全文获取类型
收费全文 | 18742篇 |
免费 | 1407篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 310篇 |
儿科学 | 414篇 |
妇产科学 | 327篇 |
基础医学 | 3346篇 |
口腔科学 | 315篇 |
临床医学 | 1747篇 |
内科学 | 3699篇 |
皮肤病学 | 262篇 |
神经病学 | 1234篇 |
特种医学 | 613篇 |
外国民族医学 | 2篇 |
外科学 | 3099篇 |
综合类 | 149篇 |
一般理论 | 8篇 |
预防医学 | 1221篇 |
眼科学 | 850篇 |
药学 | 1374篇 |
中国医学 | 16篇 |
肿瘤学 | 1225篇 |
出版年
2023年 | 160篇 |
2022年 | 223篇 |
2021年 | 424篇 |
2020年 | 294篇 |
2019年 | 441篇 |
2018年 | 490篇 |
2017年 | 401篇 |
2016年 | 412篇 |
2015年 | 429篇 |
2014年 | 601篇 |
2013年 | 756篇 |
2012年 | 1055篇 |
2011年 | 958篇 |
2010年 | 577篇 |
2009年 | 545篇 |
2008年 | 871篇 |
2007年 | 879篇 |
2006年 | 802篇 |
2005年 | 765篇 |
2004年 | 718篇 |
2003年 | 652篇 |
2002年 | 638篇 |
2001年 | 482篇 |
2000年 | 482篇 |
1999年 | 434篇 |
1998年 | 213篇 |
1997年 | 150篇 |
1996年 | 176篇 |
1995年 | 142篇 |
1994年 | 158篇 |
1993年 | 126篇 |
1992年 | 308篇 |
1991年 | 310篇 |
1990年 | 336篇 |
1989年 | 343篇 |
1988年 | 316篇 |
1987年 | 271篇 |
1986年 | 285篇 |
1985年 | 291篇 |
1984年 | 209篇 |
1983年 | 192篇 |
1982年 | 101篇 |
1981年 | 100篇 |
1979年 | 139篇 |
1978年 | 96篇 |
1975年 | 86篇 |
1974年 | 118篇 |
1973年 | 108篇 |
1972年 | 83篇 |
1971年 | 77篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
1.
Clinical versus ultrasonographic evaluation of scrotal disorders 总被引:1,自引:0,他引:1
B Kromann-Andersen L B Hansen P N Larsen K Lawetz P Lynge D Lysen S P Nielsen K H Stockholm P Foged 《British journal of urology》1988,61(4):350-353
Clinical and ultrasonographic examinations of scrotal disorders were compared in 166 patients in order to determine their ability to distinguish between those diseases requiring surgery and those requiring clinical follow-up only. Ultrasound examinations were efficient in discriminating between normal and pathological findings. Extra-testicular lesions were readily differentiated from testicular ones. Although both clinical and ultrasonographic examinations had high sensitivity (90%) in detecting testicular cancer, the number of false positive findings was smaller after ultrasound examination. This gave a predictive value of a positive test of 53% after ultrasound examination but only 33% after clinical examination. Ultrasound examination may, therefore, reduce the number of surgical explorations in the scrotum and should be performed in patients with suspected testicular pathology based on history and palpatory findings. 相似文献
2.
3.
Can carotid endarterectomy be justified? No 总被引:1,自引:0,他引:1
S Jonas 《Archives of neurology》1987,44(6):652-654
4.
Michael Hermansson Anders Ekedahl Jonas Ranstam Thomas Zilling 《BMC gastroenterology》2009,9(1):25-13
Background
Despite a decreasing incidence of peptic ulcer disease, most previous studies report a stabile incidence of ulcer complications. We wanted to investigate the incidence of peptic ulcer complications in Sweden before and after the introduction of the proton pump inhibitors (PPI) in 1988 and compare these data to the sales of non-steroid anti-inflammatory drugs (NSAID) and acetylsalicylic acid (ASA). 相似文献5.
AIMS: In normotensive women with Type 1 diabetes and microalbuminuria we previously found preterm delivery (< 34 weeks) in 23% of the pregnancies. Antihypertensive treatment was initiated in late pregnancy when preeclampsia was diagnosed and diastolic blood pressure > 90 mmHg. From April 2000 our routine was changed and early antihypertensive treatment with methyldopa was initiated if antihypertensive treatment was given prior to pregnancy, if urinary albumin excretion (UAE) was > 2 g/24 h, or blood pressure > 140/90 mmHg. The present study describes the impact of this more aggressive antiypertensive treatment in the prevalence of preterm delivery. METHODS: The old cohort (1995-1999) consisted of 26 and the new cohort (2000-2003) of 20 pregnant women with Type 1 diabetes and microalbuminuria. All were referred before gestational week 17. RESULTS: The cohorts were comparable with regard to age, diabetes duration, prepregnancy body mass index, HbA1c, blood pressure 121 (13)/71 (8) vs. 121 (14)/73 (8) mmHg [mean (sd)] and early UAE 69 (16-278) vs. 74 (30-287) mg/24 h (geometric mean and range). Antihypertensive treatment was initiated in the old cohort at 29 (20-33) weeks, n = 9, and in the new at 13 (0-34) weeks, n = 10. The prevalence of preterm delivery before 34 weeks was reduced from 23% to zero (P = 0.02), preterm delivery before 37 weeks from 62% to 40% (P = 0.15) and preeclampsia from 42% to 20% (P = 0.11). Perinatal mortality occurred in 4% vs. 0%. Birth weight was 3124 (767) g vs. 3279 (663) g. CONCLUSION: Introduction of early antihypertensive treatment with methyldopa in normotensive pregnant women with Type 1 diabetes and microalbuminuria resulted in a significant reduction in preterm delivery before gestational week 34. 相似文献
6.
Jenny Andersson Barbro Linderholm Jonas Bergh Goran Elmberger 《Applied immunohistochemistry & molecular morphology》2004,12(1):14-20
We have studied the intratumor HER-2/neu heterogeneity in 78 consecutive and population-based primary invasive breast carcinomas. Within the invasive component, heterogeneity was detected in only 1 of 78 tumors. In 48 tumors (62%), we found both in situ and invasive components in analyzed tissue sections. Twelve of these 48 tumors had a difference of at least 2 arbitrary units in the in situ compared with the invasive part of the tumor with regard to the HER-2/neu status analyzed by HercepTest (immunohistochemistry). Eight of these 12 tumors were reanalyzed with fluorescent in situ hybridization and immunohistochemistry with and without a new Automated Cellular Imaging System. In this limited material, immunohistochemistry in combination with the Automated Cellular Imaging System seemed to have a better correlation with fluorescent in situ hybridization than immunostaining analyzed manually. In conclusion, HER-2/neu expression is not seldom heterogeneous in invasive compared with in situ components within a tumor. This finding should be considered in the choice of evaluation method. To avoid heterogeneity as a confounding factor in HER-2/neu analyses, detection methods such as immunohistochemistry and fluorescent in situ hybridization, which can provide evaluation in a preserved tissue architecture, should be used. Perhaps the intratumor HER-2/neu heterogeneity can explain some of the unexpected failures of trastuzumab therapy. 相似文献
7.
From 1974 to 1983, simple and radical nephrectomies were performed at the Chaim Sheba Medical Center (Tel Hashomer, Israel) for renal cell carcinoma. The authors reviewed 109 cases that were followed for a period ranging from 5 to 14 years. Simple nephrectomy was performed in 55 patients, and 54 patients underwent radical nephrectomy. The selection of the surgical procedure was based on the surgeon's preference and not on the basis of clinical stage, age, or sex. The surgical results and survival rates were assessed according to the pathologic stage of the tumors. Among patients with Stage I tumor, radical nephrectomy produced better survival rates at 5 and 10 years (P = 0.03); however, when the non-cancer deaths were excluded, the difference in survival was not statistically significant. For Stage I tumors the survival free of disease at 5 years was better for the radical nephrectomy group, but this difference was not statistically significant. No difference was noticed in the local recurrence rate between the two groups. Nephrectomy in patients with Stage IV disease did not alter survival regardless of the type of operation. 相似文献
8.
We conducted a clinical and pathologic review of 14 patients with immature ovarian teratoma. In this series of patients, one had monodermal malignant neuroectodermal teratoma and two others had immature ovarian teratoma in association with immature presacral teratoma. Because of the small number of cases of immature ovarian teratoma and the diverse therapeutic modalities used in this study, we cannot recommend a specific treatment for patients with this tumor on the basis of our findings. The histologic grade of the tumor seemed to be a reliable indicator of prognosis. Grade 0 metastatic lesions should be considered benign and are associated with a favorable prognosis. 相似文献
9.
10.
Five ileal conduit biopsies, taken after 1-7 years, were examined by light microscopy and scanning electron microscopy. The total height of the lamina mucosa decreased from 700 to 275 microns. The height of the villi diminished from 550 to 50 microns; the depth of the crypts increased from 130 to 244 microns and the villus-crypt index changed from 4.2 to 0.2. Signs of chronic inflammation could be observed. Scanning electron microscopy shows that the number of microvilli per cell was markedly reduced. There was a varied picture of different stages of atrophy. After 3 years microvilli could no longer be observed. In view of the prolonged urinary contamination time, it appears to be imperative to check neobladders with regard to possible carcinoma induction. 相似文献