In this work, we introduce fractal acoustic metamaterials (FAMs), in thicknesses ranging from 5 (λ/69) to 25 mm (λ/18), which are observed to provide multiple narrow-band low-frequency absorptions of acoustic signals. The fractal structures used in this work are carefully designed and fabricated using a side branch Helmholtz resonator design, making these structures easily tunable to multiple frequencies. Using different sizes of the side branches distributed in a fractally oriented configuration onto a plane rigid baseplate, the propagation velocity of acoustic waves is slowed down considerably. There is also a shifting resonating response of the structures toward lower frequencies (<1600 Hz). These FAM structures exhibit no dependence on the acoustic traverse length, as is otherwise commonly seen in coiled meta-structures and others. In order to achieve a near-perfect sound absorption behavior, the geometry of the structure is theoretically ascertained and validated numerically and experimentally. Significant emphasis has been placed on the associated physical mechanism modulating the loss of intensity of the incident acoustic signals. Moreover, with regression analysis performed on a response surface-based optimization scheme (using Design Expert 11 software), the geometric parameters are determined in a way that the absorption demonstrates a narrow-band characteristic at a frequency of 1 K Hz. We have shown in this work the tunability aspect of the various absorption frequency bands through appropriate designs of the FAM. It opens up wide application possibilities of multiple frequency sound absorptions (acoustic cloaking).

Design of high-efficiency, low frequency (<1000Hz) soundproof window or wall absorber which is transparent to airflow is presented. Due to the massive rise in human population and modernization, environmental noise has significantly risen globally. Prolonged noise exposure can cause severe physiological and psychological symptoms like nausea, headaches, fatigue, and insomnia. There has been continuous growth in building construction and infrastructure like offices, bus stops, and airports due to urban population. Generally, a ventilated window is used for getting fresh air into the room, but at the same time, unwanted noise comes along. Researchers used traditional approaches like noise barrier mats in front of the window or designed the entire window using sound-absorbing materials. However, this solution is not aesthetically pleasing, and at the same time, it is heavy and not adequate for low-frequency noise shielding. To address this challenge, we design a transparent hexagonal panel based on Sierpiński fractal triangle which is aesthetically pleasing, demonstrates normal incident sound absorption coefficient more than 0.96 around 700 Hz and transmission loss around 23 dB, while maintaining air circulation through triangular cutout. Next, we present a concept of fabrication of large acoustic panel for large-scale applications which lead to suppressing the urban noise pollution

<p>Histologic expression of basal markers in HR-positive breast tumors at different tumor stages. <b>A,</b> Representative sections of HR-positive samples at different tumor stages (LGDCIS, DCIS, and IDC) stained with the indicated basal markers. Scale bar, 50 μm. <b>B,</b> Bar plots representing the percentage of cells expressing each marker in in HR-positive samples across the different tumor stages. Statistics calculated two-way ANOVA. *, <i>P</i> < 0.05; **, <i>P</i> < 0.005; ns, not significant.</p>

<p>Primary antibodies used for immunohistochemistry</p>

<p>TAGL as a predictive marker for dasatinib sensitivity. <b>A,</b> Western blot of control and <i>TAGLN</i>-KO cells in Hs578T (top) and BT-549 (bottom) cells. <b>B,</b> Representative immunofluorescence of Hs578T and BT549 control and <i>TAGLN</i>-KO cells, stained with αTAGL (green) and DAPI (blue). Scale bar, 50 μm. <b>C,</b> Cell proliferation in control (black) and <i>TAGLN</i>-KO (purple) cells measured by MTT assays over 72 hours. <b>D,</b> Relative percentage of migrated cells in control and <i>TAGLN</i>-KO cells, assessed by transwell assays. In <b>C</b> and <b>D</b>, values represent the mean ± SEM of at least three experimental replicates, and statistical significance was determined using one-way ANOVA. <b>E,</b> Drug–response curves for cell viability of control and <i>TAGLN</i>-KO cells treated with dasatinib at increasing concentrations. <b>F,</b> Western blot of known dasatinib targets in control and <i>TAGLN</i>-KO cells. <b>G,</b> Data from the <i>DepMap</i> portal showing the correlation between <i>TAGLN</i> and <i>PDGFRB</i> in breast cancer cell lines. <b>H,</b> Western blot of PDGFRβ in <i>TAGLN</i>-KO and cells and clones constitutively expressing <i>PDGFRB</i>. <b>I,</b> Drug–response curves for cell viability of <i>TAGLN</i>-KO and <i>TAGLN</i>-KO/<i>PBGFRB</i> cells treated with dasatinib at increasing concentrations. In <b>E</b> and <b>I</b>, solid lines represent the mean of three biological replicates performed in technical replicates. The dashed line indicates their IC<sub>50</sub> value. **, <i>P</i> < 0.01; ****, <i>P</i> < 0.0001; ns, not significant.</p>

With a steep rise in the urban population requiring an increased number of buildings, public and private transport systems, urban noise is posing a serious environmental problem affecting health. To attenuate the effect on the well-being of human health, a variety of conventional sound-absorbing materials suitable at mid and higher-frequency noise absorption are commonly being used but low and mid-frequency noise remains a challenge. These applications are further limited by the acoustic performance and ventilation efficiency in conventional noise barrier limits of their fields. Acoustic metamaterial presents a unique solution as an artificially designed material showing low-frequency noise mitigation. A novel subwavelength device having thickness of 15mm (<2 cm) ,with potential application in noise mitigation and air ventilation solution is presented herein. In this study, the design and fabrication of a small prototype based on a Fresnel-spiral shape composed of several arms are performed. Numerical and experimental investigations were carried out to determine the acoustical properties of the proposed ventilated metamaterial in terms of sound absorption and sound transmission loss. The experimental investigation shows significant sound absorption with a high bandwidth (more than one octave in the range of > 900 Hz ), acoustic properties leading to potential applications in urban noise control for low and mid-frequency ranges.

Abstract The direct electrochemical nitric oxide reduction reaction (NORR) is an attractive technique for converting NO into NH 3 with low power consumption under ambient conditions. Optimizing the electronic structure of the active sites can greatly improve the performance of electrocatalysts. Herein, we prepare body‐centered cubic RuGa intermetallic compounds (i.e., bcc RuGa IMCs) via a substrate‐anchored thermal annealing method. The electrocatalyst exhibits a remarkable NH 4 + yield rate of 320.6 μmol h −1 mg −1 Ru with the corresponding Faradaic efficiency of 72.3 % at very low potential of −0.2 V vs. reversible hydrogen electrode (RHE) in neutral media. Theoretical calculations reveal that the electron‐rich Ru atoms in bcc RuGa IMCs facilitate the adsorption and activation of *HNO intermediate. Hence, the energy barrier of the potential‐determining step in NORR could be greatly reduced.

<p>Identification of BaC identity markers expressed in the basal compartment of healthy human breast. <b>A,</b> Schematic representation of a mammary gland duct cross-section, showing BaCs (blue) and LCs cells (red). ERα<sup>pos</sup> and ERα<sup>neg</sup> statuses are indicated by nuclear color. <b>B,</b> Integrated UMAP plot showing epithelial cell clustering from three murine scRNA-seq datasets. Color coding differentiates between BaCs (blue), ERα<sup>pos</sup> LC (red), and ERα<sup>neg</sup> LCs (green). <b>C,</b> UMAP plots showing the signature score of the top 20 DEGs associated with each epithelial compartment. Signature scores are color-coded from low (gray) to high (blue). <b>D,</b> UMAP plots showing expression levels of the top 10 BaC-associated genes across the integrated human dataset. Color gradient indicates expression levels from low (blue) to high (red). <b>E,</b> Representative IHC staining of breast tissue consecutive serial sections showing proteins expression of candidate BaC-associated genes. Scale bar, 50 μm. Arrows in the APOE panel highlight expression restricted to stromal cells. <b>A,</b> Created in BioRender. Rodilla, V. (2026) <a href="https://BioRender.com/qpb7bux" target="_blank">https://BioRender.com/qpb7bux</a>.</p>

Programmable acoustic metamaterials allow to manipulate sound waves at desirable frequency ranges intelligently, which makes it a viable and practical alternative to many noise cancellation applications. These kinds of metamaterials are amenable to intelligent programming and find place in a variety of real-life applications such as acoustic cloaking, noise cancellation, stealth applications, noise focusing, etc., simply with intelligent programming of the microstructure and the control of micro-movement of the various control boundaries instead of rebuilding new structures every time. Metamaterials are artificially designed materials that possess unique, unusual physical and mechanical properties, making them good lightweight candidates for various noise-shielding applications. However, many papers have been published on studying passive kinds of metamaterial structures whose material properties are fixed in space and time once designed and fabricated. This article is about a different class of metamaterials which are programmable and changeable through various control boundaries forming the structures for the applications pertaining to acoustic isolation (vibro-acoustics) and acoustic mitigation. The incorporation of shape memory polymers or smart polymers into the metamaterial structures enables fine and coarse tuning of these structures to the incoming noise frequency spectrum on a real-time basis. This article reviews some recent trends in progress made with smart materials and programmable metamaterials, their various programming techniques, the fundamental concept involved, various design strategies of such materials and their emergent applications in various fields of technology. The current fabrication challenges and future outlook in this promising field are also discussed.

The recent emergence of acoustic metamaterials presents unparalleled possibilities for sound control across diverse scenarios. However, achieving both sound absorption and unrestricted airflow concurrently in a one-dimensional scenario poses a challenge. Most available acoustic metamaterials are designed in 2D or 3D, and in these configurations, a large portion of noise is reflected back. The key challenge, therefore, is how to allow maximum air to pass through the structure, make it tunable and noise be effectively damped within it. To address this, we propose four different types of configurations as KF (Kink Fiber), YAM (“Y” Type kink Fiber), CDAM (Converging Diverging Kink Fiber), and IRAM (Internal Resonator Kink Fiber, a unique one-dimensional design that simultaneously overcomes both challenges. The design subwavelength (7 cm) one-dimensional acoustic meta-structured blanket, demonstrating broadband sound absorption bandwidth of one octave with 0.5-0.9 absorption within the 500-1600 Hz range. In this study, we theoretically (through transfer matrix method), numerically (through FEM), and experimentally (through Impedance tube method) have showcased that this challenge can be surmounted by employing various configurations of kink fiber-based metamaterials. Following the concept developed in this article there have been efforts to develop blankets using hand lay-up method which can be deployed in real-world setup based on one-dimensional acoustic damping concept introduced in this work.

The recent emergence of acoustic metamaterials presents unparalleled possibilities for sound control across diverse scenarios. However, achieving both sound absorption and unrestricted airflow concurrently in a one-dimensional scenario poses a challenge. Most available acoustic metamaterials are designed in 2D or 3D, and in these configurations, a large portion of noise is reflected back. The key challenge, therefore, is how to allow maximum air to pass through the structure, make it tunable and noise be effectively damped within it. To address this, we propose four different types of configurations as KF (Kink Fiber), YAM (“Y” Type kink Fiber), CDAM (Converging Diverging Kink Fiber), and IRAM (Internal Resonator Kink Fiber, a unique one-dimensional design that simultaneously overcomes both challenges. The design subwavelength (7 cm) one-dimensional acoustic meta-structured blanket, demonstrating broadband sound absorption bandwidth of one octave with 0.5–0.9 absorption within the 500–1600 Hz range. In this study, we theoretically (through transfer matrix method), numerically (through FEM), and experimentally (through Impedance tube method) have showcased that this challenge can be surmounted by employing various configurations of kink fiber-based metamaterials. Following the concept developed in this article there have been efforts to develop blankets using hand lay-up method which can be deployed in real-world setup based on one-dimensional acoustic damping concept introduced in this work.

<p>Analysis of basal marker expression and immune checkpoint genes in TNBC</p>