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1.
The fungus Eutypa lata (syn. E. armeniacae), known as the causal agent of the death of many different woody plants, was found on dead branches of pistachio (Pistacia vera L.) in Greece. Isolations from diseased branches yielded consistently typical colonies of the asexual stage of the fungus (Libertella blepharis, syn. Cytosporina sp.), which proved to be undistinguishable from other cultures of the pathogen obtained from 15 different hosts. Furthermore, all isolates from pistachio tested for pathogenicity on apricot were pathogenic and yielded characteristic cankers. 相似文献
2.
Ingo Marenholz Armin Volz Andreas Ziegler Angela Davies Ioannis Ragoussis Bernhard P. Korge Dietmar Mischke 《Genomics》1996,37(3):295
The epidermal differentiation complex (EDC) unites a remarkable number of structurally, functionally, and evolutionarily related genes that play an important role in terminal differentiation of the human epidermis. It is localized within 2.05 Mb of region q21 on human chromosome 1. We have identified and characterized 24 yeast artificial chromosome (YAC) clones by mapping individual EDC genes, sequence-tagged site (STS) markers (D1S305, D1S442, D1S498, D1S1664), and 10 new region-specific probes (D1S3619–D1S3628). Here we present a contig that covers about 6 Mb of 1q21 including the entire EDC. Fluorescencein situhybridization on metaphase chromosomes with two YACs flanking the EDC determined its chromosomal orientation and established, in conjunction with physical mapping results, the following order of genes and STSs: 1cen–D1S442–D1S498–S100A10–THH–FLG–D1S1664–IVL–SPRR3–SPRR1–SPRR2–LOR–S100A9–S100A8–S100A7–S100A6–S100A5–S100A4–S100A3–S100A2–S100A1–D1S305–1qtel. These integrated physical, cytogenetic, and genetic mapping data will be useful for linkage analyses of diseases associated with region 1q21 and for the identification of novel genes and regulatory elements in the EDC. 相似文献
3.
Rob J. De Boer Alan S. Perelson Ioannis G. Kevrekidis 《Bulletin of mathematical biology》1993,55(4):781-816
Two types of behavior have been previously reported in models of immune networks. The typical behavior of simple models, which
involve B cells only, is stationary behavior involving several steady states. Finite amplitude perturbations may cause the
model to switch between different equilibria. The typical behavior of more realistic models, which involve both B cells and
antibody, consists of autonomous oscillations and/or chaos. While stationary behavior leads to easy interpretations in terms
of idiotypic memory, oscillatory behavior seems to be in better agreement with experimental data obtained in unimmunized animals.
Here we study a series of models of the idiotypic interaction between two B cell clones. The models differ with respect to
the incorporation of antibodies, B cell maturation and compartmentalization. The most complicated model in the series has
two realistic parameter regimes in which the behavior is respectively stationary and chaotic. The stability of the equilibrium
states and the structure and interactions of the stable and unstable manifolds of the saddle-type equilibria turn out to be
factors influencing the model's behavior. Whether or not the model is able to attain any form of sustained oscillatory behavior,
i.e. limit cycles or chaos, seems to be determined by (global) bifurcations involving the stable and unstable manifolds of
the equilibrium states. We attempt to determine whether such behavior should be expected to be attained from reasonable initial
conditions by incorporating an immune response to an antigen in the model. A comparison of the behavior of the model with
experimental data from the literature provides suggestions for the parameter regime in which the immune system is operating. 相似文献
4.
Ioannis Dragatsis Christine Zioudrou Kyriaki Gerozissis 《Cellular and molecular neurobiology》1995,15(4):389-400
Summary 1. Inin vitro studies with adult male rats we have recently shown that the delta-opioid agonist DTLET inhibits the release of the Gonadotropin-Releasing Hormone (GnRH) from hypothalamic fragments containing the arcuate nucleus and the median eminence. This effect is receptor mediated and eicosanoid dependent (Gerozissiset al., 1993).2. In the present study we report that the delta-opioid antagonists with negative intrinsic activity, Diallyl-G and ICI 174864, applied under the same experimental conditions (30 min static incubations at 37°C, in a potassium rich milieu), in the absence of the agonist DTLET, also exert a similar to the agonist inhibitory effect on the release of GnRH.3. The dose-dependent inhibitory effect of Diallyl-G on GnRH release is reversed by increasing concentrations of DTLET. The mu and delta opioid antagonist, naloxone is without effect in the absence of DTLET. However, naloxone acts as an antagonist on the Diallyl-G-induced inhibition of GnRH release.4. Diallyl-G also inhibits the release of prostaglandin E2 (PGE2). In the presence of indomethacin or nordihydroguaiaretic acid, Diallyl-G is ineffective to further inhibit the release of GnRH. These latter observations taken together with the results of eicosanoid estimation suggest that PGE2 but not leukotrienes participate in the agonist-independent effects of Diallyl-G on GnRH release.5. Therefore these results support the hypothesis that delta-opioid antagonists with negative intrinsic activity exert agonist-independent biological responses similar to those of the agonists. 相似文献
5.
6.
Ioannis A. Voutsadakis 《Molecular biology reports》2013,40(2):2019-2034
Breast cancer is the most common malignancy in women and a significant cause of morbidity and mortality. Sub-types of breast cancer defined by the expression of steroid hormones and Her2/Neu oncogene have distinct prognosis and undergo different therapies. Besides differing in their phenotype, sub-types of breast cancer display various molecular lesions that participate in their pathogenesis. BRCA1 is one of the common hereditary cancer predisposition genes and encodes for an ubiquitin ligase. Ubiquitin ligases or E3 enzymes participate together with ubiquitin activating enzyme and ubiquitin conjugating enzymes in the attachment of ubiquitin (ubiquitination) in target proteins. Ubiquitination is a post-translational modification regulating multiple cell functions. It also plays important roles in carcinogenesis in general and in breast carcinogenesis in particular. Ubiquitin conjugating enzymes are a central component of the ubiquitination machinery and are often perturbed in breast cancer. This paper will discuss ubiquitin and ubiquitin-like proteins conjugating enzymes participating in breast cancer pathogenesis, their relationships with other proteins of the ubiquitination machinery and their role in phenotype of breast cancer sub-types. 相似文献
7.
8.
Pasqualina Woodrow Giovanni Pontecorvo Stefania Fantaccione Amodio Fuggi Ioannis Kafantaris Danila Parisi Petronia Carillo 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2010,121(2):311-322
Long terminal repeat retrotransposons are the most abundant mobile elements in the plant genome and play an important role in the genome reorganization induced by environmental challenges. Their success depends on the ability of their promoters to respond to different signaling pathways that regulate plant adaptation to biotic and abiotic stresses. We have isolated a new Ty1-copia-like retrotransposon, named Ttd1a from the Triticum durum L. genome. To get insight into stress activation pathways in Ttd1a, we investigated the effect of salt and light stresses by RT-PCR and S-SAP profiling. We screened for Ttd1a insertion polymorphisms in plants grown to stress and showed that one new insertion was located near the resistance gene. Our analysis showed that the activation and mobilization of Ttd1a was controlled by salt and light stresses, which strengthened the hypothesis that stress mobilization of this element might play a role in the defense response to environmental stresses. 相似文献
9.
Nakayama EE Carpentier W Costagliola D Shioda T Iwamoto A Debre P Yoshimura K Autran B Matsushita S Theodorou I 《Immunogenetics》2007,59(6):511-515
Polymorphisms in human genes have been shown to affect the rate of disease progression to acquired immune deficiency syndrome
in human immunodeficiency virus type 1 (HIV-1)-infected individuals. Recently, tripartite motif 5α (TRIM5α) was identified
as a factor that confers resistance to HIV-1 infection in Old World monkey cells. Subsequently, Sawyer et al. (Curr Biol 16:95–100,
2006) reported a single nucleotide polymorphism (H43Y) in the human TRIM5α gene and TRIM5α protein with 43Y was found to lose its ability to restrict HIV-1. In the present study, we reevaluated effects
of this allele on in vitro anti-HIV-1 activity as well as on HIV-1 disease progression in European and Asian cohorts of HIV-1-infected
individuals. Our epidemiological and molecular biological findings clearly indicate H43Y has a very minor effect on anti-HIV-1
activity of TRIM5α, suggesting that this allele is immaterial, at least in HIV-1-infected Europeans and Asians. 相似文献
10.
Kalogianni DP Litos IK Christopoulos TK Ioannou PC 《Biosensors & bioelectronics》2009,24(6):1811-1815
In recent years, there is a continuously growing interest in the development of biosensors for rapid, simple and inexpensive DNA tests suitable for the small laboratory or for on-site testing. Detection is accomplished through electrochemical, optical or gravimetric transduction. We report on the development of disposable dipstick-type DNA biosensors that employ oligonucleotide-decorated colored polystyrene microspheres as reporters and enable visual detection of DNA sequences without the use of instrumentation. The biosensors have been designed to detect DNA molecules that contain both, a biotin moiety and a segment that is complementary to the oligonucleotide attached on the surface of blue or red microspheres. Capture of the hybrids by immobilized streptavidin at the test zone results in the formation of a colored line. The biosensors were applied to: (a) detection of single-stranded DNA, (b) detection of PCR-amplified double-stranded DNA and (c) genotyping of single nucleotide polymorphisms (SNP). The results were compared with sensors based on gold nanoparticle reporters. It is also demonstrated that the microspheres offer the potential for multicolor detection of specific DNA sequences. 相似文献