Quality assessment for color correction-based stitched images via bi-directional matching

With the deepening of social information, the panoramic image has drawn a significant interest of viewers and researchers as it can provide a very wide field of view (FoV). Since panoramic images are usually obtained by capturing images with the overlapping regions and then stitching them together, image stitching plays an important role in generating panoramic images. In order to effectively evaluate the quality of stitched images, a novel quality assessment method based on bi-directional matching is proposed for stitched images. Specifically, dense correspondences between the testing and benchmark stitched images are first established by bi-directional SIFT-flow matching. Then, color-aware, geometric-aware and structure-aware features are respectively extracted and fused via support vector regression (SVR) to obtain the final quality score. Experiments on our newly constructed database and ISIQA database demonstrate that the proposed method can achieve comparable performance compared with the conventional blind quality metrics and the quality metrics specially designed for stitched images.     

基于染色体畸变的细胞存活模型研究

为评估质子和重离子的辐射生物效应，建立了基于染色体畸变的细胞存活机理模型。开发了纳剂量生物物理蒙特卡罗模拟程序（NASIC）的DNA损伤修复模块，用于模拟不同射线类型、不同传能线密度（LET）辐射所致细胞核内染色体畸变产额。在分析辐射所致染色体畸变产额规律的基础上，建立了基于染色体畸变的细胞存活机理模型，并根据细胞存活实验数据拟合模型参数。以V79细胞为例，对于X射线和不同LET的质子，细胞存活分数的模型计算值与实验数据符合得很好，相关系数为0.985 3。采用⁴He离子的实验数据对模型及参数进行了验证，模型计算值与实验数据的相关系数为0.931 1。可见，模型能较好地区分不同射线类型、不同LET辐射在细胞致死效应上的差异。     

光学像差图像随机波前编码混合成像

研究了一种采用随机相位板消除光学像差的波前编码和数字图像处理混合成像方法.用激光散斑干涉法制作随机相位板,放置在系统成像面之前的光路中,光学像差图像被转变为随机编码中间像,使光学系统固定像差淹没在随机编码中受到削弱.建立了基于频域梯度优化的盲反卷积解码算法,用于解码中间像为无像差图像,由于采用频域共轭梯度优化,提高了解...     

Cytotoxic effect of sodium arsenite on Nile tilapia (Oreochromis niloticus) in vivo

This study showed the relevance of using chromosomal aberration (CA) as potential indicators of sodium arsenite (SA; NaAsO₂) cytotoxicity. The study investigated cytotoxic potential of SA in Oreochromis niloticus using CA assessment. The fish were exposed to four different concentrations of SA (5, 10, 20 and 40 mg/L) for 24 hours in comparison to a control group. The As concentrations in the samples were analysed by inductively coupled plasma atomic emission spectrometry. The differences in As concentrations in the water and O. niloticus samples between the control and experimental groups were significant (p<0.05), whereas the within experimental group differences were not significant. The cytotoxic assessment of SA in O. niloticus revealed five types of CAs, including single chromatid gaps (SCG), single chromatid break (SCB), centric gap (CG), fragmentation (F) and deletion (D). The most common CA in the O. niloticus samples was SCG. A total of 2.33, 10.67, 18.67, 18.00 and 23.67% of the cells in the control and experimental groups exhibited CAs. The numbers of CAs and cells with CAs from the control and experimental groups of fish were significantly different (p<0.05); additionally, the fish exposed to 5 and 40 mg/L showed significant within experimental group differences (p<0.05).     

即食调味鲅鱼产品开发及杀菌条件对其品质的影响

为开发一款即食调味鲅鱼产品,通过正交优化确定调味鲅鱼的最佳调味料配方,同时探究不同杀菌条件对产品品质的影响。结果表明:最佳调味配方为白砂糖添加量1 g,辣椒粉添加量2 g,麻椒油添加量2 g,五香粉添加量1.5 g;杀菌条件对调味鲅鱼质构和色差中的硬度、胶着度、咀嚼度和L值影响显著,当杀菌条件为115℃、20 min时,鲅鱼硬度为1405.33±45.30,L值为58.52±0.41,综合感官评分最高。结合菌落总数、感官评价、质构和色差综合分析,最佳杀菌条件为:115℃、20 min。     

Genotoxicity tests of poly(styrene-co-maleic anhydride)-coated silver nanoparticles in vivo and in vitro

Nanosilver is thought to hold potential for use in medical materials. The safety of newly developed poly(styrene-co-maleic anhydride)-coated silver nanoparticles (SMA-AgNPs) requires investigation. In this study, three in vitro and in vivo experiments for investigating genetic toxicity–the Ames test, a micronucleus assay, and a chromosome aberration test–were conducted. Results from the Ames testing showed SMA-AgNPs to have a negative effect, either with or without S9 metabolism. In addition, SMA-AgNPs increased the number of reticulocytes and micronuclei in reticulocytes at 48 and 72 h after treatment. Indeed, SMA-AgNPs induced significant changes in the chromosomal aberration rate in CHO-K1 (Chinese hamster ovary cell clone K1) cells. In conclusion, SMA-AgNPs did cause DNA damage in terms of chromosomal aberration and may have a potential genotoxic effect in certain applications.     

An ocular wavefront sensor based on binary phase element: design and analysis

A modal wavefront sensor for ocular aberrations exhibits two main advantages compared to a conventional Shack–Hartmann sensor. As the wavefront is detected in the Fourier plane, the method is robust against local loss of information (e.g. local opacity of ocular lens as in the case of cataract), and is not dependent on the spatial distribution of wavefront sampling. We have proposed a novel method of wavefront sensing for ocular aberrations that directly detects the strengths of Zernike aberrations. A multiplexed Fourier computer-generated hologram has been designed as the binary phase element (BPE) for the detection of second-order and higher-order ocular aberrations (HOAs). The BPE design has been validated by comparing the simulated far-field pattern with the experimental results obtained by displaying it on a spatial light modulator. Simulation results have demonstrated the simultaneous wavefront detection with an accuracy better that ～λ/30 for a measurement range of ±2.1λ with reduced cross-talk. Sensor performance is validated by performing a numerical experiment using the City data set for test waves containing second-order and HOAs and measurement errors of 0.065?µm peak-to-valley (PV) and 0.08?µm (PV) have been obtained, respectively.     

Genotoxicity of recycling electronic waste in Idhna,Hebron District,Palestine

Most Electronic waste (e-waste) ends up in landfills while some is recycled. A major site for e-waste recycling in Palestine is the village of Idhna in the Hebron District and most of this waste originates from Israel. The objective of this study was to evaluate the effects of e-waste on human DNA damage and chromosome breaks. The test sample was 46 non-smoker individuals with direct exposure to e-waste, either employed in the workshops or resident in Idhna. Genotoxicity data were compared with a control sample of sixteen unexposed individuals from Bethlehem and Al-Aizariya (Bethany). DNA damage was evaluated using the Comet assay while chromosome aberrations were tested by using conventional cytogenetic techniques. We noted an average of 4.83 aberration/cell/subject in test samples while in controls the average was 0.75. Chromosome aberration frequency was statistically different between exposed and control samples for total aberrations, for chromatid and chromosome breaks, and for formation of rings but not for dicenterics and tetraploidy. The Comet assay likewise showed that there was significant difference between exposed and control samples for DNA damage (p < 0.05). We therefore recommend measures to mitigate the health impact of e-waste recycling.     

基于复用计算全息元件的多阶模式偏置波前传感器

提出利用复用计算全息元件实现多阶模式同步的偏置模式波前传感器。对基于复用计算全息元件的多阶模式偏置波前传感器进行了理论分析。为了实现复用计算全息元件,分别编码设计了包含4阶,10阶和20阶Zernike像差模式的复用计算全息图,讨论了复用计算全息图设计中几个关键问题。数值模拟研究了复用计算全息图对单阶和多阶像差模式的探测性能。结果表明,在一定探测范围内,传感器能够响应与全息图内预先记录像差模式相同的待测像差模式,且每一个模式的灵敏度都不同。全息图内记录模式数较少时,单阶模式探测的灵敏度较大;记录模式数越多,模式之间擦除效应越严重,单阶和多阶模式灵敏度都受到一定影响。     

导航卫星激光后向反射器研究

鉴于设计Galileo导航卫星上激光后向反射器的需要,采用理论计算和实验验证的方法对角反射器的光行差补偿设计和远场衍射光强分布进行了研究.对不同直角偏差、是否镀反射膜的角反射器远场衍射光强分布给出了计算和试验结果.研究结果表明:理论计算与实验结果是完全一致的;对类似Galileo卫星的角反射器设计采用光行差角补偿是必要...