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Mosquitoes transmit many diseases among humans, including malaria, dengue, West Nile fever, and Zika. To keep mosquitoes from spreading disease, we must first understand their life cycle. The life cyc...

蚊子在人类中传播许多疾病，包括疟疾、登革热、西尼罗河热和寨卡病毒。为了防止蚊子传播疾病，我们必须首先了解它们的生命周期。蚊子的生命周期（就像许多其他昆虫一样）有四个阶段：卵、幼虫、蛹和成虫。 雌性蚊子在静水体上或附近产卵。一些物种喜欢...

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There are a hundred places in New York like Gabriel's.Up front is a small bar,in back there are a few booths and a half of dozen tables,the husband is the cook,and the wife takes care of the bar.It ha...

纽约有一百个像 Gabriel's 一样的地方。前面是一个小酒吧，后面有几个卡座和六张桌子，丈夫是厨师，妻子打理酒吧。它有一个名字，这是丈夫或妻子的名字，或者他们来自的城镇——Lois、Tony's、Estelle's、Maria's、Ca...

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This is a 3D model of a DNA molecule. It is made up of two strands that form a double helix. If we unwind the helix, we can see that each strand is a chain of building blocks called nucleotides. Le...

这是 DNA 分子的 3D 模型。它由形成双螺旋的两条链组成。如果我们展开螺旋，我们可以看到每条链都是一条称为核苷酸的构建块链。 让我们拿出这五对核苷酸，仔细看看它们的部分。这些图表显示了核苷酸的化学结构。核苷酸连接在一起。它们在一条...

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Dengue virus is an RNA virus. Its outer surface is covered with envelope proteins surrounding a lipid bilayer envelope. Inside the envelope is a capsid shell that contains the virus’s RNA genome. Immu...

登革热病毒是一种 RNA 病毒。它的外表面覆盖着围绕脂质双层包膜的包膜蛋白。包膜内是一个衣壳，其中包含病毒的 RNA 基因组。免疫细胞是登革热病毒的目标。在登革热感染中，有两种细胞表面受体分子很重要。同源受体参与正常感染，而 FC 受体参与...

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Alright so now we're going to go into a little bit more detail on Dengue virus since it's once the subjects of our talk today. If you rotate it very carefully, I'm going to highlight for you the penta...

好了，现在我们将更详细地介绍登革热病毒，因为它曾经是我们今天演讲的主题。如果你非常小心地旋转它，我将为你突出显示每个顶点的五边形，所以它就在那里。如果你非常敏锐，你可以发现一个三重对称轴。这对应于每个三角形面的中心。现在，令人惊讶的是，整个...

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Like all young mammals, human infants depend on milk for nutrition. Milk is rich in lactose, a disaccharide made from two sugar molecules. Lactose cannot be directly absorbed in the small intestine. T...

像所有年轻的哺乳动物一样，人类婴儿依赖牛奶获取营养。牛奶富含乳糖，这是一种由两个糖分子组成的二糖。乳糖不能在小肠中直接吸收。为了消化乳糖，哺乳动物会产生乳糖酶。现在乳糖与乳糖酶的活性位点结合。该酶水解乳糖并产生两种单糖，葡萄糖和半乳糖。然后...

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Mutations arise at random in a population. Suppose a mutation arises that causes adults to produce lactase in a population that doesn't have any dairy cows. Adults don't drink milk, so producing the l...

突变在群体中随机出现。假设出现突变，导致成虫在没有任何奶牛的种群中产生乳糖酶。成年人不喝牛奶，因此产生乳糖酶是浪费能源。突变丢失或仍然罕见。如果同样的突变发生在人们驯化奶牛的人群中，成年人可以喝牛奶而不会生病，并从牛奶中的糖分中获得能量。他...

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Polymerase chain reaction-- or PCR-- uses repeated cycles of heating and cooling to make many copies of a specific region of DNA. First, the temperature is raised to near boiling, causing the double s...

聚合酶链反应 （PCR） 使用重复的加热和冷却循环来制作 DNA 特定区域的许多副本。首先，将温度升高到接近沸点，导致双链 DNA 分离或变性成单链。当温度降低时，短 DNA 序列（称为引物）与靶 DNA 序列上的互补匹配结合或退火。 ...