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排序方式: 共有324条查询结果,搜索用时 15 毫秒
81.
Luong Cong Thuc Yasushi Teshima Naohiko Takahashi Yasuko Nagano-Torigoe Kaori Ezaki Kunio Yufu Mikiko Nakagawa Masahide Hara Tetsunori Saikawa 《Apoptosis : an international journal on programmed cell death》2010,15(6):669-678
Reactive oxygen species (ROS) are important intracellular signaling molecules and are implicated in cardioprotective pathways
including ischemic preconditioning. Statins have been shown to have cardioprotective effects against ischemia/reperfusion
injury, however, the precise mechanisms remain to be elucidated. We hypothesized that ROS-mediated signaling cascade may be
involved in pravastatin-induced cardioprotection. Cultured rat cardiomyocytes were exposed to H2O2 for 30 min to induce cell injury. Pravastatin significantly suppressed H2O2-induced cell death evaluated by propidium iodide staining and the MTT assay. Incubation with pravastatin activated catalase,
and prevented a ROS burst induced by H2O2, which preserved mitochondrial membrane potential. Protective effects were induced very rapidly within 10 min, which was
concordant with the up-regulation of phosphorylated ERK1/2. L-NAME, 5HD, N-acetylcysteine (NAC) and staurosporine inhibited ERK1/2 phosphorylation and also reduced pravastatin-induced cardioprotection,
suggesting NO, mitochondrial KATP (mitoKATP) channels, ROS and PKC should be involved in the cardioprotective signaling. We also demonstrated that pravastatin moderately
up-regulated ROS generation in a 5HD-inhibitable manner. In isolated perfused rat heart experiments, pravastatin administered
10 min prior to no-flow global ischemia significantly improved left ventricular functional recovery, and also reduced infarct
size, which were attenuated by the treatment with NAC, 5HD, L-NAME or staurosporine. Administration of pravastatin from the
beginning of reperfusion also conferred cardioprotection. Pravastatin protected the cardiomyocytes against oxidative stress
by preventing the ROS burst and preserving mitochondrial function. Moderately up-regulated ROS production by mitoKATP channels opening is involved in the pro-survival signaling cascade activated by pravastatin. 相似文献
82.
Koji Isodono Tomosaburo Takahashi Hiroko Imoto Naohiko Nakanishi Takehiro Ogata Satoshi Asada Atsuo Adachi Tomomi Ueyama Hidemasa Oh Hiroaki Matsubara 《PloS one》2010,5(3)
To identify novel transmembrane and secretory molecules expressed in cardiac myocytes, signal sequence trap screening was performed in rat neonatal cardiac myocytes. One of the molecules identified was a transmembrane protein, prostatic androgen repressed message-1 (PARM-1). While PARM-1 has been identified as a gene induced in prostate in response to castration, its function is largely unknown. Our expression analysis revealed that PARM-1 was specifically expressed in hearts and skeletal muscles, and in the heart, cardiac myocytes, but not non-myocytes expressed PARM-1. Immunofluorescent staining showed that PARM-1 was predominantly localized in endoplasmic reticulum (ER). In Dahl salt-sensitive rats, high-salt diet resulted in hypertension, cardiac hypertrophy and subsequent heart failure, and significantly stimulated PARM-1 expression in the hearts, with a concomitant increase in ER stress markers such as GRP78 and CHOP. In cultured cardiac myocytes, PARM-1 expression was stimulated by proinflammatory cytokines, but not by hypertrophic stimuli. A marked increase in PARM-1 expression was observed in response to ER stress inducers such as thapsigargin and tunicamycin, which also induced apoptotic cell death. Silencing PARM-1 expression by siRNAs enhanced apoptotic response in cardiac myocytes to ER stresses. PARM-1 silencing also repressed expression of PERK and ATF6, and augmented expression of CHOP without affecting IRE-1 expression and JNK and Caspase-12 activation. Thus, PARM-1 expression is induced by ER stress, which plays a protective role in cardiac myocytes through regulating PERK, ATF6 and CHOP expression. These results suggested that PARM-1 is a novel ER transmembrane molecule involved in cardiac remodeling in hypertensive heart disease. 相似文献
83.
84.
DNA variations in two PgiC loci were investigated in 15 strains of Arabidopsis halleri ssp. gemmifera. In a 5.5-kb region of the PgiC1 locus, 127 nucleotide substitutions and 33 length variations were observed. In a 6.0-kb region of the PgiC2 locus, 138 nucleotide substitutions and 33 length variations were observed. Frame shift, novel stop codons, and large length variations were observed in the PgiC2 coding region. These findings suggested that PgiC2 may be a pseudogene. The nucleotide diversities (pi) for the entire regions of both PgiC loci were approximately 0.0033. Tajima's test of both PgiC loci yielded significantly negative results. In the coding regions, the high proportions of replacement substitutions caused significant deviations from neutrality in McDonald and Kreitman's test. An excess of singletons and a high proportion of replacement polymorphic sites have been observed in the Adh and ChiA regions of A. halleri ssp. gemmifera. Thus, the A. halleri ssp. gemmifera population may not have reached equilibrium, and thus nonneutral patterns of DNA polymorphism were observed. 相似文献
85.
Matsuda A Itoh Y Koshikawa N Akizawa T Yana I Seiki M 《The Journal of biological chemistry》2003,278(38):36350-36357
MT6-MMP/MMP-25 is the latest member of the membrane-type matrix metalloproteinase (MT-MMP) subgroup in the MMP family and is expressed in neutrophils and some brain tumors. The proteolytic activity of MT6-MMP has been studied using recombinant catalytic fragments and shown to degrade several components of the extracellular matrix. However, the activity is possibly modulated further by the C-terminal hemopexin-like domain, because some MMPs are known to interact with other proteins through this domain. To explore the possible function of this domain, we purified a recombinant MT6-MMP with the hemopexin-like domain as a soluble form using a Madin-Darby canine kidney cell line as a producer. Mature and soluble MT6-MMP processed at the furin motif was purified as a 45-kDa protein together with a 46-kDa protein having a single cleavage in the hemopexin-like domain. Interestingly, 73- and 70-kDa proteins were co-purified with the soluble MT6-MMP by forming stable complexes. They were identified as clusterin, a major component of serum, by N-terminal amino acid sequencing. MT1-MMP that also has a hemopexin-like domain did not form a complex with clusterin. MT6-MMP forming a complex with clusterin was detected in human neutrophils as well. The enzyme activity of the soluble MT6-MMP was inactive in the clusterin complex. Purified clusterin was inhibitory against the activity of soluble MT6-MMP. On the other hand, it had no effect on the activities of MMP-2 and soluble MT1-MMP. Because clusterin is an abundant protein in the body fluid in tissues, it may act as a negative regulator of MT6-MMP in vivo. 相似文献
86.
Binding to EGF receptor of a laminin-5 EGF-like fragment liberated during MMP-dependent mammary gland involution 总被引:16,自引:0,他引:16 下载免费PDF全文
Schenk S Hintermann E Bilban M Koshikawa N Hojilla C Khokha R Quaranta V 《The Journal of cell biology》2003,161(1):197-209
Extracellular matrix (ECM) fragments or cryptic sites unmasked by proteinases have been postulated to affect tissue remodeling and cancer progression. Therefore, the elucidation of their identities and functions is of great interest. Here, we show that matrix metalloproteinases (MMPs) generate a domain (DIII) from the ECM macromolecule laminin-5. Binding of a recombinant DIII fragment to epidermal growth factor receptor stimulates downstream signaling (mitogen-activated protein kinase), MMP-2 gene expression, and cell migration. Appearance of this cryptic ECM ligand in remodeling mammary gland coincides with MMP-mediated involution in wild-type mice, but not in tissue inhibitor of metalloproteinase 3 (TIMP-3)-deficient mice, supporting physiological regulation of DIII liberation. These findings indicate that ECM cues may operate via direct stimulation of receptor tyrosine kinases in tissue remodeling, and possibly cancer invasion. 相似文献
87.
Codon usage in nuclear genes of four monocot and three dicot species was analyzed to find general patterns in codon choice of plant species. Codon bias was correlated with GC content at the third codon position. GC contents were higher in monocot species than in dicot species at all codon positions. The high GC contents of monocot species might be the result of relatively strong mutational bias that occurred in the lineage of the Poaceae species. In both dicot and monocot species, the effective number of codons (ENCs) for most genes was similar to that for the expected ENCs based on the GC content at the third codon positions. G and C ending codons were detected as the "preferred" codons in monocot species, as in Drosophila. Also, many "preferred" codons are the same in dicot species. Pyrimidine (C and T) is used more frequently than purine (G and A) in four-fold degenerate codon groups. 相似文献
88.
Yoshiharu Nishida Kenichi Hirano Kosuke Tsukamoto Makoto Nagano Chiaki Ikegami Kirsten Roomp Mitsuaki Ishihara Naoki Sakane Zhongyan Zhang Ken-ichi Tsujii Ki Akifumi Matsuyama Tohru Ohama Fumihiko Matsuura Masato Ishigami Naohiko Sakai Hisatoyo Hiraoka Hiroaki Hattori Cheryl Wellington Yoshihide Yoshida Susumu Misugi Michael R Hayden Toru Egashira Shizuya Yamashita Yuji Matsuzawa 《Biochemical and biophysical research communications》2002,290(2):713-721
ATP-binding cassette transporter-1 (ABCA1) gene is mutated in patients with familial high-density lipoprotein deficiency (FHD). In order to know the molecular basis for FHD, we characterized three different ABCA1 mutations associated with FHD (G1158A/A255T, C5946T/R1851X, and A5226G/N1611D) with respect to their expression in the passaged fibroblasts from the patients and in the cells transfected with the mutated cDNAs. Fibroblasts from the all patients showed markedly decreased cholesterol efflux to apolipoprotein (apo)-Al. In the fibroblasts homozygous for G1158A/A255T, the immunoreactive mass of ABCA1 could not be detected, even when stimulated by 9-cis-retinoic acid and 22-R-hydroxycholesterol. In the fibroblasts homozygous for C5946T/R1851X, ABCA1 mRNA was comparable. Because the mutant ABCA1 protein (R1851X) was predicted to lack the epitope for the antibody used, we transfected FLAG-tagged truncated mutant (R1851X/ABCA1-FLAG) cDNA into Cos-7 cells, showing that the mutant protein expression was markedly reduced. The expression of N1611D ABCA1 protein was comparable in both fibroblasts and overexpressing cells, although cholesterol efflux from the cells was markedly reduced. These data indicated that, in the three patients investigated, the abnormalities and dysfunction of ABCA1 occurred at the different levels, providing important information about the expression, regulation, and function of ABCA1. 相似文献
89.
90.
Kazuo Yoshida Michio Hagiya Naohiko Yanagishima 《Biochemical and biophysical research communications》1976,71(4):1085-1094
The substance responsible for the sexual agglutinability was successfully solubilized by a newly established autoclaving method from the surface of mating type cells of and purified by DEAE cellulose chromatography, gel filtration, affinity chromatography and electrophoresis. The substance was found to consist of at least two different glycoprotein subunits. The molecular weight of the substance was estimated to be about 23,000 daltons by gel filtration. The substance was univalent in its biological activity and specifically masked the sexual agglutinability of the mating type α cells. The substance formed a complementary complex with the agglutination substance from α cells in vitro. 相似文献