Search results for "Class"
showing 10 items of 38174 documents
Pulicaria glutinosa Extract: A Toolbox to Synthesize Highly Reduced Graphene Oxide-Silver Nanocomposites
2015
A green, one-step approach for the preparation of graphene/Ag nanocomposites (PE-HRG-Ag) via simultaneous reduction of both graphene oxide (GRO) and silver ions using Pulicaria glutinosa plant extract (PE) as reducing agent is reported. The plant extract functionalizes the surfaces of highly reduced graphene oxide (HRG) which helps in conjugating the Ag NPs to HRG. Increasing amounts of Ag precursor enhanced the density of Ag nanoparticles (NPs) on HRG. The preparation of PE-HRG-Ag nanocomposite is monitored by using ultraviolet-visible (UV-Vis) spectroscopy, powder X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The as-prepared PE-HRG-Ag nanocomposities display excellent surfac…
New Data on the Silver Objects from the House of Eupolemos (Morgantina, Sicily)
2015
Due to their intrinsic value, ancient silver objects have often arrived at museums throughout the world with provenance other than that of regular excavations, and therefore much data regarding the context and the production process in the workshops of origin, as well as the circulation of such objects, is missing. The discovery of silver objects, in fact, is derived from what one may define as non-productive hoarding – archaeological collections created through the formal burial or the furtive hiding in a moment of danger of objects that were never recovered – circumstances that limit the possibility of knowing the primary use of the object in antiquity, in the manner that we can determine…
Synthesis and characterization of Zwitterionic Zn(II) and Cu(II) coordination compounds with ring-substituted 2,2′-biimidazole derivatives
2016
Zwitterionic coordination compounds with strongly asymmetrical charge distribution were synthesized and characterized. Ring-substituted biimidazoles were used as the primary ligands for Zn and Cu compounds. Formation of Zwitterionic coordination compound was found to be strongly dependent on the pH of the reaction medium as well as on the ring and nitrogen substituents of the ligand. Reaction of the Df-R2biim (Df-R2biim = 2,2′-bi-1R-imidazole-5,5′-dicarboxaldehyde, R = Me, Et or Pr) with ZnCl2 in neutral conditions led to binuclear compounds [Zn2Cl4(Df-R2biim)2] with two bridging ligands (1a–c). Reaction with CuCl2·2H2O gave neutral mononuclear compound [CuCl2(Df-Me2biim)] (1d) with chelati…
Los sistemas alternativos y aumentativos de comunicación (SAAC) como instrumento para disminuir conductas desafiantes en el alumnado con TEA: estudio…
2017
Resumen Se describe una intervención, basada en el Programa de Habla Signada de Benson Schaeffer, para dotar de un Sistema Alternativo y Aumentativo de Comunicación (SAAC) a una niña de ocho años diagnosticada con trastorno del espectro autista (TEA). Se pretende que la alumna, mediante la utilización de signos, pueda expresar sus necesidades y disminuir las conductas desafiantes que propicia, ya que se estima que estas tienen una clara intención comunicativa. Se utiliza una metodología cualitativa de estudio de caso único y por objetivos. El programa se desarrolló en el aula de comunicación y lenguaje (CyL) de un centro público de educación infantil y primaria (CEIP) de la Comunidad Valenc…
Advantages of Hyaluronic Acid and Its Combination with Other Bioactive Ingredients in Cosmeceuticals
2021
This study proposes a review on hyaluronic acid (HA) known as hyaluronan or hyaluronate and its derivates and their application in cosmetic formulations. HA is a glycosaminoglycan constituted from two disaccharides (N-acetylglucosamine and D-glucuronic acid), isolated initially from the vitreous humour of the eye, and subsequently discovered in different tissues or fluids (especially in the articular cartilage and the synovial fluid). It is ubiquitous in vertebrates, including humans, and it is involved in diverse biological processes, such as cell differentiation, embryological development, inflammation, wound healing, etc. HA has many qualities that recommend it over other substances used…
Alleviating Class Imbalance Problem in Automatic Sleep Stage Classification
2022
For real-world automatic sleep-stage classification tasks, various existing deep learning-based models are biased toward the majority with a high proportion. Because of the unique sleep structure, most of the current polysomnography (PSG) datasets suffer an inherent class imbalance problem (CIP), in which the number of each sleep stage is severely unequal. In this study, we first define the class imbalance factor (CIF) to describe the level of CIP quantitatively. Afterward, we propose two balancing methods to alleviate this problem from the dataset quantity and the relationship between the class distribution and the applied model, respectively. The first one is to employ the data augmentati…
Partially disarticulated new Miocene burrower bug (Hemiptera: Heteroptera: Cydnidae) from Cerová (Slovakia) documents occasional preservation of terr…
2015
The state of preservation of the bug Sehirus carpathiensis J.A. Lis, Vršanský & Schlögl, sp. n. (Hemiptera: Heteroptera: Cydnidae) from the Lakšárska Nová Ves Formation at Cerová (Slovakia) supports extremely rapid sinking and burial in upper bathyal Early Miocene sediments. The specimen originated from land at most a few kilometers away, but transport via a river can be excluded as the head and wings are still attached. Its most likely source based on fossil flora and the habitat of several living representatives of the genus is a riparian habitat in an adjacent area of land. Phylogenetically the new species is closely related to both Oligocene and living representatives of the genus, thus…
Low‐Valent Germanylidene Anions: Efficient Single‐Site Nucleophiles for Activation of Small Molecules
2021
Abstract Rare mononuclear and helical chain low‐valent germanylidene anions supported by cyclic (alkyl)(amino)carbene and hypermetallyl ligands were synthesised by stepwise reduction from corresponding germylene precursors via stable and isolable germanium radicals. The electronic structures of the anions can be described with ylidene and ylidone resonance forms with the Ge−C π‐electrons capable of binding even weak electrophiles. The germanylidene anions reacted with CO2 to give μ‐CO2‐κC:κO complexes, a rare coordination mode for low‐valent germanium and inaccessible for the related neutral germylones. These results implicate low‐valent germanylidene anions as efficient single‐site nucleop…
Aristóteles entre doxografía y biografía: sobre Diógenes Laercio V 31
2019
Se pretende llamar la atención sobre un par de frases que aparecen justo hacia la mitad de la controvertida doxografía de Aristóteles que se puede leer en las Vidas y doctrinas de los filósofos más ilustres de Diógenes Laercio V 31, y que desde luego no corresponden a ningún sistema doxográfico conocido. Como sucede no pocas veces en la obra laerciana, la misma apreciación sobre si el filósofo debe o no enamorarse y contraer matrimonio se repite idéntica en otras doxografías completamente distintas: la cirenaica (DL II 91), la estoica (DL VII 129) y la epicúrea (DL X 118). Cabe plantearse, pues, el origen de este interés, en varias doxografías, por la vida sentimental, podríamos decir, de l…
Le choix des parrains et marraines dans les campagnes finlandaises entre 1810 et 1914
2015
On the basis of two case studies of artisans from the Finnish countryside, this paper presents five major factors that affected normal godparent relations. It argues that in some cases (especially among the highest echelons of the local society) godparenting strategies aiming at social advancement, which have received much attention in the research, may have had some significance, but for the majority of the population locality, occupation, social class and kinship were more important factors. In fact, most of these were highly intertwined in the pre-modern Finnish society of estates, and this is very visible in godparent networks. Thus this paper will serve researchers of godparenthood as …