全文获取类型
收费全文 | 71294篇 |
免费 | 5977篇 |
国内免费 | 2147篇 |
专业分类
耳鼻咽喉 | 787篇 |
儿科学 | 939篇 |
妇产科学 | 1640篇 |
基础医学 | 10632篇 |
口腔科学 | 1811篇 |
临床医学 | 6482篇 |
内科学 | 14033篇 |
皮肤病学 | 1224篇 |
神经病学 | 4927篇 |
特种医学 | 2154篇 |
外国民族医学 | 9篇 |
外科学 | 9913篇 |
综合类 | 5435篇 |
现状与发展 | 4篇 |
一般理论 | 10篇 |
预防医学 | 4023篇 |
眼科学 | 2112篇 |
药学 | 6266篇 |
6篇 | |
中国医学 | 1314篇 |
肿瘤学 | 5697篇 |
出版年
2023年 | 420篇 |
2022年 | 774篇 |
2021年 | 1230篇 |
2020年 | 800篇 |
2019年 | 1111篇 |
2018年 | 1680篇 |
2017年 | 1364篇 |
2016年 | 1349篇 |
2015年 | 1622篇 |
2014年 | 2076篇 |
2013年 | 2494篇 |
2012年 | 3520篇 |
2011年 | 3549篇 |
2010年 | 2132篇 |
2009年 | 1943篇 |
2008年 | 2918篇 |
2007年 | 3035篇 |
2006年 | 2944篇 |
2005年 | 2597篇 |
2004年 | 2263篇 |
2003年 | 2102篇 |
2002年 | 2021篇 |
2001年 | 5143篇 |
2000年 | 5046篇 |
1999年 | 4370篇 |
1998年 | 1553篇 |
1997年 | 1188篇 |
1996年 | 765篇 |
1995年 | 610篇 |
1994年 | 559篇 |
1993年 | 486篇 |
1992年 | 2134篇 |
1991年 | 1859篇 |
1990年 | 1691篇 |
1989年 | 1626篇 |
1988年 | 1411篇 |
1987年 | 1297篇 |
1986年 | 1154篇 |
1985年 | 959篇 |
1984年 | 631篇 |
1983年 | 497篇 |
1982年 | 294篇 |
1981年 | 219篇 |
1980年 | 176篇 |
1979年 | 316篇 |
1978年 | 109篇 |
1975年 | 81篇 |
1974年 | 88篇 |
1973年 | 109篇 |
1972年 | 81篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
82.
83.
84.
Tick-borne encephalitis (TBE) virus is an important human pathogenic flavivirus that is endemic in Europe and Asia. The disease can be effectively prevented by inactivated vaccines and vaccination breakthroughs (VBTs) are rare. We investigated the characteristics of antibody responses in such VBTs in comparison to those in unvaccinated TBE patients. In contrast to the unvaccinated controls, most of the VBTs displayed a delayed IgM antibody response and had high avidity and strongly neutralizing antibodies already in the first sample taken upon hospitalization. The antibody profile of these patients therefore had the characteristics of an anamnestic immune response. In the VBTs analyzed, immunological priming and memory were apparently not sufficient or fast enough to prevent the disease. 相似文献
85.
Christian J. Sauder Cheryl X. Zhang Malen A. Link W. Paul Duprex Kathryn M. Carbone Steven A. Rubin 《Vaccine》2009
The recent global resurgence of mumps has drawn attention to the continued need for robust mumps immunization programs. Unfortunately, some vaccines derived from inadequately attenuated vaccine strains of mumps virus have caused meningitis in vaccinees, leading to withdrawal of certain vaccine strains from the market, public resistance to vaccination, or in some cases, cessation of national mumps vaccination programs. The most widely implicated mumps vaccine in cases of postvaccination meningitis is derived from the Urabe AM9 strain, which remains in use in some countries. The Urabe AM9 vaccine virus has been shown to exhibit a considerable degree of nucleotide and amino acid heterogeneity. Some studies have specifically implicated variants containing a lysine residue at amino acid position 335 in the hemagglutinin-neuraminidase (HN) protein with neurotoxicity, whereas a glutamic acid residue at this position was associated with attenuation. To test this hypothesis we generated two modified Urabe AM9 cDNA clones coding either for a lysine or a glutamic acid at position 335 in the HN gene. The two viruses were rescued by reverse genetics and characterized in vitro and in vivo. Both viruses exhibited similar growth kinetics in neuronal and non-neuronal cell lines and were of similar neurotoxicity when tested in rats, suggesting that amino acid 335 is not a crucial determinant of Urabe AM9 growth or neurovirulence. 相似文献
86.
Carcinoma arising from an epiphrenic diverticulum: a frequently misdiagnosed disease. 总被引:1,自引:0,他引:1
Epiphrenic diverticulum is rare, comprising of about 10% of all esophageal diverticula. Carcinoma arising within such a diverticulum is even less common. We report on two patients with squamous cell carcinoma arising from an epiphrenic diverticulum. Some features of malignant change related to the epiphrenic diverticula were misdiagnosed or missed in our cases and other reports due to lack of clinical experience. It is important to exclude the possibility of malignancy as this is vital for surgical planning. Although the prognosis for patients with malignancy arising from an epiphrenic diverticulum is generally poor, a high index of suspicion may increase the chance of cure. 相似文献
87.
咬肌与颅面形态的关系 总被引:3,自引:0,他引:3
目的探讨咬肌与颅面形态之间的关系,了解咬肌体积与邻近骨骼结构的大小及形态的相关性。方法对40例要求改变脸型者进行磁共振成像(MRI)测量,人体测量,头部正位、侧位和下颌骨曲面断层X线检查,测量并计算咬肌体积(MsV),测量头长(HL)、头宽(HB)、面长(FL)、面宽(FB)、下颌角间宽(IB)、下颌骨体长(CL)、下颌角切线长(MAL)、下颌角角度(JA),计算颜面形态指数FI(FL/FB)、头颅指数C(IHB/HL)。用SPSS11.5软件统计分析MsV与HI。HB、FL、FB、IB、CL、MAL、JA、FI、CI之间的相关性。结果MsV与JA呈明显负相关,与CL、MAL、IB、FB、HL呈明显正相关,与CL、FI、HB无明显相关性。结论咬肌肥大可能是方脸面型的成因之一,是影响面型的重要因素。 相似文献
88.
A CT-free, intra-operative planning and navigation system for minimally invasive anterior spinal surgery - an accuracy study. 总被引:1,自引:0,他引:1
B Maier G Zheng C Ploss X Zhang K Welle L-P Nolte I Marzi 《Computer aided surgery》2007,12(4):233-241
OBJECTIVE: A comprehensive study was performed to evaluate the accuracy of a newly developed CT-free, intra-operative planning and navigation system for anterior spine surgery. MATERIALS AND METHODS: Instruments and an image intensifier were tracked using the SurgiGATE navigation system. A laboratory study was performed on 27 plastic vertebrae. Fiducial markers were implanted in the vertebrae for accuracy evaluation purposes, and a dynamic reference base was placed on the vertebrae to establish a patient coordinate system (P-COS). Two fluoroscopic images were used for intra-operative planning. The graft bed plan was recorded in P-COS, followed by surgical formation of the graft bed, which was visualized. To evaluate the accuracy, the vertebrae were scanned with CT, and the markers were used to calculate an accurate paired-point registered transformation between the CT coordinate system and P-COS. RESULTS: Using the new SPO module, accurate planning and navigation of a resection of the vertebral body is possible using two fluoroscopic images. The overall mean error between the planned resection volume and the actual resection was 0.98 mm. In addition, the module can serve as an educational tool for training spine surgeons. CONCLUSIONS: The new fluoroscopy-based system can be used safely for accurate performance of anterior resection during spondylodesis. New methods for safe and accurate registration during anterior spine surgery need to be developed. 相似文献
89.
90.
Three patients who presented with scrotal swelling within a few days of inguinal herniorrhaphy are reported. Ultrasonography scans performed in these patients all demonstrated features suspicious of recurrence of hernia. One patient underwent surgical exploration, which revealed only a scrotal haematoma without evidence of recurrent hernia. The other two patients were managed conservatively because clinically the swellings were regarded to be more compatible with haematoma. Both patients had subsequent resolution of the scrotal swelling with no clinical evidence of recurrence of hernia on follow‐up. It is concluded that sonographic diagnosis of recurrence of hernia shortly after inguinal herniorrhaphy can occasionally be misleading. 相似文献