全文获取类型
收费全文 | 12727篇 |
免费 | 849篇 |
国内免费 | 373篇 |
专业分类
耳鼻咽喉 | 430篇 |
儿科学 | 217篇 |
妇产科学 | 87篇 |
基础医学 | 678篇 |
口腔科学 | 215篇 |
临床医学 | 1528篇 |
内科学 | 3573篇 |
皮肤病学 | 15篇 |
神经病学 | 283篇 |
特种医学 | 703篇 |
外国民族医学 | 2篇 |
外科学 | 3529篇 |
综合类 | 1203篇 |
预防医学 | 167篇 |
眼科学 | 34篇 |
药学 | 309篇 |
3篇 | |
中国医学 | 37篇 |
肿瘤学 | 936篇 |
出版年
2024年 | 24篇 |
2023年 | 327篇 |
2022年 | 551篇 |
2021年 | 748篇 |
2020年 | 670篇 |
2019年 | 619篇 |
2018年 | 576篇 |
2017年 | 459篇 |
2016年 | 481篇 |
2015年 | 482篇 |
2014年 | 1098篇 |
2013年 | 848篇 |
2012年 | 657篇 |
2011年 | 801篇 |
2010年 | 544篇 |
2009年 | 566篇 |
2008年 | 604篇 |
2007年 | 561篇 |
2006年 | 494篇 |
2005年 | 386篇 |
2004年 | 318篇 |
2003年 | 261篇 |
2002年 | 238篇 |
2001年 | 191篇 |
2000年 | 164篇 |
1999年 | 160篇 |
1998年 | 126篇 |
1997年 | 126篇 |
1996年 | 89篇 |
1995年 | 91篇 |
1994年 | 101篇 |
1993年 | 77篇 |
1992年 | 78篇 |
1991年 | 68篇 |
1990年 | 41篇 |
1989年 | 38篇 |
1988年 | 30篇 |
1987年 | 31篇 |
1986年 | 29篇 |
1985年 | 32篇 |
1984年 | 22篇 |
1983年 | 17篇 |
1982年 | 27篇 |
1981年 | 16篇 |
1980年 | 17篇 |
1979年 | 12篇 |
1978年 | 14篇 |
1976年 | 12篇 |
1975年 | 8篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
61.
Based upon detailed dissections of the lymphatic system in adult cadavers, the lymphatic drainage of the gallbladder was divided
into three pathways: (1) The cholecystoretropancreatic pathway, which had two routes, one running spirally from the anterior
surface of the common bile duct to the right rear, and the other running almost straight down from the posterior surface of
the common bile duct. These routes converged at the principal retroportal node at the posterior surface of the head of the
pancreas. (2) The cholecysto-celiac pathway; this was the route running to the left through the hepatoduodenal ligament to
reach the celiac nodes. (3) The cholecysto-mesenteric pathway; this was the route running to the left in front of the portal
vein to connect with the nodes at the superior mesenteric root. The cholecysto-retropancreatic pathway can be regarded as
the main pathway, and the principal retroportal node appeared to be critical as the main terminal node in the visceral lymphatic
system of the gallbladder. These three pathways converged with the abdomino-aortic lymph nodes near the left renal vein, and
the nodes in the interaortico-caval space were considered to be of particular importance.
Offprint requests to: M. Ito 相似文献
62.
Malcolm E. Richardson Samuel Menahem James L. Wilkinson 《International journal of cardiology》1991,30(3):351-353
In this report, we give details of two families in which fixed subaortic stenosis was found in more than one member. It is rare for this entity to show familial incidence. 相似文献
63.
Luca Oscar Redaelli De Zinis Andrea Bolzoni Cesare Piazza Piero Nicolai 《European archives of oto-rhino-laryngology》2006,263(12):1131-1135
Lymph node (LN) metastases represent the most important negative prognostic factor in squamous cell carcinoma (SCC) of the oral cavity, even though controversies still exist regarding their management. The aim of this study was to retrospectively analyze our experience in surgical management of SCC of the oral cavity with particular focus on the prevalence and localization of lymph nodal metastases and recurrences. The clinical records of 89 consecutive patients treated from 1983 to 2002 by concomitant surgery on both the T and N sites, excluding those undergoing salvage surgery, were reviewed. A total of 119 neck dissections (ND) were performed. Survival outcomes were calculated by the Kaplan–Meier method, while univariate comparisons by the log-rank and non-parametric tests were performed between different groups of patients. Five-year overall and determinate survivals were 50 and 57%, respectively. LN metastases were observed in 52% (56% of these showing extracapsular spread) and their presence strongly correlated with determinate survival (p < 0.0001). The prevalence of clinical and occult nodal disease was not related to the pT status. Neck levels II (59%) and I (56%) were most frequently involved. Metastases to level IV accounted for 15% of positive LN, even though 28% of them turned out to be skip metastases. Five neck recurrences were observed, only one of which was salvaged by surgery. The high prevalence of clinical and occult LN metastases in this setting suggests that ND should be performed on a nearly routine basis, even for lesions with a low-T category and a cN0 neck. Moreover, ND should always encompass level IV due to the possibility of skip metastases, particularly in tumors involving the oral tongue. In patients with a cN+ neck, levels from I to V should be addressed, particularly in the presence of metastases at levels III and IV. 相似文献
64.
A 32-year-old man with distal skeletal manifestations of Marfan's syndrome had experienced shortness of breath and orthopnea for one month. Physical examination showed the presence of severe aortic regurgitation. Both noninvasive and invasive studies revealed that the aortic regurgitation was induced by previously undescribed peculiar and unusual etiology: diastolic prolapse of a circumferentially dissected tubular intimal flap into the left ventricle. The patient underwent surgical repair with striking clinical improvement. 相似文献
65.
66.
腹主动脉瘤动脉壁血管平滑肌细胞增殖及凋亡的研究 总被引:3,自引:0,他引:3
目的研究腹主动脉瘤 (abdominalaorticaneurysm ,AAA)在发病不同时期动脉壁平滑肌细胞 (smoothmusclecells,SMC)增殖与凋亡的改变。方法建立大鼠AAA模型 ,分别于术后 3d、1、2、3、4周切取腹主动脉 ,应用原位DNA片段末端标记 (TUNEL)和免疫组织化学方法检测腹主动脉壁中SMC凋亡和相关基因bcl 2、bax蛋白以及增殖细胞核抗原 (PCNA)、α 血管平滑肌肌动蛋白(α actin)的表达。结果TUNEL及PCNA表达高峰时段分别为术后 2~ 3周和 1周 ;术后 3d至 1周凋亡细胞少于PCNA阳性SMC ,2~ 4周多于PCNA阳性SMC且SMC数量明显减少 ;bcl 2与bax蛋白表达分别于术后 1、3周达到峰值 (P <0 0 1)。结论动脉壁SMC增殖和凋亡的失衡与AAA发病密切相关 ;bcl 2与bax基因参与了对AAA动脉壁中SMC凋亡的调控。 相似文献
67.
68.
T. V. Bilfinger F. C. Seifert A. M. Vallone T. M. Biancaniello 《Pediatric cardiology》1994,15(2):100-102
Summary Although recognized by pediatric cardiac surgeons, aortic insufficiency as a technical complication after tetralogy of Fallot repair is poorly documented, especially if it occurs late. The case of a boy with aortic insufficiency 10 years after complete tetralogy repair is described. No documentation in the literature other than summary statements in textbooks of this occurence was found. 相似文献
69.
Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention. 相似文献
70.
The aortic nipple, a small “pseudotumor” adjacent to the aortic arch, is the left superior intercostal vein. In our series
of 40 patients it was demonstrated in six; all had a right upper thoracic mass and four had a superior vena caval syndrome.
Coronal magnetic resonance, images (MRI) of the thorax were superior to all other imaging methods in demonstrating the nipple.
It is concluded that in patients with masses in the right upper chest, coronal MR chest examinations are valuable in demonstrating
an aortic nipple, a sign of impending present superior vena caval or innominate, vein obstruction. 相似文献