全文获取类型
收费全文 | 1438篇 |
免费 | 56篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 79篇 |
妇产科学 | 16篇 |
基础医学 | 159篇 |
口腔科学 | 45篇 |
临床医学 | 146篇 |
内科学 | 350篇 |
皮肤病学 | 29篇 |
神经病学 | 121篇 |
特种医学 | 255篇 |
外科学 | 71篇 |
综合类 | 16篇 |
一般理论 | 1篇 |
预防医学 | 86篇 |
眼科学 | 7篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 62篇 |
出版年
2023年 | 6篇 |
2021年 | 9篇 |
2019年 | 5篇 |
2018年 | 20篇 |
2017年 | 12篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 21篇 |
2013年 | 26篇 |
2012年 | 36篇 |
2011年 | 32篇 |
2010年 | 42篇 |
2009年 | 53篇 |
2008年 | 47篇 |
2007年 | 44篇 |
2006年 | 42篇 |
2005年 | 45篇 |
2004年 | 38篇 |
2003年 | 43篇 |
2002年 | 40篇 |
2001年 | 25篇 |
2000年 | 19篇 |
1999年 | 23篇 |
1998年 | 51篇 |
1997年 | 71篇 |
1996年 | 55篇 |
1995年 | 45篇 |
1994年 | 53篇 |
1993年 | 55篇 |
1992年 | 20篇 |
1991年 | 19篇 |
1990年 | 24篇 |
1989年 | 50篇 |
1988年 | 52篇 |
1987年 | 32篇 |
1986年 | 38篇 |
1985年 | 38篇 |
1984年 | 22篇 |
1983年 | 22篇 |
1982年 | 20篇 |
1981年 | 21篇 |
1980年 | 28篇 |
1979年 | 8篇 |
1978年 | 13篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 24篇 |
1974年 | 8篇 |
1973年 | 6篇 |
1969年 | 4篇 |
排序方式: 共有1497条查询结果,搜索用时 15 毫秒
61.
Marrow harvesting from normal donors 总被引:4,自引:2,他引:4
Buckner CD; Clift RA; Sanders JE; Stewart P; Bensinger WI; Doney KC; Sullivan KM; Witherspoon RP; Deeg HJ; Appelbaum FR 《Blood》1984,64(3):630-634
The experience at a single institution in harvesting marrow for allogeneic transplantation on 1,270 occasions from 1,160 normal donors is presented in detail, together with an analysis of all the donor complications. Four donors were less than 2 years old, and the youngest was 6 1/2 months. No special difficulties were encountered with these young donors. Hospitalization time was three days or less for 99% of the procedures. Six donors had life-threatening complications; three of a cardiopulmonary and two of an infectious nature, and one cerebrovascular embolic episode. Significant operative site morbidity, usually transient neuropathies, occurred in ten procedures. Ten percent of the donations were associated with transient postoperative fever of unknown origin. Increasing donor age was associated with a reduction of the cellularity of the marrow harvest. The use of stored autologous blood permitted the avoidance of blood bank transfusion in 81% of males, 69% of females, and 50% of children. It was concluded that the procedure was associated with a very low risk of complication, but that the involvement of normal donors in such an operation justifies stringent monitoring. 相似文献
62.
Abstract: Our research goal is to report on method of breast cancer detection among young women from a prospective cohort study of primary breast cancer patients, aged 20–49 years, 1990–2008 (n = 2579). Clinical presentation characteristics including race, TNM stage, first degree relative family history, histologic type and method of detection by patient (PtD), physician (PhysD), or mammography (MamD) were chart abstracted. Forward conditional stepwise regression was used to for association with detection method and Kaplan‐Meier for relapse free survival (RFS) analysis. Among 20‐ to 39‐year olds (n = 602) no change in detection method occurred over time with 12% MamD, 7% PhysD, and 81% PtD. Among 40‐ to 49‐year olds, MamD BC increased over time (28% to 58%) and PtD BC decreased (63–36%) (Pearson X2= 72.72, p < .001). Among 20–39/40‐ to 49‐year old MamD cases 31%/32% were stage 0 versus 2%/6% of the PhysD/PtD cases. In two separate conditional logistic regression models, older age at diagnosis and first degree relative BC history were associated with MamD BC for 20‐ to 39‐ and 40‐ to 49‐year olds. Five‐year MamD BC RFS was superior for both age groups (20–39: 94%, 40–49: 94%) compared to PtD BC rates (20–39: 80%, p = .016; 40–49: 88%, p < .001). For PtD BC 20‐ to 39‐year olds had worse RFS (5 year 80%, 10 year 75%) than 40‐ to 49‐year olds (5 year 88%, 10 year 82%) (p = .002) but RFS was equivalent for MamD cases by age. The majority of breast cancers among women 20–49 years were patient detected and mammography detection occurred rarely among youngest women. Lower stage and superior survival among MamD patients support mammography for detecting disease in high risk women aged 30–39 years and 40–49 years. 相似文献
63.
64.
65.
Moore AD; Godwin JD; Muller NL; Naidich DP; Hammar SP; Buschman DL; Takasugi JE; de Carvalho CR 《Radiology》1989,172(1):249-254
The authors retrospectively evaluated radiographs, computed tomographic (CT) scans, and results of pulmonary function tests (when available) for 17 patients with biopsy-proved pulmonary histiocytosis X. In 11 patients, high-resolution CT was used. In 12 patients, CT demonstrated cystic air spaces, usually less than 10 mm in diameter. In three of these 12, cysts were the only abnormality, but in six others, nodules (usually less than 5 mm in diameter) were also present. Two patients had only nodules and one, only emphysema. CT showed that many lesions that appeared reticular on plain radiographs were actually cysts. CT showed no central or peripheral concentration of lesions, but it did reveal that many small nodules were distributed in the centers of secondary lobules around small airways. CT findings correlated better with the diffusing capacity (rho = -0.71) than did the plain radiographic findings (rho = -0.57). Thus, CT was better than radiography at showing the morphology and distribution of lung abnormalities. 相似文献
66.
67.
Ana Gvozdenovic Matthias JE Arlt Carmen Campanile Patrick Brennecke Knut Husmann Yufei Li Walter Born Roman Muff Bruno Fuchs 《Journal of bone and mineral research》2013,28(4):838-847
Formation of metastases in the lungs is the major cause of death in patients suffering from osteosarcoma (OS). Metastases at presentation and poor response to preoperative chemotherapy are strong predictors for poor patient outcome. The elucidation of molecular markers that promote metastasis formation and/or chemoresistance is therefore of importance. CD44 is a plasma membrane glycoprotein that binds to the extracellular matrix component hyaluronan (HA) and has been shown to be involved in metastasis formation in a variety of other tumors. Here we investigated the role of CD44 expression on OS tumor formation and metastasis. High CD44 expression, evaluated with a tissue microarray including samples from 53 OS patients and stained with a pan‐CD44 antibody (Hermes3), showed a tendency (p < 0.08) to shortened overall survival. However, nonresponders and patients with lung metastases and high CD44 expression had significantly poorer prognosis than patients with low CD44 expression. Overexpression of the standard CD44 isoform (CD44s) and its HA‐binding defective mutant R41A in osteoblastic SaOS‐2 cells resulted in HA‐independent higher migration rates and increased chemoresistance, partially dependent on HA. In an orthotopic mouse model of OS, overexpression of CD44s in SaOS‐2 cells resulted in an HA‐dependent increased primary tumor formation and increased numbers of micrometastases and macrometastases in the lungs. In conclusion, although CD44 failed to be an independent predictor for patient outcome in this limited cohort of OS patients, increased CD44 expression was associated with even worse survival in patients with chemoresistance and with lung metastases. CD44‐associated chemoresistance was also observed in vitro, and increased formation of lung metastases was found in vivo in SCID mice. © 2013 American Society for Bone and Mineral Research. 相似文献
68.
69.
70.
AC Winter K Berger JE Buring & T Kurth 《Cephalalgia : an international journal of headache》2009,29(2):269-278
We evaluated the association of body mass index (BMI) with migraine and migraine specifics in a cross-sectional study of 63 467 women aged ≥ 45 years, of whom 12 613 (19.9%) reported any history of migraine and 9195 had active migraine. Compared with women without migraine and a BMI < 23 kg/m2 , women with a BMI ≥ 35 kg/m2 had adjusted odds ratios (ORs) (95% confidence intervals) of 1.03 (0.95, 1.12) for any history of migraine. Findings were similar for active migraineurs. Women with a BMI of ≥ 35 kg/m2 had increased risk for low and high migraine frequency, with the highest estimate for women who reported daily migraine. Compared with women with the lowest associated risk (migraine frequency < 6 times/year; BMI between 27.0 and 29.9 kg/m2 ), women with a BMI ≥ 35 kg/m2 had an OR of daily migraine of 3.11 (1.12, 8.67). Among the women with active migraine, a BMI ≥ 35 kg/m2 was associated with increased risk of phonophobia and photophobia and decreased risk of a unilateral pain characteristic and migraine aura. Our data confirm previous findings that the association between BMI with migraine is limited to migraine frequency and specific migraine features. 相似文献