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971.
Yanai K Sato K Masuda S Ikeda M Kinae N 《Bioscience, biotechnology, and biochemistry》2006,70(10):2501-2507
Tienchi ginseng tea was prepared from stems and leaves of Tienchi ginseng which is a special product in China. The increase in systolic blood pressure (SBP) was significantly inhibited by the consumption of a 4% this tea solution as drinking water from the prehypertensive stage (6 weeks of age) in male stroke-prone spontaneously hypertensive rats (SHRSP). A similar intake from the hypertensive stage also showed an anti-hypertensive effect. In contrast, a similar intake had no effect on SBP of normotensive Wistar Kyoto rats. We found that the rhizome of Tienchi ginseng contained two types of saponin: 20(s)-protopanaxadiol (PPD) such as ginsenosides Rb(1) and Rd having a hypotensive effect, and 20(s)-protopanaxatriol (PPT) such as ginsenosides Rg(1) and Re having a hypertensive effect. In contrast, the tea sample contained PPD and gamma-aminobutyric acid (GABA), but no PPT. These results suggest that drinking this tea infusion would be useful for controlling hypertension. 相似文献
972.
Studies of chemotaxis in the social amoeba Dictyostelium discoideum have revealed numerous conserved signaling networks that are activated by chemoattractants. In the presence of a uniformly distributed stimulus, these pathways are transiently activated, but in a gradient they are activated persistently and can be localized to either the front or the back of the cell. Recent studies have begun to elucidate how chemoattractant signaling regulates the three main components of chemotaxis: directional sensing, pseudopod extension, and polarization. 相似文献
973.
Four kinds of N-dansyl-amino acid-modified beta-cyclodextrins (beta-CDs) were prepared as fluorescent chemosensors for chiral discrimination. The use of an amino acid as a spacer improved binding affinities and chiral discrimination abilities of the chemosensors. N-dansyl-l-Phe-modified beta-CD showed high d-selectivity for norbornane derivatives and N-dansyl-d-Phe-modified beta-CD showed high l-selectivity for menthol. Microcalorimetric titration results indicate that the chemosensors selectively accommodate the enantiomer that induces the least unfavorable entropy change on making an inclusion complex. 相似文献
974.
975.
Arsenic Trioxide Inhibits Hepatitis C Virus RNA Replication through Modulation of the Glutathione Redox System and Oxidative Stress
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Misao Kuroki Yasuo Ariumi Masanori Ikeda Hiromichi Dansako Takaji Wakita Nobuyuki Kato 《Journal of virology》2009,83(5):2338-2348
Arsenic trioxide (ATO), a therapeutic reagent used for the treatment of acute promyelocytic leukemia, has recently been reported to increase human immunodeficiency virus type 1 infectivity. However, in this study, we have demonstrated that replication of genome-length hepatitis C virus (HCV) RNA (O strain of genotype 1b) was notably inhibited by ATO at submicromolar concentrations without cell toxicity. RNA replication of HCV-JFH1 (genotype 2a) and the release of core protein into the culture supernatants were also inhibited by ATO after the HCV infection. To clarify the mechanism of the anti-HCV activity of ATO, we examined whether or not PML is associated with this anti-HCV activity, since PML is known to be a target of ATO. Interestingly, we observed the cytoplasmic translocation of PML after treatment with ATO. However, ATO still inhibited the HCV RNA replication even in the PML knockdown cells, suggesting that PML is dispensable for the anti-HCV activity of ATO. In contrast, we found that N-acetyl-cysteine, an antioxidant and glutathione precursor, completely and partially eliminated the anti-HCV activity of ATO after 24 h and 72 h of treatment, respectively. In this context, it is worth noting that we found an elevation of intracellular superoxide anion radical, but not hydrogen peroxide, and the depletion of intracellular glutathione in the ATO-treated cells. Taken together, these findings suggest that ATO inhibits the HCV RNA replication through modulation of the glutathione redox system and oxidative stress.Hepatitis C virus (HCV) is the causative agent of chronic hepatitis, which progresses to liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped virus with a positive single-stranded 9.6-kb RNA genome, which encodes a large polyprotein precursor of approximately 3,000 amino acid residues. This polyprotein is cleaved by a combination of the host and viral proteases into at least 10 proteins in the following order: core, envelope 1 (E1), E2, p7, nonstructural 2 (NS2), NS3, NS4A, NS4B, NS5A, and NS5B (30).Alpha interferon has been used as an effective anti-HCV reagent in clinical therapy for patients with chronic hepatitis C. The current combination treatment with pegylated alpha interferon and ribavirin, a nucleoside analogue, has been shown to improve the sustained virological response rate to more than 50% (15). However, the adverse effects of the combination therapy and the limited efficacy against genotype 1b warrant the development of new anti-HCV reagents.Arsenic trioxide (ATO) (As2O3, arsenite) has been used as a therapeutic reagent in acute promyelocytic leukemia, which bears an oncogenic PML-retinoic acid receptor alpha fusion protein resulting from chromosomal translocation (51, 52, 68, 70). The ATO treatment induces complete remission through degradation of the aberrant PML-retinoic acid receptor α (70). The PML tumor suppressor protein is required for formation of the PML nuclear body (PML-NB), also known as nuclear dot 10 or the PML oncogenic domain, which is often disrupted by infection with DNA viruses, such as herpes simplex virus type 1, human cytomegalovirus, and Epstein-Barr virus (17). The treatment with ATO results in degradation of the PML protein and disruption of the PML-NB (70). Therefore, ATO has been become a useful probe for investigating the functions of the PML-NB, including cell growth, apoptosis, stress response, and viral infection. Indeed, ATO has been shown to increase retroviral infectivity, such as human immunodeficiency virus type 1 (HIV-1) and murine leukemia virus infectivity, but the mechanisms of this change are not well understood (5, 6, 32, 44, 47, 50, 57). In contrast, ATO was recently reported to inhibit the replication of HCV subgenomic replicon RNA (24). However, it also remains unclear how ATO inhibits the HCV RNA replication. In this study, using genome-length HCV RNA replication systems, we investigated the molecular mechanism(s) of the anti-HCV activity of ATO, and we provide evidence that ATO inhibits HCV RNA replication through modulation of the glutathione redox system and oxidative stress. 相似文献
976.
Kikuko Ikeda Yuji NakayamaMayuko Ishii Yuuki ObataKousuke Kasahara Yasunori FukumotoNaoto Yamaguchi 《Biochimica et Biophysica Acta (BBA)/General Subjects》2009
Background
The Src-family non-receptor-type tyrosine kinase Lyn, which is often associated with chemotherapeutic resistance in cancer, localizes not only to the plasma membrane but also Golgi membranes. Recently, we showed that Lyn, which is synthesized in the cytosol, is transported from the Golgi to the plasma membrane along the secretory pathway. However, it is still unclear how Golgi targeting of newly synthesized Lyn is regulated.Methods
Subcellular localization of Lyn and its mutants was determined by confocal microscopy.Results
We show that the kinase domain, but not the SH3 and SH2 domains, of Lyn is required for the targeting of Lyn to the Golgi, whereas the N-terminal lipids of the Lyn SH4 domain are not sufficient for its Golgi targeting. Although intact Lyn, which colocalizes with caveolin-positive Golgi membranes, can traffic toward the plasma membrane, kinase domain-deleted Lyn is immobilized on caveolin-negative Golgi membranes.General significance
Besides the SH4 domain, the Lyn kinase domain is important for targeting of newly synthesized Lyn to the Golgi, especially caveolin-positive transport membranes. Our results provide a novel role of the Lyn catalytic domain in the Golgi targeting of newly synthesized Lyn in a manner independent of its kinase activity. 相似文献977.
Fumishige Oseko Toshiro Yamamoto Yuki Akamatsu Narisato Kanamura Yoichiro Iwakura Jiro Imanishi Masakazu Kita 《Microbiology and immunology》2009,53(5):287-294
Periapical lesions are induced by bacterial infection of the dental pulp and result in destruction of the surrounding alveolar bone. Although various immunological studies concerning periapical bone resorption have been reported, the role of cytokines in the formation of periapical lesions remains unclear. In this study, the role of IL-17A in periapical lesions in mice was investigated. Normal C57BL/6, IFN-γ−/− , TNF-α−/− , and IL-17A−/− mice were subjected to pulp exposure and infected with Prevotella intermedia (ATCC25611) and Porphyromonas gingivalis (ATCC33277) in the mandibular first molar. Periapical lesions were determined by μCT on day 21 after infection, and 3D visual construction was performed using 3D picture quantification software. The expression of IL-17A mRNA in periapical lesions was determined by the RT-PCR and real-time RT-PCR method. Periapical lesions developed in wild-type, IFN-γ−/− , and TNF-α−/− mice after infection with P. intermedia and P. gingivalis . However, periapical lesions were not observed in IL-17A−/− mice. The expression of IL-17A mRNA was significantly induced in periapical lesions of wild-type mice after infection. These results suggest that IL-17A, but not IFN-γ or TNF-α, plays an important role in the formation of periapical lesions. 相似文献
978.
Kaori Tanaka Tsukasa Hori Naoki Hatakeyama Masaki Yamamoto Rumiko Takayama Yuko Yoto Nobuhiro Suzuki Toshiaki Hayashi Yukiho Ikeda Hiroshi Ikeda Tadao Ishida Hiroyuki Tsutsumi 《Microbiology and immunology》2009,53(6):319-322
BK polyomavirus (BKV) is ubiquitous among humans, usually infecting them asymptomatically during childhood. BKV persists in renal tissue of individuals and their progeny are excreted in urine, particularly in immunocompromised patients. JC virus, another human polyomavirus, has been considered to be transmitted from parents to children during prolonged cohabitation. However, BKV has been supposed to be transmitted not only within but also outside the family. In the present study, to clarify this possibility, we analyzed phylogenetically 35 BKV which were excreted in the urine by Japanese children and adults undergoing stem cell transplantation. Subtypes I, III and IV were detected in 15, two and one children and in 15, one and one adults, respectively. Among 15 subtype I isolates from children, three, four and eight belonged to subgroups Ia, Ib-1 and Ic, respectively. All the three children from whom Ia was detected were less than 9 years old. In contrast in the adults, three subtype I belonged to Ib-1 and the other 12 to Ic. These findings may reflect the recent transmission of BKV Ia strains to Japanese children. 相似文献
979.
Nobuyoshi Koshino Tamás R. Varga Motoo Shiro Yasuhisa Ikeda 《Inorganica chimica acta》2009,362(10):3433-2112
Homoleptic eight- and nine-coordinate U(IV) perchlorate complexes with sulfoxide ligands have been characterized crystallographically. Crystals of [U(dmso)8](ClO4)4 · 0.75CH3NO2, [U(dmso)9](ClO4)4 · 4dmso (dmso = dimethyl sulfoxide), and [U(tmso)8](ClO4)4 · 2tmso (tmso = tetramethylene sulfoxide) were found to have dodecahedral, tricapped trigonal prismatic, and square antiprismatic geometries, respectively. Average U-O bond distances in [U(dmso)8](ClO4)4 · 0.75CH3NO2, [U(dmso)9](ClO4)4 · 4dmso, and [U(tmso)8](ClO4)4 · 2tmso are 2.35(3), 2.41 (4), and 2.35(3) Å, respectively. Furthermore, it was found that [U(dmso)8]4+ is in equilibrium with [U(dmso)9]4+ in CH3NO2 solution containing dmso. Thermodynamic parameters for such an equilibrium are as follows: K (25 °C) = 3.4 ± 0.2 dm3 mol−1, ΔH = −54.9 ± 4.5 kJ mol−1, and ΔS = −174 ± 15 J K−1 mol−1. 相似文献
980.
Miyashita M Ito N Ikeda S Murayama T Oguma K Kimura J 《Biosensors & bioelectronics》2009,24(5):1336-1340
The highly sensitive urine glucose meter based on amperometric glucose sensor was developed and commercialized. It shows remarkable performances of wide measurement range in 0-2000 mgdl(-1), rapid response time as 6s and robustness against influence by interferents like ascorbic acid or acetaminophen. Correlation between the developed urine glucose meter and commercialized clinical-use urine glucose analyzer showed excellent linear relationship. The monitoring of postmeal blood glucose levels by assess of urine glucose of actual subjects was performed with the developed urine glucose meter. The experimental results suggest the urine glucose level 120 min following the meal should be the appropriate index for diabetes or impaired glucose tolerance to control blood glucose level. The new portable meter was developed, and is expected for flexible use at places other than home or office. 相似文献