Enhancive effect of N,N′-dinitrosopiperazine on inducing precancerous lesion on nasal and/or nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT mice

Objective  To investigate the enhancive effect of N,N′-dinitrosopiperazine (DNP) on induced carcinogenesis in nasal and/or nasopharyngeal epithelia among TgN(p53mt-LMP1)/HT transgenic mice to examine the underlying mechanism for the development of nasopharyngeal carcinoma (NPC). Methods  TgN(p53mt-LMP1)/HT transgenic mice and the same strain of C₅₇BL/6J wild-type mice both at the age of 5 months were randomly divided into 2 groups in parallel, respectively, i.e., TgN(p53mt-LMP1)/HT cancerous lesion-inducing group (TI), TgN(p53mt-LMP1)/HT control group (TC), C₅₇BL/6J cancerous lesion-inducing group (CI), and C₅₇BL/6J control group (CC). TI and CI mice were treated only with DNP for 16 weeks, twice each week, while TC and CC mice were given the same volume of saline as controls. At the end of treatment, animals were sacrificed to collect epithelial tissue samples from nasal cavity and nasopharynx for pathohistological evaluation by haematoxylin and eosin (HE) staining and for determination on the expression of TRAF2, c-Jun, and p16 by immunohistochemistry. Results  Atypical hyperplasia was more significant in the samples of TI than in those of TC, CI, and CC, with the rates of lesions being 90%, 10%, 0, and 0 (P<0.01) respectively, though DNP was used alone in a much shortened inducing period at less dosage and without the use of carcinogenic promoter 12-O-tetradecanoylphorbol-13-acetate as usual. The expressions of tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2) and c-Jun in these samples were significantly up-regulated in TI (P<0.01), while the expression of p16 was significantly lower in TI than in the other groups (P<0.01). Conclusion  TgN(p53mt-LMP1)/HT mice hold inherited constitutional defect in immune surveillance function, which can be aggravated by environmental carcinogens, such as DNP used even though in a much less strength. The enhanced carcinogenesis-inducing effect of DNP on TgN(p53mt-LMP1)/HT mice should be closely associated with abnormal signaling of activator protein-1 (AP-1) pathway, especially up-regulated expressions of TRAF2 and c-Jun, and down-regulated expression of p16. Project supported by the National Natural Science Foundation of China (Nos. 30672738, 30572455 and 30572408), Hunan Provincial Natural Science Foundation for Distinguished Young Scholars (No. 03JJY1006) and for General Projects (Nos. 05JJ40029 and 07JJ6038), the Research Foundation of Hunan Provincial Scientific and Technological Department for International Cooperative Academic Projects (No. 06WK3016), and the Research Foundation of Hunan Provincial Education Department for Outstanding Young Scholars (No. 06B070), China     

水下无人航行器回收技术研究

本文阐述了水下UUV对接回收的几种方式,以及这些对接回收方式的优缺点。分析了影响水下UUV对接回收技术的力学、控制以及导航等关键技术难题和相应的解决思路,探讨了水下UUV对接回收技术的发展趋势。     

基于STM32的远程升级系统的设计

本文介绍了一种基于STM32芯片的远程升级系统的设计方案。简述了从数据下载线、客户端、服务器到数据库MYSQL设计的全部过程,并提供了客户端、服务器的通信细节分析,提供了升级操作的可靠性和便利性。     

n维Lorentz变换

以Clifford代数为工具，讨论n维Minkowski空间的性质，得到n维Minkowski空间的Lorentz变换。     

N80钢在中性介质中垢下腐蚀机理的研究

碳钢管线在水的集输过程中常常发生了局部腐蚀,在NaHCO3-NaCl为中性介质的溶液里,研究侵蚀性阴离子对N80钢垢下腐蚀的机理以及腐蚀产物对电极电化学行为的影响。     

The developmental consequence of different patterns of maltreatment

From a longitudinal study of 267 high risk families, four different patterns of maltreatment were identified. The mothers have been tested, interviewed and observed in a number of situations starting during the last trimester of pregnancy and continuing at regularly scheduled intervals through the preschool period. The four maltreatment groups were: physical abuse; hostile/verbally abusive; psychologically unavailable; and neglecting. A control group of mothers who provided adequate care was selected from the remaining high risk sample. In an earlier follow-up, among the maltreated children a disproportionately large number of infants were found to be anxiously attached to their mothers at 12 and 18 months, and their performance in a problem-solving situation at age two was poor. In the current follow-up, the children were videotaped at 42 months in a "barrier box" and teaching situation, and at 56 months they were observed in a preschool situation. The physically abused children were distractible, lacked persistence, ego control and enthusiasm, and experienced considerable negative emotion. The children whose mothers were psychologically unavailable showed marked increases in maladaptive patterns of functioning from infancy through preschool. As expected, they were avoidant of their mother, angry, noncompliant, and they were highly dependent. The neglected children had the most difficulty pulling themselves together to deal with various tasks. They lacked self-esteem and agency necessary to cope with their environment.     

女娲神话的文化蕴涵

女娲补天神话既反映了远古居民对中华大地地理形势的认识及母系氏族社会中女性的崇高地位,也反映了中国最早的石图腾崇拜,并且对中国人“补”的思维方式及拼搏奋斗精神也都产生了深远影响。女娲造人神话展示了原始时代人们生育观念的三次演变,即由女神化育生人到抟黄土做人再到男女共同生人的过程。女娲死后又成为最早的高裸之神（俗称送子娘娘）,一直影响着中国人的婚姻生活。     

试论"V+N"式合成词中V的语义呈现特征

V N式合成词中,V的语义呈现决定于词素N,当N符合V的指代义的两个预设要求时,V就呈现指代义,整个词是动宾结构;当N不符合V的指代义的两个预设,反而意义上是V从属于N,那么,V就呈现指称义,整个词是偏正结构。     

N2分压对（Ti，A1）N涂层成分、结构及力学性能的影响水

采用电弧离子镀工艺,调节N2分压制备了系列（Ti,A1）N硬质涂层,研究了不同N2分压对涂层表面形貌、相结构、成分及力争性能的影响．结果表明,当氮气分压较低时,涂层金属相含量较高,涂层硬度和残余应力较低,膜／基结合力较高,涂层耐磨性较差;当氮气分压较高时,涂层氮化物相含量较高,涂层硬度和残余应力较高,膜／基结合力偏低,涂层耐磨性很强．     

一类食饵种群具有常数存放率的n+2次kolmogorov系统的极限环

讨论一类食饵种群具有常数存放率的n+2次kolmogorov系统:x′=x(a0+a1x-a2x2-a3yn-a4xyn)+F,y′=y(x2-1),得到系统不存在极限环和存在唯一极限环充分条件,并推广了前人的部分结果。