全文获取类型
收费全文 | 145篇 |
免费 | 5篇 |
专业分类
林业 | 8篇 |
农学 | 2篇 |
基础科学 | 1篇 |
46篇 | |
综合类 | 8篇 |
农作物 | 28篇 |
水产渔业 | 14篇 |
畜牧兽医 | 25篇 |
园艺 | 6篇 |
植物保护 | 12篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 22篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 6篇 |
2005年 | 1篇 |
2004年 | 2篇 |
2002年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有150条查询结果,搜索用时 15 毫秒
141.
Esmaeilzade B Nobakht M Joghataei MT Rahbar Roshandel N Rasouli H Samadi Kuchaksaraei A Hosseini SM Najafzade N Asalgoo S Hejazian LB Moghani Ghoroghi F 《Iranian Biomedical Journal》2012,16(1):1-9
Background: Alzheimer’s disease (AD) is characterized by progressive neuronal loss in hippocamp. Epidermal neural crest stem cells (EPI-NCSC) can differentiate into neurons, astrocytes and oligodendrocytes. The purpose of this study was to evaluate the effects of transplanting EPI-NCSC into AD rat model. Methods: Two weeks after induction of AD by injection of Amyloid-β 1-40 into CA1 area of rat hippocamp, Y-maze and single-trial passive avoidance tests were used to show deficit of learning and memory abilities. EPI-NCSC were obtained from the vibrissa hair follicle of rat, cultured and labeled with bromodeoxyuridine. When Alzheimer was proved by behavioral tests, EPI-NCSC was transplanted into CA3 area of hippocamp in AD rat model. The staining of EPI-NCSC markers (nestin and SOX10) was done in vitro. Double-labeling immunofluorescence was performed to study survival and differentiation of the grafted cells. Results: We showed that transplanted EPI-NCSC survive and produce many neurons and a few glial cells, presenting glial fibrillary acidic protein. Total number of granule cells in hippocamp was estimated to be more in the AD rat model with transplanted cells as compared to AD control group. We observed that rats with hippocampal damage made more errors than control rats on the Y-maze, when reward locations were reversed. Conclusion: Transplanted cells were migrated to all areas of hippocamp and the total number of granule cell in treatment group was equal compared to control group. Transplantation of EPI-NCSC into hippocamp might differentiate into cholinergic neurons and could cure impairment of memory in AD rat model.Key Words: Alzheimer’s disease, Cholinergic neuron, Hair follicle 相似文献
142.
Langoni H Greca H Guimarães FF Ullmann LS Gaio FC Uehara RS Rosa EP Amorim RM Da Silva RC 《Veterinary parasitology》2011,177(1-2):50-54
Neosporosis and toxoplasmosis are two important infections in young and adult sheep, leading to low production and abortion. This study aimed to determine the frequency of antibodies to Toxoplasma gondii and Neospora caninum in sheep from the eastern region of S?o Paulo State, Brazil. Serum samples (382) were collected from the sheep and assayed for T. gondii through modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT), and for N. caninum antibodies, through IFAT, with cut-off titers equal to 16 (T. gondii) and 25 (N. caninum). All frozen samples were sent to the Center for Zoonoses Research (NUPEZO), Department of Veterinary Hygiene and Public Health (DHSVP), FMVZ, UNESP, for serological tests. A total of 71/382 (18.6%) samples reacted to T. gondii, especially at titers 16 (28; 39.4%), 64 (15; 21.1%), 256 (21; 29.6%) and 1024 (6; 8.5%) by MAT, and 16 (34; 47.9%), 64 (18; 25.4%), 256 (14; 19.7%) and 1024 (5; 7%) by IFAT. As regards N. caninum, 49/382 (12.8%) samples reacted at titers 25 (17; 34.7%), 50 (11; 22.5%), 100 (11; 22.5%), and ≥ 200 (10; 20.4%). These animals presented infection but no clinical signs. Six and ten animals had high titers for toxoplasmosis and neosporosis. No significant association was observed between antibodies for both parasites (P=0.535) according to Fisher's exact test, and no correlation was found between T. gondii (MAT) and N. caninum antibody titers (r=-0.0068; P=0.895), T. gondii (IFAT) and N. caninum antibody titers (r=-0.0025; P=0.961). Thus, T. gondii and N. caninum infections were observed in farms located in S?o Paulo State, where sheep play an important economical role for the national and regional business. 相似文献
143.
144.
145.
Bruno Bianch Loureiro Fernanda Rodrigues Goulart Fernanda Teixeira Macagnan Sharine Nunes Descovi Naglezi de Menezes Lovatto Thais Soares dos Santos Marina Osmari Dalcin Leila Picolli da Silva 《Aquaculture Nutrition》2019,25(5):1115-1123
The aim of this study was to assess the effect of increasing inclusion levels (100, 150, 200 and 300 g/kg) of rice bran protein concentrate (RBPC) in jundiá (Rhamdia quelen) diets using growth, body composition, somatic indices and digestive enzyme activity as parameters. Five isoproteic (370.08 ± 0.04 g/kg) and isocaloric (13.38 ± 0.04 MJ/kg) diets were formulated with four replicates per treatment. After acclimation, 500 jundiá juveniles (initial mean weight of 6.28 ± 0.12 g) were distributed into 20 round polyethylene tanks (280 L) (25 fish per tank) coupled to a thermoregulated water recirculating system. The fish were fed experimental diets three times daily (at 9:00, 13:00 and 17:00 hr) to apparent satiation. At the end of the trial (45 days), no significant differences were found in the body chemical composition, somatic indices, and trypsin and chymotrypsin enzymes of the fish fed experimental diets. A lower final weight and a lower condition factor were found in fish fed diets RBPC10 (100 g/kg of RBPC) and RBPC15 (150 g/kg of RBPC). Based on the results of this study, it is clear that the use of RBPC (at high dietary inclusion levels of 200 and 300 g kg?1) is an effective alternative protein source to fishmeal. 相似文献
146.
Leila Maria Costamilan Cláudia Cristina Clebsch Rafael Moreira Soares Claudine Dinali Santos Seixas Cláudia Vieira Godoy Anne Elizabeth Dorrance 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(4):845-853
Phytophthora root and stem rot has developed in commercial soybean fields since 2006 in Brazil, and cultivars with resistance to this disease have not been targeted for this region. Thus, the Phytophthora sojae pathotypes are expected to have virulence to few if any of the Rps genes. The objectives of this study were to characterize the pathotype diversity of P. sojae in Brazil, determine the distribution of the pathogen and predict which Rps genes will be effective and should be used in breeding programs. Isolates were collected in six states (Rio Grande do Sul, Santa Catarina, Paraná, Mato Grosso do Sul, Minas Gerais, and Goiás). The virulence formulae were based on the response of a differential set with 14 Rps genes (1a, 1b, 1c, 1d, 1k, 2, 3a, 3b, 3c, 4, 5, 6, 7, and 8). None of the 17 pathotypes found was reported previously. The most common virulence formulas were: 1d, 2, 3c, 4, 5, 6, 7 (octal code 05471, representing 24 % of the occurrences); 1d, 2, 3b, 3c, 4, 5, 6, 7 (05671, 13 %); 1b, 1d, 2, 3a, 3c, 4, 5, 6, 7 (25571, 8 %); and 1d, 3a, 5, 7, 8 (01123, 8 %). Percentages of isolates with a susceptible interaction with each Rps gene was Rps1a (3 %), Rps1b (11 %), Rps1c (3 %), Rps1d (100 %), Rps1k (3 %), Rps2 (86 %), Rps3a (32 %), Rps3b (19 %), Rps3c (73 %), Rps4 (70 %), Rps5 (89 %), Rps6 (59 %), Rps7 (100 %), and Rps8 (22 %). There was apparently no relationship between pathotypes and origin. Stacking resistance genes Rps1a, Rps1b, Rps1c, and Rps1k with Rps3b or Rps8 would be highly effective for soybean cultivars targeted for Brazil. 相似文献
147.
Leila Eshraghi Nader Aryamanesh Jonathan P. Anderson Bryan Shearer Jen A. McComb Giles E. St. J. Hardy Philip A. O’Brien 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):419-430
A reliable method for measuring disease progression is important when evaluating susceptibility in host—pathogen interactions.
We describe a sensitive quantitative polymerase chain reaction (QPCR) assay that enables quantitative measurement of in planta DNA of the necrotrophic pathogen, Phytophthora cinnamomi, that avoids problems caused by variation in DNA extraction efficiency and degradation of host DNA during host tissue necrosis.
Normalization of pathogen DNA to sample fresh weight or host DNA in samples with varying degrees of necrosis led to overestimation
of pathogen biomass. Purified plasmid DNA, containing the pScFvB1 mouse gene, was added during DNA extraction and pathogen
biomass was normalized based on plasmid DNA rather than host DNA or sample fresh weight. This method is robust and improves
the accuracy of pathogen measurement in both resistant (non-host A. thaliana–P. cinnamomi) and susceptible (host Lupinus angustifolius–P. cinnamomi) interactions to allow accurate measurement of pathogen biomass even in the presence of substantial host cell necrosis. 相似文献
148.
Mohamed Boussaid Leila Ait Abderrahim Amel Ennajah 《Arid Land Research and Management》2018,32(2):184-197
The xerophytic shrub Ziziphus lotus (L) Lam may constitute the best choice as a fruit crop in arid regions and seems to have a great importance in uncultured and marginal soils. As the first report, this study investigates the genetic diversity among and within nine natural populations of Z. lotus encompassing wide range of ecological conditions in Algeria through analyses of fruits characteristics. Results reveal significant differences of fruit traits among and within populations; the morphological variability was significantly correlated with the variation of ecological conditions. In general, fruits color ranges from light to dark brown with mostly oval-shaped endocarps containing one or two seeds. In addition, fruits weight ranged between 0.43 and 0.75?g while length was comprised between 10 and 13?mm and fruit thickness varied between 9.85 and 12.81?mm. Overall, quantitative traits were significantly influenced by the environmental conditions, whereas qualitative traits were not clearly affected. Hence, three phenotypes were distinguished allowing detection of a gradual phenotypic variation following latitudinal gradient related mainly to aridity and sand content in the soil. Such variation offers a good basis for breeding objectives, principally for food and medicine objectives along with wide adaptations for various range of climate and soil. Management and conservation of Z. lotus germplasm in Algeria is highly recommended. 相似文献
149.
150.
Sibitz C Rudnay EC Wabnegger L Spergser J Apfalter P Nell B 《Veterinary ophthalmology》2011,14(Z1):67-74
Objective To determine the presence of chlamydial species including recently described chlamydial agents as well as the human pathogen Chlamydophila pneumoniae in feline conjunctivitis. Animal studied Twenty five cats without and 49 cats with conjunctivitis were tested for chlamydia using a Chlamydiaceae real time (RT) PCR (targeting the 23S rRNA gene sequence), a Chlamydiales PCR (targeting the 16S rRNA gene sequence), and cell culture. The PCR products of all positive samples were sequenced and subsequently analyzed using a basic local alignment search tool search. Results Chlamydiaceae RT PCR and subsequent sequence analyses identified C. pneumoniae in five cats in the conjunctivitis group. The presence of Chlamydophila felis was shown in two cats with conjunctivitis. Chlamydiae related to uncultured members of Chlamydiales were detected in three conjunctivitis cases and in one cat without clinical symptoms. Conclusion This study detects for the first time, the known human pathogen C. pneumoniae in feline conjunctivitis cases using Chlamydiaceae RT PCR and sequence analyses. 相似文献