Elevated serum ribonuclease in patients with pancreatic cancer.

abstract：:The internal dynamics of bacteriorhodopsin, the light-driven proton pump in the purple membrane of Halobacterium halobium, has been studied by inelastic neutron scattering for various conditions of temperature and hydration. Light activation can take place when the membrane is vibrating harmonically. The ability of th...

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

authors： Ferrand M,Dianoux AJ,Petry W,Zaccaï G

更新日期：1993-10-15 00:00:00

abstract：:A combined genetic, biochemical, and immunological approach has clarified structural relationships involving the first three enzymes of de novo pyrimidine biosynthesis. A procedure involving antibody and protein A-Sepharose was used to isolate the enzymes carbamoyl-phosphate synthase [ATP:carbamate phosphotransferase ...

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

authors： Davidson JN,Patterson D

更新日期：1979-04-01 00:00:00

abstract：:A mutant strain deficient in RNase T was isolated and used to study the role of this enzyme in Escherichia coli. Strains lacking as much as 70% of RNase T activity, alone or in combination with the absence of other RNases, display normal growth properties. However, in cca strains, which lack tRNA nucleotidyltransferas...

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

authors： Deutscher MP,Marlor CW,Zaniewski R

更新日期：1985-10-01 00:00:00

abstract：:We suggested to 228 subjects in two experiments that, as children, they had had negative experiences with a fattening food. An additional 107 subjects received no such suggestion and served as controls. In Experiment 1, a minority of subjects came to believe that they had felt ill after eating strawberry ice cream as ...

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

authors： Bernstein DM,Laney C,Morris EK,Loftus EF

更新日期：2005-09-27 00:00:00

abstract：:We investigate the hypothesis that two classes of Ca2+ currents, one quickly inactivated by Ca2+ and one slowly inactivated by voltage, contribute to bursting electrical activity in pancreatic islets. A mathematical model of these currents is fit to the experimental whole-cell current-voltage and inactivation profiles...

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

authors： Keizer J,Smolen P

更新日期：1991-05-01 00:00:00

abstract：:Three distinct endosomal fractions were isolated in high purity from livers of estradiol-treated rats. Each fraction had characteristic physical and ultrastructural properties, but the lipid composition and major proteins of their membranes were similar and differed from those derived from the Golgi apparatus. Injecte...

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

authors： Belcher JD,Hamilton RL,Brady SE,Hornick CA,Jaeckle S,Schneider WJ,Havel RJ

更新日期：1987-10-01 00:00:00

abstract：:A graph-theoretic condition is given for the existence of stable solutions to the Volterra-Lotka equations. ...

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

authors： Yorke JA,Anderson WN

更新日期：1973-07-01 00:00:00

abstract：:Protocell models are used to investigate how cells might have first assembled on Earth. Some, like oil-in-water droplets, can be seemingly simple models, while able to exhibit complex and unpredictable behaviors. How such simple oil-in-water systems can come together to yield complex and life-like behaviors remains a ...

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

authors： Points LJ,Taylor JW,Grizou J,Donkers K,Cronin L

更新日期：2018-01-30 00:00:00

abstract：:IscR (iron-sulfur cluster regulator) is encoded by an ORF located immediately upstream of genes coding for the Escherichia coli Fe-S cluster assembly proteins, IscS, IscU, and IscA. IscR shares amino acid similarity with MarA, a member of the MarA/SoxS/Rob family of transcription factors. In this study, we found that ...

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

authors： Schwartz CJ,Giel JL,Patschkowski T,Luther C,Ruzicka FJ,Beinert H,Kiley PJ

更新日期：2001-12-18 00:00:00

abstract：:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, employs two key host proteins to gain entry and replicate within cells, angiotensin-converting enzyme 2 (ACE2) and the cell surface transmembrane protease serine 2 (TMPRSS2). TMPRSS2 was first characterized as an androgen...

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

authors： Qiao Y,Wang XM,Mannan R,Pitchiaya S,Zhang Y,Wotring JW,Xiao L,Robinson DR,Wu YM,Tien JC,Cao X,Simko SA,Apel IJ,Bawa P,Kregel S,Narayanan SP,Raskind G,Ellison SJ,Parolia A,Zelenka-Wang S,McMurry L,Su F,Wang R,

更新日期：2020-12-11 00:00:00

abstract：:This introduction to the Special Feature presents the context for science during the Deepwater Horizon oil spill response, summarizes how scientific knowledge was integrated across disciplines and statutory responsibilities, identifies areas where scientific information was accurate and where it was not, and considers...

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

authors： Lubchenco J,McNutt MK,Dreyfus G,Murawski SA,Kennedy DM,Anastas PT,Chu S,Hunter T

更新日期：2012-12-11 00:00:00

abstract：:The mammalian anx7 gene codes for a Ca(2+)-activated GTPase, which supports Ca(2+)/GTP-dependent secretion events and Ca(2+) channel activities in vitro and in vivo. To test whether anx7 might be involved in Ca(2+) signaling in secreting pancreatic beta cells, we knocked out the anx7 gene in the mouse and tested the i...

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

authors： Srivastava M,Atwater I,Glasman M,Leighton X,Goping G,Caohuy H,Miller G,Pichel J,Westphal H,Mears D,Rojas E,Pollard HB

更新日期：1999-11-23 00:00:00

abstract：:Eleocharis vivipara Link, a freshwater amphibious leafless plant belonging to the Cyperaceae can grow in both terrestrial and submersed aquatic conditions. Two forms of E. vivipara obtained from these contrasting environments were examined for the characteristics associated with C(4) and C(3) photosynthesis. In the te...

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

authors： Ueno O,Samejima M,Muto S,Miyachi S

更新日期：1988-09-01 00:00:00

abstract：:Mouse L929 cells were incubated with antibody-targeted liposomes containing oligodeoxyribonucleotides (oligomers). When the oligomer was a 15-mer complementary to the 5'-end region of the mRNA encoding the N protein of vesicular stomatitis virus, the cells became less permissive for multiplication of that virus; great...

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

authors： Leonetti JP,Machy P,Degols G,Lebleu B,Leserman L

更新日期：1990-04-01 00:00:00

abstract：:The T helper type 2 (Th2) cytokine genes Il4, Il5, and Il13 are contained within a 140-kb region of mouse chromosome 11 and their expression is controlled by a locus control region (LCR) embedded within this locus. The LCR is composed of a number of DNase I-hypersensitive sites (HSs), which are believed to encompass t...

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

authors： Williams A,Lee GR,Spilianakis CG,Hwang SS,Eisenbarth SC,Flavell RA

更新日期：2013-04-23 00:00:00

abstract：:In North America there are two generally recognized pathotypes (pathotypes 1 and 2) of the fungus Entomophaga grylli which show host-preferential infection of grasshopper subfamilies. Pathotype 3, discovered in Australia, has a broader grasshopper host range and was considered to be a good biocontrol agent. Between 19...

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

authors： Bidochka MJ,Walsh SR,Ramos ME,St Leger RJ,Silver JC,Roberts DW

更新日期：1996-01-23 00:00:00

abstract：:Estradiol-17beta administration to young (10- to 12-week-old) rabbits to produce the "estrogen-dominated" uterus increased the uterine contractile response to both oxytocin and methacholine in vitro. In "progesterone-dominated" uteri, obtained from rabbits that received progesterone for 4 days after estrogen pretreatm...

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

authors： Nissenson R,Fluoret G,Hechter O

更新日期：1978-04-01 00:00:00

abstract：:To study the behavior of hematopoietic stem cells in vivo, we transplanted glucose-6-phosphate dehydrogenase (G6PD) heterozygous (female Safari) cats with small amounts of autologous marrow. The G6PD phenotypes of erythroid burst-forming units and granulocyte/macrophage colony-forming units were repeatedly assayed for...

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

authors： Abkowitz JL,Persik MT,Shelton GH,Ott RL,Kiklevich JV,Catlin SN,Guttorp P

更新日期：1995-03-14 00:00:00

abstract：:The Escherichia coli galactokinase gene (galK) was inserted into a modified early region transcription unit of simian virus 40 (SV40) contained on a bacterial plasmid. Introduction of this pSVK vector into monkey, mouse, and hamster cell lines by transfection resulted in efficient expression of the bacterial galK gene...

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

authors： Schümperli D,Howard BH,Rosenberg M

更新日期：1982-01-01 00:00:00

abstract：:A 43-kDa peripheral membrane protein is known to copurify with acetylcholine receptor (AcChoR)-rich membranes isolated from the electric organ of Torpedo californica. Immunoelectron microscopy and crosslinking studies have demonstrated that this 43-kDa protein is closely associated with the cytoplasmic domain(s) of th...

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

authors： Burden SJ

更新日期：1985-12-01 00:00:00

abstract：:The x-ray sensitive hamster cell line xrs-6 is deficient in DNA double-strand break (DSB) repair and exhibits impaired V(D)J recombination. The molecular defect in this line is in the 80-kDa subunit of the Ku autoantigen, a protein that binds to DNA ends and recruits the DNA-dependent protein kinase to DNA. Using an I...

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

authors： Liang F,Romanienko PJ,Weaver DT,Jeggo PA,Jasin M

更新日期：1996-08-20 00:00:00

abstract：:We present a model describing how Mg(2+) binds and stabilizes specific RNA structures. In this model, RNA stabilization arises from two energetically distinct modes of Mg(2+) binding: diffuse- and site-binding. Diffusely bound Mg(2+) are electrostatically attracted to the strong anionic field around the RNA and are ac...

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

authors： Misra VK,Draper DE

更新日期：2001-10-23 00:00:00

abstract：:It is becoming clear that steroids can be synthesized de novo by the brain and other nervous systems. Such steroids are called neurosteroids, and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. In this study, we show that the newt brain actively produces 7alpha-hydroxypregne...

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

authors： Matsunaga M,Ukena K,Baulieu EE,Tsutsui K

更新日期：2004-12-07 00:00:00

abstract：:Leptin is a pivotal regulator of energy and glucose homeostasis, and defects in leptin signaling result in obesity and diabetes. The ATP-sensitive potassium (K(ATP)) channels couple glucose metabolism to insulin secretion in pancreatic β-cells. In this study, we provide evidence that leptin modulates pancreatic β-cell...

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

authors： Park SH,Ryu SY,Yu WJ,Han YE,Ji YS,Oh K,Sohn JW,Lim A,Jeon JP,Lee H,Lee KH,Lee SH,Berggren PO,Jeon JH,Ho WK

更新日期：2013-07-30 00:00:00

abstract：:T-cell anergy is a state of T cells that is hyporesponsive to stimulation via the T-cell receptor and costimulatory molecules and is thought to be important for self-tolerance. How T-cell anergy is regulated is still poorly understood. We report here that tuberous sclerosis (TSC)1 is critical for T-cell anergy. Defici...

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

authors： Xie DL,Wu J,Lou YL,Zhong XP

更新日期：2012-08-28 00:00:00

abstract：:Recent advances in coherent x-ray diffractive imaging have paved the way to reliable and quantitative imaging of noncompact specimens at the nanometer scale. Introduced a year ago, an advanced implementation of ptychographic coherent diffractive imaging has removed much of the previous limitations regarding sample pre...

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

authors： Giewekemeyer K,Thibault P,Kalbfleisch S,Beerlink A,Kewish CM,Dierolf M,Pfeiffer F,Salditt T

更新日期：2010-01-12 00:00:00

abstract：:We present a common allosteric mechanism for control of inflammatory and apoptotic caspases. Highly specific thiol-containing inhibitors of the human inflammatory caspase-1 were identified by using disulfide trapping, a method for site-directed small-molecule discovery. These compounds became trapped by forming a disu...

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

authors： Scheer JM,Romanowski MJ,Wells JA

更新日期：2006-05-16 00:00:00

abstract：:Magnetotactic bacteria synthesize highly uniform intracellular magnetite nanoparticles through the action of several key biomineralization proteins. These proteins are present in a unique lipid-bound organelle (the magnetosome) that functions as a nanosized reactor in which the particle is formed. A master regulator p...

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

authors： Rawlings AE,Bramble JP,Walker R,Bain J,Galloway JM,Staniland SS

更新日期：2014-11-11 00:00:00

abstract：:Visualizing macromolecular complexes by single-particle electron microscopy (EM) entails stringent biochemical purification, specimen preparation, low-dose imaging, and 3D image reconstruction. Here, we introduce the "monolayer purification" method, which employs nickel-nitrilotriacetic acid (Ni-NTA) functionalized li...

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

authors： Kelly DF,Dukovski D,Walz T

更新日期：2008-03-25 00:00:00

abstract：:Most higher plants develop severe toxicity symptoms when grown on ammonium (NH(4)(+)) as the sole nitrogen source. Recently, NH(4)(+) toxicity has been implicated as a cause of forest decline and even species extinction. Although mechanisms underlying NH(4)(+) toxicity have been extensively sought, the primary events ...

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

authors： Britto DT,Siddiqi MY,Glass AD,Kronzucker HJ

更新日期：2001-03-27 00:00:00