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31.
Francesca Mocci Chiara Olla Antonio Cappai Riccardo Corpino Pier Carlo Ricci Daniele Chiriu Marcello Salis Carlo Maria Carbonaro 《Materials》2021,14(4)
The molecular model is one of the most appealing to explain the peculiar optical properties of Carbon nanodots (CNDs) and was proven to be successful for the bottom up synthesis, where a few molecules were recognized. Among the others, citrazinic acid is relevant for the synthesis of citric acid-based CNDs. Here we report a combined experimental and computational approach to discuss the formation of different protonated and deprotonated species of citrazinic acid and their contribution to vibrational and magnetic spectra. By computing the free energy formation in water solution, we selected the most favoured species and we retrieved their presence in the experimental surface enhanced Raman spectra. As well, the chemical shifts are discussed in terms of tautomers and rotamers of most favoured species. The expected formation of protonated and de-protonated citrazinic acid ions under extreme pH conditions was proven by evaluating specific interactions with H2SO4 and NaOH molecules. The reported results confirm that the presence of citrazinic acid and its ionic forms should be considered in the interpretation of the spectroscopic features of CNDs. 相似文献
32.
In this paper, various graphite oxide (GO) and reduced graphene oxide (rGO) preparation methods are analyzed. The obtained materials differed in their properties, including (among others) their oxygen contents. The chemical and structural properties of graphite, graphite oxides, and reduced graphene oxides were previously investigated using Raman spectroscopy (RS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). In this paper, hierarchical clustering analysis (HCA) and analysis of variance (ANOVA) were used to trace the directions of changes of the selected parameters relative to a preparation method of such oxides. We showed that the oxidation methods affected the physicochemical properties of the final products. The aim of the research was the statistical analysis of the selected properties in order to use this information to design graphene oxide materials with properties relevant for specific applications (i.e., in gas sensors). 相似文献
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Manuel Toledano Fátima S. Aguilera Salvatore Sauro Inmaculada Cabello Estrella Osorio Raquel Osorio 《Dental materials》2014
Objectives
The purpose of this study was to evaluate if mechanical loading promotes bioactivity at the resin interface after bonding with three different adhesive approaches.Methods
Dentin surfaces were subjected to three different treatments: demineralisation by (1) 37% phosphoric acid (PA) followed by application of an etch-and-rinse dentin adhesive Single Bond (SB) (PA + SB), (2) by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA + SB), (3) application of a self-etch dentin adhesive: Clearfil SE Bond (SEB). Bonded interfaces were stored in simulated body fluid during 24 h or 3 w. One half of each tooth was submitted to mechanical loading. Remineralisation of the bonded interfaces was assessed by AFM imaging/nano-indentation, Raman spectroscopy/cluster analysis, dye assisted confocal microscopy evaluation (CLSM) and Masson's trichrome staining.Results
Loading cycling for 3 w promoted an increase of mechanical properties at the resin–dentin interface. Cluster analysis demonstrated an augmentation of the mineral–matrix ratio in SB-loaded specimens. CLSM showed an absent micropermeability and nanoleakage after loading EDTA + SB and SEB specimens. Trichrome staining reflected a narrow demineralised dentin matrix after loading, almost not observable in EDTA + SB and SEB.Significance
In vitro mechanical loading promoted mineralization in the resin–dentin interfaces, at 24 h and 3 w of storage. 相似文献36.
Dipankar Das Kasturi Bhattacharjee Manab J Barman Harsha Bhattacharjee Surjendu Maity Dipankar Bandyopadhyay Siddharth Thakur Saurabh Deshmukh Mohit Garg Apurba Deka 《Indian journal of ophthalmology》2021,69(12):3612
Purpose:The aim of this study was to examine the pathology of retinoblastoma (RB) seeds with supportive evidence by field emission scanning electron microscopy and Raman spectroscopy.Methods:This study was a laboratory-based observational study. Enucleated eyeballs received in the ocular pathology department of a tertiary eye care center in northeast India were included in the cohort after obtaining written informed consent during the surgery. The study was carried out for 6 years (2015–2020). Most of the eyeballs were Group-E RBs. Standard eyeballs sectioning were done by bread loaf techniques. Gross documentations included RB seeds seen in the smallest calotte done with utmost care. Seeds were documented also in permanent sections. Scanning electron microscopy and Raman spectroscopy were carried out in an index case.Results:Out of the total 59 cases, 35 RB cases had different seedings. The mean age at enucleation was 2.9 years. RB seeds were seen in vitreous (n = 19), subretinal plus vitreous (n = 7), anterior chamber (n = 1), over crystalline lens (n = 3), retinal surface (n = 1), retinal pigment epithelium (RPE; n = 2), subretinal (n = 1), calcified seeds (n = 2). Other characteristics were dusts (n = 7), clouds (n = 11), spheres (n = 4), and unspecified type (n = 13). Histopathological high-risk factors showed significant choroidal (n = 22) and optic nerve (n = 15) involvement. Few cases had extraocular spread. Undifferentiated tumor (n = 24) was seen with higher evidence of necrosis (n = 23). Raman spectra differentiated the seeds from the normal tissue on the basis of lipid and protein content.Conclusion:This study highlights the different types of RB seeds with high-risk factors. The morphology of those seeds showed the difference between vitreous and subretinal seeds under advanced microscopic observations. 相似文献
37.
Katherine Ember Franois Daoust Myriam Mahfoud Frdrick Dallaire Esmat Zamani Ahmad Trang Tran Arthur Plante Mame-Kany Diop Tien Nguyen Amlie St-Georges-Robillard Nassim Ksantini Julie Lanthier Antoine Filiatrault Guillaume Sheehy Gabriel Beaudoin Caroline Quach Dominique Trudel Frdric Leblond 《Journal of biomedical optics》2022,27(2)
38.
Sebastiano Ettore Spoto Giuseppe Paladini Francesco Caridi Vincenza Crupi Sebastiano DAmico Domenico Majolino Valentina Venuti 《Materials》2022,15(3)
Plasters and mortars of the Church of the Annunciation (Tortorici, Sicily) were characterized, for the first time, both at the elemental and molecular levels, by means of portable X-ray fluorescence (XRF) and Raman spectroscopy, to achieve information on the “state of health” of the whole structure. The understanding of their degradation mechanisms and the identification of consequent degradation patterns can define the environmental factors responsible for interpreting the potential pathological forms that can impact the general building vulnerability. In this sense, the results obtained in this article provide relevant information to identify and address both the characterization of building materials and the fundamental causes of their deterioration. At the same time, if coupled with the attempt to supply a chronological order of the major restoration interventions carried out on the investigated site, they provide new insights to calibrate the models for building vulnerability studies. 相似文献
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