Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselect...Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselectively in high yields using PdCl2, CuCl2, and CO2 as the catalytic system. However, tert-butylacetylene bearing a bulky group gave a dimerization product. Mechanism of this reaction was also discussed.展开更多
Carbon dioxide as both a selective agent and reaction media in the palladium-catalyzed Ullmann-type coupling has been described. The results showed that aryl chlorides could be easily activated in the presence of carb...Carbon dioxide as both a selective agent and reaction media in the palladium-catalyzed Ullmann-type coupling has been described. The results showed that aryl chlorides could be easily activated in the presence of carbon diox-ide and the chemoselectivity shifted toward the palladium-catalyzed Ullmann-type coupling reaction. In liquid car-bon dioxide, homocoupling reactions of aryl halides, including less reactive aryl chlorides, were carried out smoothly in moderate to good yields using Pd/C, zinc, and H2O as the catalytic system at room temperature.展开更多
A more feasibly convergent synthesis of selective estrogen receptor degrading agent(S)-8-(4-((1-(3-fluoropropyl)-pyrrolidin-3-yl)oxy)phenyl)-7-(4-hydroxyphenyl)-5,6-dihydronaphthalen-2-ol was reported,featured with co...A more feasibly convergent synthesis of selective estrogen receptor degrading agent(S)-8-(4-((1-(3-fluoropropyl)-pyrrolidin-3-yl)oxy)phenyl)-7-(4-hydroxyphenyl)-5,6-dihydronaphthalen-2-ol was reported,featured with concise work up and absence of regioselectivity dilemma.展开更多
Owing to unique advantages of patternability and high substrate compatibility,screen-printing allows for the fabrication of flexible perovskite solar cells(f-PSCs)with designable device patterns,while the defective an...Owing to unique advantages of patternability and high substrate compatibility,screen-printing allows for the fabrication of flexible perovskite solar cells(f-PSCs)with designable device patterns,while the defective and fragile contact at the buried interface seriously restricted the device performance.Herein,a series of siloxane coupling agents(SCAs)with different ending groups i.e.,-SH,-NH_(2),and-CN were incorporated at the SnO_(2)/perovskite interface,which can selectively interact with MA+and Pb^(2+)via hydrogen and coordination bonding,respectively.It was revealed that the selection of(3-Cyanopropyl)Triethoxysilane(CN-PTES)can regulate perovskite crystallization with accelerated nucleation and retarded crystal growth,leading to improved crystallinity with released residual lattice strain.Moreover,the incorporated CN-PTES aligned the energy structure of the underlying SnO_(2)and boosted the interfacial adhesion between perovskite and SnO_(2),resulting in facilitated electron extraction and enhanced interfacial fracture energy.Consequently,the first screen-printed f-PSCs with improved mechanical resistance were finally obtained.展开更多
In 1979,the mechanism of chemical carcinogenesis,a challenging anddifficult scientific problem pending for a number of years,was explained by Dai Qianhuan.Themechanism named di-region theory predicted that a carcinoge...In 1979,the mechanism of chemical carcinogenesis,a challenging anddifficult scientific problem pending for a number of years,was explained by Dai Qianhuan.Themechanism named di-region theory predicted that a carcinogen always metabolizes to form a specialbi-functional alky-lating agent.This agent induces cross-linkages between the complementary basepairs in DMA and switches on initial mutageneses in genomes including point and frameshiftmutations.This,in turn,induces further deep mutageneses including the production of variouschimeric chromosomes,deletions and other aberrations found in genomes.In the end this initiatescarcinogenesis of the whole cell through the reverse transcription mechanism after a lengthyincubation period.Recently,this laboratory has verified that physical carcinogenesis,includingthe oncogenesis induced by radiation and asbestos as well as the carcinogenesis induced byendogenous factors such as estrogen or diethyl-stilbestrol switch on carcinogenesis by inducing theformation of cross-linkages between the complementary base pairs in DNA.Di-region theory has nowbeen supported by many experimental observations such as mutational spectra of various carcinogens.The potential for carcinogenesis,teratogenesis,sterility and mutagenesis lumped together asgenetic toxicity appears to originate almost uniformly from the cross-linking between complementarybases,i.e.malignant cross-linking,which is in accordance with di-region theory.Other forms ofcross-linking between non-complementary bases,benign cross-linkings,show bi-functional alkylationanticancer activity but lack genetic toxicity.The predictable design and synthesis of a highselectivity anticancer agent with high efficacy and low genetic toxicity,a goal long pursued incancer chemotherapy,have been realized for the first time in this laboratory by inhibitingmalignant and heightening benign cross-linking using the principles of di-region theory.A series ofpatented new anticancer platinum complexes called di-regioplatins,based on the above predetermineddesign,have been reported.In these cancer cell kill rates,tumor-inhibition rates and theultimate life-span for two mouse carcinoma models using several compounds ofcis-di-substituted-benzylaminodihaloplatinum(II)are notably higher than those of cisplatin,buttheir toxicities all are much lower than cisplatin.Based on a predictive design using di-regiontheory and group theory,a new anticancer complex,cis-diammine-cyclopentane-1,1-dicarboxylato-platinum(II)called minoplatin,has been synthesized inthis laboratory by making the minimal structural revision of adding an CH_2 unit on the four-memberring of carboplatin.展开更多
Nano-phase change emulsions(NPCEs)are attractive thermal fluids for applications such as cold-chain logistics,vaccine storage,and low-temperature energy systems operating in the 0–20℃range.However,their deployment i...Nano-phase change emulsions(NPCEs)are attractive thermal fluids for applications such as cold-chain logistics,vaccine storage,and low-temperature energy systems operating in the 0–20℃range.However,their deployment is hindered by significant supercooling and poor stability under shear.Here,we report a formulation strategy combining surfactant and nucleating agent optimization to prepare NPCEs with suppressed supercooling(<0.5℃)and high dispersion stability.The NPCEs maintain structural integrity after 24 h of continuous shear at 5℃,with droplet size variation within 20 nm.Rheological and microscopic analyses elucidate the interfacial disruption mechanism under low-temperature shear,and a nucleating agent selection principle is established based on molecular conformation and crystallization compatibility.To address performance degradation,we develop a high-energy ultrasonic on-line regeneration method that rapidly restores thermal functionality without system downtime.The NPCEs achieve>99.5%latent heat recovery and maintain stable performance over 60 days of thermal and mechanical cycling.This work demonstrates a regenerable NPCE system featuring ultra-low supercooling and long-term operational stability.The findings offer a practical pathway for scalable deployment of advanced thermal fluids in energy-efficient industrial applications.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20202002) Hunan Province Education Department (No. 02C211) and Hunan Normal University (2001).
文摘Carbon dioxide was found as a selective agent to promote the palladium-catalyzed cyclotrimerization of alkynes in water. Both aryl and alkylacetylenes afforded the corresponding cyclotrimerization products regioselectively in high yields using PdCl2, CuCl2, and CO2 as the catalytic system. However, tert-butylacetylene bearing a bulky group gave a dimerization product. Mechanism of this reaction was also discussed.
基金the National Natural Science Foundation of China (No. 20202002), Hunan Province Department of Education (No. 02C211) and Hunan Normal University (2001).
文摘Carbon dioxide as both a selective agent and reaction media in the palladium-catalyzed Ullmann-type coupling has been described. The results showed that aryl chlorides could be easily activated in the presence of carbon diox-ide and the chemoselectivity shifted toward the palladium-catalyzed Ullmann-type coupling reaction. In liquid car-bon dioxide, homocoupling reactions of aryl halides, including less reactive aryl chlorides, were carried out smoothly in moderate to good yields using Pd/C, zinc, and H2O as the catalytic system at room temperature.
文摘A more feasibly convergent synthesis of selective estrogen receptor degrading agent(S)-8-(4-((1-(3-fluoropropyl)-pyrrolidin-3-yl)oxy)phenyl)-7-(4-hydroxyphenyl)-5,6-dihydronaphthalen-2-ol was reported,featured with concise work up and absence of regioselectivity dilemma.
基金supported by the Natural Science Foundation of China(22425903,U24A20568,61705102,62288102,22409091,22409090 and 62205142)the National Key R&D Program of China(2023YFB4204500,2020YFA07099003)+1 种基金the Jiangsu Provincial Departments of Science and Technology(BK20241875,BE2022023,BK20220010,and BZ2023060)the Excellent Doctoral Dissertation Cultivation Program of Nanjing Tech University(2023-02).
文摘Owing to unique advantages of patternability and high substrate compatibility,screen-printing allows for the fabrication of flexible perovskite solar cells(f-PSCs)with designable device patterns,while the defective and fragile contact at the buried interface seriously restricted the device performance.Herein,a series of siloxane coupling agents(SCAs)with different ending groups i.e.,-SH,-NH_(2),and-CN were incorporated at the SnO_(2)/perovskite interface,which can selectively interact with MA+and Pb^(2+)via hydrogen and coordination bonding,respectively.It was revealed that the selection of(3-Cyanopropyl)Triethoxysilane(CN-PTES)can regulate perovskite crystallization with accelerated nucleation and retarded crystal growth,leading to improved crystallinity with released residual lattice strain.Moreover,the incorporated CN-PTES aligned the energy structure of the underlying SnO_(2)and boosted the interfacial adhesion between perovskite and SnO_(2),resulting in facilitated electron extraction and enhanced interfacial fracture energy.Consequently,the first screen-printed f-PSCs with improved mechanical resistance were finally obtained.
文摘In 1979,the mechanism of chemical carcinogenesis,a challenging anddifficult scientific problem pending for a number of years,was explained by Dai Qianhuan.Themechanism named di-region theory predicted that a carcinogen always metabolizes to form a specialbi-functional alky-lating agent.This agent induces cross-linkages between the complementary basepairs in DMA and switches on initial mutageneses in genomes including point and frameshiftmutations.This,in turn,induces further deep mutageneses including the production of variouschimeric chromosomes,deletions and other aberrations found in genomes.In the end this initiatescarcinogenesis of the whole cell through the reverse transcription mechanism after a lengthyincubation period.Recently,this laboratory has verified that physical carcinogenesis,includingthe oncogenesis induced by radiation and asbestos as well as the carcinogenesis induced byendogenous factors such as estrogen or diethyl-stilbestrol switch on carcinogenesis by inducing theformation of cross-linkages between the complementary base pairs in DNA.Di-region theory has nowbeen supported by many experimental observations such as mutational spectra of various carcinogens.The potential for carcinogenesis,teratogenesis,sterility and mutagenesis lumped together asgenetic toxicity appears to originate almost uniformly from the cross-linking between complementarybases,i.e.malignant cross-linking,which is in accordance with di-region theory.Other forms ofcross-linking between non-complementary bases,benign cross-linkings,show bi-functional alkylationanticancer activity but lack genetic toxicity.The predictable design and synthesis of a highselectivity anticancer agent with high efficacy and low genetic toxicity,a goal long pursued incancer chemotherapy,have been realized for the first time in this laboratory by inhibitingmalignant and heightening benign cross-linking using the principles of di-region theory.A series ofpatented new anticancer platinum complexes called di-regioplatins,based on the above predetermineddesign,have been reported.In these cancer cell kill rates,tumor-inhibition rates and theultimate life-span for two mouse carcinoma models using several compounds ofcis-di-substituted-benzylaminodihaloplatinum(II)are notably higher than those of cisplatin,buttheir toxicities all are much lower than cisplatin.Based on a predictive design using di-regiontheory and group theory,a new anticancer complex,cis-diammine-cyclopentane-1,1-dicarboxylato-platinum(II)called minoplatin,has been synthesized inthis laboratory by making the minimal structural revision of adding an CH_2 unit on the four-memberring of carboplatin.
基金supported by Dongguan Key Research&Development Program(No.20231200300152).
文摘Nano-phase change emulsions(NPCEs)are attractive thermal fluids for applications such as cold-chain logistics,vaccine storage,and low-temperature energy systems operating in the 0–20℃range.However,their deployment is hindered by significant supercooling and poor stability under shear.Here,we report a formulation strategy combining surfactant and nucleating agent optimization to prepare NPCEs with suppressed supercooling(<0.5℃)and high dispersion stability.The NPCEs maintain structural integrity after 24 h of continuous shear at 5℃,with droplet size variation within 20 nm.Rheological and microscopic analyses elucidate the interfacial disruption mechanism under low-temperature shear,and a nucleating agent selection principle is established based on molecular conformation and crystallization compatibility.To address performance degradation,we develop a high-energy ultrasonic on-line regeneration method that rapidly restores thermal functionality without system downtime.The NPCEs achieve>99.5%latent heat recovery and maintain stable performance over 60 days of thermal and mechanical cycling.This work demonstrates a regenerable NPCE system featuring ultra-low supercooling and long-term operational stability.The findings offer a practical pathway for scalable deployment of advanced thermal fluids in energy-efficient industrial applications.
