全文获取类型
收费全文 | 208篇 |
免费 | 10篇 |
专业分类
林业 | 5篇 |
农学 | 10篇 |
96篇 | |
综合类 | 20篇 |
农作物 | 4篇 |
水产渔业 | 7篇 |
畜牧兽医 | 50篇 |
园艺 | 7篇 |
植物保护 | 19篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 5篇 |
2005年 | 9篇 |
2004年 | 14篇 |
2003年 | 7篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1964年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有218条查询结果,搜索用时 312 毫秒
51.
Esterina Fazio Pietro Medica Vincenzo Aronica Loredana Grasso Adriana Ferlazzo 《Acta veterinaria Scandinavica》2008,50(1):6
Background
Since transport evokes physiological adjustments that include endocrine responses, the objective of this study was to examine the responses of circulating β-endorphin, adrenocorticotrophic hormone (ACTH) and cortisol levels to transport stress in stallions.Methods
Forty-two healthy Thoroughbred and crossbred stallions were studied before and after road transport over distances of 100, 200 and 300 km. Blood samples were collected from the jugular vein: first in a single box immediately before loading (pre-samples), then immediately after transport and unloading on arrival at the breeding stations (post-samples).Results
An increase in circulating β-endorphin levels after transport of 100 km (P < 0.01), compared to basal values was observed. Circulating ACTH levels showed significant increases after transport of 100 km (P < 0.001) and 200 km (P < 0.001). Circulating cortisol levels showed significant increases after road transport over distances of 100, 200 and 300 km (P < 0.001). An effect of transport on β-endorphin, ACTH and cortisol variations was therefore evident for the different distances studied. No significant differences (P > 0.05) between horses of different ages and different breeds were observed for β-endorphin, ACTH and cortisol levels.Conclusion
The results obtained for short term transportation of stallions showed a very strong reaction of the adrenocortical system. The lack of response of β-endorphin after transport of 200–300 km and of ACTH after transport of 300 km seems to suggest a soothing effect of negative feedback of ACTH and cortisol levels. 相似文献52.
Romano Dallai Vittoria Cavallo Luigi Federico Falso Pietro Paolo Fanciulli 《Pedobiologia》2000,44(3-4)
The fine structure of the male reproductive system of Allacma fusca (L.) is described. The system consists of testes, deferent ducts, seminal vesicles, ejaculatory duct and accessory glands. The nature of each part is established. Secretions from the seminal vesicles are stored in the lumen of these organs, then flow into the ejaculatory duct and are used to produce spermatophores. The epithelium of this tract has secretory activity and osmoregulatory function. Secretions and spermatozoa are stored into two distinct parts of the ejaculatory duct, divided by a transverse cuticular septum. 相似文献
53.
Jaime Prohens Pietro Gramazio Mariola Plazas Hannes Dempewolf Benjamin Kilian María J. Díez Ana Fita Francisco J. Herraiz Adrián Rodríguez-Burruezo Salvador Soler Sandra Knapp Santiago Vilanova 《Euphytica》2017,213(7):158
The need to boost agricultural production in the coming decades in a climate change scenario requires new approaches for the development of new crop varieties that are more resilient and more efficient in the use of resources. Crop wild relatives (CWRs) are a source of variation for many traits of interest in breeding, in particular tolerance to abiotic and biotic stresses. However, their potential in plant breeding has largely remained unexploited. CWRs can make an effective contribution to broadening the genetic base of crops and to introgressing traits of interest, but their direct use by breeders in breeding programs is usually not feasible due to the presence of undesirable traits in CWRs (linkage drag) and frequent breeding barriers with the crop. Here we call for a new approach, which we tentatively call ‘introgressiomics’, which consists of mass scale development of plant materials and populations with introgressions from CWRs into the genetic background of crops. Introgressiomics is a form of pre-emptive breeding and can be focused, when looking for specific phenotypes, or un-focused, when it is aimed at creating highly diverse introgressed populations. Exploring germplasm collections and identifying adequate species and accessions from different genepools encompassing a high diversity, using different strategies like the creation of germplasm diversity sets, Focused identification of germplasm strategy (FIGS) or gap analysis, is a first step in introgressiomics. Interspecific hybridization and backcrossing is often a major barrier for introgressiomics, but a number of techniques can be used to potentially overcome these and produce introgression populations. The generation of chromosome substitution lines (CSLs), introgression lines (ILs), or multi-parent advanced inter-cross (MAGIC) populations by means of marker-assisted selection allows not only the genetic analysis of traits present in CWRs, but also developing genetically characterized elite materials that can be easily incorporated in breeding programs. Genomic tools, in particular high-throughput molecular markers, facilitate the characterization and development of introgressiomics populations, while new plant breeding techniques (NPBTs) can enhance the introgression and use of genes from CWRs in the genetic background of crops. An efficient use of introgressiomics populations requires moving the materials into breeding pipelines. In this respect public–private partnerships (PPPs) can contribute to an increased use of introgressed materials by breeders. We hope that the introgressiomics approach will contribute to the development of a new generation of cultivars with dramatically improved yield and performance that may allow coping with the environmental changes caused by climate change while at the same time contributing to a more efficient and sustainable agriculture. 相似文献
54.
55.
Esterina Fazio Pietro MedicaCristina Cravana DVM PhD Piergiorgio MolinariAdriana Ferlazzo BSc MSc PhD 《Journal of Equine Veterinary Science》2014
Gymkhana is an equestrian event consisting of speed pattern racing and timed games for riders on horses. The aim of the study was to evaluate the effects of gymkhana competition on total cortisol and total and free iodothyronine changes in 23 Arabian purebred horses, by taking into account the effects of previous sport experience on gymkhana riding events. Compared with pre-competition values, an increase of total cortisol concentration has been observed in experienced horses at 30 minutes (P < .001) after exercise and in inexperienced horses both at 5 minutes (P < .05) and at 30 minutes (P < .01) after exercise. Compared with pre-competition values, an increase of total triiodothyronine (T3) concentration has been observed in experienced horses at 5 minutes (P < .05) after exercise. Data obtained showed that gymkhana riding events induced differential adrenocortical and thyroid responsiveness according to previous experience of sport horses. Hence, cortisol and iodothyronine patterns may provide additional information for the monitoring of gymkhana riding performance. 相似文献
56.
Valente EM Abou-Sleiman PM Caputo V Muqit MM Harvey K Gispert S Ali Z Del Turco D Bentivoglio AR Healy DG Albanese A Nussbaum R González-Maldonado R Deller T Salvi S Cortelli P Gilks WP Latchman DS Harvey RJ Dallapiccola B Auburger G Wood NW 《Science (New York, N.Y.)》2004,304(5674):1158-1160
Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra. We previously mapped a locus for a rare familial form of PD to chromosome 1p36 (PARK6). Here we show that mutations in PINK1 (PTEN-induced kinase 1) are associated with PARK6. We have identified two homozygous mutations affecting the PINK1 kinase domain in three consanguineous PARK6 families: a truncating nonsense mutation and a missense mutation at a highly conserved amino acid. Cell culture studies suggest that PINK1 is mitochondrially located and may exert a protective effect on the cell that is abrogated by the mutations, resulting in increased susceptibility to cellular stress. These data provide a direct molecular link between mitochondria and the pathogenesis of PD. 相似文献
57.
Lee E Marcucci M Daniell L Pypaert M Weisz OA Ochoa GC Farsad K Wenk MR De Camilli P 《Science (New York, N.Y.)》2002,297(5584):1193-1196
In striated muscle, the plasma membrane forms tubular invaginations (transverse tubules or T-tubules) that function in depolarization-contraction coupling. Caveolin-3 and amphiphysin were implicated in their biogenesis. Amphiphysin isoforms have a putative role in membrane deformation at endocytic sites. An isoform of amphiphysin 2 concentrated at T-tubules induced tubular plasma membrane invaginations when expressed in nonmuscle cells. This property required exon 10, a phosphoinositide-binding module. In developing myotubes, amphiphysin 2 and caveolin-3 segregated in tubular and vesicular portions of the T-tubule system, respectively. These findings support a role of the bilayer-deforming properties of amphiphysin at T-tubules and, more generally, a physiological role of amphiphysin in membrane deformation. 相似文献
58.
Nadia Musco Valeria Maria Morittu Vincenzo Mastellone Anna Antonella Spina Giuseppe Vassalotti Biagio D’Aniello Raffaella Tudisco Federico Infascelli Pietro Lombardi 《Journal of animal physiology and animal nutrition》2021,105(Z1):26-33
A nutritional supplement (Ecotrofin™, by Vetoquinol Italia S.r.l) recommended in ruminants feeding to strengthen the physiological condition and improve digestive performance was tested in 20 pluriparae grazing goats divided in two groups (control and treated) to assess its possible effects on milk yield and quality and to assess eventual adverse effects. Animals from both groups also received 400 g/day of corn meal, and the treated group was supplemented with 20 g/head/day of the nutritional supplement. At the doses suggested by the manufacturer, despite a transient increase after 30 days of supplementation, Ecotrofin™ did not show significant effects on milk yield and, although some changes were found in the fatty acids profile, no significant improvement of MUFA and PUFA, as well as of omega-6:omega-3 ratio and CLA content were seen. Therefore, in our experimental conditions the supplementation of diet with Ecotrofin™ did not appear useful to improve goat's performance. A significant effect on kidney health markers (27 vs. 22.5 for urea and 0.83 vs. 0.76 for creatinine, p < 0.05) suggested a beneficial effect on renal function but, since levels fell in the normal ranges in both groups, such hypothesis would need further studies to be addressed. 相似文献
59.
Renan B. Paiano Jeannine Bonilla Andrea M. Moreno Pietro S. Baruselli 《Reproduction in domestic animals》2021,56(12):1536-1542
The aim of this study was to identify the impact of Trueperella pyogenes in cows with clinical endometritis (CE) on reproductive performance and milk production in affected cows. In total, 230 lactating Holstein dairy cows from six commercial dairy herds were sampled once between 28 and 33 days post-partum. Cows included in the present study did not receive antibiotic or anti-inflammatory treatments prior to the experimental period. Clinical endometritis (CE) was characterized as cow with vaginal mucus score = 3 (>50% of purulent vaginal discharge) and >18% polymorphonuclear neutrophilic leukocyte (PMNL). The body condition scores (BCS) and milk production were evaluated at the time of enrolment. The identification of isolated bacteria was carried out through the analysis of MALDI-TOF MS (matrix-assisted laser desorption ionization time-of-flight mass spectrometry). According to uterine health, three groups of dairy cows were formed: healthy control cows without T. pyogenes (n = 147), CE cows with T. pyogenes (n = 22) and CE cows without T. pyogenes (n = 61). CE cows with T. pyogenes had lower BCS, milk production and conception at first AI (p < .01) than CE cows without T. pyogenes and control cows. Furthermore, CE cows with T. pyogenes had higher (p < .01) service per pregnancy and had greater (p < .01) days to get pregnant than CE cows without T. pyogenes and control cows. This study demonstrates that CE cows with T. pyogenes had impaired reproductive performance and milk production when compared to cows without CE and CE cows without T. pyogenes. This information can contribute to a strategic treatment in cows affected by clinical endometritis, favouring the rational use of antibiotics on dairy farms. 相似文献
60.
Enrico Bottero Emanuele Mussi Fabiano Raponi Davide De Lorenzi Pietro Ruggiero 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(7):736
This study describes the clinical, diagnostic, and pathological characteristics of canine nasal polyps and how they responded to medical, endoscopic, and surgical treatments. The database of a multi-center veterinary endoscopy group was searched from 2010 to 2018. All dogs with a histological diagnosis of nasal polyposis that were undergoing endoscopic investigation (N = 23), were included. Clinical signs at presentation were sneezing (91%), nasal discharge (83%), stertor (74%), and frontonasal deformation (17%). Skull radiography on 13 dogs had alterations in 77% of cases, including turbinate lysis (6/13), increased radiopacity of one (4/13) or both (6/13) nasal cavities, and lysis of the nasal vomer bone (3/13). Nasal polyposis had a characteristic endoscopic appearance. There were clinical and diagnostic similarities between this cohort of dogs and dogs with nasal neoplasia, although dogs with nasal polyps were often younger and polypoid tissue was external to the nose. Steroid therapy alone was not effective in treating polyposis in dogs; however, endoscopic debulking with a laser and forceps was more effective. 相似文献