In order to evaluate the prevalence of childhood asthma, allergic diseases and pneumonia in Urumqi City, China, as well as its associations with housing and home characteristics, a cross-sectional study was performed in 4618 children (81.7% response rate, average age 4.7±0.9 year, boys accounting for 53.7%). Questions on children's asthma and allergic diseases were from the International Study on Asthma and Allergies in Childhood (ISAAC) and were integrated with questions on the home environment from the Dampness in Buildings and Health (DBH) study, slightly modified to account for Chinese building characteristics and life habits. The prevalences of physician diagnosed asthma, allergic rhinitis (AR) and pneumonia were 3.6%, 8.7% and 40.9%, respectively. One fourth of children reported wheezing and more than 40% AR symptoms in the last 12 months. Controlling for confounding factors, positive associations were found for home mold/dampness and wheezing (adjusted odds ratio, aOR 1.33, 95% CI 1.071.66), AR symptoms (1.34, 1.091.64) last 12 months and physician diagnosed pneumonia (1.33, 1.091.62). Floor material by wood, PVC or carpeting; and walls by wallpaper, painting or wood material, were positively associated with AR symptoms. Home environmental tobacco smoke (ETS) was positively associated with wheezing (1.23, 1.041.46) and pneumonia (1.25, 1.071.45). In conclusion, there was a relatively high prevalence of asthmatic and AR symptoms and diagnosed pneumonia in preschool children in Urumqi. Home signs of mold growth or dampness, windowpane condensation, as well as ETS and interior surface materials emitting chemicals were risk factors for allergic symptoms and pneumonia. childhood, dampness, indoor air quality, prevalence, environmental tobacco smoking
SummaryChina's mineral resource consumption has gone through multiple increases since 1980, resulting in the inadequacy of important strategic resources and a high level of external dependence. Some developed countries have already reduced primary resources consumption through urban mining. Can China also break through the bottleneck of the resource shortage and continue its economic and social development through strengthening of urban mining? This article selected copper (Cu), aluminum (Al), lead (Pb), and iron (Fe) as case studies and established predictive models for metal demand, recycling, and stock, based on stock analysis, material flow analysis, and a life distribution model, and then analyzed the metabolism of the four resources and compared the environmental effects of three scenarios. The study indicates that the urban mining potential of Cu, Fe, Al, and Pb will attain 8.1, 711.6, 37.0, and 12.1 million tonnes, respectively, in 2040. Compared with 2010, the substitution rate (secondary metals substituting primary metals) of Cu and Fe increase by 25.4% and 59.9%, whereas external dependence decreases by 30.8% and 25.7%. However, substitution is not obvious regarding Al and Pb. The low resource scenario decreases resources use, which will reduce external dependence in the short term, whereas the strengthened recovery scenario increases resource recovery and has a larger effect in reducing external dependence in the long term. So, in line with urban mining in the future, China should change its environment and resource strategy, further strengthen layout and construction of urban mining demonstration bases, and encourage the use of recyclable resources to provide a better foundation for urban mining. Keywords:industrial ecology life cycle metals recycling stock analysis urban mining Supporting information is available on the JIE Web site
This article provides preliminary validity evidence for the shorter Mandarin version of the Vocabulary Size Test (VST) under the content aspect, technical quality, substantive and generalizability aspect of Messick's (1995) construct validity framework. The shorter version with 177 Chinese university students in three proficiency levels indicates that the test enjoys a high level of validity both from the perspective of classical test theory and item response theory. A one-way ANOVA and detailed statistics of Rasch analyses demonstrate that the test could effectively distinguish learners from different proficiency levels. The first eight levels of the VST generally display an ascending difficulty continuum except that some loan words in the seventh and the eighth level prove to be problematic in assessing Chinese learners' vocabulary size accurately. The generalizability aspect of construct validity is demonstrated in that there is no item bias for learners of the same proficiency group in terms of gender. Compared with the results of other studies either on monolingual or bilingual version, this research attempts to justify the appropriateness of the Mandarin version and calls for cautious applications of the test instrument on Chinese learners.
In this paper, hydroxyapatite-carbon nanotube/titania (HA-CNT/TiO2) double layer coatings were successfully developed on titanium (Ti) substrates intended for biomedical applications. A TiO2 coating was firstly developed by anodization to improve bonding between HA and Ti, and then the layer of HA and CNTs was coated on the surface by the sol-gel process to improve the biocompatibility and mechanical properties of Ti. The surfaces of double layer coatings were uniform and crack-free with a thickness of about 7 μm. The bonding strength of the HA-CNT/TiO2 coating was higher than that of the pure HA and HA-CNT coatings. Additionally, in vitro cell experiments showed that CNTs promoted the adhesion of preosteoblasts on the HA-CNT/TiO2 double layer coatings. These unique surfaces combined with the osteoconductive properties of HA exhibited the excellent mechanical properties of CNTs. Therefore, the developed HA-CNT/TiO2 coatings on Ti substrates might be a promising material for bone replacement.
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