Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-l...Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-light-promoted photoredox catalysis has emerged as a versatile platform for constructing quinoxalin-2(1H)-one scaffolds under exceptionally mild conditions.In this review,we provide an overview of recent advances in photocatalytic direct C(3)–H functionalization of quinoxaline-2(1H)-ones,including the construction of C(3)–C bonds and C(3)–R_(F)/C/O/N/Cl/S/D bonds,as well as the related reaction mechanisms.We aim to enhance the methods for the reaction of quinoxalin-2(1H)-ones at the C-3 position,which have extensive applications in organic synthesis and medicinal chemistry.展开更多
The adsorption of C atoms on the α-Fe2O3（001） surface was studied based on density function theory（DFT） ,in which the exchange-correlation potential was chosen as the PBE（Perdew,Burke and Ernzerhof） generalized...The adsorption of C atoms on the α-Fe2O3（001） surface was studied based on density function theory（DFT） ,in which the exchange-correlation potential was chosen as the PBE（Perdew,Burke and Ernzerhof） generalized gradient approximation（GGA） with a plane wave basis set. Upon the optimization on different adsorption sites with coverage of 1/20 and 1/5 ML,it was found that the adsorption of C atoms on the α-Fe2O3（001） surface was chemical adsorption. The coverage can affect the adsorption behavior greatly. Under low coverage,the most stable adsorption geometry lied on the bridged site with the adsorption energy of about 3.22 eV; however,under high coverage,it located at the top site with the energy change of 8.79 eV. Strong chemical reaction has occurred between the C and O atoms at this site. The density of states and population analysis showed that the s,p orbitals of C and p orbital of O give the most contribution to the adsorption bonding. During the adsorption process,O atom shares the electrons with C,and C can only affect the outermost and subsurface layers of α-Fe2O3; the third layer can not be affected obviously.展开更多
Objective: In this study, we assessed the level of fasting C-peptide as a predictor of β-cell function and insulin resistance in patients with Type 2 diabetes mellitus (T2DM), Gezira State-Sudan. Methods: In this cro...Objective: In this study, we assessed the level of fasting C-peptide as a predictor of β-cell function and insulin resistance in patients with Type 2 diabetes mellitus (T2DM), Gezira State-Sudan. Methods: In this cross-sectional study, 100 T2DM patients attending the Diabetic patients care Centre were recruited, thirty five patients were males and sixty five were females, the mean age of the patients was 50.29 ± 0.456 years, and body mass index (BMI) was 26.54 ± 0.437. We estimated β-cell function using fasting C-peptide levels;homeostatic model assessment for β-cell function (HOMA-B) and insulin resistance (HOMA-IR) were calculated from C-peptide and fasting blood glucose (FBG). Results: C-peptide was significantly and positively correlated with HOMA-B and HOMA-IR. FBG also showed significant negative correlation with HOMA-B, but was positively and significantly correlated with HOMA-IR. HbA1c was negatively and significantly correlated with HOMA-B. Patients with low C-peptide levels had increased FBG and HbA1c level, while patients with high C-peptide levels were having high HOMA-IR and HOMA-B. Conclusions: Fasting C-peptide is a useful marker of pancreatic β-cell function, and its circulating levels could be used to evaluate insulin secretion and insulin resistance. Moreover, HOMA-IR is an effective index to achieve glycemic control by appropriate pharmacologic treatment of T2DM.展开更多
High ce rvical spinal co rd injuries induce permanent neuromotor and autonomic deficits.These injuries impact both central respiratory and cardiovascular functions through modulation of the sympathetic nervous system....High ce rvical spinal co rd injuries induce permanent neuromotor and autonomic deficits.These injuries impact both central respiratory and cardiovascular functions through modulation of the sympathetic nervous system.So far,cardiovascular studies have focused on models of complete contusion or transection at the lower cervical and thoracic levels and diaphragm activity evaluations using invasive methods.The present study aimed to evaluate the impact of C2 hemisection on different parameters representing vital functions(i.e.,respiratory function,cardiovascular,and renal filtration parameters)at the moment of injury and 7 days post-injury in rats.No ventilatory parameters evaluated by plethys mography were impacted during quiet breathing after 7 days post-injury,whereas permanent diaphragm hemiplegia was observed by ultrasound and confirmed by diaphragmatic electromyography in anesthetized rats.Interestingly,the mean arterial pressure was reduced immediately after C2 hemisection,with complete compensation at 7 days post-injury.Renal filtration was unaffected at 7 days post-injury;however,remnant systolic dysfunction chara cterized by a reduced left ventricular ejection fraction persisted at 7 days post-injury.Taken together,these results demonstrated that following C2 hemisection,diaphragm activity and systolic function are impa cted up to 7 days post-injury,whereas the respiratory and cardiovascular systems display vast ada ptation to maintain ventilatory parameters and blood pressure homeostasis,with the latter likely sustained by the remaining descending sympathetic inputs spared by the initial injury.A better broad characterization of the physiopathology of high cervical spinal cord injuries covering a longer time period post-injury could be beneficial for understanding evaluations of putative therapeutics to further increase cardiorespiratory recovery.展开更多
The generalised gradient approximation based on density functional theory is used to study the structural and electronic properties of the endohedral fullerene dimer （N2@C60）2. Four N atoms sit at the cage centres i...The generalised gradient approximation based on density functional theory is used to study the structural and electronic properties of the endohedral fullerene dimer （N2@C60）2. Four N atoms sit at the cage centres in the form of two N2 molecules. The density of states and Mulliken charge analysis explore that the energy levels from 6 to 10 eV are mainly influenced by the N2 molecules.展开更多
A method of C（sp^3）-H bond functionalization of methyl azaarenes catalyzed by alumina-supported heteropoly acid and addition to isatins was developed. This transformation could be used for the synthesis of biologica...A method of C（sp^3）-H bond functionalization of methyl azaarenes catalyzed by alumina-supported heteropoly acid and addition to isatins was developed. This transformation could be used for the synthesis of biologically important 3-hydroxy-2-oxindole derivatives in good to excellent yields and the catalyst could be reused for six times without significant decrease in activity.展开更多
基金support from the National Natural Science Foundation of China(No.22101267)the China Postdoctoral Science Foundation(Nos.2021M692905 and 2024T170832)+2 种基金Natural Science Foundation of Henan Province,China(No.242300421123)Scientific Research Project of Hubei Provincial Education Department,China(No.Q20233104)Hubei Provincial Natural Science Foundation,China(No.2024AFB946).
文摘Quinoxalin-2(1H)-ones are unique nitrogen-containing organic compounds with wide applications in the agrochemical,pharmaceutical,and chemical industries as well as in material science.During the last decades,visible-light-promoted photoredox catalysis has emerged as a versatile platform for constructing quinoxalin-2(1H)-one scaffolds under exceptionally mild conditions.In this review,we provide an overview of recent advances in photocatalytic direct C(3)–H functionalization of quinoxaline-2(1H)-ones,including the construction of C(3)–C bonds and C(3)–R_(F)/C/O/N/Cl/S/D bonds,as well as the related reaction mechanisms.We aim to enhance the methods for the reaction of quinoxalin-2(1H)-ones at the C-3 position,which have extensive applications in organic synthesis and medicinal chemistry.
基金Project supported by the Foundation for Key Program of Ministry of Education (Nos.108033 and 107119)State Key Development Program for Basic Research of China (No.2009CB219801)+4 种基金the National High Technology Research and Development Program of China (No.2008AA05Z302)NNSFC (No.50976032)NSF of Beijing (No.3101001)the Specialized Basic Research Fund for Center Higher Education (No.09ZG03)Doctor Fund of North China Electric Power University (No.200822015)
文摘The adsorption of C atoms on the α-Fe2O3（001） surface was studied based on density function theory（DFT） ,in which the exchange-correlation potential was chosen as the PBE（Perdew,Burke and Ernzerhof） generalized gradient approximation（GGA） with a plane wave basis set. Upon the optimization on different adsorption sites with coverage of 1/20 and 1/5 ML,it was found that the adsorption of C atoms on the α-Fe2O3（001） surface was chemical adsorption. The coverage can affect the adsorption behavior greatly. Under low coverage,the most stable adsorption geometry lied on the bridged site with the adsorption energy of about 3.22 eV; however,under high coverage,it located at the top site with the energy change of 8.79 eV. Strong chemical reaction has occurred between the C and O atoms at this site. The density of states and population analysis showed that the s,p orbitals of C and p orbital of O give the most contribution to the adsorption bonding. During the adsorption process,O atom shares the electrons with C,and C can only affect the outermost and subsurface layers of α-Fe2O3; the third layer can not be affected obviously.
文摘Objective: In this study, we assessed the level of fasting C-peptide as a predictor of β-cell function and insulin resistance in patients with Type 2 diabetes mellitus (T2DM), Gezira State-Sudan. Methods: In this cross-sectional study, 100 T2DM patients attending the Diabetic patients care Centre were recruited, thirty five patients were males and sixty five were females, the mean age of the patients was 50.29 ± 0.456 years, and body mass index (BMI) was 26.54 ± 0.437. We estimated β-cell function using fasting C-peptide levels;homeostatic model assessment for β-cell function (HOMA-B) and insulin resistance (HOMA-IR) were calculated from C-peptide and fasting blood glucose (FBG). Results: C-peptide was significantly and positively correlated with HOMA-B and HOMA-IR. FBG also showed significant negative correlation with HOMA-B, but was positively and significantly correlated with HOMA-IR. HbA1c was negatively and significantly correlated with HOMA-B. Patients with low C-peptide levels had increased FBG and HbA1c level, while patients with high C-peptide levels were having high HOMA-IR and HOMA-B. Conclusions: Fasting C-peptide is a useful marker of pancreatic β-cell function, and its circulating levels could be used to evaluate insulin secretion and insulin resistance. Moreover, HOMA-IR is an effective index to achieve glycemic control by appropriate pharmacologic treatment of T2DM.
基金supported by funding from the Chancellerie des Universites de Paris(Legs Poix)(to SV)Fondation Medisite(to SV)+1 种基金INSERM(to SV,AM,AF)Universite de Versailles Saint-Quentin-en-Yvelines(to SV,AM,AF)。
文摘High ce rvical spinal co rd injuries induce permanent neuromotor and autonomic deficits.These injuries impact both central respiratory and cardiovascular functions through modulation of the sympathetic nervous system.So far,cardiovascular studies have focused on models of complete contusion or transection at the lower cervical and thoracic levels and diaphragm activity evaluations using invasive methods.The present study aimed to evaluate the impact of C2 hemisection on different parameters representing vital functions(i.e.,respiratory function,cardiovascular,and renal filtration parameters)at the moment of injury and 7 days post-injury in rats.No ventilatory parameters evaluated by plethys mography were impacted during quiet breathing after 7 days post-injury,whereas permanent diaphragm hemiplegia was observed by ultrasound and confirmed by diaphragmatic electromyography in anesthetized rats.Interestingly,the mean arterial pressure was reduced immediately after C2 hemisection,with complete compensation at 7 days post-injury.Renal filtration was unaffected at 7 days post-injury;however,remnant systolic dysfunction chara cterized by a reduced left ventricular ejection fraction persisted at 7 days post-injury.Taken together,these results demonstrated that following C2 hemisection,diaphragm activity and systolic function are impa cted up to 7 days post-injury,whereas the respiratory and cardiovascular systems display vast ada ptation to maintain ventilatory parameters and blood pressure homeostasis,with the latter likely sustained by the remaining descending sympathetic inputs spared by the initial injury.A better broad characterization of the physiopathology of high cervical spinal cord injuries covering a longer time period post-injury could be beneficial for understanding evaluations of putative therapeutics to further increase cardiorespiratory recovery.
基金Project supported by the Special Foundation of National Natural Science (Grant No. 10947132)the Fundamental Research Funds for the Central Universities,the Research Starting Foundation of Hohai University (Grant No. 2084/40801130)+1 种基金the Natural Science Foundation of Hohai University (Grant Nos. 2008431211 and 2008430311)the Excellent Innovation Personal Support Plan of Hohai University
文摘The generalised gradient approximation based on density functional theory is used to study the structural and electronic properties of the endohedral fullerene dimer （N2@C60）2. Four N atoms sit at the cage centres in the form of two N2 molecules. The density of states and Mulliken charge analysis explore that the energy levels from 6 to 10 eV are mainly influenced by the N2 molecules.
基金Financial support from the National Natural Science Foundation of China(No.21402103)the research fund of Qingdao Agricultural University's High-level Person(No.631303)the Scientific Research Foundation of Shandong Province Outstanding Young Scientist Award(No.BS2013YY024) were gratefully acknowledged
文摘A method of C（sp^3）-H bond functionalization of methyl azaarenes catalyzed by alumina-supported heteropoly acid and addition to isatins was developed. This transformation could be used for the synthesis of biologically important 3-hydroxy-2-oxindole derivatives in good to excellent yields and the catalyst could be reused for six times without significant decrease in activity.
基金Project supported by the Department of Henan Province Natural Science and Technology Foundation(Nos.172102210225 and 182102310675)the Natural Science Foundation in Henan Province Department of Education(No.17A150005)+1 种基金the Program for Innovative Research Team from Zhengzhou(No.131PCXTD605)the Project of Youth Backbone Teachers of Henan University of Technology(No.2016003)~~
