bluuebunny/crossref_metadata_2025 huggingface dataset:
Joint Impacts of Drought and Habitat Fragmentation on Native Bee Assemblages in a California Biodiversity Hotspot
Authors: Hung Keng-Lou James , Sandoval Sara S. , Ascher John S. , Holway David A.
Published: February 2021

Global climate change is causing more frequent and severe droughts, which could have serious repercussions for the maintenance of biodiversity. Here, we compare native bee assemblages collected via bowl traps before and after a severe drought event in 2014 in San Diego, California, and examine the relative magnitude of impacts from drought in fragmented habitat patches versus unfragmented natural reserves. Bee richness and diversity were higher in assemblages surveyed before the drought compared to those surveyed after the drought. However, bees belonging to the Lasioglossum subgenus Dialictus increased in abundance after the drought, driving increased representation by small-bodied, primitively eusocial, and generalist bees in post-drought assemblages. Conversely, among non-Dialictus bees, post-drought years were associated with decreased abundance and reduced representation by eusocial species. Drought effects were consistently greater in reserves, which supported more bee species, than in fragments, suggesting that fragmentation either had redundant impacts with drought, or ameliorated effects of drought by enhancing bees’ access to floral resources in irrigated urban environments. Shifts in assemblage composition associated with drought were three times greater compared to those associated with habitat fragmentation, highlighting the importance of understanding the impacts of large-scale climatic events relative to those associated with land use change.
Special Issue: Ecology of Sex and Sexual Communication in Insects
Authors: Burdfield-Steel Emily R. , Harari Ally Rachel
Published: February 2021

Sexual reproduction places constraints on both the place and time in which individuals can reproduce, as the sperm and ova need to meet in a certain location within a specific time frame for successful reproduction [...]
Effect of Ni on the Suppression of Sn Whisker Formation in Sn-0.7Cu Solder Joint
Authors: Hashim Aimi Noorliyana , Salleh Mohd Arif Anuar Mohd , Sandu Andrei Victor , Ramli Muhammad Mahyiddin , Yee Khor Chu , Mohd Mokhtar Noor Zaimah , Chaiprapa Jitrin
Published: February 2021

The evolution of internal compressive stress from the intermetallic compound (IMC) Cu6Sn5 growth is commonly acknowledged as the key inducement initiating the nucleation and growth of tin (Sn) whisker. This study investigates the effect of Sn-0.7Cu-0.05Ni on the nucleation and growth of Sn whisker under continuous mechanical stress induced. The Sn-0.7Cu-0.05Ni solder joint has a noticeable effect of suppression by diminishing the susceptibility of nucleation and growth of Sn whisker. By using a synchrotron micro X-ray fluorescence (µ-XRF) spectroscopy, it was found that a small amount of Ni alters the microstructure of Cu6Sn5 to form a (Cu,Ni)6Sn5 intermetallic layer. The morphology structure of the (Cu,Ni)6Sn5 interfacial intermetallic layer and Sn whisker growth were investigated by scanning electron microscope (SEM) in secondary and backscattered electron imaging mode, which showed that there is a strong correlation between the formation of Sn whisker and the composition of solder alloy. The thickness of the (Cu,Ni)6Sn5 IMC interfacial layer was relatively thinner and more refined, with a continuous fine scallop-shaped IMC interfacial layer, and consequently enhanced a greater incubation period for the nucleation and growth of the Sn whisker. These verification outcomes proposes a scientifically foundation to mitigate Sn whisker growth in lead-free solder joint.
Assessment of Technological Capabilities for Forming Al-C-B System Coatings on Steel Surfaces by Electrospark Alloying Method
Authors: Antoszewski Bogdan , Gaponova Oksana P. , Tarelnyk Viacheslav B. , Myslyvchenko Oleksandr M. , Kurp Piotr , Zhylenko Tetyana I. , Konoplianchenko Ievgen
Published: February 2021

In this paper, the possibility of applying the electrospark alloying (ESA) method to obtain boron-containing coatings characterised by increased hardness and wear resistance is considered. A new method for producing such coatings is proposed. The method consists in applying grease containing aluminium powder and amorphous boron to the surface to be treated and subsequently processing the obtained surface using the ESA method by a graphite electrode. The microstructural analysis of the Al-C-B coatings on steel C40 showed that the surface layer consists of several zones, the number and parameters of which are determined by the energy conditions of the ESA process. Durametric studies showed that with an increase in the discharge energy influence, the microhardness values of both the upper strengthened layer and the diffusion zone increased to Wp = 0.13 J, Hµ = 6487 MPa, and Wp = 4.9 J, Hµ = 12350 MPa, respectively. The results of X-ray diffraction analysis indicate that at the discharge energies of 0.13 and 0.55 J, the phase composition of the coating is represented by solid solutions of body-centred cubic lattice (BCC) and face-centred cubic lattice (FCC). The coatings obtained at Wp = 4.9 J were characterised by the presence of intermetallics Fe4Al13 and borocementite Fe3 (CB) in addition to the solid solutions. The X-ray spectral analysis of the obtained coatings indicated that during the electrospark alloying process, the surface layers were saturated with aluminium, boron, and carbon. With increasing discharge energy, the diffusion zone increases; during the ESA process with the use of the discharge energy of 0.13 J for steel C40, the diffusion zone is 10–15 μm. When replacing a substrate made of steel C40 with the same one material but of steel C22, an increase in the thickness of the surface layer accompanied by a slight decrease in microhardness is observed as a result of processing with the use of the ESA method. There were simulated phase portraits of the Al-C-B coatings. It is shown that near the stationary points in the phase portraits, one can see either a slowing down of the evolution or a spiral twisting of the diffusion-process particle.
Resins for Frontal Photopolymerization: Combining Depth-Cure and Tunable Mechanical Properties
Authors: Ebner Catharina , Mitterer Julia , Gonzalez-Gutierrez Joamin , Rieß Gisbert , Kern Wolfgang
Published: February 2021

Photopolymerization has undergone significant development in recent years. It enables fast and easy processing of materials with customized properties and allows precise printing of complex surface geometries. Nevertheless, photopolymerization is mainly applied to cure thin films since the low curing depth limits the fast production of large volumes. Frontal photopolymerization (FPP) is suitable to overcome these limitations so that curing of centimeter-thick (meth)acrylic layers can be accomplished within minutes by light induction only. Prerequisites, however, are the low optical density of the resin and bleaching ability of the photoinitiator. To date, tailored FPP-resins are not commercially available. This study discusses the potential of long-chain polyether dimethacrylates, offering high-temperature resistance and low optical density, as crosslinkers in photobleaching resins and investigates the mechanical properties of photofrontally-cured copolymers. Characteristics ranging from ductile to hard and brittle are observed in tensile tests, demonstrating that deep curing and versatile material properties are achieved with FPP. Analyzed components display uniform polymerization over a depth of four centimeters in Fourier transform infrared spectroscopy and swelling tests.
Design of Sodium Alginate/Gelatin-Based Emulsion Film Fused with Polylactide Microparticles Charged with Plant Extract
Authors: Prus-Walendziak Weronika , Kozlowska Justyna
Published: February 2021

This study aimed at designing emulsion films based on sodium alginate, gelatin, and glycerol, and their modification by the addition of lipids (cottonseed oil and beeswax). Film composition with the most promising properties was further modified by the incorporation of polylactide (PLA) microparticles with Calendula officinalis flower extract. PLA microspheres were obtained by the emulsion/solvent evaporation method. The size distribution of oily particles in emulsions was investigated. Mechanical properties, moisture content, UV-Vis spectra, and the color of films were analyzed, while biophysical skin parameters were assessed after their application to the skin. Moreover, the contact angles were measured, and the surface free energy of polymeric films was determined. An investigation of the amount of Calendula officinalis flower extract which can be incorporated into PLA microparticles was performed. The modification of the composition of films significantly influenced their physicochemical properties. The selected active ingredient in the form of plant extract was successfully incorporated into polymeric microparticles that were further added into the developed emulsion film. The condition of the skin after the application of obtained emulsion films improved. The prepared materials, especially containing microparticles with plant extract, can be considered for designing new cosmetic forms, such as cosmetic masks, as well as new topical formulations for pharmaceutical delivery.
Explainable AI Framework for Multivariate Hydrochemical Time Series
Authors: Thrun Michael C. , Ultsch Alfred , Breuer Lutz
Published: February 2021

The understanding of water quality and its underlying processes is important for the protection of aquatic environments. With the rare opportunity of access to a domain expert, an explainable AI (XAI) framework is proposed that is applicable to multivariate time series. The XAI provides explanations that are interpretable by domain experts. In three steps, it combines a data-driven choice of a distance measure with supervised decision trees guided by projection-based clustering. The multivariate time series consists of water quality measurements, including nitrate, electrical conductivity, and twelve other environmental parameters. The relationships between water quality and the environmental parameters are investigated by identifying similar days within a cluster and dissimilar days between clusters. The framework, called DDS-XAI, does not depend on prior knowledge about data structure, and its explanations are tendentially contrastive. The relationships in the data can be visualized by a topographic map representing high-dimensional structures. Two state of the art XAIs called eUD3.5 and iterative mistake minimization (IMM) were unable to provide meaningful and relevant explanations from the three multivariate time series data. The DDS-XAI framework can be swiftly applied to new data. Open-source code in R for all steps of the XAI framework is provided and the steps are structured application-oriented.
Bayesian Estimation of Entropy for Burr Type XII Distribution under Progressive Type-II Censored Data
Authors: Wang Xinjing , Gui Wenhao
Published: February 2021

With the rapid development of statistics, information entropy is proposed as an important indicator used to quantify information uncertainty. In this paper, maximum likelihood and Bayesian methods are used to obtain the estimators of the entropy for a two-parameter Burr type XII distribution under progressive type-II censored data. In the part of maximum likelihood estimation, the asymptotic confidence intervals of entropy are calculated. In Bayesian estimation, we consider non-informative and informative priors respectively, and asymmetric and symmetric loss functions are both adopted. Meanwhile, the posterior risk is also calculated to evaluate the performances of the entropy estimators against different loss functions. In a numerical simulation, the Lindley approximation and the Markov chain Monte Carlo method were used to obtain the Bayesian estimates. In turn, the highest posterior density credible intervals of the entropy were derived. Finally, average absolute bias and mean square error were used to evaluate the estimators under different methods, and a real dataset was selected to illustrate the feasibility of the above estimation model.
A Hierarchical Fuzzy-Based Correction Algorithm for the Neighboring Network Hit Problem
Authors: Leiva-Araos Andrés , Allende-Cid Héctor
Published: February 2021

Most humans today have mobile phones. These devices are permanently collecting and storing behavior data of human society. Nevertheless, data processing has several challenges to be solved, especially if it is obtained from obsolete technologies. Old technologies like GSM and UMTS still account for almost half of all devices globally. The main problem in the data is known as neighboring network hit (NNH). An NNH occurs when a cellular device connects to a site further away than it corresponds to by network design, introducing an error in the spatio-temporal mobility analysis. The problems presented by the data are mitigated by eliminating erroneous data or diluting them statistically based on increasing the amount of data processed and the size of the study area. None of these solutions are effective if what is sought is to study mobility in small areas (e.g., Covid-19 pandemic). Elimination of complete records or traces in the time series generates deviations in subsequent analyses; this has a special impact on reduced spatial coverage studies. The present work is an evolution of the previous approach to NNH correction (NFA) and travel inference (TCA), based on binary logic. NFA and TCA combined deliver good travel counting results compared to government surveys (2.37 vs. 2.27, respectively). However, its main contribution is given by the increase in the precision of calculating the distances traveled (37% better than previous studies). In this document, we introduce FNFA and FTCA. Both algorithms are based on fuzzy logic and deliver even better results. We observed an improvement in the trip count (2.29, which represents 2.79% better than NFA). With FNFA and FTCA combined, we observe an average distance traveled difference of 9.2 km, which is 9.8% better than the previous NFA-TCA. Compared to the naive methods (without fixing the NNHs), the improvement rises from 28.8 to 19.6 km (46.9%). We use duly anonymized data from mobile devices from three major cities in Chile. We compare our results with previous works and Government’s Origin and Destination Surveys to evaluate the performance of our solution. This new approach, while improving our previous results, provides the advantages of a model better adapted to the diffuse condition of the problem variables and shows us a way to develop new models that represent open challenges in studies of urban mobility based on cellular data (e.g., travel mode inference).
Sequences of Groups, Hypergroups and Automata of Linear Ordinary Differential Operators
Authors: Chvalina Jan , Novák Michal , Smetana Bedřich , Staněk David
Published: February 2021

The main objective of our paper is to focus on the study of sequences (finite or countable) of groups and hypergroups of linear differential operators of decreasing orders. By using a suitable ordering or preordering of groups linear differential operators we construct hypercompositional structures of linear differential operators. Moreover, we construct actions of groups of differential operators on rings of polynomials of one real variable including diagrams of actions–considered as special automata. Finally, we obtain sequences of hypergroups and automata. The examples, we choose to explain our theoretical results with, fall within the theory of artificial neurons and infinite cyclic groups.
Study on the Effects of Melatonin on Glycemic Control and Periodontal Parameters in Patients with Type II Diabetes Mellitus and Periodontal Disease
Authors: Anton Diana-Maria , Martu Maria-Alexandra , Maris Marius , Maftei George-Alexandru , Sufaru Irina-Georgeta , Tatarciuc Diana , Luchian Ionut , Ioanid Nicoleta , Martu Silvia
Published: February 2021

Background and Objectives: There is evidence that melatonin could improve the periodontal status and also glycemic control of patients with diabetes mellitus. Therefore, the aim of this study was to assess the effects of scaling and root planing plus adjunctive systemic treatment with melatonin on periodontal parameters and glycemic control in patients with type 2 diabetes and chronic periodontitis. Materials and Methods: The study was conducted on 54 subjects with periodontitis and diabetes mellitus randomly assigned to the study group (n = 27, subjects with scaling and root planing + melatonin) or control group (n = 27, subjects with scaling and root planing + placebo). Periodontal parameters (probing depth—PD; clinical attachment loss—CAL; bleeding on probing—BOP; and hygiene level) and glycated hemoglobin (HbA1c) were assessed at baseline and 8 weeks after. Results: At baseline, there were no significant differences between groups, but at the second evaluation 8 weeks later the association of melatonin with the non-surgical periodontal therapy exerted statistically significant improvements, both in periodontal parameters, with a significant decrease in periodontal disease severity, and glycated hemoglobin when compared to the control subjects. Conclusions: In our study, combined non-surgical periodontal treatment and systemic treatment with melatonin provided additional improvements to severe periodontal condition and the glycemic control of patients with diabetes type 2 when compared to non-surgical periodontal treatment alone.
Made in Germany: A Quality Indicator Not Only in the Automobile Industry But Also When It Comes to Skin Replacement: How an Automobile Textile Research Institute Developed a New Skin Substitute
Authors: Haller Herbert Leopold , Rapp Matthias , Popp Daniel , Nischwitz Sebastian Philipp , Kamolz Lars Peter
Published: February 2021

Successful research and development cooperation between a textile research institute, the German Federal Ministry of Education and Research via the Center for Biomaterials and Organ Substitutes, the University of Tübingen, and the Burn Center of Marienhospital, Stuttgart, Germany, led to the development of a fully synthetic resorbable temporary epidermal skin substitute for the treatment of burns, burn-like syndromes, donor areas, and chronic wounds. This article describes the demands of the product and the steps that were taken to meet these requirements. The material choice was based on the degradation and full resorption of polylactides to lactic acid and its salts. The structure and morphology of the physical, biological, and degradation properties were selected to increase the angiogenetic abilities, fibroblasts, and extracellular matrix generation. Water vapor permeability and plasticity were adapted for clinical use. The available scientific literature was screened for the use of this product. A clinical application demonstrated pain relief paired with a reduced workload, fast wound healing with a low infection rate, and good cosmetic results. A better understanding of the product’s degradation process explained the reduction in systemic oxidative stress shown in clinical investigations compared to other dressings, positively affecting wound healing time and reducing the total area requiring skin grafts. Today, the product is in clinical use in 37 countries. This article describes its development, the indications for product growth over time, and the scientific foundation of treatments.
Platelet-Rich Fibrin in Single and Multiple Coronally Advanced Flap for Type 1 Recession: An Updated Systematic Review and Meta-Analysis
Authors: Mancini Leonardo , Tarallo Francesco , Quinzi Vincenzo , Fratini Adriano , Mummolo Stefano , Marchetti Enrico
Published: February 2021

Background and Objectives: The aim of the present systematic review and meta-analysis was to investigate the efficacy of leukocyte–platelet-rich fibrin (L-PRF) in addition to coronally advanced flap (CAF) for the treatment of both single and multiple gingival recessions (GRs) compared to the CAF alone and to the adjunct of connective tissue graft (CTG). Root coverage outcomes using platelet concentrates have gained increased interest. In particular, it has been suggested that adding L-PRF to CAF may provide further benefits in the treatment of GRs. Materials and Methods: An electronic and manual literature search was conducted to identify randomized controlled trials (RTCs) investigating root coverage outcomes with CAF + L-PRF. The outcomes of interest included mean root coverage (mRC), recession reduction, keratinized tissue width (KTW) gain, gingival thickness (GT) gain, and patient-reported outcome measures (PROms) such as pain perception and discomfort. Results: A total of 275 patients and 611 surgical sites were analyzed. L-PRF in adjunct to single CAF seems to show statistically significant results regarding clinical attachment level (CAL) with a weighted means (WM) 0.43 95% CI (−0.04, 0.91), p < 0.0001, GT (WM 0.17 95% CI (−0.02, 0.36), p < 0.0001, and mRC (WM 13.95 95% CI (−1.99, 29.88) p < 0.0001, compared to single CAF alone. Interesting results were obtained from the adjunct of PRF to multiple CAF with respect to multiple CAF alone with an increase in the mRC WM 0.07 95% CI (−30.22, 30.35), p = 0.0001, and PPD change WM 0.26 95% CI (−0.06, 0.58), p < 00001. On the other hand, no statistically significant data were obtained when L-PRF was added to single or multiple CAF combined with CTG according to the included outcomes such as mRC (p = 0.03 overall). Conclusions: L-PRF is a valid alternative to CAF alone. L-PRF compared to CTG in single and multiple CAF showed statistically significant results regarding pain perception and discomfort PROms (p < 0.0001). However, CTG remains the gold standard for treating gingival recession.
Modeling and Simulation of Biogas Production in Full Scale with Time Series Analysis
Authors: Dittmer Celina , Krümpel Johannes , Lemmer Andreas
Published: February 2021

Future biogas plants must be able to produce biogas according to demand, which requires proactive feeding management. Therefore, the simulation of biogas production depending on the substrate supply is assumed. Most simulation models are based on the complex Anaerobic Digestion Model No. 1 (ADM1). The ADM1 includes a large number of parameters for all biochemical and physicochemical process steps, which have to be carefully adjusted to represent the conditions of a respective full-scale biogas plant. Due to a deficiency of reliable measurement technology and process monitoring, nearly none of these parameters are available for full-scale plants. The present research investigation shows a simulation model, which is based on the principle of time series analysis and uses only historical data of biogas formation and solid substrate supply, without differentiation of individual substrates. The results of an extensive evaluation of the model over 366 simulations with 48-h horizon show a mean absolute percentage error (MAPE) of 14–18%. The evaluation is based on two different digesters and demonstrated that the model is self-learning and automatically adaptable to the respective application, independent of the substrate’s composition.
Special Issue “Salmonella: Pathogenesis and Host Restriction”
Authors: Daigle France
Published: February 2021

Bacteria of the Salmonella genus include several serovars that are closely related, although they can colonize different ecological niches, different hosts, and cause different diseases [...]
Development and Validation of an Automated Zone Fluidics-Based Sensor for In Vitro Dissolution Studies of Captopril Using Total Error Concept
Authors: Karakosta Theano D. , Tzanavaras Paraskevas D. , Zacharis Constantinos K.
Published: February 2021

In the present research, a zone fluidics-based automated sensor for the analysis of captopril in in vitro dissolution samples is reported. Captopril is reacted under flow conditions with Ni(II) (10 mmol L−1) in alkaline medium (0.15% v/v NH3) to form a stable derivate, which is monitored spectrophotometrically at 340 nm. The chemical and instrumental parameters were carefully investigated and optimized. The validation of the developed method was performed in the range of 5 to 120% of the expected maximum concentration using the accuracy profiles as a graphical decision-making tool. The β-expectation tolerance intervals did not exceed the acceptance criteria of ±10%, which means that 95% of future results will be encompassed in the defined bias limits. The variation of the relative bias ranged between −2.3% and 3.5% and the RSD values for repeatability and intermediate precision were lower than 2.3% in all cases. The limit of detection (LOD), and the lower and the upper limit of quantification (LLOQ, ULOQ) were satisfactory and found to be 1%, 5% and 120% (corresponding to 0.6, 2.78 and 66.67 μg mL−1 in dissolution medium). The developed method was successfully applied for the analysis of captopril in dissolution tests of two commercially available batches.
Facile and Rapid Isolation of Oxypeucedanin Hydrate and Byakangelicin from Angelica dahurica by Using [Bmim]Tf2N Ionic Liquid
Authors: Kiyonga Alice Nguvoko , Hong Gyeongmin , Kim Hyun Su , Suh Young-Ger , Jung Kiwon
Published: February 2021

Ionic liquids (ILs) have sparked much interest as alternative solvents for plant materials as they provide distinctive properties. Therefore, in this study, the capacity of ILs to extract oxypeucedanin hydrate and byakangelicin from the roots of Angelica dahurica (A. dahurica) was investigated. The back-extraction method was examined to recover target components from the IL solution as well. Herein, [Bmim]Tf2N demonstrated outstanding performance for extracting oxypeucedanin hydrate and byakangelicin. Moreover, factors including solvent/solid ratio, extraction temperature and time were investigated and optimized using a statistical approach. Under optimum extraction conditions (solvent/solid ratio 8:1, temperature 60 °C and time 180 min), the yields of oxypeucedanin hydrate and byakangelicin were 98.06% and 99.52%, respectively. In addition, 0.01 N HCl showed the most significant ability to back-extract target components from the [Bmim]Tf2N solution. The total content of both oxypeucedanin hydrate (36.99%) and byakangelicin (45.12%) in the final product exceeded 80%. Based on the data, the proposed approach demonstrated satisfactory extraction ability, recovery and enrichment of target compounds in record time. Therefore, the developed approach is assumed essential to considerably reduce drawbacks encountered during the separation of oxypeucedanin hydrate and byakangelicin from the roots of A. dahurica.
Exploring the Interplay between Drug Release and Targeting of Lipid-Like Polymer Nanoparticles Loaded with Doxorubicin
Authors: Kovshova Tatyana , Osipova Nadezhda , Alekseeva Anna , Malinovskaya Julia , Belov Alexey , Budko Andrey , Pavlova Galina , Maksimenko Olga , Nagpal Shakti , Braner Svenja , Modh Harshvardhan , Balabanyan Vadim , Wacker Matthias G. , Gelperina Svetlana
Published: February 2021

Targeted delivery of doxorubicin still poses a challenge with regards to the quantities reaching the target site as well as the specificity of the uptake. In the present approach, two colloidal nanocarrier systems, NanoCore-6.4 and NanoCore-7.4, loaded with doxorubicin and characterized by different drug release behaviors were evaluated in vitro and in vivo. The nanoparticles utilize a specific surface design to modulate the lipid corona by attracting blood-borne apolipoproteins involved in the endogenous transport of chylomicrons across the blood–brain barrier. When applying this strategy, the fine balance between drug release and carrier accumulation is responsible for targeted delivery. Drug release experiments in an aqueous medium resulted in a difference in drug release of approximately 20%, while a 10% difference was found in human serum. This difference affected the partitioning of doxorubicin in human blood and was reflected by the outcome of the pharmacokinetic study in rats. For the fast-releasing formulation NanoCore-6.4, the AUC0→1h was significantly lower (2999.1 ng × h/mL) than the one of NanoCore-7.4 (3589.5 ng × h/mL). A compartmental analysis using the physiologically-based nanocarrier biopharmaceutics model indicated a significant difference in the release behavior and targeting capability. A fraction of approximately 7.310–7.615% of NanoCore-7.4 was available for drug targeting, while for NanoCore-6.4 only 5.740–6.057% of the injected doxorubicin was accumulated. Although the targeting capabilities indicate bioequivalent behavior, they provide evidence for the quality-by-design approach followed in formulation development.
Upgrading Solid Digestate from Anaerobic Digestion of Agricultural Waste as Performance Enhancer for Starch-Based Mulching Biofilm
Authors: Zhao Nan , Mou Huawei , Zhou Yuguang , Ju Xinxin , Yang Shoujun , Liu Shan , Dong Renjie
Published: February 2021

Developing a green and sustainable method to upgrade biogas wastes into high value-added products is attracting more and more public attention. The application of solid residues as a performance enhancer in the manufacture of biofilms is a prospective way to replace conventional plastic based on fossil fuel. In this work, solid digestates from the anaerobic digestion of agricultural wastes, such as straw, cattle and chicken manures, were pretreated by an ultrasonic thermo-alkaline treatment to remove the nonfunctional compositions and then incorporated in plasticized starch paste to prepare mulching biofilms by the solution casting method. The results indicated that solid digestate particles dispersed homogenously in the starch matrix and gradually aggregated under the action of a hydrogen bond, leading to a transformation of the composites to a high crystalline structure. Consequently, the composite biofilm showed a higher tensile strength, elastic modulus, glass transition temperature and degradation temperature compared to the pure starch-based film. The light, water and GHG (greenhouse gas) barrier properties of the biofilm were also reinforced by the addition of solid digestates, performing well in sustaining the soil quality and minimizing N2O or CH4 emissions. As such, recycling solid digestates into a biodegradable plastic substitute not only creates a new business opportunity by producing high-performance biofilms but also reduces the environmental risk caused by biogas waste and plastics pollution.
Lignins Isolated via Catalyst-Free Organosolv Pulping from Miscanthus x giganteus, M. sinensis, M. robustus and M. nagara: A Comparative Study
Authors: Bergs Michel , Monakhova Yulia , Diehl Bernd W. , Konow Christopher , Völkering Georg , Pude Ralf , Schulze Margit
Published: February 2021

As a low-input crop, Miscanthus offers numerous advantages that, in addition to agricultural applications, permits its exploitation for energy, fuel, and material production. Depending on the Miscanthus genotype, season, and harvest time as well as plant component (leaf versus stem), correlations between structure and properties of the corresponding isolated lignins differ. Here, a comparative study is presented between lignins isolated from M. x giganteus, M. sinensis, M. robustus and M. nagara using a catalyst-free organosolv pulping process. The lignins from different plant constituents are also compared regarding their similarities and differences regarding monolignol ratio and important linkages. Results showed that the plant genotype has the weakest influence on monolignol content and interunit linkages. In contrast, structural differences are more significant among lignins of different harvest time and/or season. Analyses were performed using fast and simple methods such as nuclear magnetic resonance (NMR) spectroscopy. Data was assigned to four different linkages (A: β-O-4 linkage, B: phenylcoumaran, C: resinol, D: β-unsaturated ester). In conclusion, A content is particularly high in leaf-derived lignins at just under 70% and significantly lower in stem and mixture lignins at around 60% and almost 65%. The second most common linkage pattern is D in all isolated lignins, the proportion of which is also strongly dependent on the crop portion. Both stem and mixture lignins, have a relatively high share of approximately 20% or more (maximum is M. sinensis Sin2 with over 30%). In the leaf-derived lignins, the proportions are significantly lower on average. Stem samples should be chosen if the highest possible lignin content is desired, specifically from the M. x giganteus genotype, which revealed lignin contents up to 27%. Due to the better frost resistance and higher stem stability, M. nagara offers some advantages compared to M. x giganteus. Miscanthus crops are shown to be very attractive lignocellulose feedstock (LCF) for second generation biorefineries and lignin generation in Europe.
The Magnetization of a Composite Based on Reduced Graphene Oxide and Polystyrene
Authors: Ionov Alexander N. , Volkov Mikhail P. , Nikolaeva Marianna N. , Smyslov Ruslan Y. , Bugrov Alexander N.
Published: February 2021

The use of reduced graphene oxide (r-GO) is a promising way of fabricating organic–inorganic composites with unique electrical and magnetic properties. In our work, polystyrene/r-GO composites were synthesized, in which both the components are linked together by covalent bonds. The r-GO used differs from the graphene obtained from graphite through mechanical exfoliation using the ‘scotch tape’ by presenting many structural defects. Binding in the composite structure between the components was confirmed by infrared spectroscopy. Elemental analysis was carried out by energy dispersive X-ray spectroscopy. Scanning electron microscopy, X-ray diffraction, and Raman spectroscopy were used to monitor the 2D-order in exfoliated r-GO galleries. Using a vibrating-sample magnetometer, we have shown that the composite magnetization loops demonstrate type-II superconductivity up to room temperature due to r-GO flakes. We believe that a strain field in the r-GO flakes covalently binding to a polymeric matrix is responsible for the superconductivity phenomena.
Graphene-Based Scaffolds for Regenerative Medicine
Authors: Bellet Pietro , Gasparotto Matteo , Pressi Samuel , Fortunato Anna , Scapin Giorgia , Mba Miriam , Menna Enzo , Filippini Francesco
Published: February 2021

Leading-edge regenerative medicine can take advantage of improved knowledge of key roles played, both in stem cell fate determination and in cell growth/differentiation, by mechano-transduction and other physicochemical stimuli from the tissue environment. This prompted advanced nanomaterials research to provide tissue engineers with next-generation scaffolds consisting of smart nanocomposites and/or hydrogels with nanofillers, where balanced combinations of specific matrices and nanomaterials can mediate and finely tune such stimuli and cues. In this review, we focus on graphene-based nanomaterials as, in addition to modulating nanotopography, elastic modulus and viscoelastic features of the scaffold, they can also regulate its conductivity. This feature is crucial to the determination and differentiation of some cell lineages and is of special interest to neural regenerative medicine. Hereafter we depict relevant properties of such nanofillers, illustrate how problems related to their eventual cytotoxicity are solved via enhanced synthesis, purification and derivatization protocols, and finally provide examples of successful applications in regenerative medicine on a number of tissues.
Two-Step Triethylamine-Based Synthesis of MgO Nanoparticles and Their Antibacterial Effect against Pathogenic Bacteria
Authors: Muñiz Diaz Ramiro , Cardoso-Avila Pablo Eduardo , Pérez Tavares José Antonio , Patakfalvi Rita , Villa Cruz Virginia , Pérez Ladrón de Guevara Héctor , Gutiérrez Coronado Oscar , Arteaga Garibay Ramón Ignacio , Saavedra Arroyo Quetzalcoatl Enrique , Marañón-Ruiz Virginia Francisca , Castañeda Contreras Jesús
Published: February 2021

Magnesium oxide nanoparticles (MgO NPs) were obtained by the calcination of precursor microparticles (PM) synthesized by a novel triethylamine-based precipitation method. Scanning electron microscopy (SEM) revealed a mean size of 120 nm for the MgO NPs. The results of the characterizations for MgO NPs support the suggestion that our material has the capacity to attack, and have an antibacterial effect against, Gram-negative and Gram-positive bacteria strains. The ability of the MgO NPs to produce reactive oxygen species (ROS), such as superoxide anion radicals (O2•−) or hydrogen peroxide (H2O2), was demonstrated by the corresponding quantitative assays. The MgO antibacterial activity was evaluated against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria, with minimum inhibitory concentrations (MICs) of 250 and 500 ppm on the microdilution assays, respectively. Structural changes in the bacteria, such as membrane collapse; surface changes, such as vesicular formation; and changes in the longitudinal and horizontal sizes, as well as the circumference, were observed using atomic force microscopy (AFM). The lipidic peroxidation of the bacterial membranes was quantified, and finally, a bactericidal mechanism for the MgO NPs was also proposed.
Ionic Transport in CsNO2-Based Nanocomposites with Inclusions of Surface Functionalized Nanodiamonds
Authors: Mateyshina Yulia G. , Alekseev Dmitriy V. , Uvarov Nikolai F.
Published: February 2021

Composite solid electrolytes (1 − x)CsNO2-xND, where ND are nanodiamonds, including those after liquid-phase and gas-phase oxidation and reduction functionalization, were prepared, and their properties investigated by XRD, analysis of BET nitrogen adsorption isotherms, IR spectroscopy and impedance spectroscopy. The electrical conductivity of composites (1 − x)CsNO2-xND obeys the Arrhenius dependence and has a maximum at x = 0.95 regardless of the ND pretreatment. It was found that the conductivity depends on the mode of functionalization of the ND surface, as well as on the processing time. The electrical conductivity of composites with ND, processed by the gas-phase method, is 1.5–2.6 times higher than that of composites with initial ND, in which the conductivity is 2 orders of magnitude higher than that of pure cesium nitrate. Thus, the possibility of using ND as an effective heterogeneous additive for the preparation of composite solid electrolytes, including cesium nitrite, has been demonstrated for the first time.
Hypothalamic Inflammation as a Potential Pathophysiologic Basis for the Heterogeneity of Clinical, Hormonal, and Metabolic Presentation in PCOS
Authors: Barlampa Danai , Bompoula Maria Sotiria , Bargiota Alexandra , Kalantaridou Sophia , Mastorakos George , Valsamakis Georgios
Published: February 2021

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age. It is a heterogeneous condition characterized by reproductive, endocrine, metabolic, and psychiatric abnormalities. More than one pathogenic mechanism is involved in its development. On the other hand, the hypothalamus plays a crucial role in many important functions of the body, including weight balance, food intake, and reproduction. A high-fat diet with a large amount of long-chain saturated fatty acids can induce inflammation in the hypothalamus. Hypothalamic neurons can sense extracellular glucose concentrations and participate, with a feedback mechanism, in the regulation of whole-body glucose homeostasis. When consumed nutrients are rich in fat and sugar, and these regulatory mechanisms can trigger inflammatory pathways resulting in hypothalamic inflammation. The latter has been correlated with metabolic diseases, obesity, and depression. In this review, we explore whether the pattern and the expansion of hypothalamic inflammation, as a result of a high-fat and -sugar diet, may contribute to the heterogeneity of the clinical, hormonal, and metabolic presentation in PCOS via pathophysiologic mechanisms affecting specific areas of the hypothalamus. These mechanisms could be potential targets for the development of effective therapies for the treatment of PCOS.
The Current and Potential Therapeutic Use of Metformin—The Good Old Drug
Authors: Drzewoski Józef , Hanefeld Markolf
Published: February 2021

Metformin, one of the oldest oral antidiabetic agents and still recommended by almost all current guidelines as the first-line treatment for type 2 diabetes mellitus (T2DM), has become the medication with steadily increasing potential therapeutic indications. A broad spectrum of experimental and clinical studies showed that metformin has a pleiotropic activity and favorable effect in different pathological conditions, including prediabetes, type 1 diabetes mellitus (T1DM) and gestational diabetes mellitus (GDM). Moreover, there are numerous studies, meta-analyses and population studies indicating that metformin is safe and well tolerated and may be associated with cardioprotective and nephroprotective effect. Recently, it has also been reported in some studies, but not all, that metformin, besides improvement of glucose homeostasis, may possibly reduce the risk of cancer development, inhibit the incidence of neurodegenerative disease and prolong the lifespan. This paper presents some arguments supporting the initiation of metformin in patients with newly diagnosed T2DM, especially those without cardiovascular risk factors or without established cardiovascular disease or advanced kidney insufficiency at the time of new guidelines favoring new drugs with pleotropic effects complimentary to glucose control. Moreover, it focuses on the potential beneficial effects of metformin in patients with T2DM and coexisting chronic diseases.
Targeting Cartilage Degradation in Osteoarthritis
Authors: McClurg Oliver , Tinson Ryan , Troeberg Linda
Published: February 2021

Osteoarthritis is a common, degenerative joint disease with significant socio-economic impact worldwide. There are currently no disease-modifying drugs available to treat the disease, making this an important area of pharmaceutical research. In this review, we assessed approaches being explored to directly inhibit metalloproteinase-mediated cartilage degradation and to counteract cartilage damage by promoting growth factor-driven repair. Metalloproteinase-blocking antibodies are discussed, along with recent clinical trials on FGF18 and Wnt pathway inhibitors. We also considered dendrimer-based approaches being developed to deliver and retain such therapeutics in the joint environment. These may reduce systemic side effects while improving local half-life and concentration. Development of such targeted anabolic therapies would be of great benefit in the osteoarthritis field.
Effects of Surface Protein Adsorption on the Distribution and Retention of Intratumorally Administered Gold Nanoparticles
Authors: Terracciano Rossana , Zhang Aobo , Butler E. Brian , Demarchi Danilo , Hafner Jason H. , Grattoni Alessandro , Filgueira Carly S.
Published: February 2021

The heterogeneous distribution of delivery or treatment modalities within the tumor mass is a crucial limiting factor for a vast range of theranostic applications. Understanding the interactions between a nanomaterial and the tumor microenvironment will help to overcome challenges associated with tumor heterogeneity, as well as the clinical translation of nanotheranostic materials. This study aims to evaluate the influence of protein surface adsorption on gold nanoparticle (GNP) biodistribution using high-resolution computed tomography (CT) preclinical imaging in C57BL/6 mice harboring Lewis lung carcinoma (LLC) tumors. LLC provides a valuable model for study due to its highly heterogenous nature, which makes drug delivery to the tumor challenging. By controlling the adsorption of proteins on the GNP surface, we hypothesize that we can influence the intratumoral distribution pattern and particle retention. We performed an in vitro study to evaluate the uptake of GNPs by LLC cells and an in vivo study to assess and quantify the GNP biodistribution by injecting concentrated GNPs citrate-stabilized or passivated with bovine serum albumin (BSA) intratumorally into LLC solid tumors. Quantitative CT and inductively coupled plasma optical emission spectrometry (ICP-OES) results both confirm the presence of particles in the tumor 9 days post-injection (n = 8 mice/group). A significant difference is highlighted between citrate-GNP and BSA-GNP groups (** p < 0.005, Tukey’s multiple comparisons test), confirming that the protein corona of GNPs modifies intratumoral distribution and retention of the particles. In conclusion, our investigations show that the surface passivation of GNPs influences the mechanism of cellular uptake and intratumoral distribution in vivo, highlighting the spatial heterogeneity of the solid tumor.
A Core Module of Nuclear Genes Regulated by Biogenic Retrograde Signals from Plastids
Authors: Grübler Björn , Cozzi Carolina , Pfannschmidt Thomas
Published: February 2021

Chloroplast biogenesis during seedling development of angiosperms is a rapid and highly dynamic process that parallels the light-dependent photomorphogenic programme. Pre-treatments of dark-grown seedlings with lincomyin or norflurazon prevent chloroplast biogenesis upon illumination yielding albino seedlings. A comparable phenotype was found for the Arabidopsis mutant plastid-encoded polymerase associated protein 7 (pap7) being defective in the prokaryotic-type plastid RNA polymerase. In all three cases the defect in plastid function has a severe impact on the expression of nuclear genes representing the influence of retrograde signaling pathway(s) from the plastid. We performed a meta-analysis of recently published genome-wide expression studies that investigated the impact of the aforementioned chemical and genetic blocking of chloroplast biogenesis on nuclear gene expression profiles. We identified a core module of 152 genes being affected in all three conditions. These genes were classified according to their function and analyzed with respect to their implication in retrograde signaling and chloroplast biogenesis. Our study uncovers novel genes regulated by retrograde biogenic signals and suggests the action of a common signaling pathway that is used by signals originating from plastid transcription, translation and oxidative stress.
Covalent Functionalization of Graphene Oxide with Fructose, Starch, and Micro-Cellulose by Sonochemistry
Authors: Cruz-Benítez María Montserrat , Gónzalez-Morones Pablo , Hernández-Hernández Ernesto , Villagómez-Ibarra José Roberto , Castro-Rosas Javier , Rangel-Vargas Esmeralda , Fonseca-Florido Heidi Andrea , Gómez-Aldapa Carlos Alberto
Published: February 2021

In this work, we report the synthesis of graphene oxide (GO) nanohybrids with starch, fructose, and micro-cellulose molecules by sonication in an aqueous medium at 90 °C and a short reaction time (30 min). The final product was washed with solvents to extract the nanohybrids and separate them from the organic molecules not grafted onto the GO surface. Nanohybrids were chemically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy and analyzed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). These results indicate that the ultrasound energy promoted a chemical reaction between GO and the organic molecules in a short time (30 min). The chemical characterization of these nanohybrids confirms their covalent bond, obtaining a grafting percentage above 40% the weight in these nanohybrids. This hybridization creates nanometric and millimetric nanohybrid particles. In addition, the grafted organic molecules can be crystallized on GO films. Interference in the ultrasound waves of starch hybrids is due to the increase in viscosity, leading to a partial hybridization of GO with starch.