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A remnant planetary core in the hot-Neptune desert 期刊论文
NATURE, 2020, 583 (7814) : 39-+
作者:  David J. Armstrong;  Thé;  o A. Lopez;  Vardan Adibekyan;  Richard A. Booth;  Edward M. Bryant;  Karen A. Collins;  Magali Deleuil;  Alexandre Emsenhuber;  Chelsea X. Huang;  George W. King;  Jorge Lillo-Box;  Jack J. Lissauer;  Elisabeth Matthews;  Olivier Mousis;  Louise D. Nielsen;  Hugh Osborn;  Jon Otegi;  Nuno C. Santos;  ;  rgio G. Sousa;  Keivan G. Stassun;  Dimitri Veras;  Carl Ziegler;  Jack S. Acton;  Jose M. Almenara;  David R. Anderson;  David Barrado;  Susana C. C. Barros;  Daniel Bayliss;  Claudia Belardi;  Francois Bouchy;  ;  sar Briceñ;  o;  Matteo Brogi;  David J. A. Brown;  Matthew R. Burleigh;  Sarah L. Casewell;  Alexander Chaushev;  David R. Ciardi;  Kevin I. Collins;  Knicole D. Coló;  n;  Benjamin F. Cooke;  Ian J. M. Crossfield;  Rodrigo F. Dí;  az;  Elisa Delgado Mena;  Olivier D. S. Demangeon;  Caroline Dorn;  Xavier Dumusque;  Philipp Eigmü;  ller;  Michael Fausnaugh;  Pedro Figueira;  Tianjun Gan;  Siddharth Gandhi;  Samuel Gill;  Erica J. Gonzales;  Michael R. Goad;  Maximilian N. Gü;  nther;  Ravit Helled;  Saeed Hojjatpanah;  Steve B. Howell;  James Jackman;  James S. Jenkins;  Jon M. Jenkins;  Eric L. N. Jensen;  Grant M. Kennedy;  David W. Latham;  Nicholas Law;  Monika Lendl;  Michael Lozovsky;  Andrew W. Mann;  Maximiliano Moyano;  James McCormac;  Farzana Meru;  Christoph Mordasini;  Ares Osborn;  Don Pollacco;  Didier Queloz;  Liam Raynard;  George R. Ricker;  Pamela Rowden;  Alexandre Santerne;  Joshua E. Schlieder;  Sara Seager;  Lizhou Sha;  Thiam-Guan Tan;  Rosanna H. Tilbrook;  Eric Ting;  Sté;  phane Udry;  Roland Vanderspek;  Christopher A. Watson;  Richard G. West;  Paul A. Wilson;  Joshua N. Winn;  Peter Wheatley;  Jesus Noel Villasenor;  Jose I. Vines;  Zhuchang Zhan
收藏  |  浏览/下载:18/0  |  提交时间:2020/07/06

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune '  desert'  (1,2)(a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b(3), which is thought to have an unusually massive core, and recent discoveries such as LTT9779b(4)and NGTS-4b(5), on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune'  s but an anomalously large mass of39.1-2.6+2.7Earth masses and a density of5.2-0.8+0.7grams per cubic centimetre, similar to Earth'  s. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than3.9-0.9+0.8 per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation(6). Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.


Observations of TOI-849b reveal a radius smaller than Neptune'  s but a large mass of about 40 Earth masses, indicating that the planet is the remnant core of a gas giant.


  
HBO1 is required for the maintenance of leukaemia stem cells 期刊论文
NATURE, 2020, 577 (7789) : 266-+
作者:  MacPherson, Laura;  Anokye, Juliana;  Yeung, Miriam M.;  Lam, Enid Y. N.;  Chan, Yih-Chih;  Weng, Chen-Fang;  Yeh, Paul;  Knezevic, Kathy;  Butler, Miriam S.;  Hoegl, Annabelle;  Chan, Kah-Lok;  Burr, Marian L.;  Gearing, Linden J.;  Willson, Tracy;  Liu, Joy;  Choi, Jarny;  Yang, Yuqing;  Bilardi, Rebecca A.;  Falk, Hendrik;  Nghi Nguyen;  Stupple, Paul A.;  Peat, Thomas S.;  Zhang, Ming;  de Silva, Melanie;  Carrasco-Pozo, Catalina;  Avery, Vicky M.;  Khoo, Poh Sim;  Dolezal, Olan;  Dennis, Matthew L.;  Nuttall, Stewart;  Surjadi, Regina;  Newman, Janet;  Ren, Bin;  Leaver, David J.;  Sun, Yuxin;  Baell, Jonathan B.;  Dovey, Oliver;  Vassiliou, George S.;  Grebien, Florian;  Dawson, Sarah-Jane;  Street, Ian P.;  Monahan, Brendon J.;  Burns, Christopher J.;  Choudhary, Chunaram;  Blewitt, Marnie E.;  Voss, Anne K.;  Thomas, Tim;  Dawson, Mark A.
收藏  |  浏览/下载:17/0  |  提交时间:2020/07/03

Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by transcriptional dysregulation that results in a block in differentiation and increased malignant self-renewal. Various epigenetic therapies aimed at reversing these hallmarks of AML have progressed into clinical trials, but most show only modest efficacy owing to an inability to effectively eradicate leukaemia stem cells (LSCs)(1). Here, to specifically identify novel dependencies in LSCs, we screened a bespoke library of small hairpin RNAs that target chromatin regulators in a unique ex vivo mouse model of LSCs. We identify the MYST acetyltransferase HBO1 (also known as KAT7 or MYST2) and several known members of the HBO1 protein complex as critical regulators of LSC maintenance. Using CRISPR domain screening and quantitative mass spectrometry, we identified the histone acetyltransferase domain of HBO1 as being essential in the acetylation of histone H3 at K14. H3 acetylated at K14 (H3K14ac) facilitates the processivity of RNA polymerase II to maintain the high expression of key genes (including Hoxa9 and Hoxa10) that help to sustain the functional properties of LSCs. To leverage this dependency therapeutically, we developed a highly potent small-molecule inhibitor of HBO1 and demonstrate its mode of activity as a competitive analogue of acetyl-CoA. Inhibition of HBO1 phenocopied our genetic data and showed efficacy in a broad range of human cell lines and primary AML cells from patients. These biological, structural and chemical insights into a therapeutic target in AML will enable the clinical translation of these findings.


  
Inner ear sensory system changes as extinct crocodylomorphs transitioned from land to water 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (19) : 10422-10428
作者:  Schwab, Julia A.;  Young, Mark T.;  Neenan, James M.;  Walsh, Stig A.;  Witmer, Lawrence M.;  Herrera, Yanina;  Allain, Ronan;  Brochu, Christopher A.;  Choiniere, Jonah N.;  Clark, James M.;  Dollman, Kathleen N.;  Etches, Steve;  Fritsch, Guido;  Gignac, Paul M.;  Ruebenstahl, Alexander;  Sachs, Sven;  Turner, Alan H.;  Vignaud, Patrick;  Wilberg, Eric W.;  Xu, Xing;  Zanno, Lindsay E.;  Brusatte, Stephen L.
收藏  |  浏览/下载:9/0  |  提交时间:2020/05/13
bony labyrinth  vestibular system  morphology  thalattosuchia  CT scanning  
APOE4 leads to blood-brain barrier dysfunction predicting cognitive decline 期刊论文
NATURE, 2020, 581 (7806) : 70-+
作者:  Doherty, Tiarnan A. S.;  Winchester, Andrew J.;  Macpherson, Stuart;  Johnstone, Duncan N.;  Pareek, Vivek;  Tennyson, Elizabeth M.;  Kosar, Sofiia;  Kosasih, Felix U.;  Anaya, Miguel;  Abdi-Jalebi, Mojtaba;  Andaji-Garmaroudi, Zahra;  Wong, E. Laine;  Madeo, Julien;  Chiang, Yu-Hsien;  Park, Ji-Sang;  Jung, Young-Kwang;  Petoukhoff, Christopher E.;  Divitini, Giorgio;  Man, Michael K. L.;  Ducati, Caterina;  Walsh, Aron;  Midgley, Paul A.;  Dani, Keshav M.;  Stranks, Samuel D.
收藏  |  浏览/下载:25/0  |  提交时间:2020/07/03

Breakdown of the blood-brain barrier in individuals carrying the epsilon 4 allele of the APOE gene, but not the epsilon 3 allele, increases with and predicts cognitive impairment and is independent of amyloid beta or tau pathology.


Vascular contributions to dementia and Alzheimer'  s disease are increasingly recognized(1-6). Recent studies have suggested that breakdown of the blood-brain barrier (BBB) is an early biomarker of human cognitive dysfunction(7), including the early clinical stages of Alzheimer'  s disease(5,8-10). The E4 variant of apolipoprotein E (APOE4), the main susceptibility gene for Alzheimer'  s disease(11-14), leads to accelerated breakdown of the BBB and degeneration of brain capillary pericytes(15-19), which maintain BBB integrity(20-22). It is unclear, however, whether the cerebrovascular effects of APOE4 contribute to cognitive impairment. Here we show that individuals bearing APOE4 (with the epsilon 3/epsilon 4 or epsilon 4/epsilon 4 alleles) are distinguished from those without APOE4 (epsilon 3/epsilon 3) by breakdown of the BBB in the hippocampus and medial temporal lobe. This finding is apparent in cognitively unimpaired APOE4 carriers and more severe in those with cognitive impairment, but is not related to amyloid-beta or tau pathology measured in cerebrospinal fluid or by positron emission tomography(23). High baseline levels of the BBB pericyte injury biomarker soluble PDGFR beta(7,8) in the cerebrospinal fluid predicted future cognitive decline in APOE4 carriers but not in non-carriers, even after controlling for amyloid-beta and tau status, and were correlated with increased activity of the BBB-degrading cyclophilin A-matrix metalloproteinase-9 pathway(19) in cerebrospinal fluid. Our findings suggest that breakdown of the BBB contributes to APOE4-associated cognitive decline independently of Alzheimer'  s disease pathology, and might be a therapeutic target in APOE4 carriers.


  
Radiative absorption enhancements by black carbon controlled by particle-to-particle heterogeneity in composition 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (10) : 5196-5203
作者:  Fierce, Laura;  Onasch, Timothy B.;  Cappa, Christopher D.;  Mazzoleni, Claudio;  China, Swarup;  Bhandari, Janarjan;  Davidovits, Paul;  Al Fischer, D.;  Helgestad, Taylor;  Lambe, Andrew T.;  Sedlacek, Arthur J., III;  Smith, Geoffrey D.;  Wolff, Lindsay
收藏  |  浏览/下载:8/0  |  提交时间:2020/05/13
black carbon  direct radiative forcing  absorption enhancement  aerosol mixing state  
Global airborne sampling reveals a previously unobserved dimethyl sulfide oxidation mechanism in the marine atmosphere 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (9) : 4505-4510
作者:  Veres, Patrick R.;  Neuman, J. Andrew;  Bertram, Timothy H.;  Assaf, Emmanuel;  Wolfe, Glenn M.;  Williamson, Christina J.;  Weinzierl, Bernadett;  Tilmes, Simone;  Thompson, Chelsea R.;  Thames, Alexander B.;  Schroder, Jason C.;  Saiz-Lopez, Alfonso;  Rollins, Andrew W.;  Roberts, James M.;  Price, Derek;  Peischl, Jeff;  Nault, Benjamin A.;  Moller, Kristian H.;  Miller, David O.;  Meinardi, Simone;  Li, Qinyi;  Lamarque, Jean-Francois;  Kupc, Agnieszka;  Kjaergaard, Henrik G.;  Kinnison, Douglas;  Jimenez, Jose L.;  Jernigan, Christopher M.;  Hornbrook, Rebecca S.;  Hills, Alan;  Dollner, Maximilian;  Day, Douglas A.;  Cuevas, Carlos A.;  Campuzano-Jost, Pedro;  Burkholder, James;  Bui, T. Paul;  Brune, William H.;  Brown, Steven S.;  Brock, Charles A.;  Bourgeois, Ilann;  Blake, Donald R.;  Apel, Eric C.;  Ryerson, Thomas B.
收藏  |  浏览/下载:22/0  |  提交时间:2020/05/13
dimethyl sulfide  marine sulfur  autoxidation  marine aerosols  aerosol sulfate  
Video-based AI for beat-to-beat assessment of cardiac function 期刊论文
NATURE, 2020, 580 (7802) : 252-+
作者:  Pleguezuelos-Manzano, Cayetano;  Puschhof, Jens;  Huber, Axel Rosendahl;  van Hoeck, Arne;  Wood, Henry M.;  Nomburg, Jason;  Gurjao, Carino;  Manders, Freek;  Dalmasso, Guillaume;  Stege, Paul B.;  Paganelli, Fernanda L.;  Geurts, Maarten H.;  Beumer, Joep;  Mizutani, Tomohiro;  Miao, Yi;  van der Linden, Reinier;  van der Elst, Stefan;  Garcia, K. Christopher;  Top, Janetta;  Willems, Rob J. L.;  Giannakis, Marios;  Bonnet, Richard;  Quirke, Phil;  Meyerson, Matthew;  Cuppen, Edwin;  van Boxtel, Ruben;  Clevers, Hans
收藏  |  浏览/下载:116/0  |  提交时间:2020/07/03

A video-based deep learning algorithm-EchoNet-Dynamic-accurately identifies subtle changes in ejection fraction and classifies heart failure with reduced ejection fraction using information from multiple cardiac cycles.


Accurate assessment of cardiac function is crucial for the diagnosis of cardiovascular disease(1), screening for cardiotoxicity(2) and decisions regarding the clinical management of patients with a critical illness(3). However, human assessment of cardiac function focuses on a limited sampling of cardiac cycles and has considerable inter-observer variability despite years of training(4,5). Here, to overcome this challenge, we present a video-based deep learning algorithm-EchoNet-Dynamic-that surpasses the performance of human experts in the critical tasks of segmenting the left ventricle, estimating ejection fraction and assessing cardiomyopathy. Trained on echocardiogram videos, our model accurately segments the left ventricle with a Dice similarity coefficient of 0.92, predicts ejection fraction with a mean absolute error of 4.1% and reliably classifies heart failure with reduced ejection fraction (area under the curve of 0.97). In an external dataset from another healthcare system, EchoNet-Dynamic predicts the ejection fraction with a mean absolute error of 6.0% and classifies heart failure with reduced ejection fraction with an area under the curve of 0.96. Prospective evaluation with repeated human measurements confirms that the model has variance that is comparable to or less than that of human experts. By leveraging information across multiple cardiac cycles, our model can rapidly identify subtle changes in ejection fraction, is more reproducible than human evaluation and lays the foundation for precise diagnosis of cardiovascular disease in real time. As a resource to promote further innovation, we also make publicly available a large dataset of 10,030 annotated echocardiogram videos.


  
Initial results from the InSight mission on Mars 期刊论文
NATURE GEOSCIENCE, 2020, 13 (3) : 183-+
作者:  Banerdt, W. Bruce;  Smrekar, Suzanne E.;  Banfield, Don;  Giardini, Domenico;  Golombek, Matthew;  Johnson, Catherine L.;  Lognonne, Philippe;  Spiga, Aymeric;  Spohn, Tilman;  Perrin, Clement;  Staehler, Simon C.;  Antonangeli, Daniele;  Asmar, Sami;  Beghein, Caroline;  Bowles, Neil;  Bozdag, Ebru;  Chi, Peter;  Christensen, Ulrich;  Clinton, John;  Collins, Gareth S.;  Daubar, Ingrid;  Dehant, Veronique;  Drilleau, Melanie;  Fillingim, Matthew;  Folkner, William;  Garcia, Raphael F.;  Garvin, Jim;  Grant, John;  Grott, Matthias;  Grygorczuk, Jerzy;  Hudson, Troy;  Irving, Jessica C. E.;  Kargl, Guenter;  Kawamura, Taichi;  Kedar, Sharon;  King, Scott;  Knapmeyer-Endrun, Brigitte;  Knapmeyer, Martin;  Lemmon, Mark;  Lorenz, Ralph;  Maki, Justin N.;  Margerin, Ludovic;  McLennan, Scott M.;  Michaut, Chloe;  Mimoun, David;  Mittelholz, Anna;  Mocquet, Antoine;  Morgan, Paul;  Mueller, Nils T.;  Murdoch, Naomi;  Nagihara, Seiichi;  Newman, Claire;  Nimmo, Francis;  Panning, Mark;  Pike, W. Thomas;  Plesa, Ana-Catalina;  Rodriguez, Sebastien;  Rodriguez-Manfredi, Jose Antonio;  Russell, Christopher T.;  Schmerr, Nicholas;  Siegler, Matt;  Stanley, Sabine;  Stutzmann, Eleanore;  Teanby, Nicholas;  Tromp, Jeroen;  Van Driel, Martin;  Warner, Nicholas;  Weber, Renee;  Wieczorek, Mark
收藏  |  浏览/下载:24/0  |  提交时间:2020/05/13
Signatures of self-organized criticality in an ultracold atomic gas 期刊论文
NATURE, 2020, 577 (7791) : 481-+
作者:  MacPherson, Laura;  Anokye, Juliana;  Yeung, Miriam M.;  Lam, Enid Y. N.;  Chan, Yih-Chih;  Weng, Chen-Fang;  Yeh, Paul;  Knezevic, Kathy;  Butler, Miriam S.;  Hoegl, Annabelle;  Chan, Kah-Lok;  Burr, Marian L.;  Gearing, Linden J.;  Willson, Tracy;  Liu, Joy;  Choi, Jarny;  Yang, Yuqing;  Bilardi, Rebecca A.;  Falk, Hendrik;  Nghi Nguyen;  Stupple, Paul A.;  Peat, Thomas S.;  Zhang, Ming;  De Silva, Melanie;  Carrasco-Pozo, Catalina;  Avery, Vicky M.;  Khoo, Sim;  Dolezal, Olan;  Dennis, Matthew L.;  Nuttall, Stewart;  Surjadi, Regina;  Newman, Janet;  Ren, Bin;  Leaver, David J.;  Sun, Yuxin;  Baell, Jonathan B.;  Dovey, Oliver;  Vassiliou, George S.;  Grebien, Florian;  Dawson, Sarah-Jane;  Street, Ian P.;  Monahan, Brendon J.;  Burns, Christopher J.;  Choudhary, Chunaram;  Blewitt, Marnie E.;  Voss, Anne K.;  Thomas, Tim;  Dawson, Mark A.
收藏  |  浏览/下载:24/0  |  提交时间:2020/07/03

Self-organized criticality is an elegant explanation of how complex structures emerge and persist throughout nature(1), and why such structures often exhibit similar scale-invariant properties(2-9). Although self-organized criticality is sometimes captured by simple models that feature a critical point as an attractor for the dynamics(10-15), the connection to real-world systems is exceptionally hard to test quantitatively(16-21). Here we observe three key signatures of self-organized criticality in the dynamics of a driven-dissipative gas of ultracold potassium atoms: self-organization to a stationary state that is largely independent of the initial conditions  scale-invariance of the final density characterized by a unique scaling function  and large fluctuations of the number of excited atoms (avalanches) obeying a characteristic power-law distribution. This work establishes a well-controlled platform for investigating self-organization phenomena and non-equilibrium criticality, with experimental access to the underlying microscopic details of the system.


A driven-dissipative gas of ultracold potassium atoms is used to demonstrate three key signatures of self-organized criticality, and provides a system in which the phenomenon can be experimentally tested.


  
Coherent spin manipulation of individual atoms on a surface 期刊论文
SCIENCE, 2019, 366 (6464) : 509-+
作者:  Yang, Kai;  Paul, William;  Phark, Soo-Hyon;  Willke, Philip;  Bae, Yujeong;  Choi, Taeyoung;  Esat, Taner;  Ardavan, Arzhang;  Heinrich, Andreas J.;  Lutz, Christopher P.
收藏  |  浏览/下载:7/0  |  提交时间:2019/11/27