373 research outputs found
Corporation Collection Management and Client Credit Evaluation
随着国民经济的不断发展,产品供过于求和买方市场的迅速形成,决定了企业必须通过赊销方式提高产品销售额,扩大市场占有率。应收账款在企业资产中的比例迅速提高,应收账款管理就成为企业管理的重要部分。应收账款管理实质上就是客户的信用管理,客户信用管理的前提是如何做好客户的信用评价。 本文共分为六章。 第一章从H电子公司案例分析企业应收帐款形成的原因,阐述应收帐款的成本以及过量的应收帐款所带给企业的风险,探讨了应收帐款的管理实质上就是如何做好企业的客户信用管理。 第二章做好企业的客户信用管理,首先了解我国信用环境与企业信用管理现状及信用缺失的危害性,分析加强企业信用管理的现实意义,分析发达国家和地区...Along with the development of countries economic, product supply morn then request and speedy form buyer’s market decide corporate must via an account sale to advance sales, to enlarge marketing occupancy rate. The collection in the corporate capital scale is rapidly increasing. Collection management turns into enterprise managing substantial. In fact, collection management is a client credit admi...学位:工商管理硕士院系专业:管理学院工商管理教育中心_工商管理硕士(MBA)学号:X200015103
文昌鱼中一个2A肽介导的多基因表达载体构建
2A肽(P2A)介导的多基因表达载体具有高裂解活性且上、下游基因等摩尔表达等优点,已广泛应用于动物转基因研究.文昌鱼(amphioxus)作为一种新兴的模式动物,尚无应用这种表达载体的报道,为此在pXT7转录系统基础上构建一个P2A介导的多基因表达载体.将体外转录的P2A介导的mRNA注入文昌鱼卵细胞并受精后,经激光共聚焦显微镜和蛋白质免疫印迹(Western blot)检测表明,该mRNA在文昌鱼胚胎中能够高效地翻译和剪切,并且在信号肽的作用下eGFP蛋白定位于细胞核中,而mCherry蛋白定位于细胞膜上,上、下游蛋白间的剪切效率达到91%;进而构建了由文昌鱼热激蛋白基因启动子(BbHsp70)启动,并由P2A介导的多基因表达载体,实验证明其在热诱导和上、下游蛋白剪切方面均达到了预期效果.国家自然科学基金(31372188,31471986,31672246
Establishment of a nude mouse model of glioma orthotopic xenograft with double-fluorescent labeling
目的建立一种稳定、可实时监测的胶质瘤原位移植瘤裸鼠模型。方法用带有荧光素酶(luciferase-Luc)和绿色荧光蛋白(green fluorescent protein-GFP)基因的慢病毒感染U251神经胶质瘤细胞,流式细胞仪筛选稳定表达GFP-Luc荧光的细胞系,并通过CCK-8实验、细胞周期实验、Transwell肿瘤迁移及侵袭实验等评价荧光细胞的增殖、迁移和侵袭能力是否改变;将细胞接种至裸鼠大脑尾状核,建立胶质瘤原位移植瘤模型,利用小鼠活体成像系统监测脑内肿瘤的生长情况,并通过石蜡切片,HE染色评价细胞在裸鼠脑内的病理特征及成瘤能力。结果成功构建稳定表达GFP荧光和luciferase荧光的U251胶质瘤细胞系及动物模型,慢病毒整合并未改变细胞的增殖、迁移及侵袭能力;模型生长周期适中,成瘤率高,瘤体在颅内生长稳定,HE切片符合人胶质瘤特征。结论双荧光标记的胶质瘤细胞相比于传统细胞更有利于胶质瘤动物模型的实验研究;U251-GFP-Luc胶质瘤细胞裸鼠模型,其肿瘤生长和病理特性与人胶质瘤相似,且可实时观察肿瘤生长,可作为胶质瘤实验研究的理想动物模型。Objective To establish a stable and real-time monitorable nude mouse model of orthotopic glioma xenograft. Methods U251 glioma cell line was infected by a leutiviral vector containing green fluorescent protein (GFP) and luciferase (Luc) gene. Ceils stably expressing fluorescence of GFP and Luc were sorted by flow cytometry. CCK-8 test and Transwell tumor invasion and migration assay were used to compare the biological features between the ceils stably expressing GFP-Luc fluorescence and cells without fluorescence. Then the ceils were implanted intracranially in the right caudate nucleus of athymic BaIb/c nude mice to establish the tumor model. The growth of intracerebral tumor was monitored over time by a bioluminescence imaging (BLI) system. Hematoxylin-eosin (HE) staining was used to evaluatethe histopathological features and tumorigenicity of the transplanted glioma cells in the brain of nude mice. Results U251 glioma cell line with stably expressing GFP-Luc fluorescence and the corresponding orthotopic xenograft model were successfully established. There was no statistically significant difference in the proliferation, invasion and migration abilities between the cells with stably expressing GFP-Luc fluorescence and the control cells. This model showed a high tumor formation rate and stable tumor growth, and takes a moderate time to establish this model. Conclusions Compared with the traditional glioma cells, GFP-Luc-transfected human glioma cells are more feasible for the studies of glioma in vivo. The tumor growth and pathological characteristics in this U251-GFP-Luc glioma model are similar to human glioma, and the growth of this tumor can be real-time monitored. It can be used as an ideal animal model for experimental studies of glioma.国家自然科学基金(编号:30970733)
An alys is and Measurement on Refractive Index Sensing of Few Mode Fiber Bragg Gratings
中文摘要:理论分析和模拟计算了少模光纤布拉格光栅基模及高阶模的耦合与传输特性,得到在相同外部折射率变化情况下,少模光纤基模与高阶模耦合对应的布拉格波长变化,比正、反向基模之间耦合对应的布拉格波长变化显著增大。实验上制作了少模光纤布拉格光栅,测量了基模之间以及基模与高阶模之间对应的布拉格波长随外部折射率、温度变化的情况,得到与理论分析相符的结果。而对于温度变化对折射率测量结果干扰的问题,提出了通过计算布拉格波长差来克服温度影响的方法。这些结果为采用布拉格光纤光栅测量外部折射率变化提供了一种新的途径。英文摘要:The coupling and propagation characteristics of fundamental modes and high-orde r modes in the few mode
fiber Bragg grating was numerically analyzed and simulated. It is indicated that the shifts of the Bragg wavelength
corresponding to the coupling between the fundamental mode and the backward high-order mode is obviously larger than the shift of the Bragg wavelength cor responding to the coupling between the forward and backward fundamental modes . The few mode fiber Bragg grating was fabricated , and the variations of Bragg wavelengths corresponding to
fundamental modes coupling and fundamental high-order modes coupling with external refractive index and temperature were measured. The experimental results agree with the theoretical analysis . Therefore by the means of Bragg wavelength difference calculation , the temperature induced fluctuation is overcome , which presents a new ray to measure the exte rnal ref ractive index change of fibe r Bragg gratings .基金项目: 国家自然科学基金(60177026) 、厦门大学985 项目和上海市重点学科建设项目( T0102) 资助课题
The dist ribution of mar ine colloids and their morphological characteristics
国家重点基础研究发展规划项目( G200078500) ; 国家杰出
青年科学基金项目( 49825162
基于水平集和最大稳定极值区域的颈椎椎体分割方法
颈椎椎体的分割在颈椎图像处理中起着关键的作用,是颈椎病灶确定和辅助诊断的重要基础.针对颈椎椎体边缘特征复杂的特点,提出一种基于水平集和最大稳定极值区域(maximally stable extremal regions,MSER)融合的颈椎椎体分割方法.首先采用基于图像密集度分布的图像分割方法对图像进行粗分割,自动提取颈椎区域;然后采用改进的水平集方法提取出颈椎椎体的前缘轮廓;根据颈椎椎体后缘的局部稳定特征,采用改进的MSER方法提取出椎体的后缘高亮区域,并结合椎体结构特征,采用最小二乘法拟合出椎体的后缘曲线;最后融合颈椎椎体前缘轮廓与后缘曲线,从而提取完整的颈椎椎体.实验结果表明,该方法能有效地分割和提取颈椎椎体,提取的后缘曲线接近专家手工提取的结果,可以为颈椎病的临床诊断提供更客观的诊断依据.国家自然科学基金(61373077);;福建省自然科学基金(2015J01587);;福建省科技厅资助高校项目(JK2010056);;福建省教育厅项目(JB10160
碳稳定同位素技术在植物水分胁迫研究中的应用
植物体的碳稳定同位素组成主要由植物本身的生物学特性决定, 但环境胁迫对其影响也十分明显。综述了碳稳定同位素
技术在研究植物水分利用效率、生物量高低及判断历史气候依据等研究领域的进展, 阐明了植物体的D13C 值对干旱、盐分及其
它环境因素的变化所引起的水分胁迫的响应, 并对碳稳定同位素对水分胁迫的响应机理进行了归纳和推断
协作征管:共建环保“税时代”
背景材料:1月1日起,《中华人民共和国环境保护税法》《中华人民共和国环境保护税法实施条例》同步施行。环保税的开征,意味着我国税收在生态环境方面的调控作用进一步强化,推动企业加速绿色转型
Effects of La~(3+) on ATPase Activities of Plasma Membrane Vesicles Isolated from Casuarina Equisetifolia Seedlings under Acid Rain Stress
The effects of La3 + on the growth and the ATPases activities of plasma membrane (PM) vesicles isolated from
Casuarina equisetifolia seedlings under artificial acid rain (pH 4. 5) stress were studied. The results show that the height ,
length of roots , fresh weight and PM H+2ATPase activites of Casuarina equisetifolia seedlings increase by the treatments of
soaking seeds in LaCl3 solutions with lower concentrations , and those can reach their peak values by treating with 200 mg
·L - 1 La3 + . However , in comparison with the CK, those are inhibited by the higher La3 + concentrations ; PM Ca2 +2AT2
Pase activity is inhibited with the treatments of La3 + . The results also reveal that the H+2ATPase activity and the growth
of cell enlarge have a remarkable positive correlation , and La3 + activating H+2ATPase can facilitate plant growth. La3 + al2
so can alleviate cytosolic acidification of plant under acid rain stress and indirectly maintain the stability of intracellular
environment . In order to resistant to acid rain and accelerate the growth of Casuarina equisetifolia , the suitable range of
La3 + concentrations to soak seeds for 8 h is 50~200 mg·L - 1
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