Parametric failure analysis of metal-based composites

Metal-based composites can fail as a consequence of the growth and coalescence of micro-voids introduced with the manufacturing process. These detrimental phenomena influence the overall performance of the material to different extents since the macroscopic characteristics depend on both the local constitutive properties and geometry patterns, which promote various stress concentration and strain localization effects. The understanding of the different situations that arise in this context is often assisted by numerical simulations based on the GNT constitutive model, first proposed by Gurson (1977) and then refined by Needleman and Tvergaard (1984). However, exploring the influence of the most relevant material parameters on the composite response can be excessively time consuming. Therefore, traditional simulations based on non-linear finite element methods can be replaced by surrogate analytical approximations, which do not involve large computing costs but exhibit accuracy and sensitivity to the model parameters consistent with the practical applications. Some examples are presented in this contribution

3D Scan of Hardness Imprints for the Non-destructive In-Situ Structural Assessment of Operated Metal Components

The structural integrity of operated components can be assessed by non-destructive mechanical tests performed in-situ with portable instruments. Particularly promising in this context are small scale hardness tests supplemented by the mapping of the residual imprints left on metal surfaces. The data thus collected represent the input of inverse analysis procedures, which determine the material characteristics and their evolution over time. The reliability of these estimates depends on the accuracy of the geometry scans and on the robustness of the data filtering and interpretation methodologies. The objective of the present work is to evaluate the accuracy of the 3D reconstruction of the residual deformation produced on metals by hardness tests performed at a few hundred N load. The geometry data are acquired by portable optical microscopes with variable focal distance. The imperfections introduced by the imaging system, which may not be optimized for all ambient conditions when used in automatic mode, are analysed. Representative examples of the output produced by the scanning tool are examined, focusing attention on the experimental disturbances typical of onsite applications. Proper orthogonal decomposition and data reduction techniques are applied to the information returned by the instrumentation. The essential features of the collected datasets are extracted and the main noise is removed. The results of this investigation show that the accuracy achievable with the considered equipment and regularization procedures can support the development of reliable diagnostic analyses of metal components in existing structures and infrastructures

Paracetamol and antibiotics in childhood and subsequent development of wheezing/asthma: association or causation?

Several studies found an association between early administration of paracetamol and antibiotics and development of wheezing. This could be due to confounding: wheeze and asthmatic symptoms in early childhood are difficult to distinguish from respiratory tract infections that are widely treated with these drugs; in case of persistence of symptoms up to school age, this could explain the observed relationship

The Pap smear screening as an occasion for smoking cessation and physical activity counselling: baseline characteristics of women involved in the SPRINT randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>Gender-specific smoking cessation strategies have rarely been developed. Evidence of effectiveness of physical activity (PA) promotion and intervention in adjunct to smoking cessation programs is not strong. SPRINT study is a randomized controlled trial (RCT) designed to evaluate a counselling intervention on smoking cessation and PA delivered to women attending the Italian National Health System Cervical Cancer Screening Program. This paper presents study design and baseline characteristics of the study population.</p> <p>Methods/Design</p> <p>Among women undergoing the Pap examination in three study centres (Florence, Turin, Mantua), participants were randomized to the smoking cessation counselling [S], the smoking cessation + PA counselling [S + PA], or the control [C] groups. The program under evaluation is a standard brief counselling on smoking cessation combined with a brief counselling on increasing PA, and was delivered in 2010. A questionnaire, administered before, after 6 months and 1 year from the intervention, was used to track behavioural changes in tobacco use and PA, and to record cessation rates in participants.</p> <p>Discussion</p> <p>Out of the 5,657 women undergoing the Pap examination, 1,100 participants (55% of smokers) were randomized in 1 of the 3 study groups (363 in the S, 366 in the S + PA and 371 in the C groups). The three arms did not differ on any demographic, PA, or tobacco-use characteristics. Recruited smokers were older, less educated than non-participant women, more motivated to quit (33% vs.9% in the Preparation stage, <it>p </it>< 0.001), smoked more cigarettes per day (12 vs.9, <it>p </it>< 0.001), and were more likely to have already done 1 or more quit attempts (64% vs.50%, <it>p </it>< 0.001). The approach of SPRINT study appeared suitable to enrol less educated women who usually smoke more and have more difficulties to quit.</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN52660565">ISRCTN52660565</a></p

Psychosocial interventions for community-dwelling people following diagnosis of mild to moderate dementia: findings of a systematic scoping review

National policies and evidence reviews recommend psychosocial interventions (PIs) as an essential support, particularly in the period following dementia diagnosis. However, availability and uptake of these interventions are comparatively low. One of the reasons for this is that clinicians lack information about what might be provided and the potential benefits of different interventions. This article identifies and describes PIs for community-dwelling people following diagnosis of mild to moderate dementia and presents the available evidence to inform practice decisions. A systematic scoping review was employed to map the evidence relating to PIs for this group. This identified 63 relevant studies, testing 69 interventions, which could be grouped into 6 intervention categories: 20 cognition-oriented, 11 behavior-oriented, 11 stimulation-oriented, 13 emotion-oriented, 5 social-oriented, and 9 multimodal. There were three targets for outcome measurement of these PIs: the person with dementia, the family caregiver, and the person–caregiver dyad. Over 154 outcome measures were identified in the studies, with outcomes measured across 11 main domains. The lack of a classification framework for PIs means it is difficult to create a meaningful synthesis of the breadth of relevant evidence to guide clinical practice. Possible dimensions of a classification framework are proposed to begin to address this gap

Cognitive and memory training in adults at risk of dementia: A Systematic Review

<p>Abstract</p> <p>Background</p> <p>Effective non-pharmacological cognitive interventions to prevent Alzheimer's dementia or slow its progression are an urgent international priority. The aim of this review was to evaluate cognitive training trials in individuals with mild cognitive impairment (MCI), and evaluate the efficacy of training in memory strategies or cognitive exercises to determine if cognitive training could benefit individuals at risk of developing dementia.</p> <p>Methods</p> <p>A systematic review of eligible trials was undertaken, followed by effect size analysis. Cognitive training was differentiated from other cognitive interventions not meeting generally accepted definitions, and included both cognitive exercises and memory strategies.</p> <p>Results</p> <p>Ten studies enrolling a total of 305 subjects met criteria for cognitive training in MCI. Only five of the studies were randomized controlled trials. Meta-analysis was not considered appropriate due to the heterogeneity of interventions. Moderate effects on memory outcomes were identified in seven trials. Cognitive exercises (relative effect sizes ranged from .10 to 1.21) may lead to greater benefits than memory strategies (.88 to -1.18) on memory.</p> <p>Conclusions</p> <p>Previous conclusions of a lack of efficacy for cognitive training in MCI may have been influenced by not clearly defining the intervention. Our systematic review found that cognitive exercises can produce moderate-to-large beneficial effects on memory-related outcomes. However, the number of high quality RCTs remains low, and so further trials must be a priority. Several suggestions for the better design of cognitive training trials are provided.</p

Cognitive and cognitive-motor interventions affecting physical functioning: A systematic review

Background Several types of cognitive or combined cognitive-motor intervention types that might influence physical functions have been proposed in the past: training of dual-tasking abilities, and improving cognitive function through behavioral interventions or the use of computer games. The objective of this systematic review was to examine the literature regarding the use of cognitive and cognitive-motor interventions to improve physical functioning in older adults or people with neurological impairments that are similar to cognitive impairments seen in aging. The aim was to identify potentially promising methods that might be used in future intervention type studies for older adults. Methods A systematic search was conducted for the Medline/Premedline, PsycINFO, CINAHL and EMBASE databases. The search was focused on older adults over the age of 65. To increase the number of articles for review, we also included those discussing adult patients with neurological impairments due to trauma, as these cognitive impairments are similar to those seen in the aging population. The search was restricted to English, German and French language literature without any limitation of publication date or restriction by study design. Cognitive or cognitive-motor interventions were defined as dual-tasking, virtual reality exercise, cognitive exercise, or a combination of these. Results 28 articles met our inclusion criteria. Three articles used an isolated cognitive rehabilitation intervention, seven articles used a dual-task intervention and 19 applied a computerized intervention. There is evidence to suggest that cognitive or motor-cognitive methods positively affects physical functioning, such as postural control, walking abilities and general functions of the upper and lower extremities, respectively. The majority of the included studies resulted in improvements of the assessed functional outcome measures. Conclusions The current evidence on the effectiveness of cognitive or motor-cognitive interventions to improve physical functioning in older adults or people with neurological impairments is limited. The heterogeneity of the studies published so far does not allow defining the training methodology with the greatest effectiveness. This review nevertheless provides important foundational information in order to encourage further development of novel cognitive or cognitive-motor interventions, preferably with a randomized control design. Future research that aims to examine the relation between improvements in cognitive skills and the translation to better performance on selected physical tasks should explicitly take the relation between the cognitive and physical skills into account.ISSN:1471-231

Entendendo a anestesia inalatória na Cesária: revisão sistemática

Introduction: Inhalation anesthesia in cesarean section is a commonly employed anesthetic approach to provide analgesia and anesthesia during the cesarean surgical procedure. This method utilizes inhalation-administered anesthetic agents, usually through a face mask or endotracheal tube, to induce and maintain the required anesthetic state. Methodology: A systematic literature review on "Understanding Inhalation Anesthesia in Cesarean Section" was conducted based on rigorous criteria to ensure the selection of relevant and high-quality studies. The search was delimited by the descriptors "Anesthesia," "Inhalation," "Cesarean Section," and "Inhalation Anesthesia," focusing on the last 5 years (2019 to 2023) and research conducted from April 20, 2023, to November 29, 2023. Result: Pre-delivery procedures required careful anesthetic attention, and the adopted approach could vary significantly depending on the natureIntrodução: A anestesia inalatória na cesariana é uma abordagem anestésica comumente empregada para fornecer analgesia e anestesia durante o procedimento cirúrgico de cesariana. Este método utiliza agentes anestésicos administrados por inalação, geralmente através de uma máscara facial ou tubo endotraqueal, para induzir e manter o estado anestésico necessário. Metodologia: Uma revisão sistemática de literatura sobre "Entendendo a Anestesia Inalatória na Cesariana" foi elaborada com base em critérios rigorosos para garantir a seleção de estudos relevantes e de qualidade. A pesquisa foi delimitada pelos descritores Anesthesia, Inhalatio, Cesarean Section, Inhalation Anesthesia, com foco nos últimos 5 anos (2019 a 2023) e pesquisas realizadas no período de 20/04/2023 a 29/11 /2023. Resultado: Os procedimentos pré-parto exigiram um cuidado de atenção anestésica, sendo que a abordagem adotada pode variar significativamente de acordo com a natureza e a invasividade da intervenção planejada. Desde procedimentos mais simples até intervenções mais complexas, a escolha da anestesia desempenha um papel crucial no conforto do paciente e no sucesso técnico do procedimento. Conclusão: Os agentes anestésicos inalatórios mais comuns incluem o óxido nitroso, sevoflurano, desflurano e isoflurano. O óxido nitroso é frequentemente utilizado em combinação com outros agentes para fornecer analgesia suplementar. Esses agentes atuam no sistema nervoso central