bluuebunny/crossref_metadata_2025 huggingface dataset:
Rest‐Activity Rhythms and Cognitive Decline in Older Men: The Osteoporotic Fractures in Men Sleep Study
Authors: Rogers‐Soeder Tara S. , Blackwell Terri , Yaffe Kristine , Ancoli‐Israel Sonia , Redline Susan , Cauley Jane A. , Ensrud Kristine E. , Paudel Misti , Barrett‐Connor Elizabeth , LeBlanc Erin , Stone Katie , Lane Nancy E. , Tranah Greg ,   for the Osteoporotic Fractures in Men Study Research Group
Published: August 2018

Objective

To examine rest–activity circadian rhythm (RAR) and cognitive decline in older men.

Design

Longitudinal.

Setting

Osteoporotic Fractures in Men (MrOS) and ancillary Outcomes of Sleep Disorders in Men (MrOS Sleep) studies.

Participants

MrOS and MrOS Sleep participants (N=2,754; mean age 76.0 ± 5.3).

Measurements

The Modified Mini‐Mental State examination (3MS) was used to assess cognition at baseline (2003–05) and follow‐up examinations (2005–06 and 2007–09). Wrist actigraphy was used to measure 24‐hour activity counts at baseline. RAR variables included amplitude (strength of activity rhythm), mesor (mean activity level), pseudo F‐statistic (overall circadian rhythm robustness), and acrophase (time of daily peak activity).

Results

After an average of 3.4 ± 0.5 years, men with lower amplitudes, mesors, and pseudo F‐statistics had greater decline in 3MS performance (amplitude: –0.7 points Q1 vs –0.5 points Q4, p<.001; mesor: –0.5 points Q1 vs –0.2 points Q4, p=.01; pseudo F‐statistic: –0.5 points Q1 vs –0.3 points Q4, p<.001). Lower amplitudes and pseudo‐F statistics were associated with greater odds of clinically significant cognitive decline (≥5‐point decrease) (amplitude Q1 vs. Q4: odds ratio (OR)=1.4, 95% confidence interval (CI)=1.0–1.9; pseudo‐F statistic Q1 vs Q4: OR=1.4, 95% CI=1.0–1.9). Men with phase‐advanced acrophase had greater odds of clinically significant cognitive decline (OR=1.8, 95% CI=1.2–2.8). Results were adjusted for multiple confounders.

Conclusion

Several parameters of disrupted RAR (lower amplitude, pseudo F‐statistic, mesor, phase‐advanced acrophase) were associated with greater cognitive decline in older community‐dwelling men. These findings contribute to a growing body of evidence suggesting that altered RARs are associated with cognitive decline in older adults. J Am Geriatr Soc 66:2136–2143, 2018.
Antifungal and cytotoxicity activities of Banisteriopsis argyrophylla leaves
Authors: Oliveira Daiane M , Silva Tomás F R , Martins Mário M , de Morais Sérgio A L , Chang Roberto , de Aquino Francisco J T , da Silva Claudio V , Teixeira Thaise L , Martins Carlos H G , Moraes Thaís S , Cunha Luís C S , Pivatto Marcos , de Oliveira Alberto
Published: August 2018

Objectives

This work aimed to evaluate the antifungal and cytotoxic activity of the EtOH extract and fractions of Banisteriopsis argyrophylla leaves, and to perform the identification of these bioactive metabolites.

Methods

The EtOAc fraction (EAF) obtained from the ethanolic extract of B. argyrophylla leaves showed better antifungal potential against Candida spp. In this fraction, ten flavonoids have been identified by UHPLC-ESI-MSn. Then, EAF was submitted to column chromatography to give four new fractions (A1–A4). The cytotoxicity was determined against Vero cells.

Key findings

The EAF showed better antifungal potential against Candida spp. with minimum inhibitory concentrations (MICs) between 31.25 and 93.75 μg/ml. The (–)-catechin (fraction A1) showed a MIC of 2.83 μg/ml against Candida glabrata. Fractions A2, A3 and A4 were rich in quercetins and kaempferols and showed good inhibitory concentrations (5.86–46.87 μg/ml) against C. albicans, C. glabrata and C. tropicalis.

Conclusions

The EtOH extract, fractions and the isolated (–)-catechin showed lower toxicity to Vero cells than cisplatin, used as a positive control. Thus, the leaves of B. argyrophylla are a promising source of antifungal agents.
Sudden infant death and social justice: A syndemics approach
Authors: Bartick Melissa , Tomori Cecília
Published: August 2018

Sudden unexpected infant death (SUID) and sudden infant death syndrome (SIDS) prevention has focused on modifying individual behavioural risk factors, especially bedsharing. Yet these deaths are most common among poor and marginalized people in wealthy countries, including U.S. Blacks, American Indians/Alaskan Natives, New Zealand Māori, Australian Aborigines, indigenous Canadians, and low‐income British people. The United States now has the world's highest prevalence of SUID/SIDS, where even Whites' SIDS prevalence now approaches that of the Māori. Using public databases and the literature, we examine SUID/SIDS prevalence and the following risk factors in selected world populations: maternal smoking, preterm birth, alcohol use, poor prenatal care, sleep position, bedsharing, and formula feeding. Our findings suggest that risk factors cluster in high‐prevalence populations, many are linked to poverty and discrimination and have independent effects on perinatal outcomes. Moreover, populations with the world's lowest rates of SUID/SIDS have low income‐inequality or high relative wealth, yet have high to moderate rates of bedsharing. Employing syndemics theory, we suggest that disproportionately high prevalence of SUID/SIDS is primarily the result of socially driven, co‐occurring epidemics that may act synergistically to amplify risk. SUID must be examined through the lens of structural inequity and the legacy of historical trauma. Emphasis on bedsharing may divert attention from risk reduction from structural interventions, breastfeeding, prenatal care, and tobacco cessation. Medical organizations play an important role in advocating for policies that address the root causes of infant mortality via poverty and discrimination interventions, tobacco control, and culturally appropriate support to families.
Phosphagen kinase function in flagellated spores of the oomycete Phytophthora infestans integrates transcriptional regulation, metabolic dynamics and protein retargeting
Authors: Kagda Meenakshi S. , Vu Andrea L. , Ah‐Fong Audrey M. V. , Judelson Howard S.
Published: August 2018

Flagellated spores play important roles in the infection of plants and animals by many eukaryotic microbes. The oomycete Phytophthora infestans, which causes potato blight, expresses two phosphagen kinases (PKs). These enzymes store energy in taurocyamine, and are hypothesized to resolve spatial and temporal imbalances between rates of ATP creation and use in zoospores. A dimeric PK is found at low levels in vegetative mycelia, but high levels in ungerminated sporangia and zoospores. In contrast, a monomeric PK protein is at similar levels in all tissues, although is transcribed primarily in mycelia. Subcellular localization studies indicate that the monomeric PK is mitochondrial. In contrast, the dimeric PK is cytoplasmic in mycelia and sporangia but is retargeted to flagellar axonemes during zoosporogenesis. This supports a model in which PKs shuttle energy from mitochondria to and through flagella. Metabolite analysis indicates that deployment of the flagellar PK is coordinated with a large increase in taurocyamine, synthesized by sporulation‐induced enzymes that were lost during the evolution of zoospore‐lacking oomycetes. Thus, PK function is enabled by coordination of the transcriptional, metabolic and protein targeting machinery during the life cycle. Since plants lack PKs, the enzymes may be useful targets for inhibitors of oomycete plant pathogens.
Fluconazole‐induced actin cytoskeleton remodeling requires phosphatidylinositol 3‐phosphate 5‐kinase in the pathogenic yeast Candida glabrata
Authors: Bhakt Priyanka , Shivarathri Raju , Choudhary Deepak Kumar , Borah Sapan , Kaur Rupinder
Published: August 2018

Known azole antifungal resistance mechanisms include mitochondrial dysfunction and overexpression of the sterol biosynthetic target enzyme and multidrug efflux pumps. Here, we identify, through a genetic screen, the vacuolar membrane‐resident phosphatidylinositol 3‐phosphate 5‐kinase (CgFab1) to be a novel determinant of azole tolerance. We demonstrate for the first time that fluconazole promotes actin cytoskeleton reorganization in the emerging, inherently less azole‐susceptible fungal pathogen Candida glabrata, and genetic or chemical perturbation of actin structures results in intracellular sterol accumulation and azole susceptibility. Further, CgFAB1 disruption impaired vacuole homeostasis and actin organization, and the F‐actin‐stabilizing compound jasplakinolide rescued azole toxicity in cytoskeleton defective‐mutants including the Cgfab1Δ mutant. In vitro assays revealed that the actin depolymerization factor CgCof1 binds to multiple lipids including phosphatidylinositol 3,5‐bisphosphate. Consistently, CgCof1 distribution along with the actin filament‐capping protein CgCap2 was altered upon both CgFAB1 disruption and fluconazole exposure. Altogether, these data implicate CgFab1 in azole tolerance through actin network remodeling. Finally, we also show that actin polymerization inhibition rendered fluconazole fully and partially fungicidal in azole‐susceptible and azole‐resistant C. glabrata clinical isolates, respectively, thereby, underscoring the role of fluconazole‐effectuated actin remodeling in azole resistance.
Acetyl‐coenzyme A synthetase gene ChAcs1 is essential for lipid metabolism, carbon utilization and virulence of the hemibiotrophic fungus Colletotrichum higginsianum
Authors: Gu Qiongnan , Yuan Qinfeng , Zhao Dian , Huang Junbin , Hsiang Tom , Wei Yangdou , Zheng Lu
Published: August 2018

Acetyl‐coenzyme A (acetyl‐CoA) is a key molecule that participates in many biochemical reactions in amino acid, protein, carbohydrate and lipid metabolism. Here, we genetically dissected the distinct roles of two acetyl‐CoA synthetase genes, ChAcs1 and ChAcs2, in the regulation of fermentation, lipid metabolism and virulence of the hemibiotrophic fungus Colletotrichum higginsianum. ChAcs1 and ChAcs2 are both highly expressed during appressorial development and the formation of primary hyphae, and are constitutively expressed in the cytoplasm throughout development. We found that C. higginsianum strains without ChAcs1 were non‐viable in the presence of most non‐fermentable carbon sources, including acetate, ethanol and acetaldehyde. Deletion of ChAcs1 also led to a decrease in lipid content of mycelia and delayed lipid mobilization in conidia to developing appressoria, which suggested that ChAcs1 contributes to lipid metabolism in C. higginsianum. Furthermore, a ChAcs1 deletion mutant was defective in the switch to invasive growth, which may have been directly responsible for its reduced virulence. Transcriptomic analysis and quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR) revealed that ChAcs1 can affect the expression of genes involved in virulence and carbon metabolism, and that plant defence genes are up‐regulated, all demonstrated during infection by a ChAcs1 deletion mutant. In contrast, deletion of ChAcs2 only conferred a slight delay in lipid mobilization, although it was highly expressed in infection stages. Our studies provide evidence for ChAcs1 as a key regulator governing lipid metabolism, carbon source utilization and virulence of this hemibiotrophic fungus.
An evaluation of alternative explanations for widespread cytonuclear discordance in annual sunflowers (Helianthus)
Authors: Lee‐Yaw Julie A. , Grassa Christopher J. , Joly Simon , Andrew Rose L. , Rieseberg Loren H.
Published: August 2018

Cytonuclear discordance is commonly observed in phylogenetic studies, yet few studies have tested whether these patterns reflect incomplete lineage sorting or organellar introgression.

Here, we used whole‐chloroplast sequence data in combination with over 1000 nuclear single‐nucleotide polymorphisms to clarify the extent of cytonuclear discordance in wild annual sunflowers (Helianthus), and to test alternative explanations for such discordance.

Our phylogenetic analyses indicate that cytonuclear discordance is widespread within this group, both in terms of the relationships among species and among individuals within species. Simulations of chloroplast evolution show that incomplete lineage sorting cannot explain these patterns in most cases. Instead, most of the observed discordance is better explained by cytoplasmic introgression. Molecular tests of evolution further indicate that selection may have played a role in driving patterns of plastid variation – although additional experimental work is needed to fully evaluate the importance of selection on organellar variants in different parts of the geographic range.

Overall, this study represents one of the most comprehensive tests of the drivers of cytonuclear discordance and highlights the potential for gene flow to lead to extensive organellar introgression in hybridizing taxa.
Opportunities and limitations of reduced representation bisulfite sequencing in plant ecological epigenomics
Authors: Paun Ovidiu , Verhoeven Koen J. F. , Richards Christina L.
Published: August 2018

Contents

Summary
738

I.
Introduction
738

II.
RRBS loci as genome‐wide epigenetic markers
739

III.
Exploiting functional annotation of RRBS loci
739

IV.
Limitations of RRBS methods for nonmodel species
740

V.
Maximising the impact of RRBS in plants
741

VI.
Conclusions
741

Acknowledgements
741

Investigating the features and implications of epigenetic mechanisms across the breadth of organisms and ecosystems is important for understanding the ecological relevance of epigenetics. Several cost‐effective reduced representation bisulfite sequencing approaches (RRBS) have been recently developed and applied to different organisms that lack a well annotated reference genome. These new approaches improve the assessment of epigenetic diversity in ecological settings and may provide functional insights. We assess here the opportunities and limitations of RRBS in nonmodel plant species. Well thought out experimental designs that include complementary gene expression studies, and the improvement of genomics resources for the target group, promise to maximize the effect of future RRBS studies.
Pollen, ovules, and pollination in pea: Success, failure, and resilience in heat
Authors: Jiang Yunfei , Lahlali Rachid , Karunakaran Chithra , Warkentin Thomas D. , Davis Arthur R. , Bueckert Rosalind A.
Published: August 2018

Field pea (Pisum sativum), a major grain legume crop, is autogamous and adapted to temperate climates. The objectives of this study were to investigate effects of high temperature stress on stamen chemical composition, anther dehiscence, pollen viability, pollen interactions with pistil and ovules, and ovule growth and viability. Two cultivars (“CDC Golden” and “CDC Sage”) were exposed to 24/18°C (day/night) continually or to 35/18°C for 4 or 7 days. Heat stress altered stamen chemical composition, with lipid composition of “CDC Sage” being more stable compared with “CDC Golden.” Heat stress reduced pollen viability and the proportion of ovules that received a pollen tube. After 4 days at 35°C, pollen viability in flower buds decreased in “CDC Golden,” but not in “CDC Sage.” After 7 days, partial to full failure of anthers to dehisce resulted in subnormal pollen loads on stigmas. Although growth (ovule size) of fertilized ovules was stimulated by 35°C, heat stress tended to decrease ovule viability. Pollen appears susceptible to stress, but not many grains are needed for successful fertilization. Ovule fertilization and embryos are less susceptible to heat, but further research is warranted to link the exact degree of resilience to stress intensity.
On the Gender Gap in Financial Knowledge: Decomposing the Effects of Don't Know and Incorrect Responses*
Authors: Chen Zibei , Garand James C.
Published: August 2018

Objectives

Past studies have consistently shown that women have lower levels of financial knowledge than men, and hence there is a noticeable gender gap in financial knowledge. We reconsider the conventional measures of financial knowledge by disentangling don't know (DK) responses and incorrect answers and comparing the effect of these two disparate responses’ on the gender gap in financial knowledge.

Methods

Using data from the 2012 National Financial Capability Studies data set, we estimate a series of ordinary least squares regression and multinomial logit models of the gender gap in DK and incorrect responses.

Results

We find a strong gender gap in financial knowledge, but with a twist: (1) men are more likely to offer correct answers; (2) women are slightly more likely to offer incorrect answers; but (3) women are considerably more likely to provide DK responses. Hence women may exhibit lower levels of financial knowledge because they lose the opportunity to hazard a guess and arrive at a correct answer based either on partial knowledge or on random chance. We consider the possibility that there are psychological processes at work involving risk acceptance and confidence in financial knowledge that prompt women to give DK responses at a rate higher than men.

Conclusion

We suggest that future research should consider the relative roles of DK and incorrect responses in measuring financial knowledge.
Dynamic flexion/extension and non‐weight bearing ultrasonography is helpful for identifying manica flexoria tears in horses
Authors: Garcia da Fonseca Rita Martins , Evrard Laurence , Rabba Silvia , Salciccia Alexandra , Busoni Valeria
Published: August 2018

Lesions of the manica flexoria are a tenoscopic finding in horses with digital flexor tendon sheath tenosynovitis. This retrospective case series study describes the ultrasonographic findings in seven horses admitted for digital flexor tendon sheath swelling associated with lameness and tenoscopic confirmation of a manica flexoria tear. Six horses had a partial manica flexoria tear, one a complete rupture. The ultrasonographic examination included a static examination on the weight and non‐weight bearing limb and a dynamic limb assessment during flexion and extension. The main ultrasonographic finding at the static weight bearing examination in horses with a partial tear was an asymmetrical appearance of the manica flexoria at the level of the junction with the lateral border of the superficial digital flexor tendon, or an incomplete visualization of the manica flexoria in case of complete rupture. The split edges of the completed ruptured manica flexoria were seen floating in the synovial fluid at the examination in flexion. In six of seven cases, the superficial digital flexor tendon slid abnormally relative to the deep digital flexor tendon, during flexion/extension movements, with medial displacement of the superficial digital flexor tendon, appearance of an anechoic gap between the flexor tendons or reduced superficial digital flexor tendon sliding. Because ultrasonographic diagnosis of the manica flexoria tear is considered challenging, detection of these ultrasonographic features is helpful to increase the likelihood of identifying manica flexoria tears prior to tenoscopy. Authors recommend static ultrasonographic examination of the manica flexoria using a flexed limb position and dynamic ultrasonographic examination using flexion and extension positioning for horses with suspected digital sheath injury.
On the Role of the Plaque Porous Structure in Mussel Adhesion: Implications for Adhesion Control Using Bulk Patterning
Authors: Ghareeb Ahmed , Elbanna Ahmed
Published: August 2018

Mussel adhesion is a problem of great interest to scientists and engineers. Recent microscopic imaging suggests that the mussel material is porous with patterned void distributions. In this paper, we study the effect of the pore distribution on the interfacial-to-the overall response of an elastic porous plate, inspired from mussel plaque, glued to a rigid substrate by a cohesive interface. We show using a semi-analytical approach that the existence of pores in the vicinity of the crack reduces the driving force for crack growth and increases the effective ductility and fracture toughness of the system. We also demonstrate how the failure mode may switch between edge crack propagation and inner crack nucleation depending on the geometric characteristics of the bulk in the vicinity of the interface. Numerically, we investigate using the finite element method two different void patterns; uniform and graded. Each case is analyzed under displacement-controlled loading. We show that by changing the void size, gradation, or volume fraction, we may control the peak pulling force, maximum elongation at failure, as well as the total energy dissipated at complete separation. We discuss the implications of our results on design of bulk heterogeneities for enhanced interfacial behavior.
Effect of Cohesive Zone Size on Peeling of Heterogeneous Adhesive Tape
Authors: Avellar L. , Reese T. , Bhattacharya K. , Ravichandran G.
Published: August 2018

The interaction between the cohesive zone and the elastic stiffness heterogeneity in the peeling of an adhesive tape from a rigid substrate is examined experimentally and with finite element simulations. It is established in the literature that elastic stiffness heterogeneities can greatly enhance the force required to peel a tape without changing the properties of the interface. However, much of these concern brittle materials where the cohesive zone is limited in size. This paper reports the results of peeling experiments performed on pressure-sensitive adhesive tapes with both an elastic stiffness heterogeneity and a substantial cohesive zone. These experiments show muted enhancement in the peeling force and suggest that the cohesive zone acts to smooth out the effect of the discontinuity at the edge of the elastic stiffness heterogeneities, suppressing their effect on peel force enhancement. This mechanism is examined through numerical simulation which confirms that the peel force enhancement depends on the strength of the adhesive and the size of the cohesive zone.
Effects of Flow Coefficient on Miniature Centrifugal Pump Performance
Authors: Liu Guiqin , Chan Weng Kong
Published: August 2018

In order to help the design of miniature centrifugal pumps, the design method for macrosize centrifugal pumps is reviewed and the critical parameter, the flow coefficient, is examined in this paper for the miniature centrifugal pumps. The performance of the pumps designed is analyzed theoretically, numerically, and experimentally. Both numerical and theoretical results show that the value of the optimized flow coefficient is approximately 1.47. This value is about five times larger than the recommended value using conventional design technique for macrosize pumps. The optimum radius ratio obtained numerically is approximately 0.4. It can be concluded that the design approach for macrosize pumps is not applicable for pumps in the scale of decimeters. The results obtained in the present study provide us guidelines on the design and performance study of the miniature centrifugal pump.
Predicting the Colebrook–White Friction Factor in the Pipe Flow by New Explicit Correlations
Authors: Azizi Navid , Homayoon Reza , Hojjati Mahmoud Reza
Published: August 2018

Determination of friction factor (f) in pipe flow is necessary for various applications dealing with fluid flow. The Colebrook–White equation is the most accepted technique for the f-values estimation in turbulent flow. The biggest problem with this equation is that it can only be solved using numerical iteration methods. This paper contributes two new formulas based on the Colebrook–White equation to calculate f for the turbulent flow regime. To determine the new correlations, several equations were first suggested and then their coefficients were determined using the curve fitting method. Thereafter, based on various statistical error calculations, two equations with the highest accuracies were selected for the further modification. The advantages of the proposed correlations are that they are explicit in f so they do not need any iteration to compute friction factor and the results of calculating f-values reveal that the two new equations are of maximum absolute percent errors (APE) of 0.91% and 3.49% over the entire applicability range of Colebrook–White equation.
Neimark-Sacker Bifurcations Near Degenerate Grazing Point in a Two Degree-of-Freedom Impact Oscillator
Authors: Yin Shan , Ji Jinchen , Deng Shuning , Wen Guilin
Published: August 2018

Saddle-node or period-doubling bifurcations of the near-grazing impact periodic motions have been extensively studied in the impact oscillators, but the near-grazing Neimark-Sacker bifurcations have not been discussed yet. For the first time, this paper uncovers the novel dynamic behavior of Neimark-Sacker bifurcations, which can appear in a small neighborhood of the degenerate grazing point in a two degree-of-freedom impact oscillator. The higher order discontinuity mapping technique is used to determine the degenerate grazing point. Then, shooting method is applied to obtain the one-parameter continuation of the elementary impact periodic motion near degenerate grazing point and the peculiar phenomena of Neimark-Sacker bifurcations are revealed consequently. A two-parameter continuation is presented to illustrate the relationship between the observed Neimark-Sacker bifurcations and degenerate grazing point. New features that differ from the reported situations in literature can be found. Finally, the observed Neimark-Sacker bifurcation is verified by checking the existence and stability conditions in line with the generic theory of Neimark-Sacker bifurcation. The unstable bifurcating quasi-periodic motion is numerically demonstrated on the Poincaré section.
A Generalized Structure-Dependent Semi-Explicit Method for Structural Dynamics
Authors: Li Jinze , Yu Kaiping , Li Xiangyang
Published: August 2018

In this paper, a novel generalized structure-dependent semi-explicit method is presented for solving dynamical problems. Some existing algorithms with the same displacement and velocity update formulas are included as the special cases, such as three Chang algorithms. In general, the proposed method is shown to be second-order accurate and unconditionally stable for linear elastic and stiffness softening systems. The comprehensive stability and accuracy analysis, including numerical dispersion, energy dissipation, and the overshoot behavior, are carried out in order to gain insight into the numerical characteristics of the proposed method. Some numerical examples are presented to show the suitable capability and efficiency of the proposed method by comparing with other existing algorithms, including three Chang algorithms and Newmark explicit method (NEM). The unconditional stability and second-order accuracy make the novel methods take a larger time-step, and the explicitness of displacement at each time-step succeeds in avoiding nonlinear iterations for solving nonlinear stiffness systems.
Analytical Elastic–Plastic Cutting Model for Predicting Grain Depth-of-Cut in Ultrafine Grinding of Silicon Wafer
Authors: Lin Bin , Zhou Ping , Wang Ziguang , Yan Ying , Kang Renke , Guo Dongming
Published: August 2018

Grain depth-of-cut, which is the predominant factor determining the surface morphology, grinding force, and subsurface damage, has a significant impact on the surface quality of the finished part made of hard and brittle materials. When the existing analytical models are used to predict the gain depth-of-cut in ultra-precision grinding process of silicon wafer, the results obtained become unreasonable due to an extremely shallow grain depth-of-cut, which is inconsistent with the theory of the contact mechanics. In this study, an improved model for analyzing the grain depth-of-cut in ultra-fine rotational grinding is proposed, in which the minimum grain depth-of-cut for chip formation, the equivalent grain cutting tip radius, elastic recovery deformation in cutting process, and the actual number of effective grains are considered in the prediction of the ultrafine rotational grinding of brittle materials. The improved model is validated experimentally and shows higher accuracy than the existing model. Furthermore, the sensitivity of the grain depth-of-cut to three introduced factors is analyzed, presenting the necessity of the consideration of these factors during the prediction of grain depth-of-cut in ultrafine grinding.
Effect of Electrode Configurations on the Performance of Electro-Hydrodynamic Micromixer
Authors: Kim Hak-Sun , Kim Hyun-Oh , Kim Youn-Jea
Published: August 2018

Micromixers are widely used in chemical engineering and bioengineering industries. In this study, geometrical effects of electrodes were investigated to mix fine particles affected by external electric field. In order to improve the particle mixing performance of micromixer, the electroosmosis effect could be utilized with configuration of electrodes at the top and bottom of microchannel. Numerical analysis was performed to derive the pattern of electrodes with superior mixing efficiency by changing voltages and zeta potentials applied to the micromixer channel, by using COMSOL Multiphysics 5.2. The results of mixing performance were graphically depicted with various arrangements of electrode and flow conditions.
Optimization of Wettability Gradient for Enhancement of Thermal Performance of Micro Heat Pipes
Authors: Singh Manjinder , Datla Naresh Varma , Bahga Supreet Singh , Kondaraju Sasidhar
Published: August 2018

Continuous increase in the integration density of microelectronic units necessitates the use of MHPs with enhanced thermal performance. Recently, the use of wettability gradients have been shown to enhance the heat transfer capacity of MHPs. In this paper, we present an optimization of axial wettability gradient to maximize the heat transfer capacity of the MHP. We use an experimentally validated mathematical model and interior point method to optimize the wettability gradient. For our analysis, we consider two cases wherein (i) the mass of working fluid is constrained, (ii) mass of working fluid is a design variable. Compared to MHP with uniform high wettability and filled with a fixed mass of working fluid, optimization of the wettability gradient leads to 65% enhancement in heat transfer capacity. Similar comparisons for MHP filled with variable mass of working fluid shows more than 90% increase in the maximum heat transfer capacity due to optimization of wettability gradient.
The Importance of Viscous Dissipation in Micro-Tube and Micro-Gap Flows
Authors: Haustein Herman D. , Kashi Barak
Published: August 2018

Increasing heat flux density of modern micro-electronic devices has promoted a transition to liquid-based forced convection cooling. The miniaturization and maldistribution of micro-electronic heat generating elements (e.g. transistors and laser diodes) has promoted a similar decrease in size of cooling flow elements, specifically, micro-channels, micro-gaps and micro-jets. Convection heat transfer scaling laws do not contain a scale-factor in dimensionless form, and heat transfer coefficient (HTC) should continually increase with a decrease in size, as h∝1/d. However, extremely high HTCs are not found at tens of microns, which can be explained by the emergence of a typically neglected effect — heating by viscous dissipation. Traditionally, dissipation is only associated with high-Mach gas flows or high-viscosity oil flows. Nonetheless, it reemerges in micro-cooling, as shown here through theoretical analysis of simple cases. The extreme near-wall gradients and high L/d ratios, of these flows reintroduce dissipation as significant. When flow diameters reach a critical size, on the scale of tens of microns at Re = 2,000, depending on flow configuration, rate and liquid properties, the energy generated by dissipation is sufficient to counteract the inherent increase of HTC and the trend reverses. This maximum in HTC is the absolute lower limit to the cooling element size, a matter which has not been properly addressed. The present study lays a framework of recommendations and limitations for future cooling studies, thereby curbing the ongoing trend of flow miniaturization.
Influence of Condensation on the Outer Surface of Polymer Hollow Fiber Heat Exchangers During Heat Transfer
Authors: Brozova Tereza , Bartuli Erik
Published: August 2018

Condensation during heat transfer processes can be very beneficially used due to the large amount of energy contained in phase change (vapor to liquid). This contribution focuses on the possible use of polymer hollow fiber heat exchangers (PHFHEs) in air conditioning. PHFHEs consist of hundreds or thousands of polymer hollow fibers with an outer diameter of around 1 mm. The wall thickness is approximately 10% of the outer diameter. PHFHEs are heat exchangers with such benefits as low weight, easy shaping, corrosion resistance, and resistance to many chemical solutions. In comparison with metal heat exchangers (made of copper, aluminum, or stainless steel) the plastic wall of PHFHEs has low thermal conductivity (between 0.1 and 0.4 Wm-1K-1). This seems to be their key disadvantage. However, due to the extremely small thickness of the fiber’s wall this disadvantage is negligible. PHFHEs are compact heat exchangers with a large heat transfer area with respect to their volume.

This paper shows the results of condensation tests for PHFHEs that consist of 6 equivalent layers of polypropylene fibers with a length of 190 mm. The total number of fibers is 798. The air humidity was set to 50% with an air temperature of 27°C, which are the typical conditions for such tests in air conditioning technology. Another important parameter was the velocity of the air. Testing velocities were chosen as 3 m s−1 and 1 m s−1.

The influence of gravity was studied by putting the PHFHEs in three different positions. The fibers were placed in horizontal and vertical positions, and in a position where fibers form an angle of 45° with the ground.

The study showed the ineffectiveness of placing the PHFHE in a horizontal position and suggests that it is better to have a larger distance between the layers of fibers.
Flow Regime Detection of Boiling Flow in Microchannels Using Electrical Sensing Elements Validated by Videography
Authors: Talebi Mohammadmahdi , Cobry Keith , Sadir Sahba , Dittmeyer Roland , Woias Peter
Published: August 2018

In this work we present a method that provides the possibility to analyze directly the electrical properties of two-phase flow in microchannel boiling systems. It is shown that the use of impedimetric sensing techniques can be used to track two-phase boiling flow. In order to perform such measurements, the electrical impedance of the composite medium in the channel is measured using planar capacitive elements that are implemented over the channel on a glass lid. Working electrodes are fabricated using indium tin oxide on glass and are compressed against a precision machined metal microchannel. Therefore, it is possible to visually analyze two-phase flow inside the microchannel while simultaneously performing electrical impedance measurements. In order to prevent electrochemical reactions between the fluid inside the microchannel and electrodes on the glass lid, a thin layer of SU8 photoresist was deposited as a protective layer. The electrical impedance measurements were characterized over two-phase flow regimes including bubbly flow, slug flow and annular flow via comparison with simultaneous video recordings.
Severing enzymes amplify microtubule arrays through lattice GTP-tubulin incorporation
Authors: Vemu Annapurna , Szczesna Ewa , Zehr Elena A. , Spector Jeffrey O. , Grigorieff Nikolaus , Deaconescu Alexandra M. , Roll-Mecak Antonina
Published: August 2018

Severing to build microtubules

Microtubules are essential intracellular polymers, built from tubulin subunits, that establish cell shape, move organelles, and segregate chromosomes during cell division. Vemu
et al.
show that microtubule-severing enzymes extract tubulin subunits along the microtubule shaft. This nanoscale damage is repaired by the incorporation of free tubulin, which stabilizes the microtubule against depolymerization. When extraction outpaces repair, microtubules are severed, emerging with stabilized ends composed of fresh tubulin. The severed microtubules act as templates for new microtubule growth, leading to amplification of microtubule number and mass. Thus, seemingly paradoxically, severing enzymes can increase microtubule mass in processes such as neurogenesis and mitotic spindle assembly.

Science
, this issue p.
eaau1504
‘Better to save one life than build a seven-storied pagoda’: a qualitative study of health education for patients with acute coronary syndrome and type 2 diabetes mellitus in Shanghai, China
Authors: Liu Xian-Liang , Willis Karen , Wu Chiung-Jung (Jo) , Shi Yan , Johnson Maree
Published: August 2018

Objective

To describe, from the perspectives of health professionals, the health education currently being provided from hospital admission to discharge to home to patients who present with acute coronary syndrome who also have type 2 diabetes mellitus (T2DM).

Methods

A qualitative study using semistructured interviews was undertaken in the coronary care unit (CCU) of a major hospital in Shanghai, China. Fifteen health professionals (nine registered nurses and six physicians) from the CCU who delivered health education to patients with acute coronary syndrome and T2DM participated. Participants also completed an Education Content Checklist containing topics consistent with existing national guidelines.

Findings

Major themes identified included: health education is an essential embedded component of treatment; health education comprises varied strategies to facilitate behavioural change; and barriers and required resources to deliver effective health education.

Conclusions

Surviving the initial symptoms and providing immediate treatment is the first step in recovery for patients with acute coronary syndrome and T2DM. Health education is an essential component of the management of these patients, and content and focus that is responsive to the recovery stage of the patient is required. Teaching and supporting strategies appropriate for the inpatient phase prior to discharging to the community phase are required.
Education level and health-related quality of life after oesophageal cancer surgery: a nationwide cohort study
Authors: Schandl Anna Regina , Johar Asif , Mälberg Kalle , Lagergren Pernilla
Published: August 2018

Objective

The purpose of the study was to investigate whether low education level was associated with patients’ health-related quality of life (HRQOL) after oesophageal cancer resection.

Setting

A nationwide cohort study in Sweden.

Participants

In total, 378 patients who underwent oesophageal cancer surgery in 2001–2005 were followed up 6 months and 3 years after surgery.

Outcome measures

HRQOL was assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (QLQ-C30) and the oesophageal cancer-specific module. The association between level of education and HRQOL was calculated with linear regression models, providing mean score differences (MD) and 95% CIs. Data were analysed separately for women and men.

Results

Education level was not associated with HRQOL recovery after oesophageal cancer surgery. However, when data were stratified by sex, lower education was associated with worse emotional function (MD −13; 95% CI −22 to −3), more symptoms of insomnia (MD 20; 95% CI 8 to 32) and reflux (MD: 15; 95% CI 3 to 26) for women, but not for men. Among women, low education was in general associated with worse functioning and more symptoms.

Conclusions

Low education was not associated with worse HRQOL after oesophageal cancer surgery. However, when data were stratified for sex, low education level was associated with worse functioning and more symptoms in certain HRQOL domains for women, particularly in a short-term perspective. For men, no such association was found.
Links between blood pressure and medication intake, well-being, stress, physical activity and symptoms reported via a mobile phone-based self-management support system: a cohort study in primary care
Authors: Taft Charles , Hallberg Inger , Bengtsson Ulrika , Manhem Karin , Kjellgren Karin
Published: August 2018

Objectives

To explore relationships between patients’ self-monitoring of blood pressure (BP) and their concurrent self-reports of medication intake, well-being, stress, physical activity and symptoms.

Design

This study is a secondary analysis of a prospective study exploring the 8-week effectiveness of a mobile phone-based self-management support system for patients with hypertension.

Setting

Four primary healthcare centres situated in urban and suburban communities in Sweden.

Participants

50 patients undergoing treatment for hypertension.

Primary and secondary outcome measures

Associations between systolic (SBP) and diastolic blood pressure (DBP) and 10 self-report lifestyle-related variables were analysed using linear mixed effects modelling.

Results

Medication intake, better well-being, less stress and greater physical activity were associated variously with lower same-day SBP and DBP. The single strongest association was found between medication intake and SBP, where failure to take medications was associated with an estimated 7.44 mm Hg higher SBP. To a lesser degree, medication intake was also associated with DBP, where DBP was 4.70 mm Hg higher in cases where medications were not taken. Well-being and stress were consistently associated with SBP and DBP, whereas physical activity was associated with only SBP. None of the symptoms—dizziness, headache, restlessness, fatigue or palpitations—were significantly associated with BP.

Conclusions

Our findings that BP was associated with patients’ BP management behaviours and experiences of well-being and stress, but not symptoms suggest that enabling persons with hypertension to monitor and track their BP in relation to medication intake, physical activity, well-being, stress and symptoms may be a fruitful way to help them gain first-hand understanding of the importance of adherence and persistence to treatment recommendations.

Trial registration number

NCT01510301; Pre-results.
Risk of cardiac and non-cardiac adverse events in community-dwelling older patients with atrial fibrillation: a prospective cohort study in the Netherlands
Authors: van Doorn Sander , Tavenier Annerien , Rutten Frans H , Hoes Arno W , Moons Karel G M , Geersing Geert-Jan
Published: August 2018

Objectives

Patients with atrial fibrillation (AF) are at increased risk of many adverse events, notably stroke. To prevent all adverse outcomes, integrated AF care is advocated though the potential domain for such multidisciplinary management is still unclear. Therefore, insight in the systemic nature of AF and identifying patients at risk of adverse events after oral anticoagulation is needed. The aim of this study is to first describe the risk of hospitalisation and mortality in community-dwelling older patients with AF using anticoagulants, and second to assess the association between traditional cardiac risk factors and these outcomes.

Design

A prospective cohort.

Setting

General practice.

Participants

2068 patients with AF using oral anticoagulants.

Outcome measures

We calculated incidence rates (IRs) of ischaemic stroke, bleeding, hospitalisations and mortality, and compared risk factors using Cox regression between those with and without an adverse event, both for cardiac and non-cardiac causes.

Results

During a median follow-up of 2.7 (IQR 2.2–3.0) years, the IR per 100 person-years was 22.1 for hospitalisations and 6.7 for mortality. Non-cardiac events outnumbered cardiac events (IRs 15.7 vs 7.6 per 100 person-years for hospitalisation, p<0.001 and 5.0 vs 1.7, p<0.001 for mortality). As a comparison, the IRs for stroke and major bleeding were 1.7 and 0.8 per 100 person years, respectively. In multivariate models, high age, heart failure and vascular disease were independently associated with all-cause hospitalisation and— in addition to diabetes, previous stroke and renal disease—for all-cause mortality.

Conclusions

In anticoagulated community-dwelling patients with AF, stroke risk is effectively reduced and thus fairly low, whereas risks of hospitalisation and mortality remain high, importantly mainly for non-cardiac causes. Notably high age, heart failure and vascular disease are predictive for such outcomes and may be of value in identifying high-risk patients in the future.

Trial registration number

NTR3741.
Trends in gambling participation and gambling severity among Finnish men and women: cross-sectional population surveys in 2007, 2010 and 2015
Authors: Castrén Sari , Heiskanen Maria , Salonen Anne H
Published: August 2018

Objective

The aim of this study is to evaluate trends in past-year gambling participation and gambling severity among Finnish men and women from 2007 to 2015.

Design

Cross-sectional population surveys from years 2007, 2011 and 2015.

Setting

Data were drawn from the population register and collected using computer-assisted telephone interviews.

Participants

Representative random samples of Finns aged 15–74 were drawn in the study in 2007 (n=5008), 2011 (n=4484) and 2015 (n=4515) with response rates of 58%, 40% and 62%, respectively.

Outcome measures

The outcome measures were gambling versatility, type of games, gambling intensity and gambling severity. Significance (p) between time points was determined using χ2tests. All temporal comparisons between 2007–2011, 2011–2015 and 2007–2015 were performed separately for all respondents aged 15–74 and for women and men.

Results

Gambling participation overall showed a rising trend (6.6 percentage points, 95% CI 4.9 to 8.3) from 2007 to 2015. In 2007–2011 women’s gambling participation increased more (7.8 percentage points, 95% CI 5.5 to 10.4) than men’s (5.4 percentage points, 95% CI 3.2 to 7.6). The most popular game types since 2007 have been lottery games, scratch cards and electronic gaming machines (EGMs). EGM gambling, on the other hand, has decreased since 2007. Online gambling has increased significantly from 2007 to 2015 in both genders. Men’s at-risk gambling decreased from 2007 to 2011, while women’s at-risk gambling and problem gambling increased from 2011 to 2015.

Conclusions

Women’s increasing gambling participation is causing gender differences in gambling behaviour to narrow. The article concludes with a discussion of the need for gender-specific interventions aimed at preventing gambling-related harm and ultimately at protecting the most vulnerable groups.