Fabrication of nano-scale Cu bond pads with seal design in 3D integration applications.

A method to fabricate nano-scale Cu bond pads for improving bonding quality in 3D integration applications is reported. The effect of Cu bonding quality on inter-level via structural reliability for 3D integration applications is investigated. We developed a Cu nano-scale-height bond pad structure and fabrication process for improved bonding quality by recessing oxides using a combination of SiO2 CMP process and dilute HF wet etching. In addition, in order to achieve improved wafer-level bonding, we introduced a seal design concept that prevents corrosion and provides extra mechanical support. Demonstrations of these concepts and processes provide the feasibility of reliable nano-scale 3D integration applications.

Sargachromenol, a novel nerve growth factor-potentiating substance isolated from Sargassum macrocarpum, promotes neurite outgrowth and survival via distinct signaling pathways in PC12D cells.

We previously found that the methanol extract of a marine brown alga, Sargassum macrocarpum showed marked nerve growth factor (NGF)-dependent neurite outgrowth promoting activity to PC12D cells. The active substance purified was elucidated to be sargachromenol. The median effective dose (ED50) was 9 microM against PC12D cells in the presence of 10 ng/ml NGF, although it showed no neurotrophic effect on its own. Pretreatment of cells with protein kinase A (PKA) inhibitor or U0126 substantially suppressed the sargachromenol-enhanced neurite outgrowth from PC12D cells, suggesting that the activation of cyclic AMP-mediated protein kinase and mitogen-activated protein (MAP) kinase 1/2 was apparently required for the action of sargachromenol. On the other hand, sargachromenol significantly promoted the survival of neuronal PC12D cells at 0-50 ng/ml NGF in serum-free medium. Neither PKA inhibitor nor U0126 could inhibit the survival supporting effect of sargachromenol, whereas wortmannin significantly blocked the sargachromenol-induced survival supporting effect on neuronal PC12D cells, suggesting that sargachromenol rescued neuronal PC12D cells by activating phosphatidylinositol-3 kinase. These results demonstrate that sargachromenol promotes neuronal differentiation of PC12D cells and supports the survival of neuronal PC12D cells via two distinct signaling pathways.

Youth risk behaviour in a Chinese population: a territory-wide youth risk behavioural surveillance in Hong Kong.

This cross-sectional study investigated the prevalence rates of different categories of youth risk behaviour by age, sex and parental education. The study population consisted of 26,111 Hong Kong students, aged 10-19 years, recruited from 48 primary (primary grades 4-6) and secondary schools (secondary grades 1-7). Less than one-third of subjects participated in vigorous exercise regularly, about one-third consumed an unhealthy diet frequently, 18% had tried smoking, and 14.5% had seriously considered attempting suicide. Although only 3.4% of students reported experience of sexual intercourse, less than half used a contraceptive device. Older students had higher prevalence rates of health-compromising behaviours than younger students. Female students were more likely to report suicide-related behaviour, attempting weight loss, and non-participation in vigorous physical activities. Students with parents of a lower educational background were more likely to report rarely or never wearing seat belts and bicycle helmets, suicide-related behaviour, smoking, sexual intercourse before 13 years of age, and attempting weight loss. The availability of data on youth health risk behaviours would enable health educators, public health practitioners and clinicians to plan appropriate screening and counselling for risk behaviours in early adolescents.

Acrylamide in Asian foods in Hong Kong.

About 400 food samples, mainly Asian foods available in Hong Kong, were tested for acrylamide by an LC-MS/MS method using [1, 2, 3-(13)C(3)]-acrylamide as surrogate. The acrylamide levels in the more commonly consumed food items in the food groups such as rice and rice products, noodles, bakery and batter-based products, were generally less than 60 microg kg(-1). Higher levels were found in the food groups such as biscuit-related products and crisps. The highest levels were detected in potato crisps (1500-1700 microg kg(-1)). Lower levels were found in rye flour-based crisps (440 microg kg(-1)), followed by corn-based (65 to 230 microg kg(-1)) and wheat flour-based crisps (61-200 microg kg(-1)), and then rice flour-based crisps (15-42 microg kg(-1)). The acrylamide formation during deep frying of a wheat flour-based product, Chinese fried fritter, was studied. Deep-frying at 170 degrees C resulted in gentle but steady rise in acrylamide content. A steep rise for frying at 210 degrees C was recorded. The moisture content of the product decreased with frying time, but the fat content increased. It is proposed that the reaction for the formation of acrylamide was initiated on the surface and then penetrated into the interior of the food matrix by heat transfer via radiation/conduction and diffusion of hot oil.

A YRBS survey of youth risk behaviors at alternative high schools and mainstream high schools in Hong Kong.

In Hong Kong, prevocational schools serve as an alternative to mainstream schools to provide education with more emphasis on practical and technical subjects. In this paper, health-risk behaviors of prevocational school (PVS) students were identified, and comparisons of health-risk behaviors with or without adjusting the demographic factors from prevocational schools and mainstream schools were made. The PVS students were at higher risk for most categories of health-risk behaviors such as unintentional and intentional injuries, smoking, alcohol drinking, glue sniffing, inadequate physical activity, insufficient consumption of fresh fruits and vegetables, and early sexual activity with multiple partners. Female students of PVS reported higher prevalence of emotional problems and substance abuse. Findings suggest that the school environment is an influential factor on the lifestyle behavior of students. Comprehensive health education and intervention programs are needed for youth in Hong Kong prevocational schools.

Older school children are not necessarily healthier: analysis of medical consultation pattern of school children from a territory-wide School Health Surveillance.

It is important to maintain the health of our school children as health is a major factor affecting learning. In developed countries, we assume that school children, especially in higher grades, are healthy because they are relatively free of diseases. However, many of the health problems encountered by school children are not reported in routine health data as they seek help in primary care or by self-medication. In this paper, the medical consultation pattern of school children in Hong Kong was analyzed. It was revealed that school children had a high rate of consultation and self-medication, and the health status of older school children is not better. They were not offered adequate preventive advice. The piecemeal approach to focus on curative medicine will only lead to a high rate of episodic consultation and self-medication without empowering the young people with the skills of self-care and self-help, and positive health behavior. The concept of a health-promoting school with emphasis on more extra-curricular health promotion activities, improved communication between health and education sectors, active involvement by pupils and parents, and changing policies and practices would help to make the co-ordinated school health program a greater success.

Biodegradation capacity of tributyltin by two Chlorella species.

Two microalgal species, Chlorella vulgaris and Chlorella sp., which showed high tributyltin (TBT) tolerant ability were investigated for their capabilities in degrading TBT at sublethal concentration. The distribution of TBT and its degraded products dibutyltin (DBT) and monobutyltin (MBT) in the incubation medium, extracellular surface and intracellular fraction were monitored during an exposure period of 14 days. Results showed that biosorption of TBT by the algal cell wall was the major mechanism in reducing 40% of the initial TBT from the medium in the first 2 days. The half-life of TBT incubated with C. vulgaris was 60 h while that of Chlorella sp. was 80 h. The occurrence of DBT at Day 1 in the culture medium provided direct evidence to the biodegradation of TBT by both Chlorella species. At the end of the experimental period, 27 and 41% of the original TBT were recovered as DBT and MBT in cultures of C. vulgaris, respectively. In contrast, DBT appeared to be the only degradation product of Chlorella sp. and only 26% of the original TBT was transformed to DBT. Despite the same genus, TBT was debutylated to a greater extent to MBT by C. vulgaris, while DBT was the end degradation product by Chlorella sp. The capability of such debutylating process therefore accounted for the higher tolerant ability of C. vulgaris than Chlorella sp.