Electrochemical and in vitro biological behaviors of a Ti-Mo-Fe alloy specifically designed for stent applications.

There is a deep interest in developing new Ni-free Ti-based alloys to replace 316 L stainless steel and Co-Cr alloys for endovascular stent application, mainly because the release of Ni can generate toxicity and allergenicity. Interactions of Ti alloy biomaterials with bone cells and tissues have been widely investigated and reported, while interactions with vascular cells and tissues, such as endothelial cells (ECs) and smooth muscle cells (SMCs), are scarce. Therefore, this study focused on the relationship among the surface finishing features, corrosion behavior and in vitro biological performances regarding human ECs, SMCs and blood of a newly developed Ti-8Mo-2Fe (TMF) alloy, specifically designed for balloon-expandable stent applications. The alloy performances were compared to those of 316 L and pure Ti, prepared with the same surface finishing techniques, which are mechanical polishing and electropolishing. Surface properties were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle (CA) and x-ray photoelectron spectroscopy (XPS). The corrosion behavior was assessed with potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) tests in phosphate buffered saline (PBS) solution. No significant differences were observed regarding the corrosion rate measured with PDP analyses, which was of the order of 2 × 10-4 mm/y for all the studied materials. Moreover, similarly to pure Ti, TMF exhibited an advantage over 316 L for biomedical applications, namely remarkable resistance to pitting corrosion up to high potentials. The results evidenced a good cytocompatibility and hemocompatibility, making this group of alloy a potential candidate for cardiovascular implants. In fact, both ECs and SMCs proliferated on TMF surfaces showing a 7-day viability similar to that of pure Ti. Regarding hemocompatibility, TMF did not cause hemolysis, and blood coagulation was delayed on its surface in comparison to pure Ti. When compared to 316 L, TMF showed similar hemocompatibility.

Characterization of a Magnesium Fluoride Conversion Coating on Mg-2Y-1Mn-1Zn Screws for Biomedical Applications.

MgF2-coated screws made of a Mg-2Y-1Mn-1Zn alloy, called NOVAMag® fixation screws (biotrics bioimplants AG), were tested in vitro for potential applications as biodegradable implants, and showed a controlled corrosion rate compared to non-coated screws. While previous studies regarding coated Mg-alloys have been carried out on flat sample surfaces, the present work focused on functional materials and final biomedical products. The substrates under study had a complex 3D geometry and a nearly cylindrical-shaped shaft. The corrosion rate of the samples was investigated using an electrochemical setup, especially adjusted to evaluate these types of samples, and thus, helped to improve an already patented coating process. A MgF2/MgO coating in the µm-range was characterized for the first time using complementary techniques. The coated screws revealed a smoother surface than the non-coated ones. Although the cross-section analysis revealed some fissures in the coating structure, the electrochemical studies using Hanks' salt solution demonstrated the effective role of MgF2 in retarding the alloy degradation during the initial stages of corrosion up to 24 h. The values of polarization resistance (Rp) of the coated samples extrapolated from the Nyquist plots were significantly higher than those of the non-coated samples, and impedance increased significantly over time. After 1200 s exposure, the Rp values were 1323 ± 144 Ω.cm2 for the coated samples and 1036 ± 198 Ω.cm2 for the non-coated samples, thus confirming a significant decrease in the degradation rate due to the MgF2 layer. The corrosion rates varied from 0.49 mm/y, at the beginning of the experiment, to 0.26 mm/y after 1200 s, and decreased further to 0.01 mm/y after 24 h. These results demonstrated the effectiveness of the applied MgF2 film in slowing down the corrosion of the bulk material, allowing the magnesium-alloy screws to be competitive as dental and orthopedic solutions for the biodegradable implants market.

Corrigendum: Impact of the COVID-19 pandemic on the diagnosis of tuberculosis in Brazil: Is the WHO end TB strategy at risk?

[This corrects the article DOI: 10.3389/fphar.2022.891711.].

Impact of the COVID-19 Pandemic on the Diagnosis of Tuberculosis in Brazil: Is the WHO End TB Strategy at Risk?

Background: In 2014, the World Health Organization (WHO) launched the "post-2015 End TB strategy", that aims to end the global tuberculosis (TB) epidemic by 2030. However, the COVID-19 pandemic has severely impacted global public health and the strict measures to control the coronavirus spread can affect the management of other diseases, such as TB. Herein, we aimed to assess the impact of the COVID-19 pandemic on the diagnosis of TB in Brazil, during 2020. Methods: We carried out an ecological and population-based study, using spatial analysis techniques. The variables used were the new cases of TB, pulmonary tuberculosis (PTB), and also baciloscopy-positive (BP) cases in Brazil between 2015 and 2020. The percentage of changes (% change) was calculated to verify if there was an increase or decrease of TB cases in 2020, along with time trend analyses given by Joinpoint regression model. Also, interrupted time series analyses were used to assess the trend of TB diagnosis before and after the onset of the COVID-19 in Brazil. Spatial distribution maps were elaborated, considering the % change of each Brazilian state. Findings: Data analyses showed a reduction in the diagnosis of TB (-8.3%) and PTB (-8.1%) in Brazil after the irruption of the COVID-19 pandemic. Likewise, 22 states depicted a reduction in TB diagnosis. An expressive reduction of BP cases (-17.1%) was also observed. Interestingly, interrupted time series analysis showed decline in TB and PTB diagnoses from March 2020. Spatial analyses revealed that all states had a progressive reduction of TB, PTB and PB cases, from March on, with the highest percentages of reduction in December (-100% to -75%). Interpretation: Taken together, our analyses demonstrated a reduction in TB diagnosis after the irruption of the COVID-19 pandemic in Brazil and its regions, signaling a serious impact on the WHO "End TB Strategy" global plan.

[Woman's experience with the choice of the Billings Ovulation Method]. / Vivência da mulher na escolha do Método de Ovulação Billings.

This is a case study with a qualitative approach, carried out between February and November 2010 with 10 women, mean age of 34 years old, users of this Billings Ovulation Method (MOB) for over than two years, with the objective of understand the experience of women by choosing the MOB. Data was obtained from interviews, and analyzed through content analysis technique. The categories of analysis showed that the reasons for the choices of the MOB were: religion; natural method, and benefits of self-knowledge. It was concluded that women show confidence in carrying out the method, that it brings benefits for users and that there is a need for professional guidance for its correct practice.

Vivência da mulher na escolha do Método de Ovulação Billings / Woman’s experience with the choice of the Billings Ovulation Method / Experiencia de la mujer en la elección del Método de Ovulación Billings

Trata-se de um estudo de caso com abordagem qualitativa, realizado entre fevereiro e novembro de 2010, com 10 mulheres, com idade média de 34 anos, usuárias do Método da Ovulação Billings (MOB), há mais de dois anos, cujo objetivo foi compreender a vivência da mulher na escolha do MOB. Os dados foram obtidos a partir de entrevistas, e analisados segundo a técnica de análise de conteúdo. As categorias de análise apontaram as principais infl uências na escolha do MOB: religião; naturalidade do método e benefícios do autoconhecimento. Concluiu-se que as mulheres revelam confiança na realização do método, que ele traz benefícios para as usuárias e que há necessidade de orientação profissional para a sua prática correta.

This is a case study with a qualitative approach, carried out between February and November 2010 with 10 women, mean age of 34 years old, users of this Billings Ovulation Method (MOB) for over than two years, with the objective of understand the experience of women by choosing the MOB. Data was obtained from interviews, and analyzed through content analysis technique. The categories of analysis showed that the reasons for the choices of the MOB were: religion; natural method, and benefits of self-knowledge. It was concluded that women show confidence in carrying out the method, that it brings benefits for users and that there is a need for professional guidance for its correct practice.

Se trata de un estudio de caso con abordaje cualitativa, realizado entre febrero y noviembre de 2010, con 10 mujeres, con edad media de 34 años, usuarias del Método de la Ovulación Billings (MOB) a más de dos años, cuyo objetivo fue comprender la vivencia de la mujer en elegir el MOB. Los dados se obtuvieron a partir de entrevistas, y fueran analizados según la técnica de análisis de contenido. Las categorías de análisis mostraron que las mayores infl uencias para la elección del MOB fueron: religión; naturalidad del método y beneficios del auto-conocimiento. Sin embargo, se concluye que las mujeres muestran confianza en la realización del método, que esto trae beneficios para ellas y que hay necesidad de orientación profesional para la práctica correcta del método.