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The present research focuses on the role of "official accounts" on WeChat, designed for the dissemination of textual content in the Chinese language. Currently, it is the main channel for information dissemination in that language. The objective is to investigate changes in this function between 2020 and 2023, and their impact on the mode of production and dissemination of content. To achieve this goal, a qualitative comparative methodology has been used, comparing the services in the function as it was before 2020 and its current state in 2023. Specifically, innovations are classified into three aspects: content format, interaction, and text indicators. [ABSTRACT FROM AUTHOR]

The challenge to wide application of optical tweezers in biological micromanipulation is the photodamage caused by high-intensity laser exposure to the manipulated living systems. While direct exposure to infrared lasers is less likely to kill cells, it can affect cell behavior and signaling. Pushing cells with optically trapped objects has been introduced as a less invasive alternative, but the technique includes some exposure of the biological object to parts of the optical tweezer beam. To keep the cells farther away from the laser, we introduce an indirect pushing-based technique for noninvasive manipulation of sensitive cells. We compare how cells respond to three manipulation approaches: direct manipulation, pushing, and indirect pushing. We find that indirect manipulation techniques lessen the impact of manipulation on cell behavior. Cell survival increases, as does the ability of cells to maintain shape and wiggle. Our experiments also demonstrate that indirect pushing allows cell-cell contacts to be formed in a controllable way, while retaining the ability of cells to change shape and move. [ABSTRACT FROM AUTHOR]

Graphene and two-dimensional transition metal carbides and/or nitrides (MXenes) are important materials for making flexible energy storage devices because of their electrical and mechanical properties. It remains a challenge to assemble nanoplatelets of these materials at room temperature into in-plane isotropic, free-standing sheets. Using nanoconfined water-induced basal-plane alignment and covalent and π-π interplatelet bridging, we fabricated Ti3C2Tx MXene-bridged graphene sheets at room temperature with isotropic in-plane tensile strength of 1.87 gigapascals and moduli of 98.7 gigapascals. The in-plane room temperature electrical conductivity reached 1423 siemens per centimeter, and volumetric specific capacity reached 828 coulombs per cubic centimeter. This nanoconfined water-induced alignment likely provides an important approach for making other aligned macroscopic assemblies of two-dimensional nanoplatelets. [ABSTRACT FROM AUTHOR]

A kind of topological material, the type-II Weyl semimetal, was proposed recently where the Weyl points emerge at the contact points of the electron and hole pockets, resulting in a highly tilted Weyl cone. In type-II Weyl semimetals, the Lorentz invariance is violated and a different type of Weyl fermion is generated that leads to intriguing physical properties. WTe2 is interesting because it is predicted to be a good candidate for realizing type-II Weyl semimetals. By utilizing laser-based angle-resolved photoemission spectroscopy with high energy and momentum resolutions, we have revealed a full picture of the electronic structure of WTe2. A clear surface state has been identified and its connection with the bulk electronic states in the momentum and energy space shows good agreement with band structure calculations. Our results provide electronic signatures that are consistent with type-II Weyl states in WTe2. They lay a foundation for further investigations on the topological nature of WTe2 and the exploration of unique phenomena and physical properties in type-II Weyl semimetals. [ABSTRACT FROM AUTHOR]

Chemiluminescence (CL) with the elimination of excitation light and minimal autofluorescence interference has been wieldy applied in biosensing and bioimaging. However, the traditional emission of CL probes was mainly in the range of 400 to 650 nm, leading to undesired resolution and penetration in a biological object. Therefore, it was urgent to develop CL molecules in the near-infrared window [NIR, including NIR-I (650 to 900 nm) and near-infrared-II (900 to 1,700 nm)], coupled with unique advantages of long-time imaging, sensitive response, and high resolution at depths of millimeters. However, no NIR-II CL unimolecular probe has been reported until now. Herein, we developed an H2S-activated NIR-II CL probe [chemiluminiscence donor 950, (CD-950)] by covalently connecting two Schaap's dioxetane donors with high chemical energy to a NIR-II fluorophore acceptor candidate via intramolecular CL resonance energy transfer strategy, thereby achieving high efficiency of 95%. CD-950 exhibited superior capacity including long-duration imaging (~60 min), deeper tissue penetration (~10 mm), and specific H2S response under physiological conditions. More importantly, CD-950 showed detection capability for metformin-induced hepatotoxicity with 2.5-fold higher signal-to-background ratios than that of NIR-II fluorescence mode. The unimolecular NIR-II CL probe holds great potential for the evaluation of drug-induced side effects by tracking its metabolites in vivo, further facilitating the rational design of novel NIR-II CL-based detection platforms. [ABSTRACT FROM AUTHOR]

The abasic site is one the most common DNA lesions formed in cells; it induces a severe blockage of DNA replication and is highly mutagenic. We continue to use Gp90 exo–, the sole DNA polymerase from Pseudomonas aeruginosa phage PaP1, to study DNA replication upon encountering an abasic site lesion. Gp90 exo– can incorporate dNTPs opposite the abasic site, but extension past this site is extremely slow. Among the four dNTPs, dATP is preferentially incorporated opposite the abasic site, consistent with the A-rule. The incorporation is independent of the identity of the nucleotide 5′ of the abasic site. The incorporation of dATP opposite the abasic site occurs by direct incorporation of dNTP opposite the abasic site without a −1 frameshift deletion. Extension from an A:abasic site pair by Gp90 exo– is slightly unfavorable relative to those from other abasic site pairs. Incorporation of dATP opposite the abasic site is preferential and shows a biphasic shape, indicating that this incorporation is much faster than the subsequent dissociation of the polymerase from DNA. The template sequence does not affect the dATP incorporation priority, burst amplitude, burst rate, or dATP dissociation constant. Surface plasmon resonance shows that the presence of an abasic site in the template weakens the binding affinity of Gp90 exo– to DNA in a binary or ternary complex in the presence of any one kind of dNTP. This study reveals that Gp90 exo– preferentially inserts A opposite an abasic site via the A-rule, like other DNA polymerases (e.g., Pol θ, KlenTaq, KF exo–, Pols α, δ/PCNA, and Thermococcus litoralis Pol Vent (exo–)), providing further insight into DNA replication mediated by P. aeruginosa phage PaP1 upon encountering an abasic site lesion. [ABSTRACT FROM AUTHOR]