全文获取类型
收费全文 | 166925篇 |
免费 | 17579篇 |
国内免费 | 10080篇 |
专业分类
耳鼻咽喉 | 1490篇 |
儿科学 | 2475篇 |
妇产科学 | 1961篇 |
基础医学 | 14788篇 |
口腔科学 | 3507篇 |
临床医学 | 21691篇 |
内科学 | 21311篇 |
皮肤病学 | 2029篇 |
神经病学 | 6786篇 |
特种医学 | 6452篇 |
外国民族医学 | 33篇 |
外科学 | 15232篇 |
综合类 | 34440篇 |
现状与发展 | 27篇 |
一般理论 | 12篇 |
预防医学 | 17170篇 |
眼科学 | 3157篇 |
药学 | 17778篇 |
204篇 | |
中国医学 | 12759篇 |
肿瘤学 | 11282篇 |
出版年
2024年 | 814篇 |
2023年 | 2703篇 |
2022年 | 5962篇 |
2021年 | 7606篇 |
2020年 | 6335篇 |
2019年 | 4395篇 |
2018年 | 5022篇 |
2017年 | 5289篇 |
2016年 | 4636篇 |
2015年 | 7396篇 |
2014年 | 9093篇 |
2013年 | 10200篇 |
2012年 | 13693篇 |
2011年 | 14335篇 |
2010年 | 11455篇 |
2009年 | 9920篇 |
2008年 | 10771篇 |
2007年 | 10359篇 |
2006年 | 9221篇 |
2005年 | 7990篇 |
2004年 | 5702篇 |
2003年 | 4913篇 |
2002年 | 4191篇 |
2001年 | 3657篇 |
2000年 | 3124篇 |
1999年 | 2603篇 |
1998年 | 1682篇 |
1997年 | 1671篇 |
1996年 | 1387篇 |
1995年 | 1286篇 |
1994年 | 1039篇 |
1993年 | 733篇 |
1992年 | 724篇 |
1991年 | 643篇 |
1990年 | 558篇 |
1989年 | 529篇 |
1988年 | 430篇 |
1987年 | 422篇 |
1986年 | 355篇 |
1985年 | 287篇 |
1984年 | 206篇 |
1983年 | 168篇 |
1982年 | 130篇 |
1981年 | 117篇 |
1980年 | 79篇 |
1979年 | 74篇 |
1978年 | 49篇 |
1977年 | 56篇 |
1976年 | 53篇 |
1966年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
We report on a 44-year-old woman with a right frontal meningioma, who presented with resting tremor, rigidity and bradykinesia in the left limbs. There were no other neurologic manifestations. A computed tomography scan demonstrated a huge high-density mass in the right frontal lobe and marked surrounding edema causing compression of the basal ganglia. Cerebral angiography showed a typical sunburst tumor stain and three feeding vessels from the bilateral middle meningeal arteries and the right callosomarginal artery. The pathologic diagnosis was transitional type meningioma. Before surgery, treatment with levodopa and bromocriptine was significantly effective in controlling hemiparkinsonism, which completely disappeared after surgical removal of the tumor. This outcome supports the notion that local compression due to edema may cause a functional disorder in the basal ganglia producing reversible contralateral parkinsonism. 相似文献
103.
The nursing staff on an acute medical hospital ward elected to wear their own clothes to work for a period of 2 months. The trial was evaluated using a variety of research methods and it raised a number of issues about the role of uniform, about patients' perceptions of nurses and nurses' perceptions of their role. The study has led to questions being raised about the assumptions that are made if uniform is worn and the appropriateness of a uniform dress. 相似文献
104.
Shuei-Tu Chen Ko-Hsiu Lu Hai-Lun Sun Wen-Tung Chang Ko-Huang Lue Ming-Chih Chou 《Pediatric allergy and immunology》2006,17(1):49-54
Leukotriene receptor antagonists (LTRAs) were recently added to the method of treating allergic rhinitis (AR). However, in children under 6 yr old, there has been no study about its efficacy in treating AR. We aim to compare the clinical efficacy of montelukast, cetirizine and placebo in the treatment of children from 2 to 6 yr old with perennial allergic rhinitis (PAR), to see if there are any significant differences. Sixty children were selected and treated with montelukast, or cetirizine, or placebo once daily. The efficacy of the three agents was compared with the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and Total Symptom Score (TSS) by diary. In addition, we also examined serum IgE, serum eosinophil cationic protein (ECP), blood eosinophil counts, nasal airway resistance (NAR) and eosinophil percentage in nasal smears. The results revealed that both montelukast and cetirizine were significantly efficacious compared with placebo in NAR, eosinophil percentage in nasal smears, PRQLQ, TSS and all symptom items except nasal itching, throat itching and tearing. For nasal itching, only cetirizine was significantly efficacious. On the other hand, for night sleep quality, montelukast was significantly superior to cetirizine. 相似文献
105.
目的:分析74例更换起搏器时电极导线的各项参数的变化并探讨导线更换指标。方法:本组年龄12~87(62.8±18.4)岁,其中病窦综合征45例,房室传导阻滞29例,均为单腔VVI起搏。结果:至测量时原心室起搏电极导线的埋置时间60~148(97.4±22.8)月,首次埋置时起搏阈值为(0.48±0.24)V,更换时为(1.29±0.64)V(P(0.01),增加0.81V,增幅为168%,首次植入时R波幅为(7.8±3.6)mV,更换时为(5.9±3.4)mV(P(0.05)。植入时电极导线阻抗为(664±122)Ω,更换时阻抗为(726±148)Ω,增幅9.3%(P(0.05)。7例因起搏阈值大于2.0 V或阻抗大于1 250Ω而重新植入电极导线。原电极导线使用率为90.5%。结论:埋置起搏电极导线8~9年后,90.5%原电极导线仍在可使用的范围内,能否支持到再次更换需进一步随访。 相似文献
106.
We compared the aniseikonia, Seidel aberrations, spot diagrams, and peripheral refractive power errors of a schematic eye with a super-reversed intraocular lens (IOL) and with conventional IOLs. The results did not indicate that the super-reversed IOL performs better optically than the other IOLs, primarily because of its poorer on-axis image performance. However, this disadvantage can be overcome by aspherizing the super-reversed IOL. 相似文献
107.
108.
过去,为了保证前段的血液供应,外直肌全麻痹的手术治疗要分2~3次完成,考虑到全麻痹的外直肌已无功能,我们提出在这种条件下可以不动含睫状前动脉的外直肌,只退后内直肌和将上,下直肌的外侧1/2移到外直肌的附着处,如此安排,可以一次手术完成治疗,这样可以缩短治疗时间,减少病人的痛苦和负担,我们治疗了7例8眼,结果比较满意。 相似文献
109.
Dr James Charles Robin Turner MA PhD ScD 《Journal of clinical monitoring and computing》1991,7(3):237-240
Anesthetic gases from several patients can be monitored simultaneously with a centrally located mass spectrometer. Such monitoring requires catheters from patient to spectrometer that are several meters long. Scamman (J Clin Monit 1988;4:227–229) found that when the respiratory frequency is high, as with infants, the CO2 signal from the patient is unacceptably distorted during passage down the catheter. This is due to Taylor dispersion of the input signal. An outline of the theory of Taylor dispersion is given. The equations describe the interaction between the velocity distribution (which, in laminar flow, is parabolic) and the radial diffusion of CO2. This interaction keeps a tracer signal together in a pulse, as it moves down the tube with themean velocity, spreading somewhat as it proceeds. How much does an initially sharp signal become blurred? The spread of such a signal when it reaches the detector, measured in time, can be expressed in various ways. Measurement is complicated, however, by the fact that the gas pressure may fall by as much as a factor of 10 along the line. The resultant expansion and acceleration of the gas cannot be ignored. A full treatment of this complication is given elsewhere, but the following simple equation is described: {ie237-1} Typically, the spread time is up to a quarter of a second for catheters of 50 m, such as used by Scamman. This is comparable with the period of CO2 rise and fall for infants and explains the serious distortion in wave form that Scamman found. Some distortion can be eliminated by reducing R to 0.1 or less, but the extent of this improvement is small. Ideally, for fast-breathing patients, the catheter length should be reduced to 20 m or less, if possible. 相似文献
110.
Summary To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transeatheter laser and electrical
energy on ventricle, 33 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter
laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical
ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization
and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion
dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature
beats and 86 % of them occurred within the first minute after energy discharged, while ventricular tachycardias were found
in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5 % and 13
% respectively (P< 0.01): 4) A decrease in aortic blood pressure and an increase in central verous pressure induced by laser ablation were
significantly less than that produced by the same amount of electrical energy (P<0.0l). Our preliminary results have shown that transeatheter laser ablation has great potential for becoming a practical
method in the management of refractory tachycardias. 相似文献