Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence....Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence.This resistance renders conventional drug therapies ineffective,presenting a substantial challenge to human health and medical care.Exploring natural products as potential sources for anti-cancer drugs could lead to the development of innovative and efficacious cancer treatments.This article aims to investigate the health implications of natural products(such as paclitaxel,podophyllotoxin,homoharringtonine,camptothecin,and vinblastine)in the discovery of anti-cancer drugs while discussing the methods and progress made in researching novel anti-cancer drugs derived from natural products.The paper discusses the diversity,intricate structures,and target affinity of natural products along with their structural modification techniques,combination therapies utilization possibilities with prodrugs or nanoparticles.Additionally,considering the escalating multidrug resistance observed in tumors nowadays;certain natural products offer new insights and approaches for discovering effective anti-tumor drugs that are crucial for addressing global public health challenges.The challenges faced by natural products during drug development including issues related to bioavailability toxicity concerns as well as limited resources are examined thoroughly.Potential opportunities current issues along with future challenges are highlighted aiming at facilitating the clinical translation of original anti-cancer drugs using natural products.展开更多
The van der Waals (vdW) interaction is very important in fields of physics, biology and chemistry, and its role in reaction dynamics is an issue of great interest. In this review, we focus on the recent progresses in ...The van der Waals (vdW) interaction is very important in fields of physics, biology and chemistry, and its role in reaction dynamics is an issue of great interest. In this review, we focus on the recent progresses in the theoretical and experimental studies on the vdW interaction in bimolecular reactions. In particular, we review those studies that have advanced our understanding of how the vdW interaction can strongly influence the dynamics in both direct activated and complex-forming reactions, and further extend the discussion to the polyatomic reactions involving more atoms and those occurring at cold and ultracold temperatures. We indicate that an accurate description of the delicate vdW structure and long-range potential remains a challenge nowadays in either ab initio calculations or the fitting of the potential energy surfaces. We also present an explanation on the concept of vdW saddle proposed by us recently which may have general importance.展开更多
Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very g...Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very good descriptions of the regions around conical intersections and of van der Waals(vdW)interactions.The calculated reaction thermal rate coefficients are in very good agreement with the latest experimental results.The rate coefficients obtained from the ground˜a^(1)A′ZMB-a PES are much larger than those from the previous RKHS PES,which can be attributed to that the vdW saddles on our PESs have very different dynamical effects from the vdW wells on the previous PESs,indicating that the RPMD approach is able to include dynamical effects of the topological structures caused by vdW interactions.The importance of the excited˜b^(1)A′′ZMB-b PES and quantum effects in the title reaction is also underscored.展开更多
Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chain...Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chains on the molecular packing and electron transport properties of a series of bay-linked dimeric perylenediimide(PDI) derivatives by atomistic molecular dynamics simulations in combination with charge transfer rate theory and kinetic Monte Carlo simulations. The results show that despite of different branching positions of the alkyl chains,π–π stacking is effectively inhibited for all the dimeric PDI derivatives. As the branching position moves away from the PDI backbone, the appearance of the alkyl atoms around the PDI backbone will first decrease and then increase. Correspondingly, the short contacts between the PDI moieties are first enhanced and then reduced. In particular, when the branching position is at the third carbon atom, the intermolecular connectivity becomes the most effective and the electron mobility is significantly increased by 2 times.展开更多
An efficient and accurate method for computing the equilibriurn reduced density matrix is presented for treating open quantum systems characterized by the systern-bath model. The method employs the rnultilayer nmltico...An efficient and accurate method for computing the equilibriurn reduced density matrix is presented for treating open quantum systems characterized by the systern-bath model. The method employs the rnultilayer nmlticonfiguration tirne-dependent Hartree theory for imag- inary time propagation and an importance sampling procedure for calculating the quantum mechanical trace. The method is applied to the spin-boson Harniltonian, which leads to ac- curate results in agreement with those produced by the rnulti-electronic-state path integral molecular dynamics method.展开更多
The effect of chromophores to the glass transition temperature of polyimide ensemble has been investigated by means of molecular dynamics simulation in conjunction with barrier analysis. Simulated Tg results indicated...The effect of chromophores to the glass transition temperature of polyimide ensemble has been investigated by means of molecular dynamics simulation in conjunction with barrier analysis. Simulated Tg results indicated a good agreement with experimental value. This study showed the MD simulation could estimate the effect of chromophores to the Tg of polyimide ensemble conveniently and an estimation approach method had a surprising deviation of Tg from experiment. At the same time, a polyimide structure with higher barrier energy was designed and validated by MD simulation.展开更多
The densities of n-pentane, methane-n-pentane, propane-n-pentane, n-heptane-n-pentane, and n-decane-n-pentane binary mixtures were determined at 476.5K in the pressure range from 2 to 5 MPa. The partial molar volumes ...The densities of n-pentane, methane-n-pentane, propane-n-pentane, n-heptane-n-pentane, and n-decane-n-pentane binary mixtures were determined at 476.5K in the pressure range from 2 to 5 MPa. The partial molar volumes of the solutes in n-pentane were calculated using the density data. It was found that the partial molar volumes of methane and propane are positive, while those of n-heptane and n-decane are negative.展开更多
For microelectronic devices,the on-chip microsupercapacitors with facile construction and high performance,are attracting researchers'prior consideration due to their high compatibility with modern microsystems.He...For microelectronic devices,the on-chip microsupercapacitors with facile construction and high performance,are attracting researchers'prior consideration due to their high compatibility with modern microsystems.Herein,we proposed interchanging interdigital Au-/MnO_(2)/polyethylene dioxythiophene stacked microsupercapacitor based on a microfabrication process followed by successive electrochemical deposition.The stacked configuration of two pseudocapacitive active microelectrodes meritoriously leads to an enhanced contact area between MnO_(2)and the conductive and electroactive layer of polyethylene dioxythiophene,hence providing excellent electron transport and diffusion pathways of electrolyte ions,resulting in increased pseudocapacitance of MnO_(2)and polyethylene dioxythiophene.The stacked quasi-solid-state microsupercapacitors delivered the maximum specific capacitance of 43 mF cm^(-2)(211.9 F cm^(-3)),an energy density of 3.8μWh cm^(-2)(at a voltage window of 0.8 V)and 5.1μWh cm^(-2)(at a voltage window of 1.0 V)with excellent rate capability(96.6%at 2 mA cm^(-2))and cycling performance of 85.3%retention of initial capacitance after 10000 consecutive cycles at a current density of 5 mA cm^(-2),higher than those of ever reported polyethylene dioxythiophene and MnO_(2)-based planar microsupercapacitors.Benefiting from the favorable morphology,bilayer microsupercapacitor is utilized as a flexible humidity sensor with a response/relaxation time superior to those of some commercially available integrated microsensors.This strategy will be of significance in developing high-performance on-chip integrated microsupercapacitors/microsensors at low cost and environment-friendly routes.展开更多
The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds ...The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity,good drug-loading ability and sustained drug release properties.As a typical example,hyaluronic acid dressing(Healoderm)has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers.However,the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment.Due to the intricacy of diabetic wounds,antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice,although these medications are easily hindered by the hostile environment.In this case,scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds(such as high glucose and low pH)or combined with external stimuli(such as light or magnetic field)to achieve controllable drug release,gel degradation,and microenvironment improvements in order to overcome these clinical issues.These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings.Here,we review recent advances on responsive-hydrogel dressings towards diabetic wound healing,with focus on hydrogel structure design,the principle of responsiveness,and the behavior of degradation.Last but not least,the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed.We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application.展开更多
Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets ...Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.展开更多
Photoelectrochemical (PEC) small-molecule oxidation can selectively transform substrates into high-value-added fine chemicals and increase the rate of cathode hydrogen evolution. Nevertheless, achieving high-selectivi...Photoelectrochemical (PEC) small-molecule oxidation can selectively transform substrates into high-value-added fine chemicals and increase the rate of cathode hydrogen evolution. Nevertheless, achieving high-selectivity PEC oxidation of small molecules to produce specific products is a very challenging task. In general, selectivity can be improved by changing the surface catalyticsites of the photoanode and modulating the interfacial environments of the reactions. Herein, recent advances in approaches to improving selective PEC oxidation of small molecules are introduced. We first briefly discuss the basic concept and fundamentals of small-molecule PEC oxidation. The reported approaches to improving the performance of selective PEC oxidation of small molecules are highlighted from two aspects: (1) changing the surface properties of photoanodes by selecting suitable materials or modifying the photoanodes and (2) mediating the oxidation reactions using redox mediators. The PEC oxidation mechanism of these studies is emphasized. We also discuss the challenges in this research direction and offer a perspective on the further development of selective PEC-based small-molecule transformation.展开更多
Solar-driven interfacial evaporation is a promising technology for freshwater production from seawater,but salt accumulation on the evaporator surface hinders its performance and sustainability.In this study,we report...Solar-driven interfacial evaporation is a promising technology for freshwater production from seawater,but salt accumulation on the evaporator surface hinders its performance and sustainability.In this study,we report a simple and green strategy to fabricate a three-dimensional porous graphene spiral roll(3GSR)that enables highly efficient solar evaporation,salt collection,and water production from near-saturated brine with zero liquid discharge(ZLD).The 3GSR design facilitates energy recovery,radial brine transport,and directional salt crystallization,thereby resulting in an ultrahigh evaporation rate of 9.05 kg m^(-2) h^(-1) in 25 wt%brine under 1-sun illumina-tion for 48 h continuously.Remarkably,the directional salt crystallization on its outer surface not only enlarges the evaporation area but also achieves an ultrahigh salt collection rate of 2.92 kg m^(-2) h^(-1),thus enabling ZLD desalination.Additionally,3GSR exhibits a record-high water production rate of 3.14 kg m^(-2) h^(-1) in an outdoor test.This innovative solution offers a highly efficient and continuous solar desalination method for water production and ZLD brine treatment,which has great implications for addressing global water scarcity and environmental issues arising from brine disposal.展开更多
To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic ef...To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.展开更多
This work focused on the anionic polymerization of octamethylcyclotetrasiloxane (D-4, D = Me2SiO2/2) initiated by a new kind of initiator hexamethydisilazyl-lithium (MMNLi). Si-29-NMR spectroscopy and gas chromatograp...This work focused on the anionic polymerization of octamethylcyclotetrasiloxane (D-4, D = Me2SiO2/2) initiated by a new kind of initiator hexamethydisilazyl-lithium (MMNLi). Si-29-NMR spectroscopy and gas chromatography (GC) were used to characterize the polymerization products. The process was accelerated by adding a small amount of high activity monomer D-3 and by raising the polymerization temperature. At the end of polymerization more than 95% of the monomer was converted to polymer and only a very small amount of D-4 and D-5 remained in the polymers.展开更多
Transforming growth factor-β (TGF-β) binds with two transmembrane serine/threonine kinase receptors, type Ⅱ (TβRII) and type Ⅰ receptors (TβRⅠ), and one accessory receptor, type Ⅲ receptor (TβRⅢ), to...Transforming growth factor-β (TGF-β) binds with two transmembrane serine/threonine kinase receptors, type Ⅱ (TβRII) and type Ⅰ receptors (TβRⅠ), and one accessory receptor, type Ⅲ receptor (TβRⅢ), to transduce signals across cell membranes. Previous biochemical studies suggested that TβRI and TβRIII are preexisted homo-dimers. Using single-molecule microscopy to image green fluorescent protein-labeled membrane proteins, for the first time we have demonstrated that TβRI and TβRⅢ could exist as monomers at a low expression level. Upon TGF-β1 stimu- lation, TβRI follows the general ligand-induced receptor dimerization model for activation, but this process is TβRⅡ- dependent. The monomeric status of the non-kinase receptor TβRⅢ is unchanged in the presence of TGF-β1. With the increase of receptor expression, both TβRI and TβRIII can be assembled into dimers on cell surfaces.展开更多
Lithium-sulfur(Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries.However,sulfur cathodes suffer from inherent problems of its poor electronic conductivity and...Lithium-sulfur(Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries.However,sulfur cathodes suffer from inherent problems of its poor electronic conductivity and the shuttling of highly dissoluble lithium polysulfides generated during the cycles.Loading sulfur into porous carbons has been proved to be an effective approach to alleviate these issues.Mesoporous and microporous carbons have been widely used for sulfur accommodation,but mesoporous carbons have poor sulfur confinement,whereas microporous carbons are impeded by low sulfur loading rates.Here,a core-shell carbon,combining both the merits of mesoporous carbon with large pore volume and microporous carbon with effective sulfur confinement,was prepared by coating the mesoporous CMK-3 with a microporous carbon(MPC) shell and served as the carbon host(CMK-3 @MPC) to accommodate sulfur.After sulfur infusion,the as-obtained S/(CMK-3@MPC) cathode delivered a high initial capacity of up to 1422 mAh·g-1 and sustained 654 mAh·g-1 reversible specific capacity after 36 cycles at 0.1 C.The good performance is ascribed to the unique core-shell structure of the CMK-3@MPC matrix,in which sulfur can be effectively confined within the meso/microporous carbon host,thus achieving simultaneously high electrochemical utilization.展开更多
The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the fur...The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the further enhancement of the PCE for polymer solar cells.Herein,we clarified the different effects of PFN and its derivatives,namely,poly[(9,9-bis(3’-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN-Br) in modifying fullerene-free PSCs.It is found for the first time that doping on IT-4F by the amino group of PFN leads to the unfavorable charge accumulation,and hence,forms a dense layer of electronegative molecule due to the poor electron transport capacity of the non-fullerene acceptor IT-4F.The electronegative molecular layer can block the electron transfer from the active layer to the interlayer and cause serious charge recombination at the active layer/cathode interface.This mechanism could be verified by the ESR measurement and electron-only devices.By replacing PFN with PFN-Br,the excessive doping effect between the cathode interlayer and IT-4F is eliminated,by which the charge transport and collection can be greatly improved.As a result,a high PCE of 13.5%was achieved in the fullerene-free PSCs.展开更多
The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pore...The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and thelayer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm themethodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.展开更多
The photocatalytic degradation of dye Rhodamine B (RhB) in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra...The photocatalytic degradation of dye Rhodamine B (RhB) in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra (IR spectra), ^1H nuclear magnetic resonance (^1HNMR) spectra, and gas chromatography-mass spectroscopy (GC-MS). The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems (TiO2 nanostfipe or P25 and Rhodamine B systems). GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway(s) for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.展开更多
基金supported by the National Natural Science Foundation of China(grant number 22309103)Natural Science Foundation of Shandong Province(grant numbers ZR2022MH162,ZR2022QE202)+1 种基金PhD Research Start-up Foundation of Qufu Normal University(grant numbers 614901,615201)the project of introduction and cultivation for young innovation talents in the colleges and universities of Shandong Province(grant number 614202).
文摘Tumors,due to their diversity and heterogeneity,pose a significant threat to human health.Multidrug resistance is a prevalent and grave issue in clinical treatment,resulting in treatment failure and cancer recurrence.This resistance renders conventional drug therapies ineffective,presenting a substantial challenge to human health and medical care.Exploring natural products as potential sources for anti-cancer drugs could lead to the development of innovative and efficacious cancer treatments.This article aims to investigate the health implications of natural products(such as paclitaxel,podophyllotoxin,homoharringtonine,camptothecin,and vinblastine)in the discovery of anti-cancer drugs while discussing the methods and progress made in researching novel anti-cancer drugs derived from natural products.The paper discusses the diversity,intricate structures,and target affinity of natural products along with their structural modification techniques,combination therapies utilization possibilities with prodrugs or nanoparticles.Additionally,considering the escalating multidrug resistance observed in tumors nowadays;certain natural products offer new insights and approaches for discovering effective anti-tumor drugs that are crucial for addressing global public health challenges.The challenges faced by natural products during drug development including issues related to bioavailability toxicity concerns as well as limited resources are examined thoroughly.Potential opportunities current issues along with future challenges are highlighted aiming at facilitating the clinical translation of original anti-cancer drugs using natural products.
基金supported by the National Natural Science Foundation of China (No.21773251 and No.91741106)the Beijing National Laboratory for Molecular Sciences and Chinese Academy of Sciences
文摘The van der Waals (vdW) interaction is very important in fields of physics, biology and chemistry, and its role in reaction dynamics is an issue of great interest. In this review, we focus on the recent progresses in the theoretical and experimental studies on the vdW interaction in bimolecular reactions. In particular, we review those studies that have advanced our understanding of how the vdW interaction can strongly influence the dynamics in both direct activated and complex-forming reactions, and further extend the discussion to the polyatomic reactions involving more atoms and those occurring at cold and ultracold temperatures. We indicate that an accurate description of the delicate vdW structure and long-range potential remains a challenge nowadays in either ab initio calculations or the fitting of the potential energy surfaces. We also present an explanation on the concept of vdW saddle proposed by us recently which may have general importance.
基金supported by the National Natural Science Foundation of China(No.21773251 and No.21973098)the Youth Innovation Promotion Association CAS(No.2018045)the Beijing National Laboratory for Molecular Sciences。
文摘Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very good descriptions of the regions around conical intersections and of van der Waals(vdW)interactions.The calculated reaction thermal rate coefficients are in very good agreement with the latest experimental results.The rate coefficients obtained from the ground˜a^(1)A′ZMB-a PES are much larger than those from the previous RKHS PES,which can be attributed to that the vdW saddles on our PESs have very different dynamical effects from the vdW wells on the previous PESs,indicating that the RPMD approach is able to include dynamical effects of the topological structures caused by vdW interactions.The importance of the excited˜b^(1)A′′ZMB-b PES and quantum effects in the title reaction is also underscored.
基金supported by the National Natural Science Foundation of China(Grant no.51773208,51803216)the Ministry of Science and Technology of China(Grant no.2014CB643506)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant no.XDB12020200)
文摘Side chains play a critical role in tuning intermolecular interaction and charge transport in organic semiconductors. Here, we have systematically investigated the impact of branching positions of the alkyl side chains on the molecular packing and electron transport properties of a series of bay-linked dimeric perylenediimide(PDI) derivatives by atomistic molecular dynamics simulations in combination with charge transfer rate theory and kinetic Monte Carlo simulations. The results show that despite of different branching positions of the alkyl chains,π–π stacking is effectively inhibited for all the dimeric PDI derivatives. As the branching position moves away from the PDI backbone, the appearance of the alkyl atoms around the PDI backbone will first decrease and then increase. Correspondingly, the short contacts between the PDI moieties are first enhanced and then reduced. In particular, when the branching position is at the third carbon atom, the intermolecular connectivity becomes the most effective and the electron mobility is significantly increased by 2 times.
基金supported by the U.S.National Science Foundation CHE-1500285used resources from the National Energy Research Scientific Computing Center,which is supported by the Office of Science of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231+2 种基金supported by the Ministry of Science and Technology of China(No.2017YFA0204901 and No.2016YFC0202803)the National Natural Science Foundation of China(No.21373018 and No.21573007)the Recruitment Program of Global Experts,and Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(the second phase) under grant No.U1501501
文摘An efficient and accurate method for computing the equilibriurn reduced density matrix is presented for treating open quantum systems characterized by the systern-bath model. The method employs the rnultilayer nmlticonfiguration tirne-dependent Hartree theory for imag- inary time propagation and an importance sampling procedure for calculating the quantum mechanical trace. The method is applied to the spin-boson Harniltonian, which leads to ac- curate results in agreement with those produced by the rnulti-electronic-state path integral molecular dynamics method.
基金This project has been supported by the National Natural Science FoundationChina Special Funds for Major Slate Basic Research Project(G1999064800).
文摘The effect of chromophores to the glass transition temperature of polyimide ensemble has been investigated by means of molecular dynamics simulation in conjunction with barrier analysis. Simulated Tg results indicated a good agreement with experimental value. This study showed the MD simulation could estimate the effect of chromophores to the Tg of polyimide ensemble conveniently and an estimation approach method had a surprising deviation of Tg from experiment. At the same time, a polyimide structure with higher barrier energy was designed and validated by MD simulation.
基金the National Natural Science Foundation of China for the financial support(29725308,29633020)
文摘The densities of n-pentane, methane-n-pentane, propane-n-pentane, n-heptane-n-pentane, and n-decane-n-pentane binary mixtures were determined at 476.5K in the pressure range from 2 to 5 MPa. The partial molar volumes of the solutes in n-pentane were calculated using the density data. It was found that the partial molar volumes of methane and propane are positive, while those of n-heptane and n-decane are negative.
基金the financial support of the National Key R&D Program of China(Grant Nos.2021YFB3200701 and 2018YFA0208501)the National Natural Science Foundation of China(Grant Nos.21875260,21671193,91963212,51773206,21731001,and 52272098)Beijing Natural Science Foundation(No.2202069)
文摘For microelectronic devices,the on-chip microsupercapacitors with facile construction and high performance,are attracting researchers'prior consideration due to their high compatibility with modern microsystems.Herein,we proposed interchanging interdigital Au-/MnO_(2)/polyethylene dioxythiophene stacked microsupercapacitor based on a microfabrication process followed by successive electrochemical deposition.The stacked configuration of two pseudocapacitive active microelectrodes meritoriously leads to an enhanced contact area between MnO_(2)and the conductive and electroactive layer of polyethylene dioxythiophene,hence providing excellent electron transport and diffusion pathways of electrolyte ions,resulting in increased pseudocapacitance of MnO_(2)and polyethylene dioxythiophene.The stacked quasi-solid-state microsupercapacitors delivered the maximum specific capacitance of 43 mF cm^(-2)(211.9 F cm^(-3)),an energy density of 3.8μWh cm^(-2)(at a voltage window of 0.8 V)and 5.1μWh cm^(-2)(at a voltage window of 1.0 V)with excellent rate capability(96.6%at 2 mA cm^(-2))and cycling performance of 85.3%retention of initial capacitance after 10000 consecutive cycles at a current density of 5 mA cm^(-2),higher than those of ever reported polyethylene dioxythiophene and MnO_(2)-based planar microsupercapacitors.Benefiting from the favorable morphology,bilayer microsupercapacitor is utilized as a flexible humidity sensor with a response/relaxation time superior to those of some commercially available integrated microsensors.This strategy will be of significance in developing high-performance on-chip integrated microsupercapacitors/microsensors at low cost and environment-friendly routes.
基金This work was supported by the National Key Research and Development Program of China(2020YFA0908100)the National Natural Science Foundation of China(81972081,81971724,81773661,51973226 and 82173750)+2 种基金the Youth Innovation Promotion Association CAS(2019031)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2020R01018,2021B42001 and 2022C02037)the A*STAR Research Grant for Support of This Project.
文摘The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem.Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity,good drug-loading ability and sustained drug release properties.As a typical example,hyaluronic acid dressing(Healoderm)has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers.However,the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment.Due to the intricacy of diabetic wounds,antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice,although these medications are easily hindered by the hostile environment.In this case,scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds(such as high glucose and low pH)or combined with external stimuli(such as light or magnetic field)to achieve controllable drug release,gel degradation,and microenvironment improvements in order to overcome these clinical issues.These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings.Here,we review recent advances on responsive-hydrogel dressings towards diabetic wound healing,with focus on hydrogel structure design,the principle of responsiveness,and the behavior of degradation.Last but not least,the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed.We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application.
基金the funding from Natural Science Foundation of China(No.52003163)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010670)+1 种基金Science and Technology Innovation Commission of Shenzhen(Nos.KQTD20170810105439418 and 20200812112006001)NTUT-SZU Joint Research Program(Nos.2022005 and 2022015)
文摘Developing a simple scalable method to fabricate electrodes with high capacity and wide voltage range is desired for the real use of electrochemical supercapacitors.Herein,we synthesized amorphous NiCo-LDH nanosheets vertically aligned on activated carbon cloth substrate,which was in situ transformed from Co-metal-organic framework materials nano-columns by a simple ion exchange process at room temperature.Due to the amorphous and vertically aligned ultrathin structure of NiCo-LDH,the NiCo-LDH/activated carbon cloth composites present high areal capacities of 3770 and 1480 mF cm^(-2)as cathode and anode at 2 mA cm^(-2),and 79.5%and 80%capacity have been preserved at 50 mA cm^(-2).In the meantime,they all showed excellent cycling performance with negligible change after>10000 cycles.By fabricating them into an asymmetric supercapacitor,the device achieves high energy densities(5.61 mWh cm^(-2)and 0.352 mW cm^(-3)).This work provides an innovative strategy for simplifying the design of supercapacitors as well as providing a new understanding of improving the rate capabilities/cycling stability of NiCo-LDH materials.
基金the National Natural Science Foundation of China (No. 22136005)the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDB36000000).
文摘Photoelectrochemical (PEC) small-molecule oxidation can selectively transform substrates into high-value-added fine chemicals and increase the rate of cathode hydrogen evolution. Nevertheless, achieving high-selectivity PEC oxidation of small molecules to produce specific products is a very challenging task. In general, selectivity can be improved by changing the surface catalyticsites of the photoanode and modulating the interfacial environments of the reactions. Herein, recent advances in approaches to improving selective PEC oxidation of small molecules are introduced. We first briefly discuss the basic concept and fundamentals of small-molecule PEC oxidation. The reported approaches to improving the performance of selective PEC oxidation of small molecules are highlighted from two aspects: (1) changing the surface properties of photoanodes by selecting suitable materials or modifying the photoanodes and (2) mediating the oxidation reactions using redox mediators. The PEC oxidation mechanism of these studies is emphasized. We also discuss the challenges in this research direction and offer a perspective on the further development of selective PEC-based small-molecule transformation.
基金This work was supported by the Taishan Young Scholar Program(tsqn202306267)the National Natural Science Foundation of China(51802168)the Natural Science Foundation of Shandong Province(ZR2023ME172).
文摘Solar-driven interfacial evaporation is a promising technology for freshwater production from seawater,but salt accumulation on the evaporator surface hinders its performance and sustainability.In this study,we report a simple and green strategy to fabricate a three-dimensional porous graphene spiral roll(3GSR)that enables highly efficient solar evaporation,salt collection,and water production from near-saturated brine with zero liquid discharge(ZLD).The 3GSR design facilitates energy recovery,radial brine transport,and directional salt crystallization,thereby resulting in an ultrahigh evaporation rate of 9.05 kg m^(-2) h^(-1) in 25 wt%brine under 1-sun illumina-tion for 48 h continuously.Remarkably,the directional salt crystallization on its outer surface not only enlarges the evaporation area but also achieves an ultrahigh salt collection rate of 2.92 kg m^(-2) h^(-1),thus enabling ZLD desalination.Additionally,3GSR exhibits a record-high water production rate of 3.14 kg m^(-2) h^(-1) in an outdoor test.This innovative solution offers a highly efficient and continuous solar desalination method for water production and ZLD brine treatment,which has great implications for addressing global water scarcity and environmental issues arising from brine disposal.
基金supported by National Natural Science Foundation of China (22033009, 22121002, 22238011)。
文摘To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.
文摘This work focused on the anionic polymerization of octamethylcyclotetrasiloxane (D-4, D = Me2SiO2/2) initiated by a new kind of initiator hexamethydisilazyl-lithium (MMNLi). Si-29-NMR spectroscopy and gas chromatography (GC) were used to characterize the polymerization products. The process was accelerated by adding a small amount of high activity monomer D-3 and by raising the polymerization temperature. At the end of polymerization more than 95% of the monomer was converted to polymer and only a very small amount of D-4 and D-5 remained in the polymers.
基金This work was supported by the National Natural Science Foundation of China (90713024, 20821003, 30921004), the National Basic Research Program of China (2007CB935601, 2010CB833706) and the Chinese Academy of Sciences.
文摘Transforming growth factor-β (TGF-β) binds with two transmembrane serine/threonine kinase receptors, type Ⅱ (TβRII) and type Ⅰ receptors (TβRⅠ), and one accessory receptor, type Ⅲ receptor (TβRⅢ), to transduce signals across cell membranes. Previous biochemical studies suggested that TβRI and TβRIII are preexisted homo-dimers. Using single-molecule microscopy to image green fluorescent protein-labeled membrane proteins, for the first time we have demonstrated that TβRI and TβRⅢ could exist as monomers at a low expression level. Upon TGF-β1 stimu- lation, TβRI follows the general ligand-induced receptor dimerization model for activation, but this process is TβRⅡ- dependent. The monomeric status of the non-kinase receptor TβRⅢ is unchanged in the presence of TGF-β1. With the increase of receptor expression, both TβRI and TβRIII can be assembled into dimers on cell surfaces.
基金supported by the National Natural Science Foundation of China(Grant No.51225204,91127044,U1301244 and 21121063)the National Key Project on Basic Research(Grant No.2011CB935700,2013AA050903 and 2012CB932900)the"Strategic Priority Research Program"of CAS(Grant No.XDA09010300)
文摘Lithium-sulfur(Li-S) batteries belong to one of the promising technologies for high-energy-density rechargeable batteries.However,sulfur cathodes suffer from inherent problems of its poor electronic conductivity and the shuttling of highly dissoluble lithium polysulfides generated during the cycles.Loading sulfur into porous carbons has been proved to be an effective approach to alleviate these issues.Mesoporous and microporous carbons have been widely used for sulfur accommodation,but mesoporous carbons have poor sulfur confinement,whereas microporous carbons are impeded by low sulfur loading rates.Here,a core-shell carbon,combining both the merits of mesoporous carbon with large pore volume and microporous carbon with effective sulfur confinement,was prepared by coating the mesoporous CMK-3 with a microporous carbon(MPC) shell and served as the carbon host(CMK-3 @MPC) to accommodate sulfur.After sulfur infusion,the as-obtained S/(CMK-3@MPC) cathode delivered a high initial capacity of up to 1422 mAh·g-1 and sustained 654 mAh·g-1 reversible specific capacity after 36 cycles at 0.1 C.The good performance is ascribed to the unique core-shell structure of the CMK-3@MPC matrix,in which sulfur can be effectively confined within the meso/microporous carbon host,thus achieving simultaneously high electrochemical utilization.
基金the financial support from NSFC(21325419,21504095,and 51373181)the Chinese Academy of Science(XDB12030200,KJZD-EW-J01)。
文摘The modification mechanism of the water/alcohol cathode interlayer is one of the most complicated problems in the field of organic photovoltaics,which has not been clearly elucidated yet;this greatly restricts the further enhancement of the PCE for polymer solar cells.Herein,we clarified the different effects of PFN and its derivatives,namely,poly[(9,9-bis(3’-((N,N-dimethyl)-N-ethylammonium)-propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)](PFN-Br) in modifying fullerene-free PSCs.It is found for the first time that doping on IT-4F by the amino group of PFN leads to the unfavorable charge accumulation,and hence,forms a dense layer of electronegative molecule due to the poor electron transport capacity of the non-fullerene acceptor IT-4F.The electronegative molecular layer can block the electron transfer from the active layer to the interlayer and cause serious charge recombination at the active layer/cathode interface.This mechanism could be verified by the ESR measurement and electron-only devices.By replacing PFN with PFN-Br,the excessive doping effect between the cathode interlayer and IT-4F is eliminated,by which the charge transport and collection can be greatly improved.As a result,a high PCE of 13.5%was achieved in the fullerene-free PSCs.
基金This work was supported by the National Natural Science Foundation of China (No. 20023003 and 20128004).
文摘The anodic porous alumina membranes with a definite pore diameter and aspect ratio were used as templates tosynthesize polymer pillared layer structures. The pillared polymer was produced in the template membrane pores, and thelayer on the template surfaces. Rigid cured epoxy resin, polystyrene and soft hydrogel were chosen to confirm themethodology. The pillars were in the form of either tubes or fibers, which were controlled by the alumina membrane pore surface wettability. The structural features were confirmed by scanning electron microscopy results.
基金Project supported by the National Natural Science Foundation of China(No. 20567002)the Scientific Research Startup Foundation of InnerMongolia University (No. 203044)+2 种基金the Education Department of InnerMongolia Autonomous Region (No. NJ04093, NJ03121)the ChunhuiPlan of the Education Ministry (No. Z2004-2-15030)the "513 TalentsPlan" of Inner Mongolia University.
文摘The photocatalytic degradation of dye Rhodamine B (RhB) in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra (IR spectra), ^1H nuclear magnetic resonance (^1HNMR) spectra, and gas chromatography-mass spectroscopy (GC-MS). The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems (TiO2 nanostfipe or P25 and Rhodamine B systems). GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway(s) for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.