Geometric cues for directing the differentiation of mesenchymal stem cells.

abstract：:Genetic manipulation of nitrogenase and key glutamate-forming enzymes can provide mutants that excrete fixed N2 as NH4+. A derepressed N2 fxation mutant (SK-24) has been isolated , which excretes up to 20.2 mumol of fixed N2 as NH4+ per mg of cell protein in 24 hr at room temperature. Biochemical analysis shows that t...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Shanmugam KT,Valentine RC

更新日期：1975-01-01 00:00:00

abstract：:Studies of biotic remains of polar ice caps have been limited to morphological identification of plant pollen and spores. By using sensitive molecular techniques, we now demonstrate a much greater range of detectable organisms; from 2000- and 4000-year-old ice-core samples, we obtained and characterized 120 clones tha...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Willerslev E,Hansen AJ,Christensen B,Steffensen JP,Arctander P

更新日期：1999-07-06 00:00:00

abstract：:Throughout time, operational laws and concepts from complex systems have been employed to quantitatively model important aspects and interactions in nature and society. Nevertheless, it remains enigmatic and challenging, yet inspiring, to predict the actual interdependencies that comprise the structure of such systems...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Stavroglou SK,Pantelous AA,Stanley HE,Zuev KM

更新日期：2020-04-07 00:00:00

abstract：:The nuclear factor-κB (NFκB) family of transcription factors has been implicated in inflammatory disorders, viral infections, and cancer. Most of the drugs that inhibit NFκB show significant side effects, possibly due to sustained NFκB suppression. Drugs affecting induced, but not basal, NFκB activity may have the pot...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Chen M,Liang J,Ji H,Yang Z,Altilia S,Hu B,Schronce A,McDermott MSJ,Schools GP,Lim CU,Oliver D,Shtutman MS,Lu T,Stark GR,Porter DC,Broude EV,Roninson IB

更新日期：2017-09-19 00:00:00

abstract：:Platelet factor 4 is shown to be a chemotactic protein for human polymorphonuclear leukocytes and monocytes at concentrations found in human serum and reached locally in injured tissue. The maximum chemotactic response to platelet factor 4 nearly equals that achieved with saturating concentrations of the chemotactic a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Deuel TF,Senior RM,Chang D,Griffin GL,Heinrikson RL,Kaiser ET

更新日期：1981-07-01 00:00:00

abstract：:A series of recombinant plasmids was generated in Escherichia coli in which the TEM beta-lactamase translocon (TnA) was inserted into the small plasmid RSF1010. RSF1010 is a 5.5 X 10(6) dalton nonconjugative plasmid which confers resistance to streptomycin and sulfonamide. The recombinant plasmids can be classified in...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Heffron F,Rubens C,Falkow S

更新日期：1975-09-01 00:00:00

abstract：:RNA is involved in a variety of chromatin modification events, ranging from large-scale structural rearrangements to subtle local affects. Here, we extend the evidence for RNA-chromatin interactions to the centromere core. The data indicate that maize centromeric retrotransposons (CRMs) and satellite repeats (CentC) a...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Topp CN,Zhong CX,Dawe RK

更新日期：2004-11-09 00:00:00

abstract：:The versatility of CRISPR-Cas endonucleases as a tool for biomedical research has led to diverse applications in gene editing, programmable transcriptional control, and nucleic acid detection. Most CRISPR-Cas systems, however, suffer from off-target effects and unpredictable nonspecific binding that negatively impact ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Specht DA,Xu Y,Lambert G

更新日期：2020-05-26 00:00:00

abstract：:Previous reconstructions of marine fishing fleets have aggregated data without regard to the artisanal and industrial sectors. Engine power has often been estimated from subsets of the developed world, leading to inflated results. We disaggregated data into three sectors, artisanal (unpowered/powered) and industrial, ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rousseau Y,Watson RA,Blanchard JL,Fulton EA

更新日期：2019-06-18 00:00:00

abstract：:Regulation of biological phenomena occurs in all types of systems, being manifested in many different reaction types, from allosteric behavior in proteins, through modulation in energy and information transfer, to the control of growth and differentiation in cells, organelles, and organisms. In this communication, a m...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Sligar SG,Gunsalus IC

更新日期：1976-04-01 00:00:00

abstract：:OLE (ornate, large, extremophilic) RNAs comprise a class of structured noncoding RNAs (ncRNAs) found in many extremophilic bacteria species. OLE RNAs constitute one of the longest and most widespread bacterial ncRNA classes whose major biochemical function remains unknown. In the Gram-positive alkaliphile Bacillus hal...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Harris KA,Zhou Z,Peters ML,Wilkins SG,Breaker RR

更新日期：2018-07-03 00:00:00

abstract：:Examination of old human lenses indicates that low-molecular-weight alpha crystallin is not present in the inner 30-40%, the nucleus, of the lens. The remainder of such lenses, the periphery, contains normal levels of this protein. This finding is in marked contrast to observations in young lenses, where a large quant...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Roy D,Spector A

更新日期：1976-10-01 00:00:00

abstract：:The three-dimensional structures of RNA enzymes form catalytic centers that include specific substrate binding sites. High-resolution determination of these and other RNA structures is essential for a detailed understanding of the function of RNA in biological systems. The crystal structures of only a few RNA molecule...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Doudna JA,Grosshans C,Gooding A,Kundrot CE

更新日期：1993-08-15 00:00:00

abstract：:We used a family-based cluster detection approach designed to localize significant rare disease-risk variants clusters within a region of interest to systematically search for schizophrenia (SCZ) susceptibility genes within 49 genomic loci previously implicated by de novo copy number variants. Using two independent wh...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Ionita-Laza I,Xu B,Makarov V,Buxbaum JD,Roos JL,Gogos JA,Karayiorgou M

更新日期：2014-01-07 00:00:00

abstract：:Previous work on perceptual decision making in the sensorimotor system has shown population dynamics in the beta band, corresponding to the encoding of stimulus properties and the final decision outcome. Here, we asked how oscillatory dynamics in the medial premotor cortex (MPC) contribute to supramodal perceptual dec...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Haegens S,Vergara J,Rossi-Pool R,Lemus L,Romo R

更新日期：2017-12-26 00:00:00

abstract：:Quantitative studies of protein abundance rarely span more than a small number of experimental conditions and replicates. In contrast, quantitative studies of transcript abundance often span hundreds of experimental conditions and replicates. This situation exists, in part, because extracting quantitative data from la...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Khan Z,Bloom JS,Garcia BA,Singh M,Kruglyak L

更新日期：2009-09-15 00:00:00

abstract：:Oxidative stress induced in live HeLa cells by menadione (2-methyl-1,4-napthaquinone) was studied in real time by scanning electrochemical microscopy (SECM). The hydrophobic molecule menadione diffuses through a living cell membrane where it is toxic to the cell. However, in the cell it is conjugated with glutathione ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Koley D,Bard AJ

更新日期：2012-07-17 00:00:00

abstract：:Lineage plasticity is a prominent feature of pancreatic ductal adenocarcinoma (PDA) cells, which can occur via deregulation of lineage-specifying transcription factors. Here, we show that the zinc finger protein ZBED2 is aberrantly expressed in PDA and alters tumor cell identity in this disease. Unexpectedly, our epig...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Somerville TDD,Xu Y,Wu XS,Maia-Silva D,Hur SK,de Almeida LMN,Preall JB,Koo PK,Vakoc CR

更新日期：2020-05-26 00:00:00

abstract：:Human herpesvirus 6 (HHV-6) like other herpesviruses, expresses sequentially immediate early (IE), early, and late genes during lytic infection. Evidence of ability to establish latent infection has not been available, but by analogy with other herpesviruses it could be expected that IE genes that regulate and transac...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Rotola A,Ravaioli T,Gonelli A,Dewhurst S,Cassai E,Di Luca D

更新日期：1998-11-10 00:00:00

abstract：:The chemotherapeutic drug Taxol is known to interact within a specific site on beta-tubulin. Although the general location of the site has been defined by photoaffinity labeling and electron crystallography, the original data were insufficient to make an absolute determination of the bound conformation. We have now co...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Snyder JP,Nettles JH,Cornett B,Downing KH,Nogales E

更新日期：2001-04-24 00:00:00

abstract：:The first step in poliovirus replication is binding of virus to a cellular receptor. Mouse L cells, which are resistant to poliovirus infection because they do not bear a poliovirus receptor, were transformed with HeLa cell (human) DNA to poliovirus sensitivity at a frequency of approximately 1 in 50,000 transformants...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Mendelsohn C,Johnson B,Lionetti KA,Nobis P,Wimmer E,Racaniello VR

更新日期：1986-10-01 00:00:00

abstract：:Seemingly similar individuals often experience drastically different success trajectories, with some repeatedly failing and others consistently succeeding. One explanation is preexisting variability along unobserved fitness dimensions that is revealed gradually through differential achievement. Alternatively, positive...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： van de Rijt A,Kang SM,Restivo M,Patil A

更新日期：2014-05-13 00:00:00

abstract：:The ability of materials to define the architecture and microenvironment experienced by cells provides new opportunities to direct the fate of human pluripotent stem cells (HPSCs) [Robinton DA, Daley GQ (2012) Nature 481(7381):295-305]. However, the conditions required for self-renewal vs. differentiation of HPSCs are...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Dixon JE,Shah DA,Rogers C,Hall S,Weston N,Parmenter CD,McNally D,Denning C,Shakesheff KM

更新日期：2014-04-15 00:00:00

abstract：:Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary ge...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Arnold BJ,Lahner B,DaCosta JM,Weisman CM,Hollister JD,Salt DE,Bomblies K,Yant L

更新日期：2016-07-19 00:00:00

abstract：:The paradigmatic example of a continuous quantum phase transition is the transverse field Ising ferromagnet. In contrast to classical critical systems, whose properties depend only on symmetry and the dimension of space, the nature of a quantum phase transition also depends on the dynamics. In the transverse field Isi...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Maharaj AV,Rosenberg EW,Hristov AT,Berg E,Fernandes RM,Fisher IR,Kivelson SA

更新日期：2017-12-19 00:00:00

abstract：:Several dual route models of human speech processing have been proposed suggesting a large-scale anatomical division between cortical regions that support motor-phonological aspects vs. lexical-semantic aspects of speech processing. However, to date, there is no complete agreement on what areas subserve each route or ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fridriksson J,Yourganov G,Bonilha L,Basilakos A,Den Ouden DB,Rorden C

更新日期：2016-12-27 00:00:00

abstract：:Leukocytes normally marginate toward the vascular wall in large vessels and within the microvasculature. Reversal of this process, leukocyte demargination, leads to substantial increases in the clinical white blood cell and granulocyte count and is a well-documented effect of glucocorticoid and catecholamine hormones,...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Fay ME,Myers DR,Kumar A,Turbyfield CT,Byler R,Crawford K,Mannino RG,Laohapant A,Tyburski EA,Sakurai Y,Rosenbluth MJ,Switz NA,Sulchek TA,Graham MD,Lam WA

更新日期：2016-02-23 00:00:00

abstract：:Very-long-baseline interferometry images of the nuclear region of the radio galaxy Cygnus A reveal a pronounced "core" and a knotty jet and counterjet. The knots are moving away from the core at apparent speeds which are subluminal for h = 1 [h = H0/100 km.s-1.Mpc-1;1 parsec (pc) = 3.09 x 10(16)m] and about c for h = ...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Bartel N,Sorathia B,Bietenholz MF,Carilli CL,Diamond P

更新日期：1995-12-05 00:00:00

abstract：:Navigation, the ability to reach desired goal locations, is critical for animals and humans. Animal navigation has been studied extensively in birds, insects, and some marine vertebrates and invertebrates, yet we are still far from elucidating the underlying mechanisms in other taxonomic groups, especially mammals. He...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Tsoar A,Nathan R,Bartan Y,Vyssotski A,Dell'Omo G,Ulanovsky N

更新日期：2011-09-13 00:00:00

abstract：:Huntington disease stems from a mutation of the protein huntingtin and is characterized by selective loss of discrete neuronal populations in the brain. Despite a massive loss of neurons in the corpus striatum, NO-generating neurons are intact. We recently identified a brain-specific protein that associates with hunti...

journal_title：Proceedings of the National Academy of Sciences of the United States of America

authors： Li XJ,Sharp AH,Li SH,Dawson TM,Snyder SH,Ross CA

更新日期：1996-05-14 00:00:00