Sustainable Catalytic Transformation of Biomass-Derived 5-Hydroxymethylfurfural to 2,5-Bis(hydroxymethyl)tetrahydrofuran.

5-Hydroxymethylfurfural (5-HMF), one of the most important platform molecules in biorefinery, can be directly obtained from a vast diversity of biomass materials. Owing to the reactive functional groups (-CHO and -CH2 OH) in the structure, this versatile building block undertakes several transformations to provide a wealth of high value-added products. Among numerous well-established paradigms, the catalytic hydrogenation of 5-HMF towards 2,5-bis(hydroxymethyl)tetrahydrofuran (BHMTHF) is of great interest because this downstream diol can be exploited in a wide range of industrial applications. Not surprisingly, incessant endeavors from both academia and industry to upgrade this catalytic process have been established over the years. The main aim of this Review was to provide a comprehensive overview on the development of heterogeneous metal catalysts for the 5-HMF-to-BHMTHF transformation. Herein, the rational design and utility of hydrogenating catalysts were elaborated in many aspects including metal types (Ni, Co, Pd, Ru, Pt, and bimetals), solid supports, preparation method, recyclability, operating conditions, and reaction regime (batch and continuous flow). In addition, the assessment of cooperative catalysts to convert carbohydrates into BHMTHF under one-pot cascade, tentative mechanism, as well as prospects and challenges for the chemo-selective hydrogenation of 5-HMF were also highlighted.

Efficient Production of Adipic Acid by a Two-Step Catalytic Reaction of Biomass-Derived 2,5-Furandicarboxylic Acid.

Efficient catalytic ring-opening coupled with hydrogenation is a promising but challenging reaction for producing adipic acid (AA) from 2,5-furan dicarboxylic acid (FDCA). In this study, AA synthesis is carried out in two steps from FDCA via tetrahydrofuran-2,5-dicarboxylic acid (THFDCA) over a recyclable Ru/Al2 O3 and an ionic liquid, [MIM(CH2 )4 SO3 H]I (MIM=methylimidazolium) to deliver 99 % overall yield of AA. Ru/Al2 O3 is found to be an efficient catalyst for hydrogenation and hydrogenolysis of FDCA to deliver THFDCA and 2-hydroxyadipic acid (HAA), respectively, where ruthenium is more economically viable than well-known palladium or rhodium hydrogenation catalysts. H2 chemisorption shows that the alumina phase strongly affects the interaction between Ru nanoparticles (NPs) and supports, resulting in materials with high dispersion and small size of Ru NPs, which in turn are responsible for the high conversion of FDCA. An ionic liquid system, [MIM(CH2 )4 SO3 H]I is applied to the hydrogenolysis of THFDCA for AA production. The [MIM(CH2 )4 SO3 H]I exhibits superior activity, enables simple product isolation with high purity, and reduces the severe corrosion problems caused by the conventional hydroiodic acid catalytic system.

Clinical Relevance of C4d Deposition in Pediatric Immunoglobulin A Nephropathy.

INTRODUCTION: Few studies have reported the association between the complement cascade and pediatric immunoglobulin A nephropathy (IgAN). This study aimed to investigate the association between C4d staining positivity and the clinical/histopathological characteristics of pediatric patients with IgAN. METHODS: Children diagnosed with IgAN through renal biopsy were retrospectively reviewed. Renal biopsy specimens were stained using C4d immunohistochemistry. RESULTS: Among the 56 patients, 31 (55.4%) showed positive mesangial or peripheral capillary C4d staining in glomeruli. Urine protein-to-creatinine ratio was significantly higher in C4d-positive patients (p = 0.001). The severity of mesangial proliferation according to the Haas and Oxford classification was positively associated with positive C4d staining (p < 0.001). CONCLUSION: Positive C4d staining was found to be significantly associated with the clinical/histopathological severity of IgAN.

The Immune Responses and Calcification of Bioprostheses in the α1,3-Galactosyltransferase Knockout Mouse.

BACKGROUND: The study aim was to evaluate the immune reaction, difference of degenerative calcification, and anti-calcification effect of decellularization with or without α-galactosidase in bovine pericardium and porcine heart valves, using an α1,3-galactosyltransferase (α-Gal) knockout (KO) mouse model. METHODS: In order to elucidate the anti-calcification effect of decellularization with or without α-galactosidase, bovine pericardium and porcine heart valve tissues were assigned to four groups according to the tissue preparation method: (i) glutaraldehyde (GA) fixation only; (ii) decellularization + GA fixation (Decell); (iii) α-galactosidase + GA fixation (α-galactosidase); and (iv) decellularization +α-galactosidase + GA fixation (Decell + α-galactosidase). Each prepared tissue was implanted subcutaneously into α-Gal KO mice. Anti-α-Gal immunoglobulin (Ig) G and IgM antibody titers were monitored prior to implantation and at four, eight and 12 weeks after implantation using an enzyme-linked immunosorbent assay. Calcium contents of explanted tissues were measured at 12 weeks after implantation. RESULTS: There were no significant differences in the anti-α-Gal IgG antibody titers according to the type of bioprosthetic material or tissue preparation method (p >0.05). The calcium content was significantly lower in porcine heart valves than in bovine pericardium when implanted in α-Gal-KO mice (p <0.001). Calcium contents in bovine pericardium and porcine heart valves were significantly lower in the Decell, α-galactosidase and Decell + α-galactosidase groups than in the GA group (all p <0.05). CONCLUSIONS: The porcine heart valve induced lower levels of calcium deposition than did the bovine pericardium, but the anti-α-Gal IgG antibody titers did not differ significantly between the bioprosthetic tissues. Decellularization had significant anticalcification effects in both the bovine pericardium and porcine heart valves, though there was no significant difference in the anti-α-Gal IgG antibody titers among tissue preparation methods.