全文获取类型
收费全文 | 10835篇 |
免费 | 595篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 226篇 |
妇产科学 | 245篇 |
基础医学 | 1362篇 |
口腔科学 | 147篇 |
临床医学 | 998篇 |
内科学 | 2760篇 |
皮肤病学 | 159篇 |
神经病学 | 1056篇 |
特种医学 | 573篇 |
外科学 | 1615篇 |
综合类 | 32篇 |
一般理论 | 13篇 |
预防医学 | 722篇 |
眼科学 | 129篇 |
药学 | 644篇 |
中国医学 | 11篇 |
肿瘤学 | 694篇 |
出版年
2023年 | 52篇 |
2022年 | 86篇 |
2021年 | 219篇 |
2020年 | 147篇 |
2019年 | 214篇 |
2018年 | 257篇 |
2017年 | 215篇 |
2016年 | 246篇 |
2015年 | 275篇 |
2014年 | 393篇 |
2013年 | 554篇 |
2012年 | 844篇 |
2011年 | 959篇 |
2010年 | 535篇 |
2009年 | 477篇 |
2008年 | 768篇 |
2007年 | 796篇 |
2006年 | 646篇 |
2005年 | 752篇 |
2004年 | 639篇 |
2003年 | 559篇 |
2002年 | 510篇 |
2001年 | 100篇 |
2000年 | 59篇 |
1999年 | 77篇 |
1998年 | 110篇 |
1997年 | 116篇 |
1996年 | 99篇 |
1995年 | 88篇 |
1994年 | 83篇 |
1993年 | 68篇 |
1992年 | 43篇 |
1991年 | 40篇 |
1990年 | 44篇 |
1989年 | 35篇 |
1988年 | 32篇 |
1987年 | 27篇 |
1986年 | 37篇 |
1985年 | 37篇 |
1984年 | 26篇 |
1983年 | 27篇 |
1982年 | 34篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1975年 | 9篇 |
1974年 | 11篇 |
1972年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Robert J Derksen Fred C Bakker Emil A Heilbron Pieter C Geervliet Irma M Spaans Elly S M de Lange-de Klerk Bart Veenings Peter Patka Henk J Th M Haarman 《European journal of emergency medicine》2006,13(1):3-8
OBJECTIVES: In the quest for a cost-effective and quality-preserving solution to manage crowding in the emergency department, the possibility of deploying regular emergency nurses for the treatment of acute ankle injuries was investigated. The aim of this study is to compare the diagnostic accuracy of emergency nurses with that of senior house officers in interpreting ankle and foot radiographs. METHODS: A prospective study comparing the assessment of 60 radiographs (30 feet and 30 ankles) by 16 emergency nurses before and after an educational session was performed. Each subset of 30 radiographs contained 12 fractures, hand-picked by a radiologist to represent everyday traumatology in the emergency department. The control group consisted of eight senior house officers representing everyday expertise. The outcome of the diagnostic assessment, represented as the pooled sensitivity and specificity for both groups, was compared using Z-statistics. RESULTS: Before the training session, the specialized emergency nurse group showed a sensitivity of 0.87 (confidence interval 0.83-0.91) compared with 0.93 (confidence interval 0.88-0.96) for the control group (P = 0.05). The specificity of specialized emergency nurses was 0.87 (confidence interval 0.81-0.92) compared with 0.93 (confidence interval 0.89-0.95) for the senior house officers (P < 0.05). After the training session, specialized emergency nurse diagnostic parameters did not differ significantly from the control group, displaying a sensitivity of 0.89 (confidence interval 0.86-0.92) and specificity of 0.92 (confidence interval 0.87-0.95). CONCLUSION: Before the training session, the specialized emergency nurse group showed a significantly lower accuracy than the SHO group. After training, however, the diagnostic accuracy did not differ significantly between groups. Therefore, we conclude that emergency nurses are able to accurately interpret foot and ankle radiographs after a short educational session. 相似文献
2.
Jan Willem R. Pott Kwok H. Wong 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(10):1357-1359
Background Leber’s hereditary optic neuropathy (LHON) is a maternally inherited optic neuropathy caused by mutations in mitochondrial DNA (mtDNA). It is also believed that several epigenetic factors have an influence on the development of LHON.Methods A case series was observed.Results Three patients who developed bilateral optic neuropathy are presented. All patients had a primary LHON mutation in their mtDNA, but also a subnormal vitamin B12 serum level at the time of presentation.Conclusions The clinical picture of optic neuropathy associated with vitamin B12 deficiency shows similarity to that of LHON. Both involve the nerve fibres of the papillomacular bundle. The present case reports suggest that optic neuropathy in patients carrying a primary LHON mtDNA mutation may be precipitated by vitamin B12 deficiency. Therefore, known carriers should take care to have an adequate dietary intake of vitamin B12 and malabsorption syndromes like those occurring in familial pernicious anaemia or after gastric surgery should be excluded. 相似文献
3.
Therapeutic Consequences of Variation in Intraarterial Pressure Measurements After Iliac Angioplasty
Eric Tetteroo Cees Haaring Andries D. van Engelen Yolanda van der Graaf Willem P.T.M. Mali 《Cardiovascular and interventional radiology》1997,20(6):426-430
Purpose: To assess the accuracy of intraarterial measurement of transstenotic pressure gradients for the detection of hemodynamically
suboptimal iliac angioplasty.
Methods: In 14 patients, referred for diagnostic angiography, mean pressure gradients in the aorta and iliac artery were obtained
twice, using a double-sensor pressure catheter. Additional iliac measurements were performed during pharmacologically induced
flow augmentation. Repeatability was assessed by calculation of the mean difference plus standard deviation (MD ± SD) and
repeatability coefficient (2 × SD). These results were extrapolated to 137 iliac angioplasty procedures with secondary stenting
where there was a residual pressure gradient > 10 mmHg.
Results: MD ± SD for repeated measurements at rest and during flow augmentation were 0 ± 2 mmHg and 1 ± 3 mmHg, respectively. Repeatability
coefficients were 3 and 6 mmHg. Mean pressure gradients after hemodynamically insufficient angioplasty were 8 ± 7 mmHg at
rest and 17 ± 5 mmHg following vasodilatation. Inaccurate pressure recordings may have led to inappropriate stent placement
in less than 2.5%, and inappropriate denial of stent placement in less than 5% of the lesions.
Conclusion: Variability of intraarterial pressure measurements has little consequence in the detection of hemodynamically significant
stenosis after angioplasty.
Received: 0/00/00/Accepted: 0/00/00 相似文献
4.
C Niek van Dijk Ben Willem J. Mol Liesbeth S. L. Lim Rene K. Marti Patrick M. M. Bossuyt 《Acta orthopaedica》1996,67(6):566-570
We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on. 122 of these patients had ligament ruptures.
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
5.
6.
7.
Pieter M. Groenendijk August A. B. Lycklama Nijeholt Theo J. Ouwerkerk Ubi van den Hombergh 《Neuromodulation》2007,10(4):363-368
Objective. We studied long‐term clinical efficacy of sacral neuromodulation (SNM) therapy in patients with refractory urgency incontinence (UI), urgency/frequency (UF) and voiding difficulty (VD), together with urodynamic data at baseline and six months postimplant. Materials and Methods. Twenty‐two patients were implanted with a neurostimulator after a positive response to a percutaneous nerve evaluation test defined as a greater than 50% improvement in symptoms. Results. At five‐year follow‐up, the number of incontinent episodes and pad usage per day decreased significantly in 10 out of 15 UI patients. Two of five UF patients were successfully treated with SNM; the number of daily voids for all UF patients decreased from 25 to 19 and average voided volume increased from 98 to 212 mL. One of the two VD patients was able to void to completion. Mean first sensation of filling at the six‐month urodynamic investigation for the UI and UF patients increased from 78 to 241 mL and 141 to 232 mL, respectively, and the maximum bladder capacity increased from 292 to 352 mL and 223 to 318 mL, respectively. Five of 22 patients underwent device explant and one patient still has an inactive stimulator implanted. Conclusion. SNM is an effective treatment modality that offers sustained clinical benefit in the majority of patients with refractory UI, UF, and VD that do not respond to other, more conservative therapies. 相似文献
8.
A C Da Rosa B Kemp T Paiva F H Lopes da Silva H A Kamphuisen 《Electroencephalography and clinical neurophysiology》1991,78(1):71-79
A model of sleep phasic events such as vertex waves, K complexes, delta waves and sleep spindles is proposed. It consists of feedback loops that are driven by white noise (simulating tonic delta and sigma activity) and by isolated random impulses, simulating vertex waves or K complexes, depending on the background tonic activity. A model-based method for the detection of sleep phasic events was implemented in a personal computer. Its performance was investigated using simulated and real whole-night EEG signals. The method was able to detect K complexes and vertex waves in a reliable way in spite of their variable shapes and in the presence of a variety of background activities. The detector appears to have superior performance to those so far reported in the literature. The performance of the detector was also compared to that of an electroencephalographer using normal sleep EEG records of 8 h duration from 6 subjects. The performance was satisfactory both in terms of accuracy and reliability. The problem of detecting K complexes in stages 3 and 4 of sleep is discussed. 相似文献
9.
10.
Saskia L.M.A. Beeres MD Katja Zeppenfeld MD Jeroen J. Bax MD Petra Dibbets-Schneider Marcel P.M. Stokkel MD Willem E. Fibbe MD Ernst E. van der Wall MD Douwe E. Atsma MD Martin J. Schalij MD 《Heart rhythm》2007,4(3):257-265
BACKGROUND: Bone marrow cell injection has been introduced to treat patients with ischemic heart disease. However, focal application of bone marrow cells may generate an arrhythmogenic substrate. OBJECTIVES: To assess the electrophysiological and arrhythmogenic effects of intramyocardial bone marrow cell injection in patients with chronic myocardial ischemia. METHODS: Bone marrow was aspirated in 20 patients (65+/-11 years, 19 male) with drug-refractory angina and myocardial ischemia. Electroanatomical mapping (NOGA, Biosense-Webster, Waterloo, Belgium) was performed during mononuclear cell isolation. Areas for cell injection were selected based on the localization of ischemia on SPECT. These areas were mapped in detail to evaluate local bipolar electrogram duration, amplitude and fragmentation. Mononuclear cells were injected in the ischemic area with the NOGA system. SPECT and electroanatomical mapping were repeated at 3 months. Holter monitoring was repeated at 3 and 6 months. RESULTS: SPECT revealed a decrease in the number of segments with ischemia (3.5+/-2.5 vs. 1.1+/-1.0 at 3 months; P<0.01) and an increased left ventricular ejection fraction (44+/-13% vs. 49+/-17% at 3 months; P=0.02). The number of ventricular premature beats remained unchanged (10+/-24x10(2)/24h vs. 8+/-23x10(2)/24h at 3 months (P=NS) and 12+/-30x10(2)/24h at 6 months (P=NS)). At 3 months follow-up, bone marrow cell injection did not prolong electrogram duration (15.9+/-4.6 ms vs. 15.6+/-4.0 ms; P=NS), decrease electrogram amplitude (3.8+/-1.5 mV vs. 3.8+/-1.5 mV; P=NS), or increase fragmentation (2.0+/-0.5 vs. 1.9+/-0.4; P=NS). CONCLUSION: Intramyocardial bone marrow cell injection does not increase the incidence of ventricular arrhythmias and does not alter the electrophysiological properties of the injected myocardium. 相似文献