碳环构筑在药物与功能材料合成中至关重要,炔烃广泛应用于环合反应,但碳环合成仍具挑战。因此,新型炔烃碳环化策略成为研究热点,其中RATC策略为碳环构筑提供了新思路。本文介绍了RATC反应的研究进展,分子内RATC反应如Heiba等多取代环戊...碳环构筑在药物与功能材料合成中至关重要,炔烃广泛应用于环合反应,但碳环合成仍具挑战。因此,新型炔烃碳环化策略成为研究热点,其中RATC策略为碳环构筑提供了新思路。本文介绍了RATC反应的研究进展,分子内RATC反应如Heiba等多取代环戊烷制备、刘心元等6(5)-6-5稠环构建及Studer等1-三氟甲基炔丙基环戊烷合成。随后,文章探讨分子间RATC策略,介绍了李金恒等以1,4-二氧六环为自由基前体的Inter-RATC反应和张国柱等通过Inter-RATC构建环丁烷的反应,尽管存在局限性,但它们为碳环构筑提供了新方法。The construction of carbon rings is crucial in the synthesis of pharmaceuticals and functional materials. Alkynes are widely used in cyclization reactions, yet the synthesis of carbon rings remains challenging. Therefore, novel alkyne carbon cyclization strategies have become a research hotspot, among which the RATC strategy offers new insights into carbon ring construction. This article introduces the research progress of RATC reactions, focusing on intramolecular RATC reactions such as the preparation of multisubstituted cyclopentanes by Heiba et al., the construction of 6(5)-6-5 fused rings by Liu et al. and the synthesis of 1-trifluoromethylallylcyclopentanes by Studer et al. Subsequently, the article explores intermolecular RATC strategies, presenting the Inter-RATC reaction using 1,4-dioxane as a radical precursor by Li et al. and the construction of cyclobutanes through Inter-RATC by Zhang et al. Despite their limitations, these strategies provide novel methods for carbon ring construction.展开更多
榆绿木(Anogeissus acuminata var.lanceolata)在我国为一新纪录种,发现于云南省思茅县小橄榄坝为中心的狭窄河谷地带。本文对榆绿木的生态习性、生长特性和自然更新状况作了详细的分析,并对其材质和材性进行测定。榆绿木的气干容重为0....榆绿木(Anogeissus acuminata var.lanceolata)在我国为一新纪录种,发现于云南省思茅县小橄榄坝为中心的狭窄河谷地带。本文对榆绿木的生态习性、生长特性和自然更新状况作了详细的分析,并对其材质和材性进行测定。榆绿木的气干容重为0.896 g/cm^3;顺纹抗压和抗弯强度之和高达1775 kg f/cm^2;静曲弹性模量203000 kg f/cm^2;冲击韧性达1.385kq f. m/Cm^2,是具有高强度、高韧性的工业用材。可作建筑、车辆、农具、体育运动器材及军工等用材。速生、耐旱,是一种有前途的干热河谷造林树种,还可作鞣料林和能源薪炭林栽培,具有很高的生态和经济价值。本文还对这一树种目前所面临的威胁作了分析,为合理开发利用及保护榆绿木森林资源提出了建议。展开更多
Left ventricular diastolic function in 49 subjccts were studiedcineangiographically and compared with relevant indexes of radionuclide angiography(RNA).Normalizcd peak filling rate(NPFR),1/3 filling fraction(FF1/3),lc...Left ventricular diastolic function in 49 subjccts were studiedcineangiographically and compared with relevant indexes of radionuclide angiography(RNA).Normalizcd peak filling rate(NPFR),1/3 filling fraction(FF1/3),lcftventricular compliance in 23 patients with coronary artery disease(CAD)weresignificantly lower than that in normal control group(n=14),and the time to peak fil-ling rate(TPFR)was longer in CAD patients,Hypertension group(n=12)had someslight changes in left ventricular diastolic function.However,50%(6/12)of paticnts inCAD group with normal EF(EF】0.65)had a diminished NPFR also.FF 1/3 ofcineangiography had a good correlation with that of RNA.The results indicated thatdiastolic filling function estimated cinceangiographically might reflcet earlier and more sensi-tive changes than left ventricular systolic function in patients with CAD.FF 1/3 mea-sured by RNA might also be a useful noninvasive index in evaluating diastolic filling fune-tion.展开更多
文摘碳环构筑在药物与功能材料合成中至关重要,炔烃广泛应用于环合反应,但碳环合成仍具挑战。因此,新型炔烃碳环化策略成为研究热点,其中RATC策略为碳环构筑提供了新思路。本文介绍了RATC反应的研究进展,分子内RATC反应如Heiba等多取代环戊烷制备、刘心元等6(5)-6-5稠环构建及Studer等1-三氟甲基炔丙基环戊烷合成。随后,文章探讨分子间RATC策略,介绍了李金恒等以1,4-二氧六环为自由基前体的Inter-RATC反应和张国柱等通过Inter-RATC构建环丁烷的反应,尽管存在局限性,但它们为碳环构筑提供了新方法。The construction of carbon rings is crucial in the synthesis of pharmaceuticals and functional materials. Alkynes are widely used in cyclization reactions, yet the synthesis of carbon rings remains challenging. Therefore, novel alkyne carbon cyclization strategies have become a research hotspot, among which the RATC strategy offers new insights into carbon ring construction. This article introduces the research progress of RATC reactions, focusing on intramolecular RATC reactions such as the preparation of multisubstituted cyclopentanes by Heiba et al., the construction of 6(5)-6-5 fused rings by Liu et al. and the synthesis of 1-trifluoromethylallylcyclopentanes by Studer et al. Subsequently, the article explores intermolecular RATC strategies, presenting the Inter-RATC reaction using 1,4-dioxane as a radical precursor by Li et al. and the construction of cyclobutanes through Inter-RATC by Zhang et al. Despite their limitations, these strategies provide novel methods for carbon ring construction.
文摘榆绿木(Anogeissus acuminata var.lanceolata)在我国为一新纪录种,发现于云南省思茅县小橄榄坝为中心的狭窄河谷地带。本文对榆绿木的生态习性、生长特性和自然更新状况作了详细的分析,并对其材质和材性进行测定。榆绿木的气干容重为0.896 g/cm^3;顺纹抗压和抗弯强度之和高达1775 kg f/cm^2;静曲弹性模量203000 kg f/cm^2;冲击韧性达1.385kq f. m/Cm^2,是具有高强度、高韧性的工业用材。可作建筑、车辆、农具、体育运动器材及军工等用材。速生、耐旱,是一种有前途的干热河谷造林树种,还可作鞣料林和能源薪炭林栽培,具有很高的生态和经济价值。本文还对这一树种目前所面临的威胁作了分析,为合理开发利用及保护榆绿木森林资源提出了建议。
文摘Left ventricular diastolic function in 49 subjccts were studiedcineangiographically and compared with relevant indexes of radionuclide angiography(RNA).Normalizcd peak filling rate(NPFR),1/3 filling fraction(FF1/3),lcftventricular compliance in 23 patients with coronary artery disease(CAD)weresignificantly lower than that in normal control group(n=14),and the time to peak fil-ling rate(TPFR)was longer in CAD patients,Hypertension group(n=12)had someslight changes in left ventricular diastolic function.However,50%(6/12)of paticnts inCAD group with normal EF(EF】0.65)had a diminished NPFR also.FF 1/3 ofcineangiography had a good correlation with that of RNA.The results indicated thatdiastolic filling function estimated cinceangiographically might reflcet earlier and more sensi-tive changes than left ventricular systolic function in patients with CAD.FF 1/3 mea-sured by RNA might also be a useful noninvasive index in evaluating diastolic filling fune-tion.
