光学显微镜的介绍
光学显微镜是一种被研究人员在许多领域使用，用来放大观察样品的仪器，可将样品放大到原来大小的1000倍。最简单的光学显微镜包含一个用来放大样品的干净镜头和一个照射样品的光源。但大多数光学显微镜都要更复杂，在显微镜内部和其物镜目镜里，还包含了很多严格控制了尺寸大小的高精度镜头。本短片将描述光学显微镜的主要组件，并详细讲解它们的应用和功能。还会介绍放大、聚焦以及分辨率这些基本原理。基本的光学显微镜操作，要先将光源照射在样品上，并保证光源的强度、方向及形状合适，这样才能产生最佳质量的图像。然后需要将样品合适地放大并聚焦，来观察感兴趣的区域。光学显微镜有很多实际的应用，包括观察染色或者未染色的细胞或组织，仔细研究样品的微小细节，甚至可以在手术过程中放大感兴趣的区域以帮助在微米级别上的复杂操作。
制备组织学样品用于光学显微镜技术
组织学是指对细胞和组织的研究，它通常需要借助于光学显微镜。根据样品本身属性如大小，硬度以及处理后使用的染色技术和下游应用的不同，制备组织学样品的过程也会有很大不同。如本视频中介绍的，样品的制备通常是从固定步骤开始，用以防止濒临死亡细胞所释放出的酶对样品的降解。固定后，样品会被置于包埋试剂来使样品完全被支撑起来。最常用的是石蜡，但是其他的一些试剂，例如含甘油的冷冻试剂和琼脂也可以在切片的时候用于包埋样品。然后在切片机或其他切片仪器中将样品切割成厚度为几微米到几毫米的薄片。切片之后，薄片会被固定在载玻片上，根据需要进行染色以获得特定的标记，而后在显微镜下成像。
CellSearch检测CTC--陈巍学基因（30）
欢迎来到【陈巍学基因】,我们这个节目，主要是为大家介绍基因组学，和临床分子诊断的最新技术进展。
今天，会和大家谈一下Jassen公司（强生公司）出品的CellSearch系统。它的主要应用是：检测循环肿瘤细胞，并对癌症给出预后信息。以下是课程内容概括：
1.什么是循环肿瘤细胞(CTC)及其“液体活检”的难点。
2. CellSearch系统的检测原理：（1）用微磁珠对CTC细胞进行富集；（2）用针对DNA的荧光染色剂“DAPI”进行染色，以排除红细胞；（3）区分白细胞和CTC细胞。
3.CellSearch系统实际操作的演示。
4.CTC检测，在癌症诊疗方面所起到的作用。
综上所述：CellSearch系统，是第一个标准化的、半自动化的，循环肿瘤细胞检测系统。它通过快速、精确地确定血液样本中的CTC细胞数量。可以帮助医生在整个治疗过程当中，提供准确的预后评估手段。
化学糖生物学 - Carolyn Bertozzi P1
本视频由科普中国和生物医学大讲堂出品
Carolyn Bertozzi (UC Berkeley) Part 1: Chemical Glycobiology
Part 1 A large part of an organism's complexity is not encoded by its genome but results from post-translational modification. Glycosylation, or the addition of sugar molecules to a protein is an example of such a modification. These sugars, or glycans, are often complex, branched molecules specific to particular cells. Cell surface glycans determine human blood types, allow viral infections and play a key role in tissue inflammation. See more at http://www.ibioseminars.org
控制声乐学习行为的大脑通路 - Erich Jarvis P1
本视频由科普中国和生物医学大讲堂出品
Erich Jarvis (Duke/HHMI) Part 1: Convergent behavior and brain pathways
In Part 1, Jarvis explains that vocal learning is the ability to hear a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (parrots, hummingbirds and songbirds) are capable of vocal learning. Jarvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and parrots each have pathways in specific areas of the brain that are not found in non-vocal learning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal learning monkeys.
In Part 2, Jarvis proposes a mechanism by which vocal learning may have evolved. He suggests that the brain areas that control vocal learning are the result of a duplication of a pre-existing neural circuit that controls motor movement. A similar duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In Jarvis' third talk, he demonstrates that the brain pathways necessary for vocal learning are associated with the expression of particular axonal guidance genes. He also proposes that the evolutionary events responsible for the development of vocal learning may be a general mechanism for the development of other complex behavioral traits.
声乐学习起源的肌动模型 - Erich Jarvis P2
本视频由科普中国和生物医学大讲堂出品
Erich Jarvis (Duke/HHMI) Part 2: Motor theory of vocal learning origin
In Part 1, Jarvis explains that vocal learning is the ability to hear a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (parrots, hummingbirds and songbirds) are capable of vocal learning. Jarvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and parrots each have pathways in specific areas of the brain that are not found in non-vocal learning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal learning monkeys.
In Part 2, Jarvis proposes a mechanism by which vocal learning may have evolved. He suggests that the brain areas that control vocal learning are the result of a duplication of a pre-existing neural circuit that controls motor movement. A similar duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In Jarvis' third talk, he demonstrates that the brain pathways necessary for vocal learning are associated with the expression of particular axonal guidance genes. He also proposes that the evolutionary events responsible for the development of vocal learning may be a general mechanism for the development of other complex behavioral traits.
声乐学习与特定的轴突导向基因的表达有关 - Erich Jarvis P3
本视频由科普中国和生物医学大讲堂出品
Erich Jarvis (Duke/HHMI) Part 3: Genes specialized in vocal learning circuits
In Part 1, Jarvis explains that vocal learning is the ability to hear a sound and repeat it. Only 5 groups of mammals (including humans) and 3 groups of birds (parrots, hummingbirds and songbirds) are capable of vocal learning. Jarvis and his lab members imaged changes in gene expression in bird's brains after singing. They found that hummingbirds, songbirds and parrots each have pathways in specific areas of the brain that are not found in non-vocal learning birds. Interestingly, analogous networks exist in the human brain but not in non-vocal learning monkeys.
In Part 2, Jarvis proposes a mechanism by which vocal learning may have evolved. He suggests that the brain areas that control vocal learning are the result of a duplication of a pre-existing neural circuit that controls motor movement. A similar duplication event may have occurred during the evolution of humans with the result that both humans and Snowball, a cockatoo, can sing and dance to a beat!
In Jarvis' third talk, he demonstrates that the brain pathways necessary for vocal learning are associated with the expression of particular axonal guidance genes. He also proposes that the evolutionary events responsible for the development of vocal learning may be a general mechanism for the development of other complex behavioral traits.
线虫的化学趋向性介绍
趋化性是细胞或生物响应化学刺激的运动过程。自然界中，趋化性对于生物感应并靠近食物源和远离可能有毒害的刺激非常重要。趋化性在细胞水平也同样重要。比 如趋化性对于受精前精细胞朝卵细胞的游动必不可少。在实验室里经常用线虫做趋化性实验，我们知道线虫天生会朝土壤的食物源运动但是远离避开毒素如重金属， 低pH物质和去垢剂。
本短片演示了如何操作趋化性实验。包括准备趋化板和线虫，操作测验和分析数据。然后，我们讨论了如何在线虫中应用趋化性作为工具来研 究学习和记忆，嗅觉适应和类似阿尔茨海默氏病的神经性疾病。线虫的趋化性实验对于研究许多生物进程的细胞和遗传机制有着无限的价值。它能帮助我们更好地了 解人类生物学，发育生物学和疾病。
Tagrisso的伴随诊断 - 陈巍学基因(31)
欢迎来到【陈巍学基因】。我们这个节目，主要是介绍基因组学，和临床分子诊断的最新技术进展。
今天，会和大家谈一谈阿斯利康在开发Tagrisso这个新药过程中对4种伴随诊断方法的研究结果。
Tagrisso是阿斯利康公司开发的一个针对EGFR基因有耐药突变的晚期非小细胞肺癌者的药物，是酪氨酸激酶抑制剂类的靶向抗癌药物。
Tagrisso可以选择性地抑制突变型的EGFR，对发生耐药的肿瘤有强抑制作用；而对野生型的EGFR的抑制作用较弱，即对身体正常表皮细胞的生长抑制作用较弱。
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