Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Molecules ; 27(20)2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36296705

RESUMO

In this study, we investigate the hydrothermal liquefaction (HTL) of PET separated from a densified postconsumer plastic mix, with the aim of recovering its monomer. This second raw material is made up of 90% polyolefin, while the remaining 10% is made up of PET, traces of metals, paper, and glass. After preliminary separation by density in water, two batch experiments were performed on the sunken fraction (composed mainly of PET) in a stainless steel autoclave at 345 °C for 30 and 20 min. Both trials resulted in similar yields of the three phases. In particular, the solid yield is around 76% by weight. After a purification step, this phase was analyzed by UV-Vis, 1H-NMR, and FTIR spectroscopy and resulted to be constituted by terephthalic acid (TPA), a product of considerable industrial interest. The study proved that the hydrothermal liquefaction process coupled with density separation in water is effective for obtaining TPA from a densified postconsumer plastic mix, which can be used for new PET synthesis.


Assuntos
Ácidos Ftálicos , Plásticos , Aço Inoxidável , Água/química , Temperatura , Biocombustíveis
2.
Global Health ; 16(1): 47, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32423479

RESUMO

BACKGROUND: After Action Reviews (AAR) with a One Health perspective were performed in Slovenia, Italy, Serbia and Greece following a severe West Nile virus (WNV) transmission season in 2018. A protocol combining traditional techniques and organizational process analysis was developed and then implemented in each country. RESULTS: In 2018, response to the unusually intense transmission season of WNV in Slovenia, Italy, Serbia and Greece took place through routine response mechanisms. None of the four countries declared a national or subnational emergency. We found a very strong consensus on the strengths identified in responding to this event. All countries indicated the availability of One Health Plans for surveillance and response; very high laboratory diagnostic capacity in the human, veterinary and entomology sectors and strong inter-sectoral collaboration with strong commitment of engaged institutions as critical in the management of the event. Finally, countries implementing One Health surveillance for WNV (in terms of early warning and early activation of prevention measures) consistently reported a positive impact on their activities, in particular when combining mosquito and bird surveillance with surveillance of cases in humans and equids. Recurring priority areas for improvement included: increasing knowledge on vector-control measures, ensuring the sustainability of vector monitoring and surveillance, and improving capacity to manage media pressure. CONCLUSIONS: The AARs presented here demonstrate the benefit of cross-sectoral and cross-disciplinary approaches to preparedness for West Nile virus outbreaks in Europe. In the coming years, priorities include fostering and strengthening arrangements that: enable coordinated One Health surveillance and response during WNV transmission seasons; ensure adequate laboratory capacities; strengthen risk communication; and fund longer-term research to address the knowledge gaps identified in this study.


Assuntos
Febre do Nilo Ocidental/epidemiologia , Animais , Culicidae/virologia , Surtos de Doenças , Grécia , Humanos , Itália/epidemiologia , Mosquitos Vetores , Estações do Ano , Sérvia/epidemiologia , Eslovênia/epidemiologia , Vírus do Nilo Ocidental
4.
Waste Manag Res ; 38(2): 213-225, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31409255

RESUMO

Olive pruning residue is largely formed during cultivation, and is usually disposed through open-air combustion directly in the field, but this habit is a possible source of pollution. The pyrolytic conversion of olive pruning residue has been run in a new and very appealing way using microwave as a heating source and different microwave absorbers in a multimode batch reactor. In this way, olive residue is converted into interesting bio-chemical products with a short pyrolysis time, ranging from 15 to 36 min, and with a peak temperature ranging from 450 K to 705 K according to the different microwave absorber. Thus, a very efficient and selective system was realized, which was able to address the process towards the formation of a large amount of bio-char (up to 61.2%) or a high formation of bio-oil (56.2%) and gas (41.7%) with a very low formation of bio-char (2.1%). However, when carbon and iron were used as microwave absorbers, it was possible to obtain an intermediate amount of bio-char (26-30%) and bio-oil (40 wt%). Bio-oils were collected as dark-brown liquids with low viscosity and density. A bio-oil with a low water concentration was obtained using carbon or iron as the microwave absorber. The bio-oils formed in all experiments contained a very large amount of acetic acid, even when NaOH was the microwave absorber. Furthermore, a large amount of aromatics were present in the bio-oil obtained using carbon as the microwave absorber.


Assuntos
Micro-Ondas , Olea , Biocombustíveis , Carvão Vegetal , Temperatura Alta , Óleos de Plantas , Polifenóis , Pirólise , Temperatura
5.
Eur J Mass Spectrom (Chichester) ; 22(4): 199-212, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27882885

RESUMO

A new and simple protocol for quantitative analysis of bio-oils using gas-chromatography/mass spectrometry is suggested. Compounds were identified via their mass spectra, and then unavailable response factors were calculated with respect to diphenyl as the internal standard using a modified method previously suggested for gas chromatography with flame ionization detection. This new protocol was applied to the characterization of bio-oils obtained from the pyrolysis of woods of different sources or using different pyrolysis procedures. This protocol allowed evaluation of the yields of products from poplar pyrolysis (among 50% and 99%), while a reduced amounts of products were identified from the pyrolysis of cellulose (between 46% and 58%). The main product was always acetic acid, but it was formed in very large yields from poplar while lower yields were obtained from cellulose.

6.
Org Biomol Chem ; 13(13): 3988-4001, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25722026

RESUMO

Chemical modifications of the biotin carrier in pretargeted avidin­biotin radionuclide therapy may be of paramount importance for tuning the amount of the radioactivity delivered to cancer cells by labelled biotins. We report here the synthesis of a collection of new synthetic DOTA-constructs bearing two (+)-biotin molecules (bis-biotins), designed for the creation of multimeric Av units (tetramers) bonded to the antibody. All the syntheses were carried out following the solid phase strategy and growing the molecules on a Rink Amide resin. The biotin heads are connected through spacers containing PEG or non-PEG residues. Molecular modelling calculations suggested that the Av cross-linking ability of the bis-biotins depends mainly on the spacers length, with the best results being expected for arms affording distances in the range of 10­25 Å between the biotin carboxylate atoms, in the fully extended conformation. SEC-HPLC MALLS analysis of the products of our Av/bis-biotin reaction mixtures have confirmed this hypothesis. The bis-biotin 16, where the non-PEG linker ensured a distance of 26.7 Å between the biotin moieties, gave about 50% of Av oligomers while the shorter analogue 18 (19.5 Å) afforded 100% of an Av polymer containing about 21 protein units. Remarkably, the solubility of both the bis-biotins, i.e.16 and 18, in aqueous solutions was good and they showed excellent stability against the action of peptidases.


Assuntos
Avidina/química , Biotina/química , Biotina/síntese química , Dimerização , Desenho de Fármacos , Compostos Heterocíclicos com 1 Anel/química , Multimerização Proteica , Estabilidade de Medicamentos , Marcação por Isótopo , Modelos Moleculares , Peso Molecular , Estrutura Quaternária de Proteína , Técnicas de Síntese em Fase Sólida
7.
Anal Bioanal Chem ; 405(2-3): 691-701, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22614707

RESUMO

The chemical analysis of egg-based wall paintings-the mezzo fresco technique-is an interesting topic in the characterisation of organic binders. A revised procedure for a dot-enzyme-linked immunosorbent assay (dot-ELISA) able to detect protein components of egg-based wall paintings is reported. In the new dot-ELISA procedure we succeeded in maximizing the staining colour by adjusting the temperature during the staining reaction. Quantification of the colour intensity by visible reflectance spectroscopy resulted in a straight line plot of protein concentration against reflectance in the wavelength range 380-780 nm. The modified dot-ELISA procedure is proposed as a semi-quantitative analytical method for characterisation of protein binders in egg-based paintings. To evaluate its performance, the method was first applied to standard samples (ovalbumin, whole egg, egg white), then to model specimens, and finally to real samples (Giotto's wall paintings). Moreover, amino acid analysis performed by innovative ultra-performance liquid chromatography was applied both to standards and to model samples and the results were compared with those from the dot-ELISA tests. In particular, after protein hydrolysis (24 h, 114 °C, 6 mol L(-1) HCl) of the samples, amino acid derivatization by use of 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate enabled reproducible analysis of amino acids. This UPLC amino acid analysis was rapid and reproducible and was applied for the first time to egg-based paintings. Because the painting technique involved the use of egg-based tempera on fresh lime-based mortar, the study enabled investigation of the effect of the alkaline environment on egg-protein detection by both methods.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Proteínas do Ovo/química , Ensaio de Imunoadsorção Enzimática/métodos , Pintura/análise , Aminoácidos/análise , Ovos/análise , Pinturas
8.
Health Policy ; 137: 104905, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37716190

RESUMO

Community-based participatory research (CBPR) is one of the most used community engagement frameworks to promote health changes in vulnerable populations. The more a community is engaged, the more a program can impact the social determinants of health. The present study aims to measure the level of engagement reached in randomized controlled trials (RCTs) using CBPR in disadvantaged populations, and to find out the CBPR components that better correlate with a higher level of engagement. A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Embase, Web of Science, MEDLINE, Cochrane and Scopus databases were queried. Engagement level was assessed using the revised version of IAP2 spectrum, ranging from "inform" to "shared leadership" . Fifty-one RCTs were included, belonging to 36 engagement programs. Fourteen CBPR reached the highest level of engagement. According to the multivariate logistic regression, a pre-existing community intervention was associated with a higher engagement level (OR = 10.08; p<0.05). The variable "institutional funding" was perfectly correlated with a higher level of engagement. No correlation was found with income status or type of preventive programs. A history of collaboration seems to influence the effectiveness in involving communities burdened with social inequities, so starting new partnerships remains a public health priority to invest on. A strong potentiality of CBPR was described in engaging disadvantaged communities, addressing social determinants of health. The key findings described above should be taken into account when planning a community engagement intervention, to build up an effective collaborative field between researchers and population.


Assuntos
Pesquisa Participativa Baseada na Comunidade , Promoção da Saúde , Humanos , Populações Vulneráveis , Saúde Pública , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
ACS Omega ; 7(42): 37757-37763, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36312382

RESUMO

Enzymatic digestion is a promising alternative in the upconversion of plastic waste compared to traditional chemical recycling methods, because it warrants the use of milder conditions. However, enzymes are hardly able to penetrate the bulk of the plastic material; thus, a pretreatment is necessary to promote the reaction. In this study we investigate hydrothermal liquefaction as a thermal pretreatment of a commercial polyurethane before performing an enzymatic digestion. The feedstock is a rigid polyurethane foam. The structure and chemical composition of the feedstock were analyzed through FTIR analysis and solid-state 13C NMR. The polyurethane was then subjected to hydrothermal liquefaction using either ultrapure water or KOH as a basic catalyst. Enzymatic digestion was then performed on the organic fraction obtained from both experiments using a lipase extracted from Candida rugosa. The LC-MS analysis of the digests shows an increase in some signal intensities due to the degradation of oligomeric fragments. This new way of recycling allows the recovery of important chemicals such as quinolines and 4,4'-methylenedianiline. With this study we demonstrate that hydrothermal liquefaction coupled with enzymatic digestion is a suitable alternative for handling polyurethane waste.

10.
Sci Rep ; 11(1): 15504, 2021 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-34326440

RESUMO

The hydrothermal liquefaction reactions (HTL) in subcritical conditions of a lignin residue has been studied on a lab scale. The starting material was a lignin rich residue co-produced by an industrial plant situated in Northern Italy producing lignocellulosic bioethanol. The reactions were carried out in batch mode using stainless steel autoclaves. The experiments were under the following operating conditions: two different temperatures (300-350 °C), the presence of basis catalysts (NaOH, and NH4OH) in different concentrations and the presence/absence of capping agent 2,6-bis-(1,1-dimethylethyl)-4-methylphenol (BHT). Lignin residue and reaction products were characterized by analytical and spectroscopic techniques such as CHN-S, TGA, GC-MS, EPR, and 1H-NMR with (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl (T.E.M.P.O.). The addition of BHT did not significantly affect the yield of char which is formed by radical way. Spectroscopic analysis indicated that the level of radicals during the reaction was negligible. Therefore, the results obtained experimentally suggest that the reaction takes place via an ionic route while radical species would play a minor role.

11.
Polymers (Basel) ; 13(22)2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34833265

RESUMO

The influence of a nanodispersion of TiO2 in water (nanoparticle size: 40 nm, polydispersity index: 0.25), brushed on a Paraloid film and subjected to UV-Vis irradiation was evaluated. The TiO2 nanodispersions showed a tendency to reduce the molecular weight of Paraloid due to its photocatalytic properties. FTIR and GPC analyses and SEM images suggested the degradation of the polymer, while chromatic variations of the films were scarcely detected. This study is very remarkable in the perspective of using this material for the removal of polymeric films used in conservation.

12.
Polymers (Basel) ; 12(9)2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32878177

RESUMO

End functionalized polylactides are prepared by ring opening polymerization of L-lactide in the presence of stannous octoate (Sn(Oct)2). Three chromophores, 9H-carbazol-ethanol (CA), 9-fluorenyl-methanol (FM), and 2-(4-(2-chloro-4-nitrophenylazo)-N-ethylphenylamino)ethanol (Disperse Red 13, DR), are for the first time used as co-initiators in the polymerization process. The polymerization reaction is initiated by conventional thermal treatment, but in the case of FM, microwave-assisted polymerization is also carried out. CA and FM absorb and emit in the UV portion of the electromagnetic spectrum, whereas DR absorbs in the visible part. The obtained end-capped polylactides derivatives show the same photophysical properties as the initiator, so they are "macromolecular dyes" (MDs) that can be used "as synthesized" or can be blended with commercial poly(lactic acid) (PLA). The blends of PLA with MDs have ultraviolet-visible (UV-Vis) absorption and fluorescence emission features similar to that of MDs and thermal properties typical of PLA. Finally, migration tests, carried out onto the blends of PLA with MDs and PLA with free chromophores, show that MDs are less released than free chromophores both in solution and in the solid phase.

13.
Waste Manag ; 73: 511-522, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28483368

RESUMO

Microwave Assisted Pyrolysis (MAP) of the plastic fraction of Waste from Electric and Electronic Equipment (WEEE) from end-life computers was run with different absorbers and set-ups in a multimode batch reactor. A large amount of various different liquid fractions (up to 76.6wt%) were formed together with a remarkable reduction of the solid residue (up to 14.2wt%). The liquid fractions were characterized using the following different techniques: FT-IR ATR, 1H NMR and a quantitative GC-MS analysis. The liquid fractions showed low density and viscosity, together with a high concentration of useful chemicals such as styrene (up to 117.7mg/mL), xylenes (up to 25.6mg/mL for p-xylene) whereas halogenated compounds were absent or present in a very low amounts.


Assuntos
Resíduo Eletrônico , Micro-Ondas , Plásticos , Reciclagem , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Infravermelho com Transformada de Fourier , Estireno
14.
Ann Ist Super Sanita ; 54(4): 324-331, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30575569

RESUMO

INTRODUCTION: Italian and Serbian Health authorities performed an in-depth Gap Assessment of the Serbian microbiology system in the function of communicable disease surveillance using a methodology adapted to context and information needs. METHODS: There were two study phases: a capacity based survey and an equipment mapping survey. Invited participants included national health authorities, heads of national reference laboratories and of public/private diagnostic laboratories in Serbia. Findings were analysed preliminarily and identified gaps were discussed, prioritized and validated through two ad hoc workshops involving all concerned institutions. RESULTS: The Gap Assessment was performed between September and December 2017. The overall response rate was 69% for phase one and 74% for phase two. Identified gaps were assessed as highly relevant during the project workshops. DISCUSSION: Gaps and priorities were highlighted, validated, and studied with a suitable level of detail to develop a concrete action-plan. The same methodological approach could be used to monitor progress in Serbia as well as in other EU candidate countries.


Assuntos
Doenças Transmissíveis/epidemiologia , Microbiologia/normas , Notificação de Doenças , Europa (Continente) , Humanos , Microbiologia/organização & administração , Microbiologia/estatística & dados numéricos , Vigilância em Saúde Pública/métodos , Sérvia/epidemiologia , Inquéritos e Questionários
15.
Schizophr Res ; 97(1-3): 1-5, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17851043

RESUMO

In this study, 56 patients affected by schizophreniform disorder (SFD), as their first lifetime mental disorder, were re-evaluated 7.9+/-4.7 yrs (2-17 yrs) after their first hospitalization. At follow-up, schizophrenia (SC) was diagnosed in 25 patients (46%), a mood disorder (MD) in 19 (35%), a non-SC psychotic disorder in 10 (18%) and no disorder in 2 (4%). The evolution towards SC was predicted by the presence of blunted affect (OR: 1.88) and by poor pre-morbid functioning (OR: 1.10) at the index hospitalization. Our data suggest that SFD may represent the first psychotic presentation of different disorders and the evolution towards SC or a MD seems to be influenced by the pre-morbid level of functioning and by the presence of blunted affect.


Assuntos
Transtorno Bipolar/diagnóstico , Transtorno Depressivo Maior/diagnóstico , Transtornos Psicóticos/diagnóstico , Esquizofrenia/diagnóstico , Psicologia do Esquizofrênico , Adolescente , Adulto , Sintomas Afetivos/diagnóstico , Sintomas Afetivos/psicologia , Transtorno Bipolar/psicologia , Escalas de Graduação Psiquiátrica Breve , Comorbidade , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transtornos Psicóticos/psicologia , Fatores de Risco , Ajustamento Social
16.
J Agric Food Chem ; 55(10): 3877-83, 2007 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-17447794

RESUMO

A general synthetic procedure leading to isotopomeric dihydro-2(3H)furanones (gamma-butyrolactones) containing two, four, or six deuterium atoms has been developed. The labeled dihydro-2(3H)furanones were synthesized in quantitative yield from the saturated diacid C4 (succinic) or unsaturated diacids C4 (fumaric, maleic, or acetylendicarboxylic) in the presence of Ru4H4(CO)8(PBu3)4 using a deuterium pressure of 180 bar at 180 degrees C. This methodology was applied to the total synthesis of a hexadeuterated matairesinol lignan: The 3,4-bis[[3-methoxy-4-(phenylmethoxy)phenyl]methyl]dihydro-2(3H)furanone-[7,7',8,8',9',9'-D6] (benzyl-protected matairesinol-D6) was fully characterized.


Assuntos
4-Butirolactona/química , Furanos/síntese química , Marcação por Isótopo/métodos , Lignanas/síntese química , Deutério , Fumaratos/química , Maleatos/química , Rutênio , Ácido Succínico/química
17.
J Pharm Biomed Anal ; 74: 31-8, 2013 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-23245230

RESUMO

Gamma-hydroxybutyric acid (GHB) and its "pro-drugs", gamma-butyrolactone (GBL) and 1,4 butanediol (1,4-BD), are drugs of abuse with depressant effects on the central nervous system. Many analytical methods have been proposed for the quantitative determination of these compounds mainly in biological matrices but only few have been addressed to dietary supplements and foods. Facile synthesis of the GBL and 1,4-BD isotopologues are available by "one pot" Ru-catalyzed homogeneous deuteration of dicarboxylic acids. In this work we propose a new method for determination of GHB, GBL and 1,4-BD in commercially available dietary supplements, based on isotope dilution mass spectrometry (ID-MS). The procedure involves a simple extraction of sample with acidic acetonitrile and direct analysis by GC-ID-MS method without any purification or derivatization. Indeed, the proposed method takes advantage of the complete conversion of GHB (free acid or its salts) to GBL, allowing the quantification of GHB and its pro-drugs. Five levels for each calibration curve have been prepared by diluting working solutions of the analytes to obtain concentrations ranging from 1 to 20mg/mL. The validation procedures have shown an accuracy between 88% and 99% and a precision between 7.3% and 2.9% of each analyte in the sample matrix. Positive ions chemical ionization (PICI) have been employed to preserve the information on molecular ions and to improve specificity and sensitivity of quantitative determination.


Assuntos
4-Butirolactona/análise , Butileno Glicóis/análise , Suplementos Nutricionais/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidroxibutiratos/análise , Pró-Fármacos/análise , 4-Butirolactona/síntese química , Butileno Glicóis/síntese química , Cromatografia Gasosa-Espectrometria de Massas/normas , Hidroxibutiratos/síntese química , Pró-Fármacos/síntese química , Reprodutibilidade dos Testes
18.
Dalton Trans ; 42(7): 2495-501, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23212285

RESUMO

The selective formic acid dehydrogenation to a mixture of CO(2) and H(2) was achieved with moderate to good productivities in the presence of homogeneous Ru catalysts bearing the polydentate tripodal ligands 1,1,1-tris-(diphenylphosphinomethyl)ethane (triphos) and tris-[2-(diphenylphosphino)ethyl]amine (NP(3)), either made in situ from suitable Ru(III) precursors or as molecular complexes. Preliminary mechanistic studies highlighting subtle differences due to ligand effects in the corresponding systems under study are also presented.


Assuntos
Compostos de Bifenilo/química , Formiatos/química , Compostos Organometálicos/química , Fosfinas/química , Rutênio/química , Dióxido de Carbono/química , Catálise , Hidrogênio/química , Hidrogenação , Ligantes , Conformação Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA