Latest ArticlesCardiovascular disease (CVD) is a global health problem and is thought to be responsible for almost half of all deaths in the world. Nevertheless, currently available diagnostic methods for CVD are strongly depended on clinical observation and monitoring, which commonly result in false diagnosis. Herein, an attractive strategy of a metal-organic framework (MOF) nanofilm-based laser desorption/ionization mass spectrometry (LDI-MS) was developed for enhancing serum metabolic profiling, which could provide precise diagnosis and molecular subtyping of CVD. The porous MOF nanofilm fabricated on indium-tin oxide (ITO) glass possessed enhanced ionization efficiency and size-exclusion effect, which endowed it as substrate with high sensitivity and selectivity for serum metabolites. Furthermore, the MOF nanofilm with uniform surface and high orientation provided high-quality and high-reproducibility serum metabolic profiles (SMPs) without any tedious pretreatment. Further analysis of extracted serum metabolic fingerprints could successfully distinguish patients with CVD from healthy controls and also differentiate two major subtypes of CVD. This work not only extends the application of MOF nanofilm as an attractive MS probe, but also provide an alternative way for precise diagnosis of CVD in molecular level.
Benzimidazole amino acid derivatives behave as supramolecular hosts to include organic acids via complementary hydrogen bonding whereby supramolecular chirality and chiroptical properties could be manipulated. Organic acids enhanced the chiral assembly that showed tunable circularly polarized luminescence with high dissymmetry g-factors at 10-2 grade.
Developing an efficient Zn-based catalyst modified with Trifluoromethanesulfonic acid (TfOH) ligand is extremely desirable for the acetylene hydration reaction. In this paper, with the use of a simple impregnation method, a series of Zn-TfOH/AC catalysts were synthesized, and the Zn-1.5TfOH/AC catalyst demonstrated the optimal catalytic performance with 96% acetylene conversion in the hydration of acetylene. The X-ray absorption fine structure (XAFS) spectra of the fresh Zn-1.5TfOH/AC catalysts demonstrated the establishment of the Zn-O4 coordination structure. According to the characterization results, TfOH ligands effectively inhibited carbon accumulation and Zinc loss, improved acidic sites and the dispersion of active metal, and produced more catalytic active site. Furthermore, the hydration reaction mechanism of Zn-TfOH/AC catalyst with Zn(OTf)2, TfO-ZnCl, and TfO-ZnOH complex configurations was explored by the Density Functional Theory (DFT) method, which showed that the activation barrier increased sequentially TfO-ZnOH < Zn(OTf)2 < TfO-ZnCl. Importantly, the OH− in TfO-ZnOH is involved in the reaction and regenerated by the dissociation of H2O, which lowers the energy barrier. This will provide a reference to design more efficient nonmercury catalysts for acetylene hydration.
The application of fluorescent probes for in vivo retinal imaging is of great importance, which could provide direct and crucial imaging evidence for a better understanding of common eye diseases. Herein, a group of bright organic luminogens with typical electron-donating (D) and electron-accepting (A) structures (abbreviated as LDs-BDM, LDs-BTM, and LDs-BHM) was synthesized through a simple single-step reaction. They were found to be efficient solid-state emitters with high fluorescence quantum yields of above 70% (e.g., 83.7% for LDs-BTM). Their light-emission properties could be tuned by the modulation of π-conjugation effect with methoxy groups at different substituent positions. Their resulting fluorescent nanoparticles (NPs) were demonstrated as specific lipid droplets (LDs) targeting probes with high brightness, good biocompatibility, and satisfactory photostability. LDs-BTM NPs with a large two-photon absorption cross section (σ2 = 249 GM) were further utilized as ultrabright two-photon fluorescence (2PF) nanoprobes for in vivo retina imaging of live zebrafish by NIR excitation at an ultralow concentration (0.5 µmol/L). Integrated histological structures at the tissue level and corresponding fine details at the cellular level of the embryonic retina of live zebrafish were clearly demonstrated. This is the first report of using ultrabright LDs-targeting nanoprobes to accurately measure fine details in the retina with 2PF microscopic technique. These good results are anticipated to open up a new avenue in the development of efficient 2PF emitters for non-invasive bioimaging of living animals.
Carbon materials derived from biomass waste are considered as potential electrocatalysts for applications in zinc-air batteries (ZABs) due to their low cost and good catalytic activity. Here, we reported the preparation of gel-based catalysts through utilizing hydrolyzed waste leather powder cross-linked with metallic salt solutions. After calcination, iron-nickel alloy anchored in nitrogen-doped porous carbon catalysts (FeNi@NDC) was achieved. Compared with commercial Pt/C catalyst, FeNi@NDC-800 exhibited lower E1/2 (0.77 V) and better durability. More importantly, the resulting FeNi@NDC-800-based alkaline ZABs achieved power density of 93.01 mW/cm2 and open circuit voltage of 1.45 V, which the FeNi@NDC-800-based neutral ZAB displayed a charge/discharge cycle stability of 275 h. This work opens up the possibility of rational design and preparation of low-cost and high-performance electrocatalysts from recyclable leather waste.
The biocompatibility and biodegradability of peptide self-assembled materials makes them suitable for many biological applications, such as targeted drug delivery, bioimaging, and tracking of therapeutic agents. According to our previous research, self-assembled fluorescent peptide nanoparticles can overcome the intrinsic optical properties of peptides. However, monochromatic fluorescent nanomaterials have many limitations as luminescent agents in biomedical applications. Therefore, combining different fluorescent species into one nanostructure to prepare fluorescent nanoparticles with multiple emission wavelengths has become a very attractive research area in the bioimaging field. In this study, the tetrapeptide Trp-Trp-Trp-Trp (WWWW) was self-assembled into multicolor fluorescent nanoparticles (TPNPs). The results have demonstrated that TPNPs have the blue, green, red and near infrared (NIR) fluorescence emission wavelength. Moreover, TPNPs have shown excellent performance in multicolor bioimaging, biocompatibility, and photostability. The facile preparation and multicolor fluorescence features make TPNPs potentially useful in multiplex bioanalysis and diagnostics.
As a strong oxidizer, hypochlorite (ClO–) are widely employed as bleaching agents and disinfectants. Determination of ClO– is required to ensure bactericidal effects and avoid hazards caused by excessive residual chlorine. Herein, the derivative bicyclic 2-pyridone, namely DHIP-Py, was prepared successfully to establish a new ClO–-quantitative method. The probe exhibits excellent ClO– selectivity over other ROS and anions/cations, high sensitivity (LOD = 1.32 µmol/L), fast response (<5 s), and wide-pH tolerance (pH 4~10). Benefit from its good water solubility, DHIP-Py is well suited for water sample analysis and has been successfully applied to detect ClO– in real-world food and environmental samples, including tap water, bottled water and river water. The detection results were essentially identical to that of obtained from traditional DPD method. Moreover, visual detection of ClO– via filter paper-based solid sensor and imaging of ClO– in Escherichia coli were also achieved by DHIP-Py. These satisfactory results demonstrate that this bicyclic 2-pyridone-based hypochlorite probe is a promising free chlorine chemosensor with great potential for analytical applications.
As a high-flux operation mode of thin film composite-forward osmosis (TFC-FO) membrane, active layer facing draw solution (AL-DS) mode suffers from the severe membrane fouling tendency, which is not addressed well. Here, we introduced a photocatalyst (Anatase titanium dioxide, A-TiO2) onto the support layer of TFC-FO membrane via the bonding of polydopamine (PDA) and polytetrafluoroethylene (PTFE), and prepared two photocatalytic membranes, A-TiO2/PDA@TFC and A-TiO2/PTFE@TFC. Compared with the pristine TFC-FO membrane, both A-TiO2/PDA @TFC and A-TiO2/PTFE@TFC had an improved water permeability (10.5 L m−2h−1 and 9.5 L m−2 h−1, respectively) and reduced reverse NaCl flux salt (0.8 g m−2 h−1 and 0.7 g m−2 h−1, respectively) in the AL-DS mode using 1 mol/L NaCl as draw solution and pure water as feed solution. Moreover, in the 16 h fouling experiment using 200 ppm bovine serum albumin (BSA) solution as a representative pollutant, the flux decline rate of both photocatalytic membranes was dramatically alleviated from 39.7% and 21.7% in the darkness to 8.5% and 9.7% under UV irradiation, respectively, indicating a significant anti-fouling capacity of photocatalytic effect. In all, the presence of A-TiO2 endowed membrane with high permeability, high rejection efficiency and excellent anti-fouling capacity under UV spotlight. As bonding agent, PTFE provided the modified membrane with a high photocatalytic effect and high self-cleaning capacity, while PDA increased the membrane permeability and protected membrane against photocatalytic damage. This work provides a simple and feasible method to improve the anti-fouling capacity of TFC-FO membrane in AL-DS mode.
Proteolysis targeting chimeras (PROTACs) are bifunctional degrader molecules via hijacking the ubiquitin-proteasome system (UPS) to specifically eliminate targeted proteins. PROTACs have gained momentum as a new modality of attractive technologies in the drug discovery landscape, since it allows to degrade disease-related proteins effectively. Although some PROTACs drugs reached the clinical research, they are still facing some bottlenecks and challenges that should not be neglected, such as poor oral bioavailability and potential toxic side effects. To overcome these limitations, herein, we provide an overview of recent strategies for improving the durability of PROTACs by enhancing cell permeability and reducing toxic side effects. Meanwhile, the impact of these strategies on improving oral bioavailability as well as their advantages and drawbacks will also be discussed. This review will give a useful reference toolbox for PROTACs design and further promote its clinical application.
Increasing the charging cut-off potential of lithium cobalt oxide (LiCoO2, LCO) can effectively improve the energy density of the lithium-ion batteries, which are the mainstream energy storage devices used in 3C electronic products. However, the continuous decomposition of the electrolyte and dissolution of Co from the electrode will occur at high-potential operation, which deteriorate the performances of LCO. Here, a cathode-electrolyte interface (CEI) layer containing MgF2 is constructed to enhance the electrochemical stability of LCO at 4.6 V (vs. Li+/Li). The Mg2+ added to the cathode gradually releases into the electrolyte during cycling, which forms a stable MgF2-rich protective layer. In addition, 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (TTE) is added to the electrolyte acting as a F source to increase the content of MgF2 in the CEI layer. The MgF2-rich CEI layer effectively suppresses the decomposition of electrolyte components and the dissolution of Co of LCO, which makes the Li||LiCoO2 (Li||LCO) cell cycled stably at 3~4.6 V (vs. Li+/Li) in 200 cycles with a retention of 83.9%.