Nowadays, there is a strong demand on the search of thinner, but more effective organic coatings for corrosion protection of metallic substrates, like galvanised steel, used in the automotive ...industry. In order to guarantee effective corrosion protection of these coatings, and because chromate-based pigments cannot be used, one of the most attractive strategies consists on the modification of the organic matrix with nano-additives filled with corrosion inhibitors, which can be released to the active sites. In this work, two different nano-additives are explored as potential self-healing materials for the development of active protective coatings. These additives are layered double hydroxides and cerium molybdate hollow nanospheres loaded with mercaptobenzothiazole, as a corrosion inhibitor. These additives were added to epoxy primers, individually, or combining the two nanoadditives in the same layer.
The electrochemical behaviour and the potential of self-healing ability were studied by electrochemical impedance spectroscopy, scanning vibrating electrode technique and scanning ion-selective electrode technique. The results reveal that both types of nanocontainers can provide effective corrosion inhibition on artificial induced defects, at different stages of the degradation process. Moreover, the results also show that there is a synergistic effect concerning corrosion inhibition and self-healing potential when a mixture of the two nanocontainers is used. The mechanism of self healing is presented and discussed in terms of effect of organic inhibitor and role of the nanocontainers, including effect of cerium ions released from cerium molibdate nanoparticles.
The growth of ZnAl layered double hydroxide (LDH) on the AA2024 surface was monitored using synchrotron high-resolution X-ray diffraction. Data were analyzed using the Avrami–Erofe’ev kinetic model. ...Accordingly, the LDH film growth is governed by a two-dimensional (2D) diffusion-controlled reaction with a zero nucleation rate. Additional methods, including ex situ atomic force microscopy/scanning Kelvin probe force microscopy (AFM/SKPFM) supported by in situ open-circuit potential (OCP) measurements together with scanning electron microscopy (SEM) and transmission electron microscopy with energy-dispersive X-ray spectroscopy (TEM/EDX) analysis, provided further insight into the different stages of the mechanism of LDH growth. Prior to the conversion coating formation, an intermediate layer is formed as a basis for the establishment of the LDH flakes. Moreover, a Cu-rich layer was revealed, which could contribute to the acceleration of LDH growth. The formed LDH layer does not show any cracks at the interface but presents minor irregularities in the structure, which could favor adhesion to subsequent organic coatings. The findings presented in this work provide an important insight to the corrosion performance of the LDH conversion coatings and the pathway to adopt for further optimization.
•Inhibition of MMP-9 activity is an important anticancer strategy.•Among eight studied legume species, only a few contained MMP-9 inhibitors.•Their inhibitory activity was consistent with a reduction ...of HT29 cell migration.•Lupin was the best inhibitor, while pea was the less effective.•Differences found help to select legume potential for anticancer diets.
MMP-9 activity is strongly related to cancer growth and metastization. This study aimed at assessing the inhibitory potential of the major seed protein fractions from eight selected legume species towards MMP-9 activity in colon carcinoma cells. Albumin and globulin fractions were screened for MMP-9 inhibitors, using a fluorometric assay and gelatin zymography. Their effect on HT29 cell proliferation and cell migration was tested, as well as on the corresponding intrinsic cellular MMP-9 activities. Seed proteins include potent inhibitors of MMP-9, particularly low molecular mass proteins. Their effectiveness differs greatly among species, with a positive correlation detected between their inhibitory activity and the reduction in cell migration. Lupin seeds contain the most efficient MMP-9 inhibitors of all legume seeds analyzed, inhibiting both gelatinases and HT29 migration and growth, while pea seeds showed no effect. Results reveal legume protein MMPIs as novel metalloproteinase inhibitors with possible pharmacological interest. This may be important for selecting leguminous species with potential use in anti-cancer diets.
Most studies evaluating the use of essential oils (EO) as antibacterial agents focus mainly on minimal inhibitory concentrations (MIC) rather than minimal bactericidal concentrations (MBC). In this ...work, we compared MICs and MBCs of EO from condiment plants commonly used in Mediterranean Europe, namely
Origanum vulgare
,
Salvia lavandulaefolia
,
Salvia officinalis
,
Salvia sclarea
and
Rosmarinus officinalis
, aiming to evaluate their application as disinfecting agents in minimally processed produce. Outbreaks-related pathogens such as
Listeria monocytogenes
,
Pseudomonas aeruginosa
and
Yarrowia lipolytica
were used. Results showed that all EO were able to reduce bacterial growth in all bacterial strains tested, particularly
O. vulgare
. However, fewer EO exhibited bactericidal activities, and were only effective against one or two bacterial strains, hence eliminating the possibility to use them as broad range disinfectants. Furthermore, the necessary concentrations were too high for food application. Hence, our work suggests the need to evaluate MBC rather than MIC and questions EO usefulness in controlling undesired microorganisms. Overall, and despite the large volume of data published on EO, results obtained were not very encouraging for a realistic application on produce and question the viability of EOs as disinfecting agents in food.
Introdução: A leucemia mieloide crônica (LMC) é um tipo de neoplasia mieloproliferativa da medula óssea. Caracteriza-se pela alteração da produção das células da linhagem mieloide (proliferação ...excessiva de granulócitos maduros e em amadurecimento) e presença do cromossomo Philadelphia (Ph+), originada da translocação dos cromossomos 9q34 e 22q11, resultando na formação da proteína híbrida BCR-ABL, com atividade da tirosino quinase elevada. Patologia rara e progressão lenta, cursa com três fases: crônica, acelerada e blástica. Os sintomas podem ser inespecíficos, leves ou até inexistentes a depender da fase de evolução da doença. Objetivo: Relatar o caso de um paciente com LMC e manifestação atípica para policitemia vera. Material e métodos: Trata-se de uma revisão de prontuário e bibliográfica a partir do uso de bancos de dados do PubMed, Biblioteca Eletrônica Científica Online (SciELO), portaria e protocolos do MS. Relato de caso: E.P.C, 30 anos, masculino, procurou atendimento médico com relato de tontura, cefaleia e visão turva. Aos exames laboratoriais, apresentava elevação da hemoglobina (Hb 18,6), hematócrito (59) e leucocitose (19.000) sem desvio escalonado, suspeitando inicialmente de Policitemia Vera. Realizada dosagem de Eritropoetina, com valores reduzidos (1,0), porém exame JAK2 V617F, resultou negativo. Biópsia de medula óssea apresentava hiperplasia de série granulocítica e megacariocítica; com hipótese diagnóstica de Neoplasia Mieloproliferativa. Seguiu-se investigação com pesquisa de JAK2 exon 12 também com resultado negativo. Em sua evolução, devido à hipótese de neoplasia Mieloproliferativa, apesar de manifestação clínica, pouco característica, foi solicitado PCR para BCR-ABL com resultado positivo, compatível com diagnóstico de Leucemia mieloide crônica, com apresentação laboratorial atípica. Introduziu-se terapia com hidroxiureia até liberação de tratamento com imatinibe pelo MS. Discussão: Existem outros distúrbios mieloproliferativos crônicos que possuem algumas semelhanças clínicas e biológicas com a LMC, sendo a Policitemia Vera (PV) um exemplo de diagnóstico diferencial. A PV é uma doença também originada de uma mutação genética e pode progredir em formas mais graves da doença, mimetizando a LMC. Durante a investigação clínica, as hipóteses diagnósticas são eliminadas de acordo com as diferenças encontradas sendo as mais importantes: quanto aos tipos de células afetadas, apresentações dos sinais e sintomas, e também de testes moleculares específicos de cada patologia. Na LMC encontra-se leucocitose com desvio à esquerda, na PV pode haver aumento das três séries com predomínio na série vermelha. Conclusão: É fundamental uma boa anamnese, investigação clínica, laboratorial, assim como a detecção da mutação genética do paciente. O diagnóstico oportuno e correto é importante para o tratamento precoce da LMC. O tratamento e acompanhamento são feitos por meio de terapia alvo específica com os inibidores da tirosinoquinase que bloqueiam a ação da proteína BCR-ABL.
This study aims to evaluate the effects of adding alpha lipoic acid (ALA) to the in vitro ovarian tissue culture medium, either fresh or after vitrification/warming. For this purpose, 10 ovaries from ...five adult sheep were used. Each pair of ovaries gave rise to 16 fragments and were randomly distributed into two groups: fresh (n = 8) and vitrified (n = 8). Two fresh fragments were fixed immediately and considered the control, while another six were cultured in vitro for 14 days in the absence; presence of a constant (100 μM/0–14 day) or dynamic (50 μM/day 0–7 and 100 μM/day 8–14) concentration of ALA. As for the vitrified fragments, two were fixed and the other six were cultured in vitro under the same conditions described for the fresh group. All the fragments were subjected to morphological evaluation, follicular development and stromal density (classical histology), DNA fragmentation (TUNEL), senescence (Sudan Black), fibrosis (Masson's Trichome), and endoplasmic reticulum stress (immunofluorescence). Measurements of the antioxidant capacity against the free radicals 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and estradiol (E2) levels in the culture medium was performed. The results showed that in the absence of ALA, in vitro culture of vitrified ovarian fragments showed a significant reduction (P < 0.05) in follicular morphology and increased the presence of senescence and tissue fibrosis (P < 0.05). Dynamic ALA maintained E2 levels unchanged (P > 0.05) until the end of vitrified ovarian tissue culture and controlled the levels of ABTS and DPPH radicals in fresh or vitrified cultures. Therefore, it is concluded that ALA should be added to the vitrified ovarian tissue in vitro culture medium to reduce the damage that leads to loss of ovarian function. To ensure steroidogenesis during in vitro culture, ALA should be added dynamically (different concentrations throughout culture).
•Addition of ALA to vitrified ovary in vitro culture medium reduces fibrosis and cellular senescence.•In vitro culture of vitrified ovary to restore endocrine function.•Conservation of ovarian follicles in situ.
•Airways exposure to SEB causes acute lung inflammation.•Airways exposure to SEB induces accumulation of bone marrow (BM) immature neutrophils.•SEB airways exposure increases BM neutrophils adhesion ...to ICAM-1.•SEB airways exposure did not modify BM neutrophils MAC-1 and LF1A-α expression.•SEB induces BM elevations of GM-CSF, G-CSF, IFN-γ, TNF-α, KC/CXCL1, SDF-1α and MIP-2.•Our results contribute to elucidate BM events during SEB-induced lung inflammation.
The lung infections by Staphylococcus aureus are strongly associated with its ability to produce enterotoxins. However, little is known about the mechanisms underlying trafficking of bone marrow (BM) neutrophils during airway inflammation induced by Staphylococcal enterotoxin B (SEB). We therefore aimed to investigate the effects of mouse airways SEB exposure on BM neutrophil counts and its adhesive properties as well as on the release of cytokines/chemokines that orchestrate BM neutrophils trafficking to lung tissue.
Male BALB/c mice were intranasally exposed to SEB (1 µg), and at 4, 16 and 24 h thereafter, BM, circulating blood, bronchoalveolar lavage (BAL) fluid and lung tissue were collected. BM neutrophils adhesion, MAC-1 and LFA1-α expressions (by flow cytometry) as well as measurement of cytokine and/or chemokines levels were assayed after SEB-airway exposure.
Prior exposure to SEB promoted a marked influx of neutrophils to BAL and lung tissue, which was accompanied by increased counts of BM immature neutrophils and blood neutrophilia. BM neutrophil expressions of LFA1-α and MAC-1 were unchanged by SEB exposure whereas a significant enhancement of adhesion properties to VCAM-1 was observed. The early phase of airway SEB exposure was accompanied by high levels of GM-CSF, G-CSF, IFN-γ, TNF-α and KC/CXCL1, while the latter phase by the equilibrated actions of SDF1-α and MIP-2.
Mouse airways exposure to SEB induces BM cytokines/chemokines release and their integrated actions enhance the adhesion of BM neutrophils leading to acute lung injury.
The use of organophilic bentonites as additives in organic-based drilling fluids has long been a subject of study, but few studies have focused on the modification of these clays with nonionic ...surfactants. The advantage of nonionic surfactants over ionic ones is that they improve the thermal and chemical properties of organoclays (OC), and are also more readily biodegradable. The work described here involves a study of bentonites modified by nonionic surfactants, aiming at their use as dispersants in the composition of organic-based drilling fluids. The organophilization process was analyzed by X-ray diffraction and thermogravimetry, and the interaction of organoclays with the solvent medium was assessed based on the swell index and the determination of the apparent viscosity of clay-containing dispersions. The results indicate an effective intercalation of the nonionic surfactants in organoclays, and the content of incorporated surfactants was also quantified. The swelling results demonstrate chemical compatibility between diesel and kerosene organic media and the organoclays produced. From the rheological standpoint, some of the organophilic clay samples present a potential for use as raw materials for additives in organic-based drilling fluids, despite being considered of poor quality when analyzed for water-based drilling fluids.
•Nonionic surfactants were effective in the intercalation of interlayer spaces.•Combined use of organophilization agents produced the best results.•Clays unsuitable for water-based muds can be used as organoclays in oil-based fluids.
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