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1.
Polymers (Basel) ; 15(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36679282

RESUMO

We report on the stabilization of an oil-in-water (O/W) emulsion to, combined with interfacial polymerization, produce core-shell polyurea microcapsules (MCs) containing isophorone diisocyanate (IPDI). These will act as crosslinkers for mono-component adhesives. The emulsion stabilization was evaluated using three types of stabilizers, a polysaccharide (gum arabic) emulsifier, a silicone surfactant (Dabco®DC193), a rheology modifier (polyvinyl alcohol), and their combinations. Emulsion sedimentation studies, optical microscopy observation, and scanning electron microscopy enabled us to assess the emulsions stability and droplet size distribution and correlate them to the MCs morphology. Fourier transform infrared spectroscopy and thermogravimetric analysis revealed the MCs composition and enabled us to evaluate the encapsulation yield. All stabilizers, except DC193, led to spherical, loose, and core-shelled MCs. The rheology modifier, which increases the continuous phase viscosity, reduces the emulsion droplets sedimentation, keeping their size constant during the MCs' synthesis. This allowed us to obtain good quality MCs, with a smaller average diameter, of approximately 40.9 µm mode, a narrower size distribution and 46 wt% of encapsulated IPDI. We show the importance of the emulsion stability to tune the MCs morphology, size, and size distribution, which are critical for improved homogeneity and performance when used, e.g., in natural and synthetic adhesive formulations industry.

2.
Macromol Biosci ; 23(2): e2200240, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36443994

RESUMO

Cartilage replacement materials exhibiting a set of demanding properties such as high water content, high mechanical stiffness, low friction, and excellent biocompatibility are quite difficult to achieve. Here, poly(p-phenylene-2,6-benzobisoxazole) (PBO) nanofibers are combined with polyvinyl alcohol (PVA) to form a super-strong structure with a performance that surpasses the vast majority of previously existing hydrogels. PVA-PBO composites with water contents in the 59-76% range exhibit tensile and compressive moduli reaching 20.3 and 4.5 MPa, respectively, and a coefficient of friction below 0.08. Further, they are biocompatible and support the viability of chondrocytes for 1 week, with significant improvements in cell adhesion, proliferation, and differentiation compared to PVA. The new composites can be safely sterilized by steam heat or gamma radiation without compromising their integrity and overall performance. In addition, they show potential to be used as local delivery platforms for anti-inflammatory drugs. These attractive features make PVA-PBO composites highly competitive engineered materials with remarkable potential for use in the design of load-bearing tissues. Complementary work has also revealed that these composites will be interesting alternatives in other industrial fields where high thermal and mechanical resistance are essential requirements, or which can take advantage of the pH responsiveness functionality.


Assuntos
Materiais Biocompatíveis , Nanofibras , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Teste de Materiais , Hidrogéis/farmacologia , Hidrogéis/química , Cartilagem , Álcool de Polivinil/farmacologia , Álcool de Polivinil/química , Água/química
3.
Polymers (Basel) ; 16(1)2023 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-38201776

RESUMO

We employed microemulsion combined with the solvent evaporation technique to produce biodegradable polycaprolactone (PCL) MCs, containing encapsulated isophorone diisocyanate (IPDI), to act as crosslinkers in high-performance adhesive formulations. The MC production process was optimized by applying a design of experiment (DoE) statistical approach, aimed at decreasing the MCs' average size. For that, three different factors were considered, namely the concentration of two emulsifiers, polyvinyl alcohol (PVA) and gum arabic (GA); and the oil-to-water phase ratio of the emulsion. The significance of each factor was evaluated, and a predictive model was developed. We were able to decrease the average MC size from 326 µm to 70 µm, maintaining a high encapsulation yield of approximately 60% of the MCs' weight, and a very satisfactory shelf life. The MCs' average size optimization enabled us to obtain an improved distributive and dispersive mixture of isocyanate-loaded MCs at the adhesive bond. The MCs' suitability as crosslinkers for footwear adhesives was assessed following industry standards. Peel tests revealed peel strength values above the minimum required for casual footwear, while the creep test results indicated an effective crosslinking of the adhesive. These results confirm the ability of the MCs to release IPDI during the adhesion process and act as crosslinkers for new adhesive formulations.

4.
Neuroophthalmology ; 44(2): 76-88, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32395154

RESUMO

Observing optic disc pallor during a patient's first visit frequently raises a diagnostic challenge, particularly in regards to whether the cause is due to glaucoma or another form of optic neuropathy. Bruch's membrane opening (BMO) was recently discovered as the anatomical border of the optic disc. BMO minimum rim width (BMO-MRW) seems to be a reliable representation of the neuroretinal rim. In our study, we demonstrate the ability of BMO-MRWs to differentiate between glaucomatous and non-glaucomatous. Additionally, we propose an MRW ratio which may allow discrimination of open angle glaucoma from either non-arteritic anterior ischaemic optic neuropathy or compressive optic neuropathy.

5.
Sci Total Environ ; 703: 135548, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31767319

RESUMO

Plant growth promoting rhizobacteria (PGPR) is an alternative to chemical fertilizers for sustainable, environment friendly agriculture. There is a need to develop strategies to potentiate the interaction between rhizobacteria and plants. Flavonoids and organic acids (components of root exudates) play specific beneficial roles as carbon sources and signal molecules in the plant - rhizobacteria interactions. The goal of this work is to encapsulate signal molecules, namely citric acid and naringin, an organic acid and a flavonoid, respectively, by a biodegradable polymer, polycaprolactone (PCL), in order to maintain the stability and activity of those signal molecules and enable their slow or controlled release over a selected period of time, according to the needs of the plants. This approach is expected to potentiate food crops, namely peanut crop, in adverse environmental conditions (water deficit), by promoting the beneficial interaction between the peanut plant (A. hypogaea) and rhizobacteria. The microcapsules (MCs) are obtained by an emulsion process combined with solvent evaporation technique and are characterized by scanning electron microscopy, thermogravimetry and Fourier transformed infrared spectroscopy. The kinetics of in vitro release of encapsulated molecules, in a period where the uptake of the compound in plants can occur, is studied. The encapsulation synthesis parameters that lead to the best encapsulation process yield and efficiency, as well as to the best final performance in terms of release, are identified. The effect of pH and molecular weight of PCL is found to mediate the release properties of the molecules for different types of soil. PCL 45000 Mw dissolved at 16% in dichloromethane leads to an encapsulation efficiency of 75% and the resulting MCs containing naringin exhibit a slow release profile for 30 days, unmodified by pH, enabling their use in soils of different characteristics. This research makes possible the manufacturing of smart materials for sustainable agriculture practices.


Assuntos
Agricultura/métodos , Ácido Cítrico/análise , Monitoramento Ambiental , Poliésteres/análise , Microbiologia do Solo , Cápsulas , Fertilizantes , Desenvolvimento Vegetal
6.
Front Psychiatry ; 10: 305, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31133896

RESUMO

Background: Children of parents with mental illness (COPMI) are a high-risk group. There is a strong association between parents' psychiatric disorders and the incidence of psychopathology in their children. These children need to be identified and supported by mental health workers early, and hence, clinical practice in adult mental health services needs to change from a focus on individual patients to a more systemic family focus. "Semente," a mental health promotion program developed by the Psychiatry Service of Fernando Fonseca hospital (Lisbon, Portugal), had been established to identify these children and families and promote their mental health, by decreasing the impact of risk factors and promoting protective factors. The program included preventive COPMI interventions and implementation of activities offered to families with children in the mental health care. The aim of the present study was to evaluate changes in mental health care after the training in "Child Talks" intervention (two to three psycho-educational meetings with parents and children) and implementation of the "Semente" program. Methods: Participants (N = 51) were all professionals from Psychiatric Service of Fernando Fonseca Hospital who received Child Talks training. The Family-Focused Mental Health Practice Questionnaire (FFMPQ) was used to measure change in professionals' attitudes, knowledge, confidence, and organizational structure in working with these families. All participants filled in the questionnaire before training and 10 months later. Results: The results showed that, from pre- to post-measurement, the professionals changed clinical practice significantly. The largest changes were visible in the improved provision of support at the workplace for family-focused practice and the clarity and availability of the policies and procedures. Furthermore, the skill and knowledge of the mental health workers showed significant improvement at posttest. Conclusion: The positive results of this study were not unexpected; the training, implementation of routines, and procedures as well as workplace support were aims of the "Semente" program. Interpretation of the results should be taken with caution because of the small sample and the lower reliability of some of scales of the FFMPQ. The results indicate that professionals moved from patient focus to family focus during the implementation of the "Semente" program.

7.
Polymers (Basel) ; 10(8)2018 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-30960750

RESUMO

Polyurea/polyurethane (PUa/PU) shell microcapsules (MCs), containing high loadings of isophorone diisocyanate (IPDI) in the core, were developed to enable the production of mono-component, eco-friendly and safer adhesive formulations for the footwear industry. IPDI microencapsulation was obtained via oil⁻in⁻water (O/W) microemulsion combined with interfacial polymerization. A methylene diphenyl diisocyanate (MDI) compound (a commercial blend of monomeric and polymeric species), with higher reactivity than IPDI and low viscosity, was added to the O phase to competitively contribute to the shell formation, improving its quality. Four different active H sources were tested, aimed at achieving a high encapsulation yield. The successful encapsulation of IPDI was confirmed by Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), while the MCs' morphology and size distribution were assessed by scanning electron microscopy (SEM). The incorporation of a multifunctional isocyanate silane in the O phase, as "latent" active H source, led to the formation of impermeable PUa/PU-silica hybrid shell MCs with more than 60 wt.% of pure encapsulated IPDI. A proof-of-concept study shows high peeling strength and a structural type of failure of the adhesive joint, revealing an effective IPDI release. These new engineered MCs are found to be promising crosslinkers for mono-component adhesives for high demanding applications.

8.
J Curr Glaucoma Pract ; 11(2): 38-41, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28924336

RESUMO

AIM: To compare the effect of 30-gauge vs 27-gauge needle size on intraocular pressure (IOP) rise and patients' pain experience after intravitreal injection (IVI) of bevacizumab. MATERIALS AND METHODS: Cross-sectional, randomized, double-armed study. Patients were randomized to IVI with 30-gauge or 27-gauge needle. The IOP was measured pre and post IVI. Patients' pain was graded using the visual analog scale (VAS). RESULTS: A total of 54 eyes were included. The IVI caused a significant IOP rise in both groups (p < 0.001). In the 30-gauge group, the mean pre- and postinjection IOP was 16.3 ± 3.6 mm Hg and 24.1 ± 9.0 mm Hg. The corresponding figures in the 27-gauge group were 18.0 ± 2.54 (p = 0.26) and 23.1 ± 7.5 mm Hg (p = 0.66). In the 30-gauge group, the mean VAS pain score was 3.2 ± 2.6 compared to 3.0 ± 2.5 in the 27-gauge group (p = 0.78). CONCLUSION: The IVI caused a significant rise in IOP after the injection, independently of the needle size used. The 27-gauge needle coursed with lower postinjection IOP without prejudice of the patient comfort. CLINICAL SIGNIFICANCE: The IVI with 27-gauge may be considered for glaucomatous eyes (higher risk eyes), for which IOP spikes are not recommended. HOW TO CITE THIS ARTICLE: Loureiro M, Matos R, Sepulveda P, Meira D. Intravitreal Injections of Bevacizumab: The Impact of Needle Size in Intraocular Pressure and Pain. J Curr Glaucoma Pract 2017;11(2):38-41.

9.
J Glaucoma ; 26(9): 792-797, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28857943

RESUMO

PURPOSE: To compare the visibility of deep optic nerve head (ONH) structures and the visible area of the anterior surface of the lamina cribrosa (ASLC) with spectral-domain optical coherence tomography (SD-OCT) and swept-source OCT (SS-OCT). MATERIALS AND METHODS: In total, 33 glaucoma patients were imaged with SD-OCT (Spectralis, 24 radial B-scans centered on the ONH) and SS-OCT (Atlantis, 12 radial and a horizontal and vertical raster scan pattern containing 5 lines each, centered on the ONH). One of the SS-OCT horizontal and vertical scans that was best matching with the horizontal and vertical scan lines with those of SD-OCT was selected. All B-scans were then exported and deidentified. An independent observer determined whether the posterior choroid, border tissue, anterior scleral canal opening, and LC insertion into the sclera were detectable in the matched scan lines. Bruch membrane opening (BMO) and ASLC were segmented manually in radial scans. The segmented points were combined into a single plane and a linear interpolation was used to define BMO and ASLC areas. RESULTS: The posterior choroid, border tissue, and anterior scleral canal opening were detectable in most patients (94% to 100%, 88% to 100%, and 76% to 100%, respectively) and were not different between SD-OCT and SS-OCT. The LC insertion detection rate was nonstatistically higher for SS-OCT compared with SD-OCT (58% to 85% vs. 42% to 73%; P>0.10). The mean (SD) ASLC visible area (percentage of the respective BMO area) was 124 (30%) with SD-OCT and 135 (32%) with SS-OCT (P<0.01). CONCLUSION: SD-OCT and SS-OCT had comparable detection rates of deep ONH structures; however, a larger area of ASLC was visible with SS-OCT.


Assuntos
Glaucoma de Ângulo Aberto/diagnóstico por imagem , Disco Óptico/diagnóstico por imagem , Doenças do Nervo Óptico/diagnóstico por imagem , Tomografia de Coerência Óptica , Idoso , Segmento Anterior do Olho/diagnóstico por imagem , Lâmina Basilar da Corioide/diagnóstico por imagem , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Tomografia de Coerência Óptica/métodos
10.
Eur J Ophthalmol ; 27(4): 428-432, 2017 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-28009408

RESUMO

PURPOSE: To assess the impact of metabolic syndrome (MetS) on the peripapillary choroidal thickness (PPCT) and to characterize the PPCT in a Portuguese population. METHODS: This prospective study included 104 eyes. Detailed medical and ophthalmic examinations were performed; the PPCT was measured by spectral-domain optical coherence tomography (SD-OCT) using enhanced depth imaging (EDI) modality. The PPCT changes with MetS, as well as with other clinical and demographic factors, were investigated. RESULTS: The mean PPCT was 142.4 ± 54.0 µm (58-303 µm); it was thickest superiorly, followed by the temporal, nasal, and inferior sectors. The PPCT was significantly associated with axial length (p<0.001), age (p = 0.001), intraocular pressure (IOP) (p = 0.041), weight (p = 0.015), and arterial hypertension (p = 0.044). The presence of MetS was associated with thinner PPCT in all sectors, being statistically significant in the temporal (p = 0.032) and inferotemporal (p = 0.034) sectors. CONCLUSIONS: The choroidal thickness was significantly less in temporal and inferotemporal sectors in patients with MetS than in controls. This may suggest vascular insufficiency around the optic nerve head.


Assuntos
Corioide/patologia , Síndrome Metabólica/patologia , Tomografia de Coerência Óptica/métodos , Adulto , Idoso , Povo Asiático , Feminino , Humanos , Pressão Intraocular/fisiologia , Masculino , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Portugal , Estudos Prospectivos , Análise de Regressão , Tonometria Ocular , Acuidade Visual/fisiologia
11.
J Clin Diagn Res ; 10(9): ND01-ND02, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27790481

RESUMO

Ocular involvement of syphilis may occur in any stage of infection. We report a case of bilateral syphilitic chorioretinitis, in an immunocompetent patient, as the presenting feature of a tertiary syphilis we performed a multimodal characterization through Fundus Autofluorescence (FAF), Fluorescein Angiography (FA) and Spectral-Domain Optical Coherence Tomography (SD-OCT).

12.
Meat Sci ; 121: 382-389, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27449232

RESUMO

This work describes the effect of the incorporation of 1% spent yeast extract into cooked hams. Physical/chemical/sensorial characteristics and changes during 12 and 90days storage were evaluated on control and treated cooked hams processed for 1.5, 2.0, 2.5 or 3h. Spent yeast extract addition increased hardness, chewiness, ash, protein and free amino acid content. Similar volatile profiles were obtained, although there were some quantitative differences. No advantages were observed for increased cooking time. No significant differences were observed for physical and sensorial parameters of cooked hams with spent yeast extract at 12 and 90days post production, but His, aldehydes and esters increased at the end of storage. This behaviour was similar to that observed for control hams. The higher hardness of cooked ham with 1% yeast extract was due to the stronger gel formed during cooking and was maintained during storage. This additive acts as gel stabilizer for cooked ham production and could potentially improve other processing characteristics.


Assuntos
Culinária , Produtos da Carne/microbiologia , Saccharomyces cerevisiae/metabolismo , Adulto , Animais , Fenômenos Químicos , Comportamento do Consumidor , Microbiologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Pessoa de Meia-Idade , Análise de Componente Principal , Suínos , Compostos Orgânicos Voláteis/análise , Adulto Jovem
13.
Case Rep Ophthalmol Med ; 2016: 8519394, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27298747

RESUMO

Purpose. To describe a case of anterior nodular scleritis, preceded by an anterior hypertensive uveitis, which was primarily caused by varicella zoster virus (VZV). Case Report. A 54-year-old woman presented with anterior uveitis of the right eye presumably caused by herpetic viral disease and was successfully treated. Two months later, she developed a nodular scleritis and started oral nonsteroidal anti-inflammatory without effect. A complete laboratory workup revealed positivity for HLA-B27; the infectious workup was negative. Therapy was changed to oral prednisolone and an incomplete improvement occurred. Therefore, a diagnostic anterior paracentesis was performed and the polymerase chain reaction (PCR) analysis revealed VZV. She was treated with valacyclovir and the oral prednisolone began to decrease; however, a marked worsening of the scleritis occurred with the reduction of the daily dose; subsequently, methotrexate was introduced allowing the suspension of the prednisolone and led to clinical resolution of the scleritis. Conclusion. This report of anterior nodular scleritis caused by VZV argues in favor of an underlying immune-mediated component, requiring immunosuppressive therapy for clinical resolution. The PCR analysis of the aqueous humor was revealed to be a valuable technique and should be considered in cases of scleritis with poor response to treatment.

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