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71.
Amanda Arantes Perez Débora Balabram Rafael Malagoli Rocha átila da Silva Souza Helenice Gobbi 《The journal of histochemistry and cytochemistry》2015,63(6):408-416
We assessed the co-expression of cell cycle-related biomarkers in a series of 121 consecutive cases of high-grade ductal carcinoma in situ (DCIS), pure or associated with invasive carcinoma, and their associations with the different immunoprofiles of DCIS. Cases were identified from the histopathology files of the Breast Pathology Laboratory, Federal University of Minas Gerais, Brazil, from 2003 to 2008. The expression of estrogen receptor, progesterone receptor, HER2 overexpression, cytokeratin 5, epidermal growth factor receptor 1, cyclooxygenase-2, p16 and Ki67 were assessed. Tumors were placed into five subgroups according to their immunohistochemical profile: luminal A, luminal B, HER2, basal-like and “not classified”. We found that the basal phenotype was associated with a higher frequency of p16-positive cases (83%) and the luminal A phenotype showed a higher frequency of p16-negative cases (93%; p=0.000). The association of biomarkers p16+/Ki67+/COX2+ was expressed in 02/06 cases (33.3%) of the basal phenotype but in only 01/70 cases (1.4%) of the luminal A phenotype (p=0.01). The co-expression of p16+/Ki67+/COX2- was associated with a basal phenotype (p=0.004). P16 expression, p16+/Ki67+/COX2+ and p16+/Ki67+/COX2- co-expression showed significant associations with the basal phenotype and these profiles could be used to guide more aggressive treatment strategies in patients with high-grade DCIS. 相似文献
72.
Eliane Ceccon José I. Barrera‐Cataño James Aronson Cristina Martínez‐Garza 《Restoration Ecology》2015,23(4):331-336
Almost half of Mexican territory has been classified as environmentally degraded. The main response for the last 60 years has been reforestation to combat soil erosion and loss of forest cover, mostly carried out on private lands where negotiations with local stakeholders were critical. Despite four legal instruments referring to ecological restoration, no specific instrument that defines basic concepts, criteria and standards, required actions, or regulations to implement and evaluate ecological restoration exists. The Ministry of the Environment and Natural Resources is now solely in charge of restoration and only recently have external scientists been invited to be part of the process. Following important national and international events in Latin America and the Caribbean region, the First Mexican Symposium on Ecological Restoration was held in November, 2014. This historic event was the first action undertaken in Mexico to meet Objective 3 of the Global Strategy of Plant Conservation, coordinated in Mexico by the National Council for the Use and Knowledge of Biodiversity. Although mangrove ecosystems are the most endangered ecosystem type in Mexico, they were not well represented at the symposium. In contrast, several other ecosystem types, such as tropical dry forest and islands, have received increased attention. Overall, while the Symposium and above‐cited policy initiatives are important steps, Mexico needs to increase its institutional capacities and social organization of the rural sector with regard to ecological restoration. Better integration of social and natural scientists and increased participation of Mexico internationally is also needed. 相似文献
73.
To promote understanding of fish population dynamics in tropical river-floodplains, we have synthesized existing information
by developing a largely empirical population model for arapaima (Arapaima sp.). Arapaima are characterized by very large bodies, relatively late sexual maturity, small clutches, and large parental
investment per offspring, and their populations are overexploited and even declining due to overfishing. We used unparalleled
time series data on growth, reproduction, catch-at-age, and size-class abundance estimates for a population that has increased
several-fold and undergone drastic changes in fishing practices in the Amazon, Brazil. Model population numbers were close
to observed numbers, with generally low mean absolute percentage errors for juveniles (16%), adults (30%), and catch (18%).
In using the model to test ecological hypotheses and to investigate management strategies, we found the following: (1) Annual
recruitment is directly and positively related to spawner abundance, and it appears to be density-compensatory following a
Beverton–Holt relation (R
2 = 0.85). (2) Fishing-selectivity of arapaima caused by use of harpoons and gillnets can lower yield potentials dramatically
through removal of the faster-growing individuals of the population. That is in part because fewer individuals live long enough
to reproduce and survivors take longer to reach reproductive age. (3) Arapaima populations can sustain annual catches of up
to 25% of the number of adults in the population the previous year if minimum size (1.5 m) and closed season (December–May)
limits are met. (4) When 25% of the number of adults in the population the previous year is harvested under a 1.6 m minimum
size limit of catch, catches are slightly smaller but abundance of adults in the population is considerably greater than under
a 1.5 m limit. These findings can be used in ongoing management initiatives, but caution is needed because of present biological
and ecological uncertainty about these fishes. 相似文献
74.
Ostrosky EA Marcondes EM Nishikawa Sde O Lopes PS Varca GH Pinto Tde J Consiglieri TV Baby AR Velasco MV Kaneko TM 《AAPS PharmSciTech》2011,12(2):732-737
Even though the synthetic preservatives may offer a high antimicrobial efficacy, they are commonly related to adverse reactions
and regarded as having potentially harmful effects caused by chronic consumption. The development of natural preservatives
provides a way of reducing the amount of synthetic preservatives normally used in pharmaceutical and cosmetic preparations.
In addition, these agents have less toxic effects and represent a possible natural and safer alternative of the preservatives.
The purpose of this research was to evaluate the Rubus rosaefolius Smith extract efficiency as a natural preservative in base formulations. Of the extract, 0.2% (w/w) was assayed for its effectiveness of antimicrobial protection in two different base formulations (emulsion and gel). The
microbial challenge test was performed following the standard procedures proposed by The United States Pharmacopoeia 33nd,
European Pharmacopoeia 6th, Japanese Pharmacopoeia 15th, and the Cosmetics, Toiletries, and Fragrance Association using standardized
microorganisms. The results demonstrated that R. rosaefolius extract at the studied concentration reduced the bacterial inocula, satisfying the criterion in all formulations, even though
it was not able to present an effective preservative behavior against fungi. Thus, the investigation of new natural substances
with preservative properties that could be applied in pharmaceutical and cosmetic products is relevant due to the possibility
of substituting or decreasing the concentration of synthetic preservatives, providing a way for the development of safer formulas
for the use of consumers. 相似文献
75.
Trovatti E Silva NH Duarte IF Rosado CF Almeida IF Costa P Freire CS Silvestre AJ Neto CP 《Biomacromolecules》2011,12(11):4162-4168
Biocellulose (BC) is a highly pure form of cellulose, produced in the form of a swollen membrane, with several applications in the biomedical area. In this study, the behavior of BC membranes as systems for topical delivery of lidocaine was evaluated. The BC-lidocaine membranes were prepared and characterized in terms of structural and morphological properties. A uniform distribution of the drug inside the BC membranes was observed. In vitro diffusion studies with Franz cells were conducted using human epidermal membranes and showed that the permeation rate of the drug in BC membranes was slightly slower than that obtained with the conventional systems, which was attributed to the establishment of interactions between the lidocaine molecules and the BC membrane, as evidenced by FTIR and NMR analysis. These results indicate that this methodology can be successfully applied for the dermal administration of lidocaine regarding the release profile and ease of application. 相似文献
76.
Souza DP Andrade MO Alvarez-Martinez CE Arantes GM Farah CS Salinas RK 《PLoS pathogens》2011,7(5):e1002031
Type IV secretion systems (T4SS) are used by Gram-negative bacteria to translocate protein and DNA substrates across the cell envelope and into target cells. Translocation across the outer membrane is achieved via a ringed tetradecameric outer membrane complex made up of a small VirB7 lipoprotein (normally 30 to 45 residues in the mature form) and the C-terminal domains of the VirB9 and VirB10 subunits. Several species from the genera of Xanthomonas phytopathogens possess an uncharacterized type IV secretion system with some distinguishing features, one of which is an unusually large VirB7 subunit (118 residues in the mature form). Here, we report the NMR and 1.0 Å X-ray structures of the VirB7 subunit from Xanthomonas citri subsp. citri (VirB7XAC2622) and its interaction with VirB9. NMR solution studies show that residues 27–41 of the disordered flexible N-terminal region of VirB7XAC2622 interact specifically with the VirB9 C-terminal domain, resulting in a significant reduction in the conformational freedom of both regions. VirB7XAC2622 has a unique C-terminal domain whose topology is strikingly similar to that of N0 domains found in proteins from different systems involved in transport across the bacterial outer membrane. We show that VirB7XAC2622 oligomerizes through interactions involving conserved residues in the N0 domain and residues 42–49 within the flexible N-terminal region and that these homotropic interactions can persist in the presence of heterotropic interactions with VirB9. Finally, we propose that VirB7XAC2622 oligomerization is compatible with the core complex structure in a manner such that the N0 domains form an extra layer on the perimeter of the tetradecameric ring. 相似文献
77.
Valdeir Arantes Adriane M. F. Milagres Timothy R. Filley Barry Goodell 《Journal of industrial microbiology & biotechnology》2011,38(4):541-555
The brown rot fungus Wolfiporia cocos and the selective white rot fungus Perenniporia medulla-panis produce peptides and phenolate-derivative compounds as low molecular weight Fe3+-reductants. Phenolates were the major compounds with Fe3+-reducing activity in both fungi and displayed Fe3+-reducing activity at pH 2.0 and 4.5 in the absence and presence of oxalic acid. The chemical structures of these compounds
were identified. Together with Fe3+ and H2O2 (mediated Fenton reaction) they produced oxygen radicals that oxidized lignocellulosic polysaccharides and lignin extensively
in vitro under conditions similar to those found in vivo. These results indicate that, in addition to the extensively studied
Gloeophyllum trabeum—a model brown rot fungus—other brown rot fungi as well as selective white rot fungi, possess the means to promote Fenton
chemistry to degrade cellulose and hemicellulose, and to modify lignin. Moreover, new information is provided, particularly
regarding how lignin is attacked, and either repolymerized or solubilized depending on the type of fungal attack, and suggests
a new pathway for selective white rot degradation of wood. The importance of Fenton reactions mediated by phenolates operating
separately or synergistically with carbohydrate-degrading enzymes in brown rot fungi, and lignin-modifying enzymes in white
rot fungi is discussed. This research improves our understanding of natural processes in carbon cycling in the environment,
which may enable the exploration of novel methods for bioconversion of lignocellulose in the production of biofuels or polymers,
in addition to the development of new and better ways to protect wood from degradation by microorganisms. 相似文献
78.
Marcela C. Pagano Miriam K. Utida Eliane A. Gomes Ivanildo E. Marriel Marta N. Cabello Maria Rita Scotti 《Ecological Indicators》2011,11(2):643-650
A large remaining of dry deciduous forest (woody Caatinga) in semi-arid Brazil has been reached by successive fires and exploratory actions what leads to the invasion of low load trees and shrub mesh, called “Carrasco vegetation”. As it restrains the sprouting of woody species, land recuperation was performed using a mixed plantation of native and Eucalyptus species to both preservation and to supply the demand for wood. In order to evaluate the recuperation, a study of microbial communities was proposed. In addition to the highest soil phosphorus content found in the Carrasco area, the greatest spore density of arbuscular mycorrhizal fungi (AMF) communities occurred in the rhizosphere of the both pioneer species: Carrasco and Eucalyptus. In contrast to the DGGE bacteria profile, it was possible to group AMF species of the preserved and experimental sites which were not clustered with Carrasco species through the DGGE of Glomales DNA and also by the principal component analysis (PCA) based on diversity index. Glomus and Acaulospora were the dominant genera at both the preserved site and Carrasco. Nevertheless, Gigaspora species were preferentially found in Dry Forest, while Scutellospora were absent. In contrast, Carrasco favoured the genus Scutellospora and the species Acaulospora scrobiculata. Our results allow one to conclude that vegetation type modifies the AMF communities, which may be used as good indicator of soil quality. Based on AMF communities as soil quality indicator, the mixed forest plantation appears to be underway towards the preserved site two years after transplantation. 相似文献
79.
80.
Mendonça-Franqueiro Ede P Alves-Paiva Rde M Sartim MA Callejon DR Paiva HH Antonucci GA Rosa JC Cintra AC Franco JJ Arantes EC Dias-Baruffi M Sampaio SV 《Acta biochimica et biophysica Sinica》2011,43(3):181-192
Snake venom lectins have been studied in regard to their chemical structure and biological functions. However, little is known about lectins isolated from Bothrops atrox snake venom. We report here the isolation and partial functional and biochemical characterization of an acidic glycan-binding protein called galatrox from this venom. This lectin was purified by affinity chromatography using a lactosyl-sepharose column, and its homogeneity and molecular mass were evaluated by high-performance liquid chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The purified galatrox was homogeneous and characterized as an acidic protein (pI 5.2) with a monomeric and dimeric molecular mass of 16.2 and 32.5 kDa, respectively. Alignment of N-terminal and internal amino acid sequences of galatrox indicated that this protein exhibits high homology to other C-type snake venom lectins. Galatrox showed optimal hemagglutinating activity at a concentration of 100 μg/ml and this effect was drastically inhibited by lactose, ethylenediaminetetraacetic acid, and heating, which confirmed galatrox's lectin activity. While galatrox failed to induce the same level of paw edema or mast cell degranulation as B. atrox crude venom, galatrox did alter cellular viability, which suggested that galatrox might contribute to venom toxicity by directly inducing cell death. 相似文献