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21.
Shigehara T Mitsuhashi H Ota F Kuroiwa T Kaneko Y Ueki K Tsukada Y Maezawa A Nojima Y 《Life sciences》2002,70(19):2225-2232
Sulfite is a major air pollutant which can cause respiratory tract inflammation characterized by an influx of polymorphonuclear neutrophils (PMN). We have previously shown that human PMN can produce sulfite either spontaneously or in response to stimulation with lipopolysaccharide. We now demonstrate that sulfite activates PMN to adhere to immobilized fibrinogen via the beta2-integrin Mac-1 (CD11b/CD18). Mac-1 expression is not altered by treatment with this agent. Although unaffected by pertussis toxin, sulfite-triggered PMN adhesion was abrogated by pretreating cells with the membrane-impermeant sulfhydryl reagent 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), a modifier of thiol groups on the cell surface. These results suggest that sulfite-induced PMN adhesion is dependent on a modification of thiols at the cell surface. Given its potent antioxidant and antimicrobial activities, sulfite may act as an endogenous mediator in host defense and/or inflammation. 相似文献
22.
Lack of mannose-binding lectin-A enhances survival in a mouse model of acute septic peritonitis 总被引:8,自引:0,他引:8
Takahashi K Gordon J Liu H Sastry KN Epstein JE Motwani M Laursen I Thiel S Jensenius JC Carroll M Ezekowitz RA 《Microbes and infection / Institut Pasteur》2002,4(8):773-784
The mannose-binding lectin (MBL) (also known as the mannose-binding protein) is a serum protein that plays a role as an "ante-antibody" in innate immunity. In man, MBL is encoded by a single gene, whereas in mice there are two homologous proteins, MBL-A and MBL-C. In order to evaluate the relative roles of these two forms of MBL, we created MBL-A null mice that were MBL-C sufficient. We found MBL-A null mice had enhanced survival in a septic peritonitis model compared to wild-type mice and complement 3 null mice at 24 h, 48 h and 10 d (P < 0.05). Reconstitution of these mice with human MBL reversed the phenotype. Surviving mice had significantly decreased TNF-alpha and IL-6 levels in the blood and peritoneal cavity (P < 0.01). In vitro studies indicate that bacteria opsonized with MBL-A-deficient serum induced significantly less cytokine by peritoneal macrophages compared to those with wild-type serum. Our results indicate that MBL-A is a modulator of inflammation in vivo and in vitro in the mouse and that the role of MBL may extend beyond its role as an opsonin. 相似文献
23.
Ichikawa H Satoh K Tobe T Yasuda I Ushio F Matsumoto K Endo K Ookubo C 《Redox report : communications in free radical research》2002,7(5):347-350
We investigated the radical scavenging activity of propolis by ESR spectroscopy using spin trapping method. In addition, we examined the influence of a diet of 2% propolis on mice under oxidative stress. At low concentrations, the methanolic extract of propolis exhibited strong scavenging activity in vitro towards both the superoxide anion radical, generated by the hypoxanthine-xanthine oxidase reaction, and the NO radical, generated from the mixture of NOC-7 (NO generator) and carboxy-PTIO (spin trapping agent). An inhibitory effect of propolis on lipid peroxidation in vivo was observed, as determined by measurement of thiobarbituric acid-reactive substances in mouse liver homogenate. The level of vitamin C in the brain of mice under oxidative stress significantly increased compared with control mice under atmosphere, which was not observed in the mice given 2% propolis. The level of alpha-tocopherol in the brain of mice given 2% propolis significantly increased compared with control mice under atmosphere, which was not observed in mice under oxidative stress. SOD activity in the brain and plasma of mice given 2% propolis significantly decreased under atmosphere and oxidative stress compared with control mice. These results suggest that propolis possesses potent antioxidant activity in vitro and in vivo. 相似文献
24.
Phosphorylation of retinoblastoma-related protein by the cyclin D/cyclin-dependent kinase complex is activated at the G1/S-phase transition in tobacco
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In mammals, D-type cyclin-associated kinases mainly regulate the G1/S transition by phosphorylating the retinoblastoma (Rb) protein. We previously demonstrated that in tobacco, cyclin D (Nicta; CycD3;3) is complexed with the PSTAIRE-containing cyclin-dependent kinase (CDKA) from tobacco. Here, we show that Nicta; CycD3;3-associated kinases phosphorylate both the tobacco Rb-related protein (NtRb1) and histone H1. Although NtRb1 kinase activity was detected only during the middle G1- to early S-phase, histone H1 kinase activity was observed as two peaks in G1- to S-phase and G2/M- to M-phase. Importantly, we show that the proportion of cells in the G1-phase was reduced in transgenic Bright Yellow-2 cells overexpressing Nicta; CycD3;3-GFP. Mutational analyses revealed that phosphorylation of Thr-191 in Nicta; CycD3;3 possibly is required for both full kinase activity and localization predominantly to the nucleus. These data suggest that Nicta; CycD3;3 acts as a rate-limiting regulator in the G1/S transition by forming active complexes with CDKA or its related kinases to phosphorylate Rb-related protein and potentially plays a novel role during G2/M and mitosis. 相似文献
25.
Ishimoto T Ninomiya K Miyaji K Uyeda A Kasai M Taguchi T 《Biochimica et biophysica acta》2002,1579(2-3):189-195
Although a subpopulation of mRNAs has been identified as translocated to the dendrites or the synaptic regions of neurons, the translocational mechanism has not been elucidated. To find mRNAs enriched in synapses, we compared the synaptosomal mRNAs with those from whole forebrain using differential display (DD). We cloned one of these mRNAs, which encoded a novel 31 kDa protein (PMES-2). PMES-2 mRNA was specifically transcribed in the brain and was present in the dendrites of the hippocampal neurons. PMES-2 protein was partly localized in the postsynaptic density. Although this protein is very similar to human NABC1 protein, its function is still unknown. 相似文献
26.
Iwakura T Fujimoto S Kagimoto S Inada A Kubota A Someya Y Ihara Y Yamada Y Seino Y 《Biochemical and biophysical research communications》2000,271(2):422-428
Cytosolic Ca(2+) elevations are known to be involved in triggering apoptosis in many tissues, but the effect of sustained enhancement of Ca(2+) influx on apoptosis in beta cells remains unknown. We have found that the viability of RINm5F cells is decreased dose-dependently by continuous exposure to glibenclamide at concentrations from 10(-7) to 10(-4) M, and that this effect is partially ameliorated by pretreatment with cycloheximide. Electrophoresis of the cells exposed to glibenclamide revealed ladder-like fragmentation characteristic of apoptosis, and which also is suppressed by cycloheximide pretreatment. By using terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, we detected increased DNA fragmentation in the nuclei of the cells exposed to glibenclamide, and staining with Hoechst 33342 and propidium iodide showed a dose-dependent increase in the number of cells with the chromatin condensation and fragmentation in their nuclei that is characteristic of apoptosis. The effects of glibenclamide on cell viability and apoptotic cell death were partially inhibited by treatment with Ca(2+) channel blocker, and by reducing the extracellular Ca(2+) concentration during glibenclamide exposure, suggesting that they may be derived from increased Ca(2+) influx. Furthermore, only the percentage of apoptotic cells, and not that of necrotic cells, increased with the increasing intracellular Ca(2+) concentration during glibenclamide exposure. In conclusion, we have demonstrated that the sustained enhancement of Ca(2+) influx caused by glibenclamide exposure can induce apoptotic cell death in a pure beta cell line. 相似文献
27.
Flavia Kazue Ibuki Alyne Simões Fernando Neves Nogueira 《Cell biochemistry and function》2010,28(6):503-508
Hyperglycemia induces overproduction of superoxide and it is related to diabetic complications. In this study, we analyzed the antioxidant enzymatic defense and the lipid peroxidation of rat salivary glands in six different periods of diabetic condition. Ninety‐six rats were divided into 12 groups: C7/14/21/28/45/60 (non‐diabetic animals) and D7/14/21/28/45/60 (diabetic animals). Diabetes was induced by streptozotocin and the rats were euthanized after 7, 14, 21, 28, 45, or 60 days. Their parotid (PA) and submandibular (SM) glands were removed soon after the sacrifice and the total protein and malondialdehyde (MDA) concentrations, as well as, the superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities were determined. Twenty‐one days after the diabetes induction, the SM glands showed an increase in SOD, CAT, and GPx activities, as well as, MDA concentration. Concerning the PA glands, an increase in the CAT activity and MDA content was observed throughout the observation period. The results suggest that diabetes can cause alterations on the salivary glands and that PA and SM glands react differently when exposed to diabetes condition. However, no impairment of antioxidant system was observed in the group whose diabetic condition had been induced 60 days earlier, herein named 60‐day group. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
28.
The basolateral amygdala complex (BLA), including the lateral (LA), basal (BA) and accessory basal (AB) nuclei, is involved in acquisition of contextual and auditory fear conditioning. The BA is one of the main targets for hippocampal information, a brain structure critical for contextual learning, which integrates several discrete stimuli into a single configural representation. Congruent with the hodology, selective neurotoxic damage to the BA results in impairments in contextual, but not auditory, fear conditioning, similarly to the behavioral impairments found after hippocampal damage. This study evaluated the effects of muscimol-induced reversible inactivation of the BA during a simultaneous contextual and auditory fear conditioning training on later fear responses to both the context and the tone, tested separately, without muscimol administration. As compared to control rats micro-infused with vehicle, subjects micro-infused with muscimol before training exhibited, during testing without muscimol, significant reduction of freezing responses to the conditioned context, but not to the conditioned tone. Therefore, reversible inactivation of the BA during training impaired contextual, but not auditory fear conditioning, thus confirming and extending similar behavioral observations following selective neurotoxic damage to the BA and, in addition, revealing that this effect is not related to the lack of a functional BA during testing. 相似文献
29.
DNA barcoding reveals 24 distinct lineages as cryptic bird species candidates in and around the Japanese Archipelago 总被引:1,自引:0,他引:1
Takema Saitoh Norimasa Sugita Sayaka Someya Yasuko Iwami Sayaka Kobayashi Hiromi Kamigaichi Aki Higuchi Shigeki Asai Yoshihiro Yamamoto Isao Nishiumi 《Molecular ecology resources》2015,15(1):177-186
DNA barcoding using a partial region (648 bp) of the cytochrome c oxidase I (COI) gene is a powerful tool for species identification and has revealed many cryptic species in various animal taxa. In birds, cryptic species are likely to occur in insular regions like the Japanese Archipelago due to the prevention of gene flow by sea barriers. Using COI sequences of 234 of the 251 Japanese‐breeding bird species, we established a DNA barcoding library for species identification and estimated the number of cryptic species candidates. A total of 226 species (96.6%) had unique COI sequences with large genetic divergence among the closest species based on neighbour‐joining clusters, genetic distance criterion and diagnostic substitutions. Eleven cryptic species candidates were detected, with distinct intraspecific deep genetic divergences, nine lineages of which were geographically separated by islands and straits within the Japanese Archipelago. To identify Japan‐specific cryptic species from trans‐Paleartic birds, we investigated the genetic structure of 142 shared species over an extended region covering Japan and Eurasia; 19 of these species formed two or more clades with high bootstrap values. Excluding six duplicated species from the total of 11 species within the Japanese Archipelago and 19 trans‐Paleartic species, we identified 24 species that were cryptic species candidates within and surrounding the Japanese Archipelago. Repeated sea level changes during the glacial and interglacial periods may be responsible for the deep genetic divergences of Japanese birds in this insular region, which has led to inconsistencies in traditional taxonomies based on morphology. 相似文献
30.