DNA amplification patterns in maize endosperm nuclei during kernel development.

abstract：:We report an approach for the detection of magnetic resonance imaging without superconducting magnets and cryogenics: optical atomic magnetometry. This technique possesses a high sensitivity independent of the strength of the static magnetic field, extending the applicability of magnetic resonance imaging to low magne...

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

authors： Xu S,Yashchuk VV,Donaldson MH,Rochester SM,Budker D,Pines A

更新日期：2006-08-22 00:00:00

abstract：:Neural circuits are generated by precisely ordered synaptic connections among neurons, and this process is thought to rely on the ability of neurons to recognize specific partners. However, it is also known that neurons promiscuously form synapses with nonspecific partners, in particular when cultured in vitro, causin...

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

authors： Ito S,Takeichi M

更新日期：2009-08-04 00:00:00

abstract：:Glycogen synthase kinase 3 (GSK-3) is implicated in multiple biological processes including metabolism, gene expression, cell fate determination, proliferation, and survival. GSK-3 activity is inhibited through phosphorylation of serine 21 in GSK-3 alpha and serine 9 in GSK-3 beta. These serine residues of GSK-3 have ...

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

authors： Fang X,Yu SX,Lu Y,Bast RC Jr,Woodgett JR,Mills GB

更新日期：2000-10-24 00:00:00

abstract：:The survival of motor neurons is controlled by multiple factors that regulate different aspects of their physiology. The identification of these factors is important because of their relationship to motor neuron disease. We investigate here whether Mullerian Inhibiting Substance (MIS) is a motor neuron survival factor...

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

authors： Wang PY,Koishi K,McGeachie AB,Kimber M,Maclaughlin DT,Donahoe PK,McLennan IS

更新日期：2005-11-08 00:00:00

abstract：:The emergence of multidrug-resistant (MDR) tuberculosis (TB) highlights the urgent need to understand the mechanisms of resistance to the drugs used to treat this disease. The aminoglycosides kanamycin and amikacin are important bactericidal drugs used to treat MDR TB, and resistance to one or both of these drugs is a...

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

authors： Zaunbrecher MA,Sikes RD Jr,Metchock B,Shinnick TM,Posey JE

更新日期：2009-11-24 00:00:00

abstract：:Attending to a stimulus is known to enhance the neural responses to that stimulus. Recent experiments on visual attention have shown that this modulation can have object-based characteristics, such that, when certain parts of a visual object are attended, other parts automatically also receive enhanced processing. Her...

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

authors： Busse L,Roberts KC,Crist RE,Weissman DH,Woldorff MG

更新日期：2005-12-20 00:00:00

abstract：:Cholinergic pathways serve important functions in learning and memory processes, and deficits in cholinergic transmission occur in Alzheimer disease (AD). A subset of muscarinic cholinergic receptors are linked to G-proteins that activate phospholipase C, resulting in the liberation of inositol trisphosphate and Ca2+ ...

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

authors： Kelly JF,Furukawa K,Barger SW,Rengen MR,Mark RJ,Blanc EM,Roth GS,Mattson MP

更新日期：1996-06-25 00:00:00

abstract：:Covalently cross-linked pilus polymers displayed on the cell surface of Gram-positive bacteria are assembled by class C sortase enzymes. These pilus-specific transpeptidases located on the bacterial membrane catalyze a two-step protein ligation reaction, first cleaving the LPXTG motif of one pilin protomer to form an ...

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

authors： Chang C,Amer BR,Osipiuk J,McConnell SA,Huang IH,Hsieh V,Fu J,Nguyen HH,Muroski J,Flores E,Ogorzalek Loo RR,Loo JA,Putkey JA,Joachimiak A,Das A,Clubb RT,Ton-That H

更新日期：2018-06-12 00:00:00

abstract：:T cells are activated physiologically by triggering the T-cell receptor-CD3 complex. There is evidence that invariant accessory molecules on the T-cell membrane (CD8 and CD4) are involved in the major histocompatibility complex-restricted recognition process. Moreover, binding and crosslinking of these accessory molec...

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

authors： Samstag Y,Emmrich F,Staehelin T

更新日期：1988-12-01 00:00:00

abstract：:A key question in clarifying human-environment interactions is how dynamic complexity develops across integrative scales from molecular to population and global levels. Apart from its public health importance, measles is an excellent test bed for such an analysis. Simple mechanistic models have successfully illuminate...

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

authors： Becker AD,Birger RB,Teillant A,Gastanaduy PA,Wallace GS,Grenfell BT

更新日期：2016-12-20 00:00:00

abstract：:The diabetogenic agent alloxan exerts a preferential cytotoxic effect on the pancreatic B cell. The determinants of such a tissue specificity were investigated. Alloxan accumulated rapidly in liver and pancreatic islets but much more slowly in muscle. The activity of glutathione peroxidase and the resistance to exogen...

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

authors： Malaisse WJ,Malaisse-Lagae F,Sener A,Pipeleers DG

更新日期：1982-02-01 00:00:00

abstract：:Inflammation plays an important role in pathological angiogenesis. Receptor-interacting protein 1 (RIP1) is highly expressed in inflammatory cells and is known to play an important role in the regulation of apoptosis, necroptosis, and inflammation; however, a comprehensive description of its role in angiogenesis remai...

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

authors： Ueta T,Ishihara K,Notomi S,Lee JJ,Maidana DE,Efstathiou NE,Murakami Y,Hasegawa E,Azuma K,Toyono T,Paschalis EI,Aihara M,Miller JW,Vavvas DG

更新日期：2019-11-19 00:00:00

abstract：:The distribution of actin stress fibers in normal and regenerating (after endothelial denudation by means of a balloon catheter) rabbit aortic endothelial cells has been studied by means of immunofluorescence with human actin autoantibodies on en face endothelial cell preparations. Our results show that: (i) under nor...

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

authors： Gabbiani G,Gabbiani F,Lombardi D,Schwartz SM

更新日期：1983-04-01 00:00:00

abstract：:The Escherichia coli recQ gene, a member of the RecF recombination gene family, was set in an overexpression plasmid, and its product was purified to near-homogeneity. The purified RecQ protein exhibited a DNA-dependent ATPase and a helicase activity. Without DNA, no ATPase activity was detected. The capacity as ATPas...

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

authors： Umezu K,Nakayama K,Nakayama H

更新日期：1990-07-01 00:00:00

abstract：:We have selected from a mixture of random polynucleotides an RNA that is able to replicate in the presence of the DNA-dependent RNA polymerase of Escherichia coli, provided the medium contains Mn(2+) and ITP, in addition to ATP, CTP, and UTP. The RNA consists of a chain of about 125 (+/-25) nucleotides and appears to ...

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

authors： Biebricher CK,Orgel LE

更新日期：1973-03-01 00:00:00

abstract：:The superparamagnetic behavior of very small particles of metallic iron (ca 1.5 nm), with about half of their atoms at the surface, is changed reversibly by adsorption and desorption of hydrogen below the superparamagnetic transition temperature. The change after adsorption implies a lowering of the anisotropy energy ...

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

authors： Boudart M,Dumesic JA,Topsøe H

更新日期：1977-03-01 00:00:00

abstract：:The origin-binding protein (OBP) from herpes simplex virus 1 is a member of the SF2 helicase superfamily and is required for the initiation of DNA synthesis from a viral origin of DNA replication (oriS). The high-affinity binding sites for OBP in oriS, boxes I and II, are separated by an A+T-rich spacer. We used the g...

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

authors： Gustafsson CM,Hammarsten O,Falkenberg M,Elias P

更新日期：1994-05-24 00:00:00

abstract：:Most current diagnostic tests for tuberculosis do not reveal the species or strain of pathogen causing pulmonary infection, which can lead to inappropriate treatment regimens and the spread of disease. Here, we report an assay for mycobacterial strain assignment based on genetically conserved mycobacterial sulfatases....

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

authors： Beatty KE,Williams M,Carlson BL,Swarts BM,Warren RM,van Helden PD,Bertozzi CR

更新日期：2013-08-06 00:00:00

abstract：:We isolated mutant strains of the facultative anaerobe Salmonella typhimurium that grow either aerobically or anaerobically. Strict anaerobic mutants contained a defective DNA topoisomerase I gene (topI), while strict aerobic mutants contained a defective DNA gyrase subunit A gene (gyrA, also nalA). Topoisomerase I ac...

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

authors： Yamamoto N,Droffner ML

更新日期：1985-04-01 00:00:00

abstract：:Multiple drug resistance of tumor cells is a common problem in cancer therapy. We have demonstrated that membrane vesicles from highly multidrug-resistant human KB carcinoma cell lines exhibit increased specific and saturable binding of vinblastine. To identify the molecules that bind vinblastine, membrane vesicles fr...

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

authors： Cornwell MM,Safa AR,Felsted RL,Gottesman MM,Pastan I

更新日期：1986-06-01 00:00:00

abstract：:Endogenous retroviruses (ERVs) are the remnants of ancient retroviral infections of germ cells and have been maintained in whole or part as heritable genomic elements. The last known endogenization events occurred several million years ago, and therefore stepwise analysis of retroviral endogenization has not been poss...

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

authors： Oliveira NM,Satija H,Kouwenhoven IA,Eiden MV

更新日期：2007-10-30 00:00:00

abstract：:The human MHC represents the strongest susceptibility locus for autoimmune diseases. However, the identification of the true predisposing gene(s) has been handicapped by the strong linkage disequilibrium across the region. Furthermore, most studies to date have been limited to the examination of a subset of the HLA an...

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

authors： International MHC and Autoimmunity Genetics Network.,Rioux JD,Goyette P,Vyse TJ,Hammarström L,Fernando MM,Green T,De Jager PL,Foisy S,Wang J,de Bakker PI,Leslie S,McVean G,Padyukov L,Alfredsson L,Annese V,Hafler DA,Pan-

更新日期：2009-11-03 00:00:00

abstract：:A Ca2+-channel blocker derived from funnel-web spider toxin (FTX) has made it possible to define and study the ionic channels responsible for the Ca2+ conductance in mammalian Purkinje cell neurons and the preterminal in squid giant synapse. In cerebellar slices, FTX blocked Ca2+-dependent spikes in Purkinje cells, re...

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

authors： Llinás R,Sugimori M,Lin JW,Cherksey B

更新日期：1989-03-01 00:00:00

abstract：:The RNA world hypothesis presumes that RNA will be competent for varied essential cellular functions. One such indispensable cell function is regulation of membrane permeability. Though this was not a known RNA activity, selection-amplification yielded RNAs that bound phosphatidylcholine:cholesterol liposomes. At leas...

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

authors： Khvorova A,Kwak YG,Tamkun M,Majerfeld I,Yarus M

更新日期：1999-09-14 00:00:00

abstract：:The nucleus accumbens is considered a critical target of the action of drugs of abuse. In this nucleus a "shell" and a "core" have been distinguished on the basis of anatomical and histochemical criteria. The present study investigated the effect in freely moving rats of intravenous cocaine, amphetamine, and morphine ...

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

authors： Pontieri FE,Tanda G,Di Chiara G

更新日期：1995-12-19 00:00:00

abstract：:The mechanisms that regulate insulin secretion were investigated using capacitance measurements of exocytosis in single beta cells maintained in tissue culture. Exocytosis was stimulated by voltage-clamp depolarizations to activate the voltage-dependent Ca2+ channels that mediate Ca2+ influx into the beta cell. Under ...

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

authors： Ammälä C,Eliasson L,Bokvist K,Berggren PO,Honkanen RE,Sjöholm A,Rorsman P

更新日期：1994-05-10 00:00:00

abstract：:We have examined the role of a cell surface galactosyltransferase, laminin, and laminin-binding protein (receptor) in the invasion of clonal derivatives of a murine adrenal carcinoma cell line. Although a 10-fold variation was found in the ability to invade a reconstituted basement membrane matrix, levels of intracell...

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

authors： Penno MB,Passaniti A,Fridman R,Hart GW,Jordan C,Kumar S,Scott AF

更新日期：1989-08-01 00:00:00

abstract：:The tissue-specific, cell-aggregating component of embryonic neural retina cells was purified from the retina cell-aggregating factor and characterized as a glycoprotein. Its molecular weight in solution is in the range of 50,000, and it contains 10-15% carbohydrate. The amino-acid and carbohydrate compositions have b...

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

authors： Hausman RE,Moscona AA

更新日期：1975-03-01 00:00:00

abstract：:Influenza virus neuraminidase (NA; EC 3.2.1.18) possesses a signal-anchor hydrophobic domain at the amino terminus. To characterize the nature of this signal-anchor domain we have introduced single amino acid changes in this domain by oligonucleotide-directed mutagenesis. Three mutant NA proteins that were synthesized...

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

authors： Sivasubramanian N,Nayak DP

更新日期：1987-01-01 00:00:00

abstract：:Genome duplication followed by massive gene loss has permanently shaped the genomes of many higher eukaryotes, particularly angiosperms. It has long been believed that a primary advantage of genome duplication is the opportunity for the evolution of genes with new functions by modification of duplicated genes. If so, ...

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

authors： Chapman BA,Bowers JE,Feltus FA,Paterson AH

更新日期：2006-02-21 00:00:00