AimsRelatively little is known about the use of medication for the secondary prevention of cardiovascular disease (CVD) events in China, and the relevance to it of socioeconomic, lifestyle and health-related factors.Methods and resultsWe analysed cross-sectional data from the China Kadoorie Biobank (CKB) of 512,891 adults aged 30–79 years recruited from 1737 rural and urban communities in China. Information about doctor-diagnosed ischaemic heart disease (IHD) and stroke, and the use of medication for the secondary prevention of CVD events, were recorded by interview. Multivariate logistic regression was used to estimate odds ratios (ORs) for use of secondary preventive treatment, adjusting simultaneously for age, sex, area and education. Overall, 23,129 (4.5%) participants reported a history of CVD (3.0% IHD, 1.7% stroke). Among them, 35% reported current use of any of 6 classes of drug (anti-platelet, statins, diuretics, ACE-I, β-blockers or calcium-channel blockers) for the prevention of CVD events, with the rate of usage greater in those with older age, higher levels of income, education, BMI or blood pressure. The use of these agents was associated positively with history of diagnosed hypertension (OR 7.5; 95% confidence intervals: 7.08–8.06) and diabetes (1.40; 1.28–1.52) and inversely with self-rated health status, but there was no association with years since diagnosis.ConclusionsDespite recent improvements in hospital care in China, only one in three individuals with prior CVD was routinely treated with any proven secondary preventive drugs. The treatment rates were correlated with the existence of other risk factors, in particular evidence of hypertension.
Diglycidyl ethers of bisphenol-A (DGEBA)/methyl tetrahydrophthalic anhydride/polyethersulphone (PES) blends are prepared as matrix resins for thermally conductive composites using graphite nanoplatelets (GNPs) as the conductive component. The epoxy/PES blends form a network structure via reaction-induced phase separation (RIPS) during the curing process, and the GNPs are selectively localized in the PES phase and at the interface leading to a three-dimensional continuous filler network. With this unique structure, the thermal conductivity of the epoxy/PES/10 wt% GNPs composite is increased to 0.709 W m-1 K-1 , which is nearly 3.5 times that of the pure epoxy or a 52% increase compared to the epoxy/GNP composite without PES. In addition, it is found that the impact strength of the composite relative to the unfilled material is also improved.
Poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC)/mica composites with different amount of chain extender (CE) were melt compounded and then processed via two routes (compression molding and uniaxial stretching) into sheets and films. The tensile, thermal, and oxygen barrier properties of all the samples were investigated.Tensile test showed that the tensile strength and elongation at break of all films were much higher than that of all sheets, especially for PLA/PPC/mica with 0.9-wt% CE composite (CM 3 (CE) 0.9 ) film. The crystallinity of all films increased significantly after uniaxial stretching of sheet samples. The Fourier transform infrared spectroscopy (FTIR) results proved the chemical reactions occurred between PLA/PPC and CE.Scanning electron microscope (SEM) analysis revealed that compatibility and interfacial adhesion of all samples were improved after adding mica and CE, and they were further enhanced after uniaxial stretching. The addition of CE was not favorable to improve the oxygen barrier performance of PLA/PPC/mica sheet samples. However, the oxygen barrier performance of film samples was significantly improved after uniaxial stretching. In particular, the CM 3 (CE) 0.9 film had the lowest oxygen permeability coefficient (1.4 × 10 −15 cm 3 ·cm/(cm 2 ·s·Pa)), and this was the best oxygen barrier properties reported in the literature for PLA-based composites, which was comparable with PA film. This study demonstrated the high efficiency of uniaxial stretching on improvement of properties of composites, which would promote the application of biodegradable polymers in oxygen sensitive food packaging.
A series of latent curing agents were developed by replacing the hydrogen atom on secondary amine in imidazole with methoxy polyethylene glycol maleate diesters via Michael addition reaction. Methoxy polyethylene glycol maleate diesters with different molecular weight also restrained the reactivity of tertiary amine in imidazole ring. The curing properties and pot-life of the modified imidazole/epoxy systems were measured by differential scanning calorimeter and rotational rheometer. The modified imidazole/epoxy system could be cured quickly at 175 C. The modified imidazole shows good latency. After stored for more than 1 month, viscosity of modified imidazole/epoxy system remains unchanged. The longer chain polyether had the better thermal latency these curing agents had. Compared with unmodified imidazole, the novel latent curing agents led to better impact strength for cured epoxy. However, the compatibility between epoxy and latent curing agent will get worse if the molecular weight of polyether unite is over 750.
α, β-unsaturated diester was used to react with secondary amine in imidazole ring and also restrain its reactivity. The modified imidazole would thermally decompose into imidazole and unsaturated diesters. Mixture of the latent curing agent with epoxy resins has long storage stability at room temperature for more than one month. The curing behavior of modified imidazole/epoxy was investigated by nonisothermal differential scanning calorimetry method and the curing kinetics results revealed that the modified imidazole has higher curing temperature but similar apparent activation energy. Furthermore, the modified imidazole brings better impact strength for cured epoxy.
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