首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   898篇
  免费   90篇
  国内免费   14篇
耳鼻咽喉   3篇
儿科学   27篇
妇产科学   31篇
基础医学   77篇
口腔科学   5篇
临床医学   64篇
内科学   182篇
皮肤病学   35篇
神经病学   52篇
特种医学   169篇
外科学   145篇
综合类   23篇
预防医学   93篇
眼科学   50篇
药学   19篇
中国医学   1篇
肿瘤学   26篇
  2021年   10篇
  2019年   14篇
  2018年   17篇
  2017年   14篇
  2016年   19篇
  2015年   9篇
  2014年   18篇
  2013年   21篇
  2012年   36篇
  2011年   29篇
  2010年   21篇
  2009年   29篇
  2008年   25篇
  2007年   39篇
  2006年   24篇
  2005年   20篇
  2004年   22篇
  2003年   14篇
  2002年   13篇
  2001年   14篇
  2000年   12篇
  1999年   14篇
  1998年   19篇
  1997年   29篇
  1996年   28篇
  1995年   20篇
  1994年   17篇
  1993年   17篇
  1992年   14篇
  1991年   11篇
  1989年   26篇
  1988年   25篇
  1987年   25篇
  1986年   24篇
  1985年   24篇
  1984年   19篇
  1983年   12篇
  1979年   14篇
  1978年   13篇
  1977年   8篇
  1976年   12篇
  1975年   13篇
  1974年   8篇
  1973年   16篇
  1972年   11篇
  1971年   11篇
  1970年   8篇
  1969年   8篇
  1967年   8篇
  1966年   11篇
排序方式: 共有1002条查询结果,搜索用时 0 毫秒
51.
VITALLIUM TUBES IN BILIARY SURGERY   总被引:1,自引:0,他引:1  
Pearse HE 《Annals of surgery》1942,115(6):1031-1042
  相似文献   
52.
Dershaw  DD; Shank  B; Reisinger  S 《Radiology》1987,164(2):455-461
Following local excision and definitive irradiation of 163 breast cancers in 160 women, alterations in mammographic patterns were observed for up to 7 years. Skin thickening was observed in 96% of mammograms obtained within 1 year of completing therapy and was most pronounced in women treated with iridium implant, chemotherapy, or axillary dissection. In 76% of mammograms, alterations in the parenchymal pattern, including coarsening of stroma and increased breast density, were seen at 1 year. Neither skin nor parenchymal changes progressed after 1 year. Within 3 years of treatment the parenchymal density, which usually regressed, did not change in all patients. At 3 years skin thickness and the parenchymal pattern had returned to normal in less than 50% of the breasts of these women. Scars developed in approximately one-quarter of women. They were present on the initial post-treatment mammogram and remained unchanged on serial studies. Coarse, benign calcifications also developed in the breasts of about one-quarter of women. Microcalcifications developed in 11 breasts; biopsy specimens of six were benign. Benign microcalcifications may be related to therapy.  相似文献   
53.
Lymphangiomas in children: MR imaging   总被引:9,自引:0,他引:9  
Seventeen lymphangiomas in 15 patients were imaged with magnetic resonance (MR) to define the nature, extent, and anatomic relationships of these lesions. The MR and pathologic findings were then compared to determine the histologic basis for the signal-intensity characteristics of these lesions. The signal intensity of 13 lesions was similar to or slightly less than that of muscle on T1-weighted images and greater than that of fat on T2-weighted images. This appearance correlated with the presence of ectatic lymphatic channels containing clear fluid on histologic section. Four lymphangiomas had high signal intensity, approximately equal to that of fat, on T1-weighted images, reflecting the presence of clotted blood or small cystic spaces with a higher ratio of fat to fluid. Sixteen of 17 lesions had visible septations on MR images. The authors' experience suggests that most lymphangiomas have a characteristic appearance on MR images. The information obtained with MR imaging can help in providing a preoperative diagnosis, in planning surgical resection, and in defining recurrence.  相似文献   
54.
Acute placement of a suprapubic bladder tube followed months later by open urethroplasty has been the traditional manner for managing traumatic disruption of the proximal urethra. The latter procedure has generally been performed via the transpubic or perineal approach. These procedures have been complicated by excessive blood loss, impotence, incontinence, strictures, and extended hospitalizations. Since 1979, 12 patients with obliterated urethras (ten membranous, two bulbous) have been treated by direct vision urethrotomy using a second cystoscope or sound passed through the previously placed suprapubic tract as a guide. Mean blood loss, hospital stay, and followup were 70 ml, 6 days, and 22 months, respectively. Six patients required at least one additional internal urethrotomy. With the exception of one patient who still requires intermittent self-catheterization, all have stable strictures. Ten are continent (one was incontinent secondary to previous radical prostatectomy before urethrotomy and one became incontinent after a TURP performed 3 years after urethrotomy). Five are potent and none lost potency as a result of urethrotomy. Flow rates range from 15-25 ml/second in the continent patients. This is a reasonable first procedure for restoring continuity of traumatically obliterated membranous and bulbous urethras.  相似文献   
55.
Liver metastases: detection by phase-contrast MR imaging   总被引:1,自引:0,他引:1  
Stark  DD; Wittenberg  J; Middleton  MS; Ferrucci  JT  Jr 《Radiology》1986,158(2):327-332
Forty patients with biopsy-proved metastatic liver cancers were studied by magnetic resonance (MR) imaging using one or more conventional (in-phase) pulse sequences and a corresponding phase-contrast (opposed-phase) pulse sequence. Pulse-sequence performance was quantitated by measuring signal-difference-to-noise (SD/N) ratios between cancerous tissue and liver. The SD/N performance of T2-weighted spin-echo (SE) pulse sequences improved when used with the phase-contrast technique. SE 2,000/30 opposed-phase images showed improved (P less than .001) SD/N in 72% of patients over in-phase images. The SD/N of T1-weighted SE or inversion recovery pulse sequences deteriorated when used with the phase-contrast technique. Changes in measured SD/N correlated well with image appearance and actual lesion detectability in individual cases. Phase-contrast imaging should be employed routinely when T2-weighted SE pulse sequences are relied on to detect liver cancer.  相似文献   
56.
Between December 1986 and October 1988, 83 patients with chronic peripheral artery occlusions were treated with a new technique. In 56 patients, the superficial femoral artery was completely occluded; in 21 patients, the popliteal artery; and in six patients, the iliac artery. The length of occlusion ranged from 5 to 35 cm (mean, 12.5 cm). The duration, estimated by history, was 5-48 months (mean, 16.5 months). In seven patients, durations of 6-36 months were documented angiographically. A flexible, blunt, motor-driven rotating catheter was introduced through an 8-F sheath, and rotational angioplasty was performed at low speed (up to 200 rpm). In 49 of 60 (82%) patients in whom this new technique was used as the primary intervention, the occlusions were successfully reopened. In 23 patients in whom conventional methods had failed more than 4 weeks earlier, the success rate for rotational angioplasty was 67% (12 of 18 patients); when the time interval was less than 4 weeks, only one of five patients was treated successfully. In none of the 83 patients did a perforation occur. This new technique can reopen chronic artery occlusions with a high degree of success and without the danger of vessel-wall perforation, even after failure of conventional techniques.  相似文献   
57.
58.
59.
60.
The way in which medical professionals engage in bioethical issues ultimately reflects the type of care such patients are likely to receive. It is therefore critical for doctors and other health care professionals to have a broad understanding of disability. Our purpose in this paper is to explore ways of teaching bioethical issues to first year medical students by integrating alternative approaches. Such approaches include (a) the use of the narrative format, (b) the inclusion of a disability perspective, and (c) the presentation and facilitation of classes by people with disabilities. We consider how these new kinds of presentations are evaluated by students, faculty, people with disabilities and professional ethicists. We hope new knowledge may provide health care professionals with a greater understanding of the perspectives of patients with disabilities, who are confronted by conflicting ethical values and frameworks for decision-making in their interaction with such professionals.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号