Glutathione (GSH) serves many cellular functions and plays crucial roles in human pathologies. Simple and sensitive sensors capable of detecting GSH would be useful tools to understand the mechanism ...of diseases. In this work, a rapid fluorescence “switch-on” assay was developed to detect trace amount of GSH based on carbon dots–MnO2 nanocomposites, which was fabricated through in situ synthesis of MnO2 nanosheets in carbon dots colloid solution. Due to the formation of carbon dots–MnO2 nanocomposites, fluorescence of carbon dots could be quenched efficiently by MnO2 nanosheeets through fluorescence resonance energy transfer (FRET). However, the presence of GSH would reduce MnO2 nanosheets to Mn2+ ions and subsequently release carbon dots, which resulted in sufficient recovery of fluorescent signal. This proposed assay demonstrated highly selectivity toward GSH with a detection limit of 300nM. Moreover, this method has also shown sensitive responses to GSH in human serum samples, which indicated its great potential to be used in disease diagnosis. As no requirement of any further functionalization of these as-prepared nanomaterials, this sensing system shows remarkable advantages including very fast and simple, cost-effective as well as environmental-friendly, which suggest that this new strategy could serve as an efficient tool for analyzing GSH level in biosamples.
•A novel fluorescence “switch-on” biosensor is designed for glutathione detection by using carbon dots–MnO2 nanocomposites.•This sensing system displays remarkable properties including simplicity, very short assay time, low-cost as well as nontoxicity.•Results for human serum samples demonstrated that this biosensor is highly applicable for the detection of GSH in biological environments.
Arachidonic acid (AA) is an n‐6 polyunsaturated 20‐carbon fatty acid taking important immunomodulatory roles in infant growth, brain development, and health. However, one of the major drawbacks of ...polyunsaturated fatty acids is their high susceptibility to oxidation followed by unpleasant odors. Microencapsulation has been proposed as an excellent strategy to solve these problems. In this work, coaxial electrospray was utilized to fabricate AA/zein microcapsules with core‐shell structures which were verified by scanning electron microscopy, transmission electron microscopy, and confocal laser scanning microscopy. Microcapsules morphology was conveniently controlled through electrospray parameters and AA was centralized in the core. The microcapsule diameter ranged from 1 to 7 μm. Results of peroxide values and GC–MS demonstrated that AA in microcapsules possess improved oxidative stability and the unpleasant odors of AA oil was inhibited. The results indicate coaxial electrospray is a useful and convenient tool to fabricate core‐shell microcapsules with immiscible materials, which will broaden the potential use of microcapsules as nutrition fortifiers in the food industry.
The tumor stromal microenvironments (TSM) including stromal cells and extracellular matrix (ECM) form an abominable barrier hampering nanoparticles accessibility to cancer cells, significantly ...compromising their antitumor effects. Herein, we report a bioinspired lipoprotein (bLP) that can induce efficient photothermia to remodel TSM and improve second bLP accessibility to cancer cells for antitumor therapy. The multiple stromal cells and ECM components in TSM are remarkably disrupted by bLP-mediated photothermal effects, which cause a 4.27-fold enhancement of second bLP accumulation in tumor, deep penetration in whole tumor mass and 27.0-fold increase of accessibility to cancer cells. Of note, this bLP-mediated TSM-remodeling to enhance cancer cell accessibility (TECA) strategy produces an eminent suppression of tumor growth and results in a 97.4% inhibition of lung metastasis, which is superior to the counterpart liposomes. The bLP-mediated TECA strategy provides deeper insights into enhancing nanoparticle accessibility to cancer cells for antitumor therapy.
Photothermal therapy (PTT) has been widely applied in cancer therapy as a result of its non-invasive, localized treatment and good therapeutic effect. In general, the final therapeutic effect of PTT ...mainly depends on the photothermal materials, which can be further considered to be determined by the photothermal conversion efficiency, biocompatibility, and photothermal stability of photothermal materials. In this review, photothermal materials including inorganic materials, organic materials, and organic-inorganic composite materials in recent years have been summarized in terms of the mechanism, preparation, and cancer therapy applications. In the end, the perspectives and obstacles in their further development are overviewed.
The motion of electrons in the microcosm occurs on a time scale set by the atomic unit of time-24 attoseconds. Attosecond pulses at photon energies corresponding to the fundamental absorption edges ...of matter, which lie in the soft X-ray regime above 200 eV, permit the probing of electronic excitation, chemical state, and atomic structure. Here we demonstrate a soft X-ray pulse duration of 53 as and single pulse streaking reaching the carbon K-absorption edge (284 eV) by utilizing intense two-cycle driving pulses near 1.8-μm center wavelength. Such pulses permit studies of electron dynamics in live biological samples and next-generation electronic materials such as diamond.Isolated attosecond pulses are produced using high harmonic generation and sources of these pulses often suffer from low photon flux in soft X-ray regime. Here the authors demonstrate efficient generation and characterization of 53 as pulses with photon energy near the water window.
The 14-subunit metazoan-specific Integrator contains an endonuclease that cleaves nascent RNA transcripts. Here, we identified a complex containing Integrator and protein phosphatase 2A core enzyme ...(PP2A-AC), termed INTAC. The 3.5-angstrom-resolution structure reveals that nine human Integrator subunits and PP2A-AC assemble into a cruciform-shaped central scaffold formed by the backbone and shoulder modules, with the phosphatase and endonuclease modules flanking the opposite sides. As a noncanonical PP2A holoenzyme, the INTAC complex dephosphorylates the carboxy-terminal repeat domain of RNA polymerase II at serine-2, -5, and -7 and thus regulates transcription. Our study extends the function of PP2A to transcriptional regulation and reveals how dual enzymatic activities-RNA cleavage and RNA polymerase II dephosphorylation-are structurally and functionally integrated into the INTAC complex.
Summary
Post‐translational modification of proteins mediated by SIZ1, a small ubiquitin‐like modifier (SUMO) E3 ligase, regulates multiple biological processes in plants. However, its role in the ...regulation of lateral root formation remains unclear. Here, we demonstrate that the apple SUMO E3 ligase MdSIZ1 promotes lateral root formation.
Using a yeast‐two‐hybrid (Y2H) system, the auxin response factor MdARF8 was screened out as a protein–protein interaction partner of the SUMO‐conjugating E2 enzyme MdSCE1, indicating that MdARF8 may be a substrate for MdSIZ1. The interaction between MdARF8 and MdSCE1 was confirmed by pull‐down, Y2H and Co‐immunoprecipitation assays.
MdSIZ1 enhanced the conjugating enzyme activity of MdSCE1 to form a MdSCE1–MdSIZ1–MdARF8 complex, thereby facilitating SUMO modification. We identified two arginine substitution mutations at K342 and K380 in MdARF8 that blocked MdSIZ1‐mediated SUMOylation, indicating that K342 and K380 are the principal SUMOylation sites of the MdARF8 protein. Moreover, MdARF8 promoted lateral root formation in transgenic apple plants, and the phenotype of reduced lateral roots in the Arabidopsis siz1‐2 mutant was restored in siz1‐2/MdARF8 complementary plants.
Our findings reveal an important role for sumoylation in the regulation of lateral root formation in plants.
In this article, a miniaturized circular planar inverted‐F antenna (PIFA) is proposed for biomedical applications, operating in Medical Device Radiocommunications Service (MedRadio; 401‐406 MHz) band ...and Industrial Scientific and Medical (ISM; 2.4‐2.4835 GHz) band. It consists of a U‐shaped patch on top layer, a circular ground on bottom layer, and a shorting pin connecting two layers. By adding two sets of open‐end slots in the ground, dual‐band performance of the proposed antenna is achieved with compact size. Measurement result shows that a wide bandwidth of 41%, ranging from 345 to 510 MHz, can be achieved in MedRadio band, and a wide bandwidth of 27.8%, ranging from 1.92 to 2.60 GHz, can be achieved in ISM band.
•A multi-phase cracking model is developed for well capturing the crack distribution patterns in concrete.•A multi-species transport model is developed to describe chloride transport in cracked ...concrete by considering ionic interactions.•A statistical learning model is proposed to couple the time-dependent processes of crack propagation and ionic transport.•The impacts of various crack characteristics and other factors on chloride penetration are discussed in detail.
Reinforced concrete (RC) structures have been severely threatened by chloride attacks during long-term service, particularly under mechanical loading conditions. This study presents a multi-species and multi-phase model considering the time-dependent cracking in concrete. In addition to the crack propagation and chloride diffusion being individually modelled, these two processes are coupled by statistical learning approach, which is supposed to better reveal the influence of cracking on chloride transport. Meanwhile, the electrostatic potential generated by the inner charge imbalance and its effect on multi-species transport is also considered. The validity of the presented model is verified against third-party experiments following the standard of RILEM TC 246-TDC. The impact of different crack characteristics on chloride transport was carefully elaborated, and the effects caused by multi-species interactions, coupling between cracking and chloride ingress, as well as other environmental factors such as external concentration are also discussed in detail. The findings of presented study can better enhance the understanding on the deterioration of both durability and bearing capacity of RC structures.
Toad venom, a traditional natural medicine, has been used for hundreds of years in China for treating different diseases. Many studies have been performed to elucidate the cardiotonic and analgesic ...activities of toad venom. Until the last decade, an increasing number of studies have documented that toad venom is a source of lead compound(s) for the development of potential cancer treatment drugs. Research has shown that toad venom contains 96 types of bufadienolide monomers and 23 types of indole alkaloids, such as bufalin, cinobufagin, arenobufagin, and resibufogenin, which exhibit a wide range of anticancer activities in vitro and, in particular, in vivo for a range of cancers. The main antitumor mechanisms are likely to be apoptosis or/and autophagy induction, cell cycle arrest, cell metastasis suppression, reversal of drug resistance, or growth inhibition of cancer cells. This review summarizes the chemical constituents of toad venom, analyzing their anticancer activities and molecular mechanisms for cancer treatments. We also outline the importance of further studies regarding the material basis and anticancer mechanisms of toad venom.
Many studies were performed to elucidate the cardiotonic and analgesic activities of toad venom. An increasing number of studies show that toad venom can also be a source of lead compound(s) for the development of potential cancer treatment drugs. This review summarizes the chemical constituents of toad venom, analyzing their anticancer activities and molecular mechanisms for cancer treatments.
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