Anion Modulation of Ag-Imidazole Cuboctahedral Cage Microenvironments for Efficient Electrocatalytic CO2 Reduction.

How to achieve CO2 electroreduction in high efficiency is a current challenge with the mechanism not well understood yet. The metal-organic cages with multiple metal sites, tunable active centers, and well-defined microenvironments may provide a promising catalyst model. Here, we report self-assembly of Ag4L4 type cuboctahedral cages from coordination dynamic Ag+ ion and triangular imidazolyl ligand 1,3,5-tris(1-benzylbenzimidazol-2-yl) benzene (Ag-MOC-X, X=NO3, ClO4, BF4) via anion template effect. Notably, Ag-MOC-NO3 achieves the highest CO faradaic efficiency in pH-universal electrolytes of 86.1 % (acidic), 94.1 % (neutral) and 95.3 % (alkaline), much higher than those of Ag-MOC-ClO4 and Ag-MOC-BF4 with just different counter anions. In situ attenuated total reflection Fourier transform infrared spectroscopy observes formation of vital intermediate *COOH for CO2-to-CO conversion. The density functional theory calculations suggest that the adsorption of CO2 on unsaturated Ag-site is stabilized by C-H⋅⋅⋅O hydrogen-bonding of CO2 in a microenvironment surrounded by three benzimidazole rings, and the activation of CO2 is dependent on the coordination dynamics of Ag-centers modulated by the hosted anions through Ag⋅⋅⋅X interactions. This work offers a supramolecular electrocatalytic strategy based on Ag-coordination geometry and host-guest interaction regulation of MOCs as high-efficient electrocatalysts for CO2 reduction to CO which is a key intermediate in chemical industry process.

Synergistic Modulation of Electronic Interaction to Enhance Intrinsic Activity and Conductivity of Fe-Co-Ni Hydroxide Nanotube for Highly Efficient Oxygen Evolution Electrocatalyst.

The large-scale hydrogen production and application through electrocatalytic water splitting depends crucially on the development of highly efficient, cost-effective electrocatalysts for oxygen evolution reaction (OER), which, however, remains challenging. Here, a new electrocatalyst of trimetallic Fe-Co-Ni hydroxide (denoted as FeCoNiOx Hy ) with a nanotubular structure is developed through an enhanced Kirkendall process under applied potential. The FeCoNiOx Hy features synergistic electronic interaction between Fe, Co, and Ni, which not only notably increases the intrinsic OER activity of FeCoNiOx Hy by facilitating the formation of *OOH intermediate, but also substantially improves the intrinsic conductivity of FeCoNiOx Hy to facilitate charge transfer and activate catalytic sites through electrocatalyst by promoting the formation of abundant Co3+ . Therefore, FeCoNiOx Hy delivers remarkably accelerated OER kinetics and superior apparent activity, indicated by an ultra-low overpotential potential of 257 mV at a high current density of 200 mA cm-2 . This work is of fundamental and practical significance for synergistic catalysis related to advanced energy conversion materials and technologies.

Engineering Single-Atom Sites into Pore-Confined Nanospaces of Porphyrinic Metal-Organic Frameworks for the Highly Efficient Photocatalytic Hydrogen Evolution Reaction.

As a type of heterogeneous catalyst expected for the maximum atom efficiency, a series of single-atom catalysts (SACs) containing spatially isolated metal single atoms (M-SAs) have been successfully prepared by confining M-SAs in the pore-nanospaces of porphyrinic metal-organic frameworks (MOFs). The prepared MOF composites of M-SAs@Pd-PCN-222-NH2 (M = Pt, Ir, Au, and Ru) display exceptionally high and persistent efficiency in the photocatalytic hydrogen evolution reaction with a turnover number (TON) of up to 21713 in 32 h and a beginning/lasting turnover frequency (TOF) larger than 1200/600 h-1 based on M-SAs under visible light irradiation (λ ≥ 420 nm). The photo-/electrochemical property studies and density functional theory calculations disclose that the close proximity of the catalytically active Pt-SAs to the Pd-porphyrin photosensitizers with the confinement and stabilization effect by chemical binding could accelerate electron-hole separation and charge transfer in pore-nanospaces, thus promoting the catalytic H2 evolution reaction with lasting effectiveness.

240-week entecavir maleate treatment in Chinese chronic hepatitis B predominantly genotype B or C.

This study aimed to evaluate the efficacy and safety of entecavir(ETV) versus ETV maleate in Chinese patients with chronic hepatitis B(CHB). This was a randomized, double-blind, double-dummy, controlled, multicentre study. Patients were randomly assigned to receive 48 weeks of treatment with 0.5 mg/day ETV (group A) or 0.5 mg/day ETV maleate (group B), then, all patients received treatment with 0.5 mg/day ETV maleate from week 49 onwards. Patients were regularly followed up. Serum hepatitis B virus (HBV) markers were detected. Adverse events (AE) were recorded. The primary endpoint was the decline in HBV DNA in each group at the end of treatment. Secondary endpoints included the rate of HBV DNA below the lower limit of detection (LLOD) (20 I U/ml) at the end of treatment, the rate of hepatitis B e antigen (HBeAg) loss, the rate of HBeAg seroconversion and serum alanine aminotransferase (ALT) normalization. One hundred and thirty-seven (71 in group A) patients with HBeAg-positive CHB and 46 (21 in group A) patients with HBeAg-negative CHB completed the 240-week treatment and follow-up. Baseline characteristics were well balanced between the two groups. For the HBeAg-positive CHB patients, the mean HBV DNA level had similarly decreased from baseline in both groups (A: by 6.67 log10 IU/ml vs. B: by 6.74 log10 IU/ml; p > .05) at Week 240. Patients who achieved undetectable levels of serum HBV DNA (<20 IU/ml) at Week 240 were similar between groups (A:91.55% vs. B:87.88%; p > .05). Both groups achieved similar HBeAg seroconversion rates at week 240 (A:26.98% vs. B:20.97%; p > .05). Both groups achieved similar normalization of ALT (A:87.32% vs. B:83.61%; p > .05) at Week 240 (p > .05). For the HBeAg-negative CHB patients, the mean HBV DNA level had similarly decreased from baseline in both groups (A: by 6.05 log10 IU/ml vs. B: by 6.10 log10 IU/ml; p > .05) at Week 240. Patients who achieved undetectable levels of serum HBV DNA at Week 240 were similar between groups (A:100% vs. B:100%). Both groups achieved similar normalization rates (A:90.91% vs. B: 95.45%; p > .05) of ALT at Week 240 (p > .05). In conclusion, long-term ETV maleate treatment was safe and efficient in Chinese CHB predominantly of genotype B or C.

Co-Fe-P Nanosheet Arrays as a Highly Synergistic and Efficient Electrocatalyst for Oxygen Evolution Reaction.

The rational design and synthesis of highly efficient electrocatalysts for oxygen evolution reaction (OER) is of critical importance to the large-scale production of hydrogen by water electrolysis. Here, we develop a bimetallic, synergistic, and highly efficient Co-Fe-P electrocatalyst for OER, by selecting a two-dimensional metal-organic framework (MOF) of Co-ZIF-L as the precursor. The Co-Fe-P electrocatalyst features pronounced synergistic effects induced by notable electron transfer from Co to Fe, and a large electrochemical active surface area achieved by organizing the synergistic Co-Fe-P into hierarchical nanosheet arrays with disordered grain boundaries. Such features facilitate the generation of abundant and efficiently exposed Co3+ sites for electrocatalytic OER and thus enable Co-Fe-P to deliver excellent activity (overpotential and Tafel slope as low as 240 mV and 36 mV dec-1, respectively, at a current density of 10 mA cm-2 in 1.0 M KOH solution). The Co-Fe-P electrocatalyst also shows great durability by steadily working for up to 24 h. Our work thus provides new insight into the development of highly efficient electrocatalysts based on nanoscale and/or electronic structure engineering.

Pressure Loading Induces DNA Damage in Human Hepatocyte Line L02 Cells via the ERK1/2-Dicer Signaling Pathway.

Alteration of liver tissue mechanical microenvironment is proven to be a key factor for causing hepatocyte injury and even triggering the occurrence of hepatocellular carcinoma; however, the underlying mechanisms involved are not fully understood. In this study, using a customized, pressure-loading device, we assess the effect of pressure loading on DNA damage in human hepatocytes. We show that pressure loading leads to DNA damage and S-phase arresting in the cell cycle, and activates the DNA damage response in hepatocytes. Meanwhile, pressure loading upregulates Dicer expression, and its silencing exacerbates pressure-induced DNA damage. Moreover, pressure loading also activates ERK1/2 signaling molecules. Blockage of ERK1/2 signaling inhibits pressure-upregulated Dicer expression and exacerbates DNA damage by suppressing DNA damage response in hepatocytes. Our findings demonstrate that compressive stress loading induces hepatocyte DNA damage through the ERK1/2-Dicer signaling pathway, which provides evidence for a better understanding of the link between the altered mechanical environment and liver diseases.

High-Temperature and Dynamic RGB (Red-Green-Blue) Long-Persistent Luminescence in an Anti-Kasha Organic Compound.

Organic LPL (long-persistent luminescence) materials have sparked extensive research interest due to the ultralong-lived triplet states. Although numerous organic LPL materials have been reported, most of the triplet emission was static and monotonous. Therefore, LPL materials with dynamic triplet emission are urgently required. A triamino-s-triazine derivative 1 with dynamic LPL was fabricated. The single-crystal structure shows that the abundant intermolecular interactions and small free volume restrict the molecular motion and avoid the quenchers. Spectral and theoretical calculations upheld the existence of multiple excited states in 1, and the migration of electrons between multiple excited states is very sensitive to external stimuli. By modulating the stimulus, the residence of electrons in different triplet states can be manipulated to achieve RGB LPL. Importantly, blue LPL was achieved by manipulating the anti-Kasha emission. And the red LPL can still be observed at high temperature.

High Water Adsorption MOFs with Optimized Pore-Nanospaces for Autonomous Indoor Humidity Control and Pollutants Removal.

The indoor air quality is of prime importance for human daily life and health, for which the adsorbents like zeolites and silica-gels are widely used for air dehumidification and harmful gases capture. Herein, we develop a pore-nanospace post-engineering strategy to optimize the hydrophilicity, water-uptake capacity and air-purifying ability of metal-organic frameworks (MOFs) with long-term stability, offering an ideal candidate with autonomous multi-functionality of moisture control and pollutants sequestration. Through variant tuning of organic-linkers carrying hydrophobic and hydrophilic groups in the pore-nanospaces of prototypical UiO-67, a moderately hydrophilic MOF (UiO-67-4Me-NH2 -38 %) with high thermal, hydrolytic and acid-base stability is screened out, featuring S-shaped water sorption isotherms exactly located in the recommended comfortable and healthy ranges of relative humidity for indoor ventilation (45 %-65 % RH) and adverse health effects minimization (40-60 % RH). Its exceptional attributes of water-uptake working capacity/efficiency, contaminants removal, recyclability and regeneration promise a great potential in confined indoor environment application.

One and Two-Photon Excited Fluorescence Optimization of Metal-Organic Frameworks with Symmetry-Reduced AIEgen-Ligand.

By designing a tetraphenylethylene (TPE)-based AIEgen-ligand with reduced symmetry, we obtained two alkaline-earth metal-based MOFs (LIFM-102 and LIFM-103) with dense packing structures and low porosity as proved by single-crystal X-ray diffraction and CO2 sorption data. Excitingly, the desolvated MOFs with rigid environment and reduced lattice free solvent exhibit high quantum yields (QY, 64.9 % and 79.4 %) and excellent two-photon excited photoluminescence (TPA cross-sections, 2946.6 GM and 2899.0 GM), while maintaining the external-stimuli-responsive properties suitable for anticounterfeit fields. The effect of ligand conformation was validated by comparing the structure and fluorescence properties of the samples before and after desolvation and further verified by theoretical calculations. This work expands the study on TPE-cored materials to symmetry-reduced ligand and might bring forward novel structures and excellent photoluminescent properties in the future.

A flexible data-driven cyclostationary model for the probability density of El Niño-Southern Oscillation.

Model simulations of El Niño-Southern Oscillation (ENSO) are usually evaluated by comparing them to observations using a multitude of metrics. However, this approach cannot provide an objective summary metric of model performance. Here, we propose that such an objective model evaluation should involve comparing the full joint probability density functions (pdf's) of ENSO. For simplicity, ENSO state is defined here as sea surface temperature anomalies over the Niño 3 region and equatorial Pacific thermocline depth anomalies. We argue that all ENSO metrics are a function of the joint pdf, the latter fully specifying the underlying stochastic process. Unfortunately, there is a lack of methods to recover the joint ENSO pdf from climate models or observations. Here, we develop a data-driven stochastic model for ENSO that allows for an analytic solution of the non-Markov non-Gaussian cyclostationary ENSO pdf. We show that the model can explain relevant ENSO features found in the observations and can serve as an ENSO simulator. We demonstrate that the model can reasonably approximate ENSO in most GCMs and is useful at exploring the internal ENSO variability. The general approach is not limited to ENSO and could be applied to other cyclostationary processes.

Single-Channel Blind Source Separation of Spatial Aliasing Signal Based on Stacked-LSTM.

Aiming at the problem of insufficient separation accuracy of aliased signals in space Internet satellite-ground communication scenarios, a stacked long short-term memory network (Stacked-LSTM) separation method based on deep learning is proposed. First, the coding feature representation of the mixed signal is extracted. Then, the long sequence input is divided into smaller blocks through the Stacked-LSTM network with the attention mechanism of the SE module, and the deep feature mask of the source signal is trained to obtain the Hadamard product of the mask of each source and the coding feature of the mixed signal, which is the encoding feature representation of the source signal. Finally, characteristics of the source signal is decoded by 1-D convolution to to obtain the original waveform. The negative scale-invariant source-to-noise ratio (SISNR) is used as the loss function of network training, that is, the evaluation index of single-channel blind source separation performance. The results show that in the single-channel separation of spatially aliased signals, the Stacked-LSTM method improves SISNR by 10.09∼38.17 dB compared with the two classic separation algorithms of ICA and NMF and the three deep learning separation methods of TasNet, Conv-TasNet and Wave-U-Net. The Stacked-LSTM method has better separation accuracy and noise robustness.

Programmable Delivery of Immune Adjuvant to Tumor-Infiltrating Dendritic Cells for Cancer Immunotherapy.

Tumor-infiltrating dendritic cells (TIDCs) are mostly immature and immunosuppressive, usually mediating immune inhibition. The utilization of cytosine-guanine oligodeoxynucleotides (CpG ODNs) to stimulate the activation of TIDCs has been demonstrated to be effective for improving antitumor immunity. However, a series of biological barriers has limited the efficacy of previous nanocarriers for delivering CpG to TIDCs. Herein, we developed a dual-sensitive dendrimer cluster-based nanoadjuvant for delivering CpG ODNs into TIDCs. We show that the tumor acidity triggers the rapid release of CpG conjugated polyamidoamine (PAMAM) dendrimers from the nanoadjuvant, thus facilitating its perfusion deep into tumors and phagocytosis by TIDCs. Thereafter, the reductive condition of the endolysosomes led to the subsequent release of CpG, which promotes the DCs activation and enhances antitumor immunotherapies. Programmable delivery of immune adjuvant efficiently overcomes the barriers for targeted delivery to TIDCs and provides a promising strategy for improving cancer immunotherapy.

LncRNA NKILA integrates RXFP1/AKT and NF-κB signalling to regulate osteogenesis of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are previously found to have potential capacity to differentiate into osteocytes when exposed to specific stimuli. However, the detailed molecular mechanism during this progress remains largely unknown. In the current study, we characterized the lncRNA NKILA as a crucial positive regulator for osteogenesis of MSCs. NKILA attenuation significantly inhibits the calcium deposition and alkaline phosphatase activity of MSCs. More interestingly, we defined that NKILA is functionally involved in the regulation of RXFP1/PI3K-AKT and NF-κB signalling. Knockdown of NKILA dramatically down-regulates the expression of RXFP1 and then reduces the activity of AKT, a downstream regulator of RXFP1 signalling which is widely accepted as an activator of osteogenesis. Moreover, we identify NF-κB as another critical regulator implicated in NKILA-mediated osteogenic differentiation. Inhibition of NF-κB can induce the expression of RUNX2, a master transcription factor of osteogenesis, in a HDAC2-mediated deacetylation manner. Thus, this study illustrates the regulatory function of NKILA in osteogenesis through distinct signalling pathways, therefore providing a new insight into searching for new molecular targets for bone tissue repair and regeneration.

PSMC6 promotes osteoblast apoptosis through inhibiting PI3K/AKT signaling pathway activation in ovariectomy-induced osteoporosis mouse model.

There is now increasing evidence which suggests a key role for osteoblast apoptosis in the pathogenesis of postmenopausal osteoporosis. Here, we evaluated the role and mechanism of proteasome 26S subunit, ATPase (PSMC) 6, a protein that is highly expressed in bone. Gene expression pattern had been extracted based on database of Gene Expression Omnibus (GEO). GEO2R was employed for analyses, while the DAVID database was adopted to further analyze the gene ontology (GO) as well as Kyoto Encyclopedia of Genomes pathway (KEGG) enrichment. Then, the Search Tool Retrieval of Interacting Genes (STRING) was utilized to carry out interaction regulatory network for the top 200 differentially expressed genes (DEGs). A key gene, called PSMC6, was identified by Cytoscape 3.6.0. The OVX osteoporosis model was established in female C57BL/6 mice by full bilateral ovariectomy. According to our findings, PSMC6 gene knockout would elevate bone mineral density (BMD) and the phosphorylation level of PI3K protein and increased the protein level of cleaved caspase-3/-9 in OVX osteoporosis mice. Further, MTT, bromodeoxyuridine, and flow cytometry assays revealed that PSMC6 inhibition promoted the progression of cell cycle and cell proliferation, whereas, PSMC6 overexpression promoted the apoptosis and inhibited cell cycle progression and cell proliferation in vitro. Besides, we found that PI3K activation significantly decreased PSMC6-induced osteoblast apoptosis and promoted cell proliferation through regulating the protein levels of p53, cyclinD1, and cleaved caspase-3/9. In conclusion, PSMC6 aggravated the degree of OVX-induced osteoporosis by inhibiting the PI3K/AKT signal transduction pathway, thereby promoting the apoptosis of osteoblasts.

Dynamic Coordination Chemistry of Fluorinated Zr-MOFs: Synthetic Control and Reassembly/Disassembly Beyond de Novo Synthesis to Tune the Structure and Property.

Known for excellent stability, porosity and functionality, the high-valent Zr4+ metal-organic frameworks (Zr-MOFs) still meets synthetic challenge in modulating the strength of Zr-Ocarboxylate linkage. Herein we explore the unusual coordination dynamics of fluorinated Zr-MOFs by designing two trifluoromethyl modified ligands with distinct geometry preference to form a family of thermodynamic and kinetic products. The low-connecting kinetic Zr-MOFs possess substitutable coordination sites to endow Zr6 -cluster with extra dynamic behaviors, thus opening a post-synthetic pathway to sequential reassembly/disassembly processes. Comprehensive factors, including ligand geometry, Zr6 -cluster connectivity, acid modulator and reaction temperature/concentration, have been studied for controllable syntheses. The stability, hydrophobicity and gas adsorption/separation properties of obtained Zr-MOFs are explored. This work sheds light on the understanding of the dynamic coordination chemistry of Zr-MOFs beyond strong Zr-O bond, which poses a versatile platform for modification and functionalization of Zr-MOFs.

Redox-Guest-Induced Multimode Photoluminescence Switch for Sequential Logic Gates in a Photoactive Coordination Cage.

Molecular or supramolecular level photoluminescence (PL) modulation combining chemical and photonic input/output signals together in an integrated system can provide potential high-density data memorizing and process functions intended for miniaturized devices and machines. Herein, a PL-responsive supramolecular coordination cage has been demonstrated for complex interactions with redox-active guests. PL signals of the cage can be switched and modulated by adding or retracting Fc derivatives or converting TTF into different oxidation states through chemical or photochemical pathways. As a result, reversible or stepwise PL responses are displayed by these host-guest systems because of the occurrence of photoinduced electron-transfer (PET) or fluorescence resonance energy transfer (FREnT) processes, providing unique nanodevice models bearing off/on logic gates or memristor-like sequential memory and Boolean operation functions.

Hollow Cobalt Phosphide with N-Doped Carbon Skeleton as Bifunctional Electrocatalyst for Overall Water Splitting.

The development of cost-effective, high-performance, and robust bifunctional electrocatalysts for overall water splitting remains highly desirable yet quite challenging. Here, by selecting appreciate precursors of dopamine and a Co-containing metal-organic framework of ZIF-67, we subtly couple their reaction processes to develop a facile approach for the synthesis of a hollow CoP nanostructure with N-doped carbon skeleton (H-CoP@NC). Benefiting from the highly porous nanostructure and conductive carbon skeleton, H-CoP@NC is capable of working as highly active and durable bifunctional electrocatalyst for both hydrogen and oxygen evolution reaction. When further used as the electrocatalyst for overall water splitting, H-CoP@NC delivers excellent activity (cell voltage of 1.72 V at a current density of 10 mA cm-2), close to that of the noble-metal-based benchmark catalyst couple of Pt/C||RuO2. Our work thus provides new insights into the development of transitional metal phosphides based hollow hybrid nanostructures, particularly those with multiple functionalities in sustainable energy conversion technologies and systems.

Pressure-Induced Multiphoton Excited Fluorochromic Metal-Organic Frameworks for Improving MPEF Properties.

In multiphoton excited fluorescence (MPEF), high-energy upconversion emission is obtained from low-energy excitation by absorbance of two or more photons simultaneously. In a pressure-induced fluorochromic process, the emission energy is switched by outer pressure stimuli. Now, five metal-organic frameworks containing the same ligand with simultaneous multiphoton absorption and pressure-induced fluorochromic attributes were studied. One-, two-, and three-photon excited fluorescence (1/2/3PEF) can be achieved in the frameworks, which exhibit pressure-induced blue-to-yellow fluorochromism. The performances are closely dependent with the topologies, flexibilities, and packing states of the frameworks and chromophores therein. The multiphoton upconversion performance can be intensified by pressure-related structural contraction. Over ten-fold increment in the 2PA active cross-section up to 2217 GM is achieved in pressed LIFM-114 compared with the 210 GM for pristine sample at 780 nm.

A Metal-Organic Supramolecular Box as a Universal Reservoir of UV, WL, and NIR Light for Long-Persistent Luminescence.

Long persistent luminescence (LPL) materials have a unique photophysical mechanism to store light radiation energy for subsequent release. However, in comparison to the common UV source, white-light (WL) and near-infrared (NIR) excited LPL is scarce. Herein we report a metal-organic supramolecular box based on a D-π-A-type ligand. Owing to the integrated one-photon absorption (OPA) and two-photon absorption (TPA) attributes of the ligand, the heavy-atom effect of the metal center, as well as π-stacking and J-aggregation states in the supramolecular assembly, LPL can be triggered by all wavebands from the UV to the NIR region. This novel designed supramolecular kit to afford LPL by both OPA and TPA pathways provides potential applications in anti-counterfeiting, camouflaging, decorating, and displaying, among others.

Photoluminescent Phosphinine Cu(I) Halide Complexes: Temperature Dependence of the Photophysical Properties and Applications as a Molecular Thermometer.

Luminescent thermometers have attracted much attention, because of their fast response, high sensitivity, and noninvasive operation, relative to other traditional thermometers. The extensive studies on the temperature-dependent luminescent properties of Cu(I) complexes make this low-cost metal source a promising candidate as a component of thermometers. Herein, we prepared three luminescent phosphinine Cu(I) complexes whose emission lifetimes are precisely dependent on the temperature variations. For practical utilization, sensor films have been fabricated by doping these Cu(I) complexes into the matrices of polyacrylamide. These films not only exhibit excellent linear correlations between the temperature and emission lifetime over the wide range of 77-337 K, but also show high sensitivity (with the best one to -6.99 µs K-1). These are essential factors for the application in luminescent molecular thermometers. Moreover, the emission mechanism for these Cu(I) complexes are rationalized by the combination of experimental and theoretical results.