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101.
《Animal : an international journal of animal bioscience》2014,8(3):410-419
This study evaluated the strategy of supplementing oral micellized natural vitamin E (d-α-tocopherol) to either piglets and/or sows on α-tocopherol concentrations in piglets serum and tissues after weaning. One first experiment tested the influence of the vitamin E supplementation source (natural form in water v. the synthetic form in feed) and dose administered to piglets and/or sows on serum α-tocopherol concentration, α-tocopherol stereoisomer accumulation, antioxidant capacity and immune response of weaned piglets. A second experiment studied the effect of sow source and dose vitamin E supplementation on some of these parameters in piglets. Oral supplementation to sows with natural vitamin E as a micellized form (d-α-tocopherol) at the lowest dose produced a similar concentration of α-tocopherol in serum at days 2, 14 and 28 postpartum to those supplemented with threefold higher dose of the synthetic form in feed. At day 39 of age, neither piglet supplementation source nor dose significantly affected α-tocopherol accumulation in the serum, muscle, subcutaneous fat or liver. Those piglets from sows supplemented with the micellized alcohol form had higher RRR-α-tocopherol stereoisomers (P<0.001) and lower (P<0.001) RRS- RSS- and RSR-α-tocopherol, at day 39 of age than those from sows supplemented with the synthetic form. A predominant importance of sow over piglet vitamin E supplementation was observed on stereoisomer distribution in piglets. Low doses of oral natural vitamin E supplementation to sows or piglets did not increase the oxidative stress of piglets when compared with the use of the synthetic form in feed. Immunoglobulin levels in piglet serum at day 39 were not affected by natural vitamin E supplementation at low doses in drinking water of piglets or sows when compared with the synthetic form in feed. IgA tended to be higher (P=0.145) at day 39 in piglets supplemented with natural vitamin E when compared with those supplemented with the synthetic form. Low doses of oral micellized natural vitamin E supplementation to sows is an interesting feeding strategy, when compared with the use of high doses of the synthetic form in feed, because it results in similar α-tocopherol concentrations, allows a predominant –R stereoisomer distribution in piglets and also maintains their oxidative status in vivo. 相似文献
102.
《Molecular membrane biology》2013,30(1-2):27-42
The effect of unilamellar lipid vesicles composed of dioleoyl lecithin (DOL), egg yolk lecithin (EYL), 1:1 EYL:cholesterol (Chol), dipalmitoyl lecithin (DPL), and dimyristoyl lecithin (DML) on the mitogenic response in mouse lymphocytes was tested. Cortisone-resistant thymocytes were briefly treated with lipid vesicles and subsequently stimulated with concanavalin A (con A). All of the lipid vesicles induced an enhanced mitogenic response on day 3 as tested by [3H]TdR incorporation and by counting total cells. The order of enhanced [3H]TdR incorporation (?5.3 times the control) was DML>DPL>1:1 EYL:Chol>EYL?DOL> untreated control cells. These increases were paralleled by increased numbers of total cells. The response of spleen cells to a B-cell mitogen, bacterial lipopolysaccharide, was similarly enhanced by vesicle pretreatments in the same order. Vesicle treatments alone were not mitogenic.Pretreatment of cells with lipid vesicles modified lectin binding: DML and DPL increased the binding of [125I]con A by three to four times the control, whereas 1:1 EYL:Chol, EYL, or DOL had little or no effect. The binding of [125I]phytohemagglutinin-P (PHA-P) to vesicle-treated cells was indistinguishable from untreated cells. The lectin (con A; PHA-P)-induced agglutination of vesicle-treated cells was also modified by different lipid vesicles in the same order as the mitogenic response.Based on the results presented in the accompanying report [6], we find that the cell surface adsorption properties of the applied lipid vesicles correlate with their ability to enhance the mitogenic response, and that they modify agglutinability and lectin binding. These results are further discussed in terms of the possible alteration of membrane properties and subsequent cellular activity. 相似文献
103.
104.
105.
Carmen de Sena-Tomás Mónica Navarro-González Ursula Kües José Pérez-Martín 《Genetics》2013,195(1):47-57
The fungal fruiting body or mushroom is a multicellular structure essential for sexual reproduction. It is composed of dikaryotic cells that contain one haploid nucleus from each mating partner sharing the same cytoplasm without undergoing nuclear fusion. In the mushroom, the pileus bears the hymenium, a layer of cells that includes the specialized basidia in which nuclear fusion, meiosis, and sporulation occur. Coprinopsis cinerea is a well-known model fungus used to study developmental processes associated with the formation of the fruiting body. Here we describe that knocking down the expression of Atr1 and Chk1, two kinases shown to be involved in the response to DNA damage in a number of eukaryotic organisms, dramatically impairs the ability to develop fruiting bodies in C. cinerea, as well as other developmental decisions such as sclerotia formation. These developmental defects correlated with the impairment in silenced strains to sustain an appropriated dikaryotic cell cycle. Dikaryotic cells in which chk1 or atr1 genes were silenced displayed a higher level of asynchronous mitosis and as a consequence aberrant cells carrying an unbalanced dose of nuclei. Since fruiting body initiation is dependent on the balanced mating-type regulator doses present in the dikaryon, we believe that the observed developmental defects were a consequence of the impaired cell cycle in the dikaryon. Our results suggest a connection between the DNA damage response cascade, cell cycle regulation, and developmental processes in this fungus. 相似文献
106.
107.
Summary The effect of cropping systems of wheat-maize (WM), wheat-rice (WR), wheat-groundnut (WG), gram-bajra (GrB), potato-guara
(PGu), and raya-mash (RaMa) in combination with treatments of dummy (uncultivated area) and applied Zn 0.0 (Zn0), 2.8 (Zn1), 5.6 (Zn2) 11.2 (Zn3) kg/ha was studied on the transformation of labile Zn fractions: exchangeable (Exch.), adsorbed (TAd) [weakly (WAd), moderately
(MAd), strongly (SAd)], and organic matter (OM) in different layers of sandy loam soil. The added Zn stayed largely in the
0–30 cm layer and was associated with the WAd- and OM-Zn fractions. About 70% of the total labile Zn (PAv) remained in the
WAd- and OM-Zn, that is, 33 and 39% in 0–15 cm layer, and 33–39% and 31–36% in 16–150 cm layer. All the Zn fractions in 0–15
cm layer, and only of WAd in 16–30 cm layer, significantly increased with rates of Zn addition. These were also significantly
higher in Zn1–3 than Zn0 and dummy treatments because of the residual Zn.
Diverse effects of cropping systems on soil properties, residual Zn, and labile Zn fractions were found. The influence was
strong in 0–15 cm layer decreasing gradually with soil depth due largely to differences in Zn requirement, crop intake of
various Zn fractions and the cultural practices of the systems. All the crops and rotations appreciabilly responded to Zn
application. Uptake of Zn by crops markedly and successively increased with increasing rates of Zn application. The WR caused
a significant increase in soil organic matter whereas WR and WM in CaCO3. The WR, WM and GrB resulted in a decrease in pH while WG and GrB in CaCO3. The RaMa and PGu maintained much higher residual Zn than other systems. The systems which caused the maximum decrease in
Zn fractions were: cereal-cereal (WM) in Exch. legume-millet (GrB) in all the adsorbed, PAv and the Zn associated with CaCO3, vegetable-legume (PGu) also in MAd and SAd; and cereal-legume (WG) in OM and PAv. Hence GrB, WG and WM in that order will
cause the deficiency of Zn much earlier than the other systems due to greater use and or transformation of WAd- andOM-Zn.
Such effects were least under RaMa because it increased the WAd-, MAd- and OM-Zn. 相似文献
108.
ObjectiveLow levels of selenium (Se) and glutathione peroxidase (GSHPx), a key selenoenzyme, were documented in systemic inflammatory response syndrome (SIRS) and sepsis, both associated with high mortality. Se supplementation had mixed effects on outcome. We hypothesized that Se supplementation could have a different impact on biomarkers and 28-day mortality in patients with SIRS vs. sepsis.MethodsAdult patients with SIRS or sepsis were randomized to either high-dose (Se+, n = 75) or standard-dose (Se−, n = 75) Se supplementation. Plasma Se, whole blood GSHPx activity, C-reactive protein (CRP), procalcitonin (PCT), prealbumin, albumin and cholesterol levels were measured serially up to day 14.ResultsThere was no difference in mortality between Se− (24/75) vs. Se+ group (19/75; p = 0.367) or between SIRS and septic patients (8/26 vs. 35/124; p = 0.794). There was a trend to reduced mortality in SIRS patients in the Se+ vs. Se− group (p = 0.084). Plasma Se levels increased in the Se+ group only in patients with sepsis but not in patients with SIRS. Plasma Se levels correlated with GSHPx. In SIRS/Se+ group, Se correlated only with GSHPx. In SIRS/Se− group, Se correlated with cholesterol but not with other biomarkers. In sepsis patients, Se levels correlated with cholesterol, GSHPx and prealbumin. Cholesterol levels were higher in survivors in the Se− group.ConclusionsSe levels correlated with GSHPx activity and other nutritional biomarkers with significant differences between SIRS and sepsis groups. High-dose Se supplementation did not affect mortality but a strong trend to decreased mortality in SIRS patients warrants further studies in this population. 相似文献
109.
110.
The cell-surface expression patterns of major histocompatibility complex (MHC) class I, class II and heat-shock protein 72
(HSP72) molecules were measured on human lung (LX-1) and mammary (MX-1) carcinoma cells. No major differences were found in
the MHC cell-surface expression pattern of both cell lines. However, they differ significantly in their capacity to express
HSP72 on their cell surface. Under physiological conditions LX-1 cells express HSP72 molecules on more than 90% of the cells,
whereas MX-1 cells exhibit no significant HSP72 cell-surface expression (less than 5%). These expression patterns remained
stable in all further cell passages tested. The sensitivity to lysis mediated by an interleukin-2 (IL-2)-stimulated, adherent
natural killer (NK) cell population could be correlated with the amount of cell-surface-expressed HSP72 molecules. By antibody-blocking
studies, using HSP72-specific monoclonal antibody (mAb), a strong inhibition of lysis was only found with LX-1 cells but not
with MX-1 cells. In contrast to the cell-surface expression, the cytoplasmic amount of HSP72 in MX-1 cells was twice as high
compared to LX-1 cells under physiological conditions. After nonlethal heat-shock the rate of induction and the total cytoplasmic
amounts of HSP72 were comparable in both cell lines. The clonogenic cell viability of LX-1 cells after incubation at temperatures
ranging from 41°C to 44°C was significantly elevated compared to that of MX-1 cells. In conclusion we state the following:
(i) HSP72 cell-surface expression on human carcinoma cells is independent of the cytoplasmic amount of HSP72; (ii) the cell-surface
expression of HSP72 is associated with an increased sensitivity of tumour cells to lysis mediated by an IL-2-stimulated, adherent
NK cell population; (iii) thermoresistance is not related to the cytoplasmic HSP72 level but might be related to the amount
of HSP72 expressed on the cell surface.
Received: 20 June 1996 / Accepted: 25 September 1996 相似文献