全文获取类型
收费全文 | 741篇 |
免费 | 35篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 19篇 |
妇产科学 | 12篇 |
基础医学 | 46篇 |
口腔科学 | 17篇 |
临床医学 | 56篇 |
内科学 | 124篇 |
皮肤病学 | 18篇 |
神经病学 | 3篇 |
特种医学 | 137篇 |
外国民族医学 | 1篇 |
外科学 | 238篇 |
综合类 | 10篇 |
预防医学 | 21篇 |
眼科学 | 3篇 |
药学 | 15篇 |
肿瘤学 | 68篇 |
出版年
2023年 | 1篇 |
2022年 | 8篇 |
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 16篇 |
2014年 | 10篇 |
2013年 | 39篇 |
2012年 | 19篇 |
2011年 | 19篇 |
2010年 | 30篇 |
2009年 | 39篇 |
2008年 | 18篇 |
2007年 | 35篇 |
2006年 | 24篇 |
2005年 | 20篇 |
2004年 | 24篇 |
2003年 | 30篇 |
2002年 | 26篇 |
2001年 | 32篇 |
2000年 | 16篇 |
1999年 | 15篇 |
1998年 | 51篇 |
1997年 | 47篇 |
1996年 | 23篇 |
1995年 | 25篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 5篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 7篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有789条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
2.
Demonstration of specific antibodies against diethylstilbestrol during treatment of prostatic cancer
Antibodies against diethylstilboestrol were detected in prostatic cancer patients treated with diethylstilboestrol (DES). Direct radioimmunoassay (DRIA) was performed in 109 patients divided into three groups: a control group of 33 patients (group I), a group of 38 patients treated by DES and free of cardiovascular complications (group II), and a group of 38 patients treated by DES with cardiovascular complications (group III). Antibody count was significantly higher in group III than in the two other groups (p less than 0.05). These results suggest that DES antibodies may play a role in estrogen-associated cardiovascular toxicity. For this reason, DES should not be used in patients with a positive assay. 相似文献
3.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
4.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
5.
6.
7.
Daher A de Boer WI El-Marjou A van der Kwast T Abbou CC Thiery JP Radvanyi F Chopin DK 《Laboratory investigation; a journal of technical methods and pathology》2003,83(9):1333-1341
Members of the epidermal growth factor (EGF) family and their receptors are involved in many cellular processes, including proliferation, migration, and differentiation. We have previously reported that these growth factors are expressed and have specific regulatory functions in an organ-like culture model of normal human urothelial cells. Here, we used this model to investigate the involvement of EGF receptor (EGFR) in human urothelial regeneration. Three 4-mm-diameter damaged areas were made in confluent normal human urothelial cell cultures with a biopsy punch. Regeneration was measured, on fixed stained cultures, with an image analyzer, at 4, 24, and 48 hours after injury. Cell proliferation was assessed by 5-bromo-2-deoxyuridine incorporation. To identify EGF family factors potentially involved in the healing process, we studied the effect of these factors on damaged confluent cultures and the level of expression of mRNAs extracted from these cultures. EGFR inhibition of the proliferation and migration of urothelial cells was tested with (1). a specific tyrosine kinase inhibitor (AG1478) and (2). a blocking anti-EGFR antibody (LA22). Exogenously added amphiregulin, EGF, transforming growth factor-alpha and heparin-binding EGF (HB-EGF) stimulated urothelial regeneration. The damaged areas were repaired by regrowth within 48 hours. Both AG1478 and LA22 inhibited the repair (by 50% and 30%, respectively), as well as proliferation and migration. This regeneration was accompanied by increased HB-EGF mRNA expression in cultures of cells from four of six subjects, but no corresponding change in EGFR protein level was observed. These results indicate that the EGFR signaling pathway is involved in urothelial regeneration. Our data support an autocrine role of HB-EGF in this process and suggest that the EGFR pathway is a potential therapeutic target for modulating urothelial cell proliferation. 相似文献
8.
9.
10.
Bilateral simultaneous tubal sextuplets: pregnancy after in-vitro fertilization--embryo transfer following salpingectomy 总被引:2,自引:1,他引:2
The presence of a damaged tube has been suggested in recent studies to have
a negative effect on in-vitro fertilization (IVF) outcome. Performing
bilateral salpingectomy prior to IVF to maximize pregnancy rates may also
result in unnecessary surgery. This case is also an example of the
occurrence of interstitial pregnancy after salpingectomy. This unusual type
of ectopic pregnancy must be kept in mind when evaluating a patient
suspected of a possible early abnormal gestation after assisted
reproductive technolologies.
相似文献