Superior Charge Transport in Ni-Diamine Conductive MOFs.

Two-dimensional conductive metal-organic frameworks (2D cMOFs) are an emerging class of crystalline van der Waals layered materials with tunable porosity and high electrical conductivity. They have been used in a variety of applications, such as energy storage and conversion, chemiresistive sensing, and quantum information. Although designing new conductive 2D cMOFs and studying their composition/structure-property relationships have attracted significant attention, there are still very few examples of 2D cMOFs that exhibit room-temperature electrical conductivity above 1 S cm-1, the value exhibited by activated carbon, a well-known porous and conductive material that serves in myriad applications. When such high conductivities are achieved, Ni-diamine linkages are often involved, yet Ni-diamine MOFs remain difficult to access. Here, we report two new 2D cMOFs made through ortho-diamine connections: M3(HITT)2 (M = Ni, Cu; HITT = 2,3,7,8,12,13-hexaiminotetraazanaphthotetraphene). The electrical conductivity of Ni3(HITT)2 reaches 4.5 S cm-1 at 298 K, whereas the conductivity of Cu3(HITT)2 spans from 0.05 (2Cu+Cu2+) to 10-6 (3Cu2+) upon air oxidation, much lower than that of Ni3(HITT)2. Spectroscopic analysis reveals that Ni3(HITT)2 exhibits significantly stronger in-plane π-d conjugation and higher density of charge carriers compared to Cu3(HITT)2, accounting for the higher electrical conductivity of Ni3(HITT)2. Cu2+/Cu+ mixed valency modulates the energy level and carrier density of Cu3(HITT)2, allowing for a variation of electrical conductivity over 4 orders of magnitude. This work provides a deeper understanding of the influence of metal nodes on electrical conductivity and confirms ortho-diamine linkers as privileged among ligands for 2D cMOFs.

Arresting dissolution of two-dimensional metal-organic frameworks enables long life in electrochemical devices.

Two-dimensional conjugated metal-organic frameworks (2D cMOFs) are emerging as promising materials for electrochemical energy storage (EES). Despite considerable interest, an understanding of their electrochemical stability and the factors contributing to their degradation during cycling is largely lacking. Here we investigate three Cu-based MOFs and report that the dissolution of 2D cMOFs into electrolytes is a prevalent and significant degradation pathway. Several factors, such as the inherent solubility of ligands in electrolyte solvents and the duration of charge-discharge cycling exert a strong influence on the dissolution process. When these factors combine within a MOF, severely limited cycling stability is observed, with dissolution accounting for up to 80% of capacity degradation. Conversely, excellent cycling stability is observed when testing a Cu-MOF with a sparingly soluble ligand within an optimized potential window. Overall, these findings represent essential insights into the electrochemical stability of 2D cMOFs, offering crucial guidelines for their targeted development in EES applications.

Ovatodiolide inhibited hepatocellular carcinoma stemness through SP1/MTDH/STAT3 signaling pathway.

Hepatocellular carcinoma (HCC) is characterized with high recurrence and mortality, and the clinical treatments for HCC are very limited. Hepatocellular carcinoma stem cells are the root of HCC progress, recurrence, and multidrug resistance. Ovatodiolide (OVA) is a bioactive diterpenoid served as an inflammatory and immunotherapeutic responses modulator. In this research, we found OVA inhibited HCC stemness through inhibiting MTDH gene transcription. Moreover, we firstly discovered transcription factor SP1 bound to the promoter region of MTDH to transcriptionally regulate MTDH level. Mechanically, we demonstrated OVA decreased SP1 protein stability to transcriptionally inhibit MTDH gene, and inhibited the nuclear translocation of p65, and then diminished IL-6 level to suppress JAK/STAT3 signaling pathway, eventually decreases CD133 level and the stemness of HCC. Furthermore, we demonstrated ACT004, OVA derivative with high metabolic stability towards cytochrome P450 enzymes, showed no genotoxicity and no accumulative or delayed toxicities after long-term administration in rats. And the in vivo efficacy experiments indicated ACT004 inhibited tumor growth of hepatocellular carcinoma. In conclusion, we revealed the mechanism of OVA in regulating HCC stemness, detected the toxicity of OVA derivative and evaluated the in vivo efficacy which lays a foundation for further discovery of anti-HCC stem cell agents and provide a new strategy for the application of OVA in clinical treatment.

Rapid screening of acetylcholinesterase active contaminants in water: A solid phase microextraction-based ligand fishing approach.

Effect-directed analysis (EDA) has been increasingly used for screening toxic contaminants in the environment, but conventional EDA procedures are often time-consuming and labor-extensive. This challenges the use of EDA for toxicant identification in the scenarios when quick answers are demanded. Herein, a solid phase microextraction ligand fishing (SPME-LF) strategy has been proposed as a rapid EDA approach for identifying acetylcholinesterase (AChE) active compounds in water. The feasibility of ligand fishing techniques for screening AChE active chemicals from environmental mixtures was first verified by a membrane separation method. Then, SPME fibers were prepared through self-assembly of boronic acid groups with AChE via co-bonding and applied for SPME-LF. As AChE coated SPME fibers selectively enriched AChE-active compounds from water, comparing sorbing compounds by the SPME fibers with and without AChE coating can quickly distinguish AChE toxicants in mixtures. Compared with conventional EDA, SPME-LF does not require repeating sample separations and bioassays, endowing SPME-LF with the merits of low-cost, labor-saving, and user-friendly. It is believed that cost-efficient and easy-to-use SPME-LF strategy can potentially be a rapid EDA method for screening receptor-specific toxicants in aquatic environment, especially applicable in time-sensitive screening.

A Layered Organic Cathode for High-Energy, Fast-Charging, and Long-Lasting Li-Ion Batteries.

Eliminating the use of critical metals in cathode materials can accelerate global adoption of rechargeable lithium-ion batteries. Organic cathode materials, derived entirely from earth-abundant elements, are in principle ideal alternatives but have not yet challenged inorganic cathodes due to poor conductivity, low practical storage capacity, or poor cyclability. Here, we describe a layered organic electrode material whose high electrical conductivity, high storage capacity, and complete insolubility enable reversible intercalation of Li+ ions, allowing it to compete at the electrode level, in all relevant metrics, with inorganic-based lithium-ion battery cathodes. Our optimized cathode stores 306 mAh g-1cathode, delivers an energy density of 765 Wh kg-1cathode, higher than most cobalt-based cathodes, and can charge-discharge in as little as 6 min. These results demonstrate the operational competitiveness of sustainable organic electrode materials in practical batteries.

Enterovirus 71 leads to abnormal mitochondrial dynamics in human neuroblastoma SK-N-SH cells.

EV71, a significant pathogen causing hand-foot-mouth disease, is associated with severe neurological complications such as brain stem encephalitis, aseptic meningitis, and acute flaccid paralysis. While the role of mitochondrial dynamics in regulating the replication of numerous viruses is recognized, its specific involvement in EV71 remains unclear. This study aimed to elucidate the role of mitochondrial dynamics in human neuroblastoma SK-N-SH cells during EV71 infection. Utilizing laser confocal microscopy and transmission electron microscopy, we observed that EV71 infection induced mitochondrial elongation and damage to cristae structures, concurrently accelerating mitochondrial movement. Furthermore, we identified the reduction in the expression of dynamin-related protein 1 (Drp1) and optic atrophy protein 1 (Opa1) and the increased expression of Mitofusion 2 (Mfn2) upon EV71 infection. Notably, EV71 directly stimulated the generation of mitochondrial reactive oxygen species (ROS), leading to a decline in mitochondrial membrane potential and ATP levels. Remarkably, the application of melatonin, a potent mitochondrial protector, inhibited EV71 replication by restoring Drp1 expression. These findings collectively indicate that EV71 induces alterations in mitochondrial morphology and dynamics within SK-N-SH cells, potentially impairing mitochondrial function and contributing to nervous system dysfunction. The restoration of proper mitochondrial dynamics may hold promise as a prospective approach to counteract EV71 infection.

Synthesis of melampomagnolide B derivatives as potential anti-Triple Negative Breast Cancer agents.

Triple-negative breast cancer (TNBC) is the most malignant and aggressive subtype of breast cancer. Currently, the treatment options to TNBC are limited and the discovery of new drugs and novel therapeutic strategies for treatment of TNBC is urgently needed. In this study, a series of melampomagnolide B (MMB) derivatives were designed, synthesized, and evaluated for their anti-TNBC activities. Compound 7 and 13a showed highly potent activity against different TNBC cells with IC50 values ranging from 0.37 µM to 1.52 µM, which demonstrated 3.6- to 54-fold improvement comparing to the parent compound MMB. The phenotypic effect revealed that compound 7 and 13a could inhibit metastasis, induce apoptosis and arrest cell cycle distribution of TNBC cells. Furthermore, the mechanism research indicated compounds 7 and 13a bound IKKß and inhibited the IKKß-mediated phosphorylation of IκB and p65, then inhibited the nuclear translocation of p65 and eventually regulated the genes related to metastasis, apoptosis and cell cycle under NF-κB control. Moreover, compound 7 inhibited the tumor growth in vivo, and the weights of spleens and livers were also reduced compared with control group which indicated that compound 7 could inhibit metastasis of TNBC in vivo. These findings indicate that compound 7 may be used as a promising lead compound for ultimate discovery of anti-TNBC drug.

Electrically conductive [Fe4S4]-based organometallic polymers.

Tailoring the molecular components of hybrid organic-inorganic materials enables precise control over their electronic properties. Designing electrically conductive coordination materials, e.g. metal-organic frameworks (MOFs), has relied on single-metal nodes because the metal-oxo clusters present in the vast majority of MOFs are not suitable for electrical conduction due to their localized electron orbitals. Therefore, the development of metal-cluster nodes with delocalized bonding would greatly expand the structural and electrochemical tunability of conductive materials. Whereas the cuboidal [Fe4S4] cluster is a ubiquitous cofactor for electron transport in biological systems, few electrically conductive artificial materials employ the [Fe4S4] cluster as a building unit due to the lack of suitable bridging linkers. In this work, we bridge the [Fe4S4] clusters with ditopic N-heterocyclic carbene (NHC) linkers through charge-delocalized Fe-C bonds that enhance electronic communication between the clusters. [Fe4S4Cl2(ditopic NHC)] exhibits a high electrical conductivity of 1 mS cm-1 at 25 °C, surpassing the conductivity of related but less covalent materials. These results highlight that synthetic control over individual bonds is critical to the design of long-range behavior in semiconductors.

XB130 inhibits healing of diabetic skin ulcers through the PI3K/Akt signalling pathway.

BACKGROUND: Diabetic skin ulcers, a significant global healthcare burden, are mainly caused by the inhibition of cell proliferation and impaired angiogenesis. XB130 is an adaptor protein that regulates cell proliferation and migration. However, the role of XB130 in the development of diabetic skin ulcers remains unclear. AIM: To investigate whether XB130 can regulate the inhibition of proliferation and vascular damage induced by high glucose. Additionally, we aim to determine whether XB130 is involved in the healing process of diabetic skin ulcers, along with its molecular mechanisms. METHODS: We conducted RNA-sequencing analysis to identify the key genes involved in diabetic skin ulcers. We investigated the effects of XB130 on wound healing using histological analyses. In addition, we used reverse transcription-quantitative polymerase chain reaction, Western blot, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, immunofluorescence, wound healing, and tubule formation experiments to investigate their effects on cellular processes in human umbilical vein endothelial cells (HUVECs) stimulated with high glucose. Finally, we performed functional analysis to elucidate the molecular mechanisms underlying diabetic skin ulcers. RESULTS: RNA-sequencing analysis showed that the expression of XB130 was up-regulated in the tissues of diabetic skin ulcers. Knockdown of XB130 promoted the healing of skin wounds in mice, leading to an accelerated wound healing process and shortened wound healing time. At the cellular level, knockdown of XB130 alleviated high glucose-induced inhibition of cell proliferation and angiogenic impairment in HUVECs. Inhibition of the PI3K/Akt pathway removed the proliferative effects and endothelial protection mediated by XB130. CONCLUSION: The findings of this study indicated that the expression of XB130 is up-regulated in high glucose-stimulated diabetic skin ulcers and HUVECs. Knockdown of XB130 promotes cell proliferation and angiogenesis via the PI3K/Akt signalling pathway, which accelerates the healing of diabetic skin ulcers.

Low Latency TOE with Double-Queue Structure for 10Gbps Ethernet on FPGA.

The TCP protocol is a connection-oriented and reliable transport layer communication protocol which is widely used in network communication. With the rapid development and popular application of data center networks, high-throughput, low-latency, and multi-session network data processing has become an immediate need for network devices. If only a traditional software protocol stack is used for processing, it will occupy a large amount of CPU resources and affect network performance. To address the above issues, this paper proposes a double-queue storage structure for a 10G TCP/IP hardware offload engine based on FPGA. Furthermore, a TOE reception transmission delay theoretical analysis model for interaction with the application layer is proposed, so that the TOE can dynamically select the transmission channel based on the interaction results. After board-level verification, the TOE supports 1024 TCP sessions with a reception rate of 9.5 Gbps and a minimum transmission latency of 600 ns. When the TCP packet payload length is 1024 bytes, the latency performance of TOE's double-queue storage structure improves by at least 55.3% compared to other hardware implementation approaches. When compared with software implementation approaches, the latency performance of TOE is only 3.2% of the software approaches.

Reversible O-O Bond Scission and O2 Evolution at MOF-Supported Tetramanganese Clusters.

The scission of the O-O bond in O2 during respiration and the formation of the O-O bond during photosynthesis are the engines of aerobic life. Likewise, the reduction of O2 and the oxidation of reduced oxygen species to form O2 are indispensable components for emerging renewable technologies, including energy storage and conversion, yet discrete molecule-like systems that promote these fundamental reactions are rare. Herein, we report a square-planar tetramanganese cluster formed by self-assembly within a metal-organic framework that reversibly reduces O2 by four electrons, facilitating the interconversion between molecular O2 and metal-oxo species. The tetranuclear cluster spontaneously cleaves the O-O bond of O2 at room temperature to generate a tetramanganese-bis(µ2-oxo) species, which, in turn, is competent for O-O bond reformation and O2 evolution at elevated temperatures, enabled by the head-to-head orientation of two oxo species. This study demonstrates the viability of four-electron interconversion between molecular O2 and metal-oxo species and highlights the importance of site isolation for achieving multi-electron chemistry at polynuclear metal clusters.

Cytotoxic Terpenes from the Flowers of Inula japonica against Human Hepatocarcinoma Cells.

Two new 1,10-seco-eudesmanolides (1 and 2) were isolated from the flowers of Inula japonica together with two eudesmanolide analogs (3 and 4) and two monoterpene derivatives (5 and 6). Their structures were established on the basis of detailed spectroscopic analyses and electronic circular dichroism data. All isolates were evaluated for their antiproliferative activities against human hepatocarcinoma HepG2 and SMMC-7721 cells. Japonipene B (3) exhibited the most potent effect with the IC50 values of 14.60±1.62 and 22.06±1.34 µM against HepG2 and SMMC-7721 cells, respectively. Furthermore, japonipene B (3) showed significant efficacies of arresting the cell cycle at the S/G2-M stages, inducing mitochondria-mediated apoptosis, and inhibiting cell migration in HepG2 cells.

TREM2 as a Potential Immune-Related Biomarker of Prognosis in Patients with Skin Cutaneous Melanoma Microenvironment.

Background: The skin cutaneous melanoma (SKCM) is a devastating form of skin cancer triggered by genetic and environmental factors, and the incidence of SKCM has rapidly increased in recent years. Immune infiltration of the tumor microenvironment is positively associated with overall survival in many tumors. Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor of the immunoglobulin superfamily and a crucial signaling hub for multiple pathological pathways that mediate immunity. Although numerous evidences suggest a crucial role for TREM2 in tumorigenesis of some tumors, no systematic SKCM analysis of TREM2 is available. Mehods. The relationship between TREM2 expression and diagnostic and prognostic value of SKCM patients via using The Cancer Genome Atlas (TCGA) data. The expression level of TREM2 and clinical characteristic correlation in SKCM patients were assessed by the Wilcoxon rank sum test. The cox regression methods, Kaplan-Meier (KM), and log-rank test were used to assess the impact of TREM2 expression on the overall survival (OS). Furthermore, the Gene Set Enrichment Analysis (GSEA) and TIMER were performed to evaluate the enrichment pathways and potential functions and quantify the immune cell infiltration level for TREM2 expression. Results: The TREM2 in SKCM sample expression levels was significantly higher than in normal tissues. Moreover, this expression level of TREM2 was also associated with the BMI of SKCM patients. KM overall survival analysis and OS curve displayed that a high-level TREM2 expression was significantly correlated with a better SKCM prognosis of patients as compared with a low level of TREM2 expression. The GSEA analysis also revealed that TREM2 was associated with immune functions, such as neutrophil activation. Conclusion: TREM2 played a crucial role in SKCM, which might be a prognostic biomarker and correlated with immune infifiltrates in SKCM patients.

Dipole-mediated exciton management strategy enabled by reticular chemistry.

Selectively blocking undesirable exciton transfer pathways is crucial for utilizing exciton conversion processes that involve participation of multiple chromophores. This is particularly challenging for solid-state systems, where the chromophores are fixed in close proximity. For instance, the low efficiency of solid-state triplet-triplet upconversion calls for inhibiting the parasitic singlet back-transfer without blocking the flow of triplet excitons. Here, we present a reticular chemistry strategy that inhibits the resonance energy transfer of singlet excitons. Within a pillared layer metal-organic framework (MOF), pyrene-based singlet donors are situated perpendicular to porphyrin-based acceptors. High resolution transmission electron microscopy and electron diffraction enable direct visualization of the structural relationship between donor and acceptor (D-A) chromophores within the MOF. Time-resolved photoluminescence measurements reveal that the structural and symmetry features of the MOF reduce the donor-to-acceptor singlet transfer efficiency to less than 36% compared to around 96% in the control sample, where the relative orientation of the donor and acceptor chromophores cannot be controlled.

Room-Temperature Quantitative Quantum Sensing of Lithium Ions with a Radical-Embedded Metal-Organic Framework.

Recent advancements in quantum sensing have sparked transformative detection technologies with high sensitivity, precision, and spatial resolution. Owing to their atomic-level tunability, molecular qubits and ensembles thereof are promising candidates for sensing chemical analytes. Here, we show quantum sensing of lithium ions in solution at room temperature with an ensemble of organic radicals integrated in a microporous metal-organic framework (MOF). The organic radicals exhibit electron spin coherence and microwave addressability at room temperature, thus behaving as qubits. The high surface area of the MOF promotes accessibility of the guest analytes to the organic qubits, enabling unambiguous identification of lithium ions and quantitative measurement of their concentration through relaxometric and hyperfine spectroscopic methods based on electron paramagnetic resonance (EPR) spectroscopy. The sensing principle presented in this work is applicable to other metal ions with nonzero nuclear spin.

Pyrogallate-Based Metal-Organic Framework with a Two-Dimensional Secondary Building Unit.

We report a metal-organic framework (MOF) with a rare two-dimensional (2D) secondary building unit (SBU). The SBU comprises mixed-valent Fe2+ and Fe3+ metal ions bridged by oxygen atoms pertaining to the polytopic ligand 3,3',4,4',5,5'-hexahydroxybiphenyl, which also define the iron-oxide 2D layers. Overall, the anionic framework exhibits rare topology and evidences strong electronic communication between the mixed-valence iron sites. These results highlight the importance of dimensionality control of MOF SBUs for discovering new topologies in reticular chemistry, and especially for improving electronic communication within the MOF skeleton.

Thousand-fold increase in O2 electroreduction rates with conductive MOFs.

Molecular materials must deliver high current densities to be competitive with traditional heterogeneous catalysts. Despite their high density of active sites, it has been unclear why the reported O2 reduction reaction (ORR) activity of molecularly defined conductive metal-organic frameworks (MOFs) have been very low: ca. -1 mA cm-2. Here, we use a combination of gas diffusion electrolyses and nanoelectrochemical measurements to lift multiscale O2 transport limitations and show that the intrinsic electrocatalytic ORR activity of a model 2D conductive MOF, Ni3(HITP)2, has been underestimated by at least 3 orders of magnitude. When it is supported on a gas diffusion electrode (GDE), Ni3(HITP)2 can deliver ORR activities >-150 mA cm-2 and gravimetric H2O2 electrosynthesis rates exceeding or on par with those of prior heterogeneous electrocatalysts. Enforcing the fastest accessible mass transport rates using scanning electrochemical cell microscopy revealed that Ni3(HITP)2 is capable of ORR current densities exceeding -1200 mA cm-2 and at least another 130-fold higher ORR mass activity than has been observed in GDEs. Our results directly implicate precise control over multiscale mass transport to achieve high-current-density electrocatalysis in molecular materials.

Porous lanthanide metal-organic frameworks with metallic conductivity.

Metallic charge transport and porosity appear almost mutually exclusive. Whereas metals demand large numbers of free carriers and must have minimal impurities and lattice vibrations to avoid charge scattering, the voids in porous materials limit the carrier concentration, provide ample space for impurities, and create more charge-scattering vibrations due to the size and flexibility of the lattice. No microporous material has been conclusively shown to behave as a metal. Here, we demonstrate that single crystals of the porous metal-organic framework Ln1.5(2,3,6,7,10,11-hexaoxytriphenylene) (Ln = La, Nd) are metallic. The materials display the highest room-temperature conductivities of all porous materials, reaching values above 1,000 S/cm. Single crystals of the compounds additionally show clear temperature-deactivated charge transport, a hallmark of a metallic material. Lastly, a structural transition consistent with charge density wave ordering, present only in metals and rare in any materials, provides additional conclusive proof of the metallic nature of the materials. Our results provide an example of a metal with porosity intrinsic to its structure. We anticipate that the combination of porosity and chemical tunability that these materials possess will provide a unique handle toward controlling the unconventional states that lie within them, such as charge density waves that we observed, or perhaps superconductivity.

Probe Synthesis Reveals Eukaryotic Translation Elongation Factor†1 Alpha†1 as the Anti-Pancreatic Cancer Target of BE-43547A2.

The natural product, BE-43547A2 , decreases pancreatic cancer cell stemness. However, its anticancer molecular mechanisms have not been fully established. Based on structure-activity relationships of BE-43547A2 , we synthesized a probe and investigated its potential targets using an in situ click reaction. We found that BE-43547A2 exerts its anticancer effects by covalently binding the cysteine234 (C234) residue of eukaryotic translation elongation factor 1 alpha 1 (eEF1A1). This binding mode was confirmed by a series of experiments including a xenograft mouse model. We also determined that eEF1A1 plays an important role in regulating pancreatic cancer cell stemness. Analyses of 99 clinical pancreatic cancer samples revealed that eEF1A1 expressions are closely correlated with clinicopathological grade and patient survival. In conclusion, eEF1A1 is involved in pancreatic cancer progression and is therefore, a promising novel covalent target for pancreatic cancer treatment.