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221.
FGF21 attenuates lipolysis in human adipocytes - a possible link to improved insulin sensitivity 总被引:5,自引:0,他引:5
Arner P Pettersson A Mitchell PJ Dunbar JD Kharitonenkov A Rydén M 《FEBS letters》2008,582(12):1725-1730
Fibroblast growth factor 21 (FGF21) is active in murine adipocytes and has beneficial metabolic effects in animal models of type 2 diabetes mellitus. We assessed whether FGF21 influences lipolysis in human adipocytes and 3T3-L1 cells. FGF21 had no short-time effect (h) while a 3-day incubation with FGF21 attenuated hormone-stimulated lipolysis. FGF21 did not influence the mRNA expression of genes involved in regulating lipolysis, but significantly reduced the expression of the lipid droplet-associated phosphoprotein perilipin without affecting differentiation. Via reduced release of fatty acids into the circulation, the anti-lipolytic effect could be a mechanism through which FGF21 promotes insulin sensitivity in man. 相似文献
222.
'Image scoring' occurs when person A monitors the giving behaviour of person B towards person C. We tested for 'image scoring' in chimpanzees, bonobos, gorillas, and orangutans. Subjects passively observed two types of incident: (i) a 'nice' person gave grapes to a human beggar, and (ii) a 'nasty' person refused to give. The subject witnessed both incidents in succession (but was unable to obtain the grapes). Shortly after, the ape had an opportunity to approach one or both human actors (nice/nasty), both of whom were now sitting side-by-side holding grapes. However, neither human offered their grapes if approached. The subject's expectation of which human was more likely to offer food was measured by comparing the proportion of time that subjects spent near each person. Chimpanzees (n=17) spent significantly more time at the 'nice' window compared to 'nasty'. Also, preference for 'nasty' declined as trials progressed. Results for other apes were not significant. 相似文献
223.
Glucose metabolism via sorbitol pathway
has been implicated as a possible contributor to
the diabetes-related vascular changes. Nitric
oxide plays a major regulatory role in the vascular
dilatatory and constricted response. Also
it has been observed that diabetes causes vascular
changes leading to a decrease in nitric oxide
production. Additionally the accumulation of
sorbitol is also related to decreased nitric oxide
production. In the present study we investigated
the effect of normal and high glucose in the
presence or absence of both interleukin-1β or
an aldose reductase inhibitor on nitric oxide
production in rat aortic rings in vitro. Aortic
rings from normal male Wistar rats were dissected
and incubated for 24 to 48 hrs in the presence of glucose (5.0 mM or 20 mM) or
with or without interleukin (20 ng/ml). Other
rings were incubated in the above media with
the addition of the aldose reductase inhibitor
(WAY 121509). Interleukin-1β stimulated the
24 hr nitric oxide production and WAY 121509
decreased it under both low and high glucose
culture conditions. The interleukin-1β stimulation
was continued for 72 hrs. Nitric oxide production
in response to interleukin-1β was
greater at all time points when compared to the
incubation in media without interleukin-1β. In
media containing WAY 121509 the nitric oxide
production was decreased. Interleukin-1β stimulated
a greater increase in nitric oxide production
from aortic rings when incubated in high glucose when compared to normal glucose. The
inhibitory effect of aldose reductase inhibition
was reversible after 24 hr inhibition under both
normal and high glucose conditions. We conclude
that high glucose enhances the interleukin-
1β-induced nitric oxide synthesis and
the cytokine-induced nitric oxide production
was inhibited by aldose reductase inhibition.
Nitric oxide production may be linked to redox
influences caused by the polyol pathway. 相似文献
224.
225.
Faryad Sahneh Meghan A. Balk Marina Kisley Chi-kwan Chan Mercury Fox Brian Nord Eric Lyons Tyson Swetnam Daniela Huppenkothen Will Sutherland Ramona L. Walls Daven P. Quinn Tonantzin Tarin David LeBauer David Ribes Dunbar P. Birnie III Carol Lushbough Eric Carr Grey Nearing Jeremy Fischer Kevin Tyle Luis Carrasco Meagan Lang Peter W. Rose Richard R. Rushforth Samapriya Roy Thomas Matheson Tina Lee C. Titus Brown Tracy K. Teal Monica Pape Stephen Kobourov Nirav Merchant 《PLoS computational biology》2021,17(5)
226.
32P was incorporated into spectrin by incubation of fresh erythrocytes with 32Pi and glucose. The dimer and tetramer aggregates revealed only covalently-bound incorporation of phosphorus, while a higher aggregate of spectrin revealed both covalent and non-covalent incorporation. The specific activity of the covalently-bound phosphorus in all oligomers was identical, suggesting that the state of association is independent of phosphorylation. The non-covalent incorporation was shown to be due to the association of ATP with this higher aggregate. The nucleotide appears not to be bound directly to spectrin but rather to component 5 (erythrocyte actin) which is also found to be associated with this highly aggregated spectrin structure. 相似文献
227.
228.
Zhijian Li Robert L. Jarret Roy N. Pittman Kerry B. Dunbar James W. Demski 《Plant Cell, Tissue and Organ Culture》1993,34(1):83-90
Factors influencing in vitro growth rates of soybean embryos were investigated using embryos isolated in the cotyledon stage. The influence of these factors on final plant recovery from the embryos cultured was tested. Sucrose and glucose could serve as carbon sources with final plant yields being higher with sucrose than with glucose. A culture medium containing only KNO3 (25 mM) as the nitrogen source supported embryo growth. Adding glutamine (10 mM) to the medium containing KNO3 increased final plant recovery to 25%. Of several vitamin supplements tested a combination of pyridoxine-HCl, nicotinic acid and pantothenic acid (0.5; 1.0; 0.5 mg l-1) provided the best growth and plant yield. Of the plant growth regulators tested IAA, BAP and GA3 stimulated embryo growth and plant development when added to the medium at a low concentration (0.1 M). The optimal temperature for in vitro growth of cotyledon stage embryos was 27°C. Temperatures above 30°C caused growth retardation and reduced plant yield. A protocol for culturing soybean cotyledon stage embryos under conditions ensuring high plant recovery is proposed.Abbreviations IBA
indole-3-butyric acid
- GA3
gibberellic acid
- IAA
indole-3-acetic acid
- NAA
-naphthaleneacetic acid
- BAP
6-benzylaminopurine
- 2,4-D
2,4-dichlorophenoxyacetic acid 相似文献
229.
In this study we measured stable oxygen and carbon isotope ratios in the skeletons of massive reef-building corals (Porites lobata and Pavona gigantea) at four widespread locations in the tropical eastern Pacific, each with a unique marine climate. Annual variation in sea surface temperature (SST) varied from 5–7°C at upwelling sites (Gulf of Panamá and Galápagos Islands) to 2–3°C where upwelling was absent [Caño Isand (Costa Rica) and Gulf of Chiriquí (Panamá)]. Annual range in salinity was high in the gulfs of Panamá and Chiriquí (up to 15) and low at Cãno Island and Galápagos (2–3). We characterize the isotopic signatures of recent (15–40 y long records) El Niño/Southern Oscillation (ENSO) events, particularly the very severe 1982–1983 event. Subannual sampling at 1–2 month resolution reveals that the 18O signal at Caño Island records strong to very strong ENSOs. In the Gulf of Chiriquí, this signal is governed mainly (80%) by salinity and thus is a weak recorder of ENSO events: only the 1951–1952, 1957–1958 and 1972–1973 events appear as significant 18O anomalies over the period 1940–1984. In the Gulf of Panamá, high variation in both SST and salinity contribute to the 18O signal. ENSO events at this site are poorly recorded, probably due to ameliorating effects of cool upwelled water during the early stage of the ENSO event. The 18O record in Galápagos, however, shows a strong correlation with SST and accurately records all but the most severe 1982–1983 ENSO event. Thus, ENSOs are most clearly recorded at sites where salinity variation is minimal. At Caño only strong ENSOs are recorded while mild to strong events appear in the Galápagos record. Nowhere did the 18O signal accurately record the full range of temperatures that occurred during the 1982–1983 ENSO; however, a stress band on the coral skeleton was evident at all sites. By comparing the 18O records and skeletal features across sites it may be possible to identify the occurrence of strong to very severe ENSOs prior to instrumental records. The relationship between 18O and 13C was examined and found to be significantly positive and in phase (i.e., either depleted or enriched at the same time) at three of the four sites studied. Weak correlations at some sites may be explained by high variability in water column clarity leading to depleted 13C when waters are cool and surface isolation high. 相似文献
230.
Captive chimpanzees appear to anticipate the occurrence of conflict during feeding by grooming and being in proximity at increased
rates during the hour prior to feeding. The effect is more marked when food is clumped than when it is dispersed, suggesting
that the proximate cause is the anticipation of increased levels of competition. Chimpanzees did not choose high ranking individuals
more often as prefeed grooming partners; rather, they preferred to associate with their normal grooming partners (as reflected
in post-feed grooming preferences) and close kin. A strong correlation between prefeed association patterns and spatial proximity
during clumped feeding sessions suggests that their main concern is to be allowed to feed near individuals who are able to
monopolize food sources. 相似文献