The notion of preordering, which is a generalization of the notion of ordering, has been introduced by Serre. On the other hand, the notion of round quadratic forms has been introduced by Witt. Based on these ideas, i...The notion of preordering, which is a generalization of the notion of ordering, has been introduced by Serre. On the other hand, the notion of round quadratic forms has been introduced by Witt. Based on these ideas, it is here shown that 1) a field F is formally real n-pythagorean iff the nth radical, RnF is a preordering (Theorem 2), and 2) a field F is n-pythagorean iff for any n-fold Pfister form ρ. There exists an odd integer l(>1) such that l×ρ is a round quadratic form (Theorem 8). By considering upper bounds for the number of squares on Pfister’s interpretation, these results finally lead to the main result (Theorem 10) such that the generalization of pythagorean fields coincides with the generalization of Hilbert’s 17th Problem.展开更多
This article first presents an overview of the Internationa] Symposium on Lepton-Photon Interactions (LP’95) and briefly introduce Chinese research achievements in the discipline. It highlights the necessity and impo...This article first presents an overview of the Internationa] Symposium on Lepton-Photon Interactions (LP’95) and briefly introduce Chinese research achievements in the discipline. It highlights the necessity and importance of international cooperation in the HEP community of the world.展开更多
卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulat...卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulatory T cell,Treg细胞)的比例失调。Th17/Treg平衡受炎症因子、核因子κB(nuclear factor-κB,NF-κB)通路及哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的精密调控,其失衡会加剧卵巢局部炎症,加速卵泡耗竭。目前,针对Th17/Treg比例失衡的干预策略在自身免疫性疾病的治疗中已取得进展,为卵巢衰老的临床干预提供了新思路。综述Th17/Treg比例失衡在卵巢衰老中的核心作用,为探索延缓卵巢衰老的免疫治疗策略提供了理论依据。展开更多
文摘The notion of preordering, which is a generalization of the notion of ordering, has been introduced by Serre. On the other hand, the notion of round quadratic forms has been introduced by Witt. Based on these ideas, it is here shown that 1) a field F is formally real n-pythagorean iff the nth radical, RnF is a preordering (Theorem 2), and 2) a field F is n-pythagorean iff for any n-fold Pfister form ρ. There exists an odd integer l(>1) such that l×ρ is a round quadratic form (Theorem 8). By considering upper bounds for the number of squares on Pfister’s interpretation, these results finally lead to the main result (Theorem 10) such that the generalization of pythagorean fields coincides with the generalization of Hilbert’s 17th Problem.
文摘This article first presents an overview of the Internationa] Symposium on Lepton-Photon Interactions (LP’95) and briefly introduce Chinese research achievements in the discipline. It highlights the necessity and importance of international cooperation in the HEP community of the world.
文摘卵巢衰老分为生理性与病理性两类,表现为卵巢储备功能下降、卵泡数量减少和激素水平紊乱,并与多种慢性疾病风险相关。研究发现,免疫失衡在卵巢衰老中扮演核心角色,尤其是辅助性T细胞17(helper T cell 17,Th17细胞)与调节性T细胞(regulatory T cell,Treg细胞)的比例失调。Th17/Treg平衡受炎症因子、核因子κB(nuclear factor-κB,NF-κB)通路及哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路的精密调控,其失衡会加剧卵巢局部炎症,加速卵泡耗竭。目前,针对Th17/Treg比例失衡的干预策略在自身免疫性疾病的治疗中已取得进展,为卵巢衰老的临床干预提供了新思路。综述Th17/Treg比例失衡在卵巢衰老中的核心作用,为探索延缓卵巢衰老的免疫治疗策略提供了理论依据。
