全文获取类型
收费全文 | 432篇 |
免费 | 30篇 |
专业分类
林业 | 44篇 |
农学 | 29篇 |
基础科学 | 10篇 |
71篇 | |
综合类 | 14篇 |
农作物 | 20篇 |
水产渔业 | 81篇 |
畜牧兽医 | 119篇 |
园艺 | 18篇 |
植物保护 | 56篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 24篇 |
2020年 | 21篇 |
2019年 | 29篇 |
2018年 | 22篇 |
2017年 | 23篇 |
2016年 | 22篇 |
2015年 | 16篇 |
2014年 | 20篇 |
2013年 | 24篇 |
2012年 | 29篇 |
2011年 | 33篇 |
2010年 | 23篇 |
2009年 | 17篇 |
2008年 | 32篇 |
2007年 | 22篇 |
2006年 | 17篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有462条查询结果,搜索用时 15 毫秒
61.
Triploid Induction in the Yellowtail Tetra,Astyanax altiparanae,Using Temperature Shock: Tools for Conservation and Aquaculture
下载免费PDF全文
![点击此处可从《Journal of the World Aquaculture Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Nadya Soares de Macedo Adamov Nivaldo Ferreira do Nascimento Elayna Cristina Silva Maciel Matheus Pereira‐Santos José Augusto Senhorini Leonardo Luiz Calado Mariana Machado Evangelista Laura Satiko Okada Nakaghi Alan Hertz Marín Guerrero Takafumi Fujimoto George Shigueki Yasui 《Journal of the World Aquaculture Society》2017,48(5):741-750
Triploidization is an interesting tool to produce sterile fish. In the yellowtail tetra, Astyanax altiparanae, this can be applied for aquaculture and surrogate technologies. In this study, we compared the efficacy of cold (2 C) or heat shock (38 C, 40 C, and 42 C) on triploid induction in the yellowtail tetra. The eggs were treated with cold or heat shock, 2 min postfertilization (30 min in cold shock or 2 min in heat shock). Intact embryos served as the control group. Ploidy status was confirmed by karyotyping, flow cytometry, and nuclear diameter of erythrocytes. The hatching rate decreased after cold shock (12.69 ± 15.76%) and heat shock at 42 C (0.35 ± 0.69%) in comparison with the control group (63.19 ± 16.82%). At 38 C and 40 C, hatching rates (61.29 ± 17.73% and 61.75 ± 22.1%, respectively) were not decreased. Only one triploid arose at 38 C (1/80). At 40 C, a high number of triploids arose (72/78). At 42 C, very few embryos developed into the hatching stage. A large number of haploid individuals arose after cold shock (61/75), with only one triploid. Our results indicate that heat shocking of embryos at 40 C is optimum for triploid production in the yellowtail tetra. 相似文献
62.
Zanetti S Bua A Molicotti P Delogu G Mura A Ortu S Sechi LA 《Acta veterinaria Hungarica》2008,56(2):145-152
During a six-month period a region of Northern Sardinia was monitored to check the presence of mycobacterial infections in wild boars. Forty-eight serum and 229 biopsy samples were collected from different animals and examined by both traditional diagnostic techniques (culture, bacterioscopic and molecular tests) and enzyme-linked immunosorbent assay (ELISA). The latter was used to determine the antibody response against both methylated and nonmethylated Heparin-Binding Haemagglutinin (HBHA) protein. Nine mycobacterial strains were isolated: three M. avium ssp. paratuberculosis (Map), three M. avium, one M. interjectum and two M. scrofulaceum strains. By PCR, only one animal was positive for M. bovis, whereas 10 animals were positive for Map. Out of the 48 sera tested, 19 showed a good humoral response to methylated HBHA and 17 to nonmethylated HBHA. Our data provide new information on the prevalence of mycobacterial infection among wild boars in Northern Sardinia and suggest that a more effective program should be developed to monitor mycobacterial infections in the wild animal population. 相似文献
63.
64.
Valares JA Abecia JA Forcada F Palacín I Mata L Razquin P 《Veterinary research communications》2007,31(4):427-436
The present study describes the development and validation of a simple sensitive and specific sandwich enzyme immunoassay
(EIA) for the quantification of ovine luteinizing hormone (LH) in plasma. Microtitre plates were coated with the capture antibody
518b7 anti-bovine LH. A second peroxidase-labelled anti-ovine LH antibody was used as tracer. A simple 3-step procedure was
used for the sample analysis; (1) incubation of standards and samples with the pre-coated antibody plates for 2 h at 37°C; (2) incubation with the peroxidase-labelled antibody for 1 h at room temperature; and (3) colour development with TMB substrate.
A linear dose–response curve was obtained in the range 0–10 ng/ml (r
2 > 0.99). The detection limit was 0.05 ng/ml, and the intra-assay and inter-assay coefficients of variation were 7% and 11.7%,
respectively. The theoretical stability of microplates and reagents was calculated, this being greater than one year. Low
or undetectable cross-reactivities were recorded for follicle-stimulating hormone, bovine thyroid-stimulating hormone, equine
chorionic gonadotrophin and a gonadotrophin-releasing hormone (GnRH) analogue. The EIA was biologically validated by the determination
of plasma LH concentrations of nine Rasa Aragonesa ovariectomized and estradiol-implanted ewes after a double GnRH challenge.
In conclusion, this enzyme immunoassay provides an efficient, simple and sensitive method for the routine analysis of ovine
LH. 相似文献
65.
A total of six Ethiopian mustard ( Brassica carinata A. Braun) lines showing reduced levels of total glucosinolate content
were developed through two different approaches. In the first case, eight lines with good agronomic performance under southern-Spanish
conditions were first evaluated during two years for glucosinolate content, and a pedigree selection was then performed during
three further generations. The line N2-142, with an average glucosinolate content of 82 μmoles g-1 seed, was developed from
the original line C-49, with an average glucosinolate content of 115 μmoles g-1 seed. In the second case, chemical mutagenesis
(EMS 1% v/v) was applied to seeds from the line C- 101, with an average glucosinolate content of 125 μmoles g- 1 seed. Five
mutant lines showing an average glucosinolate content between 20 and 30 μmoles g-1 seed lower than the wild line C-101 were
isolated in the M_3 or M_4 generation. The reduced glucosinolate content of these mutants was confirmed by developing and
analysing the M_5 generation. Previous results in B. juncea suggest that a further reduction of total glucosinolate content
might be achieved through genetic recombination between the different lines developed in this work.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
66.
Juan Pablo Hualde Walter Damián Ceferino Torres Pablo Moreno Mirna Ferrada Mariela Ana Demicheli Leonardo Javier Molinari Carlos Marcelo Luquet 《Aquaculture Research》2011,42(6):754-763
An experiment was performed to evaluate the performance of Patagonian pejerrey during net cage rearing in the oligomesotrophic reservoir Exequiel Ramos Mexía. Survival, growth, nutrition and reproduction were evaluated for two lots of pejerrey, initial weights 4.0 and 2.5 g, reared in net cages for 22 and 14 months respectively. Fish were stocked at 29 and 48 individuals m?3 densities and fed with an experimental pejerrey feed. During the experiment, temperature fluctuated between 6.6 and 19.6 °C. The two lots did not show substantial differences in survival (pooled survival at the end of the experiment >80%) and the thermal‐unit growth coefficient (TGC), daily feed intake and feeding efficiency were 0.43±0.19, 1.70±0.80 and 53.6±9.9 respectively. Digestive tract analysis showed that caged pejerrey can consume substantial quantities of natural food, taking advantage of its planktivorous condition. Pejerrey showed high percentage survival, slow growth and early sexual maturation in captivity. The use of the TGC is proposed as a model for describing the growth pattern of this species and other pejerrey under culture conditions. 相似文献
67.
Significant improvement of shrimp growth performance by growth hormone‐releasing peptide‐6 immersion treatments
下载免费PDF全文
![点击此处可从《Aquaculture Research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amílcar Arenal Juana María Lugo Reynold Morales Leonardo Martín Ramón Franco Rodríguez Jannel Acosta Antonio Morales Jorge Duconge Mario Pablo Estrada 《Aquaculture Research》2017,48(9):4632-4645
Growth hormone‐releasing peptide‐6 (GHRP‐6) is one of the earliest developed synthetic peptidyl growth hormone secretagogue receptor agonists. These compounds mimic the effect of the endogenous ligand ghrelin. In vertebrates, ghrelin is a potent circulating orexigenic hormone with functional roles in controlling food intake, energy expenditure, adiposity, growth hormone secretion and immunity. Ghrelin has been studied mainly in vertebrates; thus, little is known about its role in invertebrates, including crustaceans. We first evaluated the effect of GHRP‐6 injection over feed intake in shrimp and its effects on shrimp growth when the peptide was administrated by successive immersion baths. GHRP‐6 increased feed intake, body weight and size, the number of rostral spines and gill branches, protein concentration and haemocyte number in treated shrimps. We also evaluated the peptide uptake and clearance in a pharmacokinetics, using [H3]GHRP‐6 administered to postlarvae. Given a limited exposure and efficient clearance of the peptide‐associated radioactivity from larvae, our findings suggested that GHRP‐6‐treated Litopenaeus vannamei can be consumed safely by humans after aquaculture applications. These results propose that GHRP‐6 could be an additional tool to study growth physiology in crustaceans and also a promising candidate for development into a new biotechnology product for improving shrimp growth and quality. 相似文献
68.
Omar Aguilln Jos Antonio Mata Louis R. DAbramo María Teresa Viana 《Aquaculture Nutrition》2020,26(5):1463-1475
The involvement of dietary methionine in the lipid metabolism of Seriola dorsalis, at different levels of dietary methionine (Met), and low content of cholesterol was investigated. Four diets containing different Met levels and a low amount of cholesterol (0.23 g/kg diet) were prepared. One hundred and eighty juveniles (16.2 ± 1.5 g) were randomly distributed into each 12 500‐L ponds. After 60 days, the growth in weight (%) significantly increased following the Met supplementation, whereas SGR of all the experimental treatments was higher than the Basal Diet. The expression of the insulin‐like growth factor (IGF‐1) increased significantly (0.2‐fold) and was complemented by significant changes in Mat, BHMT and HMG‐CoA, for fish that were in the low and higher Met levels. The cholesterol content in the whole body and liver increased following methionine supplementation, similarly to that observed for crude lipids, in particular in the whole body and liver tissues. However, the relative amount of most fatty acids remained unchanged. Only the oleic acid increased at a higher amount of Met. Therefore, once the dietary requirement of methionine is met, the methionine is used to synthesize cholesterol. It is recommended to supply a higher amount of methionine to spare energy for growth. 相似文献
69.
Jacquetta Udy Stephen Wing Sorrel O'Connell‐Milne Stina Kolodzey Rebecca McMullin Leonardo Durante Russell Frew 《水产资源保护:海洋与淡水生态系统》2019,29(9):1503-1519
- 相似文献
70.
Javier Prez‐Robles Ana Denisse Re‐Araujo Maricela Cortez‐García Fernando Díaz Leonardo Ibarra‐Castro Ivone Giffard‐Mena 《Aquaculture Research》2019,50(1):198-208
Euryhaline fish, such as the Bullseye puffer Sphoeroides annulatus (Jenyns 1842), experience sudden salinity changes in their natural environment, which is more common than the exception, so they must adapt to survive and cope with extreme salt conditions. Therefore, Bullseye puffer juveniles were exposed to short‐term stress (39 hr) by fluctuating salinity conditions (41, 35, 29, 23, 17, 11, 5, 11, 17, 23, 29, 35, 41 psu) with a 3‐hr interval between each point at 26 ± 1ºC in a respirometer chamber and acclimation reservoirs. Responses to oxygen consumption rate (OCR: 23–35 mg O2 h–1 kg–1), ammonium excretion rate (AER: 1–1.85 mg NH4+ h?1 kg?1), oxygen‐nitrogen atomic ratio (O:N 17–30), osmoregulatory pattern (blood osmotic pressure from 342.4 to 332.8 mmol/kg) and changes in expression levels of Na+/K+‐ATPase in the gills (higher values at higher salinities) were measured. Although some signs of stress were detected below the iso‐osmotic point (11.4 psu), the puffer fish is a strong euryhaline fish that survives under these conditions. Nonetheless, it could recover when salinity returned to the initial acclimation point because Sphoeroides annulatus is able to live in a wide range of environments with wide natural salinity fluctuations; thus, a common practice in aquaculture has been to expose fish to low salinity for several reasons discussed in this study. This capacity reveals its high plasticity to saline adaptation from 41 to 5 psu an up from 5 to 41 psu, all in less than 2 days. 相似文献