DNA content of the cell nucleus in the macroalga <Emphasis Type="Italic">Porphyra yezoensis</Emphasis> (Rhodophyta)     

Kazuyo Matsuyama-Serisawa  Maki Yamamoto  Mariko Fujishita  Hirotoshi Endo  Yukihiko Serisawa  Satoshi Tabata  Shigeyuki Kawano  Naotsune Saga 《Fisheries Science》2007,73(3):738-740

  相似文献   

Logic circuits with carbon nanotube transistors     

Bachtold A  Hadley P  Nakanishi T  Dekker C 《Science (New York, N.Y.)》2001,294(5545):1317-1320

We demonstrate logic circuits with field-effect transistors based on single carbon nanotubes. Our device layout features local gates that provide excellent capacitive coupling between the gate and nanotube, enabling strong electrostatic doping of the nanotube from p-doping to n-doping and the study of the nonconventional long-range screening of charge along the one-dimensional nanotubes. The transistors show favorable device characteristics such as high gain (>10), a large on-off ratio (>10(5)), and room-temperature operation. Importantly, the local-gate layout allows for integration of multiple devices on a single chip. Indeed, we demonstrate one-, two-, and three-transistor circuits that exhibit a range of digital logic operations, such as an inverter, a logic NOR, a static random-access memory cell, and an ac ring oscillator.  相似文献   

Pavoninins: shark-repelling ichthyotoxins from the defense secretion of the pacific sole     

Tachibana K  Sakaitanai M  Nakanishi K 《Science (New York, N.Y.)》1984,226(4675):703-705

A series of ichthyotoxic and hemolytic steroid aminoglycosides, pavoninins-1, to -6, has been isolated from the defense secretion of the sole Pardachirus pavoninus, and their respective chemical structures have been established by spectroscopic studies and chemical conversions. The pavoninins exert repellent activity against sharks and are considered to be the factors responsible for the predator-repelling property of the sole.  相似文献   

Melittin-Like Peptides from the Shark-Repelling Defense Secretion of the Sole Pardachirus pavoninus     

Thompson SA  Tachibana K  Nakanishi K  Kubota I 《Science (New York, N.Y.)》1986,233(4761):341-343

Three ichthyotoxic peptides, pardaxins P-I to P-3, have been isolated from the defense secretion of the sole Pardachirus pavoninus. Pavoninins, the steroid glycosides with shark-repelling ability, had previously been isolated therefrom. Each pardaxin consists of 33 amino acid residues having a distinctly hydrophilic carboxyl terminal region and a predominantly hydrophobic remainder; the pardaxin is thus strongly surfactant. These peptides show marked physical and pharmacological similarities to melittin, the major active constituent of bee venom, yet they lack sequence homology. They are probably also responsible for the predator-repelling property of the sole.  相似文献   

Phenoxyethanol: protein preservative for taxonomists     

M Nakanishi  A C Wilson  R A Nolan  G C Gorman  G S Bailey 《Science (New York, N.Y.)》1969,163(868):681-683

Pieces of chicken heart or skeletal muscle were placed in a dilute solution of the antimicrobial agent 2-phenoxyethanol and stored at room temperature. Under these conditions, the serum albumin, lactate dehydrogenase, and malate dehydrogenase in these tissues survived in easily detectable amounts for at least 2 weeks. The surviving proteins appeared to be identical with those of fresh tissues in physical, catalytic, and immunological properties. Phenoxyethanol also preserved heart and muscle proteins of representatives of other vertebrate classes. Tissue samples collected in the analysis by biochemical taxonomists.  相似文献   

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission     

Yurimoto H  Abe K  Abe M  Ebihara M  Fujimura A  Hashiguchi M  Hashizume K  Ireland TR  Itoh S  Katayama J  Kato C  Kawaguchi J  Kawasaki N  Kitajima F  Kobayashi S  Meike T  Mukai T  Nagao K  Nakamura T  Naraoka H  Noguchi T  Okazaki R  Park C  Sakamoto N  Seto Y  Takei M  Tsuchiyama A  Uesugi M  Wakaki S  Yada T  Yamamoto K  Yoshikawa M  Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.  相似文献   

Simultaneous gas chromatographic determination of dibutyltin and tributyltin compounds in biological and sediment samples   总被引：1，自引：0，他引：1  

T Tsuda  H Nakanishi  T Morita  J Takebayashi 《Journal of the Association of Official Analytical Chemists》1986,69(6):981-984

A method is described for the simultaneous determination of nanogram amounts of dibutyltin and tributyltin compounds in biological and sediment samples. These compounds are converted to the corresponding chlorides with HCl, extracted with ethyl acetate-hexane (3 + 2) for biological samples and with hexane for sediment samples, and hydrogenated with sodium borohydride. The corresponding hydrides, Bu2SnH2 and Bu3SnH, are detected by electron-capture gas chromatography after cleanup by silica gel column chromatography. Detection limits are 1.0-2.0 and 0.5-1.0 ng/g, respectively, for biological and sediment samples.  相似文献   

Simultaneous gas chromatographic determination of carboxylic acids in soft drinks and jams     

T Tsuda  H Nakanishi  T Morita  J Takebayashi 《Journal of the Association of Official Analytical Chemists》1985,68(5):902-905

A method was developed for simultaneous gas chromatographic determination of sorbic acid, dehydroacetic acid, and benzoic acid used as preservatives, and succinic acid, fumaric acid, malic acid, and tartaric acid used as acidulants in soft drinks and jams. A sample was dissolved in NH4OH-NH4Cl pH 9 buffer solution, and an aliquot of the solution was passed through a QAE-Sephadex A 25 column. The column was washed with water, and the carboxylic acids were eluted with 0.1N HCl. Sorbic acid, dehydroacetic acid, and benzoic acid were extracted with ethyl ether-petroleum ether (1 + 1), and determined on a 5% DEGS + 1% H3PO4 column. Succinic acid, fumaric acid, malic acid, and tartaric acid in the lower layer were derivatized with N,O-bis(trimethylsilyl)acetamide and trimethylchlorosilane, and determined on a 3% SE-30 column. Recoveries from soft drink and jam samples fortified with 0.1% each of 7 carboxylic acids ranged from 92.4 to 102.6% for preservatives, and from 88.1 to 103.2% for acidulants.  相似文献   

Bioavailability of oral ivermectin in dog     

K Kojima  K Yamamoto  H Katae  Y Nakanishi 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1987,49(5):899-900

  相似文献   

Ability of CD8+ T cell anti-feline immunodeficiency virus (FIV) activity and FIV proviral DNA load in mononuclear cells in FIV-infected cats     

Hohdatsu T  Nakanishi T  Saito I  Koyama H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(1):129-131

We investigated the relationship between CD8+ T cell anti-feline immunodeficiency virus (FIV) activity and FIV proviral DNA load integrated in mononuclear cells. The anti-FIV activity and the proviral DNA load were correlated, and the number of proviral DNA copies was high in cats with decreased anti-FIV activity. Particularly, no anti-FIV activity was detected in the cats staged as having an acquired immunodeficiency syndrome (AIDS)-related complex or AIDS, and the number of proviral DNA copies was obviously increased compared to those in the cats in the asymptomatic stage. These results suggest that decreased anti-FIV activity destroys the control of in vivo FIV replication, which leads to an increased proviral DNA load with the progression of the clinical stage of disease.  相似文献