Topological Wannier cycles for the bulk and edges

Topological materials are often characterized by unique edge states which are in turn used to detect different topological phases in experiments. Recently, with the discovery of various higher-order topological insulators, such spectral topological characteristics are extended from edge states to corner states. However, the chiral symmetry protecting the corner states is often broken in genuine materials, leading to vulnerable corner states even when the higher-order topological numbers remain quantized and invariant. Here, we show that a local artificial gauge flux can serve as a robust probe of the Wannier type higher-order topological insulators which is effective even when the chiral symmetry is broken. The resultant observable signature is the emergence of the cyclic spectral flows traversing one or multiple band gaps. These spectral flows are associated with the local modes bound to the artificial gauge flux. This phenomenon is essentially due to the cyclic transformation of the Wannier orbitals when the local gauge flux acts on them. We extend topological Wannier cycles to systems with C2 and C3 symmetries and show that they can probe both the bulk and the edge Wannier centers, yielding rich topological phenomena

Effect of fucoidan on B16 murine melanoma cell melanin formation and apoptosis

Background：Fucoidan is a complex sulfated polysaccharide extracted from brown seaweed and has a wide variety of biological activities. It not only inhibits cancer cell growth but also inhibits tyrosinase in vitro. Therefore, it is of interest to investigate the effect of fucoidan on B16 murine melanoma cells as the findings may provide new insights into the underlying mechanism regarding the inhibition of melanin formation by fucoidan. In the present study, we aimed to investigate the anti-melanogenic effect of fucoidan and its inhibitory effect on B16 cells.Materials and Methods: The influence of fucoidan on B16 melanoma cells and cellular tyrosinase was examined. Cell viability was examined by the cell counting kit-8 assay. Cellular tyrosinase activity and melanin content were determined using spectrophotometric methods and protein expression was analyzed by immunoblotting. Morphological changes in B16 melanoma cells were examined by phase contrast microscopy and apoptosis was analyzed by flow cytometry.Results: In vitro studies were performed using cell viability analysis and showed that fucoidan significantly decreased viable cell number in a dose-response manner with an IC50 of 550 ±4.3 μg/mL. Cell morphology was altered and significant apoptosis was induced when cells were exposed to 550 μg/mL fucoidan for 48 h.Conclusion: This study provides substantial evidence to show that fucoidan inhibits B16 melanoma cell proliferation and cellular tyrosinase activity. Fucoidan may be useful in the treatment of hyperpigmentation and as a skin-whitening agent in the cosmetics industry.Keywords: B16 melanoma cells, Fucoidan, Melanogenesis, Tyrosinas

Observation of a phononic higher-order Weyl semimetal

Weyl semimetals are extraordinary systems where exotic phenomena such as Fermi arcs, pseudo-gauge fields and quantum anomalies arise from topological band degeneracy in crystalline solids for electrons and metamaterials for photons and phonons. On the other hand, higher-order topological insulators unveil intriguing multidimensional topological physics beyond the conventional bulk-edge correspondences. However, it is unclear whether higher-order topology can emerge in Weyl semimetals. Here, we report the experimental discovery of higher-order Weyl semimetals in its phononic analog which exhibit topologically-protected boundary states in multiple dimensions. We create the physical realization of the higher-order Weyl semimetal in a chiral phononic crystal with uniaxial screw symmetry. Using near-field spectroscopies, we observe the chiral Fermi arcs on the surfaces and a new type of hinge arc states on the hinge boundaries. These topological boundary arc states link the projections of Weyl points in different dimensions and directions, and hence demonstrate higher-order multidimensional topological physics in Weyl semimetals. Our study establishes the fundamental connection between higher-order topology and Weyl physics in crystalline materials and unveils a new horizon of higher-order topological semimetals where unprecedented materials such as higher-order topological nodal-lines may emerge

On the definition of noise

Urbanization has exposed people to extreme sound levels. Although researchers have investigated the ability of people to listen, analyze, and distinguish sound, the concept of noise has not been clearly articulated from a human perspective. The lack of knowledge on how people perceive noise limits our capacity to control it in a targeted manner. This study aimed to interpret the definition of noise from the public perspective based on a grounded theory approach. Seventy-eight participants were interviewed about noise, and four categories of perceived understanding of noise were identified: challenges, definitions of noise, opportunities, and action. As one of the challenges, urbanization is associated with increased noise levels around the human environment. In terms of definition, perceiving sound as noise is considered to be a result of the complex and dynamic process that includes sound, the environment, and humans. Sound and humans interact with the environment. In terms of opportunities, noise may have positive roles on certain occasions, dispelling the misconception that noise is exclusively negative. In addition, we found that noise perception has gradually shifted from noise control to noise utilization. In terms of action, noise can be controlled at the sound sources, susceptible target groups, susceptible behaviors and states, locations, and times where noise is perceived with high frequency. In this study, we investigated several aspects of noise, ranging from noise control, soundscape definition, and ‘soundscape indices’ (SSID) integration and application. Our findings provide an additional basis for developing better definitions, control, and utilization strategies of noise in the future, thereby improving the quality of the sound environment

贴片式动态心电记录仪在临床教学中可行性研究

Objective: To explore effectiveness of clinical application of the patch type dynamic ecg recorder by comparing with conventional dynamic ecg recorder Holter. And the clinical ecg teaching models is discussed in this paper. Methods: Using parallel controlled trial method, 60 patients in two hospitals received Holter examination, and patch heart testing at the same time. A comparative analysis of two kinds of inspection methods on testing the average heart rate, supraventricular premature beats and ventricular premature beat was made. Results: The average heart rate of patch type ECG and Holter were 71.87±9.28 and 72.55±9.06 (P = 0.0879). Two kinds of detection methods, chamber on the coincidence rate of premature beat (PPS) was 98.33%, 95% CI (91.06, 99.96), Kappa = 0.9462, 95% CI (0.84, 1.00), good consistency. The accuracy of ventricular premature beat (PPS) was 98.33%, 95% CI (91.06, 99.63), Kappa = 0.9850, 95% CI (0.90, 1.00), good consistency. Patch type heart all platform is suitable for self-study and clinical care study, and professional skill assessment,etc.Conclusion: The effectiveness of patch type heart all on testing the average heart rate, supraventricular premature beat is the same as Holter. it is also suitable for to carry out clinical ECG teaching at the same time.目的 通过和常规动态心电记录仪 Holter比较，研究贴片式的动态心电记录仪临床应用的有效性。并探讨其在临床心电教学中的模式。方法 采用自身平行对照试验方法，在两医院60例患者用Holter检查时，同时用贴片心电仪检测，比较分析两种检查方法在检测平均心率、室上性早搏和室性早搏方面的情况。结果 贴片式心电仪和Holter的平均心率分别为71.87±9.28和72.55±9.06（P＝0.0879）。两种检测方法，室上性早搏的符合率（PPS）为 98.33%，95%CI为（91.06,99.96），Kappa=0.9462, 95%CI为（0.84,1.00）,一致性良好。室性早搏的符合率（PPS）为 98.33%，95%CI为（91.06,99.63），Kappa=0.9850, 95%CI为（0.90, 1.00）。贴片式心电仪平台适合自学、临床监护学习、大课和专业技能考核等临床心电教学。结论 贴片式心电仪在检测平均心率、室上性早搏和室性早搏方面的有效性和Holter相同。同时也适合以此平台开展临床心电教学