Activation of effector immune cells promotes tumor stochastic extinction: A homotopy analysis approach

In this article we provide homotopy solutions of a cancer nonlinear model describing the dynamics of tumor cells in interaction with healthy and effector immune cells. We apply a semi-analytic technique for solving strongly nonlinear systems - the Step Homotopy Analysis Method (SHAM). This algorithm, based on a modification of the standard homotopy analysis method (HAM), allows to obtain a one-parameter family of explicit series solutions. By using the homotopy solutions, we first investigate the dynamical effect of the activation of the effector immune cells in the deterministic dynamics, showing that an increased activation makes the system to enter into chaotic dynamics via a period-doubling bifurcation scenario. Then, by adding demographic stochasticity into the homotopy solutions, we show, as a difference from the deterministic dynamics, that an increased activation of the immune cells facilitates cancer clearance involving tumor cells extinction and healthy cells persistence. Our results highlight the importance of therapies activating the effector immune cells at early stages of cancer progression

Phlorotannin Extracts from Fucales Characterized by HPLC-DAD-ESI-MSn: Approaches to Hyaluronidase Inhibitory Capacity and Antioxidant Properties

Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn . Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration, characteristic of the process.info:eu-repo/semantics/publishedVersio

Outer membrane vesicles from cold-adapted antarctic bacteria

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/63704Many Gram-negative, cold-adapted bacteria from the Antarctic environment produce large amounts of extracellular matter with potential biotechnological applications. Transmission electron microscopy (TEM) analysis after high-pressure freezing and freeze substitution (HPF-FS) showed that this extracellular matter is structurally complex, appearing around cells as a netlike mesh, and composed of an exopolymeric substance (EPS) containing large numbers of outer membrane vesicles (OMVs). Isolation, purification and protein profiling via 1D SDS-PAGE confirmed the outer membrane origin of these Antarctic bacteria OMVs. In an initial attempt to elucidate the role of OMVs in cold-adapted strains of Gram-negative bacteria, a proteomic analysis demonstrated that they were highly enriched in outer membrane proteins and periplasmic proteins associated with nutrient processing and transport, suggesting that the OMVs may be involved in nutrient sensing and bacterial survival. OMVs from Gram-negative bacteria are known to play a role in lateral DNA transfer, but the presence of DNA in these vesicles has remained difficult to explain. A structural study of Shewanella vesiculosa M7T using TEM and Cryo-TEM revealed that this Antarctic Gram-negative bacterium naturally releases conventional one-bilayer OMVs, together with a more complex type of OMV, previously undescribed, which on formation drags along inner membrane and cytoplasmic content and can therefore also entrap DNA

Thermal, mechanical, morphological and aesthetical properties of rotational molding PE/pine wood sawdust composites

This research addresses the importance of pine wood sawdust granulometry on the processing of medium-density polyethylene (MDPE)/wood composites by rotational molding and its effects on the morphological, mechanical and aesthetical properties of parts, aiming to contribute for the development of sustainable wood polymer composites (WPC) for rotational molding applications. Pine wood sawdust was sieved (1000 µm) and analyzed for its physical, morphological and thermal characteristics. Rotational molded parts were produced with matrix/wood ratios from 90/10 to 70/30 wt% considering different wood granulometries. As a natural material, wood changed its color during processing. Granulometries below 500 µm presented better sintering, homogeneity and less part defects. Furthermore, 300–500 µm favored the impact resistance (1316 N), as irregular brick-shaped wood was able to anchor to PE despite the weak interfacial adhesion observed. The increase of wood content from 10 to 30% reduced the impact properties by 40%, as a result of a highly porous structure formed, revealing sintering difficulties during processing. WPC parts of differentiated aesthetics and functionalities were achieved by rotational molding. A clear relationship between wood granulometry and WPC processing, structure and properties was identified.Financial support of the Project RoTMI-Rotomolding Technology and Materials Innovations (POCI-01-0247-FEDER-33095), cofinanced by the European Regional Development Fund (FEDER) through the Operational Program for Competitiveness and Internationalization (POCI) under the “Portugal 2020” framework; to the Portuguese Foundation for Science and Technology (FCT) through the National Funds References UIDB/05256/2020 and UIDP/05256/2020 provided to IPC

Mixing Community Capitals and Creative Placemaking for Craft-Beverage Tourism Development

Craft-beverage tourism (CBT) is a growing segment in the USA and an attractive strategy for sustainable development. Hyperlocal strategies are suitable for this segment because the perception of craft beverages being authentic cultural representations is appealing to tourists. This study aims to identify the resources that facilitate this development by combining two theoretical models; determine the role of hyperlocal strategies in CBT development; and test the resulting model in a different context. A mixed method approach in three phases will address these objectives. Data from the first phase revealed that creativity and meaning accelerated the growth of the community capitals needed for CBT, causing a spiraling up effect. The second phase will provide evidence of the impact of hyperlocal strategies in CBT experiences. Outcomes from the study’s third phase will further improve CBT development efforts and consolidate CBT knowledge, and hyperlocality’s role in different contexts and development stages

Scheduling Advertisement Delivery in Vehicular Networks

Vehicular users are emerging as a prime market for targeted advertisement, where advertisements (ads) are sent from network points of access to vehicles, and displayed to passengers only if they are relevant to them. In this study, we take the viewpoint of a broker managing the advertisement system, and getting paid every time a relevant ad is displayed to an interested user. The broker selects the ads to broadcast at each point of access so as to maximize its revenue. In this context, we observe that choosing the ads that best fit the users’ interest could actually hurt the broker’s revenue. In light of this conflict, we present Volfied, an algorithm allowing for conflict-free, near-optimal ad selection with very low computational complexity. Our performance evaluation, carried out through real-world vehicular traces, shows that Volfied increases the broker revenue by up to 70% with provably low computational complexity, compared to state-of-the-art alternatives.This work is supported by the European Commission through the H2020 5G-TRANSFORMER project (Project ID 761536).En prens

Adaptive behaviour and future time perspective: some evidence from education and health settings

O papel do futuro no comportamento actual dos indivíduos, em particular dos jovens, tem sido alvo de atenção ao longo do tempo, destacando-se aquele que tem vindo a ser um efeito consistente de associação entre, por um lado, a perspectivação e a construção de planos de futuro – expressados pelo conceito de perspectiva temporal de futuro (PTF) – e, por outro, a expressão de comportamentos adaptativos, que contribuem para uma maior adaptação ao meio. Dois dos contextos de estudo em que essa relação é mais abordada são os da educação e da saúde, este último especificamente ao nível da promoção de comportamentos saudáveis e da prevenção de riscos. Tendo em conta estes dois contextos, o presente trabalho pretende sistematizar e discutir um conjunto de dados, resultantes de vários estudos, e que se consideram relevantes para a evidenciação dessa relação

Cancer Models on Chip:Paving the Way to Large Scale Trial Applications

Cancer kills millions of individuals every year all over the world (Global Cancer Observatory). The physiological and biomechanical processes underlying the tumor are still poorly understood, hindering researchers from creating new, effective therapies. Inconsistent results of preclinical research, in vivo testing, and clinical trials decrease drug approval rates. Three-dimensional tumor-on-chip models integrate biomaterials, tissue engineering, fabrication of microarchitectures, and sensory and actuation systems in a single device, enabling reliable studies in fundamental oncology and pharmacology. This review includes a critical discussion about their ability to reproduce the tumor microenvironment, the advantages and drawbacks of existing tumor models and architectures, and major components and fabrication techniques. The focus is on current materials and micro/nanofabrication techniques used to manufacture reliable and reproducible microfluidic tumor-on-chip models for large-scale trial applications.</p