Experimental investigation of acoustic moiré effect controlled by twisted bilayer gratings.

Recently, the moiré pattern has attracted lots of attention by superimposing two planar structures of regular geometries, such as two sets of metasurfaces or gratings. Here, we show the experimental investigation of acoustic moiré effect by using twisted bilayer gratings (i.e., one grating twisted with respect to the other). We observed the guided resonance that occurred when the incident ultrasound beam was coupled with the guiding modes in a meta-grating, significantly influencing the reflection and transmission. Tunable guided resonances from the moiré effect with complete ultrasound reflection at different frequencies were further demonstrated in experiments. Combining the measurements of transmission spectra and the Fast Fourier Transform analyses, we reveal the guided resonance frequencies of moiré ultrasonic metasurface can be effectively controlled by adjusting the twisting angle of the bilayer gratings. Our results can be explained in a simplified model based on the band folding theory, providing a reliable prediction on the precise control of ultrasound reflection via the twisting angle adjustment. Our work extends the moiré metasurface from optics into acoustics, which shows more possibilities for the ultrasound beam engineering from the moiré effect and enables the exploration of functional acoustic devices for ultrasound imaging, treatment and diagnosis.

Observation of parity-time symmetry in diffusive systems.

Phase modulation has scarcely been mentioned in diffusive physical systems because the diffusion process does not carry the momentum like waves. Recently, non-Hermitian physics provides a unique perspective for understanding diffusion and shows prospects in thermal phase regulation, exemplified by the discovery of anti-parity-time (APT) symmetry in diffusive systems. However, precise control of thermal phase remains elusive hitherto and can hardly be realized, due to the phase oscillations. Here we construct the PT-symmetric diffusive systems to achieve the complete suppression of thermal phase oscillation. The real coupling of diffusive fields is readily established through a strong convective background, and the decay-rate detuning is enabled by thermal metamaterial design. We observe the phase transition of PT symmetry breaking with the symmetry-determined amplitude and phase regulation of coupled temperature fields. Our work shows the existence of PT symmetry in dissipative energy exchanges and provides unique approaches for harnessing the mass transfer of particles, wave dynamics in strongly scattering systems, and thermal conduction.

Observation of non-Hermitian skin effect in thermal diffusion.

The paradigm shift of Hermitian systems into the non-Hermitian regime profoundly modifies inherent property of the topological systems, leading to various unprecedented effects such as the non-Hermitian skin effect (NHSE). In the past decade, the NHSE has been demonstrated in quantum, optical and acoustic systems. Beside those wave systems, the NHSE in diffusive systems has not yet been observed, despite recent abundant advances in the study of topological thermal diffusion. In this work, we design a thermal diffusion lattice based on a modified Su-Schrieffer-Heeger model and demonstrate the diffusive NHSE. In the proposed model, the asymmetric temperature field coupling inside each unit cell can be judiciously realized by appropriate configurations of structural parameters. We find that the temperature fields trend to concentrate toward the target boundary which is robust against initial excitation conditions. We thus experimentally demonstrated the NHSE in thermal diffusion and verified its robustness against various defects. Our work provides a platform for exploration of non-Hermitian physics in the diffusive systems, which has important applications in efficient heat collection, highly sensitive thermal sensing and others.

The impact of career calling on nurse burnout: A moderated mediation model.

AIM: To evaluate the mediating roles of occupational resilience and the moderationg role of perceived organizational support in the relationship between career calling and nurse burnout. BACKGROUND: Burnout is a frequent and serious problem in the field of nursing, and it poses a serious threat to both nurses' health and patient safety. Although many studies have described the links between burnout, career calling, and occupational resilience, little is known about the actual mechanisms between career calling and nurse burnout. METHODS: A cross-sectional study of 615 nurses in China was conducted using a convenience sampling method. The data were analyzed using descriptive statistics and Pearson correlation analysis. Hypotheses were tested using structural equation models and bootstrapping methods. STROBE guidelines were followed. RESULTS: Career calling was found to be negatively associated with nurse burnout, and occupational resilience mediated the relationship between career calling and burnout. Additionally, perceived organizational support was found to play a moderating role in the relationship between occupational resilience and burnout. CONCLUSION: Career calling can reduce burnout by increasing nurses' levels of occupational resilience, and perceived organizational support moderates this mechanism. Hence, policies focused on encouraging and sustaining career calling should be provided by nurse managers in order to enhance stress resistance and reduce burnout.

Risk factors for one-year mortality following discharge in patients with acute aortic dissection: development and validation of a predictive model in a cross-sectional study.

PURPOSE: This study was aimed to identify the risk factors that influence the mortality risk in patients with acute aortic dissection (AAD) within one year after discharge, and aimed to construct a predictive model for assessing mortality risk. METHODS: The study involved 320 adult patients obtained from the Medical Information Mart for Intensive Care (MIMIC) database. Logistic regression analysis was conducted to identify potential risk factors associated with mortality in AAD patients within one year after discharge and to develop a predictive model. The performance of the predictive model was assessed using the receiver operating characteristic curve (ROC), calibration curve, and decision curve analysis (DCA). To further validate the findings, patient data from the First Affiliated Hospital of Guangxi Medical University (157 patients) were analyzed. RESULTS: Univariate and multivariate logistic regression analyses revealed that gender, length of hospital stay, highest blood urea nitrogen (BUN_max), use of adrenaline, and use of amiodarone were significant risk factors for mortality within one year after discharge (p < 0.05). The constructed model exhibited a consistency index (C-index) and an area under the ROC curve of 0.738. The calibration curve and DCA demonstrated that these indicators had a good degree of agreement and utility. The external validation results of the model also indicated good predictability (AUC = 0.700, p < 0.05). CONCLUSION: The personalized scoring prediction model constructed by gender, length of hospital stays, BUN_max levels, as well as the use of adrenaline and amiodarone, can effectively identify AAD patients with high mortality risk within one year after discharge.

[Research progress in Astragali Radix and its active ingredients in treatment of lung cancer].

Lung cancer is the leading cause of cancer death, and its effective treatment is a difficult medical problem. Lung cancer belongs to the traditional Chinese medicine(TCM) disease categories of lung accumulation, lung amassment, and overstrain cough. Rich theoretical basis and practical experience have been accumulated in the TCM treatment of lung cancer. Astragali Radix is one of the representatives of Qi-tonifying drugs. It mainly treat the lung cancer with the syndrome of Qi deficiency and pathogen stagnation, following the principle of reinforcing healthy Qi and eliminating patgogenic Qi. Astragali Radix exerts a variety of pharmacological activities in the treatment of lung cancer, including inhibiting tumor cell proliferation and promoting tumor cell apoptosis, inhibiting tumor invasion and migration, regulating the tumor microenvironment, suppressing tumor angiogenesis, modulating autophagy, inducing macrophage polarization, enhancing immunity, inhibiting immune escape, and reversing cisplatin resistance. The active ingredients of Astragali Radix in treating lung cancer include polysaccharides, saponins, and flavonoids. This study reviewed the pharmacological activities and active ingredients of Astragali Radix in the treatment of lung cancer, providing a basis for the development and utilization of Astragali Radix resources and active ingredients and the research and development of anti-tumor drugs.

Robust temporal adiabatic passage with perfect frequency conversion between detuned acoustic cavities.

For classical waves, phase matching is vital for enabling efficient energy transfer in many scenarios, such as waveguide coupling and nonlinear optical frequency conversion. Here, we propose a temporal quasi-phase matching method and realize robust and complete acoustical energy transfer between arbitrarily detuned cavities. In a set of three cavities, A, B, and C, the time-varying coupling is established between adjacent elements. Analogy to the concept of stimulated Raman adiabatic passage, amplitudes of the two couplings are modulated as time-delayed Gaussian functions, and the couplings' signs are periodically flipped to eliminate temporal phase mismatching. As a result, robust and complete acoustic energy transfer from A to C is achieved. The non-reciprocal frequency conversion properties of our design are demonstrated. Our research takes a pivotal step towards expanding wave steering through time-dependent modulations and is promising to extend the frequency conversion based on state evolution in various linear Hermitian systems to nonlinear and non-Hermitian regimes.

Acoustic Higher-Order Topological Insulators Induced by Orbital-Interactions.

The discovery of higher-order topological insulator metamaterials, in analogy with their condensed-matter counterparts, has enabled various breakthroughs in photonics, mechanics, and acoustics. A common way of inducing higher-order topological wave phenomena is through pseudo-spins, which mimic the electron spins as a symmetry-breaking degree of freedom. Here we exploit degenerate orbitals in acoustic resonant cavities to demonstrate versatile, orbital-selective, higher-order topological corner states. Type-II corner states are theoretically investigated and experimentally demonstrated based on tailored orbital interactions, without the need for long-range hoppings that has so far served as a key ingredient for Type-II corner states in single-orbital systems. Due to the orthogonal nature of the degenerate p orbitals, we also introduce a universal strategy to realize orbital-dependent edge modes, featuring high-Q edge states identified in bulk bands. Our findings provide an understanding of the interplay between acoustic orbitals and topology, shedding light on orbital-related topological wave physics, as well as its applications for acoustic sensing and trapping. This article is protected by copyright. All rights reserved.

C-reactive protein to albumin ratio predict responses to programmed cell death-1 inhibitors in hepatocellular carcinoma patients.

BACKGROUND: Over the years, programmed cell death-1 (PD-1) inhibitors have been routinely used for hepatocellular carcinoma (HCC) treatment and yielded improved survival outcomes. Nonetheless, significant heterogeneity surrounds the outcomes of most studies. Therefore, it is critical to search for biomarkers that predict the efficacy of PD-1 inhibitors in patients with HCC. AIM: To investigate the role of the C-reactive protein to albumin ratio (CAR) in evaluating the efficacy of PD-1 inhibitors for HCC. METHODS: The clinical data of 160 patients with HCC treated with PD-1 inhibitors from January 2018 to November 2022 at the First Affiliated Hospital of Guangxi Medical University were retrospectively analyzed. RESULTS: The optimal cut-off value for CAR based on progression-free survival (PFS) was determined to be 1.20 using x-tile software. Cox proportional risk model was used to determine the factors affecting prognosis. Eastern Cooperative Oncology Group performance status [hazard ratio (HR) = 1.754, 95% confidence interval (95%CI) = 1.045-2.944, P = 0.033], CAR (HR = 2.118, 95%CI = 1.057-4.243, P = 0.034) and tumor number (HR = 2.932, 95%CI = 1.246-6.897, P = 0.014) were independent prognostic factors for overall survival. CAR (HR = 2.730, 95%CI = 1.502-4.961, P = 0.001), tumor number (HR = 1.584, 95%CI = 1.003-2.500, P = 0.048) and neutrophil to lymphocyte ratio (HR = 1.120, 95%CI = 1.022-1.228, P = 0.015) were independent prognostic factors for PFS. Two nomograms were constructed based on independent prognostic factors. The C-index index and calibration plots confirmed that the nomogram is a reliable risk prediction tool. The ROC curve and decision curve analysis confirmed that the nomogram has a good predictive effect as well as a net clinical benefit. CONCLUSION: Overall, we reveal that the CAR is a potential predictor of short- and long-term prognosis in patients with HCC treated with PD-1 inhibitors. If further verified, CAR-based nomogram may increase the number of markers that predict individualized prognosis.

In Situ Growth of High-Quality Single-Crystal Twisted Bilayer Graphene on Liquid Copper.

Twisted bilayer graphene (TBG) generates significant attention in the fundamental research of 2D materials due to its distinct twist-angle-dependent properties. Exploring the efficient production of TBG with a wide range of twist angles stands as one of the major frontiers in moiré materials. Here, the local space-confined chemical vapor deposition growth technique for high-quality single-crystal TBG with twist angles ranging from 0° to 30° on liquid copper substrates is reported. The clean surface, pristine interface, high crystallinity, and thermal stability of TBG are verified by using comprehensive characterization techniques including optical microscopy, electron microscopy, and secondary-ion mass spectrometry. The proportion of TBG in bilayer graphene reaches as high as 89%. In addition, the stacking structure and growth mechanism of TBG are investigated, revealing that the second graphene layer develops beneath the first one. A series of comparative experiments illustrates that the liquid copper surface, with its excellent fluidity, promotes the growth of TBG. Electrical measurements show the twist-angle-dependent electronic properties of as-grown TBG, achieving a room-temperature carrier mobility of 26640 cm2 V-1 s-1 . This work provides an approach for the in situ preparation of 2D twisted materials and facilitates the application of TBG in the fields of electronics.

3D Covalent Organic Frameworks from Design, Synthesis to Applications in Optoelectronics.

Covalent organic frameworks (COFs), a new class of crystalline materials connected by covalent bonds, have been developed rapidly in the past decades. However, the research on COFs is mainly focused on two-dimensional (2D) COFs, and the research on three-dimensional (3D) COFs is still in the initial stage. In 2D COFs, the covalent bonds exist only in the 2D flakes and can form 1D channels, which hinder the charge transport to some extent. In contrast, 3D COFs have a more complex pore structure and thus exhibit higher specific surface area and richer active sites, which greatly enhance the 3D charge carrier transport. Therefore, compared to 2D COFs, 3D COFs have stronger applicability in energy storage and conversion, sensing, and optoelectronics. In this review, it is first introduced the design principles for 3D COFs, and in particular summarize the development of conjugated building blocks in 3D COFs, with a special focus on their application in optoelectronics. Subsequently, the preparation of 3D COF powders and thin films and methods to improve the stability and functionalization of 3D COFs are summarized. Moreover, the applications of 3D COFs in electronics are outlined. Finally, conclusions and future research directions for 3D COFs are presented.

Orbital topological edge states and phase transitions in one-dimensional acoustic resonator chains.

Topological phases of matter have attracted significant attention in recent years, due to the unusual robustness of their response to defects and disorder. Various research efforts have been exploring classical and quantum topological wave phenomena in engineered materials, in which different degrees of freedom (DoFs) - for the most part based on broken crystal symmetries associated with pseudo-spins - induce synthetic gauge fields that support topological phases and unveil distinct forms of wave propagation. However, spin is not the only viable option to induce topological effects. Intrinsic orbital DoFs in spinless systems may offer a powerful alternative platform, mostly unexplored to date. Here we reveal orbital-selective wave-matter interactions in acoustic systems supporting multiple orbital DoFs, and report the experimental demonstration of disorder-immune orbital-induced topological edge states in a zigzag acoustic 1D spinless lattice. This work expands the study of topological phases based on orbitals, paving the way to explore other orbital-dependent phenomena in spinless systems.

Spacer Engineering Enables Fine-Tuned Thin Film Microstructure and Efficient Charge Transport for Ultrasensitive 2D Perovskite-Based Heterojunction Phototransistors and Optoelectronic Synapses.

2D Ruddlesden-Popper phase layered perovskites (RPLPs) hold great promise for optoelectronic applications. In this study, a series of high-performance heterojunction phototransistors (HPTs) based on RPLPs with different organic spacer cations (namely butylammonium (BA+ ), cyclohexylammonium (CyHA+ ), phenethylammonium (PEA+ ), p-fluorophenylethylammonium (p-F-PEA+ ), and 2-thiophenethylammonium (2-ThEA+ )) are fabricated successfully, in which high-mobility organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene is adopted to form type II heterojunction channels with RPLPs. The 2-ThEA+ -RPLP-based HPTs show the highest photosensitivity of 3.18 × 107 and the best detectivity of 9.00 × 1018 Jones, while the p-F-PEA+ -RPLP-based ones exhibit the highest photoresponsivity of 5.51 × 106 A W-1 and external quantum efficiency of 1.32 × 109 %, all of which are among the highest reported values to date. These heterojunction systems also mimicked several optically controllable fundamental characteristics of biological synapses, including excitatory postsynaptic current, paired-pulse facilitation, and the transition from short-term memory to long-term memory states. The device based on 2-ThEA+ -RPLP film shows an ultra-high PPF index of 234%. Moreover, spacer engineering brought fine-tuned thin film microstructures and efficient charge transport/transfer, which contributes to the superior photodetection performance and synaptic functions of these RPLP-based HPTs. In-depth structure-property correlations between the organic spacer cations/RPLPs and thin film microstructure/device performance are systematically investigated.

[Research progress in pharmacological effects and chemical components of processed Angelicae Sinensis Radix products].

Angelicae Sinensis Radix is one of the main Chinese medicinal materials with both medicinal and edible values. It has the functions of tonifying and activating blood, regulating menstruation and relieving pain, and moistening intestines to relieve constipation. It is mainly produced in the southeastern Gansu province, and that produced in Minxian, Gansu is praised for the best quality. The chemical components of Angelicae Sinensis Radix mainly include volatile oils, organic acids, and polysaccharides, which have anti-inflammatory, pain-relieving, anti-tumor, anti-oxidation, immunomodulatory and other pharmacological effects. Therefore, this medicinal material is widely used in clinical practice. By reviewing the relevant literature, this study systematically introduced the research status about the chemical constituents and pharmacological effects of processed Angelicae Sinensis Radix products, aiming to provide a theoretical reference and support for the future research, development, and clinical application of related drugs.

Construction and Validation of a Novel Nomogram for Predicting the Risk of Metastasis in a Luminal B Type Invasive Ductal Carcinoma Population.

Background: Postoperative distant metastasis is the main cause of death in breast cancer patients. We aimed to construct a nomogram to predict the risk of metastasis of luminal B type invasive ductal carcinoma. Methods: We applied the data of 364 luminal B type breast cancer patients between 2008 and 2013. Patients were categorized into modeling group and validation group randomly (1:1). The breast cancer metastasis nomogram was developed from the logistic regression model using clinicopathological variables. The area under the receiver-operating characteristic curve (AUC) was calculated in modeling group and validation group to evaluate the predictive accuracy of the nomogram. Results: The multivariate logistic regression analysis showed that tumor size, No. of the positive level 1 axillary lymph nodes, human epidermal growth factor receptor 2 (HER2) status and Ki67 index were the independent predictors of the breast cancer metastasis. The AUC values of the modeling group and the validation group were 0.855 and 0.818, respectively. The nomogram had a well-fitted calibration curve. The positive and negative predictive values were 49.3% and 92.7% in the modeling group, and 47.9% and 91.0% in the validation group. Patients who had a score of 60 or more were thought to have a high risk of breast cancer metastasis. Conclusions: The nomogram has a great predictive accuracy of predicting the risk of breast cancer metastasis. If patients had a score of 60 or more, necessary measures, like more standard treatment methods and higher treatment adherence of patients, are needed to take to lower the risk of metastasis and improve the prognosis.

Controllable Synthesis and Growth Mechanism of Interlayer-Coupled Multilayer Graphene.

The potential applications of multilayer graphene in many fields, such as superconductivity and thermal conductivity, continue to emerge. However, there are still many problems in the growth mechanism of multilayer graphene. In this paper, a simple control strategy for the preparation of interlayer-coupled multilayer graphene on a liquid Cu substrate was developed. By adjusting the flow rate of a carrier gas in the CVD system, the effect for finely controlling the carbon source supply was achieved. Therefore, the carbon could diffuse from the edge of the single-layer graphene to underneath the layer of graphene and then interlayer-coupled multilayer graphene with different shapes were prepared. Through a variety of characterization methods, it was determined that the stacked mode of interlayer-coupled multilayer graphene conformed to AB-stacking structure. The small multilayer graphene domains stacked under single-layer graphene was first found, and the growth process and growth mechanism of interlayer-coupled multilayer graphene with winged and umbrella shapes were studied, respectively. This study reveals the growth mechanism of multilayer graphene grown by using a carbon source through edge diffusion, paving the way for the controllable preparation of multilayer graphene on a liquid Cu surface.

Polydatin protects against calcium oxalate crystal-induced renal injury through the cytoplasmic/mitochondrial reactive oxygen species-NLRP3 inflammasome pathway.

BACKGROUND: Oxidative stress and inflammatory responses are critical factors in calcium oxalate (CaOx) crystal-induced renal injury. Reactive oxygen species (ROS) are usually produced in the cytoplasm and mitochondria and trigger the priming and activation of the NLRP3 inflammasome, thereby regulating cytokines and inflammation. Polydatin is a plant rhizome extract with anti-inflammatory, antioxidant, and antitumor effects. However, it remains not clear whether and how these pathophysiological processes exists in CaOx crystal-induced renal inflammatory injury. METHODS: Here, we measured the expression of the NLRP3 inflammasome, IL-18, IL-1ß, intracellular and mitochondrial ROS (mtROS) levels and relevant morphological changes in treated renal tubular epithelial cells (TECs) and stone-forming rats. The study further explored the action of intracellular ROS and mtROS on these inflammatory damage, and the beneficial effects and pathway of polydatin. RESULTS: We verified that CaOx crystal-induced cytoplasmic ROS and mtROS upregulation promoted the priming and activation of the NLRP3 inflammasome, thereby stimulating IL-18/1ß maturation and activation. Polydatin can relieve oxidative stress and inflammatory damage by decreasing ROS. We further demonstrated that mtROS is the main target for polydatin to exert the NLRP3 inflammasome-regulating function. The inhibition of mtROS can effectively relieve the inflammatory damage to TECs and kidney caused by CaOx crystal. CONCLUSION: These findings provide new insight into the relationship between mitochondrial damage and inflammation in nephrolithiasis and show that polydatin-mediated anti-inflammatory and antioxidative protection is a therapeutic strategy for, but not limited to, crystalline nephropathy.

A new species of the genus Leptobrachella Smith 1925 (Amphibia, Anura, Megophryidae) from Guangxi, China.

A new species of Leptobrachella, L.wumingensissp. nov., was described from the Damingshan National Nature Reserve, Wuming District, Nanning City, Guangxi, China based on morphological, molecular and bioacoustic data. Phylogenetic analysis of 16S mtDNA fragments revealed that the new species is closely related to L.damingshanensis. Uncorrected p-distances between the new species and all homologous DNA sequences available for the 16S gene of Leptobrachella are greater than 7.1%. Morphologically, L.wumingensissp. nov. differs from its congeners in several ways, including a medium body size (SVL 26.0-26.7 mm in males, 30.6-34.8 mm in females), lack of toe webbing and lateral fringes, shagreened and granular dorsal surface, pale brown dorsum with darker brown markings, iris bicolored, with the upper half copper and fading to silver in the lower half, and the presence of small irregular black spots and tangerine tubercles on the flanks. Furthermore, we found the new species to have two types of advertisement calls and relatively high dominant frequencies, making it distinct from its congeners.

Magnetoresistance in Organic Spin Valves Based on Acid-Exfoliated 2D Covalent Organic Frameworks Thin Films.

Covalent organic frameworks (COFs), as a burgeoning class of crystalline porous materials, have made significant progress in their application to optoelectronic devices such as field-effect transistors, memristors, and photodetectors. However, the insoluble features of microcrystalline two-dimensional (2D) COF powders limit development of their thin film devices. Additionally, the exploration of spin transport properties in this category of π-conjugated skeleton materials remains vacant thus far. Herein, an imine-linked 2D Py-Np COF nanocrystalline powder was synthesized by Schiff base condensation of 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and naphthalene-2,6-dicarbaldehyde. Then, we prepared a large-scale free-standing Py-Np COF film via a top-down strategy of chemically assisted acid exfoliation. Moreover, high-quality COF films acted as active layers were transferred onto ferromagnetic La0.67 Sr0.33 MnO3 (LSMO) electrodes for the first attempt to fabricate organic spin valves (OSVs) based on 2D COF materials. This COF-based OSV device with a configuration of LSMO/Py-Np COF/Co/Au demonstrated a remarkable magnetoresistance (MR) value up to -26.5 % at 30 K. Meanwhile, the MR behavior of the COF-based OSVs exhibited a highly temperature dependence and operational stability. This work highlights the enormous application prospects of 2D COFs in organic spintronics and provides a promising approach for developing electronic and spintronic devices based on acid-exfoliated COF thin films.

Decorated bacteria-cellulose ultrasonic metasurface.

Cellulose, as a component of green plants, becomes attractive for fabricating biocompatible flexible functional devices but is plagued by hydrophilic properties, which make it easily break down in water by poor mechanical stability. Here we report a class of SiO2-nanoparticle-decorated bacteria-cellulose meta-skin with superior stability in water, excellent machining property, ultrathin thickness, and active bacteria-repairing capacity. We further develop functional ultrasonic metasurfaces based on meta-skin paper-cutting that can generate intricate patterns of ~10 µm precision. Benefited from the perfect ultrasound insulation of surface Cassie-Baxter states, we utilize meta-skin paper-cutting to design and fabricate ultrathin (~20 µm) and super-light (<20 mg) chip-scale devices, such as nonlocal holographic meta-lens and the 3D imaging meta-lens, realizing complicated acoustic holograms and high-resolution 3D ultrasound imaging in far fields. The decorated bacteria-cellulose ultrasonic metasurface opens the way for exploiting flexible and biologically degradable metamaterial devices with functionality customization and key applications in advanced biomedical engineering technologies.