全文获取类型
收费全文 | 923篇 |
免费 | 62篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 52篇 |
妇产科学 | 110篇 |
基础医学 | 91篇 |
口腔科学 | 25篇 |
临床医学 | 69篇 |
内科学 | 136篇 |
皮肤病学 | 8篇 |
神经病学 | 19篇 |
特种医学 | 77篇 |
外科学 | 134篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 29篇 |
眼科学 | 99篇 |
药学 | 50篇 |
肿瘤学 | 70篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 23篇 |
2020年 | 8篇 |
2019年 | 19篇 |
2018年 | 13篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 31篇 |
2014年 | 35篇 |
2013年 | 32篇 |
2012年 | 34篇 |
2011年 | 37篇 |
2010年 | 30篇 |
2009年 | 35篇 |
2008年 | 31篇 |
2007年 | 23篇 |
2006年 | 23篇 |
2005年 | 25篇 |
2004年 | 14篇 |
2003年 | 23篇 |
2002年 | 15篇 |
2001年 | 31篇 |
2000年 | 15篇 |
1999年 | 15篇 |
1998年 | 25篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 17篇 |
1994年 | 27篇 |
1993年 | 16篇 |
1992年 | 30篇 |
1991年 | 25篇 |
1990年 | 15篇 |
1989年 | 32篇 |
1988年 | 28篇 |
1987年 | 18篇 |
1986年 | 28篇 |
1985年 | 22篇 |
1984年 | 20篇 |
1983年 | 16篇 |
1982年 | 7篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1976年 | 8篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1967年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有987条查询结果,搜索用时 31 毫秒
101.
A prospective randomized study at a single renal transplant center between 1980 and 1982 compared the influence of leukocyte-depleted versus packed red cell pretransplantation blood transfusions on patient sensitization to leukocyte (HLA) antigens, likelihood of receiving a graft, and eventual transplantation results. All consenting potential cadaver renal transplant recipients (n = 107) were randomly assigned to receive transfusions at 6-week intervals with either packed red cells (Group 1) or leukocyte-poor red cells (Group 2) until they were transplanted. Actuarial graft and patient survival were identical for graft recipients in both groups. Although the likelihood of receiving a graft was associated with the level of pretransplant sensitization to leukocyte (HLA) antigens (p less than 0.02) as measured by the percent of panel reactive antibody (PRA), it was not associated with the type of blood used. The highest mean peak reactive PRA level for all patients showed a low but significant increase (29 +/- 4 versus 43 +/- 5%; p less than 0.0005) following entry into the transfusion protocol, but the rate of increase was the same for patients in both treatment groups. The likelihood of receiving a transplant was primarily associated with a history of prior graft rejection (p less than 0.05), and patients with prior graft loss had the greatest increase in sensitization following entry into the transfusion protocol. These findings indicate that using leukocyte-poor red cells for pretransplant transfusions provided no added benefit when compared with packed red cells in terms of patient sensitization, the likelihood of receiving a transplant, or eventual graft survival. 相似文献
102.
Christine L. Cook Julia A. Schroeder Marvin A. Yussman Joseph S. Sanfilippo 《American journal of obstetrics and gynecology》1984,149(6):613-616
The effect of clomiphene citrate and progesterone on luteal function in infertile women was studied. Endometrial biopsies were performed in 103 women immediately prior to menstruation. Group 1 (n = 62) had secretory endometrium with a histologic lag time of ≥48 hours with respect to the subsequent menses, that is, luteal phase defect. Group 2 (n = 10) had normal histologic characteristics of the secretory phase. Group 3 (n = 31) had anovulatory endometrium. The last group was subdivided into those with polycystic ovary syndrome (n = 9) and those without the characteristic gonadotropin pattern of polycystic ovary syndrome (n = 22). Clomiphene citrate at doses of 50 to 250 mg daily for 5 days was administered for induction of ovulation, timing of ovulation, or treatment of luteal phase defect. An endometrial biopsy was obtained after three ovulatory treatment cycles. Only one fourth of the women with prior luteal phase defect had normalization of the biopsy specimen with clomiphene citrate, while one half of those treated with progesterone had normal specimens. Half of the normally ovulating women had induction of a luteal phase defect with clomiphene citrate. Only women with polycystic ovary syndrome had consistently well-timed endometrial histologic features with clomiphene citrate therapy. Despite successful induction of ovulation, 16 of the other 22 previously anovulatory women had endometrial histologic findings compatible with luteal phase defect. Increasing the clomiphene citrate dosage was unsuccessful in improving endometrial maturation. These results suggest that the use of clomiphene citrate may be associated with a high rate of luteal phase defect induction, except among women with polycystic ovary syndrome. Clomiphene citrate, even at high doses, appears to be ineffective therapy for luteal phase defect. 相似文献
103.
104.
The use of computed tomography in recurrent rectal tumors 总被引:5,自引:1,他引:4
105.
Duplex Doppler sonography of renal transplants: lack of sensitivity and specificity in establishing pathologic diagnosis 总被引:1,自引:0,他引:1
Recent reports have suggested the value of duplex Doppler sonography in the assessment of renal transplant function. Accurate diagnosis of acute rejection and its distinction from acute tubular necrosis and cyclosporine A toxicity have been claimed. We undertook a combined retrospective and prospective analysis of duplex Doppler examinations performed over a 2-year period to assess the value of such studies in evaluating renal allograft dysfunction. Seventy-seven sonographic examinations were performed on 77 renal transplants. A mean resistive index was calculated from Doppler measurements within main, segmental, and interlobar renal arteries by using the following ratio. peak systolic blood-flow velocity--minimum end-diastolic blood-flow velocity/peak systolic blood-flow velocity Forty-eight Doppler results were correlated with transplant biopsies and 29 with clinical course. Twenty-three episodes of acute allograft rejection were confirmed. When a resistive index of greater than or equal to 0.9 was used to indicate acute rejection, sonography had a sensitivity of only 9% and a specificity of 91% for this diagnosis. In one of eight cases of cyclosporine A toxicity and in three of six examples of acute tubular necrosis, the resistive index was greater than 0.9. In all six instances of chronic rejection, the resistive index was less than 0.84. None of eight patients with evidence of infection had a resistive index greater than 0.9. The resistive index range of 12 normally functioning allografts was 0.57-0.69. Correlation between the resistive index and the severity of arterial and arteriolar changes on biopsy was poor. An increased resistive index of renal transplant blood flow, as measured by duplex Doppler sonography, usually signals pathologic changes in an allograft. However, our data indicate that this test is not as sensitive or specific in identifying the cause of transplant dysfunction as has been suggested previously. 相似文献
106.
107.
Ultrasound diagnosis of adrenal hemorrhage in meningococcemia 总被引:2,自引:0,他引:2
Two cases of adrenal hemorrhage in meningococcemia detected by ultrasound are reported. Antemortem detection of adrenal pathology
may have important prognostic and therapeutic implications. The sonographic appearance may be echofree, mixed, or echogenic.
Abdominal ultrasound examination can be an effective non-invasive tool in diagnosing adrenal hemorrhage. 相似文献
108.
Work in progress: [18F] fluorodeoxyglucose and positron emission tomography in the evaluation of radiation necrosis of the brain 总被引:3,自引:0,他引:3
109.
110.