Research Articles

Sodium periodate (NaIO₄) oxidation was used as a direct method to recover soluble wood components, primarily hemicelluloses, from untreated birch and spruce biomass. Through monitoring the reaction over time and at different oxidant-to-biomass ratios, the study elucidated the relationship between periodate consumption, aldehyde formation, and polysaccharide solubilization. A rapid initial uptake of the oxidant led to aldehyde generation and the extraction of hemicellulosic fractions, mainly xylan-rich in birch and glucomannan-rich in spruce followed by a decreasing (detectable) oxidizing effect likely due to further conversions of introduced aldehydes. Fourier transform infrared and heteronuclear single quantum correlation nuclear magnetic resonance analyses confirmed structural modifications consistent with monosaccharide ring opening and further conversions of created aldehydes. Size-exclusion chromatography revealed the expected accompanying chain cleavage of the affected structures. Together, these findings demonstrate both the potential and complexity of using periodate oxidation for simultaneous extraction and functionalization of wood polysaccharides, emphasizing the need for proper optimization.

The structural behavior of natural fiber-reinforced polymer composites depends largely on the efficiency of stress transfer at the fiber–matrix interface. However, accurate determination of the interface thickness and its mechanical properties remains challenging in such materials. This study aimed to characterize the interface thickness and evaluate the elastic modulus of composites produced with virgin and recycled high-density polyethylene (HDPE) matrices. Nanoindentation was employed to determine the elastic modulus of each composite phase (wood fiber, interface, and matrix) individually, through sequential indentations performed across the wood fiber-interface-matrix regions. The mean elastic modulus values for the wood fiber, interface, and matrix in the 20/80 composite (20% wood fibers and 80% virgin HDPE) were 7.51, 6.17, and 2.26 GPa, respectively. For the recycled HDPE composite, the corresponding values were 8.16, 5.82, and 1.86 GPa. The mean interface thickness was 2.5 µm in the virgin-matrix composite and 0.63 µm in the recycled-matrix composite. These results demonstrate that the recycling of the polymer matrix influences both the interfacial structure and the local mechanical performance of natural fiber reinforced composites.

Pneumonia caused by Streptococcus pneumoniae remains a serious threat to the elderly due to weakened immunity and limited treatment efficacy. This study investigates the antibacterial activity and therapeutic potential of Bletilla striata ethanolic extract (BSE) in a rat model of pneumococcal pneumonia. BSE demonstrated selective antibacterial activity against S. pneumoniae (MIC: 1.25 mg/mL) and significantly inhibited Sortase A (SrtA), a key bacterial virulence factor. In vivo, BSE improved body weight, reduced lung wet/dry ratios, and lowered serum ALP and LDH levels. It also diminished inflammatory cell infiltration in bronchoalveolar lavage fluid and decreased TNF-α, IL-1β, and IL-6 levels. Antioxidant markers SOD and GSH increased, while MDA levels declined. Histological analysis showed preserved lung architecture with reduced edema and cellular infiltration. Mechanistically, BSE suppressed the TLR4/NF-κB pathway. These findings indicate that BSE offers a dual benefit—direct antimicrobial action and modulation of inflammation and oxidative stress—highlighting its potential as a natural therapeutic for elderly patients with pneumonia.

Heavy metal pollution in the Düzce watershed of Türkiye was assessed and the phytoremediation potential of native aquatic plants was evaluated. The majority of heavy metals were found in water within legal limits, except for cadmium concentrations, which exceeded water quality standards; the main pollution load was accumulated in bottom sediments. Dominant wetland plants were analyzed to establish species-specific and tissue-specific metal accumulation patterns. Key species included Plantago major and Paspalum distichum with impressive copper accumulation capacity that may possibly classify them as good candidates for biomonitoring and phytoremediation applications. The results scientifically substantiate the use of local aquatic vegetation for ecological restoration efforts throughout Türkiye and similar regions as it pertains not merely to pollution mitigation but also a circular economy via the metal-accumulating plant biomass, which can serve these species afterward as sustainable resources for bioenergy production and biobased materials after phytoremediation activities. This brings forth new approaches to thinking about cleaning up an environment while recovering resources from polluted water ecosystems at the same time.

Activated carbon (AC) was prepared from Kraft lignin and was modified with four surfactants of sodium lauryl ether sulfate (SLES), dodecyl benzenesulfonic acid (LABSA), cetyltrimethylammonium bromide (CTAB) and cocoamidopropyl betaine (CAPB). The structure of modified ACs were characterized with BET, SEM and FTIR spectroscopy. Then, the effects of pH, initial concentration, adsorbent dosage, and contact time on adsorption of phenol from aqueous solutions were evaluated. The results showed that the highest percentage of adsorption and resistance to saturation is achieved using batch and continuous systems for AC/CAPB at the optimum pH of 8.0. High recovery percentage was also observed for AC/CAPB when ethanol was used as a regeneration solvent. It was also found that adsorption/desorption of phenol is a pH-dependent process. It is concluded that lignin-derived AC modified with CAPB as an amphoteric surfactant performs well in removing phenol from aqueous solution in comparison with pure AC and ACs treated with cationic and anionic surfactants.

Physical and mechanical properties were investigated for wood-based sandwich panels reinforced with basalt fiber fabric (BFF), glass fiber fabric (GFF), and jute fabric (JF). The panels consist of oriented strand board (OSB) cores and beech plywood facings, with reinforcements bonded by polyurethane adhesive. Properties analyzed included screw withdrawal strength (SWS), modulus of elasticity (MOE), density , and modulus of rupture (MOR). Results showed that reinforcement type significantly influenced panel performance. Jute fabric reinforcement yielded the highest stiffness (MOE of 1810 N/mm²) compared to unreinforced panels (1500 N/mm²). The BFF-reinforced panels exhibited the greatest bending strength (MOR of 62.17 N/mm²), while unreinforced panels had the lowest (53.4 N/mm²). All reinforced panels demonstrated improved SWS over unreinforced ones. Overall, reinforcing wood-based sandwich panels with jute fabric, GFF, or BFF exhibited enhanced density, bending strength, and connection strength. Reinforcement materials, including synthetic options such as glass and basalt fibers, offer lightweight, corrosion-resistant, and mechanically superior materials widely used in engineering. Natural fibers, such as jute, provide environmentally friendly reinforcement with benefits such as renewability and good insulation but face variability issues due to natural factors.  The BFF composites present a promising alternative with higher tensile strength and elastic modulus than GFF, making them effective reinforcements for wood-based sandwich panels.

The sustainable management of fruit waste offers both economic and environmental benefits, particularly in addressing the global energy crisis. This study explores the conversion of pomegranate peel waste (PPW) into bioethanol through acidic, enzymatic, and combined (acidic + enzymatic) hydrolysis followed by fermentation. Cellulolytic bacterial isolates Bacillus sp. CG2 and Bacillus manliponensis CA2 were used to perform enzymatic and combined hydrolysis of the PPW with cellulolytic potential of 0.27±0.011 and 0.265±0.05 IU, respectively. Enzymatic hydrolysis was performed at 50 °C with PPW, enzyme dosage, and acetate buffer for different time intervals while optimum conditions for acidic saccharified PPW were 6% H₂SO₄, 50 °C, 60 min. The combined hydrolysis approach used a 1:1 ratio of acidic and enzymatic hydrolysates, yielding maximum reducing and total sugar concentrations of 85.77±1.21 g/L and 179.18±3.42 g/L, respectively, after 96 h. Saccharomyces cerevisiae K7 and Metschnikowia cibodasensis Y34, was employed to ferment treated PPW hydrolysates. M. cibodasensis Y34 in combined hydrolysate produced the highest ethanol concentration (16.05 ± 0.66 g/L), with a fermentation efficiency of 83.8% and ethanol yield of 0.41 g/g. These findings highlighted the potential of integrated hydrolysis techniques for efficient bioethanol production from fruit waste.

Incorporation of planchettes and use of films which are capable to take part in color-forming reactions are the common methods in fabricating security paper documents. In this paper, a novel cellulose nanofiber-based (CNF) films with high performance in optical properties were developed for use in anti-counterfeiting applications. In order to enhance dyeability of CNFs with eco-friendly cationic berberine, functional modification was carried out by in-situ polymerization along with grafting approach with acrylic acid (AA-g-CNF). Grafting achievement was demonstrated with determination of grafting percentage and further characterized by FTIR spectroscopy. Tensile strength impairment of AA-g-CNF films which was accompanied with alteration of crystallinity and partially changing the structure of cellulose I to cellulose II was demonstrated by X-ray diffraction (XRD) analysis. The variations of dyeing reaction time and temperature caused to alter color strength of CNFs due to different adsorption rate of berberine. It can be concluded that exhibition of appropriate appearance characteristics such as color, transparency and color strength make the berberine-dyed CNF films as a novel anti-counterfeiting element for application like security paper documents.