Investigating the suitability of electrohydrodynamic lithography for the fabrication of cell substrates

We have investigated the feasibility of using electrohydrodynamic lithography (EHDL) to produce large lateral areas of patterned polymer substrates for use in biomedical applications. Half centimetered squared regions of uninterrupted patterning were obtained and characterised by profilometry and microscopy. The patterning was found to be elliptical in shape and was composed of concentric bands of distinct patterns centred on initial, randomly located nucleation sites. The size of the patterned area was limited by the degree to which the inter-electrode gap could be kept perfectly parallel, with a difference in height of just 15 nm influencing the patterning. Such sensitivity meant that issues such as the stiffness of the electrodes were important. Hierarchical patterning was achieved by combining EHDL with fracture-induced structuring. The substrates fabricated using EHDL were demonstrated to be viable for cell culture in vitro using fibroblast (3T3) and muscle (C2C12) cell lines.     

Blood speed imaging with an intraluminal array

In applications in which Doppler processing is not possible, such as side-looking intravascular imaging systems, decorrelation methods can be used to estimate blood speed. Here, a method is presented measuring relative blood speed using an FIR filter bank to estimate temporal decorrelation rates. It can be implemented in a modern commercially available ultrasound imaging system with no additional hardware. Both simulations and experiments using an intraluminal scanner appropriate for coronary artery applications have tested the system. In this study, the FIR filter bank is contrasted with previous methods, and its utility is further demonstrated with real-time color flow images from a pig model.     

Decorrelation characteristics of transverse blood flow along an intravascular array catheter

In recent years, a new method to measure transverse blood flow based on the decorrelation of radio frequency (RF) signals has been introduced. In this paper, we investigated the decorrelation characteristics of transverse blood flow measurement using an intravascular ultrasound (IVUS) array catheter by means of computer modeling. Blood was simulated as a collection of randomly located point scatterers. Moving this scattering medium transversally across the acoustical beam represented flow. First-order statistics were evaluated, and the signal-to-noise ratio from the signals was measured. The correlation coefficient method was used to present the results. The decorrelation patterns for RF and for RF-envelope signals were studied. The decorrelation patterns from the RF signals were in good agreement with those obtained from theoretical beam profiles. This agreement suggests that the decorrelation properties of an IVUS array catheter for measuring quantitative transverse blood flow can be assessed by measuring the ultrasound beam. A line of point scatterers, moved transversally across the acoustical beam (line spread function), can determine this decorrelation behaviour.     

CALL FOR PAPERS: Special Issue of Subsurface Sensing Technologies and Applications: An International Journal (SSTA Journal) on Sensor Technologies for Civil and Mechanical Systems

Call for Papers

CALL FOR PAPERS: Special Issue of Subsurface Sensing Technologies and Applications: An International Journal (SSTA Journal) on Sensor Technologies for Civil and Mechanical Systems     

Modernism sustained: Bucharest in the 1930s and 1990s

During the 1930s the social life of Bucharest rivalled that elsewhere in Europe. Culturally and artistically Bucharest embraced dynamic, innovative and avant-garde attitudes, which were prompted by the establishment of a Greater Romania after the end of the first World War. The artists Brancusi, Janco, Mary, the composer Enescu, the philosopher Eliade, were recognised internationally. The development of Bucharest was based on progressive theoretical ideas and over a period of ten years its appearance was transformed by modernist buildings. The individual villas and apartment buildings which formed the bulk of this transformation were achieved by private enterprise and represented an innovative architecture of social equilibrium which was entirely modernist; quite unlike the modernist social housing programmes elsewhere in Europe which were the products of state intervention and industry. By contrast, state and civic building programmes in Bucharest realised an architecture which retained classical conventions to become austere, sombre and repetitive. Since 1989, Romania has had to adjust to the rigours of market economics. The intervening fifty years of totalitarianism kept the achievements of the inter-war years under wraps, but these are now being rediscovered by a generation for whom they are the nearest representation of democracy on Romanian territory. The new-found democracy of the market place brings this period of cultural achievement into sharp focus, in the hope that it may act as a catalyst for the resolution of today's extensive urban deprivations.     

Drinking locations of drink-drivers: A comparative analysis of accident and nonaccident cases

This study utilizes data collected by the Perth (Australia) Traffic Police on the last drinking location of persons arrested for drink-driving either as a consequence of their being involved in a road traffic accident or as a result of failing a roadside breath test. A comparison of these data has found that significantly more persons involved in traffic accidents had been drinking at unlicensed locations, that is at private residences or in public places such as parks, than at licensed premises. It was also found that accident cases were more likely to involve males under 25 years; for those involved to have, on average, significantly higher blood alcohol levels than was the case for nonaccident drink-driving cases; and for most accidents to occur late at night and early morning. The significance of these findings were confirmed by logistic regression. A surprise incidental finding was that considerably more women had been arrested for drinkdriving than had been previously reported in other studies, both in Australia and overseas.     

Videourodynamic studies

Videourodynamic evaluation that incorporates radiographic imaging with simultaneous measurement of bladder and urethral pressure is the most precise method available for diagnosing complex incontinence and voiding disorders. In addition, videourodynamics has been instrumental to the development of our present knowledge about urethral and bladder function including the concepts of detrusor and abdominal leak point pressures. Although these studies are more expensive and time consuming, the authors have found videourodynamic evaluation indispensable when the diagnosis remains in question after simple urodynamics and when the studies and clinical scenario do not agree.