Sadness, but not all negative emotions, heightens addictive substance use.

abstract：:We report a general method for screening, in solution, the impact of deviations from canonical Watson-Crick composition on the thermodynamic stability of nucleic acid duplexes. We demonstrate how fluorescence resonance energy transfer (FRET) can be used to detect directly free energy differences between an initially f...

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

authors： Gelfand CA,Plum GE,Mielewczyk S,Remeta DP,Breslauer KJ

更新日期：1999-05-25 00:00:00

abstract：:Little is known about stem cell biology or the specialized environments or niches believed to control stem cell renewal and differentiation in self-renewing tissues of the body. Functional assays for stem cells are available only for hematopoiesis and spermatogenesis, and the microenvironment, or niche, for hematopoie...

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

authors： Shinohara T,Orwig KE,Avarbock MR,Brinster RL

更新日期：2001-05-22 00:00:00

abstract：:The enzymes responsible for the oxidation of n-octane to octanoic acid or beyond in Pseudomonas oleovorans are octane inducible and are coded by genes borne on a transmissible extrachromosomal element. The octane to octanoate enzymes induced by octane are repressed by octanol. The chromosome also carries genes coding ...

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

authors： Chakrabarty AM,Chou G,Gunsalus IC

更新日期：1973-04-01 00:00:00

abstract：:Global patterns of biodiversity reflect both regional and local processes, but the relative importance of local ecological limits to species coexistence, as influenced by the physical environment, in contrast to regional processes including species production, dispersal, and extinction, is poorly understood. Failure t...

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

authors： Ricklefs RE,He F

更新日期：2016-01-19 00:00:00

abstract：:Sympatric speciation (SS), i.e., speciation within a freely breeding population or in contiguous populations, was first proposed by Darwin [Darwin C (1859) On the Origins of Species by Means of Natural Selection] and is still controversial despite theoretical support [Gavrilets S (2004) Fitness Landscapes and the Orig...

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

authors： Li K,Hong W,Jiao H,Wang GD,Rodriguez KA,Buffenstein R,Zhao Y,Nevo E,Zhao H

更新日期：2015-09-22 00:00:00

abstract：:The trinucleotide CCA sequence is present at the 3' terminus of all mature tRNAs. Despite this high degree of conservation, we have been able to prepare in vitro transcripts of Escherichia coli tRNA(Val) with altered 3' termini that are readily aminoacylated and can function in polypeptide synthesis. Replacement of th...

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

authors： Liu M,Horowitz J

更新日期：1994-10-25 00:00:00

abstract：:Gene transfer into early embryos is a powerful methodology for unraveling the molecular bases of developmental processes. One can attempt to minimize widespread effects of an exogenous gene by using tissue- or region-specific promoters in the few instances where they are available. We have developed a method that bypa...

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

authors： Fekete DM,Cepko CL

更新日期：1993-03-15 00:00:00

abstract：:Normal vision requires the precise control of vascular growth to maintain corneal transparency. Here we provide evidence for a unique mechanism by which the Forkhead box transcription factor FoxC1 regulates corneal vascular development. Murine Foxc1 is essential for development of the ocular anterior segment, and in h...

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

authors： Seo S,Singh HP,Lacal PM,Sasman A,Fatima A,Liu T,Schultz KM,Losordo DW,Lehmann OJ,Kume T

更新日期：2012-02-07 00:00:00

abstract：:Based on structural information derived from the F NMR data of labeled rhodopsins, rhodopsin crystal structure, and excited-state properties of model polyenes, we propose a molecular mechanism that accounts specifically for the causes of the well-known enhanced photoreactivity of rhodopsin (increased rates and quantum...

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

authors： Liu RS,Colmenares LU

更新日期：2003-12-09 00:00:00

abstract：:Although sunlight provides the energy necessary for plants to survive and grow, light can also damage reaction centers of photosystem II (PSII) and reduce photochemical efficiency. To prevent damage, plants possess photoprotective mechanisms that dissipate excess excitation. A subset of these mechanisms is collectivel...

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

authors： Leonelli L,Brooks MD,Niyogi KK

更新日期：2017-08-15 00:00:00

abstract：:DNA triple helices offer new perspectives toward oligonucleotide-directed gene regulation. However, the poor stability of some of these structures might limit their use under physiological conditions. Specific ligands can intercalate into DNA triple helices and stabilize them. Molecular modeling and thermal denaturati...

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

authors： Escudé C,Nguyen CH,Kukreti S,Janin Y,Sun JS,Bisagni E,Garestier T,Hélène C

更新日期：1998-03-31 00:00:00

abstract：:Overexpression of the Gossypium hirsutum sucrose synthase (SuSy) gene under the control of 2 promoters was examined in hybrid poplar (Populus alba x grandidentata). Analysis of RNA transcript abundance, enzyme activity, cell wall composition, and soluble carbohydrates revealed significant changes in the transgenic lin...

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

authors： Coleman HD,Yan J,Mansfield SD

更新日期：2009-08-04 00:00:00

abstract：:From endonuclease EcoRI partial libraries of DNAs from mouse embryo and MOPC 141, a gamma 2b-producing myeloma, clones were isolated by using a DNA fragment carrying the gamma 2b constant (C) region gene as a hybridization probe. One clone from MOPC 141 contained a heavy chain variable (V) gene and the C gamma 2b gene...

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

authors： Maki R,Traunecker A,Sakano H,Roeder W,Tonegawa S

更新日期：1980-04-01 00:00:00

abstract：:The day we understand the time evolution of subcellular events at a level of detail comparable to physical systems governed by Newton's laws of motion seems far away. Even so, quantitative approaches to cellular dynamics add to our understanding of cell biology. With data-guided frameworks we can develop better predic...

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

authors： Ronquist S,Patterson G,Muir LA,Lindsly S,Chen H,Brown M,Wicha MS,Bloch A,Brockett R,Rajapakse I

更新日期：2017-11-07 00:00:00

abstract：:Combinations of low dosages of purified murine hematopoietic colony-stimulating factors (CSFs)--L-cell CSF type 1 (CSF-1), recombinant interleukin 3 (IL-3), and recombinant granulocyte/macrophage CSF (GM-CSF)--were compared with single CSFs for their influence on the cycling rates and numbers of bone marrow granulocyt...

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

authors： Broxmeyer HE,Williams DE,Hangoc G,Cooper S,Gillis S,Shadduck RK,Bicknell DC

更新日期：1987-06-01 00:00:00

abstract：:Progress toward understanding the biology of prostate cancer has been slow due to the few animal research models available to study the spectrum of this uniquely human disease. To develop an animal model for prostate cancer, several lines of transgenic mice were generated by using the prostate-specific rat probasin pr...

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

authors： Greenberg NM,DeMayo F,Finegold MJ,Medina D,Tilley WD,Aspinall JO,Cunha GR,Donjacour AA,Matusik RJ,Rosen JM

更新日期：1995-04-11 00:00:00

abstract：:Plants require metals for essential functions ranging from respiration to photosynthesis. These metals also contribute to the nutritional value of plants for both humans and livestock. Additionally, plants have the ability to accumulate nonessential metals such as cadmium and lead, and this ability could be harnessed ...

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

authors： Rogers EE,Eide DJ,Guerinot ML

更新日期：2000-10-24 00:00:00

abstract：:The Lyz endolysin of bacteriophage P1 was found to cause lysis of the host without a holin. Induction of a plasmid-cloned lyz resulted in lysis, and the lytic event could be triggered prematurely by treatments that dissipate the proton-motive force. Instead of requiring a holin, export was mediated by an N-terminal tr...

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

authors： Xu M,Struck DK,Deaton J,Wang IN,Young R

更新日期：2004-04-27 00:00:00

abstract：:The ability to respond selectively to particular frequency components of sensory inputs is fundamental to signal processing in the ear. The frog (Rana pipiens) sacculus, which is used for social communication and escape behaviors, is an exquisitely sensitive detector of sounds and ground-borne vibrations in the 5- to ...

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

authors： Rutherford MA,Roberts WM

更新日期：2006-02-21 00:00:00

abstract：:Fertilization and certain later stages in mammalian embryonic development require fusion between membranes of individual cells. The mechanism of eukaryotic cell-cell fusion is unknown, and no surface molecules required for this process have been unequivocally identified. The role of the sperm surface protein fertilin ...

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

authors： Myles DG,Kimmel LH,Blobel CP,White JM,Primakoff P

更新日期：1994-05-10 00:00:00

abstract：:In the presence of phenylalanine, GTP cyclohydrolase I feedback regulatory protein (GFRP) forms a stimulatory 360-kDa complex with GTP cyclohydrolase I (GTPCHI), which is the rate-limiting enzyme in the biosynthesis of tetrahydrobiopterin. The crystal structure of the stimulatory complex reveals that the GTPCHI decame...

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

authors： Maita N,Okada K,Hatakeyama K,Hakoshima T

更新日期：2002-02-05 00:00:00

abstract：:Long interspersed nuclear elements 1 (L1) are active retrotransposons that reside in many species, including humans and rodents. L1 elements produce an RNA intermediate that is reverse transcribed to DNA and inserted in a new genomic location. We have tagged an active human L1 element (L1(RP)) with a gene encoding enh...

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

authors： Prak ET,Dodson AW,Farkash EA,Kazazian HH Jr

更新日期：2003-02-18 00:00:00

abstract：:The recent characterization of the prokaryotic Cys(2)His(2) zinc-finger domain, identified in Ros protein from Agrobacterium tumefaciens, has demonstrated that, although possessing a similar zinc coordination sphere, this domain is structurally very different from its eukaryotic counterpart. A search in the databases ...

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

authors： Baglivo I,Russo L,Esposito S,Malgieri G,Renda M,Salluzzo A,Di Blasio B,Isernia C,Fattorusso R,Pedone PV

更新日期：2009-04-28 00:00:00

abstract：:Dihydropteridine reductase (EC 1.6.99.7) is a member of the recently identified family of proteins known as short-chain dehydrogenases. When the x-ray structure of dihydropteridine reductase is correlated with conserved amino acid sequences characteristic of this enzyme class, two important common structural regions c...

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

authors： Varughese KI,Xuong NH,Kiefer PM,Matthews DA,Whiteley JM

更新日期：1994-06-07 00:00:00

abstract：:We show that the motion of a slightly compressible fluid is near that of an incompressible fluid. That is, for a given initial velocity field, the motion of a compressible fluid with large sound speed is near to that of an idealized incompressible fluid. We consider the compressible fluid motion in Lagrangian coordina...

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

authors： Ebin DG

更新日期：1975-02-01 00:00:00

abstract：:Toward understanding their redundancies and interactions in hemostasis and thrombosis, we examined the roles of thrombin receptors (protease-activated receptors, PARs) and the ADP receptor P2RY12 (purinergic receptor P2Y G protein-coupled 12) in human and mouse platelets ex vivo and in mouse models. Par3(-/-) and Par4...

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

authors： Cornelissen I,Palmer D,David T,Wilsbacher L,Concengco C,Conley P,Pandey A,Coughlin SR

更新日期：2010-10-26 00:00:00

abstract：:Despite their relative simplicity, bacteria have complex anatomy at the subcellular level. At the cell poles of Caulobacter crescentus, a 177-amino acid (aa) protein called PopZ self-assembles into 3D polymeric superstructures. Remarkably, we find that this assemblage interacts directly with at least eight different p...

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

authors： Holmes JA,Follett SE,Wang H,Meadows CP,Varga K,Bowman GR

更新日期：2016-11-01 00:00:00

abstract：:Metastasis of solid tumors is a key determinant of cancer patient survival. Targeting micrometastases using nanoparticles could offer a way to stop metastatic tumor growth before it causes excessive patient morbidity. However, nanoparticle delivery to micrometastases is difficult to investigate because micrometastases...

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

authors： Kingston BR,Syed AM,Ngai J,Sindhwani S,Chan WCW

更新日期：2019-07-23 00:00:00

abstract：:How colloidal particles interact with each other is one of the key issues that determines our ability to interpret experimental results for phase transitions in colloidal dispersions and our ability to apply colloid science to various industrial processes. The long-accepted theories for answering this question have be...

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

authors： Wu J,Bratko D,Prausnitz JM

更新日期：1998-12-22 00:00:00

abstract：:The receptor for granulocyte-macrophage colony-stimulating factor (GM-CSF) is composed of an alpha and beta subunit, which together form the high-affinity receptor. The alpha subunit by itself binds ligand at low affinity, whereas the isolated beta subunit does not bind GM-CSF. It is generally believed that the high-a...

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

authors： Ding DX,Rivas CI,Heaney ML,Raines MA,Vera JC,Golde DW

更新日期：1994-03-29 00:00:00