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1.
Vitamins are organic compounds that are required for various biological functions. In general, vitamins are not synthesized in the human body, but lack or deficiency of them may lead to certain diseases. Determinations of 11 vitamins in various products were performed, which included ascorbic acid (C), seven vitamins of the B group (thiamine B1, riboflavin B2, nicotinamide B3, pantothenic acid B5, pyridoxine B6, folic acid B9, and cyanocobalamin B12), as well as three fat-soluble vitamins (retinol A, cholecalciferol D3, and α-tocopherol E). A column with RP18 stationary phase and a diode array detector with properly selected analytical wavelengths for each compound were used. A gradient of trifluoroacetic acid in water with methanol was used as the mobile phase. Limits of quantification in the range of 0.70–2.90 μg/mL for water-soluble vitamins and 1.85–15.84 μg/mL for fat-soluble vitamins were obtained. Those values are sufficient for determinations of the aforementioned compounds in foodstuff. The developed procedure of sample preparation together with chromatographic system can be used for food quality monitoring in the food industry. 相似文献
2.
Dr. Tommaso Felicetti Prof. Giuseppe Manfroni Prof. Violetta Cecchetti Dr. Rolando Cannalire 《ChemMedChem》2020,15(24):2391-2419
Infections by flaviviruses, such as Dengue, West Nile, Yellow Fever and Zika viruses, represent a growing risk for global health. There are vaccines only for few flaviviruses while no effective treatments are available. Flaviviruses share epidemiological, structural, and ecologic features and often different viruses can co-infect the same host. Therefore, the identification of broad-spectrum inhibitors is highly desirable either for known flaviviruses or for viruses that likely will emerge in the future. Strategies targeting both virus and host factors have been pursued to identify broad-spectrum antiflaviviral agents. In this review, we describe the most promising and best characterized targets and their relative broad-spectrum inhibitors, identified by drug repurposing/libraries screenings and by focused medicinal chemistry campaigns. Finally, we discuss about future strategies to identify new broad-spectrum antiflavivirus agents. 相似文献
3.
Abstract. For linear processes, semiparametric estimation of the memory parameter, based on the log‐periodogram and local Whittle estimators, has been exhaustively examined and their properties well established. However, except for some specific cases, little is known about the estimation of the memory parameter for nonlinear processes. The purpose of this paper is to provide the general conditions under which the local Whittle estimator of the memory parameter of a stationary process is consistent and to examine its rate of convergence. We show that these conditions are satisfied for linear processes and a wide class of nonlinear models, among others, signal plus noise processes, nonlinear transforms of a Gaussian process ξt and exponential generalized autoregressive, conditionally heteroscedastic (EGARCH) models. Special cases where the estimator satisfies the central limit theorem are discussed. The finite‐sample performance of the estimator is investigated in a small Monte Carlo study. 相似文献
4.
Violetta Hionidou 《Food and Foodways: Explorations in the History and Culture of》2013,21(2-3):81-106
This article deals with the operation of markets during the famine and food crisis that occurred in occupied Greece in the period 1941–1944. Among other factors, the division of the country into three zones of occupation between which no movements of goods and people was allowed and the failed attempt by the government to control prices and production led to the collapse of the normal markets and the gradual but firm establishment of a black market. In the later years of the occupation, and in association with a rampant inflation, the black market was extremely volatile and heavily dependent on “shocks.” Even though the occupation governments, the press, the resistance, and post-war academics fiercely condemned the black market, oral evidence shows that virtually everyone was involved in some way in its dealings. 相似文献
5.
Androula Galiouna Nassiopoulou Violetta Gianneta Charalambos Katsogridakis 《Nanoscale research letters》2011,6(1):597
In this paper, we investigate the formation kinetics of Si nanowires [SiNWs] on lithographically defined areas using a single-step metal-assisted chemical etching process in an aqueous HF/AgNO3 solution. We show that the etch rate of Si, and consequently, the SiNW length, is much higher on the lithographically defined areas compared with that on the non-patterned areas. A comparative study of the etch rate in the two cases under the same experimental conditions showed that this effect is much more pronounced at the beginning of the etching process. Moreover, it was found that in both cases, the nanowire formation rate is linear with temperature in the range from 20°C to 50°C, with almost the same activation energy, as obtained from an Arrhenius plot (0.37 eV in the case of non-patterned areas, while 0.38 eV in the case of lithographically patterned areas). The higher etch rate on lithographically defined areas is mainly attributed to Si surface modification during the photolithographic process.PACS: 68; 68.65-k. 相似文献
6.
Natalia Schiefermeier-Mach Violetta Moresco Stephan Geley Lea Heinrich Lukas Lechner Heidi Oberhauser Susanne Perkhofer 《International journal of molecular sciences》2021,22(11)
Inhaled Aspergillus fumigatus spores can be internalized by alveolar type II cells. Cell lines stably expressing fluorescently labeled components of endocytic pathway enable investigations of intracellular organization during conidia internalization and measurement of the process kinetics. The goal of this report was to evaluate the methodological appliance of cell lines for studying fungal conidia internalization. We have generated A549 cell lines stably expressing fluorescently labeled actin (LifeAct-mRuby2) and late endosomal protein (LAMP1-NeonGreen) following an evaluation of cell-pathogen interactions in live and fixed cells. Our data show that the LAMP1-NeonGreen cell line can be used to visualize conidia co-localization with LAMP1 in live and fixed cells. However, caution is necessary when using LifeAct-mRuby2-cell lines as it may affect the conidia internalization dynamics. 相似文献
7.
Bartosz Tylkowski Krzysztof A Bogdanowicz Veronica Ambrogi Albena Lederer Violetta Patroniak Marta Giamberini 《Polymer International》2014,63(2):315-326
A liquid crystal polyester and two liquid crystal copolyesters containing α‐methylstilbene moieties and aliphatic or aromatic spacers in the backbone were synthesized in good yields, with the aim of using them for photosensitive microcapsule preparation. The synthesized polymers were fully characterized with respect to thermal stability, type of mesophase, molecular weight and E–Z photoisomerization. Combination of monomers with different structures allowed adjustment of the polymer characteristics such as degree of crystallinity and glass transition temperature, as verified using X‐ray diffraction, polarized optical microscopy and differential scanning calorimetry. Quantitative 1H NMR and UV‐visible experiments were performed in order to investigate E–Z photoisomerization after photoirradiation at 364 nm. Finally, a membrane based on one of these polymers was prepared and it was found that its wettability increased on photoirradiation. © 2013 Society of Chemical Industry 相似文献
8.
This article deals with the operation of markets during the famine and food crisis that occurred in occupied Greece in the period 1941-1944. Among other factors, the division of the country into three zones of occupation between which no movements of goods and people was allowed and the failed attempt by the government to control prices and production led to the collapse of the normal markets and the gradual but firm establishment of a black market. In the later years of the occupation, and in association with a rampant inflation, the black market was extremely volatile and heavily dependent on “shocks.” Even though the occupation governments, the press, the resistance, and post-war academics fiercely condemned the black market, oral evidence shows that virtually everyone was involved in some way in its dealings. 相似文献
9.
Milo Hricovíni Raymond J. Owens Andrzej Bak Violetta Kozik Witold Musia Roberta Pierattelli Magdalna Mjekov Yoel Rodríguez Robert Musio Aneta Slodek Pavel tarha Karina Pitak Dagmara Sota Wioletta Florkiewicz Agnieszka Sobczak-Kupiec Josef Jampílek 《International journal of molecular sciences》2022,23(23)
The knowledge of interactions between different molecules is undoubtedly the driving force of all contemporary biomedical and biological sciences. Chemical biology/biological chemistry has become an important multidisciplinary bridge connecting the perspectives of chemistry and biology to the study of small molecules/peptidomimetics and their interactions in biological systems. Advances in structural biology research, in particular linking atomic structure to molecular properties and cellular context, are essential for the sophisticated design of new medicines that exhibit a high degree of druggability and very importantly, druglikeness. The authors of this contribution are outstanding scientists in the field who provided a brief overview of their work, which is arranged from in silico investigation through the characterization of interactions of compounds with biomolecules to bioactive materials. 相似文献
10.
Angeliki Droutsa Nikolaos Emmanouil Konstantinos Raptopoulos Antonio Salvaggio Veronica Mazzei Roberta Pecoraro Giuseppina Messina Chiara Copat Margherita Ferrante Maria Violetta Brundo Bianca Maria Lombardo 《Microscopy research and technique》2019,82(6):651-657
In the last years, the increase of anthropogenic activities has led to a progressive pollution of ecosystems. Oniscidean isopods are a group of terrestrial animals known as excellent bio‐indicators and bio‐accumulators, because of their capacity to accumulate contaminants and to implement appropriate strategies of detoxification. For this study, we collected Porcellionides pruinosus from two different sites in the Corinth region (Greece), a polluted site and a control site, to assess the heavy metal pollution status. We conducted an inductively coupled plasma mass spectrometry (ICP‐MS) analysis for the detection of trace elements in animals' hepatopancreas and soil; we performed also immunohistochemistry for detection of metallothioneins 1 (MT1) and heat shock protein 70 (HSP70s). The results suggest a great capacity of the species in trace elements bioaccumulation and the high degree of pollution of the area near Agioi Theodoroi where the metal pollution index (MPI) is threefolds higher than the control site, due to the presence of significantly higher concentration of arsenic, cadmium, cobalt, chromium, manganese, molybdenum, and lead found in hepatopancreas and soil. The environmental stress is confirmed by the expression of the relative biomarkers of exposure MT1 and HSP70. Our study, with a multimarker approach, consents getting a complete analysis of environmental quality and the effect of pollution on organisms and shows for the first time the heavy metals contamination status in certain Greece area. Furthermore, P. pruinosus proved to be an appropriate indicator of pollution in terrestrial ecosystems. 相似文献