Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct...Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.展开更多
Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2...Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.展开更多
As an important class of phenanthroline derivatives containing soft N and hard O donor atoms,the laborious syntheses of unsymmetrical 1,10-phenanthroline-derived diamide ligands(DAPhen) have hindered its extensive stu...As an important class of phenanthroline derivatives containing soft N and hard O donor atoms,the laborious syntheses of unsymmetrical 1,10-phenanthroline-derived diamide ligands(DAPhen) have hindered its extensive study.In this work,we first report a convenient synthetic method for the construction of DAPhen using Friedländer reaction by two facile steps(vs.previous 12 steps).A variety of DAPhen ligands are readily available,especially unsymmetrical ones,which give us a platform to systematically study the substituent effect on f-block elements extraction performance.The performance of unsymmetrical extractants is experimentally confirmed to falls between that of their corresponding symmetrical extractants by extracting UO_(2)^(2+) as the representative f-block element.This work provides a direct and versatile method to synthesize symmetrical and unsymmetrical DAPhen,which paves way for the investigations on their coordination properties with metal ions and other applications.展开更多
The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron...The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron shell occupancy presents significant experimental challenges.Here,we introduce a ligation strategy that circumvents these limitations by demonstrating that the adiabatic electron affinity(AEA) of aluminum-based clusters,whether with filled or partially filled electron shells,can be dramatically enhanced through the attachment of organic Lewis acid ligands.It was evidenced that the AEA of PAl12can be significantly increased by 2.17 e V after the ligation of two ligands,indicating a remarkable improvement in its electron-accepting ability.This approach yields superhalogen species,offering a versatile and practical means to tune the electronic properties of clusters while preserving their superatomic states,independent of shell occupancy.Remarkably,this ligand-induced modulation is not confined to naked clusters but also extends to nano-confined systems,hinting at its broader applicability.Given the indispensable role of ligands in cluster synthesis,this strategy holds promise for advancing the field of condensed-phase superatom synthesis,potentially complementing traditional electron-counting rules in a broader range of applications.展开更多
Rational design of nanozymes with enhanced catalytic efficiency remains a central challenge in the development of artificial enzymes.Herein,we report the construction of ultrasmall gold nanoclusterbased nanoassemblies...Rational design of nanozymes with enhanced catalytic efficiency remains a central challenge in the development of artificial enzymes.Herein,we report the construction of ultrasmall gold nanoclusterbased nanoassemblies(Dp-Au NCs@Fe^(2+)) through the coordination of Fe^(2+) ions by a dopa-containing peptidomimetic ligand(Dp CDp).This nanoarchitecture simultaneously integrates catalytically active gold cores and redox-active Fe^(2+)centers,bridged by Dp CDp to facilitate directional electron transfer.Comprehensive spectroscopic and kinetic analyses reveal that Dp CDp promotes efficient charge migration from the Au core to surface-bound Fe^(2+),significantly enhancing H_(2)O_(2)-mediated peroxidase-like activity.Compared to bare Dp-Au NCs,Dp-Au NCs@Fe^(2+) display a 4.3-fold improvement in detection sensitivity,a 6.7-fold increase in catalytic efficiency,and markedly stronger hydroxyl radical generation.Mechanistically,this activity stems from a synergistic triad:direct H_(2)O_(2) oxidation at gold surfaces,radical generation at Fe^(2+) sites,and Dp CDp-facilitated electron shuttling.This work presents a robust strategy for nanozyme enhancement via electronic and structural co-engineering,offering valuable insights for the future design of bioinspired catalytic systems.展开更多
BACKGROUND Recent studies have indicated that an antibody against programmed cell death protein 1-ligand 1(PDCD1-LG1),a new marker of programmed cell death-ligand 1 expression,is promising for studying the mechanisms ...BACKGROUND Recent studies have indicated that an antibody against programmed cell death protein 1-ligand 1(PDCD1-LG1),a new marker of programmed cell death-ligand 1 expression,is promising for studying the mechanisms of breast cancer(BC)progression and resistance to chemotherapy.AIM To compare the features of PDCD1-LG1 expression in chemoresistant luminal A BC and BC with high Ki67 indices.METHODS This prospective single-center observational cohort study included 148 patients with newly diagnosed primary resectable BC.The tumor sections were stained with antibodies against PDCD1-LG1.The statistical calculations were performed using Statistica software version 12.0.P<0.05 was considered statistically significant.RESULTS Cytoplasmic PDCD1-LG1(cPDCD1-LG1)expression was detected in the nonneoplastic epithelium,tumor cells(TCs)and immune cells(ICs).A lack of cPDCD1-LG1 expression in≥20% of TCs and a PDCD1-LG1+IC score≥10%were associated with aggressive BC characteristics,including tumor G3,estrogen receptor-negative status,overexpression of human epidermal growth factor receptor 2(HER2+),luminal B HER2+BC,nonluminal HER2+BC and triplenegative BC.The lack of cPDCD1-LG1 expression in<20% of the TCs,in combination with a PDCD1-LG1+IC score<10% and G1,was characteristic of chemoresistant luminal A BC,whereas the lack of cPDCD1-LG1 expression in≥20% of the TCs,combined with a PDCD1-LG1+IC score≥10%,was a predictor of high BC sensitivity to chemotherapy.CONCLUSION These results indicate that both the lack of cPDCD1 LG1 in TCs and the PDCD1 LG1 IC score and their combination may be important for assessing BC prognosis and sensitivity to chemotherapy.展开更多
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
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
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 The diagnosis of inflammatory bowel disease(IBD)involves clinical,endoscopic,and radiologic evaluation.Endoscopic procedures,particularly in pediatrics,require general anesthesia and carry potential risks.A...BACKGROUND The diagnosis of inflammatory bowel disease(IBD)involves clinical,endoscopic,and radiologic evaluation.Endoscopic procedures,particularly in pediatrics,require general anesthesia and carry potential risks.AIM To investigate whether serum biomarkers can differentiate between pediatric patients with and without IBD.Secondary objectives included identifying biomarkers that distinguish Crohn’s disease(CD)from ulcerative colitis(UC)and assessing their predictive value for progression to biologic therapy.METHODS Pediatric patients undergoing diagnostic colonoscopy at British Columbia Children’s Hospital between December 2017 and June 2022 were enrolled.Blood samples were collected at colonoscopy,and demographic clinical data,laboratory,and histopathologic evaluation were obtained.An exploratory screen of 50 biomarkers was undertaken in a subset of patients(54 IBD,41 controls)using LegendplexTM flow cytometry kits to identify candidates.A refined panel of 12 serum biomarkers was subsequently selected and a supervised learning model was developed to classify patients.RESULTS The study included 246 pediatric patients,who had a median age of 13.03 years and were 37.4%female(103 CD,52 UC,91 controls).In univariate analyses,C-X-C motif chemokine ligand 9(CXCL9)was the only biomarker significantly elevated in IBD vs controls(P<0.001).A multivariable model achieved an area under the receiver operating characteristic of 0.861 for distinguishing IBD from controls.Interleukin 8(IL-8)emerged as a key biomarker alongside CXCL9 and IL-22 in the model.The random forest model identified CXCL9 with the greatest diagnostic accuracy(area under the curve[AUC]=0.81),followed by IL8 and IL22(AUC=0.737 and 0.68,respectively).CXCL9 and IL-18 showed higher levels in CD(P=0.016),whereas CXCL1 levels predicted progression to biologic therapy within 1 year(P=0.039).However,the model did not effectively predict disease subclassification or progression to biologic therapy.CONCLUSION Serum biomarkers,particularly CXCL9,IL-8,and IL-22,can aid in the diagnosis of pediatric IBD.CXCL9 and IL18 were found to be significant predictors of CD,and CXCL1 differed between patients requiring biologic therapy vs those who did not.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
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
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
Objectives:Targeting epigenetic modifications in anticancer therapy is a promising approach to overcoming cancer cell chemoresistance.The histone deacetylase/DNA methyltransferase inhibitor,parthenolide(PTL),has antit...Objectives:Targeting epigenetic modifications in anticancer therapy is a promising approach to overcoming cancer cell chemoresistance.The histone deacetylase/DNA methyltransferase inhibitor,parthenolide(PTL),has antitumor activity,but contrasting findings exist on its effect in normal cells.This study aims to examine the nongenomic toxic mechanisms of PTL in human erythrocytes.Methods:Cell death as stimulated by 20–200μMof PTL for 24 h at 37℃ was assessed using fluorescence-assorted cell sorting and spectrophotometric assays.Canonical markers of cell death,including membrane scrambling,oxidative stress,and Ca^(2+)mobilization,were captured by annexin V-fluorescein isothiocyanate,2′,7′-dichlorodihydrofluorescein diacetate,and Fluo4/AM labeling,respectively.Rescue experiments usingawide arrayof inhibitorswere also conducted.Results:PTL stimulated significantmembrane scrambling and blebbing,and showed potent hemolytic activity coupled with significant elevations in dichlorofluorescein and Fluo4 fluorescence.While hemolysis was ameliorated by glutathione,caffeine,acetylsalicylic acid,staurosporin,necrosulfonamide,guanosine,and Ca^(2+)deprivation,it was rather exacerbated by necrostatin-2,tumor necrosis factor α(TNFα)or Fas ligand(FasL)neutralization,and concurrent Ca^(2+)deprivation and membrane depolarization.In contrast,eryptosis was attenuated by N-acetyl-cysteine,TNFα,or FasL blockade,and simultaneous Ca^(2+)elimination and KCl enrichment;and augmented by necrostatin-2,necrosulfonamide,and adenosine triphosphate.Interestingly,loss of volume was only prevented by melatonin,acetylsalicylic acid,and N(gamma)-nitro-L-arginine methyl ester.Conclusion:PTL stimulates oxidative hemolysis and eryptosis through Ca^(2+)mobilization and death ligand signaling involving the cyclooxygenase/protein kinase C/mixed lineage kinase domain-like pseudokinase axis.This research highlights the non-genomic toxic mechanisms of PTL and presents potential pharmacological targets for mitigating its adverse off-target effects.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
It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO...It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO_(2))_(cluster)/Fe,Mn-N-C with Fe-N_(4)O_(1) site coupled by MnO_(2) sub-nanometer clusters was successfully synthesized,which is attributed to the dicyanodiamine-glycine(DCD-Gly)dual-ligand effect.Specifically,the higher electrophilic index and the preferential coordination with Fe of N in DCD,and the chelating coordination of Gly with Mn.Experimental and theoretical calculation results indicate that preferential coordination of Fe with N atoms in DCD generates Fe-N_(4)O_(1) sites with axial oxygen coordination,while the coordination of Mn with Gly generates a large number of MnO_(2) sub-nanometer clusters.DFT calculations showed that axial oxygen altered the reaction-determining step of ORR at the FeN_(4)O_(1) site.Meanwhile,the MnO_(2) sub-nanoclusters further lowered the adsorption energy barriers of the reaction intermediates.This synergistic charge-regulation improved the ORR performance of(MnO_(2))_(cluster)/Fe,Mn-N-C(E_(1/2)=0.90 V).Meanwhile,(MnO_(2))_(cluster/)Fe,Mn-N-C catalyst also exhibits a discharge power density of 201 mW cm~(-2)in Zn-air batteries,which was much higher than the commercial Pt/C+RuO_(2).The strategy of ligand effect-driven construction provided a new idea for the electronic structure modulation of a monatomic catalyst.展开更多
文摘Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
文摘Four distinct coordination polymers(CPs)were successfully synthesized by altering solvent types and adjusting ligand concentrations,and their crystal structures were investigated.[Co(L)(FDCA)(H_(2)O)_(2)]·0.5H_(2)O(1)was synthesized as a 2D structure using Coas the metal source,methanol‑water(4∶6,V/V)as the solvent,and specific concentrations of 2,5‑furandicarboxylic acid(H_(2)FDCA)and 1,3,5‑triimidazole benzene(L).Adjusting to pure water and lowering the concentration of L yielded the 1D chain structure of[Co(HL)2(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(2).Using Cu(Ⅱ)as the metal source,methanol/water(9∶1,V/V)as the solvent,and specific concentrations of L and H2FDCA,the 1D chain structure of[Cu(L)(FDCA)(H_(2)O)]·2H_(2)O(3)was synthesized.Upon increasing the concentrations of L and H2FDCA,and switching the solvent to pure water,the 1D chain structure of[Cu(HL)_(2)(H_(2)O)_(2)](FDCA)_(2)·6H_(2)O(4)was obtained.This shows that changing the solvent and ligand concentrations can affect the structural changes of CPs.In addition,the solid‑state photoluminescence of CPs 1‑4 at room temperature was studied,and their morphological changes were observed via scanning electron microscopy.Density functional theory calculations revealed that the negative charge concentrates on the O and N atoms of the ligand,facilitating ligand‑metal ion coordination.CCDC:2403934,1;2403935,2;2403936,3;2403938,4.
基金financial support from the National Natural Science Foundation of China (Nos.22476178,U2067213)Natural Science Foundation of Zhejiang Province (No.LRG25B060002)。
文摘As an important class of phenanthroline derivatives containing soft N and hard O donor atoms,the laborious syntheses of unsymmetrical 1,10-phenanthroline-derived diamide ligands(DAPhen) have hindered its extensive study.In this work,we first report a convenient synthetic method for the construction of DAPhen using Friedländer reaction by two facile steps(vs.previous 12 steps).A variety of DAPhen ligands are readily available,especially unsymmetrical ones,which give us a platform to systematically study the substituent effect on f-block elements extraction performance.The performance of unsymmetrical extractants is experimentally confirmed to falls between that of their corresponding symmetrical extractants by extracting UO_(2)^(2+) as the representative f-block element.This work provides a direct and versatile method to synthesize symmetrical and unsymmetrical DAPhen,which paves way for the investigations on their coordination properties with metal ions and other applications.
基金supported by the National Natural Science Foundation of China (NSFC,Nos.12474274,92161101)the Innovation Project of Jinan Science and Technology Bureau (No.2021GXRC032)the Natural Science Foundation of Shandong Province (No.ZR2024MA091)。
文摘The Jellium closed-shell model,a cornerstone of cluster science,has long guided the design of superatoms by dictating electron-counting rules.However,its reliance on precise control of cluster composition and electron shell occupancy presents significant experimental challenges.Here,we introduce a ligation strategy that circumvents these limitations by demonstrating that the adiabatic electron affinity(AEA) of aluminum-based clusters,whether with filled or partially filled electron shells,can be dramatically enhanced through the attachment of organic Lewis acid ligands.It was evidenced that the AEA of PAl12can be significantly increased by 2.17 e V after the ligation of two ligands,indicating a remarkable improvement in its electron-accepting ability.This approach yields superhalogen species,offering a versatile and practical means to tune the electronic properties of clusters while preserving their superatomic states,independent of shell occupancy.Remarkably,this ligand-induced modulation is not confined to naked clusters but also extends to nano-confined systems,hinting at its broader applicability.Given the indispensable role of ligands in cluster synthesis,this strategy holds promise for advancing the field of condensed-phase superatom synthesis,potentially complementing traditional electron-counting rules in a broader range of applications.
基金supported by the National Natural Science Foundation of China (Nos.22177133,22278438)。
文摘Rational design of nanozymes with enhanced catalytic efficiency remains a central challenge in the development of artificial enzymes.Herein,we report the construction of ultrasmall gold nanoclusterbased nanoassemblies(Dp-Au NCs@Fe^(2+)) through the coordination of Fe^(2+) ions by a dopa-containing peptidomimetic ligand(Dp CDp).This nanoarchitecture simultaneously integrates catalytically active gold cores and redox-active Fe^(2+)centers,bridged by Dp CDp to facilitate directional electron transfer.Comprehensive spectroscopic and kinetic analyses reveal that Dp CDp promotes efficient charge migration from the Au core to surface-bound Fe^(2+),significantly enhancing H_(2)O_(2)-mediated peroxidase-like activity.Compared to bare Dp-Au NCs,Dp-Au NCs@Fe^(2+) display a 4.3-fold improvement in detection sensitivity,a 6.7-fold increase in catalytic efficiency,and markedly stronger hydroxyl radical generation.Mechanistically,this activity stems from a synergistic triad:direct H_(2)O_(2) oxidation at gold surfaces,radical generation at Fe^(2+) sites,and Dp CDp-facilitated electron shuttling.This work presents a robust strategy for nanozyme enhancement via electronic and structural co-engineering,offering valuable insights for the future design of bioinspired catalytic systems.
基金Supported by the Russian Science Foundation,No.23-25-00183.
文摘BACKGROUND Recent studies have indicated that an antibody against programmed cell death protein 1-ligand 1(PDCD1-LG1),a new marker of programmed cell death-ligand 1 expression,is promising for studying the mechanisms of breast cancer(BC)progression and resistance to chemotherapy.AIM To compare the features of PDCD1-LG1 expression in chemoresistant luminal A BC and BC with high Ki67 indices.METHODS This prospective single-center observational cohort study included 148 patients with newly diagnosed primary resectable BC.The tumor sections were stained with antibodies against PDCD1-LG1.The statistical calculations were performed using Statistica software version 12.0.P<0.05 was considered statistically significant.RESULTS Cytoplasmic PDCD1-LG1(cPDCD1-LG1)expression was detected in the nonneoplastic epithelium,tumor cells(TCs)and immune cells(ICs).A lack of cPDCD1-LG1 expression in≥20% of TCs and a PDCD1-LG1+IC score≥10%were associated with aggressive BC characteristics,including tumor G3,estrogen receptor-negative status,overexpression of human epidermal growth factor receptor 2(HER2+),luminal B HER2+BC,nonluminal HER2+BC and triplenegative BC.The lack of cPDCD1-LG1 expression in<20% of the TCs,in combination with a PDCD1-LG1+IC score<10% and G1,was characteristic of chemoresistant luminal A BC,whereas the lack of cPDCD1-LG1 expression in≥20% of the TCs,combined with a PDCD1-LG1+IC score≥10%,was a predictor of high BC sensitivity to chemotherapy.CONCLUSION These results indicate that both the lack of cPDCD1 LG1 in TCs and the PDCD1 LG1 IC score and their combination may be important for assessing BC prognosis and sensitivity to chemotherapy.
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.
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 the Lutsky Family Foundation and AdMare Bioinnovations(previously known as the Genome BC CDRD Development Fund).
文摘BACKGROUND The diagnosis of inflammatory bowel disease(IBD)involves clinical,endoscopic,and radiologic evaluation.Endoscopic procedures,particularly in pediatrics,require general anesthesia and carry potential risks.AIM To investigate whether serum biomarkers can differentiate between pediatric patients with and without IBD.Secondary objectives included identifying biomarkers that distinguish Crohn’s disease(CD)from ulcerative colitis(UC)and assessing their predictive value for progression to biologic therapy.METHODS Pediatric patients undergoing diagnostic colonoscopy at British Columbia Children’s Hospital between December 2017 and June 2022 were enrolled.Blood samples were collected at colonoscopy,and demographic clinical data,laboratory,and histopathologic evaluation were obtained.An exploratory screen of 50 biomarkers was undertaken in a subset of patients(54 IBD,41 controls)using LegendplexTM flow cytometry kits to identify candidates.A refined panel of 12 serum biomarkers was subsequently selected and a supervised learning model was developed to classify patients.RESULTS The study included 246 pediatric patients,who had a median age of 13.03 years and were 37.4%female(103 CD,52 UC,91 controls).In univariate analyses,C-X-C motif chemokine ligand 9(CXCL9)was the only biomarker significantly elevated in IBD vs controls(P<0.001).A multivariable model achieved an area under the receiver operating characteristic of 0.861 for distinguishing IBD from controls.Interleukin 8(IL-8)emerged as a key biomarker alongside CXCL9 and IL-22 in the model.The random forest model identified CXCL9 with the greatest diagnostic accuracy(area under the curve[AUC]=0.81),followed by IL8 and IL22(AUC=0.737 and 0.68,respectively).CXCL9 and IL-18 showed higher levels in CD(P=0.016),whereas CXCL1 levels predicted progression to biologic therapy within 1 year(P=0.039).However,the model did not effectively predict disease subclassification or progression to biologic therapy.CONCLUSION Serum biomarkers,particularly CXCL9,IL-8,and IL-22,can aid in the diagnosis of pediatric IBD.CXCL9 and IL18 were found to be significant predictors of CD,and CXCL1 differed between patients requiring biologic therapy vs those who did not.
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 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 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funded by the Ongoing Research Funding Program at King Saud University,Riyadh,Saudi Arabia through grant number ORF-2025-554.
文摘Objectives:Targeting epigenetic modifications in anticancer therapy is a promising approach to overcoming cancer cell chemoresistance.The histone deacetylase/DNA methyltransferase inhibitor,parthenolide(PTL),has antitumor activity,but contrasting findings exist on its effect in normal cells.This study aims to examine the nongenomic toxic mechanisms of PTL in human erythrocytes.Methods:Cell death as stimulated by 20–200μMof PTL for 24 h at 37℃ was assessed using fluorescence-assorted cell sorting and spectrophotometric assays.Canonical markers of cell death,including membrane scrambling,oxidative stress,and Ca^(2+)mobilization,were captured by annexin V-fluorescein isothiocyanate,2′,7′-dichlorodihydrofluorescein diacetate,and Fluo4/AM labeling,respectively.Rescue experiments usingawide arrayof inhibitorswere also conducted.Results:PTL stimulated significantmembrane scrambling and blebbing,and showed potent hemolytic activity coupled with significant elevations in dichlorofluorescein and Fluo4 fluorescence.While hemolysis was ameliorated by glutathione,caffeine,acetylsalicylic acid,staurosporin,necrosulfonamide,guanosine,and Ca^(2+)deprivation,it was rather exacerbated by necrostatin-2,tumor necrosis factor α(TNFα)or Fas ligand(FasL)neutralization,and concurrent Ca^(2+)deprivation and membrane depolarization.In contrast,eryptosis was attenuated by N-acetyl-cysteine,TNFα,or FasL blockade,and simultaneous Ca^(2+)elimination and KCl enrichment;and augmented by necrostatin-2,necrosulfonamide,and adenosine triphosphate.Interestingly,loss of volume was only prevented by melatonin,acetylsalicylic acid,and N(gamma)-nitro-L-arginine methyl ester.Conclusion:PTL stimulates oxidative hemolysis and eryptosis through Ca^(2+)mobilization and death ligand signaling involving the cyclooxygenase/protein kinase C/mixed lineage kinase domain-like pseudokinase axis.This research highlights the non-genomic toxic mechanisms of PTL and presents potential pharmacological targets for mitigating its adverse off-target effects.
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financially supported by the Major Science and Technology Projects in Yunnan Province(202402AG050008)the Science and Technology Plan Project of Yunnan Province(202303AK140022)+1 种基金the Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML-20240502003)the Analysis and Testing Foundation of Kunming University of Science and Technology。
文摘It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO_(2))_(cluster)/Fe,Mn-N-C with Fe-N_(4)O_(1) site coupled by MnO_(2) sub-nanometer clusters was successfully synthesized,which is attributed to the dicyanodiamine-glycine(DCD-Gly)dual-ligand effect.Specifically,the higher electrophilic index and the preferential coordination with Fe of N in DCD,and the chelating coordination of Gly with Mn.Experimental and theoretical calculation results indicate that preferential coordination of Fe with N atoms in DCD generates Fe-N_(4)O_(1) sites with axial oxygen coordination,while the coordination of Mn with Gly generates a large number of MnO_(2) sub-nanometer clusters.DFT calculations showed that axial oxygen altered the reaction-determining step of ORR at the FeN_(4)O_(1) site.Meanwhile,the MnO_(2) sub-nanoclusters further lowered the adsorption energy barriers of the reaction intermediates.This synergistic charge-regulation improved the ORR performance of(MnO_(2))_(cluster)/Fe,Mn-N-C(E_(1/2)=0.90 V).Meanwhile,(MnO_(2))_(cluster/)Fe,Mn-N-C catalyst also exhibits a discharge power density of 201 mW cm~(-2)in Zn-air batteries,which was much higher than the commercial Pt/C+RuO_(2).The strategy of ligand effect-driven construction provided a new idea for the electronic structure modulation of a monatomic catalyst.
