火灾工况下城市隧道自然通风模型实验

南京城东隧道采用自然通风方式,为判定其在火灾工况下能否满足安全性要求,开展了火灾工况下隧道自然通风模型实验,考察了最不利工况下烟气排除效果.从理论上探讨了模型与原型的相似规律,并以此为指导搭建模型实验台.结合实验现象和数据,分析了烟气温度、CO2浓度分布变化规律和烟气运动规律,与隧道原型实验进行了对比,验证了实验结果的可信性.并对火灾时逃生人员的安全性进行了分析,得到了烟气温度最高达77.2°C,烟气大部分时间维持在2 m以上高度的结论,此时逃生人员的安全能够得到保证.     

胃印戒细胞癌中CD44v6，Survivin与PTEN的表达及临床病理学意义

探讨黏附相关因子变异体CD44v6、凋亡抑制基因Survivin和抑癌基因FIEN在胃印戒细胞癌组织中的表达与其临床病理特征之间的关系,及三者的关系。表明应用免疫组织化学SP法,检测CD44v6、Survivin和FIEN蛋白在73例胃印戒细胞癌组织中的表达。结果胃印戒细胞癌中CD44v6、Survivin和PIEN蛋白的阳性表达率分别为78．1％（57／73）、63．0％（46／73）、34．2％（25／73）。CD44v6随胃印戒细胞癌浸润深度加深、淋巴结的转移逐渐上升（P〈0．05）;随浸润深度加深、淋巴结的转移、器官转移、临床分期增加Survivin蛋白的阳性表达率逐渐上升（P〈0．01）,而FTEN基因的阳性表达率逐渐降低（P〈0．05）。在胃印戒细胞癌组织中CD44v6与PFEN蛋白的表达呈负相关（相关系数r=-0．214,P〈0．05）,Survivin与PTEN的表达呈负相关（r=-0．404,P〈0．01）,CD44v6与Survivin的表达呈正相关（r=0．28,P〈0．01）。因此可知,CD44v6、Survivin和PIEN基因的异常表达与胃印戒细胞癌临床病理特征有关,PIEN和Survivin基因表达可以作为判断胃印戒细胞癌生物学行为的指标;CD44v6与Survivin的协同作用,以及两者与PTEN拮抗作用共同参与胃印细胞癌的发生发展过程。     

用玻尔原子模型轨道能量与光子能量比解精细结构常数

用玻尔原子模型轨道能量与光子能量比的方式,对精细结构常数值的求解作了论证;对以玻尔原子模型轨道速度V与光速c比的精细结构常数值求解,与玻尔原子模型轨道能量与光子能量比的同值性作了分析;并论证了由速度比定义的精细结构常数,是一般式玻尔原子模型轨道能量与光子能量比的特解。     

关于两两独立的随机变量序列和的强大数定律的简洁证明

本文讨论了两两独立的r.v.序列和的强大数定律,将文[1]中的结论进行了推广。与经典的强大数定律相比,本文的证明过程更简洁,不需要利用Kolmogrov不等式,而且结论更实用,只要求r.v.两两独立。     

HBME-1、Galectin-3和CD44v6在甲状腺滤泡癌与不典型腺瘤中的表达

 探讨间皮瘤相关抗体-1（HBME-1）、半乳糖凝集素-3（Galectin-3）及粘附分子CD44v6在甲状腺滤泡癌（Follicular Thyroid Carcinoma,FTC）与不典型腺瘤（Atypical Thyroid Adenoma,ATA）中的表达差异,寻找有助于二者临床病理诊断的肿瘤标记物及探索其部分发病机制,拟解决在甲状腺临床病理中对良、恶性难以确定的滤泡性肿瘤的准确判定及对其预后的预示作用。采用免疫组化SP三步法检测37例FTC及18例ATA中HBME-1、Galectin-3和CD44v6的表达,以10例嗜酸性腺瘤（OncocyticThyroid Adenoma,OTA）、8例普通滤泡性腺瘤（Follicular Thyroid Adenoma,FTA）、7例甲状腺乳头状癌（Papillary ThyroidCarcinoma,PTC）及5例尸检正常甲状腺组织作为对照。结果显示,HBME-1、Galectin-3及CD44v6在FTC中的阳性表达率分别为70.3%、64.9%和62.2%,在ATA中阳性表达率分别为66.7%、61.1%和61.1%,三者在FTC与ATA中的表达差异均无统计学意义（χ2分别为0.074、0.094、0.245,P值分别为0.786、0.759、0.620,P值均＞0.05）;在10例OTA中的表达均为100%;8例FTA中的表达分别为3/8例、6/8例及4/8例;7例PTC的表达分别为7/7例、6/7例及7/7例;5例正常尸检甲状腺组织均无表达。由此得出结论： HBME-1、Galectin-3和CD44v6对FTC与ATA的临床病理鉴别诊断无统计学意义,但提示三者可能在甲状腺滤泡癌与不典型腺瘤的发病机制及进展过程中起着某种共同作用。由于此3种标记物已被证实在诸多肿瘤的发生、发展过程中起着重要作用,故在实际甲状腺临床病理诊断中对表达此3种标记物的良、恶性难以确定的病例可能提示其恶性程度增高,尽管不足以诊断为癌,但仍应加强随访。有关FTC与ATA的临床病理诊断与鉴别诊断及二者的发病机制尚有待于进一步的探索和研究.     

具有乘法噪声的单模激光模型的系统消去程序

用Schner和Haken建立的系统消去法和系统绝热近似法对两种具有乘法噪声的单模激光模型进行研究,分别得出了其Ito形式和Stratonovich形式的序参量方程,并对随机序列z_t~(v)的统计性质进行了计算.最后,定性地分析了Ito形式和Stratonovich形式不等价的原因.     

The biotransformation of tritiated 3-dehydroecdysone by crayfish,Procambarus clarkii

The injection of 3-dehydroecdysone (3dhE, 5 /g), the major ecdysteroid secreted by the Y-organ of crayfishProcambarus clarkii, resulted in apolysis within about 5 days. The hormonal response at the molecular level was investigated by injection of the radio-labeled compound; within 3 h of injection of [³H]3dhE, most radio-isotope was found in the extracted epidermal tissues and identified as ecdysone, 20-hydroxyecdysone (20E), and their 3-hydroxy epimers. The biotransformation was undoubtedly performed in the peripheral area of the Y-organ. Cleavage of the polar conjugates, using an enzyme fromHelix pomatia, gave all of the above ecdysteroids including 3dhE. It was also found that the biosynthetic site of 3dhE was different from that of ecdysone at the subcellular level of the Y-organ.     

低速冲击下钢筋混凝土梁局部变形刚度

研究了低速冲击下钢筋混凝土梁的截面刚度,以及冲击体和结构间接触区域的柔度变化.将梁分成斜裂缝形成以前和斜裂缝形成以后两个阶段来研究.斜裂缝形成以前,梁被看成弹性均质体,接触区的柔度由受压和受拉条件下混凝土的柔度串联而成,根据柔度的定义推导得出该阶段接触区的刚度;斜裂缝形成以后接触区的刚度受高为χw弯—剪式固端梁构件、下部受拉钢筋、冲击体与下部钢筋之间的混凝土柱的制约,从而推导出该阶段的柔度.结合两个阶段接触区域的柔度公式,对低速下钢筋混凝土梁的接触刚度进行了举例计算和分析,表明斜裂缝形成以前的阶段可以忽略不计.     

Hydra vulgaris ω10-lipoxygenase is used in vivo to synthesize new α-linolenic acid metabolites

Previous studies conducted in cytosolic extracts of the freshwater hydrozoanHydra vulgaris led to the finding of an abundant 11(R)-lipoxygenase catalyzing the peroxidation of polyunsaturated fatty acid (PUFAs) on the tenth carbon atom from the aliphatic end (10 peroxidation). Here we describe experiments aimed at identifying the actual metabolites generated in vivo by such enzymic activity. Homogenates ofH. vulgaris polyps were analyzed by HPLC. This showed the presence of three major components chromatographically identical to three metabolites obtained when incubating the homogenates with exogenous -linolenic acid (-LA). The presence, in extracts of polyps prelabelled with [¹⁴C]--linolenic acid, of radioactive metabolites displaying the same chromatographic properties, substantiated the hypothesis that the natural products isolated in vivo are derived from -LA. Gas chromatographic analyses revealed that this was the most abundant PUFA in both free and phosphoglyceride-bound fatty acid pools. [¹H]-NMR analysis of the endogenous substances, carried out in comparison with products obtained from exogenously incubated -LA, indicated that their structures were those of 9-hydroxy-, 9-hydroperoxy- and 9-keto-octadeca-10E-12Z-15Z-trienoic acids (9--HOTrE,-HPOTrE and-KOTrE).Hydra homogenates transformed 9--HPOTrE partly into 9--HOTrE and partly into 9--KOTrE. Chiral phase HPLC conducted on 9--HOTrE established that this metabolite was composed mostly of theR anantiomer. These observations, and the finding that the presence of exogenous arachidonic acid in incubated homogenates significantly reduces the production of -LA metabolites, provide strong evidence that these compounds are produced by an enzymic activity identical to the previously-describedH. vulgaris (R)-10-lipoxygenase. Further experiments suggested that -LA, acting as the native substrate for this enzyme, is mainly esterified on the 2 position ofHydra phosphoglycerides, and that the production of the -LA metabolites described here for the first time from natural sources, can be potentially enhanced in vivo by stimuli activating phospholipase A₂.     

Differential expression and dosage compensation of theα-amylase gene inDrosphila miranda

Summary The-amylase gene ofDrosophila miranda is located on the X²-and on the neo-Y-chromosome, both developing sex chromosomes. Crosses between strains carrying different electrophoretically distinguishable alleles of the-amylase gene were performed. Females of the F₁ offspring showed the expected heterozygosity, while the males proved to be hemizygous for this locus. Only the gene on the X²-chromosome is expressed, whereas the corresponding gene on the neo-Y-chromosome is not. Estimates of the-amylase activity in crude homogenates of male and female flies suggest strongly that the-amylase gene is dosage compensated inD. miranda. In contrast to this situation, in all otherDrosophila species the-amylase allele is autosomal and hence not dosage compensated.Acknowledgments. We would like to thank Betty C. Moore, for the kind supply ofD. miranda strains. For the help and advice in the electrophoretic separation of the-amylase variants we are indebted to Dr W. Pinsker. This work was supported by a grant from the Fonds zur Förderung der wissenschaftlichen Forschung, P5413 (Austria).