全文获取类型
收费全文 | 66篇 |
免费 | 4篇 |
专业分类
林业 | 4篇 |
农学 | 2篇 |
15篇 | |
综合类 | 2篇 |
农作物 | 3篇 |
水产渔业 | 3篇 |
畜牧兽医 | 31篇 |
植物保护 | 10篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 1篇 |
2012年 | 4篇 |
2011年 | 2篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有70条查询结果,搜索用时 718 毫秒
1.
José Luis Palomo María M. López Pablo García-Benavides Encarna Velázquez Eustoquio Martínez-Molina 《European journal of plant pathology / European Foundation for Plant Pathology》2006,115(4):443-451
API 50CH and API ZYM systems were used to characterize fifty-three strains of Clavibacter michiganensis subsp. sepedonicus from different geographic locations and several reference strains of the same and different species, including other potato pathogens. Clavibacter michiganensis subsp. sepedonicus strains displayed a high level of homogeneity, both in carbohydrate utilization and in enzymatic activity. Using API 50CH and API ZYM it was possible to differentiate C. michiganensis subsp. sepedonicus strains from the remaining taxa analysed in this study, which included representative strains of the other subspecies of C. michiganensis as well as other bacterial pathogens affecting potatoes. Therefore, these systems could be used as an effective method to characterize C. michiganensis subsp. sepedonicus. Such a procedure would constitute an alternative system to the conventional nutritional and physiological identification tests currently included in the official methods employed in the European Union to detect and identify this bacterium. The results obtained with the API systems agreed with the current taxonomic classification of C. michiganensis, clearly separating sepedonicus from the other subspecies belonging to this species. 相似文献
2.
I.E. Pérez-González M.G. Prado-Ochoa M.A. Muñoz-Guzmán V.H. Vázquez-Valadez A.M. Velázquez-Sánchez B.L. Avila-Suárez C. Cuenca-Verde E. Angeles F. Alba-Hurtado 《Veterinary parasitology》2014,199(3-4):235-241
The effects of six new synthetic carbamates on fully engorged females of four Rhipicephalus microplus strains (one reference strain susceptible to conventional ixodicides, two strains multiresistant to ixodicides and one tick field isolate) were compared. In addition, the effect of two other new synthetic carbamates was tested on larvae from the same strains. The first six tested carbamates reduced egg laying and inhibited egg hatching in the four studied strains (P < 0.05). Compared with untreated females, the eggs produced by the treated engorged female ticks of all strains had a dark, dry, opaque appearance and were less adherent. The remaining two tested carbamates induced larval mortality in all of the evaluated strains. The three studied R. microplus strains displayed 50% resistance ratios (RR50) of less than 2 when compared to the susceptible reference strain. These results demonstrate that both carbamates with a larvicidal effect and carbamates that inhibit egg laying and embryo development are efficacious against tick strains that are resistant to commercial ixodicides, no cross resistance was observed. 相似文献
3.
Dendrometric analysis of olive trees for wood biomass quantification in Mediterranean orchards 总被引:1,自引:0,他引:1
Borja Velázquez-Martí I. López Cortés D. M. Salazar-Hernández 《Agroforestry Systems》2014,88(5):755-765
This work focuses on the development of dendrometric algorithms to calculate the volume and total biomass contained in olive trees. This laid the foundation for the use of this methodology as a tool to manage resources from orchards, establishing adequate prediction models for assessing other parameters such as income from raw materials from the cultivation, fruit production, CO2 sinks, and waste materials (residual wood) used for energy or industry. Dendrometry has traditionally been applied to forest trees. However, little research has been conducted on fruit trees because of their heterogeneous structure. This issue was the first step of this research. For this, the form factors were calculated. This relates to the actual volume of the branch with a model volume, calculated as a revolution solid from the base diameter and length. The shape more approximated to 1 was the cylinder model with a mean value of 0.76 and standard deviation (SD) of 0.23. On the other hand, volume equations were obtained for the branches. The distribution of biomass in the tree was analyzed. It is estimated that 40 % of biomass is located in the stem and 60 % in the crown, and most of the crown biomass is concentrated in the first branches (60 %). Afterwards, occupation factors were calculated to relate the wood volume in the crown to its apparent volume, the mean being 0.005 dm3/m3 and SD 0.0025 dm3/m3. Also, equations for predicting the whole wood in the crown were obtained. In this regard, the best results were obtained when the crown diameter was used (R 2 = 0.74). These results could be correlated with the production and quality of the fruit, amount of residual biomass coming from pruning, and LIDAR data, which may indicate a simple, quick, and accurate method for predicting biomass. 相似文献
4.
Recombinant Bone Morphogenetic Proteins: Novel Substances for Enhancing Bone Healing 总被引:1,自引:0,他引:1
CARL A. KIRKER-HEAD MA Vel MB MRCVS Diplomate ACVS Diplomate ECVS 《Veterinary surgery : VS》1995,24(5):408-419
Bone morphogenetic proteins (BMPs) are differentiative factors whose principal function is to induce transformation of undifferentiated mesenchymal cells into chondroblasts and osteoblasts in a dose-dependent manner. Bone morphogenetic proteins have been isolated postnatally in mammals from bone matrix, periosteal cells, mesenchymal cells of marrow stroma, tooth anlagen, and cells of osteosarcoma and chondrosarcoma. Distribution in additional embryonic tissues implies a broader organogenic function. Bone morphogenetic proteins are the only differentiative factors able to singularly induce de novo bone formation in vitro and in vivo. Recombinant DNA technology allows their production in large and highly purified quantities. The BMPs' osteoinductive ability has been shown with a variety of carriers including collagens and polymers at heterotopic and orthotopic sites in a wide range of species. They are presently being readied for clinical use as alternatives to bone grafts. Other potential applications include use as pulp capping agents, promoters of implant osteointegration and soft tissue reunion with bone, treatments for nonadaptive bone disease, and implants for use with mitotically expanded skeletal stem cell populations. Errors in the genetic coding of BMPs may manifest as clinical disease entities. 相似文献
5.
Savlík M Polácková L Szotáková B Lamka J Velík J Skálová L 《Research in veterinary science》2007,83(1):20-26
Basal activities of certain pheasant hepatic and intestinal biotransformation enzymes and modulation of their activities by anthelmintics flubendazole (FLBZ) and mebendazole (MBZ) were investigated in subcellular fractions that were prepared from liver and small intestine of control and FLBZ or MBZ treated birds. Several oxidation, reduction and conjugation enzyme activities were assessed. In the liver, treatment of pheasants by FLBZ or MBZ caused very slight or no changes in monooxygenase activities and conjugation enzymes. More significative changes were detected in small intestine. Metyrapone and daunorubicin reductase activities were increased by both substances in the liver. This is the first evidence that certain benzimidazoles modulate reductases of carbonyl group. With respect to the relatively slight extent of the changes caused by FLBZ or MBZ we can assume that repeated administration of therapeutic doses of both FLBZ and MBZ has probably no serious influence on pheasant biotransformation enzyme system. 相似文献
6.
Avilla J Teixidò A Velázquez C Alvarenga N Ferro E Canela R 《Journal of agricultural and food chemistry》2000,48(1):88-92
The insecticidal effects of nortriterpene quinone methides (pristimerin, tingenonee, and 20-alpha-hydroxytingenone) are reported for the first time. The natural products were isolated from Maytenus sp. (Celastraceae) and their effects tested on larvae of codling moth (Cydia pomonella, Lepidoptera: Tortricidae). The three metabolites produce the same effects on codling moth larvae that azadirachtin does, although at higher concentrations. 20-alpha-Hydroxytingenone was the most active compound, showing lethal, antifeedant, and insect growth regulation activities. Pristimerin showed also a high antifeedant activity together with its molt effect suppression. Tingenone showed the lowest activity. The differences in the activity of the three products are related to the structure of the E ring. 相似文献
7.
Diabetes and hypertension increases in a society with abdominal obesity: results of the Mexican National Health Survey 2000 总被引:5,自引:0,他引:5
Sánchez-Castillo CP Velásquez-Monroy O Lara-Esqueda A Berber A Sepulveda J Tapia-Conyer R James WP 《Public health nutrition》2005,8(1):53-60
OBJECTIVES: To determine the prevalences of overweight, obesity, type 2 diabetes mellitus (DM) and hypertension (HT) in the Mexican population and compare them with those of a previous Mexican urban survey and an American survey. DESIGN: A structured, randomised, nationally representative Mexican sample was compared with a 1993 Mexican urban survey and the US Third National Health and Nutrition Examination Survey (NHANES III) of non-Hispanic Whites. SETTING: The Mexican National Health Survey 2000.Subjects: Subjects were 12,856 men and 28,332 women, aged 20-69 years, who had their body weight, height, waist circumference (WC), blood pressure and fasting capillary blood glucose measured. RESULTS: Mexican adult men and women had a high prevalence of overweight (41.3 and 36.3%, respectively) and obesity (19.4 and 29.0%, respectively), similar to those in the USA in 1988-1992 and exceeding those of the 1993 Mexican survey. The prevalence of HT was 33.3% in men and 25.6% in women, with inferred DM rates of 5.6 and 9.7%, respectively. Abdominal obesity affected 46.3% of men (WC>or=94 cm) and 81.4% of women (WC>or=80 cm). There was a high prevalence of abdominal obesity in normal-weight women, with co-morbidities relating better to WC than to body mass index (BMI) in both sexes. Rates of DM and HT exceeded US rates on a comparable BMI or WC basis in adults aged <50 years. CONCLUSION: The high prevalence of obesity and abdominal obesity in Mexicans is associated with markedly increased prevalences of DM and HT to levels comparable with, or even higher than, those in NHANES III of non-Hispanic Whites. 相似文献
8.
The content of S-alk(en)ylcysteine sulfoxides, important nonvolatile flavor precursors, was determined in 15 different Allium species by means of gas chromatography. The method employed is based on derivatization of S-alk(en)ylcysteine sulfoxides with ethyl chloroformate followed by their reduction with sodium iodide. The total content of S-alk(en)ylcysteine sulfoxides varied considerably in the wide range between 0.02 and 1.3% fresh weight. Not only the total content but also relative proportions of individual derivatives varied to a great extent. A novel S-alkylcysteine derivative, S-ethylcysteine sulfoxide (ethiin), not previously reported to occur in Allium species, was found in most of the samples examined in trace amounts. None of the other S-alk(en)ylcysteine sulfoxides, for example, isopropyl, (Z)-1-propenyl, butyl, or pentyl, were detected in any of the samples analyzed, limiting possible levels of each of these components to =1 ppm in fresh weight. 相似文献
9.
Colunga GB Arriaga-Jordán CM Veláquez Beltran L González-Ronquillo M Smith DG Estrada-Flores J Rayas-Amor A Castelán-Ortega OA 《Tropical animal health and production》2005,37(Z1):143-157
The aim of this work was to describe the feeding strategies for donkeys used by peasant farmers in central Mexico. Feeding strategies for the dry and wet seasons are described, as well as the nutritional characteristics of the main forages and supplements used by the farmers. The extent to which the feeding practices used by farmers matched the digestible energy and crude protein requirements of donkeys for maintenance and work was determined. It was concluded that grazing on native grassland could provide enough energy and protein for donkeys at maintenance level and for those performing only a moderate amount of work. More research in required in order to have better estimates of intake and plant species preferred by donkeys under prevailing grazing conditions. 相似文献
10.
Ortiz GG Feria-Velasco A Tarpley RL Bitzer-Quintero OK Rosales-Corral SA Velázquez-Brizuela IE López-Navarro OG Reiter RJ 《Anatomia, histologia, embryologia》2007,36(3):209-214
The ultrastructure of the Atlantic Bottlenose dolphin Harderian gland (HG) has been described but some questions remain unanswered. The purpose of this work was to define the gland's structure, ultrastructure and the differences between cells (types I and II) of the male dolphin using optic, fluorescence and electron transmission microscopy. Three different cells were observed under optic and fluorescence microscopic examination, while only two cell types (types I and II) were distinguished by electron transmission microscopy. Type I (oval nuclear envelope) exhibited three different cell populations and type II (indented nuclear envelope) exhibited two different cell populations. Although, we observed both types of vesicles in both types of cells they differed, principally, in quantity. The glands also possessed prominent duct systems, with three orders of complexity. The dolphin orbital HG appears to function as a mixed heterologous gland with two types of cells that exhibit both types of vesicles and other distinguishable differences. 相似文献