In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique ...In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique has been previously demonstrated to effectively improve the erosion resistance of slopes.Seawater contains magnesium ions(Mg^(2+))with a higher concentration than calcium ions(Ca^(2+));therefore,Mg^(2+)and Ca^(2+)were used together for bio-cementation in this study at various Mg^(2+)/Ca^(2+)ratios as the microbially induced magnesium and calcium precipitation(MIMCP)treatment.Slope angles,surface strengths,precipitation contents,major phases,and microscopic characteristics of precipitation were used to evaluate the treatment effects.Results showed that the MIMCP treatment markedly enhanced the erosion resistance of slopes.Decreased Mg^(2+)/Ca^(2+)ratios resulted in a smaller change in angles and fewer soil losses,especially the Mg^(2+)concentration below 0.2 M.The decreased Mg^(2+)/Ca^(2+)ratio achieved increased precipitation contents,which contributed to better erosion resistance and higher surface strengths.Additionally,the production of aragonite would benefit from elevated Mg^(2+)concentrations and a higher Ca^(2+)concentration led to more nesquehonite in magnesium precipitation crystals.The slopes with an initial angle of 53°had worse erosion resistance than the slopes with an initial angle of 35°,but the Mg^(2+)/Ca^(2+)ratios of 0.2:0.8,0.1:0.9,and 0:1.0 were effective for both slope stabilization and erosion mitigation to a great extent.The results are of great significance for the application of MIMCP to improve erosion resistance of foreshore slopes and the MIMCP technique has promising application potential in marine engineering.展开更多
多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸...多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)及哺乳动物雷帕霉素靶蛋白(Mammalian target of rapamycin,mTOR)作为细胞能量感受器是其中两个关键靶点。二者在PCOS各个发病部位包括下丘脑-垂体-卵巢轴、子宫内膜、脂肪与骨骼肌中发挥重要的调节作用,通过影响细胞自噬、氧化应激、炎症、线粒体功能、葡萄糖摄取等,促进卵泡的发育和成熟,改善胰岛素抵抗。近年来,中医药因其成分多样、靶点众多等优势广泛应用于临床,研究人员已对PCOS的发病以及中药治疗及改善PCOS的机制进行了大量研究,结果提示AMPK与mTOR相关通路在其中发挥关键作用。通过总结中药干预AMPK与mTOR及其相关通路治疗PCOS的研究结果,为临床治疗及基础研究提供参考。展开更多
神经病理性疼痛往往由神经系统原发性损害和功能障碍所引起,患者常表现为自发性疼痛或痛觉过敏症状。近年研究表明,AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)作为关键的能量调节因子,不仅通过调节糖脂代谢参与维持机体内环...神经病理性疼痛往往由神经系统原发性损害和功能障碍所引起,患者常表现为自发性疼痛或痛觉过敏症状。近年研究表明,AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)作为关键的能量调节因子,不仅通过调节糖脂代谢参与维持机体内环境稳定,也可以通过相关信号通路调节突触可塑性和神经胶质细胞功能,在一些神经系统疾病的发生与进展中发挥作用。近年来,多项针对神经病理性疼痛的动物模型实验和临床研究表明,在感觉传导通路的多个位点上,AMPK的表达及活性异常,给予AMPK激动剂治疗后,疼痛症状缓解,这提示AMPK的表达/功能异常参与了神经病理性疼痛的发生与维持,因此基于AMPK的镇痛药物研发受到广泛关注。本文就AMPK参与神经病理性疼痛相关机制的进展进行综述,希望能够为相关镇痛药物研发提供参考。展开更多
A straightforward conceptual method is proposed to quantitatively assess the seasonal-scale tendency of retreatment or advancement on microtidal beaches by using the backshore/foreshore length ratio. This method is ba...A straightforward conceptual method is proposed to quantitatively assess the seasonal-scale tendency of retreatment or advancement on microtidal beaches by using the backshore/foreshore length ratio. This method is based on measuring the cross-shore profile of a beach when it passes through the “transitional state” that separates the high-from the low-energy season, period during which the morphological characteristics of the beach tend to its equilibrium profile. In order to obtain real measurements of backshore (B) and foreshore (F), the definition of the limits bounding these two important components in subaerial beaches is reviewed and discussed. The approach based on the measurement of the?B/F?length ratio assumes that foreshore and backshore have equivalent lengths in beaches that approximate to their state of morphodynamic equilibrium (B/F?~ 1). A backshore length exceeding the foreshore length is indicative of a state of beach recession, with a?B/F?length ratio > 1. When the foreshore length is greater than the backshore length, the shoreline is advancing or, alternatively, it is developing in a state of morphological confinement,?i.e.?due to the presence of a sea cliff, with a?B/F?< 1. This practical method is then tested against 36 sand and gravel microtidal beach profiles measured along the coasts of Basilicata, in southern Italy. The various “beach states” are summarised into seven classes (I-VII), each identified from specific value intervals of the?B/F?length ratio.展开更多
基金funded by the National Natural Science Foundation of China(Grant No.51578147)Fundamental Research Funds for the Central Universities(Grant No.2242020R20025)Ningxia Science and Technology Department(Grant No.2020BFG02014).
文摘In most coastal and estuarine areas,tides easily cause surface erosion and even slope failure,resulting in severe land losses,deterioration of coastal infrastructure,and increased floods.The bio-cementation technique has been previously demonstrated to effectively improve the erosion resistance of slopes.Seawater contains magnesium ions(Mg^(2+))with a higher concentration than calcium ions(Ca^(2+));therefore,Mg^(2+)and Ca^(2+)were used together for bio-cementation in this study at various Mg^(2+)/Ca^(2+)ratios as the microbially induced magnesium and calcium precipitation(MIMCP)treatment.Slope angles,surface strengths,precipitation contents,major phases,and microscopic characteristics of precipitation were used to evaluate the treatment effects.Results showed that the MIMCP treatment markedly enhanced the erosion resistance of slopes.Decreased Mg^(2+)/Ca^(2+)ratios resulted in a smaller change in angles and fewer soil losses,especially the Mg^(2+)concentration below 0.2 M.The decreased Mg^(2+)/Ca^(2+)ratio achieved increased precipitation contents,which contributed to better erosion resistance and higher surface strengths.Additionally,the production of aragonite would benefit from elevated Mg^(2+)concentrations and a higher Ca^(2+)concentration led to more nesquehonite in magnesium precipitation crystals.The slopes with an initial angle of 53°had worse erosion resistance than the slopes with an initial angle of 35°,but the Mg^(2+)/Ca^(2+)ratios of 0.2:0.8,0.1:0.9,and 0:1.0 were effective for both slope stabilization and erosion mitigation to a great extent.The results are of great significance for the application of MIMCP to improve erosion resistance of foreshore slopes and the MIMCP technique has promising application potential in marine engineering.
文摘多囊卵巢综合征(Polycystic ovary syndrome,PCOS)是一组生殖内分泌代谢紊乱的综合征,临床以稀发排卵、高雄激素体征、胰岛素抵抗为主要特征,其中育龄期发病率高,对女性生育力造成严重不良影响。PCOS的发生发展涉及多种信号通路,腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)及哺乳动物雷帕霉素靶蛋白(Mammalian target of rapamycin,mTOR)作为细胞能量感受器是其中两个关键靶点。二者在PCOS各个发病部位包括下丘脑-垂体-卵巢轴、子宫内膜、脂肪与骨骼肌中发挥重要的调节作用,通过影响细胞自噬、氧化应激、炎症、线粒体功能、葡萄糖摄取等,促进卵泡的发育和成熟,改善胰岛素抵抗。近年来,中医药因其成分多样、靶点众多等优势广泛应用于临床,研究人员已对PCOS的发病以及中药治疗及改善PCOS的机制进行了大量研究,结果提示AMPK与mTOR相关通路在其中发挥关键作用。通过总结中药干预AMPK与mTOR及其相关通路治疗PCOS的研究结果,为临床治疗及基础研究提供参考。
文摘神经病理性疼痛往往由神经系统原发性损害和功能障碍所引起,患者常表现为自发性疼痛或痛觉过敏症状。近年研究表明,AMP活化蛋白激酶(AMP-activated protein kinase,AMPK)作为关键的能量调节因子,不仅通过调节糖脂代谢参与维持机体内环境稳定,也可以通过相关信号通路调节突触可塑性和神经胶质细胞功能,在一些神经系统疾病的发生与进展中发挥作用。近年来,多项针对神经病理性疼痛的动物模型实验和临床研究表明,在感觉传导通路的多个位点上,AMPK的表达及活性异常,给予AMPK激动剂治疗后,疼痛症状缓解,这提示AMPK的表达/功能异常参与了神经病理性疼痛的发生与维持,因此基于AMPK的镇痛药物研发受到广泛关注。本文就AMPK参与神经病理性疼痛相关机制的进展进行综述,希望能够为相关镇痛药物研发提供参考。
文摘A straightforward conceptual method is proposed to quantitatively assess the seasonal-scale tendency of retreatment or advancement on microtidal beaches by using the backshore/foreshore length ratio. This method is based on measuring the cross-shore profile of a beach when it passes through the “transitional state” that separates the high-from the low-energy season, period during which the morphological characteristics of the beach tend to its equilibrium profile. In order to obtain real measurements of backshore (B) and foreshore (F), the definition of the limits bounding these two important components in subaerial beaches is reviewed and discussed. The approach based on the measurement of the?B/F?length ratio assumes that foreshore and backshore have equivalent lengths in beaches that approximate to their state of morphodynamic equilibrium (B/F?~ 1). A backshore length exceeding the foreshore length is indicative of a state of beach recession, with a?B/F?length ratio > 1. When the foreshore length is greater than the backshore length, the shoreline is advancing or, alternatively, it is developing in a state of morphological confinement,?i.e.?due to the presence of a sea cliff, with a?B/F?< 1. This practical method is then tested against 36 sand and gravel microtidal beach profiles measured along the coasts of Basilicata, in southern Italy. The various “beach states” are summarised into seven classes (I-VII), each identified from specific value intervals of the?B/F?length ratio.