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601.
Emilie Cornec-Le Gall Rory J. Olson Whitney Besse Christina M. Heyer Vladimir G. Gainullin Jessica M. Smith Marie-Pierre Audrézet Katharina Hopp Binu Porath Beili Shi Saurabh Baheti Sarah R. Senum Jennifer Arroyo Charles D. Madsen Claude Férec Dominique Joly François Jouret Oussamah Fikri-Benbrahim Peter C. Harris 《American journal of human genetics》2018,102(5):832-844
602.
J. G. Prunier B. Kaufmann S. Fenet D. Picard F. Pompanon P. Joly J. P. Lena 《Molecular ecology》2013,22(22):5516-5530
Genetic data are increasingly used in landscape ecology for the indirect assessment of functional connectivity, that is, the permeability of landscape to movements of organisms. Among available tools, matrix correlation analyses (e.g. Mantel tests or mixed models) are commonly used to test for the relationship between pairwise genetic distances and movement costs incurred by dispersing individuals. When organisms are spatially clustered, a population‐based sampling scheme (PSS) is usually performed, so that a large number of genotypes can be used to compute pairwise genetic distances on the basis of allelic frequencies. Because of financial constraints, this kind of sampling scheme implies a drastic reduction in the number of sampled aggregates, thereby reducing sampling coverage at the landscape level. We used matrix correlation analyses on simulated and empirical genetic data sets to investigate the efficiency of an individual‐based sampling scheme (ISS) in detecting isolation‐by‐distance and isolation‐by‐barrier patterns. Provided that pseudo‐replication issues are taken into account (e.g. through restricted permutations in Mantel tests), we showed that the use of interindividual measures of genotypic dissimilarity may efficiently replace interpopulation measures of genetic differentiation: the sampling of only three or four individuals per aggregate may be sufficient to efficiently detect specific genetic patterns in most situations. The ISS proved to be a promising methodological alternative to the more conventional PSS, offering much flexibility in the spatial design of sampling schemes and ensuring an optimal representativeness of landscape heterogeneity in data, with few aggregates left unsampled. Each strategy offering specific advantages, a combined use of both sampling schemes is discussed. 相似文献
603.
In vitro maturation of oocytes alters gene expression and signaling pathways in bovine cumulus cells
604.
Zhilan Hu Donglin Guo Shirley S.M. Yip Dejin Zhan Shahram Misaghi John C. Joly Bradley R. Snedecor Amy Y. Shen 《Biotechnology progress》2013,29(4):980-985
Therapeutic monoclonal antibodies (mAb) are often produced in Chinese hamster ovary (CHO) cells. Three commonly used CHO host cells for generating stable cell lines to produce therapeutic proteins are dihydrofolate reductase (DHFR) positive CHOK1, DHFR‐deficient DG44, and DUXB11‐based DHFR deficient CHO. Current Genentech commercial full‐length antibody products have all been produced in the DUXB11‐derived DHFR‐deficient CHO host. However, it has been challenging to develop stable cell lines producing an appreciable amount of antibody proteins in the DUXB11‐derived DHFR‐deficient CHO host for some antibody molecules and the CHOK1 host has been explored as an alternative approach. In this work, stable cell lines were developed for three antibody molecules in both DUXB11‐based and CHOK1 hosts. Results have shown that the best CHOK1 clones produce about 1 g/l for an antibody mAb1 and about 4 g/l for an antibody mAb2 in 14‐day fed batch cultures in shake flasks. In contrast, the DUXB11‐based host produced ~0.1 g/l for both antibodies in the same 14‐day fed batch shake flask production experiments. For an antibody mAb3, both CHOK1 and DUXB11 host cells can generate stable cell lines with the best clone in each host producing ~2.5 g/l. Additionally, studies have shown that the CHOK1 host cell has a larger endoplasmic reticulum and higher mitochondrial mass. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:980–985, 2013 相似文献
605.
The usual life cycle of Alpine newts comprises an aquatic larval stage and a terrestrial juvenile and adult stage. However,
some populations differ from this pattern in exhibiting facultative paedomorphosis where some individuals reach sexual maturity
while retaining larval traits such as gills and gill slits. While paedomorphic newts can, in some circumstances, initiate
metamorphosis, once a newt has commenced metamorphosis, the state is irreversible. Because the frequency of this switching
from one morph to the other has never been quantified in the wild, we attempted to estimate switching rate and survival by
carrying out a 3-year monitoring survey of a population inhabiting an alpine lake. While morph switching did occur in this
population, it involved a relatively low proportion of the paedomorphs (approx. 12%), suggesting that metamorphosis is not
favoured in the study population. The hypothesis of paedomorphic advantage was not supported since neither survival nor body
condition differed between morphs. The ontogenetic pathway of wild Alpine newts is thus characterised by two forks in the
developmental pathway. The first occurs during the larval stage (metamorphosis vs. paedomorphosis), and the second occurs
in paedomorphic adults (switching for metamorphosis vs. continuation of the paedomorphic lifestyle). Such a two-level decision
process may allow individuals to cope with environmental uncertainty. 相似文献
606.
607.
A 40-year-old divided highway does not prevent gene flow in the alpine newt Ichthyosaura alpestris 总被引:1,自引:0,他引:1
Jérôme G. Prunier Bernard Kaufmann Jean-Paul Léna Serge Fenet François Pompanon Pierre Joly 《Conservation Genetics》2014,15(2):453-468
Roads are of major concern in conservation biology, as they are known to restrict animal movements through landscape fragmentation, and may therefore impact genetic patterns in native terrestrial organisms. We assessed the effect of two large-scale transportation infrastructures (LTIs), a 40-year-old highway and a 30 year-old high-speed railway, on the spatial genetic structure of the alpine newt Ichthyosaura alpestris, a highly nomadic amphibian. Genetic data were gathered following a targeted individual-based sampling scheme and analysed using both overlay and correlative methods. While simulations suggested that the highway may be old enough for a significant barrier effect to be detected, LTIs were never detected as barriers to gene flow: inferred genetic boundaries rather coincided with transition zones between major landscape entities. Furthermore, spatial principal component analysis, a method designed to reveal cryptic genetic spatial patterns in high gene flow species, counter-intuitively suggested that the highway may act as a potential dispersal corridor in low-quality habitats, thus challenging traditional hypotheses on road impacts in amphibians. Our study showed that considering local interactions between species, infrastructures and landscape-specific characteristics is essential for better understanding the potential impacts of roads on movement patterns in terrestrial organisms. 相似文献
608.
Martin Gilbert Dale G. Miquelle John M. Goodrich Richard Reeve Sarah Cleaveland Louise Matthews Damien O. Joly 《PloS one》2014,9(10)
Lethal infections with canine distemper virus (CDV) have recently been diagnosed in Amur tigers (Panthera tigris altaica), but long-term implications for the population are unknown. This study evaluates the potential impact of CDV on a key tiger population in Sikhote-Alin Biosphere Zapovednik (SABZ), and assesses how CDV might influence the extinction potential of other tiger populations of varying sizes. An individual-based stochastic, SIRD (susceptible-infected-recovered/dead) model was used to simulate infection through predation of infected domestic dogs, and/or wild carnivores, and direct tiger-to-tiger transmission. CDV prevalence and effective contact based on published and observed data was used to define plausible low- and high-risk infection scenarios. CDV infection increased the 50-year extinction probability of tigers in SABZ by 6.3% to 55.8% compared to a control population, depending on risk scenario. The most significant factors influencing model outcome were virus prevalence in the reservoir population(s) and its effective contact rate with tigers. Adjustment of the mortality rate had a proportional impact, while inclusion of epizootic infection waves had negligible additional impact. Small populations were found to be disproportionately vulnerable to extinction through CDV infection. The 50-year extinction risk in populations consisting of 25 individuals was 1.65 times greater when CDV was present than that of control populations. The effects of density dependence do not protect an endangered population from the impacts of a multi-host pathogen, such as CDV, where they coexist with an abundant reservoir presenting a persistent threat. Awareness of CDV is a critical component of a successful tiger conservation management policy. 相似文献
609.
Patricia E. Reed Sabue Mulangu Kenneth N. Cameron Alain U. Ondzie Damien Joly Magdalena Bermejo Pierre Rouquet Giulia Fabozzi Michael Bailey Zhimin Shen Brandon F. Keele Beatrice Hahn William B. Karesh Nancy J. Sullivan 《PLoS neglected tropical diseases》2014,8(9)
Background
Central Africa is a “hotspot” for emerging infectious diseases (EIDs) of global and local importance, and a current outbreak of ebolavirus is affecting multiple countries simultaneously. Ebolavirus is suspected to have caused recent declines in resident great apes. While ebolavirus vaccines have been proposed as an intervention to protect apes, their effectiveness would be improved if we could diagnostically confirm Ebola virus disease (EVD) as the cause of die-offs, establish ebolavirus geographical distribution, identify immunologically naïve populations, and determine whether apes survive virus exposure.Methodology/Principal findings
Here we report the first successful noninvasive detection of antibodies against Ebola virus (EBOV) from wild ape feces. Using this method, we have been able to identify gorillas with antibodies to EBOV with an overall prevalence rate reaching 10% on average, demonstrating that EBOV exposure or infection is not uniformly lethal in this species. Furthermore, evidence of antibodies was identified in gorillas thought previously to be unexposed to EBOV (protected from exposure by rivers as topological barriers of transmission).Conclusions/Significance
Our new approach will contribute to a strategy to protect apes from future EBOV infections by early detection of increased incidence of exposure, by identifying immunologically naïve at-risk populations as potential targets for vaccination, and by providing a means to track vaccine efficacy if such intervention is deemed appropriate. Finally, since human EVD is linked to contact with infected wildlife carcasses, efforts aimed at identifying great ape outbreaks could have a profound impact on public health in local communities, where EBOV causes case-fatality rates of up to 88%. 相似文献610.
Shirley S. M. Yip Meixia Zhou John Joly Bradley Snedecor Amy Shen Yongping Crawford 《Molecular biotechnology》2014,56(9):833-838
Accumulation of high level of lactate can negatively impact cell growth during fed-batch culture process. In this study, we attempted to knockout the lactate dehydrogenase A (LDHA) gene in CHO cells in order to attenuate the lactate level. To prevent the potential deleterious effect of pyruvate accumulation, consequent to LDHA knockout, on cell culture, we chose a pyruvate dehydrogenase kinase 1, 2, and 3 (PDHK1, 2, and 3) knockdown cell line in which to knock out LDHA alleles. Around 3,000 clones were screened to obtain 152 mutants. Only heterozygous mutants were identified. An attempt to knockout the remaining wild-type allele from one such heterozygote yielded only two mutants after screening 567 clones. One had an extra valine. Another evidenced a duplication event, possessing at lease one wild-type and two different frameshifted alleles. Both mutants still retained LDH activity. Together, our data strongly suggest that a complete knockout of LDHA is lethal in CHO cells, despite simultaneous down-regulation of PDHK1, 2, and 3. 相似文献