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81.
Potamotrygonidae is the representative family of South American freshwater elasmobranchs. It is a monophyletic group containing
20 species grouped into three genera. Three species belonging to two genera of this family were collected from the middle
Negro River, Amazonas, Brazil, and studied cytogenetically: Paratrygon aiereba, Potamotrygon motoro and Potamotrygon orbignyi. Paratrygon aiereba presented 2n = 90 chromosomes and 4M+2SM+10ST+74A. Both species of Potamotrygon presented 2n = 66 chromosomes and differed in their chromosomal formulas: P. motoro had 18M+12SM+10ST+26A and P. orbignyi had 22M+10SM+8ST+26A. No sex heteromorphism was detected. The Fundamental Number (FN) was 106 for the three species. A system
of multiple NORs was found in the three species, but with interspecific differences in terms of location and position of the
active Ag-NORs sites. Paratrygon aiereba presented only four sites on the short arms of two chromosomal pairs, both in terminal regions. Potamotrygon motoro presented seven sites, on the long and short arms, all in terminal regions of non-homologous chromosomes; P. orbignyi presented eight sites on the long arms, all in terminal regions, of non-homologous chromosomes. The constitutive heterochromatin
was in pericentromeric regions of all chromosomes, and no significant interspecific difference was found in relation to this
marker. 相似文献
82.
A comparative analysis of G-banded karyotypes was performed for seven species of Chiroptera, representing two families (Phyllostomidae
and Molossidae). Despite the differences in diploid and fundamental numbers, extensive homologies between six karyotypes were
identified: A . planirostris, P. lineatus, S. lilium, G. soricina, P. hastatus (Phyllostomidae) and M. rufus (Molossidae). Robertsonian rearrangements and pericentric inversions account for the differences between the karyotypes of
phyllostomid and molossid species. The homologies and rearrangements observed reinforce the monophiletic origin of phyllostomids
and the inclusion of species in different subfamilies. In situ hybridization with genomic DNA revealed considerable conservation of the karyotypes, including C. perspicillata, that did not show G-band homologies with the other species analyzed. For the first time, chromosomal evidence is presented
of a common origin for Phyllostomidae and Molossidae. 相似文献
83.
84.
Antimicrobial resistance of Pseudomonas aeruginosa biofilms 总被引:10,自引:0,他引:10
Drenkard E 《Microbes and infection / Institut Pasteur》2003,5(13):1213-1219
Resistance to antimicrobial agents is the most important feature of biofilm infections. As a result, infections caused by bacterial biofilms are persistent and very difficult to eradicate. Although several mechanisms have been postulated to explain reduced susceptibility to antimicrobials in bacterial biofilms, it is becoming evident that biofilm resistance is multifactorial. The contribution of each of the different mechanisms involved in biofilm resistance is now beginning to emerge. 相似文献
85.
JH Lee JM Lee EM Ramos T Gillis JS Mysore S Kishikawa T Hadzi AE Hendricks MR Hayden PJ Morrison M Nance CA Ross RL Margolis F Squitieri C Gellera E Gomez-Tortosa C Ayuso O Suchowersky RJ Trent E McCusker A Novelletto M Frontali R Jones T Ashizawa S Frank MH Saint-Hilaire SM Hersch HD Rosas D Lucente MB Harrison A Zanko RK Abramson K Marder J Sequeiros G Bernhard Landwehrmeyer;On behalf of the Registry Study of the European Huntington’s Disease Network 《Biochemical and biophysical research communications》2012,426(3):404-408
86.
GB Menezes FA Pereira CA Duarte TM Carmo HP Silva Filho MA Zarife MA Krieger EA Reis MG Reis 《Memórias do Instituto Oswaldo Cruz》2012,107(5):680-683
The hepatitis C virus (HCV) can be detected in blood and other bodily fluids, such as saliva, semen and gastric juices. The aim of this study was to compare the HCV viral loads in the serum and saliva of infected patients. Twenty-nine patients with detectable HCV RNA in their serum and saliva were included in this study. The HCV viral loads were determined through quantitative real-time polymerase chain reactions. The median viral RNA levels were 5.78 log10 copies in the serum and 3.32 log10 copies in the saliva. We observed that the salivary HCV viral load was significantly lower than the viral load in the serum. Further studies are required to understand the role of saliva in the diagnosis, management and potential transmission of HCV. 相似文献
87.
DF Henriques JA Quaresma HT Fuzii MR Nunes EV Silva VL Carvalho LC Martins SM Casseb JO Chiang PF Vasconcelos 《Memórias do Instituto Oswaldo Cruz》2012,107(5):630-636
Rocio virus (ROCV) is an encephalitic flavivirus endemic to Brazil. Experimental flavivirus infections have previously demonstrated a persistent infection and, in this study, we investigated the persistence of ROCV infection in golden hamsters (Mesocricetus auratus). The hamsters were infected intraperitoneally with 9.8 LD50/0.02 mL of ROCV and later anaesthetised and sacrificed at various time points over a 120-day period to collect of blood, urine and organ samples. The viral titres were quantified by real-time-polymerase chain reaction (qRT-PCR). The specimens were used to infect Vero cells and ROCV antigens in the cells were detected by immunefluorescence assay. The levels of antibodies were determined by the haemagglutination inhibition technique. A histopathological examination was performed on the tissues by staining with haematoxylin-eosin and detecting viral antigens by immunohistochemistry (IHC). ROCV induced a strong immune response and was pathogenic in hamsters through neuroinvasion. ROCV was recovered from Vero cells exposed to samples from the viscera, brain, blood, serum and urine and was detected by qRT-PCR in the brain, liver and blood for three months after infection. ROCV induced histopathological changes and the expression of viral antigens, which were detected by IHC in the liver, kidney, lung and brain up to four months after infection. These findings show that ROCV is pathogenic to golden hamsters and has the capacity to cause persistent infection in animals after intraperitoneal infection. 相似文献
88.
de Lima-Netto S Pinheiro A Nakano E Zucatelli Mendonça RM Barros-Battesti DM Mendonça RZ 《Cytotechnology》2012,64(5):601-606
The control of viral infections, especially those caused by influenza viruses, is of great interest in Public Health. Bio prospection has shown the presence of active principles in the hemolymph of arthropods, and in the salivary gland of ticks, and some of these are of interest for the development of new pharmacological drugs. Ticks lay their eggs in the environment, and to protect them from desiccation and microbial attack they involve the eggs in a waxy layer produced by an organ known as Gené’s Organ. In this study, the eggs wax from tick Amblyomma cajennense (Fabricius) was extracted using ice cold phosphate buffer. The antiviral activity was evaluated with picornavirus and influenza virus. In both cases egg wax was able to inhibit virus replication. For influenza virus, an amount as small as 12 μg/mL of crude egg wax suspension neutralized 128 UHA (hemaglutinant unit) of H1N1 influenza virus. With picornavirus, egg wax led to a 256-fold reduction in virus production by L929 cells. Egg wax was not cytotoxic to VERO, MDCK and L929 cell, being observed that the cell morphology was preserved with concentration as high as 2 mg/mL. In addition no genotoxic effect was observed for Vero cells, suggesting a very interesting potential antiviral activity. 相似文献
89.
90.