212 research outputs found
Case reports: A helping hand to generalists
Clinical decision making can be challenging for both generalists and specialists. Case reports may assist the decision making process either by providing guidance to generalists on identifying rarer conditions or a searchable database for looking up seemingly disparate symptoms. This editorial highlights the innovations being implemented by Journal of Medical Case Reports and Cases Journal in developing an educational resource to help clinicians in decision-making
In situ formation of low molecular weight organogelators for slick solidification
We have investigated the in situ formation of Low Molecular Weight Organogelator (LMWO) molecules in oil-on-water slicks through dual reactive precursor injection. This method alleviates the need for any carrier solvent or prior heating, therefore reducing the environmental impact of LMWOs, giving instantaneous gelation, even at low temperatures (−5 °C). We show minimal leaching from our gels into the water layer
Effects of Various Commercially Available Enrichment Options on Handling and Chronic Stress Markers in Female ICR Mice
Although social housing of mice generally is preferred, mice must be individually housed in some situations. In these cases, enhanced attention to environmental enrichment is encouraged, but few studies assess the wellbeing of mice provided various enrichments. In this study, we used female ICR mice to evaluate enrichment strategies that encouraged natural behaviors including foraging, exercise, sheltering, and socialization. After 3 mo of exposure to the assigned enrichment strategy, wellbeing was assessed by evaluating behavioral and physiologic differences between groups. The results suggested that the use of red-tinted igloos may decrease markers of mouse wellbeing. However, none of the selected strategies yielded measures of wellbeing indicating improvement as compared to individually housed mice with no enrichment (negative control). Furthermore, measures were not significantly different between paired mice and individually housed mice with no enrichment
Whisky tasting using a bimetallic nanoplasmonic tongue
Metallic nanostructures are ideal candidates for optical tongue devices thanks to their chemical stability, the sensitivity of their plasmonic resonance to environmental changes, and their ease of chemical-functionalization. Here, we describe a reusable optical tongue comprised of multiplexed gold and aluminum nano-arrays; a bimetallic device which produces two distinct resonance peaks for each sensing region. Through specific modification of these plasmonic arrays with orthogonal surface chemistries, we demonstrate that a dual-resonance device allows us to halve sensor sizes and data-acquisition times when compared to single-resonance, monometallic devices. We applied our bimetallic tongue to differentiate off-the-shelf whiskies with > 99.7% accuracy by means of linear discriminant analysis (LDA). This advance in device miniaturization, functionalization, and multiplexed readout indicates nanoplasmonic tongues will have future applications in chemical mixture identification in applications where portability, reusability, and measurement speed are key
Photo-induced enhanced Raman spectroscopy as a probe for photocatalytic surfaces
Photo-induced enhanced Raman spectroscopy (PIERS) has emerged as a highly sensitive surface-enhanced Raman spectroscopy (SERS) technique for the detection of ultra-low concentrations of organic molecules. The PIERS mechanism has been largely attributed to UV-induced formation of surface oxygen vacancies (Vo) in semiconductor materials, although alternative interpretations have been suggested. Very recently, PIERS has been proposed as a surface probe for photocatalytic materials, following Vo formation and healing kinetics. This work establishes comparison between PIERS and Vo-induced SERS approaches in defected noble-metal-free titanium dioxide (TiO2-x) films to further confirm the role of Vo in PIERS. Upon application of three post-treatment methods (namely UV-induction, vacuum annealing and argon etching), correlation of Vo kinetics and distribution could be established. A proposed mechanism and further discussion on PIERS as a probe to explore photocatalytic materials are also presented. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 2)'
Photo-induced enhanced Raman spectroscopy (PIERS): Sensing atomic-defects, explosives and biomolecules
Enhanced Raman relies heavily on finding ideal hot-spot regions which enable significant enhancement factors. In
addition, the termed “chemical enhancement” aspect of SERS is often neglected due to its relatively low enhancement
factors, in comparison to those of electromagnetic (EM) nature. Using a metal-semiconductor hybrid system, with the
addition of induced surface oxygen vacancy defects, both EM and chemical enhancement pathways can be utilized on
cheap reusable surfaces. Two metal-oxide semiconductor thin films, WO3 and TiO2, were used as a platform for
investigating size dependent effects of Au nanoparticles (NPs) for SERS (surface enhanced Raman spectroscopy) and
PIERS (photo-induced enhanced Raman spectroscopy – UV pre-irradiation for additional chemical enhancement)
detection applications. A set concentration of spherical Au NPs (5, 50, 100 and 150 nm in diameter) was drop-cast on preirradiated metal-oxide substrates. Using 4-mercaptobenzoic acid (MBA) as a Raman reporter molecule, a significant
dependence on the size of nanoparticle was found. The greatest surface coverage and ideal distribution of AuNPs was
found for the 50 nm particles during SERS tests, resulting in a high probability of finding an ideal hot-spot region.
However, more significantly a strong dependence on nanoparticle size was also found for PIERS measurements –
completely independent of AuNP distribution and orientation affects – where 50 nm particles were also found to generate
the largest PIERS enhancement. The position of the analyte molecule with respect to the metal-semiconductor interface
and position of generated oxygen vacancies within the hot-spot regions was presented as an explanation for this result
Towards direct detection of tetracycline residues in milk with a gold nanostructured electrode
Tetracycline antibiotics are used extensively in veterinary medicine, but the majority of the administrated dose is eliminated unmodified from the animal through various excretion routes including urine, faeces and milk. In dairy animals, limits on residues secreted in milk are strictly controlled by legislation. Tetracyclines (TCs) have metal chelation properties and form strong complexes with iron ions under acidic conditions. In this study, we exploit this property as a strategy for low cost, rapid electrochemical detection of TC residues. TC-Fe(III) complexes in a ratio of 2:1 were created in acidic conditions (pH 2.0) and electrochemically measured on plasma-treated gold electrodes modified with electrodeposited gold nanostructures. DPV measurements showed a reduction peak for the TC-Fe(III) complex that was observed at 50 mV (vs. Ag/AgCl QRE). The limit of detection in buffer media was calculated to be 345 nM and was responsive to increasing TC concentrations up to 2 mM, added to 1 mM FeCl3. Whole milk samples were processed to remove proteins and then spiked with tetracycline and Fe(III) to explore the specificity and sensitivity in a complex matrix with minimal sample preparation, under these conditions the LoD was 931 nM. These results demonstrate a route towards an easy-to-use sensor system for identification of TC in milk samples taking advantage of the metal chelating properties of this antibiotic class
Collaborative care for depression in UK primary care: a randomized controlled trial
Reproduced with permission of the publisher. © 2008 Cambridge University Press.Background. Collaborative care is an effective intervention for depression which includes both organizational and
patient-level intervention components. The effect in the UK is unknown, as is whether cluster- or patient-randomization
would be the most appropriate design for a Phase III clinical trial.
Method. We undertook a Phase II patient-level randomized controlled trial in primary care, nested within a clusterrandomized
trial. Depressed participants were randomized to ‘collaborative care’ – case manager-coordinated medication
support and brief psychological treatment, enhanced specialist and GP communication – or a usual care control.
The primary outcome was symptoms of depression (PHQ-9).
Results. We recruited 114 participants, 41 to the intervention group, 38 to the patient-randomized control group and 35
to the cluster-randomized control group. For the intervention compared to the cluster control the PHQ-9 effect size was
0.63 (95% CI 0.18–1.07). There was evidence of substantial contamination between intervention and patient-randomized
control participants with less difference between the intervention group and patient-randomized control group (-2.99,
95% CI -7.56 to 1.58, p=0.186) than between the intervention and cluster-randomized control group (-4.64, 95% CI
-7.93 to -1.35, p=0.008). The intra-class correlation coefficient for our primary outcome was 0.06 (95% CI 0.00–0.32).
Conclusions. Collaborative care is a potentially powerful organizational intervention for improving depression treatment
in UK primary care, the effect of which is probably partly mediated through the organizational aspects of the
intervention. A large Phase III cluster-randomized trial is required to provide the most methodologically accurate test of
these initial encouraging findings
- …