排序方式: 共有60条查询结果,搜索用时 15 毫秒
51.
将新城疫病毒(NDV)F48E9株融合蛋白(F)基因1700 bp克隆到真核表达载体pcDNA3中,构建成表达F基因的载体pc3F.然后将包含F基因及其上游的细胞巨化病毒启动子和增强子的3800 bp DNA片段再克隆入包含火鸡疱疹病毒(HVT)非必须片段载体pTK2B中,构建成功含有F基因表达盒的HVT转移质粒载体pTK3F.经限制性内切酶酶切分析,F基因表达盒的插入方向与pTK2B中TK基因转录方向一致.该研究为进一步在细胞中转染并获得表达F基因的HVT重组病毒奠定了基础. 相似文献
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Prinz Parungao Magtulis 《国际公共行政管理杂志》2017,40(11):954-967
Unlike corruption, government size has not been studied in the Philippines despite numerous literature suggesting relationship between the two. This study fills that gap by looking at state spending and how it relates to the enduring political issue of public corruption. Findings suggest that, contrary to expectations, bigger disbursements actually improve public’s perception of bureaucratic corruption, similar to the effect of better institutions and rule of law. 相似文献
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为研制FMD复制缺陷型腺病毒活载体疫苗,通过RT-PCR方法获得了O型口蹄疫病毒(FMDV)全开放阅读框(ORF)基因片段,将其克隆到pMD18-T载体后测序,再将ORF编码基因定向克隆入腺病毒穿梭载体pAdTrack-CMV中,构建了重组腺病毒穿梭质粒。经PCR、酶切及测序鉴定,所克隆的ORF编码基因序列与原始强毒株Akesu/58的ORF编码基因比较,L、P1、P2、P3基因的核苷酸同源性分别为98.8%、97.9%、99.0%和97.6%,PCR、酶切鉴定重组腺病毒穿梭质粒均获得了长约6.9 kb的目的基因片段。表明,成功获得了含有O型FMDV全ORF编码基因的阳性克隆,并成功构建了含有完整FMDV开放阅读框架的编码基因表达盒的重组腺病毒穿梭质粒。 相似文献
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It is now extremely easy to recapture high-resolution and high-quality images from LCD (Liquid Crystal Display) screens. Recaptured image detection is an important digital forensic problem, as image recapture is often involved in the creation of a fake image in an attempt to increase its visual plausibility. State-of-the-art image recapture forensic methods make use of strong prior knowledge about the recapturing process and are based on either the combination of a group of ad-hoc features or a specific and somehow complicated dictionary learning procedure. By contrast, we propose a conceptually simple yet effective method for recaptured image detection which is built upon simple image statistics and a very loose assumption about the recapturing process. The adopted features are pixel-wise correlation coefficients in image differential domains. Experimental results on two large databases of high-resolution, high-quality recaptured images and comparisons with existing methods demonstrate the forensic accuracy and the computational efficiency of the proposed method. 相似文献
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《国际相互影响》2012,38(2):182-217
In this study, we utilize the growth rate of gross domestic product as the threshold variable to construct two nonlinear threshold vector autoregression models to re-examine the findings in Yan (2007:23) that “current account imbalance causes capital mobility in developed countries; capital mobility causes current account imbalance in emerging countries.” The nonlinear causality test shows that the findings of Yan (2007) can exist only in certain regimes and the primary factor that affects the causality between current account and financial account (and its components of foreign direct investment, portfolio investment, and other investment) is the asymmetry caused by the business cycle. 相似文献
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为构建鸡白痢沙门氏菌C79-13株Δcrp基因缺失突变株,并初步观察ΔcrpC79-13缺失菌株作为活疫苗对雏鸡的免疫活性,将含缺失320bp crp基因的重组自杀性质粒pREΔcrp与C79-13进行接合转移,两步法筛选出无抗性标记的ΔcrpC79-13缺失菌株;通过半数致死量测定其毒力;给4日龄雏鸡口服免疫缺失菌株,在不同时间点根据胸腺、法氏囊、脾等免疫器官发育和平均日增重、外周血淋巴细胞转化试验、Griess法NO测定及血清IgG动态观察免疫水平。结果显示ΔcrpC79-13的毒力较C79-13降低约99.6%(LD50>5.0×109CFU);雏鸡接种ΔcrpC79-13(1.0×109 CFU/只)后不影响雏鸡生长,第14~21天体内特异性细胞和体液免疫水平达到最高。表明成功构建了减毒鸡白痢沙门氏菌ΔcrpC79-13株,其毒力显著降低,免疫雏鸡安全,具有良好的免疫活性。 相似文献
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This study examines the international information transmission among three major gold futures markets namely New York Mercantile Exchange in division of Commodity Exchange (COMEX), Multi Commodity Exchange (MCX), and Tokyo Commodity Exchange (TOCOM). The main concept of this research is no matter where gold futures traded, they share the same underlying asset. Two well-documented approaches, which are vector error correction model and information share, are utilized to measure the process of price discovery under this trivariate system. The uniqueness of this study is that it employs synchronous intraday time series which can mitigate the stale price problem from daily observations. The evidences indicate that the three gold futures prices are cointegrated and driven by the same fundamental factors. New arrival information disseminates efficiently among the three markets and the pricing information transmission among exchanges is very rapid. However, the lead-lag relationship among markets still exists with the dominance of COMEX gold futures as the centre of price discovery The US gold futures market is the most efficient in processing information. Its role on price discovery and information can be attributed to COMEX's massive trading volume. 相似文献
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为了解禽流感新型疫苗的研究现状,从载体选择和候选基因等方面论述了基因重组活载体疫苗和表位疫苗的研究进展,并对这两种疫苗的发展前景进行了展望,以期为禽流感新型疫苗的研究提供参考。 相似文献
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