bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Ivermectin Treatment on the Frequency of Seizures in Persons with Epilepsy Infected with Onchocerca volvulus
Authors: Dusabimana Alfred , Tsebeni Wafula Solomon , Raimon Stephen Jada , Fodjo Joseph Nelson Siewe , Bhwana Dan , Tepage Floribert , Abd-Elfarag Gasim , Hotterbeekx An , Abrams Steven , Colebunders Robert
Published: December 2020

A clinical trial performed in the Democratic Republic of Congo (DRC), among persons with epilepsy (PWE) infected with Onchocerca volvulus treated with anti-seizure medication suggested that ivermectin reduces the seizure frequency. We assessed the effect of ivermectin treatment on seizure frequency in PWE with and without anti-seizure medication in three onchocerciasis endemic areas (Maridi, South Sudan; Aketi, DRC; and Mahenge, Tanzania). Pre- and 3–5 months post-ivermectin microfilariae densities in skin snips and seizure frequency were assessed. After ivermectin, the median (IQR) percentage reduction in seizure frequency in the study sites ranged from 73.4% (26.0–90.0) to 100% (50.0–100.0). A negative binomial mixed model showed that ivermectin significantly reduced the seizure frequency, with a larger decrease in PWE with a high baseline seizure frequency. Mediation analysis showed that ivermectin reduced the seizure frequencies indirectly through reduction in microfilariae densities but also that ivermectin may have a direct anti-seizure effect. However, given the short half-life of ivermectin and the fact that ivermectin does not penetrate the healthy brain, such a direct anti-seizure effect is unlikely. A randomized controlled trial assessing the ivermectin effect in people infected with O. volvulus who are also PWE on a stable anti-seizure regimen may be needed to clarify the causal relationship between ivermectin and seizure frequency.
A Biocontrol Strain of Pseudomonas aeruginosa CQ-40 Promote Growth and Control Botrytis cinerea in Tomato
Authors: Wang Xingyuan , Zhou Xinan , Cai Zhibo , Guo Lan , Chen Xiuling , Chen Xu , Liu Jiayin , Feng Mingfang , Qiu Youwen , Zhang Yao , Wang Aoxue
Published: December 2020

Botrytis cinerea infection can be very devastating for tomato production, as it can result in a large-scale reduction in tomato fruit production and fruit quality after harvest. Thus, it negatively affects tomato yield and quality. In this study, a biocontrol bacteria CQ-4 was isolated and screened from the rhizosphere soil of tomato plants. Morphological, physiological, and biochemical characteristics and 16S rDNA sequence analysis revealed that it belongs to the species Pseudomonas aeruginosa, which has a strong antagonistic effect against Botrytis cinerea. In addition, the bacterium’s antibacterial spectrum is relatively extensive, and antagonistic tests have shown that it also has varying degrees of inhibition on other 12 plant diseases. The growth promotion test showed that the strain has a clear promotion effect on tomato seed germination and seedling growth. The growth-promoting effect on plant height, stem thickness, dry and fresh weight and main root length of tomato seedlings was significantly improved after the seeds were soaked in a bacterial solution of 2.5 × 108 cfu mL−1 concentration. This did not only maintain the nutritional quality of tomato fruits, but also prevents them from rotting. In vitro and pot experiments showed that the strain CQ-4 can effectively control tomato gray mold, and the control effects on tomato leaves and fruits reached 74.4% and 66.0%, respectively. Strain CQ-4 induce plants to up-regulate the activities of four disease-resistant defense enzymes. The peak enzymatic activities of Phenylalanine Ammonia Lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), and Superoxide Dismutase (SOD) were increased by 35.6%, 37.6%, 46.1%, and 38.4%, respectively, as compared with the control group. This study found that the strain can solubilize phosphorus, fix nitrogen, and produce cellulase, protease, ferrophilin, and other antibacterial metabolites, but it does not produce chitinase, glucanase, and HCN (hydrocyanic acid). This research screened out an excellent Pseudomonas aeruginosa strain that can stably and effectively control tomato gray mold, and it provided theoretical basis for further development and the application of biological agents.
Molecular Survey of Vector-Borne Pathogens of Dogs and Cats in Two Regions of Saudi Arabia
Authors: Alanazi Abdullah D. , Alouffi Abdulaziz S. , Alyousif Mohamed S. , Alshahrani Mohammad Y. , Abdullah Hend H. A. M. , Abdel-Shafy Sobhy , Calvani Nichola Eliza Davies , Ansari-Lari Maryam , Sazmand Alireza , Otranto Domenico
Published: December 2020

Dogs and cats play an important role as reservoirs of vector-borne pathogens, yet reports of canine and feline vector-borne diseases in Saudi Arabia are scarce. Blood samples were collected from 188 free-roaming dogs and cats in Asir (70 dogs and 44 cats) and Riyadh (74 dogs), Saudi Arabia. The presence of Anaplasma spp., Bartonella spp., hemotropic Mycoplasma spp., Babesia spp., and Hepatozoon spp. was detected using a multiplex tandem real-time PCR. PCR-positive samples were further examined with specific conventional and real-time PCR followed by sequencing. Dogs from Riyadh tested negative for all pathogens, while 46 out of 70 dogs (65.7%) and 17 out of 44 cats (38.6%) from Asir were positive for at least one pathogen. Positive dogs were infected with Anaplasma platys (57.1%), Babesia vogeli (30%), Mycoplasma haemocanis (15.7%), and Bartonella henselae (1.4%), and cats were infected with Mycoplasma haemofelis (13.6%), Candidatus Mycoplasma haemominutum (13.6%), B. henselae (9.2%), and A. platys (2.27%), all of which are reported for the first time in Saudi Arabia. Co-infection with A. platys and B. vogeli was detected in 17 dogs (24.28%), while coinfections were not detected in cats. These results suggest that effective control and public awareness strategies for minimizing infection in animals are necessary.
Diagnostic Practices and Treatment for P. vivax in the InterEthnic Therapeutic Encounter of South-Central Vietnam: A Mixed-Methods Study
Authors: Nguyen Thuan Thi , Nguyen Xa Xuan , Ronse Maya , Nguyen Quynh Truc , Ho Phuc Quang , Tran Duong Thanh , Gerrets Rene , Thriemer Kamala , Ley Benedikt , Marfurt Jutta , Price Ric N. , Grietens Koen Peeters , Gryseels Charlotte
Published: December 2020

Malaria elimination in the Greater Mekong Sub-Region is challenged by a rising proportion of malaria attributable to P. vivax. Primaquine (PQ) is effective in eliminating the parasite’s dormant liver stages and can prevent relapsing infections, but it induces severe haemolysis in patients with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, highlighting the importance of testing enzyme activity prior to treatment. A mixed-method study was conducted in south-central Vietnam to explore the factors that affect acceptability of G6PD testing, treatment-seeking behaviors, and adherence to current regimens. The majority of respondents (75.7%) were unaware of the different parasite species and rather differentiated malaria by perceived severity. People sought a diagnosis if suspected of malaria fever but not if they perceived their fevers as mild. Most respondents agreed to take prescribed medication to treat asymptomatic infection (94.1%) and to continue medication even if they felt better (91.5%). Health professionals did not have G6PD diagnostic tools nor the means to prescribe PQ safely. Adherence to treatment was linked to trust in public providers, who were perceived to make therapeutic decisions in the interest of the patient. Greater focus on providing acceptable ways of assessing G6PD deficiency will be needed to ensure the timely elimination of malaria in Vietnam.
CLOCK 3111TT Genotype Is Associated with Increased Total Cholesterol and Low-Density Lipoprotein Levels in Menopausal Women with a Body Mass Index of at Least 25 kg/m2
Authors: Semenova Natalya , Madaeva Irina , Kolesnikov Sergey , Rychkova Lyubov , Bairova Tatjana , Darenskaya Marina , Kolesnikova Lyubov
Published: December 2020

Lipid profile comparative analysis was performed to reveal the interdependence of lipids with Circadian locomoter output cycles protein kaput (CLOCK) 3111T/C gene polymorphism in menopausal women with/without a body mass index (BMI) of ≥25 kg/m2. Methods: A total of 193 female volunteers aged 45 to 60 years were divided into two groups: Those with BMI < 25 kg/m2 (control) and those with BMI ≥ 25 kg/m2. Each group was then divided into two subgroups: Those with the CLOCK TT-genotype and those with the CLOCK TC-, CC-genotypes. Lipid metabolism parameters were determined by the enzymatic method. Single-nucleotide polymorphisms (SNPs) were detected via polymerase chain reaction–restriction fragment length polymorphism technology. Results: There were no differences in CLOCK 3111T/C genotypes or allele frequency between the control and main groups. In addition, there were no differences in lipid profile parameters between women of the control group and different CLOCK 3111T/C genotypes. The total cholesterol (p = 0.041) and low-density lipoprotein cholesterol (p = 0.036) levels were higher in the subgroup of women with a BMI ≥ 25 kg/m2 and CLOCK TT-genotype as compared to the subgroup with a BMI ≥ 25 kg/m2 and minor allele 3111C. Conclusions: SNP 3111T/C of the CLOCK gene is not associated with BMI however, data suggest that the minor allele of the CLOCK 3111T/C gene polymorphism may have a protective role in atherogenic lipid levels in women with a BMI greater than or equal to 25 kg/m2.
Probing the Effects of the FGFR-Inhibitor Derazantinib on Vascular Development in Zebrafish Embryos
Authors: Kotini Maria P. , Bachmann Felix , Spickermann Jochen , McSheehy Paul M. , Affolter Markus
Published: December 2020

Angiogenesis is a fundamental developmental process and a hallmark of cancer progression. Receptor tyrosine kinases (RTK) are targets for cancer therapy which may include their action as anti-angiogenic agents. Derazantinib (DZB) is an inhibitor of the fibroblast growth factor receptors (FGFRs) 1–3 as well as other kinase targets including vascular endothelial growth factor receptor 2 (VEGFR2), colony stimulating factor-1 receptor (CSF1R) and platelet-derived growth factor beta receptor (PDGFRbeta). This study aimed to investigate the effect of DZB on blood vessel morphogenesis and to compare its activity to known specific FGFR and VEGFR inhibitors. For this purpose, we used the developing vasculature in the zebrafish embryo as a model system for angiogenesis in vivo. We show that DZB interferes with multiple angiogenic processes that are linked to FGF and VEGF signalling, revealing a potential dual role for DZB as a potent anti-angiogenic treatment.
The Neonatal and Juvenile Pig in Pediatric Drug Discovery and Development
Authors: Ayuso Miriam , Buyssens Laura , Stroe Marina , Valenzuela Allan , Allegaert Karel , Smits Anne , Annaert Pieter , Mulder Antonius , Carpentier Sebastien , Van Ginneken Chris , Van Cruchten Steven
Published: December 2020

Pharmacotherapy in pediatric patients is challenging in view of the maturation of organ systems and processes that affect pharmacokinetics and pharmacodynamics. Especially for the youngest age groups and for pediatric-only indications, neonatal and juvenile animal models can be useful to assess drug safety and to better understand the mechanisms of diseases or conditions. In this respect, the use of neonatal and juvenile pigs in the field of pediatric drug discovery and development is promising, although still limited at this point. This review summarizes the comparative postnatal development of pigs and humans and discusses the advantages of the juvenile pig in view of developmental pharmacology, pediatric diseases, drug discovery and drug safety testing. Furthermore, limitations and unexplored aspects of this large animal model are covered. At this point in time, the potential of the neonatal and juvenile pig as nonclinical safety models for pediatric drug development is underexplored.
A Comparative Exploration of Quality Assurance Results by the Third-Party Pharmaceutical Education Evaluation in Japan
Authors: Takeda Kayoko , Arakawa Naoko
Published: December 2020

Background: The Standards for the Establishment of Universities in Japan were revised; subsequently, the number of schools or universities of pharmacy/pharmaceutical sciences increased from 46 in 2002 to 74 in 2016.The pharmacy education programme was also changed from four to six years, which was implemented in 2006. In this study, we provide the comparative results of the first cycle of the third-party accrediting organization, the Japan Accreditation Board for Pharmaceutical Education (JABPE); Methods: The results of the first cycle of all universities or schools of pharmacy assessed by the JABPE from JABPE website were retrieved, and we collated and compared the results based on the 13 areas of the assessment standards; Results: In “improvements”, the number of public universities or schools was less than that of private universities or schools, and the number of old private universities or schools was also less than the number of new private universities or schools in all assessment areas. Conclusions: These results suggest that new universities or schools established since 2003 have not yet established their own quality assurance mechanism within the institutions. We need to review the Japanese pharmacy education system or the assessment criteria for it to bring about essential change.
Climate Variables Outstrip Deadwood Amount: Desiccation as the Main Trigger for Buxbaumia viridis Occurrence
Authors: Kropik Michaela , Zechmeister Harald G. , Moser Dietmar
Published: December 2020

Deadwood is a biodiversity hotspot and habitat for numerous highly endangered species. Buxbaumia viridis has been assessed as a flagship species for deadwood-rich forests and is subject to monitoring under the Habitats Directive, yet we lack a solid understanding of the factors controlling its distribution. The study aimed to specify the climate and habitat preferences of Buxbaumia viridis and identify the best predictor variables. We collected presence-absence data of the species at 201 sites between 2016 and 2020. Study sites cover three biogeographic regions (Pannonian, Continental, and Alpine). They also represent a deadwood gradient ranging from managed forests to natural forest reserves and virgin forests. Our results suggest that desiccation and deadwood amount are the best predictor variables. The amount of deadwood at the colonized sites ranged from 1 m3/ha to 288 m3/ha, with a median of 70 m3/ha. The maximum desiccation, i.e., consecutive days without rain and at least 20 °C was 9.6 days at colonized sites. The results of logistic regression models suggest that desiccation limits Buxbaumia viridis occurrence on deadwood in the drier continental parts of eastern Austria. Derived details on climate and habitat requirements of Buxbaumia viridis can specify management and conservation. They clearly show how strongly the species is dependent on climate, which can counteract deadwood measures.
Phytochemical Profile, Antioxidant, Cardioprotective and Nephroprotective Activity of Romanian Chicory Extract
Authors: Epure Alexandra , Pârvu Alina E. , Vlase Laurian , Benedec Daniela , Hanganu Daniela , Gheldiu Ana-Maria , Toma Vlad Al. , Oniga Ilioara
Published: December 2020

The present study analyzed the methanol extract and tincture obtained from the spontaneous Romanian Cichorium intybus species, in order to evaluate polyphenols content and some biological properties. Chromatographic and spectrophotometric methods were used for the analysis of polyphenols and the antioxidant capacity was assessed in vitro with DPPH● (2,2-diphenyl-picrylhydrazil) and FRAP (ferric-reducing antioxidant power) tests. The cardio-protective effects of Cichorii herba tincture on myocardial ischemia induced by isoprenaline and nephroprotection on renal failure induced by gentamicin were evaluated on rats. Also, aspartate aminotrasferase (AST), alanine aminotransferase (ALT), creatine kinase-MB (CK-MB) and creatinine clearance (CrCl) were measured. The antioxidant effect was evaluated by determining total oxidative stress (TOS), oxidative stress index (OSI, total antioxidant capacity (TAC), malondyaldehide (MDA), total thiols (SH) and total nitrites and nitrates (NOx). Cichoric acid was the main polyphenolic compound. The extracts had moderate in vitro antioxidant activity but the in vivo antioxidant and anti-inflammatory effects were significant and associated with myocardial and renal dysfunction improvement. The results were attributed to the content of polyphenols in the extracts, for which reason C. intybus may be considered an important raw material for pharmaceuticals formulations recommended in the prevention or treatment of heart or kidney diseases.
Specific PP2A Catalytic Subunits Are a Prerequisite for Positive Growth Effects in Arabidopsis Co-Cultivated with Azospirillum brasilense and Pseudomonas simiae
Authors: Averkina Irina O. , Paponov Ivan A. , Sánchez-Serrano Jose J. , Lillo Cathrine
Published: December 2020

Plant growth-promoting rhizobacteria (PGPR) stimulate plant growth, but the underlying mechanism is poorly understood. In this study, we asked whether PROTEIN PHOSPHATASE 2A (PP2A), a regulatory molecular component of stress, growth, and developmental signaling networks in plants, contributes to the plant growth responses induced by the PGPR Azospirillum brasilense (wild type strain Sp245 and auxin deficient strain FAJ0009) and Pseudomonas simiae (WCS417r). The PGPR were co-cultivated with Arabidopsis wild type (WT) and PP2A (related) mutants. These plants had mutations in the PP2A catalytic subunits (C), and the PP2A activity-modulating genes LEUCINE CARBOXYL METHYL TRANSFERASE 1 (LCMT1) and PHOSPHOTYROSYL PHOSPHATASE ACTIVATOR (PTPA). When exposed to the three PGPR, WT and all mutant Arabidopsis revealed the typical phenotype of PGPR-treated plants with shortened primary root and increased lateral root density. Fresh weight of plants generally increased when the seedlings were exposed to the bacteria strains, with the exception of catalytic subunit double mutant c2c5. The positive effect on root and shoot fresh weight was especially pronounced in Arabidopsis mutants with low PP2A activity. Comparison of different mutants indicated a significant role of the PP2A catalytic subunits C2 and C5 for a positive response to PGPR.
Use of Thidiazuron for High-Frequency Callus Induction and Organogenesis of Wild Strawberry (Fragaria vesca)
Authors: Chung Hsiao-Hang , Ouyang Hui-Yao
Published: December 2020

Strawberry, belonging to the Fragaria genus, is an important crop that produces popular fruits globally. F. vesca, known as wild strawberry, has great characteristics, such as a robust and powerful aroma, making it an important germplasm resource. The present study aims to establish an efficient regeneration method for the in vitro propagation of F. vesca. Firstly, leaf explants were used to induce callus formation on a Murashige and Skoog medium with combinations of cytokinins (thidiazuron (TDZ) and 6-benzylaminopurine (BA)) and auxin (2,4-dichlorophenoxyacetic acid (2,4-D)). Among them, 0.45–4.54 µM TDZ combined with 0.45–4.53 µM 2.4-D exhibited a high induction rate after 4 weeks of culturing. Different explants were examined for their ability to form a callus, and whole leaves on the medium containing 2.27 µM TDZ and 2.27 µM 2,4-D showed the highest callus induction rate at 100% after 2 weeks of culturing in darkness. The highest shoot regeneration ability through organogenesis from the callus was obtained at 0.44 µM BA. After 2 weeks of culturing, the shoot regeneration rate and shoot number per explant were 96% and 19.4 shoots on an average, respectively. Rooting of shoots was achieved using indole-3-butyric acid (IBA) or an α-naphthaleneacetic acid (NAA)-containing medium, and the resulting plantlets were acclimatized successfully and formed flowers eventually. In this report, we demonstrated that shoot organogenesis was derived from the meristematic cells of calli and by transferring the induced calli to a 0.44 µM BA medium, the regeneration period can be shortened greatly. A protocol for the efficient regeneration of wild strawberry was established, which might be useful for their large-scale propagation or obtaining transgenic plants in the future.
Antioxidant, Anti-tyrosinase, Anti-α-amylase, and Cytotoxic Potentials of the Invasive Weed Andropogon virginicus
Authors: Anh La Hoang , Quan Nguyen Van , Lam Vu Quang , Iuchi Yu , Takami Akiyoshi , Teschke Rolf , Xuan Tran Dang
Published: December 2020

Andropogon virginicus is an invasive weed that seriously threatens agricultural production and economics worldwide. In this research, dried aerial parts of A. virginicus were extracted, applying Soxhlet and liquid-liquid phase methods to acquire the total crude (T-Anvi), hexane (H-Anvi), ethyl acetate (E-Anvi), butanol (B-Anvi), and water (W-Anvi) extracts, respectively. In which, T-Anvi contains the highest total phenolic and flavonoid contents (24.80 mg gallic acid and 37.40 mg rutin equivalents per g dry weight, respectively). Via anti-radical (ABTS and DPPH), and reducing power assays, E-Anvi exhibits the most potent activities (IC50 = 13.96, 43.59 and 124.11 µg/mL, respectively), stronger than butylated hydroxytoluene (BHT), a standard antioxidant, while the lipid peroxidation inhibitory effect of E-Anvi (LPI = 90.85% at the concentration of 500 µg/mL) is close to BHT. E-Anvi shows the most substantial inhibition (IC50 = 2.58 mg/mL) on tyrosinase. Notably, α-amylase is significantly suppressed by H-Anvi (IC50 = 0.72 mg/mL), over twice stronger than the positive control, palmitic acid. In the cytotoxic assay, E-Anvi is the strongest extract inhibiting K562 cells (IC50 = 112.01 µg/mL). Meanwhile, T-Anvi shows the highest prevention on Meg-01 expansion (IC50 = 91.40 µg/mL). Dominant compounds detected in E-Anvi by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) are identified as flavonoids. However, among four major compounds identified in H-Anvi by gas chromatography-mass spectrometry (GC-MS), palmitic acid and phytol are the most abundant compounds with peak areas of 27.97% and 16.42%, respectively. In essence, this is the first report describing that A. virginicus is a potential natural source of antioxidants, tyrosinase and α-amylase inhibitors, and anti-chronic myeloid leukemia (CML) agents which may be useful in future therapeutics as promising alternative medicines.
Somatic Embryogenesis in Centaurium erythraea Rafn—Current Status and Perspectives: A Review
Authors: Simonović Ana D. , M. Trifunović-Momčilov Milana , Filipović Biljana K. , Marković Marija P. , Bogdanović Milica D. , Subotić Angelina R.
Published: December 2020

Centaurium erythraea (centaury) is a traditionally used medicinal plant, with a spectrum of secondary metabolites with confirmed healing properties. Centaury is an emerging model in plant developmental biology due to its vigorous regenerative potential and great developmental plasticity when cultured in vitro. Hereby, we review nearly two decades of research on somatic embryogenesis (SE) in centaury. During SE, somatic cells are induced by suitable culture conditions to express their totipotency, acquire embryogenic characteristics, and eventually give rise to somatic embryos. When SE is initiated from centaury root explants, the process occurs spontaneously (on hormone-free medium), directly (without the callusing phase), and the somatic embryos are of unicellular origin. SE from leaf explants has to be induced by plant growth regulators and is indirect (preceded by callusing). Histological observations and culture conditions are compared in these two systems. The changes in antioxidative enzymes were followed during SE from the leaf explants. Special focus is given to the role of arabinogalactan proteins during SE, which were analyzed using a variety of approaches. The newest and preliminary results, including centaury transcriptome, novel potential SE markers, and novel types of arabinogalactan proteins, are discussed as perspectives of centaury research.
The Effects of Unbleached and Bleached Nanocellulose on the Thermal and Flammability of Polypropylene-Reinforced Kenaf Core Hybrid Polymer Bionanocomposites
Authors: Sabaruddin Fatimah Athiyah , Paridah M.T. , Sapuan S. M. , Ilyas R. A. , Lee Seng Hua , Abdan Khalina , Mazlan Norkhairunnisa , Roseley Adlin Sabrina Muhammad , Abdul Khalil H.P.S.
Published: December 2020

The thermal, thermo-mechanical and flammability properties of kenaf core hybrid polymer nanocomposites reinforced with unbleached and bleached nanocrystalline cellulose (NCC) were studied. The studied chemical composition found that unbleached NCC (NCC-UB) had 90% more lignin content compared to bleached NCC (NCC-B). Nanocelluloses were incorporated within polypropylene (PP) as the matrix, together with kenaf core as a main reinforcement and maleic anhydride grafted polypropylene (MAPP) as a coupling agent via a melt mixing compounding process. The result showed that the thermal stability of the nanocomposites was generally affected by the presence of lignin in NCC-UB and sulfate group on the surface of NCC-B. The residual lignin in NCC-UB appeared to overcome the poor thermal stability of the composites that was caused by sulfation during the hydrolysis process. The lignin helped to promote the late degradation of the nanocomposites, with the melting temperature occurring at a relatively higher temperature of 219.1 °C for PP/NCC-UB, compared to 185.9 °C for PP/NCC-B. Between the two types of nanocomposites, PP/NCC-B had notably lower thermo-mechanical properties, which can be attributed to the poor bonding and dispersion properties of the NCC-B in the nanocomposites blend. The PP/NCC-UB showed better thermal properties due to the effect of residual lignin, which acted as a compatibilizer between NCC-UB and polymer matrix, thus improved the bonding properties. The residual lignin in PP/NCC-UB helped to promote char formation and slowed down the burning process, thus increasing the flame resistance of the nanocomposites. Overall, the residual lignin on the surface of NCC-UB appeared to aid better stability on the thermal and flammability properties of the nanocomposites.
Microstructural Origin of the Double Yield Points of the Metallocene Linear Low-Density Polyethylene (mLLDPE) Precursor Film under Uniaxial Tensile Deformation
Authors: Iqbal Obaid , Habumugisha Jean Claude , Feng Shengyao , Lin Yuanfei , Chen Wei , Yu Wancheng , Li Liangbin
Published: December 2020

The microstructural origin of the double yield points of metallocene linear low-density polyethylene (mLLDPE) precursor films has been studied with the assistance of the synchrotron radiation small- and wide-angle X-ray scattering (SAXS/WAXS). It has been shown that the microstructural origin of the double yield points is highly related to the initial orientation of the original precursor film. For less oriented mLLDPE precursor films, the rearrangement of lamellae and the appearance of the monoclinic phase are the microstructural origins of the first yield point. In comparison, for the highly-oriented mLLDPE precursor film, only the orthorhombic-monoclinic phase transition appears at the first yield point. The melting-recrystallization and the formation of the fibrillary structure happen beyond the second yield point for all studied mLLDPE precursor films. Finally, the detailed microstructural evolution roadmaps of mLLDPE precursor films under uniaxial tensile deformation have been established, which might serve as a guide for processing high-performance polymer films by post-stretching.
Effect of Material Parameter of Viscoelastic Giesekus Fluids on Extensional Properties in Spinline and Draw Resonance Instability in Isothermal Melt Spinning Process
Authors: Park Geunyeop , Yun Jangho , Lee Changhoon , Jung Hyun Wook
Published: December 2020

The draw resonance instability of viscoelastic Giesekus fluids was studied by correlating the spinline extensional features and transit times of several kinematic waves in an isothermal melt spinning process. The critical drawdown ratios were critically dependent on the Deborah number (De, the ratio of material relaxation time to process time) and a single material parameter (αG) of the Giesekus fluid. In the intermediate range of αG, the stability status changed distinctively with increasing De, i.e., the spinning system was initially stabilized and subsequently destabilized, as De increases. In this αG regime, the level of velocity and extensional-thickening rheological property in the spinline became gradually enhanced at low De and weakened at high De. The draw resonance onsets for different values of αG were determined precisely using a simple indicator composed of several kinematic waves traveling the entire spinline and period of oscillation. The change in transit times of kinematic waves for varying De adequately reflected the effect of αG on the change in stability.
LC-UV and UPLC-MS/MS Methods for Analytical Study on Degradation of Three Antihistaminic Drugs, Ketotifen, Epinastine and Emedastine: Percentage Degradation, Degradation Kinetics and Degradation Pathways at Different pH
Authors: Gumieniczek Anna , Kozak Izabela , Żmudzki Paweł , Hubicka Urszula
Published: December 2020

Evaluation of pH-dependent reactivity of drugs is an essential component in the pharmaceutical industry. Thus, the stability of three antihistaminic drugs, i.e., ketotifen, epinastine and emedastine, was tested, in solutions of five pH values, i.e., 1.0, 3.0, 7.0, 10.0 and 13.0, at high temperature (70 °C). LC-UV isocratic methods were developed to estimate percentage degradation as well as the kinetics of degradation. Generally, epinastine was shown to be the most stable compound with degradation below 14%. Emedastine was labile in all pH conditions, with degradation in the range 29.26–51.88%. Ketotifen was moderately stable at pH 1–7 (degradation ≤ 14.04%). However, at pH ≥ 10, its degradation exceeded 30%. The kinetics of degradation of ketotifen, epinastine and emedastine was shown as a pseudo-first-order reaction with the rate constants in the range 10−4–10−3 min−1 Finally, the UPLC-MS/MS method was applied to identify the main degradants and suggest degradation pathways. Degradation of ketotifen proceeded with oxidation and demethylation in the piperidine ring of the molecule. As far as epinastine was concerned, opening of the imidazole ring with formation of the amide group was observed. Unfortunately, no degradation products for emedastine were detected. The present results complete the literary data and may be important for both manufacturing of these drugs and their administration to patients.
Machine Learning for Ionic Liquid Toxicity Prediction
Authors: Wang Zihao , Song Zhen , Zhou Teng
Published: December 2020

In addition to proper physicochemical properties, low toxicity is also desirable when seeking suitable ionic liquids (ILs) for specific applications. In this context, machine learning (ML) models were developed to predict the IL toxicity in leukemia rat cell line (IPC-81) based on an extended experimental dataset. Following a systematic procedure including framework construction, hyper-parameter optimization, model training, and evaluation, the feedforward neural network (FNN) and support vector machine (SVM) algorithms were adopted to predict the toxicity of ILs directly from their molecular structures. Based on the ML structures optimized by the five-fold cross validation, two ML models were established and evaluated using IL structural descriptors as inputs. It was observed that both models exhibited high predictive accuracy, with the SVM model observed to be slightly better than the FNN model. For the SVM model, the determination coefficients were 0.9289 and 0.9202 for the training and test sets, respectively. The satisfactory predictive performance and generalization ability make our models useful for the computer-aided molecular design (CAMD) of environmentally friendly ILs.
Graphitic Carbon Nitride-Based Composite in Advanced Oxidation Processes for Aqueous Organic Pollutants Removal: A Review
Authors: Shen Yu , Dos santos-Garcia Antonio J. , Martín de Vidales María José
Published: December 2020

In recent decades, a growing number of organic pollutants released have raised worldwide concern. Graphitic carbon nitride (g-C3N4) has drawn increasing attention in environmental pollutants removal thanks to its unique electronic band structure and excellent physicochemical stability. This paper reviews the recent progress of g-C3N4-based composites as catalysts in various advanced oxidation processes (AOPs), including chemical, photochemical, and electrochemical AOPs. Strategies for enhancing catalytic performance such as element-doping, nanostructure design, and heterojunction construction are summarized in detail. The catalytic degradation mechanisms are also discussed briefly.
The Influence of Hydrodynamic Changes in a System with a Pitched Blade Turbine on Mixing Power
Authors: Stelmach Jacek , Kuncewicz Czesław , Szufa Szymon , Jirout Tomas , Rieger Frantisek
Published: December 2020

This paper presents an analysis of hydrodynamics in a tank with a 45° and 60° pitched blade turbine impeller operating while emptying the mixer and with an axial agitator working during axial pumping-down of water at different water levels above the impeller. Measurements made with the PIV method confirmed the change in direction of pumping liquid after the level dropped below the critical value, with an almost unchanged liquid stream flowing through the mixer. It was found that an increase in the value of the tangential velocity in the area of the impeller took place and the quantity of this increase depended on the angle of the blade pitch and the rotational frequency of the impeller. Change in this velocity component increased the mixing power.
Research on Rotating Machinery Fault Diagnosis Method Based on Energy Spectrum Matrix and Adaptive Convolutional Neural Network
Authors: Liu Yiyang , Yang Yousheng , Feng Tieying , Sun Yi , Zhang Xuejian
Published: December 2020

Traditional intelligent fault diagnosis methods focus on distinguishing different fault modes, but ignore the deterioration of fault severity. This paper proposes a new two-stage hierarchical convolutional neural network for fault diagnosis of rotating machinery bearings. The failure mode and failure severity are modeled as a hierarchical structure. First, the original vibration signal is transformed into an energy spectrum matrix containing fault-related information through wavelet packet decomposition. Secondly, in the model training method, an adaptive learning rate dynamic adjustment strategy is further proposed, which adaptively extracts robust features from the spectrum matrix for fault mode and severity diagnosis. To verify the effectiveness of the method, the bearing fault data was collected using a rotating machine test bench. On this basis, the diagnostic accuracy, convergence performance and robustness of the model under different signal-to-noise ratios and variable load environments are evaluated, and the feature learning ability of the method is verified by visual analysis. Experimental results show that this method has achieved satisfactory results in both fault pattern recognition and fault severity evaluation, and is superior to other machine learning and deep learning methods.
Optimization Studies of AC4CH Material in the Cylinder Block of a Diesel Engine Application
Authors: Park Bum Youl , Kim Youngkun , Lee Kihyung
Published: December 2020

The reduction of the weight of the engine of a vessel or an automobile can result in improved engine efficiency and lower CO2 emissions. Therefore, this study was conducted to improve the mechanical properties of the AC4CH alloy, an alternative to cast iron for engine fabrication, through the addition of Si and Mg to aluminum. The mechanical properties of the alloy were improved through refinement of the Si structure, grain refinement, and heat treatment. In addition, the applicability of a cylinder block fabricated with the modified AC4CH alloy to a diesel engine was validated through a 300 h durability test.
Investigation of Ni–Fe–Cu-Layered Double Hydroxide Catalysts in Steam Reforming of Toluene as a Model Compound of Biomass Tar
Authors: Díez David , Urueña Ana , Antolín Gregorio
Published: December 2020

This work focused on the synthesis of a catalyst based on layered double hydroxides with a molar cation concentration Ni/Cu/Fe/Mg/Al of 30/5/5/40/20 and its performance in the steam reforming of toluene as a model compound of biomass tar. Its performance at different temperatures (500, 600, 700, 800, and 900 °C) and steam/carbon molar ratios (S/C ratios) (1, 2, 4, 6, 8) was studied. The contact time used was 0.32 g h mol−1. The catalyst obtained allowed us to reach 98–99.87% gas conversion of toluene with a low carbon deposition on catalyst surface (1.4 wt %) at 800 °C and S/C = 4. In addition, conversions in the range of 600–700 °C were higher than 80% and 90%, respectively, and the type of carbon deposited on the catalyst was found to be filamentous, which did not significantly reduce the performance of the catalyst.
Microemulsion vs. Precipitation: Which Is the Best Synthesis of Nickel–Ceria Catalysts for Ethanol Steam Reforming?
Authors: Pizzolitto Cristina , Menegazzo Federica , Ghedini Elena , Martínez Arias Arturo , Cortés Corberán Vicente , Signoretto Michela
Published: December 2020

Ethanol steam reforming is one of the most promising ways to produce hydrogen from biomass, and the goal of this research is to investigate robust, selective and active catalysts for this reaction. In particular, this work is focused on the effect of the different ceria support preparation methods on the Ni active phase stabilization. Two synthetic approaches were evaluated: precipitation (with urea) and microemulsion. The effects of lanthanum doping were investigated too. All catalysts were characterized using N2-physisorption, temperature programmed reduction (TPR), XRD and SEM, to understand the influence of the synthetic approach on the morphological and structural features and their relationship with catalytic properties. Two synthesis methods gave strongly different features. Catalysts prepared by precipitation showed higher reducibility (which involves higher oxygen mobility) and a more homogeneous Ni particle size distribution. Catalytic tests (at 500 °C for 5 h using severe Gas Hourly Space Velocity conditions) revealed also different behaviors. Though the initial conversion (near complete) and H2 yield (60%, i.e., 3.6 mol H2/mol ethanol) were the same, the catalyst prepared by microemulsion was deactivated much faster. Similar trends were found for La-promoted supports. Catalyst deactivation was mainly related to coke deposition as was shown by SEM of the used samples. Higher reducibility of the catalysts prepared by the precipitation method led to a decrease in coke deposition rate by facilitating the removal of coke precursors, which made them the more stable catalysts of the reaction.
Spacetime Paths as a Whole
Authors: Nelson-Isaacs Sky
Published: December 2020

The mathematical similarities between non-relativistic wavefunction propagation in quantum mechanics and image propagation in scalar diffraction theory are used to develop a novel understanding of time and paths through spacetime as a whole. It is well known that Feynman’s original derivation of the path integral formulation of non-relativistic quantum mechanics uses time-slicing to calculate amplitudes as sums over all possible paths through space, but along a definite curve through time. Here, a 3+1D spacetime wave distribution and its 4-momentum dual are formally developed which have no external time parameter and therefore cannot change or evolve in the usual sense. Time is thus seen “from the outside”. A given 3+1D momentum representation of a system encodes complete dynamical information, describing the system’s spacetime behavior as a whole. A comparison is made to the mathematics of holograms, and properties of motion for simple systems are derived.
Working Conditions and Career Aspirations of Waste Pickers in Lagos State
Authors: Omosimua Isaac Jacob , Oluranti Olurinola Isaiah , Obindah Gershon , Busayo Aderounmu
Published: December 2020

In many cities of third world countries, managing waste represents a beehive of activities that involve human scavengers searching for reusable or recyclable items that are either consumed or sold to generate funds for personal and family upkeep, since alternative decent employment are not available for them in the formal employment sector. Many of these waste pickers are young, work without the necessary health and safety apparatus, and expose themselves to injury and various health hazards. Therefore, this study investigated the working conditions and career aspirations of waste pickers in Lagos State, Nigeria. Using the questionnaire approach, structured, semi-structured, and open-ended questions were asked, and the Statistical Package for Social Science (SPSS) was used to descriptively analyze the data collected and interpreted. The results showed that 87% of waste pickers in Lagos State have safety kits. In addition, the results showed flexibility in working hours and days since most waste pickers get to determine when and how they begin their work, i.e., 89% of the waste pickers spend 5 to 6 days a week in waste picking while 64% of them work between 10 and 14 h daily. Regarding earnings, the results showed that 68.3% of waste pickers earn between ₦2500 ($8.2) to ₦4900 ($16) daily. Finally, the results showed that despite access to safety kits, most waste pickers (54%) had experienced one form or another of hazard which has affected their career aspiration. Therefore, based on the study results we recommend that the Lagos State and the Nigerian federal government should develop a system that ensures strict compliance to established rules or guidelines that ensures the safety and health of waste pickers on the job.
Circle of Fear in Early China
Authors: Nylan Michael , Wilson Trenton
Published: December 2020

Montesquieu wrote that “China is a despotic state whose principle is fear”. And indeed, in the early modern context in China, fear and despotism, on the one hand, were opposed to ziyou 自由 (“freedom”), on the other. These constructs created a discursive space in which theorists of the nation-state felt the need to articulate the complex relations binding despotism to fear. By contrast, during the early empires in China a different set of relations was imagined, wherein salutary fear was aligned against both despotism and freedom and, crucially, with according others a proper sense of dignity. For by the arguments of remote antiquity, “submission to instruction and fear of the gods” functioned both as a vital check on despotism and as the key barrier to the unchecked and unhampered self-assertion by subjects and rulers. Yet this notion of ritual operating within a circle of fear it helped to foster has so far escaped scholarly notice, perhaps because it does not square with the ritual theories that dominate our modern discourse and perhaps because such ritual fear has been dismissed easily as remnant, primitive superstition.
Global Stock Selection with Hidden Markov Model
Authors: Nguyen Nguyet , Nguyen Dung
Published: December 2020

Hidden Markov model (HMM) is a powerful machine-learning method for data regime detection, especially time series data. In this paper, we establish a multi-step procedure for using HMM to select stocks from the global stock market. First, the five important factors of a stock are identified and scored based on its historical performances. Second, HMM is used to predict the regimes of six global economic indicators and find the time periods in the past during which these indicators have a combination of regimes that is similar to those predicted. Then, we analyze the five stock factors of the All country world index (ACWI) in the identified time periods to assign a weighted score for each stock factor and to calculate the composite score of the five factors. Finally, we make a monthly selection of 10% of the global stocks that have the highest composite scores. This strategy is shown to outperform those relying on either ACWI, any single stock factor, or the simple average of the five stock factors.
A Robotics Course during COVID-19: Lessons Learned and Best Practices for Online Teaching beyond the Pandemic
Authors: Birk Andreas , Dineva Evelina , Maurelli Francesco , Nabor Andreas
Published: December 2020

The article describes observations from the online teaching of a robotics class during the COVID-19 pandemic caused by SARS-CoV-2, also known as the coronavirus. The changes in the course structure and in the provided material lead to an unexpected increase in the grade performance of the students. The article provides a description and an analysis of the effects and their possible causes. In addition to a grade-performance analysis, further data from a university-wide and from a course-specific survey are used. The analysis of the effects and their possible causes is furthermore discussed in relation to the educational research literature. Some evidence for the general findings is provided, which are of interest for online teaching or blended learning in general, respectively, for teaching in robotics and related areas. These include some evidence for the benefits of asynchronous online teaching and for the role of social interaction, which may happen in self-organized, smaller peer groups, even without the intervention of the instructor. The findings and the extensive pointers to the literature can also provide useful guidelines for instructors of robotics courses when considering the use of online or blended teaching in the future beyond the COVID-19 pandemic.
RCSANet: A Full Convolutional Network for Extracting Inland Aquaculture Ponds from High-Spatial-Resolution Images
Authors: Zeng Zhe , Wang Di , Tan Wenxia , Yu Gongliang , You Jiacheng , Lv Botao , Wu Zhongheng
Published: December 2020

Numerous aquaculture ponds are intensively distributed around inland natural lakes and mixed with cropland, especially in areas with high population density in Asia. Information about the distribution of aquaculture ponds is essential for monitoring the impact of human activities on inland lakes. Accurate and efficient mapping of inland aquaculture ponds using high-spatial-resolution remote-sensing images is a challenging task because aquaculture ponds are mingled with other land cover types. Considering that aquaculture ponds have intertwining regular embankments and that these salient features are prominent at different scales, a Row-wise and Column-wise Self-Attention (RCSA) mechanism that adaptively exploits the identical directional dependency among pixels is proposed. Then a fully convolutional network (FCN) combined with the RCSA mechanism (RCSANet) is proposed for large-scale extraction of aquaculture ponds from high-spatial-resolution remote-sensing imagery. In addition, a fusion strategy is implemented using a water index and the RCSANet prediction to further improve extraction quality. Experiments on high-spatial-resolution images using pansharpened multispectral and 2 m panchromatic images show that the proposed methods gain at least 2–4% overall accuracy over other state-of-the-art methods regardless of regions and achieve an overall accuracy of 85% at Lake Hong region and 83% at Lake Liangzi region in aquaculture pond extraction.