Bottom-Up Construction of Rhombic Lamellar CoNi-MOFs for the Electrochemical Sensing of H2S.

Lamellar metal-organic frameworks (MOFs) have attracted significant attention in the field of electrochemical sensing due to their abundant open active sites and specific electron conductivity. Herein, by employing a bottom-up synthesis strategy, rhombic lamellar heterometallic CoNi-MOFs with varying thicknesses are constructed. This is achieved by using 4-methylpyridine as a capping agent based on the (4,6)-linked Co2(azpy)2(bptc) (azpy = 4,4'-azopyridine, bptc = 3,3',5,5'-biphenyltetracarboxylic acid) structure with a fsc topology and by introducing Ni species simultaneously. To mitigate sulfur deposition on electrodes, the triple pulse amperometry (TPA) method is employed. Among the synthesized lamellar CoNi-MOFs, lamellar CoNi-MOF-3 with the minimum thickness exhibits an optimal electrochemical sensing performance toward hydrogen sulfide, with a sensitivity of 119.3 µA·mM-1·cm-2 in the linear range of 2-2000 µM. This study pioneers a new approach to the controlled construction and electrochemical activity modification of lamellar MOF materials.

Hierarchical surface-modification of nano-Cu toward one pot H-transfer-coupling-cyclization-CO2 fixation tandem reactions.

Fixation of CO2 into dihydroisobenzofuran derivatives has enormous applications in both production of natural products and antidepressant drugs, and reducing the green-house effect. However, the relatively complicated multi-step processes limit the further expansion of such a valuable CO2 conversion strategy. Herein, we hierarchically modify the surface of Cu nanoparticles (NPs) with Ag NPs and the robust metal-organic framework (MOF), ZIF-8, and report the presence of the Cu-Ag yolk-shell nanoalloy based heterogeneous catalysts, Cu@Ag and Cu@Ag@ZIF-8. The latter exhibits a crystalline "raisin bread" structure and specific synergic activity for catalyzing the tandem reactions of intra-molecular H-transfer, C-C and C-O coupling, cyclization, and carboxylation from CO2, leading to the first non-homogeneous preparation of dihydroisobenzofuran derivatives in high yield, selectivity, and recyclability under mild conditions. Theoretical calculations elucidate the tandem reaction pathway synergically catalyzed by Cu@Ag@ZIF-8, which offers insights for designing multiphase catalysts towards both organic synthesis and CO2 fixation through tandem processes in one pot.

3-O-Methyl-D-Glucose Blunts Cold Ischemia Damage in Kidney via Inhibiting Ferroptosis.

BACKGROUND: The glucose derivative 3-O-methyl-D-glucose (OMG) is used as a cryoprotectant in freezing cells. However, its protective role and the related mechanism in static cold storage (CS) of organs are unknown. The present study aimed to investigate the effect of OMG on cod ischemia damage in cold preservation of donor kidney. METHODS: Pretreatment of OMG on kidney was performed in an isolated renal cold storage model in rats. LDH activity in renal efflux was used to evaluate the cellular damage. Indicators including iron levels, mitochondrial damage, MDA level, and cellular apoptosis were measured. Kidney quality was assessed via a kidney transplantation (KTx) model in rats. The grafted animals were followed up for 7 days. Ischemia reperfusion (I/R) injury and inflammatory response were assessed by biochemical and histological analyses. RESULTS: OMG pretreatment alleviated prolonged CS-induced renal damage as evidenced by reduced LDH activities and tubular apoptosis. Kidney with pCS has significantly increased iron, MDA, and TUNEL+ cells, implying the increased ferroptosis, which has been partly inhibited by OMG. OMG pretreatment has improved the renal function (p <0.05) and prolonged the 7-day survival of the grafting recipients after KTx, as compared to the control group. OMG has significantly decreased inflammation and tubular damage after KTx, as evidenced by CD3-positive cells and TUNEL-positive cells. CONCLUSION: Our study demonstrated that OMG protected kidney against the prolonged cold ischemia-caused injuries through inhibiting ferroptosis. Our results suggested that OMG might have potential clinical application in cold preservation of donor kidney.

Crystal Engineering of a Chiral Crystalline Sponge That Enables Absolute Structure Determination and Enantiomeric Separation.

Chiral metal-organic materials (CMOMs), can offer molecular binding sites that mimic the enantioselectivity exhibited by biomolecules and are amenable to systematic fine-tuning of structure and properties. Herein, we report that the reaction of Ni(NO3)2, S-indoline-2-carboxylic acid (S-IDECH), and 4,4'-bipyridine (bipy) afforded a homochiral cationic diamondoid, dia, network, [Ni(S-IDEC)(bipy)(H2O)][NO3], CMOM-5. Composed of rod building blocks (RBBs) cross-linked by bipy linkers, the activated form of CMOM-5 adapted its pore structure to bind four guest molecules, 1-phenyl-1-butanol (1P1B), 4-phenyl-2-butanol (4P2B), 1-(4-methoxyphenyl)ethanol (MPE), and methyl mandelate (MM), making it an example of a chiral crystalline sponge (CCS). Chiral resolution experiments revealed enantiomeric excess, ee, values of 36.2-93.5%. The structural adaptability of CMOM-5 enabled eight enantiomer@CMOM-5 crystal structures to be determined. The five ordered crystal structures revealed that host-guest hydrogen-bonding interactions are behind the observed enantioselectivity, three of which represent the first crystal structures determined of the ambient liquids R-4P2B, S-4P2B, and R-MPE.

Ultrastable Cu-Based Dual-Channel Heterowire for the Switchable Electro-/Photocatalytic Reduction of CO2.

Catalytic conversion of CO2 into high value-added chemicals using renewable energy is an attractive strategy for the management of CO2 . However, achieving both efficiency and product selectivity remains a great challenge. Herein, a brand-new family of 1D dual-channel heterowires, Cu NWs@MOFs are constructed by coating metal-organic frameworks (MOFs) on Cu nanowires (Cu NWs) for electro-/photocatalytic CO2 reductions, where Cu NWs act as an electron channel to directionally transmit electrons, and the MOF cover acts as a molecule/photon channel to control the products and/or undertake photoelectric conversion. Through changing the type of MOF cover, the 1D heterowire is switched between electrocatalyst and photocatalyst for the reduction of CO2 with excellent selectivity, adjustable products, and the highest stability among the Cu-based CO2 RR catalysts, which leads to heterometallic MOF covered 1D composite, and especially the first 1D/1D-type Mott-Schottky heterojunction. Considering the diversity of MOF materials, the ultrastable heterowires offer a highly promising and feasible solution for CO2 reduction.

Tailored Sky-Parking Architectures of 3D Graphene Oxide Towards Highly-Efficient Water Purification.

The widespread use of chemicals has brought serious water pollution threatening human health and environment, which requires green, fast, and low-cost purification urgently. Here, we build up a novel material family of sky-parking-like 3D structured graphene oxides (SP-GOs) with adjustable interlayer-space of 0.8-1.7 nm via the insertion of different sized diamine compounds as support pillars between GO layers. The assembled 3D SP-GOs exhibit superior adsorption capacity and short removal time for various aromatic organic compounds in water, achieving record-breaking maximum adsorption capacity of 535.79 mg g-1 toward the most common water-pollutant bisphenol A (BPA) at ambient conditions as well as significantly improved removal of other organic pollutants including sulfapyridine, carbamazepine, ketoprofen and 2-naphthol. The construction of SP-GO provides a simple approach for evolving the GO material from 2D to 3D and a new avenue for the decontamination of pollutants in environmental remediation.

Highly Robust Microporous Metal-Organic Frameworks for Efficient Ethylene Purification under Dry and Humid Conditions.

Two C2 H6 -selective metal-organic framework (MOF) adsorbents with ultrahigh stability, high surface areas, and suitable pore size have been designed and synthesized for one-step separation of ethane/ethylene (C2 H6 /C2 H4 ) under humid conditions to produce polymer-grade pure C2 H4 . Experimental results reveal that these two MOFs not only adsorb a high amount of C2 H6 but also display good C2 H6 /C2 H4 selectivity verified by fixed bed column breakthrough experiments. Most importantly, the good water stability and hydrophobic pore environments make these two MOFs capable of efficiently separating C2 H6 /C2 H4 under humid conditions, exhibiting the benchmark performance among all reported adsorbents for separation of C2 H6 /C2 H4 under humid conditions. Moreover, the affinity sites and their static adsorption energies were successfully revealed by single crystal data and computation studies. Adsorbents described in this work can be used to address major chemical industrial challenges.

Pseudocapsule and pseudocapsule-based extracapsular resection in pituitary neuroendocrine tumors.

Since Costello et al. proposed the concept of pseudocapsule of pituitary neuroendocrine tumors (PitNETs) in 1936, many studies have been published on its occurrence, development process, histopathology, and morphology. Pseudocapsule has been proposed as the anatomical interface between PitNETs and normal pituitary gland, therefore the so-called pseudocapsule-based extracapsular resection (ER) technique was developed as an extracapsular surgery method for PitNETs,which differs from the conventional intracapsular resection (IR). In recent years, ER has also been widely used in patients of different tumor types, sizes, and age groups, because the pseudocapsule can be identified more clearly under the endoscopy. Endoscopic transsphenoidal resection for PitNETs has become the preferred surgical method. We reviewed relevant literatures in the past 10 years, showing that ER could achieve better rate of gross total resection (GTR) and biochemical remission, and reduce tumor recurrence than IR, without increasing postoperative complications. Therefore, the pseudocapsule and ER should be valued by neurosurgeons and actively promoted clinically.

Protocol to modify the surface of nano-Cu2O using facet controlling and MOF shell coating.

The morphology of nano-Cu2O profoundly determines its catalytic performance. Here, we provide two universal and reliable techniques to modify the surface of nano-Cu2O. First, we detail steps for the systematic tuning of the exposed facets of nano-Cu2O ranging from low index to high index using reductant-controlled technique in the presence of sodium dodecyl sulfate. Second, we describe steps for facet-directed precipitation in which the morphology-dependent ZIF-8 (a type of zeolitic imidazolate frameworks) shells on different nano-Cu2O are well introduced. For complete details on the use and execution of this protocol, please refer to Luo et al. (2022).

MOF-Incorporated Binuclear N-Heterocyclic Carbene-Cobalt Catalyst for Efficient Conversion of CO2 to Formamides.

Environmental problem caused by carbon emission is of widespread concern. Involving CO2 as C1 resource into chemical synthesis is one of the most attractive ways for carbon recycling. Herein, the first example of host-guest composites featuring metal-organic framework (MOF)-encapsulated binuclear N-heterocyclic carbene (NHC) complex, Co2 @MIL101, was developed with the molecularly dispersed [Co(IPr)Br]2 (µ-Br)2 (Co2 ) loading in the cage of MIL-101(Cr) via a "ligand-in-dimer-trap" strategy, which was comprehensively investigated through various techniques including synchrotron X-ray absorption, electron microscopy, X-ray diffraction, solid-state nuclear magnetic resonance spectroscopy, and others. The noble-metal-free double-sites catalyst Co2 @MIL101 exhibited promising stability, activity, efficiency, reusability, and substrate adaptability for converting CO2 into various formamides with amines and hydrosilanes and achieved the best performance for one of the most useful formamides, N-methyl-N-phenylformamide (MFA), among the recyclable catalysts at ambient conditions, providing a reliable approach to successfully unify the advantages of both homo- and heterogeneous catalysts. Density functional theory calculations were applied to illustrate the superior activity of the binuclear NHC complex center as double-sites catalyst toward the activation of CO2 .

Hybrid Metal-Organic Frameworks Encapsulated Hybrid Ni-Doped CdS Nanoparticles for Visible-Light-Driven CO2 Reduction.

The photocatalytic production of syngas from CO2 and water is an attractive and straightforward way for both solar energy storage and sustainable development. Here, we combined the hybrid shell of a bimetallic metal-organic framework (MOF) Zn/Co-zeolitic imidazolate framework (ZIF) and the hybrid photoactive center of Ni-doped CdS nanoparticles (Ni@CdS) to construct a new "2 + 2" photocatalysis system Ni@CdS⊂Zn/Co-ZIF through a facile self-assembly process, which exhibited a double-synergic effect for visible light harvesting and CO2 conversion, leading to one of the highest photocatalytic syngas production rates and excellent recyclability. The H2/CO of syngas ratios can be readily adjusted by controlling the ratio of Zn/Co in the hybrid MOF shell.

Effects of prolonged cold ischemia on the DCD kidney function and Inflammasome expression in rat kidney transplants.

BACKGROUND: Acute kidney injury (AKI) is the main reason for the bad outcome of the donation of circulatory death (DCD) kidney after transplantation. Prolonged cold storage (CS) is a risk factor for the occurrence of the delayed graft function in DCD kidney. The protein NLR-domain containing receptor 3 (NLRP3) plays a crucial role in renal ischemia reperfusion injury by triggering inflammasome formation. Herein, we investigated whether the NLRP3 signal participate in the CS-induced damage of DCD kidney in rat kidney transplantation models. MATERIALS AND METHODS: DCD kidney and living donor (LD) kidney of SD rats were preserved in UW solution at 4 °C for 2 h or 18 h, and then transplanted into syngeneic recipient. Thus, the animals were randomly divided into 4 groups: 2-h LD group, 2-h DCD group, 18-h LD group and 18-h DCD group. The renal function and pathological changes were determined. The expressions of NLRP3 and inflammatory factor IL-1ß were assessed. The concentration of ferrous iron (Fe2+) was analyzed both in kidneys and in the preservation solution. The renal morphological changes were examined by hematoxylin eosin staining. RESULTS: Our results showed that the levels of Cr and BUN were higher in 18-h LD group as compared to the 2-h LD group, which were remarkably increased in 18-h DCD group. The expression levels of NLRP3 and IL-1ß were increased by 18-h CS compared to 2-h CS in both LD kidney and DCD kidney. In addition, the Fe2+ concentration has significantly increased in 18-h LD group than that in 2-h LD group, and the elevation of Fe2+ was more remarkable in DCD kidneys. CONCLUSION: In conclusion, our study demonstrated that prolonged hypothermic storage of DCD kidney deteriorated the graft function via the increased Fe2+ concentration, which was associated with the upregulation of NLRP3 expression.

Surface Modification of Nano-Cu2 O for Controlling CO2 Electrochemical Reduction to Ethylene and Syngas.

In the surroundings of carbon neutrality, nano-Cu2 O is considered a promising catalyst for the electrochemical CO2 reduction reaction (ECO2 RR), whose improvements in product selectivity still require considerable efforts. Here, we present an efficient strategy for controlling the ECO2 RR product by modifying the surface of nano-Cu2 O, i.e., by controlling the exposed facets via a reductant-controlled method to achieve the highest C2 H4 selectivity (Faradic efficiency=74.1 %) for Cu2 O-based catalysts in neutral electrolytes, and introducing a well-suited metal-organic framework (MOF) coating on the surface of nano-Cu2 O to obtain syngas completely with an appropriate H2 :CO ratio. Detailed mechanism and key intermediate have been illustrated by DFT calculations. Our systematic strategy is expected to control the ECO2 RR product, improve the selectivity, and provide a reliable method for CO2 management and the green production of important carbon resources.

Construction of CuII Defects on CuCl Nanoparticles in Metal-Organic Frameworks toward Composite Catalysts with Superior Activity.

Metal-organic frameworks (MOFs) represent an ideal platform for the construction of highly active composite catalysts. However, loading metastable and/or multicomponent metal compounds into MOFs remains a synthetic bottleneck due to the great challenge of keeping the guest and matrix intact during the preparation of a composite. In this work, we develop a new impregnation reduction surface modification (IRSM) strategy to give a new composite catalyst CuCl@MIL-101(Cr), which is successfully postmodified by in situ construction of CuII defects on the surface of loaded CuCl inside MOF pores, leading to the new composite material CuII/CuI@MIL-101(Cr). The new dual-component composite catalyst exhibits a hierarchical structure and superior catalytic activity in C-C homocoupling of arylboronic acids under green conditions. This study presents a facile strategy for improving the catalytic activity by constructing defects on the surface of MOF-based catalysts as well as for forming multiple-component composite materials.

Fabrication of Moisture-Responsive Crystalline Smart Materials for Water Harvesting and Electricity Transduction.

It is of profound significance with regard to the global energy crisis to develop new techniques and materials that can convert the chemical potential of water into other forms of energy, especially electricity. To address this challenge, we built a new type of energy transduction pathway (humidity gradients → mechanical work → electrical power) using moisture-responsive crystalline materials as the media for energy transduction. Single-crystal data revealed that a flexible zeolitic pyrimidine framework material, ZPF-2-Co, could undergo a reversible structural transformation (ß to α phase) with a large unit cell change upon moisture stimulus. Dynamic water vapor sorption analysis showed a gate-opening effect with a steep uptake at as low as 10% relative humidity (RH). The scalable green synthesis approach and the fast water vapor adsorption-desorption kinetics made ZPF-2-Co an excellent sorbent to harvest water from arid air, as verified by real water-harvesting experiments. Furthermore, we created a gradient distribution strategy to fabricate polymer-hybridized mechanical actuators based on ZPF-2-Co that could perform reversible bending deformation upon a variation of the humidity gradient. This mechanical actuator showed remarkable durability and reusability. Finally, coupling the moisture-responsive actuator with a piezoelectric transducer further converted the mechanical work into electrical power. This work offers a new type of moisture-responsive smart material for energy transduction and provides an in-depth understanding of the responsive mechanism at the molecular level.

Controlled Thermal Conversion Strategy to Provide Metal-Organic Framework-Supported Composite Catalysts.

Metal-organic framework (MOF)-supported metal/metal compound nanoparticles (NPs) have emerged as a new class of composite catalysts. However, huge challenges prevail in placing such NPs in the MOF pores because of the poor solubility of metal/metal oxides, limited availability of suitable precursors, metastable attribute of given metal ions, and lower thermal stability of MOFs compared to conventional porous materials. Based on the difference between the thermal stability of the precursor and MOFs, we successfully developed a controlled thermal conversion (CTC) method to load cobalt(II) oxide (CoO) NPs into the framework of MOF (MIL-101) to conveniently obtain a composite catalyst, CoO@MIL-101, which is a very rare example of pure CoO NP-loaded composite catalyst that shows excellent catalytic activity in the selective oxidation of benzyl alcohol. This CTC strategy opens up a pathway for impregnating MOF supports with specific NPs, which is further confirmed by preparing the first CuBr@MOF-type composite catalyst.

Conversion of CO2 to Heterocyclohexenol Carboxylic Acids through a Metal-Organic Framework Sponge.

The conversion of CO2 into high value-added chemical products is the focus of current scientific research. We make use of the specific porous structure of nanosized metal-organic frameworks (MOFs) loading the highly active yet metastable nano Cu2O to catalyze the conversion of CO2 into a series of high value-added bioactive pyridone/pyrone-3-carboxylic acid products via heterocyclic 4-hydroxy-2-pyridones/pyrones, which exhibit high activity, selectivity, and reusability. Nano MOF sponge-covered metastable nanoparticles (NPs) converting CO2 into high value-added bioproducts provide a facile "dual-side surfactant" strategy, a highly efficient composite catalyst, and a practicable pathway not only for the sustainable use of CO2 but also for environment-friendly production of bioproducts.

Application of MOF-based materials in electrochemical sensing.

Metal-organic frameworks (MOFs) have risen as a kind of porous materials that are constructed by the coordination of organic ligands to metal centers or clusters, providing compelling potential for various fields of research. In this frontier article, we demonstrate the recent developments in MOF-based materials for electrochemical sensing applications, and the current challenges and some prospects in this field are also discussed.

A systematic investigation of structural transformation in a copper pyrazolato system: a case study.

Dissolution-recrystallization structural transformation (DRST) is a powerful tool to unravel unequivocally the mechanism of dynamic conversion processes, based on the structures of the initial reactants, final products and sometimes intermediates isolated from the reaction mixture. Herein, we illustrate the details of the conversion processes of (CuIpz)3 into [CuII(OH)pz]6 (pzH = 4-chloro-3,5-diphenylpyrazole) through DRSTs. Based on crystal structure determination and spectroscopic methods, the most encountered species, (CuIpz)3, is in equilibrium with (CuIpz)4 in solution with the tetramer becoming dominant at low temperature, indicating an entropy-controlled conversion between these two structural isomers. The CuI trimer/tetramer in solution further experiences an oxidation if exposed to the open air, resulting in the formation of a pentanuclear mixed-valence intermediate CuI3CuII2(OMe)2pz5 which can be isolated as single crystals at -20 °C and has been structurally characterized for the first time. The final product isolated from the solution is the fully oxidized hexanuclear [CuII(OMe)pz]6, which is easily transformed into [CuII(OH)pz]6 in the presence of humidity.

Basilar Artery Tortuosity Is Associated With White Matter Hyperintensities by TIMP-1.

BACKGROUND AND PURPOSE: To test the hypothesis that the imbalance between matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) may play a potential role in bridging vertebrobasilar dolichoectasia (VBD) with lacunar infarction (LI) and white matter hyperintensities (WMH). METHODS: We studied 212 patients with vertigo who underwent multimodal magnetic resonance imaging (MRI) tests for VBD, LI, and WMH identification. We investigated biomarkers of VBD with magnetic resonance angiography (MRA) via various physical characteristics of the vertebrobasilar arteries (VBAs). Similarly, LI and WMH biomarkers were extracted using T2-weighted and fluid attenuated inversion recovery (FLAIR) images. We first determined which of these neuroimaging markers were significant identifiers of VBD, LI and the different grades of WMH. We then sought to draw potential mechanistic conclusions from these MRI-derived parameters, by associating the aforementioned biomarkers with MMP and TIMP serum levels in patient blood samples using non-parametric statistical tests. RESULTS: MMP-9 serum level was significantly higher in vertigo patients with VBAs dilation and basilar artery (BA) elongation compared to those with healthy arterial size, and the ratio of MMP-9/TIMP-1 level were higher in those patients. TIMP-1 level was also markedly higher in vertigo patients with BA tortuosity than those without BA tortuosity. The bending length (BL) of the BA was positively correlated with TIMP-1. The length, BL, and tortuosity index of the BA, as well as serum levels of TIMP-1 were greater in patients with higher WMH grades compared to those with low WMH grades. The vertebral artery and BA diameters, and the levels of MMP-2, -3, -9, TIMP-2 and cathepsin L were similar in patients with different WMH grades. CONCLUSION: In vertigo patients, we found various probably associations between MMP-9 and TIMP-1 with arterial alterations linked to both VBD and WMH that may help with the diagnosis and treatment of such diseases in the future.