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   102篇
  免费   8篇
林业   9篇
农学   5篇
  30篇
综合类   9篇
农作物   7篇
水产渔业   8篇
畜牧兽医   34篇
植物保护   8篇
  2023年   1篇
  2022年   4篇
  2021年   4篇
  2020年   6篇
  2019年   6篇
  2018年   2篇
  2017年   5篇
  2016年   8篇
  2015年   5篇
  2014年   4篇
  2013年   7篇
  2012年   8篇
  2011年   11篇
  2010年   1篇
  2009年   2篇
  2008年   1篇
  2007年   5篇
  2006年   4篇
  2005年   6篇
  2004年   8篇
  2003年   4篇
  2002年   2篇
  2001年   2篇
  1999年   1篇
  1997年   2篇
  1986年   1篇
排序方式: 共有110条查询结果,搜索用时 15 毫秒
81.
This review presents the clinical, dermato-histopathological and genetic features of canine X-linked ectodermal dysplasia in previously reported cases and in three new spontaneous cases. The condition is compared with anhidrotic ectodermal dysplasia in humans and, based on current genetic concepts, we suggest that the two conditions are caused by the same gene and, consequently, represent a single pathological entity that affects both humans and dogs.  相似文献   
82.
83.
An experiment was conducted to evaluate the effects of phytase (PHY), alone or in combination with citric acid (CA), on growing Japanese quails under moderate and severe phosphorus (P) restriction. For this, 504 one‐day‐old female quails were distributed in a completely randomised design with seven treatments and six replications. Treatments consisted of the following diets: (a) positive control (PC): formulated according to quails nutritional requirements; (b) negative control 40% (NC40): PC with 40% less aP; (c) NC40+PHY; (d) NC40+PHY+CA; (e) negative control 65% (NC65): PC with 65% less aP; (f) NC65+PHY; (g) NC65+PHY+CA. Phytase and CA were included at 300 FTU/kg and 40 g/kg, respectively. Performance, bone mineralization and plasma mineral concentration were evaluated at day 35; calcium (Ca) and P metabolism, between days 36 and 39. No significant differences in performance, plasma Ca and P were detected between quails fed PC or NC40; however, NC40 decreased tibia ash (p < 0.01). Treatment NC65 impaired daily weight gain (p = 0.01), tibia ash (p < 0.01), and tibia optical densitometry (p = 0.03), as well as modified plasma Ca (p < 0.01) and P (p = 0.03) concentrations when compared to PC. Both NC40 and NC65 reduced P excretion (p < 0.01). Phytase alone restored tibia ash of NC40 quails to regular rates. Nevertheless, only PHY and CA combined returned plasma P, tibia ash, tibia optical densitometry, and daily weight gain of quails fed NC65 to similar values as those observed in PC. In conclusion, PHY alone suppresses the negative effects of moderate P restriction in growing Japanese quails, but fails in this task under severe P restriction. In such a situation, only the combination of PHY and CA ensures regular rates of growth and bone mineralization. This concept should be better explored by producers in order to take full advantage of the reduction in P excretion achieved by lowering dietary P concentrations.  相似文献   
84.
This study aims to investigate the effect of different cooling rates on the semen cryopreservation of curimba (Prochilodus lineatus). Nineteen ejaculates were obtained from adults males and cryopreserved at 15°C/min (CR15), 30°C/min (CR30) (controlled temperature inside and outside straw, speed was stable during freezing) and direct freezing in liquid nitrogen vapour (~35.6°C/min) (CRNV). The straws were thawed and seminal parameters evaluated. DNA fragmentation through the comet assay was assessed. A fresh sperm sample was not frozen and used for analyses. Data were submitted to an analysis of variance (ANOVA), and means were compared by Scott–Knott test (p < 0.05) using the R Software. Mean motility percentage was 100%, and motility duration was 39.5 ± 5.7 s for the fresh sperm (subjective analysis); 58.9 ± 8.0% and 24.5 ± 5.7 s for CR15; 64.8 ± 4.8% and 26.5 ± 7.1 s for CR30; and 50.1 ± 16% and 25.7 ± 4.7 s for CRNV, respectively. Motility percentages were higher and equal between CR15 and CR30 compared to CRNV (p < 0.05). Some sperm motion kinetics, namely average path velocity (VAP) and straight line velocity (VAS), were higher for CR30 (p < 0.05), while curvilinear velocity (VCL) and velocity progression (PRO) were lower for CRNV (p < 0.05). Straightness (STR) and wobble (WOB) were the same among treatments (p > 0.05). Sperm morphology results indicated higher means for total morphological sperm alterations in CRNV. All cooling rates caused sperm DNA fragmentation, although CR30 provided a less harmful effect. This is the first report for cryopreserved P. lineatus sperm preserved under different controlled cooling rates. The cooling rate of 30°C/min is indicated for the cryopreservation of this fish sperm as it led to the lowest detrimental spermatozoa effects.  相似文献   
85.
86.
The partial replacement of a commercial concentrate at 10‐20% and 15‐30% (the first percentage of each dietary treatment corresponded to weeks 1–3 and the second to weeks 4–7 of the experiment, respectively) by sweet potato meal (SPM; 70% foliage: 30% roots) was evaluated for growth performance, carcass yield, instrumental and sensory pork quality using 36 commercial crossbred pigs (56.8 ± 1.3 kg initial body weight). Three dietary treatments were compared in a randomized complete block design. Most growth, carcass traits and pork quality variables were not affected by the SPM inclusion. Growth performance averaged 868 g/day and feed efficiency 0.24 kg/kg. However, feed intake increased 2.2% (P = 0.04) in pigs fed the 10‐20% SPM diets, in a similar order of magnitude as the decrease in dietary energy. Despite an increase in gastrointestinal tract as a percent of hot carcass weight (+14.7%) (P = 0.03) with SPM inclusion, carcass yield averaged 69.4%. Conversely, decreases in loin yield (?4.2%) (P = 0.05), backfat thickness (?6.0%) (P < 0.01) and pork tenderness (?13%) (P = 0.02) were observed with 15‐30% SPM inclusion. Results suggest that up to 20% SPM inclusion is a viable feed strategy for finishing pigs, easily replicable in small farm settings. © 2016 Japanese Society of Animal Science  相似文献   
87.
88.
89.
Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.  相似文献   
90.
Target region amplification polymorphism (TRAP) markers were used to estimate the genetic similarity (GS) among 53 sugarcane varieties and five species of the Saccharum complex. Seven fixed primers designed from candidate genes involved in sucrose metabolism and three from those involved in drought response metabolism were used in combination with three arbitrary primers. The clustering of the genotypes for sucrose metabolism and drought response were similar, but the GS based on Jaccard’s coefficient changed. The GS based on polymorphism in sucrose genes estimated in a set of 46 Brazilian varieties, all of which belong to the three Brazilian breeding programs, ranged from 0.52 to 0.9, and that based on drought data ranged from 0.44 to 0.95. The results suggest that genetic variability in the evaluated genes was lower in the sucrose metabolism genes than in the drought response metabolism ones.  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