4,388 research outputs found
Measuring the anomalous quartic gauge couplings in the process at muon collider using artificial neural networks
The muon collider provides a unique opportunity to study the vector boson
scattering processes and dimension-8 operators contributing to anomalous
quartic gauge couplings. Because of the cleaner final state, it is easier to
decode subprocess and certain operator couplings at a muon collider. We attempt
to identify the anomalous coupling in scattering in this
paper. The vector boson scattering process corresponding to the anomalous
coupling is , with
four (anti-)neutrinos in the final state, which pose difficulties for
phenomenological studies. In this paper, the machine learning method is used to
tackle this problem. We find that, the artificial neural network can be used to
extract the contribution, and is useful to reconstruct the
center of mass energy of the subprocess which is important in the study of the
Standard Model effective field theory. The sensitivities and the expected
constraints on the dimension-8 operators at the muon collider with
TeV are presented. The artificial neural networks exhibit great
potential in the phenomenological study of processes with multiple neutrinos in
the final state.Comment: 26 pages, 11 figures, 7 table
Spectroscopic visualization of flat bands in magic-angle twisted monolayer-bilayer graphene: localization-delocalization coexisting electronic states
Recent transport studies have demonstrated the great potential of twisted
monolayer-bilayer graphene (tMBG) as a new platform to host moir\'e flat bands
with a higher tunability than twisted bilayer graphene (tBG). However, a direct
visualization of the flat bands in tMBG and its comparison with the ones in tBG
remain unexplored. Here, via fabricating on a single sample with exactly the
same twist angle of ~1.13{\deg}, we present a direct comparative study between
tMBG and tBG using scanning tunneling microscopy/spectroscopy. We observe a
sharp density of states peak near the Fermi energy in tunneling spectroscopy,
confirming unambiguously the existence of flat electronic bands in tMBG. The
bandwidth of this flat-band peak is found to be slightly narrower than that of
the tBG, validating previous theoretical predictions. Remarkably, by measuring
spatially resolved spectroscopy, combined with continuum model calculation, we
show that the flat-band states in tMBG exhibit a unique layer-resolved
localization-delocalization coexisting feature, which offers an unprecedented
possibility to utilize their cooperation on exploring novel correlation
phenomena. Our work provides important microscopic insight of flat-band states
for better understanding the emergent physics in graphene moir\'e systems.Comment: 15 pages, 4 figure
Large-scale single-photon imaging
Benefiting from its single-photon sensitivity, single-photon avalanche diode
(SPAD) array has been widely applied in various fields such as fluorescence
lifetime imaging and quantum computing. However, large-scale high-fidelity
single-photon imaging remains a big challenge, due to the complex hardware
manufacture craft and heavy noise disturbance of SPAD arrays. In this work, we
introduce deep learning into SPAD, enabling super-resolution single-photon
imaging over an order of magnitude, with significant enhancement of bit depth
and imaging quality. We first studied the complex photon flow model of SPAD
electronics to accurately characterize multiple physical noise sources, and
collected a real SPAD image dataset (64 32 pixels, 90 scenes, 10
different bit depth, 3 different illumination flux, 2790 images in total) to
calibrate noise model parameters. With this real-world physical noise model, we
for the first time synthesized a large-scale realistic single-photon image
dataset (image pairs of 5 different resolutions with maximum megapixels, 17250
scenes, 10 different bit depth, 3 different illumination flux, 2.6 million
images in total) for subsequent network training. To tackle the severe
super-resolution challenge of SPAD inputs with low bit depth, low resolution,
and heavy noise, we further built a deep transformer network with a
content-adaptive self-attention mechanism and gated fusion modules, which can
dig global contextual features to remove multi-source noise and extract
full-frequency details. We applied the technique on a series of experiments
including macroscopic and microscopic imaging, microfluidic inspection, and
Fourier ptychography. The experiments validate the technique's state-of-the-art
super-resolution SPAD imaging performance, with more than 5 dB superiority on
PSNR compared to the existing methods
External Application of Traditional Chinese Medicine for Venous Ulcers: A Systematic Review and Meta-Analysis
Objective. To evaluate the effectiveness of external application of traditional Chinese medicine (EA-TCM) on venous ulcers. Methods. Seven databases were searched until April 2015 for randomized controlled trials (RCTs) of EA-TCM for venous ulcers. Risk of bias was assessed using Cochrane Handbook guidelines. Study outcomes were presented as risk ratios (RRs) for dichotomous data or mean differences (MDs) for continuous data. Results. Sixteen of 193 potentially relevant trials met the inclusion criteria; however, their methodological qualities were low. Comparison of the same intervention strategies revealed significant differences in total effectiveness rates between EA-TCM and conventional therapy groups (RR = 1.22, 95% confidence interval [CI] = 1.16–1.29, and P<0.00001). Compared to conventional therapy, EA-TCM combined with conventional therapy had a superior total effectiveness rate (RR = 1.11, 95% CI = 1.04–1.19, and P=0.003). There were no significant differences in recurrence rates during followup and final pain measurements between the experimental and those in the control groups (RR = 0.86, 95% CI = 0.31–2.39, and P=0.85; MD −0.75, 95% CI = −2.15–0.65, and P=0.29). Conclusion. The evidence that EA-TCM is an effective treatment for venous ulcers is encouraging, but not conclusive due to the low methodological quality of the RCTs. Therefore, more high-quality RCTs with larger sample sizes are required
The role of Vps4 in cancer development
VPS4 series proteins play a crucial role in the endosomal sorting complexes required for the transport (ESCRT) pathway, which is responsible for sorting and trafficking cellular proteins and is involved in various cellular processes, including cytokinesis, membrane repair, and viral budding. VPS4 proteins are ATPases that mediate the final steps of membrane fission and protein sorting as part of the ESCRT machinery. They disassemble ESCRT-III filaments, which are vital for forming multivesicular bodies (MVBs) and the release of intraluminal vesicles (ILVs), ultimately leading to the sorting and degradation of various cellular proteins, including those involved in cancer development and progression. Recent studies have shown a potential relationship between VPS4 series proteins and cancer. Evidence suggests that these proteins may have crucial roles in cancer development and progression. Several experiments have explored the association between VPS4 and different types of cancer, including gastrointestinal and reproductive system tumors, providing insight into the underlying mechanisms. Understanding the structure and function of VPS4 series proteins is critical in assessing their potential role in cancer. The evidence supporting the involvement of VPS4 series proteins in cancer provides a promising avenue for future research and therapeutic development. However, further researches are necessary to fully understand the mechanisms underlying the relationship between VPS4 series proteins and cancer and to develop effective strategies for targeting these proteins in cancer therapy. This article aims to review the structures and functions of VPS4 series proteins and the previous experiments to analyze the relationship between VPS4 series proteins and cancer
The Mediating Effects of Stigma on Depressive Symptoms in Patients With Tuberculosis: A Structural Equation Modeling Approach
Objectives: To date, the complex interrelationships between family function, doctor-patient communication, knowledge about tuberculosis (TB), stigma, and depressive symptoms among patients with TB are insufficiently understood. We explored the interrelationships between family function, doctor-patient communication, knowledge about TB, TB-related stigma, and depressive symptoms and examined whether TB-related stigma played a mediating role.Methods: A cross-sectional survey was conducted between October 1, 2013 and March 31, 2014 in Hubei province, central China. Data were collected from 1,309 patients with TB using a structured questionnaire that measured family function, doctor-patient communication, knowledge about TB, stigma, and depressive symptoms. Structural equation modeling was used to examine the interrelationships among the study variables based on the hypothesized model.Results: The proposed model provided a good fit to the obtained data. There were indirect effects between family function, doctor-patient communication, knowledge about TB, and depressive symptoms through stigma (β = −0.048, P = 0.002; β = −0.028, P = 0.001; β = −0.021, P = 0.009, respectively). Stigma partially mediated the effect of family function and knowledge about TB on depressive symptoms and fully mediated the effect of doctor-patient communication on depressive symptoms.Conclusions: This study elucidated the pathways linking family function, doctor-patient communication, and knowledge about TB to depressive symptoms and confirmed that the effect of those variables on depressive symptoms can be mediated by stigma. Those findings provide direction and information for depression interventions among patients with TB
Uptake of HIV testing and its correlates among sexually experienced college students in Southwestern, China: a Web-Based online cross-sectional study
BACKGROUND: The prevalence of human immunodeficiency virus (HIV) is becoming more common among college students in China. However, latest data on the prevalence and correlates of HIV testing among sexually experienced college students is rarely.
METHODS: An online survey was conducted among college students aged 18 years or older using multistage stratified cluster sampling from 16 colleges. Data on socio-demographic, HIV testing, HIV-related awareness, attitudes, sexual education and behaviors were collected. Propensity score matching (PSM) and logistic regression model were used to identify factors associated with HIV testing.
RESULT: A total of 108,987 students participated the survey, of which 13,201 sexually experienced college students were included in this study. 1,939 (14.69%) college students with sexual experience reported uptake of HIV testing in the preceding year. The uptake of HIV testing increased for college students with a rising HIV knowledge score and sexual health knowledge. Being awareness of HIV-related knowledge (aOR = 1.15, 95%CI: 1.01-1.30), accepting one-night stands (aOR = 1.16, 95%CI:1.03-1.32), obtaining satisfactory sexual interpretation from parent(s) (aOR = 1.24, 95%CI: 1.07-1.43), ever had unintended pregnancy (aOR = 1.78, 95%CI: 1.32-2.38), ever had received HIV-related preventive service(s) (aOR = 1.37, 95%CI: 1.10-1.70), ever had participated HIV-related preventive services (aOR = 3.76, 95%CI: 2.99-4.75) and ever had anal sex (aOR = 2.66, 95%CI: 2.11-3.34) were positively associated with uptake of HIV testing. However, accepting premarital sex (aOR = 0.76, 95%CI: 0.66-0.88), accepting cohabitation (aOR = 0.75, 95%CI: 0.61-0.92), occasionally discussing sex with parent(s) (aOR = 0.68, 95%CI: 0.50-0.91), and being with moderate satisfaction of school sex courses (aOR = 0.74, 95%CI: 0.58-0.95) were negatively associated with uptake of HIV testing.
CONCLUSION: The prevalence of HIV testing was relatively low. Participation in HIV-related services and high-risk sexual behaviors were important enablers for testing. Improving sex education for students, increasing HIV preventive services on campus, and improving family sex education are necessary to increase HIV testing among college sexually experienced students
Theory and Experiments of Pressure-Tunable Broadband Light Emission from Self-Trapped Excitons in Metal Halide Crystals
Hydrostatic pressure has been commonly applied to tune broadband light
emissions from self-trapped excitons (STE) in perovskites for producing white
light and study of basic electron-phonon interactions. However, a general
theory is still lacking to understand pressure-driven evolution of STE
emissions. In this work we first identify a theoretical model that predicts the
effect of hydrostatic pressure on STE emission spectrum, we then report the
observation of extremely broadband photoluminescence emission and its wide
pressure spectral tuning in 2D indirect bandgap CsPb2Br5 crystals. An excellent
agreement is found between the theory and experiment on the peculiar
experimental observation of STE emission with a nearly constant spectral
bandwidth but linearly increasing energy with pressure below 2 GPa. Further
analysis by the theory and experiment under higher pressure reveals that two
types of STE are involved and respond differently to external pressure. We
subsequently survey published STE emissions and discovered that most of them
show a spectral blue-shift under pressure, as predicted by the theory. The
identification of an appropriate theoretical model and its application to STE
emission through the coordinate configuration diagram paves the way for
engineering the STE emission and basic understanding of electron-phonon
interaction
- …