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排序方式: 共有851条查询结果,搜索用时 593 毫秒
51.
Yokoyama Y Toth B Kitchens WC Schwacha MG Bland KI Chaudry IH 《American journal of physiology. Gastrointestinal and liver physiology》2003,285(6):G1293-G1299
Thromboxane A2 (TXA2) and endothelin-1 (ET-1) have been proposed as the important vasoconstrictors that increase portal venous resistance in paracrine or autocrine fashion. We hypothesized that the hepatic damage following trauma-hemorrhage (T-H) is induced by the impaired hepatic circulation due to the increased production of vasoconstrictors such as ET-1 and TXA2 by the liver. To test this, male Sprague-Dawley rats (n = 6/group) were subjected to trauma (i.e., midline laparotomy) and hemorrhage (35-40 mmHg for 90 min followed by fluid resuscitation) or sham operation. At 2 or 5 h after the end of resuscitation, the liver was isolated and perfused and portal inflow pressure, bile flow, and release of ET-1 and thromboxane B2 (TXB2; a stable metabolite of TXA2) into the perfusate were measured. The level of portal pressure was higher at 5 h following T-H compared with 2 h after T-H and sham. The portal pressure was inversely correlated to the amount of bile production. Furthermore, the bile flow was significantly correlated to the hepatic damage as evidenced by release of lactate dehydrogenase into the perfusate. The level of ET-1 at 5 h following T-H in the perfusate after 30 min of recirculation did not show any difference from sham. However, the levels of TXB2 in the T-H group were significantly higher than those in sham at that interval. These results indicate that the increased release of TXA2 but not ET-1 following T-H might be responsible for producing the increased portal resistance, decreased bile production, and hepatic damage. 相似文献
52.
In the present study, the effect of constituting amino acid residue numbers of oligopeptide derivatives, which are candidate materials to construct molecular recognition sites, on chiral recognition ability was investigated. Chiral recognition sites were formed from oligopeptide derivatives, of which constituting amino acid residue numbers were three to six, by adopting an alternative molecular imprinting. It was made clear that the number four, in other words, the tetrapeptide derivative, is the best candidate material to form a chiral recognition site. 相似文献
53.
Satoru Fukuda Yukihiro Kitade Hiroshi Miyamoto Sawako Nagashima Shuichi Takahashi Toshiharu Ohba Kiyozo Asada Ikunoshin Kato Naotsune Saga 《Journal of applied phycology》2003,15(1):81-86
A gene of Porphyra yezoensis, coding for the translation elongation factor 1 (EF-1), was isolated from a P. yezoensis genomic library. The coding of 1347 nucleotides encodes a polypeptide of 449 amino acids which exhibits sequence similarity as the known EF-1. An intron is located in the 5 untranslated region. Comparison of the deduced amino acid sequence showed higher similarity to the Porphyra purpurea EF-1tef-c (97%) than to the P. purpurea EF-1tef-s (61%). The mRNA was detected both in the leafy gametophyte and filamentous sporophyte by RT-PCR. The nucleotide sequence data reported in this paper will appear in the DDBJ/EMBL/GenBank databases under accession number AB098024. 相似文献
54.
Shimizu K Kondo R Sakai K Shoyama Y Sato H Ueno T 《Bioscience, biotechnology, and biochemistry》2000,64(4):875-877
The acetone extract of Boehmeria nipononivea showed both potent 5alpha-reductase inhibitory activity and hair regrowth promotion effects on mice. 5alpha-Reductase inhibitory activity-guided fractionation led to six active fatty acids: alpha-linolenic, linoleic, palmitic, elaidic, oleic and stearic acids. The extract of B. nipononivea, and alphalinolenic, elaidic and stearic acids exhibited a hair regrowth effect. 相似文献
55.
Flavonoids from Goodyera schlechtendaliana 总被引:1,自引:0,他引:1
A flavonol glycoside, 3-[[6-O-(6-deoxy-alpha-L-mannopyranosyl)-beta-D- glucopyranosyl]oxi]-5,7-dihydroxy-8-[(4-hydroxy-3,5-dimethoxyphenyl)meth yl]- 2-(3,4-dihydroxypheny)-4H-1-benzopyran-4-one, trivially named goodyerin, was isolated from the whole plant of Goodyera schlechtendaliana, along with three known flavonoids, rutin, kaempferol-3-O-rutinoside and isorhamnetin-3-O-rutinoside. The structures were established by spectroscopic analysis. 相似文献
56.
Shin-ichi Morita Sota Takanezawa Michio Hiroshima Toshiyuki Mitsui Yukihiro Ozaki Yasushi Sako 《Biophysical journal》2014,107(10):2221-2229
Cellular differentiation proceeds along complicated pathways, even when it is induced by extracellular signaling molecules. One of the major reasons for this complexity is the highly multidimensional internal dynamics of cells, which sometimes causes apparently stochastic responses in individual cells to extracellular stimuli. Therefore, to understand cell differentiation, it is necessary to monitor the internal dynamics of cells at single-cell resolution. Here, we used a Raman and autofluorescence spectrum analysis of single cells to detect dynamic changes in intracellular molecular components. MCF-7 cells are a human cancer-derived cell line that can be induced to differentiate into mammary-gland-like cells with the addition of heregulin (HRG) to the culture medium. We measured the spectra in the cytoplasm of MCF-7 cells during 12 days of HRG stimulation. The Raman scattering spectrum, which was the major component of the signal, changed with time. A multicomponent analysis of the Raman spectrum revealed that the dynamics of the major components of the intracellular molecules, including proteins and lipids, changed cyclically along the differentiation pathway. The background autofluorescence signals of Raman scattering also provided information about the differentiation process. Using the total information from the Raman and autofluorescence spectra, we were able to visualize the pathway of cell differentiation in the multicomponent phase space. 相似文献
57.
Mugihito Oshiro Katsuhiro Hanada Yukihiro Tashiro Kenji Sonomoto 《Applied microbiology and biotechnology》2010,87(3):1177-1185
In order to achieve high butanol production by Clostridium saccharoperbutylacetonicum N1-4, the effect of lactic acid on acetone–butanol–ethanol fermentation and several fed-batch cultures in which lactic acid
is fed have been investigated. When a medium containing 20 g/l glucose was supplemented with 5 g/l of closely racemic lactic
acid, both the concentration and yield of butanol increased; however, supplementation with more than 10 g/l lactic acid did
not increase the butanol concentration. It was found that when fed a mixture of lactic acid and glucose, the final concentration
of butanol produced by a fed-batch culture was greater than that produced by a batch culture. In addition, a pH-controlled
fed-batch culture resulted in not only acceleration of lactic acid consumption but also a further increase in butanol production.
Finally, we obtained 15.5 g/l butanol at a production rate of 1.76 g/l/h using a fed-batch culture with a pH-stat continuous
lactic acid and glucose feeding method. To confirm whether lactic acid was converted to butanol by the N1-4 strain, we performed
gas chromatography–mass spectroscopy (GC-MS) analysis of butanol produced by a batch culture during fermentation in a medium
containing [1,2,3-13C3] lactic acid as the initial substrate. The results of the GC-MS analysis confirmed the bioconversion of lactic acid to butanol. 相似文献
58.
59.
Kobayashi Y Miyazawa M Kamei A Abe K Kojima T 《Bioscience, biotechnology, and biochemistry》2010,74(12):2385-2395
To determine the effects of mulberry (Morus alba L.) leaves on hyperlipidemia, we performed gene expression profiling of the liver. Rats were fed a high-fat diet and administered mulberry leaves for 7 weeks. Plasma triglyceride and non-esterified fatty acid levels were significantly lower in the rats treated with mulberry leaves as compared with the untreated rats. DNA microarray analysis revealed that mulberry leaves upregulated expression of the genes involved in α-, β- and ω-oxidation of fatty acids, mainly related to the peroxisome proliferator-activated receptor signaling pathway, and downregulated the genes involved in lipogenesis. Furthermore, treatment with mulberry leaves upregulated expression of the genes involved in the response to oxidative stress. These results indicate that consumption of fatty acids and inhibition of lipogenesis are responsible for the reduction in plasma lipids caused by mulberry administration. In addition, mulberry treatment maintains the body's oxidative state at a low level despite enhancing fatty acid oxidation. 相似文献
60.
Nahoko Shikata Yukihiro Maki Masahiko Nakatsui Masato Mori Yasushi Noguchi Shintaro Yoshida Michio Takahashi Nobuo Kondo Masahiro Okamoto 《Amino acids》2010,38(1):179-187
The changes in the concentrations of plasma amino acids do not always follow the flow-based metabolic pathway network. We
have previously shown that there is a control-based network structure among plasma amino acids besides the metabolic pathway
map. Based on this network structure, in this study, we performed dynamic analysis using time-course data of the plasma samples
of rats fed single essential amino acid deficient diet. Using S-system model (conceptual mathematical model represented by
power-law formalism), we inferred the dynamic network structure which reproduces the actual time-courses within the error
allowance of 13.17%. By performing sensitivity analysis, three of the most dominant relations in this network were selected;
the control paths from leucine to valine, from methionine to threonine, and from leucine to isoleucine. This result is in
good agreement with the biological knowledge regarding branched-chain amino acids, and suggests the biological importance
of the effect from methionine to threonine. 相似文献