全文获取类型
收费全文 | 1292篇 |
免费 | 80篇 |
专业分类
1372篇 |
出版年
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 11篇 |
2019年 | 20篇 |
2018年 | 27篇 |
2017年 | 23篇 |
2016年 | 24篇 |
2015年 | 49篇 |
2014年 | 43篇 |
2013年 | 63篇 |
2012年 | 84篇 |
2011年 | 80篇 |
2010年 | 61篇 |
2009年 | 50篇 |
2008年 | 62篇 |
2007年 | 61篇 |
2006年 | 49篇 |
2005年 | 52篇 |
2004年 | 50篇 |
2003年 | 44篇 |
2002年 | 48篇 |
2001年 | 42篇 |
2000年 | 36篇 |
1999年 | 30篇 |
1998年 | 9篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 10篇 |
1994年 | 19篇 |
1993年 | 10篇 |
1992年 | 31篇 |
1991年 | 25篇 |
1990年 | 16篇 |
1989年 | 22篇 |
1988年 | 24篇 |
1987年 | 13篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 13篇 |
1980年 | 10篇 |
1978年 | 6篇 |
1977年 | 3篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1974年 | 3篇 |
1972年 | 3篇 |
1970年 | 7篇 |
排序方式: 共有1372条查询结果,搜索用时 0 毫秒
111.
Glaura Caroena Matsuyoshi Mori Marcos R.R. Gesualdi Edson A. Liberti Eduardo Ferrara Mikiya Muramatsu 《Journal of biomechanics》2010,43(4):680-686
The purpose of this work was the force–displacement response analysis of the masticatory process in a dried human skull by Double-Exposure Photorefractive Holographic Interferometry Technique (2E-PRHI). The load concentration and dissipation of the forces from dried human skull were analysed at applied loading stands as a Simulation of Isolated Contraction (SIC) of some mastication muscles. The 2EHI and Fringe Analysis Method were used to obtain the quantitative results of this force–displacement response. These results document quantitatively the real biomechanical response from dried human skull under applied loading and it can be used for complementary study by finite element model and others analysis type. 相似文献
112.
Bernardo Pascual J. Vicente Maroto SAlvador LóPez-Galarza Alberto Sanbautista José Alagarda 《Economic botany》2000,54(4):439-448
Tubers ofCyperus esculentuswere an important food in ancient Egypt. In Spain the tubers are used to make a beverage named horchata, and are also consumed as fresh after soaking. In other countries tubers are used in sweetmeats or uncooked as a side dish. New products obtained can enhance the interest in this crop: as a source of dietary fiber in food technology; as a high quality cooking/salad oil or as biodiesel fuel; as caramel to add body, flavor or color to other products; as a source of starch; as an antioxidant-containing food, etc. The results of a twenty-year research program on nutrition, fertilization, lodging control, planting date, soil texture and use of herbicides are shown. Three cultivars (‘Ametlla Bonrepos’, ‘Gegant Africana’, and ‘Llargueta Alboraia’) are selected and characterized using horticultural and morphological traits, the chemical composition of tubers and horchatas, and the RAPD technique. 相似文献
113.
Two Lower Liassic sections of the Banos de Alhama de Granada outcrop are studied. The Hettangian and Sinemurian ammonite assemblages are detailed and a reinterpretation of the stratigraphy of the outcrop made.The ammonites collected show a clear mediterranean character. A biostratigraphy for the Hettangian and Sinemurian can be made but the correlation with the northeuropean zonal divisions and chronostratigraphy is rather difficult. These are the only west mediterranean sections where a succession of Hettangian ammonite assemblages have been made. 相似文献
114.
Tepper BJ Koelliker Y Zhao L Ullrich NV Lanzara C d'Adamo P Ferrara A Ulivi S Esposito L Gasparini P 《Obesity (Silver Spring, Md.)》2008,16(10):2289-2295
Objective: Variation in the bitter‐taste receptor gene, TAS2R38 confers the ability to taste 6‐n‐propylthiouracil (PROP). The objective of this study was to relate TAS2R38 haplotypes and PROP‐tasting phenotypes to adiposity in a genetically isolated population. We hypothesized that the nontaster phenotype would be associated with higher BMI and waist circumference (WC) in females, and that dietary restraint would mediate this relationship. Methods and Procedures: Participants were 540 healthy inhabitants of the genetically isolated village of Carlantino in southern Italy who were 15–89 years of age at the time of the study. Haplotype analyses were performed and PROP tasting was assessed using a filter paper method. Height, weight, and WC were measured and restrained eating was assessed using a brief questionnaire. Results: Nontaster females had higher BMI and WC than females who were phenotypic tasters, and this relationship was specific to females with low dietary restraint. Regression analysis showed that BMI declined by 1.7 units across taster groups in females when the model included the PROP by restraint interaction. PROP phenotype was not significantly associated with WC in the regression models. Polymorphisms in TAS2R38 were not associated with BMI or WC in females. Neither TAS2R38 haplotype nor PROP phenotype was strongly related to BMI or WC in males. Discussion: These data support previous findings of a relation between the nontaster phenotype and higher BMI in females that is modified by dietary restraint. Assessment of PROP phenotypes might provide unique information about adiposity that is not captured by haplotype analysis alone. 相似文献
115.
Scala E Alessandri C Palazzo P Pomponi D Liso M Bernardi ML Ferrara R Zennaro D Santoro M Rasi C Mari A 《PloS one》2011,6(9):e24912
Background
IgE recognition of panallergens having highly conserved sequence regions, structure, and function and shared by inhalant and food allergen sources is often observed.Methods
We evaluated the IgE recognition profile of profilins (Bet v 2, Cyn d 12, Hel a 2, Hev b 8, Mer a 1, Ole e 2, Par j 3, Phl p 12, Pho d 2), PR-10 proteins (Aln g 1, Api g 1, Bet v 1.0101, Bet v 1.0401, Cor a 1, Dau c 1 and Mal d 1.0108) and tropomyosins (Ani s 3, Der p 10, Hel as 1, Pen i 1, Pen m 1, Per a 7) using the Immuno-Solid phase Allergen Chip (ISAC) microarray system. The three panallergen groups were well represented among the allergenic molecules immobilized on the ISAC. Moreover, they are distributed in several taxonomical allergenic sources, either close or distant, and have a route of exposure being either inhalation or ingestion.Results
3,113 individuals (49.9% female) were selected on the basis of their reactivity to profilins, PR-10 or tropomyosins. 1,521 (48.8%) patients were reactive to profilins (77.6% Mer a 1 IgE+), 1,420 (45.6%) to PR-10 (92.5% Bet v 1 IgE+) and 632 (20.3%) to tropomyosins (68% Der p 10 IgE+). A significant direct relationship between different representative molecules within each group of panallergens was found. 2,688 patients (86.4%) recognized only one out of the three distinct groups of molecules as confirmed also by hierarchical clustering analysis.Conclusions
Unless exposed to most of the allergens in the same or related allergenic sources, a preferential IgE response to distinct panallergens has been recorded. Allergen microarray IgE testing increases our knowledge of the IgE immune response and related epidemiological features within and between homologous molecules better describing the patients'' immunological phenotypes. 相似文献116.
The invasion kinetics ofhobo transposable element in theDrosophila melanogaster genome was studied byin situ hybridization on the polytene chromosomes. Six independent lines ofDrosophila melanogaster flies that had been previously transformed by microinjection of the pHFL1 plasmid containing a completehobo element were followed over 50 generations. We observed thathobo elements were scattered on each of the chromosome arms, with more insertion sites on the 3R arm. The total number of insertion sites remains quite small, between four and six, at generation 52. On the 2R arm, a short inversion appeared once at generation 52. Most of the integration sites reported here were already described for several transposons but some of them appear to be hotspots forhobo elements. 相似文献
117.
118.
Tobacco cells are sensitive to bleomycin and phleomycin. The Tn5 and the Streptoalloteichus hindustanus (Sh) bleomycin resistance (Ble) genes conferring resistance to these antibiotics have each been inserted into two plant expression vectors. They are flanked by the nopaline synthase (nos) or the cauliflower mosaic virus (CaMV) 35S promoters on one side, and by the nos polyadenylation signal on the other. These four chimaeric genes were introduced into the binary transformation vector pGA 492, which were thereafter mobilized into Agrobacterium tumefaciens strain LBA 4404. The resulting strains were used to transform Nicotiana tabacum cv. Xanthi nc using the leaf disc transformation procedure. In all cases, phleomycin- and bleomycin-resistant tobacco plants were regenerated from transformed cells under selective conditions; however the highest frequency of rooted plants was obtained when transformation was carried out with the Sh Ble gene under the control of the 35S promoter. Phleomycin resistance was stably transmitted to sexual offspring as a dominant nuclear trait as confirmed by Southern blotting. 相似文献
119.
Chloe I. Bloom Christine M. Graham Matthew P. R. Berry Fotini Rozakeas Paul S. Redford Yuanyuan Wang Zhaohui Xu Katalin A. Wilkinson Robert J. Wilkinson Yvonne Kendrick Gilles Devouassoux Tristan Ferry Makoto Miyara Diane Bouvry Valeyre Dominique Guy Gorochov Derek Blankenship Mitra Saadatian Phillip Vanhems Huw Beynon Rama Vancheeswaran Melissa Wickremasinghe Damien Chaussabel Jacques Banchereau Virginia Pascual Ling-pei Ho Marc Lipman Anne O’Garra 《PloS one》2013,8(8)
120.