《科學》（20181026出版）一周論文導讀

Science,VOL 362, ISSUE 6413, 26 OCTOBER 2018

《科學》2018年10月26日第6413期362卷

生物學Biology

The chromatin accessibility landscape of primaryhuman cancers

繪測原發性人類癌症染色質

作者：M. Ryan Corces、Jeffrey M.Granja、Shadi Shams、Bryan H. Louie、Jose A. Seoane、Wanding Zhou、Howard Y. Chang，et al

相關鏈接：

導讀：

研究人員分析了癌症基因組圖譜（TCGA）包含的23種癌症類型的410個腫瘤樣本的全基因組染色質可訪問性，進而對不同癌症相關基因的調控有了新的了解。

研究人員利用ATAC-seq繪測了這23種人類原發性癌症的染色質可及性形貌，並通過識別超過50萬個可及DNA成分，大幅擴展了癌症基因組已知DNA調控成分的範疇。

該研究為癌症的遺傳風險基因座提供了新的線索。這些結果還提示了需要一種系統的方法來理解癌症中的非編碼基因組，以促進診斷和治療。

Abstract

We present the genome-wide chromatin accessibility profiles of 410 tumor samples spanning 23 cancer types from The Cancer Genome Atlas(TCGA). We identify 562,709 transposase-accessible DNA elements that substantially extend the compendium of known cis-regulatory elements. Integration of ATAC-seq (the assay for transposase-accessible chromatin using sequencing) with TCGA multi-omic data identifies a large number of putative distal enhancers that distinguish molecular subtypes of cancers, uncovers specific driving transcription factors via protein-DNA footprints, and nominates long-range gene-regulatory interactions in cancer. These data reveal genetic risk loci of cancer predisposition as active DNA regulatory elements in cancer, identify gene-regulatory interactions underlying cancer immune evasion, and pinpoint noncoding mutations that drive enhancer activation and may affect patient survival. These results suggest a systematic approach to understanding the noncoding genome in cancer to advance diagnosis and therapy.

Transmissionmodes of the mammalian gut microbiota

哺乳動物腸道菌群世系的傳播

作者：Andrew H. Moeller、Taichi A. Suzuki、MeganPhifer-Rixey、Michael W. Nachman

相關鏈接：

導讀：

哺乳動物體內有多種細菌，它們以各種方式影響宿主健康，但人們對細菌在宿主之間傳播的途徑仍知之甚少。

研究人員從兩個野生種群中分離出17個同系交配小鼠世系，並對它們的腸道菌群進行了長達11代的監測，確定了其微生物群的傳播模式。

結果發現，在每一小鼠世系中，個體和群體水平的微生物群組成得到維持，而且在10個世代之後，它們之間的組成仍然維持不同，這表明微生物組主要是以垂直方式繼承的。

此外，某些細菌被證明可能會通過實驗室環境以水平方式進行傳播，這些細菌類型往往會比那些垂直傳播的細菌有更強的毒性，

Abstract

Mammals house a diversity of bacteria that affect health in various ways, but the routes by which bacterial lineages are transmitted between hosts remain poorly understood. We experimentally determined microbiota transmission modes by deriving 17 inbred mouse lines from two wild populations and monitoring their gut microbiotas for up to 11 host generations. Individual- and population-level microbiota compositions were maintained within mouse lines throughout the experiment, indicating predominantly vertical inheritance of the microbiota. However, certain bacterial taxa tended to be exchanged horizontally between mouse lines. Consistent with evolutionary theory, the degree of horizontal transmission predicted bacterial genera with pathogenicre presentatives responsible for human infections and hospitalizations.

The nearshore cradle of early vertebrate diversification

早期脊椎動物多樣化的近岸搖籃

作者：Lauren Sallan、Matt Friedman、Robert S. Sansom、Charlotte M. Bird、Ivan J. Sansom

相關鏈接：

導讀：

原始脊椎動物棲息地受有限的、經常相互矛盾的古生物學數據的影響，常存在爭議和模糊。

研究人員分析了跨越中古生代（4.8億年至3.6億年前）的脊椎動物化石，以及分析其遠古棲息地的環境標誌。

結果顯示，早期脊椎動物的所有主要群體（包括有頜魚和無頜魚）源自近岸的潮間帶和潮下帶環境中，並在這些環境中變得多樣化，其時間跨度為1億年。

而脊椎動物的近岸起源可能與它們的移動需求有關，並影響了其早期化石記錄的結構和多樣性。

Abstract

Ancestral vertebrate habitats are subject to controversy and obscured by limited, often contradictory paleontological data. We assembled fossil vertebrate occurrence and habitat datasets spanning the middle Paleozoic(480 million to 360 million years ago) and found that early vertebrate clades, both jawed and jawless, originated in restricted, shallow intertidal-subtidal environments. Nearshore divergences gave rise to body plans with different dispersal abilities: Robust fishes shifted shoreward, whereas gracile groups moved seaward. Fresh waters were invaded repeatedly, but movement to deeper waters was contingent upon form and short-lived until the later Devonian. Our results contrast with the onshore-offshore trends, reef-centered diversification, and mid-shelf clustering observed for benthic invertebrates. Nearshore origins for vertebrates may be linked to the demands of their mobility and may have influenced the structure of their early fossil record and diversification.

化學/物理學Chemistry/Physics

Ethane/ethylene separationin a metal-organic framework with iron-peroxosites

含鐵過氧化物金屬有機骨架能有效分離乙烷/乙烯

作者：Libo Li、Rui-Biao Lin、Rajamani Krishna、Hao Li、Shengchang Xiang、Hui Wu、Jinping Li、Wei Zhou、BanglinChen

相關鏈接：

導讀：

乙烷與相應的乙烯的分離是化學工業中一個重要、具有挑戰性的能源密集型過程。

研究人員發現了一種新型的微孔金屬—有機框架（MOF），它在聚合物級乙烯的生產中展示了優異的分離特性。

基於微孔材料的氣體分離流程已經顯示是一種有前途的替代傳統乙烯/乙烷分離的方法，但整體效率和成本效益一直受限。

基於含鐵-過氧化物位點及優先與烷烴結合的天然金屬酶的特點，研究人員合成了一種類似的MOF，分離績效評估顯示，新材料有與乙烷結合勝於與乙烯結合的強烈偏好，可在周圍環境的條件下僅用單次分離循環便能生成聚合物級的乙烯（99.99%）。

Abstract

The separation of ethane from its corresponding ethylene is an important, challenging, and energy-intensive process in the chemical industry. Here we report a microporous metal-organic framework, iron(III) peroxide 2,5-dioxido-1,4-benzenedicarboxylate [Fe₂(O₂)(dobdc) (dobdc^4?: 2,5-dioxido-1,4-benzenedicarboxylate)], with iron (Fe)–peroxo sites for the preferential binding of ethane over ethylene and thus highly selective separation of C₂H₆/C₂H₄. Neutron powder diffraction studies and theoretical calculations demonstrate the key role of Fe-peroxo sites for the recognition of ethane. The high performance of Fe₂(O₂)(dobdc) for the ethane/ethylene separation has been validated by gas sorption isotherms, ideal adsorbed solution theory calculations, and simulated and experimental breakthrough curves. Through a fixed-bed column packed with this porous material, polymer-grade ethylene (99.99% pure) can be straight forwardly produced from ethane/ethylene mixtures during the first adsorption cycle, demonstrating the potential of Fe₂(O₂) (dobdc) for this important industrial separation with a low energy cost under ambient conditions.

A room-temperature single-photon source based onstrongly interactingRydberg atoms

基於里德伯原子強相互作用的一種室溫單光子源

作者：Fabian Ripka、HaraldKübler、Robert L?w、Tilman Pfau

相關鏈接：

導讀：

通過將物質的集體量子態轉移到光模式中，可以產生光的定製量子態，但這一過程通常需要超低溫或強約束。

研究人員證明了里德伯原子間的相互作用抑制了多重里德伯狀態激勵和極化子移相造成的相消干涉。

研究人員通過實驗實現了一種四波混合方案演示了一種定製單光子源，在室溫下具有可擴展性和可積性。這種方法在量子信息領域有廣泛的應用前景。

里德伯原子是指價電子被激發到高激發態能級結構由里德伯能級公式描述的原子，俗稱巨原子或胖原子，具有半徑大、結合能小、壽命長等特點。

Abstract

Tailored quantum states of light can be created via a transfer of collective quantum states of matter to light modes. Such collective quantum states emerge in interacting many-body systems if thermal fluctuations are overcome by sufficient interaction strengths. Therefore, ultracold temperatures or strong confinement are typically required. We show that the exaggerated interactions between Rydberg atoms allow for collective quantum states even above room temperature. The emerging Rydberg interactions lead both to suppression of multiple Rydberg state excitations and destructive interference due to polariton dephasing. We experimentally implemented a four-wave mixing scheme to demonstrate an on-demand single-photon source. The combination of glass cell technology, identical atoms, and operation around room temperature promises scalability and integrability. This approach has the potential for various applications in quantum information processing and communication.

Synchrotron radiation from an accelerating light pulse

由加速光脈衝產生的同步輻射

作者：M. Henstridge、C. Pfeiffer、A. Boltasseva、V. M. Shalaev、A. Grbic、R. Merlin

相關鏈接：

導讀：

同步加速器輻射——即電荷沿彎曲路徑運動產生的電磁輻射——是由大型設施定期產生的。在這些設施中，吉電子伏特的電子沿著千米長的環形路徑移動。

研究人員使用超表面來彎曲光線，並演示亞皮秒脈衝產生的同步加速器輻射，該脈衝沿非線性晶體中半徑為100微米的圓弧運動。

在太赫茲頻率範圍內發射的輻射是由脈衝引起的非線性極化引起的。該同步加速器輻射有望推動太赫茲輻射源發展。

Abstract

Synchrotron radiation—namely, electromagnetic radiation produced by charges moving in a curved path—is regularly generated at large-scale facilities where giga–electron volt electrons move along kilometer-long circular paths. We use a metasurface to bend light and demonstrate synchrotron radiation produced by a subpicosecond pulse, which moves along a circular arc of radius 100 micrometers inside a nonlinear crystal. The emitted radiation, in the terahertz frequency range, results from the nonlinear polarization induced by the pulse. The generation of synchrotron radiation from a pulse revolving about a circular trajectory holds promise for the development of on-chip terahertz sources.

能源Energy

Methylammonium-free, high-performance, and stable perovskite solar cells on a planar architecture

無甲基銨、高性能、穩定的平面架構鈣鈦礦太陽能電池

作者：Silver-HamillTurren-Cruz、Anders Hagfeldt、Michael Saliba

相關鏈接：

導讀：

目前，能效大於20%的鈣鈦礦太陽能電池含有溴（導致了能帶隙不夠理想），以及熱不穩定的甲基銨分子。因此，避免溴特別是甲基銨，可以產生更理想的能帶隙和穩定的鈣鈦礦電池。

研究表明，使用銣和銫進行無機陽離子調諧，能使高結晶鈣鈦礦沒有溴或甲基銨。在傳統的平面器件結構中，在電子和空穴傳輸界面上使用聚合物夾層，研究人員證明了新電池能效約為20.35%（穩定），這是無甲基銨鈣鈦礦的最高效率之一。

Abstract

Currently, perovskite solar cells (PSCs) with high performances greater than 20% contain bromine (Br), causing a suboptimal bandgap, and the thermally unstable methylammonium (MA) molecule. Avoiding Br and especially MA can therefore result in more optimal bandgaps and stable perovskites. We show that inorganic cation tuning, using rubidium and cesium, enables highly crystalline formamidinium-based perovskites without Bror MA. On a conventional, planar device architecture, using polymeric interlayers at the electron- and hole-transporting interface, we demonstrate an efficiency of 20.35% (stabilized), one of the highest for MA-free perovskites, with a drastically improved stability reached without the stabilizing influence of mesoporous interlayers. The perovskite is not heated beyond 100°C. Going MA-free is a new direction for perovskites that are inherently stable and compatible with tandems or flexible substrates, which are the main routes commercializing PSCs.

（唐一塵編譯）

注意！微信又雙叒叕更新了......

此次改版後，每個用戶最多可以設置12個常讀訂閱號，這些訂閱號將以往常的大圖封面展示。為了不錯過科學網的推送，請根據以下操作，將我們「星標」吧！

點擊「科學網」進入公號頁面→點擊右上角的···菜單 →選擇「設為星標」，搞定！

關注我們

微信號：sciencenet-cas(←長按複製) 或長按下方二維碼

喜歡這篇文章嗎？立刻分享出去讓更多人知道吧！