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   14篇
  免费   1篇
农学   6篇
  2篇
综合类   1篇
水产渔业   2篇
畜牧兽医   4篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2016年   1篇
  2014年   1篇
  2012年   1篇
  2011年   2篇
  2004年   1篇
  2003年   1篇
  1994年   1篇
  1989年   2篇
  1988年   1篇
排序方式: 共有15条查询结果,搜索用时 390 毫秒
1.
Fatty acids are the largest component of lipids and have become a useful tool in the determination of live feeds to a variety of cultured species. Bioencapsulation is a technique which allows high-level incorporation of desired components (i.e., fatty acids, vitamins, antibiotics, etc.) in live feeds, which in turn can be supplemented to the consumer organisms. The procedure described in the present study serves as a platform of technology for enriching the Streptocephalus dichotomus. Uptake of two enrichment diets (ALGAMAC2000 and DHA-SELCO) by adult S. dichotomus was investigated. The fatty acid profile supports the hypothesis that the enrichment diet increases the level of essential fatty acids, such as linolic, linolenic, eicosapentenoic, and docosahexaenoic acids. The average content (percent of total fatty acids detected) of the enriched organism by different highly unsaturated fatty acid (HUFA) products were as follows: ALGAMAC2000 showed 14-22% saturated fatty acid (SFA), 17-18% monounsaturated fatty acid (MUFA), 28-41% polyunsaturated fatty acid (PUFA), 23-34% n-3, and 4.9-7.5% n-6, whereas DHA-SELCO showed about 20-23% SFA, 20-26% MUFA, 38% PUFA, 28-31% n-3, and 7.5-10% n-6. Our present investigation proves that both HUFA-rich diets appear to be an appropriate enrichment diet, and further provides an additional rationale for using fairy shrimp as a maturation diet for any cultivable freshwater organism.  相似文献   
2.
Two field experiments were carried out one after the other to study the effect of date of sowing and soil temperature on the soil nitrogen availability and yield of sorghum (Co. 25). Crops sown at weekly intervals were the treatments. Mean soil temperature at different depths, available soil N at different stages, leaf area index were assessed and correlation among different parameters established. The results indicated that time of sowing sorghum crop influenced the soil available N due to variations in soil temperature and the eanopv development at different levels as measured by leaf area indices.
Mean soil temperature increased with depths upto 30 cm. Also available N varied at different stages of crop growth but invariably higher in early sown crops Qanuary sown). Soil temperature at 15 cm depth influenced the available soil N most and consequently the leaf area index. This was reflected in the yield also.  相似文献   
3.
Two field trials with paddy crop were raised to study the root distribution characteristics under mechanical impedance. Plots varying in bulk density were created by passing 400 kg stone roller (1 meter width) 8 times and 16 times. After harvest of the first crop 32P was injected to the paddy stubbles and the percentage of total radioactivity at different layers upto 30 cm was calculated to study the root distribution characteristics. The results revealed that 47.2 per cent of the roots are distributed in the first 10 cm of the soil, 29.5 and 23.3. per cent were found in the second and third 10 cm layers, respectively. As the mechanical resistance increased 62.9 to 67.0 per cent of the roots were found in the top 10 cm layer. The root distribution pattern in the second crop was studied by the procedure of N ewman (1966). The trend of results were as for the first crop.  相似文献   
4.
Nipah (Nee-pa) viral disease is a zoonotic infection caused by Nipah virus (NiV), a paramyxovirus belonging to the genus Henipavirus of the family Paramyxoviridae. It is a biosafety level-4 pathogen, which is transmitted by specific types of fruit bats, mainly Pteropus spp. which are natural reservoir host. The disease was reported for the first time from the Kampung Sungai Nipah village of Malaysia in 1998. Human-to-human transmission also occurs. Outbreaks have been reported also from other countries in South and Southeast Asia. Phylogenetic analysis affirmed the circulation of two major clades of NiV as based on currently available complete N and G gene sequences. NiV isolates from Malaysia and Cambodia clustered together in NiV-MY clade, whereas isolates from Bangladesh and India clusterered within NiV-BD clade. NiV isolates from Thailand harboured mixed population of sequences. In humans, the virus is responsible for causing rapidly progressing severe illness which might be characterized by severe respiratory illness and/or deadly encephalitis. In pigs below six months of age, respiratory illness along with nervous symptoms may develop. Different types of enzyme-linked immunosorbent assays along with molecular methods based on polymerase chain reaction have been developed for diagnostic purposes. Due to the expensive nature of the antibody drugs, identification of broad-spectrum antivirals is essential along with focusing on small interfering RNAs (siRNAs). High pathogenicity of NiV in humans, and lack of vaccines or therapeutics to counter this disease have attracted attention of researchers worldwide for developing effective NiV vaccine and treatment regimens.  相似文献   
5.
In swine, even though the pregnant sows were with iron abundance, the inborn iron reserve of piglets was compromised. This indicates the insufficiency of molecular machinery involved in local placental iron flux. Here, we investigated the expression of iron regulatory proteins like hepcidin and ferroportin and also their association with iron reserve, inflammation and oxidative stress in placenta of full-term pregnant sows (n = 6). Amplification and sequencing of placental DNA confirmed the presence of hepcidin (MN579557) and ferroportin (MN565887) sequences and their 100% identity with existing GenBank data. Real-time amplification of placental mRNA revealed significant higher expression of hepcidin (p < .05) than ferroportin. Western blot analysis of placental tissues revealed specific bands for both hepcidin (~8 kDa) and ferroportin (~62 kDa) molecules. Immunohistochemistry revealed the immunoreactivity for both proteins in the cytoplasm and membrane of trophoblastic cells of the placenta. Hepcidin and ferroportin expressions were positively associated with placental non-haem iron reserve (p < .0001; p = .033), lipid peroxidation (p = .0060; p < .0001) and reactive oxygen species level (p = .0092; p = .0292). Hepcidin expression was positively associated with interleukin – 6 (p = .0002) and interferon gamma (p < .0001) expressions but ferroportin expression was negatively associated with interleukin-6 (p = .0005), interleukin-1β (p = .0226) and interferon gamma (p = .0059) expressions. This indicates hepcidin and ferroportin may have a role in controlling the local placental iron flux by acting as a molecular bridge between iron trafficking and inflammation.  相似文献   
6.
The measured dispersion of a low-loss, hollow-core photonic band-gap fiber is anomalous throughout most of the transmission band, and its variation with wavelength is large compared with that of a conventional step-index fiber. For an air-filled fiber, femtosecond self-frequency--shifted fundamental solitons with peak powers greater than 2megawatts can be supported. For Xe-filled fibers, nonfrequency-shifted temporal solitons with peak powers greater than 5.5 megawatts can be generated, representing an increase in the power that can be propagated in an optical fiber of two orders of magnitude. The results demonstrate a unique capability to deliver high-power pulses in a single spatial mode over distances exceeding 200 meters.  相似文献   
7.
Streptococci are one among the major mastitis pathogens which have a considerable impact on cow health, milk quality, and productivity. The aim of the present study was to investigate the occurrence and virulence characteristics of streptococci from bovine milk and to assess the molecular epidemiology and population structure of the Indian isolates using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Out of a total of 209 bovine composite milk samples screened from four herds (A–D), 30 Streptococcus spp. were isolated from 29 milk samples. Among the 30 isolates, species-specific PCR and partial 16S rRNA gene sequence analysis identified 17 Streptococcus agalactiae arising from herd A and 13 Streptococcus uberis comprising of 5, 7, and 1 isolates from herds B, C, and D respectively. PCR based screening for virulence genes revealed the presence of the cfb and the pavA genes in 17 and 1 S. agalactiae isolates, respectively. Similarly, in S. uberis isolates, cfu gene was present in six isolates from herd C, the pau A/skc gene in all the isolates from herds B, C, and D, whereas the sua gene was present in four isolates from herd B and the only isolate from herd D. On MLST analysis, all the S. agalactiae isolates were found to be of a novel sequence type (ST), ST-483, reported for the first time and is a single locus variant of the predicted subgroup founder ST-310, while the S. uberis isolates were found to be of three novel sequence types, namely ST-439, ST-474, and ST-475, all reported for the first time. ST-474 was a double locus variant of three different STs of global clonal complex ST-143 considered to be associated with clinical and subclinical mastitis, but ST-439 and ST-475 were singletons. Unique sequence types identified for both S. agalactiae and S. uberis were found to be herd specific. On PFGE analysis, identical or closely related restriction patterns for S. agalactiae ST-483 and S. uberis ST-439 in herds A and B respectively, but an unrelated restriction pattern for S. uberis ST-474 and ST-475 isolates from herds D and C respectively, were obtained. This signifies that the isolates of particular ST may exhibit related PFGE patterns suggesting detection of a faster molecular clock by PFGE than MLST. Since all the isolates of both the species belonged to novel sequence types, their epidemiological significance in global context could not be ascertained, however, evidence suggests that they have uniquely evolved in Indian conditions. Further research would be useful for understanding the role of these pathogens in bovine sub-clinical mastitis and implementing effective control strategies in India.  相似文献   
8.
Mungbean (Vigna radiata (L.) Wilcz.) is an important leguminous crop cultivated mainly in Asia. Its wild relatives are considered useful genetic resources for mungbean breeding. However, the taxonomic history of mungbean and its wild relatives is complicated and some confusion is still present in recent publications. In this study, we examined the rDNA-ITS sequences and morphological characteristics of 83 gene bank accessions closely related to mungbean. As a result, we classified the 83 accessions into five species and one unclassified accession. The proper taxon name for each species was determined (Vigna grandiflora (Prain) Tateishi et Maxted, Vigna mungo (L.) Hepper, V. radiata, Vigna subramaniana (Babu ex Raizada) Raizada, and Vigna trinervia (Heyne ex Wight et Arn.) Tateishi et Maxted) based on a review of their taxonomic history and morphological comparisons between gene bank accessions and type specimens. A new taxonomic treatment is proposed and a morphological key has been prepared. In this treatment, Vigna radiata (L.) Wilcz. var. setulosa (Dalz.) Ohwi et Ohashi is treated as a synonym of Vigna radiata (L.) Wilcz. var. sublobata (Roxb.) Verdc., and Vigna hainiana Babu, Gopinathan et Sharma is a synonym of V. subramaniana. Accession ‘NI1135’ was revealed to be most closely related to, but is considerably differentiated from, mungbean (V. radiata) based on its rDNA-ITS sequences. It also has distinguishing morphological characters. Plants with similar morphologies and DNA profiles might be distributed in the Indian Himalaya. However, since only one accession is available at present, the taxonomic classification of ‘NI1135’ needs to be reconsidered in the future.  相似文献   
9.
The coronavirus disease 2019 (COVID-19) pandemic has now affected over 72.5 million people worldwide, with nearly 1.6 million deaths reported globally as of December 17, 2020. SARS-CoV-2 has been implicated to have originated from bats and pangolins, and its intermediate animal hosts are being investigated. Crossing of the species barrier and exhibition of zoonosis have been reported in SARS-CoV-2 in farm (minks), domesticated (cats and dogs), and wild animals (tigers, puma, and lions). Recently, the rapid spread of SARS-CoV-2 infection was reported in mink farms, which led to the death of a myriad minks. The clinical and pathological findings of SARS-CoV-2 infection and the rapid animal-to-animal transmission in minks are almost similar to the findings observed in patients with COVID-19. Additionally, the rapid virus transmission among minks and the associated mutations resulted in a new mink-associated variant that was identified in both minks and humans, thereby providing evidence of mink-to-human transmission of SARS-CoV-2. The new mink-associated SARS-CoV-2 variant with a possible reduced sensitivity to neutralizing antibodies poses serious risks and is expected to have a direct effect on the diagnostic techniques, therapeutics, and vaccines that are currently under development. This article highlights the current evidence of SARS-CoV-2 infection in farmed minks, and provides an understanding of the pathogenesis of COVID-19 in minks and the associated zoonotic concerns of SARS-CoV-2 transmission from minks to humans with an emphasis on appropriate mitigation measures and on the necessity of adopting the One Health approach during the COVID-19 pandemic.  相似文献   
10.
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