bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondrial Dysfunction: A Common Hallmark Underlying Comorbidity between sIBM and Other Degenerative and Age-Related Diseases
Authors: Catalán-García Marc , García-García Francesc Josep , Moreno-Lozano Pedro J. , Alcarraz-Vizán Gema , Tort-Merino Adrià , Milisenda José César , Cantó-Santos Judith , Barcos-Rodríguez Tamara , Cardellach Francesc , Lladó Albert , Novials Anna , Garrabou Glòria , Grau-Junyent Josep M.
Published: May 2020

Sporadic inclusion body myositis (sIBM) is an inflammatory myopathy associated, among others, with mitochondrial dysfunction. Similar molecular features are found in Alzheimer’s disease (AD) and Type 2 Diabetes Mellitus (T2DM), underlying potential comorbidity. This study aims to evaluate common clinical and molecular hallmarks among sIBM, AD, and T2DM. Comorbidity with AD was assessed in n = 14 sIBM patients by performing neuropsychological and cognitive tests, cranial magnetic resonance imaging, AD cerebrospinal fluid biomarkers (levels of amyloid beta, total tau, and phosphorylated tau at threonine-181), and genetic apolipoprotein E genotyping. In the same sIBM cohort, comorbidity with T2DM was assessed by collecting anthropometric measures and performing an oral glucose tolerance test and insulin determinations. Results were compared to the standard population and other myositis (n = 7 dermatomyositis and n = 7 polymyositis). Mitochondrial contribution into disease was tested by measurement of oxidative/anaerobic and oxidant/antioxidant balances, respiration fluxes, and enzymatic activities in sIBM fibroblasts subjected to different glucose levels. Comorbidity of sIBM with AD was not detected. Clinically, sIBM patients showed signs of misbalanced glucose homeostasis, similar to other myositis. Such misbalance was further confirmed at the molecular level by the metabolic inability of sIBM fibroblasts to adapt to different glucose conditions. Under the standard condition, sIBM fibroblasts showed decreased respiration (0.71 ± 0.08 vs. 1.06 ± 0.04 nmols O2/min; p = 0.024) and increased anaerobic metabolism (5.76 ± 0.52 vs. 3.79 ± 0.35 mM lactate; p = 0.052). Moreover, when glucose conditions were changed, sIBM fibroblasts presented decreased fold change in mitochondrial enzymatic activities (−12.13 ± 21.86 vs. 199.22 ± 62.52 cytochrome c oxidase/citrate synthase ratio; p = 0.017) and increased oxidative stress per mitochondrial activity (203.76 ± 82.77 vs. −69.55 ± 21.00; p = 0.047), underlying scarce metabolic plasticity. These findings do not demonstrate higher prevalence of AD in sIBM patients, but evidences of prediabetogenic conditions were found. Glucose deregulation in myositis suggests the contribution of lifestyle conditions, such as restricted mobility. Additionally, molecular evidences from sIBM fibroblasts confirm that mitochondrial dysfunction may play a role. Monitoring T2DM development and mitochondrial contribution to disease in myositis patients could set a path for novel therapeutic options.
Developmental Evaluation of Infants Who Have Received Tadalafil in Utero for Fetal Growth Restriction
Authors: Maki Shintaro , Kato Ineko , Enomoto Naosuke , Takakura Sho , Nii Masafumi , Tanaka Kayo , Tanaka Hiroaki , Hori Shinsuke , Matsuda Kana , Ueda Yukito , Sawada Hirofumi , Hirayama Masahiro , Sudo Akihiro , Ikeda Tomoaki
Published: May 2020

To assess the long-term effects of tadalafil, a therapeutic agent for fetal growth restriction (FGR), we evaluated the developmental progress of 1.5-year-old infants whose mothers had taken tadalafil during pregnancy. Twenty-four infants were assessed. We evaluated infant body weight, height, and head circumference, and performed the Kyoto Scale of Psychological Development (KSPD) test, a standardized developmental assessment covering Postural–Motor (P–M), Cognitive–Adaptive (C–A), and Language-Social (L–S) functions. The sum score was converted to a developmental quotient (DQ). The mean gestational week of the included cases was 36.1 (29–39) weeks, and the mean birth weight was 1841 (874–2646) g. Twenty-one and 20 out of the 24 cases, respectively, attained body weight and height similar to those of age-matched normal infants (within the 3rd percentile); all cases caught up in head circumference. KSPD was performed for 18 cases at 1.5 years of corrected age. The mean DQ scores were 87 (in total): 82 in P–M, 90 in C–A, and 88 in L–S. The total DQ score in one case (5.6%) was less than 70, and ranged from 70 to 85 in five cases (27.7%), and was more than 85 in 11 cases (61.1%). The growth and development of infants born of tadalafil-treated mothers seem to show good progress at a corrected age of 1.5 years.
Novel Multiplex Droplet Digital PCR Assays to Monitor Minimal Residual Disease in Chronic Myeloid Leukemia Patients Showing Atypical BCR-ABL1 Transcripts
Authors: Petiti Jessica , Lo Iacono Marco , Dragani Matteo , Pironi Lucrezia , Fantino Cristina , Rapanotti Maria Cristina , Quarantelli Fabrizio , Izzo Barbara , Divona Mariadomenica , Rege-Cambrin Giovanna , Saglio Giuseppe , Gottardi Enrico Marco , Cilloni Daniela , Fava Carmen
Published: May 2020

BCR-ABL1 fusion transcript is the minimal residual disease marker in chronic myeloid leukemia; 2% of patients show unusual breakpoints generating atypical transcripts, not quantifiable by standardized real-time PCR (RT–PCR). Response monitoring is performed by non-quantitative NESTED PCR, useless for evaluating patients’ molecular remission, excluding them from treatment-free-remission protocols. Droplet digital PCR (ddPCR) is highly sensitive technology, allowing an absolute quantification independent of standard curves. Based on this, we have developed assays able to evaluate the molecular response in atypical patients. We designed new ddPCR-based molecular assays able to quantify atypical BCR-ABL1 transcripts, with a detection limit of 0.001%, validated in a cohort of 65 RNA from 11 patients. Fifty samples were identified congruently by ddPCR and NESTED PCR (40 positives and 10 negatives for atypical BCR–ABL1 transcript), while 11 positive samples were detected only by ddPCR. Our results highlight ddPCR usefulness, primarily when the BCR–ABL1/ABL1 level is less than 1.5% and NESTED PCR results are often inaccurate. Furthermore, we identified 3 patients who maintained a deep molecular response for at least one year, who could be considered good candidates for treatment-free remission approaches. Here, we describe a new promising molecular approach, highly sensitive, to monitor atypical BCR–ABL1 patients, paving the foundation to include them in treatment-free remission protocols.
Differences in Results and Related Factors between Hospital-At-Home Modalities in Catalonia: A Cross-Sectional Study
Authors: Arias-de la Torre Jorge , Zioga Evangelia Anna María , Macorigh Lizza , Muñoz Laura , Estrada Oriol , Mias Montse , Estrada Maria-Dolors , Puigdomenech Elisa , Valderas Jose M. , Martín Vicente , Molina Antonio J. , Espallargues Mireia
Published: May 2020

Hospital-at-home (HaH) is a healthcare modality that provides active treatment by healthcare staff in the patient’s home for a condition that would otherwise require hospitalization. The aims were to describe the characteristics of different types of hospital-at-home (HaH), assess their results, and examine which factors could be related to these results. A cross-sectional study based on data from all 2014 HaH contacts from Catalonia was designed. The following HaH modalities were considered—admission avoidance (n = 7214; 75.1%) and early assisted discharge (n = 2387; 24.9%). The main outcome indicators were readmission, mortality, and length of stay (days). Multivariable models were fitted to assess the association between explanatory factors and outcomes. Hospital admission avoidance is a scheme in which, instead of being admitted to acute care hospitals, patients are directly treated in their own homes. Early assisted discharge is a scheme in which hospital in-care patients continue their treatment at home. In the hospital avoidance modality, there were 8.3% readmissions, 0.9% mortality, and a mean length of stay (SD) of 9.6 (10.6) days. In the early assisted discharge modality, these figures were 7.9%, 0.5%, and 9.8 (11.1), respectively. In both modalities, readmission and mean length of stay were related to comorbidity and type of hospital, and mortality with age. The results of HaH in Catalonia are similar to those observed in other contexts. The factors related to these results identified might help to improve the effectiveness and efficiency of the different HaH modalities.
Relationships among Retinal Nonperfusion, Neovascularization, and Vascular Endothelial Growth Factor Levels in Quiescent Proliferative Diabetic Retinopathy
Authors: Ra Ho , Park Jae Hyun , Baek Jin Uk , Baek Jiwon
Published: May 2020

Purpose: To investigate the relationships among the retinal nonperfusion (NP) area, neovascularization (NV) area, and aqueous humor vascular endothelial growth factor (VEGF) levels in quiescent proliferative diabetic retinopathy (PDR). Methods: Forty-seven eyes from 47 patients with treatment-naïve PDR that did not show macular edema or vitreous hemorrhage were enrolled. NP area, NV number, and NV area were quantitatively measured using ultra-widefield fluorescein angiography in an automated manner. Aqueous humor VEGF level was measured using a bead assay. Results: The NP areas of the total, posterior pole, peripheral retinae, and NV area positively correlated with each other (all p < 0.034). NV number correlated with total NP area, peripheral NP area, and NV area (all p ≤ 0.001). VEGF levels were significantly positively correlated with total, posterior polar, and peripheral NP areas and NV area (r = 0.575, 0.422, 0.558, and 0.362, respectively; all p ≤ 0.012). In eyes with NV in the disc area, the VEGF level was higher compare to eyes without NV in the disc area (208.89 ± 192.77 pg/mL vs. 103.34 ± 132.66, p = 0.010). A multiple linear regression model using NP area, NV area, and NVD demonstrated good prediction for VEGF level (R2 = 0.417, p < 0.001) and revealed a significant contribution of the peripheral NP area in predicting the VEGF level (β = 0.497, p = 0.002). Conclusions: Aqueous humor VEGF levels in quiescent PDR eyes were associated with NP and NV areas, which had positive correlations with each other. In addition, the NP area of the peripheral retina was the most important predictor of VEGF level.
Endoscopic Submucosal Dissection of Papillary Gastric Adenocarcinoma; Systematic Review
Authors: Bang Chang Seok , Lee Jae Jun , Baik Gwang Ho
Published: May 2020

This study evaluated the possibility of endoscopic submucosal dissection (ESD) for early gastric cancer with papillary adenocarcinoma (EGC-PAC). PAC, an uncommon pathologic type of stomach cancer, is classified into differentiated-type histology. However, aggressive features, including a high rate of submucosal invasion, lymphovascular invasion (LVI), and lymph node metastasis (LNM), have been reported in studies with surgical specimens. Treatment outcomes of ESD for EGC-PAC have not been precisely demonstrated. Core databases were sought for the following inclusion criteria: studies of endoscopic resection or surgery of EGC-PAC presenting the following therapeutic indicators; en bloc resection, complete resection, curative resection, recurrence, complications associated with procedures, LVI, or LNM that enabled an analysis of ESD possibility. Overall, 15 studies were included for systematic review. Frequent submucosal invasion and high LVI were noted in EGC-PAC. However, PAC was not significantly associated with LNM. Pooled en bloc resection, complete resection, and curative resection rates were 89.7% (95% confidence interval: 55.3%–98.4%), 85.3% (67.7%–94.2%), and 67% (43%–84.5%), respectively. No LNM was observed if EGC-PAC satisfied the curative resection criteria. ESD seems technically feasible, although a high LVI rate results in a lower rate of curative resection.
Glomerular Filtration Rate as a Predictor of Outcome in Acute Coronary Syndrome Complicated by Atrial Fibrillation
Authors: Santoro Domenico , Gembillo Guido , Andò Giuseppe
Published: May 2020

The close relationship between kidney and heart is well known. Cardiovascular impairment contributes to the worsening of renal function and kidney failure worsens cardiovascular health. Atrial fibrillation (AF) is a frequent issue in patients with Chronic Kidney Disease (CKD) and several studies have demonstrated that AF impacts negatively on their quality of life and outcomes. Understanding the mechanisms leading to the progression of CKD, new-onset AF and acute myocardial infarction (AMI) is a key issue. The evaluation of Glomerular Filtration Rate (GFR) could make the difference in this equilibrium and suggests specific strategies in the treatment of the population at major risk of cardiovascular events. This intriguing connection paves the way for necessary further investigations.
Increased Endotoxin Activity Is Associated with the Risk of Developing Acute-on-Chronic Liver Failure
Authors: Takaya Hiroaki , Namisaki Tadashi , Sato Shinya , Kaji Kosuke , Tsuji Yuki , Kaya Daisuke , Fujinaga Yukihisa , Sawada Yasuhiko , Shimozato Naotaka , Kawaratani Hideto , Moriya Kei , Akahane Takemi , Mitoro Akira , Yoshiji Hitoshi
Published: May 2020

Acute-on-chronic liver failure (ACLF) leads to systematic inflammatory response syndrome and multiple organ failure. This study investigated the relationship between endotoxin (Et) and ACLF with the aim of determining whether Et activity (EA) is useful as a predictive biomarker of ACLF development and whether rifaximin treatment decreased the risk of ACLF development. Two hundred forty-nine patients with liver cirrhosis were enrolled in this study. Et concentration was determined in the whole blood by a semiquantitative EA assay. Predictive factors of ACLF development and the risk of ACLF development with and without rifaximin treatment were identified by univariate and multivariate analysis using Fine and Gray’s proportional subhazards model. EA level was higher in Child-Pugh class B than in class A patients, and class B patients had an increased risk of ACLF development compared with class A patients. Multivariate analysis showed that EA level was a predictive factor independently associated with ACLF development. Rifaximin decreased EA level and the risk of ACLF development in Child-Pugh class B patients. Et levels were associated with functional liver capacity and were predictive of ACLF development in cirrhotic patients. Rifaximin decreased Et level and the risk of ACLF development in advanced cirrhotic patients.
Innate Immune System and Multiple Sclerosis. Granulocyte Numbers Are Reduced in Patients Affected by Relapsing-Remitting Multiple Sclerosis during the Remission Phase
Authors: Pavelek Zbyšek , Angelucci Francesco , Souček Ondřej , Krejsek Jan , Sobíšek Lukáš , Klímová Blanka , Šarláková Jana , Halúsková Simona , Kuča Kamil , Vališ Martin
Published: May 2020

Background: Multiple sclerosis (MS) is a neurodegenerative disease that affects the central nervous system. The cause of MS is still unknown, and the role of innate immunity is still poorly understood. Objective: The goal of this study was to understand whether, compared to healthy controls, the elements of innate immunity are altered in the blood of MS patients in the remitting phase. Methods: A total of 77 naïve MS patients and 50 healthy controls were included in this cohort study. Peripheral blood samples were collected and analyzed. All the calculations were performed with the statistical system R (r-project.org). Results: The results showed that MS patients had significantly lower relative representations of granulocytes than healthy controls, while the relative representations of monocytes remained unchanged. CD64- and PD-L1-positive granulocytes exhibited a nonsignificant decreasing trend, while granulocytes with other membrane markers remained noticeably unchanged. Conclusion: The results of this study suggest that studies of the causes of MS and its treatment should also be focused on the elements of the innate immune response.
Neonatal Immune Incompatibilities between Newborn and Mother
Authors: Arneth Borros
Published: May 2020

Background: Incompatibilities between the mother and unborn baby can cause complications that must be identified early to initiate the appropriate treatment. For example, neonatal alloimmune thrombocytopenia (NAIT), neonatal alloimmune neutropenia (NAIN), and morbus hemolyticus neonatorum affect children worldwide. Aim: This literature review aims to depict the similarities and differences between these three disorders from a clinical and mechanistic point of view. Material and Methods: The current literature review entailed conducting a systematic search to locate articles on the three conditions. Different electronic databases, including PsycINFO, PubMed, Web of Science, and CINAHL, were searched using the search terms “neonatal alloimmune thrombocytopenia”, “neonatal alloimmune neutropenia”, “morbus hemolyticus neonatorum”, “NAIT”, “FNAIT”, “fetal”, “NAIN”, and “hemolytic disease of the newborn”. Results: This review shows that these three diseases are caused by incompatibilities between the maternal and fetal immune systems. Furthermore, these conditions can lead to severe complications that hinder fetal development and cause death if not well managed. Discussion: The current literature review shows that NAIT, NAIN, and morbus hemolyticus neonatorum are rare conditions that occur when the mother produces antibodies against the fetal immune system. Thus, there is a need for the early detection of these conditions to initiate appropriate treatment before the child experiences adverse effects. Conclusion: The development of NAIT, NAIN, and morbus hemolyticus neonatorum is linked to the production of antibodies against the fetal immune system and fetal antigens. Further studies are required to determine potential interventions to reduce the risk of developing these three conditions.
Acute Kidney Injury after Endovascular Treatment in Patients with Acute Ischemic Stroke
Authors: Yoo Joonsang , Hong Jeong-Ho , Lee Seong-Joon , Kim Yong-Won , Hong Ji Man , Kim Chang-Hyun , Choi Jin Wook , Kang Dong-Hun , Kim Yong-Sun , Hwang Yang-Ha , Lee Jin Soo , Sohn Sung-Il
Published: May 2020

Acute kidney injury (AKI) is often associated with the use of contrast agents. We evaluated the frequency of AKI, factors associated with AKI after endovascular treatment (EVT), and associations with AKI and clinical outcomes. We retrospectively analyzed consecutively enrolled patients with acute ischemic stroke who underwent EVT at three stroke centers in Korea. We compared the characteristics of patients with and without AKI and independent factors associated with AKI after EVT. We also investigated the effects of AKI on functional outcomes and mortality at 3 months. Of the 601 patients analyzed, 59 patients (9.8%) developed AKI and five patients (0.8%) started renal replacement therapy after EVT. In the multivariate analysis, diabetes mellitus (odds ratio (OR), 2.341; 95% CI, 1.283–4.269; p = 0.005), the contrast agent dose (OR, 1.107 per 10 mL; 95% CI, 1.032–1.187; p = 0.004), and unsuccessful reperfusion (OR, 1.909; 95% CI, 1.019–3.520; p = 0.040) were independently associated with AKI. The presence of AKI was associated with a poor functional outcome (OR, 5.145; 95% CI, 2.177–13.850; p < 0.001) and mortality (OR, 8.164; 95% CI, 4.046–16.709; p < 0.001) at 3 months. AKI may also affect the outcomes of ischemic stroke patients undergoing EVT. When implementing EVT, practitioners should be aware of these risk factors.
Influence of a Lubricating Gel (Orthospeed®) on Pain and Oral Health-Related Quality of Life in Orthodontic Patients during Initial Therapy with Conventional and Low-Friction Brackets: A Prospective Randomized Clinical Trial
Authors: Curto Adrian , Albaladejo Alberto , Montero Javier , Alvarado Alfonso
Published: May 2020

The aim of this study was to investigate whether statistically significant differences exist regarding pain and the impact on oral quality of life of orthodontic treatment. A conventional brackets system was compared with low-friction brackets. A total of 90 patients (male = 35, female = 55) were chosen for this randomized clinical trial. Pain was assessed at 4, 8, and 24 hours and 2, 3, 4, 5, 6, and 7 days after the start of treatment using the McGill Pain Questionnaire. Oral health-related quality of life (OHRQoL) was assessed using the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Oral quality of life was assessed at one month, with patients with low-friction brackets describing lower levels of pain. The patients with conventional brackets indicated a worse impact on their quality of life compared to the group with low-friction brackets. Statistically significant differences were found between the groups, with maximum pain observed between the first 24 and 48 hours, and the values of minimum pain are reached after 7 days. The pain and impact on oral quality of life was statistically worse in patients with conventional brackets compared to patients with low-friction brackets. The type of bracket system used was therefore shown to influence patients’ perceptions of pain and impact on their OHRQoL.
Use of Biosimilar Follicle-Stimulating Hormone in Asthenozoospermic Infertile Patients: A Multicentric Study
Authors: De Rocco Ponce Maurizio , Foresta Carlo , Rago Rocco , Dal Lago Alessandro , Balercia Giancarlo , Calogero Aldo Eugenio , La Vignera Sandro , Cosci Ilaria , Di Nisio Andrea , Garolla Andrea
Published: May 2020

There is increasing data in favour of follicle-stimulating hormone (FSH) therapy in patients with oligo-asthenozoospermia and normal-range gonadotropins in order to increase sperm count and above all sperm motility. Some studies showed an improvement in DNA fragmentation and spontaneous pregnancy. Recently, biosimilar FSH has been marketed with the same indications. We performed a retrospective multicentric case-control study involving 147 asthenozoospermic patients between 18 and 45 years of age. A total of 97 patients were treated with biosimilar FSH 150 UI three times a week for 3 months, while 50 control subjects received no treatment. Patients were evaluated at baseline and after 3 months with semen analysis including DNA fragmentation, testicular colour Doppler ultrasound, and blood tests. Spontaneous pregnancies were recorded during a further follow-up period of 6 months. Treated patients showed after treatment a statistically significant increase in sperm concentration, total sperm count, and total motile sperm, as well as improved progressive motility and non-progressive motility. DNA fragmentation showed a significant reduction. Conversely, in the control group, no significant change was found. Pregnancy rate was significantly higher in treated patients. These data suggest comparable efficacy of biosimilar FSH in the treatment of male infertility; however, larger studies are needed to confirm our results.
Measurement of Tongue Tip Velocity from Real-Time MRI and Phase-Contrast Cine-MRI in Consonant Production
Authors: Isaieva Karyna , Laprie Yves , Odille Freddy , Douros Ioannis K. , Felblinger Jacques , Vuissoz Pierre-André
Published: May 2020

We evaluate velocity of the tongue tip with magnetic resonance imaging (MRI) using two independent approaches. The first one consists in acquisition with a real-time technique in the mid-sagittal plane. Tracking of the tongue tip manually and with a computer vision method allows its trajectory to be found and the velocity to be calculated as the derivative of the coordinate. We also propose to use another approach—phase contrast MRI—which enables velocities of the moving tissues to be measured directly. We recorded the sound simultaneously with the MR acquisition which enabled us to make conclusions regarding the relation between the movements and the sound. We acquired the data from two French-speaking subjects articulating /tata/. The results of both methods are in qualitative agreement and are consistent with other reviewer techniques used for evaluation of the tongue tip velocity.
The Acquisition of Mandarin Consonants by English Learners: The Relationship between Perception and Production
Authors: Wang Xinchun , Chen Jidong
Published: May 2020

This study investigates native English CFL (Chinese as a Foreign Language) learners’ difficulties with Mandarin consonants at the initial stage of learning and explores the relationship between second language (L2) speech perception and production. Twenty-five native English CFL learners read the eight Mandarin consonants (j/tɕ/, q /tɕʰ/, x /ɕ/, zh /tʂ/, ch /tʂʰ/, sh /ʂ/, z /ts/, and c /tsʰ/) in sentences and identified the target sounds in a forced-choice identification task. Native Mandarin listeners identified the consonants produced by the learners and rated the quality of each sound they identified along a scale of 1 (poor) to 7 (good). The learners’ mean percentage accuracy scores ranged from 29% to 80% for perception and 25% to 88% for production. Moderate correlations between the perception and production scores were found for two of the eight target sounds. The Mandarin retroflex, palatal, and dental fricatives and affricates, though all lack counterparts in English, pose different problems to the English CFL learners. The misperceived retroflex and palatal sounds were substituted with each other in perception but mis-produced palatal sounds were substituted with each other, not with retroflex sounds. The relationship between perception and production of L2 consonants is not straightforward. The findings are discussed in terms of current speech learning models.
Some Hard or Soft Coatings to Protect the Pristine Biometallic Substrates under Fretting-Corrosion Solicitations: What Should Be the Best Solution?
Authors: Geringer Jean , Fridrici Vincent , Ding Haohao , Kim Kyungmok , Taylor T. , Semetse Lerato , Ehsani-Majd Sara , Olubambi Peter , Fontaine Julien , Kapsa Philippe
Published: May 2020

Under tribological conditions in aqueous medium, the contact of materials does involve some degradations of materials. Especially friction under small reciprocal displacement, i.e., fretting corrosion, is occurring; this topic has been highlighted since the 80′s regarding hip implants. Hip prosthesis is assembled from three parts: femoral stem, neck and head. Fretting corrosion or friction corrosion between metallic parts first involves some degradation of the oxides layers. This step is governed by mechanics and it is related to some few minutes. Afterwards the corrosion occurrs enhanced by mechanical degradation. As well focused some oxides and some metallic ions are related to biocompatibility issues. Some strategies are available in order to avoid metal against metal friction and/or fretting. Some hard coatings and some smooth coatings were investigated. The first one is diamond-like carbon (DLC), and the second is a polyetheretherketone (PEEK), polymeric one. The investigations were focused on fretting corrosion solicitations of Ti-6Al-4V vs. Ti-6Al-4V + coating. DLC as a coating delays the corrosion degradation. The PEEK coating does not promote any corrosion degradation of the metallic counter part and more generally any wear.
Investigation of the Fracture Process of Explosively Welded AA2519–AA1050–Ti6Al4V Layered Material
Authors: Boroński Dariusz , Dzioba Ihor , Kotyk Maciej , Krampikowska Aleksandra , Pała Robert
Published: May 2020

The study presents an analysis of the cracking process of explosive welded layered material AA2519–AA1050–Ti6Al4V (Al–Ti laminate) at ambient (293 K) and reduced (223 and 77 K) temperatures. Fracture toughness tests were conducted for specimens made of base materials and Al–Ti laminate. As a result of loading, delamination cracking occurred in the bonding layer of specimens made from Al–Ti laminate. To define the crack mechanisms that occur at the tested temperatures, a fracture analysis was made using a scanning electron microscope. Moreover, acoustic emission (AE) signals were recorded while loading. AE signals were segregated to link their groups with respective cracking process mechanisms. Numerical models of the tested specimens were developed, taking into account the complexity of the laminate structure and the ambiguity of the cracking process. A load simulation using the finite element method FEM allowed calculating stress distributions in the local area in the crack tip of the Al–Ti laminate specimens, which enabled the explanation of significant material cracking process development aspects. Results analysis showed an influence of interlayer delamination crack growth on the process of the Al–Ti laminate specimen cracking and the level of KQ characteristics at different temperatures.
Influence of W Addition on Phase Constitution, Microstructure and Magnetic Properties of the Nanocrystalline Pr9Fe65WxB26-x (Where: x = 2, 4, 6, 8) Alloy Ribbons
Authors: Filipecka Katarzyna , Pawlik Piotr , Kozdraś Andrzej , Kaszuwara Waldemar , Ferenc Jarosław , Filipecki Jacek
Published: May 2020

The aim of the present work was to investigate an influence of W addition on the phase constitution, microstructure and magnetic properties of the Pr9Fe65WxB26-x (where: x = 2, 4, 6, 8) alloy ribbons. Ribbons were obtained using the melt-spinning technique under low pressure of Ar. The as-cast samples were fully amorphous and revealed soft magnetic properties. These facts were confirmed by X-ray diffractometry, Mössbauer spectroscopy and magnetic measurements. Differential scanning calorimetry and differential thermal analysis allowed us to determine the thermal stability parameters of the amorphous phase. The Kissinger plots were constructed in order to calculate the activation energies for crystallization. Heat treatment carried out at various temperatures caused changes in the phase constitution and magnetic properties of the alloys. The phase analysis has shown the presence of the hard magnetic Pr2Fe14B and paramagnetic Pr1+xFe4B4 phases. Additionally, for the x = 2 and x = 6 alloys, a crystallization of soft magnetic Fe2B and α-Fe phases was observed. The Mössbauer spectroscopy allowed us to determine the volume fractions of constituent phases formed during annealing. The microstructure of annealed ribbons was observed using transmission electron microscopy.
Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application
Authors: Tonello Sarah , Bianchetti Andrea , Braga Simona , Almici Camillo , Marini Mirella , Piovani Giovanna , Guindani Michele , Dey Kamol , Sartore Luciana , Re Federica , Russo Domenico , Cantù Edoardo , Francesco Lopomo Nicola , Serpelloni Mauro , Sardini Emilio
Published: May 2020

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and −9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.
Effect of Imposed Shear Strain on Steel Ring Surfaces during Milling in High-Speed Disintegrator
Authors: Dvořák Karel , Macháčková Adéla , Ravaszová Simona , Gazdič Dominik
Published: May 2020

This contribution characterizes the performance of a DESI 11 high-speed disintegrator working on the principle of a pin mill with two opposite counter-rotating rotors. As the ground material, batches of Portland cement featuring 6–7 Mohs scale hardness and containing relatively hard and abrasive compounds with the specific surface areas ranging from 200 to 500 m2/kg, with the step of 50 m2/kg, were used. The character of the ground particles was assessed via scanning electron microscopy and measurement of the absolute/relative increase in their specific surface areas. Detailed characterization of the rotors was performed via recording the thermal imprints, evaluating their wear by 3D optical microscopy, and measuring rotor weight loss after the grinding of constant amounts of cement. The results showed that coarse particles are ground by impacting the front faces of the pins, while finer particles are primarily milled via mutual collisions. Therefore, the coarse particles cause higher abrasion and wear on the rotor pins; after the milling of 20 kg of the 200 m2/kg cement sample, the wear of the rotor reached up to 5% of its original mass and the pins were severely damaged.
Pressure Effects on the Magnetic Phase Diagram of the CeNMSb2 (NM: Au and Ag): A DFT Study
Authors: Alsardia Mowafaq Mohammad , Jang Jaekyung , Rhee Joo Yull
Published: May 2020

We explore the influence of pressure on the magnetic ground state of the heavy-fermion antiferromagnet (ferromagnet) CeAuSb 2 (CeAgSb 2 ) using first-principles calculations. The total-energy differences obtained by including the spin-orbit interactions and the on-site Coulomb potential for the Ce-derived 4f-orbitals are necessary to realize the accurate magnetic ground state of CeNMSb 2 (NM: Au and Ag). According to our results, the appearance of a new magnetic phase of CeAuSb 2 (CeAgSb 2 ) at the pressure of 2.1 GPa (3.5 GPa) is due to the rotation of the magnetic easy axis from the <001> to the <100> direction. Additionally, our data confirm that CeAgSb 2 is antiferromagnetic (AFM) above a critical pressure P c , and such a tendency is expected for CeAuSb 2 and remains to be seen. Through the spin-orbit-coupling Hamiltonian and detailed information on the occupation of individual 4f-orbitals of the Ce atom obtained by the electronic-structure calculations, we can deduce the rotation of the magnetic easy axis upon the application of pressure. According to the present and previous studies, the differences among the magnetic properties of CeNMSb 2 (NM: Cu, Ag and Au) compounds are not due to the different noble metals, but due to the subtle differences in the relative position of Ce atoms and, in turn, different occupations of Ce 4f-orbitals.
Effect of Twin Boundary Motion and Dislocation-Twin Interaction on Mechanical Behavior in Fcc Metals
Authors: Rezaei Mianroodi Jaber , Svendsen Bob
Published: May 2020

The interplay of interface and bulk dislocation nucleation and glide in determining the motion of twin boundaries, slip-twin interaction, and the mechanical (i.e., stress-strain) behavior of fcc metals is investigated in the current work with the help of molecular dynamics simulations. To this end, simulation cells containing twin boundaries are subject to loading in different directions relative to the twin boundary orientation. In particular, shear loading of the twin boundary results in significantly different behavior than in the other loading cases, and in particular to jerky stress flow. For example, twin boundary shear loading along ⟨ 112 ⟩ results in translational normal twin boundary motion, twinning or detwinning, and net hardening. On the other hand, such loading along ⟨ 110 ⟩ results in oscillatory normal twin boundary motion and no hardening. As shown here, this difference results from the different effect each type of loading has on lattice stacking order perpendicular to the twin boundary, and so on interface partial dislocation nucleation. In both cases, however, the observed stress fluctuation and “jerky flow” is due to fast partial dislocation nucleation and glide on the twin boundary. This is supported by the determination of the velocity and energy barriers to glide for twin boundary partials. In particular, twin boundary partial edge dislocations are significantly faster than corresponding screws as well as their bulk counterparts. In the last part of the work, the effect of variable twin boundary orientation in relation to the loading direction is investigated. In particular, a change away from pure normal loading to the twin plane toward mixed shear-normal loading results in a transition of dominant deformation mechanism from bulk dislocation nucleation/slip, to twin boundary motion.
A Combined Cold Extrusion for a Drive Shaft: A Parametric Study on Tool Geometry
Authors: Ku Tae-Wan
Published: May 2020

Parametric investigations related to shoulder angle on tool geometry for a combined cold extrusion of a drive shaft, which consisted of spur gear and internal spline structures, were conducted through three-dimensional FE (finite element) simulations. The drive shaft was required to be about 92.00 mm for the face width of the top land on the spur gear part and roughly 22.70 mm for the groove depth of the internal spline section. AISI 1035 carbon steel material with a diameter of 50.00 mm and a length of 121.00 mm was spheroidized and annealed, then used as the initial billet material. A preform as an intermediate workpiece was adopted to avoid the excessive accumulation of plastic deformation during the combined cold extrusion. Accordingly, the cold forging process involves two extrusion operations such as a forward extrusion and a combined extrusion for the preform and the drive shaft. As the main geometric parameters influencing the dimensional quality and the deformed configuration of the final product, the two shoulder angles of θ1 and θ2 for the preform forging and the combined extrusion were both considered to be appropriate at 30°, 45°, and 60°, respectively. Using nine geometric parameter combinations, three-dimensional finite element simulations were performed, and these were used to evaluate the deformed features and the geometric compatibilities on the spur gear structure and the internal spline feature. Based on these comparative evaluations using the numerically simulated results, it is shown that the dimensional requirements of the target shape can be satisfied with the shoulder angle combination of (45°, 45°) for (θ1, θ2).
The Influence of Calcareous Fly Ash on the Effectiveness of Plasticizers and Superplasticizers
Authors: Gołaszewski Jacek , Ponikiewski Tomasz , Kostrzanowska-Siedlarz Aleksandra , Miera Patrycja
Published: May 2020

Due to the rational shaping of the environment and the management of environmental resources in accordance with the principle of sustainable development, calcareous fly ash (CFA)—high-calcium as a by-product of lignite combustion—is a valuable addition to concrete. This additive, however, due to its high-water demand lowers the workability of the concrete mix, which is a problem, especially in the first 90 min after mixing the components of the mix. In order to meet this challenge, plasticizers (P) and superplasticizers (SP) for concrete are used with various effects which are designed to reduce the yield value and plastic viscosity. To check the technical efficiency of admixtures P and SP with different chemical bases, the main objective of this research was to investigate the influence of raw and ground CFA on the rheological properties and other side effects of admixtures, such as the amount of air in the mixture and the amount of heat of hydration. The use of P, particularly SP, effectively improves the workability of the mortar containing CFA, especially ground CFA. With these admixtures, it is possible to obtain mortars containing ground CFA with similar rheological properties to mortars without its addition. To obtain a specific workability of mortar with CFA, it is usually necessary to introduce a higher dose of P or SP than used for mortars without CFA. The presence of raw CFA does not alter the effectiveness of P and strongly reduces the effectiveness of SP. The reduced effectiveness of SP manifests primarily as a high workability lost. The presence of ground CFA does not change the effectiveness of P (or is higher). The effectiveness of the superplasticizer SNF (with a chemical base of naphthalene sulfonate) and PE (with a chemical base of polycarboxylate ether) is slightly lower or does not change. The effectiveness of the superplasticizer SMF (with a chemical base of melamine sulfonates) is significantly lower. We found that the presence of ash affects the efficiency of P and SP, while processing via the grinding of ash makes the effect negligible. These results are novel in both their cognitive and practical aspects.
RGD-Dendrimer-Poly(L-lactic) Acid Nanopatterned Substrates for the Early Chondrogenesis of Human Mesenchymal Stromal Cells Derived from Osteoarthritic and Healthy Donors
Authors: Rodríguez-Pereira Cristina , Lagunas Anna , Casanellas Ignasi , Vida Yolanda , Pérez-Inestrosa Ezequiel , Andrades José A. , Becerra José , Samitier Josep , Blanco Francisco J. , Magalhães Joana
Published: May 2020

Aiming to address a stable chondrogenesis derived from mesenchymal stromal cells (MSCs) to be applied in cartilage repair strategies at the onset of osteoarthritis (OA), we analyzed the effect of arginine–glycine–aspartate (RGD) density on cell condensation that occurs during the initial phase of chondrogenesis. For this, we seeded MSC-derived from OA and healthy (H) donors in RGD-dendrimer-poly(L-lactic) acid (PLLA) nanopatterned substrates (RGD concentrations of 4 × 10−9, 10−8, 2.5 × 10−8, and 10−2 w/w), during three days and compared to a cell pellet conventional three-dimensional culture system. Molecular gene expression (collagens type-I and II–COL1A1 and COL2A1, tenascin-TNC, sex determining region Y-box9-SOX9, and gap junction protein alpha 1–GJA1) was determined as well as the cell aggregates and pellet size, collagen type-II and connexin 43 proteins synthesis. This study showed that RGD-tailored first generation dendrimer (RGD-Cys-D1) PLLA nanopatterned substrates supported the formation of pre-chondrogenic condensates from OA- and H-derived human bone marrow-MSCs with enhanced chondrogenesis regarding the cell pellet conventional system (presence of collagen type-II and connexin 43, both at the gene and protein level). A RGD-density dependent trend was observed for aggregates size, in concordance with previous studies. Moreover, the nanopatterns’ had a higher effect on OA-derived MSC morphology, leading to the formation of bigger and more compact aggregates with improved expression of early chondrogenic markers.
Effect of Scan Strategies and Use of Support Structures on Surface Quality and Hardness of L-PBF AlSi10Mg Parts
Authors: Gouveia Ronny M. , Silva Francisco J. G. , Atzeni Eleonora , Sormaz Dušan , Alves Jorge Lino , Pereira António Bastos
Published: May 2020

Additive manufacturing allows for a great degree of design freedom and is rapidly becoming a mainstream manufacturing process. However, as in all manufacturing processes, it has its limitations and specificities. Equipping engineers with this knowledge allows for a higher degree of optimization, extracting the most out of this technology. Therefore, a specific part design was devised and created via L-PBF (Laser Powder Bed Fusion) using AlSi10Mg powder. Certain parameters were varied to identify the influence on material density, hardness, roughness, residual stress and microstructures. It was found that on heat treated parts laser pattern strategy is one of the most influential aspects, showing that chessboard and stripes 67° improved outcome; average Ra roughness varied between 8–12 µm, residual stress was higher on vertical surfaces than horizontal surfaces, with the combination of support structures and stripes 67° strategies generating the lowest residual stress (205 MPa on a lateral/vertical face), hardness was non-orientation dependent and larger on samples with chessboard fabrication strategies, while microstructures were composed of α–Al dendrites surrounded by Si particles. The distribution and grain size of the microstructure is dependent on location regarding melt pool and HAZ area. Furthermore, Al–Mg oxides were encountered on the surface, along with pores generating from lack of fusion.
Hybrid Fiber Optic Sensor Systems in Structural Health Monitoring in Aircraft Structures
Authors: Bednarska Karolina , Sobotka Piotr , Woliński Tomasz Ryszard , Zakręcka Oliwia , Pomianek Wiktor , Nocoń Agnieszka , Lesiak Piotr
Published: May 2020

‘Smart’ structural health monitoring of composite materials with optical fiber sensors is becoming more and more important, especially in the aviation industry. This paper presents an overview of hybrid fiber-optic sensing systems based on scattering techniques, fiber Bragg gratings, interferometric techniques, and polarimetric methods in structural health monitoring. The main purpose of this manuscript is to analyze the possibilities of using hybrid sensors based on fiber optics to monitor composite structures, with a particular emphasis on aircraft structures. Since it is difficult to indicate the most comprehensive approach due to different parameters of the described sensors, the review contains a detailed description of available solutions. We hope that this work will allow for a better and faster selection of the right solution for the problem at hand.
Graphene-Modified Composites and Electrodes and Their Potential Applications in the Electro-Fenton Process
Authors: Yu Tian , Breslin Carmel B.
Published: May 2020

In recent years, graphene-based materials have been identified as an emerging and promising new material in electro-Fenton, with the potential to form highly efficient metal-free catalysts that can be employed in the removal of contaminants from water, conserving precious water resources. In this review, the recent applications of graphene-based materials in electro-Fenton are described and discussed. Initially, homogenous and heterogenous electro-Fenton methods are briefly introduced, highlighting the importance of the generation of H2O2 from the two-electron reduction of dissolved oxygen and its catalysed decomposition to produce reactive and oxidising hydroxy radicals. Next, the promising applications of graphene-based electrodes in promoting this two-electron oxygen reduction reaction are considered and this is followed by an account of the various graphene-based materials that have been used successfully to give highly efficient graphene-based cathodes in electro-Fenton. In particular, graphene-based composites that have been combined with other carbonaceous materials, doped with nitrogen, formed as highly porous aerogels, three-dimensional materials and porous gas diffusion electrodes, used as supports for iron oxides and functionalised with ferrocene and employed in the more effective heterogeneous electro-Fenton, are all reviewed. It is perfectly clear that graphene-based materials have the potential to degrade and mineralise dyes, pharmaceutical compounds, antibiotics, phenolic compounds and show tremendous potential in electro-Fenton and other advanced oxidation processes.