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81.
Hartman EH Pikkemaat JA Vehof JW Heerschap A Jansen JA Spauwen PH 《Tissue engineering》2002,8(6):1029-1036
In animal studies of tissue engineering of bone, histology remains the standard for assessing bone formation. As longitudinal studies with this method are feasible only at the cost of large numbers of animals, we looked for an alternative. Therefore, demineralized bone matrix (DBM) and inactivated demineralized bone matrix (iDBM) implants were subcutaneously implanted in a rat. At 1, 3, 5, and 7 weeks postimplantation soft X-ray and magnetic resonance imaging (MRI) were done to monitor bone formation in the implants. At 7 weeks, the animal was killed and the implants were retrieved for histology. Our results showed that in vivo MRI is well suited to assess bone formation larger than 0.5 mm in diameter and to monitor the complete three-dimensional shape of the newly formed bone noninvasively and longitudinally. The MRI results matched well with the histology results obtained at 7 weeks. In contrast, X-ray imaging appeared inappropriate to monitor the bone formation process in DBM. 相似文献
82.
The phencyclidine (PCP) binding site of the N-methyl-D-aspartate receptor, the kainic acid (KA) receptor and the quisqualate (QA) receptor were visualised, using autoradiography in the human spinal cord and the distributions compared with that of benzodiazepine (BDZ) receptors and substance P (SP). All of the receptor types, and SP, were concentrated in lamina II of the dorsal horn, consistent with physiological data indicating that glutamate is a neurotransmitter of primary afferent terminals in the spinal cord. 相似文献
83.
The P-selectin gene is highly polymorphic: reduced frequency of the Pro715 allele carriers in patients with myocardial infarction 总被引:10,自引:3,他引:10
Herrmann SM; Ricard S; Nicaud V; Mallet C; Evans A; Ruidavets JB; Arveiler D; Luc G; Cambien F 《Human molecular genetics》1998,7(8):1277-1284
P-selectin is an adhesion molecule, expressed at the surface of activated
cells, that mediates the interaction of activated endothelial cells or
platelets with leukocytes. P-selectin expression is increased in
atherosclerotic plaques, and high plasma levels of this molecule have been
observed in patients with unstable angina. We investigated the P-selectin
gene as a possible candidate for myocardial infarction (MI). The P-selectin
gene is situated on chromosome 1q21-q24, spans >50 kb and contains 17
exons. The sequences of the 5'-flanking region and exons of 40 alleles from
patients with MI were screened for polymorphisms using polymerase chain
reaction/single-strand conformation polymorphism (PCR-SSCP) and sequencing.
Thirteen polymorphisms were identified: five in the 5'-flanking and eight
in the exonic sequences. Four polymorphisms (Ser290Asn, Asn562Asp,
Leu599Val and Thr715Pro) predicted a change in the amino acid sequence of
the P- selectin protein. All P-selectin polymorphisms as well as a common
E- selectin polymorphism, Ser128Arg which has been reported as being
associated with an increased risk of premature coronary heart disease
(CHD), and is in tight linkage disequilibrium with several P-selectin
polymorphisms, were investigated in 647 patients with MI and 758 control
subjects from four regions of France and Northern Ireland (the ECTIM
study). The entire set of P-selectin polymorphisms provided a
heterozygosity of 91%. The polymorphisms were tightly associated with one
another and displayed patterns of linkage disequilibrium suggesting the
existence of highly conserved ancestral haplotypes. The five polymorphisms
in the 5'-flanking region of the gene were unrelated to MI or any relevant
phenotype measured in the ECTIM study. We inferred that the four missense
variants identified in the coding region predicted eight common forms of
the P-selectin protein. The Pro715 allele which characterizes one of these
forms was less frequent in France than in Northern Ireland ( P < 0.002)
and in cases than in controls ( P < 0.002; P < 0.02 after correction
for the number of tests). We conclude that the P-selectin gene is highly
polymorphic and hypothesize that the Pro715 variant may be protective for
MI. Whether this variant affects the properties of the P-selectin protein
in a way which is compatible with this hypothesis needs to be checked
experimentally.
相似文献
84.
Sperm quality in Hodgkin's disease versus non-Hodgkin's lymphoma 总被引:3,自引:4,他引:3
Botchan A; Hauser R; Gamzu R; Yogev L; Lessing JB; Paz G; Yavetz H 《Human reproduction (Oxford, England)》1997,12(1):73-76
The study was conducted to determine the deleterious effect of lymphoma
disease on spermatogenesis and to evaluate the possibility that the disease
is mediated primarily by inherent mechanisms in Hodgkin's disease and
non-Hodgkin's lymphoma patients. A total of 89 patients with lymphoma
disease (Hodgkin's and non-Hodgkin's) were referred for sperm preservation
prior to adjuvant treatments. A comparison was made of pre- and post-thaw
sperm quality between lymphoma patients and healthy volunteers who applied
for sperm donation. This was followed by further assessment of the
differences between patients with Hodgkin's disease and non-Hodgkin's
lymphoma in terms of sperm variables, clinical parameters and blood hormone
concentrations. It was found that patients with lymphoma disease had
significantly impaired pre-freeze and post-thaw sperm quality compared with
that of healthy volunteers. Patients with non-Hodgkin's lymphoma had
spermatozoa of higher quality than patients with Hodgkin's disease. No
differences were found in the clinical or hormonal parameters between these
two groups. As expected, reduced testicular size and abnormal testicular
consistency were correlated with decreased sperm quality. The mere presence
of cancer disease has a direct negative effect on spermatogenesis, which is
probably not related to incidental side-effects. A variable degree of
impairment should be expected with different categories of cancer.
相似文献
85.
86.
T van der Poll C C Braxton S M Coyle M A Boermeester J C Wang P M Jansen W J Montegut S E Calvano C E Hack S F Lowry 《Infection and immunity》1995,63(9):3396-3400
Triglyceride-rich lipoproteins can inhibit endotoxin activity in vitro and in rodents. We sought to determine whether Intralipid, a triglyceride-rich fat emulsion which in contact with plasma functions similarly to endogenous lipoproteins, can alter the human response to endotoxin. Intralipid inhibited endotoxin-induced cytokine production in human whole blood in vitro in a dose-dependent manner, with maximal inhibition (up to 70%) being achieved at a concentration of 10 g/liter. In healthy men, a bolus intravenous injection of endotoxin (lot EC-5; 20 U/kg of body weight) was given midway through a 4-h infusion (125 ml/h) of either 5% glucose (n = 5) or 20% Intralipid (n = 5). The infusion of Intralipid led to an increase in triglyceride levels in serum from 95 +/- 16 to 818 +/- 135 mg/dl prior to endotoxin administration, i.e., levels that importantly reduced cytokine production in endotoxin-stimulated whole blood. However, in vivo hypertriglyceridemia did not influence inflammatory responses to endotoxin (fever, release of tumor necrosis factor and soluble tumor necrosis factor receptors, and leukocytosis) or even potentiated endotoxin responses (release of interleukins 6 and 8 and neutrophil degranulation). Hypertriglyceridemia does not inhibit the in vivo responses to endotoxin in humans. 相似文献
87.
A. C. Fluit J. T. van der Bruggen F. M. Aarestrup J. Verhoef W. T. M. Jansen 《Clinical microbiology and infection》2006,12(5):410-417
Antibiotic resistance is an increasing global problem. Surveillance studies are needed to monitor resistance development, to guide local empirical therapy, and to implement timely and adequate countermeasures. To achieve this, surveillance studies must have standardised methodologies, be longitudinal, and cover a sufficiently large and representative population. However, many fall short of these requirements that define good surveillance studies. Moreover, current efforts are dispersed among many, mostly small, initiatives with different objectives. These studies must be tailored to the various reservoirs of antibiotic-resistant bacteria, such as hospitalised patients, nursing homes, the community, animals and food. Two studies that could serve as examples of tailored programmes are the European Antimicrobial Resistance Surveillance System (EARSS), which collects resistance data during the diagnosis of hospitalised patients, and the DANMAP programme, which collects data in the veterinary sector. As already noted by the WHO, genetic studies that include both the typing of isolates and the characterisation of resistance determinants are necessary to understand fully the spread and development of antibiotic resistance. 相似文献
88.
89.
A. Burlet M. Chapleur-Chateau B. Haumont-Pellegri F. Jansen F. Menzaghi B. Fernette J.P. Nicolas C. Burlet 《Neuroscience》1992,50(4):965-973
We have previously demonstrated that vasopressin-producing neurons are the target of monoclonal antibodies to vasopressin microinjected into the brain tissue. At the same time, this central microinjection of vasopressin-monoclonal antibody into the supraoptic nuclei produced hydro-osmotic disorders mimicking the effects of a central diabetes insipidus. In order to investigate the increase in both duration and amplitude of the biological effects seen after the injection of vasopressin-monoclonal antibody, an immunoconjugate was constructed with the vasopressin-monoclonal antibody IgG1k isotype and the cytotoxic part of the ricin molecule, the ricin A chain. The biological parameters, such as diuresis and urine osmolality which are directly regulated by vasopressin, and vasopressin excretion, were measured after the central injection of this immunotoxin/immunoconjugate. The consequences of immunotoxin injection were also studied when immunotoxin was co-injected with monensin (50 nM) which has been shown to decrease the intracellular degradation of immunotoxin, and plasma complement, which has been shown to increase the neuronal uptake of immunotoxin. Single injection of immunotoxin near the hypothalamic supraoptic nuclei significantly increased diuresis and decreased vasopressin excretion. However, these effects were only transient and disappeared 24 h later. Four successive injections of immunotoxin (one per day) with monensin induced a decrease of vasopressin excretion which was still observed after a resting period of four days after the fourth injection. The long-term reduction of vasopressin excretion was induced in rats receiving four successive injections of a mixture consisting of immunotoxin with monensin and plasma complement. In such experiments, the vasopressin content of urine remained low (55% under the baseline value), two weeks after the fourth injection of immunotoxin. At the same time, the diuresis was increased (80% above the baseline value) and urine osmolality lowered (45% under the baseline value). When non-specific IgG replaced specific antibody, vasopressin excretion, diuresis as well as urine osmolality were unchanged.
The results of this study demonstrated that the use of a specific immunotoxin results in a local interference with the vasopressinergic neurons and induces a long-term reduction of vasopressin secretion. 相似文献
90.
A small T cell subpopulation expressing the phenotype Leu-5(CD2)+, Leu-4(CD3)+, Leu-1 (CD5)- can be found in peripheral blood and bone marrow of normal individuals. When these cells were sorted out by three colour immunofluorescence cell sorting and tested in limiting dilution assays, they were found to have lower frequencies of proliferating (9.0 +/- 5.6 times, n = 7) and of IL-2 producing cells (11.5 +/- 5.0 times n = 5), and a higher frequency of cytotoxic cells (3.1 +/- 2.6 times, n = 2) than T lymphocytes expressing the three markers. In peripheral blood lymphocytes, 1/3 of the CD3+, CD5- cells were positive for Leu-2a (CD8) while virtually all were negative for Leu-3a (CD4). Four colour flow cytometric analysis revealed a small subset of T cells positive for CD3 and negative for CD5, CD4 and CD8. Approximately 75% of the CD3+, CD5- cells were negative for Leu-7 and CD16 simultaneously. These results shed a light on the phenotype of T cells that escape killing by CD5 and complement in T cell depleted bone marrow and may explain why fewer residual T cells in the depleted marrow are detected by limiting dilution assays than by flow cytometric analysis. 相似文献