884 research outputs found

    Asymptotic expansions and fast computation of oscillatory Hilbert transforms

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    In this paper, we study the asymptotics and fast computation of the one-sided oscillatory Hilbert transforms of the form H+(f(t)eiωt)(x)=int0eiωtf(t)txdt,ω>0,x0,H^{+}(f(t)e^{i\omega t})(x)=-int_{0}^{\infty}e^{i\omega t}\frac{f(t)}{t-x}dt,\qquad \omega>0,\qquad x\geq 0, where the bar indicates the Cauchy principal value and ff is a real-valued function with analytic continuation in the first quadrant, except possibly a branch point of algebraic type at the origin. When x=0x=0, the integral is interpreted as a Hadamard finite-part integral, provided it is divergent. Asymptotic expansions in inverse powers of ω\omega are derived for each fixed x0x\geq 0, which clarify the large ω\omega behavior of this transform. We then present efficient and affordable approaches for numerical evaluation of such oscillatory transforms. Depending on the position of xx, we classify our discussion into three regimes, namely, x=O(1)x=\mathcal{O}(1) or x1x\gg1, 0<x10<x\ll 1 and x=0x=0. Numerical experiments show that the convergence of the proposed methods greatly improve when the frequency ω\omega increases. Some extensions to oscillatory Hilbert transforms with Bessel oscillators are briefly discussed as well.Comment: 32 pages, 6 figures, 4 table

    Controlled Synthesis of Organic/Inorganic van der Waals Solid for Tunable Light-matter Interactions

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    Van der Waals (vdW) solids, as a new type of artificial materials that consist of alternating layers bonded by weak interactions, have shed light on fascinating optoelectronic device concepts. As a result, a large variety of vdW devices have been engineered via layer-by-layer stacking of two-dimensional materials, although shadowed by the difficulties of fabrication. Alternatively, direct growth of vdW solids has proven as a scalable and swift way, highlighted by the successful synthesis of graphene/h-BN and transition metal dichalcogenides (TMDs) vertical heterostructures from controlled vapor deposition. Here, we realize high-quality organic and inorganic vdW solids, using methylammonium lead halide (CH3NH3PbI3) as the organic part (organic perovskite) and 2D inorganic monolayers as counterparts. By stacking on various 2D monolayers, the vdW solids behave dramatically different in light emission. Our studies demonstrate that h-BN monolayer is a great complement to organic perovskite for preserving its original optical properties. As a result, organic/h-BN vdW solid arrays are patterned for red light emitting. This work paves the way for designing unprecedented vdW solids with great potential for a wide spectrum of applications in optoelectronics

    Timing and setting of billed advance care planning among Medicare decedents in 2017-2019.

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    BACKGROUND: The Centers for Medicare &amp; Medicaid Services (CMS) began to reimburse clinicians for advance care planning (ACP) discussions, effective January 1, 2016. We sought to characterize the timing and setting of first-billed ACP discussions among Medicare decedents to inform future research on ACP billing codes. METHODS: Using a random 20% sample of Medicare fee-for-service beneficiaries aged 66 years and older who died in 2017-2019, we described the timing (relative to death) and setting (inpatient, nursing home, office, or outpatient with or without Medicare Annual Wellness Visit [AWV], home or community, or elsewhere) of the first-billed ACP discussion for each beneficiary. RESULTS: Our study included 695,985 decedents (mean [SD] years of age, 83.2 [8.8]; 54.2% female); the proportion of decedents who had at least one billed ACP discussion increased from 9.7% in 2017 to 21.9% in 2019. We found that the proportion of first-billed ACP discussions held during the last month of life decreased from 37.0% in 2017 to 26.2% in 2019, while the proportion of first-billed ACP discussions held more than 12 months before death increased from 11.1% in 2017 to 35.2% in 2019. We also found that the proportion of first-billed ACP discussions held in the office or outpatient setting along with AWV increased over time (from 10.7% in 2017 to 14.1% in 2019), while the proportion held in the inpatient setting decreased (from 41.7% in 2017 to 38.0% in 2019). CONCLUSIONS: We found that with increasing exposure to the CMS policy change, uptake of the ACP billing code has increased; first-billed ACP discussions are occurring sooner before the end-of-life stage and are more likely to occur with AWV. Future studies should evaluate changes in ACP practice patterns, rather than only an increasing uptake in ACP billing codes, following the policy implementation

    Advancing H&E-to-IHC Stain Translation in Breast Cancer: A Multi-Magnification and Attention-Based Approach

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    Breast cancer presents a significant healthcare challenge globally, demanding precise diagnostics and effective treatment strategies, where histopathological examination of Hematoxylin and Eosin (H&E) stained tissue sections plays a central role. Despite its importance, evaluating specific biomarkers like Human Epidermal Growth Factor Receptor 2 (HER2) for personalized treatment remains constrained by the resource-intensive nature of Immunohistochemistry (IHC). Recent strides in deep learning, particularly in image-to-image translation, offer promise in synthesizing IHC-HER2 slides from H\&E stained slides. However, existing methodologies encounter challenges, including managing multiple magnifications in pathology images and insufficient focus on crucial information during translation. To address these issues, we propose a novel model integrating attention mechanisms and multi-magnification information processing. Our model employs a multi-magnification processing strategy to extract and utilize information from various magnifications within pathology images, facilitating robust image translation. Additionally, an attention module within the generative network prioritizes critical information for image distribution translation while minimizing less pertinent details. Rigorous testing on a publicly available breast cancer dataset demonstrates superior performance compared to existing methods, establishing our model as a state-of-the-art solution in advancing pathology image translation from H&E to IHC staining.Comment: Accepted by IEEE CIS-RAM 2024 Invited Session Ora

    Circular RNA Hsa_Circ_0091579 Serves as a Diagnostic and Prognostic Marker for Hepatocellular Carcinoma

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    Background/Aims: An increasing number of studies have suggested that circular RNAs (circRNAs) have vital roles in carcinogenesis and tumor progression. However, the function of circRNAs in hepatocellular carcinoma (HCC) remains poorly characterized. Methods: We investigated the levels of circRNAs in patients with HCC to identify potential diagnostic biomarkers. We examined circRNA expression profiles in liver tumors and paired non-cancerous liver tissues from three HCC patients with cancer thrombus using a circRNA microarray. Bioinformatics analysis was performed to find circRNAs with significantly altered expression levels between tumors and their paired non-tumor tissues. We confirmed our initial findings by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were also applied to identify a candidate circRNA with the optimal specificity and sensitivity. Finally, X-tile software was adopted to calculate the most efficient cut-off value for hsa_circ_0091579 expression. Results: Microarray analysis identified 20 unique circRNAs that were differentially expressed between tumor and non-tumor tissues (P &#x3c; 0.05). The expression of these 20 circRNAs was verified by qRT-PCR. The expression of hsa_circ_16245-1 and hsa_circ_0091579 mRNA was consistent with their levels as tested by the microarray. The ROC curves showed that both hsa_circ_16245-1 and hsa_circ_0091579 had favorable specificity and sensitivity. We further confirmed that hsa_circ_0091579 was significantly upregulated in HCC and its high expression was intimately associated with a worse overall survival in patients with HCC. Conclusion: Hsa_circ_0091579 may play a critical role in HCC progression and serve as a potential biomarker for the prognosis of patients with HCC

    GDDS: A Single Domain Generalized Defect Detection Frame of Open World Scenario using Gather and Distribute Domain-shift Suppression Network

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    Efficient and intelligent surface defect detection of photovoltaic modules is crucial for improving the quality of photovoltaic modules and ensuring the reliable operation of large-scale infrastructure. However, the scenario characteristics of data distribution deviation make the construction of defect detection models for open world scenarios such as photovoltaic manufacturing and power plant inspections a challenge. Therefore, we propose the Gather and Distribute Domain shift Suppression Network (GDDS). It adopts a single domain generalized method that is completely independent of the test samples to address the problem of distribution shift. Using a one-stage network as the baseline network breaks through the limitations of traditional domain generalization methods that typically use two-stage networks. It not only balances detection accuracy and speed but also simplifies the model deployment and application process. The GDDS includes two modules: DeepSpine Module and Gather and Distribute Module. Specifically, the DeepSpine Module applies a wider range of contextual information and suppresses background style shift by acquiring and concatenating multi-scale features. The Gather and Distribute Module collects and distributes global information to achieve cross layer interactive learning of multi-scale channel features and suppress defect instance shift. Furthermore, the GDDS utilizes normalized Wasserstein distance for similarity measurement, reducing measurement errors caused by bounding box position deviations. We conducted a comprehensive evaluation of GDDS on the EL endogenous shift dataset and Photovoltaic inspection infrared image dataset. The experimental results showed that GDDS can adapt to defect detection in open world scenarios faster and better than other state-of-the-art methods.13 image
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