Computer-aided autism diagnosis using visual attention models and eye-tracking: replication and improvement proposal.

BACKGROUND: Autism Spectrum Disorder (ASD) diagnosis can be aided by approaches based on eye-tracking signals. Recently, the feasibility of building Visual Attention Models (VAMs) from features extracted from visual stimuli and their use for classifying cases and controls has been demonstrated using Neural Networks and Support Vector Machines. The present work has three aims: 1) to evaluate whether the trained classifier from the previous study was generalist enough to classify new samples with a new stimulus; 2) to replicate the previously approach to train a new classifier with a new dataset; 3) to evaluate the performance of classifiers obtained by a new classification algorithm (Random Forest) using the previous and the current datasets. METHODS: The previously approach was replicated with a new stimulus and new sample, 44 from the Typical Development group and 33 from the ASD group. After the replication, Random Forest classifier was tested to substitute Neural Networks algorithm. RESULTS: The test with the trained classifier reached an AUC of 0.56, suggesting that the trained classifier requires retraining of the VAMs when changing the stimulus. The replication results reached an AUC of 0.71, indicating the potential of generalization of the approach for aiding ASD diagnosis, as long as the stimulus is similar to the originally proposed. The results achieved with Random Forest were superior to those achieved with the original approach, with an average AUC of 0.95 for the previous dataset and 0.74 for the new dataset. CONCLUSION: In summary, the results of the replication experiment were satisfactory, which suggests the robustness of the approach and the VAM-based approaches feasibility to aid in ASD diagnosis. The proposed method change improved the classification performance. Some limitations are discussed and additional studies are encouraged to test other conditions and scenarios.

Rheological design of thickened alcohol-based hand rubs.

The handleability and sensory perception of hand sanitisers by consumers affect the hygiene outcome. Spillage may result in under-dosing and poor sensory properties can lead to under-utilisation. We first propose four principles (low runoff, spreadability, smoothness and non-stickiness) for designing the rheology of thickened alcohol-based hand rubs with acceptable handleability and hand feel. We then evaluate a commercial hand gel and a variety of simplified formulations thickened with microgels (Carbopol 974P, Carbopol Ultrez 20 and Sepimax Zen), or linear polymers (Jaguar HP 120 COS), and evaluate them against these design criteria. All four additives provide acceptable spreadability by shear thinning to η ≈ 10 - 1 Pa s at γ ˙ ∼ 10 3 s - 1 . Either the finite yield stress conferred by the microgels ( σ y ≳ 10 Pa ) or the increase in low-shear viscosity provided by the linear polymer ( η ≳ 1 Pa s at γ ˙ ≲ 0.1 s - 1 ) give rise to acceptably low runoff. However, the formulation using the linear polymer shows a filament breakage time of τ b ≈ 1 s in capillary rheology, which may result in stickiness and therefore a less than optimal hand feel.

Catalytic Transfer Hydrogenation and Acid Reactions of Furfural and 5-(Hydroxymethyl)furfural over Hf-TUD-1 Type Catalysts.

Heterogeneous catalysis, which has served well the petrochemical industry, may valuably contribute towards a bio-based economy by sustainably enabling selective reactions to renewable chemicals. Carbohydrate-containing matter may be obtained from various widespread sources and selectively converted to furanic platform chemicals: furfural (Fur) and 5-(hydroxymethyl)furfural (Hmf). Valuable bioproducts may be obtained from these aldehydes via catalytic transfer hydrogenation (CTH) using alcohols as H-donors under relatively moderate reaction conditions. Hafnium-containing TUD-1 type catalysts were the first of ordered mesoporous silicates explored for the conversion of Fur and Hmf via CTH/alcohol strategies. The materials promoted CTH and acid reactions leading to the furanic ethers. The bioproducts spectrum was broader for the reaction of Fur than of Hmf. A Fur reaction mechanism based on literature data was discussed and supported by kinetic modelling. The influence of the Hf loading and reaction conditions (catalyst load, type of alcohol H-donor, temperature, initial substrate concentration) on the reaction kinetics was studied. The reaction conditions were optimized to maximize the yields of 2-(alkoxymethyl)furan ethers formed from Fur; up to 63% yield was reached at 88% Fur conversion, 4 h/150 °C, using Hf-TUD-1(75), which was a stable catalyst. The Hf-TUD-1(x) catalysts promoted the selective conversion of Hmf to bis(2-alkoxymethyl)furan; e.g., 96% selectivity at 98% Hmf conversion, 3 h/170 °C for Hf-TUD-1(50).

Soft matter science and the COVID-19 pandemic.

Much of the science underpinning the global response to the COVID-19 pandemic lies in the soft matter domain. Coronaviruses are composite particles with a core of nucleic acids complexed to proteins surrounded by a protein-studded lipid bilayer shell. A dominant route for transmission is via air-borne aerosols and droplets. Viral interaction with polymeric body fluids, particularly mucus, and cell membranes controls their infectivity, while their interaction with skin and artificial surfaces underpins cleaning and disinfection and the efficacy of masks and other personal protective equipment. The global response to COVID-19 has highlighted gaps in the soft matter knowledge base. We survey these gaps, especially as pertaining to the transmission of the disease, and suggest questions that can (and need to) be tackled, both in response to COVID-19 and to better prepare for future viral pandemics.

Effect of Oven-Drying on the Recovery of Valuable Compounds from Ulva rigida, Gracilaria sp. and Fucus vesiculosus.

The effect of oven-drying at 25, 40 and 60 °C was evaluated on three macroalgae of relevance in Europe, namely Ulva rigida, Gracilaria sp. and Fucus vesiculosus, with respect to quality aspects, including their potential to be exploited as a source of valuable compounds. Notably, as compared to freeze-drying, oven-drying at 25 °C promoted the extraction of chlorophylls and carotenoids from U. rigida, as well as those of phycoerythrin and chlorophyll a from Gracilaria sp., while 40 °C favored the recovery of fucoxanthin and pheophytin a from F. vesiculosus. On the other hand, the use of oven-drying had a negative impact on the extraction of phenolic compounds from this alga, also diminishing the antioxidant activity of the resulting extracts. Instead, the impact of oven-drying of raw material on the recovery of specific polysaccharides differed among the macroalgae. While the amounts of ulvans and fucoidans obtained from macroalgae dried at higher temperatures tended to be superior, the recovery of agar was not affected with the drying temperatures applied to Gracilaria sp. The overall results showed that oven-drying might serve as a good alternative to stabilize Ulva rigida, Gracilaria sp. and Fucus vesiculosus, especially if extraction of pigments and polysaccharides is aimed, thought the appropriate temperature applied must be adapted for each macroalgae.

Respiratory complex I: A dual relation with H(+) and Na(+)?

Respiratory complex I couples NADH:quinone oxidoreduction to ion translocation across the membrane, contributing to the buildup of the transmembrane difference of electrochemical potential. H(+) is well recognized to be the coupling ion of this system but some studies suggested that this role could be also performed by Na(+). We have previously observed NADH-driven Na(+) transport opposite to H(+) translocation by menaquinone-reducing complexes I, which indicated a Na(+)/H(+) antiporter activity in these systems. Such activity was also observed for the ubiquinone-reducing mitochondrial complex I in its deactive form. The relation of Na(+) with complex I may not be surprising since the enzyme has three subunits structurally homologous to bona fide Na(+)/H(+) antiporters and translocation of H(+) and Na(+) ions has been described for members of most types of ion pumps and transporters. Moreover, no clearly distinguishable motifs for the binding of H(+) or Na(+) have been recognized yet. We noticed that in menaquinone-reducing complexes I, less energy is available for ion translocation, compared to ubiquinone-reducing complexes I. Therefore, we hypothesized that menaquinone-reducing complexes I perform Na(+)/H(+) antiporter activity in order to achieve the stoichiometry of 4H(+)/2e(-). In agreement, the organisms that use ubiquinone, a high potential quinone, would have kept such Na(+)/H(+) antiporter activity, only operative under determined conditions. This would imply a physiological role(s) of complex I besides a simple "coupling" of a redox reaction and ion transport, which could account for the sophistication of this enzyme. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.

Exploring membrane respiratory chains.

Acquisition of energy is central to life. In addition to the synthesis of ATP, organisms need energy for the establishment and maintenance of a transmembrane difference in electrochemical potential, in order to import and export metabolites or to their motility. The membrane potential is established by a variety of membrane bound respiratory complexes. In this work we explored the diversity of membrane respiratory chains and the presence of the different enzyme complexes in the several phyla of life. We performed taxonomic profiles of the several membrane bound respiratory proteins and complexes evaluating the presence of their respective coding genes in all species deposited in KEGG database. We evaluated 26 quinone reductases, 5 quinol:electron carriers oxidoreductases and 18 terminal electron acceptor reductases. We further included in the analyses enzymes performing redox or decarboxylation driven ion translocation, ATP synthase and transhydrogenase and we also investigated the electron carriers that perform functional connection between the membrane complexes, quinones or soluble proteins. Our results bring a novel, broad and integrated perspective of membrane bound respiratory complexes and thus of the several energetic metabolisms of living systems. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.

Impact of temperature on ophthalmic viscosurgical devices and clinical implications: a pilot study.

PURPOSE: To evaluate how temperature affects the rheology of common ophthalmic viscosurgical devices (OVDs) and clinical implications. SETTING: Tennent Institute of Ophthalmology, Glasgow, with Department of Mechanical and Aerospace Engineering, and Advanced Materials Research Laboratory, University of Strathclyde, Glasgow, United Kingdom. DESIGN: Laboratory pilot study. METHODS: The viscous and elastic responses of 3 OVDs (Eyefill-SC/Eyefill-C/Eyefill-HD) were measured using rotational and extensional rheometers at clinically relevant temperatures (5°C, 25°C, 37°C). Thermal properties were evaluated using differential scanning calorimetry and laser-flash analysis. RESULTS: The OVDs tested exhibited viscoelastic properties and shear-thinning behavior. Apparent viscosities and relaxation time were higher at lower temperatures. The Eyefill-C and Eyefill-SC exhibited predominantly viscous character at low frequencies with a transition to predominantly elastic behavior at high frequencies. An increase in temperature led to a decrease in relaxation time under shear and extension. At low frequencies, Eyefill-C and Eyefill-SC moduli increase with decreasing temperatures. Eyefill-HD at 25°C and 37°C displays 2 crossover points, with the storage modulus dominating at low and high frequencies indicating a predominantly elastic behavior. Thermal property analysis revealed Eyefill-C had the lowest thermal conductivity. CONCLUSIONS: This pilot study confirms our clinical experience that OVD properties are affected by low temperatures, with increased viscosities at low shear rates and higher relaxation times. Cold OVD can cause greater resistance to initiation of intraocular lens (IOL) injection system forces (compared with warmer OVD). Excessively forced injection using cold OVD could contribute to inadvertent cannula detachment if incorrectly assembled, or uncontrolled IOL release leading to avoidable injury.

A vertical additive-lathe printing system for the fabrication of tubular constructs using gelatin methacryloyl hydrogel.

Reproducing both the mechanical and biological performance of native blood vessels remains an ongoing challenge in vascular tissue engineering. Additive-lathe printing offers an attractive method of fabricating long tubular constructs as a potential vascular graft for the treatment of cardiovascular diseases. Printing hydrogels onto rotating horizontal mandrels often leads to sagging, resulting in poor and variable mechanical properties. In this study, an additive-lathe printing system with a vertical mandrel to fabricate tubular constructs is presented. Various concentrations of gelatin methacryloyl (gelMA) hydrogel were used to print grafts on the rotating mandrel in a helical pattern. The printing parameters were selected to achieve the bonding of consecutive gelMA filaments to improve the quality of the printed graft. The hydrogel filaments were fused properly under the action of gravity on the vertical mandrel. Thus, the vertical additive-lathe printing system was used to print uniform wall thickness grafts, eliminating the hydrogel sagging problem. Tensile testing performed in both circumferential and longitudinal direction revealed that the anisotropic properties of printed gelMA constructs were similar to those observed in the native blood vessels. In addition, no leakage was detected through the walls of the gelMA grafts during burst pressure measurement. Therefore, the current printing setup could be utilized to print vascular grafts for the treatment of cardiovascular diseases.

Tricarbonyl-Pyrazine-Molybdenum(0) Metal-Organic Frameworks for the Storage and Delivery of Biologically Active Carbon Monoxide.

Metal-organic frameworks (MOFs) have high potential as nanoplatforms for the storage and delivery of therapeutic gasotransmitters or gas-releasing molecules. The aim of the present study was to open an investigation into the viability of tricarbonyl-pyrazine-molybdenum(0) MOFs as carbon monoxide-releasing materials (CORMAs). A previous investigation found that the reaction of Mo(CO)6 with excess pyrazine (pyz) in a sealed ampoule gave a mixture comprising a major triclinic phase with pyz-occupied hexagonal channels, formulated as fac-Mo(CO)3(pyz)3/2·1/2pyz (Mo-hex), and a minor dense cubic phase, formulated as fac-Mo(CO)3(pyz)3/2 (Mo-cub). In the present work, an open reflux method in toluene has been optimized for the large-scale synthesis of the pure Mo-cub phase. The crystalline solids Mo-hex and Mo-cub were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), FT-IR and FT-Raman spectroscopies, and 13C{1H} cross-polarization (CP) magic-angle spinning (MAS) NMR spectroscopy. The release of CO from the MOFs was studied by the deoxy-myoglobin (deoxy-Mb)/carbonmonoxy-myoglobin (MbCO) UV-vis assay. Mo-hex and Mo-cub release CO upon contact with a physiological buffer in the dark, delivering 0.35 and 0.22 equiv (based on Mo), respectively, after 24 h, with half-lives of 3-4 h. Both materials display high photostability such that the CO-releasing kinetics is not affected by irradiation of the materials with UV light. These materials are attractive as potential CORMAs due to the slow release of a high CO payload. In the solid-state and under open air, Mo-cub underwent almost complete decarbonylation over a period of 4 days, corresponding to a theoretical CO release of 10 mmol per gram of material.

New Insights on Sperm Function in Male Infertility of Unknown Origin: A Multimodal Approach.

The global trend of rising (male) infertility is concerning, and the unidentifiable causes in half of the cases, the so-called unknown origin male infertility (UOMI), demands a better understanding and assessment of both external/internal factors and mechanisms potentially involved. In this work, it was our aim to obtain new insight on UOMI, specifically on idiopathic (ID) and Unexplained male infertility (UMI), relying on a detailed evaluation of the male gamete, including functional, metabolic and proteomic aspects. For this purpose, 1114 semen samples, from males in couples seeking infertility treatment, were collected at the Reproductive Medicine Unit from the Centro Hospitalar e Universitário de Coimbra (CHUC), from July 2018-July 2022. Based on the couples' clinical data, seminal/hormonal analysis, and strict eligibility criteria, samples were categorized in 3 groups, control (CTRL), ID and UMI. Lifestyle factors and anxiety/depression symptoms were assessed via survey. Sperm samples were evaluated functionally, mitochondrially and using proteomics. The results of Assisted Reproduction Techniques were assessed whenever available. According to our results, ID patients presented the worst sperm functional profile, while UMI patients were similar to controls. The proteomic analysis revealed 145 differentially expressed proteins, 8 of which were specifically altered in ID and UMI samples. Acrosin (ACRO) and sperm acrosome membrane-associated protein 4 (SACA4) were downregulated in ID patients while laminin subunit beta-2 (LAMB2), mannose 6-phosphate isomerase (MPI), ATP-dependent 6-phosphofructokinase liver type (PFKAL), STAR domain-containing protein 10 (STA10), serotransferrin (TRFE) and exportin-2 (XPO2) were downregulated in UMI patients. Using random forest analysis, SACA4 and LAMB2 were identified as the sperm proteins with a higher chance of distinguishing ID and UMI patients, and their function and expression variation were in accordance with the functional results. No alterations were observed in terms of lifestyle and psychological factors among the 3 groups. These findings obtained in an experimental setting based on 3 well-defined groups of subjects, might help to validate new biomarkers for unknown origin male infertility (ID and UMI) that, in the future, can be used to improve diagnostics and treatments.

The Impact of Resveratrol-Enriched Bread on Cardiac Remodeling in a Preclinical Model of Diabetes.

The World Health Organization aims to stop the rise of diabetes by 2025, and diet is one of the most efficient non-pharmacological strategies used to prevent it. Resveratrol (RSV) is a natural compound with anti-diabetic properties, and incorporating it into bread is a suitable way to make it more accessible to consumers as it can be included as part of their daily diet. This study aimed to evaluate the effect of RSV-enriched bread in preventing early type 2 diabetes cardiomyopathy in vivo. Male Sprague Dawley rats (3 weeks old) were divided into four groups: controls with plain bread (CB) and RSV bread (CBR), and diabetics with plain bread (DB) and RSV bread (DBR). Type 2 diabetes was induced by adding fructose to the drinking water for two weeks followed by an injection of streptozotocin (STZ) (40 mg/kg). Then, plain bread and RSV bread (10 mg RSV/kg body weight) were included in the rats' diet for four weeks. Cardiac function, anthropometric, and systemic biochemical parameters were monitored, as well as the histology of the heart and molecular markers of regeneration, metabolism, and oxidative stress. Data showed that an RSV bread diet decreased the polydipsia and body weight loss observed in the early stages of the disease. At the cardiac level, an RSV bread diet diminished fibrosis but did not counteract the dysfunction and metabolic changes seen in fructose-fed STZ-injected rats.

Micro/mesoporous LTL derived materials for catalytic transfer hydrogenation and acid reactions of bio-based levulinic acid and furanics.

The biomass-derived platform chemicals furfural and 5-(hydroxymethyl)furfural (HMF) may be converted to α-angelica lactone (AnL) and levulinic acid (LA). Presently, LA (synthesized from carbohydrates) has several multinational market players. Attractive biobased oxygenated fuel additives, solvents, etc., may be produced from AnL and LA via acid and reduction chemistry, namely alkyl levulinates and γ-valerolactone (GVL). In this work, hierarchical hafnium-containing multifunctional Linde type L (LTL) related zeotypes were prepared via top-down strategies, for the chemical valorization of LA, AnL and HMF via integrated catalytic transfer hydrogenation (CTH) and acid reactions in alcohol medium. This is the first report of CTH applications (in general) of LTL related materials. The influence of the post-synthesis treatments/conditions (desilication, dealumination, solid-state impregnation of Hf or Zr) on the material properties and catalytic performances was studied. AnL and LA were converted to 2-butyl levulinate (2BL) and GVL in high total yields of up to ca. 100%, at 200°C, and GVL/2BL molar ratios up to 10. HMF conversion gave mainly the furanic ethers 5-(sec-butoxymethyl)furfural and 2,5-bis(sec-butoxymethyl)furan (up to 63% total yield, in 2-butanol at 200°C/24 h). Mechanistic, reaction kinetics and material characterization studies indicated that the catalytic results depend on a complex interplay of different factors (material properties, type of substrate). The recovered-reused solids performed steadily.

A hafnium-based metal-organic framework for the entrapment of molybdenum hexacarbonyl and the light-responsive release of the gasotransmitter carbon monoxide.

A carbon monoxide-releasing material (CORMA) has been prepared by inclusion of molybdenum hexacarbonyl in a hafnium-based metal-organic framework (MOF) with the UiO-66 architecture. Mo(CO)6 was adsorbed from solution to give supported materials containing 6.0-6.6 wt% Mo. As confirmed by powder X-ray diffraction (PXRD) and SEM coupled with energy dispersive X-ray spectroscopy, neither the crystallinity nor the morphology of the porous host was affected by the loading process. While the general shape of the N2 physisorption isotherms (77 K) did not change significantly after encapsulation of Mo(CO)6, the micropore volume decreased by ca. 20%. Thermogravimetric analysis of the as-prepared materials revealed a weight loss step around 160 °C associated with the decomposition of Mo(CO)6 to subcarbonyl species. Confirmation for the presence of encapsulated Mo(CO)6 complexes was provided by FT-IR and 13C{1H} cross-polarization magic-angle spinning NMR spectroscopies. To test the capability of these materials to behave as CORMAs and transfer CO to heme proteins, the standard myoglobin (Mb) assay was used. While stable in the dark, photoactivation with low-power UV light (365 nm) liberated CO from the encapsulated hexacarbonyl molecules in Mo(6.0)/UiO-66(Hf), leading to a maximum amount of 0.26 mmol CO released per gram of material. Under the simulated physiological conditions of the Mb assay (37 °C, pH 7.4 buffer), minimal leaching of molybdenum occurred, PXRD showed only slight amorphization, and FT-IR spectroscopy confirmed the high chemical stability of the MOF host.

Strategies to Broaden the Applications of Olive Biophenols Oleuropein and Hydroxytyrosol in Food Products.

Oleuropein (OLE) and hydroxytyrosol (HT) are olive-derived phenols recognised as health-promoting agents with antioxidant, anti-inflammatory, cardioprotective, antifungal, antimicrobial, and antitumor activities, providing a wide range of applications as functional food ingredients. HT is Generally Recognised as Safe (GRAS) by the European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA), whereas OLE is included in EFSA daily consumptions recommendations, albeit there is no official GRAS status for its pure form. Their application in food, however, may be hindered by challenges such as degradation caused by processing conditions and undesired sensorial properties (e.g., the astringency of OLE). Among the strategies to overcome such setbacks, the encapsulation in delivery systems and the covalent and non-covalent complexation are highlighted in this review. Additionally, the synthesis of OLE and HT derivatives are studied to improve their applicability. All in all, more research needs however to be carried out to investigate the impact of these approaches on the sensory properties of the final food product and its percussions at the gastrointestinal level, as well as on bioactivity. At last limitations of these approaches at a scale of the food industry must also be considered.

Mitochondrial Functional Assessment in Mammalian Gametes Using Fluorescent Probes.

A positive relationship between mitochondrial functionality and gamete quality, ultimately contributing to fertilization success and normal embryo development has been established for some years now. Both mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) production are major indicators of mitochondrial function, and the need for accurate biomarkers mirroring gamete quality highlights the importance of a precise assessment of mitochondrial quality and function. In this chapter, we discuss the use of some mitochondrial fluorescent probes coupled to flow cytometry and/or fluorescence microscopy to specifically assess mitochondrial ROS production and MMP in both sperm and oocytes. Furthermore, as the distribution/aggregation of mitochondria in the oocyte is of interest to determine its quality, a detailed protocol is also given. These methodologies are easy, accurate and can be safely applied in research- and/or clinical-based contexts.

Computer-aided autism diagnosis based on visual attention models using eye tracking.

An advantage of using eye tracking for diagnosis is that it is non-invasive and can be performed in individuals with different functional levels and ages. Computer/aided diagnosis using eye tracking data is commonly based on eye fixation points in some regions of interest (ROI) in an image. However, besides the need for every ROI demarcation in each image or video frame used in the experiment, the diversity of visual features contained in each ROI may compromise the characterization of visual attention in each group (case or control) and consequent diagnosis accuracy. Although some approaches use eye tracking signals for aiding diagnosis, it is still a challenge to identify frames of interest when videos are used as stimuli and to select relevant characteristics extracted from the videos. This is mainly observed in applications for autism spectrum disorder (ASD) diagnosis. To address these issues, the present paper proposes: (1) a computational method, integrating concepts of Visual Attention Model, Image Processing and Artificial Intelligence techniques for learning a model for each group (case and control) using eye tracking data, and (2) a supervised classifier that, using the learned models, performs the diagnosis. Although this approach is not disorder-specific, it was tested in the context of ASD diagnosis, obtaining an average of precision, recall and specificity of 90%, 69% and 93%, respectively.

Flow dynamics of vitreous humour during saccadic eye movements.

In this work, we reveal the flow dynamics of Vitreous Humour (VH) gel and liquid phases during saccadic movements of the eye, considering the biofluids viscoelastic character as well as realistic eye chamber geometry and taking into account the saccade profile. We quantify the differences in the flow dynamics of VH gel and liquid phases using viscoelastic rheological models that are able to model the VH shear rheology, considering different amplitudes of saccadic movements (10∘, 20∘, 30∘ and 40∘). For this purpose, the computational fluid dynamics (CFD) open source software OpenFOAM® was used. The results portray a distinct flow behaviour for the VH gel and liquid phases, with inertial effects being more significant for the VH liquid phase. Moreover, the Wall Shear Stress (WSS) values produced by the VH gel phase are more than twice of those generated by the VH liquid phase. Results also show that for different amplitudes of eye movement both the velocity magnitude in the vitreous cavity and the shear stresses on the cavity walls rise with increasing saccadic movement displacement.

Poly-Epsilon-Lysine Hydrogels with Dynamic Crosslinking Facilitates Cell Proliferation.

The extracellular matrix (ECM) is a three-dimensional network within which fundamental cell processes such as cell attachment, proliferation, and differentiation occur driven by its inherent biological and structural cues. Hydrogels have been used as biomaterials as they possess many of the ECM characteristics that control cellular processes. However, the permanent crosslinking often found in hydrogels fails to recapitulate the dynamic nature of the natural ECM. This not only hinders natural cellular migration but must also limit cellular expansion and growth. Moreover, there is an increased interest in the use of new biopolymers to create biomimetic materials that can be used for biomedical applications. Here we report on the natural polymer poly-ε-lysine in forming dynamic hydrogels via reversible imine bond formation, with cell attachment promoted by arginine-glycine-aspartic acid (RGD) incorporation. Together, the mechanical properties and cell behavior of the dynamic hydrogels with low poly-ε-lysine quantities indicated good cell viability and high metabolic activity.

Application of Hydroxytyrosol in the Functional Foods Field: From Ingredient to Dietary Supplements.

Hydroxytyrosol (HT) is an amphipathic functional phenol found in the olive tree, both in its leaves and fruits, in free or bound forms, as well as in olive oil and by-products of olive oil manufacture. The European Food Safety Authority recommends regular consumption of HT due to its several beneficial effects on human health, which are closely associated to its antioxidant activity. These reasons make HT an excellent candidate for application as a functional ingredient in the design of novel food products. Patents already exist for methodologies of extraction, purification, and application of HT in supplements and food products. The present review discusses the impact of HT incorporation on food properties and its effects on consumers, based on relevant data related to the use of HT as a functional ingredient, both as a pure compound or in the form of HT-rich extracts, in various food products, namely in edible oils, beverages, bakery products, as well animal-based foods such as meat, fishery and dairy products.