bluuebunny/crossref_metadata_2025 huggingface dataset:
Status and Challenges of Plant-Anticancer Compounds in Cancer Treatment
Authors: Garcia-Oliveira Paula , Otero Paz , Pereira Antia Gonzalez , Chamorro Franklin , Carpena Maria , Echave Javier , Fraga-Corral Maria , Simal-Gandara Jesus , Prieto Miguel Angel
Published: February 2021

Nowadays, cancer is one of the deadliest diseases in the world, which has been estimated to cause 9.9 million deaths in 2020. Conventional treatments for cancer commonly involve mono-chemotherapy or a combination of radiotherapy and mono-chemotherapy. However, the negative side effects of these approaches have been extensively reported and have prompted the search of new therapeutic drugs. In this context, scientific community started to look for innovative sources of anticancer compounds in natural sources, including traditional plants. Currently, numerous studies have evaluated the anticancer properties of natural compounds derived from plants, both in vitro and in vivo. In pre-clinical stages, some promising compounds could be mentioned, such as the sulforaphane or different phenolic compounds. On the other hand, some phytochemicals obtained positive results in clinical stages and were further approved for cancer treatment, such as vinca alkaloids or the paclitaxel. Nevertheless, these compounds are not exempt of limitations, such as low solubility, restricted effect on their own, negative side-effects, etc. This review aims to compile the information about the current phytochemicals used for cancer treatment and also promising candidates, main action mechanisms and also reported limitations. In this sense, some strategies to face the limitations have been considered, such as nano-based formulations to improve solubility or chemical modification to reduce toxicity. In conclusion, although more research is still necessary to develop more efficient and safe phytochemical drugs, more of these compounds might be used in future cancer therapies.
Contributions of Glycolipid Biosurfactants and Glycolipid-Modified Materials to Antimicrobial Strategy: A Review
Authors: Shu Qin , Lou Hanghang , Wei Tianyu , Liu Xiayu , Chen Qihe
Published: February 2021

Glycolipid biosurfactants are natural amphiphiles and have gained particular interest recently in their biodegradability, diversity, and bioactivity. Microbial infection has caused severe morbidity and mortality and threatened public health security worldwide. Glycolipids have played an important role in combating many diseases as therapeutic agents depending on the self-assembly property, the anticancer and anti-inflammatory properties, and the antimicrobial properties, including antibacterial, antifungal, and antiviral effects. Besides, their role has been highlighted as scavengers in impeding the biofilm formation and rupturing mature biofilm, indicating their utility as suitable anti-adhesive coating agents for medical insertional materials leading to a reduction in vast hospital infections. Notably, glycolipids have been widely applied to the synthesis of novel antimicrobial materials due to their excellent amphipathicity, such as nanoparticles and liposomes. Accordingly, this review will provide various antimicrobial applications of glycolipids as functional ingredients in medical therapy.
Dexamethasone PLGA Microspheres for Sub-Tenon Administration: Influence of Sterilization and Tolerance Studies
Authors: Barbosa-Alfaro Deyanira , Andrés-Guerrero Vanessa , Fernandez-Bueno Ivan , García-Gutiérrez María Teresa , Gil-Alegre Esther , Molina-Martínez Irene Teresa , Pastor-Jimeno José Carlos , Herrero-Vanrell Rocío , Bravo-Osuna Irene
Published: February 2021

Many diseases affecting the posterior segment of the eye require repeated intravitreal injections with corticosteroids in chronic treatments. The periocular administration is a less invasive route attracting considerable attention for long-term therapies. In the present work, dexamethasone-loaded poly(lactic-co-glycolic) acid (PLGA) microspheres (Dx-MS) were prepared using the oil-in-water (O/W) emulsion solvent evaporation technique. MS were characterized in terms of mean particle size and particle size distribution, external morphology, polymer integrity, drug content, and in vitro release profiles. MS were sterilized by gamma irradiation (25 kGy), and dexamethasone release profiles from sterilized and non-sterilized microspheres were compared by means of the similarity factor (f2). The mechanism of drug release before and after irradiation exposure of Dx-MS was identified using appropriate mathematical models. Dexamethasone release was sustained in vitro for 9 weeks. The evaluation of the in vivo tolerance was carried out in rabbit eyes, which received a sub-Tenon injection of 5 mg of sterilized Dx-MS (20–53 µm size containing 165.6 ± 3.6 µg Dx/mg MS) equivalent to 828 µg of Dx. No detectable increase in intraocular pressure was reported, and clinical and histological analysis of the ocular tissues showed no adverse events up to 6 weeks after the administration. According to the data presented in this work, the sub-Tenon administration of Dx-MS could be a promising alternative to successive intravitreal injections for the treatment of chronic diseases of the back of the eye.
Disruption of pH Dynamics Suppresses Proliferation and Potentiates Doxorubicin Cytotoxicity in Breast Cancer Cells
Authors: Tavares-Valente Diana , Sousa Bárbara , Schmitt Fernando , Baltazar Fátima , Queirós Odília
Published: February 2021

The reverse pH gradient is a major feature associated with cancer cell reprogrammed metabolism. This phenotype is supported by increased activity of pH regulators like ATPases, carbonic anhydrases (CAs), monocarboxylate transporters (MCTs) and sodium–proton exchangers (NHEs) that induce an acidic tumor microenvironment, responsible for the cancer acid-resistant phenotype. In this work, we analyzed the expression of these pH regulators and explored their inhibition in breast cancer cells as a strategy to enhance the sensitivity to chemotherapy. Expression of the different pH regulators was evaluated by immunofluorescence and Western blot in two breast cancer cell lines (MDA-MB-231 and MCF-7) and by immunohistochemistry in human breast cancer tissues. Cell viability, migration and invasion were evaluated upon exposure to the pH regulator inhibitors (PRIs) concanamycin-A, cariporide, acetazolamide and cyano-4-hydroxycinnamate. Additionally, PRIs were combined with doxorubicin to analyze the effect of cell pH dynamic disruption on doxorubicin sensitivity. Both cancer cell lines expressed all pH regulators, except for MCT1 and CAXII, only expressed in MCF-7 cells. There was higher plasma membrane expression of the pH regulators in human breast cancer tissues than in normal breast epithelium. Additionally, pH regulator expression was significantly associated with different molecular subtypes of breast cancer. pH regulator inhibition decreased cancer cell aggressiveness, with a higher effect in MDA-MB-231. A synergistic inhibitory effect was observed when PRIs were combined with doxorubicin in the breast cancer cell line viability. Our results support proton dynamic disruption as a breast cancer antitumor strategy and the use of PRIs to boost the activity of conventional therapy.
A Descriptive Study Examining Trends in Pharmacist-Authored Original Research Publications in the Journal of the American Medical Association Network from 2000 to 2019
Authors: Strong Delaney M. , Fuji Kevin T.
Published: February 2021

Pharmacists are expected to participate in the conduction of research to advance the profession and health care broadly. Additional opportunities for pharmacist research engagement have emerged with the increased integration of clinically trained pharmacists into interprofessional care teams. Research conducted over the past four decades has demonstrated an increasing trend of pharmacist-authored publications in medical journals. The purpose of this study was to build upon this work and investigate trends in pharmacist-authored original research publications within the JAMA Network over the past 20 years. A descriptive study design was used to retrospectively evaluate trends in the numbers of pharmacist-authored publications and authorship within those publications in nine JAMA Network journals. Data were aggregated into ten-year time periods (2000–2009 and 2010–2019) and compared using chi-square and Fisher’s exact tests. Overall, pharmacist-authored publications significantly increased over the ten-year period (2.0% to 3.0%, p < 0.001), including in five specific journals: JAMA, JAMA Dermatology, JAMA Neurology, JAMA Ophthalmology, and JAMA Surgery. There was no change in first—and senior-authored publications. While the overall pharmacist publication trend was positive, room for significant growth remains. A deeper understanding of the barriers and facilitators to pharmacist engagement in research is needed, along with strategies to enhance pharmacist research training.
From Paper to E-Prescribing of Multidose Drug Dispensing: A Qualitative Study of Workflow in a Community Care Setting
Authors: Josendal Anette Vik , Bergmo Trine Strand
Published: February 2021

E-prescribing is now widespread and, in some countries, has completely replaced paper prescriptions. In Norway, almost all prescribing is electronic, except for multidose drug dispensing (MDD), which is still sent to the pharmacy by fax or ordinary mail. MDD is an adherence aid used by one-third of all patients receiving home care services. In this paper, we present results from a qualitative study evaluating the introduction of e-prescribing for MDD in a community health care setting. The focus is on the work and workflow for the pharmacists and nurses involved in the medication-handling process. We used the pragmatic process evaluation framework and the systematic text condensation method to analyse the data. We conducted 12 interviews with 34 nurses and pharmacists. This study shows that the e-prescribing of MDD led to greater integration between systems, both within the existing MDD system and across care levels, potentially improving patient safety. However, the structured prescriptions increased the need for clarifications, resulting in an increased overall workload. A greater understanding of the roles and responsibilities of the different professionals in the medication management chain and their needs would improve the workflow of the nurses and pharmacists involved.
Mie Resonance Engineering in Two Disks
Authors: Bulgakov Evgeny , Pichugin Konstantin , Sadreev Almas
Published: February 2021

Recently the recipes to achieve the high-Q subwavelength resonances in an isolated dielectric disk have been reported based on avoided crossing (anticrossing) of the TE resonances under variation of the aspect ratio of the disk. In a silicon disk that recipe gives an enhancement of the Q factor by one order of magnitude. In the present paper we present the approach based on engineering of the spherical Mie resonances with high orbital index in two coaxial disks by two-fold avoided crossing of the resonant modes of the disks. At the first step we select the resonant modes of single disk which are degenerate because of the opposite symmetry. Approaching of the second disk removes this degeneracy because of interaction between the disks. As a result at certain distances we realize the hybridized anti-bonding resonant modes whose morphology becomes close to the spherical Mie resonant mode with high orbital index. Respectively the Q factor of the anti-bonding resonant mode can be enhanced by three orders of magnitude compared to the case of single disk.
Development of qPCR Detection Assay for Potato Pathogen Pectobacterium atrosepticum Based on a Unique Target Sequence
Authors: Lukianova Anna A. , Evseev Peter V. , Stakheev Alexander A. , Kotova Irina B. , Zavriev Sergey K. , Ignatov Alexander N. , Miroshnikov Konstantin A.
Published: February 2021

The recent taxonomic diversification of bacterial genera Pectobacterium and Dickeya, which cause soft rot in plants, focuses attention on the need for improvement of existing methods for the detection and differentiation of these phytopathogens. This research presents a whole genome-based approach to the selection of marker sequences unique to particular species of Pectobacterium. The quantitative real-time PCR assay developed is selective in the context of all tested Pectobacterium atrosepticum strains and is able to detect fewer than 102 copies of target DNA per reaction. The presence of plant DNA extract did not affect the sensitivity of the assay.
Plant Nitric Oxide Signaling under Drought Stress
Authors: Lau Su-Ee , Hamdan Mohd Fadhli , Pua Teen-Lee , Saidi Noor Baity , Tan Boon Chin
Published: February 2021

Water deficit caused by drought is a significant threat to crop growth and production. Nitric oxide (NO), a water- and lipid-soluble free radical, plays an important role in cytoprotection. Apart from a few studies supporting the role of NO in drought responses, little is known about this pivotal molecular amendment in the regulation of abiotic stress signaling. In this review, we highlight the knowledge gaps in NO roles under drought stress and the technical challenges underlying NO detection and measurements, and we provide recommendations regarding potential avenues for future investigation. The modulation of NO production to alleviate abiotic stress disturbances in higher plants highlights the potential of genetic manipulation to influence NO metabolism as a tool with which plant fitness can be improved under adverse growth conditions.
Mixed Models as a Tool for Comparing Groups of Time Series in Plant Sciences
Authors: Spyroglou Ioannis , Skalák Jan , Balakhonova Veronika , Benedikty Zuzana , Rigas Alexandros G. , Hejátko Jan
Published: February 2021

Plants adapt to continual changes in environmental conditions throughout their life spans. High-throughput phenotyping methods have been developed to noninvasively monitor the physiological responses to abiotic/biotic stresses on a scale spanning a long time, covering most of the vegetative and reproductive stages. However, some of the physiological events comprise almost immediate and very fast responses towards the changing environment which might be overlooked in long-term observations. Additionally, there are certain technical difficulties and restrictions in analyzing phenotyping data, especially when dealing with repeated measurements. In this study, a method for comparing means at different time points using generalized linear mixed models combined with classical time series models is presented. As an example, we use multiple chlorophyll time series measurements from different genotypes. The use of additional time series models as random effects is essential as the residuals of the initial mixed model may contain autocorrelations that bias the result. The nature of mixed models offers a viable solution as these can incorporate time series models for residuals as random effects. The results from analyzing chlorophyll content time series show that the autocorrelation is successfully eliminated from the residuals and incorporated into the final model. This allows the use of statistical inference.
A Systems Biology Approach to Identify Essential Epigenetic Regulators for Specific Biological Processes in Plants
Authors: McCoy Rachel M. , Julian Russell , Kumar Shoban R. V. , Ranjan Rajeev , Varala Kranthi , Li Ying
Published: February 2021

Upon sensing developmental or environmental cues, epigenetic regulators transform the chromatin landscape of a network of genes to modulate their expression and dictate adequate cellular and organismal responses. Knowledge of the specific biological processes and genomic loci controlled by each epigenetic regulator will greatly advance our understanding of epigenetic regulation in plants. To facilitate hypothesis generation and testing in this domain, we present EpiNet, an extensive gene regulatory network (GRN) featuring epigenetic regulators. EpiNet was enabled by (i) curated knowledge of epigenetic regulators involved in DNA methylation, histone modification, chromatin remodeling, and siRNA pathways; and (ii) a machine-learning network inference approach powered by a wealth of public transcriptome datasets. We applied GENIE3, a machine-learning network inference approach, to mine public Arabidopsis transcriptomes and construct tissue-specific GRNs with both epigenetic regulators and transcription factors as predictors. The resultant GRNs, named EpiNet, can now be intersected with individual transcriptomic studies on biological processes of interest to identify the most influential epigenetic regulators, as well as predicted gene targets of the epigenetic regulators. We demonstrate the validity of this approach using case studies of shoot and root apical meristem development.
Prokaryotic Expression of Phosphoenolpyruvate Carboxylase Fragments from Peanut and Analysis of Osmotic Stress Tolerance of Recombinant Strains
Authors: Tu Jiaqi , Feng Lanlan , Hong Yanbin , Liu Qiuyun , Huang Xia , Li Yin
Published: February 2021

Phosphoenolpyruvate carboxylase (PEPC) is a ubiquitous cytosolic enzyme that catalyzes the irreversible β-carboxylation of phosphoenolpyruvate (PEP) in presence of HCO3− to produce oxaloacetate (OAA) during carbon fixation and photosynthesis. It is well accepted that PEPC genes are expressed in plants upon stress. PEPC also supports the biosynthesis of biocompatible osmolytes in many plant species under osmotic stress. There are five isoforms of PEPC found in peanut (Arachis hypogaea L.), namely, AhPEPC1, AhPEPC2, AhPEPC3, AhPEPC4, and AhPEPC5. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis revealed that the gene expression patterns of these AhPEPC genes were different in mature seeds, stems, roots, flowers, and leaves. The expression of all the plant type PEPC (PTPCs) (AhPEPC1, AhPEPC2, AhPEPC3, and AhPEPC4) was relatively high in roots, while the bacterial type PEPC (BTPC) (AhPEPC5) showed a remarkable expression level in flowers. Principal component analysis (PCA) result showed that AhPEPC3 and AhPEPC4 are correlated with each other, indicating comparatively associations with roots, and AhPEPC5 have a very close relationship with flowers. In order to investigate the function of these AhPEPCs, the fragments of these five AhPEPC cDNA were cloned and expressed in Escherichia coli (E. coli). The recombinant proteins contained a conserved domain with a histidine site, which is important for enzyme catalysis. Results showed that protein fragments of AhPEPC1, AhPEPC2, and AhPEPC5 had remarkable expression levels in E. coli. These three recombinant strains were more sensitive at pH 9.0, and recombinant strains carrying AhPEPC2 and AhPEPC5 fragments exhibited more growth than the control strain with the presence of PEG6000. Our findings showed that the expression of the AhPEPC fragments may enhance the resistance of transformed E. coli to osmotic stress.
Downstream Signalling from Molecular Hydrogen
Authors: Hancock John T. , Russell Grace
Published: February 2021

Molecular hydrogen (H2) is now considered part of the suite of small molecules that can control cellular activity. As such, H2 has been suggested to be used in the therapy of diseases in humans and in plant science to enhance the growth and productivity of plants. Treatments of plants may involve the creation of hydrogen-rich water (HRW), which can then be applied to the foliage or roots systems of the plants. However, the molecular action of H2 remains elusive. It has been suggested that the presence of H2 may act as an antioxidant or on the antioxidant capacity of cells, perhaps through the scavenging of hydroxyl radicals. H2 may act through influencing heme oxygenase activity or through the interaction with reactive nitrogen species. However, controversy exists around all the mechanisms suggested. Here, the downstream mechanisms in which H2 may be involved are critically reviewed, with a particular emphasis on the H2 mitigation of stress responses. Hopefully, this review will provide insight that may inform future research in this area.
Study of an Online Monitoring Adaptive System for an Injection Molding Process Based on a Nozzle Pressure Curve
Authors: Fan-Jiang Jia-Chen , Su Chi-Wei , Liou Guan-Yan , Hwang Sheng-Jye , Lee Huei-Huang , Peng Hsin-Shu , Chu Hsiao-Yeh
Published: February 2021

Injection molding is a popular process for the mass production of polymer products, but due to the characteristics of the injection process, there are many factors that will affect the product quality during the long fabrication processes. In this study, an adaptive adjustment system was developed by C++ programming to adjust the V/P switchover point and injection speed during the injection molding process in order to minimize the variation of the product weight. Based on a series of preliminary experiments, it was found that the viscosity index and peak pressure had a strong correlation with the weight of the injection-molded parts. Therefore, the viscosity index and peak pressure are used to guide the adjustment in the presented control system, and only one nozzle pressure sensor is used in the system. The results of the preliminary experiments indicate that the reduction of the packing time and setting enough clamping force can decrease the variation of the injected weight without turning on the adaptive control system; meanwhile, the master pressure curve obtained from the preliminary experiment was used as the control target of the system. With this system, the variation of the product weight and coefficient of variation (CV) of the product weight can be decreased to 0.21 and 0.05%, respectively.
Steroid Eluting Esophageal-Targeted Drug Delivery Devices for Treatment of Eosinophilic Esophagitis
Authors: Prasher Alka , Shrivastava Roopali , Dahl Denali , Sharma-Huynh Preetika , Maturavongsadit Panita , Pridgen Tiffany , Schorzman Allison , Zamboni William , Ban Jisun , Blikslager Anthony , Dellon Evan S. , Benhabbour Soumya Rahima
Published: February 2021

Eosinophilic esophagitis (EoE) is a chronic atopic disease that has become increasingly prevalent over the past 20 years. A first-line pharmacologic option is topical/swallowed corticosteroids, but these are adapted from asthma preparations such as fluticasone from an inhaler and yield suboptimal response rates. There are no FDA-approved medications for the treatment of EoE, and esophageal-specific drug formulations are lacking. We report the development of two novel esophageal-specific drug delivery platforms. The first is a fluticasone-eluting string that could be swallowed similar to the string test “entero-test” and used for overnight treatment, allowing for a rapid release along the entire length of esophagus. In vitro drug release studies showed a target release of 1 mg/day of fluticasone. In vivo pharmacokinetic studies were carried out after deploying the string in a porcine model, and our results showed a high local level of fluticasone in esophageal tissue persisting over 1 and 3 days, and a minimal systemic absorption in plasma. The second device is a fluticasone-eluting 3D printed ring for local and sustained release of fluticasone in the esophagus. We designed and fabricated biocompatible fluticasone-loaded rings using a top-down, Digital Light Processing (DLP) Gizmo 3D printer. We explored various strategies of drug loading into 3D printed rings, involving incorporation of drug during the print process (pre-loading) or after printing (post-loading). In vitro drug release studies of fluticasone-loaded rings (pre and post-loaded) showed that fluticasone elutes at a constant rate over a period of one month. Ex vivo pharmacokinetic studies in the porcine model also showed high tissue levels of fluticasone and both rings and strings were successfully deployed into the porcine esophagus in vivo. Given these preliminary proof-of-concept data, these devices now merit study in animal models of disease and ultimately subsequent translation to testing in humans.
Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue
Authors: Zhu Wenhui , Zhang Caiyun , Chen Yali , Deng Qiliang
Published: February 2021

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.
Updates to TRACK_TEST and TRACK_VISION Computer Programs
Authors: Nikezic Dragoslav , Stajic Jelena M. , Yu Kwan Ngok
Published: February 2021

The computer programs TRACK_TEST and TRACK_VISION were previously developed to model profiles and optical appearances of tracks developed in solid-state nuclear track detectors. The programs were based on a track development model that involved the bulk etch rate Vb and the track etch rate Vt or the V function (i.e., Vt/Vb). The present work reported our work to update and modify these two programs. In the revised TRACK_TEST, two new V functions were added and enabled. Sample results for the CR-39 detector obtained using the three original and the two new V functions were compared. Discrepancies were within ~10% and <14% for incident alpha-particle energies of 1 MeV and >1 MeV, respectively. Another major revision of TRACK_TEST was to enable calculations for the Makrofol detector. In the revised TRACK_VISION, the two new V functions, as well as the option for the Makrofol detector, were also added. The experimental results on the Makrofol detectors were obtained (irradiated with 3.6-MeV alpha particles under normal incidence and then etched to achieve a removed detector thickness of 30 μm) for comparisons with the modeled results using the revised TRACK_VISION. The track diameters obtained from the experiment and model were 24.7 and 23.2 μm, respectively. Moreover, a bright area in the central parts, together with an outer dark ring, were present in both the simulated and experimental tracks. The track-opening diameters and the general optical appearances of the tracks were in good agreement.
Poly(Vinyl Chloride) Spheres Coated with Graphene Oxide Sheets: From Synthesis to Optical Properties and Their Applications as Flame-Retardant Agents
Authors: Baibarac Mihaela , Stingescu Luiza , Stroe Malvina , Negrila Catalin , Matei Elena , Cotet Liviu C. , Anghel Ion , Şofran Ioana E. , Baia Lucian
Published: February 2021

A new method to obtain poly(vinyl chloride) (PVC) spheres, which consists of an interaction between commercial PVC grains and hexyl ethyl cellulose and lauroyl peroxide at a temperature of 60 °C, is reported. The addition of the graphene oxide (GO) sheets dispersed in dimethylformamide to the reaction mixture leads to the generation of composites made of PVC spheres coated with GO sheets. Scanning electron microscopy studies have demonstrated that this method allows for the transformation of PVC grains with sizes between 75 and 227 μm into spheres with sizes varying from 0.7 to 3.5 μm when the GO concentration in the PVC/GO composite mass increases from 0.5 to 5 wt.%. Our studies of Raman scattering and FTIR spectroscopy highlight a series of changes that indicate the appearance of ClCH=CH–, CH2=CCl–, and/or –CH=CCl– units as a result of PVC partial dehydrogenation. New –COO– and C–OH bonds on the GO sheet surfaces are induced during the preparation of PVC spheres coated with GO sheets. A photoluminescence (PL) band with a maximum at 325 nm is reported to characterize the PVC spheres. A PVC PL quenching process is demonstrated to be induced by the increase in the concentration of the GO sheets in the PVC/GO composite mass. The perspectives regarding the use of this composite as a flame-retardant material are also reported.
Effects of Alkyl-Substituted Polybenzoxazines on Tribological Properties of Non-Asbestos Composite Friction Materials
Authors: Wongpayakyotin Anun , Jubsilp Chanchira , Tiptipakorn Sunan , Mora Phattarin , Bielawski Christopher W. , Rimdusit Sarawut
Published: February 2021

A series of substituted polybenzoxazines was synthesized and studied as binders in non-asbestos friction composite materials. The structures of the polybenzoxazines were varied in a systemic fashion by increasing the number and position of pendant alkyl (methyl) groups and was accomplished using the respective aromatic amines during the polymer synthesis step. By investigating the key thermomechanical and tribological characteristics displayed by the composite materials, the underlying structure-properties relationships were deconvoluted. Composite friction materials with higher thermomechanical and wear resistance properties were obtained from polybenzoxazines with relatively high crosslink densities. In contrast, polybenzoxazines with relatively low crosslink densities afforded composite friction materials with an improved coefficient of friction values and specific wear rates.
Towards Next-Generation Sustainable Composites Made of Recycled Rubber, Cenospheres, and Biobinder
Authors: Irtiseva Kristine , Lapkovskis Vjaceslavs , Mironovs Viktors , Ozolins Jurijs , Thakur Vijay Kumar , Goel Gaurav , Baronins Janis , Shishkin Andrei
Published: February 2021

The utilisation of industrial residual products to develop new value-added materials and reduce their environmental footprint is one of the critical challenges of science and industry. Development of new multifunctional and bio-based composite materials is an excellent opportunity for the effective utilisation of residual industrial products and a right step in the Green Deal’s direction as approved by the European Commission. Keeping the various issues in mind, we describe the manufacturing and characterisation of the three-component bio-based composites in this work. The key components are a bio-based binder made of peat, devulcanised crumb rubber (DCR) from used tyres, and part of the fly ash, i.e., the cenosphere (CS). The three-phase composites were prepared in the form of a block to investigate their mechanical properties and density, and in the form of granules for the determination of the sorption of water and oil products. We also investigated the properties’ dependence on the DCR and CS fraction. It was found that the maximum compression strength (in block form) observed for the composition without CS and DCR addition was 79.3 MPa, while the second-highest value of compression strength was 11.2 MPa for the composition with 27.3 wt.% of CS. For compositions with a bio-binder content from 17.4 to 55.8 wt.%, and with DCR contents ranging from 11.0 to 62.0 wt.%, the compressive strength was in the range from 1.1 to 2.0 MPa. Liquid-sorption analysis (water and diesel) showed that the maximum saturation of liquids, in both cases, was set after 35 min and ranged from 1.05 to 1.4 g·g −1 for water, and 0.77 to 1.25 g·g−1 for diesel. It was observed that 90% of the maximum saturation with diesel fuel came after 10 min and for water after 35 min.
Bio-Based Polyurethane Foams with Castor Oil Based Multifunctional Polyols for Improved Compressive Properties
Authors: Lee Joo Hyung , Kim Seong Hun , Oh Kyung Wha
Published: February 2021

Currently, most commercial polyols used in the production of polyurethane (PU) foam are derived from petrochemicals. To address concerns relating to environmental pollution, a sustainable resource, namely, castor oil (CO), was used in this study. To improve the production efficiency, sustainability, and compressive strength of PU foam, which is widely used as an impact-absorbing material for protective equipment, PU foam was synthesized with CO-based multifunctional polyols. CO-based polyols with high functionalities were synthesized via a facile thiol-ene click reaction method and their chemical structures were analyzed. Subsequently, a series of polyol blends of castor oil and two kinds of castor oil-based polyols with different hydroxyl values was prepared and the viscosity of the blends was analyzed. Polyurethane foams were fabricated from the polyol blends via a free-rising method. The effects of the composition of the polyol blends on the structural, morphological, mechanical, and thermal properties of the polyurethane foams were investigated. The results demonstrated that the fabrication of polyurethane foams from multifunctional polyol blends is an effective way to improve their compressive properties. We expect these findings to widen the range of applications of bio-based polyurethane foams.
Change in Mixing Power of a Two-PBT Impeller When Emptying a Tank
Authors: Stelmach Jacek , Kuncewicz Czesław , Adrian Łukasz , Jirout Tomaš , Rieger Frantisek
Published: February 2021

The paper presents research on the phenomenon of an increase in mixing power during the emptying of a tank with two 6-PBT45° axial impellers in operation, located on a common shaft, pumping the liquid to the bottom of the mixing tank. A large increase in mixing power took place when the free surface of the liquid was just above the upper edge of one of the impellers (hp/D < 0.1). This increase was even more than 50% compared to the design power for a fully filled mixing vessel. Admittedly, high motor overload, while not very long, may damage it. The study investigated the instantaneous torques acting on the impeller shaft during the emptying of the tank and the velocity distributions in planes r-z. On their basis, the mechanism of the phenomenon observed was determined and correlation relationships were given that permitted the calculation of the numerical values of the power increase factors.
Semi-Batch Gasification of Refuse-Derived Fuel (RDF)
Authors: Haydary Juma , Šuhaj Patrik , Šoral Michal
Published: February 2021

Gasification is a promising technology for the conversion of mixed solid waste like refuse-derived fuel (RDF) and municipal solid waste (MSW) into a valuable gas consisting of H2, CO, CH4 and CO2. This work aims to identify the basic challenges of a single-stage batch gasification system related to tar and wax content in the producer gas. RDF was first gasified in a simple semi-batch laboratory-scale gasification reactor. A significant yield of tars and waxes was received in the produced gas. Waxes were analyzed using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectrometry. These analyses indicated the presence of polyethylene and polypropylene chains. The maximum content of H2 and CO was measured 500 sec after the start of the process. In a second series of experiments, a secondary catalytic stage with an Ni-doped clay catalyst was installed. In the two-stage catalytic process, no waxes were captured in isopropanol and the total tar content decreased by approximately 90 %. A single one-stage semi-batch gasification system is not suitable for RDF gasification; a large fraction of tar and waxes can be generated which can cause fouling in downstream processes. A secondary catalytic stage can significantly reduce the tar content in gas.
Agro-Food Residues and Bioethanol Potential: A Study for a Specific Area
Authors: Basaglia Marina , D’Ambra Massimiliano , Piubello Giuseppe , Zanconato Veronica , Favaro Lorenzo , Casella Sergio
Published: February 2021

Bioethanol obtained from agro-food wastes could contribute to decrease the dependency on fossil resources, reduce the impact of fossil fuels on the environment, and mitigate the food versus fuel debate. This study is aimed to investigate the availability of residual inexpensive agro-food biomasses that could feed a second-generation bioethanol plant located in a specific area of North Eastern Italy. After the identification of all crops in the area, more than 40 agro-food residues were analyzed for their availability and compositions in terms of water, polysaccharides, and sugars potentially convertible into bioethanol. 574,166 Mg of residual wet lignocellulosic biomass corresponding to 297,325 Mg of dry material were found available for bioethanol conversion. The most promising substrates were wheat straw and vine shoots. Based on the chemical composition of residues, the potential attainable ethanol was determined. Theoretical potential ethanol production was estimated at nearly 72,000 Mg per year. This quantity extensively exceeds the minimum yearly capacity of a sustainable bioethanol plant previously identified as around 50,000 Mg of ethanol. Taken together, these results demonstrate that, in the analyzed area, agro-food residues are available in an amount that could sustain bioethanol production in a specific and restricted district. Techno-economical evaluations are in progress to assess the actual feasibility of installing a second generation bioethanol production plant in the area of interest.
Versatility of Reverse Micelles: From Biomimetic Models to Nano (Bio)Sensor Design
Authors: Arsene Melania-Liliana , Răut Iuliana , Călin Mariana , Jecu Maria-Luiza , Doni Mihaela , Gurban Ana-Maria
Published: February 2021

This paper presents an overview of the principal structural and dynamics characteristics of reverse micelles (RMs) in order to highlight their structural flexibility and versatility, along with the possibility to modulate their parameters in a controlled manner. The multifunctionality in a large range of different scientific fields is exemplified in two distinct directions: a theoretical model for mimicry of the biological microenvironment and practical application in the field of nanotechnology and nano-based sensors. RMs represent a convenient experimental approach that limits the drawbacks of the conventionally biological studies in vitro, while the particular structure confers them the status of simplified mimics of cells by reproducing a complex supramolecular organization in an artificial system. The biological relevance of RMs is discussed in some particular cases referring to confinement and a crowded environment, as well as the molecular dynamics of water and a cell membrane structure. The use of RMs in a range of applications seems to be more promising due to their structural and compositional flexibility, high efficiency, and selectivity. Advances in nanotechnology are based on developing new methods of nanomaterial synthesis and deposition. This review highlights the advantages of using RMs in the synthesis of nanoparticles with specific properties and in nano (bio)sensor design.
Solubility of Rare Earth Chlorides in Ternary Water-Salt Systems in the Presence of a Fullerenol—C60(OH)24 Nanoclusters at 25 °C. Models of Nonelectrolyte Solubility in Electrolyte Solutions
Authors: Charykov Nikolay A. , Keskinov Viktor A. , Tsvetkov Kirill A. , Kanbar Ayat , Semenov Konstantin N. , Gerasimova Lubov’ V. , Shaimardanov Zhassulan K. , Shaimardanova Botagoz K. , Kulenova Natalia A.
Published: February 2021

The solubility in triple water-salt systems containing NdCl3, PrCl3, YCl3, TbCl3 chlorides, and water-soluble fullerenol C60(OH)24 at 25 °C was studied by isothermal saturation in ampoules. The analysis for the content of rare earth elements was carried out by atomic absorption spectroscopy, for the content of fullerenol—by electronic spectrophotometry. The solubility diagrams in all four ternary systems are simple eutonic, both consisting of two branches, corresponding to the crystallization of fullerenol crystal-hydrate and rare earth chloride crystal-hydrates, and containing one nonvariant point corresponding to the saturation of both solid phases. On the long branches of C60(OH)24*18H2O crystallization, a C60(OH)24 decreases by more than 2 orders of magnitude compared to the solubility of fullerenol in pure water (salting-out effect). On very short branches of crystallization of NdCl3*6H2O, PrCl3*7H2O, YCl3*6H2O, and TbCl3*6H2O, the salting-in effect is clearly observed, and the solubility of all four chlorides increases markedly. The four diagrams cannot be correctly approximated by the simple one-term Sechenov equation (SE-1), and very accurately approximated by the three-term modified Sechenov equation (SEM-3). Both equations for the calculation of nonelectrolyte solubility in electrolyte solutions (SE-1 and SEM-3 models) are obtained, using Pitzer model of virial decomposition of excess Gibbs energy of electrolyte solution. It is shown that semi-empirical equations of SE-1 and SEM-3 models may be extended to the systems with crystallization of crystal-solvates.
Optimization of Metal Recovery from MSWI Fly Ash by Acid Leaching: Findings from Laboratory- and Industrial-Scale Experiments
Authors: Weibel Gisela , Zappatini Anna , Wolffers Mirjam , Ringmann Stefan
Published: February 2021

A major part of Swiss fly ashes (FA) from municipal solid waste incineration (MSWI) are treated with the acid fly ash leaching process (FLUWA) in order to recover heavy metals prior to deposition. The FLUWA process uses scrub water from wet flue gas cleaning to leach heavy metals from FA. The leaching efficiency is strongly dependent on the leaching conditions (e.g., pH, Eh, L/S-ratio). This case study presents the optimization of the FLUWA process at the MSWI plant Linth, Switzerland, through determination of ideal process parameters for optimal metal recovery. By means of laboratory- and industrial-scale experiments, the process was adjusted towards a more efficient leaching of Zn, Pb, Cu, and Cd. This included the use of an oxidizing agent (hydrogen peroxide). Laboratory experiments proved to be a powerful tool for simulating process optimizations at industrial scale. An ideal leaching pH of 3.8 was determined and it was observed that the process stability is significantly influenced by the L/S-ratio applied to the leaching process. In the course of the study, the recovery could be improved to 67% Zn, 66% Pb, 30% Cu, and 91% Cd. It can be concluded that for optimal metal recovery the process has to be individually adjusted to the composition of the processed FA and scrub water of each specific FLUWA process.
A Discrete Multi-Physics Model to Simulate Fluid Structure Interaction and Breakage of Capsules Filled with Liquid under Coaxial Load
Authors: Ruiz-Riancho Ignacio , Alexiadis Alessio , Zhang Zhibing , Garcia Hernandez Alvaro
Published: February 2021

This paper investigated the mechanical response (including breakage and release of the internal liquid) of single core–shell capsules under compression by means of discrete multi-physics. The model combined Smoothed Particle Hydrodynamics for modelling the fluid and the Lattice Spring Model for the elastic membrane. Thanks to the meshless nature of discrete multi-physics, the model can easily account for the fracture of the capsule’s shell and the interactions between the internal liquid and the solid shell. The simulations replicated a parallel plate compression test of a single core–shell capsule. The inputs of the model were the size of the capsule, the thickness of the shell, the geometry of the internal structure, the Young’s modulus of the shell material, and the fluid’s density and viscosity. The outputs of the model were the fracture type, the maximum force needed for the fracture, and the force–displacement curve. The data were validated by reproducing equivalent experimental tests in the laboratory. The simulations accurately reproduced the breakage of capsules with different mechanical properties. The proposed model can be used as a tool for designing capsules that, under stress, break and release their internal liquid at a specific time.
Lake Sedimentary DNA Research on Past Terrestrial and Aquatic Biodiversity: Overview and Recommendations
Authors: Capo Eric , Giguet-Covex Charline , Rouillard Alexandra , Nota Kevin , Heintzman Peter D. , Vuillemin Aurèle , Ariztegui Daniel , Arnaud Fabien , Belle Simon , Bertilsson Stefan , Bigler Christian , Bindler Richard , Brown Antony G. , Clarke Charlotte L. , Crump Sarah E. , Debroas Didier , Englund Göran , Ficetola Gentile Francesco , Garner Rebecca E. , Gauthier Joanna , Gregory-Eaves Irene , Heinecke Liv , Herzschuh Ulrike , Ibrahim Anan , Kisand Veljo , Kjær Kurt H. , Lammers Youri , Littlefair Joanne , Messager Erwan , Monchamp Marie-Eve , Olajos Fredrik , Orsi William , Pedersen Mikkel W. , Rijal Dilli P. , Rydberg Johan , Spanbauer Trisha , Stoof-Leichsenring Kathleen R. , Taberlet Pierre , Talas Liisi , Thomas Camille , Walsh David A. , Wang Yucheng , Willerslev Eske , van Woerkom Anne , Zimmermann Heike H. , Coolen Marco J. L. , Epp Laura S. , Domaizon Isabelle , G. Alsos Inger , Parducci Laura
Published: February 2021

The use of lake sedimentary DNA to track the long-term changes in both terrestrial and aquatic biota is a rapidly advancing field in paleoecological research. Although largely applied nowadays, knowledge gaps remain in this field and there is therefore still research to be conducted to ensure the reliability of the sedimentary DNA signal. Building on the most recent literature and seven original case studies, we synthesize the state-of-the-art analytical procedures for effective sampling, extraction, amplification, quantification and/or generation of DNA inventories from sedimentary ancient DNA (sedaDNA) via high-throughput sequencing technologies. We provide recommendations based on current knowledge and best practises.
Cultural Diversity and Religious Reflexivity in an Intercultural Chilean Parish
Authors: Orellana Felipe
Published: February 2021

This research aims to analyze cultural diversity and its relationship with the personal belief in an Immigrant Parish. The discussion is framed within the topic of intercultural churches and parishes, although in a setting that has not been researched (Santiago, Chile). The research was carried out in the Latin-American Parish placed in Providencia, Santiago, and a qualitative framework was used to obtain and analyze the data. Cultural diversity is understood concerning religious reflexivity and under the idea that pluralism leads to a weakening of religious conviction, as Peter Berger argued. The theoretical framework makes the difference between the vision of Berger on cultural pluralism (pluralism inter-religion) and the viewpoint by Charles Taylor (pluralism intra-religion). On the contrary to Berger, the findings of this research showed that cultural diversity and pluralism are elements that produce a strengthening of individual beliefs.
Campus Violence Detection Based on Artificial Intelligent Interpretation of Surveillance Video Sequences
Authors: Ye Liang , Liu Tong , Han Tian , Ferdinando Hany , Seppänen Tapio , Alasaarela Esko
Published: February 2021

Campus violence is a common social phenomenon all over the world, and is the most harmful type of school bullying events. As artificial intelligence and remote sensing techniques develop, there are several possible methods to detect campus violence, e.g., movement sensor-based methods and video sequence-based methods. Sensors and surveillance cameras are used to detect campus violence. In this paper, the authors use image features and acoustic features for campus violence detection. Campus violence data are gathered by role-playing, and 4096-dimension feature vectors are extracted from every 16 frames of video images. The C3D (Convolutional 3D) neural network is used for feature extraction and classification, and an average recognition accuracy of 92.00% is achieved. Mel-frequency cepstral coefficients (MFCCs) are extracted as acoustic features, and three speech emotion databases are involved. The C3D neural network is used for classification, and the average recognition accuracies are 88.33%, 95.00%, and 91.67%, respectively. To solve the problem of evidence conflict, the authors propose an improved Dempster–Shafer (D–S) algorithm. Compared with existing D–S theory, the improved algorithm increases the recognition accuracy by 10.79%, and the recognition accuracy can ultimately reach 97.00%.