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  • Mechanism of transmembrane signaling by sensor histidine kinases
    Science (IF 34.661) Pub Date : 2017-05-18
    Gushchin, I., Melnikov, I., Polovinkin, V., Ishchenko, A., Yuzhakova, A., Buslaev, P., Bourenkov, G., Grudinin, S., Round, E., Balandin, T., Borshchevskiy, V., Willbold, D., Leonard, G., Büldt, G., Popov, A., Gordeliy, V.

    One of the major and essential classes of transmembrane (TM) receptors, present in all domains of life, is sensor histidine kinases (HKs), parts of two-component signaling systems (TCS). The structural mechanisms of transmembrane signaling by these sensors are poorly understood. We present here crystal structures of the periplasmic sensor domain, the TM domain and the cytoplasmic HAMP domain of the Escherichia coli nitrate/nitrite sensor HK NarQ in the ligand-bound and mutated ligand-free states. The structures reveal that the ligand binding induces significant rearrangements and piston-like shifts of TM helices. The HAMP domain protomers undergo lever-like motions and convert the piston-like motions into helical rotations. Our findings provide the structural framework for complete understanding of TM TCS signaling and for development of antimicrobial treatments targeting TCS.

    更新日期:2017-05-19
  • Resistance to malaria through structural variation of red blood cell invasion receptors
    Science (IF 34.661) Pub Date : 2017-05-18
    Leffler, E. M., Band, G., Busby, G. B. J., Kivinen, K., Le, Q. S., Clarke, G. M., Bojang, K. A., Conway, D. J., Jallow, M., Sisay-Joof, F., Bougouma, E. C., Mangano, V. D., Modiano, D., Sirima, S. B., Achidi, E., Apinjoh, T. O., Marsh, K., Ndila, C. M., Peshu, N., Williams, T. N., Drakeley, C., Manjurano, A., Reyburn, H., Riley, E., Kachala, D., Molyneux, M., Nyirongo, V., Taylor, T., Thornton, N., Tilley, L., Grimsley, S., Drury, E., Stalker, J., Cornelius, V., Hubbart, C., Jeffreys, A. E., Rowlands, K., Rockett, K. A., Spencer, C. C. A., Kwiatkowski, D. P., Malaria Genomic Epidemiology Network

    The malaria parasite Plasmodium falciparum invades human red blood cells via interactions between host and parasite surface proteins. By analyzing genome sequence data from human populations, including 1269 individuals from sub-Saharan Africa, we identify a diverse array of large copy number variants affecting the host invasion receptor genes GYPA and GYPB. We find that a nearby association with severe malaria is explained by a complex structural rearrangement involving the loss of GYPB and gain of two GYPB-A hybrid genes, which encode a serologically distinct blood group antigen known as Dantu. This variant reduces the risk of severe malaria by 40% and has recently risen in frequency in parts of Kenya, yet it appears to be absent from west Africa. These findings link structural variation of red blood cell invasion receptors with natural resistance to severe malaria.

    更新日期:2017-05-19
  • Mitotic chromosome assembly despite nucleosome depletion in Xenopus egg extracts
    Science (IF 34.661) Pub Date : 2017-05-18
    Shintomi, K., Inoue, F., Watanabe, H., Ohsumi, K., Ohsugi, M., Hirano, T.

    The nucleosome is the fundamental structural units of eukaryotic chromatin. During mitosis, duplicated nucleosome fibers are organized into a pair of rod-shaped structures (chromatids) within a mitotic chromosome. However, it remains unclear whether nucleosome assembly is indeed an essential prerequisite for mitotic chromosome assembly. Here, we combined mouse sperm nuclei and Xenopus cell-free egg extracts depleted of the histone chaperone Asf1 and found that chromatid-like structures could be assembled even in the near-absence of nucleosomes. The resultant "nucleosome-depleted" chromatids contained discrete central axes positive for condensins, although they were more fragile than normal nucleosome-containing chromatids. Combinatorial depletion experiments underscored the central importance of condensins in mitotic chromosome assembly, which sheds light on their functional crosstalk with nucleosomes in this process.

    更新日期:2017-05-19
  • Macrophage function in tissue repair and remodeling requires IL-4 or IL-13 with apoptotic cells
    Science (IF 34.661) Pub Date : 2017-05-11
    Bosurgi, L., Cao, Y. G., Cabeza-Cabrerizo, M., Tucci, A., Hughes, L. D., Kong, Y., Weinstein, J. S., Licona-Limon, P., Schmid, E. T., Pelorosso, F., Gagliani, N., Craft, J. E., Flavell, R. A., Ghosh, S., Rothlin, C. V.

    Tissue repair is a subset of a broad repertoire of IL-4/IL-13-dependent host responses during helminth infection. Here, we show that IL-4/IL-13 alone were not sufficient, but IL-4/IL-13 together with apoptotic cells induced the tissue repair program in macrophages. Genetic ablation of sensors of apoptotic cells impaired the proliferation of tissue-resident macrophages and the induction of anti-inflammatory/tissue repair genes in the lung following helminth infection or in the gut following induction of colitis. In contrast, the recognition of apoptotic cells was dispensable for cytokine-dependent induction of pattern recognition receptor, cell adhesion or chemotaxis genes in macrophages. Detection of apoptotic cells can therefore spatially compartmentalize or prevent premature or ectopic activity of pleiotropic, soluble cytokines, such as IL-4/IL-13.

    更新日期:2017-05-16
  • Local amplifiers of IL-4R{alpha}-mediated macrophage activation promote repair in lung and liver
    Science (IF 34.661) Pub Date : 2017-05-11
    Minutti, C. M., Jackson-Jones, L. H., Garcia-Fojeda, B., Knipper, J. A., Sutherland, T. E., Logan, N., Rinqvist, E., Guillamat-Prats, R., Ferenbach, D. A., Artigas, A., Stamme, C., Chroneos, Z. C., Zaiss, D. M., Casals, C., Allen, J. E.

    The type 2 immune response controls helminth infection and maintains tissue homeostasis but can lead to allergy and fibrosis if not adequately regulated. We have discovered local tissue-specific amplifiers of type-2 mediated-macrophage activation. In the lung, surfactant protein A (SP-A) enhanced IL-4-dependent macrophage proliferation and activation, accelerating parasite clearance and reducing pulmonary injury following infection with a lung-migrating helminth. In the peritoneal cavity and liver, C1q enhancement of type 2 macrophage activation was required for liver repair following bacterial infection, but resulted in fibrosis following peritoneal dialysis. IL-4 drives production of these structurally related defense collagens, SP-A and C1q, and the expression of their receptor, myosin 18A. These findings reveal the existence within different tissues of an amplification system needed for local type 2 responses.

    更新日期:2017-05-16
  • A subcellular map of the human proteome
    Science (IF 34.661) Pub Date : 2017-05-11
    Thul, P. J., Akesson, L., Wiking, M., Mahdessian, D., Geladaki, A., Ait Blal, H., Alm, T., Asplund, A., Björk, L., Breckels, L. M., Bäckström, A., Danielsson, F., Fagerberg, L., Fall, J., Gatto, L., Gnann, C., Hober, S., Hjelmare, M., Johansson, F., Lee, S., Lindskog, C., Mulder, J., Mulvey, C. M., Nilsson, P., Oksvold, P., Rockberg, J., Schutten, R., Schwenk, J. M., Sivertsson, A., Sjöstedt, E., Skogs, M., Stadler, C., Sullivan, D. P., Tegel, H., Winsnes, C., Zhang, C., Zwahlen, M., Mardinoglu, A., Ponten, F., von Feilitzen, K., Lilley, K. S., Uhlen, M., Lundberg, E.

    Resolving the spatial distribution of the human proteome at a subcellular level greatly increases our understanding of human biology and disease. Here, we present a comprehensive image-based map of the subcellular protein distribution, the Cell Atlas, built by integrating transcriptomics and antibody-based immunofluorescence microscopy with validation by mass spectrometry. Mapping the in situ localization of 12,003 human proteins at a single-cell level to 30 subcellular structures enabled the definition of 13 major organelle proteomes. Exploration of the proteomes reveals single-cell variations of abundance or spatial distribution, and localization of approximately half of the proteins to multiple compartments. This subcellular map can be used to refine existing protein-protein interaction networks and provides an important resource to deconvolute the highly complex architecture of the human cell.

    更新日期:2017-05-16
  • Dual-comb spectroscopy of water vapor with a free-running semiconductor disk laser
    Science (IF 34.661) Pub Date : 2017-05-11
    Link, S. M., Maas, D. J. H. C., Waldburger, D., Keller, U.

    Dual-comb spectroscopy offers the potential for high accuracy combined with fast data acquisition. Applications are often limited, however, by the complexity of optical comb systems. Here we present dual-comb spectroscopy of water vapor using a substantially simplified single-laser system. Very good spectroscopy measurements with fast sampling rates are achieved with a free-running dual-comb mode-locked semiconductor disk laser. The absolute stability of the optical comb modes is characterized both for free-running operation and with simple microwave stabilization. This approach drastically reduces the complexity for dual-comb spectroscopy. Bandgap engineering to tune the center wavelength from the UV to the mid-IR could optimize frequency combs for specific gas targets, further enabling dual-comb spectroscopy for a wider range of industrial applications.

    更新日期:2017-05-16
  • A maternal-effect selfish genetic element in Caenorhabditis elegans
    Science (IF 34.661) Pub Date : 2017-05-11
    Ben-David, E., Burga, A., Kruglyak, L.

    Selfish genetic elements spread in natural populations and have an important role in genome evolution. We discovered a selfish element causing embryonic lethality in crosses between wild strains of the nematode Caenorhabditis elegans. The element is made up of sup-35, a maternal-effect toxin that kills developing embryos, and pha-1, its zygotically expressed antidote. pha-1 has long been considered essential for pharynx development on the basis of its mutant phenotype, but this phenotype arises from a loss of suppression of sup-35 toxicity. Inactive copies of the sup-35/pha-1 element show high sequence divergence from active copies, and phylogenetic reconstruction suggests that they represent ancestral stages in the evolution of the element. Our results suggest that other essential genes identified by genetic screens may turn out to be components of selfish elements.

    更新日期:2017-05-16
  • Mapping the human DC lineage through the integration of high-dimensional techniques
    Science (IF 34.661) Pub Date : 2017-05-04
    See, P., Dutertre, C.-A., Chen, J., Günther, P., McGovern, N., Irac, S. E., Gunawan, M., Beyer, M., Händler, K., Duan, K., Sumatoh, H. R. B., Ruffin, N., Jouve, M., Gea-Mallorqui, E., Hennekam, R. C. M., Lim, T., Yip, C. C., Wen, M., Malleret, B., Low, I., Shadan, N. B., Fen, C. F. S., Tay, A., Lum, J., Zolezzi, F., Larbi, A., Poidinger, M., Chan, J. K. Y., Chen, Q., Renia, L., Haniffa, M., Benaroch, P., Schlitzer, A., Schultze, J. L., Newell, E. W., Ginhoux, F.

    Dendritic cells (DC) are professional antigen-presenting cells that orchestrate immune responses. The human DC population comprises two main functionally specialized lineages, whose origins and differentiation pathways remain incompletely defined. Here, we combine two high-dimensional technologies—single-cell mRNA sequencing and cytometry by time-of-flight (CyTOF), to identify human blood CD123+CD33+CD45RA+ DC precursors (pre-DC). Pre-DC share surface markers with plasmacytoid DC (pDC) but have distinct functional properties that were previously attributed to pDC. Tracing the differentiation of DC from the bone marrow to the peripheral blood revealed that the pre-DC compartment contains distinct lineage-committed subpopulations, including one early uncommitted CD123high pre-DC subset and two CD45RA+CD123low lineage-committed subsets exhibiting functional differences. The discovery of multiple committed pre-DC populations opens promising new avenues for the therapeutic exploitation of DC subset-specific targeting.

    更新日期:2017-05-16
  • Ring attractor dynamics in the Drosophila central brain
    Science (IF 34.661) Pub Date : 2017-05-04
    Kim, S. S., Rouault, H., Druckmann, S., Jayaraman, V.

    Ring attractors are a class of recurrent networks hypothesized to underlie the representation of heading direction. Such network structures, schematized as a ring of neurons whose connectivity depends on their heading preferences, can sustain a bump-like activity pattern whose location can be updated by continuous shifts along either turn direction. We recently reported that a population of fly neurons represents the animal’s heading via bump-like activity dynamics. We combined two-photon calcium imaging in head-fixed flying flies with optogenetics to overwrite the existing population representation with an artificial one, which was then maintained by the circuit with naturalistic dynamics. A network with local excitation and global inhibition enforces this unique and persistent heading representation. Ring attractor networks have long been invoked in theoretical work; our study provides physiological evidence of their existence and functional architecture.

    更新日期:2017-05-16
  • The complex effects of ocean acidification on the prominent N2-fixing cyanobacterium Trichodesmium
    Science (IF 34.661) Pub Date : 2017-04-27
    Hong, H., Shen, R., Zhang, F., Wen, Z., Chang, S., Lin, W., Kranz, S. A., Luo, Y.-W., Kao, S.-J., Morel, F. M. M., Shi, D.

    Acidification of seawater caused by anthropogenic carbon dioxide (CO2) is anticipated to influence the growth of dinitrogen (N2)–fixing phytoplankton, which contribute a large fraction of primary production in the tropical and subtropical ocean. We found that growth and N2-fixation of the ubiquitous cyanobacterium Trichodesmium decreased under acidified conditions, notwithstanding a beneficial effect of high CO2. Acidification resulted in low cytosolic pH and reduced N2-fixation rates despite elevated nitrogenase concentrations. Low cytosolic pH required increased proton pumping across the thylakoid membrane and elevated adenosine triphosphate production. These requirements were not satisfied under field or experimental iron-limiting conditions, which greatly amplified the negative effect of acidification.

    更新日期:2017-04-28
  • Neandertal and Denisovan DNA from Pleistocene sediments
    Science (IF 34.661) Pub Date : 2017-04-27
    Slon, V., Hopfe, C., Weiss, C. L., Mafessoni, F., de la Rasilla, M., Lalueza-Fox, C., Rosas, A., Soressi, M., Knul, M. V., Miller, R., Stewart, J. R., Derevianko, A. P., Jacobs, Z., Li, B., Roberts, R. G., Shunkov, M. V., de Lumley, H., Perrenoud, C., Gusic, I., Kucan, Z., Rudan, P., Aximu-Petri, A., Essel, E., Nagel, S., Nickel, B., Schmidt, A., Prüfer, K., Kelso, J., Burbano, H. A., Pääbo, S., Meyer, M.

    Although a rich record of Pleistocene human-associated archaeological assemblages exists, the scarcity of hominin fossils often impedes the understanding of which hominins occupied a site. Using targeted enrichment of mitochondrial DNA we show that cave sediments represent a rich source of ancient mammalian DNA that often includes traces of hominin DNA, even at sites and in layers where no hominin remains have been discovered. By automation-assisted screening of numerous sediment samples we detect Neandertal DNA in eight archaeological layers from four caves in Eurasia. In Denisova Cave we retrieved Denisovan DNA in a Middle Pleistocene layer near the bottom of the stratigraphy. Our work opens the possibility to detect the presence of hominin groups at sites and in areas where no skeletal remains are found.

    更新日期:2017-04-28
  • The fading American dream: Trends in absolute income mobility since 1940
    Science (IF 34.661) Pub Date : 2017-04-24
    Chetty, R., Grusky, D., Hell, M., Hendren, N., Manduca, R., Narang, J.

    We estimated rates of "absolute income mobility"—the fraction of children who earn more than their parents—by combining data from U.S. Census and Current Population Survey cross sections with panel data from de-identified tax records. We found that rates of absolute mobility have fallen from approximately 90% for children born in 1940 to 50% for children born in the 1980s. Increasing GDP growth rates alone cannot restore absolute mobility to the rates experienced by children born in the 1940s. However, distributing current GDP growth more equally across income groups as in the 1940 birth cohort would reverse more than 70% of the decline in mobility. These results imply that reviving the "American dream" of high rates of absolute mobility would require economic growth that is shared more broadly across the income distribution.

    更新日期:2017-04-25
  • Documenting decline in U.S. economic mobility
    Science (IF 34.661) Pub Date : 2017-04-24
    Katz, L. F., Krueger, A. B.

    Median incomes stagnate as inequality increases

    更新日期:2017-04-25
  • Bottom-up construction of a superstructure in a porous uranium-organic crystal
    Science (IF 34.661) Pub Date : 2017-04-20
    Li, P., Vermeulen, N. A., Malliakas, C. D., Gomez-Gualdron, D. A., Howarth, A. J., Mehdi, B. L., Dohnalkova, A., Browning, N. D., OKeeffe, M., Farha, O. K.

    Bottom-up construction of highly intricate structures from simple building blocks remains one of the most difficult challenges in chemistry. Here, we report a structurally complex, mesoporous uranium-based metal-organic framework (MOF) made from simple starting components. The structure is comprised of 10 uranium nodes and 7 tricarboxylate ligands (both crystallographically non-equivalent); resulting in a 173.3 angstrom cubic unit cell enclosing 816 uranium nodes and 816 organic linkers—the largest unit cell found for any nonbiological material. The cuboctahedra organize into pentagonal and hexagonal prismatic secondary structures which then form tetrahedral and diamond quaternary topologies with unprecedented complexity. This packing results in the formation of colossal icosidodecahedral and rectified hexakaidecahedral cavities with internal diameters of 5.0 nm and 6.2 nm, respectively—ultimately giving rise to the lowest density MOF reported to date.

    更新日期:2017-04-21
  • Single-proton spin detection by diamond magnetometry
    Science (IF 34.661) Pub Date : 2015-01-08
    Loretz, M., Rosskopf, T., Boss, J. M., Pezzagna, S., Meijer, J., Degen, C. L.

    Extending magnetic resonance imaging to the atomic scale has been a long-standing aspiration, driven by the prospect of directly mapping atomic positions in molecules with three-dimensional spatial resolution. We report detection of individual, isolated proton spins by a nitrogen-vacancy (NV) center in a diamond chip covered by an inorganic salt. The single-proton identity was confirmed by the Zeeman effect and by a quantum coherent rotation of the weakly coupled nuclear spin. Using the hyperfine field of the NV center as an imaging gradient, we determined proton-NV distances of less than 1 nm.

    更新日期:2017-05-16
  • DeepStack: Expert-level artificial intelligence in heads-up no-limit poker
    Science (IF 34.661) Pub Date : 2017-03-02
    Moravcik, M., Schmid, M., Burch, N., Lisy, V., Morrill, D., Bard, N., Davis, T., Waugh, K., Johanson, M., Bowling, M.

    Artificial intelligence has seen several breakthroughs in recent years, with games often serving as milestones. A common feature of these games is that players have perfect information. Poker is the quintessential game of imperfect information, and a longstanding challenge problem in artificial intelligence. We introduce DeepStack, an algorithm for imperfect information settings. It combines recursive reasoning to handle information asymmetry, decomposition to focus computation on the relevant decision, and a form of intuition that is automatically learned from self-play using deep learning. In a study involving 44,000 hands of poker, DeepStack defeated with statistical significance professional poker players in heads-up no-limit Texas hold’em. The approach is theoretically sound and is shown to produce more difficult to exploit strategies than prior approaches.

    更新日期:2017-04-15
  • Stromal Gli2 activity coordinates a niche signaling program for mammary epithelial stem cells
    Science (IF 34.661) Pub Date : 2017-03-09
    Zhao, C., Cai, S., Shin, K., Lim, A., Kalisky, T., Lu, W.-J., Clarke, M. F., Beachy, P. A.

    The stem cell niche is a complex local signaling microenvironment that sustains stem cell activity in organ maintenance and regeneration. The mammary gland niche must support its associated stem cells while also responding to systemic hormonal regulation that triggers pubertal changes. We find that Gli2, the major Hedgehog pathway transcriptional effector, acts within mouse mammary stromal cells to direct a hormone-responsive niche signaling program by activating expression of factors that regulate epithelial stem cells as well as receptors for the mammatrophic hormones estrogen and growth hormone. Whereas prior studies implicate stem cell defects in human disease, this work shows that niche dysfunction may also cause disease, with possible relevance for human disorders and in particular the breast growth pathogenesis associated with combined pituitary hormone deficiency (CPHD).

    更新日期:2017-04-15
  • Anticancer sulfonamides target splicing by inducing RBM39 degradation via recruitment to DCAF15
    Science (IF 34.661) Pub Date : 2017-03-16
    Han, T., Goralski, M., Gaskill, N., Capota, E., Kim, J., Ting, T. C., Xie, Y., Williams, N. S., Nijhawan, D.

    Indisulam is an aryl sulfonamide drug with selective anticancer activity. Its mechanism of action and the basis for its selectivity are unknown. Here we show that indisulam promotes the recruitment of RBM39 (RNA binding motif protein 39) to the CUL4-DCAF15 E3 ubiquitin ligase, leading to RBM39 polyubiquitination and proteasomal degradation. Mutations in RBM39 that prevent its recruitment to CUL4-DCAF15 increase RBM39 stability and confer resistance to indisulam’s cytotoxicity. RBM39 associates with pre-mRNA splicing factors, and inactivation of RBM39 by indisulam causes aberrant pre-mRNA splicing. Many cancer cell lines derived from hematopoietic and lymphoid lineages are sensitive to indisulam and their sensitivity correlates with DCAF15 expression levels. Two other clinically tested sulfanomides, tasisulam and CQS, share the same mechanism of action as indisulam. We propose that DCAF15 expression may be a useful biomarker to guide clinical trials of this class of drugs, which we refer to as SPLAMs (SPLicing inhibitor sulfonAMides).

    更新日期:2017-04-15
  • Coupling between distant biofilms and emergence of nutrient time-sharing
    Science (IF 34.661) Pub Date : 2017-04-06
    Liu, J., Martinez-Corral, R., Prindle, A., Lee, D.-y. D., Larkin, J., Gabalda-Sagarra, M., Garcia-Ojalvo, J., Süel, G. M.

    Bacteria within communities can interact to organize their behavior. It remains unclear whether such interactions extend beyond a single community to coordinate the behavior of distant populations. We discovered that two Bacillus subtilis biofilm communities undergoing metabolic oscillations become coupled through electrical signaling and synchronize their growth dynamics. Coupling increases competition by also synchronizing demand for limited nutrients. As predicted by mathematical modeling, we confirm that biofilms resolve this conflict by switching from in-phase to anti-phase oscillations. This results in time-sharing behavior where each community takes turns consuming nutrients. Time-sharing enables biofilms to counterintuitively increase growth under reduced nutrient supply. Distant biofilms can thus coordinate their behavior to resolve nutrient competition through time-sharing, a strategy used in engineered systems to allocate limited resources.

    更新日期:2017-04-15
  • Self-organized Notch dynamics generate stereotyped sensory organ patterns in Drosophila
    Science (IF 34.661) Pub Date : 2017-04-06
    Corson, F., Couturier, L., Rouault, H., Mazouni, K., Schweisguth, F.

    The emergence of spatial patterns in developing multicellular organisms relies on positional cues and cell-cell communication. Drosophila sensory organs have informed a paradigm where these operate in two distinct steps: prepattern factors drive localized proneural activity, then Notch-mediated lateral inhibition singles out neural precursors. Here we show that self-organization through Notch signaling also organizes the proneural stripes that resolve into rows of sensory bristles on the fly thorax. Patterning, initiated by a gradient of Delta ligand expression, progresses through inhibitory signaling between and within stripes. Thus Notch signaling can support self-organized tissue patterning as a prepattern is transduced by cell-cell interactions into a refined arrangement of cellular fates.

    更新日期:2017-04-15
  • Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean
    Science (IF 34.661) Pub Date : 2017-04-06
    Polyakov, I. V., Pnyushkov, A. V., Alkire, M. B., Ashik, I. M., Baumann, T. M., Carmack, E. C., Goszczko, I., Guthrie, J., Ivanov, V. V., Kanzow, T., Krishfield, R., Kwok, R., Sundfjord, A., Morison, J., Rember, R., Yulin, A.

    Arctic sea-ice loss is a leading indicator of climate change and can be attributed, in large part, to atmospheric forcing. Here, we show that recent ice reductions, weakening of the halocline, and shoaling of intermediate-depth Atlantic Water layer in the eastern Eurasian Basin have increased winter ventilation in the ocean interior, making this region structurally similar to that of the western Eurasian Basin. The associated enhanced release of oceanic heat has reduced winter sea-ice formation at a rate now comparable to losses from atmospheric thermodynamic forcing, thus explaining the recent reduction in sea-ice cover in the eastern Eurasian Basin. This encroaching "atlantification" of the Eurasian Basin represents an essential step toward a new Arctic climate state, with a substantially greater role for Atlantic inflows.

    更新日期:2017-04-15
  • Control of muscle formation by the fusogenic micropeptide myomixer
    Science (IF 34.661) Pub Date : 2017-04-06
    Bi, P., Ramirez-Martinez, A., Li, H., Cannavino, J., McAnally, J. R., Shelton, J. M., Sanchez-Ortiz, E., Bassel-Duby, R., Olson, E. N.

    Skeletal muscle formation occurs through fusion of myoblasts to form multi-nucleated myofibers. From a genome-wide CRISPR loss-of-function screen for genes required for myoblast fusion and myogenesis, we discovered an 84-amino acid muscle-specific peptide that we call Myomixer. Myomixer expression coincides with myoblast differentiation and is essential for fusion and skeletal muscle formation during embryogenesis. Myomixer localizes to the plasma membrane where it promotes myoblast fusion and associates with Myomaker, a fusogenic membrane protein. Myomixer together with Myomaker can also induce fibroblast–fibroblast fusion and fibroblast–myoblast fusion. We conclude that the Myomixer-Myomaker pair controls the critical step in myofiber formation during muscle development.

    更新日期:2017-04-15
  • Ephrin B1-mediated repulsion and signaling control germinal center T cell territoriality and function
    Science (IF 34.661) Pub Date : 2017-04-13
    Lu, P., Shih, C., Qi, H.

    Follicular T-helper (TFH) cells orchestrate the germinal center (GC) reaction locally. Local mechanisms regulating their dynamics and helper functions are not well defined. Here we found that GC-expressed Ephrin B1 (EFNB1) repulsively inhibited T cell to B cell adhesion and GC TFH retention by signaling through TFH-expressed EPHB6 receptor. At the same time, EFNB1 promoted IL-21 production from GC TFH cells by signaling predominantly through EPHB4. Consequently, EFNB1-null GCs were associated with defective production of plasma cells despite harboring excessive TFH cells. In a competitive GC reaction EFNB1-deficient B cells more efficiently interacted with TFH cells and produced more bone-marrow plasma cells, likely as a result of gaining more contact-dependent help. Our results reveal a contact-dependent repulsive guidance system that controls GC TFH dynamics and effector functions locally.

    更新日期:2017-05-16
  • Decarboxylative borylation
    Science (IF 34.661) Pub Date : 2017-04-13
    Li, C., Wang, J., Barton, L. M., Yu, S., Tian, M., Peters, D. S., Kumar, M., Yu, A. W., Johnson, K. A., Chatterjee, A. K., Yan, M., Baran, P. S.

    The widespread use of alkyl boronic acids and esters is frequently hampered by the challenges associated with their preparation. Herein we describe a simple and practical method to rapidly access densely functionalized alkyl boronate esters from abundant carboxylic substituents. This broad-scope Ni-catalyzed reaction uses the same activating principle as amide bond formation to replace a carboxylic acid with a boronate ester. Application to peptides allowed expedient preparations of α-amino boronic acids, often with high stereoselectivity, facilitating the synthesis of both FDA approved alkyl boronic acid drugs (Velcade and Ninlaro) as well as a boronic acid version of the iconic antibiotic vancomycin. The reaction also enabled the discovery and extensive biological characterization of potent elastase inhibitors which may have a strategic advantage due to their covalent-reversible binding properties.

    更新日期:2017-05-16
  • Water harvesting from air with metal-organic frameworks powered by natural sunlight
    Science (IF 34.661) Pub Date : 2017-04-13
    Kim, H., Yang, S., Rao, S. R., Narayanan, S., Kapustin, E. A., Furukawa, H., Umans, A. S., Yaghi, O. M., Wang, E. N.

    Atmospheric water is a resource equivalent to ~10% of all fresh water in lakes on Earth. However, an efficient process for capturing and delivering water from air, especially at low humidity levels (down to 20%), has not been developed. We report the design and demonstration of a device based on porous metal-organic framework-801 [Zr6O4(OH)4(fumarate)6] that captures water from the atmosphere at ambient conditions using low-grade heat from natural sunlight below one sun (1 kW per square meter). This device is capable of harvesting 2.8 liters of water per kilogram of MOF daily at relative humidity levels as low as 20%, and requires no additional input of energy.

    更新日期:2017-04-15
  • Nucleic acid detection with CRISPR-Cas13a/C2c2
    Science (IF 34.661) Pub Date : 2017-04-13
    Gootenberg, J. S., Abudayyeh, O. O., Lee, J. W., Essletzbichler, P., Dy, A. J., Joung, J., Verdine, V., Donghia, N., Daringer, N. M., Freije, C. A., Myhrvold, C., Bhattacharyya, R. P., Livny, J., Regev, A., Koonin, E. V., Hung, D. T., Sabeti, P. C., Collins, J. J., Zhang, F.

    Rapid, inexpensive, and sensitive nucleic acid detection may aid point-of-care pathogen detection, genotyping, and disease monitoring. The RNA-guided, RNA-targeting CRISPR effector Cas13a (previously known as C2c2) exhibits a "collateral effect" of promiscuous RNAse activity upon target recognition. We combine the collateral effect of Cas13a with isothermal amplification to establish a CRISPR-based diagnostic (CRISPR-Dx), providing rapid DNA or RNA detection with attomolar sensitivity and single-base mismatch specificity. We use this Cas13a-based molecular detection platform, termed SHERLOCK (Specific High Sensitivity Enzymatic Reporter UnLOCKing), to detect specific strains of Zika and Dengue virus, distinguish pathogenic bacteria, genotype human DNA, and identify cell-free tumor DNA mutations. Furthermore, SHERLOCK reaction reagents can be lyophilized for cold-chain independence and long-term storage, and readily reconstituted on paper for field applications.

    更新日期:2017-04-15
  • [Working Life] Skiing for science
    Science (IF 34.661) Pub Date : 2017-04-14
    Daniel T. Blumstein

    Author: Daniel T. Blumstein

    更新日期:2017-04-14
  • [Business Office Feature] Webinar | Translational applications in exosome research: From biomarker discovery to drug delivery
    Science (IF 34.661) Pub Date : 2017-04-14
    Elena V. Batrakova, Richard Jones, Anne Lynn S. Chang

    Exosomes—small, membrane-derived extracellular vesicles capable of carrying diverse biological cargo including proteins and microRNAs—have been found in a broad range of biological fluids and appear to be predominantly involved in cell-to-cell communication. Their natural characteristics make them uniquely suited for research and clinical applications, including as biomarkers both for diseases and for intrinsic biological activity. In fact, exosomes have been postulated to mediate the biological cross-talk that takes place between tumors and their surrounding environment that drives those tumors toward a metastatic state. In addition, exosomes are being co-opted as a treatment modality and have been modified through their parental cells to express a targeting moiety or marker tag on their surface. They can also be manipulated to carry drug formulations that can be applied to the treatment of a wide variety of disorders, such as cancer and various infectious, cardiovascular, and neurodegenerative diseases.View the Webinar

    更新日期:2017-04-14
  • [New Products] New Products
    Science (IF 34.661) Pub Date : 2017-04-14

    A weekly roundup of information on newly offered instrumentation, apparatus, and laboratory materials of potential interest to researchers.

    更新日期:2017-04-14
  • [Report] Crystal structure of the overlapping dinucleosome composed of hexasome and octasome
    Science (IF 34.661) Pub Date : 2017-04-14
    Daiki Kato, Akihisa Osakabe, Yasuhiro Arimura, Yuka Mizukami, Naoki Horikoshi, Kazumi Saikusa, Satoko Akashi, Yoshifumi Nishimura, Sam-Yong Park, Jumpei Nogami, Kazumitsu Maehara, Yasuyuki Ohkawa, Atsushi Matsumoto, Hidetoshi Kono, Rintaro Inoue, Masaaki Sugiyama, Hitoshi Kurumizaka

    Nucleosomes are dynamic entities that are repositioned along DNA by chromatin remodeling processes. A nucleosome repositioned by the switch-sucrose nonfermentable (SWI/SNF) remodeler collides with a neighbor and forms the intermediate “overlapping dinucleosome.” Here, we report the crystal structure of the overlapping dinucleosome, in which two nucleosomes are associated, at 3.14-angstrom resolution. In the overlapping dinucleosome structure, the unusual “hexasome” nucleosome, composed of the histone hexamer lacking one H2A-H2B dimer from the conventional histone octamer, contacts the canonical “octasome” nucleosome, and they intimately associate. Consequently, about 250 base pairs of DNA are left-handedly wrapped in three turns, without a linker DNA segment between the hexasome and octasome moieties. The overlapping dinucleosome structure may provide important information to understand how nucleosome repositioning occurs during the chromatin remodeling process.

    更新日期:2017-04-14
  • [Report] Landscape of immunogenic tumor antigens in successful immunotherapy of virally induced epithelial cancer
    Science (IF 34.661) Pub Date : 2017-04-14
    Sanja Stevanović, Anna Pasetto, Sarah R. Helman, Jared J. Gartner, Todd D. Prickett, Bryan Howie, Harlan S. Robins, Paul F. Robbins, Christopher A. Klebanoff, Steven A. Rosenberg, Christian S. Hinrichs

    Immunotherapy has clinical activity in certain virally associated cancers. However, the tumor antigens targeted in successful treatments remain poorly defined. We used a personalized immunogenomic approach to elucidate the global landscape of antitumor T cell responses in complete regression of human papillomavirus–associated metastatic cervical cancer after tumor-infiltrating adoptive T cell therapy. Remarkably, immunodominant T cell reactivities were directed against mutated neoantigens or a cancer germline antigen, rather than canonical viral antigens. T cells targeting viral tumor antigens did not display preferential in vivo expansion. Both viral and nonviral tumor antigen–specific T cells resided predominantly in the programmed cell death 1 (PD-1)–expressing T cell compartment, which suggests that PD-1 blockade may unleash diverse antitumor T cell reactivities. These findings suggest a new paradigm of targeting nonviral antigens in immunotherapy of virally associated cancers.

    更新日期:2017-04-14
  • [Report] Nanoscale-length control of the flagellar driveshaft requires hitting the tethered outer membrane
    Science (IF 34.661) Pub Date : 2017-04-14
    Eli J. Cohen, Josie L. Ferreira, Mark S. Ladinsky, Morgan Beeby, Kelly T. Hughes

    The bacterial flagellum exemplifies a system where even small deviations from the highly regulated flagellar assembly process can abolish motility and cause negative physiological outcomes. Consequently, bacteria have evolved elegant and robust regulatory mechanisms to ensure that flagellar morphogenesis follows a defined path, with each component self-assembling to predetermined dimensions. The flagellar rod acts as a driveshaft to transmit torque from the cytoplasmic rotor to the external filament. The rod self-assembles to a defined length of ~25 nanometers. Here, we provide evidence that rod length is limited by the width of the periplasmic space between the inner and outer membranes. The length of Braun's lipoprotein determines periplasmic width by tethering the outer membrane to the peptidoglycan layer.

    更新日期:2017-04-14
  • [Report] Architecture of a transcribing-translating expressome
    Science (IF 34.661) Pub Date : 2017-04-14
    R. Kohler, R. A. Mooney, D. J. Mills, R. Landick, P. Cramer

    DNA transcription is functionally coupled to messenger RNA (mRNA) translation in bacteria, but how this is achieved remains unclear. Here we show that RNA polymerase (RNAP) and the ribosome of Escherichia coli can form a defined transcribing and translating “expressome” complex. The cryo–electron microscopic structure of the expressome reveals continuous protection of ~30 nucleotides of mRNA extending from the RNAP active center to the ribosome decoding center. The RNAP-ribosome interface includes the RNAP subunit α carboxyl-terminal domain, which is required for RNAP-ribosome interaction in vitro and for pronounced cell growth defects upon translation inhibition in vivo, consistent with its function in transcription-translation coupling. The expressome structure can only form during transcription elongation and explains how translation can prevent transcriptional pausing, backtracking, and termination.

    更新日期:2017-04-14
  • [Report] Single-cell whole-genome analyses by Linear Amplification via Transposon Insertion (LIANTI)
    Science (IF 34.661) Pub Date : 2017-04-14
    Chongyi Chen, Dong Xing, Longzhi Tan, Heng Li, Guangyu Zhou, Lei Huang, X. Sunney Xie

    Single-cell genomics is important for biology and medicine. However, current whole-genome amplification (WGA) methods are limited by low accuracy of copy-number variation (CNV) detection and low amplification fidelity. Here we report an improved single-cell WGA method, Linear Amplification via Transposon Insertion (LIANTI), which outperforms existing methods, enabling micro-CNV detection with kilobase resolution. This allowed direct observation of stochastic firing of DNA replication origins, which differs from cell to cell. We also show that the predominant cytosine-to-thymine mutations observed in single-cell genomics often arise from the artifact of cytosine deamination upon cell lysis. However, identifying single-nucleotide variations (SNVs) can be accomplished by sequencing kindred cells. We determined the spectrum of SNVs in a single human cell after ultraviolet radiation, revealing their nonrandom genome-wide distribution.

    更新日期:2017-04-14
  • [Report] The preprophase band of microtubules controls the robustness of division orientation in plants
    Science (IF 34.661) Pub Date : 2017-04-14
    Estelle Schaefer, Katia Belcram, Magalie Uyttewaal, Yann Duroc, Magali Goussot, David Legland, Elise Laruelle, Marie-Ludivine de Tauzia-Moreau, Martine Pastuglia, David Bouchez

    Controlling cell division plane orientation is essential for morphogenesis in multicellular organisms. In plant cells, the future cortical division plane is marked before mitotic entry by the preprophase band (PPB). Here, we characterized an Arabidopsis trm (TON1 Recruiting Motif) mutant that impairs PPB formation but does not affect interphase microtubules. Unexpectedly, PPB disruption neither abolished the capacity of root cells to define a cortical division zone nor induced aberrant cell division patterns but rather caused a loss of precision in cell division orientation. Our results advocate for a reassessment of PPB function and division plane determination in plants and show that a main output of this microtubule array is to limit spindle rotations in order to increase the robustness of cell division.

    更新日期:2017-04-14
  • [Report] Semantics derived automatically from language corpora contain human-like biases
    Science (IF 34.661) Pub Date : 2017-04-14
    Aylin Caliskan, Joanna J. Bryson, Arvind Narayanan

    Machine learning is a means to derive artificial intelligence by discovering patterns in existing data. Here, we show that applying machine learning to ordinary human language results in human-like semantic biases. We replicated a spectrum of known biases, as measured by the Implicit Association Test, using a widely used, purely statistical machine-learning model trained on a standard corpus of text from the World Wide Web. Our results indicate that text corpora contain recoverable and accurate imprints of our historic biases, whether morally neutral as toward insects or flowers, problematic as toward race or gender, or even simply veridical, reflecting the status quo distribution of gender with respect to careers or first names. Our methods hold promise for identifying and addressing sources of bias in culture, including technology.

    更新日期:2017-04-14
  • [Report] The impact of hunting on tropical mammal and bird populations
    Science (IF 34.661) Pub Date : 2017-04-14
    A. Benítez-López, R. Alkemade, A. M. Schipper, D. J. Ingram, P. A. Verweij, J. A. J. Eikelboom, M. A. J. Huijbregts

    Hunting is a major driver of biodiversity loss, but a systematic large-scale estimate of hunting-induced defaunation is lacking. We synthesized 176 studies to quantify hunting-induced declines of mammal and bird populations across the tropics. Bird and mammal abundances declined by 58% (25 to 76%) and by 83% (72 to 90%) in hunted compared with unhunted areas. Bird and mammal populations were depleted within 7 and 40 kilometers from hunters’ access points (roads and settlements). Additionally, hunting pressure was higher in areas with better accessibility to major towns where wild meat could be traded. Mammal population densities were lower outside protected areas, particularly because of commercial hunting. Strategies to sustainably manage wild meat hunting in both protected and unprotected tropical ecosystems are urgently needed to avoid further defaunation.

    更新日期:2017-04-14
  • [Report] Enhancement of Zika virus pathogenesis by preexisting antiflavivirus immunity
    Science (IF 34.661) Pub Date : 2017-04-14
    Susana V. Bardina, Paul Bunduc, Shashank Tripathi, James Duehr, Justin J. Frere, Julia A. Brown, Raffael Nachbagauer, Gregory A. Foster, David Krysztof, Domenico Tortorella, Susan L. Stramer, Adolfo García-Sastre, Florian Krammer, Jean K. Lim

    Zika virus (ZIKV) is spreading rapidly into regions around the world where other flaviviruses, such as dengue virus (DENV) and West Nile virus (WNV), are endemic. Antibody-dependent enhancement has been implicated in more severe forms of flavivirus disease, but whether this also applies to ZIKV infection is unclear. Using convalescent plasma from DENV- and WNV-infected individuals, we found substantial enhancement of ZIKV infection in vitro that was mediated through immunoglobulin G engagement of Fcγ receptors. Administration of DENV- or WNV-convalescent plasma into ZIKV-susceptible mice resulted in increased morbidity—including fever, viremia, and viral loads in spinal cord and testes—and increased mortality. Antibody-dependent enhancement may explain the severe disease manifestations associated with recent ZIKV outbreaks and highlights the need to exert great caution when designing flavivirus vaccines.

    更新日期:2017-04-14
  • [Report] Synthesis of a carbon nanobelt
    Science (IF 34.661) Pub Date : 2017-04-14
    Guillaume Povie, Yasutomo Segawa, Taishi Nishihara, Yuhei Miyauchi, Kenichiro Itami

    The synthesis of a carbon nanobelt, comprising a closed loop of fully fused edge-sharing benzene rings, has been an elusive goal in organic chemistry for more than 60 years. Here we report the synthesis of one such compound through iterative Wittig reactions followed by a nickel-mediated aryl-aryl coupling reaction. The cylindrical shape of its belt structure was confirmed by x-ray crystallography, and its fundamental optoelectronic properties were elucidated by ultraviolet-visible absorption, fluorescence, and Raman spectroscopic studies, as well as theoretical calculations. This molecule could potentially serve as a seed for the preparation of structurally well-defined carbon nanotubes.

    更新日期:2017-04-14
  • [Report] Colloidally prepared La-doped BaSnO3 electrodes for efficient, photostable perovskite solar cells
    Science (IF 34.661) Pub Date : 2017-04-14
    Seong Sik Shin, Eun Joo Yeom, Woon Seok Yang, Seyoon Hur, Min Gyu Kim, Jino Im, Jangwon Seo, Jun Hong Noh, Sang Il Seok

    Perovskite solar cells (PSCs) exceeding a power conversion efficiency (PCE) of 20% have mainly been demonstrated by using mesoporous titanium dioxide (mp-TiO2) as an electron-transporting layer. However, TiO2 can reduce the stability of PSCs under illumination (including ultraviolet light). Lanthanum (La)–doped BaSnO3 (LBSO) perovskite would be an ideal replacement given its electron mobility and electronic structure, but LBSO cannot be synthesized as well-dispersible fine particles or crystallized below 500°C. We report a superoxide colloidal solution route for preparing a LBSO electrode under very mild conditions (below 300°C). The PSCs fabricated with LBSO and methylammonium lead iodide (MAPbI3) show a steady-state power conversion efficiency of 21.2%, versus 19.7% for a mp-TiO2 device. The LBSO-based PSCs could retain 93% of their initial performance after 1000 hours of full-Sun illumination.

    更新日期:2017-04-14
  • [Report] Imaging the distribution of transient viscosity after the 2016 Mw 7.1 Kumamoto earthquake
    Science (IF 34.661) Pub Date : 2017-04-14
    James D. P. Moore, Hang Yu, Chi-Hsien Tang, Teng Wang, Sylvain Barbot, Dongju Peng, Sagar Masuti, Justin Dauwels, Ya-Ju Hsu, Valère Lambert, Priyamvada Nanjundiah, Shengji Wei, Eric Lindsey, Lujia Feng, Bunichiro Shibazaki

    The deformation of mantle and crustal rocks in response to stress plays a crucial role in the distribution of seismic and volcanic hazards, controlling tectonic processes ranging from continental drift to earthquake triggering. However, the spatial variation of these dynamic properties is poorly understood as they are difficult to measure. We exploited the large stress perturbation incurred by the 2016 earthquake sequence in Kumamoto, Japan, to directly image localized and distributed deformation. The earthquakes illuminated distinct regions of low effective viscosity in the lower crust, notably beneath the Mount Aso and Mount Kuju volcanoes, surrounded by larger-scale variations of viscosity across the back-arc. This study demonstrates a new potential for geodesy to directly probe rock rheology in situ across many spatial and temporal scales.

    更新日期:2017-04-14
  • [Report] High-performance light-emitting diodes based on carbene-metal-amides
    Science (IF 34.661) Pub Date : 2017-04-14
    Dawei Di, Alexander S. Romanov, Le Yang, Johannes M. Richter, Jasmine P. H. Rivett, Saul Jones, Tudor H. Thomas, Mojtaba Abdi Jalebi, Richard H. Friend, Mikko Linnolahti, Manfred Bochmann, Dan Credgington

    Organic light-emitting diodes (OLEDs) promise highly efficient lighting and display technologies. We introduce a new class of linear donor-bridge-acceptor light-emitting molecules, which enable solution-processed OLEDs with near-100% internal quantum efficiency at high brightness. Key to this performance is their rapid and efficient utilization of triplet states. Using time-resolved spectroscopy, we establish that luminescence via triplets occurs within 350 nanoseconds at ambient temperature, after reverse intersystem crossing to singlets. We find that molecular geometries exist at which the singlet-triplet energy gap (exchange energy) is close to zero, so that rapid interconversion is possible. Calculations indicate that exchange energy is tuned by relative rotation of the donor and acceptor moieties about the bridge. Unlike other systems with low exchange energy, substantial oscillator strength is sustained at the singlet-triplet degeneracy point.

    更新日期:2017-04-14
  • [Research Article] Cassini finds molecular hydrogen in the Enceladus plume: Evidence for hydrothermal processes
    Science (IF 34.661) Pub Date : 2017-04-14
    J. Hunter Waite, Christopher R. Glein, Rebecca S. Perryman, Ben D. Teolis, Brian A. Magee, Greg Miller, Jacob Grimes, Mark E. Perry, Kelly E. Miller, Alexis Bouquet, Jonathan I. Lunine, Tim Brockwell, Scott J. Bolton

    Saturn’s moon Enceladus has an ice-covered ocean; a plume of material erupts from cracks in the ice. The plume contains chemical signatures of water-rock interaction between the ocean and a rocky core. We used the Ion Neutral Mass Spectrometer onboard the Cassini spacecraft to detect molecular hydrogen in the plume. By using the instrument’s open-source mode, background processes of hydrogen production in the instrument were minimized and quantified, enabling the identification of a statistically significant signal of hydrogen native to Enceladus. We find that the most plausible source of this hydrogen is ongoing hydrothermal reactions of rock containing reduced minerals and organic materials. The relatively high hydrogen abundance in the plume signals thermodynamic disequilibrium that favors the formation of methane from CO2 in Enceladus’ ocean.

    更新日期:2017-04-14
  • [Editors' Choice] YAP is crucial for lung branching morphogenesis
    Science (IF 34.661) Pub Date : 2017-04-14
    Megan Eldred

    Author: Megan Eldred

    更新日期:2017-04-14
  • [Editors' Choice] Smashing ions to test a theory
    Science (IF 34.661) Pub Date : 2017-04-14
    Jelena Stajic

    Author: Jelena Stajic

    更新日期:2017-04-14
  • [Editors' Choice] Mixing up isotopes in evolved stars
    Science (IF 34.661) Pub Date : 2017-04-14
    Keith T. Smith

    Author: Keith T. Smith

    更新日期:2017-04-14
  • [Editors' Choice] Protectin and resolvin gut inflammation
    Science (IF 34.661) Pub Date : 2017-04-14
    Caroline Ash

    Author: Caroline Ash

    更新日期:2017-04-14
  • [Editors' Choice] TB exploits zombie cells
    Science (IF 34.661) Pub Date : 2017-04-14
    Stella M. Hurtley

    Author: Stella M. Hurtley

    更新日期:2017-04-14
  • [Editors' Choice] Near and far effects on gene expression
    Science (IF 34.661) Pub Date : 2017-04-14
    Laura M. Zahn

    Author: Laura M. Zahn

    更新日期:2017-04-14
  • [Editors' Choice] Heavy metals? No problem for this snail
    Science (IF 34.661) Pub Date : 2017-04-14
    Julia Fahrenkamp-Uppenbrink

    Author: Julia Fahrenkamp-Uppenbrink

    更新日期:2017-04-14
  • [This Week in Science] Regulatory T cells sans FoxP3
    Science (IF 34.661) Pub Date : 2017-04-14
    Anand Balasubramani

    Author: Anand Balasubramani

    更新日期:2017-04-14
  • [This Week in Science] Adding a twist for enhanced performance
    Science (IF 34.661) Pub Date : 2017-04-14
    Ian S. Osborne

    Author: Ian S. Osborne

    更新日期:2017-04-14
  • [This Week in Science] The evolving Ebola virus host response
    Science (IF 34.661) Pub Date : 2017-04-14
    Lindsey Pujanandez

    Author: Lindsey Pujanandez

    更新日期:2017-04-14
  • [This Week in Science] How the flagellum knows when to stop
    Science (IF 34.661) Pub Date : 2017-04-14
    Stella M. Hurtley

    Author: Stella M. Hurtley

    更新日期:2017-04-14
  • [This Week in Science] Coupling transcription and translation
    Science (IF 34.661) Pub Date : 2017-04-14
    Valda Vinson

    Author: Valda Vinson

    更新日期:2017-04-14
  • [This Week in Science] Making an unbiased library
    Science (IF 34.661) Pub Date : 2017-04-14
    Valda Vinson

    Author: Valda Vinson

    更新日期:2017-04-14
  • [This Week in Science] Refined understanding of the preprophase band
    Science (IF 34.661) Pub Date : 2017-04-14
    Pamela J. Hines

    Author: Pamela J. Hines

    更新日期:2017-04-14
  • [This Week in Science] Machines learn what people know implicitly
    Science (IF 34.661) Pub Date : 2017-04-14
    Gilbert Chin

    Author: Gilbert Chin

    更新日期:2017-04-14
  • [This Week in Science] Crustal rock strength from outer space
    Science (IF 34.661) Pub Date : 2017-04-14
    Brent Grocholski

    Author: Brent Grocholski

    更新日期:2017-04-14
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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