Engineering ultrasmall gold nanoclusters: tailored optical modulation for phototherapeutic and multimodal biomedical applications.

Ultrasmall gold nanoclusters (Au NCs) with core sizes below 2 nm exhibit distinctive physicochemical properties and hold remarkable promise in a variety of biomedical applications. Through precise synthesis and surface engineering, Au NCs can be endowed with high quantum yields, excellent stability, and favorable biocompatibility. Recent studies have demonstrated the versatility of Au NCs in imaging modalities-ranging from fluorescence and Raman to photoacoustics-as well as in light-driven therapeutics such as photodynamic therapy (PDT) and photothermal therapy (PTT).

Spin excitations in nanographene-based antiferromagnetic spin-1/2 Heisenberg chains.

Antiferromagnetic Heisenberg chains exhibit two distinct types of excitation spectrum: gapped for integer-spin chains and gapless for half-integer-spin chains. However, in finite-length half-integer-spin chains, quantization induces a gap, requiring precise control over sufficiently long chains to study its evolution. Here we create length-controlled spin-1/2 Heisenberg chains by covalently linking Olympicenes-Olympic-ring-shaped magnetic nanographenes.

Characterization of a 4'-O-rhamnosyltransferase and de novo biosynthesis of bioactive steroidal triglycosides from Paris polyphylla.

Steroidal saponins in Paris polyphylla featuring complicated sugar chains exhibit notable biological activities, but their sugar-chain biosynthesis is still not fully understood. Here, we identified a 4'-O-rhamnosyltransferase (UGT73DY2) from P. polyphylla, which catalyzes the 4'-O-rhamnosylation of polyphyllins V and VI, producing dioscin and pennogenin 3-O-β-chacotrioside, respectively.

A rolling circle amplification-based DNAzyme walker against intracellular degradation for imaging tumor cells' microRNA.

We present a novel DNA molecular machine (RCA-D-Walker) that integrates a DNAzyme-based molecular beacon with RCA-based vectors for miRNA imaging in tumor cells. It can accurately target tumor cells through the sgc8 aptamer. The target miRNA can restore the DNAzyme's ability to cleave the substrate, which in turn produces an amplified fluorescent signal.

Tunable topological phases in nanographene-based spin-1/2 alternating-exchange Heisenberg chains.

Unlocking the potential of topological order in many-body spin systems has been a key goal in quantum materials research. Despite extensive efforts, the quest for a versatile platform enabling site-selective spin manipulation, essential for tuning and probing diverse topological phases, has persisted. Here we utilize on-surface synthesis to construct spin-1/2 alternating-exchange Heisenberg chains by covalently linking Clar's goblets-nanographenes each hosting two antiferromagnetically coupled spins.

Characterization of a glycosyltransferase from Paris polyphylla for application in biosynthesis of rare ophiopogonins and ginsenosides.

Saponins are bioactive components of many medicinal plants, possessing complicated chemical structures and extensive pharmacological activities, but the production of high-value saponins remains challenging. In this study, a 6'-O-glucosyltransferase PpUGT7 (PpUGT91AH7) was functionally characterized from Paris polyphylla Smith var. yunnanensis (Franch.

Antioxidant and anti-Alzheimer's disease activities of 1,8-cineole and its cyclodextrin inclusion complex.

1,8-Cineole is a bicyclic monoterpene widely distributed in the essential oils of various medicinal plants, and it exhibits significant anti-inflammatory and antioxidant activities. We aimed to investigate the therapeutic effect of 1,8-cineole on anti-Alzheimer's disease by using transgenic Caenorhabditis elegans models. Our studies demonstrated that 1,8-cineole significantly relieved Aβ-induced paralysis and exhibited remarkable antioxidant and anti-Aβ aggregation activities in transgenic nematodes CL4176, CL2006 and CL2355.

Relationships among anxiety, depression, and health-related quality of life in adult epilepsy: A network analysis.

Objective: Comorbid depression and anxiety in patients with epilepsy (PWE) are common and frequently under-treated, thus, causing poor health-related quality of life (HRQoL). However, little is known regarding the interconnections between anxious/depressive symptoms and the dimensions of HRQoL. Therefore, we conducted a network analysis to explore these relationships in detail among Chinese adult PWE.

Tailoring Magnetism of Graphene Nanoflakes via Tip-Controlled Dehydrogenation.

Atomically precise graphene nanoflakes called nanographenes have emerged as a promising platform to realize carbon magnetism. Their ground state spin configuration can be anticipated by Ovchinnikov-Lieb rules based on the mismatch of π electrons from two sublattices. While rational geometrical design achieves specific spin configurations, further direct control over the π electrons offers a desirable extension for efficient spin manipulations and potential quantum device operations.

Dramatic Acceleration of the Hopf Cyclization on Gold(111): From Enediynes to Peri-Fused Diindenochrysene Graphene Nanoribbons.

Hopf et al. reported the high-temperature 6π-electrocyclization of -hexa-1,3-diene-5-yne to benzene in 1969. Subsequent studies using this cyclization have been limited by its very high reaction barrier.

Pressure-modulated lattice structural evolution in TiS.

Titanium disulfide (TiS) has drawn considerable attention in materials, physics, and chemistry thanks to its potential applications in batteries, supercapatteries and thermoelectric devices. However, the simplified and controlled synthesis of high-quality TiS remains a great challenge. In this study, a straightforward widely accessible approach to the one-step chemical vapor transport (CVT) process is presented.

Nutrition improvement program for rural compulsory education students and individual health.

We use the county-by-county rollout of the program and employ the difference-in-difference (DID) methodology to identify the effects of the implementation of the nutrition improvement program for rural compulsory education students on adolescent health. The results show that the nutrition improvement program reduces the frequency and probability of illness and improves the students' health status. The heterogeneity analysis indicates that the children in western regions and children left behind have a greater marginal improvement.

Coexistence of Robust Edge States and Superconductivity in Few-Layer Stanene.

High-quality stanene films have been actively pursued for realizing not only quantum spin Hall edge states without backscattering, but also intrinsic superconductivity, two central ingredients that may further endow the systems to host topological superconductivity. Yet to date, convincing evidence of topological edge states in stanene remains to be seen, let alone the coexistence of these two ingredients, owing to the bottleneck of growing high-quality stanene films. Here we fabricate one- to five-layer stanene films on the Bi(111) substrate and observe the robust edge states using scanning tunneling microscopy/spectroscopy.

Automatically binding relevant and irrelevant features in visual working memory.

It is generally assumed that, to save storage space, features are stored as integrated objects in visual working memory (VWM). Although such an object-based account does not always hold because features can be processed in parallel, a previous study has shown that different features can be automatically bound with their locations (task-irrelevant feature) into an integrated unit, resulting in improved memory performance. The present study was designed to further explore this phenomenon by investigating whether other features, which are not spatial in origin, can act as the binding cue to form such automatic binding.

Strain Tunable Semimetal-Topological-Insulator Transition in Monolayer 1T^{'}-WTe_{2}.

A quantum spin hall insulator is manifested by its conducting edge channels that originate from the nontrivial topology of the insulating bulk states. Monolayer 1T^{'}-WTe_{2} exhibits this quantized edge conductance in transport measurements, but because of its semimetallic nature, the coherence length is restricted to around 100 nm. To overcome this restriction, we propose a strain engineering technique to tune the electronic structure, where either a compressive strain along the a axis or a tensile strain along the b axis can drive 1T^{'}-WTe_{2} into an full gap insulating phase.

Coupling of superconductivity and Coulomb blockade in Sn nanoparticles.

Low dimensional superconductors have many unusual properties. When 0-dimensional superconductors reach the nanometer scale, the superconducting energy gap can be enhanced due to the shell effect. At the same time, the single electron Coulomb blockade effect can also be observed on metal nanoparticles if they are weakly coupled to the environment.

A QM/MM study of the catalytic mechanism of SAM methyltransferase RlmN from Escherichia coli.

RlmN is a radical S-adenosylmethionine (SAM) enzyme that catalyzes the C2 methylation of adenosine 2503 (A2503) in 23S rRNA and adenosine 37 (A37) in several Escherichia coli transfer RNAs (tRNA). The catalytic reaction of RlmN is distinctly different from that of typical SAM-dependent methyltransferases that employs an S 2 mechanism, but follows a ping-pong mechanism which involves the intermediate methylation of a conserved cysteine residue. Recently, the x-ray structure of a key intermediate in the RlmN reaction has been reported, allowing us to perform combined quantum mechanics and molecular mechanics (QM/MM) calculations to delineate the reaction details of RlmN at atomic level.

Theoretical insights into the protonation states of active site cysteine and citrullination mechanism of Porphyromonas gingivalis peptidylarginine deiminase.

Porphyromonas gingivalis peptidylarginine deiminase (PPAD) catalyzes the citrullination of peptidylarginine, which plays a critical role in the rheumatoid arthritis (RA) and gene regulation. For a better understanding of citrullination mechanism of PPAD, it is required to establish the protonation states of active site cysteine, which is still a controversial issue for the members of guanidino-group-modifying enzyme superfamily. In this work, we first explored the transformation between the two states: State N (both C351 and H236 are neutral) and State I (both residues exist as a thiolate-imidazolium ion pair), and then investigated the citrullination reaction of peptidylarginine, using a combined QM/MM approach.