Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,slu...Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,sluggish reaction dynamics,high energy consumption,and long reaction time.To overcome these chal-lenges,we first employed a high-temperature shock(HTS)strategy for fast synthesis of the NCM,and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time.In the HTS process,ultrafast average reaction rate of phase transition from Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_(2) to Li-containing oxides is 66.7(%s^(-1)),that is,taking only 1.5 s.An ultrahigh heating rate leads to fast reaction kinetics,which induces the rapid phase transition of NCM cathodes.The HTS-synthesized nickel-rich layered oxides perform good cycling performances(94%for NCM523,94%for NCM622,and 80%for NCM811 after 200 cycles at 4.3 V).These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.展开更多
Currently,lithium-sulfur(Li-S)batteries still suffer from fast capacity decay,poor coulombic efficiency(CE)and short cycling lifespan,which result from the severe shuttle effect issue caused by high solubility and rap...Currently,lithium-sulfur(Li-S)batteries still suffer from fast capacity decay,poor coulombic efficiency(CE)and short cycling lifespan,which result from the severe shuttle effect issue caused by high solubility and rapid diffusion of lithium polysulfides(Li PSs)in organic electrolytes.Here,yolk-shell zinc oxide(YSZn O)spheres are synthesized and for the first time,applied as a host for Li-S batteries to tackle this challenge.The polar Zn O exhibits high chemical anchoring ability toward Li PSs while the unique yolk-shell structure not only provides an additional physical barrier to Li PSs but also enables much more uniform sulfur distribution,thus significantly suppressing Li PSs shuttling effect meanwhile promoting sulfur conversion reactions.As a result,the YS-Zn O enables the Li-S battery to display an initial specific capacity of1355 m Ah g^(-1) and an outstanding capacity retention capability(~89.44%retention rate)even after 500 cycles with the average CE of~99.46%at the current of 0.5 C.By contrast,the capacity of conventional-Zn O-nanoparticles based battery severely decays to 472 m Ah g^(-1) after cycling for 500 times.More impressively,the S/YS-Zn O based Li-S battery can maintain a low decay rate of 0.040%every cycle and high average CE of 98.82%over 1000 cycles at 3 C.展开更多
Objectives:This study aimed to develop a self-management behavior questionnaire for Chinese enter-ostomy patients and examine its reliability and validity.Methods:Guided by the theory of self-management,an initial que...Objectives:This study aimed to develop a self-management behavior questionnaire for Chinese enter-ostomy patients and examine its reliability and validity.Methods:Guided by the theory of self-management,an initial questionnaire was generated through literature review,group meetings,and two rounds of an expert consultation.Finally,the reliability and validity of the questionnaire were validated through a questionnaire survey of 200 enterostomy patients were selected from the Affiliated Hospital of Medical University from June 2016 to March 2017.Results:The content validity index was 0.80e1.00.The exploratory factor analysis yielded a five-factor(dietary behavior,psychosocial behavior,symptom management behavior,medical compliance behavior,information management behavior),consisting of 40 items.The cumulative variance contri-bution rate was 65.42%.The Cronbach’s a coefficient for the total questionnaire was 0.972,and for the five factors ranged from 0.797 to 0.939,indicating a good internal consistency.The test-retest reliability was 0.867(P<0.01).The self-management behavior questionnaire score was negatively related to the Ostomy Skin Tool score(r=-0.800,P<0.01).Conclusions:The self-management behavior questionnaire developed in this study showed good reli-ability and validity and can be used to assess the self-management behavior of Chinese enterostomy patients.展开更多
Spinel LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)has attracted intensive interest for lithium-ion battery due to its high voltage and high energy density.However,severe capacity fade attributed to unstable surface structure ha...Spinel LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)has attracted intensive interest for lithium-ion battery due to its high voltage and high energy density.However,severe capacity fade attributed to unstable surface structure has hampered its commercialization.Oxygen vacancies(OVs)tend to occur in the surface of the material and lead to surface structure reconstruction,which deteriorates the battery performance during electrochemical cycling.Here,we utilize high-temperature-shock(HTS)method to synthesize LNMO materials with fewer surface OVs.Rapid calcination drives lower surface OVs concentration,reducing the content of Mn^(3+)and surface reconstruction layers,which is beneficial to obtain a stable crystal structure.The LNMO material synthesized by HTS method delivers an initial capacity of 127 mAh·g^(-1) at 0.1 C and capacity retention of 81.6%after 300 cycles at 1 C,and exhibits excellent performance at low temperature.展开更多
A phosphine-catalyzed [4+3] annulation between dinucleophilic indole derivatives and Morita−Baylis−Hillman (MBH) carbonates was discovered by using the N1 and N4′/C4′ nucleophilicities of the indole precursors,in wh...A phosphine-catalyzed [4+3] annulation between dinucleophilic indole derivatives and Morita−Baylis−Hillman (MBH) carbonates was discovered by using the N1 and N4′/C4′ nucleophilicities of the indole precursors,in which indoles act as four atom synthons. This protocol provides an efficient and facile access to indole-1,2-fused 1,4-diazepinones and azepines in good to high yields in one step,which illustrates potential synthetic utilities in drug discovery.展开更多
Resistance to sorafenib,an effective first-line treatment for advanced hepatocellular carcinoma(HCC),greatly compromised the prognosis of patients.The extracellular matrix is one of the most abundant components of the...Resistance to sorafenib,an effective first-line treatment for advanced hepatocellular carcinoma(HCC),greatly compromised the prognosis of patients.The extracellular matrix is one of the most abundant components of the tumor microenvironment.Beyond acting as a physical barrier,it remains unclear whether cell interactions and signal transduction mediated by the extracellular matrix contribute to sorafenib resistance.With the analysis of primary HCC organoid RNA-seq data combined with in vivo and in vitro experiments validation,we discovered that fibronectin extra domain A(FN-EDA)derived from cancer-associated fibroblasts played a critical role in sorafenib resistance.Mechanistically,FN-EDA stimulates the up-regulation of the key one-carbon metabolism enzyme SHMT1 in HCC cells via the TLR4/NF-κB signaling pathway,thereby countering the oxidative stress induced by sorafenib.Moreover,we reinforced the clinical significance of our discoveries by conducting in vivo assays with an immunodeficiency subcutaneous xenograft tumor model,which was established using primary cancer-associated fibroblasts derived from clinical HCC tissues,and through the analysis of HCC samples obtained from The Cancer Genome Atlas(TCGA)database.Our findings suggest that targeting the FN-EDA/SHMT1 pathway could be a potential strategy to improve sorafenib responsiveness in HCC patients.展开更多
In this work, a density functional theory （DFT） based first-principles study is carried out to investigate tile potential of phosphorene-like SiS and SiSe monolayers as anode materials for sodium-ion （Na-ion） bat-...In this work, a density functional theory （DFT） based first-principles study is carried out to investigate tile potential of phosphorene-like SiS and SiSe monolayers as anode materials for sodium-ion （Na-ion） bat- teries. Results show that both SiS and SiSe have large adsorption energies towards single Na atom of 0.94 and -0.43 eV, owing to the charge transfers from Na to SiS or SiSe. In addition, it is found that the highest Na concentration for both SiS and SiSe is x = 1 with the chemical formulas of NaSiS and NaSiSe, corresponding to the high theoretical specific capacities for Na storages of 445.6 and 250.4 mAh g 1, respectively. Moreover, Na diffusions are very fast and show strong directional behaviors on SiS and SiSe monolayers, with the energy barriers of only 0.135 and 0.158 eV, lower than those of con- ventional anode materials for Na-ion batteries such as Na2Ti3O7 （0.19 eV） and Na3Sb （0.21 eV）. Finally, although SiS and SiSe show semiconducting behaviors, they transform to metallic states after adsorbing Na atoms, indicating enhanced electrical conductivity during battery cycling. Given these advantages, it is expected that both SiS and SiSe monolayers are promising anode materials for Na-ion batteries, and in principle, other Na-based batteries as well.展开更多
We propose a novel concept of energy storage that incorporates electrically rechargeable liquid fuels made of electroactive species, known as e-fuels, as the storage medium. This e-fuel energy storage system comprises...We propose a novel concept of energy storage that incorporates electrically rechargeable liquid fuels made of electroactive species, known as e-fuels, as the storage medium. This e-fuel energy storage system comprises an e-fuel charger and an e-fuel cell. The e-fuel charger electrically charges e-fuels, while the efuel cell subsequently generates electricity using charged e-fuels whenever and wherever on demand.The e-fuel energy storage system possesses all the advantages of conventional hydrogen storage systems,but unlike hydrogen, liquid e-fuels are as easy and safe to store and transport as gasoline. The potential efuel candidates have been identified to include inorganic electroactive materials, organic electroactive materials, and suspension of solid electroactive materials. In this work, we demonstrate an example efuel energy storage system for large-scale energy storage using inorganic e-fuels composed of V^(2+)/V^(3+) and VO_2^+/VO_2^+ redox couples, and compare the performance of the e-fuel energy storage system with that of existing technologies. Results show that our e-fuel charger achieves a charge efficiency of as high as～94%, while the e-fuel cell is capable of delivering a peak power density of 3.4 W cm^(-2), which is 1.7 times higher than that of hydrogen fuel cells. More excitingly, the e-fuel energy storage system exhibits a round-trip efficiency of 80.0% and an electrolyte utilization of 83.0% at an ultra-high discharge current density of 1,000 mA cm^(-2), which are 19.9% and 67.3% higher than those of conventional vanadium redox flow batteries. This unprecedented performance allows a 27.0% reduction in the capital cost of the e-fuel energy storage system compared with that of vanadium redox flow batteries.展开更多
Fabricating electrodes with large specific surface area(SSA)and high permeability has been the longstanding target in redox flow batteries(RFBs).In this work,we propose a novel ZIF-8-assisted etching approach to form ...Fabricating electrodes with large specific surface area(SSA)and high permeability has been the longstanding target in redox flow batteries(RFBs).In this work,we propose a novel ZIF-8-assisted etching approach to form holey fibers in the electrospinning process of aligned electrode structures.The etching approach allows the formation of holey fibers with small pores of~50 nm,offering large active surface areas for redox reactions,while the aligned macrostructure with the holey fibers of 3–5 lm in diameter ensures a high permeability along the fiber direction.The application of the prepared electrodes to a vanadium redox flow battery(VRFB)enables an energy efficiency(EE)of 87.2%at the current density of 200 m A cm^(-2),which is 13.3%higher than that with conventional electrospun carbon electrodes.Even at high current densities of 300 and 400 m A cm^(-2),the battery still maintains energy efficiencies of 83.3%and 79.3%.More excitingly,the prepared electrode yields a high limiting current density of4500 m A cm^(-2) and a peak power density of 1.6 W cm^(-2).It is anticipated that the present electrospinning method combining the ZIF-8-assisted etching approach with a way to form ordered fiber structures will allow even more high-performance electrodes for RFBs in the future.展开更多
基金the financial support from the National Natural Science Foundation of China(Grant Nos.92372107 and 52171219).
文摘Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,sluggish reaction dynamics,high energy consumption,and long reaction time.To overcome these chal-lenges,we first employed a high-temperature shock(HTS)strategy for fast synthesis of the NCM,and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time.In the HTS process,ultrafast average reaction rate of phase transition from Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_(2) to Li-containing oxides is 66.7(%s^(-1)),that is,taking only 1.5 s.An ultrahigh heating rate leads to fast reaction kinetics,which induces the rapid phase transition of NCM cathodes.The HTS-synthesized nickel-rich layered oxides perform good cycling performances(94%for NCM523,94%for NCM622,and 80%for NCM811 after 200 cycles at 4.3 V).These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.
基金fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.T23-601/17-R)。
文摘Currently,lithium-sulfur(Li-S)batteries still suffer from fast capacity decay,poor coulombic efficiency(CE)and short cycling lifespan,which result from the severe shuttle effect issue caused by high solubility and rapid diffusion of lithium polysulfides(Li PSs)in organic electrolytes.Here,yolk-shell zinc oxide(YSZn O)spheres are synthesized and for the first time,applied as a host for Li-S batteries to tackle this challenge.The polar Zn O exhibits high chemical anchoring ability toward Li PSs while the unique yolk-shell structure not only provides an additional physical barrier to Li PSs but also enables much more uniform sulfur distribution,thus significantly suppressing Li PSs shuttling effect meanwhile promoting sulfur conversion reactions.As a result,the YS-Zn O enables the Li-S battery to display an initial specific capacity of1355 m Ah g^(-1) and an outstanding capacity retention capability(~89.44%retention rate)even after 500 cycles with the average CE of~99.46%at the current of 0.5 C.By contrast,the capacity of conventional-Zn O-nanoparticles based battery severely decays to 472 m Ah g^(-1) after cycling for 500 times.More impressively,the S/YS-Zn O based Li-S battery can maintain a low decay rate of 0.040%every cycle and high average CE of 98.82%over 1000 cycles at 3 C.
文摘Objectives:This study aimed to develop a self-management behavior questionnaire for Chinese enter-ostomy patients and examine its reliability and validity.Methods:Guided by the theory of self-management,an initial questionnaire was generated through literature review,group meetings,and two rounds of an expert consultation.Finally,the reliability and validity of the questionnaire were validated through a questionnaire survey of 200 enterostomy patients were selected from the Affiliated Hospital of Medical University from June 2016 to March 2017.Results:The content validity index was 0.80e1.00.The exploratory factor analysis yielded a five-factor(dietary behavior,psychosocial behavior,symptom management behavior,medical compliance behavior,information management behavior),consisting of 40 items.The cumulative variance contri-bution rate was 65.42%.The Cronbach’s a coefficient for the total questionnaire was 0.972,and for the five factors ranged from 0.797 to 0.939,indicating a good internal consistency.The test-retest reliability was 0.867(P<0.01).The self-management behavior questionnaire score was negatively related to the Ostomy Skin Tool score(r=-0.800,P<0.01).Conclusions:The self-management behavior questionnaire developed in this study showed good reli-ability and validity and can be used to assess the self-management behavior of Chinese enterostomy patients.
基金support from the National Natural Science Foundation of China(No.52171219).
文摘Spinel LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)has attracted intensive interest for lithium-ion battery due to its high voltage and high energy density.However,severe capacity fade attributed to unstable surface structure has hampered its commercialization.Oxygen vacancies(OVs)tend to occur in the surface of the material and lead to surface structure reconstruction,which deteriorates the battery performance during electrochemical cycling.Here,we utilize high-temperature-shock(HTS)method to synthesize LNMO materials with fewer surface OVs.Rapid calcination drives lower surface OVs concentration,reducing the content of Mn^(3+)and surface reconstruction layers,which is beneficial to obtain a stable crystal structure.The LNMO material synthesized by HTS method delivers an initial capacity of 127 mAh·g^(-1) at 0.1 C and capacity retention of 81.6%after 300 cycles at 1 C,and exhibits excellent performance at low temperature.
基金the financial support from the funding for school-level research projects of Yancheng Institute of Technology(No.XJR2022019,XJ201719).
文摘A phosphine-catalyzed [4+3] annulation between dinucleophilic indole derivatives and Morita−Baylis−Hillman (MBH) carbonates was discovered by using the N1 and N4′/C4′ nucleophilicities of the indole precursors,in which indoles act as four atom synthons. This protocol provides an efficient and facile access to indole-1,2-fused 1,4-diazepinones and azepines in good to high yields in one step,which illustrates potential synthetic utilities in drug discovery.
基金supported in part by the National Natural Science Foundation of China (No.81672856,82203669,81803028)the General Program of Chongqing Natural Science Foundation (China) (No.cstc2021jcyj-msxmX0687).
文摘Resistance to sorafenib,an effective first-line treatment for advanced hepatocellular carcinoma(HCC),greatly compromised the prognosis of patients.The extracellular matrix is one of the most abundant components of the tumor microenvironment.Beyond acting as a physical barrier,it remains unclear whether cell interactions and signal transduction mediated by the extracellular matrix contribute to sorafenib resistance.With the analysis of primary HCC organoid RNA-seq data combined with in vivo and in vitro experiments validation,we discovered that fibronectin extra domain A(FN-EDA)derived from cancer-associated fibroblasts played a critical role in sorafenib resistance.Mechanistically,FN-EDA stimulates the up-regulation of the key one-carbon metabolism enzyme SHMT1 in HCC cells via the TLR4/NF-κB signaling pathway,thereby countering the oxidative stress induced by sorafenib.Moreover,we reinforced the clinical significance of our discoveries by conducting in vivo assays with an immunodeficiency subcutaneous xenograft tumor model,which was established using primary cancer-associated fibroblasts derived from clinical HCC tissues,and through the analysis of HCC samples obtained from The Cancer Genome Atlas(TCGA)database.Our findings suggest that targeting the FN-EDA/SHMT1 pathway could be a potential strategy to improve sorafenib responsiveness in HCC patients.
基金supported by the grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (16213414)
文摘In this work, a density functional theory （DFT） based first-principles study is carried out to investigate tile potential of phosphorene-like SiS and SiSe monolayers as anode materials for sodium-ion （Na-ion） bat- teries. Results show that both SiS and SiSe have large adsorption energies towards single Na atom of 0.94 and -0.43 eV, owing to the charge transfers from Na to SiS or SiSe. In addition, it is found that the highest Na concentration for both SiS and SiSe is x = 1 with the chemical formulas of NaSiS and NaSiSe, corresponding to the high theoretical specific capacities for Na storages of 445.6 and 250.4 mAh g 1, respectively. Moreover, Na diffusions are very fast and show strong directional behaviors on SiS and SiSe monolayers, with the energy barriers of only 0.135 and 0.158 eV, lower than those of con- ventional anode materials for Na-ion batteries such as Na2Ti3O7 （0.19 eV） and Na3Sb （0.21 eV）. Finally, although SiS and SiSe show semiconducting behaviors, they transform to metallic states after adsorbing Na atoms, indicating enhanced electrical conductivity during battery cycling. Given these advantages, it is expected that both SiS and SiSe monolayers are promising anode materials for Na-ion batteries, and in principle, other Na-based batteries as well.
基金fully supported by the Grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (T23-601/17-R)
文摘We propose a novel concept of energy storage that incorporates electrically rechargeable liquid fuels made of electroactive species, known as e-fuels, as the storage medium. This e-fuel energy storage system comprises an e-fuel charger and an e-fuel cell. The e-fuel charger electrically charges e-fuels, while the efuel cell subsequently generates electricity using charged e-fuels whenever and wherever on demand.The e-fuel energy storage system possesses all the advantages of conventional hydrogen storage systems,but unlike hydrogen, liquid e-fuels are as easy and safe to store and transport as gasoline. The potential efuel candidates have been identified to include inorganic electroactive materials, organic electroactive materials, and suspension of solid electroactive materials. In this work, we demonstrate an example efuel energy storage system for large-scale energy storage using inorganic e-fuels composed of V^(2+)/V^(3+) and VO_2^+/VO_2^+ redox couples, and compare the performance of the e-fuel energy storage system with that of existing technologies. Results show that our e-fuel charger achieves a charge efficiency of as high as～94%, while the e-fuel cell is capable of delivering a peak power density of 3.4 W cm^(-2), which is 1.7 times higher than that of hydrogen fuel cells. More excitingly, the e-fuel energy storage system exhibits a round-trip efficiency of 80.0% and an electrolyte utilization of 83.0% at an ultra-high discharge current density of 1,000 mA cm^(-2), which are 19.9% and 67.3% higher than those of conventional vanadium redox flow batteries. This unprecedented performance allows a 27.0% reduction in the capital cost of the e-fuel energy storage system compared with that of vanadium redox flow batteries.
基金financially supported by the grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(T23-601/17-R)the National Natural Science Foundation of China(21703263)HKUST Fund of Nanhai(FSNH-18FYTRI01)。
文摘Fabricating electrodes with large specific surface area(SSA)and high permeability has been the longstanding target in redox flow batteries(RFBs).In this work,we propose a novel ZIF-8-assisted etching approach to form holey fibers in the electrospinning process of aligned electrode structures.The etching approach allows the formation of holey fibers with small pores of~50 nm,offering large active surface areas for redox reactions,while the aligned macrostructure with the holey fibers of 3–5 lm in diameter ensures a high permeability along the fiber direction.The application of the prepared electrodes to a vanadium redox flow battery(VRFB)enables an energy efficiency(EE)of 87.2%at the current density of 200 m A cm^(-2),which is 13.3%higher than that with conventional electrospun carbon electrodes.Even at high current densities of 300 and 400 m A cm^(-2),the battery still maintains energy efficiencies of 83.3%and 79.3%.More excitingly,the prepared electrode yields a high limiting current density of4500 m A cm^(-2) and a peak power density of 1.6 W cm^(-2).It is anticipated that the present electrospinning method combining the ZIF-8-assisted etching approach with a way to form ordered fiber structures will allow even more high-performance electrodes for RFBs in the future.
