
基金supported by the CAMS Innovation Fund for Medical Science(2021-I2M-1–042)China and fund for the Key Medical Disciplines of Jiangsu Province(JSZJ20232201),China.
文摘Objective:To investigate the relationship between occupational X-ray exposure and cancer risk in medical X-ray diagnostic workers,a cohort study was conducted in medical X-ray diagnostic workers in Jiangsu province,China,based on Chinese Medical X-ray Workers Cohort,in order to provide scientific evidence for the improvement of occupational radiation protection in medical X-ray diagnostic workers.Methods:From 2011 to 2021,a retrospective cohort study was conducted in 2,984 medical X-ray diagnostic workers who worked in the radiology departments of all hospitals in Jiangsu during 1950–1980 and were alive by June 30,2011(radiation group)and 2,601 medical workers who worked in other departments of the same hospitals during the same period and were alive by June 30,2011(control group).Basic information and cancer incidence were collected from the study participants.The person-years of observation in the study participants during 2011–2021 was calculated.Cox regression model was used to calculate the relative risk for cancers such as solid cancer,lung cancer,and lymphomas in the radiation group after adjustment for sex,age,year of birth,and year to start working,and stratified analyses on the risks for total cancer and solid cancer in the radiation group were performed for confounders such as sex.Results:The total number of person-years of follow-up was 52,327,and the loss to follow-up rate was 3.15%.A total of 544 cancer cases were detected in follow-up during this period.Compared with the control group,the hazard ratio(HR)of total cancer was 1.13(95%CI:0.93–1.37),and the HR of solid cancer was 1.11(95%CI:0.91–1.36)in the radiation group.Compared with the control group,the radiation group had significantly higher risk for lymphoma(HR?10.36,95%CI:1.27–84.27).Stratified analyses showed that the medical X-ray workers who started to working before 1970 had higher risks for solid cancer(HR?1.26,95%CI:1.01–1.59)and total cancer(HR?1.29,95%CI:1.04–1.62)compared with those who started working after 1970.Conclusion:The risk for lymphoma was high in the medical X-ray workers in Jiangsu,suggesting that it is necessaryt to strengthen the occupational radiation protection for medical X-ray workers.
文摘Stroke patients often experience motor deficits and cognitive problems after a stroke. Objective: To improve our understanding of the cognitive consequences of stroke. Method: a descriptive and analytical cross-sectional study was conducted over 12-month period in the neurology departments of the Cocody and Treichville Hospitals in Côte d’Ivoire. Results: Out of 724 patients admitted to the neurology department, 415 (57.32%) were stroke patients, of which 145 (34.94%) were screened. The frequency of global cognitive functioning impairment was 86.21%, significantly higher than the frequency of patients without impairment, which was 13.79%. The study focused on detailing the cognitive status of stroke patients in neurology departments, assessing several cognitive functions during the subacute phase of stroke. These functions included global cognitive functioning, executive functions, language and memory. The frequency of post-stroke cognitive impairment is high among stroke patients in Abidjan. This frequency is comparable to figures found in Subsaharian stroke populations. Demographic and clinical characteristics studied included age, gender, education level, employment status, vascular diseases and cerebral affected area. Among these characteristics, only the education level and the cerebral affected area have been found significant. Conclusion: The incidence of cognitive impairment after a stroke is significantly high among stroke patients in Abidjan.
文摘Objectives The purposes were to determine the relationship between silicosis among foundry workers and their cumulative exposure to silica dust, and to establish a regression model to predict the risk for developing silicosis by a given length of employment and air concentrations of silica at worksites. Methods A 29-year cohort study was conducted, including all those employed for more than one year during January 1, 1980 to December 31, 1996 and all members of the cohort were followed-up to December 3 1, 2008. In total, 2 009 workers of an automobile foundry in Shiyan, Hubei province were recruited in the study, 1 300 at eight worksites including sand preparation, cast shakeout, and finishing, melting, moulding, core-making, overhead crane operation and pouring as exposed group, and the other 709 auxiliary workers at the same factory, such as electricians, inspectors, fitters, and so on, as control group. Person-years of observation were calculated by persons observed and years followed-up for each of them. Person-year incidence of silicosis and its relative risk （RR） or odds ratio （OR） and 95% confidence intervals （CI） among the workers were estimated, adjusted for relevant factors with logistic regression model using SPSS version 15.0 software. Results Totally, 2 009 workers were followed-up for 37 151 person-years and 48 cases of silicosis were found, with an overall incidence of 1.34 per thousand, 2.02 per thousand in exposed group, and 0.15 per thousand in control one. Risk of silicosis was significantly higher in the exposed group than that in the control one （RR=13.13, 95% CI 3.18-54.13）, higher in men than that in women （RR=13.92, 95% CI 1.92-100.93）. Risks of silicosis varied by job, highest in those exposed to cast shakeout and finishing （RR=28.14, 95% CI 6.43-123.11）, followed by those exposed to pouring （RR-22.23, 95% CI 5.01-98.55） in the foundry. Average length of employment at onset of silicosis was 25.94 years, and silicosis incidence increased with length of employment. Average age at onset of silicosis was 47.83 years old. The risk of silicosis in workers with pulmonary tuberculosis was 2.57 folds as those without it （P〈0.01）. Ten deaths were recorded in those with silicosis, with a case-fatality rate of 20.83 percent three of them died of lung cancer, three of liver cancer, two of ischemic heart disease, and two of other diseases as their immediate causes of death. Incidence of silicosis in foundry workers positively correlated with their cumulative silica exposure （OR-3.00, 95% CI 2.34-3.83）. Risks of silicosis increased by 4.38 folds with an increase of 1 mg/m^3-year of cumulative silica exposure, and by 3.79 folds with smoking, respectively, adjusted for alcohol drinking and age. Based on a logistic regression model fitted, incidence of silicosis is expected to be 44.6 per thousand for those with daily exposure to silica of 4.18 mg/m^3 in average for 30 years, and if incidence of silicosis is expected to be less than 1 per thousand, daily exposure to silica should be controlled below 0.2 mg/m^3 for those with 20 years of employment, or below 0.1 mg/m^3 for those with 30 or 40 years of silica exposure. Conclusions At present, foundry workers in China still face high risk of developing silicosis. For lowering occurrence of silicosis in exposed workers, it seems necessary that current occupational exposure limits for silica at worksites in China should be reexamined and silica dust control measures be strengthend.
基金The National Natural Science Foundation of China(No.51278220)
文摘Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedestrians. A pedestrian safety analysis of the common right-turn mode at four-phase signalized intersections is presented. Relative risk is used as a measure of the effect of behaviors. The analysis mainly includes five pedestrian factors that affect the conflict process between pedestrians and right-turning vehicles. Pedestrians tend to have a higher risk of being involved in conflicts in the following six situations: crossing with others, running over the crossing, entering the intersection, being near the exit lane, crossing in the middle or at the end of a green light when the right-turn lane is shared, crossing at the beginning of a green light or red period when the right-turn lane is exclusive. It is easier for pedestrians to get priority when crossing the street in the following situations: running over a crossing, entering the intersection, being near the entrance lane, and not using the crosswalk. However, pedestrians are more inclined to yield to right-turning vehicles when pedestrians are crossing in the middle of the green light time. Some measures to alleviate the conflict are put forward according to the conclusion. Video observations also indicate that a clear pedestrian waiting area must be marked for both pedestrian safety and right-turning vehicle efficiency at major flat intersections, particularly when the arms cover the lateral dividing strips.
基金the National Natural Science Foundation of China(Grant Nos.71731005,Nos.72101073)。
文摘Owing to information asymmetry,evaluating the credit risk of small-and mediumsized enterprises(SMEs)is difficult.While previous studies evaluating the credit risk of SMEs have mostly focused on intrinsic risk generated by SMEs,our study considers both intrinsic and relational risks generated by neighbor firms’publicly available risk events.We propose a framework for quantifying relational risk based on publicly available risk events for SMEs’credit risk evaluation.Our proposed framework quantifies relational risk by weighting the impact of publicly available risk events of each firm in an interfirm network—considering the impact of interfirm network type,risk event type,and time dependence of risk events—and combines the relational risk score with financial and demographic features to evaluate SMEs credit risk.Our results reveal that relational risk score significantly improves both discrimination and granting performances of credit risk evaluation of SMEs,providing valuable managerial and practical implications for financial institutions.
