bluuebunny/crossref_metadata_2025 huggingface dataset:
Light-Emitting Lanthanide Periodic Mesoporous Organosilica (PMO) Hybrid Materials
Authors: Kaczmarek Anna M. , Van Der Voort Pascal
Published: January 2020

Periodic mesoporous organosilicas (PMOs) have a well ordered mesoporous structure, a high thermal and mechanical stability and a uniform distribution of organic functionalities in the pore walls. The organic groups allow PMOs to be modified and functionalized by using a wide range of organic reactions. Since their first report in 1999, PMOs have found a vast range of applications, such as for catalysis, adsorbents, low-k films, biomedical supports and also for optical applications. Optical applications are very interesting as PMOs offer the possibility of designing advanced luminescent hybrid materials comprising of organic components, yet with much higher stability and very good processability. Despite their promising possibilities, the optical properties of pristine PMOs and PMOs grafted with d-metal or f-metal ions and complexes have been explored less frequently. In this review, we aimed to overview the exciting light emitting properties of various reported lanthanide PMO hybrid materials and interest the reader in this promising application for lanthanide PMO materials.
Estimation of Specific Cutting Energy in an S235 Alloy for Multi-Directional Ultrasonic Vibration-Assisted Machining Using the Finite Element Method
Authors: Flórez García Luis C. , González Rojas Hernán A. , Sánchez Egea Antonio J.
Published: January 2020

The objective of this work is to analyze the influence of the vibration-assisted turning process on the machinability of S235 carbon steel. During the experiments using this vibrational machining process, the vibrational amplitude and frequency of the cutting tool were adjusted to drive the tool tip in an elliptical or linear motion in the feed direction. Furthermore, a finite element analysis was deployed to investigate the mechanical response for different vibration-assisted cutting conditions. The results show how the specific cutting energy and the material’s machinability behave when using different operational cutting parameters, such as vibration frequency and tool tip motion in the x-axis, y-axis, and elliptical (x-y plane) motion. Then, the specific cutting energy and material’s machinability are compared with a conventional turning process, which helps to validate the finite element method (FEM) for the vibration-assisted process. As a result of the operating parameters used, the vibration-assisted machining process leads to a machinability improvement of up to 18% in S235 carbon steel. In particular, higher vibration frequencies were shown to increase the material’s machinability due to the specific cutting energy decrease. Therefore, the finite element method can be used to predict the vibration-assisted cutting and the specific cutting energy, based on predefined cutting parameters.
Dendrimers: Amazing Platforms for Bioactive Molecule Delivery Systems
Authors: Sandoval-Yañez Claudia , Castro Rodriguez Cristian
Published: January 2020

Today, dendrimers are the main nanoparticle applied to drug delivery systems. The physicochemical characteristics of dendrimers and their versatility structural modification make them attractive to applied as a platform to bioactive molecules transport. Nanoformulations based on dendrimers enhance low solubility drugs, arrival to the target tissue, drugs bioavailability, and controlled release. This review describes the latter approaches on the transport of bioactive molecules based on dendrimers. The review focus is on the last therapeutic strategies addressed by dendrimers conjugated with bioactive molecules. A brief review of the latest studies in therapies against cancer and cardiovascular diseases, as well as future projections in the area, are addressed.
Internal GFRP Reinforcement of Low-Grade Maritime Pine Duo Timber Beams
Authors: Balmori Jose-Antonio , Basterra Luis-Alfonso , Acuña Luis
Published: January 2020

This paper presented an experimental structural-scale test campaign used to analyze the flexural behavior of low-grade maritime pine (Pinus pinaster Ait.) duo timber beams reinforced with an internal glass fiber-reinforced polymer (GFRP) sheet. For this purpose, thirty (30) unreinforced duo beams and thirty (30) duo beams internally reinforced with a unidirectional GFRP sheet with an areal mass of 1200 g/m2 were produced and tested. The addition of a low GFRP reinforcement ratio (1.07%) in the tension zone of the duo beams provided an average improvement of 8.37% in bending stiffness (EI) and an increase of up to 18.45% in ultimate moment capacity. In addition to this improved bending behavior, the internal GFRP reinforcements seemed to decrease the influence of wood singularities and wood heterogeneity on mechanical properties, which allowed for better characteristic values to be reached and for the achievement of results with less variability.
Shaping Ability, Cyclic Fatigue Resistance and Fractographic Analysis of Hybrid and Reciprocating Nickel Titanium Endodontic Instruments
Authors: Drukteinis Saulius , Peciuliene Vytaute , Bendinskaite Ruta , Brukiene Vilma , Maneliene Rasmute , Nedzinskiene Egle
Published: January 2020

The aim of this study was to investigate the shaping ability and cyclic fatigue resistance of Genius (GN) and WaveOne (WO) nickel-titanium (NiTi) instruments. Forty mesial root canals of mandibular molars were randomly divided into two groups, according to the instrument system used for root canal preparation (n = 20): GN and WO. Root canals were prepared to the full working length using the crown-down technique, with up to 40.04 instruments for GN group and 40.08 instruments for WO group. Specimens were scanned with a µCT before and after instrumentation. The changes in 3D parameters and degree of canal transportation were evaluated in the apical, middle and coronal thirds of root canals. Size 25, taper 0.04 (GN) and 0.08 (WO) instruments (n = 20) were used in simulated root canals until fracturing, and the number of cycles to failure (NCF) was recorded. The fractured files were investigated under a scanning electron microscope to characterize fractured surfaces. Data were analyzed using ANOVA post hoc Tuckey’s tests with the significance level set at 5%. The GN system was able to prepare the higher percentage of the canal surface with less canal transportation in all root canal thirds and displayed the higher resistance to cyclic fatigue in comparison to WO instruments (p < 0.05). However, the length of the fractured segments was not significantly different among the groups; meanwhile, SEM investigations revealed the typical topographic characteristics of fractured surfaces. Hybrid GN instruments demonstrated superior shaping ability and resistance to cyclic fatigue. However, both NiTi instrument systems prepared the root canals with no significant shaping errors, considerable changes in 3D parameters and no significant differences in the topographic appearances of the instrument surfaces after fractures.
Influence of Wavy Bending on Microstructure and Mechanical Properties of a Rolled AZ31 Sheet
Authors: Liu Tingting , Zhang Yuyang , Chen Yanan , Du Zhiwen , Chen Hongbing , Yang Qingshan , Song Bo
Published: January 2020

In the present work, cross-wavy bending at room temperature was carried out to tailor the microstructure and stretch formability of rolled AZ31 sheets. Wavy bending processing generates profuse {10–12} twins and a tilt basal texture. Subsequent recrystallization annealing causes grain coarsening and enhances the intensity of twin-orientation. The combined use of wavy bending and annealing can maintain high tensile ductility and remarkably enhances the stretch formability of rolled AZ31 sheet. It can be mainly attributed to the non-basal texture in the wavy bent sheet which increases the thinning capability during in-plane tension.
Proportional Microvalve Using a Unimorph Piezoelectric Microactuator
Authors: Gunda Arun , Özkayar Gürhan , Tichem Marcel , Ghatkesar Murali Krishna
Published: January 2020

Microvalves are important flow-control devices in many standalone and integrated microfluidic applications. Polydimethylsiloxane (PDMS)-based pneumatic microvalves are commonly used but they generally require large peripheral connections that decrease portability. There are many alternatives found in the literature that use Si-based microvalves, but variants that can throttle even moderate pressures (1 bar) tend to be bulky (cm-range) or consume high power. This paper details the development of a low-power, normally-open piezoelectric microvalve to control flows with a maximum driving pressure of 1 bar, but also retain a small effective form-factor of 5 mm × 5 mm × 1.8 mm. A novel combination of rapid prototyping methods like stereolithography and laser-cutting have been used to realize this device. The maximum displacement of the fabricated piezoelectric microactuator was measured to be 8.5 μm at 150 V. The fabricated microvalve has a flow range of 0–90 μL min−1 at 1 bar inlet pressure. When fully closed, a leakage of 0.8% open-flow was observed with a power-consumption of 37.5 μW. A flow resolution of 0.2 μL min−1—De-ionized (DI) water was measured at 0.5 bar pressure.
A New Reference for the Thermal Equation of State of Iron
Authors: Miozzi Francesca , Matas Jan , Guignot Nicolas , Badro James , Siebert Julien , Fiquet Guillaume
Published: January 2020

The high-pressure, high-temperature behavior of iron was investigated to 140 GPa and 3500 K with in situ synchrotron X-ray diffraction. Iron samples were compressed in diamond-anvil cells and heated up with the double-sided laser-heating system installed at the high-pressure ID27 of the European Synchrotron Radiation Facility (ESRF). Three different structures, namely α-bcc, γ-fcc or ε-hcp Fe were identified as a function of pressure and temperature in the domain we explored. At pressures above 90 GPa, it is clearly shown that ε-iron is the single stable solid phase up to 160 GPa at high temperatures. The analysis of the P-V-T relationship allows us to propose a reliable experimental thermal equation of state (EoS) for iron. We also show that the addition of low pressure points to our EoS refinement yields more robust constrain on the determination of the reference volume V0 of the ε-hcp structure, which has important implications on the final parametrization of the equation of state. The extrapolation of the proposed EoS to core pressure conditions indicates that a pure iron core would have an excess of density of 3% compared to the PREM density profile.
Multivalent Lactose–Ferrocene Conjugates Based on Poly (Amido Amine) Dendrimers and Gold Nanoparticles as Electrochemical Probes for Sensing Galectin-3
Authors: Martos-Maldonado Manuel C. , Quesada-Soriano Indalecio , García-Fuentes Luis , Vargas-Berenguel Antonio
Published: January 2020

Galectin-3 is considered a cancer biomarker and bioindicator of fibrosis and cardiac remodeling and, therefore, it is desirable to develop convenient methods for its detection. Herein, an approach based on the development of multivalent electrochemical probes with high galectin-3 sensing abilities is reported. The probes consist of multivalent presentations of lactose–ferrocene conjugates scaffolded on poly (amido amine) (PAMAM) dendrimers and gold nanoparticles. Such multivalent lactose–ferrocene conjugates are synthesized by coupling of azidomethyl ferrocene–lactose building blocks on alkyne-functionalized PAMAM, for the case of the glycodendrimers, and to disulfide-functionalized linkers that are then used for the surface modification of citrate-stabilized gold nanoparticles. The binding and sensing abilities toward galectin-3 of both ferrocene-containing lactose dendrimers and gold nanoparticles have been evaluated by means of isothermal titration calorimetry, UV–vis spectroscopy, and differential pulse voltammetry. The highest sensitivity by electrochemical methods to galectin-3 was shown by lactosylferrocenylated gold nanoparticles, which are able to detect the lectin in nanomolar concentrations.
Novel Insights on Intake of Fish and Prevention of Sarcopenia: All Reasons for an Adequate Consumption
Authors: Rondanelli Mariangela , Rigon Chiara , Perna Simone , Gasparri Clara , Iannello Giancarlo , Akber Rashida , Alalwan Tariq A. , Freije Afnan Mahmood
Published: January 2020

Sarcopenia is defined as a syndrome characterized by progressive and generalized loss of skeletal muscle mass and strength and it is diagnosed by measurements of muscle mass, muscle strength, and physical performance. Sarcopenia affects quality of life and is associated with several adverse health effects. Muscle decline is aggravated by a sedentary lifestyle and can be prevented through proper nutrition, together with adequate physical activity. Fish contains biologically active compounds, such as omega-3 polyunsaturated fatty acids, proteins, vitamin D, magnesium, and carnitine, which are able to intervene positively on muscle metabolism. This narrative literature review was performed to evaluate evidence regarding the actual benefit of fish consumption in the prevention of sarcopenia and the positive action on the muscle mass of the biological compounds present in fish. The results demonstrated that fish consumption has a protective and anti-inflammatory function on skeletal muscle and that its biologically active compounds help to maintain good muscle performance, preventing sarcopenia. Considering the nutritional and health benefits, elderly with sarcopenia should consume at least three servings per week of fish in order to have a minimum intake of 4–4.59 g daily of omega 3, and reaching the 50% RDA in Vitamin E and D. High biological value of proteins in 150 g of fish and its high available magnesium (20% of RDA in 150 g of fish) are an added value that could suggest fish as a “functional food” in order to prevent and treat sarcopenia.
Exposures Associated with Non-Typhoidal Salmonella Infections Caused by Newport, Javiana, and Mississippi Serotypes in Tennessee, 2013–2015: A Case-Case Analysis
Authors: Mukherjee Nabanita , Nolan Vikki G. , Dunn John R. , Banerjee Pratik
Published: January 2020

Non-typhoidal Salmonella (NTS) infection (salmonellosis) is one of the most prevalent gastrointestinal diseases throughout the world. Human infections caused by Salmonella Newport, Javiana, and Mississippi serotypes have been observed to occur at higher rates on an annual basis in western Tennessee. The reason for the increased rate of NTS infection by these three serotypes in this region is not known. We conducted a case-case analysis to identify potential risk factors associated with the three Salmonella serotypes using FoodNet data, obtained from the Tennessee Department of Health, consisting of 1578 culture-confirmed salmonellosis cases in Tennessee from 2013 through 2015. Among all the exposure variables tested (254 in total), we found contact with pet treats or chews in the seven days prior to illness was the factor that was significantly associated with these serotypes compared to other serotypes (odds ratio adjusted = 3.0 (95% confidence intervals 1.6, 5.5), P < 0.0005). This study highlights the need for further investigation of potential exposures (other than pet treats or chews), including several possible environmental sources of NTS infection in humans.
Solid State Stability and Kinetics of Degradation for Candesartan—Pure Compound and Pharmaceutical Formulation
Authors: Buda Valentina , Baul Bianca , Andor Minodora , Man Dana Emilia , Ledeţi Adriana , Vlase Gabriela , Vlase Titus , Danciu Corina , Matusz Petru , Peter Francisc , Ledeţi Ionuţ
Published: January 2020

The aim of this work was to assess the impact of an excipient in a pharmaceutical formulation containing candesartan cilexetil over the decomposition of the active pharmaceutical ingredient and to comparatively investigate the kinetics of degradation during thermolysis in an oxidative atmosphere under controlled thermal stress. To achieve this, the samples were chosen as follows: pure candesartan cilexetil and a commercial tablet of 32 mg strength. As a first investigational tool, Universal attenuated total reflection Fourier transform infrared (UATR-FTIR) spectroscopy was chosen in order to confirm the purity and identity of the samples, as well as to check if any interactions took place in the tablet between candesartan cilexetil and excipients under ambient conditions. Later on, samples were investigated by thermal analysis, and the elucidation of the decomposition mechanism was achieved solely after performing an in-depth kinetic study, namely the use of the modified non-parametric kinetics (NPK) method, since other kinetic methods (American Society for Testing and Materials—ASTM E698, Friedman and Flynn–Wall–Ozawa) led to inadvertencies. The NPK method suggested that candesartan cilexetil and the tablet were degraded by the contribution of two steps, the main being represented by chemical degradation and the secondary being a physical transformation. The excipients chosen in the formulation seemed to have a stabilizing effect on the decomposition of the candesartan cilexetil that was incorporated into the tablet, relative to pure active pharmaceutical ingredient (API), since the apparent activation energy for the decomposition of the tablet was 192.5 kJ/mol, in comparison to 154.5 kJ/mol for the pure API.
Curcumin-Loaded Solid Lipid Nanoparticles Bypass P-Glycoprotein Mediated Doxorubicin Resistance in Triple Negative Breast Cancer Cells
Authors: Fathy Abd-Ellatef Gamal-Eldein , Gazzano Elena , Chirio Daniela , Ragab Hamed Ahmed , Belisario Dimas Carolina , Zuddas Carlo , Peira Elena , Rolando Barbara , Kopecka Joanna , Assem Said Marie Mohamed , Sapino Simona , Ramadan Fahmy Sohair , Gallarate Marina , Zaki Abdel-Hamid Abdel-Hamid , Riganti Chiara
Published: January 2020

Multidrug resistance (MDR) is a critical hindrance to the success of cancer chemotherapy. The main thing responsible for MDR phenotypes are plasma-membranes associated with adenosine triphosphate (ATP) Binding Cassette (ABC) drug efflux transporters, such as the P-glycoprotein (Pgp) transporter that has the broadest spectrum of substrates. Curcumin (CURC) is a Pgp inhibitor, but it is poorly soluble and bioavailable. To overcome these limitations, we validated the efficacy and safety of CURC, loaded in biocompatible solid lipid nanoparticles (SLNs), with or without chitosan coating, with the goal of increasing the stability, homogeneous water dispersibility, and cellular uptake. Both CURC-loaded SLNs were 5–10-fold more effective than free CURC in increasing the intracellular retention and toxicity of doxorubicin in Pgp-expressing triple negative breast cancer (TNBC). The effect was due to the decrease of intracellular reactive oxygen species, consequent inhibition of the Akt/IKKα-β/NF-kB axis, and reduced transcriptional activation of the Pgp promoter by p65/p50 NF-kB. CURC-loaded SLNs also effectively rescued the sensitivity to doxorubicin against drug-resistant TNBC tumors, without signs of systemic toxicity. These results suggest that the combination therapy, based on CURC-loaded SLNs and doxorubicin, is an effective and safe approach to overcome the Pgp-mediated chemoresistance in TNBC.
Transgenesis as a Tool for the Efficient Production of Selected Secondary Metabolites from Plant in Vitro Cultures
Authors: Kowalczyk Tomasz , Wieczfinska Joanna , Skała Ewa , Śliwiński Tomasz , Sitarek Przemysław
Published: January 2020

The plant kingdom abounds in countless species with potential medical uses. Many of them contain valuable secondary metabolites belonging to different classes and demonstrating anticancer, anti-inflammatory, antioxidant, antimicrobial or antidiabetic properties. Many of these metabolites, e.g., paclitaxel, vinblastine, betulinic acid, chlorogenic acid or ferrulic acid, have potential applications in medicine. Additionally, these compounds have many therapeutic and health-promoting properties. The growing demand for these plant secondary metabolites forces the use of new green biotechnology tools to create new, more productive in vitro transgenic plant cultures. These procedures have yielded many promising results, and transgenic cultures have been found to be safe, efficient and cost-effective sources of valuable secondary metabolites for medicine and industry. This review focuses on the use of various in vitro plant culture systems for the production of secondary metabolites.
Macrophomina Crown and Root Rot of Pistachio in California
Authors: Nouri Mohamed T. , Lawrence Daniel P. , Kallsen Craig E. , Trouillas Florent P.
Published: January 2020

In this study, declining pistachio rootstocks were detected in newly planted commercial pistachio orchards in Kern County, California. Symptoms were characterized by wilted foliage combined with crown rot in the rootstock. From diseased trees, 42 isolates were obtained, and all had similar cultural and morphological characteristics of Macrophomina phaseolina. Analyses of nucleotide sequences of three gene fragments, the internal transcribed spacer region (ITS1–5.8S–ITS2), partial sequences of β-tubulin, and translation elongation factor 1-α (TEF1) confirmed this identification, and 20 representative isolates are presented in the phylogenetic study. Testing of Koch’s postulates showed that M. phaseolina, when inoculated to stems and roots of the pistachio rootstocks using mycelial plugs or a microsclerotial suspension, is indeed pathogenic to this host. The widely used clonal University of California Berkeley I (UCBI) rootstock appeared highly susceptible to M. phaseolina, suggesting that this pathogen is an emerging threat to the production of pistachio in California. This study confirmed the association of M. phaseolina with the decline of pistachio trees and represents the first description of this fungus as a crown rot-causing agent of pistachio in California.
Is Pasture Cropping a Valid Weed Management Tool?
Authors: Luna Ignacio M. , Fernández-Quintanilla César , Dorado José
Published: January 2020

The aim of the present work was to study the feasibility of pasture cropping under the Mediterranean conditions prevailing in central Spain and its potential as a weed management tool. Three cropping systems were assessed: conventionally grown winter barley and winter barley in pasture cropping with two perennial summer species, Cynodon dactylon and Eragrostis curvula. The results showed that the growth of these two species in a pasture cropping system was limited by the severe drought conditions and high temperatures present during the summer in some of the study years. Although there were no differences in the establishment of winter barley in any of the treatments assessed, pasture cropping reduced winter barley yields up to 50%–60% in years with low rainfall in spring. Regarding weed control, pasture cropping showed a significant suppression of the total weed density and number of weed species. As a conclusion, pasture cropping can be considered as a valid weed management tool. However, the economic feasibility of this system under the climatic conditions of central Spain (characterized by a high risk of severe summer droughts) is still not clear. The availability of supplemental irrigation may reduce competition between pastures and winter crops and ensure a profitable production of summer pastures.
Invasive Mesquite (Prosopis juliflora), an Allergy and Health Challenge
Authors: Hussain M. Iftikhar , Shackleton Ross T. , El-Keblawy Ali , Del Mar Trigo Pérez María , González Luís
Published: January 2020

Mesquite (Prosopis juliflora (Sw.) DC), is an medium-sized tree (family Fabaceae, subfamily Mimosoideae), that has been intorcuded around the world. It is a noxious invasive species in Africa, Asia, and the Arabian Peninsula and a source of highly allergenic pollen in. The present article reviews the adverse allergenic effects of P. juliflora pollen on human and animal health. Several studies have diagnosed that allergenic pollens from Prosopis spp. can provoke respiratory problems. Prosopis pollen extracts have 16 allergenic components of which nine proteins were recognized as major allergens with some of them showing cross-reactivity. Clinically, understanding Prosopis pollen production, flowering seasonality, pollen load, and dispersal in the atmosphere are important to avoid allergic consequences for local inhabitants. Climate change and other pollution can also help to further facilitate allergenic issues. Furthermore, we document other human and animal health problems caused by invasive Prosopis trees. This includes flesh injuries, dental and gastric problems, and the facilitation of malaria. This review summarizes and enhances the existing knowledge about Prosopis flowering phenology, aeroallergen, and other human and animal health risks associated with this noxious plant.
Variation in Root and Shoot Growth in Response to Reduced Nitrogen
Authors: Tolley Seth , Mohammadi Mohsen
Published: January 2020

Recently, root traits have been suggested to play an important role in developing greater nitrogen uptake and grain yield. However, relatively few breeding programs utilize these root traits. Over a series of experiments at different growth stages with destructive plant biomass measurements, we analyzed above-ground and below-ground traits in seven geographically diverse lines of wheat. Root and shoot biomass allocation in 14-day-old seedlings were analyzed using paper roll-supported hydroponic culture in two Hoagland solutions containing 0.5 (low) and 4 (high) mM of nitrogen (N). For biomass analysis of plants at maturity, plants were grown in 7.5 L pots filled with soil mix under two nitrogen treatments. Traits were measured as plants reached maturity. High correlations were observed among duration of vegetative growth, tiller number, shoot dry matter, and root dry matter. Functionality of large roots in nitrogen uptake was dependent on the availability of N. Under high N, lines with larger roots had a greater yield response to the increase in N input. Under low N, yields were independent of root size and dry matter, meaning that there was not a negative tradeoff to the allocation of more resources to roots, though small rooted lines were more competitive with regards to grain yield and grain N concentration in the low-N treatment. In the high-N treatment, the large-rooted lines were correlated to an increase in grain N concentration (r = 0.54) and grain yield (r = 0.43). In low N, the correlation between root dry matter to yield (r = 0.20) and grain N concentration (r = −0.38) decreased. A 15-fold change was observed between lines for root dry matter; however, only a ~5-fold change was observed in shoot dry matter. Additionally, root dry matter measured at the seedling stage did not correlate to the corresponding trait at maturity. As such, in a third assay, below-ground and above-ground traits were measured at key growth stages including the four-leaf stage, stem elongation, heading, post-anthesis, and maturity. We found that root growth appears to be stagnant from stem elongation to maturity.
Plant Aspartic Proteases for Industrial Applications: Thistle Get Better
Authors: Folgado André , Abranches Rita
Published: January 2020

Plant proteases have a number of applications in industrial processes including cheese manufacturing. The flower of the cardoon plant (Cynara cardunculus L.) is traditionally used as a milk-clotting agent in protected designation of origin cheeses made from goat and sheep milk. Plant-derived rennets are of particular importance to consumers who wish to eat cheeses that are produced without harming any animals. In this review, we have highlighted the importance of plant proteases, particularly aspartic proteases, in industrial processes, as well as exploring more fundamental aspects of their synthesis. We have also reviewed and discussed the production of these enzymes using sustainable and cost-effective alternative platforms.
Elucidating the Possible Involvement of Maize Aquaporins and Arbuscular Mycorrhizal Symbiosis in the Plant Ammonium and Urea Transport under Drought Stress Conditions
Authors: Quiroga Gabriela , Erice Gorka , Aroca Ricardo , Delgado-Huertas Antonio , Ruiz-Lozano Juan Manuel
Published: January 2020

This study investigates the possible involvement of maize aquaporins which are regulated by arbuscular mycorrhizae (AM) in the transport in planta of ammonium and/or urea under well-watered and drought stress conditions. The study also aims to better understand the implication of the AM symbiosis in the uptake of urea and ammonium and its effect on plant physiology and performance under drought stress conditions. AM and non-AM maize plants were cultivated under three levels of urea or ammonium fertilization (0, 3 µM or 10 mM) and subjected or not to drought stress. Plant aquaporins and physiological responses to these treatments were analyzed. AM increased plant biomass in absence of N fertilization or under low urea/ ammonium fertilization, but no effect of the AM symbiosis was observed under high N supply. This effect was associated with reduced oxidative damage to lipids and increased N accumulation in plant tissues. High N fertilization with either ammonium or urea enhanced net photosynthesis (AN) and stomatal conductance (gs) in plants maintained under well-watered conditions, but 14 days after drought stress imposition these parameters declined in AM plants fertilized with high N doses. The aquaporin ZmTIP1;1 was up-regulated by both urea and ammonium and could be transporting these two N forms in planta. The differential regulation of ZmTIP4;1 and ZmPIP2;4 with urea fertilization and of ZmPIP2;4 with NH4+ supply suggests that these two aquaporins may also play a role in N mobilization in planta. At the same time, these aquaporins were also differentially regulated by the AM symbiosis, suggesting a possible role in the AM-mediated plant N homeostasis that deserves future studies.
Extracts of Common Pesticidal Plants Increase Plant Growth and Yield in Common Bean Plants
Authors: Mkindi Angela G. , Tembo Yolice L. B. , Mbega Ernest R. , Smith Amy K. , Farrell Iain W. , Ndakidemi Patrick A. , Stevenson Philip C. , Belmain Steven R.
Published: January 2020

Common bean (Phaseolus vulgaris) is an important food and cash crop in many countries. Bean crop yields in sub-Saharan Africa are on average 50% lower than the global average, which is largely due to severe problems with pests and diseases as well as poor soil fertility exacerbated by low-input smallholder production systems. Recent on-farm research in eastern Africa has shown that commonly available plants with pesticidal properties can successfully manage arthropod pests. However, reducing common bean yield gaps still requires further sustainable solutions to other crop provisioning services such as soil fertility and plant nutrition. Smallholder farmers using pesticidal plants have claimed that the application of pesticidal plant extracts boosts plant growth, potentially through working as a foliar fertiliser. Thus, the aims of the research presented here were to determine whether plant growth and yield could be enhanced and which metabolic processes were induced through the application of plant extracts commonly used for pest control in eastern Africa. Extracts from Tephrosia vogelii and Tithonia diversifolia were prepared at a concentration of 10% w/v and applied to potted bean plants in a pest-free screen house as foliar sprays as well as directly to the soil around bean plants to evaluate their contribution to growth, yield and potential changes in primary or secondary metabolites. Outcomes of this study showed that the plant extracts significantly increased chlorophyll content, the number of pods per plant and overall seed yield. Other increases in metabolites were observed, including of rutin, phenylalanine and tryptophan. The plant extracts had a similar effect to a commercially available foliar fertiliser whilst the application as a foliar spray was better than applying the extract to the soil. These results suggest that pesticidal plant extracts can help overcome multiple limitations in crop provisioning services, enhancing plant nutrition in addition to their established uses for crop pest management.
Molecular Events Involved in Fruitlet Abscission in Litchi
Authors: Zhao Minglei , Li Jianguo
Published: January 2020

Abscission in plants is an active and highly coordinated physiological process in which organs abscise from the plant body at the abscission zone (AZ) in responding to either developmental or environmental cues. Litchi (Litchi chinensis Sonn.) is an important economic fruit crop widely grown in Southeast Asia particularly in South China. However, the excessive fruit drop during fruit development is a major limiting factor for litchi production. Thus, it is an important agricultural concern to understand the mechanisms underlying the fruit abscission in litchi. Here, we present a review focusing on the molecular events involved in the fruitlet abscission. We also highlight the recent advances on genes specifically associated with fruit abscission and perspectives for future research.
Fatigue Life Estimation with Mean Stress Effect Compensation for Lightweight Structures—The Case of GLARE 2 Composite
Authors: Böhm Michał , Głowacka Karolina
Published: January 2020

This paper describes the current state-of-the-art in fatigue life assessment for lightweight composite structures with the use of the frequency domain fatigue life calculation method. Random stationary gaussian loading signals have been generated and served in the process of fatigue calculation. The material information that is being used in the calculation process has been obtained from literature for the Glare 2 composite. The effect of nonzero mean stress and different fiber orientations have been taken into account. The calculations have been performed for two mean stress compensation models by Goodman and Gerber. The proposed procedure gives satisfying results for the high-cycle fatigue region for Goodman and an overall good comparison in both regimes for the Gerber model.
Semiflexible Polymers Interacting with Planar Surfaces: Weak versus Strong Adsorption
Authors: Milchev Andrey , Binder Kurt
Published: January 2020

Semiflexible polymers bound to planar substrates by a short-range surface potential are studied by Molecular Dynamics simulations to clarify the extent to which these chain molecules can be considered as strictly two-dimensional. Applying a coarse-grained bead-spring model, the chain length N and stiffness κ as well as the strength of the adsorption potential ϵ w a l l are varied over a wide range. The excluded-volume (EV) interactions inherent in this model can also be “switched off” to provide a discretized version of the Kratky–Porod wormlike chain model. We study both local order parameters (fraction f of monomers within the range of the potential, bond-orientational order parameter η ) and the mean square gyration radius parallel, ⟨ R g 2 ⟩ | | , and perpendicular, ⟨ R g 2 ⟩ ⊥ , to the wall. While for strongly adsorbed chains EV has negligible effect on f and η , we find that ⟨ R g 2 ⟩ | | is strongly affected when the chain contour length exceeds the persistence length. Monomer coordinates in perpendicular (⊥) direction are correlated over the scale of the deflection length which is estimated. It is found that f , η , and ⟨ R g 2 ⟩ ⊥ converge to their asymptotic values with 1 / N corrections. For both weakly and strongly adsorbed chains, the distribution functions of “loops”, “trains”, and “tails” are analyzed. Some consequences pertaining to the analysis of experiments on adsorbed semiflexible polymers are pointed out.
Synthesis and Properties of Thermosets from Tung Oil and Furfuryl Methacrylate
Authors: Sain Sunanda , Åkesson Dan , Skrifvars Mikael
Published: January 2020

This work focuses on the development of cross-linked polymer from a highly unsaturated vegetable oil, tung oil (TO) and a bio-based acrylate, furfuryl methacrylate (FMA). The presence of a high degree of unsaturated carbon-carbon bonding in TO makes it a suitable precursor for polymer synthesis. Using this advantage of TO, in this work, we have synthesised a cross-linked polymer from TO and FMA through free radical polymerisation followed by Diels–Alder (DA) reaction. Successful incorporation of both of the raw materials and the two chemical reactions was shown using Fourier-transform infrared (FTIR) and Raman spectroscopy. The development of cross-linked structure was analysed through thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA).
Base Promoted Intumescence of Phenols
Authors: Ji Yu , Yao Qiang , Cao Weihong , Zhao Yueying
Published: January 2020

The intumescent process of sodium (substituted) phenolates has been studied. The generation of hydrogen radical via a homolytic cleavage of the Ar–H bond and the subsequent hydroarylation of phenolates to cyclohexadienes along with cyclization and elimination reactions of cyclohexadienes are critical steps in the base promoted intumescence of phenols. The substituents show great influence on the intumescence of phenolates. Phenolates substituted with a weak electron donating group enable intumescence while those with an electron withdrawing group or strong electron donating group suppresses intumescence. This distinction can be justified by both electronic and steric effects of substituents on the generation of hydrogen radical and the degree of hydroarylation.
Flexural Creep Behavior of High-Density Polyethylene Lumber and Wood Plastic Composite Lumber Made from Thermally Modified Wood
Authors: Alrubaie Murtada Abass A. , Lopez-Anido Roberto A. , Gardner Douglas J.
Published: January 2020

The use of wood plastic composite lumber as a structural member material in marine applications is challenging due to the tendency of wood plastic composites (WPCs) to creep and absorb water. A novel patent-pending WPC formulation that combines a thermally modified wood flour (as a cellulosic material) and a high strength styrenic copolymer (high impact polystyrene and styrene maleic anhydride) have been developed with advantageous viscoelastic properties (low initial creep compliance and creep rate) compared with the conventional WPCs. In this study, the creep behavior of the WPC and high-density polyethylene (HDPE) lumber in flexure was characterized and compared. Three sample groupings of WPC and HDPE lumber were subjected to three levels of creep stress; 7.5, 15, and 30% of the ultimate flexural strength (Fb) for a duration of 180 days. Because of the relatively low initial creep compliance of the WPC specimens (five times less) compared with the initial creep compliance of HDPE specimens, the creep deformation of HDPE specimens was six times higher than the creep deformation of WPC specimens at the 30% creep stress level. A Power Law model predicted that the strain (3%) to failure in the HDPE lumber would occur in 1.5 years at 30% Fb flexural stress while the predicted strain (1%) failure for the WPC lumber would occur in 150 years. The findings of this study suggest using the WPC lumber in structural application to replace the HDPE lumber in flexure attributable to the low time-dependent deformation when the applied stress value is withing the linear region of the stress-strain relationship.
Mass Spectral Fragmentation of Pelargonium graveolens Essential Oil Using GC–MS Semi-Empirical Calculations and Biological Potential
Authors: S. M. Abd El-Kareem Mamoun , A. Rabbih Mohamed , Elansary Hosam O. , A. Al-Mana Fahed
Published: January 2020

The volatile constituents of the essential oil of local Pelargonium graveolens growing in Egypt was investigated by gas chromatography–mass spectrometry (GC–MS), and the main constituents were citronellol (27.67%), cis-Menthone (10.23%), linalool (10.05%), eudesmol (9.40%), geraniol formate 6.87%, and rose oxide (5.77%), which represent the major components in the obtained GC total ion chromatogram. The structural determination of the main constitutes based on their electron ionization mass spectra have been investigated. The MS of these compounds are absolutely identical in mass values of peaks of fragment ions, where their relative intensities have minor differences. In the spectra of all studied compounds, the observed characteristic ions were [M-H2O]+ and [M-CH3]+. The latter has a structure with m/z 69, 83. Different quantum parameters were obtained using Modified Neglect of Diatomic Overlap (MNDO) semi-empirical method as total energy, binding energy, heat of formations, ionization energy, the energy of highest occupied molecular orbital (HOMO), the energy of the lowest unoccupied molecular orbital (LUMO), energy gap Δ, and dipole moment. The antibacterial and antifungal activities of P. graveolens essential oil and identified compounds were tested against wide collection of organisms. The individual identified compounds in the essential oil—citronellol, cis-Menthone, and linalool (except eudesmol)—showed comparable activity to antibiotics. The most active isolated compound was the citronellol and the lowest MIC was found against E. coli. The essential oil showed high antifungal effects and this activity was attributed to cis-Menthone, eudesmol, and citronellol (excluding linalool). cis-Menthone was the most active compound against selected fungi followed by the eudesmol The study recommends local P. graveolens and identified active compounds for further applications in the pharmaceutical industries.
H2S Removal with Sorbent Obtained from Sewage Sludges
Authors: Papurello Davide , Lanzini Andrea , Bressan Maurizio , Santarelli Massimo
Published: January 2020

Biochar obtained from sewage sludges are adopted for biogas cleaning. Sewage sludges are treated considering temperature, dwell time, activating agent, heating, and flow rate. The best performances achieved are registered considering the char produced at 400 °C using CO2 as an activating agent with a dwell time of 2 h. The adsorption capacity for the biogas cleaning CH4/CO2/H2S (20 ppm(v)) increased from 1.3 mg/g to 5.9 mg/g with the bed height. Future research with chemical activation processes will be made to improve the adsorption capacity achieved to produce cheaper sorbents than commercial ones.
Pipeline Neighbors: How Can We Avoid Conflicts?
Authors: Novikova Natalya
Published: January 2020

In this article, I consider the various policies of oil and gas companies relating to Indigenous peoples of the Russian Federation. The analysis is based on field research in Northern Russian regions. Data for the analysis comprises: International standards, Russian laws, corporate codes, official regulations, and interviews with company employees and representatives of the Indigenous populations. The research methodology is based on the concept of legal pluralism as the coexistence of various legal regimes and the search for platforms of common interests. The goal of this article is to analyze policies on benefit sharing by assessing projects and programs adopted by various industrial companies according to the social and humanitarian prospects of their social acceptance. I consider the possibilities for Russian legislation to promote respecting Indigenous people’s interests in the preparation of corporate sustainability reports.
Using High Resolution Optical Imagery to Detect Earthquake-Induced Liquefaction: The 2011 Christchurch Earthquake
Authors: Rashidian Vahid , Baise Laurie , Koch Magaly
Published: January 2020

Using automated supervised methods with satellite and aerial imageries for liquefaction mapping is a promising step in providing detailed and region-scale maps of liquefaction extent immediately after an earthquake. The accuracy of these methods depends on the quantity and quality of training samples and the number of available spectral bands. Digitizing a large number of high-quality training samples from an event may not be feasible in the desired timeframe for rapid response as the training pixels for each class should be typical and accurately represent the spectral diversity of that specific class. To perform automated classification for liquefaction detection, we need to understand how to build the optimal and accurate training dataset. Using multispectral optical imagery from the 22 February, 2011 Christchurch earthquake, we investigate the effects of quantity of high-quality training pixel samples as well as the number of spectral bands on the performance of a pixel-based parametric supervised maximum likelihood classifier for liquefaction detection. We find that the liquefaction surface effects are bimodal in terms of spectral signature and therefore, should be classified as either wet liquefaction or dry liquefaction. This is due to the difference in water content between these two modes. Using 5-fold cross-validation method, we evaluate performance of the classifier on datasets with different pixel sizes of 50, 100, 500, 2000, and 4000. Also, the effect of adding spectral information was investigated by adding once only the near infrared (NIR) band to the visible red, green, and blue (RGB) bands and the other time using all available 8 spectral bands of the World-View 2 satellite imagery. We find that the classifier has high accuracies (75%–95%) when using the 2000 pixels-size dataset that includes the RGB+NIR spectral bands and therefore, increasing to 4000 pixels-size dataset and/or eight spectral bands may not be worth the required time and cost. We also investigate accuracies of the classifier when using aerial imagery with same number of training pixels and either RGB or RGB+NIR bands and find that the classifier accuracies are higher when using satellite imagery with same number of training pixels and spectral information. The classifier identifies dry liquefaction with higher user accuracy than wet liquefaction across all evaluated scenarios. To improve classification performance for wet liquefaction detection, we also investigate adding geospatial information of building footprints to improve classification performance. We find that using a building footprint mask to remove them from the classification process, increases wet liquefaction user accuracy by roughly 10%.