全文获取类型
收费全文 | 591篇 |
免费 | 17篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 21篇 |
妇产科学 | 7篇 |
基础医学 | 55篇 |
口腔科学 | 8篇 |
临床医学 | 39篇 |
内科学 | 74篇 |
皮肤病学 | 9篇 |
神经病学 | 69篇 |
特种医学 | 94篇 |
外科学 | 54篇 |
综合类 | 29篇 |
预防医学 | 25篇 |
眼科学 | 1篇 |
药学 | 90篇 |
中国医学 | 1篇 |
肿瘤学 | 18篇 |
出版年
2021年 | 5篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 15篇 |
2012年 | 13篇 |
2011年 | 8篇 |
2010年 | 17篇 |
2009年 | 8篇 |
2008年 | 5篇 |
2007年 | 12篇 |
2006年 | 17篇 |
2005年 | 17篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 18篇 |
2001年 | 16篇 |
2000年 | 18篇 |
1999年 | 11篇 |
1998年 | 26篇 |
1997年 | 31篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1994年 | 23篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 14篇 |
1990年 | 13篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 9篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1974年 | 7篇 |
1973年 | 5篇 |
1971年 | 7篇 |
1961年 | 4篇 |
1959年 | 4篇 |
1956年 | 4篇 |
1955年 | 5篇 |
排序方式: 共有615条查询结果,搜索用时 0 毫秒
131.
In a multicenter double-blind study, 44 patients suffering from eczema were bilaterally treated with 0.1% fluprednidene-21-acetate over 21 days. Continuous application twice a day was compared with intermittent therapy, i.e. 1 day intermission (15 patients), 2 days intermission (16 patients) and 3 days intermission (13 patients) using the cream base. Final evaluation was based on 11 criteria. All regimens, continuous and intermittent, proved effective (at least 90% reduction of the lesions). Treatment with 3 days intermission showed the same favorable results as continuous application, although the amount of glucocorticoids applied was 75% less. Measurements of the skin fold thickness (SFT) in healthy controls did not indicate any atrophy after treatment with fluprednidene under the same conditions as the eczema patients or under occlusion for up to 21 days. Clobetasol-17-propionate, in contrast, significantly reduced the SFT already after application of only 1 week. 相似文献
132.
There is increasing evidence that metabolic imaging with positron-emission tomography (PET) using fluor-18 labeled fluorodeoxyglucose (18F FDG) is highly accurate for in vivo detection of a variety of malignancies. This quality gives FDG-PET an important role in the detection of malignant tumors and their metastases as well as for differentiation of tumors of unknown etiology. In the male and female reproductive tract, whole body imaging with FDG-PET is in particular capable of visualizing lymph-node and distant metastases before these changes become apparent on conventional cross-sectional imaging modalities. According to the incidence of tumors in the reproductive tract, FDG-PET-imaging has been evaluated in prostate cancer, ovarian cancer, cervical and testicular cancer. The role of PET is discussed with respect to the current management of patients. The presented data indicate that FDG-PET is more accurate for lymph-node staging in cervical cancer and testicular cancer. In ovarian cancer, FDG-PET may be helpful for detection of tumor recurrence. The role of FDG-PET is questionable in prostate cancer, due to the low metabolic activity of this type of cancer. Carbon-11 labeled acetate and carbon-11 or fluor-18 labeled choline are more promising than FDG for detection of recurrence in prostate cancer. In all other tumors of the reproductive tract there is limited experience with PET for a final conclusion. 相似文献
133.
134.
135.
HK Iversen 《Cephalalgia : an international journal of headache》1995,15(4):281-287
The need for valid human experimental models of headache is obvious. Several compounds have been proposed as headache-inducing agents, but only the nitroglycerin (NTG) model has been validated. In healthy subjects, intravenous infusions of the nitric oxide (NO) donor NTG induce a dose-dependent headache and dilatation of the temporal, radial and middle cerebral artery. NTG-induced headache, although less intense, resembles migraine in pain characteristics, but the accompanying symptoms are rarely present. Cephalic large arteries are dilated during migraine headache as well as during NTG headache. N-acetylcysteine enhances the formation of NO and potentiates NTG-induced headache, whereas mepyramine, a H1 -antagonist capable of blocking histamine-induced headache, has no effect. Thus, the headache is dependent on NO or other steps in the NO cascade. The model is useful for pharmacological interventions and sumatriptan reduced the NTG-induced headache. The NTG model may be a valuable tool in the development of future migraine drugs. 相似文献
136.
A modified speech tracking procedure was investigated to determine the effects of controlling connected discourse materials and of specific prompting techniques on tracking rate and subjects' responses. In addition, comprehension was tested after subjects completed the tracking task. Two experiments were conducted with normally hearing subjects, one in which subjects tracked in an auditory plus noise condition and the second in which they tracked in a visual-alone condition. The results of these two experiments showed significant differences between tracking rates for controlled versus uncontrolled materials for both modalities, with higher tracking rates observed for the controlled materials. The use of specific prompting techniques reduced intertester variability in both modalities. Further, results indicated that comprehension ability and tracking skill are not perfectly related. 相似文献
137.
We showed earlier that the memory-improving substance, methylglucamine orotate, a precursor of pyrimidine nucleotide synthesis, improved memory retention and enhanced the postconditioning potentiation of field potentials in a special learning task. Since long-term potentiation (LTP) is frequently regarded as a mechanism of memory formation, we decided to test whether it can be influenced in a similar manner. The present study shows that the same dose of methylglucamine orotate (225 micrograms i.c.v.) prolongs LTP but has only a slight effect on the field potential recorded in the dentate gyrus. In controls, LTP of the population spike returned to 154% of the control value 24 h after tetanization and to 126% after 48 h. However, in drug treated animals LTP of the population spike remained at 246 and 216% of the control, respectively. The results support the assumption that LTP is at least a component of memory formation. 相似文献
138.
Calcium-induced long-term potentiation in the hippocampal slice: Characterization of the time course and conditions 总被引:1,自引:0,他引:1
K.G. Reymann H.K. Matthies U. Frey V.S. Vorobyev H. Matthies 《Brain research bulletin》1986,17(3):291-296
A transient increase in extracellular calcium concentration causes a long-lasting enhancement of radiatum fibers evoked excitatory postsynaptic potential and population spike responses of CA1 pyramidal neurons which resembles long-term potentiation (LTP). The duration of this potentiation is much longer than described previously and is probably limited by the survival of the preparation itself (greater than 8 hr). Therefore, Ca-induced LTP can be used for the investigation of a postulated late phase of LTP. Ca effects were activity-independent, since the subsequently evoked responses were facilitated even when the presynaptic fibers were not concurrently stimulated during or immediately after superfusion with the high Ca medium. In contrast, if too frequent testing of the synaptic input was done during the high Ca pulse, a short lasting depression instead of potentiation was observed. A lower extracellular magnesium concentration in the standard medium (1.3 instead of 2.0 mM MgSO4) prevents the potentiation of the EPSP at least for the first few hours. Presumably, both tetanus- and Ca-induced LTP share some common mechanisms, since an additional tetanization after Ca induction was not followed by an additional LTP. Compared to the potentiation following tetanization, the Ca-induced LTP was, however, not accompanied by a potentiation of the EPSP/spike ratio within the range of the population spike threshold intensity. 相似文献
139.
HK Larsen AG Danielsen D Krustrup K Weismann 《Journal of the European Academy of Dermatology and Venereology》2005,19(5):634-637
Neutrophil dermatosis of the dorsal hands (NDDH) is a recently described skin manifestation regarded as a subset of acute febrile neutrophilic dermatotis (Sweet syndrome). We describe 5 cases with pustular and ulcerative plaques and/or bullae and vesicles of the dorsal hands. Three of the patients also had skin changes at sides other than the hands. Associated conditions were found in two patients, one patient treated with hemo-dialysis for chronic glomerulonephritis, and one patient had suffered from a streptococcal tonsillitis prior to the eruption. Two of the patients had fever, two had neutrophil leucocytosis in peripheral blood and two had elevated sedimentation rates. Histological findings showed signs of vasculitis in biopsies from two of the patients. NDDH is discussed on the basis of prior case reports concerning the subject, and it is concluded that Neutrophil dermatosis of the dorsal hands should be regarded as a localized variety of Sweet syndrome. 相似文献
140.
Brönneke Jan Benedikt Hagen Julia Kircher Philipp Matthies Henrik 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2021,64(10):1285-1291
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Aufgrund der schnell voranschreitenden Digitalisierung wird sich auch die Gesundheitsversorgung in den nächsten Jahren stark... 相似文献