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81.
Oocytes were recovered by ovum pick up (OPU) from nine pairs of monozygotic twin German Simmental cows. The hypothesis was that there is less variability between identical twins versus among non-related individuals in the variation in the recovery of oocytes by OPU and in the efficiency of in vitro embryo production. Estrous cycles were synchronized with two doses of cloprostenol, 11 days apart. Beginning 3-4 days after synchronized estrus, OPU was done twice weekly (every 3 or 4 days; total of 11 sessions). The influence of repeated OPU on estrous cyclicity was established by estrus detection, plasma progesterone concentrations, and ovarian ultrasonography. There were no differences among days of collection for the number and quality of cumulus oocyte-complexes (COCs), and rates of cleavage and blastocyst formation. A total of 1,661 COCs, including 657 (39.6%) good-quality COCs, were recovered. From 1,457 (87.7%) cultured COCs, 827 zygotes cleaved and 314 blastocysts were produced on Day 7. The total number of COCs and the blastocyst rates varied among pairs of monozygotic twins; within pairs, only slight differences were observed. In conclusion, recovery of COCs and production of embryos had substantially less variation within pairs of monozygotic twins than among non-related cattle. 相似文献
82.
Reena Ghildyal Adeline Ho Manisha Dias Lydia Soegiyono Phillip G. Bardin Kim C. Tran Michael N. Teng David A. Jans 《Journal of virology》2009,83(11):5353-5362
The respiratory syncytial virus (RSV) matrix (M) protein is localized in the nucleus of infected cells early in infection but is mostly cytoplasmic late in infection. We have previously shown that M localizes in the nucleus through the action of the importin β1 nuclear import receptor. Here, we establish for the first time that M''s ability to shuttle to the cytoplasm is due to the action of the nuclear export receptor Crm1, as shown in infected cells, and in cells transfected to express green fluorescent protein (GFP)-M fusion proteins. Specific inhibition of Crm1-mediated nuclear export by leptomycin B increased M nuclear accumulation. Analysis of truncated and point-mutated M derivatives indicated that Crm1-dependent nuclear export of M is attributable to a nuclear export signal (NES) within residues 194 to 206. Importantly, inhibition of M nuclear export resulted in reduced virus production, and a recombinant RSV carrying a mutated NES could not be rescued by reverse genetics. That this is likely to be due to the inability of a nuclear export deficient M to localize to regions of virus assembly is indicated by the fact that a nuclear-export-deficient GFP-M fails to localize to regions of virus assembly when expressed in cells infected with wild-type RSV. Together, our data suggest that Crm1-dependent nuclear export of M is central to RSV infection, representing the first report of such a mechanism for a paramyxovirus M protein and with important implications for related paramyxoviruses.The Pneumovirus respiratory syncytial virus (RSV) within the Paramyxoviridae family is the most common cause of lower-respiratory-tract disease in infants (7). The negative-sense single-strand RNA genome of RSV encodes two nonstructural and nine structural proteins, comprising the envelope glycoproteins (F, G, and SH), the nucleocapsid proteins (N, P, and L), the nucleocapsid-associated proteins (M2-1 and M2-2), and the matrix (M) protein (1, 7, 11). Previously, we have shown that M protein localizes in the nucleus at early stages of infection, but later in infection it is localized mainly in the cytoplasm, in association with nucleocapsid-containing cytoplasmic inclusions (13, 16). The M proteins of other negative-strand viruses, such as Sendai virus, Newcastle disease virus, and vesicular stomatitis virus (VSV), have also been observed in the nucleus at early stages of infection (32, 40, 48). Interestingly, the M proteins of all of these viruses, including RSV, play major roles in virus assembly, which take place in the cytoplasm and at the cell membrane (11, 12, 24, 34, 36, 39), but the mechanisms by which trafficking between the nucleus and cytoplasm occurs are unknown.The importin β family member Crm1 (exportin 1) is known to mediate nuclear export of proteins bearing leucine-rich nuclear export signals (NES) (8, 9, 18, 19, 37, 42, 43), such as the human immunodeficiency virus type 1 Rev protein (4). In the case of the influenza virus matrix (M1) protein, binding to the influenza virus nuclear export protein, which possesses a Crm1-recognized NES, appears to be responsible for its export from the nucleus, bound to the influenza virus RNA (3).We have recently shown that RSV M localizes in the nucleus through a conventional nuclear import pathway dependent on the nuclear import receptor importin β1 (IMPβ1) and the guanine nucleotide-binding protein Ran (14). In the present study, we show for the first time that RSV M possesses a Crm1-dependent nuclear export pathway, based on experiments using the specific inhibitor leptomycin B (LMB) (25), both in RSV-infected cells and in green fluorescent protein (GFP)-M fusion protein-expressing transfected cells. We use truncated and point-mutated M derivatives to map the Crm1-recognized NES within the M sequence and show that Crm1-dependent nuclear export is critical to the RSV infectious cycle, since LMB treatment early in infection, inhibiting M export from the nucleus, reduces RSV virion production and a recombinant RSV carrying a NES mutation in M was unable to replicate, probably because M deficient in nuclear export could not localize to areas of virus assembly, as shown in RSV-infected cells transfected to express GFP-M. This is the first report of a Crm1-mediated nuclear export pathway for a paramyxovirus M protein, with implications for the trafficking and function of other paramyxovirus M proteins. 相似文献
83.
Israel de Souza Pinto Bruna Dias das Chagas Andressa Alencastre Fuzari Rodrigues Adelson Luiz Ferreira Helder Ricas Rezende Rafaela Vieira Bruno Aloisio Falqueto José Dilermando Andrade-Filho Eunice Aparecida Bianchi Galati Paloma Helena Fernandes Shimabukuro Reginaldo Pe?anha Brazil Alexandre Afranio Peixoto 《PloS one》2015,10(10)
DNA barcoding has been an effective tool for species identification in several animal groups. Here, we used DNA barcoding to discriminate between 47 morphologically distinct species of Brazilian sand flies. DNA barcodes correctly identified approximately 90% of the sampled taxa (42 morphologically distinct species) using clustering based on neighbor-joining distance, of which four species showed comparatively higher maximum values of divergence (range 4.23–19.04%), indicating cryptic diversity. The DNA barcodes also corroborated the resurrection of two species within the shannoni complex and provided an efficient tool to differentiate between morphologically indistinguishable females of closely related species. Taken together, our results validate the effectiveness of DNA barcoding for species identification and the discovery of cryptic diversity in sand flies from Brazil. 相似文献
84.
Carlos Albuquerque Francisco Morinha João Requicha Isabel Dias Henrique Guedes-Pinto Carlos Viegas Estela Bastos 《Gene》2014
Periodontal disease (PD) refers to a group of inflammatory diseases that affect the periodontium, the organ which surrounds and supports the teeth. PD is a highly prevalent disease with a multifactorial etiology and, in humans the individual susceptibility is known to be strongly determined by genetic factors. Several candidate genes have been studied, namely genes related with molecules involved in the inflammatory response. Interleukin-10 (IL-10) is a cytokine with important anti-inflammatory and immunomodulatory roles, and several studies indicate an association between IL10 polymorphisms and PD. In dogs, an important animal model in periodontology, PD is also a highly prevalent naturally occurring disease, and only now are emerging the first studies evaluating the genetic predisposition. In this case–control study, a population of 90 dogs (40 dogs with PD and 50 healthy dogs) was used to study the IL10 gene, and seven new genetic variations in this gene were identified. No statistically significant differences were detected in genotype and allele frequencies of these variations between the PD cases and control groups. Nevertheless, one of the variations (IL10/2_g.285G > A) leads to an amino acid change (glycine to arginine) in the putative signal peptide, being predicted a potential influence on IL-10 protein functionality. Further investigations are important to clarify the biological importance of these new findings. The knowledge of these genetic determinants can help to understand properly the complex causal pathways of PD, with important clinical implications. 相似文献
85.
Michel D. Gianeti Francisco M. Santana Leandro Yokota Jonas E. Vasconcelos June F. Dias Rosangela P. Lessa 《Journal of fish biology》2019,94(3):481-488
We collected 729 Hypanus guttatus from the northern coast of the state of Rio Grande do Norte (RN), of which 196 were used to estimate age and growth. Ninety-five were male (12.7 to 57.0 cm disc width; WD) and 101 were female (13.0 to 88.5 cm WD); females were significantly larger than males. Cross sections of vertebrae showed band-pairs ranging from 0 to > 14 in females and from 0 to 9 in males. New-borns presented an opaque edge at birth in vertebrae without a birthmark. The average percentage of error (APE; %E) for the entire sample provided evidence that ages were repeatable. The mean monthly marginal increment (IM) indicates annual band-pair formation from August to November. The annual cycle model for one band-pair deposition provided the best fit to data based on the AIC, with peaks between August and October, similar to that found in the IM analysis, suggesting an annual formation pattern. A multi-model approach that included four models based on the observed mean WD at age indicated a modified von Bertalanffy growth model as the best for describing the species growth: W0 (WD at birth) = 14.6 cm for both sexes; females W∞ = 98.61 cm (95% CI = 87.34–114.61 cm); k = 0.112 year−1 (CI = 0.086–0.148 year−1); males W∞ = 60.22 cm (CI = 55.66–65.35 cm); k = 0.219 year−1 (CI = 0.185–0.276 year−1). The age-at-maturity in males and females is 5 years and 7 years, respectively. The age composition shows that most (84%) specimens were aged 0 to 2 years. The information provided here is essential for analytical assessments of H. guttatus, which is subject to significant fishing pressure mainly on new-borns and juveniles. 相似文献
86.
Daniel Prá Silvia Isabel Rech Franke Raquel Giulian Maria Lúcia Yoneama Johnny Ferraz Dias Bernardo Erdtmann João Antonio Pêgas Henriques 《Biometals》2008,21(3):289-297
The toxicity of trace metals is still incompletely understood. We have previously shown that a single oral dose of iron or copper induces genotoxic effects in mice in vivo, as detected by single cell gel electrophoresis (comet assay). Here, we report the effect of these metals on subchronic exposure. Mice were gavaged for six consecutive days with either water, 33.2 mg/kg iron, or 8.5 mg/kg copper. On the 7th day, the neutral and alkaline comet assays in whole blood and the bone marrow micronucleus (MN) test were used as genotoxicity and mutagenicity endpoints, respectively. Particle induced X-ray emission was used to determine liver levels of the metals. Females showed a slightly lower DNA damage background, but there was no significant difference between genders for any endpoint. Iron and copper were genotoxic and mutagenic. While copper was more genotoxic in the neutral version, iron was more genotoxic in the alkaline version of the comet assay. Copper induced the highest mutagenicity as evaluated by the MN test. Iron was not mutagenic to male mice. Iron is thought to induce more oxidative lesions than copper, which are primarily detected in the alkaline comet assay. Treatment with iron, but not with copper, induced a significant increase in the hepatic level of the respective metal, reflecting different excretion strategies. 相似文献
87.
Scoaris Dde O Colacite J Nakamura CV Ueda-Nakamura T de Abreu Filho BA Dias Filho BP 《Antonie van Leeuwenhoek》2008,93(1-2):111-122
Aeromonas isolates from tap water, mineral water, and artesian well water were investigated for their ability to produce different
potential virulence factors or markers such as hemolysins, cytotoxins, phospholipase, DNase, hydrophobicity and their ability
to adhere to epithelial cells and to abiotic surfaces. The susceptibility to antibiotics of Aeromonas isolates was also examined. Majority of the isolates displayed hemolytic activity against sheep erythrocytes, while only
7 of the 23 Aeromonas strains displayed DNase activity and 4 of the 23 Aeromonas strains tested were regarded as positive for phospholipase production. Most of the isolates showed cytotoxic activities in
culture filtrate dilutions at titer of 1/8 or lower. No general relation between the strain isolated and the ability to interact
with epithelial cells could be established. Using the bacterial adherence to hydrocarbons method, most of the strains were
classified as highly hydrophilic. All five Aeromonas jandaei strains isolates, 9 of the 12 Aeromonas sp strains and four of the five Aeromonas hydrophila were multidrug resistant. The most active antimicrobial was ciprofloxacin (susceptible in 100% of the isolates), and the
least active antibiotic was ampicillin (resistance in 92% of the isolates). The majority of the isolates tested were not killed
by chlorine at 1.2 mg/l. Whether the high tolerance to chlorine of Aeromonas isolates can be linked to greater virulence is not know. 相似文献
88.
Most empirical and theoretical papers on prey–predator interactions are for animals with long-range detection, animals that can detect and react to predators long before these touch the prey. Heavy-bodied and chemically defended harvestmen (Arachnida, Opiliones) are an exception to this general pattern and rely on contact to detect arthropod predators. We examined the interactions between the Brazilian wandering spider Ctenus ornatus with harvestmen (Mischonyx cuspidatus) or control prey (Gryllus sp. and M. cuspidatus immature, both with soft integuments). Considering a prey–predator system in which fleeing from or reacting to a predator at a distance is not possible, we predicted both a high survival value of near-range defense mechanisms and that mortality would be higher in the absence of such defense mechanisms. We also expected the predator to behave differently when interacting with harvestmen or with a control prey without such defense mechanisms. Our results from laboratory experiments partially matched our predictions: First of all, histological sections showed that the integument of adult harvestmen is thicker than that of immature harvestmen and that of crickets. Adult harvestmen were less preyed upon than the control prey; the heavy armature increases the survival rate but the secretions from the scent glands do not. The predator did behave differently when attacking harvestmen compared to crickets. Despite the large size difference between predator and harvestmen, the protection provided by the armature allowed some of the harvestmen to survive encounters without pre-contact detection, thus greatly reducing the reliance on long-range detection to survive encounters with predators. Harvestmen call for theoretical and empirical work on prey–predator interactions that take into account the possibility that prey may not detect the predator before contact is established. 相似文献
89.
Andreia Miraldo Christiana Faria Godfrey M. Hewitt Octavio S. Paulo Brent C. Emerson 《Journal of Zoological Systematics and Evolutionary Research》2013,51(1):45-54
Measuring the diffusion of genes between diverging taxa through zones of secondary contact is an essential step to understand the extent and nature of the reproductive isolation that has been achieved. Previous studies have shown that the ocellated lizard (Lacerta lepida Daudin, 1802) has endured repeated range fragmentation associated with the climatic oscillations of the Plio‐Pleistocene that promoted diversification of many different evolutionary units within the species. However, the oldest divergence within the group is estimated to have occurred much earlier, during the Miocene, around 9 Ma and corresponds to the split between the subspecies Lacerta lepida nevadensis Buchholz (1963) and Lacerta lepida lepida Daudin (1802). Although these two evolutionary units have documented genetic and morphological differentiation, most probably accumulated during periods of allopatry, little is known about patterns of gene flow between them. In this study, we performed a population genetic analysis of a putative area of secondary contact between these two taxa, using mtDNA and microsatellite data. We assessed levels of gene flow across the contact zone to clarify to what extent gene flow may be occurring. Hybridization between the subspecies was observed by the presence of genetically introgressed individuals. However, the overall coincidence of mitochondrial and multilocus nuclear clines and generally steep clines support the idea that this contact zone is acting as a barrier to gene flow. Taken together, these results suggest that L. l. lepida and L. l. nevadensis are in independent evolutionary trajectories and should be considered as two different species. 相似文献
90.
Bacterial density and productivity were investigated along four salinity gradients within the estuary Ria de Aveiro. Bacterial
variables and environmental parameters were measured at three to four stations spanning the entire salinity gradient of the
four channels. The rather high variation in bacterial productivity (0.16–7.6 μg C L−1 h−1) along the profiles of salinity indicates that bacterial activity shows a reactive behavior to environmental changing. Bacterial
density (0.5–11.2 × 109 cells L−1) with a comparative smaller variation showed a more conservative behavior, mainly reflecting the phytoplankton distribution.
Contrary to expectation, minimal values of bacterial productivity were not observed in November–December but in June. In fact,
in November–December, the deep zone near the mouth showed the highest values of bacterial activity. At the upper stations,
the highest values were observed in October. The relatively high values of bacterial production during the cold rainy season
suggest that allochthonous substrates leached out from the surroundings by rain controlled the distribution of bacterial activity
in the estuarine system. The substantial decrease in salinity during the rainy season negatively affected bacterial productivity,
namely in the marine zone, where water column was highly stratified. Salinity seems to play an indirect role in the regulation
of estuarine bacteria because there are different bacterial communities adapted to a wide salinity range. 相似文献