Search

Bioorthogonal chemistry enables researchers to manipulate bioactive molecules in living systems. These highly selective and biocompatible reactions can be carried out in various complex environments. Over the past two decades, a considerable number of strides have been made to expand the capacities of bioorthogonal chemistry coupled with the aim to fine-tune present reactions for specific applications. The good points of bioorthogonal chemistry have pushed material chemists to integrate bioorthogonal chemistry with nanotechnologies to broaden the biological applications of nanomaterials. Notably, bioorthogonal nanotechnologies fundamentally rely on, more than half, according to our investigation, tetrazine bioorthogonal chemistry (TBC) to function as bioorthogonal handles to react with target agents owing to the extremely rapid kinetics and high selectivities of TBC. Its utilization in combination with nanotechnologies has led to developments in various areas of biomedicine, such as

Background: The zinc finger E-box binding homeobox (ZEB2), which can accelerate the nuclear DNA replication by inducing the activation of upstream transcription promoters, was widely considered as an oncogene. Recent study has found that the overexpression of ZEB2 is associated with a better prognosis in hepatocellular carcinoma. However, its roles in tumor growth, metastasis, and immunology are yet to be elucidated in COAD. Methods: The pan-cancer sequencing data was acquired from The Cancer Genome Atlas (TCGA)-Pan cancer cohort, normal human tissue data was acquired from the Genotype-tissue expression (GTEx) database, and Broad Institute Cancer Cell Line Encyclopedia (CCLE) were downloaded from UCSC Xena. We used the cBioPortal webtool to analyze and visualize the ZEB2 pan-cancer genomic alteration rate. GEO Expression Datasets were used to explore ZEB2 expression levels in COAD patients. UCSC Xena database was used to download prognostic information of COAD patients. The Cox regression and Kaplan–Meier analyses were used to assess the prognostic role of ZEB2 in COAD. Kyoto Encyclopedia of Genes and Genomes (KEGG) was performed to determine the biological pathways. Gene Ontology (GO) enrichment analysis was performed to determine the biological processes, molecular functions, and cellular components that were altered in a ZEB2-dependent manner in COAD. The module analysis of PPI interaction network was performed using the MCODE tool of Cytoscape software, and the characteristic molecules were selected by cytohHubba tool. CIBERSORTx database was used to analyze the ZEB2 expression in the presence of 22 types of immune infiltrating cells. Results: This study found that ZEB2 was aberrantly expressed in most cancer types, and it was significantly downregulated in COAD compared with normal tissue. In addition, our findings also show that overexpression of ZEB2 was associated with a better prognosis in COAD. Mechanistic analysis revealed that overexpression of ZEB2 was associated with the neutrophil extracellular trap formation in COAD. And the results show that ZEB2 expression was significantly correlated with several kinds of immune cell infiltration. Conclusion: This study demonstrates that overexpression of ZEB2 was associated with better prognoses in patients with COAD. ZEB2 has close relationship with ACTB, which was highly related to NETs. These findings suggest a dual role of ZEB2 in COAD growth, metastasis, and immunology.

Polyetheretherketone (PEEK) has been considered as an excellent orthopedic implant material due to its similar elastic modulus to that of human bones. However, many obstacles including the bio-inertness nature and inferior osteoconduction of PEEK limit its wide applications in clinics. Nano hydroxyapatite (HA) and zirconium dioxide (ZrO2) were incorporated into PEEK to fabricate HA/ZrO2/PEEK biocomposites. The result of wettability of these biocomposites showed that the introduction of the ZrO2 and HA nanoparticles in PEEK could enhance its hydrophilic property at 1–2% HA and 1–5% ZrO2 concentrations. The biotribological properties and bioactivity of PEEK and HA/ZrO2/PEEK biocomposites were investigated in detail. The friction coefficient of these biocomposites increased with the increase of frequency and their wear width increased obviously with the increase of load. Biological and tribological experiments indicated that bovine serum possessed the best lubrication performance, and the 1%HA–1%ZrO2 and 2%HA–5%ZrO2 samples exhibited the lowest friction coefficient and wear rate. Then, the in vitro tests demonstrated that the HA/ZrO2/PEEK biocomposites exhibited improved cell activity and alkaline phosphatase activity than pure PEEK, and both 1%HA/1%ZrO2/PEEK and 2%HA/5%ZrO2/PEEK biocomposite samples could better promote bone calcification. The PEEK biocomposite with 2 wt% HA and 5 wt% ZrO2 nanoparticles exhibited the best tribological properties and bioactivity, which could be expected to develop a kind of potential medical material for practical clinical applications.

Au/XC-72 nanoparticles prepared via microwave-assisted polyol processes were used as the active materials for methimazole detection. The Au/XC-72 modified electrode shows an excellent catalytic activity toward oxidation of methimazole, the cyclic voltammetry of methimazole displays two pairs of well-defined, quasi-reversible redox peaks. The oxidation of methimazole on Au/XC-72 modified electrode is a diffusion-controlled and a one-electron transfer process. The fixed-potential amperometry technique was used for the determination of methimazole and a linear dependence of anodic current on methimazole concentration was obtained in the range of 19.9–100.91 μM.

The Li7La3Zr2O12-based garnet (LLZO-BG) electrolyte has the advantage of strong thermal stability and can, therefore, avoid the flammability problem of organic electrolyte solutions. However, the solid-state lithium battery with LLZO-BG electrolyte has a much larger electrochemical resistance and poorer performance than the battery with an organic electrolyte solution, which is mainly related to the electrolyte/electrode interface. From the perspective of the LLZO-BG/Li interface, this review explores several interrelated interfacial issues, including the air instability of LLZO-BG, poor LLZO-BG/Li interfacial contact, easily generated lithium dendrite and the instability of LLZO-BG with the Li anode. We elaborate on the forming mechanisms, affecting factors and measures for improving these issues, and prospects for the future research directions of the LLZO-BG/Li interface. This review can provide new ideas for producing a solid-state lithium battery with high safety and high energy density.

The synthesis of shape-controlled nanoparticles has attracted wide attention in recent years due to their tunable properties along with various morphologies. CsxWO3 is a great candidate for application in solar filters based on its high transmittance in the visible region and excellent shielding performance in the near-infrared (NIR) region. However, the relationship between NIR absorption performance and different shaped CsxWO3 particles has been rarely reported. In this paper, two-dimensional (2D) Cs0.3WO3 nanosheets, one-dimensional (1D) Cs0.3WO3 nanofibers and zero-dimensional (0D) Cs0.3WO3 nanoparticles were successfully synthesized via a simple hydrothermal approach, and the related photoresponse properties were also investigated. The results show that the 2D nanosheets present much stronger absorption in the wavelength range of 300–20 000 nm as compared to the 1D nanofibers and 0D nanoparticles. Under 10 s of continual irradiation by a 50 W halogen lamp, the peak temperature of the 1D nanofibers and 0D nanoparticles increased from 20 °C to 73.2 °C and 63.8 °C, which are only 53.2 °C and 43.8 °C temperature gains, respectively. For the 2D nanosheets the peak temperature reached to 88.5 °C, which is about 68.5 °C temperature gain, almost 56% and 29% higher than that of the 0D nanoparticles and 1D nanofibers, respectively. The highest adiabatic temperature difference between the blank quartz glass and 2D Cs0.3WO3 nanosheets coated on the quartz glass was 9.2 °C. The photothermal conversion efficiency of the 2D, 1D and 0D samples was about 43.2%, 27.6% and 24.4%, respectively. These results indicate that the 2D Cs0.3WO3 sample is an effective NIR absorption and photothermal conversion material that can be used for NIR shielding, and also has great potential in biomedical applications.

Mitochondria has been identified as a target for tumor therapy. Agents preferentially concentrated in mitochondria may exert more potent antitumor effects by interfering with the normal function of mitochondria. Glutathione reductase (GR) in mitochondria is a crucial antioxidant enzyme to maintain mitochondrial function, and has been recognized as an important target for the development of anticancer drugs. Herein, we present a triphenylphosphonium-modified anticancer agent, MT-1, which can preferentially accumulate in mitochondria and bind to GR by covalent binding manner. As a result, morphology and function of mitochondria were severely damaged, as well as cellular energy supply was severely impeded due to the simultaneously inhibition against mitochondrial respiration and glycolysis. Moreover, MT-1 was found to bind to a completely new site of GR (C278) that has never considered as binding site of inhibitors before. This new binding mode led to the change of GR structure, which affected the stability of the transition state of the catalytic process, and finally led to the inhibition of GR activity. Thus, current study provided a potentially novel tumor therapeutic strategy by targeting novel sites of GR in mitochondrion.

Finding novel anti-diabetic compounds with effective suppression activities against hepatic glucagon response is urgently required for the development of new drugs against diabetes. Fungi are well known for their ability to produce new bioactive secondary metabolites. As part of our ongoing research, five new indole-terpenoids (

The carbon fibers (CFs) reinforced polytetrafluoroethylene (PTFE) composites have been modified using proton irradiation, and the surface energy, hardness and tribological properties have been investigated before and after irradiation. The CFs increased the hardness and the wear resistance. Proton irradiation led to defluorination and carbonization of the CF/PTFE composite surface, and decreased the surface wettability and the surface energy. The irradiation depth was 820 nm from the material surface calculated with SRIM software package. In addition, the wear resistance was improved after proton irradiation. Proton irradiation improved the wear resistance of the composite and induced the material transfer from Cu alloy surface to CF/PTFE. These significant improvements could enable potential applications in aeronautics and smart medical materials.

Five new perylenequinone derivatives, altertoxins VIII–XII (1–5), as well as one known compound cladosporol I (6), were isolated from the fermentation broth of the marine-derived fungus Cladosporium sp. KFD33 from a blood cockle from Haikou Bay, China. Their structures were determined based on spectroscopic methods and ECD spectra analysis along with quantum ECD calculations. Compounds 1–6 exhibited quorum sensing inhibitory activities against Chromobacterium violaceum CV026 with MIC values of 30, 30, 20, 30, 20 and 30 μg/well, respectively.

In this paper, 2 kinds of commercial perfluoropolyether (PFPE) greases were coated on the polyimide (PI) blocks, which were placed within simulated space environment including atomic oxygen (AO), proton (Pr), ultraviolet (UV), and electron (El) irradiations, and then the tribological performance has been investigated with a ball-on-disc tribometer. Results indicated that the MoS2-grease showed better lubrication performance than the PTFE-grease. The changes in infrared spectroscopy induced by Pr and El irradiations were more obvious than that by AO and UV irradiations. Results of energy dispersive X-ray spectroscopy indicated that Pr and El irradiations caused carbonation of greases, and AO and UV irradiations induced oxidation of greases. Referred to the tribological properties of PI coated with PFPE oil, PI coated with PFPE greases showed minor changes in friction coefficient and wear rate, and the MoS2 additives could significantly improve the lubrication properties of PFPE greases in simulated space environment.

The construction and management of airport asphalt pavement project has the characteristics of large construction scale, high technology, many professionals involved, and high quality requirements. The traditional monitoring and management method that relies on manual on-site inspections and records is vulnerable to many factors such as environmental conditions and the ability of the implementer. It is difficult to ensure real-time monitoring of construction quality and data backtracking. With the rapid development of various advanced technologies such as global navigation satellite system(GNSS), geographic information system(GIS) and internet of things(IoT), digital construction monitoring and management technology for airport asphalt pavement has emerged as the times require. Digital construction technology is implemented through professional testing equipment, data collection, data integration, and system installation. It covers the entire construction process of airport asphalt pavement from the background management of the mixing plant, the transportation management of vehicles to the field management of paving and compaction. The technology monitors the construction quality, guarantees the construction progress, improves management efficiency, and saves costs, which has great social and economic benefits.

Four polyene macrolactams including the previously reported niizalactam C (4), and three new ones, streptolactams A&ndash, C (1&ndash, 3) with a 26-membered monocyclic, [4,6,20]-fused tricyclic and 11,23-oxygen bridged [14,16]-bicyclic skeletons, respectively, were isolated from the fermentation broth of the deep-sea sediment-derived Streptomyces sp. OUCMDZ-3159. Their structures were determined based on spectroscopic analysis, X-ray diffraction analysis, and chemical methods. The abiotic formation of compounds 2 and 4 from compound 1 were confirmed by a series of chemical reactions under heat and light conditions. Compounds 1 and 3 showed a selective antifungal activity against Candida albicans ATCC 10231.

Pd–Au porous foam films with three-dimensional hierarchical pores consisting of interconnected dendrite walls are obtained by using the hydrogen bubble dynamic template. The films are characterized by scanning electron microscope, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, as well as electrochemical techniques. The CV curves have confirmed that the Pd–Au catalysts have high catalytic activity toward methanol oxidation. The catalytic activities of these Pd–Au catalysts are strongly dependent on the atomic ratio of Pd/Au. Among all the Pd–Au catalysts, the Pd 1 Au 1 catalyst is found to possess superior catalytic activity and stability toward methanol oxidation.

With the dramatic increase of air traffic volume and the rapid development of civil aviation airport construction in China, asphalt layers overlaying original concrete pavement in civil aviation airports has become the primary rehabilitation scheme. However, asphalt airport pavement is prone to excessive deformation when subjected to the repeated and heavy aircraft loading, especially when coupled with high-temperature field. However, the impact of high-temperature jet wake is rarely considered in the existing structural design and analysis of airport asphalt pavement. In order to investigate the impact of high-temperature jet wake on the dynamic response of asphalt pavement, the coupling of finite element (FE) simulation of the temperature field and aircraft loading based on sequential decoupling methodology was implemented herein. Firstly, the temperature field distribution induced by the high-temperature jet wake on the asphalt pavement was simulated and analyzed by FE simulation on the ABAQUS CFD platform. Then, the temperature field distribution was integrated within the asphalt pavement structure by combining the temperature field distribution produced by jet wake and thermal conduction between ambient radiation and pavement. Secondly, the viscoelastic parameters of each asphalt layer under the obtained temperature field distribution were calculated to represent more real material properties. Finally, FE simulation of airport asphalt pavement subjected to the coupling of aircraft loading and integrated temperature field was conducted. The results show that the amplitudes of transverse strain, vertical strain, and longitudinal strain of the asphalt pavement considering jet wake together with ambient radiation are basically higher than those without consideration. Consequently, the dynamic responses of airport asphalt pavement produced by jet wake and ambient radiation should be fully considered in the design and analysis of airport asphalt pavement.

The self-propelled diffusiophoresis, induced by an asymmetric concentration gradient field, provides a new strategy to manipulate micro-objects (like some cells and colloids) in solutions. One example is the autonomous motion of the double-faced Janus microparticle (platinum coating on one half of a silica particle) due to a chemically catalyzed reaction (reduction of hydrogen peroxide) on the Pt surface. In this paper, a systematic method is developed to describe the details of self-propulsion and rotation of Janus microparticles, despite the difficulty induced by particle non-uniformity. From the measurement, we found that the particles presented a three-stage behavior of the dimensionless mean square displacement, and their displacement probability distribution formed a double-peaked structure. These results show the intrinsic characteristics and the non-Gaussian behavior of Janus particle’s self-propulsion. Furthermore, the rotational motion is characterized by the rotational angle variation and the rotational diffusion coefficient. These results show that Brownian rotation still dominates the Janus microparticle’s rotational motion, though the measured rotational diffusion coefficient presents an anomalous tendency.

Accumulating evidences have reported that caffeine has anticancer effects at high blood concentrations. However, whether caffeine has anticancer effects on human hepatocellular carcinoma (HCC) cells at low concentration, especially at physiologically applicable concentration (< 412 μM) is still not well understood. In this study, HCC cell lines HepG2 and Huh7 were used. The cells were incubated with varying concentrations of caffeine (0, 50, 100, 200, 400 or 600 μM). MTT assay was used to investigate the proliferation ability in vitro. Migration and invasion abilities were determined by wound healing assay and transwell assay. The molecular changes were detected by western blot. An ectopic nude mice model which the mice were gavaged with caffeine was used to reveal the anticancer effects of caffeine on HepG2 cells in vivo. Results showed that caffeine could inhibit the proliferation, migration and invasion significantly at physiologically applicable concentration in vitro. Also the associated molecular changes of cancer progression were observed. In animal experiment, the mice gavaged with caffeine also performanced reduced tumor burden in vivo. Moreover, the interrelated protein expression was also observed in vivo which was coincident with the results in vitro. All in all, this observation indicated that caffeine may suppress the progression of HCC through Akt signaling pathway. This makes caffeine a potential candidate for treating HCC which will be a safer and more effective treatment by giving for a long time at physiologically applicable concentration.

Eighteen new compounds named aspergones A–Q (1–17) and 6-O-demethylmonocerin (18), along with five known analogues (19–23), were isolated from the fermentation broth of Aspergillus sp. OUCMDZ-1583 associated with an unidentified marine sponge (XD10410) from the Xisha Islands of China. The structures, including the absolute configurations, were unambiguously elucidated by spectroscopic, X-ray crystallographic, chemical, and Mosher’s methods along with quantum ECD calculations. Compounds 1, 2, 5, 10, 11, 14–18, and 21–23 showed α-glucosidase inhibition with IC50 values of 2.36, 1.65, 1.30, 2.37, 2.70, 1.36, 1.54, 2.21, 2.26, 0.027, 1.65, 1.19 and 1.74 mM, respectively (with acarbose as the positive control; IC50 = 0.95 mM), among which compound 18 is 35 times more potent than acarbose. In addition, compounds 18 and 21 exhibited inhibitory activity against the influenza A (H1N1) virus with IC50 values of 172.4 and 175.5 μM, respectively (with ribavirin as the positive control; IC50 = 137.3 μM).

Cyanogramide (1), an unprecedented alkaloid bearing a novel spirocyclic pyrrolo[1,2-c]imidazole skeleton, was identified from the fermentation broth of the marine-derived Actinoalloteichus cyanogriseus WH1-2216-6. The structure was fully determined by spectroscopic analysis, an exciton chirality CD method, and quantum mechanical calculations. Cyanogramide (1) could efficiently reverse the adriamycin-induced resistance of K562/A02 and MCF-7/Adr cells, and the vincristine-induced resistance of KB/VCR cells at a concentration of 5 μM, with the reversal fold values of 15.5, 41.5, and 9.7, respectively.

Penicillium sp. WC-29-5 was co-cultured with Streptomyces fradiae 007 to produce five natural products (1–3, 4a and 4b) that were isolated and characterized by spectroscopic analysis. Interestingly, these compounds were found to be different from those produced in discrete fungal and bacterial controls. Among these compounds, the absolute configurations of compounds 4a and 4b were determined for the first time by X-ray single crystal diffraction experiments and electronic circular dichroism (ECD) calculations. An evaluation of the cytotoxic activities of these compounds revealed that 4b was moderately cytotoxic towards HL-60 and H1975 tumor cells with IC50 values of 3.73 and 5.73 µM, respectively, whereas compound 4a was only moderately cytotoxic towards H1975 cells with an IC50 value of 3.97 µM.

A new alkaloid, 2-(furan-2-yl)-6-(2S,3S,4-trihydroxybutyl)pyrazine (1), along with 12 known compounds, 2-(furan-2-yl)-5-(2S,3S,4-trihydroxybutyl)pyrazine (2), (S)-4-isobutyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (3), (S)-4-isopropyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (4), (4S)-4-(2-methylbutyl)-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (5), (S)-4-benzyl-3-oxo-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbaldehyde (6), flazin (7), perlolyrine (8), 1-hydroxy-β-carboline (9), lumichrome (10), 1H-indole-3-carboxaldehyde (11), 2-hydroxy-1-(1H-indol-3-yl)ethanone (12), and 5-(methoxymethyl)-1H-pyrrole-2-carbaldehyde (13), were isolated and identified from the fermentation broth of an endophytic actinomycetes, Jishengella endophytica 161111. The new structure 1 and the absolute configurations of 2–6 were determined by spectroscopic methods, J-based configuration analysis (JBCA) method, lactone sector rule, and electronic circular dichroism (ECD) calculations. Compounds 8–11 were active against the influenza A virus subtype H1N1 with IC50 and selectivity index (SI) values of 38.3(±1.2)/25.0(±3.6)/ 39.7(±5.6)/45.9(±2.1) μg/mL and 3.0/16.1/3.1/11.4, respectively. The IC50 and SI values of positive control, ribavirin, were 23.1(±1.7) μg/mL and 32.2, respectively. The results showed that compound 9 could be a promising new hit for anti-H1N1 drugs. The absolute configurations of 2–5, 13C nuclear magnetic resonance (NMR) data and the specific rotations of 3–6 were also reported here for the first time.