Anomalous Phonon Behavior and Tunable Exciton Emissions: Insights into Pressure-Driven Dynamics in Silicon Phosphide.

IV-V two-dimensional materials have emerged as key contenders for polarization-sensitive and angle-resolved devices, given their inherent anisotropic physical properties. While these materials exhibit intriguing high-pressure quasi-particle behavior and phase transition, the evolution of quasi-particles and their interactions under external pressure remain elusive. Here, employing a diamond anvil cell and spectroscopic measurements coupled with first-principles calculations, we unveil rarely observed pressure-induced phonon-phonon coupling in layered SiP flakes. This coupling manifests as an anomalous phonon hardening behavior for the A1 mode within a broad wavenumber phonon softening region. Furthermore, we demonstrate the effective tuning of exciton emissions in SiP flakes under pressure, revealing a remarkable 63% enhancement in the degree of polarization (DOP) within the pressure range of 0-3.5 GPa. These findings contribute to our understanding of high-pressure phonon evolution in SiP materials and offer a strategic approach to manipulate the anisotropic performance of in-plane anisotropic 2D materials.

Emergence of Optical Anisotropy in Moiré Superlattice via Heterointerface Engineering.

The interaction between light and moiré superlattices presents a platform for exploring unique light-matter phenomena. Tailoring these optical properties holds immense potential for advancing the utilization of moiré superlattices in photonics, optoelectronics, and valleytronics. However, the control of the optical polarization state in moiré superlattices, particularly in the presence of moiré effects, remains elusive. Here, we unveil the emergence of optical anisotropy in moiré superlattices by constructing twisted WSe2/WSe2/SiP heterostructures. We report a linear polarization degree of ∼70% for moiré excitons, attributed to the spatially nonuniform charge distribution, corroborated by first-principles calculations. Furthermore, we demonstrate the modulation of this linear polarization state via the application of a magnetic field, resulting in polarization angle rotation and a magnetic-field-dependent linear polarization degree, influenced by valley coherence and moiré potential effects. Our findings demonstrate an efficient strategy for tuning the optical polarization state of moiré superlattices using heterointerface engineering.

Giant Optical Anisotropy Induced by Magnetic Order in FePS3/WSe2 Heterostructures.

Magnetic 2D materials offer a promising platform for manipulating quantum states at the nanoscale. Recent studies have underscored the significant influence of 2D magnetic materials on the optical behaviors of transition-metal dichalcogenides (TMDs), revealing phenomena such as interlayer exciton-magnon interactions, magnetization-dependent valley polarization, and an enhanced Zeeman effect. However, the controlled manipulation of anisotropic optical properties in TMDs via magnetism remains challenging. Here, the magnetic ordering in FePS3 profoundly impacts the optical characteristics of WSe2, achieving a giant linear polarization degree of 5.1 in exciton emission is demonstrated. This is supported by a detailed analysis of low-temperature photoluminescence (PL) and Raman spectra from nL-FePS3/WSe2 heterostructures. These findings indicate that a phase transition in FePS3 from paramagnetic to antiferromagnetic enhances interlayer Coulomb interactions, inducing a transition from non-polar to polar behavior in the heterostructures. Additionally, valley-polarized PL spectra under magnetic fields from -9 to 9 T reveal the influence of FePS3 on valley polarization and Zeeman splitting of excitons in monolayer WSe2. These results present a novel strategy for tailoring the optoelectronic properties of 2D magnetic van der Waals heterostructures, paving the way for advancements in nanoscale device design.

Glutathione: A Key Regulator of Extracellular Matrix and Cell Death in Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) is a degenerative disease accompanied by the loss of nucleus pulposus cells and the degradation of extracellular matrix (ECM), which tends to be associated with lower back pain. The ECM and various types of cell death in IVDD are regulated by multiple factors, such as inflammatory responses and oxidative stress. The glutathione (GSH) redox system is the most important antioxidant defense system in cells. GSH is one of the most abundant thiol antioxidants in mammalian cells, which functions directly and indirectly by scavenging peroxides through the GSH redox system. In these reactions, GSH is oxidized by electrophilic substances, such as reactive oxygen species and free radicals, to form glutathione disulfide to exert antioxidative effects. It has been reported that GSH can protect cells against the damage of oxidative stress and various pathophysiological stimulus that can lead to different types of cell death. In addition, it was reported that the level of GSH widely participates in apoptosis, autophagy, ferroptosis, and oxidative stress in many diseases including osteoarthritis and IVDD. Therefore, we summarized the effects of GSH on ECM metabolism and cells' functions during IVDD. In addition, we summarized the regulatory effects of small molecule compounds on GSH to explore potential ways to regulate the level of GSH. Better understanding the underlying role of GSH in regulating IVDD will facilitate the goal of preventing and retarding the progress of IVDD in the future.

Pressure-Induced Dynamic Tuning of Interlayer Coupling in Twisted WSe2/WSe2 Homobilayers.

Moiré superlattices induced by twisted van der Waals (vdW) heterostructures or homostructures have recently gained significant attention due to their potential to generate exotic strong-correlation electronic and phonon phenomena. However, the lack of dynamic tuning for interlayer coupling of moiré superlattices hinders a thorough understanding and development of the moiré correlation state. Here, we present a dynamic tuning method for twisted WSe2/WSe2 homobilayers using a diamond anvil cell (DAC). We demonstrate the powerful tuning of interlayer coupling and observe an enhanced response to pressure for interlayer breathing modes and the rapid descent of indirect excitons in twisted WSe2/WSe2 homobilayers. Our findings indicate that the introduction of a moiré superlattice for WSe2 bilayers gives rise to hybridized excitons, which lead to the different pressure-evolution exciton behaviors compared to natural WSe2 bilayers. Our results provide a novel understanding of moiré physics and offer an effective method to tune interlayer coupling of moiré superlattices.

Moiré Enhanced Potentials in Twisted Transition Metal Dichalcogenide Trilayers Homostructures.

The exploration of moiré superlatticesholds promising potential to uncover novel quantum phenomena emerging from the interplay of atomic structure and electronic correlation . However, the impact of the moiré potential modulation on the number of twisted layers has yet to be experimentally explored. Here, this work synthesizes a twisted WSe2 homotrilayer using a dry-transfer method and investigates the enhancement of the moiré potential with increasing number of twisted layers. The results of the study reveal the presence of multiple exciton resonances with positive or negative circularly polarized emission in the WSe2 homostructure with small twist angles, which are attributed to the excitonic ground and excited states confined to the moiré potential. The distinct g-factor observed in the magneto-optical spectroscopy is also shown to be a result of the confinement of the exciton in the moiré potential. The moiré potential depths of the twisted bilayer and trilayer homostructures are found to be 111 and 212 meV, respectively, an increase of 91% from the bilayer structure. These findings demonstrate that the depth of the moiré potential can be manipulated by adjusting the number of stacked layers, providing a promising avenue for exploration into highly correlated quantum phenomena.

Engineering anisotropy in 2D transition metal dichalcogenides via heterostructures.

Two-dimensional (2D) semiconductors featuring low-symmetry crystal structures hold an immense potential for the design of advanced optoelectronic devices, leveraging their inherent anisotropic attributes. While the synthesis techniques for transition metal dichalcogenides (TMDs) have matured, a promising avenue emerges: the induction of anisotropy within symmetric TMDs through interlayer van der Waals coupling engineering. Here, we unveil the creation of heterostructures (HSs) by stacking highly symmetric MoSe2 with low-symmetry ReS2, introducing artificial anisotropy into monolayer MoSe2. Through a meticulous analysis of angle-dependent photoluminescence (PL) spectra, we discern a remarkable anisotropic intensity ratio of approximately 1.34. Bolstering this observation, the angle-resolved Raman spectra provide unequivocal validation of the anisotropic optical properties inherent to MoSe2. This intriguing behavior can be attributed to the in-plane polarization of MoSe2, incited by the deliberate disruption of lattice symmetry within the monolayer MoSe2 structure. Collectively, our findings furnish a conceptual blueprint for engineering both isotropic and anisotropic HSs, thereby unlocking an expansive spectrum of applications in the realm of high-performance optoelectronic devices.

Strain-tunable valley polarization and localized excitons in monolayer WSe2.

Monolayer transition metal dichalcogenides (TMDs) have a crystalline structure with broken spatial inversion symmetry, making them promising candidates for valleytronic applications. However, the degree of valley polarization is usually not high due to the presence of intervalley scattering. Here, we use the nanoindentation technique to fabricate strained structures of WSe2 on Au arrays, thus demonstrating the generation and detection of strained localized excitons in monolayer WSe2. Enhanced emission of strain-localized excitons was observed as two sharp photoluminescence (PL) peaks measured using low-temperature PL spectroscopy. We attribute these emerging sharp peaks to excitons trapped in potential wells formed by local strains. Furthermore, the valley polarization of monolayer WSe2 is modulated by a magnetic field, and the valley polarization of strained localized excitons is increased, with a high value of up to approximately 79.6%. Our results show that tunable valley polarization and localized excitons can be realized in WSe2 monolayers, which may be useful for valleytronic applications.

Layer-dependent excitonic valley polarization properties in MoS2-WS2 heterostructures.

In this work, we investigate the polarization of the excitonics valley in MoS2-WS2 heterostructures using circular polarization-resolved photoluminescence. The valley polarization is the largest (≈28.45%) in the 1L-1L MoS2-WS2 heterostructure and the polarizability of AWS2 decreases as the number of WS2 layers increases. We further observed a redshift of exciton XMoS2- in MoS2-WS2 heterostructures with the increase of WS2 layers, which is attributed to the displacement of the MoS2 band edge, indicating the layer-sensitive optical properties of the MoS2-WS2 heterostructure. Our findings shed light on the understanding of exciton behavior in multilayer MoS2-WS2 heterostructures that may promote their potential applications in optoelectronic devices.

Elucidation of leak-resistance DNA hybridization chain reaction with universality and extensibility.

Hybridization chain reaction (HCR) was a significant discovery for the development of nanoscale materials and devices. One key challenge for HCR is the vulnerability to background leakage in the absence of the initiator. Here, we systematically analyze the sources of leakage and refine leak-resistant rule by using molecular thermodynamics and dynamics, biochemical and biophysical methods. Transient melting of DNA hairpin is revealed to be the underlying cause of leakage and that this can be mitigated through careful consideration of the sequence thermodynamics. The transition threshold of the energy barrier is proposed as a testing benchmark of leak-resistance DNA hairpins. The universal design of DNA hairpins is illustrated by the analysis of hsa-miR-21-5p as biomarker when used in conjunction with surface-enhanced Raman spectroscopy. We further extend the strategy for specific signal amplification of miRNA homologs. Significantly, it possibly provides a practical route to improve the accuracy of DNA self-assembly for signal amplification, and that could facilitate the development of sensors for the sensitive detection of interest molecules in biotechnology and clinical medicine.

The clinical application of individualized three-dimensional printing guiding template for assisting scaphoid fracture fixation through dorsal approach.

The purpose is to introduce a novel scaphoid screw placement surgery based on a novel three-dimensional (3D) printing guiding template through dorsal approach, and to evaluate the clinical feasibility and accuracy. The diagnose of scaphoid fracture was confirmed by Computed Tomography (CT) scanning, and subsequently the CT scanning data was input into a three-dimension imaging system(Hongsong software, China). An individualized 3D skin surface template with a guiding hole was printed. We put the template to the correct position on patient's wrist. Fluoroscopy was used to confirm the accurate position after drilling of Kirschner wire according to the prefabricated holes of template. Finally, the hollow screw was inserted through the wire. The operations were performed successfully without incision and complications. The operation time was below 20 minutes and the blood loss was below 1ml. The intraoperative fluoroscopy demonstrated good position of the screws. Postoperative imaging showed that the screws were considered to be placed perpendicularly to the fracture plane in the scaphoid. Three months after the operation, the patients acquired good recovery of the motor function of their hands. This present study suggested that the computer-assisted 3D printing guiding template is effective, reliable, and minimally invasive for the treatment of type B scaphoid fracture through dorsal approach.

General Surface-Enhanced Raman Spectroscopy Method for Actively Capturing Target Molecules in Small Gaps.

Over the past decade, many efforts have been devoted to designing and fabricating substrates for surface-enhanced Raman spectroscopy (SERS) with abundant hot spots to improve the sensitivity of detection. However, there have been many difficulties involved in causing molecules to enter hot spots actively or effectively. Here, we report a general SERS method for actively capturing target molecules in small gaps (hot spots) by constructing a nanocapillary pumping model. The ubiquity of hot spots and the inevitability of molecules entering them lights up all the hot spots and makes them effective. This general method can realize the highly sensitive detection of different types of molecules, including organic pollutants, drugs, poisons, toxins, pesticide residues, dyes, antibiotics, amino acids, antitumor drugs, explosives, and plasticizers. Additionally, in the dynamic detection process, an efficient and stable signal can be maintained for 1-2 min, which increases the practicality and operability of this method. Moreover, a dynamic detection process like this corresponds to the processes of material transformation in some organisms, so the method can be used to monitor transformation processes such as the death of a single cell caused by photothermal stimulation. Our method provides a novel pathway for generating hot spots that actively attract target molecules, and it can achieve general ultratrace detection of diverse substances and be applied to the study of cell behaviors in biological systems.

Construction of Optimal SERS Hotspots Based on Capturing the Spike Receptor-Binding Domain (RBD) of SARS-CoV-2 for Highly Sensitive and Specific Detection by a Fish Model.

It is highly challenging to construct the best SERS hotspots for the detection of proteins by surface-enhanced Raman spectroscopy (SERS). Using its own characteristics to construct hotspots can achieve the effect of sensitivity and specificity. In this study, we built a fishing mode device to detect the receptor-binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at low concentrations in different detection environments and obtained a sensitive SERS signal response. Based on the spatial resolution of proteins and their protein-specific recognition functions, SERS hotspots were constructed using aptamers and small molecules that can specifically bind to RBD and cooperate with Au nanoparticles (NPs) to detect RBD in the environment using SERS signals of beacon molecules. Therefore, two kinds of AuNPs modified with aptamers and small molecules were used in the fishing mode device, which can specifically recognize and bind RBD to form a stable hotspot to achieve high sensitivity and specificity for RBD detection. The fishing mode device can detect the presence of RBD at concentrations as low as 0.625 ng/mL and can produce a good SERS signal response within 15 min. Meanwhile, we can detect an RBD of 0.625 ng/mL in the mixed solution with various proteins, and the concentration of RBD in the complex environment of urine and blood can be as low as 1.25 ng/mL. This provides a research basis for SERS in practical applications for protein detection work.

IncRNA MVIH correlates with disease features, predicts treatment response and survival in pediatric acute myeloid leukemia.

OBJECTIVE: Long non-coding RNA microvascular invasion in hepatocellular carcinoma (lnc-MVIH) is correlated with unfavorable prognosis in several malignancies, while limitedly studied in pediatric acute myeloid leukemia (AML). This study aimed to investigate the correlation of lnc-MVIH with disease features, response to induction therapy, and survival in pediatric AML patients. METHODS: A total of 129 de novo pediatric AML patients who were retrospectively analyzed and 60 children with non-malignant hematological diseases who underwent bone marrow examination were reviewed as controls. Bone marrow mononuclear cells (BMMCs) were isolated from all participants to detect lnc-MVIH expression by reverse transcription-quantitative polymerase chain reaction. The complete remission status after 1 course of induction therapy, event-free survival, and overall survival of pediatric AML patients were recorded. RESULTS: Lnc-MVIH was upregulated in pediatric AML patients compared with controls (p < 0.001). In pediatric AML patients, lnc-MVIH was correlated with increased bone marrow blasts, less inv(16) or t(16;16) abnormity, and higher Chinese Medical Association (CMA) risk stratification (all p < 0.05), whereas its correlation with National Comprehensive Cancer Network (NCCN) risk stratification was not statistically significant (p = 0.098). As for prognosis, lnc-MVIH high expression patients presented with lower complete response rate to 1 course of induction therapy (61.5% vs. 79.7%, p = 0.024), shorter event-free survival (median 12.0 months vs. 22.0 months, p = 0.006), and overall survival (median 28.0 months vs. 42.0 months, p = 0.043) compared with lnc-MVIH low expression patients. CONCLUSION: Lnc-MVIH correlates with poor treatment response and unfavorable survival in pediatric AML.

Higher titer hepatitis B core antibody predicts a higher risk of liver metastases and worse survival in patients with colorectal cancer.

BACKGROUND: There have been controversial voices on if hepatitis B virus infection decreases the risk of colorectal liver metastases or not. This study aims to the find the association between HBV infection and postoperative survival of colorectal cancer and the risk of liver metastases in colorectal cancer patients. METHODS: Patients who underwent curative surgical resection for colorectal cancer between January 2011 and December 2012 were included. Patients were grouped according to anti-HBc. Differences in overall survival, time to progress, and hepatic metastasis-free survival between groups and significant predictors were analyzed. RESULTS: Three hundred twenty-seven colorectal cancer patients were comprised of 202 anti-HBc negative cases and 125 anti-HBc positive cases, and anti-HBc positive cases were further divided into high-titer anti-HBc group (39) and low-titer anti-HBc group (86). The high-titer anti-HBc group had significantly worse overall survival (5-Yr, 65.45% vs. 80.06%; P < .001), time to progress (5-Yr, 44.26% vs. 84.73%; P < .001), and hepatic metastasis-free survival (5-Yr, 82.44% vs. 94.58%; P = .029) than the low-titer group. Multivariate model showed anti-HBc ≥ 8.8 S/CO was correlated with poor overall survival (HR, 3.510; 95% CI, 1.718-7.17; P < .001), time to progress (HR, 5.747; 95% CI, 2.789-11.842; P < .001), and hepatic metastasis-free survival (HR, 3.754; 95% CI, 1.054-13.369; P = .041) in the anti-HBc positive cases. CONCLUSIONS: Higher titer anti-HBc predicts a potential higher risk of liver metastases and a worse survival in anti-HBc positive colorectal cancer patients.

Amphiphilic Functionalized Acupuncture Needle as SERS Sensor for In Situ Multiphase Detection.

Surface enhanced Raman spectroscopy (SERS) is a powerful spectroscopic technique with unique vibrational fingerprints, making it an ideal candidate for in situ multiphase detection. However, it is a great challenge to determine how to guide the SERS sensor to target molecules of interest in multiphase heterogeneous samples with minimal disturbance. Here, we present a portable ultrasensitive and highly repeatable SERS sensor for in situ multiphase detection. The sensor is composed of commercial Ag acupuncture needle and PVP-Au nanoparticles (Au NPs). The PVP on the Au NPs can adsorb and induce the Au NPs into a highly uniform array on the surface of the Ag needle because of its adhesiveness and steric nature. The Au NPs-Ag Needle system (Au-AgN) holds a huge SERS effect, which is enabled by the multiple plasmonic couplings from particle-film and interparticle. The PVP, as the amphiphilic polymer, promotes the target molecules to adsorb on surface of the Au-AgN whether in the oil phase or in the water phase. In this work, the Au-AgN sensor was directly inserted into the multiphase system with the laser in situ detection, and SERS detection at different spots of the Au-AgN sensor provided Raman signal of targets molecule in the different phase. In situ multiphase detection can minimize the disturbance of sampling and provide more accurate information. The facile fabrication and amphiphilic functionalization make Au-AgN sensor as generalized SERS detection platform for on-site testing of aqueous samples, organic samples, even the multiphase heterogeneous samples.

Sodium Chloride Crystal-Induced SERS Platform for Controlled Highly Sensitive Detection of Illicit Drugs.

A sodium chloride crystal-driven spontaneous 'hot spot' structure was demonstrated as a SERS-active platform, to get reproducible SERS signals, and eliminate the need for mapping large areas, in comparison with solution phase testing. During the process of solvent evaporation, the crystals produced induced silver aggregates to assemble around themselves. The micro-scale crystals can also act as a template to obtain an optical position, such that the assembled hot area is conveniently located during SERS measurements. More importantly, the chloride ions added in colloids can also replace the citrate and on the surface of the silver sol, and further decrease the background interference. High quality SERS spectra from heroin, methamphetamine (MAMP), and cocaine have been obtained on the crystal-driven hot spot structure with high sensitivity and credible reproducibility. This approach can not only bring the nanoparticles to form plasmonic hot spots in a controlled way, and thus provide high sensitivity, but also potentially be explored as an active substrate for label-free detection of other illicit drugs or additives.

Assessment and uncertainty analysis of groundwater risk.

Groundwater with relatively stable quantity and quality is commonly used by human being. However, as the over-mining of groundwater, problems such as groundwater funnel, land subsidence and salt water intrusion have emerged. In order to avoid further deterioration of hydrogeological problems in over-mining regions, it is necessary to conduct the assessment of groundwater risk. In this paper, risks of shallow and deep groundwater in the water intake area of the South-to-North Water Transfer Project in Tianjin, China, were evaluated. Firstly, two sets of four-level evaluation index system were constructed based on the different characteristics of shallow and deep groundwater. Secondly, based on the normalized factor values and the synthetic weights, the risk values of shallow and deep groundwater were calculated. Lastly, the uncertainty of groundwater risk assessment was analyzed by indicator kriging method. The results meet the decision maker's demand for risk information, and overcome previous risk assessment results expressed in the form of deterministic point estimations, which ignore the uncertainty of risk assessment.

Tunable Valley Pseudospin and Electron-Phonon Coupling in WSe2/1T-VSe2 Heterostructures.

Heterostructure engineering provides versatile platforms for exploring exotic physics and enhancing the device performance through interface coupling. Despite the rich array of physical phenomena presented by heterostructures composed of semiconductor and metal van der Waals materials, significant gaps remain in understanding their optical, thermal, and electronic properties. Here, we demonstrate that the valley pseudospin and electron-phonon coupling in monolayer WSe2 are significantly influenced by interface coupling with 1T-VSe2. The heterointerface alters the relaxation process of valley excitons, leading to a transition in magnetic-field-dependent valley polarization from a linear to a "V" shape. Furthermore, we uncover that enhanced electron-phonon coupling exacerbates variations in exciton and valley exciton behavior with temperature, involving higher phonon energies and a shift from acoustic to optical phonons. These findings highlight a promising pathway to manipulate valley excitons and investigate electron-phonon coupling through van der Waals interface interactions.

Research progress of procyanidins in repairing cartilage injury after anterior cruciate ligament tear.

Anterior cruciate ligament (ACL) tear is a common sports-related injury, and cartilage injury always emerges as a serious complication following ACL tear, significantly impacting the physical and psychological well-being of affected individuals. Over the years, efforts have been directed toward finding strategies to repair cartilage injury after ACL tear. In recent times, procyanidins, known for their anti-inflammatory and antioxidant properties, have emerged as potential key players in addressing this concern. This article focuses on summarizing the research progress of procyanidins in repairing cartilage injury after ACL tear. It covers the roles, mechanisms, and clinical significance of procyanidins in repairing cartilage injury following ACL tear and explores the future prospects of procyanidins in this domain. This review provides novel insights and hope for the repair of cartilage injury following ACL tear.