Emphysema diagnosis using X-ray dark-field imaging at a laser-driven compact synchrotron light source.

abstract：:A study of behavior and structure indicates that highly eusocial behavior arose twice in the bees--i.e., in the stingless bees (Meliponinae) and in the honeybees (Apinae). Morphological features demonstrate the distinctiveness of these two groups and the relationship of the latter to bumblebees (Bombini) and orchid be...

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

authors： Winston ML,Michener CD

更新日期：1977-03-01 00:00:00

abstract：:The three lipin phosphatidate phosphatase (PAP) enzymes catalyze a step in glycerolipid biosynthesis, the conversion of phosphatidate to diacylglycerol. Lipin-1 is critical for lipid synthesis and homeostasis in adipose tissue, liver, muscle, and peripheral nerves. Little is known about the physiological role of lipin...

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

authors： Dwyer JR,Donkor J,Zhang P,Csaki LS,Vergnes L,Lee JM,Dewald J,Brindley DN,Atti E,Tetradis S,Yoshinaga Y,De Jong PJ,Fong LG,Young SG,Reue K

更新日期：2012-09-11 00:00:00

abstract：:HIV-1, the cause of AIDS, is composed of four phylogenetic lineages, groups M, N, O, and P, each of which resulted from an independent cross-species transmission event of simian immunodeficiency viruses (SIVs) infecting African apes. Although groups M and N have been traced to geographically distinct chimpanzee commun...

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

authors： D'arc M,Ayouba A,Esteban A,Learn GH,Boué V,Liegeois F,Etienne L,Tagg N,Leendertz FH,Boesch C,Madinda NF,Robbins MM,Gray M,Cournil A,Ooms M,Letko M,Simon VA,Sharp PM,Hahn BH,Delaporte E,Mpoudi Ngole E,Peeters M

更新日期：2015-03-17 00:00:00

abstract：:In everyday life, a macroscopic valve is a device with a movable control element that regulates the flow of gases or liquids by blocking and opening passageways. Construction of such a device on the nanoscale level requires (i) suitably proportioned movable control elements, (ii) a method for operating them on demand,...

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

authors： Nguyen TD,Tseng HR,Celestre PC,Flood AH,Liu Y,Stoddart JF,Zink JI

更新日期：2005-07-19 00:00:00

abstract：:With continued debate over the functional significance of adult neurogenesis, identifying an in vivo correlate of neurogenesis has become an important goal. Here we rely on the coupling between neurogenesis and angiogenesis and test whether MRI measurements of cerebral blood volume (CBV) provide an imaging correlate o...

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

authors： Pereira AC,Huddleston DE,Brickman AM,Sosunov AA,Hen R,McKhann GM,Sloan R,Gage FH,Brown TR,Small SA

更新日期：2007-03-27 00:00:00

abstract：:Human immunodeficiency virus type 1 (HIV-1) viral DNA synthesis in quiescent and activated peripheral blood lymphocytes (PBLs) was studied. Incomplete viral DNA (previously demonstrated to be associated with HIV-1 virions) is carried by HIV-1 virions into quiescent and activated PBLs, contributing to the formation of ...

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

authors： Gao WY,Cara A,Gallo RC,Lori F

更新日期：1993-10-01 00:00:00

abstract：:This report describes the integration of laser-scanning fluorometric cytometry and nonseparation ligand-binding techniques to provide new assay methods adaptable to miniaturization and high-throughput screening. Receptor-bound, cyanine dye-labeled ligands, [Cy]ligands, were discriminated from those free in solution by...

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

authors： Zuck P,Lao Z,Skwish S,Glickman JF,Yang K,Burbaum J,Inglese J

更新日期：1999-09-28 00:00:00

abstract：:Laser-induced fluorescence at 337-nm excitation was used in vivo to differentiate neoplastic [cervical intraepithelial neoplasia (CIN)], nonneoplastic abnormal (inflammation and human papilloma viral infection), and normal cervical tissues. A colposcope (low-magnification microscope used to view the cervix with reflec...

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

authors： Ramanujam N,Mitchell MF,Mahadevan A,Warren S,Thomsen S,Silva E,Richards-Kortum R

更新日期：1994-10-11 00:00:00

abstract：:Mitotic recombination between homologous chromosomes is a genetic technique for mosaic analysis in model organisms. The general application of this technique in the mouse depends on establishment of effective recombination systems for individual chromosomes and reliable and sensitive methods for detection of recombina...

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

authors： Sun L,Wu X,Han M,Xu T,Zhuang Y

更新日期：2008-03-18 00:00:00

abstract：:Nutrition recommendations worldwide emphasize ingestion of plant-based diets rather than diets that rely primarily on animal products. However, this plant-based diet could limit the intake of essential nutrients such as calcium. Osteoporosis is one of the world's most prevalent nutritional disorders, and inadequate di...

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

authors： Morris J,Hawthorne KM,Hotze T,Abrams SA,Hirschi KD

更新日期：2008-02-05 00:00:00

abstract：:We analyzed the distribution of the cauliflower mosaic virus (CaMV) aphid transmission factor (ATF), produced via a baculovirus recombinant, within Sf9 insect cells. Immunogold labeling revealed that the ATF colocalizes with an atypical cytoskeletal network. Detailed observation by electron microscopy demonstrated tha...

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

authors： Blanc S,Schmidt I,Vantard M,Scholthof HB,Kuhl G,Esperandieu P,Cerutti M,Louis C

更新日期：1996-12-24 00:00:00

abstract：:Branched polyethylenimine (PEI) chains with an average molecular mass of 2 kDa (PEI2) have been covalently attached to gold nanoparticles (GNPs), and the potency of the resulting PEI2-GNPs conjugates as vectors for the delivery of plasmid DNA into monkey kidney (COS-7) cells in the presence of serum in vitro has been ...

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

authors： Thomas M,Klibanov AM

更新日期：2003-08-05 00:00:00

abstract：:The murine pre-B leukemic cell line 70Z/3 contains both an unrearranged immunoglobulin kappa-light-chain gene and a functionally rearranged but silent kappa-light-chain gene. Mitogenic stimulation of growing 70Z/3 cells with bacterial lipopolysaccharide (LPS) activates kappa-light-gene transcription and results in a 1...

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

authors： Wall R,Briskin M,Carter C,Govan H,Taylor A,Kincade P

更新日期：1986-01-01 00:00:00

abstract：:It is well known that two regular tetrahedra can be combined with a single regular octahedron to tile (complete fill) three-dimensional Euclidean space . This structure was called the "octet truss" by Buckminster Fuller. It was believed that such a tiling, which is the Delaunay tessellation of the face-centered cubic ...

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

authors： Conway JH,Jiao Y,Torquato S

更新日期：2011-07-05 00:00:00

abstract：:Polyketides represent an extremely diverse class of secondary metabolites often explored for their bioactive traits. These molecules are also attractive building blocks for chemical catalysis and polymerization. However, the use of polyketides in larger scale chemistry applications is stymied by limited titers and yie...

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

authors： Markham KA,Palmer CM,Chwatko M,Wagner JM,Murray C,Vazquez S,Swaminathan A,Chakravarty I,Lynd NA,Alper HS

更新日期：2018-02-27 00:00:00

abstract：:Lipid rafts are important signaling platforms in T cells. Little is known about their properties in human CD8(+) T cells. We studied polarization of lipid rafts by digital immunofluorescence microscopy in primary human T cells, using beads coated with anti-CD3 and anti-CD28 mAbs (CD3/28 beads). Unlike CD4(+) T cells, ...

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

authors： Kovacs B,Maus MV,Riley JL,Derimanov GS,Koretzky GA,June CH,Finkel TH

更新日期：2002-11-12 00:00:00

abstract：:The coexistence of two phylogenetically distinct symbiont species within a single cell, a condition not previously known in any metazoan, is demonstrated in the gills of a Mid-Atlantic Ridge hydrothermal vent mussel (family Mytilidae). Large and small symbiont morphotypes within the gill bacteriocytes are shown to be ...

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

authors： Distel DL,Lee HK,Cavanaugh CM

更新日期：1995-10-10 00:00:00

abstract：:Any isospectral family of two-dimensional Euclidean domains is shown to be compact in the C(infinity) topology. Previously Melrose, using heat invariants, was able to establish the C(infinity) compactness of the curvature of the boundary curves. The additional ingredient used in this paper to obtain the compactness of...

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

authors： Osgood B,Phillips R,Sarnak P

更新日期：1988-08-01 00:00:00

abstract：:Capsaicin is a unique alkaloid of the plant kingdom restricted to the genus Capsicum. Capsaicin is the pungency factor, a bioactive molecule of food and of medicinal importance. Capsaicin is useful as a counterirritant, antiarthritic, analgesic, antioxidant, and anticancer agent. Capsaicin biosynthesis involves conden...

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

authors： Prasad BC,Kumar V,Gururaj HB,Parimalan R,Giridhar P,Ravishankar GA

更新日期：2006-09-05 00:00:00

abstract：:Parathyroid cells have unusual responses to an increase in the external calcium concentration--a reduction in secretion and a depolarization. In an attempt to explain this behavior, we have studied voltage-clamped inside-out patches from bovine parathyroid cells. We found a potassium-selective channel that requires in...

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

authors： Jia M,Ehrenstein G,Iwasa K

更新日期：1988-10-01 00:00:00

abstract：:A mutation partially suppressing the UV sensitivity caused by recF143 in a uvrA6 background was located at codon 37 of recA where GTG (valine) became ATG (methionine). This mutation, originally named srf-803, was renamed recA803. Little if any suppression of the recF143 defect in UV induction of a lexA regulon promote...

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

authors： Madiraju MV,Templin A,Clark AJ

更新日期：1988-09-01 00:00:00

abstract：:Two operators, spatially separated from each other and from the promoters, repress the gal operon when bound to Gal repressor. Conversion of either gal operator to a lac operator results in derepression, although both Gal and Lac repressors are present, suggesting that mere occupation of operator sites is not sufficie...

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

authors： Haber R,Adhya S

更新日期：1988-12-01 00:00:00

abstract：:Conventional wisdom regarding mechanisms of bacterial pathogenesis holds that pathogens arise by external acquisition of distinct virulence factors, whereas determinants shared by pathogens and commensals are considered to be functionally equivalent and have been ignored as genes that could become adapted specifically...

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

authors： Sokurenko EV,Chesnokova V,Dykhuizen DE,Ofek I,Wu XR,Krogfelt KA,Struve C,Schembri MA,Hasty DL

更新日期：1998-07-21 00:00:00

abstract：:Natural killer (NK) cells mediate vital control of cancer and viral infection. They rely on MHC class I (MHC I)-specific self-receptors to identify and lyse diseased cells without harming self-MHC I-bearing host cells. NK cells bearing inhibitory self-receptors for host MHC I also undergo education, referred to as lic...

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

authors： Gamache A,Cronk JM,Nash WT,Puchalski P,Gillespie A,Wei H,Gray L,Hammarskjold ML,Xu W,Brown MG

更新日期：2019-12-16 00:00:00

abstract：:RNAs 1 and 2 of the tripartite cowpea chlorotic mottle virus (CCMV) genome are sufficient for RNA replication in protoplasts, whereas systemic infection of cowpea plants additionally requires RNA3, which encodes the 3a noncapsid protein and coat protein. By using biologically active CCMV cDNA clones, we find that dele...

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

authors： Allison R,Thompson C,Ahlquist P

更新日期：1990-03-01 00:00:00

abstract：:Type beta transforming growth factor (TGF-beta) activity was found in conditioned medium harvested from fetal rat and neonatal mouse calvariae by using the anchorage-independent growth of normal rat kidney fibroblasts as an indicator system. Calvariae incubated with parathyroid hormone, 1,25-dihydroxyvitamin D3, and i...

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

authors： Pfeilschifter J,Mundy GR

更新日期：1987-04-01 00:00:00

abstract：:The human beta-globin locus control region (LCR) consists of four erythroid-specific DNaseI hypersensitive sites (HSs) at the 5' end of the beta-globin cluster. The LCR functions over a long distance on chromosome 11 to regulate transcription and replication of the beta-globin genes. To determine whether the HSs funct...

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

authors： Bresnick EH,Tze L

更新日期：1997-04-29 00:00:00

abstract：:Protozoan parasites of the genus Leishmania undergo a complex life cycle involving transmission by biting sand flies and replication within mammalian macrophage phagolysosomes. A major component of the Leishmania surface coat is the glycosylphosphatidylinositol (GPI)-anchored polysaccharide called lipophosphoglycan (L...

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

authors： Späth GF,Epstein L,Leader B,Singer SM,Avila HA,Turco SJ,Beverley SM

更新日期：2000-08-01 00:00:00

abstract：:Like protein enzymes, RNA enzymes (ribozymes) provide specific binding sites for their substrates. We now show that equilibrium dissociation constants for complexes between the Tetrahymena ribozyme and its RNA substrates and products can be directly measured by electrophoresis in polyacrylamide gels containing divalen...

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

authors： Pyle AM,McSwiggen JA,Cech TR

更新日期：1990-11-01 00:00:00

abstract：:A density-shift method is described for analyzing insulin receptor synthesis and turnover in cultured cells labeled with "heavy" amino acids (2H, 13C, and 15N). Solubilized newly synthesized heavy and old "light" receptors are separated by isopycnic banding on CsCl gradients and then quantitated. Insulin receptor synt...

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

authors： Reed BC,Lane MD

更新日期：1980-01-01 00:00:00