Irisin reshapes bone metabolic homeostasis to delay age-related osteoporosis by regulating the multipotent differentiation of BMSCs via Wnt pathway.

Introduction: Bone aging is linked to changes in the lineage differentiation of bone marrow stem cells (BMSCs), which show a heightened tendency to differentiate into adipocytes instead of osteoblasts. The therapeutic potential of irisin in addressing age-related diseases has garnered significant attention. More significantly, irisin has the capacity to enhance bone mass recovery and sustain overall bone health.

Advances and Challenges in Speciation Measurement and Microkinetic Modeling for Gas-Solid Heterogeneous Catalysis.

Microkinetic modeling of heterogeneous catalysis serves as an efficient tool bridging atom-scale first-principles calculations and macroscale industrial reactor simulations. Fundamental understanding of the microkinetic mechanism relies on a combination of experimental and theoretical studies. This Perspective presents an overview of the latest progress of experimental and microkinetic modeling approaches applied to gas-solid catalytic kinetics.

Combining synchrotron vacuum-ultraviolet photoionization mass spectrometry and gas chromatography-mass spectrometry for isomer-specific mechanistic analysis with application to the benzyl self-reaction.

Elucidating the formation mechanism of polycyclic aromatic hydrocarbons (PAHs) is crucial to understand processes in the contexts of combustion, environmental science, astrochemistry, and nanomaterials synthesis. An excited electronic-state pathway has been proposed to account for the formation of 14π aromatic anthracene in the benzyl (b-CH) self-reaction. Here, to improve our understanding of anthracene formation, we investigate CH bimolecular reactions in a tubular SiC microreactor through an isomer-resolved method that combines in situ synchrotron-radiation VUV photoionization mass spectrometry and ex-situ gas chromatography-mass spectrometry.

Theoretical Study of Extensive Hydrogen Abstraction Reactions for 2-Hydroxyethylhydrazine (HEH).

Energetic ionic liquids have a high potential to replace the traditional monopropellant hydrazine as a high-energy green propellant and can be widely used in aerospace technology. A high-energy ionic liquid─HEHN has also gained extensive attention from researchers. To explore the reaction mechanism of HEHN and establish a chemical kinetic model for high-energy ionic liquid propellants, 28 hydrogen abstraction reactions of HEH, which is the main decomposition product of HEHN, were investigated in this study.

Co-Feeding CO for Methylfuran Aromatization over Bifunctional Zeolite-Supported ZnMoO.

Aromatization of biofuran offers promising approaches for sustainable biochemical production. However, this process is often hampered by low yields and severe coking on traditional zeolite catalysts. Herein, we report co-feeding CO for 2-methylfuran (MF) aromatization (CCMA) over bifunctional ZSM-5 supported ZnMoO.

Transferable and Interpretable Prediction of Site-Specific Dehydrogenation Reaction Rate Constants with NMR Spectra.

Accurate and efficient determination of site-specific reaction rate constants over a wide temperature range remains challenging, both experimentally and theoretically. Taking the dehydrogenation reaction as an example, our study addresses this issue by an innovative combination of machine learning techniques and cost-effective NMR spectra. Through descriptor screening, we identified a minimal set of NMR chemical shifts that can effectively determine reaction rate constants.

Unraveling Chain Branching in Cool Flames.

In cool flames, autoxidation of organic compounds forms alkyl hydroperoxides and ketohydroperoxides, and this controls the critical rate of chain branching, but there have been large uncertainties in the decomposition rate constants. We synthesized a series of hydroperoxides and measured their decomposition rate constants in pyrolysis experiments by spray-vaporization jet-stirred-reactor synchrotron vacuum ultraviolet photoionization mass spectrometry. Structural variation of the hydroperoxides, including alkyl, cycloalkyl, aromatic, and heterocyclic functionalities, has only a slight effect on their decomposition rate constants.

Probing the Reaction of Propargyl Radical with Molecular Oxygen by Synchrotron VUV Photoionization Mass Spectrometry.

Self-reaction of propargyl (CH) radical is the main pathway to benzene, the formation of which is the rate-controlling step toward the formation of polycyclic aromatic hydrocarbons (PAHs) and soot. Oxidation of CH is a promising strategy to inhibit the formation of hazardous PAHs and soot. In the present study, we studied the CH + O reaction from 650 to 1100 K in a laminar flow reactor and identified the intermediates and products by synchrotron VUV photoionization mass spectrometry.

Dimeric product formation in the self-reaction of small peroxy radicals using synchrotron radiation vacuum ultraviolet photoionization mass spectrometry.

Peroxy radicals (RO) are key reactive intermediates in atmospheric oxidation processes and yet their chemistry is not fully unraveled. Little is known about their structures and the structures of the dimeric products (ROOR) in the self-reaction of small RO, which are among the most abundant RO in the atmosphere. The product branching ratios of ROOR and their atmospheric roles are still in controversy.

Close Intimacy between PtIn Clusters and Zeolite Channels for Ultrastability toward Propane Dehydrogenation.

Propane dehydrogenation (PDH) serves as a pivotal intentional technique to produce propylene. The stability of PDH catalysts is generally restricted by the readsorption of propylene which can subsequently undergo side reactions for coke formation. Herein, we demonstrate an ultrastable PDH catalyst by encapsulating PtIn clusters within silicalite-1 which serves as an efficient promoter for olefin desorption.

Direct Observation of Covalently Bound Clusters in Resonantly Stabilized Radical Reactions and Implications for Carbonaceous Particle Growth.

Based on quantum mechanically guided experiments that observed elusive intermediates in the domain of inception that lies between large molecules and soot particles, we provide a new mechanism for the formation of carbonaceous particles from gas-phase molecular precursors. We investigated the clustering behavior of resonantly stabilized radicals (RSRs) and their interactions with unsaturated hydrocarbons through a combination of gas-phase reaction experiments and theoretical calculations. Our research directly observed a sequence of covalently bound clusters (CBCs) as key intermediates in the evolution from small RSRs, such as benzyl (CH), indenyl (CH), 1-methylnaphthyl (1-CH), and 2-methylnaphthyl (2-CH), to large polycyclic aromatic hydrocarbons (PAHs) consisting of 28 to 55 carbons.

Recycling Valuable Alkylbenzenes from Polystyrene through Methanol-Assisted Depolymerization.

The vast bulk of polystyrene (PS), a major type of plastic polymers, ends up in landfills, which takes up to thousands of years to decompose in nature. Chemical recycling promises to enable lower-energy pathways and minimal environmental impacts compared with traditional incineration and mechanical recycling. Herein, we demonstrated that methanol as a hydrogen supplier assisted the depolymerization of PS (denoted as PS-MAD) into alkylbenzenes over a heterogeneous catalyst composed of Ru nanoparticles on SiO.

The Importance of Sintering-Induced Grain Boundaries in Copper Catalysis to Improve Carbon-Carbon Coupling.

Syngas conversion serves as a gas-to-liquid technology to produce liquid fuels and valuable chemicals from coal, natural gas, or biomass. During syngas conversion, sintering is known to deactivate the catalyst owing to the loss of active surface area. However, the growth of nanoparticles might induce the formation of new active sites such as grain boundaries (GBs) which perform differently from the original nanoparticles.

Ni-Based Catalysts for CO Methanation: Exploring the Support Role in Structure-Activity Relationships.

The catalytic hydrogenation of CO to methane is one of the highly researched areas for the production of chemical fuels. The activity of catalyst is largely affected by support type and metal-support interaction deriving from the special method during catalyst preparation. Hence, we employed a simple solvothermal technique to synthesize Ni-based catalysts with different supports and studied the support role (CeO, AlO, ZrO, and LaO) on structure-activity relationships in CO methanation.

Dealuminated Beta zeolite reverses Ostwald ripening for durable copper nanoparticle catalysts.

Copper nanoparticle-based catalysts have been extensively applied in industry, but the nanoparticles tend to sinter into larger ones in the chemical atmospheres, which is detrimental to catalyst performance. In this work, we used dealuminated Beta zeolite to support copper nanoparticles (Cu/Beta-deAl) and showed that these particles become smaller in methanol vapor at 200°C, decreasing from ~5.6 to ~2.

The effects of mesenchymal stem cells-derived exosomes in rheumatoid arthritis: a review.

Rheumatoid arthritis (RA) is a most common chronic joint disease belonging to inflammatory autoimmune disease. The pathology of the disease is characterised by the infiltration and proliferation of fibroblast like synoviocytes (FLSs) and the destruction of the bone and cartilage matrix, which leads to joint dysfunction and even deformity.In recent years, an increasing number of studies have shown that MSCs have immunosuppressive properties and have been demonstrated in a variety of disease.

The mechanism of dendritic cell-T cell crosstalk in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterised by joint pain and swelling, synovial hyperplasia, cartilage damage, and bone destruction. The mechanisms of dendritic cell (DC) and T cell-mediated crosstalk have gradually become a focus of attention. DCs regulate the proliferation and differentiation of CD4 T cell subtypes through different cytokines, surface molecules, and antigen presentation.

Lattice oxygen-mediated electron tuning promotes electrochemical hydrogenation of acetonitrile on copper catalysts.

Copper is well-known to be selective to primary amines via electrocatalytic nitriles hydrogenation. However, the correlation between the local fine structure and catalytic selectivity is still illusive. Herein, we find that residual lattice oxygen in oxide-derived Cu nanowires (OD-Cu NWs) plays vital roles in boosting the acetonitrile electroreduction efficiency.

Elucidating the toluene formation mechanism in the reaction of propargyl radical with 1,3-butadiene.

Toluene is one of the simplest mono-substituted benzene derivatives and an important precursor to form polycyclic aromatic hydrocarbons (PAHs) and soot. However, there is a lack of critical understanding of the formation mechanisms of the toluene molecule. In this work, we explore high-temperature reactions of propargyl radical addition to 1,3-butadiene in a tubular flow microreactor.

Possible Future Avenues for Rheumatoid Arthritis Therapeutics: Hippo Pathway.

Rheumatoid arthritis (RA) is a persistent systemic autoimmune disease with the hallmarks of swelling of the joint, joint tenderness, and progressive joint destruction, which may cause synovial inflammation and pannus as a basic pathological change, resulting in joint malformations and serious disorders. At present, the precise etiology and mechanism of pathogenesis of RA are unknown. The imbalance of immune homeostasis is the origin of RA.

Elucidating the photodissociation fingerprint and quantifying the determination of organic hydroperoxides in gas-phase autoxidation.

Hydroperoxides are formed in the atmospheric oxidation of volatile organic compounds, in the combustion autoxidation of fuel, in the cold environment of the interstellar medium, and also in some catalytic reactions. They play crucial roles in the formation and aging of secondary organic aerosols and in fuel autoignition. However, the concentration of organic hydroperoxides is seldom measured, and typical estimates have large uncertainties.

Experimental and Updated Kinetic Modeling Study of Neopentane Low Temperature Oxidation.

Neopentane is an ideal fuel model to study low-temperature oxidation chemistry. The significant discrepancies between experimental data and simulations using the existing neopentane models indicate that an updated study of neopentane oxidation is needed. In this work, neopentane oxidation experiments are carried out using two jet-stirred reactors (JSRs) at 1 atm, at a residence time of 3 s, and at three different equivalence ratios of 0.

Role of formaldehyde in promoting aromatic selectivity during methanol conversion over gallium-modified zeolites.

Gallium-modified HZSM-5 zeolites are known to increase aromatic selectivity in methanol conversion. However, there are still disputes about the exact active sites and the aromatic formation mechanisms over Ga-modified zeolites. In this work, in situ synchrotron radiation photoionization mass spectrometry (SR-PIMS) experiments were carried out to study the behaviors of intermediates and products during methanol conversion over Ga-modified HZSM-5.