Investigations into the analytical applications and fundamental chemistry of the chemiluminescent reactions of Tris(2,2'-bipyridyl)ruthenium(III) with certain Papaver Somniferum alkaloids and other related compounds

The reaction of tris(2,2’-bipyridyl)ruthenium(III) (Ru(bipy) ₃³⁺) with various analytes to generate chemiluminescence has been well documented. This investigation sought to undertake a chemiluminometic study of the reactions of Ru(bipy) ₃³⁺ with selected Papaver Somniferum alkaloids and specifically synthesised phenethylamines. The investigation, based on a kinetic study, primarily addressed the effect of varying reaction conditions (pH) on Ru(bipy) ₃³⁺ chemiluminescence production. To monitor these reactions, a batch chemiluminometer was specifically designed, fabricated and automated to conduct an extensive study on the selected compounds of interest. The instrumentation incorporated a custom built reaction cell and comprised an ‘on-line’ sample preparation system with which calibration standards could be automatically prepared. The instrumentation provided both time-independent (peak area) and time-dependent (kinetic profile) information. A novel approach to the stabilisation of Ru(bipy) ₃³⁺ as a chemiluminescencent reagent was also investigated and a recirculating system was employed with the batch chemiluminometer to provide a stable supply of Ru(bipy) ₃³⁺. Codeine, thebaine and 6-methoxy-codeine were the Papaver Somniferum alkaloids selected for this study and several N-methylated and N,N-dimethylated phenethylamines and methoxy-substituted phenetheylamines were also synthesised to investigate the affect of pH on the chemiluminescence emission efficiency. The versatility of the batch chemiluminometer facilitated the kinetic study of numerous analytes over a broad pH range. The exemplary performance of the chemiluminometer as an analytical instrument, was demonstrated by the calibration functions, based on peak area data, which exhibited excellent linearity and sensitivity. The estimated detection limits (3s) for the selected alkaloids were in the range 2 x 10^-9 M to 7 x 10^-9 at pH 5.0 and above, which compared favourably to detection limits for the same compounds determined using FIA. Relative standard deviations (n=5) for peak areas ranged between 1% to 5% with a mean of 3.1% for all calibration standards above 2.5 x 10^-8 M. Correlation between concentration and peak area, irrespective of pH and analyte was excellent, with all but two calibration functions having r-squared values greater than 0.990. The analytical figures of merit exemplified the precision and robustness of the reagent delivery and ‘on-line’ sample preparation, as well as the sensitivity of the system. The employment of the chemiluminometer for the measurement of total chemiluminescence emission (peak area) was in itself a feasible analytical technique, which generated highly reproducible and consistent data. Excellent analytical figures of merit, based on peak area, were similarly achieved for the phenethylamines. The effects of analyte structure on chemiluminescence activity was also investigated for the alkaloids and the phenethylamines. Subtle structural variations between the three alkaloids resulted in either a moderately reduced or enhanced total emission that was two or three fold difference only. A significant difference in reaction kinetics was observed between thebaine and codeine/6-methoxy-codeine, which was dependent upon pH. The time-dependent data, namely the observed rate constants for the initial rise in intensity and for the subsequent decay rate, were obtained by fitting a mathematical function (based on the postulated reaction mechanism) to the raw data. The determination of these rate constants for chemiluminescence reactions highlighted the feasibility for utilising such measurements for quantitative analytical applications. The kinetic data were used to discriminate between analyte responses in order to determine the concentrations of individual analytes in a binary mixture. A preliminary, multi-component investigation performed on a binary mixture of codeine and 6-methoxy-codeine (1:1) successfully determined the concentrations of these individual components using such rate constant measurements. Consequently, variations in kinetics resulted in a significant difference between the relative chemiluminescence response based on peak area measurements and the relative response base on peak height measurements obtained using FIA. With regards to the observed reactivity of secondary amines and tertiary amines, chemiluminescence peak area determinations confirmed the vital role of pH on reaction efficiency, which was governed by structural features and kinetics. The tertiary amines investigated generally produced a greater emission under acidic conditions than the corresponding secondary amines. However, the measured chemiluminescence responses were highly dependent upon pH, with similar peak areas obtained for both amine groups under slightly alkaline conditions.

Risk items associated with patient falls in oncology and medical settings

The aim of this study was to determine whether items on a falls risk-assessment tool, made up of brief cognitive and physical measures that nurses use in practice, differentiated fallers and nonfallers in oncology and medical settings. A measure of leg muscle strength clearly distinguished between fallers and nonfallers, with the latter having stronger leg muscles. For nursing practice, the assessment of patients' muscle strength seems to be the most useful scale for identifying potential fallers.

Chemical, biological and radiological incidents : preparedness and perceptions of emergency nurses

Despite their important role in chemical, biological and radiological (CBR) incident response, little is known about emergency nurses' perceptions of these events. The study aim was to explore emergency nurses' perceptions of CBR incidents and factors that may influence their capacity to respond. Sixty-four nurses from a metropolitan Emergency Department took part. The majority were willing to participate in CBR incidents and there was a positive association between willingness to participate and postgraduate qualification in emergency nursing. Willingness decreased, however, with unknown chemical and biological agents. One third of participants reported limitations to using personal protective equipment. Few participants had experience with CBR incidents although 70.3 per cent of participants had undergone CBR training. There were significant differences in perceptions of choice to participate and adequacy of training between chemical, biological and radiological incidents. The study results suggest that emergency nurses are keen to meet the challenge of CBR incident response.

Carbon nanotubes for biological and biomedical applications

Ever since the discovery of carbon nanotubes, researchers have been exploring their potential in biological and biomedical applications. The recent expansion and availability of chemical modification and bio-functionalization methods have made it possible to generate a new class of bioactive carbon nanotubes which are conjugated with proteins, carbohydrates, or nucleic acids. The modification of a carbon nanotube on a molecular level using biological molecules is essentially an example of the 'bottom-up' fabrication principle of bionanotechnology. The availability of these biomodified carbon nanotube constructs opens up an entire new and exciting research direction in the field of chemical biology, finally aiming to target and to alter the cell's behaviour at the subcellular or molecular level. This review covers the latest advances of bio-functionalized carbon nanotubes with an emphasis on the development of functional biological nano-interfaces. Topics that are discussed herewith include methods for biomodification of carbon nanotubes, the development of hybrid systems of carbon nanotubes and biomolecules for bioelectronics, and carbon nanotubes as transporters for a specific delivery of peptides and/or genetic material to cells. All of these current research topics aim at translating these biotechnology modified nanotubes into potential novel therapeutic approaches.

Health system reform and social capital

The pressures for health system reform have reached a critical stage over the past ten years as our understanding of the determinants of health has increased and deepened. Far from being conjecture and theory, the evidence for a broad range of determinants of health, from the biological and medical through to a broad range of economic and social determinants, has mounted.

Illness burden and medical comorbidity in the systematic treatment enhancement program for bipolar disorder

Objective:  Coexisting chronic medical conditions are common in bipolar disorder. Here, we report the prevalence and correlates of medical comorbidity in patients enrolled in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD). We were particularly interested in associations between variables reflecting illness chronicity and burden with comorbid medical conditions.

Method:  We used intake data from the open-label component of the STEP-BD. History of medical comorbidity was obtained from the affective disorders evaluation, and its presence was the outcome of interest. The sample size in analyses varied from 3399 to 3534. We used multiple Poisson regression to obtain prevalence ratios.

Results:  The prevalence of any medical comorbidity in the sample was 58.8%. In addition to demographic variable, several clinical characteristics were associated with the frequency of medical comorbidity. Having more than 10 previous mood episodes, childhood onset, smoking, lifetime comorbidity with anxiety, and substance use disorders were independently associated with having a medical comorbidity in the final multivariate model.

Conclusion:  The results presented here reveal strong associations between variables related to illness chronicity and medical burden in bipolar disorder. This lends further support to recent multidimensional models incorporating medical morbidity as a core feature of bipolar disorder.

Material world: learning and teaching chemistry

 In the Australian National Curriculum, the science understanding of overarching ideas of matter and energy covers science topics in the conceptual area of chemistry, such as the properties, forms and uses of different materials, the states of matter (solid, liquid and gas), and energy, such as forces, movement and electricity. This chapter focusses on explaining the abstract science ideas related to matter and energy through the use of appropriate vocabulary, examining ways of organising knowledge and linking scientific models and theories to observations and experiences. The particle model of matter is used to explain common observations, demonstrating the value of scientific inquiry and the role of models and representations in scientific thinking. A directed inquiry teaching approach in which there is a focus on the use of representations is recommended for these abstract topics. Representations are a vital component of communicating the abstract ideas of matter and energy. The use of the pedagogical approach in which students construct and evaluate representations of scientific ideas is used in the negotiation and development of their understandings.

The effect of a rapid heating rate, mechanical vibration and surfactant chemistry on the structure-property relationships of epoxy/clay nanocomposites

The role of processing conditions and intercalant chemistry in montmorillonite clays on the dispersion, morphology and mechanical properties of two epoxy/clay nanocomposite systems was investigated in this paper. This work highlights the importance of employing complementary techniques (X-ray diffraction, small angle X-ray scattering, optical microscopy and transmission electron microscopy) to correlate nanomorphology to macroscale properties. Materials were prepared using an out of autoclave manufacturing process equipped to generate rapid heating rates and mechanical vibration. The results suggested that the quaternary ammonium surfactant on C30B clay reacted with the epoxy during cure, while the primary ammonium surfactant (I.30E) catalysed the polymerisation reaction. These effects led to important differences in nanocomposite clay morphologies. The use of mechanical vibration at 4 Hz prior to matrix gelation was found to facilitate clay dispersion and to reduce the area fraction of I.30E clay agglomerates in addition to increasing flexural strength by over 40%.

Complexities of medicines safety: communicating about managing medicines at transition points of care across emergency departments and medical wards

To explore how health professionals, patients and family members communicate about managing medicines across transition points of care in two Australian public hospitals.

Integrating biological and social values when prioritizing places for biodiversity conservation

The consideration of information on social values in conjunction with biological data is critical for achieving both socially acceptable and scientifically defensible conservation planning outcomes. However, the influence of social values on spatial conservation priorities has received limited attention and is poorly understood. We present an approach that incorporates quantitative data on social values for conservation and social preferences for development into spatial conservation planning. We undertook a public participation GIS survey to spatially represent social values and development preferences and used species distribution models for 7 threatened fauna species to represent biological values. These spatially explicit data were simultaneously included in the conservation planning software Zonation to examine how conservation priorities changed with the inclusion of social data. Integrating spatially explicit information about social values and development preferences with biological data produced prioritizations that differed spatially from the solution based on only biological data. However, the integrated solutions protected a similar proportion of the species' distributions, indicating that Zonation effectively combined the biological and social data to produce socially feasible conservation solutions of approximately equivalent biological value. We were able to identify areas of the landscape where synergies and conflicts between different value sets are likely to occur. Identification of these synergies and conflicts will allow decision makers to target communication strategies to specific areas and ensure effective community engagement and positive conservation outcomes.

Clinical review criteria and medical emergency teams: evaluating a two-tier rapid response system

OBJECTIVES: To assess the prevalence of patients fulfilling clinical review criteria (CRC), to determine activation rates for CRC assessments, to compare baseline characteristics and outcomes of patients who fulfilled CRC with patients who did not, and to identify the documented nursing actions in response to CRC values. DESIGN, SETTING AND PARTICIPANTS: A cross-sectional study using a retrospective medical record audit, in a universityaffiliated, tertiary referral hospital with a two-tier rapid response system in Melbourne, Australia. We used a convenience sample of hospital inpatients on general medical, surgical and specialist service wards admitted during a 24-hour period in 2013. MAIN OUTCOME MEASURES: Medical emergency team (MET) or code blue activation, unplanned intensive care unit admissions, hospital length of stay and inhospital mortality. For patients who fulfilled CRC or MET criteria during the 24- hour period, the specific criteria fulfilled, escalation treatments and outcomes were collected. RESULTS: Of the sample (N = 422), 81 patients (19%) fulfilled CRC on 109 occasions. From 109 CRC events, 66 patients (81%) had at least one observation fulfilling CRC, and 15 patients (18%) met CRC on multiple occasions. The documented escalation rate was 58 of 109 events (53%). The number of patients who fulfilled CRC and subsequent MET call activation criteria within 24 hours was significantly greater than the number who did not meet CRC (P < 0.001). CONCLUSIONS: About one in five patients reached CRC during the study period; these patients were about four times more likely to also fulfil MET call criteria. Contrary to hospital policy, escalation was not documented for about half the patients meeting CRC values. Despite the clarity of escalation procedures on the graphic observation chart, escalation remains an ongoing problem. Further research is needed on the impact on patient outcomes over time and to understand factors influencing staff response.