1,156 research outputs found

    Evaluation of the Structure-Activity Relationship of Hemoproteins through Physicochemical Studies: Hemoglobins as a Prototype of Biosensor

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    In the present work, we have studied a group of prerequisites in terms of “structure-function relationship” of hemoproteins, especially hemoglobins, emphasizing the role of the heme and its chemical environment in the biochemical and physicochemical properties of the biomolecule. We have discussed the ferrous center and its properties as coordination center; the macrocyclic ligands, especially the porphyrins; the esterochemical and electronic properties of the iron-porphyrins (heme groups); and the interaction between heme groups and globins, which is related to several redox and oligomeric properties of hemoprotein systems and its potential applications with respect to novel materials. One of the main uses of hemoglobins in new materials is also discussed, which is its employment as a biosensor. Therefore, we have discussed the development of novel biosensors based on hemoglobins and their physico-chemical properties as well as on the main molecules of biological relevance that have been detected by these biosensors, such as hydrogen peroxide (H2O2), nitric oxide (NO), and cholesterol, among others. Indeed, several important biomolecules and biological processes can be detected and/or evaluated by devices that present hemoglobins as leading chemical components. Different apparatus are covered with respect to distinct characteristics, such as chemical stability, sensitivity, selectivity, reproducibility, durability, optimum conditions of measurements, etc. and their respective characteristics are analyzed

    Neonatal Near Miss: A Systematic Review

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    Background: The concept of neonatal near miss has been proposed as a tool for assessment of quality of care in neonates who suffered any life-threatening condition. However, there are no internationally agreed concepts or criteria for defining or identifying neonatal near miss. The purpose of this study was to perform a systematic review of studies and markers that are able to identify neonatal near miss cases and predict neonatal mortality. Methods: Electronic searches were performed in the Medline, Embase and Scielo databases, with no time or language restriction, until December 2014. The term "neonatal near miss" was used alone or in combination with terms related to neonatal morbidity/mortality and neonatal severity scores. Study selection criteria involved three steps: title, abstract and full text of the articles. Two researchers performed study selection and data extraction independently. Heterogeneity of study results did not permit the performance of meta-analysis. Results: Following the inclusion and exclusion criteria adopted, only four articles were selected. Preterm and perinatal asphyxia were used as near miss markers in all studies. Health indicators on neonatal morbidity and mortality were extracted or estimated. The neonatal near miss rate was 2.6 to 8 times higher than the neonatal mortality rate. Conclusions: Pragmatic and management criteria are used to help develop the neonatal near miss concept. The most severe cases are identified and mortality is predicted with these criteria. Furthermore, the near miss concept can be used as a tool for evaluating neonatal care. It is the first step in building management strategies to reduce mortality and long-term sequelae.1

    Usability of functional electrical stimulation in upper limb rehabilitation in post-stroke patients: A narrative review

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    Stroke leads to significant impairment in upper limb (UL) function. The goal of rehabilitation is the reestablishment of pre-stroke motor stroke skills by stimulating neuroplasticity. Among several rehabilitation approaches, functional electrical stimulation (FES) is highlighted in stroke rehabilitation guidelines as a supplementary therapy alongside the standard care modalities. The aim of this study is to present a comprehensive review regarding the usability of FES in post-stroke UL rehabilitation. Specifically, the factors related to UL rehabilitation that should be considered in FES usability, as well a critical review of the outcomes used to assess FES usability, are presented. This review reinforces the FES as a promising tool to induce neuroplastic modifications in post-stroke rehabilitation by enabling the possibility of delivering intensive periods of treatment with comparatively less demand on human resources. However, the lack of studies evaluating FES usability through motor control outcomes, specifically movement quality indicators, combined with user satisfaction limits the definition of FES optimal therapeutical window for different UL functional tasks. FES systems capable of integrating postural control muscles involving other anatomic regions, such as the trunk, during reaching tasks are required to improve UL function in post-stroke patients.info:eu-repo/semantics/publishedVersio

    Postural control during turn on the light task assisted by functional electrical stimulation in post stroke subjects

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    Postural control mechanisms have a determinant role in reaching tasks and are typically impaired in post-stroke patients. Functional electrical stimulation (FES) has been demonstrated to be a promising therapy for improving upper limb (UL) function. However, according to our knowledge, no study has evaluated FES infuence on postural control. This study aims to evaluate the infuence of FES UL assistance, during turning on the light task, in the related postural control mechanisms. An observational study involving ten post-stroke subjects with UL dysfunction was performed. Early and anticipatory postural adjustments (EPAs and APAs, respectively), the weight shift, the center of pressure and the center of mass (CoM) displacement were analyzed during the turning on the light task with and without the FES assistance. FES parameters were adjusted to improve UL function according to a consensus between physiotherapists’ and patients’ perspectives. The ANOVA repeated measures, Paired sample t and McNemar tests were used to compare postural control between the assisted and non-assisted conditions. When the task was assisted by FES, the number of participants that presented APAs increased (p= 0.031). UL FES assistance during turning on the light task can improve postural control in neurological patients with UL impairments.info:eu-repo/semantics/publishedVersio

    Effect of process parameters on surface texture generated by laser polishing of additively manufactured Ti-6Al-4V

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    Although there have been numerous attempts to define how different laser polishing parameters affect the generated surface roughness, there has been no detailed investigation of how their effects can be combined to optimize the process. This paper applies statistical analysis to model and predict the resulting surface roughness for laser post-processing of components made of Ti-6Al-4V and produced by laser powder bed fusion. This model is based on analysis of a wide ranging experimental programme investigating how the interaction of the governing parameters, i.e., laser power, number of repetitions, axial feed rate, scanning speed, and focal position, affected surface roughness. The experimental programme was the result of a robust Design of Experiments analysis and experimental analysis using ANOVA. It is expected that the outcomes will contribute towards the understanding of how the governing parameters influence the laser polishing process and final surface roughness, and would be a tool for optimizing their selection. The results of the ANOVA (analysis of variance) revealed that the most significant parameters are scanning speed followed by laser power and then axial feed rate. In addition, a clear tendency for the estimated Ra to decrease with the increase in laser power at lower values of axial feed rate and of scanning speed, and a focal position in the region of 2 mm. It is noted that the process parameters were varied over wide ranges, including extreme values, which made it difficult to accurately model the dependent variable over the full range of experimental trials

    Impact of body and orofacial appearance on life satisfaction among Brazilian adults

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    Aims 1. to elaborate a general model of physical appearance taking into account body image (BI) and orofacial appearance (OA) components; and 2. to evaluate the impact of BI and OA on life satisfaction among Brazilian adults. Methods This is a cross-sectional observational study. The cognitive, behavioral, affective, and satisfaction/ dissatisfaction aspects of BI, the satisfaction and psychosocial impact of OA, and life satisfaction were evaluated by self-reported psychometric scales. Principal Component Analysis and Parallel Analysis were performed. Structural equation models were elaborated to estimate the impact of BI and OA on life satisfaction. The fit of the models was verified and the significance of the path estimates (β) was evaluated using z-tests (α = 5%). Results A total of 1,940 individuals participated in the study (age: mean = 24.8, standard deviation = 5.7 years; females = 70.1%). In the male sample, three physical appearance factors were retained (OA, cognitive and behavioral components of BI, and affective and satisfaction/dissatisfaction components of BI). In the female sample, two factors were retained (OA and all components of BI). All factors had significant impact on life satisfaction (β = |0.26|-|0.48|, p<0.001) in both samples. Individuals dissatisfied with BI and OA had lower levels of life satisfaction. For men, the affective and satisfaction components of BI had a greater impact on life satisfaction (β = 0.48, p<0.001) than the other factors (β =] -0.30;-0.25[, p<0.001). For women, both BI and OA had a similar impact (BI: β = -0.30, p<0.001; OA: β = -0.32, p<0.001). Conclusion BI and OA formed distinct clusters in the physical appearance evaluation. Physical appearance was perceived differently by men and women, fostering discussion about the sociocultural construction of the body. BI and OA had a significant impact on life satisfaction and should be considered in assessment and treatment protocols.info:eu-repo/semantics/publishedVersio

    Blocking inos and endoplasmic reticulum stress synergistically improves insulin resistance in mice

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    Recent data show that iNOS has an essential role in ER stress in obesity. However, whether iNOS is sufficient to account for obesity-induced ER stress and Unfolded Protein Response (UPR) has not yet been investigated. In the present study, we used iNOS knockout mice to investigate whether high-fat diet (HFD) can still induce residual ER stress-associated insulin resistance. Methods: For this purpose, we used the intraperitoneal glucose tolerance test (GTT), euglycemic-hyperinsulinemic clamp, western blotting and qPCR in liver, muscle, and adipose tissue of iNOS KO and control mice on HFD. Results: The results of the present study demonstrated that, in HFD fed mice, iNOS-induced alteration in insulin signaling is an essential mechanism of insulin resistance in muscle, suggesting that iNOS may represent an important target that could be blocked in order to improve insulin sensitivity in this tissue. However, in liver and adipose tissue, the insulin resistance induced by HFD was only partially dependent on iNOS, and, even in the presence of genetic or pharmacological blockade of iNOS, a clear ER stress associated with altered insulin signaling remained evident in these tissues. When this ER stress was blocked pharmacologically, insulin signaling was improved, and a complete recovery of glucose tolerance was achieved. Conclusions: Taken together, these results reinforce the tissue-specific regulation of insulin signaling in obesity, with iNOS being sufficient to account for insulin resistance in muscle, but in liver and adipose tissue ER stress and insulin resistance can be induced by both iNOS-dependent and iNOS-independent mechanisms62206218FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2012/15009-0; 2016/07122-2sem informaçãosem informaçã

    Neonatal near miss: the need for a standard definition and appropriate criteria and the rationale for a prospective surveillance system

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    In Latin American, there is currently a regional action with the main purposes of putting the concept of severe neonatal morbidity in practice and formulating proposals for interventions. A general overview of neonatal health conditions, including morbidity and mortality, is provided to update regional knowledge on the topic. An example of the development and implementation of the concept of maternal near miss is also provided, followed by results from a systematic review covering all previously published studies on Neonatal Near Miss. Finally, some proposals for building a common concept on the topic and for launching a prospective surveillance study are presented. A Neonatal Near Miss is a neonate who had a severe morbidity (organ dysfunction or failure) but who survived this condition within the first 27 days of life. The pragmatic criteria recommended to be used are as follows: birth weight below 1700 g, Apgar score below 7 at 5 minutes of life and gestational age below 33 weeks. As a proxy for organ dysfunction, the following management criteria are also confirmed: parenteral therapeutic antibiotics; nasal continuous positive airway pressure; any intubation during the first 27 days of life; phototherapy within the first 24 h of life; cardiopulmonary resuscitation; the use of vasoactive drugs, anticonvulsants, surfactants, blood products and steroids for refractory hypoglycemia and any surgical procedure. Although this study starts from a regional perspective, this topic is clearly globally relevant. All nations, especially low and middle-income countries, could benefit from the proposed standardization701282082
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