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611.
The isolation and structure elucidation of belamide A from the marine cyanobacterium Symploca sp. is described. Belamide A is a highly methylated linear tetrapeptide with structural analogy to the important linear peptides dolastatins 10 and 15. Disruption of the microtubule network in A-10 cells was observed at 20 μM and displayed classic tubulin destabilizing antimitotic characteristics. The moderate cytotoxicity of belamide A (IC50 0.74 μM vs HCT-116 colon cancer line) provides new insights into structure-activity relationships for this drug class. 相似文献
612.
Hongwei Liu Teruaki Nishikawa Kazuo Tachibana Hiroshi Nagai Michio Namikoshi 《Tetrahedron letters》2004,45(38):7015-7017
A novel tribenzotetrathiepin alkaloid, named lissoclibadin 1 (1), has been isolated from the ascidian Lissoclinum sp. (cf. L. badium Monniot and Monniot, 1996). The gross structure was assigned on the basis of the spectral data, and one of two possible isomers was selected by the computational modeling study. Lissoclibadin 1 inhibited the growth of the marine bacterium Ruegeria atlantica (15.2 mm at 20 μg/disk). 相似文献
613.
S. Roussos M. Raimbault J. -P. Prebois B. K. Lonsane 《Applied biochemistry and biotechnology》1993,42(1):37-52
A novel design of a large scale solid state fermenter, designated asZymotis—the condensed term based on Greek word “Zymothiras,” which means the fermenter, offers efficient control of various fermentation parameters such as temperature, moisture, and
aeration of the fermenting moist solids. A large quantity of metabolic heat can be easily removed by the novel cooling system
employed. The unit can be operated at different capacities simply by adding or removing the compartments. Its evaluation at
different capacities for cellulase production byTrichoderma harzianum gave similar performance as in the parallel fermentation under optimized parameters in laboratory scale column fermenter
of high efficiency. The design is entirely different from all the known fermenter designs and is of potential promise in facilitating
scale up of solid state fermentation for leading to industrial exploitation and harvesting numerous socioeconomic advantages
of the system. 相似文献
614.
Murae T Takamatsu Y Muraoka R Endoh S Yamauchi N 《Journal of mass spectrometry : JMS》2002,37(2):209-215
Calditocaldarchaeol (neutral tetraether lipid) from Sulfolobus acidocaldarius (acidothermophilic archaea) and intact total lipid from the thermoacidophilic archaea Sulfolobus sp. was examined by electrospray ionization time-of-flight mass spectrometry in the negative-ion mode using high resolution. When the sample was injected as a solution in a 3:1 mixture of methanol (MeOH) and chloroform (CHCl(3)) using an infusion system, the total ether lipid afforded molecular-related ions as [M - H](-) for acidic polar lipids containing a phosphoric or sulfuric group, and as [M + Cl](-) ion for neutral glycolipids. The attachment of chloride was confirmed by the observation of [M + Br](-) ion, instead of [M + Cl](-) ion, when a 3:1 mixture of MeOH and CHBr(3) was used in place of MeOH-CHCl(3) as the solvent. The composition of tetraether neutral glycolipids that are different from each other only in the number of five-membered rings in the isoprenoid chain was determined on the basis of the isotope-resolved mass spectrum of [M + Cl](-) ions. As for acidic tetraether lipids, molecular-related ions [M - H](-)) were not observed when the 3:1 MeOH-CHBr(3) mixture was used as the solvent. These results together afforded a facile method of distinguishing neutral from acidic tetraether lipids in intact total lipids of acidothermophilic archaea. This method was applied to determine the difference of the number of five-membered rings in isoprenyl chains of neutral tetraether glycolipids yielded by the Sulfolobus sp. grown at different temperatures. Discrimination of neutral tetraether glycolipids from acidic tetraether lipids in the total lipids obtained from Thermoplasma sp. was also achieved by this method. 相似文献
615.
Functional analysis of a hybrid endoglucanase of bacterial origin having a cellulose binding domain from a fungal exoglucanase 总被引:2,自引:0,他引:2
Kim H Goto M Jeong HJ Jung KH Kwon I Furukawa K 《Applied biochemistry and biotechnology》1998,75(2-3):193-204
A cellulose binding domain (CBD) of an endo-β-l,4-glucanase (Ben) from the bacteriumBacillus subtilis BSE616 was replaced with the CBD of exoglucanase I (TexI) from the fungusTrichoderma viride HK-75. The resultant hybrid enzyme Ben’-CBDTexI, comprising the catalytic domain (Ben’) of Ben and the CBD (CBDTexI) of TexI, was highly expressed at 20% of the total protein inEscherichia coli. The molecular mass of the hybrid enzyme was estimated to be ca. 38 kDa by SDS-PAGE, which was in good agreement with that
calculated from 305 amino acids of Ben and 42 amino acids of CBDTexI. The hybrid enzyme exhibited almost the same activity as that of the original Ben toward soluble substrates, such as cellooligosaccharides.
The hybrid enzyme showed higher binding ability and hydrolysis activity toward microcrystalline cellulose (Avicel), even though
the length of the CBD of TexI was four times smaller than that of Ben. The hybrid enzyme was more resistant to tryptic digestion
than the original Ben. The efficient binding ability of the hybrid enzyme to Avicel permitted purification of the enzyme using
an Avicel-affinity column to the extent of ca. 90% purity. 相似文献
616.
M. P. Sobolevskaya V. A. Denisenko A. S. Moiseenko L. S. Shevchenko N. I. Menzorova Yu. T. Sibirtsev N. Yu. Kim T. A. Kuznetsova 《Russian Chemical Bulletin》2007,56(4):838-840
New 3-(4-hydroxybenzyl)piperazine-2,5-dione, together with the known N-[2-(4-hydroxy-phenyl)ethyl]acetamide (N-acetyltyramine), was isolated for the first time from the marine actinobacterium Streptomyces sp. The chemical structures of these compounds were determined by NMR spectroscopy and mass spectrometry. The cytotoxic activities
of the compounds were estimated from their effects on sperm and eggs of the sea urchin Strongylocentrotus intermedius.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 807–809, April, 2007. 相似文献
617.
A novel modulator of multidrug resistance (MDR) in tumor cells, kendarimide A (1), was isolated from an Indonesian marine sponge of Haliclona sp. Compound 1 reversed MDR in KB-C2 cells mediated by P-glycoprotein (P-gp) at a 6 μM concentration, and the chemical structure of 1 was characterized to be a linear peptide composed of N-methylpyroglutamic acid (pyroMeGlu), N-methylated eight-membered cysteinyl-cysteine (ox-[MeCys-MeCys]) together with many N-methyl amino acid residues. The amino acid sequence of 1 was determined by 2D NMR and FAB MS analysis. The absolute configuration of the amino acid residues in 1 except for the MeCys part was determined to be l-form respectively, based on interpretation of the HPLC analysis of Marfey's derivatives of the hydrolysates of 1 and the synthetic method for the pyroMeGlu residue. 相似文献
618.
Ting Shi Li Zheng Xiang-Qian Li Jia-Jia Dai Yi-Ting Zhang Yan-Yan Yu Wen-Peng Hu Da-Yong Shi 《Molecules (Basel, Switzerland)》2021,26(9)
The species Pseudogymnoascus is known as a psychrophilic pathogenic fungus which is ubiquitously distributed in Antarctica. While the studies of its secondary metabolites are infrequent. Systematic research of the metabolites of the Antarctic fungus Pseudogymnoascus sp. HSX2#-11 led to the isolation of one new pyridine derivative, 4-(2-methoxycarbonyl-ethyl)-pyridine-2-carboxylic acid methyl ester (1), together with one pyrimidine, thymine (2), and eight diketopiperazines, cyclo-(dehydroAla-l-Val) (3), cyclo-(dehydroAla-l-Ile) (4), cyclo-(dehydroAla-l-Leu) (5), cyclo-(dehydroAla-l-Phe) (6), cyclo-(l-Val-l-Phe) (7), cyclo-(l-Leu-l-Phe) (8), cyclo-(l-Trp-l-Ile) (9) and cyclo-(l-Trp-l-Phe) (10). The structures of these compounds were established by extensive spectroscopic investigation, as well as by detailed comparison with literature data. This is the first report to discover pyridine, pyrimidine and diketopiperazines from the genus of Pseudogymnoascus. 相似文献
619.
Pei-Liang Zhang Gang Wang Feng-Qing Xu Jin-Song Liu Ju-Tao Wang Rui Zhang 《Natural product research》2019,33(15):2133-2138
A new steroid lactone aspergilolide (1), and nine known compounds helvolic acid (2), verruculogen (3), tryprostatin B (4), 13-oxofumitremorgin B (5), fumitremorgin C (6), demethoxy fumitremorgin C (7), terezine D (8), aszonalenin (9), 12, 13-dihydroxy-fumitremorgin C (10) from cultures of the endophytic fungus Aspergillus sp. MBL1612. Their chemical structures were determined by a series of extensive spectroscopic methods. All of the compounds were isolated from this genus for the first time. The cytotoxicity against five human cancer cell lines of new compound were detected. 相似文献
620.
Production of chitinolytic enzymes with Trichoderma longibrachiatum IMI 92027 in solid substrate fermentation 总被引:1,自引:0,他引:1
Kovacs K Szakacs G Pusztahelyi T Pandey A 《Applied biochemistry and biotechnology》2004,118(1-3):189-204
Thirty Trichoderma strains representing 15 species within the genus were screened for extracellular production of chitinolytic enzymes in solid
substrate fermentation. Trichoderma longibrachiatum IMI 92027 (ATCC 36838) gave the highest yield (5.0 IU/g of dry matter of substrate) after 3 d of fermentation on wheat bran-crude
chitin (9:1 mixture) medium. The optimal moisture content (66.7%), chitin content (20%), initial pH of the medium (2.0–5.0),
and time course (5 d) of solid substrate fermentation were determined for strain IMI 92027. Cellulase, xylanase, α-amylase,
and β-xylosidase activities were also detected. The pH and temperature optima of the chitinase complex of T. longibrachiatum IMI 92027 were 4.5 and 55°C, respectively. The enzyme totally lost its activity at 70°C in 5 min in the absence of the substrate
but retained about 15% of its initial activity even at 70°C after a 60-min incubation in the presence of solid substrate fermentation
solids. Purification of protein extract from the solid substrate fermentation material revealed high chitinolytic activities
between pI 5.9 and 4.8, where N-acetyl-β-d-hexosaminidase and chitinase peaks have been found in the same pI range. Two chitinases of 43.5 and 30 kDa were purified at acidic pI. 相似文献