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51.
Frieden J 《Business and health》1992,10(6):34-5, 38, 40-2
The Netherlands provides universal access and high-quality care, but the Dutch are reforming their system to encourage more competition among insurers. 相似文献
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53.
C R Driver T R Frieden A B Bloch I M Onorato 《Public health reports (Washington, D.C. : 1974)》1994,109(5):632-636
The authors assessed drug susceptibility patterns among tuberculosis patients reported to the New York City Department of Health in the first quarters of 1991 and 1992. Resistance to one or more drugs was seen in 26 percent (137 divided by 520) in 1991 and 24 percent (122 divided by 517) in 1992. Resistance to isoniazid was seen in 22 percent and 19 percent of patients in 1991 and 1992, respectively; resistance to rifampin in 15 percent and 14 percent; and to both isoniazid and rifampin in 15 percent and 14 percent. Combined resistance to four first line drugs (isoniazid, rifampin, streptomycin, and ethambutol) was seen in 6 percent (1991) and 8 percent (1992). Patients with organisms resistant to both isoniazid and rifampin were as likely among U.S. born as among foreign born, and younger patients were more likely than older patients to have isoniazid and rifampin resistant organisms. These findings underscore the importance of obtaining susceptibility testing in all patients who have cultures positive for Mycobacterium tuberculosis. 相似文献
54.
Invasive infections with group A beta-hemolytic streptococci became less common in the early 20th century prior to the widespread use of antibiotics. From the early 1960s until the mid-1980s, reports of invasive infections continued to decline. In the past 5 years, there has been a resurgence of invasive infections and, possibly, also of postinfectious sequelae from this organism. We describe a patient with lung abscess from group A beta-hemolytic Streptococcus. Lung abscess from hemolytic streptococci was not uncommon in Osler's day, but it was not reported in the English-language literature for 20 years until recently. Clinicians should be aware of the broad and growing spectrum of infections with this pathogen. 相似文献
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57.
Rapid mobilization of hematopoietic progenitor cells in rhesus monkeys by a single intravenous injection of interleukin-8 总被引:13,自引:6,他引:13
Laterveer L; Lindley IJ; Heemskerk DP; Camps JA; Pauwels EK; Willemze R; Fibbe WE 《Blood》1996,87(2):781-788
Interleukin-8 (IL-8) is a chemoattractant cytokine involved in chemotaxis and activation of neutrophils. Because in vivo administration of IL-8 induces mobilization of hematopoietic stem cells in mice, we assessed the mobilizing properties of IL-8 in rhesus monkeys. Recombinant human IL-8 was administered as a single intravenous injection at doses of 10, 30, and 100 micrograms/kg to rhesus monkeys (age, 2 to 3 years; weight, 2.5 to 4.5 kg). Venous blood samples were obtained at time intervals ranging from 1 to 480 minutes after IL-8 administration. Cell counts, colony-forming unit-Mix assays, and fluorescence-activated cell sorter analysis were performed. Plasma was harvested to assess IL-8 levels. A time-controlled bolus intravenous injection of 100 micrograms IL-8 per kilogram of body weight resulted in peak IL-8 plasma levels up to 5 micrograms/mL. The calculated half-time life of free IL-8 was 9.9 +/- 2.2 minutes. IL-8 injection resulted in instant neutropenia that was due to pulmonary sequestration, as shown using 99mTc-labeled leukocytes. Within 30 minutes after IL-8 injection, neutrophilia developed with counts up to 10-fold greater than baseline levels. The numbers of hematopoietic progenitor cells (HPCs) increased from 45 +/- 48/mL to 1,382 +/- 599/mL of blood at 30 minutes after injection of 100 micrograms IL-8 per kilogram of bodyweight (mean +/- SD, n = 8). Individual animals showed 10- to 100-fold increase in numbers of circulating HPCs that returned to almost pretreatment values (92 +/- 52 CFU/mL) at 240 minutes after the injection of IL-8. Immunophenotyping showed no significant changes in lymphocyte (sub)populations. A second bolus injection of IL-8 with an interval of 72 hours resulted in similar numbers of mobilized stem cells as observed after the first injection, showing that no tachyphylaxis had occurred. We conclude that IL-8 induces mobilization of HPCs from the bone marrow of rhesus monkeys in a rapid and reproducible fashion. Therefore, IL-8 may be a potentially useful cytokine in the setting of blood stem cell transplantation. 相似文献
58.
J D Cortese B Schwab rd C Frieden E L Elson 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(15):5773-5777
We have encapsulated actin filaments in the presence and absence of various actin-binding proteins into lipid vesicles. These vesicles are approximately the same size as animal cells and can be characterized by the same optical microscopic and mechanical techniques used to study cells. We demonstrate that the initially spherical vesicles can be forced into asymmetric, irregular shapes by polymerization of the actin that they contain. Deformation of the vesicles requires that the actin filaments be on average at least approximately 0.5 micron long as shown by the effects of gelsolin, an actin filament-nucleating protein. Filamin, a filament-crosslinking protein, caused the surfaces of the vesicles to have a smoother appearance. Heterogeneous distribution of actin filaments within the vesicles is caused by interfilament interactions and modulated by gelsolin and filamin. The vesicles provide a model system to study control of cell shape and cytoskeletal organization, membrane-cytoskeleton interactions, and cytomechanics. 相似文献
59.
Buysmann S; Bemelman FJ; Schellekens PT; van Kooyk Y; Figdor CG; ten Berge IJ 《Blood》1996,87(1):404-411
We investigated the mechanism by which antihuman CD3 monoclonal antibodies of the isotypes IgG2a (eg, OKT3) and IgA (eg, IXA) can induce the rapid disappearance of virtually all circulating T lymphocytes. We hypothesize that upregulation of adhesion molecules on the lymphocyte membrane contributes to this effect. However, this hypothesis is difficult to test, because of the inherent lymphocytopenia and/or shifts in lymphocyte populations between intra and extra-vascular compartments. Therefore, studies in vitro were performed, as well. Analysis of peripheral blood lymphocytes isolated at several times after addition of OKT3 or IXA to whole blood of healthy individuals showed an immediate increase in the proportion of T cells expressing NKI-L16, an activation epitope on CD11a/CD18. Likewise, an increase in CD11b/CD18 expression occurred. In parallel experiments, a transiently increased adhesion of T cells to endothelial cell monolayers was observed. This adhesion could be completely blocked by anti-CD18 or anti-CD11a monoclonal antibodies and only partly by an anti-CD11b antibody. Our data indicate that upregulation of activation epitopes of CD11a/CD18, as well as increased expression of CD11b/CD18 on T lymphocytes, may result in increased adhesion of these cells to intercellular adhesion molecule-1 (ICAM-1) and ICAM-2 on vascular endothelium. This phenomenon may, at least, partly explain the rapidly occurring peripheral lymphocytopenia observed in vivo. 相似文献
60.
Interleukin-8 induces rapid mobilization of hematopoietic stem cells with radioprotective capacity and long-term myelolymphoid repopulating ability 总被引:10,自引:5,他引:10
Interleukin-8 (IL-8) belongs to a family of chemoattractant cytokines involved in chemotaxis and activation of neutrophils. As in vivo administration of IL-8 induces granulocytosis and the release of immature white blood cells into the circulation, we assessed a possible mobilizing effect of IL-8 on myeloid progenitor cells. IL-8 was administered at intraperitoneal doses ranging from 0.1 to 100 micrograms per mouse to female Balb/C mice (aged 8 to 12 weeks; weight, 20 to 25 g). Animals were killed at time intervals ranging from 1 to 240 minutes after IL-8 administration, and blood, bone marrow, and spleen cells were harvested. Injection of 30 micrograms IL-8 resulted in an increment from 25 +/- 9 to 418 +/- 299 granulocyte-macrophage colony-forming units (CFU-GM) per milliliter blood at 15 minutes after a single intraperitoneal injection. Sixty minutes after the injection of IL-8, the numbers of circulating CFU-GM per milliliter blood had almost returned to pretreatment values (82 +/- 39 CFU-GM per milliliter). A dose of 100 micrograms IL-8 per animal did not result in a further increment in the number of circulating CFU-GM. Transplantation of 5 x 10(5) blood-derived mononuclear cells (MNC) obtained at 30 minutes after IL-8 injection (30 micrograms) resulted in 69% survival of lethally irradiated (8.5 Gy) recipients at 60 days versus 22% for animals transplanted with an equal number of nonprimed blood-derived MNC. Transplantation of 1.5 x 10(6) MNC obtained from IL- 8-treated donors resulted in 100% survival. Six months after transplantation, female recipients of MNC derived from IL-8-treated male donors were killed, and chimerism was determined in bone marrow, spleen, and thymus using a Y chromosome-specific probe and fluorescent in situ hybridization (FISH). The majority of bone marrow, spleen, and thymus cells (83% +/- 25%, 89% +/- 5%, and 64 +/- 28%, respectively) consisted of Y chromosome-positive cells, showing that the IL-8- mobilized cells had myelolymphoid repopulating ability. We conclude that IL-8 is a cytokine that induces rapid mobilization of progenitor cells and pluripotent stem cells that are able to rescue lethally irradiated mice and that are able to completely and permanently repopulate host hematopoietic tissues. 相似文献