全文获取类型
收费全文 | 1324篇 |
免费 | 79篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 27篇 |
2020年 | 11篇 |
2019年 | 18篇 |
2018年 | 42篇 |
2017年 | 41篇 |
2016年 | 40篇 |
2015年 | 65篇 |
2014年 | 64篇 |
2013年 | 72篇 |
2012年 | 103篇 |
2011年 | 104篇 |
2010年 | 67篇 |
2009年 | 46篇 |
2008年 | 90篇 |
2007年 | 91篇 |
2006年 | 79篇 |
2005年 | 62篇 |
2004年 | 68篇 |
2003年 | 50篇 |
2002年 | 57篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 8篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1993年 | 13篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 13篇 |
1989年 | 14篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 13篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1977年 | 2篇 |
1975年 | 7篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1403条查询结果,搜索用时 46 毫秒
1.
R Takeda I Miyamori R Soma T Matsubara M Ikeda 《Journal of steroid biochemistry》1987,27(4-6):845-849
Mineralocorticoid activity of glycyrrhetinic acid (GR) was studied in vivo (electrical potential difference in rat rectum) and in vitro (brush border Mg2+-HCO3- ATPase in rat small intestine, kidney cytosol binding of GR with and without RU-28362, anti-glucocorticoid compound) in order to clarify the mechanism of mineralocorticoid-like activity of GR. Scatchard analysis of [3H]aldosterone showed that Kd of higher affinity site (type I) 6.0 X 10(-9) M, Bmax 1.0 X 10(-14) mol/mg protein, and Kd of lower affinity site (type II) 1.6 X 10(-7) M, Bmax 7.5 X 10(-14) mol/mg protein. GR competed for [3H]aldosterone binding sites in kidney cytosol at the concentration of 10(4) times as that of unlabeled aldosterone. RU-28362 displaced aldosterone binding curve, whereas GR binding kinetic was not affected by this compound. Adrenalectomy caused a significant fall in brush border Mg2+-HCO3- ATPase activity (75% reduction compared with the initial level) which was not restored by GR administration. Electrical potential differences in the adrenalecomized rats were significantly lower than those in the control rats, which did not increase after GR administration. 相似文献
2.
Mesophyll protoplasts from leaves of aseptically grown shoot tips of Diplotaxis muralis were isolated (6.2–7.1×105 protoplasts/g fresh weight of tissue) using one step enzyme digestion. The protoplasts (71% viability) underwent divisions (4.2+0.1%) on plating in M8PS2 medium and ultimately formed calli with 0.45+0.03% plating efficiency. Plant regeneration could be achieved both through embryogenesis and organogenesis. The efficiency of plant regeneration through organogenesis was 9 times higher than embryogenesis. Forty eight out of 52 plants regenerated so far from 3 independent experiments were normal with respect to fertility and meiotic chromosomal behavior.Abbreviations BAP
6-benzylaminopurine
- GA3
Gibberellic acid
- A
Kao and Michayluk, 1981
- KM
Kao and Michayluk, 1975
- MK3
Modified K3
- M8P
Modified 8P
- MS
Murashige and Skoog, 1962
- NAA
1-naphthalene acetic acid
- PE
Plating efficiency 相似文献
3.
Kaijiro Anzai Shunsuke Kobayashi Narumi Kitamura Yuri Kanai Hiromichi Nakajima Yoshioki Suehiro Sataro Goto 《Journal of neurochemistry》1986,47(3):673-677
We isolated a mouse genomic clone that hybridized with small RNA present in the cytoplasm of the brain. The RNA was about 150 nucleotides long. This RNA seemed to be specific to the brain, since it was not found in the liver or kidney. The clone DNA contained a sequence homologous to 82-nucleotide "identifier" core sequence of cDNA clones of rat. The sequence contained a split promoter for RNA polymerase III and was flanked by a 12-nucleotide direct repeat (ATAAATAATTTA). 相似文献
4.
Structural analysis of a developmentally regulated 25-kDa protein gene of Sarcophaga peregrina 总被引:3,自引:0,他引:3
N Matsumoto K Sekimizu G Soma Y Ohmura T Andoh Y Nakanishi M Obinata S Natori 《Journal of biochemistry》1985,97(5):1501-1508
In the previous paper, we described the identification of two abundant mRNAs of Sarcophaga peregrina (flesh-fly) which are selectively expressed in the fat body of middle third instar larvae. One of these mRNAs was found to encode a protein with a molecular mass of about 25,000 (25-kDa protein) when translated in vitro (Tamura, H., et al. (1983) Dev. Biol. 99, 145-151). Present paper reports the nucleotide sequence of a 2.3 kb DNA containing the entire gene for the 25-kDa protein. This gene consisted of four exons and contained an open reading frame for 184 amino acids. A CAT box and a TATA box were found in the 5'-flanking sequence. A poly A addition signal of AATAAA was assigned to the non-coding region in the fourth exon. A sequence having 75% homology with SV40 enhancer core sequence was identified in the non-coding region of the first exon. 相似文献
5.
A radioimmunoassay for progesterone was developed which uses one micro-column chromatography for purification of hexane extracts of plasma. 相似文献
6.
I Ono I Ishiwata T Nakaguchi M Soma N Tokita C Ishiwata M Mukai S Nozawa H Ishikawa 《Human cell》1989,2(3):272-277
The malignant schwannoma cell line (HKMS) was established from the subcutaneous tumor of Axilla region of a 48-year-old Japanese woman. The HKMS line has the following biological properties. 1. The HKMS cells were spindle in shape and showed neoplastic and pleomorphic features. The monolayer sheet of HKMS cells showed the resemble cell-arrangement with that of the original tumor tissue. 2. The cells showed a stable growth and the serial passages were successively carried out 150 times within 3 years. Their population doubling time is about 40 hours. 3. The chromosome number varied widely, and the modal number was stable at the 78-80. The marker chromosomes were present. 4. The cells were transplanted into the subcutis of nude mice and produced the malignant schwannoma. 相似文献
7.
I Ono I Ishiwata T Nakaguchi K Ohara N Tokita M Soma C Ishiwata S Nozawa H Ishikawa 《Human cell》1989,2(4):416-422
We cultured an aspiration fluid of the sternal bone marrow of the patient having adrenal neuroblastoma and established a neuroblastoma cell line (HSNB). The HSNB line has the following biological properties. 1. They are small round in shape and proliferate in flotation while forming cell aggregate, and often they attach the bottom of plastic dish and process the nerve-like fibers. A rough-endoplasmic reticulum are poorly developed, however, a lot of free ribosomes are scattered in the cytoplasm. In the peripheral area of the cells, small spherical secretory granules (60-140 nm in diameter) are existed. One characteristic of this cell is existence of microtubules in the cell-projections. 2. They show a stable growth and the doubling time is about 50 hours. 3. Their chromosome number varied widely and the mode is 46. The double minute chromosomes were present in 50% of cells. 4. When they are transplanted in the cheek pouch of hamster, they produced the neuroblastoma. 5. They produce neuron specific enolase. 6. N-myc gene was amplified ca 250 folds. 相似文献
8.
M R Soma J D Morrisett A M Gotto D S Loose-Mitchell J A Poorman S A Smith M L Overturf 《Journal of lipid research》1990,31(6):985-994
We have previously described a colony of New Zealand White rabbits that are resistant to hypercholesterolemia when fed a cholesterol-enriched diet. The present studies used skin fibroblasts obtained from normal and hypercholesterolemia-resistant rabbits to investigate cholesterol metabolism and lipid composition in vitro. The lipid compositions of the two cell lines after incubation in either fetal calf serum or lipoprotein-deficient serum were similar. The conversion of radiolabeled acetate into sterol and phospholipids was higher in resistant fibroblasts than in normal fibroblasts. In contrast, incorporation of radiolabeled oleic acid into cholesteryl ester was significantly lower in resistant fibroblasts than in normal cells. In parallel experiments, the 3-hydroxy-3-methylglutaryl coenzyme A reductase activity was higher and acyl-coenzyme A:cholesterol acyltransferase activity was lower in resistant cells compared to normal cells. Furthermore, binding, uptake, and degradation of normal rabbit 125I-labeled LDL (low density lipoproteins) were 30% higher in resistant than in normal fibroblasts. These observations are consistent with results from previous studies of cholesterol metabolism in the liver membranes of these rabbits. The results indicate that extrahepatic cells (such as fibroblasts) from the resistant rabbit exhibit the same altered cholesterol metabolism as that found in the hepatic tissues of these rabbits. These studies suggest that the resistant rabbit may provide an in vivo and in vitro system for studying the mechanisms by which some individuals of a species can minimize the effect of dietary cholesterol on the development of hypercholesterolemia and atherosclerosis. 相似文献
9.
The distribution density of opioid receptors in the brain of El mice (seizure-susceptible strain) was examined to determine the relation between seizures and the opioid system. Saturation curves and Scatchard plots of [3H]2-d-alamine-5-d-leucine enkephalin binding revealed that the opioid delta receptor density in adult El mice during interictal periods was significantly increased in the cerebral cortex, hippocampus, and septal area. It was further shown that the concentration of such receptors in 25-day-old El mice that had no seizures was also significantly increased in the hippocampus and septal area, with no changes in apparent affinities, as compared with in the corresponding regions in ddY mice (seizure-nonsusceptible strain; the mother strain of El). Such up-regulation of opioid receptors in the El mouse brain could result from deficits in endogenous opioid peptides, which could be associated with the pathogenesis of seizure diathesis in the El mouse. 相似文献
10.
Shigenori Goto Sumitaka Sakai Jiro Kera Yukie Suma Gen-Ichiro Soma Shoshichi Takeuchi 《Cancer immunology, immunotherapy : CII》1996,42(4):255-261
Lipopolysaccharide (LPS) has been recognized as a potent antitumor agent in animal tumor models; however, its use in human
cancer therapy has been limited to only one trial, in which LPS from Salmonella was given intravenously. It was not very successful because of poor tumor response and was also toxic. We originally developed
LPS prepared from Pantoea agglomerans (LPSp), and this was a well-purified, small-molecular-mass (5 kDa) agent. We chose intradermal rather than intravenous administration
in the hope that the former would release LPS slowly into the bloodstream, and thus be less toxic while preserving antitumor
activity. In our animal tumor models, intradermal administration was indeed less toxic and more beneficial for tumor regression
than intravenous administration. We made a pilot study with intradermal administration of LPSp on the treatment of ten advanced
cancer patients. Five of them had evaluable tumor, which had failed earlier to respond to conventional chemotherapy. Cyclophosphamide
was also administered in this trial, in anticipation of its synergistic effect with LPSp. In this study LPSp was injected
intradermally into each patient twice a week, starting with an initial dose of 0.4 ng/kg, and raising it to 600 or 1800 ng/kg.
A 400-mg/m2 dose of cyclophosphamide was given intravenously every 2 weeks. After completion of the dose escalation, the treatment was
continued for at least 4 months, and it was found that 1800 ng/kg LPSp was well tolerated. A significant level of cytokines
was observed in the sera for at least 8 h. These results indicate higher tolerable doses and remarkably more continuous induction
of the cytokines than were reported in a previous study by others using intravenous administration. Three of the five evaluable
tumors showed a significant response to our combined therapy. Intradermally administered, LPS was less toxic and elicited
a tumor response in combination with cyclophosphamide; it can thus can be applied to cancer treatment even in humans.
Received: 3 August 1995 / Accepted: 2 April 1996 相似文献