Metrnl: a promising biomarker and therapeutic target for cardiovascular and metabolic diseases.

Modern human society is burdened with the pandemic of cardiovascular and metabolic diseases. Metrnl is a widely distributed secreted protein in the body, involved in regulating glucose and lipid metabolism and maintaining cardiovascular system homeostasis. In this review, we present the predictive and therapeutic roles of Metrnl in various cardiovascular and metabolic diseases, including atherosclerosis, ischemic heart disease, cardiac remodeling, heart failure, hypertension, chemotherapy-induced myocardial injury, diabetes mellitus, and obesity.

One-pot conversion of xylose to 1,2-pentanediol catalyzed by an organic acid-assisted Pt/NC in aqueous phase.

The direct synthesis of 1,2-pentanediol (1,2-PeD) from renewable xylose and its derivatives derived from hemicellulose is appealing yet challenging due to its low selectivity for the target product. In this study, one-pot catalytic conversion of xylose to 1,2-PeD was performed by using nitrogen-doped carbon (NC) supported Pt catalysts with the assistance of organic acids. A remarkable yield of 49.3% for 1,2-PeD was achieved by reacting 0.1869 g xylose in 30 mL water at 200 °C under a hydrogen pressure of 3 MPa for 8 h in the presence of 0.1 g of 2.5Pt/NC600 catalyst and 0.1869 g propanoic acid co-catalyst. The presence of vicinal Pt-acid pair sites on the surface of the 2.5Pt/NC600 catalyst exhibited a synergistic effect in promoting the hydrogenation of furfural to furfuryl alcohol intermediate and subsequent hydrogenation and ring-opening reactions leading to the formation of 1,2-PeD. The addition of organic acids, may serve as both acid catalyst for dehydration of xylose and hydrogen donor for hydrogenation of furfural and furfuryl alcohol, thereby promoting the one-pot conversion of xylose to 1,2-PeD. Remarkably, the 2.5Pt/NC600 catalyst demonstrated outstanding catalytic performance and good reusability over five consecutive cycles without significant deactivation.

Selective conversion of carbon dioxide into heavy olefins over Ga modified delafossite-CuFeO2.

Ga-modified CuFeO2 used as an efficient catalyst for CO2 hydrogenation to heavy olefins (C=5+) can achieve a high heavy olefin selectivity of 53.5%, which lies at a high level among reported catalysts, at a single pass CO2 conversion of 41.5%. It also displays an excellent long-term stability over 100 h, exhibiting its promising potential for industrial applications.

A nitrogen-doped carbon nanotube confined CuCo nanoalloy catalyzing one-pot conversion of levulinic acid to 1,4-pentanediol.

Nitrogen-doped carbon nanotube confined CuCo nanoalloy catalysts are fabricated by using ZIF-67 as a sacrificial template for the one-pot selective hydrogenation of levulinic acid (LA) to 1,4-pentanediol (1,4-PDO). The optimal catalyst achieves a high 1,4-PDO yield of 87.8% at full LA conversion. It also exhibits good recycling stability and can be reused at least 5 times.

Conversion of cellulose into levulinic acid under the catalysis of Brønsted acidic ionic liquid and erbium chloride in water.

We propose a new approach for the synergistically catalytic conversion of cellulose to levulinic acid (LA) in water by SO3H-functionalized ionic liquid (SFIL) and lanthanide chloride (LnCl3). Compared with using 1-methyl-3-(3-sulfopropyl)imidazolium chloride ([MIMPS]Cl) only, the LA yield using [MIMPS]Cl and ErCl3 increased by 14.4% and 13.6% at 50 mol% of IL and 30 mol% of IL, respectively. Moreover, the combined [MIMPS]Cl and ErCl3 system can tolerate high concentrations of substrates and maintain high activity at eleven runs. We also investigated the effects of the cation structure of ionic liquids (alkyl chain length, hydroxyl groups on the side chains, and aromatic properties) on LA production. The observations can provide useful information for designing efficient ionic liquid catalysts for biomass utilization.

Direct Production of 2,5-Dimethylfuran with High Yield from Fructose over a Carbon-Based Solid Acid-Coated CuCo Bimetallic Catalyst.

A carbon-based solid acid, which functionalized with p-toluenesulfonic acid (TsOH), an encapsulated non-noble CuCo multifunctional heterogeneous catalyst was for the first time developed and used to catalyze the one-pot direct conversion of fructose into 2,5-dimethylfuran (2,5-DMF) without purification of 5-hydroxymethylfurfural (5-HMF) from the reaction solutions. Fructose was first transformed into intermediate 5-HMF over the outer shell carbon-based solid acid sites via dehydration, and subsequently 5-HMF was further converted to produce 2,5-DMF over the non-noble metal active sites in the core. As high as 71.1 mol % yield of 2,5-DMF was achieved in tetrahydrofuran at 220 °C and 3 MPa H2 for 10 h, which is higher than the yield reported for the direct conversion of fructose to 2,5-DMF. Besides, the carbon-based solid acid-coated CuCo catalyst could be reused up to five times.

Catalytic dehydration of fructose to 5-hydroxymethylfurfural over Nb2O5 catalyst in organic solvent.

The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) in DMSO was performed over Nb2O5 derived from calcination of niobic acid at various temperatures (300-700 °C). The catalysts were characterized by powder X-ray diffraction, N2 physical adsorption, temperature-programed desorption of NH3, n-butylamine titration using Hammett indicators, infrared spectroscopy of adsorbed pyridine, and X-ray photoelectron spectroscopy. It was found that both catalytic activity and surface acid sites decrease with increasing calcination temperatures. The Nb2O5 derived from calcination of niobic acid at 400 °C reveals the maximum yield of HMF among all the catalysts, although the amount of acid sites on the catalyst is lower than that on the sample calcined at 300 °C. The results suggest that the presence of larger amounts of strong acid sites on the surface of the Nb2O5 calcined at 300 °C may promote side reactions. The Nb2O5 prepared at 400 °C shows 100% fructose conversion with 86.2% HMF yield in DMSO at 120 °C after 2 h. The activity of the catalyst decreases gradually during recycle because of coke deposition; however, it can be fully recovered by calcination at 400 °C for 2 h, suggesting that this catalyst is of significance for practical applications.

Dehydration of fructose to 5-hydroxymethylfurfural by rare earth metal trifluoromethanesulfonates in organic solvents.

The catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF) was investigated by using various rare earth metal trifluoromethanesulfonates, that is, Yb(OTf)(3), Sc(OTf)(3), Ho(OTf)(3), Sm(OTf)(3), Nd(OTf)(3) as catalysts in DMSO. It is found that the catalytic activity increases with decreasing ionic radius of rare earth metal cations. Among the examined catalysts, Sc(OTf)(3) exhibits the highest catalytic activity. Fructose conversion of 100% and a HMF yield of 83.3% are obtained at 120°C after 2h by using Sc(OTf)(3) as the catalyst. Moreover, the catalytic dehydration of fructose was also carried out in different solvents, for example, DMA, 1,4-dioxane, and a mixture of PEG-400 and water. The results show that among the solvents DMSO is the most efficient in promoting the dehydration of fructose to HMF, and no rehydration byproducts such as levulinic acid and formic acid are detected.

Synthesis of ZrO2 nanowires by ionic-liquid route.

Zirconia precursor nanowires were synthesized via the solvothermal reaction of zirconium tetra-n-propoxide Zr(OPr(n))(4) with ethylene glycol and 1-butyl-3-methyl imidazolium tetrafluoroborate ionic liquid at 160 degrees C. The as-synthesized nanowires were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), thermogravimetric and differential scanning calorimetric (TG-DSC) analysis, and infrared spectroscopy (IR), etc. The length of the as-synthesized nanowires reaches approximately 20 mum, and the width approximately 50 nm, giving an aspect ratio of a few hundreds. Upon calcination at elevated temperatures, the zirconia precursor nanowires transform from relative dense structure into highly porous ZrO(2) nanowires consisting of interconnected nanocrystallites; in addition the length of the nanowires is greatly reduced. Cyclic voltammetry measurement shows that the modification of the graphite electrode with the ZrO(2) nanowires greatly enhances sensitivity of the detection of vanadium, suggesting that ZrO(2) nanowires may find important applications in vanadium(V) determination using electroanalytical methods with chemically modified electrode technique.

In situ source-template-interface reaction route to hollow ZrO(2) microspheres with mesoporous shells.

Hollow ZrO(2) microspheres with mesoporous shells have been synthesized by a novel hydrothermal reaction of zirconium oxychloride in the presence of urea, hydrochloric acid, and ethanol. The morphology and shell thickness of the hollow microspheres can be controlled by varying synthesis conditions. After calcination at high temperature, the morphologies of the hollow microspheres are essentially preserved. Pt catalyst supported on the hollow calcined ZrO(2) microspheres exhibits more excellent catalytic performance in CO oxidation than those on ZrO(2) powders derived from conventional precipitation methods.

Novel ionic liquid assisted synthesis of SnO2 microspheres.

Tin oxide (SnO2) microspheres with an average 2.5 microm in diameters have been successfully synthesized through a rapid hydrothermal process heating by microwave in the presence of an ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate. X-ray diffraction, scanning electron microscopy and transmission electron microscopy are used to characterize the morphology and crystalline structure of the microspheres. The as-synthesized SnO2 microspheres exhibit a tetragonal rutile structure. The mechanism of the microspheres formation is proposed.