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排序方式: 共有1330条查询结果,搜索用时 15 毫秒
31.
32.
S. Benkaddour R. Slimani H. Hiyane I. El Ouahabi I. Hachoumi S. El Antri S. Lazar 《Sustainable Chemistry and Pharmacy》2018
The aim of this study is to valorize the watermelon seeds treated with hexane for the removal of reactive yellow 145 from aqueous solutions. The effects of physico-chemical parameters such as pH, adsorbent dose, temperature and dye concentration on the removal of dyes were evaluated. The kinetic study of the adsorption of reactive yellow 145 on watermelon seeds adsorbent perfectly followed the pseudo-second-order kinetic model. The Langmuir, Freundlich, Temkin, Elovich and Dubinin-Radushkevich models were studied. It was proved that the experimental data fitted well to the Freundlich model, which signifies that the phenomenon of adsorption is done in multilayers on heterogeneous surfaces. The finding of this paper asserts that this material is a good and low-cost adsorbent that can be used for the removal of dyes from aqueous solutions. 相似文献
33.
El-Banna Hanaa Samy El Khouly Radwa Mostafa Gado Souzan Ezzat 《Clinical rheumatology》2020,39(5):1627-1632
Clinical Rheumatology - To determine the role of Interleukin-34 (IL-34) in the pathogenesis of juvenile systemic lupus erythematosus (J-SLE), by exploring the relationship between IL-34... 相似文献
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35.
Barnard A Layton D Hince M Sakkal S Bernard C Chidgey A Boyd R 《Neuroimmunomodulation》2008,15(1):7-18
The nervous, endocrine, and immune systems interact to adapt to infection, inflammation, and tissue injury. Neural control is mediated in several ways, one of them being through the neuroendocrine regulation of the secretion of hypothalamic and pituitary hormones. The hormonal effects on the immune system range from the impact of steroidal hormones, which exhibit inhibitory effects over immune functions, to growth hormone, prolactin and neurohypophyseal hormones, known to stimulate and modulate humoral and cellular aspects of the immune system. This review will discuss the mechanisms behind the immunomodulatory role of the neuroendocrine system, including the critically important feedback loops required to maintain balance for these bidirectional interactions and alterations that occur with age. 相似文献
36.
Objectives: Genes encoding for cytokines have been associated with susceptibility for joint osteoarthritis (OA) and interleukin (IL)-1 gene is supposed to be involved in the cartilage destruction process. In this regard, interleukin-1 receptor antagonist (IL-1RA) competing with IL-1 for binding to its receptor may act as an inhibitor of cartilage breakdown. We assessed the association of primary knee OA with IL-1RA region as a putative factor of susceptibility to knee OA in Egyptian patients.
Design and methods: Eighty patients with primary knee OA and 40 aged-matched healthy controls were included into the study. DNA samples were used to study genotypes of IL-1RN gene by polymerase chain reaction (PCR) in both groups.
Results: An increased frequency of the IL-1RN*1 and IL-1RN*2 alleles was found in OA patients relative to controls (60.5% vs. 39.5%, P = 0.039, 85.4% vs. 14.6%, P = 0.002, respectively) however, only the carriage rate of IL-1RN*2 allele was found to be significant when OA patients were compared to the controls. Significant higher frequencies of IL-1RN*1/*2 and IL-1RN*2/*2 genotypes in OA patients were observed as compared with controls. Both visual analogue scale (VAS) and radiographic score revealed significant correlation with both the allelic frequency and the carriage rate of IL-1RN*2 allele. Moreover, absolute frequency of IL-1RN*1/*2 genotype OA patients revealed severe VAS and high radiographic score.
Conclusion: These results suggest that IL-1RN*2 allele represent a significant factor influencing the severity and course of knee OA; thereby supporting the potential role of IL-1 in the pathogenesis of this disease. 相似文献
37.
Avinash Ayyalasomayajula Andrew Polk Anirban Basudhar Samy Missoum Lavi Nissim Jonathan P. Vande Geest 《Annals of biomedical engineering》2010,38(1):164-176
An aneurysm is a gradual and progressive ballooning of a blood vessel due to wall degeneration. Rupture of abdominal aortic
aneurysm (AAA) constitutes a significant portion of deaths in the US. In this study, we describe a technique to reconstruct
AAA geometry from CT images in an inexpensive and streamlined fashion. A 3D reconstruction technique was implemented with
a GUI interface in MATLAB using the active contours technique. The lumen and the thrombus of the AAA were segmented individually
in two separate protocols and were then joined together into a hybrid surface. This surface was then used to obtain the aortic
wall. This method can deal with very poor contrast images where the aortic wall is indistinguishable from the surrounding
features. Data obtained from the segmentation of image sets were smoothed in 3D using a Support Vector Machine technique.
The segmentation method presented in this paper is inexpensive and has minimal user-dependency in reconstructing AAA geometry
(lumen and wall) from patient image sets. The AAA model generated using this segmentation algorithm can be used to study a
variety of biomechanical issues remaining in AAA biomechanics including stress estimation, endovascular stent-graft performance,
and local drug delivery studies. 相似文献
38.
Samy A. Madbouly Joshua U. Otaigbe Toshiaki Ougizawa 《Macromolecular chemistry and physics.》2006,207(14):1233-1243
Summary: Nanoscale polymer blend morphologies, with a dispersed minor phase as small as 50 nm, have been prepared via the in situ polymerization of macrocyclic carbonates in the presence of a maleic anhydride poly(propylene) (mPP). This simple, versatile, low cost strategy successfully produced a well‐defined, stable two phase nanoscale morphology with a considerable improvement in the ultimate mechanical properties and strong resistance to hydrocarbon solvents such as methylene chloride. The effect of blend composition on the rate of polymerization of the macrocyclic carbonates was studied by considering the increase in torque during the mixing process in the batch mixer. The polymerization rate decreased considerably with increasing concentration of mPP in the blend due to the formation of graft copolymer of polycarbonate‐g‐poly(propylene) (PC‐g‐PP). The viscoelastic behavior of the pure polymer components was found to play no role in controlling the blend morphology and size of the dispersed nanoscale particles. The blend morphology could be controlled by the compatibilization of the blend components, possibly via in situ formation of a graft copolymer. In addition, the blend morphology was strongly influenced by the value of the rotation speed (rpm) or shear rate encountered during the processing of the blends, i.e., the larger the rpm value, the finer the observed blend morphology. Both DSC and DMA data showed evidence of partial miscibility of the polymer blend components. In addition, the DMA data confirmed a preferential dissolution of mPP in polycarbonate (PC) instead of dissolution of PC in mPP as evidenced by the shift of the α‐relaxation process of the PC‐rich phase to lower temperatures while the α‐relaxation process of the mPP was relatively unaffected regardless of the PC composition. The percentage of mPP dissolved in PC was evaluated from the reduction in the Tg value (obtained from DSC data) of PC in the blend using the Fox equation and was found to be consistent with the DMA data and preferential dissolution of mPP in PC.
39.
Cloud point temperatures (Tcp) and crystallization temperatures (Tl/s) were measured at different constant shear rates for the ternary system tetrahydronaphthalene/poly(ethylene oxide)/oligo(dimethyl siloxane‐b‐ethylene oxide) using a rheo‐optical device and in the case of Tl/s additionally a viscometer. This system enables for the first time a joint investigation of both transitions with a given mixture. Shear favors the homogeneous liquid state and the formation of crystals. Tcp (liquid/liquid demixing, UCST) shifts to lower and Tl/s (liquid/solid, segregation of PEO) to higher temperatures by several degrees as the shear rate, , is increased up to 500 s?1. The normalized shift in Tcp fits well into previous results for high molecular weight blends, oligomer mixtures, polymer solutions in single solvents and low molecular weight mixtures. A phase separated near critical blend was examined 1 K below its Tcp by means of a shear cell (Linkam) in the quiescent state and under shear with respect to its morphology. Upon an increase in one observes a transition from the co‐continuous structures existing in the quiescent state via deformed and oriented particles to string like morphologies. Finally, at sufficiently high shear rates the mixture becomes homogeneous and structures can no longer be seen under the microscope. The morphologies developing after the secession of shear are pointing to pronounced influences of the flow history of the system on the final structure of two phase blends.
40.
Patrick Adam Samy Hakroush Ilse Hofmann Sonja Reidenbach Alexander Marx Philipp Ströbel 《Virchows Archiv : an international journal of pathology》2014,465(3):313-320
Due to its profound therapeutic consequences, the distinction between thymoma and T-lymphoblastic lymphoma in needle biopsies is one of the most challenging in mediastinal pathology. One essential diagnostic criterion favouring thymoma is the demonstration of increased numbers of keratin-positive epithelial cells by immunohistochemistry. Loss of keratin expression in neoplastic epithelial cells could lead to detrimental misdiagnoses. We here describe a series of 14 thymic epithelial tumours (11 type B2 and B3 thymomas, 3 thymic carcinomas) with loss of expression of one or more keratins. Cases were analysed for expression of various keratins and desmosomal proteins by immunohistochemistry and immunofluorescence and compared with 45 unselected type B thymomas and 24 thymic carcinomas arranged in a multitissue histological array. All 14 cases showed highly reduced expression of at least one keratin, three cases were completely negative for all keratins studied. Of the 14 cases, 13 showed strong nuclear expression of p63. Expression of desmosomal proteins was preserved, suggesting intact cell contact structures. Loss of expression of broad-spectrum-keratins and K19 was observed in 3 and 5 % of unselected thymomas and in 30 and 60 % of thymic carcinomas. A proportion of keratin-depleted thymomas contained giant cells, reminiscent of thymic nurse cells. Loss of keratin expression in type B2 and B3 thymomas is an important diagnostic pitfall in the differential diagnosis with T-lymphoblastic lymphoma and can be expected in 5 % of cases. A panel of epithelial markers including p63 is warranted to ensure correct diagnosis of keratin-negative mediastinal tumours. 相似文献