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111.
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Marielle Ernst Levente Kriston Javier M. Romero Andreas M. Fr?lich Olav Jansen Jens Fiehler Jan-Hendrik Buhk 《PloS one》2016,11(2)
Purpose
We sought to develop a standardized curriculum capable of assessing key competencies in Interventional Neuroradiology by the use of models and simulators in an objective, quantitative, and efficient way. In this evaluation we analyzed the associations between the practical experience, theoretical knowledge, and the skills lab performance of interventionalists.Materials and Methods
We evaluated the endovascular skills of 26 participants of the Advanced Course in Endovascular Interventional Neuroradiology of the European Society of Neuroradiology with a set of three tasks (aneurysm coiling and thrombectomy in a virtual simulator and placement of an intra-aneurysmal flow disruptor in a flow model). Practical experience was assessed by a survey. Participants completed a written and oral examination to evaluate theoretical knowledge. Bivariate and multivariate analyses were performed.Results
In multivariate analysis knowledge of materials and techniques in Interventional Neuroradiology was moderately associated with skills in aneurysm coiling and thrombectomy. Experience in mechanical thrombectomy was moderately associated with thrombectomy skills, while age was negatively associated with thrombectomy skills. We found no significant association between age, sex, or work experience and skills in aneurysm coiling.Conclusion
Our study gives an example of how an integrated curriculum for reasonable and cost-effective assessment of key competences of an interventional neuroradiologist could look. In addition to traditional assessment of theoretical knowledge practical skills are measured by the use of endovascular simulators yielding objective, quantitative, and constructive data for the evaluation of the current performance status of participants as well as the evolution of their technical competency over time. 相似文献113.
114.
Alginate may be considered as a block co-polymer of D-mannuronic and L-guluronic acids, and consists of three types of blocks: homopolymeric blocks of mannuronic acid (MM) and of guluronic acid (GG), and blocks with an alternating sequence (MG). The block composition of alginates has been characterized by a simple chemical method involving partial hydrolysis with acid, followed by fractional precipitation of the acid-resistant part of the alginate. Alginates from eleven different species of brown algae have been examined and, for five species, alginates from different tissues have been compared. The results indicate that young tissue is rich in MM blocks, and that the difference between the alginates from different species is mainly due to the alginates from the older parts of the plants. Extracellular alginates from two types of bacteria have been examined. 相似文献
115.
Investigation of a toxic water-bloom of Microcystis aeruginosa (Cyanophyceae) in Lake Akersvatn,Norway 总被引:1,自引:1,他引:0
Kjetil Berg Wayne W. Carmichael Olav M. Skulberg Christel Benestad Bjarne Underdall 《Hydrobiologia》1987,144(2):97-103
During the summer and fall of 1984 and 1985, the eutrophic Lake Akersvatn in south-eastern Norway, used as reserve drinking
water reservoir, was found to produce heavy water-blooms of the colonial blue-green alga Microcystis aeruginosa. Samples of the water-bloom were found to be toxic using the mouse bioassay. No toxin was found free in the water as detected
by HPLC and mouse bioassay. The toxic cells (minimum lethal dose 8–15 mg/kg body weight in mice) and purified toxin (minimum
lethal dose 50 μg/kg body weight in mice) showed signs of poisoning in laboratory rats and mice identical to that of other
hepatotoxin-producing M. aeruginosa blooms and strains reported from other parts of the world. The toxin has chemical properties similar to the cyclic heptapeptide
reported for a South African M. aeruginosa toxin. The toxin from Lake Akersvatn bloom material has a molecular weight of 994. The toxic bloom of M. aeruginosa persisted from August to November in 1984 and reappeared in July of 1985. While water from Lake Akersvatn was not used for
municipal water supply during this period, the presence of toxic blue-green algae in a drinking water reservoir indicates
the need to develop monitoring and detection methods for toxic cells and toxin(s). 相似文献
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The proteolytic enzymes produced by 11 Salmonella species of the Sub-genera I, II and IV, have been compared by a so-called enzymo-serological procedure. In sub-genus I, the enzymes of S. schleissheim and S. abortus-bovis showed an identical, or closely related, serological picture, whereas S. texas was serologically distinct. All the 7 examined strains of sub-genus II produced proteolytic enzymes which were serologically very similar, or identical. No enzymo-serological cross-reactions were observed between these organisms and the members of sub-genus I. The only examined species of sub-genus IV, S. argentina, was enzymo-serologically distinct from all other species. Intergeneric cross-reactions occurred between the enzymes from Salmonella species, Enterobacter (Aerobacter) cloacae and Serratia marcescens. The significance of these cross-reactions is discussed. 相似文献
119.
The investigations indicate that a variety of non-dialyzable proteins and peptides, including hemoglobins, blood serum proteins, casein, soy protein and hydrolyzed proteins (peptones) are able to neutralize the bacteriocidal effect of lysolecithin. A number of lysolecithin-resistant bacteria are shown to produce lysolecithin-inhibiting metabolites that also promote growth of sensitive organisms in lysolecithin-containing media. On lysolecithin-con- taining agar this can result in a characteristic satellite growth of sensitive organisms around resistant “mother colonies”. Stable resistant mutants were easily selected from a wild type of Staphylococcus aureus after heavy inoculation on lysolecithin-containing nutrient agar. The bacterial lysolecithin-neutralizing factors examined are not considered to be of enzymatic nature. The factors in culture filtrate of Escherichia coli were separated into two active fractions by gel filtration. Due to extremely small amounts of the substances responsible for the neutralizing activity, chemical analyses of these fractions proved problematic, and only a few amino acids could be demonstrated. The neutralizing activity of the bacterial factors, and some of the proteins and peptides, resisted 100° C, or more, for several min. Some aspects of the lysolecithin-inhibitor-interaction are discussed. 相似文献
120.
The cell cycle distribution of bone marrow cells from the femurs of female C3H mice has been investigated by flow cytometry according to the time of the day and month of the year. Both circadian and seasonal variations were found for the different cell cycle phases as well as the total cell numbers per femur. Both the mesor, the acrophase and the amplitude of the S, G2 and (G1 + G0) phases varied significantly in some months, while in other months only insignificant rhythms were found. The relative cell cycle distribution only partly reflected variations in the total numbers of proliferating cells, since the total cell number per femur was also variable.
The total numbers of cells in DNA synthesis seem to be higher in the first part of the year, indicating increased cell proliferation during winter and spring. In this period the acrophases of DNA synthesis and G2 were in the morning, while the second half of the year showed the peak later in the day.
In general, hemopoietic cell proliferation seems to constitute a labile equilibrium with rapidly changing activities. 相似文献
The total numbers of cells in DNA synthesis seem to be higher in the first part of the year, indicating increased cell proliferation during winter and spring. In this period the acrophases of DNA synthesis and G2 were in the morning, while the second half of the year showed the peak later in the day.
In general, hemopoietic cell proliferation seems to constitute a labile equilibrium with rapidly changing activities. 相似文献