Induction of superoxide dismutase isozymes by tumor necrosis factor-alpha and lipopolysaccharide in cultured normal and hyperplastic gingival fibroblasts

We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ.     

分子结构对增塑聚氯乙烯性能的影响

研究了聚合度、分子量分布和支化结构对增塑聚氯乙烯加工流变性能和物理力学性能的影响。结果表明，增塑ＰＶＣ的加工流变性能随聚合度的增加而恶化；拓宽分子量分布和引入支化结构均有利于加工流变性能的提高；增塑ＰＶＣ的拉伸强度随聚合度的增加而提高，而压缩永久变形却随之减小；分子量分布对物理力学性能的影响不大；支化ＰＶＣ的拉伸强度略有下降。     

ATM局域网仿真技术

本文介绍了ＡＴＭ局域网仿真技术并从ＡＴＭ仿真局网的组成、工作原理等方面介绍了这一技术的主要特点。     

Deformation analysis of skew ruled surface shells by moiré interference

The use of thin film grids coated on surfaces is described in relation to the determination of deformations in doubly curved shells. The technique is called the coating film moiré interference method and employs a laser holographic approach.     

PTC－BaTiO_3射频溅射用靶材的制备

研究了用于射频溅射ＰＴＣ－ＢａＴｉＯ_３薄膜的厚大靶材制备工艺，所制成的靶材的室温电阻率为８００Ω·ｃｍ，ＰＴＣ效应＞１０５，平均粒径为１～３μｍ，讨论了配方中ＴｉＯ_２品种的选择、施受主添加剂的搭配与掺量以及烧成中的升降温速率对于ＰＴＣ效应的影响     

钙—铈氟碳酸盐矿物中BmSn型新多型的发现及其微结构研究

利用Philips CM-12分析型透射电镜对四川昌北大型稀土矿床中钙铈氟碳酸盐矿物进行了研究。除证实氟碳钙铈矿(BS)存在3R和6R2种多型外,首次发现和研究了氟碳钙铈矿(BS)存在4H、12H、18R、24R、30R和36R6种新多型;伦琴矿(BS_2)1种6R新多型和B_2S新规则混层矿物2H、12R和24R3种中新多型。电子衍射和晶格象分析表明:该类矿物中众多新多型的产生,主要是由于矿物结构单元层沿(?)轴有序堆垛和[CO_3]的定向周期性变化所致。     

一种新型硫酸亚铁单液法调剖剂

本文提出用尿素作为ｐⅡ调节剂，加快硫酸亚铁单液法调剖剂中亚铁离子在地层温度下的沉淀，增大沉淀率，提高封堵效能。岩芯流动试验结果表明，１５％ＦｅＳＯ４．７ＩＩ ２Ｏ／５％尿素调剖剂体系的封堵能力比不含尿素的体系增大近一倍。     

Compact equivalent circuit model of two‐layer spiral inductors

A compact lumped‐element equivalent circuit model of two‐layer integrated spiral inductors on silicon substrates is developed in this article. Based on this proposed model, excellent agreements are achieved between the measured and simulated S‐parameters for different inductors. Also, both self‐ and mutual inductances of two‐layer inductors are accurately extracted, and their overall performances are understood clearly. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 148–153, 2003.