WordNet

any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water; "bases include oxides and hydroxides of metals and ammonia" (同)alkali
(numeration system) the positive integer that is equivalent to one in the next higher counting place; "10 is the radix of the decimal system" (同)radix
the bottom side of a geometric figure from which the altitude can be constructed; "the base of the triangle"
situate as a center of operations; "we will base this project in the new lab"
a place that the runner must touch before scoring; "he scrambled to get back to the bag" (同)bag
installation from which a military force initiates operations; "the attack wiped out our forward bases" (同)base of operations
a support or foundation; "the base of the lamp" (同)pedestal, stand
(electronics) the part of a transistor that separates the emitter from the collector
a flat bottom on which something is intended to sit; "a tub should sit on its own base"
the principal ingredient of a mixture; "glycerinated gelatin is used as a base for many ointments"; "he told the painter that he wanted a yellow base with just a hint of green"; "everything she cooked seemed to have rice as the base"
the place where you are stationed and from which missions start and end (同)home
(anatomy) the part of an organ nearest its point of attachment; "the base of the skull"
the bottom or lowest part; "the base of the mountain"
illegitimate (同)baseborn
of low birth or station (`base is archaic in this sense); "baseborn wretches with dirty faces"; "of humble (or lowly) birth" (同)baseborn, humble, lowly
not adhering to ethical or moral principles; "base and unpatriotic motives"; "a base, degrading way of life"; "cheating is dishonorable"; "they considered colonialism immoral"; "unethical practices in handling public funds" (同)immoral
having or showing an ignoble lack of honor or morality; "that liberal obedience without which your army would be a base rabble"- Edmund Burke; "taking a mean advantage"; "chokd with ambition of the meaner sort"- Shakespeare; "something essentially vulgar and meanspirited in politics" (同)mean, meanspirited
(used of metals) consisting of or alloyed with inferior metal; "base coins of aluminum"; "a base metal"
debased; not genuine; "an attempt to eliminate the base coinage"
having a base; "firmly based ice"
having a base of operations (often used as a combining form); "a locally based business"; "an Atlanta-based company"; "carrier-based planes"

PrepTutorEJDIC

《文》(人や人の行動・孝えが)『卑しい』,下劣な / (金属が)質の劣った;(貨幣が)粗悪な
『基礎』,根拠 / 『基部』,基底,土台 / 『根拠地』,基地 / (野球の)塁,ベース / 主成分;塩基(酸と反応シテ塩(官)を生じる化合物) / (数学で図形の)底;底辺;基線 / (…に)…‘の'『基礎をおく』《+『名』+『on』(『upon』)+『名』》
ひどい,すごい / ひどく,すごく
basisの複数形

UpToDate Contents

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1. 出産時の臍帯血酸塩基分析 umbilical cord blood acid base analysis at delivery
2. 単純性および混合性酸塩基障害 simple and mixed acid base disorders
3. 酸塩基障害におけるカリウムバランス potassium balance in acid base disorders
4. 動脈血液ガス arterial blood gases
5. 中手骨基部骨折 metacarpal base fractures

English Journal

Molecular recognition and modification of the 30S ribosome by the aminoglycoside-resistance methyltransferase NpmA.

Dunkle JA1, Vinal K, Desai PM, Zelinskaya N, Savic M, West DM, Conn GL, Dunham CM.Author information 1Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322.AbstractAminoglycosides are potent, broad spectrum, ribosome-targeting antibacterials whose clinical efficacy is seriously threatened by multiple resistance mechanisms. Here, we report the structural basis for 30S recognition by the novel plasmid-mediated aminoglycoside-resistance rRNA methyltransferase A (NpmA). These studies are supported by biochemical and functional assays that define the molecular features necessary for NpmA to catalyze m1A1408 modification and confer resistance. The requirement for the mature 30S as a substrate for NpmA is clearly explained by its recognition of four disparate 16S rRNA helices brought into proximity by 30S assembly. Our structure captures a "precatalytic state" in which multiple structural reorganizations orient functionally critical residues to flip A1408 from helix 44 and position it precisely in a remodeled active site for methylation. Our findings provide a new molecular framework for the activity of aminoglycoside-resistance rRNA methyltransferases that may serve as a functional paradigm for other modification enzymes acting late in 30S biogenesis.
Proceedings of the National Academy of Sciences of the United States of America.Proc Natl Acad Sci U S A.2014 Apr 9. [Epub ahead of print]
Aminoglycosides are potent, broad spectrum, ribosome-targeting antibacterials whose clinical efficacy is seriously threatened by multiple resistance mechanisms. Here, we report the structural basis for 30S recognition by the novel plasmid-mediated aminoglycoside-resistance rRNA methyltransferase A (
PMID 24717845

Crystal structure of the 5hmC specific endonuclease PvuRts1I.

Kazrani AA1, Kowalska M, Czapinska H, Bochtler M.Author information 1International Institute of Molecular and Cell Biology, Trojdena 4, 02109 Warsaw, Poland.AbstractPvuRts1I is a prototype for a larger family of restriction endonucleases that cleave DNA containing 5-hydroxymethylcytosine (5hmC) or 5-glucosylhydroxymethylcytosine (5ghmC), but not 5-methylcytosine (5mC) or cytosine. Here, we report a crystal structure of the enzyme at 2.35 Å resolution. Although the protein has been crystallized in the absence of DNA, the structure is very informative. It shows that PvuRts1I consists of an N-terminal, atypical PD-(D/E)XK catalytic domain and a C-terminal SRA domain that might accommodate a flipped 5hmC or 5ghmC base. Changes to predicted catalytic residues of the PD-(D/E)XK domain or to the putative pocket for a flipped base abolish catalytic activity. Surprisingly, fluorescence changes indicative of base flipping are not observed when PvuRts1I is added to DNA substrates containing pyrrolocytosine in place of 5hmC (5ghmC). Despite this caveat, the structure suggests a model for PvuRts1I activity and presents opportunities for protein engineering to alter the enzyme properties for biotechnological applications.
Nucleic acids research.Nucleic Acids Res.2014 Mar 25. [Epub ahead of print]
PvuRts1I is a prototype for a larger family of restriction endonucleases that cleave DNA containing 5-hydroxymethylcytosine (5hmC) or 5-glucosylhydroxymethylcytosine (5ghmC), but not 5-methylcytosine (5mC) or cytosine. Here, we report a crystal structure of the enzyme at 2.35 Å resolution. Although
PMID 24634440

Dual base-flipping of cytosines in a CpG dinucleotide sequence.

Bianchi C1, Zangi R2.Author information 1Department of Organic Chemistry I, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018 San Sebastian, Spain.2Department of Organic Chemistry I, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, 20018 San Sebastian, Spain; IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain. Electronic address: r.zangi@ikerbasque.org.AbstractSimultaneous flipped-out conformation of two neighboring bases on opposite strands of DNAs has been observed in several X-ray structures. It has also been detected for two cytosines on opposite strands in different contexts of CpG sites. In this paper, we study by MD simulations the dual base flipping of the two cytosines in hemi-methylated CpG site. We calculate the potential of mean force of flipping-out the unmethylated cytosine in three model systems. The first is for DNA bound to the regulatory protein UHRF1. In this case, the methyl-cytosine on the complementary strand is flipped-out into the binding pocket of the SRA domain of the protein. The other two systems are for unbound DNAs in which the methyl-cytosine is either intra-helical or extra-helical. We find that when the methyl-cytosine is flipped-out it is easier to flip-out the other (unmethylated) cytosine on the opposite strand by about 14-16kJ/mol. This lower penalty for dual-base flipping is observed for both the bound and unbound states of the DNA. Analyses of the hydrogen bond network and stacking interactions within the CpG site indicate that the lower penalty is due to stabilization of the dual-base flipped-out conformation via interactions involving the orphan guanines. The results presented in this paper suggest that the extra-helical conformation of the methyl-cytosine recognized by UHRF1 can facilitate the base-flipping process of the target cytosine to be methylated by Dnmt1.
Biophysical chemistry.Biophys Chem.2014 Mar-Apr;187-188:14-22. doi: 10.1016/j.bpc.2013.12.005. Epub 2013 Dec 29.
Simultaneous flipped-out conformation of two neighboring bases on opposite strands of DNAs has been observed in several X-ray structures. It has also been detected for two cytosines on opposite strands in different contexts of CpG sites. In this paper, we study by MD simulations the dual base flippi
PMID 24469333

Japanese Journal

基板バイポーラ効果によるSEUとMCUの発生機構の検討(製造性考慮設計,システムオンシリコンを支える設計技術)

濱中力,古田潤,牧野紘明 [他],小林和淑,小野寺秀俊
電子情報通信学会技術研究報告. VLD, VLSI設計技術 109(462), 25-30, 2010-03-03
集積化が進むにつれ素子固有のエラー耐性は低下し,1bitが反転するSEU(Single Event Upset),複数のビットが同時に反転するMCU(Multi-Cell upset)が問題となっている。MCUは,中性子,α線などにより発生した電荷が複数のノードに分配されて起こるとされているが,近年,Wellもしくは基板をべースとした寄生バイポーラトランジスタ効果もMCUの発生要因として挙げられて …
NAID 110008001480

Bullied no more : When DNA shoves proteins around(Knots and soft-matter physics: Topology of polymers and related topics in physics, mathematics and biology)

Randall Graham L.,Sumners DeWitt L.,Pettitt B. Montgomery,Zechiedrich Lynn
物性研究 92(1), 80-83, 2009-04-20
… Instead, DNA in cells has topology, and topology affects: curvature, twist, kinking, base flipping, denaturation, and counterion concentrations, in addition to the likelihood that two DNA helices come together to form DNA juxtapositions. …
NAID 120005197854

Diffusion of supercoiled DNA and the effect of base-flipping by Brownian dynamics(Knots and soft-matter physics: Topology of polymers and related topics in physics, mathematics and biology)

Kanaeda Naoko,Deguchi Tetsuo,Zechiedrich Lynn
物性研究 92(1), 145-146, 2009-04-20
… さらに我々はbase-flippingの拡散に与える影響を調べるため、FENEバネでつながれたペアの1つを切り離した。 … その結果拡散は、base-flippingを考慮しないモデルに比較して遅くなることが分かった。 …
NAID 120005197833