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Science论文导读0707

时间: 2017年07月17日 | 作者: admin | 来源: 未知
1 Multipotent peripheral glial cells generate neuroendocrine cells of the adrenal medulla 【生物】多能周围神经胶质细胞产生肾上腺髓质的神经内分泌细胞 Alessandro Furlan, Vyacheslav Dyachuk, Maria Eleni Kastriti …

1 Multipotent peripheral glial cells generate neuroendocrine cells of the adrenal medulla

【生物】多能周围神经胶质细胞产生肾上腺髓质的神经内分泌细胞

 

Alessandro Furlan, Vyacheslav Dyachuk, Maria Eleni Kastriti…Patrik Ernfors, Igor Adameyko

http://science.sciencemag.org/content/357/6346/eaal3753

 

(导读 卓思琪)肾上腺中,嗜铬细胞是分泌肾上腺素的主要神经内分泌细胞。传统观点认为嗜铬细胞由神经嵴细胞分化而来,而本文发现很多嗜铬细胞是由周围神经胶质细胞——施万细胞前体(Schwann cell precursorsSCPs)分化产生的。SCPs延内脏运动神经迁移至发育中的肾上腺附近后,分化为嗜铬细胞。这一分化过程对肾上腺的发育是重要的,说明周围神经是神经分泌系统发育的干细胞巢。

 

Adrenaline is a fundamental circulating hormone for bodily responses to internal and external stressors. Chromaffin cells of the adrenal medulla (AM) represent the main neuroendocrine adrenergic component and are believed to differentiate from neural crest cells. We demonstrate that large numbers of chromaffin cells arise from peripheral glial stem cells, termed Schwann cell precursors (SCPs). SCPs migrate along the visceral motor nerve to the vicinity of the forming adrenal gland, where they detach from the nerve and form postsynaptic neuroendocrine chromaffin cells. An intricate molecular logic drives two sequential phases of gene expression, one unique for a distinct transient cellular state and another for cell type specification. Subsequently, these programs down-regulate SCP-gene and up-regulate chromaffin cell–gene networks. The AM forms through limited cell expansion and requires the recruitment of numerous SCPs. Thus, peripheral nerves serve as a stem cell niche for neuroendocrine system development.

 

2 Cognitive science in the field: A preschool intervention durably enhances intuitive but not formal mathematics

 

【认知科学】认知科学实地试验:学前干预能持续增强直观数学能力而非正规数学能力

 

Moira R. Dillon, Harini Kannan, Joshua T. Dean, Elizabeth S. Spelke, Esther Duflo

 

http://science.sciencemag.org/content/357/6346/47

 

Many poor children are underprepared for demanding primary school curricula. Research in cognitive science suggests that school achievement could be improved by preschool pedagogy in which numerate adults engage childrens spontaneous, nonsymbolic mathematical concepts. To test this suggestion, we designed and evaluated a game-based preschool curriculum intended to exercise childrens emerging skills in number and geometry. In a randomized field experiment with 1540 children (average age 4.9 years) in 214 Indian preschools, 4 months of math game play yielded marked and enduring improvement on the exercised intuitive abilities, relative to no-treatment and active control conditions. Math-trained children also showed immediate gains on symbolic mathematical skills but displayed no advantage in subsequent learning of the language and concepts of school mathematics.

(导读 董堃)发展中国家的孩子经常会在入学时无法适应高要求的小学课程要求。本研究在214个印度学前班的1540名儿童中开展实地试验,发现与对照组相比,在学前阶段通过游戏方式(五个数学游戏,五个社会认知游戏)锻炼儿童的数字和几何能力,可以持续提升儿童入学后的符号数字能力。

 

 

 

3 Origins of lymphatic and distant metastases in human colorectal cancer

【生物】人类结直肠癌淋巴结转移和远端转移的谱系研究

Kamila Naxerova, Johannes G. Reiter, Elena Brachtel…Stephen J. Elledge, Rakesh K. Jain

http://science.sciencemag.org/content/357/6346/55

 

(导读 卓思琪)传统观点认为肿瘤的局部淋巴结转移是更为致命的远端转移的起始阶段。本文对17个结直肠癌患者213个病理样品中的原位癌细胞、淋巴结转移癌细胞、远端转移癌细胞之间的谱系关系进行了测定,结果发现65%的例子中淋巴转移和远端转移来源于不同谱系的细胞。因此,淋巴结转移可能是,也可能不是结直肠癌远端转移的基础。

 

The spread of cancer cells from primary tumors to regional lymph nodes is often associated with reduced survival. One prevailing model to explain this association posits that fatal, distant metastases are seeded by lymph node metastases. This view provides a mechanistic basis for the TNM staging system and is the rationale for surgical resection of tumor-draining lymph nodes. Here we examine the evolutionary relationship between primary tumor, lymph node, and distant metastases in human colorectal cancer. Studying 213 archival biopsy samples from 17 patients, we used somatic variants in hypermutable DNA regions to reconstruct high-confidence phylogenetic trees. We found that in 65% of cases, lymphatic and distant metastases arose from independent subclones in the primary tumor, whereas in 35% of cases they shared common subclonal origin. Therefore, two different lineage relationships between lymphatic and distant metastases exist in colorectal cancer.

 

4 Quantized electric multipole insulators

【物理】量子化电多极绝缘体

Wladimir A. Benalcazar, B. Andrei Bernevig, Taylor L. Hughes

http://science.sciencemag.org/content/357/6346/61

图片6.png 

导读(田莉)

Berry相给出了晶体中电极化的公式化表述。本研究将这个概念延伸到更高阶的电多极矩,并确定其成立的必要条件和最小化模型。这些系统显示出带隙边界,并在费米面边界表现出部分电荷分区。研究人员引入了一个范式来描述这些绝缘相,并提出了三个拓扑行为可测的实验。研究结果有助于扩展拓扑相的分类。

The Berry phase provides a modern formulation of electric polarization in crystals. We extend this concept to higher electric multipole moments and determine the necessary conditions and minimal models for which the quadrupole and octupole moments are topologically quantized electromagnetic observables. Such systems exhibit gapped boundaries that are themselves lower-dimensional topological phases. Furthermore, they host topologically protected corner states carrying fractional charge, exhibiting fractionalization at the boundary of the boundary.(翻译可能不准确,边界的边界,指的应该是能隙种被填充部分的边界)To characterize these insulating phases of matter, we introduce a paradigm in which “nested” Wilson loops give rise to topological invariants that have been overlooked. We propose three realistic experimental implementations of this topological behavior that can be immediately tested. Our work opens a venue for the expansion of the classification of topological phases of matter.

 

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5 Nanoscale nuclear magnetic resonance with chemical resolution

【物理】具有化学分辨率的纳米级核磁共振

Nabeel Aslam, Matthias Pfender, Philipp Neumann…Junichi Isoya, Jörg Wrachtrup

http://science.sciencemag.org/content/357/6346/67

图片7.png 

导读(田莉)

传统的核磁共振(NMR)要求样品尺寸至少在纳升(10-9L)量级。本研究结合量子存储器和强磁场,通过一个专用量子传感器,在一个20仄升(10-21L)的样品中实现了1H19F NMR谱的化学分辨率位移。为了减弱分子扩散引起的精度影响,研究人员应用同核去耦进行了高分辨率固态NMR测量,使NMR线宽减小了20倍。

Nuclear magnetic resonance (NMR) spectroscopy is a key analytical technique in chemistry, biology, and medicine. However, conventional NMR spectroscopy requires an at least nanoliter-sized sample volume to achieve sufficient signal. We combined the use of a quantum memory and high magnetic fields with a dedicated quantum sensor based on nitrogen vacancy centers in diamond to achieve chemical shift resolution in 1H and 19F NMR spectroscopy of 20-zeptoliter sample volumes. We demonstrate the application of NMR pulse sequences to achieve homonuclear decoupling and spin diffusion measurements. The best measured NMR linewidth of a liquid sample was ~1 part per million, mainly limited by molecular diffusion. To mitigate the influence of diffusion, we performed high-resolution solid-state NMR by applying homonuclear decoupling and achieved a 20-fold narrowing of the NMR linewidth.

 

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6.Femtosecond electron-phonon lock-in by photoemission and x-ray free-electron laser

【物理】利用光电子光谱和X射线自由电子激光对飞秒量级电子-声子进行测量

S. Gerber, S.-L. Yang, D. Zhu…P. S. Kirchmann, Z.-X. Shen

http://science.sciencemag.org/content/357/6346/71

(导读 陈烈裕)铁基材料中超导性的来源一直存在争议。本研究利用X射线衍射和光电子发射光谱定量测量了FeSe中的电子-声子耦合强度,实验结果表明电子关联效应是电子-声子耦合加强的原因。本研究展示了电子-电子和电子-声子的联合效应在铁基材料超导中的重要地位。

The interactions that lead to the emergence of superconductivity in iron-based materials remain a subject of debate. It has been suggested that electron-electron correlations enhance electron-phonon coupling in iron selenide (FeSe) and related pnictides, but direct experimental verification has been lacking. Here we show that the electron-phonon coupling strength in FeSe can be quantified by combining two time-domain experiments into a coherent lock-inmeasurement in the terahertz regime. X-ray diffraction tracks the light-induced femtosecond coherent lattice motion at a single phonon frequency, and photoemission monitors the subsequent coherent changes in the electronic band structure. Comparison with theory reveals a strong enhancement of the coupling strength in FeSe owing to correlation effects. Given that the electron-phonon coupling affects superconductivity exponentially, this enhancement highlights the importance of the cooperative interplay between electron-electron and electron-phonon interactions.

 

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7 Discovery of orbital-selective Cooper pairing in FeSe

【物理】在铁基超导体硒化铁中发现了具有轨道选择性的库珀电子对

P. O. Sprau, A. Kostin, A. Kreisel…B. M. Andersen, J. C. Séamus Davis

http://science.sciencemag.org/content/357/6346/75

图片8.png

 

图片来源:journals.aps.org

(导读:阿金)硒化铁(FeSe)因其异常的非磁性向列相和潜在的高温超导性,一直吸引着学术界的强烈研究兴趣。本研究使用Bogoliubov准粒子干涉成像测量了FeSe三维费米面结构以及相应的超导带隙。结果显示Γ X 带隙表现为各向异性、没有节点、且在动量空间中正交。带隙的排布结构揭示了FeSe中具有轨道选择性的库珀对的存在。

 

 

The superconductor iron selenide (FeSe) is of intense interest owing to its unusual nonmagnetic nematic state and potential for high-temperature superconductivity. But its Cooper pairing mechanism has not been determined. We used Bogoliubov quasiparticle interference imaging to determine the Fermi surface geometry of the electronic bands surrounding the Γ = (0, 0) and X = (π/aFe, 0) points of FeSe and to measure the corresponding superconducting energy gaps. We show that both gaps are extremely anisotropic but nodeless and that they exhibit gap maxima oriented orthogonally in momentum space. Moreover, by implementing a novel technique, we demonstrate that these gaps have opposite sign with respect to each other. This complex gap configuration reveals the existence of orbital-selective Cooper pairing that, in FeSe, is based preferentially on electrons from the dyz orbitals of the iron atoms.

 

8 Evolution of the wheat blast fungus through functional losses in a host specificity determinant

【生物】小麦瘟病菌通过寄主特异性决定因子的功能损失来实现进化

Yoshihiro Inoue, Trinh T. P. Vy, Kentaro Yoshida…Mark Farman, Yukio Tosa

http://science.sciencemag.org/content/357/6346/80

图片9.png 

图片来源:science.sciencemag.org.

(导读 郭思瑶)小麦瘟病最早在巴西出现,后成为严重损害亚洲作物的小麦疫病。本研究鉴定出了小麦瘟病菌中的无毒基因PWT3PWT4,二者的翻译产物可以分别激活小麦抗性基因Rwt3Rwt4以抵御小麦瘟病菌。对巴西小麦种植历史的数据分析显示,rwt3缺陷小麦的广泛培育引发了小麦瘟病菌PWT3基因功能的缺失,从而引发了小麦瘟病的广泛传播。

Wheat blast first emerged in Brazil in the mid-1980s and has recently caused heavy crop losses in Asia. Here we show how this devastating pathogen evolved in Brazil. Genetic analysis of host species determinants in the blast fungus resulted in the cloning of avirulence genes PWT3 and PWT4, whose gene products elicit defense in wheat cultivars containing the corresponding resistance genes Rwt3 and Rwt4. Studies on avirulence and resistance gene distributions, together with historical data on wheat cultivation in Brazil, suggest that wheat blast emerged due to widespread deployment of rwt3 wheat (susceptible to Lolium isolates), followed by the loss of function of PWT3. This implies that the rwt3 wheat served as a springboard for the host jump to common wheat.

 

9 Neurodevelopmental protein Musashi-1 interacts with the Zika genome and promotes viral replication

【生物】神经发育蛋白Musashi-1与寨卡基因组相互作用并促进病毒复制

Pavithra L. Chavali, Lovorka Stojic, Luke W. Meredith…C. Geoffrey Woods, Fanni Gergely

http://science.sciencemag.org/content/357/6346/83

图片10.png 

图片来源:science.sciencemag.org.

(导读:郭思瑶)寨卡病毒倾向于感染神经细胞的原因尚不清楚。科学家发现寨卡病毒科借助神经细胞中的RNA结合蛋白MSI1完成病毒复制,并同时阻断MSI1与其内源性靶标的结合,使神经干细胞功能基因无法表达。MSI1在人类胚胎神经前体细胞中高度表达,其。MSI1的选择性表达可以解释神经细胞为何格外易感寨卡病毒。

A recent outbreak of Zika virus in Brazil has led to a simultaneous increase in reports of neonatal microcephaly. Zika targets cerebral neural precursors, a cell population essential for cortical development, but the cause of this neurotropism remains obscure. Here we report that the neural RNA-binding protein Musashi-1 (MSI1) interacts with the Zika genome and enables viral replication. Zika infection disrupts the binding of MSI1 to its endogenous targets, thereby deregulating expression of factors implicated in neural stem cell function. We further show that MSI1 is highly expressed in neural progenitors of the human embryonic brain and is mutated in individuals with autosomal recessive primary microcephaly. Selective MSI1 expression in neural precursors could therefore explain the exceptional vulnerability of these cells to Zika infection.

 

10 Citywide effects of high-occupancy vehicle restrictions: Evidence from three-in-onein Jakarta

【交通】高承载车辆限制的影响:以雅加达一车三人政策为例

Rema Hanna, Gabriel Kreindler, Benjamin A. Olken

http://science.sciencemag.org/content/357/6346/89

(导读 刘威尔)本研究以雅加达的一车三人(three-in-one政策(要求私人车辆在高峰时期主干道上必须搭乘3人以上)为例,通过手机谷歌地图交通速度数据,调查高承载车辆(high-occupancy vehicle, HOV)相关政策对交通拥堵的影响。早、晚高峰的延误时间在政策废止后分别由2.12.8分钟每千米上升至3.15.3分钟每千米,表明HOV政策能够显著改善交通状况。

Widespread use of single-occupancy cars often leads to traffic congestion. Using anonymized traffic speed data from Android phones collected through Google Maps, we investigated whether high-occupancy vehicle (HOV) policies can combat congestion. We studied Jakarta’s “three-in-onepolicy, which required all private cars on two major roads to carry at least three passengers during peak hours. After the policy was abruptly abandoned in April 2016, delays rose from 2.1 to 3.1 minutes per kilometer (min/km) in the morning peak and from 2.8 to 5.3 min/km in the evening peak. The lifting of the policy led to worse traffic throughout the city, even on roads that had never been restricted or at times when restrictions had never been in place. In short, we find that HOV policies can greatly improve traffic conditions.

 

 

11 Wild emmer genome architecture and diversity elucidate wheat evolution and domestication

【生物】野生二粒小麦基因组结构和多样性阐明小麦进化和驯化过程

Raz Avni, Moran Nave, Omer Barad…Eduard D. Akhunov, Assaf Distelfeld

http://science.sciencemag.org/content/357/6346/93

图片11.png 

图片来源:science.sciencemag.org.

(导读 郭思瑶)小麦是驱动新石器时代向农耕时代转变的基础作物。本研究对小麦野生四倍体祖先二粒小麦的14条染色体进行了基因组组装,并进行了基因成分、基因组结构和遗传多样性分析,从中鉴定出了推进小麦驯化性状发展的关键基因TtBtr。这一基因组组装结果为现代小麦育种优化提供了宝贵资源。

Wheat (Triticum spp.) is one of the founder crops that likely drove the Neolithic transition to sedentary agrarian societies in the Fertile Crescent more than 10,000 years ago. Identifying genetic modifications underlying wheats domestication requires knowledge about the genome of its allo-tetraploid progenitor, wild emmer (T. turgidum ssp. dicoccoides). We report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity. With this fully assembled polyploid wheat genome, we identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes controlling shattering, a key domestication trait. A study of genomic diversity among wild and domesticated accessions revealed genomic regions bearing the signature of selection under domestication. This reference assembly will serve as a resource for accelerating the genome-assisted improvement of modern wheat varieties.