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991.
A recurrent mutation in type II collagen gene causes Legg-Calvé-Perthes disease in a Japanese family
Miyamoto Y Matsuda T Kitoh H Haga N Ohashi H Nishimura G Ikegawa S 《Human genetics》2007,121(5):625-629
Legg-Calvé-Perthes disease (LCPD) is a common childhood hip disorder characterized by sequential stages of involvement of
the capital femoral epiphyses, including subchondral fracture, fragmentation, re-ossification and healing with residual deformity.
Most cases are sporadic, but familial cases have been described, with some families having multiple affected members. Genetic
factors have been implicated in the etiology of LCPD, but the causal gene has not been identified. We have located a missense
mutation (p.G1170S) in the type II collagen gene (COL2A1) in a Japanese family with an autosomal dominant hip disorder manifesting as LCPD and showing considerable intra-familial
phenotypic variation. This is the first report of a mutation in hereditary LCPD. COL2A1 mutations may be more common in LCPD patients than currently thought, particularly in familial and/or bilateral cases. 相似文献
992.
Jane M. Caffrey Michael C. Murrell Cathleen Wigand Richard McKinney 《Biogeochemistry》2007,82(3):251-264
Coastal marshes represent an important transitional zone between uplands and estuaries. One important function of marshes
is to assimilate nutrient inputs from uplands, thus providing a buffer for anthropogenic nutrient loads. We examined the effects
of nitrogen (N) and phosphorus (P) fertilization on biogeochemical and microbial processes during the summer growing season
in a Spartina patens (Aiton (Muhl.)) marsh in the Narragansett Bay National Estuarine Research Reserve on Prudence Island (RI). Quadruplicate
1 m2 plots were fertilized with N and P additions, N-only, P-only, or no additions. N-only addition significantly stimulated bacterial
production and increased pore water NH4+ and NO3− concentrations. Denitrification rates ranged from 0 to 8 mmol m−2 day−1. Fertilization had no apparent effect on soil oxygen consumption or denitrification measured in the summer in intact cores
due to high core-to-core variation. P fertilization led to increased pore water dissolved inorganic phosphorus (DIP) concentrations
and increased DIP release from soils. In contrast the control and N-only treatments had significant DIP uptake across the
soil-water interface. The results suggest that in the summer fertilization has no apparent effect on denitrification rates,
stimulates bacterial productivity, enhances pore water nutrient concentrations and alters some nutrient fluxes across the
marsh surface. 相似文献
993.
A major sensory organ for the detection of pheromones by animals is the vomeronasal organ (VNO). Although pheromones control
the behaviors of various species, the effect of pheromones on human behavior has been controversial because the VNO is not
functional in adults. However, recent genetic, biochemical, and electrophysiological data suggest that some pheromone-based
behaviors, including male sexual behavior in mice, are mediated through the main olfactory epithelium (MOE) and are coupled
to the type 3 adenylyl cyclase (AC3) and a cyclic nucleotide-gated (CNG) ion channel. These recent discoveries suggest the
provocative hypothesis that human pheromones may signal through the MOE. 相似文献
994.
The high incidence of thrombembolic diseases justifies the development of new antithrombotics. The search for a direct inhibitor has resulted in the synthesis of a considerable number of low molecular weight molecules that inhibit human α-thrombin potently. However, efforts to develop an orally active drug remain in progress as the most active inhibitors with a highly basic P1 moiety exhibit an unsatisfactory bioavailability profile. In our previous work we solved several X-ray structures of human α-thrombin in complexes with (1) novel bicyclic arginine mimetics attached to the glycylproline amide and pyridinone acetamide scaffold and (2) inhibitors with a novel aza scaffold and with charged or neutral P1 moieties. In the present contribution, we correlate the structures of the complex between these inhibitors and the protein with the calculated free energy of binding. The energy of solvation was calculated using the Poisson–Boltzmann approach. In particular, the requirements for successful recognition of an inhibitor at the protein’s active site pocket S1 are discussed.
Figure We report here on free energy of binding analysis of thrombin inhibitors with novel aza scaffold and novel bicyclic arginine mimetics in S1 pocket of thrombin 相似文献
995.
Presence and stability of an unusual phycoerythrin (PE) characteristically similar to R-PE are described in a terrestrial,
desiccation-tolerant cyanobacterium, Lyngbya arboricola. Extraction and purification of the PE by using acetone precipitation, gel filtration and ion-exchange chromatography resulted
in achieving a purity index (A560/A280) of up to 5.2. SDS-PAGE of the PE showed presence of 18 kDa, 20 kDa and 32 kDa bands corresponding to α, β and γ subunits
of R-PE without any other contaminating phycobiliproteins (PBPs). The absorption spectrum of the PE was distinguished by two
major peaks at 499 and 559 nm. The maximum fluorescence emission at room temperature was 578 nm. Spectroscopic and electrophoresis
characteristics of PE in the dry mats on storage at 25 ± 1°C over silica gel for 2 years remained almost unaffected. Quantitatively,
storage stability of the PE was in the order of dry mats > lyophilized > liquid state and the impact of temperature on loss
of PE was in the order of 25°C > −20°C > 4°C. The relevance of L. arboricola for production of stable unusual PE is discussed. 相似文献
996.
The objective of this investigation was to evaluate the frequency of chromosomal aberrations expressed as micronuclei (MN)
in 4–8 cell embryos generated by gamma-irradiation of female mice in the absence and in the presence of vitamin C. Female
NMRI mice were whole body exposed to 4 Gy gamma-irradiation after intraperitoneal (i.p.) injection of pregnant mare’s serum
gonadotrophin (PMSG) followed by injection of human chorionic gonadotrophin (HCG) and mating with non-irradiated NMRI male
mice. Pregnant animals were sacrificed and embryos flushed from the oviducts and fixed on slides. Cells were treated for MN
observation using standard method. To investigate the protective effect of vitamin C (ascorbic acid) on the frequency of MN,
100 mg/kg vitamin C was i.p. injected 1 h before irradiation. Results show that the frequency of MN generated in the embryos
of irradiated mother compared to those of control in the non-irradiated group increased dramatically (P < 0.001). Frequency of MN in embryos generated in irradiated female mice treated with vitamin C dramatically and statistically
decreased relative to the frequency observed in the irradiation only group (P < 0.001). This decrease returned the combined treatment group to a level that was not statistically different from the controls
(P > 0.05). Thus, irradiation of preovulatory stage oocytes leads to stable chromosome abnormalities expressed as micronuclei
in successive preimplantation embryos. Vitamin C reduces these clastogenic effects of radiation in preovulatory oocytes and
thus the reduced frequency of MN in embryos is probably due to its antioxidation and radical scavenging properties. 相似文献
997.
Marcus Clauss Hanspeter Steinmetz Ulrike Eulenberger Pete Ossent Robert Zingg Jürgen Hummel Jean-Michel Hatt 《European Journal of Wildlife Research》2007,53(1):68-72
The digestive tract of elephants is surprisingly short compared to other herbivorous mammals. However, measurements relating
the length of the intestine to the body mass of the respective individual are rare. In this study, we report such data for
an African elephant and an Asian elephant. Our data support the hypothesis that Asian elephants have a longer intestinal tract
than their African counterparts. These findings are in accord with the observation of longer retention times and higher digestion
coefficients in Asian as compared to African elephants. This difference between the species could be the reflection of slightly
different ecological niches, with Asian elephants adapted to a natural diet with a higher proportion of grass. 相似文献
998.
In order to better understand the various pathways of sucrose and starch catabolism in the anther of lily (Lilium hybrida var. “Enchantment”), invertase (EC 3.2.1.26) and amylase (EC 3.2.1.1, EC 3.2.1.2) activities were measured separately in
different fractions (anther wall, locular fluid and microspore/pollen) and correlated with the sugar content during anther
development. Our findings showed significant differences among the fractions analyzed, suggesting that the regulation of sucrose
and starch catabolism could follow distinct pathways in each fraction. Glucose and fructose amounts progressively decreased
from anther wall to fluid and from fluid to microspore/pollen. Thus, the developing pollen could act as a sink for the carbohydrates
that reach the anther. In this sense, cell wall-bound invertases seem to play a major role in soluble sugar partitioning in
the different fractions of the anther. Sucrose concentration was found to be substantially higher in the locular fluid than
in the other fractions, indicating a probable site for storage. On the other hand, the anther wall tissues could have a buffering
function, storing nutrient surplus in starch grains and thus regulating the availability of soluble sugars in the whole anther.
All these results proved the advantages of the experimental model proposed here, as well as its usefulness to investigate
sugar metabolism in Lilium anthers. 相似文献
999.
We develop a comprehensive biogeochemical framework for understanding and quantitatively evaluating metals bio-protection
in sulfidic microbial systems. We implement the biogeochemical framework in CCBATCH by expanding its chemical equilibrium
and biological sub-models for surface complexation and the formation of soluble and solid products, respectively. We apply
the expanded CCBATCH to understand the relative importance of the various key ligands of sulfidic systems in Zn detoxification.
Our biogeochemical analysis emphasizes the relative importance of sulfide over other microbial products in Zn detoxification,
because the sulfide yield is an order of magnitude higher than that of other microbial products, while its reactivity toward
metals also is highest. In particular, metal-titration simulations using the expanded CCBATCH in a batch mode illustrate how
sulfide detoxifies Zn, controlling its speciation as long as total sulfide is greater than added Zn. Only in the absence of
sulfide does complexation of Zn to biogenic organic ligands play a role in detoxification. Our biogeochemical analysis conveys
fundamental insight on the potential of the key ligands of sulfidic systems to effect Zn detoxification. Sulfide stands out
for its reactivity and prevalence in sulfidic systems. 相似文献
1000.
Michael J. W. Stokesbury Ronan Cosgrove Andre Boustany Daragh Browne Steven L. H. Teo Ronald K. O’Dor Barbara A. Block 《Hydrobiologia》2007,582(1):91-97
Pop-up satellite archival tags were attached to six Atlantic bluefin tuna (Thunnus thynnus) off the west coast of Ireland in autumn 2003 and 2004. The satellite tags measured pressure, ambient temperature and light
for the term of deployment. Radio pop-up satellite endpoint positions, light and sea surface temperature estimations of geolocation
indicate that two fish tagged minutes apart off the coast of County Donegal, migrated to the eastern and western Atlantic
Ocean over the following 8 months. The two fish were 5218 km apart at the termination of the experiment. After tagging in
September and popping up the following March and April, one fish had traveled to the western Atlantic while the other was
located in the waters off the southwest coast of Portugal. A third fish tagged off the coast of County Donegal in October
2004 moved into the Mediterranean Sea and was caught by a fishing vessel southeast of Malta on 11 June 2005. The results link
bluefin tuna feeding on European foraging grounds with known eastern breeding regions and western Atlantic waters. 相似文献