The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demon...The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demonstrate the enzyme‐like mechanism of the reaction over hexadecylphosphateacid(HDPA)‐bonded nano‐oxides,which appear to interact with toluene through specific recognition.The active sites of the catalyst are related to the ability of HDPA to change its bonding to theoxides between monodentate and bidentate during the reaction cycle.This greatly enhances themobility of the crystal oxygen or the reactivity of the catalyst,specifically in toluene transformations.The catalytic cycle of the catalyst is similar to that of methane monooxygenase.In thepresence of catalyst and through O_(2)oxidation,the conversion of toluene to benzaldehyde is initiatedat 70°C.We envision that this novel mechanism reveals alternatives for an attractive route to designhigh‐performance catalysts with bioinspired structures.展开更多
文摘目的分析去势抵抗型前列腺癌(castration resistant prostate cancer,CRPC)患者接受醋酸阿比特龙(abiraterone acetate,AA)联合强的松(prednisone,P)治疗的疗效及安全性,为后续治疗提供经验。方法筛选2018年7月至2021年4月首都医科大学附属北京朝阳医院泌尿外科共计46例CRPC患者,选择使用AA+P治疗,最后共计37例患者纳入研究。分析37例患者的基本资料,参照前列腺特异抗原(prostate specific antigen,PSA)工作组2(PSA Working Group 2,PSAWG2)标准计算PSA缓解率,按照实体瘤的疗效评价(response evaluation criteria in solid tumors,RECIST)标准评估患者治疗期间的影像学结果,同时分析行多西他赛化疗、PSA闪烁现象以及基线PSA水平、肿瘤T分期、Gleason评分等指标对AA+P治疗的PSA缓解率的影响差异。结果37例CRPC患者接受AA+P治疗,中位随访时间9.7个月。在接受AA+P初始,有5例患者发生了PSA闪烁现象,其PSA达峰再次下降至基线水平以下的中位时间为3.0(2.0,4.5)个月。37例患者PSA总体缓解率为59.5%,其中13例患者达到缓解后又发生了PSA复发,其中位复发时间为7.0个月。参照RECIST标准,37例CRPC患者中,有7例患者发生了影像学进展,而5例有明确的影像学缓解。6例达到PSA缓解后出现复发的患者将强的松转换为地塞米松,其中2例PSA再次缓解,PSA缓解率为33.3%。化疗失败后接受AA+P的患者PSA缓解低于未行化疗的患者(20.0%vs 65.6%,P=0.076)。此外,有PSA闪烁现象的PSA缓解率低于无此现象的患者(20.0%vs 65.6%,P=0.076)。醋酸阿比特龙的总体耐受性较好,药物不良反应少。结论CRPC患者口服醋酸阿比特龙联合强的松疗效确切,安全性高,对于不愿意选择或不能耐受化疗的患者,有较高的PSA缓解率。PSA闪烁现象在AA治疗过程中并不少见,这部分患者达到PSA缓解的比例较低。PSA缓解后的中位复发时间为7.0个月,部分PSA进展患者用地塞米松替换强的松可重新达到PSA缓解,可恢复对阿比特龙治疗的敏感性。
文摘The completely selective oxidation of toluene to benzaldehyde with dioxygen,without the need touse H_(2)O_(2),halogens,or any radical initiators,is a reaction long desired but never previously successful.Here,we demonstrate the enzyme‐like mechanism of the reaction over hexadecylphosphateacid(HDPA)‐bonded nano‐oxides,which appear to interact with toluene through specific recognition.The active sites of the catalyst are related to the ability of HDPA to change its bonding to theoxides between monodentate and bidentate during the reaction cycle.This greatly enhances themobility of the crystal oxygen or the reactivity of the catalyst,specifically in toluene transformations.The catalytic cycle of the catalyst is similar to that of methane monooxygenase.In thepresence of catalyst and through O_(2)oxidation,the conversion of toluene to benzaldehyde is initiatedat 70°C.We envision that this novel mechanism reveals alternatives for an attractive route to designhigh‐performance catalysts with bioinspired structures.
