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91.
Separation of dissociated thyroid follicular and parfollicular cells: association of serotonin binding protein with parafollicular cells 下载免费PDF全文
Parafollicular cells (PC) of the sheep thyroid gland are neural crest derivatives that synthesize and release the biogenic amine serotonin (5-HT) as well as the hormone calcitonin. The thyroid also contains a highly specific serotonin-binding protein (SBP). Separation of dissociated thyroid cells was done to study the cellular localization of SBP and to develop a means of isolating PC for study. Various methods were used to obtain an enriched and purified population of PC. Minced thyroid glands were enzymatically dissociated and the cells were layered on a Ficoll linear density gradient. Fractions obtained from the gradient were examined for cell number, viability, 5-HT concentration, SBP activity, and morphology by electron microscopy. One of the fractions was found to be enriched in PC. High levels of 5-HT and SBP were also found in this fraction, whereas these levels were low where the majority of cells were found. This PC-rich fraction, however, contained numerous follicular cells (FC); therefore, additional approaches to cell separation were used. FC can be stimulated in vitro with thyroid stimulating hormone (TSH) to become intensely phagocytic. When stimulated cells were incubated in the presence of silica microspheres, the FC engulfed the microspheres, which were toxic to them. PC did not become phagocytic and were unharmed by the microspheres. Suspended cells, after incubation with microspheres, were centrifuged on a discontinuous gradient, and a PC-rich fraction was obtained. Silica, however, interfered with analysis of SBP. Another method to take advantage of the phagocytic potential of FC was therefore used. TSH-stimulated cell suspensions were passed through a column of sepharose to which thyroglobulin had been coupled. Stimulated FC apparently adhered to the beads and were retained by the columns. Fractions eluting from the columns were greatly enriched with PC. These fractions contained high levels of 5-HT and SBP, and considerably reduced FC contamination was found by quantitative electron microscopy. It is concluded that SBP is localized to PC in the sheep thyroid. The idea that these cells resemble serotonergic neurons in their mechanisms of 5-HT storage is supported. 相似文献
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We describe an unusual case of chondroblastoma of the rib, initially presenting as a mediastinal mass eroding a vertebra, in which the preoperative diagnosis was made by fine needle aspiration (FNA) cytology and confirmed by histology and electron microscopy of the surgical specimen. Cytologic study of the smears revealed osteoclastlike giant cells and dishesive, mononucleate tumor cells; sections of the paraffin-embedded, aspirated material showed the chondroid matrix and typical chicken wire calcific deposits. Supporting diagnostic evidence was provided by immunohistochemical demonstration of S-100 protein. Unusual features were the presence of intranuclear pseudoinclusions and cytoplasmic granular deposits, which proved to contain iron on histochemical staining, ultrastructural morphology and x-ray analysis. This case emphasizes the value of FNA cytology in providing a correct diagnosis of chondroblastoma as well as the utility of embedding the aspirated material for histologic, immunohistochemical and ultrastructural studies. 相似文献
95.
Longitudinal study on the occurrence in pigs of colistin‐resistant Escherichia coli carrying mcr‐1 following the cessation of use of colistin 下载免费PDF全文
96.
Targeting the phosphatidylinositol 3‐kinase/Akt/mechanistic target of rapamycin signaling pathway in B‐lineage acute lymphoblastic leukemia: An update 下载免费PDF全文
97.
Phosphatidylinositol 3‐kinase inhibition potentiates glucocorticoid response in B‐cell acute lymphoblastic leukemia 下载免费PDF全文
Cecilia Evangelisti Alessandra Cappellini Mariana Oliveira Rita Fragoso João T. Barata Alice Bertaina Franco Locatelli Carolina Simioni Luca M. Neri Francesca Chiarini Annalisa Lonetti Francesca Buontempo Ester Orsini Andrea Pession Lucia Manzoli Alberto Maria Martelli Camilla Evangelisti 《Journal of cellular physiology》2018,233(3):1796-1811
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Vittorio Grill Marina Zweyer Renato Bareggi Alberto M. Martelli Marisa Basa Paola Narducci 《Biotechnic & histochemistry》1995,70(2):75-80
In this report we describe a simple and rapid staining technique for cartilage and bone embedded in Araldite. Semitbin sections of embryonic vertebrae obtained from 15 to 17 day mouse fetuses were stained using an aqueous solution 0.25% with respect to methylene blue, 0.25% with respect to azure A, and 0.5% with respect to Na2 CO3, then counterstained with 1% aqueous pararosaniline chloride (MAP). Results were compared with toluidine blue stained sections. MAP permitted good discrimination of developmental stages of both cells and extracellular matrix within vertebral ossification centers during endochondral ossification. The technique is simple, rapid and applicable to plastic embedded sections, and can be used prior to ultrastructural examination. 相似文献
100.
Luca M. Neri Frank O. Fackelmayer Marina Zweyer Terumi Kohwi-Shigematsu Alberto M. Martelli 《Chromosoma》1997,106(2):81-93
The nuclear matrix, a proteinaceous entity thought to be a scaffolding structure that determines the higher order organization
of eukaryotic chromatin, is usually prepared from intact nuclei by a series of extraction steps. In most cell types investigated,
the nuclear matrix does not spontaneously resist these extractions, but must rather be stabilized before the application of
extracting agents such as high salt solutions or lithium diiodosalicylate. We have examined the effect of two widely used
stabilization procedures on the localization of nuclear matrix proteins. Four individual polypeptides were studied, all of
which are scaffold or matrix-associated region (S/MAR)-binding proteins: SATB1, SAF-A/hnRNP-U, NuMA , and topoisomerase II
α. Nuclei were isolated from K562 human erythroleukemia cells in a buffer containing spermine, spermidine, KCl and EDTA, and
the nuclear matrix or scaffold was obtained by extraction with lithium diiodosalicylate after stabilization by heat treatment
(37° or 42°C) or incubation with Cu2+ ions. When the localization of individual proteins was determined by immunofluorescent staining and confocal scanning laser
microscopy, markedly different consequences of the two stabilization strategies became evident, ranging from a total maintenance
of the localization (NuMA and topoisomerase II α) to a marked redistribution (SATB1 and SAF-A/hnRNP-U). Our results seem to
indicate that a reevaluation of stabilization protocols employed for the preparation of the nuclear matrix is desirable, especially
by performing morphological controls.
Received: 22 January 1997; in revised form: 17 February 1997 / Accepted: 21 February 1997 相似文献