Design and testing of 3D printed cross compound parabolic concentrators for LCPV system

Concentrating Photovoltaic (CPV) Systems has the potential to increase the power output and reduce the cost of PV systems. This work demonstrates a successful attempt to fabricate high performance Cross Compound Parabolic Concentrator (CCPC) using 3D printing. The performance of the 3D printed CCPCs was characterized using a testing setup that consists of a monocrystalline silicon solar cell (10mm × 10mm) mounted on a cooling/rotation stage. Five CCPCs of varied concentration ratio (2.9×, 4.0×, 6.0×, 7.8× and 9.0×) were fabricated and their performance were evaluated. The results show that the optical efficiency of these 3D printed CCPC ranges from 82% to 89%, representing the highest values reported to date. In addition, the angular responses of the concentrators were also evaluated

Direct ink writing advances in multi-material structures for a sustainable future

Novel manufacturing techniques such as additive manufacturing (AM, also referred to as 3D printing) will play a critical role in building a sustainable future. AM will reduce waste, energy consumption and production time by eliminating the need to assemble components. It will also enable the mass customization of complex devices. To reach their full potential, additive manufacturing technologies should be able to combine different materials in a single processing step. Although the development of multi-material printing is in its infancy, it could have a massive impact in fields as diverse as energy storage and generation, electronic devices, healthcare or structural composites to name a few. Here we provide a critical perspective on the advances and potential of multi-material printing using direct extrusion-based printing, also known as direct ink writing (DIW) or robocasting. We will show examples of devices and structures combining a wide range of materials from ceramics to metals, polymers and carbon with particular focus on three promising applications: energy storage, lightweight composites and sensors. The goals are to assess the progress made so far, to point out specific challenges and areas for further development and to provide guidelines to those interested in multi-material DIW

A facile way to produce epoxy nanocomposites having excellent thermal conductivity with low contents of reduced graphene oxide

A well-dispersed phase of exfoliated graphene oxide (GO) nanosheets was initially prepared in water. This was concentrated by centrifugation and was mixed with a liquid epoxy resin. The remaining water was removed by evaporation, leaving a GO dispersion in epoxy resin. A stoichiometric amount of an anhydride curing agent was added to this epoxy-resin mixture containing the GO nanosheets, which was then cured at 90 C for 1 h followed by 160 C for 2 h. A second thermal treatment step of 200 C for 30 min was then undertaken to reduce further the GO in situ in the epoxy nanocomposite. An examination of the morphology of such nanocomposites containing reduced graphene oxide (rGO) revealed that a very good dispersion of rGO was achieved throughout the epoxy polymer. Various thermal and mechanical properties of the epoxy nanocomposites were measured, and the most noteworthy finding was a remarkable increase in the thermal conductivity when relatively very low contents of rGO were present. For example, a value of 0.25 W/mK was measured at 30 C for the nanocomposite with merely 0.06 weight percentage (wt%) of rGO present, which represents an increase of *40% compared with that of the unmodified epoxy polymer. This value represents one of the largest increases in the thermal conductivity per wt% of added rGO yet reported. These observations have been attributed to the excellent dispersion of rGO achieved in these nanocomposites made via this facile production method. The present results show that it is now possible to tune the properties of an epoxy polymer with a simple and viable method of GO addition. A

Enabling water-based processing of graphene/alumina composites using an infiltration approach with amphiphilic triblock copolymers

Enabling the direct infiltration of freeze-cast graphene structures with water-based ceramic suspensions, otherwise prevented by graphene’s intrinsic hydrophobic behaviour, can lead to the production of hierarchical graphene/ceramic composites in a cost-effective and replicable manner. In this study, the addition of a triblock copolymer (PF127) in the formulation of water-based alumina slurries was used to allow the integration with reduced graphene oxide (rGO) scaffolds combining freeze-casting, wet chemistry processing and Spark Plasma Sintering. Wettability and infiltration tests were performed to optimise the composition of the ceramic suspension, leading to the preservation of alignment in embedded rGO scaffolds and maintaining channel widths of 5–15▒μm upon sintering at 1500∘ C

Formation of polarised, functional artificial cells from compartmentalised droplet networks and nanomaterials, using one-step, dual-material 3D-printed microfluidics

The bottom‐up construction of synthetic cells with user‐defined chemical organization holds considerable promise in the creation of bioinspired materials. Complex emulsions, droplet networks, and nested vesicles all represent platforms for the engineering of segregated chemistries with controlled communication, analogous to biological cells. Microfluidic manufacture of such droplet‐based materials typically results in radial or axisymmetric structures. In contrast, biological cells frequently display chemical polarity or gradients, which enable the determination of directionality, and inform higher‐order interactions. Here, a dual‐material, 3D‐printing methodology to produce microfluidic architectures that enable the construction of functional, asymmetric, hierarchical, emulsion‐based artificial cellular chassis is developed. These materials incorporate droplet networks, lipid membranes, and nanoparticle components. Microfluidic 3D‐channel arrangements enable symmetry‐breaking and the spatial patterning of droplet hierarchies. This approach can produce internal gradients and hemispherically patterned, multilayered shells alongside chemical compartmentalization. Such organization enables incorporation of organic and inorganic components, including lipid bilayers, within the same entity. In this way, functional polarization, that imparts individual and collective directionality on the resulting artificial cells, is demonstrated. This approach enables exploitation of polarity and asymmetry, in conjunction with compartmentalized and networked chemistry, in single and higher‐order organized structures, thereby increasing the palette of functionality in artificial cellular materials

Propuesta de mejora del Sistema Interno de Garantía de Calidad de la Facultad de Medicina

La garantía de calidad en el ámbito universitario puede considerarse como la atención sistemática, estructurada y continua a las titulaciones ofertadas. La garantía de calidad se compromete a poner en marcha los medios que aseguren y demuestren la calidad de los programas formativos que se desarrollan en cada una de las titulaciones ofrecidas por la Universidad y así cumplir con la obligación que tiene con la sociedad. El presente proyecto nace como fruto de la responsabilidad adquirida para el cumplimiento de las funciones encomendadas y, con el objetivo de seguir adoptando una estrategia de mejora continua de la calidad de la docencia y satisfacción de los colectivos implicados en el proceso de enseñanza-aprendizaje (Profesorado, Estudiantes y PAS)

Factor von Willebrand como intermediario entre la hemostasia y la angiogénesis de origen tumoral

Cancer patients often show an imbalance condition between coagulation system and fibrinolysis which causes a prothrombotic state. Different molecular factors like von Willebrand factor (vWf), presenting higher plasmatic rates in these patients, play an important role in this situation. During active angiogenesis taking place in tumor growth, the vascular endothelial growth factor (VEGF) and the fibroblast growth factor (FGF-2) contribute to the proliferation and differentiation of endothelial tissue, the main vWf producer, promoting increased rates of vWf in the serum of neoplastic patients. Recently vWf's contribution to tumor cells and platelet adhesion has been described. In this process, the discovery of platelet, endothelial and tumor cell membrane integrins and their implication in cellular adhesion has represented a major step in demonstrating how blood clotting and platelet aggregation are mediated by tumor cell and platelet linkage. Migration properties acquired by tumor cells as a result of this binding have been also pointed out. Clinical trials show higher rates of plasmatic vWf in cancer patients the more advanced clinical and radiological stage they present (metastasic versus localized). Moreover, higher pre-surgical serum vWf rates in patients can be used to predict poorer survival after resection surgery. vWf high molecular weight multimers have been also related to a cleavage protease deficiency in the serum of the oncologic population. The promising results of antiaggregation/anticoagulation therapies in these patients permit us to envisage new therapeutic target

A Mobile Health Intervention for Patients With Depressive Symptoms: Protocol for an Economic Evaluation Alongside Two Randomized Trials in Brazil and Peru

BACKGROUND: Mobile health interventions provide significant strategies for improving access to health services, offering a potential solution to reduce the mental health treatment gap. Economic evaluation of this intervention is needed to help inform local mental health policy and program development. OBJECTIVE: This paper presents the protocol for an economic evaluation conducted alongside 2 randomized controlled trials (RCTs) to evaluate the cost-effectiveness of a psychological intervention delivered through a technological platform (CONEMO) to treat depressive symptoms in people with diabetes, hypertension, or both. METHODS: The economic evaluation uses a within-trial analysis to evaluate the incremental costs and health outcomes of CONEMO plus enhanced usual care in comparison with enhanced usual care from public health care system and societal perspectives. Participants are patients of the public health care services for hypertension, diabetes, or both conditions in São Paulo, Brazil (n=880) and Lima, Peru (n=432). Clinical effectiveness will be measured by reduction in depressive symptoms and gains in health-related quality of life. We will conduct cost-effectiveness and cost-utility analyses, providing estimates of the cost per at least 50% reduction in 9-item Patient Health Questionnaire scores, and cost per quality-adjusted life year gained. The measurement of clinical effectiveness and resource use will take place over baseline, 3-month follow-up, and 6-month follow-up in the intervention and control groups. We will use a mixed costing methodology (ie, a combination of top-down and bottom-up approaches) considering 4 cost categories: intervention (CONEMO related) costs, health care costs, patient and family costs, and productivity costs. We will collect unit costs from the RCTs and national administrative databases. The multinational economic evaluations will be fully split analyses with a multicountry costing approach. We will calculate incremental cost-effectiveness ratios and present 95% CIs from nonparametric bootstrapping (1000 replicates). We will perform deterministic and probabilistic sensitivity analyses. Finally, we will present cost-effectiveness acceptability curves to compare a range of possible cost-effectiveness thresholds. RESULTS: The economic evaluation project had its project charter in June 2018 and is expected to be completed in September 2021. The final results will be available in the second half of 2021. CONCLUSIONS: We expect to assess whether CONEMO plus enhanced usual care is a cost-effective strategy to improve depressive symptoms in this population compared with enhanced usual care. This study will contribute to the evidence base for health managers and policy makers in allocating additional resources for mental health initiatives. It also will provide a basis for further research on how this emerging technology and enhanced usual care can improve mental health and well-being in low- and middle-income countries. TRIAL REGISTRATION: ClinicalTrials.gov NCT12345678 (Brazil) and NCT03026426 (Peru); https://clinicaltrials.gov/ct2/show/NCT02846662 and https://clinicaltrials.gov/ct2/show/NCT03026426. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/26164

An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers

Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects.Peer reviewe

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio