Evaluation of photografted charged sites within polymer monoliths in capillary columns using contactless conductivity detection

Capacitively coupled contactless conductivity detection (C4D) is presented as a novel and versatile means of visualising discrete zones of charged functional groups grafted onto polymer based monoliths. Monoliths were formed within 100 μm UV transparent fused silica capillaries and photografting methods were subsequently used to graft a charged functional monomer, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto discrete regions of the “generic” monolith using a photomask. Post-modification monolith evaluation involves scanning the C4D detector along the length of the monolith to obtain a profile of the exact spatial location of grafted charged functionalities with millimetre accuracy. The methodology was extended to the visualisation of several zones of immobilised protein (bovine serum albumin) using photografted azlactone groups to enable covalent attachment of the protein to the monolith at precise locations along its length. In addition, the extent of non-specific binding of protein to the ungrafted regions of the monolith due to hydrophobic interactions could be monitored as an increase in background conductivity of the stationary phase. Finally, the technique was cross-validated using fluorescence microscopy by immobilising green fluorescent protein (GFP) in discrete zones and comparing the profiles obtained using both complementary techniques

Further shock tunnel studies of scramjet phenomena

Scramjet phenomena were studied using the shock tunnel T3 at the Australian National University. Simple two dimensional models were used with a combination of wall and central injectors. Silane as an additive to hydrogen fuel was studied over a range of temperatures and pressures to evaluate its effect as an ignition aid. The film cooling effect of surface injected hydrogen was measured over a wide range of equivalence. Heat transfer measurements without injection were repeated to confirm previous indications of heating rates lower than simple flat plate predictions for laminar boundary layers in equilibrium flow. The previous results were reproduced and the discrepancies are discussed in terms of the model geometry and departures of the flow from equilibrium. In the thrust producing mode, attempts were made to increase specific impulse with wall injection. Some preliminary tests were also performed on shock induced ignition, to investigate the possibility in flight of injecting fuel upstream of the combustion chamber, where it could mix but not burn

Noise diffraction patterns eliminated in coherent optical systems

Lens rotation technique of noise diffraction pattern elimination spreads diffracted energy, normally concentrated over small area of image, over much larger annular area. Technique advantages include simplified lens selecting process, reduced clean room requirements, and low cost equipment requirements

Gold nano-particle modified silica monolithic micro-columns for selected chromatographic and biological applications.

Monolithic microcolumns and especially silica monoliths are showing several advantages compared to classical particle packed and organic polymeric monolithic columns: ease of production and functionalisation, excellent mechanical and thermal stability. Morphology of the monolithic columns can easily be tuned by simply changing the compositions of reaction mixtures. High porosity and interconnected flow-through pores ensure low back pressures at higher flow rates so increasing reaction speeds. High salt resistance allows use water based buffer solutions without any swelling of the stationary phase, large biomolecules can be utilised and conditions to prevent denaturation and comformation changes of these biomolecules can be maintained. Introduction of gold nano-particles on the surfaces of silica monoliths allows increase of the surface areas and alows creation of new, exotic surfaces. Gold shows strong affinity towards thiol groups, which can be found in different biomolecules so utilisation of this phenomena would allow production of micro-reactors and bioreactors in order to mimic biological reactions happening in living organisms and large biological systems. Silica monoliths were synthesised using classical sol-gel process. In order to immobilise gold nano-particles, surfaces of the silica monoliths were amminated using standard silanisation reaction with 3-aminopropyl-methyl-diethoxysilane. 20 nm citrate stabilised gold nano-particles were immobilised on the surfaces afterwards. Depending on the desired application, gold nano-oparticle modified silica monoliths were functionalised afterwards. Immobilisation of ionic species such as amino acids and small peptides would allow creation of stationary phase for ion chromatography, retention of enzymes and other biologically active molecules would allow to create micro-reactors. Leaving gold nano-particles unmodified would make ideal stationary phase for micro-extraction. These modified monoliths were characterised using microscopy techniques, such as scanning electron microscopy (SEM) and field emission SEM. They were used to characterise morphology of the monoliths as well as to evaluate the coverage of the surface with gold nano-particles. The fabricated stationary phases were used for selected biological and chromatographic applications (incorporanting classical chromatographic techniques in order to evaluate the performance of these new modified monolithic materials)

Elimination of coherent noise in a coherent light imaging system

Optical imaging systems using coherent light introduce objectionable noise into the output image plane. Dust and bubbles on and in lenses cause most of the noise in the output image. This noise usually appears as bull's-eye diffraction patterns in the image. By rotating the lens about the optical axis these diffraction patterns can be essentially eliminated. The technique does not destroy the spatial coherence of the light and permits spatial filtering of the input plane

Examining the content validity of the Birthing Unit Design Spatial Evaluation Tool (BUDSET) within a woman-centred framework.

Introduction: The environment for birth influences women in labor. Optimal birthing environments have the potential to facilitate normal labor and birth. The measurement of optimal birth units is currently not possible because there are no tools. An audit tool, the Birth Unit Design Spatial Evaluation Tool (BUDSET), was developed to assess the optimality of birthing environments. The BUDSET is based on 4 domains (fear cascade, facility, aesthetics, support), each comprising design principles that are further differentiated into specific assessable design items. In the process of developing measurement tools, content validity must be established. The aim of this study was to establish the content validity of the BUDSET from the perspective of women and midwives. Methods: This was a mixed-methods study with a survey assessing agreement with BUDSET items and in-depth interviews. Survey results were analyzed using an item-level content validity index and a survey-level validity index. Interview data were analyzed using a directed content analysis approach. The study was conducted in 2 locations¿a major maternity hospital and a midwifery research center, both in Australia. Study participants were 10 women and 2 midwifery academics. Results: The survey revealed that content-related validity varied according to the BUDSET domain, with the domains of facility and support established as content valid by most participants. The domains of the fear cascade and aesthetic were less strong, particularly among pregnant women. Interview data analysis provided content validity evidence of both the fear cascade and aesthetic domains. A further 4 subthemes of fear cascade also were identified: foreign space, medical-hospital-emergency, being sterile/clinical, and protecting the woman from the environment. Content validity evidence for facility and support domains also was established. Discussion: This study has established that the BUDSET is content valid for assessing the optima ity of birthing environments. Some further refinement of the tool is now possible

Maternal mortality in Australia: Learning from maternal cardiac arrest

Cardiac arrest in pregnancy is fortunately a rare event that few midwives will see during their career. The increase in maternal age, the Body Mass Index, cesarean sections, multiple pregnancies, and comorbidities over recent years have increased the probability of cardiac arrest. The early warning signs of impending maternal cardiac arrest are either absent or go unrecognized. Maternal mortality reviews highlight the deficiencies that maternity care providers have in managing cardiac arrest in pregnancy. The aim of this article is to address the knowledge deficiencies of health professionals by reviewing the physiological changes in pregnant women that complicate the management of cardiopulmonary resuscitation, using a case scenario. There are key differences in the management of pregnant women, when compared to standard adult resuscitation. The outcome is dependent on the speed of the response and the consideration of a number of crucial pregnancy-specific interventions. Staff members need to be adequately trained in order to deal with maternal cardiac arrest and have access to training packages and in-service education programs. As cardiac arrest in pregnancy is a rare event, emergency drill simulations are an important component of ongoing education. © 2011 Blackwell Publishing Asia Pty Ltd.