全文获取类型
收费全文 | 93182篇 |
免费 | 6936篇 |
国内免费 | 2132篇 |
专业分类
耳鼻咽喉 | 500篇 |
儿科学 | 1855篇 |
妇产科学 | 1123篇 |
基础医学 | 10238篇 |
口腔科学 | 1505篇 |
临床医学 | 11681篇 |
内科学 | 9623篇 |
皮肤病学 | 450篇 |
神经病学 | 12285篇 |
特种医学 | 2371篇 |
外国民族医学 | 2篇 |
外科学 | 6516篇 |
综合类 | 12504篇 |
现状与发展 | 6篇 |
一般理论 | 24篇 |
预防医学 | 16545篇 |
眼科学 | 748篇 |
药学 | 8709篇 |
118篇 | |
中国医学 | 2476篇 |
肿瘤学 | 2971篇 |
出版年
2024年 | 336篇 |
2023年 | 1757篇 |
2022年 | 2784篇 |
2021年 | 4035篇 |
2020年 | 3888篇 |
2019年 | 3369篇 |
2018年 | 3191篇 |
2017年 | 3278篇 |
2016年 | 3373篇 |
2015年 | 3306篇 |
2014年 | 5993篇 |
2013年 | 7450篇 |
2012年 | 5536篇 |
2011年 | 5854篇 |
2010年 | 4630篇 |
2009年 | 4450篇 |
2008年 | 4612篇 |
2007年 | 4347篇 |
2006年 | 3899篇 |
2005年 | 3248篇 |
2004年 | 2701篇 |
2003年 | 2365篇 |
2002年 | 1905篇 |
2001年 | 1615篇 |
2000年 | 1368篇 |
1999年 | 1158篇 |
1998年 | 1134篇 |
1997年 | 1089篇 |
1996年 | 883篇 |
1995年 | 837篇 |
1994年 | 804篇 |
1993年 | 716篇 |
1992年 | 651篇 |
1991年 | 619篇 |
1990年 | 505篇 |
1989年 | 471篇 |
1988年 | 461篇 |
1987年 | 437篇 |
1986年 | 408篇 |
1985年 | 521篇 |
1984年 | 432篇 |
1983年 | 272篇 |
1982年 | 295篇 |
1981年 | 258篇 |
1980年 | 251篇 |
1979年 | 168篇 |
1978年 | 143篇 |
1977年 | 130篇 |
1976年 | 98篇 |
1974年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
HEINER LANGENFELD AXEL KREIN MICHAEL KIRSTEIN LUDWIG BINNER† EUROPEAN PEA CLINICAL INVESTIGATION GROUP 《Pacing and clinical electrophysiology : PACE》1998,21(11):2187-2191
The peak endocardial acceleration (PEA, unit g) shows a near correlation with myocardial contractility during the isometric systolic contraction of the heart (dP/dtmax), with sympathetic activity and, thus, with physiological heart rate modulation. The (Biomechanical Endocardial Sorin Transducer (BEST) sensor is incorporated in the tip of a pacing lead and measures PEA directly near the myocardium. In an international study, the lead was implanted with the dual chamber pacemaker Living-1 (Sorin) in 105 patients. The behavior of the PEA signal was tested under conditions of physical and mental stress and during daily life activities by 24-hour recordings of PEA (PEA Holter) at 1 to 2 months and approximately 1 year after implantation. Implantation of the BEST lead was performed without complications in all patients. The sensor functioned properly in the short- and long-term in 98% of patients. Although PEA values differed from patient to patient, the values closely reflected the variations in sympathetic activity due to physical and mental stress in each patient. During exercise and during daily life activities a close correlation between PEA and heart rate was observed among patients with normal sinus rhythm. Peak endocardial acceleration allows a nearly physiological control of the pacing rate. 相似文献
72.
Such research evidence as exists on effective drug strategies in prevention and education draws attention to the importance of involving parents along with other community agencies and school governors. Much depends nevertheless on the way in which 'involvement' is interpreted and the assumptions that are made about parents' knowledge of drugs and drug education as well as their attitudes to drug issues. As the age of initial experimentation and contact with drugs continues to fall, the importance of enskilling parents to support drug education programmes for 5 year olds and upwards continues to rise. This paper reports the first wide ranging survey of parents' knowledge of drugs and drug issues across an entire English county embracing younger as well as older children. The need for more coordinated, informed and systematic guidance to parents is established. 相似文献
73.
复方18甲基炔诺酮/雌二醇透皮控释传递系统(LNG/E_2 TCDS)能同时恒速释放低剂量的LNG和E_2,在1周内维持一个平稳而有效的LNG血药浓度。药动学与药效学研究证明,该系统释放的LNG能达到血清LNG目标水平,产生有效的排卵抑制(6/6)。LNG/E_2 TCDS可望发展成为一种安全、有效、非侵入性的新型生育调节避孕制剂。 相似文献
74.
The disector, an unbiased stereological method for evaluation of synaptic densities, was used to analyse putative GABA and glutamate innervations of the supraoptic nucleus of virgin and lactating rats. The analysis was performed on ultrathin sections labelled for either of the amino acids with a postembedding immunogold technique. Our observations showed that the volume of the nucleus increased by 40% in lactating animals, an increase due to a significant enlargment of dendritic and somatic, but not vascular, volumes. Nevertheless, values of overall synaptic densities in the whole nucleus remained as high as those in virgin rats (37–40×106 synapses/mm3). About 45% of all synapses were immunoreactive for GABA and 25% for glutamate; there were twice as many GABA- and glutamate-positive synapses on dendrites as on somata. When we estimated synaptic densities in relation to the neuropil (by subtracting the proportion of sampled areas occupied by somatic profiles), we found a significant increase in synaptic density in lactating animals. This affected axodendritic as well as axosomatic synapses, immunopositive and immunonegative for GABA or glutamate. The disector also allowed us to determine that the number of synapses from terminals making contacts on several somata and/or dendrites simultaneously constituted about 9% of all synapses in virgin rats, a proportion which more than doubled in lactating rats. About 50% were immunopositive for GABA and 30% for glutamate.
Our data offer further evidence of physiologically-linked structural synaptic plasticity in the supraoptic nucleus and clearly demonstrate that it affects both inhibitory and excitatory inputs on dendrites, as well as on somata, throughout the nucleus. 相似文献
75.
Marek Motyka PhD Helena Motyka MA RN Romana Wsoek MA RN 《Journal of advanced nursing》1997,26(5):909-912
The paper presents the results of a pilot study which involved 50 nurses from several departments of internal medicine of The State Clinical Hospital of the Collegium Medicum, Jagiellonian University in Cracow. The results are based on the Statement Response Questionnaire. They show that the most common responses of the nurses in the face of anxiety expressed by patients are cheering up the patient, collecting information about the symptom, and offering explanation of the symptom. The least common responses included expressing one's own positive emotions and showing empathy towards the patient. 相似文献
76.
77.
78.
Ingrid Gouldsborough Nick Ashton 《Clinical and experimental pharmacology & physiology》1998,25(12):1024-1031
1. The aim of the present study was to compare electrolyte handling in naturally reared neonatal spontaneously hypertensive rats (SHR) with those reared by a Wistar-Kyoto (WKY) rat foster mother (denoted SHRX), as cross-fostering SHR pups to a WKY rat dam lowers adult blood pressure in the SHR. 2. The electrolyte content of WKY rat and SHR dams’ milk was determined and electrolyte intake and urinary excretion rates were calculated in both naturally reared and cross-fostered WKY rat and SHR pups. 3. The milk sodium concentration fell in both strains (WKY rat: 31.8 ± 2.0 to 15.2 ± 1.2 mmol/L; SHR 31.9 ± 2.5 to 18.2 ± 1.6 mmol/L; P < 0.001), as did potassium (P < 0.001), over lactation, but there were no differences between strains. Calcium and magnesium concentrations increased (P< 0.001), although SHR dam's milk contained less calcium (P < 0.001) than that of WKY rat dams during the third week of lactation. 4. Spontaneously hypertensive rat pups ingested less milk (P<0.05) than WKY rat pups; therefore, their cumulative sodium intake over postnatal days 4–15 was significantly lower than that of WKY rat pups (WKY rat vs SHR: 84.4 ± 3.6 vs 59.7 ± 2.6 μmol/g bodyweight, respectively; P < 0.05) and fostered SHRX pups (77.7 ± 7.0 μmol/g bodyweight; P < 0.05). Potassium and magnesium intakes were comparable between SHR, WKY rat and SHRX pups, but SHR pups ingested significantly less calcium than either WKY rat pups (136.1 ± 6.4 vs 200.1 ± 9.5p, mol/g bodyweight, respectively; P<0.05) or SHRX pups (200.0 ± 18.0 μmol/g bodyweight; P<0.05). 5. These data show that the neonatal SHR experiences a period of sodium deficiency during the developmental stage when cross-fostering is effective in lowering blood pressure. This is consistent with the reported up-regulation of the renin-angiotensin system observed in SHR at this time and may have a long-term influence on blood pressure. 相似文献
79.
Donna M. Ballantine Shelley A. Klemm Terry J. Tunny Michael Stowasser Richard D. Gordon 《Clinical and experimental pharmacology & physiology》1994,21(3):215-218
1. Aldosterone levels in patients with unilateral aldosterone-producing adenomas may be responsive or unresponsive to the renin-angiotensin system, with the former often previously misdiagnosed as bilateral adrenal hyperplasia. 2. In tumours from patients in the responsive subgroup, renin mRNA is expressed in greater amounts than in tumours from patients in the unresponsive subgroup, or in normal adrenals. 3. We compared the frequency of four renin gene polymorphisms in peripheral blood DNA from the two subgroups and found significant associations between BglI, TaqI and HinfI restriction fragment length polymorphisms (RFLP) and aldosterone responsiveness. 4. Allelic variation in the constitutive renin gene was associated with a specific cause of hypertension. 相似文献
80.