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SnTe, as one type of topological crystal insulator (TCI), has crystal-symmetry-protected surface states, which is sensitive to its structure and lattice symmetry. Herein, the monolayer SnTe was well synthesized, presenting with tetragonal and hexagonal lattice symmetries, respectively. The lattice symmetry was found to be connected with precursors, as thermal evaporation of SnTe compounds led to a tetragonal type symmetry while co-deposition of Sn and Te elements can synthetize the hexagonal type. As a consequence of lattice mismatch with the underlying Au(111) substrate, SnTe with tetragonal lattice exhibits reconstructive stripe pattern, which would transform into hexagonal lattice symmetry with moiré pattern upon annealing at high temperature. Due to coupling with the substrate, SnTe exhibits metallicity in both symmetries, verified by corresponding differential conductance spectra (dI/dV). Comparative study on Cu(111) substrate was carried out and only copper telluride structures were formed, which may be related to the stronger surface decomposition of SnTe precursors on Cu(111) and direct copper tellurizing. Our work paves a practical way to control the surface structure and lattice symmetry of SnTe, providing a promising candidate for potential TCI applications. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) chromium selenide with different stoichiometries have attracted considerable interest because of their exotic electronic and magnetic properties. Herein, the monolayer CrSe2 on the Au(111) substrate was synthesized by molecular beam epitaxy and annealed to form monolayer Cr2Se3, which was revealed by the scanning tunneling microscopy. Moiré superstructure in CrSe2/Au(111) was observed with a twist angle of ∼1.5°, and the stacking position-dependent p-type semiconducting characteristic of CrSe2 on Au(111) was recorded by scanning tunneling spectroscopy. Due to the annealing induced strong interfacial interaction, structural and electronic properties transited from CrSe2 to Cr2Se3, with the latter exhibiting metallic feature. Correspondingly, the original Se8 molecules surrounding CrSe2 assembled into 3 × 3 R30°-Se/Au reconstruction, which further verified the structural transition. Our work provides a basis for fundamental study of stoichiometric-dependent physics and potential applications in data storage devices. [ABSTRACT FROM AUTHOR]

Immunogenic cell death (ICD) induced by calcium ion (Ca2+) overload has attracted significant attention owing to its ability to activate the immune system and generate durable antitumor immune responses. However, the slow release of Ca2+ by commonly used nanomodulators provides tumor cells with the opportunity to efficiently eliminate excess Ca2+ through ion channels, thus diminishing the therapeutic efficacy. Consequently, it is crucial to explore strategies for rapid Ca2+ release. To address this issue, a glutathione‐triggered Ca(IO3)2@starch‐based Ca2+ nanobomb is presented. This nanobomb not only enables accurate and efficient Ca2+ delivery to the tumor site but also exploits glutathione‐triggered photoacoustic (PA) imaging‐guided photothermal precise control of TRPV1 ion channel activation for enhancing the Ca2+ influx. Both in vitro and in vivo results confirm that the photothermally regulated Ca2+ influx based on this Ca2+ nanobomb effectively promotes ICD and stimulates immune infiltration in tumor tissues, ultimately leading to the effective inhibition of tumor growth and metastasis. The developed Ca2+ nanobomb presents a potential strategy to enhance ICD based on Ca2+ overload, thus addressing the challenges associated with precise and timely regulation of Ca2+ influx and offering prospects for improved antitumor immunotherapy. [ABSTRACT FROM AUTHOR]

Pancreatic cancer, a prevalent malignancy of the digestive system, has a poor 5‐year survival rate of around 10%. Although numerous minimally invasive alternative treatments, including photothermal therapy and photodynamic therapy, have shown effectiveness compared with traditional surgical procedures, radiotherapy, and chemotherapy. However, the application of these alternative treatments is constrained by their depth of penetration, making it challenging to treat pancreatic cancer situated deep within the tissue. Sonodynamic therapy (SDT) has emerged as a promising minimally invasive therapy method that is particularly potent against deep‐seated tumors such as pancreatic cancer. However, the unique characteristics of pancreatic cancer, including a dense surrounding matrix, high reductivity, and a hypoxic tumor microenvironment, impede the efficient application of SDT. Thus, to guide the evolution of SDT for pancreatic cancer therapy, this review addresses these challenges, examines current strategies for effective SDT enhancement for pancreatic cancer, and investigates potential future advances to boost clinical applicability. This article is categorized under:Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease [ABSTRACT FROM AUTHOR]

Copper sulfide based phototherapy, including photothermal therapy and photodynamic therapy, is an emerging minimally invasive treatment of tumor, which the light was converted to heat or reactive oxygen to kill the tumor cells. Compared with conventional chemotherapy and radiation therapy, Cu2−xS based phototherapy is more efficient and has fewer side effects. However, considering the dose‐dependent toxicity of Cu2−xS, the performance of Cu2−xS based phototherapy still cannot meet the requirement of the clinical application to now. To overcome this limitation, engineering of Cu2−xS to improve the phototherapy performance by increasing light absorption has attracted extensive attention. For better guidance of Cu2−xS engineering, we outline the currently engineering method being explored, including (1) structural engineering, (2) compositional engineering, (3) functional engineering, and (4) performance engineering. Also, the relationship between the engineering method and phototherapy performance was discussed in this review. In addition, the further development of Cu2−xS based phototherapy is prospected, including smart materials based phototherapy, phototherapy induced immune microenvironment modulation et al. This review will provide new ideas and opportunities for engineering of Cu2−xS with better phototherapy performance. This article is categorized under:Diagnostic Tools > In Vivo Nanodiagnostics and ImagingTherapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease [ABSTRACT FROM AUTHOR]

The dynamic characteristics of long-span suspension bridges are complex. The natural vibration frequency is changed with different structural parameters, and the sensitivity to different parameters is different. In order to solve this problem, the spatial model of a long-span suspension bridge was established by using finite element software, and the first 20 natural vibration periods, natural vibration frequencies and vibration modes were analyzed and calculated. The accuracy of the obtained natural vibration frequency data was verified through field tests. Finally, based on the model, the stiffness of structural components is studied by one -factor-at-one-time, and the influence of various variables on the frequency and mode of a certain mode is studied by one-factor-at-one-time method. The results show that different structural parameters have different effects on the vibration frequency. When the stiffness of stiffening girder and main tower is changed, with the increase of stiffness, the variation of frequency mostly presents an upward trend, and the range is large. With the change of the secondary dead load, most of the frequencies decrease first and then tend to be stable. It can be seen from the field test results that the vibration shapes and frequencies measured by numerical simulation and test are close to each other, which can meet the requirements of engineering precision. The stiffness of the main cable and the main tower has a great influence on the modes and periods corresponding to them. The increase of the secondary dead load can reduce the natural vibration frequency of the suspension bridge, but it is not unlimited to increase the secondary dead load to reduce the frequency. The stiffness of the stiffening girder has a great influence on the frequency of the suspension bridge. When the bending stiffness of the stiffening girder increases to 3 times of the original one, the order of vibration modes of the structure will change. The research results can provide references for structural design and dynamic parameter adjustment of long-span suspension bridge.