The sustenance of humanity is contingent upon the production of food.The foundation of this production is agriculture,which in turn is dependent upon the cultivation of the land.As a fundamental element of agricultura...The sustenance of humanity is contingent upon the production of food.The foundation of this production is agriculture,which in turn is dependent upon the cultivation of the land.As a fundamental element of agricultural advancement,the rational development and utilization of land play a pivotal role in the process of rural revitalization.Agricultural land productivity serves as a principal indicator of the efficacy of land utilization and the extent of agricultural advancement.Nevertheless,there is a paucity of research examining the productivity of agricultural land,particularly a lack of specialized research on large agricultural provinces.In light of the aforementioned considerations,this paper presents a comprehensive examination of agricultural land productivity and its regional variations in Heilongjiang Province in 2022,with the aid of pertinent statistical data.The findings of the analysis indicate that among the prefecture-level cities,Daqing and Suihua exhibit the highest levels of agricultural land productivity.Additionally,Zhaodong City,Zhaozhou,Qinggang,Wangkui,and Lanxi counties exhibit high levels of agricultural land productivity within their respective prefecture-level cities.There are notable disparities in agricultural land productivity across various regions,including Yichun,Heihe,Harbin,Daqing,Hegang,and Suihua.In contrast,other regions demonstrate a more balanced spatial distribution.In order to facilitate the prosperous development of the agricultural industry in Heilongjiang Province,it is essential to optimize the spatial planning of the land,to investigate the potential for agricultural development in each region,to establish effective collaboration between resources and industries,and to create a development synergy that will collectively advance rural revitalization.展开更多
With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-...With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-being of farmers and the vigorous development of the rural economy.The reform of this system is not only a key driving force for rural economic development,but also an important cornerstone for realizing the rural revitalization strategy.Through in-depth analysis of the connotation of rural revitalization and rural land system reform,this study discusses in detail the internal dynamic mechanism of rural land system reform driving rural revitalization,and comprehensively analyzes the current implementation of rural land system reform.On this basis,this study puts forward the strategic concept of promoting the rural land system reform in the context of rural revitalization.Studies have shown that the rural land system reform has mainly played a positive role in the following four aspects in promoting rural revitalization:providing a solid material foundation for rural revitalization,optimizing the allocation of rural resources,promoting the transformation and upgrading of rural industrial structure,and promoting rural social harmony and stability.In the context of the current rural revitalization,the rural land system reform is undoubtedly one of the core issues of China s rural development.In order to further improve this system,we need to continue to optimize and innovate the rural land transfer system,the homestead reform system,and the rural collective construction land market entry system.展开更多
[Objectives]To explore the relationship between rural industry revitalization and land resource utilization.[Methods]Starting from the connotation of rural industry revitalization and land resource utilization,this st...[Objectives]To explore the relationship between rural industry revitalization and land resource utilization.[Methods]Starting from the connotation of rural industry revitalization and land resource utilization,this study explores the relationship between rural industry revitalization and land resource utilization,Taking Ganning Town with typical mountain industry as the research area,this paper analyzed the relationship between rural industry revitalization and land resource utilization through a combination of field research and literature analysis,found out the existing problems and came up with pertinent recommendations.[Results](i)Rural industry revitalization is both mutually reinforcing and mutually restrictive.(ii)In this study,the land use types of Ganning Town were divided into nine categories,including farmland,garden land,forest land and grassland,and their industrial functions and development models were identified,and the corresponding framework of land resource utilization and rural industry revitalization in Ganning Town was constructed.(iii)In view of the problems existing in Ganning Town,this paper proposed to change the ideological concept and enhance understanding,improve the utilization rate of idle land and promote rural industry revitalization,and accelerate land consolidation and restoration,and promote sustainable development.[Conclusions]It is necessary to correctly understand the two-way role and dynamic change relationship between rural industry revitalization and land resource utilization,solve the problem from the perspective of development,adopt development strategies according to local conditions,and take the road of sustainable development.展开更多
Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune th...Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.展开更多
Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration,poor efficacy and side effects.Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic s...Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration,poor efficacy and side effects.Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution(FC-TNL)has the ability to treat glaucoma by lowering the intraocular pressure(IOP)with great efficacy and improving patient compliance.However,the commercialized netarsudil dimesylate precipitated when the p H of the solution was above 5.4,or when maleic acid,the salt of commercial timolol maleate,was mixed with netarsudil dimesylate.Consequently,the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in p H 4.8–5.2 solution by synthesizing timolol mesylate.Next,the morphology of timolol mesylate was observed by scanning electron microscopy,differential scanning calorimetry,thermogravimetric analysis,and powder X-ray diffraction.The prepared FC-TNL showed good stability during refrigeration storage.Additionally,FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study.Importantly,oncedaily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells.The FC-TNL was stable,safe and effective,being a promising glaucoma therapeutic.展开更多
Global warming-induced changes in tree-growth resilience to climate variations have been widely reported for mid-and high-latitude regions around the world. Most studies have focused on the spatial variability of tree...Global warming-induced changes in tree-growth resilience to climate variations have been widely reported for mid-and high-latitude regions around the world. Most studies have focused on the spatial variability of trees in radial growth-climate relationships on Changbai Mountain in Northeast China, but little is known about temporal changes in tree growth in response to climate. We explored the stability of effect of climate variables on radial growth of Yezo spruce [Picea jezoensis Carr. var. komarovii(V.Vassil.) Cheng et L.K.Fu] at 1200, 1400, and 1600 m above sea level, representing low, middle, and upper ranges of the spruce-fir mixed forest on Changbai Mountain. The results showed that the relation between tree growth and climate did not vary with altitude, but the stability of the tree-growth-climate relationship did vary with altitude as the climate changed. Radial growth of Yezo spruce at allthree elevations was influenced primarily by maximum temperature during May(Tmax5) and mean minimum temperature from January to March(Tmin1-3). More specifically, the relationship strengthened significantly at lower elevations, but weakened significantly at higher elevation, and fluctuated at mid elevations since 1980.Increase in Tmin1-3 and decrease in Tmax5 were the main reasons for the decrease in the radial growth at three altitudes. The findings of this study clarified that the decrease in radial growth on Changbai Mountain is not a “divergence problem” of an unexpected decrease in tree growth in response to an increase in mean temperature and provides a reference for using tree-ring data to reconstruct climate patterns and/or predict the growth of trees under various climate change scenarios.展开更多
The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from d...The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic conditions.Herein,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic ratio.This alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to poisoning.Combining in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of ethanol.This work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.展开更多
Hypoxia, a salient feature of most solid tumors, confers invasiveness and resistance to the tumor cells. Oxygen-consumption photodynamic therapy(PDT) suffers from the undesirable impediment of local hypoxia in tumors....Hypoxia, a salient feature of most solid tumors, confers invasiveness and resistance to the tumor cells. Oxygen-consumption photodynamic therapy(PDT) suffers from the undesirable impediment of local hypoxia in tumors. Moreover, PDT could further worsen hypoxia. Therefore, developing effective strategies for manipulating hypoxia and improving the effectiveness of PDT has been a focus on antitumor treatment. In this review, the mechanism and relationship of tumor hypoxia and PDT are discussed.Moreover, we highlight recent trends in the field of nanomedicines to modulate hypoxia for enhancing PDT, such as oxygen supply systems, down-regulation of oxygen consumption and hypoxia utilization.Finally, the opportunities and challenges are put forward to facilitate the development and clinical transformation of PDT.展开更多
Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) ...Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) electroreduction.Herein,a synergistical tuning on the electronic structure of the Cd Se nanorods is proposed for boosting electrochemical reduction of CO_(2) .The synergy of Ag doping coupled with Se vacancies tuned the electronic structure of the CdSe nanorods,which shows the metalloid characterization and thereby the accelerated electron transfer of CO_(2) electroreduction.Operando synchrotron radiation Fourier transform infrared spectroscopy and theoretical simulation revealed that the Ag doping and Se vacancies accelerated the CO_(2) activation process and lowered the energy barrier for the conversion from CO_(2) to;COOH;as a result,the performance of CO_(2) electroreduction was enhanced.The as-obtained metalloid Ag-doped CdSe nanorods exhibited a 2.7-fold increment in current density and 1.9-fold Faradaic efficiency of CO compared with the pristine CdSe nanorod.展开更多
As a high specific speed pump, the contra-rotating axial flow pump distinguishes itself in a rear rotor rotating in the opposite direction of the front rotor, which remarkably contributes to the energy conversion, the...As a high specific speed pump, the contra-rotating axial flow pump distinguishes itself in a rear rotor rotating in the opposite direction of the front rotor, which remarkably contributes to the energy conversion, the reduction of the pump size, better hydraulic and cavitation performances. However, with two rotors rotating reversely, the significant interaction between blade rows was observed in our prototype contra-rotating rotors, which highly affected the pump performance compared with the conventional axial flow pumps. Consequently, a new type of rear rotor was designed by the rotational speed optimization methodology with some additional considerations, aiming at better cavitation performance, the reduction of blade rows interaction and the secondary flow suppression. The new rear rotor showed a satisfactory performance at the design flow rate but an unfavorable positive slope of the head - flow rate curve in the partial flow rate range less than 40% of the design flow rate, which should be avoided for the reliability of pump-pipe systems. In the present research, to understand the internal flow field of new rear rotor and its relation to the performances at the partial flow rates, the velocity distributions at the inlets and outlets of the rotors are firstly investigated. Then, the boundary layer flows on rotor surfaces, which clearly reflect the secondary flow inside the rotors, are analyzed through the limiting streamline observations using the multi-color oil-film method. Finally, the unsteady numerical simulations are carded out to understand the complicated internal flow structures in the rotors.展开更多
Designing active sites and engineering electronic properties of heterogeneous catalysts are both promising strategies that can be employed to enhance the catalytic activity for CO2 hydrogenation. Herein, we report RhC...Designing active sites and engineering electronic properties of heterogeneous catalysts are both promising strategies that can be employed to enhance the catalytic activity for CO2 hydrogenation. Herein, we report RhCo porous nanospheres with a high density of accessible grain boundaries as active sites for improved catalytic performance in the hydrogenation of CO2 to methanol. The porous nanosphere morphological feature allows for a high population of grain boundaries to be accessible to the reactants, thereby providing sufficient active sites for the catalytic reaction. Moreover, in-situ X-ray photoelectron spectroscope (XPS) results revealed the creation of negatively charged Rh surface atoms that promoted the activation of CO2 to generate CO2^6- and methoxy intermediates. The obtained RhCo porous nanospheres exhibited remarkable low-temperature catalytic activity with a turnover frequency (TOFRh) of 612 h^-1, which was 6.1 and 2.5 times higher than that of Rh/C and RhCo nanoparticles, respectively. This work not only develops an efficient catalyst for CO2 hydrogenation, but also demonstrates a potential approach for the modulation of active sites and electronic properties.展开更多
Background and Aims:Recent genome-wide association studies have shown that low-density lipoprotein receptor(LDLR)rs1433099 polymorphism is associated with cardiovascular disease(CVD)risk in many countries.However,the ...Background and Aims:Recent genome-wide association studies have shown that low-density lipoprotein receptor(LDLR)rs1433099 polymorphism is associated with cardiovascular disease(CVD)risk in many countries.However,the association of LDLR rs1433099 with CVD in China has not been reported yet.There are no studies on LDLR rs1433099 and non-alcoholic fatty liver disease(NAFLD)as well.The purpose of this study was to investigate whether LDLR rs1433099 is related to CVD or NAFLD in the Chinese population.Methods:LDLR rs1433099 polymorphism was genotyped in 507 individuals,including 140 healthy controls,79 NAFLD patients,185 CVD patients,and 103 patients with NAFLD combined with CVD.The expression of LDLR was tested by the sequence detection system,and clinical parameters were assessed by biochemical tests and physical examination.Results:The genotype distribution of LDLR rs1433099 was not statistically different among the NAFLD group,the CVD group,the combined group,and the healthy control group(p>0.05).There was no significant correlation of LDLR rs1433099 genotypic distribution or allele frequency and the risk of NAFLD,CVD or NAFLD combined with CVD(p>0.05).In the CVD group,T allele carriers had higher alkaline phosphatase and gamma-glutamyl transpeptidase than non-carriers(p<0.05).Conclusions:Our study demonstrated that the LDLR rs1433099 polymorphism is not a risk factor of NAFLD.The LDLR rs1433099 polymorphism may increase the risk of CVD through a mechanism involving alkaline phosphatase and gamma-glutamyl transpeptidase.展开更多
文摘The sustenance of humanity is contingent upon the production of food.The foundation of this production is agriculture,which in turn is dependent upon the cultivation of the land.As a fundamental element of agricultural advancement,the rational development and utilization of land play a pivotal role in the process of rural revitalization.Agricultural land productivity serves as a principal indicator of the efficacy of land utilization and the extent of agricultural advancement.Nevertheless,there is a paucity of research examining the productivity of agricultural land,particularly a lack of specialized research on large agricultural provinces.In light of the aforementioned considerations,this paper presents a comprehensive examination of agricultural land productivity and its regional variations in Heilongjiang Province in 2022,with the aid of pertinent statistical data.The findings of the analysis indicate that among the prefecture-level cities,Daqing and Suihua exhibit the highest levels of agricultural land productivity.Additionally,Zhaodong City,Zhaozhou,Qinggang,Wangkui,and Lanxi counties exhibit high levels of agricultural land productivity within their respective prefecture-level cities.There are notable disparities in agricultural land productivity across various regions,including Yichun,Heihe,Harbin,Daqing,Hegang,and Suihua.In contrast,other regions demonstrate a more balanced spatial distribution.In order to facilitate the prosperous development of the agricultural industry in Heilongjiang Province,it is essential to optimize the spatial planning of the land,to investigate the potential for agricultural development in each region,to establish effective collaboration between resources and industries,and to create a development synergy that will collectively advance rural revitalization.
文摘With the deepening of reform and opening up,the rural land system has experienced the evolution from contracting to transfer to the current rural revitalization strategy,and has always been closely linked to the well-being of farmers and the vigorous development of the rural economy.The reform of this system is not only a key driving force for rural economic development,but also an important cornerstone for realizing the rural revitalization strategy.Through in-depth analysis of the connotation of rural revitalization and rural land system reform,this study discusses in detail the internal dynamic mechanism of rural land system reform driving rural revitalization,and comprehensively analyzes the current implementation of rural land system reform.On this basis,this study puts forward the strategic concept of promoting the rural land system reform in the context of rural revitalization.Studies have shown that the rural land system reform has mainly played a positive role in the following four aspects in promoting rural revitalization:providing a solid material foundation for rural revitalization,optimizing the allocation of rural resources,promoting the transformation and upgrading of rural industrial structure,and promoting rural social harmony and stability.In the context of the current rural revitalization,the rural land system reform is undoubtedly one of the core issues of China s rural development.In order to further improve this system,we need to continue to optimize and innovate the rural land transfer system,the homestead reform system,and the rural collective construction land market entry system.
基金Supported by National Natural Science Foundation of China(41261018).
文摘[Objectives]To explore the relationship between rural industry revitalization and land resource utilization.[Methods]Starting from the connotation of rural industry revitalization and land resource utilization,this study explores the relationship between rural industry revitalization and land resource utilization,Taking Ganning Town with typical mountain industry as the research area,this paper analyzed the relationship between rural industry revitalization and land resource utilization through a combination of field research and literature analysis,found out the existing problems and came up with pertinent recommendations.[Results](i)Rural industry revitalization is both mutually reinforcing and mutually restrictive.(ii)In this study,the land use types of Ganning Town were divided into nine categories,including farmland,garden land,forest land and grassland,and their industrial functions and development models were identified,and the corresponding framework of land resource utilization and rural industry revitalization in Ganning Town was constructed.(iii)In view of the problems existing in Ganning Town,this paper proposed to change the ideological concept and enhance understanding,improve the utilization rate of idle land and promote rural industry revitalization,and accelerate land consolidation and restoration,and promote sustainable development.[Conclusions]It is necessary to correctly understand the two-way role and dynamic change relationship between rural industry revitalization and land resource utilization,solve the problem from the perspective of development,adopt development strategies according to local conditions,and take the road of sustainable development.
基金This work was supported by National Natural Science Foundation of China(Grants No.12025505)China Ministry of Science and Technology(2017YFA0208300)+2 种基金Youth Innovation Promotion Association CAS(CX2310007007 and CX2310000091)Open Fund Project of State Key Laboratory of Environmentally Friendly Energy Materials(20kfhg08)We would thank NSRL and SSRF for the synchrotron beam time.The calculations were performed on the supercomputing system in the Supercomputing Center of University of Science and Technology of China.
文摘Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.
基金financially supported by the Liao Ning Revitalization Talents Program(XLYC1902061)。
文摘Currently commercial fixed-concomitant three agents have multiple problems such as multiple dosing administration,poor efficacy and side effects.Once-daily fixed-combination timolol-netarsudil-latanoprost ophthalmic solution(FC-TNL)has the ability to treat glaucoma by lowering the intraocular pressure(IOP)with great efficacy and improving patient compliance.However,the commercialized netarsudil dimesylate precipitated when the p H of the solution was above 5.4,or when maleic acid,the salt of commercial timolol maleate,was mixed with netarsudil dimesylate.Consequently,the homologous salt engineering strategy was used to make netarsudil dimesylate soluble in p H 4.8–5.2 solution by synthesizing timolol mesylate.Next,the morphology of timolol mesylate was observed by scanning electron microscopy,differential scanning calorimetry,thermogravimetric analysis,and powder X-ray diffraction.The prepared FC-TNL showed good stability during refrigeration storage.Additionally,FC-TNL exerted no influence on the intraocular penetration of each active compounds in the pharmacokinetic study.Importantly,oncedaily FC-TNL exerted potent IOP-lowering effect and protective effect on retinal ganglion cells.The FC-TNL was stable,safe and effective,being a promising glaucoma therapeutic.
基金supported by the National Natural Science Foundation of China(Project No.41371124)。
文摘Global warming-induced changes in tree-growth resilience to climate variations have been widely reported for mid-and high-latitude regions around the world. Most studies have focused on the spatial variability of trees in radial growth-climate relationships on Changbai Mountain in Northeast China, but little is known about temporal changes in tree growth in response to climate. We explored the stability of effect of climate variables on radial growth of Yezo spruce [Picea jezoensis Carr. var. komarovii(V.Vassil.) Cheng et L.K.Fu] at 1200, 1400, and 1600 m above sea level, representing low, middle, and upper ranges of the spruce-fir mixed forest on Changbai Mountain. The results showed that the relation between tree growth and climate did not vary with altitude, but the stability of the tree-growth-climate relationship did vary with altitude as the climate changed. Radial growth of Yezo spruce at allthree elevations was influenced primarily by maximum temperature during May(Tmax5) and mean minimum temperature from January to March(Tmin1-3). More specifically, the relationship strengthened significantly at lower elevations, but weakened significantly at higher elevation, and fluctuated at mid elevations since 1980.Increase in Tmin1-3 and decrease in Tmax5 were the main reasons for the decrease in the radial growth at three altitudes. The findings of this study clarified that the decrease in radial growth on Changbai Mountain is not a “divergence problem” of an unexpected decrease in tree growth in response to an increase in mean temperature and provides a reference for using tree-ring data to reconstruct climate patterns and/or predict the growth of trees under various climate change scenarios.
基金supported by the National Natural Science Foundation of China(Nos.12025505,12105287,22002147,22179125,U21A20317,and 22373001)the National Key Research and Development Program of China(No.2021YFA1600800)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0450200)the Fundamental Research Funds for the Central Universities(No.KY2310000097)Xiaomi Young Talents Programsupported by the Supercomputing Center of the USTC.
文摘The inefficiency of ethanol oxidation reaction(EOR)presents a significant obstacle in harnessing renewable biofuels with high energy density into electricity.Despite efforts,most Pt-based catalysts still suffer from drawbacks such as poor activity and susceptibility to CO poisoning,particularly in acidic conditions.Herein,we employed a physical laser-assisted approach to synthetize a PtPd alloy with a 1:1 atomic ratio.This alloy demonstrates remarkable performance in acidic EOR,boasting a high mass activity of 1.86 A·mgPt^(−1)and competitive resistance to poisoning.Combining in situ synchrotron radiation infrared spectroscopy with theoretical calculations,we reveal that the synergic interaction between Pt and Pd enhances both the adsorption of OH*intermediate and the dehydrogenation ability of ethanol.This work will prove the feasibility of synthesizing bimetallic alloys by a physical laser-assisted strategy and promote the development of advanced alloy electrocatalysts.
基金financially supported by National Natural Science Foundation of China(Nos.81573371 and U1608283)Liaoning Revitalization Talents Program(No.XLYC1808017,China)+1 种基金Key projects of Technology Bureau in Shenyang(No.18400408,China)Key Projects of Liaoning Province Department of Education(No.2017LZD03,China)
文摘Hypoxia, a salient feature of most solid tumors, confers invasiveness and resistance to the tumor cells. Oxygen-consumption photodynamic therapy(PDT) suffers from the undesirable impediment of local hypoxia in tumors. Moreover, PDT could further worsen hypoxia. Therefore, developing effective strategies for manipulating hypoxia and improving the effectiveness of PDT has been a focus on antitumor treatment. In this review, the mechanism and relationship of tumor hypoxia and PDT are discussed.Moreover, we highlight recent trends in the field of nanomedicines to modulate hypoxia for enhancing PDT, such as oxygen supply systems, down-regulation of oxygen consumption and hypoxia utilization.Finally, the opportunities and challenges are put forward to facilitate the development and clinical transformation of PDT.
基金supported by the National Natural Science Foundation of China(12025505 and 21873050)China Ministry of Science and Technology(2017YFA0208300)+1 种基金the Open Fund Project of State Key Laboratory of Environmentally Friendly Energy Materials(20KFHG08)the Youth Innovation Promotion Association CAS(CX2310007007 and CX2310000091)。
文摘Engineering the electronic properties of catalysts to target intermediate adsorption energy as well as harvest high selectivity represents a promising strategy to design advanced electrocatalysts for efficient CO_(2) electroreduction.Herein,a synergistical tuning on the electronic structure of the Cd Se nanorods is proposed for boosting electrochemical reduction of CO_(2) .The synergy of Ag doping coupled with Se vacancies tuned the electronic structure of the CdSe nanorods,which shows the metalloid characterization and thereby the accelerated electron transfer of CO_(2) electroreduction.Operando synchrotron radiation Fourier transform infrared spectroscopy and theoretical simulation revealed that the Ag doping and Se vacancies accelerated the CO_(2) activation process and lowered the energy barrier for the conversion from CO_(2) to;COOH;as a result,the performance of CO_(2) electroreduction was enhanced.The as-obtained metalloid Ag-doped CdSe nanorods exhibited a 2.7-fold increment in current density and 1.9-fold Faradaic efficiency of CO compared with the pristine CdSe nanorod.
文摘As a high specific speed pump, the contra-rotating axial flow pump distinguishes itself in a rear rotor rotating in the opposite direction of the front rotor, which remarkably contributes to the energy conversion, the reduction of the pump size, better hydraulic and cavitation performances. However, with two rotors rotating reversely, the significant interaction between blade rows was observed in our prototype contra-rotating rotors, which highly affected the pump performance compared with the conventional axial flow pumps. Consequently, a new type of rear rotor was designed by the rotational speed optimization methodology with some additional considerations, aiming at better cavitation performance, the reduction of blade rows interaction and the secondary flow suppression. The new rear rotor showed a satisfactory performance at the design flow rate but an unfavorable positive slope of the head - flow rate curve in the partial flow rate range less than 40% of the design flow rate, which should be avoided for the reliability of pump-pipe systems. In the present research, to understand the internal flow field of new rear rotor and its relation to the performances at the partial flow rates, the velocity distributions at the inlets and outlets of the rotors are firstly investigated. Then, the boundary layer flows on rotor surfaces, which clearly reflect the secondary flow inside the rotors, are analyzed through the limiting streamline observations using the multi-color oil-film method. Finally, the unsteady numerical simulations are carded out to understand the complicated internal flow structures in the rotors.
基金This work was financially supported by the National Key Research and Development Program of China (No. 2017YFA0208300), the National Natural Science Foundation of China (Nos. 11505187, 11404314, 11422547, 21471143, and 51676178) and the Fundamental Research Funds for the Central Universities (Nos. WK2310000066, WK2310000050, WK2340000076, and KY2310000019), and Youth Innovation Promotion Association CAS (Nos. CX2310000054 and CX2310000091). We also thank the beamline 1W1B at the Beijing Synchrotron Radiation Facility and the Beamline BL14W1 at Sh~anghai Synchrotron Radiation Facility for help in characterizations.
文摘Designing active sites and engineering electronic properties of heterogeneous catalysts are both promising strategies that can be employed to enhance the catalytic activity for CO2 hydrogenation. Herein, we report RhCo porous nanospheres with a high density of accessible grain boundaries as active sites for improved catalytic performance in the hydrogenation of CO2 to methanol. The porous nanosphere morphological feature allows for a high population of grain boundaries to be accessible to the reactants, thereby providing sufficient active sites for the catalytic reaction. Moreover, in-situ X-ray photoelectron spectroscope (XPS) results revealed the creation of negatively charged Rh surface atoms that promoted the activation of CO2 to generate CO2^6- and methoxy intermediates. The obtained RhCo porous nanospheres exhibited remarkable low-temperature catalytic activity with a turnover frequency (TOFRh) of 612 h^-1, which was 6.1 and 2.5 times higher than that of Rh/C and RhCo nanoparticles, respectively. This work not only develops an efficient catalyst for CO2 hydrogenation, but also demonstrates a potential approach for the modulation of active sites and electronic properties.
基金This study was supported by grants from the National Natural Science Foundation of China(No.31770837).
文摘Background and Aims:Recent genome-wide association studies have shown that low-density lipoprotein receptor(LDLR)rs1433099 polymorphism is associated with cardiovascular disease(CVD)risk in many countries.However,the association of LDLR rs1433099 with CVD in China has not been reported yet.There are no studies on LDLR rs1433099 and non-alcoholic fatty liver disease(NAFLD)as well.The purpose of this study was to investigate whether LDLR rs1433099 is related to CVD or NAFLD in the Chinese population.Methods:LDLR rs1433099 polymorphism was genotyped in 507 individuals,including 140 healthy controls,79 NAFLD patients,185 CVD patients,and 103 patients with NAFLD combined with CVD.The expression of LDLR was tested by the sequence detection system,and clinical parameters were assessed by biochemical tests and physical examination.Results:The genotype distribution of LDLR rs1433099 was not statistically different among the NAFLD group,the CVD group,the combined group,and the healthy control group(p>0.05).There was no significant correlation of LDLR rs1433099 genotypic distribution or allele frequency and the risk of NAFLD,CVD or NAFLD combined with CVD(p>0.05).In the CVD group,T allele carriers had higher alkaline phosphatase and gamma-glutamyl transpeptidase than non-carriers(p<0.05).Conclusions:Our study demonstrated that the LDLR rs1433099 polymorphism is not a risk factor of NAFLD.The LDLR rs1433099 polymorphism may increase the risk of CVD through a mechanism involving alkaline phosphatase and gamma-glutamyl transpeptidase.