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101.
Summary. Glutamine is the most abundant amino acid in the body. It is an important fuel for some key cells of the immune system. Both
the plasma concentration of glutamine and the functional ability of immune cells in the blood are decreased after prolonged,
exhaustive exercise. Glutamine feeding has had beneficial effects in clinical situations, and the provision of glutamine after
intensive exercise has decreased the incidence of infections, particularly of upper respiratory tract infections. However,
the precise effect of glutamine on immunodepression in this situation is not yet established.
Received January 2, 2000 / Accepted February 1, 2000 相似文献
102.
Jose M. Castillejo Ricardo Castelló Ana G. San Cristobal Sara Abad 《Plant Ecology》2011,212(8):1287-1297
Gypsum outcrops of southeastern Spain (Almeria) have been highlighted as the most outstanding for the conservation of Iberian
gypsum flora by flora rarity and richness, as vascular as cryptogamic plants. However, plant community distribution patterns
according to soil chemical properties have been little studied in these gypsum areas. Spatial distribution pattern of plant
communities in gypsum hills and its relation to soil chemical properties was surveyed in this study. Twenty-one plots (5 × 5 m)
were settled along a semiarid gypsum gradient in Rio de Aguas Basin. Soil samples were taken from each plot’s superficial
layer for chemical analysis. Plant canopy cover was sampled at species level. Three plant community bands are identified (from
bottom to top) as level I (Flat Piedmont Zone), level II (Hill Slope Zone), and level III (Hill Top Zone). Gypsophyte species
(mainly found in level II) appear to be specifically adapted to nutrient-stressed environments (high sulfate content and deficiency
in some soil nutrients). Nutrients play an essential ecological role in determining species distribution and community composition.
Since this area is a very important site for extracting very high quality gypsum, the pattern described here can be used as
a useful tool for ecological restoration of gypsum quarries. Considering environmental heterogeneity of gypsum areas (as an
“ecosystem of reference”) is crucial for a successful ecological restoration. 相似文献
103.
José Mauro Granjeiro Carmen Verissima Ferreira Paulo Afonso Granjeiro Cinthia Celestino Da Silva Eulázio Mikio Taga Pedro Luiz Onofre Volpe 《Journal of enzyme inhibition and medicinal chemistry》2013,28(5):345-350
Uric acid inhibited 50% of the activity of bovine kidney low molecular mass phosphotyrosine protein phosphatase at concentrations of 1.0, 0.4, 1.3, and 0.2 mM, respectively for p -nitrophenyl phosphate (p -NPP), flavine mononucleotide, β -naphthyl phosphate and tyrosine phosphate (Tyr-P) as substrates. The mixed type inhibition of p -NPP hydrolysis was fully reversible, with K ic and K iu values of 0.4 and 1.1 mM, respectively; the inhibition by uric acid shifted the pH optimum from 5.0 to 6.5. When Tyr-P was the substrate, competitive inhibition was observed with a K i value of 0.05 mM. Inhibition studies by uric acid in the presence of thiol compounds, and preincubation studies in the presence of inorganic phosphate suggest that the interaction of uric acid with the enzyme occurred at the active site, but did not involve SH residues, and that the mechanism of inhibition depended on the structure of the substrates. 相似文献
104.
Carlos Fernández-Viadero Eloy Rodríguez Rodríguez Onofre Combarros Pascual Dámaso Crespo Santiago 《Revista espa?ola de geriatría y gerontología》2013
The high prevalence of Alzheimer's disease, along with the possibility of new approaches in diagnosis through the use of biomarkers of cerebrospinal fluid is shifting the focus to the elderly with dementia or at risk. In this sense it seems important to review the genetic aspects of the elderly with familial Alzheimer's disease as well as those at risk. The wide distribution of genetic studies associated with this condition may also be helpful. To the classical findings of the genes for amyloid, the presenilins and apolipoprotein E, we must add other genes recently implicated in the pathogenesis of the disease, among which are found the clusterin gene, encoding the phosphatidyl-inositol-binding clathrin assembly protein gene, and the receptor for the complement C3b protein. 相似文献
105.
Ema Carina Rosas-Burgos Mario Onofre Cortez-Rocha Maribel Plascencia-Jatomea Francisco Javier Cinco-Moroyoqui Ramón Enrique Robles-Zepeda Jaime López-Cervantes Dalia Isabel Sánchez-Machado Fernando Lares-Villa 《World journal of microbiology & biotechnology》2011,27(5):1025-1033
The aim of this study was to evaluate the effect of Baccharis glutinosa isolated extract on the growth of Aspergillus flavus and Aspergillus parasiticus, and their aflatoxin B1 production; and growth of Fusarium verticillioides, and their fumonisin B1 production. The three fungi were exposed to an antifungal fraction, designated as fraction F6-1, isolated from B. glutinosa by methanolic extraction followed by silica gel chromatography. The growth of the fungi was evaluated in kinetics of radial
extension growth, kinetics of spores germination, length and diameter of hyphae, spores diameter, as well as in aflatoxin
B1 and fumonisin B1 production. Fraction F6-1 caused radial growth inhibition of the three fungi mainly F. verticillioides. Spores germination of A. flavus and A. parasiticus was delayed in the early stage of the incubation time, although they completely germinated at 27 h. In contrast, spore germination
of F. verticillioides was inhibited 87.7% up to 96 h. The lengths and diameters of hyphae, and spore diameters of the three fungi, were significantly
smaller in comparison with those of the controls, and several morphological alterations were observed. Concerning aflatoxin
B1 and fumonisin B1, fraction F6-1 did not show any inhibition effect at the concentration used. Fraction F6-1 was able to significantly inhibit
the development of the three fungi, mainly F. verticillioides. The strong inhibitory effect of F6-1 on hyphae and spores suggests that it interacted with the fungi cell walls, which caused
severe deformities. Nevertheless, this fraction was unable in inhibiting mycotoxin production from the three fungi at the
concentration tested. 相似文献
106.
C. San Vicente J. Castelló J. Corbera A. Jimeno T. Munilla M. C. Sanz J. C. Sorbe A. Ramos 《Polar Biology》2007,30(4):477-486
During the austral summer 1995, suprabenthic samplings were carried out at 24 stations (depth range 45–649 m) located around
Livingston Island, within the caldera of Deception Island and in the Bransfield Strait. At each station, the near-bottom motile
fauna was simultaneously collected with a multinet Macer-GIROQ sled in three water layers above the bottom. This study presents
original data on the occurrence, diversity, vertical distribution and abundance of suprabenthic taxa in this near-bottom environment.
The most speciose taxa were amphipods (at least 140 spp.), followed by isopods (66 spp.), pycnogonids (31 spp.) and mysids
(19 spp.). Total abundances ranged between 31 ind./100 m2 (Bransfield Strait, 361 m depth) and 6817 ind./100 m2 (South Livingston Island, 163 m depth). According to stations, the groups numerically dominant and more frequent were amphipods
(17 stations) or mysids (seven stations). Four suprabenthic assemblages were discriminated in the study area, apparently more
structured by the degree of shelter-exposure and development of sessile epifauna than by water depth or sediment features. 相似文献
107.
Joo Paulo Ferreira Rodrigues Thiago Souza Onofre Bruno Couto Barbosa den Ramalho Ferreira Alexis Bonfim‐Melo Nobuko Yoshida 《Cellular microbiology》2019,21(5)
Host cell invasion by Trypanosoma cruzi metacyclic trypomastigote (MT) is mediated by MT‐specific surface molecule gp82, which binds to a still unidentified receptor, inducing lysosome spreading and exocytosis required for the parasitophorous vacuole formation. We examined the involvement of the major lysosome membrane‐associated LAMP proteins in MT invasion. First, human epithelial HeLa cells were incubated with MT in the presence of antibody to LAMP‐1 or LAMP‐2. Antibody to LAMP‐2, but not to LAMP‐1, significantly reduced MT invasion. Next, HeLa cells depleted in LAMP‐1 or LAMP‐2 were generated. Cells deficient in LAMP‐2, but not in LAMP‐1, were significantly more resistant to MT invasion than wild‐type controls. The possibility that LAMP‐2 might be the receptor for gp82 was examined by co‐immunoprecipitation assays. Protein A/G magnetic beads cross‐linked with antibody directed to LAMP‐1 or LAMP‐2 were incubated with HeLa cell and MT detergent extracts. Gp82 bound to LAMP‐2 but not to LAMP‐1. Binding of the recombinant gp82 protein to wild‐type and LAMP‐1‐deficient cells, which was dose dependent and saturable, had a similar profile and was much higher as compared with LAMP‐2‐depleted cells. These data indicate that MT invasion is accomplished through recognition of gp82 by its receptor LAMP‐2. 相似文献
108.
Cellular Senescence Induced by Prolonged Subculture Adversely Affects Glutamate Uptake in C6 Lineage
Mery Stéfani Leivas Pereira Kamila Zenki Marcela Mendonça Cavalheiro Chairini Cássia Thomé Eduardo Cremonese Filippi-Chiela Guido Lenz Diogo Onofre Gomes de Souza Diogo Losch de Oliveira 《Neurochemical research》2014,39(5):973-984
Several researchers have recently used C6 cells to evaluate functional properties of high-affinity glutamate transporters. However, it has been demonstrated that this lineage suffers several morphological and biochemical alterations according to the number of passages in culture. Currently, there are no reports showing whether functional properties of high-affinity glutamate transporters comply with these sub culturing-dependent modifications. The present study aimed to compare the functional properties of high-affinity glutamate transporters expressed in early (EPC6) and late (LPC6) passage C6 cells through a detailed pharmacological and biochemical characterization. Between 60–180 min of l-[3H]glu incubation, LPC6 presented an intracellular [3H] 55 % lower than EPC6. Both cultures showed a time-dependent increase of intracellular [3H] reaching maximal levels at 120 min. Cultures incubated with d-[3H]asp showed a time-dependent increase of [3H] until 180 min. Moreover, LPC6 have a d-[3H]asp-derived intracellular [3H] 30–45 % lower than EPC6 until 120 min. Only EAAT3 was immunodetected in cultures and its total content was equal between them. PMA-stimulated EAAT3 trafficking to membrane increased 50 % of l-[3H]glu-derived intracellular [3H] in EPC6 and had no effect in LPC6. LPC6 displayed characteristics that resemble senescence, such as high β-Gal staining, cell enlargement and increase of large and regular nuclei. Our results demonstrated that LPC6 exhibited glutamate uptake impairment, which may have occurred due to its inability to mobilize EAAT3 to cell membrane. This profile might be related to senescent process observed in this culture. Our results suggest that LPC6 cells are an inappropriate glial cellular model to investigate the functional properties of high-affinity glutamate transporters. 相似文献
109.
Leila do Nascimento Vieira Helisson Faoro Hugo Pacheco de Freitas Fraga Marcelo Rogalski Emanuel Maltempi de Souza Fábio de Oliveira Pedrosa Rubens Onofre Nodari Miguel Pedro Guerra 《PloS one》2014,9(1)
Background
Performing chloroplast DNA (cpDNA) isolation is considered a major challenge among different plant groups, especially conifers. Isolating chloroplasts in conifers by such conventional methods as sucrose gradient and high salt has not been successful. So far, plastid genome sequencing protocols for conifer species have been based mainly on long-range PCR, which is known to be time-consuming and difficult to implement.Methodology/Principal Findings
We developed a protocol for cpDNA isolation using three different conifer families: Araucaria angustifolia and Araucaria bidwilli (Araucariaceae), Podocarpus lambertii (Podocarpaceae) and Pinus patula (Pinaceae). The present protocol is based on high salt isolation buffer followed by saline Percoll gradient. Combining these two strategies allowed enhanced chloroplast isolation, along with decreased contamination caused by polysaccharides, polyphenols, proteins, and nuclear DNA in cpDNA. Microscopy images confirmed the presence of intact chloroplasts in high abundance. This method was applied to cpDNA isolation and subsequent sequencing by Illumina MiSeq (2×250 bp), using only 50 ng of cpDNA. Reference-guided chloroplast genome mapping showed that high average coverage was achieved for all evaluated species: 24.63 for A. angustifolia, 135.97 for A. bidwilli, 1196.10 for P. lambertii, and 64.68 for P. patula.Conclusion
Results show that this improved protocol is suitable for enhanced quality and yield of chloroplasts and cpDNA isolation from conifers, providing a useful tool for studies that require isolated chloroplasts and/or whole cpDNA sequences. 相似文献110.
Ludovic Lacroix Sophie F. Post Alexander Valent Antoine E. Melkane Philippe Vielh Coumaran Egile Christelle Castell Christelle Larois Sandrine Micallef Patrick Saulnier Hélène Goulaouic Anne-Marie Lefebvre Stéphane Temam 《PloS one》2014,9(1)