In Vitro Antibacterial and Anti-Inflammatory Properties of Imidazolium Poly(ionic liquids) Microspheres Loaded in GelMA-PEG Hydrogels.

Repairing damaged tissue caused by bacterial infection poses a significant challenge. Traditional antibacterial hydrogels typically incorporate various components such as metal antimicrobials, inorganic antimicrobials, organic antimicrobials, and more. However, drawbacks such as the emergence of multi-drug resistance to antibiotics, the low antibacterial efficacy of natural agents, and the potential cytotoxicity associated with metal antibacterial nanoparticles in hydrogels hindered their broader clinical application. In this study, we successfully developed imidazolium poly(ionic liquids) (PILs) polymer microspheres (APMs) through emulsion polymerization. These APMs exhibited notable antibacterial effectiveness and demonstrated minimal cell toxicity. Subsequently, we integrated the APMs into a gelatin methacryloyl (GelMA)-polyethylene glycol (PEG) hydrogel. This composite hydrogel not only showcased strong antibacterial and anti-inflammatory properties but also facilitated the migration of human skin fibroblasts (HSF) and human umbilical vein endothelial cells (HUVECs) and promoted osteogenic differentiation in vitro.

Ferroptosis of macrophages facilitates bone loss in apical periodontitis via NRF2/FSP1/ROS pathway.

Apical periodontitis (AP) is an infectious disease that causes periapical tissue inflammation and bone destruction. Ferroptosis, a novel type of regulated cell death, is closely associated with inflammatory diseases and the regulation of bone homeostasis. However, the exact involvement of ferroptosis in the bone loss of AP is not fully understood. In this study, human periapical tissues were collected, and a mouse model was established to investigate the role of ferroptosis in AP. Colocalization staining revealed that ferroptosis in macrophages contributes to the inflammatory bone loss associated with AP. A cell model was constructed using RAW 264.7 cells stimulated with LPS to further explore the mechanism underlying ferroptosis in macrophages upon inflammatory conditions, which exhibited ferroptotic characteristics. Moreover, downregulation of NRF2 was observed in ferroptotic macrophages, while overexpression of NRF2 upregulated the level of FSP1, leading to a reduction in reactive oxygen species (ROS) in macrophages. Additionally, ferroptotic macrophages released TNF-α, which activated the p38 MAPK signaling pathway and further increased ROS accumulation in macrophages. In vitro co-culture experiments demonstrated that the osteogenic ability of mouse bone marrow stromal cells (BMSCs) was suppressed with the stimulation of TNF-α from ferroptotic macrophages. These findings suggest that the TNF-α autocrine-paracrine loop in ferroptotic macrophages can inhibit osteogenesis in BMSCs through the NRF2/FSP1/ROS signaling pathway, leading to bone loss in AP. This study highlights the potential therapeutic value of targeting ferroptosis in the treatment of inflammatory bone diseases.

How aerobic exercise improves executive function in ADHD children: A resting-state fMRI study.

The aim of the study is to explore the functional magnetic resonance imaging (fMRI) characteristics of the improvement in executive function by aerobic exercise in children with attention deficit hyperactivity disorder (ADHD). Seventeen children with ADHD were selected for 8 weeks of rope skipping aerobic training, and fMRI findings and executive function were examined before and after training. Regional homogeneity (ReHo) and degree centrality (DC) indexes were used in fMRI analysis, whereas the flanker task was used to test executive function. A paired t test was used to compare the fMRI indexes and response time of executive function before and after training. After aerobic exercise, the brain regions in which the ReHo value of ADHD children significantly increased included the left middle frontal gyrus and the right superior frontal gyrus; the brain region in which the DC value increased was the right posterior cingulate cortex. The flanker task response time decreased significantly (P < 0.05, after correction) after aerobic exercise. The study findings support the hypothesis that aerobic exercise can improve the executive function of ADHD children, and the brain mechanism involved is mainly related to the enhancement of spontaneous prefrontal lobe activity.

The extracellular ß-glucosidase BGL2 has two variants with different molecular sizes and hydrolytic activities in the stipe or pilei of Coprinopsis cinerea.

Two variants of extracellular ß-glucosidase (BGL2) were purified from the stipe and pilei of Coprinopsis cinerea. In the stipe, BGL2 was a monomeric protein with an apparent molecular mass of approximately 220 kDa, representing a mature full-length peptide of BGL2. However, in the pilei, the apparent molecular mass of BGL2 was only approximately 120 kDa, consisting of the 60 kDa N-terminal fragment and 55 kDa C-terminal fragment. The hydrolytic activities of BGL2 purified from the pilei were higher than those of BGL2 purified from the stipe. No mRNA splice variants of bgl2 were detected. Therefore, the different variants of BGL2 in the stipe and pilei were not formed by differential RNA splicing. Furthermore, in vitro experiments showed that full-length BGL2 could be cleaved by endogenous proteases from pilei or commercial trypsin at a similar site to form an oligomeric protein consisting of the N-terminal fragment and C-terminal fragment similar to BGL2 from pilei. The hydrolytic activity of BGL2 increased after cleavage by those proteases in vitro. We conclude that the 120 kDa variant of BGL2 in the pilei of C. cinerea is formed by posttranslational proteolytic cleavage. Posttranslational proteolytic cleavage is an efficient way to regulate the activity of BGL2 to adapt to the needs of different physiological functions in the elongation stipe and expansion pilei of C. cinerea.

Chitosan hydrogel incorporated with dental pulp stem cell-derived exosomes alleviates periodontitis in mice via a macrophage-dependent mechanism.

Periodontitis is caused by host immune-inflammatory response to bacterial insult. A high proportion of pro-inflammatory macrophages to anti-inflammatory macrophages leads to the pathogenesis of periodontitis. As stem cell-derived exosomes can modulate macrophage phenotype, dental pulp stem cell-derived exosomes (DPSC-Exo) can effectively treat periodontitis. In this study, we demonstrated that DPSC-Exo-incorporated chitosan hydrogel (DPSC-Exo/CS) can accelerate the healing of alveolar bone and the periodontal epithelium in mice with periodontitis. Gene Ontology (GO) term enrichment analysis showed that treatment with DPSC-Exo/CS ameliorated periodontal lesion by suppressing periodontal inflammation and modulating the immune response. Specifically, DPSC-Exo/CS facilitated macrophages to convert from a pro-inflammatory phenotype to an anti-inflammatory phenotype in the periodontium of mice with periodontitis, the mechanism of which could be associated with miR-1246 in DPSC-Exo. These results not only shed light on the therapeutic mechanism of DPSC-Exo/CS but also provide the basis for developing an effective therapeutic approach for periodontitis.

Degree centrality of key brain regions of attention networks in children with primary nocturnal enuresis: A resting-state functional magnetic resonance imaging study.

Primary nocturnal enuresis (PNE) is always associated with attention impairment, some of which even could develop to attention deficit hyperactivity disorder. The mechanism of attention impairment is not clear, especially lacking of objective indicators of neuroimaging. The aim of this study is to explore the possible functional imaging mechanism of impaired attention in PNE children. A total of 26 PNE children and 26 age-matched normal controls were recruited. Resting-state functional magnetic resonance imaging (rs-fMRI) was performed on these children. Degree centrality (DC) of key brain regions of DAN (lFEF, rFEF, lIFG, rIFG, lIPS, rIPS), VAN (TPJ, VFC) and DMN (PCC, aMPFC, lAG, rAG) were calculated and compared between PNE and normal children. And the correlations between DC values and attention behavioral results were measured. Compared with normal controls, PNE children exhibited lower DC value in the right frontal eye field (rFEF), left inferior parietal sulcus (lIPS), right inferior parietal sulcus (rIPS), temporal parietal junction (TPJ) and left angular gyrus (lAG). The correct number of continuous performance test (CPT) in the PNE group was significantly lower than the normal controls and there was no significant difference in the reaction time between the two groups. The correlation between DC values and attention behavioral results in PNE showed that the DC values of PCC and lAG were negatively correlated with the correct number. This work indicates that the damage of the key brain regions of DAN, VAN and DMN might be the possible functional imaging mechanism of impaired attention in children with PNE.

Steering Surface Reaction at Specific Sites with Self-Assembly Strategy.

To discern the catalytic activity of different active sites, a self-assembly strategy is applied to confine the involved species that are "attached" to specific surface sites. The employed probe reaction system is the Ullmann coupling of 4-bromobiphenyl, C6H5C6H4Br, on an atomically flat Ag(111) surface, which is explored by combined scanning tunneling microscopy, synchrotron X-ray photoelectron spectroscopy, and density functional theory calculations. The catalytic cycle involves the detachment of the Br atom from the initial reactant to form an organometallic intermediate, C6H5C6H4AgC6H4C6H5, which subsequently self-assembles with its central Ag atom residing either on 2-fold bridge or 3-fold hollow sites at full coverage. The hollow site turns out to be catalytically more active than the bridge one, allowing us to achieve site-steered reaction control from the intermediate to the final coupling product, p-quaterphenyl, at 390 and 410 K, respectively.

The Modes of Action of ChiIII, a Chitinase from Mushroom Coprinopsis cinerea, Shift with Changes in the Length of GlcNAc Oligomers.

A putative class III endochitinase (ChiIII) was reported previously to be expressed dominantly in fruiting bodies of Coprinopsis cinerea, and its expression levels increased with the maturation of the fruiting bodies. This paper further reports that ChiIII is a novel chitinase with exo- and endoactivities. When the substrate was (GlcNAc)3-5, ChiIII exhibited exoactivity, releasing GlcNAc processively from the reducing end of (GlcNAc)3-5; when the substrate was (GlcNAc)6-7, the activity of ChiIII shifted to an endoacting enzyme, randomly splitting chitin oligosaccharides to various shorter oligosaccharides. This shift in the mode of action of ChiIII may be related to its stronger hydrolytic capacity to degrade chitin in fungal cell walls. The predicted structure of ChiIII shows that it lacks the α+ß domain insertion; however, its substrate binding cleft seems to be deeper than that of common endochitinases but shallower and more open than that of common exochitinases, which may be related to its exo- and endohydrolytic activities.

Purification, characterization and function analysis of an extracellular ß-glucosidase from elongating stipe cell walls in Coprinopsis cinerea.

A ß-glycoside hydrolase was isolated from cell walls material in Coprinopsis cinerea elongating stipes. By analysis of SDS-PAGE, MALDI-TOF/TOF MS and substrate specificity, this enzyme was characterized as an extracellular ß-glucosidase which is a trimer consisting of three homosubunits. ß-Glucosidase did not degrade ß-glucans with modified ends, whereas it hydrolyzed various ß-glucans with free ends and related oligosaccharides with ß-1,3-, ß-1,4- or ß-1,6-linkages. Although this ß-glucosidase possesses glycosyltransferase activity on laminarioligosaccharides, it did not transfer glucose residues from laminaritriose to ß-glucan in stipe cell walls to produce larger ß-glucan molecules; instead, it caused a decrease in the molecular size of stipe wall ß-glucan by removing glucose. Relatively, the molecular size of wall ß-glucans in the elongating apical stipe was less than that found in the non-elongating basal stipes, and this ß-glucosidase was more highly expressed in the elongating apical stipe than in non-elongating basal regions. Therefore, we propose that ß-glucosidase functions by trimming or cutting the ß-glucan side chains on the ß-1,3-glucan backbone to prevent them from forming longer branches, keeping the wall plastic to promote diffuse wall growth.

Comparative Study of Nonautolytic Mutant and Wild-Type Strains of Coprinopsis cinerea Supports an Important Role of Glucanases in Fruiting Body Autolysis.

Autolysis of Coprinopsis cinerea fruiting bodies affects its commercial value. In this study, a mutant of C. cinerea that exhibits pileus expansion without pileus autolysis was obtained using ultraviolet mutagenesis. This suggests that pileus expansion and pileus autolysis involve different enzymes or proteins. Among the detected hydrolytic enzymes, only ß-1,3-glucanase activity increased with expansion and autolysis of pilei in the wild-type strain, but the increase was abolished in the mutant. This suggests that ß-1,3-glucanases plays a major role in the autolysis. Although there are 43 possible ß-1,3-glucoside hydrolases genes, only 4 known genes, which have products that are thought to act synergistically to degrade the ß-1,3-glucan backbone of cell walls during fruiting body autolysis, and an unreported gene were upregulated during pileus expansion and autolysis in the wild-type stain but were suppressed in the mutant. This suggests that expression of these ß-1,3-glucanases is potentially controlled by a single regulatory mechanism.

Inverse relationship between carrier mobility and bandgap in graphene.

A frequently stated advantage of gapless graphene is its high carrier mobility. However, when a nonzero bandgap is opened, the mobility drops dramatically. The hardness to achieve high mobility and large on∕off ratio simultaneously limits the development of graphene electronics. To explore the underlying mechanism, we investigated the intrinsic mobility of armchair graphene nanoribbons (AGNRs) under phonon scattering by combining first-principles calculations and a tight-binding analysis. A linear dependence of the effective mass on bandgap was demonstrated to be responsible for the inverse mobility-gap relationship. The deformation-potential constant was found to be determined by the strain dependence of the Fermi energy and the bandgap, resulting in two mobility branches, and is essential for the high mobility of AGNRs. In addition, we showed that the transport polarity of AGNRs can be switched by applying a uniaxial strain.

Free radical reactions in two dimensions: a case study on photochlorination of graphene.

Graphene, a two-dimensional giant-molecule of sp(2) -bonded carbon atoms, provides a perfect platform for studying free radical reaction chemistry in two-dimensions, which holds promise to control the chemical functionality of graphene. Free-radical photochlorination of graphene is used as an example to investigate the thickness, stacking order, and single- and double-side dependent reactivity in graphene. Anomalously low reactivity is observed in the photochlorination of AB-stacked bilayer graphene in comparison with that of few-layer graphene. Double-sided chlorination of graphene shows higher reactivity and chlorine coverage than single-sided reaction. It is also experimentally and theoretically demonstrated that chlorine free radicals at low coverage prefer to form a stable charge-transfer complex with graphene, which highly enhances graphene's conductivity and simultaneously generates a pseudo-bandgap through noninvasive doping. Moreover, the initial accumulation of chlorine radicals is considered as the rate-determining step of photochlorination of graphene.

Photo-induced free radical modification of graphene.

Graphene has stimulated enormous interest due to its intriguing structure and fascinating properties. The extremely high carrier mobility, mechanical flexibility, and optical transparency as well as the versatility for band structure engineering make graphene a promising candidate for next-generation carbon-based electronic devices. Graphene chemistry, the covalent functionalization of graphene as a 2D giant molecule, offers a promising direction to controllably tailor its properties through the introduction of various chemical decorations. One of the great challenges for graphene functionalization originates from its strong chemical stability, thus highly reactive chemical species are needed as the reactants. In recent years, novel photochemical approaches have been developed to achieve efficient graphene modification and bandgap modulation, following a general concept of "Photochemical Bandgap Engineering of Graphene". In this article, such kinds of photochemical graphene engineering are demonstrated, together with a brief discussion on the future directions, challenges, and opportunities in this fascinating research area.

Janus graphene from asymmetric two-dimensional chemistry.

Janus materials have distinct surfaces on their opposite faces. Graphene, a two-dimensional giant molecule, provides an excellent candidate to fabricate the thinnest Janus discs and study the asymmetric chemistry of atomic-thick nanomembranes using covalent chemical functionalisation. Here we present the first experimental realisation of nonsymmetrically modified single-layer graphene--Janus graphene--which is fabricated by a two-step surface covalent functionalisation assisted by a poly(methyl methacrylate)-mediated transfer approach. Four types of Janus graphene are produced by co-grafting of halogen and aryl/oxygen-functional groups on each side. Chemical decorations on one side are found to be capable of affecting both chemical reactivity and physical wettability of the opposite side, indicative of communication between the two grafted groups. This novel asymmetric structure provides a platform for theoretical and experimental studies of two-dimensional chemistry and graphene devices with multiple functions.

Graphene quantum dots embedded in a hexagonal BN sheet: identical influences of zigzag/armchair edges.

Various graphene quantum dots (GQDs) embedded in a hexagonal BN sheet were studied theoretically using the tight binding model. The effective mass was analyzed as a function of the distance between neighboring GQDs. It was found that the effective mass increases exponentially as the distance increases, indicating that the confined states of GQDs are well conserved in these hybrid systems. Further studies revealed that a ubiquitous gap of 0.3-3 eV exists, the size of which is mainly governed by the GQD's dimensions whereas it is insensitive to edge structures. These results show that GQDs in BN are promising candidates for optoelectronics.

Novel three-dimensional 3d-4f microporous magnets exhibiting selective gas adsorption behavior.

Three microporous Ln-Co-pyta heterometallic compounds [Ln4Co3(pyta)6(H2O)9].5H2O (Ln = Sm (1), Eu (2), Gd (3); H3pyta = 2,4,6-pyridinetricarboxylic acid) have interesting selective adsorption abilities towards H2/N2 and CO2/N2 because of size-selective effects; magnetic analysis reveals that has a ferromagnetic behavior.

Atomic and molecular adsorption on RhMn alloy surface: a first principles study.

Density functional theory calculations have been employed to study the effects of alloy on energetics and preferential adsorption sites of atomic (H, C, N, O, S), molecular (N(2), NO, CO), and radical (CH(3), OH) adsorption on RhMn(111) alloy surface, and underlying electronic and structural reasons have been mapped out. We find that though Mn is energetically favorable to stay in the subsurface region, the RhMn surface alloy may be developed via the segregation induced by strong interaction between oxygen-containing species and Mn. Independent of adsorbates (not including O and OH), the interactions between these species and Rh atoms are preferential, and enhanced in general due to the ligand effects induced by Mn nearby. In contrast, oxygen-containing species (atomic oxygen and hydroxyl) prefer to coordinate with Mn atom due to the significant hybridization between oxygen and Mn, a manifestation of the ensemble effects. The order of the binding energies on RhMn alloy surface from the least to the most strongly bound is N(2)

Density functional theory study of CHx (x=1-3) adsorption on clean and CO precovered Rh(111) surfaces.

CH(x) (x=1-3) adsorptions on clean and CO precovered Rh(111) surfaces were studied by density functional theory calculations. It is found that CH(x) (x=1-3) radicals prefer threefold hollow sites on Rh(111) surfaces, and the bond strength between CH(x) and Rh(111) follows the order of CH(3)