全文获取类型
收费全文 | 579篇 |
免费 | 73篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 49篇 |
妇产科学 | 7篇 |
基础医学 | 61篇 |
口腔科学 | 27篇 |
临床医学 | 71篇 |
内科学 | 135篇 |
皮肤病学 | 19篇 |
神经病学 | 37篇 |
特种医学 | 78篇 |
外科学 | 40篇 |
综合类 | 17篇 |
预防医学 | 9篇 |
药学 | 84篇 |
肿瘤学 | 13篇 |
出版年
2023年 | 1篇 |
2022年 | 5篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 14篇 |
2014年 | 22篇 |
2013年 | 22篇 |
2012年 | 18篇 |
2011年 | 17篇 |
2010年 | 41篇 |
2009年 | 29篇 |
2008年 | 19篇 |
2007年 | 13篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 16篇 |
2002年 | 10篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 15篇 |
1998年 | 30篇 |
1997年 | 39篇 |
1996年 | 35篇 |
1995年 | 27篇 |
1994年 | 21篇 |
1993年 | 20篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 10篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1954年 | 1篇 |
排序方式: 共有657条查询结果,搜索用时 15 毫秒
41.
Between June 1986 and April 1988, 86 sonographic examinations of the shoulder were performed on patients suspected of having rotator cuff tears. Major sonographic diagnostic criteria included (a) a well-defined discontinuity usually visible as a hypoechoic focus within the cuff, (b) nonvisualization of the cuff and (c) an echogenic focus within the cuff. Seventy-five patients underwent both sonography and arthrography. Compared with arthrography alone, ultrasound examinations enabled detection of 92% of rotator cuff tears (24 of 26 tears), with a specificity of 84% and a negative predictive value of 95%. Correlation was obtained in 30 of these patients who underwent surgery for rotator cuff tear or other soft-tissue abnormality. In this group, the sensitivity of sonography for detection of a tear was 93%, with a specificity of 73%, while for arthrography sensitivity was 87% and specificity was 100%. These data indicate that sonography is a useful, noninvasive screening procedure for patients suspected of having rotator cuff injury. 相似文献
42.
Computed tomography of the pancreas 总被引:2,自引:0,他引:2
43.
Background
Chronic lymphocytic leukemia (CLL) is a monoclonal disorder, characterized by a progressive proliferation of functionally incompetent B lymphocytes. There is increased evidence of association between CLL and skin cancers, including the uncommon Merkel cell carcinoma (MCC). 相似文献44.
Birrell MA Wong S Hele DJ McCluskie K Hardaker E Belvisi MG 《American journal of respiratory and critical care medicine》2005,172(1):74-84
RATIONALE: Emphysema is one component of chronic obstructive pulmonary disease (COPD), a respiratory disease currently increasing in prevalence worldwide. The mainstay therapy adopted to treat patients with COPD is glucocorticoids; unfortunately, this treatment has limited impact on disease symptoms or underlying airway inflammation. OBJECTIVE: There is an urgent need to develop therapies that modify both the underlying inflammation, thought to be involved in disease progression, and the structural changes in the emphysematous lung. METHODS: We have characterized an elastase-driven model of experimental emphysema in the rat that demonstrates COPD-like airway inflammation and determined the impact of a clinically relevant glucocorticoid. MEASUREMENTS AND MAIN RESULTS: We observed an increase in lung neutrophils, lymphomononuclear cells, mucus production, and inflammatory cytokines. Also present were increases in average air space area, which are associated with emphysema-like changes in lung function, such as increased residual volume and decreased flow; these increases in area were maintained for up to 10 weeks. In addition, we observed that elastase-induced airway neutrophilia is steroid resistant. Interestingly, the inflammation observed after elastase administration was found to be temporally associated with a lack of nuclear factor-kappaB pathway activation. This apparent nuclear factor-kappaB-independent inflammation may explain why treatment with a glucocorticoid was ineffective in this preclinical model and could suggest parallels in the steroid-resistant human disease. CONCLUSION: We believe that this model, in addition to its suitability for testing therapies that may modify existing emphysema, could be useful in the search for new therapies to reduce the steroid-resistant airway inflammation evident in COPD. 相似文献
45.
There are currently no effective treatments for controlling the cough response with an acceptable therapeutic ratio. However, several new mechanisms have been identified which may lead to the development of new drugs. 相似文献
46.
Asthma and chronic obstructive pulmonary disease (COPD) are diseases of the airways with an underlying inflammatory component. The prevalence and healthcare burden of asthma and COPD is still rising and is predicted to continue to rise in the current century. The beta-agonists and corticosteroids form the basis of the treatments available to alleviate the symptoms of asthma, whereas the treatments available for COPD have been shown to have a limited effect on slowing the progression of the disease. Asthma and COPD are both in need of novel, safe treatments to tackle the underlying inflammation that characterises their pathology. The inflammatory processes inherent in asthma and COPD provide the opportunity for innovative drug research. This review will outline the new approaches and targets being investigated, which may provide opportunities for novel therapeutic interventions in these debilitating diseases. 相似文献
47.
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
48.
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
49.
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
50.
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