Molecular structure of Mg-Al, Mn-Al and Zn-Al halotrichites : an infrared spectroscopic study

Near infrared (NIR), X-ray diffraction (XRD) and infrared (IR) spectroscopy have been applied to halotrichites of the formula MgAl2(SO4)4∙22H2O, MnAl2(SO4)4∙22H2O and ZnAl2(SO4)4∙22H2O. Comparison of the halotrichites in different spectral regions has shown that the incorporation of a divalent transition metal into the halotrichite structure causes a shift in OH stretching band positions to lower wavenumbers. Therefore, an increase in hydrogen bonded water is observed for divalent cations with a larger molecular mass. XRD has confirmed the formation of halotrichite for all three samples and characteristic peaks of halotrichite have been identified at 18.5 and 24.5° 2θ, along with a group of six peaks between 5 and 15° 2θ. It has been observed that Mg-Al and Mn-Al halotrichite are very similar in structure, while Zn-Al showed several differences particularly in the NIR spectra. This work has shown that halotrichite structures can be synthesised and characterised by infrared and NIR spectroscopy.

Palliative care challenges : implications for nurses' practice in renal settings

The very act of withdrawing dialysis places renal nurses in a unique practice setting requiring a sudden shift in care delivery from one of providing Ife-sustaining, active treatment to that of palliation. The impact of this act on the renal nurse remains largely invisible. Minimal research has been conducted that explores the significant issues and challenges that exist for renal nurses in the delivery of palliation following withdrawal of dialysis treatment. This paper attempts to highlight the issues and challenges that do exist for renal nurses in providing palliation and the subsequent lack of available research knowledge to inform practice in the renal setting. It recommends further research be conducted into the renal setting so as to inform the development of appropriate education to support renal nurses practice in the future.

What information counts at the moment of practice? Information practices of renal nurses

Aims. This article is a report of a study done to identify how renal nurses experience information about renal care and the information practices that they used to support everyday practice. Background. What counts as nursing knowledge remains a contested area in the discipline yet little research has been undertaken. Information practice encompasses a range of activities such as seeking, evaluation and sharing of information. The ability to make informed judgement is dependent on nurses being able to identify relevant sources of information that inform their practice and those sources of information may enable the identification of what knowledge is important to nursing practice. Method. The study was philosophically framed from a practice perspective and informed by Habermas and Schatzki; it employed qualitative research techniques. Using purposive sampling six registered nurses working in two regional renal units were interviewed during 2009 and data was thematically analysed. Findings. The information practices of renal nurses involved mapping an information landscape in which they drew on information obtained from epistemic, social and corporeal sources. They also used coupling, a process of drawing together information from a range of sources, to enable them to practice. Conclusion. Exploring how nurses engage with information, and the role the information plays in situating and enacting epistemic, social and corporeal knowledge into everyday nursing practice is instructive because it indicates that nurses must engage with all three modalities in order to perform effectively, efficiently and holistically in the context of patient care. © 2011 The Authors. Journal of Advanced Nursing © 2011 Blackwell Publishing Ltd.

Lessons learnt : complementing good clinical renal questions with an appropriate research strategy

The purpose of this article is to present lessons learnt by nurses when conducting research to encourage colleagues to ask good clinical research questions. This is accomplished by presenting a study designed to challenge current practice which included research flaws. The longstanding practice of weighing renal patients at 0600 hours and then again prior to receiving haemodialysis was examined. Nurses believed that performing the assessment twice, often within a few hours, was unnecessary and that patients were angry when woken to be weighed. An observational study with convenience sampling collected data from 46 individuals requiring haemodialysis, who were repeatedly sampled to provide 139 episodes of data. Although the research hypotheses were rejected, invaluable experience was gained, with research and clinical practice lessons learnt, along with surprising findings.

Remembering the past : lessons for renal health care professionals (editorial)

There are many reasons to look back in time such as trying to learn from the past or to avoid repeating it. History also tells us where we have come from and how this has shaped the current environment in which we live, socialise and work. Renal health care has also been shaped by the past, and insights from the past can help us to face the challenges of the present, and in turn to see how the future might be.

Renal and genitourinary emergencies

Genitourinary (GU) problems are a common complaint in the community and to the emergency department (ED). Urinary tract infections (UTIs) are the second most common bacterial disease. UTIs rank as the sixteenth most frequently reported problem to general practitioners in Australia1 and between 10% and 20% of women will experience at least one UTI in their lifetime. Over 1,000,000 Australians are currently suffering with nephrolithiasis (renal calculi) and it is hy-pothesised that Australia’s hot, dry climate causes more stone formation than many other coun-tries in the world. Acute kidney injury (AKI) is a common complication of any trauma. Hypovol-aemia results in severe hypotension and this precipitates the development of acute tubular necrosis and subsequent AKI. The incidence of chronic kidney disease (CKD) is rising across the world. CKD is classified into five stages with those in stage 5 being classified as being in end stage kidney disease (ESKD). It is estimated that there are over 1.5 million people in Australia with CKD and there were over 16,000 Australians and over 2900 individuals in New Zealand with ESKD.2 Indigenous populations from both countries (Aboriginals, Torres Strait Islanders, Maoris, and Pacific Islanders) are over-represented in the number of people with all stages of CKD in both countries. Patients with compromised renal function often require the assistance of paramedics and will arrive at the ED with life-threatening fluid and electrolyte imbalances. Spe-cific GU emergencies discussed in this chapter are acute renal failure, rhabdomyolysis, chronic kidney disease, UTIs, acute urinary retention, urinary calculi, testicular torsion, epididymitis, and priapism. Refer to Chapter 31 for discussion of sexually transmitted infections (STIs) in women and to Chapter X for discussion of genitourinary trauma.

Letter to the editor : likelihood of tetraplegia after CT clearance of the cervical spine in obtunded blunt trauma patients

...the probabilistic computer simulation study by Dunham and colleagues evaluating the impact of different cervical spine management (CSM) strategies on tetraplegia and brain injury outcomes.1 Based on literature findings, expert opinion and with use of advances programming techniques the authors conclude that early collar removal without cervical spine magnetic resonance imaging (MRI) is a preferable CSM strategy for comatose, blunt trauma patients with extremity movement and a negative cervical spine computed tomography(CT) scan. Although we do not have the required expertise to comment on the applied statistical approach, we would like to comment on one of the medical assumptions raised by the authors, namely the likelihood of tetraplegia in this specific population....

Raman spectroscopy of selected tsumcorite Pb(Zn,Fe3+)2(AsO4)2(OH,H2O) minerals –implications for arsenate accumulation

The presence of arsenic in the environment is a hazard. The accumulation of arsenate by a range of cations in the formation of minerals provides a mechanism for the accumulation of arsenate. The formation of the tsumcorite minerals is an example of a series of minerals which accumulate arsenate. There are about twelve examples in this mineral group. Raman spectroscopy offers a method for the analysis of these minerals. The structure of selected tsumcorite minerals with arsenate and sulphate anions were analysed by Raman spectroscopy. Isomorphic substitution of sulphate for arsenate is observed for gartrellite and thometzekite. A comparison is made with the sulphate bearing mineral natrochalcite. The position of the hydroxyl and water stretching vibrations are related to the strength of the hydrogen bond formed between the OH unit and the AsO43- anion. Characteristic Raman spectra of the minerals enable the assignment of the bands to specific vibrational modes.

Renal bioenergetics during early gram-negative mammalian sepsis and angiotensin II infusion

Purpose: To measure renal adenosine triphosphate (ATP) (bioenergetics) during hypotensive sepsis with or without angiotensin II (Ang II) infusion. Methods: In anaesthetised sheep implanted with a renal artery flow probe and a magnetic resonance coil around one kidney, we induced hypotensive sepsis with intravenous Escherichia coli injection. We measured mean arterial pressure (MAP), heart rate, renal blood flow RBF and renal ATP levels using magnetic resonance spectroscopy. After 2 h of sepsis, we randomly assigned sheep to receive an infusion of Ang II or vehicle intravenously and studied the effect of treatment on the same variables. Results: After E. coli administration, the experimental animals developed hypotensive sepsis (MAP from 92 ± 9 at baseline to 58 ± 4 mmHg at 4 h). Initially, RBF increased, then, after 4 h, it decreased below control levels (from 175 ± 28 at baseline to 138 ± 27 mL/min). Despite decreased RBF and hypotension, renal ATP was unchanged (total ATP to inorganic phosphate ratio from 0.69 ± 0.02 to 0.70 ± 0.02). Ang II infusion restored MAP but caused significant renal vasoconstriction. However, it induced no changes in renal ATP (total ATP to inorganic phosphate ratio from 0.79 ± 0.03 to 0.80 ± 0.02). Conclusions:During early hypotensive experimental Gram-negative sepsis, there was no evidence of renal bioenergetic failure despite decreased RBF. In this setting, the addition of a powerful renal vasoconstrictor does not lead to deterioration in renal bioenergetics.

Biological responses of human bone marrow mesenchymal stem cells to Sr-M-Si (M = Zn, Mg) silicate bioceramics

Strontium (Sr), Zinc (Zn), magnesium (Mg), and silicon (Si) are reported to be essential trace elements for the growth and mineralization of bone. We speculated that the combination of these bioactive elements in bioceramics may be effective to regulate the osteogenic property of boneforming cells. In this study, two Sr-containing silicate bioceramics, Sr2ZnSi2O7 (SZS) and Sr2MgSi2O7 (SMS), were prepared. The biological response of human bone marrow mesenchymal stem cells (BMSCs) to the two bioceramics (in the forms of powders and dense ceramic bulks) was systematically studied. In powder form, the effect of powder extracts on the viability and alkaline phosphatase (ALP) activity of BMSCs was investigated. In ceramic disc form, both direct and indirect coculture of BMSCs with ceramic discs were used to investigate their biological response, including attachment, proliferation, ALP activity, and bone-related genes expression. Beta-tricalcium phosphate (b-TCP) and akermanite (Ca2MgSi2O7, CMS) were used as control materials. The results showed that the Sr, Zn, and Si (or Sr, Mg, and Si)-containing ionic products from SZS and SMS powders enhanced ALP activity of BMSCs, compared to those from b-TCP. Both SZS and SMS ceramic discs supported the growth of BMSCs, and most importantly, significantly enhanced the ALP activity and bone-related genes expression of BMSCs as compared to b-TCP. The results suggest that the specific combination of bioactive ions (Sr, Zn, Si, e.g.) in bioceramics is a viable way to improve the biological performance of biomaterials, and the form of materials and surface properties were nonnegligible factors to influence cell response.

Inhibition of guinea-pig renal [Na + K]-ATPase by normotensive human plasma : effects of a high sodium diet

The effect of plasma taken from normotensive humans, while on a low and high sodium diet, on [Na + K]-ATPase and 3H-ouabain binding was measured in tubules from guinea-pig kidneys. Plasma from the high sodium, compared to the low sodium, diet period: (a) inhibited [Na + K]-ATPase activity; (b) decreased 3H-ouabain affinity for binding sites; (c) increased the number of available 3H-ouabain binding sites; (d) decreased [Na + K]-ATPase turnover (activity/3H-ouabain binding sites). The inhibition of [Na + K]-ATPase suggests an increase in a (possible) natriuretic factor. The decreased affinity of 3H-ouabain binding suggests an endogenous ouabainoid, which may be the natriuretic factor.