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11.
Tu-zhu-ye is a Korean crude drug for use as a diuretic but its plant source has not been identified. The present work has been attempted for identification of the original plant using specimens collected both at Seoul and Taegu, Korea, their mineral microstructures being examined after ashing the specimens by a low-temperature method with high-frequency oxygen plasma. A preliminary survey of the specimens with the naked eye suggested that the Tu-zhu-ye was near to Phyllostachys or its closely related bamboo species. Several specimens, namely, Phyllostachys heterocyclaMitf. var. pubescensOhwi, Phyllostachys nigraMunro var. henonisStapf, Phyllostachys bambusoidesSieb. et Zucc. and Bambusa multiplexRaeuschel were therefore ashed by the low-temperature method and the comparative microscopic studies with the resultant ashed tissues concluded that the “Tu-zhu-ye” from Seoul was perfectly identical with Phyllostachys nigraMunro var. henonisStapf. A further investigation is continued for the specimen from Taegu since it is different from any other specimens provided for the present work. 相似文献
12.
(Perfluoroalkyl)phenyliodonium sulfonates underwent novel oxy-perfluoroalkylation with alkenes under oxygen atmosphere in the presence of a base. 相似文献
13.
K Watanabe Y Nishimura T Nomoto N Umemoto Z Zhang B Zhang J Kuroyanagi Y Shimada T Shintou M Okano T Miyazaki T Imamura T Tanaka 《BMC neuroscience》2012,13(1):101
ABSTRACT: BACKGROUND: Successful delivery of compounds to the brain and retina is a challenge in the development of therapeutic drugs and imaging agents. This challenge arises because internalization of compounds into the brain and retina is restricted by the blood--brain barrier (BBB) and blood-retinal barrier (BRB), respectively. Simple and reliable in vivo assays are necessary to identify compounds that can easily cross the BBB and BRB. METHODS: We developed six fluorescent indoline derivatives (IDs) and examined their ability to cross the BBB and BRB in zebrafish by in vivo fluorescence imaging. These fluorescent IDs were administered to live zebrafish by immersing the zebrafish larvae at 7--8 days post fertilization in medium containing the ID, or by intracardiac injection. We also examined the effect of multidrug resistance proteins (MRPs) on the permeability of the BBB and BRB to the ID using MK571, a selective inhibitor of MRPs. RESULTS: The permeability of these barriers to fluorescent IDs administered by simple immersion was comparable to when administered by intracardiac injection. Thus, this finding supports the validity of drug administration by simple immersion for the assessment of BBB and BRB permeability to fluorescent IDs. Using this zebrafish model, we demonstrated that the length of the methylene chain in these fluorescent IDs significantly affected their ability to cross the BBB and BRB via MRPs. CONCLUSIONS: We demonstrated that in vivo assessment of the permeability of the BBB and BRB to fluorescent IDs could be simply and reliably performed using zebrafish. The structure of fluorescent IDs can be flexibly modified and, thus, the permeability of the BBB and BRB to a large number of IDs can be assessed using this zebrafish-based assay. The large amount of data acquired might be useful for in silico analysis to elucidate the precise mechanisms underlying the interactions between chemical structure and the efflux transporters at the BBB and BRB. In turn, understanding these mechanisms may lead to the efficient design of compounds targeting the brain and retina. 相似文献
14.
Dr. Shiori Umemoto Seongwang Im Dr. Jinhua Zhang Dr. Masaki Hagihara Dr. Asako Murata Yasue Harada Dr. Takeo Fukuzumi Takahiro Wazaki Shin‐ichi Sasaoka Prof. Dr. Kazuhiko Nakatani 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):9999-10008
A series of xanthone and thioxanthone derivatives with aminoalkoxy substituents were synthesized as fluorescent indicators for a displacement assay in the study of small‐molecule–RNA interactions. The RNA‐binding properties of these molecules were investigated in terms of the improved binding selectivity to the loop region in the RNA secondary structure relative to 2,7‐bis(2‐aminoethoxy)xanthone (X2S) by fluorimetric titration and displacement assay. An 11‐mer double‐stranded RNA and a hairpin RNA mimicking the stem loop IIB of Rev response element (RRE) RNA of HIV‐1 mRNA were used. The X2S derivatives with longer aminoalkyl substituents showed a higher affinity to the double‐stranded RNA than the parent molecule. Introduction of a methyl group on the aminoethoxy moiety of X2S effectively modulated the selectivity to the RNA secondary structure. Methyl group substitution at the C1′ position suppressed the binding to the loop regions. Substitution with two methyl groups on the amino nitrogen atom resulted in reducing the affinity to the double‐stranded region by a factor of 40 %. The effect of methyl substitution on the amino nitrogen atom was also observed for a thioxanthone derivative. Titration experiments, however, suggested that thioxanthone derivatives showed a more prominent tendency of multiple binding to RNA than xanthone derivatives. The selectivity index calculated from the affinity to the double‐stranded and loop regions suggested that the N,N‐dimethyl derivative of X2S would be suitable for the screening of small molecules binding to RRE. 相似文献
15.
16.
N Motohashi Y Nakamichi I Mori H Nishikawa J Umemoto 《Journal of chromatography. A》1988,435(2):335-342
The simultaneous analysis of the molecular weight and concentration of hyaluronic acid in biological samples using high-performance liquid chromatography with two gel permeation columns is described. The elution volumes of various molecular weights of hyaluronic acids were linearily related to the logarithms of their molecular weights up to 600,000. The concentration of hyaluronic acid could be determined in the range from 20 to 100 micrograms/ml, i.e., from 4 to 20 micrograms per 200 microliter injected. The method was applied to the analysis of several animal skin extracts and rabbit synovial fluid. Skin extracts from mouse, rat, guinea-pig and rabbit could be chromatographed without prior isolation and purification. Hyaluronic acids in skin were separated clearly from chondroitin sulphates and their concentrations were determined. The molecular weights were estimated simultaneously to be more than 10(6). Rabbit synovial fluids from intact joints and saline- and carrageenin-treated joints could be chromatographed directly. The chromatograms showed that the concentration of hyaluronic acid in carrageenin-treated synovial fluid is lower than that in saline-treated fluid and the molecular weight distribution is broader. This technique enabled the rapid analysis of hyaluronic acid present at low levels in biological samples. 相似文献
17.
(1,l-Dihydroperfluoroalkyl)phenyl- and --fluorophenyliodonium triflates and were synthesized by the reaction of l-bis(trifluoroacetoxy)iodo-1,l-dihydroperfluoroalkanes with triflic acid and benzene or fluorobenzene in 1,1,2-trichlorotrifluoroethane. The use of fluorosulfonic acid and sulfuric acid instead of triflic acid afforded (1,l-dihydroperfluoroalkyl) phenyliodonium fluorosulfonate and sulfate , respectively. Similarly, (1,1,ω-trihydroperfluoroalkyl)phenyliodonium triflate and 1,1,5,5-tetrahydroperfluoropentane-l,5-bisphenyliodonium triflate were synthesized. 相似文献
18.
A procedure for the determination of the uranium content of natural waters is presented. To 100 ml of natural waters, 200 ml of conc. hydrochloric acid are added and this solution is passed through a 6-ml column of Dowex 1-X8. The uranium is eluted with 60 ml of 0.1M hydrochloric acid, and the eluate is evaporated to dryness. The residue is subjected to the fission-track technique described previously. The uranium content of the river waters in Fukuoka City was determined. 相似文献
19.
Multiphoton ionization (MPI) fragmentation pattern of p-xylene is investigated as a function of laser power at 193 and 248 nm. The mass pattern at 193 nm suggests the presence of two reaction sequences and the occurrence of drastic rearrangement in the parent ion and also in the superexcited xylene before fragmentation. 相似文献
20.
A novel method for the synthesis of oligoribonucleotides using 1-(2-cyanoethoxy)ethyl (CEE) as a 2′-hydroxy protecting group has been developed. A CEE group was introduced to the 2′-position of N-acyl-3′,5′-O-silyl-protected ribonucleosides under acidic conditions in good yields. The 2′-O-CEE group was found to be stable in an aqueous or ethanolic ammonia and was quickly removed by treatment with anhydrous tetrabutylammonium fluoride (TBAF). A combination of the use of N-acyl and 2′-O-CEE protecting groups enabled a reliable and complete two-step deprotection, first with NH3–EtOH, then with TBAF in THF, without cleavage of internucleotidic linkages. 相似文献