全文获取类型
收费全文 | 108篇 |
免费 | 1篇 |
专业分类
林业 | 6篇 |
农学 | 1篇 |
基础科学 | 1篇 |
46篇 | |
综合类 | 3篇 |
农作物 | 13篇 |
水产渔业 | 11篇 |
畜牧兽医 | 22篇 |
园艺 | 1篇 |
植物保护 | 5篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2013年 | 6篇 |
2012年 | 4篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 3篇 |
2008年 | 18篇 |
2007年 | 6篇 |
2006年 | 6篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 15 毫秒
1.
Youssef Rouphael Mariateresa Cardarelli Elena Di Mattia Monica Tullio Elvira Rea Giuseppe Colla 《Biology and Fertility of Soils》2010,46(5):499-509
The aim of the present study was to determine whether arbuscular mycorrhizal (AM) inoculation with a biofertilizer containing
clays as granular carriers, leek root pieces and Glomus intraradices spores could improve alkalinity tolerance of two cucumber genotypes, and to study the changes induced by AM at agronomical
and physiological level. A greenhouse experiment was carried out to determine yield, growth, fruit quality, net photosynthesis
(ACO2), electrolyte leakage, and mineral composition of two cucumber (Cucumis sativus L.) genotypes (hybrid “Ekron” or open-pollinated variety “Marketmore”) with inoculated and noninoculated arbuscular mycorrhizal
biofertilizer. Plants were supplied with nutrient solutions at two pH values (6.0 or 8.1). The high pH nutrient solution had
the same basic composition with an additional 10 mM NaHCO3 and 0.5 g l−1 CaCO3. The percentage root colonization was higher in “Marketmore” (21.8%) than “Ekron” (12.7%). Total and marketable yield and
total biomass were significantly higher by 189%, 213%, and 77%, respectively, with Ekron in comparison to those recorded with
Marketmore. The highest crop performance with Ekron in comparison to Marketmore was due to the improved nutritional status
(higher N, P, K, Ca, Mg, Fe, Mn, and B), higher leaf area, and net photosynthesis. Increasing the concentration of NaHCO3 from 0 to 10 mM in the nutrient solution significantly decreased yield, plant growth, ACO2, N, P, Fe, Cu, Zn, Mn, and B concentration in leaf tissue, whereas the electrolyte leakage increased. The inoculated plants
under alkaline conditions had higher total, marketable yield, and total biomass than noninoculated plant. Mycorrhizal cucumber
plants grown under alkaline conditions had a higher macronutrient concentration in leaf tissue compared to noninoculated plants.
The highest yield and biomass production in inoculated plants seems to be related to the capacity of maintaining higher net
ACO2 and to a better nutritional status (high P, K, Mg, Fe, Zn, and Mn and low Na accumulation) in response to bicarbonate stress
with respect to −AM plants. 相似文献
2.
3.
Monge A Elvira L Gonzalez JV Astiz S Wellenberg GJ 《Research in veterinary science》2006,80(1):120-125
In more than 10 Spanish dairy cows, a bovine herpesvirus 4 (BHV4) associated postpartum metritis was confirmed by virus isolation, BHV4-glycoprotein B (gB) PCR and/or serology. In this study, 12 cows with, and, at the time of sampling, 3 cows without clinical signs of acute postpartum metritis from one large dairy herd in Spain were examined for bacterial and viral infections. Blood, placenta/caruncles and uterine contents were collected between day 1 and day 20 post-calving, and examined for the presence of bacteria and for viruses by virus isolation, BHV4 DNA by BHV4-gB PCR and/or BHV4 antibody titres. Bovine herpesvirus 4 was detected in 83% of the cases with clinical signs of acute postpartum metritis by virus isolation and/or BHV4-gB PCR. An increase of BHV4 antibodies was detected in all examined postpartum metritis cows and in the 3 cows without clinical metritis. Two of these 3 cows developed severe metritis a few dayss after collecting the first blood sample. A concurrent infections of BHV4 and bacteria, mainly Arcanobacterium pyogenes and Streptococcus sp., were detected in 73% of the examined uterine contents collected from postpartum metritis affected cows. This case-report study showed a clear association between BHV4 infections and acute postpartum metritis in dairy cows. In addition, the BHV4-associated postpartum metritis appeared to be an emerging syndrome in this Spanish herd. 相似文献
4.
Gimenez G Florin-Christensen M Belaunzarán ML Isola EL Suárez CE Florin-Christensen J 《Veterinary immunology and immunopathology》2007,119(3-4):171-179
Erythrocytes of bovines and other ruminants have a strikingly anomalous phospholipid composition, with low or absent phosphatidylcholine (PC) together with high sphingomyelin (SM) content. Here, we report the presence in normal bovine serum of high levels of anti-phospholipid antibodies of IgM isotype against, PC and the phosphono analogue of phosphatidylethanolamine, aminoethylphosphonolipid (AEPL), normally produced by rumen ciliates. In contrast, no antibodies were detected against SM or N-acyl-phosphatidylethanolamine (NAPE), the major components of bovine erythrocytes. In addition, we found that exposure of the ciliate Tetrahymena thermophila to bovine serum results in rapid lysis, an effect that was inhibited by adsorption of the serum with SM/AEPL liposomes. Furthermore, incubation with bovine serum had a similar effect on freshly obtained ruminal ciliates, and the lytic activity was eliminated by pre-adsorption of the serum with SM/PE liposomes. The ruminant mode of life with its concomitant ciliate fauna is hereby linked to the peculiar conformation of bovine erythrocyte membranes. We propose that the unique phospholipid composition of bovine erythrocytes appears as an evolutionary adaptation to tolerate the lytic effects of anti-phospholipid antibodies generated against AEPL, a membrane component of the huge mass of ruminal ciliates, necessary commensals of this group of mammals. 相似文献
5.
Claude Plassard Julien Louche Muhammad A. Ali Myriam Duchemin Elvira Legname Benoît Cloutier-Hurteau 《Annals of Forest Science》2011,68(1):33-43
• Introduction
Phosphorus (P) is often the first or second element limiting aboveground net primary productivity of forests. Besides low available inorganic orthophosphate (Pi) concentrations, soil may contain high total P contents, as insoluble mineral P or as organic P. Most plants form mycorrhizal associations that improve their P nutrition. Three main hypotheses have been proposed to explain this positive effect through an increase of (1) P mobilisation from mineral P, (2) P mobilisation from organic P and (3) soil exploration and P uptake. However, the positive effect of mycorrhizal symbiosis may be variable with the fungal species forming the association. This could be due to the different abilities of mycorrhizal fungi to mobilise P and/or to take up Pi from the soil. 相似文献6.
The most variable region of the cytochrome oxidase I (COI) gene of Hypoderma bovis(1) and Hypoderma lineatum(2) (Diptera, Oestridae) was amplified by PCR and the amplicons were sequenced and analysed. PCR products were digested with three restriction enzymes, namely BfaI, HinfI and TaqI, providing informative profiles. H. bovis and H. lineatum sequences revealed an inter-specific variation rate of 8.5%, and an intra-specific variation rate of 0.87 and 0.29%, respectively. The results showed that the COI gene region examined was useful for the differentiation of H. bovis and H. lineatum and that a PCR-RFLP assay is a practical tool for their identification, offering additional diagnostic and epidemiological instruments for the study of cattle grub infestation. 相似文献
7.
Aparicio-Fernández X Reynoso-Camacho R Castaño-Tostado E García-Gasca T González de Mejía E Guzmán-Maldonado SH Elizondo G Yousef GG Lila MA Loarca-Pina G 《Plant foods for human nutrition (Dordrecht, Netherlands)》2008,63(1):35-40
Jamapa bean is a black Phaseolus vulgaris variety rich in condensed tannins, anthocyanins and flavonols with interesting biological activities. The objective of this
work was to evaluate the antiradical capacity (ARC) of a Jamapa bean methanolic extract (BME) and some of the proanthocyanidin-rich
fractions derived from it, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The effect of the BME on some proteins involved
in apoptosis on HeLa cells was also evaluated. A strong correlation between proanthocyanidin concentration in BME and antiradical
capacity was found, suggesting that these compounds contribute significantly to antiradical activity. BME was a better radical
scavenger than butylated hydroxytoluene (45.6 and 33.9% ARC at 400 μM, respectively). Two proanthocyanidin-rich fractions
obtained after a preliminary separation of the BME using Toyopearl (TP4 and TP6) exhibited a higher antiradical activity than
the parent extract. The treatment of HeLa cells with 35 μg BME/ml/24 h increased the expression of Bax and Caspase-3, pro-apoptotic
proteins (6.13 and 1.2 times for Caspase-3 and Bax, respectively). The mechanism of action of some proteins involved in apoptosis
was also evaluated, and the results suggest that black Jamapa bean could be an important source of polyphenolic compounds
with potential biological use as antioxidant and anticancer agents. 相似文献
8.
Castro-Hermida JA Pors I Otero-Espinar F Luzardo-Alvarez A Ares-Mazás E Chartier C 《Veterinary parasitology》2004,120(1-2):35-41
The efficacy of orally administered tablets containing alpha-cyclodextrin, an excipient used in the pharmaceutical industry with demonstrated anticryptosporidial activity in vitro and in neonatal mice, was evaluated in neonatal goat kids. The formulation was evaluated for hardness and was subjected to in vitro drug release studies. Twenty goat kids were orally inoculated with 10(6) oocysts of C. parvum within the first 6 days of age. Half of the animals were treated by oral administration of four tablets of alpha-cyclodextrin/day (500 mg/kg of body weight) for six consecutive days, the treatment beginning on the day of inoculation. Infection was monitored by daily examination of faecal samples from the first day to 25 days post-inoculation. The criteria studied in evaluating efficacy were: oocyst shedding, presence of diarrhoea and weight gain at 15 and 25 days post-inoculation. alpha-cyclodextrin was effective when given at the beginning of infection: there was a longer pre-patent period, a reduction in the patent period and a decrease in the intensity of infection, these differences being statistically significant (P < 0.05) compared with untreated neonatal kids. Moreover, except in one animal, the diarrhoea was prevented in infected neonatal kids. Animals from both groups increased the body weight and no significant differences were seen between the two groups. 相似文献
9.
Aparicio-Fernández X García-Gasca T Yousef GG Lila MA González de Mejia E Loarca-Pina G 《Journal of agricultural and food chemistry》2006,54(6):2116-2122
The antiproliferative effects of 100% methanol crude extract and of Toyopearl and silica gel fractions from the seed coats of black Jamapa beans (Phaseolus vulgaris L.) were evaluated using HeLa, human adenocarcinoma cells, and HaCaT, human premalignant keratinocytes. The 100% methanol crude extract [172.2 microM equiv of (+)-catechin] increased adhesion of HeLa cells; however, 3- and 5-fold higher concentrations decreased the number of cells attached as a function of the treatment time. The highest concentration tested diminished the cell adhesion until 40% (after 24 h) to almost 80% (after 72 h). The IC50 values showed that the 100% methanol crude extract was the most effective inhibitor of HeLa cell proliferation, even when it was dissolved in dimethylsulfoxide (DMSO) [34.5 microM equiv of (+)-catechin] or in medium [97.7 microM equiv of (+)-catechin]. The Toyopearl 5 (TP5) fraction and silica gel 2 (SG2) fraction inhibited 60% of the HeLa cell proliferation. The IC50 was 154 microM equiv of (+)-catechin of the 100% methanol crude extract on HaCaT cells. Toyopearl fractions TP4 and TP6 significantly inhibited HaCaT cell proliferation, but the silica gel fractions did not have a significant effect. The 100% methanol crude extract (35 microg of dry material/mL) decreased the number of HeLa cells in the G0/G1 phase from 68.9% (for control cells) to 51.4% (for treated cells) and increased apoptosis (2.9 and 21.2% for control and treated cells, respectively). The results indicated that black Jamapa beans could be a source of polyphenolic compounds, which have an inhibitory effect toward HeLa cancer cells but are less aggressive on HaCaT premalignant cells. 相似文献
10.
Maria Isabel Ferraz de Oliveira Elsa Lamy Miguel N. Bugalho Margarida Vaz Cristina Pinheiro Manuel Cancela d’Abreu Fernando Capela e Silva Elvira Sales-Baptista 《Agroforestry Systems》2013,87(6):1421-1437
Montados are agro-silvo-pastoral ecosystems, typical of the Southwest Iberian Peninsula, of high socio-economic and conservation importance, where grazing is a dominant activity. Montados are characterized by an open tree canopy of Quercus sp. and a diverse undercover of shrubs and grasslands that constitute the plant food resources for grazing animals. Plant food resources of Montados are highly variable, both spatially and seasonally, in quantity and quality. Reliable and easy to use methods to monitor grazing are necessary to allow proper understanding of foraging strategies of grazing animals and to set sustainable grazing management. We describe the main characteristics of the plant food resources available for grazing animals, striking its variability, and revise the potential of using N-alkanes and saliva proteome methods to assess foraging strategies in Montados. In a scenario of dynamic multiple choices, we discuss the use of n-alkane methodology for the simultaneous estimation of diet composition and voluntary intake and saliva proteome as a mean of increasing the knowledge on diet adjustments. 相似文献