来源:科学网 发布时间:2019/1/9 15:10:09
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《科学》论文导读:2018年12月21日

 

 
 
植物学 Botany
 
 
 
 
A hidden cradle of plant evolution in Permian tropical lowlands
 
二叠纪赤道低地植物进化的隐藏摇篮
 
▲ 作者:Patrick Blomenkemper, Hans Kerp, Abdalla Abu Hamad, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1414
 
 
 
▲ 摘要:
 
今天的纬度方向生物多样性梯度,深深植根于整个地质时期地球生物区系的进化历史。
 
 
 
在海相环境中,低纬度地区出现的最早化石揭示了热带是很多动物群的摇篮。
 
 
 
不过,陆地化石记录,尤其是来自被认为驱动进化创新的较干旱环境的化石很稀少。
 
 
 
这里,我们展示了形形色色的植物化石集合。它们来自今天的约旦二叠纪赤道低地,蕴藏着在中生代均占据主导地位的3大种子植物谱系的早期发育记录,包括任何现存针叶树家族的最古老代表。
 
 
 
这些发现展示了在易受干扰地区通常不被观察到的现代植物群的早期进化起源。
 
 
 
▲ Abstract
 
The latitudinal biodiversity gradient today has deep roots in the evolutionary history of Earth’s biota over geologic time. In the marine realm, earliest fossil occurrences at low latitudes reveal a tropical cradle for many animal groups. However, the terrestrial fossil record—especially from drier environments that are thought to drive evolutionary innovation—is sparse. We present mixed plant-fossil assemblages from Permian equatorial lowlands in present-day Jordan that harbor precocious records of three major seed-plant lineages that all became dominant during the Mesozoic, including the oldest representative of any living conifer family. These finds offer a glimpse of the early evolutionary origins of modern plant groups in disturbance-prone tropical habitats that are usually hidden from observation.
 
 
 
Root branching toward water involves posttranslational modification of transcription factor ARF7
 
根系向水分支涉及转录因子ARF7翻译后修饰
 
▲ 作者:Beatriz Orosa-Puente, Nicola Leftley, Daniel von Wangenheim, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1407
 
 
 
▲ 摘要:
 
 
 
植物通过改变根系构型适应不同种类的土壤条件。比如,根在同水接触时通过利用水力模式响应产生分支。
 
 
 
我们报告称,水力模式依赖于生长素响应因子ARF7。该转录因子诱导其靶向基因LBD16在侧根生成细胞中的不对称表达。
 
 
 
这种有差别的表达模式受到拥有小分子泛素样修饰体(SUMO)蛋白质的ARF7翻译后修饰的调控。SUMO化负向调节ARF7的DNA结合活性。
 
 
 
同时,“招募”Aux/IAA(吲哚-3-醋酸)阻遏蛋白IAA3需要ARF7的SUMO化。阻止ARF7的SUMO化扰乱了IAA3的招募和水力模式形成。
 
 
 
▲ Abstract
 
Plants adapt to heterogeneous soil conditions by altering their root architecture. For example, roots branch when in contact with water by using the hydropatterning response. We report that hydropatterning is dependent on auxin response factor ARF7. This transcription factor induces asymmetric expression of its target gene LBD16 in lateral root founder cells. This differential expression pattern is regulated by posttranslational modification of ARF7 with the small ubiquitin-like modifier (SUMO) protein. SUMOylation negatively regulates ARF7 DNA binding activity. ARF7 SUMOylation is required to recruit the Aux/IAA (indole-3-acetic acid) repressor protein IAA3. Blocking ARF7 SUMOylation disrupts IAA3 recruitment and hydropatterning. 
 
 
 
 
物理学 Physics
 
 
 
 
Single-component quasicrystalline nanocrystal superlattices through flexible polygon tiling rule 
 
遵循柔性多边形平铺规则的单组分准晶体纳米晶超晶格
 
▲ 作者:Yasutaka Nagaoka, Hua Zhu, Dennis Eggert, Ou Chen 
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1396
 
 
 
▲ 摘要:
 
产生自单组分胶体构建块的准晶体超晶格(QC-SLs)已被计算机模拟预测出来,但在试验中再现一直面临挑战。
 
 
 
我们发现,10倍QC-SLs能从拥有各向异性分布的截尾四面体量子点自我组织形成。
 
 
 
透射电镜和断层扫描测量使QC-SL实现了从纳米尺度填充到原子尺度定向排列的结构重建。
 
 
 
独特的准晶体顺序带来了“贴瓷砖”概念,即柔性多边形平铺规则。这再现了试验观测。
 
 
 
▲ Abstract
 
Quasicrystalline superlattices (QC-SLs) generated from single-component colloidal building blocks have been predicted by computer simulations but are challenging to reproduce experimentally. We discovered that 10-fold QC-SLs could self-organize from truncated tetrahedral quantum dots with anisotropic patchiness. Transmission electron microscopy and tomography measurements allow structural reconstruction of the QC-SL from the nanoscale packing to the atomic-scale orientation alignments. The unique QC order leads to a tiling concept, the “flexible polygon tiling rule,” that replicates the experimental observations. 
 
 
 
 
 
Magnetic hysteresis up to 80 kelvin in a dysprosium metallocene single-molecule magnet  
 
镝茂金属单分子磁体中磁滞现象达到80开尔文
 
▲ 作者:Fu-Sheng Guo, Benjamin M. Day, Yan-Cong Chen, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1400
 
 
 
▲ 摘要:
 
仅含有一个金属中心的单分子磁体(SMMs)可能代表了基于分子的磁性信息储存材料的尺寸下限。
 
 
 
其现有短板是所有SMMs需要液态氦冷却,才能表现出磁记忆效应。
 
 
 
我们现在报告了一种化学策略来获取镝茂金属阳离子。其在液氮温度以上展现出磁滞现象。
 
 
 
Ueff = 1541波数的磁化反转的有效能垒也得到测量。
 
 
 
针对这种阳离子的TB  =80开尔文的磁屏蔽温度克服了研制在实际温度下发挥作用的纳米磁体设备的重要障碍。
 
 
 
▲ Abstract
 
Single-molecule magnets (SMMs) containingonly one metal center may represent the lower size limit for molecule-basedmagnetic information storage materials. Their current drawback is that all SMMsrequire liquid-helium cooling to show magnetic memory effects. We now report achemical strategy to access the dysprosium metallocene cation, which displaysmagnetic hysteresis above liquid-nitrogen temperatures. An effective energybarrier to reversal of the magnetization of Ueff  = 1541 wave number is alsomeasured. The magnetic blocking temperature of TB  = 80 kelvin for this cationovercomes an essential barrier toward the development of nanomagnet devicesthat function at practical temperatures.
 
 
 
 
天体物理学 Astrophysics
 
 
 
 
Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
 
对质量和木星相当的系外行星WASP-69b扩展氦大气层的地基观测
 
▲ 作者:Lisa Nortmann, Enric Pallé, Michael Salz, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1388
 
 
 
▲ 摘要:
 
由于强烈的恒星辐射,巨大的热气体系外行星会失去部分大气,而这会影响它们的物理和化学演化。
 
 
 
对来自系外行星的大气逃逸进行研究,大部分依靠基于太空的远紫外线区氢赖曼—阿尔法线观测。这受到星际吸收的强烈影响。
 
 
 
利用地基高分辨率光谱,我们探测到质量和木星相当的系外行星WASP-69b凌日期间,在信噪比为18的情况下1083纳米氦三联体的过度吸收。
 
 
 
我们测量了每秒钟若干公里的线蓝移和凌日后吸收,并将其解读为以类似于彗星的形式拖在该行星后面的部分大气的逃逸。
 
 
 
▲ Abstract
 
Hot gas giant exoplanets can lose part of their atmosphere due to strong stellar irradiation, and these losses can affect their physical and chemical evolution. Studies of atmospheric escape from exoplanets have mostly relied on space-based observations of the hydrogen Lyman-α line in the far ultraviolet region, which is strongly affected by interstellar absorption. Using ground-based high-resolution spectroscopy, we detected excess absorption in the helium triplet at 1083 nanometers during the transit of the Saturn-mass exoplanet WASP-69b, at a signal-to-noise ratio of 18. We measured line blueshifts of several kilometers per second and posttransit absorption, which we interpret as the escape of part of the atmosphere trailing behind the planet in comet-like form.
 
 
 
Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
 
来自质量和海王星相当的温暖地外行星扩展大气层的光谱分辨氦吸收
 
▲ 作者:R. Allart1, V. Bourrier, C. Lovis, D. Ehrenreich, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1384
 
 
 
▲ 摘要:
 
恒星加热导致附近地外行星大气层扩展和逃逸。
 
 
 
这些扩展的大气层很难被观测到,因为它们的主要光谱特征——紫外波段的中性氢被星际介质大量吸收。
 
 
 
我们利用地基高分辨率观测结果,探测了正在凌日的质量和海王星相当的温暖地外行星HAT-P-11b中性氦的近红外三联体。
 
 
 
氦特征在两次独立的凌日过程中是可重复的,平均吸收深度为1.08 ± 0.05%。
 
 
 
利用对该行星上层大气的三维模拟对吸收光谱进行的解读表明,它扩展到5个行星半径之外,大尺度高度和氦质量损失率为每秒?3×105克。
 
 
 
▲ Abstract
 
Stellar heating causes atmospheres of close-in exoplanets to expand and escape. These extended atmospheres are difficult to observe because their main spectral signature—neutral hydrogen at ultraviolet wavelengths—is strongly absorbed by interstellar medium. We report the detection of the near-infrared triplet of neutral helium in the transiting warm Neptune-mass exoplanet HAT-P-11b by using ground-based, high-resolution observations. The helium feature is repeatable over two independent transits, with an average absorption depth of 1.08 ± 0.05%. Interpreting absorption spectra with three-dimensional simulations of the planet’s upper atmosphere suggests that it extends beyond 5 planetary radii, with a large-scale height and a helium mass loss rate of ?3 × 105 grams per second. 
 
 
 
 
生态学 Ecology
 
 
 
 
Elevated trawling inside protected areas undermines conservation outcomes in a global fishing hot spot
 
保护区内拖网捕鱼增多逐渐破坏生态保护结果
 
▲ 作者:Manuel Dureuil, Kristina Boerder, Kirsti A. Burnett, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1403
 
 
 
▲ 摘要:
 
海洋保护区(MPAs)正日益被用作保护生物多样性的重要工具。这在欧洲等得到极度开发利用的渔业热点地区尤其重要。
 
 
 
在欧洲,MPAs目前覆盖29%的领海,且对渔获压力和保护结果的影响未知。我们研究了欧盟指定的727个MPAs及其附近的工业拖网捕鱼和敏感指示物种的情况。
 
 
 
研究发现,59%的MPAs出现了商业化的拖网捕鱼,同时平均拖网捕捞强度至少比非保护区高1.4倍。鲨鱼、鳐鱼等敏感物种的丰度在拖网捕鱼情况严重地区下降了69%。
 
 
 
▲ Abstract
 
Marine protected areas (MPAs) are increasingly used as a primary tool to conserve biodiversity. This is particularly relevant in heavily exploited fisheries hot spots such as Europe, where MPAs now cover 29% of territorial waters, with unknown effects on fishing pressure and conservation outcomes. We investigated industrial trawl fishing and sensitive indicator species in and around 727 MPAs designated by the European Union. We found that 59% of MPAs are commercially trawled, and average trawling intensity across MPAs is at least 1.4-fold higher as compared with nonprotected areas. Abundance of sensitive species (sharks, rays, and skates) decreased by 69% in heavily trawled areas. 
 
 
 
 
生物学 Biology
 
 
 
 
NK cell–mediated cytotoxicity contributes to tumor control by a cytostatic drug combination
 
自然杀伤细胞介导细胞毒性促成抑制细胞生长组合药物的肿瘤控制
 
▲ 作者:Marcus Ruscetti, Josef Leibold, Matthew J. Bott1, et al
 
▲ 链接:
 
http://science.sciencemag.org/content/362/6421/1416
 
 
 
▲ 摘要:
 
分子靶向治疗旨在阻碍肿瘤生长所需的细胞自主程序。
 
 
 
我们证实,促分裂原活化蛋白激酶(MAPK)和周期蛋白依赖性激酶4/6抑制剂共同作用,抑制KRAS突变型肺癌细胞扩散,并且同时启动导致肿瘤细胞死亡的自然杀伤(NK)细胞监视程序。
 
 
 
这种药物组合促进了成视网膜细胞瘤(RB)蛋白质介导细胞衰老和免疫调节衰老相关分泌表型的激活(SASP)。
 
 
 
SASP组件肿瘤坏死因子-α和细胞间黏附分子-1是药物治疗肿瘤细胞的NK细胞监视所必需的。
 
 
 
这导致了肿瘤退化以及KRAS突变型肺癌小鼠模型的延长生存。
 
 
 
▲ Abstract
 
Molecularly targeted therapies aim to obstruct cell autonomous programs required for tumor growth. We show that mitogen-activated protein kinase (MAPK) and cyclin-dependent kinase 4/6 inhibitors act in combination to suppress the proliferation of KRAS-mutant lung cancer cells while simultaneously provoking a natural killer (NK) cell surveillance program leading to tumor cell death. The drug combination, but neither agent alone, promotes retinoblastoma (RB) protein-mediated cellular senescence and activation of the immunomodulatory senescence-associated secretory phenotype (SASP). SASP components tumor necrosis factor–α and intercellular adhesion molecule–1 are required for NK cell surveillance of drug-treated tumor cells, which contributes to tumor regressions and prolonged survival in a KRAS-mutant lung cancer mouse model.
 
 
 
(宗华)
 
 
 
 
 
 
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