UV-Assisted Room-Temperature Fabrication of Lignin-Based Nanosilver Complexes for Photothermal-Mediated Sterilization

Green and controllable preparation of silver nanoparticles (AgNPs) remains a great challenge. In this work, ethanol-extracted lignin-based nanosilver composites (AgNPs@EL) were synthesized at room temperature with the assistance of ultraviolet (UV) radiation. The ethanol-extracted lignin (EL) could serve as natural dispersion carriers and reducing agents for AgNPs. The reducing ability of EL could be further improved under UV irradiation, which enables the rapid synthesis of AgNPs at room temperature. More importantly, due to the good photothermal conversion capacity of EL, AgNPs@EL exhibits remarkably enhanced photothermal performance and excellent photothermal antibacterial ability, which could cause 7.2 and 5.3 log10 CFU/mL reduction against Escherichia coli and Staphylococcus aureus, respectively, under near-infrared (NIR) irradiation (808 nm, 1.8 W/cm2) for 5 min. Furthermore, the composite film obtained by impregnating bacterial cellulose onto AgNPs@EL solution also shows significantly improved mechanical properties and photothermal antimicrobial activity. Therefore, this work may provide insights into the design of lignin-based photothermal-mediated antimicrobial materials

Lipase-Catalyzed One-Step and Regioselective Synthesis of Clindamycin Palmitate

Chemical synthesis of clindamycin palmitate, a prodrug with taste greatly improved more than that of clindamycin, involves laborious steps of protection and deprotection to achieve the monoacylation only at 2-hydroxyl group of clindamycin and gives an overall yield below 50%. Here we report the first example of one-step synthesis of clindamycin palmitate with high regioselectivity using immobilized Candida antarctica lipase B (Novozym 435) as the catalyst. The lipase-catalyzed synthesis reached a conversion above 90% in 12 h using toluene as solvent and, moreover, a highly regioselective acylation at the 2-hydroxyl of clindamycin. The significantly improved conversion achieved at an excellent regioselectivity makes this enzymatic process attractive for the synthesis of clindamycin ester derivatives

Construction of Macroporous β‑Glucosidase@MOFs by a Metal Competitive Coordination and Oxidation Strategy for Efficient Cellulose Conversion at 120 °C

Metal–organic frameworks (MOFs) have become promising accommodation for enzyme immobilization in recent years. However, the microporous nature of MOFs affects the accessibility of large molecules, resulting in a significant decline in biocatalysis efficiency. Herein, a novel strategy is reported to construct macroporous MOFs by metal competitive coordination and oxidation with induced defect structure using a transition metal (Fe2+) as a functional site. The feasibility of in situ encapsulating β-glucosidase (β-G) within the developed macroporous MOFs endows an enzyme complex (β-G@MOF-Fe) with remarkably enhanced synergistic catalysis ability. The 24 h hydrolysis rate of β-G@MOF-Fe (with respect to cellobiose) is as high as approximately 99.8%, almost 32.2 times that of free β-G (3.1%). Especially, the macromolecular cellulose conversion rate of β-G@MOF-Fe reached 90% at 64 h, while that of β-G@MOFs (most micropores) was only 50%. This improvement resulting from the expansion of pores (significantly increased at 50–100 nm) can provide enough space for the hosted biomacromolecules and accelerate the diffusion rate of reactants. Furthermore, unexpectedly, the constructed β-G@MOF-Fe showed a superior heat resistance of up to 120 °C, attributing to the new strong coordination bond (Fe2+–N) formation through the metal competitive coordination. Therefore, this study offers new insights to solve the problem of the high-temperature macromolecular substrate encountered in the actual reaction

Rational Design of Antifouling Polymeric Nanocomposite for Sustainable Fluoride Removal from NOM-Rich Water

The presence of natural organic matter (NOM) exerts adverse effects on adsorptive removal of various pollutants including fluoride from water. Herein, we designed a novel nanocomposite adsorbent for preferable and sustainable defluoridation from NOM-rich water. The nanocomposite (HZO@HCA) is obtained by encapsulating hydrous zirconium oxide nanoparticles (HZO NPs) inside hyper-cross-linked polystyrene anion exchanger (HCA) binding tertiary amine groups. Another commercially available nanocomposite HZO@D201, with the host of a cross-linked polystyrene anion exchanger (D201) binding ammonium groups, was involved for comparison. HZO@HCA features with abundant micropores instead of meso-/macropores of HZO@D201, resulting in the inaccessible sites for NOM due to the size exclusion. Also, the tertiary amine groups of HCA favor an efficient desorption of the slightly loaded NOM from HZO@HCA. As expected, Sigma-Aldrich humic acid even at 20 mg of DOC/L did not exert any observable effect on fluoride sequestration by HZO@HCA, whereas a significant inhibition was observed for HZO@D201. Cyclic adsorption runs further verified the superior reusability of HZO@HCA for defluoridation from NOM-rich water. In addition, the HZO@HCA column could generate ∼80 bed volume (BV) effluent from a synthetic fluoride-containing groundwater to meet the drinking water standard (<1.5 mg F/L), whereas HCA and HZO@D201 columns could only generate <5 and ∼40 BV effluents, respectively. This study is believed to shed new light on how to rationally design antifouling nanocomposites for water remediation

Odds ratios and 95% confidence interval for NAFLD, metabolic syndrome, and its components according to quartile (Q) of serum uric acid.

<p>Model 1 was adjusted for age smoking, and drinking;</p><p>Model 2 was further adjusted for BMI;</p><p>Model 3 was further adjusted for HOMA-IR and C-reactive protein;</p><p>Model 4 was further adjusted for serum creatinine and alanine aminotransferase;</p><p>Model 5 was further adjusted for the components of metabolic syndrome (variables as categories).</p>*<p>Fully adjusted model without component itself.</p><p>Serum levels of HOMA-IR, C-reactive protein, creatinine and alanine aminotransferase were log transformed.</p><p>Abbreviation: BP, blood pressure; NAFLD, nonalcoholic fatty liver disease.</p

Characteristics of participants according to quartile (Q) of serum uric acid (n = 1440).

<p>Data are means ± SE or raw numbers (%). Continuous data were used for univariate general linear models and categorical data were analyzed by χ² tests.</p><p>Abbreviation: ALT, alanine aminotransferase; BMI, body mass index; LDL-C, serum low-density lipoprotein cholesterol; HDL-C, serum high-density lipoprotein cholesterol; HOMA-IR, homeostasis model assessment of insulin resistance; NAFLD, nonalcoholic fatty liver disease.</p

Odds ratios (OR) and 95% confidence interval (CI) for NAFLD.

<p>Adjusted for age, smoking, drinking, BMI, HOMA-IR, C-reactive protein, creatinine and alanine aminotransferase The black and white circles are the ORs for NAFLD among subjects with or without MetS (A), central obesity (B), and hypertriglyceridemia (C) respectively. The error bars indicate the 95% CI of OR, and broken lines indicate the OR = 1. Serum levels of HOMA-IR, C-reactive protein, creatinine and alanine aminotransferase were log transformed.</p

Multiple linear regression analysis of the logarithm of serum uric acid.

<p>The squares are the standardized regression coefficients (β) and the error bars indicate the 95% CI of β, and broken lines indicate the β coefficients = 0. Genomic variants were coded as dummy variables: 0 for homozygosity for wild-type alleles, 1 for heterozygosity, and 2 for homozygosity for effect alleles.</p