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31.
高强度聚焦超声终止小鼠妊娠的实验研究   总被引:1,自引:0,他引:1  
目的:探讨高强度聚焦超声(H IFU)终止妊娠的可能性。方法:利用H IFU治疗机(780 kHZ)6种声强各60s体内直接照射妊娠第7天小鼠胚胎,妊娠15 d时观察各组胚胎死亡率和胎盘、子宫的形态学变化。结果:对照组胚胎总死亡率为12.65%(32/253);照射组中声强3 W/cm2、6 W/cm2及≥9 W/cm2组的胚胎死亡率分别为25.00%(12/48)、72.88%(43/59)和100%(64/64、43/43、40/40、35/35)。超声照射后8 d的改变:光镜下主要为胎盘出血、变性、坏死;电镜下胎盘组织细胞坏死呈致密团块状,子宫改变轻微。变化随剂量的增加而明显。结论:胎盘较子宫对H IFU更敏感,更易受损,H IFU抗早孕具有潜在的可行性,值得进一步研究。  相似文献   
32.
Pore geometry characterization-methods are important tools for understanding how pore structure influences properties such as transport through a porous material. Bottlenecks can have a large influence on transport and related properties. However, existing methods only catch certain types of bottleneck effects caused by variations in pore size. We here introduce a new measure, geodesic channel strength, which captures a different type of bottleneck effect caused by many paths coinciding in the same pore. We further develop new variants of pore size measures and propose a new way of visualizing 3-D characterization results using layered images. The new measures together with existing measures were used to characterize and visualize properties of 3-D FIB-SEM images of three leached ethyl-cellulose/hydroxypropyl-cellulose films. All films were shown to be anisotropic, and the strongest anisotropy was found in the film with lowest porosity. This film had very tortuous paths and strong geodesic channel-bottlenecks, while the paths through the other two films were relatively straight with well-connected pore networks. The geodesic channel strength was shown to give important new visual and quantitative insights about connectivity, and the new pore size measures provided useful information about anisotropies and inhomogeneities in the pore structures. The methods have been implemented in the freely available software MIST.  相似文献   
33.
Writing has long been considered to be dependent on speaking. However, modality-specific dissociations between written and spoken word production imply that word production is supported by distinct neural mechanisms in writing, which can be impaired or spared regardless of the intactness of spoken word production. Rapp et al. (2015). Modality and morphology: What we write may not be what we say. Psychological Science, 26, 892–902 documented a double dissociation where problems with regular inflections were selectively restricted to writing or speaking. We report on two English-speaking aphasic individuals who exhibit this same modality-specific dissociation of inflectional processing, replicating the original findings. We expand on Rapp et al.’s study by examining whether the dissociations observed with regular inflections extend to other morphological forms, such as derivation and irregular inflection. Results showed that the dissociation holds for derivation; however, both participants were impaired with irregular inflections in both output modalities. Implications of these findings for morphological processing and the independence of the orthographic system are discussed.  相似文献   
34.
《Injury》2018,49(3):473-490
IntroductionClassification systems such as the Schatzker and AO/OTA have been proposed for standardised assessment of tibial plateau fractures and to guide clinical decision making. However, there has been no comprehensive literature review of all classification systems for tibial plateau fractures, including assessment of their reliability. The aim of this systematic review was to identify and appraise previously established classification systems for tibial plateau fractures and determine their reliability for fracture classification.MethodsSix databases were searched from inception until October 2016. Classification systems for tibial plateau fractures were identified. No restriction was placed on imaging modality (plain film X-ray, CT, MRI). Data synthesis was performed to identify common features of the systems, their prevalence within the literature and studies of intra and inter-rater reliability of fracture classification using Kappa coefficient (κ).ResultsThirty-eight classification systems were identified, five of which were a sub-classification of a single fracture type from a previous tool. The Schatzker and AO/OTA classification systems were the most commonly reported. Of the tools identified only five have been tested for inter and intra-observer reliability (Schatzker, AO/OTA, Duparc, Hohl and Luo). Reliability of more simplistic classification systems, such as that by Luo et al. (three-column) was typically high (intra-κ = 0.67–0.81, inter-κ = 0.71–0.87), but with the disadvantage of providing less information on fracture patterns and morphology. Intra and inter-observer reliability using plain film X-ray was frequently moderate (κ = 0.40–0.60), with 2D and 3D CT typically improving reliability of classification. Only 11 of the 32 complete classification systems identified association of fracture classification with clinical outcome.DiscussionFrequently used systems for classification of tibial plateau fractures display moderate intra and inter-observer reliability. More sophisticated imaging modalities such as 2D and 3D CT typically improve reliability estimates. Using fracture classification based on imaging findings to predict clinical outcome was not a commonly reported goal of newly developed systems. More detailed assessment of fracture patterns and morphology, in conjunction with information on surgical fixation, may be desirable for predicting outcomes and to guide clinical decision making.  相似文献   
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To improve the in vivo performance of engineered implants, this study examines the independent effects of surface chemistry and topography on fibroblast morphology and density in vitro. Titanium (Ti) was sputter-coated onto smooth and microtextured polyethylene terephthalate (PET). Test specimens were evaluated in 24-h, fibroblast cultures and assessed with scanning electron microscopy (SEM) for cellular morphology and density. Fibroblast density increased, as the Ti film thickness increased. The fibroblasts exhibited contact guidance on the textured test specimens. The greatest cellular density was found on the Ti-coated, textured test specimens. In conclusion, Ti and surface texture appeared to strongly influence fibroblast density and morphology as compared to PET and smooth surfaces.  相似文献   
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38.
Intraductal carcinoma of the prostate (IDC-P) is a malignant, clonal proliferation of cells growing within the basement membrane-bound structures of the prostate. IDC-P is usually associated with unfavorable clinicopathologic parameters such as large tumor volume, high-grade Gleason score, extra prostatic extension and seminal vesicle invasion. Majority of laboratory and patient data suggest that IDC-P represents intraductal spread of invasive carcinoma, rather than a precursor lesion. Additionally, relationship of IDC-P and adjacent invasive carcinoma has been investigated in a series of molecular studies. The differential diagnosis of IDC-P from other lesions is critical for patient management. In this article, we summarize current literatures regarding what we know about IDC-P, including its pathological morphology, incidence, differential diagnosis, molecular features and clinical significance. In addition, we propose several issues that we currently do not know about IDC-P. Further research is needed to better understand the biological nature of IDC-P.  相似文献   
39.
Hybrid imaging for ischemic heart disease refers to the fusion of information from a single or usually from multiple cardiovascular imaging modalities enabling synergistic assessment of the presence, the extent, and the severity of coronary atherosclerotic disease along with the hemodynamic significance of lesions and/or with evaluation of the myocardial function. A combination of coronary computed tomography angiography with myocardial perfusion imaging, such as single-photon emission computed tomography and positron emission tomography, has been adopted in several centers and implemented in international coronary artery disease management guidelines. Interest has increased in novel hybrid methods including coronary computed tomography angiography-derived fractional flow reserve and computed tomography perfusion and these techniques hold promise for the imminent diagnostic and management approaches of patients with coronary artery disease. In this review, we discuss the currently available hybrid noninvasive imaging modalities used in clinical practice, research approaches, and exciting potential future technological developments.  相似文献   
40.
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