bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating Load Transfer in Ceramic Reinforcements
Authors: Warren Peter , Ghosh Ranajay , Jahan Sanjida , Raghavan Seetha
Published: August 2018

Ceramic composites are critical to advance the performance of engines, reducing weight and enhancing fuel efficiency in their use as structural parts or protective coatings. Understanding load transfer between the reinforcements and matrix materials that constitute these composites hold the key to elucidating their mechanical properties and consequent behavior in operation. In this work, finite element (FE) simulations of loading effects on representative embedded alumina particles in a matrix were investigated and compared with experimental results. Mechanical loading effects on alumina nanoparticle composites can be captured with Photo stimulated luminescent spectroscopy (PSLS), where spectral shifts from the particles are monitored with load. The resulting piezospectroscopic (PS) coefficients are then used to calculate load transfer between the matrix and particle. The results from the simulation and experiments are shown to be in general agreement of increase in load transferred with increasing particle volume fraction due to contact stresses that are dominant at these higher volume fractions. Results from this work present a combination of analytical and experimental insight into the effect of particle volume fraction on load transfer in ceramic composites that can serve to determine properties and eventually optimize various parameters such as particle shape, size and dispersion that govern the design of these composites prior to manufacture and testing.
Combustion Dynamics Monitoring Considerations for Systems With Autotuning
Authors: Emerson Benjamin , Perullo Chris , Lieuwen Tim , Sheppard Scott , Kee Jared , Noble David , Angello Leonard
Published: August 2018

Gas turbine autotuning systems are surfacing as a popular OEM and third party solution to minimize manual tuning for emissions compliance, combustion dynamics, and performance optimization. While these systems provide many valuable benefits, they also introduce new challenges. This paper presents a review of autotuning systems, including the general approaches, benefits, challenges, and best practices for combustion dynamics monitoring. The primary benefit of autotuning is that it provides a mostly automated solution to address operability/emissions challenges which arise due to changes in ambient conditions, fuel composition, and machine aging. The operability and emissions challenges include compliant NOx and CO, acceptable combustion dynamics levels, acceptable operability (i.e., turndown and lean blowout avoidance), and in some cases optimized performance. The overarching potential benefit of autotuning systems is their ability to address all of these issues simultaneously and continuously. The paper first presents a brief outline of the general tuning considerations for autotuning systems, with some examples from real plant data to illustrate the tuning sensitivities. It next reviews the major challenges that autotuning can introduce to combustion dynamics monitoring, such as combustor fault pattern recognition and greater consequences of instrumentation faults. Finally, the paper recommends best practices for monitoring combustion dynamics in systems with autotuning. These recommendations include what to do (and what not to do) to continue health monitoring with advanced pattern recognition software, and how to recognize the signatures of combustion dynamics instrumentation faults. This paper is directed at gas turbine operators. It presents familiar plant data to help this audience understand the core working principles of an autotuning system. This understanding is an important basis for determining when a combustion dynamics event is attributable to the operations of the autotuning system, an instrumentation fault, or combustion system hardware degradation. With this understanding established, this paper also presents a list of capabilities and best practices that should be incorporated into combustion dynamics monitoring strategies for units that use autotuning.
Turbine Vane Leading Edge Impingement Cooling With a Sweeping Jet
Authors: Agricola Lucas , Hossain Mohammad A. , Ameri Ali , Gregory James W. , Bons Jeffrey P.
Published: August 2018

A low speed linear cascade was used to investigate sweeping jet impingement cooling in a nozzle guide vane leading edge at an engine-relevant Biot number. Sweeping and steady jets were studied at varying mass flow rates and freestream turbulence intensities. Infrared thermography and a thermal inertia technique were used to determine the overall cooling effectiveness and internal heat transfer coefficients of the impingement cooling configurations. The circular jet array provided higher overall effectiveness values at both freestream turbulence intensities. The sweeping jet array provided a broader heat transfer profile due to the spreading of the jet. Pressure drop was measured for each jet geometry, and the circular jet was found to have less pressure drop than the sweeping jet at a given mass flow rate.
Accurate Prediction of Loss Using High Fidelity Methods
Authors: Przytarski Pawel J. , Wheeler Andrew P. S.
Published: August 2018

Further improvements in aero-engine efficiencies require accurate prediction of flow physics and incurred loss. Currently, the computational requirements for capturing these are not known leading to inconsistent loss predictions even for scale-resolving simulations depending on the chosen convergence criteria. This work investigates two aspects of loss generation using high-fidelity simulation. In the first case study we look at the effect of numerical resolution on capturing viscous dissipation by simulating a Taylor-Green vortex canonical flow. The second case study focuses on the effect of flow physics on loss generation and uses a transitional compressor cascade subjected to freestream turbulence.
The Effect of Stratification Ratio on the Macrostructure of Stratified Swirl Flames: Experimental and Numerical Study
Authors: Han Xiao , Laera Davide , Morgans Aimee S. , Lin Yuzhen , Sung Chih-Jen
Published: August 2018

The present article reports experimental and numerical analyses of the macrostructures featured by a stratified swirling flame for varying stratification ratio (SR). The studies are performed with the Beihang Axial Swirler Independently-Stratified (BASIS) burner, a novel double-swirled full-scale burner developed at Beihang University. Experimentally, it is found that depending on the ratio between the equivalence ratios of the methane-air mixtures from the two swirlers, the flame stabilizes with three different shapes: attached V–flame, attached stratified flame and lifted flame. In order to better understand the mechanisms leading to the three macrostructures, large eddy simulations (LES) simulations are performed via the open source Computational Fluid Dynamics software OpenFOAM using the incompressible solver Reacting Foam. Changing the SR, simulation results show good agreement with experimentally observed time-averaged flame shapes, demonstrating that the incompressible LES are able to fully characterize the different flame behaviours observed in stratified burners. When the LES account for heat loss from walls, they better capture the experimentally observed flame quenching in the outer shear layer. Finally, insights into the flame dynamics are provided by analysing probes located near the two separate streams.
Evaluating Configurations of Double Surface Helical Groove Seals Using Computational Fluid Dynamics
Authors: Watson Cori , Wood Houston
Published: August 2018

Helical groove seals are non-contacting annular seals used in pumps and other rotating machinery to reduce the flow of working fluid across a pressure differential. These seals have continuously cut grooves, like the threads of a screw, across the surface of the rotor, the stator, or both surfaces. They function to reduce the flow of working fluid by two physical mechanisms. First, fluid traveling in the axial direction dissipates kinetic energy as it expands in the grooves and then is forced to contract in the jet stream region between the grooves. Second, the fluid within the grooves is displaced toward the high pressure region through the pumping action of the helical grooves. In multistage pump design, it is now common to use helical groove seals with grooves on both the surface of the rotor and stator where the grooves are opposing in direction. That is, the case where the grooves on the rotor pump towards the outlet, but the grooves on the stator pump towards the inlet. Despite this being the industry standard, no data in the literature exist that suggests that this design is better than other possible double surface helical groove seal configurations. This work examines the conditions in which each configuration of double surface helical groove seals is preferable. To accomplish this, simulations are run using ANSYS CFX for a variety of operating conditions for each configuration. The operating conditions varied are pressure differential and rotor speed. The baseline design of this data is a validated against experimental results from the literature showing the performance of opposing groove direction helical groove seals. This paper also discusses the validity of the multi-reference frame steady-state setup that can be used to efficiently simulate these seals. Finally, this study presents discussion and conclusions of the preference to opposing direction helical groove seals based on the flow mechanisms of the seal configurations. This work will form the basis of future work designing computationally efficient analysis tools to analyze these double surface helical groove seals, which are already widely used but lack computational analysis tools.
Microchannel Heat Exchanger Flow Validation Study
Authors: Lance Blake W. , Carlson Matthew D.
Published: August 2018

Flow maldistribution in microchannel heat exchanger (MCHEs) can negatively impact heat exchanger effectiveness. Several rules of thumb exist about designing for uniform flow, but very little data are published to support these claims. In this work, complementary experiments and computational fluid dynamics (CFD) simulations of MCHEs enable a solid understanding of flow uniformity to a higher level of detail than previously seen. Experiments provide a validation data source to assess CFD predictive capability. The traditional semi-circular header geometry is tested. Experiments are carried out in a clear acrylic MCHE and water flow is measured optically with particle image velocimetry. CFD boundary conditions are matched to those in the experiment and the outputs, specifically velocity and turbulent kinetic energy profiles, are compared.
Scale Adaptive Simulation of Transient Behavior in a Transonic Centrifugal Compressor With a Vaned Diffuser
Authors: Zamiri Ali , Chung Jin Taek
Published: August 2018

Three-dimensional, compressible, unsteady Navier-Stokes equations are solved to investigate the unsteady flow behavior in a transonic centrifugal compressor. The computational model is a high compression ratio centrifugal compressor (4:1) consisted of an inlet duct, an impeller (15 main blades and 15 splitters) and a diffuser vane with 24 two-dimensional wedge vanes.

The aim of this study is to conduct a comprehensive assessment of the ability of a hybrid scale-adaptive simulation (SAS) turbulent model to characterize the transient flow structures within the compressor passages. The main idea of SAS approach, an improved URANS (unsteady Reynold-averaged Navier-Stokes) model, is based on the introduction of von Karman length scale into the turbulent scale equation which results in LES-like behavior in unsteady regions of the flow field. A numerical sensitivity test is performed to validate the computational results in terms of pressure ratio and compressor efficiency. Instantaneous and mean flow field analyses are presented in the impeller and the vaned diffuser. Applying transient simulations, it is shown that the interaction between the pressure waves and the surface pressure of the diffuser blades leads to a pulsating behavior within the diffuser. Moreover, spectral analysis is evaluated to analyze the BPF tonal noise as the main noise source of centrifugal compressors. In addition, the current SAS results are compared with those of the URANS-SST (shear stress transport) approach to show the ability of SAS approach in the prediction of the turbulent structures where the SAS model leads to a much better resolution of the unsteady fluctuations.

This study shows that the current SAS approach, as an alternative to the existing hybrid RANS/LES methods, is promising in terms of prediction of transient phenomena like LES, but with a substantially reduced turn-around time.
Exploring the Impact of Manufacturing Geometric Uncertainties on the Aerodynamic Performance of a Small Scale Compressor
Authors: Manohara Selvan Kailash , Kowalczyk Lukasz
Published: August 2018

The performance of small scale compressors mass-produced for domestic appliances is influenced by geometric manufacturing uncertainty which affects overall product performance and reliability. Precise manufacturing processes through tighter tolerances ensure high geometric accuracy and lower compressor performance spread, but it challenges high volume production capabilities and cost. Good understanding of geometric sensitivities is necessary for robust design and tolerance definition.

This paper presents the application of geometric Sensitivity Analysis (SA), Uncertainty Quantification (UQ) and robust optimization method to a small scale compressor. Geometric SA was carried out on parametric blade geometry and the key influential parameters were identified. The tip clearance was found to be the most influential parameter followed by a blade surface thickness. The tip section of the blade was more influential than hub section and the suction surface was found to be more important than the pressure surface. Findings from the SA were used to define parameters that were measured and controlled to ensure impeller quality during production. Within the parametric bounds studied, impeller chord did not feature as a critical parameter. The machining tool path was optimized accordingly and a 12% reduction in cutting time was achieved. The numerical sensitivities were also compared with experimental data and a trend-level agreement was seen. Meta-models for aerodynamic performance were built using DoE generated geometries which were used to perform manufacturing UQ using a Monte Carlo estimator. Robust design optimization was carried out using stochastic optimization algorithm coupled with the meta-model based Monte-Carlo simulator. This framework was used to choose a robust nominal shape that achieved 18% lower standard deviation in stage pressure rise. The predicted performance spread was compared with production data and a satisfactory agreement was seen.
A Comparison of Clutch Types for Naval Propulsion
Authors: Bos J. J. , Mangnus J. , Bellamy N.
Published: August 2018

Naval applications require various modes of operation from a combination of driving sources to different ship propulsion systems. Various gear configurations are available for these applications. The driver types and operating modes generate different requirements for the selected clutch design. In this paper the application of different types of clutches will be compared for their specific applications, advantages and disadvantages.
A new method for ocular ultrasound examination
Authors: Berná-Serna Juan de Dios , Chico-Sánchez Pablo , Berná-Mestre Juan de Dios , Carbonell-López del Castillo Guillermo
Published: August 2018

.
Case Study: Long-Term Low-Carbohydrate, High-Fat Diet Impairs Performance and Subjective Well-Being in a World-Class Vegetarian Long-Distance Triathlete
Authors: Mujika Iñigo
Published: August 2018

The aim of this case study was to report on the performance outcomes and subjective assessments of long-term low-carbohydrate, high-fat (LCHF) diet in a world-class long-distance triathlete who had been suffering from gastrointestinal distress in Ironman competition. The lacto-ovo vegetarian athlete (age = 39 years; height = 179 cm; usual racing body mass = 75 kg; sum of seven skinfolds = 36 mm) changed his usual high carbohydrate (CHO) availability diet to an LCHF diet for 32 weeks (∼95% compliance). He participated in three professional races while on the LCHF diet, but acutely restored CHO availability by consuming CHO in the preevent meals and during the race as advised. The athlete had his worst-ever half-Ironman performance after 21 weeks on the LCHF diet (18th). After 24 weeks on LCHF, he had his second worst-ever Ironman performance (14th) and suffered his usual gastrointestinal symptoms. He did not finish his third race after 32 weeks on LCHF. He regained his usual performance level within 5 weeks back on a high CHO diet, finishing second and fourth in two Ironman events separated by just 3 weeks. Subjective psychological well-being was very negative while on the LCHF diet, with feelings of depression, irritability, and bad mood. In conclusion, this long-term (32 weeks) LCHF intervention did not solve the gastrointestinal problems that the athlete had been experiencing, it was associated with negative performance outcomes in both the half-Ironman and Ironman competitions, and it had a negative impact on the athlete’s subjective well-being.
Exclusion of Trunk Region Reduces Biological Error but Increases Technical Error of DXA Lean Soft Tissue Estimates From Nonfasted Assessments
Authors: Tinsley Grant M. , Nickerson Brett S.
Published: August 2018

Implementation of an overnight fast is a pervasive recommendation prior to body composition assessment, but this is not always feasible. Previous research has indicated that for dual-energy X-ray absorptiometry (DXA) scans, the trunk region may be particularly susceptible to biological error induced by food and fluid intake. This analysis explored the potential utility of excluding the trunk region from nonfasted DXA scans. Recreationally active adults were assessed by DXA after an overnight fast and again after consumption of standardized high-carbohydrate and low-carbohydrate diets. The effects of food consumption on total and appendicular lean soft tissue (LST; ALST) and ALST-derived skeletal muscle mass (SMM) were evaluated via analysis of variance, and metrics of reliability were calculated. In both conditions, the constant error of nonfasted assessments was slightly lower when the trunk was excluded (ALST and SMM: 0.7–1.2%; LST: 1.5%). However, in both conditions, the total error, standard error of the estimate, and limits of agreement were higher for ALST and SMM (total error: 2.4–3.0%; standard error of the estimate: 2.2–2.8%; and limits of agreement: 4.5–5.6%) than LST (total error: 2.1%; standard error of the estimate: 1.3–1.4%; and limits of agreement: 2.5–2.8%) when expressed relative to mean values. The added technical error due to demarcation of body regions for ALST and SMM appears to outweigh the removal of biological error due to exclusion of the trunk. Although elimination of the trunk region is theoretically appealing for nonfasted DXA assessments, it is apparently an inferior method compared with utilizing whole-body LST.
Social Media as a Nutrition Resource for Athletes: A Cross-Sectional Survey
Authors: Bourke Bridget Ellen Philippa , Baker Dane Francis , Braakhuis Andrea Jane
Published: August 2018

Social media contains a wealth of nutrition information and proposes a cost-effective, highly engaging platform to deliver nutrition information to athletes. This study used an online questionnaire to determine whether New Zealand athletes are using social media as a source of nutrition information and to understand perceptions of social media as a nutrition resource. Quantitative data were analyzed using t tests, chi-squared tests, and logistic regression analysis. Inductive thematic analysis was adopted for the qualitative data. From the 306 athletes who completed the questionnaire, 65% reported social media use for nutrition purposes in the past 12 months. Social media use was predicted by both athlete status and gender. Female athletes were more likely to have used social media for nutrition purposes (odds ratio = 2.7, 95% confidence interval [1.52, 4.62], p = .001) than males. Elite athletes were less likely to have used social media for nutrition (odds ratio = 0.44, 95% confidence interval [0.24, 0.83], p = .011) than recreational athletes. Athletes commonly used social media for practical nutrition purposes, including recipes and information about restaurants/cafes. Perceived advantages of social media as a nutrition resource included ease of access, well-presented information, personal connectedness, and information richness. Athletes’ primary concern for obtaining nutrition information from social media was information unreliability.
The Alzheimer's gamble
Authors: Kaiser Jocelyn
Published: August 2018

Can the National Institute on Aging turn a funding windfall into a treatment for the dreaded brain disease?
Response to Comment on “Innovative scattering analysis shows that hydrophobic disordered proteins are expanded in water”
Authors: Riback Joshua A. , Bowman Micayla A. , Zmyslowski Adam , Knoverek Catherine R. , Jumper John , Kaye Emily B. , Freed Karl F. , Clark Patricia L. , Sosnick Tobin R.
Published: August 2018

Best
et al
. claim that we provide no convincing basis to assert that a discrepancy remains between FRET and SAXS results on the dimensions of disordered proteins under physiological conditions. We maintain that a clear discrepancy is apparent in our and other recent publications, including results shown in the Best
et al
. comment. A plausible origin is fluorophore interactions in FRET experiments.
A president amplifies unlikely activists
Climate Justice
Mary Robinson
Bloomsbury, 2018. 176 pp.
Authors: Fabiani Louise
Published: August 2018

In dispatches from the front lines of global warming, Mary Robinson pushes for humane climate policies
Revolutionary technologies
Authors: Berg Jeremy
Published: August 2018

In this issue of
Science
, we present reviews of four technologies whose power and rapid growth across biological research communities make them revolutionary (see page 864). New technology is one of the most powerful drivers of scientific progress. For example, the earliest microscopes magnified images only 50-fold at most. When the Dutch fabric merchant and amateur scientist Antonie van Leeuwenhoek developed microscopes with more than 200-fold magnifications (likely to examine cloth), he used them to study many items, including pond water and plaque from teeth. His observations of “animalcules” led to fundamental discoveries in microbiology and cell biology, and spurred the elaboration of improved microscopes. Today, various light microscopes remain prime tools in modern biology. This example embodies two characteristics of a revolutionary technology: a capability for addressing questions better than extant technologies, and the possibility of being utilized and adapted by many other investigators.
Antibiotic-Resistant Escherichia coli and Class 1 Integrons in Humans, Domestic Animals, and Wild Primates in Rural Uganda
Authors: Weiss Debora , Wallace Ryan M. , Rwego Innocent B. , Gillespie Thomas R. , Chapman Colin A. , Singer Randall S. , Goldberg Tony L.
Published: August 2018

Antibiotic resistance is a global problem. This study, conducted in rural western Uganda, describes antibiotic resistance patterns in
Escherichia coli
bacteria near two forested national parks. Resistance was present not only in people, but also in their livestock and in nearby wild nonhuman primates. Multidrug resistance and class 1 integrons containing genes that confer resistance were common and were similar in people and animals. The percentage of resistant isolates decreased with increasing local price of the antibiotic. Antibiotic resistance in this setting likely reflects environmental diffusion of bacteria or their genes, perhaps facilitated by local ecological and socioeconomic conditions.
Prevalence and Characterization of Heterogeneous Variable-Number Tandem-Repeat Clusters Comprising Drug-Susceptible and/or Variable Resistant Mycobacterium tuberculosis Complex Isolates in the Netherlands from 2004 to 2016
Authors: Roof Inge , Jajou Rana , Kamst Miranda , Mulder Arnout , de Neeling Albert , van Hunen Rianne , van der Hoek Wim , van Soolingen Dick
Published: August 2018

The variable-number tandem-repeat (VNTR) typing method is used to study tuberculosis (TB) transmission. Clustering of
Mycobacterium tuberculosis
isolates with identical VNTR patterns is assumed to reflect recent transmission.
Role-Playing Activity to Demonstrate Diffusion Across a Cell Membrane
Authors: Harrison Elizabeth
Published: August 2018

Transport of molecules across the cell plasma membrane can be a difficult concept for introductory biology students to understand and visualize. Role-playing activities provide a simple, cost-effective method for enhancing student understanding of various challenging biological concepts. This cell membrane role-playing activity was designed to teach introductory biology students how small nonpolar and polar molecules cross the cell membrane as well as the importance of diffusion, osmosis, and tonicity.
Role of Capsid Anchor in the Morphogenesis of Zika Virus
Authors: Rana Jyoti , Slon Campos José Luis , Leccese Gabriella , Francolini Maura , Bestagno Marco , Poggianella Monica , Burrone Oscar R.
Published: August 2018

The capsid anchor (Ca) is a single-pass transmembrane domain at the C terminus of the capsid protein (C) known to function as a signal for the translocation of PrM into the ER lumen. The objective of this study was to further examine the role of Ca in Zika virus life cycle, whether involved in the formation of nucleocapsid through association with C or in the formation of viral envelope. In this study, we show that Ca has a function beyond the one of translocation signal, controlling protein E stability and therefore its availability for assembly of infectious particles.
Perinatally acquired HIV-positive status disclosure and associated factors in Dire Dawa and Harar, Eastern Ethiopia: a health facility-based cross-sectional study
Authors: Mengesha Melkamu Merid , Dessie Yadeta , Roba Aklilu Abrham
Published: August 2018

Objectives

The aim of this study was to assess the level and factors associated with caregivers’ disclosure of perinatally HIV-infected (PHIV+) children’s seropositive status.

Design

We conducted a cross-sectional study in five public health facilities providing HIV treatment and care in Dire Dawa and Harar, Eastern Ethiopia. The data were collected from 310 caregivers through face-to-face interviews and record reviews. Data analyses were done using STATA V.14.2 and statistical significance was declared at p value <0.05.

Results

The study revealed that the level of PHIV+ diagnosis disclosure was 49.4% (95% CI 43.8 to 54.9). Mean age at disclosure was 11.2 years. Disclosure level was higher among children who frequently asked about their health status (aOR (adjusted OR) 2.04, 95% CI 1.04 to 4.03) and when caregivers knew other people who had a disclosure experience (aOR 2.49, 95% CI 1.17 to 5.32). Disclosure level was less among children of 12 years or below (aOR 0.04, 95% CI 0.02 to 0.09) and among caregivers practising deception about the children’s HIV positive status (aOR 0.38, 95% CI 0.19 to 0.74).

Conclusion

Only half of the caregivers disclosed their child’s PHIV+ diagnosis. To facilitate disclosure, caregivers should be counselled about the appropriate age of disclosure and related misconceptions that hinder it. It is also apparent that caregivers need to be guided as to how to address children’s frequent questions about their health status. These interventions can be made in a one-on-one approach or through patient group counselling when they come to get healthcare services.
Effect of vitamin D on ventricular remodelling in heart failure: a meta-analysis of randomised controlled trials
Authors: Zhao Jin-Dong , Jia Jing-Jing , Dong Ping-Shuan , Zhao Di , yang Xu-Ming , Li Dao-Lin , Zhang Hui-Feng
Published: August 2018

Objectives

The level of vitamin D is considered to be associated with the development and progression of heart failure (HF). However, it is still unclear whether supplementation of vitamin D could improve ventricular remodelling in patients with HF. This study aimed to systematically evaluate the influence and safety of additional vitamin D supplementation on ventricular remodelling in patients with HF.

Design

This study is a meta-analysis of randomised controlled trials (RCTs).

Setting

The PubMed, EMBASE, CNKI, Cochrane library, Web of Science databases and grey literature were searched for RCTs regarding the effect of vitamin D on ventricular remodelling in patients with HF (from database creation to October 2017). RevMan V.5.3 software was employed for data analysis.

Participants

Seven RCTs with a total of 465 patients, including 235 cases in the vitamin D group and 230 cases in the control group, were included.

Primary and secondary outcome measures

Left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF) and the incidence of adverse reactions.

Results

Compared with the control group, a decrease in the LVEDD (mean difference (MD)=−2.31 mm, 95% CI −4.15 to −0.47, p=0.01) and an increase in the LVEF (MD=4.18%, 95% CI 0.36 to 7.99, p=0.03) were observed in the vitamin D group. Subgroup analysis also revealed a reduced LVEDD in adults (>18 years) and adolescents (<18 years) of the vitamin D group relative to that in those of the control group. High-dose vitamin D (>4000 IU/day) was more effective at reducing the LVEDD than low-dose vitamin D (<4000 IU/day). Moreover, vitamin D supplementation was more effective at reducing the LVEDD and increasing the LVEF in patients with reduced ejection fraction than in patients without reduced ejection fraction.

Conclusion

Vitamin D supplementation inhibits ventricular remodelling and improves cardiac function in patients with HF.

Trial registration number

CRD42017073893.
Validating traditional Chinese syndrome features in varied stages of chronic gastritis malignant transformation: study protocol for a cross-sectional study
Authors: Zhang Yin , Liu Yue , Song Rui , Zhang Li , Su Zeqi , Li Yannan , Chen Runhua , Shi Ning , Zhao Xia , Du Shiyu , Ding Xia
Published: August 2018

Introduction

The transition from chronic non-atrophic gastritis (CNAG) to chronic atrophic gastritis (CAG) and gastric carcinoma (GC) is regarded as a representative disease model of gastric mucosa malignant transformation led by uncontrolled inflammation. Traditional Chinese medicine (TCM) syndrome-targeted therapies have been applied in treating chronic gastritis (CG) malignant transformation in China with satisfying efficacy. This study aims to validate TCM syndrome features in each stage of CG malignant transformation. The findings may shed light on the TCM hypothesis of CG malignant transformation, and thus optimise syndrome-targeted treatment strategies of CNAG, CAG and GC, respectively.

Methods and analysis

The present study is a cross-sectional study conducted in China. A total of 2000 eligible patients, including 500 CNAG cases, 1000 CAG cases and 500 GC cases, will be recruited from four TCM hospitals. Primary outcome measures include the prevalence of TCM syndrome patterns in varied stages of CG malignant transformation. Secondary outcome measures include prevalence and severity of all the presenting signs and symptoms collected by using TCM four diagnostic methods. Descriptive analysis, comparative analysis and correlation analysis of all the measurement data will be performed by biostatisticians. Unsupervised data mining analyses, including exploratory factor analysis, association rule analysis, hierarchical clustering analysis, complex system entropy clustering analysis, and so on, will also be performed by data scientists respectively for in-depth analyses of TCM syndrome-related indicators.

Ethics and dissemination

The protocol has been approved by the Ethical Review Board of Dongzhimen Hospital Affiliated to Beijing University of Chinese Medicine (No ECPJ-BDY-2014-02). All the study outcomes will be disseminated through national conference reports and in the meantime published on peer-reviewed journals.

Trial registration number

NCT03314038; Pre-results.
Defining good health and care from the perspective of persons with multimorbidity: results from a qualitative study of focus groups in eight European countries
Authors: Leijten Fenna R M , Hoedemakers Maaike , Struckmann Verena , Kraus Markus , Cheraghi-Sohi Sudeh , Zemplényi Antal , Ervik Rune , Vallvé Claudia , Huiĉ Mirjana , Czypionka Thomas , Boland Melinde , Rutten-van Mölken Maureen P M H
Published: August 2018

Objectives

The prevalence of multimorbidity is increasing in many Western countries. Persons with multimorbidity often experience a lack of alignment in the care that multiple health and social care organisations provide. As a response, integrated care programmes are appearing. It is a challenge to evaluate these and to choose appropriate outcome measures. Focus groups were held with persons with multimorbidity in eight European countries to better understand what good health and a good care process mean to them and to identify what they find most important in each.

Methods

In 2016, eight focus groups were organised with persons with multimorbidity in: Austria, Croatia, Germany, Hungary, the Netherlands, Norway, Spain and the UK (total n=58). Each focus group followed the same two-part procedure: (1) defining (A) good health and well-being and (B) a good care process, and (2) group discussion on prioritising the most important concepts derived from part one and from a list extracted from the literature. Inductive and deductive analyses were done.

Results

Overall, the participants in all focus groups concentrated more on the care process than on health. Persons with multimorbidity defined good health as being able to conduct and plan normal daily activities, having meaningful social relationships and accepting the current situation. Absence of shame, fear and/or stigma, being able to enjoy life and overall psychological well-being were also important facets of good health. Being approached holistically by care professionals was said to be vital to a good care process. Continuity of care and trusting professionals were also described as important. Across countries, little variation in health definitions were found, but variation in defining a good care process was seen.

Conclusion

A variety of health outcomes that entail well-being, social and psychological facets and especially experience with care outcomes should be included when evaluating integrated care programmes for persons with multimorbidity.
Prospective cohort study of overweight and obesity among rural Indian adults: sociodemographic predictors of prevalence, incidence and remission
Authors: Rai Rajesh Kumar , Jaacks Lindsay M , Bromage Sabri , Barik Anamitra , Fawzi Wafaie W , Chowdhury Abhijit
Published: August 2018

Objectives

To assess sociodemographic predictors of prevalence, incidence and remission of overweight including obesity among adults (aged ≥18 years) in rural Eastern India.

Design

Prospective cohort study.

Setting

Birbhum Health and Demographic Surveillance System, West Bengal, India.

Participants

Self-weighted sample of 24 115 adults (men: 10915, women: 13200) enrolled in 2008 were followed up for body mass index (BMI) reassessment in 2017.

Primary and secondary outcome measures

Measured BMI was categorised as: underweight (<18.5 kg/m2), normal weight (18.5–22.9 kg/m2) and overweight including obesity (≥23 kg/m2; hereinafter overweight). Incident overweight was defined as transition from normal weight in 2008 to overweight in 2017, whereas if overweight individuals in 2008 measured normal BMI in 2017, it was classified as remission from overweight.

Results

In 2008, 10.1% of men and 14.6% of women were overweight, whereas 17.3% of men and 24.7% of women were overweight in 2017. At the same time, in 2017, 35.6% of men and 33.3% of women were underweight. Incident overweight was 19.0% among men and 27.2% among women, whereas remission among men was higher (15.4%) than women (11.5%). Women were more likely to be overweight in 2008 and to experience incident overweight than men. For men and women, education level and wealth were positively associated with prevalence and incidence of overweight. Remission from overweight was less likely in Sainthia, a business hub in the district, as compared with Mohammad Bazar, a more rural area.

Conclusion

A nutrition transition to higher risk of overweight is evident in this rural setting in India, especially among women and individuals with high socioeconomic status. At the same time, a high prevalence of underweight persists, resulting in a significant double burden. Culturally sensitive interventions that address both ends of the malnutrition spectrum should be prioritised.
Neonatal intensive care nurses’ knowledge and beliefs regarding kangaroo care in China: a national survey
Authors: Zhang Yao , Deng Qingqi , Zhu Binghua , Li Qiufang , Wang Fang , Wang Hua , Xu Xinfen , Johnston Linda
Published: August 2018

Objective

Kangaroo care (KC), a well-established parent-based intervention in neonatal intensive care units (NICUs), with documented benefits for infants and their parents. However, in China there remains a lack of knowledge and a reluctance to implement KC in hospitals. Therefore, our aim was to investigate the current knowledge, beliefs and practices regarding KC among NICU nurses in China using the ‘Kangaroo Care Questionnaire’.

Methods

A quantitative descriptive survey was designed. This questionnaire comprised 90 items classified according to four domains: knowledge, practice, barriers and perception. Data were analysed using SPSS V.20.0, and content analysis was used to summarise data derived from open-ended questions.

Results

The survey involved 861 neonatal nurses from maternity and general hospitals across China (response rate=95.7%). The findings showed that 47.7% (n=411) of the nurses had participated in the implementation of KC. Neonatal nurses in the ‘experienced in KC’ group showed an overall better understanding of KC and its benefits with a higher ‘correct response’ rate than those in the ‘not experienced in KC’ group. In the ‘experienced in KC’ group, over 90% considered KC beneficial to the parent-baby relationship and attachment, and over 80% believed that KC positively affected outcomes of preterm infants. The ‘not experienced in KC’ group perceived more barriers to KC implementation than did the ‘experienced in KC’ group.

Conclusion

Although most nurses working in NICUs in China were aware of the benefits of KC, there remain substantial barriers to its routine use in practice. Education for both staff and parents is necessary, as is the provision of appropriate facilities and policies to support parents in providing this evidence-based intervention.
Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART): a multiarm phase IIb randomised, double-blind, placebo-controlled clinical trial comparing the efficacy of three neuroprotective drugs in secondary progressive multiple sclerosis
Authors: Connick Peter , De Angelis Floriana , Parker Richard A , Plantone Domenico , Doshi Anisha , John Nevin , Stutters Jonathan , MacManus David , Prados Carrasco Ferran , Barkhof Frederik , Ourselin Sebastien , Braisher Marie , Ross Moira , Cranswick Gina , Pavitt Sue H , Giovannoni Gavin , Gandini Wheeler-Kingshott Claudia Angela , Hawkins Clive , Sharrack Basil , Bastow Roger , Weir Christopher J , Stallard Nigel , Chandran Siddharthan , Chataway Jeremy
Published: August 2018

Introduction

The major unmet need in multiple sclerosis (MS) is for neuroprotective therapies that can slow (or ideally stop) the rate of disease progression. The UK MS Society Clinical Trials Network (CTN) was initiated in 2007 with the purpose of developing a national, efficient, multiarm trial of repurposed drugs. Key underpinning work was commissioned by the CTN to inform the design, outcome selection and drug choice including animal models and a systematic review. This identified seven leading oral agents for repurposing as neuroprotective therapies in secondary progressive MS (SPMS). The purpose of the Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART) will be to evaluate the neuroprotective efficacy of three of these drugs, selected with distinct mechanistic actions and previous evidence of likely efficacy, against a common placebo arm. The interventions chosen were: amiloride (acid-sensing ion channel antagonist); fluoxetine (selective serotonin reuptake inhibitor) and riluzole (glutamate antagonist).

Methods and analysis

Patients with progressing SPMS will be randomised 1:1:1:1 to amiloride, fluoxetine, riluzole or matched placebo and followed for 96 weeks. The primary outcome will be the percentage brain volume change (PBVC) between baseline and 96 weeks, derived from structural MR brain imaging data using the Structural Image Evaluation, using Normalisation, of Atrophy method. With a sample size of 90 per arm, this will give 90% power to detect a 40% reduction in PBVC in any active arm compared with placebo and 80% power to detect a 35% reduction (analysing by analysis of covariance and with adjustment for multiple comparisons of three 1.67% two-sided tests), giving a 5% overall two-sided significance level. MS-SMART is not powered to detect differences between the three active treatment arms. Allowing for a 20% dropout rate, 110 patients per arm will be randomised. The study will take place at Neuroscience centres in England and Scotland.

Ethics and dissemination

MS-SMART was approved by the Scotland A Research Ethics Committee on 13 January 2013 (REC reference: 13/SS/0007). Results of the study will be submitted for publication in a peer-reviewed journal.

Trial registration numbers

NCT01910259; 2012-005394-31;ISRCTN28440672.
What are the factors that contribute to the development of sexual dysfunction in breastfeeding women? A systematic scoping review protocol
Authors: Fuentealba-Torres Miguel , Cartagena-Ramos Denisse , Sierra Juan Carlos , Lara Lúcia Alves , Okano Sérgio Pires , Berra Thaís Zamboni , Alves Luana Seles , Leite Ana Carolina Andrade Biaggi , Yamamura Mellina , Silva Isília Aparecida , Nascimento Lucila Castanheira , Arcêncio Ricardo Alexandre
Published: August 2018

Introduction

Female sexual dysfunction is a public health problem. Evidence suggests that the population of nursing women is more vulnerable to the phenomenon due to breast feeding. Thus, this protocol was developed to explore the factors that contribute to the development of sexual dysfunction in breastfeeding women.

Methods and analysis

The systematic scoping review will be conducted in six stages, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols. The databases used will be: PubMed, Excerpta Medica Database, Cumulative Index for Nursing and Allied Health Literature, PsycINFO, Science Direct, Web of Science and Google Scholar. The searches were made until 1 June 2018, and no retrospective time limit was used. For the organisation of the literature retrieved from the databases, the EndNote Basic manager will be used. The Cochrane model will be used for the data extraction. The analysis of the quantitative data will be carried out through descriptive statistics and the qualitative data will be submitted to thematic analysis. The methodological quality of the empirical studies will be evaluated using the Mixed Methods Appraisal Tool.

Ethics and dissemination

As it will be a review study, without human involvement, there will be no need for ethical approval. The results will be disseminated in a scientific journal, as well as in various media, such as: conferences, seminars, congresses or symposia.
Trends in gender and socioeconomic inequalities in mental health following the Great Recession and subsequent austerity policies: a repeat cross-sectional analysis of the Health Surveys for England
Authors: Thomson Rachel M , Niedzwiedz Claire L , Katikireddi Srinivasa Vittal
Published: August 2018

Objective

It is known that mental health deteriorated following the 2008 global financial crisis, and that subsequent UK austerity policies post-2010 disproportionately impacted women and those in deprived areas. We aimed to assess whether gender and socioeconomic inequalities in poor mental health have changed since the onset of austerity policies.

Design

Repeat cross-sectional analysis of survey data.

Setting

England.

Participants

Nationally and regionally representative samples of the working-age population (25–64 years) from the Health Survey for England (1991–2014).

Outcome measures

Population-level poor mental health was measured by General Health Questionnaire-12 (GHQ) caseness, stratified by gender and socioeconomic position (area-level deprivation and highest educational attainment).

Results

The prevalence of age-adjusted male GHQ caseness increased by 5.9% (95% CI 3.2% to 8.5%, p<0.001) from 2008 to 2009 in the immediate postrecession period, but recovered to prerecession levels after 2010. In women, there was little change in 2009 or 2010, but an increase of 3.0% (95% CI 1.0% to 5.1%, p=0.004) in 2012 compared with 2008 following the onset of austerity. Estimates were largely unchanged after further adjustment for socioeconomic position, employment status and household income as potential mediators. Relative socioeconomic inequalities in GHQ caseness narrowed from 2008 to 2010 immediately following the recession, with Relative Index of Inequality falling from 2.28 (95% CI 1.89 to 2.76, p<0.001) to 1.85 (95% CI 1.43 to 2.38, p<0.001), but returned to prerecession levels during austerity.

Conclusions

Gender inequalities in poor mental health narrowed following the Great Recession but widened during austerity, creating the widest gender gap since 1994. Socioeconomic inequalities in poor mental health narrowed immediately postrecession, but this trend may now be reversing. Austerity policies could contribute to widening mental health inequalities.
Health Canada’s use of expedited review pathways and therapeutic innovation, 1995–2016: cross-sectional analysis
Authors: Lexchin Joel
Published: August 2018

Objectives

This study examines the use of expedited approval pathways by Health Canada over the period 1995 to 2016 inclusive and the relationship between the use of these pathways and the therapeutic gain offered by new products.

Design

Cross-sectional study.

Data sources

Therapeutic Products Directorate, Biologics and Genetic Therapies Directorate, Notice of Compliance database, Notice of Compliance with conditions web site, Patented Medicine Prices Review Board, La revue Prescrire, WHO Anatomical Therapeutic Chemical classification system.

Primary and secondary outcomes

Percent of new drugs evaluated by Health Canada that went through an expedited pathway between 1995 and 2016 inclusive. Kappa values comparing the review status with assessments of therapeutic value for individual drugs.

Results

Of 623 drugs approved by Health Canada between 1995 and 2016, 438 (70.3%) drugs went through the standard pathway and 185 (29.7%) an expedited pathway. Therapeutic evaluations were available for 509 drugs. Health Canada used an expedited approval pathway for 159 of the 509 drugs, whereas only 55 were judged to be therapeutically innovative. Forty-two of the 55 therapeutically innovative drugs received an expedited review and 13 received a standard review. The Kappa value for the entire period for all 509 drugs was 0.276 (95% CI 0.194 to 0.359) indicating ‘fair’ agreement between Health Canada’s use of expedited pathways and independent evaluations of therapeutic innovation.

Conclusion

Health Canada’s use of expedited approvals was stable over the entire time period. It was unable to reliably predict which drugs will offer major therapeutic gains. The findings in this study should provoke a discussion about whether Health Canada should continue to use these pathways and if so how their use can be improved.