Hierarchical MOFs with Good Catalytic Properties and Structural Stability in Oxygen-Rich and High-Temperature Environments.

Metal-organic framework materials are ideal materials characterized by open frameworks, adjustable components, and high catalytic activity. They are extensively utilized for catalysis. Due to decomposition and structural collapse under high temperatures and an oxygen-rich environment, the potential of thermal catalysis is greatly limited. In this research, Co-rich hollow spheres (Co-HSs) with a gradient composition are designed and synthesized to investigate their thermal catalytic properties in the ammonium perchlorate（AP）system. The results demonstrate that Co-HSs@AP exhibits good thermal catalytic activity and a high-temperature decomposition of 292.5 °C, which is 121.6 °C lower than pure AP. The hierarchical structure confers structural stability during the thermal decomposition process. Thermogravimetry-infrared indicates that the inclusion of Co-HSs successfully boosts the level of reactive oxygen species and achieves thorough oxidation of NH3. Based on the above phenomenon, macro dynamics calculations are carried out. The results show that Co-HSs can promote the circulation of lattice oxygen and reactive oxygen species and the multidimensional diffusion of NH3 in an oxygen-rich environment. This material has significant potential for application in the fields of thermal catalysis and ammonia oxidation.

In vivo therapy of osteosarcoma using anion transporters-based supramolecular drugs.

BACKGROUND: Osteosarcoma represents a serious clinical challenge due to its widespread genomic alterations, tendency for drug resistance and distant metastasis. New treatment methods are urgently needed to address those treatment difficulties in osteosarcoma to improve patient prognoses. In recent years, small-molecule based anion transporter have emerged as innovative and promising therapeutic compound with various biomedical applications. However, due to a lack of efficient delivery methods, using ion transporters as therapeutic drugs in vivo remains a major challenge. RESULT: Herein, we developed self-assembled supramolecular drugs based on small-molecule anion transporters, which exhibited potent therapeutic effect towards osteosarcoma both in vitro and in vivo. The anion transporters can disrupt intracellular ion homeostasis, inhibit proliferation, migration, epithelial-mesenchymal transition process, and lead to osteosarcoma cell death. RNA sequencing, western blot and flow cytometry indicated reprogramming of HOS cells and induced cell death through multiple pathways. These pathways included activation of endoplasmic reticulum stress, autophagy, apoptosis and cell cycle arrest, which avoided the development of drug resistance in osteosarcoma cells. Functionalized with osteosarcoma targeting peptide, the assembled supramolecular drug showed excellent targeted anticancer therapy against subcutaneous xenograft tumor and lung metastasis models. Besides good tumor targeting capability and anti-drug resistance, the efficacy of the assembly was also attributed to its ability to regulate the tumor immune microenvironment in vivo. CONCLUSIONS: In summary, we have demonstrated for the first time that small-molecule anion transporters are capable of killing osteosarcoma cells through multiple pathways. The assemblies, OTP-BP-L, show excellent targeting and therapeutic effect towards osteosarcoma tumors. Furthermore, the supramolecular drug shows a strong ability to regulate the tumor immune microenvironment in vivo. This work not only demonstrated the biomedical value of small-molecule anion transporters in vivo, but also provided an innovative approach for the treatment of osteosarcoma.

A Pure Shift-Based Nuclear Magnetic Resonance Method for In-Phase Three-Dimensional Diffusion-Ordered Spectroscopy.

Diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY) plays a vital role in mixture studies. However, its applications to complex mixture samples are generally limited by spectral congestion along the chemical shift domain caused by extensive J coupling networks and abundant compounds. Herein, we develop the in-phase multidimensional DOSY strategy for complex mixture analyses by simultaneously revealing molecular self-diffusion behaviors and multiplet structures with optimal spectral resolution. As a proof of concept, two pure shift-based three-dimensional (3D) DOSY protocols are proposed to record high-resolution 3D spectroscopic view with separated mixture components and their resolved multiplet coupling structures, thus suitable for analyzing complex mixtures that contain abundant compounds and complicated molecular structures, even under adverse magnetic field conditions. Therefore, this study shows a promising tool for component analyses and multiplet structure studies on practical mixture samples.

Oriented Assembled Prussian Blue Analogue Framework for Confined Catalytic Decomposition of Ammonium Perchlorate.

The design of highly dispersed active sites of hollow materials and unique contact behavior with the components to be catalyzed provide infinite possibilities for exploring the limits of catalyst capacity. In this study, the synthesis strategy of highly open 3-dimensional frame structure Prussian blue analogues (CoFe-PBA) was explored through structure self-transformation, which was jointly guided by template mediated epitaxial growth, restricted assembly and directional assembly. Additionally, good application prospect of CoFe-PBA as combustion catalyst was discussed. The results show that unexpected thermal decomposition behavior can be achieved by limiting AP(ammonium perchlorate) to the framework of CoFe-PBA. The high temperature decomposition stage of AP can be advanced to 283.6 °C and the weight loss rate can reach 390.03% min-1 . In-situ monitoring shows that CoFe-PBA can accelerate the formation of NO and NO2 . The calculation of reaction kinetics proved that catalytic process was realized by increasing the nucleation factor. On this basis, the catalytic mechanism of CoFe-PBA on the thermal decomposition of AP was discussed, and the possible interaction process between AP and CoFe-PBA during heating was proposed. At the same time, another interesting functional behavior to prevent AP from caking was discussed.

Efficient targeted learning of heterogeneous treatment effects for multiple subgroups.

In biomedical science, analyzing treatment effect heterogeneity plays an essential role in assisting personalized medicine. The main goals of analyzing treatment effect heterogeneity include estimating treatment effects in clinically relevant subgroups and predicting whether a patient subpopulation might benefit from a particular treatment. Conventional approaches often evaluate the subgroup treatment effects via parametric modeling and can thus be susceptible to model mis-specifications. In this paper, we take a model-free semiparametric perspective and aim to efficiently evaluate the heterogeneous treatment effects of multiple subgroups simultaneously under the one-step targeted maximum-likelihood estimation (TMLE) framework. When the number of subgroups is large, we further expand this path of research by looking at a variation of the one-step TMLE that is robust to the presence of small estimated propensity scores in finite samples. From our simulations, our method demonstrates substantial finite sample improvements compared to conventional methods. In a case study, our method unveils the potential treatment effect heterogeneity of rs12916-T allele (a proxy for statin usage) in decreasing Alzheimer's disease risk.

The experimental approach for the interleaved joint modulation of PHIP and NMR.

Nuclear spin hyperpolarization derived from parahydrogen is a technique for enhancing nuclear magnetic resonance (NMR) sensitivity. The key to hyperpolarization experiments is to achieve rapid transfer and detection to minimize relaxation losses, while also avoiding bubbles or turbulence to guarantee high spectral resolution. In this article, we describe an experimental approach for the interleaved joint modulation of parahydrogen-induced polarization and NMR. We provide schematic diagrams of parahydrogen-based polarizer with in situ high-pressure detection capability and low-field polarization transfer. This approach can help to control the experimental process and acquire experimental information, one example of which is the attainment of the highest hyperpolarization signal intensity at 3.6 s after closing the valve. The polarizer demonstrates in situ detection capability, allowing sample to be restabilized within 0.3 ± 0.1 s and high-resolution NMR sampling under a pressure of 3 bars. Moreover, it can transfer polarized samples from the polarization transfer field to the detection region of NMR within 1 ± 0.3 s for completing signal amplification by reversible exchange experiments.

Genomic divergence of Stellera chamaejasme through local selection across the Qinghai-Tibet plateau and northern China.

Understanding how populations diverge and new species arise is a central question in evolutionary biology. "Allopatric" divergence through geographical isolation is considered to be the commonest mechanism generating species biodiversity in mountain ecosystems. However, the underlying genomic dynamics, especially genomic islands of elevated divergence and genes that are highly diverged as a result of lineage-specific selection, remain poorly understood. Stellera chamaejasme has a wide geographical range across the Qinghai-Tibet Plateau and northern China, making it a good model with which to explore genomic divergence during speciation in mountain ecosystems. We assembled a high-quality, chromosome-level genome for this species and resequenced the genomes of 24 populations across its major distribution. Our population genomic analyses recovered four distinct genetic lineages corresponding to geographical distributions with contrasting environments. However, we revealed continuous gene flow during the historical divergences of these four lineages. Interlineage hybrids and plastome introgressions were frequently found in regions of contact, which further increased gene flow between two contacting lineages in the recent past. The elevated divergences were highly heterogeneous across the genome and selection of ancestral polymorphisims and divergence hitchhiking contributed greatly to the formation of genomic islands. The highly diverged and lineage-specific positively selected genes within and outside genomic islands were annotated to be mainly involved in local adaptation. Our results suggest that genomic divergence in S. chamaejasme is likely to have been triggered and maintained by local selection together with geographical isolation.

Exosomal lncRNA HOTAIR induce macrophages to M2 polarization via PI3K/ p-AKT /AKT pathway and promote EMT and metastasis in laryngeal squamous cell carcinoma.

Exosomes are a new way of the communication between the tumor cell and macrophage in the micro-environment. The macrophage can be induced to different phenotypes according to the different tumors. In the present study, long-chain noncoding RNA HOTAIR (lncRNA HOTAIR) was highly expressed in LSCC and exosomes. The pathway of exosomal lncRNA HOTAIR inducing macrophage to M2 polarization in the LSCC was investigated. The carcinoma tissues and adjacent tissues were collected from 104 LSCC cases, and the positive relationship between CD163-/CD206-M2 macrophage infiltration and clinical phase, lymph node spreading and pathological phase in LSCC was observed. To examine the role of exosomal lncRNA HOTAIR, macrophages were co-cultured with LSCC-exosomes of high lncRNA HOTAIR expression or transferred with HOTAIR mimics. It was suggested that exosomal lncRNA HOTAIR can induce macrophages to M2 polarization by PI3K/p-AKT/AKT signaling pathway. Furthermore, exo-treated M2 macrophages facilitate the migration, proliferation, and EMT of LSCC.

IVIM using convolutional neural networks predicts microvascular invasion in HCC.

OBJECTIVES: The study aimed to investigate the diagnostic performance of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) using convolutional neural networks (CNNs). METHODS: This retrospective study included 114 patients with pathologically confirmed HCC from December 2014 to August 2021. All patients underwent MRI examination including IVIM sequence with 9 b-values preoperatively. First, 9 b-value images were superimposed in the channel dimension, and a b-value volume with a shape of 32 × 32 × 9 dimension was obtained. Secondly, an image resampling method was performed for data augmentation to generate more samples for training. Finally, deep features to predict MVI in HCC were directly derived from a b-value volume based on the CNN. Moreover, a deep learning model based on parameter maps and a fusion model combined with deep features of IVIM, clinical characteristics, and IVIM parameters were also constructed. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performance for MVI prediction in HCC. RESULTS: Deep features directly extracted from IVIM-DWI (0.810 (range 0.760, 0.829)) using CNN yielded better performance for prediction of MVI than those from IVIM parameter maps (0.590 (range 0.555, 0.643)). Furthermore, the performance of the fusion model combined with deep features of IVIM-DWI, clinical features (α-fetoprotein (AFP) level and tumor size), and apparent diffusion coefficient (ADC) (0.829 (range 0.776, 0.848)) was slightly improved. CONCLUSIONS: Deep learning with CNN based on IVIM-DWI can be conducive to preoperative prediction of MVI in patients with HCC. KEY POINTS: • Deep learning assessment of IVIM data for prediction of MVI in HCC can overcome the unstable and low performance of IVIM parameters. • Deep learning model based on IVIM performs better than parameter values, clinical features, and deep learning model based on parameter maps. • The fusion model combined with deep features of IVIM, clinical characteristics, and ADC yields better performance for prediction of MVI than the model only based on IVIM.

Osteal Tissue Macrophages Are Involved in Endplate Osteosclerosis through the OSM-STAT3/YAP1 Signaling Axis in Modic Changes.

Modic changes (MCs) are radiographic manifestations of lumbar degenerative diseases. Various types of MCs are often associated with endplate osteosclerosis. Osteal tissue macrophages (Osteomacs) were reported to be crucial for bone homeostasis and bone repair, but whether osteomacs participate in the endplate osteosclerosis in MCs remained unclear. In this study, we tried to explore the critical role of osteomacs in regulating osteogenesis in MCs. We collected MCs from patient samples and developed a Propionibacterium acnes-induced rat MCs model, using microcomputed tomography and immunohistochemistry to detect the endplate bone mass and distribution of osteomacs. In patients' MCs, osteomacs increased in endplate subchondral bone, especially in Modic type II. Endplate in Modic type III presented a stable osteosclerosis. In rat MCs model, osteomacs increased in the bone hyperplasia area but not in the inflammation area of the endplate region, whereas the distribution of osteomacs was consistent with the area of osteosclerosis. To further explore the functions of osteomacs in vitro, we isolated osteomacs using MACS technology and found osteomacs secreted oncostatin M (OSM) and strongly promoted osteoblast differentiation rather than osteoclast through the mechanism of OSM-mediated tyrosine phosphorylation and interaction of STAT3 and Yes-associated protein 1 (YAP1). STAT3 phosphorylation inhibition or YAP1 knockdown attenuated OSM-mediated osteoblast differentiation. Finally, we confirmed that blockade of OSM in vivo using anti-OSM-neutralizing Ab prevented endplate osteosclerosis in rat MCs model. Taken together, these findings confirmed that endplate osteosclerosis in MCs was accompanied by an increased number of osteomacs, which regulated osteogenesis via the OSM-STAT3/YAP1 signaling axis.

Methyl 3,4-dihydroxybenzoate inhibits RANKL-induced osteoclastogenesis via Nrf2 signaling in vitro and suppresses LPS-induced osteolysis and ovariectomy-induced osteoporosis in vivo.

Osteoporosis deteriorates bone mass and biomechanical strength and is life-threatening to the elderly. In this study, we show that methyl 3,4-dihydroxybenzoate (MDHB), an antioxidant small-molecule compound extracted from natural plants, inhibits receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis in vitro. Furthermore, MDHB attenuates the activation of mitogen-activated protein kinase (MAPK) and NF-κB pathways by reducing the levels of reactive oxygen species (ROS), which leads to downregulated protein expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1). We also confirm that MDHB upregulates the protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), an important transcription factor involved in ROS regulation, by inhibiting the ubiquitination-mediated proteasomal degradation of Nrf2. Next, animal experiments show that MDHB has an effective therapeutic effect on lipopolysaccharide (LPS)- and ovariectomized (OVX)-induced bone loss in mice. Our study demonstrates that MDHB can upregulate Nrf2 and suppress excessive osteoclast activity in mice to treat osteoporosis.

Evolutionary origin of a tetraploid Allium species on the Qinghai-Tibet Plateau.

Extinct taxa may be detectable if they were ancestors to extant hybrid species, which retain their genetic signature. In this study, we combined phylogenomics, population genetics and fluorescence in situ hybridization (GISH and FISH) analyses to trace the origin of the alpine tetraploid Allium tetraploideum (2n = 4x = 32), one of the five known members in the subgenus Cyathophora. We found that A. tetraploideum was an obvious allotetrapoploid derived from ancestors including at least two closely related diploid species, A. farreri and A. cyathophorum, from which it differs by multiple ecological and genomic attributes. However, these two species cannot account for the full genome of A. tetraploideum, indicating that at least one extinct diploid is also involved in its ancestry. Furthermore, A. tetraploideum appears to have arisen via homoploid hybrid speciation (HHS) from two extinct allotetraploid parents, which derived in turn from the aforementioned diploids. Other modes of origin were possible, but all were even more complex and involved additional extinct ancestors. Our study together highlights how some polyploid species might have very complex origins, involving both HHS and polyploid speciation and also extinct ancestors.

Protein complex identification based on weighted PPI network with multi-source information.

Proteins form complexes to accomplish biological functions such as transcription of DNA, translation of mRNA and cell growth. Detection of protein complexes from protein-protein interaction (PPI) networks is the first step for the analysis of biological processes and pathways. Here, we propose a new framework by incorporating Gene Ontology (GO), amino acid background frequency (AABF) and data from von Mering (von Mering data) to identify protein complexes. Firstly, based on the semantic similarity of GO, we construct a weighted PPI network. Secondly, von Mering data is added to construct six types of weighted graphs. Lastly, by integrating density, diameter and cosine similarity, we define a new condition for clustering proteins in these weighted protein network by selecting specific node as key node. Comparison and analysis results indicate that our proposed method could achieve better performances than some classic existing approaches in regard to f-measure and precision.

Combining sequence and Gene Ontology for protein module detection in the Weighted Network.

Studies of protein modules in a Protein-Protein Interaction (PPI) network contribute greatly to the understanding of biological mechanisms. With the development of computing science, computational approaches have played an important role in locating protein modules. In this paper, a new approach combining Gene Ontology and amino acid background frequency is introduced to detect the protein modules in the weighted PPI networks. The proposed approach mainly consists of three parts: the feature extraction, the weighted graph construction and the protein complex detection. Firstly, the topology-sequence information is utilized to present the feature of protein complex. Secondly, six types of the weighed graph are constructed by combining PPI network and Gene Ontology information. Lastly, protein complex algorithm is applied to the weighted graph, which locates the clusters based on three conditions, including density, network diameter and the included angle cosine. Experiments have been conducted on two protein complex benchmark sets for yeast and the results show that the approach is more effective compared to five typical algorithms with the performance of f-measure and precision. The combination of protein interaction network with sequence and gene ontology data is helpful to improve the performance and provide a optional method for protein module detection.

The impact of environmental accidents on the green apparel purchase behavior of Generation Z.

Introduction: This study examines the impact of environmental accidents on Generation Z's purchase behavior towards green apparel, integrating the Theory of Planned Behavior and the Norm Activation Theory to conceptualize how different dimensions of environmental accidents influence consumer behavior. Methods: Employing focus groups and questionnaires, this research captures data on Generation Z's perceptions and behaviors towards green apparel in the context of environmental accidents. The collected data were analyzed using SPSS software, with structural equation modeling employed to test the research hypotheses. Results: The findings indicate that the scale (H12 = 0.545), the degree of suddenness (H18 = 0.357), nature of the effect (H14 = 0.295), and duration (H17 = 0.289) of environmental accidents significantly influence Generation Z's awareness of consequences, behavioral attitudes, subjective norms, and perceived behavioral control regarding the purchase of green clothing. Notably, the scale of environmental accidents has a significant impact on perceived behavioral control, which in turn significantly affects Generation Z's intention to purchase green apparel (H3 = 0.5). Discussion: This study elucidates the impact of environmental accidents on Generation Z's green apparel purchase intentions. The findings highlight Generation Z's environmental awareness and social responsibility, influencing their purchasing decisions. This research offers practical insights for brands to enhance green marketing strategies, focusing on product quality, transparency, and consumer education to align with Generation Z's values and expectations. Future research should explore additional factors affecting purchase behavior and strategies to bridge the intention-behavior gap.

Investigation on Creep Deformation and Age Strengthening Behavior of 304 Stainless Steel under High Stress Levels.

The creep deformation behavior and age strengthening behavior of 304 stainless steel under high stress levels were systematically studied by uniaxial creep test, tensile test, XRD diffraction test and transmission electron microscopy. The results show that the total creep strain and the initial creep strain rate increase with the increase in stress level, and the creep strain in the whole aging process is mainly produced in the initial creep stage. The calculated stress exponent shows that the main mechanism of creep deformation of 304 stainless steel at 453 K is dislocation slip. The strength and plasticity of 304 stainless steel after creep aging are improved simultaneously. Microstructural observations indicate an increase in dislocation density and martensite content, as well as austenite and twins, leading to an improvement in strength and plasticity, respectively. In addition, considering the influence of dislocation density on creep behavior, the relative dislocation density increase is introduced into the hyperbolic sine creep model, and a simple mechanism-based creep aging constitutive model is established. The creep strain predicted by the model is in good agreement with the experimental data of 304 stainless steel. The findings can provide theoretical support for the application of creep age forming in 304 stainless steel parts.

Efficacy and safety of ultrasound-assisted wound debridement in the treatment of diabetic foot ulcers: a systematic review and meta-analysis of 11 randomized controlled trials.

Objective: Research data suggests that ultrasound-assisted wound debridement (UAWD) can effectively promote the healing of diabetic foot ulcers (DFU). However, existing research is not consistent with this viewpoint. Therefore, we conducted this study to investigate the effect of UAWD on the healing of diabetic foot ulcers. Methods: From the establishment of the database to January 2024, we searched 8 databases to study the effectiveness and safety of UAWD in the treatment of DFU. Two authors independently screened the qualifications of the articles, while two authors extracted relevant data. Statistical analysis was conducted using Review Manager 5.4 and STATA 18.0 software. Results: A total of 11 randomized controlled studies were included, with 6 countries and 696 participants participating. Our findings showed that UAWD was associated with a significant benefit in healing rate (OR = 2.60, 95% CI: [1.67, 4.03], P < 0.0001, I2 = 25%), wound healing time (MD = -11.94, 95% CI: [-23.65, -0.23], P = 0.05, I2 = 99%), percentage reduction in wound size (MD = 14.2, 95% CI: [10.8, 17.6], P = 0.47, I2 = 32%), effectiveness of treatment (OR = 10.3, 95% CI: [4.68, 22.66], P < 0.00001, I2 = 0%). Moreover, UAWD did not cause any significant adverse reactions. However, there was no obvious difference in wound blood perfusion (MD = 0.25, 95% CI: [-0.01, 0.52], P = 0.06, I2 = 90%), transcutaneous oxygen partial pressure (MD = 14.34, 95% CI: [-10.03, 38.71], P = 0.25, I2 = 98%). Conclusion: UAWD can significantly improve wound healing rate, shorten wound healing time, accelerate wound area reduction, and improve clinical treatment effectiveness without significant adverse reactions. Although there is no significant difference in transcutaneous oxygen pressure and wound blood flow perfusion between UAWD and SWC. So we look forward to more scientifically blinded, placebo-controlled, high-quality studies in the future, to enable researchers to obtain more complete and accurate analytical data, in order to improve the scientific and credibility of the evidence. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42024501198.

A sequence-aware merger of genomic structural variations at population scale.

Merging structural variations (SVs) at the population level presents a significant challenge, yet it is essential for conducting comprehensive genotypic analyses, especially in the era of pangenomics. Here, we introduce PanPop, a tool that utilizes an advanced sequence-aware SV merging algorithm to efficiently merge SVs of various types. We demonstrate that PanPop can merge and optimize the majority of multiallelic SVs into informative biallelic variants. We show its superior precision and lower rates of missing data compared to alternative software solutions. Our approach not only enables the filtering of SVs by leveraging multiple SV callers for enhanced accuracy but also facilitates the accurate merging of large-scale population SVs. These capabilities of PanPop will help to accelerate future SV-related studies.

Mrgprb2-mediated mast cell activation exacerbates Modic changes by regulating immune niches.

Modic changes are radiographic features associated with microfracture, low-virulence organism infection and chronic inflammation with inflammatory cell infiltration in the vertebral endplate region. Mast cells, as innate immune cells similar to macrophages, are present in painful degenerated intervertebral discs. However, the involvement and mechanisms of mast cells in the development of Modic changes remain unclear. Herein, we found increased mast cell infiltration in samples from patients with Modic changes and in mouse models of Modic changes. To clarify the role of mast cells in the progression of Modic changes, we used mast cell-deficient (KITW-SH/W-SH) mice to construct a model of Modic changes and found that the severity of Modic changes in KITW-SH/W-SH mice was significantly lower than that in WT mice. These findings were further supported by the use of a mast cell-specific activator (compound 48/80) and a stabilizer (cromolyn). Furthermore, we found that mast cells were not activated via the classic IgE pathway in the Modic change models and that Mrgprb2 is the specific receptor for mast cell activation reported in recent studies. Then, we utilized Mrgprb2 knockout mice to demonstrate that Mrgprb2 knockout inhibited mast cell activation and thus reduced the degree of Modic changes. Transcriptomic sequencing revealed aberrant PI3K-AKT and MAPK pathway activation in the Mrgprb2-deficient mast cells. Additionally, Mrgpbrb2-activated mast cells regulate immune niches by recruiting macrophages, promoting M1 polarization and reducing M2 polarization, thereby promoting the progression of Modic changes. These findings suggest that mast cells may serve as a novel therapeutic target for addressing Modic changes.

Band 40/41 Surface Acoustic Wave Filters on 42°YX-Lithium Tantalate Substrate with Suppression of Transverse Leakage.

The transverse leakage of leaky surface acoustic waves (LSAWs) occurs on 42°YX-lithium tantalate substrates (42LT), which increases the insertion loss, narrows the bandwidth and flattens the roll-off of band 40/41 SAW filters and duplexers. In this work, LSAW characteristics with different metal materials and thicknesses are calculated by the finite element method (FEM), which determines the IDT material and thickness used for band 40/41 SAW filter design. To deeply understand transverse leakage and suppress it, the effects of different gap and dummy lengths on transverse leakage are simulated and discussed. Then, a new technique of using a wider dummy without any additional lithographic or depositing processes is proposed to suppress the leakage. Its effectiveness is validated by both simulations and experiments. Then, the technique is extended to applications of band 40 and 41 SAW filters. The experimental results show that with the wider dummy structure, the band 40 and 41 SAW filters achieve a more than 0.2 dB improvement in the insertion loss, a wider bandwidth and a steeper roll-off characteristic. This technique may also be extended to the other band SAW filter applications.