■ abstract Introduction: Microsurgical techniques are characterized by the application of maneuvers and sutures to millimetric structures with the aid of magnifying lenses. These are complex techniques, used in various medical specialties, which require great skill and training before applying them to humans. The objective is to develop a low-cost and high-fidelity model for training microsurgery techniques using a fragment of bovine pericardium patch. Method: Remaining segments of a bovine pericardium plate, previously used in vascular repairs, are used to create this model. The material is cut into two symmetrical parts, and its ends are fixed to the surgical drapes with the aid of clamps. The upper edge of each part is then sutured to the lower edge with 8-0 Prolene thread so that each one forms a tubular structure. Subsequently, the free tubular ends undergo dissection of the adventitial layer and are sutured together, mimicking an end-to-end vascular anastomosis. Results: With the model, the same inconveniences/difficulties present in human vascular sutures are simulated, such as delamination of layers, excess of the adventitial layer, and risk of inadvertent suturing of the posterior wall, proving its usefulness in the acquisition of basic microsurgical skills, without need to manipulate human or animal tissues. Practice in this model can take place within the surgical center itself and uses materials that would otherwise be discarded. Conclusion: The use of bovine pericardium to create millimetric sutures mimics human vascular tissue and is a low-cost procedure that allows the training of microsurgical skills.

■ RESUMO Introdução: As técnicas microcirúrgicas caracterizam-se pela aplicação de manobras e suturas em estruturas milimétricas com o auxílio de lentes de aumento. São técnicas complexas, utilizadas em diversas especialidades médicas, que demandam grande habilidade e treinamento antes da aplicação em humanos. O objetivo é desenvolver um modelo de baixo custo e alta fidelidade, para o treinamento de técnicas de microcirurgia, utilizando um fragmento de patch de pericárdio bovino. Método: São utilizados para a confecção deste modelo segmentos remanescentes de uma placa de pericárdio bovino, previamente utilizado em reparos vasculares. O material é recortado em duas partes simétricas e suas extremidades fixadas aos campos cirúrgicos, com auxílio de clamps. A borda superior de cada uma das partes é, então, suturada à borda inferior com fio de Prolene 8-0, de maneira que cada uma forme uma estrutura tubular. Posteriormente, as extremidades tubulares livres passam pela dissecção da camada adventícia e são suturadas entre si, mimetizando uma anastomose vascular término-terminal. Resultados: Com o modelo, simulam-se os mesmos inconvenientes/dificuldades presentes nas suturas vasculares humanas, como a delaminação de camadas, excesso da camada adventícia e risco de sutura inadvertida da parede posterior, provando sua utilidade na aquisição de habilidades microcirúrgicas básicas, sem necessidade de manipulação de tecidos humanos ou animais. A prática neste modelo pode ocorrer dentro do próprio centro cirúrgico e emprega materiais que seriam descartados. Conclusão: A utilização do pericárdio bovino para confecção de suturas milimétricas mimetiza o tecido vascular humano e é um procedimento de baixo custo, que possibilita o treinamento de habilidades microcirúrgicas.

Abstract Introduction: Currently, people living with HIV/ AIDS (PLWHA) attain a life expectancy similar to a non-HIV population. However, these patients experience a status of chronic inflammation, which is a known cause of arteriopathy. Yet, literature is scarce regarding the potential venous inflammatory effect, especially after varicose vein surgery. The aim of this study was to perform a descriptive analysis alongside evaluating short and long-term outcomes after varicose vein surgery in PLWHA while comparing with a control group. Methods: A retrospective nested case-control study was performed resorting to codification. All PLWHA patients which had any hospital interaction with the Vascular Surgery Department (either outpatient clinic, emergency or surgery) due to venous disease between April 2006 and December 2019 were identified. PLWHA found to have undergone varicose vein surgery within the study inclusion period were included. The immediately consecutive varicose vein surgery in a patient with no-HIV infection was included in the control group in a 1:1 ratio. Comorbidities were collected at the time of index event. Results: The cohort included 118 patients (59 PLWHA and 59 control) and had a mean follow-up of 86 [Interquartile range (IQR) 25-75%, 43-111] months. At baseline, PLWHA were younger (45.2 ± 10.71 vs 49.9 ± 10.69 years, p=0.017) and had a male predominance (54% vs 27%, p=0.003). Furthermore, there were a higher prevalence of smokers (54% vs 17%, p<0.001) and history of drug abuse (34% vs 2%, p<0.001) in the study group. Although not statistically significant, PLWHA presented higher pre-operative CEAP classifications. Regarding post-operative outcomes, no differences were found for complications, reinterventions or overall-mortality. Conclusion: To the authors knowledge, this is the first study addressing varicose vein treatment in PLWHA. In summary, PLWHA undergoing varicose vein surgery seem to be younger and have higher CEAP classifications. Nonetheless, short and long-term outcomes seem to be good and similar to a control population. Further studies with larger populations and disease specific outcomes are necessary to confirm such findings.

ABSTRACT Adjuvant-induced autoimmune syndrome (ASIA) and its diagnostic criteria were described by Shoenfeld in 2011, relating symptoms of autoimmunity to adjuvants, such as silicone, present in breast implants. This systematic review aimed to gather data from the literature on symptomatology, incidence and proposed treatments for ASIA caused by silicone breast implants (SBI). Searches were carried out in PubMed, LILACS, Embase and Cochrane databases, using the descriptors “Autoimmune Syndrome Induced by Adjuvants,” “Breast implant,” and “Silicone Implant Incompatibility Syndrome.” The search strategy generated 95 articles, of which 20 were included in the review. The authors suggest three main theories to explain the development of the syndrome: genetic predisposition, silicone bleeding and the formation of a periprosthetic capsule. The most frequently described clinical manifestations include chronic fatigue, arthralgia, myalgia, and cognitive and sleep disorders. There is no consensus on laboratory findings and associated risk factors; recent studies propose expanding the diagnostic criteria initially described. Adequate treatment remains controversial, ranging from medications to prosthesis explantation. Although the reviewed articles suggest the existence of ASIA related to SBI, its precise pathophysiology is unknown, the symptoms reported are nonspecific, and the time between exposure and the onset of manifestations is uncertain. This systematic review concludes that, to date, there is not enough scientific evidence to establish the causality of the development of adjuvant-induced autoimmune syndrome resulting from silicone breast implants.

RESUMO A síndrome autoimune induzida por adjuvantes (ASIA) e seus critérios diagnósticos foram descritos por Shoenfeld em 2011, relacionando sintomas de autoimunidade a adjuvantes, como o silicone, presente em próteses mamárias. Essa revisão sistemática objetivou reunir dados da literatura sobre a sintomatologia, a incidência e os tratamentos propostos para ASIA causada por implantes mamários de silicone (IMS). Foram realizadas pesquisas nas bases de dados PubMed, LILACS, Embase e Cochrane, utilizando os descritores “Autoimmune Syndrome Induced by Adjuvants”, “Breast implant” e “Silicone Implant Incompatibility Syndrome”. A estratégia de busca gerou 95 artigos, dos quais 20 foram incluídos na revisão. São as três as principais teorias sugeridas pelos autores para explicar o desenvolvimento da síndrome: predisposição genética, silicone bleeding e a formação de uma cápsula periprótese. As manifestações clínicas mais frequentemente descritas incluem fadiga crônica, artralgia, mialgia, distúrbios cognitivos e do sono. Não há consenso sobre os achados laboratoriais e os fatores de risco associados, além disso, estudos recentes propõem a ampliação dos critérios diagnósticos inicialmente descritos. O tratamento adequado permanece controverso, envolvendo desde o uso de medicações até o explante da prótese. Apesar dos artigos revisados sugerirem a existência da ASIA relacionada aos IMS, sua fisiopatologia precisa é desconhecida, os sintomas relatados são inespecíficos e o tempo entre a exposição e o surgimento das manifestações é incerto. Por meio dessa revisão sistemática, conclui-se que, até o presente momento, não existem evidências científicas suficientes para estabelecer a causalidade do desenvolvimento da síndrome autoimune induzida por adjuvantes decorrente de implantes mamários de silicone.

RESUMO Defeitos de orelha são frequentes e de etiologias diversas. Ainda assim, a reconstrução de orelha permanece um desafio dentro da cirurgia plástica reconstrutiva, principalmente devido a anatomia e a escassez de tecido local. Embora pouco utilizado, o retalho tubular retroauricular se apresenta como alternativa para reconstrução da hélice e lóbulo. No presente estudo os autores descrevem a técnica operatória, bem como relatam um caso em que foi utilizado. Realizou-se uma avaliação do resultado operatório de quatro casos de reconstrução de orelha utilizando o retalho tubular retroauricular, através de questionários encaminhados para avaliadores leigos e cirurgiões plásticos. O resultado estético final foi classificado como bom ou excelente por 35% dos avaliadores leigos e 50% dos cirurgiões plásticos. Já o resultado operatório foi avaliado como bom ou excelente por 70% dos leigos e 80% dos cirurgiões plásticos. Os resultados permitem concluir que a técnica do retalho tubular retroauricular para reconstrução de defeitos da borda de hélice pode ser indicada, com resultados satisfatórios.

ABSTRACT Ear defects are frequent and result of many etiologies, even though ear reconstruction remains a challenge in plastic reconstructive surgery due to anatomy and local tissue paucity. Despite being rarely used, the tubular retroauricular flap presents as an alternative for helix and lobule reconstruction. In this article, the authors describe the operative technique and report a case in which it was used. Also, plastic surgeons and laypeople rated the operative results of four cases of ear reconstructions using the tubular retroauricular flap. The final esthetic result was rated as good or excellent by 35% of laypeople and 50% of plastic surgeons, whereas the operative result was rated as good or excellent by 70% of laypeople and 80% of plastic surgeons. Thereby the findings and authors’ experience, we can recommend the tubular retroauricular flap technique for reconstructing ear helix border defects.

Abstract Introduction Convalescent Plasma therapy is one of the therapeutic strategies that has been used for patients with the Covid-19 disease. Implementing a program with national extension to supply hospitals with this blood component is a great challenge mainly in a middle-income economy. Objectives Our objective was to develop and implement a Covid-19 Convalescent Plasma Program which met established quality standards and was adapted to a reality of limited resources. Methods A multicentric convalescent plasma collection program was developed and implemented, based on four main sequential procedures: selective donor recruitment, pre-donation antibody screening (Anti-SARS-CoV-2- Chemiluminescence IgG Abbott), convalescent plasma collection by apheresis or whole-blood processing and distribution to the hospitals according to local demand. Results From the 572 candidates submitted to the pre-donation antibody screening, only 270 (47%) were considered eligible for plasma donation according to the established criteria. Higher levels of total antibody were associated with the donor age being above 45 years old (p= 0.002), hospital admission (p= 0.018), and a shorter interval between the diagnosis of the SARS-CoV-2 infection and plasma donation (p < 0.001). There was no association between the ABO and Rh blood groups and their antibody levels. Of the 468 donations made, 61% were from the collection of whole-blood and 39%, from apheresis. The Covid-19 Convalescent Plasma units obtained were distributed to 21 different cities throughout the country by air or ground transportation. Conclusion The implementation of a Covid-19 Convalescent Plasma program in a continental country with relatively scarce resources is feasible with alternative strategies to promote lower cost procedures, while complying with local regulations and meeting quality standards.

Abstract Introduction: People infected with the human immunodeficiency virus (HIV) - People living with HIV/AIDS (PLWHA) - seem to have an increased risk of incidence and prevalence of cardiovascular diseases, namely stroke of ischemic nature. Additional etiological mechanisms, in addition to aging, appear to lie in chronic virus-mediated inflammation as well as in antiretroviral therapy (ART). The aim of this study was to carry out a retrospective review with descriptive analysis of cases of PLWHA and with a diagnosis of carotid atherosclerotic disease in a tertiary referral center as well as a non-systematic review of the literature. Methods: All patients diagnosed with HIV infection and concomitantly diagnosed with carotid atherosclerotic disease, in a tertiary center, between October 2007 and December 2019, were selected. A descriptive analysis of the sample and additionally a non-systematic review of the literature using the MEDLINE database, were performed. Results: Nine patients who met the inclusion criteria were selected, 7 (78%) being male. The mean age at diagnosis of carotid disease was 59 years. The diagnosis of HIV infection preceded, on average, 12 years before the diagnosis of carotid disease, while the start of ART preceded this diagnosis by about 11 years. The most common cardiovascular risk factors are dyslipidemia (89%), high blood pressure (56%) and smoking (56%). Approximately 33% had peripheral arterial disease and 22% had coronary artery disease. Only two (22%) patients underwent carotid endarterectomy over a median follow-up of 5 years, both for asymptomatic stenosis. Since the diagnosis of carotid disease, there have been no major cardiovascular events (stroke or acute myocardial infarction). During follow-up there were two deaths. Conclusion: PLWHA have a high prevalence of multisite artery disease, manifesting it at a relatively earlier age compared to the general population. These patients benefit from multidisciplinary follow-up for therapeutic optimization in order to obtain better results. However, larger prospective studies are needed to clarify the results in these patients and to improve the therapeutic approach, particularly in those with concomitant carotid disease.

Abstract The development of new environmentally-friendly cutting fluids is an important technological advancement. The aim of this study was to assess the tribological behavior of microemulsions (W/O) developed with epoxidized soybean oil and nonionic surfactants with different degrees of ethoxylation (NP4EO, NP6EO and NP9.5EO). The tribological performance of the microemulsion systems was assessed in a High Frequency Reciprocating Rig (HFRR) tribometer. Microemulsions showed Newtonian fluid behavior, with viscosities compatible with conventional cutting fluids. In addition, contact angle values above 90º indicate spherical-shaped drops on the surface on which they are deposited, due to their hydrophobic nature. The microemulsions formulated using surfactants with lower ethoxylation numbers and 20% concentration exhibited greater stability, lower viscosity and better friction reduction during tribological contact between surfaces, given that the average wear scar diameter was 118 µm with smooth surfaces exhibiting slight slippage wear caused by abrasion, as identified by SEM/EDS analyses.

Resumo Este estudo teve como objetivo avaliar a eficácia das células-tronco mesenquimais (CTMs), isoladas ou associadas à dapsona (DAP), no tratamento de feridas dermonecróticas causadas pelo veneno de Loxosceles laeta. Vinte e cinco coelhos machos foram distribuídos em cinco grupos. O controle negativo recebeu água ultrapura (C-), enquanto todos os outros grupos foram injetados com 20 μg de veneno de L. laeta. Após 4 horas, cada grupo recebeu um dos seguintes tratamentos: PBS (C+), DAP, CTMs e DAP + CTMs. Os animais foram avaliados diariamente durante 12 dias, e feitos registros fotográficos para análise da ferida e no 12º dia, foram eutanasiados e, retiradas amostras de pele para análise histológica. Observou-se que a DAP apresentou o melhor percentual de contração da ferida no terceiro dia. Nos tratamentos com CTMs, observou-se uma contração negativa da ferida tanto para as CTMs isoladas, bem como a associação CTMs + DAP em relação ao PBS, possivelmente, pelo aumento da infamação inicial após a aplicação de células-tronco. Isso é devido ao fato de que as CTMs secretam um amplo espectro de moléculas bioativas como citocinas e fatores de crescimento que favorecem a regeneração. Histologicamente, observou-se que os animais de C+ apresentaram extensas áreas de necrose, úlceras, infiltrado neutrofílico, além de mineralização. Houve aumento de deposição de colágeno no tratamento CTMs + DAP, no entanto, a vascularização permaneceu inalterada. Este é o primeiro relato usando CTMs e CTMs + DAP como tratamento para loxoscelismo cutâneo e mais estudos são necessários para determinar seu uso como terapia alternativa para lesões demonecróticas causadas pela aranha Loxosceles.

Abstract This study aimed to evaluate the efficacy of mesenchymal stem cells (MSC), alone or associated with dapsone (DAP), in treating dermonecrotic wounds caused by Loxosceles laeta venom. Twenty-five male rabbits were distributed into five groups. Negative control received ultrapure water (C-), whilst all other groups were injected with 20 μg of L. laeta venom. After 4 hours, each group received one of the following treatments: PBS (C+), DAP, MSC, and DAP+MSC. Animals were evaluated daily and photographic records made for analysis of wound area. Twelve days after, animals were euthanized and skin samples removed for histological analysis. We observed that DAP showed the best percentage of wound contraction at day 3. In the treatments using MSCs, a negative value of wound contraction was observed for the isolated MSCs, as well as a lower contraction value for the association of the MSC + DAP when compared to PBS, probably, by the increase in initial infammation after the application of stem cells, due to the fact that MSCs secrete a broad spectrum of bioactive molecules such as cytokines and growth factors that favor regeneration. Histologically, it was observed that animals of C+ showed extensive areas of necrosis, ulcers, neutrophilic infiltrate, and mineralization. Collagen deposition showed increase in MSC+DAP treatment, however vascularization remained unchanged. This is the first report using MSC and MSC+DAP as a treatment for cutaneous loxoscelism and more studies are needed to determine its use as an alternative therapy for dermonecrotic lesions caused by Loxosceles spider.

Abstract A reconfigurable frequency selective surface, FSS, associating cross dipoles and matryoshka geometries is described in this paper. The proposed reconfigurable FSS uses as active element PIN diodes. With the associated geometries, three resonant frequencies are achieved, two fixed, related to the matryoshka geometry, and one that can be activated or not, related to the cross dipoles geometry. Differently from previous works, an inductor was inserted into the cross dipoles’ horizontal arms, maintaining its resonance for x polarization. The PIN diode inserted into cross dipoles’ vertical arms controls the respective resonance. The design procedures for each geometry, in addition to PIN diode and RF inductor basics are outlined. The expected results are discussed based on the analysis of the resonances of each geometry and the associated geometries, as well as the different PIN diode bias states (OFF and ON). A prototype was fabricated and characterized, obtaining a good agreement between the numerical and experimental results, with a reconfiguration bandwidth of 0.24 GHz, from 2.12 GHz to 2.36 GHz, for a variation of at least 10 dB between the OFF and ON states.

SUMMARY OBJECTIVE: This study aims to evaluate the role of anthropometric clinical indicators of visceral adiposity as predictors of NAFLD, identifying the cutoff points based on gender. METHODS: This was a cross-sectional study conducted in patients with or without NAFLD. Waist circumference (WC), body mass index (BMI), waist-to-height ratio (WHtR), Conicity Index (C Index), and lipid accumulation product (LAP) were evaluated. RESULTS: A total of 107 individuals were evaluated, of which 46.7% were diagnosed with NAFLD. Individuals with NAFLD presented higher values of WC, BMI, C Index, LAP, and WHtR when compared with those without NAFLD (p<0.05). For the total sample, the indicators WC, BMI, WHtR, LAP, and C Index had an area under the receiver operator characteristic curve (AUC) above 0.87, with no difference in the prediction of NAFLD in both sexes. WHtR (AUC=0.934) was the indicator of visceral adiposity with the best discriminatory power for NAFLD, followed by LAP (0.919), WC (0.912), C Index (0.907), and BMI (0.877). CONCLUSIONS: The anthropometric clinical indicators of visceral adiposity showed high performance, especially the WHtR indicator, as NAFLD predictors.

Abstract In reconfigurable frequency selective surface, FSS, bias lines can suppress a resonant frequency. This is a disadvantage, as it reduces a FSS potential application. In this paper, a procedure to recover the suppressed resonant frequency is described. A FSS based on four arms star geometry is considered and its reconfigurability is achieved by the use of varactors, for which bias lines suppress the x polarization resonance. So, dipoles are added to the unit cell geometry recovering this resonance. In order to validate the proposed procedure, a reconfigurable FSS using the varactor SMV1231 (0. 466 pF ≤ Cv < 2. 35 pF) was fabricated and characterized. Numerical and measured results shown a good agreement, confirming that the FSS reconfigurability is preserved and the suppressed resonance recovered.

Abstract Objective We sought to describe the prevalence of microcephaly and to compare the different cutoff points established by the Brazilian Ministry of Health at various times during a Zika virus epidemic. As a secondary aim, we investigated the possible etiology of the microcephaly. Method This retrospective study utilized newborn participants in the Zika Cohort Study Jundiaí. Newborns from the Zika Cohort Study Jundiaí with an accurate gestational age determination and complete anthropometric data were analyzed, and microcephaly was diagnosed according to the INTERGROWTH-21st curve. At delivery, fluids were tested for specific antibodies and for viruses. Brain images were evaluated for microcephaly. Receiver Operating Characteristic curves were plotted to define the accuracy of different cutoff points for microcephaly diagnosis. Results Of 462 eligible newborns, 19 (4.1%) were positive for microcephaly. Cutoff points corresponding to the curves of the World Health Organization yielded the best sensitivity and specificity. Three of the microcephaly cases (15.8%) were positive for Zika virus infections; nine (47.4%) had intrauterine growth restriction; one had intrauterine growth restriction and was exposed to Zika virus; three had a genetic syndrome (15.8%); and three had causes that had not been determined (15.8%). Conclusions Microcephaly prevalence was 4.1% in this study. Cutoff values determined by the World Health Organization had the highest sensitivity and specificity in relation to the standard IG curve. The main reason for microcephaly was intrauterine growth restriction. All possible causes of microcephaly must be investigated to allow the best development of an affected baby.

ABSTRACT The objective of this research is to determine the characteristics that explain the motivation of Mexican entrepreneurs from various viewpoints: chances and needs, flexibility, profit, and their relation with gender and with domestic affairs. The data collection was by survey, with a 32-item instrument, on a sample of entrepreneurs from the municipalities of Puebla and Tlaxcala. The data treatment was carried out by means of multivariate logistic regression. The findings were that the Mexican women entrepreneurs’ motivation is mainly to cooperate with family needs and not to neglect family responsibilities because it is the institutional role assigned to the woman (mother). Another reason for their decision to start a business is that people earn less being waged workers; that is because they suffer from either cultural or social pressures, or they feel frustrated in their jobs. Besides, Mexican entrepreneurs prefer to use external financial sources before risking their owns, and above all, they are driven by expectations or beliefs about the costs- benefits they may obtain, and not necessarily by planned, prepared, or analyzed start-ups.

RESUMEN El objetivo de la investigación fue determinar las características que explican la motivación de emprendedores mexicanos desde ópticas diversas: oportunidades, necesidades económicas, flexibilidad de tiempos, ganancias, y su relación con actividades domésticas o familiares y con su género. La recolección de datos fue por encuesta, con un instrumento de treinta y dos ítems, sobre una muestra de emprendedores de los municipios de Puebla y Tlaxcala. El tratamiento de datos se realizó por medio de una regresión logística multivariable. Los hallazgos encontrados fueron que la mujer emprende motivada por el hecho de que este tipo de ocupación le permite realizar actividades familiares, orillada por el rasgo propio de su sexo (madre), y por la idea de que se gana poco siendo asalariada, es decir, a causa de presiones culturales y sociales sobre ella o porque se siente frustrada en su trabajo. Además, los emprendedores mexicanos deciden utilizar fuentes de recursos externos antes de arriesgar los propios y sobre todo, son impulsados por sus expectativas o creencias sobre los costos-beneficios que puedan obtener y no necesariamente por inicios planeados, preparados o analizados.

The present work describes the comparison of the optical and structural properties between CdTe quantum dots (QD) synthesized in water and in the binary solvent (water + glycerin) via one-pot approach synthesis. The optical properties of the nanocrystals obtained with different synthesis parameters were characterized by UV-visible and photoluminescence spectroscopies. The structural chracterization were performed by Fourier transform infrared spectroscopy (FTIR), zeta potential, size-distribution by dynamic light scattering (DLS), X-ray diffraction (XRD), and also by high-resolution transmission electron microscopy (HRTEM). The optical properties of CdTe QD when synthesized in the binary solvent were better, resulting in the increase of photoluminescence quantum yield (Φƒ). The CdTe QD prepared in 120 min, at pH 10.0, in the Cd:Te molar ratio 20:1, using the molar ratio 1:1.5 of Cd:TGA (thioglycolic acid), exhibited a narrow photoluminescence band and enhanced Φƒ for the samples synthesized in a binary solvent in comparison to water solvent (58.4 and 49.5%, respectively).