《Nature》目录要览：2009-11-26出版
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《Nature》目录要览：2009-11-26出版
封面故事：一股有助于使AMOC保持温度的洋流
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies
“大西洋经向翻转环流” (AMOC)今后减弱的可能性在关于气候变化的讨论中居中心地位。人们的关注点集中在亚北极北大西洋海水淡化所产生的效应上，比如说通过高纬度降水的增加及冰的融化所造成的海水淡化。一项新的高分辨率海洋模型研究表明，北大西洋已经在经受来自南方的相反效应。作为对“西风南偏”现象(很可能是人类活动造成的影响)的响应，水温较高、咸度较大的印度洋海水绕非洲之角的输送正在增强。这股被称为Agulhas Leakage的洋流会抵消掉北大西洋中淡水输入造成的大西洋深水环流的可能减少，从而有可能对AMOC系统、包括“墨西哥湾流”的稳定性做出贡献。本期封面图片所示为一个高分辨率模型中400米深处的温度和水流，该模型嵌入在一个全球海洋/海冰模型中。（Letter p. 495）封面图片：Toni Schröder/ IFM-GEOMAR
处在原始环境中的膜蛋白（Membrane proteins in situ）
Structure and hydration of membranes embedded with voltage-sensing domains
很多膜蛋白的X-射线晶体结构已被确定，但关于处在它们原始膜环境中的蛋白的直接结构信息却很少。现在，一项将中子衍射、固体NMR光谱和分子动态模拟结合起来的研究，为包含S1-S4电压感应域（它们被膜蛋白用来感应膜电压变化并对其做出反应）的类脂双层膜的结构和水合提供了一幅详细的画面。可以看到，这些电压传感器采用跨膜取向，使周围的类脂双层发生小幅度变形，但变形幅度之大足以让水分子能够与膜发生相互作用，从而使带电残体发生水合，使跨膜电场成形，同时将能量和结构扰动保持到最小程度。（Article p. 473; News & Views）
多个含有不同星群的球状星团（Globular clusters a mixed bag）
Enrichment by supernovae in globular clusters with multiple populations / The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
绕银河系运转的球状星团，被认为是我们所掌握的最接近于具有统一年龄和相同组成、记录了自我们银河系诞生以来恒星演化历史的星群。不过，这些星团中最亮的一个“ω Centaruri”长期以来被认为是这一趋势的一个例外，它包含多个星群，这些星群在铁含量及年龄上相差很大。两个小组在本期Nature上报告，他们发现了更多含有不同星群的球状星团。Lee等人证实了这样一个怀疑：巨型球状星团M22包含多个具有不同钙含量的各自截然不同的星群。同类星团中几个其他星团也是如此。Ferraro等人报告，Terzan 5（“银河系核球”中一个与球状星团相似的体系）包含两个具有不同铁含量和年龄的星群。这些发现表明，ω Cen、M22、Terzan 5和其他相似星团是合并之后最终形成银河系的矮星系和其他原始天体的遗迹。（Letters pp. 480, 483; News & Views）
室温下的硅自旋电子器件（Silicon-based spintronics）
Electrical creation of spin polarization in silicon at room temperature
在自旋电子体系中，电子自旋的自由度代替电荷（传统电子体系的基本单位）作为未来基于自旋的电子技术、数据存储技术和计算技术的信息载体。受硅在当今电子领域中普遍应用的影响，人们曾努力去实现基于硅的自旋电子器件，但迄今为止，对这种器件中载荷子的成功控制仅限于低温下和一种类型的载荷子（电子），因而限制了它们的技术潜力。现在，屯特大学的一个小组研制出一种基于硅的“三端子”器件，在该器件中，他们演示了在室温下对两个电子和它们带正电的对应体（即“空穴”）的自旋极化的成功注入、操纵和检测。（Letter p. 491; News & Views）
触觉对听力影响的实验研究（Feel the noise）
Aero-tactile integration in speech perception
当我们听人讲话时，我们综合使用了不同感官：耳朵是显然的；还有眼睛，用来看讲话者的脸部怎样改变我们所听到的辅音。此前，寻求将触觉也添加到其中的实验一直无法得出结论来。很多语言通过气流的用力排出（即送气音）来改变元音或辅音（比如说，在英语中来区分“da”和“pa”的发音——后者就是送气音）。Bryan Gick和 Donald Derrick将送气音作为起点，来研究触觉是否会有助于我们来“听”声音。他们向志愿者皮肤上喷出很小的、听不到的气流，与此同时志愿者又在听一系列辅音。以手部或脖子为目标喷出的气流使得“送气音”更有可能被听见。所以，在喷出一股气流之后，“b”被误听为“p”。这项工作在今后为听觉受损者研制助听器和辅助通信设备中可能会被证明是有用的。（Letter p. 502）
RANKL/RANK在雌性体温控制中的作用（Bone protein link to fever）
Central control of fever and female body temperature by RANKL/RANK
蛋白RANK (receptor activator of nuclear factor κB)及其配体RANKL是必要的骨髓调控因子，针对RANKL的抗体作为骨质疏松症的治疗药物正在开发当中。RANKL 和 RANK也在中枢神经系统中表达，尽管其功能一直不清楚。现在，用大鼠和小鼠所做研究表明，RANKL/RANK在大脑的星细胞中表达，而且令人吃惊的是，注射了RANKL的动物会严重发烧，而通过基因工程方法使星细胞不含RANK的小鼠则不会发烧。其他数据也表明，RANKL/RANK在炎症的中枢发烧反应和在雌性的体温控制中都扮演一个角色。有趣的是，对患有与RANK突变相关的骨质疏松症的两名儿童所做临川观察显示，在肺炎发病期间没有发烧。RANKL/RANK有可能是女性绝经期有时会出现的潮热或潮红中的相关因素。（Letter p. 505）
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere westerlies
“大西洋经向翻转环流” (AMOC)今后减弱的可能性在关于气候变化的讨论中居中心地位。人们的关注点集中在亚北极北大西洋海水淡化所产生的效应上，比如说通过高纬度降水的增加及冰的融化所造成的海水淡化。一项新的高分辨率海洋模型研究表明，北大西洋已经在经受来自南方的相反效应。作为对“西风南偏”现象(很可能是人类活动造成的影响)的响应，水温较高、咸度较大的印度洋海水绕非洲之角的输送正在增强。这股被称为Agulhas Leakage的洋流会抵消掉北大西洋中淡水输入造成的大西洋深水环流的可能减少，从而有可能对AMOC系统、包括“墨西哥湾流”的稳定性做出贡献。本期封面图片所示为一个高分辨率模型中400米深处的温度和水流，该模型嵌入在一个全球海洋/海冰模型中。（Letter p. 495）封面图片：Toni Schröder/ IFM-GEOMAR
处在原始环境中的膜蛋白（Membrane proteins in situ）
Structure and hydration of membranes embedded with voltage-sensing domains
很多膜蛋白的X-射线晶体结构已被确定，但关于处在它们原始膜环境中的蛋白的直接结构信息却很少。现在，一项将中子衍射、固体NMR光谱和分子动态模拟结合起来的研究，为包含S1-S4电压感应域（它们被膜蛋白用来感应膜电压变化并对其做出反应）的类脂双层膜的结构和水合提供了一幅详细的画面。可以看到，这些电压传感器采用跨膜取向，使周围的类脂双层发生小幅度变形，但变形幅度之大足以让水分子能够与膜发生相互作用，从而使带电残体发生水合，使跨膜电场成形，同时将能量和结构扰动保持到最小程度。（Article p. 473; News & Views）
多个含有不同星群的球状星团（Globular clusters a mixed bag）
Enrichment by supernovae in globular clusters with multiple populations / The cluster Terzan 5 as a remnant of a primordial building block of the Galactic bulge
绕银河系运转的球状星团，被认为是我们所掌握的最接近于具有统一年龄和相同组成、记录了自我们银河系诞生以来恒星演化历史的星群。不过，这些星团中最亮的一个“ω Centaruri”长期以来被认为是这一趋势的一个例外，它包含多个星群，这些星群在铁含量及年龄上相差很大。两个小组在本期Nature上报告，他们发现了更多含有不同星群的球状星团。Lee等人证实了这样一个怀疑：巨型球状星团M22包含多个具有不同钙含量的各自截然不同的星群。同类星团中几个其他星团也是如此。Ferraro等人报告，Terzan 5（“银河系核球”中一个与球状星团相似的体系）包含两个具有不同铁含量和年龄的星群。这些发现表明，ω Cen、M22、Terzan 5和其他相似星团是合并之后最终形成银河系的矮星系和其他原始天体的遗迹。（Letters pp. 480, 483; News & Views）
室温下的硅自旋电子器件（Silicon-based spintronics）
Electrical creation of spin polarization in silicon at room temperature
在自旋电子体系中，电子自旋的自由度代替电荷（传统电子体系的基本单位）作为未来基于自旋的电子技术、数据存储技术和计算技术的信息载体。受硅在当今电子领域中普遍应用的影响，人们曾努力去实现基于硅的自旋电子器件，但迄今为止，对这种器件中载荷子的成功控制仅限于低温下和一种类型的载荷子（电子），因而限制了它们的技术潜力。现在，屯特大学的一个小组研制出一种基于硅的“三端子”器件，在该器件中，他们演示了在室温下对两个电子和它们带正电的对应体（即“空穴”）的自旋极化的成功注入、操纵和检测。（Letter p. 491; News & Views）
触觉对听力影响的实验研究（Feel the noise）
Aero-tactile integration in speech perception
当我们听人讲话时，我们综合使用了不同感官：耳朵是显然的；还有眼睛，用来看讲话者的脸部怎样改变我们所听到的辅音。此前，寻求将触觉也添加到其中的实验一直无法得出结论来。很多语言通过气流的用力排出（即送气音）来改变元音或辅音（比如说，在英语中来区分“da”和“pa”的发音——后者就是送气音）。Bryan Gick和 Donald Derrick将送气音作为起点，来研究触觉是否会有助于我们来“听”声音。他们向志愿者皮肤上喷出很小的、听不到的气流，与此同时志愿者又在听一系列辅音。以手部或脖子为目标喷出的气流使得“送气音”更有可能被听见。所以，在喷出一股气流之后，“b”被误听为“p”。这项工作在今后为听觉受损者研制助听器和辅助通信设备中可能会被证明是有用的。（Letter p. 502）
RANKL/RANK在雌性体温控制中的作用（Bone protein link to fever）
Central control of fever and female body temperature by RANKL/RANK
蛋白RANK (receptor activator of nuclear factor κB)及其配体RANKL是必要的骨髓调控因子，针对RANKL的抗体作为骨质疏松症的治疗药物正在开发当中。RANKL 和 RANK也在中枢神经系统中表达，尽管其功能一直不清楚。现在，用大鼠和小鼠所做研究表明，RANKL/RANK在大脑的星细胞中表达，而且令人吃惊的是，注射了RANKL的动物会严重发烧，而通过基因工程方法使星细胞不含RANK的小鼠则不会发烧。其他数据也表明，RANKL/RANK在炎症的中枢发烧反应和在雌性的体温控制中都扮演一个角色。有趣的是，对患有与RANK突变相关的骨质疏松症的两名儿童所做临川观察显示，在肺炎发病期间没有发烧。RANKL/RANK有可能是女性绝经期有时会出现的潮热或潮红中的相关因素。（Letter p. 505）
CD4+ T细胞帮助的前提（A new way to help）
CD8+ T lymphocyte mobilization to virus-infected tissue requires CD4+ T-cell help
对细胞内病原体的成功防卫需要中和抗体及细胞毒性CD8+T淋巴细胞（CTL）的反应，二者都在很大程度上依赖于CD4+ T帮助细胞的活性。Nakanishi等人报告了CD4帮助在CTL反应中一个以前没有被发现的方面：CD4+ T细胞是将CD8+ T细胞吸引到病毒感染的粘膜点所需要的。CD4+ T细胞的帮助需要干扰素-γ的分泌和局部趋化因子分泌的诱导。（Letter p. 510; New & Views）
为高柠檬酸盐合成酶编码的另一个基因（In it together）
Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen fixation
豆类植物与可将大气中的氮还原成氨的根瘤菌科的固氮菌形成一种共生关系。高柠檬酸盐是固氮酶（这种酶是固氮所必需的）的一个必要部分，但为高柠檬酸盐合成酶编码的NifV基因并不存在于大多数根瘤菌中。现在，Hakoyama等人识别出一个被称为FEN1的基因，它在模型豆类植物“百脉根”的根瘤中表达，为高柠檬酸盐合成酶编码。所以，来自宿主植物的高柠檬酸盐是根瘤菌固氮所必需的，该发现凸显了共同演化的共生关系的相互依赖性。（Letter p. 514）
植物和藻类用不同蛋白保护光合作用器官（The bright lights）
An ancient light-harvesting protein is critical for the regulation of algal photosynthesis
虽然藻类和植物需要大量光进行光合作用，但光照太多也会是有害的，造成严重氧化损伤、甚至细胞死亡。光合作用中光摄取的快速调控，通过“光合系统-II”中叶绿素分子由反馈调控的去激发为光合作用提供了一个安全阀。但是，人们对真核藻类中的这一防卫体系的机制却知之甚少。现在，用缺少为LHCSR编码的三个基因中之两个的单细胞藻类“莱茵衣藻”的突变体所做的一项研究表明，这种蛋白（光摄取复合物超级家族中一个古老成员，在维管植物中没有）是在一个光照条件存在波动的环境中生存所必需的。这意味着，植物和藻类利用不同蛋白来保护光合作用器官不受损伤。（Letter p. 518）
蛋氨酸误氨酰化及其作用（Mutation by stealth）
Innate immune and chemically triggered oxidative stress modifies translational fidelity
要使细胞正常发挥功能，将RNA信使翻译成蛋白的过程从整体上来说需要是准确的。然而现在，用HeLa细胞所做研究表明，蛋白合成中所用蛋氨酸残迹的约1%被氨酰化成了在教科书上被认为不正确的tRNA。令人吃惊的是，当细胞通过病毒感染或用病毒或细菌类Toll-样受体配体处理而处于压力之下时，由蛋氨酸被错误氨酰化而生成的tRNA比例显著增加。用其他氨基酸所做试验表明，该现象仅限于蛋氨酸，而且因为蛋氨酸残迹已知保护蛋白不受活性氧分子所造成损伤的影响，所以一种可能性是，蛋氨酸误氨酰化是对细胞压力的一种自然的保护性反应。（Letter p. 522）
CD8+ T lymphocyte mobilization to virus-infected tissue requires CD4+ T-cell help
对细胞内病原体的成功防卫需要中和抗体及细胞毒性CD8+T淋巴细胞（CTL）的反应，二者都在很大程度上依赖于CD4+ T帮助细胞的活性。Nakanishi等人报告了CD4帮助在CTL反应中一个以前没有被发现的方面：CD4+ T细胞是将CD8+ T细胞吸引到病毒感染的粘膜点所需要的。CD4+ T细胞的帮助需要干扰素-γ的分泌和局部趋化因子分泌的诱导。（Letter p. 510; New & Views）
为高柠檬酸盐合成酶编码的另一个基因（In it together）
Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen fixation
豆类植物与可将大气中的氮还原成氨的根瘤菌科的固氮菌形成一种共生关系。高柠檬酸盐是固氮酶（这种酶是固氮所必需的）的一个必要部分，但为高柠檬酸盐合成酶编码的NifV基因并不存在于大多数根瘤菌中。现在，Hakoyama等人识别出一个被称为FEN1的基因，它在模型豆类植物“百脉根”的根瘤中表达，为高柠檬酸盐合成酶编码。所以，来自宿主植物的高柠檬酸盐是根瘤菌固氮所必需的，该发现凸显了共同演化的共生关系的相互依赖性。（Letter p. 514）
植物和藻类用不同蛋白保护光合作用器官（The bright lights）
An ancient light-harvesting protein is critical for the regulation of algal photosynthesis
虽然藻类和植物需要大量光进行光合作用，但光照太多也会是有害的，造成严重氧化损伤、甚至细胞死亡。光合作用中光摄取的快速调控，通过“光合系统-II”中叶绿素分子由反馈调控的去激发为光合作用提供了一个安全阀。但是，人们对真核藻类中的这一防卫体系的机制却知之甚少。现在，用缺少为LHCSR编码的三个基因中之两个的单细胞藻类“莱茵衣藻”的突变体所做的一项研究表明，这种蛋白（光摄取复合物超级家族中一个古老成员，在维管植物中没有）是在一个光照条件存在波动的环境中生存所必需的。这意味着，植物和藻类利用不同蛋白来保护光合作用器官不受损伤。（Letter p. 518）
蛋氨酸误氨酰化及其作用（Mutation by stealth）
Innate immune and chemically triggered oxidative stress modifies translational fidelity
要使细胞正常发挥功能，将RNA信使翻译成蛋白的过程从整体上来说需要是准确的。然而现在，用HeLa细胞所做研究表明，蛋白合成中所用蛋氨酸残迹的约1%被氨酰化成了在教科书上被认为不正确的tRNA。令人吃惊的是，当细胞通过病毒感染或用病毒或细菌类Toll-样受体配体处理而处于压力之下时，由蛋氨酸被错误氨酰化而生成的tRNA比例显著增加。用其他氨基酸所做试验表明，该现象仅限于蛋氨酸，而且因为蛋氨酸残迹已知保护蛋白不受活性氧分子所造成损伤的影响，所以一种可能性是，蛋氨酸误氨酰化是对细胞压力的一种自然的保护性反应。（Letter p. 522）
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NEWS AND VIEWS
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Biodiversity: Skates on thin ice p417
The common skate is not at all common: this large marine fish has 'critically
endangered' status. That it turns out to be not one species, but two, is a
sharp reminder that good taxonomy must underpin conservation.
Nicholas K. Dulvy and John D. Reynolds
doi:10.1038/462417a
http://www.nature.com/nature/journal/v462/n7272/full/462417a.html
Immunology: A helpers' guide to infection pp418-419
Killer T cells were thought to patrol the body unhindered, freely gaining
access to sites of infection. But it seems that, at least in some body
tissues, helper T cells must pave the way for killer T-cell entry.
Thomas Gebhardt and Francis R. Carbone
doi:10.1038/462418a
http://www.nature.com/nature/journal/v462/n7272/full/462418a.html
Solid-state physics: Silicon spintronics warms up pp419-420
Electrical injection and detection of spin-polarized electrons in a silicon
chip have now been demonstrated at room temperature, paving the way to the
development of low-power semiconductor spintronics circuitry.
Michael E. Flatte
doi:10.1038/462419a
http://www.nature.com/nature/journal/v462/n7272/full/462419a.html
Structural biology: Highly charged meetings pp420-421
When it comes to proteins and their environments, opposites repel. So how
is the highly charged, polar helix of a transmembrane ion channel
accommodated by a non-polar membrane? Easily, if the charges are buried.
Anthony G. Lee
doi:10.1038/462420a
http://www.nature.com/nature/journal/v462/n7272/full/462420a.html
Astrophysics: Assortment in the Galaxy pp421-422
Observations of star clusters in the Milky Way defy the view that the
constituents of these systems are almost invariably chemically alike.
The outlying clusters could be the tattered relics of once larger systems.
Judith G. Cohen
doi:10.1038/462421a
http://www.nature.com/nature/journal/v462/n7272/full/462421a.html
50 & 100 years ago p422
doi:10.1038/462422a
http://www.nature.com/nature/journal/v462/n7272/full/462422a.html
Obituary: Paul C. Zamecnik (1912-2009) p423
Trailblazer in the study of protein synthesis.
Thoru Pederson
doi:10.1038/462423a
http://www.nature.com/nature/journal/v462/n7272/full/462423a.html
----------------------
INSIGHT
----------------------
EDITORIAL
Biomaterials p425
Rosamund Daw and Stefano Tonzani
doi:10.1038/462425a
http://www.nature.com/nature/journal/v462/n7272/full/462425a.html
REVIEW ARTICLE
Inspiration and application in the evolution of biomaterials pp426-432
Nathaniel Huebsch and David J. Mooney
doi:10.1038/nature08601
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08601.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08601.html
Designing materials to direct stem-cell fate pp433-441
Matthias P. Lutolf, Penney M. Gilbert and Helen M. Blau
doi:10.1038/nature08602
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08602.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08602.html
Biomaterial systems for mechanosensing and actuation pp442-448
Peter Fratzl and Friedrich G. Barth
doi:10.1038/nature08603
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08603.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08603.html
Materials engineering for immunomodulation pp449-460
Jeffrey A. Hubbell, Susan N. Thomas and Melody A. Swartz
doi:10.1038/nature08604
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08604.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08604.html
Drivers of biodiagnostic development pp461-464
David A. Giljohann and Chad A. Mirkin
doi:10.1038/nature08605
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08605.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08605.html
----------------------
ARTICLES
----------------------
Structure of the formate transporter FocA reveals a pentameric aquaporin-like
channel pp467-472
The formate-nitrite transporter family, of which FocA is a representative
member, is known to transport short-chain acids in bacteria, archaea, fungi,
algae and parasites; however, the structure and transport mechanism of these
transporters remain unknown. Here, study of the crystal structure of Escherichia
coli FocA reveals that the overall structure of FocA closely resembles that of
aquaporin, suggesting that it is in fact a channel, rather than a transporter.
Yi Wang et al.
doi:10.1038/nature08610
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08610.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08610.html
Structure and hydration of membranes embedded with voltage-sensing domains
pp473-479
Despite the growing number of X-ray crystal structures of membrane proteins,
direct structural information about proteins in their native membrane environment
remains scarce. Neutron diffraction, solid-state nuclear magnetic resonance
spectroscopy and molecular dynamics simulations are now used to investigate the
structure and hydration of bilayer membranes containing S1-S4 voltage-sensing domains.
Dmitriy Krepkiy et al.
doi:10.1038/nature08542
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08542.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08542.html
----------------------
LETTERS
----------------------
Enrichment by supernovae in globular clusters with multiple populations
pp480-482
The globular star clusters ω Centauri and M 22 are thought to be the
remaining cores of disrupted dwarf galaxies, but they are viewed as exceptional.
Here, calcium abundances for seven globular clusters are reported and compared
to ω Centauri. The results lead the authors to conclude that these
globular clusters are also probably the relics of more massive primeval dwarf
galaxies that merged and disrupted to form the proto-Galaxy.
Jae-Woo Lee, Young-Woon Kang, Jina Lee and Young-Wook Lee
doi:10.1038/nature08565
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08565.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08565.html
The cluster Terzan 5 as a remnant of a primordial building block of the Galactic
bulge pp483-486
ω Centauri is the only globular star cluster in the Galactic halo known to
have multiple stellar populations with a significant spread in iron abundance
and age. But now Terzan 5, a globular-cluster-like system in the Galactic bulge,
is reported to have two stellar populations with different iron contents and
ages. So Terzan 5 could be the surviving remnant of one of the primordial
building blocks which are thought to merge and form galaxy bulges.
F. R. Ferraro et al.
doi:10.1038/nature08581
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08581.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08581.html
Two-dimensional normal-state quantum oscillations in a superconducting
heterostructure pp487-490
Heavily doped semiconductors, which can exhibit superconductivity, and
low-dimensional superconducting thin films are currently limited by interface
scattering, electronic or atomic-scale disorder. Here, the fabrication of a
high-quality superconducting layer within a thin-film heterostructure based on
SrTiO3 is reported. By selectively doping a narrow region of SrTiO3 a
two-dimensional superconductor is formed that should provide a model system
in which to explore the quantum transport and interplay of both
superconducting and normal electrons.
Y. Kozuka et al.
doi:10.1038/nature08566
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08566.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08566.html
Electrical creation of spin polarization in silicon at room temperature pp491-494
Spintronics aims to represent digital information using spin orientation
rather than electron charge, ideally at room temperature and in silicon, which
is already ubiquitous in present-day technologies. But so far successful control
of spin has only been achieved for electrons and at low temperatures. Now
room-temperature injection, manipulation and detection of spin polarization of
both electrons and their positively charged counterparts (holes) brings the
realization of silicon spintronic devices closer.
Saroj P. Dash et al.
doi:10.1038/nature08570
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08570.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08570.html
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere
westerlies pp495-498
The Agulhas leakage allows the transport of warm and salty Indian Ocean waters
into the Atlantic Ocean and provides the main source of heat and salt for the
surface branch of the Atlantic meridional overturning circulation. The results
of a high-resolution ocean general circulation model now show that the transport
of Indian Ocean waters into the South Atlantic via the Agulhas leakage has
increased during the past decades in response to a change in wind forcing.
A. Biastoch, C. W. Boning, F. U. Schwarzkopf and J. R. E. Lutjeharms
doi:10.1038/nature08519
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08519.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08519.html
Convective upwelling in the mantle beneath the Gulf of California pp499-501
The Gulf of California is a part of the world's seafloor-spreading system
surrounded by enough seismometers to provide sufficiently high horizontal
resolution to address the long-standing debate about the relative importance
of dynamic and passive upwelling in the shallow mantle beneath spreading centres.
Here, Rayleigh-wave tomography is used to image the shear velocity in the upper
200 kilometres or so of the mantle; the results suggest areas of dynamic upwelling.
Yun Wang, Donald W. Forsyth and Brian Savage
doi:10.1038/nature08552
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08552.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08552.html
Aero-tactile integration in speech perception pp502-504
Auditory perception can be enhanced or interfered with by visual information
from a speaker's face, but previous studies looking at whether tactile
information influences speech perception have been limited. Here, by applying
inaudible air puffs on participants' skin and thereby mimicking the tiny bursts
of aspiration produced by certain speech sounds, it is found that syllables are
more likely to be heard as aspirated, demonstrating that tactile information is
also integrated in auditory perception.
Bryan Gick and Donald Derrick
doi:10.1038/nature08572
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08572.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08572.html
Central control of fever and female body temperature by RANKL/RANK pp505-509
Receptor-activator of NF-[kappa]B ligand (RANKL) and its receptor RANK are
known to be essential regulators of bone remodelling, lymph node organogenesis
and formation of a lactating mammary gland, but the functional relevance of
their expression in the brain has been unclear. RANKL and RANK are now reported
to have an essential role in the brain, with the central injection of RANKL into
mice and rats triggering severe fever, and a further potential role in the
control of thermoregulation in females.
Reiko Hanada et al.
doi:10.1038/nature08596
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08596.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08596.html
CD8+ T lymphocyte mobilization to virus-infected tissue requires CD4+ T-cell
help pp510-513
CD4+ T helper cells provide critical signals for the generation of cytotoxic
CD8+ T lymphocyte (CTL) responses in vivo as well as promoting protective CD8+
memory T-cell development. However, the role of CD4 help in the control of CTL
responses at the effector stage is unknown. Here, fully helped effector CTLs
are shown to rely on CD4+ T cells to provide the necessary cue for entry into
infected tissue.
Yusuke Nakanishi, Bao Lu, Craig Gerard and Akiko Iwasaki
doi:10.1038/nature08511
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08511.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08511.html
Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen
fixation pp514-517
Homocitrate is an essential component of the enzyme nitrogenase, which is
required for nitrogen fixation. However, the NifV gene, which encodes homocitrate
synthase, is not present in most rhizobial species that require symbiotic
association with legumes to perform efficient nitrogen fixation. The FEN1 gene
of a model legume, Lotus japonicus, is now shown to overcome the lack of NifV
in rhizobia for symbiotic nitrogen fixation.
Tsuneo Hakoyama et al.
doi:10.1038/nature08594
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08594.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08594.html
An ancient light-harvesting protein is critical for the regulation of algal
photosynthesis pp518-521
Although light is needed for photosynthesis, it can also cause severe oxidative
damage. For this reason, protective mechanisms involving feedback-regulated
de-excitation of chlorophyll molecules in photosystem II (qE) have evolved. In
contrast to flowering plants, little is known about the qE mechanism of
eukaryotic algae. Here, a qE-deficient mutant green alga is shown to lack two
of the three genes encoding LHCSR, an ancient member of the light-harvesting
complex superfamily.
Graham Peers et al.
doi:10.1038/nature08587
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08587.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08587.html
Innate immune and chemically triggered oxidative stress modifies translational
fidelity pp522-526
Accurate transfer RNA (tRNA) aminoacylation is necessary for translational
fidelity; however, the accuracy of tRNA aminoacylation in vivo is uncertain.
In mammalian cells, approximately 1% of methionine residues used in protein
synthesis are now shown to be aminoacylated to non-methionyl-tRNAs. Furthermore,
misacylation of methionine increases up to tenfold upon exposing cells to
viruses, toll-like receptor li
NEWS AND VIEWS
----------------------
Biodiversity: Skates on thin ice p417
The common skate is not at all common: this large marine fish has 'critically
endangered' status. That it turns out to be not one species, but two, is a
sharp reminder that good taxonomy must underpin conservation.
Nicholas K. Dulvy and John D. Reynolds
doi:10.1038/462417a
http://www.nature.com/nature/journal/v462/n7272/full/462417a.html
Immunology: A helpers' guide to infection pp418-419
Killer T cells were thought to patrol the body unhindered, freely gaining
access to sites of infection. But it seems that, at least in some body
tissues, helper T cells must pave the way for killer T-cell entry.
Thomas Gebhardt and Francis R. Carbone
doi:10.1038/462418a
http://www.nature.com/nature/journal/v462/n7272/full/462418a.html
Solid-state physics: Silicon spintronics warms up pp419-420
Electrical injection and detection of spin-polarized electrons in a silicon
chip have now been demonstrated at room temperature, paving the way to the
development of low-power semiconductor spintronics circuitry.
Michael E. Flatte
doi:10.1038/462419a
http://www.nature.com/nature/journal/v462/n7272/full/462419a.html
Structural biology: Highly charged meetings pp420-421
When it comes to proteins and their environments, opposites repel. So how
is the highly charged, polar helix of a transmembrane ion channel
accommodated by a non-polar membrane? Easily, if the charges are buried.
Anthony G. Lee
doi:10.1038/462420a
http://www.nature.com/nature/journal/v462/n7272/full/462420a.html
Astrophysics: Assortment in the Galaxy pp421-422
Observations of star clusters in the Milky Way defy the view that the
constituents of these systems are almost invariably chemically alike.
The outlying clusters could be the tattered relics of once larger systems.
Judith G. Cohen
doi:10.1038/462421a
http://www.nature.com/nature/journal/v462/n7272/full/462421a.html
50 & 100 years ago p422
doi:10.1038/462422a
http://www.nature.com/nature/journal/v462/n7272/full/462422a.html
Obituary: Paul C. Zamecnik (1912-2009) p423
Trailblazer in the study of protein synthesis.
Thoru Pederson
doi:10.1038/462423a
http://www.nature.com/nature/journal/v462/n7272/full/462423a.html
----------------------
INSIGHT
----------------------
EDITORIAL
Biomaterials p425
Rosamund Daw and Stefano Tonzani
doi:10.1038/462425a
http://www.nature.com/nature/journal/v462/n7272/full/462425a.html
REVIEW ARTICLE
Inspiration and application in the evolution of biomaterials pp426-432
Nathaniel Huebsch and David J. Mooney
doi:10.1038/nature08601
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08601.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08601.html
Designing materials to direct stem-cell fate pp433-441
Matthias P. Lutolf, Penney M. Gilbert and Helen M. Blau
doi:10.1038/nature08602
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08602.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08602.html
Biomaterial systems for mechanosensing and actuation pp442-448
Peter Fratzl and Friedrich G. Barth
doi:10.1038/nature08603
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08603.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08603.html
Materials engineering for immunomodulation pp449-460
Jeffrey A. Hubbell, Susan N. Thomas and Melody A. Swartz
doi:10.1038/nature08604
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08604.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08604.html
Drivers of biodiagnostic development pp461-464
David A. Giljohann and Chad A. Mirkin
doi:10.1038/nature08605
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08605.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08605.html
----------------------
ARTICLES
----------------------
Structure of the formate transporter FocA reveals a pentameric aquaporin-like
channel pp467-472
The formate-nitrite transporter family, of which FocA is a representative
member, is known to transport short-chain acids in bacteria, archaea, fungi,
algae and parasites; however, the structure and transport mechanism of these
transporters remain unknown. Here, study of the crystal structure of Escherichia
coli FocA reveals that the overall structure of FocA closely resembles that of
aquaporin, suggesting that it is in fact a channel, rather than a transporter.
Yi Wang et al.
doi:10.1038/nature08610
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08610.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08610.html
Structure and hydration of membranes embedded with voltage-sensing domains
pp473-479
Despite the growing number of X-ray crystal structures of membrane proteins,
direct structural information about proteins in their native membrane environment
remains scarce. Neutron diffraction, solid-state nuclear magnetic resonance
spectroscopy and molecular dynamics simulations are now used to investigate the
structure and hydration of bilayer membranes containing S1-S4 voltage-sensing domains.
Dmitriy Krepkiy et al.
doi:10.1038/nature08542
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08542.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08542.html
----------------------
LETTERS
----------------------
Enrichment by supernovae in globular clusters with multiple populations
pp480-482
The globular star clusters ω Centauri and M 22 are thought to be the
remaining cores of disrupted dwarf galaxies, but they are viewed as exceptional.
Here, calcium abundances for seven globular clusters are reported and compared
to ω Centauri. The results lead the authors to conclude that these
globular clusters are also probably the relics of more massive primeval dwarf
galaxies that merged and disrupted to form the proto-Galaxy.
Jae-Woo Lee, Young-Woon Kang, Jina Lee and Young-Wook Lee
doi:10.1038/nature08565
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08565.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08565.html
The cluster Terzan 5 as a remnant of a primordial building block of the Galactic
bulge pp483-486
ω Centauri is the only globular star cluster in the Galactic halo known to
have multiple stellar populations with a significant spread in iron abundance
and age. But now Terzan 5, a globular-cluster-like system in the Galactic bulge,
is reported to have two stellar populations with different iron contents and
ages. So Terzan 5 could be the surviving remnant of one of the primordial
building blocks which are thought to merge and form galaxy bulges.
F. R. Ferraro et al.
doi:10.1038/nature08581
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08581.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08581.html
Two-dimensional normal-state quantum oscillations in a superconducting
heterostructure pp487-490
Heavily doped semiconductors, which can exhibit superconductivity, and
low-dimensional superconducting thin films are currently limited by interface
scattering, electronic or atomic-scale disorder. Here, the fabrication of a
high-quality superconducting layer within a thin-film heterostructure based on
SrTiO3 is reported. By selectively doping a narrow region of SrTiO3 a
two-dimensional superconductor is formed that should provide a model system
in which to explore the quantum transport and interplay of both
superconducting and normal electrons.
Y. Kozuka et al.
doi:10.1038/nature08566
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08566.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08566.html
Electrical creation of spin polarization in silicon at room temperature pp491-494
Spintronics aims to represent digital information using spin orientation
rather than electron charge, ideally at room temperature and in silicon, which
is already ubiquitous in present-day technologies. But so far successful control
of spin has only been achieved for electrons and at low temperatures. Now
room-temperature injection, manipulation and detection of spin polarization of
both electrons and their positively charged counterparts (holes) brings the
realization of silicon spintronic devices closer.
Saroj P. Dash et al.
doi:10.1038/nature08570
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08570.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08570.html
Increase in Agulhas leakage due to poleward shift of Southern Hemisphere
westerlies pp495-498
The Agulhas leakage allows the transport of warm and salty Indian Ocean waters
into the Atlantic Ocean and provides the main source of heat and salt for the
surface branch of the Atlantic meridional overturning circulation. The results
of a high-resolution ocean general circulation model now show that the transport
of Indian Ocean waters into the South Atlantic via the Agulhas leakage has
increased during the past decades in response to a change in wind forcing.
A. Biastoch, C. W. Boning, F. U. Schwarzkopf and J. R. E. Lutjeharms
doi:10.1038/nature08519
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08519.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08519.html
Convective upwelling in the mantle beneath the Gulf of California pp499-501
The Gulf of California is a part of the world's seafloor-spreading system
surrounded by enough seismometers to provide sufficiently high horizontal
resolution to address the long-standing debate about the relative importance
of dynamic and passive upwelling in the shallow mantle beneath spreading centres.
Here, Rayleigh-wave tomography is used to image the shear velocity in the upper
200 kilometres or so of the mantle; the results suggest areas of dynamic upwelling.
Yun Wang, Donald W. Forsyth and Brian Savage
doi:10.1038/nature08552
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08552.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08552.html
Aero-tactile integration in speech perception pp502-504
Auditory perception can be enhanced or interfered with by visual information
from a speaker's face, but previous studies looking at whether tactile
information influences speech perception have been limited. Here, by applying
inaudible air puffs on participants' skin and thereby mimicking the tiny bursts
of aspiration produced by certain speech sounds, it is found that syllables are
more likely to be heard as aspirated, demonstrating that tactile information is
also integrated in auditory perception.
Bryan Gick and Donald Derrick
doi:10.1038/nature08572
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08572.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08572.html
Central control of fever and female body temperature by RANKL/RANK pp505-509
Receptor-activator of NF-[kappa]B ligand (RANKL) and its receptor RANK are
known to be essential regulators of bone remodelling, lymph node organogenesis
and formation of a lactating mammary gland, but the functional relevance of
their expression in the brain has been unclear. RANKL and RANK are now reported
to have an essential role in the brain, with the central injection of RANKL into
mice and rats triggering severe fever, and a further potential role in the
control of thermoregulation in females.
Reiko Hanada et al.
doi:10.1038/nature08596
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08596.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08596.html
CD8+ T lymphocyte mobilization to virus-infected tissue requires CD4+ T-cell
help pp510-513
CD4+ T helper cells provide critical signals for the generation of cytotoxic
CD8+ T lymphocyte (CTL) responses in vivo as well as promoting protective CD8+
memory T-cell development. However, the role of CD4 help in the control of CTL
responses at the effector stage is unknown. Here, fully helped effector CTLs
are shown to rely on CD4+ T cells to provide the necessary cue for entry into
infected tissue.
Yusuke Nakanishi, Bao Lu, Craig Gerard and Akiko Iwasaki
doi:10.1038/nature08511
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08511.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08511.html
Host plant genome overcomes the lack of a bacterial gene for symbiotic nitrogen
fixation pp514-517
Homocitrate is an essential component of the enzyme nitrogenase, which is
required for nitrogen fixation. However, the NifV gene, which encodes homocitrate
synthase, is not present in most rhizobial species that require symbiotic
association with legumes to perform efficient nitrogen fixation. The FEN1 gene
of a model legume, Lotus japonicus, is now shown to overcome the lack of NifV
in rhizobia for symbiotic nitrogen fixation.
Tsuneo Hakoyama et al.
doi:10.1038/nature08594
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08594.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08594.html
An ancient light-harvesting protein is critical for the regulation of algal
photosynthesis pp518-521
Although light is needed for photosynthesis, it can also cause severe oxidative
damage. For this reason, protective mechanisms involving feedback-regulated
de-excitation of chlorophyll molecules in photosystem II (qE) have evolved. In
contrast to flowering plants, little is known about the qE mechanism of
eukaryotic algae. Here, a qE-deficient mutant green alga is shown to lack two
of the three genes encoding LHCSR, an ancient member of the light-harvesting
complex superfamily.
Graham Peers et al.
doi:10.1038/nature08587
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08587.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08587.html
Innate immune and chemically triggered oxidative stress modifies translational
fidelity pp522-526
Accurate transfer RNA (tRNA) aminoacylation is necessary for translational
fidelity; however, the accuracy of tRNA aminoacylation in vivo is uncertain.
In mammalian cells, approximately 1% of methionine residues used in protein
synthesis are now shown to be aminoacylated to non-methionyl-tRNAs. Furthermore,
misacylation of methionine increases up to tenfold upon exposing cells to
viruses, toll-like receptor li
gands or oxidative stress.
Nir Netzer et al.
doi:10.1038/nature08576
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08576.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08576.html
----------------------
FUTURES
----------------------
The imitation game p534
Being human.
Shelly Li
doi:10.1038/462534a
http://www.nature.com/nature/journal/v462/n7272/full/462534a.html
Nir Netzer et al.
doi:10.1038/nature08576
Abstract: http://www.nature.com/nature/journal/v462/n7272/abs/nature08576.html
Article: http://www.nature.com/nature/journal/v462/n7272/full/nature08576.html
----------------------
FUTURES
----------------------
The imitation game p534
Being human.
Shelly Li
doi:10.1038/462534a
http://www.nature.com/nature/journal/v462/n7272/full/462534a.html
| 《Nature》目录要览 — 2011-04-28出版 |
| 《Nature》目录要览：2011-01-20出版 |
| 《Nature》目录要览：2010-12-23出版 |
| 《Nature》目录要览：2010-12-16出版 |
| 《Nature》目录要览：2010-12-09出版 |
| 《Nature》目录要览：2010-12-02出版 |
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