Environmental Science and Pollution Research - The turning point of China’s total water consumption is very important for the understanding of the evolution trend of total water consumption... 相似文献
Fine particle matters (PM2.5) is a well-known risk factor for cardiovascular diseases. However, the underlying molecular mechanisms are largely unknown. Vascular hyper-reactivity plays an important roles in the pathogenesis of cardiovascular diseases. The present study was designed to investigate a hypothesis that PM2.5 up-regulated endothelin receptors in mesenteric artery and the potential underlying mechanisms. Rat mesenteric arteries were cultured with PM2.5. The artery contractile responses were recorded by a sensitive myograph. ETB and ETA receptor expressions of mRNA and protein were assessed by quantitative real-time PCR, Western blotting, and immunohistochemistry, respectively. Results showed that ETB receptor agonist, sarafotoxin 6c induced a negligible contraction in fresh artery segments, while ETA receptor agonist, ET-1 induced an obvious contraction. After organ culture, the contraction curve mediated by ETB and ETA receptors were shifted toward the left. PM2.5 1.0 μg/ml cultured for 16 h further enhanced ETB and ETA receptor-mediated contractile responses with a markedly increased maximal contraction. The organ culture enhanced ETB and ETA receptor mRNA and protein levels from fresh arteries, which were further increased by PM2.5. The U0126 (MEK/ERK1/2 inhibitor) and SB203580 (p38 inhibitor) significantly attenuated both organ cultured-induced and PM2.5-induced up-regulation of ETB receptor. U0126 also suppressed organ culture-increased and PM2.5-increased expressions of ETA receptor. SB203580 only suppressed PM2.5-induced enhanced expressions of ETA receptor In conclusion, airborne PM2.5 up-regulates ETB and ETA receptors of mesenteric artery via p38 MAPK and MEK/ERK1/2 MAPK pathways.
Environmental Science and Pollution Research - The mechanisms of abrupt seasonal temperature changes and warming (cooling) hiatuses remain unclear. Clarifying how they respond to various... 相似文献
Some conservation prioritization methods are based on the assumption that conservation needs overwhelm current resources and not all species can be conserved; therefore, a conservation triage scheme (i.e., when the system is overwhelmed, species should be divided into three groups based on likelihood of survival, and efforts should be focused on those species in the group with the best survival prospects and reduced or denied to those in the group with no survival prospects and to those in the group not needing special efforts for their conservation) is necessary to guide resource allocation. We argue that this decision-making strategy is not appropriate because resources are not as limited as often assumed, and it is not evident that there are species that cannot be conserved. Small population size alone, for example, does not doom a species to extinction; plants, reptiles, birds, and mammals offer examples. Although resources dedicated to conserving all threatened species are insufficient at present, the world's economic resources are vast, and greater resources could be dedicated toward species conservation. The political framework for species conservation has improved, with initiatives such as the UN Sustainable Development Goals and other international agreements, funding mechanisms such as The Global Environment Facility, and the rise of many nongovernmental organizations with nimble, rapid-response small grants programs. For a prioritization system to allow no extinctions, zero extinctions must be an explicit goal of the system. Extinction is not inevitable, and should not be acceptable. A goal of no human-induced extinctions is imperative given the irreversibility of species loss. 相似文献
Environmental Science and Pollution Research - The occurrence, distribution, sources, and ecological risks of organochlorine pesticides in Dongting Lake of China were investigated. The average... 相似文献
Environment, Development and Sustainability - The western region of China has always been the main battlefield for poverty alleviation. It is essential to explore the interaction mechanism between... 相似文献
In this report we have summarized our experience with the prenatal diagnosis of β-thalassemia in 1000 pregnancies followed at least until 12 months after birth. In the majority of these cases, the thalassemia lesion was the nonsense mutation at the codon corresponding to amino acid 39, which produces the hematological phenotype of β-thalassemia. Fetal blood sampling was carried out by placental aspiration, by which a sufficient amount of fetal blood for analysis was obtained in the majority of cases (99 per cent). The fetal mortality associated with fetal blood sampling was 6·3 per cent. Those placental samples contaminated by maternal cells were successfully purified by Ørskov lysis. Fetal blood was analysed by globin chain synthesis on CM–52 columns, which gave reliable results. Two misdiagnoses (0·2 per cent) have been made of which one was due to a non-globin protein co-migrating with the β-chains while the other resulted from a misclassification of the type of thalassemia segregating in the family. 相似文献