Search

Dye sensitization achieving photoelectrochemical (PEC) signal amplification for ultrasensitive bioanalysis has undergone a major breakthrough. In this proposal, an innovative PEC sensing platform is developed by combining Z-scheme WO3@SnS2 photoactive materials and a G-wire superstructure as well as a dye sensitization enhancement strategy. The newly synthesized WO3@SnS2 heterojunction with outstanding PEC performance is employed as a photoelectrode matrix. Due to the formation of the Z-scheme heterojunction between WO3 and SnS2, the migration dynamics of the photogenerated carrier is evidently augmented. To improve sensitivity, the target excision-driven dual-cycle signal amplification strategy is introduced to output exponential c-myc fragments. Crystal violet is then conjugated into the G-quadruplex to amplify the PEC signal, where crystal violet generates excited electrons by capturing visible light and rapidly injects electrons into the conduction band of SnS2, suppressing the recombination of the photo-induced carrier. Moreover, the G-wire superstructure acts as a universal amplification pathway, ensuring adequate crystal violet loads. Specifically, the biosensor for uracil-DNA glycosylase quantification displays a wide detection range (0.0005-1.0 U/mL) and a lower detection limit (0.00025 U/mL). Furthermore, the Z-scheme electron migration mechanism and the crystal violet sensitization effect are discussed in detail. The construction of the PEC sensor provides a new consideration for signal amplification and material design.

The present paper was aimed to study the role of spleen tyrosine kinase (Syk) in angiogenesis in hepatopulmonary syndrome (HPS) and the underlying mechanism. Sprague Dawley (SD) rats were randomly divided into three groups: sham operation group (sham group), common bile duct ligation (CBDL) 5-week group (5W group) and R788 intervention group (R788 group). HPS model was established by CBDL. Rats in R788 group were intraperitoneally injected with R788 (20 mg/kg) once daily to week 5 after CBDL operation. The protein expression levels and distribution of Syk, p-Erk1/2, and p-Akt in lung tissue were detected by Western blot and immunohistochemistry. Immunofluorescence staining was used to observe the location of Syk expression and the number of angiogenesis in lung tissue. The results showed that, compared with sham group, 5W group exhibited up-regulated protein expression level of Syk, increased phosphorylation levels of Erk1/2 and Akt, and increased number of pulmonary microvessels. Compared with 5W group, R788 group exhibited down-regulated protein expression level of Syk, decreased phosphorylation levels of Erk1/2 and Akt, and decreased number of pulmonary microvessels. These results suggest that Syk may promote pulmonary angiogenesis in HPS model rats by activating downstream Erk1/2 and Akt signaling pathways, which provides a theoretical basis and potential drug therapeutic targets for the clinical treatment of HPS.

In2O3@Cu2MoS4 nanocomposite with superior photoelectrochemical (PEC) performance is used for the first time as a photoactivity material, and a signal-off PEC biosensing platform for miRNA detection has been successfully constructed. Firstly, the Cu2MoS4 nanosheets are synthesized by a hydrothermal method, and then, the homogeneous In2O3 nanoparticles (In2O3 NPs) are synthesized by calcination in the air. The In2O3@Cu2MoS4 nanocomposite is constructed with the Cu2MoS4 nanosheets as matrix and In2O3 NPs as sensitizer through a layer-by-layer assembly strategy. The nanocomposite with a tight interface and the matched band structure restrains the electron-hole pair recombination. Under visible light (400–700 nm), the nanocomposite exhibits a strong initial signal. With the catalyzed hairpin assembly, dozens of PbS quantum dots (QDs) are introduced on the surface of an electrode, significantly reducing the photocurrent of n-type In2O3@Cu2MoS4. Since PbS QDs can compete with the nanocomposite for light energy and electron donors, the signal decreased. Under optimal conditions, the biosensor manifests a broad linear range (1 fM–1 nM) and a low detection limit of about 0.57 fM, at a working potential of 0 V (vs. Ag/AgCl). The recovery of spiked human serum is between 94.0 and 102%, and the relative standard deviation (RSD) is between 1.3 and 2.7%. Therefore, the as-fabricated biosensor exhibits a potential for the determination of miRNA-21 in practical applications. Graphical abstract

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2; previously provisionally named 2019 novel coronavirus or 2019‐nCoV) disease (COVID‐19) in China at the end of 2019 has caused a global pandemic and remains as a major public health issue This article is protected by copyright. All rights reserved.

Cell-like spiking neural P systems (cSN P systems) are a class of membrane computing models, which have both the hierarchical structure of living cells and the way of communicating and processing information by means of neuron spikes. The universality of cSN P systems as number generating devices has been investigated, and these systems with request or evolution rules have been proved to be Turing universal. In this work, anti-spike is introduced into cSN P systems, we investigate the computational power of cSN P systems with anti-spikes by using membrane division and dissolution rules avoiding the use of producing more spikes and replicating spikes instructions. On the one hand, by adding anti-spikes to cSN P systems, we reduce the unnecessary spikes consumption of systems when simulating the subtraction instructions. On the other hand, by introducing membrane division and dissolution rules, the number of spikes used in neurons of cSN P systems with anti-spikes is limited without loss of computational power.

To discover the differences and modes of saccharifying ability among Rhizopus arrhizus strains isolated from various habitats, we grew strains in glutinous rice media to monitor the production of glucose from starch using spectrophotometry at regular time intervals. The saccharifying capacity of R. arrhizus var. delemar was found to be weaker than that of var. arrhizus and var. tonkinensis. These data provide additional phenotypic support for recognization of this genetically distinct lineage (var. delemar) as a separate species. Clinical isolates were generally low in saccharifying abilities, while all strains from southwest China had an excellent diastatic power.

Proliferative vitreoretinopathy (PVR) is the main cause of retinal detachment surgery failure. The epithelial-mesenchymal transition (EMT) induced by transforming growth factor (TGF-β2) plays an important role in the development of PVR. Artesunate has been widely studied as a treatment for ophthalmic diseases because of its antioxidant, anti-inflammatory, antiapoptotic and antiproliferative properties. The purpose of this study was to investigate the effects of artesunate on the TGF-β2-induced EMT in ARPE-19 cells and PVR development. We found that artesunate inhibited the proliferation and contraction of ARPE-19 cells after the EMT and the autocrine effects of TGF-β2 on ARPE-19 cells. Additionally, the levels of Smad3 and p-Smad3 were increased in clinical samples, and artesunate decreased the levels of Smad3 and p-Smad3 in ARPE-19 cells treated with TGF-β2. Artesunate also inhibited the occurrence and development of PVR in vivo. In summary, artesunate inhibits the occurrence and development of PVR by inhibiting the EMT in ARPE-19 cells.