112 research outputs found
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
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
A randomised controlled trial to compare the cost-effectiveness of tricyclic antidepressants, selective serotonin reuptake inhibitors and lofepramine
Aim/ Principal Research Question - The main aim of the “AHEAD” study was to determine the relative cost-effectiveness of three classes of antidepressants: tricyclics (TCAs), selective serotonin reuptake inhibitors (SSRIs), and the tricyclic-related antidepressant lofepramine, as first choice treatments for depression in UK primary care. Factors of interest - This is the first randomised prospective study in UK primary care to address this question. Most previous work on this topic has relied upon modelling and/or post hoc analysis of data collected for other purposes. The only other published trial of this type was conducted in HMOs in the United States.Methods - The study was an open label, pragmatic controlled trial with three randomised arms and one preference arm. Patients were followed up for a total of 12 months. Patients were randomised to receive a tricyclic antidepressant (amitriptyline, dothiepin, or imipramine), a selective serotonin reuptake inhibitor (fluoxetine, sertraline, or paroxetine), or lofepramine. Standardised recommendations about dose and dose escalation based on the BNF were issued to GPs. Cost effectiveness was based upon an analysis of direct costs from an NHS perspective.Sample groups - The study was carried out in UK primary care: 73 practices in urban and rural areas in Hampshire, Wiltshire, Dorset, Sussex, and Surrey agreed initially to take part. Patients with a new episode of depressive illness according to GP diagnosis were recruited. A total of 388 patients were referred to the study team by 87 GPs from 55 practices. Incremental cost-effectiveness ratios and cost-effectiveness acceptability curves (CEACs) were computed. Estimates were bootstrapped with 5000 replications.Outcome measures - At baseline the Clinical Interview Schedule, Revised (CIS-R PROQSY computerised version) was administered to establish symptom profiles. Outcome measures over 12 month follow-up included the Hospital Anxiety and Depression Scale self-rating of depression (HAD-D), CIS-R, EuroQol (EQ-5D) for quality of life, Short Form (SF-36) Health Survey for generic health status, and patient and practice records of use of health and social services (UHSS). The primary effectiveness outcome was the number of depression-free weeks (HAD-D less than 8, with interpolation of intervening values), and the primary cost outcome total direct NHS costs. Quality adjusted life years (QALYs) were used as the outcome measure in a secondary analysis. Findings - 327 patients were randomised. Follow-up rates were 68% at 3 months and 52% at 1 year. Linear regression analysis revealed no significant differences between groups in number of depression-free weeks when adjusted for baseline HAD-D. A higher proportion of patients randomised to TCAs entered the preference arm than those allocated to the other choices. Switching to another class of antidepressant in the first few weeks of treatment occurred significantly more often in the lofepramine arm and less in the preference arm. There were no significant differences between arms in mean cost per depression-free week. For values placed on an additional QALY of over £5,000, treatment with SSRIs was likely to be the most cost-effective strategy. Tricyclics were the least likely to be cost-effective as first choice of antidepressant for most values of a depression free week or QALY respectively, but these differences were relatively modest.Conclusion - Given the low probability of significant differences in cost-effectiveness, it is appropriate to base the first choice between these three classes of antidepressant in primary care on doctor and patient preferences. Adopting this policy may lead to less switching of medication subsequently. Choosing lofepramine is likely to lead to a greater proportion of patients switching treatment in the first few weeks.Implications for further research - It is difficult to see how a better study of this topic could be conducted in the primary care setting. The research agenda concerning the management of depression in primary care should move on to address important questions such as the most appropriate threshold of severity at which to commence antidepressant medication, the effectiveness of strategies to improve recognition of depression and quality of management of identified patients, and the efficacy of interventions to improve persistence in treatment taking by patients
Effect of educational intervention on medication timing in Parkinson's disease: a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Medicine usage in Parkinson's disease patients is often imperfect, in particular irregular timing of medication. The effect of informing Parkinson's disease patients about the continuous dopaminergic hypothesis (to encourage regular medicine intake) on medication adherence and motor control was tested.</p> <p>Methods</p> <p>Patients were randomised either to the active group (receiving the intervention) or control group (no extra information). Antiparkinson medicine usage was monitored for 3 months before and after the intervention using electronic pill bottles which record the date and time of opening (MEMS<sup>®</sup>, Aardex, Switzerland) and data used to calculate the percentage of doses taken at correct time intervals.</p> <p>Results</p> <p>43 patients (52%) were randomised to active counselling, and 40 (48%) were controls (standard management). The intervention effect (difference in timing adherence pre- to post-intervention between the 2 groups) was 13.4% (CI 5.1 to 21.7), p = 0.002. Parkinson motor scores did not change significantly (active group 0.1, CI -3.4 to 3.7) versus controls (4.5, CI 1.6 to 7.1), p = 0.06.</p> <p>Conclusion</p> <p>Timing adherence, but not motor scores, improves by providing patients with extra information. Therapy timing is of potential importance in Parkinson's disease management.</p> <p>Trial registration number</p> <p>NCT00361205</p
Psychological determinants of whole-body endurance performance
Background: No literature reviews have systematically identified and evaluated research on the psychological determinants of endurance performance, and sport psychology performance-enhancement guidelines for endurance sports are not founded on a systematic appraisal of endurance-specific research.
Objective: A systematic literature review was conducted to identify practical psychological interventions that improve endurance performance and to identify additional psychological factors that affect endurance performance. Additional objectives were to evaluate the research practices of included studies, to suggest theoretical and applied implications, and to guide future research.
Methods: Electronic databases, forward-citation searches, and manual searches of reference lists were used to locate relevant studies. Peer-reviewed studies were included when they chose an experimental or quasi-experimental research design, a psychological manipulation, endurance performance as the dependent variable, and athletes or physically-active, healthy adults as participants.
Results: Consistent support was found for using imagery, self-talk, and goal setting to improve endurance performance, but it is unclear whether learning multiple psychological skills is more beneficial than learning one psychological skill. The results also demonstrated that mental fatigue undermines endurance performance, and verbal encouragement and head-to-head competition can have a beneficial effect. Interventions that influenced perception of effort consistently affected endurance performance.
Conclusions: Psychological skills training could benefit an endurance athlete. Researchers are encouraged to compare different practical psychological interventions, to examine the effects of these interventions for athletes in competition, and to include a placebo control condition or an alternative control treatment. Researchers are also encouraged to explore additional psychological factors that could have a negative effect on endurance performance. Future research should include psychological mediating variables and moderating variables. Implications for theoretical explanations of endurance performance and evidence-based practice are described
Depression and Anxiety Correlate Differently with Salivary Free Cortisol in the Morning in Patients with Functional Somatic Syndrome
Patients presenting with functional somatic syndrome (FSS) are common, and the symptoms are persistent and difficult to treat for doctors and costly for society. The aim of this study was to clarify the common pathophysiology of FSS, especially the relationship between hypothalamic-pituitary-adrenal (HPA) axis function and psychological characteristics of patients with FSS. The subjects were 45 patients with FSS and 29 healthy controls. Salivary free cortisol was measured in the morning, and psychological tests examining depression, anxiety and quality of life (QOL) were performed on the same day. In patients with FSS, depressive scores showed a significant negative correlation with salivary free cortisol in the morning, although in healthy controls, cortisol showed a significant positive correlation with depressive scores. In addition, the correlation between other psychological test scores and cortisol secretion in patients with FSS contrasted with that of controls. The relationship between cortisol and depression, anxiety or QOL, suggests that the HPA axis of patients with FSS is dysfunctional and does not function properly when patients with FSS are under stress. This dysfunction may explain the pathology of medically unexplained persistent symptoms of patients with FSS
Patients' experiences of living with and receiving treatment for fibromyalgia syndrome: a qualitative study
<p>Abstract</p> <p>Background</p> <p>Fibromyalgia syndrome (FMS) presents a challenge for patients and health care staff across many medical specialities. The aetiology is multi-dimensional, involving somatic, psychological and social factors. Patients' views were obtained to understand their experience of living with this long-term condition, using qualitative interviews.</p> <p>Methods</p> <p>12 patients were recruited and stratified by age, gender and ethnicity from one rheumatology outpatient clinic, and a departmental held database of patients diagnosed with FMS.</p> <p>Results</p> <p>Patients' accounts of their experience of FMS resonated well with two central concepts: social identity and illness intrusiveness. These suggested three themes for the analytical framework: life before and after diagnosis (e.g. lack of information about FMS, invisibility of FMS); change in health identity (e.g. mental distress, impact on social life) and perceived quality of care (e.g. lack of contact with nurses, attitudes of specialists). The information provided from one male participant did not differ from the female patients, but black and ethnic community patients expressed a degree of suspicion towards the medication prescribed, and the attitudes displayed by some doctors, a finding that has not been previously reported amongst this patient group. Patients expected more consultation time and effective treatment than they received. Subjective experiences and objective physical and emotional changes were non-overlapping. Patients' accounts revealed that their physical, mental and social health was compromised, at times overwhelming and affected their identity.</p> <p>Conclusion</p> <p>FMS is a condition that intrudes upon many aspects of patients' lives and is little understood. At the same time, it is a syndrome that evokes uneasiness in health care staff (as current diagnostic criteria are not well supported by objective markers of physiological or biochemical nature, and indeed because of doubt about the existence of the condition) and places great demands on resources in clinical practice. Greater attention needs to be paid to the links between the explanatory models of patients and staff, and most important, to the interrelationship between the complex physical, psychological and social needs of patients with FMS. Taking a less medical but more holistic approach when drawing up new diagnostic criteria for FMS might match better individuals' somatic and psycho-social symptom profile and may result in more effective treatment.</p
A new family of urea-based low molecular-weight organogelators for environmental remediation : the influence of structure
Gelation processes grant access to a wealth of soft materials with tailorable properties, in applications as diverse as environmental remediation, biomedicene and electronics. Several classes of self-assembling gelators have been studied and employ non-covalent bonds to direct assembly, but recently attention has come to focus on how the overall shape of the gelator molecule impacts its gelation. Here we study a new sub-family of low molecular weight organogelators and explore how steric rearrangement influences their gelation. The gels produced are characterised with X-ray diffraction and Small- Angle neutron scattering (SANS) to probe their ex-situ and in-situ gelation mechanisms. The best examples were then tested for environmental remediation applications, gelling petrol and oils in the presence of water and salts
A strong association between non-musculoskeletal symptoms and musculoskeletal pain symptoms: results from a population study
<p>Abstract</p> <p>Background</p> <p>There is a lack of knowledge about the pattern of symptom reporting in the general population as most research focuses on specific diseases or symptoms. The number of musculoskeletal pain sites is a strong predictor for disability pensioning and, hence, is considered to be an important dimension in symptom reporting. The simple method of counting symptoms might also be applicable to non-musculoskeletal symptoms, rendering further dimensions in describing individual and public health. In a general population, we aimed to explore the association between self-reported non-musculoskeletal symptoms and the number of pain sites.</p> <p>Methods</p> <p>With a cross-sectional design, the Standardised Nordic Questionnaire and the Subjective Health Complaints Inventory were used to record pain at ten different body sites and 13 non-musculoskeletal symptoms, respectively, among seven age groups in Ullensaker, Norway (n = 3,227).</p> <p>Results</p> <p>Results showed a strong, almost linear relationship between the number of non-musculoskeletal symptoms and the number of pain sites (r = 0.55). The <it>number </it>and <it>type </it>of non-musculoskeletal symptoms had an almost equal explanatory power in the number of pain sites reported (27.1% vs. 28.2%).</p> <p>Conclusion</p> <p>The linear association between the number of non-musculoskeletal and musculoskeletal symptoms might indicate that the symptoms share common characteristics and even common underlying causal factors. The total burden of symptoms as determined by the number of symptoms reported might be an interesting generic indicator of health and well-being, as well as present and future functioning. Research on symptom reporting might also be an alternative pathway to describe and, possibly, understand the medically unexplained multisymptom conditions.</p
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