Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand...Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.展开更多
Selenolate ligands are expected to endow fluorescent gold nanoclusters(AuNCs)with better stability and more bioactivity than thiolate ligands,making them promising in the biological field.However,there are few studies...Selenolate ligands are expected to endow fluorescent gold nanoclusters(AuNCs)with better stability and more bioactivity than thiolate ligands,making them promising in the biological field.However,there are few studies on the synthesis of water-soluble selenolate-protected AuNCs,and the impact of selenolate ligands on the optical properties of AuNCs is still unclear.In this study,we synthesized selenolatecostabilized water-soluble,near-infrared fluorescent AuNCs with four different amounts of benzeneselenol(PhSeH),and systematically investigated the role of PhSeH on their optical properties.It is discovered that an appropriate PhSeH content is favorable for the fluorescence enhancement of AuNCs due to the ligand to metal charge transfer effect.Moreover,AuNCs co-stabilized by selenolate ligands exhibit better photostability and long-term stability compared with AuNCs stabilized by thiolate ligands,owing to the introduction of Au-Se bond on their surfaces.Further cellular experiments revealed that selenolate ligands can also affect the cellular uptake efficiency of AuNCs and their imaging property.These results provide important knowledges for further development of new,robust selenolate-stabilized metal NCs for biological application.展开更多
BACKGROUND We previously demonstrated that the antibody against programmed cell death protein 1 ligand 1(PDCD1 LG1)is a promising new marker of programmed death-ligand 1(PD-L1)expression that correlates with both brea...BACKGROUND We previously demonstrated that the antibody against programmed cell death protein 1 ligand 1(PDCD1 LG1)is a promising new marker of programmed death-ligand 1(PD-L1)expression that correlates with both breast cancer(BC)clinicopathological characteristics and tumor sensitivity to chemotherapy.However,the concordance of PDCD1 LG1 expression scoring with immunohistochemical(IHC)tests approved for clinical use and with the polymerase chain reaction(PCR)method has not been previously studied.AIM To evaluate the concordance of methods for assessing PD-L1 expression,IHC tests with anti-PD-L1(PDCD1 LG1)and anti-PD-L1(SP142)antibodies and PCR.METHODS This prospective single-center observational cohort study included 148 patients with BC.PD-L1 expression in immune cells was assessed by the IHC method with anti-PD-L1(PDCD1 LG1)and anti-PD-L1(SP142)antibodies and by PCR.The concordance of PD-L1 scores between tests was assessed with positive percentage agreement(PPA)and negative percentage agreement(NPA).The strength of the agreement between the methods was calculated via the Cohen kappa index.P<0.05 was considered statistically significant.RESULTS Regardless of the method used to assess marker expression,PD-L1 expression was significantly more often detected in patients with negative estrogen receptor status,human epidermal growth factor receptor-2-positive(HER2+)status,luminal B HER+BC,nonluminal HER+BC and triple-negative BC.PPA and NPA were 38.3%and 70.4%,respectively,for PD-L1(PDCD1 LG1)and PD-L1(SP142);26.3%and 63.3%,respectively,for PD-L1(PDCD1 LG1)and PD-L1(PCR);and 36.5%and 74.4%,respectively,for PD-L1(SP142)and PD-L1(PCR).Cohen's kappa index for PD-L1(PDCD1 LG1)and PD-L1(SP142)was 0.385(95%CI:0.304–0.466),that for PD-L1(PDCD1 LG1)and PD-L1(PCR)was 0.207(95%CI:0.127–0.287),and that for PD-L1(SP142)and PD-L1(PCR)was 0.389(95%CI:0.309–0.469).CONCLUSION Thus,all three markers of PD-L1 expression are associated with the characteristics of aggressive BC,demonstrating moderate concordance between the tests.展开更多
(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under...(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.展开更多
Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachm...Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.展开更多
Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-d...Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as vip molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.展开更多
To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(...To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2.展开更多
The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogena...The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogenation of olefins often result in unexpected products and other by-products.Recent efforts in developing efficient ligands represent the most effective approach to addressing these challenges.In this study,we described a Bis-OPNN phosphorus ligand facilitated Rh-catalyzed hydroformylation with a high degree of linear selectivity across various olefins.Under mild conditions,a broad range of olefins were efficiently converted into linear aldehydes with high yields and excellent regioselectivity.The protocol also showed impressive functional group tolerance and was successfully applied to modify drugs and natural products,including the total synthesis of(±)-crispine A.Preliminary mechanistic studies revealed that this Bis-OPNN phosphorus ligand anchoring the rhodium catalyst is crucial for controlling the linear selectivity.展开更多
Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study...Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.展开更多
Regulating the photo-response region of iron metal-organic frameworks(Fe-MOFs)is a viable strategy for enhancing their practical application in the visible-light driven photo-Fenton-like process.This study developed a...Regulating the photo-response region of iron metal-organic frameworks(Fe-MOFs)is a viable strategy for enhancing their practical application in the visible-light driven photo-Fenton-like process.This study developed a novel pyrazine-based Fe-MOFs(MIL-101(Fe)-Pz)by substituting the 1,4-dicarboxybenzene acid ligands in typical MIL-101(Fe)with 2,5-pyrazinedicarboxylic acid(PzDC),in which sodium acetate was used as coordinative modulator to control the crystal size(2–3μm).The incorporation of Fe-pyridine N coordination structures originated from PzDC ligands gave MIL-101(Fe)-Pz narrowed band gap(1.45 eV)than MIL-101(Fe)(2.54 eV)resulting in improved visible-light adsorption capacity(λ>420 nm),and also increased the proportion of Fe(Ⅱ)in the Fe-clusters.Thus MIL-101(Fe)-Pz exhibited a synergistic enhanced photo-Fenton-like catalytic performance under visible-light irradiation.The MIL-101(Fe)-Pz/H_(2)O_(2)/Vis system could degrade 99%of sulfamethoxazolewithin 30min,whichwas 10-fold faster than that of the pristine MIL-101(Fe),it also effectively removed other organic micropollutants with high durability and stability.Mechanistic analysis revealed that the PzDC ligands substitution decreased the band gap of MIL-101(Fe),giving MIL-101(Fe)-Pz appropriate band structure(-0.40∼1.05 V vs.NHE)which can cover several light-driven process for the generation of reactive oxygen species,including Fe(Ⅲ)reduction and H_(2)O_(2) activation for accelerating•OH generation,as well as oxygen reduction reaction for generating H_(2)O_(2),O_(2)^(•−) and ^(1)O_(2).This study highlights the role of pyridine-N containing ligands in regulating the band structure of Fe-MOFs,providing valuable guidance for the design of Fe-MOFs photocatalysts.展开更多
A strategy for copper-catalyzed and biphosphine ligand controlled boracarboxylation of 1,3-dienes and CO_(2) with 3,4-selectivity was developed.The Cu Cl coupled with DPPF(1,1-bis(diphenylphosphino)ferrocene)was assig...A strategy for copper-catalyzed and biphosphine ligand controlled boracarboxylation of 1,3-dienes and CO_(2) with 3,4-selectivity was developed.The Cu Cl coupled with DPPF(1,1-bis(diphenylphosphino)ferrocene)was assigned to be the best catalyst,with 84%yield and exclusive3,4-selectivity.The ligand effect on both catalytic activity and regioselectivity of boracarboxylation was disclosed,which is rarely reported in any copper catalyzed boracarboxylation.The borocupration process is revealed to be a vital step for the biphosphine participated boracarboxylation of 1,3-dienes with CO_(2).The minimal substrate distortion occurring in 3,4-borocupration favors the 3,4-regioselectivity of boracarboxylation.The“pocket”confinement and suitableβ_(n)(92°–106°)of bisphosphine ligands are demonstrated to be in favour of the interaction between LCu-Bpin complex(the catalytic precursor)and1,3-diene substrate to decrease their interaction energyΔE_(int)(ζ)in 3,4-borocupration,thus promoting the 3,4-boracarboxylation.展开更多
Formamidinium lead bromide(FAPbBr_(3))perovskite nanocrystals(NCs)are promising for display and lighting due to their ultra-pure green emission.However,the thermal quenching will exacerbate their performance degradati...Formamidinium lead bromide(FAPbBr_(3))perovskite nanocrystals(NCs)are promising for display and lighting due to their ultra-pure green emission.However,the thermal quenching will exacerbate their performance degradation in practical applications,which is a common issue for halide perovskites.Here,we reported the heat-resistant FAPbBr_(3)NCs prepared by a ligand-engineered room-temperature synthesis strategy.An aromatic amine,specificallyβ-phenylethylamine(PEA)or 3-fluorophenylethylamine(3-F-PEA),was incoporated as the short-chain ligand to expedite the crystallization rate and control the size distribution of FAPbBr_(3)NCs.Employing this ligand engineering approach,we synthesized high quality FAPbBr_(3)NCs with uniform grain size and reduced long-chain alkyl ligands,resulting in substantially suppressed thermal quenching and enhanced carrier transportation in the perovskite NCs films.Most notably,more than 90%of the room temperature PL intensity in the 3-F-PEA modified FAPbBr_(3)NCs film was preserved at 380 K.Consequently,we fabricated ultra-pure green EL devices with a room temperature external quantum efficiency(EQE)as high as 21.9%at the luminance of above 1,000 cd m^(-2),and demonstrated less than 10%loss in EQE at 343 K.This study introduces a novel room temperature method to synthesize efficient FAPbBr_(3)NCs with exceptional thermal stability,paving the way for advanced optoelectronic device applications.展开更多
Pt-rare-earth(PtRE)alloys are considered to be highly promising catalysts for oxygen reduction reaction(ORR)in acidic electrolytes.However,the wet-chemical synthesis of PtRE nanoalloys still faces significant challeng...Pt-rare-earth(PtRE)alloys are considered to be highly promising catalysts for oxygen reduction reaction(ORR)in acidic electrolytes.However,the wet-chemical synthesis of PtRE nanoalloys still faces significant challenges.The precise reaction mechanism for ORR of these catalysts is still unclear on significant aspects involving the rate-determining step and the nature of the ligand effect.Herein,we report a class of solvothermal synthesis of PtRE(RE is Dy or La)nanoalloys.Such PtRE nanoalloys here are active and stable in acidic media,with both high mass activities enhanced by 2-5 times relative to commercial Pt/C catalyst and high stabilities indicative of the little activity decay and negligible structure change after 10,000 cycles.Density functional theory calculations firmly confirm that the ligand effect of RE elements accelerates an O-O bond scission and steers the rate-determining steps from OH^(*)+H^(+)+e-→H_(2)O(on pure Pt surface)to HOOH^(*)+H^(+)+e-→OH^(*)+H_(2)O(on the PtRE nanoalloy surface)for the fast reaction kinetics,which could be fine-tuned by regulating the RE electronic structures and consequently endows the maximal rate of ORR catalysis with PtDy alloy catalysts.展开更多
BACKGROUND In recent years,emerging clinical research has prioritized assessment of combined therapeutic efficacy and safety parameters when programmed death 1 or its ligand(PD-1/L1)inhibitors are incorporated into fi...BACKGROUND In recent years,emerging clinical research has prioritized assessment of combined therapeutic efficacy and safety parameters when programmed death 1 or its ligand(PD-1/L1)inhibitors are incorporated into first-line standard-of-care(SOC)therapy for metastatic colorectal cancer(mCRC).However,data obtained from these trials demonstrated conflicting evidence concerning survival benefits and clinical outcomes.AIM To evaluate the therapeutic impact and safety parameters of combining PD-1/L1 inhibitors with SOC protocols as first-line treatment for mCRC.METHODS Four biomedical databases(PubMed,Embase,Cochrane Library,Web of Science)were systematically interrogated to identify eligible studies published up to October 12,2024.The analysis focused on evaluating the primary outcome of overall survival(OS)in the mCRC population with secondary outcomes of progression-free survival(PFS),overall response rate(ORR),and incidence rate of grade≥3 adverse events.Additionally,we performed exploratory analyses in the microsatellite stable/mismatch repair-proficient(MSS/pMMR)subpopulation,based on a subset of the included studies.Subgroup analyses according to PD-1/L1 inhibitor use were conducted in both the overall population and the MSS/pMMR subgroup.RESULTS This pooled analysis incorporated six randomized controlled trials involving 675 patients with mCRC receiving first-line therapy.The combination of PD-1/L1 inhibitors with SOC regimens demonstrated a significant PFS advantage over SOC monotherapy in intention-to-treat populations[hazard ratio(HR)=0.8,95%confidence interval(CI):0.65-0.98,P=0.033].Nevertheless,the MSS/pMMR subgroup showed no PFS benefit(HR=0.83,95%CI:0.67-1.03,P=0.091),and no cohort exhibited OS improvement(intention-to-treat:HR=0.84,95%CI:0.66-1.05,P=0.124;MSS/pMMR:HR=0.79,95%CI:0.60-1.03,P=0.083).Comparable outcomes were observed for ORR(risk ratio=1.03,95%CI:0.90-1.17,P=0.711)and incidence rate of grade≥3 adverse events(risk ratio=1.12,95%CI:0.93-1.36,P=0.245)between treatment arms.CONCLUSION The findings indicated that integrating PD-1/L1 blocking agents with SOC regimens for mCRC as first-line treatment failed to demonstrate significant improvements in ORR.Existing clinical data remain inadequate to establish OS advantages,particularly in patients with MSS/pMMR,despite exhibiting manageable toxicity profiles.Subsequent confirmation through rigorously designed phase III clinical trials remains essential to verify these therapeutic outcomes.展开更多
The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates ...The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.展开更多
Perovskite solar cells(PSCs)are promising in the field of photovoltaics but are hindered by surface defects and stability.However,the energetic losses occurring at the interfaces between the perovskite and the charge ...Perovskite solar cells(PSCs)are promising in the field of photovoltaics but are hindered by surface defects and stability.However,the energetic losses occurring at the interfaces between the perovskite and the charge transport layers often lead to reduced power conversion efficiency(PCE).Surface treatment is an effective strategy but the passivating ligands usually bind with a single active site.The resulted dense packing of resistive passivators perpendicular to the surface is detrimental to charge transport.Here,we present a passivator that can bind to two neighboring lead(Ⅱ)ion(Pb^(2+))defect sites simultaneously with an aligned parallel mode to the perovskite surface,effectively suppressing the surface trap density and preventing the aggregation.The target device fulfills a PCE of 25.1%and maintains over 85% of the initial efficiency after 800 h of exposure to a relative humidity(RH)of 65%±5%.展开更多
Electrocatalytic valorization of disused poly(ethylene terephthalate)(PET)plastics into value-added chemicals emerges as a potential approach to address plastic pollution and resources upgrading,but it faces challenge...Electrocatalytic valorization of disused poly(ethylene terephthalate)(PET)plastics into value-added chemicals emerges as a potential approach to address plastic pollution and resources upgrading,but it faces challenges in the development of efficient catalysts for PET-derived ethylene glycol(EG)electrooxidation.Herein,we proposed pyramid arrays on sheet Fe-doped NiO/FeNi_(3)(SPA-NiFeO_(x)/FeNi_(3))heterostructure,which is derived from the pyrolysis of MOF-on-MOF heterostructure growth triggered by graphene quantum dots(GQDs).Such SPA-NiFeO_(x)/FeNi_(3)exhibits superior catalytic performance on the electrooxidation of EG(EGOR)from PET hydrolysate,with a formic acid(FA)selectivity of 91.5%and a Faradaic efficiency of 92%.The ligand effect of GQDs in both the catalyst design and improved electrocatalytic performance was studied with combined spectroscopy analysis and theoretical calculations,which revealed that such spatially separated NiFeO_(x)and FeNi_(3)components by GQDs possess more active sites to anticipate in electrocatalytic EGOR,and the large sp2 domains in GQDs possess a strong electron-withdrawing ability to reduce the electron density of bonded Ni and Fe,resulting in high-valenced Ni^(δ+)/Fe^(δ+)in FeNi_(3)and Ni(2+δ)in NiO,respectively.Furthermore,the coordination number of Ni and Fe centers was lowered due to the steric effect of GQDs.Therefore,the adsorption of EG on Ni^(δ+)for cascade dehydrogenation and C–C bond cleavage led to adsorbed FA that transferred to adjacent Fe for desorption,which was promoted by the enrichment of OH−on nearby Ni^((2+δ))sites,along with optimized Gibbs free energy change in the multistep reaction pathway.This work provides an efficient multi-active-site catalyst for disused PET plastics valorization,thereby presenting a new approach to enhance the efficiency of PET plastics valorization reactions.展开更多
Metal nanoclusters(MNCs)possess distinct chemical properties due to their diverse electronic structures.As a class of promising model catalysts,it is of importance to explore the relationship between their structures ...Metal nanoclusters(MNCs)possess distinct chemical properties due to their diverse electronic structures.As a class of promising model catalysts,it is of importance to explore the relationship between their structures and properties.However,it is still challenging to get highly active and stable MNCs as surface ligands can hinder their activities,while a complete lack of surface ligand protection can lead to instability.To address this concern,here a series of Pd_(6)nanoclusters(NCs)with varying ligand amounts were synthesized by using Pd_(6)(SC_(6)(C_(2))H_(17))_(12)as precursor and single-walled carbon nanotube(s-CNT)as carrier through treating the composite at different temperatures and times.展开更多
An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthrolin...An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.展开更多
BACKGROUND In vivo degradation of bone scaffolds is significantly influenced by osteoclast(OC)activity,which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand(RANKL)and osteo...BACKGROUND In vivo degradation of bone scaffolds is significantly influenced by osteoclast(OC)activity,which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand(RANKL)and osteoprotegerin(OPG).The ratio of RANKL/OPG is a crucial determinant of OC-mediated bone resorption,which plays an integral role in bone remodeling and scaffold degradation.Elevated levels of RANKL relative to OPG enhance osteoclastogenesis,thereby accelerating the degradation process essential for integrating bone scaffolds into the host tissue.AIM To elucidate the effects of OPG gene silencing on osteoclastogenesis within rat bone marrow-derived mesenchymal stem cells(BMSCs).By investigating these effects,the study aimed to provide deeper insights into the regulatory mechanisms that influence bone scaffold degradation,potentially leading to improved bone repair and regeneration strategies.METHODS We employed recombinant lentiviral plasmids to silence the OPG gene in rat BMSCs to achieve the aims.The efficacy of gene silencing was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis to measure the expression levels of OPG and RANKL.Tartrate-resistant acid phosphatase staining was utilized to evaluate the formation of OCs.Additionally,co-immunoprecipitation assays were conducted to explore the interactions between RANKL and OPG proteins,further assessing the biochemical pathways involved in osteoclastogenesis.RESULTS The silencing of the OPG gene in BMSCs resulted in a significant increase in the RANKL/OPG ratio,evidenced by decreased expression levels of OPG and increased levels of RANKL.Enhanced osteoclastogenesis was observed through tartrate-resistant acid phosphatase staining,which indicated a substantial rise in OC formation in response to the altered RANKL/OPG balance.The co-immunoprecipitation assays provided concrete evidence of the direct interaction between RANKL and OPG proteins,substantiating their pivotal roles in regulating OC activity.CONCLUSION The findings from this study underscore the critical role of the RANKL/OPG axis in osteoclastogenesis.Silencing of the OPG gene in BMSCs effectively increases the RANKL/OPG ratio,promoting OC activity and potentially enhancing bone scaffold degradation.This regulatory mechanism offers a promising avenue for modulating bone remodeling processes,which is essential for effective bone repair and the successful integration of bone scaffolds into damaged sites.Future research might focus on optimizing the control of this axis to better facilitate bone tissue engineering and regenerative therapies.展开更多
基金supported by the National Natural Science Foundation of China(Key Program),No.11932013the National Natural Science Foundation of China(General Program),No.82272255+2 种基金Armed Police Force High-Level Science and Technology Personnel ProjectThe Armed Police Force Focuses on Supporting Scientific and Technological Innovation TeamsKey Project of Tianjin Science and Technology Plan,No.20JCZDJC00570(all to XC)。
文摘Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury.
基金support from the National Natural Science Foundation of China(No.22274131)Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHQ071)。
文摘Selenolate ligands are expected to endow fluorescent gold nanoclusters(AuNCs)with better stability and more bioactivity than thiolate ligands,making them promising in the biological field.However,there are few studies on the synthesis of water-soluble selenolate-protected AuNCs,and the impact of selenolate ligands on the optical properties of AuNCs is still unclear.In this study,we synthesized selenolatecostabilized water-soluble,near-infrared fluorescent AuNCs with four different amounts of benzeneselenol(PhSeH),and systematically investigated the role of PhSeH on their optical properties.It is discovered that an appropriate PhSeH content is favorable for the fluorescence enhancement of AuNCs due to the ligand to metal charge transfer effect.Moreover,AuNCs co-stabilized by selenolate ligands exhibit better photostability and long-term stability compared with AuNCs stabilized by thiolate ligands,owing to the introduction of Au-Se bond on their surfaces.Further cellular experiments revealed that selenolate ligands can also affect the cellular uptake efficiency of AuNCs and their imaging property.These results provide important knowledges for further development of new,robust selenolate-stabilized metal NCs for biological application.
基金Supported by Russian Science Foundation,No.23-25-00183.
文摘BACKGROUND We previously demonstrated that the antibody against programmed cell death protein 1 ligand 1(PDCD1 LG1)is a promising new marker of programmed death-ligand 1(PD-L1)expression that correlates with both breast cancer(BC)clinicopathological characteristics and tumor sensitivity to chemotherapy.However,the concordance of PDCD1 LG1 expression scoring with immunohistochemical(IHC)tests approved for clinical use and with the polymerase chain reaction(PCR)method has not been previously studied.AIM To evaluate the concordance of methods for assessing PD-L1 expression,IHC tests with anti-PD-L1(PDCD1 LG1)and anti-PD-L1(SP142)antibodies and PCR.METHODS This prospective single-center observational cohort study included 148 patients with BC.PD-L1 expression in immune cells was assessed by the IHC method with anti-PD-L1(PDCD1 LG1)and anti-PD-L1(SP142)antibodies and by PCR.The concordance of PD-L1 scores between tests was assessed with positive percentage agreement(PPA)and negative percentage agreement(NPA).The strength of the agreement between the methods was calculated via the Cohen kappa index.P<0.05 was considered statistically significant.RESULTS Regardless of the method used to assess marker expression,PD-L1 expression was significantly more often detected in patients with negative estrogen receptor status,human epidermal growth factor receptor-2-positive(HER2+)status,luminal B HER+BC,nonluminal HER+BC and triple-negative BC.PPA and NPA were 38.3%and 70.4%,respectively,for PD-L1(PDCD1 LG1)and PD-L1(SP142);26.3%and 63.3%,respectively,for PD-L1(PDCD1 LG1)and PD-L1(PCR);and 36.5%and 74.4%,respectively,for PD-L1(SP142)and PD-L1(PCR).Cohen's kappa index for PD-L1(PDCD1 LG1)and PD-L1(SP142)was 0.385(95%CI:0.304–0.466),that for PD-L1(PDCD1 LG1)and PD-L1(PCR)was 0.207(95%CI:0.127–0.287),and that for PD-L1(SP142)and PD-L1(PCR)was 0.389(95%CI:0.309–0.469).CONCLUSION Thus,all three markers of PD-L1 expression are associated with the characteristics of aggressive BC,demonstrating moderate concordance between the tests.
文摘(2E,6E)-4-methyl-2,6-bis(pyridin-3-ylmethylene)cyclohexan-1-one(L_(1))and 4-methyl-2,6-bis[(E)-4-(pyridin-4-yl)benzylidene]cyclohexan-1-one(L_(2))were synthesized and combined with isophthalic acid(H_(2)IP),then under solvothermal conditions,to react with transition metals achieving four novel metal-organic frameworks(MOFs):[Zn(IP)(L_(1))]_(n)(1),{[Cd(IP)(L_(1))]·H_(2)O}_(n)(2),{[Co(IP)(L_(1))]·H_(2)O}_(n)(3),and[Zn(IP)(L_(2))(H_(2)O)]_(n)(4).MOFs 1-4 have been characterized by single-crystal X-ray diffraction,powder X-ray diffraction,thermogravimetry,and elemental analysis.Single-crystal X-ray diffraction shows that MOF 1 crystallizes in the monoclinic crystal system with space group P2_(1)/n,and MOFs 2-4 belong to the triclinic system with the P1 space group.1-3 are 2D sheet structures,2 and 3 have similar structural characters,whereas 4 is a 1D chain structure.Furthermore,1-3 exhibited certain photocatalytic capability in the degradation of rhodamine B(Rh B)and pararosaniline hydrochloride(PH).4could be used as a heterogeneous catalyst for the Knoevenagel reaction starting with benzaldehyde derivative and malononitrile.4 could promote the reaction to achieve corresponding products in moderate yields within 3 h.Moreover,the catalyst exhibited recyclability for up to three cycles without significantly dropping its activity.A mechanism for MOF 4 catalyzed Knoevenagel condensation reaction of aromatic aldehyde and malononitrile has been initially proposed.CCDC:2356488,1;2356497,2;2356499,3;2356498,4.
基金supported by MEXT KAKENHI Grant(24K01295,26286013).
文摘Traditional p-type colloidal quantum dot(CQD)hole transport layers(HTLs)used in CQD solar cells(CQDSCs)are commonly based on organic ligands exchange and the layer-by-layer(LbL)technique.Nonetheless,the ligand detachment and complex fabrication process introduce surface defects,compromising device stability and efficiency.In this work,we propose a solution-phase ligand exchange(SPLE)method utilizing inorganic ligands to develop stable p-type lead sulfide(PbS)CQD inks for the first time.Various amounts of tin(Ⅱ)iodide(SnI_(2))were mixed with lead halide(PbX_(2);X=I,Br)in the ligand solution.By precisely controlling the SnI_(2)concentration,we regulate the transition of PbS QDs from n-type to p-type.PbS CQDSCs were fabricated using two different HTL approaches:one with 1,2-ethanedithiol(EDT)-passivated QDs via the LbL method(control)and another with inorganic ligand-passivated QD ink(target).The target devices achieved a higher power conversion efficiency(PCE)of 10.93%,compared to 9.83%for the control devices.This improvement is attributed to reduced interfacial defects and enhanced carrier mobility.The proposed technique offers an efficient pathway for producing stable p-type PbS CQD inks using inorganic ligands,paving the way for high-performance and flexible CQD-based optoelectronic devices.
文摘Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as vip molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions.
文摘To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2.
基金financial support from the National Key Research and Development Program of China(No.2021YFF0600704).
文摘The hydroformylation of olefins,known as the"oxo reaction",involves the use of syngas(CO/H_(2))to produce aldehyde with an additional carbon atom.However,side reactions such as the isomerization or hydrogenation of olefins often result in unexpected products and other by-products.Recent efforts in developing efficient ligands represent the most effective approach to addressing these challenges.In this study,we described a Bis-OPNN phosphorus ligand facilitated Rh-catalyzed hydroformylation with a high degree of linear selectivity across various olefins.Under mild conditions,a broad range of olefins were efficiently converted into linear aldehydes with high yields and excellent regioselectivity.The protocol also showed impressive functional group tolerance and was successfully applied to modify drugs and natural products,including the total synthesis of(±)-crispine A.Preliminary mechanistic studies revealed that this Bis-OPNN phosphorus ligand anchoring the rhodium catalyst is crucial for controlling the linear selectivity.
基金supported by the National Natural Science Foundation of China(Nos.52170156,52250056,and 52293443)the Shenzhen Science and Technology Program(No.KQTD20190929172630447).
文摘Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.
基金supported by the National Natural Science Foundation of China(Nos.52300120 and 52070144)the Fundamental Research Funds for the Central Universities(No.22120240465).
文摘Regulating the photo-response region of iron metal-organic frameworks(Fe-MOFs)is a viable strategy for enhancing their practical application in the visible-light driven photo-Fenton-like process.This study developed a novel pyrazine-based Fe-MOFs(MIL-101(Fe)-Pz)by substituting the 1,4-dicarboxybenzene acid ligands in typical MIL-101(Fe)with 2,5-pyrazinedicarboxylic acid(PzDC),in which sodium acetate was used as coordinative modulator to control the crystal size(2–3μm).The incorporation of Fe-pyridine N coordination structures originated from PzDC ligands gave MIL-101(Fe)-Pz narrowed band gap(1.45 eV)than MIL-101(Fe)(2.54 eV)resulting in improved visible-light adsorption capacity(λ>420 nm),and also increased the proportion of Fe(Ⅱ)in the Fe-clusters.Thus MIL-101(Fe)-Pz exhibited a synergistic enhanced photo-Fenton-like catalytic performance under visible-light irradiation.The MIL-101(Fe)-Pz/H_(2)O_(2)/Vis system could degrade 99%of sulfamethoxazolewithin 30min,whichwas 10-fold faster than that of the pristine MIL-101(Fe),it also effectively removed other organic micropollutants with high durability and stability.Mechanistic analysis revealed that the PzDC ligands substitution decreased the band gap of MIL-101(Fe),giving MIL-101(Fe)-Pz appropriate band structure(-0.40∼1.05 V vs.NHE)which can cover several light-driven process for the generation of reactive oxygen species,including Fe(Ⅲ)reduction and H_(2)O_(2) activation for accelerating•OH generation,as well as oxygen reduction reaction for generating H_(2)O_(2),O_(2)^(•−) and ^(1)O_(2).This study highlights the role of pyridine-N containing ligands in regulating the band structure of Fe-MOFs,providing valuable guidance for the design of Fe-MOFs photocatalysts.
基金the National Key R&D Program of China(No.2022YFB4101900)National Natural Science Foundation of China(Nos.22278305,U21B2096)Natural Science Foundation of Tianjin City(No.23JCZDJC00040)。
文摘A strategy for copper-catalyzed and biphosphine ligand controlled boracarboxylation of 1,3-dienes and CO_(2) with 3,4-selectivity was developed.The Cu Cl coupled with DPPF(1,1-bis(diphenylphosphino)ferrocene)was assigned to be the best catalyst,with 84%yield and exclusive3,4-selectivity.The ligand effect on both catalytic activity and regioselectivity of boracarboxylation was disclosed,which is rarely reported in any copper catalyzed boracarboxylation.The borocupration process is revealed to be a vital step for the biphosphine participated boracarboxylation of 1,3-dienes with CO_(2).The minimal substrate distortion occurring in 3,4-borocupration favors the 3,4-regioselectivity of boracarboxylation.The“pocket”confinement and suitableβ_(n)(92°–106°)of bisphosphine ligands are demonstrated to be in favour of the interaction between LCu-Bpin complex(the catalytic precursor)and1,3-diene substrate to decrease their interaction energyΔE_(int)(ζ)in 3,4-borocupration,thus promoting the 3,4-boracarboxylation.
基金support from the National Key Research and Development Program of China(2022YFE0206000)the National Natural Science Foundation of China(U2001219,51973064)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2023B1515040003,2024A1515010262)the Natural Science Foundation of Guangdong Province(2023B1212060003)the Open Project Program of Wuhan National Laboratory for Optoelectronics(NO.2021WNLOKF014)the State Key Lab of Luminescent Materials and Devices,South China University of Technology(Skllmd-2023-05).
文摘Formamidinium lead bromide(FAPbBr_(3))perovskite nanocrystals(NCs)are promising for display and lighting due to their ultra-pure green emission.However,the thermal quenching will exacerbate their performance degradation in practical applications,which is a common issue for halide perovskites.Here,we reported the heat-resistant FAPbBr_(3)NCs prepared by a ligand-engineered room-temperature synthesis strategy.An aromatic amine,specificallyβ-phenylethylamine(PEA)or 3-fluorophenylethylamine(3-F-PEA),was incoporated as the short-chain ligand to expedite the crystallization rate and control the size distribution of FAPbBr_(3)NCs.Employing this ligand engineering approach,we synthesized high quality FAPbBr_(3)NCs with uniform grain size and reduced long-chain alkyl ligands,resulting in substantially suppressed thermal quenching and enhanced carrier transportation in the perovskite NCs films.Most notably,more than 90%of the room temperature PL intensity in the 3-F-PEA modified FAPbBr_(3)NCs film was preserved at 380 K.Consequently,we fabricated ultra-pure green EL devices with a room temperature external quantum efficiency(EQE)as high as 21.9%at the luminance of above 1,000 cd m^(-2),and demonstrated less than 10%loss in EQE at 343 K.This study introduces a novel room temperature method to synthesize efficient FAPbBr_(3)NCs with exceptional thermal stability,paving the way for advanced optoelectronic device applications.
基金supported by the National Natural Science Foundation of China(No.21975151)China Postdoctoral Science Foundation(No.2023M733452).
文摘Pt-rare-earth(PtRE)alloys are considered to be highly promising catalysts for oxygen reduction reaction(ORR)in acidic electrolytes.However,the wet-chemical synthesis of PtRE nanoalloys still faces significant challenges.The precise reaction mechanism for ORR of these catalysts is still unclear on significant aspects involving the rate-determining step and the nature of the ligand effect.Herein,we report a class of solvothermal synthesis of PtRE(RE is Dy or La)nanoalloys.Such PtRE nanoalloys here are active and stable in acidic media,with both high mass activities enhanced by 2-5 times relative to commercial Pt/C catalyst and high stabilities indicative of the little activity decay and negligible structure change after 10,000 cycles.Density functional theory calculations firmly confirm that the ligand effect of RE elements accelerates an O-O bond scission and steers the rate-determining steps from OH^(*)+H^(+)+e-→H_(2)O(on pure Pt surface)to HOOH^(*)+H^(+)+e-→OH^(*)+H_(2)O(on the PtRE nanoalloy surface)for the fast reaction kinetics,which could be fine-tuned by regulating the RE electronic structures and consequently endows the maximal rate of ORR catalysis with PtDy alloy catalysts.
文摘BACKGROUND In recent years,emerging clinical research has prioritized assessment of combined therapeutic efficacy and safety parameters when programmed death 1 or its ligand(PD-1/L1)inhibitors are incorporated into first-line standard-of-care(SOC)therapy for metastatic colorectal cancer(mCRC).However,data obtained from these trials demonstrated conflicting evidence concerning survival benefits and clinical outcomes.AIM To evaluate the therapeutic impact and safety parameters of combining PD-1/L1 inhibitors with SOC protocols as first-line treatment for mCRC.METHODS Four biomedical databases(PubMed,Embase,Cochrane Library,Web of Science)were systematically interrogated to identify eligible studies published up to October 12,2024.The analysis focused on evaluating the primary outcome of overall survival(OS)in the mCRC population with secondary outcomes of progression-free survival(PFS),overall response rate(ORR),and incidence rate of grade≥3 adverse events.Additionally,we performed exploratory analyses in the microsatellite stable/mismatch repair-proficient(MSS/pMMR)subpopulation,based on a subset of the included studies.Subgroup analyses according to PD-1/L1 inhibitor use were conducted in both the overall population and the MSS/pMMR subgroup.RESULTS This pooled analysis incorporated six randomized controlled trials involving 675 patients with mCRC receiving first-line therapy.The combination of PD-1/L1 inhibitors with SOC regimens demonstrated a significant PFS advantage over SOC monotherapy in intention-to-treat populations[hazard ratio(HR)=0.8,95%confidence interval(CI):0.65-0.98,P=0.033].Nevertheless,the MSS/pMMR subgroup showed no PFS benefit(HR=0.83,95%CI:0.67-1.03,P=0.091),and no cohort exhibited OS improvement(intention-to-treat:HR=0.84,95%CI:0.66-1.05,P=0.124;MSS/pMMR:HR=0.79,95%CI:0.60-1.03,P=0.083).Comparable outcomes were observed for ORR(risk ratio=1.03,95%CI:0.90-1.17,P=0.711)and incidence rate of grade≥3 adverse events(risk ratio=1.12,95%CI:0.93-1.36,P=0.245)between treatment arms.CONCLUSION The findings indicated that integrating PD-1/L1 blocking agents with SOC regimens for mCRC as first-line treatment failed to demonstrate significant improvements in ORR.Existing clinical data remain inadequate to establish OS advantages,particularly in patients with MSS/pMMR,despite exhibiting manageable toxicity profiles.Subsequent confirmation through rigorously designed phase III clinical trials remains essential to verify these therapeutic outcomes.
基金supported by the Natural Science Foundation of Hunan Province(No.2023JJ30650)the Central South University Innovation-Driven Research Programme(No.2023CXQD061)。
文摘The atomic-level exploration of structure-property correlations poses significant challenges in establishing precise design principles for electrocatalysts targeting efficient CO_(2)conversion.This study demonstrates how controlled exposure of metal sites governs CO_(2)electroreduction performance through two octanuclear bismuth-oxo clusters with distinct architectures.The Bi_(8)-DMF cluster,constructed using tert–butylthiacalix[4]arene(TC4A)as the sole ligand,features two surface-exposed Bi active sites,while the dual-ligand Bi_(8)-Fc(with TC4A/ferrocene carboxylate)forms a fully encapsulated structure.Electrocatalytic tests reveal Bi_(8)-DMF achieves exceptional formate selectivity(>90%Faradaic efficiency)across a broad potential window(-0.9 V to-1.6 V vs.RHE)with 20 h stability,outperforming Bi_(8)-Fc(60%efficiency at-1.5 V).Theoretical calculations attribute Bi_(8)-DMF's superiority to exposed Bi sites that stabilize the critical*OCHO intermediate via optimized orbital interactions.This work provides crucial guidance for polynuclear catalyst design:moderate exposure of metal active sites significantly enhances CO_(2)reduction performance.
基金supported by the National Key R&D Program of China(2022YFB4200500)the Key Research and Development Plan Project of Anhui Province(2022h11020014)+3 种基金Collaborative Innovation Program of Hefei Science Center,CAS(2022HSCCIP006)the CASHIPS Director’s Fund(YZJJ201902 and YZJJZX202018)the Anhui Provincial Natural Science Foundation(2408085MB029)the Natural Science Foundation of Hebei Province of China(B2024402018)。
文摘Perovskite solar cells(PSCs)are promising in the field of photovoltaics but are hindered by surface defects and stability.However,the energetic losses occurring at the interfaces between the perovskite and the charge transport layers often lead to reduced power conversion efficiency(PCE).Surface treatment is an effective strategy but the passivating ligands usually bind with a single active site.The resulted dense packing of resistive passivators perpendicular to the surface is detrimental to charge transport.Here,we present a passivator that can bind to two neighboring lead(Ⅱ)ion(Pb^(2+))defect sites simultaneously with an aligned parallel mode to the perovskite surface,effectively suppressing the surface trap density and preventing the aggregation.The target device fulfills a PCE of 25.1%and maintains over 85% of the initial efficiency after 800 h of exposure to a relative humidity(RH)of 65%±5%.
基金support from the National Natural Science Foundation of China(Grant No.22102140the Natural Science Foundation of Jiangsu Province(Grant No.BK20211602)+1 种基金the Qing Lan Project of Yangzhou Universitythe Postgraduate Research&Practice Innovation Program of Jiangsu Province(Yangzhou University,Grant No.SJCX23_1911).
文摘Electrocatalytic valorization of disused poly(ethylene terephthalate)(PET)plastics into value-added chemicals emerges as a potential approach to address plastic pollution and resources upgrading,but it faces challenges in the development of efficient catalysts for PET-derived ethylene glycol(EG)electrooxidation.Herein,we proposed pyramid arrays on sheet Fe-doped NiO/FeNi_(3)(SPA-NiFeO_(x)/FeNi_(3))heterostructure,which is derived from the pyrolysis of MOF-on-MOF heterostructure growth triggered by graphene quantum dots(GQDs).Such SPA-NiFeO_(x)/FeNi_(3)exhibits superior catalytic performance on the electrooxidation of EG(EGOR)from PET hydrolysate,with a formic acid(FA)selectivity of 91.5%and a Faradaic efficiency of 92%.The ligand effect of GQDs in both the catalyst design and improved electrocatalytic performance was studied with combined spectroscopy analysis and theoretical calculations,which revealed that such spatially separated NiFeO_(x)and FeNi_(3)components by GQDs possess more active sites to anticipate in electrocatalytic EGOR,and the large sp2 domains in GQDs possess a strong electron-withdrawing ability to reduce the electron density of bonded Ni and Fe,resulting in high-valenced Ni^(δ+)/Fe^(δ+)in FeNi_(3)and Ni(2+δ)in NiO,respectively.Furthermore,the coordination number of Ni and Fe centers was lowered due to the steric effect of GQDs.Therefore,the adsorption of EG on Ni^(δ+)for cascade dehydrogenation and C–C bond cleavage led to adsorbed FA that transferred to adjacent Fe for desorption,which was promoted by the enrichment of OH−on nearby Ni^((2+δ))sites,along with optimized Gibbs free energy change in the multistep reaction pathway.This work provides an efficient multi-active-site catalyst for disused PET plastics valorization,thereby presenting a new approach to enhance the efficiency of PET plastics valorization reactions.
基金financially supported by the Natural Science Foundation of Guangxi,China(Nos.2019GXNSFGA245003 and 2021GXNSFBA220058)the National Natural Science Foundation of China(Nos.22272036 and 22362008)+2 种基金Guangxi Technology Base and Talent Subject,China(GUIKE AD23026272)Guangxi Normal University Research Grant,China(No.2022TD)Innovation Project of Guangxi Graduate Education(No.XYCSR2023018)。
文摘Metal nanoclusters(MNCs)possess distinct chemical properties due to their diverse electronic structures.As a class of promising model catalysts,it is of importance to explore the relationship between their structures and properties.However,it is still challenging to get highly active and stable MNCs as surface ligands can hinder their activities,while a complete lack of surface ligand protection can lead to instability.To address this concern,here a series of Pd_(6)nanoclusters(NCs)with varying ligand amounts were synthesized by using Pd_(6)(SC_(6)(C_(2))H_(17))_(12)as precursor and single-walled carbon nanotube(s-CNT)as carrier through treating the composite at different temperatures and times.
文摘An efficient and novel approach is proposed for oxidative arylation of bio-based furfuryl alcohol(FA)to aryl furans(AFs),a versatile monomer of photoelectric materials,in the presence of UiO-67-Pd(F)with phenanthroline/bipyridine,and poly-F substituted phenyl ligands as the mixture linkers.The results of control experiments and theoretical calculations reveal that the–F on the phenyl linkers efficiently tunes the electron-deficient nature of Pd through the Zr_(6) clusters bridges,which favors the adsorption and activation of the furan ring.Furthermore,the conjugation of different nitrogen-containing ligands facilitates Pd coordination for the Heck-type insertion and subsequent electrophilic palladation,respectively.As a result,the oxidative arylation of FA derivatives is substantially enhanced because of these electronic and steric synergistic effects.Under the optimized conditions,72.2%FA conversion and 74.8%mono aryl furan(MAF)selectivity are shown in the Heck-type insertion.Meanwhile,85.3%of MAF is converted,affording 74.8%selectivity of final product(AFs)in the subsequent electrophilic palladation reaction.This process efficiency is remarkably higher than that with homogeneous catalysts.In addition,furan-benzene polymer obtained from the halogen-free synthesis catalyzed by UiO-67-Pd(F)show significantly better properties than that from conventional Suzuki coupling method.Therefore,the present work provides a new insight for useful AFs synthesis by oxidative arylation of bio-furan via rational tunning the metal center micro-environment of heterogeneous catalyst.
基金Supported by the National Natural Science Foundation of China,No.82160192and Guangxi Science and Technology Program,No.2023AB23037.
文摘BACKGROUND In vivo degradation of bone scaffolds is significantly influenced by osteoclast(OC)activity,which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand(RANKL)and osteoprotegerin(OPG).The ratio of RANKL/OPG is a crucial determinant of OC-mediated bone resorption,which plays an integral role in bone remodeling and scaffold degradation.Elevated levels of RANKL relative to OPG enhance osteoclastogenesis,thereby accelerating the degradation process essential for integrating bone scaffolds into the host tissue.AIM To elucidate the effects of OPG gene silencing on osteoclastogenesis within rat bone marrow-derived mesenchymal stem cells(BMSCs).By investigating these effects,the study aimed to provide deeper insights into the regulatory mechanisms that influence bone scaffold degradation,potentially leading to improved bone repair and regeneration strategies.METHODS We employed recombinant lentiviral plasmids to silence the OPG gene in rat BMSCs to achieve the aims.The efficacy of gene silencing was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis to measure the expression levels of OPG and RANKL.Tartrate-resistant acid phosphatase staining was utilized to evaluate the formation of OCs.Additionally,co-immunoprecipitation assays were conducted to explore the interactions between RANKL and OPG proteins,further assessing the biochemical pathways involved in osteoclastogenesis.RESULTS The silencing of the OPG gene in BMSCs resulted in a significant increase in the RANKL/OPG ratio,evidenced by decreased expression levels of OPG and increased levels of RANKL.Enhanced osteoclastogenesis was observed through tartrate-resistant acid phosphatase staining,which indicated a substantial rise in OC formation in response to the altered RANKL/OPG balance.The co-immunoprecipitation assays provided concrete evidence of the direct interaction between RANKL and OPG proteins,substantiating their pivotal roles in regulating OC activity.CONCLUSION The findings from this study underscore the critical role of the RANKL/OPG axis in osteoclastogenesis.Silencing of the OPG gene in BMSCs effectively increases the RANKL/OPG ratio,promoting OC activity and potentially enhancing bone scaffold degradation.This regulatory mechanism offers a promising avenue for modulating bone remodeling processes,which is essential for effective bone repair and the successful integration of bone scaffolds into damaged sites.Future research might focus on optimizing the control of this axis to better facilitate bone tissue engineering and regenerative therapies.
