23 research outputs found

    A computational model of cell viability and proliferation of extrusion-based 3D-bioprinted constructs during tissue maturation process

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    3D bioprinting is a novel promising solution for living tissue fabrication, with several potential advantages in many different applicative sectors. However, the implementation of complex vascular networks remains as one of the limiting factors for the production of complex tissues and for bioprinting scale-up. In this work, a physics-based computational model is presented to describe nutrients diffusion and consumption phenomena in bioprinted constructs. The model - a system of partial differential equations that is approximated by means of the finite element method - allows for the description of cell viability and proliferation, and it can be easily adapted to different cell types, densities, biomaterials, and 3D-printed geometries, thus allowing a preassessment of cell viability within the bioprinted construct. The experimental validation is performed on bioprinted specimens to assess the ability of the model to predict changes in cell viability. The proposed model constitutes a proof of concept of digital twinning of biofabricated constructs that can be suitably included in the basic toolkit for tissue bioprinting

    Vitamins and Perinatal Outcomes Among HIV-Negative Women in Tanzania.

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    Prematurity and low birth weight are associated with high perinatal and infant mortality, especially in developing countries. Maternal micronutrient deficiencies may contribute to these adverse outcomes. In a double-blind trial in Dar es Salaam, Tanzania, we randomly assigned 8468 pregnant women (gestational age of fetus, 12 to 27 weeks) who were negative for human immunodeficiency virus infection to receive daily multivitamins (including multiples of the recommended dietary allowance) or placebo. All the women received prenatal supplemental iron and folic acid. The primary outcomes were low birth weight (<2500 g), prematurity, and fetal death. The incidence of low birth weight was 7.8% among the infants in the multivitamin group and 9.4% among those in the placebo group (relative risk, 0.82; 95% confidence interval [CI], 0.70 to 0.95; P=0.01). The mean difference in birth weight between the groups was modest (67 g, P<0.001). The rates of prematurity were 16.9% in the multivitamin group and 16.7% in the placebo group (relative risk, 1.01; 95% CI, 0.91 to 1.11; P=0.87), and the rates of fetal death were 4.3% and 5.0%, respectively (relative risk, 0.87; 95% CI, 0.72 to 1.05; P=0.15). Supplementation reduced both the risk of a birth size that was small for gestational age (<10th percentile; 10.7% in the multivitamin group vs. 13.6% in the placebo group; relative risk, 0.77; 95% CI, 0.68 to 0.87; P<0.001) and the risk of maternal anemia (hemoglobin level, <11 g per deciliter; relative risk, 0.88; 95% CI, 0.80 to 0.97; P=0.01), although the difference in the mean hemoglobin levels between the groups was small (0.2 g per deciliter, P<0.001). Multivitamin supplementation reduced the incidence of low birth weight and small-for-gestational-age births but had no significant effects on prematurity or fetal death. Multivitamins should be considered for all pregnant women in developing countries. (ClinicalTrials.gov number, NCT00197548 [ClinicalTrials.gov].)

    Biomarkers of Nutrition for Development (BOND)—Iron Review

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    This is the fifth in the series of reviews developed as part of the Biomarkers of Nutrition for Development (BOND) program. The BOND Iron Expert Panel (I-EP) reviewed the extant knowledge regarding iron biology, public health implications, and the relative usefulness of currently available biomarkers of iron status from deficiency to overload. Approaches to assessing intake, including bioavailability, are also covered. The report also covers technical and laboratory considerations for the use of available biomarkers of iron status, and concludes with a description of research priorities along with a brief discussion of new biomarkers with potential for use across the spectrum of activities related to the study of iron in human health. The I-EP concluded that current iron biomarkers are reliable for accurately assessing many aspects of iron nutrition. However, a clear distinction is made between the relative strengths of biomarkers to assess hematological consequences of iron deficiency versus other putative functional outcomes, particularly the relationship between maternal and fetal iron status during pregnancy, birth outcomes, and infant cognitive, motor and emotional development. The I-EP also highlighted the importance of considering the confounding effects of inflammation and infection on the interpretation of iron biomarker results, as well as the impact of life stage. Finally, alternative approaches to the evaluation of the risk for nutritional iron overload at the population level are presented, because the currently designated upper limits for the biomarker generally employed (serum ferritin) may not differentiate between true iron overload and the effects of subclinical inflammation

    Clustering di tracce di mobilità per l’identificazione di stili di guida

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    Traffic simulators are effective tools to support decisions in urban planning systems, to identify criticalities, to observe emerging behaviours in road networks and to configure road infrastructures, such as road side units and traffic lights. Clearly the more realistic the simulator the more precise the insight provided to decision makers. This paper provides a first step toward the design and calibration of traffic micro-simulator to produce realistic behaviour. The long term idea is to collect and analyse real traffic traces collecting vehicular information, to cluster them in groups representing similar driving behaviours and then to extract from these clusters relevant parameters to tune the microsimulator. In this paper we have run controlled experiments where traffic traces have been synthetized to obtain different driving styles, so that the effectiveness of the clustering algorithm could be checked on known labels. We describe the overall methodology and the results already achieved on the controlled experiment, showing the clusters obtained and reporting guidelines for future experiments

    Anemia in HIV

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    Driving behaviour clustering for realistic traffic micro-simulators

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    Traffic simulators are effective tools to support decisions in urban planning systems, to identify criticalities, to observe emerging behaviours in road networks and to configure road infrastructures, such as road side units and traffic lights. Clearly the more realistic the simulator the more precise the insight provided to decision makers. This paper provides a first step toward the design and calibration of traffic micro-simulator to produce realistic behaviour. The long term idea is to collect and analyse real traffic traces collecting vehicular information, to cluster them in groups representing similar driving behaviours and then to extract from these clusters relevant parameters to tune the microsimulator. In this paper we have run controlled experiments where traffic traces have been synthetized to obtain different driving styles, so that the effectiveness of the clustering algorithm could be checked on known labels. We describe the overall methodology and the results already achieved on the controlled experiment, showing the clusters obtained and reporting guidelines for future experiments

    Teaching residents to put patients first: creation and evaluation of a comprehensive curriculum in patient-centered communication

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    Abstract Background Patient-centered communication is essential for successful patient encounters and positive patient outcomes. Therefore, training residents how to communicate well is one of the key responsibilities of residency programs. However, many residents, especially international medical graduates, continue to struggle with communication barriers. Methods All residents and faculty from a small community teaching hospital participated in a three-year, multidimensional patient-centered communication curriculum including communication training with lectures, experiential learning, communication skills practice, and reflection in the areas of linguistics, physician-patient communication, cultural & linguistically appropriate care, and professionalism. We evaluated the program through a multipronged outcomes assessment, including self-assessment, scores on the Calgary-Cambridge Scale during Objective Structured Clinical Examination (OSCE), a survey to measure the hidden curriculum, English Communication Assessment Profile (E-CAP),, the Maslach Burnout-Inventory (MBI), and residents’ evaluation of faculty communication. Results Sixty-two residents and ten faculty members completed the three-year curriculum. We saw no significant changes in the MBI or hidden curriculum survey. Communication skills as measured by Calgary Cambridge Score, E-CAP, and resident communication improved significantly (average Calgary-Cambridge Scale scores from 70% at baseline to 78% at follow-up (p-value < 0.001), paired t-test score from 68% at baseline to 81% at follow-up (p-value < 0.004), average E-CAP score from 73 to 77% (p-value < 0.001)). Faculty communication and teaching as rated by residents also showed significant improvement in four out of six domains (learning climate (p < 0.001), patient-centered care (p = 0.01), evaluation (p = 0.03), and self-directed learning (p = 0.03)). Conclusion Implementing a multidimensional curriculum in patient-centered communication led to modest improvements in patient-centered communication, improved language skills, and improved communication skills among residents and faculty
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