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31.
Tetsuya Tanigawa Yasuo Mizo-oku Kouichi Moriguchi Takashi Suzuki Takahiko Osumi Masaaki Odomi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,683(2):135
A simple and rapid quantitative method for 13C-labelled urea ([13C]urea) in human serum was developed by using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS). This method is used to establish and normalize the [13C]urea breath test, which is considered as an effective diagnostic method for Helicobacter pylori infection. HPLC-APCI-MS, involving a simple pretreatment process such as diluting serum with water, was shown to be able to discriminate the extrinsic [13C]urea from intrinsic urea present at high concentration in serum. In addition, a 13C nuclear magnetic resonance spectroscopic quantitative method for [13C]urea in human urine is also described. The precision and accuracy of measured concentrations in these two methods were found to be within the acceptable limit. An application of these methods to investigate the pharmacokinetic profile of orally administered [13C]urea in human serum and urine is also presented. 相似文献
32.
Yoichi Honda Toshikazu Irie Mina Atsuji Takashi Watanabe Masaaki Kuwahara 《Mycoscience》1996,37(4):459-461
To develop a dominant genetic marker inPleurotus ostreatus, mutant strains resistant to a carboxin-derived fungicide, flutolanil, were isolated. These mutants included strains which
showed resistance to 50-fold higher concentration of fluotolanil than the wild-type strain, even after successive cultivations
in the absence of the drug. Dominance of the phenotype was confirmed by back-crossing between the resistant and wild-type
monokaryons. The flutolanilresistance was also shown to be stably inherited by the basidiospore-derived progenies of the mutant
strains. 相似文献
33.
Shinichi Yoshida Saori Yonehara Shigemi Minami Hyo-cheol Ha Kenji Iwahara Takashi Watanabe Yoichi Honda Masaaki Kuwahara 《Mycoscience》1996,37(4):417-425
Manganese peroxidase (MnP) and lignin peroxidase (LiP) were produced by growing a white-rot fungusBjerkandera adusta statically, on a wood meal/wheat bran culture in flasks. MnP and LiP reached their maximum activity after 6 and 19 days of
inoculation, respectively. Both MnP and LiP are thought to be important enzymes in lignin biodegradation byB. adusta. Ion exchange chromatography showed thatB. adusta produced a single LiP and a single MnP enzyme in wood meal/wheat bran culture. These enzymes were separated and characterized.
The molecular weight of MnP was 46,500 with a pl of 3.9. The molecular weight of LiP was estimated to be 47,000 with a pl of 3.5. Spectral analysis demonstrated that both enzymes are heme proteins. Production of these enzymes was also achieved
using a rotarysolid culture fermenter. MnP, LiP and veratryl alcohol oxidase were produced byB. adusta in the fermenter. 相似文献
34.
Jinyuan Liu Chikage Hara Masaaki Umeda Yuan Zhao Thomas W. Okita Hirofumi Uchimiya 《Plant molecular biology》1995,29(4):685-689
Using a cDNA library prepared from poly(A)+ RNA from 10-day-old rice endosperm, partial nucleotide sequences of randomly isolated clones were analyzed. A total of 153 (30.6%) out of 500 cDNA clones showed high amino acid identity to previously identified genes. There was significant redundancy in cDNAs encoding prolamine and glutelin. About 21.0% of the cDNA clones were found to code for seed storage protein genes. Consequently, 37 independent genes were identified. Using cDNA clones encoding glutelin, prolamine, seed allergen, -1,4-glucan branching enzyme, glycine-rich RNA binding protein, metallothionein, non-specific lipid-transfer protein and ubiquitin conjugating enzyme the accumulation of mRNA during rice seed development was compared. Genes associated with seed storage protein and starch biosynthesis were expressed according to expected developmental stages. Glycinerich RNA binding protein genes as well as metallothionein-like protein genes were highly expressed in developing seeds, but low in leaves of whole plants. 相似文献
35.
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37.
Masaaki Satoh Hiroichi Asagami Dongchon Kang Shigeki Minakami Koichiro Takeshige 《Molecular and cellular biochemistry》1995,152(2):159-165
A chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (fMLP), induced an acidification of cytosol by about 0.05 pH units in 30 sec followed by an alkalinization in human neutrophils. The quantitative contribution of acid production to the acidification was studied. The superoxide (O2
–) production stimulated by fMLP was not involved in the acidification because the production of acids in neutrophils from patients with chronic granulomatous disease who do not produce O2
–, was the same as that in normal neutrophils. The intracellular acidification was completely inhibited by deoxyglucose, suggesting that energy metabolism enhanced upon stimulation by fMLP might be the main source of the acidification. Although enhancement of the lactate formation by fMLP was 0.8 nmol/106 cells, which could lower intracellular pH by 0.08 pH units, the lactate production could not explain the initial acidification because the production of lactate started at 1 min after the stimulation while the intracellular acidification began immediately after the stimulation. Mitochondrial respiratory inhibitors such as KCN and rotenone had no effects on the fMLP-induced intracellular acidification. The fMLP-induced production of CO2 in 30 sec through the hexose monophosphate shunt was only 2.6 pmol/106 cells, which was calculated to decrease intracellular pH by only 0.0014. Thus, changes of energy metabolism induced by fMLP does not explain the acidification.Abbreviations fMLP
N-formyl-methionyl-leucyl-phenylalanine
- BCECF-AM
2,7-bis(carboxyethyl)carboxyfluorescein acetoxymethyl ester
- PMA
phorbol 12-myristate 13-acetate
- CGD
chronic granulomatous disease
- HMP
hexose monophosphate
- pHi
intracellular pH 相似文献
38.
39.
Phylogeny of symbiotic methanogens in the gut of the termite Reticulitermes speratus 总被引:3,自引:0,他引:3
Abstract The phylogeny of a symbiotic methanogen inhabiting the gut of a lower termite, Reticulitermes speratus , was analysed without cultivation. The small subunit ribosomal RNA gene (ssrDNA) and a 640-bp portion of the gene encoding subunit A of methyl coenzyme M reductase ( mcrA ) were amplified from a mixed-population DNA of the termite gut by polymerase chain reaction and cloned. The nucleotide sequence of the ssrDNA and the predicted amino acid sequence of the mcrA product were compared with those of the known methanogens. Both comparisons indicated that the termite symbiotic methanogen belonged to the order Methanobacteriales but was distinct from the known members of this order. 相似文献
40.
Identification by in vitro complementation of regions required for cell-invasive activity of Bordetella pertussis adenylate cyclase toxin 总被引:2,自引:0,他引:2
The adenylate cyclase toxin (CyaA) of Bordetella pertussis is a 1706-residue protein composed of an amino-terminal adenylate cyclase (AC) domain linked to a 1300-residue channel-forming RTX ( r epeats in t o x in) haemolysin. The toxin delivers its AC domain into a variety of eukaryotic cells and impairs cellular functions by catalysing unregulated synthesis of cAMP from intracellular ATP. We have examined toxin activities of a set of deletion derivatives of CyaA. The results indicate that CyaA does not have a dedicated target cell-binding domain and that structural integrity and co-operation of all domains, as well as the post-translational fatty acylation mediated by an accessory protein CyaC, are all essential for target cell association and toxin activity of CyaA. When tested individually, all toxin derivatives were inactive and impaired in the tight association with the target cell surface. However, pairs of constructs with non-overlapping deletions complemented each other in vitro and exhibited a partially restored cytotoxic activity. This suggests that at least a part of the active toxin may act in the form of dimers or higher oligomers. The complementation analysis revealed that the last 217 residues of CyaA, containing the unprocessed secretion signal, form an autonomous domain essential for toxin activity, and that the region from residue 624 to 780 may be directly involved in delivery of the AC toxin into cells. 相似文献