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31.
为建立雷公藤种植过程中常用农药的残留含量检测方法,采用快速样品前处理结合超高效液相色谱-串联质谱法(quick,easy, cheap,effective,rugged and safe/ultra performance liquid chromatography tandem mass spectrometry,QuEChERS/UPLC-MS/MS)测定雷公藤及根际土壤中辛硫磷、氯氰菊酯和乙基多杀菌素的含量。样品中加入适量的水浸润后用乙腈超声提取,N-丙基乙二胺(PSA)吸附净化,利用优化后的UPLC-MS/MS方法进行检测,基质外标法定量。结果显示,3种农药在根样基质中的检出限(LOD)为0.001~0.714μg/kg,定量限(LOQ)为0.002~2.380μg/kg;在土壤基质中的检出限(LOD)为0.002~0.810μg/kg,定量限(LOQ)为0.006~2.410μg/kg。线性关系、回收率和相对标准偏差均符合农药残留检测的相关规定。结果表明,该方法能满足雷公藤及根际土壤中3种农药残留含量的快速检测要求。  相似文献   
32.
Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF’s mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair.  相似文献   
33.
在全球生态保护和绿色经济发展大背景下,国际林业正处于转型发展的重要时期。了解国际林业发展动态有助于推动中国林业可持续发展。文中介绍了埃塞俄比亚森林资源、林业政策法规、林业机构、林业科研、森林经营、森林保护、林产品贸易等现状,在此基础上总结了埃塞俄比亚林业的特点及导致该国林业发展落后的主要原因。深入了解埃塞俄比亚林业发展落后的现状,分析导致其落后的原因,对于我国林业发展可起到警示作用。  相似文献   
34.
以福建漳州盆栽榕树种植示范基地为观测和试验点,调查分析害螨的为害症状、发生种类和优势种动态时间格局,测定7种药剂对害螨的田间防治效果。结果表明:盆栽榕树种植区的害螨种类有4个科6个属6种,优势种为桔全爪螨;优势种种群动态时间格局分为5类,依次经历发展期、第1高峰期、衰退期、第2高峰期和越冬期。7种药剂对害螨均有一定的防治效果,无药害,15%哒螨灵乳油和73%克螨特乳油对害螨具有较好的速效性,药后1 d防效超过73.00%;11%乙螨唑悬浮剂、24%螺虫乙酯悬浮剂、24%螺螨酯悬浮剂和73%克螨特乳油能持续  相似文献   
35.
为了探索柑橘小实蝇入侵扩散与危害规律,提高其监测与防控水平,2008-2010年应用柑橘小实蝇专用性诱剂和诱捕器,在全市19个镇(街道)35个柑橘园建立监测点进行全市性入侵扩散分布普查;在古城伏龙柑橘园和市区水果市场建立2个系统监测点开展全年种群数量消长监测,结果表明柑橘小实蝇种群入侵扩散与时空分布呈塔型趋势,即以城区为中心,并呈向周边区域扩散蔓延趋势;全年种群时序数量变化主要呈单峰型曲线变化,一般于6月中下旬至7月上中旬初见性诱成虫,8月上旬形成增长拐点,9-10月形成数量高峰, 影响种群数量消长的主要因子有种群基数、气候和生境条件等,从而创建柑橘小实蝇基数(m6)与全年种群诱量(M)关系模型M=23.8339 m6+59.8003(n=6, r=0.9735**)、当旬虫口密度(mn)与其前3个月的旬平均气温(tn-9)关系模型mn=1.9248tn-9-14.88063(n=72, r=0.5123**),以及柑橘挂果期成虫诱量(M)、有虫株率(R%)、有虫果率(P%)、每虫果幼虫量(N)等关系模型:R=0.3667M-1.2746(n=11, r=0.8901**);P=0.0581R+0.3112(n=11, r=0.9649**);N=0.6438P+0.9610(n=11, r=0.7000*)。应用柑橘小实蝇种群入侵扩散危害规律及其参数模型,可反映柑橘园柑橘小实蝇发生变化动态,可随旬作出预报和决策防治,这对提高其监测预警和持续控制具有重要指导意义。  相似文献   
36.
以京海黄鸡为试验材料,采用PCR-SSCP技术,探讨脂联素基因第一外显子和部分第一内含子碱基突变对屠宰和母鸡产蛋性状的遗传效应。结果表明,脂联素基因c.249位C>T突变的3种基因型(AA、AB和BB)对京海黄鸡的活体质量、半净膛率、胸肌质量、腿肌质量、胸肌率和腿肌率差异均不显著(P>0.05)。BB型个体的300日龄产蛋数和66周龄产蛋数显著高于AB型个体(P<0.05)。BB型个体的腹脂质量和腹脂率显著高于AB和AA型个体(P<0.05)。Adipo基因座对京海黄鸡开产日龄,300日龄产蛋数,300日龄蛋质量和66周龄产蛋数的主效应指数(MEI)均小于1.21,而其对公母鸡的腹脂质量主效应指数(MEI)分别为8.68和7.40。说明该基因可能是调控脂肪沉积的主效基因或与主效基因连锁。  相似文献   
37.
马鬃岭自然保护区土壤有机碳分布的研究   总被引:1,自引:0,他引:1  
以安徽省金寨县马鬃岭自然保护区为研究对象,选取56个样点采集土样,分析该区域森林土壤有机碳的时空分布状况。结果表明,该研究区域的土壤有机碳含量随土壤深度、海拔高度、季节的变化而变化。0~20 cm土层有机碳碳平均含量为3.07%,变幅0.94%~15.67%;30~40 cm平均含量为1.98%,变幅0.17%~8.54%;50~60 cm平均含量为1.68%,变幅0.46%~7.81%。有机碳含量随海拔高度升高有增加的趋势,高海拔处有机碳含量稳定,低海拔处变化大,这是由于人类活动影响造成。有机碳含量季节变化显著,秋季含量高于春季,表层季节变化比深层显著。该林区0~20 cm土层碳蓄积量为(8.28~8.31)×105 t,30~40 cm土层碳蓄积量为(5.46~5.73)×105 t,50~60 cm土层碳蓄积量为(4.68~5.33)×105 t。  相似文献   
38.
This study was designed to evaluate the effect of single layer centrifugation (SLC) and subsequent cold storage on stallion sperm capacitation‐like status and acrosome reaction. Three stallions were included in the study, with three ejaculates per stallion. The samples were examined 4, 24 and 72 h after collection, extension and SLC, with storage at 6°C. Sperm capacitation‐like status was investigated using the fluorescent dye chlortetracycline (CTC). There was no difference in capacitation‐like status between colloid‐selected and non‐selected spermatozoa. Sperm motility decreased significantly during cold storage, whereas the proportion of apparently capacitated spermatozoa increased. There was no change in the proportion of acrosome‐reacted spermatozoa. In conclusion, SLC through Androcoll?‐E does not adversely affect the capacitation‐like status of stallion spermatozoa, although it did increase with time during cold storage.  相似文献   
39.
Reasons for performing study: Disturbances in skeletal development, primarily osteochondrosis (OC) and palmar/plantar osseous fragments (POF), have been commonly reported as problems in young horses. However, there are few reports of such findings for epidemiological analyses or breeding purposes. Objectives: To evaluate equine hospital data as a possible source of information for genetic evaluations by estimating prevalence and heritability of OC in the stifle, hock and fetlock joints and of POF in the fetlock. Methods: Data on Swedish Warmblood (SWB) horses were obtained from a large equine hospital in south Sweden. Prevalences were based on radiographic examinations of 879 screened horses, mainly evaluated as part of a prepurchase examination and 3639 horses with a reported history of orthopaedic problems. For the heritability study the 2 data sources were pooled and 3199 examined horses with pedigree information were considered for the linear animal model analyses. Results: The overall prevalence of OC was 13% (stifle 9%, hock 6% and dorsal osseous fragments in fetlock [DOF] 10%) and POF 10%. The overall heritability of OC was 0.05 on the visible binomial scale. The corresponding heritabilities for OC in the stifle were 0.03, hock 0.08, DOF 0.10 and POF 0.13. These values correspond to heritabilities of 0.09–0.38 on the underlying quantitative scale. Conclusions and potential relevance: Obtained prevalences and heritabilities were in accordance with other studies, supporting the hypothesis that data regularly obtained from equine hospitals may be a valuable source in studies of inherited disorders such as OC and POF. There is a need for more standardised documentation of diagnoses and consistent recording of identity of examined horses using passports or breed databases. Compilation of results from major clinics is desired in order to cover most progenies of stallions used in a region or nation.  相似文献   
40.
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