Publications by authors named "Zekai Lin"

The tumor microenvironment is increasingly acknowledged as a critical contributor to cancer progression, mediating genetic and epigenetic alterations. Beyond diverse cellular interactions from the microenvironment, physicochemical factors such as tumor acidosis also significantly affect cancer dynamics. Recent research has highlighted that tumor acidosis facilitates invasion, immune escape, metastasis, and resistance to therapies.

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Incorporating phase change capsules into polymeric matrices is an effective approach for developing flexible composites with both heat storage capacity and good thermal reliability, while the interfacial heat conductance between the capsules and the matrix has seldom been considered. Herein, paraffin@SiO nanocapsules synthesized by an interfacial polycondensation process using a basic catalyst were incorporated into a polydimethylsiloxane matrix for the first time to prepare phase change composites at different loadings. Furthermore, the composites containing the nanocapsules were systematically compared with the composites containing the paraffin@SiO microcapsules synthesized using an acidic catalyst.

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Based on the SBM model including unexpected output, this paper studies the water resource utilization efficiency of 30 provinces in China from 2003 to 2019. The study found that China's water resource utilization efficiency showed obvious provincial differences. The water resource utilization efficiency of most eastern coastal provinces was relatively high, and that of most central and western inland provinces was not high.

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Article Synopsis
  • The study investigates how the Mediterranean (MED) invasive species adapts to different environmental temperatures, focusing on the role of chromatin remodeling mechanisms in developing thermal resistance.
  • Researchers identified and analyzed specific chromatin remodelers (SWI/SNF and ISWI family members) in MED and a native counterpart (Asia II 1), highlighting mutations and differences in thermal tolerance.
  • Results revealed that MED had higher expression levels of certain genes during heat stress and cold stress compared to Asia II 1, suggesting significant molecular adaptations that contribute to the invasive species' ability to thrive in varied climates.
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To reveal the mechanism of temperature preference in , one of the top 20 plant pests in the world, we cloned and identified , , and genes by RACE and bioinformatic analysis, and clarified their expression profiles during different development stages using real-time PCR, and revealed their function in preference temperature by RNAi. The full-length cDNA of was 3136 bp, with a 2865-bp open reading frame encoding a 259.89-kDa protein; and the partial length cDNA of was 2326-bp, with a 2025-bp open reading frame encoding a 193.

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We report the synthesis, characterization, and photophysical and photochemical properties of [Ru(bpy)(py)]@Zn-oxalate metal-organic framework (Ru@MOF; bpy is 2,2'-bipyridine and py is pyridine). In Ru@MOF, the cavities of the anionic Zn-oxalate MOF tightly encapsulate [Ru(bpy)(py)] complexes, thereby altering the vibrational and electronic states of [Ru(bpy)(py)] and preventing photosubstitution of py ligands. [Ru(bpy)(py)] in Ru@MOF exhibits significantly increased photoluminescence lifetime and quantum yield, likely through destabilizing the dd state and enhancing photochemical stability.

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We report the synthesis of a terpyridine-based metal-organic layer (TPY-MOL) and its metalation with CoCl and FeBr to afford CoCl·TPY-MOL and FeBr·TPY-MOL, respectively. Upon activation with NaEtBH, CoCl·TPY-MOL catalyzed benzylic C-H borylation of methylarenes whereas FeBr·TPY-MOL catalyzed intramolecular C -H amination of alkyl azides to afford pyrrolidines and piperidines. X-ray absorption near edge structure (XANES), extended X-ray absorption fine structure (EXAFS), X-ray photoelectron spectroscopy, UV-Vis-NIR spectroscopy, and electron paramagnetic spectroscopy (EPR) measurements as well as density functional theory (DFT) calculations identified M(THF)·TPY-MOL (M = Co or Fe) as the active catalyst with a M-(TPY˙˙) electronic structure featuring divalent metals and TPY diradical dianions.

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Titania (TiO) is widely used in the chemical industry as an efficacious catalyst support, benefiting from its unique strong metal-support interaction. Many proposals have been made to rationalize this effect at the macroscopic level, yet the underlying molecular mechanism is not understood due to the presence of multiple catalytic species on the TiO surface. This challenge can be addressed with metal-organic frameworks (MOFs) featuring well-defined metal oxo/hydroxo clusters for supporting single-site catalysts.

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Molecular iridium catalysts immobilized in metal-organic frameworks (MOFs) were positioned in the condensing chamber of a Soxhlet extractor for efficient CO hydrogenation. Droplets of hot water seeped through the MOF catalyst to create dynamic gas/liquid interfaces which maximize the contact of CO, H, HO, and the catalyst to achieve a high turnover frequency of 410 h under atmospheric pressure and at 85 °C. H/D kinetic isotope effect measurements and density functional theory calculations revealed concerted proton-hydride transfer in the rate-determining step of CO hydrogenation, which was difficult to unravel in homogeneous reactions due to base-catalyzed H/D exchange.

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We report the rational design of metal-organic layers (MOLs) that are built from [Hf O (OH) (HCO ) ] secondary building units (SBUs) and Ir[bpy(ppy) ] - or [Ru(bpy) ] -derived tricarboxylate ligands (Hf-BPY-Ir or Hf-BPY-Ru; bpy=2,2'-bipyridine, ppy=2-phenylpyridine) and their applications in X-ray-induced photodynamic therapy (X-PDT) of colon cancer. Heavy Hf atoms in the SBUs efficiently absorb X-rays and transfer energy to Ir[bpy(ppy) ] or [Ru(bpy) ] moieties to induce PDT by generating reactive oxygen species (ROS). The ability of X-rays to penetrate deeply into tissue and efficient ROS diffusion through ultrathin 2D MOLs (ca.

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We report the stepwise and quantitative transformation of the Zr(μ-O)(μ-OH)(HCO) nodes in Zr-BTC (MOF-808) to the [Zr(μ-O)(μ-OH)Cl] nodes in ZrCl-BTC, and then to the organometallic [Zr(μ-O)(μ-OLi)R] nodes in ZrR-BTC (R = CHSiMe or Me). Activation of ZrCl-BTC with MMAO-12 generates ZrMe-BTC, which is an efficient catalyst for ethylene polymerization. ZrMe-BTC displays unusual electronic and steric properties compared to homogeneous Zr catalysts, possesses multimetallic active sites, and produces high-molecular-weight linear polyethylene.

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We report here the synthesis of a robust and highly porous Fe-phenanthroline-based metal-organic framework (MOF) and its application in catalyzing challenging inter- and intramolecular C-H amination reactions. For the intermolecular amination reactions, a FeBr-metalated MOF selectively functionalized secondary benzylic and allylic C-H bonds. The intramolecular amination reactions utilizing organic azides as the nitrene source required the reduction of the FeBr-metalated MOF with NaBHEt to generate the active catalyst.

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Microenvironments in enzymes play crucial roles in controlling the activities and selectivities of reaction centers. Herein we report the tuning of the catalytic microenvironments of metal-organic layers (MOLs), a two-dimensional version of metal-organic frameworks (MOFs) with thickness down to a monolayer, to control product selectivities. By modifying the secondary building units (SBUs) of MOLs with monocarboxylic acids, such as gluconic acid, we changed the hydrophobicity/hydrophilicity around the active sites and fine-tuned the selectivity in photocatalytic oxidation of tetrahydrofuran (THF) to exclusively afford butyrolactone (BTL), likely a result of prolonging the residence time of reaction intermediates in the hydrophilic microenvironment of catalytic centers.

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We report here the synthesis of a robust and porous metal-organic framework (MOF), Zr-TPDC, constructed from triphenyldicarboxylic acid (HTPDC) and an unprecedented Zr secondary building unit (SBU): Zr(μ-O)(μ-OH)(μ-OH). The Zr-SBU can be viewed as an inorganic node dimerized from two commonly observed Zr clusters via six μ-OH groups. The metalation of Zr-TPDC SBUs with CoCl followed by treatment with NaBEtH afforded a highly active and reusable solid Zr-TPDC-Co catalyst for the hydrogenation of nitroarenes, nitriles, and isocyanides to corresponding amines with excellent activity and selectivity.

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The dimensionality dependency of resonance energy transfer is of great interest due to its importance in understanding energy transfer on cell membranes and in low-dimension nanostructures. Light harvesting two-dimensional metal-organic layers (2D-MOLs) and three-dimensional metal-organic frameworks (3D-MOFs) provide comparative models to study such dimensionality dependence with molecular accuracy. Here we report the construction of 2D-MOLs and 3D-MOFs from a donor ligand 4,4',4″-(benzene-1,3,5-triyl-tris(ethyne-2,1-diyl))tribenzoate (BTE) and a doped acceptor ligand 3,3',3″-nitro-4,4',4″-(benzene-1,3,5-triyl-tris(ethyne-2,1-diyl))tribenzoate (BTE-NO).

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We report the stepwise, quantitative transformation of Ce(μ-O)(μ-OH)(OH)(OH) nodes in a new Ce-BTC (BTC = trimesic acid) metal-organic framework (MOF) into the first Ce(μ-O)(μ-OLi)(H)(THF)Li metal-hydride nodes that effectively catalyze hydroboration and hydrophosphination reactions. CeH-BTC displays low steric hindrance and electron density compared to homogeneous organolanthanide catalysts, which likely accounts for the unique 1,4-regioselectivity for the hydroboration of pyridine derivatives. MOF nodes can thus be directly transformed into novel single-site solid catalysts without homogeneous counterparts for sustainable chemical synthesis.

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A series of porous twofold interpenetrated In-Co (porphyrin) metal-organic frameworks (MOFs) were constructed by in situ metalation of porphyrin bridging ligands and used as efficient cooperative catalysts for the hydration of terminal alkynes. The twofold interpenetrating structure brings adjacent Co (porphyrins) in the two networks parallel to each other with a distance of about 8.8 Å, an ideal distance for the simultaneous activation of both substrates in alkyne hydration reactions.

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We report here the synthesis of robust and porous metal-organic frameworks (MOFs), M-MTBC (M = Zr or Hf), constructed from the tetrahedral linker methane-tetrakis(p-biphenylcarboxylate) (MTBC) and two types of secondary building units (SBUs): cubic M8(μ2-O)8(μ2-OH)4 and octahedral M6(μ3-O)4(μ3-OH)4. While the M6-SBU is isostructural with the 12-connected octahedral SBUs of UiO-type MOFs, the M8-SBU is composed of eight M(IV) ions in a cubic fashion linked by eight μ2-oxo and four μ2-OH groups. The metalation of Zr-MTBC SBUs with CoCl2, followed by treatment with NaBEt3H, afforded highly active and reusable solid Zr-MTBC-CoH catalysts for the hydrogenation of alkenes, imines, carbonyls, and heterocycles.

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Earth-abundant metal catalysts are critically needed for sustainable chemical synthesis. Here we report a simple, cheap and effective strategy of producing novel earth-abundant metal catalysts at metal-organic framework (MOF) nodes for broad-scope organic transformations. The straightforward metalation of MOF secondary building units (SBUs) with cobalt and iron salts affords highly active and reusable single-site solid catalysts for a range of organic reactions, including chemoselective borylation, silylation and amination of benzylic C-H bonds, as well as hydrogenation and hydroboration of alkenes and ketones.

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Mono(phosphine)-M (M-PR3; M = Rh and Ir) complexes selectively prepared by postsynthetic metalation of a porous triarylphosphine-based metal-organic framework (MOF) exhibited excellent activity in the hydrosilylation of ketones and alkenes, the hydrogenation of alkenes, and the C-H borylation of arenes. The recyclable and reusable MOF catalysts significantly outperformed their homogeneous counterparts, presumably via stabilizing M-PR3 intermediates by preventing deleterious disproportionation reactions/ligand exchanges in the catalytic cycles.

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We report the crystallization of homochiral polyoxometalate (POM) macroanions {CoSbO(HO)[Co(hmta)SbWO]} (, hmta = hexamethylenetetramine) the counter cation-mediated chiral symmetry breaking and asymmetric autocatalytic processes. In the presence of low Co concentrations both Δ- and Λ-enantiomers of formed in the reaction, crystallizing into the racemic crystal -. At a high Co concentration, the polyoxoanion enantiomers showed a high level of chiral recognition H-bonding interactions to crystallize into enantiopure crystals of Δ- or Λ-[Co(HO){CoSbO(HO)[Co(hmta)SbWO]}].

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Metal-organic frameworks (MOFs) provide a tunable platform for hierarchically integrating multiple components to effect synergistic functions that cannot be achieved in solution. Here we report the encapsulation of a Ni-containing polyoxometalate (POM) [Ni4 (H2 O)2 (PW9 O34 )2 ](10-) (Ni4 P2 ) into two highly stable and porous phosphorescent MOFs. The proximity of Ni4 P2 to multiple photosensitizers in Ni4 P2 @MOF allows for facile multi-electron transfer to enable efficient visible-light-driven hydrogen evolution reaction (HER) with turnover numbers as high as 1476.

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Metal-organic frameworks (MOFs) with light-harvesting building blocks designed to mimic photosynthetic chromophore arrays in green plants provide an excellent platform to study exciton transport in networks with well-defined structures. A step-by-step exciton random hopping model made of the elementary steps of energy transfer between only the nearest neighbors is usually used to describe the transport dynamics. Although such a nearest neighbor approximation is valid in describing the energy transfer of triplet states via the Dexter mechanism, we found it inadequate in evaluating singlet exciton migration that occurs through the Förster mechanism, which involves one-step jumping over longer distance.

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Metal-organic layers (MOLs) represent an emerging class of tunable and functionalizable two-dimensional materials. In this work, the scalable solvothermal synthesis of self-supporting MOLs composed of [Hf6O4(OH)4(HCO2)6] secondary building units (SBUs) and benzene-1,3,5-tribenzoate (BTB) bridging ligands is reported. The MOL structures were directly imaged by TEM and AFM, and doped with 4'-(4-benzoate)-(2,2',2''-terpyridine)-5,5''-dicarboxylate (TPY) before being coordinated with iron centers to afford highly active and reusable single-site solid catalysts for the hydrosilylation of terminal olefins.

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We have designed a strategy for postsynthesis installation of the β-diketiminate (NacNac) functionality in a metal-organic framework (MOF) of UiO-topology. Metalation of the NacNac-MOF (I) with earth-abundant metal salts afforded the desired MOF-supported NacNac-M complexes (M = Fe, Cu, and Co) with coordination environments established by detailed EXAFS studies. The NacNac-Fe-MOF catalyst, I•Fe(Me), efficiently catalyzed the challenging intramolecular sp(3) C-H amination of a series of alkyl azides to afford α-substituted pyrrolidines.

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