Risk assessment of metal(loid)s in tea from seven producing provinces in China.

To evaluate metal(loid) contamination in tea leaves and assess health risks of tea drinking in China, metal(loid) concentrations in tea leaves from major tea-producing provinces were determined. Nine metal(loid)s (Al, Cr, Co, Ni, Cu, Zn, As, Cd and Pb) were measured in a total of 217 tea samples representing five tea varieties (black tea, dark tea, green tea, oolong tea and white tea) from seven major tea-producing provinces of China (Fujian, Guangdong, Henan, Hunan, Jiangsu, Yunnan and Zhejiang). The results indicated that tea samples from Hunan Province had the highest metal(loid) concentrations, likely due its high prevalence of heavy industrial activities and soil pollution. The concentrations of As and Pb in dark tea were markedly higher than those in other tea varieties. A strong Spearman correlation coefficient (0.78, P < 0.001) of As and Pb in all the tea varieties has also been found, indicating their similar sources. Human health risk assessment for the nine analyzed metal(loid)s indicated that co-exposure to these metal(loids) may not cause significant health risks (hazard index [HI] > 1 suggests considerable health risks). Among the five tea varieties, metal(loids)s in dark and green tea induced relatively higher health risks, with 90th percentile HI values approached 0.8. Co (53.6 %-84.5 %) and Al (3.33 %-15.8 %) made the highest contributions to the HI of the selected tea commodities. Thus, public and regulatory agencies should reduce excessive Co and Al accumulation in these tea varieties during cultivation and production processes.

Organophosphate ester exposure among Chinese waste incinerator workers: Urinary levels, risk assessment and associations with oxidative stress.

Organophosphate esters (OPEs), which are frequently used as flame retardants and plasticizers in versatile products, are readily released to the external environment. Although workers at municipal waste incineration plants may be extensively exposed to OPEs, only scarce health monitoring and risk assessments have been conducted in this population. In this study, we investigated the levels of eight metabolites of organophosphate esters (mOPEs) and the oxidative stress marker 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine samples from 73 waste incinerator workers and 97 general residents from Shenzhen, China between September 2016 and June 2017. The overall detection rate of mOPEs was 82.2 %-100 %, and higher concentrations of di-p-cresyl phosphate and chlorinated mOPEs [bis(2-chloroethyl) phosphate (BCEP), bis(1-chloro-2propyl) phosphate (BCIPP), bis(1,3-dichloro-2-propyl) phosphate) (BDCIPP)] were found among incinerator workers than among general residents. The incinerator workers also showed significantly higher levels of 8-OHdG than general residents, but the measured levels of most mOPEs were not significantly correlated with the level of 8-OHdG; this may be because co-exposure to multiple toxic compounds can lead to oxidative stress. Risk assessment using Monte Carlo simulations revealed that 95 % of the incinerator workers were free from non-carcinogenic effects due to OPEs exposure (hazard index = 0.27, 95 % CI: 0.09, 0.77). However, the carcinogenic risk of tris(2-chloroethyl) phosphate (TCEP) for incinerator workers was between 10-6 and 10-4. These results indicate that incinerator workers are extensively exposed to OPEs, and better protective measures need to be implemented.

A nationwide investigation of perchlorate levels in staple foods from China: Implications for human exposure and risk assessment.

Perchlorate is an emerging pollutant and thyroid toxicant frequently occurred in air, water, soil and various foodstuffs. Rice and wheat flour are the most common staple foods, which could accumulate perchlorate from contaminated soils and irrigation water. However, human exposure to perchlorate via rice and wheat flour consumption has only been investigated to a limited extent. Therefore, we collected 207 rice samples and 189 wheat flour samples from 19 provinces in China to assess the level of perchlorate. The levels of perchlorate in rice and wheat flour ranged from not detected (N.D.) to 28.7 ng/g and less than limits of quantification (

Effects of cost-benefit analysis under back propagation neural network on financial benefit evaluation of investment projects.

To determine the influence of the weight of the economic effectiveness evaluation criteria of the major investments of listed enterprises, and provide new management ideas for the development of the follow-up enterprises, firstly, the financial benefit evaluation system of investment projects is analyzed and constructed, and the specific evaluation process is analyzed. Then, on this basis, the evaluation index is refined; the basic structure of BP neural network (BPNN) is introduced, and genetic algorithm is used to improve BP neural network. The cost-benefit analysis model is constructed based on the improved BPNN. The listed company A is taken as an example to analyze its development data in recent years, and then the data of 10 listed companies are taken as the research object. Matlab simulation software is used to train and verify the improved BPNN model, analyze and predict the weight value of the financial benefit index of the investment projects of these 10 companies, and then determine the index to improve the financial benefit of the investment projects. Under the analysis of the development data of listed company A in the past 10 years, it is found that the indicators of the listed company's profitability per share, debt risk operation ability, development, and growth ability in the past 10 years are in relatively stable state. The principal component analysis of its 20 secondary sub-indexes is conducted based on the four primary indicators: profitability, debt risk, operational capacity, and development and growth. A total of eight principal components including return on equity (ROE), return on assets (ROA), (total asset turnover) TATO, turnover of account receivable (AR), asset-liability ratio, interest protection multiple, income growth rate, and year-on-year rate of increase for complete assets are extracted. The average error between the final output value, the actual value, and the expected value is 0.0304 and 0.0169, respectively. The weight coefficient of the monetary benefits evaluation indicator of investment items is calculated, and the computed results show that year-on-year rate of increase for complete assets, TOTA, ROA, turnover of total capital, and ROE are important indexes in the financial benefit evaluation of investment projects. It indicates that to improve the financial benefit of investment projects of listed enterprises, it is necessary to enhance the year-over-year growth degree of total properties and ROA.

Large Disparity between Prevalence and Treatment Rates for Hepatitis C in Western China.

Background and Aims: Recently, the World Health Organization adopted the first-ever global hepatitis strategy with the dream of eliminating viral hepatitis as a public health threat by 2030. However, the epidemiology and treatment rates of hepatitis C virus (HCV) infection in Western China are still unknown. Methods: A total of 111,916 adult individuals (15-96 years) who underwent the HCV-antibody (HCV-Ab) test in the Second Affiliated Hospital of Chongqing Medical University between 2013 and 2015 were included in this study. We retrospectively analyzed the electronic medical records' data for each, and the positivity of HCV-Ab and the treatment of HCV RNA-positive patients were evaluated. Results: During 2013-2015, the crude prevalence of HCV-Ab was 1.4% (95%CI: 1.4-1.5; 1,611/111,916) and the adjusted prevalence of HCV-Ab was 1.7% (95%CI: 1.6-1.8), which was higher than in the 2006 national study (0.43%). The prevalence was 2-times higher in males than females (2.0% vs. 1.1%, p < 0.01). Notably, only 46% (434/951) of the HCV RNA-positive patients received standard peg-interferon plus ribavirin treatment, with 370 (82%) that completed treatment, of whom 272 (74%) achieved sustained virologic response (SVR). Particularly, 11% (32/292) of HCV RNA-positive patients were HBsAg-positive, and the SVR rate for them was lower than for the HBsAg-negative patients, but no significant difference was observed. Conclusions: HCV infection may have increased since 2006 in Western China. The SVR rate of peg-interferon plus ribavirin treatment was high, but the proportion of untreated HCV patients was large. Thus, more efforts need to be made by the government to create a scientific-based policy for HCV treatment and prevention.

Validation of a venous thromboembolism risk assessment model in hospitalized chinese patients: a case-control study.

AIM: The appropriate selection of hospitalized patients for venous thromboembolism(VTE) prophylaxis is an important unresolved issue. We sought to validate the Caprini model, a famous individual VTE risk assessment model(RAM), in hospitalized Chinese patients. METHODS: We performed a retrospective case-control study among unselected hospitalized patients admitted to a comprehensive hospital in China. A total of 347 patients were confirmed to have VTE during hospitalization, and 651 controls were randomly selected to match the patients according to medical service. Both the patients and controls were retrospectively assessed for the risk of VTE using the Caprini RAM. RESULTS: The average Caprini cumulative risk score in the patients was significantly higher than that observed in the controls(4.69±2.58 vs 3.16±1.82, p＜0.0001). Compared with that observed in the low-risk group, a classification of high-risk according to the Caprini model was associated with a 1.65-fold increased risk of VTE(95%CI 1.05-2.61), while that of highest-risk was associated with a 4.84-fold increased risk of VTE(95%CI 3.06-7.64). After further stratifying the highest risk level with a cumulative risk score of ≥5 into scores of 5-6, 7-8 and ≥9, the patients with a score of 5-6 were found to exhibit a 3.33-fold increased risk of VTE(95%CI 2.06-5.40), those with a score 7-8 exhibited a 9.41-fold increased risk of VTE(95%CI 4.90-18.08) and those with a score of ≥9 exhibited a 24.69-fold(95%CI 7.98-76.40) increased risk of VTE compared with their low-risk counterparts. CONCLUSIONS: Our study suggests that the Caprini RAM can be used to effectively stratify hospitalized Chinese patients into VTE risk categories based on individual risk factors. The classification of the highest risk level with a cumulative risk score of ≥5 provided significantly more clinical information, and further stratification of this group of patients is needed.

Facile and rapid magnetic relaxation switch immunosensor for endocrine-disrupting chemicals.

In order to develop facile, fast and sensitive detection methods for endocrine-disrupting chemicals (EDCs), we described a sensitive biosensing system involving magnetic relaxation switch, based on the assembly of cross-linked superparamagnetic iron oxide (CLIO) nanoparticles induced by the antigen-antibody biorecognition. The design of smart CLIO-based superparamagnetic iron oxide nanoparticles and antigen-OVA was described for the detection of bisphenol A [2,2-bis (4-hydroxyphenol) propane (BPA)]. The addition of BPA to the rapid magnetic relaxation switch immunosensor led to transverse relaxation time (T2) shortening compared to a blank control as shown by NMR relaxometry measurements. This process was also applied to the rapid and facile determination of concentrations of BPA in drinking water (tap water). Good linearity for all calibration curves was obtained, and the limit of detection (LOD) for BPA was 0.4 ng/mL in tap water.

p-Value simulation for affected sib pair multiple testing.

A standard approach to calculation of critical values for affected sib pair multiple testing is based on: (a) fully informative markers, (b) Haldane map function assumptions leading to a Markov chain model for inheritance vectors, (c) central limit approximation to averages of sampled inheritance vectors leading to an Ornstein-Uhlenbeck process approximation, and (d) simple approximations to the maximum of such a process. Under these assumptions, assuming equispaced or close to equispaced markers, if the sample size is large, an approximation is available that is easy to calculate and performs well. However, for small sample sizes, a large number of markers, and for small p-values, there is good reason to be cautious about the use of the Gaussian approximation. We develop an algorithm for calculation of multiple testing p-values based on the standard Markov chain model, avoiding the use of Gaussian (large sample) approximation. We illustrate the use of this algorithm by demonstrating some inadequacies of the Gaussian approximation.