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71.
Hélio V. Nobre-Júnior Ricardo A. Oliveira Flavio D. Maia Marcelle A. S. Nogueira Manoel Odorico de Moraes Mary Anne M. Bandeira Geanne M. Andrade Glauce S. B. Viana 《Neurochemical research》2009,34(6):1066-1075
In the present work, we showed that a chalcone-enriched fraction (CEF) isolated from the stem bark of a Brazilian medicinal
plant, Myracrodruon
urundeuva, presents neuroprotective actions on 6-hydroxydopamine (6-OHDA)-induced neuronal cell death, in rat mesencephalic cells.
In the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium] assay, which is an index of cell viability, CEF (1–100 μg/ml)
reversed in a concentration-dependent manner the 6-OHDA-induced cell death. While cells exposed to 6-OHDA (40 μM) showed an
increased concentration of thiobarbituric acid reactive substances (TBARS), the pretreatment with CEF (10–100 μg/ml) significantly
decreased the 6-OHDA-induced TBARS formation, indicative of a neuroprotection against lipoperoxidation. Furthermore, the drastic
increase of nitrite levels induced by 6-OHDA, indicative of nitric oxide formation and free radicals production, was prevented
by CEF. Double staining with acridine orange/ethidium bromide showed that cultures exposed to 6-OHDA (40 and 200 μM) presented
an increase of apoptotic and necrotic cell numbers in a concentration-dependent manner. CEF (100 μg/ml) protected cells from
apoptosis and necrosis and increased number of cells presenting a normal morphology. The immunohistochemical analysis for
tyrosine hydroxylase (TH) positive neurons indicated that 6-OHDA (40 and 200 μM) caused a concentration-dependent loss of
TH+ and TH− neurons. CEF protected both cells types from 6-OHDA-induced cell death. All together, our results demonstrated
neuroprotective effects of chalcones, which are able to reduce oxidative stress and apoptotic injury caused by 6-OHDA. Our
findings suggest that chalcones could provide benefits, along with other therapies, in neurodegenerative injuries, such as
Parkinson’s disease. 相似文献
72.
Erika P. J. Britto Manoel G. C. GondimJr. Jorge B. Torres Komi K. M. Fiaboe Gilberto J. Moraes Markus Knapp 《BioControl》2009,54(3):363-368
Predatory behaviour and reproductive output of the ladybird beetle Stethorus tridens Gordon as function of the tomato red spider mite (TRSM), Tetranychus evansi Baker & Pritchard, densities was investigated in the laboratory. Adult female of S. tridens were isolated in cylindrical plastic arenas, containing a leaf disc of Solanum americanum Mill. with 5, 20, 40, 60, 80 or 100 T. evansi nymphs. The number of prey consumed and eggs laid were evaluated daily for ten consecutive days, starting at the oviposition.
Oviposition of S. tridens was positively correlated with prey consumption and lower threshold prey consumption for S. tridens laying eggs was 16.3 mites per day. The instantaneous rate of attack (ca. discovery area) and the handling time were 0.0062 h−1 and 0.83 h, and 0.00254 h−1 and 0.78 h, respectively, for predators at the 1st- and 10th-oviposition day. The predator exhibited a type II functional
response at 1st- and 10th-oviposition day with a maximum consumption per predator of 33 T. evansi nymphs per day at the highest prey density. The ladybird beetle S. tridens is often collected associated with red spider mite colonies on solanaceous wild plants and the results suggest the potential
of this ladybird beetle to control T. evansi in tomatoes crops.
Handling editor: Eric Lucas. 相似文献
73.
Jacqueline Araújo Fiuza Ricardo Toshio Fujiwara Juliana Assis Silva Gomes Manoel Otávio das Costa Rocha Ana Thereza Chaves Fernanda Fortes de Araújo Rafaelle Christine Gomes Fares Andrea Teixeira-Carvalho Olindo de Assis Martins-Filho Guilherme Grossi Lopes Can?ado Rodrigo Correa-Oliveira 《PLoS neglected tropical diseases》2009,3(9)
Background
Chronic Chagas disease presents several different clinical manifestations ranging from asymptomatic to severe cardiac and/or digestive clinical forms. Several studies have demonstrated that immunoregulatory mechanisms are important processes for the control of the intense immune activity observed in the chronic phase. T cells play a critical role in parasite specific and non-specific immune response elicited by the host against Trypanosoma cruzi. Specifically, memory T cells, which are basically classified as central and effector memory cells, might have a distinct migratory activity, role and function during the human Chagas disease.Methodology/Principal Findings
Based on the hypothesis that the disease severity in humans is correlated to the quality of immune responses against T. cruzi, we evaluated the memory profile of peripheral CD4+ and CD8+ T lymphocytes as well as its cytokine secretion before and after in vitro antigenic stimulation. We evaluated cellular response from non-infected individuals (NI), patients with indeterminate (IND) or cardiac (CARD) clinical forms of Chagas disease. The expression of CD45RA, CD45RO and CCR7 surface molecules was determined on CD4+ and CD8+ T lymphocytes; the pattern of intracellular cytokines (IFN-γ, IL-10) synthesized by naive and memory cells was determined by flow cytometry. Our results revealed that IND and CARD patients have relatively lower percentages of naive (CD45RAhigh) CD4+ and CD8+ T cells. However, statistical analysis of ex-vivo profiles of CD4+ T cells showed that IND have lower percentage of CD45RAhigh in relation to non-infected individuals, but not in relation to CARD. Elevated percentages of memory (CD45ROhigh) CD4+ T cells were also demonstrated in infected individuals, although statistically significant differences were only observed between IND and NI groups. Furthermore, when we analyzed the profile of secreted cytokines, we observed that CARD patients presented a significantly higher percentage of CD8+CD45RAhigh IFN-γ-producing cells in control cultures and after antigen pulsing with soluble epimastigote antigens.Conclusions
Based on a correlation between the frequency of IFN-γ producing CD8+ T cells in the T cell memory compartment and the chronic chagasic myocarditis, we propose that memory T cells can be involved in the induction of the development of the severe clinical forms of the Chagas disease by mechanisms modulated by IFN-γ. Furthermore, we showed that individuals from IND group presented more TCM CD4+ T cells, which may induce a regulatory mechanism to protect the host against the exacerbated inflammatory response elicited by the infection. 相似文献74.
Rocha DD Militão GC Veras ML Pessoa OD Silveira ER Alves AP de Moraes MO Pessoa C Costa-Lotufo LV 《Life sciences》2006,79(18):1692-1701
Withaphysalins are C(28)-steroidal lactones structurally based on the ergostane skeleton that possess antiproliferative activity against tumor cell lines. In the present study, the antileukemic actvity of withaphysalin O (1), M (2), and N (3) isolated from Acnistus arborescens, against two leukemic cell lines, HL-60 and K562, was evaluated, and the cytotoxicity compared with the effects on peripheral blood mononuclear cells (PBMC). All tested compounds reduced the number of viable cells of the tumor cell lines after 24 h of exposure, except for compound 2 against the K562 cell line. The reduction was time-and concentration-dependent, and the IC(50) values ranged from 0.7 to 3.5 microM after 72 h of incubation. In addition to the growth inhibitory properties, the drugs decreased DNA synthesis after 24 h of drug exposure evaluated by the 5-bromo-2 -deoxyuridine incorporation method. None of the tested compounds reduced the number of PBMC (IC(50)>20 microM) after 72 h of incubation, in contrast to doxorubicin that decreased viable cells and increased non-viable cells even after 24 h of incubation. Morphological analysis of treated cells using hematoxylin/eosin staining indicated the presence of necrotic cells for all tested compounds in HL-60, confirmed by the use of acridine orange/ethidium bromide staining. In addition to necrotic cells, K562 cells showed morphological alterations consistent with apoptosis. 相似文献
75.
76.
Lion MB Eizirik E Garda AA Fontoura-Rodrigues ML Rodrigues FH Marinho-Filho JS 《Genetica》2011,139(3):369-381
Maned wolves are large canids currently considered vulnerable to extinction due to habitat loss. They are still commonly found
within the urban mesh inside the Brazilian Federal District (Distrito Federal—DF), in nearby Protected Areas (PAs), and in
surrounding farms. We evaluated the genetic diversity of maned wolves in three PAs of the DF, using both invasive and noninvasive
techniques to obtain DNA that was later amplified for five microsatellite markers. We sampled 23 wolves: 10 with the noninvasive
method, three captured in traps, six road-killed, and four rescued in urban areas. In águas Emendadas Ecological Station (ESECAE)
we also used samples from six specimens captured between 1997 and 1998 for a temporal comparison. For maned wolves, non-invasive
techniques are affordable and easier to conduct in the field, while laboratory costs are much lower for invasive samples.
Hence, a sampling strategy combining both techniques may provide an interesting approach for molecular ecology studies requiring
comprehensive coverage of local individuals. On the basis of such integrated sampling scheme, our analyses indicated that
none of the investigated populations currently present deviations from Hardy–Weinberg expectations or indication of inbreeding.
Furthermore, in ESECAE there was no reduction in genetic diversity during the last 9 years. Overall, maned wolves did not
present evidence of genetic structuring among the three sampled PAs. These results thus indicate that individual exchange
among PAs is still occurring at sufficient rates to avoid differentiation, and/or that the recent fragmentation in the region
has not yet produced measurable effects in the genetic diversity of maned wolves. 相似文献
77.
Brilhante RS Paiva MA Sampaio CM Teixeira CE Castelo-Branco DS Leite JJ Moreira CA Silva LP Cordeiro RA Monteiro AJ Sidrim JJ Rocha MF 《FEMS microbiology ecology》2011,76(2):268-277
In the present study, it was sought to compare yeast microbiota of wild and captive Macrobrachium amazonicum and evaluate the antifungal susceptibility and production of virulence factors by the recovered isolates of Candida spp. Additionally, cultivation water was monitored for the presence of fungi. Overall, 26 yeast isolates belonging to three genera and seven species were obtained, out of which 24 were Candida spp., with Candida famata as the most prevalent species for both wild and captive prawns. From cultivation water, 28 isolates of filamentous fungi were obtained, with Penicillium spp., Cladosporium spp. and Aspergillus spp. as the most frequent genera. Eight out of 24 Candida spp. isolates were resistant to azole derivatives, out of which four were recovered from wild-harvested prawns. As for production of virulence factors, three (12.5%) and eight (33.3%) isolates presented phospholipase and protease activity, respectively. This is the first comparative study between wild and captive prawns and the first report on yeast microbiota of M. amazonicum. The most relevant finding was the high percentage of resistant Candida spp., including from wild individuals, which suggests the occurrence of an environmental imbalance in the area where these prawns were captured. 相似文献
78.
Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of coconut in many countries in the Americas, Africa and parts of
Asia. Neoseiulus baraki Athias-Henriot (Acari: Phytoseiidae) is one of the predatory mites most commonly found in association with A. guerreronis in parts of northeast Brazil. The objective of this work was to study the distribution of A. guerreronis and N. baraki among and within coconut bunches. The hypothesis was tested that A. guerreronis and N. baraki are homogenously distributed over the fruits in a bunch, independent of the fruits’ age and position. Five collections of
bunches, each corresponding to leaves 12–16 from apex (about 2–6 month-old), were conducted in each of three fields in northeastern
Brazil, from February to October, 2007. A total of 1,986 fruits were examined. The number of mites, the percentage of fruits
hosting them and the level of damage caused by A. guerreronis were evaluated. The highest density of A. guerreronis was observed on fruits of bunch 4 whereas the highest density of N. baraki was observed on bunch 5. Considering all fruits together, no significant differences were observed between densities of either
A. guerreronis or N. baraki among the basal, median and apical thirds of the bunches. In younger bunches, fruits of the apical region tend to have lower
densities of both mites than fruits of the basal region. This pattern, in association with a similar pattern for the percentage
of fruits hosting N. baraki, suggests that the predator initially reaches the basal bunch region, from where it moves to the apical region. The results
of the present study suggest that the pest population reduction in bunches older than bunch 4 could be due to (1) an effect
of the predator, (2) reduction of the proportion of undamaged tissues amenable to attack, and/or (3) less favorable characteristics
of the fruits to attack by A. guerreronis, as indicated by their increasing lignin content as they get older. 相似文献
79.
Andréia?S.?Galv?o Manoel?G.?C.?GondimJr.Email author Gilberto?J.?Moraes 《Experimental & applied acarology》2011,53(3):245-252
Aceria guerreronis Keifer (Acari: Eriophyidae) is a major pest of coconut fruits (Cocos nucifera L.) in many countries of the Americas, Africa, and parts of Asia. Considerable attention has been given to studies of biological
control agents of A. guerreronis. Proctolaelaps bulbosus Moraes, Reis and Gondim Jr. is a predator recently discovered in association with A. guerreronis. Nothing is known about its biology. The aim of this study was to determine suitable food sources for P. bulbosus, among items commonly found on coconut fruits, including A. guerreronis. Food sources evaluated included the mites A. guerreronis, Steneotarsonemus concavuscutum Lofego and Gondim Jr., and Tyrophagus putrescentiae (Schrank), the fungus Rhizopus aff. stolonifer (Ehrenb.) Vuill and coconut pollen; the mite Tetranychus urticae Koch was also included in the assessments, for being a commonly used prey for mass production and laboratory rearing of predatory
mites. Proctolaelaps
bulbosus was able to develop up to adulthood when fed A. guerreronis,
R. aff. stolonifer and T. putrescentiae. It had the highest population growth rates when feeding on the former (R
o = 17.5; r
m = 0.392). These results indicate that A. guerreronis is the most suitable food for P. bulbosus among the possible food sources found on coconut fruits and that P. bulbosus can survive in the absence of eriophyid using R. aff. stolonifer as a food source. 相似文献
80.
Doseth B Visnes T Wallenius A Ericsson I Sarno A Pettersen HS Flatberg A Catterall T Slupphaug G Krokan HE Kavli B 《The Journal of biological chemistry》2011,286(19):16669-16680
Genomic uracil is a DNA lesion but also an essential key intermediate in adaptive immunity. In B cells, activation-induced cytidine deaminase deaminates cytosine to uracil (U:G mispairs) in Ig genes to initiate antibody maturation. Uracil-DNA glycosylases (UDGs) such as uracil N-glycosylase (UNG), single strand-selective monofunctional uracil-DNA glycosylase 1 (SMUG1), and thymine-DNA glycosylase remove uracil from DNA. Gene-targeted mouse models are extensively used to investigate the role of these enzymes in DNA repair and Ig diversification. However, possible species differences in uracil processing in humans and mice are yet not established. To address this, we analyzed UDG activities and quantities in human and mouse cell lines and in splenic B cells from Ung(+/+) and Ung(-/-) backcrossed mice. Interestingly, human cells displayed ~15-fold higher total uracil excision capacity due to higher levels of UNG. In contrast, SMUG1 activity was ~8-fold higher in mouse cells, constituting ~50% of the total U:G excision activity compared with less than 1% in human cells. In activated B cells, both UNG and SMUG1 activities were at levels comparable with those measured for mouse cell lines. Moreover, SMUG1 activity per cell was not down-regulated after activation. We therefore suggest that SMUG1 may work as a weak backup activity for UNG2 during class switch recombination in Ung(-/-) mice. Our results reveal significant species differences in genomic uracil processing. These findings should be taken into account when mouse models are used in studies of uracil DNA repair and adaptive immunity. 相似文献