Electromagnetic wave absorption and structural properties of wide-band absorber made of graphene-printed glass-fibre composite

Lightweight composites combining electromagnetic wave absorption and excellent mechanical properties are required in spacecraft and aircraft. A one- dimensional metamaterial absorber consisting of a stack of glass fibre/epoxy layers and graphene nanoplatelets/epoxy films was proposed and fabricated through a facile air-spraying based printing technology and a liquid resin infusion method. The production process allows an optimum dispersion of graphene nanoplatelets, promoting adhesion and mechanical integration of the glass fibre/epoxy layers with the graphene nanoplatelets/epoxy films. According to experimental results, the proposed wide-band absorber provides a reflection coefficient lower than −10 dB in the range 8.5–16.7 GHz and an improvement of flexural modulus of more than 15%, with a total thickness of ∼1 mm. Outstanding electromagnetic wave absorption and mechanical performance make the proposed absorber more competitive in aeronautical and aerospace applications

Autotrophic and Heterotrophic Growth Conditions Modify Biomolecole Production in the Microalga Galdieria sulphuraria (Cyanidiophyceae, Rhodophyta)

Algae have multiple similarities with fungi, with both belonging to the Thallophyte, a polyphyletic group of non-mobile organisms grouped together on the basis of similar characteristics, but not sharing a common ancestor. The main difference between algae and fungi is noted in their metabolism. In fact, although algae have chlorophyll-bearing thalloids and are autotrophic organisms, fungi lack chlorophyll and are heterotrophic, not able to synthesize their own nutrients. However, our studies have shown that the extremophilic microalga Galderia sulphuraria (GS) can also grow very well in heterotrophic conditions like fungi. This study was carried out using several approaches such as scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC/MS), and infrared spectrophotometry (ATR-FTIR). Results showed that the GS, strain ACUF 064, cultured in autotrophic (AGS) and heterotrophic (HGS) conditions, produced different biomolecules. In particular, when grown in HGS, the algae (i) was 30% larger, with an increase in carbon mass that was 20% greater than AGS; (ii) produced higher quantities of stearic acid, oleic acid, monounsaturated fatty acids (MUFAs), and ergosterol; (iii) produced lower quantities of fatty acid methyl esters (FAMEs) such as methyl palmytate, and methyl linoleate, saturated fatty acids (SFAs), and poyliunsaturated fatty acids (PUFAs). ATR-FTIR and principal component analysis (PCA) statistical analysis confirmed that the macromolecular content of HGS was significantly different from AGS. The ability to produce different macromolecules by changing the trophic conditions may represent an interesting strategy to induce microalgae to produce different biomolecules that can find applications in several fields such as food, feed, nutraceutical, or energy production

Orthodontic management of a mandibular double-tooth incisor: A case report

The presence of a double-tooth requires specific complex management due to the need for differential diagnosis and following treatment choices. The aim of this report was to present a rare case of a geminated mandibular lateral incisor, treated with an orthodontic approach. A Caucasian 10.9-year-old girl presented a lower right double-tooth incisor, with a class 1 molar and a class 2 cuspid tendency on both sides. The upper arch was constricted as shown by bilaterally tendencies to cross-bite, a slightly lower midline deviation was reported and a lack of space for all four permanent cuspids was confirmed also by the panoramic X-ray. In the lower arch, there was a severe crowding of about 14 mm and a buccally ectopic left canine. Overbite was normal and Overjet minimally increased. The double-tooth was identified like a geminated tooth, for the presence of one root and one pulp canal of increased size, as shown by the radiographic examinations. The anomalous tooth was managed with an orthodontic approach associated with a progressive stripping to reshape the crown. A two-phase treatment plan was performed, based on first maxillary expansion and lip bumper and then fixed appliances, in order to achieve a proper occlusion and a better aesthetic

The Surprising Story of Fusicoccin: A Wilt-Inducing Phytotoxin, a Tool in Plant Physiology and a 14-3-3-Targeted Drug

Fusicoccin is the alpha glucoside of a carbotricyclic diterpene, produced by the fungus Phomopsis amygdali (previously classified as Fusicoccum amygdali), the causal agent of almond and peach canker disease. A great interest in this molecule started when it was discovered that it brought about an irreversible stomata opening of higher plants, thereby inducing the wilting of their leaves. Since then, several studies were carried out to elucidate its biological activity, biosynthesis, structure, structure-activity relationships and mode of action. After sixty years of research and more than 1800 published articles, FC is still the most studied phytotoxin and one of the few whose mechanism of action has been elucidated in detail. The ability of FC to stimulate several fundamental plant processes depends on its ability to activate the plasma membrane H+-ATPase, induced by eliciting the association of 14-3-3 proteins, a class of regulatory molecules widespread in eukaryotes. This discovery renewed interest in FC and prompted more recent studies aimed to ascertain the ability of the toxin to influence the interaction between 14-3-3 proteins and their numerous client proteins in animals, involved in the regulation of basic cellular processes and in the etiology of different diseases, including cancer. This review covers the different aspects of FC research partially treated in different previous reviews, starting from its discovery in 1964, with the aim to outline the extraordinary pathway which led this very uncommon diterpenoid to evolve from a phytotoxin into a tool in plant physiology and eventually into a 14-3-3-targeted drug

Reinforcement-matrix interactions and their consequences on the mechanical behavior of basalt fibers-cement composites

In order to prepare basalt fibers-reinforced cement-based mortars with higher compatibility between reinforcement and matrix, basalt fibers with new surface treatments (sizing) were studied looking for enhanced interaction at the interphase between basalt fibers and cement matrix. As-received, calcinated, activated and silanized (by three silane aqueous solutions: i) aminopropyltriethoxysilane, APTES; ii) ¿-aminopropylmethyldiethoxysilane, APDES and iii) a mixture APTES APDES 50% by weight) basalt fibers were dispersed in Portland cement matrix. Performances of the composites were evaluated by mechanical tests. Final correlation between the fibers surface characteristics and mechanical performance was carried out considering the induced microstructural changes and adhesion at the interface. Fractographic analysis by SEM and laser and optical profilometry were performed. A clear improvement in mechanical properties was obtained when basalt fibers were dispersed in cement matrix. Results suggest that better behavior is achieved when basalt fibers modified with a complex mixture of silanes are dispersed in cement matrix.This work was financially supported by the Projects MAT2014-59116-C2 (Ministerio de Economía y Competitividad); 2012/00130/004 (Fondos de Investigación de Fco. Javier GonzalezBenito, política de reinversión de costes generales, Universidad Carlos III de Madrid) and 2011/00287/002 (Acción Estratégica en Materiales Compuestos Poliméricos e Interfases, Universidad Carlos III de Madrid). The research was financially supported also by the Project Bando per il Finanzia- mento di Progetti di Ricerca Congiunti per la Mobilit`a all Estero di Studenti di Dottorato prot. n 0051266 (Universit`a degli Studi di Roma, La Sapienza) in the frame the PhD Thesis of Morena Iorio. Finally, the authors would like to thank the group In-service Material Performance (Universidad Carlos III de Madrid) for supporting the project in the mechanical tests

How to capture wild passerine species to study baseline corticosterone levels

Baseline corticosterone levels have been suggested to be an effective tool to assess and monitor the health status of individuals and populations of wild birds. However, measuring baseline corticosterone levels in the field is difficult because the capture protocol may affect rates of corticosterone secretion. In passerine birds, two methods of capture are widely used: (1) passive netting consisting of monitoring mist-nets frequently to check if a bird has been caught; and (2) target netting consisting of installing a conspecific decoy and/or playing a tape-recorded conspecific song in the vicinity of a mist-net until the territorial bird is captured. Our objective here was to determine whether these methods of capture are effective at achieving non-disturbed baseline corticosterone levels in American Redstarts (Setophaga ruticilla). We found that passive netting was associated with elevated corticosterone levels, suggesting that hanging in a net for several minutes activates the HPA axis and, thus, elicits an adreno-cortical stress response. In contrast, target netting was not associated with an increase in corticosterone levels, regardless of the length of time between when the target bird first approached the net and when it was captured. Therefore, we suggest that researchers interested in estimated baseline corticosterone in this species use target netting and not passive netting

Debris flows in the eastern Italian Alps: seasonality and atmospheric circulation patterns

Abstract. The work examines the seasonality and large-scale atmospheric circulation patterns associated with debris-flow occurrence in the Trentino–Alto Adige region (eastern Italian Alps). Analysis is based on classification algorithms applied to a uniquely dense archive of debris flows and hourly rain gauge precipitation series covering the period 2000–2009. Results highlight the seasonal and synoptic forcing patterns linked to debris flows in the study area. Summer and fall season account for 92% of the debris flows in the record, while atmospheric circulation characterized by zonal west, mixed and meridional south and southeast (SE–S) patterns account for 80%. Both seasonal and circulation patterns exhibit geographical preference. In the case of seasonality, there is a strong north–south separation of summer–fall dominance, while spatial distribution of dominant circulation patterns exhibits clustering, with both zonal west and mixed patterns prevailing in the northwest and central east part of the region, while the southern part relates to meridional south and southeast pattern. Seasonal and synoptic pattern dependence is pronounced also on the debris-flow-triggering rainfall properties. Examination of rainfall intensity–duration thresholds derived for different data classes (according to season and synoptic pattern) revealed a distinct variability in estimated thresholds. These findings imply a certain control on debris-flow events and can therefore be used to improve existing alert systems