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61.
Kurita-Ochiai T Amano S Fukushima K Ochiai K 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(7):3576-3584
We have previously demonstrated that butyric acid induces cytotoxicity and apoptosis of murine thymocytes, splenic T cells, and human Jurkat T cells. Therefore, to determine the apoptotic signaling pathway induced by butyric acid, we investigated the contribution of reactive oxygen species (ROS), mitochondria, ceramide, and mitogen-activated protein kinases in butyric acid-induced human Jurkat cell apoptosis. After exposure of cells to butyric acid, a pronounced accumulation of ROS was seen. Pretreatment of cells with the antioxidant N-acetyl-cysteine or 3-aminobenzamide attenuated butyric acid-induced apoptosis through a reduction of ROS generation. Cytochrome c, apoptosis-inducing factor, and second mitochondria-derived activator of caspases protein release from mitochondria into the cytosol were detected shortly after butyric acid treatment. Exposure of cells to butyric acid resulted in an increase in cellular ceramide in a time-dependent fashion. In addition, butyric acid-induced apoptosis was inhibited by DL-threo-dihidrosphingosine, a potent inhibitor of sphingosine kinase. Using anti-extracellular signal-regulated kinase (ERK), anti-c-Jun N-terminal kinase (JNK), and anti-p38 phosphospecific Abs, we showed a decrease in ERK, but not in JNK and p38 phosphorylation after treatment of cells with butyric acid. Pretreatment of cells with the JNK inhibitor SP600125 attenuated the effect of butyric acid on apoptosis, whereas no effect was seen with the p38 inhibitor SB202190 or the ERK inhibitor PD98059. Taken together, our results indicate that butyric acid-induced T cell apoptosis is mediated by ceramide production, ROS synthesis in mitochondria, and JNK activation in the mitogen-activated protein kinase cascade. Finally, these results were further substantiated by the expression profile of butyric acid-treated Jurkat cells obtained by means of cDNA array. 相似文献
62.
Sueyoshi Kuni; Kubo Yoshihiro; Yamagishi Kenji; Ogura Nagao; Ochiai Kuniyasu; Fukushima Kazuo; Ikeda Tadashi; Nakagawa Hiroki 《Plant & cell physiology》1988,29(6):975-980
Two monoclonal antibodies, 17(3)9 and 36(79)4, were preparedagainst nitrate reductase from Spinacia oleracea L. leaves.An enzyme-linked immunosorbent assay showed that 17(3)9, butnot 36(79)4, reacted more strongly to heat-denatured than nativeantigen. These antibodies inhibited NADH-nitrate reductase aswell as its various partial activities including reduced methylvilogen-nitrate reductase, reduced flavin mononucleotide-nitratereductase and NADH-cytochrome c reductase activities, but notNADH-ferricyanide reductase activity. Immunoblotting after electrophoreticseparation of nitrate reductase fragments obtained by Staphyrococcusaureus V8 protease digestion of native enzyme revealed thatthe two monoclonal antibodies bind to different epitopes locatedon the 28 kDa of the NADH-ferricyanide reductase domain. (Received October 2, 1987; Accepted June 9, 1988) 相似文献
63.
64.
Haruko Ogawa Ako Hijikata Maho Amano Kyoko Kojima Hisako Fukushima Ineo Ishizuka Yoshie Kurihara Isamu Matsumoto 《Glycoconjugate journal》1996,13(4):555-566
The oligosaccharide structures ofCry j I, a major allergenic glycoprotein ofCryptomeria japonica (Japanese cedar, sugi), were analysed by 400 MHz1H-NMR and two-dimensional sugar mapping analyses. The four major fractions comprised a series of biantennary complex type N-linked oligosaccharides that share a fucose/xylose-containing core and glucosamine branches including a novel structure with a nongalactosylated fucosylglucosamine branch.Rabbit polyclonal anti-Cry j I IgG antibodies cross-reacted with three different plant glycoproteins having the same or shorter N-linked oligosaccharides asCry j I. ELISA and ELISA inhibition studies with intact glycoproteins, glycopeptides and peptides indicated that both anti-Cry j I IgGs and anti-Sophora japonica bark lectin II (B-SJA-II) IgGs included oligosaccharide-specific antibodies with different specificities, and that the epitopic structures against anti-Cry j I IgGs include a branch containing 1–6 linked fucose and a core containing fucose/xylose, while those against anti-B-SJA-II IgGs include nonreducing terminal mannose residues. The cross-reactivities of human allergic sera to miraculin andClerodendron Trichotomum lectin (CTA) were low, and inhibition studies suggested that the oligosaccharides onCry j I contribute little or only conformationally to the reactivity of specific IgE antibodies.Abbreviations
Cry j I
a major allergenic glycoprotein ofCryptomeria japonica
- B-SJA-II
Sophora japonica bark lectin II
- CTA
Clerodendron trichotomum lectin
- TFMS
trifluoromethanesulfonic acid
- HRP
horseradish peroxidase 相似文献
65.
It seems likely that the influences of light upon circadian rhythms will decrease with aging, particularly those rhythms that are more influenced by light with a higher color temperature and richer in short wavelengths. More specifically, cataract patients' optical systems transmit light poorly, especially the shorter wavelengths that affect the circadian system more. The present study investigated melatonin secretion profiles and sleep patterns before and after cataract surgery. Fifteen subjects were studied for 3 consecutive weekdays before, and one month after, their cataract surgery. UV-cutting intra-ocular lenses were used for patients after surgery. No statistically significant differences between before and after surgery were observed in the amount of light received and the amount of activity. This means that there were no significant changes in their lifestyle during the experimental period. Considering the group as a whole, no significant differences were present in melatonin secretion, sleep parameters, or sleepiness before and after the surgery. However, individual subjects responded differently. The subjects showed a negative correlation between the wake-up (p=0.067) or retiring times (p=0.017) and sleep efficiency after surgery. The amount of light received during the nighttime influenced sleep more significantly than during the daytime. 相似文献
66.
Chiao-Ting Yen Kyoko Nakagawa-Goto Tsong-Long Hwang Pei-Chi Wu Susan L. Morris-Natschke Wan-Chun Lai Kenneth F. Bastow Fang-Rong Chang Yang-Chang Wu Kuo-Hsiung Lee 《Bioorganic & medicinal chemistry letters》2010,20(3):1037-1039
The first total synthesis of the naturally occurring tetracyclic homoisoflavonoid brazilein (1) and 14 new analogs (1a–n) is reported. Target compounds and intermediates were assayed for anti-inflammatory effects on superoxide anion generation and elastase release by human neutrophils in response to fMLP/CB, and for cytotoxic activity against nasopharyngeal (KB), vincristine-resistant nasopharyngeal (KBvin), lung (A549) and prostate (DU-145) human cancer cell lines. The most active compound 1b showed potent effects on superoxide anion generation and elastase release with IC50 values of 1.2 and 1.9 μM, respectively, and was 65 times more potent than phenylmethylsulfonyl fluoride (PMSF), the positive control, in the latter assay. Additionally, 1b exhibited broad spectrum in vitro anticancer activity with IC50 values of 6–11 μM against the four tested cancer cell lines. 相似文献
67.
Junichi Nasu Kyoko Murakami Shoji Miyagawa Ryosuke Yamashita Tohru Ichimura Takaji Wakita Hak Hotta Tatsuo Miyamura Tetsuro Suzuki Tazuko Satoh Ikuo Shoji MD PhD 《Journal of cellular biochemistry》2010,111(3):676-685
E6‐associated protein (E6AP) is a cellular ubiquitin protein ligase that mediates ubiquitylation and degradation of tumor suppressor p53 in conjunction with the high‐risk human papillomavirus E6 protein. We previously reported that E6AP targets annexin A1 protein for ubiquitin‐dependent proteasomal degradation. To gain a better understanding of the physiological function of E6AP, we have been seeking to identify novel substrates of E6AP. Here, we identified peroxiredoxin 1 (Prx1) as a novel E6AP‐binding protein using a tandem affinity purification procedure coupled with mass spectrometry. Prx1 is a 25‐kDa member of the Prx family, a ubiquitous family of antioxidant peroxidases that regulate many cellular processes through intracellular oxidative signal transduction pathways. Immunoprecipitation analysis showed that E6AP binds Prx1 in vivo. Pull‐down experiments showed that E6AP binds Prx1 in vitro. Ectopic expression of E6AP enhanced the degradation of Prx1 in vivo. In vivo and in vitro ubiquitylation assays revealed that E6AP promoted polyubiquitylation of Prx1. RNAi‐mediated downregulation of endogenous E6AP increased the level of endogenous Prx1 protein. Taken together, our data suggest that E6AP mediates the ubiquitin‐dependent proteasomal degradation of Prx1. Our findings raise a possibility that E6AP may play a role in regulating Prx1‐dependent intracellular oxidative signal transduction pathways. J. Cell. Biochem. 111: 676–685, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
68.
Taurine prevents the ischemia-induced apoptosis in cultured neonatal rat cardiomyocytes through Akt/caspase-9 pathway 总被引:7,自引:0,他引:7
Takatani T Takahashi K Uozumi Y Matsuda T Ito T Schaffer SW Fujio Y Azuma J 《Biochemical and biophysical research communications》2004,316(2):484-489
Activated Akt kinase has been proposed as a central role in suppressing apoptosis by modulating the activities of Bcl-2 family proteins and/or caspase-9. To study the mechanism underlying the anti-apoptotic effect of taurine, the interaction between taurine and Akt/caspase-9 pathway was examined using a simulated ischemia model with cultured rat neonatal cardiomyocytes sealed in closed flasks. Taurine (20mM) treatment attenuated simulated ischemia-induced decline in the activity of Akt. Although taurine treatment had no effect on the expression of Bcl-2 in mitochondria and the level of cytosolic cytochrome c, it inhibited ischemia-induced cleavage of caspases 9 and 3. Moreover, adenovirus transfer of the dominant negative form of Akt objected taurine-mediated anti-apoptotic effects, cancelling the suppression of caspase-9 and caspase-3 activities by taurine. These findings provide the first evidence that taurine inhibits ischemia-induced apoptosis in cardiac myocytes with the increase in Akt activities, by inactivating caspase-9. 相似文献
69.
Loss of PGC-specific expression of the orphan nuclear receptor ERR-beta results in reduction of germ cell number in mouse embryos 总被引:7,自引:0,他引:7
Mitsunaga K Araki K Mizusaki H Morohashi K Haruna K Nakagata N Giguère V Yamamura K Abe K 《Mechanisms of development》2004,121(3):237-246
Estrogen related receptor beta (ERR-beta) is an orphan nuclear receptor specifically expressed in a subset of extra-embryonic ectoderm of post-implantation embryos. ERR-beta is essential for placental development since the ERR-beta null mutants die at 10.5dpc due to the placenta abnormality. Here, we show that the ERR-beta is specifically expressed in primordial germ cells (PGC), obviously another important cell type for reproduction. Expression of the ERR-beta mRNA in embryonic germ cells started at E11.5 as soon as PGC reached genital ridges, and persisted until E15-E16 in both sexes. Immunostaining with anti-ERR-beta antibody revealed that the ERR-beta protein is exclusively expressed in germ cells in both male and female gonads from E11.5 to E16. 5. To study function of the ERR-beta in PGC, we complemented placental defects of the ERR-beta null mutants with wild-type tetraploid embryos, and analyzed germ cell development in the rescued embryos. It was found that development of gonad and PGC was not apparently affected, but number of germ cells was significantly reduced in male and female gonads, suggesting that the ERR-beta appears to be involved in proliferation of gonadal germ cells. The rescued embryos could develop to term and grow up to adulthood. The rescued ERR-beta null male were found to be fertile, but both male and female null mutants exhibited behavioural abnormalities, implying that the ERR-beta plays important roles in wider biological processes than previously thought. 相似文献
70.
Yamada C Kijima K Ishihara S Miwa C Wada K Okada T Fukuyama K Kumagai H Suzuki H 《Applied and environmental microbiology》2008,74(11):3400-3409
7-Aminocephalosporanic acid (7-ACA) is an important material in the production of semisynthetic cephalosporins, which are the best-selling antibiotics worldwide. 7-ACA is produced from cephalosporin C via glutaryl-7-ACA (GL-7-ACA) by a bioconversion process using d-amino acid oxidase and cephalosporin acylase (or GL-7-ACA acylase). Previous studies demonstrated that a single amino acid substitution, D433N, provided GL-7-ACA acylase activity for gamma-glutamyltranspeptidase (GGT) of Escherichia coli K-12. In this study, based on its three-dimensional structure, residues involved in substrate recognition of E. coli GGT were rationally mutagenized, and effective mutations were then combined. A novel screening method, activity staining followed by a GL-7-ACA acylase assay with whole cells, was developed, and it enabled us to obtain mutant enzymes with enhanced GL-7-ACA acylase activity. The best mutant enzyme for catalytic efficiency, with a k(cat)/K(m) value for GL-7-ACA almost 50-fold higher than that of the D433N enzyme, has three amino acid substitutions: D433N, Y444A, and G484A. We also suggest that GGT from Bacillus subtilis 168 can be another source of GL-7-ACA acylase for industrial applications. 相似文献