首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 93 毫秒
1.
SARS-CoV假病毒中和试验技术的建立及评价   总被引:1,自引:1,他引:0  
为避免传统的SARS病毒中和试验需要操作活毒而存在的生物安全隐患,建立了基于假病毒系统、操作较安全的SARS中和试验技术平台。本研究应用高效表达SARS-CoV S(密码子优化的全长S蛋白,简称S)的真核表达载体(pVRC8304),与HIV慢病毒包装质粒(p CMV△8.2)及转移质粒(pHR′CMV EGFP)3个质粒载体系统共同转染人胚肾细胞293T,包装了SARS假病毒;通过SARS假病毒感染的RD-A细胞中标记基因EGFP表达的分析,确定SARS假病毒能有效进入细胞,建立了可在BSL-2级实验室操作的SARS病毒中和试验技术平台。用该技术平台对不同免疫血清进行了中和抗体分析,并比较了基于假病毒和基于SARS活病毒的中和试验效果。结果显示:SARS假病毒和SARS活病毒两个中和试验系统获得中和抗体滴度变化趋势一致,表明本研究构建的SARS假病毒可替代SARS活病毒用于建立操作上安全的SARS病毒中和试验技术平台。  相似文献   

2.
运用双重组合设计建立黑龙江省玉米降水产量模型   总被引:1,自引:0,他引:1  
本文运用旋转设计进一步发展的双重组合试验设计,建立黑龙江省关于降水、有机质、氮、磷、钾肥及有机肥的玉米产量模型,探讨了双重组合试验设计在建模时用可控因素去挂接不可控因素的应用,对模型进行了检验和频数分析,提出玉米产量大子3000公斤的高产在艺措施.  相似文献   

3.
针对朵椒引种栽培中存在的关键技术难题,开展了种子处理方法、育苗密度、苗木控制措施等试验,为朵椒的规模化人工栽培奠定了技术基础。  相似文献   

4.
糖胶树育苗造林技术   总被引:1,自引:0,他引:1  
总结报导了糖胶树在临沧耿马大洪山林场和临翔区两地育苗和造林试验技术总结,包括了采种时期、种子千粒重、场圃发芽试验、苗木生长量、造林地选择、造林时间和方法等7个方面的技术措施.  相似文献   

5.
《生物产业技术》2011,(4):97-97
知名专家倾力打造,临床试验实践必备参考书。 中国药学会理事长桑国卫、协和医院主任医师、北京大学第一医院教授联袂推荐。 本书全面阐述了药物临床试验管理和操作的方法细节,涉及各期、各类药物临床试验全过程的管理和设计细节,详尽阐述了临床试验项目的实际技术操作手段和核心程序,对操作规范要点和方法讲解透彻。  相似文献   

6.
羟基磷灰石生物安全性试验研究   总被引:2,自引:0,他引:2  
为了评价羟基磷灰石的生物安全性,依据相关的医疗器械行业标准和GB/T16886系列标准,对该材料进行了迟发型超敏反应试验、热原试验、急性全身毒性试验、细胞毒性试验等一系列生物安全性试验,并对试验数据进行了分析评价,结果表明,羟基磷灰石具有良好的安全性。  相似文献   

7.
蛇腐皮病的病原特性及其防治方法的研究   总被引:1,自引:0,他引:1  
目的:对广西驯养珍稀蛇类腐皮病病原菌的特性进行研究,并对疾病有效的防治措施进行探索。方法:对蛇类腐皮病的5种主要病原菌进行药敏感试验,小白鼠接种试验、本动物回归试验,常用消毒剂的体外杀菌试验,以及对蛇场采场的综合性防治措施。结果:药敏试验表明:除绿脓杆菌外,其它蛇类腐皮病病原菌均对头孢唑啉有高度的敏感,对丁胺卡那霉素,10株菌均有不同程度的敏感,小白鼠接种试验表明:接种后24h内,变形杆菌、绿脓杆菌和腐败假单胞杆菌对小白鼠致死率为100%(各为4/4),雷极普鲁威登斯菌致死率为25%(1/4),金黄色葡萄球菌致死率为0%(0/4);本动物回归试验表明:5种主要病原菌在皮肤创口接种后20天内,均可诱发腐皮病,从皮肤化脓灶及尾血均分别分离到接种菌;常用消毒剂体外抑菌试验表明,百毒杀、来苏儿、新洁尔灭对10株细菌的杀菌率均在99.9%以上,特别是百毒杀低浓度下杀菌效果尤为明显;蛇场采取综合性防治措施后,蛇腐皮病发病率由20%减少到10%以下,死亡率由10%减少到5%以下。结论:本研究的结果证明,蛇腐皮病的主要病原是变形杆菌、绿脓杆菌、腐败假单胞菌、协极普鲁威登斯菌、金黄色葡萄球菌;5种病原菌的抗药性均比较强,仅对丁胺卡那霉素、头孢唑啉有广泛的敏感性,丁胺卡那霉素、头孢唑啉为治疗蛇腐皮病的首选药物。百毒杀、来苏儿、新洁尔可作为防治蛇腐皮病的消毒剂。此外还需要采用取综合性措施才能有效地控制蛇腐皮病的发生及危害。  相似文献   

8.
用离子束增强沉积 (IBED)方法 :即在氧气氛中 ,通过惰性气体Xe+离子轰击和Ti的电子束蒸发进行了氧化钛薄膜的合成 .X射线衍射分析表明 ,用离子束增强沉积技术合成的薄膜为金红石结构 ,具有 ( 10 0 )择优取向 .用背散射技术分析了薄膜的成分 ,发现薄膜的O/Ti基本上接近 2∶1.薄膜中含有一定量的Ti2 +和Ti3+.体外试验及动物体内试验结果表明 ,金红石型氧化钛薄膜具有比目前临床应用的热解碳更好的血液相容性 .并认为 ,金红石型氧化钛覆膜热解碳极可能成为新的人工心脏瓣膜材料 .  相似文献   

9.
试验设计中的重复试验次数的确定   总被引:2,自引:1,他引:1  
研究单因素、双因素的方差分析,提出因素水平差异显著与否,主要取决于试验效应的平方和(或试验效应方差)与随机误差.引入平均相对试验效应,在其已知前提下,给出保证一定概率的因素水平差异显著的最小总试验次数、或每水平的最小平均重复试验次数.  相似文献   

10.
目的:以马铃薯渣为原料,探究提取马铃薯渣中膳食纤维的最佳工艺条件。方法:通过生物法 酶法、超声波裂解、高速剪切等技术提取马铃薯渣中所含的膳食纤维,通过单因素试验和正交试验分析试验数据。 结果:提取膳食纤维的最佳工艺条件为酶解pH为5、酶解温度45℃、酶添加量30U/g、酶解2.5h。结论:本研究膳食纤维的提取率达25.87%,并测得持水力和膨胀力分别为7.1g/g、7.5mL/g,该工艺条件可有效提取马铃薯渣中的膳食纤维。  相似文献   

11.
均匀设计试验布点方案在苗圃地土壤施肥研究中应用初探   总被引:1,自引:0,他引:1  
本文通过对最优混合设计和均匀设计两个肥效试验的分析,讨论了均匀设计试验布点方案在苗圃地土壤施肥研究中应用的可行性及其条件。  相似文献   

12.
A study was conducted to examine nursery protocols for production of planting stocks used in wetland mitigation projects. Two commercial soil mixtures were tested along with waterlogging, fertilization, and combination treatments. Two marsh species, Panicum hemitomon and Sagittaria lancifolia, were subjected to a two‐phase study. During Phase I, watering and fertilization treatments were applied in a 2 × 2 × 2 factorial design with two soils, two watering regimes, and two fertilizer treatments. In Phase II, all plants were subjected to continuous waterlogging (no fertilizer). Soil redox potential was measured, along with plant gas exchange and growth responses. Our data do not support the hypothesis that flood “pre‐conditioning” alone can significantly improve plant growth under subsequent flooding. However, fertilization alone or in combination with flooding appeared to enhance shoot and root production in both species during the subsequent flooding. In contrast, flooding alone produced Panicum plants that appeared to remain somewhat susceptible to subsequent flooding as compared to fertilized plants. Sagittaria plants subjected to fertilizer treatment alone did not produce significantly greater total dry weights compared to their controls. Our data indicate that the growth of planting stocks for wetland mitigation can be improved by fertilization in the nursery. Key words: fertilizer, flooding, nursery production, wetland mitigation.  相似文献   

13.
双季晚稻田大面积放养固氮蓝藻的试验   总被引:1,自引:0,他引:1  
通过晚稻田大面积放养固氮蓝藻试验,我们初步提出了土池大量培养和茬口田大面积生产藻种等一系列的培养和生产藻种的技术措施;生产了30吨的鲜藻种接种到晚稻田中。经过加强管理,先锋大队990亩晚稻田全部养藻化。接种的藻生长旺盛,平均产量达到1000斤/亩以上。抽样测产估计,晚稻田中鲜藻量达到500吨。晚稻田养藻使水稻增产约10%,个别达到20%以上。因此,晚稻田放养固氮蓝藻为晚稻开辟了新的有希望的肥源。    相似文献   

14.
山桃山杏苗木耗水特性研究   总被引:3,自引:0,他引:3  
在不同土壤水分条件下,研究了苗木定植后耗水特性。结果表明:两个树种耗水特性很接近,只是在严重干旱下两者才表现出差异,由于生物产量的差异,使其耗水系数相接近。  相似文献   

15.
台湾桤木和四川桤木种源苗木对水分胁迫的生理响应   总被引:10,自引:0,他引:10  
采用PEG6000,研究了4种台湾桤木种源和2种四川桤木种源苗木对水分胁迫的生理响应。结果表明:(1)随着水分胁迫强度增加,叶片质膜相对透性增大,四川桤木种源质膜透性比台湾桤木种源增加幅度大。(2)在轻度的水分胁迫下,6个种源SOD活性均呈上升趋势,POD活性的增加只发生在PEG10%的水分胁迫强度以内,轻度水分胁迫下,MDA含量上升幅度小于重度胁迫强度;在PEG30%胁迫处理时,台湾桤木叶片MDA含量平均上升30.22%,而四川桤木上升了40.44%,表明台湾桤木种源膜脂过氧化程度较四川桤木种源轻,受害程度相对要小一些。(3)水分胁迫下,叶片脯氨酸含垃均有不同程度的增加.在PEG20%水分胁迫处理下,各种源脯氨酸积量增加的幅度为:台湾桤木苗栗种源(AF2)(68.9%)〉台湾桤木福建南平种源(AF4)(60.2%)〉台湾桤木台东种源(AF2)(54.7%)〉台湾桤木台中种源(AF1(47.6%)〉四川桤木广元种源(AC2)(39.7%)>金堂种源(AC1)(39.1%)。水分胁迫条件下,叶片可溶性糖含量呈下降趋势。6种种源苗木在水分胁迫条件下,由于脯氨酸的积累,有一定的渗透调节能力,但这种渗透调节能力又是十分有限的。(4)采用隶属函数法,对各种源的抗旱生理进行综合评价,其耐旱牛理强弱的顺序是:AF2、AF1、AF3、AF4、AC2、AC1,台湾桤木比四川桤木具有较强的耐旱生理适应性。从耐旱生理角度讲,凡是适合四川桤木生长的区域,基本上亦适合台湾桤木,在引种载培中,应选择抗旱性稍强一些的台湾桤木苗栗种源和台中种源。  相似文献   

16.
《PloS one》2015,10(3)
The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem approach to fisheries management and with the requirements of the Marine Strategy Framework Directive to maintain or achieve seafloor integrity and good environmental status.  相似文献   

17.
Nothofagus alessandrii is an endemic and endangered species from the Maule Region of Central Chile. The forests it once dominated have been severely degraded and fragmented by human activities, and it is estimated that only 350 ha remain. Yet, available information for propagation and nursery plant cultivation of this species is conspicuously lacking. Future efforts to restore this ecosystem type will rely, in large part, on advancing the capacity to propagate and cultivate this highly threatened species. To this end, we studied the response (germination process and nursery growth) of viable seeds of N. alessandrii to different pre‐germination treatments, sowing times, and slow‐release fertilizer. The highest germination percentages were obtained with cold stratification for periods of 30 and 45 days (84.9 and 82.6%, respectively). Sowing time was also relevant, with seeds obtaining highest germination rates (53%) when sowing during spring season (September) as well as the best growth rates. Both cold stratification and GA3 treatments can provide adequate germination percentage and similar seedling quality. After one nursery season, no clear effect of slow‐release fertilizer on plant growth was observed. The results of this study provide important baseline information for propagation and nursery techniques for restoration programs of N. alessandrii.  相似文献   

18.
浙江天童常绿阔叶林演替系列优势种光合生理生态的比较   总被引:30,自引:5,他引:25  
丁圣彦  宋永昌 《生态学报》1999,19(3):318-323
研究了浙江天童国家森林公园常绿阔叶林次生演替系列中主要优势种幼苗,幼树及成年树的生理生态学,发现优势种幼苗的更新一方面与其自身的生物生态学特性,种子的来源,萌发力和群落的生境有关,另一方面也与幼苗的光补偿点有关,优势种成年树在常绿阔叶林演替系列中地位的变迁与相互间的更替主要与其物质的合成能力,即优势种的光合作用速率有关。  相似文献   

19.
Agricultural activities have been expanding globally with the pressure to provide food security to the earth's growing population. These agricultural activities have profoundly impacted soil organic carbon (SOC) stocks in global drylands. However, the effects of clearing natural ecosystems for cropland (CNEC) on SOC are uncertain. To improve our understanding of carbon emissions and sequestration under different land uses, it is necessary to characterize the response patterns of SOC stocks to different types of CNEC. We conducted a meta-analysis with mixed-effect model based on 873 paired observations of SOC in croplands and adjacent natural ecosystems from 159 individual studies in global drylands. Our results indicate that CNEC significantly (p < .05) affects SOC stocks, resulting from a combination of natural land clearing, cropland management practices (fertilizer application, crop species, cultivation duration) and the significant negative effects of initial SOC stocks. Increases in SOC stocks (in 1 m depth) were found in croplands which previously natural land (deserts and shrublands) had low SOC stocks, and the increases were 278.86% (95% confidence interval, 196.43%–361.29%) and 45.38% (26.53%–62.23%), respectively. In contrast, SOC stocks (in 1 m depth) decreased by 24.11% (18.38%–29.85%) and 10.70% (1.80%–19.59%) in clearing forests and grasslands for cropland, respectively. We also established the general response curves of SOC stocks change to increasing cultivation duration, which is crucial for accurately estimating regional carbon dynamics following CNEC. SOC stocks increased significantly (p < .05) with high long-term fertilizer consumption in cleared grasslands with low initial SOC stocks (about 27.2 Mg ha−1). The results derived from our meta-analysis could be used for refining the estimation of dryland carbon dynamics and developing SOC sequestration strategies to achieve the removal of CO2 from the atmosphere.  相似文献   

20.
Casuarina equisetifolia Forst. is a tree crop that provides fuel wood, land reclamation, dune stabilization, and scaffolding for construction, shelter belts, and pulp and paper production. C. equisetifolia fixes atmospheric nitrogen through a symbiotic relationship with Frankia, a soil bacterium of the actinobacteria group. The roots of C. equisetifolia produce root nodules where the bacteria fix atmospheric nitrogen, which is an essential nutrient for all plant metabolic activities. However, rooted stem cuttings of elite clones of C. equisetifolia by vegetative propagation is being planted by the farmers of Pondicherry as costeffective method. As the vegetative propagation method uses inert material (vermiculite) for rooting there is no chance for Frankia association. Therefore after planting of these stocks the farmers are applying 150 kg of di-ammonium phosphate (DAP)/acre/year. To overcome this fertilizer usage, the Frankia-inoculated rooted stem cuttings were propagated under nursery conditions and transplanted in the nutrient-deficient soils of Karaikal, Pondicherry (India), in this study. Under nursery experiments the growth and biomass of C. equisetifolia rooted stem cuttings inoculated with Frankia showed 3 times higher growth and biomass than uninoculated control. These stocks were transplanted and monitored for their growth and survival for 1 year in the nutrient-deficient farm land. The results showed that the rooted stem cuttings of C. equisetifolia significantly improved growth in height (8.8 m), stem girth (9.6 cm) and tissue nitrogen content (3.3 mg g?1) than uninoculated controls. The soil nutrient status was also improved due to inoculation of Frankia.  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