血管内皮生长因子和白细胞介素-12在急性白血病中的表达及临床意义     

高丽君  夏薇  杜冰洋 《中国科学院研究生院学报》2007,24(3):368-371

目的 通过检测急性白血病（AL）患者静脉血清中血管内皮生长因子（VEGF）和 白细胞介素12（IL-12）的含量，探讨VEGF和IL-12在急性白血病中的含量及临床意义。方法 应用定量酶联免疫吸附实验测定10例初诊未治、10例缓解期、5例复发患者和9例正常对照血清中VEGF和IL-12的含量。结果 初诊未治组的VEGF含量（521.06±163.85pg/ml）明显高于缓解组（307.62±55.40pg/ml）及对照组（262.01±141.66pg/ml）（p均<0.05）。对照组的IL-12水平（58.96±38.11pg/ml）与初诊复发组（初诊未治组与复发组的合称32.51±14.58pg/ml）、缓解组（71.67±119.09pg/ml）之间均有显著性差异（p均<0.05）。正常对照组VEGF的含量与IL-12之间存在负相关性。结论 VEGF和IL-12与AL的病情变化有一定的关系。  相似文献   

两种诱变剂对蚕豆根尖细胞遗传毒理学研究     

张胜 《商丘职业技术学院学报》2005,4(5):59-60

以蚕豆根尖为材料，用微核实验和染色体畸变试验方法，研究不同浓度的8-羟基喹啉与对苯二酚对蚕豆根尖细胞的有丝分裂指数、微核率和染色体畸变率的影响．结果表明：不同浓度的8-羟基喹啉与对苯二酚使蚕豆根尖细胞有丝分裂指数明显增加，诱发较高频率的微核，在一定浓度范围内，其微核率随处理浓度的升高而升高，但随着诱变剂浓度的升高而呈下降趋势．两种诱变剂还能诱导染色体产生多种类型的畸变，染色体畸变率随着处理浓度的增加而升高，随着浓度的进一步增加却呈现下降趋势，但均明显高于对照组．  相似文献   

过氧乙酸的制备方法与其稳定性的实验研究     

马春玉  杜新玲 《新乡师范高等专科学校学报》2005,19(2):42-43

为了分析、研究过氧乙酸生产中过氧化氢浓度、冰醋酸用量与不同稳定剂含量对产品稳定性的影响,对不同生产配方和加入稳定剂后的过氧乙酸产品在自然存放条件下的贮存稳定性进行了实验测定。结果显示,当过氧化氢与冰醋酸的配制比例为1:2时,过氧化氢浓度越高,过氧乙酸的产率越高;过氧乙酸浓度越高,贮存稳定性越差;1g.L-1的8-羟基喹啉或0.1%磷酸稳定剂可有效提高过氧乙酸的稳定性。  相似文献   

论文化对翻译的操控现象   总被引：1，自引：0，他引：1  

侯晶晶 《山西师大学报(社会科学版)》2001,15(1):113-118

本文借鉴西方操控学派的研究视角,结合文化学、心理学、社会学的理论成果,探讨文化对于翻译的多层面操控的原因及表现.其中,宏观文化因素包括文化交流的客观需要、文化的性质和水平、民族的文化心理结构和文化的稳定性,微观文化因素包括道德、宗教和学术传统及其发展水平.在目前的社会历史条件下,增强操控的积极作用之根本方法是在坚持主旋律的前提下倡导文化及翻译的多样性.  相似文献   

基于FPGA技术的8B/10B信道编码设计     

郑红党  孙彦景  李松  刘辉 《实验技术与管理》2021,(3):40-44

该文在分析8B/10B编码原理的基础上,设计了改进型8B/10B编码方案。该编码在完成高速数据信道编码功能的同时,可另外提供一路实时低速信道。基于FPGA技术采用查表法实现了改进型编解码电路,通过仿真验证了该编码方案的有效性,并在Spartan6系列FPGA中进行了综合测试。结果表明,此编解码方法占用的FPGA逻辑资源少,编解码速度可达到上百MB/s。  相似文献   

Multisim8在数字电路教学中的应用     

Liu rong 《广西大学梧州分校学报》2007,(6)

在数字电路教学中,恰当地运用Multiim8仿真软件进行实时仿真,将理论与实验相结合,可以克服传统理论教学中的不足,提高数字电路课程的教学质量。  相似文献   

Teachers’ perceptions of assessments of their mathematical knowledge in a professional development course     

Michelle T. Chamberlin  Jeff D. Farmer  Jodie D. Novak 《Journal of Mathematics Teacher Education》2008,11(6):435-457

The purpose of the project reported in this article was to evaluate how assessing teachers’ mathematical knowledge within a professional development course impacted from the teachers’ perspective their learning and their experience with the course. The professional development course consisted of a 2-week summer institute and the content focus was geometry. We had decided to assess the mathematical learning of the teachers during this professional development course for various accountability reasons, but were concerned about possible negative by-products of this decision on the teachers and their participation. Thus, we worked to design assessment in ways that we hoped would minimize negative impacts and maintain a supportive learning environment. In addition, we undertook this evaluation to examine the impacts of the assessment, which included homework, quizzes, various projects, and an examination for program evaluation. Seventeen grade 5–9 teachers enrolled in the course participated in the study by completing written reflections and by describing their experiences in interviews. We learned that while our original intent was “to do no harm,” the teachers reported that their learning was enhanced by the assessment. The article concludes by describing the various properties of the assessments that the teachers identified as contributing to their learning of the geometry content, many of which align with current recommendations for assessing and evaluating grade K-16 mathematics students.

Michelle T. ChamberlinEmail:

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气动机械手控制实验系统设计     

《实验室研究与探索》2017,(11):77-81

利用TMS320VC5509A和EP2C8Q208设计实现了一个气动机械手实验控制系统,通过DSP C和FPGA Verilog HDL语言编程取代了体积庞大的PLC控制系统,实现了20路电磁换向阀控制。16路10 bit DAC精确控制比例阀电压从而控制气动机械手指的动作力度,利用8路10 bit ADC采集指端触感压力传感器压力信号并且完成波形显示,提供机械手指的握力反馈信息,提高了机械手的控制精度和控制速度。  相似文献   

Fractions as the Coordination of Multiplicatively Related Quantities: A Cross-Sectional Study of Children's Thinking     

Susan B. Empson  Debra Junk  Higinio Dominguez  Erin Turner 《Educational Studies in Mathematics》2006,63(1):1-28

Although equal sharing problems appear to support the development of fractions as multiplicative structures, very little work has examined how children's informal solutions reflect this possibility. The primary goal of this study was to analyze children's coordination of two quantities (number of people sharing and number of things being shared) in their solutions to equal sharing problems and to see to what extent this coordination was multiplicative. A secondary goal was to document children's solutions for equal sharing problems in which the quantities had a common factor (other than 1). Data consisted of problem-solving interviews with students in 1st, 3rd, 4th, and 5th grades (n=112). We found two major categories of strategies: (a) Parts Quantities strategies and (b) Ratio Quantities strategies. Parts quantities involved children's partitions of continuous units expressed in terms of the number of pieces that would be created. Ratio quantities involved children's creation of associated sets of discrete quantities. Within these strategies, children drew upon a range of relationships among fractions, ratio, multiplication, and division to mentally or physically manipulate quantities of sharers and things to produce exhaustive and equal partitions of the items. Additionally, we observed that problems that included number combinations with common factors elicited a wider range of whole-number knowledge and operations in children's strategies and therefore appeared to support richer interconnections than problems with relatively prime or more basic number combinations.  相似文献   

3Cr2W8V模具钢球化退火工艺研究     

朱杰武 《陕西理工学院学报(社会科学版)》1997,(3)

分析模具凹模坯料用冷冲压制造型腔时开裂的原因，进行了几种3Cr2W8V模具钢球热处理软化工艺试验，观察了组织，测定了力学性能，获得实际生产中可行的3Cr2W8V模具钢球化退火工艺．  相似文献