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排序方式: 共有147条查询结果,搜索用时 15 毫秒
61.
Association of a -1997G-->T polymorphism of the collagen Ialpha1 gene with bone mineral density in postmenopausal Japanese women 总被引:1,自引:0,他引:1
Yamada Y Ando F Niino N Shimokata H 《Human biology; an international record of research》2005,77(1):27-36
Genetic variants that affect collagen Ialpha1 metabolism may be important in the development of osteoporosis or osteoporotic fractures. A -1997G-->T polymorphism in the promoter of the collagen Ialpha1 gene (COL1A1) was shown to be associated with bone mineral density (BMD) for the lumbar spine in postmenopausal Spanish women. The relation of this polymorphism to BMD in Japanese women or men has now been examined in a population-based study. The subjects (1,110 women, 1,126 men) were 40 to 79 years of age and were randomly recruited for a population-based prospective cohort study of aging and age-related diseases. BMD for the lumbar spine, right femoral neck, right trochanter, and right Ward's triangle was measured using dual-energy x-ray absorptiometry. Genotypes for the -1997G-->T polymorphism of COL1A1 were determined with a fluorescence-based allele-specific DNA primer assay system. When all women were analyzed together, BMD for the lumbar spine and trochanter was significantly lower in subjects with the COL1A1 *G/*G genotype than in those in the combined group of COL1A1 *G/*T and COL1A1 *T/*T genotypes. When postmenopausal women were analyzed separately, BMD for the femoral neck and trochanter was also significantly lower in those with the COL1A1 *G/*G genotype than in those with the COL1A1 *G/*T genotype or those in the combined group of COL1A1*G/*T and COL1A1 *T/*T genotypes. BMD was not associated with -1997G-->T genotype in premenopausal women or in men. Multivariate regression analysis revealed that -1997G-->T genotype affected BMD at various sites with a variance of 0.46-0.62% for all women and 0.61-1.01% for postmenopausal women. The -1997G-->T genotype was not related to the serum concentration of osteocalcin, the serum activity of bone-specific alkaline phosphatase, or the urinary excretion of deoxypyridinoline or cross-linked N-telopeptides of type I collagen in men or in premenopausal or postmenopausal women. These results suggest that COL1A1 is a susceptibility locus for reduced BMD in postmenopausal Japanese women. 相似文献
62.
Alzheimer's beta-secretase (BACE1) is a membrane-bound protease that cleaves the amyloid precursor protein (APP) in the trans-Golgi network, an initial step in the pathogenesis of Alzheimer's disease. Although BACE1 is distributed among various tissues including brain, its physiological substrate other than APP have not been identified. We have recently found that when BACE1 was overexpressed in COS cells together with alpha2,6-sialyltransferase (ST6Gal I), the secretion of ST6Gal I markedly increased, suggesting that BACE1 cleaves ST6Gal I as a physiological substrate. Thus BACE1 is the first identified protease that is responsible for the cleavage and secretion of glycosyltransferases. 相似文献
63.
Alzheimer's beta-secretase (BACE1) cleaves amyloid precursor protein to produce amyloid beta-peptide, which is a crucial initiation process of the pathogenesis of Alzheimer's disease. We previously found that BACE1 also cleaves a membrane-bound sialyltransferase (ST6Gal I). Here we report that, when the protein A-ST6Gal I fusion protein, or ST6Gal I-derived peptide, was used as an in vitro substrate for BACE1, it cleaved the substrates between Leu(37) and Gln(38). However, a soluble form of ST6Gal I secreted from COS cells started from Glu(41), which was three amino acids shorter than the in vitro product. The results suggested that the BACE1 product was truncated by an aminopeptidase(s) before secretion. The aminopeptidase activity was successfully detected in detergent extracts of Golgi-membrane fraction. Taken together, we concluded that BACE1 initially cleaved ST6Gal I between Leu(37) and Gln(38), and the NH(2)-terminal three amino acids of the yielded product was further trimmed by the aminopeptidase. 相似文献
64.
Takeshi Ijuin Ken Kitajima Yu Song Shinobu Kitazume Sadako Inoue Stuart M. Haslam Howard R. Morris Anne Dell Yasuo Inoue 《Glycoconjugate journal》1996,13(3):401-413
Novel sulfated and nonsulfated oligosialyglycosphingolipids were isolated from sperm of the sea urchin,Hemicentrotus pulcherrimus, and their structures were established as follows: ±HSO3Neu5Ac2(8Neu5Ac2)n6G1c11´Cer, wheren=0, 1, 2, 3. This provides the first evidence for the natural occurrence of a tetrasialic acid structure in glycosphingolipids. The finding of sulfated oligosialyl chains is especially noteworthy in that the sulfate group exclusively resides on the C-8 of the nonreducing terminal residues of oligo/polysialyl chains and that sulfation appears to be a termination signal for elongation of oligosialyl chains. Sulfation at the nonreducing terminal Neu5Ac residues of oligosialyl chains was also found to facilitate the formation of an inter-residue lactone between the carboxyl group at the nonreducing terminal sulfated Neu5Ac and the hydroxyl group at C-9 of the penultimate Neu5Ac residue. The long chain base was 4-hydroxysphinganine (t18:0) and the major fatty acid species were identified as C20:1, C21:1, and C22:1.Abbreviations C:M
chloroform:methanol
- FAB-MS
fast atom bombardment mass spectrometry
- GLC
gas-liquid chromatography
- GSL
glycosphingolipid
- HPTLC
high performance thin-layer chromatography
- Neu5Ac8HSO3 or HSO3 Neu5Ac
5-N-acetyl-8-O-sulforylneuraminic acid
- Neu5Gc9HSO3
5-N-glycolyl-9-O-sulforylneuraminic acid
- NMR
nuclear magnetic resonance
- PB
sodium phosphate buffer, pH 7.2
- Sia
sialic acid
- HSO3 Sia
sulfated sialic acid
- polySia
polysialic acid
- TFA
trifluoroacetic acid
Since the dividing line between oligo- and polysialic acids is not rigidly defined, we propose here that those containing more than penta-sialic acid chains can be referred to as the polysialic acid group. The rationale for this is that 2 8-linked pentasialic acid is the minimum chain length to exhibit the conformational property of polysialic acid [of Michon, F, Brisson, J-R, Jennings, H (1987)Biochemistry
26: 8399–405] and to act as a substrate for the endosialidase, Endo-N [Hallenbeck, PC, Vimr, ER, Yu, F, Bassler, B, Troy, FA (1987)J Biol Chem
262: 3553–61]. 相似文献
65.
Cytoplasm and cell sap of Lamprothamnium succinctum were analyzedseparately for the contents of free amino acids and sucroseto find whether they contribute to turgor regulation. In thevacuole, both amino acids and sucrose were found to be minorcomponents contributing to the generation of osmotic pressure.Their amounts were almost insensitive to changes in externalosmotic pressure. In the cytoplasm, both amino acids and sucrosein the cytoplasm contributed about 20% to the osmotic pressure.Hypotonic treatment did not affect the contents of either, buthypertonic treatment, while not affecting the amino acid contents,caused a significant increase in sucrose content. The cytoplasmicsucrose content increased linearly with an increase in externalosmotic pressure, accounting for 40% of the increased osmoticpressure.
1 Present address: Department of Biology, Osaka Medical College,Sawaragi-cho, Takatsuki, Osaka 569, Japan
2 Present address: Department of Applied Physiology, NationalInstitute of Agrobiological Resources, Yatabe, Tsukuda, Ibaragi305, Japan (Received November 25, 1986; Accepted March 18, 1987) 相似文献
66.
Summary In internodal cells ofLamprothamnium succinctum, turgor regulation in response to hypotonie treatment is inhibited by lowering external Ca2+ concentration ([Ca2+]e) from 3.9 (normal) to 0.01 (low) mM. In order to clarify whether a change in the cytoplasmic free Ca2+ concentration ([Ca2+]c) is involved in turgor regulation, the Ca2+ sensitive protein aequorin was injected into the cytoplasm of internodal cells. A large transient light emission was observed upon hypotonic treatment under normal [Ca2+]e but not under low [Ca2+]e. Thus hypotonic treatment induces a transient increase in [Ca2+]c under normal [Ca2+]e but not under low [Ca2+]e.Abbreviations ASW
artificial sea water
- i
cellular osmotic pressure
- [Ca2+]c
cytoplasmic free Ca2+ concentration
- EDTA
ethylenediamine-tetraacetic acid
- EGTA
ethylenglycol-bis(-aminoethyl ether(N,N-tetraacetic acid
- [Ca2+]e
external Ca2+ concentration
- e
external osmotic pressure
- GM
glass micropipette
- GP
glass plate
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethansulfonic acid
- MS
microscope stage
- OL
objective lens
- PIPES
piperazine-N-N-bis(2-ethanesulfonic acid)
- W
Weight 相似文献
67.
Tanaka Osamu; Nagase Hiroko; Kitazume Yumi; Mizoguchi Fumie; Izawa Kyoko 《Plant & cell physiology》1988,29(8):1379-1384
Lemna paucicostata 441, a short-day plant, flowered even undercontinuous light in nitrogen-deficient, half-strength Hutnersmedium, when the endogenous level of nitrogen was decreasedto 1.4µg/mg fr wt or lower, but no flowering occurredin nitrogen-deficient, modified Hoagland medium when the endogenouslevel of nitrogen was similarly reduced. The failure to flowerin this medium can be ascribed to the presence of high concentrationsof calcium, the absence of EDTA, and low pH. Daylength-independent flowering induced by nitrogen deficiencywas greatly enhanced by the addition to the growth medium ofmicronutrients and EDTA at high concentrations. Among the micronutrients,zinc seemed to be the most important. (Received May 30, 1988; Accepted September 22, 1988) 相似文献
68.
Yoichi Matsuda Izuo Tobari Junji Yamagiwa Toyoko Utsugi Masayuki Kitazume Sayaka Nakai 《Mutation research》1984,129(3):373-380
The yield of translocations induced by γ-rays in the crab-eating monkey (Macaca fascicularis) spermatogonia were studied by cytological analysis in spermatocytes derived from them. The frequencies of translocations were 0.09% at 0 Gy, 1.9% at 1 Gy, 2.5% at 2 Gy and 1.3% at 3 Gy, showing a humped dose-response curve with a peak yield around 2 Gy. No remarkable inter-seasonal or inter-animal variations in the induction of translocation were observed. The frequencies in the crab-eating monkey were significantly higher than those in the same Macaca genus, the rhesus monkey (Macaca mulatta) (van Buul, 1976, 1980). This inter-species difference in radiosensitivity might be affected by the condition of spermatogonial stem cells at the time of exposure to radiation, depending on the seasonal change in spermatogenetic activity. 相似文献
69.
Etsuko Iio Kentaro Matsuura Nao Nishida Shinya Maekawa Nobuyuki Enomoto Mina Nakagawa Naoya Sakamoto Hiroshi Yatsuhashi Masayuki Kurosaki Namiki Izumi Yoichi Hiasa Naohiko Masaki Tatsuya Ide Keisuke Hino Akihiro Tamori Masao Honda Shuichi Kaneko Satoshi Mochida Hideyuki Nomura Shuhei Nishiguchi Chiaki Okuse Yoshito Itoh Hitoshi Yoshiji Isao Sakaida Kazuhide Yamamoto Hisayoshi Watanabe Shuhei Hige Akihiro Matsumoto Eiji Tanaka Katsushi Tokunaga Yasuhito Tanaka 《Human genetics》2015,134(3):279-289
70.
Hiroyuki Ogawa Kosuke Kaji Norihisa Nishimura Hirotetsu Takagi Koji Ishida Hiroaki Takaya Hideto Kawaratani Kei Moriya Tadashi Namisaki Takemi Akahane Hitoshi Yoshiji 《Journal of cellular and molecular medicine》2021,25(8):4001-4013
Molecular targeted agents are pharmacologically used to treat liver fibrosis and have gained increased attention. The present study examined the preventive effect of lenvatinib on experimental liver fibrosis and sinusoidal capillarization as well as the in vitro phenotypes of hepatic stellate cells. LX-2, a human stellate cell line, was used for in vitro studies. In vivo liver fibrosis was induced in F344 rats using carbon tetrachloride by intraperitoneal injection for 8 weeks, and oral administration of lenvatinib was started two weeks after initial injection of carbon tetrachloride. Lenvatinib restrained proliferation and promoted apoptosis of LX-2 with suppressed phosphorylation of extracellular signal-regulated kinase 1/2 and AKT. It also down-regulated COL1A1, ACTA2 and TGFB1 expressions by inhibiting the transforming growth factor-β1/Smad2/3 pathway. Treatment with lenvatinib also suppressed platelet-derived growth factor-BB-stimulated proliferation, chemotaxis and vascular endothelial growth factor-A production, as well as basic fibroblast growth factor-induced LX-2 proliferation. In vivo study showed that lenvatinib attenuated liver fibrosis development with reduction in activated hepatic stellate cells and mRNA expression of profibrogenic markers. Intrahepatic neovascularization was ameliorated with reduced hepatic expressions of Vegf1, Vegf2 and Vegfa in lenvatinib-treated rats. Collectively, these results suggest the potential use of lenvatinib as a novel therapeutic strategy for liver fibrosis. 相似文献