bluuebunny/crossref_metadata_2025 huggingface dataset:
Subnival Processes and Subnival Sedimentation Mechanisms, the Pamir-Alay Mts., Tajikistan
Authors: Kroh Paweł , Dolnicki Piotr , Łajczak Adam
Published: January 2021

Geomorphological research in the Fann Mountains of the Pamir-Alay has indicated that subnival processes are occurring. Contemporary subnival sediments indicate that complex relationships occur between the snow patches, subnival waters, and ground. Underneath a semi-permanent snow patch, snow melts slowly from the direction of the ground, resulting in a hollow that is filled with sediments produced by wash-down from the river terraces. The energy of subnival waters washes away and displaces sediments present underneath the snow patch, but also causes them to be redeposited. The sediment features imply a significant impact of the relief under the snow patch on the thickness of nival deposits and the nivation mechanism. The sediments also indicate that subnival waters may be under hydrostatic pressure, which has a considerable impact on both the snowmelt and sedimentation processes.
Hair Cortisol Concentration as a Biomarker of Sleep Quality and Related Disorders
Authors: El Mlili Nisrin , Ahabrach Hanan , Cauli Omar
Published: January 2021

Cortisol is the end product of the hypothalamic-pituitary-adrenal (HPA) axis, and its production is increased mainly in stressful situations or in chronic disorders accompanied by stress enhancement. Altered cortisol concentrations have been reported in a number of neuropsychiatric diseases and sleep disorders. Cortisol concentrations have been measured using several methods, and in several matrixes, such as blood, saliva, and urine. However, lately, hair cortisol, for several reasons, has emerged as a promising biomarker of long-term retrospective HPA activation. Several experimental approaches for cortisol measurement with the corresponding concentration reference ranges and a summary of findings from scientific literature on this field are presented. There is evidence of a close relationship between HPA functional alteration and the development of neuropsychiatric disorders. Sleep disorders are the most common manifestation in several neuropsychiatric conditions, and have also been associated to cortisol alterations in both adults and children. Many studies indicate that hair cortisol constitutes a valuable tool for further contributing to existing data on salivary, plasma, or urinary cortisol concentrations in patients with sleep disorders.
Discovery of Resident Behavior Patterns Using Machine Learning Techniques and IoT Paradigm
Authors: Reyes-Campos Josimar , Alor-Hernández Giner , Machorro-Cano Isaac , Olmedo-Aguirre José Oscar , Sánchez-Cervantes José Luis , Rodríguez-Mazahua Lisbeth
Published: January 2021

In recent years, technological paradigms such as Internet of Things (IoT) and machine learning have become very important due to the benefit that their application represents in various areas of knowledge. It is interesting to note that implementing these two technologies promotes more and better automatic control systems that adjust to each user’s particular preferences in the home automation area. This work presents Smart Home Control, an intelligent platform that offers fully customized automatic control schemes for a home’s domotic devices by obtaining residents’ behavior patterns and applying machine learning to the records of state changes of each device connected to the platform. The platform uses machine learning algorithm C4.5 and the Weka API to identify the behavior patterns necessary to build home devices’ configuration rules. Besides, an experimental case study that validates the platform’s effectiveness is presented, where behavior patterns of smart homes residents were identified according to the IoT devices usage history. The discovery of behavior patterns is essential to improve the automatic configuration schemes of personalization according to the residents’ history of device use.
Sleep Disorders in Autism Spectrum Disorder Pre-School Children: An Evaluation Using the Sleep Disturbance Scale for Children
Authors: Romeo Domenico M. , Brogna Claudia , Belli Arianna , Lucibello Simona , Cutrona Costanza , Apicella Massimo , Mercuri Eugenio , Mariotti Paolo
Published: January 2021

Background and Objectives: Sleep disorders are common in children with Autism Spectrum Disorder (ASD). The aims of this study were to describe the incidence and characteristics of sleep disorders using a questionnaire completed by the caregiver in a sample of preschool-aged children with ASD and to identify possible differences in a control group of peers. Materials and Methods: Sleep disorders were investigated with the Sleep Disturbance Scale for Children (SDSC) in a population of pre-school-aged (3–5 years) ASD children and in a control group. The Autism Diagnostic Observation Schedule—second ed. (ADOS-2) was further used to assess autism symptom severity. A total of 84 children (69 males; mean age 3.9 ± 0.8 years) with a diagnosis of ASD and 84 healthy controls (65 males; mean age of 3.7 ± 0.8 years) that were matched for age and sex were enrolled. Results: ASD children reported significantly higher (pathological) scores than the control group on the SDSC total scores and in some of the factor scores, such as Difficulty in Initiating and Maintaining Sleep (DIMS), disorders of excessive somnolence (DOES), and sleep hyperhidrosis. A total of 18% of ASD children had a pathological SDSC total T-score, and 46% had an abnormal score on at least one sleep factor; DIMS, parasomnias, and DOES showed the highest rates among the sleep factors. Younger children (3 years) reported higher scores in DIMS and sleep hyperhidrosis than older ones (4 and 5 years). No specific correlation was found between ADOS-2 and SDSC scores. Conclusions: Pre-school children with ASD showed a high incidence of sleep disorders with different distributions of specific sleep factors according to their age. We suggest a screening assessment of sleep disorders using the SDSC in these children with a more in-depth evaluation for those reporting pathological scores on the questionnaire.
Three-Dimensional Gait Analysis in Children Undergoing Gastrocsoleus Lengthening for Equinus Secondary to Cerebral Palsy
Authors: Ma Norine , Sclavos Nicholas , Passmore Elyse , Thomason Pam , Graham Kerr , Rutz Erich
Published: January 2021

Background and Objectives: Equinus is the most common deformity in children with cerebral palsy, and surgical lengthening of the gastrocsoleus muscle-tendon unit is the most commonly performed operation for children with cerebral palsy. Treatment outcomes of orthopaedic surgery can be measured objectively with three-dimensional gait analysis. This study examined the quality of evidence for gastrocsoleus lengthening surgery based on objective measures. Materials and Methods: A search was performed with Medline, Embase and PubMed from 1990 to 25 August 2020 using the keywords “cerebral palsy”, “equinus”, “surgery” and “gait analysis”. Only studies of gastrocsoleus lengthening surgery using three-dimensional gait analysis were included, yielding 34 studies. Results: Fourteen studies reported swing phase kinematics and all studies reported a significant improvement. Rates of recurrent equinus and calcaneus were reported in 21 studies and varied widely based on follow-up period and surgical technique. Conclusions: Poor study quality and marked variability in study samples and interventions made comparison difficult. Future studies should consider prospective design, controls or comparison groups and more detailed breakdowns of outcomes by cerebral palsy subtype, sagittal gait pattern, and equinus type in order to allow more rigorous treatment recommendations to be made.
Structural Interplays in the Flexible N-Terminus and Scaffolding Domain of Human Membrane Protein Caveolin 3
Authors: Park Hae-Jun , Jang Jinhwa , Ryu Kyung-Suk , Lee Jinhyuk , Lee Sung-Hee , Won Hyung-Sik , Kim Eun-Hee , Seo Min-Duk , Kim Ji-Hun
Published: January 2021

Caveolins are critical for the formation of caveolae, which are small invaginations of the plasma membrane involved in a variety of biological processes. Caveolin 3 (Cav3), one of three caveolin isoforms, is an integral membrane protein mainly expressed in muscle tissues. Although various human diseases associated with Cav3 have been reported, structural characterization of Cav3 in the membrane has not been investigated in enough depth to understand the structure–function relationship. Here, using solution NMR, we characterized membrane association, structural communications, and molecular dynamics of the monomeric Cav3 in detergent micelle environment, particularly focused on the whole N-terminal part that is composed of the flexible N-terminus and the scaffolding domain. The results revealed a complicated structural interplay of the individual segments composing the whole N-terminal part, including the pH-dependent helical region, signature motif-like region, signature motif, and scaffolding domain. Collectively, the present study provides novel structural insights into the whole N-terminal part of Cav3 that plays important biological roles in cellular processes and diseases. In particular, given that several disease-related mutations are located at the whole N-terminal part of Cav3, the sophisticated communications in the whole N-terminal segments are likely to have relevance to the molecular basis of Cav3-related disease.
Experimental Research on the Behaviour of Metal Active Gas Tailor Welded Blanks during Single Point Incremental Forming Process
Authors: Oleksik Valentin , Dobrota Dan , Racz Sever-Gabriel , Rusu Gabriela Petruta , Popp Mihai Octavian , Avrigean Eugen
Published: January 2021

The present paper aims to study the behaviour of Metal Active Gas (MAG) tailor welded blanks during the single point incremental forming process (SPIF) from an experimental point of view. The single point incremental forming process was chosen for manufacturing truncated cone and truncated pyramid shaped parts. The same material (S355) and the same thickness (0.9 mm) were selected for the joining of blank sheets because the main goal of the paper was to study the influence of the MAG welding process throughout the SPIF process. A Kuka robot, equipped with a force transducer and an optical measurement system were used for manufacturing and evaluating the parts by SPIF. The selected output data were major and minor strain, thickness reduction, forces and springback at the SPIF process. Another line test was performed to evaluate the formability in SPIF. The main conclusion of the paper is that during the SPIF process, fractures occur in one side welded blanks even at moderate wall angles, while in the case of double side welded blanks there is a decrease of formability but parts can still be produced at moderate angles (55 degrees) without any problems.
Cumulative Damage and Life Prediction Models for High-Cycle Fatigue of Metals: A Review
Authors: Hectors Kris , De Waele Wim
Published: January 2021

Fatigue design of engineering structures is typically based on lifetime calculation using a cumulative damage law. The linear damage rule by Miner is the universal standard for fatigue design even though numerous experimental studies have shown its deficiencies and possible non-conservative outcomes. In an effort to overcome these deficiencies, many nonlinear cumulative damage models and life prediction models have been developed since; however, none of them have found wide acceptance. This review article aims to provide a comprehensive overview of the state-of-the art in cumulative damage and lifetime prediction models for endurance based high-cycle fatigue design of metal structures.
Effect of Shielding Gas Volume Flow on the Consistency of Microstructure and Tensile Properties of 316L Manufactured by Selective Laser Melting
Authors: Ding Ruochen , Yao Jun , Du Baorui , Li Kailun , Li Tao , Zhao Lu , Guo Yumeng
Published: January 2021

In recent years, selective laser melting (SLM) has been widely used in aerospace, automobile, biomedicine and other fields. However, there still remain many challenges to obtain consistent parts at the different positions on the base plate, which could be harmful to the industrial mass-production. In SLM process, the process by-products that flow with the shielding gas may influence the microstructure and tensile properties of the parts placed on different positions of the base plate. In this study, the velocity field of the shielding gas with different shielding gas volume flows was simulated. The tensile properties of the samples fabricated with different shielding gas volume flow were experimentally studied. The results show that the shielding gas volume flow has a strong influence on the sample consistency, and proper increase in shielding gas volume flows can be beneficial to consistency and tensile strength.
Wearable Contact Lens Sensor for Non-Invasive Continuous Monitoring of Intraocular Pressure
Authors: Dou Zhiqiang , Tang Jun , Liu Zhiduo , Sun Qigong , Wang Yang , Li Yamin , Yuan Miao , Wu Huijuan , Wang Yijun , Pei Weihua , Chen Hongda
Published: January 2021

Intraocular pressure (IOP) is an essential indicator of the diagnosis and treatment of glaucoma. IOP has an apparent physiological rhythm, and it often reaches its peak value at night. To avoid missing the peak value at night and sample the entire rhythm cycle, the continuous monitoring of IOP is urgently needed. A wearable contact lens IOP sensor based on a platinum (Pt) strain gauge is fabricated by the micro-electro-mechanical (MEMS) process. The structure and parameters of the strain gauge are optimized to improve the sensitivity and temperature stability. Tests on an eyeball model indicate that the IOP sensor has a high sensitivity of 289.5 μV/mmHg and excellent dynamic cycling performance at different speeds of IOP variation. The temperature drift coefficient of the sensor is 33.4 μV/°C. The non-invasive IOP sensor proposed in this report exhibits high sensitivity and satisfactory stability, promising a potential in continuous IOP monitoring.
Lower Recovery of Nontuberculous Mycobacteria from Outdoor Hawai’i Environmental Water Biofilms Compared to Indoor Samples
Authors: Virdi Ravleen , Lowe Melissa E. , Norton Grant J. , Dawrs Stephanie N. , Hasan Nabeeh A. , Epperson L. Elaine , Glickman Cody M. , Chan Edward D. , Strong Michael , Crooks James L. , Honda Jennifer R.
Published: January 2021

Nontuberculous mycobacteria (NTM) are environmental organisms that can cause opportunistic pulmonary disease with species diversity showing significant regional variation. In the United States, Hawai’i shows the highest rate of NTM pulmonary disease. The need for improved understanding of NTM reservoirs led us to identify NTM from patient respiratory specimens and compare NTM diversity between outdoor and indoor locations in Hawai’i. A total of 545 water biofilm samples were collected from 357 unique locations across Kaua’i (n = 51), O’ahu (n = 202), Maui (n = 159), and Hawai’i Island (n = 133) and divided into outdoor (n = 179) or indoor (n = 366) categories. rpoB sequence analysis was used to determine NTM species and predictive modeling applied to develop NTM risk maps based on geographic characteristics between environments. M. chimaera was frequently identified from respiratory and environmental samples followed by M. chelonae and M. abscessus; yet significantly less NTM were consistently recovered from outdoor compared to indoor biofilms, as exemplified by showerhead biofilm samples. While the frequency of M. chimaera recovery was comparable between outdoor and indoor showerhead biofilms, phylogenetic analyses demonstrate similar rpoB gene sequences between all showerhead and respiratory M. chimaera isolates, supporting outdoor and indoor environments as possible sources for pulmonary M. chimaera infections.
Wide Distribution and Diversity of Malaria-Related Haemosporidian Parasites (Polychromophilus spp.) in Bats and Their Ectoparasites in Eastern Europe
Authors: Sándor Attila D. , Péter Áron , Corduneanu Alexandra , Barti Levente , Csősz István , Kalmár Zsuzsa , Hornok Sándor , Kontschán Jenő , Mihalca Andrei D.
Published: January 2021

Malaria is responsible for major diseases of humans, while associated haemosporidians are important factors in regulating wildlife populations. Polychromophilus, a haemosporidian parasite of bats, is phylogenetically close to human-pathogenic Plasmodium species, and their study may provide further clues for understanding the evolutionary relationships between vertebrates and malarial parasites. Our aim was to investigate the distribution of Polychromophilus spp. in Eastern Europe and test the importance of host ecology and roost site on haemosporidian parasite infection of bats. We sampled bats and their ectoparasites at eight locations in Romania and Bulgaria. DNA was extracted from blood samples and ectoparasites and tested individually for the presence of DNA of Polychromophilus spp. using a nested PCR targeting a 705 bp fragment of cytB. Two species of Polychromophilus were identified: Po. melanipherus in Miniopterus schreibersii and associated ectoparasites and Po. murinus in rhinolophid and vespertilionid bats (6 species) and their ticks and nycteribiid flies. Only cave-dwelling bat species (and their ectoparasites) showed infections, and we found a strong correlation between infections with Polychromophilus parasites and Nycteribiidae prevalence. We report the high genetic diversity of Polychromophilus spp. in Eastern Europe, suggesting that the simultaneous presence of varied host and vector assemblages enhances bat haemosporidian parasite diversity.
Adsorption of p-Arsanilic Acid on Iron (Hydr)oxides and Its Implications for Contamination in Soils
Authors: Yang Yifan , Tao Shiyong , Dong Zhichun , Xu Jing , Zhang Xiang , Pan Guoyan
Published: January 2021

Because of the diversification of industries in developing cities, the phenomenon of the simultaneous contamination of various kinds of pollutants is becoming common, and the environmental process of pollutants in multi-contaminated environmental mediums has attracted attention in recent years. In this study, p-arsanilic acid (ASA), a kind of organic arsenic feed additive that contains the arsenic group in a chemical structure, is used as a typical contaminant to investigate its adsorption on iron oxides and its implication for contaminated soils. The adsorption kinetics on all solids can be fitted to the pseudo-second-order kinetic model well. At the same mass dosage conditions, the adsorption amount per unit surface area on iron oxides follows the order α-FeOOH > γ-Fe2O3 > α-Fe2O3, which is significantly higher than that for actual soil, because of the lower content of iron oxides in actual soil. Lower pH conditions favor ASA adsorption, while higher pH conditions inhibit its adsorption as a result of the electrostatic repulsion and weakened hydrophobic interaction. The presence of phosphate also inhibits ASA adsorption because of the competitive effect. Correlations between the amount of ASA adsorption in actual soil and the Fe2O3 content, total phosphorus content, arsenic content, and organic matter content of actual soil are also investigated in this work, and a moderate positive correlation (R2 = 0.630), strong negative correlation (R2 = 0.734), insignificant positive correlation (R2 = 0.099), and no correlation (R2 = 0.006) are found, respectively. These findings would help evaluate the potential hazard of the usage of organic arsenic feed additives, as well as further the understanding of the geochemical processes of contaminants in complicated mediums.
Identification of Tyrosinase Inhibitors and Their Structure-Activity Relationships via Evolutionary Chemical Binding Similarity and Structure-Based Methods
Authors: Durai Prasannavenkatesh , Ko Young-Joon , Kim Jin-Chul , Pan Cheol-Ho , Park Keunwan
Published: January 2021

Tyrosinase is an enzyme that plays a crucial role in the melanogenesis of humans and the browning of food products. Thus, tyrosinase inhibitors that are useful to the cosmetic and food industries are required. In this study, we have used evolutionary chemical binding similarity (ECBS) to screen a virtual chemical database for human tyrosinase, which resulted in seven potential tyrosinase inhibitors confirmed through the tyrosinase inhibition assay. The tyrosinase inhibition percentage for three of the new actives was over 90% compared to 61.9% of kojic acid. From the structural analysis through pharmacophore modeling and molecular docking with the human tyrosinase model, the pi–pi interaction of tyrosinase inhibitors with conserved His367 and the polar interactions with Asn364, Glu345, and Glu203 were found to be essential for tyrosinase–ligand interactions. The pharmacophore features and the docking models showed high consistency, revealing the possible essential binding interactions of inhibitors to human tyrosinase. We have also presented the activity cliff analysis that successfully revealed the chemical features related to substantial activity changes found in the new tyrosinase inhibitors. The newly identified inhibitors and their structure–activity relationships presented here will help to identify or design new human tyrosinase inhibitors.
Low-Molecular-Weight Chitosan Attenuates Lipopolysaccharide-Induced Inflammation in IPEC-J2 Cells by Inhibiting the Nuclear Factor-κB Signalling Pathway
Authors: Zhang Jiao , Wan Jin , Chen Daiwen , Yu Bing , He Jun
Published: January 2021

Low-molecular-weight chitosan (LMWC), a product of chitosan deacetylation, possesses anti-inflammatory effects. In the present study, a porcine small intestinal epithelial cell line, IPEC-J2, was used to assess the protective effects of LMWC on lipopolysaccharide (LPS)-induced intestinal epithelial cell injury. IPEC-J2 cells were pretreated with or without LMWC (400 μg/mL) in the presence or absence of LPS (5 μg/mL) for 6 h. LMWC pretreatment increased (p < 0.05) the occludin abundance and decreased (p < 0.05) the tumour necrosis factor-α (TNF-α) production, apoptosis rate and cleaved cysteinyl aspartate-specific protease-3 (caspase-3) and -8 contents in LPS-treated IPEC-J2 cells. Moreover, LMWC pretreatment downregulated (p < 0.05) the expression levels of TNF receptor 1 (TNFR1) and TNFR-associated death domain and decreased (p < 0.05) the nuclear and cytoplasmic abundance of nuclear factor-κB (NF-κB) p65 in LPS-stimulated IPEC-J2 cells. These results suggest that LMWC exerts a mitigation effect on LPS-induced intestinal epithelial cell damage by suppressing TNFR1-mediated apoptosis and decreasing the production of proinflammatory cytokines via the inhibition of NF-κB signalling pathway.
Electrochemical Reduction of Carbon Dioxide on Graphene-Based Catalysts
Authors: Delgado Stefan , Arévalo María del Carmen , Pastor Elena , García Gonzalo
Published: January 2021

The current environmental situation requires taking actions regarding processes for energy production, thus promoting renewable energies, which must be complemented with the development of routes to reduce pollution, such as the capture and storage of CO2. Graphene materials have been chosen for their unique properties to be used either as electrocatalyst or as catalyst support (mainly for non-noble metals) that develop adequate efficiencies for this reaction. This review focuses on comparing experimental and theoretical results of the electrochemical reduction reaction of carbon dioxide (ECO2RR) described in the scientific literature to establish a correlation between them. This work aims to establish the state of the art on the electrochemical reduction of carbon dioxide on graphene-based catalysts.
Phytochemical Profiling, In Vitro and In Silico Anti-Microbial and Anti-Cancer Activity Evaluations and Staph GyraseB and h-TOP-IIβ Receptor-Docking Studies of Major Constituents of Zygophyllum coccineum L. Aqueous-Ethanolic Extract and Its Subsequent Fractions: An Approach to Validate Traditional Phytomedicinal Knowledge
Authors: Mohammed Hamdoon A. , Khan Riaz A. , Abdel-Hafez Atef A. , Abdel-Aziz Marwa , Ahmed Eman , Enany Shymaa , Mahgoub Sebaey , Al-Rugaie Osamah , Alsharidah Mansour , Aly Mohamed S. A. , Mehany Ahmed B. M. , Hegazy Mostafa M.
Published: January 2021

Zygophyllum coccineum, an edible halophytic plant, is part of the traditional medicine chest in the Mediterranean region for symptomatic relief of diabetes, hypertension, wound healing, burns, infections, and rheumatoid arthritis pain. The current study aimed to characterize Z. coccineum phytoconstituents, and the evaluations of the anti-microbial-biofilm, and anti-cancers bioactivities of the plant’s mother liquor, i.e., aqueous-ethanolic extract, and its subsequent fractions. The in silico receptors interaction feasibility of Z. coccineum major constituents with Staph GyraseB, and human topoisomerase-IIβ (h-TOP-IIβ) were conducted to confirm the plant’s anti-microbial and anti-cancer biological activities. Thirty-eight secondary metabolites of flavonoids, stilbene, phenolic acids, alkaloids, and coumarin classes identified by LC-ESI-TOF-MS spectrometric analysis, and tiliroside (kaempferol-3-O-(6′′′′-p-coumaroyl)-glucoside, 19.8%), zygophyloside-F (12.78%), zygophyloside-G (9.67%), and isorhamnetin-3-O-glucoside (4.75%) were identified as the major constituents. A superior biofilm obliteration activity established the minimum biofilm eradication concentration (MBEC) for the chloroform fraction at 3.9–15.63 µg/mL, as compared to the positive controls (15.63–31.25 µg/mL) against all the microbial strains that produced the biofilm under study, except the Aspergillus fumigatus. The aqueous-ethanolic extract showed cytotoxic effects with IC50 values at 3.47, 3.19, and 2.27 µg/mL against MCF-7, HCT-116, and HepG2 cell-lines, respectively, together with the inhibition of h-TOP-IIβ with IC50 value at 45.05 ng/mL in comparison to its standard referral inhibitor (staurosporine, IC50, 135.33 ng/mL). This conclusively established the anti-cancer activity of the aqueous-ethanolic extract that also validated by in silico receptor-binding predicted energy levels and receptor-site docking feasibility of the major constituents of the plant’s extract. The study helped to authenticate some of the traditional phytomedicinal properties of the anti-infectious nature of the plant.
Microstructure and Fracture Mechanism Investigation of Porous Silicon Nitride–Zirconia–Graphene Composite Using Multi-Scale and In-Situ Microscopy
Authors: Liao Zhongquan , Standke Yvonne , Gluch Jürgen , Balázsi Katalin , Pathak Onkar , Höhn Sören , Herrmann Mathias , Werner Stephan , Dusza Ján , Balázsi Csaba , Zschech Ehrenfried
Published: January 2021

Silicon nitride–zirconia–graphene composites with high graphene content (5 wt.% and 30 wt.%) were sintered by gas pressure sintering (GPS). The effect of the multilayer graphene (MLG) content on microstructure and fracture mechanism is investigated by multi-scale and in-situ microscopy. Multi-scale microscopy confirms that the phases disperse evenly in the microstructure without obvious agglomeration. The MLG flakes well dispersed between ceramic matrix grains slow down the phase transformation from α to β-Si3N4, subsequent needle-like growth of β-Si3N4 rods and the densification due to the reduction in sintering additives particularly in the case with 30 wt.% MLG. The size distribution of Si3N4 phase shifts towards a larger size range with the increase in graphene content from 5 to 30 wt.%, while a higher graphene content (30 wt.%) hinders the growth of the ZrO2 phase. The composite with 30 wt.% MLG has a porosity of 47%, the one with 5 wt.% exhibits a porosity of approximately 30%. Both Si3N4/MLG composites show potential resistance to contact or indentation damage. Crack initiation and propagation, densification of the porous microstructure, and shift of ceramic phases are observed using in-situ transmission electron microscopy. The crack propagates through the ceramic/MLG interface and through both the ceramic and the non-ceramic components in the composite with low graphene content. However, the crack prefers to bypass ceramic phases in the composite with 30 wt.% MLG.
Producing Magnetic Nanocomposites from Paper Sludge for the Adsorptive Removal of Pharmaceuticals from Water—A Fractional Factorial Design
Authors: Rocha Luciana S. , Sousa Érika M. L. , Gil María V. , Oliveira João A. B. P. , Otero Marta , Esteves Valdemar I. , Calisto Vânia
Published: January 2021

In view of a simple after-use separation, the potentiality of producing magnetic activated carbon (MAC) by intercalation of ferromagnetic metal oxide nanoparticles in the framework of a powder activated carbon (PAC) produced from primary paper sludge was explored in this work. The synthesis conditions to produce cost effective and efficient MACs for the adsorptive removal of pharmaceuticals (amoxicillin, carbamazepine, and diclofenac) from aqueous media were evaluated. For this purpose, a fractional factorial design (FFD) was applied to assess the effect of the most significant variables (Fe3+ to Fe2+ salts ratio, PAC to iron salts ratio, temperature, and pH), on the following responses concerning the resulting MACs: Specific surface area (SBET), saturation magnetization (Ms), and adsorption percentage of amoxicillin, carbamazepine, and diclofenac. The statistical analysis revealed that the PAC to iron salts mass ratio was the main factor affecting the considered responses. A quadratic linear regression model A = f(SBET, Ms) was adjusted to the FFD data, allowing to differentiate four of the eighteen MACs produced. These MACs were distinguished by being easily recovered from aqueous phase using a permanent magnet (Ms of 22–27 emu g−1), and their high SBET (741–795 m2 g−1) were responsible for individual adsorption percentages ranging between 61% and 84% using small MAC doses (35 mg L−1).
Control of Raw Pork Liver Sausage Production Can Reduce the Prevalence of HEV Infection
Authors: Ripellino Paolo , Pianezzi Enea , Martinetti Gladys , Zehnder Cinzia , Mathis Barbara , Giannini Petra , Forrer Nicola , Merlani Giorgio , Dalton Harry R. , Petrini Orlando , Bihl Florian , Fontana Stefano , Gobbi Claudio
Published: January 2021

After an acute hepatitis E (HEV) outbreak in Southern Switzerland, in January 2017 the local public health authorities started an active program of food chain control and public education. In this retrospective study, we analysed all laboratory-confirmed acute cases of HEV infection diagnosed between 2014 and 2020. In the period before the public health intervention, the number of cases increased steadily from 2014 (4 of 40 tests, 10%) reaching a peak in the last quarter of 2016 (42 of 285 tests, 14.7 %). Afterwards, the number of positive cases decreased steadily, reaching its lowest value (0.3%) in the second quarter of 2019. There was a statistically significant difference between the frequency of positive cases and period of testing, i.e., before and after the introduction of the public health interventions. Our study shows that active public health measures to control sausages containing raw pork liver can reduce the prevalence of HEV infection.
Therapeutic Sequencing in ALK+ NSCLC
Authors: Elsayed Mei , Christopoulos Petros
Published: January 2021

Anaplastic lymphoma kinase-rearranged non-small-cell lung cancer (ALK+ NSCLC) is a model disease for the use of targeted pharmaceuticals in thoracic oncology. Due to higher systemic and intracranial efficacy, the second-generation ALK tyrosine kinase inhibitors (TKI) alectinib and brigatinib have irrevocably displaced crizotinib as standard first-line treatment, based on the results of the ALEX and ALTA-1L trials. Besides, lorlatinib and brigatinib are the preferred second-line therapies for progression under second-generation TKI and crizotinib, respectively, based on the results of several phase II studies. Tissue or liquid rebiopsies at the time of disease progression, even though not mandated by the approval status of any ALK inhibitor, are gaining importance for individualization and optimization of patient management. Of particular interest are cases with off-target resistance, for example MET, HER2 or KRAS alterations, which require special therapeutic maneuvers, e.g., inclusion in early clinical trials or off-label administration of respectively targeted drugs. On the other hand, up to approximately half of the patients failing TKI, develop anatomically restricted progression, which can be initially tackled with local ablative measures without switch of systemic therapy. Among the overall biologically favorable ALK+ tumors, with a mean tumor mutational burden uniquely below 3 mutations per Mb and the longest survival among NSCLC currently, presence of the EML4-ALK fusion variant 3 and/or TP53 mutations identify high-risk cases with earlier treatment failure and a need for more aggressive surveillance and treatment strategies. The potential clinical utility of longitudinal ctDNA assays for earlier detection of disease progression and improved guidance of therapy in these patients is a currently a matter of intense investigation. Major pharmaceutical challenges for the field are the development of more potent, fourth-generation TKI and effective immuno-oncological interventions, especially ALK-directed cell therapies, which will be essential for further improving survival and achieving cure of ALK+ tumors.
Bacterial Cell Wall Analogue Peptides Control the Oligomeric States and Activity of the Glycopeptide Antibiotic Eremomycin: Solution NMR and Antimicrobial Studies
Authors: Izsépi László , Erdei Réka , Tevyashova Anna N. , Grammatikova Natalia E. , Shchekotikhin Andrey E. , Herczegh Pál , Batta Gyula
Published: January 2021

For some time, glycopeptide antibiotics have been considered the last line of defense against Methicillin-resistant Staphylococcus aureus (MRSA). However, vancomycin resistance of Gram-positive bacteria is an increasingly emerging worldwide health problem. The mode of action of glycopeptide antibiotics is essentially the binding of peptidoglycan cell-wall fragments terminating in the d-Ala-d-Ala sequence to the carboxylate anion binding pocket of the antibiotic. Dimerization of these antibiotics in aqueous solution was shown to persist and even to enhance the antibacterial effect in a co-operative manner. Some works based on solid state (ss) Nuclear Magnetic Resonance (NMR) studies questioned the presence of dimers under the conditions of ssNMR while in a few cases, higher-order oligomers associated with contiguous back-to-back and face-to-face dimers were observed in the crystal phase. However, it is not proved if such oligomers persist in aqueous solutions. With the aid of 15N-labelled eremomycin using 15N relaxation and diffusion NMR methods, we observed tetramers and octamers when the N-Ac-d-Ala-d-Ala dipeptide was added. To the contrary, the N-Ac-d-Ala or (N-Ac)2-l-Lys-d-Ala-d-Ala tripeptide did not induce higher-order oligomers. These observations are interesting examples of tailored supramolecular self-organization. New antimicrobial tests have also been carried out with these self-assemblies against MRSA and VRE (resistant) strains.
Paenibacillus alvei K165 and Fusarium oxysporum F2: Potential Biocontrol Agents against Phaeomoniella chlamydospora in Grapevines
Authors: Gkikas Fedon-Ioannis , Tako Alexandros , Gkizi Danai , Lagogianni Christina , Markakis Emmanouil A. , Tjamos Sotirios E.
Published: January 2021

In the last two decades grapevine trunk diseases (GTDs) have emerged as the most significant threat for grapevine sustainability worldwide. The tracheomycotic fungus Phaeomoniella chlamydospora (Pch) is the predominant GTD-associated species and cannot be controlled with available chemicals. In the present study, we evaluated the effectiveness of two microbial strains (Paenibacillus alvei K165 and Fusarium oxysporum F2) against Pch in grapevine. In vitro bioassays, performed in a growth culture medium simulating the xylem environment, indicated that F2 decreased Pch growth and sporulation, whereas K165 did not have any effect on Pch growth. In planta experiments revealed that root-drench and stem-puncture application of K165 and F2 reduced the endophytic relative DNA amount of Pch by 90% and 82%, respectively, compared to controls. However, wood discoloration, the typical symptom of Pch infection, was not reduced in the F2 treated grapevines. Nevertheless, the F2 treated grapevines harbored higher lignin levels compared to mocks, as it was also done by K165. Therefore, F2 and K165 have the potential to be used as biocontrol agents against Pch in grapevines.
Polymer Nanoparticles and Nanomotors Modified by DNA/RNA Aptamers and Antibodies in Targeted Therapy of Cancer
Authors: Subjakova Veronika , Oravczova Veronika , Hianik Tibor
Published: January 2021

Polymer nanoparticles and nano/micromotors are novel nanostructures that are of increased interest especially in the diagnosis and therapy of cancer. These structures are modified by antibodies or nucleic acid aptamers and can recognize the cancer markers at the membrane of the cancer cells or in the intracellular side. They can serve as a cargo for targeted transport of drugs or nucleic acids in chemo- immuno- or gene therapy. The various mechanisms, such as enzyme, ultrasound, magnetic, electrical, or light, served as a driving force for nano/micromotors, allowing their transport into the cells. This review is focused on the recent achievements in the development of polymer nanoparticles and nano/micromotors modified by antibodies and nucleic acid aptamers. The methods of preparation of polymer nanoparticles, their structure and properties are provided together with those for synthesis and the application of nano/micromotors. The various mechanisms of the driving of nano/micromotors such as chemical, light, ultrasound, electric and magnetic fields are explained. The targeting drug delivery is based on the modification of nanostructures by receptors such as nucleic acid aptamers and antibodies. Special focus is therefore on the method of selection aptamers for recognition cancer markers as well as on the comparison of the properties of nucleic acid aptamers and antibodies. The methods of immobilization of aptamers at the nanoparticles and nano/micromotors are provided. Examples of applications of polymer nanoparticles and nano/micromotors in targeted delivery and in controlled drug release are presented. The future perspectives of biomimetic nanostructures in personalized nanomedicine are also discussed.
Carboxymethyl Bacterial Cellulose from Nata de Coco: Effects of NaOH
Authors: Rachtanapun Pornchai , Jantrawut Pensak , Klunklin Warinporn , Jantanasakulwong Kittisak , Phimolsiripol Yuthana , Leksawasdi Noppol , Seesuriyachan Phisit , Chaiyaso Thanongsak , Insomphun Chayatip , Phongthai Suphat , Sommano Sarana Rose , Punyodom Winita , Reungsang Alissara , Ngo Thi Minh Phuong
Published: January 2021

Bacterial cellulose from nata de coco was prepared from the fermentation of coconut juice with Acetobacter xylinum for 10 days at room temperature under sterile conditions. Carboxymethyl cellulose (CMC) was transformed from the bacterial cellulose from the nata de coco by carboxymethylation using different concentrations of sodium hydroxide (NaOH) and monochloroacetic acid (MCA) in an isopropyl (IPA) medium. The effects of various NaOH concentrations on the degree of substitution (DS), chemical structure, viscosity, color, crystallinity, morphology and the thermal properties of carboxymethyl bacterial cellulose powder from nata de coco (CMCn) were evaluated. In the carboxymethylation process, the optimal condition resulted from NaOH amount of 30 g/100 mL, as this provided the highest DS value (0.92). The crystallinity of CMCn declined after synthesis but seemed to be the same in each condition. The mechanical properties (tensile strength and percentage of elongation at break), water vapor permeability (WVP) and morphology of CMCn films obtained from CMCn synthesis using different NaOH concentrations were investigated. The tensile strength of CMCn film synthesized with a NaOH concentration of 30 g/100 mL increased, however it declined when the amount of NaOH concentration was too high. This result correlated with the DS value. The highest percent elongation at break was obtained from CMCn films synthesized with 50 g/100 mL NaOH, whereas the elongation at break decreased when NaOH concentration increased to 60 g/100 mL.
Using Quantitative Passive Thermography and Modified Paris-Law for Probabilistic Calculation of the Fatigue Damage Development in a CFRP-Aluminum Hybrid Joint
Authors: Summa Jannik , Herrmann Hans-Georg
Published: January 2021

Although metal to Carbon-fiber-reinforced-polymer (CFRP) hybrid-joints possess a high lightweight construction potential, their extensive application has to deal with interfacial stress concentrations promoting fatigue damage. Furthermore, the underlying damage processes and their influencing factors are still not completely understood. Besides interfacial property-gradients, generic shapes counteract a precise determination of local stresses or strains, respectively. Hence, new methods are required that combine non-destructive testing and fracture mechanics to account for the fatigue damage. In this work, data of mechanical fatigue testing of an aluminum-CFRP hybrid-structure is presented by means of the dynamic stiffness and the mechanical hysteresis. Additionally, in situ passive thermography allows for capturing the heat development due to delamination growth. Correlating the obtained data implies that faster delamination growth coincides with higher amplitude values of lock-in thermography and higher mechanical hysteresis. Supported by this observation, a model is formulated to calculate the local dissipation per loading cycle. Further integration into a Paris-law like formulation results in a calculation model to account for the mode-I fatigue delamination growth. Additional validation of the model parameters shows good agreement with the experimental data.
Acknowledgment to Reviewers of Polymers in 2020
Authors:   Polymers Editorial Office
Published: January 2021

Peer review is the driving force of journal development, and reviewers are gatekeepers who ensure that Polymers maintains its standards for the high quality of its published papers [...]
Alginate/κ-Carrageenan-Based Edible Films Incorporated with Clove Essential Oil: Physico-Chemical Characterization and Antioxidant-Antimicrobial Activity
Authors: Prasetyaningrum Aji , Utomo Dani P. , Raemas Al Farrel A. , Kusworo Tutuk D. , Jos Bakti , Djaeni Mohammad
Published: January 2021

This study aimed to enhance the properties of CaCl2 crosslinked sodium alginate/k-carrageenan (SA/KC) incorporated with clove essential oil (CEO). An evaluation of the modification effects on physicochemical, morphological, antioxidant, and antibacterial properties was performed. The properties were observed at various SA/KC ratios (10/0 to 1.5/1), CEO (1.5% to 3%), and CaCl2 (0% to 2%). The surface morphology was improved by addition of KC and CaCl2. The Fourier transform infrared (FTIR) result showed insignificant alteration of film chemical structure. The X-ray diffraction (XRD) result confirmed the increased crystallinity index of the film by CaCl2 addition. On physicochemical properties, a higher proportion of SA/KC showed the declined tensile strength, meanwhile both elongation at break and water solubility were increased. The incorporated CEO film reduced both tensile strength and water solubility; however, the elongation at break was significantly increased. The presence of Ca2+ ions remarkably increased the tensile strength despite decreased water solubility. Overall, the addition of KC and CaCl2 helped in repairing the mechanical properties and flexibility. CEO incorporation showed the effectiveness of profiling the antioxidant and antimicrobial activity indicated by high 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity up to 90.32% and inhibition zone of E. coli growth up to 113.14 mm2.
Evaluation of New Antimicrobial Materials Incorporating Ethyl Lauroyl Arginate or Silver into Different Matrices, and Their Safety in Use as Potential Packaging
Authors: Manso Sofía , Wrona Magdalena , Salafranca Jesús , Nerín Cristina , Alfonso María José , Caballero Miguel Ángel
Published: January 2021

A big challenge for today’s industry is antimicrobial preservation and the safety of food. An effective solution to this problem can be a modern invention such as antimicrobial packaging. In the presented research the antimicrobial activity of two new active films incorporating silver, as IONPURE IPL, and ethyl lauroyl arginate (LAE) were evaluated, by employing a low-density polyethylene (LDPE) matrix and a biofilm material, respectively. Additionally, LAE was also incorporated into polystyrene (PS) pads by two different methods: by spraying and by immersion of the PS pads into an aqueous LAE solution. LDPE films containing silver did not show any antimicrobial activity against Escherichia coli and Aspergillus flavus, whereas the biofilm containing LAE reduced the growth of Salmonella enterica but did not inhibit Aspergillus flavus. The active PS pads, both sprayed and immersed in LAE solution, also showed antimicrobial activity, causing a reduction of 99.99% of Pseudomonas putida growth. Thermal treatment at 180 °C for 6 and 15 min did not modify the antimicrobial activity of LAE against Salmonella enterica. Moreover, inductively coupled plasma-mass spectrometry (ICP-MS) analysis was performed to check the migration of silver from developed material intended for food packaging applications into food simulant.
Bending Analysis of Polymer-Based Flexible Antennas for Wearable, General IoT Applications: A Review
Authors: Ali Khan Muhammad Usman , Raad Raad , Tubbal Faisel , Theoharis Panagiotis Ioannis , Liu Sining , Foroughi Javad
Published: January 2021

Flexible substrates have become essential in order to provide increased flexibility in wearable sensors, including polymers, plastic, paper, textiles and fabrics. This study is to comprehensively summarize the bending capabilities of flexible polymer substrate for general Internet of Things (IoTs) applications. The basic premise is to investigate the flexibility and bending ability of polymer materials as well as their tendency to withstand deformation. We start by providing a chronological order of flexible materials which have been used during the last few decades. In the future, the IoT is expected to support a diverse set of technologies to enable new applications through wireless connectivity. For wearable IoTs, flexibility and bending capabilities of materials are required. This paper provides an overview of some abundantly used polymer substrates and compares their physical, electrical and mechanical properties. It also studies the bending effects on the radiation performance of antenna designs that use polymer substrates. Moreover, we explore a selection of flexible materials for flexible antennas in IoT applications, namely Polyimides (PI), Polyethylene Terephthalate (PET), Polydimethylsiloxane (PDMS), Polytetrafluoroethylene (PTFE), Rogers RT/Duroid and Liquid Crystal Polymer (LCP). The study includes a complete analysis of bending and folding effects on the radiation characteristics such as S-parameters, resonant frequency deviation and the impedance mismatch with feedline of the flexible polymer substrate microstrip antennas. These flexible polymer substrates are useful for future wearable devices and general IoT applications.