Citrus cultivars have remarkable health benefits, but only the anti-inflammatory activities of the major varieties have been studied. This study investigated the anti-inflammatory effects of various citrus cultivars and their active anti-inflammatory components. The essential oils of 21 citrus peels were extracted via hydrodistillation using a Clevenger-type apparatus, and the chemical compositions of the essential oils were analyzed. D-Limonene was the most abundant constituent. To evaluate the anti-inflammatory effects of the citrus cultivars, the gene expression levels of an inflammatory mediator and proinflammatory cytokines were investigated. Among the 21 essential oils, those extracted from C. japonica and C. maxima exhibited superior anti-inflammatory activities, being able to inhibit the expression of the inflammatory mediators and proinflammatory cytokines in lipopolysaccharide-stimulated RAW 264.7 cells. The essential oils of C. japonica and C. maxima were distinguished into seven distinct constituents, α-pinene, myrcene, D-limonene, β-ocimene, linalool, linalool oxide, and α-terpineol, compared with other essential oils. The anti-inflammatory activities of the seven single compounds significantly inhibited the levels of inflammation-related factors. In particular, α-terpineol exhibited a superior anti-inflammatory effect. This study showed that the essential oils from C. japonica and C. maxima exhibit high anti-inflammatory activity. In addition, α-terpineol is an active anti-inflammatory compound that contributes to inflammatory responses.

Citrus is one of the most popular and widely grown fruit crops in the world. However, the bioactivity of only certain species of citrus cultivars is studied. In this study, the effects of essential oils from 21 citrus cultivars on melanogenesis were investigated in an effort to identify active anti-melanogenesis constituents. The essential oils from the peels of 21 citrus cultivars obtained by hydro-distillation were analyzed using gas chromatography–mass spectrometry. Mouse melanoma B16BL6 cells were used in all assays conducted in this study. The tyrosinase activity and melanin content were determined using the lysate of α-Melanocyte-stimulated B16BL6 cells. In addition, the melanogenic gene expression was determined by quantitative reverse transcription-polymerase chain reaction. Overall, the essential oils of (Citrus unshiu X Citrus sinensis) X Citrus reticulata, Citrus reticulata, and ((Citrus unshiu X Citrus sinensis) X Citrus reticulata) X Citrus reticulata provided the best bioactivity and comprised five distinct constituents compared to other essential oils such as limonene, farnesene, β-elemene, terpinen-4-ol, and sabinene. The anti-melanogenesis activities of the five individual compounds were evaluated. Among the five essential oils, β-elemene, farnesene, and limonene showed dominating properties. The experimental results indicated that (Citrus unshiu X Citrus sinensis) X Citrus reticulata, Citrus reticulata, and ((Citrus unshiu X Citrus sinensis) X Citrus reticulata) X Citrus reticulara are potential candidates with anti-melanogenesis activity for use as cosmetics and pharmaceutical agents against skin hyperpigmentation.

Wood, as a natural material that stores carbon, is gaining increasing attention and has potential for use in interior architectural applications. Given the long indoor stay time characteristic of modern society, it is important to scientifically understand the effects of indoor wood application on the occupants. In this study, three residential buildings with an identical area and structure were constructed with different degrees of wood coverage (0%, 45%, 90%) using Larix kaempferi. Subsequently, indoor air quality (IAQ) evaluations and relative humidity measurements were conducted to assess the physical and chemical changes in each environment. The IAQ in wooden and non-wooden environments met the recommended IAQ standards established in South Korea. The results of the 8-month observation showed that, the higher the wood coverage ratio, the more the indoor humidity fluctuations were alleviated, and, in the case of the 90% wood coverage ratio condition, the humidity was maintained 5.2% lower in the summer and 10.9% higher in the winter compared to the 0% condition. To further assess the physiological responses induced by the wooden environment, the heart rate variability (HRV) was measured and compared for 26 participants exposed to each environment for two hours. In environments with a 0% and 90% degree of wood coverage, no statistically significant differences were found in the participants’ HRV indicators. But, in the group exposed to the 45% wooden environment, the results showed an increase in HRV indicators, natural logarithm of high frequency power (lnHF): 4.87 → 5.40 (p < 0.05), and standard deviation of normal-to-normal intervals (SDNN): 30.57 → 38.48 (p < 0.05), which are known indicators of parasympathetic nervous system activation.

Wood has been used as the primary material for musical instruments for a long time. The density and elastic modulus of wood are known to be important factors in determining its acoustic properties of stringed instruments. The objective of this study was to show that fungal decay processes can be applied to improve the acoustic quality of the woods. The effects of biological modification of two woods, alder and soft maple, which were treated with wood rot fungi, were evaluated in terms of density (ρ), dynamic modulus of elasticity along the wood grain (EL), acoustic constant (A), and acoustic conversion efficiency (ACE). Incubation of two woods in eight species of wood rot fungi was carried out for 4 weeks. Among the fungi, Trametes versicolor and Ceriporia lacerata significantly increases the A (33.0% and 21.0%, respectively) and ACE (50.4% and 37.6%, respectively) values of alder woods. These two strains also increased the A (51.4% and 29.1%, respectively) and ACE (42.4% and 35.3%, respectively) values of soft maple. This study showed that fungal treatment significantly altered the density and elastic modulus of wood, which ultimately influenced the factor A value and the ACE value, both of which determine sound quality.

The Journal of the Korean Wood Science and Technology (JKWST) launched in 1973 as an official publication of the Korean Society of Wood Science and Technology has been served as a core of knowledges on wood science and technology.

Building service life is a critical parameter in lifecycle assessment; however, current assessments often rely on arbitrary standards. This study analyzed the empirical service life of buildings using South Korean national building-register data, categorizing 1,419,867 records into timber, masonry, steel, and concrete structures. Service life distributions were evaluated according to regional, structural, and functional factors. The results showed that while region and building scale had minimal impact, building use significantly influenced the service life of timber, masonry, and steel. Survival analysis using Weibull and Gamma distributions estimated the empirical service life to be 58.1 years for timber, 30.8 years for masonry, 22.1 years for concrete, and 10.6 years for steel. The notably shorter service life of concrete and steel compared with timber illustrates a “demolition inversion phenomenon,” where socioeconomic factors—such as urban redevelopment—drive building demolition regardless of structural durability. While results for steel and concrete reflect current replacement cycles, the 58.1-year service life of timber aligns with international benchmarks for carbon storage. These findings highlight the urgent need to revise the current 20-year legal standard for timber structures to more accurately reflect their long-term carbon sequestration potential and promote sustainable wooden architecture in carbon-neutrality policies.