利用深度学习对声呐图像进行目标检测是近年来的研究热点,然而声呐图像存在目标尺度分布集中、数据获取难等问题,导致检测效果难以满足需求。针对该问题,提出了一种基于可变尺度先验框的目标检测方法。首先,考虑到声呐图像中目标的尺度...利用深度学习对声呐图像进行目标检测是近年来的研究热点,然而声呐图像存在目标尺度分布集中、数据获取难等问题,导致检测效果难以满足需求。针对该问题,提出了一种基于可变尺度先验框的目标检测方法。首先,考虑到声呐图像中目标的尺度分布具有其特殊性,基于先验统计生成可变尺度先验框。其次,为了解决声呐图像稀缺的难题,采用数据增强的方法对训练集进行扩充。最后,探索了模型的轻量化,通过删减模型的大目标检测层,在不降低模型精度的同时简化模型结构。为了评估算法的有效性,以前视声呐图像为例进行了综合试验,平均精度(mean average precision,mAP)@0.75和mAP@0.5:0.95分别达0.585和0.559,较原Yolov5网络分别提升了5.8%和3.1%,同时每秒10亿次浮点运算次数下降到14.9。结果表明,所提算法具有更高的精度和更轻量化的模型结构。展开更多
为了在鸡基因组上对AMHR2基因进行精确编辑,该研究利用crispr.mit.edu:807网站设计并通过PCR退火拟合获得成对的AMHR2基因靶位点,将靶位点分别整合进pX330-U6-Chimeric_dBsa I-CBh-hSpCas9载体骨架,构建靶向AMHR2基因的成对CRISPR/Cas9...为了在鸡基因组上对AMHR2基因进行精确编辑,该研究利用crispr.mit.edu:807网站设计并通过PCR退火拟合获得成对的AMHR2基因靶位点,将靶位点分别整合进pX330-U6-Chimeric_dBsa I-CBh-hSpCas9载体骨架,构建靶向AMHR2基因的成对CRISPR/Cas9敲除载体。将包含成对靶位点的DNA序列整合进pB-CMV-DsRed-CAG-Chimeric.200 bp repeat.Puro-T2A-GFP载体骨架,构建与敲除载体对应的双荧光报告载体。载体测序鉴定正确后分别共转染HEK293T细胞与鸡DF-1细胞,通过细胞荧光粗略判断CRISPR/Cas9系统是否工作。随后,利用Puromycin对基因编辑阳性的DF-1细胞进行药物筛选富集,提取细胞基因组进行TA克隆,进一步检测CRISPR/Cas9系统的工作效率。结果表明靶向鸡AMHR2基因的CRISPR/Cas9敲除系统构建成功,且成对靶位点敲除系统的工作效率高于单一靶位点敲除系统,CRISPR/Cas9敲除系统在DF-1细胞基因组上对AMHR2基因的敲除效率约为60.0%,并在鸡DF-1细胞基因组上实现了AMHR2基因的精确编辑。展开更多
研究旨在阐明抗缪勒氏管激素(Anti-Müllerian hormone,AMH)在蛋鸡生殖系统中调节卵泡发育和卵泡选择的作用。将40只蛋鸡(29周龄)随机分为4组,2个试验组每天分别注射150 ng和300 ng AMH,注射等体积无菌注射用水组(CON+),不进行处理...研究旨在阐明抗缪勒氏管激素(Anti-Müllerian hormone,AMH)在蛋鸡生殖系统中调节卵泡发育和卵泡选择的作用。将40只蛋鸡(29周龄)随机分为4组,2个试验组每天分别注射150 ng和300 ng AMH,注射等体积无菌注射用水组(CON+),不进行处理组(CON-)。连续处理25 d,每天记录产蛋情况。试验鸡于第26天时处死,取组织标本进行组织学观察。结果显示,注射AMH后蛋鸡的产蛋量和产蛋序列分别表现出下降和推迟的趋势,但影响均不显著;此外,注射AMH可显著降低F1卵泡的颗粒细胞层厚度。体外注射不同浓度的AMH会对蛋鸡的卵巢卵泡发育产生不同的影响。展开更多
Poly (3, 4-ethylenedioxythiophene) (PEDOT), together with its dopes, such as poly (styrene sulfonate) (PSS), has been acknowledged to have a wide range of biomedical applications as an important conducting pol...Poly (3, 4-ethylenedioxythiophene) (PEDOT), together with its dopes, such as poly (styrene sulfonate) (PSS), has been acknowledged to have a wide range of biomedical applications as an important conducting polymer. In this study, gelatin can be polymerized into PEDOT/PSS polymers on indium tin oxide (ITO)-coated glass. PEDOT/PSS/gelatin layer on ITO-coated glass significantly decreases electrochemical impedance spectroscopy (EIS) and increases charge delivery capacity relative to the gelatin layer and bare ITO- coated glass, comparable to the PEDOT/PSS layer on ITO-coated glass. PEDOT/PSS/gelatin layer on ITO- coated glass enhances pheochromocytoma (PC 12) cell affinity, possesses a high biocompatibility and promotes PC 12 cell growth by delivery of electrical stimulation. These results suggest that gelatin can be incorporated into the PEDOT/PSS polymers through electrochemical polymerization and the PEDOT/PSS/gelatin layer on ITO-coated glass possesses high electrochemical and biological activities.展开更多
文摘利用深度学习对声呐图像进行目标检测是近年来的研究热点,然而声呐图像存在目标尺度分布集中、数据获取难等问题,导致检测效果难以满足需求。针对该问题,提出了一种基于可变尺度先验框的目标检测方法。首先,考虑到声呐图像中目标的尺度分布具有其特殊性,基于先验统计生成可变尺度先验框。其次,为了解决声呐图像稀缺的难题,采用数据增强的方法对训练集进行扩充。最后,探索了模型的轻量化,通过删减模型的大目标检测层,在不降低模型精度的同时简化模型结构。为了评估算法的有效性,以前视声呐图像为例进行了综合试验,平均精度(mean average precision,mAP)@0.75和mAP@0.5:0.95分别达0.585和0.559,较原Yolov5网络分别提升了5.8%和3.1%,同时每秒10亿次浮点运算次数下降到14.9。结果表明,所提算法具有更高的精度和更轻量化的模型结构。
文摘为了在鸡基因组上对AMHR2基因进行精确编辑,该研究利用crispr.mit.edu:807网站设计并通过PCR退火拟合获得成对的AMHR2基因靶位点,将靶位点分别整合进pX330-U6-Chimeric_dBsa I-CBh-hSpCas9载体骨架,构建靶向AMHR2基因的成对CRISPR/Cas9敲除载体。将包含成对靶位点的DNA序列整合进pB-CMV-DsRed-CAG-Chimeric.200 bp repeat.Puro-T2A-GFP载体骨架,构建与敲除载体对应的双荧光报告载体。载体测序鉴定正确后分别共转染HEK293T细胞与鸡DF-1细胞,通过细胞荧光粗略判断CRISPR/Cas9系统是否工作。随后,利用Puromycin对基因编辑阳性的DF-1细胞进行药物筛选富集,提取细胞基因组进行TA克隆,进一步检测CRISPR/Cas9系统的工作效率。结果表明靶向鸡AMHR2基因的CRISPR/Cas9敲除系统构建成功,且成对靶位点敲除系统的工作效率高于单一靶位点敲除系统,CRISPR/Cas9敲除系统在DF-1细胞基因组上对AMHR2基因的敲除效率约为60.0%,并在鸡DF-1细胞基因组上实现了AMHR2基因的精确编辑。
基金Funded by National Natural Science Foundation of China(Nos.11179015,51173108)Innovation Program of Shanghai Municipal Education Commission(No.12ZZ143)
文摘Poly (3, 4-ethylenedioxythiophene) (PEDOT), together with its dopes, such as poly (styrene sulfonate) (PSS), has been acknowledged to have a wide range of biomedical applications as an important conducting polymer. In this study, gelatin can be polymerized into PEDOT/PSS polymers on indium tin oxide (ITO)-coated glass. PEDOT/PSS/gelatin layer on ITO-coated glass significantly decreases electrochemical impedance spectroscopy (EIS) and increases charge delivery capacity relative to the gelatin layer and bare ITO- coated glass, comparable to the PEDOT/PSS layer on ITO-coated glass. PEDOT/PSS/gelatin layer on ITO- coated glass enhances pheochromocytoma (PC 12) cell affinity, possesses a high biocompatibility and promotes PC 12 cell growth by delivery of electrical stimulation. These results suggest that gelatin can be incorporated into the PEDOT/PSS polymers through electrochemical polymerization and the PEDOT/PSS/gelatin layer on ITO-coated glass possesses high electrochemical and biological activities.