YTHDC1 inhibits autophagy-dependent NF-κB signaling by stabilizing Beclin1 mRNA in macrophages.

BACKGROUND: YTHDC1, a key m(6)A nuclear reader, plays a crucial role in regulating mRNA splicing, export, and stability. However, the functional significance and regulatory mechanisms of YTHDC1 in inflammatory bowel disease (IBD) remain to be explored. METHODS: We established a dextran sulfate sodium (DSS)-induced murine colitis model in vivo and LPS/IFN-γ-stimulated macrophage inflammation in vitro. The expression of YTHDC1 was determined. Colocalization of YTHDC1 and macrophages was assayed by immunofluorescence staining. LV-YTHDC1 or shYTHDC1 lentiviruses were applied for YTHDC1 overexpression or inhibition. For NF-κB inhibition, JSH-23 was utilized. The interaction of YTHDC1 and Beclin1 mRNA was determined by RIP, and the m6A modification of Beclin1 was confirmed by MeRIP. RESULTS: In DSS-induced colitis and LPS/IFN-γ-treated RAW264.7 macrophages, we observed a significant downregulation of YTHDC1. Overexpression of YTHDC1 resulted in decreased levels of iNOS, CD86, and IL-6 mRNA, along with inhibited NF-κB activation in LPS/IFN-γ-treated RAW264.7 cells. Conversely, downregulation of YTHDC1 promoted iNOS expression and inhibited autophagy. Additionally, the effect of YTHDC1 knockdown on CD86 and IL-6 mRNA induced by LPS/IFN-γ was abolished by the NF-κB inhibitor JSH-23. Mechanistically, YTHDC1 interacted with Beclin1 mRNA, thereby stabilizing Beclin1 mRNA and enhancing Beclin1 expression and autophagy. These effects ultimately led to the inhibition of NF-κB signaling in LPS/IFN-γ-challenged macrophages. CONCLUSIONS: YTHDC1 inhibited the macrophage-mediated inflammatory response by stabilizing Beclin1 mRNA, which may be a potential therapeutic target for the treatment of IBD.

NHC-Au-Catalyzed Isomerization of Propargylic B(MIDA)s to Allenes and Double Isomerization of Alkynes to 1,3-Dienes.

The synthesis of allenyl boronates is an important yet challenging topic in organic synthesis. Reported herein is an NHC-gold-catalyzed 1,3-H shift toward allenyl boronates synthesis from simple propargylic B(MIDA)s. Mechanistic studies suggest dual roles of the boryl moiety in the reaction: to activate the substrate for isomerization and at the same time, to prevent the allene product from further isomerization. These effects should be a result of α-anion stabilization and α-cation destabilization conferred by the B(MIDA) moiety, respectively. The NHC-Au catalyst, which is commercially available, is also found to be reactive in alkyne-to-1,3-diene isomerization reactions in an atom-economic and base-free manner.

Correction to "Facile Synthesis of Vertically Arranged CNTs for Efficient Solar-Driven Interfacial Water Evaporation".

[This corrects the article DOI: 10.1021/acsomega.2c06706.].

General Synthesis of N-CF3 Heteroaryl Amides via Successive Fluorination and Acylation of Sterically Hindered Isothiocyanates.

We report the one-pot synthesis of N-CF3 heteroaryl amides (NTFMHA) from heteroaryl carboxylic acids and sterically hindered isothiocyanates, including various amino acid analogues, in the presence of AgF. The key to this reaction is the utilization of free heteroaryl acyl chlorides, rather than their corresponding hydrochloride salts. This method represents a complementary method of our previous work and enables modification to a variety of previously inaccessible structures, including α-tertiary amines and N-CF3-modified pharmaceuticals.

Regioselective Electrophilic Addition to Propargylic B(MIDA)s Enabled by ß-Boron Effect.

Electrophilic addition reaction to alkynes is of fundamental importance in organic chemistry, yet the regiocontrol when reacting with unsymmetrical 1,2-dialkyl substituted alkynes is often problematic. Herein, it is demonstrated that the rarely recognized ß-boron effect can confer a high level of site-selectivity in several alkyne electrophilic addition reactions. A broad range of highly functionalized and complex organoborons are thus formed under simple reaction conditions starting from propargylic MIDA (N-methyliminodiacetic acid) boronates. These products are demonstrated to be valuable building blocks in organic synthesis. In addition to the regiocontrol, this study also observes a drastic rate enhancement upon B(MIDA) substitution. Theoretical calculation reveals that the highest occupied molecular obital (HOMO) energy level of propargylic B(MIDA) is significantly raised by 0.3 eV, and the preferential electrophilic addition to the γ position is due to its higher HOMO orbital coefficient and more negative natural bond orbital (NBO) charge compared to the ß position. This study demonstrates the potential of utilizing the ß-boron effect in stereoelectronic control of chemical transformations, which can inspire further research in this area.

Simultaneous photothermal and photocatalytic MOF- derived C/TiO2 composites for high-efficiency solar driven purification of sewage.

Solar-driven water evaporation is a promising technology of freshwater production to address the water scarcity. However, the photothermal material and the distilled water would be contaminated in the evaporation of wastewater including organic pollutants. In this work, MOF-derived C/TiO2 composites (carbonized UiO-66-NH2 (Ti)) with simultaneous photothermal and photocatalytic functions are designed for producing freshwater from sewage. With advantageous features of porous structure with large specific area, excellent sunlight absorption and super-hydrophilicity, the carbonized UiO-66-NH2 (Ti) layer exhibits high water evaporation efficiency of 94% under 1.0 sun irradiation. Meanwhile, the layer can simultaneously decompose the organic pollutants with degradation efficiency of 92.7% in the underlying water during solar-driven water evaporation. This bifunctional material will provide a new approach for solar-driven water evaporation and photocatalytic degradation of organic pollutant synergistically.

Stereoselective Synthesis of Amphoteric α-Haloalkenyl Boronates by Halogenative Semipinacol Rearrangement of B(MIDA)-Propargylic Alcohols.

The facile synthesis of stereo-defined and transformable functionality-enriched building blocks is of great importance in modern organic chemistry, as it allows the rapid and divergent assembly of complex molecules. Herein a halogen electrophile (N-bromosuccinimide and N-iodosuccinimide) initiated semipinacol rearrangement reaction of B(MIDA)-propargylic alcohols (MIDA=N-methyliminodiacetyl) by aryl migration towards the synthesis of amphoteric α-haloalkenyl boronates in moderate to good yields with excellent stereoselectivities is reported. The value of the products is evidenced by their ability to undergo divergent conversions to polysubstituted alkenes through manipulation of the C-B and C-X (X=Br, I) bonds and the carbonyl group.

Grafting of Maleic Anhydride onto Poly(vinylidene fluoride) Using Reactive Extrusion.

Poly(vinylidene fluoride) was grafted with maleic anhydride through reactive extrusion by using diisopropyl benzene peroxide as an initiator and 9-vinyl anthracene as a stabilizer. Effects of various parameters on grafting degree were investigated including the amounts of monomer, initiator and stabilizer. The maximum extent of grafting achieved was 0.74%. The graft polymers were characterized using FTIR, water contact angle, thermal, mechanical and XRD studies. Improved hydrophilic and mechanical properties were observed for graft polymers.

Enhanced in-plane thermal conductivity of polyimide-based composites via in situ interfacial modification of graphene.

Interfacial thermal resistance is the main barrier restricting the heat dissipation of thermal management materials in electronic equipment. The interface structure formed by covalent bonding is an effective way to promote interfacial heat transfer. Herein, an integrated composite with multi-aspect covalent bonding beneficial for heat transmission is constructed by polyimide (PI) polymerization with maleimide modified graphene nanosheets (M@GNS). The interfacial structure with low thermal resistance built by covalent bonding and oriented graphene arrangement initiated by the coating process makes the in-plane thermal conductivity of the composite as high as 16.10 W m-1 K-1. Finite element simulation and 1000 bending tests are carried out to further verify the performance advantages of the integrated structure in the internal thermal diffusion and long-term use of the composite. M@GNS/PI with integrated structure provides extra heat transfer channels for heat dissipation, possibly providing an effective way to address the traditional thermal accumulation issue of electronic devices.

Pyrrolidinium-Based Hyperbranched Anion Exchange Membranes with Controllable Microphase Separated Morphology for Alkaline Fuel Cells.

It is well acknowledged that the microphase-separated morphology of anion exchange membranes (AEMs) is of vital importance for membrane properties utilized in alkaline fuel cells. Herein, a rigid macromolecule poly(methyldiallylamine) (PMDA) is incorporated to regulate the microphase morphology of hyperbranched AEMs. As expected, the hyperbranched poly(vinylbenzyl chloride) (HB-PVBC) is guided to distribute along PMDA chains, and longer PMDA cha leads to a more distinct microphase morphology with interconnected ionic channels. Consequently, high chloride conductivity of 10.49 mS cm-1 at 30 °C and suppressed water swelling ratio lower than 30% at 80 °C are obtained. Furthermore, the ß-H of pyrrolidinium cations in the non-antiperiplanar position increases the energy barrier of ß-H elimination, leading to conformationally disfavored Hofmann elimination and increased alkaline stability. This strategy is anticipated to provide a feasible way for preparing hyperbranched AEMs with clear microphase morphology and good overall properties for alkaline fuel cells.

Facile Synthesis of Vertically Arranged CNTs for Efficient Solar-Driven Interfacial Water Evaporation.

Solar-driven evaporation of water is a sustainable and promising technology for addressing the crisis of clean water. Herein, novel vertically arranged carbon nanotube (V-CNT) aerogels with a tree branch structure is facilely synthesized through an ice templating method. The V-CNT-based photothermal evaporator exhibits efficient broadband light trapping and super-hydrophilicity. Owing to the unique structure and ultrafast water transportation, a high evaporation rate of 3.26 kg m-2 h-1 was achieved by the three-dimensional V-CNT-based evaporator under a solar illumination of 1 kW m-2. More significantly, the V-CNT shows excellent recycling stability and salt-resistant performance in seawater and may provide a novel strategy to the practical sustainable technique of water purification applications.

Glutathione-depletion reinforced enzyme catalytic activity for photothermal assisted bacterial killing by hollow mesoporous CuO.

The emergence and prevalence of drug-resistant bacteria caused by the overuse of antibiotics pose new challenges to the treatment of bacterial infections. In this work, hollow mesoporous CuO nanozymes (HM-CuO nanozymes) as excellent antibacterial agents were prepared by a template method. The synthesized HM-CuO nanozymes exhibit peroxidase-like catalytic activity, which can efficiently catalyze H2O2 to generate toxic reactive oxygen species (ROS), causing fatal damage to bacteria. Moreover, the hyperthermia of HM-CuO produced by photothermal therapy (PTT) not only effectively kills bacteria but also enhances the catalytic activity of nanozymes and produces more ROS. Moreover, the HM-CuO nanozymes have a glutathione (GSH)-depleting function to effectively consume GSH in bacteria and generate Cu(I) with higher catalytic effect, which can significantly improve the sterilization effect and produce a 100% inhibitory rate against E. coli and S. aureus. Overall, the HM-CuO nanozymes with strong peroxidase-like catalytic activity, excellent photothermal performance and GSH consumption ability offer a promising synergistic strategy for clinical bacterial infection.

Design of Interconnected Carbon Fiber Thermal Management Composites with Effective EMI Shielding Activity.

Heat dissipation efficiency and electromagnetic interference (EMI) shielding performance are vital to integration, miniaturization, and application of electronic devices. Flexible and designable polymer-based composites are promising candidates but suffer from unavoidable interfacial thermal resistances, anisotropic thermal conductivity, and low shielding of EMI limiting application. Herein, multifunctional epoxy resin (EP)-based composites with an interconnected carbon fibers (CFs) network structure containing a low thermal resistance interfacial were prepared by high-temperature calcination and infiltration. The coherent heat and electron transfer pathways constructed with self-oriented CFs cloth connected by carbon nanotubes (CNTs) converted from leaf-shaped zeolitic imidazolate frameworks (ZIF-L) and stable magnetic property provided by cobalt nanoparticles contained in the CNTs made composites to an integrated in-plane thermal conductivity of up to 7.50 W m-1 K-1, a through-plane thermal conductivity of 1.96 W m-1 K-1, and an EMI shielding effectiveness of 38.4 dB. Furthermore, the mechanical properties of CFs and the junction effect of CNTs endowed the composites with stability of mechanical property, thermal conductivity, and EMI shielding effectiveness after multiple bendings. The finite element simulation further verified the advantage of CFs network linked by CNTs on heat transfer. This work provides the desired design for the construction of a multifunctional polymer-based composite used in advanced electronic equipment.

Boryl-Dictated Site-Selective Intermolecular Allylic and Propargylic C-H Amination.

For internal alkenes possessing two or more sets of electronically and sterically similar allylic protons, the site-selectivity for allylic C-H functionalization is fundamentally challenging. Previously, the negative inductive effect from an electronegative atom has been demonstrated to be effective for several inspiring regioselective C-H functionalization reactions. Yet, the use of an electropositive atom for a similar purpose remains to be developed. α-Aminoboronic acids and their derivatives have found widespread applications. Their current syntheses rely heavily on functional group manipulations. Herein we report a boryl-directed intermolecular C-H amination of allyl N-methyliminodiacetyl boronates (B(MIDA)s) and propargylic B(MIDA)s to give α-amino boronates with an exceptionally high level of site-selectivities (up to 300:1). A wide variety of highly functionalized secondary and tertiary α-amino boronates are formed in generally good to excellent yields, thanks to the mildness of the reaction conditions. The unsaturated double and triple bonds within the product leave room for further decorations. Mechanistic studies reveal that the key stabilization effect of the B(MIDA) moiety on its adjacent developing positive charge is responsible for the high site-selectivity and that a closed transition state might be involved, as the reaction is fully stereoretentive. An activation effect of B(MIDA) is also found.

Negatively Charged MOF-Based Composite Anion Exchange Membrane with High Cation Selectivity and Permeability.

Every metal and metallurgical industry is associated with the generation of wastewater, influencing the living and non-living environment, which is alarming to environmentalists. The strict regulations about the dismissal of acid and metal into the environment and the increasing emphasis on the recycling/reuse of these effluents after proper remedy have focused the research community's curiosity in developing distinctive approaches for the recovery of acid and metals from industrial wastewaters. This study reports the synthesis of UiO-66-(COOH)2 using dual ligand in water as a green solvent. Then, the prepared MOF nanoparticles were introduced into the DMAM quaternized QPPO matrix through a straightforward blending approach. Four defect-free UiO-66-(COOH)2/QPPO MMMs were prepared with four different MOF structures. The BET characterization of UiO-66-(COOH)2 nanoparticles with a highly crystalline structure and sub-nanometer pore size (~7 Å) was confirmed by XRD. Because of the introduction of MOF nanoparticles with an electrostatic interaction and pore size screening effect, a separation coefficient (SHCl/FeCl2) of 565 and UHCl of 0.0089 m·h-1 for U-C(60)/QPPO were perceived when the loading dosage of the MOF content was 10 wt%. The obtained results showed that the prepared defect-free MOF membrane has broad prospects in acid recovery applications.

In-situ fabrication of metal oxide nanocaps based on biphasic reactions with surface nanodroplets.

HYPOTHESIS: Surface-bound nanomaterials are widely used in clean energy techniques from solar-driven evaporation in desalination to hydrogen production by photocatalytic electrolysis. Reactive surface nanodroplets may potentially streamline the process of fabrication of a range of surface-bound nanomaterials invoking biphasic reactions at interfaces. EXPERIMENTS: In this work, we demonstrate the feasibility of reactive surface nanodroplets for in situ synthesis and anchoring of nanocaps of metal oxides with tailored porous structures. FINDINGS: Spatial arrangement and surface coverage of nanocaps are predetermined during the formation of nanodroplets, while the crystalline structures of metal oxides can be controlled by thermal treatment of organometallic nanodroplets produced from the biphasic reactions. Notably, tuning the ratio of reactive and nonreactive components in surface nanodroplets enables the formation of porous nanocaps that can double photocatalytic efficiency in the degradation of organic contaminants in water, compared to smooth nanocaps. In total, we demonstrate in situ fabrication of four types of metal oxides in the shape of nanocaps. Our work shows that reactive surface nanodroplets may open the door to a general, fast and tuneable route for preparing surface-bound materials. This fabrication approach may develop new nanomaterials needed for photocatalytic reactions, wastewater treatment, optical focusing, solar energy conversion and other clean energy techniques.

Poly(1,5-diaminonaphthalene)-Grafted Monolithic 3D Hierarchical Carbon as Highly Capacitive and Stable Supercapacitor Electrodes.

A holistic approach to fabricate a hierarchical electrode that consists of redox-active poly(1,5-diaminonaphthalene), 1,5 PDAN, uniformly and conformally grafted onto a 3D carbon nanotube (CNT-a-CC) electrode is set forth. The CNT-a-CC electrode was formed by direct growth of high-density CNTs on the surface of every individual microfiber, the constituent of activated carbon cloth (a-CC). Owing to the naphthalene backbone, conformal deposition of 1,5 PDAN on carbon surfaces has been readily attained via electropolymerization. This hierarchical platform with open and continuous nanochannels formed by CNTs coupled with excellent electrical connectivity between CNTs and the polymer provides a reproducible platform for electrochemical investigation. According to multiple sample analyses on CNT-a-CC, the gravimetric capacitance of 1,5 PDAN is up to 1250 F/g, and this value can be maintained up to 100 mV/s. Hierarchical organization provides a specific capacitance of 650 F/g at 2 mV/s at a 1,5 PDAN loading of 2.5 mg/cm2. The conjugated ladder structure of the polymer led to strong π-π interactions between the polymer and CNT-a-CC together with mechanically robust CNT-a-CC. A capacitance retention of 94% for 1,5 PDAN has been obtained after 25,000 cycles at 100 mV/s, a significant cycle stability improvement over conventional conductive polymers such as polyaniline. This new lightweight electrode that seamlessly integrates functional species with nanochannel-like CNT-a-CC opens up a new opportunity to harness electrochemical reactions in the 3D carbon electrode for energy storage and electrocatalysis as well as electrochemical sensing.

Interfacial Modulation of Graphene by Polythiophene with Controlled Molecular Weight to Enhance Thermal Conductivity.

With a trend of continuing improvement in the development of electronic devices, a problem of serious heat accumulation has emerged which has created the need for more efficient thermal management. Graphene sheets (GNS) have drawn much attention with regard to heat transfer because of their excellent in-plane thermal conductivity; however, the ultrahigh interfacial thermal resistance between graphene lamellae has seriously restricted its practical applications. Herein, we describe heat transfer membranes composed of graphene which have been modified by intrinsic thermally conductive polymers with different molecular weights. The presence of macromolecular surface modifiers not only constructed the graphene heat transfer interface by π-π interactions, but also significantly enhanced the membranes' in-plane thermal conductivity by utilizing their intrinsic heat transfer properties. Such results indicated that the in-plane thermal conductivity of the fabricated membrane exhibits a high in-plane thermal conductivity of 4.17 W m-1 K-1, which, containing the GNS modified with 6000 g/mol (Mn) of poly(3-hexylthiophene) (P3HT), was 26 times higher that of poly (vinylidene fluoride) (PVDF). The P3HT molecular chain with specific molecular weight can form more matching structure π-π interactions, which promotes thermal conductivity. The investigation of different molecular weights has provided a new pathway for designing effective interfacial structures to relieve interface thermal resistance in thermally conductive membranes.

Propelling microdroplets generated and sustained by liquid-liquid phase separation in confined spaces.

Flow transport in confined spaces is ubiquitous in technological processes, ranging from separation and purification of pharmaceutical ingredients by microporous membranes and drug delivery in biomedical treatment to chemical and biomass conversion in catalyst-packed reactors and carbon dioxide sequestration. In this work, we suggest a distinct pathway for enhanced liquid transport in a confined space via propelling microdroplets. These microdroplets can form spontaneously from localized liquid-liquid phase separation as a ternary mixture is diluted by a diffusing poor solvent. High speed images reveal how the microdroplets grow, break up and propel rapidly along the solid surface, with a maximal velocity up to ∼160 µm s-1, in response to a sharp concentration gradient resulting from phase separation. The microdroplet propulsion induces a replenishing flow between the walls of the confined space towards the location of phase separation, which in turn drives the mixture out of equilibrium and leads to a repeating cascade of events. Our findings on the complex and rich phenomena of propelling droplets suggest an effective approach to enhanced flow motion of multicomponent liquid mixtures within confined spaces for time effective separation and smart transport processes.

External oxidant-compatible phosphorus(III)-directed site-selective C-H carbonylation.

The first development of an external oxidant-compatible system involving a phosphorus(III)-directed C-H functionalization has been uncovered. An efficient C-H esterification of indoles with CO and alcohols has been reported in which the high reactivity and the exclusive C7-selectivity derives from the selection of a P(III)-directing group and the utilization of benzoquinone as an external oxidant with palladium catalysis. This strategy shows many advantages, involving an easily accessible and removable directing group, the use of cheap carbonylation sources, a broad substrate scope, and excellent positional selectivity. Two cyclopalladated intermediates were confirmed by x-ray analysis, uncovering key mechanistic features of this P(III)-directed C-H metalation event.