首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   76篇
  免费   1篇
林业   2篇
农学   3篇
  19篇
综合类   9篇
农作物   7篇
水产渔业   1篇
畜牧兽医   31篇
植物保护   5篇
  2022年   2篇
  2021年   6篇
  2020年   3篇
  2019年   1篇
  2018年   1篇
  2015年   1篇
  2013年   4篇
  2012年   3篇
  2011年   4篇
  2010年   2篇
  2009年   1篇
  2008年   5篇
  2007年   1篇
  2006年   3篇
  2005年   3篇
  2004年   3篇
  2003年   7篇
  2002年   6篇
  2001年   3篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1996年   3篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1985年   2篇
  1982年   1篇
  1970年   1篇
  1969年   1篇
  1958年   1篇
  1953年   1篇
  1950年   1篇
排序方式: 共有77条查询结果,搜索用时 218 毫秒
11.
Lipase-catalyzed synthesis of lipophilic phenolic antioxidants was carried out with a concentrate of n-3 polyunsaturated fatty acids (PUFAs), recovered from oil extracted from salmon ( Salmon salar ) byproduct. Vanillyl alcohol and rutin were selected for the esterification reaction, and obtained esters yields were 60 and 30%, respectively. The antioxidant activities of the esters were compared with those of commercial butylated hydroxytoluene (BHT) and α-tocopherol using DPPH radical scavenging and thiobarbituric acid assays. In the DPPH assay, rutin esters showed better activity than vanillyl esters, and on the contrary in lipophilic medium, vanillyl esters were found to be superior to rutin esters. In bulk oil system, the antioxidant activities of rutin and vanillyl derivatives were lower than that of BHT and α-tocopherol, but in emulsion, they showed better activity than α-tocopherol. By attaching to natural phenolics, the PUFAs are protected against oxidation, and PUFA improves the hydrophobicity of the phenolic, which could enhance its function in lipid systems.  相似文献   
12.
Cottonseed protein has the potential to increase the world's food supply while decreasing the incidence of malnutrition among the world's hungry. Nutritionally, cottonseed flour compares favorably to other animal and vegetable protein sources, as it is low in fat and contains a substantial amount of high biological value protein. Animal studies, as well as human research, using gossypol-free glandless cottonseed flour have shown that cottonseed protein promotes growth, increased weight gain, and a positive nitrogen balance. Cottonseed protein food products have been shown to be a healthy addition to the diets of children, college-age women, and the elderly. With its light color and bland flavor, cottonseed has many uses in the food processing arena. Baked goods, snack foods and candy, as well as pet and livestock feed are just a few successful products developed utilizing cottonseed protein.  相似文献   
13.
The beet armyworm (Spodoptera exigua Hübner)is the most important pest in tropical Alliumcultivations. All shallot (Allium cepa L. group Aggregatum) cultivars are susceptible to this pest. Therefore accessions from three wild Alliumspecies, namely A. galanthum Kar. et Kir., A. fistulosum L. and A. royleiStearn, next to A. cepa L. were used to screen for resistance. First of all, a reliable bio-assay had to be developed. To this end transparent plastic cages with in total 5 plants of one accession per cage were placed on per lite in a heated greenhouse. Five 3-day old larvae were inoculated on each plant. Eight days after inoculation the number of surviving larvae per cage and the mean fresh weightper larva was determined. The lowest larval survival (36%) was found on A. roylei. This was not, however, significantly different from other Allium accessions. Significant differences were found in the fresh weight per larva fed on different Allium accessions. The larvae survived on A. roylei had a very low fresh weight (10.3 mg per larva), while those on an accession of A. fistulosum had the highest fresh weight (45.1 mg per larva). The larval fresh weight on A. roylei was lower than all the other accessions except from the tropical shallot cultivar Bawang Bali. To check whether or not a toxic compound was involved in the resistance present in A. roylei, tenaccessions from four Allium species were screened. Five 3-day old larvae were inoculated on regularly replaced leaf material of each accession ofAllium species. No significant differences were found in mean fresh weight per larva and mean survival of larvae among different accessions. There were also no significant differences in pupal weight and developmental time. All larvae became pupae 10 days after inoculation. The data indicate that there is no toxic compound present in A. roylei. These results are underlined by the observation in the greenhouse bio-assay that A. roylei plants were equally damaged by the beet armyworm compared to otherAllium species. The results obtained so far therefore suggest that introduction of resistance to S. exigua via the exploitation of variation for resistance to the beet armyworm in A. roylei is unclear and that genetic engineering using Cry sequences could provide a way forward. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
14.
Two distinct races ofDitylenchus dipsaci in Israel were identified: one, which infects and damages onion and garlic, reproduces on pea, but does not infect phalaris grass; and a second, which infects and damages phalaris—and, probably, also ‘Saia’ oats—but fails to infect onion and garlic. A new ‘garlic’ race of the nematode does not appear to have been introduced into Israel together with the ‘Lavinia’ garlic cultivar, as previously speculated, but rather the introduced Lavinia clone is highly susceptible to the existing ‘onion and garlic’ race ofD. dipsaci.  相似文献   
15.
Previous research demonstrates that supplementing 0.20% l-glutamine (GLN) in the diets of newly weaned and transported pigs improves growth rate to a similar extent as providing dietary antibiotics (AB). However, research comparing the effects of GLN vs. AB on intestinal physiology and the microbiome is limited. Therefore, the study objective was to compare the effects of supplementing nursery diets with GLN, AB, or no dietary antibiotics (NA) on intestinal physiology and the microbiome of pigs in a production environment following weaning and transport. Mixed-sex piglets (N = 480; 5.62 ± 0.06 kg body weight [BW]) were weaned (18.4 ± 0.2 d of age) and transported for 12 h in central Indiana, for two replicates, during the summer of 2016 and the spring of 2017. Pens were blocked by BW and allotted to one of the three dietary treatments (n = 10 pens/dietary treatment/replicate [8 pigs/pen]): AB (chlortetracycline [441 ppm] + tiamulin [38.6 ppm]), GLN (0.20% as-fed), or NA fed for 14 d. From day 14 to 34, pigs were fed common AB-free diets in two phases. On day 33, villus height:crypt depth tended to be increased (P = 0.07; 7.0%) in GLN and AB pigs vs. NA pigs. On day 33, glucagon-like peptide 2 (GLP-2) mRNA abundance was decreased (P = 0.01; 50.3%) in GLN and NA pigs vs. AB pigs. Crypt depth was increased overall on day 33 (P = 0.01; 16.2%) during the spring replicate compared with the summer replicate. Villus height:crypt depth was reduced (P = 0.01; 9.6%) during the spring replicate compared with the summer replicate on day 33. On day 13, tumor necrosis factor-alpha and occludin mRNA abundance was increased (P ≤ 0.04; 45.9% and 106.5%, respectively) and zonula occludens-1 mRNA abundance tended to be greater (P = 0.10; 19.2%) in the spring replicate compared with the summer replicate. In addition, AB pigs had increased (P = 0.01; 101.3%) GLP-2 mRNA abundance compared with GLN and NA pigs. Microbiome analysis indicated that on day 13, dietary treatment altered the microbiota community structure (P = 0.03). Specifically, the AB pigs tended to be distinct from both the NA and GLN pigs (P = 0.08), and Lactobacillus was increased nearly 2-fold in AB compared with NA pigs (q = 0.04) and GLN pigs (q = 0.22). In conclusion, GLN supplementation tended to improve some morphological markers of intestinal health similarly to AB pigs, while the microbiome composition in GLN pigs was more similar to NA pigs than AB pigs.  相似文献   
16.
The seedling growth trait, cyclic growth, is well-correlated with older-tree heights measured in Pinus taeda L. field trials. These results have been repeatable across locations and seed sources if a standard greenhouse procedure is followed. This work is been limited to cyclic growth measured on P. taeda families and seed sources. The use of a standard greenhouse procedure will facilitate comparison with other early genetic evaulation methods for P. taeda and with similar studies on other Pinus species.  相似文献   
17.
The prevalence of blowfly strike in rabbits in southwest England and Wales was investigated using a retrospective postal survey of small animal and mixed veterinary practices. Questionnaires were sent to 474 practices; 219 were returned completed, giving a response rate of 46.2%. The prevalence of blowfly strike was estimated as the percentage of veterinary practices that reporting having treated at least one rabbit for strike between May and September 2005. Overall, 94.5% (+/-2.21) of practices treated at least one case of rabbit strike. Almost half, 49.3% (+/-11.3) of practices reported treating only 1-5 rabbits for blowfly strike in the study period; 32.8% (+/-4.56), 13% (+/-3.27) and 4.8% (+/-2.08) treated 6-10, 11-15 and more than 15 struck rabbits, respectively. In 46.3% (+/-4.84) of the practices most infested rabbits survived. For 40.4% (+/-4.77) of practices, about half the struck rabbits survived. However, for 13.3% (+/-3.30) of practices most struck rabbits were reported to have died. The practices reporting that most animals died were those that saw significantly fewer rabbits and fewer struck rabbits than practices where more animals survived. This suggests that training and experience in the appropriate care of infested rabbits may be critical in ensuring a favorable outcome.  相似文献   
18.
A 7-month-old female spayed domestic shorthair cat was presented for investigation of stertor, open mouth breathing without apparent distress, and chronic bilateral nasal discharge that was unresponsive to antibiotics. Complete bilateral bony choanal atresia was diagnosed with computed tomography and nasopharyngoscopy. Choanal atresia is an uncommon congenital condition where the choana (nasal passage into the nasopharynx) is blocked by abnormal bone or soft tissue uni- or bilaterally. The cat's clinical signs improved dramatically immediately after trans-palatal surgical correction. Post-surgical complications included the development of nasopharyngeal scar tissue and subsequent stenosis, persistent right-sided nasal discharge, and permanent damage to the right eye (blindness and cataract formation). Nasopharyngeal stenosis was managed with repeated balloon dilatations and temporary stenting, and the owner reported an excellent quality of life at 8-month follow-up. Bilateral bony choanal atresia has not been previously reported in cats. Uni- or bilateral choanal atresia should be considered in young cats presenting with refractory stertor, chronic nasal discharge, and/or open mouth breathing.  相似文献   
19.
An increase of 11–31% of dry mycelial mass was observed along with a slight decrease (5–10%) in aflatoxin Bi production in 5-day-old aflatoxigenicAspergillus spp. submerged cultures containing either 0.5 ml or 1.0 ml clarified neem oil (CNO) in 0.1 % Triton solution. Fungal growth and aflatoxin B1 production were also determined in potato-dextrose-agar petri plate cultures inoculated with aflatoxigenicAspergillus spp. containing an atmosphere of volatiles emitted from 0.25 ml, 0.5 ml, and 1.0 ml CNO added to the plates. After 5 days’ incubation, fungal radial growth was reduced by 7–29% and aflatoxin B1 production by 0–67%. GC/MS analysis of the head space volatiles of the CNO indicated that the reduction of fungal growth and aflatoxin B1 was probably due to low molecular weight hydrocarbons, aldehydes, alcohols, and sulfur compounds emitted at 30°C in the dry culture. These results suggest that volatiles emitted from CNO at 30° C in plate cultures were more fungistatic and consequently inhibited aflatoxin production more than neem oil added in liquid cultures.  相似文献   
20.
A urethrorectal fistula was diagnosed in a 10-week-old, intact male bulldog, presented with a history of urine dribbling from his anus. The fistula was ligated using a novel perineal approach, resulting in resolution of clinical signs. The described procedure is simpler and less invasive than previously described repairs.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号