ABSTRACT
We present a new and simple approach to fabricate wafer-scale, thin encapsulated, two-dimensional nanochannels by using conventional surface-micromachining technology and thin-film evaporation. The key steps to the realization of two-dimensional nanochannels are a fine etching of a sacrificial layer to create underetching spaces at the nanometer regime, and an accurate thin-film evaporation for encapsulation. Well-defined cross-sectional, encapsulated nanochannel arrays with dimensions as small as 20 nm in both width and height have been realized at the wafer-scale. The fabricated nanochannels with a channel length of 10mm have been used as a suitable fluidic platform for confining a solution containing nanomolar concentrations of Alexa fluorescent molecules. Initial results toward visualization of single Alexa molecules in the confined solution are reported.
Subject(s)
Fluorescent Dyes/analysis , Hydrazines/analysis , Microtechnology/methods , Nanostructures/ultrastructure , Microscopy, Fluorescence , Nanostructures/chemistryABSTRACT
We visualized individual quantum dots using a combination of a confining nanochannel and an ultra-sensitive microscope system, equipped with a high numerical aperture lens and a highly sensitive camera. The diffusion coefficients of the confined quantum dots were determined from the experimentally recorded trajectories according to the classical diffusion theory for Brownian motion in two dimensions. The calculated diffusion coefficients were three times smaller than those in bulk solution. These observations confirm and extend the results of Eichmann et al (2008 Langmuir 24 714-21) to smaller particle diameters and more narrow confinement. A detailed analysis shows that the observed reduction in mobility cannot be explained by conventional hydrodynamic theory.
ABSTRACT
INTRODUCTION: Australia is a land of cultural diversity. Cultural differences in maternity care may result in conflict between migrants and healthcare providers, especially when migrants have minimal English language knowledge. The aim of the study was to investigate Asian migrant women's child-birth experiences in a rural Australian context. METHOD: The study consisted of semi-structured interviews conducted with 10 Asian migrant women living in rural Tasmania to explore their childbirth experiences and the barriers they faced in accessing maternal care in the new land. The data were analysed using grounded theory and three main categories were identified: 'migrants with traditional practices in the new land', 'support and postnatal experiences' and 'barriers to accessing maternal care'. RESULTS: The findings revealed that Asian migrants in Tasmania faced language and cultural barriers when dealing with the new healthcare system. Because some Asian migrants retain traditional views and practices for maternity care, confusion and conflicting expectations may occur. Family and community play an important role in supporting migrant women through their maternity care. CONCLUSIONS: Providing interpreting services, social support for migrant women and improving the cross-cultural training for healthcare providers were recommended to improve available maternal care services.