The All4Children project to assess the initial implementation of the Integrated Model of Family Foster Care in Portugal: A description of the study protocol.

BACKGROUND: The All4Children project addresses the urgent need to transition from institutionalization to family-based care for out-of-home children in Portugal. Despite evidence highlighting the detrimental effects of institutionalization, only a small percentage of children (less than 4%) are currently placed in family foster care in the country. In response to European directives for deinstitutionalization, Portuguese legislation now prioritizes non-kinship family foster care as the preferred alternative for young children in need of care. To facilitate this transition, the Integrated Model of Family Foster Care (MIAF) was developed, offering a comprehensive framework covering the entire spectrum of family foster care. OBJECTIVE: This research aims to investigate the initial implementation stage of the MIAF to promote high-quality family foster care in Portugal. METHOD: The study will conduct a mixed-method and longitudinal research project in family foster care agencies across different regions of Portugal, focusing on evaluating the implementation and outcomes of the MIAF model using a multi-informant and multi-method approach. The participants will include caseworkers, children aged 0-9 years entering foster care, and their respective foster families enrolled in the MIAF program. Process evaluation will assess fidelity, feasibility, appropriateness, and acceptability of MIAF modules, while outcome evaluation will examine child safety, stability, well-being, as well as foster family well-being and quality of relational care. OUTCOMES: The insights gained from this research initiative will serve as a foundation for the ongoing enhancement of MIAF. Consequently, this project has the capacity to advance evidence-based child welfare practices by refining processes and strategies to better serve vulnerable children and youth. CONCLUSION: Facilitated by a multidisciplinary team, this project will contribute to advancing research in the field, enhancing practice, and informing policy during a pivotal stage of deinstitutionalization in Portugal.

Maltreatment history and internalizing and externalizing symptoms in out-ofhome care: a three-level meta-analysis / La historia del maltrato y los síntomas internalizantes y externalizantes en acogimiento fuera del hogar: un meta-análisis de tres niveles

Background/Aim: Young people in care may show significant mental health difficulties because of previous adverse experiences, such as maltreatment or violence. However, no meta-analyses have been conducted on this topic. We aim to identify the role of previous maltreatment in current symptoms of children and adolescents in out-of-home care. Method: A search in Academic Search Complete, PsycArticles, PsycInfo, Psychology and Behavioral Sciences Collection, ERIC, Medline, Web of Science and Scopus databases was conducted. Studies were included if they were empirical and quantitative, involved school-aged children and adolescents, assessed maltreatment before placement in care and current internalizing and externalizing symptoms. Multiple effect sizes were extracted from each primary study, and a three-level meta-analysis for each type of maltreatment associated with internalizing and externalizing symptoms was conducted. Results: The search yielded 122 effects sizes from 28 studies. Results indicated significant overall effects of general maltreatment (r = .260), abuse (emotional/physical) (r = .135) and sexual abuse (r = .247) on internalizing symptoms. In relation to externalizing symptoms, overall effects of abuse (emotional/physical) (r = .097) and sexual abuse (r = .187) were identified. The overall effect sizes of neglect were neither significant for internalizing or externalizing symptoms. A set of moderators was tested, and significant effects were found for the type of maltreatment measure on internalizing symptoms and for gender on externalizing symptoms. Conclusions: This study provides new insights beyond previous systematic reviews, as we were able to disentangle the associations between maltreatment and internalizing and externalizing symptoms in out-of-home care. (AU)

Antecedentes/Objetivos: Los niños y adolescentes de protección presentan problemas significativos en la salud mental debidos a experiencias previas adversas como el maltrato o la violencia. A pesar de ello no se han realizado meta-análisis sobre esto. Se diseñó una revisión meta-analítica con el objetivo de conocer el papel que desempeña el maltrato sufrido en los síntomas que experimentan los niños y adolescentes en acogida fuera del hogar. Método: Se llevó a cabo una búsqueda bibliográfica en las bases de datos Academic Search Complete, PsycArticles, PsycInfo, Psychology y Behavioral Sciences Collection, ERIC, Medline, Web of Science y Scopus. Se incluyeron los estudios que eran empíricos y cuantitativos, concernían a niños y adolescentes en edad escolar, evaluaban el maltrato antes de que fuesen dados en acogida y también los síntomas actuales internalizantes y externalizantes. De cada estudio primario se extrajeron varios tamaños del efecto y se ejecutaron meta-análisis de tres niveles para cada tipo de maltrato asociado con síntomas internalizantes y externalizantes. Resultados: La búsqueda arrojó 122 tamaños de efecto provenientes de 28 estudios. Los resultados mostraron efectos generales significativos del maltrato general (r = .260), el abuso (físico/emocional) (r = .135) y el abuso sexual (r = .247) en los síntomas internalizantes. En cuanto a los síntomas externalizantes se encontraron efectos globales del abuso (emocional/físico) (r = .097) y abuso sexual (r = .187). Los tamaños del efecto globales de la negligencia fueron no significativos tanto ni para los síntomas internalizantes como para los externalizantes. También se estudiaron los efectos de moderadores, hallándose efectos significativos del tipo de medida del maltrato en los síntomas internalizantes y del género en los síntomas externalizantes. Conclusiones: ... (AU)

Is it the Child's Fault? Maternal Attributions in Child Abuse and Neglect.

BACKGROUND: Among the parental cognitions explaining maladaptive parenting, attributions about a child's misbehavior seem important. However, there is little research on neglectful parents, and the different patterns of parental attributions associated with child abuse and child neglect are still underexplained. The current study examines parental attributions associated with child abuse and child neglect. METHOD: Mothers ( N = 218) were asked to evaluate vignettes describing child transgressions, half of which were followed by situational information. Child abuse and child neglect were evaluated through mothers' and professionals' reports. RESULTS: Preliminary results indicated that the child's age and maternal socioeconomic status were significantly correlated with attributions and child abuse and neglect scores and thus were controlled in the models. The results from hierarchical regressions indicated that dispositional attributions were associated with higher abuse scores (reported by mothers), even in the presence of situational information. Likewise, dispositional attributions were associated with higher neglect scores (reported by professionals), but the effect was no longer significant in the presence of situational information. CONCLUSIONS: These findings contribute to the current socio-cognitive approaches to child maltreatment and provide relevant input for understanding the different attributional mechanisms underlying child abuse and neglect.

Information and communication technologies-assisted after-hours work: A systematic literature review and meta-analysis of the relationships with work-family/life management variables.

The phenomenon of information and communication technology (ICT)-assisted after-hours work has led to rising academic interest in examining its impact on workers' lives. ICT-assisted after-hours work may intrude on the home domain and contribute to higher work-family/life conflict, lower work-family/life balance, or higher work-family/life enrichment (the last one owing to the acquisition of competencies transferable to the home domain). Additionally, owing to cultural and societal differences in gender roles, the relationships between ICT-assisted after-hours work and work-family/life management variables may differ between female and male workers. To analyze the current empirical findings, this study performed a literature review with 38 articles and a meta-analysis with 37 articles. Our findings showed that ICT-assisted after-hours work was positively related to work-family/life enrichment (r = 0.335, p < 0.001; 95% CI [0.290, 0.406]), but also to work-family/life conflict (r = 0.335, p < 0.001; 95% CI [0.290, 0.406]). However, neither gender nor pre-/post-COVID significantly affect the relationship between ICT-assisted after-hours work and work-family/life conflict. Finally, future research and implications are discussed.

Is it the Child’s Fault? Maternal Attributions in Child Abuse and Neglect / ¿Es Culpa del Niño? Atribuciones Maternas en el Abuso y la Negligencia Infantil

Background: Among the parental cognitions explaining maladaptive parenting, attributions about a child’s misbehavior seem important. However, there is little research on neglectful parents, and the different patterns of parental attributions associated with child abuse and child neglect are still underexplained. The current study examines parental attributions associated with child abuse and child neglect. Method: Mothers (N = 218) were asked to evaluate vignettes describing child transgressions, half of which were followed by situational information. Child abuse and child neglect were evaluated through mothers’ and professionals’ reports. Results: Preliminary results indicated that the child’s age and maternal socioeconomic status were significantly correlated with attributions and child abuse and neglect scores and thus were controlled in the models. The results from hierarchical regressions indicated that dispositional attributions were associated with higher abuse scores (reported by mothers), even in the presence of situational information. Likewise, dispositional attributions were associated with higher neglect scores (reported by professionals), but the effect was no longer significant in the presence of situational information. Conclusions: These findings contribute to the current socio-cognitive approaches to child maltreatment and provide relevant input for understanding the different attributional mechanisms underlying child abuse and neglect.(AU)

Antecedentes: Entre las cogniciones parentales que explican la parentalidad desadaptativa, las atribuciones sobre el comportamiento del niño parecen importantes. Sin embargo, hay pocas investigaciones sobre los padres negligentes, y los patrones de atribuciones parentales que se asocian con el abuso y la negligencia siguen sin explicarse. Éste estudio examina las atribuciones parentales asociadas con el abuso y la negligencia infantil. Método: La muestra estaba compuesta por 218 madres que evaluaron viñetas que describían transgresiones infantiles, la mitad con información situacional. Abuso y negligencia se evaluaron a través de informes de madres y profesionales. Resultados: Los resultados indicaron que la edad del niño y el estatus socioeconómico estaban correlacionados con las atribuciones y con el abuso y negligencia, por lo que fueron controlados en los modelos. Los resultados de las regresiones jerárquicas indicaron que las atribuciones disposicionales se asociaron con el abuso (informes de madres), incluso en presencia de información situacional. Las atribuciones disposicionales se asociaron con la negligencia (informes de profesionales), pero no hay efecto en presencia de información situacional. Conclusiones: Estos hallazgos corroboran a los actuales enfoques sociocognitivos del maltrato infantil y proporcionan aportaciones relevantes para entender los diferentes mecanismos atribucionales que subyacen al abuso y la negligencia infantil.(AU)

Cuidado e questões de gênero: invisibilidade, paternalismo, autossacrifício e a crise de cuidados. Entrevista com Ilze Zirbel / Care and gender issues: invisibility, paternalism, self-sacrifice and the care crisis. Interview with Ilze Zirbel / Cuidado y cuestiones de genero: invisibilidad, paternalismo, autosacrificio y crisis del cuidado. Entrevista con Ilze Zirbel

Este texto apresenta uma conversa-entrevista entre um grupo de pesquisa sobre as práticas de profissionais de saúde atuantes na Atenção Básica em Saúde e a Dra em filosofia Ilze Zirbel, pesquisadora do campo das Teorias do Cuidado. A conversa ocorreu durante um encontro do grupo de pesquisa, na cidade de Santos, no dia 29.11.2019 e foi registrada em áudio sendo, em seguida, transcrita e editada na forma de entrevista. Nela são abordadas questões de gênero, classe e raça envolvidas nas atividades e relações de cuidado, o que toca nas temáticas do privilégio e da exploração, do autossacrifício e da coerção, bem como da autonomia e da interdependência de seres humanos. O pano de fundo é o da necessidade de políticas públicas visando o cuidado da população e desenvolvimento do senso de cuidado tanto em homens quanto em mulheres.

This text presents a conversation-interview between a research group on the practices of health professionals working in Primary Health Care and a researcher in the field of Care Theories. It addresses issues of gender, class and race involved in care activities and relationships, which touches on the themes of privilege and exploitation, self-sacrifice and coercion, as well as autonomy and interdependence. The background is the need for public policies aimed at the care of the population and the development of a sense of care for both men and women.

Este texto presenta una conversación-entrevista entre un grupo de investigación sobre las prácticas de los profesionales de la salud que trabajan en Atención Primaria y un investigador en el campo de las Teorías de la Atención. Aborda temas de género, clase y raza involucrados en las actividades y relaciones de cuidado, que toca los temas de privilegio y explotación, autossacrificio y coacción, así como autonomía e interdependencia. El trasfondo es la necesidad de políticas públicas orientadas al cuidado de la población y al desarrollo de un sentido de cuidado tanto para hombres como para mujeres.

Parental Attitudes in Child Maltreatment.

An information-processing approach to maladaptive parenting suggests that high-risk and maltreating parents are likely to hold inaccurate and biased preexisting cognitive schemata about child development and child rearing. Importantly, these schemas, which may include values, beliefs, expectations, and attitudes, are known to influence the way parents perceive and subsequently act toward their children. However, the few studies specifically addressing parental attitudes only considered global maltreatment, not distinguishing abuse from neglect. Moreover, few have considered dual-process models of cognition, relying mostly on the explicit level of parental attitudes that can be prone to various biases. Based on the Social Information Processing (SIP) model of child abuse and neglect, this study examines the association of parents preexisting cognitive schemata, namely explicit and implicit parental attitudes, and child abuse and neglect. A convenience sample of 201 mothers (half with at least one child referred to child protection services) completed a measure of explicit parental attitudes and a speed-accuracy task related to parenting. Abuse and neglect were measured with self-report and professionals-report instruments. Overall, the results support the hypothesis that maladaptive parenting is related with more biased preexisting cognitive schemas, namely attitudes related to parenting, but only for neglect and particularly when reported by professionals. Moreover, the results observed with both the explicit and implicit measures of attitudes were convergent, with mothers presenting more inadequate explicit attitudes also exhibiting an overall lower performance in the implicit attitudes task. This study is likely to contribute to the SIP framework of child abuse and neglect, particularly for the elucidation of the sociocognitive factors underlying maladaptive parenting, while also providing relevant cues for prevention and intervention programs.

Recognizing children's emotions in child abuse and neglect.

Past research has suggested that parents' ability to recognize their children's emotions is associated with an enhanced quality of parent-child interactions and appropriateness of parental caregiving behavior. Although this association has also been examined in abusive and neglectful parents, the results are mixed and do not adequately address child neglect. Based on the Social Information Processing model of child abuse and neglect, we examined the association between mothers' ability to recognize children's emotions and self- and professionals-reported child abuse and neglect. The ability to recognize children's emotions was assessed with an implicit valence classification task and an emotion labeling task. A convenience sample of 166 mothers (78 with at least one child referred to Child Protection Services) completed the tasks. Child abuse and neglect were measured with self-report and professionals-report instruments. The moderating role of mothers' intellectual functioning and socioeconomic status were also examined. Results revealed that abusive mothers performed more poorly on the negative emotions recognition task, while neglectful mothers demonstrated a lower overall ability in recognizing children's emotions. When classifying the valence of emotions, mothers who obtained higher scores on child neglect presented a higher positivity bias particularly when their scores in measures of intellectual functioning were low. There was no moderation effect for socioeconomic status. Moreover, the results for child abuse were mainly observed with self-report measures, while for child neglect, they predominantly emerged with professionals-report. Our findings highlight the important contribution of the social information processing model in the context of child maltreatment, with implications for prevention and intervention addressed.

Victimization Experiences and Well-Being in Adulthood: A Systematic Review and Meta-Analysis.

Scientific research has explored the impact of violence during adulthood on psychopathology. Fewer efforts have been made from a positive theoretical framework, and no systematic evidence has been provided. This manuscript describes a literature review and meta-analysis on the relationship between victimization experiences and well-being in adulthood. A literature review was performed, and 27 studies met the inclusion criteria for the systematic review 16 for the meta-analysis. The meta-analysis yielded a medium and significant overall effect size (r = -0.309, p < .001), which indicated that greater victimization experiences partly explain lower well-being outcomes. A set of theoretical and methodological issues are discussed, specifically considering the conceptualization of victimization and well-being as well as the studies design, sample characteristics, measures, and data analysis. Derived from this integrative discussion, some recommendations are also provided for future research.

The social information processing model in child physical abuse and neglect: A meta-analytic review.

BACKGROUND: Child maltreatment has been recently examined from a cognitive-behavioral perspective. The Social Information Processing (SIP) model specifies how parental cognitions can be associated with child physical abuse and neglect and suggests that maltreating parents do not adequately respond to the child's needs due to errors/bias in the cognitive processing of child-related information. OBJECTIVE: This study provides two separate meta-analytic reviews of research exploring the role of parents' socio-cognitive variables in shaping child physical abuse and child neglect, identifying the association of each SIP stage to these types of maltreatment. METHOD: After a four-phase systematic literature search based in PRISMA with inter-judges' agreement, 130 effect sizes were extracted from the 51 studies selected. RESULTS: Overall, the effect sizes of the four cognitive stages of the model were significant for physical abuse and ranged from small (r = .190 for parents' interpretations of children's signals) to moderate (r = .315 for parents' perceptions of children's signals). Regarding neglect, only the overall effect of parent's preexisting schemata was significant but small in magnitude (r = .231). CONCLUSIONS: The results of these multilevel meta-analyses support the general hypothesis that physically abusive parents may incur in biases in processing child-related information, but further research is still required regarding neglect. Theoretically this work is likely to provide a more solid framework to understand parental cognitions underlying child maltreatment with potential implications for evaluation and intervention with maltreating or at-risk parents.

MicroRNA expression profiling provides novel insights into immune-related pathways involved in gastric cancer.

Gastric cancer is one of the most common cancers, and an increasing number of studies have found that microRNAs (miRNAs) play essential roles in gastric cancer progression; however, the roles of specific miRNAs involved in the immune response to this disease remain unclear. We compared the miRNA expression in tissues from primary gastric cancer patients and healthy controls to find miRNAs dysregulated in gastric cancer and used bioinformatics tools to determine potential roles of these miRNAs in the immune system. We evaluated 25 primary gastric cancer tissues and five healthy gastric tissues. Quantitative real-time polymerase chain reaction was performed for a set of miRNAs, followed by the prediction of their target genes and functional enrichment analysis of these targets. Analysis of a microarray dataset showed that the miRNA miR-196a-5p was significantly upregulated, while miR-374a-5p and miR-375 were downregulated in gastric cancer patients. In addition, miR-374-5p was significantly downregulated in patients with metastasis compared with its expression levels in non-metastatic patients (p = 0.03). Bioinformatics analysis suggested that the pathways regulated by these differentially expressed miRNAs were related to the immune response, cell adhesion, and cell migration. Most importantly, this study provides a new insight into the potential use of multiple miRNAs to find distinct pathways of immune regulation in gastric cancer.

Subjective ratings and emotional recognition of children's facial expressions from the CAFE set.

Access to validated stimuli depicting children's facial expressions is useful for different research domains (e.g., developmental, cognitive or social psychology). Yet, such databases are scarce in comparison to others portraying adult models, and validation procedures are typically restricted to emotional recognition accuracy. This work presents subjective ratings for a sub-set of 283 photographs selected from the Child Affective Facial Expression set (CAFE [1]). Extending beyond the original emotion recognition accuracy norms [2], our main goal was to validate this database across eight subjective dimensions related to the model (e.g., attractiveness, familiarity) or the specific facial expression (e.g., intensity, genuineness), using a sample from a different nationality (N = 450 Portuguese participants). We also assessed emotion recognition (forced-choice task with seven options: anger, disgust, fear, happiness, sadness, surprise and neutral). Overall results show that most photographs were rated as highly clear, genuine and intense facial expressions. The models were rated as both moderately familiar and likely to belong to the in-group, obtaining high attractiveness and arousal ratings. Results also showed that, similarly to the original study, the facial expressions were accurately recognized. Normative and raw data are available as supplementary material at https://osf.io/mjqfx/.

Bone response to porous alumina implants coated with bioactive materials, observed using different characterization techniques.

BACKGROUND: Implants or implantable devices should integrate into the host tissue faster than fibrous capsule formation, in which the design of the interface is one of the biggest challenges. Generally, bioactive materials are not viable for load-bearing applications, so inert biomaterials are proposed. However, the surface must be modified through techniques such as coating with bioactive materials, roughness and sized pores. The aim of this research was to validate an approach for the evaluation of the tissue growth on implants of porous alumina coated with bioactive materials. METHODS: Porous alumina implants were coated with 45S5 Bioglass® (BG) and hydroxyapatite (HA) and implanted in rat tibiae for a period of 28 days. Ex vivo resections were performed to analyze osseointegration, along with histological analysis, Scanning Electron Microscopy with Energy Dispersive X-Ray spectroscopy (SEM-EDX) line scanning, radiography and biomechanical testing. RESULTS: Given that the process of implant integration needs with the bone tissue to be accelerated, it was then seen that BG acted to start the rapid integration, and HA acted to sustaining the process. CONCLUSIONS: Inert materials coated with bioglass and HA present a potential for application as bone substitutes, preferably with pores of diameters between 100 µm and 400 µm and, restrict for smaller than 100 µm, because it prevents pores without organized tissue formation or vacant. Designed as functional gradient material, stand out for applications in bone tissue under load, where, being the porous surface responsible for the osseointegration and the inner material to bear and to transmit the loads.

Corrosion and microstructural characterization of martensitic stainless steels submitted to industrial thermal processes for use in surgical tools

INTRODUCTION: The mechanical properties and corrosion resistance of a material are dependent on its microstructure and can be modified by phase transformation. When a phase transformation occurs in a material it usually forms at least one new phase, with physical-chemical characteristics that differ from the original phase. Moreover, most phase transformations do not occur instantly. This paper presents an evaluation of the phase transformation of martensitic stainless steels ASTM 420A and ASTM 440C when submitted to different thermal processes. METHODS: Dilatometry tests were performed with several continuous heating and cooling rates in order to obtain the profiles of the continuous heating transformation (CHT) and continuous cooling transformation (CCT) diagrams for these two types of steel. Also, the temperature ranges for the formation of the different phases (ferrite and carbides; ferrite; austenite and carbides; non-homogeneous and homogeneous austenite phases) were identified. Rockwell hardness (HRC) tests were performed on all thermally treated steels. Anodic and cathodic potential dynamic polarization measurements were carried out through immersion in enzymatic detergent as an electrolyte for different samples submitted to the thermal processes in order to select the best routes for the heat treatment and to recommend steels for the manufacture of surgical tools. RESULTS: The martensitic transformation temperature tends to increase with increasing temperature for the initiation of cooling. The 440C steel had a higher hardness value than the 420A steel at the austenitizing temperature of 1100 °C. Above the austenitizing temperature of 1100 °C, the material does not form martensite at the cooling rate used, which explains the sharp decline in the hardness values. CONCLUSION: The study reported herein achieved its proposed objectives, successfully investigating the issues and indicating solutions to the industrial problems addressed, which are frequently encountered in the manufacture of surgical instruments.

Biocompatibility of a porous alumina ceramic scaffold coated with hydroxyapatite and bioglass.

This study aimed to evaluate the osteointegration and genotoxic potential of a bioactive scaffold, composed of alumina and coated with hydroxyapatite and bioglass, after their implantation in tibias of rats. For this purpose, Wistar rats underwent surgery to induce a tibial bone defect, which was filled with the bioactive scaffolds. Histology analysis (descriptive and morphometry) of the bone tissue and the single-cell gel assay (comet) in multiple organs (blood, liver, and kidney) were used to reach this aim after a period of 30, 60, 90, and 180 days of material implantation. The main findings showed that the incorporation of hydroxyapatite and bioglass in the alumina scaffolds produced a suitable environment for bone ingrowth in the tibial defects and did not demonstrate any genotoxicity in the organs evaluated in all experimental periods. These results clearly indicate that the bioactive scaffolds used in this study present osteogenic potential and still exhibit local and systemic biocompatibility. These findings are promising once they convey important information about the behavior of this novel biomaterial in biological system and highlight its possible clinical application.

Mammary analogue secretory carcinoma of salivary glands is a lipid-rich tumour, and adipophilin can be valuable in its identification.

AIMS: Mammary analogue secretory carcinoma (MASC) of salivary glands shows morphological similarities to milk-secreting mammary epithelial cells. The aim of this study was to analyse the immunohistochemical expression of adipophilin (a component of milk lipid globule membranes) and of proteins related to secretory mechanisms (STAT5a and mammaglobin) in MASC and other salivary tumours. METHODS AND RESULTS: Ten cases of MASC (all with ETV6 translocation) and 83 other salivary carcinomas were studied. In all MASC cases, adipophilin stained numerous large lipid droplets. These droplets were minute in other salivary carcinomas, except for sebaceous carcinoma. Overexpression of STAT5a was detected in all MASC cases, but only occasionally in other carcinomas. Mammaglobin expression occurred frequently in MASC (70% of cases), whereas, in other carcinomas, it was uncommon and limited. Only MASC showed cytoplasmic reactivity for p63, particularly in papillary-cystic areas. Positivity for S100, vimentin and high molecular weight keratin was observed in 100% of MASC cases. CONCLUSIONS: MASC is a lipid-rich tumour containing large lipid droplets covered by adipophilin. This finding can be included among its defining immunohistochemical features, and possibly represents lactation-like secretory differentiation. Strong expression of STAT5a and cytoplasmic p63 in MASC reinforces this hypothesis.

Mathematical modeling of dilatometric behavior of 420A and 440C martensitic stainless steels used in surgical tools / Modelamento matemático de ensaio dilatométrico em aços inoxidáveis martensíticos 420A e 440C utilizados em ferramental cirúrgico

This research consisted of implementing and evaluating an empirical mathematical model to reproduce analytically the dilatometric behavior of ASTM 420A and ASTM 440C martensitic stainless steels, widely used for manufacturing surgical tools. Martensitic stainless steels can be subdivided into three subgroups: low-carbon, medium-carbon and high-carbon steels. The microstructure of each group is also characteristic as needlelike martensitic; very fine martensitic; and ultra-fine martensitic containing carbides. The proposed method was based on experimental data obtained from the dilatometric testing of the steel samples applying low heating rates. It was possible to determine the formation of phase fields near the equilibrium conditions. The method, being based on empirical data, ensured a greater approximation to the experimental values, verifying that it can be applied as a useful tool in the evaluation of industrial heat treatments for surgical tools.

O presente trabalho consistiu em implementar e avaliar um modelo matemático empírico que reproduz analiticamente o comportamento dilatométrico dos aços inoxidáveis martensíticos ASTM 420A e ASTM 440C, utilizados em ferramental cirúrgico. Aços inoxidáveis martensíticos podem ser subdivididos em três subgrupos, ou seja, baixo carbono; médio carbono e alto carbono. A microestrutura de cada grupo é caracterizada por martensita em forma de agulha; martensita fina e martensita ultra-fina contendo carbetos. A elaboração do método matemático se baseou em dados extraídos de ensaios dilatométricos sob baixas taxas de aquecimento. Foi possível determinar a formação dos campos de fase próximos às condições de equilíbrio. Os resultados obtidos garantiram boa aproximação com os valores experimentais, evidenciando que o modelo aplicado é um instrumento útil na avaliação dos tratamentos térmicos industriais para ferramental cirúrgico.