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Lorenzo Danilo Granados-Rivera Sergio Segundo González-Muñoz Juan Andrés Burgueño-Ferreira German David Mendoza-Martínez Carlos Manuel Arriaga-Jordán 《Archives of animal nutrition》2017,71(6):428-440
The objective of the study was to evaluate the effect of adding protected palmitic acid (PA) to the ration of grazing dairy cows supplemented with protected conjugated linoleic acid (CLA) on milk production, chemical composition and fat profile. Six cows were used, 3/4 American Swiss × Zebu, under a rotational grazing system in a mixed sward with Cynodon plectostachyus, Brachiaria decumbens and Brachiaria brizantha. Furthermore, each cow received daily 4 kg concentrates and 8 kg sorghum silage, which made up the basal diet. The cows were distributed into three two-cow groups. Three treatments were randomly assigned to the groups, using a cross design: (1) control (basal diet), (2) basal diet + CLA (50 g/d) and (3) basal diet + CLA (50 g/d) + PA (412 g/d). The following variables were evaluated: forage intake, milk production, protein, fat and lactose concentration in milk, and milk fatty acid (FA) profile. There were no differences in forage intake between treatments; however, there were differences in milk production, protein, fat and lactose yield and fat concentration, which increased significantly in group CLA + PA when compared with group CLA. The concentration of FA synthesised de novo was lower when PA was included in the diet. Adding PA to the diet of grazing cows mitigates the milk fat decline caused by including trans-10, cis-12 CLA in the diet. 相似文献
275.
Some aspects of the biology of Crematogaster pygmaea, a highly polydomous and polygynous ant, are more commonly found in monogynous species. One such characteristic is the high attractiveness of its queens. In this study, this attractiveness was assessed under varying experimental conditions to investigate the factors responsible for its expression and variation, and to identify the nature of queen attractiveness. It was shown (1) that C. pygmaea queens are highly attractive to the workers that cluster on and around them (retinue), (2) that the attractiveness of C. pygmaea queens is context-dependent, i.e., it increases with increasing degree of potential danger to the queen, (3) that the attractiveness signal of C. pygmaea queens is chemically based, and (4) that this signal is persistent and apparently not colony-specific. The proposed hypothesis is that the C. pygmaea queens constantly release an attractiveness signal that is “read” by the workers, in a dependent way linked to the context, and that the main function of this attractiveness is to protect queens. This protection would have a high adaptive value in the context of the social structure and the reproductive strategies in C. pygmaea. 相似文献
276.
Christian Peeters Chung-Chi Lin Yves Quinet Glauco Martins Segundo Johan Billen 《Arthropod Structure & Development》2013,42(3):257-264
Among social Hymenoptera, only some ant genera have more than one morphological kind of non-reproductive adults. Individuals that are bigger than ordinary workers can function for defence and/or food storage. In Crematogaster (Orthocrema) smithi from Arizona, a third caste exists in addition to winged queens and workers; it is intermediate in size, weight and morphology, and individuals lay many unfertilized eggs that are mostly eaten by larvae (Heinze et al., 1995, 1999). We studied another three species belonging to the subgenus Orthocrema: Crematogaster pygmaea from Brazil, Crematogaster biroi and Crematogaster schimmeri from Taiwan. Using scanning electron microscopy and ovarian dissections, we show that ‘intermediates’ are a patchwork of queen-like and worker-like traits, just as in C. smithi; importantly the combinations differ across species. ‘Intermediates’ are numerically few in the colonies, and in C. pygmaea they are produced seasonally. Using histology we confirmed the lack of a spermatheca, thus they are not ergatoid queens. Based on the similarity of their mosaic phenotypes with those in other ant lineages, we suggest that Orthocrema ‘intermediates’ are a soldier caste with a specialized trophic function. This soldier caste has been reported in other Orthocrema species from Madagascar, Guinea and Costa Rica, suggesting that it is widespread in this subgenus. 相似文献
277.
JP Reyes A Huanosta-Gutiérrez A López-Rodríguez A Martínez-Torres 《Channels (Austin, Tex.)》2015,9(2):88-95
We studied the effects of mutations of positively charged amino acid residues in the pore of X. tropicalis TMEM16A calcium-activated chloride channels: K613E, K628E, K630E; R646E and R761E. The activation and deactivation kinetics were not affected, and only K613E showed a lower current density. K628E and R761E affect anion selectivity without affecting Na+ permeation, whereas K613E, R646E and the double mutant K613E + R646E affect anion selectivity and permeability to Na+. Furthermore, altered blockade by the chloride channel blockers anthracene-9-carboxylic acid (A-9-C), 4, 4''-Diisothiocyano-2,2''-stilbenedisulfonic acid (DIDS) and T16inh-A01 was observed. These results suggest the existence of 2 binding sites for anions within the pore at electrical distances of 0.3 and 0.5. These sites are also relevant for anion permeation and blockade. 相似文献
278.
Ruben Queiro Segundo Gonzalez Carlos López-Larrea Mercedes Alperi Cristina Sarasqueta Jose Luis Riestra Javier Ballina 《Arthritis research & therapy》2007,8(6):R185
The aim of the present study was to evaluate the relative contribution of human leukocyte antigen (HLA)-C locus alleles in
determining the risk and the clinical expression of psoriatic arthritis (PsA). One hundred PsA patients were randomly selected
and grouped into three disease subsets: oligoarthritis (n = 40), polyarthritis (n = 25) and spondylitis (n = 35). The HLA-C locus profile of this cohort was studied by methods based on molecular biology and was compared with that
of 45 patients with psoriasis vulgaris and 177 healthy blood donors from the same ethnic origin. HLA-Cw*0602 was found associated
with both psoriasis (odds ratio (OR) 6.2; 95% confidence interval (CI) 3.1 to 12.5; p < 0.0001) and PsA (OR 6.2; 95% CI 3.6 to 10.8; p < 0.0001); however, this allele was equally found among the PsA subsets. HLA-Cw6-positive patients showed a longer psoriasis-arthritis
latency period (p = 0.012). HLA-Cw*0701 was found under-represented in PsA in comparison with controls (OR 0.5; 95% CI 0.3 to 0.9; p = 0.04), as was HLA-Cw*0802 (OR 0.3; 95% CI 0.08 to 1; p = 0.05). A positive association was found between psoriatic spondylitis and HLA-Cw*0702 (OR 5.0; 95% CI 1.4 to 25; p = 0.01). HLA-Cw*0602 seems to confer a general risk for psoriasis, but the presence of other HLA-C locus alleles may explain
an additional arthritogenic risk. HLA-C alleles may modulate some aspects of the clinical expression of PsA, but these findings
need confirmation. 相似文献