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61.
We have identified an autoantigen that is recognized by antibodies from an 18-year-old female with a history of recurrent infections who later in her clinical course developed Raynaud's phenomenon and telangiectasias. By indirect immunofluorescence (IIF), the index serum produced a unique cytoplasmic discrete speckled (CDS) staining pattern that partially colocalized with early endosome antigen 1 (EEA1) but not Golgi complex or other cytoplasmic organelles in HEp-2 cells. When HEp-2 cells were treated with 0.1 N HCl, the cytoplasmic speckled staining of the index serum was markedly decreased, suggesting that the reactive antigen was soluble. Western blot analysis showed a reactive approximately 97 kDa protein in a saline soluble protein preparation from HeLa cells. Mass spectrometric analysis of the excised 97 kDa band that was immunoprecipitated from HeLa cell extracts identified GRASP-1 as a possible target. The index serum and anti-GRASP-1 antibodies colocalized to structures in the cytoplasm of HEp-2 cells. Synthetic peptides representing the full-length GRASP-1 protein were used to identify reactive epitopes. Like many other cytoplasmic autoantigens, GRASP-1 has numerous coiled-coil domains throughout the protein with the exception of short segments at the amino and carboxyl terminus.  相似文献   
62.
Summary Development of third-stage larvae ofDipetalonema viteae within subcutaneously implanted micropore chambers proceeded in all hosts tested up to the fourth-stage larvae and occasionally to adolescent worms. In the jird the timing of development was comparable to a natural infection. Although the mouse is an insusceptible host, larval development could take place, but was very slow. Two intraperitoneal inoculations of living thirdstage larvae into mice induced the production of antibodies against the larval cuticle and against common antigens. In such immune mice the development of third- and fourth-stage larvae within micropore chambers was significantly inhibited, larval mortality was increased, and the larval motility was impaired.  相似文献   
63.
Maike Claußen  Beat Suter   《Annals of anatomy》2005,187(5-6):539-553
Many eukaryotic cells depend on proper cell polarization for their development and physiological function. The establishment of these polarities often involve the subcellular localization of a specific subset of proteins, RNAs and organelles. In Drosophila, the microtubule-dependent BicD (BicaudalD) localization machinery is involved in the proper localization of mRNA during oogenesis and embryogenesis and the proper positioning of the oocyte and photoreceptor nuclei. BicD acts together with the minus-end directed motor dynein as well as Egl and Lis-1. The finding that the mammalian homologs of BicD function in retrograde Golgi-to-ER transport has supported the view that BicD may be part of a repeatedly used and evolutionary conserved localization machinery. In this review we focus on the various processes in which BicD is involved during Drosophilian development and in mammals. In addition, we evaluate the interactions between BicD, the dynein localization machinery and associated factors.  相似文献   
64.
We aimed to define, for the first time, the ontogeny of intrarenal innervation and to assess the distribution and nature of parenchymal nerves in the human fetal kidney. Our material consisted of routinely-processed renal tissue sections from 17 human fetuses, six of 20–24 gestational weeks (gw) and 11 of 25–40 gw, and three adults. We used immunohistochemistry with antibodies to the pan-neural markers neuron-specific enolase (NSE), neurofilaments (NF), PGP9.5, S100, and the adrenergic marker tyrosine hydroxylase (TH). NSE-, NF-, S100-, and PGP9.5-positive nerves, associated with arterial and venous vasculature, were identified in the renal cortex from 20 gw onwards, and their density appeared to increase with gestation, reaching adult levels at 28 gw. Most of the intrarenal nerves were TH-positive. Nerve fibers extended from the corticomedullary region to the outer cortex, reaching the renal capsule in the 3rd trimester. In detail, NSE-, NF-, S100-, PGP9.5-, and TH-immunoreactive fibers were observed in close apposition to the renal artery and its branches, occasionally reaching the afferent and efferent arteriole (3rd trimester). Nerve fibers were detected in close apposition to the juxtaglomerular apparatus in the 2nd and 3rd trimesters. In the renal medulla, NSE-, PGP9.5-, S100-, and TH-positive nerve fibers were detected close to tubular cells as early as 20 gw. However, their density gradually decreased during the 3rd trimester, and they were not observed in the medulla of the adult kidney. In conclusion, the human fetal kidney appears richly innervated during the 2nd and 3rd trimesters. There is a progressive increase in the density of parenchymal nerve fibers towards term from the corticomedullary region to the cortex. Most intrarenal nerves are adrenergic and have a predominant perivascular distribution, implying that renal innervation plays an important functional role during intrauterine life.  相似文献   
65.
中学生学业能力倾向测验的初步编制   总被引:2,自引:1,他引:2  
目的:编制一个适用于中学生的学业能力倾向测验。方法:采用理论与工作分析相结合的编制策略而成的中学生学业能力倾向测验包括A、B两个复本,均由三个分量表含七个分测验组成,分别测量语文.数理及图形等能力。研究样本由河北省石家庄市1424名中学生组成,并对其中468人分别进行信效度检验。结果:①各分测验原始分基本随年级升高而增长;②各分测验难度在0.46~0.54。鉴别指数在0.38~0.52;③各分量表及总分的重测相关系数在0.68~0.92,α系数在0.64~0.89.G系数在0.64~0.92;④探索性因素分析表明各分测验对基本能力因子均有中度以上的负荷,抽取的三个因子解释了总方差的72.18%(A式)和73.53%(B式);⑤测验分数与长一鞍团体智力测验、与教师评价均呈显著正相关。测验分数在不同年级之间存在显著差异。学习成绩的回归分析可见,测验分数与考试成绩显著正相关,语文及数理分量表进入考试总成绩的回归方程。结论:中学生学业能力倾向测验的条目质量及信效度符合心理测量学的基本要求。  相似文献   
66.
The spinal cord is situated within the vertebral canal by the third month of intrauterine life. The spinal cord possesses two symmetrical enlargements, which constitute the segments of the plexuses the cervical enlargement for the brachial plexus and the lumbosacral enlargement for the lumbar and sacral plexus. In our study, we aimed to investigate the relationship between the termination level of the lumbosacral enlargement (TLLE) and that of the conus medullaris (TLCM) during the period of fetal development and adulthood. We used a total of 75 cases 25 fetuses (male 16, female 9) whose crown-rump length ranged between 90–190 mm, 25 premature and full-term neonates (male 17, female 8) whose post-menstrual ages ranged between 33–55 weeks, and 25 adults (male 12, female 13) aged between 22–72 years. The dissection technique for fetuses, ultrasonography for premature and full-term newborns, and magnetic resonance imaging (MRI) for adults were used to determine lumbosacral enlargement and TLCM. The differences between the TLCM and the termination level of the largest part of the transverse diameter of the lumbosacral enlargement were investigated. The differences between the TLLE and TLCM were found in different ratios from the period of fetal development to adulthood. Therefore, during medical treatment and surgical procedures this should be taken into account to avoid complications.  相似文献   
67.
Summary Experimental evidence indicates, that the myogenic cells themselves are not responsible for the muscle pattern formation. We report on a chance observation that reveals that muscle pattern formation can occur even in the absence of myogenic cells. Epiblastic cells from a quail embryo in the primitive streak stage were implanted into the wing bud of a chick embryo. The grafted quail cells developed into mononucleate, fibroblast-like cells that formed the muscle belly of the extensor medius longus muscle. This showed essentially normal form and topography as revealed by computer-aided 3D-reconstruction. This finding shows, that the formation of muscles does not depend on the presence of myogenic cells.  相似文献   
68.
69.
We have used an antibody against a TGFβ peptide fragment to localize this growth factor in the early chick embryo from laying to the ten-somite stage of development. Western blotting showed that the antibody reacted with both mammalian TGFβ1 and chicken TGFβ3. By immunocytochemistry we find that at the earliest developmental stage (stage X of Eyal-Giladi and Kochav) immunoreactivity to this antibody is primarily located in the cells of the area opaca and marginal zone, as well as in the most peripheral edge cells of the blastoderm. The yolk is non-reactive, except in a highly localized region subjacent to the edge cells. This pattern persists at stage XII, and at both stages individual isolated cells in the epiblast and hypoblast are also reactive. By the time to gastrulation, reactivity in the epiblast is polarized to the ventral extremity of the cells, and again some isolated cells in this layer are intensely immunoreactive. At this stage also, the endoderm cells, particularly those underlying the primitive streak, are positive, as are the mesoderm cells lateral to the streak. At somite stages, the neuroepithelium is not reactive but the ectoderm lateral to it is strongly positive. At the caudal primitive streak levels of early somite embryos, the ectoderm and endoderm are immunoreactive while the mesoderm loses the reactivity it showed at the early gastrulation stages. The neuroepithelial cells later show reactivity at their apical poles, and, as at the earlier stages, individual cells show intense labelling. These results indicate that TGFβ1 and/or TGFβ3 immunoreactivity is developmentally regulated from very early stages of morphogenesis in the chick, and together with data from earlier functional studies, suggest that this factor has roles in embryonic axis formation and in blastoderm expansion. © 1994 Wiley-Liss, Inc.  相似文献   
70.
Summary In the frog, Xenopus laevis, a system of intertectal connections underlies the visual projection from an eye to its ipsilateral tectal lobe and is involved in the topographic representation of binocular visual space. Rotation of one eye in early life may be followed by a radical rearrangement of the connections in this system. The modified pattern which later emerges is that which keeps the visual projection through the ipsilateral eye in topographic registration with the direct visual projection from the contralateral eye to the same tectal lobe. This plasticity requires visual experience.In this paper we describe the time-course and sequence of events by which this plasticity is effected. Following rotation of one eye in larval animals or in animals undergoing metamorphic climax, the earliest evidence of intertectal modification was found 3–4 weeks after metamorphosis. With increasing intervals after metamorphosis an increasing proportion of animals displayed modified intertectal systems. At intermediate intervals many animals showed partial modifications, which were interpreted as transitional stages in the modification process. Analysis of these transitional stages indicated that the sequence of events involved in the elaboration of a modified intertectal system following the experimental alteration of eye alignment exhibits features in common with rearrangements of the system that occur during normal development in response to growth-related alterations in eye alignment.  相似文献   
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