RESUMO

La contaminación de las áreas de preparación al entrar en contacto con los alimentos crudos o cocinados, es por esto que una de las principales causas de la contaminación de las superficies inertes es la inadecuada manipulación de los alimentos a la hora de ser preparados. Con el objetivo de controlar la aplicación de normas de higiene en las áreas de preparación y consumo de alimentos mediante análisis microbiológicos para disminuir los riesgos de contaminación alimentaria. Esta investigación es de carácter descriptivo, en la cual se realizó una inspección visual del establecimiento con el propósito de evaluar las condiciones higiénicas sanitarias, mediante la aplicación de la Guía Técnica para el Análisis Microbiológico de Superficies en contacto con Alimentos y Bebidas. Para el análisis microbiológico de las muestras se emplearon las técnicas de inoculación, método de estriado, aislamiento bacteriano, tinción diferencial y utilización de las pruebas bioquímicas como: TSI, SIM, Citrato de Simmons, Urea, Lisina, Catalasa y Oxidasa, además de la utilización de medios de cultivo selectivo y diferencial como agar EMB y agar MacConkey para la identificación de bacterias entéricas como: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. Los resultados arrojaron que la frecuencia bacteriana de las superficies inertes de los restaurantes en el área de preparación de alimentos (mesón y tabla de picar) tienen presencia de bacterias: Salmonella con mayor frecuencia; E. coli, Klebsiella pneumoniae y Pseudomonas aeruginosa de mediana frecuencia y de baja para Shigella, y en el área de consumo de alimentos (mesas) la bacteria de mayor frecuencia es la E. coli y Shigella, la Klebsiella pneumoniae de mediana y Pseudomona aeruginosa se encuentra en baja frecuencia. Se llegó a la conclusión que las superficies inertes tanto en el área de preparación como en el área de consumo de alimentos se encuentran contaminados por lo que hay un riesgo de infección alimentaria para los comensales de la Universidad Técnica de Machala.

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Contamination of preparation areas when coming into contact with raw or cooked foods, which is why one of the main causes of contamination of inert surfaces is inadequate handling of food when it is being prepared. With the aim of controlling the application of hygiene standards in the areas of food preparation and consumption through microbiological analysis to reduce the risks of food contamination. This research is descriptive in nature, in which a visual inspection of the establishment was carried out with the purpose of evaluating the sanitary and hygienic conditions, through the application of the Technical Guide for the Microbiological Analysis of Surfaces in Contact with Food and Beverages. For the microbiological analysis of the samples, inoculation techniques, streaking method, bacterial isolation, differential staining and use of biochemical tests such as: TSI, SIM, Simmons Citrate, Urea, Lysine, Catalase and Oxidase, in addition to use of selective and differential culture media such as EMB agar and MacConkey agar for the identification of enteric bacteria such as: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. The results showed that the bacterial frequency of the inert surfaces of the restaurants in the food preparation area (counter and cutting board) have the presence of bacteria: Salmonella more frequently; E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa of medium frequency and low frequency for Shigella, and in the food consumption area (tables) the most frequent bacteria are E. coli and Shigella, Klebsiella pneumoniae of medium and Pseudomona aeruginosa It is at low frequency. It was concluded that the inert surfaces in both the preparation area and the food consumption area are contaminated, so there is a risk of food infection for diners at the Technical University of Machala.

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Contaminação das áreas de preparo ao entrar em contato com alimentos crus ou cozidos, por isso uma das principais causas de contaminação de superfícies inertes é o manuseio inadequado dos alimentos no momento do preparo. Com o objetivo de controlar a aplicação de padrões de higiene nas áreas de preparação e consumo de alimentos através de análises microbiológicas para reduzir os riscos de contaminação alimentar. Esta pesquisa é de natureza descritiva, na qual foi realizada uma inspeção visual do estabelecimento com a finalidade de avaliar as condições sanitárias e higiênicas, por meio da aplicação do Guia Técnico para Análise Microbiológica de Superfícies em Contato com Alimentos e Bebidas. Para a análise microbiológica das amostras foram utilizadas técnicas de inoculação, método de estrias, isolamento bacteriano, coloração diferencial e utilização de testes bioquímicos como: TSI, SIM, Citrato de Simmons, Ureia, Lisina, Catalase e Oxidase, além de utilização de testes seletivos e diferenciais. meios de cultura como ágar EMB e ágar MacConkey para identificação de bactérias entéricas como: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. Os resultados mostraram que a frequência bacteriana das superfícies inertes dos restaurantes na área de preparo de alimentos (balcão e tábua de corte) apresentam com maior frequência a presença de bactérias: Salmonella; E. coli, Klebsiella pneumoniae e Pseudomonas aeruginosa de média frequência e baixa frequência para Shigella, e na área de consumo alimentar (tabelas) as bactérias mais frequentes são E. coli e Shigella, Klebsiella pneumoniae de média e Pseudomona aeruginosa Está em baixa frequência . Concluiu-se que as superfícies inertes tanto na área de preparação como na área de consumo de alimentos estão contaminadas, pelo que existe risco de infecção alimentar para os comensais da Universidade Técnica de Machala.

RESUMO

It is well known that Hirshfeld surfaces provide an easy and straightforward way of analysing intermolecular interactions in the crystal environment. The use of atomic Hirshfeld surfaces has also demonstrated that such surfaces carry information related to chemical bonds which allow a deeper evaluation of the structures. Here we briefly summarize the approach of atomic Hirshfeld surfaces while further evaluating the kind of information that can be retrieved from them. We show that the analysis of the metal-centre Hirshfeld surfaces from structures refined via Hirshfeld Atom Refinement (HAR) allow accurate evaluation of contacts of type M...H, and that such contacts can be related to the overall shape of the surfaces. The compounds analysed were tetraaquabis(3-carboxypropionato)metal(II), [M(C4H3O4)2(H2O)4], for metal(II)/M = manganese/Mn, cobalt/Co, nickel/Ni and zinc/Zn. We also evaluate the sensitivity of the surfaces by an investigation of seemingly flat surfaces through analysis of the curvature functions in the direction of C-C bonds. The obtained values not only demonstrate variations in curvature but also show a correlation with the hybridization of the C atoms involved in the bond.

RESUMO

Chalcopyrite, the world's primary copper ore mineral, is abundant in Latin America. Copper extraction offers significant economic and social benefits due to its strategic importance across various industries. However, the hydrometallurgical route, considered more environmentally friendly for processing low-grade chalcopyrite ores, remains challenging, as does its concentration by froth flotation. This limited understanding stems from the poorly understood structure and reactivity of chalcopyrite surfaces. This study reviews recent contributions using density functional theory (DFT) calculations with periodic boundary conditions and slab models to elucidate chalcopyrite surface properties. Our analysis reveals that reconstructed surfaces preferentially expose S atoms at the topmost layer. Furthermore, some studies report the formation of disulfide groups (S22-) on pristine sulfur-terminated surfaces, accompanied by the reduction of Fe3+ to Fe2+, likely due to surface oxidation. Additionally, Fe sites are consistently identified as favourable adsorption locations for both oxygen (O2) and water (H2O) molecules. Finally, the potential of computer modelling for investigating collector-chalcopyrite surface interactions in the context of selective froth flotation is discussed, highlighting the need for further research in this area.

RESUMO

This study delves into the potential of amorphous titanium oxide (aTiO2) nano-coating to enhance various critical aspects of non-Ti-based metallic orthopedic implants. These implants, such as medical-grade stainless steel (SS), are widely used for orthopedic devices that demand high strength and durability. The aTiO2nano-coating, deposited via magnetron sputtering, is a unique attempt to improve the osteogenesis, the inflammatory response, and to reduce bacterial colonization on SS substrates. The study characterized the nanocoated surfaces (SS-a TiO2) in topography, roughness, wettability, and chemical composition. Comparative samples included uncoated SS and sandblasted/acid-etched Ti substrates (Ti). The biological effects were assessed using human mesenchymal stem cells (MSCs) and primary murine macrophages. Bacterial tests were carried out with two aerobic pathogens (S. aureusandS. epidermidis) and an anaerobic bacterial consortium representing an oral dental biofilm. Results from this study provide strong evidence of the positive effects of the aTiO2nano-coating on SS surfaces. The coating enhanced MSC osteoblastic differentiation and exhibited a response similar to that observed on Ti surfaces. Macrophages cultured on aTiO2nano-coating and Ti surfaces showed comparable anti-inflammatory phenotypes. Most significantly, a reduction in bacterial colonization across tested species was observed compared to uncoated SS substrates, further supporting the potential of aTiO2nano-coating in biomedical applications. The findings underscore the potential of magnetron-sputtering deposition of aTiO2nano-coating on non-Ti metallic surfaces such as medical-grade SS as a viable strategy to enhance osteoinductive factors and decrease pathogenic bacterial adhesion. This could significantly improve the performance of metallic-based biomedical devices beyond titanium.

Assuntos

Materiais Revestidos Biocompatíveis , Macrófagos , Teste de Materiais , Células-Tronco Mesenquimais , Osteogênese , Aço Inoxidável , Propriedades de Superfície , Titânio , Titânio/química , Aço Inoxidável/química , Animais , Humanos , Células-Tronco Mesenquimais/citologia , Camundongos , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Macrófagos/metabolismo , Osteogênese/efeitos dos fármacos , Diferenciação Celular , Próteses e Implantes , Osteoblastos/citologia , Staphylococcus aureus/efeitos dos fármacos , Biofilmes , Staphylococcus epidermidis/efeitos dos fármacos , Aderência Bacteriana , Molhabilidade

RESUMO

La contaminación de las áreas de preparación al entrar en contacto con los alimentos crudos o cocinados, es por esto que una de las principales causas de la contaminación de las superficies inertes es la inadecuada manipulación de los alimentos a la hora de ser preparados. Con el objetivo de controlar la aplicación de normas de higiene en las áreas de preparación y consumo de alimentos mediante análisis microbiológicos para disminuir los riesgos de contaminación alimentaria. Esta investigación es de carácter descriptivo, en la cual se realizó una inspección visual del establecimiento con el propósito de evaluar las condiciones higiénicas sanitarias, mediante la aplicación de la Guía Técnica para el Análisis Microbiológico de Superficies en contacto con Alimentos y Bebidas. Para el análisis microbiológico de las muestras se emplearon las técnicas de inoculación, método de estriado, aislamiento bacteriano, tinción diferencial y utilización de las pruebas bioquímicas como: TSI, SIM, Citrato de Simmons, Urea, Lisina, Catalasa y Oxidasa, además de la utilización de medios de cultivo selectivo y diferencial como agar EMB y agar MacConkey para la identificación de bacterias entéricas como: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. Los resultados arrojaron que la frecuencia bacteriana de las superficies inertes de los restaurantes en el área de preparación de alimentos (mesón y tabla de picar) tienen presencia de bacterias: Salmonella con mayor frecuencia; E. coli, Klebsiella pneumoniae y Pseudomonas aeruginosa de mediana frecuencia y de baja para Shigella, y en el área de consumo de alimentos (mesas) la bacteria de mayor frecuencia es la E. coli y Shigella, la Klebsiella pneumoniae de mediana y Pseudomona aeruginosa se encuentra en baja frecuencia. Se llegó a la conclusión que las superficies inertes tanto en el área de preparación como en el área de consumo de alimentos se encuentran contaminados por lo que hay un riesgo de infección alimentaria para los comensales de la Universidad Técnica de Machala.

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Contamination of preparation areas when coming into contact with raw or cooked foods, which is why one of the main causes of contamination of inert surfaces is inadequate handling of food when it is being prepared. With the aim of controlling the application of hygiene standards in the areas of food preparation and consumption through microbiological analysis to reduce the risks of food contamination. This research is descriptive in nature, in which a visual inspection of the establishment was carried out with the purpose of evaluating the sanitary and hygienic conditions, through the application of the Technical Guide for the Microbiological Analysis of Surfaces in Contact with Food and Beverages. For the microbiological analysis of the samples, inoculation techniques, streaking method, bacterial isolation, differential staining and use of biochemical tests such as: TSI, SIM, Simmons Citrate, Urea, Lysine, Catalase and Oxidase, in addition to use of selective and differential culture media such as EMB agar and MacConkey agar for the identification of enteric bacteria such as: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. The results showed that the bacterial frequency of the inert surfaces of the restaurants in the food preparation area (counter and cutting board) have the presence of bacteria: Salmonella more frequently; E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa of medium frequency and low frequency for Shigella, and in the food consumption area (tables) the most frequent bacteria are E. coli and Shigella, Klebsiella pneumoniae of medium and Pseudomona aeruginosa It is at low frequency. It was concluded that the inert surfaces in both the preparation area and the food consumption area are contaminated, so there is a risk of food infection for diners at the Technical University of Machala

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Contaminação das áreas de preparo ao entrar em contato com alimentos crus ou cozidos, por isso uma das principais causas de contaminação de superfícies inertes é o manuseio inadequado dos alimentos no momento do preparo. Com o objetivo de controlar a aplicação de padrões de higiene nas áreas de preparação e consumo de alimentos através de análises microbiológicas para reduzir os riscos de contaminação alimentar. Esta pesquisa é de natureza descritiva, na qual foi realizada uma inspeção visual do estabelecimento com a finalidade de avaliar as condições sanitárias e higiênicas, por meio da aplicação do Guia Técnico para Análise Microbiológica de Superfícies em Contato com Alimentos e Bebidas. Para a análise microbiológica das amostras foram utilizadas técnicas de inoculação, método de estrias, isolamento bacteriano, coloração diferencial e utilização de testes bioquímicos como: TSI, SIM, Citrato de Simmons, Ureia, Lisina, Catalase e Oxidase, além de utilização de testes seletivos e diferenciais. meios de cultura como ágar EMB e ágar MacConkey para identificação de bactérias entéricas como: E. coli, Salmonella, Klebsiella pneumoniae, Shigella, Pseudomona aeruginosa. Os resultados mostraram que a frequência bacteriana das superfícies inertes dos restaurantes na área de preparo de alimentos (balcão e tábua de corte) apresentam com maior frequência a presença de bactérias: Salmonella; E. coli, Klebsiella pneumoniae e Pseudomonas aeruginosa de média frequência e baixa frequência para Shigella, e na área de consumo alimentar (tabelas) as bactérias mais frequentes são E. coli e Shigella, Klebsiella pneumoniae de média e Pseudomona aeruginosa Está em baixa frequência. Concluiu-se que as superfícies inertes tanto na área de preparação como na área de consumo de alimentos estão contaminadas, pelo que existe risco de infecção alimentar para os comensais da Universidade Técnica de Machala

Assuntos

Técnicas Microbiológicas

RESUMO

In this study, we investigate the spin-momentum locking phenomenon on Rashba states of antimony (Sb) films. Utilizing spin pumping in conjunction with an external charge current, we uncover the topological properties of Sb surface states. Our key finding is the precise manipulation of the direction and magnitude of the charge current generated by the inverse Rashba-Edelstein effect. This control is achieved through the dynamic interaction between out-of-equilibrium pumped spins and spin-momentum-locked flowing spins, which are perpendicular to the charge current. Our results highlight Sb as a promising material for both fundamental and applied spintronics research. The studied Sb nanostructures demonstrate potential for the development of low-power logic gates operating with currents in the microampere range, paving the way for advanced spintronic applications.

RESUMO

Introduction: Infections acquired during healthcare setting stay pose significant public health threats. These infections are known as Healthcare-Associated Infections (HAI), mostly caused by pathogenic bacteria, which exhibit a wide range of antimicrobial resistance. Currently, there is no knowledge about the global cleaning process of hospitals and the bacterial diversity found in ICUs of Brazilian hospitals contributing to HAI. Objective: Characterize the microbiome and common antimicrobial resistance genes present in high-touch Intensive Care Unit (ICU) surfaces, and to identify the potential contamination of the sanitizers/processes used to clean hospital surfaces. Methods: In this national, multicenter, observational, and prospective cohort, bacterial profiles and several antimicrobial resistance genes from 41 hospitals across 16 Brazilian states were evaluated. Using high-throughput 16S rRNA amplicon sequencing and real-time PCR, the bacterial abundance and resistance genes presence were analyzed in both ICU environments and cleaning products. Results: We identified a wide diversity of microbial populations with a recurring presence of HAI-related bacteria among most of the hospitals. The median bacterial positivity rate in surface samples was high (88.24%), varying from 21.62 to 100% in different hospitals. Hospitals with the highest bacterial load in samples were also the ones with highest HAI-related abundances. Streptococcus spp., Corynebacterium spp., Staphylococcus spp., Bacillus spp., Acinetobacter spp., and bacteria from the Flavobacteriaceae family were the microorganisms most found across all hospitals. Despite each hospital particularities in bacterial composition, clustering profiles were found for surfaces and locations in the ICU. Antimicrobial resistance genes mecA, bla KPC-like, bla NDM-like, and bla OXA-23-like were the most frequently detected in surface samples. A wide variety of sanitizers were collected, with 19 different active principles in-use, and 21% of the solutions collected showed viable bacterial growth with antimicrobial resistance genes detected. Conclusion: This study demonstrated a diverse and spread pattern of bacteria and antimicrobial resistance genes covering a large part of the national territory in ICU surface samples and in sanitizers solutions. This data should contribute to the adoption of surveillance programs to improve HAI control strategies and demonstrate that large-scale epidemiology studies must be performed to further understand the implications of bacterial contamination in hospital surfaces and sanitizer solutions.

Assuntos

Infecção Hospitalar , Farmacorresistência Bacteriana , Unidades de Terapia Intensiva , RNA Ribossômico 16S , Brasil , Humanos , RNA Ribossômico 16S/genética , Infecção Hospitalar/microbiologia , Estudos Prospectivos , Farmacorresistência Bacteriana/genética , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Bactérias/classificação , Hospitais , Reação em Cadeia da Polimerase em Tempo Real , Antibacterianos/farmacologia

RESUMO

The dental implant surface plays a crucial role in osseointegration. The topography and physicochemical properties will affect the cellular functions. In this research, four distinct titanium surfaces have been studied: machined acting (MACH), acid etched (AE), grit blasting (GBLAST), and a combination of grit blasting and subsequent acid etching (GBLAST + AE). Human amniotic mesenchymal (hAMSCs) and epithelial stem cells (hAECs) isolated from the amniotic membrane have attractive stem-cell properties. They were cultured on titanium surfaces to analyze their impact on biological behavior. The surface roughness, microhardness, wettability, and surface energy were analyzed using interferometric microscopy, Vickers indentation, and drop-sessile techniques. The GBLAST and GBLAST + AE surfaces showed higher roughness, reduced hydrophilicity, and lower surface energy with significant differences. Increased microhardness values for GBLAST and GBLAST + AE implants were attributed to surface compression. Cell viability was higher for hAMSCs, particularly on GBLAST and GBLAST + AE surfaces. Alkaline phosphatase activity enhanced in hAMSCs cultured on GBLAST and GBLAST + AE surfaces, while hAECs showed no mineralization signals. Osteogenic gene expression was upregulated in hAMSCs on GBLAST surfaces. Moreover, α2 and ß1 integrin expression enhanced in hAMSCs, suggesting a surface-integrin interaction. Consequently, hAMSCs would tend toward osteoblastic differentiation on grit-blasted surfaces conducive to osseointegration, a phenomenon not observed in hAECs.

Assuntos

Âmnio , Implantes Dentários , Propriedades de Superfície , Titânio , Humanos , Titânio/química , Âmnio/citologia , Âmnio/metabolismo , Osteogênese , Diferenciação Celular , Células Cultivadas , Osseointegração , Células-Tronco/citologia , Células-Tronco/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Sobrevivência Celular , Fosfatase Alcalina/metabolismo

RESUMO

HYPOTHESIS: The petal effect is a well-known natural phenomenon in surface science and has served as inspiration for the creation of several materials with superhydrophobic qualities and high adhesion. As surface roughness has a crucial role in these properties, being able to modulate it could help us design materials at will. Capillary penetration frustrates diffusion and promotes large contact angles as well as high adhesion. EXPERIMENTS: Polystyrene surfaces were created using the spin-coating technique. By varying the polymer concentration, the surface roughness was modified. To determine the roughness parameters, atomic force microscopy was used. We recorded advancing and receding contact angles using water and glycerol as test liquids to study contact angle hysteresis, the work of adhesion and the apparent surface energy, which was determined with the Chibowski and Perea-Carpio method. For the purpose of elucidating the wetting states, captive bubble experiments were conducted. FINDINGS: Using an easy method, we create polystyrene surfaces with both superhydrophobicity and strong adhesion, where the roughness area factor regulates wetting transitions from Cassie-Baxter to Wenzel. The receding contact angle suggests capillary penetration, which we demonstrate by captive bubble experiments. In addition, a link was found between the surface roughness and apparent surface energy.

RESUMO

This study evaluates the performance of large intelligent surface (LIS) technology in the context of a multi-user MIMO mobile communication system (Mu-MIMO) proposed for the sixth generation (6G). LIS employs digitally controlled reflectors to enhance Signal-to-Interference plus Noise Ratio (SINR) and establish line of sight (LoS) connectivity in non-LoS environments, improving transmission security. Analytical expressions are derived to assess LIS performance metrics, including distribution parameters, bit error probability, and secrecy outage probability, considering the presence of eavesdroppers and environmental fading. The study highlights the potential of LIS technology to enhance the confidentiality and reliability of digital communication systems in next-generation networks.

RESUMO

A review on planar printed structures that are based on Matryoshka-like geometries is presented. These structures use the well-known principle of Matryoshka dolls that are successively nested inside each other. The well-known advantages of the planar printed technology and of the meandered nested Matryoshka geometries are combined to generate miniaturized, multi-resonance, and/or wideband configurations. Both metal and complementary slot structures are considered. Closed and open configurations were analyzed. The working principles were explored in order to obtain physical insight into their behavior. Low-cost and single-layer applications as frequency-selective surfaces, filters, antennas, and sensors, in the microwave frequency region, were reviewed. Potential future research perspectives and new applications are then discussed.

RESUMO

While titanium dental implants have already been clinically established, ongoing research is continuously being conducted to advance the fields of osseointegration and bacterial resistance, seeking further improvements in these areas. In this study, we introduce an innovative method for treating titanium surfaces within tightly sealed packaging. Specifically, titanium discs, enclosed in surgical-grade packaging, underwent treatment using cold atmospheric plasma (CAP). The surfaces were thoroughly characterized in terms of wettability, crystalline structure, and chemical composition. Hemocompatibility analyses were conducted using blood diluted in sodium citrate (1:9) exposed to titanium discs for 30 min inside a CO2 incubator at 37 °C. Subsequently, various blood parameters were evaluated, including prothrombin time (PT), activated partial thromboplastin time (APTT), and platelet adhesion. Microbiological analyses were also performed using Pseudomonas aeruginosa (ATCC 27853) for 4 h at 37 °C. The treatment with CAP Jet resulted in a reduction in contact angle without causing any changes in the crystalline structure. No statistically significant differences were observed in the blood parameters. The plasma-treated samples exhibited lower PT and APTT values compared to those of the control group. The surfaces treated with CAP Jet showed increased platelet activation, platelet density, and thrombus formation when compared with the untreated samples. Moreover, the treated surfaces demonstrated lower bacterial colony formation compared with other surfaces.

Assuntos

Gases em Plasma , Titânio , Propriedades de Superfície , Titânio/farmacologia , Titânio/química , Gases em Plasma/farmacologia , Gases em Plasma/química , Molhabilidade , Plaquetas

RESUMO

This study assessed the efficacy of ozone (bubble diffusion in water; 6.25 ppm) and photodynamic inactivation (PDT) using curcumin (75 µM) as photosensitizer (LED emission 430-470 nm; 33.6 mW/cm2 irradiance; 16.1, 20.2, and 24.2 J/cm2 light dose) against the Norovirus surrogate bacteriophage MS2 in Brazilian berries (black mulberry and pitanga) and surfaces (glass and stainless steel). Contaminated berries and surfaces were immersed in ozonized water or exposed to PDT-curcumin for different time intervals. Transmission electron microscopy was used to assess the effects of the treatments on MS2 viral particles. The MS2 inactivation by ozone and PDT-curcumin varied with the fruit and the surface tested. Ozone reduced the MS2 titer up to 3.6 log PFU/g in black mulberry and 4.1 log PFU/g in pitanga. On surfaces, the MS2 reduction by ozone reached 3.6 and 4.8 log PFU/cm2 on glass and stainless steel, respectively. PDT-curcumin reduced the MS2 3.2 and 4.8 log PFU/g in black mulberry and pitanga and 2.7 and 3.3 log PFU/cm2 on glass and stainless steel, respectively. MS2 particles were disintegrated by exposure of MS2 to ozone and PDT-curcumin on pitanga. Results can contribute to establishing effective practices for controlling NoV in fruits and surfaces, estimated based on MS2 bacteriophage behavior.

Assuntos

Curcumina , Norovirus , Ozônio , Frutas , Levivirus , Aço Inoxidável , Ozônio/farmacologia , Brasil , Curcumina/farmacologia , Água/farmacologia , Inativação de Vírus

RESUMO

Abstract This study evaluated the influence of a fluoride-modified titanium surface on osseointegration in rats with induced diabetes. One hundred and eighty rats were randomly allocated into 3 groups with 60 animals each: Control group (C): Animals without diabetes; Diabetes Group (D): Animals with uncontrolled induced diabetes; Controlled Diabetes Group (CD): Animals with diabetes induced controlled by the insulin administration. Diabetes was induced by streptozotocin injection. Each animal received 2 implants in the proximal tibial metaphysis, one with the machined surface (M) and the other one with a fluoride-modified titanium surface (F), after 4 weeks of induction of diabetes. The animals were submitted to euthanasia 2, 4, and 6 weeks after the implant placement (n = 20 animals/group). The osseointegration was evaluated by the implant removal torque test and the histometric analysis of the non-decalcified histological sections: 1) Contact bone/implant (%BIC); 2) Bone tissue area between implant threads (%BBT). Implants with F surface showed a higher removal torque than implants with surface M in all groups. There was no difference in %BIC between the groups regardless of the surface used. The F surface showed a tendency to present higher %BBT values for the 3 evaluation periods in the D group. The fluoride-modified implant surface has no impact on the %BIC and %BBT. However, the fluoride-modified implant surface increases the locking of the implants with the bone. The hyperglycemia was associated with lower removal torque values despite the surfaces of the implant used.

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Resumo Este estudo avaliou a influência de uma superfície de titânio modificada com flúor na osseointegração em ratos com diabetes induzida. Cento e oitenta ratos foram distribuídos aleatoriamente em 3 grupos com 60 animais cada: Grupo controle (C): Animais sem diabetes; Grupo Diabetes (D): Animais com diabetes induzida descompensada; Grupo Diabetes Controlado (CD): Animais com diabetes induzido controlado pela administração de insulina. O diabetes foi induzido por injeção de estreptozotocina. Cada animal recebeu 2 implantes na metáfise proximal da tíbia, um com superfície usinada (M) e outro com superfície de titânio modificado com flúor (F), após 4 semanas de indução do diabetes. Os animais foram submetidos à eutanásia 2, 4 e 6 semanas após a colocação do implante (n = 20 animais/grupo). A osseointegração foi avaliada pelo teste de torque de remoção do implante e pela análise histométrica dos cortes histológicos não descalcificados: 1) Contato osso-implante (%BIC); 2) Área de tecido ósseo entre as roscas do implante (%BBT). Os implantes com superfície F apresentaram maior torque de remoção do que os implantes com superfície M em todos os grupos. Não houve diferença no %BIC entre os grupos independente da superfície utilizada. A superfície F mostrou tendência a apresentar maiores valores de %BBT para os 3 períodos de avaliação no grupo D. As superfícies de implantes modificadas com flúor não influenciaram nos dados de %BIC e %BBT. Entretanto, essas superfícies aumentaram o travamento dos implantes no tecido ósseo. A hiperglicemia foi associada a menores torques de remoção dos implantes independentemente do tipo de superfície de implante utilizada.

RESUMO

The amylolytic action of α-amylase and amyloglucosidase has been directly implemented in native cassava starches for the formation of cassava microporous granules with unsatisfactory results, however, its incidence in hydrothermally treated granules has never been evaluated. The effect of hydrothermal processes and simultaneous enzymatic hydrolysis on the physicochemical, morphological and structural properties of native cassava starch was evaluated. Native cassava starch presented a rigid, smooth surface, and was exempt from porosities, whereas hydrothermal processes altered the semicrystalline order and increasing the size and number of pores and increasing the size (4.11 ± 0.09 nm) and volume of pores (0.82 ± 0.00 cm3/g × 10-3). The hydrothermal action followed by enzymatic processes with α-amylase and amyloglucosidase, augmented the processes of internal degradation (endo-erosion) and pore widening (exo-erosion), improving the hydrophilic properties compared to the hydrothermal treatment. Likewise, the hydrothermally process followed by enzymatic hydrolysis for 24 h (HPS + EMS-24) increased the degradation of the amorphous lamellae, consistent with a significant decrease in amylose content. This same dual treatment increased the pore size at 17.68 ± 0.13 nm relative to the native counterpart; therefore, they are considered an effective method in the development of modified cassava starches with porous surfaces.

RESUMO

OBJECTIVES: The present study aimed to evaluate the potential of the salivary pellicle (SP) formed on titanium (Ti) surfaces to modulate the formation of a biofilm composed of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. MATERIALS AND METHODS: Ti substrates were incubated for 2 h with a pool of saliva samples obtained from 10 systemically and periodontally healthy subjects. Enamel substrates were included as a biological reference. Scanning electron microscopy (SEM) and Raman spectroscopy analysis were used to analyze the formation of the salivary pellicle. After the SP formation, the surfaces were incubated for 12 h with a mix of Streptococcus gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis. The number of bacterial cells attached to each surface was determined by the XTT assay while bacterial viability was analyzed by fluorescence microscopy using the LIVE/DEAD® BacLightTM kit. RESULTS: The SEM and Raman spectroscopy analysis confirmed the presence of a salivary pellicle formed on the tested surfaces. Regarding the biofilm formation, the presence of the SP decreases the number of the bacterial cells detected in the test surfaces, compared with the uncover substrates. Even more, the SP-covered substrates showed similar bacterial counts in both Ti and enamel surfaces, meaning that the physicochemical differences of the substrates were less determinant than the presence of the SP. While on the SP-uncover substrates, differences in the bacterial adhesion patterns were directly related to the physicochemical nature of the substrates. CONCLUSIONS: The salivary pellicle was the main modulator in the development of the biofilm consisting of representative oral bacteria on the Ti substrates. CLINICAL RELEVANCE: The results of this study provide valuable information on the modulatory effect of the salivary pellicle on biofilm formation; such information allows us to understand better the events involved in the formation of oral biofilms on Ti dental implants.

Assuntos

Biofilmes , Titânio , Humanos , Película Dentária/química , Película Dentária/microbiologia , Titânio/química , Aderência Bacteriana , Streptococcus gordonii , Fusobacterium nucleatum , Propriedades de Superfície

RESUMO

Multifunctional surfaces may display the potential to accelerate and promote the healing process around dental implants. However, the initial cellular biocompatibility, molecular activity, and the release of functionalized molecules from these novel surfaces require extensive investigation for clinical use. Aiming to develop and compare innovative surfaces for application in dental implants, the present study utilized titanium disks, which were treated and divided into four groups: machined (Macro); acid-etched (Micro); anodized-hydrophilic surface (TNTs); and anodized surface coated with a rifampicin-loaded polymeric layer (poly(lactide-co-glycolide), PLGA) (TNTsRIMP). The samples were characterized regarding their physicochemical properties and the cumulative release of rifampicin (RIMP), investigated at different pH values. Additionally, differentiated osteoblasts from mesenchymal cells were used for cell viability and qRT-PCR analysis. Antibacterial properties of each surface treatment were investigated against Staphylococcus epidermidis. TNTsRIMP demonstrated controlled drug release for up to 7 days in neutral pH environments. Osteogenic cell cultures indicated that all the evaluated surfaces showed biocompatibility. The TNTs group revealed up-regulated values for bone-related gene quantification in 7 days, followed by the TNTsRIMP group. Furthermore, the antibiotic-functionalized surface revealed effectiveness to inhibit S. epidermidis and stimulate promising conditions for osteogenic cell behavior. Characteristics such as nanomorphology and hydrophilicity were determinants for the up-regulated quantification of osteogenic biomarkers related to early bone maturation, encouraging application in intra-osseous implant surfaces; in addition, antibiotic-functionalized surfaces demonstrated significant higher antibacterial properties compared to the other groups. Our findings suggest that polymeric-antibiotic-loaded coating might be applied for the prevention of early infections, favoring its application in multifunctional surfaces for intra- and/or trans-mucosal components of dental implants, while, hydrophilic nanotextured surfaces promoted optimistic properties to stimulate early bone-related cell responses, favoring its application in bone-anchored surfaces.

Assuntos

Antibacterianos , Implantes Dentários , Antibacterianos/farmacologia , Rifampina/farmacologia , Propriedades de Superfície , Diferenciação Celular , Titânio/farmacologia , Titânio/química , Osseointegração

RESUMO

Objetivo ­ Verificar a suscetibilidade de criação de fômites de Sars-Cov-2 de acordo com temperatura, umidade e período de exposição. Métodos ­ Foi realizada uma revisão sistemática da literatura, entre março de 2021 e junho de 2022, utilizando-se a Biblioteca Virtual em Saúde (BVS), PubMed e Medline, através do cruzamento dos termos SARS-COV-2 AND desinfecção AND higienização AND fômites AND superfícies. Resultados ­ Dos 295 artigos encontrados, 24 foram selecionados e divididos em 3 categorias temáticas, "A influência das condições ambientais", "detecção por período de exposição" e "amostragens não experimental". Conclusões ­ Foi observado que existe a possibilidade da formação de fômites de Sars-Cov-2 e as condições ambientais influenciam diretamente, exigindo assim cuidado com superfícies possivelmente contaminadas. Descritores: Sars-Cov2; Desinfecção; Fômites; Superfícies

Assuntos

Humanos , Fômites , SARS-CoV-2 , Virulência , Desinfecção , Umidade

RESUMO

AIM: The success of dental implants depends on osseointegration can be compromised by well-known related adverse biological processes, such as infection and diabetes. Previously, nanohydroxyapatite-coated titanium surfaces (nHA_DAE) have been shown to contain properties that promote osteogenesis by enhancing osteoblast differentiation. In addition, it was hypothesized to drive angiogenesis in high-glucose microenvironments, mimicking diabetes mellitus (DM). On the other hand, the null hypothesis would be confirmed if no effect was observed in endothelial cells (ECs). MATERIALS AND METHODS: Titanium discs presenting the differential surfaces were previously incubated in an FBS-free cell culture medium for up to 24 h, which was, thereafter, supplemented with 30.5 mM of glucose to expose human umbilical vein endothelial cells (HUVECs, ECs) for 72 h. They were then harvested, and the sample was processed to provide molecular activity of specific genes related to EC survival and activity by using qPCR, and the conditioned medium by ECs was used to evaluate the activity of matrix metalloproteinases (MMPs). RESULTS: Our data guaranteed better performance of this nanotechnology-involved titanium surface to this end once the adhesion and survival characteristics were ameliorated by promoting a higher involvement of ß1-Integrin (~1.5-fold changes), Focal Adhesion Kinases (FAK; ~1.5-fold changes) and SRC (~2-fold changes) genes. This signaling pathway culminated with the cofilin involvement (~1.5-fold changes), which guaranteed cytoskeleton rearrangement. Furthermore, nHA_DAE triggered signaling that was able to drive the proliferation of endothelial cells once the cyclin-dependent kinase gene was higher in response to it, while the P15 gene was significantly down-regulated with an impact on the statement of angiogenesis. CONCLUSIONS: Altogether, our data show that a nanohydroxyapatite-coated titanium surface ameliorates the EC performance in a high-glucose model in vitro, suggesting its potential application in DM patients.

RESUMO

Co-abietate and Cu-abietate complexes were obtained by a low-cost and eco-friendly route. The synthesis process used Pinus elliottii resin and an aqueous solution of CuSO4/CoSO4 at a mild temperature (80 °C) without organic solvents. The obtained complexes are functional pigments for commercial architectural paints with antipathogenic activity. The pigments were characterized by Fourier-transform infrared spectroscopy (FTIR), mass spectrometry (MS), thermogravimetry (TG), near-edge X-ray absorption fine structure (NEXAFS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and colorimetric analysis. In addition, the antibacterial efficiency was evaluated using the minimum inhibitory concentration (MIC) test, and the antiviral tests followed an adaptation of the ISO 21702:2019 guideline. Finally, virus inactivation was measured using the RT-PCR protocol using 10% (w/w) of abietate complex in commercial white paint. The Co-abietate and Cu-abietate showed inactivation of >4 log against SARS-CoV-2 and a MIC value of 4.50 µg·mL-1 against both bacteria Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The results suggest that the obtained Co-abietate and Cu-abietate complexes could be applied as pigments in architectural paints for healthcare centers, homes, and public places.