维生素D是人体生命中不可缺少的营养素,由于免疫细胞同样表达1α-羟化酶和维生素D受体(vitamin D receptor,VDR),所以维生素D是一种重要的免疫调节剂,它可以调节固有免疫和适应性免疫。维生素D通过与维生素D受体结合,激活和调节多种细...维生素D是人体生命中不可缺少的营养素,由于免疫细胞同样表达1α-羟化酶和维生素D受体(vitamin D receptor,VDR),所以维生素D是一种重要的免疫调节剂,它可以调节固有免疫和适应性免疫。维生素D通过与维生素D受体结合,激活和调节多种细胞通路来发挥其生物学效应。尤其是免疫细胞(抗原递呈细胞、B细胞、T细胞)能够表达1α-羟化酶从而合成维生素D的活性代谢物,更进一步证明了维生素D的免疫调节特性。维生素D缺乏会导致诸如自身免疫性疾病等异常反应。一些观察研究表明补充维生素D有利于降低疾病的严重程度。但是,用于预防或治疗自身免疫性疾病所需补充的血浆25-羟维生素D浓度标准仍有争议。本文将对维生素D免疫调节研究进展以及维生素D在自身免疫性内分泌疾病(自身免疫性甲状腺疾病、1型糖尿病、Addison’s病)发病机制中的作用进行综述。展开更多
Isolated Mn2O_(3) nanotubes and nanofibers were prepared very easily at a large scale with the liquid-phase catalysis method.The Mn2O_(3) nanotubes had dimensions of 30–50 nm(exterior diameter)and 0.2–1.0 mm(length)...Isolated Mn2O_(3) nanotubes and nanofibers were prepared very easily at a large scale with the liquid-phase catalysis method.The Mn2O_(3) nanotubes had dimensions of 30–50 nm(exterior diameter)and 0.2–1.0 mm(length),approximately.The Mn2O_(3) nanofibers had dimensions of 10–30 nm(diameter)and 0.4–2.0 mm(length),approxim-ately.Nano-Mn2O_(3) with different microstructures including nanotubes,nanofibers and nanoparticles could be selectively synthesized by controlling the contents and proportions of potassium permanganate and ferric nitrate.Ferric nitrate was an ideal catalyst for the preparation of Mn2O_(3) nanotube/fiber.When cobalt nitrate or nickel nitrate was used as catalyst,only amorphous nano-Mn2O_(3) was synthesized.X-ray diffraction(XRD)result shows that the Mn2O_(3) nanotube has a crystalline structure different from o-Mn2O_(3),t-Mn2O_(3),h-Mn2O_(3) and c-Mn2O_(3).展开更多
文摘维生素D是人体生命中不可缺少的营养素,由于免疫细胞同样表达1α-羟化酶和维生素D受体(vitamin D receptor,VDR),所以维生素D是一种重要的免疫调节剂,它可以调节固有免疫和适应性免疫。维生素D通过与维生素D受体结合,激活和调节多种细胞通路来发挥其生物学效应。尤其是免疫细胞(抗原递呈细胞、B细胞、T细胞)能够表达1α-羟化酶从而合成维生素D的活性代谢物,更进一步证明了维生素D的免疫调节特性。维生素D缺乏会导致诸如自身免疫性疾病等异常反应。一些观察研究表明补充维生素D有利于降低疾病的严重程度。但是,用于预防或治疗自身免疫性疾病所需补充的血浆25-羟维生素D浓度标准仍有争议。本文将对维生素D免疫调节研究进展以及维生素D在自身免疫性内分泌疾病(自身免疫性甲状腺疾病、1型糖尿病、Addison’s病)发病机制中的作用进行综述。
文摘Isolated Mn2O_(3) nanotubes and nanofibers were prepared very easily at a large scale with the liquid-phase catalysis method.The Mn2O_(3) nanotubes had dimensions of 30–50 nm(exterior diameter)and 0.2–1.0 mm(length),approximately.The Mn2O_(3) nanofibers had dimensions of 10–30 nm(diameter)and 0.4–2.0 mm(length),approxim-ately.Nano-Mn2O_(3) with different microstructures including nanotubes,nanofibers and nanoparticles could be selectively synthesized by controlling the contents and proportions of potassium permanganate and ferric nitrate.Ferric nitrate was an ideal catalyst for the preparation of Mn2O_(3) nanotube/fiber.When cobalt nitrate or nickel nitrate was used as catalyst,only amorphous nano-Mn2O_(3) was synthesized.X-ray diffraction(XRD)result shows that the Mn2O_(3) nanotube has a crystalline structure different from o-Mn2O_(3),t-Mn2O_(3),h-Mn2O_(3) and c-Mn2O_(3).
