全文获取类型
收费全文 | 4065篇 |
免费 | 301篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 114篇 |
妇产科学 | 88篇 |
基础医学 | 703篇 |
口腔科学 | 41篇 |
临床医学 | 355篇 |
内科学 | 814篇 |
皮肤病学 | 197篇 |
神经病学 | 191篇 |
特种医学 | 293篇 |
外国民族医学 | 2篇 |
外科学 | 799篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 235篇 |
眼科学 | 67篇 |
药学 | 285篇 |
中国医学 | 3篇 |
肿瘤学 | 165篇 |
出版年
2021年 | 38篇 |
2020年 | 30篇 |
2019年 | 36篇 |
2018年 | 48篇 |
2017年 | 34篇 |
2016年 | 54篇 |
2015年 | 76篇 |
2014年 | 59篇 |
2013年 | 122篇 |
2012年 | 160篇 |
2011年 | 190篇 |
2010年 | 113篇 |
2009年 | 144篇 |
2008年 | 184篇 |
2007年 | 204篇 |
2006年 | 193篇 |
2005年 | 184篇 |
2004年 | 150篇 |
2003年 | 166篇 |
2002年 | 141篇 |
2001年 | 118篇 |
2000年 | 120篇 |
1999年 | 116篇 |
1998年 | 78篇 |
1997年 | 66篇 |
1996年 | 59篇 |
1995年 | 41篇 |
1994年 | 43篇 |
1992年 | 80篇 |
1991年 | 59篇 |
1990年 | 81篇 |
1989年 | 60篇 |
1988年 | 52篇 |
1987年 | 61篇 |
1986年 | 59篇 |
1985年 | 76篇 |
1984年 | 43篇 |
1983年 | 49篇 |
1982年 | 44篇 |
1981年 | 44篇 |
1980年 | 29篇 |
1979年 | 40篇 |
1978年 | 39篇 |
1977年 | 45篇 |
1976年 | 41篇 |
1975年 | 30篇 |
1973年 | 35篇 |
1971年 | 34篇 |
1970年 | 28篇 |
1969年 | 30篇 |
排序方式: 共有4392条查询结果,搜索用时 15 毫秒
1.
2.
Heidi Ulrich Michael Landthaler Thomas Vogt 《Journal der Deutschen Dermatologischen Gesellschaft》2007,5(6):493-495
The induction of a granulomatous inflammation by jellyfish toxins is rare. More typically, acute toxic and urticarial reactions are seen. An 11-year-old boy developed a striated urticarial erythema on the left cheek after contact with a gelatinous mass while swimming in the sea in Croatia. After initial erosion, a striated induration developed in the area of contact. Histological examination revealed a granulomatous inflammation with some eosinophils. While topical steroid-based antiinflammatory and antibacterial therapy over several weeks was not effective, topical therapy with tacrolimus 0.1% for two two-week treatment periods led to healing of the skin changes with a slight scar. There was no clinical recurrence after 5 month of follow-up. 相似文献
3.
4.
The pharmacokinetics and haemodynamic effects of isosorbide dinitrate (ISDN) have been investigated following administration of single doses as a sublingual (SL) spray (2.5 mg), sublingual tablet (5 mg) and peroral tablet (10 mg) in a randomised, placebo-controlled double-blind cross-over trial in 16 healthy volunteers.After the sublingual spray Cmax was higher (39.0 ng·ml-1) and tmax was shorter (3.9 min) than after the sublingual (22.8 ng·ml-1 and 13.8 min) and peroral (16.9 ng·ml-1 and 25.6 min) tablets. The AUC of ISDN did not differ following any of the three formulations (1031; 879; 997 ng·ml-1·min, for the spray, SL tablet and PO-tablet, respectively). Mononitrate metabolites of ISDN (IS-2-MN and IS-5-MN) and total nitrates in plasma increased in proportion to the administered dose. This indicates that the fraction of the dose absorbed was the same for all the formulations but that the extent of first-pass metabolism increased in the order sublingual spray < sublingual tablet < peroral tablet. Thus, compared to the spray, the relative bioavailability of ISDN was 48% and 28% from the sublingual and peroral tablets, respectively.The haemodynamic effects were quantified using the a/b ratio of the finger pulse wave and the systolic blood pressure and heart rate under orthostatic conditions. For the a/b ratio of the finger pulse, the maximal effect was higher (emax=130%) and the time to emax (temax) shorter (16.6 min) after the spray than the sublingual tablet (84.4% and 25.5 min) or peroral tablet (90.2 and 31.3 min). The onset of effect was within 3, 5 and 7.5 min after the spray, sublingual and peroral tablets, respectively. A larger change in the orthostatically-induced decrease in systolic blood pressure and increase in heart rate was obtained following peroral than sublingual administration despite the similar plasma concentrations of ISDN. This probably reflects the larger amount of pharmacodynamically active mononitrate metabolites formed after oral dosing. The integrated effect following administration of 2.5 mg ISDN as spray was similar to that of a sublingual tablet of 5 mg. 相似文献
5.
6.
Implantation of posterior chamber lenses in eyes with phakodonesis and lens subluxation 总被引:5,自引:0,他引:5
Unilateral posterior chamber intraocular lens (IOL) implantation was performed after phacoemulsification or extracapsular cataract extraction in ten of 11 patients with phakodonesis or lens subluxation, which was bilateral in two cases. To facilitate placement of the IOL, the anterior capsule was opened with a YAG laser in nine patients. Intraoperative vitrectomy was performed in two patients, and posterior chamber IOL implantation was accomplished with fixation in the ciliary sulcus. Postoperative follow-up studies failed to demonstrate significant decentration or dislocation of the IOLs. Phakodonesis and lens subluxation are no longer considered absolute contraindications to implantation of posterior chamber IOLs. 相似文献
7.
Objective:
Evaluation of the periodontal health in patients during treatment with either fixed orthodontic appliances or the Invisalign® system. 相似文献8.
9.
Florian M Vogt Gerald Antoch Patrick Veit Lutz S Freudenberg Nina Blechschmid Olaf Diersch Andreas Bockisch J?rg Barkhausen Hilmar Kuehl 《Journal of nuclear medicine》2007,48(11):1836-1844
Rimlike contrast enhancement on morphologic imaging and increased tracer uptake on (18)F-FDG PET in the periphery of the necrosis can hamper differentiation of residual tumor from regenerative tissue after radiofrequency ablation of liver lesions. This study used MRI, CT, ultrasound, and (18)F-FDG PET/CT to assess the typical appearance of lesions in nontumorous animal liver tissue after radiofrequency ablation. METHODS: Lesions were created by radiofrequency ablation of normal liver parenchyma in 21 minipigs. Follow-up was performed by 3 contrast-enhanced morphologic modalities-MRI, CT, and ultrasound-and by (18)F-FDG PET/CT immediately, 3 and 10 d, and 1, 2, 3, and 6 mo after radiofrequency ablation. Images were evaluated qualitatively for areas of increased enhancement and regions of elevated tracer uptake. Furthermore, all images were assessed quantitatively by determination of ratios comparing enhancement/tracer uptake in the periphery of the necrosis with enhancement/tracer uptake in normal liver parenchyma. Imaging findings were compared with histopathology findings. RESULTS: Immediately after radiofrequency ablation, no increase in (18)F-FDG uptake was visible, whereas elevated enhancement was noticed in the periphery of the necrosis on all morphologic imaging procedures. At further follow-up, an area of rimlike increase in (18)F-FDG uptake surrounding the necrosis was detected on PET/CT. The rimlike pattern of increased enhancement in the arterial phase was present for all liver lesions on CT, MRI, and ultrasound, especially between day 3 and month 1 after the radiofrequency ablation. Both elevated glucose metabolism and enhancement persisted for 6 mo postinterventionally. Histologic examination showed a hemorrhagic border converting into a regeneration capsule. CONCLUSION: If performed immediately after radiofrequency ablation, (18)F-FDG PET/CT probably has benefits over those of morphologic imaging procedures when assessing liver tissue for residual tumor. Later follow-up may be hampered by visualization of peripheral hyperperfusion and tissue regeneration. Further studies on a patient population are essential. 相似文献
10.
Cardiac efficiency and oxygen consumption measured with 11C-acetate PET after long-term cardiac resynchronization therapy. 总被引:2,自引:0,他引:2
Oliver Lindner Jens S?rensen Jürgen Vogt Eva Fricke Detlev Baller Dieter Horstkotte Wolfgang Burchert 《Journal of nuclear medicine》2006,47(3):378-383
Cardiac resynchronization therapy (CRT) is a treatment option in patients with severe heart failure and left bundle-branch block (LBBB). This study evaluated the effects of 4 and 13 mo of CRT on myocardial oxygen consumption (MVO2) and cardiac efficiency as compared with mild heart failure patients without LBBB. METHODS: Sixteen patients with severe heart failure and LBBB due to idiopathic cardiomyopathy were studied at baseline and after 4 and after 13 mo of therapy. Thirteen patients with mild heart failure without LBBB served as a comparison group. The clearance rate (k2) of 11C-acetate was measured with PET to assess MVO2. Stroke volume was derived from the dynamic PET data according to the Stewart-Hamilton principle and, furthermore, cardiac efficiency using the work metabolic index. RESULTS: After 4 mo of CRT, stroke volume index (SVI) increased by 50% (P = 0.012) and cardiac efficiency increased by 41% (P < 0.001). Global k2 remained unchanged but regional k2 demonstrated a more homogeneous distribution pattern. The parameters showed no significant changes during therapy. Under CRT, cardiac efficiency, SVI, and the distribution pattern of regional k2 did not differ from mild heart failure patients without LBBB. CONCLUSION: CRT improves cardiac efficiency for at least 13 mo, as demonstrated by a higher SVI, whereas MVO2 remains unchanged. Cardiac efficiency, SVI, and the MVO2 distribution pattern reach the level of patients with mild heart failure without LBBB. The unfavorable hemodynamic performance in heart failure with LBBB is effectively restored by long-term CRT to the level of an earlier disease state. 相似文献