Transport and Spatial Separation of Valley Coherence via Few Layer WS2 Exciton-Polaritons.

The optical response in two-dimensional transition-metal dichalcogenides (2D TMDCs) is dominated by excitons. The lack of spatial inversion symmetry in the hexagonal lattice within each TMDC layer leads to valley-dependent excitonic emission of photoluminescence. Here, we demonstrate experimentally the spatial separation of valley coherent emission into orthogonal directions through self-resonant exciton polaritons of a free-standing three-layer (3L) WS2 waveguide. This was achieved by patterning a photonic crystal consisting of a square array of holes allowing for the far field probing of valley coherence of engendered exciton-polaritons. Furthermore, we report detailed experimental modal characterization of this coupled system in good agreement with theory. Momentum space measurements reveal a degree of valley coherence in the range 30-60%. This work provides a platform for manipulation of valley excitons in coherent light-matter states for potential implementations of valley-coherent optoelectronics.

Evodiamine ameliorates intervertebral disc degeneration through the Nrf2 and MAPK pathways.

Degradation of extracellular matrix (ECM), reactive oxygen species (ROS) production, and inflammation are critical players in the pathogenesis of intervertebral disc degeneration (IDD). Evodiamine exerts functions in inhibiting inflammation and maintaining mitochondrial antioxidant functions. However, the biological functions of evodiamine and its related mechanisms in IDD progression remain unknown. The IDD-like conditions in vivo were stimulated via needle puncture. Hematoxylin and eosin staining, Safranin O/Fast Green staining and Alcian staining were performed to determine the degenerative status. The primary nucleus pulposus cells (NPCs) were isolated from Sprague-Dawley rats and then treated with tert-butyl peroxide (TBHP) to induce cellular senescence and oxidative stress. The cell viability was assessed by cell counting kit-8 assays. The mitochondria-derived ROS in NPCs was evaluated by MitoSOX staining. The mitochondrial membrane potential in NPCs was identified by JC-1 staining and flow cytometry. The expression of collagen II in NPCs was measured by immunofluorescence staining. The levels of mRNAs and proteins were measured by RT-qPCR and western blotting. The Nrf2 expression in rat nucleus pulposus tissues was measured by immunohistochemistry staining. Evodiamine alleviated TBHP-induced mitochondrial dysfunctions in NPCs. The enhancing effect of TBHP on the ECM degradation was reversed by evodiamine. The TBHP-stimulated inflammatory response was ameliorated by evodiamine. Evodiamine alleviated the IDD process in the puncture-induced rat model. Evodiamine promoted the activation of Nrf2 pathway and inactivated the MAPK pathway in NPCs. In conclusion, evodiamine ameliorates the progression of IDD by inhibiting mitochondrial dysfunctions, ECM degradation and inflammation via the Nrf2/HO-1 and MAPK pathways.

Directing valley-polarized emission of 3†L WS2 by photonic crystal with directional circular dichroism.

The valley degree of freedom that results from broken inversion symmetry in two-dimensional (2D) transition-metal dichalcogenides (TMDCs) has sparked a lot of interest due to its huge potential in information processing. In this experimental work, to optically address the valley-polarized emission from three-layer (3 L) thick WS2 at room temperature, we employ a SiN photonic crystal slab that has two sets of holes in a square lattice that supports directional circular dichroism engendered by delocalized guided mode resonances. By perturbatively breaking the inversion symmetry of the photonic crystal slab, we can simultaneously manipulate s and p components of the radiating field so that these resonances correspond to circularly polarized emission. The emission of excitons from distinct valleys is coupled into different radiative channels and hence separated in the farfield. This directional exciton emission from selective valleys provides a potential route for valley-polarized light emitters, which lays the groundwork for future valleytronic devices.

Effective health management strategies for patients undergoing valve replacement: a bibliometric analysis of the current research status and future directions.

Background: Valvular heart disease is a major health concern worldwide. The effective management of patients undergoing valve replacement determines their prognosis. Bibliometric analysis of studies on managing patients with artificial heart valves has not been previously performed. Methods: This study analyzed 2,771 publications related to patient management after valve replacement published in the Web of Science Core Collection database between January 1, 2013, and December 31, 2022. Bibliometric analysis was performed using CiteSpace and VOSviewer considering countries, institutions, authors, journals, references, and keywords. Results: The countries with the most significant contributions in this field were the United States of America (USA), Germany, and Italy. Leon MB from Columbia University, USA was the most influential author. Transcatheter aortic valve replacement was a current research hotspot, while anticoagulation management was a key area of interest. Combining anticoagulation therapy with internet-linked tools and portable health devices may offer new research avenues. Frailty assessment and intervention were potential future research areas. Conclusions: This bibliometric analysis provides clinicians and researchers with useful insights for developing novel ideas and directions to manage the health of patients undergoing valve replacement.

Recycling of waste aluminum scraps to fabricate sulfidated zero-valent iron-aluminum particles for enhanced chromate removal.

Massive waste aluminum scraps produced from the spent aluminum products have high electron capacity and can be recycled as an attractive alternative to materials based on zero-valent iron (Fe0) for the removal of oxidative contaminants from wastewater. This study thus proposed an approach to fabricate micron-sized sulfidated zero-valent iron-aluminum particles (S-Al0@Fe0) with high reactivity, electron selectivity and capacity using recycled waste aluminum scraps. S-Al0@Fe0 with a three-layer structure contained zero-valent aluminum (Al0) core, Fe0 middle layer and iron sulfide (FeS) shell. The rates of chromate (Cr(VI)) removal by S-Al0@Fe0 at pH 5.0‒9.0 were 1.6‒5.9 times greater than that by sulfidated zero-valent iron (S-Fe0). The Cr(VI) removal capacity of S-Al0@Fe0 was 8.2-, 11.3- and 46.9-fold greater than those of S-Fe0, zero-valent iron-aluminum (Al0-Fe0) and Fe0, respectively. The chemical cost of S-Al0@Fe0 for the equivalent Cr(VI) removal was 78.5% lower than that of S-Fe0. Negligible release of soluble aluminum during the Cr(VI) removal was observed. The significant enhancement in the reactivity and capacity of S-Al0@Fe0 was partially ascribed to the higher reactivity and electron density of the Al0 core than Fe0. More importantly, S-Al0@Fe0 served as an electric cell to harness the persistent and selective electron transfer from the Al0-Fe0 core to Cr(VI) at the surface via coupling Fe0-Fe2+-Fe3+ redox cycles, resulting in a higher electron utilization efficiency. Therefore, S-Al0@Fe0 fabricated using recycled waste aluminum scraps can be a cost-effective and environmentally-friendly alternative to S-Fe0 for the enhanced removal of oxidative contaminants in industrial wastewater.

Tuning of excitons in phosphorene atomic chains.

An universal scaling between the exciton binding energy and quasiparticle (QP) band gap was first discovered in two-dimensional (2D) semiconductors such as graphene derivatives, various transition materials dichalcogenides, and black phosphorus (Choiet al2015Phys. Rev. Lett.115066403; Jianget al2017Phys. Rev. Lett.118266401), and later extended to quasi one-dimensional (1D) systems such as carbon nanotubes and graphene nanoribbons. In this work we study the excitonic states in phosphorene atomic chains by using the exact diagonalization method and show that the linear scaling between the exciton binding energy (Ex) and QP shift (Δqs) can be easily tuned by the dielectric environment. In the presence of weak screening,Exis seen to increase withΔqsand exhibits a similar scaling as those 2D materials. As the screening becomes stronger, however, the dependence is found to be reversed, i.e.Exnow decreases whenΔqsincreases. More interestingly, we also reveal thatExmay even become nearly constant, independent on the system dimension andΔqswhen the screening reaches a certain strength. These abnormal scaling relations are attributed to the complex nature of excitons in the strongly correlated 1D system.

Excitonic ground states in phosphorene nanoflakes.

By using a configuration-interaction approach beyond the framework of independent multiexcitons, we predict that an excitonic ground state may exist in phosphorene nanoflakes when an in-plain electric field is applied. The ground state of the system is shown to undergo a transition from purely electronic to almost fully biexcitonic with the increasing strength of the electric field. As the field exceeds 0.25 V nm-1, a biexcitonic ground state is revealed to be energetically more favorable by a few hundred meV than the system without excitons. A similar transformation of the ground state is also found as the screening effect varies from strong to weak. The enhanced electron-hole correlation, mostly caused by the applied electric field as well as the lack of strong screening in low-dimensional nanostructures, is believed to account for such an extraordinary transition. Furthermore, the system with a biexcitonic ground state is found to exhibit an absorption spectrum where many transitions are polarized along the zigzag direction, which breaks the optical anisotropy well-known for bulk phosphorene.

Myricetin alleviates H2O2-induced senescence and apoptosis in rat nucleus pulposus-derived mesenchymal stem cells.

INTRODUCTION: Transplantation of mesenchymal stem cells (MSCs) has been reported to be a novel promising target for the regeneration of degenerated intervertebral discs (IVDs). However, the culture and survival limitations of MSCs remain challenging for MSC-based biological therapy. Myricetin, a common natural flavonoid, has been suggested to possess antiaging and antioxidant abilities. Therefore, we investigated the biological function of myricetin, and its related mechanisms involving cell senescence in intervertebral disc degeneration (IDD). MATERIAL AND METHODS: The nucleus pulposus-derived mesenchymal stem cells (NPMSCs) were isolated from 4-month-old Sprague-Dawley (SD) rats and identified by examining surface markers and multipotent differentiation. Rat NPMSCs were cultured in an MSC culture medium or culture medium with different concentrations of H2O2. Myricetin or the combination of myricetin and EX527 were added to the culture medium to investigate the effects of myricetin. Cell viability was evaluated by cell counting kit-8 assays (CCK-8). The apoptosis rate was determined using Annexin V/PI dual staining. The mitochondrial membrane potential (MMP) was analyzed by a fluorescence microscope after JC-1 staining. The cell senescence was determined by SA-ß-Gal staining. MitoSOX green was used to selectively estimate mitochondrial reactive oxygen species (ROS) Apoptosis-associated proteins (Bax, Bcl2, and cleaved caspase-3), senescence markers (p16, p21, and p53), and SIRT1/PGC-1α signaling pathway-related proteins (SIRT1 and PGC-1α) were evaluated by western blotting. RESULTS: The cells isolated from nucleus pulposus (NP) tissues met the criteria for MSCs. Myricetin showed no cytotoxicity up to a concentration of 100 µM in rat NPMSCs cultured for 24 h. Myricetin pretreatment exhibited protective effects against H2O2-induced apoptosis. Myricetin could also alleviate H2O2-induced mitochondrial dysfunctions of increased mitochondrial ROS production and reduced MMP. Moreover, myricetin pretreatment delayed rat NPMSC senescence, as evidenced by decreased exppression of senescence indicators. Pretreatment of NPMSCs with 10 µM EX527, a selective inhibitor of SIRT1, prior to exposure to 100 µM H2O2, reversed the inhibitory effects of myricetin on cell apoptosis. CONCLUSIONS: Myricetin could affect the SIRT1/PGC-1α pathway to protect mitochondrial functions and alleviate cell senescence in H2O2-treated NPMSCs.

Relationship Between Family Caregiver Burden and Medication Adherence in Patients with Mechanical Valve Replacement: A Structural Equation Model.

Background: Oral anticoagulant is a necessary long-term treatment after mechanical valve replacement (MVR), and medication adherence has a great impact on patients with MVR. Although family caregiver burden is negatively correlated with medication adherence, little is known about the underlying mechanism. Purpose: To test whether family caregiver burden influences medication adherence through post-traumatic growth or medication literacy in patients with MVR. Patients and Methods: A total of 206 patients after MVR were included in this cross-sectional study from July 2021 to December 2021. Data regarding medication adherence, family caregiver burden, post-traumatic growth, and medication literacy were collected by questionnaires. Data were analyzed through SPSS, and pathway analysis was conducted by using AMOS, based on the bootstrapping method. Results: Post-traumatic growth was positively associated with medication adherence (r = 0.284, P < 0.05). Post-traumatic growth independently mediated the association of family caregiver burden on medication adherence [ß = 0.32, 95% confidence intervals: (-0.016, -0.008)]. The mediated effect value for post-traumatic growth was 0.07, accounting for 24.14% of the total effect. The model's fit indices were adequate. Conclusion: The mediating effect of post-traumatic growth between family caregiver burden and medication adherence existed in patients with MVR. Interventions considering post-traumatic growth may be useful to increase medication adherence and improve patient rehabilitation.

MoS2-enabled dual-mode optoelectronic biosensor using a water soluble variant of µ-opioid receptor for opioid peptide detection.

Owing to their unique electrical and optical properties, two-dimensional transition metal dichalcogenides have been extensively studied for their potential applications in biosensing. However, simultaneous utilization of both optical and electrical properties has been overlooked, yet it can offer enhanced accuracy and detection versitility. Here, we demonstrate a dual-mode optoelectronic biosensor based on monolayer molybdenum disulfide (MoS2) capable of producing simultaneous electrical and optical readouts of biomolecular signals. On a single platform, the biosensor exhibits a tunable photonic Fano-type optical resonance while also functioning as a field-effect transistor (FET) based on a optically transparent gate electrode. Furthermore, chemical vapor deposition grown MoS2 provides a clean surface for direct immobilization of a water-soluble variant of the µ-opioid receptor (wsMOR), via a nickel ion-mediated linker chemistry. We utilize a synthetic opioid peptide to show the operation of the electronic and optical sensing modes. The responses of both modes exhibit a similar trend with dynamic ranges of four orders of magnitude and detection limits of <1 nM. Our work explores the potential of a versatile multimodal sensing platform enabled by monolayer MoS2, since the integration of electrical and optical sensors on the same chip can offer flexibility in read-out and improve the accuracy in detection of low concentration targets.

Dynamic Photochemical and Optoelectronic Control of Photonic Fano Resonances via Monolayer MoS2 Trions.

Active tunability of photonic resonances is of great interest for various applications such as optical switching and modulation based on optoelectronic materials. Manipulation of charged excitons in atomically thin transition metal dichalcogenides (TMDCs) like monolayer MoS2 offers an unexplored route for diverse functionalities in optoelectronic nanodevices. Here, we experimentally demonstrate the dynamic photochemical and optoelectronic control of the photonic crystal Fano resonances by optical and electrical tuning of monolayer MoS2 refractive index via trions without any chemical treatment. The strong spatial and spectral overlap between the photonic Fano mode and the active MoS2 monolayer enables efficient modulation of the Fano resonance. Our approach offers new directions for potential applications in the development of optical modulators based on emerging 2D direct band gap semiconductors.