Oblique derivative problems for elliptic equations on conical domains

We study the oblique derivative problem for uniformly elliptic equations on cone domains. Under the assumption of axi-symmetry of the solution, we find sufficient conditions on the angle of the oblique vector for Hölder regularity of the gradient to hold up to the vertex of the cone. The proof of regularity is based on the application of carefully constructed barrier methods or via perturbative arguments. In the case that such regularity does not hold, we give explicit counterexamples. We also give a counterexample to regularity in the absence of axi-symmetry. Unlike in the equivalent two-dimensional problem, the gradient Hölder regularity does not hold for all axi-symmetric solutions, but rather the qualitative regularity properties depend on both the opening angle of the cone and the angle of the oblique vector in the boundary condition

Validation of a Malay Version of the Patient-Rated Wrist Hand Evaluation (PRWHE-MV)

INTRODUCTION: The Patient-Rated Wrist Hand Evaluation (PRWHE) is a widely used measure of patient[1]reported disability, pain and appearance related to both hand and wrist disorders. It has been adapted cross[1]culturally worldwide but not in Malaysia. We performed a translation and cross-cultural adaptation of the PRWHE into a Malay version (PRWHE-MV) with assessed reliability and validity in patients presented with hand and/or wrist disorders. MATERIAL AND METHODS: PRWHE-MV was developed via translation and resolution of cultural discrepancies. A total of 83 patients (38 men, 45 women) with the mean age of 38 (SD 14) years and hand and/or wrist disorders completed both PRWHE-MV and the Malay version of Quick DASH during their first orthopaedic hand clinic follow up, and a second PRWHE-MV at 48 hours later. Intraclass Correlation Coefficient (ICC) was used to assess test-retest reliability of the PRWHE-MV while Cronbach’s alpha was calculated to assess the internal consistency. We tested the validity of PRWHE-MV against the Malay version of Quick DASH by calculating the nonparametric Spearman’s correlation coefficient between these two measures. RESULTS: There was no major cultural problems during the forward and backward translation of PRWHE, except for a minor change owing to cultural discrepancy in toilet hygiene. The Cronbach alpha PRWHE-MV was 0.978 (SEM = 5.5) at baseline and 0.979 (SEM = 5.35) at the second assessment. For the test-retest reliability, ICC was 0.99. There was a strong direct correlation between the scores for the PRWHE-MV and the Quick DASH (r = 0.916, p< 0.001). A majority of patients considered hand appearance somewhat important and were bothered in the past week. Their main concerns were gaining back normal hand function and subsequently returning to work. CONCLUSION: The PRWHE-MV showed high internal consistency, test-retest reliability and good validity in patients with hand and/or wrist disorders

Design and Analysis of a Novel Lightweight Translator Permanent Magnet Linear Generator for Oceanic Wave Energy Conversion

© 1965-2012 IEEE. At present, most of the linear generators contain a heavy translator for converting wave power from the ocean into electrical power. As the translator is connected to the buoy, the buoy dynamic performance is reduced by the large mass and, as a result, low velocity of the translator would degrade the electricity generation of the linear generator. This problem has been minimized by the new design in this paper, where the translator is clipped off at first and split into two separate portions to minimize its weight. The secondary stator is magnetically coupled with a special m-shaped main stator which is used to flow the necessary magnetic flux. The weight of the proposed translator is 21.82% lower than that of conventional one and 49.1% by using a recently available permanent magnet with higher specifications. The finite-element method is applied in ANSYS simulation environment for the analysis and comparison between the proposed and conventional designs. Different parameters of the conventional and the proposed linear generator have been discussed in this paper. The simulation results show that the proposed design can generate the same amount of electricity as the existing one with almost half of the translator size. According to the mathematical model, it is understood that the dynamics of the translator would be higher for its lower mass and vice versa. Therefore, minimizing the translator size would result in decrease of mass, which increases the dynamics of the buoy connected to the translator

Analysis and design of a novel linear generator for harvesting oceanic wave energy

© 2015 IEEE. In almost every permanent magnet linear generator (PMLG), demagnetization would greatly degrade the electricity generation capability over time. This paper proposes a novel PMLG which consists of a permanent magnet excitation generator (PMEG) to supply electrical excitation to the field winding of an electromagnetic linear generator (EMLG) which functions as the main power generator. The proposed generator can reduce the demagnetization problem of the conventional PMLG. The finite element analysis is performed by using the commercial software package ANSYS/ANSOFT for designing the proposed PMLG, and the genetic algorithm has been used to find the optimal pole size, pole pitch, air gap length and load variation to maximize the output power. Special m-shaped stator core is designed for the PMEG to minimize the leakage flux and cogging force. The voltage, current, power, magnetic flux density, force components and applied force are also analyzed and discussed

Oceanic Wave Energy Conversion by a Novel Permanent Magnet Linear Generator Capable of Preventing Demagnetization

© 1972-2012 IEEE. In the conventional permanent magnet linear generators (PMLGs) used for oceanic wave energy conversion system, demagnetization could cause everlasting degradation in electrical power generation. This paper presents a new design that can be applied to various PMLGs to avoid demagnetization. To check the effectiveness of the proposed technique, a PMLG is considered, which allows both the fixed and variable length of airgaps for analysis. The finite element analysis is used by using the software package ANSYS/Ansoft to simulate the testing PMLG for two conditions: with and without using the proposed technique. Different parameters and characteristics of the PMLG under both conditions are presented in detail. Both the simulation and test results show that the proposed design is able to avoid the demagnetization problem successfully

Effects of Pre-Natal Vitamin D Supplementation with Partial Correction of Vitamin D Deficiency on Early Life Healthcare Utilisation: A Randomised Controlled Trial

Funded by Asthma UK grant number 09/ 36

Plasma interleukin-6 concentration for the diagnosis of sepsis in critically ill adults

© 2019 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. Background The definition of sepsis has evolved over time, along with the clinical and scientific knowledge behind it. For years, sepsis was defined as a systemic inflammatory response syndrome (SIRS) in the presence of a documented or suspected infection. At present, sepsis is defined as a life-threatening organ dysfunction resulting from a dysregulated host response to infection. Even though sepsis is one of the leading causes of mortality in critically ill patients, and the World Health Organization (WHO) recognizes it as a healthcare priority, it still lacks an accurate diagnostic test. Determining the accuracy of interleukin-6 (IL-6) concentrations in plasma, which is proposed as a new biomarker for the diagnosis of sepsis, might be helpful to provide adequate and timely management of critically ill patients, and thus reduce the morbidity and mortality associated with this condition. Objectives To determine the diagnostic accuracy of plasma interleukin-6 (IL-6) concentration for the diagnosis of bacterial sepsis in critically ill adults. Search methods We searched CENTRAL, MEDLINE, Embase, LILACS, and Web of Science on 25 January 2019. We screened references in the included studies to identify additional studies. We did not apply any language restriction to the electronic searches. Selection criteria We included diagnostic accuracy studies enrolling critically ill adults aged 18 years or older under suspicion of sepsis during their hospitalization, where IL-6 concentrations were evaluated by serological measurement. Data collection and analysis Two review authors independently screened the references to identify relevant studies and extracted data. We assessed the methodological quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. We estimated a summary receiver operating characteristic (SROC) curve by fitting a hierarchical summary ROC (HSROC) non-linear mixed model. We explored sources of heterogeneity using the HSROC model parameters. We conducted all analyses in the SAS statistical software package and R software. Main results We included 23 studies (n = 4192) assessing the accuracy of IL-6 for the diagnosis of sepsis in critically ill adults. Twenty studies that were available as conference proceedings only are awaiting classification. The included participants were heterogeneous in terms of their distribution of age, gender, main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and origin of infection, among other factors. Prevalence of sepsis greatly varied across studies, ranging from 12% to 78%. We considered all studies to be at high risk of bias due to issues related to the index test domain in QUADAS-2. The SROC curve showed a great dispersion in individual studies accuracy estimates (21 studies, 3650 adult patients), therefore the considerable heterogeneity in the collected data prevented us from calculating formal accuracy estimates. Using a fixed prevalence of sepsis of 50% and a fixed specificity of 74%, we found a sensitivity of 66% (95% confidence interval 60 to 72). If we test a cohort 1000 adult patients under suspicion of sepsis with IL-6, we will find that 330 patients would receive appropriate and timely antibiotic therapy, while 130 patients would be wrongly considered to have sepsis. In addition, 370 out of 1000 patients would avoid unnecessary antibiotic therapy, and 170 patients would have been undiagnosed of sepsis. This numerical approach should be interpreted with caution due to the limitations described above. Authors’ conclusions Our evidence assessment of plasma interleukin-6 concentrations for the diagnosis of sepsis in critically ill adults reveals several limitations. High heterogeneity of collected evidence regarding the main diagnosis, setting, country, positivity threshold, sepsis criteria, year of publication, and the origin of infection, among other factors, along with the potential number of misclassifications, remain significant constraints for its implementation. The 20 conference proceedings assessed as studies awaiting classification may alter the conclusions of the review once they are fully published and evaluated. Further studies about the accuracy of interleukin-6 for the diagnosis of sepsis in adults that apply rigorous methodology for conducting diagnostic test accuracy studies are needed. The conclusions of the review will likely change once the 20 studies pending publication are fully published and included