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Zusammenfassung Die natürliche intramolluskäre Entwicklung des Darmegels Isthmiophora melis verläuft über zwei morphologisch distinkte Redienformen: Auf zwei Generationen makropharyngeater Redien (Mutterredien) folgen nur noch Generationen mikropharyngeater Redien (Tochterredien) sowie Cercarien. Die Bildung von Mutterredien unterbleibt in Schnecken, die nur durch Implantation von Tochterredien experimentell infiziert wurden. Werden Schnecken nacheinander beiden Infektionsmodi unterworfen, der Tochterredienimplantation und der Miracidienexposition, so läßt sich aus dem Vorhandensein oder Fehlen von Mutterredien ablesen, welche der Infektionen von Erfolg war.Mittels dieser Methode wurde geprüft, ob Isthmiophora-parasitierte Lymnaea-Individuen gegen homologen Miracidienbefall resistent sind. Sie erwiesen sich als nicht resistent gegen Reinfektion, und zwar auch dann, wenn sie bereits in die Phase des Cercarienausstoßes eingetreten waren.
Experimental re-infection of Lymnaea stagnalis with Isthmiophora melis (trematoda, echinostomatidae) by exposition to miracidia after implantation of rediae
Summary The natural intramolluscular development of the intestinal fluke Isthmiophora melis takes place in two morphologically distinct forms of rediae: Two generations of macropharyngeate rediae (mother rediae) are followed only by generations of micropharyngeate rediae (daughter rediae) and cercariae. Mother rediae are not produced in snails infected by implantation of daughter rediae only. If snails are subjected to the implantation of daughter rediae and exposed to miracidiae successsively, the presence, or absence, of mother rediae indicates which of the infections has been successful.This method of investigation was used in order to ascertain whether Lymnaea individuals parasitized by Isthmiophora are resistant against invading miracidia of homologous species. They proved not resistant against re-infection, even if they had already entered the stage of shedding cercariae.


Ermöglicht durch Beihilfen der Deutschen Forschungsgemeinschaft.  相似文献   
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ObjectivesAssess the impact of a new pharmaceutical care model on (1) polypharmacy and (2) potentially inappropriate medication (PIM) use in long-term care facilities (LTCFs).DesignPragmatic quasi-experimental study with a control group. This multifaceted model enables pharmacists and nurses to increase their professional autonomy by enforcing laws designed to expand their scope of practice. It also involves a strategic reorganization of care, interdisciplinary training, and systematic medication reviews.Setting and ParticipantsTwo LTCFs exposed to the model (409 residents) were compared to 2 control LTCFs (282 residents) in Quebec, Canada. All individuals were aged 65 years or older and residing in included LTCFs.MeasuresPolypharmacy (≥10 medications) and PIM (2015 Beers criteria) were analyzed throughout 12 months between March 2017 and June 2018. Groups were compared before and after implementation using repeated measures mixed Poisson or logistic regression models, adjusting for potential confounding variables.ResultsOver 12 months, for regular medications, polypharmacy decreased from 42% to 20% (exposed group) and from 50% to 41% (control group) [difference in differences (DID): 13%, P < .001]. Mean number of PIMs also decreased from 0.79 to 0.56 (exposed group) and from 1.08 to 0.90 (control group) (DID: 0.05, P = .002).Conclusions and ImplicationsCompared with usual care, this multifaceted model reduced the probability of receiving ≥10 medications and the mean number of PIMs. Greater professional autonomy, reorganization of care, training, and medication review can optimize pharmaceutical care. As the role of pharmacists is expanding in many countries, this model shows what could be achieved with increased professional autonomy of pharmacists and nurses in LTCFs.  相似文献   
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A case of primary intracerebral plasma cell granuloma without meningeal attachment is presented. Histologically, the lesion showed two different patterns. At the center, it displayed the features of a benign fibrous histiocytoma. At the periphery, a mixture of polyclonal plasma cells, lymphocytes, and "epithelial-like" cells was observed. Electron microscopy and immunocytochemistry confirmed the histiocytic nature of the "epithelial-like cells." The differential diagnosis and histogenesis of such a lesion are discussed.  相似文献   
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Despite many efforts, the nature of thymic immigrants that give rise to T cells has remained obscure, especially since it became known that extrathymic lineage-negative, Sca-1-positive, c-kit high progenitor cells differ from intrathymic early T cell progenitors (ETPs) by functional potential and dependence on Notch signaling. After our observation that intrathymic T cell precursors expressing a human CD25 reporter under control of pre-TCRalpha regulatory elements almost exclusively have the ETP phenotype, we have analyzed the phenotypic changes of reporter-expressing common lymphoid progenitor (CLP) cells in the bone marrow when cultured on Delta-like 1-expressing stromal cells. We note that these quickly adopt the phenotype of double negative (DN)2 thymocytes with little display of the ETP phenotype. Our data suggest that common lymphoid progenitor (CLP) cells could be responsible for the rapid reconstitution of thymus function after bone marrow transplantation since CLP cells in the blood have the capacity to rapidly enter the thymus and become DN2 thymocytes.  相似文献   
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The immune response to local in vivo inhalation of a lysed bacteria vaccine was assessed in surgical specimens of main-stem bronchi from patients who had undergone pneumectomy for cancer. The patient population included 22 subjects; 11 of these received the aerosol vaccine twice a day for 10 days prior to surgery, while the remaining 11 patients were used as controls and were not immunized. The submucous glands of immunized subjects showed significantly more cells than did those of the controls, i.e., 62 +/- 8 versus 37 +/- 7, respectively (P less than 0.05). The following five antigens were chosen for study by fluorescence assay: Streptococcus pneumoniae types II and III, Haemophilus influenzae, Streptococcus sp. strain D19, and Klebsiella pneumoniae. An immunization-dependent correlation was found between immunoglobulin A, immunoglobulin A-bearing cells, and specific antibody-bearing cells on the one hand and three of the five antigens (S. pneumoniae types II and III and Streptococcus sp. strain D19) on the other hand. This is the first time that a relationship has been established between bacterial immunization of the lower respiratory tract and local immunoglobulin production in humans.  相似文献   
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Human skin reconstructs are three-dimensional in vitro models consisting of epidermal keratinocytes plated onto fibroblast-contracted collagen gels. Cells in skin reconstructs more closely recapitulate the in situ phenotype than do cells in monolayer culture. Normal melanocytes in skin reconstructs remained singly distributed at the basement membrane which separated the epidermis from the dermis. Cell lines derived from biologically early primary melanomas of the radial growth phase proliferated in the epidermis and the basement membrane was left intact. Growth and migration of the radial growth phase melanoma cells in the dermal reconstruct and tumorigenicity in vivo were only observed when cells were transduced with the basic fibroblast growth factor gene, a major autocrine growth stimulator for melanomas. Primary melanoma cell lines representing the more advanced stage vertical growth phase invaded the dermis in reconstructs and only an irregular basement membrane was formed. Metastatic melanoma cells rapidly proliferated and aggressively invaded deep into the dermis, with each cell line showing typical invasion and growth characteristics. Our results demonstrate that the growth patterns of melanoma cells in skin reconstructs closely correspond to those in situ and that basic fibroblast growth factor is critical for progression.  相似文献   
9.
Bone-marrow-derived cells can contribute nuclei to skeletal muscle fibers. However, serial sectioning of muscle in mdx mice implanted with GFP-labeled bone marrow reveals that only 20% of the donor nuclei chronically incorporated in muscle fibers show dystrophin (or GFP) expression, which is still higher than the expected frequency of "revertant" fibers, but there is no overall increase above controls over time. Obviously, the vast majority of incorporated nuclei either never or only temporarily turn on myogenic genes; also, incorporated nuclei eventually loose the activation of the beta-actin::GFP transgene. Consequently, we attempted to enhance the expression of dystrophin. In vivo application of the chromatin-modifying agents 5-azadeoxycytidine and phenylbutyrate as well as local damage by cardiotoxin injections caused a small increase in dystrophin-positive fibers without abolishing the appearance of "silent" nuclei. The results thus confirm that endogenous repair processes and epigenetic modifications on a small-scale lead to dystrophin expression from donor nuclei. Both effects, however, remain below functionally significant levels.  相似文献   
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BACKGROUND: The dermoscopic classification is a useful tool for handling patients with atypical naevi (Clark naevi). OBJECTIVES: To investigate if the dermoscopic classification of atypical naevi is of any value to discriminate benign from malignant melanocytic lesions. METHODS: Consecutive patients (n = 205) were included with 254 suspicious melanocytic lesions, confirmed by histopathology at the Pigmented Lesions Clinic of the Department of Dermatology, University Medical Center, University of Tuebingen, Germany. In this retrospective study, dermoscopic images of benign and malignant melanocytic lesions were classified according to the dermoscopic classification of atypical naevi (reticular, globular, homogeneous or combinations of two of these) and pigmentation (uniform, central hyper- or hypopigmentation, eccentric peripheral hyper- or hypopigmentation, or multifocal hyper- or hypopigmentation). The three-structure type (reticular, globular and homogeneous) was additionally defined. RESULTS: Reticular, homogeneous and reticular-homogeneous types were significantly more frequent in naevi than in melanomas, whereas the three-structure type was significantly more frequent in melanomas (P < 0.001). A sensitivity of 86.7%, specificity of 87.7% and diagnostic accuracy of 87.4% was obtained. Uniformly pigmented and centrally hyperpigmented types were significantly more frequent in naevi than in melanomas, whereas eccentric peripheral hyperpigmented and multifocal hyper- or hypopigmented types were significantly more frequent in melanomas (P < 0.001). CONCLUSIONS: The dermoscopic classification of atypical naevi (Clark naevi) is useful to discriminate benign from malignant melanocytic lesions. The three-structure type and eccentric peripheral hyperpigmentation were significantly more frequently found in malignant than in benign melanocytic lesions. The knowledge of these two dermoscopic types should be helpful for the management of patients presenting with multiple melanocytic lesions.  相似文献   
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