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1.
N Engl J Med ; 382(13): 1199-1207, 2020 03 26.
Article in English | MEDLINE | ID: mdl-31995857

ABSTRACT

BACKGROUND: The initial cases of novel coronavirus (2019-nCoV)-infected pneumonia (NCIP) occurred in Wuhan, Hubei Province, China, in December 2019 and January 2020. We analyzed data on the first 425 confirmed cases in Wuhan to determine the epidemiologic characteristics of NCIP. METHODS: We collected information on demographic characteristics, exposure history, and illness timelines of laboratory-confirmed cases of NCIP that had been reported by January 22, 2020. We described characteristics of the cases and estimated the key epidemiologic time-delay distributions. In the early period of exponential growth, we estimated the epidemic doubling time and the basic reproductive number. RESULTS: Among the first 425 patients with confirmed NCIP, the median age was 59 years and 56% were male. The majority of cases (55%) with onset before January 1, 2020, were linked to the Huanan Seafood Wholesale Market, as compared with 8.6% of the subsequent cases. The mean incubation period was 5.2 days (95% confidence interval [CI], 4.1 to 7.0), with the 95th percentile of the distribution at 12.5 days. In its early stages, the epidemic doubled in size every 7.4 days. With a mean serial interval of 7.5 days (95% CI, 5.3 to 19), the basic reproductive number was estimated to be 2.2 (95% CI, 1.4 to 3.9). CONCLUSIONS: On the basis of this information, there is evidence that human-to-human transmission has occurred among close contacts since the middle of December 2019. Considerable efforts to reduce transmission will be required to control outbreaks if similar dynamics apply elsewhere. Measures to prevent or reduce transmission should be implemented in populations at risk. (Funded by the Ministry of Science and Technology of China and others.).


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Disease Transmission, Infectious/statistics & numerical data , Epidemics , Infectious Disease Incubation Period , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , Adolescent , Adult , Aged , Betacoronavirus/genetics , COVID-19 , China/epidemiology , Communicable Disease Control/methods , Coronavirus Infections/virology , Disease Transmission, Infectious/prevention & control , Epidemics/prevention & control , Female , Humans , Incidence , Male , Middle Aged , Pandemics , Pneumonia, Viral/virology , Polymerase Chain Reaction , SARS-CoV-2 , Young Adult
2.
Environ Sci Pollut Res Int ; 31(20): 29836-29858, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38592627

ABSTRACT

Indirect carbonation of steel slag is an effective method for CO2 storage, reducing emissions, and promoting cleaner production in the steel industry. However, challenges remain, such as low Ca2+ leaching rates and slag management complexities arising from variations in mineral compositions. To address this, a high-temperature modification process is proposed to alter the mineral composition and facilitate the synergistic utilization of calcium and iron. This study delves into the effects of various solid waste modifications on the leaching of Ca2+ and the total iron content within steel slag. Results show that high-basicity modified slag forms Ca2(Al, Fe)2O5, reducing calcium leaching. Low-alkalinity modified slag produces calcium-rich aluminum minerals and also reduces the leaching of Ca2+ ions. At a basicity of 2.5, coal gangue, fly ash, and blast slag achieve maximum Ca2+ leaching rates of 88.93%, 89.46%, and 90.17%, respectively, with corresponding total iron contents of 41.46%, 37.72%, and 35.29%. Upgraded coal gangue exhibits a 50.02% increase in calcium leaching and a 15.58% increase in total iron content compared to the original slag. This enhances CO2 fixation and iron resource utilization. Overall, the proposed indirect carbonation and iron enrichment modification offer a novel approach for the resource utilization and environmental stability of steel slag.


Subject(s)
Calcium , Solid Waste , Steel , Calcium/chemistry , Iron/chemistry , Hot Temperature
3.
Environ Sci Pollut Res Int ; 28(36): 49383-49409, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34331652

ABSTRACT

Mineral carbonation can simultaneously realize the effective treatment of CO2 and iron and steel slag; thus, it is of great significance for the low carbon and sustainable development of iron and steel industry. In this article, the researches of mineral carbonation process using iron and steel slag as feedstock are reviewed, and the carbonation reaction mechanism and the parameters affecting the reaction rate and carbonation degree are analyzed. Furthermore, the effect of different enforcement approaches, such as ultrasonic enhancement, mixed calcination, microbial enhancement, and cyclic coprocessing on mineral carbonation reaction, is introduced. The additional effects of mineral carbonation, such as solving the problem of poor volume stability of steel slag, weakening the leaching of heavy metal ions, and reducing the pH of the leachate, are also illustrated. Moreover, issues related to mineral carbonation technology that should be emphasized upon soon, such as the production of valuable products, use of industrial wastewater, aqueous phase recycling use, multiparameter coupling analysis, and research on the properties of carbonation residues, are also discussed, which contribute some perspectives to the future development of mineral carbonation of iron and steel slag.


Subject(s)
Carbon Dioxide , Steel , Industrial Waste/analysis , Iron , Minerals
4.
BMJ Open ; 9(6): e024831, 2019 06 28.
Article in English | MEDLINE | ID: mdl-31256019

ABSTRACT

OBJECTIVE: Our research aims to estimate the per capita cost of 13 items in the basic public health service (BPHS) project in Zhuhai, China, and provide an economical basis for the improvement of the cost compensation mechanism used by the government. DESIGN: This research is a cross-sectional study. SETTING: A total of 19 primary healthcare facilities (PHFs) in Zhuhai, China, are involved in this research. PARTICIPANTS: A total of 152 participants (114 personnel engaged in BPHS, 19 financial personnel and 19 PHF heads) were included in this study, which was conducted from May 2017 to July 2017. PRIMARY AND SECONDARY OUTCOME MEASURES: We used the activity-based costing model to calculate the cost of providing BPHS in Zhuhai. An analytical hierarchy process was used to determine the difficulty dimension and workload coefficient. RESULTS: The weights of the difficulty dimensions in the provision of BPHS in Zhuhai were 35.04% (coordination of residents), 24.03% (staff workload), 21.36% (complexity of work-related skills) and 19.59% (basic qualities of staff). The average difficulty coefficient of each subproject was 5.28. The actual per capita cost of BPHS provision in 2016 was 97.48 RMB (12.76 EUR), which was higher than the actual standard compensation of 55 RMB (7.2 EUR) in Zhuhai. Immunisation was the most costly among the 13 service items (17.82 RMB or 2.33 EUR per person), whereas the management of tuberculosis was the least costly item (0.57 RMB or 0.07 EUR per person). CONCLUSIONS: Government funds for basic public health services cannot compensate for the actual costs. Accordingly, subsidies should be increased based on the actual per capita cost for sustainable BPHS development. The government should improve the methods used in cost estimation and measures used as the basis for awarding performance incentives.


Subject(s)
Health Care Costs/statistics & numerical data , National Health Programs/economics , Public Health/economics , China , Costs and Cost Analysis , Cross-Sectional Studies , Humans , Surveys and Questionnaires
5.
Curr Med Sci ; 39(4): 663-669, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31347006

ABSTRACT

This study aimed to evaluate the satisfaction of village doctors to essential medicines list (EML) and accessibility of essential medicines (EMs) distribution to improve the implementation of EML in village clinics. A total of 422 village doctors from five counties in three provinces of China were surveyed by questionnaires. Logistic regression analysis was conducted to identify the main factors associated with village doctors' evaluation of EML. The results showed that village doctors had a negative evaluation in satisfaction level of EML to village-based care and accessibility of EM distribution. The government should adjust EML regularly based on the actual health status of local villagers in China and focus on adding appropriate drugs that meet the needs of villagers with chronic disease. The local government should also attach importance to the distribution of EMs and maintain their supply in village clinics.


Subject(s)
Patient Acceptance of Health Care , Physicians , China/epidemiology , Cross-Sectional Studies , Government , Humans , Surveys and Questionnaires
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