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排序方式: 共有106条查询结果,搜索用时 15 毫秒
1.
Jasmine Chang Ian R. Porter Marnin A. Forman Natalya Shcherban Parminder S. Basran 《Veterinary radiology & ultrasound》2023,64(1):131-139
Measurements of intestinal wall thicknesses from ultrasound imaging (US) are routinely used to support diagnoses of intestinal disorders in cats, however published studies describing observer agreement are currently lacking. The aim of this retrospective, observer agreement study was to quantify inter- and intraobserver repeatability and agreement in the measurement of intestinal wall layer thicknesses and the segmentation of transverse sections of small intestines in US images of 20 cats. Intestinal wall layer thickness measurements of the mucosa, submucosa, muscularis, serosa layer, and total thickness of these layers were performed on five cats with small cell epitheliotropic lymphoma, five with inflammatory bowel disease, and 10 with other conditions. Thickness measurements and the segmentation encompassing the serosa layer were obtained from five observers four times non-sequentially. The average standard deviation in thickness measurements (95% confidence interval) in the mucosa, submucosa, muscularis, serosa, and total thickness were 0.35 (0.07–0.95), 0.24 (0.07-0.52), 0.22 (0.06-0.49), 0.20 (0.05-0.49), and 0.57 (0.11-1.60) mm, respectively. The average intraclass correlation coefficients, which estimates the degree of consistency in thickness measurements and segmentation areas for each observer, ranged from 0.355 to 0.870 and 0.850 to 0.993, respectively. The interclass correlation coefficient, which estimates the degree of consistency when measuring a thickness or segmentation area over all observers ranged from 0.115 to 0.753, and 0.811 to 0.902, respectively. The overall average Dice Coefficient, which estimates the extent of overlap of the segmentations for all observers was 0.957 (0.933 to 0.972). Our results suggest segmentations of small intestines have a higher interobserver agreement than measurements of intestinal wall thicknesses. 相似文献
2.
Dorothee Ehrich Maite Cerezo Anna Y. Rodnikova Natalya A. Sokolova Eva Fuglei Victor G. Shtro Aleksandr A. Sokolov 《BMC ecology》2017,17(1):32
Background
High latitude ecosystems are at present changing rapidly under the influence of climate warming, and specialized Arctic species at the southern margin of the Arctic may be particularly affected. The Arctic fox (Vulpes lagopus), a small mammalian predator endemic to northern tundra areas, is able to exploit different resources in the context of varying tundra ecosystems. Although generally widespread, it is critically endangered in subarctic Fennoscandia, where a fading out of the characteristic lemming cycles and competition with abundant red foxes have been identified as main threats. We studied an Arctic fox population at the Erkuta Tundra Monitoring site in low Arctic Yamal (Russia) during 10 years in order to determine which resources support the breeding activity in this population. In the study area, lemmings have been rare during the last 15 years and red foxes are nearly absent, creating an interesting contrast to the situation in Fennoscandia.Results
Arctic fox was breeding in nine of the 10 years of the study. The number of active dens was on average 2.6 (range 0–6) per 100 km2 and increased with small rodent abundance. It was also higher after winters with many reindeer carcasses, which occurred when mortality was unusually high due to icy pastures following rain-on-snow events. Average litter size was 5.2 (SD = 2.1). Scat dissection suggested that small rodents (mostly Microtus spp.) were the most important prey category. Prey remains observed at dens show that birds, notably waterfowl, were also an important resource in summer.Conclusions
The Arctic fox in southern Yamal, which is part of a species-rich low Arctic food web, seems at present able to cope with a state shift of the small rodent community from high amplitude cyclicity with lemming dominated peaks, to a vole community with low amplitude fluctuations. The estimated breeding parameters characterized the population as intermediate between the lemming fox and the coastal fox ecotype. Only continued ecosystem-based monitoring will reveal their fate in a changing tundra ecosystem.3.
Nikitin D. A. Ivanova E. A. Zhelezova A. D. Semenov M. V. Gadzhiumarov R. G. Tkhakakhova A. K. Chernov T. I. Ksenofontova N. A. Kutovaya O. V. 《Eurasian Soil Science》2020,53(12):1782-1793
Eurasian Soil Science - Quantitative characteristics of microbial communities in southern agrochernozems of the Stavropol region managed with the use of no-till technology and moldboard plowing... 相似文献
4.
The methanol, petroleum ether, ethyl acetate and water-methanol extracts of Ruta graveolens were found to possess antimicrobial and cytotoxic activities. 相似文献
5.
Tatyana A. Kuznetsova Natalya N. Besednova Larisa M. Somova Natalya G. Plekhova 《Marine drugs》2014,12(2):886-898
An important problem of treating patients with endotoxemia is to find drugs to reduce the negative effects of endotoxin on the organism. We tested fucoidan (sulfated polysaccharide) from the brown alga Fucus evanescens as a potential drug in a mouse model of endotoxemia inducted by lipopolysaccharide (LPS). The survival time of mice injected with LPS increased under fucoidan treatment compared with the group of mice injected with LPS only. The preventive administration of fucoidan to mice with endotoxemia resulted in inhibition of increased levels of proinflammatory cytokines (TNFα and IL-6), as well as decreasing of the processes of hypercoagulability. The parenteral or per os administration of fucoidan resulted in decreasing the degree of microcirculatory disorders and secondary dystrophic-destructive changes in parenchymal organs of mice with endotoxemia. Taken together, these results demonstrate that fucoidan prevents endotoxin-induced damage in a mouse model of endotoxemia and increases the mice’s resistance to LPS. 相似文献
6.
A. Yu. Avdeyev O. P. Kigashpaeva Yu. I. Avdeyev L. M. Ivanova 《Russian Agricultural Sciences》2014,40(2):96-99
The results of study of spontaneous fruit size and shape mutants and inheritance of these traits in tomato are given and genetic processes are explained. It is concluded that the diversity of tomato fruit shape and weight in the collection is due mainly to mutations of genes—diameter of fruit width and diameter of height joined into an ovate cluster. 相似文献
7.
Olesya I. Zhuravleva Alexandr S. Antonov Vo Thi Dieu Trang Mikhail V. Pivkin Yuliya V. Khudyakova Vladimir A. Denisenko Roman S. Popov Natalya Y. Kim Ekaterina A. Yurchenko Andrey V. Gerasimenko Anatoly A. Udovenko Gunhild von Amsberg Sergey A. Dyshlovoy Shamil S. Afiyatullov 《Marine drugs》2021,19(1)
Seven new deoxyisoaustamide derivatives (1–7) together with known compounds (8–10) were isolated from the coral-derived fungus Penicillium dimorphosporum KMM 4689. Their structures were established using spectroscopic methods, X-ray diffraction analysis and by comparison with related known compounds. The absolute configurations of some alkaloids were determined based on CD and NOESY data as well as biogenetic considerations. The cytotoxic and neuroprotective activities of some of the isolated compounds were examined and structure-activity relationships were pointed out. New deoxyisoaustamides 4–6 at concentration of 1 µM revealed a statistical increase of PQ(paraquat)-treated Neuro-2a cell viability by 30–39%. 相似文献
8.
Teodora Ivanova Mihail Chervenkov Tatyana Stoeva Stoyan Chervenkov Yulia Bosseva Almira Georgieva Elina Tsvetanova Albena Alexandrova Dessislava Dimitrova 《Genetic Resources and Crop Evolution》2018,65(5):1349-1357
Allium siculum Ucria is a perennial bulbous plant that occurs in Bulgaria as A. siculum subsp. dioscoridis (Sm.) K. Richt. The plant is locally known as “samardala”. Its herbage is used traditionally by local communities in Bulgaria as edible green and for preparation of salty spice mixtures. The study was focused on the documentation of traditional knowledge about samardala, covering local collection and cultivation practices, processing methods and consumption preferences. The respondents (aged 30–86 years, 50% over 65) were local producers and small-scale salesmen of the herbage and samardala-containing spices. To assess the health features of samardala spices the total phenol and flavonoid content was measured in home-consumed or marketed flavoured salts. Overall appreciation of the plant and related food products was found to be very high; presenting a considerable engagement of the locals in plant cultivation and gathering, laborious processing and consumption. Traditional ecological knowledge about the biology, phenology and ecology of the samardala plant and methods for its processing is still preserved by elderly people who rely mostly on their own cultivated plants. Although the introduction of modern appliances has altered the method of production, its main stages and the recipes are preserved. Modernization of the processing method has not affected the quality of the products and faster processing could be a contributing factor for the higher content of biologically active substances. Phenolic content was about twice as low as the flavonoid content, following the same pattern for all tested flavoured salts. Measures for better management of natural populations and promotion of cultivation practices of A. siculum subsp. dioscoridis would ensure the sustainable quality of traditional products as well as conservation of the natural plant resources. 相似文献
9.
10.
Induced parthenogenesis as a possible method of haploidization in sunflower (H. annuus L.) was tested in previous investigations
(Todorova et al., 1994) and conditions for reproducible regeneration of gynogenic doubled haploids were established by the
present work. Forty eight treatments were studied, involving four pollen donors and four recipient hybrids. Pollen was irradiated
with doses of 300 Gy, 600 Gy and 900 Gy. In total, 2279 embryos were cultivated in vitro of which 1107 plants were obtained
and 582 of them produced seeds after selfing. The ploidy level of the regenerants was evaluated at the two – three leaf stage
and 296 of the plantlets obtained were haploids. Some of them underwent spontaneous diploidization, the others were treated
with colchicine solution for chromosome doubling. The diploid plantlets were checked for their gynogenic origin by genetical
and biochemical methods. The effectiveness of the method expressed as the number of agronomically useful DH lines to the number
obtained that were fertile and resistant to downy mildew, branched and unbranched plants was 8,6% on average.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献