Air samples were collected around industrial parks in Jiangsu, China, to allow the concentrations, profiles, and risk assessment of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polychlorinated naphthalenes (PCNs), and metals to be investigated. The concentrations of ΣPBDD/Fs and ΣPCNs were 1324.26–2080.98 fg/m3 (11.35–42.57 fg I-TEQ/m3) and 10,404.9–29,322.9 fg/m3 (1.32–7.19 fg I-TEQ/ m3), respectively. The highest concentration of ΣPBDD/Fs and ΣPCNs were observed at site C. PBDD/Fs were mainly dominated by PBDFs. The main contributor to the ΣPBDD/Fs in all samples was 1,2,3,4,6,7,8-HpBDF, which accounted for 25.75%–39.4%. For PCNs, the predominating homologues were tetra-, tri- and penta-CNs, which contributed 30.7%–43.3%, 24.7%–31.0%, and 10.6%–21.6%, respectively. As for metals, the pollution of As, Mn, Cr, and Ni in most samples exceeded National Ambient Air Quality Standards of China. Assessing the risk of inhalation exposure showed that there were potential carcinogenic risks to local residents.
本文以树脂铸型扫描电镜法,观察大鼠和小鼠肾上腺髓质的微血管构筑,并特别注意髓质血管和皮质血管的相互关系;此外切片观察测量了肾上腺髓质两种嗜铬细胞的分布。肾上腺皮质集合小静脉发出侧支,分布于髓质,构成了门静脉循环特点。小鼠的肾上腺髓质,主要由这种侧支供应;而大鼠的髓质,还有多支髓质动脉供应。从血管铸型上表现出的明显局部环形缩窄推测,肾上腺髓质血液循环有若干括约装置控制。大、小鼠两种嗜铬细胞在肾上腺髓质内的分布不同,大鼠的呈随机分布;小鼠的 NA 细胞多靠近皮质,而 A 细胞多远离皮质。 相似文献
We report the light and electron microscopic findings for two lesions from two patients who died of complications of familial adenomatous polyposis. In the first case microscopy of a small (100 to 200 mu), uniformly dark lesion (the commonest type seen in this condition) showed enlarged retinal pigment epithelial cells with an increased number of pigment granules. This is consistent with the term "hypertrophy of the retinal pigment epithelium", currently used to describe these lesions. In the second case we sectioned a larger (1000 to 1500 mu), oval, grey lesion from the posterior pole. The pigment epithelium was normal, but between it and outer retina was an unusual choristoma consisting largely of myelinated axons and astrocytes. 相似文献