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1.
J Food Prot ; 86(11): 100164, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37739314

RESUMO

Mulches are used to block light and retain soil moisture which may affect the survival of bacterial pathogens on soil. This study examined the effectiveness of different types of mulches to minimize microbial risk from contaminated water used for irrigation of cucumbers. A production bed of 120 ft2 with 18 beds (30 ft long) covered with five different types of mulch (paper, paper with fertilizer incorporated (PF), maize-based mulch, biodegradable plastic covering, and conventional plastic) including three beds with no cover was planted with Dasher 2 Variety cucumber. Soil samples from each bed were collected for the first five weeks to examine natural E. coli and coliforms. Well water contaminated with or without nalidixic acid-resistant mutant of E. coli (8 Log CFU/mL) was used for drip irrigation for 7 days before harvesting. Prior to irrigation with contaminated water, naturally present E. coli and coliform in the soil samples with or without mulch were in the range of 3.45-3.78 Log CFU/g and 4.18-5.31 Log CFU/g, respectively. E. coli levels on cucumbers harvested from mulched beds and irrigated with contaminated irrigation water had significantly higher (P < 0.05) levels of E. coli as compared with samples from similar beds irrigated with noncontaminated water. However, Cucumber, harvested within each irrigation water quality were not significantly different regardless of the type of mulch with E. coli levels from 1.72 to 3.30 Log CFU/cm2 (contaminated water) and 0.28-1.86 Log CFU/cm2 (noncontaminated water). A significant die-off of inoculated E. coli was observed on cucumber within 3 days (>1.17 Log CFU/cm2) and >1.38 Log CFU/cm2 after 4 days. Beds with maize mulch were effective on minimizing E. coli contamination on cucumber from contaminated irrigation water.


Assuntos
Cucumis sativus , Escherichia coli , Inocuidade dos Alimentos , Bactérias , Solo , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Contagem de Colônia Microbiana , Microbiologia do Solo
2.
Curr Res Food Sci ; 7: 100575, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37680695

RESUMO

Pickering emulsions (PE) are systems made up of two incompatible fluids, these are stabilized by solid organic or inorganic particles located on their interface. Cellulose nanocrystals (CNCs) are sustainable and biocompatible value-added naturally occurring biomolecules which are being investigated as PE stabilizers in the cosmetic, food, and pharmaceutical industries. The objective of this research was to investigate the efficacy of pineapple cellulose nanocrystals as stabilizers for a ginger essential oil-in-water Pickering emulsion. Anionic pineapple cellulose nanocrystals were prepared by acid hydrolysis. Ginger essential oil-in-water emulsions were prepared by ultrasonication. Pineapple CNC produced stable Pickering emulsions with surface average droplet size of 4.3 µm-6.2 µm, high negative zeta potential, high viscosity, and high adsorption at the interface. Pickering emulsions by ultrasonication were stable against droplet coalescence, phase separation, and droplet flocculation for at least 8 weeks at 25 °C or 40 °C at various droplet sizes. The emulsion droplet size and volume density (droplet size distribution) were evaluated by varying the particle concentration (CNC 0.25 g/100 ml or 0.50 g/100 ml) and/or oil fraction (10-20 g/100 ml). At constant oil fraction, the emulsion viscosity increased as the nanocrystal concentration increased. The cellulose nanocrystal-stabilized ginger oil-Pickering emulsions exhibited shear-thinning characteristics of a pseudo-plastic fluid. Pineapple nanocellulose crystal -stabilized ginger oil-Pickering emulsions exhibited high stability with a creaming index of zero. CNC was found to be an effective Pickering stabilizer for oil-in-water emulsions in various food applications.

3.
Rev Bras Ortop (Sao Paulo) ; 58(4): e557-e562, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37663190

RESUMO

Objective The present study compares the analgesic efficacy of two techniques to perform non-surgical reduction: fracture hematoma block and radial nerve supracondylar block. Methods Forty patients with fractures of the distal third of the radius, who required reduction, were selected in a quasi-randomized clinical trial to receive one of the anesthetic techniques. All patients signed the informed consent form, except for those who did not wish to participate in the study, had neurological injury, had contraindication to the procedure in the emergency room, or with contraindication to the use of lidocaine. To measure analgesia, the numerical pain rate scale was used at four different moments: preblock, postblock, during reduction, and after reduction; then three differences were calculated: the first between before and after blocking; the second between during reduction and after blockade; and the third between before blocking and after reduction. Results The fracture hematoma and supracondylar block groups showed the following mean values, respectively: 3.90 (1-10) and 3.50 (-6-10) in difference 1; 4.35 (-5-10) and 5.00 (-3-10) in difference 2; and 4.65 (1-10) and 3.80 (-3-10) in difference 3. Conclusion Both techniques proved to be efficient for analgesia, with mild superiority of hematoma block, but without statistical significance.

4.
Rev. bras. ortop ; 58(4): 557-562, July-Aug. 2023. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1521801

RESUMO

Abstract Objective The present study compares the analgesic efficacy of two techniques to perform non-surgical reduction: fracture hematoma block and radial nerve supracondylar block. Methods Forty patients with fractures of the distal third of the radius, who required reduction, were selected in a quasi-randomized clinical trial to receive one of the anesthetic techniques. All patients signed the informed consent form, except for those who did not wish to participate in the study, had neurological injury, had contraindication to the procedure in the emergency room, or with contraindication to the use of lidocaine. To measure analgesia, the numerical pain rate scale was used at four different moments: preblock, postblock, during reduction, and after reduction; then three differences were calculated: the first between before and after blocking; the second between during reduction and after blockade; and the third between before blocking and after reduction. Results The fracture hematoma and supracondylar block groups showed the following mean values, respectively: 3.90 (1-10) and 3.50 (-6-10) in difference 1; 4.35 (-5-10) and 5.00 (-3-10) in difference 2; and 4.65 (1-10) and 3.80 (-3-10) in difference 3. Conclusion Both techniques proved to be efficient for analgesia, with mild superiority of hematoma block, but without statistical significance.


Resumo Objetivo O estudo compara a eficácia analgésica de duas técnicas para realizar redução incruenta: o bloqueio de hematoma da fratura e o bloqueio supracondilar de nervo radial. Métodos Quarenta pacientes com fraturas do terço distal do rádio, que necessitassem redução, foram selecionados em um ensaio clínico quasi-randomizado, para receber uma das técnicas anestésicas. Todos os pacientes assinaram o termo de consentimento ou assentimento, com exceção daqueles que não desejassem participar do estudo, tivessem lesão neurológica, com contraindicação ao procedimento na sala de emergências, ou com contraindicação ao uso da lidocaína. Para aferir a analgesia foi utilizada a escala numérica da dor em quatro momentos distintos: pré-bloqueio, pós-bloqueio, durante a redução e após a redução; em seguida, foram calculadas três diferenças: a primeira entre antes e após o bloqueio; a segunda entre durante a redução e após o bloqueio; e a terceira entre antes do bloqueio e após a redução. Resultados Os grupos do bloqueio de hematoma de fratura e bloqueio supracondilar apresentaram respectivamente os seguintes valores médios: 3.90 (1-10) e 3.50 (-6-10) na diferença 1; 4.35 (-5-10) e 5.00 (-3-10) na diferença 2; e 4.65 (1-10) e 3.80 (-3-10) na diferença 3. Conclusão As duas técnicas se provaram eficientes para analgesia, com discreta superioridade do bloqueio de hematoma, mas sem significância estatística.


Assuntos
Humanos , Fraturas do Rádio , Medição da Dor , Redução Fechada , Anestesia Local , Bloqueio Nervoso
5.
Front Microbiol ; 14: 1151819, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37396364

RESUMO

Whole and fresh-cut produce are minimally processed and susceptible to microbial contamination. This study evaluated the survival or growth of L. monocytogenes on peeled rinds, and fresh-cut produce at different storage temperatures. Fresh-cut fruits and vegetables, including cantaloupe, watermelon, pear, papaya, pineapple, broccoli, cauliflower, lettuce, bell pepper, and kale (25 g pieces) were spot inoculated with 4 log CFU/g of L. monocytogenes and stored at 4 or 13°C for 6 days. Cantaloupe and bell pepper rind disks (20 cm2), mimicking whole produce were inoculated with low inoculum level (4 log CFU/mL) and high inoculum level (6 log CFU/mL) and stored at 24°C up to 8 days and 4°C up to 14 days, respectively. L. monocytogenes counts on fresh-cut pear samples stored at 4°C increased significantly by 0.27 log CFU/g. However, Listeria levels on kale (day 4), cauliflower (day 6), and broccoli (day 2) were significantly reduced by 0.73, 1.18, and 0.80 log CFU/g, respectively, at 4°C. At 13°C, the bacterial counts increased significantly after a day of storage on fresh-cut watermelons (increasing by 1.10 log CFU/g) and cantaloupes (increasing by 1.52 log CFU/g). Similar increases were observed on pears (1.00 log CFU/g), papayas (1.65 log CFU/g), and green bell peppers (1.72 log CFU/g). Pineapple samples did not support the growth of L. monocytogenes at 13°C with a significant reduction of 1.80 log CFU/g by day 6. L. monocytogenes levels significantly increased in fresh-cut lettuce at 13°C but remained stable on kale, cauliflower, and broccoli after 6 days of storage. Stable population was observed also on cantaloupe rinds up to 8 days at 24°C. While on the outer surface of bell peppers, the population level decreased below the detectable limit of the test (10 CFU/20 cm2) after 14 days of storage at 4°C. The results demonstrated variable survival behavior of L. monocytogenes on fresh-cut produce with produce type and storage temperature.

6.
Chemistry ; 29(42): e202300271, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37159057

RESUMO

High-valent metal-oxo species play critical roles in enzymatic catalysis yet their properties are still poorly understood. In this work we report a combined experimental and computational study into biomimetic iron(IV)-oxo and iron(III)-oxo complexes with tight second-coordination sphere environments that restrict substrate access. The work shows that the second-coordination sphere slows the hydrogen atom abstraction step from toluene dramatically and the kinetics is zeroth order in substrate. However, the iron(II)-hydroxo that is formed has a low reduction potential and hence cannot do OH rebound favorably. The tolyl radical in solution then reacts further with alternative reaction partners. By contrast, the iron(IV)-oxo species reacts predominantly through OH rebound to form alcohol products. Our studies show that the oxidation state of the metal influences reactivities and selectivities with substrate dramatically and that enzymes will likely need an iron(IV) center to catalyze C-H hydroxylation reactions.

7.
Mar Pollut Bull ; 189: 114800, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36898273

RESUMO

Human trampling represents one of the main anthropogenic pressures in the rocky intertidal. This habitat includes many ecosystem engineers such as mussels that provide biogenic habitat and multiple services. This research assessed potential impacts of human trampling on beds of the mussel, Mytilus galloprovincialis, on NW shores of Portugal. To test for direct effects of trampling on mussels and indirect effects on the associated assemblages, three treatments were applied: control (untouched beds), low and high intensity of trampling. Effects of trampling were dependent on the taxa. Thus, values of shell length of M. galloprovincialis were greater under the highest intensity of trampling while abundances of Arthropoda, Mollusca and Lasaea rubra showed the opposite pattern. Moreover, total number of taxa and abundances of Nematoda and Annelida showed higher values under low trampling intensity. The implications of these results to manage human use in areas with ecosystem engineers are discussed.


Assuntos
Ecossistema , Mytilus , Animais , Humanos , Portugal
8.
Foods ; 13(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38201174

RESUMO

The attachment strength of bacteria to surfaces can affect the efficacy of sanitizers during washing. This study aimed to determine the effectiveness of chlorination and aeration in the removal of pathogens from the surface of produce. Cucumbers and bell peppers were inoculated with Listeria innocua, Escherichia coli O157:H7, or Salmonella enterica; afterwards, the produce was washed with or without chlorinated water (100 ppm) for 3 min in combination with or without aeration. Cucumbers washed with chlorinated water, with or without aeration, presented significant reductions of L. innocua (3.65 log CFU/cm2 and 1.13 log CFU/cm2, respectively) (p < 0.05). Similarly, bell peppers washed in chlorinated water with aeration (1.91 log CFU/g) and without aeration (2.49 log CFU/g) presented significant reductions of L. innocua. A significant reduction of L. innocua was observed on bell peppers washed with non-chlorinated water with aeration (2.49 log CFU/g) (p < 0.05). Non-chlorinated water was also effective in significantly reducing the level of Salmonella enterica (p < 0.05) on cucumbers and bell peppers. Washing with chlorinated water with aeration reduced Salmonella enterica levels from 4.45 log CFU/cm2 on cucumbers to below the detectable limit (0.16 log CFU/cm2). The highest reduction of Salmonella enterica from bell peppers occurred after washing with chlorinated water with aeration (2.48 log CFU/g). E. coli O157:H7, L. innocua, and Salmonella enterica levels present in non-chlorinated water after washing contaminated produce with or without aeration were significantly greater than those in chlorinated water (p < 0.05). After treatment, the population levels of all pathogens in chlorinated water with or without aeration were below the detectable limit for bell peppers (<1.10 log CFU/mL) and cucumbers (<1.20 log CFU/mL). Using chlorine in combination with forced aeration during washing minimizes cross-contamination of bacterial pathogens.

9.
Chem ; 9(9): 2601-2609, 2023 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-39021493

RESUMO

Iron sulfur clusters are critical to a plethora of biological processes; however, little is known about the elementary unit of these clusters, namely the [Fe=S]n+ fragment. Here, we report the synthesis and characterization of a terminal iron sulfido complex. Despite its high spin (S = 5/2) ground state, structural, spectroscopic, and computational characterization provide evidence for iron sulfur multiple bond character. Intriguingly, the complex reacts with additional sulfur to afford an S = 3/2 iron(III) disulfido (S2 2-) complex. Preliminary studies reveal that the sulfido complex reacts with dihydroanthracene to afford an iron(II) hydrosulfido complex, akin to the reactivity of iron oxo complexes. By contrast, there is no reaction with the disulfido complex. These results provide important insight into the nature of the iron sulfide unit.

10.
Mar Pollut Bull ; 185(Pt B): 114346, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36413932

RESUMO

Marinas are hot spots of non-indigenous marine species (NIS). Introductions of NIS, regardless of their actual or potential impacts, can be considered as a biocontamination of the ecosystem. To characterize the biocontamination status of a marina it is important to know which habitats and major taxa can provide the most useful information. To address this issue, we analyze the associated macrofaunal community associated to soft substrate (sediment; SS) and artificial hard substrate (lateral surface of pontoons; AHS) of six marinas from Southern Spain. 9 NIS were found, including 8 crustaceans (7 peracarids) and 1 polychaete; 8 NIS were found on AHS and 4 in sediments. Indeed, site-specific BioContamination Index (SBCI) showed higher values in AHS than SS. Our results indicate peracarids in AHS should be the primary target for assessing the level of biocontamination in marinas. This may help scientists and environmental managers to stablish strategies for monitoring marine bioinvasions.


Assuntos
Ecossistema , Espanha
11.
J Am Chem Soc ; 144(39): 17824-17831, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36154168

RESUMO

We report an iron-based graphite-conjugated electrocatalyst (GCC-FeDIM) that combines the well-defined nature of homogeneous molecular electrocatalysts with the robustness of a heterogeneous electrode. A suite of spectroscopic methods, supported by the results of DFT calculations, reveals that the electrode surface is functionalized by high spin (S = 5/2) Fe(III) ions in an FeN4Cl2 coordination environment. The chloride ions are hydrolyzed in aqueous solution, with the resulting cyclic voltammogram revealing a Gaussian-shaped wave assigned to 1H+/1e- reduction of surface Fe(III)-OH surface. A catalytic wave is observed in the presence of NO3-, with an onset potential of -1.1 V vs SCE. At pH 6.0, GCC-FeDIM rapidly reduces NO3- to ammonium and nitrite with 88 and 6% Faradaic efficiency, respectively. Mechanistic studies, including in situ X-ray absorption spectroscopy, suggest that electrocatalytic NO3- reduction involves an iron nitrosyl intermediate. The Fe-N bond length (1.65 Å) is similar to that observed in {Fe(NO)}6 complexes, which is supported by the results of DFT calculations.


Assuntos
Compostos de Amônio , Grafite , Cloretos , Compostos Férricos/química , Ferro/química , Modelos Moleculares , Nitratos , Nitritos , Óxidos de Nitrogênio
12.
Front Nutr ; 9: 871243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35942168

RESUMO

Fresh and fresh-cut fruits and vegetables have been associated in several foodborne illness outbreaks. Although investigations from those outbreaks reported that the contamination with pathogenic microorganisms may occur at any point in the farm to fork continuum, effective control strategies are still being widely investigated. In that direction, the concept of hurdle technology involving a sequence of different interventions have been widely explored. Among those interventions, ultraviolet (UV) light alone or in combination with other treatments such as use of organic acids or sanitizer solutions, has found to be a promising approach to maintain the microbiological safety and quality of fresh and fresh-cut produce. Recent advances in using UV as a part of hurdle technology on the safety of fresh produce at different stages are presented here. Furthermore, this review discusses the mechanism of UV induced antimicrobial activity, factors that influence antimicrobial efficacy and its effect on produce. In addition, the challenges, and prospects of using UV irradiation as an intervention treatment were also discussed.

13.
PLoS One ; 17(6): e0269308, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35648792

RESUMO

Biodiversity loss is considered one of the main threats to marine ecosystems. In this framework of biodiversity decline, organisms that provide biogenic habitat play a relevant role by their capacity to structure assemblages and influence ecological processes. The Mediterranean mussel Mytilus galloprovincialis is considered an ecosystem engineer because it alters local environmental conditions maintaining habitat suitability for other organisms, and enhancing local biodiversity. Although it is widely recognized that mussel beds increase diversity, the drivers shaping these assemblages are poorly explored. We investigate whether mussel size homogenisation shapes the abundance, richness and structure of macrobenthic assemblages associated with mussel beds in two shores of the Galician coast (NW Spain). At each shore, two sites, 10 m apart, were selected and at each site, faunal assemblages were compared between mussel clumps showing shells of various sizes (control), and mussel clumps with closely similar-sized mussels, considered as homogenised. Homogenised clumps showed, in general, higher values in total number of individuals and species than control clumps. Regarding the effect of mussel size homogenisation on the multivariate structure of the assemblages, significant differences between control and homogenised clumps were found in three out of the four sites. Most relevant associated species usually reached higher abundances in homogenised clumps than control ones. Therefore, mussel size homogenisation influenced the structure of the macrofaunal assemblages associated with mussel beds but, its effect was context dependent (i.e., varied with sites). Information about the species contribution to dissimilarities among homogenised and control clumps was provided and the potential influence of sediment and algae on mussel clumps was discussed.


Assuntos
Ecossistema , Mytilus , Animais , Biodiversidade , Humanos , Alimentos Marinhos , Espanha
14.
PeerJ ; 10: e13126, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35441057

RESUMO

Eunice woodwardiBaird, 1869, originally described from the Ría de A Coruña (NW Iberian Peninsula), has been overlooked and never reported from the Atlantic coast of Spain after original description and the subsequent redescription of the holotype. In the present study, we revised comparatively the holotype, newly collected specimens of this species and specimens identified as Eunice vittata (Delle Chiaje, 1829) from western Mediterranean Sea. The validity of E. woodwardi is supported and previous descriptions are complemented after a throughout study of the external morphology by means of light compound microscopy and scanning electron microscopy, and that of the internal anatomy by histological sectioning and micro-computed tomography. The presence of eyes, nuchal organs, dorsal and ventral ciliary organs on parapodial cirri and paired nephridia in most segments is confirmed in E. woodwardi; the digestive tract is clearly regionalized and divided into pharynx, oesophagus, stomach, fore, mid- and hind intestine. The presence of E. woodwardi in the Ría de Ferrol is also reported, and we suggest that previous records of E. vittata in NW Iberian Peninsula should be reviewed. Eunice woodwardi is distinguished by a set of characters such as having non-articulated and non-constricted cephalic appendages, the maxillary formula, the range of branchial distribution, maximum number of branchial filaments, number of limbate and compound falciger chaetae per parapodium, the presence of an apical mucro in the guard of falciger chaetae blades and the number of teeth in pectinate chaetae. Epibiont Ciliophora on branchiae are also reported.


Assuntos
Anelídeos , Apocynaceae , Poliquetos , Animais , Microtomografia por Raio-X , Poliquetos/anatomia & histologia , Espanha , Europa (Continente)
15.
Zookeys ; 1132: 85-126, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36760494

RESUMO

Several new species of genus Terebellides Sars, 1835 (Annelida, Trichobranchidae) have been recently described from the Northeast Atlantic Ocean after the detection of a large complex of species based on DNA sequence data from previous research. Some of those species (belonging to the so-called Group A) have already been described elsewhere. In this paper, we revise several Terebellides clades belonging to Groups B, C and D resulting in the identification of five nominal species: Terebellidesgracilis Malm, 1874, Terebellidesatlantis Williams, 1984, Terebellideswilliamsae Jirkov, 1989, Terebellidesirinae Gagaev, 2009, and Terebellidesshetlandica Parapar, Moreira & O'Reilly, 2016, plus one new species described here as Terebellideslavesquei sp. nov. All these species are characterised by a combination of morphological features complemented with a nucleotide diagnostic approach (specific COI nucleotides in the alignment position). Morphological characters used to discriminate between taxa refer to the branchial shape, presence/absence of ciliated papillae dorsal to thoracic notopodia and the morphology of thoracic and abdominal uncinal teeth. An updated identification key to all described species of this genus in NE Atlantic waters is also included.

16.
ACS Cent Sci ; 7(10): 1751-1755, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34729418

RESUMO

The iron oxo unit, [Fe=O] n+ is a critical intermediate in biological oxidation reactions. While its higher oxidation states are well studied, relatively little is known about the least-oxidized form [FeIII=O]+. Here, the thermally stable complex PhB(AdIm)3Fe=O has been structurally, spectroscopically, and computationally characterized as a bona fide iron(III) oxo. An unusually short Fe-O bond length is consistent with iron-oxygen multiple bond character and is supported by electronic structure calculations. The complex is thermally stable yet is able to perform hydrocarbon oxidations, facilitating both C-O bond formation and dehydrogenation reactions.

17.
Zootaxa ; 5052(4): 501-528, 2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34810858

RESUMO

Polyophthalmus zhadanae sp. nov. (Annelida, Opheliidae), is described from the coast of Kuwait and Saudi Arabia (Arabian Gulf) after specimens collected in the intertidal and shallow subtidal. This new species is characterised by the body pigmentation pattern, distribution of lateral eyes, presence of small dorsal and ventral parapodial cirri and pygidial features. External and internal anatomy was described after examination with SEM and micro-CT. The presence of several body structures in the genus such as a cephalic palpode-like papilla is discussed. Furthermore, the diversity of genus Polyophthalmus and the presence of Polyophthalmus pictus (Dujardin, 1839) in the Indo-Pacific is reviewed and a key to species is provided.


Assuntos
Anelídeos , Poliquetos , Distribuição Animal , Animais
18.
J Am Chem Soc ; 143(43): 18121-18130, 2021 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-34698493

RESUMO

Enzymes exert control over the reactivity of metal centers with precise tuning of the secondary coordination sphere of active sites. One particularly elegant illustration of this principle is in the controlled delivery of proton and electron equivalents in order to activate abundant but kinetically inert oxidants such as O2 for oxidative chemistry. Chemists have drawn inspiration from biology in designing molecular systems where the secondary coordination sphere can shuttle protons or electrons to substrates. However, a biomimetic activation of O2 requires the transfer of both protons and electrons, and molecular systems where ancillary ligands are designed to provide both of these equivalents are comparatively rare. Here, we report the use of a dihydrazonopyrrole (DHP) ligand complexed to Fe to perform exactly such a biomimetic activation of O2. In the presence of O2, this complex directly generates a high spin Fe(III)-hydroperoxo intermediate which features a DHP• ligand radical via ligand-based transfer of an H atom. This system displays oxidative reactivity and ultimately releases hydrogen peroxide, providing insight on how secondary coordination sphere interactions influence the evolution of oxidizing intermediates in Fe-mediated aerobic oxidations.


Assuntos
Complexos de Coordenação/química , Oxigênio/química , Peróxidos/química , Complexos de Coordenação/síntese química , Hidrazonas/síntese química , Hidrazonas/química , Ferro/química , Ligantes , Oxirredução , Pirróis/síntese química , Pirróis/química
19.
Foods ; 10(4)2021 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-33801608

RESUMO

Pecan shells are a rich source of various bioactive compounds with potential antioxidant and antimicrobial properties. This study investigated the effect of pecan variety and method extraction on the antioxidant property of shell extracts. Twenty different varieties of pecan shells were subjected to either aqueous or ethanolic extraction and were examined for total phenolics and antiradical activity. The phenolic content and antiradical activity of shell extracts were significantly (p < 0.05) varied with different pecan cultivars. The total phenolic content of ethanol extracts ranged from 304.2 (Caddo) to 153.54 (Cherokee) mg GAE/g of dry extract and was significantly greater (p < 0.05) than those obtained by aqueous extraction. The antiradical activity of ethanol extracts ranged from 840.6 (Maramec) to 526.74 (Caper Fear) mg TEg-1, while aqueous extracts ranged from 934.9 (Curtis) to 468.3 (Elliot) mg TEg-1. Chemical profiling of the crude and acid hydrolyzed extracts was performed by reverse phase high performance liquid chromatography and flow injection electrospray ionization mass spectrometry. Lignin degradation products such as lignols, dilignols, trilignols, and oligolignols were found to be the major components of tested extracts. Phenolic content and antiradical activity of pecan shell extracts are significantly varied with cultivars and methods of extraction.

20.
J Environ Manage ; 286: 112237, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33676130

RESUMO

The importance of marinas as infrastructures for recreational boating is increasing substantially. However, information on their soft-bottom benthic communities, a key tool for managing programmes, is still scarce. We combined environment features with macro- and meiofaunal soft-bottom community information for assessing the ecological status of marinas with an integrative approach. To address this issue, we focused on eight marinas of the Southern Iberian Peninsula. Macro- and meiofauna data revealed high benthic heterogeneity at a spatial scale. The environmental variables which correlated best with macrofauna were mainly phosphorus, granulometry, and total organic carbon, and secondarily important variables were faecal coliforms, the biocide Irgarol, and heavy metals; total hydrocarbon concentration was also significant for meiofauna. Annelida was the dominant phylum in terms of number of species (37%) and abundance (66%) and were better descriptors of the environmental conditions than Arthropoda and Mollusca. Although identification to the species level is desirable and mandatory for assessing biological pollution, significant differences among marinas and correlations between fauna and abiotic variables were already detected at the level of family and order. This implies that biota assessment at higher levels may still be useful in monitoring programmes limited by time and budget constraints. The major novelty of this study lies in the development of an integrative assessment method based on the following selected ecological indicators: Marinas Environmental Pollution Index (MEPI), Biocontamination Index (BCI), macrofaunal biotic indices (AMBI, M-AMBI, BENTIX, MEDOCC and BENFES), macrofaunal taxa richness and Shannon-Wiener's diversity, and nematode:copepod index. This approach was able to discriminate marinas of the Southern Iberian Peninsula based on their ecological status, which ranged from poor to good. The method can be useful to design standards for assigning "sustainable quality seals" to those marinas with better values of ecological indicators.


Assuntos
Ecossistema , Metais Pesados , Animais , Biodiversidade , Biota , Monitoramento Ambiental , Invertebrados , Metais Pesados/análise
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