全文获取类型
收费全文 | 1130篇 |
免费 | 112篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 69篇 |
妇产科学 | 24篇 |
基础医学 | 151篇 |
口腔科学 | 27篇 |
临床医学 | 133篇 |
内科学 | 317篇 |
皮肤病学 | 31篇 |
神经病学 | 111篇 |
特种医学 | 103篇 |
外科学 | 85篇 |
综合类 | 23篇 |
预防医学 | 50篇 |
眼科学 | 5篇 |
药学 | 55篇 |
肿瘤学 | 53篇 |
出版年
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 21篇 |
2020年 | 14篇 |
2019年 | 31篇 |
2018年 | 27篇 |
2017年 | 11篇 |
2016年 | 23篇 |
2015年 | 26篇 |
2014年 | 31篇 |
2013年 | 36篇 |
2012年 | 41篇 |
2011年 | 52篇 |
2010年 | 64篇 |
2009年 | 47篇 |
2008年 | 49篇 |
2007年 | 49篇 |
2006年 | 37篇 |
2005年 | 41篇 |
2004年 | 31篇 |
2003年 | 37篇 |
2002年 | 32篇 |
2001年 | 26篇 |
2000年 | 28篇 |
1999年 | 26篇 |
1998年 | 32篇 |
1997年 | 38篇 |
1996年 | 38篇 |
1995年 | 32篇 |
1994年 | 24篇 |
1993年 | 20篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 20篇 |
1988年 | 21篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 13篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 15篇 |
1978年 | 6篇 |
1977年 | 10篇 |
1976年 | 7篇 |
1974年 | 8篇 |
1971年 | 7篇 |
1970年 | 8篇 |
排序方式: 共有1247条查询结果,搜索用时 31 毫秒
101.
102.
MG Magaji JA Anuka I Abdu-Aguye AH Yaro I M Hussaini 《African journal of traditional, complementary, and alternative medicines》2008,5(2):147-153
Securinega virosa is used traditionally as sedative in children and in mental illnesses. In this study, the behavioral effects of methanolic root bark extract of S. virosa were investigated in mice. The results revealed that the extract significantly (P<0.05) and dose-dependently reduced the onset and prolonged the duration of sleep. The extract significantly (P<0.05) decreased exploratory activity and reduced the rate of apomorphine-induced stereotyped climbing at the doses tested (6.25–25mg/kg). It also produced a significant and dose-dependent motor coordination deficit in mice at the doses tested (P<0.01). The intraperitoneal median lethal dose in mice was 774.6mg/kg while the preliminary phytochemical screening revealed the presence of alkaloids, tannins, saponins and flavonoids. These results suggest that methanolic root bark extract of S. virosa contains biologically active principles that are sedative in nature and lend pharmacological credence to the ethnomedical use of the plant. 相似文献
103.
Chest computed tomography (CT), including high-resolution CT with thin (1.5-mm) sections was used to evaluate proved (pathologically or clinically) lymphangitic spread (LS) of tumor in 12 patients. These appearances were compared with thin-section scans obtained in 11 healthy subjects. Thin-section CT demonstrated findings consistent with thickening of the normal lung interstitium. In all patients, thin sections showed an increase in the number of peripheral lines (1-2 cm in length) that were diffuse in generalized disease and localized in focal disease. Normal peripheral arcades were not increased in number, but the limbs forming the arcades were thickened in all patients. A diffuse increase in linear and curvilinear structures (reticular pattern) was seen toward the center of the lung. Polygonal structures 1-2 cm in diameter were seen in seven patients with LS but not in healthy subjects. Fissures were thickened in nine patients. Selected 1.5-mm-thick CT sections are recommended through abnormal areas (seen at CT or on chest radiographs) or if these are normal at three levels (midapex, hilus, and 3 cm above the diaphragm) when scanning patients with tumors known to cause LS. 相似文献
104.
Obstetric and nonmalignant gynecologic bleeding: treatment with angiographic embolization 总被引:4,自引:0,他引:4
Eight patients (seven post partum, one post abortion) with massive pelvic hemorrhage related to pregnancy and one patient with uncontrollable bleeding following a cervical biopsy underwent angiography to facilitate the identification and treatment of bleeding sites. In all nine patients pelvic hemorrhage was successfully controlled with embolization under angiographic guidance. Angiographic embolization allowed preservation of the uterus in six patients referred prior to hysterectomy, and one patient subsequently became pregnant. When conservative measures and minor surgical repairs have failed, embolization should be the next step in the treatment of postpartum hemorrhage to avoid major surgery in an unstable patient and to maintain reproductive function. 相似文献
105.
MG Bøe R Salvesen & Å Mygland 《Cephalalgia : an international journal of headache》2009,29(8):855-863
Several studies have shown the benefit of withdrawal therapy when medication overuse headache (MOH) is suspected. Our aim was to compare the effect of withdrawal therapy in patients followed by a neurologist (group A, n = 42) and a primary care physician (PCP) (group B, n = 38). Patients were randomized to A or B, and follow-up was at 3, 6 and 12 months. Calculated mean headache (MH at 6 months + MH at 12 months)/2 (primary end-point) was similar; A 1.04 (0.87, 1.21) and B 1.02 (0.82, 1.21) ( P = 0.87). The number of patients with 50% improvement of headache days was also similar; 14/42 in group A vs. 12/34 in B ( P = 0.86) at 3 months, 15/42 vs. 11/33 ( P = 0.83) at 6 months and 15/42 vs. 14/38 ( P = 0.92) at 12 months. Days without headache during the last 9 months of follow-up were 123 (96, 150) in group A and 137 (112, 161) in B ( P = 0.62). After 3 months one-third were classified as MOH. Patients with MOH improved similarly in group A and B, and so did patients without MOH. Within 1 year 7/42 in A and 9/38 in B had recurrent medication overuse ( P = 0.43). In summary, there were no significant differences in follow-up results between the two groups. 相似文献
106.
M Ollier J C Maurizis C Nicolas J Bonafous M de Latour A Veyre J C Madelmont 《Journal of nuclear medicine》2001,42(1):141-145
The aim of this study was to investigate joint scintigraphy in rabbits with 99mTc-N-[3-(triethylammonio)propyl]-15ane-N5 (NTP 15-5), a new radiopharmaceutical that specifically localizes in cartilaginous tissues. METHODS: Scans obtained after intravenous injection of the 99mTc-labeled compound in normal and arthropathy-induced rabbits were compared with those of the bone-imaging agent 99mTc-methylene diphosphonate (99mTc-MDP). RESULTS: The radioactive uptake of 99mTc-NTP 15-5 was detected in cartilaginous tissues 5 min after injection and was stable for 2 h. The uptake intensity was related to age and joint disease severity, and cartilage alterations not revealed by radiography induced a significant decrease of radiotracer uptake. On the other hand, imaging performed with 99mTc-MDP did not reveal the early changes in arthrosis but was more specific for bone remodeling in advanced stages of diseases or in inflammatory processes. CONCLUSION: Our results indicate that 99mTc-NTP 15-5 could be a good tracer for human arthrosic and arthritic cartilage detection, especially for the early diagnosis of joint diseases. 相似文献
107.
108.
G Cloutier F Lemire L G Durand Y Latour Y E Langlois 《Ultrasound in medicine & biology》1990,16(3):247-260
The reliability of three algorithms to estimate the maximal and minimal frequency contours of Doppler spectrograms was evaluated in a group of 48 patients. Two algorithms had previously been used in the literature. These are the Modified Threshold Crossing Method and the Hybrid method. The third algorithm is new and is the Maximal Background Noise Threshold Crossing Method. A new approach was also proposed in the present study to estimate the background noise level of Doppler spectrograms. This level was used as a threshold in the computation of the spectral envelopes. Two diagnostic spectral parameters (the spectral envelope area and the systolic velocity integral) extracted from Doppler spectrograms recorded in the left ventricular outflow tract were also evaluated and tested to discriminate between 23 patients having no aortic pressure gradient and 25 patients with a stenotic aortic valve. Results describe the influence of the threshold level used in the Modified Threshold Crossing Method and the Hybrid method on the variability of the spectral contours. It is clearly demonstrated that the variability of minimal frequency contours is higher than that of maximal frequency contours. All three algorithms provided similar diagnostic performances with the spectral envelope area (71% to 73% of correct classifications) while the Maximal Background Noise Threshold Crossing Method and the Hybrid method provided the best results for the systolic velocity integral (69% of correct classifications). Because the systolic velocity integral combined with the continuity equation is used in the literature to evaluate noninvasively the aortic valve area, these results suggest the use of the spectral envelope area instead of the systolic velocity integral. 相似文献
109.
Jean-Marc Lavoie Raynald Bergeron Martin G Latour 《Revue canadienne de physiologie appliquée》2005,30(3):282-291
The first evidence that the liver can afferently contribute to regulatory activities comes from studies on regulation of food intake. The hepatic afferent pathway has been shown to be responsive to glucoprivic as well as lipoprivic stimuli. Similarly to regulation of food intake, it has been reported that the liver may afferently contribute to the metabolic regulation of exercise. The best reported evidence of this view is the observation that the decrease in insulin and the increase in glucagon and noradrenaline levels during exercise are diminished in hepatic vagotomized rats (Lavoie et al., 1989). The concept behind these observations is that the liver, through the existence of hepatic glucoreceptors, is responsive to a decrease in glycogen content or to some metabolites of the glycolytic chain related to liver glycogen content. There is also some evidence that lipids in the liver may have some regulatory impact inside and outside the liver. Recent interest in looking at lipid metabolism in liver has been spurred by the observation that the increased flux of lipids through the hepatic portal vein has been associated with increased risks of metabolic and cardiovascular abnormalities. To explore this avenue, a 10% triglyceride emulsion was infused into either the portal or a peripheral vein of rats for 48 hrs while another group of rats was acutely infused for 2 hrs into the portal vein. The results indicate that all of these lipid infusions resulted in an increase in liver lipid infiltration, which may be associated with the development of a state of hepatic and peripheral insulin resistance. 相似文献
110.
A case of angiography-proven multiple coarctations of the pulmonary arteries is presented. The patient had a history of long-standing exertional dyspnea and intranasal cocaine use. A chest radiograph suggested oligemia in the left lung and enlargement of the right pulmonary artery, prompting ventilation and perfusion radionuclide lung imaging. The combined scintigraphic and radiographic findings were indistinguishable from those caused by pulmonary emboli. Although rare, this entity should be included in the differential diagnosis of multiple unmatched perfusion defects on pulmonary ventilation-perfusion studies. 相似文献