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   86篇
  免费   0篇
林业   1篇
  11篇
农作物   3篇
水产渔业   5篇
畜牧兽医   45篇
植物保护   21篇
  2022年   2篇
  2021年   11篇
  2020年   3篇
  2019年   2篇
  2018年   1篇
  2017年   2篇
  2016年   3篇
  2015年   5篇
  2014年   5篇
  2013年   7篇
  2012年   1篇
  2009年   2篇
  2008年   5篇
  2007年   6篇
  2006年   5篇
  2005年   3篇
  2004年   5篇
  2003年   3篇
  2002年   9篇
  2001年   4篇
  2000年   2篇
排序方式: 共有86条查询结果,搜索用时 15 毫秒
51.
Sesbania rostrata Brem. & Oberm. has been used as a promising halophytic plant to improve saline soil in north-east Thailand. Our previous study suggested that the salt tolerance of this plant was associated with its ability to translocate Na+ and Cl ions from roots to shoots and trap them in the shoot cells. The present study further investigated the effect of NaCl on the activity of antioxidative enzymes and the tolerance to an active oxygen species generator, paraquat in S. rostrata leaves. Higher constitutive levels of antioxidative enzyme activities, such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR), as well as higher levels of induced CAT and SOD activities with salinity stress were found in salt-tolerant S. rostrata than salt-sensitive Phaseolus vulgaris L. cv. Meal. Tolerance of S. rostrata to paraquat determined by the chlorophyll content in leaf disks increased with NaCl treatment. These findings indicate that S. rostrata exhibits better protection against the oxidative damage caused by NaCl, at least partly due to a higher constitutive and induced activities of antioxidative enzymes.  相似文献   
52.
The present study was conducted to elucidate the effect of dietary lysine levels on the intramuscular fat (IMF) content in the Longissimus dorsi (L. dorsi) muscles of finishing gilts. Eleven gilts in total from two litters of pigs aged 110 days were used. The average initial bodyweight of the pigs was 61.7 kg. Six pigs were assigned to the low lysine (LL) diet group (lysine content: 0.43 or 0.40%) and five pigs were assigned to the control group (lysine content: 0.65 or 0.68%). The diets were iso‐energetic and iso‐protein, and contained all essential amino acids (apart from lysine) in the recommended amounts. The pigs were fed these diets until their live weights reached 110 kg. Live weight gain and feed efficiency tended to be lower in the LL group (P = 0.118 and P = 0.052, respectively). Pigs from the LL group took 5 days longer to reach 110 kg (P < 0.01). The IMF content in the L. dorsi of the LL group was twice as high as that of the control group (6.7 vs 3.5%; P < 0.01). The percentage of oleic acid in the L. dorsi of the LL group tended to be higher than that of the control group (P = 0.052), whereas the percentage of linoleic acid and the total percentage of polyunsaturated fatty acids in the L. dorsi were lower (P < 0.05) in the LL group. Free L‐carnitine content in the L. dorsi was lower (P < 0.05) in the LL group. The average abundance of peroxisome proliferator‐activated receptor gamma mRNA in the L. dorsi of the LL group was threefold higher than that of the control group. The leptin mRNA abundance in the L. dorsi of the LL group was 3.3‐fold higher than that of the control group (P < 0.01). These results suggest that a higher activity of adipogenesis may have been involved in the promoted accumulation of IMF in the L. dorsi muscles of pigs, induced by a dietary LL level.  相似文献   
53.
The phytotoxic activities of the crude extract from the cyanobacterium, Hapalosiphon sp., on the initial growth and root cell division of several plant species were investigated. Although the germination percentages of the plants were not affected by the extract, their root and shoot growth were remarkably suppressed, depending on the extract concentrations. Roots were more sensitive to the extract than shoots and the sensitivity, determined by the I50 concentrations between the susceptible and tolerant species, differed by 5 and 11 times in dicotyledonous and monocotyledonous plants, respectively. The mitotic index for wheat ( Triticum aestivum L. cv. Norin 61) root cells was not affected, but the mitotic index for onion ( Allium cepa L. cv. Raputa II) was reduced with the increasing concentration of the extract. In the onion root meristem, the number of cells in prophase, metaphase, anaphase, and telophase were decreased significantly with 6 g DW L−1 (g dry weight of algae L−1). This suggests that the extract might inhibit the processes regulating the entry of cells into mitosis.  相似文献   
54.
To study the group‐dependent ecology of Fibrobacter succinogenes in the rumen, real‐time polymerase chain reaction assays for two phylogenetic groups (groups 2 and 3) of F. succinogenes were newly established and applied to rumen samples. Both the assays targeting the bacterial 16S rDNA were sensitive and accurate, showing wide quantifiable ranges (104?109 and 102?109 copies of 16S rDNA) and high recoveries of known amounts of added DNA (96.9 and 98.0%). The quantity of group 1 was confirmed to be numerable by subtracting assay values of groups 2 and 3 from that of F. succinogenes species (groups 1–3). By using the developed assays and the above subtractive calculation, the quantities of all three groups were evaluated in solid and liquid fractions of the rumen content and also on hay stems. In the solid fraction, groups 1 and 2 were abundantly present, compared with group 3 (P < 0.05). On untreated hay stems, group 1 was dominant throughout 48 h. In addition, group 1 showed growth even on the cellulase‐treated hay stems, unlike the other two groups. These results suggest that F. succinogenes group 1 greatly contributes to rumen fiber digestion, even for less degradable materials.  相似文献   
55.
In July 2020, a sow in a breeding herd in the Chiba Prefecture, Japan, suffered abortion. A necropsy revealed pale pulmonary foci scattered in the two fetuses. Histologically, multifocal pulmonary necrosis was detected with numerous yeasts. The yeast was positively stained using the periodic acid-Schiff reaction and Grocott’s silver stain. Molecular identification indicated that the yeast was Candida parapsilosis. In conclusion, our results suggested that C. parapsilosis caused multifocal necrotizing pneumonia in the two fetuses. This study is the first report of a swine abortion with C. parapsilosis infection.  相似文献   
56.
Pulmonary hypertension (PH) is a common comorbidity in dogs with myxomatous mitral valve disease (MMVD), and can induce various changes in the right heart, such as right ventricular (RV) hypertrophy, dilatation, and dysfunction. We hypothesized that RV function, not only systolic function but also diastolic function, could be worsened with PH progression. We aimed to compare RV systolic and diastolic function in dogs with MMVD. Twenty healthy dogs and sixty-eight dogs with MMVD were enrolled. Dogs with MMVD were classified into the probability of PH. Two-dimensional and Doppler echocardiographic indices for right heart and two-dimensional speckle tracking echocardiography indices were measured. The morphological indicators of the right heart were significantly higher only in the high probability of PH group. The RV strain, early-diastolic and systolic strain rates were significantly lower in the high probability of PH group than those in the low and intermediate probability of PH groups. Multivariate analysis showed that increased RV internal dimension normalized by body weight and RV myocardial performance index were significantly associated with the presence of right-sided congestive heart failure. Speckle tracking echocardiography-derived RV systolic and diastolic function were activated in the low and intermediate probability of PH groups. However, dogs with high probability of PH showed RV myocardial dysfunction and dilatation. Increased RV myocardial performance index and end-diastolic RV internal dimension normalized by body weight were significantly associated with the presence of right-sided congestive heart failure in dogs with MMVD.  相似文献   
57.
58.
对氧碱漂白过程中木质素氧化进行定量分析,分析方法是基于氧化前后高锰酸钾消耗量的变化。该方法对溶出残余木质素的氧化结果分析发现其呈明显3个阶段:第一段木质素氧化的当量电荷数约4~5/木质素单元;木质素总氧化电荷数大约为9/木质素单元。这些数据以及甲氧基的脱除(75%)均表明:木质素的氧化不仅发生在酚型木质素单元,同时也发生在非酚型结构单元上。只有第一阶段氧化反应是木质素与氧气直接反应,而在第二、三阶段主要是协同氧化作用,氧化反应过程中产生的活性氧基团扮演了一定角色。通过对低浓度针叶材硫酸盐浆的氧漂研究发现:当卡伯值下降一半(25.4至13.4)时平均每个木质素单元氧化3当量电子,氧漂后的纸浆中仍然有大量未被氧化的残余木质素。定量地证明了在氧漂过程中木质素氧化是脱木质素反应的实质。  相似文献   
59.
Difficulty in airway management during anesthesia was noted in a 10-year-old, castrated, male Pekingese dog and a 13-year-old male French Bulldog. They showed strong resistance during tracheal tube insertion through the subglottic lumen. Therefore, the airway was secured by using a small endotracheal tube or supraglottic airway device. Computed tomography scan revealed a markedly narrower vertical dimension of the cricoid cartilage compared to that seen in common brachycephalic breeds. Posterior glottis was relatively more accessible for translaryngeal intubation in the present cases. Our findings showed that brachycephalic airway syndrome may be associated with narrow cricoid cartilage. To the best of our knowledge, this is the first clinical case report of airway management during anesthesia in dogs with narrow cricoid cartilage.  相似文献   
60.
The prevalence of Toxoplasma gondii infection in free-ranging cats on Tokunoshima Island was assessed by testing 125 serum samples using anti-T. gondii IgG indirect enzyme-linked immunosorbent assay. The overall seropositivity rate was 47.2% (59/125). Seropositivity rates in cats with body weight >2.0 kg (57.4%) were significantly higher than in those with body weight ≤2.0 kg (12.5%, P<0.01). Analysis of the number of seropositive cats by settlement revealed the presence of possibly-infected cats in 17 of 23 settlements, indicating the widespread prevalence of T. gondii on the island. This is the first study to show the seroprevalence of T. gondii in free-ranging cats on Tokunoshima Island. The information revealed in this paper will help to prevent the transmission of T. gondii among cats and also in both wild and domestic animals and humans on the island.  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