Chromosomal localization of a unique gene by non-autoradiographic in situ hybridization

During the past few years, several methods have been developed for the detection of specific nucleic acid sequences by in situ hybridization using non-radioactive labels such as fluorochromes, cytochemically detectable enzymes and electron-dense markers. These methods are preferable to autoradiography in terms of speed of performance and topological resolution. Their limited sensitivity, however, has so far restricted their use to the detection of repeated sequences. Here we report single gene detection with a procedure using 2-acetylaminofluorene (AAF)-modified probes, immunoperoxidase cytochemistry and reflection-contrast microscopy. We confirmed the autoradiographic data on the localization of the human thyroglobulin (Tg) gene to the distal end of the long arm of chromosome 8. A mixture of cosmid cHT2-derived subclones of the 3' part of the Tg gene, 22.3 kilobase pairs (kbp) in total, was used as a hybridization probe. This procedure can be used to map other unique sequences, if genomic clones are available from which clones with an appropriate amount of inserts can be isolated.     

集成电路高精度高速度在线电阻检测

本文提出的具有粗、精测双回路的测试系统,可兼顾电阻在线检测过程中的高精度与高速度问题。该系统各器件间的信息交换满足IEEE-488标准。     

Karyotypes of seven species of bats from Thailand (Chiroptera,Mammalia)

Summary Karyotypes ofMyotis siligorensis, Myotis mystacinus, Pipistrellus pulveratus, Tylonycteris robustula, Miniopterus schreibersi fuliginosus, Hipposideros fulvus andAselliscus stoliczkanus from Thailand are investigated.Acknowledgment. The authors are very grateful to Dr N. Ratanawarabhan, Mrs S. Sittilert, P. Noonpakdee and S. Kuanchalern of Thailand Institute of Scientific and Technological Research for their valuable advice and assistance during our field survey in Thailand.     

计算机集成系统的概念与开发

讨论建立计算机集成系统的可能性与必要性。提出建模方法、结构化的开发步骤以及在开发过程中存在的各种问题。     

中性磷萃淋树脂吸附铼的性能和机理研究ⅢCL－P＿（350）－KReO＿4－HNO＿3体系

本文报道四甲基膦酸二甲庚酸萃淋树脂（ＣＬ－Ｐ＿（３５０）从硝酸溶液中吸附鳞的性能和机理研究。实验结果表明，吸附平衡服从Ｌａｎｇｍｕｉｒ经验等温式。测得吸附物分子中Ｐ（３５０）与Ｒｅ（Ⅶ）的摩尔比为２：１。Ｒｅ（Ⅶ）是以形式被树脂吸附，其吸附机理属于综合反应：并测定了吸附过程的热力学函数。     

加入WTO后山西省果业发展的思考

论述了加入WTO后山西省果业发展的明显优势及面临的严重挑战，提出了全面提高山西果业竞争力的具体措施。     

Acquired immunity and epidemiology of Schistosoma haematobium

Human immune responses to schistosome infection have been characterized in detail. But there has been controversy over the relative importance of ecological factors (variation in exposure to infection) and immunological factors (acquired immunity) in determining the relationships between levels of infection and age typically found in areas where infection is endemic. Independent effects of exposure and age on the rates of reinfection with Schistosoma haematobium after chemotherapy have been demonstrated in the Gambia and Zimbabwe. This age effect could be the result of acquired immunity to infection. Indeed, allowing for variation in exposure and age, low rates of reinfection in the Gambia are correlated with high amounts of specific IgE antibodies--human IgE can kill S. mansoni schistosomulae in vitro. Further, animals can acquire immunologically mediated resistance to S. mansoni infection, although nonimmunological factors could also be involved. Acquisition of this immunity seems to be related to the cumulative effects of repeated infection and provides only partial protection. These characteristics are consistent with immuno-epidemiological data for both S. mansoni and S. haematobium infections of humans. We have now analysed age-prevalence data for human infection with S. haematobium, and find patterns of variation that are indeed consistent with the epidemiological effects of acquired immunity predicted by mathematical models.     

中碳钢退火孪晶的形态及形成机制

利用光学显微镜对中碳钢退火孪晶的形态及形成机制进行了研究。退火孪晶是中碳钢过热组织的特征之一。其形态分穿晶型和中止型，分别按横向、纵向机制形核长大。退火孪晶有利于晶粒细化     

GOSCA－CFAR检测器在干扰边缘中的性能分析

本文研究ＧＯＳＣＡ—ＣＦＡＲ检测器￣［１，２］干扰边缘中的性能。文中推导出了它的干扰边缘环境中虚警概率的解析表达式，分析了它抗边缘干扰的性能，并且与ＯＳ、ＣＡ、ＧＯ和ＳＯ等检测器进行了比较。结果表明，ＧＯＳＣＡ的抗干扰边缘性能比ＣＡ和Ｋ＿（ｏｓ）＝（ｋ＋ｌ）＿（ＧＯＳＣＡ）和ＯＳ相近，比抗边缘干扰性能较好的ＧＯ要差。     

Mutation of the matrix metalloproteinase 2 gene (MMP2) causes a multicentric osteolysis and arthritis syndrome.

The inherited osteolyses or 'vanishing bone' syndromes are a group of rare disorders of unknown etiology characterized by destruction and resorption of affected bones. The multicentric osteolyses are notable for interphalangeal joint erosions that mimic severe juvenile rheumatoid arthritis (OMIMs 166300, 259600, 259610 and 277950). We recently described an autosomal recessive form of multicentric osteolysis with carpal and tarsal resorption, crippling arthritic changes, marked osteoporosis, palmar and plantar subcutaneous nodules and distinctive facies in a number of consanguineous Saudi Arabian families. We localized the disease gene to 16q12-21 by using members of these families for a genome-wide search for homozygous-by-descent microsatellite markers. Haplotype analysis narrowed the critical region to a 1.2-cM region that spans the gene encoding MMP-2 (gelatinase A, collagenase type IV; (ref. 3). We detected no MMP2 enzymatic activity in the serum or fibroblasts of affected family members. We identified two family-specific homoallelic MMP2 mutations: R101H and Y244X. The nonsense mutation effects a deletion of the substrate-binding and catalytic sites and the fibronectin type II-like and hemopexin/TIMP2 binding domains. Based on molecular modeling, the missense mutation disrupts hydrogen bond formation within the highly conserved prodomain adjacent to the catalytic zinc ion.