Construction of the Au Nanoparticle/Graphene Oxide/Au Nanotube (AuNP/GO/AuNT) Sandwich Membrane for Surface-Enhanced Raman Scattering Sensing.

Au nanotube-based composite membrane served as surface-enhanced Raman scattering (SERS) substrate with an ultralarge aspect ratio possesses an excellent flexibility and widely tunable surface plasmon resonance, and by introducing graphene oxide (GO) as a spacer layer, the SERS enhancement of the composite membrane is obviously better than those from the individual blocks of the Au nanotubes (AuNTS) membrane and the Au nanoparticle/graphene oxide (AuNP/GO) membrane. Such a "sandwich" (AuNP/GO/AuNT) structured membrane has a high SERS sensitivity and a wide tunability by controlling the size of Au nanoparticles and the thickness of graphene oxide, and the detection limits of the AuNP/GO/AuNT substrate for R6G and NBA are as low as 10 and 10 M, respectively; the large enhancement is attributed to the adsorption and chemical mechanism of graphene oxide and the physical mechanism of the Au nanoparticles and nanotubes (the electromagnetic field coupling between them).

Spreading evolution of a linear phase-locked hollow beam array in atmospheric turbulence.

Based on the generalized Huygens-Fresnel principle, propagation characteristics of a linear phase-locked hollow beam (PLHB) array propagating through atmospheric turbulence are investigated. Analytical expressions of the average intensity and mean-squared beam width of the PLHB array are derived. It is shown that propagation properties of a PLHB array are related to the initial beam parameters (i.

Sleep Disturbances Are Associated With Depressive Symptoms in a Chinese Population: The Rugao Longevity and Aging Cohort.

To investigate the cross-sectional and longitudinal relationships between sleep disturbances and depressive symptoms in older Chinese adults. This study included baseline and 3.5-year follow-up data of 1,631 Chinese men and women aged 70 years or older from the aging arm of the Rugao Longevity and Aging Study.

Thermal blooming induced phase change and its compensation of a Gaussian beam propagation in an absorbing medium: publisher's note.

This publisher's note contains corrections to Opt. Lett.46, 4304 (2021)OPLEDP0146-959210.

Thermal blooming induced phase change and its compensation of a Gaussian beam propagation in an absorbing medium.

A high-power laser beam propagating in an absorbing medium, thermal blooming causes phase distortion, which is severe for the beam quality. In this Letter, a feasible approach for obtaining the phase change induced by thermal blooming is proposed. In addition, based on the aforementioned phase change, an alternative solution of phase compensation near the receiver is provided, which may enrich the previous compensation method (i.

Clinical characteristics of Kawasaki disease and concurrent pathogens during isolation in COVID-19 pandemic.

Background: The aim of this study is to explore the characteristics of Kawasaki disease (KD) and concurrent pathogens due to a stay-at-home isolation policy during coronavirus disease 2019 (COVID-19) epidemic.

Methods: All patients with KD admitted between February and April in 2015-2020, were classified into before (group 1, in 2015-2019) and after (group 2, in 2020) isolation groups. A total of 4742 patients [with KD (n = 98) and non-KD (n = 4644)] referred to Mycoplasma pneumoniae (MP) and virus detection were analyzed in 2020.

Genome-wide DNA methylation analysis of peripheral blood cells derived from patients with first-episode schizophrenia in the Chinese Han population.

Schizophrenia is a severe neuropsychiatric disorder with core features including hallucinations, delusions, and cognition deficits. Accumulating evidence has implicated abnormal DNA methylation in the development of schizophrenia. However, the mechanisms by which DNA methylation changes alter the risk for schizophrenia remain largely unknown.

Health status and associated factors of HIV-infected patients in Kunming, China.

Objective: To assess health status of HIV-positive patients and to examine its predictors in Kunming, China.

Methods: HIV-positive patients were recruited from a general hospital and an infection hospital in 2015. Health status of the patients was evaluated using standardized questions on eight health domains (mobility, self-care, pain and discomfort, cognition, interpersonal activities, vision, sleep and energy, and emotional distress) of the WHO World Health Survey.

Nuclear Norm Clustering: a promising alternative method for clustering tasks.

Clustering techniques are widely used in many applications. The goal of clustering is to identify patterns or groups of similar objects within a dataset of interest. However, many cluster methods are neither robust nor sensitive to noises and outliers in real data.

Use of weather research and forecasting model outputs to obtain near-surface refractive index structure constant over the ocean.

The methods to obtain atmospheric refractive index structure constant (Cn2) by instrument measurement are limited spatially and temporally and they are more difficult and expensive over the ocean. It is useful to forecast Cn2 effectively from Weather Research and Forecasting Model (WRF) outputs. This paper introduces a method that WRF Model is used to forecast the routine meteorological parameters firstly, and then Cn2 is calculated based on these parameters by the Bulk model from the Monin-Obukhov similarity theory (MOST) over the ocean near-surface.

Average intensity of M × N Gaussian array beams in oceanic turbulence.

Based on the power spectrum of oceanic turbulence proposed by Nikishov, the analytical expressions for average intensity of M×N Gaussian array beams propagating in oceanic turbulence are derived, where the coherent and incoherent combinations are considered. Using the focused beam, the intensity can be received at the same point. The changes of the average intensity versus three oceanic parameters are investigated.

Influence of oceanic turbulence on propagation of a radial Gaussian beam array.

The analytical expression for the root-mean-square (Rms) beam width of the radial Gaussian beam array propagating in oceanic turbulence is derived, where the coherent combination is considered. Meanwhile, the analytical expression for effect of the turbulence on the beam F is also obtained. Giving a comparison of results of F calculated by the analytical expression and the previously integrating one, it can be seen that the two results are in agreement with each other exactly.

Two-wavelength ghost imaging through atmospheric turbulence.

Recent work has indicated that ghost imaging might find useful application in standoff sensing where atmospheric turbulence is a serious problem. There has been theoretical study of ghost imaging in the presence of turbulence. However, most work has addressed signal-wavelength ghost imaging.

Adaptive optical ghost imaging through atmospheric turbulence.

We demonstrate for the first time (to our knowledge) that a high-quality image can still be obtained in atmospheric turbulence by applying adaptive optical ghost imaging (AOGI) system even when conventional ghost imaging system fails to produce an image. The performance of AOGI under different strength of atmospheric turbulence is investigated by simulation. The influence of adaptive optics system with different numbers of adaptive mirror elements on obtained image quality is also studied.

Propagation of Gaussian-Schell beam in turbulent atmosphere of three-layer altitude model.

We propose a method that is used to derive the moment radius of intensity distribution in a turbulent atmosphere. From this study, we have found that the second moment radius is affected only by the first-order expansion coefficient of the wave structure function. If our attention is directed to a higher moment radius, a higher order approximation of the expansion needs to be used.

Light filaments with higher-order Kerr effect.

The influence mechanism of higher-order Kerr effect on the propagation of laser beam is investigated by a modified model, which indicates that a collapsing wave will transform into a universe blowup profile. The analysis of higher-order terms of the nonlinear refractive index shows that the filamentation process can be induced by Kerr self-focusing without the occurrence of the ionization effect. The determining role of the combination of self-focusing and spontaneous defocusing and the energy reservoir in formation of lengthy filament is confirmed visually.