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Covalent organic frameworks (COFs), as a novel class of functional polymers, exhibit versatile applications due to their crystalline porous structures and conjugated skeletons. However, synthesis of COFs with high crystallinity still faces great challenges, especially for scale-up preparation. Herein we report a two-step solvothermal process to improve crystallinity of COFs. The first step focuses on polycondensation of monomers with no need for optimizing crystallization conditions. In the second step, appropriate solvothermal conditions are used to facilitate crystallization of the COFs through defects correction and structural repairing. Furthermore, this strategy could also be applicable to scale-up synthesis of high quality COFs, which lays a foundation for their practical applications.

Since the 1990s, continuous technical and scientific advances have defied the diffraction limit in microscopy and enabled three-dimensional (3D) super-resolution imaging. An important milestone in this pursuit is the coherent utilization of two opposing objectives (4Pi geometry) and its combination with super-resolution microscopy. Herein, we review the recent progress in 4Pi nanoscopy, which provides a 3D, non-invasive, diffraction-unlimited, and isotropic resolution in transparent samples. This review includes both the targeted and stochastic switching modalities of 4Pi nanoscopy. The schematics, principles, applications, and future potential of 4Pi nanoscopy are discussed in detail.

In this work, sewage sludge flocculated with ferrous sulfate (SFS) was treated by one-step pyrolysis and ZnCl2 activation to obtain magnetic Fe-containing carbon, which was used to remove elemental mercury (Hg0) from flue gas. When 30% ZnCl2 was added to SFS (names as SFS-30), sulfides, chloride, magnetic FexOy, as well as a suitable BET surface area were produced during pyrolysis. SFS-30 showed a maximum mercury removal efficiency of 96.1%. The presence of O2 and a low SO2 concentration enhanced Hg0 removal, while H2O vapor and a high concentration of SO2 inhibited it. The addition of ZnCl2 increased the BET surface area as well as the conversion of sulfate to sulfide, which were both beneficial for Hg0 removal. In addition, the generated magnetism during the pyrolysis process assisted in the recovery and utilization of SFS-30 in flue gas. After being magnetically separated from a mixture with fly ash, spent SFS-30 was thermally regenerated and recycled. After 8 Hg0 capture and regeneration cycles, the removal efficiency was not notably degraded, demonstrating that SFS-30 prepared by one-step pyrolysis with ZnCl2 activation can be used for Hg0 removal. The results of this study have guiding significance for practical engineering applications of this material.

To realize the application of xylan based film in food and drug packaging, the poor mechanical property and film-forming property of xylan based film must be overcome. Herein, a good oxygen barrier composite film with desired mechanical properties was prepared based on carboxymethly xylan (CMX), chitosan (CS), and graphene oxide (GO). The results of scanning electron microscope revealed the composite film had a dense and continuous structure, which will endow the composite film with excellent mechanical property. As expected, the composite film with the 0.5% mass fraction of GO exhibited best mechanical property, among which the tensile stress, tensile strain, and Young's modulus of the composite film reached 50.81 MPa, 47.61%, and 1.39 GPa, respectively. The oxygen barrier properties of the composite films significantly increased with the addition of graphene oxide due to the dense, stacked multilayer structure. In addition, these composite films exhibited good antibacterial properties. Therefore, these films show great promise in the field of food packaging and wound dressing due to their excellent mechanical, oxygen barrier and antibacterial properties.

Phase change materials (PCM) are promising for thermal regulation and energy storage, but suffer from the deformation and leakage of capsules. Herein, inspired by cellulose nanocrystal (CNC), xylan nanocrystal (XNC) with a dimension of 25-60 nm was successfully prepared through oxalic acid hydrolysis of high-crystalline xylan as raw materials via a top-down approach. With the introduction of hydrophobic groups, compared to XNC, succinylated XNC showed more remarkable emulsifying property over 7 days of storage at room temperature. Microencapsulated PCM composite consisting of sodium alginate (SA) as "matrix" and succinylated xylan nanocrystal (XNC) stabilized paraffin-based Pickering capsule (PCM beads) as "core" was facilely fabricated. PCM composite with the latent heat of 105.59 J·g

Skin care biomaterials from natural compounds are increasingly needed in recent. We demonstrate a simple strategy to fabricate the dialdehyde xylan (DAX) crosslinked hydrogel with skin care potential. The hydrogel mainly consists of dialdehyde xylan, which is used as crosslinker for gelatin (G). Glycerol (Gly) and nicotinamide (NCA) are introduced here for improving the texture, antibacterial property as well as skin care functionality. The in vitro release results demonstrate that NCA can be released smoothly from the xylan-based gel, whereby the xylan-based fabricated gel can be utilized as an ideal matrix gel in skin care with loading and release function. The antibacterial ability is in the following order: Yeast > Bacillus subtilis > Staphylococcus aureus. The cytocompatibility experiments confirm the excellent viability of the gel. These merits demonstrate the fabricated hydrogel as a potential material in skin care.

A heteropore covalent organic framework (COF) integrating tetraphenylethene skeleton and catechol segment is designed and synthesized. It exhibits extremely high stability in water under different pH conditions, which makes it an excellent material for adsorptive removal of Cd(II) from aqueous solutions with very fast adsorption kinetics, high uptake capacity, and good recyclability.

Background and aims Bile acids play important roles in lipid metabolism. Several studies have found that patients with coronary artery disease (CAD) have lower bile acid fecal excretion compared to individuals without CAD. However, few studies have focused on the roles of more accessible serum total bile acids (TBA) in the progression of CAD. The aim of this study was to explore the potential relationship between fasting serum TBA and the presence of CAD, myocardial infarction (MI) and severity of coronary lesions. Methods A total of 7438 consecutive patients with suspected CAD, who had undergone coronary angiography, were enrolled. The severity of coronary lesions was evaluated using the Gensini score (GS). The relationships between fasting serum TBA and the presence and severity of CAD were evaluated. Results CAD patients had lower serum TBA than individuals without CAD, and patients with MI had lower TBA than those without CAD. Spline analyses showed an L-shaped relationship of the fasting serum TBA with the presence and severity of CAD, and the breakpoint approximated the normal upper limit (10 μmol/L). A lower TBA concentration (less than the median 3.6 μmol/L) was independently and significantly associated with the presence and severity of CAD, especially for the presence of MI (odds ratios 2.04, 95% confidence interval (1.71–2.44), C-index 0.9269). Conclusions Fasting serum TBA level is highly associated with the presence and severity of CAD in patients undergoing coronary angiography for suspected CAD.

Selective dissolution of industrial biowaste is of significant importance for the valorization of biomass. Especially, fractionation of polysaccharides with similar structures is more challenging. Herein, a new kind of cationic hydrotrope, tetraethylammonium hydroxide (TEAH), has been developed for rapid, efficient, and selective dissolution of industrial biowastes-xylan type hemicelluloses from viscose fiber mills. When the concentration of TEAH is 15 wt%, the solubility of industrial crystalline xylan reaches to 13.39 wt% at room temperature. Crystalline or amorphous xylan can be regenerated by adding water or ethanol, with 57.98 % and 95.45 % yields, respectively. Additionally, we showcase hemicelluloses were near-completely extracted from holocellulose without degrading cellulose under ambient temperature by simply adjusting the concentration of TEAH, demonstrating the advantage of the hydrotropic feature. This hydrotrope solvent system features selective, rapid, and room temperature dissolution polysaccharides, which will shed new light in technological applications of the industrial spinning or biorefining processes.