Terahertz parametric amplification as a reporter of exciton condensate dynamics.

Condensates are a hallmark of emergence in quantum materials such as superconductors and charge density waves. Excitonic insulators are an intriguing addition to this library, exhibiting spontaneous condensation of electron-hole pairs. However, condensate observables can be obscured through parasitic coupling to the lattice. Here we employ nonlinear terahertz spectroscopy to disentangle such obscurants through measurement of the quantum dynamics. We target Ta2NiSe5, a putative room-temperature excitonic insulator in which electron-lattice coupling dominates the structural transition (Tc = 326 K), hindering identification of excitonic correlations. A pronounced increase in the terahertz reflectivity manifests following photoexcitation and exhibits a Bose-Einstein condensation-like temperature dependence well below the Tc, suggesting an approach to monitor the exciton condensate dynamics. Nonetheless, dynamic condensate-phonon coupling remains as evidenced by peaks in the enhanced reflectivity spectrum at select infrared-active phonon frequencies, indicating that parametric reflectivity enhancement arises from phonon squeezing. Our results highlight that coherent dynamics can drive parametric stimulated emission.

DNA methylation patterns in patients with asthenospermia and oligoasthenospermia.

BACKGROUND: Spermatogenesis is a highly regulated and complex process in which DNA methylation plays a crucial role. This study aimed to explore the differential methylation profiles in sperm DNA between patients with asthenospermia (AS) and healthy controls (HCs), those with oligoasthenospermia (OAS) and HCs, and patients with AS and those with OAS. RESULTS: Semen samples and clinical data were collected from five patients with AS, five patients with OAS, and six age-matched HCs. Reduced representation bisulfite sequencing (RRBS) was performed to identify differentially methylated regions (DMRs) in sperm cells among the different types of patients and HCs. A total of 6520, 28,019, and 16,432 DMRs were detected between AS and HC, OAS and HC, and AS and OAS groups, respectively. These DMRs were predominantly located within gene bodies and mapped to 2868, 9296, and 9090 genes in the respective groups. Of note, 12, 9, and 8 DMRs in each group were closely associated with spermatogenesis and male infertility. Furthermore, BDNF, SMARCB1, PIK3CA, and DDX27; RBMX and SPATA17; ASZ1, CDH1, and CHDH were identified as strong differentially methylated candidate genes in each group, respectively. Meanwhile, the GO analysis of DMR-associated genes in the AS vs. HC groups revealed that protein binding, cytoplasm, and transcription (DNA-templated) were the most enriched terms in the biological process (BP), cellular component (CC), and molecular function (MF), respectively. Likewise, in both the OAS vs. HC and AS vs. OAS groups, GO analysis revealed protein binding, nucleus, and transcription (DNA-templated) as the most enriched terms in BP, CC, and MF, respectively. Finally, the KEGG analysis of DMR-annotated genes and these genes at promoters suggested that metabolic pathways were the most significantly associated across all three groups. CONCLUSIONS: The current study results revealed distinctive sperm DNA methylation patterns in the AS vs. HC and OAS vs. HC groups, particularly between patients with AS and those with OAS. The identification of key genes associated with spermatogenesis and male infertility in addition to the differentially enriched metabolic pathways may contribute to uncovering the potential pathogenesis in different types of abnormal sperm parameters.

Integration of multiomics analyses reveals unique insights into CD24-mediated immunosuppressive tumor microenvironment of breast cancer.

BACKGROUND: Tumor immunotherapy brings new light and vitality to breast cancer patients, but low response rate and limitations of therapeutic targets become major obstacles to its clinical application. Recent studies have shown that CD24 is involved in an important process of tumor immune regulation in breast cancer and is a promising target for immunotherapy. METHODS: In this study, singleR was used to annotate each cell subpopulation after t-distributed stochastic neighbor embedding (t-SNE) methods. Pseudo-time trace analysis and cell communication were analyzed by Monocle2 package and CellChat, respectively. A prognostic model based on CD24-related genes was constructed using several machine learning methods. Multiple quantitative immunofluorescence (MQIF) was used to evaluate the spatial relationship between CD24+PANCK+cells and exhausted CD8+T cells. RESULTS: Based on the scRNA-seq analysis, 1488 CD24-related differential genes were identified, and a risk model consisting of 15 prognostic characteristic genes was constructed by combining the bulk RNA-seq data. Patients were divided into high- and low-risk groups based on the median risk score. Immune landscape analysis showed that the low-risk group showed higher infiltration of immune-promoting cells and stronger immune reactivity. The results of cell communication demonstrated a strong interaction between CD24+epithelial cells and CD8+T cells. Subsequent MQIF demonstrated a strong interaction between CD24+PANCK+ and exhausted CD8+T cells with FOXP3+ in breast cancer. Additionally, CD24+PANCK+ and CD8+FOXP3+T cells were positively associated with lower survival rates. CONCLUSION: This study highlights the importance of CD24+breast cancer cells in clinical prognosis and immunosuppressive microenvironment, which may provide a new direction for improving patient outcomes.

Coherent generation and control of tunable narrowband THz radiation from a laser-induced air-plasma filament.

We report on the proof-of-principle experiment of generating carrier-envelope phase (CEP)-controllable and frequency-tunable narrowband terahertz (THz) radiation from an air-plasma filament prescribed by the beat of a temporally stretched two-color laser pulse sequence. The pulse sequence was prepared by propagating the fundamental ultrafast laser pulse through a grating stretcher and Michelson interferometer with variable inter-arm delay. By partially frequency-doubling and focusing the pulse sequence, an air-plasma filament riding a beat note was created to radiate a THz wave with primary pulse characteristics (center frequency and CEP) under coherent control. To reproduce experimental results and elucidate complex nonlinear light-matter interaction, numerical simulation has been performed. This work demonstrates the feasibility of generating coherently controlled narrowband THz wave with high tunability in laser-induced air plasma.

Asymmetric double-pulse interferometric FROG for visible-wavelength time-domain spectroscopy.

To extend the detection range of time-domain spectroscopy into the challenging visible frequencies, we propose an interferometry-type frequency-resolved optical gating (FROG). Our numerical simulation shows that, when operating in a double-pulse scheme, a unique phase-locking mechanism can be activated and preserves both zero- and first-order phases (φ0, φ1)-indispensable for phase-sensitive spectroscopic study-that are otherwise inaccessible to standard FROG measurement. Followed by time-domain signal reconstruction and analysis protocol, we show that time-domain spectroscopy with sub-cycle temporal resolution is enabled and well suits the need of a ultrafast-compatible and ambiguity-free method for complex dielectric function measurement at visible wavelengths.

Photoenhanced metastable c-axis electrodynamics in stripe-ordered cuprate La1.885Ba0.115CuO4.

Quantum materials are amenable to nonequilibrium manipulation with light, enabling modification and control of macroscopic properties. Light-based augmentation of superconductivity is particularly intriguing. Copper-oxide superconductors exhibit complex interplay between spin order, charge order, and superconductivity, offering the prospect of enhanced coherence by altering the balance between competing orders. We utilize terahertz time-domain spectroscopy to monitor the c-axis Josephson plasma resonance (JPR) in La2-xBaxCuO4 (x = 0.115) as a direct probe of superconductivity dynamics following excitation with near-infrared pulses. Starting from the superconducting state, c-axis polarized excitation with a fluence of 100 µJ/cm2 results in an increase of the far-infrared spectral weight by more than an order of magnitude as evidenced by a blueshift of the JPR, interpreted as resulting from nonthermal collapse of the charge order. The photoinduced signal persists well beyond our measurement window of 300 ps and exhibits signatures of spatial inhomogeneity. The electrodynamic response of this metastable state is consistent with enhanced superconducting fluctuations. Our results reveal that La2-xBaxCuO4 is highly sensitive to nonequilibrium excitation over a wide fluence range, providing an unambiguous example of photoinduced modification of order-parameter competition.

Multi-messenger nanoprobes of hidden magnetism in a strained manganite.

The ground-state properties of correlated electron systems can be extraordinarily sensitive to external stimuli, offering abundant platforms for functional materials. Using the multi-messenger combination of atomic force microscopy, cryogenic scanning near-field optical microscopy, magnetic force microscopy and ultrafast laser excitation, we demonstrate both 'writing' and 'erasing' of a metastable ferromagnetic metal phase in strained films of La2/3Ca1/3MnO3 (LCMO) with nanometre-resolved finesse. By tracking both optical conductivity and magnetism at the nanoscale, we reveal how strain-coupling underlies the dynamic growth, spontaneous nanotexture and first-order melting transition of this hidden photoinduced metal. Our first-principles calculations reveal that epitaxially engineered Jahn-Teller distortion can stabilize nearly degenerate antiferromagnetic insulator and ferromagnetic metal phases. We propose a Ginzburg-Landau description to rationalize the co-active interplay of strain, lattice distortions and magnetism nano-resolved here in strained LCMO, thus guiding future functional engineering of epitaxial oxides into the regime of phase-programmable materials.

The enantioselective study of the toxicity effects of chiral acetochlor in HepG2 cells.

Acetochlor is one of the most widely used chiral herbicides in the world, and it is usually produced and used as racemic form (Rac). The potential effects of acetochlor in human body are mainly induced by its residue in agriculture food. The direct target exposed is the liver in human body. However, the potential toxic and mechanism threat to human liver cells caused by chiral acetochlor has been rarely reported. The purpose of this study is to explore the potential mechanism of the toxicity caused by chiral acetochlor in HepG2 cells. The results revealed that acetochlor and its enantiomers could inhibit cell activity and cause DNA damage in HepG2 cells. The toxicity of Rac was higher than that of the two enantiomers, mainly derived from S configuration. The mechanism is through inducing decreased membrane potential (△Ψ), up-regulated Bax/BcL-2 expression, caused a cascade reaction, activated casepase-3 and casepase-9 and cleaved PARP, which maybe lead to cell death through apoptotic-signaling pathway in the end. These results illuminate that the genotoxic and cytotoxic risks of chiral acetochlor are major coming from S configuration. It provides a theoretical basis for the production of single pesticide to reduce the effects of human health.

Observation of spatial self-phase modulation induced via two competing mechanisms.

Two spatial self-phase modulation (SSPM) patterns were observed in suspensions of Bi2TeSe2 nanosheets. Two mechanisms were found to produce SSPM with different occurrence times and power dependence. The Type I (narrow) rings are attributed to the coherent third-order nonlinear optical Kerr effect, which induces self-diffraction in 2D materials, and the Type II (wide) rings are assigned to the contribution of a thermal effect. The nonlinear refractive index of Bi2TeSe2 is found to be 2.30×10-5cm2W-1 at 700 nm. The findings described here provide an explanation for the formation of rings in 2D systems due to SSPM.

Combined Use of Trichoderma atroviride CCTCCSBW0199 and Brassinolide to Control Botrytis cinerea Infection in Tomato.

Tomato gray mold caused by Botrytis cinerea is one of the main diseases of tomato and significantly impacts the yield and quality of tomato fruit. The overuse of chemical fungicides has resulted in the development of fungicide-resistant strains. Biological control is becoming an alternative method for the control of plant diseases to replace or decrease the application of traditional synthetic chemical fungicides and genus Trichoderma is widely used as a biological agent for controlling tomato gray mold. Brassinolide (BR) is a plant-growth-promoting steroid. To enhance the efficiency and stability of Trichoderma activity against B. cinerea, an optimal combination of Trichoderma atroviride CCTCCSBW0199 and BR that controls B. cinerea infection in tomato was identified. Strain CCTCCSBW0199 was found to have antagonistic activity against B. cinerea both in vitro and in vivo. In addition, a fermented culture of chlamydospores and metabolites, or metabolites only of strain CCTCCSBW0199 also reduced growth of B. cinerea. BR reduced growth of B. cinerea and had no effect on the sporulation and growth of Trichoderma spp. An application of metabolites of a Trichoderma sp. + BR reduced gray mold on tomato leaves by approximately 70.0%. Furthermore, the activities of induced defense response-related enzyme, such as peroxidase, superoxide dismutase, catalase, and phenylalanine ammonia-lyase were increased in tomato plants treated with a Trichoderma sp. + BR. Our data suggested that applying a mix of metabolites of T. atroviride CCTCCSBW0199 + BR was effective at reducing gray mold of tomato and may lay a theoretical foundation for the development of novel biofungicides.

Dynamics of a Persistent Insulator-to-Metal Transition in Strained Manganite Films.

Transition metal oxides possess complex free-energy surfaces with competing degrees of freedom. Photoexcitation allows shaping of such rich energy landscapes. In epitaxially strained La_{0.67}Ca_{0.33}MnO_{3}, optical excitation with a sub-100-fs pulse above 2 mJ/cm^{2} leads to a persistent metallic phase below 100 K. Using single-shot optical and terahertz spectroscopy, we show that this phase transition is a multistep process. We conclude that the phase transition is driven by partial charge-order melting, followed by growth of the persistent metallic phase on longer timescales. A time-dependent Ginzburg-Landau model can describe the fast dynamics of the reflectivity, followed by longer timescale in-growth of the metallic phase.

Analysis of the thickness dependence of metamaterial absorbers at terahertz frequencies.

Metamaterial absorbers typically consist of a metamaterial layer, a dielectric spacer layer, and a metallic ground plane. We have investigated the dependence of the metamaterial absorption maxima on the spacer layer thickness and the reflection coefficient of the metamaterial layer obtained in the absence of the ground plane layer. Specifically, we employ interference theory to obtain an analytical expression for the spacer thickness needed to maximize the absorption at a given frequency. The efficacy of this simple expression is experimentally verified at terahertz frequencies through detailed measurements of the absorption spectra of a series of metamaterials structures with different spacer thicknesses. Using an array of split-ring resonators (SRRs) as the metamaterial layer and SU8 as the spacer material we observe that the absorption peaks redshift as the spacer thickness is increased, in excellent agreement with our analysis. Our findings can be applied to guide metamaterial absorber designs and understand the absorption peak frequency shift of sensors based on metamaterial absorbers.

Cooperative photoinduced metastable phase control in strained manganite films.

A major challenge in condensed-matter physics is active control of quantum phases. Dynamic control with pulsed electromagnetic fields can overcome energetic barriers, enabling access to transient or metastable states that are not thermally accessible. Here we demonstrate strain-engineered tuning of La2/3Ca1/3MnO3 into an emergent charge-ordered insulating phase with extreme photo-susceptibility, where even a single optical pulse can initiate a transition to a long-lived metastable hidden metallic phase. Comprehensive single-shot pulsed excitation measurements demonstrate that the transition is cooperative and ultrafast, requiring a critical absorbed photon density to activate local charge excitations that mediate magnetic-lattice coupling that, in turn, stabilize the metallic phase. These results reveal that strain engineering can tune emergent functionality towards proximal macroscopic states to enable dynamic ultrafast optical phase switching and control.

Broadband spatial self-phase modulation of black phosphorous.

Spatial self-phase modulation (SSPM) experiments on two-dimensional (2D) black phosphorus (BP) nanoflake suspensions are performed with focused femtosecond pulsed lasers at 350-1160 nm. In the broadband region, the slope of the SSPM ring number versus laser intensity varies from 0.99 to 0.34, which is larger than 0.25 in MoS2. We deduce the portion of the fluid globe (ξ) to be 0.0067, which is a constant independent of laser intensity, when the laser intensity is above 10 W/cm2. The nonlinear refractive index of BP is measured to be ∼10(-5) cm2 W(-1), and the third-order nonlinear susceptibility is χ(3)∼10(-8) esu at multiple wavelengths.

Immune cells and related cytokines in dilated cardiomyopathy.

Dilated cardiomyopathy (DCM) is a non-ischemic cardiomyopathy involving one or more underlying etiologies. It is characterized by structural and functional dysfunction of the myocardium, potentially leading to fibrosis and ventricular remodeling, and an elevated risk of heart failure (HF). Although the pathogenesis of DCM remains unknown, compelling evidence suggests that DCM-triggered immune cells and inflammatory cascades play a crucial role in the occurrence and development of DCM. Various factors are linked to myocardial damage, inducing aberrant activation of the immune system and sustained inflammatory responses in DCM. The investigation of the immunopathogenesis of DCM also contributes to discovering new biomarkers and therapeutic targets. This review examines the roles of immune cells and related cytokines in DCM pathogenesis and explores immunotherapy strategies in DCM.

Development of machine learning-based malignant pericardial effusion-related model in breast cancer: Implications for clinical significance, tumor immune and drug-therapy.

Background: Malignant pericardial effusion (MPE) is a common complication of advanced breast cancer (BRCA) and plays an important role in BRCA. This study is aims to construct a prognostic model based on MPE-related genes for predicting the prognosis of breast cancer. Methods: The BRCA samples are analyzed based on the expression of MPE-related genes by using an unsupervised cluster analysis method. This study processes the data by least absolute shrinkage and selection operator and multivariate Cox analysis, and uses machine learning algorithms to construct BRCA prognostic model and develop web tool. Results: BRCA patients are classified into three clusters and a BRCA prognostic model is constructed containing 9 MPE-related genes. There are significant differences in signature pathways, immune infiltration, immunotherapy response and drug sensitivity testing between the high and low-risk groups. Of note, a web-based tool (http://wys.helyly.top/cox.html) is developed to predict overall survival as well as drug-therapy response of BRCA patients quickly and conveniently, which can provide a basis for clinicians to formulate individualized treatment plans. Conclusion: The MPE-related prognostic model developed in this study can be used as an effective tool for predicting the prognosis of BRCA and provides new insights for the diagnosis and treatment of BRCA patients.

Association of Cumulative Exposure to Cardiovascular Health Behaviors and Factors with the Onset and Progression of Arterial Stiffness.

AIM: This study aims to explore the association of cumulative exposure to cardiovascular health behaviors and factors with the onset and progression of arterial stiffness. METHODS: In this study, 24,110 participants were examined from the Kailuan cohort, of which 11,527 had undergone at least two brachial-ankle pulse wave velocity (baPWV) measurements. The cumulative exposure to cardiovascular health behaviors and factors (cumCVH) was calculated as the sum of the cumCVH scores between two consecutive physical examinations, multiplied by the time interval between the two. A logistic regression model was constructed to evaluate the association of cumCVH with arterial stiffness. Generalized linear regression models were used to analyze how cumCVH affects baPWV progression. Moreover, a Cox proportional hazards regression model was used to analyze the effect of cumCVH on the risk of arterial stiffness. RESULTS: In this study, participants were divided into four groups, according to quartiles of cumCVH exposure levels, namely, quartile 1 (Q1), quartile 2 (Q2), quartile 3 (Q3), and quartile 4 (Q4). Logistic regression analysis showed that compared with the Q1 group, the incidence of arterial stiffness in terms of cumCVH among Q2, Q3, and Q4 groups decreased by 16%, 30%, and 39%, respectively. The results of generalized linear regression showed that compared with the Q1 group, the incidence of arterial stiffness in the Q3 and Q4 groups increased by -25.54 and -29.83, respectively. The results of Cox proportional hazards regression showed that compared with the Q1 group, the incidence of arterial stiffness in cumCVH among Q2, Q3, and Q4 groups decreased by 11%, 19%, and 22%, respectively. Sensitivity analyses showed consistency with the main results. CONCLUSIONS: High cumCVH can delay the progression of arterial stiffness and reduce the risk of developing arterial stiffness.

Nonlinear terahertz metamaterials via field-enhanced carrier dynamics in GaAs.

We demonstrate nonlinear metamaterial split ring resonators (SRRs) on GaAs at terahertz frequencies. For SRRs on doped GaAs films, incident terahertz radiation with peak fields of ~20-160 kV/cm drives intervalley scattering. This reduces the carrier mobility and enhances the SRR LC response due to a conductivity decrease in the doped thin film. Above ~160 kV/cm, electric field enhancement within the SRR gaps leads to efficient impact ionization, increasing the carrier density and the conductivity which, in turn, suppresses the SRR resonance. We demonstrate an increase of up to 10 orders of magnitude in the carrier density in the SRR gaps on semi-insulating GaAs. Furthermore, we show that the effective permittivity can be swept from negative to positive values with an increasing terahertz field strength in the impact ionization regime, enabling new possibilities for nonlinear metamaterials.

A novel immune checkpoint-related signature for prognosis and immune analysis in breast cancer.

Breast cancer is one of the most prevailing forms of cancer globally. Immunotherapy has demonstrated efficacy in improving the overall survival of breast cancer. The aim of us was to formulate a novel signature predicated on immune checkpoint-related genes (ICGs) that could anticipate the prognosis and further analyze the immune status of patients with breast cancer. After acquiring data, we pinpointed the definitive ICGs for constructing the prognostic model of breast cancer. We constructed a novel prognostic model and created a fresh risk score called Immune Checkpoint-related Risk Score in breast cancer (ICRSBC). The nomogram was constructed to evaluate the accuracy of the model, and the new web-based tool was created to be more intuitive for predicting prognosis. We also investigated immunotherapy responsiveness and analyzed the tumor mutational burden (TMB) in ICRSBC subgroups. The ICRSBC was found to have significant correlations with the immune environment, immunotherapy responsiveness, and TMB. The expression levels of the 9 ICGs that construct the prognostic model and their promoter methylation levels are significantly different between breast cancer and normal tissues. Furthermore, the mutation profiles, the copy number alterations, and the levels of protein expression also exhibit marked disparities among the 9 ICGs. We have identified and validated a novel signature related to ICGs that is strongly associated with breast cancer progression. This signature enables us to create a risk score for prognosticating the survival and assessing the immune status of individuals affected by breast cancer.

Machine learning predictive models for grading bronchopulmonary dysplasia: umbilical cord blood IL-6 as a biomarker.

Objectives: This study aimed to analyze the predictive value of umbilical cord blood Interleukin-6 (UCB IL-6) for the severity-graded BPD and to establish machine learning (ML) predictive models in a Chinese population based on the 2019 NRN evidence-based guidelines. Methods: In this retrospective analysis, we included infants born with gestational age <32 weeks, who underwent UCB IL-6 testing within 24 h of admission to our NICU between 2020 and 2022. We collected their medical information encompassing the maternal, perinatal, and early neonatal phases. Furthermore, we classified the grade of BPD according to the 2019 NRN evidence-based guidelines. The correlation between UCB IL-6 and the grades of BPD was analyzed. Univariate analysis and ordinal logistic regression were employed to identify risk factors, followed by the development of ML predictive models based on XGBoost, CatBoost, LightGBM, and Random Forest. The AUROC was used to evaluate the diagnostic value of each model. Besides, we generated feature importance distribution plots based on SHAP values to emphasize the significance of UCB IL-6 in the models. Results: The study ultimately enrolled 414 preterm infants, with No BPD group (n = 309), Grade 1 BPD group (n = 73), and Grade 2-3 BPD group (n = 32). The levels of UCB IL-6 increased with the grades of BPD. UCB IL-6 demonstrated clinical significance in predicting various grades of BPD, particularly in distinguishing Grade 2-3 BPD patients, with an AUROC of 0.815 (95% CI: 0.753-0.877). All four ML models, XGBoost, CatBoost, LightGBM, and Random Forest, exhibited Micro-average AUROC values of 0.841, 0.870, 0.851, and 0.878, respectively. Notably, UCB IL-6 consistently appeared as the most prominent feature across the feature importance distribution plots in all four models. Conclusion: UCB IL-6 significantly contributes to predicting severity-graded BPD, especially in grade 2-3 BPD. Through the development of four ML predictive models, we highlighted UCB IL-6's importance.