Expression of the mutant gene for L-gulono-γ-lactone oxidase in scurvy-prone rats

A mutant strain of Wistar rats with L-gulono-TQ357738740104T/xxlarge947.gif" alt="gamma" align="MIDDLE" border="0">-lactone oxidase deficiency has recently been established. To investigate this deficiency by DNA and RNA blot hybridization analyses, a fragment of a previously cloned cDNA encoding rat L-gulono-TQ357738740104T/xxlarge947.gif" alt="gamma" align="MIDDLE" border="0">-lactone oxidase was used as a probe. When genomic DNA of the mutant rat was digested with several restriction enzymes, the probe hybridized to fragments of the same sizes as those produced from DNA of normal rats. Poly(A)⁺RNA from the liver of the mutant rat was found to contain an L-gulono-TQ357738740104T/xxlarge947.gif" alt="gamma" align="MIDDLE" border="0">-lactone oxidase-specific mRNA of a normal size at a comparable level to that of normal rats. An in vitro translation experiment revealed that the mRNA programmed the synthesis of an enzyme protein which had the same molecular weight as that of the translational product of the normal mRNA, although the amount synthesized was markedly reduced as compared with that synthesized with the normal mRNA. In accordance with this observation, a very low but definite degree of L-gulono-TQ357738740104T/xxlarge947.gif" alt="gamma" align="MIDDLE" border="0">-lactone oxidase activity was detected in the microsomes of the mutant rat by a newly developed, highly sensitive method.Acknowledgments. The authors thank Dr Susumu Makino, Shionogi Research Laboratories, Shionogi & Co., Ltd, Japan, for his kind donation of normal (ODS- +/+) and ODS (ODS-od/od) rats. This work was supported in part by Grant-in-Aid (59570103) for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

微波复数介电常数虚部ε″测量方法的研究

通过对现有介电常数实验方法的改进,并结合单片机对实验进行自动控制及数据的采集、处理、解决了反射式速调管微波源输出功率、频率不稳及现有实验测量仪器分辨率低等因素对测量微波复数介电常数虚部ε″的影响,提高了ε″的测量精度。     

关于计量调整型抽样检查方法国家标准的设计

计量抽样工作组于1983年在我国成立,它的任务是制订计量调整型抽样检查方法的国家标准。工作组认真研究了国际标准ISO3951—81,并用计算机验算和通过生产验证。在此基础上制订出国家标准草案“不合格品率的计量抽样检查程序及图表(适用于连续批的检查)”。本文介绍工作组在制订国家标准过程中的一些研究成果。     

全微机化DTC变频调速系统

异步电动机直接力矩控制（DTC）是一种新的高性能交流调速系统，本文介绍了用8098单片机实现的全微机化DTC控制系统，提出了一种简单、实用、高精度的电动机转速数字检测方法，在VMOS变频器上对系统进行了实验研究，结果表明该系统不仅结构简单，性能也不亚于矢量控制的变频调速系统。     

上海四膜虫酚溶性染色质非组蛋白的研究

收集对数生长期的上海四膜虫，分离细胞核，制备染色质并以酚抽提制得酚溶性染以质非组蛋白，经ＳＤＳ－ＰＡＧＥ测得四膜虫酚溶性染色非组蛋白有六条明显的蛋白带，其表观量为８８ＫＤ，７９ＫＤ，７０ＫＤ，５２ＫＤ，３８ＫＤ，２４ＫＤ，与鼠肝酚溶性染色质非组蛋白具有明显的５条的分子量有显著的差异。     

Piezoelectric immunoassay of thyroidal triiodothyronine

A re-utilizable piezoelectric crystal (PC) immunosensor for thyroidal triiodothyronine (T3) has been developed. The crystal was coated with protein A and then reacted with T3 antibody. T3 could be detected in the range of 0.5×10⁻⁶ g/L to 10.0×10⁻⁶g/L by the, system. Crystal was regenerated by saturating with T3 and subsequent binding of a new anti-T3 antibody layer. The T3 assay could be repeated up to 5 times using each crystal. Supported by the National Natural Science Foundation of China Zha Hongying: born May, 1969, Ph. D.     

Effects of diapause and host species on some morphometric characters inTrichogramma (Hym.: Trichogrammatidae)

Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.     

The development and function of regulatory T cells

Regulatory T cells (Tregs) are a critical subset of T cells that mediate peripheral tolerance. There are two types of Tregs: natural Tregs, which develop in the thymus, and induced Tregs, which are derived from naive CD4⁺ T cells in the periphery. Tregs utilize a variety of mechanisms to suppress the immune response. While Tregs are critical for the peripheral maintenance of potential autoreactive T cells, they can also be detrimental by preventing effective anti-tumor responses and sterilizing immunity against pathogens. In this review, we will discuss the development of natural and induced Tregs as well as the role of Tregs in a variety of disease settings and the mechanisms they utilize for suppression. C. J. Workman, A. L. Szymczak-Workman, L. W. Collison, and M. R. Pillai contributed equally.     

卟啉铊及其氰基配合物的205Tl NMR的溶液表征

在有机溶剂中 ,合成制备了新的单核卟啉铊和卟啉铊氰基配合物 ([(tpp) Tl(O2 CCF3) ]和 [(tpp) Tl(CN) ])。通过使用 1 3C富集的 1 3CN配体 2 0 5Tl核磁共振的研究 ,两个配合物的组成都得以清楚的表征 ,表明 2 0 5Tl核磁共振谱是确定溶液中铊配合物组成的一种有效方法     

极小T3LF拓扑空间

对任意完全分配格Ｌ和非空集Ｘ,本文证明了Ｌ＾Ｘ上极小Ｔ３ＬＦ余拓扑的存在性以及这种余拓扑的特征定理,并给出了构造Ｌ＾Ｘ上比给定的非极小Ｔ３ＬＦ余拓扑δ严格弱的Ｔ３ＬＦ余拓扑的一种方法。