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[点击科学]2020年2月点击科学

陶 陶 编译

2020-02/总第287期

阅读数3

6473.jpg

2020-01-03

封面图展示的是一种食肉植物丝叶狸藻未发育成熟的捕食构造(宽度约为200 μm),图示说明了它的2层细胞结构。作为一种捕捉动物的机制,这种杯状的叶片已经进化了很多次。通过分析丝叶狸藻,研究人员将分子遗传学和计算机建模结合在一起,揭示出基因表达域的变化是如何解释从具有平面叶片的物种到杯状叶片的重复进化。


Immature trap of the carnivorous plant Utricularia gibba (~200 μm in width), illustrating its two-layered cellular structure. Such cup-shaped leaves have evolved multiple times as a mechanism for trapping animals. Analyzing U. gibba, researchers used a combination of molecular genetics and computer modeling to reveal how shifts in gene expression domains can account for repeated evolution of cup shapes from species with planar leaves.



6474.jpg

2020-01-10

封面图展示的是通过艺术手法表现的雷暴上空多波长辐射现象,数据来源于国际空间站大气-空间相互作用监测器。与闪电相关联的高电场(图中浅蓝色部分)引发了地球上的伽马射线闪光(洋红色)。由此产生的电磁脉冲会产生一个“elve”——也就是一个膨胀的紫外辐射环(红白相间的部分)。


An artist's impression of multiwavelength emission above a thunderstorm, based on data from the Atmosphere-Space Interactions Monitor on the International Space Station. The high electric field associated with lightning (light blue) generates a terrestrial gamma-ray flash (magenta). The resulting electromagnetic pulse causes an elve—an expanding ring of ultraviolet emission (red and white).


6475.jpg

2020-01-17

封面图展示的是一个哺乳动物小脑颗粒神经元的半透明染色细胞核。这张3D效果图展示了由电子显微镜和低温超分辨率荧光显微镜所成像的特异性异染色质亚型,由组蛋白重叠所定义。环绕细胞核的一层半透明薄壳代表核膜,而3D渲染的电子显微镜数据(图中灰色部分)薄片则穿过了细胞核。图中右下角的圆圈是线粒体的横断面。


Translucently colored nucleus of a mammalian cerebellar granule neuron. This 3D rendering illustrates the specific heterochromatin subdomain type defined by the overlap of histones imaged by electron microscopy (EM) and cryogenic super-resolution fluorescence microscopy. A thin translucent shell surrounding the nucleus represents the nuclear membrane, and a thin slab of 3D-rendered EM data (gray) slices through the nucleus. The circles at lower right are cross-sectional views of mitochondria.


6476.jpg

2020-01-24

封面图上展示的这些合成化学品是现代生活的重要组成部分,但在许多情况下,现有的全球生产、分配及废弃处置系统对环境和人类健康造成了损害。化学合成的创新、环境监测,以及暴露与风险分析方面将确保未来的化学制品降低持久性,具有更大的效力,并推动我们走向可持续的未来。


Synthetic chemicals are important components of modern life, but the current system of global production, distribution, and disposal has, in many instances, caused damage to the environment and human health. Innovations in chemical synthesis, environmental monitoring, and analysis of exposure and risk will ensure that tomorrow's chemicals are less persistent, have greater potency, and move us toward a sustainable future.

(陶 陶 编译)■


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