996 resultados para pre-column derivatization


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A simple derivatization methodology is shown to extend the application of surface-enhanced Raman spectroscopy (SERS) to the detection of trace concentration of contaminants in liquid form. Normally in SERS the target analyte species is already present in the molecular form in which it is to be detected and is extracted from solution to occupy sites of enhanced electromagnetic field on the substrate by means of chemisorption or drop-casting and subsequent evaporation of the solvent. However, these methods are very ineffective for the detection of low concentrations of contaminant in liquid form because the target (ionic) species (a) exhibits extremely low occupancy of enhancing surface sites in the bulk liquid environment and (b) coevaporates with the solvent. In this study, the target analyte species (acid) is detected via its solid derivative (salt) offering very significant enhancement of the SERS signal because of preferential deposition of the salt at the enhancing surface but without loss of chemical discrimination. The detection of nitric acid and sulfuric acid is demonstrated down to 100 ppb via reaction with ammonium hydroxide to produce the corresponding ammonium salt. This yields an improvement of ∼4 orders of magnitude in the low-concentration detection limit compared with liquid phase detection.

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Aims: Pre-pregnancy care reduces the risk of adverse pregnancy outcomes in women with diabetes, yet the majority of women receive suboptimal care due to poor preconception counselling rates and a lack of awareness about the importance of specialised pre-pregnancy care. The primary aim was to develop a continuing professional development (CPD) resource for healthcare professionals (HCPs) who work with women with diabetes to facilitate preconception counselling with this group.

Methods: The website was developed under the direction of a multidisciplinary team, adhering to NICE guidelines. The tone, key messages and format are informed by the “Women with Diabetes” preconception counselling website, www.womenwithdiabetes.net, an existing resource which is effective in helping women to be better prepared for pregnancy.Results: This e-learning resource will give HCPs the necessary knowledge and tools to prepare women with diabetes to plan for pregnancy. The website features women with diabetes sharing their views and experiences, alongside an evidence-based commentary and key messages from research papers and clinical guidelines. It comprises two modules: “Planning for Pregnancy”, focusing on contraception, risks and planning; and “Diabetes and Pregnancy”, focusing on support during pregnancy with an overview of each trimester of pregnancy.

Conclusion: This website will be a useful CPD resource for all HCPs working with women with diabetes, providing a certificate on completion. This resource will empower HCPs to engage in preconception counselling with women with diabetes by providing the HCP with a greater understanding of the specific needs of women with diabetes both preconception and during pregnancy.

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As pre-registration nurse education programmes evolve within the United Kingdom, it is imperative to involve patient/client groups within the research process, as the outcome may invoke a change in the care delivery of the registered nurse (RN). This paper focuses upon children and how children might hypothetically contribute to informing a generic nursing programme in their capacity as a rights holder and expert in their own lives. Even though their contribution and value has been debated around their capacity as research advisor, research participant and co researcher, this paper explores how the child's view of their experience of hospital and of the good nurse could be best captured. Research is a powerful vehicle that can enable their voice to equally inform UK nurse educators and policy makers so that the child's health care needs are effectively met in hospital by RN's who complete a generic programme.

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A procedure was developed to extract polyols and trehalose (protectants against stress) from fungal conidia. Conidia were sonicated (120 s) and immersed in a boiling water bath (5.5 min) to optimize extraction of polyols and trehalose, respectively. A rapid method was developed to separate and detect low-molecular-weight polyols and trehalose using high-performance liquid chromatography (HPLC). An ion exchange column designed for standard carbohydrate analysis was used in preference to one designed for sugar alcohol separation. This resulted in rapid elution (less than 5 min), without sacrificing peak resolution. The use of a pulsed electrochemical detector (gold electrode) resulted in limits of reliable quantification as low as 1.6 μg ml-1 for polyols and 2.8 μg ml-1 for trehalose. This is very sensitive and rapid method by which these protectants can be analysed. It avoids polyol derivatization that characterizes analysis by gas chromatography and the long run times (up to 45 min) that typify HPLC analysis using sugar alcohol columns.

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Intravenous sedation is a widely used pharmacological method of patient management commonly used in dental surgery for the treatment of anxious patients. Variety exists in fasting regimes between different centres offering dental sedation, with some advocating starvation in line with general anaesthesia protocols and others not enforcing starvation at all. The currently available guidelines on fasting protocols are ambiguous and open to interpretation partly because they are based on expert opinion rather than evidence-based research. This article reviews the available evidence on the subject of pre-operative fasting and discusses current guidelines.

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This article reveals the effect of plasma pre-treatment on antimony tin oxide (ATO) nanoparticles. The effect is to allow Pt@Pd to be deposited homogeneously on the ATO surface with high dispersion and narrow particle size distribution. The Pt@Pd core–shell catalyst was prepared using the polyol method and shows a dramatic improvement towards ORR activity and durability.