Novel Apodized Fiber Bragg GratingApplied for Medical Sensors:Performance Investigation

Sensors play an important role in shaping and monitoring human health.Exploration of methods to use Fiber Bragg Grating(FBG)with enhanced sensitivity has attracted great interest in the field of medical research.In this paper,a novel apodization function is proposed and performance evaluation and optimization of the same have been made.A comparison was conducted between various existing apodization functions and the proposed one based on optical characteristics and sensor parameters.The results evince the implementation of the proposed apodization function for vital sign measurement.The optical characteristics considered for evaluation are Peak Resonance Reflectivity level,Side Lobes Reflectivity level and FullWidth HalfMaximum(FWHM).The proposed novel apodization novel function has better FWHM,which is narrower than the FWHM of uniform FBG.Sensor characteristics like a quality parameter,detection accuracy and sensitivity also show improvement.The proposed novel apodization function is demonstrated to have a better shift in wavelength in terms of temperature and pulse measurement than the existing functions.The sensitivity of the proposed apodized function is enhanced with a Poly-dimethylsiloxane coating of varying thickness,which is 6 times and 5.14 times greater than uniform Fiber Bragg grating and FBG with the proposed novel apodization function,respectively,enhancing its utilization in the field of medicine.

Fabrication of arbitrarily apodized fiber Bragg gratings with narrow bandwidth

A double-exposure fabrication method without any intensity shadow mask to fabricate arbitrarily apodized fiber Bragg gratings（ FBGs） with narrow bandwidth is demonstrated by controlling the total ultra violet （UV） irradiation along the grating by varying the speed of a translation stage. The UV source used is a stable continuous intracavity frequency-doubled argonion laser. The parameters （such as length, apodization profile, average index change）of FBGs can be easily changed with this method. The total UV irradiation is kept constant in the doubleexposure process because of the precise control of the exposure time, which ensures that the apodized FBG＇s bandwidth can be extremely narrow. The full width at half maximum （FWHM） bandwidth of the 2-cm-long apodized FBG fabricated by this method is 0. 15 nm with a maximum reflectivity of more than 95%.

An apodized cubic phase mask used in a wavefront coding system to extend the depth of field

The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image restoration.This paper proposes a novel apodized cubic phase mask to suppress the side-lobes of the PSF.Simulated annealing algorithm is used to optimize the cubic and the truncation parameter of the phase mask.The system with the novel phase mask has better performance in the modulation transfer function(MTF)especially in low-and-medium spatial frequency region.The simulation results show that the restored images with the novel phase mask are superior to the one with the classic cubic phase mask in contrast and ringing effect.The experimental results show that the side-lobes of the PSF are suppressed by using the apodized cubic phase mask.

Resolution of Two Unequally Bright Points of Apodized Optical Systems with Asymmetric Circular Antenna Arrays

Sparrow criterion of resolution is used for assessment of the resolution of two object points of apodized optical systems under incoherent illumination of light. Semicircular arrays of circular aperture with discrete asymmetric apodization have suppressed side-lobes and a narrower central peak in the image plane termed as PSF good side on alternatively the right and left of the strong spectral point facilitates to detect the presence of weak spectral point in the vicinity of bright spectral point. The results of investigations on optimum discrete pupil function with semicircular arrays on the intensity distributions in the composite image of two object points with widely varying in their intensities under various degree of coherence of illumination have been studied. Sparrow resolution limits and the dip in central intensity as function of degree of coherence of the illumination (γ), intensity ratio (α), degree of asymmetric apodization (b) and number of discrete elements in semicircular array (n). The efficiency of aperture functions is discussed in terms of these parameters. Pupil function capabilities in redistribution of energy in composite image of two object points in close vicinity have been verified for different considerations. Current study has found an improvement in two-point resolution characteristics compared to their unapodized counter part. Fourier analytical properties of an optical system are presented for evaluation of this practical problem.

A high-contrast imaging coronagraph for segmented-mirror large aperture telescopes using a spatial light modulator

The primary mirrors of current and future large telescopes always employ a segmented mirror configuration.The small but non-negligible gaps between neighboring segments cause additional diffraction,which restricts the performance of high-contrast coronagraph.To solve this problem,we propose a coronagraph system based on a single liquid crystal spatial light modulator(SLM).This spatial light modulator is used for amplitude apodization,and its feasibility and potential performance are demonstrated using a laboratory setup using the stochastic parallel gradient descent(SPGD)algorithm to control the spatial light modulator,which is based on point spread function(PSF)sensing and evaluation and optimized for maximum contrast in the discovery working area as a merit function.The system delivers a contrast in the order of 10−6,and shows excellent potential to be used in current and future large aperture telescopes,both on the ground and in space.

Apodized silicon photonic grating couplers for mode-order conversion

An out-of-plane silicon grating coupler capable of mode-order conversion at the chip–fiber interface is designed and fabricated. Optimization of the structure is performed through finite-difference time-domain simulations,and the final device is characterized through far-field profile and transmission measurements. A coupling loss of 3.1 dB to a commercial two-mode fiber is measured for a single TE0→ LP11 mode conversion grating, which includes a conversion penalty of 1.3 dB. Far-field patterns of the excited LP11 mode profile are also reported.

Effects Of Average Index Variation in Apodized Long-Period Fiber Gratings

We analyze the effects of average index variation on the transmission characteristics of an index-apodized long-period fiber grating （LPFG） by the transfer matrix method and study how these effects depend on the grating length, the grating profile, the modal dispersion factor, and the duty cycle of the index modulation. Apart from shifting the resonance wavelength and modifying the rejection band, average index variation can give rise to significant side lobes that may appear on the short-wavelength or long-wavelength side of the rejection band, depending on the signs of the average index change and the modal dispersion factor. Our results provide general guidance for the writing of LPFGs for the minimization of side lobes. Our analysis compares well with published experimental results and should be useful for the design and fabrication of LPFGs.

The role and regulation mechanisms of APOD in prognosis and subtyping of breast cancer

Background:Breast cancer is the most common cancer,and abnormal lipid metabolism is associated with cancer.APOD expression is negatively correlated with various cancers related to tumor prognosis.DNA methylation may affect APOD expression.Therefore,this paper aims to investigate the significance of APOD expression and APOD DNA methylation in breast cancer.Methods:This study utilized comprehensive bioinformatics analysis of APOD using Gene Expression database of Normal and Tumor tissues 2,UCSC Xena,etc.Clinical and survival information obtained from the The Cancer Genome Atlas and Gene Expression Omnibus datasets were extracted for data mining.Results:The correlation between APOD and breast cancer was examined,along with the connection between APOD DNA methylation and APOD expression.In the The Cancer Genome Atlas cohort,as well as GSE31448 and GSE65194 datasets,APOD expression decreased in breast cancer(P<0.0001).Clinical feature analysis results showed that APOD expression was correlated with the PAM50 subtype,with the lowest expression in the Basal subtype(P<0.0001).High APOD expression is a good prognostic marker for breast cancer(HR=0.71,P=0.037).APOD methylation level was significantly negatively correlated with expression level(R=−0.4770,P<0.001),and cg15231202,cg23720929,and cg05624196 were important regulatory targets.High APOD expression was associated with higher metabolism and extracellular matrix scores.Conclusion:APOD is an independent prognostic marker for breast cancer and is regulated by DNA methylation to modulate mRNA expression.

腋臭患者ApoD表达变化及其分子机制的研究

目的:观察与E-3M2H分泌相关的载脂蛋白D(ApoD)和雄激素受体AR在腋臭患者的大汗腺的表达与正常人的差异,探讨导致腋臭患者ApoD表达异常的原因。方法:收集4例正常对照和10例腋臭患者的组织样本,采用免疫组化、realtime-PCR和western-blot检测腋臭患者组织中ApoD、AR的表达水平,通过细胞培养和激素诱导,分析AR信号调控ApoD表达的可能性,并阐明JNK1信号通路在其中扮演的作用。结果:实验发现ApoD和AR在腋臭患者的大汗腺的表达与正常人有明显的差异,腋臭患者中ApoD表达几乎是正常人的2倍;而腋臭患者中AR表达也明显增加,与此同时,腋臭患者中JNK1活化增强。雄激素可以增强正常人ApoD的表达,且该过程中同样伴有JNK1活化;抑制JNK1活化,可以降低腋臭患者和雄激素诱导的ApoD的表达。结论:ApoD表达增加是腋臭患者的重要分子特征,其表达增加与AR信号增强密切相关。JNK1的活化是腋臭患者和雄激素导致的ApoD表达增加的重要原因,抑制JNK1活化,可以抑制腋臭患者内源和雄激素诱导的ApoD的表达。

基于最优三次谐波注入的改进APOD调制

在采用高阶滤波器的三电平变流器中,载波同相层叠调制(phase disposition,PD)产生的开关频率次边带谐波易扩散到高阶滤波器固有谐振点附近,引起输出电流谐波增加或振荡,而载波交替反相层叠(alternative phase opposition disposition,APOD)所需滤波器总电感量较大。针对以上问题,在定量分析比较PD和APOD两种调制方式谐波分布及边带谐波扩散特点的基础上,给出了两种调制方式总电感量约束方程。为保有APOD调制谐波分布集中优点的同时减小APOD总电感量需求,研究了一种基于最优三次谐波注入的改进APOD调制策略,分析了不同三次谐波注入量对APOD电压谐波分布及总电感量需求的影响,进而给出了以总电感量需求最小为目标的三次谐波最优注入量的计算方法,该方法可以实时根据当前调制度自动计算需要注入的三次谐波最优幅值,实现最优三次谐波的在线注入。最后,仿真和实验结果表明,所提策略不仅可以有效地避开高阶滤波器的谐振点,而且可有效降低主导谐波电压幅值,从而减小所需滤波器总电感量。

APOD卫星大气密度数据处理与标校

APOD卫星是我国首颗以热层大气密度探测与精密定轨为科学目标的微纳卫星,搭载大气密度探测器、双频GNSS接收机等载荷,于2015年9月20日发射入轨,2015年10月27日进入轨道高度460km、轨道倾角97.4°、降交点地方时6∶20的工作轨道,各项载荷随即展开例行观测.本文给出了APOD卫星大气密度探测器的基本原理和数据处理流程,采用基于双行根数(TLE)反演获取的密度数据,对2015年12月至2016年12月的就位探测数据进行了标校,并与经验密度模式进行了比较.结果表明,反演密度与APOD卫星就位探测数据的线性相关性达到0.943,采用线性拟合与二次函数拟合的残差水平基本相当.两种不同方法标校密度相对于NRLMSIS00模式日均值误差的均值和标准偏差为10.1%、18.2%和5.1%、17.1%,二次函数标校略优于线性标校;相对于JB2008模式日均值误差的均值和标准偏差为0.6%、14.9%和3.9%、16.9%,线性标校略优于二次函数标校.总体而言,APOD卫星大气密度就位探测数据与常用经验模式精度基本一致,可为开展大气密度变化规律及应用研究提供数据基础.

ApoD对鸡成肌细胞增殖与分化的调控机制研究

为揭示ApoD对鸡成肌细胞增殖与分化的调控作用,研究在鸡原代成肌细胞中分别过表达和干扰ApoD基因,检测胞内活性氧(ROS)和丙二醛(MDA)含量,同时通过流式细胞术、CCK-8、qRT-PCR及免疫印迹等试验探究其对细胞增殖和分化的影响。结果显示:ApoD降低胞内ROS和MDA含量,促进鸡原代成肌细胞增殖;同时,ApoD下调肌肉萎缩标志基因Atrogin1和MuRF1的表达,上调生肌因子MyoD、MyoG和MyHC的表达,从而促进鸡原代成肌细胞分化。研究结果提示ApoD通过降低胞内ROS含量、降低Atrogin1对MyoD的泛素化降解作用以及MuRF1对MyHC的抑制作用,促进鸡成肌细胞增殖与分化。

A high-contrast coronagraph for direct imaging of Earth-like exoplanets: design and test

A high-contrast coronagraph for direct imaging of an Earth-like exoplanet at the visible band needs a contrast of 10^-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these lim- its. Our test of a high-contrast imaging coronagraph is based on our step-transmission apodized filter. To achieve this goal, we use a liquid crystal array as a phase correc- tor to create a dark hole based on our dedicated algorithm. We have suppressed the diffraction and speckle noise near the point image of a star to a level of 1.68 × 10^-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demon- strates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.

High-contrast coronagraph for ground-based imaging of Jupiter-like planets

We propose a high-contrast coronagraph for direct imaging of young Jupiter-like planets orbiting nearby bright stars. The coronagraph employs a step- transmission filter in which the intensity is apodized with a finite number of steps with identical transmission in each step. It should be installed on a large ground-based telescope equipped with a state-of-the-art adaptive optics system. In this case, contrast ratios around 10-6 should be accessible within 0.1 arcsec of the central star. In recent progress, a coronagraph with a circular apodizing filter has been developed, which can be used for a ground-based telescope with a central obstruction and spider structure. It is shown that ground-based direct imaging of Jupiter-like planets is promising with current technology.

Numerical investigation of slow solitons in Bragg gratings with a hyperbolic tangent apodization

This paper numerically and analytically investigates the formation and propagation motion of optical soliton in the Bragg grating. We choose the fibre Bragg grating with hyperbolic tangent apodization in the middle section in order to obtain slower solitons. Optical fibre soliton but not Bragg grating soliton is used as input pulse in the discussion, which is much more approximate to the light source for the practical purpose. We discuss in detail the effects of the soliton＇s velocity with some parameters in the process of transmission. The results show that by choosing special parameters, one can make the soliton slow-down with a little distortion and energy decay and obtain tunable time-delay on a small scale.

Simulating Ultrasound Reflections Using Rayleigh Integral Method in Complex Biological Media

This paper exploits the Rayleigh integral method to simulate the propagation of transmitted ultrasonic waves and received echoes through various media. Performed simulations study the effect of apodization using different types of windows and the effect of medium properties on the reflections obtained. All estimations are done using the Rayleigh integral method simplified by the Fresnel approximation. Five different interfaces are considered： tissue-bone-tissue, tissue-fat-bone, fat-muscle-bone, air-fat-bone and water-fat-bone. The apodization simulations show that the hamming window is more efficient than the rectangular and triangular windows for obtaining a more consistent beam. In the second set of simulations, reflections are mapped with respect to the depth from which these reflections are generated. It demonstrates that the solid and water media allow for the attainment of echoes from deeper regions as compared to the air medium. Matlab is used as the simulation framework.

APODE汽车冲压件在线检测设备主机结构方案设计

由于传统的汽车冲压件检测中存在着数据误差较大、检测效率低下、数字化集成度不足，质量跟踪不达标等缺陷，当前，对冲压件的检测方式过于落后，效率低下，已经无法跟上工厂对汽车冲压件大批量、高效率的检测需求标准。针对这一问题，本文就APODE汽车冲压件在线检测设备的主机结构方案设计及其特性做了相关阐述。

青苹果的酸酸甜甜——APOD AP628滋味尝鲜

夏天来了,这个炎热的季节里水果成了人们备受亲睐的食品。一枚翠绿的、新鲜的青苹果一定会在短短的时间让你情绪变佳,食欲大增。呵呵,在这个季节,金苹果科技推出了一款青苹果AP628的MP3播放器,外观鲜艳亮丽,同时有8种漂亮的颜色可供选择,相信它在MP3领域起到的作用一定会像夏天的青苹果一样勾起消费者的欲望。具体效果如何,让我们来一起领略它的风采。

Impact of Atmospheric Transmittance and NLTE Correction on Simulation of High Spectral Infrared Atmospheric Sounder onboard FY-3E

With the launch of the first civilian early-morning orbit satellite Fengyun-3E(FY-3E),higher demands are placed on the accuracy of radiative transfer simulations for hyperspectral infrared data.Therefore,several key issues are investigated in the paper.First,the accuracy of the fast atmospheric transmittance model implemented in the Advanced Research and Modeling System(ARMS)has been evaluated with both the line-by-line radiative transfer model(LBLRTM)and the actual satellite observations.The results indicate that the biases are generally less than 0.25 K when compared to the LBLRTM,while below 1.0 K for the majority of the channels when compared to the observations.However,during both comparisons,significant biases are observed in certain channels.The accuracy of Hyperspectral Infrared Atmospheric Sounder-II(HIRAS-II)onboard FY-3E is comparable to,and even superior to that of the Cross-track Infrared Sounder(CrIS)onboard NOAA-20.Furthermore,apodization is a crucial step in the processing of hyperspectral data in that the apodization function is utilized as the instrument channel spectral response function to produce the satellite channel-averaged transmittance.To further explore the difference between the apodized and unapodized simulations,Sinc function is adopted in the fast transmittance model.It is found that the use of Sinc function can make the simulations fit the original satellite observations better.When simulating with apodized observations,the use of Sinc function exhibits larger deviations compared to the Hamming function.Moreover,a correction module is applied to minimize the impact of Non-Local Thermodynamic Equilibrium(NLTE)in the shortwave infrared band.It is verified that the implementation of the NLTE correction model leads to a significant reduction in the bias between the simulation and observation for this band.

腋臭患者大汗腺中ApoD和AR的表达水平与气味强度间的关系

目的:明确大汗腺组织中ApoD和AR的表达水平与腋臭患者散发出气味间的关系,阐明两者在腋臭发病中的作用,为腋臭的临床治疗和干预奠定基础。方法:收集在我院整形外科就诊的腋臭病人腋下皮肤组织标本41例。手术前由3名医生共同判断患者腋下气味强度,按照能在≤1 m、≤3 m、≤5 m距离闻及气味把患者分为轻、中、重三组。随机抽取各组标本组织块进行RT-PCR检测,测定ApoD和AR在大汗腺组织中的含量。结果:根据气味强度判定标准,轻、中和重3组患者人数分别为:7人、11人和23人。按照AB 7500 Real-Time PCR系统分析结果所示ApoD相对表达量的等级与气味强度之间有线性关系(P<0.05),ApoD相对表达量的等级随着气味强度的增加而升高;AR相对表达量的等级与气味强度之间有线性关系(P<0.05),随着气味强度的增加而升高。结论:ApoD和AR的表达量与腋臭气味强度之间有着密切的联系。进一步证实AR可调节大汗腺组织ApoD的表达,为明确腋臭的发病机制提供了理论依据。