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51.
Summary Normal sexual development is the consequence of three sequential interrelated processes: establishment of genetic, gonadal and somatic sex. It is the terminal phase of sexual differentiation-the translation of gonadal into somatic sex, which is governed by the presence or absence of both testosterone and Müllerian-inhibiting hormone and of dihydrotestosterone, which is formed in its respective target tissues. Thus, despite a testis, somatic male sexual differentiation will proceed to a normal male phenotype only if all three hormones are synthesized and act during a critical period of uterine development. Many clinically distinct syndromes are the results of abnormalities in the synthesis or action of the above-mentioned hormones; these syndromes are described in detail. In contrast to male somatic differentiation, female somatic development is independent of these hormones.
Abkürzungen DHT 5-Dihydrotestosteron - HY-Antigen Histocompatibilitätsantigen-Y - MIH Müllerian-Inhibiting-Hormon - SSW Schwangerschaftswoche Die eigenen Untersuchungen wurden durch die Deutsche Forschungsgemeinschaft Schw 168/5–7 unterstützt 相似文献
Abkürzungen DHT 5-Dihydrotestosteron - HY-Antigen Histocompatibilitätsantigen-Y - MIH Müllerian-Inhibiting-Hormon - SSW Schwangerschaftswoche Die eigenen Untersuchungen wurden durch die Deutsche Forschungsgemeinschaft Schw 168/5–7 unterstützt 相似文献
52.
House dust mite-specific T cells in the skin of subjects with atopic dermatitis: frequency and lymphokine profile in the allergen patch test. 总被引:15,自引:0,他引:15
N Sager A Feldmann G Schilling P Kreitsch C Neumann 《The Journal of allergy and clinical immunology》1992,89(4):801-810
The mechanism underlying positive patch tests with house dust mite-allergen, Dermatophagoides pteronyssinus (Der p), in patients with atopic dermatitis was investigated by isolating T cells from the test sites of two patients. Eighty-five T cell clones (TCC) were established from the epidermis and dermis of lesional skin by the limiting-dilution method with Der p and interleukin (IL)-2. With restimulation assays, 29 of 60 TCCs tested demonstrated specific proliferation; 85% were of the CD3+, CD2+, and CD4+ phenotype. Der p-specific T cells constituted 0.4% to 2.7% of lesional T cells, and they were more frequent in the skin than in the blood of the patients by one order of magnitude. The mitogen-stimulated lymphokine profile of 55 TCCs was assessed; 42% (11/26) of the allergen-specific TCCs secreted IL-4 but almost no interferon-gamma, as described for the Th2 subset of the mouse. Also, six selected TCCs supported IgE secretion by autologous lymphocytes. Only three of 26 allergen-specific, skin-derived TCCs demonstrated a Th1-like lymphokine profile. These results support the specific nature of Der p-induced patch test lesions in patients with atopic dermatitis, and the results demonstrate also that a considerable proportion of lesional T cells are allergen-specific, IL-4-producing T cells that are capable of enhancing IgE production. 相似文献
53.
Effects of serine/threonine protein phosphatases on ion channels in excitable membranes 总被引:25,自引:0,他引:25
This review deals with the influence of serine/threonine-specific protein phosphatases on the function of ion channels in the plasma membrane of excitable tissues. Particular focus is given to developments of the past decade. Most of the electrophysiological experiments have been performed with protein phosphatase inhibitors. Therefore, a synopsis is required incorporating issues from biochemistry, pharmacology, and electrophysiology. First, we summarize the structural and biochemical properties of protein phosphatase (types 1, 2A, 2B, 2C, and 3-7) catalytic subunits and their regulatory subunits. Then the available pharmacological tools (protein inhibitors, nonprotein inhibitors, and activators) are introduced. The use of these inhibitors is discussed based on their biochemical selectivity and a number of methodological caveats. The next section reviews the effects of these tools on various classes of ion channels (i.e., voltage-gated Ca(2+) and Na(+) channels, various K(+) channels, ligand-gated channels, and anion channels). We delineate in which cases a direct interaction between a protein phosphatase and a given channel has been proven and where a more complex regulation is likely involved. Finally, we present ideas for future research and possible pathophysiological implications. 相似文献
54.
Rabbit retinal Müller cells were isolated by means of papaine and mechanical dissociation. These cells were shown to have a well preserved morphology and to preserve viability for many hours. Intense wheat germ agglutinin binding occurs on the photoreceptor side of Müller cells, especially in the microvillous region. Rabbit retinal Müller cells have a Na+,K+-activated adenosine triphosphatase activity in the same order of magnitude as brain astroglial cells. 相似文献
55.
Cary-Blair, a transport medium for Vibrio parahemolyticus 总被引:2,自引:0,他引:2
56.
Y chromosome microdeletions, in azoospermic or near-azoospermic subjects, are located in the AZFc (DAZ) subregion 总被引:9,自引:2,他引:9
Submicroscopic deletions of the Y chromosome and polymorphisms of the
androgen receptor (AR) gene in the X chromosome have been observed in men
with defective spermatogenesis. To further define the subregions/genes in
the Y chromosome causing male infertility and its relationship to
polymorphisms of the AR polyglutamine tract, we screened the genomic DNA of
202 subfertile males and 101 healthy fertile controls of predominantly
Chinese ethnic origin. Y microdeletions were examined with 16
sequence-tagged site (STS) probes, including the RBM and DAZ genes,
spanning the AZFb and AZFc subregions of Yq11, and related to the size of
trinucleotide repeat encoding the AR polyglutamine tract. Y microdeletions
were detected and confirmed in three out of 44 (6.8%) of azoospermic and
three out of 86 (3.5%) severely oligozoospermic patients. No deletions were
detected in any of the patients with sperm counts of >0.5 x 10(6)/ml,
nor in any of the 101 fertile controls. All six affected patients had
almost contiguous Y microdeletions spanning the entire AZFc region
including the DAZ gene. The AZFb region, containing the RBM1 gene, was
intact in five of the six subjects. Y deletions were not found in those
with long AR polyglutamine tracts. Our study, the first in a Chinese
population, suggest a cause and effect relationship between Y
microdeletions in the AZFc region (possibly DAZ), and azoospermia or
near-azoospermia. Y microdeletions and long AR polyglutamine tracts appear
to be independent contributors to male infertility.
相似文献
57.
Determination of the parent of origin in nine cases of prenatally detected chromosome aberrations found after intracytoplasmic sperm injection 总被引:1,自引:17,他引:1
Van Opstal D; Los FJ; Ramlakhan S; Van Hemel JO; Van Den Ouweland AM; Brandenburg H; Pieters MH; Verhoeff A; Vermeer MC; Dhont M; In't Veld PA 《Human reproduction (Oxford, England)》1997,12(4):682-686
Prenatal cytogenetic analysis of 71 fetuses conceived by intracytoplasmic
sperm injection (ICSI) resulted in the detection of nine (12.7%) chromosome
aberrations including two cases of 47,XXY, four cases involving a 45,X cell
line and three autosomal trisomies. Molecular analysis of the parental
origin of the deleted or supernumerary chromosome was performed by using
polymorphic microsatellite markers. Six cases involving a sex chromosome
abnormality were found to be of paternal origin while the two trisomic
cases that could be analysed were of maternal origin. Two cases involved
the same infertile couple who had two consecutive ICSI pregnancies
terminated because of a chromosome abnormality. The replaced embryos in
both cases originated from a single batch of ICSI fertilized oocytes of
which part was used to initiate the first pregnancy and part was
cryopreserved and used to initiate the second pregnancy.
相似文献
58.
Billette J; Janse MJ; van Capelle FJ; Anderson RH; Touboul P; Durrer D 《The American journal of physiology》1976,231(4):1129-1139
59.
T-cell antigenic sites involved in myasthenia gravis: correlations with antibody titre and disease severity 总被引:1,自引:0,他引:1
S Berrih-Aknin S Cohen-Kaminsky V Lepage D Neumann J F Bach S Fuchs 《Journal of autoimmunity》1991,4(1):137-153
We have evaluated the ability of eight synthetic peptides corresponding to selected regions of the alpha-subunit from human (H) or Torpedo (T) acetylcholine receptor (AChR) to stimulate proliferative responses of peripheral blood lymphocytes (PBL) and thymic cells from patients with Myasthenia Gravis (MG) in comparison to healthy controls. Using PBL, two of the peptides were most reactive: in the 40 myasthenic patients tested, peptide 169-181 (H) induced significant proliferative responses in 10 patients and peptide 351-368 (H) in five, while there was no response in any of the 34 healthy controls tested. Interestingly, clear associations between proliferation to peptides and clinical data were observed. Indeed, among responding patients, all presented thymic hyperplasia and most showed a high anti-AChR Ab titre and/or a severe form of the disease. In addition, responses to AChR cytoplasmic sequences were observed only in severely affected patients. Correlation with HLA-DR haplotype, sought in a subgroup of patients, indicated that response to 169-181 (H) is associated with HLA-DR5 in the patients presenting a high anti-AChR antibody titre. Using thymic lymphocytes, few responses were obtained with the human peptides, suggesting that the frequency of autoreactive cells is lower than in the blood. Similar to PBL, responses to peptides were observed only with lymphocytes isolated from hyperplastic thymuses. The correlations observed between responses to peptides and clinical parameters underline the pathophysiological relevance of our data and indicate that pathogenic and nonpathogenic T-cell antigenic sites involved in the anti-AChR response could be identified by this approach. 相似文献
60.
Beta2-adrenergic receptors mediate the differential effects of catecholamines on cytokine production of PBMC. 总被引:1,自引:0,他引:1
M Wahle R P Neumann F Moritz A Krause F Buttgereit C G O Baerwald 《Journal of interferon & cytokine research》2005,25(7):384-394
We determined characteristics of beta2-adrenergic receptors (beta2R) on peripheral blood mononuclear cells (PBMC) and cytokine production after mitogenic stimulation and coincubation with catecholamines. PBMCs were stimulated with interleukin-2 (IL-2), tetanus toxoid (TT), anti-CD3 antibody, or phytohemagglutinin (PHA). The cytokines interferon-gamma (IFN-gamma), IL-4, and IL-6 were determined by ELISA following coincubation with high-dose (10(-5) M) and low-dose (10(-9) M) epinephrine (EPI) and norepinephrine (NE). Intracellular IFN-gamma and IL-4 were studied by FACS analysis. The beta2R density was investigated using a radioligand binding assay. The stimuli induced various cytokine profiles in PBMCs. Synthesis of IFN-gamma was induced by all mitogens and could be suppressed by catecholamines (26%-85% reduction). In PHA-stimulated PBMCs, IL-4 synthesis was decreased by high-dose catecholamines (24%-28% reduction). Adding a beta-blocking agent attenuated most catecholamine effects. A highly significant negative correlation between the density of beta2R with IFN-gamma and IL-6 levels of PHA-activated PBMCs (r = -0.88 to -0.96, p < 0.01-< 0.001) was observed. The results indicate that the density of beta2R on PBMC plays a role in mediating the differential catecholamine effects on cytokine production of PBMC. Furthermore, changes in cytokine expression induced by catecholamines favor Th2 responses. 相似文献