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
BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes of...BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes offer advantages including reduced donor site morbidity.Our meta-analysis evaluated the comparative efficacy of these approaches across clinical and operative outcomes.AIM To conduct a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.METHODS We conducted a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.Primary outcomes included joint depression,secondary collapse rate,operative time,blood loss,and infection rate.Subgroup analyses were performed by fracture complexity,geographic region,and methodological factors.In addition to that,we also developed a combined outcome score integrating structural,procedural,and complication domains.RESULTS Seven randomized controlled trials with 424 patients(296 bone substitute,128 autograft)were included.No significant differences in joint depression or secondary collapse were observed across fracture complexity categories.Geographic variations were evident,with Western studies showing significantly higher risk of secondary collapse with autografts(risk ratio=1.45,P value=0.02).Both Western and Asian studies have demonstrated significantly reduced blood loss with bone substitutes(70-90 mL less),while operative time reduction was more significant in the Asian studies(23.65 vs 8.00 minutes,P value=0.04 for subgroup difference).The combined outcome score(standardized effect size-0.2481)favored bone substitutes,primarily due to procedural advantages.CONCLUSION Bone substitutes provide similar structural outcomes to autologous bone grafts while having better procedural advantages in tibial plateau fracture management.These findings support bone substitutes as a viable option across fracture patterns.Future studies should focus on specific bone substitute formulations and cost-effectiveness analyses.展开更多
Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive com...Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive complex operations and inherent safety risks from centralized production.The direct synthesis route from H_(2) coupled with O_(2) presents a promising alternative,but remains constrained by the safety requirement and the reaction control demand.This article systematically reviews breakthroughs in non-hydrogen catalytic systems for in situ synthesis of H_(2)O_(2).Through elucidating the mechanism of two-electron oxygen reduction pathways,renewable hydrogen substitutes with enhanced safety including CO,HCOOH,glucose and alcohols have been highlighted.Their efficient conversion of O_(2) to H_(2)O_(2) and the integration with sustainable processes such as selective oxidation are also discussed.It is expected to provide fundamental insights into the synergistic mechanism in heterogeneous catalysis and offer a new viewpoint for developing a decentralized H_(2)O_(2) synthesis system for practical applications,moving toward a greener and more economical H_(2)O_(2) production approach.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
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
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
Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in lives...Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in livestock production.We aimed to perform a meta-analysis and network meta-analysis(NMA)to investigate the effects of feed additives as potential antibiotic substitutes(ASs)on bacteriostasis,growth performance,intestinal morphology and immunity.Furthermore,the primary,secondary,and tertiary ASs were defined by comparing their results with the results of antibiotics.Results:Among 16,309 identified studies,37 were summarized to study the bacteriostasis effects of feed additives,and 89 were included in the meta-analysis and NMA(10,228 pigs).We summarized 268 associations of 57 interventions with 32 bacteria.The order of bacteriostasis effects was as follows:antimicrobial peptides(AMPs)≈antibiotics>organic acids>plant extracts>oligosaccharides.We detected associations of 11 feed additives and 11 outcomes.Compared with a basal diet,plant extract,AMPs,probiotics,microelements,organic acids,bacteriophages,lysozyme,zymin,and oligosaccharides significantly improved growth performance(P<0.05);organic acids,probiotics,microelements,lysozyme,and AMPs remarkably increased the villus height:crypt depth ratio(V/C)(P<0.05);and plant extracts,zymin,microelements,probiotics,and organic acids notably improved immunity(P<0.05).The optimal AMP,bacteriophage,lysozyme,microelements,oligosaccharides,organic acids,plants,plant extracts,probiotics,and zymin doses were 0.100%,0.150%,0.012%,0.010%,0.050%,0.750%,0.20%,0.040%,0.180%,and 0.100%,respectively.Compared with antibiotics,all investigated feed additives exhibited no significant difference in effects on growth performance,IgG,and diarrhoea index/rate(P>0.05);AMPs and microelements significantly increased V/C(P<0.05);and zymin significantly improved lymphocyte levels(P<0.05).Furthermore,linear weighting sum models were used to comprehensively estimate the overall impact of each feed additive on pig growth and health.Conclusions:Our findings suggest that AMPs and plant extracts can be used as primary ASs for weaned piglets and growing pigs,respectively.Bacteriophages,zymin,plants,probiotics,oligosaccharides,lysozyme,and microelements can be regarded as secondary ASs.Nucleotides and organic acids can be considered as tertiary ASs.Future studies should further assess the alternative effects of combinational feed additives.展开更多
A study was conducted to evaluate the effects of meat and bone meal （MBM） and poultry by-product meal （PBM） as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibilit...A study was conducted to evaluate the effects of meat and bone meal （MBM） and poultry by-product meal （PBM） as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient （ADC） of Japanese flounder （Paralichthys olivaceus）. The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences （P 〉0.05） in growth performance among the treatments fed with 0% -60% MBM replacement of fishmeal, while the percent weight gain （WG, % ）, body length gain （BLG, % ） and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences （P 〉0.05） in growth performance and ADC among all treatments fed with the diets with 0% -80% replacements of fishmeal with PBM.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.
文摘BACKGROUND Tibial plateau fractures often require structural support for metaphyseal defects created during articular reduction.While autologous bone grafting has been utilized as the gold standard,bone substitutes offer advantages including reduced donor site morbidity.Our meta-analysis evaluated the comparative efficacy of these approaches across clinical and operative outcomes.AIM To conduct a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.METHODS We conducted a systematic review and meta-analysis of randomized controlled trials comparing autologous bone grafts with bone substitutes for tibial plateau fractures.Primary outcomes included joint depression,secondary collapse rate,operative time,blood loss,and infection rate.Subgroup analyses were performed by fracture complexity,geographic region,and methodological factors.In addition to that,we also developed a combined outcome score integrating structural,procedural,and complication domains.RESULTS Seven randomized controlled trials with 424 patients(296 bone substitute,128 autograft)were included.No significant differences in joint depression or secondary collapse were observed across fracture complexity categories.Geographic variations were evident,with Western studies showing significantly higher risk of secondary collapse with autografts(risk ratio=1.45,P value=0.02).Both Western and Asian studies have demonstrated significantly reduced blood loss with bone substitutes(70-90 mL less),while operative time reduction was more significant in the Asian studies(23.65 vs 8.00 minutes,P value=0.04 for subgroup difference).The combined outcome score(standardized effect size-0.2481)favored bone substitutes,primarily due to procedural advantages.CONCLUSION Bone substitutes provide similar structural outcomes to autologous bone grafts while having better procedural advantages in tibial plateau fracture management.These findings support bone substitutes as a viable option across fracture patterns.Future studies should focus on specific bone substitute formulations and cost-effectiveness analyses.
基金the National Natural Science Foundation of China(22125202,92461312,U24A20487,22302091,92361201)Natural Science Foundation of Jiangsu Province(BK20220033)+1 种基金Programs for high-level entrepreneurial and innovative talents of Jiangsu ProvinceChina Postdoctoral Science Foundation(2024T170400,2022M721551).
文摘Hydrogen peroxide(H_(2)O_(2)),as a prevalently green oxidant in the chemical industry,confronts many bottlenecks in the conventional anthraquinone-based methods,such as organic solvents dependency,energy-intensive complex operations and inherent safety risks from centralized production.The direct synthesis route from H_(2) coupled with O_(2) presents a promising alternative,but remains constrained by the safety requirement and the reaction control demand.This article systematically reviews breakthroughs in non-hydrogen catalytic systems for in situ synthesis of H_(2)O_(2).Through elucidating the mechanism of two-electron oxygen reduction pathways,renewable hydrogen substitutes with enhanced safety including CO,HCOOH,glucose and alcohols have been highlighted.Their efficient conversion of O_(2) to H_(2)O_(2) and the integration with sustainable processes such as selective oxidation are also discussed.It is expected to provide fundamental insights into the synergistic mechanism in heterogeneous catalysis and offer a new viewpoint for developing a decentralized H_(2)O_(2) synthesis system for practical applications,moving toward a greener and more economical H_(2)O_(2) production approach.
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 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.
基金supported by the Key Program of the National Natural Science Foundation of China(3163000269)National Special Fund for Modern Industrial Technology System(CARS-35)Major Science and Technology Special Fund of Zhejiang Province(2015C02022)。
文摘Background:Antibiotic growth promoters are widely used to improve weight gain.However,the abuse of antibiotics can have many negative effects on people.Developing alternatives to antibiotics is an urgent need in livestock production.We aimed to perform a meta-analysis and network meta-analysis(NMA)to investigate the effects of feed additives as potential antibiotic substitutes(ASs)on bacteriostasis,growth performance,intestinal morphology and immunity.Furthermore,the primary,secondary,and tertiary ASs were defined by comparing their results with the results of antibiotics.Results:Among 16,309 identified studies,37 were summarized to study the bacteriostasis effects of feed additives,and 89 were included in the meta-analysis and NMA(10,228 pigs).We summarized 268 associations of 57 interventions with 32 bacteria.The order of bacteriostasis effects was as follows:antimicrobial peptides(AMPs)≈antibiotics>organic acids>plant extracts>oligosaccharides.We detected associations of 11 feed additives and 11 outcomes.Compared with a basal diet,plant extract,AMPs,probiotics,microelements,organic acids,bacteriophages,lysozyme,zymin,and oligosaccharides significantly improved growth performance(P<0.05);organic acids,probiotics,microelements,lysozyme,and AMPs remarkably increased the villus height:crypt depth ratio(V/C)(P<0.05);and plant extracts,zymin,microelements,probiotics,and organic acids notably improved immunity(P<0.05).The optimal AMP,bacteriophage,lysozyme,microelements,oligosaccharides,organic acids,plants,plant extracts,probiotics,and zymin doses were 0.100%,0.150%,0.012%,0.010%,0.050%,0.750%,0.20%,0.040%,0.180%,and 0.100%,respectively.Compared with antibiotics,all investigated feed additives exhibited no significant difference in effects on growth performance,IgG,and diarrhoea index/rate(P>0.05);AMPs and microelements significantly increased V/C(P<0.05);and zymin significantly improved lymphocyte levels(P<0.05).Furthermore,linear weighting sum models were used to comprehensively estimate the overall impact of each feed additive on pig growth and health.Conclusions:Our findings suggest that AMPs and plant extracts can be used as primary ASs for weaned piglets and growing pigs,respectively.Bacteriophages,zymin,plants,probiotics,oligosaccharides,lysozyme,and microelements can be regarded as secondary ASs.Nucleotides and organic acids can be considered as tertiary ASs.Future studies should further assess the alternative effects of combinational feed additives.
文摘A study was conducted to evaluate the effects of meat and bone meal （MBM） and poultry by-product meal （PBM） as the replacement of fishmeal in the diets on the growth performance, survival and apparent digestibility coefficient （ADC） of Japanese flounder （Paralichthys olivaceus）. The experimental diets included 0%, 20%, 40%, 60% and 80% MBM or PBM replacement of total fishmeal respectively. All diets were iso-nitrogenous and isocaloric. The results showed that there are no significant differences （P 〉0.05） in growth performance among the treatments fed with 0% -60% MBM replacement of fishmeal, while the percent weight gain （WG, % ）, body length gain （BLG, % ） and ADC significantly decrease when fishmeal is replaced by 80% MBM. The result showed also that there are no significant differences （P 〉0.05） in growth performance and ADC among all treatments fed with the diets with 0% -80% replacements of fishmeal with PBM.
