全文获取类型
收费全文 | 497281篇 |
免费 | 35734篇 |
国内免费 | 15414篇 |
专业分类
耳鼻咽喉 | 4943篇 |
儿科学 | 12632篇 |
妇产科学 | 8899篇 |
基础医学 | 50290篇 |
口腔科学 | 10468篇 |
临床医学 | 51408篇 |
内科学 | 72687篇 |
皮肤病学 | 6871篇 |
神经病学 | 29008篇 |
特种医学 | 11015篇 |
外国民族医学 | 74篇 |
外科学 | 47334篇 |
综合类 | 76649篇 |
现状与发展 | 42篇 |
一般理论 | 29篇 |
预防医学 | 48268篇 |
眼科学 | 8443篇 |
药学 | 46825篇 |
439篇 | |
中国医学 | 36714篇 |
肿瘤学 | 25391篇 |
出版年
2024年 | 1459篇 |
2023年 | 7222篇 |
2022年 | 13714篇 |
2021年 | 18473篇 |
2020年 | 17054篇 |
2019年 | 22694篇 |
2018年 | 20206篇 |
2017年 | 17720篇 |
2016年 | 15922篇 |
2015年 | 15565篇 |
2014年 | 29516篇 |
2013年 | 31964篇 |
2012年 | 28283篇 |
2011年 | 30655篇 |
2010年 | 25011篇 |
2009年 | 23185篇 |
2008年 | 23085篇 |
2007年 | 23484篇 |
2006年 | 20812篇 |
2005年 | 18144篇 |
2004年 | 15046篇 |
2003年 | 13141篇 |
2002年 | 10593篇 |
2001年 | 9440篇 |
2000年 | 7768篇 |
1999年 | 6769篇 |
1998年 | 5690篇 |
1997年 | 5169篇 |
1996年 | 4493篇 |
1995年 | 4281篇 |
1994年 | 3892篇 |
1993年 | 3148篇 |
1992年 | 3039篇 |
1991年 | 2526篇 |
1990年 | 2269篇 |
1989年 | 1981篇 |
1988年 | 1791篇 |
1987年 | 1521篇 |
1985年 | 4353篇 |
1984年 | 5294篇 |
1983年 | 3686篇 |
1982年 | 4214篇 |
1981年 | 3850篇 |
1980年 | 3459篇 |
1979年 | 3142篇 |
1978年 | 2684篇 |
1977年 | 2042篇 |
1976年 | 2288篇 |
1975年 | 1740篇 |
1974年 | 1512篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
目的探讨左半结肠癌急性梗阻Ⅰ期切除吻合的Ⅰ临床应用价值。方法对1988年1月至2006年12月24侧实施左半结肠癌急性梗阻Ⅰ期切除吻合手术患者的资料进行回顾性总结。结果24例均未发生吻合口漏,仅3例发生切口感染,经局部换药处理Ⅱ期愈合。结论积极的术前准备、术中彻底的肠减压能为左半结肠癌急性梗阻Ⅰ期切除吻合提供安全保证. 相似文献
52.
血管内皮生长因子在高原脑水肿形成中作用的实验研究 总被引:4,自引:0,他引:4
目的:探讨血管内皮生长因子(VEGF)在高原脑水肿形成中的作用。方法:建立大鼠模拟高原模型,应用脑干湿重比率法定量脑水肿情况、应用荧光素钠透过率测定BBB通透性、应用实时荧光定量RT-PCR法检测脑组织VEGF mRNA含量以及应用蛋白印迹法半定量脑组织VEGF含量。结果:大鼠在高原24 h后脑组织含水率明显增高(P<0.05),荧光素钠透过率显著增加(P<0.01);VEGF mRNA转录及其表达显著增高(P<0.001)。结论:VEGF表达在高原脑水肿形成中起重要作用。 相似文献
53.
Teng-Yi Huang Hsiao-Wen Chung Fu-Nien Wang Cheng-Wen Ko Cheng-Yu Chen 《Magnetic resonance in medicine》2004,51(2):243-247
In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished. 相似文献
54.
中风毒邪论是一种与传统中医中风病理有所不同的理论 ,在中风毒邪论指导下形成解毒通络方是较为理想的神经保护剂 ,可解决目前神经保护治疗的主要障碍 ,有望成为提高中医治疗中风急性期疗效的关键 相似文献
55.
PROBLEM: Recent developments in providing care to children with emotional and behavioral disorders, especially those with serious emotional disturbance, have included the establishment of systems of care. Guided by a set of principles and values, these systems of care have organized and delivered services to children and families with complex needs. To date, nurses have not had a salient role in systems of care. RESULTS: It is estimated that 20% of American children and adolescents have an emotional or mental disorder. As many as two thirds of these children are not receiving services. Systems of care have been funded to provide services for these children, particularly for the most severely affected. To date, nursing has not had a prominent role in these systems of care. CONCLUSIONS: Based on their knowledge, skills, and holistic approach to care, nurses could better integrate nursing care into systems of care. Possible roles as case managers, primary therapists, in-home interventionists, and in educational programs are suggested. 相似文献
56.
57.
Moussa Ndong Machiko Kazami Tsukasa Suzuki Mariko Uehara Shin-ichi Katsumata Hirohumi Inoue Ken-Ichi Kobayashi Tadahiro Tadokoro Kazuharu Suzuki Yuji Yamamoto 《Nutrition Research》2009,29(9):640-647
Iron deficiency (ID) is one of the most commonly known forms of nutritional deficiencies. Low body iron is thought to induce neurologic defects but may also play a protective role against cancer development by cell growth arrest. Thus, ID may affect cellular pathways controlling cell growth and proliferation, the mechanism of which is still not fully understood. The serine/threonine protein kinase Akt and its downstream target, the mammalian Target of Rapamycin (mTOR), is known to play a crucial role in the regulation of cell growth and survival. Therefore, we hypothesized that Akt/mTOR pathway could be influenced by ID. Three-week-old male Wistar-strain rats were divided into 3 groups and the 2 groups had free access to a control diet (C group) or an iron-deficient diet (D group). The third group (PF group) were pair-fed the control diet to the mean intake of the D group. After 4 weeks, rats were killed and their brains were sampled. In separate experiments, COS-1 cells were cultured with or without the iron chelator deferoxamine. Western blots of brain samples and COS-1 lysates were used to analyze the expression and phosphorylation state of Akt, TSC2, mTOR, and S6 kinase proteins implicated in the Akt/mTOR pathway. Using 2 different ID models, we show for the first time that iron deficiency depresses Akt activity in rats and in COS-1 cells, leading to a decrease in mTOR activity. 相似文献
58.
59.
Robert M. Levy Roman Saikovsky Evgeniya Shmidt Alexander Khokhlov Bruce P. Burnett 《Nutrition Research》2009
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups. 相似文献
60.