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991.
Catecholamines (noradrenaline, NA; adrenaline, AD; dopamine, DA) influence the metabolic and cardiovascular responses to exercise.
However, changes in catecholamine metabolism during exercise are unclear. Plasma normetanephrine (NMET), metanephrine (MET)
and catecholamine responses to a laboratory-based model of games-type exercise were examined. Twelve healthy men completed
a resting control trial and a trial consisting of ten 6 s cycle ergometer sprints interspersed with 30 s recovery, in randomised
order. Resting and post-sprint venous blood samples were taken. Plasma NA and AD increased after each sprint but DA was unaltered.
Plasma nephrines increased significantly from sprint 4 onwards with peak NMET increasing 60% to 0.76 ± 0.19 nmol l−1 and MET 230% to 0.37 ± 0.16 nmol l−1 from resting values (P < 0.05). The results demonstrate increased catecholamine metabolism via elevated catechol-O-methyl transferase activity during intermittent sprinting. The results may aid regulation of the metabolic and cardiovascular
responses to exercise by maintaining tissue adrenoceptor sensitivity to circulating catecholamines. 相似文献
992.
Juneyoung Lee Hyun Joo Hong Jin-Kyoung Kim Jae-Sam Hwang Yangmee Kim Dong Gun Lee 《Molecules and cells》2009,28(5):473-477
Previously, the 9-mer analog peptides, 9Pbw2 and 9Pbw4, were designed based on a defensin-like peptide, protaetiamycine isolated
from Protaetia brevitarsis. In this study, antifungal effects of the analog peptides were investigated. The antifungal susceptibility testing exhibited
that 9Pbw4 contained more potent antifungal activities than 9Pbw2. A PI influx assay confirmed the effects of the analog peptides
and demonstrated that the peptides exerted their activity by a membrane-active mechanism, in an energy-independent manner.
As the noteworthy potency of 9Pbw4, the mechanism(s) of 9Pbw4 were further investigated. The membrane studies, using rhodamine-labeled
giant unilamellar vesicle (GUV) and fluorescein isothiocyanate (FITC)-dextran loaded liposome, suggested that the membrane-active
mechanism of 9Pbw4 could have originated from the poreforming action and the radii of pores was presumed to be anywhere from
1.8 nm to 3.3 nm. These results were confirmed by 3D-flow cytometric contour-plot analysis. The present study suggests a potential
of 9Pbw4 as a novel antifungal peptide. 相似文献
993.
This study investigated the enolization and racemization reactions of glucose and fructose on heating with amino acid enantiomers
and the formation of melanoidins as a result of the Maillard reaction. The study measured reducing sugars and L- and D- amino acids using HPLC as an index for the amount of enolization of the sugars and isomerization of the amino acids. Additionally,
the absorption of melanoidins was measured at different wavelengths (420, 450, 470, 490 nm); the UV–Vis spectra and the extinction
coefficient were determined for the formation of melanoidins. Melanoidins were, rather arbitrarily, defined by a high-molecular-weight
(HMW) if it was above a lower limit of 12.4 kDa, which was the nominal cut-off value in the dialysis system used. A remarkable
enolization reaction of the sugars was observed in the course of the Maillard reaction. Especially, in the Fru/D-Asn model system, the degree of sugar enolization was more than in the other model systems. All of the FDAA (1-fluoro-2,
4-dinitrophenyl-5-L-alanine amide) amino acids were separated by TLC. The racemization of the amino acids was higher in the fructose-amino acids
systems. Isomer formation was the highest in the Fru/D-Asn system. The L- and D- isomers showed different absorptions in the UV–Vis spectra, although these had similar shapes. The absorption of the melanoidins
formed from glucose was higher than that formed from fructose. In particular, the sugar–asparagine system showed different
characteristics according to the L- and D-isomers. The differences in the extinction coefficients of the melanoidins was significant (P < 0.05), except for the sugar–lysine system. 相似文献
994.
Hui Hu Ling Tao Yabin Wang Liying Chen Jihong Yang Hanzhong Wang 《Biotechnology letters》2009,31(11):1685-1693
The immunogenicity of SARS-CoV nucleocapsid DNA vaccine and the immunoregulatory activity of interleukin-2 (IL-2) were investigated.
DNA vaccine plasmids, pcDNA-N and pcDNA-IL2, were constructed and inoculated into BALB/c mice with or without pcDNA-IL2 by
intramuscular injection. Cellular and humoral immune responses were assessed by indirect ELISA, lymphocyte proliferation assays,
ELISPOT and FACS. The nucleocapsid DNA vaccine had good immunogenicity and can induce specific humoral and cellular immunity
in BALB/c mice, while IL-2 plays an immunoadjuvant role and enhances specific immune responses. This study provides a frame
of reference for the design of DNA vaccines against SARS-CoV. 相似文献
995.
996.
Modelling and predicting the potential habitat and future range expansion of invasive species can help managers to mitigate
the impact of such species. Because habitat suitability and the colonization process are key determinants of range expansion,
inferences drawn from invasion patterns should be based on both attributes. To predict the potential habitat and expansion
rate of the invasive tree Bischofia javanica on Hahajima Island, we used simultaneous models of habitat and dispersal to estimate the effect of environment and dispersal
from the source population on the current distribution. We compared the fit and the estimated magnitudes of the environment
and dispersal effects in the simultaneous models with those in habitat suitability and colonization kernel models. The values
of Akaike’s information criterion for the simultaneous models were better than those of the habitat suitability and colonization
kernel models, indicating that the current distribution of Bischofia was determined by both environment and dispersal. The simultaneous models predicted that the potential habitat of Bischofia would be larger than that predicted by the habitat suitability model. The potential habitat distribution and future invasion
predicted by the simultaneous models will contribute to the development of specific landscape-scale management plans to control
this invasive species. 相似文献
997.
998.
Kenji Takizawa Shinichiro Takahashi Norman P. A. Hüner Jun Minagawa 《Photosynthesis research》2009,99(3):195-203
Chlamydomonas raudensis Ettl UWO241, a natural variant of C. raudensis, is deficient in state transitions. Its habitat, the deepest layer of Lake Bonney in Antarctica, features low irradiance,
low temperature, and high salinity. Although psychrophily and low-light acclimation of this green alga has been described,
very little information is available on the effect of salinity. Here, we demonstrate that this psychrophile is halotolerant,
not halophilic, and it shows energy redistribution between photosystem I and II based on energy spillover under low-salt conditions.
Furthermore, we revealed that C. raudensis exhibits higher non-photochemical quenching in comparison with the mesophile Chlamydomonas reinhardtii, when grown with low-salt, which is due to the lower proton conductivity across the thylakoid membrane. Significance of the
C. raudensis UWO241 traits found in the low salinity culture are implicated with their natural habitats, including the high salinity and
extremely stable light environments. 相似文献
999.
1000.
Russell W. Jessup 《In vitro cellular & developmental biology. Plant》2009,45(3):282-290
The biofuel industry is rapidly growing because of increasing energy demand and diminishing petroleum reserves on a global
scale. A multitude of biomass resources have been investigated, with high-yielding, perennial feedstocks showing the greatest
potential for utilization as advanced biofuels. Government policy and economic drivers have promoted the development and commercialization
of biofuel feedstocks, conversion technologies, and supply chain logistics. Research and regulations have focused on the environmental
consequences of biofuels, greatly promoting systems that reduce greenhouse gas emissions and life-cycle impacts. Numerous
biofuel refineries using lignocellulosic feedstocks and biomass-based triglycerides are either in production or pre-commercial
development phases. Leading candidate energy crops have been identified, yet require additional efforts to realize their full
potential. Advanced biofuels, complementing conventional biofuels and other renewable energy sources such as wind and solar,
provide the means to substantially displace humanity’s reliance on petroleum-based energy. 相似文献