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31.
M. Fujita T. Kamiya M. Ike Y. Kawagoshi N. Shinohara 《World journal of microbiology & biotechnology》1991,7(3):407-414
Catechol 2,3-oxygenase was produced by Escherichia coli, harbouring the recombinant plasmid pBH100 which contained the pheB gene cloned from phenol-degrading Pseudomonas putida BH, and was applied for the determination of catechol in the liquor. E. coli JM103 (pBH100) and C600 (pBH100) showed, respectively, about 5 and 8.5 times higher activities than that of P. putida BH. Using the crude extract prepared from the culture broth of the recombinant, catechol between 0.1 and 3.0 g/ml could be determined quantitatively in phosphate buffer, synthetic sewage and in mixtures of phenol, benzoate and sallcylate, and also in sodium pyruvate solution. In addition to catechol, 3-methylcatechol, 4-methylcatechol and 4-chlorocatechol could be determined. Oxygenase activity of the crude extract was maintained completely during the 100-day storage at –20°C after being freeze-dried with 10% acelone.M. Fujita, M. Ike, Y. Kawagoshi and N. Shinohara are with the Department of Environmental Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565, Japan. T. Kamiya is with the Central Research Laboratory of Mitsubishi Electric Co., Amagasaki, Hyogo 661, Japan. 相似文献
32.
Summary Using aequorin luminescence, we observed a distinct oscillation in Ca2+ levels in the supernatant of the homogenate ofPhysarum plasmodium. Ca2+ oscillation continued for 10–120 minutes, with a period coinciding with that of the contraction rhythm of a plasmodium.Abbreviations EDTA
Ethylenediaminetetraacetic acid
- EGTA
Ethyleneglycol-bis-(-aminoethylether)-N,N-tetraacetic acid
- PIPES
Piperazine-N,N-bis-(2-ethane sulfonic acid)
- DTT
Dithiothreitol
The present work was supported by Grants-in Aid from the Ministry of Education, Science and Culture, Japan. 相似文献
33.
Summary Using bioluminescence of luciferin-luciferase, we showed that ATP leaked out rhythmically from a strand segment ofPhysarum plasmodium made permeable with caffeine-arsenate. With simultaneous measurement of isometric tension rhythm of the strand, it was revealed that the period and phase of oscillation in ATP leakage correspond well with those of tension production. Further, microinjection of luciferin-luciferase into the plasmodial strand indicated that the intracellular luminescence of luciferin-luciferase also oscillates with the same period and in the same phase as the tension rhythm.The free ATP concentration in a homogenate ofPhysarum plasmodium was of the order of 10 M, but if the homogenate was heated in boiling water, the intensity of luminescence suddenly increased 10–100 fold. ATP available for mechanical workin vivo is thus supposed to be at a much lower level than the total average, which was found in the range of 0.2–0.7 mM. 相似文献
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35.
Schistosoma mansoni: migration potential of normal and radiation attenuated parasites in naive guinea pigs 总被引:2,自引:0,他引:2
Compressed tissue autoradiography using [75Se]selenomethionine labelled parasites has been used to investigate the migration potential of normal and radiation attenuated cercariae of Schistosoma mansoni in naive guinea pigs. By Day 14 after infection. 44% of normal parasites were detected as reduced silver foci in the liver; this value corresponded well with the number of liver parasites recovered by retrograde perfusion of the hepatic portal system on Day 42 (42% of the challenge). In contrast, cercariae subjected to 50 krad of gamma irradiation failed to migrate out of the skin. The migration capacity of 20 krad irradiated parasites was less severely affected in that about half of the challenge parasites reached the lungs, but virtually none moved to the liver. These data are discussed in relation to the kinetics of immunity induced in guinea pigs by infection or vaccination with normal or radiation attenuated parasites. 相似文献
36.
To clarify the transport of O(2) across the microvessels in skeletal muscle, we designed an intravital laser microscope that utilizes a phosphorescence quenching technique to determine both the microvascular and tissue PO(2). After we injected the phosphorescent probe into systemic blood, phosphorescence excited by a N(2)-dye pulse laser was detected with a photomultiplier over a 10 microm in diameter area. In vitro and in vivo calibrations confirmed that the present method is accurate for PO(2) measurements in the range of 7-90 Torr (r = 0.958) and has a rapid response time. This method was then used to measure the PO(2) of microvessels with different diameters (40-130 microm) and of interstitial spaces in rat cremaster muscle. These measurements showed a significant drop in PO(2) in the arterioles after branching (from 74.6 to 46.6 Torr) and the presence of a large PO(2) gradient at the blood-tissue interface of arterioles (15-20 Torr). These findings suggest that capillaries are not the sole source of oxygen supply to surrounding tissue. 相似文献
37.
Ohno F Watanabe J Sekihara H Hirabayashi T Arata S Kikuyama S Shioda S Nakaya K Nakajo S 《Regulatory peptides》2005,126(1-2):115-122
We have found that pituitary adenylate cyclase-activating polypeptide (PACAP) employed at the physiological concentrations induces the differentiation of mouse neural stem cells into astrocytes. The differentiation process was not affected by cAMP analogues such as dibutylic cAMP (db-cAMP) or 8Br-cAMP or by the specific competitive inhibitor of protein kinase A, Rp-adenosine-3',5'-cyclic monophosphothioate triethylamine salt (Rp-cAMP). Expression of the PACAP receptor (PAC1) in neural stem cells was detected by both RT-PCR and immunoblot using an affinity-purified antibody. The PACAP selective antagonist, PACAP(6-38), had an inhibitory effect on the PACAP-induced differentiation of neural stem cells into astrocytes. These results indicate that PACAP acts on the PAC1 receptor on the plasma membrane of mouse neural stem cells, with the signal then transmitted intracellularly via a PAC1-coupled G protein, does not involve Gs. This signaling mechanism may thus play a crucial role in the differentiation of neural stem cells into astrocytes. 相似文献
38.
A raw starch utilizing microbe was isolated from mud in a milling factory. The 16S ribosomal DNA (rDNA) sequencing and morphological properties of the strain indicated that it belongs to the genus Streptomyces. A strongly raw starch digesting amylase was purified from the culture supernatant of the strain by chromatographic procedures. The specific activity of the enzyme was 11.7 U/mg, molecular mass 47 kDa, optimum pH 6.0, and optimum temperature 50 to 60 degrees C. The enzyme showed sufficient activity even at 70 degrees C. It was activated by calcium, cobaltous, and magnesium ions, and inhibited by copper, nickel, zinc, and ferrous ions. It formed maltose mainly from raw and gelatinized starch, and glycogen. No products were formed from glucose, maltose, maltotriose, pullulan, or cyclodextrins (CDs). The enzyme digested raw wheat, rice, and waxy rice starch rapidly, and raw corn, waxy corn, sweet potato, tapioca, and potato starch normally. 相似文献
39.
Takahiro Shibata Fumie Nakashima Kazuya Honda Yu-Jhang Lu Tatsuhiko Kondo Yusuke Ushida Koichi Aizawa Hiroyuki Suganuma Sho Oe Hiroshi Tanaka Takashi Takahashi Koji Uchida 《The Journal of biological chemistry》2014,289(47):32757-32772
Toll-like receptors (TLRs) play a key role in linking pathogen recognition with the induction of innate immunity. They have been implicated in the pathogenesis of chronic inflammatory diseases, representing potential targets for prevention/treatment. Vegetable-rich diets are associated with the reduced risk of several inflammatory disorders. In the present study, based on an extensive screening of vegetable extracts for TLR-inhibiting activity in HEK293 cells co-expressing TLR with the NF-κB reporter gene, we found cabbage and onion extracts to be the richest sources of a TLR signaling inhibitor. To identify the active substances, we performed activity-guiding separation of the principal inhibitors and identified 3-methylsulfinylpropyl isothiocyanate (iberin) from the cabbage and quercetin and quercetin 4′-O-β-glucoside from the onion, among which iberin showed the most potent inhibitory effect. It was revealed that iberin specifically acted on the dimerization step of TLRs in the TLR signaling pathway. To gain insight into the inhibitory mechanism of TLR dimerization, we developed a novel probe combining an isothiocyanate-reactive group and an alkyne functionality for click chemistry and detected the probe bound to the TLRs in living cells, suggesting that iberin disrupts dimerization of the TLRs via covalent binding. Furthermore, we designed a variety of iberin analogues and found that the inhibition potency was influenced by the oxidation state of the sulfur. Modeling studies of the iberin analogues showed that the oxidation state of sulfur might influence the global shape of the isothiocyanates. These findings establish the TLR dimerization step as a target of food-derived anti-inflammatory compounds. 相似文献
40.