Importance Lymph node status is the primary determinant in treatment decision making in early gastric cancer (EGC). Current evaluation methods are not adequate for estimating lymph node metastasis (LNM) in EGC. Objective To develop and validate a prediction model based on a fully quantitative collagen signature in the tumor microenvironment to estimate the individual risk of LNM in EGC. Design, setting, and participants This retrospective study was conducted from August 1, 2016, to May 10, 2018, at 2 medical centers in China (Nanfang Hospital and Fujian Provincial Hospital). Participants included a primary cohort (n = 232) of consecutive patients with histologically confirmed gastric cancer who underwent radical gastrectomy and received a T1 gastric cancer diagnosis from January 1, 2008, to December 31, 2012. Patients with neoadjuvant radiotherapy, chemotherapy, or chemoradiotherapy were excluded. An additional consecutive cohort (n = 143) who received the same diagnosis from January 1, 2011, to December 31, 2013, was enrolled to provide validation. Baseline clinicopathologic data of each patient were collected. Collagen features were extracted in specimens using multiphoton imaging, and the collagen signature was constructed. An LNM prediction model based on the collagen signature was developed and was internally and externally validated. Main outcomes and measures The area under the receiver operating characteristic curve (AUROC) of the prediction model and decision curve were analyzed for estimating LNM. Results In total, 375 patients were included. The primary cohort comprised 232 consecutive patients, in whom the LNM rate was 16.4% (n = 38; 25 men [65.8%] with a mean [SD] age of 57.82 [10.17] years). The validation cohort consisted of 143 consecutive patients, in whom the LNM rate was 20.9% (n = 30; 20 men [66.7%] with a mean [SD] age of 54.10 [13.19] years). The collagen signature was statistically significantly associated with LNM (odds ratio, 5.470; 95% CI, 3.315-9.026; P Conclusions and relevance This study's findings suggest that the collagen signature in the tumor microenvironment is an independent indicator of LNM in EGC, and the prediction model based on this collagen signature may be useful in treatment decision making for patients with EGC.

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Association of the Collagen Signature in the Tumor Microenvironment With Lymph Node Metastasis in Early Gastric Cancer

In this letter, the scattering of a nondiffractive Bessel beam (BB) incident field by a perfect electric conducting circular cylinder is investigated and compared with the standard scattering solution by a plane wave It is proven that the BB incident field improves the validity of standard physical optics approximation and possibly extends its range of applicability to cylinders, or more general scatterers, whose curvature radius is not much larger than the operating wavelength This offers new effective possibilities in the solutions of different electromagnetic scattering problems

Improving Physical Optics Approximation Through Bessel Beam Scattering

Resonant Bessel-beam launchers are low-cost, planar, miniaturized devices capable of focusing electromagnetic radiation in a very efficient way in various frequency ranges, with recent increasing interest for microwave and millimeter-wave applications (i.e., 3–300 GHz). In recent years, various kinds of launchers have appeared, with different feeding mechanisms (e.g., coaxial probes, resonant slots, or loop antennas), field polarization (radial, azimuthal, and longitudinal), and manufacturing technology (axicon lenses, radial waveguides, or diffraction gratings). In this paper, we review the various features of these launchers both from a general electromagnetic background and a more specific leaky-wave interpretation. The latter allows for deriving a useful set of design rules that we here show to be applicable to any type of launcher, regardless its specific realization. Practical examples are discussed, showing a typical application of the proposed design workflow, along with a possible use of the launchers in a modern context, such as that of wireless power transfer at 90 GHz.

https://www.mdpi.com/2072-666X/13/12/2230/pdf?version=1671116022

A Leaky-Wave Analysis of Resonant Bessel-Beam Launchers: Design Criteria, Practical Examples, and Potential Applicationsat Microwave and Millimeter-Wave Frequencies

This paper deals with both forward and inverse electromagnetic scattering of metallic objects by focused Bessel-shaped incident field. After discussing the main features of this kind of field, it is shown that its focusing capabilities may offer new effective possibilities for the detection of metallic targets which are not so far extended with respect to the probing wavelength, i.e., not satisfying the hypotheses of physical optics approximation. Numerical examples are performed by means of full-wave simulations, and then inversion algorithms based on back-propagation and physical optics are exploited to show that more accurate reconstructions can be pursued using Bessel-shaped fields. 

/pdf/forward-and-inverse-scattering-of-metallic-objects-through-1f9ps161.pdf

Forward and Inverse Scattering of Metallic Objects Through Focused Bessel-Shaped Fields

We have designed a trench-assisted optical fiber that can generate Bessel beams with different shapes in the fundamental mode. The trench-assisted structure is nested by rings with different refractive indexes on the cross-section. The fundamental mode field properties of the trench-assisted fiber are analyzed by using the finite element method. For the wavelengths from 400 nm to 2500 nm, the fundamental modes appear as Bessel beams with different shapes. The zero-order Bessel beams exhibit at the longer wavelength region, and the higher-order Bessel beams show at the shorter wavelength region. The Bessel beams’ shape can also be adjusted by tuning the structure parameters on the cross-section of the designed trench-assisted fiber.

/pdf/design-of-a-trench-assisted-optical-fiber-for-generating-22qdahyh.pdf

Design of a Trench-Assisted Optical Fiber for Generating Bessel Beams With Different Shapes

Optical imaging of stained pathological slices has become the gold standard for disease diagnosis. However, the procedure of sample preparation is complex and time-consuming. Multiphoton microscopy (MPM) is promising for label-free imaging, but the imaging speed is limited, especially for whole slice imaging. Here we propose a high-speed, multi-modal, label-free MPM by Bessel scan-based strip mosaicking. With a Bessel beam for excitation, the extended depth-of-focus not only enables full axial information acquisition at once, but also alleviates the demanding requirement of sample alignment. With the strip mosaicking protocol, we can save the time of frequent sample transferring. Besides, we add a closely-attached reflection mirror under the sample for enhancing epi-detection signals, and employ circularly polarized beams for recording comprehensive information. We demonstrate its application in multi-modal, label-free imaging of human gastric cancer slices and liver cancer slices, and show its potential in rapid disease diagnosis.

Guoqiang Gao

Papers

High-speed, multi-modal, label-free imaging of pathological slices with a Bessel beam.