bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-Management of Diabetes and Associated Factors among Patients Seeking Chronic Care in Tshwane, South Africa: A Facility-Based Study
Authors: Zwane Janke , Modjadji Perpetua , Madiba Sphiwe , Moropeng Lucky , Mokgalaboni Kabelo , Mphekgwana Peter Modupi , Kengne Andre Pascal , Mchiza Zandile June-Rose
Published: May 2023

The burden of diabetes continues to increase in South Africa and a significant number of diabetes patients present at public primary healthcare facilities with uncontrolled glucose. We conducted a facility-based cross-sectional study to determine the diabetes self-management practices and associated factors among out-patients in Tshwane, South Africa. An adapted validated questionnaire was used to collect data on sociodemography, diabetes knowledge, and summaries of diabetes self-management activities measured in the previous seven days, and over the last eight weeks. Data were analysed using STATA 17. A final sample of 402 diabetes out-patients was obtained (mean age: 43 ± 12 years) and over half of them were living in poor households. The mean total diabetes self-management of score was 41.5 ± 8.2, with a range of 21 to 71. Almost two thirds of patients had average self-management of diabetes, and 55% had average diabetes knowledge. Twenty-two percent of patients had uncontrolled glucose, hypertension (24%) was the common comorbidity, and diabetic neuropathy (22%) was the most common complication. Sex [male: AOR = 0.55, 95% CI: 0.34–0.90], race [Coloured: AOR = 2.84, 95% CI: 1.69–4.77 and White: AOR = 3.84, 95% CI: 1.46–10.1], marital status [divorced: AOR = 3.41, 95% CI: 1.13–10.29], social support [average: AOR = 2.51, 95% CI: 1.05–6.00 and good: AOR = 4.49, 95% CI: 1.61–7.57], body mass index [obesity: AOR = 0.31, 95% CI: 0.10–0.95], diabetes knowledge [average: AOR = 0.58, 95% CI: 0.33–0.10 and good: AOR = 1.86, 95% CI: 0.71–4.91], and uncontrolled glucose [AOR = 2.97, 95% CI: 1.47–5.98] were factors independently predictive of diabetes self-management. This study emphasizes that the self-management of diabetes was mostly on average among patients and was associated with the aforementioned factors. Innovative approaches are perhaps needed to make diabetes education more effective. Face-to-face sessions delivered generally during clinic visits should be better tailored to the individual circumstances of diabetes patients. Considerations should be given to the options of leveraging information technology to ensure the continuity of diabetes education beyond clinic visits. Additional effort is also needed to meet the self-care needs of all patients.
Biocontrol of Xyleborus affinis (Curculionidae: Scolitinae) Females and Progeny by Beauveria bassiana (Hypocreales: Cordycipitaceae) in a Sawdust Artificial Diet Model
Authors: Castrejón-Antonio Jesús E. , Tamez-Guerra Patricia , García-Ortiz Nohemi , Muñiz-Paredes Facundo , Sánchez-Rangel Juan Carlos , Montesinos-Matías Roberto
Published: May 2023

The ambrosia beetle Xyleborus affinis, recently reported affecting avocado trees in Mexico, represents one of the most widespread insects worldwide. Previous reports have shown that Xyleborus genera members are susceptible to Beauveria bassiana and other entomopathogenic fungus strains. However, their effect on borer beetles’ progeny has not been fully investigated. The aim of the present study was to determine the insecticidal activity of B. bassiana on X. affinis adult females and their progeny in an artificial sawdust diet bioassay model. The B. bassiana strains CHE-CNRCB 44, 171, 431, and 485 were individually tested on females at concentrations ranging from 2 × 106 to 1 × 109 conidia mL−1. After 10 d of incubation, diet was evaluated to count laid eggs, larvae, and adults. Insect conidia loss after exposure was determined by attached conidia to each insect after 12 h of exposure. The results showed that females’ mortality ranged between 3.4% and 50.3% in a concentration–response manner. Furthermore, we did not observe statistical differences among strains at the highest concentration. CHE-CNRCB 44 showed the highest mortality at the lowest concentration and reduced larvae and laid eggs at the highest concentration (p < 0.01). Strains CHE-CNRCB 44, 431, and 485 significantly decreased larvae, as compared with the untreated control. After 12 h, up to 70% of conidia was removed by the effect of the artificial diet. In conclusion, B. bassiana has the potential to control X. affinis adult females and progeny.
Predicting Responses to Electroconvulsive Therapy in Adolescents with Treatment-Refractory Depression Based on Resting-State fMRI
Authors: Li Xiao , Guo Jiamei , Chen Xiaolu , Yu Renqiang , Chen Wanjun , Zheng Anhai , Yu Yanjie , Zhou Dongdong , Dai Linqi , Kuang Li
Published: May 2023

Objects: The efficacy of electroconvulsive therapy (ECT) in the treatment of adolescents with treatment-refractory depression is still unsatisfactory, and the individual differences are large. It is not clear which factors are related to the treatment effect. Resting-state fMRI may be a good tool to predict the clinical efficacy of this treatment, and it is helpful to identify the most suitable population for this treatment. Methods: Forty treatment-refractory depression adolescents were treated by ECT and evaluated using HAMD and BSSI scores before and after treatment, and were then divided into a treatment response group and a non-treatment group according to the reduction rate of the HAMD scale. We extracted the ALFF, fALFF, ReHo, and functional connectivity of patients as predicted features after a two-sample t-test and LASSO to establish and evaluate a prediction model of ECT in adolescents with treatment-refractory depression. Results: Twenty-seven patients achieved a clinical response; symptoms of depression and suicidal ideation were significantly improved after treatment with ECT, which was reflected in a significant decrease in the scores of HAMD and BSSI (p < 0.001). The efficacy was predicted by ALFF, fALFF, ReHo, and whole-brain-based functional connectivity. We found that models built on a subset of features of ALFF in the left insula, fALFF in the left superior parietal gyrus, right superior parietal gyrus, and right angular, and functional connectivity between the left superior frontal gyrus, dorsolateral–right paracentral lobule, right middle frontal gyrus, orbital part–left cuneus, right olfactory cortex–left hippocampus, left insula–left thalamus, and left anterior cingulate gyrus–right hippocampus to have the best predictive performance (AUC > 0.8). Conclusions: The local brain function in the insula, superior parietal gyrus, and angular gyrus as well as characteristic changes in the functional connectivity of cortical–limbic circuits may serve as potential markers for efficacy judgment of ECT and help to provide optimized individual treatment strategies for adolescents with depression and suicidal ideation in the early stages of treatment.
Concomitant Autoimmunity in Endometriosis Impairs Endometrium–Embryo Crosstalk at the Implantation Site: A Multicenter Case-Control Study
Authors: Salmeri Noemi , Gennarelli Gianluca , Vanni Valeria Stella , Ferrari Stefano , Ruffa Alessandro , Rovere-Querini Patrizia , Pagliardini Luca , Candiani Massimo , Papaleo Enrico
Published: May 2023

Endometriosis and autoimmune diseases share a hyper-inflammatory state that might negatively impact the embryo–endometrium crosstalk. Inflammatory and immune deregulatory mechanisms have been shown to impair both endometrial receptivity and embryo competence at the implantation site. The aim of this study was to investigate the potential additional impact of co-existing autoimmunity in women affected by endometriosis on the early stages of reproduction. This was a retrospective, multicenter case-control study enrolling N = 600 women with endometriosis who underwent in vitro fertilization–embryo transfer cycles between 2007 and 2021. Cases were women with endometriosis and concomitant autoimmunity matched based on age and body mass index to controls with endometriosis only in a 1:3 ratio. The primary outcome was the cumulative clinical pregnancy rate (cCPR). The study found significantly lower cleavage (p = 0.042) and implantation (p = 0.029) rates among cases. Autoimmunity (p = 0.018), age (p = 0.007), and expected poor response (p = 0.014) were significant negative predictors of cCPR, with an adjusted odds ratio of 0.54 (95% CI, 0.33–0.90) for autoimmunity. These results suggest that the presence of concomitant autoimmunity in endometriosis has a significant additive negative impact on embryo implantation. This effect might be due to several immunological and inflammatory mechanisms that interfere with both endometrial receptivity and embryo development and deserves further consideration.
Why a Complete Response Is the Treatment Aim in Chronic Spontaneous Urticaria
Authors: Bernstein Jonathan A. , Giménez-Arnau Ana , Maurer Marcus , Staubach Petra , Barbier Nathalie , Hua Eva , Severin Thomas , Laires Pedro A. , Balp Maria-Magdalena
Published: May 2023

This study investigated the association between urticaria activity and health-related quality of life (HRQoL). Patient evaluations from the ligelizumab Phase 2b clinical trial (N = 382) were pooled (NCT02477332). Daily patient diaries assessed urticaria activity, sleep and activity interference, the dermatology life quality index (DLQI), and work productivity and activity impairment-chronic urticaria (WPAI-CU). The number of DLQI scores, weekly sleep interference scores (SIS7), weekly activity interference scores (AIS7), and overall work impairment (OWI) evaluations with a complete response per weekly urticaria activity score (UAS7) using bands (0, 1–6, 7–15, 16–27, and 28–42) were reported. Over 50% of the patients had a mean DLQI of > 10 at baseline, indicating a significant effect of chronic spontaneous urticaria (CSU) on their HRQoL. Complete response (UAS7 = 0) evaluations corresponded with no impacts on other patient-reported outcomes. In total, 91.1% of UAS7 = 0 evaluations corresponded to DLQI scores of 0–1, 99.7% to SIS7 scores of 0, 99.7% to AIS7 scores of 0, and 85.3% to OWI scores of 0. This was significantly different compared with the UAS7 = 1–6 evaluations (61.9%, 68.5%, 67.7%, and 65.4%, respectively; p < 0.0001). Complete responses to treatment were associated with no impairments on the dermatology-QoL, no interferences with sleep and activity, and significantly improved capacities to work compared to patients who continued to have signs and symptoms, even for those with minimal disease activity.
Mitral and Tricuspid Valve Disease in Athletes
Authors: Segreti Andrea , Celeski Mihail , Monticelli Luigi Maria , Perillo Alfonso , Crispino Simone Pasquale , Di Gioia Giuseppe , Cammalleri Valeria , Fossati Chiara , Mega Simona , Papalia Rocco , Pigozzi Fabio , Ussia Gian Paolo , Grigioni Francesco
Published: May 2023

Observing mitral or tricuspid valve disease in an athlete raises many considerations for the clinician. Initially, the etiology must be clarified, with causes differing depending on whether the athlete is young or a master. Notably, vigorous training in competitive athletes leads to a constellation of structural and functional adaptations involving cardiac chambers and atrioventricular valve systems. In addition, a proper evaluation of the athlete with valve disease is necessary to evaluate the eligibility for competitive sports and identify those requiring more follow-up. Indeed, some valve pathologies are associated with an increased risk of severe arrhythmias and potentially sudden cardiac death. Traditional and advanced imaging modalities help clarify clinical doubts, allowing essential information about the athlete’s physiology and differentiating between primary valve diseases from those secondary to training-related cardiac adaptations. Remarkably, another application of multimodality imaging is evaluating athletes with valve diseases during exercise to reproduce the sport setting and better characterize the etiology and valve defect mechanism. This review aims to analyze the possible causes of atrioventricular valve diseases in athletes, focusing primarily on imaging applications in diagnosis and risk stratification.
A Real-World Prognosis in Idiopathic Pulmonary Fibrosis: A Special Reference to the Role of Antifibrotic Agents for the Elderly
Authors: Honda Kojiro , Saraya Takeshi , Ishii Haruyuki
Published: May 2023

Background: Idiopathic pulmonary fibrosis (IPF) is the most common and severe form of idiopathic interstitial pneumonia, and its prevalence increases with age. In the era of pre-antifibrotic agents, the median survival time of Japanese patients with IPF is 35 months, with a 5-year survival rate in western countries ranging from 20% to 40%. The prevalence of IPF is highest in elderly patients aged ≥75 years; however, the efficacy and safety of long-term use of pirfenidone and/or nintedanib are not fully understood. Objective: This study aimed to determine the efficacy and safety of the sole use of antifibrotic agents (pirfenidone or nintendanib) for IPF in the elderly. Method: We retrospectively reviewed patients with IPF who were diagnosed and treated with either pirfenidone or nintedanib in our hospital between 2008 and 2019. We excluded patients with the subsequent use of both antifibrotic agents. We examined the survival probability and frequency of acute exacerbation, with focus on long-term use (≥1 year), elderly patients (≥75 years of age), and disease severity. Results: We identified 91 patients with IPF (male to female ratio: 63 to 28, age 42 to 90 years). The numbers of patients with disease severity classified by JRS (I/II/III/IV) and GAP stage (I/II/III) were (38/6/17/20) and (39/36/6), respectively. The survival probabilities were comparable between the elderly (n = 46) and non-elderly groups (n = 45, p = 0.877). After the initiation of antifibrotic agents, the cumulative incidence ratio of acute exacerbation of IPF was significantly lower in the early stage (GAP stage I, n = 20) than in the progressive stage of disease (GAP stages II and III, n = 20, p = 0.028). A similar trend was noted in the JRS disease severity classification (I, II vs. III, IV) (n = 27 vs. n = 13, p = 0.072). In the long-term treatment (≥1 year) group (n = 40), the survival probabilities at 2 and 5 years after treatment initiation were 89.0% and 52.4%, respectively, which did not reach the median survival rate. Conclusions: Even in elderly patients (≥75 years of age), antifibrotic agents demonstrated positive effects on survival probability and the frequency of acute exacerbation. These positive effects would be improved for earlier JRS/GAP stages or long-term use.
Relation between Photogrammetry and Spinal Mouse for Sagittal Imbalance Assessment in Adolescents with Thoracic Kyphosis
Authors: Belli Guido , Toselli Stefania , Mauro Mario , Maietta Latessa Pasqualino , Russo Luca
Published: May 2023

The evaluation of postural alignment in childhood and adolescence is fundamental for sports, health, and daily life activities. Spinal Mouse (SM) and photogrammetry (PG) are two of the most debated tools in postural evaluation because choosing the proper instrument is also important to avoid false or misleading data. This research aims to find out the best linear regression models that could relate the analytic kyphosis measurements of the SM with one or more PG parameters of body posture in adolescents with kyphotic posture. Thirty-four adolescents with structural and non-structural kyphosis were analyzed (13.1 ± 1.8 years; 1.59 ± 0.13 m; 47.0 ± 12.2 kg) using SM and PG on the sagittal plane in a standing and forward-bending position, allowing us to measure body vertical inclination, trunk flexion, and sacral inclination and hip position during bending. The stepwise backward procedure was assessed to estimate the variability of the grade of inclination of the spine and thoracic spine curvature with fixed upper and lower limits, evaluated with SM during flexion. In both models, the PG angle between the horizontal line and a line connecting the sacral endplate–C7 spinous process and the PG hip position were the best regressors (adjusted-R2 SM bend = 0.804, p < 0.001; adjusted-R2 SM fixed bending = 0.488, p < 0.001). Several Spinal Mouse and photogrammetry parameters showed significant correlations, especially when the Spinal Mouse measurements were taken when the adolescents were in the forward-bending position. Physicians and kinesiologists may consider photogrammetry as a good method for spinal curve prediction.
Tomosynthesis-Detected Architectural Distortions: Correlations between Imaging Characteristics and Histopathologic Outcomes
Authors: Romanucci Giovanna , Fornasa Francesca , Caneva Andrea , Rossati Claudia , Mandarà Marta , Tommasini Oscar , Rella Rossella
Published: May 2023

Objective: to determine the positive predictive value (PPV) of tomosynthesis (DBT)-detected architectural distortions (ADs) and evaluate correlations between AD’s imaging characteristics and histopathologic outcomes. Methods: biopsies performed between 2019 and 2021 on ADs were included. Images were interpreted by dedicated breast imaging radiologists. Pathologic results after DBT-vacuum assisted biopsy (DBT-VAB) and core needle biopsy were compared with AD detected by DBT, synthetic2D (synt2D) and ultrasound (US). Results: US was performed to assess a correlation for ADs in all 123 cases and a US correlation was identified in 12/123 (9.7%) cases, which underwent US-guided core needle biopsy (CNB). The remaining 111/123 (90.2%) ADs were biopsied under DBT guidance. Among the 123 ADs included, 33/123 (26.8%) yielded malignant results. The overall PPV for malignancy was 30.1% (37/123). The imaging-specific PPV for malignancy was 19.2% (5/26) for DBT-only ADs, 28.2% (24/85) for ADs visible on DBT and synth2D mammography and 66.7% (8/12) for ADs with a US correlation with a statistically significant difference among the three groups (p = 0.01). Conclusions: DBT-only ADs demonstrated a lower PPV of malignancy when compared with syntD mammography, and DBT detected ADs but not low enough to avoid biopsy. As the presence of a US correlate was found to be related with malignancy, it should increase the radiologist’s level of suspicion, even when CNB returned a B3 result.
An Overview of Natural Fiber Composites for Marine Applications
Authors: El Hawary Omar , Boccarusso Luca , Ansell Martin P. , Durante Massimo , Pinto Fulvio
Published: May 2023

Environmental emergency awareness has been gaining momentum in recent years in the composite manufacturing industry, with a new generation of composite materials minimizing their harmful environmental impacts by employing more sustainable manufacturing processes and, where possible, replacing synthetic materials with more sustainable bio-based materials, thus more efficiently using energy and material resources. In this context, natural fiber composites are proposed as appealing candidates to replace or reduce the use of synthetic fibers for reinforcing polymers in several industrial fields, such as the marine sector, where composite usage has been extensively studied in recent years. This review aims to present a thorough overview of the usage of natural fiber composites for marine applications, discussing the most relevant criteria required for applications where water exposure is expected. For this purpose, the review outlines the natural fibers and matrices used, analyzes the resultant composites’ mechanical properties, and presents the fiber treatments required before manufacturing, as well as the main manufacturing processes adopted for natural fiber composite production. The advantages and disadvantages of natural fibers compared to synthetic fibers are also presented, including economic and environmental credentials. Finally, a list of marine components with natural fiber reinforcements developed in recent years is reported.
Economic Valuation of Mangroves and a Linear Mixed Model-Assisted Framework for Identifying Its Main Drivers: A Case Study in Benin
Authors: Sinsin Corine Bitossessi Laurenda , Bonou Alice , Salako Kolawolé Valère , Gbedomon Rodrigue Castro , Glèlè Kakaï Romain Lucas
Published: May 2023

Mangroves are brackish wetland ecosystems found in tropical areas. They are highly productive ecosystems that contribute to the economic empowerment of local communities. Proper estimation of their monetary value and the extent of their contribution to rural households’ income, although challenging, is paramount for sustainable management decisions. This study aimed to estimate the total economic wealth earned from mangrove ecosystems in Benin. Specifically, the study assessed the diversity of ecosystem services (ESs) provided by mangroves and the contribution of ESs to the total annual economic value of mangroves, and it identified socio-demographic drivers of the total economic value at the individual informant level. In total, 298 informants from 15 villages were interviewed to determine the diversity of mangrove ESs. The ESs were then gathered per category. Household-level economic values of mangroves, economic values of mangroves per ES category, and total economic value were estimated by combining diverse approaches. The contribution of each category of ES to the total economic value (TEV) was determined. A Principal Component Analysis (PCA) was applied to describe the relationships between the economic value of categories of ESs. A Linear Mixed Effect Model (LMEM) was used to determine valid socio-demographic drivers of the TEV. Twenty-nine ESs were identified, with regulation and recreation services being the best contributors to annual TEV, which was estimated at USD 1.29 billion (USD 195,223.69/hectare). Stakeholdership followed by household size are the main socio-demographic drivers of TEV. The identified ESs and their estimated economic value can be incorporated into policy briefs and technical sheets to (i) promote ESs for the optimisation of TEV and (ii) raise awareness and funding for the conservation and sustainable management of mangrove ecosystems.
Long-Term Monitoring of Cardiac Involvement under Migalastat Treatment Using Magnetic Resonance Tomography in Fabry Disease
Authors: Gatterer Constantin , Beitzke Dietrich , Graf Senta , Lenz Max , Sunder-Plassmann Gere , Mann Christopher , Ponleitner Markus , Manka Robert , Fritschi Daniel , Krayenbuehl Pierre-Alexandre , Kamm Philipp , Dormond Olivier , Barbey Frédéric , Monney Pierre , Nowak Albina
Published: May 2023

Background: Fabry cardiomyopathy is characterized by left ventricular hypertrophy, myocardial fibrosis, arrhythmia, and premature death. Treatment with migalastat, an oral pharmacological chaperone, was associated with a stabilization of cardiac biomarkers and a reduction in left ventricular mass index, as measured by echocardiography. A recent study, using cardiac magnetic resonance (CMR) as the gold standard, found a stable course of myocardial involvement after 18 months of treatment with migalastat. Our study aimed to provide long-term CMR data for the treatment with migalastat. Methods: A total of 11 females and four males with pathogenic amenable GLA mutations were treated with migalastat and underwent 1.5T CMR imaging for routine treatment effect monitoring. The main outcome was a long-term myocardial structural change, reflected by CMR. Results: After migalastat treatment initiation, left ventricular mass index, end diastolic volume, interventricular septal thickness, posterior wall thickness, estimated glomerular filtration rate, and plasma lyso-Gb3 remained stable during the median follow-up time of 34 months (min.: 25; max.: 47). The T1 relaxation times, reflecting glycosphingolipid accumulation and subsequent processes up to fibrosis, fluctuated over the time without a clear trend. No new onset of late gadolinium enhancement (LGE) areas, reflecting local fibrosis or scar formation of the myocardium, could be detected. However, patients with initially present LGE showed an increase in LGE as a percentage of left ventricular mass. The median α-galactosidase A enzymatic activity increased from 37.3% (IQR 5.88–89.3) to 105% (IQR 37.2–177) of the lower limit of the respective reference level (p = 0.005). Conclusion: Our study confirms an overall stable course of LVMi in patients with FD, treated with migalastat. However, individual patients may experience disease progression, especially those who present with fibrosis of the myocardium already at the time of therapy initiation. Thus, a regular treatment re-evaluation including CMR is needed to provide the optimal management for each patient.
Review of Feeding Systems Affecting Production, Carcass Attributes, and Meat Quality of Ovine and Caprine Species
Authors: Ke Tiantian , Zhao Mengyu , Zhang Xiaoan , Cheng Yao , Sun Yiming , Wang Penghui , Ren Chunhuan , Cheng Xiao , Zhang Zijun , Huang Yafeng
Published: May 2023

Growth rate, carcass attributes, and meat quality traits of small ruminants (i.e., sheep and goats) depend on various factors, among which the feeding system is one of the most important factors. However, how feeding systems affect these parameters differ between sheep and goats. Therefore, this review aimed to evaluate the differences in how different feeding systems affect the growth performance, carcass characteristics, and meat quality of sheep and goats. It also explored the effects of a new finishing strategy—time-limited grazing with supplements on these traits. Compared with stalled feeding, finishing lambs/kids on pasture-only feed reduced the average daily gain (ADG) and carcass yield, while supplemented-grazing lambs/kids had near-equivalent or higher ADG and carcass attributes. Pasture-grazing increased the meat flavor intensity and healthy fatty acid content (HFAC) of lamb/kid meat. Supplemental grazing lambs had comparable or superior meat sensory attributes and increased meat protein and HFAC compared to stall-fed ones. In contrast, supplemental grazing only improved the meat color of kids but had little effect on other meat qualities. Moreover, time-limited grazing with supplemental concentrates increased the carcass yield and meat quality in lamb meat. Overall, the effects of different feeding systems on growth performance and carcass traits were comparable between sheep and goats but differed in terms of the meat quality.
The Emerging Role of Protein Phosphatase in Regeneration
Authors: Zhang Meiling , Liu Chenglin , Zhao Long , Zhang Xuejiao , Su Ying
Published: May 2023

Maintaining normal cellular behavior is essential for the survival of organisms. One of the main mechanisms to control cellular behavior is protein phosphorylation. The process of protein phosphorylation is reversible under the regulation of protein kinases and protein phosphatases. The importance of kinases in numerous cellular processes has been well recognized. In recent years, protein phosphatases have also been demonstrated to function actively and specifically in various cellular processes and thus have gained more and more attention from researchers. In the animal kingdom, regeneration frequently occurs to replace or repair damaged or missing tissues. Emerging evidence has revealed that protein phosphatases are crucial for organ regeneration. In this review, after providing a brief overview of the classification of protein phosphatases and their functions in several representative developmental processes, we highlight the critical roles that protein phosphatases play in organ regeneration by summarizing the most recent research on the function and underlying mechanism of protein phosphatase in the regeneration of the liver, bone, neuron, and heart in vertebrates.
Investigation of the Effect of Volumetric Hydrophobization on the Kinetics of Mass Transfer Processes Occurring in Cement Concretes during Corrosion
Authors: Konovalova Viktoriya S.
Published: May 2023

The entry of aggressive substances into the pore structure of concrete causes the development of corrosion processes and leads to the destruction of the cement stone structure. Hydrophobic additives provide high density and low permeability and are an effective barrier to the penetration of aggressive substances into the structure of cement stone. To assess the contribution of hydrophobization to the durability of the structure, it is necessary to know how much the processes of corrosive mass transfer slow down. To study the properties, structure and composition of the materials studied in the work (solid and liquid phases) before and after exposure to liquid-aggressive media, experimental studies were carried out using chemical and physicochemical analysis methods: determination of density, water absorption, porosity, water absorption and strength of cement stone; differential thermal analysis; quantitative analysis of calcium cations in liquid medium by complexometric titration. The article presents the results of studies of the effect on the operational characteristics of the introduction of a hydrophobic additive of calcium stearate into the cement mixture at the stage of concrete production. The effectiveness of volumetric hydrophobization was evaluated to prevent the penetration of an aggressive chloride-containing medium into the pore structure of concrete destruction and the leaching of calcium-containing components of cement stone. It was found that the introduction of calcium stearate in an amount of 0.8–1.3% by weight of cement increases the service life of a concrete product during corrosion in liquid chloride-containing media with a high degree of aggressiveness by four times.
Editorial for the Special Issue: “Characterization and Processing of Complex Materials”
Authors: Otsuki Akira
Published: May 2023

The Special Issue aimed to provide a forum for scientists and engineers to share and discuss their pioneering/original findings or insightful reviews on the “Characterization and Processing of Complex Materials” [...]
Welding of AA6061-T6 Sheets Using High-Strength 4xxx Fillers: Effect of Mg on Mechanical and Fatigue Properties
Authors: Ahmed Mohamed , Javidani Mousa , Maltais Alexandre , Chen X.-Grant
Published: May 2023

Al-Si-Mg 4xxx filler metals are widely used in aluminum welding owing to their excellent weldability and capability for strength enhancement by heat treatment. However, weld joints with commercial Al-Si ER4043 fillers often exhibit poor strength and fatigue properties. In this study, two novel fillers were designed and prepared by increasing the Mg content in 4xxx filler metals, and the effects of Mg on the mechanical and fatigue properties were studied under as-welded and post-weld heat-treated (PWHT) conditions. AA6061-T6 sheets were used as the base metal and welded by gas metal arc welding. The welding defects were analyzed using X-ray radiography and optical microscopy, and the precipitates in the fusion zones were studied using transmission electron microscopy. The mechanical properties were evaluated using the microhardness, tensile, and fatigue tests. Compared to the reference ER4043 filler, the fillers with increased Mg content produced weld joints with higher microhardness and tensile strength. Joints made with fillers with high Mg contents (0.6–1.4 wt.%) displayed higher fatigue strengths and longer fatigue lives than joints made with the reference filler in both the as-welded and PWHT states. Of the joints studied, joints with the 1.4 wt.% Mg filler exhibited the highest fatigue strength and best fatigue life. The improved mechanical strength and fatigue properties of the aluminum joints were attributed to the enhanced solid-solution strengthening by solute Mg in the as-welded condition and the increased precipitation strengthening by β″ precipitates in the PWHT condition.
STM Study of the Initial Stage of Gold Intercalation of Graphene on Ir(111)
Authors: Mikšić Trontl Vesna , Jedovnicki Ivan , Pervan Petar
Published: May 2023

In this paper, we present a study of the sub-monolayer gold intercalation of graphene on Ir(111) using scanning tunnelling microscopy (STM). We found that Au islands grow following different kinetics than growth on Ir(111) without graphene. Graphene appears to increase the mobility of Au atoms by shifting the growth kinetics of Au islands from dendritic to a more compact shape. Graphene on top of intercalated gold exhibits a moiré superstructure, with parameters significantly different from graphene on Au(111) but almost identical to graphene on Ir(111). The intercalated Au monolayer shows a quasi-herringbone reconstruction with similar structural parameters as on Au(111).
Experimental Investigation of Cobalt Deposition on 304 Stainless Steel in Borated and Lithiated High-Temperature Water
Authors: Deng Jian , Lei Jieheng , Wang Guolong , Zhong Lin , Zhao Mu , Lei Zeyong
Published: May 2023

The radioactive corrosion products 58Co and 60Co in the primary loops of pressurized water reactors (PWRs) are the main sources of radiation doses to which workers in nuclear power plants are exposed. To understand cobalt deposition on 304 stainless steel (304SS), which is the main structural material used in the primary loop, the microstructural characteristics and chemical composition of a 304SS surface layer immersed for 240 h in borated and lithiated high-temperature water containing cobalt were investigated with scanning electron microscopy (SEM), X-ray diffraction (XRD), laser Raman spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), glow discharge optical emission spectrometry (GD-OES), and inductively coupled plasma emission mass spectrometry (ICP-MS). The results showed that two distinct cobalt deposition layers (an outer layer of CoFe2O4 and an inner layer of CoCr2O4) were formed on the 304SS after 240 h of immersion. Further research showed that CoFe2O4 was formed on the metal surface by coprecipitation of the iron preferentially dissolved from the 304SS surface with cobalt ions from the solution. The CoCr2O4 was formed by ion exchange between the cobalt ions entering the metal inner oxide layer and (Fe, Ni) Cr2O4. These results are useful in understanding cobalt deposition on 304SS and have a certain reference value for exploring the deposition behavior and mechanism of radionuclide cobalt on 304SS in the PWR primary loop water environment.
Microstructure and Mechanical Properties of TA2/Q235 Laser Weld Joint with Copper Interlayer
Authors: Zhang Liang , Wang Qi , Guo Xiaolei , Chen Pan , Wang Yinling , Wang Chen , Wang Zhanxue , Wang Zongling
Published: May 2023

For the dissimilar metal welding needs of TA2 titanium and Q235 steel, preliminary trials were conducted using laser welding methods, and the results showed that the addition of a copper interlayer and the bias of the laser beam toward the Q235 side allowed for an effective connection. The welding temperature field was simulated using the finite element method, and the optimum offset distance of 0.3 mm was obtained. Under the optimized parameters, the joint had good metallurgical bonding. Further SEM analysis showed that the microstructure of the bonding area between the weld bead and Q235 was a typical fusion weld pattern, while that of the bonding area between the weld bead and TA2 was in brazing mode. The microhardness of the cross-section showed complex fluctuations; the microhardness of the weld bead center was higher than that of the base metal due to the formation of a mixture microstructure of copper and dendritic Fe phases. The copper layer not involved in the weld pool mixing had almost the lowest microhardness. The highest microhardness was found at the bonding site of TA2 and the weld bead, mainly due to the formation of an intermetallic layer with a thickness of about 100 μm. Further detailed analysis revealed that the compounds included Ti2Cu, TiCu and TiCu2, showing a typical peritectic morphology. The tensile strength of the joint was approximately 317.6 MPa, reaching 82.71% of that of the Q235 and 75.44% of the TA2 base metal, respectively. The fracture occurred in the unmixed copper layer.
Polysiloxanes and Silanes with Various Functional Groups—New Compounds for Flax Fibers’ Modification
Authors: Gieparda Weronika , Przybylak Marcin , Rojewski Szymon , Doczekalska Beata
Published: May 2023

There is an increasing desire to use natural products that will be both effective and biodegradable. The aim of this work is to investigate the effect of modifying flax fibers with silicon compounds (silanes and polysiloxanes), as well as examining the effect of the mercerization process on their properties. Two types of polysiloxanes have been synthesized and confirmed by infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (NMR). Scanning electron microscopy (SEM), FTIR, thermogravimetry analysis (TGA) and pyrolysis-combustion flow calorimetry (PCFC) tests of the fibers were performed. On the SEM pictures, flax fibers purified and covered with silanes were visible after treatment. FTIR analysis showed stable bonds between the fibers and the silicon compounds. Promising results of thermal stability were obtained. It was also found that modification had a positive effect on the flammability. The conducted research showed that the use of such modifications, in the context of using flax fibers for composites, can yield very good results.
A Study on Fire Retardant and Soundproof Properties of Stainless Steel EAF Reducing Slag Applied to Fiber Reinforced Cement Boards
Authors: Chou Chuan-Wen , Lin Hung-Ming , Chen Guan-Bang , Wu Fang-Hsien , Chen Chen-Yu
Published: May 2023

In recent years, cases of the improper utilization of steel furnace slag have been widely reported, resulting in a crisis of nowhere for recycled resources such as inorganic slag. The misplacement of resource materials that originally had sustainable-use value not only has a great impact on society and the environment but also greatly reduces industrial competitiveness. To solve the dilemma of steel furnace-slag reuse, it is critical to find solutions to the stabilization of steelmaking slag under the innovative thinking of the circular economy. In addition to enhancing the reuse value of recycled resources, the balance between economic development and environmental impact is also crucial. The high-performance building material could provide a solution based on a high-value market. With the development of society and the increasing requirements for quality of life, the requirements for the soundproof and fireproof performance of lightweight decorative panels common in cities have gradually become popular. Therefore, the high performance of fire retardant and soundproofing could be the main development focus of high-value building materials to ensure circular economic feasibility. This study continues the research results of the application of inorganic re-cycled engineering materials in recent years, and the application of electric-arc furnace (EAF)-reducing slag to the development of base materials for reinforced cement boards, in order to complete the development of high-value panels with fireproof and sound-insulation properties in line with the engineering characteristics of the boards. The research results showed the optimization of the proportions of the cement boards with EAF-reducing slag as a raw material. The proportions of EAF-reducing slag to fly ash at ratios of 70:30 and 60:40 all met the requirements of ISO 5660-1 Class I flame resistance; the sound transmission loss in the overall frequency band can reach more than 30 dB, which is higher by 3–8 dB or more than the same board with similar specifications (such as 12 mm gypsum board) in the present building-materials market The products could be developed into building partitions and ceiling decoration boards with high performance in terms of fire retardant and soundproofing values, and also reduce the use of natural raw materials by more than 35%. The results of this study could meet environmental compatibility targets and contribute towards greener buildings. This model of circular economics would achieve energy reduction, emissions reductions, and be environmentally friendly.
Measurement Methods of the Thermal Resistance of Materials Used in Clothing
Authors: Rogale Dubravko , Firšt Rogale Snježana , Knezić Željko , Jukl Nikolina , Majstorović Goran
Published: May 2023

This paper describes methods for evaluating the thermal properties of textile materials, clothing composites, and clothing using an integrated measurement system that includes a hot plate, a multi-purpose differential conductometer, a thermal manikin, a temperature gradient measurement device, and a device for measuring the physiological parameters of the human body during the exact evaluation of garment thermal comfort. In practice, measurements were taken on four types of materials widely used in the production of conventional and protective clothing. The measurements were carried out using a hot plate and a multi-purpose differential conductometer, determining the thermal resistance of the material both in its uncompressed form and when a force was applied that was ten times greater than that needed to determine its thickness. Using a hot plate and a multi-purpose differential conductometer, thermal resistances of textile materials were assessed at different levels of material compression. On hot plates, both conduction and convection had an impact on thermal resistance, but in the multi-purpose differential conductometer, only conduction did. Moreover, a reduction in thermal resistance was observed as a result of compressing textile materials.
Strength–Toughness of a Low-Alloy 0.25C Steel Treated by Q&P Processing
Authors: Tkachev Evgeniy , Borisov Sergey , Borisova Yuliya , Kniaziuk Tatiana , Gaidar Sergey , Kaibyshev Rustam
Published: May 2023

Quenching and partitioning (Q&P) treatments were applied to 0.25C steel to produce the microstructures that exhibit an improved balance of mechanical properties. The simultaneous bainitic transformation and carbon enrichment of retained austenite (RA) during the partitioning stage at 350 °C result in the coexistence of RA islands with irregular shapes embedded in bainitic ferrite and film-like RA in the martensitic matrix. The decomposition of coarse RA islands and the tempering of primary martensite during partitioning is accompanied by a decrease in the dislocation density and the precipitation/growth of η-carbide in the lath interiors of primary martensite. The best combinations of a yield strength above 1200 MPa and an impact toughness of about 100 J were obtained in the steel samples quenched to 210–230 °C and subjected to partitioning at 350 °C for 100–600 s. A detailed analysis of the microstructures and the mechanical properties of the steel subjected to Q&P, water quenching, and isothermal treatment revealed that the ideal strength–toughness combinations could be attributed to the mixture of the tempered lath martensite with finely dispersed and stabilized RA and the particles of η-carbide located in the lath interiors.
Mechanical Properties of High Carbon Low-Density Steels
Authors: Hájek Jiří , Nový Zbyšek , Kučerová Ludmila , Jirková Hana , Donik Črtomir , Jansa Zdeněk
Published: May 2023

The paper presents the possibilities of heat treatment of low-density structural steels usable for springs. Heats have been prepared with chemical compositions 0.7 wt% C and 1 wt% C, as well as 7 wt% Al and 5 wt% Al. Samples were prepared from ingots weighing approximately 50 kg. These ingots were homogenised, then forged, and hot rolled. Primary transformation temperatures and specific gravity values were determined for these alloys. For low-density steels, there usually needs to be a solution to achieve the required ductility values. At cooling rates of 50 °C/s and 100 °C/s, the kappa phase is not present. A SEM analysed the fracture surfaces for the presence of transit carbides during tempering. The martensite start temperatures ranged from 55–131 °C, depending on the chemical composition. The densities of the measured alloys were 7.08 g/cm3 and 7.18 g/cm3, respectively. Therefore, heat treatment variation was carried out to achieve a tensile strength of over 2500 MPa, with ductility of almost 4%. Hardnesses above 60 HRC were achieved for 1 wt% C heats using the appropriate heat treatment.
Replacing Induction Motors without Defined Efficiency Class by IE Class: Example of Energy, Economic, and Environmental Evaluation in 1.5 kW—IE3 Motors
Authors: Torrent Marcel , Blanqué Balduí , Monjo Lluís
Published: May 2023

This paper shows the results obtained from the study on the variables that have the greatest influence on the decision to replace three-phase induction motors, without a defined efficiency class and installed in industrial applications, with IE3 efficiency class induction motors. The work has been carried out on motors with a nominal power of 1.5 kW due to the availability of laboratory tests that have allowed us to accurately quantify the selected study variables. According to IEC 60034-30, between 0.75 kW and 4 kW is the greatest potential for energy savings in electric motors installed within the industrial sector. The tests carried out have made it possible to assess different operating conditions of the motor: direct power supply from the grid, electronic power supply using scalar control, and electronic power supply using direct torque control. The study has focused on three aspects: energy evaluation, assessing the savings potential; economic evaluation, based on indicators such as Payback Period and Net Present Value; environmental assessment, quantifying the impact indicators proposed by the Methodology for Ecodesign of Energy-related Products (MEErP). A sensitivity analysis has been carried out to quantify, through ratios, different operating points from those directly analyzed in the article.
Novel and Efficient Methodology for Drop Placement Accuracy Testing of Robot-Guided Inkjet Printing onto 3D Objects
Authors: Thalheim Robert , Willert Andreas , Mitra Dana , Zichner Ralf
Published: May 2023

Robot-guided inkjet printing technology offers a new way for the digital and additive deposition of low-viscous inks to be made directly onto arbitrary surfaces and, thus, enables the production of individualized printed electronics on large-scale objects. When compared to conventional flatbed printing, the distance between the nozzle plate and the object’s surface varies and needs to be considered in order to match the accuracy requirements needed for the positioning of single drops. Knowledge about applicable distance limits and the influence of tunable print parameters is crucial for improving the print process and results. This study discusses the sources of errors in the inkjet printing process onto 3D objects and presents extensive results about position accuracy in relation to jetting distance for different parameter sets of functional inks, drop volumes, and piezo voltages. Additionally, an efficient novel method was applied to determine the drop position accuracy of inkjet droplets in relation to the jetting distance. The method relies on cylinder geometry for the object and an inkjet head that is guided by a six-axis robot manipulator along the cylinder’s axis. For the determination of drop placement accuracy, the position of single dots on the surface was compared to a model which considered the cylinder radii, drop velocity, and the movement speed of the guided inkjet printhead. The method and the extensive research results can be utilized for the prediction of achievable drop placement accuracy and the prior definition of distance limits.