bluuebunny/crossref_metadata_2025 huggingface dataset:
Infinitely Many Homoclinic Solutions for Fourth Order p-Laplacian Differential Equations
Authors: Tersian Stepan
Published: April 2020

The existence of infinitely many homoclinic solutions for the fourth-order differential equation φ p u ″ t ″ + w φ p u ′ t ′ + V ( t ) φ p u t = a ( t ) f ( t , u ( t ) ) , t ∈ R is studied in the paper. Here φ p ( t ) = t p − 2 t , p ≥ 2 , w is a constant, V and a are positive functions, f satisfies some extended growth conditions. Homoclinic solutions u are such that u ( t ) → 0 , | t | → ∞ , u ≠ 0 , known in physical models as ground states or pulses. The variational approach is applied based on multiple critical point theorem due to Liu and Wang.
Fractional Partial Differential Equations Associated with Lêvy Stable Process
Authors: Aljedhi Reem , Kılıçman Adem
Published: April 2020

In this study, we first present a time-fractional L e ^ vy diffusion equation of the exponential option pricing models of European option pricing and the risk-neutral parameter. Then, we modify a particular L e ^ vy-time fractional diffusion equation of European-style options. Further, we introduce a more general model based on the L e ^ vy-time fractional diffusion equation and review some recent findings associated with risk-neutral free European option pricing.
On Bipolar Fuzzy Gradation of Openness
Authors: Roy Subhadip , Lee Jeong-Gon , Samanta Syamal Kumar , Pal Anita , Selvachandran Ganeshsree
Published: April 2020

The concept of bipolar fuzziness is of relatively recent origin where in addition to the presence of a property, which is done in fuzzy theory, the presence of its counter-property is also taken into consideration. This seems to be much natural and realistic. In this paper, an attempt has been made to incorporate this bipolar fuzziness in topological perspective. This is done by introducing a notion of bipolar gradation of openness and to redefine the bipolar fuzzy topology. Furthermore, a notion of bipolar gradation preserving map is given. A concept of bipolar fuzzy closure operator is also introduced and its characteristic properties are studied. A decomposition theorem involving our bipolar gradation of openness and Chang type bipolar fuzzy topology is established. Finally, some categorical results of bipolar fuzzy topology (both Chang type and in our sense) are proved.
Subcutaneous Adipose Tissue in Female Volleyball Players: Is It Related with Performance Indices?
Authors: Papadopoulou Sophia D. , Zorzou Amalia , Garcia-de-Alcaraz Antonio , Rosemann Thomas , Knechtle Beat , Nikolaidis Pantelis T.
Published: April 2020

Background and objectives: The aim of the present study was to examine subcutaneous adipose tissue distribution in female volleyball players with regards to (a) variation by anatomical site, (b) differences among age groups and playing positions, and (c) physiological characteristics associated with performance. Materials and Methods: Participants were adolescent (n = 89, age 15.6 ± 0.9 years, mean ± standard deviation) and adult female volleyball players (n = 78, 24.8 ± 5.3 years), who performed a series of anthropometric and performance tests including skinfold thickness in 10 sites, Abalakov jump (AJ) and handgrip test (HG). Results: Chin had the smallest thickness, and iliac crest and abdomen the largest. The largest correlations of skinfold thickness were shown with regards to AJ ad HG. Coefficient of variations in skinfold thickness correlated with performance indices with small magnitude. Triceps and chin were the most frequent predictors of performance indices. The anatomical site of skinfold was near the active muscle groups related to performance in HG. Conclusions: In conclusion, performance indices such AJ and HG were related with thickness of specific skinfolds and with the variation of thickness by anatomical site (i.e., the less the variation, the better the performance). Considering the relevance of specific skinfolds (e.g., triceps and chin) for performance, their further use would be recommended for purposes of training monitoring, volleyball players’ selection and talent identification.
Hydrometallurgical Treatment of Waste Printed Circuit Boards: Bromine Leaching
Authors: Cui Hao , Anderson Corby
Published: April 2020

This paper demonstrates the recovery of valuable metals from shredded Waste Printed Circuit Boards (WPCBs) by bromine leaching. Effects of sodium bromide concentration, bromine concentration, leaching time and inorganic acids were investigated. The most critical factors are sodium concentration and bromine concentration. It was found that more than 95% of copper, silver, lead, gold and nickel could be dissolved simultaneously under the optimal conditions: 50 g/L solid/liquid ratio, 1.17 M NaBr, 0.77 M Br2, 2 M HCl, 400 RPM agitation speed and 23.5 °C for 10 hours. The study shows that the dissolution of gold from waste printed circuit boards in a Br2-NaBr system is controlled by film diffusion and chemical reaction.
Micro-Machining Characteristics in High-Speed Magnetic Abrasive Finishing for Fine Ceramic Bar
Authors: Song Joonhyuk , Shinmura Takeo , Mun Sang Don , Sun Minyoung
Published: April 2020

The research aims to describe the micro-machining characteristics in a high-speed magnetic abrasive finishing, which is applicable for achieving the high surface accuracy and dimensional accuracy of fine ceramic bars that are typically characterized by strong hardness and brittle susceptibility. In this paper, the high-speed magnetic abrasive finishing was applied to investigate how the finishing parameters would have effects on such output parameters as surface roughness, variation of diameters, roundness, and removed weight. The results showed that, under variants of diamond abrasives sizing between (1, 3 and 9 µm), 1 µm showed comparatively good values as for surface roughness and roundness within shortest processing time. When the optimal condition was used, the surface roughness Ra and roundness (LSC) were improved to 0.01 µm and 0.14 µm, respectively. The tendency of diameter change could be categorized into two regions—stable and unstable. The finding from the study was that the performance of ultra-precision processing linear controlling was possibly achievable for the stable region of diameter change, while linearly controlling diameters in the workpiece.
Comparing Targeted vs. Untargeted MS2 Data-Dependent Acquisition for Peak Annotation in LC–MS Metabolomics
Authors: Ten-Doménech Isabel , Martínez-Sena Teresa , Moreno-Torres Marta , Sanjuan-Herráez Juan Daniel , Castell José V. , Parra-Llorca Anna , Vento Máximo , Quintás Guillermo , Kuligowski Julia
Published: April 2020

One of the most widely used strategies for metabolite annotation in untargeted LCMS is based on the analysis of MSn spectra acquired using data-dependent acquisition (DDA), where precursor ions are sequentially selected from MS scans based on user-selected criteria. However, the number of MSn spectra that can be acquired during a chromatogram is limited and a trade-off between analytical speed, sensitivity and coverage must be ensured. In this research, we compare four different strategies for automated MS2 DDA, which can be easily implemented in the frame of standard QA/QC workflows for untargeted LC–MS. These strategies consist of (i) DDA in the MS working range; (ii) iterated DDA split into several m/z intervals; (iii) dynamic iterated DDA of (pre)selected potentially informative features; and (iv) dynamic iterated DDA of (pre)annotated metabolic features using a reference database. Their performance was assessed using the analysis of human milk samples as model example by comparing the percentage of LC–MS features selected as the precursor ion for MS2, the number, and class of annotated features, the speed and confidence of feature annotation, and the number of LC runs required.
The ABRF Metabolomics Research Group 2016 Exploratory Study: Investigation of Data Analysis Methods for Untargeted Metabolomics
Authors: Turck Christoph W. , Mak Tytus D , Goudarzi Maryam , Salek Reza M , Cheema Amrita K
Published: April 2020

Lack of standardized applications of bioinformatics and statistical approaches for pre- and postprocessing of global metabolomic profiling data sets collected using high-resolution mass spectrometry platforms remains an inadequately addressed issue in the field. Several publications now recognize that data analysis outcome variability is caused by different data treatment approaches. Yet, there is a lack of interlaboratory reproducibility studies that have looked at the contribution of data analysis techniques toward variability/overlap of results. The goal of our study was to identify the contribution of data pre- and postprocessing methods on metabolomics analysis results. We performed urinary metabolomics from samples obtained from mice exposed to 5 Gray of external beam gamma rays and those exposed to sham irradiation (control group). The data files were made available to study participants for comparative analysis using commonly used bioinformatics and/or biostatistics approaches in their laboratories. The participants were asked to report back the top 50 metabolites/features contributing significantly to the group differences. Herein we describe the outcome of this study which suggests that data preprocessing is critical in defining the outcome of untargeted metabolomic studies.
“Notame”: Workflow for Non-Targeted LC–MS Metabolic Profiling
Authors: Klåvus Anton , Kokla Marietta , Noerman Stefania , Koistinen Ville M. , Tuomainen Marjo , Zarei Iman , Meuronen Topi , Häkkinen Merja R. , Rummukainen Soile , Farizah Babu Ambrin , Sallinen Taisa , Kärkkäinen Olli , Paananen Jussi , Broadhurst David , Brunius Carl , Hanhineva Kati
Published: April 2020

Metabolomics analysis generates vast arrays of data, necessitating comprehensive workflows involving expertise in analytics, biochemistry and bioinformatics in order to provide coherent and high-quality data that enable discovery of robust and biologically significant metabolic findings. In this protocol article, we introduce notame, an analytical workflow for non-targeted metabolic profiling approaches, utilizing liquid chromatography–mass spectrometry analysis. We provide an overview of lab protocols and statistical methods that we commonly practice for the analysis of nutritional metabolomics data. The paper is divided into three main sections: the first and second sections introducing the background and the study designs available for metabolomics research and the third section describing in detail the steps of the main methods and protocols used to produce, preprocess and statistically analyze metabolomics data and, finally, to identify and interpret the compounds that have emerged as interesting.
Contrasting Patterns of the Bacterial Communities in Melting Ponds and Periglacial Rivers of the Zhuxi glacier in the Tibet Plateau
Authors: Hu Yang , Yao Xin , Wu Yuanyuan , Han Wei , Zhou Yongqiang , Tang Xiangming , Shao Keqiang , Gao Guang
Published: April 2020

Since the early 21st century, global climate change has been inducing rapid glacier retreat at an unprecedented rate. In this context, the melt ponds impart increasing unique footprints on the periglacial rivers due to their hydrodynamic connection. Given that bacterial communities control numerous ecosystem processes in the glacial ecosystem, exploring the fate of bacterial communities from melt ponds to periglacial rivers yields key knowledge of the biodiversity and biogeochemistry of glacial ecosystems. Here, we analyzed the bacterial community structure, diversity, and co-occurrence network to reveal the community organization in the Zhuxi glacier in the Tibet Plateau. The results showed that the bacterial communities in melt ponds were significantly lower in alpha-diversity but were significantly higher in beta-diversity than those in periglacial rivers. The rare sub-communities significantly contributed to the stability of the bacterial communities in both habitats. The co-occurrence network inferred that the mutually beneficial relationships predominated in the two networks. Nevertheless, the lower ratio of positive to negative edges in melt ponds than periglacial rivers implicated fiercer competition in the former habitat. Based on the significantly higher value of degree, betweenness, and modules, as well as shorter average path length in melt ponds, we speculated that their bacterial communities are less resilient than those of periglacial rivers.
Porous Carbon Materials Obtained by the Hydrothermal Carbonization of Orange Juice
Authors: Veltri Francesco , Alessandro Francesca , Scarcello Andrea , Beneduci Amerigo , Arias Polanco Melvin , Cid Perez Denia , Vacacela Gomez Cristian , Tavolaro Adalgisa , Giordano Girolamo , Caputi Lorenzo S.
Published: April 2020

Porous carbon materials are currently subjected to strong research efforts mainly due to their excellent performances in energy storage devices. A sustainable process to obtain them is hydrothermal carbonization (HTC), in which the decomposition of biomass precursors generates solid products called hydrochars, together with liquid and gaseous products. Hydrochars have a high C content and are rich with oxygen-containing functional groups, which is important for subsequent activation. Orange pomace and orange peels are considered wastes and then have been investigated as possible feedstocks for hydrochars production. On the contrary, orange juice was treated by HTC only to obtain carbon quantum dots. In the present study, pure orange juice was hydrothermally carbonized and the resulting hydrochar was filtered and washed, and graphitized/activated by KOH in nitrogen atmosphere at 800 °C. The resulting material was studied by transmission and scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen sorption isotherms. We found porous microspheres with some degree of graphitization and high nitrogen content, a specific surface of 1725 m2/g, and a pore size distribution that make them good candidates for supercapacitor electrodes.
Modified Nanoparticles as Potential Agents in Bone Diseases: Cancer and Implant-Related Complications
Authors: Steckiewicz Karol P. , Inkielewicz-Stepniak Iwona
Published: April 2020

Materials sized 1–100 nm are the nanotechnology’s field of interest. Because of the unique properties such as the ability to penetrate biological barriers and a high surface to volume ratio, nanoparticles (NPs) are a powerful tool to be used in medicine and industry. This review discusses the role of nanotechnology in bone-related issues: osteosarcoma (bone cancer), the biocompatibility of the implants and implant-related infections. In cancer therapy, NPs can be used as (I) cytotoxic agents, (II) drug delivery platforms and (III) in thermotherapy. In implant-related issues, NPs can be used as (I) antimicrobial agents and (II) adjuvants to increase the biocompatibility of implant surface. Properties of NPs depend on (I) the type of NPs, (II) their size, (III) shape, (IV) concentration, (V) incubation time, (VI) functionalization and (VII) capping agent type.
High-Yield Production of Few-Layer Graphene via New-fashioned Strategy Combining Resonance Ball Milling and Hydrothermal Exfoliation
Authors: Yang Qingfeng , Zhou Ming , Yang Mingyang , Zhang Zhixun , Yu Jianwen , Zhang Yibo , Cheng Wenjun , Li Xuyin
Published: April 2020

Graphene shows great potential applications in functional coating, electrodes, and ultrasensitive sensors, but high-yield and scalable preparation of few-layer graphene (FLG) by mechanical exfoliation method is still a formidable challenge. In this work, a novel two-step method for high-yield preparation of FLG is developed by combining resonance ball milling and hydrothermal treatment. During the resonance ball milling process, the utilization of magnetic Fe3O4 nanoparticles as a new “particle wedge” is beneficial to facilitate fragment and delamination of graphitic layers. In addition, further hydrothermal treatment can enhance ball milling product (BMP) exfoliation because of the shear force driven by the Brownian motion of various molecules at high temperature and high pressure. As expected, the two-step method can have high exfoliation efficiency up to 92% (≤10 layers). Moreover, the FLG nanosheet ink can easily achieve the formation of FLG coatings on the surface of various substrates, resulting in good electrical conductivity, which possesses potential applications in various fields including functional coating, energy storages, and electrochemical sensors, etc. Our work provides a new-fashioned strategy for mechanical large-scale production of graphene.
Dynamic Expression of Long Non-Coding RNAs Throughout Parasite Sexual and Neural Maturation in Schistosoma Japonicum
Authors: Maciel Lucas , Morales-Vicente David , Verjovski-Almeida Sergio
Published: April 2020

Schistosoma japonicum is a flatworm that causes schistosomiasis, a neglected tropical disease. S. japonicum RNA-Seq analyses has been previously reported in the literature on females and males obtained during sexual maturation from 14 to 28 days post-infection in mouse, resulting in the identification of protein-coding genes and pathways, whose expression levels were related to sexual development. However, this work did not include an analysis of long non-coding RNAs (lncRNAs). Here, we applied a pipeline to identify and annotate lncRNAs in 66 S. japonicum RNA-Seq publicly available libraries, from different life-cycle stages. We also performed co-expression analyses to find stage-specific lncRNAs possibly related to sexual maturation. We identified 12,291 S. japonicum expressed lncRNAs. Sequence similarity search and synteny conservation indicated that some 14% of S. japonicum intergenic lncRNAs have synteny conservation with S. mansoni intergenic lncRNAs. Co-expression analyses showed that lncRNAs and protein-coding genes in S. japonicum males and females have a dynamic co-expression throughout sexual maturation, showing differential expression between the sexes; the protein-coding genes were related to the nervous system development, lipid and drug metabolism, and overall parasite survival. Co-expression pattern suggests that lncRNAs possibly regulate these processes or are regulated by the same activation program as that of protein-coding genes.
Effect of Two Meal Replacement strategies on Cardiovascular Risk Parameters in Advanced Age Patients with Obesity and Osteoarthritis
Authors: López-Gómez Juan José , Izaola-Jauregui Olatz , Primo-Martín David , Torres-Torres Beatriz , Gómez-Hoyos Emilia , Ortolá-Buigues Ana , Martín-Ferrero Miguel A. , De Luis-Román Daniel A.
Published: April 2020

Background and aims: Meal replacement diets consist of replacing one or more meals with an artificial nutritional supplement. The objective of this study was to compare the effect of one against two meal replacement strategies on body composition and cardiovascular risk parameters in patients with obesity. Methods: A randomized clinical trial was designed with a modified hypocaloric diet with an artificial nutritional preparation replacing one or two meals for three months in patients with obesity and osteoarthritis pending orthopedic surgery. An anthropometric evaluation and a measurement of the body composition were done with bioelectrical impedance measurement at the beginning and at three months. Results: A total of 112 patients were recruited. Fifty-two patients (46.4%) were randomized to one replacement and 60 patients (53.6%) to two meal replacements. Eighty-one patients (72.3%) were women, and the average age was 61 (11.03) years. The percentage of weight loss at three months was 8.27 (4.79)% (one meal replacement: 7.98 (5.97)%; two meal replacements: 8.50 (3.48)%; p = 0.56). A decrease in fat mass measured by the fat mass index (FMI) was detected (one meal replacement: −2.15 (1.45) kg/m2 vs. two meal replacements: −2.78 (2.55) kg/m2; p > 0.05), and a relative increase in fat-free mass was observed (one meal replacement: +3.57 (4.61)% vs. two meal replacements: +2.14 (4.45)%; p > 0.05). A decrease in HOMA-IR, systolic blood pressure (SBP), and total cholesterol was observed in both groups without differences between them. Conclusions: The substitution strategies of one or two meal replacements were effective in weight loss and fat mass decrease without differences between the two groups. An improvement in lipid parameters, glycemic control, and systolic blood pressure was observed without differences between strategies.
Chronic Stress Contributes to Osteosarcopenic Adiposity via Inflammation and Immune Modulation: The Case for More Precise Nutritional Investigation
Authors: Ilich Jasminka Z. , Gilman Jennifer C. , Cvijetic Selma , Boschiero Dario
Published: April 2020

Chronic stress and low-grade chronic inflammation (LGCI) are key underlying factors for many diseases, including bone and body composition impairments. Objectives of this narrative review were to examine the mechanisms by which chronic stress and LGCI may influence osteosarcopenic adiposity (OSA) syndrome, originally named as ostoesarcopenic obesity (OSO). We also examined the crucial nutrients presumed to be affected by or cause of stress and inflammation and compared/contrasted them to those of our prehistoric ancestors. The evidence shows that stress (particularly chronic) and its related inflammatory processes, contribute to osteoporosis, sarcopenia, and adiposity ultimately leading to OSA as a final and most deranged state of body composition, commencing at the mesenchymal cell lineage disturbance. The foods/nutrients consumed by modern humans, as well as their altered lifestyle, also contribute to stress, LGCI and subsequently to OSA. The processes can also go in opposite direction when stress and inflammation impact nutritional status, particularly some micronutrients’ levels. While nutritional management of body composition and LGCI have been studied, the nutrients (and their quantities) most affected by stressors and those which may act toward the alleviation of stressful state, ultimately leading to better body composition outcomes, need to be elucidated.
Optimization of Thiolated Chitosan Nanoparticles for the Enhancement of in Vivo Hypoglycemic Efficacy of Sitagliptin in Streptozotocin-Induced Diabetic Rats
Authors: Prabahar Kousalya , Udhumansha Ubaidulla , Qushawy Mona
Published: April 2020

Sitagliptin (SGN) is an antidiabetic drug used for treatment of diabetes mellitus type II. The objectives of this study were to formulate SGN in form of thiolated chitosan (TC) nanoparticles to enhance the mucoadhesion properties of SGN to the gastrointestinal tract, prolong drug release, decrease side effects, and enhance patient compliance. Seventeen batches of SGN-TC nanoparticles were designed by Box-Behnken design and prepared using the ionic gelation method using tripolyphosphate (TPP) as crosslinking agent. The prepared formulations were evaluated for particle size, entrapment efficiency %, and in vitro drug release. Based on the results of optimization, three formulations (F1–F3) were prepared with different drug polymer ratios (1:1, 1:2, and 1:3). The mucoadhesion study and in vivo hypoglycemic activity of three formulations were evaluated in comparison to free SGN in streptozotocin (STZ)-induced diabetic rats. The seventeen SGN-TC nanoparticles showed small particle sizes, high entrapment efficiency, and prolonged drug release. The concentration of TC polymers had highest effect on these responses. The percentage of SGN–TC nanoparticles adhered to tissue was increased and the release was prolonged as the concentration of TC polymer increased (F3 > F2 > F1). The hypoglycemic effect of SGN-TC nanoparticles was significantly higher than resulted by free SGN. It was concluded that TC nanoparticles had the ability to enhance the mucoadhesion properties of SGN and prolong the drug release. SGN-TC nanoparticles significantly reduced plasma glucose levels compared to free SGN in STZ-induced diabetic rats.
The Segregated Intestinal Flow Model (SFM) for Drug Absorption and Drug Metabolism: Implications on Intestinal and Liver Metabolism and Drug–Drug Interactions
Authors: Pang K. Sandy , Peng H. Benson , Noh Keumhan
Published: April 2020

The properties of the segregated flow model (SFM), which considers split intestinal flow patterns perfusing an active enterocyte region that houses enzymes and transporters (<20% of the total intestinal blood flow) and an inactive serosal region (>80%), were compared to those of the traditional model (TM), wherein 100% of the flow perfuses the non-segregated intestine tissue. The appropriateness of the SFM model is important in terms of drug absorption and intestinal and liver drug metabolism. Model behaviors were examined with respect to intestinally (M1) versus hepatically (M2) formed metabolites and the availabilities in the intestine (FI) and liver (FH) and the route of drug administration. The %contribution of the intestine to total first-pass metabolism bears a reciprocal relation to that for the liver, since the intestine, a gateway tissue, regulates the flow of substrate to the liver. The SFM predicts the highest and lowest M1 formed with oral (po) and intravenous (iv) dosing, respectively, whereas the extent of M1 formation is similar for the drug administered po or iv according to the TM, and these values sit intermediate those of the SFM. The SFM is significant, as this drug metabolism model explains route-dependent intestinal metabolism, describing a higher extent of intestinal metabolism with po versus the much reduced or absence of intestinal metabolism with iv dosing. A similar pattern exists for drug–drug interactions (DDIs). The inhibitor or inducer exerts its greatest effect on victim drugs when both inhibitor/inducer and drug are given po. With po dosing, more drug or inhibitor/inducer is brought into the intestine for DDIs. The bypass of flow and drug to the enterocyte region of the intestine after intravenous administration adds complications to in vitro–in vivo extrapolations (IVIVE).
In Vitro Propagation, Phytochemical and Neuropharmacological Profiles of Bacopa monnieri (L.) Wettst.: A Review
Authors: Saha Partha Sarathi , Sarkar Sayantika , Jeyasri Rajendran , Muthuramalingam Pandiyan , Ramesh Manikandan , Jha Sumita
Published: April 2020

Bacopa monnieri has been used as a reputed drug in the Indian traditional ayurvedic system for centuries. This medicinal herb with important phytopharmaceuticals has been popularly known as “Brahmi”. In recent years, B. monnieri has been extensively studied for its bioactive constituents, constituents responsible for memory enhancing effect, and also its diverse other useful effects. It possesses many pharmacological activities such as antioxidant, gastrointestinal, endocrine, antimicrobial, anti-inflammatory etc. The plant has been also used for the treatment of neurological and neuropsychiatric diseases. Due to its multipurpose therapeutic potential, micropropagation using axillary meristems and de novo organogenesis has been extensively studied in the species and is being reviewed. High frequency direct shoot organogenesis can be induced in excised leaf and internode explants in the absence of exogenous phytohormones and the rate of induction is enhanced in the presence of exogenous cytokinins, supplements, growth regulators, etc. Using explants from tissue culture raised plants, direct shoot regeneration leading to production of more than 100 rooted plants/explant within 8–12 weeks period with 85%–100% survival in the field after acclimatization can be expected following optimized protocols. Bioreactor based micropropagation was found to increase the multiplication rate of shoot cultures for the commercial propagation of B. monnieri plants. The maximum content of bacosides has been recorded in shoot biomass using an airlift bioreactor system. Further studies for the biosynthesis of bacosides and other secondary metabolites need to be conducted in the species utilizing untransformed shoot cultures in bioreactors.
The Treasure Vault Can be Opened: Large-Scale Genome Skimming Works Well Using Herbarium and Silica Gel Dried Material
Authors: Alsos Inger Greve , Lavergne Sebastien , Merkel Marie Kristine Føreid , Boleda Marti , Lammers Youri , Alberti Adriana , Pouchon Charles , Denoeud France , Pitelkova Iva , Pușcaș Mihai , Roquet Cristina , Hurdu Bogdan-Iuliu , Thuiller Wilfried , Zimmermann Niklaus E. , Hollingsworth Peter M. , Coissac Eric
Published: April 2020

Genome skimming has the potential for generating large data sets for DNA barcoding and wider biodiversity genomic studies, particularly via the assembly and annotation of full chloroplast (cpDNA) and nuclear ribosomal DNA (nrDNA) sequences. We compare the success of genome skims of 2051 herbarium specimens from Norway/Polar regions with 4604 freshly collected, silica gel dried specimens mainly from the European Alps and the Carpathians. Overall, we were able to assemble the full chloroplast genome for 67% of the samples and the full nrDNA cluster for 86%. Average insert length, cover and full cpDNA and rDNA assembly were considerably higher for silica gel dried than herbarium-preserved material. However, complete plastid genomes were still assembled for 54% of herbarium samples compared to 70% of silica dried samples. Moreover, there was comparable recovery of coding genes from both tissue sources (121 for silica gel dried and 118 for herbarium material) and only minor differences in assembly success of standard barcodes between silica dried (89% ITS2, 96% matK and rbcL) and herbarium material (87% ITS2, 98% matK and rbcL). The success rate was > 90% for all three markers in 1034 of 1036 genera in 160 families, and only Boraginaceae worked poorly, with 7 genera failing. Our study shows that large-scale genome skims are feasible and work well across most of the land plant families and genera we tested, independently of material type. It is therefore an efficient method for increasing the availability of plant biodiversity genomic data to support a multitude of downstream applications.
Bioactive Compounds from Leaves and Twigs of Guayule Grown in a Mediterranean Environment
Authors: Piluzza Giovanna , Campesi Giuseppe , Molinu Maria Giovanna , Re Giovanni Antonio , Sulas Leonardo
Published: April 2020

Guayule (Parthenium argentatum) is one of the most promising alternatives to produce natural rubber. As the guayule leaves represent a waste byproduct in the rubber extraction process, their exploitation might contribute to the valorization of the whole plant biomass. The specific aim of our study was to determine the antioxidant capacity and the content of phenolic compounds in leaves and twigs of different guayule lines cultivated in a Mediterranean environment. The antioxidant capacity and the contents of phenolic were affected significantly by guayule accession and harvest time. Overall means in twigs represented about 60% of the corresponding leaf values for antioxidant capacity as DPPH (1,1-diphenyl-2-picrylhydrazyl) and not tannic phenolic and about 55% as ABTS (2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt), total phenolic, tannic phenolic and total flavonoid contents. Five individual phenolic compounds were identified in methanolic extracts of leaves. Neochlorogenic acid (62.5–174.8 mg g−1 DW) and chlorogenic acid (28.6–41.1 mg g−1 DW) were the most abundant phenolic acids. In addition to the compounds quantified in leaves, cynarin was identified only in twigs and for the first time in guayule biomass. Our results indicate that guayule leaves and twigs represent a rich source of antioxidants for potential applications in fodder, nutraceutical and pharmacological sectors.
Priming of Defense Systems and Upregulation of MYC2 and JAZ1 Genes after Botrytis cinerea Inoculation in Methyl Jasmonate-Treated Strawberry Fruits
Authors: Valenzuela-Riffo Felipe , Zúñiga Paz E. , Morales-Quintana Luis , Lolas Mauricio , Cáceres Marcela , Figueroa Carlos R.
Published: April 2020

Several attempts have been made to study the effects of methyl jasmonate (MeJA) on plants in the past years. However, the comparative effects of the number and phenological time of MeJA applications on the activation of defense systems is currently unknown in strawberries. In the present research, we performed three field treatments during strawberry (Fragaria × ananassa ‘Camarosa’) fruit development and ripening which consisted of differential MeJA applications at flowering (M3), and the large green (M2 and M3) and red ripe (M1, M2, and M3) fruit stages. We also checked changes in gene expression related to plant defense against Botrytis cinerea inoculation post-harvest. In M3 treatment, we observed an upregulation of the anthocyanin and lignin contents and the defense-related genes, encoding for chitinases, β-1,3-glucanases and polygalacturonase-inhibiting proteins, after harvest (0 hpi), along with the jasmonate signaling-related genes FaMYC2 and FaJAZ1 at 48 h after B. cinerea inoculation (48 hpi) during postharvest storage. Although we did not find differences in gray mold incidence between the MeJA treatments and control, these results suggest that preharvest MeJA treatment from the flowering stage onwards (M3) primes defense responses mediated by the upregulation of different defense-related genes and retains the upregulation of MYC2 and JAZ1 at 48 hpi.
Antimicrobial Polymer-Based Materials for Food Packaging Applications
Authors: Díez-Pascual Ana María
Published: April 2020

Antimicrobial packaging has recently attracted a great deal of interest from the food industry due to the boost in consumer demand for minimally-processed, preservative-free products [...]
Star-Shaped Crosslinker for Multifunctional Shape Memory Polyurethane
Authors: Song Xiuhuan , Chi Hong , Li Zibiao , Li Tianduo , Wang FuKe
Published: April 2020

Star-shaped cyclophosphazene (ACP) was employed as covalent crosslinker to form a rigid segment in polyurethanes network, to enhance the mechanical performance and to add extra flame retardant property. The effects of different ACP contents on the shape memory ability and fire resistance performance of polyurethane (PU) were studied. Tensile tests suggested high flexibility of the PUs with the maximum elongation-at-break of 161.59%. Dynamic mechanical analysis (DMA) indicated good shape recovery ratio of 72.58% after more than three repeated cycles. Under thermal treatment, the temporary shape could recover to its original state in 10 s. The peak heat release rate (pHRR), total heat released (THR) and temperature at pHRR (Tp) of flame-retardant shape memory polyurethane (FSPU) by micro-combustion calorimeter (MCC) was as low as 183.2 W/g, 21.4 KJ/g, 330.8 °C respectively, suggesting good inherent fire-resistant performance. As amine-containing crosslinkers are one of the most common building units in thermosetting polymers, we anticipate that our finding will have significant benefits beyond shape memory and fire-resistance.
Chitosan/PAMAM/Hydroxyapatite Engineered Drug Release Hydrogels with Tunable Rheological Properties
Authors: Pistone Alessandro , Iannazzo Daniela , Celesti Consuelo , Scolaro Cristina , Giofré Salvatore V. , Romeo Roberto , Visco Annamaria
Published: April 2020

In this paper, a new formulation of biodegradable and bioresorbable chitosan-based hydrogel for controlled drug release was investigated. A chitosan–dendrimer–hydroxyapatite hydrogel, obtained by covalently grafting chitosan powder with an hyperbranched PAMAM dendrimer followed by in-situ precipitation of hydroxyapatite and gelification, was synthesized and characterized by FTIR, NMR, TGA, XRD and rheological studies. The hydrogels have been also doped with an anti-inflammatory drug (ketoprofen) in order to investigate their drug release properties. Chemical and chemical-physical characterizations confirmed the successful covalent functionalization of chitosan with PAMAM and the synthesis of nanostructured hydroxyapatite. The developed hydrogel made it possible to obtain an innovative system with tunable rheological and drug-releasing properties relative to the well-known formulation containing chitosan and hydroxyapatite powder. The developed hydrogel showed different rheological and drug-releasing properties of chitosan matrix mixed with hydroxyapatite as a function of dendrimer molecular weight; therefore, the chitosan–dendrimer–hydroxyapatite hydrogel can couple the well-known osteoconductive properties of hydroxyapatite with the drug-release behavior and good processability of chitosan–dendrimer hydrogels, opening new approaches in the field of tissue engineering based on biopolymeric scaffolds.
A Tough and Mildew-Proof Soybean-Based Adhesive Inspired by Mussel and Algae
Authors: Bai Yue , Liu Xiaorong , Shi Sheldon Q. , Li Jianzhang
Published: April 2020

Despite the recent advances in protein-based adhesives, achieving strong adhesion and mold resistance in wet environment is challenging. Herein, a facile fabrication technology of preparing tough bio-adhesive by incorporating soybean meal and blood meal is presented. Inspired by the marine mussel byssi and brown algae, metal coordination was introduced into a loosely bound protein system to construct multiple chemical cross-linking networks. Mixed alkali-modified blood meal (mBM) was mixed with soybean meal, then 1,6-hexane dioldiglycidyl ether (HDE) and zinc ion were introduced to fabricate soybean meal and blood meal-based adhesives. The attained adhesives exhibited good thermal stability, water resistance (the wet shear strength is 1.1 MPa), and mold resistance, with appropriate solid content (34.3%) and relatively low moisture uptake (11.9%). These outstanding performances would be attributed to the reaction of 1,6-hexane dioldiglycidyl ether with protein to form a preliminary cross-linking network; subsequently, the coordination of zinc ions with amino or carboxyl strengthened and toughened the adhesive. Finally, the calcium ions gelled the adhesives, providing cohesion force and making the network structure more compact. This study realized the value-added utilization of protein co-products and developed a new eco-friendly bio-based adhesive.
Waterborne Intumescent Coatings Containing Industrial and Bio-Fillers for Fire Protection of Timber Materials
Authors: Aqlibous Abderrahman , Tretsiakova-McNally Svetlana , Fateh Talal
Published: April 2020

Flammability and combustion of softwood treated with intumescent coatings were studied in the present work. The formulations applied onto wood surfaces contained different ratios of industrial fillers, titanium dioxide TiO2 and aluminium trihydroxide Al(OH)3, and/or bio-fillers, eggshell and rice husk ash. Combustion behaviours of unprotected and protected wood samples have been examined with the aid of cone calorimetry performed under the varied levels of thermal flux ranging from 30 to 50 kW/m². The char residues obtained after the completion of cone calorimetry test at 40 kW/m² were analysed by the Raman spectroscopy. The fire protective properties of the studied coatings were strongly influenced by the nature of the fillers as well as by the intensity of thermal irradiance. The incorporation of bio-based fillers into the water-based intumescent formulations significantly improved fire resistance of wood substrates. For example, at 30 kW/m², the Effective Heat of Combustion was reduced by more than 40%, whilst the average Peak to Heat Release Rate had dropped from 193.2 to 150.3 kW/m² for the wood sample protected with the formulation incorporating two industrial and two bio-fillers. Moreover, an application of the studied coatings resulted in a notable reduction of the back surface temperature of the wood specimens.
Thermal Welding by the Third Phase Between Polymers: A Review for Ultrasonic Weld Technology Developments
Authors: Qiu Jianhui , Zhang Guohong , Sakai Eiichi , Liu Wendi , Zang Limin
Published: April 2020

Ultrasonic welding (USW) is a promising method for the welds between dissimilar materials. Ultrasonic thermal welding by the third phase (TWTP) method was proposed in combination with the formation of a third phase, which was confirmed as an effective technology for polymer welding between the two dissimilar materials compared with the traditional USW. This review focused on the advances of applying the ultrasonic TWTP for thermoplastic materials. The research development on the ultrasonic TWTP of polycarbonate (PC) and polymethyl methacrylate (PMMA), polylactic acid (PLA) and polyformaldehyde (POM), and PLA and PMMA are summarized according to the preparation of the third phase, welded strength, morphologies of rupture surfaces, thermal stability, and others. The review aimed at providing guidance for using ultrasonic TWTP in polymers and a basic understanding of the welding mechanism, i.e., interdiffusion and molecular motion mechanisms between the phases.
Erratum: Piezoelastic PVDF/TPU Nanofibrous Composite Membrane: Fabrication and Characterization. Polymers 2019, 11(10), 1634
Authors: Elnabawy Eman , Hassanin Ahmed H. , Shehata Nader , Popelka Anton , Nair Remya , Yousef Saifallah , Kandas Ishac
Published: April 2020

The authors wish to make a change to the published paper [...]
Controlling Molecule Aggregation and Electronic Spatial Coherence in the H-Aggregate and J-Aggregate Regime at Room Temperature
Authors: Dou Fei , Li Jiawei , Men Huijie , Zhang Xinping
Published: April 2020

Controlling molecule aggregation in polymer films is one of the key factors in understanding the links between properties and structures in organic semiconductors. Here, we used poly(3-hexylthiophene-2,5-diyl) (P3HT) as the model system. By doping the insulating polar additive poly (ethylene oxide) (PEO) into P3HT film and controlling the processing methods, we achieved the side-to-side H-aggregate and head-to-tail J-aggregate of P3HT molecules with different extents at room temperature. We have demonstrated that the solvent solidification rate plays an important role in the controlling of molecule aggregation, which finally influenced the solid-state phase separation in the film. Furthermore, based on a series of spectroscopy investigations, we quantified the electronic spatial coherence in different aggregations combined with the modified Franck–Condon model. Subsequently, we established the relationship between the processing method, the molecule aggregation, and the electronic spatial coherence.
Creation of a PDMS Polymer Brush on SiO2-Based Nanoparticles by Surface-Initiated Ring-Opening Polymerization
Authors: Koch Karin , Geller Sven , Acar Kubilay , Bach Patricia , Tsarenko Ekaterina , Schmidt Annette
Published: April 2020

The incorporation of nanoparticles into soft matrices opens a broad spectrum of novel property combinations. However, one of the major challenges for these systems remains the compatibilization of particles with the surrounding matrix by proper surface functionalization. For silicon-based systems or liquid crystalline phases, polydimethylsiloxane (PDMS) brushes at the surface of particles increase the stability against particle agglomeration in such systems. Here, we report a novel approach for the functionalization of particles with a polysiloxane brush by surface-initiated ring-opening polymerization of a cyclosiloxane. For this purpose, surface hydroxy groups of silica and silica-coated hematite particles are used as initiators in combination with phosphazene bases as catalysts. The ring–chain equilibrium of a model-based solution polymerization is investigated in detail to find the appropriate reaction parameters. The corresponding molar masses are determined and compared by 1H-NMR and SEC measurements to confirm the underlying mechanism. In the resulting hybrid nanostructures, a covalently bound PDMS fraction is achieved up to 47 mass %.
3D Hierarchical, Nanostructured Chitosan/PLA/HA Scaffolds Doped with TiO2/Au/Pt NPs with Tunable Properties for Guided Bone Tissue Engineering
Authors: Radwan-Pragłowska Julia , Janus Łukasz , Piątkowski Marek , Bogdał Dariusz , Matysek Dalibor
Published: April 2020

Bone tissue is the second tissue to be replaced. Annually, over four million surgical treatments are performed. Tissue engineering constitutes an alternative to autologous grafts. Its application requires three-dimensional scaffolds, which mimic human body environment. Bone tissue has a highly organized structure and contains mostly inorganic components. The scaffolds of the latest generation should not only be biocompatible but also promote osteoconduction. Poly (lactic acid) nanofibers are commonly used for this purpose; however, they lack bioactivity and do not provide good cell adhesion. Chitosan is a commonly used biopolymer which positively affects osteoblasts’ behavior. The aim of this article was to prepare novel hybrid 3D scaffolds containing nanohydroxyapatite capable of cell-response stimulation. The matrixes were successfully obtained by PLA electrospinning and microwave-assisted chitosan crosslinking, followed by doping with three types of metallic nanoparticles (Au, Pt, and TiO2). The products and semi-components were characterized over their physicochemical properties, such as chemical structure, crystallinity, and swelling degree. Nanoparticles’ and ready biomaterials’ morphologies were investigated by SEM and TEM methods. Finally, the scaffolds were studied over bioactivity on MG-63 and effect on current-stimulated biomineralization. Obtained results confirmed preparation of tunable biomimicking matrixes which may be used as a promising tool for bone-tissue engineering.
Special Issue on “Computational Methods for Polymers”
Authors: Soroush Masoud
Published: April 2020

Polymers play a key role in our daily lives [...]
Low-Molecular-Weight Phenols Recovery by Eco-Friendly Extraction from Quercus Spp. Wastes: An Analytical and Biomass-Sustainability Evaluation
Authors: Ianni Federica , Segoloni Enrico , Blasi Francesca , Di Maria Francesco
Published: April 2020

In this work, chemical–physical protocols aimed at the implementation of eco-friendly and biomass-sustainable recovery processes of useful compounds from forestry and/or wood industry wastes were evaluated. Four species of interest in industrial and environmental fields (Quercus cerris, Quercus ilex, and Robinia pseudoacacia from Central Italy, Quercus petraea from France) were submitted to neutral extraction and analyzed by gaschromatography, with mass spectrometry identification of low-molecular-weight phenols. Moreover, Quercus petraea heartwood samples were submitted to three extraction/hydrolysis protocols in an alkaline environment, and the byproducts from the lignin degradation were identified and evaluated. The recovery of bioactive phenols from forestry wastes by applying eco-friendly extractive protocols may reveal a precious strategy for rethinking the management of such wastes, in line with the fundamentals of “circular economy”.