Quantum dot-based fluorescence immunosorbent assay for the rapid detection of bacitracin zinc in feed samples.

Bacitracin zinc (BAC), a polypeptide antibiotic, is utilized as a feed additive due to its ability to promote growth in animals. However, the abuse of BAC can lead to a great threat to food safety. Therefore, there is an urgent need to develop a rapid and sensitive detection method. In this study, a monoclonal antibody (mAb) against BAC with excellent sensitivity and specificity was obtained. For the first time, quantum dots (QDs) were conjugated with the prepared mAb against BAC and rabbit anti-mouse antibody to fabricate a direct and an indirect competitive fluorescence-linked immunosorbent assay (dc-FLISA and ic-FLISA) to detect BAC. The IC50 of dc-FLISA and ic-FLISA were 0.28 ng/ml and 0.17 ng/ml, respectively. The limits of detection were 0.0016 ng/ml and 0.001 ng/ml, respectively, and the detection ranges were 0.0016-46.50 ng/ml and 0.001-35.65 ng/ml, respectively. In addition, the recovery rate of the two methods ranged from 93.5% to 112.0%, and the coefficient of variation (CV) was less than 10%. Therefore, the methods developed in this work have the merits of low cost, simple operation, and high sensitivity, which provide an effective analytical tool for BAC residue detection in feed samples.

EMD-57033 Augments the Contractility in Porcine Myocardium by Promoting the Activation of Myosin in Thick Filaments.

Sufficient cardiac contractility is necessary to ensure the sufficient cardiac output to provide an adequate end-organ perfusion. Inadequate cardiac output and the diminished perfusion of vital organs from depressed myocardium contractility is a hallmark end-stage of heart failure. There are no available therapeutics that directly target contractile proteins to improve the myocardium contractility and reduce mortality. The purpose of this study is to present a proof of concept to aid in the development of muscle activators (myotropes) for augmenting the contractility in clinical heart failure. Here we use a combination of cardiomyocyte mechanics, the biochemical quantification of the ATP turnover, and small angle X-ray diffraction on a permeabilized porcine myocardium to study the mechanisms of EMD-57033 (EMD) for activating myosin. We show that EMD increases the contractility in a porcine myocardium at submaximal and systolic calcium concentrations. Biochemical assays show that EMD decreases the proportion of myosin heads in the energy sparing super-relaxed (SRX) state under relaxing conditions, which are less likely to interact with actin during contraction. Structural assays show that EMD moves the myosin heads in relaxed muscles from a structurally ordered state close to the thick filament backbone, to a disordered state closer to the actin filament, while simultaneously inducing structural changes in the troponin complex on the actin filament. The dual effects of EMD on activating myosin heads and the troponin complex provides a proof of concept for the use of small molecule muscle activators for augmenting the contractility in heart failure.

Multiple fluorescence immunoassay for the simultaneous detection of Zearalenone and Ochratoxin A.

A sensitive and accurate multiple fluorescence immunoassay for the simultaneous quantitative detection of Zearalenone (ZEN) and Ochratoxin A (OTA) in single spot based on multicolor quantum dots (QDs) labeling was developed for the first time. Two kinds of ZnCdSe/ZnS (core/shell) QDs with maximum emission wavelengths at 520 nm (green) and 610 nm (orange-red) were selected as marking materials, respectively. The anti-ZEN-mAb-QDs and anti-OTA-mAb-QDs were designed as the immune fluorescent probes. Fluorescence was measured at the same excitation wavelength and two different emission wavelengths to determine each target. The procedure for QDs-based multiple fluorescence labeled immunosorbent assay (M-FLISA) was developed. The 50% inhibition concentrations (IC50) of ZEN and OTA were 0.034 and 1.175 ng/mL. Moreover, the limits of detection (LOD) for the simultaneous determination were 0.0239 and 2.339 ng/g for ZEN and OTA in maize, respectively. In addition, the recoveries ranged from 93.15 to 101.90% for ZEN and from 95.29 to 102.43% for OTA, with the coefficient variation (CV) of 2.70-8.86% and 3.51-6.22% respectively. There was good consistency between the M-FLISA and high performance liquid chromatography (HPLC) results, which confirmed that the M-FLISA was suitable for the simultaneous quantitative detection of various mycotoxins.

Multilayered N-Glycoproteome Profiling Reveals Highly Heterogeneous and Dysregulated Protein N-Glycosylation Related to Alzheimer's Disease.

Protein N-glycosylation is ubiquitous in the brain and is closely related to cognition and memory. Alzheimer's disease (AD) is a multifactorial disorder that lacks a clear pathogenesis and treatment. Aberrant N-glycosylation has been suggested to be involved in AD pathology. However, the systematic variations in protein N-glycosylation and their roles in AD have not been thoroughly investigated due to technical challenges. Here, we applied multilayered N-glycoproteomics to quantify the global protein expression levels, N-glycosylation sites, N-glycans, and site-specific N-glycopeptides in AD (APP/PS1 transgenic) and wild-type mouse brains. The N-glycoproteomic landscape exhibited highly complex site-specific heterogeneity in AD mouse brains. The generally dysregulated N-glycosylation in AD, which involved proteins such as glutamate receptors as well as fucosylated and oligomannose glycans, were explored by quantitative analyses. Furthermore, functional studies revealed the crucial effects of N-glycosylation on proteins and neurons. Our work provides a systematic multilayered N-glycoproteomic strategy for AD and can be applied to diverse biological systems.

Dopamine D1 receptor-mediated upregulation of BKCa currents modifies Müller cell gliosis in a rat chronic ocular hypertension model.

Müller cell gliosis is a common response in many retinal pathological conditions. We previously demonstrated that downregulation of Kir channels contributes to Müller cell gliosis in a rat chronic ocular hypertension (COH) model. Here, the possible involvement of outward K+ currents in Müller cell gliosis was investigated. Outward K+ current densities in Müller cells isolated from COH rats, as compared with those in normal rats, showed a significant increase, which was mainly contributed by large-conductance Ca2+ -activated K+ (BKCa ) channels. The involvement of BKCa channels in Müller cell gliosis is suggested by the fact that glial fibrillary acidic protein (GFAP) levels were augmented in COH retinas when these channels were suppressed by intravitreal injections of iberiotoxin. In COH retinas an increase in dopamine (DA) D1 receptor (D1R) expression in Müller cells was revealed by both immunohistochemistry and Western blotting. Moreover, protein levels of tyrosine hydroxylase were also increased, and consistent to this, retinal DA contents were elevated. SKF81297, a selective D1R agonist, enhanced BKCa currents of normal Müller cells through intracellular cAMP-PKA signaling pathway. Furthermore, GFAP levels were increased by the D1R antagonist SCH23390 injected intravitreally through eliminating the BKCa current upregulation in COH retinas, but partially reduced by SKF81297. All these results strongly suggest that the DA-D1R system may be activated to a stronger extent in COH rat retinas, thus increasing BKCa currents of Müller cells. The upregulation of BKCa channels may antagonize the Kir channel inhibition-induced depolarization of Müller cells, thereby attenuating the gliosis of these cells.

Frontiers in poly(ionic liquid)s: syntheses and applications.

We review recent works on the synthesis and application of poly(ionic liquid)s (PILs). Novel chemical structures, different synthetic strategies and controllable morphologies are introduced as a supplement to PIL systems already reported. The primary properties determining applications, such as ionic conductivity, aqueous solubility, thermodynamic stability and electrochemical/chemical durability, are discussed. Furthermore, the near-term applications of PILs in multiple fields, such as their use in electrochemical energy materials, stimuli-responsive materials, carbon materials, and antimicrobial materials, in catalysis, in sensors, in absorption and in separation materials, as well as several special-interest applications, are described in detail. We also discuss the limitations of PIL applications, efforts to improve PIL physics, and likely future developments.

Novel rice mutants overexpressing the brassinosteroid catabolic gene CYP734A4.

KEY MESSAGE: Moderate overexpression of CYP734A4 improves grain number per main panicle and seed setting rate. Brassinosteroid (BR) homeostasis and signaling are crucial for plant growth and development. CYP734A genes encode cytochrome P450 monooxygenases that control the level of bioactive BRs by degrading BRs. However, fertile plants overexpressing CYP734As have not been reported in rice. Here, we isolated a novel semi-dominant mutant brd3-D, in which T-DNA was inserted approximately 4 kb upstream of the CYP734A4 gene (GenBank Accession AB488667), causing its overexpression. The mutant is characterized by dwarfism, small grains, and erect leaves and is less sensitive to brassinolide-induced lamina joint inclination and primary root elongation. However, increased grain number per main panicle and improved seed setting rate were also found in heterozygous brd3-D. To our knowledge, these traits have not been reported in other BR deficient mutants. Quantitative real-time PCR analysis indicated that phenotypic severity of the brd3-D mutant is positively correlated with the CYP734A4 transcription level. In accordance with the increased expression of CYP734A4, a lower castasterone (a rice BR) content was detected in the brd3-D mutants. Knockout of brd3-D by using the CRISPR/Cas9 system rescued the mutation. In addition, transgenic plants overexpressing CYP734A4 with the 35S enhancer mimicked the brd3-D phenotypes, confirming that moderate overexpression of the CYP734A4 gene can improve grain number per main panicle and the seed setting rate in rice. Further studies showed that overexpression of CYP734A4 influences the expressions of multiple genes involved in the BR pathway, and the expression of CYP734A4 is induced by exogenous brassinolide, confirming the negative regulatory role of CYP734A4 in the BR pathway. CYP734A4 might provide a useful gene resource for developing new high-yielding rice varieties.

[Cannabinoid receptor system regulates ion channels and synaptic transmission in retinal cells].

Endocannabinoid receptor system is extensively expressed in the vertebrate retina. There are two types of cannabinoid receptors, CB1 and CB2. Activation of these two receptors by endocannabinoids N-arachidonoylethanolamide (anandamine, AEA) and 2-arachidonyl glycerol (2-AG) regulates multiple neuronal and glial ion channels, thus getting involved in retinal visual information processing. In this review, incorporating our results, we discuss the modulation of cannabinoid CB1 and CB2 receptors on retinal neuronal and glial ion channels and retinal synaptic transmission.

Heteroatom-Containing Porous Carbons Derived from Ionic Liquid-Doped Alkali Organic Salts for Supercapacitors.

A simple strategy for the synthesis of heteroatom-doped porous carbon materials (CMs) via using ionic liquid (IL)-doped alkali organic salts as small molecular precursors is developed. Doping of alkali organic salts (such as sodium glutamate, sodium tartrate, and sodium citrate) with heteroatoms containing ILs (including 1-butyl-3-methylimidazolium chlorine and 3-butyl-4-methythiazolebromination) not only incorporates the heteroatoms into the carbon frameworks but also highly improves the carbonization yield, as compared with that of either alkali organic salts or ILs as precursors. The porous structure of CMs can be tuned by adjusting the feed ratio of ILs. The porous CMs derived from 1-butyl-3-methylimidazolium chlorine-doped sodium glutamate exhibit high charge storage capacity with a specific capacitance of 287 F g(-1) and good stability over 5000 cycles in 6 m KOH at a current density of 1 A g(-1) for supercapacitors. This strategy opens a simple and efficient method for the synthesis of heteroatom-doped porous CMs.

CO2 Responsive Imidazolium-Type Poly(Ionic Liquid) Gels.

Poly(ionic liquid) (PIL) gels with CO2 stimulus responsiveness have been synthesized through the copolymerization of an imidazolium-type ionic liquid monomer with 2-(dimethyl amino) ethyl methacrylate. Upon bubbling with CO2 gas, the prepared PIL solution is converted to a transparent and stable gel, which can be turned back to the initial solution state after N2 bubbling. The reversible sol-gel phase transition behavior is proved by the reversible values of viscosity and ionic conductivity. The possible mechanism for such a reversible sol-gel phase transition is demonstrated by NMR, conductivity, and rheological measurements.

Condiment-Derived 3D Architecture Porous Carbon for Electrochemical Supercapacitors.

The one-step synthesis of porous carbon nanoflakes possessing a 3D texture is achieved by cooking (carbonization) a mixture containing two condiments, sodium glutamate (SG) and sodium chloride, which are commonly used in kitchens. The prepared 3D porous carbons are composed of interconnected carbon nanoflakes and possess instinct heteroatom doping such as nitrogen and oxygen, which furnishes the electrochemical activity. The combination of micropores and mesopores with 3D configurations facilitates persistent and fast ion transport and shorten diffusion pathways for high-performance supercapacitor applications. Sodium glutamate carbonized at 800 °C exhibits high charge storage capacity with a specific capacitance of 320 F g(-1) in 6 m KOH at a current density of 1 A g(-1) and good stability over 10,000 cycles.

Calcium has a direct effect on thick filament activation in porcine myocardium.

Sarcomere activation in striated muscle requires both thin filament-based and thick filament-based activation mechanisms. Recent studies have shown that myosin heads on the thick filaments undergo OFF to ON structural transitions in response to calcium (Ca2+) in permeabilized porcine myocardium in the presence of a small molecule inhibitor that eliminated active force. The changes in X-ray diffraction signatures of OFF to ON transitions were interpreted as Ca2+ acting to activate the thick filaments. Alternatively, Ca2+ binding to troponin could initiate a Ca2+-dependent crosstalk from the thin filament to the thick filament via interfilament connections such as the myosin binding protein-C. Here, we exchanged native troponin in permeabilized porcine myocardium for troponin containing the cTnC D65A mutation, which disallows the activation of troponin through Ca2+ binding to determine if Ca2+-dependent thick filament activation persists in the absence of thin filament activation. After the exchange protocol, over 95% of the Ca2+-activated force was eliminated. Equatorial intensity ratio increased significantly in both WT and D65A exchanged myocardium with increasing Ca2+ concentration. The degree of helical ordering of the myosin heads decreased by the same amount in WT and D65A myocardium when Ca2+ concentration increased. These results are consistent with a direct effect of Ca2+ in activating the thick filament rather than an indirect effect due to Ca2+-mediated crosstalk between the thick and thin filaments.

A trispecific antibody induces potent tumor-directed T-cell activation and antitumor activity by CD3/CD28 co-engagement.

Aim: A novel CD19xCD3xCD28 trispecific antibody with a tandem single-chain variable fragments (scFv) structure was developed for the treatment of B-cell malignancies. Methods: The trispecific antibody in inducing tumor-directed T-cell activation and cytotoxicity was evaluated in vitro and in vivo and compared with its bispecific counterpart BiTE-CD19xCD3 lacking a CD28-targeting domain. Results: The trispecific antibody with a co-stimulatory domain exhibited augmented T-cell activation and memory T-cell differentiation capability and it induced faster tumor cell lysis than the bispecific antibody. RNAseq analysis revealed that the trispecific antibody modulates CD3/TCR complex-derived signal and upregulates antiapoptotic factors to influence the survival of T cells. Conclusion: By CD3/CD28 co-engagement, the trispecific antibody demonstrated its advantages in T-cell immunity and potential use as a more powerful and long-lasting T-cell engager.

T-cell based immunotherapies are a type of treatment that stimulates the body's own immune system to fight cancer. They have grown in popularity in recent years and have had impressive results in cancer treatment. One type of T-cell immunotherapy is a T-cell engager antibody. This is a type of molecule that redirects the body's immune cells to recognise and kill cancer cells. In this study, we developed a new type of T-cell engager antibody to treat two types of blood and bone marrow cancer. The antibody works by joining immune cells and cancer cells close together, to help activate the immune cells for cancer killing. This new type of T-cell engager antibody worked better than previous versions. It helped the immune cells survive longer and kill cancer more effectively. This means the new antibody might be better at treating people who have these types of cancers, but more testing in humans needs to be done.

Characterization and fine mapping of a novel rice narrow leaf mutant nal9.

A narrow leaf mutant was isolated from transgenic rice (Oryza sativa L.) lines carrying a T-DNA insertion. The mutant is characterized by narrow leaves during its whole growth period, and was named nal9 (narrow leaf 9). The mutant also has other phenotypes, such as light green leaves at the seedling stage, reduced plant height, a small panicle and increased tillering. Genetic analysis revealed that the mutation is controlled by a single recessive gene. A hygromycin resistance assay showed that the mutation was not caused by T-DNA insertion, so a map-based cloning strategy was employed to isolate the nal9 gene. The mutant individuals from the F2 generations of a cross between the nal9 mutant and Longtepu were used for mapping. With 24 F2 mutants, the nal9 gene was preliminarily mapped near the marker RM156 on the chromosome 3. New INDEL markers were then designed based on the sequence differences between japonica and indica at the region near RM156. The nal9 gene was finally located in a 69.3 kb region between the markers V239B and V239G within BAC OJ1212_C05 by chromosome walking. Sequence and expression analysis showed that an ATP-dependent Clp protease proteolytic subunit gene (ClpP) was most likely to be the nal9 gene. Furthermore, the nal9 mutation was rescued by transformation of the ClpP cDNA driven by the 35S promoter. Accordingly, the ClpP gene was identified as the NAL9 gene. Our results provide a basis for functional studies of NAL9 in future work.

HNF4A-BAP31-VDAC1 axis synchronously regulates cell proliferation and ferroptosis in gastric cancer.

B cell receptor associated protein 31 (BAP31) is closely associated with tumor progression, while the role and mechanism of BAP31 in gastric cancer (GC) remains unknown. This study explored that BAP31 was upregulated in GC tissues and high expression indicated poor survival of GC patients. BAP31 knockdown inhibited cell growth and induced G1/S arrest. Moreover, BAP31 attenuation increased the lipid peroxidation level of the membrane and facilitated cellular ferroptosis. Mechanistically, BAP31 regulated cell proliferation and ferroptosis by directly binding to VDAC1 and affected VDAC1 oligomerization and polyubiquitination. HNF4A was bound to BAP31 at the promoter and increased its transcription. Furthermore, knockdown of BAP31 inclined to make GC cells vulnerable to 5-FU and ferroptosis inducer, erastin, in vivo and in vitro. Our work suggests that BAP31 may serve as prognostic factor for gastric cancer and act as potential therapeutic strategy for gastric cancer.

L- and T-type Ca2+ channels dichotomously contribute to retinal ganglion cell injury in experimental glaucoma.

Retinal ganglion cell apoptotic death is the main pathological characteristic of glaucoma, which is the leading cause of irreversible blindness. Disruption of Ca2+ homeostasis plays an important role in glaucoma. Voltage-gated Ca2+ channel blockers have been shown to improve vision in patients with glaucoma. However, whether and how voltage-gated Ca2+ channels are involved in retinal ganglion cell apoptotic death are largely unknown. In this study, we found that total Ca2+ current densities in retinal ganglion cells were reduced in a rat model of chronic ocular hypertension experimental glaucoma, as determined by whole-cell patch-clamp electrophysiological recordings. Further analysis showed that L-type Ca2+ currents were downregulated while T-type Ca2+ currents were upregulated at the later stage of glaucoma. Western blot assay and immunofluorescence experiments confirmed that expression of the CaV1.2 subunit of L-type Ca2+ channels was reduced and expression of the CaV3.3 subunit of T-type Ca2+ channels was increased in retinas of the chronic ocular hypertension model. Soluble tumor necrosis factor-α, an important inflammatory factor, inhibited the L-type Ca2+ current of isolated retinal ganglion cells from control rats and enhanced the T-type Ca2+ current. These changes were blocked by the tumor necrosis factor-α inhibitor XPro1595, indicating that both types of Ca2+ currents may be mediated by soluble tumor necrosis factor-α. The intracellular mitogen-activated protein kinase/extracellular signal-regulated kinase pathway and nuclear factor kappa-B signaling pathway mediate the effects of tumor necrosis factor-α. TUNEL assays revealed that mibefradil, a T-type calcium channel blocker, reduced the number of apoptotic retinal ganglion cells in the rat model of chronic ocular hypertension. These results suggest that T-type Ca2+ channels are involved in disrupted Ca2+ homeostasis and apoptosis of retinal ganglion cells in glaucoma, and application of T-type Ca2+ channel blockers, especially a specific CaV3.3 blocker, may be a potential strategy for the treatment of glaucoma.

Label-free electrochemical immunosensor based on staphylococcal protein a and AgNPs-rGO-Nf for sensitive detection of virginiamycin M1.

Virginiamycin (VIR), a feed additive, is used to promote pig and poultry growth. However, it is hazardous to human health. This work described a label-free electrochemical immunosensor based on silver nanoparticles-reduced graphene oxide (AgNPs-rGO) nanocomposites and staphylococcal protein A (SPA) for the first time to directly detect the residual marker VIR M1. Good catalytic currents for oxygen reduction reaction were apparently obtained after the modification of nanocomposites on gold electrode. Nanocomposites were characterized using UV-Vis, X-ray diffraction (XRD) patterns, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). SPA was targeted to immobilize VIR M1 monoclonal antibody (mAb) by binding to Fc region of antibody. The proposed immunosensor showed a wide linear range from 0.25 ng mL-1 to 100 ng mL-1, providing detection limit (LOD) of 0.18 ng mL-1 of VIR M1. Recovery rates ranged from 92.27% to 98.84%, and relative standard deviation (RSD) was not above 6.6%, indicating the immunosensor could detect VIR M1 in actual samples with high accuracy. The sensor showed good selectivity, reproducibility and stability and could be considered as a potential tool for detection of VIR M1 in feed and animal derived food.

Analysis of virginiamycin M1 in swine feed, muscle and liver samples by quantum dots-based fluorescent immunochromatographic assay.

Based on a highly sensitive and specific monoclonal antibody (mAb) against virginiamycin M1 (VIR M1), a quantum dots-based fluorescent immunochromatographic assay (QDs-ICA) for quick and sensitive analysis of VIR M1 was established for the first time. The mAb showed a half-maximal inhibitory concentration (IC50) of 0.5 ng/mL and cross-reactivity (CR) values below 0.1% for other three analogues when used in enzyme-linked immunosorbent assay (ELISA). The mAb was conjugated to ZnCdSe/ZnS (core/shell) QDs with maximum emission wavelength of 610 nm (orange-red) which was selected as fluorescent probe to increase QDs-ICA sensitivity. The cut-off value of QDs-ICA was 12.5 ng/mL. QDs-ICA showed a linear range from 0.7 to 14.5 ng/mL with a limit of quantification of 0.7 ng/mL. Compared with existing methods for the analysis of VIR M1, the QDs-ICA exhibited higher sensitivity. For analysis of VIR M1 concentrations spiked into swine feed, muscle and liver samples, recovery rates ranged from 94.0% to 111.6% with the highest coefficient of variation (CV) of 6.7% for intra-assay, and for inter-assay ranged from 94.7% to 107.6% with the highest CV of 9.4%. In conclusion, the QDs-ICA could be a potential method for analyzing VIR M1 in animal feed and animal-derived food.

Sub-20-nm anatase TiO2 anchored on hollow carbon spheres for enhanced photocatalytic degradation of reactive red 195.

Herein, hollow carbon sphere (HCS)-supported titanium dioxide (TiO2) nanoparticles (sub-20-nm; HCS@TiO2)-based composites are rationally designed and fabricated via a facile wet-chemistry strategy. The introduction of an HCS, which acts as a conductive substrate, improves the separation efficiency of photogenerated hole/electron pairs (h+/e-) from TiO2 because photogenerated electrons are transferred to conductive carbon skeleton. Due to the three-dimensional spherical structure and excellent hydrophilicity of the carbon skeletons, low-density HCS with outstanding conductivity not only accelerate the separation of photogenerated h+/e- pairs from TiO2 but also improve the adsorption performance of the soluble reactive red 195 molecules (RR195) on the surface of TiO2 nanoparticles. These properties of HCS@TiO2 composites enable efficient photocatalytic degradation of RR195. The obtained results indicated that HCS@TiO2 composites (80 wt% TiO2) achieved the best photocatalytic degradation performance with higher photodegradation rate of 97% than pure TiO2 nanoparticles (86%). This study offers a new pathway for the design and preparation of novel photocatalysts to achieve efficient degradation of degrading organic pollutants.

Recent Advances in Oxidation Stable Chemistry of 2D MXenes.

As an emerging star of 2D nanomaterials, 2D transition metal carbides and nitrides, named MXenes, present a large potential in various research areas owing to their intrinsic multilayer structure and intriguing physico-chemical properties. However, the fabrication and application of functional MXene-based devices still remain challenging as they are prone to oxidative degradation under ambient environment. Within this review, the preparation methods of MXenes focusing on the recent investigations on their thermal structure-stability relationships in inert, oxidizing, and aqueous environments are systematically introduced. Moreover, the key factors that affect the oxidation of MXenes, such as, atmosphere, temperature, composition, microstructure, and aqueous environment, are reviewed. Based on different scenarios, strategies for avoiding or delaying the oxidation of MXenes are proposed to encourage the utilization of MXenes in complicated environments, especially at high temperature. Furthermore, the chemistry of MXene-derived oxides is analyzed, which can offer perspectives on the further design and fabrication of novel 2D composites with the unique structures of MXenes being preserved.