A hybrid single-mode laser based on slotted silicon waveguides

An InGaAsP-Si hybrid single-mode laser based on etched slots in silicon waveguides was demonstrated operating at 1543 nm. The InGaAsP gain structure was bonded onto a patterned silicon-on-insulator wafer by selective area metal bonding method. The mode-selection mechanism based on a slotted silicon waveguide was applied, in which the parameters were designed using the simulation tool cavity modeling framework. The III-V lasers employed buried ridge stripe structure. The whole fabrication process only needs standard photolithography and inductively coupled plasma etching technology, which reduces cost for ease in technology transfer. At room temperature, a single mode of 1543-nm wavelength at a threshold current of 21 mA with a maximum output power of 1.9 mW in continuous-wave regime was obtained. The side mode suppression ratio was larger than 35 dB. The simplicity and flexibility of the fabrication process and a low cost make the slotted hybrid laser a promising light source

A04: A Pilot Study on the Persistence of Children\u27s Online Sports Games

Purpose: In the post-epidemic era, children\u27s physical activity has decreased sharply, and smart sports at home have gradually emerged, making online sports games an important path for children\u27s sports participation. This pilot study was to explore the persistence of children\u27s online sports game participation through exercise frequency recording and provided guidance for online sports game intervention programs. Methods: A total of 29 primary school children were enrolled, including 24 boys and 5 girls. Participants exercise autonomously through motion software. In this study, the movement of each participant was recorded through the background of the software system and exported to Excel. Two-week period was used as one stage and a total of six stages were analyzed. After preliminary collation of the data, one-way ANOVA using SPSS23.0 was performed. Results: By analyzing the motion records of the 12 weeks of online exercise, overall trend of the first five stages is linear decreasing, and the trend of the fifth and sixth stages is flat; There was no significant difference between the first stage and the fourth stage (p \u3e 0.05). The first and fifth and sixth stages showed that the differences (p \u3c 0.01). The difference between the second and sixth stages was significant (p \u3c 0.05), and the difference between the second and fifth phases was very significant (p \u3c 0.01). Conclusions: Online sports games have a certain attraction to children, ensuring the frequency of children\u27s early sports participation, but this attraction is difficult to last for a long time. Children\u27s interest in sports will decline to varying degrees with time. It is recommended to further improve and stabilize the persistence of children\u27s participation by formulating external behavioral intervention strategies and adjusting internal intervention programs

Thermal Annealing of Exfoliated Graphene

Monolayer graphene is obtained by mechanical exfoliation using scotch tapes. The effects of thermal annealing on the tape residues and edges of graphene are researched. Atomic force microscope images showed that almost all the residues could be removed in N2/H2 at 400°C but only agglomerated in vacuum. Raman spectra of the annealed graphene show both the 2D peak and G peak blueshift. The full width at half maximum (FWHM) of the 2D peak becomes larger and the intensity ratio of the 2D peak to G peak decreases. The edges of graphene are completely attached to the surface of the substrate after annealing

PND-Net: Physics based Non-local Dual-domain Network for Metal Artifact Reduction

Metal artifacts caused by the presence of metallic implants tremendously degrade the reconstructed computed tomography (CT) image quality, affecting clinical diagnosis or reducing the accuracy of organ delineation and dose calculation in radiotherapy. Recently, deep learning methods in sinogram and image domains have been rapidly applied on metal artifact reduction (MAR) task. The supervised dual-domain methods perform well on synthesized data, while unsupervised methods with unpaired data are more generalized on clinical data. However, most existing methods intend to restore the corrupted sinogram within metal trace, which essentially remove beam hardening artifacts but ignore other components of metal artifacts, such as scatter, non-linear partial volume effect and noise. In this paper, we mathematically derive a physical property of metal artifacts which is verified via Monte Carlo (MC) simulation and propose a novel physics based non-local dual-domain network (PND-Net) for MAR in CT imaging. Specifically, we design a novel non-local sinogram decomposition network (NSD-Net) to acquire the weighted artifact component, and an image restoration network (IR-Net) is proposed to reduce the residual and secondary artifacts in the image domain. To facilitate the generalization and robustness of our method on clinical CT images, we employ a trainable fusion network (F-Net) in the artifact synthesis path to achieve unpaired learning. Furthermore, we design an internal consistency loss to ensure the integrity of anatomical structures in the image domain, and introduce the linear interpolation sinogram as prior knowledge to guide sinogram decomposition. Extensive experiments on simulation and clinical data demonstrate that our method outperforms the state-of-the-art MAR methods.Comment: 19 pages, 8 figure

Epidemiologic trends and survival of early-onset gastroenteropancreatic neuroendocrine neoplasms

BackgroundThe epidemiologic trends and survival related to early-onset gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have not been well explored.MethodsTrends in the incidence and incidence-based mortality of early-onset GEP-NENs between 1975 and 2018 were obtained from the Surveillance, Epidemiology, and End Results database, and were stratified by age, sex, race, tumor site, stage, and grade. Associated population data were used to determine overall survival (OS) and independent prognostic factors for patients with early-onset GEP-NENs.ResultsA total of 17299 patients diagnosed with early-onset GEP-NENs were included in this study. Results revealed an increase in the incidence (5.95% per year, 95% confidence interval (CI), 5.75-6.14%) and incidence-based mortality (4.24% per year, 95% CI, 3.92-4.56%) for early-onset GEP-NENs from 1975 to 2018, with higher rates of increase than those of later-onset GEP-NENs (incidence: 4.45% per year, 95% CI, 4.38-4.53; incidence-based mortality: 4.13% per year, 95% CI, 3.89-4.37; respectively). Increases in incidence were observed across all age, races, tumor sites, grades, and stages, except for patients with unknown stage. Compared to those with later-onset GEP-NENs, a higher proportion of female gender (54.5% vs. 49.0%, p <0.001), well-differentiated tumor (31.1% vs. 28.0%, p <0.05), and localized disease (55.2% vs. 46.7%, p <0.05) were observed in the cohort of patients with early-onset GEP-NENs. Moreover, early-onset GEP-NENs exhibited a superior overall survival in comparison to later-onset GEP-NENs, irrespective of tumor site, grade, or stage (p <0.0001). Multivariable survival analysis identified that race, marital status, stage, grade, chemotherapy, and primary site were significantly correlated with OS in individuals with early-onset GEP-NENs.ConclusionsThe incidence and incidence-based mortality rates of early-onset GEP-NENs have steadily increased over time, with higher rates of increase than those of later-onset GEP-NENs. The clinical characteristics and survival were different between early-onset and later-onset GEP-NENs groups. Race, marital status, stage, grade, chemotherapy, and primary site were independent prognostic factors for early-onset GEP-NENs. Further investigations are warranted to better understand the characteristics of this disease subgroup

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum