芝麻过敏原Ses i 2核酸适体的筛选与鉴定研究

芝麻是八大类食物过敏原之一,快速准确识别芝麻过敏原对预防其过敏有重要意义。核酸适配体可以高效识别靶标过敏原,在过敏原检测中有良好的应用前景。为了获得芝麻主要过敏原Ses i 2的特异性核酸适体,本研究以Ses i 2为靶标,通过磁珠筛选法(磁珠-SELEX)开展10轮筛选,经由高通量测序获得6条候补序列(S1~S6),并进行家族性、同源性分析及二级结构预测。结果表明,6条候选核酸适体的重复率可达46.38%,其自由能在-9.02到-2.47 kcal·moL^(-1)之间,根据自由能能量稳定原则,S1和S5吉布斯自由能最低最稳定,分别为-6.70和-9.02 kcal·moL^(-1)。利用ELISA试验进行亲和力测试,结果表明核酸适体S1和S2的亲和能力较强,S1:KD=67.02 nmol·L^(-1),R2=0.925 8,S2:KD=97.65 nmol·L^(-1),R2=0.795 1。核酸适体S1与过敏原Ses i 2的结合力和其他过敏原蛋白相比有显著差异,可视为具有特异性。本研究最终获得一条兼具良好亲和力和特异性的核酸适体S1,为芝麻过敏原快速检测提供了技术支撑。

S空位及非金属掺杂单层Bi_(2)S_(2)Se的第一性原理研究

Bi_(2)S_(2)Se是一种新兴的具有优异光电性能的材料,因此受到了广泛的关注.本研究采用第一性原理方法和开源程序,研究了本征单层Bi_(2)S_(2)Se以及掺杂非金属元素X(X=P,Cl,Br和I)和S空位的体系的电子结构和光学特性.计算结果表明,改性后出现了晶格缺陷.含S空位和P、Cl、Br掺杂体系的带隙减少,而I掺杂体系的带隙增加.同时,含S空位和Cl、Br、I掺杂体系的费米能级穿过导带底,而P掺杂体系的费米能级穿过价带顶.所有改性体系在费米能级附近都出现了缺陷能级或杂质能级,表现出较高的可见光吸收能力和散射能力,改性体系的对可见光的吸收能力和散射能力有所增加.

基于ASP-SERes2Net的说话人识别算法

为提升说话人识别的特征提取能力,解决在噪声环境下识别率低的问题,提出一种基于残差网络的说话人识别算法——ASP-SERes2Net。首先,采用梅尔语谱图作为神经网络的输入;其次,改进Res2Net网络的残差块,并且在每个残差块后引入压缩激活(squeeze-and-excitation,SE)注意力模块;然后,用注意力统计池化(attention statistics pooling,ASP)代替原来的平均池化;最后,采用附加角裕度的Softmax(additive angular margin Softmax,AAM-Softmax)对说话人身份进行分类。通过实验,将ASP-SERes2Net算法与时延神经网络(time delay neural network,TDNN)、ResNet34和Res2Net进行对比,ASP-SERes2Net算法的最小检测代价函数(minimum detection cost function,MinDCF)值为0.0401,等误率(equal error rate,EER)为0.52%,明显优于其他3个模型。结果表明,ASP-SERes2Net算法性能更优,适合应用于噪声环境下的说话人识别。

基于CNN‑LSTM‑SE的心电图分类算法研究

心血管疾病是我国死亡率较高的疾病之一,通过观察心电图来判断心电信号是否出现异常能够对心血管疾病进行预防和筛查。由于心电图数据规模大且繁杂,临床医护人员在心电图筛查时,工作负担大且容易出现误诊或漏诊的情况。为了提高心电图的筛查效率、减少医护人员的压力,提出了一种基于卷积神经网络、长短期记忆神经网络和SE网络的心电图分类算法模型(CNN-LSTM-SE),该模型将心电图分成5种不同的类别。主要研究内容包括:选用MIT-BIH心律失常数据集作为心电信号的数据来源,使用巴特沃斯带通滤波器对心电信号进行去噪处理,通过Z-score方法对心电信号进行标准化处理,利用独热编码方法对心电信号标签进行编码,最后使用处理后的心电数据对所提算法模型进行训练和测试。实验结果表明:所提模型相较于其它模型,能够有效提高心电图分类的准确性,在实验数据集上的分类准确率达到99.1%。

重金属地质高背景区土壤Se的地球化学特征及富Se耕地综合评价

为了合理保护和利用富Se耕地资源,为重金属地质高背景区富Se农产品的安全开发提供科学依据,以重庆市黔江区白土乡为例,采集74份耕地土壤(0~20 cm)及水稻籽实样品,分析稻谷及土壤中Se和重金属(Cd、Hg、Pb、As、Cr、Cu、Zn和Ni)含量,同时分析土壤中养分元素及氧化物含量,研究土壤及稻谷中各元素的地球化学特征,并开展富Se耕地综合评价。结果显示,研究区土壤环境综合质量等级以三等(轻度污染)和四等(中度污染)为主,面积占比分别为41.65%和50.71%,污染因子为Cd。土壤Se平均含量为0.91 mg·kg^(-1),含量介于0.4~3.0 mg·kg^(-1)之间的点位占比为97.29%,土壤Se资源丰富。研究区耕地土壤总体养分条件良好,但部分区域存在单元素缺乏问题,以K缺乏最为显著。耕地土壤重金属和Se含量主要与灰岩、炭质页岩(夹煤线)的风化成土有关。此外,农业活动会造成耕地土壤Cd和As的输入。研究区糙米富Se率为100%,糙米Cd超标率为7.4%,土壤pH值是影响稻谷吸收土壤Cd和Se的主控因素,中碱性条件有利于水稻富集Se而抑制其对Cd的吸收。研究区富Se耕地综合等级以二等为主,面积占比为95.68%,适宜开展富Se资源开发利用。可根据各耕地地块单项指标得分情况,通过养分元素补充、土壤酸碱度调节等措施,趋利避害利用土壤富Se资源,对部分不适宜开展富Se资源开发利用的耕地,可进行种植结构调整。

基于改进SE-Net和深度可分离残差的高光谱图像分类

针对目前常见的用于高光谱图像分类的卷积神经网络参数数量多,训练时间长,对样本数量依赖性大的问题,提出一种适用于有限训练样本条件下基于改进压缩激活网络和深度可分离残差的分类网络MDSR&SE-Net.首先使用主成分分析对原始高光谱图像进行通道降维,然后通过三维卷积神经网络连接多特征残差结构,同时嵌入改进的SE模块提取高光谱图像的空间和光谱细节特征,最后将提取到的特征数据输入Softmax分类器激活分类.为了使网络更加轻量,通过在残差结构中使用深度可分离卷积和引入全局平均池化减少参数数量.实验结果显示,使用有限训练样本在三种常见高光谱数据集上总体分类精度均达到99%以上.

Comparative study of the effects of three semen preparation media on semen analysis,DNA damage and protamine deficiency,and the correlation between DNA integrity and sperm parameters

Semen samples collected from 28 male partners of infertile couples were divided into three equal aliquots and prepared with three selected media,such as PureSperm （Nidacon,Gothenburg,Sweden）,Sil-Select Plus^TM （Fertipro,Beemem,Belgium） and SpermGrad^TM（Vitrolife,Gothenburg,Sweden）. The differences in mean percentages of semen parameters were assessed by repeated measures analysis. Correlations of sperm DNA damage,as measured by terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL） assay,and of protamine deficiency,as measured by chromomycin A3 （CMA3） staining with sperm parameters,were determined by Pearson＇s correlation. After preparation with all three media,sperm concentrations decreased （P〈0.05） while percentages of sperm with normal morphology increased （P〈0.05）. Percentages of sperm motility,rapid motility and progressive motile concentration （PMC） increased （P〈0.05） for each ofthese parameters,PureSperm preparation gave the best results （P〈0.05）. The percentage of DNA damage decreased in the PureSperm and Sil-Select Plus preparations （17.9% and 31.3%,respectively,P〈0.05） and increased in the SpermGrad preparation （56.3%,P〈0.05）. Protamine deficiency also decreased in all three kinds of media,59.3%,47.7% and 40.3% for PureSperm,Sil-Select Plus and SpermGrad preparations,respectively （P〈0.05）. The percentage of DNA-damaged sperm was negatively correlated with the percentages of sperm motility,rapid motility and PMC,but was positively correlated with static motility （P〈0.05）. This comparative study and correlation analysis revealed that PureSperm preparation yielded sperm with the best motility and the lowest percentage of protamine deficiency. The Sil-Select Plus preparation yielded sperm with the lowest amount of DNA damage. The SpermGrad preparation had a high percentage of sperm with normal morphology,but also had the highest percentage of sperm with DNA damage. Sperm DNA damage was correlated with percentages of sperm motility,rapid motility,static motility and PMC.

基于SE注意力CycleGAN的蓝印花布单纹样自动生成

根据蓝印花布纹样的风格特征,文章提出一种端到端的蓝印花布纹样自动生成方法,实现简笔画图像向蓝印花布单纹样的自动迁移。针对蓝印花布的抽象风格和小数据集问题,重新构造CycleGAN生成网络中的编码器和解码器,使用SE(squeeze and excitation)注意力模块和残差模块与原始的卷积模块串联,提高特征提取能力和网络学习能力。同时减少生成网络中转换器的残差块层数,降低过拟合。实验结果表明,基于SE注意力CycleGAN网络方法自动生成的蓝印花布新纹样主观性上更贴合原始风格,与原图更加接近,有助于蓝印花布的数字化传承和创新。

The Protamine-like DNA-binding Protein P6.9 Epigenetically Up-regulates Autographa californica Multiple Nucleopolyhedrovirus Gene Transcription in the Late Infection Phase

Protamines are a group of highly basic proteins first discovered in spermatozoon that allow for denser packaging of DNA than histones and will result in down-regulation of gene transcription^l~. It is well recognized that the Autographa californica multicapsid nucleopolyhedrovirus （AcMNPV） encodes P6.9, a protamine-like protein that forms the viral subnucleosome through binding to the viral genome[29]. Previous research demonstrates that P6.9 is essential for viral nucleocapsid assembly, while it has no influence on viral genome replication1311. In the present study, the role of P6.9 in viral gene transcription regulation is characterized. In contrast to protamines or other protamine-like proteins that usually down-regulate gene transcription, P6.9 appears to up-regulate viral gene transcription at 12-24 hours post infection （hpi）, whereas it is non-essential for the basal level of viral gene transcription. Fluorescence microscopy reveals the P6.9＇s co-localization with DNA is temporally and spatially synchronized with P6.9＇s impact on viral gene transcription, indicating the P6.9-DNA association contributes to transcription regulation. Chromatin fractionation assay further reveals an unexpected co-existence of P6.9 and host RNA polymerase II in the same transcriptionally active chromatin fraction at 24 hpi, which may probably contribute to viral gene transcription up-regulation in the late infection phase.

Studies on Expression of P1 Protamine Gene in Rat and Mouse Testis

Protamine is a kind small, basic protein rich in arginine residues and found to be complexed with DNA in spermatozoa. We have cloned a 150 bp cDNA encoding the rat protamine (rP) by RT PCR technique. Dig labelled cDNA for rP was used for Northern blot analysis to study the expression of P1 protamine gene in rat and mouse. P1 protamine mRNA was detected only in rat testis, no hybridization signals were detected in rat brain and lever. In addition, the presence of P1 protamine mRNA was detected not only in rat testis, but also in mouse testis. Dig labelled cDNA for mouse protamine 1 (mP1) was used to study the expression of mP1 gene during the process of sexual maturation of mouse. 7～8 d after birth, no mP1 mRNA could be detected. At d 24～26, mP1 mRNA was detectable migrating as a homogeneous band at 580 nucleotides, whereas in sexually mature animals, a heterogeneous mixture of RNAs ranging from 450～580 bases in length was observed. Histological studies revealed that in the testis of 7～8 day old mouse, spermatogenesis has developed to the spermatocyte stage, whereas round spermatids (Rs) were present in the testis of the mice with 24～26 d age and elongating spermatids (Es) were present in the testis of sexually mature animals. Electrophoresis of total nuclear basic proteins (TNBP) revealed that the Rs could possess the somatic histones, while Es was found to have protamine and less histone. These results indicate that the P1 protamine gene is tissues specifically expressed and the P1 protamine is showing to be conservative in evolution. During the process of sexual maturation, along with morphological changes, mP1 gene was transcribed in Rs and translated in Es. The mechanism of protamine gene expression was discussed.

Human protamines and the developing spermatid: their structure, function, expression and relationshipwith male infertility

<abstract>During spermiogenesis, the protamine proteins play an integral role in spermatid chromatin compaction. Recent research has focused on many facets of protamine biology, including protamine gene and protein structure/ function relationships, mechanisms of protamine expression regulation and involvement of the protamines in male fertility. In this paper, we review our current understanding of the structure and function of the protamine-1 (P1) and protamine-2 (P2) proteins and genes, the expression and regulation of these genes and the relationship between the protamines and male fertility. In addition, we offer a brief outlook on future investigation into protamine proteins.

基于VGG16-DenseNet集成模型的烤烟智能分级

为实现烤烟烟叶等级快速、准确的智能化识别,本研究基于手机拍摄的不同品种烤烟烟叶正、反面图像,构建了VGG16与DenseNet组合的新网络模型VGG16-Dense,并应用手机拍摄的翠碧1号、云烟87烤烟烟叶6个等级正反面图片,总共24类,验证该模型的有效性,同时与5个网络模型DenseNet121、ResNet50、AlexNet、VGG16和GoogLeNet进行比较。研究表明:VGG16-Dense网络模型在验证集的各评估指标(准确率、精确率、召回率、F1分数和平均损失值)均达到优秀值,在测试集的各评估指标较其他模型是最优的,准确率为92.71%,精确率为93.07%,召回率为92.71%,F1分数为92.72%,平均损失值为0.22,有较好的泛化能力,错判较少。VGG16-Dense网络模型能同时智能判别烤烟烟叶等级及其正反面,甄别不同品种,这为初级烤烟收购中的定级实现智能化提供理论指导。

基于DEMATEL和SE-DEA的民航监察员培训效能评价

为优化培训模式,提高监察员的安全监管能力,降低民航各种不安全事件发生的概率,以“岗位胜任能力导向”为核心的培训模式逐步形成。首先基于“一个素质,三个能力”构建初始岗位胜任力模型,然后结合SPSS和AMOS进行指标筛选和模型验证,利用DEMATEL法探究各指标之间的影响关系并改进权重,最后运用SE-DEA法检验目前的培训课程设置是否合理并进行评价。结果表明:构建的岗位胜任力共15项指标,具有良好的效度和信度;政治素质和管理能力对法治能力和业务能力的影响更大,对胜任力模型影响最大的是业务能力;经过培训,75%的监察员的岗位能力都得到有效提升,达到强化基层安全能力建设的预期,同时说明目前的培训课程设置仍需进一步改进。

SE(3)描述的多刚体系统约束违约问题研究

多刚体系统动力学的指标-1微分代数方程组仅包含加速度级别约束方程,未考虑位移和速度约束方程.数值积分过程中位移和速度约束违约逐渐增加,导致计算结果精度下降,需引入约束稳定方法减小约束违约.首先根据Hamilton变分原理,建立了SE(3)描述的多刚体系统动力学模型.其次给出4种约束稳定方法在SE(3)上形式:Baumgarte方法、罚函数方法、增广拉格朗日方法和约束违约增强稳定方法.相较于传统多刚体系统动力学建模,基于SE(3)的动力学建模可描述转动对平动的耦合效应,能更精确地模拟系统的动力学行为,可提升约束稳定方法的性能.在SE(3)框架下,将4种约束稳定方法与RKMK(Runge-Kutta Munthe-Kass)数值方法结合,对含位移约束和速度约束的动力学方程进行求解.最后通过两个动力学算例:含球铰的空间双球摆算例以及含圆柱铰的曲柄滑块机构算例,分别给出了4种约束稳定方法在SE(3)上对动力学系统的位移和速度约束违约的修正对比结果,并分析了系统能量的变化图.结果表明:SE(3)框架下,4种约束稳定方法结合RKMK算法均表现出良好的保结构和保能量性质,其中SE(3)上增广拉格朗日方法所得位移和速度约束违约较小,总能量保持情况更好;SE(3)上Baumgarte方法能更好地平衡系统计算效率和精度.

Harmony SE在民用飞机设计中的应用

随着民用飞机技术精细化和产品复杂性的提高,民用飞机设计已从传统的基于文档的系统工程转变为基于模型的系统工程,系统表达也从以文档为中心转变为以模型为中心。为进一步提高民用飞机设计中系统建模的模型质量与正确性,进而缩短设计的开发周期与成本,探究以模型驱动及验证为主导的系统工程方法在民用飞机设计领域的适用性,建立民用飞机设计的系统工程框架,用以支持民用飞机的可靠设计与高效交付。以Harmony SE建模方法为切入点,介绍其工作流程和建模思想;分析民用飞机在系统工程实践中出现的突出问题,说明Harmony SE方法在民用飞机系统工程领域的适用性,建立民用飞机设计的系统工程实践体系;以油箱增压组件为研究对象,应用实践体系开展组件级系统工程实践。结果表明,文中所提出的民用飞机设计系统工程体系和方法能够正确合理地分配设计需求并建立完整的系统模型,有助于提升现阶段民用飞机设计的效率与准确性。

不同维度Ag_(2)Se构筑柔性热电薄膜的性能优化与器件集成研究

Ag_(2)Se热电薄膜及器件因其窄带隙半导体特性在室温下显示出良好的热电性能,成为近年来可穿戴热电能源转换领域的研究热点。常见的Ag_(2)Se薄膜多由纳米颗粒堆积构筑而成,纳米材料维度对堆积网络的热电传输特性具有重要影响。本研究采用溶剂热法和模板法分别制备了不同维度的Ag_(2)Se纳米材料,通过喷涂工艺结合高温热处理,在聚酰亚胺基底上构筑了柔性Ag_(2)Se热电薄膜,系统研究了Ag_(2)Se纳米材料维度对薄膜微观结构和热电性能的影响。与一维纳米线结构相比,零维Ag_(2)Se纳米颗粒构筑的热电薄膜具有更优的导电网络和热电性能,薄膜的室温功率因子可达199.6μW·m^(-1)·K^(-2),而在375 K时功率因子为257.9μW·m^(-1)·K^(-2),表现出良好的热电性能。基于性能优异的Ag_(2)Se薄膜,进一步设计集成了具有四条热电臂的柔性热电器件。该器件具有良好的机械柔性和输出性能,以20 mm为弯曲半径,在弯曲循环1000次后,内阻仅增加了8.2%;在30 K的温差下,器件开路电压可达9.1 mV,最大输出功率达43.7 nW。本研究为制备柔性Ag_(2)Se热电薄膜材料与器件提供了新的思路和方向。

基于TEE和SE的移动平台双离线匿名支付方案

近年来,中央银行数字货币(CBDC)受到全球多个国家和地区的高度关注.双离线交易作为CBDC的可选属性,在无网络连接的情况下进行支付,被认为具有较大的实用价值.面向CBDC的双离线匿名支付场景,基于可信执行环境(TEE)和安全单元(SE)技术,提出了一种专为移动平台设计的高效双离线匿名支付方案(dual offline anonymous E-payment for mobile devices,OAPM).OAPM适用于资源受限的移动设备,允许移动付款者在不联网状态下安全地向收款者支付数字货币,且不向收款者及商业银行泄露个人隐私信息,付款者的支付行为也不会被链接,同时允许收款者设备处于离线状态,监管机构(如中央银行)在必要情况下能够识别匿名付款者的真实身份.该方案满足数字货币交易的多项重要属性,包括正确性、不可链接性、可追踪性、不可陷害性、机密性、真实性、防双花性以及可控匿名性等.实现了原型系统,并对可能的参数进行了评估.安全性分析和实验结果表明,该方案从安全性和效率两方面均能满足移动用户CBDC双离线交易的实际需求.

基于SE-RetinaNet的面向玻璃面板的小尺寸低显著性缺陷检测

玻璃面板中的缺陷具有低显著、尺寸小、形态多样、数量少等特点,现有先进目标检测算法难以胜任玻璃面板的质检任务。基于此,提出了SE-RetinaNet—一种面向玻璃面板的小尺寸低显著性的缺陷检测算法。该算法在特征金字塔的顶层和底层引入了SE注意力机制和自注意力机制,增强网络对底层小尺寸特征的提取能力并强化顶层网络捕捉特征的长距离依赖关系的能力,同时在网络末端引入定位子网络SE-Regression,通过结合残差块和Inception模块的优点加强了定位的准确度同时防止网络退化。实验结果表明,所提算法能有效检测玻璃面板中各种尺寸的低显著性缺陷,其检测性能优于现有经典目标检测的算法,能够在玻璃面板缺陷检测问题上发挥较好的性能。

Studies on P_1, P_2 Protamine mRNA in Sperms of Human,Rat and Mouse

ve To investigate the existence of the protamine mRNA in sperms of human, rat and mouse

High-efficiency sodium storage of Co_(0.85)Se/WSe_(2) encapsulated in N-doped carbon polyhedron via vacancy and heterojunction engineering

With the advantage of fast charge transfer,heterojunction engineering is identified as a viable method to reinforce the anodes'sodium storage performance.Also,vacancies can effectively strengthen the Na+adsorption ability and provide extra active sites for Na+adsorption.However,their synchronous engineering is rarely reported.Herein,a hybrid of Co_(0.85)Se/WSe_(2) heterostructure with Se vacancies and N-doped carbon polyhedron(CoWSe/NCP)has been fabricated for the first time via a hydrothermal and subsequent selenization strategy.Spherical aberration-corrected transmission electron microscopy confirms the phase interface of the Co_(0.85)Se/WSe_(2) heterostructure and the existence of Se vacancies.Density functional theory simulations reveal the accelerated charge transfer and enhanced Na+adsorption ability,which are contributed by the Co_(0.85)Se/WSe_(2) heterostructure and Se vacancies,respectively.As expected,the CoWSe/NCP anode in sodium-ion battery achieves outstanding rate capability(339.6 mAh g^(−1) at 20 A g^(−1)),outperforming almost all Co/W-based selenides.