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111.
M Johnsson I Gustafson CJ Rubin AS Sahlqvist KB Jonsson S Kerje O Ekwall O Kämpe L Andersson P Jensen D Wright 《PLoS genetics》2012,8(8):e1002914
Domestication is one of the strongest forms of short-term, directional selection. Although selection is typically only exerted on one or a few target traits, domestication can lead to numerous changes in many seemingly unrelated phenotypes. It is unknown whether such correlated responses are due to pleiotropy or linkage between separate genetic architectures. Using three separate intercrosses between wild and domestic chickens, a locus affecting comb mass (a sexual ornament in the chicken) and several fitness traits (primarily medullary bone allocation and fecundity) was identified. This locus contains two tightly-linked genes, BMP2 and HAO1, which together produce the range of pleiotropic effects seen. This study demonstrates the importance of pleiotropy (or extremely close linkage) in domestication. The nature of this pleiotropy also provides insights into how this sexual ornament could be maintained in wild populations. 相似文献
112.
Mark J. Cameron Alyson A. Kelvin Alberto J. Leon Cheryl M. Cameron Longsi Ran Luoling Xu Yong-Kyu Chu Ali Danesh Yuan Fang Qianjun Li Austin Anderson Ronald C. Couch Stephane G. Paquette Ndingsa G. Fomukong Otfried Kistner Manfred Lauchart Thomas Rowe Kevin S. Harrod Colleen B. Jonsson David J. Kelvin 《PloS one》2012,7(9)
In terms of its highly pathogenic nature, there remains a significant need to further define the immune pathology of SARS-coronavirus (SARS-CoV) infection, as well as identify correlates of immunity to help develop vaccines for severe coronaviral infections. Here we use a SARS-CoV infection-reinfection ferret model and a functional genomics approach to gain insight into SARS immunopathogenesis and to identify correlates of immune protection during SARS-CoV-challenge in ferrets previously infected with SARS-CoV or immunized with a SARS virus vaccine. We identified gene expression signatures in the lungs of ferrets associated with primary immune responses to SARS-CoV infection and in ferrets that received an identical second inoculum. Acute SARS-CoV infection prompted coordinated innate immune responses that were dominated by antiviral IFN response gene (IRG) expression. Reinfected ferrets, however, lacked the integrated expression of IRGs that was prevalent during acute infection. The expression of specific IRGs was also absent upon challenge in ferrets immunized with an inactivated, Al(OH)3-adjuvanted whole virus SARS vaccine candidate that protected them against SARS-CoV infection in the lungs. Lack of IFN-mediated immune enhancement in infected ferrets that were previously inoculated with, or vaccinated against, SARS-CoV revealed 9 IRG correlates of protective immunity. This data provides insight into the molecular pathogenesis of SARS-CoV and SARS-like-CoV infections and is an important resource for the development of CoV antiviral therapeutics and vaccines. 相似文献
113.
Climate change is predicted to be dramatic at high latitudes. Still, climate impact on high latitude lake ecosystems is poorly understood. We studied 15 subarctic lakes located in a climate gradient comprising an air temperature difference of about 6°C. We show that lake water productivity varied by one order of magnitude along the temperature gradient. This variation was mainly caused by variations in the length of the ice‐free period and, more importantly, in the supply of organic carbon and inorganic nutrients, which followed differences in terrestrial vegetation cover along the gradient. The results imply that warming will have rapid effects on the productivity of high latitude lakes, by prolongation of ice‐free periods. However, a more pronounced consequence will be a delayed stimulation of the productivity following upon changes of the lakes terrestrial surroundings and subsequent increasing input of elements that stimulate the production of lake biota. 相似文献
114.
Microbiological Characterization of Wet Wheat Distillers' Grain, with Focus on Isolation of Lactobacilli with Potential as Probiotics 总被引:2,自引:2,他引:0
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Wet wheat distillers' grain (WWDG), a residue from ethanol fermentation, was examined from a microbiological perspective. After storage, WWDG was characterized by a high content of lactobacilli, nondetectable levels of other bacteria, occasional occurrence of yeasts, and a pH of about 3.6 and contained a mixture of lactic acid, acetic acid, and ethanol. The composition of lactobacilli in WWDG was simple, including primarily the species Lactobacillus amylolyticus, Lactobacillus panis, and Lactobacillus pontis, as determined by 16S rRNA gene sequencing. Since the use of WWDG as pig feed has indicated a health-promoting function, some relevant characteristics of three strains of each of these species were examined together with basal physiological parameters, such as carbohydrate utilization and growth temperature. Seven of the strains were isolated from WWDG, and two strains from pig feces were included for comparison. It was clear that all three species could grow at temperatures of 45 to 50°C, with L. amylolyticus being able to grow at temperatures as high as 54°C. This finding could be the explanation for the simple microflora of WWDG, where a low pH together with a high temperature during storage would select for these organisms. Some strains of L. panis and L. pontis showed prolonged survival at pH 2.5 in synthetic stomach juice and good growth in the presence of porcine bile salt. In addition, members of all three species were able to bind to immobilized mucus material in vitro. Especially the isolates from pig feces but, interestingly, some isolates from WWDG as well possessed properties that might be of importance for colonization of the gastrointestinal tracts of pigs. 相似文献
115.
Population dynamics and reproduction of Northern Lapwings Vanellus vanellus in a meadow restoration area in central Sweden 总被引:1,自引:0,他引:1
To investigate the effectiveness of a meadow restoration programme, we studied the relationships between population changes and environmental changes, return rates and hatching success in a population of Northern Lapwings Vanellus vanellus. The study was performed on mixed farmland (59 km2 ) in central Sweden, an area that underwent extensive meadow restoration between 1985 and 1994. The study included more than 2600 nests, supplemented with observations of 127 individually colour-ringed Northern Lapwings. The breeding population varied (2.7–5.3 pairs/km2 ), but showed no significant trend with time. The population increased in years with high spring flooding levels. Population size was unrelated to demographic factors (e.g. hatching success the previous year (14–50%), and return rate). Lapwings moved considerably between years and their nest site fidelity was unrelated to previous hatching success or other factors, suggesting that changes in habitat quality and migration between populations were important in regulating population size. Recent extensive meadow restoration did not seem to aid the Northern Lapwing population; birds continued nesting on tillage even though most nests were destroyed by farming activities. A relatively high relaying frequency improved hatching success, which was still lowest in the most preferred habitats (spring sown crops, total hatching success c. 30%). The few Northern Lapwings breeding in the least preferred habitats (meadows and cultivated grassland) had a better hatching success (> 70% total hatching success), suggesting that habitat selection was not determined by hatching success. From these results, recommendations are made for the management of Northern Lapwing (and associated species) populations on farmland. 相似文献
116.
Mattias Jonsson 《Ecological Entomology》2003,28(2):159-167
Abstract. 1. Life-history traits associated with colonisation ability were compared in the threatened tenebrionid beetle Oplocephala haemorrhoidalis and its common relative Bolitophagus reticulatus . Both species feed and breed exclusively in fruiting bodies of the wood-decaying fungus Fomes fomentarius .
2. The presence and status of flight wings, flight muscles, and mature eggs were determined by dissection. Flight willingness was studied in a field experiment, and flight duration in a flight-mill experiment.
3. Females of O. haemorrhoidalis had fewer but larger eggs in their abdomen than B. reticulatus females.
4. All beetles of both species had fully developed flight wings but a larger proportion of B. reticulatus than O. haemorrhoidalis had developed flight muscles.
5. Bolitophagus reticulatus was more willing to take off than O. haemorrhoidalis , however both species, especially O. haemorrhoidalis , were powerful fliers, with many individuals being able to fly several kilometres. Oplocephala haemorrhoidalis tended to make few flights of long duration whereas B. reticulatus made several, but mostly shorter, flights.
6. The results indicate that B. reticulatus has a suite of life-history traits that makes it better adapted than O. haemorrhoidalis to exploit the scattered trees with fruiting bodies present in managed forests. This may explain why O. haemorrhoidalis is restricted primarily to sites with a high density of suitable substrates that have been available continuously for a long time. 相似文献
2. The presence and status of flight wings, flight muscles, and mature eggs were determined by dissection. Flight willingness was studied in a field experiment, and flight duration in a flight-mill experiment.
3. Females of O. haemorrhoidalis had fewer but larger eggs in their abdomen than B. reticulatus females.
4. All beetles of both species had fully developed flight wings but a larger proportion of B. reticulatus than O. haemorrhoidalis had developed flight muscles.
5. Bolitophagus reticulatus was more willing to take off than O. haemorrhoidalis , however both species, especially O. haemorrhoidalis , were powerful fliers, with many individuals being able to fly several kilometres. Oplocephala haemorrhoidalis tended to make few flights of long duration whereas B. reticulatus made several, but mostly shorter, flights.
6. The results indicate that B. reticulatus has a suite of life-history traits that makes it better adapted than O. haemorrhoidalis to exploit the scattered trees with fruiting bodies present in managed forests. This may explain why O. haemorrhoidalis is restricted primarily to sites with a high density of suitable substrates that have been available continuously for a long time. 相似文献
117.
Atlantic salmon straying from the River Imsa 总被引:5,自引:1,他引:4
Mean estimated straying rate for Atlantic salmon Salmo salar L. leaving the River Imsa as smolts during 1976–1999 was 15% for hatchery fish and 6% for wild conspecifics. Hatchery Atlantic salmon selected for production traits during four or more generations strayed >50%. The straying rate was higher for Atlantic salmon staying 2 rather than 1 year at sea before attaining maturity. For spawning, 96% of the strays entered streams within 420 km from the River Imsa, and c . 80% entered streams within 60 km of the mouth of the River Imsa, whether the fish were wild or hatchery released. Within the 60 km zone, the number of strays caught in a river increased with the Atlantic salmon catch in that river, but there was no significant relationship between straying rate and water discharge or distance from the river to the River Imsa. The observed straying rate of hatchery Atlantic salmon decreased with increasing number of fish entering the River Imsa. Sexual maturation as parr did not influence the tendency to stray. The results suggest that the establishment of temporary zones, free of fish farms, outside important Atlantic salmon rivers by the fisheries authorities in Norway should be large, whole fjords, to be effective. 相似文献
118.
Interleukin-1alpha (IL-1alpha) is constitutively produced by Sertoli cells in adult rat testes. We demonstrate here that adult rats initiate expression of IL-1alpha and IL-1beta in testicular macrophages and decrease plasma testosterone by 60%, 2 h after administration of endotoxin. The macrophage activation was accompanied by downregulation of IL-1alpha mRNA expression in Sertoli cells. Despite increased tissue concentrations of IL-1alpha and IL-1beta immunoreactive protein, the level of bioactive IL-1 in the testis remained unchanged. Testes from prepubertal rats responded similarly to endotoxin, but lacked constitutive expression of IL-1alpha. We conclude that endotoxin-induced inflammation involves the testis by local macrophage activation and cytokine secretion. The paracrine mechanisms regulating IL-1 bioactivity in the testis are unknown but may represent a means to protect germ cells from noxious effects of inflammation. 相似文献
119.
Pierre P. Massion Yong Zou Hasmet Uner Porntip Kiatsimkul Holly J. Wolf Anna E. Baron Tim Byers Steinn Jonsson Stephen Lam Fred R. Hirsch York E. Miller Wilbur A. Franklin Marileila Varella-Garcia 《PloS one》2009,4(6)
Lung carcinoma development is accompanied by field changes that may have diagnostic significance. We have previously shown the importance of chromosomal aneusomy in lung cancer progression. Here, we tested whether genomic gains in six specific loci, TP63 on 3q28, EGFR on 7p12, MYC on 8q24, 5p15.2, and centromeric regions for chromosomes 3 (CEP3) and 6 (CEP6), may provide further value in the prediction of lung cancer. Bronchial biopsy specimens were obtained by LIFE bronchoscopy from 70 subjects (27 with prevalent lung cancers and 43 individuals without lung cancer). Twenty six biopsies were read as moderate dysplasia, 21 as severe dysplasia and 23 as carcinoma in situ (CIS). Four-micron paraffin sections were submitted to a 4-target FISH assay (LAVysion, Abbott Molecular) and reprobed for TP63 and CEP 3 sequences. Spot counts were obtained in 30–50 nuclei per specimen for each probe. Increased gene copy number in 4 of the 6 probes was associated with increased risk of being diagnosed with lung cancer both in unadjusted analyses (odds ratio = 11, p<0.05) and adjusted for histology grade (odds ratio = 17, p<0.05). The most informative 4 probes were TP63, MYC, CEP3 and CEP6. The combination of these 4 probes offered a sensitivity of 82% for lung cancer and a specificity of 58%. These results indicate that specific cytogenetic alterations present in preinvasive lung lesions are closely associated with the diagnosis of lung cancer and may therefore have value in assessing lung cancer risk. 相似文献
120.