Research Articles

Zoysiagrass (Zoysia japonica Steud.) is a widely planted warm-season turfgrass; however, its long winter dormancy limits broader adoption, especially in transitional and subtropical regions. Glycine betaine (GB) is known to mitigate cold stress in controlled environments, but its potential to improve chilling tolerance of zoysiagrass as measured by winter color retention under field conditions remains unclear. This study investigated the effects of fall-applied GB and nitrogen (N) on winter color and spring green-up of zoysiagrass under field conditions in a Mediterranean climate in Türkiye. Conducted from 2018 to 2020 in Antalya, the experiment tested different application levels of N (0, 2.5, and 5 g/m²) and GB (0, 0.8, and 1.6 g/m²). N applications significantly improved key parameters, such as winter color retention, turf quality, chlorophyll content, and spring green-up. The highest N (5 g/m²) extended the green period from 7 to 10 months by delaying dormancy. In contrast, GB treatments had no significant effects. Although GB showed limited effectiveness, its evaluation under field conditions provides valuable insight into its practical relevance for warm-season turf management. The limited effect may be related to application amount and application timing. Further research with a broader range of GB application rates may help uncover its full potential under chilling stress conditions.

Advancements in cross-laminated timber (CLT) applications have introduced the potential to use it as an alternative to reinforced concrete in basement construction. Understanding dimensional stability is crucial to ensure the reliability and safety of CLT in below-grade environments. An experimental CLT basement was constructed in Edmonton, Canada, and monitored over a period of two years. Field measurements were analyzed to estimate the dimensional changes and understand the deformation modes of the CLT panels resulting from changes in boundary conditions. A supporting laboratory experiment with specimens made from single pieces of dimensional lumber was conducted to establish a basis for comparing field-measured dimensional changes in CLT and determining the effects of cross-lamination on swelling and shrinkage coefficients. The average swelling and shrinkage coefficients calculated for CLT were approximately twice as large as the longitudinal and 20 times smaller than the transverse coefficients obtained from the laboratory experiments on solid wood specimens, indicating the influence of cross-lamination on these coefficients. Four deformation modes were identified based on measurements from field-installed strain gauges. The study provides new insights into the impact of water ingress on the swelling coefficient and the effects of different drying conditions on the shrinkage coefficients of CLT.

Curcuma caesia Roxb. (Zingiberaceae) is one of the endangered species in the genus Curcuma that possesses numerous beneficial bioactive compounds that are responsible for various pharmacological properties including anti-cancer, anti-asthmatic, anti-diabetic, and others. In the past few years, the number of C. caesia plants was reported to have drastically decreased due to over-harvesting activity. To conserve this species, plant tissue culture method was used as a propagation tool for the mass production of C. caesia plantlets. Hence, this study aimed to optimize the extraction of phenolics content and antioxidant activities using response surface methodology. In this study, central composite design (CCD) was used to investigate the effects of three independent variables, namely solvent-solid ratio (mL/g), methanol concentration (%), and extraction temperature (°C), on phenolics content and antioxidant activities. Based on the results, the optimal extraction condition was achieved using 54.02 mL/g solvent-solid ratio, 70% methanol concentration, and 70 °C of extraction temperature.

Southern pine samples were vacuum-pressure impregnated with nano-SiO₂ with Nano-SiO₂ based on different specific surface areas (60, 150, 200, 380m².g^-1) and impregnated with alkaline copper quat type D (ACQ-D) preservatives or ACQ-D preservatives modified with emulsified wax. The treated wood was exposed outdoors for one year. The effects of emulsified wax and different conditions of nano-SiO₂ on the color change, wettability, and thermal stability of the treated wood were evaluated by colorimeter, contact angle tester, and thermogravimetry (TG). The results showed that nano-SiO₂ modification was helpful to keep the surface color stable for ACQ-D treated wood, while the effect of emulsified wax and the specific area of nano-SiO₂ on the color stability was slight. The static contact angles were increased after outdoor exposure with nano-SiO₂ and/or emulsified wax because of the reduction of the free hydroxyl groups, especially for nano-SiO₂ with smaller specific surface area. The thermal stability of ACQ-D treated wood could be increased to different degrees depending on the type of nano-SiO₂ and whether emulsified wax were present in the treated wood, although the emulsified wax only played an auxiliary effect on the thermal stability of the treated wood.

This study addressed the efficiency of different biochars in Cd immobilization in soil. An acidic sandy loam paddy contaminated with Cd was selected for the field trial, which was continued for three rice-growing seasons. Rice straw biochar (BR), wheat straw biochar (BW), and maize straw biochar (BM) were pyrolysed as pellets at 450 °C and applied at 0 t/ha (BC0), 10 t/ha (BR1/BW1/BM1), and 20 t/ha (BR2/BW2/BM2). Compared to BC0, BR and BW were more effective in decreasing Cd accumulation in rice grains, and BR2 achieved the highest reduction, averaging 43.4% over three rice seasons. The Cd contents in rice roots with BR2 treatment decreased by 15.2 to 55.3% compared with BC0. The bioconcentration factors for grains (BCF_Grain), shoots (BCF_Shoot), and (BCF_Root) of BR2 treatment were averagely decreased by 53.3%, 27.4%, and 19.0% over BC0, respectively. There was a negative correlation between soil CaCl₂-Cd and soil pH. FTIR analysis demonstrated that Cd complexed with SiO₂ on aged BR2 particles. During the natural aging process, BR2 significantly and sustainably inhibited rice uptake Cd through co-deposition. Therefore, the BR was judged to be an effective soil amendment with high Si content and alkalinity for Cd immobilization in paddy soil.

The bending behavior of four key timber species (Fraxinus chinensis, teak, rubberwood, and Pinus yunnanensis) was evaluated under hydrothermal-chemical treatments. Controlled experiments at varying moisture contents (20 to 60%), temperatures (100 to 140 °C), and treatment durations (4 to 8 h) revealed that bending strength and elastic modulus decreased by 18 to 32% with increased moisture and temperature, stabilizing beyond critical thresholds (40% moisture, 120 °C). Among the treatments, the compound lye (40% ammonia + 5% ethylenediamine with surfactants) outperformed ammonia and water treatments, achieving the highest bending deformation height-to-radius ratio of 0.102. X-ray diffraction and Fourier-transform infrared spectroscopy analyses confirmed selective lignin degradation and reduced inter-fiber friction. These findings suggest that this method offers a promising, cost-effective approach for improving the structural integrity of curved wood components.

Diverse metabolites of plants exhibit various biological activities. Supercritical fluid extraction (SFE) was applied at various temperatures (40, 60, and 80 ºC) to extract Duranta erecta fruits. Maximum yield of extract (0.456 g) was obtained at 60 ºC; besides, at this temperature the release of gallic acid, chlorogenic acid, methyl gallate, rutin, naringenin, rosmarinic acid, daidzein, quercetin, and kaempferol were promoted in high concentrations of 3510, 277, 326, 571, 7460, 1060, 31000, 7770, and 103 µg/mL, respectively. Moreover, S. aureus, S. typhi, B. subtilis, E. coli, and C. albicans, were inhibited with highest inhibition zones such as 28±0.1, 27±0.2, 30±0.1, 25±0.1, and 30±0.2 mm, respectively at 60 ºC than that at other temperatures of the SFE. Low quantities of minimum inhibitory and minimum bactericidal concentrations of the extract were recorded at 60 ºC. Ultrastructural changes were observed in the exposed B. subtilis to D. erecta fruits extract at 60 and 80 ºC including irregular, and rupture of cell wall. Antioxidant potential of D. erecta fruits extract via DPPH was recorded with promising IC₅₀ value of 9.66 µg/mL. Moreover, FRAP antioxidant activity was confirmed with 355 equivalent (AAE) µg/mg at 60 ºC. The fruits extract from D. erecta at 60 ºC of SFE conditions reflected excellent wound healing property.

This study was conducted to address the urgent need for identifying drought-tolerant varieties of Pinus sylvestris L. (Scotch pine) in response to the increasing impact of global climate change on forest ecosystems. The aim was to evaluate the physiological and biochemical responses of Scotch pine provenances grown in the Lakes Region of Türkiye in terms of photosynthetic gas exchange and selected stress-related chemical traits. Samples from different origins were analyzed to assess parameters such as adaptation to drought stress, water use efficiency, stomatal conductance, and photosynthesis rate. The data, obtained from long-term provenance trials established in 2000 in Aydoğmuş (Isparta) and Kemer (Burdur), revealed how these traits vary depending on origin and site conditions. Among the provenances, Çatacık, Akyazı, and Mesudiye displayed higher photosynthesis rates, stomatal conductance, and transpiration. Additionally, the accumulation of proline and hydrogen peroxide appeared to play a key role in drought adaptation, with Çatacık and Akyazı showing better performance under arid conditions. The findings provide valuable insights for selecting appropriate Scotch pine provenances for afforestation in arid and semiarid environments and contribute to the development of climate-resilient forest management strategies.

The effect of Callicarpa kwangtungensis Chun (CKC) was evaluated in Pilocarpine (P350, 350 mg/kg)-induced epilepsy in mice. The behavioral patterns of experimental mice were investigated by the number of convulsed animals, survivors, after P350-induced convulsions, latency to 1^st convulsion, and latency to death. The administration of CNC extended both the latency to the first convulsion and the time to death in a dose-dependent manner. The role of receptors in the anti-convulsive action of CNC was investigated using a combination of atropine (cholinergic receptor antagonist), memantine (NMDA-type glutamate receptors blocker), and diazepam (GABA agonist). The CNC increased latency to the 1^st convulsion and to death in diazepam combination while there was no significant alteration in other two combination, suggesting that CNC anticonvulsive action is mediated through the GABA receptor. The CNC increased the striatal concentration of dopamine (DA) and DOPAC in the brain, suggesting that it prevents convulsion in animals by inhibiting DA metabolism. The CNC improved the antioxidant status of brain as evidenced by decrease in level of TABARS, carbonyl protein, and nitric oxide, whereas the levels of sulfhydryl protein, SOD, and CAT were increased. Thus, the anti-epileptic potential of Callicarpa kwangtungensis Chun is accomplished by modulating GABAergic and DAergic transmission.

Five-layer cross-laminated timber (CLT) beams made from 17-mm thick lumber pieces were produced using wood from Scots pine (Pinus sylvestris L.), Uludağ fir (Abies bornmüelleriana Mattf.), and oak (Quercus petraea L.). The outer layers consisted of Scots pine and oak, while the intermediate layers included Scots pine and fir wood. During the layer formation phase in the side-by-side joining press and in the CLT beam formation phase with layers stacked at 90°, polyvinyl acetate (PVAc) and polyurethane (PUR) adhesives were used. After conditioning the CLT beams at 20 °C and 65% relative humidity, their dry density values and results from a four-point bending test perpendicular to the adhesive line, including max load, displacement at max load, stiffness, max displacement, and energy dissipation capacity, were evaluated and compared with those obtained using ABAQUS finite element software. The results revealed that timber species, adhesive type, and perforation significantly influenced the mechanical behavior of CLT beams, with oak-based specimens generally outperforming fir and pine in load-bearing capacity. The findings contribute valuable insights into the optimization of CLT beam design for structural applications.