全文获取类型
收费全文 | 4524篇 |
免费 | 402篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 140篇 |
妇产科学 | 77篇 |
基础医学 | 726篇 |
口腔科学 | 78篇 |
临床医学 | 546篇 |
内科学 | 948篇 |
皮肤病学 | 62篇 |
神经病学 | 267篇 |
特种医学 | 279篇 |
外科学 | 888篇 |
综合类 | 55篇 |
一般理论 | 1篇 |
预防医学 | 247篇 |
眼科学 | 201篇 |
药学 | 217篇 |
1篇 | |
中国医学 | 17篇 |
肿瘤学 | 194篇 |
出版年
2021年 | 66篇 |
2020年 | 45篇 |
2019年 | 36篇 |
2018年 | 79篇 |
2017年 | 68篇 |
2016年 | 78篇 |
2015年 | 73篇 |
2014年 | 110篇 |
2013年 | 158篇 |
2012年 | 153篇 |
2011年 | 161篇 |
2010年 | 123篇 |
2009年 | 145篇 |
2008年 | 174篇 |
2007年 | 181篇 |
2006年 | 164篇 |
2005年 | 154篇 |
2004年 | 153篇 |
2003年 | 124篇 |
2002年 | 120篇 |
2001年 | 143篇 |
2000年 | 130篇 |
1999年 | 133篇 |
1998年 | 124篇 |
1997年 | 117篇 |
1996年 | 98篇 |
1995年 | 88篇 |
1994年 | 86篇 |
1993年 | 85篇 |
1992年 | 142篇 |
1991年 | 112篇 |
1990年 | 120篇 |
1989年 | 124篇 |
1988年 | 99篇 |
1987年 | 108篇 |
1986年 | 77篇 |
1985年 | 76篇 |
1984年 | 79篇 |
1983年 | 61篇 |
1982年 | 48篇 |
1981年 | 37篇 |
1980年 | 39篇 |
1979年 | 36篇 |
1977年 | 51篇 |
1976年 | 31篇 |
1975年 | 26篇 |
1974年 | 27篇 |
1973年 | 49篇 |
1972年 | 35篇 |
1971年 | 27篇 |
排序方式: 共有4987条查询结果,搜索用时 15 毫秒
101.
Abrams P Schäfer W Tammela TL Barrett DM Hedlund H Rollema HJ Matos-Ferreira A Nordling J Bruskewitz R Andersen JT Hald T Miller P Kirby R Mustonen S Cannon A Jacobsen CA Gormley GJ Malice MP Bach MA 《The Journal of urology》1999,161(5):1513-1517
PURPOSE: We assess the effect of finasteride, a 5alpha-reductase inhibitor, on objective voiding parameters in men with lower urinary tract symptoms and benign prostatic enlargement on digital rectal examination (known as clinical benign prostatic enlargement) in a double-blind placebo controlled multicenter study using strict standard pressure flow study techniques. MATERIALS AND METHODS: A modification of the Abrams-Griffiths nomogram was used by 1 reader to ensure that all patients met objective criteria for bladder outlet obstruction at baseline. After performing a pressure flow study patients with obstruction were randomized 2:1 to receive 5 mg. finasteride (81) or placebo (40) daily. A second pressure flow study was performed at month 12. At baseline and month 12 free urinary flow studies and transrectal ultrasound were performed, and International Prostate Symptom Score questionnaires were completed. Patients were treated between May 1994 and July 1996. RESULTS: Finasteride caused a significant decrease (-8.1 cm. water) in detrusor pressure at maximum flow (p <0.05 versus placebo p = 0.02), increase (+1.1 ml. per second) in maximum flow rate (p <0.05 versus placebo p = 0.02) and decrease (-22.8%) in prostate volume (p <0.05 versus placebo p <0.001). Men with prostates larger than 40 cc had greater improvement in detrusor pressure at maximum flow (between group difference -14.5 cm. water, 95% confidence interval -26.2 to -2.6, p = 0.02) and maximum flow rate (mean treatment effect +1.6 ml. per second, 95% confidence interval -0.2 to 3.0, p = 0.02) compared to those with prostates 40 cc or less (between group differences not significant). CONCLUSIONS: Finasteride treatment resulted in improvements in urodynamic parameters, which were greater in men with large prostates. 相似文献
102.
103.
The purpose of this study was to determine the role of L3T4+, Ly2- T cells in the development of allospecific cytolytic T cells in response to purified allogeneic MHC class I+, class II- hepatocytes in vivo in hepatocyte-sponge matrix allografts (HC-SMA). In previous studies we have shown that 99% pure murine hepatocytes stimulate the development of allospecific cytolytic T cells in vitro in mixed lymphocyte-hepatocyte culture (MLHC) and in vivo in HC-SMA. Furthermore, depletion of L3T4+, Ly2- T cells from responder splenocytes inhibits the development of allo-CTLs in response to purified hepatocytes in mixed lymphocyte-hepatocyte culture. Here, using an anti-L3T4 monoclonal antibody, we tested the effect of in vivo immunodepletion of L3T4+, Ly2- T cells on the subsequent development of allo-CTLs in HC-SMA. Sponge cells were harvested on day 4 and day 12 after grafting from control and treated groups and phenotypically analyzed by FACS and immunofluorescent labelling. Splenocytes from the same animals were similarly analyzed to assess for completeness of immunodepletion. Allospecific cytotoxicity was assessed on day 12 after grafting. We found that immunotherapy with anti-L3T4 mAb was effective in depleting L3T4+, Ly2- T cells from the spleen; however, a similar number of L3T4+ cells was isolated from the sponge between control and treated groups. Furthermore, the development of allo-CTLs in response to hepatocytes in HC-SMA was completely abrogated by both local and systemic immunotherapy with anti-L3T4 mAb. We conclude from these and previous data that host or responder L3T4+, Ly2- T cells and responder accessory cells in MLHC or host macrophages in HC-SMA may participate in "indirect" recognition of hepatocyte class I antigen both in vitro and in vivo. 相似文献
104.
The hospital ethics committee serves as the topic for this third lesson of a five-part WMU/AHRA magazine course on ethics. Proliferating during the last ten years and fostered by the Karen Ann Quinlan case, hospital ethics committees today function in three areas: education, development of guidelines and policies, and individual case consultation. Using specific examples in the discussion of each function, the authors give a detailed picture of the valuable contribution these committees make to the institutions they serve. 相似文献
105.
Patterns of structural deterioration due to ischemia in Purkinje fibres and different layers of the working myocardium 总被引:1,自引:0,他引:1
P A Schnabel J Richter A Schmiedl F Bach U Bartels B Ramsauer M M Gebhard H J Bretschneider 《The Thoracic and cardiovascular surgeon》1991,39(4):174-182
Cellular and mitochondrial swelling are regarded as typical intra-ischemic alterations ("IIA"), contraction band lesions (CBL), in contrast, as products of post-ischemic reperfusion. The occurrence of both types of structural deterioration was investigated in Purkinje fibres and subendocardial and intramural working myocardium: initially after St. Thomas- or HTK cardioplegia, then during ensuing global ischemia up to the "practical limit of resuscitability", and following post-ischemic reperfusion. Generally, Purkinje fibres are not better preserved than neighbouring working myocardium. Comparing St. Thomas- and HTK cardioplegia, considerable quantitative, but not qualitative differences in the reaction patterns of different cell types or layers arise. Immediately after cardioplegia, CBL are completely lacking in both cell types. During ischemia, CBL occur occasionally in Purkinje fibres and seldom in subendocardial working myocardium, "IIA" predominate. During post-ischemic reperfusion "IIA" tend to reverse in all layers, whereas CBL are found to remain in the subendocardial cell types. In intramural layers, CBL occur only during reperfusion. Thus, we deduce that cardioplegia only modulates the severity of "IIA" and the frequency of CBL, but cannot abolish the particular sensitivity of subendocardial Purkinje fibres to global ischemia. Prerequisites for the development of irreversible CBL are on the one hand ischemic metabolic alterations and corresponding energy deficits, and, on the other hand, a supply of oxygen. The oxygen may be inadequately supplied via diffusion during ischemia or may be subsequently provided by reperfusion. 相似文献
106.
Summary After determination of the lithogenic and inhibitory substances in serum and urine of 18 healthy control subjects and 20 patients with calcium oxalate urolithiasis on an uncontrolled diet, the alteration of the parameters while taking a standard diet was investigated. After attainment of a steady state, the investigations were performed over 48h on 3-h aliquots of urine. Typical circadian rhythms were detected for all lithogenic parameters in the urine and normal ranges were established. This special investigation permits detection of peaks in the excretion of lithogenic substances which were masked in investigation of 24-h urine samples alone. 相似文献
107.
Retroperitoneal mature teratoma 15 years after initial treatment of testicular mixed germ cell tumor
Lehmann J Ritz M Nürnberg N Romahn E Bach S Küppers F Loch T Stöckle M Weichert-Jacobsen K 《European urology》2000,38(5):644-648
We present a patient with a retroperitoneal tumor noted 15 years after treatment of a testicular mixed germ cell cancer. The patient initially underwent right-sided orchiectomy and retroperitoneal lymph node dissection for clinical stage I disease. An early relapse indicated by increasing tumor markers shortly after retroperitoneal lymph node dissection was successfully treated with five cycles of combined chemotherapy. However, 187 months after completion of chemotherapy, a symptomatic right-sided iliac mass was diagnosed. Radical surgical excision of the mass was performed and histologic examination revealed differentiated mature teratoma. This represents the longest time interval reported in the literature for a mature teratoma following treatment of a testicular germ cell tumor. 相似文献
108.
BACKGROUND: Despite an increased awareness among clinicians regarding pain and pain management for infants undergoing surgery, pain associated with procedures performed outside the operating room may not be adequately managed. PURPOSE: To examine the beliefs and self-described behavior of physicians and nurses regarding the management of procedural pain in newborn infants. METHODS: A survey was distributed to 467 clinicians (nurses and physicians) working in 11 level II and 4 level III nurseries in a large metropolitan area. Respondents were asked to rate the painfulness of 12 common bedside nursery procedures and how often pharmacologic and nonpharmacologic (comfort) measures are currently used and should be used for those procedures. Demographic data were also collected. RESULTS: Surveys were completed by 374 clinicians (80% response rate). Physicians and nurses believe infants feel as much pain as adults and that 9 of the 12 listed procedures are moderately to very painful. Neither pharmacologic nor comfort measures are believed to be used frequently, even for the most painful procedures. Physicians and nurses believe both pharmacologic and comfort measures should be used more frequently, but nurses believe comfort measures should be used more frequently than do physicians. Beliefs about infant pain and procedural pain were related to pain management preferences. Physicians' but not nurses' ratings were associated with significant personal pain. CONCLUSIONS: Despite their beliefs that infants experience significant procedure-related pain, clinicians believe pain management for infants remains below optimal levels. Barriers to more consistent and effective pain management need to be identified and surmounted. 相似文献
109.
110.
An Australian study of functional status after childbirth 总被引:1,自引:0,他引:1