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   28篇
  免费   0篇
林业   10篇
农学   1篇
  5篇
综合类   1篇
农作物   4篇
畜牧兽医   7篇
  2021年   1篇
  2020年   1篇
  2018年   1篇
  2014年   1篇
  2013年   2篇
  2012年   1篇
  2011年   3篇
  2009年   1篇
  2008年   2篇
  2007年   3篇
  2006年   4篇
  2005年   4篇
  2004年   1篇
  2003年   2篇
  1997年   1篇
排序方式: 共有28条查询结果,搜索用时 15 毫秒
21.
The liver consists of parenchymal hepatocytes and non-parenchymal cells. Non-parenchymal cells, Kupffer cells, hepatic stellate cells and cholangiocytes have crucial roles in liver homeostasis and liver pathology. To establish baseline data, this study investigated immunohistochemically the distribution of non-parenchymal cells in perivenular areas (PV), periportal areas (PP) and Glisson's sheath (GS) of adult rat liver. Liver tissues were collected from the left lateral lobe of rats. CD163-positive macrophages were seen along the sinusoid of PV and PP areas, indicating Kupffer cells. Double immunofluorescence showed, Kupffer cells partly co-expressed CD68 and MHC class II antigens in the liver. The numbers of Kupffer cells were significantly high in PP areas as compared with PV or GS areas. CD68-positive exudative macrophages were highly localized in PP and GS areas and a comparatively low PV area. MHC class II-positive dendritic cells (activated macrophages) were localized mainly in GS. Granzyme B-positive NK cells were mainly localized in the Glisson's sheath. CD3-positive T cells and CD20-positive B cells were distributed along the sinusoids of the PP and PV areas of hepatic lobules. Vimentin and glial fibrillary acidic protein (GFAP)-positive hepatic stellate cells were localized along sinusoids in the hepatic lobules of the liver. Cholangiocytes reacting to cytokeratin 19 were seen on interlobular bile ducts in Glisson's sheath of the liver. This study shows that heterogeneous macrophage populations, liver-resident lymphocytes and hepatic stellate cells localized in PP and PV areas or GS areas of the liver with cells specific patterns.  相似文献   
22.
The organic carbon storage in trees and organic carbon flow with geoposition of trees was estimated in the forest area of Chittagong (South) Forest Division within geo-position 91°47′ and 92°15′ East longitude and 21°45′ and 22°30′ North latitude. The study was conducted through stratified random sampling by identifying each sampling point through Global Positioning System (GPS). It was found that above ground organic carbon storage (t/hm^2), below ground organic carbon (t/hm^2) and total biomass organic carbon (t/hm^2) was respectively the highest in Dipterocarpus turbinatus (Garjan) (7.9, 1.18 and 9.08 t/hm^2) followed by Tectona grandis (Teak) (5.66, 0.85 and 6.51 t/hm^2), Artocarpus chaplasha (Chapalish) (2.32, 0.34 and 2.66 t/hm^2), Artocarpus lacucha (Batta) (1.97, 0.29 and 2.26 t/hm^2) and Artocarpus heterophyllus (Jackfruit) (1.7,0.25 and 2.26 t/hm^2). From the study it was revealed that organic carbon stock was the highest (142.7 t/hm^2) in the geo-position 22° Latitude and 92° Longitude and was the lowest (4.42 t/hm^2) in the geo-position 21° 50′ Latitude and 92° 2.5′ Longitude. The forest of the study area is a good reservoir of organic carbon so has a good capacity to sequester organic carbon from the atmosphere. Sustainable forest management may help to sequester more organic carbon so that economic benefit for the country and environmental benefit in the international arena are possible from the study area.  相似文献   
23.
River basin management has become more dynamic and challenging due to increased competition among different water use sectors. Mae Klong Basin is rich in term of water availability, but increasing water demands in future due to inter-basin-based water management policy addressed by the national government may strongly influence the changes in water status. WEAP model was implemented to assess the current water supply and demand situations for this basin. Six different scenarios were established to evaluate the response of the basin to increasing demands under two SRES scenarios A2 and B2. The simulated results have shown that currently the water resources in the basin are sufficient to meet the existing needs in the wet season, but water shortage has occurred in the dry periods of 2014 and 2015 due to less rainfall in these years. The results have also shown that more water shortages have occurred under A2 scenario as compared to B2 scenario. Water shortages have occurred in all the developed scenarios indicating that the basin will face water scarcity particularly in the scenario five where transferring water to the adjoining area is difficult to possibly be implemented. The scenario six where a new hydropower project is proposed is considered feasible under both A2 and B2 scenarios and can help in meeting hydropower demands in the basin. It is pertinent to shape more effective policies and regulations in the basin for effective water resources management in reducing water shortage as well as achieving downstream water needs and power benefit in future.  相似文献   
24.
Globally, trade in agar-based products is growing rapidly due to their recent adoption as an ingredient in the cosmetics and pharmaceuticals sector. In Bangladesh, people living in some north-eastern districts have been engaged in the production, processing and trading of such products for several decades. These practices, which they consider as the lifeblood of their existence, have been inherited from their ancestors. This paper reports a case study carried out in Maulvibazar district exploring the production and marketing, and industry problems, of agar-based enterprises and their potential contribution to socio-economic development. An exploratory survey was undertaken over 30 randomly selected agar-based factories during December 2005–April 2006, with entrepreneurs of the factories personally interviewed using a semi-structured questionnaire. The majority of the factories of the area were found to depend on local sources of raw materials to produce agar-based products. About 514 full and part-time workers are employed in the factories. Average annual expenditure, revenue and net annual income per factory for three consecutive years 2003–2005 of the study were estimated as Tk 63,980, Tk 111,414 and Tk 47,435, respectively, being highest where attar (agar oil) of superior grade was produced for export. There appears to be a sustainable source of raw materials, availability of technical and financial assistance and opportunity for expansion of market facilities to secure the maximum benefit achievable from this highly promising industry.
Sharif A. MukulEmail:
  相似文献   
25.
Considerable progress has been made on the genetic engineering of rice for improved nutritional content involving micronutrients and carotenoid content. Golden Rice, developed by genetic engineering (Agrobacterium and biolistic transformation) was used in rice breeding for the transfer of high-nutritional value to the local rice cultivars. Simultaneously, commercial Asian indica rice cultivars were also developed with expression of high-carotenoid levels. The lines were developed based on POSITECH (PMI) selection system or made marker free by segregating out the marker gene from the gene of interest. Anther culture was used to develop the homozygous stable lines, which could be of much use in further introgress-breeding and in farmer’s field. Enhanced carotenoids levels (up to T3 generation) were observed in a number of lines compared to the T0-T1 seeds which could be due to transgeneration effect of growing under greenhouse versus field conditions. However, a few introgressed lines showed less carotenoid levels than the original lines used in the breeding process. Agronomic performance of introgressed lines, non-transgenic controls, and transgenic golden rice (IR64 and BR29) developed at IRRI showed acceptable and comparable data under identical limited field conditions (screenhouse data). Syngenta generated a new Golden Rice (US cultivar) containing high level of carotenoids grown in the field at Louisiana, USA is expected to be available to the public domain. Incorporation of genes for carotenogenesis in seeds by transgenesis or by introgression did not change any significant agronomic characteristics in rice plants. The ongoing and future study of bioavailability, quality, larger field testing and freedom to operate will ensure the benefit of Golden Rice to the people who need them most.  相似文献   
26.
The present study evaluated the effects of infected culture supernatant of erythrocytes, fractionation of culture supernatant and serum from dogs infected with Babesia gibsoni (B. gibsoni) on the maturation of canine reticulocytes in vitro. The SDS-PAGE demonstrated that significantly broader bands were generated by both the infected culture supernatant of erythrocytes and the serum from dogs chronically infected with B. gibsoni. The culture supernatant of erythrocytes infected with B. gibsoni strongly suppressed the maturation of reticulocytes. Prior studies showed that chronically infected serum had inhibitory effects on both the maturation of reticulocytes and the canine pyrimidine 5''-nucleotidase subclass I and purine-specific 5''-nucleotidase activity. In addition, serum free infected culture supernatant of erythrocytes had an inhibitory effect on the morphological maturation of reticulocytes. These results suggest that infected serum and culture supernatant of erythrocytes might accumulate excess proteins and/or metabolites as a result of the inhibited maturation of reticulocytes and decreased activity of erythrocyte 5''-nucleotidase. Furthermore, the fractions observed at >150 kDa- and 150-70 kDa- in the infected culture supernatant and serum retarded the maturation of canine reticulocytes in vitro. The results obtained from the in vitro examinations, in the present study, suggested that B. gibsoni itself and/or its metabolites might release certain proteins in the infected culture supernatant and serum from infected dogs and as a result delay morphological maturation of canine reticulocytes.  相似文献   
27.
Abnormal early ripening (AER), a major constraint on wheat production in Western Japan, manifests as sudden leaf senescence shortly after anthesis and results in poor grain filling; this leads to smaller grains and reduced grain yield. It is suggested that overwetting of the soil may be related to AER. We conducted field experiments over 2 seasons (2008-2009 and 2009-2010) in Yamaguchi, Western Japan, with waterlogging treatment using 2 Japanese wheat cultivars, Daichinominori (Western Japanese cultivar) and Haruyutaka (Hokkaido cultivar), which differ in terms of grain growth in the environment of Western Japan. We imposed pre-anthesis waterlogging for 2 weeks in 2008-2009 and post-anthesis waterlogging throughout the grain-filling period in 2009-2010. Pre-anthesis waterlogging had no significant effect on grain yield or grain filling irrespective of cultivar. Post-anthesis waterlogging severely reduced the grain yield by 44% and 36% in Haruyutaka and Daichinominori, respectively. The yield loss was attributable to the smaller grain weight that was a result of slower grain growth rate later in the shortened grain-filling period. Post-anthesis waterlogging induced sudden leaf senescence 1 and 2 weeks after anthesis in Haruyutaka and Daichinominori, respectively, and drastically reduced the photosynthesis and ultimately dry mass accumulation. It also depressed the remobilization of water-soluble carbohydrates (WSCs) from culms to grains leaving more residual WSCs in the culms at harvest (149 and 65 mg g−1 DW in waterlogging and controls, respectively). The results indicate that the reduced grain growth due to waterlogging was attributable to decreased current assimilation and poor remobilization of culm WSCs to grain similar to that in AER plants. These results suggest that injured root function after anthesis might induce early leaf senescence and poor grain filling similar to AER wheat.  相似文献   
28.
采用分阶段抽样方式对大港市藤家具企业的经济效益进行调查.根据总投资将企业分为大型、中型和小型三类.大部分的企业(55%)已有40-50年的历史,仅有18.33%的企业历史超过50年.在小型和中型企业中,具有大学毕业文凭的企业家只占8.33%, 而大型企业的大学毕业者占18.33%.大部分企业(45%)属于小型企业,66.67%的工人经过技术培训.7种商品是藤类制品并有16种尺寸,如沙发(45 cm ( 45 cm, 50 cm ( 50 cm and 55 cm ( 55 cm), 配套餐桌(4把椅子,1个桌子,或6把椅子1个桌子),床(1 m ( 2m, 1.3 m ( 2.3 m and 1.5 m ( 2.3 m),椅子(45cm(45cm and 50cm(50cm),摇椅(大、中、小)等.在所有大型、中型和小型企业中,以生产椅子最多,床最少.大型藤家具企业的总净收益和收益造价比(1:16)最高.  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