10 research outputs found
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
<scp>ReSurveyEurope</scp>: A database of resurveyed vegetation plots in Europe
AbstractAimsWe introduce ReSurveyEurope — a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions.ResultsReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover–abundance classes such as variants of the Braun‐Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020.ConclusionsReSurveyEurope is a new resource to address a wide range of research questions on fine‐scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well‐established European Vegetation Archive (EVA). ReSurveyEurope data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.</jats:sec
The persistent shadow of the supermassive black hole of M 87
In April 2019, the Event Horizon Telescope (EHT) Collaboration reported the first-ever event-horizon-scale images of a black hole, resolving the central compact radio source in the giant elliptical galaxy M 87. These images reveal a ring with a southerly brightness distribution and a diameter of ∼42 μas, consistent with the predicted size and shape of a shadow produced by the gravitationally lensed emission around a supermassive black hole. These results were obtained as part of the April 2017 EHT observation campaign, using a global very long baseline interferometric radio array operating at a wavelength of 1.3 mm. Here, we present results based on the second EHT observing campaign, taking place in April 2018 with an improved array, wider frequency coverage, and increased bandwidth. In particular, the additional baselines provided by the Greenland telescope improved the coverage of the array. Multiyear EHT observations provide independent snapshots of the horizon-scale emission, allowing us to confirm the persistence, size, and shape of the black hole shadow, and constrain the intrinsic structural variability of the accretion flow. We have confirmed the presence of an asymmetric ring structure, brighter in the southwest, with a median diameter of 43.3−3.1+1.5 μas. The diameter of the 2018 ring is remarkably consistent with the diameter obtained from the previous 2017 observations. On the other hand, the position angle of the brightness asymmetry in 2018 is shifted by about 30° relative to 2017. The perennial persistence of the ring and its diameter robustly support the interpretation that the ring is formed by lensed emission surrounding a Kerr black hole with a mass ∼6.5 × 109 M⊙. The significant change in the ring brightness asymmetry implies a spin axis that is more consistent with the position angle of the large-scale jet
First Sagittarius A* Event Horizon Telescope Results. VIII. Physical Interpretation of the Polarized Ring
In a companion paper, we present the first spatially resolved polarized image of Sagittarius A* on event horizon scales, captured using the Event Horizon Telescope, a global very long baseline interferometric array operating at a wavelength of 1.3 mm. Here we interpret this image using both simple analytic models and numerical general relativistic magnetohydrodynamic (GRMHD) simulations. The large spatially resolved linear polarization fraction (24%–28%, peaking at ∼40%) is the most stringent constraint on parameter space, disfavoring models that are too Faraday depolarized. Similar to our studies of M87*, polarimetric constraints reinforce a preference for GRMHD models with dynamically important magnetic fields. Although the spiral morphology of the polarization pattern is known to constrain the spin and inclination angle, the time-variable rotation measure (RM) of Sgr A* (equivalent to ≈46° ± 12° rotation at 228 GHz) limits its present utility as a constraint. If we attribute the RM to internal Faraday rotation, then the motion of accreting material is inferred to be counterclockwise, contrary to inferences based on historical polarized flares, and no model satisfies all polarimetric and total intensity constraints. On the other hand, if we attribute the mean RM to an external Faraday screen, then the motion of accreting material is inferred to be clockwise, and one model passes all applied total intensity and polarimetric constraints: a model with strong magnetic fields, a spin parameter of 0.94, and an inclination of 150°. We discuss how future 345 GHz and dynamical imaging will mitigate our present uncertainties and provide additional constraints on the black hole and its accretion flow
Trimeric Hemibastadin Congener from the Marine Sponge <i>Ianthella basta</i>
The first naturally occurring trimeric hemibastadin congener,
sesquibastadin 1 (<b>1</b>), and the previously reported bastadins
3, 6, 7, 11, and 16 (<b>2</b>–<b>6</b>) were isolated
from the marine sponge <i>Ianthella basta</i>, collected
in Indonesia. The structure of <b>1</b> was elucidated on the
basis of 1D and 2D NMR measurements and by HRMS. Among all the isolated
compounds, the linear sesquibastadin 1 (<b>1</b>) and bastadin
3 (<b>2</b>) showed the strongest inhibition rates for at least
22 protein kinases (IC<sub>50</sub> = 0.1–6.5 μM), while
the macrocyclic bastadins (<b>3</b>–<b>6</b>) demonstrated
a strong cytotoxic potential against the murine lymphoma cell line
L5178Y (IC<sub>50</sub> = 1.5–5.3 μM)
Key Structure–Property Relationships in CO<sub>2</sub> Capture by Supported Alkanolamines
Heterogeneous
interfaces exhibit remarkable material properties resulting from their
structural motifs, the judicious placement of functional chemical
groups, etc. It has been a long-standing challenge to manipulate and
design interface structures at the atomic level to achieve new functionalities.
Here, we demonstrate that by modifying the length of the backbone
in alkanolamines one can control the packing density of organic monolayers
adsorbed on rutile TiO<sub>2</sub> and the interaction strength between
their amine functional group and the substrate. As a result, we observed
strikingly different activities in CO<sub>2</sub> capture by the amine
functional group of different alkanolamines on TiO<sub>2</sub>(110).
Synchrotron photoelectron spectroscopy at near-ambient CO<sub>2</sub> pressures showed that adsorbed 2-amino-1-ethanol (monoethanolamine,
MEA) is inactive, whereas the amine group in 3-amino-1-propanol (3AP)/TiO<sub>2</sub>(110) readily reacts with and captures CO<sub>2</sub>. Our
results suggest that the geometry of the interface plays a decisive
role in the reactivity of adsorbed functionalized organic molecules,
such as solid-supported alkanolamines for CO<sub>2</sub> capture
Synthesis, Characterization, and Nanoencapsulation of Tetrathiatriarylmethyl and Tetrachlorotriarylmethyl (Trityl) Radical DerivativesA Study To Advance Their Applicability as in Vivo EPR Oxygen Sensors
Tissue oxygenation
plays an important role in the pathophysiology
of various diseases and is often a marker of prognosis and therapeutic
response. EPR (ESR) is a suitable noninvasive oximetry technique.
However, to reliably deploy soluble EPR probes as oxygen sensors in
complex biological systems, there is still a need to investigate and
improve their specificity, sensitivity, and stability. We reproducibly
synthesized various derivatives of tetrathiatriarylmethyl and tetrachlorotriarylmethyl
(trityl) radicals. Hydrophilic radicals were investigated in aqueous
solution mimicking physiological conditions by, e.g., variation of
viscosity and ionic strength. Their specificity was satisfactory,
but the oxygen sensitivity was low. To enhance the capability of trityl
radicals as oxygen sensors, encapsulation into oily core nanocapsules
was performed. Thus, different lipophilic triesters were prepared
and characterized in oily solution employing oils typically used in
drug formulations, i.e., middle-chain triglycerides and isopropyl
myristate. Our screening identified the deuterated ethyl ester of
D-TAM (radical <b>13</b>) to be suitable. It had an extremely
narrow single EPR line under anoxic conditions and excellent oxygen
sensitivity. After encapsulation, it retained its oxygen responsiveness
and was protected against reduction by ascorbic acid. These biocompatible
and highly sensitive nanosensors offer great potential for future
EPR oximetry applications in preclinical research
Synthesis of Hydroxyapatite Substrates: Bridging the Gap between Model Surfaces and Enamel
Hydroxyapatite substrates
are common biomaterials, yet samples of natural teeth do not meet
the demands for well-defined, highly reproducible properties. Pellets
of hydroxyapatite were produced via the field assisted sintering technology
(FAST) as well as via pressureless sintering (PLS). The applied synthesis
routes provide samples of very high density (95%–99% of the
crystallographic density) and of very low surface roughness (lower
than 1 nm when averaged per 1 μm<sup>2</sup>). The chemical
composition of the raw material (commercial HAP powder) as well as
the crystalline structure is maintained by the sintering processes.
These specimens can therefore be considered as promising model surfaces
for studies on the interactions of biomaterial with surfaces of biological
relevance, as demonstrated for the adsorption of BSA proteins
Acute kidney disease beyond day 7 after major surgery: a secondary analysis of the EPIS-AKI trial
Purpose: Acute kidney disease (AKD) is a significant health care burden worldwide. However, little is known about this complication after major surgery. Methods: We conducted an international prospective, observational, multi-center study among patients undergoing major surgery. The primary study endpoint was the incidence of AKD (defined as new onset of estimated glomerular filtration rate (eCFR) < 60 ml/min/1.73 m2 present on day 7 or later) among survivors. Secondary endpoints included the relationship between early postoperative acute kidney injury (AKI) (within 72 h after major surgery) and subsequent AKD, the identification of risk factors for AKD, and the rate of chronic kidney disease (CKD) progression in patients with pre-existing CKD. Results: We studied 9510 patients without pre-existing CKD. Of these, 940 (9.9%) developed AKD after 7 days of whom 34.1% experiencing an episode of early postoperative-AKI. Rates of AKD after 7 days significantly increased with the severity (19.1% Kidney Disease Improving Global Outcomes [KDIGO] 1, 24.5% KDIGO2, 34.3% KDIGO3; P < 0.001) and duration (15.5% transient vs 38.3% persistent AKI; P < 0.001) of early postoperative-AKI. Independent risk factors for AKD included early postoperative-AKI, exposure to perioperative nephrotoxic agents, and postoperative pneumonia. Early postoperative-AKI carried an independent odds ratio for AKD of 2.64 (95% confidence interval [CI] 2.21-3.15). Of 663 patients with pre-existing CKD, 42 (6.3%) had worsening CKD at day 90. In patients with CKD and an episode of early AKI, CKD progression occurred in 11.6%. Conclusion: One in ten major surgery patients developed AKD beyond 7 days after surgery, in most cases without an episode of early postoperative-AKI. However, early postoperative-AKI severity and duration were associated with an increased rate of AKD and early postoperative-AKI was strongly associated with AKD independent of all other potential risk factors
Recommended from our members
Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at √s = 8 TeV
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Previous issue date: 2013-09-01
An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb-1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks. © 2013 CERN for the benefit of the CMS collaboration.
CERN, Geneva
Yerevan Physics Institute, Yerevan
Institut für Hochenergiephysik der OeAW, Wien
National Centre for Particle and High Energy Physics, Minsk
Universiteit Antwerpen, Antwerpen
Vrije Universiteit Brussel, Brussel
Université Libre de Bruxelles, Bruxelles
Ghent University, Ghent
Université Catholique de Louvain, Louvain-la-Neuve
Université de Mons, Mons
Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro
Universidade do Estado do Rio de Janeiro, Rio de Janeiro
Universidade Estadual Paulista, São Paulo
Universidade Federal do ABC, São Paulo
Institute for Nuclear Research and Nuclear Energy, Sofia
University of Sofia, Sofia
Institute of High Energy Physics, Beijing
State Key Laboratory of Nuclear Physics and Technology Peking University, Beijing
Universidad de Los Andes, Bogota
Technical University of Split, Split
University of Split, Split
Institute Rudjer Boskovic, Zagreb
University of Cyprus, Nicosia
Charles University, Prague
Academy of Scientific Research and Technology of the Arab Republic of Egypt Egyptian Network of High Energy Physics, Cairo
National Institute of Chemical Physics and Biophysics, Tallinn
Department of Physics University of Helsinki, Helsinki
Helsinki Institute of Physics, Helsinki
Lappeenranta University of Technology, Lappeenranta
DSM/IRFU CEA/Saclay, Gif-sur-Yvette
Laboratoire Leprince-Ringuet, Ecole Polytechnique IN2P3-CNRS, Palaiseau
Institut Pluridisciplinaire Hubert Curien, Universite de Strasbourg, Universite de Haute Alsace Mulh CNRS/IN2P3, Strasbourg
CNRS-IN2P3, Institut de Physique Nucléaire de Lyon Université de Lyon, Université Claude Bernard Lyon 1, Villeurbanne
Institute of High Energy Physics and Informatization Tbilisi State University, Tbilisi
I. Physikalisches Institut RWTH Aachen University, Aachen
III. Physikalisches Institut A RWTH Aachen University, Aachen
III. Physikalisches Institut B RWTH Aachen University, Aachen
Deutsches Elektronen-Synchrotron, Hamburg
University of Hamburg, Hamburg
Institut für Experimentelle Kernphysik, Karlsruhe
Institute of Nuclear and Particle Physics (INPP) NCSR Demokritos, Aghia Paraskevi
University of Athens, Athens
University of Ioánnina, Ioánnina
KFKI Research Institute for Particle and Nuclear Physics, Budapest
Institute of Nuclear Research ATOMKI, Debrecen
University of Debrecen, Debrecen
Panjab University, Chandigarh
University of Delhi, Delhi
Saha Institute of Nuclear Physics, Kolkata
Bhabha Atomic Research Centre, Mumbai
Tata Institute of Fundamental Research - EHEP, Mumbai
Tata Institute of Fundamental Research - HECR, Mumbai
Institute for Research in Fundamental Sciences (IPM), Tehran
INFN Sezione di Bari, Bari
Università di Bari, Bari
Politecnico di Bari, Bari
INFN Sezione di Bologna, Bologna
Università di Bologna, Bologna
INFN Sezione di Catania, Catania
Università di Catania, Catania
INFN Sezione di Firenze, Firenze
Università di Firenze, Firenze
INFN Laboratori Nazionali di Frascati, Frascati
INFN Sezione di Genova, Genova
Università di Genova, Genova
INFN Sezione di Milano-Bicocca, Milano
Università di Milano-Bicocca, Milano
INFN Sezione di Napoli, Napoli
Università di Napoli 'Federico II', Napoli
Università della Basilicata (Potenza), Napoli
Università G. Marconi (Roma), Napoli
INFN Sezione di Padova, Padova
Università di Padova, Padova
Università di Trento (Trento), Padova
INFN Sezione di Pavia, Pavia
Università di Pavia, Pavia
INFN Sezione di Perugia, Perugia
Università di Perugia, Perugia
INFN Sezione di Pisa, Pisa
Università di Pisa, Pisa
Scuola Normale Superiore di Pisa, Pisa
INFN Sezione di Roma, Roma
Università di Roma, Roma
INFN Sezione di Torino, Torino
Università di Torino, Torino
Università del Piemonte Orientale (Novara), Torino
INFN Sezione di Trieste, Trieste
Università di Trieste, Trieste
Kangwon National University, Chunchon
Kyungpook National University, Daegu
Institute for Universe and Elementary Particles Chonnam National University, Kwangju
Korea University, Seoul
University of Seoul, Seoul
Sungkyunkwan University, Suwon
Vilnius University, Vilnius
Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City
Universidad Iberoamericana, Mexico City
Benemerita Universidad Autonoma de Puebla, Puebla
Universidad Autónoma de San Luis Potosí, San Luis Potosí
University of Auckland, Auckland
University of Canterbury, Christchurch
National Centre for Physics Quaid-I-Azam University, Islamabad
National Centre for Nuclear Research, Swierk
Institute of Experimental Physics, Faculty of Physics University of Warsaw, Warsaw
Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa
Joint Institute for Nuclear Research, Dubna
Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg)
Institute for Nuclear Research, Moscow
Institute for Theoretical and Experimental Physics, Moscow
P.N. Lebedev Physical Institute, Moscow
Skobeltsyn Institute of Nuclear Physics Lomonosov Moscow State University, Moscow
State Research Center of Russian Federation Institute for High Energy Physics, Protvino
Faculty of Physics and Vinca Institute of Nuclear Sciences University of Belgrade, Belgrade
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid
Universidad Autónoma de Madrid, Madrid
Universidad de Oviedo, Oviedo
Instituto de Física de Cantabria (IFCA) CSIC-Universidad de Cantabria, Santander
European Organization for Nuclear Research CERN, Geneva
Paul Scherrer Institut, Villigen
Institute for Particle Physics ETH Zurich, Zurich
Universität Zürich, Zurich
National Central University, Chung-Li
National Taiwan University (NTU), Taipei
Chulalongkorn University, Bangkok
Cukurova University, Adana
Physics Department Middle East Technical University, Ankara
Bogazici University, Istanbul
Istanbul Technical University, Istanbul
National Scientific Center Kharkov Institute of Physics and Technology, Kharkov
University of Bristol, Bristol
Rutherford Appleton Laboratory, Didcot
Imperial College, London
Brunel University, Uxbridge
Baylor University, Waco
The University of Alabama, Tuscaloosa
Boston University, Boston
Brown University, Providence
University of California, Davis, Davis
University of California, Los Angeles
University of California, Riverside, Riverside
University of California, San Diego, La Jolla
University of California, Santa Barbara, Santa Barbara
California Institute of Technology, Pasadena
Carnegie Mellon University, Pittsburgh
University of Colorado at Boulder, Boulder
Cornell University, Ithaca
Fairfield University, Fairfield
Fermi National Accelerator Laboratory, Batavia
University of Florida, Gainesville
Florida International University, Miami
Florida State University, Tallahassee
Florida Institute of Technology, Melbourne
University of Illinois at Chicago (UIC), Chicago
The University of Iowa, Iowa City
Johns Hopkins University, Baltimore
The University of Kansas, Lawrence
Kansas State University, Manhattan
Lawrence Livermore National Laboratory, Livermore
University of Maryland, College Park
Massachusetts Institute of Technology, Cambridge
University of Minnesota, Minneapolis
University of Mississippi, Oxford
University of Nebraska-Lincoln, Lincoln
State University of New York at Buffalo, Buffalo
Northeastern University, Boston
Northwestern University, Evanston
University of Notre Dame, Notre Dame
The Ohio State University, Columbus
Princeton University, Princeton
University of Puerto Rico, Mayaguez
Purdue University, West Lafayette
Purdue University Calumet, Hammond
Rice University, Houston
University of Rochester, Rochester
The Rockefeller University, New York
Rutgers The State University of New Jersey, Piscataway
University of Tennessee, Knoxville
Texas A and M University, College Station
Texas Tech University, Lubbock
Vanderbilt University, Nashville
University of Virginia, Charlottesville
Wayne State University, Detroit
University of Wisconsin, Madison
Universidade Estadual Paulista, São Paul