Tungstate-Catalyzed Bioinspired Decarboxylative Halogenation of Electron-Deficient (Hetero)Phenolic Acids

Phenolic acids (PAs) can be derived from lignin, and their value-added transformations provide a good renewable source for arenes. The halogenase-catalyzed decarboxylative halogenation of PAs is a key step in the biosynthesis of many halogenated natural products. Inspired by halogenase, herein we present a synthetically useful tungstate-catalyzed decarboxylative halogenation of electron-deficient (hetero)­phenolic acids under mild conditions, based on which the antibiotic bromophene and its analogues were prepared concisely. Mechanism studies support the halogenation–decarboxylation procedure, but the decarboxylation–halogenation pathway cannot be excluded. Additionally, the chloride can reverse the selectivity between bromination and iodination in this reaction, somehow providing a useful perspective for the halide selectivity in vanadium-dependent haloperoxidase in seawater

Reviving the Potential of Vermiculite-Based Adsorbents: Exceptional Ibuprofen Removal on Novel Amide-Containing Gemini Surfactants

In this study, we introduce a novel series of gemini surfactants with amide groups (HDAB, HDAHD, and HDAPX) and use these surfactants to decorate sodium vermiculite (Na-Vt) for the adsorption of Ibuprofen (IBP) from wastewater. Exceptional IBP uptake on organo-vermiculites (organo-Vts) is obtained, with maximum adsorption capacities reaching 249.87, 342.21, and 460.15 mg/g for HDAB-Vt, HDAHD-Vt, and HDAPX-Vt (C0 = 500 mg/L, modifier dosage = 0.2 CEC), respectively. The adsorption of IBP is well fitted by pseudo-second-order, intraparticle diffusion, and Freundlich isotherm models, verifying chemical adsorption processes with multilayer arrangement of IBP in organo-Vts. Thermodynamically, the removal of IBP on HDAHD-Vt is exothermic, while the endothermic nature aptly describes the adsorption process of HDAB-Vt and HDAPX-Vt. Moreover, organo-Vts can be stably regenerated in three cycles. Outstanding adsorption performance of organo-Vts is attributed to synergistic effects of the partition process and functional interaction, which are influenced by the steric hindrance and chain configuration of the modifier. A combined evaluation of adsorption tests and fitting calculations is employed to reveal the adsorption mechanism: (i) the incorporation of amides into the alkyl chain significantly enhances the utilization of the interlayer space in organo-Vts. (ii) Smaller steric hindrance and higher rigidity of the modifier spacer contribute to improved adsorption performance. The findings in this study rekindle interest in Vt-based adsorbents, which demonstrate comparable potential to other emerging adsorbents that are yet to be fully explored

Data_Sheet_1_Exploring the Relationship Between Learning Goal Orientation and Knowledge-Sharing Among Information Communication Technology Consultants: The Role of Incentive Schemes.docx

Knowledge sharing (KS) is critical for consulting companies to develop sustainable competitive advantages. While the importance of KS in the information communication technology (ICT) sector has been proved, the assumed linear relationships in KS mechanisms are confronted with KS dilemmas: consultants’ intention to maximize personal gains from KS resulting in restrained KS efforts, for fear of losing value after sharing knowledge with colleagues. Drawing on motivation theory and goal orientation perspective, this study examines the roles of learning goal orientation (LGO) and incentive schemes in KS among ICT consultants. The multiple regression analyses of 389 consultants’ responses from 14 Chinese and 8 Korean ICT consulting companies demonstrated an inverted U-shape relationship between LGO and knowledge sharing; incentive schemes moderate this relationship. The findings shed light on the knowledge-sharing dilemma, with theoretical implications to research regarding goal-orientation, knowledge sharing, and managerial practices about the motivation and incentives of ICT consultants.</p

Redox signaling and antioxidant therapies in acute respiratory distress syndrome: a systematic review and meta-analysis

Objectives: No pharmacologic treatment that targets the pathophysiologic alterations of acute respiratory distress syndrome (ARDS) has proven effective. Previous studies have revealed overactive oxidative stress as a potential therapeutic target. Thus we conducted this systematic review to assess the efficacyof antioxidant therapy on the clinical outcomes of ARDS patients. Methods: We retrieved clinical trials from electronic databases. Articles and conference abstracts about antioxidant therapies for patients with ARDS were identified in which the overall effect of each antioxidant therapy on the mortality of ARDS patients was summarized. Results: We identified 18 relevant studies that met the inclusion criteria, including 899 patients in the experimental group and 870 patients in the control group. The pooled results indicated that most antioxidant therapies could not improve all-cause mortality and might even be harmful in ARDS patients at low risk of death. Conclusion: Unclassified patients could not benefit from the antioxidant therapies, and thus discretion must be exercised when using these therapies. Abbreviations ARDS: Acute respiratory distress syndrome; ICU: Intensive care unit; NAC: N-acetylcysteine; ROS: Reactive oxygen species; RNS: Reactive nitrogen species; RR: Relative risk; CI: Confidence interval; OTC: L-2-oxothiazolidine-4-carboxylic acid; EPA: Eicosapentaenoic acid; DHA: Docosahexaenoic acid; GLA: Gamma-linolenic acid; NA: Not applicable; PaO2/FiO2 ratio: The ratio of partial pressure arterial oxygen and fraction of inspired oxygen; ALI: Acute lung injury.</p

Discrete Miktoarm Star Block Copolymers with Tailored Molecular Architecture

Molecular architecture is a critical factor in regulating phase behaviors of the block copolymer and prompting the formation of unconventional nanostructures. This work meticulously designed a library of isomeric miktoarm star polymers with an architectural evolution from the linear-branched block copolymer to the miktoarm star block copolymer and to the star-like block copolymer (i.e., 3AB → 3(AB1)B2 → 3(AB)). All of the polymers have precise chemical composition and uniform chain length, eliminating inherent molecular uncertainties such as chain length distribution or architectural defects. The self-assembly behaviors were systematically studied and compared. Gradually increasing the relative length of the branched B1 block regulates the ratio between the bridge and loop configuration and effectively releases packing frustration in the formation of the spherical or cylindrical structures, leading to a substantial deflection of phase boundaries. Complex structures, such as Frank–Kasper phases, were captured at a surprisingly higher volume fraction. Rationally regulating the molecular architecture offers rich possibilities to tune the packing symmetry of block copolymers

Internalization Mechanism of Phenylboronic-Acid-Decorated Nanoplatform for Enhanced Nasal Insulin Delivery

Insulin injection causes great pain to the patient, and nasal mucosal administration of insulin is a novel route for the treatment of diabetes. This strategy could protect insulin from either extensive first-pass metabolism or enzyme degradation in the gastrointestinal tract. With the dynamic boronate esters reversibly formed by phenylboronic acid and diols on nasal mucosal epithelial cell surfaces, we herein developed phenylboronic-acid-functionalized dextran nanoplatforms to enhance the permeability of cargos and boost penetration. The nanoplatforms with excellent loading capacity exhibited significant endocytosis compared with naked insulin. The mechanism of endocytosis was involved in clathrin- and lipid raft/caveolae-dependent endocytic pathways. The in vivo nasal delivery of insulin suggested that these nanoplatforms did not trigger nasal epithelial inflammation and greatly decreased blood sugar levels and improved insulin bioavailability. Collectively, this proof-of-concept study demonstrates a novel carrier of phenylboronic-acid-decorated polymer for insulin delivery and provides a promising approach for the development of a diabetes therapeutic strategy

Effect of Porosity Parameters and Surface Chemistry on Carbon Dioxide Adsorption in Sulfur-Doped Porous Carbons

In this work, a series of highly porous sulfur-doped carbons are prepared through physical activation methods by using polythiophene as a precursor. The morphology, structure, and physicochemical properties are revealed by a variety of characterization methods, such as scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and nitrogen sorption measurement. Their porosity parameters and chemical compositions can be well-tuned by changing the activating agents (steam and carbon dioxide) and reaction temperature. These sulfur-doped porous carbons possess specific surface area of 670–2210 m² g^–1, total pore volume of 0.31–1.26 cm³ g^–1, and sulfur content of 0.6–4.9 atom %. The effect of porosity parameters and surface chemistry on carbon dioxide adsorption in sulfur-doped porous carbons is studied in detail. After a careful analysis of carbon dioxide uptake at different temperatures (273 and 293 K), pore volumes from small pore size (less than 1 nm) play an important role in carbon dioxide adsorption at 273 K, whereas surface chemistry is the key factor at a higher adsorption temperature or lower relative pressure. Furthermore, sulfur-doped porous carbons also possess good gas adsorption selectivity and excellent recyclability for regeneration

Table_1_Silage additives improve fermentation quality, aerobic stability and rumen degradation in mixed silage composed of amaranth and corn straw.docx

The objective of this research was to investigate effects of different additives on the fermentation quality, aerobic stability and rumen degradation of mixed silage composed of amaranth and corn straw. The mixture ratio of amaranth to corn straw was 78%: 22%. Three additives were selected in this study and five groups were as follows: control group (CON, without additive), lactic acid bacteria group (LAB, 5 mg/kg, Lactobacillus plantarum ≥ 1.6×1010 CFU/g and L. buchneri ≥ 4.0×109 CFU/g), glucose group (GLU, 30 g/kg), cellulase group (CEL, 2 mg/kg) and lactic acid bacteria, glucose and cellulase group (LGC, added at the same levels as in individual group). The period of ensiling was 60 days. Fermentation quality, chemical composition and aerobic stability of mixed silage were analyzed. Four cows with permanent ruminal fistula were selected as experimental animals. Nylon bag technique was used to study rumen degradation characteristic of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) of mixed silage. Compared with CON group, the addition of different silage additives could improve mixed silage quality of amaranth and corn straw to some extent. Combining three additives significantly increased (P < 0.05) the DM, CP and lactic acid contents, whereas decreased (P < 0.05) the ADF and NDF contents as well as pH and ammonia nitrogen/total nitrogen. Moreover, the aerobic stability and rumen degradation of DM, CP and NDF were significantly improved (P < 0.05) in LGC group when compared to other groups. In conclusion, the combined addition of lactic acid bacteria, glucose and cellulase increased DM, CP and lactic acid contents as well as lactic acid bacteria count, decreased NDF and ADF contents and aerobic bacteria and mold counts, improved aerobic stability and rumen degradation of amaranth and corn straw mixed silage.</p

Discrete Diblock Copolymers with Precise Stereoconfiguration

This work develops an iterative growth approach to synthesize discrete oligo lactic acids with exactly defined stereoconfiguration by connecting enantiomeric monomers (i.e., L- and D-lactic acid) following a predesigned sequence. A library of diblock copolymers with uniform chain length was modularly prepared by conjugating the stereoisomeric blocks with a chemically incompatible chain. The precise chemical structure eliminates all molecular uncertainties associated with statistical distribution and decouples the intertwined variables. A rich collection of ordered structures, including unconventional Frank–Kasper A15 and σ phases, was captured. The stereoconfiguration exerts pronounced impacts on chain conformation, leading to appreciable variations of lattice dimension and phase stability. This study quantitatively assessed the critical contribution of stereoconfiguration on packing behaviors, calling for particular attention to this essential molecular parameter as an effective handle for rational structural engineering

Discrete Diblock Copolymers with Tailored Conformational Asymmetry: A Precise Model Platform to Explore Complex Spherical Phases

Conformational asymmetry of block copolymers is a critical molecular parameter dictating the self-assembly behaviors. This work develops an efficient approach to construct block copolymers with uniform chain length and tunable conformational mismatch. Three model discrete diblock copolymers based on γ-alkyl-α-hydroxy glutaric acid and lactide monomers were prepared through the iterative growth approach. The conformational asymmetry can be adjusted via simple substitution of the hydrocarbon side chains. The precise chemical structure rules out all molecular uncertainties associated with statistical distribution, providing a delicate platform for quantitatively resolving the intricate details and underlying principles. Diverse ordered structures, including the Frank–Kasper σ and A15 phases and quasicrystalline phase, were captured. A phase portrait with an exceptionally high compositional resolution was mapped, demonstrating clearly that the spherical packing region expands and the complex phases emerge as the conformational asymmetry increases. This study explicitly correlates the origin of the intriguing structures with the intrinsic molecular parameters, providing deep insights into the formation and evolution of the complex phases in block copolymers