「物理」《自然》（20200430出版）一周论文导读( 三 ) |美好，一直在身边|日本|冲电气工业|

Action of a minimal contractile bactericidal nanomachine
最小收缩杀菌纳米机器的作用
▲ 作者：Peng Ge, Dean Scholl, Nikolai S. Prokhorov, Z. Hong Zhou, etc.
▲ 链接：https://www.nature.com/articles/s41586-020-2186-z
▲ 摘要
R型细菌素是最小可收缩的纳米机器，有望成为精确的抗生素。作者报告了完整的R2 绿脓杆菌素的收缩前和收缩后状态的原子模型，每个包含10个基因产物的11个独特原子模型的384个亚基。
这些结构的比较表明，绿脓杆菌素收缩期间会发生一系列事件：尾纤维触发基板三丛的横向分离；然后引发一系列事件导致鞘收缩；这种收缩将化学能转化为机械力，推动铁头管穿过细菌细胞表面，杀死细菌。
▲ Abstract
R-type bacteriocins are minimal contractile nanomachines that hold promise as precision antibiotics. Here we report the atomic model of the complete R2 pyocin in its pre-contraction and post-contraction states, each containing 384 subunits of 11 unique atomic models of 10 gene products. Comparison of these structures suggests the following sequence of events during pyocin contraction: tail fibres trigger lateral dissociation of baseplate triplexes; the dissociation then initiates a cascade of events leading to sheath contraction; and this contraction converts chemical energy into mechanical force to drive the iron-tipped tube across the bacterial cell surface, killing the bacterium.
教育Education
Measuring and forecasting progress towards the education-related SDG targets
衡量和预测教育相关的可持续发展目标的进展
▲ 作者：Joseph Friedman, Hunter York, Nicholas Graetz, Lauren Woyczynski, Joanna Whisnant, Simon I. Hay, Emmanuela Gakidou, etc.
▲ 链接：https://www.nature.com/articles/s41586-020-2198-8
▲ 摘要
教育是幸福的一个关键方面，是发展的一个关键指标。可持续发展目标（SDGs）优先考虑教育方面的进展，并将新的重点放在不平等问题上。
作者对一些国家的教育年限分布进行了建模，并使用该模型探索自1970年以来的教育不平等，并预测实现与教育相关的2030年可持续发展目标的进展。
作者分析表明，尽管世界在很大程度上有望在2030年前实现基本普及的初等教育，但中等和高等教育的完成率仍面临巨大挑战。
从全球看，到2018年，上学方面的性别差距已接近消除，但在撒哈拉以南非洲、北非和中东的部分地区，性别差异依然严重。据预测，到2030年， 18个国家的女性受教育程度将显著高于男性。全球范围内的教育不平等在2017年达到顶峰，预计到2030年将稳步下降。
▲ Abstract
【「物理」《自然》（20200430出版）一周论文导读】Education is a key dimension of well-being and a crucial indicator of development. The Sustainable Development Goals (SDGs) prioritize progress in education, with a new focus on inequality. Here we model the within-country distribution of years of schooling, and use this model to explore educational inequality since 1970 and to forecast progress towards the education-related 2030 SDG targets. We show that although the world is largely on track to achieve near-universal primary education by 2030, substantial challenges remain in the completion rates for secondary and tertiary education. Globally, the gender gap in schooling had nearly closed by 2018 but gender disparities remained acute in parts of sub-Saharan Africa, and North Africa and the Middle East. It is predicted that, by 2030, females will have achieved significantly higher educational attainment than males in 18 countries. Inequality in education reached a peak globally in 2017 and is projected to decrease steadily up to 2030.