全文获取类型
收费全文 | 109766篇 |
免费 | 7953篇 |
国内免费 | 5962篇 |
专业分类
耳鼻咽喉 | 350篇 |
儿科学 | 2079篇 |
妇产科学 | 690篇 |
基础医学 | 7382篇 |
口腔科学 | 724篇 |
临床医学 | 16346篇 |
内科学 | 9804篇 |
皮肤病学 | 315篇 |
神经病学 | 17009篇 |
特种医学 | 6325篇 |
外国民族医学 | 3篇 |
外科学 | 16016篇 |
综合类 | 22389篇 |
现状与发展 | 6篇 |
一般理论 | 1篇 |
预防医学 | 5104篇 |
眼科学 | 1308篇 |
药学 | 10477篇 |
104篇 | |
中国医学 | 6490篇 |
肿瘤学 | 759篇 |
出版年
2024年 | 403篇 |
2023年 | 1731篇 |
2022年 | 3271篇 |
2021年 | 4619篇 |
2020年 | 4242篇 |
2019年 | 3459篇 |
2018年 | 3500篇 |
2017年 | 3980篇 |
2016年 | 4199篇 |
2015年 | 4019篇 |
2014年 | 7249篇 |
2013年 | 7921篇 |
2012年 | 6823篇 |
2011年 | 7310篇 |
2010年 | 6174篇 |
2009年 | 5677篇 |
2008年 | 5712篇 |
2007年 | 5703篇 |
2006年 | 5402篇 |
2005年 | 4744篇 |
2004年 | 3844篇 |
2003年 | 3536篇 |
2002年 | 2987篇 |
2001年 | 2583篇 |
2000年 | 2219篇 |
1999年 | 1831篇 |
1998年 | 1529篇 |
1997年 | 1393篇 |
1996年 | 1122篇 |
1995年 | 956篇 |
1994年 | 792篇 |
1993年 | 606篇 |
1992年 | 530篇 |
1991年 | 460篇 |
1990年 | 395篇 |
1989年 | 363篇 |
1988年 | 289篇 |
1987年 | 263篇 |
1986年 | 244篇 |
1985年 | 316篇 |
1984年 | 244篇 |
1983年 | 162篇 |
1982年 | 193篇 |
1981年 | 207篇 |
1980年 | 147篇 |
1979年 | 97篇 |
1978年 | 61篇 |
1977年 | 51篇 |
1976年 | 47篇 |
1975年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
中风后癫痫的临床研究 总被引:5,自引:0,他引:5
本文报告36例中风后癫痫发作的临床和CT资料。通过回顾性病历复习和随访发现,中风后癫痫的发生率占同期住院中风患者的5.26%,以蛛网膜下腔出血和脑栓塞发生癫痫比率最高,分别为15%和12.5%。癫痫发作与CT所见病灶分布密切相关,皮质病灶较皮质下病灶更易发生病病。癫痫发作可发生于中风后任何时期,但早期癫痫以出血性中风多见,而迟发性癫痫则更多见于脑梗塞患者。 相似文献
102.
F. Strik 《Documenta ophthalmologica. Advances in ophthalmology》1988,69(1):51-71
For an adequate assessment of both the ophthalmological and the neurological consequences of carotid obstruction measurement of the blood pressure in the carotid flow area is essential.To this end there are two objective, registrating methods available at the moment: OPG-Gee and OODG-Ulrich. A comparative study was made into the basic principles, calibration curves and application methods of these systems. By both methods the systolic retinal - and ciliary - as well as the diastolic ocular blood pressure can be measured. OODG is more exact for the differentiation and measurement of the two systolic blood pressures. OPG-Gee, however, offers the unique additional possibility of a judgement on the systolic blood pressure in the carotid siphon without, however, taking into acount a (difference in) pre-existing intraocular pressure. Our own investigation shows that in order to obtain a correct assessment of the carotico-brachial relation both blood pressures should be measured simultaneously. The results of the graphic analysis of the curves are compared to those by Ulrich. For the diagnosis of carotid obstructions this analysis of the shape had no advantages over the determination of the pressure values.Finally, a survey is given of possible applications of OPG and OODG in various other syndromes. 相似文献
103.
M. Dujovny K. V. Slavin M. S. Luer G. Hernandez-Avila J. I. Ausman 《Acta neurochirurgica》1995,133(1-2):83-86
Summary Different methods have been used in the evaluation and monitoring of the cerebral oxygen supply during neuro-interventional therapies. Attenuation of near-infrared light by the chromophores oxyhemoglobin and deoxyhemoglobin have shown to be useful in the study of the cellular oxygen metabolism and oxygen delivery to the brain. Transcranial cerebral oximetry (TCCO) has the advantage of providing real-time information regarding regional brain oxygen saturation (rSO2) by using wavelengths in the near-infrared range.We present a patient with a carotid cavernous fistula who underwent balloon occulusion and concurrent continuous TCCO monitoring. TCCO was found to be a useful tool providing immediate rSO2 values during the angiographic and interventional procedures. Initial balloon occlusion of a carotid cavernous fistula resulted in partial occlusion of the internal carotid artery lumen causing an immediate decrease in rSO2 which correlated with angiographic findings. Subsequent reocclusion of the fistula produced a slower and smaller degree of decrease in rSO2 with clinical improvement in the patient. Changes in rSO2 were detected before any adverse clinical event was observed. TCCO was reliable, safe, sensitive, and provided a real-time assessment tool for the monitoring of brain oxygen supply in a patient undergoing a neuroendovascular procedure. 相似文献
104.
Toshiaki Nakashima Fuminori Goda Jinge Jiang Toshihide Shima Harold M. Swartz 《Magnetic resonance in medicine》1995,34(6):888-892
The partial pressure of oxygen (pO2) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO2 below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO2 measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO2 decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI4)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI4-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI4-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO2 of the liver in vivo and that the pO2 in the Kupffer cells is decreased when the liver is damaged by CCI4. 相似文献
105.
Minor,moderate and severe head injury 总被引:9,自引:0,他引:9
Summary The future role of the neurosurgeon in the management of head injury is reviewed in terms of the care of patients with minor, moderate and severe head injuries. In minor head injury it is predicted that there will be increasing pressure on the neurosurgeon to undertake the management and follow-up of all patients who have sustained head injury, and this will place a considerable additional load on each neurosurgical unit. This is based on a survey of 1919 head injuries admitted in one calendar year (1981), consisting of 93 severe injuries (GCS < 8), 210 moderate injuries (GCS 8–12), and 1616 minor injuries (GCS 13/14). In moderate injuries CT will assume a major role in detecting hematoma early and identifying contusions. There may yet be a role for steroids in these cases and there should be a greater use of neurorehabilitation, instead of the current overemphasis on the severely injured. In severe injury future efforts will be to prevent early secondary insults and to find better methods of controlling raised intracranial pressure. 相似文献
106.
Gary W Thickbroom Michelle L Byrnes Rick Stell Frank L Mastaglia 《Movement disorders》2003,18(4):395-402
Previous work has suggested that there may be a widespread disturbance of motor control mechanisms in patients with cervical dystonia. In the present study, we used transcranial magnetic stimulation to investigate the topography of the corticomotor projection to the abductor pollicis brevis (APB) muscle in 10 subjects with idiopathic torticollis. Threshold-adjusted stimuli were delivered at multiple scalp sites during a low-level voluntary contraction of the APB, and maps were generated of motor evoked potential amplitude versus scalp site. The cortical maps for the APB on the side opposite to the direction of head rotation were displaced laterally or posteriorly in all subjects and reverted to a more normal position after botulinum toxin injection of the cervical muscles in 5 subjects. The findings point to a reversible reorganisation of the corticomotor representation of the hand on the same side as the sternocleidomastoid (SCM) muscle that is involved in producing the dystonia. These results provide further evidence for the involvement of cortical centres and for a more widespread abnormality of motor control mechanisms in focal dystonia. The findings also support the notion that head turning is chiefly mediated by the hemisphere ipsilateral to the direction of the head rotation by means of a corticomotor projection to the contralateral SCM. 相似文献
107.
Emergency airway management in patients with cervical spine injuries 总被引:10,自引:0,他引:10
108.
Summary This study evaluates local variations of the cerebral vasomotor responses to hypercapnia and haemorrhagic hypotension in a pig model. Four laser Doppler flow probes were used in each pig. There was considerable variation in laser Doppler signals between the four probes in baseline recordings. The increases in flow after CO2 administration in 7 pigs had a mean coefficient of variation of 0.43 ± 0.31, and the flow changes after blood loss in another 7 pigs had a mean coefficient of variation of 0.45 ± 0.34. The range of flow changes within each animal was large; the probe with the highest CO2 response showed on the average a 273% ± 157% larger CO2 response than the probe with the lowest CO2 response. Correspondingly, the probe with the best preserved blood flow after blood loss had on the average a flow value of 93% ± 12% of the baseline value, while the probe that changed most with haemorrhage had a flow value of 44% ± 24% of the baseline value. Single laser Doppler recordings have been used for the monitoring of cerebral blood flow in neurosurgical critical care, but our results suggest that a single laser Doppler flow probe is not an adequate method to monitor vasoreactivity in neurosurgical patients because flow signals from one probe may be unrepresentative for other sites in the brain. 相似文献
109.
缺血性脑血管病与颈动脉粥样硬化及其危险因素的关系 总被引:17,自引:0,他引:17
目的探讨缺血性脑血管病(ICVD)与颈动脉粥样硬化及其危险因素的关系。方法对186例ICVD患者与194例非脑血管病患者和正常体检者(对照组)行颈部血管超声检查和血液生化检查;比较两组间的颈动脉硬化程度及脑卒中危险因素的差异。结果ICVD组年龄[(69±7)岁]和患有高血压(66.1%)、糖尿病(53.4%)、代谢综合征患者(44.6%)的比率非常明显高于对照组[(61±5)岁、48.8%、15.2%、12.9%](均P<0.001)。ICVD组颈动脉粥样硬化分级计分≥2分(斑块发生率)、≥3分(血管狭窄发生率)分别为69.3%、20.4%,明显高于对照组的33.5%和5.1%(均P<0.05)。结论颈动脉粥样硬化是ICVD的危险因素之一;各种危险因素的聚集对ICVD的发生起重要作用。 相似文献
110.