全文获取类型
收费全文 | 19097篇 |
免费 | 1781篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 239篇 |
儿科学 | 597篇 |
妇产科学 | 399篇 |
基础医学 | 2321篇 |
口腔科学 | 369篇 |
临床医学 | 2547篇 |
内科学 | 3713篇 |
皮肤病学 | 254篇 |
神经病学 | 1406篇 |
特种医学 | 1011篇 |
外国民族医学 | 3篇 |
外科学 | 2443篇 |
综合类 | 490篇 |
一般理论 | 9篇 |
预防医学 | 2014篇 |
眼科学 | 600篇 |
药学 | 1541篇 |
中国医学 | 15篇 |
肿瘤学 | 984篇 |
出版年
2021年 | 321篇 |
2020年 | 214篇 |
2019年 | 297篇 |
2018年 | 338篇 |
2017年 | 206篇 |
2016年 | 288篇 |
2015年 | 310篇 |
2014年 | 413篇 |
2013年 | 610篇 |
2012年 | 816篇 |
2011年 | 874篇 |
2010年 | 506篇 |
2009年 | 453篇 |
2008年 | 745篇 |
2007年 | 871篇 |
2006年 | 860篇 |
2005年 | 789篇 |
2004年 | 771篇 |
2003年 | 699篇 |
2002年 | 658篇 |
2001年 | 581篇 |
2000年 | 612篇 |
1999年 | 544篇 |
1998年 | 281篇 |
1997年 | 268篇 |
1996年 | 287篇 |
1995年 | 246篇 |
1994年 | 219篇 |
1993年 | 200篇 |
1992年 | 424篇 |
1991年 | 428篇 |
1990年 | 401篇 |
1989年 | 434篇 |
1988年 | 379篇 |
1987年 | 362篇 |
1986年 | 373篇 |
1985年 | 354篇 |
1984年 | 270篇 |
1983年 | 237篇 |
1982年 | 163篇 |
1981年 | 127篇 |
1979年 | 201篇 |
1978年 | 179篇 |
1977年 | 150篇 |
1976年 | 141篇 |
1975年 | 121篇 |
1974年 | 162篇 |
1973年 | 146篇 |
1972年 | 129篇 |
1971年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
J F Cockburn C A Eynon N Virji J E Jackson 《AJR. American journal of roentgenology》1992,159(1):121-124
During a 9-month period, 69 Hickman catheters were successfully inserted by using angiographic techniques in 59 patients with hematologic disorders. A pneumothorax, which did not require drainage, developed in one patient. No other significant complications occurred at the time of insertion. Eighteen catheters were removed electively, 15 are still in situ, six were removed for thrombosis, and five were accidentally removed. Infection precipitated removal in six subjects. Ten patients died with the catheter in place. Five catheters were removed in patients with refractory septicemia of unknown origin. One catheter burst during an injection and had to be removed. Three patients were lost to follow-up. There were 3.24 infectious episodes per 1000 days of catheterization, more than twice the rate found in some other series. The results of this study are compatible with the growing body of evidence in favor of the angiographic insertion of Hickman catheters. The apparently high rate of infection is ascribed to factors other than insertion in the angiography suite, including the high proportion of bone marrow transplantation patients. 相似文献
42.
Annette Jackson Cynthia McSherry Kim Butters Michael Diko P.Stephen Almond Arthur J Matas Nancy L Reinsmoen 《Human immunology》1997,55(2):148-153
Our previous studies have shown that the in vitro assay of donor antigen-specific hyporeactivity is a useful marker for identifying solid organ transplant recipients (kidney, lung and heart) at low risk for immunologic complications (i.e., late acute rejection episodes and chronic rejection). Donor antigen-specific hyporeactivity is defined as a significantly decreased post- vs. pretransplant proliferative response to donor antigens while response to third-party controls remains unchanged. We analyzed whether exposure to the same HLA-DR antigen pretransplant via random blood transfusion and posttransplant via the transplanted organ influenced the development of hyporeactivity. Thirty previously nontransfused recipients, each receiving two 150 ml pretransplant random blood transfusions, were assessed for hyporeactivity at 1 year posttransplant. Of the 12 recipients with pretransplant exposure to kidney HLA-DR via transfusions, 6 (50%) developed hyporesponsiveness; in contrast, of the 18 recipients who were not preexposed, only 3 (15%) exhibited this form of immunomodulation. Of interest, 2 of the 3 hyporesponsive recipients who were not preexposed, received units containing HLA-DR antigens previously shown to share crossreactive epitopes with the kidney HLA-DR. In conclusion, these results suggest a increased incidence in the development of hyporeactivity in patients receiving pretransplant transfusions which share an HLA-DR antigen with the transplanted kidney. 相似文献
43.
Addiction was written by David Marteau, a nurse and former headof treatment at Clouds House. It is a short book offering comprehensivecoverage of the causes, nature and treatment of 相似文献
44.
45.
46.
B E Barton R Mayer J V Jackson M A Clark 《Immunopharmacology and immunotoxicology》1991,13(1-2):199-218
NFS60, a murine leukemia cell line, responds to both interleukin 3 and 6 by proliferating, apparently by different signal transduction pathways. Although stimulation by both cytokines increases the uptake of 3H-arachidonic acid, the response to IL-6 was much faster. Furthermore, the effect of various arachidonic acid metabolites on the response to cytokine was different. PGE2 inhibited IL-6-induced proliferation and potentiated the response to IL-3. Additionally the G proteins which coupled the IL-3 and IL-6 receptor to the proliferative response are probably different, based on the ability of cholera toxin to inhibit the IL-3 but not the IL-6 response. These data are evidence of two pathways of signal transduction. 相似文献
47.
Bisphosphonate treatment of Paget's disease results in a large decrease in urinary peptide-bound pyridinolines but a smaller decrease in urinary free pyridinolines. This discrepancy could be explained by changes in renal handling of pyridinoline forms. We studied eight patients with Paget's disease treated with pamidronate. We collected blood and urine at baseline and at 3 and 14 days after treatment. We measured free and total deoxypyridinoline (DPD) in serum (S) and urine (U) by high-performance liquid chromatography (HPLC). The ratio of free to total DPD at baseline was (mean +/- SE) 13 +/- 1% in serum and 37 +/- 3% in urine; at 3 days, this had increased to 25 +/- 3% in serum and 62 +/- 7% in urine. Peptide-bound (pb) DPD decreased significantly 3 days after treatment: UpbDPD -63 +/- 11%, p < 0.001; SpbDPD -51 +/- 8%, p < 0.01. Free DPD decreased in the urine after 14 days: UfDPD -48 +/- 5%, p < 0.01; there was no significant change in SfDPD. The fractional excretion of pbDPD relative to creatinine was less than one at all time-points; however, the fractional excretion of fDPD was significantly greater than one throughout the study. As a consequence, the proportion of free DPD in the urine increased as bone turnover decreased. This resulted in a smaller decrease in urine free compared with peptide-bound DPD in response to bisphosphonate therapy. Thus, the conversion of peptide-bound to free DPD in the kidney may become more efficient as bone turnover decreases as a consequence of pamidronate treatment. 相似文献
48.
49.
Revision chronic ear surgery. 总被引:6,自引:0,他引:6
David M Kaylie Edward K Gardner C Gary Jackson 《Otolaryngology--head and neck surgery》2006,134(3):443-450
OBJECTIVE: To report results of revision chronic ear surgery following guidelines of the American Academy of Otolaryngology-Head and Neck Surgery and to establish expectations for infection and cholesteatoma control and hearing outcomes. STUDY DESIGN: Retrospective case review of all patients who underwent revision chronic ear surgery from January 1, 1990 to December 31, 2000. Revision chronic ear surgery included canal wall up and canal wall down procedures with ossicular chain reconstruction performed as needed. Cholesteatoma control, hearing improvement, and closure of middle ear space are main outcome measures. SETTING: Tertiary referral center. RESULTS: Cholesteatoma recurrence rate was 57% at 1 year after surgery and 14% in patients with a minimum of a 5-year follow-up. Disease control was achieved in 96% of patients. Hearing was significantly improved in all surgical groups. Closure of the air-bone gap for revision partial ossicular replacement prosthesis cases (PORP) to less than 20 dB occurred in 50% of patients. Closure of the air-bone gap to within 30 dB for revision total ossicular replacement prosthesis (TORP) occurred in 60% of patients. Canal wall down status had a significant impact on hearing results after PORPs and TORPs; patients with intact canal walls had significantly better hearing results. Diagnosis of cholesteatoma significantly impacted hearing results for TORPs but not PORPS. CONCLUSIONS: Cholesteatoma control rates after revision surgery are similar to primary cases. Significant improvement in hearing can be expected after revision chronic ear surgery. Hearing results after a revision surgery that requires a PORP is worse than primary cases and is canal wall status dependent. Closure of the middle ear space and creation of a safe dry ear can be expected after revision chronic ear surgery. SIGNIFICANCE: This is a review of a large series of exclusively revision chronic ear surgery. EBM rating: C-4. 相似文献
50.
Percutaneous bone marrow grafting of fractures and bony defects. An experimental study in rabbits 总被引:6,自引:0,他引:6
D Paley M C Young A M Wiley V L Fornasier R W Jackson 《Clinical orthopaedics and related research》1986,(208):300-312
Since bone marrow has been shown to contain osteoprogenitor cells, an experiment was devised to test its effects when injected percutaneously into osteotomies and 2-cm bony defects produced in rabbit radii. The parameters tested included callus volume, breaking load, tensile strength, and cross-sectional area of callus at the fracture or bony defect site. At two weeks postgrafting callus volume was significantly higher (p less than 0.01) in the grafted radii than in the contralateral saline controls. By four weeks all four parameters were significantly greater in the bone marrow grafted radii than in the contralateral saline controls. Serial radiographs and histology confirm this advanced fracture healing in the grafted bones. The earlier and more abundant callus, at the bone marrow grafted sites, was felt to provide earlier and greater stability, resulting in decreased early healing time when contrasted with the saline controls. Similarly, the bony defects that were grafted with bone marrow united by a bony bridge, whereas the saline controls did not. Percutaneous bone marrow grafting is a simple semi-invasive technique that may have potential clinical applications. 相似文献