The significant role of square root mapping in probability,statistics,physics,architecture and engineering motivates us to emphasize on a new radical functional equation arising from a square root and reciprocal squar...The significant role of square root mapping in probability,statistics,physics,architecture and engineering motivates us to emphasize on a new radical functional equation arising from a square root and reciprocal square root mappings.The interesting attribute of this equation is that it has both a square root mapping and a reciprocal square root mapping as solutions.We establish that the hyperstabilities of this equation exist using a fixed point alternative theorem.It is also demonstrated with an example that the stability may fail in special cases.展开更多
Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivativ...Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.展开更多
The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR s...The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD （T） method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.展开更多
It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepar...It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide（GOCOOH） with N-chlorosuccinimide（NCS） at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide（GO） in three steps.展开更多
Objective: to discuss the effect of laparoscopic radical prostatectomy for prostate cancer in patients with prostate cancer, and explore the effect of this treatment method on the improvement of bladder function. Meth...Objective: to discuss the effect of laparoscopic radical prostatectomy for prostate cancer in patients with prostate cancer, and explore the effect of this treatment method on the improvement of bladder function. Methods: 80 cases of prostate cancer patients received treatment in our hospital were selected as the object of the study, and then they were divided into equal groups, respectively as the control group and observation group. In the grouping study, patients in the control group were treated with open radical prostatectomy, while patients in the observation group were treated with laparoscopic radical prostatectomy. At the end of the study, the clinical indicators and improvement of bladder function of patients in the two groups were compared. Results: the clinical indicators and bladder function improvement data of the control group were compared for reference, and the observation group had significant advantages, P<0.05. Conclusion: in patients with prostate cancer treated by laparoscopic radical prostatectomy, clinical indicators and bladder function are improved, which has a positive impact on the improvement of prognosis and quality of life of patients.展开更多
Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso...Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso compound feedstocks.Two strategic modes have been developed for these reactions,which differ in the nature of the stereo-determining steps.The first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents,whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical species.This mini-review explores the research progress in this growing field,aiming to elucidate mechanistic scenarios related to stereochemical control.Additionally,it offers insights into the challenges and opportunities that lie ahead for further development.展开更多
Catalytic cracking experiments of FCC cycle oil were carried out in a fixed fluidized bed reactor. Effects of reac- tion conditions, such as temperature, catalyst to oil ratio and weight hourly space velocity, were in...Catalytic cracking experiments of FCC cycle oil were carried out in a fixed fluidized bed reactor. Effects of reac- tion conditions, such as temperature, catalyst to oil ratio and weight hourly space velocity, were investigated. Hydrocarbon composition of gasoline was analyzed by gas chromatograph. Experimental results showed that conversion of cycle oil was low on account of its poor crackability performance, and the effect of reaction conditions on gasoline yield was obvi- ous. The paraffin content was very high in gasoline. Based on the experimental yields under different reaction conditions, a model for prediction of gasoline and diesel yields was established by radial basis function neural network （RBFNN）. In the model, the product yield was viewed as function of reaction conditions. Particle swarm optimization （PSO） algorithm with global search capability was used to obtain optimal conditions for a highest yield of light oil. The results showed that the yield of gasoline and diesel predicted by RBF neural network agreed well with the experimental values. The optimized reac- tion conditions were obtained at a reaction temperature of around 520 ~C, a catalyst to oil ratio of 7.4 and a space velocity of 8 h~. The predicted total yield of gasoline and diesel reached 42.2% under optimized conditions.展开更多
Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via ra...Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol（2-CTP） as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene（1-MCTA）, 1,6-dichlorothianthrene（1,6-DCTA）, 4,6-dichlorodibenzothiophene（4,6-DCDT）and 1,6-dichlorodibenzothiophene（1,6-DCDT）. The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.展开更多
Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral is...Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral ischemia and reperfusion. Aged rats（20–22 months） were divided into three groups： sham, model, and treatment. Shenqi Fuzheng injection or saline（40 m L/kg） was injected into the tail vein daily for 1 week, after which a cerebral ischemia/reperfusion injury model was established. Compared with model rats that received saline, rats in the treatment group had smaller infarct volumes, lower brain water and malondialdehyde content, lower brain Ca2＋ levels, lower activities of serum lactate dehydrogenase and creatine kinase, and higher superoxide dismutase activity. In addition, the treatment group showed less damage to the brain tissue ultrastructure and better neurological function. Our findings indicate that Shenqi Fuzheng injection exerts neuroprotective effects in aged rats with cerebral ischemia/reperfusion injury, and that the underlying mechanism relies on oxygen free radical scavenging and inhibition of brain Ca2＋ accumulation.展开更多
With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the dono...With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the donor-acceptor complex enables metal-free inert bond functionalizations,which was published in Angew Chem Int Ed(2017,56(41):12619-12623).展开更多
The C-H and C-C bonds are abundant in organic compounds,yet generally inert in chemical transformations.Therefore,direct functionalization of inert chemical bonds remains challenging.The fluorine-containing compounds ...The C-H and C-C bonds are abundant in organic compounds,yet generally inert in chemical transformations.Therefore,direct functionalization of inert chemical bonds remains challenging.The fluorine-containing compounds are of special interest for their uses in medicinal chemistry.Direct fluorination of C-H and C-C bonds undoubtedly represents one of the most ideal and attractive approaches to incorporate fluorine atom into complex molecules.Herein,we summarize the recent advances in radical-mediated C-H and C-C bond fluorination.Three types of transformations are discussed:(1)direct C-H abstraction/fluorination of alkanes;(2)decarboxylative fluorination of alkyl carboxylic acids;(3)ring-opening fluorination.展开更多
基金Supported by the Science and Engineering Research Board(SERB),India(MTR/2020/000534).
文摘The significant role of square root mapping in probability,statistics,physics,architecture and engineering motivates us to emphasize on a new radical functional equation arising from a square root and reciprocal square root mappings.The interesting attribute of this equation is that it has both a square root mapping and a reciprocal square root mapping as solutions.We establish that the hyperstabilities of this equation exist using a fixed point alternative theorem.It is also demonstrated with an example that the stability may fail in special cases.
文摘Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11147158 and 11264020the Jiangxi Province Natural Science Foundation under Grant No 2010GQW0031the Jiangxi Province Scientific Research Program of the Education Bureau under Grant No GJJ12483
文摘The geometric structures of an Nit radical in different external electric fields are optimized by using the density functional B3P86/cc-PVSZ method, and the bond lengths, dipole moments, vibration frequencies and IR spectrum are obtained. The potential energy curves are gained by the CCSD （T） method with the same basis set. These results indicate that the physical property parameters and potential energy curves may change with the external electric field, especially in the reverse direction electric field. The potential energy function of zero field is fitted by the Morse potential, and the fitting parameters are in good accordance with the experimental data. The potential energy functions of different external electric fields are fitted adopting the constructed potential model. The fitted critical dissociation electric parameters are shown to be consistent with the numerical calculation, and the relative errors are only 0.27% and 6.61%, hence the constructed model is reliable and accurate. The present results provide an important reference for further study of the molecular spectrum, dynamics and molecular cooling with Stark effect.
基金financially supported by the Natural Science Foundation of Inner Mongolia (No. 2014BS0202)Inner Mongolia University of Science and Technology Innovation Fund (No. 2014QDL018)Talent Incubation Funding of School of Materials and Metallurgy (No. 2014CY012)
文摘It is well-known that chemical functionalization of graphene has the great significance.We report the development of a new synthesis method of chloro-functionalized reduced graphene oxide（rGOCl）.The rGOCl was prepared by radical reaction,and treatment of carboxyl graphene oxide（GOCOOH） with N-chlorosuccinimide（NCS） at 90℃ for 10 h under an atmosphere of nitrogen,using silver nitrate as catalyst.The morphologies and structures of the prepared materials were investigated by field-emission scanning electron microscopy（FESEM）,X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,Raman spectroscopy and the thermal gravimetric.Results indicated that the rGOCl can be readily obtained from graphene oxide（GO） in three steps.
文摘Objective: to discuss the effect of laparoscopic radical prostatectomy for prostate cancer in patients with prostate cancer, and explore the effect of this treatment method on the improvement of bladder function. Methods: 80 cases of prostate cancer patients received treatment in our hospital were selected as the object of the study, and then they were divided into equal groups, respectively as the control group and observation group. In the grouping study, patients in the control group were treated with open radical prostatectomy, while patients in the observation group were treated with laparoscopic radical prostatectomy. At the end of the study, the clinical indicators and improvement of bladder function of patients in the two groups were compared. Results: the clinical indicators and bladder function improvement data of the control group were compared for reference, and the observation group had significant advantages, P<0.05. Conclusion: in patients with prostate cancer treated by laparoscopic radical prostatectomy, clinical indicators and bladder function are improved, which has a positive impact on the improvement of prognosis and quality of life of patients.
基金Financial support from the National Natural Science Foundation of China (grant nos.22025103,92256301,21831002,22271133,22101122,and 22201127)the National Key R&D Program of China (grant nos.2021YFF0701604 and 2021YFF0701704)+1 种基金New Cornerstone Science Foundation through the XPLORER PRIZE,Shenzhen Science and Technology Program (grant nos.KQTD20210811090112004 and JCYJ20220818100600001)Shenzhen Key Laboratory of Cross-Coupling Reactions (grant no.ZDSYS20220328104200001).
文摘Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules,introducing dramatically increased structural complexity from readily available prochiral or meso compound feedstocks.Two strategic modes have been developed for these reactions,which differ in the nature of the stereo-determining steps.The first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents,whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical species.This mini-review explores the research progress in this growing field,aiming to elucidate mechanistic scenarios related to stereochemical control.Additionally,it offers insights into the challenges and opportunities that lie ahead for further development.
基金support of the Chinese National Program for Fundamental Research and Development(973 program)(2012CB215006)
文摘Catalytic cracking experiments of FCC cycle oil were carried out in a fixed fluidized bed reactor. Effects of reac- tion conditions, such as temperature, catalyst to oil ratio and weight hourly space velocity, were investigated. Hydrocarbon composition of gasoline was analyzed by gas chromatograph. Experimental results showed that conversion of cycle oil was low on account of its poor crackability performance, and the effect of reaction conditions on gasoline yield was obvi- ous. The paraffin content was very high in gasoline. Based on the experimental yields under different reaction conditions, a model for prediction of gasoline and diesel yields was established by radial basis function neural network （RBFNN）. In the model, the product yield was viewed as function of reaction conditions. Particle swarm optimization （PSO） algorithm with global search capability was used to obtain optimal conditions for a highest yield of light oil. The results showed that the yield of gasoline and diesel predicted by RBF neural network agreed well with the experimental values. The optimized reac- tion conditions were obtained at a reaction temperature of around 520 ~C, a catalyst to oil ratio of 7.4 and a space velocity of 8 h~. The predicted total yield of gasoline and diesel reached 42.2% under optimized conditions.
基金supported by the National Natural Science Foundation (Nos. 21407167, 21621064, and 21607168)the Chinese Academy of Sciences (No. XDB14030500)
文摘Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol（2-CTP） as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene（1-MCTA）, 1,6-dichlorothianthrene（1,6-DCTA）, 4,6-dichlorodibenzothiophene（4,6-DCDT）and 1,6-dichlorodibenzothiophene（1,6-DCDT）. The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.
基金supported by a grant from Key Technology Research and Development Program of Shaanxi Province of China,No.2003K10-G86the National Natural Science Foundation of China,No.30070731
文摘Shenqi Fuzheng injection is extracted from the Chinese herbs Radix Astragali and Radix Codonopsis. The aim of the present study was to investigate the neuroprotective effects of Shenqi Fuzheng injection in cerebral ischemia and reperfusion. Aged rats（20–22 months） were divided into three groups： sham, model, and treatment. Shenqi Fuzheng injection or saline（40 m L/kg） was injected into the tail vein daily for 1 week, after which a cerebral ischemia/reperfusion injury model was established. Compared with model rats that received saline, rats in the treatment group had smaller infarct volumes, lower brain water and malondialdehyde content, lower brain Ca2＋ levels, lower activities of serum lactate dehydrogenase and creatine kinase, and higher superoxide dismutase activity. In addition, the treatment group showed less damage to the brain tissue ultrastructure and better neurological function. Our findings indicate that Shenqi Fuzheng injection exerts neuroprotective effects in aged rats with cerebral ischemia/reperfusion injury, and that the underlying mechanism relies on oxygen free radical scavenging and inhibition of brain Ca2＋ accumulation.
文摘With the support by the National Natural Science Foundation of China,the research group led by Prof.Chen Yiyun(陈以昀)from Shanghai Institute of Organic Chemistry,Chinese Academy of Sciences demonstrates that the donor-acceptor complex enables metal-free inert bond functionalizations,which was published in Angew Chem Int Ed(2017,56(41):12619-12623).
基金supported by Soochow University,the National Natural Science Foundation of China(21402134)the Natural Science Foundation of Jiangsu Province(BK20140306)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The C-H and C-C bonds are abundant in organic compounds,yet generally inert in chemical transformations.Therefore,direct functionalization of inert chemical bonds remains challenging.The fluorine-containing compounds are of special interest for their uses in medicinal chemistry.Direct fluorination of C-H and C-C bonds undoubtedly represents one of the most ideal and attractive approaches to incorporate fluorine atom into complex molecules.Herein,we summarize the recent advances in radical-mediated C-H and C-C bond fluorination.Three types of transformations are discussed:(1)direct C-H abstraction/fluorination of alkanes;(2)decarboxylative fluorination of alkyl carboxylic acids;(3)ring-opening fluorination.
