In spite of significant concerns about Hg contamination and its toxic impacts in the environment, limited studies have been carried out in Korea. The objectives of this study are to investigate the extent and degree of Hg contamination in soil, sediment, dust and sludge from various anthropogenic sources in Korea, and to understand the distribution patterns of Hg in the study areas. The anthropogenic sources of Hg contamination were divided into four major sources: (1) by-product from abandoned Au-Ag mines; (2) coal combustion; (3) cement production; and (4) industrial and domestic discharges. A calculation of enrichment factor and index of geoaccumulation for Hg in soils and sediments indicated that some samples from mining sites were enriched in Hg. In addition, Hg concentrations in marine sediments from industrial sites were above the Effects Range Median (ERM) criteria suggested by the National Oceanic and Atmospheric Administration of the United States (NOAA). Therefore, it can be concluded that samples from various sites were directly influenced by anthropogenic sources of Hg in the surface environment.

Effects of Ag content on microstructure, mechanical properties, and electrical conductivity in long time aged Cu-Ti-Ag alloys were investigated. In short time ageing condition, both electrical conductivity and mechanical properties were enhanced by Ag addition. On the other hand, in long time ageing condition, Ag addition showed a faster deterioration of mechanical properties than Ag free CuTi alloys.

The biological changes in recurrent laryngeal cancer following radiotherapy are not fully understood. The authors investigated differences in the expression of p53, proliferating cell nuclear antigen (PCNA) and bcl-2 in laryngeal cancer specimens before radiotherapy and in recurrent laryngeal cancer specimens following radiotherapy in the same patients. The authors investigated the expression of p53, PCNA and bcl-2 by immunohistochemical stain in 30 specimens from 15 patients with primary laryngeal cancer and recurrent laryngeal cancer after radiotherapy.

The expression of p53 protein was significantly different in laryngeal cancer before radiotherapy (4/15, 26.7 per cent) compared with recurrent laryngeal cancer after radiotherapy (8/15, 53.3 per cent) (p < 0.05). The PCNA index was also significantly different in laryngeal cancer specimens before radiotherapy (mean, 11.9 per cent) compared with recurrent laryngeal cancer after radiotherapy (mean, 18.0 per cent) (p < 0.05). However, there was no statistically significant alteration of bcl-2 expression in primary compared with recurrent laryngeal cancer. The expression of p53 and PCNA increased in recurrent laryngeal cancers after radiotherapy, compared with that in laryngeal cancers before radiotherapy. Recurrent laryngeal cancers arising following radiotherapy became biologically aggressive.

Telomerase maintains the length of telomeres in immortal cells and is also often associated with cell proliferation. Cholesteatoma epithelium is characterized by a dysregulation with hyperproliferative growth. The study evaluated the telomerase activity in cholesteatoma and normal retro-auricular skin to discover the relationship between telomerase expression and clinical findings. Twenty-two samples of cholesteatoma and 15 samples of retro-auricular skin were obtained from patients undergoing middle-ear surgery. The telomerase activity was detected by the telomerase repeat amplification protocol (TRAP) assay method. Seventeen of the 22 (77.3 per cent) cholesteatoma cases expressed telomerase activity, whereas none of the 15 retro-auricular normal skin (0 per cent) detected telomerase activity. There was no significant difference between telomerase expressions and clinical findings, including hearing level, duration of disease, and the degree of extension (p>0.05). The high expression of telomerase in cholesteatoma suggests that the activation of telomerase may be related to the proliferative nature of cholesteatoma.

Highly c-axis-oriented Bi3.25La0.75Ti3O12 (BLT) films with a homogeneous in-plane orientation were successfully grown on SiO2/Si(100) and Pt/Ti/SiO2/Si(100) substrates by a sol-coating route. The substitution of lanthanum ions for bismuth ions in the layered perovskite suppressed the formation of pyrochlore phase and enhanced the c-axis-oriented growth. The c-axis-oriented BLT film fabricated on a Pt/Ti/SiO2/Si(100) substrate showed fatigue-free characteristics with a large remanent polarization of 26–28 μC/cm2 and the coercive field of 50–75 kV/cm. These features significantly enhance the potential value of the BLT film for the applications to high-density ferroelectric random-access memories devices. In addition, the c-axis-oriented BLT film, with a homogeneous in-plane orientation on an amorphous surface, can be used as a suitable template material for applications to various electro-magneto-optic devices.