Explore the vast range of titles available.

Polaritons in two-dimensional materials provide extreme light confinement that is difficult to achieve with metal plasmonics. However, such tight confinement inevitably increases optical losses through various damping channels. Here we demonstrate that hyperbolic phonon polaritons in hexagonal boron nitride can overcome this fundamental trade-off. Among two observed polariton modes, featuring a symmetric and antisymmetric charge distribution, the latter exhibits lower optical losses and tighter polariton confinement. Far-field excitation and detection of this high-momenta mode become possible with our resonator design that can boost the coupling efficiency via virtual polariton modes with image charges that we dub ‘image polaritons’. Using these image polaritons, we experimentally observe a record-high effective index of up to 132 and quality factors as high as 501. Further, our phenomenological theory suggests an important role of hyperbolic surface scattering in the damping process of hyperbolic phonon polaritons. The tight confinement of polaritons in 2D materials leads to increased optical losses. Here, the authors demonstrate image phonon polariton modes in hexagonal boron nitride with an antisymmetric charge distribution that feature quality factors of up to 501 and an effective index of 132.

Understanding the function of moisture on perovskite is challenging since the random environmental moisture strongly disturbs the perovskite structure. Here, we develop various N 2 -protected characterization techniques to comprehensively study the effect of moisture on the efficient cesium, methylammonium, and formamidinium triple-cation perovskite (Cs 0.05 FA 0.75 MA 0.20 )Pb(I 0.96 Br 0.04 ) 3 . In contrast to the secondary measurements, the established air-exposure-free techniques allow us directly monitor the influence of moisture during perovskite crystallization. We find a controllable moisture treatment for the intermediate perovskite can promote the mass transportation of organic salts, and help them enter the buried bottom of the films. This process accelerates the quasi-solid-solid reaction between organic salts and PbI 2 , enables a spatially homogeneous intermediate phase, and translates to high-quality perovskites with much-suppressed defects. Consequently, we obtain a champion device efficiency of approaching 24% with negligible hysteresis. The devices exhibit an average T 80 -lifetime of 852 h (maximum 1210 h) working at the maximum power point. Perovskite structure is disturbed by environmental moisture, limiting the device performance. Here, Wei et al. monitor the effect of moisture during the growth by N 2 -protected characterization techniques, and obtain an operationally stable perovskite solar cell with efficiency approaching 24%.

Waves impart momentum and exert force on obstacles in their path. The transfer of wave momentum is a fundamental mechanism for contactless manipulation, yet the rules of conventional scattering intrinsically limit the radiation force based on the shape and the size of the manipulated object. Here, we show that this intrinsic limit can be broken for acoustic waves with subwavelength-structured surfaces (metasurfaces), where the force becomes controllable by the arrangement of surface features, independent of the object’s overall shape and size. Harnessing such anomalous metasurface scattering, we demonstrate complex actuation phenomena: self-guidance, where a metasurface object is autonomously guided by an acoustic wave, and tractor beaming, where a metasurface object is pulled by the wave. Our results show that bringing the metasurface physics of acoustic waves, and its full arsenal of tools, to the domain of mechanical manipulation opens new frontiers in contactless actuation and enables diverse actuation mechanisms that are beyond the limits of traditional wave-matter interactions. Here, the authors demonstrate that acoustic waves can actuate and guide large objects based on subwavelength meta-patterns on their surface.

cGAS is a sensor of cytosolic DNA and responds equally to exogenous and endogenous DNA. After recognition of cytosolic dsDNA or ssDNA, cGAS synthesizes the second messenger 2′3′-cGAMP, which then binds to and activates stimulator of interferon genes (STING). STING plays an essential role in responding to pathogenic DNA and self-DNA in the context of autoimmunity. In pathologic conditions, such as stroke or hypoxia-ischemia (HI), DNA can gain access into the cytoplasm of the cell and leak from the dying cells into the extracellular environment, which potentially activates cGAS/STING. Recent in vivo studies of myocardial ischemia, traumatic brain injury, and liver damage models suggest that activation of cGAS/STING is not only a side-effect of the injury, but it can also actively contribute to cell death and apoptosis. We found, for the first time, that cGAS/STING pathway becomes activated between 24 and 48 h after HI in a 10-day-old rat model. Silencing STING with siRNA resulted in decreased infarction area, reduced cortical neurodegeneration, and improved neurobehavior at 48 h, suggesting that STING can contribute to injury progression after HI. STING colocalized with lysosomal marker LAMP-1 and blocking STING reduced the expression of cathepsin B and decreased the expression of Bax and caspase 3 cleavage. We observed similar protective effects after intranasal treatment with cGAS inhibitor RU.521, which were reversed by administration of STING agonist 2′3′-cGAMP. Additionally, we showed that long interspersed element 1 (LINE-1) retrotransposon, a potential upstream activator of cGAS/STING pathway was induced at 48 h after HI, which was evidenced by increased expression of ORF1p and ORF2p proteins and increased LINE-1 DNA content in the cytosol. Blocking LINE-1 with the nucleoside analog reverse-transcriptase inhibitor (NRTI) stavudine reduced infarction area, neuronal degeneration in the cerebral cortex, and reduced the expression of Bax and cleaved caspase 3. Thus, our results identify the cGAS/STING pathway as a potential therapeutic target to inhibit delayed neuronal death after HI.

Constructing 2D/3D perovskite heterojunctions is effective for the surface passivation of perovskite solar cells (PSCs). However, previous reports that studying perovskite post-treatment only physically deposits 2D perovskite on the 3D perovskite, and the bulk 3D perovskite remains defective. Herein, we propose Cl 2 -dissolved chloroform as a multifunctional solvent for concurrently constructing 2D/3D perovskite heterojunction and inducing the secondary growth of the bulk grains. The mechanism of how Cl 2 affects the performance of PSCs is clarified. Specifically, the dissolved Cl 2 reacts with the 3D perovskite, leading to Cl/I ionic exchange and Ostwald ripening of the bulk grains. The generated Cl − further diffuses to passivate the bulk crystal and buried interface of PSCs. Hexylammonium bromide dissolved in the solvent reacts with the residual PbI 2 to form 2D/3D heterojunctions on the surface. As a result, we achieved high-performance PSCs with a champion efficiency of 24.21% and substantially improved thermal, ambient, and operational stability. Constructing 2D/3D perovskite heterojunctions is effective for the surface passivation of perovskite solar cells. Here, the authors apply Cl 2 -dissolved chloroform as a multifunctional solvent and achieve a champion device efficiency of 24.21% with improved thermal, ambient and operational stability.

Let $\\Gamma $ be a finite set, and $X\\ni x$ a fixed kawamata log terminal germ. For any lc germ $(X\\ni x,B:=\\sum _{i} b_iB_i)$ , such that $b_i\\in \\Gamma $ , Nakamura’s conjecture, which is equivalent to the ascending chain condition conjecture for minimal log discrepancies for fixed germs, predicts that there always exists a prime divisor E over $X\\ni x$ , such that $a(E,X,B)=\\mathrm {mld}(X\\ni x,B)$ , and $a(E,X,0)$ is bounded from above. We extend Nakamura’s conjecture to the setting that $X\\ni x$ is not necessarily fixed and $\\Gamma $ satisfies the descending chain condition, and show it holds for surfaces. We also find some sufficient conditions for the boundedness of $a(E,X,0)$ for any such E.

Eco-friendly Sn-based perovskites show significant potential for high-performance second near-infrared window light-emitting diodes (900 nm – 1700 nm). Nevertheless, achieving efficient and stable Sn-based perovskite second near-infrared window light-emitting diodes remains challenging due to the propensity of Sn 2+ to oxidize, resulting in detrimental Sn 4+ -induced defects and compromised device performance. Here, we present a targeted strategy to eliminate Sn 4+ -induced defects through moisture-triggered hydrolysis of tin tetrahalide, without degrading Sn 2+ in the CsSnI 3 film. During the moisture treatment, tin tetrahalide is selectively hydrolyzed to Sn(OH) 4 , which provides sustained protection. As a result, we successfully fabricate second near-infrared window light-emitting diodes emitting at 945 nm, achieving a performance breakthrough with an external quantum efficiency of 7.6% and an operational lifetime reaching 82.6 h. Guan et al. report a strategy of moisture-triggered selective hydrolysis of Sn4+ into Sn(OH)4, eliminating Sn4 + -induced defects in tin-based perovskites and enhancing the electron injection in NIR-II LED devices with peak emission of 945 nm and external quantum efficiency of 7.6%.

Recurrent pregnancy loss (RPL) profoundly impacts not only the physical health but also the psychological well-being of women. Despite its profound effects, the underlying pathophysiological mechanisms of RPL remain largely elusive, with few discernible warning signs. Lymphocyte activation gene-3 (LAG-3) is a crucial immune checkpoint that modulates immune responses during infection and tumor. In the present study, we examined the expression of LAG-3 on CD4 + T cells during pregnancy via cytometry by time-of-flight and flow cytometry. Our findings revealed a higher frequency of LAG-3 + decidual CD4 + T (dCD4 + T) cells in response to trophoblasts during normal pregnancy. This specific LAG-3 + subset of dCD4 + T cells was found to produce a greater number of anti-inflammatory cytokines. Notably, blocking LAG-3 was highly effective in inhibiting the production of anti-inflammatory cytokines, which is detrimental to the maintenance of pregnancy. A decrease in the number of LAG-3 + dCD4 + T cells was correlated with miscarriage. Interestingly, the RNA level of LAG-3 (data analyzed from the two published single-cell databases) remained stable in RPL. Palmitoylation might play a role in regulating LAG-3 expression during RPL, as the palmitoylation of LAG-3 + dCD4 + T cells was increased in RPL. Additionally, the general palmitoylation inhibitor 2-bromopalmitate was found to upregulate LAG-3 expression on dCD4 + T cells both in vitro and in vivo. Collectively, these findings highlighted the significant roles of LAG-3 in regulating the function of dCD4 + T cell and maintaining normal pregnancy. Furthermore, they suggested that lower LAG-3 expression on dCD4 + T cells could serve as a potential biomarker for diagnosis of RPL.

This study aims to evaluate and compare the carbon emissions and reduction strategies of two different slope construction methods—concrete slope protection and ecological sprayed-soil slope protection—using a life-cycle assessment (LCA) approach. The research focuses on identifying key carbon emission sources throughout each stage of the construction, from material production to transportation, construction, and maintenance, with a particular emphasis on the ecological benefits of vegetation in reducing carbon footprints. Results indicate that the ecological slope protection scheme significantly outperforms the concrete scheme, reducing total carbon emissions by 667.21 tons. Furthermore, the ecological solution, due to its carbon sequestration capabilities, is projected to achieve carbon neutrality within 3.66 years after completion, offering a net carbon sequestration benefit of 2422.97 tons over its lifecycle. Optimization strategies across various stages—material production, transportation, construction, and maintenance—further reduce emissions by 56.8%, underscoring the potential for ecological slope protection to contribute to sustainable construction practices. This study not only provides valuable insights into low-carbon construction methods but also highlights the importance of integrating ecological and engineering technologies to meet global carbon reduction goals.

Background This study aims to explore machine learning(ML) methods for non-invasive assessment of WHO/ISUP nuclear grading in clear cell renal cell carcinoma(ccRCC) using contrast-enhanced ultrasound(CEUS) radiomics. Methods This retrospective study included 122 patients diagnosed as ccRCC after surgical resection. They were divided into a training set ( n  = 86) and a testing set( n  = 36). CEUS radiographic features were extracted from CEUS images, and XGBoost ML models (US, CP, and MP model) with independent features at different phases were established. Multivariate regression analysis was performed on the characteristics of different radiomics phases to determine the indicators used for developing the prediction model of the combined CEUS model and establishing the XGBoost model. The training set was used to train the above four kinds of radiomics models, which were then tested in the testing set. Radiologists evaluated tumor characteristics, established a CEUS reading model, and compared the diagnostic efficacy of CEUS reading model with independent characteristics and combined CEUS model prediction models. Results The combined CEUS radiomics model demonstrated the best performance in the training set, with an area under the curve (AUC) of 0.84, accuracy of 0.779, sensitivity of 0.717, specificity of 0.879, positive predictive value (PPV) of 0.905, and negative predictive value (NPV) of0.659. In the testing set, the AUC was 0.811, with an accuracy of 0.784, sensitivity of 0.783, specificity of 0.786, PPV of 0.857, and NPV of 0.688. Conclusions The radiomics model based on CEUS exhibits high accuracy in non-invasive prediction of ccRCC. This model can be utilized for non-invasive detection of WHO/ISUP nuclear grading of ccRCC and can serve as an effective tool to assist clinical decision-making processes.