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排序方式: 共有535条查询结果,搜索用时 15 毫秒
131.
Dettori S Argentini C Marcucci F Spada E Chionne P Candido A Madonna E Ciccaglione AR Bianco E Iannitto E Musto P Liso V De Renzo A Pagano L Nieddu G Pulsoni A Mele A Rapicetta M 《The new microbiologica》2007,30(3):265-270
We compared the E2-HVR1 region in HCV-1b positive B-NHL cases from a multicenter study with sequences from studies related to lymphoproliferative disorders and B cell compartmentalisation. We found rare and unique mutations both in B-NHL isolates and in cases with lymphoproliferative disorders and lymphocyte infection. These rare mutations could have an important effect on HVR1 region and, as a consequence, on the binding of E2 on CD81, with a possible implication for both antigenic stimulation and HCV entry. In conclusion, the HCV predominants circulating in B-NHL cases seem to be associated with clonal selection of rare variants. 相似文献
132.
The metabolic effects of prolonged starvation and refeeding in sturgeon and rainbow trout 总被引:2,自引:0,他引:2
Furné M Morales AE Trenzado CE García-Gallego M Carmen Hidalgo M Domezain A Sanz Rus A 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2012,182(1):63-76
The present study examines the particular metabolic strategies of the sturgeon Acipenser naccarii in facing a period of prolonged starvation (72 days) and subsequent refeeding (60 days) compared to the trout Oncorhynchus mykiss response under similar conditions. Plasma metabolites, endogenous reserves, and the activity of intermediate enzymes in liver
and white muscle were evaluated. This study shows the mobilization of tissue reserves during a starvation period in both species
with an associated enzymatic response. The sturgeon displayed an early increase in hepatic glycolysis during starvation. The
trout preferentially used lactate for gluconeogenesis in liver and white muscle. The sturgeon had higher lipid-degradation
capacity and greater synthesis of hepatic ketone bodies than the trout, although this latter species also showed strong synthesis
of ketone bodies during starvation. During refeeding, the metabolic activity present before starvation was recovered in both
fish, with a reestablishment of tissue reserves, plasmatic parameters (glucemia and cholesterol), and enzymatic activities
in the liver and muscle. A compensatory effect in enzymes regarding lipids, ketone bodies, and oxidative metabolism was displayed
in the liver of both species. There are metabolic differences between sturgeon and trout that support the contention that
the sturgeon has common characteristics with elasmobranchs and teleosts. 相似文献
133.
Fernández-Martínez A Mollá B Mayoral R Boscá L Casado M Martín-Sanz P 《The Biochemical journal》2006,398(3):371-380
We have investigated the mechanism of COX-2 (cyclo-oxygenase 2)-dependent inhibition of apoptosis in liver, a key pathway underlying proliferative actions of COX-2 in liver cancers, cirrhosis, chronic hepatitis C infection and regeneration after partial hepatectomy. Stable expression of COX-2 in CHL (Chang liver) cells induced proliferation, with an increase in the proportion of cells in S-phase, but no other significant changes in cell-cycle distribution. This was associated with a marked inhibition of the apoptotic response to serum deprivation, an effect mimicked by treating empty-vector-transfected control cells (CHL-V cells) with prostaglandin E2 and prevented in COX-2-expressing cells (CHL-C cells) treated with selective inhibitors of COX-2. Serum-deprived CHL-V cells displayed several indicators of activation of intrinsic apoptosis: caspases 9 and 3 activated within 6 h and caspase 8 within 18 h, Bax expression was induced, cytochrome c was released to the cytosol, and PARP-1 [poly(ADP-ribose) polymerase 1] cleavage was evident in nuclei. COX-2 expression blocked these events, concomitant with reduced expression of p53 and promotion of Akt phosphorylation, the latter indicating activation of survival pathways. CHL cells were resistant to stimulation of the extrinsic pathway with anti-Fas antibody. Moreover, in vivo expression of GFP (green fluorescent protein)-labelled COX-2 in mice by hydrodynamics-based transient transfection conferred resistance to caspase 3 activation and apoptosis induced by stimulation of Fas. 相似文献
134.
De Domenico I Lania A Bonaccorsi di Patti MC Battistoni A Musci G Desideri A 《Biochimica et biophysica acta》2006,1764(1):105-109
Recombinant Cu,Zn Superoxide Dismutase from Caulobacter crescentus has been expressed in Escherichia coli and characterized. The corresponding recombinant protein has a molecular weight typical of a homodimeric Cu,ZnSODs and an activity comparable to that of other prokaryotic enzymes. The copper active site is characterized by a peculiar axial geometry as evidenced by its electron paramagnetic resonance spectrum, moreover, the copper atom displays a low accessibility toward external chelating agents indicating a lower solvent accessibility when compared to other prokaryotic enzymes. Investigation of the enzyme thermal stability through differential scanning calorimetry indicates the occurrence of two transitions at low and higher temperature that are found to be due to the apo and holo protein, respectively, confirming that the metals have a crucial role in the stabilization of this class of enzymes. 相似文献
135.
25-hydroxycholesterol provokes oligodendrocyte cell line apoptosis and stimulates the secreted phospholipase A2 type IIA via LXR beta and PXR 总被引:2,自引:0,他引:2
Amalia Trousson† Sophie Bernard† Patrice X. Petit‡ Philippe Liere Antoine Pianos Khadija El Hadri§ Jean-Marc A. Lobaccaro¶ M. Said Ghandour Michel Raymondjean§ Michael Schumacher Charbel Massaad† 《Journal of neurochemistry》2009,109(4):945-958
In several neurodegenerative diseases of the CNS, oligodendrocytes are implicated in an inflammatory process associated with altered levels of oxysterols and inflammatory enzymes such as secreted phospholipase A2 (sPLA2). In view of the scarce literature related to this topic, we investigated oxysterol effects on these myelinating glial cells. Natural oxysterol 25-hydroxycholesterol (25-OH; 1 and 10 μM) altered oligodendrocyte cell line (158N) morphology and triggered apoptosis (75% of apoptosis after 72 h). These effects were mimicked by 22( S )-OH (1 and 10 μM) which does not activate liver X receptor (LXR) but not by a synthetic LXR ligand (T0901317). Therefore, oxysterol-induced apoptosis appears to be independent of LXR. Interestingly, sPLA2 type IIA (sPLA2-IIA) over-expression partially rescued 158N cells from oxysterol-induced apoptosis. In fact, 25-OH, 24( S )-OH, and T0901317 stimulated sPLA2-IIA promoter and sPLA2 activity in oligodendrocyte cell line. Accordingly, administration of T0901317 to mice enhanced sPLA2 activity in brain extracts by twofold. Short interfering RNA strategy allowed to establish that stimulation of sPLA2-IIA is mediated by pregnane X receptor (PXR) at high oxysterol concentration (10 μM) and by LXR β at basal oxysterol concentration. Finally, GC coupled to mass spectrometry established that oligodendrocytes contain oxysterols and express their biosynthetic enzymes, suggesting that they may act through autocrine/paracrine mechanism. Our results show the diversity of oxysterol signalling in the CNS and highlight the positive effects of the LXR/PXR pathway which may open new perspectives in the treatment of demyelinating and neurodegenerative diseases. 相似文献
136.
137.
Amalia E. Yanni George Agrogiannis Tzortzis Nomikos Elisabeth Fragopoulou Alkisti Pantopoulou Smaragdi Antonopoulou Despoina Perrea 《Amino acids》2010,38(5):1323-1331
Previous studies have shown that dietary supplementation with l-aspartate and l-glutamate inhibits fatty streak initiation in cholesterol-fed rabbit. The present study investigates the role of dicarboxylic
amino acids on the progression of fatty streaks and the development of fatty liver disease, which were caused in New Zealand
White rabbits after a 0.5% w/w cholesterol diet for 7 weeks. A group of animals additionally received a combination of 12.5 mM l-aspartate and 12.5 mM l-glutamate per day through drinking water. Total cholesterol (TC), high-density lipoproteins cholesterol (HDLC), non-HDLC
and triacylglycerol (TAG) concentrations were measured in plasma. Serum gamma-glutamyl transferase (γ-GT), aspartate aminotransferase
(AST) and alanine aminotransferase (ALT) activities were also determined. At the end of dietary intervention, animals were
sacrificed. Aortic, hepatic and brain lesions were evaluated after staining with hematoxylin and eosin. Supplementation with
dicarboxylic amino acids inhibited the progression of aortic intima thickness (P < 0.05) and the development of liver lesions (P < 0.05). TC, non-HDLC and TAG were similarly increased in both cholesterol-fed groups. Serum γ-GT and AST activities elevated
during the study in all cholesterol-fed animals but the elevation of γ-GT was milder and significantly lower in rabbits treated
with l-aspartate and l-glutamate (P < 0.05). ALT activity was not affected by cholesterol feeding. In conclusion, oral supplementation with l-aspartate and l-glutamate inhibits the progression of atherogenesis and the development of fatty liver disease in the animal model of cholesterol-fed
rabbit. The beneficial effects of dicarboxylic amino acids reflect the limited elevation of serum γ-GT activity. 相似文献
138.
139.
Employing transgenic plants as alternative systems to the conventional Escherichia coli, Pichia pastoris or baculovirus hosts to produce recombinant allergens may offer the possibility of having available edible vaccines in the near future. In this study, two EF-hand-type Ca2+-binding allergens from olive pollen, Ole e 3 and Ole e 8, were produced in transgenic Arabidopsis thaliana plants. The corresponding cDNAs, under the control of the constitutive CaMV 35S promoter, were stably incorporated into the Arabidopsis genome and encoded recombinant proteins, AtOle e 3 and AtOle e 8, which exhibited the molecular properties (i.e. MS analyses and CD spectra) of their olive and/or E. coli counterparts. Calcium-binding assays, which were carried out to assess the biochemical activity of AtOle e 3 and AtOle e 8, gave positive results. In addition, their mobilities on SDS/PAGE were according to the conformational changes derived from their Ca2+-binding capability. The immunological behaviour of Arabidopsis-expressed proteins was equivalent to that of the natural- and/or E. coli-derived allergens, as shown by their ability to bind allergen-specific rabbit IgG antiserum and IgE from sensitized patients. These results indicate that transgenic plants constitute a valid alternative to obtain allergens with structural and immunological integrity not only for scaling up production, but also to develop new kind of vaccines for human utilization. 相似文献
140.
Vittoria Rago Laura Siciliano Saveria Aquila Amalia Carpino 《Reproductive biology and endocrinology : RB&E》2006,4(1):36-6