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101.
Perry JD Butterworth LA Nicholson A Appleby MR Orr KE 《Journal of clinical pathology》2003,56(7):528-531
AIMS: To compare the performance of a new chromogenic medium, Uriselect 4, with cystine lactose electrolyte deficient (CLED) agar and an established chromogenic agar, CPS ID 2 medium, for detection of urinary tract pathogens. METHODS: Using a semiquantitative culture method, 777 samples were inoculated on to the three test media in duplicate. All bacterial strains that yielded a potentially significant growth were observed for colony colour and identified using standard methods. RESULTS: Of the 777 samples tested, 589 urine samples yielded potentially significant growth of at least one strain. A total of 811 strains were isolated on at least one of the three media. A total of 168 urine samples yielded a mixture of at least two strains. Uriselect 4 medium showed the best sensitivity of the three media and only failed to recover 14 strains (1.7%). CPS ID 2 medium failed to recover 22 strains (2.7%). CLED medium showed the worst recovery and failed to recover 74 strains (9.1%). Both chromogenic media allowed for identification of Escherichia coli with a high degree of specificity (98% for Uriselect 4, 99.7% for CPS ID 2). Inclusion of a spot indole test increased the specificity of both chromogenic media to 100% for E coli. CONCLUSIONS: Uriselect 4 and CPS ID 2 were superior to CLED medium for the isolation of urinary tract pathogens mainly because of their ability to discriminate mixed cultures. Both chromogenic media were also useful for the preliminary identification of the most common urinary tract pathogens. 相似文献
102.
103.
104.
Computers in clinical assessment: historical developments, present status, and future challenges 总被引:3,自引:0,他引:3
Computerized testing methods have long been regarded as a potentially powerful asset for providing psychological assessment services. Ever since computers were first introduced and adapted to the field of assessment psychology in the 1950s, they have been a valuable aid for scoring, data processing, and even interpretation of test results. The history and status of computer-based personality and neuropsychological tests are discussed in this article. Several pertinent issues involved in providing test interpretation by computer are highlighted. Advances in computer-based test use, such as computerized adaptive testing, are described and problems noted. Today, there is great interest in expanding the availability of psychological assessment applications on the Internet. Although these applications show great promise, there are a number of problems associated with providing psychological tests on the Internet that need to be addressed by psychologists before the Internet can become a major medium for psychological service delivery. 相似文献
105.
Dynamic responses of oxygen uptake at the onset and end of moderate and heavy exercise in trained subjects. 总被引:1,自引:0,他引:1
Christophe Cleuziou Stéphane Perry Fabio Borrani Anne Marie Lecoq Robin Candau Daniel Courteix Philippe Obert 《Revue canadienne de physiologie appliquée》2004,29(1):32-44
Inconsistencies about dynamic asymmetry between the on- and off-transient responses in VO2 are found in the literature. Therefore the purpose of this study was to examine VO2 on- and off-transients during moderate- and heavy-intensity cycling exercise in trained subjects. Ten men underwent an initial incremental test for the estimation of ventilatory threshold (VT) and, on different days, two bouts of square-wave exercise at moderate (VT) intensities. VO2 kinetics in exercise and recovery were better described by a single exponential model (VT). For moderate exercise, we found a symmetry of VO2 kinetics between the on- and off-transients (i.e., fundamental component), consistent with a system manifesting linear control dynamics. For heavy exercise, a slow component superimposed on the fundamental phase was expressed in both the exercise and recovery, with similar parameter estimates. But the on-transient values of the time constant were appreciably faster than the associated off-transient, and independent of the work rate imposed (VT). Our results do not support a dynamically linear system model of VO2 during cycling exercise in the heavy-intensity domain. 相似文献
106.
Jon D Larson Shannon A Wadman Eleanor Chen Lesa Kerley Karl J Clark Mark Eide Sarah Lippert Aidas Nasevicius Stephen C Ekker Perry B Hackett Jeffrey J Essner 《Developmental dynamics》2004,231(1):204-213
We have identified the zebrafish homologue of VE-cadherin and documented its expression in the developing vascular system. The zebrafish VE-cadherin gene is specifically expressed in the vascular endothelial cell lineage beginning with the differentiation and migration of angioblasts and persists throughout vasculogenesis, angiogenesis, and endocardium development. Staining zebrafish embryos by whole-mount in situ hybridization with the VE-cadherin probe provides a method to screen embryos for vascular defects. To illustrate this utility, we used VE-cadherin expression to demonstrate a conservation of vascular endothelial growth factor-A (VEGF-A) function. The morpholino antisense oligonucleotide knockdown of VEGF-A function in zebrafish embryos results in a loss of angiogenic blood vessels, as indicated by the lack of VE-cadherin expression in the intersegmental vasculature. This loss can be restored in embryos supplemented with either zebrafish or human VEGF-A, the latter indicating that genes crucial to angiogenesis have highly conserved functional activities in vertebrates. 相似文献
107.
Aliev G Castellani RJ Petersen RB Burnstock G Perry G Smith MA 《Journal of submicroscopic cytology and pathology》2004,36(3-4):225-240
Many factors play a role in the development of atherosclerotic lesions. One of the leading risk factors for development of atherosclerosis is familial hypercholesterolemia (FH). FH is a genetic disease characterized by a deficiency, and/or mutation, of receptors for low density lipoprotein (LDL) on the plasmalemma of endothelial cells (EC), a high level of low density lipoprotein in the plasma, and early, spontaneous development of atherosclerosis and skin xanthoma. In this review we describe Watanabe heritable hyperlipidemic (WHHL) rabbits, which represent such an animal model for human FH. This strain of the rabbits is characterized by a genetic deficiency or mutation of functional LDL receptors and develops severe atherosclerosis, which is pathologically similar to familial homozygous hyperlipidemic patients. The most completely characterized animal model is the Watanabe rabbit, a model of homozygous and heterozygous type IIa hypercholesterolemia related to an LDL receptor deficiency. Additional manipulation such as aortic injury in this rabbit model induces the development of atherosclerotic lesions that are structurally similar to those found in humans. Thus, this model of hypercholesterolemia fulfils the above criteria set, i.e. it is able to provide new insights for a better understanding of the pathogenesis of atherosclerosis and for testing new treatment strategies. 相似文献
108.
109.
Joensen L Borda E Kohout T Perry S García G Sterin-Borda L 《Molecular and biochemical parasitology》2003,127(2):169-177
Previously, we have demonstrated that plasma membranes from the parasite Trypanosoma cruzi (T. cruzi) recognize and adhere to host cells through parasite surface attachment molecules that have affinity for beta(1)-adrenergic receptors (beta(1)-ARs) on target organs. In this report we identify a parasite protein that not only interacts with beta(1)-ARs, but also displays beta-agonist-like activity. We demonstrate that a recombinant maltose binding protein fusion of Tc13 Tul (MBP-Tc13 Tul), a member of the T. cruzi antigen 13 family of surface antigen proteins, competes for binding sites with the beta-adrenergic receptor antagonist [125I]-CYP on membranes purified both from CHO cells expressing human beta(1)-ARs and from rat atria. The competition is prevented by pre-treating MBP-Tc13 Tul with antibodies directed against the EPKSA repeat domain of Tc13 Tul, implicating this portion of the molecule in binding to the beta(1)-AR. Furthermore, MBP-Tc13 Tul activates rat myocardial beta(1)-ARs, resulting in synthesis of cyclic adenosine monophosphate (cAMP) and an increase in cardiac contractility. These biological effects are selectively suppressed by the beta(1)-AR antagonist atenolol, by a synthetic peptide corresponding to the second extracellular loop of the human beta(1)-AR, and by the anti-EPKSA repeat antibodies. These results imply that the Tc13 Tul cell-surface antigen of T. cruzi plays a central role in misregulating the beta(1)-AR following parasite infection, and may be a causative factor of dysautonomic syndrome described in Chagas' disease. 相似文献
110.
A discrete-time kinetic model for chemotherapy was developed to deal with the effects of antitumor drugs on the cell cycle
and proliferation kinetics of experimental tumor cell populations in which cell kinetic responses of chemotherapy are represented
in terms of perturbation of cell kinetic parameters—cell age, cell size and DNA content distributions. The time-course behavior
of these cell kinetic parameters was predicted by solving the discrete-time state equations which characterize the dynamics
of tumor-drug interactions. The amount of antitumor drug administered was expressed to be the control function of the state
equations and the transition matrix representing two modes of drug action, namely, cell kill and progression delay or accumulation
of cells due to drug, was derived. The performance of the model, assessed by examining the effects of cell cycle stage-specific
agents such as cytosine arabinoside on spontaneous AKR leukemia, compared favorably with experimental data. Utilizing an optimization
scheme in engineering systems studies, an analytical method is described for optimizing the regimen of drug administration
so as to maximize the effectiveness of drug dosage schedules and minimize the use of toxic amounts of the drug. The superiority
of the schedule designed by an optimization scheme was evident at the termination of therapy, although the schedule designed
by experimental trials reduced the number of surviving tumor cells more effectively than the one designed by an optimization
scheme during the earlier therapy period. In the model, the proposed schedule will function more effectively for the entire
therapy period when additional parameters of drug characteristics, such as the toxicity to the host and drug resistance, are
encompassed. 相似文献