bluuebunny/crossref_metadata_2025 huggingface dataset:
Whole-Genome-Based Survey for Polyphyletic Serovars of Salmonella enterica subsp. enterica Provides New Insights into Public Health Surveillance
Authors: Yin Zhiqiu , Liu Jiaheng , Du Binghai , Ruan Hai-Hua , Huo Yi-Xin , Du Yuhui , Qiao Jianjun
Published: July 2020

Serotyping has traditionally been considered the basis for surveillance of Salmonella, but it cannot distinguish distinct lineages sharing the same serovar that vary in host range, pathogenicity and epidemiology. However, polyphyletic serovars have not been extensively investigated. Public health microbiology is currently being transformed by whole-genome sequencing (WGS) data, which promote the lineage determination using a more powerful and accurate technique than serotyping. The focus in this study is to survey and analyze putative polyphyletic serovars. The multi-locus sequence typing (MLST) phylogenetic analysis identified four putative polyphyletic serovars, namely, Montevideo, Bareilly, Saintpaul, and Muenchen. Whole-genome-based phylogeny and population structure highlighted the polyphyletic nature of Bareilly and Saintpaul and the multi-lineage nature of Montevideo and Muenchen. The population of these serovars was defined by extensive genetic diversity, the open pan genome and the small core genome. Source niche metadata revealed putative existence of lineage-specific niche adaptation (host-preference and environmental-preference), exhibited by lineage-specific genomic contents associated with metabolism and transport. Meanwhile, differences in genetic profiles relating to virulence and antimicrobial resistance within each lineage may contribute to pathogenicity and epidemiology. The results also showed that recombination events occurring at the H1-antigen loci may be an important reason for polyphyly. The results presented here provide the genomic basis of simple, rapid, and accurate identification of phylogenetic lineages of these serovars, which could have important implications for public health.
PD-L1 Expression and a High Tumor Infiltrate of CD8+ Lymphocytes Predict Outcome in Patients with Oropharyngeal Squamous Cells Carcinoma
Authors: Wuerdemann Nora , Gültekin Sibel E. , Pütz Katharina , Wittekindt Claus , Huebbers Christian U. , Sharma Shachi J. , Eckel Hans , Schubotz Anna B. , Gattenlöhner Stefan , Büttner Reinhard , Speel Ernst-Jan , Klussmann Jens P. , Wagner Steffen , Quaas Alexander
Published: July 2020

Carcinogenesis of human papillomavirus (HPV)-related (+) oropharyngeal squamous cell carcinoma (OPSCC) differs from HPV-negative (–) OPSCC. HPV-related immune-escape-mechanism could be responsible for the development and progression of HPV+ tumors and an immunophenotype different from HPV– OPSCC is expected. The purpose of this study was to analyze the expression of programmed cell death protein 1 ligand 1 (PD-L1) and its prognostic relevance in relation to CD8+ tumor infiltrating lymphocytes (TILs) and the major histocompatibility complex (MHC) I expression in OPSCC. We quantified PD-L1 expression on tumor cells (TC) and macrophages and MHC I expression in association to CD8+ TILs by immunohistochemistry on tissue microarray derived from 171 HPV+/-OPSCC. HPV-status was determined by p16INK4a immunohistochemistry/HPV-DNA detection. Presence of CD8+ TILs, PD-L1 expression on TC, and a more frequent loss of MHC I in HPV+ compared to HPV- OPSCC was detected. A high amount of CD8+ TILs in the whole cohort and in HPV+ OPSCC and PD-L1 expression on TC in HPV- OPSCC was associated with favorable overall survival. There was a trend for an improved outcome according to PD-L1 expression (macrophages) in HPV+ OPSCC without reaching statistical significance. CD8+ TILs and PD-L1-expression have prognostic impact in OPSCC and might present useful biomarkers for predicting clinical outcome and personalized therapy concepts.
Immune Cell Therapies to Improve Regeneration and Revascularization of Non-Healing Wounds
Authors: Groppa Elena , Colliva Andrea , Vuerich Roman , Kocijan Tea , Zacchigna Serena
Published: July 2020

With the increased prevalence of chronic diseases, non-healing wounds place a significant burden on the health system and the quality of life of affected patients. Non-healing wounds are full-thickness skin lesions that persist for months or years. While several factors contribute to their pathogenesis, all non-healing wounds consistently demonstrate inadequate vascularization, resulting in the poor supply of oxygen, nutrients, and growth factors at the level of the lesion. Most existing therapies rely on the use of dermal substitutes, which help the re-epithelialization of the lesion by mimicking a pro-regenerative extracellular matrix. However, in most patients, this approach is not efficient, as non-healing wounds principally affect individuals afflicted with vascular disorders, such as peripheral artery disease and/or diabetes. Over the last 25 years, innovative therapies have been proposed with the aim of fostering the regenerative potential of multiple immune cell types. This can be achieved by promoting cell mobilization into the circulation, their recruitment to the wound site, modulation of their local activity, or their direct injection into the wound. In this review, we summarize preclinical and clinical studies that have explored the potential of various populations of immune cells to promote skin regeneration in non-healing wounds and critically discuss the current limitations that prevent the adoption of these therapies in the clinics.
Analysis of the Awareness and Popularity of the Brand of a Selected Education and Research Library in the Czech Republic: A Case Study
Authors: Hommerová Dita , Šrédl Karel , Dbalá Kristýna
Published: July 2020

This article aims to show the significance of branding in achieving set marketing goals and ensuring the sustainable development of a selected education and research library as a non-profit organization. The research is based on available data from foreign research studies concerning the image of a brand and the branding of non-profit organizations, and it expands on them by utilizing other methods of brand image measurement. A survey involving a sample of 220 respondents was conducted at the particular site, taking into account the library’s target segments. An analysis of the awareness and favorability of its brand was also utilized to evaluate the library’s image. The library has recently undergone a rebranding process and is applying a new visual style. The new visual style of the library resulting from the rebranding was met with a positive response in 69% of cases. Branding and appropriate marketing communication that reflects the latest trends can have a positive influence on the sustainability of libraries. The research results have contributed to the adoption of corrective measures in planning the strategy of the selected library, and the case study results can be applied across the board to other contributory organizations in the Czech Republic.
Insights from Population Genomics to Enhance and Sustain Biological Control of Insect Pests
Authors: Sethuraman Arun , Janzen Fredric J. , Weisrock David W. , Obrycki John J.
Published: July 2020

Biological control—the use of organisms (e.g., nematodes, arthropods, bacteria, fungi, viruses) for the suppression of insect pest species—is a well-established, ecologically sound and economically profitable tactic for crop protection. This approach has served as a sustainable solution for many insect pest problems for over a century in North America. However, all pest management tactics have associated risks. Specifically, the ecological non-target effects of biological control have been examined in numerous systems. In contrast, the need to understand the short- and long-term evolutionary consequences of human-mediated manipulation of biological control organisms for importation, augmentation and conservation biological control has only recently been acknowledged. Particularly, population genomics presents exceptional opportunities to study adaptive evolution and invasiveness of pests and biological control organisms. Population genomics also provides insights into (1) long-term biological consequences of releases, (2) the ecological success and sustainability of this pest management tactic and (3) non-target effects on native species, populations and ecosystems. Recent advances in genomic sequencing technology and model-based statistical methods to analyze population-scale genomic data provide a much needed impetus for biological control programs to benefit by incorporating a consideration of evolutionary consequences. Here, we review current technology and methods in population genomics and their applications to biological control and include basic guidelines for biological control researchers for implementing genomic technology and statistical modeling.
Phthalates Implications in the Cardiovascular System
Authors: Mariana Melissa , Cairrao Elisa
Published: July 2020

Today’s sedentary lifestyle and eating habits have been implicated as some of the causes of the increased incidence of several diseases, including cancer and cardiovascular diseases. However, environmental pollutants have also been identified as another possible cause for this increase in recent decades. The constant human exposure to plastics has been raising attention regarding human health, particularly when it comes to phthalates. These are plasticizers used in the manufacture of industrial and consumer products, such as PVC (Polyvinyl Chloride) plastics and personal care products, with endocrine-disrupting properties, as they can bind molecular targets in the body and interfere with hormonal function. Since these compounds are not covalently bound to the plastic, they are easily released into the environment during their manufacture, use, or disposal, leading to increased human exposure and enhancing health risks. In fact, some studies have related phthalate exposure with cardiovascular health, having already shown a positive association with the development of hypertension and atherosclerosis in adults and some cardiometabolic risk factors in children and adolescents. Therefore, the main purpose of this review is to present and relate the most recent studies concerning the implications of phthalates effects on the cardiovascular system.
Selecting Appropriate Sarcopenia Screening Methods for Asian Populations
Authors: Lin Yu-Ching , Lu Yi-Chien , Chen Fang-Ping , Lin Ying Chin , Cheung Yun-Chung , Chan Wing P.
Published: July 2020

We aimed to determine the most appropriate sarcopenia screening method for Asian populations. We retrospectively studied the physiological differences between the sexes in healthy individuals and prospectively compared using skeletal muscle mass versus handgrip strength (HS) to screen for sarcopenia in a community-based population. Skeletal muscle mass was determined using dual-energy X-ray absorptiometry. Of 5881 healthy individuals recruited, 101 were from urban populations and 349 from a community-based population. The sexes were comparable in total lean muscle mass declines after peaking around 20 years of age. An age-dependent decline in total fat mass was found only among men;a persistent increase in total fat mass was observed only among women. The prevalence of low skeletal muscle mass significantly increased with age in both sexes only when applying the weight-adjusted skeletal muscle index (wSMI); it was significant only among men when applying the height-adjusted skeletal muscle index (hSMI). Using HS resulted in a much higher prevalence of sarcopenia in both sexes. A significant age-dependent increase in fat mass in women showed that the most appropriate adjustment method is wSMI for women and hSMI for men. Nevertheless, a primary HS survey is recommended for both sexes in Asian populations.
The Role of Inflammation and Inflammasome in Myeloproliferative Disease
Authors: Longhitano Lucia , Li Volti Giovanni , Giallongo Cesarina , Spampinato Mariarita , Barbagallo Ignazio , Di Rosa Michelino , Romano Alessandra , Avola Roberto , Tibullo Daniele , Palumbo Giuseppe Alberto
Published: July 2020

Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are rare hematological conditions known as myeloproliferative neoplasms (MPNs). They are characterized for being BCR-ABL negative malignancies and affected patients often present with symptoms which can significantly impact their quality of life. MPNs are characterized by a clonal proliferation of an abnormal hematopoietic stem/progenitor cell. In MPNs; cells of all myeloid lineages; including those involved in the immune and inflammatory response; may belong to the malignant clone thus leading to an altered immune response and an overexpression of cytokines and inflammatory receptors; further worsening chronic inflammation. Many of these cytokines; in particular, IL-1β and IL-18; are released in active form by activating the inflammasome complexes which in turn mediate the inflammatory process. Despite this; little is known about the functional effects of stem cell-driven inflammasome signaling in MPN pathogenesis. In this review we focused on the role of inflammatory pathway and inflammasome in MPN diseases. A better understanding of the inflammatory-state-driving MPNs and of the role of the inflammasome may provide new insights on possible therapeutic strategies
Clinical Features Associated with Female Genital Mutilation/Cutting: A Pilot Longitudinal Study
Authors: Paslakis Georgios , Farré Josep M. , Tolosa-Sola Iris , Palazón-Llecha Alba , Domínguez-Cagnon Helena , Jiménez Maria , Martínez Rosselló Berta , Barri-Soldevila Pere , Mestre-Bach Gemma
Published: July 2020

(1) Background: Female genital mutilation/cutting (FGM/C) is associated with physical and psychological complications. However, there is scarce literature on how women with FGM/C respond to treatment interventions. (2) Methods: In the present pilot longitudinal study, we assessed changes in general psychopathology (Symptom Check List-90-R), sexual functioning and distress (Female Sexual Function Index, Female Sexual Distress Scale-Revised, and Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) female sexual dysfunction criteria), body image (Body Shape Questionnaire), and sexual body image (Female Genital Self-Image Scale) in a sample of n = 15 women with FGM/C before and after reconstructive surgery. (3) Results: Sexual distress was significantly improved following surgery. We also observed an improvement in general psychopathology and genital self-image. However, sexual function was not improved. (4) Conclusions: These results provide evidence for the benefits of reconstructive surgery on sexual distress in women with FGM/C. The impact of surgery on sexual function cannot be conclusively evaluated.
In Vitro Assessment of Fluoropyrimidine-Metabolizing Enzymes: Dihydropyrimidine Dehydrogenase, Dihydropyrimidinase, and β-Ureidopropionase
Authors: Hishinuma Eiji , Gutiérrez Rico Evelyn , Hiratsuka Masahiro
Published: July 2020

Fluoropyrimidine drugs (FPs), including 5-fluorouracil, tegafur, capecitabine, and doxifluridine, are among the most widely used anticancer agents in the treatment of solid tumors. However, severe toxicity occurs in approximately 30% of patients following FP administration, emphasizing the importance of predicting the risk of acute toxicity before treatment. Three metabolic enzymes, dihydropyrimidine dehydrogenase (DPD), dihydropyrimidinase (DHP), and β-ureidopropionase (β-UP), degrade FPs; hence, deficiencies in these enzymes, arising from genetic polymorphisms, are involved in severe FP-related toxicity, although the effect of these polymorphisms on in vivo enzymatic activity has not been clarified. Furthermore, the clinical usefulness of current methods for predicting in vivo activity, such as pyrimidine concentrations in blood or urine, is unknown. In vitro tests have been established as advantageous for predicting the in vivo activity of enzyme variants. This is due to several studies that evaluated FP activities after enzyme metabolism using transient expression systems in Escherichia coli or mammalian cells; however, there are no comparative reports of these results. Thus, in this review, we summarized the results of in vitro analyses involving DPD, DHP, and β-UP in an attempt to encourage further comparative studies using these drug types and to aid in the elucidation of their underlying mechanisms.
Evaluation of Obesity Management Recorded in Electronic Clinical History: A Cohort Study
Authors: Trujillo-Garrido Nuria , Bernal-Jiménez María Ángeles , Santi-Cano María J.
Published: July 2020

Background: The prevalence of obesity is increasing worldwide. Because of their close proximity to the population, primary care physicians and nurses are in a unique position to motivate and advise patients with obesity on a healthy diet and increased physical activity. Drawing from information recorded in electronic clinical records, we evaluated how the general recommendations included in obesity guidelines are being implemented in routine clinical practice. Methods: This study drew from the following data from a cohort of 209 patients with obesity that attended primary care consultations: electronic clinical records, body mass index (BMI), waist circumference (WC), cardiovascular risk factors, comorbidities and whether their health professional documented compliance with the recommendations of the evidence-based obesity guidelines in their electronic history. Results: Only 25.4% of the clinical records met all the criteria established in the therapeutic guidelines regarding diet prescription, 1.4% for physical activity and 1.5% for behavioral change activities. The patients whose records mentioned diet prescription and physical activity and who received follow-up consultations for both factors had lower average BMI and WC, although this relationship was not significant after adjusting for baseline. Conclusions: We found that only a small number of records in the electronic clinical histories followed the evidence-based obesity guidelines. Recording dietetic prescription and physical exercise in the patient’s clinical record is associated with better control of obesity.
Amino Acid Metabolites and Slow Weight Loss in the Early Postoperative Period after Sleeve Gastrectomy
Authors: Kwon Yeongkeun , Jang Mi , Lee Youngsun , Ha Jane , Park Sungsoo
Published: July 2020

Background: Profiles of amino acid metabolites (AAMs) have been linked to obesity and energy homeostasis. We investigated whether baseline obesity-related AAMs were associated with weight status in the early postoperative period after sleeve gastrectomy. Methods: In this prospective, single-arm, longitudinal study, 27 bariatric patients underwent sleeve gastrectomy. Twenty obesity-related AAMs were comprehensively quantified prior to surgery, and slow weight loss was defined as the lowest 40% of the percentage excess weight loss (%EWL) at three and six months postoperatively. Linear regression models were used to assess the association between baseline obesity-related AAMs and %EWL, and receiver operating characteristic curves were assessed. Results: Isoleucine and metabolites from the serotonin pathway were significantly associated with the %EWL at three and six months after sleeve gastrectomy. Among the metabolites identified to be significant in the regression analyses, serotonin (area under receiver operating characteristic curves (AUROC): 0.79, 95% confidence interval (CI): 0.59–0.97) and serotonin/5-hydroxytryptophan ratio (AUROC: 0.80, 95% CI: 0.58–1.00) showed superior performance in predicting slow weight loss six months after sleeve gastrectomy. Conclusions: Our findings underscore the importance of baseline AAM profiles, especially serotonin and serotonin/5-hydroxytryptophan ratio, in predicting slow weight loss in the early postoperative period after sleeve gastrectomy.
Prevention and Management of CMV Infections after Liver Transplantation: Current Practice in German Transplant Centers
Authors: Engelmann Cornelius , Sterneck Martina , Weiss Karl Heinz , Templin Silke , Zopf Steffen , Denk Gerald , Eurich Dennis , Pratschke Johann , Weiss Johannes , Braun Felix , Welker Martin-Walter , Zimmermann Tim , Knipper Petra , Nierhoff Dirk , Lorf Thomas , Jäckel Elmar , Hau Hans-Michael , Tsui Tung Yu , Perrakis Aristoteles , Schlitt Hans-Jürgen , Herzer Kerstin , Tacke Frank
Published: July 2020

Human cytomegalovirus (CMV) remains a major cause of mortality and morbidity in human liver transplant recipients. Anti-CMV therapeutics can be used to prevent or treat CMV in liver transplant recipients, but their toxicity needs to be balanced against the benefits. The choice of prevention strategy (prophylaxis or preemptive treatment) depends on the donor/recipient sero-status but may vary between institutions. We conducted a series of consultations and roundtable discussions with German liver transplant center representatives. Based on 20 out of 22 centers, we herein summarize the current approaches to CMV prevention and treatment in the context of liver transplantation in Germany. In 90% of centers, transient prophylaxis with ganciclovir or valganciclovir was standard of care in high-risk (donor CMV positive, recipient CMV naive) settings, while preemptive therapy (based on CMV viremia detected during (bi) weekly PCR testing for circulating CMV-DNA) was preferred in moderate- and low-risk settings. Duration of prophylaxis or intense surveillance was 3–6 months. In the case of CMV infection, immunosuppression was adapted. In most centers, antiviral treatment was initiated based on PCR results (median threshold value of 1000 copies/mL) with or without symptoms. Therefore, German transplant centers report similar approaches to the prevention and management of CMV infection in liver transplantation.
Reduced Recovery Capacity After Major Trauma in the Elderly: Results of a Prospective Multicenter Registry-Based Cohort Study
Authors: Freigang Viola , Müller Karolina , Ernstberger Antonio , Kaltenstadler Marlene , Bode Lisa , Pfeifer Christian , Alt Volker , Baumann Florian
Published: July 2020

Aims: Considering the worldwide trend of an increased lifetime, geriatric trauma is moving into focus. Trauma is a leading cause of hospitalization, leading to disability and mortality. The purpose of this study was to compare the global health-related quality of life (HRQoL) of geriatric patients with adult patients after major trauma. Methods: This multicenter prospective registry-based observational study compares HRQoL of patients aged ≥65 years who sustained major trauma (Injury Severity Score (ISS) ≥ 16) with patients <65 years of age within the trauma registry of the German Trauma Society (DGU). The global HRQoL was measured at 6, 12, and 24 months post trauma using the EQ-5D-3L score. Results: We identified 405 patients meeting the inclusion criteria with a mean ISS of 25.6. Even though the geriatric patients group (≥65 years, n = 77) had a lower ISS (m = 24, SD = 8) than patients aged <65 years (n = 328), they reported more difficulties in each EQ dimension compared to patients <65 years. Contrary to patients < 65, the EQ-5D Index of the geriatric patients did not improve at 12 and 24 months after trauma. Conclusions: We found a limited HRQoL in both groups after major trauma. The group of patients ≥65 showed no improvement in HRQoL from 6 to 24 months after trauma.
Brain Stimulation in Eating Disorders: State of the Art and Future Perspectives
Authors: Duriez Philibert , Bou Khalil Rami , Chamoun Yara , Maatoug Redwan , Strumila Robertas , Seneque Maude , Gorwood Philip , Courtet Philippe , Guillaume Sébastien
Published: July 2020

The management of eating disorders (EDs) is still difficult and few treatments are effective. Recently, several studies have described the important contribution of non-invasive brain stimulation (repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and electroconvulsive therapy) and invasive brain stimulation (deep brain stimulation and vagal nerve stimulation) for ED management. This review summarizes the available evidence supporting the use of brain stimulation in ED. All published studies on brain stimulation in ED as well as ongoing trials registered at clinicaltrials.gov were examined. Articles on neuromodulation research and perspective articles were also included. This analysis indicates that brain stimulation in EDs is still in its infancy. Literature data consist mainly of case reports, cases series, open studies, and only a few randomized controlled trials. Consequently, the evidence supporting the use of brain stimulation in EDs remains weak. Finally, this review discusses future directions in this research domain (e.g., sites of modulation, how to enhance neuromodulation efficacy, personalized protocols).
Validity and Reliability of a Photoelectric Cells System for the Evaluation of Change of Direction and Lateral Jumping Abilities in Collegiate Basketball Athletes
Authors: Condello Giancarlo , Khemtong Chutimon , Lee Yi-Hua , Chen Chi-Hsien , Mandorino Mauro , Santoro Enrico , Liu Chiang , Tessitore Antonio
Published: July 2020

The validity and reliability of the Optojump system were investigated for jumping height and flight time in vertical jump tests. Conversely, the purpose of the present study was to investigate the validity and reliability of the Optojump system for measuring contact time and lateral displacement in change of direction and lateral jump tests. Thirty basketball collegiate athletes were tested on two 10 m sprints with a 60° (COD60) or 180° (COD180) change of direction, lateral controlled (CLRJ) and maximal (MLRJ) rebound jump, and lateral countermovement (LCMJ) and squat (LSJ) jump with the concomitant use of two force plates and the Optojump system for the measurement of contact time in COD60, COD180, CLRJ, MLRJ, and lateral jumping distance in all the lateral jump tests. Almost perfect coefficients (r ≥ 0.95) emerged for contact time in COD60, COD180, CLRJ, MLRJ, although a systematic bias was found for COD60 (−0.01 s). Good-to-excellent reliability was found for almost all the measurements of contact time and lateral jumping distance for change of direction and lateral jump tests. Therefore, the use of Optojump system for testing change of direction and lateral jumping abilities should be executed with caution, avoiding misinterpretation of data.
Reconstructing the Ancient Route Network in Pergamon’s Surroundings
Authors: Ludwig Bernhard
Published: July 2020

The surrounding landscape of ancient Pergamon is characterized by several mountain ranges, the Bakırçay Valley and River and the Aegean coastline. The accessibility of this region was vital for the city since it provided food and resources as well as trade, communication and military movements, all facilitated by a well-developed route network. Despite the importance of roads for the development and prosperity of the city, the ancient route network is still widely unexplored and archeological evidence of roads is extremely rare. This study therefore aims to reconstruct the ancient route network in the surroundings of Pergamon by combining historical and archeological sources with modern computer-aided least-cost path analyses, while also considering changes in the landscape that have occurred since antiquity. Based on these detailed results, conclusions may be drawn about the characteristics and functional diversity of the routes. Although the investigation of the route network in the surroundings of Pergamon cannot be considered complete, the results of this study already offer a valuable basis for further research, analyses, modeling and field work.
Electrophoretic Co-deposition of Polyetheretherketone and Graphite Particles: Microstructure, Electrochemical Corrosion Resistance, and Coating Adhesion to a Titanium Alloy
Authors: Fiołek Aleksandra , Zimowski Sławomir , Kopia Agnieszka , Łukaszczyk Alicja , Moskalewicz Tomasz
Published: July 2020

The present study explores the possibilities of fabricating a graphite/polyetheretherketone (PEEK) composite coating on a Ti-6Al-4V titanium alloy through duplex treatment consisting of electrophoretic deposition (EPD) and heat treatment. It has been found that the electrophoretic co-deposition of graphite and PEEK microparticles can be performed from environmentally-friendly pure ethanolic suspensions. Zeta potential measurements and a study of the interaction between both particle types with the use of transmission electron microscopy allowed potential mechanisms of particle co-deposition to be indicated. Microstructure characterization was performed on macro-, micro- and nanoscale using visible light microscopy, X-ray diffractometry and electron microscopy. This allowed the coating homogeneity and distribution of graphite particles in the polymer matrix to be described. Graphite particles in the form of graphene nanosheet packages were relatively evenly distributed in the coating matrix and oriented parallel to the coating surface. The heat-treated coatings showed high scratch resistance and no adhesive type destruction was observed, but they were highly susceptible to deformation. The corrosion measurements were performed with use of electrochemical techniques like open circuit potential and linear sweep voltamperometry. The coated alloy indicated better electrochemical corrosion resistance compared with the uncoated alloy. This work showed the high versatility of the electrophoretic co-deposition of graphite and PEEK particles, which combined with post-EPD heat treatment allows composite coatings to be fabricated with controlled distribution of graphite particles.
Realization of Deep UV Plasmonic Enhancement to Photo Response through Al Mesh
Authors: Li Gaoming , Zhang Jingwen , Hu Yaoting , He Yongning
Published: July 2020

High-performance UV detectors are of great significance for various applications. Plasmonic structures enable great improvement of the performance of detectors. However, to push the plasmonic enhancement to photo response into the deep-UV region presents some challenges. In this work, we found that the optical properties of the supporting layer play important roles in achieving the optimal plasmonic enhancement. Therefore, we fully considered the dependence of the optical constants of the MgZnO supporting layer, which is a promising material to realize deep-UV photodetectors, on microstructure and crystalline quality, which are related to the fabrication method. Based on the optical constants, we designed an Al mesh plasmonic structure and fabricated it with a polystyrene monolayer as a mask. Finally, we demonstrated a three-times enhancement to photo response with UV radiation at 254 nm.
Influence of Hydrodynamic Conditions on the Type and Area of Occurrence of Gas–Liquid Flow Patterns in the Flow through Open–Cell Foams
Authors: Dyga Roman , Płaczek Małgorzata
Published: July 2020

This paper reports the results of a study concerned with air−water and air−oil two–phase flow pattern analysis in the channels with open–cell metal foams. The research was conducted in a horizontal channel with an internal diameter of 0.02 m and length of 2.61 m. The analysis applied three foams with pore density equal to 20, 30 and 40 PPI (pore per inch) with porosity, typical for industrial applications, changing in the range of 92%–94%. Plug flow, slug flow, stratified flow and annular flow were observed over the ranges of gas and liquid superficial velocities of 0.031–8.840 m/s and 0.006–0.119 m/s, respectively. Churn flow, which has not yet been observed in the flow through the open–cell foams, was also recorded. The type of flow patterns is primarily affected by the hydrodynamic characteristics of the flow, including fluid properties, but not by the geometric parameters of foams. Flow patterns in the channels packed with metal foams occur in different conditions from the ones recorded for empty channels so gas−liquid flow maps developed for empty channels cannot be used to predict analyzed flows. A new gas−liquid flow pattern map for a channel packed with metal foams with the porosity of 0.92–0.94 was developed. The map is valid for liquids with a density equal to or lower than the density of water and a viscosity several times greater than that of water.
Chiral Optical Tamm States at the Interface between a Dye-Doped Cholesteric Liquid Crystal and an Anisotropic Mirror
Authors: Avdeeva Anastasia Yu. , Vetrov Stepan Ya. , Bikbaev Rashid G. , Pyatnov Maxim V. , Rudakova Natalya V. , Timofeev Ivan V.
Published: July 2020

The resonant splitting of optical Tamm state numerically is demonstrated. The Tamm state is localized at the interface between a resonant chiral medium and a polarization-preserving anisotropic mirror. The chiral medium is considered as a cholesteric liquid crystal doped with resonant dye molecules. The article shows that the splitting occurs when dye resonance frequency coincides with the frequency of the Tamm state. In this case the reflectance, transmittance, and absorptance spectra show two distinct Tamm modes. For both modes, the field localization is at the interface between the media. The external field control of configurable optical and structural parameters paves the way for use in tunable chiral microlaser.
Assessing the Mechanical Weakness of Vertebrae Affected by Primary Tumors: A Feasibility Study
Authors: Palanca Marco , Cristofolini Luca , Gasbarrini Alessandro , Tedesco Giuseppe , Barbanti-Bròdano Giovanni
Published: July 2020

Patients spend months between the primary spinal tumor diagnosis and the surgical treatment, due to the need for performing chemotherapy and/or radiotherapy. During this period, they are exposed to an unknown risk of fracture. The aim of this study was to assess if it is possible to measure the mechanical strain in vertebrae affected by primary tumors, so as to open the way to an evidence-based scoring or prediction tool. We performed biomechanical tests on three vertebrae with bone tumor removed from patients. The tests were designed so as not to compromise the standard surgical and diagnostic procedures. Non-destructive mechanical tests in combination with state-of-the-art digital image correlation allowed to measure the distribution of strain on the surface of the vertebra. Our study has shown that the strains in the tumor region is circa 3 times higher than in the healthy bones, with principal strain peaks of 40,000/−20,000 microstrain, indicating a stress concentration potentially triggering vertebral fracture. This study has proven it is possible to analyze the mechanical behavior of primary tumor vertebrae as part of the clinical treatment protocol. This will allow building a tool for quantifying the risk of fracture and improving decision making in spine tumors.
Crack Growth Behavior of Additively Manufactured 316L Steel—Influence of Build Orientation and Heat Treatment
Authors: Kluczyński Janusz , Śnieżek Lucjan , Grzelak Krzysztof , Torzewski Janusz , Szachogłuchowicz Ireneusz , Wachowski Marcin , Łuszczek Jakub
Published: July 2020

The effects of build orientation and heat treatment on the crack growth behavior of 316L stainless steel (SS) fabricated via a selective laser melting additive manufacturing process were investigated. Available research results on additively manufactured metallic parts still require a substantial expansion. The most important issue connected with the metal properties after additive manufacturing are the high anisotropy properties, especially from the fatigue point of view. The study examined the crack growth behavior of additively manufactured 316L in comparison to a conventionally made reference material. Both groups of samples were obtained using precipitation heat treatment. Different build orientations in the additively manufactured samples and rolling direction in the reference samples were taken into account as well. Precipitation heat treatment of additively manufactured parts allowed one to achieve microstructure and tensile properties to similar to those of conventionally made pieces. The heat treatment positively affected the fatigue properties. Additionally, precipitation heat treatment of additively manufactured elements significantly affected the reduction of fatigue cracking velocity and changed the fatigue cracking mechanism.
Effects of Plastic Waste on the Heat-Induced Spalling Performance and Mechanical Properties of High Strength Concrete
Authors: Rohden Abrahão Bernardo , Camilo Jessica Regina , Amaral Rafaela Cristina , Garcez Estela Oliari , Garcez Mônica Regina
Published: July 2020

This paper investigates a potential application of hard-to-recycle plastic waste as polymeric addition in high strength concrete, with a focus on the potential to mitigate heat-induced concrete spalling and the consequent effects on the mechanical properties. The waste corresponds to soft and hard plastic, including household polymers vastly disposed of in landfills, although technically recyclable. Mechanical and physical properties, cracking, mass loss, and the occurrence of spalling were assessed in high strength concrete samples produced with either plastic waste or polypropylene fibers after 2-h exposure to 600 °C. The analysis was supported by Scanning Electron Microscopy and X-Ray Computed Tomography images. The plastic waste is composed of different polymers with a thermal degradation between 250 to 500 °C. Polypropylene (PP) fibers and plastic waste dispersed in concrete have proved to play an essential role in mitigating heat-induced concrete spalling, contributing to the release of internal pressure after the polymer melting. The different morphology of plastic waste and polypropylene fibers leads to distinct mechanisms of action. While the vapor pressure dissipation network originated by polypropylene fibers is related to the formation of continuous channels, the plastic waste seems to cause discontinuous reservoirs and fewer damages into the concrete matrix. The incorporation of plastic waste improved heat-induced concrete spalling performance. While 6 kg/m3 of plastic increased the mechanical performance after exposure to high temperature, the incorporation of 3 kg/m3 resulted in mechanical properties comparable to the reference concrete.
Study on the Interface Constitutive Relation between Carbon Fiber Fabric and Steel
Authors: Shi Jianjun , Jia Bin , Ren Yinyin , Zhang Xiaomei , Luo Jian
Published: July 2020

Peeling failure at the interface is one of the main failure modes for CFRP (Carbon Fiber-Reinforced Polymer)-reinforced steel structures. However, there are very few reported studies on the bond-slip relationship at the CFRP-steel interface. A series of simple shear tests were carried out in the present paper. The influence of the fiber fabric’s width and thickness, the surface roughness of the steel sheet, and the thickness of the adhesive layer on the bonding performance of the CFRP fabric to steel interface was considered. The interface constitutive model and bonding strength model were further established under multiple factors. The results show that with the decrease of the surface roughness, the interface’ ultimate peeling load increases gradually, and the failure has a tendency to develop from a glue-steel interface to a glue-CFRP interface. The test pieces that were subjected to sand blasting obtained the peak value of the ultimate peeling load. This indicates that sand blasting can effectively enhance the interface bonding strength. The theoretical values obtained via the interface prediction model are consistent with the experimental values. This proves that the newly developed interface prediction model can effectively predict the local bonding slip and bonding strength of the interface.
Analysis of Environmental Factors Affecting the Atmospheric Corrosion Rate of Low-Alloy Steel Using Random Forest-Based Models
Authors: Yan Luchun , Diao Yupeng , Gao Kewei
Published: July 2020

As one of the factors (e.g., material properties, surface quality, etc.) influencing the corrosion processes, researchers have always been exploring the role of environmental factors to understand the mechanism of atmospheric corrosion. This study proposes a random forest algorithm-based modeling method that successfully maps both the steel’s chemical composition and environmental factors to the corrosion rate of low-alloy steel under the corresponding environmental conditions. Using the random forest models based on the corrosion data of three different atmospheric environments, the environmental factors were proved to have different importance sequence in determining the environmental corrosivity of open and sheltered exposure test conditions. For each exposure test site, the importance of environmental features to the corrosion rate is also ranked and analyzed. Additionally, the feasibility of the random forest model to predict the corrosion rate of steel samples in the new environment is also demonstrated. The volume and representativeness of the corrosion data in the training data are considered to be the critical factors in determining its prediction performance. The above results prove that machine learning provides a useful tool for the analysis of atmospheric corrosion mechanisms and the evaluation of corrosion resistance.
Crosslinking Dynamics and Gelation Characteristics of Photo- and Thermally Polymerized Poly(Ethylene Glycol) Hydrogels
Authors: Sung Jungmoon , Lee Dong Geun , Lee Sukchin , Park Junyoung , Jung Hyun Wook
Published: July 2020

The crosslinking behaviors and gelation features of poly(ethylene glycol) (PEG) hydrogels were scrutinized during the UV and thermal polymerizations of mixtures of poly(ethylene glycol) methacrylate (PEGMA, monomer) and poly(ethylene glycol) dimethacrylates (PEGDMAs, crosslinkers). The real-time crosslinking behavior of the PEG hydrogels was quantified as a function of the UV irradiation time and reaction temperature during the UV and thermal polymerization, respectively, using real-time FT-IR spectrometry and rotational rheometry. The gelation characteristics of UV- and thermally crosslinked hydrogels were compared through the analysis of the gel fraction, swelling ratio, surface hardness, and the loading and release of rhodamine-B. The gelation properties of the cured hydrogel films were suitably correlated with the real-time rheological properties and crosslinked network state of the PEG mixtures. The crosslinking and gelation properties of the cured hydrogels could be optimally tuned by not only the molecular weight of the crosslinker but also the UV or thermal polymerization conditions.
Non-Linear Conductivity Epoxy/SiC Composites for Emerging Power Module Packaging: Fabrication, Characterization and Application
Authors: Li Rui , Wang Yufan , Zhang Cheng , Liang Hucheng , Li Jin , Du Boxue
Published: July 2020

In this paper, SiC/epoxy resin composites containing different amounts of micro-sized SiC with different crystal morphologies were fabricated to study the effects of crystal morphology and temperature on non-linear conductivity characteristics. The research results illustrate that the β-SiC particles can provide a higher non-linear conductivity, compared with the α-SiC particles. The presence of temperature also affected the non-linear conductivity behaviors of the epoxy/SiC composites. When the α-SiC content was low, the non-linear conductivity coefficient of the composites increased rapidly as the temperature increased, but the non-linear conductivity decreased slightly as the temperature increased when the filler concentration was large enough. To reduce the influence of the electric field concentration effect by the increase in power density on the power module packaging, the voltage sharing application of the SiC/epoxy composites was simulated by COMSOL Multiphysics (v5.2a, COMSOL Inc., Stockholm, Sweden). The results show that the composites with non-linear conductivity can reduce the electric field stress. The emerging insulation material obtained by the SiC-modified epoxy resin can effectively promote electric field distribution uniformity, and ensure the safe operation of the power module.
Topology Optimization for Maximizing the Fracture Resistance of Periodic Quasi-Brittle Composites Structures
Authors: Da Daicong , Yvonnet Julien
Published: July 2020

Topology optimization for maximizing the fracture resistance of particle-matrix composites is investigated. The methodology developed in our previous works, combining evolutionary topology optimization and phase field method to fracture embedding interfacial damage, is applied and extended to periodic composites and multiple objectives. On one hand, we constrain the periodicity of unit cells geometry and conduct their topology optimization for one given load prescribed over the whole structure. On the other hand, we consider a single unit cell whose topology is optimized with respect to the fracture energy criterion when subjected to multiple loads. Size effects are investigated. We show that significant enhancement of the fracture resistance can be achieved for the studied composite structures by the present method. In addition, a first attempt to fracture resistance enhancement of a unit cell associated with a material is investigated for multiple loads, exhibiting a complex optimized microstructure.
Research on Residual Stress of a BS700 Butt-Welded Box Section and Its Influence on the Stability of Axial Compression Members
Authors: Xie Xingkun , Shao Fei , Gao Lei , He Lixiang , Bai Linyue
Published: July 2020

BS700 high-strength steel is widely used in engineering. Welding residual stress during the manufacturing process has a significant influence on the structural safety and service life of steel structures. In this study, the residual stress of a BS700 butt-welded box section axial compression member was studied by the blind-hole method, its distribution law was summarized, and a residual stress distribution model was established. By establishing a finite element model considering initial geometric imperfection and residual stress, the influence of residual stress on the stability of axial compression members was analyzed. The results illustrated that the residual tensile stress near the weld in the welded box section axial compression members was the largest: the average residual tensile stress reached 76.6% of the measured steel yield strength, the residual tensile stress at the roof and web were almost the same, and the residual tensile stress at the corner was approximately 11.6% of the measured yield strength. The residual stress had a different influence on the stability factor of the axial compression members with different width-thickness ratios, and the influence decreased with the increase in the width-thickness ratio. In addition, when the slenderness ratio of members ranged between 20 and 70, the residual stress had a significant influence on the stability of members, while outside that interval, the influence was relatively small.
Form-Stable Phase Change Materials Based on SEBS and Paraffin: Influence of Molecular Parameters of Styrene-b-(Ethylene-co-Butylene)-b-Styrene on Shape Stability and Retention Behavior
Authors: Rickert Ralf , Klein Roland , Schönberger Frank
Published: July 2020

In this work, the influence of molecular parameters of styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) triblock copolymer as matrix material in form-stable phase change material (FSPCM) on the thermo-mechanical properties and leakage behavior are studied. Various SEBS grades differing in their molecular weight, styrene content, and ethylene/butylene ratio are used as supporting matrix in composites with 90 wt.% paraffin. Thermo-mechanical properties are determined by rheological measurements. The results show phase transitions temperatures from solid to hard gel, hard gel to soft gel, and soft gel to gel fluid. Paraffin leakage in FSPCM is analyzed by mass loss over time in an oven at 60 °C. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) are applied to determine the thermal energy storage capacity. Finally, the molecular weight and the styrene content are combined to the molecular weight of styrene block which is identified as the authoritative parameter for the thermo-mechanical properties of the SEBS/PCM composite.