全文获取类型
收费全文 | 136244篇 |
免费 | 8380篇 |
国内免费 | 1259篇 |
专业分类
耳鼻咽喉 | 2136篇 |
儿科学 | 2157篇 |
妇产科学 | 2064篇 |
基础医学 | 21765篇 |
口腔科学 | 3230篇 |
临床医学 | 12618篇 |
内科学 | 24737篇 |
皮肤病学 | 4352篇 |
神经病学 | 11071篇 |
特种医学 | 7715篇 |
外科学 | 18046篇 |
综合类 | 613篇 |
现状与发展 | 3篇 |
一般理论 | 28篇 |
预防医学 | 7109篇 |
眼科学 | 3537篇 |
药学 | 12191篇 |
中国医学 | 1530篇 |
肿瘤学 | 10981篇 |
出版年
2023年 | 963篇 |
2022年 | 2920篇 |
2021年 | 4707篇 |
2020年 | 2317篇 |
2019年 | 3193篇 |
2018年 | 3972篇 |
2017年 | 3241篇 |
2016年 | 4248篇 |
2015年 | 5872篇 |
2014年 | 6980篇 |
2013年 | 8136篇 |
2012年 | 12079篇 |
2011年 | 11582篇 |
2010年 | 6691篇 |
2009年 | 5778篇 |
2008年 | 8127篇 |
2007年 | 7691篇 |
2006年 | 6964篇 |
2005年 | 6417篇 |
2004年 | 5622篇 |
2003年 | 4902篇 |
2002年 | 4240篇 |
2001年 | 3202篇 |
2000年 | 2968篇 |
1999年 | 2276篇 |
1998年 | 973篇 |
1997年 | 734篇 |
1996年 | 551篇 |
1995年 | 485篇 |
1994年 | 408篇 |
1993年 | 356篇 |
1992年 | 790篇 |
1991年 | 751篇 |
1990年 | 673篇 |
1989年 | 596篇 |
1988年 | 513篇 |
1987年 | 500篇 |
1986年 | 357篇 |
1985年 | 389篇 |
1984年 | 281篇 |
1983年 | 218篇 |
1982年 | 142篇 |
1981年 | 176篇 |
1980年 | 144篇 |
1979年 | 247篇 |
1978年 | 186篇 |
1977年 | 144篇 |
1976年 | 144篇 |
1974年 | 150篇 |
1973年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
Hyun Jong Choi Jong Ho Moon Yun Nah Lee Hyun Su Kim Ji Su Ha Tae Hoon Lee Sang‐Woo Cha Young Deok Cho Sang‐Heum Park 《Digestive endoscopy》2015,27(7):772-775
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS. 相似文献
14.
15.
16.
17.
In this paper, we introduce a new type of troubled-cell indicator to improve
hybrid weighted essentially non-oscillatory (WENO) schemes for solving the hyperbolic conservation laws. The hybrid WENO schemes selectively adopt the high-order
linear upwind scheme or the WENO scheme to avoid the local characteristic decompositions and calculations of the nonlinear weights in smooth regions. Therefore,
they can reduce computational cost while maintaining non-oscillatory properties in
non-smooth regions. Reliable troubled-cell indicators are essential for efficient hybrid
WENO methods. Most of troubled-cell indicators require proper parameters to detect
discontinuities precisely, but it is very difficult to determine the parameters automatically. We develop a new troubled-cell indicator derived from the mean value theorem
that does not require any variable parameters. Additionally, we investigate the characteristics of indicator variable; one of the conserved properties or the entropy is considered as indicator variable. Detailed numerical tests for 1D and 2D Euler equations are
conducted to demonstrate the performance of the proposed indicator. The results with
the proposed troubled-cell indicator are in good agreement with pure WENO schemes.
Also the new indicator has advantages in the computational cost compared with the
other indicators. 相似文献
18.
Can EGFR mutation status be reliably determined in pre‐operative needle biopsies from adenocarcinomas of the lung? 下载免费PDF全文
Kim Hein Lindahl Flemming Brandt Sørensen Søren Peter Jonstrup Karen Ege Olsen Siegfried Loeschke 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(4):289-297
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis. 相似文献
19.
Michelle E. Wilson Charles Kim Jacqueline Carrasco 《Orbit (Amsterdam, Netherlands)》2016,35(5):288-291
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression. 相似文献
20.
Kun‐Yong Sung Seungkoo Lee Yeonjin Jeong Sang‐Yeul Lee 《The Australasian journal of dermatology》2021,62(1):60-63
A classic pilomatricoma, which usually presents with an asymptomatic, solitary, firm, subcutaneous nodule in the head, neck, or extremities of the paediatric population, is easily diagnosed based on its characteristic clinical and histopathological features. However, its variants often pose particular diagnostic challenges to clinicians due to their rarity and diverse clinicopathological features. We present a new pseudocystic variant, manifesting as solid lesions floating in a fluid‐filled sac. 相似文献