bluuebunny/crossref_metadata_2025 huggingface dataset:
Fault Detection and Isolation for Proton Exchange Membrane Fuel Cell Using Impedance Measurements and Multiphysics Modeling
Authors: Jullian G. , Cadet C. , Rosini S. , Gérard M. , Heiries V. , Bérenguer C.
Published: September 2020

This study proposes a fault detection and isolation tool for proton exchange membrane fuel cell (PEMFC) operating in embedded applications. A model‐based approach, taking partially into account degradation phenomena, is proposed in order to increase the robustness of the tool regarding transient operations and stack ageing. The considered faults are the abnormal operating conditions that can decrease the fuel cell lifetime. The fault detection approach is based on residual generation using both voltage and high frequency resistance measurements and thus combining the advantages of knowledge‐based model and electrochemical impedance spectroscopy (EIS) diagnosis approaches. To that end, a multi‐physics fuel cell model has been used. This model computes not only the stack voltage but also the high frequency resistance in dynamic conditions. Additionally, the model is modified to take into account the ageing of the fuel cell. Validation is carried out on experimental characterizations during 1,000 h ageing. The results on a new fuel cell stack show a score of 91% for fault isolation. However, without any adaptation, this score drops dramatically as the stack ages. Finally, thanks to ageing modeling and to the proposed adaptation of the detection/isolation procedure, the diagnosis performance remains reliable during fuel cell stack ageing.
Creating a Roadmap to Capture a Vision for a Sustainable Community in Transition; a Case Study in a Dutch town Best
Authors: Elvebakk Laura , Muller Gerrit
Published: September 2020

Best Duurzaam is a cooperation that aims to facilitate a transition to a sustainable living at a local level. However, it is missing an overall vision. Additionally, Best Duurzaam would like to have a closer collaboration with the local municipality.

Roadmapping is a planning tool used for framing a vision shared by project participants. It aids in communicating the dynamic relations between group's ideas and accessible resources. A roadmap makes a project approach more specific in both contents and time.

The goal of this study was to investigate how roadmapping could help in solving communication issues. Researchers used roadmapping to understand the issues, to explore solutions and to improve communication. The research was done at municipality level to study the tool's effectiveness in the context of local sustainability transition. The research result suggests that the roadmap is a valuable tool for communication and sharing ideas among stakeholders.
When to Constrain the Design? Application of Design Standards on a New Development Program
Authors: Katz Tami
Published: September 2020

Use of design and construction standards have many benefits when trying to meet expectations on product safety and quality ‐ they help ensure commonality and consistency of approaches to design, manufacturing, test and verification. However, the use of standards can drive cost and inhibit innovation for certain applications. This leads to the question of when is it appropriate to constrain the design and apply standards on a program? This paper looks at the typical usage of design and construction standards across three different industries to evaluate when their usage enables projects, and when they drive cost. This paper provides the conclusion that optimization of a project for cost, technical and schedule is best served when standards are limited to industries with common products in a highly regulated domain. Usage of standards is not a “one size fits all” approach, and alternate strategies exist for industries in cases where limiting the design solution could impact ability to realize cost effective, innovative designs.
How Systems Engineering and Systems Thinking Enable Innovation
Authors: Beasley Richard , Ingram Claire
Published: September 2020

There are many significant challenges facing the world, necessitating innovative and effective systems and products to enable a prosperous and sustainable future. However, successful delivery of innovative systems is very difficult. We argue that appropriate application of Systems Engineering and Systems Thinking plays a critical role in ensuring innovations have the best chance of success. Although many innovation methodologies exist, few incorporate the concepts or vocabulary of Systems Thinking in a structured way. This paper attempts to rectify this, by taking some basic innovation concepts and a simple structured approach to thinking about the system and its wider environment, and showing how they can be integrated in order to augment innovation processes with Systems Thinking concepts. Through applying Systems Engineering principles to the innovation context we identify innovation traps that may arise when failing to think about a system in its wider context, and we provide detailed case studies to illustrate our points.
MBSE Methodology Applied for a Technology Demonstrator in the Space Transportation Sector
Authors: Llano Mikel Iturbe , Quappen Gerrit
Published: September 2020

Over the last 40 years, NASA has sponsored many technology development programs for composite cryogenic tanks (CCT) in order to improve space launchers’ performance. However, they have learned certain lessons in terms of risk mitigation, design failures, lack of technology maturation and time constraints during development phases that push to reinforce the systems engineering perspective given the number of new functions, components and subsystems involved in these CCTs performance.

The present paper suggests a Model‐Based Systems Engineering (MBSE) methodology to reduce the challenges that CCTs entail in a technology demonstrator program currently in a conceptual phase for the Ariane 6 upper stage. Topics such as a strong operational analysis; project instability; a Fully Integrated Operational System (FIOS) model combined with a Manufacturing, Assembly, Integration & Test (MAIT) model; requirements traceability; and model navigability issues are studied throughout the modelling process. Results from this approach show and ease the way to obtain information in a complex and large model intended to simulate our System of Interest (SoI)/CCTs life cycle. Consequently, CCTs can face NASA's aforementioned lessons learned from an early phase of the project in order to prevent similar adverse situations.
Lower Cerebrovascular Reactivity Contributed to White Matter Hyperintensity‐Related Cognitive Impairment: A Resting‐State Functional MRI Study
Authors: Ni Ling , Zhang Bing , Yang Dan , Qin Ruomeng , Xu Hengheng , Ma Junyi , Shao Pengfei , Xu Yun
Published: September 2020

Background

Impaired cerebrovascular reactivity (CVR) plays an important role in the pathophysiology of white matter hyperintensities (WMHs). The pathogenesis of CVR in the development of WMH‐related cognitive impairment (CI) remains poorly understood.

Purpose

To detect the CVR status in WMH subjects with/without CI by using a resting‐state blood oxygenation level‐dependent (BOLD) approach and to explore the mediating relationships among CVR, WMH, and cognitive level.

Study Type

Prospective.

Subjects

Subjects with moderate to severe WMH (with CI [WMH‐CI], n = 68; without CI [WMH‐no‐CI, n = 63) as well as normal controls (NCs, n = 87).

Field Strength/Sequence

3.0T with gradient‐recalled echoplanar imaging and 3D fluid‐attenuated inversion recovery.

Assessment

The CVR, WMH volume, and cognitive level were assessed. The CVR map was derived using BOLD signal obtained from resting‐state functional MRI data.

Statistical Tests

CVR maps were compared among the three groups. Partial correlation analyses were performed to correlate impaired CVR with WMH volume and cognitive test scores. Mediation analysis was conducted to determine whether WMH acted as a mediating factor between CVR and cognitive function.

Results

Compared with the NC group, both WMH groups showed reduced CVR in the left hemisphere (P < 0.05). The WMH‐CI group showed further decreased CVR in the left frontal area, when compared with the WMH‐no‐CI group (P < 0.05). In the WMH‐CI group, the lower CVR in left frontal area was a strong indicator of poor performance on general cognition (r = 0.311), executive function (r = 0.362), and information processing speed (r = 0.399) (all P < 0.05). Periventricular WMH (PWMH) volume mediated these correlations, the β and 95% bootstrap confidence intervals were (0.5097, [0.1498,1.1385]), (−0.4081, [−1.0256,‐0.1363]), and (−0.5576, [−1.4666,‐0.1538]), respectively.

Data Conclusion

WMH‐CI subjects showed a greater reduction of CVR derived from a resting‐state BOLD approach in the left frontal area than WMH‐no‐CI subjects. Cognition was highly dependent on the integrity of cerebrovascular reactivity and mediated by PWMH burden.

Level of Evidence

4

Technical Efficacy

Stage 2
Quantitative Skeletal Muscle Imaging Using 3D MR Fingerprinting With Water and Fat Separation
Authors: Marty Benjamin , Lopez Kolkovsky Alfredo L. , Araujo Ericky C.A. , Reyngoudt Harmen
Published: September 2020

Background

Quantitative muscle MRI is a robust tool to monitor intramuscular fatty replacement and disease activity in patients with neuromuscular disorders (NMDs).

Purpose

To implement a 3D sequence for quantifying simultaneously fat fraction (FF) and water T1 (T1,H2O) in the skeletal muscle, evaluate regular undersampling in the partition‐encoding direction, and compare it to a recently proposed 2D MR fingerprinting sequence with water and fat separation (MRF T1‐FF).

Study Type

Prospective.

Phantom/Subjects

Seventeen‐vial phantom at different FF and T1,H2O, 11 healthy volunteers, and 6 subjects with different NMDs.

Field Strength/Sequence

3T/3D MRF T1‐FF, 2D MRF T1‐FF, STEAM MRS

ASSESSMENT

FF and T1,H2O measured with the 2D and 3D sequences were compared in the phantom and in vivo at different undersampling factors (US). Data were acquired in healthy subjects before and after plantar dorsiflexions and at rest in patients.

Statistical Tests

Linear correlations, Bland–Altman analysis, two‐way repeated measures analysis of variance (ANOVA), Student's t‐test.

Results

Up to a US factor of 3, the undersampled acquisitions were in good agreement with the fully sampled sequence (R2 ≥ 0.98, T1,H2O bias ≤10 msec, FF bias ≤4 × 10–4) both in phantom and in vivo. The 2D and 3D MRF T1‐FF sequences provided comparable T1,H2O and FF values (R2 ≥ 0.95, absolute T1,H2O bias ≤35 msec, and absolute FF bias ≤0.003). The plantar dorsiflexion induced a significant increase of T1,H2O in the tibialis anterior and extensor digitorum (relative increase of +10.8 ± 1.7% and + 7.7 ± 1.4%, respectively, P < 0.05), that was accompanied by a significant reduction of FF in the tibialis anterior (relative decrease of –16.3 ± 4.0%, P < 0.05). Some subjects with NMDs presented increased and heterogeneous T1,H2O and FF values throughout the leg.

Data Conclusion

Quantitative 3D T1,H2O and FF maps covering the entire leg were obtained within acquisition times compatible with clinical research (4 minutes 20 seconds) and a 1 × 1 × 5 mm3 spatial resolution.

Level of Evidence

2

Technical Efficacy

Stage 2
Leaving it on the table? An examination of unrealized bargaining power in multimarket buyer–supplier exchanges
Authors: Cheng Li , Craighead Christopher W. , Crook T. Russell , Eckerd Stephanie
Published: September 2020

The study of bargaining power and its role in negotiations has a long history in operations management research. Much of this research has involved buyer–supplier exchanges and has often hinged on the assumption that powerful firms negotiate to wield (fully) their power for favorable outcomes. Yet, it is unclear to what extent firms transform their potential power into realized power. Building on insights grounded in resource dependence theory and literature on competitive dynamics and organization design, we theorize that structural factors (i.e., decentralization, spheres of influence, and mutual dependence) constrain firms from fully realizing their potential power. In doing so, we center on a more nuanced context—multimarket buyer–supplier exchanges, wherein buyers and suppliers handle multiple exchanges across different product markets. We use two controlled negotiation experiments to test our hypotheses. Our results show that in multimarket exchanges, three key factors (and how they sometimes interact) constrain power use. These results offer boundary conditions to extant theory. Most profoundly, our results reveal that centralization (traditionally viewed as a structural lever to enhance power use) alone does not affect power use but has distinct effects conditional on other factors—countering theory and challenging best practices in industry.
Ultrasound‐Guided Breast Biopsies
Authors: Bhatt Asha A. , Whaley Dana H. , Lee Christine U.
Published: September 2020

Ultrasound‐guided breast biopsies can be challenging to perform, especially when the target is adjacent to the nipple, skin, or implant or when the target is small and in very posterior, dense fibroglandular tissue. Oftentimes, a slightly modified approach can result in a diagnostic biopsy specimen with minimal complications. After a brief review of basic techniques for ultrasound‐guided breast biopsies that includes a review of conventional breast biopsy devices, a presentation of procedural modifications and techniques to consider for more challenging cases is described. In particular, novel open‐trough and tandem‐needle techniques are detailed. Several cases using these techniques are then presented.
The anaerobic corrosion of candidate disposal canister materials in compacted bentonite exposed to natural granitic porewater containing native microbial populations
Authors: Reddy Bharti , Padovani Cristiano , Rance Andrew P. , Smart Nick R. , Cook Angus , Haynes Haydn M. , Milodowski Antoni E. , Field Lorraine P. , Kemp Simon J. , Martin Andrew , Diomidis Nikitas
Published: September 2020

The materials corrosion test (MaCoTe) is a long‐term, multinational in situ corrosion experiment setup at the Grimsel Test Site, Switzerland. The experiment has been operating since 2014 with a focus on the corrosion behaviour of container materials for the disposal of high‐level waste and spent nuclear fuel under conditions representing a granitic deep geological repository. The experiment consists of eight modules containing metal coupons and bentonite. Two of the modules, each with a different bentonite density, have been retrieved after 394 days of exposure and have been analysed using a range of techniques aimed at studying the corrosion behaviour of the metals and the mineralogical evolution of the bentonite. Weight loss measurements show that carbon steel had a relatively low average corrosion rate (~2 µm year−1). Much lower average corrosion rates were measured for the various types of copper (0.13–0.32 µm year−1). No detectable corrosion was measured on stainless steel coupons. To date, no significant differences were observed in the corrosion behaviour and rate of the test metals in bentonite with different dry densities.
Inborn Errors of Metabolism in Adults: Two Patients with Movement Disorders Caused by Glutaric Aciduria Type 1
Authors: Ulmanová Olga , Koens Lisette H. , Jahnová Helena , de Vries Jeroen J. , de Koning Tom J. , Růžička Evžen , Tijssen Marina A.J.
Published: September 2020

View Supplementary Video 1

View Supplementary Video 2
Acute Stereotypic Behavior: Expanding the Spectrum of Movement Disorders Attributed to Vitamin B12 Deficiency
Authors: Oppo Valentina , Melis Marta , Melis Maurizio , Cossu Giovanni
Published: September 2020

View Supplementary Video 1
CREBH: A Complex Array of Regulatory Mechanisms in Nutritional Signaling, Metabolic Inflammation, and Metabolic Disease
Authors: Wade Henry , Pan Kaichao , Su Qiaozhu
Published: September 2020

The endoplasmic reticulum (ER)‐resident basic leucine zipper (bZIP) transcription factor c‐AMP responsive element binding protein H (CREBH/CREB3L3) is exclusively expressed in the liver and intestine. Physiologically, CREBH is intrinsically linked to nutritional homeostasis via its regulation on fatty acid β‐oxidation, lipid droplet process, very low‐density lipoprotein metabolism, gluconeogenesis, and iron metabolism. Pathologically, CREBH enhances hepatic acute‐phase response gene expression (e.g., C‐reactive protein and serum amyloid P‐component) and mediates nutrient‐surplus induced metabolic inflammation. Hyperactivation of CREBH in metabolic inflammation further contributes to the development of hyperlipidemia, lipotoxicity, non‐alcoholic fatty liver disease, and potentially non‐alcoholic steatohepatitis. This review highlights recent findings that delineate the interactions between CREBH and peroxisome proliferator activated receptor α (PPARα), fibroblast growth factor 21 (FGF21), fat‐specific protein 27 (FSP27), and lipoprotein metabolism with a focus on the molecular and biochemical mechanisms that underlie the development of metabolic inflammation, non‐alcoholic fatty liver disease and inflammatory associated bone disease.
The effects of scaling and bends in a fiber‐optic modalmetric acoustic detector
Authors: Freitas Taiane A. M. G. , Ribeiro Ricardo M.
Published: September 2020

This report describes a simple and very sensitive modal interferometer (modalmetric) opto‐acoustic detector primarily thought for digital acoustic communications. The modalmetric device was made from a single‐mode fiber spliced with a sensitive multimode fiber (s‐MMF) strand. A nonlinear increase of the phase‐shift and a higher effective sensitivity of the device were observed when the interaction length of the s‐MMF in contact with the surface receiving acoustic signals was increased from 5 to 25 cm and also when the s‐MMF was bent—scaling and bend effects. A sensitivity increase of 14.2 dB was measured for very weak acoustic signals caused by at least three interfering modes. All tests in the proof‐of‐principle basis were performed at 42.9 kHz carrier frequency and 1550 nm wavelength.
CT artifact correction for sparse and truncated projection data using generative adversarial networks
Authors: Podgorsak Alexander R , Shiraz Bhurwani Mohammad Mahdi , Ionita Ciprian N
Published: September 2020

Purpose

Computed tomography image reconstruction using truncated or sparsely acquired projection data to reduce radiation dose, iodine volume, and patient motion artifacts has been widely investigated. To continue these efforts, we investigated the use of machine learning‐based reconstruction techniques using deep convolutional generative adversarial networks (DCGANs) and evaluated its effect using standard imaging metrics.

Methods

Ten thousand head computed tomography (CT) scans were collected from the 2019 RSNA Intracranial Hemorrhage Detection and Classification Challenge dataset. Sinograms were simulated and then resampled in both a one‐third truncated and one‐third sparse manner. DCGANs were tasked with correcting the incomplete projection data, either in the sinogram domain where the full sinogram was recovered by the DCGAN and then reconstructed, or the reconstruction domain where the incomplete data were first reconstructed and the sparse or truncation artifacts were corrected by the DCGAN. Seventy‐five hundred images were used for network training and 2500 were withheld for network assessment using mean absolute error (MAE), structural similarity index measure (SSIM), and peak signal‐to‐noise ratio (PSNR) between results of different correction techniques. Image data from a quality‐assurance phantom were also resampled in the two manners and corrected and reconstructed for network performance assessment using line profiles across high‐contrast features, the modulation transfer function (MTF), noise power spectrum (NPS), and Hounsfield Unit (HU) linearity analysis.

Results

Better agreement with the fully sampled reconstructions were achieved from sparse acquisition corrected in the sinogram domain and the truncated acquisition corrected in the reconstruction domain. MAE, SSIM, and PSNR showed quantitative improvement from the DCGAN correction techniques. HU linearity of the reconstructions was maintained by the correction techniques for the sparse and truncated acquisitions. MTF curves reached the 10% modulation cutoff frequency at 5.86 lp/cm for the truncated corrected reconstruction compared with 2.98 lp/cm for the truncated uncorrected reconstruction, and 5.36 lp/cm for the sparse corrected reconstruction compared with around 2.91 lp/cm for the sparse uncorrected reconstruction. NPS analyses yielded better agreement across a range of frequencies between the resampled corrected phantom and truth reconstructions.

Conclusions

We demonstrated the use of DCGANs for CT‐image correction from sparse and truncated simulated projection data, while preserving imaging quality of the fully sampled projection data.
Fully self‐gated whole‐heart 4D flow imaging from a 5‐minute scan
Authors: Pruitt Aaron , Rich Adam , Liu Yingmin , Jin Ning , Potter Lee , Tong Matthew , Rajpal Saurabh , Simonetti Orlando , Ahmad Rizwan
Published: September 2020

Purpose

To develop and validate an acquisition and processing technique that enables fully self‐gated 4D flow imaging with whole‐heart coverage in a fixed 5‐minute scan.

Theory and Methods

The data are acquired continuously using Cartesian sampling and sorted into respiratory and cardiac bins using the self‐gating signal. The reconstruction is performed using a recently proposed Bayesian method called ReVEAL4D. ReVEAL4D is validated using data from 8 healthy volunteers and 2 patients and compared with compressed sensing technique, L1‐SENSE.

Results

Healthy subjects—Compared with 2D phase‐contrast MRI (2D‐PC), flow quantification from ReVEAL4D shows no significant bias. In contrast, the peak velocity and peak flow rate for L1‐SENSE are significantly underestimated. Compared with traditional parallel MRI‐based 4D flow imaging, ReVEAL4D demonstrates small but significant biases in net flow and peak flow rate, with no significant bias in peak velocity. All 3 indices are significantly and more markedly underestimated by L1‐SENSE. Patients—Flow quantification from ReVEAL4D agrees well with the 2D‐PC reference. In contrast, L1‐SENSE markedly underestimated peak velocity.

Conclusions

The combination of highly accelerated 5‐minute Cartesian acquisition, self‐gating, and ReVEAL4D enables whole‐heart 4D flow imaging with accurate flow quantification.
Determining the effects of traditional learning approach and interactive learning activities on personal and professional factors among Saudi intern nurses
Authors: AlKhaibary Ahmad A. , Ramadan Faten Z. , Aboshaiqah Ahmad E. , Baker Omar G. , AlZaatari Salwa Z. , AlZaatari Salim Z.
Published: September 2020

Aim

This study determines the impact of traditional and interactive learning activities on personal and professional development among Saudi intern nurses.

Design

A comparative research design was adopted by recruiting 48 intern nurses, who were divided into two equal groups.

Methods

Data were collected through the clinical assessment tool for nursing education.

Results

Enthusiasm (p < .0001), initiative (p < .0001), realistic self‐confidence (p < .0001), competent cooperation with staff (p < .0001) and competent cooperation with patients (p < .0001) were significantly higher among the interactive learning activity group compared with traditional group. The interactive learning activity showed better attitude of Saudi intern nurses in terms of caring, respect and sensitivity towards the needs and well‐being of their patients, while considering personal factors.
Effect of series explosion effects on the fiber length, fiber dispersion and structure properties in glass fiber reinforced polyamide 66
Authors: Guo Kang , Wang Dazhong , Zhang Guizhen , Song Jian , Wu Ting , Qu Jinping
Published: September 2020

Nowadays, glass fiber (GF) reinforced polyamide 66 (PA66) composites have attracted strong interests in commercial and engineering applications due to many advantages, such as corrosion resistance, high potential of integration, self‐lubricating, and high toughness. However, it is very difficult for traditional plastic molding equipment to concurrently obtain the increase of fiber retention length and the improvement of fiber dispersion during the PA66/GF composites manufacturing, which greatly limit the widespread application of such composites. An innovative twin eccentric rotor volume pulsating plasticizing transportation equipment (TERE) based on series explosion effects, is applied to prepare PA66/GF composites at different rotor speeds and fiber loadings. Inside the PA66/GF30 composite prepared by TERE, the fibers are evenly dispersed in polymer matrix and the average fiber length increases by 3.2 times when compared to that of twin‐screw plasticizing transportation equipment (TSE). The Charpy impact strength of PA66/GF composites prepared by TERE is nearly twice that of TSE at all fiber contents. The fatigue properties, thermal oxygen aging properties, and creep properties of the TERE composites exhibit better effects than the TSE composites, indicating that the TERE can ensure longer fiber length and better dispersion effect simultaneously.
The effect of incorporation of hybrid silica and cobalt ferrite nanofillers on the mechanical characteristics of glass fiber‐reinforced polymeric composites
Authors: Megahed M. , Tobbala D. E. , El‐baky M. A. Abd
Published: September 2020

Recently, hybrid nanofillers loading has been utilized to fabricate multifunctional composites. In this study, silica (SiO2) and cobalt ferrite (CoFe2O4) nanoparticles were combined to form a new hybrid composite structure. Nanofilled glass/epoxy hybrid composite laminates were fabricated using hand lay‐up technique. SiO2/CoFe2O4hybrid fillers were dispersed in epoxy matrix with sonication. The effect of incorporating SiO2/CoFe2O4hybrid nanoparticles on the mechanical properties of glass fiber/epoxy composites was investigated. The resultant SiO2/CoFe2O4hybrid nanocomposites showed good mechanical properties as compared to hybrid nanocomposites fabricated by individually loading SiO2or CoFe2O4nanoparticles as well as pristine glass fiber/epoxy composite. A visible improvement in the mechanical properties was observed with hybrid nanocomposite that consisted of CoFe2O4/epoxy core layers and SiO2/epoxy skin layers detached with intermediate layers of hybrid SiO2 + CoFe2O4/epoxy. Scanning electron microscopic (SEM) images of tensile and flexural fractured surfaces reveal a good fiber/matrix interfacial bonding.
The effect of barium titanate ceramic loading on the stress relaxation behavior of barium titanate‐silicone elastomer composites
Authors: Cholleti Eshwar Reddy , Stringer Jonathan , Kelly Piaras , Bowen Chris , Aw Kean
Published: September 2020

The stress relaxation behavior of barium titanate (BTO)‐elastomer (Ecoflex) composites, as used in large strain sensors, is studied using the generalized Maxwell‐Wiechert model. In this article, we examine the stress relaxation behavior of ceramic polymer composites by conducting stress relaxation tests on samples prepared with varying the particle loading by 0, 10, 20, 30, and 40 wt% of 100 and 200 nm BTO ceramic particles embedded in a Ecoflex silicone‐based hyperelastic elastomer. The influence of BTO on the Maxwell‐Wiechert model parameters was studied through the stress relaxation results. While a pristine Ecoflex silicone elastomer is predominantly a hyperelastic material, the addition of BTO made the composite behave as a visco‐hyperelastic material. However, this behavior was shown to have a negligible effect on the electrical sensing performance of the large strain sensor.
Do proton pump inhibitors increase mortality? A systematic review and in‐depth analysis of the evidence
Authors: Ben‐Eltriki Mohamed , Green Carolyn J. , Maclure Malcolm , Musini Vijaya , Bassett Ken L. , Wright James M.
Published: September 2020

Proton pump inhibitors (PPIs) were primarily approved for short‐term use (2 to 8 weeks). However, PPI use continues to expand. Widely believed to be safe, we reviewed emerging evidence on increased mortality with PPI long‐term use. Our 2016 systematic PPI drug class review found that mortality was not reported as an outcome in randomized controlled trials (RCTs) that directly compared different PPIs. We sought more recent and comprehensive data on PPI harm outcomes from research syntheses as a follow‐on. A search was conducted from January 2014 to January 2020. We searched MEDLINE, EMBASE, and Cochrane Central for evidence from systematic reviews (SRs) and primary studies reporting all‐cause mortality in adults treated with a PPI for any indication (duration >12 weeks) compared to patients without PPI treatment (no use, placebo, or H2RA use). Two independent investigators assessed study eligibility, synthesized evidence, and assessed the quality of the included studies. Data on all‐cause mortality were sought, analyzed, critically examined, and interpreted herein. From 1304 articles, one SR was identified that reported on all‐cause mortality. The SRs pooled three observational studies with data to 1 year: odds ratio, 95% confidence interval (CI) 1.53‐1.84. A RCT, the COMPASS (Cardiovascular Outcomes for People Using Anticoagulant Strategies) RCT with data to 3 years: hazard ratio (HR) 1.03, 95% CI 0.92‐1.15. The US Veterans Affairs cohort study using a large national dataset with data to 10 years found a HR of 1.17, 95% CI (1.10‐1.24) and (NNH) of 22. The most common causes of death were from cardiovascular and chronic kidney diseases, with an excess death of 15 and 4 per 1000 patients, respectively, over the 10‐year period. Harms arising from real‐world medication use are best evaluated using a pharmacovigilance “convergence of proof” approach using data from a variety of sources and various study designs. Given that most PPI indications for use recommended a treatment duration of less than 12 weeks, it seems clear that PPIs were significantly overused in older patients. The median exposure time to PPI ranged from 1 to 4.6 years. Signals of serious harms including increased mortality with long‐term PPI use are reported in observational studies. The COMPASS trial findings are not inconsistent with contemporaneous findings from observational studies. The COMPASS RCT was unlikely to detect an increase in mortality given the trial was not powered to detect this outcome. The potential increase in mortality in older patients associated with prolonged PPI exposure needs to be conveyed to health professionals. Clinicians and patients may be able to reverse the relentless expansion of long‐term PPI exposure by reviewing indications and considering potential harms as well as benefits.
Efficacy of combined therapy with fish oil and phytocannabinoids in murine intestinal inflammation
Authors: Pagano Ester , Iannotti Fabio A. , Piscitelli Fabiana , Romano Barbara , Lucariello Giuseppe , Venneri Tommaso , Di Marzo Vincenzo , Izzo Angelo A. , Borrelli Francesca
Published: September 2020

Fish oil (FO) and phytocannabinoids have received considerable attention for their intestinal anti‐inflammatory effects. We investigated whether the combination of FO with cannabigerol (CBG) and cannabidiol (CBD) or a combination of all three treatments results in a more pronounced intestinal antiinflammatory action compared to the effects achieved separately. Colitis was induced in mice by 2,4‐dinitrobenzenesulfonic acid (DNBS). CBD and CBG levels were detected and quantified by liquid chromatography coupled with time of flight mass spectrometry and ion trap mass spectrometry (LC‐MS‐IT‐TOF). Endocannabinoids and related mediators were assessed by LC‐MS. DNBS increased colon weight/colon length ratio, myeloperoxidase activity, interleukin‐1β, and intestinal permeability. CBG, but not CBD, given by oral gavage, ameliorated DNBS‐induced colonic inflammation. FO pretreatment (at the inactive dose) increased the antiinflammatory action of CBG and rendered oral CBD effective while reducing endocannabinoid levels. Furthermore, the combination of FO, CBD, and a per se inactive dose of CBG resulted in intestinal anti‐inflammatory effects. Finally, FO did not alter phytocannabinoid levels in the serum and in the colon. By highlighting the apparent additivity between phytocannabinoids and FO, our preclinical data support a novel strategy of combining these substances for the potential development of a treatment of inflammatory bowel disease.
Evolution of errors in the global multiresolution model for prediction across scales: Shallow water (MPAS–SW)
Authors: Tian Xiaoxu
Published: September 2020

The global Model for Prediction Across Scales (MPAS) with shallow‐water (SW) dynamics is taken as the forecast model to characterize the errors under a variable‐resolution (VR) mesh. An idealized experiment featuring gravity and Rossby waves triggered by orography is conducted with two meshes consisting of the same number of grid cells, which directly indicates the computational cost. One mesh is of 120‐km uniform resolution (UR), the other has 53–210 km VR. Both simulations are compared with the solutions from a 60‐km uniform high‐resolution (HR) mesh serving as the reference. The differences with respect to the HR results for both UR and VR experiments are manifested as rapidly propagating gravity waves circling the Earth about every two days. These signals are regarded as errors due to insufficient resolution. Over most of the Earth, the resolution of the VR mesh is coarser than that of the UR mesh. The magnitudes of the errors in the VR experiment are found to grow larger than those in the UR case shortly after the simulation starts. The sensitivities to the errors in the eight‐day forecast calculated with the MPAS–SW adjoint model show similar propagation patterns, following a nonlinear state trajectory. The sensitivities under VR suggest that little contribution to the errors throughout the simulation process is made within the finely resolved areas. In the initial conditions under VR, the error signals come primarily from the coarse‐resolution regions immediately outside the areas with enhanced resolution. This finding implies that, in simulations under VR, error signals generated in the coarsely resolved regions can be propagated into the finely resolved areas when conveyed by wave types allowed in the model, that is, gravity waves in the case of this study, the rate of which depends on the fluid mean height.
Interface formation of Al2O3 on n‐GaN(0001): Photoelectron spectroscopy studies
Authors: Lewandków Rafał , Grodzicki Miłosz , Mazur Piotr , Ciszewski Antoni
Published: September 2020

Al2O3 insulator layers were deposited step by step by the physical vapor deposition (PVD) method onto gallium nitride in the wurtzite form, n‐type and (0001)‐oriented. The substrate surface and the early stages of Al2O3/n‐GaN(0001) interface formation were characterized in situ under ultra‐high vacuum conditions by X‐ray and ultraviolet photoelectron spectroscopy (XPS, UPS). The electron affinity (EA) of the substrate cleaned by annealing was 3.6 eV. Binding energies of the Al 2p (76.0 eV) and the O 1s (532.9 eV) confirmed the creation of the Al2O3 compound in the deposited film for which the EA was 1.6 eV. The Al2O3 film was found to be amorphous with a bandgap of 6.9 eV determined from the O 1s loss feature. As a result, the calculated Al2O3/n‐GaN(0001) valence band offset (VBO) is −1.3 eV and the corresponding conduction band offset (CBO) 2.2 eV.
Antimonene Quantum Dots as an Emerging Fluorescent Nanoprobe for the pH‐Mediated Dual‐Channel Detection of Tetracyclines
Authors: Liu Yingnan , Xiao Yaqing , Yu Min , Cao Yuanyuan , Zhang Yalan , Zhe Taotao , Zhang Hui , Wang Li
Published: September 2020

Antimonene quantum dots (AMQDs) are attracting considerable attention due to their fascinating physicochemical properties. However, research on their semiconductor characteristics, especially the photoluminescence performance, is still in a preliminary stage and the experimental verification is scarcely reported, significantly restricting their further applications. Herein, the photoluminescence property of AMQDs is experimentally verified. The AMQDs are prepared by probe sonication‐assisted liquid‐phase exfoliation and show robust blue fluorescence, and the photoluminescence is hardly affected by pH. In view of the derivatization reaction of tetracyclines (TET) at different pHs, AMQDs are developed as a pH‐mediated dual‐channel ratiometric fluorescent probe for TET detection. Under acidic conditions, the AMQDs’ probe exhibits unique recognition behavior due to the inherent fluorescence of TET and the solvent‐enhancing effect, that is, the fluorescence changes from blue to red. Under alkaline conditions, this fluorescent probe realizes the transition from blue to yellow‐green because of the decomposition of TET. The limits of detection are 27 × 10−9 and 74 × 10−9 m, respectively. The high sensitivity and remarkable fluorescence changes make AMQDs ideal probes for TET sensing. Additionally, this is the first report on the photoluminescence property of AMQDs. It is believed that this work will open a new avenue for AMQDs in optical sensing fields.
Engineering Hierarchical CoO Nanospheres Wrapped by Graphene via Controllable Sulfur Doping for Superior Li Ion Storage
Authors: Hu Yifan , Li Zichuang , Hu Zhongchao , Wang Liang , Ma Ruguang , Wang Jiacheng
Published: September 2020

The inferior conductivity and large volume expansion impair the widespread applications of metal oxide‐based anode materials for lithium‐ion batteries. To address these issues, herein an efficient strategy of structural engineering is proposed to improve lithium storage performance of hierarchical CoO nanospheres wrapped by graphene via controllable S‐doping (CoOS0.1  @ G). S‐doping promotes the Li+ diffusion kinetics of CoO by expanding the interplanar spacing of CoO, lowering the activation energy, and improving the pseudocapacitance contribution. Meanwhile, the electronic structure of CoO is adjusted by S‐doping as confirmed by density functional theory calculations, thus enhancing the conductivity. Finite element analysis reveals that the produced Li2S during lithiation improves the structural stability of the S‐doped electrode, which is further confirmed by experimental observation. As expected, CoOS0.1  @ G exhibits excellent lithium storage performance with an initial discharge capacity of 1974 mAh g−1 at 100 mA g−1, and high discharge capacity of 1573 mAh g−1 after 400 cycles at 500 mA g−1. It is believed that the insights into the structural doping enlighten research to explore other metal oxides for fast and stable Li ion storage.
Adaptive Synaptic Memory via Lithium Ion Modulation in RRAM Devices
Authors: Lin Chih‐Yang , Chen Jia , Chen Po‐Hsun , Chang Ting‐Chang , Wu Yuting , Eshraghian Jason K. , Moon John , Yoo Sangmin , Wang Yu‐Hsun , Chen Wen‐Chung , Wang Zhi‐Yang , Huang Hui‐Chun , Li Yi , Miao Xiangshui , Lu Wei D. , Sze Simon M.
Published: September 2020

Biologically plausible computing systems require fine‐grain tuning of analog synaptic characteristics. In this study, lithium‐doped silicate resistive random access memory with a titanium nitride (TiN) electrode mimicking biological synapses is demonstrated. Biological plausibility of this RRAM device is thought to occur due to the low ionization energy of lithium ions, which enables controllable forming and filamentary retraction spontaneously or under an applied voltage. The TiN electrode can effectively store lithium ions, a principle widely adopted from battery construction, and allows state‐dependent decay to be reliably achieved. As a result, this device offers multi‐bit functionality and synaptic plasticity for simulating various strengths in neuronal connections. Both short‐term memory and long‐term memory are emulated across dynamical timescales. Spike‐timing‐dependent plasticity and paired‐pulse facilitation are also demonstrated. These mechanisms are capable of self‐pruning to generate efficient neural networks. Time‐dependent resistance decay is observed for different conductance values, which mimics both biological and artificial memory pruning and conforms to the trend of the biological brain that prunes weak synaptic connections. By faithfully emulating learning rules that exist in human's higher cortical areas from STDP to synaptic pruning, the device has the capacity to drive forward the development of highly efficient neuromorphic computing systems.
A Review of Mathematical Process Models for the Electric Arc Furnace Process
Authors: Hay Thomas , Visuri Ville-Valtteri , Aula Matti , Echterhof Thomas
Published: September 2020

The electric arc furnace is the main process unit in scrap‐based steelmaking. Owing to its importance, numerous mathematical models for predicting the course of the electric arc furnace process have been developed. This article reviews mathematical process models proposed in the literature, identifying the most common modeling approaches, and uses mathematical descriptions for the main phenomena. Furthermore, the validation of such models is discussed in detail. Finally, the article identifies gaps in the existing knowledge and provides suggestions for the further development of mathematical process models.
A Pyrrole‐Fused Asymmetrical Electron Acceptor for Polymer Solar Cells with Approaching 16% Efficiency
Authors: Luo Zhenghui , Ma Ruijie , Xiao Yiqun , Ni Fan , Liu Tao , Zhan Qun , Sun Huiliang , Chen Yuzhong , Zou Yang , Lu Xinhui , Yan He , Yang Chuluo
Published: September 2020

Selecting suitable aromatic rings to develop asymmetric small‐molecule acceptors (SMAs) is of great significance. Herein, two asymmetric SMAs, namely, BTN‐4F and BTSe‐4F, are successfully synthesized by incorporating pyrrole and selenophene unit into the cores, respectively. Compared with the selenophene‐fused counterpart BTSe‐4F, BTN‐4F displays slightly upshifted energy levels and red‐shifted absorption spectrum (about 40 nm in film) due to the strong electron‐donating ability of N atoms in pyrrole. When matching with PM6, the BTN‐4F‐based device gives a higher power conversion efficiency (PCE) (15.82%) due to the simultaneously enhanced open circuit voltage (VOC), short‐circuit current density (JSC), and fill factor (FF), compared with those of the BTSe‐4F‐based device. The higher VOC coincides with the shallower lowest unoccupied molecular orbital (LUMO) energy level of BTN‐4F; the enhanced JSC mainly results from the broadened and enhanced absorption; the increased FF can be ascribed to the weaker bimolecular recombination, more balance charge transport, and more favorable morphology. It should be mentioned that the BTN‐4F‐based device yields a lower energy loss than that of the BTSe‐4F‐based device. Overall, the work demonstrates that pyrrole‐fused SMAs shows great potential in realizing low Eloss while yielding high JSC and PCE, which paves a new way to develop high‐performance SMAs.
Recent Progress on High‐Performance Cathode Materials for Zinc‐Ion Batteries
Authors: Zhang Maiwen , Liang Ruilin , Or Tyler , Deng Ya-Ping , Yu Aiping , Chen Zhongwei
Published: September 2020

Rechargeable zinc‐ion batteries (ZIBs) have emerged as a contender in the area of electrochemical energy storage applications due to their low cost and inherent safety. To optimize the battery performances, ZIBs cathode materials with high capacity and cyclability have been intensively studied, with most attention focused on traditional manganese‐ and vanadium‐based materials. Recently, other novel cathode materials including Prussian blue analogues (PBAs), polyanions, metal sulfides, and organic compounds have begun to gain recognition as promising alternatives. These materials exhibit distinct strength such as high operating voltage, additional capacity by new redox chemistry activation, and/or highly reversible cycling process that are particularly desirable for ZIBs applications. To provide the highlight they deserve, this review focuses on introducing the recent progresses of these ZIBs cathodes and demonstrating common strategies adopted for material modification and optimization. Finally, systematic comparisons among the cathode materials are analyzed, along with challenges and perspectives on each category of the cathodes.
Making the most of all data: Combining non‐genotyped and genotyped potato individuals with HBLUP
Authors: Sood Salej , Lin Zibei , Caruana Brittney , Slater Anthony T. , Daetwyler Hans D.
Published: September 2020

Using genomic information to predict phenotypes can improve the accuracy of estimated breeding values and can potentially increase genetic gain over conventional breeding. In this study, we investigated the prediction accuracies achieved by best linear unbiased prediction (BLUP) for nine potato phenotypic traits using three types of relationship matrices pedigree ABLUP, genomic GBLUP, and a hybrid matrix (H) combining pedigree and genomic information (HBLUP). Deep pedigree information was available for >3000 different potato breeding clones evaluated over four years. Genomic relationships were estimated from >180,000 informative SNPs generated using a genotyping‐by‐sequencing transcriptome (GBS‐t) protocol for 168 cultivars, many of which were parents of clones. Two validation scenarios were implemented, namely “Genotyped Cultivars Validation” (a subset of genotyped lines as validation set) and “Non‐genotyped 2009 Progenies Validation”. Most of the traits showed moderate to high narrow sense heritabilities (range 0.22–0.72). In the Genotyped Cultivars Validation, HBLUP outperformed ABLUP on prediction accuracies for all traits except early blight, and outperformed GBLUP for most of the traits except tuber shape, tuber eye depth and boil after‐cooking darkening. This is evidence that the in‐depth relationship within the H matrix could potentially result in better prediction accuracy in comparison to using A or G matrix individually. The prediction accuracies of the Non‐genotyped 2009 Progenies Validation were comparable between ABLUP and HBLUP, varying from 0.17–0.70 and 0.18–0.69, respectively. Better prediction accuracy and less bias in prediction using HBLUP is of practical utility to breeders as all breeding material is ranked on the same scale leading to improved selection decisions. In addition, our approach provides an economical alternative to utilize historic breeding data with current genotyped individuals in implementing genomic selection.
Water, justice, and wellbeing in the Kamiesberg, Namaqualand: Reflecting on local histories in the context of the Anthropocene
Authors: Cohen Joshua Benjamin
Published: September 2020

This paper explores relationships between water and well‐being in the Leliefontein Pastoral Area, Namaqualand, South Africa. Despite its geographical focus, it nonetheless articulates with broader regional and national debates around water in the Anthropocene. As a positive response to calls for water justice in South Africa, the paper argues for the need for water justice that is attuned to the particularities of South Africa's complex social‐ecologies. In order to make this case, the paper explores a regional literature rich in works in the disciplines of environmental history, anthropology and ecology that demonstrates deep entanglements between water, dispossession of land, and oppressive power in the Leliefontein Pastoral Area, and Namaqualand more generally. Because of the histories and ways of life it describes, the literature underscores the need to consider wellbeing as it relates to water in varying forms—as that which flows through pipes and taps, but also that which cycles through the air, falls on the ground, is taken up by plants, and eaten by stock animals. A consideration of Leliefontein's water history also surfaces the historically delimited nature of water that is primarily known as a natural resource, measured in liters and assessed in terms of its microbial and chemical contents. Other kinds of waters exist and persist in the area and are also vital to how many people experience and think about their own wellbeing. This becomes especially significant in the face of expected effects of climate change in the region.

This article is categorized under:

Human Water > Human Water