全文获取类型
收费全文 | 42364篇 |
免费 | 3692篇 |
国内免费 | 1576篇 |
专业分类
耳鼻咽喉 | 274篇 |
儿科学 | 815篇 |
妇产科学 | 429篇 |
基础医学 | 5554篇 |
口腔科学 | 1410篇 |
临床医学 | 3205篇 |
内科学 | 5479篇 |
皮肤病学 | 695篇 |
神经病学 | 3247篇 |
特种医学 | 806篇 |
外国民族医学 | 2篇 |
外科学 | 4663篇 |
综合类 | 6997篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 2179篇 |
眼科学 | 969篇 |
药学 | 2540篇 |
23篇 | |
中国医学 | 6510篇 |
肿瘤学 | 1828篇 |
出版年
2024年 | 143篇 |
2023年 | 710篇 |
2022年 | 1222篇 |
2021年 | 1730篇 |
2020年 | 1733篇 |
2019年 | 1406篇 |
2018年 | 1313篇 |
2017年 | 1460篇 |
2016年 | 1466篇 |
2015年 | 1527篇 |
2014年 | 2807篇 |
2013年 | 3026篇 |
2012年 | 2568篇 |
2011年 | 3848篇 |
2010年 | 2505篇 |
2009年 | 2196篇 |
2008年 | 2060篇 |
2007年 | 1958篇 |
2006年 | 1731篇 |
2005年 | 1464篇 |
2004年 | 1314篇 |
2003年 | 1175篇 |
2002年 | 881篇 |
2001年 | 743篇 |
2000年 | 651篇 |
1999年 | 542篇 |
1998年 | 464篇 |
1997年 | 467篇 |
1996年 | 424篇 |
1995年 | 432篇 |
1994年 | 424篇 |
1993年 | 320篇 |
1992年 | 252篇 |
1991年 | 247篇 |
1990年 | 206篇 |
1989年 | 199篇 |
1988年 | 174篇 |
1987年 | 139篇 |
1986年 | 124篇 |
1985年 | 219篇 |
1984年 | 195篇 |
1983年 | 123篇 |
1982年 | 110篇 |
1981年 | 96篇 |
1980年 | 104篇 |
1979年 | 74篇 |
1978年 | 62篇 |
1977年 | 46篇 |
1976年 | 53篇 |
1973年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
81.
82.
83.
Dittmar Böckler Hardy Schumacher Klaus Klemm Marcel Riemensperger Philipp Geisbüsch Drosos Kotelis Harry Rotert Jens-Rainer Allenberg 《Langenbeck's archives of surgery / Deutsche Gesellschaft fur Chirurgie》2007,392(6):715-723
OBJECTIVES: to report our experience with hybrid vascular procedures in patients with pararenal and thoracoabdominal aortic pathologies. METHODS: 68 patients were treated for thoracoabdominal aortic pathologies between October 1999 and February 2004; 19 patients (16 men; mean age 68, range 40-79) with high risk for open thoracoabdominal repair were considered to be candidates for combined endovascular and open repair. Aortic pathologies included five thoracoabdominal Crawford I aneurysms, one postdissection expanding aneurysm, three symptomatic plaque ruptures (Crawford IV), five combined thoracic descending and infrarenal aneurysms with a healthy visceral segment, three juxtarenal or para-anastomotic aneurysms, and two patients with simultaneous open aortic arch replacement and a rendezvous maneuver for thoracic endografting. Commercially available endografts were implanted with standardized endovascular techniques after revascularization of visceral and renal arteries. RESULTS: Technical success was 95%. One patient developed a proximal type I endoleak after chronic expanding type B dissection and currently is waiting conversion. Nine patients underwent elective, five emergency and five urgent (within 24 h) repair. 17 operations were performed simultaneously, and 2 as a staged procedure. Postoperative complications include two retroperitoneal hemorrhages, and one patient required long-term ventilation with preexisting subglottic tracheal stenosis. Thirty-day mortality was 17% (one multiple organ failure, one secondary rupture after open aortic arch repair, one myocardial infarction). Paraplegia or acute renal failure were not observed. Total survival rate was to 83% with a mean follow-up of 30 months. CONCLUSIONS: Midterm results of combined endovascular and open procedures in the thoracoabdominal aorta are encouraging in selected high risk patients. Staged interventions may reduce morbidity. 相似文献
84.
D. M. Richards N. Zhang S. L. Dalheimer D. L. Mueller 《American journal of transplantation》2007,7(10):2269-2278
To investigate the mechanism of CD4(+) T-cell help during the activation and differentiation of directly alloreactive CD8(+) T cells, we examined the development of obliterative airways disease (OAD) following transplantation of airways into fully mismatched recipient mice deficient in CD4(+) T cells. BALB/c trachea allografts became fibrosed significantly less frequently in B6 CD4(-/-) recipients as compared to wildtype controls. Furthermore, class I-directed cytotoxicity failed to develop in the absence of CD4(+) T cells. The infiltration of graft tissue by primed L(d)-specific directly alloreactive 2C CD8(+) T cells was not found to depend on the presence of CD4(+) T cells. Nevertheless, graft-infiltrating 2C CD8(+) T cells failed to express CD69 and granzyme B when CD4(+) T-cell help was unavailable. Importantly, reconstitution of B6 CD4(-/-) recipient mice with graft peptide-specific TCR-Tg CD4(+) T cells (OT-II or TEa) capable of recognizing antigen only on recipient APC allowed for full expression of CD69 and granzyme B by the directly alloreactive CD8(+) T cells and restored the capacity of recipients to reject their allografts. These results demonstrate that indirectly alloreactive CD4(+) T cells ensure the optimal activation and differentiation of graft-infiltrating directly alloreactive CD8(+) T cells independent of donor APC recognition. 相似文献
85.
目的分析Dandy—Walker综合征的临床及cT与MR!影像特征。方法采用cT与MRI常规扫描,对12例Dandy—Walker综合征的临床表现、CT与MRI征象进行回顾性分析;结果12例Dandy—Walker综合征的CT与MRI表现归纳为①小脑蚓部缺失,小脑半球发育不良、完全分离,分离的小脑半球可以不对称;②第四脑室呈囊状、扇形、三角形显著扩张或后颅窝巨大囊状阴影与第四脑室相通;③窦汇异常抬高,越过人字缝/天幕抬高;④幕上脑室对称性扩张,脑积水。结论对Dandy—Walker综合征的诊断,CT扫描能够显示后颅凹及天幕上下脑的形态与结构,其CT表现具特征性;MRI可多平面扫描,无骨质伪影,显示后颅凹优于CT,在矢状面上可显示小脑、第四脑室、导水管、后颅凹囊肿以及与天幕的关系。CT与MRI扫描对Dandy—Walker综合征能够做出定性诊断,是术前诊断的主要依据,检查无痛苦,有重要的诊断和鉴别诊断价值。 相似文献
86.
87.
不同临床和病理分型对肝门部胆管癌切除术预后的影响 总被引:2,自引:0,他引:2
目的 研究临床和病理分型与肝门部胆管癌切除术疗效的关系。方法总结1993年至2004年在解放军总医院肝胆外科手术切除的肝门部胆管癌198例病例资料。结果临床分型Ⅰ型34例,Ⅱ型60例,Ⅲa型27例,Ⅲb型33例,Ⅳ型19例,Ⅴa型6例。Ⅴb型19例。病理高分化腺癌35例,中分化腺癌52例,低分化腺癌54例,三者的中位生存期分别为29.5、11、5.5个月;病理切缘阴性者与切缘阳性者生存率有显著性差异(P 〈0.05)。手术并发症出现率41.4%,围手术期死亡1例。结论肝门部胆管癌根据临床分型进行相应的手术治疗;病理切缘阴性是影响预后的主要因素之一;围手术期正确处理,是减少手术并发症,提高患者生活质量和延长生存期的关键。 相似文献
88.
分析年龄、有无宫腔操作史等病因;注重问诊、妇科及其辅助检查等诊断方法;根据年龄及有无人流史等进行辨证施治,从冲任不足和冲任虚瘀2个方面诊治月经过少,收效较好。 相似文献
89.
Yoichiro Hosokawa D.D.S. D.D.Sc. Kazuyuki Minowa D.D.S. Satoru Abe M.D. Keiichi Ohmori D.D.S. D.D.Sc. Michio Yamasaki M.D. D.M.Sc. Masanobu Shindoh D.D.S. D.D.Sc. Tadashi Iizuka D.D.S. D.D.Sc. Mohiuddin Ahmed B.D.S. Akira Amemiya D.D.S. D.D.Sc. 《Oral Radiology》1991,7(1):1-6
A case of an odontogenic tumor which invaded the intracranial space from the mandible is reported. Judging from the radiographic
images it was similar to a malignant tumor. The patient died 17 years after the first visit. According to the final pathological
diagnosis, it was malignant odontogenic mixed tumor of low grade which did not belong to any of the WHO classification. 相似文献
90.
Müllerian duct regression is first apparent in male pouch young of the tammar wallaby (Macropus eugenii) 6–7 days after birth and, as in eutherian mammals, is characterised by a condensation of the periductal mesenchyme into
a whorl around the ductal epithelial cells. A decrease in the density of the extracellular matrix was observed in the region
of the whorl. In contrast to eutherian mammals no changes were observed in the mean outer diameter of the Müllerian duct during
the early stages of regression. The time at which these mesenchymal changes occur corresponds to the period of Müllerian inhibiting
substance secretion in the postnatal tammar testis.
Accepted: 25 February 1997 相似文献