2,259 results match your criteria: "NOVA School of Science and Technology | NOVA FCT[Affiliation]"

Sustainable production of porous chitosan microparticles by energy-efficient membrane emulsification.

Heliyon

June 2024

LAQV/Requimte, Department of Chemistry, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516, Caparica, Portugal.

In drug delivery, it is common to use porous particles as carrier media, instead of dense particles, due to their high specific surface area and available entrapment volume, which allows a higher amount of drug to be encapsulated and then released. Chitosan microparticles are extensively used in drug delivery, but porous chitosan microparticles are scarcely reported. In this work, the preparation of porous chitosan microparticles using membrane emulsification is addressed, a technology that involves mild operating conditions and less energy consumption than traditional methods (such as ultrasound), and with higher control of the particle size.

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Widespread horse-based mobility arose around 2200 BCE in Eurasia.

Nature

July 2024

Centre d'Anthropobiologie et de Génomique de Toulouse, CNRS UMR 5288, Université Paul Sabatier, Faculté de Médecine Purpan, Toulouse, France.

Article Synopsis
  • - Horses transformed human mobility, but the timeline of their domestication and integration as transport is debated, with new genetic data being used to clarify this history.
  • - Analysis of 475 ancient horse genomes indicates that modern domestic horses were shaped by human intervention around 2200 BCE, after a domestication bottleneck began around 2700 BCE, leading to a significant expansion across Eurasia.
  • - Evidence also suggests that there was early horse husbandry in central Asia at Botai around 3500 BCE, prior to the establishment of contemporary horse bloodlines, challenging the notion of large herds being linked to migrations around 3000 BCE.
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Global and Regional Cardiovascular Mortality Attributable to Nonoptimal Temperatures Over Time.

J Am Coll Cardiol

June 2024

Climate, Air Quality Research Unit, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. Electronic address:

Background: The association between nonoptimal temperatures and cardiovascular mortality risk is recognized. However, a comprehensive global assessment of this burden is lacking.

Objectives: The goal of this study was to assess global cardiovascular mortality burden attributable to nonoptimal temperatures and investigate spatiotemporal trends.

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The immune system in Parkinson's disease: what we know so far.

Brain

October 2024

Department of Biomedicine & The Danish Research Institute of Translational Neuroscience-DANDRITE, Aarhus University, DK-8000 Aarhus C, Denmark.

Parkinson's disease is characterized neuropathologically by the degeneration of dopaminergic neurons in the ventral midbrain, the accumulation of α-synuclein (α-syn) aggregates in neurons and chronic neuroinflammation. In the past two decades, in vitro, ex vivo and in vivo studies have consistently shown the involvement of inflammatory responses mediated by microglia and astrocytes, which may be elicited by pathological α-syn or signals from affected neurons and other cell types, and are directly linked to neurodegeneration and disease development. Apart from the prominent immune alterations seen in the CNS, including the infiltration of T cells into the brain, more recent studies have demonstrated important changes in the peripheral immune profile within both the innate and adaptive compartments, particularly involving monocytes, CD4+ and CD8+ T cells.

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The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity.

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Stabilizing and Activating Active Sites: 1T-MoS Supported Pd Single Atoms for Efficient Hydrogen Evolution Reaction.

Small

October 2024

Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences, Beijing, 100083, China.

Article Synopsis
  • 1T-MoS is a promising catalyst for hydrogen evolution due to its high conductivity and Pt-like activity, but it's difficult to produce in pure forms because of high energy requirements and unstable properties.
  • A new method involves anchoring a thin layer of 1T-MoS on carbon and integrating single Pd atoms, which enhances stability and modifies the electronic structure, resulting in a strong catalyst.
  • The optimized Pd/1T-MoS/C catalyst shows exceptional performance for hydrogen evolution, with low overpotential and resistance in various electrolytes, thanks to the ideal properties of the sulfur sites bonded with Pd.
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Using a 3D geometric morphometrics approach, we shed light on the major changes during the ontogenetic development of Hippopotamus amphibius. The main shift in the shape variability of cranial elements in juveniles can probably be related to the interruption of suckling. A less stressed shift in the cranial variability can probably be related to the attainment of sexual maturity.

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Article Synopsis
  • Yeasts in the Saccharomycotina subphylum typically conserve genes for key metabolic processes like alcoholic fermentation, but fructophilic species in the Wickerhamiella and Starmerella genera show unique adaptations due to gene loss and horizontal gene transfer.
  • Researchers analyzed 63 genomes from this clade, identifying nine HGT events and secondary gene losses that affect sugar metabolism and fermentation processes.
  • Unexpected findings included instances of fructophily and alcoholic fermentation occurring without expected key genes, implying significant innovation in sugar metabolism linked to the evolutionary history of the W/S clade.
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Gene expression is temporally and spatially regulated by the interaction of transcription factors (TFs) and cis-regulatory elements (CREs). The uneven distribution of TF binding sites across the genome poses challenges in understanding how this distribution evolves to regulate spatio-temporal gene expression and consequent heritable phenotypic variation. In this study, chromatin accessibility profiles and gene expression profiles were collected from several species including mammals (human, mouse, bovine), fish (zebrafish and medaka), and chicken.

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Glioma is currently one of the most prevalent types of primary brain cancer. Given its high level of heterogeneity along with the complex biological molecular markers, many efforts have been made to accurately classify the type of glioma in each patient, which, in turn, is critical to improve early diagnosis and increase survival. Nonetheless, as a result of the fast-growing technological advances in high-throughput sequencing and evolving molecular understanding of glioma biology, its classification has been recently subject to significant alterations.

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The development of new Drug Delivery Systems (DDS) by incorporating microparticles within hydrogels can prolong the release rate of drugs and/or other bioactive agents. In this study, we combined gellan gum/alginate microparticles within a thermoresponsive chitosan (Ch) hydrogel with β-Glycerophosphate (β-GP), designing the system to be in the sol state at 21 °C and in the gel state at 37 °C to enable the injectability of the system. The system was in the sol state between 10 °C and 21 °C.

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Challenges imposed by geographical barriers during migration are selective agents for animals. Juvenile soaring landbirds often cross large water bodies along their migratory path, where they lack updraft support and are vulnerable to harsh weather. However, the consequences of inexperience in accomplishing these water crossings remain largely unquantified.

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Article Synopsis
  • * Researchers developed a model that helps measure junction and nanoparticle resistances by analyzing DC network resistivity data depending on the particle size.
  • * The model also enables the extraction of resistance data from AC impedance spectra, linking high mobility in certain nanosheet networks to low junction resistances and providing insights into transport mechanisms within the networks.
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Article Synopsis
  • Understanding inhibitor binding at metalloenzymes is critical for rational drug design, but structural measurement uncertainties hinder reliable quantum chemical calculations.
  • Advanced computational methods are necessary to refine active site structures beyond traditional experimental techniques.
  • A novel approach combining neural networks and support vector regression has shown great promise in improving structural accuracy, as demonstrated by the refined active site of human carbonic anhydrase 2, paving the way for further drug target investigations.
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Objectives: To investigate the association among sun exposure time, vitamin D intake, dietary patterns, and socioeconomic status in Portuguese children.

Methods: Participants aged 3-11 years (50.1% females) were recruited from public and private schools (n = 118) in the districts of Coimbra (n = 2980), Lisbon (n = 3066), and Porto (n = 2426).

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Steering and cloaking of hyperbolic polaritons at deep-subwavelength scales.

Nat Commun

May 2024

CAS Key Laboratory of Nanophotonic Materials and Devices, CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, Beijing, 100190, P. R. China.

Polaritons are well-established carriers of light, electrical signals, and even heat at the nanoscale in the setting of on-chip devices. However, the goal of achieving practical polaritonic manipulation over small distances deeply below the light diffraction limit remains elusive. Here, we implement nanoscale polaritonic in-plane steering and cloaking in a low-loss atomically layered van der Waals (vdW) insulator, α-MoO, comprising building blocks of customizable stacked and assembled structures.

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Ammonia Detection by Electronic Noses for a Safer Work Environment.

Sensors (Basel)

May 2024

Laboratory of Instrumentation, Biomedical Engineering and Radiation Physics (LIBPhys-UNL), Department of Physics, NOVA School of Science and Technology, NOVA University of Lisbon, 2829-516 Caparica, Portugal.

Providing employees with proper work conditions should be one of the main concerns of any employer. Even so, in many cases, work shifts chronically expose the workers to a wide range of potentially harmful compounds, such as ammonia. Ammonia has been present in the composition of products commonly used in a wide range of industries, namely production in lines, and also laboratories, schools, hospitals, and others.

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The resistance of nickel-titanium endodontic instruments against cyclic fatigue failure remains a significant concern in clinical settings. This study aimed to assess the cyclic fatigue strength of five nickel-titanium rotary systems, while correlating the results with the instruments' geometric and metallurgical characteristics. A total of 250 new instruments (sizes S1/A1, S2/A2, F1/B1, F2/B2, F3/B3) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-Files systems underwent mechanical testing.

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Environmental degradation leads to an unsustainable food system. In addition to this issue, the consumption of foods that improve people's health and well-being is recommended. One of the alternatives is undoubtedly the use of by-products of winemaking, namely in the form of grape pomace flour (GPF).

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A miniaturised semi-dynamic in-vitro model of human digestion.

Sci Rep

May 2024

International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga, S/N, 4715-330, Braga, Portugal.

Reliable in-vitro digestion models that are able to successfully replicate the conditions found in the human gastrointestinal tract are key to assess the fate and efficiency of new formulations aimed for oral consumption. However, current in-vitro models either lack the capability to replicate crucial dynamics of digestion or require large volumes of sample/reagents, which can be scarce when working with nanomaterials under development. Here, we propose a miniaturised digestion system, a digestion-chip, based on incubation chambers integrated on a polymethylmethacrylate device.

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Development of a New Aggregation Method to Remove Nanoplastics from the Ocean: Proof of Concept Using Mussel Exposure Tests.

Biomimetics (Basel)

May 2024

i4HB-Associate Laboratory Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2819-516 Caparica, Portugal.

The overproduction and mismanagement of plastics has led to the accumulation of these materials in the environment, particularly in the marine ecosystem. Once in the environment, plastics break down and can acquire microscopic or even nanoscopic sizes. Given their sizes, microplastics (MPs) and nanoplastics (NPs) are hard to detect and remove from the aquatic environment, eventually interacting with marine organisms.

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, a foodborne pathogen, exhibits high adaptability to adverse environmental conditions and is common in the food industry, especially in ready-to-eat foods. strains pose food safety challenges due to their ability to form biofilms, increased resistance to disinfectants, and long-term persistence in the environment. The aim of this study was to evaluate the presence and genetic diversity of in food and related environmental products collected from 2014 to 2022 and assess antibiotic susceptibility and biofilm formation abilities.

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Unraveling the Complexity of DNA Radiation Damage Using DNA Nanotechnology.

Acc Chem Res

June 2024

Institute of Chemistry, Hybrid Nanostructures, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany.

Radiation cancer therapies use different ionizing radiation qualities that damage DNA molecules in tumor cells by a yet not completely understood plethora of mechanisms and processes. While the direct action of the radiation is significant, the byproducts of the water radiolysis, mainly secondary low-energy electrons (LEEs, <20 eV) and reactive oxygen species (ROS), can also efficiently cause DNA damage, in terms of DNA strand breakage or DNA interstrand cross-linking. As a result, these types of DNA damage evolve into mutations hindering DNA replication, leading to cancer cell death.

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Drug-induced gingival enlargement (DIGE) is a side effect of ciclosporin, calcium channel blockers, and phenytoin. DIGE is a serious disease that leads to masticatory and esthetic disorders, severe caries, and periodontitis but currently has no standard treatment. We recently reported that nuclear receptor 4A1 (NR4A1) is a potential therapeutic target for DIGE.

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Directed conservation of the world's reef sharks and rays.

Nat Ecol Evol

June 2024

Institute of Environment, Department of Biological Sciences, Florida International University, North Miami, FL, USA.

Many shark populations are in decline around the world, with severe ecological and economic consequences. Fisheries management and marine protected areas (MPAs) have both been heralded as solutions. However, the effectiveness of MPAs alone is questionable, particularly for globally threatened sharks and rays ('elasmobranchs'), with little known about how fisheries management and MPAs interact to conserve these species.

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