bluuebunny/crossref_metadata_2025 huggingface dataset:
Distinct TP53 Mutation Types Exhibit Increased Sensitivity to Ferroptosis Independently of Changes in Iron Regulatory Protein Activity
Authors: Thompson Laurie R. , Oliveira Thais G. , Hermann Evan R. , Chowanadisai Winyoo , Clarke Stephen L. , Montgomery McKale R.
Published: September 2020

The tumor suppressor gene TP53 is the most commonly mutated gene in human cancer. In addition to loss of tumor suppressor functions, mutations in TP53 promote cancer progression by altering cellular iron acquisition and metabolism. A newly identified role for TP53 in the coordination of iron homeostasis and cancer cell survival lies in the ability for TP53 to protect against ferroptosis, a form of iron-mediated cell death. The purpose of this study was to determine the extent to which TP53 mutation status affects the cellular response to ferroptosis induction. Using H1299 cells, which are null for TP53, we generated cell lines expressing either a tetracycline inducible wild-type (WT) TP53 gene, or a representative mutated TP53 gene from six exemplary “hotspot” mutations in the DNA binding domain (R273H, R248Q, R282W, R175H, G245S, and R249S). TP53 mutants (R273H, R248Q, R175H, G245S, and R249S) exhibited increased sensitivity ferroptosis compared to cells expressing WT TP53. As iron-mediated lipid peroxidation is critical for ferroptosis induction, we hypothesized that iron acquisition pathways would be upregulated in mutant TP53-expressing cells. However, only cells expressing the R248Q, R175H, and G245S TP53 mutation types exhibited statistically significant increases in spontaneous iron regulatory protein (IRP) RNA binding activity following ferroptosis activation. Moreover, changes in the expression of downstream IRP targets were inconsistent with the observed differences in sensitivity to ferroptosis. These findings reveal that canonical iron regulatory pathways are bypassed during ferroptotic cell death. These results also indicate that induction of ferroptosis may be an effective therapeutic approach for tumor cells expressing distinct TP53 mutation types.
The Exo-Polysaccharide Component of Extracellular Matrix is Essential for the Viscoelastic Properties of Bacillus subtilis Biofilms
Authors: Pandit Santosh , Fazilati Mina , Gaska Karolina , Derouiche Abderahmane , Nypelö Tiina , Mijakovic Ivan , Kádár Roland
Published: September 2020

Bacteria are known to form biofilms on various surfaces. Biofilms are multicellular aggregates, held together by an extracellular matrix, which is composed of biological polymers. Three principal components of the biofilm matrix are exopolysaccharides (EPS), proteins, and nucleic acids. The biofilm matrix is essential for biofilms to remain organized under mechanical stress. Thanks to their polymeric nature, biofilms exhibit both elastic and viscous mechanical characteristics; therefore, an accurate mechanical description needs to take into account their viscoelastic nature. Their viscoelastic properties, including during their growth dynamics, are crucial for biofilm survival in many environments, particularly during infection processes. How changes in the composition of the biofilm matrix affect viscoelasticity has not been thoroughly investigated. In this study, we used interfacial rheology to study the contribution of the EPS component of the matrix to viscoelasticity of Bacillus subtilis biofilms. Two strategies were used to specifically deplete the EPS component of the biofilm matrix, namely (i) treatment with sub-lethal doses of vitamin C and (ii) seamless inactivation of the eps operon responsible for biosynthesis of the EPS. In both cases, the obtained results suggest that the EPS component of the matrix is essential for maintaining the viscoelastic properties of bacterial biofilms during their growth. If the EPS component of the matrix is depleted, the mechanical stability of biofilms is compromised and the biofilms become more susceptible to eradication by mechanical stress.
Prevention of Rat Intestinal Injury with a Drug Combination of Melatonin and Misoprostol
Authors: Dahlgren David , Cano-Cebrián Maria-José , Hellström Per M. , Wanders Alkwin , Sjöblom Markus , Lennernäs Hans
Published: September 2020

A healthy intestinal barrier prevents uptake of allergens and toxins, whereas intestinal permeability increases following chemotherapy and in many gastrointestinal and systemic diseases and disorders. Currently, there are no approved drugs that target and repair the intestinal epithelial barrier while there is a medical need for such treatment in gastrointestinal and related conditions. The objective of this single-pass intestinal perfusion study in rats was to investigate the preventive cytoprotective effect of three mucosal protective drugs—melatonin, misoprostol, and teduglutide—with different mechanisms of action on an acute jejunal injury induced by exposing the intestine for 15 min to the anionic surfactant, sodium dodecyl sulfate (SDS). The effect was evaluated by monitoring intestinal clearance of 51Cr-labeled ethylenediaminetetraacetate and intestinal histology before, during, and after luminal exposure to SDS. Our results showed that separate pharmacological pretreatments with luminal misoprostol and melatonin reduced acute SDS-induced intestinal injury by 47% and 58%, respectively, while their use in combination abolished this injury. This data supports further development of drug combinations for oral treatments of conditions and disorders related to a dysregulated or compromised mucosal epithelial barrier.
Water Costs of Gas Exchange by a Speckled Cockroach and a Darkling Beetle
Authors: Abbas Waseem , Withers Philip C. , Evans Theodore A.
Published: September 2020

Respiratory water loss during metabolic gas exchange is an unavoidable cost of living for terrestrial insects. It has been suggested to depend on several factors, such as the mode of gas exchange (convective vs. diffusive), species habitat (aridity), body size and measurement conditions (temperature). We measured this cost in terms of respiratory water loss relative to metabolic rate (respiratory water cost of gas exchange; RWL/V˙CO2) for adults of two insect species, the speckled cockroach (Nauphoeta cinerea) and the darkling beetle (Zophobas morio), which are similar in their mode of gas exchange (dominantly convective), habitat (mesic), body size and measurement conditions, by measuring gas exchange patterns using flow-through respirometry. The speckled cockroaches showed both continuous and discontinuous gas exchange patterns, which had significantly a different metabolic rate and respiratory water loss but the same respiratory water cost of gas exchange. The darkling beetles showed continuous gas exchange pattern only, and their metabolic rate, respiratory water loss and respiratory cost of gas exchange were equivalent to those cockroaches using continuous gas exchange. This outcome from our study highlights that the respiratory water cost of gas exchange is similar between species, regardless of gas exchange pattern used, when the confounding factors affecting this cost are controlled. However, the total evaporative water cost of gas exchange is much higher than the respiratory cost because cuticular water loss contributes considerably more to the overall evaporative water loss than respiratory water. We suggest that the total water cost of gas exchange is likely to be a more useful index of environmental adaptation (e.g., aridity) than just the respiratory water cost.
Potato Tuberworm Phthorimaea operculella (Zeller) (Lepidoptera: Gelechioidea) Leaf Infestation Affects Performance of Conspecific Larvae on Harvested Tubers by Inducing Chemical Defenses
Authors: Wang Dingli , Wang Qiyun , Sun Xiao , Gao Yulin , Ding Jianqing
Published: September 2020

Conspecific aboveground and belowground herbivores can interact with each other, mediated by plant secondary chemicals; however, little attention has been paid to the interaction between leaf feeders and tuber-feeders. Here, we evaluated the effect of the foliar feeding of P. operculella larvae on the development of conspecific larvae feeding on harvested tubers by determining the nutrition and defense metabolites in the whole plant (leaf, root and tuber). We found that leaf feeding negatively affected tuber larval performance by increasing the female larval developmental time and reducing the male pupal weight. In addition, aboveground herbivory increased α-chaconine and glycoalkaloids in tubers and α-solanine in leaves, but decreased α-chaconine and glycoalkaloids in leaves. Aboveground herbivory also altered the levels of soluble sugar, soluble protein, starch, carbon (C), nitrogen (N), as well as the C:N ratio in both leaves and tubers. Aboveground P. operculella infestations could affect the performance of conspecific larvae feeding on harvested tubers by inducing glycoalkaloids in the host plant. Our findings indicate that field leaf herbivory should be considered when assessing the quality of potato tubers and their responses to pests during storage.
A Solar-Powered IoT Connected Physical Mailbox Interfaced with Smart Devices
Authors: Khan Tareq
Published: September 2020

In this age of electronic communication, checking the physical mailbox is still part of our daily life. Mailboxes are placed several meters away from the house, and sometimes across the opposite side of a street. It is annoying to walk to the mailbox each day and realize that the mailbox is empty. In this paper, an Internet of Things (IoT)-connected smart mailbox is developed that automatically sends a notification to the smartphone whenever new mail arrives. This notification removes the frustration of an unnecessary trip to the mailbox. The proposed mailbox contains a low power device comprising of sensors, a system-on-chip microcontroller with Bluetooth Low Energy (BLE), and a rechargeable battery that charges with a solar panel. Whenever the mailbox door is closed, it checks the presence of mail and then sends the data to a hub using BLE. The hub is placed inside the house and sends a push notification to the smartphone using the home Wi-Fi. A smart speaker, Google Home, is also interfaced with the system, which can verbally say the status of the mailbox when asked a customized question. A prototype of the smart mailbox, the hub, and the smartphone app is developed and tested successfully.
Epithelial Ovarian Cancer and the Immune System: Biology, Interactions, Challenges and Potential Advances for Immunotherapy
Authors: Macpherson Anne M. , Barry Simon C. , Ricciardelli Carmela , Oehler Martin K.
Published: September 2020

Recent advances in the understanding of immune function and the interactions with tumour cells have led to the development of various cancer immunotherapies and strategies for specific cancer types. However, despite some stunning successes with some malignancies such as melanomas and lung cancer, most patients receive little or no benefit from immunotherapy, which has been attributed to the tumour microenvironment and immune evasion. Although the US Food and Drug Administration have approved immunotherapies for some cancers, to date, only the anti-angiogenic antibody bevacizumab is approved for the treatment of epithelial ovarian cancer. Immunotherapeutic strategies for ovarian cancer are still under development and being tested in numerous clinical trials. A detailed understanding of the interactions between cancer and the immune system is vital for optimisation of immunotherapies either alone or when combined with chemotherapy and other therapies. This article, in two main parts, provides an overview of: (1) components of the normal immune system and current knowledge regarding tumour immunology, biology and their interactions; (2) strategies, and targets, together with challenges and potential innovative approaches for cancer immunotherapy, with attention given to epithelial ovarian cancer.
Prognostic Impact of Sarcopenic Obesity after Neoadjuvant Chemotherapy Followed by Surgery in Elderly Patients with Esophageal Squamous Cell Carcinoma
Authors: Onishi Sachiyo , Tajika Masahiro , Tanaka Tsutomu , Yamada Keisaku , Abe Tetsuya , Higaki Eiji , Hosoi Takahiro , Inaba Yoshitaka , Muro Kei , Shimizu Masahito , Niwa Yasumasa
Published: September 2020

We evaluated the impact of body composition on clinical outcomes after neoadjuvant chemotherapy (NAC) followed by surgery for elderly cStage II/III esophageal squamous cell carcinoma (ESCC). Ninety-one patients ≥70 years old and 116 patients <70 years old with ECSS who underwent NAC between January 2013 and June 2018 at the Aichi Cancer Center were included. Body composition as assessed from computed tomography (CT), American Society of Anesthesiologists physical status (ASA-PS), and subjective global assessment (SGA) was assessed before initiation of NAC. Although elderly patients showed significantly poorer ASA-PS (p < 0.01) and SGA (p < 0.01), and significantly more frequent history of malignancy (p < 0.05), no significant differences were identified in the frequencies of adverse events, postoperative complications, or in cancer-specific survival (p = 0.65, hazard ratio 1.15), or overall survival (p = 0.42, hazard ratio 1.26). However, multivariate analysis identified sarcopenic obesity as the only independent predictor of prognosis in elderly patients. Sarcopenic obesity was associated with higher body mass index (p = 0.04), better SGA (p < 0.01), and lower pre-treatment weight loss (p = 0.03). NAC was as effective and safe for elderly patients without sarcopenic obesity as for young patients. However, diagnosing sarcopenic obesity based on clinical findings is difficult, so the preoperative CT assessment of sarcopenic obesity is important.
Early Psychological Impact of the COVID-19 Pandemic in Brazil: A National Survey
Authors: Campos Juliana Alvares Duarte Bonini , Martins Bianca Gonzalez , Campos Lucas Arrais , Marôco João , Saadiq Rayya Ahmed , Ruano Rodrigo
Published: September 2020

Background: Isolation measures used to contain epidemics generate social interaction restrictions and impose changes in routines of the public that increase negative psychological outcomes. Anxiety and depression are the most common symptoms. Objective: To evaluate the mental health of the Brazilian population during the SARs-CoV-2 pandemic and its relationship with demographic and health characteristics. Methods: Adults from all Brazilian States participated (n = 12,196; women: 69.8%, mean age = 35.2 years). The Depression, Anxiety and Stress Scale, and the Impact of Event Scale–revised were used (online survey). Data validity and reliability were verified by confirmatory factor analysis and ordinal alpha coefficient. The probability of presenting psychological symptoms was calculated by multiple logistic regression and odds ratio (OR) (0 = without symptoms, 1 = with mild, moderate, and severe levels of symptoms). Results: High prevalence of depression (61.3%), anxiety (44.2%), stress (50.8%), and psychological impact (54.9%) due to the isolation experienced from the pandemic was found. Younger individuals (OR = 1.58–3.58), those that felt unsafe (OR = 1.75–2.92), with a previous diagnosis of mental health (OR = 1.72–2.64) and/or had general health problems before the pandemic (OR = 1.17–1.51), who noticed changes in their mental state due to the pandemic context (OR = 2.53–9.07), and excessively exposed to the news (OR = 1.19–2.18) were at increased risk of developing symptoms. Women (OR = 1.35–1.65) and those with lower economic status (OR = 1.38–2.69) were more likely to develop psychological symptoms. Lower educational levels increased the likelihood of depressive (OR = 1.03–1.34) and intrusive symptoms (OR = 1.09–1.51). Conclusions: The pandemic and related factors can have a high impact on the mental health of the population. Demographic characteristics can influence the occurrence of psychological symptoms.
Atherogenic Index of Plasma Is a Potential Biomarker for Severe Acute Pancreatitis: A Prospective Observational Study
Authors: Cho Seung Kook , Kim Jae Woo , Huh Ji Hye , Lee Kyong Joo
Published: September 2020

Background: The atherogenic index of plasma (AIP) reflects the levels of triglycerides (TG) and high-density lipoprotein (HDL) cholesterol. The purpose of this study was to assess the relationship between the AIP and severe acute pancreatitis (SAP). Materials and methods: Patients with acute pancreatitis (AP) were prospectively enrolled from March 2015 to June 2019. The severity of AP was classified according to the 2012 revised Atlanta classification. Mild and moderately severe AP were categorized as non-SAP. The AIP is calculated as log(TG/HDL). Results: A total of 323 patients were enrolled. The etiologies of AP were gallstone in 171 patients (52.9%), alcohol in 122 patients (37.8%), and hypertriglyceridemia in 30 patients (9.3%). Twenty-four patients (7.4%) were classified as SAP. The AIP was significantly higher in the SAP group compared to the non-SAP group (p < 0.001). The AIP was positively correlated with the Atlanta classification (R = 0.256, p < 0.001). In multivariate analysis, the AIP was found to be an independent predictive factor for SAP (OR = 4.571; CI = 1.913–10.922; p = 0.001). Conclusions: The AIP is a potential biomarker for the prediction of SAP in clinical practice. This result provides that impaired lipid metabolism is associated with the severity of pancreatitis.
De-Escalation of Antiplatelet Treatment in Patients with Myocardial Infarction Who Underwent Percutaneous Coronary Intervention: A Review of the Current Literature
Authors: Claassens Daniel MF , Sibbing Dirk
Published: September 2020

In acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI), treatment with the P2Y12 inhibitors ticagrelor or prasugrel is recommended over clopidogrel due to a better efficacy, albeit having more bleeding complication. These higher bleeding rates have provoked trials investigating de-escalation from ticagrelor or prasugrel to clopidogrel in the hope of reducing bleeding without increasing thrombotic event rates. In this review, we sought to present an overview of the major trials investigating several different options for de-escalation; unguided, platelet function testing- and genotype-guided. Based on these results, and on other established literature sources, such as guidelines and expert consensus papers, we provide an overview to help decide when and how to de-escalate antiplatelet therapy in ACS patients undergoing PCI.
Comparative Study of Clustering Approaches Applied to Spatial or Temporal Pattern Discovery
Authors: Grassi Kelly , Poisson-Caillault Émilie , Bigand André , Lefebvre Alain
Published: September 2020

In the framework of ecological or environmental assessments and management, detection, characterization and forecasting of the dynamics of environmental states are of paramount importance. These states should reflect general patterns of change, recurrent or occasional events, long-lasting or short or extreme events which contribute to explain the structure and the function of the ecosystem. To identify such states, many scientific consortiums promote the implementation of Integrated Observing Systems which generate increasing amount of complex multivariate/multisource/multiscale datasets. Extracting the most relevant ecological information from such complex datasets requires the implementation of Machine Learning-based processing tools. In this context, we proposed a divisive spectral clustering architecture—the Multi-level Spectral Clustering (M-SC) which is, in this paper, extended with a no-cut criteria. This method is developed to perform detection events for data with a complex shape and high local connexity. While the M-SC method was firstly developed and implemented for a given specific case study, we proposed here to compare our new M-SC method with several existing direct and hierarchical clustering approaches. The clustering performance is assessed from different datasets with hard shapes to segment. Spectral methods are most efficient discovering all spatial patterns. For the segmentation of time series, hierarchical methods better isolated event patterns. The new M-SC algorithm, which combines hierarchical and spectral approaches, give promise results in the segmentation of both spatial UCI databases and marine time series compared to other approaches. The ability of our M-SC method to deal with many kinds of datasets allows a large comparability of results if applies within a broad Integrated Observing Systems. Beyond scientific knowledge improvements, this comparability is crucial for decision-making about environmental management.
Firm Ownership and Enterprise Risk Management Implementation: Evidence from the Nordic Region
Authors: Sekerci Naciye , Pagach Don
Published: September 2020

The purpose of this paper is to investigate whether firm ownership characteristics can explain demand for Enterprise Risk Management (ERM) implementation. Specifically, we examine the relationship between the presence of large shareholders, multiple blockholders and a dual-class share structure, and ERM implementation. To our knowledge we provide the first evidence on the effect of multiple blockholders and dual-class share structures on the implementation of ERM. ERM best practices can be considered as governance tools, used to monitor managerial discretion in risk management, ultimately reducing the agency cost of risk management. Accordingly, we analyze the demand for ERM in certain governance (e.g., ownership) settings. We use quantitative methods in our study: survey and regressions (tobit and logit models). Ownership data is hand-collected while ERM data comes from a survey conducted in the Nordic region. We find that ERM is implemented less frequently in firms where there are multiple blockholders, and where large controlling owners hold dual-class shares. These findings indicate that there is less demand for ERM’s monitoring role in firms that are associated with high agency costs. Given the increasing use of dual-class share structures, we believe further examination of ownership characteristics and corporate risk management is warranted.
Exploring the Use of Sentinel-2 Data to Monitor Heterogeneous Effects of Contextual Drought and Heatwaves on Mediterranean Forests
Authors: Coluzzi Rosa , Fascetti Simonetta , Imbrenda Vito , Italiano Santain Settimio Pino , Ripullone Francesco , Lanfredi Maria
Published: September 2020

The use of satellite data to detect forest areas impacted by extreme events, such as droughts, heatwaves, or fires is largely documented, however, the use of these data to identify the heterogeneity of the forests’ response to determine fine scale spatially irregular damage is less explored. This paper evaluates the health status of forests in southern Italy affected by adverse climate conditions during the hot and dry summer of 2017, using Sentinel-2 images (10m) and in situ data. Our analysis shows that the post-event—NDVI (Normalized Difference Vegetation Index) decrease, observed in five experimental sites, well accounts for the heterogeneity of the local response to the climate event evaluated in situ through the Mannerucci and the Raunkiaer methods. As a result, Sentinel-2 data can be effectively integrated with biological information from field surveys to introduce continuity in the estimation of climate change impacts even in very heterogeneous areas whose details could not be captured by lower resolution observations. This integration appears to be a successful strategy in the study of the relationships between the climate and forests from a dynamical perspective.
Remotely Sensed Changes in Vegetation Cover Distribution and Groundwater along the Lower Gila River
Authors: Hartfield Kyle , Leeuwen Willem J.D. van , Gillan Jeffrey K.
Published: September 2020

Introduced as a soil erosion deterrent, salt cedar has become a menace along riverbeds in the desert southwest. Salt cedar replaces native species, permanently altering the structure, composition, function, and natural processes of the landscape. Remote sensing technologies have the potential to monitor the level of invasion and its impacts on ecosystem services. In this research, we developed a species map by segmenting and classifying various species along a stretch of the Lower Gila River. We calculated metrics from high-resolution multispectral imagery and light detection and ranging (LiDAR) data to identify salt cedar, mesquite, and creosote. Analysts derived training and validation information from drone-acquired orthophotos to achieve an overall accuracy of 94%. It is clear from the results that salt cedar completely dominates the study area with small numbers of mesquite and creosote present. We also show that vegetation has declined in the study area over the last 25 years. We discuss how water usage may be influencing the plant health and biodiversity in the region. An examination of ground well, stream gauge, and Gravity Recovery and Climate Experiment (GRACE) groundwater storage data indicates a decline in water levels near the study area over the last 25 years.
Evidence of Pepsin-Related Ocular Surface Damage and Dry Eye (PROD Syndrome) in Patients with Laryngopharyngeal Reflux
Authors: Plateroti Rocco , Sacchetti Marta , Magliulo Giuseppe , Plateroti Andrea Maria , Pace Annalisa , Moramarco Antonietta , Lambiase Alessandro , Bruscolini Alice
Published: September 2020

Background: patients with laryngopharyngeal reflux (LPR) showed detectable levels of tear pepsin that explain the nasolacrimal obstruction. The purpose of this study was to determine whether patients with LPR show ocular surface changes and to investigate the relationship between lacrimal pepsin concentration and ocular alterations. Methods: Fifty patients with positive endoscopic signs for LPR and an equal or higher score of 13 and 7 for Reflux Symptom Index and Reflux Finding Score were enrolled. Twenty healthy patients with no reflux disease and dry eye were included as the control group. After evaluation of ocular discomfort symptoms, the tear break-up time test, corneal staining, and tear sampling were performed. Tear pepsin levels were measured using Pep-testTM kit. Results: Patients with LPR showed ocular surface changes including epithelial damage (48%) and impairment of lacrimal function (72%). Tear pepsin levels were detectable in 32 out of 50 (64%) patients with LPR (mean ± SD: 55.4 ± 67.5 ng/mL) and in none of the control subjects. Most of the LPR patients complained of ocular discomfort symptoms, including itching (38%), redness (56%), or foreign body sensation (40%). Tear pepsin levels were significantly correlated with the severity of LPR disease and with ocular surface changes. Conclusions: A multidisciplinary approach, including ophthalmological evaluation, should be considered in order to improve the management of patients with LPR.
A Single Faecal Microbiota Transplantation Altered the Microbiota of Weaned Pigs
Authors: Nowland Tanya L. , Torok Valeria A. , Low Wai Y. , Plush Kate J. , Barton Mary D. , Kirkwood Roy N.
Published: September 2020

Weaning is a stressful time for piglets, often leading to weight loss and is associated with increased morbidity and mortality. A leading cause for these post-weaning problems is enteric dysbiosis and methods to improve piglet health at this crucial developmental stage are needed. This study aimed to determine whether an enteric dysbiosis caused by weaning could be corrected via a faecal microbiota transplantation (FMT) from healthy piglets from a previous wean. Two or four focal piglets per litter were assigned to one of two treatments; FMT two days post weaning (n = 21; FMT) or a control which received saline two days post weaning (n = 21; CON). FMT consisted of homogenised donor faeces administered orally at 3 mL/kg. Weaning occurred at 18 days of age and weights and faecal samples were collected on days 18, 20, 24 and 35. 16S rRNA amplicon analysis was used to assess the faecal microbiota of piglets. FMT increased Shannon’s diversity post weaning (p < 0.001) and reduced the scratch score observed at 24 days of age (p < 0.001). The bacterial populations significantly differed in composition at each taxonomic level. In FMT pigs, significant increases in potentially pathogenic Escherichia coli were observed. However, increases in beneficial bacteria Lactobacillus mucosae and genera Fibrobacteres and Bacteroidetes were also observed in FMT treated animals. To our knowledge, this is the first study to observe a significant effect on piglet faecal microbiota following a single FMT administered post weaning. Therefore, FMT post weaning can potentially alleviate enteric dysbiosis.
Microstructural, Tribology and Corrosion Properties of Optimized Fe3O4-SiC Reinforced Aluminum Matrix Hybrid Nano Filler Composite Fabricated through Powder Metallurgy Method
Authors: Ashrafi Negin , Azmah Hanim M. A. , Sarraf Masoud , Sulaiman S. , Hong Tang Sai
Published: September 2020

Hybrid reinforcement’s novel composite (Al-Fe3O4-SiC) via powder metallurgy method was successfully fabricated. In this study, the aim was to define the influence of SiC-Fe3O4 nanoparticles on microstructure, mechanical, tribology, and corrosion properties of the composite. Various researchers confirmed that aluminum matrix composite (AMC) is an excellent multifunctional lightweight material with remarkable properties. However, to improve the wear resistance in high-performance tribological application, hardening and developing corrosion resistance was needed; thus, an optimized hybrid reinforcement of particulates (SiC-Fe3O4) into an aluminum matrix was explored. Based on obtained results, the density and hardness were 2.69 g/cm3, 91 HV for Al-30Fe3O4-20SiC, after the sintering process. Coefficient of friction (COF) was decreased after adding Fe3O4 and SiC hybrid composite in tribology behaviors, and the lowest COF was 0.412 for Al-30Fe3O4-20SiC. The corrosion protection efficiency increased from 88.07%, 90.91%, and 99.83% for Al-30Fe3O4, Al-15Fe3O4-30SiC, and Al-30Fe3O4-20SiC samples, respectively. Hence, the addition of this reinforcement (Al-Fe3O4-SiC) to the composite shows a positive outcome toward corrosion resistance (lower corrosion rate), in order to increase the durability and life span of material during operation. The accomplished results indicated that, by increasing the weight percentage of SiC-Fe3O4, it had improved the mechanical properties, tribology, and corrosion resistance in aluminum matrix. After comparing all samples, we then selected Al-30Fe3O4-20SiC as an optimized composite.
Moving Towards a Finer Way of Light-Cured Resin-Based Restorative Dental Materials: Recent Advances in Photoinitiating Systems Based on Iodonium Salts
Authors: Topa Monika , Ortyl Joanna
Published: September 2020

The photoinduced polymerization of monomers is currently an essential tool in various industries. The photopolymerization process plays an increasingly important role in biomedical applications. It is especially used in the production of dental composites. It also exhibits unique properties, such as a short time of polymerization of composites (up to a few seconds), low energy consumption, and spatial resolution (polymerization only in irradiated areas). This paper describes a short overview of the history and classification of different typical monomers and photoinitiating systems such as bimolecular photoinitiator system containing camphorquinone and aromatic amine, 1-phenyl-1,2-propanedione, phosphine derivatives, germanium derivatives, hexaarylbiimidazole derivatives, silane-based derivatives and thioxanthone derivatives used in the production of dental composites with their limitations and disadvantages. Moreover, this article represents the challenges faced when using the latest inventions in the field of dental materials, with a particular focus on photoinitiating systems based on iodonium salts. The beneficial properties of dental composites cured using initiation systems based on iodonium salts have been demonstrated.
A Three-Player Game Model for Promoting the Diffusion of Green Technology in Manufacturing Enterprises from the Perspective of Supply and Demand
Authors: Wang Manman , Lian Shuai , Yin Shi , Dong Hengmin
Published: September 2020

Taking the rational use of environmental regulations to promote the diffusion of green technology innovation in China’s manufacturing enterprises as the starting point, this study analyzed the benefits to the government, innovation-supplying enterprises, and potential demand-oriented enterprises. In addition, a tripartite evolutionary model was constructed to examine the impact of command-and-control environmental regulation and market-driven environmental regulation on the diffusion of green technology innovation in manufacturing enterprises. Finally, the study compared and analyzed the heterogeneous effects of different types of environmental regulation tools on the diffusion of green technology innovation in manufacturing enterprises using local stability analysis and numerical simulation. The results are as follows: (i) When the government does not implement environmental regulation tools or the regulation intensity is relatively small, the diffusion depth of green technology innovation in manufacturing enterprises is zero. (ii) When government regulation reaches a certain level, the system of manufacturing enterprises, innovation-supplying enterprises, and potential demand-oriented enterprises will choose to actively promote the diffusion of green technology innovation following a long evolution process. (iii) Increasing the punishment intensity and subsidy rate of green technology innovation can stimulate the diffusion of green technology innovation in manufacturing enterprises. (iv) The comprehensive use of the two kinds of environmental regulation tools has a heterogeneous influence on the strategic choice of green technology innovation diffusion subjects of manufacturing enterprises, and its incentive effect on potential demand-oriented enterprises is relatively poor.
Nonlinear Profile Monitoring Using Spline Functions
Authors: Xin Hua , Hsieh Wan-Ju , Lio Yuhlong , Tsai Tzong-Ru
Published: September 2020

In this study, two new integrated control charts, named T2-MAE chart and MS-MAE chart, are introduced for monitoring the quality of a process when the mathematical form of nonlinear profile model for quality measure is complicated and unable to be specified. The T2-MAE chart is composed of two memoryless-type control charts and the MS-MAE chart is composed of one memory-type and one memoryless-type control charts. The normality assumption of error terms in the nonlinear profile model for both proposed control charts are extended to a generalized model. An intensive simulation study is conducted to evaluate the performance of the T2-MAE and MS-MAE charts. Simulation results show that the MS-MAE chart outperforms the T2-MAE chart with less false alarms during the Phase I monitoring. Moreover, the MS-MAE chart is sensitive to different shifts on the model parameters and profile shape during the Phase II monitoring. An example about the vertical density profile is used for illustration.
Diagnostic of Temporomandibular Disorders and Other Facial Pain Conditions—Narrative Review and Personal Experience
Authors: Małgorzata Pihut , Małgorzata Kulesa-Mrowiecka , Karolina Chmura , Gala Andrzej
Published: September 2020

Temporomandibular disorders are complex dysfunctions of masticatory muscles and temporomandibular joints. Their symptoms affect more than 40% of the population and their prevalence is rising. It is important to establish a unified protocol for this specialistic examination. This review describes the authors’ own longstanding experiences and the discrepancies in the current literature regarding this topic as well as a detailed procedure of diagnosing temporomandibular disorders including the leading but often underrated role of a medical interview. We presented optimal physical examination methods as well as specific situations in which additional diagnostic and imaging tools may be useful. The emphasis was put on the importance of differential diagnosis between temporomandibular disorders and other diseases presenting with similar symptoms.
Methotrexate and Adalimumab Decrease the Serum Levels of Cardiovascular Disease Biomarkers (VCAM-1 and E-Selectin) in Plaque Psoriasis
Authors: Zdanowska Natalia , Owczarczyk-Saczonek Agnieszka , Czerwińska Joanna , Nowakowski Jacek J. , Kozera-Żywczyk Anna , Owczarek Witold , Zdanowski Wojciech , Placek Waldemar
Published: September 2020

Background and objectives: The shared pathogenesis of psoriasis and atherosclerosis may be determined by assaying the levels of endothelial activation molecules. This study aimed at evaluating vascular cell adhesion molecule 1 (VCAM-1) and E-selectin serum concentrations, and atherosclerosis severity in patients with plaque psoriasis. It also aimed to determine the effects of methotrexate/adalimumab treatment for 12 weeks on the plasma levels of the aforementioned molecules. Materials and Methods: The study included 34 psoriasis patients (17 treated with methotrexate and 17 treated with adalimumab) and eight controls. The 10-year risk of a fatal cardiovascular disease, body mass index, Psoriasis Area and Severity Index, and body surface area were calculated for each subject. VCAM-1 and E-selectin levels were determined via an enzyme-linked immunosorbent assay at baseline and after 12 weeks. Results: Baseline E-selectin and VCAM-1 levels were higher in the adalimumab group than in the methotrexate and control groups. VCAM-1 levels decreased in the adalimumab (p = 0.02) and methotrexate groups (p = 0.008), while E-selectin levels decreased in the methotrexate group (p = 0.004). Conclusions: The results indicate a correlation between systemic psoriasis treatment and E-selectin and VCAM-1 plasma concentrations, which may be associated with the risk of cardiovascular disease development.
Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review
Authors: Romeo Domenico M. , Ricci Martina , Picilli Maria , Foti Benedetta , Cordaro Giorgia , Mercuri Eugenio
Published: September 2020

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.
Effect of Roller Quenching on Microstructure and Properties of 300 mm Thickness Ultra-Heavy Steel Plate
Authors: Han Jun , Fu Tianliang , Wang Zhaodong , Wang Guodong
Published: September 2020

In this paper, a 300 mm thickness ultra-heavy steel plate was selected as the research object. In addition, special roller quenching equipment and a new testing method were used to measure the quenching temperature curve at different positions of the steel plate. The relationships and corresponding interaction mechanisms between cooling rate, microstructure, and mechanical properties of an ultra-heavy steel plate during roller quenching were investigated. The results indicated that the cooling rate, strength, hardness, and impact energy decreased gradually along the thickness direction of the plate, while the cooling rate, average grain size, and mechanical properties were relatively uniform with little change along the length direction of the plate. The experimental results provide an effective way to further control the microstructure and properties of ultra-heavy steel plates during roller quenching.
Effect of Strain Rate on the Deformation Behaviour of A356-T7 Cast Aluminium Alloys at Elevated Temperatures
Authors: Natesan Elanghovan , Ahlström Johan , Manchili Swathi K. , Eriksson Stefan , Persson Christer
Published: September 2020

Internal combustion engine downsizing and powertrain electrification trends in recent years have led to higher thermal loads on the cylinder head materials with an increased number of engine start–stop thermal load cycles. This requires designing cylinder heads that are resilient against thermomechanical fatigue damage. To reduce the developmental costs, reliable numerical models for use in computer-aided design approaches are required. Thus, a comprehensive understanding of the material deformation behaviour under loads mimicking in-service conditions is desired to make better engineering decisions. This study examines the effect of strain rate on the cyclic deformation behaviour of the A356-T7 + 0.5% Cu aluminium alloy commonly used in modern internal combustion engine cylinder heads. Samples extracted from the valve bridge areas of the cylinder heads are tested in strain-controlled fatigue tests. Samples are tested at strain rates of 1% s−1 and 10% s−1 at room temperature, 150 and 200 °C. The material exhibits increased isotropic hardening and softening rates and an increased number of cycles to failure at 10% s−1. The strain rate has a dramatic influence on the mean stress development at room temperature. The role of silicon particles in the fracture mechanism is investigated using electron microscopy techniques.
Stabilizing Arsenic in Copper Heap Leaching Residues
Authors: Benavente Oscar , Hernández María Cecilia , Melo Evelyn , Quezada Víctor , Sepúlveda Yan , Zepeda Yuri
Published: September 2020

The need to sustainably produce raw materials encourages mining companies to develop and incorporate new economically and environmentally efficient processes. Therefore, there is a need to investigate the behavior and stabilization of hazardous elements present in effluents from metal recovery processes such as arsenic. This study evaluates the incorporation of an effluent solution from a copper smelter that is to be treated in a copper hydrometallurgical plant (heap leaching). The treatment is applied to recover compounds of interest such as copper, acid and water, in addition to confining impurities as stable residues in the leach residues. Here, we assess the capacity of the mineral to retain arsenic. To do this, a mixed solution of effluent and process solution was prepared, with a concentration of 1 g/L of arsenic. The solution was irrigated in leach columns loaded with a heap mineral with varying pH levels (0.8; 1.5 and 2) and solution potentials (510 and 540 mV). The concentrations of arsenic and iron in the solution and in the solid residues were measured to determine the capacity of the mineral to retain arsenic and how it was retained. The pH level plays an important role since, at a higher pH, the presence of arsenic and iron in the solution decreases, therefore increasing in the solid residue. Finally, a retention of 57% of arsenic is reached at pH 2. The characterization of the residues by scanning electron microscopy (SEM) confirms that arsenic is associated with Fe, S and O, forming ferric arsenates, while an X-Ray analysis identifies the arsenic compounds as crystalline scorodite.
Effect of MgO and K2O on High-Al Silicon–Manganese Alloy Slag Viscosity and Structure
Authors: Xing Xiangdong , Pang Zhuogang , Zheng Jianlu , Du Yueli , Ren Shan , Ju Jiantao
Published: September 2020

The viscosity, melting proprieties, and molten structure of the high-Al silicon–manganese slag of SiO2–CaO–25 mass% Al2O3–MgO–MnO–K2O system with a varying MgO and K2O content were studied. The results show that with the increase in MgO content from 4 to 10 mass%, the measured viscosity and flow activation energy decreases, but K2O has an effect on increasing those of slags. However, the melting temperature increases due to the formation of high-melting-point phase spinel. Meanwhile, Fourier transform infrared (FTIR) and X-ray photoelectron spectra (XPS) were conducted to understand the variation of slag structure. The O2− dissociates from MgO can interact with the O0 within Si–O or Al–O network structures, corresponding to the decrease in the trough depth of [SiO4] tetrahedral and [AlO4] tetrahedral. However, when K2O is added into the molten slag, the K+ can accelerate the formation of [AlO4] tetrahedra, resulting in the increase in O0 and O− and the polymerization of the structure.
Analysis and Prediction of the Thiourea Gold Leaching Process Using Grey Relational Analysis and Artificial Neural Networks
Authors: Xu Rui , Nan Xiaolong , Meng Feiyu , Li Qian , Chen Xuling , Yang Yongbin , Xu Bin , Jiang Tao
Published: September 2020

The thiourea (TU) leaching of gold from refractory ores can be considered an alternative to cyanidation. However, the high reagent consumption causes an increase in cost, which seriously limits its use. In order to effectively reduce the TU consumption, it is necessary to analyze the influencing parameters of gold recovery and TU consumption and apply them to the prediction of the TU leaching process. This paper investigated six potential influencing parameters and used grey relational analysis (GRA) to analyze the relational degree between each parameter and gold recovery and TU consumption. Then, the artificial neural network (ANN) model was established to simultaneously predict the gold recovery and TU consumption in the TU gold leaching process. The results of the GRA indicated that the leaching time, initial pH, temperature, TU dosage, stirring speed, and ferric iron concentration were all well related to the gold recovery and TU consumption. Therefore, the incorporation of these parameters can significantly improve the ANN model validation. The predictive results noted that the prediction accuracy of gold recovery varied from 94.46% to 98.06%, and the TU consumption varied from 95.15% to 99.20%. Thus, the predicted values corresponded closely to the experimental results, which suggested that the ANN model can accurately reflect the relationship between the operational conditions and the gold recovery and TU consumption. This prediction method can be used as an auxiliary decision-making tool in the TU gold leaching process, and it has broad engineering application prospects in engineering.