Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of s...Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.展开更多
Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize th...Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.展开更多
The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the infl...The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the influences of indicators,contexts,and scales.Yet,another potential factor,which has been overlooked,may be the mixed use of spatial and temporal approaches.Using twelve ES and seven well-being indicators and multiple statistical methods,we quantified and compared the spatial and temporal ES–HWB relationships for Inner Mongolia,China.The spatial and temporal relationships differed in both correlation direction and strength.Most relationships of economic and employment-related indicators with food provisioning and supporting services were temporally positive but spatially nonsignificant or negative.Some relationships of economic and employmentrelated indicators with water retention,sandstorm prevention,and wind erosion were temporally negative but spatially complex.However,the spatial and temporal ES–HWB relationships could also be similar in some cases.We conclude that although both the spatial and temporal approaches have merits,space generally cannot substitute for time in the study of ES–HWB relationship.Our study helps reconcile the seemingly conflicting findings in the literature,and suggests that future studies should explicitly distinguish between the spatial and temporal ES–HWB relationships.展开更多
P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still...P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still not satisfactory.In this work,we design a new quaternary manganese-iron-based cathode material(P3-Na_(0.54)Mn_(0.64)Fe_(_(0.1)6)Mg_(0.1)Cu_(0.1)O_(2))by Cu substitution.The strong covalent Cu-O bonds improve the structural stability and the reversibility of O redox during charge and discharge processes.Cu substitution also mitigates the structure change with less unit cell volume variation,and improves the Na-ion transport kinetics effectively.As a result,NMFMC delivers much improved cycling stability and rate capability compared with NMFM.It reveals that the charge compensation of NMFMC is mainly contributed by Mn^(3+/4+),Fe^(3+/3.5+)and O_(2-/-)during the charge and discharge processes,and Cu substitution can also enhance the activity and reversibility of Fe redox.This strategy provides a new pathway toward improving the stability and O redox reversibility of P3-type cathode materials for sodium-ion batteries.展开更多
Isomorphic substitution of ferric ion(Fe~(3+))by aluminum ion(Al~(3+))in iron(hydro)oxides is ubiquitous in natural environments.Aluminum substitution inevitably leads to changes in the microstructures,physicochemical...Isomorphic substitution of ferric ion(Fe~(3+))by aluminum ion(Al~(3+))in iron(hydro)oxides is ubiquitous in natural environments.Aluminum substitution inevitably leads to changes in the microstructures,physicochemical properties,and surface reactions of iron(hydro)oxides,which may have great impacts on the sequestration of nutrients and contaminants in soils and aquatic environments.Over the past decades,the structural properties and surface reactivity of Al-substituted iron(hydro)oxides have been intensively studied.Iron(hydro)oxides in various structural forms and with different Al substitution amounts present high application potentials in addressing environmental issues.A timely summary of the structural properties and interfacial reactions of the most common and representative Al-substituted iron(hydro)oxides is of significance.Herein,the effects of Al substitution on the structural properties and surface activities of iron(hydro)oxides were clarified according to the microstructure,crystal facets,surface site type and density,interfacial reaction mechanisms,and modeling parameters of iron(hydro)oxides.This review systematically elucidates how Al substitution affects the structural properties and surface reactions of iron(hydro)oxides,including the well crystallized goethite and hematite and the poorly crystallized ferrihydrite,providing theoretical guidance for further exploration of the mineralogical characteristics and environmental geochemical behaviors of iron(hydro)oxides.展开更多
Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials ...Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.展开更多
In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with wh...In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with whole egg group(WE),HFD with free-yolk egg substitute group(YFES),and HFD with lovastatin group(Lov).Main biochemical indexes and a non-targeted lipidomic analysis were employed to insight the lipid profile changes in serum.It was revealed that WE could significantly improve serum biochemical indexes by reducing body weight,low-density lipoprotein cholesterol(LDL-C)and total cholesterol(TC),while increasing high-density lipoprotein cholesterol.YFES exhibited remarkably better performance in increasing phosphatidylglycerol and phosphatidic acids,while decreasing phosphatidylinositol than WE.A total of 50 differential lipids biomarkers tightly related to glycerophospholipids metabolism were screened out.Carnitine C18:2 and C12:1,SM(d18:0/12:0),and SM(d18:1/14:1)were significantly upregulated in YFES compared to WE.YFES reduced expression of SREBP-1c and Cpt1a,while did not affect the expression of PPAR-α.Sphingomyelin biomarkers were positively related to the TC(|r|>0.6),while PPAR-αwas negatively correlated with triglyceride and LDL-C levels.To sum up,YFES attenuated HFD-induced Met S by improving the serum phospholipids,which account for its modulation of glycerophospholipid metabolism.展开更多
The shortage of transplantable skin is the leading cause of death in patients with extensive skin defect.Addressing this challenge urgently requires the development of skin substitutes capable of wound repair and faci...The shortage of transplantable skin is the leading cause of death in patients with extensive skin defect.Addressing this challenge urgently requires the development of skin substitutes capable of wound repair and facilitating skin regeneration.In this study,a biomimetic bilayer skin tissue model consisting of collagen,gelatin/sodium alginate,fibroblasts,human umbilical vein endothelial cells,keratinocytes,melanocytes,and verteporfin was devised.Then,the skin model was fabricated using precise extrusion/inkjet bioprinters,and it reconstruction capabilities were evaluated through skin defect repair experiments.The printed skin tissue reduced the inflammatory response of the wound by 38%and inhibited the expression of TGF-βand YAP,and promoted the transformation of macrophages from M1 phenotype to M2 phenotype,thus promoting the reasonable reconstruction of fibronectin and collagen on the wound,finally promoting the wound healing,and reducing the wound contraction and scar formation.In addition,the proliferation and differentiation of human umbilical vein endothelial cells,keratinocytes,and melanocytes in printed skin increased the number of regenerated blood vessels by 123%,while promoting the reconstruction of multilayer epidermal structure and skin color.The outcomes of this investigation present a promising skin model and therapeutic strategy for skin injury,offering a potential avenue for the reconstruction of skin structure and function.展开更多
We reported the earliest cases involving electrostatic spinning synthetic dura substitutes for repairing defects in the spinal dura mater. From June to September 2017, seven patients were treated with electrostatic sp...We reported the earliest cases involving electrostatic spinning synthetic dura substitutes for repairing defects in the spinal dura mater. From June to September 2017, seven patients were treated with electrostatic spinning synthetic dura substitute. The laminotomy was performed for all the patients, and the cancers were resected, then the electrostatic spinning synthetic dura substitute made of polylactic acid ReDuraTM. All of the patients had no complications and might be the ideal promising alternative for repairing the spinal dura mater.展开更多
Compared to organic thin films,organic single crystals offer significant potential in organic phototransistors(OPTs)due to their enhanced charge transport,large surface area,and defect-free nature.However,the developm...Compared to organic thin films,organic single crystals offer significant potential in organic phototransistors(OPTs)due to their enhanced charge transport,large surface area,and defect-free nature.However,the development of n-type semiconductors has lagged behind p-type semiconductors.To enhance semiconductor device performance,a doping process can be employed,which typically involves the introduction of charged impurities into the crystalline semiconducting material.Its aim is to reduce the Ohmic losses,increase carrier density,improve transport capabilities,and facilitate effective carrier injection,ultimately enhancing the electrical properties of the material.Traditional doping processes,however,often pose a risk of damaging the structure of single crystals.In this study,we have synthesized novel cyanosubstituted chiral perylene diimides,which self-assemble into two-dimensional single crystals that can be used for n-type semiconductor devices.We have employed a surface doping strategy using diethylamine vapor without disrupting the crystal structure.The fabricated devices exhibit significantly higher charge transport properties after doping,achieving a maximum electron mobility of 0.14 cm^(2)V^(-1)s^(-1),representing an improvement of over threefold.Furthermore,the optoelectronic performance of the doped devices has significantly improved,with the external quantum efficiency increased by over 9 times and the significantly improved response time.These results suggest that our surface doping technology is a promising way for enhancing the performance of 2D organic single-crystal OPTs.展开更多
Quantum chemical calculations were used to estimate the bond dissociation energies （BDEs） for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory （B3LYP, B3P...Quantum chemical calculations were used to estimate the bond dissociation energies （BDEs） for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory （B3LYP, B3PW91, B3P86） methods together with 6-31G^＊＊ and 6-311G^＊＊ basis sets. The results show that B3P86/6-311G^＊＊ method is the best method to compute the reliable BDEs for substituted chlorobenzene compounds which contain the C-C1 bond. It is found that the C-C1 BDE depends strongly on the computational method and the basis sets used. Substituent effect on the C-C1 BDE of substituted chlorobenzene compounds is further discussed. It is noted that the effects of substitution on the C-C1 BDE of substituted chlorobenzene compounds are very insignificant. The energy gaps between the HOMO and LUMO of studied compounds estimate the relative thermal stability ordering are also investigated and from this data we of substituted chlorobenzene compounds.展开更多
The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides a...The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.展开更多
Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carbo...Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model.展开更多
A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through t...A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through the efficient sequence of acylation, nitration, reduction, intramolecular alkylation, and oxidation.展开更多
An efficient regioselective Friedel-Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed. The reactions proceeded smoothly at room temperature and the 2-hy...An efficient regioselective Friedel-Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed. The reactions proceeded smoothly at room temperature and the 2-hydroxy-2-（1H-indol-3-yl）-N-substituted acetamide resulted from the reactions catalyzed by FeSO4 were synthesized in excellent yields （up to 93%）. While the bisindole compounds were obtained when FeCl3 was used as a catalyst in excellent yields （up to 92%）. A possible mechanism was proposed.展开更多
The seleno substituted aromatic compounds were prepared via the Diels-Alder reaction of seleno substituted 3-sulfolenes with dimethyl acetylenedicarboxylate followed by DDQ dehydrogenation.
An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The...An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ？2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （D...[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.展开更多
The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone...The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone oil, heavy silicone oil and hydrogels, particularly the former two vitreous substitutes are clinically widely used with certain complications. Those, however, are not real artificial vitreous due to lack of structure and function like the natural vitreous body. This article reviews the situations, challenges, and future directions in the development of vitreous substitutes, particularly the experimental and clinical use of a new artificial foldable capsular vitreous body.展开更多
A novel method to prepare guanidine substituted aminoglycoside derivatives was developed.Free guanidine reacted with Cbz-protected aminoglycosides to produce guanidinylcarbonyl substituted derivatives.A methoxycarbony...A novel method to prepare guanidine substituted aminoglycoside derivatives was developed.Free guanidine reacted with Cbz-protected aminoglycosides to produce guanidinylcarbonyl substituted derivatives.A methoxycarbonyl-protected intermediate was isolated,and the mechanism of guanidinylcarbonyl modification was proposed.With this method,six per- or part-guanidylcarbonyl substituted aminoglycosides were successfully obtained in good yields.Their in vitro antibacterial activities were essayed.展开更多
基金supported by the‘Korea National Institute of Health’(KNIH)research project(Project No.2022ER130502)the National Research Foundation of Korea(NRF)Grant funded by the Korea Government(MSIT)(No.2021R1A2C20060331222182102840102)。
文摘Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.
基金Projects(52274108,U2341265)supported by the National Natural Science Foundation of ChinaProject(2022YFC2904103)supported by the National Key Research and Development Program of China。
文摘Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.B240201068)the National Natural Science Foundation of China(Grant No.42361144861)the National Basic Research Program of China(Grant No.2014CB954303).
文摘The relationship between ecosystem services(ES)and human well-being(HWB)is fundamental to the science and practice of sustainability.However,studies have shown conflicting results,which has been attributed to the influences of indicators,contexts,and scales.Yet,another potential factor,which has been overlooked,may be the mixed use of spatial and temporal approaches.Using twelve ES and seven well-being indicators and multiple statistical methods,we quantified and compared the spatial and temporal ES–HWB relationships for Inner Mongolia,China.The spatial and temporal relationships differed in both correlation direction and strength.Most relationships of economic and employment-related indicators with food provisioning and supporting services were temporally positive but spatially nonsignificant or negative.Some relationships of economic and employmentrelated indicators with water retention,sandstorm prevention,and wind erosion were temporally negative but spatially complex.However,the spatial and temporal ES–HWB relationships could also be similar in some cases.We conclude that although both the spatial and temporal approaches have merits,space generally cannot substitute for time in the study of ES–HWB relationship.Our study helps reconcile the seemingly conflicting findings in the literature,and suggests that future studies should explicitly distinguish between the spatial and temporal ES–HWB relationships.
基金supported by the National Key Scientific Research Project(No.2022YFB2502300)the National Natural Science Foundation of China(No.52071085).
文摘P3-type manganese-iron-based cathodes with high specific capacity and abundant resource have attracted considerable attention for sodium-ion batteries.However,the long-term cycle stability of P3-type cathodes is still not satisfactory.In this work,we design a new quaternary manganese-iron-based cathode material(P3-Na_(0.54)Mn_(0.64)Fe_(_(0.1)6)Mg_(0.1)Cu_(0.1)O_(2))by Cu substitution.The strong covalent Cu-O bonds improve the structural stability and the reversibility of O redox during charge and discharge processes.Cu substitution also mitigates the structure change with less unit cell volume variation,and improves the Na-ion transport kinetics effectively.As a result,NMFMC delivers much improved cycling stability and rate capability compared with NMFM.It reveals that the charge compensation of NMFMC is mainly contributed by Mn^(3+/4+),Fe^(3+/3.5+)and O_(2-/-)during the charge and discharge processes,and Cu substitution can also enhance the activity and reversibility of Fe redox.This strategy provides a new pathway toward improving the stability and O redox reversibility of P3-type cathode materials for sodium-ion batteries.
基金financially supported by the National Natural Science Foundation of China(Nos.42207352,42007020,and 42007015)the Natural Science Fund for Excellent Young Scholars of Hainan Province,China(No.324YXQN421)。
文摘Isomorphic substitution of ferric ion(Fe~(3+))by aluminum ion(Al~(3+))in iron(hydro)oxides is ubiquitous in natural environments.Aluminum substitution inevitably leads to changes in the microstructures,physicochemical properties,and surface reactions of iron(hydro)oxides,which may have great impacts on the sequestration of nutrients and contaminants in soils and aquatic environments.Over the past decades,the structural properties and surface reactivity of Al-substituted iron(hydro)oxides have been intensively studied.Iron(hydro)oxides in various structural forms and with different Al substitution amounts present high application potentials in addressing environmental issues.A timely summary of the structural properties and interfacial reactions of the most common and representative Al-substituted iron(hydro)oxides is of significance.Herein,the effects of Al substitution on the structural properties and surface activities of iron(hydro)oxides were clarified according to the microstructure,crystal facets,surface site type and density,interfacial reaction mechanisms,and modeling parameters of iron(hydro)oxides.This review systematically elucidates how Al substitution affects the structural properties and surface reactions of iron(hydro)oxides,including the well crystallized goethite and hematite and the poorly crystallized ferrihydrite,providing theoretical guidance for further exploration of the mineralogical characteristics and environmental geochemical behaviors of iron(hydro)oxides.
基金financially supported by the Scientific and Technological Plan Project of Guizhou Province ([2024]054)Additional support came from the Industry and Education Combination Innovation Platform of Intelligent Manufacturing and Graduate Joint Training Base at Guizhou University (2020-520000-83-01324061)the Guizhou Engineering Research Center for Smart Services (2203-520102-04-04-298868)。
文摘Aqueous sodium-ion batteries(ASIBs) offer significant advantages for energy storage on a large scale,attributed to their economical cost,secure operatio n,and eco-friend ly natu re.Among the leading cathode materials for ASIBs,Na_(3)V_(2)(PO_(4))_(3)(NVP) exhibits excellent structural stability and a high Na+diffusion coefficient,making it a promising option.However,the high solubility of vanadium-based materials in aqueous electrolytes engenders suboptimal cycling stability for Na_(3)V_(2)(PO_(4))_(3),constraining its application in ASIBs.Herein,the Cr-substituted Na_(3)V_(1.3)Cr_(0.7)(PO_(4))3@C(NV_(1.3)Cr_(0.7)P) cathode material was synthesized via a simple sol-gel method.It is found that Cr substitution reduces the cell parameters of NV_(1.3)Cr_(0.7)P,effectively reinforcing the crystal structure.Furthermore,NV_(1.3)Cr_(0.7)P alters the Na^(+)insertion/extraction mechanism,transforming the typical two-phase reaction between Na_(1)V_(2)(PO_(4))_(3)and Na_(3)V_(2)(PO_(4))3into continuous solid-solution reactions with stable intermediates.The Cr substitution diminishes the sodium-ion diffusion energy barrier in NV_(1.3)Cr_(0.7)P,leading to smoother Na+insertion and extraction processes.Consequently,NV_(1.3)Cr_(0.7)P exhibits impressive cycling stability,retaining 74.8% of its capacity after 5,000 cycles at a current density of 5 A g^(-1),along with an outstanding rate performance of 79,2% at 10 A g^(-1).This work elucidates the stable Na^(+)insertion/extraction processes in Cr-substituted NV_(1.3)Cr_(0.7)P,offering insights into the application of vanadium-based materials in aqueous sodium-ion batteries.
基金supported by the Applied Basic Research of Shanxi Province(201901D211381)the Innovation-driven Development Capacity Enhancement Fund of Shanxi Province(SXYBKY2019041)+2 种基金National Key Research and Development Program(2021YFD1600604-03)Shanxi Scholarship Council of China(2021-068)Shanxi Agricultural University High-Level Talent Project(2021XG013)。
文摘In this study,the impacts of egg consumption on mice model of metabolic syndrome(Met S)were comparatively investigated.Mice were divided into five groups(n=8):normal diet group(ND),high-fat diet group(HFD),HFD with whole egg group(WE),HFD with free-yolk egg substitute group(YFES),and HFD with lovastatin group(Lov).Main biochemical indexes and a non-targeted lipidomic analysis were employed to insight the lipid profile changes in serum.It was revealed that WE could significantly improve serum biochemical indexes by reducing body weight,low-density lipoprotein cholesterol(LDL-C)and total cholesterol(TC),while increasing high-density lipoprotein cholesterol.YFES exhibited remarkably better performance in increasing phosphatidylglycerol and phosphatidic acids,while decreasing phosphatidylinositol than WE.A total of 50 differential lipids biomarkers tightly related to glycerophospholipids metabolism were screened out.Carnitine C18:2 and C12:1,SM(d18:0/12:0),and SM(d18:1/14:1)were significantly upregulated in YFES compared to WE.YFES reduced expression of SREBP-1c and Cpt1a,while did not affect the expression of PPAR-α.Sphingomyelin biomarkers were positively related to the TC(|r|>0.6),while PPAR-αwas negatively correlated with triglyceride and LDL-C levels.To sum up,YFES attenuated HFD-induced Met S by improving the serum phospholipids,which account for its modulation of glycerophospholipid metabolism.
基金funded by Nanyang Normal University Natural Science Doctor Research Starting Fund Project,2024ZX026,Tian Jiao。
文摘The shortage of transplantable skin is the leading cause of death in patients with extensive skin defect.Addressing this challenge urgently requires the development of skin substitutes capable of wound repair and facilitating skin regeneration.In this study,a biomimetic bilayer skin tissue model consisting of collagen,gelatin/sodium alginate,fibroblasts,human umbilical vein endothelial cells,keratinocytes,melanocytes,and verteporfin was devised.Then,the skin model was fabricated using precise extrusion/inkjet bioprinters,and it reconstruction capabilities were evaluated through skin defect repair experiments.The printed skin tissue reduced the inflammatory response of the wound by 38%and inhibited the expression of TGF-βand YAP,and promoted the transformation of macrophages from M1 phenotype to M2 phenotype,thus promoting the reasonable reconstruction of fibronectin and collagen on the wound,finally promoting the wound healing,and reducing the wound contraction and scar formation.In addition,the proliferation and differentiation of human umbilical vein endothelial cells,keratinocytes,and melanocytes in printed skin increased the number of regenerated blood vessels by 123%,while promoting the reconstruction of multilayer epidermal structure and skin color.The outcomes of this investigation present a promising skin model and therapeutic strategy for skin injury,offering a potential avenue for the reconstruction of skin structure and function.
文摘We reported the earliest cases involving electrostatic spinning synthetic dura substitutes for repairing defects in the spinal dura mater. From June to September 2017, seven patients were treated with electrostatic spinning synthetic dura substitute. The laminotomy was performed for all the patients, and the cancers were resected, then the electrostatic spinning synthetic dura substitute made of polylactic acid ReDuraTM. All of the patients had no complications and might be the ideal promising alternative for repairing the spinal dura mater.
基金supported by the National Research Foundation(NRF)of Korea(Nos.2023R1A2C3007715,2021R1A4A1032515,RS-2023-00281944)funded by the Ministry of Science and ICT(MSIT)of Korea+1 种基金Korea Toray Science Foundation,Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHQ035)Natural Science Basic Research Program of Shaanxi Province(No.2024JC-YBMS-081)。
文摘Compared to organic thin films,organic single crystals offer significant potential in organic phototransistors(OPTs)due to their enhanced charge transport,large surface area,and defect-free nature.However,the development of n-type semiconductors has lagged behind p-type semiconductors.To enhance semiconductor device performance,a doping process can be employed,which typically involves the introduction of charged impurities into the crystalline semiconducting material.Its aim is to reduce the Ohmic losses,increase carrier density,improve transport capabilities,and facilitate effective carrier injection,ultimately enhancing the electrical properties of the material.Traditional doping processes,however,often pose a risk of damaging the structure of single crystals.In this study,we have synthesized novel cyanosubstituted chiral perylene diimides,which self-assemble into two-dimensional single crystals that can be used for n-type semiconductor devices.We have employed a surface doping strategy using diethylamine vapor without disrupting the crystal structure.The fabricated devices exhibit significantly higher charge transport properties after doping,achieving a maximum electron mobility of 0.14 cm^(2)V^(-1)s^(-1),representing an improvement of over threefold.Furthermore,the optoelectronic performance of the doped devices has significantly improved,with the external quantum efficiency increased by over 9 times and the significantly improved response time.These results suggest that our surface doping technology is a promising way for enhancing the performance of 2D organic single-crystal OPTs.
基金This work was supported by the National Natural Science Foundation of China （No.10774039）.
文摘Quantum chemical calculations were used to estimate the bond dissociation energies （BDEs） for 13 substituted chlorobenzene compounds. These compounds were studied by the hybrid density functional theory （B3LYP, B3PW91, B3P86） methods together with 6-31G^＊＊ and 6-311G^＊＊ basis sets. The results show that B3P86/6-311G^＊＊ method is the best method to compute the reliable BDEs for substituted chlorobenzene compounds which contain the C-C1 bond. It is found that the C-C1 BDE depends strongly on the computational method and the basis sets used. Substituent effect on the C-C1 BDE of substituted chlorobenzene compounds is further discussed. It is noted that the effects of substitution on the C-C1 BDE of substituted chlorobenzene compounds are very insignificant. The energy gaps between the HOMO and LUMO of studied compounds estimate the relative thermal stability ordering are also investigated and from this data we of substituted chlorobenzene compounds.
文摘The thermal Claisen rearrangement of O-allyl substituted isotetronic acids 1 was successfully carried out within a glass microreactor operated with temperature at 150℃and a flow rate of 1 mL/h.The strategy provides an efficient alternative way toβ-allyl substituted isotetronic acid derivatives 2 in high yields with much accelerated reaction speed.
文摘Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model.
文摘A novel approach to the synthesis of 6, 7-disubstituted-1H-quinoxalin-2-ones is described.The title compounds were regioselectively prepared by starting from substituted phenylamines andchloroacetyl chloride through the efficient sequence of acylation, nitration, reduction, intramolecular alkylation, and oxidation.
基金the National Natural Science Foundation of China (Nos. 21472130, 81373259) for financial support of this study
文摘An efficient regioselective Friedel-Crafts hydroxyalkylation of N-substituted glyoxylamide with various indoles catalyzed by Lewis acids was developed. The reactions proceeded smoothly at room temperature and the 2-hydroxy-2-（1H-indol-3-yl）-N-substituted acetamide resulted from the reactions catalyzed by FeSO4 were synthesized in excellent yields （up to 93%）. While the bisindole compounds were obtained when FeCl3 was used as a catalyst in excellent yields （up to 92%）. A possible mechanism was proposed.
文摘The seleno substituted aromatic compounds were prepared via the Diels-Alder reaction of seleno substituted 3-sulfolenes with dimethyl acetylenedicarboxylate followed by DDQ dehydrogenation.
文摘An efficient synthesis of 3,4-dihydropyrimidine 2 （1H）-ones and thiones （3,4-DHPMs） core was prepared by one-pot threecomponent Biginelli condensation and which was catalyzed by trifluoromethane sulfonic acid. The classical BigneUi reaction has been extended by the use of N-substituted benzoxazolyl semicarbazides and thiosemicarbazides and this method has the advantage of excellent yields and short reaction times. ？2009 M. Saranga Pard. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金Supported by Shanghai Leading Academic Discipline(Project No.T1102)Shanghai Commission of Education Scientific Research Project(07zz134)~~
文摘[Objective] In order to study the relations among different positions, degrees of substitution and antioxidant ability. [Method] N, O-carboxymethyl chitosan （NOA, NOB and NOC）with various degrees of substitution （DS）were obtained by etherizing chito-oligosacchaside. Their structure and substituted degree were characterized and their antioxldant activity to·OH was evaluated. [ Result] The IC50 s of NOA ,NOB and NOC were 0.15 ,0. 29 ,0. 23 mg/ml while their DSs of -NH2 position（DSN） were 0.51,0.29 and 0.38 and DSo were 0. 74 ,0. 84 ,0. 97respectively.[ Conclusion] With the increase of DSN ,antioxidant activity of N,O-carboxymethyl chitosan oligosaccharide to·OH was up.
基金Supported by the "Twelfth Five-Year" Plan for Science & Technology Support Grant (No. 2012BAI08B02)the National 863 Project (No. 2009AA02Z404)the Guangdong Provincial Industry University Research Cooperation Plan (No. 2010A090200074)
文摘The natural vitreous body has a fine structure and complex functions. The imitation of the natural vitreous body by vitreous substitutes is a challenging work for both researchers and ophthalmologists. Gases, silicone oil, heavy silicone oil and hydrogels, particularly the former two vitreous substitutes are clinically widely used with certain complications. Those, however, are not real artificial vitreous due to lack of structure and function like the natural vitreous body. This article reviews the situations, challenges, and future directions in the development of vitreous substitutes, particularly the experimental and clinical use of a new artificial foldable capsular vitreous body.
基金National Basic Research Program(973 Program, Grant No.2004CB518904)the State New Drug Innovation (Grant No.2009ZX09301-010,2009ZX09103 -044).
文摘A novel method to prepare guanidine substituted aminoglycoside derivatives was developed.Free guanidine reacted with Cbz-protected aminoglycosides to produce guanidinylcarbonyl substituted derivatives.A methoxycarbonyl-protected intermediate was isolated,and the mechanism of guanidinylcarbonyl modification was proposed.With this method,six per- or part-guanidylcarbonyl substituted aminoglycosides were successfully obtained in good yields.Their in vitro antibacterial activities were essayed.
