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91.
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93.
Light, fluorescence and electron microscopical analysis of therooted freshwater plantRanunculus trichophyllusrevealed a peculiaranatomical feature. In addition to the true endodermis encirclingthe root stele, endodermis-like sheaths occurred around eachvascular bundle of the leaf segments and of the eustelic stemwith its large central cavity, which assumed an anatomical featureresembling that of some pteridophyte stems. These impermeablesheaths, whose cells differentiate suberized walls, can playa major role in hampering the apoplastic leakage of the pressurizedwater solution which flows throughout the plant in xylem vesselsand contains the mineral nutrients taken up by the roots fromthe sediment. Moreover, these sheaths can function in preventingflooding of the aerenchymatic cavities of the submerged organs.In this way the endodermis-like sheaths preserve the correctcirculation of gas and nutrient solution through the entireorganism and assume great significance as a structural mechanismevolved by this species to survive and grow underwater.Copyright1999 Annals of Botany Company. Ranunculus trichophyllus,freshwater macrophyte, submerged angiosperm, anatomy, endodermis, endodermis-like sheaths, light microscopy, fluorescence microscopy. 相似文献
94.
Paolo Ruzza Arianna Donella-Deana Andrea Calderan Giuseppe Zanotti Luca Cesaro Lorenzo A. Pinna Gianfranco Borin 《Journal of peptide science》1998,4(1):33-45
Two Tyr residues are supposed to play a crucial role in the regulation of protein tyrosine kinases of the Src family. Autophosphorylation of Src Tyr416 correlates with enzyme activation, while phosphorylation of C-terminal Tyr527 by Csk gives rise to inactive forms of Src kinases. It has previously been demonstrated that the Src-like tyrosine kinase expressed by the oncogenelyndisplays a particularly high affinity (Km20 μm ) toward the dimeric linear and cyclic derivatives of the heptapeptide H-Glu-Asp-Asn-Glu-Tyr-Thr-Ala-OH which reproduces the main autophosphorylation site of most of the Src enzymes. Under the experimental conditions used only one Tyr residue of the dimeric sequence can be phosphorylated [P. Ruzza, A. Calderan, B.Filippi, B. Biondi, A. Donella Deana, L. Cesaro, L. A. Pinna & G. Borin (1995) Int. J. Peptide Protein Res. 45, 529–539]. The present study addresses the problem of the efficiency displayed by Lyn towards the two Tyr residues located at positions 5 and 12 of the dimeric peptide. To this purpose, two tetradecapeptides were synthesized by the classical solution method, each containing one of the two Tyr residues alternatively replaced by Phe, and the corresponding univocal cyclic form. A possible correlation between the different structural properties induced by the modifications of the native sequence and the ability of the peptides to act as Lyn substrates was noted. The kinetic data obtained indicate that Lyn phosphorylates the residues located at different positions in the two linear analogues differently. In particular, while the Tyr5, Phe12 derivative presents aKmvalue similar to those obtained for the dimeric linear and cyclic unmodified analogues, theKmvalue of the Phe5, Tyr12 derivative is two-fold higher than those found for the above-mentioned peptides. Moreover, as previously reported for the linear and cyclic dimeric forms of the native sequence, in the mono-tyrosine containing series of dimers the still conformationally flexible cyclic derivative shows a phosphorylation efficiency two-fold higher than those found for the linear derivatives. © 1998 European Peptide Society and John Wiley & Sons, Ltd. 相似文献
95.
G. Fenu G. Bacchetta V. Giacanelli D. Gargano C. Montagnani S. Orsenigo D. Cogoni G. Rossi F. Conti A. Santangelo M. S. Pinna F. Bartolucci G. Domina G. Oriolo C. Blasi P. Genovesi T. Abeli S. Ercole 《Biodiversity and Conservation》2017,26(2):309-328
Habitat Directive is the core strategy of nature conservation in Europe aiming at halting biodiversity loss. In this study the results of the third Italian assessment regarding the conservation status (CS) of plants listed in the Habitat Directive (Flora of community interest—FCI) was presented. Data was collected from several sources related to plant distribution, population data, habitats and pressures. Following the official European procedure, all parameters were evaluated and combined to give the CS of each taxon in each biogeographical region of presence. A comparison between the recent Italian IUCN and Reporting assessments was performed in order to evaluate the consistency between these two assessments. The official EU checklist comprises 113 Italian plant taxa, 107 of which were examined in this study. Our results showed a critical situation with only 34% of favourable CS, while 50% were unfavourable (40% inadequate plus 10% bad) and 16% unknown, in particular in the Mediterranean bioregion, where the unfavourable assessments reach the 65%. The results of the Report were consistent with those of the IUCN assessment, in which 41.9% of plants were threatened with extinction. This report highlighted some benefits and criticisms at national level, but it may have a wider significance. Although a general advance of knowledge, a great effort is needed to reach the Habitats Directive goals. Despite the limited resources, monitoring activities needs to be improved in order to close information gaps for several plants. A positive outcome was the development of a specific national project funded by the Italian Ministry of Environment, with the ambitious target to set future monitoring activities for FCI and optimize monitoring efforts. 相似文献
96.
Carlo Pinna Carla Giuditta Vecchiato Vladimiro Cardenia Maria Teresa Rodriguez-Estrada Claudio Stefanelli Monica Grandi 《Archives of animal nutrition》2017,71(5):395-412
The in vitro effect of a Yucca schidigera extract (YSE) and tannins from chestnut wood on composition and metabolic activity of canine and feline faecal microbiota was evaluated. Four treatments were carried out: control diet, chestnut tannins (CT), YSE and CT + YSE. The YSE was added to canine and feline faecal cultures at 0.1 g/l, while CT were added at 0.3 g/l for a 24-h incubation. A total of 130 volatile compounds were detected by means of headspace-solid phase microextraction gas-chromatography/mass spectrometry analyses. Several changes in the metabolite profiles of fermentation fluids were found, including a decrease of alcohols (?19%) and esters (?42%) in feline and canine inoculum, respectively, which was due to the antibacterial properties of tannins. In canine inoculum, after 6 h, YSE + CT caused lower cadaverine concentrations (?37%), while ammonia (?4%) and quinolone (?27%) were reduced by addition of CT. After 24 h, the presence of CT resulted in a decrease of sulphur compounds, such as dimethyl sulphide (?69%) and dimethyl disulphide (?20%). In feline faecal cultures, after 6 h, CT lowered the amount of indole (?48%), whereas YSE tended to decrease trimethylamine levels (?16%). Both in canine and feline inoculum, addition of CT and, to a minor extent, YSE affected volatile fatty acids patterns. In canine faecal cultures, CT exerted a marginal inhibitory effect on Escherichia coli population (?0.45 log 10 numbers of DNA copies/ml), while enterococci were increased (+2.06 log 10 numbers of DNA copies/ml) by YSE. The results from the present study show that YSE and tannins from chestnut wood exert different effects on the composition and metabolism of canine and feline faecal microbiota. In particular, the supplementation of YSE and tannins to diets for dogs and cats may be beneficial due to the reduction of the presence of some potentially toxic volatile metabolites in the animals’ intestine. 相似文献
97.
Equine and Canine Anaplasma phagocytophilum Strains Isolated on the Island of Sardinia (Italy) Are Phylogenetically Related to Pathogenic Strains from the United States 下载免费PDF全文
Alberto Alberti Rosanna Zobba Bernardo Chessa Maria Filippa Addis Olivier Sparagano Maria Luisa Pinna Parpaglia Tiziana Cubeddu Gianpaolo Pintori Marco Pittau 《Applied microbiology》2005,71(10):6418-6422
The presence of Anaplasma phagocytophilum, a tick-transmitted zoonotic pathogen, was investigated in Sardinia using a molecular approach. Phylogenetic analysis revealed that Sardinian strains are genetically distinct from the two lineages previously described in Europe and are closely related to strains isolated in different areas of the United States. 相似文献
98.
Murineddu G Murruzzu C Curzu MM Chelucci G Gotti C Gaimarri A Legnani L Toma L Pinna GA 《Bioorganic & medicinal chemistry letters》2008,18(23):6147-6150
Alpha series of novel 3,6-diazabicyclo[3.1.1]heptane derivatives 4a-f was synthesized and their affinity and selectivity towards alpha4beta2 and alpha7 nAChR subtypes were evaluated. The results of the current study revealed a number of compounds (4a, 4b and 4c) having a very high affinity for alpha4beta2 (K(i) at alpha4beta2 ranging from 0.023 to 0.056 nM) versus alpha7 nAChR subtypes; among these compounds, the 3-(6-bromopyridin-3-yl)-3,6-diazabicyclo[3.1.1]heptane 4c was found to be the most alpha7alpha4beta2 selective term in receptor binding assays (alpha7alpha4beta2=1295). Moreover, compound 4d also had high affinity for the alpha4beta2 nAChR subtype (K(i)=1.2 nM) with considerably high selectivity (alpha7/alpha4beta2=23300). 相似文献
99.
Samuel Pinna Hirondelle Varady-Szabo Patrick Boivin Eric Lucas 《Journal of Insect Conservation》2009,13(4):387-397
Urban habitats harbour considerable biological diversity. Ecologists have developed methods to select which habitats should
be conserved. The Ecological value, a method based on vegetation, has been created for the urban habitats of Montreal (Quebec, Canada). The main objective of
our study was to determine if this method was relevant to assess carabid diversity of Mount Royal Park. This index is calculated
using five criteria: uniqueness, representativeness, degree of succession, richness and rarity of the flora, each of which
can influence communities of insects. Ground beetles (Coleoptera: Carabidae) were selected because of their success as biological
indicators. Despite sampling difficulties, our results demonstrate clearly that the Ecological value method does not represent the high carabid richness of urban open habitats (tall grasses) and their specialised native carabid
species. Within forests we found nonetheless that the ecological value index has a significant positive relationship with
native carabid abundance. Moreover, maturity and structure of urban forests were positively correlated with carabid abundance
and richness. Some urban vegetation characteristics have been shown to influence entomological diversity, but the relevance
of using a global floral index to encompass the carabid community seems limited. 相似文献
100.
JESÚS MANZANILLA ENRIQUE LA MARCA MARIO GARCÍA-PARÍS 《Biological journal of the Linnean Society. Linnean Society of London》2009,97(1):185-199
We used partial sequences of mitochondrial 16S and cytochrome oxidase I genes to perform a phylogenetic study of collared frogs (Anura: Aromobatidae: Mannophryne ), a genus endemic to Venezuela and the islands of Trinidad and Tobago. We analysed 1.2 kb from 13 of the 15 described species of Mannophryne . Maximum parsimony, maximum likelihood and Bayesian analyses support the monophyly of Mannophryne . Mannophryne consists of three deeply differentiated clades that split from each other in a relatively short period of time. The diversification of Mannophryne occurred well before the glacial-interglacial periods of the Quaternary. Our data support the taxonomic validity of M. olmonae , a species endemic to Tobago Island. Mannophryne olmonae is more closely related to the continental species Mannophryne riveroi than to the Trinidad island endemic Mannophryne trinitatis . As in most tropical clades of frogs, molecular evidence indicates that species richness in Mannophryne is largely underestimated and, consequently, current priorities for conservation are inadequate. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 185–199. 相似文献