全文获取类型
收费全文 | 25625篇 |
免费 | 2174篇 |
国内免费 | 1312篇 |
专业分类
耳鼻咽喉 | 134篇 |
儿科学 | 362篇 |
妇产科学 | 332篇 |
基础医学 | 2624篇 |
口腔科学 | 318篇 |
临床医学 | 2597篇 |
内科学 | 4702篇 |
皮肤病学 | 399篇 |
神经病学 | 1588篇 |
特种医学 | 1056篇 |
外国民族医学 | 10篇 |
外科学 | 3004篇 |
综合类 | 4899篇 |
现状与发展 | 6篇 |
预防医学 | 546篇 |
眼科学 | 1247篇 |
药学 | 2662篇 |
10篇 | |
中国医学 | 1361篇 |
肿瘤学 | 1254篇 |
出版年
2024年 | 85篇 |
2023年 | 390篇 |
2022年 | 621篇 |
2021年 | 877篇 |
2020年 | 884篇 |
2019年 | 816篇 |
2018年 | 794篇 |
2017年 | 779篇 |
2016年 | 863篇 |
2015年 | 946篇 |
2014年 | 1554篇 |
2013年 | 1818篇 |
2012年 | 1453篇 |
2011年 | 1573篇 |
2010年 | 1417篇 |
2009年 | 1340篇 |
2008年 | 1409篇 |
2007年 | 1423篇 |
2006年 | 1390篇 |
2005年 | 1268篇 |
2004年 | 1075篇 |
2003年 | 936篇 |
2002年 | 826篇 |
2001年 | 659篇 |
2000年 | 596篇 |
1999年 | 441篇 |
1998年 | 366篇 |
1997年 | 309篇 |
1996年 | 288篇 |
1995年 | 267篇 |
1994年 | 203篇 |
1993年 | 168篇 |
1992年 | 161篇 |
1991年 | 162篇 |
1990年 | 104篇 |
1989年 | 96篇 |
1988年 | 90篇 |
1987年 | 93篇 |
1986年 | 70篇 |
1985年 | 90篇 |
1984年 | 69篇 |
1983年 | 44篇 |
1982年 | 51篇 |
1981年 | 72篇 |
1980年 | 36篇 |
1979年 | 37篇 |
1978年 | 30篇 |
1977年 | 21篇 |
1976年 | 15篇 |
1975年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Clinical characteristics of rapidly progressive leuko-araiosis 总被引:1,自引:0,他引:1
S. Tarvonen-Schröder I. Räihä T. Kurki T. Rajala L. Sourander 《Acta neurologica Scandinavica》1995,91(5):399-404
Introduction – 38 patients found to have either pure leuko-araiosis (LA) or LA combined with infarction(s) on computer tomography (CT) in 1989 were re-examined in 1992 in order to evaluate the progression of LA. The follow-up period averaged 3.2 years. Material and methods - The clinical and radiological data on patients in 1989 were collected from hospital records and re-evaluated. The patients were re-examined clinically (including 24 hour ambulatory blood pressure measurement), and neuroradiologically (CT) in 1992 for this study. Results – 11 (29%) patients were found to have significant (rapid) progression of the extent of LA on CT during the follow-up. At baseline, there was no significant difference in the mean number of brain infarctions between the groups with progressing (prLA) and non-progressing LA (nprLA) or between the number of cortical and central infarctions within these groups. At follow-up, the total number of infarctions had increased significantly in both groups, but it was mostly because of the increase in cortical infarctions in the prLA group (p = 0.043) and, conversely, the central ones in the nprLA group (p = 0.011). prLA was found to be related to heart failure (82% vs 37%, p = 0.029) and atrial fibrillation (55% vs 19%, p = 0.047), whereas nprLA was strongly associated with a sudden onset of symptoms (78% vs prLA 18%, p = 0.001) like a-true brain infarction. Other clinical factors, including mean blood pressure and heart rate, did not clearly differentiate between the groups. Conclusion - The results suggest that there are different subgroups of patients with LA associated with various vascular factors. The occurrence of LA is not related to the distribution of infarctions. The progression of LA is not related to the number of brain infarctions or to the simultaneous increase of infarctions on CT. 相似文献
72.
Magnetic resonance imaging (MRI) has greatly facilitated morphologic evaluation of spinal cord lesions. Eleven cases representative of inflammatory, demyelinating, neoplastic and vascular diseases, are presented which illustrate and summarize important abnormal features in spinal cord imaging, particularly MR findings. Recently, specialised techniques such as MR angiography, fat-inhibiting methods, dynamic MRI and functional imaging have been developed. These methods have facilitated not only lesion diagnosis but also qualitative assessment, and are being used to analyze pathophysiology. Comprehensive diagnoses based on such modalities may be important in determining indications for surgery or defining the extent of surgery or the intensity of other treatments. 相似文献
73.
Norbert Rilinger Johannes Görich Reinhard Scharrer-Pamler Jochen Vogel Reinhard Tomczak Elmar Merkle Roman Sokiranski Hans-Jürgen Brambs 《Cardiovascular and interventional radiology》1997,20(4):263-267
Purpose To evaluate the clinical results of percutaneous transluminal rotational atherectomy in the treatment of peripheral vascular
disease.
Methods Rotational atherectomy was performed in 39 patients aged 39–87 years (mean 66.6 years). A total of 71 lesions (43 stenoses
and 28 occlusions) were treated in 40 limbs. Additional balloon angioplasty was required in 54% of lesions. Fifteen patients
(37.5%) presented in Fontaine stage II, 10 patients (25%) in Fontaine stage III and 15 patients (37.5%) in Fontaine stage
IV. Rotational atherectomy at 750 rpm was carried out over a 0.014-inch guidewire with continuous aspiration into a vacuum,
bottle. Follow-up angiography and color flow Doppler examinations were performed in 22 patients (23 limbs) after a mean period
of 6 months (range 2–14 months)
Results There was one primary technical failure. In 36 of 40 lesions there was a good angiographic result with residual stenoses in
less than 30%. In 70 lesions treated by rotational atherectomy, however, 54% showed residual stenoses of 30%–50% and these
cases required additional balloon angioplasty. The mean ankle-brachial index improved significantly (p<0.001), from 0.49 before the procedure to 1.01 after the procedure. A single distal embolus, related to primary recanalization,
occurred and there were two large inguinal hematomas. Cumulative clinical patency after 6 months was 83.8% and cumulative
angiographic patency after 6 months was 79.1%.
Conclusion Percutaneous rotational atherectomy is a promising approach for the treatment of chronic peripheral vascular disease. Further
prospective, randomized studies are necessary to compare percutaneous transluminal angioplasty with this new technical approach. 相似文献
74.
Yancu Hertzanu M.D. Menachem Hirsch Louis Goleman 《Cardiovascular and interventional radiology》1987,10(4):230-233
Two unusual cases of delayed synthetic graft complications resulting from manufacturing defects of knitted Dacron are presented.
Computed tomography appears to be a suitable noninvasive alternative examination to angiography in this condition. 相似文献
75.
76.
Summary Transcutaneous oxygen, laser Doppler flowmetry, peroneal nerve motor conduction velocity and skin temperature were assessed in both legs of 34 diabetic patients, who had a mean age of 41 (range 29–77) years, and diabetes duration of 21 (3–34) years. Transcutaneous oxygen significantly correlated with peroneal nerve motor conduction velocity (r=0.59 p<0.001) and laser Doppler flowmetry (r=0.7 p<0.001). Laser Doppler flowmetry correlated weakly with peroneal motor conduction velocity, (r=0.34 p<0.05). In each patient the leg with the higher transcutaneous oxygen (mean 70.2±9.3 (SD) mmHg) had a significantly higher peroneal motor conduction velocity (45.3±7.1 vs 41.5± 6.3 m/s, p<0.01), than the leg with the lower transcutaneous oxygen (61.0±11.9 mm Hg), though no difference in skin temperature was observed, 31.4±0.4 vs 31.1±0.5°C. We then assessed the potential for reversibility of conduction velocity deficits in ten non-diabetic patients, aged 59 (52–77) years, undergoing unilateral femoro-popliteal bypass, measuring transcutaneous oxygen, peroneal nerve motor conduction velocity and skin temperature pre- and 6 weeks post-surgery. In the control leg (unoperated) there was no significant change in transcutaneous oxygen (63.2±8.8 vs 63.0±4.6 mm Hg), peroneal nerve motor conduction velocity (45.1±7.8 vs 43.4±7.2 m/s) or skin temperature (30.8±1.3 vs 30.2±1.2°C) after surgery (all NS). In the operated leg, transcutaneous oxygen increased from 59.3±10.7 to 70.7±7.2 mm Hg (p<0.01), and peroneal nerve motor conduction velocity from 42.6±6.1 to 46.7±3.2 m/s (p<0.01), but skin temperature was unchanged 30.3±0.4 vs 30.4± 1.3°C (NS). These studies provide further evidence that peripheral nerve function is associated with tissue hypoxia and that improving tissue oxygenation can significantly improve nerve conduction over a short period of time. 相似文献
77.
CO作用后大鼠肺血管细胞增殖和凋亡状况的研究 总被引:2,自引:0,他引:2
目的:通过研究CO和低氧作用后大鼠肺血管细胞增殖和凋亡状况,探讨低氧肺动脉高压的发病机制及防治措施。方法:应用免疫组织化学,原位末端标记及Western杂交等方法检测常压低氧大鼠肺血管壁细胞增殖,凋亡及c-myc基因的表达状况。结果:正常组,低氧和锡原卟啉组,低浓度CO和血晶素组大鼠肺动脉均存在增殖和凋亡的阳性细胞,两类细胞在肺内呈不均匀散在分布,低氧和锡原卟啉组大鼠肺血管增殖细胞数显著升高而凋亡细胞数显著减少,细胞增殖凋亡比值分别为对照组的5倍或4倍,而低浓度CO和血晶素组肺血管增殖细胞和凋亡细胞系数均显著增加,细胞增殖凋亡比值均为1.2,c-myc在低氧和锡原卟啉组大鼠肺内表达显著增加,在低浓度CO和血晶素组大鼠肺内表达减少。结论:增殖和凋亡现象共存在于正常和处理大鼠的肺血管细胞中,也许c-myc等基因的异常表达导致了细胞增殖和凋亡的失衡,进而调节了慢性低氧肺血管结构的改建。 相似文献
78.
Irwin S. Johnsrude William M. Bogey Jr Michael D. Tripp 《Cardiovascular and interventional radiology》1994,17(6):336-338
Discovery of a postlumbosacral discectomy fistula between the right iliac artery and vein was obscured by an associated severe stricture of the infrarenal inferior vena cava in a 49-year-old man. During venous stenting for treatment of peripheral edema, the fistula was suspected because of faint pulsatile right iliac vein flow and increased O2 saturation of the venous blood. The suspicion was confirmed on subsequent iliac arteriography. Surgical closure of the fistula with arterial interposition grafting was then performed. The patient improved substantially. 相似文献
79.
S. A. Carter 《Clinical physiology and functional imaging》1991,11(3):253-261
Summary. The effect of changes in local and body temperature on the toe systolic pressures was studied in 20 subjects with and 30 without Raynaud's syndrome in the toes. The pressures were significantly lower in the group with Raynaud's syndrome under all experimental conditions (P < 0·01). The pressures were significantly lower during body cooling than during body warming in both groups (P < 0·01). The mean decrease with body cooling was 58 mmHg in the group with Raynaud's syndrome and 24 mmHg in the control subjects (P < 0·01). During body cooling pressures fell to less than 30 mmHg in 70% of subjects with Raynaud's syndrome and in 3% of the controls. Local cooling from 30 to 10°C during body cooling resulted in a significant mean decrease in pressure of over 40 mmHg in both groups (P < 0·01) and the pressure fell below 30 mmHg in over 90% of the group with and in 26% of those without Raynaud's attacks. The results indicate the importance of body cooling and local temperature in the mechanism of vasospasm in the toes. They are also relevant to the diagnosis of Raynaud's syndrome in the lower limbs and have implications for the testing of patients with arteriosclerotic occlusion since erroneously low pressure values could be obtained in tests when the feet are cold. 相似文献
80.
Cardiovascular diseases (CVD) among non-communicable diseases are already a major public health challenge worldwide. A further increase in CVD is projected to occur over the next 25 years as a result of both adverse lifestyle changes and demographic shifts in the population age profile. The adverse impact of these health problems will affect women in particular, given the steady rise in the proportion of the aging population that will be women.The critical issue presently in the management of CVD is that we are not even adequately using the data that are available. Women still remain unaware that they are at risk, and information about women is not easily accessible to their physicians. This is a global issue and the need remains for worldwide initiatives with greater vigilance to identify these factors and make efforts to control them effectively.Currently, in scientific research, it is expected that the results of clinical research be analyzed for sex differences, sex- and gender-appropriateness, and sex- and gender-specific approaches for prevention, diagnosis, treatment, and counseling. To address the care discrepancy, the global community needs to develop a conducive environment within a comprehensive policy and operational framework to achieve favorable lifestyles, and CVD risk factor reduction for both men and women. 相似文献