Coupling of plasmonic nanoparticles on a semiconductor substrate via a modified discrete dipole approximation method.

Understanding the plasmonic coupling between a set of metallic nanoparticles (NPs) in a 2D array, and how a substrate affects such coupling, is fundamental for the development of optimized optoelectronic structures. Here, a simple semi-analytical procedure based on discrete dipole approximation (DDA) is reported to simulate the far-field and near-field properties of arrays of NPs, considering the coupling between particles, and the effect of the presence of a semiconductor substrate based on the image dipole approach. The method is validated for Ag NP dimers and single Ag NPs on a gallium nitride (GaN) substrate, a semiconductor widely used in optical devices, by comparison with the results obtained by the finite element method (FEM), indicating a good agreement in the weak coupling regime. Next, the method is applied to square and random arrays of Ag NPs on a GaN substrate. The increase in the surface density of NPs on a GaN substrate mainly results in a redshift of the dipolar resonance frequency and an increase in the near-field enhancement. This model, based on a single dipole approach, grants very low computational times, representing an advantage to predict the optical properties of large NP arrays on a semiconductor substrate for different applications.

Effects of nanoplastics on zebrafish embryo-larval stages: A case study with polystyrene (PS) and polymethylmethacrylate (PMMA) particles.

Plastic production has been rising consistently in the last 30 years and with it, the presence of plastic particles in the environment. A decrease in size often increases the bioavailability and reactivity of the particles. In this study the impact of polystyrene (PS; 22 nm) and polymethylmethacrylate (PMMA; 32 nm) nanoparticles on zebrafish embryo-larval stages was assessed by studying mortality, hatching, morphological features, and biochemical endpoints (associated with neurotransmission, antioxidant status and oxidative damage, and energy metabolism) after 96 h exposure, and swimming behavior after 120 h exposure. Organisms exposed to PMMA nanoparticles exhibited higher mortality and pericardial edema than those exposed to PS nanoparticles but displayed less effects on swimming behavior. Biochemical endpoints were altered to a higher degree in organisms exposed to PS nanoparticles (acetylcholinesterase, glutathione S-transferase and catalase activities) but higher peroxidative damage was found after exposure to lower concentrations of PMMA nanoparticles. Both types of nanoparticles affected energy metabolism with higher levels of glycogen found in animals exposed to PS nanoparticles. The use of integrated biomarker response index confirmed that PS nanoparticles had a higher impact on biochemical endpoints of zebrafish.

Flexural strength of 3Y-TZP bioceramics obtained by direct write assembly as function of residual connected-porosity.

OBJECTIVES: The present work reports the effect of the extrusion nozzles' size and consequent residual porosity on the flexural strength of 3Y-TZP bioceramics fabricated by direct write assembly technology. METHODS: A printable ink containing a volume fraction of 45% of 3Y-TZP (ZrO2 stabilized with 3 mol% Y2O3) submicron powder, carboxymethyl cellulose and polyethyleneimine as additives was fine-tuned by rheological measurements. Different nozzle diameters (0.41 mm, 0.33 mm, and 0.25 mm) were used to print 3D specimens with proper dimensions for structural and mechanical characterization after sintering, namely relative density, linear shrinkage, and three-point flexural strength. Bulk surface sample and exposed fractured surfaces after flexural strength tests were analyzed by X-ray diffraction, Rietveld refinement and scanning electronic microscopy. Strength reliability and failure probability of the three sample groups were analyzed by Weibull statistics. RESULTS: The sintered samples exhibited relative densities in the range of 78% (nozzle Ø 0.41 = mm) and 82% (nozzle Ø 0.25 = mm), i.e., a slight increase in the residual interfilamentous porosity is observed, as the extrusion tip diameter increases, while linear shrinkage is statistically similar (≈25%). Likewise, a progressive reduction of flexural strength and Weibull modulus as nozzle diameter increases was noticeable, being respectively σf = 337,5 ± 49 MPa and m = 6.6 for the smallest nozzle diameter (Ø = 0.25 mm) and σf = 261.4 ± 79 MPa and m = 3.2 for the biggest one (Ø = 0.41 mm). Unlike nozzle diameter, the material is constituted by 79-81 wt% tetragonal t-ZrO2 and 19-21 wt% cubic c-ZrO2 with equiaxed grain sizes between 0.3 and 0.6 µm. CONCLUSION: X-ray diffraction analyses on the fracture surface of flexural test samples suggests that the toughening mechanism by tetragonal→ monoclinic phase transformation is the main responsible for the mechanical strength of this structural ceramic. Additionally, the reduction of flexural strength for samples printed with extrusion nozzle of 0.41 mm could be explained by the surface roughness of the bending surfaces, as well as the lower effective resistance to crack-propagation arising from the higher size of residual pores on the fracture surface.

Photodegradation of Aquaculture Antibiotics Using Carbon Dots-TiO2 Nanocomposites.

In this work, carbon dots (CD) were synthesized and coupled to titanium dioxide (TiO2) to improve the photodegradation of antibiotics in aquaculture effluents under solar irradiation. Oxolinic acid (OXA) and sulfadiazine (SDZ), which are widely used in aquaculture, were used as target antibiotics. To prepare nanocomposites of CD containing TiO2, two modes were used: in-situ (CD@TiO2) and ex-situ (CD/TiO2). For CD synthesis, citric acid and glycerol were used, while for TiO2 synthesis, titanium butoxide was the precursor. In ultrapure water (UW), CD@TiO2 and CD/TiO2 showed the largest photocatalytic effect for SDZ and OXA, respectively. Compared with their absence, the presence of CD@TiO2 increased the photodegradation of SDZ from 23 to 97% (after 4 h irradiation), whereas CD/TiO2 increased the OXA photodegradation from 22 to 59% (after 1 h irradiation). Meanwhile, in synthetic sea salts (SSS, 30‱, simulating marine aquaculture effluents), CD@TiO2 allowed for the reduction of SDZ's half-life time (t1/2) from 14.5 ± 0.7 h (in absence of photocatalyst) to 0.38 ± 0.04 h. Concerning OXA in SSS, the t1/2 remained the same either in the absence of a photocatalyst or in the presence of CD/TiO2 (3.5 ± 0.3 h and 3.9 ± 0.4 h, respectively). Overall, this study provided novel perspectives on the use of eco-friendly CD-TiO2 nanocomposites for the removal of antibiotics from aquaculture effluents using solar radiation.

Management of post-septal complications of acute rhinosinusitis in children: A 14-year experience in a tertiary hospital.

INTRODUCTION: Acute rhinosinusitis accounts for most of the cases of orbital infections and is the most common cause of periorbital oedema in children. Up to 10% of patients with orbital complications of acute rhinosinusitis may experience vision loss and other complications such as meningitis, intracranial abscess or even death. Therefore, these patients require prompt diagnosis and proper treatment. OBJECTIVES: This study aims to report the clinical presentation and management of post-septal orbital complications of acute rhinosinusitis in the paediatric population. MATERIALS AND METHODS: A retrospective medical chart review of all children aged under 18 years old who were diagnosed with post-septal orbital complications of acute rhinosinusitis at a tertiary academic hospital, between 01/2007 and 12/2020. Patients were grouped according to the Chandler Classification (groups 2-5). RESULTS: Fifty-five children (mean age of 6.91 ± 4.61 years) fulfilled the entry criteria for post-septal orbital complications of acute rhinosinusitis, based on clinical evaluation by an otorhinolaryngologist and CT-scan findings. Forty (72.72%) patients were also evaluated by an ophthalmologist. Most patients were male (76.36%). Twenty-four patients had post-septal cellulitis (43.63%), 21 patients had a subperiosteal abscess (38.18%) and 10 patients had an orbital abscess (18.18%). Eyelid swelling was the most frequent sign, followed by fever. Microbiology varied considerably and gram-positive agents were clearly predominant. Eighteen (32.73%) patients had been treated with oral antibiotics prior to hospital admission, exhibiting a significantly higher risk of recurrence of orbital infection (p = 0.020). Ethmoid and maxillary sinuses were the most involved paranasal sinuses (90.91%). Thirty-three patients (60%) were successfully treated medically, and 22 patients (40%) required surgical drainage. Seven patients (12.73%) developed further complications and six recovered without sequelae. The mean length of hospital stay was 8.0 ± 5.0 days and recurrence of orbital infection occurred in six patients (10.91%). The absolute neutrophil blood count was significantly different amongst Chandler groups (p = 0.021), with higher counts in patients with subperiosteal abscess. The duration of hospitalization was significantly higher in patients submitted to surgery (p < 0.001). CONCLUSION: Post-septal orbital complications of acute rhinosinusitis are infrequent but dangerous events in the paediatric population. Close collaboration with Ophtalmology is paramount, as the child's vision is at risk. Eyelid swelling and proptosis are early signs. CT-scan imaging plays an invaluable role in the diagnosis and decision-making. Predictive indicators for surgery were not found. However, emergency endoscopic nasal surgery with abscess drainage should be considered whenever vision is at risk, if there is no improvement after aggressive medical treatment, and in cases of intracranial complications.

The quality of health governance in Portugal: an evaluation of the Troika's intervention period. / Qualidade da governança da saúde em Portugal: uma avaliação ao período de intervenção da Troika.

This study aims to evaluate the quality of the Portuguese Government's action in the health sector during Troika's intervention period (2011-2015), taking as criterion the concern with the application of Good Governance principles, in terms of degree and diversity. The intention is to understand the extent to which the public action promoted by the Ministry of Health has developed seeking to contribute to the strengthening of Good Governance practices. Fifty measures of the Ministry of Health, distributed by nine intervention areas, were analyzed, based on documental analysis, supported on the law and on other official documents. The principles of Good Governance that demonstrate a more transversal concern are clearly that of "transparency" and of "effectiveness/efficiency", present in eight of the nine intervention areas. The concern with "orientation to consensus" is essentially present in the measures classified as Agreements, "independence" in the Ethics area, the "strengthening of the rule of Law" in the Control area and "equity/inclusion" in the area of the Citizen in the Centre of the NHS.

Este estudo tem como objetivo avaliar a qualidade da ação do Governo Português no sector da saúde, no período de intervenção da Troika (2011-2015), tomando como critério a preocupação com a aplicação dos princípios de Boa Governança, em termos de grau e diversidade. Pretende-se perceber em que medida a ação pública promovida pelo Ministério da Saúde se desenvolveu procurando contribuir para o fortalecimento das práticas de Boa Governança. Com base em análise documental, suportada nos diplomas legais e em outros documentos oficiais, foram analisadas 50 medidas de ação do Ministério da Saúde, que se distribuem por nove áreas de intervenção. Os princípios de Boa Governança que representam uma preocupação mais transversal são claramente o da "transparência" e o da "eficácia/eficiência", presentes em oito das nove áreas de intervenção. A preocupação com a "orientação para consensos" está essencialmente presente nas medidas tipificadas como Acordos, a "independência" na área Ética, o "reforço do Estado de direito" na área Controlo e a "equidade/inclusão" na área Cidadão no Centro do SNS.

Biochar-TiO2 magnetic nanocomposites for photocatalytic solar-driven removal of antibiotics from aquaculture effluents.

Contamination of surrounding waters with antibiotics by aquaculture effluents can be problematic due to the possible increase of bacterial resistance, making it crucial the efficient treatment of those effluents before their release into the environment. In this work, the application of waste-based magnetic biochar/titanium dioxide (BC/TiO2) composite materials on the photodegradation of two antibiotics widely used in aquaculture (sulfadiazine (SDZ) and oxolinic acid (OXA)) was assessed. Four materials were synthesized: BCMag (magnetized BC), BCMag_TiO2 (BCMag functionalized with TiO2), BC_TiO2_MagIn and BC_TiO2_MagEx (BC functionalized with TiO2 and afterwards magnetized by in-situ and ex-situ approaches, respectively). SDZ half-life time (t1/2) noticeably decreased 3.9 and 3.4 times in presence of BCMag_TiO2 and BC_TiO2_MagEx, respectively. In the case of OXA, even though differences were not so substantial, the produced photocatalysts also allowed for a decrease in t1/2 (2.6 and 1.7 times, in presence of BCMag_TiO2 and BC_TiO2_MagEx, respectively). Overall, the here synthesized BC/TiO2 magnetic nanocomposites through a circular economy process are promising photocatalysts for a sustainable solar-driven removal of antibiotics from aquaculture effluents.

Qualidade da governança da saúde em Portugal: uma avaliação ao período de intervenção da Troika / The quality of health governance in Portugal: an evaluation of the Troika's intervention period

Resumo Este estudo tem como objetivo avaliar a qualidade da ação do Governo Português no sector da saúde, no período de intervenção da Troika (2011-2015), tomando como critério a preocupação com a aplicação dos princípios de Boa Governança, em termos de grau e diversidade. Pretende-se perceber em que medida a ação pública promovida pelo Ministério da Saúde se desenvolveu procurando contribuir para o fortalecimento das práticas de Boa Governança. Com base em análise documental, suportada nos diplomas legais e em outros documentos oficiais, foram analisadas 50 medidas de ação do Ministério da Saúde, que se distribuem por nove áreas de intervenção. Os princípios de Boa Governança que representam uma preocupação mais transversal são claramente o da "transparência" e o da "eficácia/eficiência", presentes em oito das nove áreas de intervenção. A preocupação com a "orientação para consensos" está essencialmente presente nas medidas tipificadas como Acordos, a "independência" na área Ética, o "reforço do Estado de direito" na área Controlo e a "equidade/inclusão" na área Cidadão no Centro do SNS.

Abstract This study aims to evaluate the quality of the Portuguese Government's action in the health sector during Troika's intervention period (2011-2015), taking as criterion the concern with the application of Good Governance principles, in terms of degree and diversity. The intention is to understand the extent to which the public action promoted by the Ministry of Health has developed seeking to contribute to the strengthening of Good Governance practices. Fifty measures of the Ministry of Health, distributed by nine intervention areas, were analyzed, based on documental analysis, supported on the law and on other official documents. The principles of Good Governance that demonstrate a more transversal concern are clearly that of "transparency" and of "effectiveness/efficiency", present in eight of the nine intervention areas. The concern with "orientation to consensus" is essentially present in the measures classified as Agreements, "independence" in the Ethics area, the "strengthening of the rule of Law" in the Control area and "equity/inclusion" in the area of the Citizen in the Centre of the NHS.

COVID-19 in a Patient Newly Diagnosed with AIDS: Asymptomatic Disease.

The COVID-19 pandemic has posed new challenges for the scientific community. The behaviour of the virus and outcomes in people living with HIV have not yet been properly studied. We report the case of a 34-year-old man with newly diagnosed HIV infection stage 4 and asymptomatic SARS-CoV-2 infection. Although immunocompromised patients are classified as being at high risk of developing severe COVID-19, HIV-related immunosuppression may have a protective role. LEARNING POINTS: It is important to remember that not every respiratory infection during this pandemic is due to SARS-CoV-2.We need more studies to elucidate the behaviour of COVID-19 in people living with HIV.There is still doubt about the best time for antiretroviral therapy (ART) initiation in this context.

Reduced Global Genetic Differentiation of Exploited Marine Fish Species.

Knowledge on genetic structure is key to understand species connectivity patterns and to define the spatiotemporal scales over which conservation management plans should be designed and implemented. The distribution of genetic diversity (within and among populations) greatly influences species ability to cope and adapt to environmental changes, ultimately determining their long-term resilience to ecological disturbances. Yet, the drivers shaping connectivity and structure in marine fish populations remain elusive, as are the effects of fishing activities on genetic subdivision. To investigate these questions, we conducted a meta-analysis and compiled genetic differentiation data (FST/ΦST estimates) for more than 170 fish species from over 200 published studies globally distributed. We modeled the effects of multiple life-history traits, distance metrics, and methodological factors on observed population differentiation indices and specifically tested whether any signal arising from different exposure to fishing exploitation could be detected. Although the myriad of variables shaping genetic structure makes it challenging to isolate the influence of single drivers, results showed a significant correlation between commercial importance and genetic structure, with widespread lower population differentiation in commercially exploited species. Moreover, models indicate that variables commonly used as proxy for connectivity, such as larval pelagic duration, might be insufficient, and suggest that deep-sea species may disperse further. Overall, these results contribute to the growing body of knowledge on marine genetic connectivity and suggest a potential effect of commercial fisheries on the homogenization of genetic diversity, highlighting the need for additional research focused on dispersal ecology to ensure long-term sustainability of exploited marine species.

Highly Electroconductive Nanopapers Based on Nanocellulose and Copper Nanowires: A New Generation of Flexible and Sustainable Electrical Materials.

Nowadays, the development of sustainable high-performance functional nanomaterials is in the spotlight. In this work, we report the preparation of a new generation of flexible and high electroconductive nanopapers based on nanofibrillated cellulose (NFC) and copper nanowires (CuNWs). Homogeneous red brick color nanopapers (thickness 30.2-36.4 µm) were obtained by mixing different amounts of NFC aqueous suspensions and CuNWs (1, 5, 10, 20, and 50 wt %), followed by vacuum filtration and drying. scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis confirmed the incorporation of the different amounts of CuNWs, and their uniform and random distribution. All of the nanomaterials displayed good mechanical properties, viz., Young's modulus = 2.62-4.72 GPa, tensile strength = 30.2-70.6 MPa, and elongation at break = 2.3-4.1% for the nanopapers with 50 and 1 wt % of CuNWs mass fraction, respectively. The electrical conductivity of these materials strongly depends on the CuNW content, attaining a value of 5.43 × 104 S·m-1 for the nanopaper with a higher mass fraction. This is one of the highest values reported so far for nanocellulose-based conductive materials. Therefore, these nanopapers can be seen as an excellent inexpensive and green alternative to the current electroconductive materials for applications in electronic devices, energy storage, or sensors.

Biocompatible chitosan-based composites with properties suitable for hyperthermia therapy.

Sustainably made, flexible and biocompatible composites, having environmentally friendly compositions and multifunctional capabilities, are promising materials for several emerging biomedical applications. Here, the development of flexible and multifunctional chitosan-based bionanocomposites with a mixed reduced graphene oxide-iron oxide (rGO-Fe3-xO4) filler is described. The filler is prepared by one-pot synthesis, ensuring good dispersibility of the Fe3-xO4 nanoparticles and rGO within the chitosan matrix during solvent casting. The resulting bionanocomposites present superparamagnetic response at room temperature. The antioxidant activity is 9 times higher than that of pristine chitosan. The mechanical properties of the films can be tuned from elastic (∼8 MPa) chitosan films to stiff (∼285 MPa) bionanocomposite films with 50% filler. The magnetic hyperthermia tests showed a temperature increase of 40 °C in 45 s for the 50% rGO-Fe3-xO4 film. Furthermore, the composites have no cytotoxicity to the nontumorigenic (HaCat) cell line, which confirms their biocompatibility and highlights the potential of these materials for biomedical applications, such as hyperthermia treatments.

Conductive polysaccharides-based proton-exchange membranes for fuel cell applications: The case of bacterial cellulose and fucoidan.

Conductive natural-based separators for application in polymer electrolyte fuel cells (PEFCs) were fabricated by combining a bacterial polysaccharide, i.e. bacterial cellulose (BC), and an algae sulphated polysaccharide, i.e. fucoidan (Fuc). The diffusion of fucoidan aqueous solution containing a natural-based cross-linker, viz. tannic acid, into the wet BC nanofibrous three-dimensional network, followed by thermal cross-linking, originated fully bio-based proton exchange membranes (PEMs). The PEMs present thermal-oxidative stability in the range of 180-200 °C and good dynamic mechanical performance (storage modulus ≥ 460 MPa). Additionally, the BC/Fuc membranes exhibit protonic conductivity that increases with increasing relative humidity (RH), which is a typical feature for numerous water-mediated proton conductors. The traditional Arrhenius-type plots demonstrate a linear behaviour with a maximum protonic conductivity of 1.6 mS cm-1 at 94 °C and 98 % RH. The results showed that these fully bio-based conductive membranes have potential as eco-friendly alternatives to other PEMs for application in PEFCs.

Behavior and biochemical responses of the polychaeta Hediste diversicolor to polystyrene nanoplastics.

Plastic debris has been reaching the world's oceans since it started being used. Multiple studies have been addressing the effects of microplastics in various organisms but, despite the increased scientific awareness, there is still a significant gap in knowledge when it comes to small-sized plastic particles of sizes below 100 nm. The aim of this study was to understand the effect of waterborne 100 nm polystyrene nanoplastics (PS NPs) on the marine polychaeta Hediste diversicolor, a keystone species in intertidal and coastal environments, in terms of behavior, neurotransmission, oxidative status, energy metabolism and oxidative damage. Results of PS NPs characterization showed an aggregation along the time and with increasing concentrations. Results also revealed a considerable impact of PS NPs on ecologically relevant endpoints like cholinesterase (ChE) and burrowing, but no increases in most of the parameters associated with oxidative stress. Protein carbonylation was found to be more sensitive to PS NPs effects than lipid peroxidation. Behavioral alterations induced by PS NPs may affect nutrient cycling and (endo-)benthic fauna. The data revealed in this study highlighted the potential consequences of NPs to benthic organisms and the need for further studies.

Establishment of a brain cell line (FuB-1) from mummichog (Fundulus heteroclitus) and its application to fish virology, immunity and nanoplastics toxicology.

The marine fish mummichog (Fundulus heteroclitus), extensively used as research model, including in ecotoxicology, for over a century has been surpassed by other fish species. This fact may be associated with the lack of cell lines from this species, excellent models for the comprehension of fish physiology, immunology, toxicology and virology, that contribute to the reduction in the number of animals used in research. We have generated, for the first time, a brain-derived cell line from mummichog, FuB-1, and evaluated its application to the fields of fish virology, immunity and toxicology. First, FuB-1 cells show epithelial morphology and neural stem/astroglial origin. Secondly, FuB-1 cells effectively supports the replication of both spring viremia carp (SVCV) and infectious pancreatic necrosis (IPNV) viruses, but not nodavirus (NNV), indicating its potential use for fish virology. Related to this, FuB-1 cells infected with NNV up-regulate the transcription of genes related to the antiviral immune response, leading to cell resistance; while they are unaltered when infected with IPNV and SVCV, facilitating viral replication. Finally, FuB-1 cells were used for toxicological purposes and we demonstrated that exposure to either polystyrene nanoplastics (PS-100) or several human-usage pharmaceuticals are cytotoxic. Additionally, PS-100 particles increase the antioxidant catalase and glutathione S-transferase activities and decrease the total non-protein thiols in FuB-1 cells. However, PS-100 particles are able to reduce the cytotoxic effects induced by the pharmaceuticals. In conclusion, we have generated a cell line from mummichog, which might represent a valuable model for fish studies in the fields of virology, immunology and toxicology.

Geospatial analysis applied to seroepidemiological survey of canine leishmaniosis in east-central Portugal.

Despite the high prevalence of canine Leishmania infantum infection in Portugal, significant differences associated with different risk factors can be found between geographically contiguous areas. In this study, a geographical area within the central region of Portugal (municipalities of Proença-a-Nova, Mação and Vila de Rei) was investigated. An epidemiological survey involved the analysis by an indirect enzyme-linked immunosorbent assay of serum samples collected during the anti-rabies vaccination campaign from 282 dogs. Geospatial analysis showed the distribution of geospatial prevalence of leishmaniosis and has delimited two areas (clusters) with a statistically significant higher risk of seropositivity in dogs (p =  0.003 and p = 0.027, for clusters 1 and 2, respectively). The highest seroprevalence (56.0%; CI: 41.2-70.0) was found in Vila de Rei. Five land occupation types showed a possible influence on the geographic distribution of seropositivity, with statistically significant differences between seropositive and seronegative dogs. Land occupied by temporary irrigated crops (p =  0.026), olive groves (p =  0.013), complex cultural systems and parcelling (p =  0.021), open forests, logging and new plantations (p =  0.043) and watercourses (p =  0.012) influenced the geographical distribution of canine Leishmania infection. Seropositive dogs had a greater average area of occupied land (i.e. open forests, logging and new plantations) than the seronegative ones (3.1439 km2 versus 2.5650 km2, respectively; p =  0.043).

The effects of nanoplastics on marine plankton: A case study with polymethylmethacrylate.

Marine biota is currently exposed to plastic pollution. The biological effects of plastics may vary according to polymer types (e.g. polystyrene, polyethylene, acrylate), size of particles (macro, micro or nanoparticles) and their shape. There is a considerable lack of knowledge in terms of effects of nanoplastics (NP) to marine biota particularly of polymers like polymethylmethacrylate (PMMA). Thus, this study aimed to assess its ecotoxicological effects using a battery of standard monospecific bioassays with four marine microalgae (Tetraselmis chuii, Nannochloropsis gaditana, Isochrysis galbana and Thalassiosira weissflogii) and a marine rotifer species (Brachionus plicatilis). The tested PMMA-NP concentrations allowed the estimation of median effect concentrations for all microalgae species. T. weissflogii and T. chuii were respectively the most sensitive (EC50,96h of 83.75 mg/L) and least sensitive species (EC50,96h of 132.52 mg/L). The PMMA-NP were also able to induce mortality in rotifers at concentrations higher than 4.69 mg/L with an estimated 48 h median lethal concentration of 13.27 mg/L. A species sensitivity distribution curve (SSD), constructed based on data available in the literature and the data obtained in this study, reveal that PMMA-NP appears as less harmful to marine biota than other polymers like polystyrene.

Polystyrene nanoplastics alter the cytotoxicity of human pharmaceuticals on marine fish cell lines.

There is an increasing concern on the consequences of the presence of micro(nano)plastics to marine organisms. The present study aimed to provide information on the effects of polystyrene nanoplastics (PSNPs) to fish cells alone and combined with human pharmaceuticals, other emerging contaminants, using as biological models marine fish cell lines SAF-1 and DLB-1. Cells were exposed for 24 h to 100 nm PSNPs, starting at 0.001 up to 10 mg/L, to assess effects on viability and activity of catalase (antioxidant defense) and glutathione S-transferases (phase II biotransformation and antioxidant defense). The viability of cells was also evaluated after exposure to human pharmaceuticals alone and combined with PSNPs. Overall, PSNPs failed to be cytotoxic but data proved their ability to alter the toxicity of human pharmaceuticals. DLB-1 was the most sensitive cell line to PSNPs. Data support the use of marine fish cell lines in the study of the effects of micro(nano)plastics.

Tuning lysozyme nanofibers dimensions using deep eutectic solvents for improved reinforcement ability.

Deep eutectic solvents (DESs), a novel generation of solvents, have recently been described as efficient and timesaving fibrillation agents for proteins. In this context, the present work aims at assessing the effect of the hydrogen bond donor (HBD) of cholinium chloride ([Ch]Cl):carboxylic acid based DESs on the dimensions (length and width) of lysozyme nanofibers (LNFs). Mono-, di- and tri-carboxylic acids (acetic, lactic, levulinic, malic and citric acids) were used to prepare different DES formulations, which were successfully used on the fibrillation of lysozyme. The results showed that the carboxylic acid (i.e. the HBD) plays an important role on the fibrillation efficiency and on the length of the ensuing LNFs with aspect-ratios always higher than those obtained by fibrillation with [Ch]Cl. The longest LNFs were obtained using lactic acid as the HBD with an average length of 1004 ±â€¯334 nm and width of 31.8 ±â€¯6.8 nm, and thus an aspect-ratio of ca. 32. The potential of these protein nanofibers as reinforcing additives was evaluated by preparing pullulan (PL)-based nanocomposite films containing 5% LNFs with different aspect-ratios, resulting in highly homogenous and transparent films with improved mechanical performance.

Applying differential dynamic logic to reconfigurable biological networks.

Qualitative and quantitative modeling frameworks are widely used for analysis of biological regulatory networks, the former giving a preliminary overview of the system's global dynamics and the latter providing more detailed solutions. Another approach is to model biological regulatory networks as hybrid systems, i.e., systems which can display both continuous and discrete dynamic behaviors. Actually, the development of synthetic biology has shown that this is a suitable way to think about biological systems, which can often be constructed as networks with discrete controllers, and present hybrid behaviors. In this paper we discuss this approach as a special case of the reconfigurability paradigm, well studied in Computer Science (CS). In CS there are well developed computational tools to reason about hybrid systems. We argue that it is worth applying such tools in a biological context. One interesting tool is differential dynamic logic (dL), which has recently been developed by Platzer and applied to many case-studies. In this paper we discuss some simple examples of biological regulatory networks to illustrate how dL can be used as an alternative, or also as a complement to methods already used.