全文获取类型
收费全文 | 6498篇 |
免费 | 574篇 |
国内免费 | 564篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 161篇 |
妇产科学 | 48篇 |
基础医学 | 716篇 |
口腔科学 | 91篇 |
临床医学 | 882篇 |
内科学 | 1166篇 |
皮肤病学 | 106篇 |
神经病学 | 383篇 |
特种医学 | 539篇 |
外国民族医学 | 10篇 |
外科学 | 556篇 |
综合类 | 1056篇 |
现状与发展 | 2篇 |
预防医学 | 340篇 |
眼科学 | 139篇 |
药学 | 684篇 |
2篇 | |
中国医学 | 299篇 |
肿瘤学 | 422篇 |
出版年
2024年 | 17篇 |
2023年 | 77篇 |
2022年 | 213篇 |
2021年 | 293篇 |
2020年 | 190篇 |
2019年 | 197篇 |
2018年 | 194篇 |
2017年 | 170篇 |
2016年 | 168篇 |
2015年 | 263篇 |
2014年 | 320篇 |
2013年 | 259篇 |
2012年 | 434篇 |
2011年 | 425篇 |
2010年 | 308篇 |
2009年 | 241篇 |
2008年 | 292篇 |
2007年 | 319篇 |
2006年 | 312篇 |
2005年 | 283篇 |
2004年 | 220篇 |
2003年 | 245篇 |
2002年 | 210篇 |
2001年 | 181篇 |
2000年 | 162篇 |
1999年 | 153篇 |
1998年 | 172篇 |
1997年 | 163篇 |
1996年 | 173篇 |
1995年 | 142篇 |
1994年 | 135篇 |
1993年 | 105篇 |
1992年 | 68篇 |
1991年 | 74篇 |
1990年 | 54篇 |
1989年 | 55篇 |
1988年 | 60篇 |
1987年 | 44篇 |
1986年 | 49篇 |
1985年 | 45篇 |
1984年 | 14篇 |
1983年 | 24篇 |
1982年 | 21篇 |
1981年 | 23篇 |
1980年 | 17篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 14篇 |
1976年 | 13篇 |
1975年 | 7篇 |
排序方式: 共有7636条查询结果,搜索用时 15 毫秒
991.
电视胸腔镜手术在胸外科的应用 总被引:2,自引:0,他引:2
目的探讨电视胸腔镜手术(video-assisted thoracoscopic surgery,VATS)在胸外科的应用. 方法回顾分析1998年7月~2002年12月78例胸腔镜手术的临床资料.其中:自发性气胸肺大疱切除40例,胸外伤探查12例,肺包块楔形切除9例,胸膜活检 胸膜固定6例,纵隔肿瘤切除4例,肺叶切除4例,肺叶切除术后支气管胸膜瘘2例,食管平滑肌瘤切除1例. 结果无一例中转开胸,5例因胸膜顶粘连辅助小切口.3例中老年自发性气胸术后持续漏气,分别于第7,8,13天拔除胸管,其余均在48h内拔除胸管.5例引流管口延期愈合.手术并发症发生率10.3%(8/78). 结论 VATS在胸外科有广阔的发展空间,一次性耗材价格昂贵限制其临床应用,腔镜下缝合技术或打结技术的应用比较适合目前的国情,节省医疗费用. 相似文献
992.
The contribution of proton spectroscopic (PS) imaging to magnetic resonance (MR) imaging of the liver was assessed at 0.5 T in 55 patients with known or suspected hepatic malignancy. PS images were compared subjectively with T1- and T2-weighted spin-echo (SE) images for hepatic lesion detection and conspicuity. For hepatic metastases (n = 27), PS images were equal to T1-weighted images in lesion detection in 17 patients but showed fewer lesions in five patients and false-negative results in two. When compared with T2-weighted images, PS images depicted more lesions in six patients, an equal number of lesions in 18, and fewer lesions in two. Hepatomas (n = 8) were detected with each sequence in all patients. Hepatomas were often more conspicuous on PS images than on T2-weighted images; they were of equal conspicuity on PS and T1-weighted images in most cases. Whereas fatty infiltration (n = 16) appeared on PS images as areas of low signal intensity similar to that of paraspinal muscle, it produced no detectable abnormality on either T1- or T2-weighted images. PS imaging is inferior to T1-weighted SE imaging in the detection of hepatic metastases. The major role of PS imaging at intermediate field strength is to differentiate focal fatty infiltration from hepatic metastases. 相似文献
993.
采用摘除甲状旁腺后的慢性肾功能衰竭(chronicrenalfailure,CRF)大鼠,以观察其对T、B细胞功能的影响。结果显示:CRF时T、B细胞功能明显低下,而摘除甲状旁腺可提高CRF鼠T细胞转化与IL-2水平以及B细胞抗体分泌滴度,提示CRF时T、B细胞功能缺陷与继发性甲旁亢有关。 相似文献
994.
Relation of deranged neonatal cerebral oxidative metabolism with neurodevelopmental outcome and head circumference at 4 years 总被引:3,自引:0,他引:3
SC Roth FRCR J. Baudin PhD E. Cady BSc K. Johal MBBS JP Townsend J S. Wyatt E O R. Reynolds FRS. FRCP A L. Stewart MRCPH 《Developmental medicine and child neurology》1997,39(11):718-725
Cerebral oxidative metabolism was studied using phosphorus magnetic resonance spectroscopy during the first week of life and neurodevelopmental outcome was assessed at 4 years in 62 infants who had clinical and/or biochemical evidence consistent with birth asphyxia (critically impaired intrapartum gas exchange). Twenty-one died and the neurodevelopmental status of the 41 who survived was assessed by a range of tests at age 4 years. The minimum recorded values for the cerebral phosphocreatine:inorganic phosphate concentration ratio (an index of oxidative metabolism) were related to outcome. The results showed significant relations between the extent of derangement of neonatal oxidative metabolism and a range of adverse outcomes, including death, and at 4 years reduced head growth and the presence and severity of neuromotor impairments, overall neurodevelopmental impairments, and cognitive functioning. Strong correlations between the extent of derangement of neonatal oxidative metabolism and outcome at 1 and 4 years were also shown. We conclude that the severities of adverse outcomes at 1 and 4 years of age were closely related to the extent of cerebral energy derangement in the first week of life, and we also conclude that primary intrapartum hypoxic-ischaemic cerebral injury was generally responsible for the events that led to death, microcephaly, and impaired 相似文献
995.
996.
997.
Central pontine myelinolysis and its imitators: MR findings 总被引:5,自引:0,他引:5
The clinical, radiologic, and neuropathologic findings in 13 patients with central pontine myelinolysis were reviewed. Antemortem computed tomography (CT) had been performed in nine, and ante- or postmortem magnetic resonance (MR) imaging in 11. Chronic alcoholism or rapid correction of hyponatremia was present in over 75% of cases. One CT scan was positive, but only on retrospective review. In all but one patient, MR imaging eventually revealed an abnormality within the pons; in two patients the initial study was normal. The lesions varied in shape, with peripheral involvement in two patients and extrapontine involvement in four. The abnormality was smaller at 6-month follow-up in one patient and unchanged at 1 year in another. One patient never had a demonstrable pontine lesion but did have symmetric basal ganglia abnormalities, which were consistent with extrapontine myelinolysis. MR imaging disclosed similar central pontine alterations resulting from infarct, metastasis, glioma, multiple sclerosis, encephalitis, and radiation or chemotherapy; thus, such changes are not unique. 相似文献
998.
Microspectrophotometric measurement of the cellular DNA content of 73 cervical carcinoma specimens was carried out. The tumor was diploid in 7 cases, tetraploid in 2 and aneuploid in 64. The cases could be divided into hyperploid and hypoploid groups using the DNA index of 1.5 as demarcation. The DNA content was found to be closely related to the histologic types and mitotic figures of the tumors. Hyperploidy was more frequently seen in large-cell carcinoma and hypoploidy in small-cell varieties. 相似文献
999.
The authors report a case of a hepatic artery aneurysm that simulated a mass in the head of the pancreas. The correct diagnosis was made preoperatively based on several findings: curvilinear calcification within the mass on CT, a well-defined cystic collection on ultrasound, absence of biliary duct dilatation or jaundice, and presence of other aneurysms. 相似文献
1000.
DNA content of the severe dysplasia cells in the esophageal epithelium was quantitatively analysed using flow cytometry and compared with those of the normal, mild dysplasia and cancer cells. The results showed that DNA index of the severe dysplasia cells was 1.27 +/- 0.11 and there was a significant difference between its value and those of the normal (1.0 +/- 0.02), mild dysplasia (1.01 +/- 0.03) and cancer cells (1.73 +/- 0.35). The DNA content of severe dysplasia cells lies between the normal and cancer cells. The hyperplasia degree of the severe dysplasia cells parallels their DNA contents. This study indicates that flow cytometry is a useful supplementary tool for diagnosis of the tumor. 相似文献