A não qualidade e o seu impacto no processo produtivo na Volkswagen Autoeuropa

Tese de mestrado integrado. Engenharia Industrial e Gestão. Universidade do Porto. Faculdade de Engenharia. 201

Phosphorous nanofertilizers for Precise application in rice cultivation as an adaptation to climate change

Rice is the staple food of more than half of the world’s population, which is still growing. The great dependence that agriculture, and rice specially, has on fertilizers alongside extreme events that result from climatic change creates an urge for adaptation. Fertilizers are expensive, finite and a potential environmental problem. Their precise application, by the use of slow-release nanofertilizers, thus avoiding losses and consequently reducing the pressure on water resources, is one step forward in this adaptation. It can reduce costs and protect the environment while ensuring food production. Phosphorous is very important for rice, since it is involved in its flowering and root development, and its low availability to the plants constitutes a serious problem. The delivery of phosphorous through the crop cycle in the form of slow-release phosphorus nanofertilizer (Pnf) instead of the conventional annual bulk application reduces the amount of nutrients applied and increases the absorption by the crop. Combining the fertilizing effect with the use of natural stimulant compounds such as chitosan can protect the crop from diseases and increase its resilience to stress. The use of Pnf reduces the pressure on water resources and avoids imbalances in soil nutrients, thus responding to climatic change challenges and abiotic stresses.info:eu-repo/semantics/publishedVersio

Enhanced Efficiency of PTB7 : PC 61

Ternary blend polymer solar cells combining two electron-donor polymers, poly[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b′]dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl] (PTB7) and poly[2,5-bis(3-dodecylthiophen-2-yl)thieno[3,2-b]thiophene] (pBTTT) and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), as electron-acceptor, were fabricated. The power conversion efficiency of the ternary cells was enhanced by 18%, with respect to the reference binary cells, for a blend composition with 25% (wt%) of pBTTT in the polymers content. The optimized device performance was related to the blend morphology, nonrevealing pBTTT aggregates, and improved charge extraction within the device

Graphene Oxide Thin Films with Drug Delivery Function

Funding Information: Funding: Funding was obtained through the Fundação para a Ciência e Tecnologia (FCT) through the projects iNOVA4Health, Translational Medicine program—UIDB/Multi/04462/2020; UIDB/50008/2020 and PTDC/CTM-REF/2679/2020.Graphene oxide has been used in different fields of nanomedicine as a manager of drug delivery due to its inherent physical and chemical properties that allow its use in thin films with biomedical applications. Several studies demonstrated its efficacy in the control of the amount and the timely delivery of drugs when it is incorporated in multilayer films. It has been demonstrated that oxide graphene layers are able to work as drug delivery or just to delay consecutive drug dosage, allowing the operation of time-controlled systems. This review presents the latest research developments of biomedical applications using graphene oxide as the main component of a drug delivery system, with focus on the production and characterization of films, in vitro and in vivo assays, main applications of graphene oxide biomedical devices, and its biocompatibility properties.publishersversionpublishe

Cell-to-cell transmission of HIV-1 and HIV-2 from infected macrophages and dendritic cells to CD4+ T lymphocytes

Macrophages (Mø) and dendritic cells (DCs) are key players in human immunodeficiency virus (HIV) infection and pathogenesis. They are essential for the spread of HIV to CD4+ T lymphocytes (TCD4+) during acute infection. In addition, they constitute a persistently infected reservoir in which viral production is maintained for long periods of time during chronic infection. Defining how HIV interacts with these cells remains a critical area of research to elucidate the pathogenic mechanisms of acute spread and sustained chronic infection and transmission. To address this issue, we analyzed a panel of phenotypically distinct HIV-1 and HIV-2 primary isolates for the efficiency with which they are transferred from infected DCs or Mø to TCD4+. Our results show that infected Mø and DCs spread the virus to TCD4+ via cell-free viral particles in addition to other alternative pathways. We demonstrate that the production of infectious viral particles is induced by the co-culture of different cell populations, indicating that the contribution of cell signaling driven by cell-to-cell contact is a trigger for viral replication. The results obtained do not correlate with the phenotypic characteristics of the HIV isolates, namely their co-receptor usage, nor do we find significant differences between HIV-1 and HIV-2 in terms of cis- or trans-infection. The data presented here may help to further elucidate the cell-to-cell spread of HIV and its importance in HIV pathogenesis. Ultimately, this knowledge is critical for new therapeutic and vaccine approaches.info:eu-repo/semantics/publishedVersio

Editorial

Editorial do primeiro número da Revista POLIGE

Graphene oxide layer-by-layer films for sensors and devices

Funding Information: Funding: The research leading to these results has received funding from the European Community’s Seventh Framework Programme (FP7/2007–2013) CALIPSO under grant agreement number 312284 and from the Portuguese funding agency FCT—Fundação para a Ciência e a Tecnologia—within projects UID/EEA/50014/2019, UID/FIS/00068/2019, PTDC/FIS-NAN/0909/2014, UID/FIS/00068/2019, the Bilateral Project entitled “Deteção de Estrogénio-um Contaminante Emergente em Corpos Hídricos” within the scope of “Cooperação Transnacional_FCT (Portugal)-CAPES (Brazil) 2018”.Layer-by-layer films of poly (allylamine hydrochloride) (PAH) and graphene oxide (GO) were characterized, looking at growth with the number of bilayers, morphology, and electrical properties. The PAH/GO films revealed a linear increase in absorbance with the increase in the number of deposited bilayers, allowing the determination that 10.7 ± 0.1 mg m−2 of GO is adsorbed per unit of area of each bilayer. GO absorption bands at 146, 210, 247 and 299 nm, assigned to π-π* and n-π* transitions in the aromatic ring (phenol) and of the carboxylic group, respectively, were characterized by vacuum ultraviolet spectroscopy. The morphological characterization of these films demonstrated that they are not completely uniform, with a bilayer thickness of 10.5 ± 0.7 nm. This study also revealed that the films are composed of GO and/or PAH/GO fibers and that GO is completely adsorbed on top of PAH. The electrical properties of the films reveal that PAH/GO films present a semiconductor behavior. In addition, a slight decrease in conduction was observed when films were prepared in the presence of visible light, likely due to the presence of oxygen and moisture that contributes to the damage of GO molecules.publishersversionpublishe

Pregnancy in times of COVID-19 pandemic:quality and safety of health care during pregnancy care

The current COVID-19 pandemic situation makes the whole health care delivery environment more demanding and uncertain, creating in organizations the need to redefine strategies to meet new challenges and people's needs. In the field of maternal health, specific circuits and procedures have been ensured for all pregnant women in order to prevent or reduce the risk of infection by SARS-CoV-2. This study aims to determine the level of quality of health care during pregnancy and to assess the satisfaction of pregnant women with regard to maternal health care provided in the current context of the COVID-19 pandemic. This is a quantitative, observational, analytical study, whose sample includes pregnant women aged 36 weeks and over. The information was collected between November and December 2020, through the application of a survey encompassing the Quality of Parental Care Questionnaire (Sword, Heaman and the QPCQ Research Team, 2013 translated and validated for the Portuguese population by Rodrigues, 2017), clinical, socio-demographic and access and security variables related to the current COVID-19 pandemic. The results obtained project a positive relationship between the level of satisfaction of pregnant women and the perception of the level of quality of prenatal care in all dimensions of the instrument. In the specificities related to access and safety in the current COVID-19 pandemic, teleconsultation presents itself as an important tool in prenatal education and accessibility to health care during pregnancy care. A model of pregnancy care that encompasses telehealth becomes indispensable to meet the needs created by the COVID-19 pandemic, improving flexibility, access and proximity to maternal health care.info:eu-repo/semantics/publishedVersio

The use of nanofertilizers to increase precision in rice production

Rice cultivation (Oryza sativa L.) has a widespread use of fertilizers and pesticides since it is necessary to produce larger quantities and also prevent the effect of pests, diseases and weeds, in order to fulfil the food demands of a growing world population. For the use of phosphorus, the limit set by Bertolami & Francisco (2020), at the Planetary Boundaries, has already been exceeded, causing marked disturbances in the earth system, meaning that its delivery, although indispensable, must be carried out precisely and in forms that can be easily assimilated by crops. The scarcity of phosphorus and the consequent increase in its price in recent years also impose the urgency of new forms of application. Nanofertilizers can provide a precise and more sustainable way of application, as the amount of raw material is reduced. Likewise, the pressure on aquatic ecosystems is reduced, since rice is grown in flooded beds and therefore losses to water bodies have to be reduced. The aim of this work is to develop phosphorous nanofertilizer pellets, which use slow release technology to ensure the precise and efficient application of phosphorus to rice crops along the cycle, and to verify their possible effect as a biostimulant. The use of suitable and sustainable supports for nanofertilizers is extremely important as the main challenge for their use is the amount of support required to successfully deliver the active substance (Ekebafe et al., 2011). The proposed pellets will consist of poly-beta-amino-esters (PBAE), graphene oxide (GO), chitosan, poly lactic-co-glycolic acid (PLGA) and the active substance. Development of the pellets will comprise component integration and design, followed by kinetic tests to assess its stability under different conditions. Ecotoxicology tests, at different trophic levels, will be performed to ensure that there are no ecotoxicity effects from the use of any component and/or combination of components. Finally, when all the preparatory tests are concluded, feedback will be given to the development stage and improvements will be made to optimize the pellets. When the optimization process is complete, the pellets will be tested in pilot rice assays where conventional fertilizer will be used as control. If the pellets prove to be effective and without any harmful effect, its use can be spread to other fertilizer and other crops towards a more sustainable production.info:eu-repo/semantics/publishedVersio

Bottom-Up Self-Assembled Supramolecular Structures Built by STM at the Solid/Liquid Interface

One of the lines of research on organic devices is focused on their miniaturization to obtain denser and faster electronic circuits. The challenge is to build devices adding atom by atom or molecule by molecule until the desired structures are achieved. To do this job, techniques able to see and manipulate matter at this scale are needed. Scanning tunneling microscopy (STM) has been the selected technique by scientists to develop smart and functional unimolecular devices. This review article compiles the latest developments in this field giving examples of supramolecular systems monitored and fabricated at the molecular scale by bottom-up approaches using STM at the solid/liquid interface