RESUMO

This work proposes for the first time protecting-reflecting on both sides of plated mirrors and a solution to polycarbonate surface vulnerability to weathering and scratching using tungsten disulfide (WS2) by mechanical polishing. The ability of the dynamic chemical plating (DCP) technique to deposit Ag films at the nanometer scale on a polycarbonate (PC) substrate and its characteristics to be metallized is also shown. These deposits hold significant promise for concentrated solar power (CSP) applications. Complementarily, the application of WS2 as a reflective film for CSP by mechanical polishing on smooth polycarbonate surfaces is both novel and practical. This technique is innovative and scalable without needing reactants or electrical potential, making it highly applicable in real-world scenarios, including, potentially, on-site maintenance. The effects of surface morphology and adhesion, and the reflectivity parameters of the silver metallic surfaces were investigated. Wettability was investigated because it is important for polymeric surfaces in the activation and metal deposition immediately after redox reactions. The flame technique improved wettability by modifying the surface with carbonyl and carboxyl functional groups, with PC among the few industrial polymers that resisted such a part of the process. The change in the chemical composition, roughness, and wettability of the surfaces effectively improved the adhesion between the Ag film and the PC substrate. However, it did not significantly affect the adhesion between PC and WS2 and showed its possible implementation as a first surface mirror. Overall, this work provides a scalable, innovative method for improving the durability and reflectivity of polycarbonate-based mirrors, with significant implications for CSP applications.

RESUMO

In this study, we present a novel approach for the exfoliation of titanium nitride (TiN) powders utilizing a rapid, facile, and environmentally friendly non-thermal plasma method. This method involves the use of an electric arc and nitrogen as the ambient gas at room temperature to generate ionized particles. These ionized species interact with the ceramic crystal of TiN, resulting in a pronounced structural expansion. The exfoliated TiN products were comprehensively characterized using transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Remarkably, the cubic crystal structure of TiN was effectively retained, while the (200) crystal plane d-spacing increased from 2.08 to 3.09 Å, accompanied by a reduction in crystallite size and alterations in Raman vibrational modes. Collectively, these findings provide compelling evidence for the successful exfoliation of TiN structures using our innovative non-thermal plasma method, opening up exciting possibilities for advanced material applications.

RESUMO

TiO2/C nanocomposite films were applied on water treatment. Expanded graphite nanosheets (EG) were obtained by UVC-assisted liquid-phase exfoliation technique, without the addition of acids, surfactants, or aggressive oxidizing agents, which characterizes the process as an eco-friendly method. The carbon nanosheets were synthesized directly from graphite bulk at different times and deposited on TiO2 films surface by airbrush spray coating method, forming a TiO2/C heterojunction. The increase in the exfoliation time promoted a more efficient photocatalytic dye removal under visible light. Morphological modifications, changes in the electronic structure, and wide range of light absorption were observed from the TiO2/C heterojunction formation. The results showed that hybrid TiO2/C supported photocatalyst is a promise alternative for practical photocatalytic applications under sunlight.

Assuntos

Grafite , Nanocompostos , Grafite/química , Titânio/química , Luz Solar , Nanocompostos/química

RESUMO

Objetivo: La periodontitis en dentición primaria es ex- cepcional en niños sin enfermedades sistémicas. El objetivo de este informe es describir las características clínicas y ra- diográficas de dos casos de niños de 3 años sistémicamente sanos con periodontitis, y su tratamiento con seguimiento a 5 años. Casos clínicos: En ambos casos, a los 3 años de edad los niños fueron derivados al especialista en periodoncia por su odontopediatra debido a la pérdida muy temprana de inci- sivos inferiores. El examen clínico y radiográfico mostró pér- dida de inserción clínica, pérdida ósea y movilidad dental en otros incisivos superiores e inferiores. Se realizó la intercon- sulta médica y se descartó que los niños padecieran enferme- dades relacionadas con el diagnóstico de periodontitis como manifestación de una enfermedad sistémica. El tratamiento consistió en la instrucción de medidas de higiene bucal que debían ser ejecutadas por los padres, ins- trumentación subgingival, antisépticos locales, medicación antibiótica sistémica y mantenimiento periodontal. No se rea- lizaron extracciones como parte del tratamiento. En ambos casos uno de los incisivos presentes al momento de la con- sulta se perdió prematuramente, antes de los 4 años. El resto de los incisivos primarios cumplieron su ciclo normal. Luego de 5 años de seguimiento, a la edad de 8 años, ambos niños presentaban los incisivos y los primeros molares permanentes periodontalmente sanos y el resto de los dientes primarios sin signos de periodontitis (AU)

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Aim: Periodontitis in primary dentition is exceptional in children without systemic diseases. The objective of this article is to describe the clinical and radiographic charac- teristics of two cases of systemically healthy 3-year-old chil- dren with periodontitis, and their treatment, with a 5-year follow-up. Clinical cases: In both cases, at 3 years of age, the chil- dren were referred to a periodontic specialist by their pediat- ric dentist, due to the very early loss of lower incisors. Clin- ical and radiographic examination showed loss of clinical attachment, bone loss and dental mobility in other upper and lower incisors. A medical consultation was carried out and diseases related to the diagnosis of periodontitis as a mani- festation of a systemic disease were ruled out. The treatment consisted of instruction on oral hygiene measures that had to be carried out by the parents, subgingival instrumentation, local antiseptics, systemic antibiotic medication, and perio- dontal maintenance. No extractions were performed as part of the treatment. In both cases, one of the incisors present at the time of consultation was lost prematurely, before the age of 4 years. The rest of the primary incisors completed their normal cycle. After 5 years of follow-up, at the age of 8 years, both children showed periodontally healthy incisors and first permanent molars, and the rest of the primary teeth without signs of periodontitis (AU)

Assuntos

Humanos , Masculino , Pré-Escolar , Periodontite/terapia , Periodontite/diagnóstico por imagem , Dente Decíduo/patologia , Assistência Odontológica para Crianças/métodos , Higiene Bucal/educação , Periodontite/microbiologia , Esfoliação de Dente , Seguimentos , Antibacterianos/uso terapêutico

RESUMO

Resumen Objetivo La periodontitis en dentición primaria es excepcional en niños sin enfermedades sistémicas. El objetivo de este informe es describir las características clínicas y radiográficas de dos casos de niños de 3 años sistémicamente sanos con periodontitis, y su tratamiento con seguimiento a 5 años. Casos clínicos En ambos casos, a los 3 años de edad los niños fueron derivados al especialista en periodoncia por su odontopediatra debido a la pérdida muy temprana de incisivos inferiores. El examen clínico y radiográfico mostró pérdida de inserción clínica, pérdida ósea y movilidad dental en otros incisivos superiores e inferiores. Se realizó la interconsulta médica y se descartó que los niños padecieran enfermedades relacionadas con el diagnóstico de periodontitis como manifestación de una enfermedad sistémica. El tratamiento consistió en la instrucción de medidas de higiene bucal que debían ser ejecutadas por los padres, instrumentación subgingival, antisépticos locales, medicación antibiótica sistémica y mantenimiento periodontal. No se realizaron extracciones como parte del tratamiento. En ambos casos uno de los incisivos presentes al momento de la consulta se perdió prematuramente, antes de los 4 años. El resto de los incisivos primarios cumplieron su ciclo normal. Luego de 5 años de seguimiento, a la edad de 8 años, ambos niños presentaban los incisivos y los primeros molares permanentes periodontalmente sanos y el resto de los dientes primarios sin signos de periodontitis.

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Abstract Aim Periodontitis in primary dentition is exceptional in children without systemic diseases. The objective of this article is to describe the clinical and radiographic characteristics of two cases of systemically healthy 3-year-old children with periodontitis, and their treatment, with a 5-year follow-up. Clinical cases In both cases, at 3 years of age, the children were referred to a periodontic specialist by their pediatric dentist, due to the very early loss of lower incisors. Clinical and radiographic examination showed loss of clinical attachment, bone loss and dental mobility in other upper and lower incisors. A medical consultation was carried out and diseases related to the diagnosis of periodontitis as a manifestation of a systemic disease were ruled out. The treatment consisted of instruction on oral hygiene measures that had to be carried out by the parents, subgingival instrumentation, local antiseptics, systemic antibiotic medication, and periodontal maintenance. No extractions were performed as part of the treatment. In both cases, one of the incisors present at the time of consultation was lost prematurely, before the age of 4 years. The rest of the primary incisors completed their normal cycle. After 5 years of follow-up, at the age of 8 years, both children showed periodontally healthy incisors and first permanent molars, and the rest of the primary teeth without signs of periodontitis.

RESUMO

Colombia is one of the world's leading exporters of coal and coke, with significant reserves of high-quality coal. Most of the coal exported from Colombia is used for power generation, but there is also a class of coal that is suitable for making coke. Coke is a raw material required for making steel, and it is produced by heating coal to high temperatures in the absence of air. Colombia is the third-largest global exporter of coke, with a significant portion of its exports going to the steel industry in countries such as Brazil, Mexico, and the United States. The country's high-quality coal reserves and proximity to major markets make it an important player in the global coal and coke trade. On the other hand, graphene and its derivative Graphene Oxide (GO) have unique properties that make them suitable for a wide range of commercial applications. Graphene has exceptional mechanical strength and high electrical conductivity, which make it an attractive material for a variety of electronic and structural applications. For example, graphene-based materials are being developed for use in flexible electronic devices, sensors, and high-strength composites. GO, on the other hand, is highly resistive but still retains exceptional mechanical strength. This makes it useful in applications where electrical conductivity is not necessary but mechanical strength and durability are important. Graphene production using current techniques can be expensive and inefficient, which limits its widespread adoption for commercial applications. However, new production methods, such as Liquid Phase Exfoliation (LPE), are being developed to address these challenges. LPE is a method for producing graphene and graphene oxide that involves using a liquid solvent to break apart graphite into individual graphene sheets. This method is more efficient and cost-effective than traditional methods such as mechanical exfoliation and chemical vapor deposition. In recent years, there has been increasing interest in using high-rank coal from Colombia as a raw material for graphene production using LPE. This is because high-rank coal from Colombia is known to have a high carbon content and low impurity levels, which makes it an ideal raw material for graphene production. Researchers have successfully produced GO using the LPE method and high-rank coal from Boavita, Colombia. This has the potential to significantly increase the supply of graphene and graphene oxide, making it more accessible for commercial applications. Additionally, using coal as a raw material for graphene production has the potential to create a new market for coal, which could benefit the Colombian economy. In order to synthesize GO, it is important to establish a suitable protocol for the grinding procedure and particle size selection. (i. more than 0.15 mm, ii. 0.15 mm to 0.05 mm, and iii. less than 0.05 mm) were defined. To compare the yield, the mineral matter removal procedure was carried out with a basic leaching bath. Coal oxidation was performed using the modified Hummers process, and GO was then obtained using LPE. This method has the following advantages:•It is feasible to produce GO from high-rank coal with acceptable quality and particulate size smaller than 0.15 mm, yields that are close to 5%, and flakes with fewer than 15 layers.•This approach also could eliminate dependence on graphite as the carbon feedstock for graphene production.•It is an alternative to manufacture GO from coal dust collected from mines.

RESUMO

Industrial applications of nanomaterials require large-scale production methods, such as liquid phase exfoliation (LPE). Regarding this, it is imperative to characterize the obtained materials to tailor parameters such as exfoliation medium, duration, and mechanical energy source to the desired applications. This work presents results of statistical analyses of talc flakes obtained by LPE in four different media. Talc is a phyllosilicate that can be exfoliated into nanoflakes with great mechanical properties. Sodium cholate at two different concentrations (below and at the critical micelar concentration), butanone, and Triton-X100 were employed as exfoliation medium for talc. Using recent published statistical analysis methods based on atomic force microscopy images of thousands of flakes, the shape and size distribution of nanotalc obtained using the four different media are compared. This comparison highlights the strengths and weaknesses of the media tested and hopefully will facilitate the choice of the medium for applications that have specific requirements.

RESUMO

A unique method for obtaining a mesoporous catalytic support through the exfoliation of a montmorillonite is reported. This method consisted of the intercalation of Na-clay with Al-Keggin species and polyvinyl alcohol followed by microwave irradiation. The mesoporous support was employed to prepare Ni-catalysts which were used in the natural gas synthesis through CO2 methanation. The synthesis method was validated confirming the clay exfoliation and the main formation of mesopores. Also, the Ni-catalysts have mainly weak basic surface properties lower than 38 µmol.g-1, and containing Ni0 nanoparticles with sizes between 9 and 12 nm which were thermally stable after reduction and methanation reaction. The catalyst with 5% Ni wt. gave conversions between 50 and 80% with temperatures ranging from 200 to 300 °C and selectivities of 100% towards the formation of CH4 without coke formation. The (3 and 5% Ni) Ni-catalysts are stable up to 8 h at 400 °C in the methanation reaction maintaining 100% of selectivity.•Mesoporous catalytic supports are obtained through a unique clay exfoliation method (Al-keggin, PVA, and microwaves).•(3% and 5% wt.) Ni-mesoporous catalysts are thermally stable and Ni0 nanoparticles between 9 and 12 nm are achieved.•5%wt. Ni-catalyst have no deactivation up to 8 h at 400 °C and displays unprecedented performance at low temperatures in CO2-methanation with 100% of selectivity.

RESUMO

ABSTRACT Purpose: To investigate whether pseudoexfoliation syndrome affects arterial stiffness by using cardio-ankle vascular index measurement. Methods: This cross-sectional case-control study included 55 patients with pseudoexfoliation syndrome and 106 age- and gender-matched healthy control subjects. All subjects underwent a complete ophthalmic exa mination of both eyes and cardio-ankle vascular index measu rements. Echocardiographic and body mass index measurements were performed in all patients, and the results were recorded. A binary regression model was used to determine the relationship between cardio-ankle vascular index and pseudoexfoliation. Results: There were no significant differences between the pseudoexfoliation and control groups in baseline clinical and demographic characteristics, echocardiographic measurements of left ventricular ejection fraction, and body mass index. The mean cardio-ankle vascular index value was significantly higher in the pseudoexfoliation group than in the controls (9.47 ± 1.23 vs. 8.33 ± 1.50, p<0.001). Intraocular pressure was significantly higher in the pseudoexfoliation group than in the controls (18.31 ± 1.78 vs. 15.24 ± 2.42 mm Hg, p<0.05). Although the logistic regression analysis showed that mean cardio-ankle vascular index and IOP values were positively associated with pseudoexfoliation syndrome (Odds ratios (OR) = 1.973, 95% CI, 1.051-3.706, p=0.035; OR=3.322, 95% CI = 2.000-5.520, p<0.001, respectively), the Pearson correlation analysis revealed a borderline significant positive correlation between age and mean cardio-ankle vascular index and a significant positive correlation between dyslipidemia and intraocular pressure and mean cardio-ankle vascular index (r=0.265, p=0.050; r=0.337, p=0.012; r=0.433, p=0.001, respectively). Conclusion: Our findings demonstrated that cardio-ankle vascular index values increased in patients with pseudoexfoliation syndrome.

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RESUMO Objetivo: Investigar se a síndrome de pseudoesfoliação afeta a rigidez arterial, usando a medição do índice vascular cardíaco-tornozelo. Métodos: Este estudo transversal caso-controle incluiu 55 pacientes com síndrome de pseudoesfoliação e 106 controles saudáveis, pareados por idade e gênero. Todos os indivíduos foram submetidos a um exame oftalmológico completo de ambos os olhos e à medição do índice vascular cardíaco-tornozelo. Medidas ecocardiográficas e do índice de massa corporal também foram feitas em todos os pacientes, e os resultados foram registrados. Usou-se um modelo de regressão binária para avaliar uma possível relação entre o índice vascular cardíaco-tornozelo e a pseudoesfoliação. Resultados: Não houve diferença significativa entre os grupos com pseudoesfoliação e de controle em relação às características clínicas e demográficas basais, às medidas ecocardiográficas da fração de ejeção do ventrículo esquerdo e ao índice de massa corporal. Os valores médios do índice vascular cardíaco-tornozelo foram significativamente maiores no grupo com pseudoesfoliação do que no de controle (9,47 ± 1,23 contra 8,33 ± 1,50, p<0,001). Os valores da pressão intraocular no grupo com pseudoesfoliação excederam significativamente os do grupo de controle (18,31 ± 1,78 mmHg contra 15.24 ± 2.42 mmHg, p<0.05). A análise de regressão logística demonstrou uma associação positiva das médias do índice vascular cardíaco-tornozelo e da pressão intraocular com a síndrome de pseudoesfoliação (respectivamente, OR=1,973, IC 95%: 1,051-3,706, p=0,035 e OR=3,322, IC 95%: 2,000-5,520, p<0,001). Já a análise de correlação de Pearson revelou uma correlação positiva de significância limítrofe entre a idade e a média do índice vascular cardíaco-tornozelo, e uma correlação positiva significativa entre a dislipidemia, a pressão intraocular e a média do índice vascular cardíaco-tornozelo (respectivamente, r=0,265, p=0,050; r=0,337, p=0,012; e r=0,433, p=0,001). Conclusão: Nossos achados demonstraram que os valores do índice vascular cardíaco-tornozelo se encontram aumentados em pacientes com síndrome de pseudoesfoliação.

RESUMO

Adsorption stand out among other standard techniques used for water treatment because of its remarkable simplicity, easy operation, and high removal capability. Expanded graphite has been selected as a promising agent for oil spill adsorption, but its production involves the generation of corrosive remnants and massive amounts of contaminated washing waters. Although the advantageous use of the H2O2-H2SO4 mixture was described in 1978, reported works using this method are scarce. This work deals with the urgent necessity for the development of alternative chemical routes decreasing their environmental impact (based on green chemistry concepts), presenting a process for expanded graphite production using only two intercalation chemicals, reducing the consumption of sulfuric acid to only 10% and avoiding the use of strong oxidant salts (both environmentally detrimental). Three process parameters were evaluated: milling effect, peroxide concentration, and microwave expansion. Some remarkable results were obtained following this route: high specific volumes elevated oil adsorption rate exhibiting a high oil-water selectivity and rapid adsorption. Furthermore, the recycling capability was checked using up to six adsorption cycles. Results showed that milling time reduces the specimen's expansion rate and oil adsorption capacity due to poor intercalant insertion and generation of small particle sizes.

Assuntos

Grafite , Poluição por Petróleo , Poluentes Químicos da Água , Peróxido de Hidrogênio , Poluentes Químicos da Água/análise , Adsorção

RESUMO

ABSTRACT Purpose: To investigate inter-eye retinal vessel density and thickness asymmetry in unilateral pseudoexfoliation syndrome and understand its use for the early detection of glaucoma. Methods: Thirty patients with unilateral pseudoexfoliation syndrome were enrolled in our study. Optical coherence tomography angiography macular scans were used measure the retinal vessel density, and optical coherence tomography scans were used to assess the thickness parameters of the peripapillary retinal nerve fiber layer and the macular ganglion cell complex. Inter-eye asymmetry was determined by taking the absolute value of the difference in the vessel density and thickness parameters between the pseudoexfoliation syndrome eye and fellow eye. Results: The mean patient age was 64.20 ± 7.05 y in the study group. Inter-eye asymmetry in the peripapillary retinal nerve fiber layer thickness and macular ganglion cell complex measurements were significant in the study group (p=0.03 and p=0.001, respectively). The vessel density of the macular superficial inner region was significantly lower in eyes with pseudoexfoliation syndrome than in fellow eyes (p=0.035). However, there was no inter-eye asymmetry in the central and full region macular superficial vessel density of eyes with pseudoexfoliation syndrome and fellow eyes (p>0.05). Conclusion: Retinal vessel density can be evaluated using optical coherence tomography angiography measurements. There was inter-eye asymmetry in the inner region macular superficial vessel density, peripapillary retinal nerve fiber layer, and macular ganglion cell complex thickness of the unilateral pseudoexfoliation syndrome eyes and fellow eyes. Further studies on a larger number of subjects might provide more clarity regarding the relationship between the inter-eye asymmetry of the retinal vessel density and thickness parameters with early detection of glaucomatous damage.

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RESUMO Objetivo: Investigar a densidade dos vasos interoculares da retina e assimetria na espessura na síndrome de pseudoexfoliação unilateral e o seu uso para a detecção precoce de glaucoma. Métodos: Trinta pacientes com síndrome de pseudoexfoliação unilateral foram incluídos no estudo. As varreduras maculares de angiografia por tomografia de coerência óptica mediram a densidade dos vasos da retina, e as varreduras por tomografia de coerência óptica obtiveram parâmetros de espessura da camada de fibras nervosas da retina peripapilar e do complexo macular de célula ganglionar. A assimetria interocular foi determinada tomando o valor absoluto da diferença entre o olho da síndrome de pseudoexfoliação e o olho oposto nos parâmetros de densidade e espessura dos vasos. Resultados: A média de idade foi 64,20 ± 7,05 anos no grupo de estudo. A assimetria interocular na espessura da camada de fibra nervosa da retina peripapilar e as medidas do complexo macular de célula ganglionar foram estatisticamente significativas no grupo de estudo (p=0,03 e p=0,001, respectivamente). Para os olhos com síndrome de pseudoexfoliação, a densidade do vaso da região macular superficial interna foi significativamente menor do que em olhos opostos (p=0,035). No entanto, não houve assimetria interocular estatisticamente significativa na densidade macular dos vasos superficiais da região central e completa entre os olhos da síndrome de pseudoexfoliação e os olhos opostos (p>0,05). Conclusões: A densidade dos vasos da retina pode ser avaliada por medidas de angiografia por tomografia de coerência óptica. Houve assimetria interocular na densidade macular do vaso superficial da região interna, camada de fibra nervosa da retina peripapilar e espessura do complexo macular de célula ganglionar entre olhos com síndrome de pseudoexfoliação unilateral e olhos opostos. Novos estudos com um número maior de indivíduos podem fornecer a relação entre a assimetria interocular da densidade do vaso da retina e os parâmetros de espessura com detecção precoce de dano glaucomatoso.

RESUMO

ABSTRACT Purpose: This study aimed to compare the vessel density of the optic nerve head and radial peripapillary capillary in the eyes with early-stage primary open angle glaucoma and pseudoexfoliation glaucoma and control eyes. Methods: With visual field mean deviation scores >-6.0 dB, 54 eyes from 37 patients diagnosed with primary open angle glaucoma (n=18) and pseudoexfoliation glaucoma (n=18) and healthy controls (n=18) were enrolled in this cross-sectional observational study. Retrieved from optical coherence tomography angiography, vessel density for the optic nerve head and radial peripapillary capillary were analyzed according to the distribution of the data and appropriate tests. The diagnostic accuracy of vessel density parameters was also assessed. Results: The whole-image vessel density of the radial peripapillary capillary and inside-disc vessel density of the optic nerve head were significantly lower in eyes with primary open angle glaucoma and pseudoexfoliation glaucoma compared to those in the control eyes (p<0.05). Compared to that in pseudoexfoliation glaucoma, the inside-disc vessel density of the optic nerve head was significantly lower in primary open angle glaucoma (p<0.05). Inferotemporal sector vessel density of the optic nerve head for both primary open angle glaucoma and pseudoexfoliation glaucoma was significantly lower than that of the controls (p=0.009). In discrimination of primary open angle glaucoma vs. control and pseudoexfoliation glaucoma vs. control, area under the receiver operating characteristic curve values for inside-disc vessel density of the optic nerve head were 0.855 and 0.731, respectively (p<0.001, p=0.018). However, in discrimination of primary open angle glaucoma vs. pseudoexfoliation glaucoma, area under the receiver operating characteristic curve values for whole-image and inside-disc vessel densities of the optic nerve head were 0.707 and 0.722 (p=0.034, p=0.023). Conclusions: Vessel densities of the optic nerve head and radial peripapillary capillary were significantly lower in eyes with primary open angle glaucoma and pseudoexfoliation glaucoma compared to healthy control eyes. In the early stage of glaucoma, the inside-disc vessel density of the optic nerve head slab may be lower in eyes with primary open angle glaucoma eyes compared to eyes with pseudoexfoliation glaucoma.

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RESUMO Objetivo: Comparar a densidade vascular da cabeça do nervo óptico e a densidade capilar peripapilar radial em olhos em estágios iniciais de glaucoma primário de ângulo aberto e com glaucoma pseudoesfoliativo, bem como em olhos controle. Métodos: Este é um estudo observacional transversal, no qual foram incluídos 54 olhos com valores de desvio médio do campo visual superiores a -6,0 dB. Os olhos incluídos eram de 37 pacientes, diagnosticados com glaucoma primário de ângulo aberto (n=18), glaucoma pseudoesfoliativo (n=18) e controles saudáveis (n=18). Os valores de densidade vascular da cabeça do nervo óptico e a densidade capilar peripapilar radial foram obtidos a partir de angiografias por tomografia de coerência óptica, analisados de acordo com a distribuição dos dados e submetidos a testes estatísticos apropriados. Também foi avaliada a precisão diagnóstica dos parâmetros de densidade vascular. Resultados: Os valores para a densidade capilar peripapilar radial e no interior do disco óptico nas imagens inteiras foram significativamente menores no glaucoma primário de ângulo aberto e no glaucoma pseudoesfoliativo do que no grupo controle (p<0,05). A densidade vascular no interior do disco óptico na cabeça do nervo óptico foi significativamente menor no glaucoma primário de ângulo aberto do que no glaucoma pseudoesfoliativo (p<0,05). A densidade vascular no setor temporal inferior da cabeça do nervo óptico foi significativamente menor tanto no glaucoma primário de ângulo aberto quanto no glaucoma pseudoesfoliativo, em comparação com o grupo controle (p=0,009). A área abaixo da curva de ROC para a densidade vascular no interior do disco óptico na cabeça do nervo óptico, foi de 0,855 para a comparação do glaucoma primário de ângulo aberto com o controle (p<0,001) e de 0,731 para a comparação do glaucoma pseudoesfoliativo com o controle (p=0,018). Porém, na comparação do glaucoma primário de ângulo aberto com o glaucoma pseudoesfoliativo, os valores da área abaixo da curva de ROC para a densidade vascular na imagem inteira e no interior do disco óptico na cabeça do nervo óptico foram respectivamente de 0,707 e 0,722 (p=0,034, p=0,023). Conclusões: A densidade vascular na cabeça do nervo óptico e a densidade capilar peripapilar radial mostraram-se significativamente diminuídas no glaucoma primário de ângulo aberto e no glaucoma pseudoesfoliativo, em comparação com olhos controle saudáveis. Nos estágios iniciais do glaucoma, a densidade vascular no interior do disco óptico, na cabeça do nervo óptico, pode ser menor em olhos com glaucoma primário de ângulo aberto do que em olhos com glaucoma pseudoesfoliativo.

Assuntos

Humanos , Disco Óptico , Glaucoma , Glaucoma de Ângulo Aberto , Disco Óptico/diagnóstico por imagem , Vasos Retinianos , Angiofluoresceinografia , Glaucoma de Ângulo Aberto/diagnóstico por imagem , Estudos Transversais , Tomografia de Coerência Óptica , Pressão Intraocular

RESUMO

ABSTRACT Pseudoexfoliation syndrome is more frequent in people aged >50 yeears, and its prevalence increases with age. Few reports have described cases in younger patients, all with a history of ocular surgery, especially iris resection. Herein, we describe the case of a 27-year old man with bilateral advanced glaucoma and pseudoexfoliation material in OS. He had undergone cataract surgeries OU and a penetrating keratoplasty OD during childhood. Currently, he presented with an intraocular pressure of 40 mmHg OU. The OS showed a white flaky material in the pupillary rim and anterior capsule and a Sampaolesi line as a gonioscopic finding. Trabeculectomy was performed OU, and intraocular pressure control was achieved. Unlike other previously reported cases, this patient did not present any apparent iris manipulation in the affected eye. However, he did undergo an iridectomy in the contralateral eye. This is also the first case to be accompanied by bilateral glaucoma at the time of detection of the pseudoexfoliation material.(AU)

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RESUMO A síndrome de pseudoesfoliação é mais frequente em pessoas com mais de 50 anos e sua prevalência aumenta com a idade. Poucos relatos descrevem casos em pacientes mais jovens, todos com história de cirurgia ocular, especialmente ressecção da íris. Descrevemos o caso de um homem de 27 anos com glaucoma bilateral avançado e material de pseudoesfoliação no OE. O paciente foi submetido a cirurgias de catarata em AO e a uma ceratoplastia penetrante no OD durante a infância. Atualmente, ele apresentou PIOs de 40 mmHg em AO. O OE apresentou material escamoso branco na borda pupilar e cápsula anterior, e linha Sampaolesi como achado gonioscópico. A trabeculectomia foi realizada em AO e obteve-se o controle da pressão intraocular. Diferentemente de outros casos relatados, o paciente não apresentou qualquer manipulação aparente da íris no olho afetado. No entanto, ele foi submetido a uma iridectomia no olho contralateral. Além disso, este é o primeiro caso a ser acompanhado de glaucoma bilateral no momento da detecção do material de pseudoesfoliação.(AU)

Assuntos

Humanos , Adulto , Extração de Catarata , Glaucoma/complicações , Síndrome de Exfoliação/fisiopatologia , Iridectomia/instrumentação

RESUMO

A simple, efficient, environmentally friendly, and inexpensive synthesis route was developed to obtain a magnetic nano-hybrid (GH) based on graphene and cobalt ferrite. Water with a high content of natural organic matter (NOM) was used as solvent and a source of carbon. The presence of NOM in the composition of GH was confirmed by FTIR and Raman spectroscopy, which evidenced the formation of graphene, as also corroborated by XRD analyses. The diffractograms and TEM images showed the formation of a hybrid nanomaterial composed of graphene and cobalt ferrite, with crystallite and particle sizes of 0.83 and 4.0 nm, respectively. The heterogeneous electro-Fenton process (EF-GH) achieved 100% degradation of bisphenol A (BPA) in 50 min, with 80% mineralization in 7 h, at pH 7, using a current density of 33.3 mA cm-2. The high catalytic performance was achieved at neutral pH, enabling substantial reduction of the costs of treatment processes. This work contributes to understanding the role of NOM in the synthesis of a magnetic nano-hybrid based on graphene and cobalt ferrite, for use in heterogeneous catalysis. This nano-hybrid has excellent potential for application in the degradation of persistent organic pollutants found in aquatic environments.

Assuntos

Grafite , Poluentes Químicos da Água , Compostos Benzidrílicos , Catálise , Cobalto , Compostos Férricos , Peróxido de Hidrogênio , Ferro , Oxirredução , Fenóis , Poluentes Químicos da Água/análise

RESUMO

Abstract There is a great interest to use carbon-based material like graphene and graphene oxide in biomedical applications due to its flexibility to be functionalized with bio-active molecules. Herein, graphene and graphene-based nanocomposites were biosynthesized by liquid-phase exfoliation of graphite using aqueous extract of Parthenium hysterophorous (P-H) as a surfactant. A set of five thin film samples of graphene was prepared from graphene suspension by vacuum filtration method. Samples were characterized by UV-vis spectroscopy, Raman spectroscopy, SEM, and XRD, which revealed successful synthesis of graphene. Graphene/P-H(G/P-H) nanocomposites comprising varied ratios of graphene and P-H were prepared and their antibacterial activity was investigated by agar well diffusion method. The experimental results indicated that G/P-H nanocomposite have higher antibacterial activity than graphene alone, and bioactivity of G/P-H nanocomposite was found to be controlled by the fraction of graphene in the composite.

RESUMO

Introduction: Pseudoexfoliation Syndrome (PEX) is a genetic-inherited disorder, consisting of the deposition of elastin microfibers in intra and extraocular tissue. PEX is one of the most common identifiable secondary causes of glaucoma. Several studies have associated PEX with systemic conditions and the finding of fibrillar material in the structures of the inner ear, similar to that of pseudoexfoliation detected in the eye, has been described. Objective: to compare audiometric levels in patients with and without ocular PEX. Materials and Methods: Retrospective case-control study. 48 medical records of patients who attended the ophthalmology service of the Private Hospital of Córdoba were selected between January 2015 and December 2017, between 59 and 75 years. They were divided into groups: controls (n = 22): without PEX and cases (n = 26): with PEX. The medical records of patients who underwent ophthalmological and audiometric studies were analyzed. For the statistical analysis, the Student's T test was used for independent and paired samples; in all cases a level of significance ≤ 0.05 was considered. Results: The percentage of hearing loss was 56.8% in the control group and 82.7% in the PEX group. The percentage disability in the group with PEX was greater in monaural (p = 0.0008) and biaural (p = 0.0307) hearing compared to patients without PEX. Conclusion: Patients with ocular PEX showed a higher percentage of hearing loss, compared to those patients without ophthalmic evidence of PEX.

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Introducción: El Síndrome de Pseudoexfoliación (PEX) es un trastorno genético-hereditario, consiste en el depósito de microfibras de elastina en tejido intra y extraocular. El PEX es una de las causas secundarias identificables más comunes del glaucoma. Varios estudios han asociado el PEX con afecciones sistémicas y se ha descripto el hallazgo de material fibrilar en las estructuras del oído interno, similares al de pseudoexfoliación detectado en el ojo. Objetivo: comparar los niveles de audiométricos en pacientes con y sin PEX ocular. Materiales y Métodos: Estudio retrospectivo de casos y controles. Se seleccionaron 48 historias clínicas de pacientes que asistieron al servicio de oftalmología del Hospital Privado de Córdoba, entre enero del 2015 y diciembre de 2017, de entre 59 y 75 años. Se los dividió en grupos: controles (n=22): sin PEX y casos (n=26): con PEX. Se analizaron las historias clínicas de pacientes a los que se les realizaron estudios oftalmológicos y audiométricos. Para el análisis estadístico se utilizó el test T de Student para muestras independientes y apareadas; en todos los casos se consideró un nivel de significación ≤ 0.05. Resultados: El porcentaje de pérdida auditiva fue del 56,8% en el grupo control y un 82,7% en el grupo PEX. La incapacidad porcentual en el grupo con PEX fue mayor en la audición monoaural (p=0,0008) y biaural (p=0,0307) con respecto a los pacientes sin PEX. Conclusión: Los pacientes con PEX ocular mostraron un porcentaje mayor de hipoacusia, en comparación con aquellos pacientes sin evidencia oftalmológica de PEX.

Assuntos

Síndrome de Exfoliação/complicações , Perda Auditiva Neurossensorial/etiologia , Idoso , Audiometria , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Tonometria Ocular

RESUMO

ABSTRACT Purpose: To assess the relationship between pseudoexfoliation syndrome and incidence of complications and related clinical factors in patients undergoing cataract surgery. Methods: We conducted a retrospective cohort study of 503 of 551 patients who underwent phacoemulsification surgery over 2 years in a health care district in Northwest Spain. In total, 120 of 681 eyes undergoing the procedure had pseudoexfoliation syndrome. Data on the surgical procedure and associated complications were extracted from the medical record. Complications included any combination of posterior capsular rupture, vitreous loss, zonular dialysis, and nuclear or lens luxation. Results: We found a significant association between pseudoexfoliation syndrome and zonular dialysis (odds ratio [OR], 6.89; 95% CI, 2.27-20.93), intraoperative miosis (OR, 2.15; 95% CI, 1.10-4.22), and lens luxation >1.5 mm (OR, 9.49; 95% CI, 0.85-105.54). However, when adjusting for the overall risk of complications in pseudoexfoliation syndrome patients in consideration of myopia, use of anticoagulants or α-agonists, previous mydriasis, and anterior chamber length, the OR decreased to 1.02 (95% CI, 0.47-2.21) and was therefore not significant. Conclusion: Zonular dialysis and intraoperative miosis were intraoperative complications in cataract surgery patients with pseudoexfoliation syndrome when compared to controls.

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RESUMO Objetivo: Avaliar a relação entre a síndrome de pseudoexfoliação e a prevalência de complicações e fatores clínicos relacionados em pacientes submetidos à cirurgia de catarata. Métodos: Foi realizado um estudo retrospectivo de coorte de 503 de 551 pacientes que se submeteram à cirurgia de facoemulsificação durante 2 anos em um distrito de saúde no noroeste da Espanha. No total, 120 dos 681 olhos submetidos ao procedimento apresentavam síndrome de pseudoexfoliação. Dados sobre o procedimento cirúrgico e complicações associadas foram obtidos dos prontuários médicos. As complicações incluíram qualquer combinação de ruptura da cápsula posterior, perda de humor vítreo, diálise zonular e luxação do núcleo ou do cristalino. Resultados: Encontramos uma associação significativa entre síndrome de pseudoexfoliação e diálise zonular (razão de probabilidade [RP]: 6,89; IC 95%, 2,27-20,93), a miose perioperatória (RP: 2,15; IC 95%, 1,10-4,22) e luxação do cristalino >1,5 mm (RP: 9,49; IC 95%, 0,85-105,54). Porém, ao ajustar para o risco global de complicações em pacientes com síndrome de pseudoexfolição em consideração à miopia, uso de anticoagulantes ou α-agonistas, midríase prévia e comprimento da câmara anterior, a RP diminuiu para 1,02 (IC 95%, 0,47-2,21) e não foi, portanto, significativo. Conclusão: A diálise zonular e a miose intraoperatória foram complicações intraoperatórias em pacientes submetidos à cirurgia de catarata com síndrome de pseudoexfoliação quando comparados aos controles.

Assuntos

Humanos , Masculino , Feminino , Idoso , Idoso de 80 Anos ou mais , Catarata/complicações , Síndrome de Exfoliação/complicações , Facoemulsificação/efeitos adversos , Complicações Intraoperatórias/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Espanha/epidemiologia , Fatores de Tempo , Catarata/fisiopatologia , Catarata/epidemiologia , Acuidade Visual , Modelos Logísticos , Prevalência , Estudos Retrospectivos , Fatores de Risco , Seguimentos , Síndrome de Exfoliação/fisiopatologia , Síndrome de Exfoliação/epidemiologia , Estatísticas não Paramétricas

RESUMO

ABSTRACT Purpose: To investigate the effect of pseudoex foliation syndrome on choroidal thickness as compared with healthy individuals and subjects with primary open-angle glaucoma. Methods: This prospective, randomized study included 30 primary open angle glaucoma patients and 30 pseudoexfoliation glaucoma patients with similar demographic characteristics and 30 eyes of 30 healthy individuals comprised the control group. Regular optic nerve and macular images were obtained using a Cirrus HD spectral domain optical coherence tomography instrument, along with macular choroidal thickness measurements with enhanced depth imaging mode. Results: Age, sex, and axial length values were similar among the three groups (p>0.05). The primary open angle glaucoma and pseudoexfoliation glaucoma groups had comparable levels of glaucomatous damage. The mean subfoveal choroidal thickness values in the primary open angle glaucoma, pseudoexfoliation glaucoma, and control groups were 271.80 ± 19.96 μm, 241.43 ± 32.47 μm, and 268.03 ± 24.50 μm, respectively. The pseudoexfoliation glaucoma group had the lowest choroidal thickness values of the three groups (p values: pseudoexfoliation-control: 0.001; pseudoexfoliation-primary open angle glaucoma: <0.001, primary open angle glaucoma-control: 0.516, independent samples t-test). Conclusion: The macular choroid was thinner in patients with pseudoexfoliation glaucoma, as compared with both healthy individuals and open-angle glaucoma patients with similar degrees of glaucomatous damage.

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RESUMO Objetivo: Investigar o efeito do glaucoma pseudoexfoliativo sobre a espessura da coroide em comparação com indivíduos saudáveis e com glaucoma primário de ângulo aberto. Métodos: Este estudo prospectivo e randomizado incluiu 30 pacientes com glaucoma primário de ângulo aberto e 30 com glaucoma pseudoexfoliativo, com características demográficas semelhantes e 30 olhos de 30 indivíduos saudáveis compuseram o grupo controle. Imagens da área macular e do nervo óptico foram obtidas usando um tomógrafo por coerência óptica no domínio espectral do modelo Cirrus HD, juntamente com medições da espessura da coroide na área macular através do modo de imagem de profundidade realçada. Resultados: Os valores de idade, sexo e comprimento axial foram semelhantes nos três grupos (p>0,05). Os grupos de glaucoma primário de ângulo aberto e de glaucoma pseudoexfoliativo tinham níveis comparáveis de lesões glaucomatosas. Os valores médios da espessura subfoveal da coroide nos grupos do glaucoma primário de ângulo aberto, glaucoma pseudoexfoliativo e de controle foram 271,80 ± 19,96 μm, 241,43 ± 32,47 μm e 268,03 ± 24,50 μm, respectivamente. O grupo glaucoma pseudoexfoliativo apresentou os menores valores de espessura de coroide dos três grupos (valores de p: pseudoexfoliativo-controle: 0,001; pseudoexfoliativo-glaucoma primário de ângulo aberto: <0,001, controle de glaucoma primário de ângulo aberto: 0,516; teste de t de amostras independentes). Conclusão: A coroide na área macular era mais fina em pacientes com glaucoma pseudoexfoliativo, quando comparada com indivíduos saudáveis e pacientes com glaucoma de ângulo aberto com graus similares de lesão glaucomatosa.

Assuntos

Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Glaucoma de Ângulo Aberto/patologia , Corioide/patologia , Síndrome de Exfoliação/patologia , Estudos de Casos e Controles , Estudos Prospectivos , Tomografia de Coerência Óptica , Comprimento Axial do Olho , Pressão Intraocular

RESUMO

Herein we describe a successful protocol for graphite exfoliation using a biphasic liquid system (water/dichloromethane, DCM) containing ionic liquids (ILs; 1,3-dibenzylimidazolium benzoate- and 1-naphthoate). The use of (surface active) IL and sonication led to stable DCM/water (O/W) emulsion, which enhanced graphene formation, suppressed its re-aggregation and decreased shear/cavitation damage. The O/W emulsion stabilization by the ILs was studied by dynamic light scattering (DLS), whereas their interaction with the graphene sheets were described by Density Functional Theory (DFT) calculations. Moreover, a comprehensive investigation on cavitation-based exfoliation in the O/W systems was performed to assess the importance of operational parameters, including, the type of ultrasound processor, ultrasound power and insonation, and the influence of the exfoliation medium.

RESUMO

Se presenta el caso de una mujer de 81 años que acude para valoración de cirugía de catarata en el ojo derecho. El examen biomicroscópico revela la existencia de una catarata C2N4 (Lens Opacities Classifi cation System, versión III) con una cápsula anterior que en su región central pareciera estar abierta a modo de capsulorrexis, aunque sin trasvase de material lenticular ni signos inflamatorios en cámara anterior Figura 1. Su consistencia y morfología nos hacen pensar en un posible desdoblamiento idiopático de la cristaloides anterior, ya que tanto el reborde pupilar como la gonioscopia son rigurosamente normales. De ahí nuestro título de "pseudocapsulorrexis".

Assuntos

Capsulorrexe , Extração de Catarata , Cristalino/diagnóstico por imagem