bluuebunny/crossref_metadata_2025 huggingface dataset:
Metatarsal Head Resections in Diabetic Foot Patients: A Systematic Review
Authors: Sanz-Corbalán Irene , Tardáguila-García Aroa , García-Alamino Josep M. , García-Álvarez Yolanda , Álvaro-Afonso Francisco Javier , Lázaro-Martínez José Luis
Published: June 2020

A systematic review and proportional meta-analysis were carried out to investigate the complications that occur after surgical metatarsal head resection in diabetic foot patients. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist recommendations were applied, and the selected studies were evaluated using a Strengthening the Reporting of Observational studies in Epidemiology (STROBE) checklist. PubMed (Medline) and Embase (Elsevier) were searched in December 2019 to find clinical trials, cohort studies, or case series assessing the efficacy of the metatarsal head resection technique in diabetic foot patients. The systematic review covered 21 studies that satisfied the inclusion criteria and included 483 subjects. The outcomes evaluated were the time to heal, recurrence, reulceration, amputation, and other complications. The proportion of recurrence was 7.2% [confidence interval (CI) 4.0–10.4, p < 0.001], that of reulceration was 20.7% (CI 11.6–29.8, p < 0.001), and that of amputation was 7.6% (CI 3.4–11.8, p < 0.001). A heterogeneity test indicated I2 = 72.6% (p < 0.001) for recurrences, I2 = 94% (p < 0.001) for reulcerations, and I2 = 79% (p < 0.001) for amputations. We conclude that metatarsal head resections in diabetic foot patients are correlated with significant complications, especially reulceration.
Altered Cortical Thickness-Based Individualized Structural Covariance Networks in Patients with Schizophrenia and Bipolar Disorder
Authors: Kim Sungkean , Kim Yong-Wook , Jeon Hyeonjin , Im Chang-Hwan , Lee Seung-Hwan
Published: June 2020

Structural covariance is described as coordinated variation in brain morphological features, such as cortical thickness and volume, among brain structures functionally or anatomically interconnected to one another. Structural covariance networks, based on graph theory, have been studied in mental disorders. This analysis can help in understanding the brain mechanisms of schizophrenia and bipolar disorder. We investigated cortical thickness-based individualized structural covariance networks in patients with schizophrenia and bipolar disorder. T1-weighted magnetic resonance images were obtained from 39 patients with schizophrenia, 37 patients with bipolar disorder type I, and 32 healthy controls, and cortical thickness was analyzed via a surface-based morphometry analysis. The structural covariance of cortical thickness was calculated at the individual level, and covariance networks were analyzed based on graph theoretical indices: strength, clustering coefficient (CC), path length (PL) and efficiency. At the global level, both patient groups showed decreased strength, CC and efficiency, and increased PL, compared to healthy controls. In bipolar disorder, we found intermediate network measures among the groups. At the nodal level, schizophrenia patients showed decreased CCs in the left suborbital sulcus and the right superior frontal sulcus, compared to bipolar disorder patients. In addition, patient groups showed decreased CCs in the right insular cortex and the left superior occipital gyrus. Global-level network indices, including strength, CCs and efficiency, positively correlated, while PL negatively correlated, with the positive symptoms of the Positive and Negative Syndrome Scale for patients with schizophrenia. The nodal-level CC of the right insular cortex positively correlated with the positive symptoms of schizophrenia, while that of the left superior occipital gyrus positively correlated with the Young Mania Rating Scale scores for bipolar disorder. Altered cortical structural networks were revealed in patients, and particularly, the prefrontal regions were more altered in schizophrenia. Furthermore, altered cortical structural networks in both patient groups correlated with core pathological symptoms, indicating that the insular cortex is more vulnerable in schizophrenia, and the superior occipital gyrus is more vulnerable in bipolar disorder. Our individualized structural covariance network indices might be promising biomarkers for the evaluation of patients with schizophrenia and bipolar disorder.
Deterioration of Retinal Blood Flow Parameters in Branch Retinal Vein Occlusion Measured by Doppler Optical Coherence Tomography Flowmeter
Authors: Takahashi Kengo , Song Youngseok , Sogawa Kenji , Yoshioka Takafumi , Tani Tomofumi , Ishiko Satoshi , Yoshida Akitoshi
Published: June 2020

Background: Doppler optical coherence tomography (DOCT) flowmeter can be used to measure retinal blood flow (RBF) parameters, including vessel diameter, blood velocity, and the absolute value of RBF within 2.0 s. We investigated the RBF parameters in eyes with branch retinal vein occlusion (BRVO) using a DOCT flowmeter. Methods: Seventeen patients with unilateral BRVO were enrolled. All subjects underwent comprehensive ophthalmologic examinations. The RBF parameters were assessed from three veins, i.e., (1) an occluded vein, (2) a non-occluded vein in the BRVO eyes, and (3) an equivalent (superior or inferior) vein in the fellow eye (non-affected vein), using prototype DOCT flowmeter (Topcon, Tokyo, Japan). Moreover, the correlation between RBF parameters and the best corrected visual acuity (BCVA) was examined. We investigated the correlation between (1) the RBF parameters and the time from the initial visit, (2) the RBF parameters and the time from the last injection, and (3) the RBF parameters and the number of anti-vascular endothelial growth factor injections (VEGF). Results: The diameter of the occluded vein (95.9 ± 24.7 µm) was smaller than that of the non-occluded vein (127.9 ± 23.7 µm) and that of the healthy veins (116.4 ± 13.9 µm). The RBF was lower in the occluded veins (4.7 ± 3.7 µL/min) than that in the non-occluded veins (10.3 ± 5.1 µL/min; p < 0.01) and in the fellow eyes (8.6 ± 4.0 µL/min; p = 0.013). In contrast, the blood velocity was not significantly different among the three types of veins. BCVA was correlated with the diameter of the occluded vein (ρ = 0.711, p = 0.001) but not with the RBF and blood velocity. The time from the initial visit, the time from the last injection, and the total number of anti-VEGF injections were not associated with any RBF parameters on the occluded vein. Conclusions: The RBF was significantly lower in the occluded veins than that in the other veins, and the diameter of the occluded vein was significantly smaller than that of the other veins in patients with BRVO. However, neither the time from the initial visit, nor the time from the last injection, nor the number of anti-VEGF injections were correlated with the RBF parameters on the occluded vein.
SKINREMS—A New Method for Assessment of the Niacin Skin Flush Test Response in Schizophrenia
Authors: Karakula-Juchnowicz Hanna , Rog Joanna , Wolszczak Piotr , Jonak Kamil , Stelmach Ewa , Krukow Paweł
Published: June 2020

Schizophrenia has been considered a disorder linked with faulty lipid homeostasis, and the proposed tool for assessment of these disruptions is the niacin skin flush test. The aims of the study were: 1. Create a new tool to analyze results of the niacin skin flush test more precisely and objectively. 2. Verify the utility of a self-created tool for differentiating between schizophrenia (SZ; n = 56), bipolar disorder (BD; n = 29) and healthy control (HC; n = 45) individuals. The proposed developed method, based on the Skin Reaction Measurement Computer System (SKINREMS), allows one to evaluate the response to the niacin skin flush test quickly and objectively. SKINREMS showed good accuracy in discriminating SZ from BD (with sensitivity 91% and specificity 72%), and SZ from HC (71% and 66%, respectively), and sufficient but not excellent accuracy in discriminating BD from HC (55% and 54%, respectively). The pathophysiological pathways and features shared by schizophrenia and bipolar disorder may be the reason for difficulties in fully discriminating between these two mental disorders using the niacin challenge test. The management of disruptions in the phospholipid metabolism and the inflammatory process could potentially become an individualized form of therapy in a subgroup of psychiatric patients.
Effects of Prolonged Type 2 Diabetes on the Inner Retinal Layer and Macular Microvasculature: An Optical Coherence Tomography Angiography Study
Authors: Lee Min-Woo , Lee Woo-Hyuk , Ryu Cheon-Kuk , Kim Tae-Yeon , Lim Hyung-Bin , Lee Young-Hoon , Kim Jung-Yeul
Published: June 2020

Purpose: To identify the effects of prolonged type 2 diabetes (T2DM) on macular microcirculation and the inner retinal layer in diabetic eyes without clinical diabetic retinopathy (DR). Methods: 97, 92, and 57 eyes in the control, patients with T2DM < 10 years (DM group one), and patients with T2DM ≥ 10 years (DM group two) were enrolled. The ganglion cell-inner plexiform layer (GC-IPL) thickness and superficial vessel density (VD) were compared. Linear regression analyses were performed to identify factors associated with VD in T2DM patients. Results: GC-IPL thicknesses in the control, DM group one, and DM group two were 84.58 ± 0.89, 83.49 ± 0.70, and 79.04 ± 0.96 μm, respectively (p < 0.001). The VDs of the full area were 20.32 ± 0.15, 19.46 ± 0.17, and 18.46 ± 0.23 mm−1 (p < 0.001). Post-hoc analyses revealed that the VDs of the full area was significantly different in the control vs. DM group one (p = 0.001), control vs. DM group two (p < 0.001), and DM group one vs. DM group two (p = 0.001). Multivariate linear regression analyses revealed that DM duration (p = 0.037), visual acuity (p = 0.013), and GC-IPL thickness (p < 0.001) were significantly associated with the VD of T2DM patients. Conclusions: We confirmed GC-IPL thinning and decreased superficial VD in the macular areas using OCTA in T2DM patients. Patients with T2DM ≥ 10 years exhibited significantly more severe macular microcirculation impairment compared to patients with T2DM < 10 years and normal controls.
Come in from the Cold: Are Older Adults Who Live in Colder Climates at Greater Risk for Sarcopenia?
Authors: Scott David
Published: June 2020

The operational definition of “sarcopenia”, an age-related skeletal muscle disease resulting from adverse changes that accrue across the lifetime, was recently updated by the European Working Group on Sarcopenia in Older People (EWGSOP) [...]
Performance Assessment of SARS-CoV-2 PCR Assays Developed by WHO Referral Laboratories
Authors: Etievant Sibyle , Bal Antonin , Escuret Vanessa , Brengel-Pesce Karen , Bouscambert Maude , Cheynet Valérie , Generenaz Laurence , Oriol Guy , Destras Gregory , Billaud Geneviève , Josset Laurence , Frobert Emilie , Morfin Florence , Gaymard Alexandre
Published: June 2020

A reliable diagnostic assay is crucial to early detect new COVID-19 cases and limit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. Since the onset of the COVID-19 pandemic, the World Health Organization has published several diagnostic molecular approaches developed by referral laboratories, including Charité (Germany), HKU (Hong Kong), China CDC (China), US CDC (United States), and Institut Pasteur, Paris (France). We aimed to compare the sensitivity and specificity of these different RT-PCR assays using SARS-CoV-2 cell culture supernatants and clinical respiratory samples. Overall, the different RT-PCR assays performed well for SARS-CoV-2 detection and were all specific except the N Charité (Germany), and N2 US CDC (United States) assays. RdRp Institut Pasteur (IP2, IP4), N China CDC, and N1 US CDC were found to be the most sensitive assays. The data presented herein are of prime importance to facilitate the equipment choice of diagnostic laboratories, as well as for the development of marketed tests.
Is Heel Height Associated with Pain Exacerbations in Hip Osteoarthritis Patients?—Results from a Case-Crossover Study
Authors: Fu Kai , Metcalf Ben R. , Bennell Kim L. , Zhang Yuqing , Gross K. Douglas , Mills Kathryn , Deveza Leticia A. , Robbins Sarah R. , Hunter David J.
Published: June 2020

The etiology of osteoarthritis (OA) pain exacerbations is not well understood. The purpose of this study is to evaluate the association of heel height and duration of wearing shoes with higher heels with pain exacerbations in people with hip OA. Eligible participants with symptomatic hip OA were instructed to complete online questionnaires every 10 days over a 90-day follow-up period. They were required to complete the questionnaire whenever they were experiencing hip pain exacerbation. Of 252 participants recruited, 137 (54.4%) contributed both case and control period data, and were included in the analysis. Wearing shoes with a heel height ≥ 2.5 cm during the past 24 h was associated with lower odds of pain exacerbations (OR: 0.54, 95% CI: 0.30 to 0.99). A longer duration (>6 h) of wearing shoes with heel height ≥ 2.5 cm was also associated with a lower risk of hip pain exacerbations (p for linear trend = 0.003). Wearing shoes with heel height ≥ 2.5 cm and longer duration in the past 24 h may be protective against hip pain exacerbations in people with symptomatic hip OA. Given the observational study nature, it would be prudent for this to be replicated in an independent data set.
Self-Assessment of Competence and Referral Behavior for Musculoskeletal Injections among Dutch General Practitioners
Authors: Spruit Emely , Mol Marianne F. , Bos P. Koen , Bierma-Zeinstra Sita M.A. , Krastman Patrick , Runhaar Jos
Published: June 2020

General practitioners (GPs) are qualified and trained to administer therapeutic musculoskeletal injections when indicated. However, it is unknown to what extend Dutch GPs feel competent to administer these injections in clinical practice. Reluctance among GPs to inject might lead to unnecessary and costly referral to secondary care. An online and offline questionnaire was spread among Dutch GPs, querying demographics, GPs’ self-assessment of injection competence, the number of administered/referred injections and management strategy for musculoskeletal injections. A total of 355 GPs responded. In total, 81% of the GPs considered themselves competent in administering musculoskeletal injections. Self-assessed incompetent GPs performed less injections the last month than self-assessed competent GPs (1.2 ± 1.4 vs 4.8 ± 4.6 injections, P < 0.001). Additionally, they referred four times more often to a colleague GP (0.4 ± 1.0 vs 0.1 ± 0.6 injections per month, P < 0.001) and twice as often to secondary care (1.0 ± 1.3 vs 0.5 ± 0.9 injections per month, P = 0.001). Self-assessed incompetence was associated with female sex (OR [95% CI] = 4.94 [2.39, 10.21]) and part-time work (OR [95% CI] = 2.58 [1.43, 4.66]). The most frequently addressed barriers were a lack of confidence in injection skills, lack of practical training, and uncertainty about the effectiveness and diagnosis of musculoskeletal injections. Although most GPs considered themselves competent to administer musculoskeletal injections, the referral rate to secondary care for several injections was strikingly high. To decrease secondary care referrals, addressing some of the most frequently indicated barriers is highly recommended.
Evaluation of Transcatheter Alcohol-Mediated Perivascular Renal Denervation to Treat Resistant Hypertension
Authors: Janas Adam , Król Marek , Hochuł Mariusz , Jochymczyk Monika , Hayward-Costa Claudia , Parise Helen , Haratani Nicole , Fischell Tim , Wojakowski Wojciech
Published: June 2020

Catheter-based renal denervation (RDN) has been investigated for hypertension (HTN) treatment with variable success. One of the novel approaches to RDN is the delivery of micro-doses of dehydrated alcohol to the adventitial space of the renal artery to perform perivascular ablation of the sympathetic nerves. We sought to assess the safety and efficiency of transcatheter alcohol-mediated perivascular renal denervation in patients with resistant hypertension. Fifty adult patients who had been referred for resistant HTN were screened. To qualify for the study, the patients had to have a mean 24 h systolic pressure ≥ 135 mmHg based upon ambulatory blood pressure monitoring (ABPM) and acceptable renal artery anatomy confirmed by the contrast computer tomography (AngioCT) and nephrologist consultation. Ten patients were eligible for chemical RND. There were no safety issues throughout the 24 months of follow-ups. The mean decrease in the office BP (OBP) was significant during 24 months of follow-up (p < 0.01). The difference in the BP in the ABPM was statistically significant in the 1st, 3rd and 12th months (p < 0.01), whereas during the 3-month follow-up, a trend was observed. The modifications of anti-hypertension drugs throughout the follow-up period were minimal. This study has shown that transcatheter alcohol-mediated renal denervation in patients with resistant hypertension is feasible and safe. Nevertheless, it is a hypothesis-generating study.
Widespread Introduction of a High-Sensitivity Troponin Assay: Assessing the Impact on Patients and Health Services
Authors: Greenslade Jaimi H. , Parsonage William , Foran Laura , McCormack Louise , Ashover Sarah , Milburn Tanya , Berndt Sara , Than Martin , Brain David , Cullen Louise
Published: June 2020

Adoption of High-sensitivity troponin (hs-cTn) assays by hospitals worldwide is increasing. We sought to determine the effects of a simultaneous state-wide hs-cTn assay introduction on the implementing health service. A quasi-experimental pre–post design was used. Participants included all adult patients presenting to 21 Australian hospitals who had troponin testing commenced within the Emergency Department (ED). Data were collected for 124,357 episodes of care between 30 April 2018 and 23 April 2019; six months pre- and six months post-implementation of the assay. The primary outcome was hospital length of stay (LOS). Secondary outcomes included ED LOS, 90-day cardiovascular mortality, elevated troponin, diagnosis of acute myocardial infarction (AMI), admission to a cardiology ward, invasive cardiac procedures, and total hospital costs. Following hs-cTn implementation, there was a 1.9-h (95% CI: −2.9 to −1.0 h) reduction in overall LOS. This equated to a cost saving of over 9 million Australian dollars per year. There was no increase in diagnosis of AMI, invasive cardiac procedures or ward admissions. The use of hs-cTn assays facilitates important benefits for health services by enabling more rapid evaluation protocols within the ED. This benefit may be considerable given the large cohort of emergency patients with possible ACS.
Novel Coatings to Minimize Bacterial Adhesion and Promote Osteoblast Activity for Titanium Implants
Authors: Camargo Samira E. A. , Roy Tanaya , Carey IV Patrick H. , Fares Chaker , Ren Fan , Clark Arthur E. , Esquivel-Upshaw Josephine F.
Published: June 2020

Titanium nitride (TiN) and silicon carbide (SiC) adhesion properties to biofilm and the proliferation of human osteoblasts were studied. Quaternized titanium nitride (QTiN) was produced by converting the surface nitrogen on TiN to a positive charge through a quaternization process to further improve the antibacterial efficiency. The SiC required a nitridation within the plasma chamber of the surface layer before quaternization could be carried out to produce quaternized SiC (QSiC). The antimicrobial activity was evaluated on the reference strains of Porphyromonas gingivalis for 4 h by fluorescence microscopy using a live/dead viability kit. All the coatings exhibited a lower biofilm coverage compared to the uncoated samples (Ti—85.2%; TiN—24.22%; QTiN—11.4%; SiC—9.1%; QSiC—9.74%). Scanning Electron Microscope (SEM) images confirmed the reduction in P. gingivalis bacteria on the SiC and TiN-coated groups. After 24 h of osteoblast cultivation on the samples, the cell adhesion was observed on all the coated and uncoated groups. Fluorescence images demonstrated that the osteoblast cells adhered and proliferated on the surfaces. TiN and SiC coatings can inhibit the attachment of Porphyromonas gingivalis and promote osteoblast adhesion on the titanium used for implants. These coatings may possess the ability to prevent the development of peri-implantitis and stimulate osteointegration.
Hydro- and Morphodynamic Impacts of Sea Level Rise: The Minho Estuary Case Study
Authors: Melo Willian , Pinho José , Iglesias Isabel , Bio Ana , Avilez-Valente Paulo , Vieira José , Bastos Luísa , Veloso-Gomes Fernando
Published: June 2020

The understanding and anticipating of climate change impacts is one of the greatest challenges for humanity. It is already known that, until the end of the 21st century, the mean sea level (MSL) will rise at a global scale, but its effects at the local scale need to be further analyzed. In this context, a numerical modelling tool and a methodological approach for the river Minho estuary (NW of the Iberian Peninsula) are presented, to predict possible consequences of local MSL rise, considering the greenhouse emission scenarios RCP 4.5 and RCP 8.5. Hydrodynamic and morphodynamic impacts were analyzed considering several driving factors, such as tides, sea level rise, storm surge, wave set-up, and different river flood peak discharges, taking into account their probabilities of occurrence. The model was calibrated using in-situ data and a data assimilation tool, the OpenDA, which automates this process, allowing to reach reliable results in a considerably short time when compared with traditional techniques. The results forecast that the predicted MSL rise will reduce the flow velocity magnitude and the sediment transport into the coastal platform but will aggravate the inundation risks along the estuarine banks. In the worst scenario (RCP 8.5) the water level near the river mouth of the estuary is expected to rise 0.20 m for 50 years return period ocean water rising, and 0.60 m for 100 years return period. It was also possible to identify that floods are the most important driver for the sediment transport along the estuary, while the tide effect in the morphodynamics is restricted to the downstream estuarine region. This work demonstrated the importance of the numerical modelling tools to better understand the effects of climate change at local scales through the representation of the estuarine hydrodynamic pattern evolution for future climate scenarios.
The More You Search, the More You Find: A New Mediterranean Endemism of the Genus Ocenebra Gray, 1847 (Mollusca: Gastropoda: Muricidae) from a Submarine Cave of the Messina Strait Area (Italy)
Authors: Crocetta Fabio , Houart Roland , Bonomolo Giuseppe
Published: June 2020

Three hundred years of study on the Mediterranean molluscan fauna led the scientific community to consider it as the best ever known. However, the rate at which new taxa are discovered and described every year is still remarkably high, even in key predators such as Muricidae Rafinesque, 1815. Within this family, the genus Ocenebra Gray, 1847 comprises species widely distributed in the northeastern Atlantic and the Mediterranean Sea that were already the target of a decadal nomenclatural, morphological, and molecular combined research. Notwithstanding, we hereby describe an additional ocenebrid endemism from the Mediterranean Sea, whose distribution appears to be restricted to a circalittoral submarine cave of the Messina Strait area (Italy). The new species Ocenebra vazzanai is compared with the recent Atlanto-Mediterranean congeneric taxa on the basis of the known type materials, and a table summarizing the main diagnostic features of the species is offered to facilitate future identifications. The high biodiversity highlighted in the genus Ocenebra reveals a wide adaptive radiation and suggests the necessity of further studies aiming to tackle biodiversity issues even in popular groups, such as molluscs, and in widely studied biogeographic areas, such as Italy, and the Mediterranean basin in general.
Analysis of Sealing and Leakage Performance of the Subsea Collet Connector with Lens-Type Sealing Structure
Authors: Yun Feihong , Wang Gang , Yan Zheping , Jia Peng , Xu Xiujun , Wang Liquan , Sun Haiting , Liu Weifeng
Published: June 2020

The contact mechanics model of the metal lens-type sealing gasket is established on the basis of Hertz theory on the macroscopical scale in this paper. The relationship among sealing width, contact pressure, and preload is solved. Based on the structural characteristics of the subsea collet connector, the self-locking characteristics are analyzed to determine the gain coefficient of the sealing structure for the loading thrust. On the microscopic scale, the contact characteristics of the turning lens-type sealing gasket and the hub structure are analyzed by the equivalent replacement of the peak cut coefficient of the one-dimensional sinusoidal wave. The influence of different leakage forms on sealing performance is discussed from both radial and circumferential leakage, and the leakage rate of the lens-type sealing structure is calculated. The hydrostatic pressure experiment of the subsea collet connector with lens-type sealing gasket is carried out, and the correctness of the theoretical analysis is verified from the results of the pressure maintaining, sealing width measurement, and preload conversion.
Ectomycorrhizal Fungal Inoculation of Sphaerosporella brunnea Significantly Increased Stem Biomass of Salix miyabeana and Decreased Lead, Tin, and Zinc, Soil Concentrations during the Phytoremediation of an Industrial Landfill
Authors: Dagher Dimitri J. , Pitre Frédéric E. , Hijri Mohamed
Published: June 2020

Fast growing, high biomass willows (Salix sp.) have been extensively used for the phytoremediation of trace element-contaminated environments, as they have an extensive root system and they tolerate abiotic stressors such as drought and metal toxicity. Being dual mycorrhizal plants, they can engage single or simultaneous symbiotic associations with both arbuscular mycorrhizal (AM) fungi and ectomycorrhizal (EM) fungi, which can improve overall plant health and growth. The aim of this study was to test the effect of these mycorrhizal fungi on the growth and trace element (TE) extraction potential of willows. A field experiment was carried out where we grew Salix miyabeana clone SX67 on the site of a decommissioned industrial landfill, and inoculated the shrubs with an AM fungus Rhizophagus irregularis, an EM fungus Sphaerosporella brunnea, or a mixture of both. After two growing seasons, the willows inoculated with the EM fungus S. brunnea produced significantly higher biomass. Ba, Cd and Zn were found to be phytoextracted to the aerial plant biomass, where Cd presented the highest bioconcentration factor values in all treatments. Additionally, the plots where the willows received the S. brunnea inoculation showed a significant decrease of Cu, Pb, and Sn soil concentrations. AM fungi inoculation and dual inoculation did not significantly influence biomass production and soil TE levels.
Revisiting the Charge-Transfer States at Pentacene/C60 Interfaces with the GW/Bethe–Salpeter Equation Approach
Authors: Fujita Takatoshi , Noguchi Yoshifumi , Hoshi Takeo
Published: June 2020

Molecular orientations and interfacial morphologies have critical effects on the electronic states of donor/acceptor interfaces and thus on the performance of organic photovoltaic devices. In this study, we explore the energy levels and charge-transfer states at the organic donor/acceptor interfaces on the basis of the fragment-based GW and Bethe–Salpeter equation approach. The face-on and edge-on orientations of pentacene/C60 bilayer heterojunctions have employed as model systems. GW+Bethe–Salpeter equation calculations were performed for the local interface structures in the face-on and edge-on bilayer heterojunctions, which contain approximately 2000 atoms. Calculated energy levels and charge-transfer state absorption spectra are in reasonable agreements with those obtained from experimental measurements. We found that the dependence of the energy levels on interfacial morphology is predominantly determined by the electrostatic contribution of polarization energy, while the effects of induction contribution in the edge-on interface are similar to those in the face-on. Moreover, the delocalized charge-transfer states contribute to the main absorption peak in the edge-on interface, while the face-on interface features relatively localized charge-transfer states in the main absorption peak. The impact of the interfacial morphologies on the polarization and charge delocalization effects is analyzed in detail.
Surface Characteristics of Machined Polystyrene with 3D Printed Thermoplastic Tool
Authors: Sandhu Kamalpreet , Singh Gurminder , Singh Sunpreet , Kumar Raman , Prakash Chander , Ramakrishna Seeram , Królczyk Grzegorz , Pruncu Catalin I.
Published: June 2020

An effort is made in this work to appraise the surface characteristics of machined expandable polystyrene (EPS) with a novel 3D printed thermoplastic acrylonitrile-butadiene-styrene (ABS) tool. Linear grooves on EPS were made on a vertical milling machine that was modified to conduct experiments in the laboratory. The tests were designed as per the Taguchi L9 based factorial design of experimentation while varying process parameters such as depth of cut, spindle speed, and feed rate. The machining responses dimensional accuracy and surface roughness of the machined grooves were studied. Furthermore, the surface topography of the machined specimens was considered to investigate the mechanism of material removal in response to the processing conditions. Moreover, mathematical models developed for the prediction of the output responses showed a significant correlation with the experimental results. The results of the statistical study indicate that the surface roughness is influenced by the spindle speed and dimensional accuracy by the depth-of-cut. Overall, the findings of the experimental work advocated the feasibility of 3D printed thermoplastic tools for machining soft polymeric materials. It can become a useful alternative for mass and batch production.
Characterization of the Cellular Reaction to a Collagen-Based Matrix: An In Vivo Histological and Histomorphometrical Analysis
Authors: Udeabor Samuel Ebele , Herrera-Vizcaíno Carlos , Sader Robert , Kirkpatrick C. James , Al-Maawi Sarah , Ghanaati Shahram
Published: June 2020

The permeability and inflammatory tissue reaction to Mucomaix® matrix (MM), a non- cross-linked collagen-based matrix was evaluated in both ex vivo and in vivo settings. Liquid platelet rich fibrin (PRF), a blood concentrate system, was used to assess its capacity to absorb human proteins and interact with blood cells ex vivo. In the in vivo aspect, 12 Wister rats had MM implanted subcutaneously, whereas another 12 rats (control) were sham-operated without biomaterial implantation. On days 3, 15 and 30, explantation was completed (four rats per time-point) to evaluate the tissue reactions to the matrix. Data collected were statistically analyzed using analysis of variance (ANOVA) and Tukey multiple comparisons tests (GraphPad Prism 8). The matrix absorbed the liquid PRF in the ex vivo study. Day 3 post-implantation revealed mild tissue inflammatory reaction with presence of mononuclear cells in the implantation site and on the biomaterial surface (mostly CD68-positive macrophages). The control group at this stage had more mononuclear cells than the test group. From day 15, multinucleated giant cells (MNGCs) were seen in the implantation site and the outer third of the matrix with marked increase on day 30 and spread to the matrix core. The presence of these CD68-positive MNGCs was associated with significant matrix vascularization. The matrix degraded significantly over the study period, but its core was still visible as of day 30 post-implantation. The high permeability and fast degradation properties of MM were highlighted.
Soft Materials for Wearable/Flexible Electrochemical Energy Conversion, Storage, and Biosensor Devices
Authors: Bocchetta Patrizia , Frattini Domenico , Ghosh Srabanti , Mohan Allibai Mohanan Vinu , Kumar Yogesh , Kwon Yongchai
Published: June 2020

Next-generation wearable technology needs portable flexible energy storage, conversion, and biosensor devices that can be worn on soft and curved surfaces. The conformal integration of these devices requires the use of soft, flexible, light materials, and substrates with similar mechanical properties as well as high performances. In this review, we have collected and discussed the remarkable research contributions of recent years, focusing the attention on the development and arrangement of soft and flexible materials (electrodes, electrolytes, substrates) that allowed traditional power sources and sensors to become viable and compatible with wearable electronics, preserving or improving their conventional performances.
Molding Binder Influence on the Porosity and Gas Permeability of Ceramic Casting Molds
Authors: Wisniewski Pawel , Sitek Ryszard , Towarek Aleksandra , Choinska Emilia , Moszczynska Dorota , Mizera Jaroslaw
Published: June 2020

The investment casting process is widely used in the aerospace industry to produce complex engine parts. The article determines the properties of quartz powders, nanosilica dioxide binders, and multilayer samples of ceramic casting molds. The properties of spherical molds obtained using an alcohol-water system derived from hydrolyzed ethyl silicate (ZKE) and LUDOX PX-30 (type Q1) were compared with those obtained in water systems derived from Remasol Plus and Remasol Premium binders (type Q2). The spherical samples are composed of seven layers made with the use of an immersion-sprinkling method. To assess the properties of the molds, X-ray microscopy (µCT), scanning electron microscopy (SEM), and gas permeability analysis over a temperature range of 20–950 °C were utilized. The binder type is proven to affect the properties of the casting mold samples. The material obtained in the water system, Q2, has advantageous properties such as a high porosity and gas permeability.
A Study of the Second-Kind Multivariate Pseudo-Chebyshev Functions of Fractional Degree
Authors: Ricci Paolo Emilio , Srivastava Rekha
Published: June 2020

Here, in this paper, the second-kind multivariate pseudo-Chebyshev functions of fractional degree are introduced by using the Dunford–Taylor integral. As an application, the problem of finding matrix roots for a wide class of non-singular complex matrices has been considered. The principal value of the fixed matrix root is determined. In general, by changing the determinations of the numerical roots involved, we could find n r roots for the n-th root of an r × r matrix. The exceptional cases for which there are infinitely many roots, or no roots at all, are obviously excluded.
Unbiased Least-Squares Modelling
Authors: Gatto Marta , Marcuzzi Fabio
Published: June 2020

In this paper we analyze the bias in a general linear least-squares parameter estimation problem, when it is caused by deterministic variables that have not been included in the model. We propose a method to substantially reduce this bias, under the hypothesis that some a-priori information on the magnitude of the modelled and unmodelled components of the model is known. We call this method Unbiased Least-Squares (ULS) parameter estimation and present here its essential properties and some numerical results on an applied example.
Simplified Analytical Solution of the Contact Problem on Indentation of a Coated Half-Space by a Conical Punch
Authors: Vasiliev Andrey S. , Volkov Sergey S. , Sadyrin Evgeniy V. , Aizikovich Sergei M.
Published: June 2020

The contact problem on indentation of an elastic coated half-space by a conical punch is considered. To obtain an explicit analytical solution suitable for applications, the bilateral asymptotic method is used in a simplified form. For that purpose, kernel transform of the integral equation is approximated by a ratio of two quadratic functions containing only one parameter. Such an approach allows us to obtain explicit analytical expressions for the distribution of contact stresses and relations between the indentation force, depth, stiffness and contact radius. The obtained solution is suitable both for homogeneous and functionally graded coatings. The dependence of the characteristics of contact interaction on a relative Young’s modulus of the coating and relative coating thickness is analyzed and illustrated by the numerical examples. Ranges of values of elastic and geometrical parameters are obtained, for which the presence of a coating sufficiently changes the contact characteristics. The accuracy of the obtained simplified expressions is studied in detail. Results of the paper sufficiently simplify engineering calculations and are suitable for inverse analysis, e.g., analysis of indentation experiments of coated materials using either a conical or a pyramidal (Berkovich) indenter.
Nipple–Areola Complex Reconstruction
Authors: Sisti Andrea
Published: June 2020

The reconstruction of the nipple–areola complex is the last step in the breast reconstruction process. Several techniques have been described over the years. The aim of this review is to provide clarity on the currently available reconstructive options.
SteBLife, a New Approach for the Accelerated Generation of Metallic Materials’ Fatigue Data
Authors: Acosta Ruth , Wu Haoran , Sridaran Venkat Ramanan , Weber Fabian , Tenkamp Jochen , Walther Frank , Starke Peter
Published: June 2020

The service life of materials and components exposed to repeated mechanical loads is limited, which is why the understanding of the damage evolution and estimating its fatigue life is of high importance for its technical application. This paper shows how temperature and magnetic field measurement methods can be used to describe the cyclic deformation behaviour of metallic materials and to derive parameters from this, which are used in short-term methods to calculate the fatigue life. Within the SteBLife (stepped-bar fatigue life) approach, only three to five fatigue tests with a stepped fatigue specimen are required to determine a complete S–N or Woehler curve with scatter bands for different failure probabilities. If only a trend S–N curve is required, the number of tests can be reduced to a single fatigue test only. In the framework of this paper, these approaches will be presented for normalised SAE 1045 (C45E) and quenched and tempered SAE 4140 (42CrMo4) steels.
Wear of ZhS6U Nickel Superalloy Tool in Friction Stir Processing on Commercially Pure Titanium
Authors: Amirov Alihan , Eliseev Alexander , Kolubaev Evgeny , Filippov Andrey , Rubtsov Valery
Published: June 2020

The use of electric arc or gas welding in the manufacture of titanium components often results in low quality welded joints due to large residual stresses and strains. A successful solution to this problem can be found in the application of friction stir welding. However, friction stir welding (FSW) of titanium alloys is complicated by rapid tool wear under high loads and temperatures achieved in the process. This paper studies the durability of a tool made of ZhS6U Ni-based superalloy used for friction stir processing of commercially pure titanium and the effect of the tool wear on the weld quality. The total length of the titanium weld formed by the tool without failure comprised 2755 mm. The highest wear of the tool is observed at the base of the pin, which brings about the formation of macrodefects in the processed material. The tool overheating causes an increase in the dendrite element size of ZhS6U alloy. The transfer layer contains chemical elements of this alloy, indicating that the tool wear occurs by diffusion and adhesion. As a result of processing, the tensile strength of commercially pure titanium increased by 25%.
Oxidation Induced Stresses in High-Temperature Oxidation of Steel: A Multiphase Field Study
Authors: Toghraee Alireza , Asle Zaeem Mohsen
Published: June 2020

Oxide growth and the induced stresses in the high-temperature oxidation of steel were studied by a multiphase field model. The model incorporates both chemical and elastic energy to capture the coupled oxide kinetics and generated stresses. Oxidation of a flat surface and a sharp corner are considered at two high temperatures of 850 °C and 1180 °C to investigate the effects of geometry and temperature elevation on the shape evolution of oxides and the induced stresses. Results show that the model is capable of capturing the oxide thickness and its outward growth, comparable to the experiments. In addition, it was shown that there is an interaction between the evolution of oxide and the generated stresses, and the oxide layer evolves to reduce stress concentrations by rounding the sharp corners in the geometry. Increasing the temperature may increase or decrease the stress levels depending on the contribution of eigen strain in the generated elastic strain energy during oxidation.
Changes in Plasma Itaconate Elevation in Early Rheumatoid Arthritis Patients Elucidates Disease Activity Associated Macrophage Activation
Authors: Daly Rónán , Blackburn Gavin , Best Cameron , Goodyear Carl S. , Mudaliar Manikhandan , Burgess Karl , Stirling Anne , Porter Duncan , McInnes Iain B. , Barrett Michael P. , Dale James
Published: June 2020

Changes in the plasma metabolic profile were characterised in newly diagnosed rheumatoid arthritis (RA) patients upon commencement of conventional disease-modifying anti-rheumatic drug (cDMARD) therapy. Plasma samples collected in an early RA randomised strategy study (NCT00920478) that compared clinical (DAS) disease activity assessment with musculoskeletal ultrasound assessment (MSUS) to drive treatment decisions were subjected to untargeted metabolomic analysis. Metabolic profiles were collected at pre- and three months post-commencement of nonbiologic cDMARD. Metabolites that changed in association with changes in the DAS44 score were identified at the three-month timepoint. A total of nine metabolites exhibited a clear correlation with a reduction in DAS44 score following cDMARD commencement, particularly itaconate, its derived anhydride and a derivative of itaconate CoA. Increasing itaconate correlated with improved DAS44 score and decreasing levels of C-reactive protein (CRP). cDMARD treatment effects invoke consistent changes in plasma detectable metabolites, that in turn implicate clinical disease activity with macrophages. Such changes inform RA pathogenesis and reveal for the first time a link between itaconate production and resolution of inflammatory disease in humans. Quantitative metabolic biomarker-based tests of clinical change in state are feasible and should be developed around the itaconate pathway.
Antibiotic-Induced Changes in Microbiome-Related Metabolites and Bile Acids in Rat Plasma
Authors: de Bruijn Véronique , Behr Christina , Sperber Saskia , Walk Tilmann , Ternes Philipp , Slopianka Markus , Haake Volker , Beekmann Karsten , van Ravenzwaay Bennard
Published: June 2020

Various environmental factors can alter the gut microbiome’s composition and functionality, and modulate host health. In this study, the effects of oral and parenteral administration of two poorly bioavailable antibiotics (i.e., vancomycin and streptomycin) on male Wistar Crl/Wi(Han) rats for 28 days were compared to distinguish between microbiome-derived or -associated and systemic changes in the plasma metabolome. The resulting changes in the plasma metabolome were compared to the effects of a third reference compound, roxithromycin, which is readily bioavailable. A community analysis revealed that the oral administration of vancomycin and roxithromycin in particular leads to an altered microbial population. Antibiotic-induced changes depending on the administration routes were observed in plasma metabolite levels. Indole-3-acetic acid (IAA) and hippuric acid (HA) were identified as key metabolites of microbiome modulation, with HA being the most sensitive. Even though large variations in the plasma bile acid pool between and within rats were observed, the change in microbiome community was observed to alter the composition of the bile acid pool, especially by an accumulation of taurine-conjugated primary bile acids. In-depth investigation of the relationship between microbiome variability and their functionality, with emphasis on the bile acid pool, will be necessary to better assess the potential adverseness of environmentally induced microbiome changes.
Machine Learning Applications for Mass Spectrometry-Based Metabolomics
Authors: Liebal Ulf W. , Phan An N. T. , Sudhakar Malvika , Raman Karthik , Blank Lars M.
Published: June 2020

The metabolome of an organism depends on environmental factors and intracellular regulation and provides information about the physiological conditions. Metabolomics helps to understand disease progression in clinical settings or estimate metabolite overproduction for metabolic engineering. The most popular analytical metabolomics platform is mass spectrometry (MS). However, MS metabolome data analysis is complicated, since metabolites interact nonlinearly, and the data structures themselves are complex. Machine learning methods have become immensely popular for statistical analysis due to the inherent nonlinear data representation and the ability to process large and heterogeneous data rapidly. In this review, we address recent developments in using machine learning for processing MS spectra and show how machine learning generates new biological insights. In particular, supervised machine learning has great potential in metabolomics research because of the ability to supply quantitative predictions. We review here commonly used tools, such as random forest, support vector machines, artificial neural networks, and genetic algorithms. During processing steps, the supervised machine learning methods help peak picking, normalization, and missing data imputation. For knowledge-driven analysis, machine learning contributes to biomarker detection, classification and regression, biochemical pathway identification, and carbon flux determination. Of important relevance is the combination of different omics data to identify the contributions of the various regulatory levels. Our overview of the recent publications also highlights that data quality determines analysis quality, but also adds to the challenge of choosing the right model for the data. Machine learning methods applied to MS-based metabolomics ease data analysis and can support clinical decisions, guide metabolic engineering, and stimulate fundamental biological discoveries.