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91.
Vanessa Carregaro José M. Ribeiro Jesus G. Valenzuela Djalma L. Souza-Júnior Diego L. Costa Carlo J. F. Oliveira Laís A. Sacramento Manuela S. L. Nascimento Cristiane M. Milanezi Fernando Q. Cunha Jo?o S. Silva 《PLoS neglected tropical diseases》2015,9(4)
Background
Sand fly saliva plays a crucial role in establishing Leishmania infection. We identified adenosine (ADO) and adenosine monophosphate (AMP) as active pharmacologic compounds present in Phlebotomus papatasi saliva that inhibit dendritic cell (DC) functions through a PGE2/IL 10-dependent mechanism.Methodology/Principal Findings
Herein, we prepared a mixture of ADO and AMP in equimolar amounts similar to those present in the salivary-gland extract (SGE) form one pair of salivary glands of P. papatasi and co-injected it with Leishmania amazonensis or L. major into mouse ears. ADO+AMP mimicked exacerbative effects of P. papatasi saliva in leishmaniasis, increasing parasite burden and cutaneous lesions. Enzymatic catabolism of salivary nucleosides reversed the SGE-induced immunosuppressive effect associated with IL-10 enhancement. Immunosuppressive factors COX2 and IL-10 were upregulated and failed to enhance ear lesion and parasite burden in IL 10-/- infected mice. Furthermore, nucleosides increased regulatory T cell (Treg) marker expression on CD4+CD25- cells, suggesting induction of Tregs on effector T cells (T eff). Treg induction (iTreg) was associated with nucleoside-induced tolerogenic dendritic cells (tDCs) expressing higher levels of COX2 and IL-10. In vitro generation of Tregs was more efficient in DCs treated with nucleosides. Suppressive effects of nucleosides during cutaneous leishmaniasis were mediated through an A2AR-dependent mechanism. Using BALB/c mice deficient in A2A ADO receptor (A2AR–/–), we showed that co-inoculated mice controlled infection, displaying lower parasite numbers at infection sites and reduced iTreg generation.Conclusion/Significance
We have demonstrated that ADO and AMP in P. papatasi saliva mediate exacerbative effects of Leishmania infection by acting preferentially on DCs promoting a tolerogenic profile in DCs and by generating iTregs in inflammatory foci through an A2AR mechanism. 相似文献92.
93.
94.
Silva Ide G Moura Ado N Dantas EW Bittencourt-Oliveira Mdo C 《Revista de biología tropical》2010,58(4):1421-1436
Natural lake systems represent important reservoirs for residential water supply, fish production, recreational activities and enjoyment of their natural beauty. Nevertheless, human impacts may affect their health status resulting in degradation and loss of biodiversity. The aim of the present study was to obtain data on the health status of a natural lake located in an indigenous reservation in the Brazilian Amazon, using the phytoplankton community changes along the rainy (June) and dry (November) seasons of 2006. We collected water (temperature, pH, Secchi depth and conductivity) and phytoplankton samples from the subsurface, middle of the water column, and approximately 30 cm above the bottom, over 24-hour sampling periods, from a central station in the lake. Samples taken from biotic and abiotic variables were correlated using canonical correspondence analysis (CCA). Results showed that the lake exhibited high temperatures in both seasons, and showed thermal stratification only during the rainy season. Dissolved oxygen exhibited a clinograde pattern in the rainy season and high oxygen in the hypolimnion in the dry season. In the rainy season, the water near the bottom was acidic, turbid and had a greater concentration of phosphorus. Dissolved oxygen, conductivity, pH, nitrite, total phosphorus and total dissolved phosphorus exhibited diel variations in the rainy season, whereas water temperature, dissolved oxygen, total nitrogen and total dissolved phosphorus exhibited significant differences between hours of the day in the dry season. The phytoplankton was represented by 39 taxa, and Chlorophyta showed the greatest species richness, totaling 25 taxa. Among Chlorophyta, desmids were the most diverse, accounting 52%. Bacillariophyta (nine species) was the second most diverse group. Cyanophyta was represented by three species, including Merismopedia tenuissima, the most abundant taxon. Despite the occurrence of taxa that indicate organic pollution, their biomass and frequency indicate that the system is not currently threatened. Lake Caracaran? is an oligotrophic system, with low algal density and isolated blooming episodes due to its shallow depth. 相似文献
95.
Edleide L. da Silva Cenira M. de Carvalho Ruth R. do Nascimento Adriana L. Mendonça Carlos E. da Silva Gláucia B. Gonçalves Maria do Rosário T. de Freitas & Antônio E. G. Sant'Ana 《Ethology : formerly Zeitschrift fur Tierpsychologie》2006,112(10):971-976
The Annona fruit borer, Cerconota anonella, causes significant damage to the fruits of Annona squamosa (custard apple) and A. muricata (soursop). The methods currently available for the control of this pest are costly and new techniques, possibly involving the use of pheromones for trapping or disrupting the mating cycle of the insect are required. In order to provide the basic information required for the development of new control systems, the reproductive behaviour of the moth was observed under laboratory conditions. The calling and courtship behaviours exhibited by virgin females and males of C. anonella commenced at the eighth hour of the scotophase and continued for a 3.5‐h period. Males were attracted by conspecific females as young as 1 d old, and showed a courtship behaviour composed of three steps: antennation, wing fanning and short flights. Mating mainly occurred when both males and females were between 2 and 5 d old, but maximum activity was observed on the third day after emergence. Receptive females elevated their wings, showing their abdomens where the abdominal hairpencils were already exposed. As part of the courtship repertoire and immediately prior to copula, males performed pronounced sideways movements of their abdomens, a behaviour that appears to be exclusive to C. anonella. 相似文献
96.
Marreiro DN do Perpetuo Socorro C Martins M de Sousa SS Ibiapina V Torres S Pires LV do Nascimento Nogueira N Lima JM do Monte SJ 《Biological trace element research》2007,120(1-3):42-50
The objective of this study was to assess urinary excretion of zinc and evaluation parameters of metabolic control in type
2 diabetic patients. Thirty-one type 2 diabetic patients, of both genders, with 5.8 ± 5.6 years average time of the disease,
age range 20–60 years, were selected. Evaluation of the nutritional status was performed using anthropometric measurements.
To evaluate food consumption, the 3-day alimentary log method was used, and its analysis was performed using a software. Determination
of urinary zinc was by atomic absorption spectrophotometry. From the obtained results, it was concluded that 51.6% of the
patients were overweight. The mean of found waist circumference was 100.4 and 92.2 cm for men and women, respectively. Blood
glucose and glycated hemoglobin values were higher than reference values, and plasma albumin concentration was adequate. The
median of found urinary zinc excretion was 474.9 μg/24 h, within normal standards (300–600 μg/day). Regarding diet composition,
calorie and protein concentration were above recommendation, while mean zinc concentration was adequate. This data allow the
conclusion that the evaluated patients presented adequate urinary zinc excretion in comparison with reference values. 相似文献
97.
Lopes AC Rodrigues JF Clementino MB Miranda CA Nascimento AP de Morais Júnior MA 《Memórias do Instituto Oswaldo Cruz》2007,102(7):827-832
PCR analysis of 16S-23S internal transcribed spacer (PCR ribotyping) and tRNA intergenic spacer (tDNA-PCR) were evaluated for their effectiveness in identification of clinical strains of Klebsiella pneumoniae and differentiation with related species. For this purpose both methods were applied to forty-three clinical isolates biochemically identified as K. pneumoniae subsp. pneumoniae isolated from patients clinical specimens attended at five hospitals in three Brazilian cities. References strains of K. pneumoniae subsp. pneumoniae, K. pneumoniae subsp. ozaenae, K. oxytoca, K. planticola and Enterobacter aerogenes were also analyzed. Both PCR methods showed specific patterns for each species. A conserved PCR ribotype pattern was observed for all clinical K. pneumoniae isolates, while differing from other related analyzed species. tDNA-PCR revealed five distinct patterns among the K. pneumoniae clinical isolates studied, demonstrating a predominant group with 90.6% of isolates presenting the same pattern of K. pneumoniae type strain. Both PCR-based methods were not able to differentiate K. pneumoniae subspecies. On the basis of the results obtained, both methods were efficient to differentiate the Klebsiella species analyzed, as well as E. aerogenes. Meanwhile tDNA-PCR revealed different tRNA arrangements in K. pneumoniae, suggesting intra-species heterogeneity of their genome organization, the polymorphism of the intergenic spacers between 16S and 23S rRNA genes appears to be highly conserved whithin K. pneumoniae clinical isolates, showing that PCR ribotyping can be an useful tool for identification of K. pneumoniae isolates. 相似文献
98.
There is evidence that 'health life expectancy' (expected number of years to be lived in health) differs by socioeconomic status. Time spent in health or disability plays a critical role in the use of health care services. The objective of this study was to estimate 'disability life expectancy' by age, gender and education attainment for the elderly of the city of S?o Paulo, Brazil, in the year 2000. Data came from the SABE database, population censuses and mortality statistics (SEADE Foundation). Life expectancy with disability was calculated using Sullivan's method on the basis of the current probability of death and prevalence of disability by educational level. The prevalence of disability increased with age, for both sexes and both levels of educational attainment studied. Men showed a lower prevalence of disability, in general, and persons with lower educational attainment showed a higher prevalence of disability. Regarding life expectancy, women could expect to live longer than men, with and without disability. For both sexes, the percentage of life expectancy lived with disability decreased with increasing educational attainment. With increasing educational attainment, the sex differences in the percentage of remaining years to be lived with disability increased for most ages. Finally, the percentage of remaining years to be lived with disability increased with age for males and females, except for males with high educational attainment between the ages 70-75 and 75-80. The results may serve as a guide for public policies in the country, since health problems faced by older persons, such as disability, are the result of a number of past experiences during their life-times, such as health care, housing conditions, hygiene practices and education. Education influences health behaviours and is related, to some extent, to all these factors. Therefore, improvements in education for the disadvantaged may improve health. 相似文献
99.
Passos XS Costa CR Araújo CR Nascimento ES e Souza LK Fernandes Ode F Sales WS Silva Mdo R 《Mycopathologia》2007,163(3):145-151
In this work, we collect data from surveys of bloodstream Candida isolates performed in Brazil from 1996 to 2004. Besides, we analyzed the species distribution of bloodstream Candida isolates together with potential risk factors for candidemia and the susceptibility profile of these isolates in patients
from Hospital das Clínicas in Goiania city, Brazil. Blood samples were collected in the admission day and on every 7 days,
in the intensive care unit (ICU) of a tertiary hospital. Candida isolates were identified by standard protocols that included germ tube formation, chlamydoconidia production on cornmeal
agar and sugar fermentation and assimilation tests. Data of patients were recorded and analyzed according to age at the time
of diagnosis, gender and presence of potential risk factors. Statistical analysis was used to determine if the time of hospital
permanence increased Candida colonization in ICU patients’ blood. The antifungal susceptibility testing was performed by broth microdilution method according
to document NCCLS/CLSI M27–A2. Among the 345 blood samples cultured, candidemia was recovered in 33 patients, which were isolated
51.5% of Candida non-albicans. Fungemia was associated with long-term hospitalization. Fluconazole, itraconzole, voriconazole and amphotericin B exhibited
a potent activity against all isolates of Candida. Voriconazole MICs were much low for all isolates tested. This work confirms data of increase of Candida non-albicans species in bloodstream in ICU and shows that voriconazole in vitro activity was higher than those of itraconazole, fluconazole and amphotericin B. 相似文献
100.
The acid base behavior of phytate has been studied (at t=25 degrees C by potentiometry, ISE-H+ glass electrode) in NaNO3aq at different ionic strengths (0.1 < or = I/mol L(-1) < or = 1.0). The interactions with copper(II) were investigated in the same experimental conditions in different metal to ligand (Phy) ratios (1:1 < or = Cu2+ :Phy < or = 4:1), by using both ISE-H+ and ISE-Cu2+ electrodes. Phytate acid base behavior in sodium nitrate is very similar to that in sodium chloride, previously investigated. In the experimental conditions adopted, the formation of three CuiHjPhy(12-2i-j)- species is observed: the mononuclear CuH4Phy6- and CuH5Phy5-, and the dinuclear Cu2H5Phy3-. Analysis of complex formation constants at different ionic strengths reveals that both ISE-H+ and ISE-Cu2+ electrodes gave, within the experimental error, analogous values. Dependence of complex formation constants on ionic strength was modeled by EDH (Extended Debye-Hückel) and SIT (Specific ion Interaction Theory) equations. The sequestering ability of phytate toward copper(II) has been evaluated by the calculation of pL50 (the total ligand concentration, as -log CL, able to bind 50% of metal cation), an empirical parameter already proposed for an objective "quantification" of this ability. A thorough analysis of literature data on phytate-copper(II) complexes has been performed. 相似文献