432 research outputs found

    3D Nanostructured Conjugated Polymers for Optical Applications

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    This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/adfm.201502392The self assembly of block-copolymers into the gyroid morphology was replicated into 3D nanostructured conjugated polymers. Voided styrenic gyroidal networks were used as scaffolds for the electrodeposition of two poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives and poly(pyrrole) (PPy). The careful choice of solvents and electrolytes allowed the excellent replication of the initial self-assembled morphology into self-supporting gyroidal conjugated polymer networks. The nanostructured films were employed to fabricate electrochromic devices, exhibiting excellent colour contrast upon switching, with fast switching speeds. The versatility and reliability of this method was demonstrated by the creation of switchable Fresnel zone plates, with which the focussing of light can be switched on and off.We acknowledge the EPSRC EP/G060649/1 for funding. This study was supported by the Nokia Research Centre Cambridge

    Measurement Duration but Not Distance, Angle, and Neighbour-Proximity Affects Precision in Enteric Methane Emissions when Using the Laser Methane Detector Technique in Lactating Dairy Cows

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    SIMPLE SUMMARY: Methane that is breathed out and eructed from ruminants is a potent greenhouse gas that contributes to climate change. Although metabolic chambers are the “gold standard” for measuring methane from livestock, their application in production farms is very limited. There is a need to develop proxy methods that can be applied in such production environments. The proprietary Laser Methane Detector (LMD) has been trialed for the previous decade and has demonstrated its usefulness as a non-invasive and portable instrument to determine methane output from ruminants. In validating the reliability and stability of the data generated by the LMD, the current study gives answers to some very practical assumptions used in the use of the LMD and enhances the confidence in its use in ruminants. ABSTRACT: The laser methane detector (LMD), is a proprietary hand-held open path laser measuring device. Its measurements are based on infrared absorption spectroscopy using a semiconductor laser as a collimated excitation source. In the current study, LMD measurements were carried out in two experiments using 20 and 71 lactating dairy cows in Spain and Scotland, respectively. The study aimed at testing four assumptions that may impact on the reliability and repeatability of the LMD measurements of ruminants. The study has verified that there is no difference in enteric methane measurements taken from a distance of 3 m than from those taken at a distance of 2 m; there was no effect to the measurements when the measurement angle was adjusted from 90° to 45°; that the presence of an adjacent animal had no effect on the methane measurements; and that measurements lasting up to 240 s are more precise than those taken for a shorter duration. The results indicate that angle, proximity to other animals, and distance had no effects and that measurements need to last a minimum of 240 s to maintain precision

    Soluble Isoforms of Vascular Endothelial Growth Factor Are Predictors of Response to Sunitinib in Metastatic Renal Cell Carcinomas

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    Angiogenesis is the target of several agents in the treatment of malignancies, including renal cell carcinoma (RCC). There is a real need for surrogate biomarkers that can predict selection of patients who may benefit from antiangiogenic therapies, prediction of disease outcome and which may improve the knowledge regarding mechanism of action of these treatments. Tyrosine kinase inhibitors (TKI) have proven efficacy in metastatic RCC (mRCC). However, the molecular mechanisms underlying the clinical response to these drugs remain unclear.The present study aimed to identify molecular biomarkers associated with the response to sunitinib, a Tyrosine kinase inhibitor. To evaluate this relationship, primary tumors from 23 metastatic RCC patients treated by sunitinib were analyzed for a panel of 16 biomarkers involved in tumor pathways targeted by sunitinib, using real-time quantitative reverse-transcriptase PCR. Nine of the 23 patients (39%) responded to sunitinib. Among transcripts analyzed, only the levels of vascular endothelial growth factor (VEGF) soluble isoforms (VEGF(121) and VEGF(165)) were associated with the response to sunitinib (P = 0.04 for both). Furthermore, the ratio of VEGF soluble isoforms (VEGF(121)/VEGF(165)) was significantly associated with prognosis (P = 0.02).This preliminary study provides a promising tool that might help in the management of metastatic RCC, and could be extended to other tumors treated by TKI

    Skin-impedance in Fabry Disease: A prospective, controlled, non-randomized clinical study

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    <p>Abstract</p> <p>Background</p> <p>We previously demonstrated improved sweating after enzyme replacement therapy (ERT) in Fabry disease using the thermo-regularity sweat and quantitative sudomotor axon reflex tests. Skin-impedance, a measure skin-moisture (sweating), has been used in the clinical evaluation of burns and pressure ulcers using the portable dynamic dermal impedance monitor (DDIM) system.</p> <p>Methods</p> <p>We compared skin impedance measurements in hemizygous patients with Fabry disease (22 post 3-years of bi-weekly ERT and 5 ERT naive) and 22 healthy controls. Force compensated skin-moisture values were used for statistical analysis. Outcome measures included 1) moisture reading of the 100<sup>th </sup>repetitive reading, 2) rate of change, 3) average of 60–110<sup>th </sup>reading and 4) overall average of all readings.</p> <p>Results</p> <p>All outcome measures showed a significant difference in skin-moisture between Fabry patients and control subjects (p < 0.0001). There was no difference between Fabry patients on ERT and patients naïve to ERT. Increased skin-impedance values for the four skin-impedance outcome measures were found in a small number of dermatome test-sites two days post-enzyme infusions.</p> <p>Conclusion</p> <p>The instrument portability, ease of its use, a relatively short time required for the assessment, and the fact that DDIM system was able to detect the difference in skin-moisture renders the instrument a useful clinical tool.</p

    Paracheck-PfÂź accuracy and recently treated Plasmodium falciparum infections: is there a risk of over-diagnosis?

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    BACKGROUND: An assessment of the accuracy of Paracheck Pf, a malaria rapid diagnostic test (RDT) detecting histidine rich protein 2 was undertaken amongst children aged 6-59 months in eastern Democratic Republic of Congo. METHODS: This RDT assessment occurred in conjunction with an ACT efficacy trial. Febrile children were simultaneously screened with both RDT and high quality microscopy and those meeting inclusion criteria were followed for 35 days. RESULTS: 358 febrile children were screened with 180 children recruited for five weeks follow-up. On screening, the RDT accurately diagnosed all 235 true malaria cases, indicating 100% RDT sensitivity. Of the 123 negative slides, the RDT gave 59 false-positive results, indicating 52.0% (64/123) RDT specificity. During follow-up after treatment with an artemisinin-based combination therapy, 98.2% (110/112), 94.6% (106/112), 92.0% (103/112) and 73.5% (50/68) of effectively treated children were still false-positive by RDT at days 14, 21, 28 and 35, respectively. CONCLUSION: Results show that though the use of Paracheck-Pf is as sensitive as microscopy in detecting true malaria cases, a low specificity did present a high frequency of false-positive RDT results. What's more, a duration of RDT false-positivity was found that significantly surpassed the 'fortnight' after effective treatment reported by its manufacturer. Though further research is needed in assessing RDT accuracy, study results showing the presence of frequent false positivity should be taken into consideration to avoid clinicians inappropriately focusing on malaria, not identifying the true cause of illness, and providing unnecessary treatment

    Treatment of Fabry Disease: Outcome of a Comparative Trial with Agalsidase Alfa or Beta at a Dose of 0.2 mg/kg

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    Two different enzyme preparations, agalsidase alfa (Replagal(TM), Shire) and beta (Fabrazyme(TM), Genzyme), are registered for treatment of Fabry disease. We compared the efficacy of and tolerability towards the two agalsidase preparations administered at identical protein dose in a randomized controlled open label trial.Thirty-four Fabry disease patients were treated with either agalsidase alfa or agalsidase beta at equal dose of 0.2 mg/kg biweekly. Primary endpoint was reduction in left ventricular mass after 12 and 24 months of treatment. Other endpoints included occurrence of treatment failure (defined as progression of cardiac, renal or cerebral disease), glomerular filtration rate, pain, anti-agalsidase antibodies, and globotriaosylceramide levels in plasma and urine. After 12 and 24 months of treatment no reduction in left ventricular mass was seen, which was not different between the two treatment groups. Also, no differences in glomerular filtration rate, pain and decline in globotriaosylceramide levels were found. Antibodies developed only in males (4/8 in the agalsidase alfa group and 6/8 in the agalsidase beta group). Treatment failure within 24 months of therapy was seen in 8/34 patients: 6 male patients (3 in each treatment group) and 2 female patients (both agalsidase alfa). The occurrence of treatment failures did not differ between the two treatment groups; chi(2) = 0.38 p = 0.54.Our study revealed no difference in reduction of left ventricular mass or other disease parameters after 12 and 24 months of treatment with either agalsidase alfa or beta at a dose of 0.2 mg/kg biweekly. Treatment failure occurred frequently in both groups and seems related to age and severe pre-treatment disease.International Standard Randomized Clinical Trial ISRCTN45178534 [http://www.controlled-trials.com/ISRCTN45178534]

    Standardized voluntary force measurement in a lower extremity rehabilitation robot

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    BACKGROUND: Isometric force measurements in the lower extremity are widely used in rehabilitation of subjects with neurological movement disorders (NMD) because walking ability has been shown to be related to muscle strength. Therefore muscle strength measurements can be used to monitor and control the effects of training programs. A new method to assess isometric muscle force was implemented in the driven gait orthosis (DGO) Lokomat. To evaluate the capabilities of this new measurement method, inter- and intra-rater reliability were assessed. METHODS: Reliability was assessed in subjects with and without NMD. Subjects were tested twice on the same day by two different therapists to test inter-rater reliability and on two separate days by the same therapist to test intra-rater reliability. RESULTS: Results showed fair to good reliability for the new measurement method to assess isometric muscle force of lower extremities. In subjects without NMD, intraclass correlation coefficients (ICC) for inter-rater reliability ranged from 0.72 to 0.97 and intra-rater reliability from 0.71 to 0.90. In subjects with NMD, ICC ranged from 0.66 to 0.97 for inter-rater and from 0.50 to 0.96 for intra-rater reliability. CONCLUSION: Inter- and intra- rater reliability of an assessment method for measuring maximal voluntary isometric muscle force of lower extremities was demonstrated. We suggest that this method is a valuable tool for documentation and controlling of the rehabilitation process in patients using a DGO

    Mucosal Lipocalin 2 Has Pro-Inflammatory and Iron-Sequestering Effects in Response to Bacterial Enterobactin

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    Nasal colonization by both gram-positive and gram-negative pathogens induces expression of the innate immune protein lipocalin 2 (Lcn2). Lcn2 binds and sequesters the iron-scavenging siderophore enterobactin (Ent), preventing bacterial iron acquisition. In addition, Lcn2 bound to Ent induces release of IL-8 from cultured respiratory cells. As a countermeasure, pathogens of the Enterobacteriaceae family such as Klebsiella pneumoniae produce additional siderophores such as yersiniabactin (Ybt) and contain the iroA locus encoding an Ent glycosylase that prevents Lcn2 binding. Whereas the ability of Lcn2 to sequester iron is well described, the ability of Lcn2 to induce inflammation during infection is unknown. To study each potential effect of Lcn2 on colonization, we exploited K. pneumoniae mutants that are predicted to be susceptible to Lcn2-mediated iron sequestration (iroA ybtS mutant) or inflammation (iroA mutant), or to not interact with Lcn2 (entB mutant). During murine nasal colonization, the iroA ybtS double mutant was inhibited in an Lcn2-dependent manner, indicating that the iroA locus protects against Lcn2-mediated growth inhibition. Since the iroA single mutant was not inhibited, production of Ybt circumvents the iron sequestration effect of Lcn2 binding to Ent. However, colonization with the iroA mutant induced an increased influx of neutrophils compared to the entB mutant. This enhanced neutrophil response to Ent-producing K. pneumoniae was Lcn2-dependent. These findings suggest that Lcn2 has both pro-inflammatory and iron-sequestering effects along the respiratory mucosa in response to bacterial Ent. Therefore, Lcn2 may represent a novel mechanism of sensing microbial metabolism to modulate the host response appropriately

    Non-allergic rhinitis: a case report and review

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    Rhinitis is characterized by rhinorrhea, sneezing, nasal congestion, nasal itch and/or postnasal drip. Often the first step in arriving at a diagnosis is to exclude or diagnose sensitivity to inhalant allergens. Non-allergic rhinitis (NAR) comprises multiple distinct conditions that may even co-exist with allergic rhinitis (AR). They may differ in their presentation and treatment. As well, the pathogenesis of NAR is not clearly elucidated and likely varied. There are many conditions that can have similar presentations to NAR or AR, including nasal polyps, anatomical/mechanical factors, autoimmune diseases, metabolic conditions, genetic conditions and immunodeficiency. Here we present a case of a rare condition initially diagnosed and treated as typical allergic rhinitis vs. vasomotor rhinitis, but found to be something much more serious. This case illustrates the importance of maintaining an appropriate differential diagnosis for a complaint routinely seen as mundane. The case presentation is followed by a review of the potential causes and pathogenesis of NAR

    Maternal educational level, parental preventive behavior, risk behavior, social support and medical care consumption in 8-month-old children in Malmö, Sweden

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    <p>Abstract</p> <p>Background</p> <p>The social environment in which children grow up is closely associated with their health. The aim of this study was to investigate the relationship between maternal educational level, parental preventive behavior, parental risk behavior, social support, and use of medical care in small children in Malmö, Sweden. We also wanted to investigate whether potential differences in child medical care consumption could be explained by differences in parental behavior and social support.</p> <p>Methods</p> <p>This study was population-based and cross-sectional. The study population was 8 month-old children in Malmö, visiting the Child Health Care centers during 2003-2007 for their 8-months check-up, and whose parents answered a self-administered questionnaire (n = 9,289 children).</p> <p>Results</p> <p>Exclusive breast feeding ≄4 months was more common among mothers with higher educational level. Smoking during pregnancy was five times more common among less-educated mothers. Presence of secondhand tobacco smoke during the first four weeks of life was also much more common among children with less-educated mothers. Less-educated mothers more often experienced low emotional support and low practical support than mothers with higher levels of education (>12 years of education). Increased exposure to unfavorable parental behavioral factors (maternal smoking during pregnancy, secondhand tobacco smoke and exclusive breastfeeding <4 months) was associated with increased odds of in-hospital care and having sought care from a doctor during the last 8 months. The odds were doubled when exposed to all three risk factors. Furthermore, children of less-educated mothers had increased odds of in-hospital care (OR = 1.34 (95% CI: 1.08, 1.66)) and having sought care from a doctor during the last 8 months (OR = 1.28 (95% CI: 1.09, 1.50)), which were reduced and turned statistically non-significant after adjustment for unfavorable parental behavioral factors.</p> <p>Conclusion</p> <p>Children of less-educated mothers were exposed to more health risks, fewer health-promoting factors, worse social support, and had higher medical care consumption than children with higher educated mothers. After adjustment for parental behavioral factors the excess odds of doctor's visits and in-hospital care among children with less-educated mothers were reduced. Improving children's health calls for policies targeting parents' health-related behaviors and social support.</p
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