The article presents the modification of ash wood via surface initiated activators regenerated by electron transfer atom transfer radical polymerization mediated by elemental silver (Ag SI-ARGET ATRP) at a diminished catalyst concentration. Ash wood is functionalized with poly(methyl methacrylate) (PMMA) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) to yield wood grafted with PMMA--PDMAEMA-Br copolymers with hydrophobic and antibacterial properties. Fourier transform infrared (FT-IR) spectroscopy confirmed the covalent incorporation of functional ATRP initiation sites and polymer chains into the wood structure. The polymerization kinetics was followed by the analysis of the polymer grown in solution from the sacrificial initiator by proton nuclear magnetic resonance (H NMR) and gel permeation chromatography (GPC). The polymer layer covalently attached to the wood surface was observed by scanning electron microscopy (SEM). The hydrophobic properties of hybrid materials were confirmed by water contact angle measurements. Water and sodium chloride salt aqueous solution uptake tests confirmed a significant improvement in resistance to the absorption of wood samples after modification with polymers. Antibacterial tests revealed that wood-QPDMAEMA-Br, as well as wood-PMMA--QPDMAEMA-Br, exhibited higher antibacterial activity against Gram-positive bacteria () in comparison with Gram-negative bacteria (). The paper presents an economic concept with ecological aspects of improving wood properties, which gives great opportunities to use the proposed approach in the production of functional hybrid materials for industry and high quality sports equipment, and in furniture production.
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http://dx.doi.org/10.3390/molecules27030890 | DOI Listing |
Plant Biol (Stuttg)
December 2024
Department of Silviculture and Forest Ecology of the Temperate Zones, University of Göttingen, Göttingen, Germany.
Temperate mixed forests are currently experiencing severe drought conditions and face increased risk of degradation. However, it remains unclear how critical tree physiological functions such as sap flow density (SFD) and tree water deficit (TWD, defined as reversible stem shrinkage when water is depleted), respond to extreme environmental conditions and how they interact under dry conditions. We monitored SFD and TWD of three co-occurring European tree species (Fagus sylvatica, Fraxinus excelsior and Acer pseudoplatanus) in dry conditions, using high temporal resolution sap flow, dendrometer, and environmental measurements.
View Article and Find Full Text PDFAnal Bioanal Chem
December 2024
DTI-Danish Technological Institute, Aarhus, Denmark.
Biomass is a key element in biofuels which can be defined as a fuel produced through contemporary biological processes, and its increased use can support the EU's aims of reducing greenhouse gas emissions. Information on the nature and the quality of the biomass or biofuel is important in order to support the optimization of their combustion with respect to realizing higher efficiencies and lower emissions during energy production. Three reference materials were produced by a collaborative approach among national metrology institutes and designated institutes within the scope of the EMPIR project: BIOFMET.
View Article and Find Full Text PDFPediatr Cardiol
December 2024
Division of Pediatric General, Thoracic, and Fetal Surgery, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Fetoscopic endoluminal tracheal occlusion (FETO) induces lung growth and may improve survival in congenital diaphragmatic hernia (CDH) but the effect on post-natal right (RV) and left (LV) ventricular size and cardiac function is unknown. Quantitative measures of heart size and function including tricuspid annular plane systolic excursion Z-score (TAPSEZ), RV fractional area change (RVFAC), RV global longitudinal and free wall strain (RVGLS, RVFWS), RV/LV ratio, LV eccentricity index (LVEI), and LV M-mode diastolic and systolic Z-scores (LVIDDZ, LVIDSZ) were compared between FETO and control patients on first post-natal echocardiogram, prior to and post CDH repair, and on last available echocardiogram using non-parametric Wilcoxon rank-sum test in a single-center, retrospective cohort study. Linear regression models evaluated change over time, adjusting for clustering and interaction of echocardiogram parameters with time.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
December 2024
The Shmunis Family Anthropology Institute, Dan David Center for Human Evolution and Biohistory Research, Faculty of Medical and Health Sciences, Tel Aviv University, Tel Aviv 6997801, Israel.
Identifying communal rituals in the Paleolithic is of scientific importance, as it reflects the expression of collective identity and the maintenance of group cohesion. This study provides evidence indicating the practice of deep cave collective rituals in the Levant during the Early Upper Paleolithic (EUP) period. It is demonstrated that these gatherings occurred within a distinct ritual compound and were centered around an engraved object in the deepest part of Manot Cave, a pivotal EUP site in southwest Asia.
View Article and Find Full Text PDFJ Hazard Mater
December 2024
Unit of Research in Radiation Biology & Environmental Radioactivity (URRBER), P.G. & Research Department of Zoology, The New College (Autonomous), Affiliated to University of Madras, Chennai, Tamil Nadu 600 014, India. Electronic address:
Gamma-ray spectrometry was employed to assess the activity concentrations of primordial radionuclides (U, Th, and K) in various construction materials, including those used for building, roofing, furnishing, flooring, and plastering. The measured activity concentrations of the radionuclides ranged as follows: U (25 to 477 Bq kg), Th (below detection limit to 239 Bq kg), and K (285 to 1915 Bq kg). Based on these values, the materials were categorized in descending order of radioactivity threat as: Furnishing > Roofing > Building > Flooring > Plastering.
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