1,327 research outputs found
Contributos para o estudo da arquitectura cisterciense, em Portugal, no âmbito do Projecto ORFEUS: forma e música
Abstract
This communication reflects the work done in the Department of Civil Engineering and Architecture at the University of Beira Interior (Portugal), and still ongoing, in the framework of the project ORFEUS - The Tridentine Reform and music in the cloistral silence: the Monastery of S. Bento de Cástris (Project FCT EXPL/EPH-PAT/2253/2013) and aims to bring the debate to a contribution to the study of the specificity of the monastery of St. Bento de Cástris in the context of Cistercian architecture, in which the shape and the music are intertwined.
In this way, two dissertations have been developed in Architecture (integrated master course of architecture of the University of Beira Interior) within the project ORFEUS, which are divided by the importance and contributions of the Cistercian Architecture in contemporary religious architecture, the morphology of the Cistercian churches and the relationship between architecture and music in the specific case study of the church of the monastery of St. Bento de Cástris.
Resumo
Esta comunicação reflecte o trabalho desenvolvido no Departamento de Engenharia Civil e Arquitectura da Universidade da Beira Interior, e ainda em curso, no âmbito do Projecto ORFEUS - A Reforma tridentina e a música no silêncio claustral: o mosteiro de S. Bento de Cástris (Projecto FCT EXPL/EPH- PAT/2253/2013) e pretende-se com esta comunicação trazer a debate um contributo para o estudo da especificidade do Mosteiro de S. Bento de Cástris, no contexto da arquitectura cisterciense, no qual a forma e a música se entrelaçam. Neste sentido foram desenvolvidas duas dissertações de mestrado integrado em Arquitectura, no âmbito do Projecto ORFEUS, que se repartem pela importância e contributos da Arquitectura Cisterciense na Arquitectura religiosa contemporânea, a morfologia das igrejas cistercienses e a relação entre a arquitectura e música patente no estudo de caso da igreja do Mosteiro de S. Bento de Cástris
Floating TiO2-Cork Nano-Photocatalysts for Water Purification Using Sunlight
Funding Information: This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling, and Nanofabrication—i3N, but also the UI/BD/151292/2021 (Ph.D. research scholarship). The work was also partially funded by the Nanomark collaborative project between INCM (Imprensa Nacional—Casa da Moeda) and CENIMAT/i3N. Acknowledgments also go to the EC project SYNERGY H2020-WIDESPREAD-2020-5, CSA, proposal nº 952169, EMERGE-2020-INFRAIA-2020-1, proposal nº 101008701, and to the European Community’s H2020 program under grant agreement No. 787410 (ERC-2018-AdG DIGISMART). Publisher Copyright: © 2022 by the authors.In the present study, titanium dioxide (TiO2) nano-photocatalysts were synthesized through microwave irradiation. In a typical microwave synthesis, TiO2 nanomaterials were simultaneously produced in powder form and also directly covering cork substrates. The TiO2 nanopowder was analyzed by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM), revealing that the solvothermal microwave synthesis resulted only in the TiO2 anatase phase. From Fourier-transform infrared spectroscopy (FTIR), cork’s organic species, along with bands of TiO2, were detected. UV–VIS absorption spectrum revealed an absorption extension to the visible region, since a brown powdered TiO2 product was obtained. Very fine nanoparticles were observed displaying a nearly spherical shape that agglomerates in larger particles. These larger particles fully covered the surface of the honeycomb cork cells, originating TiO2 functionalized cork platforms. The TiO2 functionalized substrates were further tested as floating photocatalysts and their photocatalytic activity was assessed from rhodamine B degradation under solar simulating light and natural sunlight. Reusability tests were also performed under natural sunlight. The strategy applied in this research work allowed the production of green and low-cost cork platforms based on TiO2 photoactive materials with the ability to purify polluted water under natural sunlight.publishersversionpublishe
Microwave Synthesis of Visible-Light-Activated g-C3N4/TiO2 Photocatalysts
Funding Information: This work was financed by national funds from FCT-Fundação para a Ciência e a Tecnologia, I.P., within the scope of projects UI/BD/151292/2021 (Ph.D. research scholarship), LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling, and Nanofabrication-i3N, but also the 2021.03825.CEECIND. Acknowledgments are also given to the EC project SYNERGY H2020-WIDESPREAD-2020-5, CSA, proposal nº 952169, EMERGE-2020-INFRAIA-2020-1, proposal nº 101008701, and to the European Community’s H2020 program under grant agreement No. 787410 (ERC-2018-AdG DIGISMART). Publisher Copyright: © 2023 by the authors.The preparation of visible-light-driven photocatalysts has become highly appealing for environmental remediation through simple, fast and green chemical methods. The current study reports the synthesis and characterization of graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) heterostructures through a fast (1 h) and simple microwave-assisted approach. Different g-C3N4 amounts mixed with TiO2 (15, 30 and 45 wt. %) were investigated for the photocatalytic degradation of a recalcitrant azo dye (methyl orange (MO)) under solar simulating light. X-ray diffraction (XRD) revealed the anatase TiO2 phase for the pure material and all heterostructures produced. Scanning electron microscopy (SEM) showed that by increasing the amount of g-C3N4 in the synthesis, large TiO2 aggregates composed of irregularly shaped particles were disintegrated and resulted in smaller ones, composing a film that covered the g-C3N4 nanosheets. Scanning transmission electron microscopy (STEM) analyses confirmed the existence of an effective interface between a g-C3N4 nanosheet and a TiO2 nanocrystal. X-ray photoelectron spectroscopy (XPS) evidenced no chemical alterations to both g-C3N4 and TiO2 at the heterostructure. The visible-light absorption shift was indicated by the red shift in the absorption onset through the ultraviolet-visible (UV-VIS) absorption spectra. The 30 wt. % of g-C3N4/TiO2 heterostructure showed the best photocatalytic performance, with a MO dye degradation of 85% in 4 h, corresponding to an enhanced efficiency of almost 2 and 10 times greater than that of pure TiO2 and g-C3N4 nanosheets, respectively. Superoxide radical species were found to be the most active radical species in the MO photodegradation process. The creation of a type-II heterostructure is highly suggested due to the negligible participation of hydroxyl radical species in the photodegradation process. The superior photocatalytic activity was attributed to the synergy of g-C3N4 and TiO2 materials.publishersversionpublishe
High Trypanosoma spp. diversity is maintained by bats and triatomines in Espírito Santo state, Brazil
The aim of this study was to reevaluate the ecology of an area in the Atlantic Forest, southeast Brazil, where Chagas disease (CD) has been found to occur. In a previous study, immediately after the occurrence of a CD case, we did not observe any sylvatic small mammals or dogs with Trypanosoma cruzi cruzi infections, but Triatoma vitticeps presented high T. c. cruzi infection rates. In this study, we investigated bats together with non-volant mammals, dogs, and triatomines to explore other possible T. c. cruzi reservoirs/hosts in the area. Seventy-three non-volant mammals and 186 bats were captured at three sites within the Guarapari municipality, Espírito Santo state. Rio da Prata and Amarelos sites exhibited greater richness in terms of non-volant mammals and bats species, respectively. The marsupial Metachirus nudicaudatus, the rodent Trinomys paratus, and the bats Artibeus lituratus and Carollia perspicillata were the most frequently captured species. As determined by positive hemocultures, only two non-volant mammals were found to be infected by Trypanosoma species: Monodelphis americana, which was infected by T. cascavelli, T. dionisii and Trypanosoma sp., and Callithrix geoffroyi, which was infected by T. minasense. Bats presented T. c. cruzi TcI and TcIII/V, T. c. marinkellei, T. dionisii, T. rangeli B and D, and Trypanosoma sp. infections. Seven dogs were infected with T. cruzi based only on serological exams. The triatomines T. vitticeps and Panstrongylus geniculatus were found to be infected by trypanosomes via microscopy. According to molecular characterization, T. vitticeps specimens were infected with T. c. cruzi TcI, TcII, TcIII/V, and TcIV, T. c. marinkellei and T. dionisii. We observed high trypanosome diversity in a small and fragmented region of the Atlantic Forest. This diversity was primarily maintained by bats and T. vitticeps. Our findings show that the host specificity of the Trypanosoma genus should be thoroughly reviewed. In addition, our data show that CD cases can occur without an enzootic cycle near residential areas
Effects of residues on the degradation of PHA produced from mixed microbial cultures and processed in extrusion
Thermal degradation upon melting is one of the major drawbacks reported for polyhydroxyalkanoates (PHA). However, the role of residues originating from the fermentation and the extraction steps on the thermal stability of this class of biopolymers still needs to be clarified. In the particular case of PHA produced from mixed microbial cultures (MMC), this topic is even less documented in the literature. Here, two polyhydroxy(butyrate-co-valerate) (PHBV) produced from MMC enriched in PHA accumulating organisms and fed with cheese whey were studied. A micro extrusion line is used to produce filaments and assess the processability and the degradation of processed PHBV. The prototype micro extrusion line allows for studying grams of materials. The two PHBV contain 18 mol% HV. PHBV was recovered with 11 wt% residues, and further submitted to a purification procedure resulting in a second biopolyester containing less than 2 wt% impurities. The thermorheological characterization of the two PHBV is first presented, together with their semicrystalline properties. Then the processing windows of the two biopolyesters are presented. Finally, the properties of extruded filaments are reported and the thermomechanical degradation of PHBV is extensively studied. The structure was assessed by wide angle X-ray diffraction, mechanical and rheological properties are reported, thermal properties are studied with differential scanning calorimetry and thermogravimetric analysis, whereas Fourier Transform Infrared spectroscopy was used to assess the impact of the extrusion on PHBV chemical structure. All results obtained with the two PHBV are compared to assess the effects of residues on both PHBV processability and degradation
Assessing the in Vitro Toxicity of Airborne (Nano)Particles to the Human Respiratory System: From Basic to Advanced Models [Review]
[Abstract] Several studies have been conducted to address the potential adverse health risks attributed to exposure to nanoscale materials. While in vivo studies are fundamental for identifying the relationship between dose and occurrence of adverse effects, in vitro model systems provide important information regarding the mechanism(s) of action at the molecular level. With a special focus on exposure to inhaled (nano)particulate material toxicity assessment, this review provides an overview of the available human respiratory models and exposure systems for in vitro testing, advantages, limitations, and existing investigations using models of different complexity. A brief overview of the human respiratory system, pathway and fate of inhaled (nano)particles is also presented.The work was supported by the Fundação para a Ciência e a Tecnologia [POCI-01-0145-FEDER-029651, SFRH/BPD/122112/2016,PTDC/MED‐TOX/31162/2017, DL-57/INSA-06/2018,SFRH/BD/101060/2014,SFRH/BD/120646/2016,SIINN/0004/2014,UIDB/04750/2020, LA/P/0064/2020]; Spanish Ministry of Education, Culture and Sport [BEAGAL18/00142]; Spanish Ministry of Science and Innovation [PID2020-114908GA-I00]Portugal. Fundação para a Ciência e a Tecnologia; POCI-01-0145-FEDER-029651Portugal. Fundação para a Ciência e a Tecnologia; SFRH/BPD/122112/2016Portugal. Fundação para a Ciência e a Tecnologia; PTDC/MED‐TOX/31162/2017Portugal. Fundação para a Ciência e a Tecnologia; DL-57/INSA-06/2018Portugal. Fundação para a Ciência e a Tecnologia; SFRH/BD/101060/2014Portugal. Fundação para a Ciência e a Tecnologia; SFRH/BD/120646/2016Portugal. Fundação para a Ciência e a Tecnologia; SIINN/0004/2014Portugal. Fundação para a Ciência e a Tecnologia; UIDB/04750/2020Portugal. Fundação para a Ciência e a Tecnologia; LA/P/0064/202
Novel and revisited approaches in nanoparticle systems for buccal drug delivery
The buccal route is considered patient friendly due to its non-invasive nature and ease of administration. Such delivery route has been used as an alternative for the delivery of drugs that undergo first-pass metabolism or are susceptible to pH and enzymatic degradation, such as occurs in the gastrointestinal tract. However, the drug concentration absorbed in the buccal mucosa is often low to obtain an acceptable therapeutic effect, mainly due to the saliva turnover, tongue and masticatory movements, phonation, enzymatic degradation and lack of epithelium permeation. Therefore, the encapsulation of drugs into nanoparticles is an important strategy to avoid such problems and improve their buccal delivery. Different materials from lipids to natural or synthetic polymers and others have been used to protect and deliver drugs in a sustained, controlled or targeted manner, and enhance their uptake through the buccal mucosa improving their bioavailability and therapeutic outcome. Overall, the main aim of this review is to perform an overview about the nanotechnological approaches developed so far to improve the buccal delivery of drugs. Herein, several types of nanoparticles and delivery strategies are addressed, and a special focus on pipeline products is also given.info:eu-repo/semantics/acceptedVersio
Assessment of solar driven TiO2-assisted photocatalysis efficiency on amoxicillin degradation
The objective of this work was to evaluate the efficiency of a solar TiO2-assisted photocatalytic process on amoxicillin (AMX) degradation, an antibiotic widely used in human and veterinary medicine. Firstly, solar photolysis of AMX was compared with solar photocatalysis in a compound parabolic collectors pilot scale photoreactor to assess the amount of accumulated UV energy in the system (Q (UV)) necessary to remove 20 mg L-1 AMX from aqueous solution and mineralize the intermediary by-products. Another experiment was also carried out to accurately follow the antibacterial activity against Escherichia coli DSM 1103 and Staphylococcus aureus DSM 1104 and mineralization of AMX by tracing the contents of dissolved organic carbon (DOC), low molecular weight carboxylate anions, and inorganic anions. Finally, the influence of individual inorganic ions on AMX photocatalytic degradation efficiency and the involvement of some reactive oxygen species were also assessed. Photolysis was shown to be completely ineffective, while only 3.1 kJ(UV) L-1 was sufficient to fully degrade 20 mg L-1 AMX and remove 61 % of initial DOC content in the presence of the photocatalyst and sunlight. In the experiment with an initial AMX concentration of 40 mg L-1, antibacterial activity of the solution was considerably reduced after elimination of AMX to levels below the respective detection limit. After 11.7 kJ(UV) L-1, DOC decreased by 71 %; 30 % of the AMX nitrogen was converted into ammonium and all sulfur compounds were converted into sulfate. A large percentage of the remaining DOC was in the form of low molecular weight carboxylic acids. Presence of phosphate ions promoted the removal of AMX from solution, while no sizeable effects on the kinetics were found for other inorganic ions. Although the AMX degradation was mainly attributed to hydroxyl radicals, singlet oxygen also plays an important role in AMX self-photosensitization under UV/visible solar light
Molecular characterization of Giardia lamblia in children less than 5 years of age with diarrhoea attending the Bengo General Hospital, Angola
Introduction - Giardia lamblia is a pathogenic intestinal protozoan with high prevalence in developing countries, especially among children. Molecular characterization has revealed the existence of eight assemblages, with A and B being more commonly described in human infections. Despite its importance, to our knowledge, this is the first published molecular analysis of G. lamblia assemblages in Angola. Methods - The present study aimed to identify the assemblages of G. lamblia in children with acute diarrhoea presenting at the Bengo General Hospital, Angola. A stool sample was collected and microscopy and immunochromatographic tests were used. DNA was extracted and assemblage determination was performed through amplification of the gene fragment ssu-rRNA (175 bp) and β-giardin (511 bp) through polymerase chain reaction and DNA sequencing. Results - Of the 16 stool samples screened, 12 were successfully sequenced. Eleven isolates were assigned to assemblage B and one to assemblage A. Subassemblage determination was not possible for assemblage B, while the single isolate assigned to assemblage A was identified as belonging to subassemblage A3.
Conclusion - This study provides information about G. lamblia assemblages in Bengo Province, Angola and may contribute as a first step in understanding the molecular epidemiology of this protozoan in the country. GenBank accession numbers for the ssur-RNA gene: MF479750, MF479751, MF479752, MF479753, MF479754, MF479755, MF479756, MF479757, MF479758, MF479759, MF479760, MF479761. GenBank accession numbers for the β-giardin gene: MF565378, MF565379, MF565380, MF565381.info:eu-repo/semantics/publishedVersio
Polymyxin-Resistant Acinetobacter spp. Isolates: What is Next?
Univ Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Div Infect Dis, Lab Especial Microbiol Clin, BR-04025010 Sao Paulo, SP, BrazilWeb of Scienc
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