Cell polarization exists in a variety of tissues to regulate cell behaviors and functions. Space constraint (spatially limiting cell extension) and adhesion induction (guiding adhesome growth) are ...two main ways to induce cell polarization according to the microenvironment topographies. However, the mechanism of cell polarization induced by these two ways and the downstream effects on cell functions are yet to be understood. Here, space constraint and adhesion induction guiding cell polarization are achieved by substrate groove arrays in micro and nano size, respectively. Although the morphology of polarized cells is similar on both structures, the signaling pathways to induce the cell polarization and the downstream functions are distinctly different. The adhesion induction (nano‐groove) leads to the formation of focal adhesions and activates the RhoA/ROCK pathway to enhance the myosin‐based intracellular force, while the space constraint (micro‐groove) only activates the formation of pseudopodia. The enhanced intracellular force caused by adhesion induction inhibits the chromatin condensation, which promotes the osteogenic differentiation of stem cells. This study presents an overview of cell polarization and mechanosensing at biointerface to aid in the design of novel biomaterials.
Both space constraint and adhesion induction effects induce similar polarized morphology for the adhesive cells. Here, distinct molecular mechanisms are revealed. The adhesion induction leads to focal adhesion formation and activates the RhoA/ROCK pathway to promote the myosin‐based intracellular force. Meanwhile, the space constraint activates the pseudopodia via Rac and CDC42 signaling in an intracellular force‐independent manner.
Growth of covalent organic frameworks (COFs) as single crystals is extremely challenging. Inaccessibility of open‐structured single‐crystal COFs prevents the exploration of structure‐oriented ...applications. Herein we report for the first time a non‐interpenetrated single‐crystal COF, LZU‐306, which possesses the open structure constructed exclusively via covalent assembly. With a high void volume of 80 %, LZU‐306 was applied to investigate the intrinsic dynamics of reticulated tetraphenylethylene (TPE) as the individual aggregation‐induced‐emission moiety. Solid‐state 2H NMR investigation has determined that the rotation of benzene rings in TPE, being the freest among the reported cases, is as fast as 1.0×104 Hz at 203 K to 1.5×107 Hz at 293 K. This research not only explores a new paradigm for single‐crystal growth of open frameworks, but also provides a unique matrix‐isolation platform to reticulate functional moieties into a well‐defined and isolated state.
A 3D single‐crystal COF with a non‐interpenetrated structure was constructed for the first time. The highly open framework provides a unique matrix‐isolation platform to investigate the intrinsic dynamics of individual AIE moiety.
A novel and unusual palladium‐catalyzed 4+2 annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si−C(sp2) bond activation in synergy with ...ring expansion/insertion of cyclopropenes to form new C(sp2)−C(sp3) and Si−C(sp3) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo4.1.0heptanes, were formed in good yields with excellent diastereoselectivity under mild conditions. An asymmetric version of the reaction with a chiral phosphoramidite ligand furnished a variety of chiral bicyclic silaheterocycle derivatives with good enantioselectivity (up to 95.5:4.5 er). Owing to the mild reaction conditions, the good stereoselectivity profile, and the ready availability of the functionalized precursors, this process constitutes a useful and straightforward strategy for the synthesis of densely functionalized silacycles.
When Si−C meets C=C bond activation: Cyclopropenes were functionalized stereoselectively with benzosilacyclobutanes by palladium‐catalyzed Si−C(sp2) bond activation and a ring‐expansion/4+2 annulation sequence to form new C(sp2)−C(sp3) and Si−C(sp3) bonds of silabicyclo4.1.0heptanes. The transformation provided an array of these previously elusive highly strained bicyclic skeletons in good yields with high selectivity (see scheme).
Abstract
Fungal hybrid terpenoid saccharides constitute a new and growing family of natural products with significant biomedical and agricultural activities. One representative family is the ...cosmosporasides, which feature oxidized terpenoid units and saccharide moieties; however, the assembly line of these building blocks has been elusive. Herein, a
cos
cluster from
Fusarium orthoceras
was discovered for the synthesis of cosmosporaside C (
1
) by genome mining. A UbiA family intramembrane prenyltransferase (UbiA‐type PT), a multifunctional cytochrome P450, an α,β‐hydrolase, an acetyltransferase, a dimethylallyl transferase (DMAT‐type PT) and a glycosyltransferase function cooperatively in the assembly of the scaffold of
1
using primary central metabolites. The absolute configuration at C4, C6 and C7 of
1
was also established. Our work clarifies the unexpected functions of UbiA‐type and DMAT‐type PTs and provides an example for understanding the synthetic logic of hybrid terpenoid saccharides in fungi.
Information processing with optoelectronic devices provides an alternative way to efficiently process hybrid optical and electronic signals. Ferroelectric field‐effect transistors (FeFETs) can ...effectively respond to external optical and electrical stimuli by modulating their polarization states. Here, a 2D FeFET is demonstrated by the epitaxial growth of high‐quality 2D bismuth layered oxyselenide (Bi2O2Se) films on PMN‐PT(001) ferroelectric single‐crystal substrates. Upon switching the polarization direction of PMN‐PT, the authors realize in situ, reversible, and nonvolatile manipulation of the resistance of Bi2O2Se thin film (≈877%). The device simultaneously exhibits a polarization‐dependent photoresponse through visible light (λ = 405 nm) and infrared light (IR, λ = 980 nm) illumination. Combining optical stimuli with ferroelectric gating, it is demonstrated that the devices not only show nonvolatile memory and optoelectronic responses, but also show coincidence detection of visible and IR light. This work holds great potential in constructing new multiresponse and multifunction 2D‐FeFETs.
2D ferroelectric field‐effect transistors devices are fabricated by epitaxial growth of Bi2O2Se on Pb(Mg1/3Nb2/3)O3‐PbTiO3. The devices exhibit ferroelectric polarization‐dependent photoresponse upon visible light (λ = 405 nm) and infrared light (IR, λ = 980 nm) illumination. Combining optical stimuli with ferroelectric gating, the devices show not only nonvolatile memory and optoelectronic response, but also coincidence detection of visible and infrared light.
Hydrosilylation of unsaturated carbon-carbon bonds with hydrosilanes is a very important process to access organosilicon compounds and ranks as one of the most fundamental reactions in organic ...chemistry. However, catalytic asymmetric hydrosilylation of activated alkenes and internal alkenes has proven elusive, due to competing reduction of carbon-carbon double bond or isomerization processes. Herein, we report a highly enantioselective Si-C coupling by hydrosilylation of carbonyl-activated alkenes using a palladium catalyst with a chiral TADDOL-derived phosphoramidite ligand, which inhibits O-hydrosilylation/olefin reduction. The stereospecific Si-C coupling/hydrosilylation of maleimides affords a series of silyl succinimides with up to 99% yield, >99:1 diastereoselectivity and >99:1 enantioselectivity. The high degree of stereoselectivity exerts remote control of axial chirality, leading to functionalized, axially chiral succinimides which are versatile building blocks. The product utility is highlighted by the enantioselective construction of N-heterocycles bearing up to three stereocenters.
Developing antibiotics-independent antibacterial agents is of great importance since antibiotic therapy faces great challenges from drug resistance. Graphene oxide (GO) is a promising agent due to ...its natural antibacterial mechanisms, such as sharp edge-mediated cutting effect. However, the antibacterial activity of GO is limited by its negative charge and low photothermal effect. Herein, the amino-functionalized GO nanosheets (AGO) with unique three-in-one properties were synthesized. Three essential properties (positive charge, strong photothermal effect, and natural cutting effect) were integrated into AGO. The positive charge (30 mV) rendered AGO a strong interaction force with model pathogen
Streptococcus mutans
(330 nN). The natural cutting effect of 100 µg·mL
−1
AGO caused 27% loss of bacterial viability after incubation for 30 min. Most importantly, upon the near-infrared irradiation for just 5 min, the three-in-one properties of AGO caused 98% viability loss. In conclusion, the short irradiation period and the tunable antibacterial activity confer the three-in-one AGO a great potential for clinical use.
To investigate the clinical and magnetic resonance imaging (MRI) features for preoperatively discriminating primary ovarian mucinous malignant tumors (POMTs) and metastatic mucinous carcinomas ...involving the ovary (MOMCs).
This retrospective multicenter study enrolled 61 patients with 22 POMTs and 49 MOMCs, which were pathologically proved between November 2014 to Jane 2023. The clinical and MRI features were evaluated and compared between POMTs and MOMCs. Univariate and multivariate analyses were performed to identify the significant variables between the two groups, which were then incorporated into a predictive nomogram, and ROC curve analysis was subsequently carried out to evaluate diagnostic performance.
35.9% patients with MOMCs were discovered synchronously with the primary carcinomas; 25.6% patients with MOMCs were bilateral, and all of the patients with POMTs were unilateral. The biomarker CEA was significantly different between the two groups (p = 0.002). There were significant differences in the following MRI features: tumor size, configuration, enhanced pattern, the number of cysts, honeycomb sign, stained-glass appearance, ascites, size diversity ratio, signal diversity ratio. The locular size diversity ratio (p = 0.005, OR = 1.31), and signal intensity diversity ratio (p = 0.10, OR = 4.01) were independent predictors for MOMCs. The combination of above independent criteria yielded the largest area under curve of 0.922 with a sensitivity of 82.3% and specificity of 88.9%.
Patients with MOMCs were more commonly bilaterally and having higher levels of CEA, but did not always had a malignant tumor history. For ovarian mucin-producing tumors, the uniform locular sizes and signal intensities were more predict MOMCs.
This study aimed to identify shared specific genes associated with rheumatoid arthritis (RA) and inflammatory bowel disease (IBD) through bioinformatic analysis and to examine the role of the gut ...microbiome in RA. The data were extracted from the 3 RA and 1 IBD gene expression datasets and 1 RA gut microbiome metagenomic dataset. Weighted correlation network analysis (WGCNA) and machine learnings was performed to identify candidate genes associated with RA and IBD. Differential analysis and two different machine learning algorithms were used to investigate RA's gut microbiome characteristics. Subsequently, the shared specific genes related to the gut microbiome in RA were identified, and an interaction network was constructed utilizing the gutMGene, STITCH, and STRING databases. We identified 15 candidates shared genes through a joint analysis of the WGCNA for RA and IBD. The candidate gene CXCL10 was identified as the shared hub gene by the interaction network analysis of the corresponding WGCNA module gene to each disease, and CXCL10 was further identified as the shared specific gene by two machine learning algorithms. Additionally, we identified 3 RA-associated characteristic intestinal flora (Prevotella, Ruminococcus, and Ruminococcus bromii) and built a network of interactions between the microbiomes, genes, and pathways. Finally, it was discovered that the gene CXCL10 shared between IBD and RA was associated with the three gut microbiomes mentioned above. This study demonstrates the relationship between RA and IBD and provides a reference for research into the role of the gut microbiome in RA.
Abstract In recent decades, fungi have emerged as significant sources of diverse hybrid terpenoid natural products, and their biosynthetic pathways are increasingly unveiled. This review mainly ...focuses on elucidating the various strategies underlying the biosynthesis and assembly logic of these compounds. These pathways combine terpenoid moieties with diverse building blocks including polyketides, nonribosomal peptides, amino acids, p ‐hydroxybenzoic acid, saccharides, and adenine, resulting in the formation of plenty of hybrid terpenoid natural products via C−O, C−C, or C−N bond linkages. Subsequent tailoring steps, such as oxidation, cyclization, and rearrangement, further enhance the biological diversity and structural complexity of these hybrid terpenoid natural products. Understanding these biosynthetic mechanisms holds promise for the discovery of novel hybrid terpenoid natural products from fungi, which will promote the development of potential drug candidates in the future.
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