High-order exciton complexes induced by an interlayer carrier transfer in 2D van der Waals heterostructures.

High-order correlated excitonic states, such as biexciton, charged biexciton, and polaron, hold a promising platform in contemporary quantum and nonlinear optics due to their large Bohr radii and thus strong nonlinear interactions. The recently found 2D TMDs further give such excitonic states additional valley properties, with bound state of excitons in opposite valleys in momentum spaces. Despite great efforts that have been made on emission properties of excitonic states, their absorption features, especially the ultrafast absorption dynamics, are rarely reported. Here, we reported the enhanced optical absorption of the high-order charged-excitonic states in monolayer WS2, including singlet, triplet, and semidark trions (3-particle state), and charged biexcitons (5-particle state), by utilizing the interlayer charge transfer-induced photo-doping effect in the graphene-WS2 heterostructure. Depending on recombination rates of doping electrons, absorption intensities of charged complexes exhibit ultrafast decay dynamics, with lifetimes of several picoseconds. Due to many-body interaction, both increasing pump intensity and lattice temperature can broaden these fine excitonic absorption peaks and even reverse the shape of the transient absorption spectrum.

Electrochemical Sensor for the Detection and Accurate Early Diagnosis of Ovarian Cancer.

Ovarian cancer (OC) has the highest mortality rate among malignant tumors, primarily because it is difficult to diagnose early. Exosomes, a type of extracellular vesicle rich in parental information, have garnered significant attention in the field of cancer diagnosis and treatment. They play an important regulatory role in the occurrence, development, and metastasis of OC. Consequently, exosomes have emerged as noninvasive biomarkers for early cancer detection. Therefore, identifying cancer-derived exosomes may offer a novel biomarker for the early detection of OC. In this study, we developed a metal-organic frameworks assembled "double hook"-type aptamer electrochemical sensor, which enables accurate early diagnosis of OC. Under optimal experimental conditions, electrochemical impedance spectroscopy technology demonstrated a good linear relationship within the concentration range of 31-3.1 × 106 particles per microliter, with a detection limit as low as 12 particles per microliter. The universal exosome detection platform is constructed, and this platform can not only differentiate between high-grade serous ovarian cancer (HGSOC) patients and healthy individuals but also distinguish between HGSOC patients and nonhigh-grade serous OC (non-HGSOC). Consequently, it provides a novel strategy for the early diagnosis of OC and holds great significance in clinical differential diagnosis.

Development of a CRISPR/Cas12a-mediated aptasensor for Mpox virus antigen detection.

The emergence and rapid spread of Mpox (formerly monkeypox) have caused significant societal challenges. Adequate and appropriate diagnostics procedures are an urgent necessity. Herein, we discover a pair of aptamers through the systematic evolution of ligands by exponential enrichment (SELEX) that exhibit high affinity and bind to different sites towards the A29 protein of the Mpox virus. Subsequently, we propose a facile, sensitive, convenient CRISPR/Cas12a-mediated aptasensor for detecting the A29 antigen. The procedure employs the bivalent aptamers recognition, which induces the formation of a proximity switch probe and initiates subsequent cascade strand displacement reactions, then triggers CRISPR/Cas12a DNA trans-cleavage to achieve the sensitive detection of Mpox. Our method enables selective and ultrasensitive evaluation of the A29 protein within the range of 1 ng mL-1 to 1 µg mL-1, with a limit of detection (LOD) at 0.28 ng mL-1. Moreover, spiked A29 protein recovery exceeds 96.9%, while the detection activity remains above 91.9% after six months of storage at 4 °C. This aptasensor provides a novel avenue for exploring clinical diagnosis in cases involving Mpox as facilitating development in various analyte sensors.

Charged biexciton polaritons sustaining strong nonlinearity in 2D semiconductor-based nanocavities.

Controlling the interaction between light and matter at micro- and nano-scale can provide new opportunities for modern optics and optoelectronics. An archetypical example is polariton, a half-light-half-matter quasi particle inheriting simultaneously the robust coherence of light and the strong interaction of matter, which plays an important role in many exotic phenomena. Here, we open up a new kind of cooperative coupling between plasmon and different excitonic complexes in WS2-silver nanocavities, namely plasmon-exciton-trion-charged biexciton four coupling states. Thanks to the large Bohr radius of up to 5 nm, the charged biexciton polariton exhibits strong saturation nonlinearity, ~30 times higher than the neutral exciton polariton. Transient absorption dynamics further reveal the ultrafast many-body interaction nature, with a timescale of <100 fs. The demonstration of biexciton polariton here combines high nonlinearity, simple processing and strong scalability, permitting access for future energy-efficient optical switching and information processing.

Visualizing Hot-Carrier Expansion and Cascaded Transport in WS2 by Ultrafast Transient Absorption Microscopy.

The competition between different spatiotemporal carrier relaxation determines the carrier harvesting in optoelectronic semiconductors, which can be greatly optimized by utilizing the ultrafast spatial expansion of highly energetic carriers before their energy dissipation via carrier-phonon interactions. Here, the excited-state dynamics in layered tungsten disulfide (WS2 ) are primarily imaged in the temporal, spatial, and spectral domains by transient absorption microscopy. Ultrafast hot carrier expansion is captured in the first 1.4 ps immediately after photoexcitation, with a mean diffusivity up to 980 cm2 s-1 . This carrier diffusivity then rapidly weakens, reaching a conventional linear spread of 10.5 cm2 s-1 after 2 ps after the hot carriers cool down to the band edge and form bound excitons. The novel carrier diffusion can be well characterized by a cascaded transport model including 3D thermal transport and thermo-optical conversion, in which the carrier temperature gradient and lattice thermal transport govern the initial hot carrier expansion and long-term exciton diffusion rates, respectively. The ultrafast hot carrier expansion breaks the limit of slow exciton diffusion in 2D transition metal dichalcogenides, providing potential guidance for high-performance applications and thermal management of optoelectronic technology.

Interacting plexcitons for designed ultrafast optical nonlinearity in a monolayer semiconductor.

Searching for ideal materials with strong effective optical nonlinear responses is a long-term task enabling remarkable breakthroughs in contemporary quantum and nonlinear optics. Polaritons, hybridized light-matter quasiparticles, are an appealing candidate to realize such nonlinearities. Here, we explore a class of peculiar polaritons, named plasmon-exciton polaritons (plexcitons), in a hybrid system composed of silver nanodisk arrays and monolayer tungsten-disulfide (WS2), which shows giant room-temperature nonlinearity due to their deep-subwavelength localized nature. Specifically, comprehensive ultrafast pump-probe measurements reveal that plexciton nonlinearity is dominated by the saturation and higher-order excitation-induced dephasing interactions, rather than the well-known exchange interaction in traditional microcavity polaritons. Furthermore, we demonstrate this giant nonlinearity can be exploited to manipulate the ultrafast nonlinear absorption properties of the solid-state system. Our findings suggest that plexcitons are intrinsically strongly interacting, thereby pioneering new horizons for practical implementations such as energy-efficient ultrafast all-optical switching and information processing.

4-Methyl-sulfanyl-6-(4-pyrid-yl)-1,3,5-triazin-2-amine.

In the title compound, C(9)H(9)N(5)S, the pyridyl and triazine rings make a dihedral angle of 4.8 (2)°. In the crystal, adjacent mol-ecules are bridged by an N-H⋯N hydrogen bond, forming a helical chain running along the b axis.

High STK40 Expression as an Independent Prognostic Biomarker and Correlated with Immune Infiltrates in Low-Grade Gliomas.

BACKGROUND: Expression of STK40 is observed in some cancer types, while its role in low-grade gliomas (LGG) is unclear. The present study aimed to demonstrate the relationship between STK40 and LGG based on The Cancer Genome Atlas (TCGA) database and bioinformatics analysis. METHODS: Kruskal-Wallis test, Wilcoxon sign-rank test, and logistic regression were used to evaluate the relationship between clinicopathological features and STK40 expression. Kaplan-Meier method and Cox regression analysis were used to evaluate prognostic factors. Gene set enrichment analysis (GSEA) and immuno-infiltration analysis were used to determine the significant involvement of STK40 in function. RESULTS: High STK40 expression in LGG was associated with WHO grade (P<0.001), IDH status (P<0.001), primary therapy outcome (P=0.027), 1p/19q codeletion (P<0.001) and histological type (P<0.001). High STK40 expression predicted a poorer overall survival (OS) (HR: 3.07; 95% CI: 2.09-4.51; P<0.001), progression-free survival (PFS) (HR:2.11; 95% CI: 1.59-2.81; P<0.001) and disease specific survival (DSS) (HR: 3.27; 95% CI: 2.17-4.92; P<0.001). STK40 expression (HR: 2.284; 95% CI: 1.125-4.637; P=0.022) was independently correlated with OS in LGG patients. GSEA demonstrated that pathways including cell cycle mitotic, neutrophil degranulation, signaling by Rho GTPases, signaling by interleukins, M phase, PI3K-Akt signaling pathway and naba secreted factors were differentially enriched in STK40 high expression phenotype. Immune infiltration analysis showed that STK40 expression was correlated with some types of immune infiltrating cells. CONCLUSION: STK40 expression was significantly correlated with poor survival and immune infiltration in LGG, and it may be a promising prognostic biomarker in LGG.

Conformal Self-Assembly of Nanospheres for Light-Enhanced Airtightness Monitoring and Room-Temperature Gas Sensing.

The fabrication of conformal nanostructures on microarchitectures is of great significance for diverse applications. Here a facile and universal method was developed for conformal self-assembly of nanospheres on various substrates including convex bumps and concave holes. Hydrophobic microarchitectures could be transferred into superhydrophilic ones using plasma treatment due to the formation of numerous hydroxyl groups. Because of superhydrophilicity, the nanosphere suspension spread on the microarchitectures quickly and conformal self-assembly of nanospheres can be realized. Besides, the feature size of the conformal nanospheres on the substrates could be further regulated by plasma treatment. After transferring two-dimensional tungsten disulfide sheets onto the conformal nanospheres, the periodic nanosphere array was demonstrated to be able to enhance the light harvesting of WS2. Based on this, a light-enhanced room-temperature gas sensor with a fast recovery speed (<35 s) and low detecting limit (500 ppb) was achieved. Moreover, the WS2-covered nanospheres on the microarchitectures were very sensitive to the changes in air pressure due to the formation of suspended sheets on the convex bumps and concave holes. A sensitive photoelectronic pressure sensor that was capable of detecting the airtightness of vacuum devices was developed using the WS2-decorated hierarchical architectures. This work provides a simple method for the fabrication of conformal nanospheres on arbitrary substrates, which is promising for three-dimensional microfabrication of multifunctional hierarchical microarchitectures for diverse applications, such as biomimetic compound eyes, smart wetting surfaces and photonic crystals.

Distinctive Interfacial Charge Behavior and Versatile Photoresponse Performance in Isotropic/Anisotropic WS2/ReS2 Heterojunctions.

Van der Waals (vdWs) heterostructures based on in-plane isotropic/anisotropic 2D-layered semiconducting materials have recently received wide attention because of their unique interlayer coupling properties and hold a bright future as building blocks for advanced photodetectors. However, a fundamental understanding of charge behavior inside this kind of heterostructure in the photoexcited state remains elusive. In this work, we carry out a systematic investigation into the photoinduced interfacial charge behavior in type-II WS2/ReS2 vertical heterostructures via polarization-dependent pump-probe microscopy. Benefiting from the distinctive (ultrafast and anisotropic) charge-transfer mechanisms, the photodetector based on the WS2/ReS2 heterojunction displays more superior optoelectronic properties compared to its constituents with diverse functionalities including moderate photoresponsivity, polarization sensitivity, and fast photoresponse speed. Additionally, this device can function as a self-driven photodetector without the external bias. These results of our work tangibly corroborate the intriguing interlayer interaction in in-plane isotropic/anisotropic heterostructures and are expected to shed light on designing balanced-performance multifunctional optoelectrical devices.

Extraction optimization, antioxidant activity, and tyrosinase inhibitory capacity of polyphenols from Lonicera japonica.

The objective of this research was twofold: first, to optimize the extraction process of Lonicera japonica polyphenols using a response surface methodology, and second, to study the antioxidant activity and tyrosinase inhibitory capacity of the polyphenols of different purities. High-speed shearing homogenization extraction was used to extract the polyphenols from L. japonica. The antioxidant activity and the effect of polyphenols on tyrosinase activity were studied using free radical scavenging assay and the tyrosinase method, respectively. The optimal extraction conditions with an extraction yield of 6.96% for polyphenols were determined as follows: ethanol volume fraction 57%, shearing time 3.30 min, and solid-liquid ratio 1:58. Lonicera japonica polyphenols exhibited potent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and inhibitory capacity on tyrosinase. The results suggested that L. japonica polyphenols could be explored as a natural antioxidant and tyrosinase inhibitor.

A threefold interpenetrated two-dimensional zinc(II) supramolecular architecture based on 3-nitrobenzoic acid and 4,4'-bipyridine.

With regard to crystal engineering, building block or modular assembly methodologies have shown great success in the design and construction of metal-organic coordination polymers. The critical factor for the construction of coordination polymers is the rational choice of the organic building blocks and the metal centre. The reaction of Zn(OAc)2·2H2O (OAc is acetate) with 3-nitrobenzoic acid (HNBA) and 4,4'-bipyridine (4,4'-bipy) under hydrothermal conditions produced a two-dimensional zinc(II) supramolecular architecture, catena-poly[[bis(3-nitrobenzoato-κ(2)O,O')zinc(II)]-µ-4,4'-bipyridine-κ(2)N:N'], [Zn(C7H4NO4)2(C10H8N2)]n or [Zn(NBA)2(4,4'-bipy)]n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction analysis. The Zn(II) ions are connected by the 4,4'-bipy ligands to form a one-dimensional zigzag chain and the chains are decorated with anionic NBA ligands which interact further through aromatic π-π stacking interactions, expanding the structure into a threefold interpenetrated two-dimensional supramolecular architecture. The solid-state fluorescence analysis indicates a slight blue shift compared with pure 4,4'-bipyridine and HNBA.

A one-dimensional cobalt(II) coordination polymer based on 2,4'-oxydibenzoic acid: poly[[[diaquabis[2-(4-carboxyphenoxy)benzoato-κO(1)]cobalt(II)]-µ-4,4'-bipyridine-κ(2)N:N'] dihydrate].

The reaction of CoSO4 with 2,4-oxydibenzoic acid (H2oba) and 4,4'-bipyridine (bipy) under hydrothermal condition yielded a new one-dimensional cobalt(II) coordination polymer, {[Co(C14H9O5)2(C10H8N2)(H2O)2]·2H2O}n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, magnetic properties and single-crystal X-ray diffraction. The Co(II) ions are connected by bipy ligands into infinite one-dimensional chains. The Hoba(-) ligands extend out from the two sides of the one-dimensional chain. O-H···O hydrogen bonding extends these chains into a two-dimensional supramolecular architecture.