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1.
B. Culik D. Adelung M. Heise R. P. Wilson N. R. Coria H. J. Spairani 《Polar Biology》1989,9(6):365-370
Summary Heart rates and activity were monitored over 24 h in unrestrained, incubating Adélie penguins (Pygoscelis adeliae) exposed to natural conditions in the colony. Heart rate (HR in bpm) increased linearly with wind speed (w; range 0–19 m/s): HR = 85.8+1.35 w, but was unrelated (P>0.05) to temperature (-2.5°–6°C), humidity (37%–100%) cloud cover (0–8/8) and estimated solar radiation (0–12). Wind-induced heat loss was apparently compensated to a large degree by increased metabolic activity. Activity (A) measured as frequency of standing per hour, decreased linearly with temperature (t) and wind speed (w): A = 1.651–0.033w–0.090t. After correcting for meteorological influences, heart rate and bird activity showed no diurnal periodicity. When incubating, metabolism and activity of Adélie penguins appear to be mainly governed by climatic variations. 相似文献
2.
Ongay-Larios L Navarro-Olmos R Kawasaki L Velázquez-Zavala N Sánchez-Paredes E Torres-Quiroz F Coello G Coria R 《FEMS yeast research》2007,7(5):740-747
The Kluyveromyces lactis genes for sexual pheromones have been analyzed. The alpha-factor gene encodes a predicted polypeptide of 187 amino acid residues containing four tridecapeptide repeats (WSWITLRPGQPIF). A nucleotide blast search of the entire K. lactis genome sequence allowed the identification of the nonannotated putative a-pheromone gene that encodes a predicted protein of 33 residues containing one copy of the dodecapeptide a-factor (WIIPGFVWVPQC). The role of the K. lactis structural genes KlMFalpha1 and KlMFA1 in mating has been investigated by the construction of disruption mutations that totally eliminate gene functions. Mutants of both alleles showed sex-dependent sterility, indicating that these are single-copy genes and essential for mating. MATalpha, Klsst2 mutants, which, by analogy to Saccharomyces cerevisiae, are defective in Galpha-GTPase activity, showed increased sensitivity to synthetic alpha-factor and increased capacity to mate. Additionally, Klbar1 mutants (putatively defective in alpha-pheromone proteolysis) showed delay in mating but sensitivity to alpha-pheromone. From these results, it can be deduced that the K. lactis MATa cell produces the homolog of the S. cerevisiaealpha-pheromone, whereas the MATalpha cell produces the a-pheromone. 相似文献
3.
A. Negri G. A. Daneri F. Ceia R. Vieira Y. Cherel N. R. Coria A. Corbalán J. C. Xavier 《Polar Biology》2016,39(3):561-564
Weddell seals, Leptonychotes weddellii, are important apex predators in the food web of the Antarctic marine ecosystem. However, detailed information on their trophic relationships with cephalopods is scarce. Moreover, cephalopods play a key role in the marine environment, but knowledge of their feeding habits is limited by lack of data. Here, we have combined the use of this seal as a biological sampler together with measurements of the stable isotopic signature of the beaks of their cephalopod prey. Thus, the aims of the present study were: (1) to examine in detail the cephalopod portion of the diet of Weddell seals by means of scat analysis and (2) to assess the habitat use and trophic level of the different cephalopod prey taxa identified. From January to February 2009, a total of 48 faecal droppings were collected at Hope Bay, Antarctic Peninsula. Cephalopods were mainly represented by beaks (n = 83) which were identified to the lowest possible taxonomic level. Furthermore, subsamples of beaks were separated for further isotopic analysis. Relative abundance of stable isotopes of carbon (δ13C) and nitrogen (δ15N) was determined by continuous-flow isotope-ratio mass spectrometry. Cephalopods were represented uniquely by octopods of the subfamily Eledoninae. Pareledone turqueti was the dominant prey species followed by the papillated Pareledone species group and Adelieledone polymorpha. We conclude that Weddell seals preyed primarily on benthic prey resources. Furthermore, the relatively similar δ13C and δ15N values in beaks of the three octopod prey taxa suggest that these share the same type of habitat and occupy similar trophic level positions. 相似文献
4.
The breeding performance and population trends of Adélie penguins (Pygoscelis adeliae) was studied at Esperanza/Hope Bay, Antarctic Peninsula, by comparing an area with low levels of human disturbance (LLD)
and an area with high levels of human disturbance (HLD), close to an Argentine research station. From 1995/1996 to 2004/2005
(except for 1999/2000 and 2003/2004), the following population parameters were measured in both areas: (1) the number of breeding
pairs, (2) the number of chicks in creches and (3) the number of chicks produced by breeding pairs. Counts were made for 26
breeding groups situated in the LLD area and 63 breeding groups located in the HLD area. The number of chicks per breeding
pair was obtaobtained by following 100 marked nests in each area. All parameters were measured as described in the CCAMLR
Monitoring Program protocols. The magnitude and direction (increasing or decreasing) of the changes in breeding population
size and the number of chicks creched were similar in both areas. Overall, the number of breeding pairs decreased from 4,744
to 2,968 (37.4%) in the LLD area, and from 8,744 to 5,378 (38.6%) in the HLD area. The number of chicks fledged increased
from 3,808 to 4,065 (6.7%) in the LLD area, and decreased from 6,991 to 6,712 (4%) in the HLD area. Breeding success (chicks
fledged per marked nest) did not differ significantly between areas for most of the seasons compared. In 1996/1997, breeding
success was significantly higher in the HLD area. Our data suggest that environmental influences currently exert greater effects
than human disturbance on the penguin population at Esperanza Bay. 相似文献
5.
Coria C Almiron W Valladares G Carpinella C Ludueña F Defago M Palacios S 《Bioresource technology》2008,99(8):3066-3070
Aedes aegypti (L.) (Diptera: Culicidae), the main urban vector of dengue, has developed resistance to various insecticides, making its control increasingly difficult. We explored the effects of Argentine Melia azedarach L. (Meliaceae) fruit and senescent leaf extracts on Ae. aegypti larval development and survival, by rearing cohorts of first instar mosquitoes in water with different extract concentrations. We also analysed oviposition deterrent activity in choice tests with extract-treated ovitraps. The leaf extract showed a strong larvicide activity, with all larvae dying before pupation, and significantly delayed development time. It strongly inhibited oviposition by Ae. aegypti females. The fruit extract showed much weaker effects. This first report of highly effective larvicidal, growth regulating and oviposition deterrent activity of a senescent leaf extract of M. azedarach against Ae. aegypti, suggests that such extract could represent a promising tool in the management of this mosquito pest. 相似文献
6.
Fonseca Bárbara Medeiros Câmara Paulo Eduardo Aguiar Saraiva Ogaki Mayara Baptistucci Pinto Otávio Henrique Bezerra Lirio Juan Manuel Coria Silvia H. Vieira Rosemary Carvalho-Silva Micheline Amorim Eduardo Toledo Convey Peter Rosa Luiz Henrique 《Molecular biology reports》2022,49(1):179-188
Molecular Biology Reports - Vega Island is located off the eastern tip of the Antarctic Peninsula (Maritime Antarctica), in the Weddell Sea. In this study, we used metabarcoding to investigate... 相似文献
7.
Barrionuevo P Delpino MV Velásquez LN García Samartino C Coria LM Ibañez AE Rodríguez ME Cassataro J Giambartolomei GH 《Microbes and infection / Institut Pasteur》2011,13(3):239-250
The strategies that allow Brucella abortus to persist for years inside macrophages subverting host immune responses are not completely understood. Immunity against this bacterium relies on the capacity of IFN-γ to activate macrophages, endowing them with the ability to destroy intracellular bacteria. We report here that infection with B. abortus down-modulates the expression of the type I receptor for the Fc portion of IgG (FcγRI, CD64) and FcγRI-restricted phagocytosis regulated by IFN-γ in human monocytes/macrophages. Both phenomena were not dependent on bacterial viability, since they were also induced by heat-killed B. abortus (HKBA), suggesting that they were elicited by a structural bacterial component. Accordingly, a prototypical B. abortus lipoprotein (L-Omp19), but not its unlipidated form, inhibited both CD64 expression and FcγRI-restricted phagocytosis regulated by IFN-γ. Moreover, a synthetic lipohexapeptide that mimics the structure of the protein lipid moiety also inhibited CD64 expression, indicating that any Brucella lipoprotein could down-modulate CD64 expression and FcγRI-restricted phagocytosis. Pre-incubation of monocytes/macrophages with anti-TLR2 mAb blocked the inhibition of the CD64 expression mediated by HKBA and L-Omp19. These results, together with our previous observations establish that B. abortus utilizes its lipoproteins to inhibit the monocytes/macrophages activation mediated by IFN-γ and to subvert host immunonological responses. 相似文献
8.
9.
Smal C Aran M Lanzarotti E Papouchado M Foti M Marti MA Coria SH Vazquez SC Bercovich A Mac Cormack WP Turjanski AG Gallo M Cicero DO 《Biomolecular NMR assignments》2012,6(2):181-183
BA42 is a protein belonging to the psychrophilic bacteria Bizionia argentinensis sp. nov. Bioinformatics analysis showed that it presents significant sequence identity with a Pfam A family, DUF 477, found both in eukarya and eubacteria but of unknown function in all these organisms. Here, we report the NMR spectra assignment of this 145 amino acid protein. These data will allow performing NMR structural studies with the aim of using the three-dimensional structure as relevant information in order to determine the function of this family of proteins. 相似文献
10.
The effects of ice cover on diet and breeding chronology of Adélie (Pygoscelis adeliae) and chinstrap penguins (P. antarctica) were studied in the colonies located at Point Martin, South Orkney Islands. Reproductive success and diet parameters were measured as described in the CCAMLR Environmental Monitoring Program protocols. It was found that late pack-ice break-off in 1998 resulted in lower reproductive success than in 1999 for chinstrap penguins, while Adélie penguin parameters were rather insensitive. This species has shown to be able to cope with this environmental factor, as suggested by its circumpolar and more southerly range. Significant differences in stomach contents' weights and in the proportion of whole krill were found between ice-covered and open-sea periods within and between years. Foraging trips of both species became longer, resulting in underfeeding of chicks and nest desertion by chinstrap-penguin parents. Simultaneous analysis of reproductive parameters of both species and their diets have proven to be useful in discriminating between variation in reproductive success parameters due to prey accessibility and prey abundance. 相似文献