Influence of residual palm oil in pressed mesocarp fiber on extracellular enzyme secretion and morphological characteristics of fungal biomass during solid-state fermentation

Oil palm mesocarp fiber, a lignocellulosic by-product of the crude palm oil extraction process, contains residual oil within its fibrous matrix. While mesocarp fiber from oil-bearing fruits has gained attention as a carbon source in solid-state fermentation, the role of residual oil in microbial adaptation and enzyme secretion remains unclear. This study examines the effect of residual oil on enzyme production by comparing oily mesocarp fiber (OMF) and deoiled mesocarp fiber (DeMF) as solid matrices for solid-state fermentation using Trichoderma reesei RUT-C30. Lipase and (hemi)cellulolytic enzyme activities were assessed under varying moisture content and pH conditions alongside fungal biomass morphology. OMF promoted higher lipase production, reaching 24.79 IU per gram dry solid (GDS) at a 1:3.5 solid-to-liquid ratio (SLR). In comparison, DeMF enhanced (hemi)cellulolytic enzyme activity, with CMCase peaking at a 1:1.5 SLR, while xylanase and β-glucosidase activity peaking at pH 7.5 under buffered conditions. Furthermore, residual oil exhibited an antifungal effect at pH 7.5, reducing fungal biomass and extracellular enzyme yields. These findings provide valuable insights into the role of residual oil in solid-state fermentation, highlighting its dual function as a lipase inducer and a potential inhibitor under certain conditions

Effect of dibenzyl disulphide on partial discharge characteristics in mineral oil–impregnated cellulose pressboard

This study investigates the partial discharge (PD) characteristics of mineral oil-impregnated cellulose pressboard induced by dibenzyl disulphide (DBDS). Mineral oils with DBDS concentrations of 0 ppm, 1,000 ppm, 5,000 ppm, and 10,000 ppm were thermally aged at 150 °C for 5 days. PD measurements, which included apparent charge, PD repetition rate, and partial discharge inception voltage (PDIV), were performed using needle–plane and plane–plane electrode configurations at 10 mm and 20 mm gap distances. Phase–resolved partial discharge (PRPD) patterns were analysed to assess discharge intensity and phase distribution. Results show that under the needle–plane configuration, PDIV increases by up to 44.3% in pressboards aged with 5000 ppm DBDS at both gap distances. In contrast, under the plane–plane configuration, PDIV of pressboards aged in 1,000 ppm DBDS at both gap distances decreases by up to 56%. PRPD analysis reveals a transition from compact, peak-centred discharges (Type 3) to broad and scattered patterns (Type 6) that indicates progressive surface degradation driven by DBDS contamination

Forensic differentiation of Malaysia biodiesel and illicit fuels using GC-FID and GC–MS techniques

Illegal, unreported, and unregulated (IUU) fishing poses a serious threat to marine biodiversity and economic stability, particularly in coastal nations like Malaysia, where the smuggling of government-subsidized fuel is often linked to IUU activities. This study presents a forensic approach using gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC–MS) to chemically characterize and differentiate between legally distributed Malaysia biodiesel blends (B7 and B10) and illicit fuels seized from vessels involved in maritime violations. A total of 29 fuel samples from detained vessels in Kuala Terengganu and Mersing were compared with 20 reference biodiesel samples from major Malaysia fuel brands. GC-FID revealed hydrocarbon ranges of C10–C29 in biodiesel, with additional FAME peaks near n-C19 and n-C21, while IUU fuels showed wider ranges (C10–C33) but no FAMEs. GC–MS confirmed key biomarkers—bicyclic sesquiterpanes, adamantanes, isoprenoids, PAHs, and FAMEs—highlighting methyl palmitate (C16:0) and methyl oleate (C18:1) as diagnostic of biodiesel. Multivariate analyses (HCA and PCA) further separated B7, B10 and IUU samples, with subtle differences between B7 and B10 attributed to feedstock or blending variation. This study is the first to combine GC-FID, GC–MS, and chemometric analyses (PCA and HCA) into a forensic framework for differentiating Malaysian biodiesel blends (B7, B10) from illicit maritime fuels. By leveraging diagnostic biomarkers beyond FAMEs, the approach enables robust classification and provenance analysis. This integrated strategy provides evidential value for maritime law enforcement, advancing fuel forensics in Southeast Asia. These findings display the utility of chromatographic techniques in maritime law enforcement, enabling fuel source attribution and supporting legal proceedings. Despite promising results, limitations such as restricted sample coverage, lack of replicate analysis, and absence of a chromatographic fingerprint database highlight the need for further validation. The study advocates for the development of an integrated GC-based forensic framework to enhance Malaysia's capability in combatting fuel smuggling and IUU fishing activities

Application of linear programming in the development of complementary feeding recommendations: a systematic review

The use of linear programming (LP) to develop complementary food recommendations (CFRs) is gaining interest due to its ability to produce low-cost population-specific food-based recommendations (FBRs). This review aimed to identify the components of LP models commonly used in developing CFRs and summarize the evidence on the use of LP-developed CFRs as an intervention strategy. The databases PubMed, Science Direct, Scopus, Cochrane Library, Web of Science, and Google Scholar were searched for relevant articles. LP was used in twenty-six studies to develop CFRs for young children and in three studies LP-developed CFRs were applied to improving complementary feeding. The objective function varied across studies, such as to maximize nutrient content, minimize cost, minimize deviation between observed and modeled diets, and minimize multiple nutrient deficiencies. All studies applied nutritional and acceptability constraints. Individual intervention studies showed that LP-developed CFRs can improve children’s nutrient intake and feeding practices, as well as mother’s nutrition knowledge. Various applications of LP have been used to develop optimal infant diets. However, LP-developed CFRs as a nutrition intervention strategy have been used in only a few studies. Further robust research is needed to test LP-developed CFRs

Spa social responsibility as a quality signal: building customer loyalty through ethical and sustainable practices

Drawing on signaling theory and the Stimulus-Organism-Response (S-O-R) framework, the research examines how specific dimensions of social responsibility, such as eco-friendly products, sustainable design, waste management, and certification standards shape consumer perceptions. Using Generalized Structured Component Analysis with Measurement Errors (GSCAM) together with necessary condition analysis (NCA), the study identifies both sufficient and necessary spa social responsibility components that drive attitudinal and behavioral outcomes. Key findings reveal that certain sustainability practices are essential for forming positive attitudes, which, in turn, are critical for customer loyalty. Conversely, promotional logistics and cultural sustainability were found to be less influential or insufficient on their own. The results provide a comprehensive theoretical contribution to socially responsible signaling and offer practical insights for spa managers seeking to enhance competitiveness through authentic and strategically communicated social responsibility initiatives

A novel two-derivative multistep collocation method with fitting-techniques with application to Duffing problem

The general k-step fifth-order two-derivative linear multistep collocation method (TDLMM5) using collocation technique with Gegenbauer polynomial as basis function is derived for direct integrating second-order ordinary differential equation in the form u″(t)=f(t,u(t)) with periodic solution. Fifth-order two-derivative linear multistep method with various collocation points and off-set points is developed using collocation and interpolation approach. Order, stability, consistency and convergence of TDLMM5 are analyzed and discussed. Then, trigonometrically-fitting technique is adapted into TDLMM5 by setting u(t) as the linear combination of the functions {sin(λt),cos(λt)},λ∈R and turn the coefficients of TDLMM5 into frequency-dependent. Numerical experiment is conducted to verify the proposed method is superior compared to other existing methods in the literature with similar order. Additionally, the trigonometrically-fitted TDLMM5, denoted as TFTDLMM5, is applied to the well-known damped and driven oscillator problem, known as the Duffing problem. The outcome demonstrates that the proposed method is still successful in modeling this real-world application problem

Fatty acid profile and bio-preservative efficacy of lactic acid bacteria postbiotics for improving microbiological safety in broiler meat

Postbiotics derived from lactic acid bacteria (LAB) are promising natural antimicrobials due to their bioactive metabolites. This study evaluated their chemical composition and antimicrobial efficacy both in vitro and in vacuum-packaged broiler breast meat inoculated with meatborne pathogens during 10 days of storage. Postbiotics from Lactiplantibacillus plantarum (LP), Lactobacillus acidophilus (LA), and Lacticaseibacillus rhamnosus GG (LGG) were prepared by culturing LAB in MRS broth, followed by centrifugation and filtration, and subjected to GC-MS analysis. Neutralized postbiotics were used to obtain bacteriocin-like substances (BLS). Both postbiotics and BLS were tested against Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, and Bacillus cereus in an in vitro assay, while postbiotics were applied to the meat in a 1:5 ratio in the meat model. Principal component analysis demonstrated distinct strain-specific fatty acid profiles, with oleic acid driving separation among LAB-postbiotics. In vitro, BLS achieved peak inhibition within 4–12 h, reducing OD600nm of E. coli and Salm. Typhimurium by 40–50 % at 12 h, whereas postbiotics provided stronger early suppression, lowering these pathogens by 80–86 %, with the highest activity by LGG-postbiotics (86 %). In the model, untreated samples exhibited an increase in total mesophilic aerobic bacteria, Gram-negative, and Gram-positive pathogens from 6.91 to 9.26 log10 CFU/g, whereas postbiotic treatments reduced counts to 1.06–3.64, 1.41–4.36, and 0.93–3.30 log10 CFU/g, respectively, with higher concentrations more effective. LGG-postbiotics reduced Salm. Typhimurium in broiler meat compared to LA and LP. In conclusion, LAB-derived postbiotics, particularly LGG, could be used as natural preservative agents to improve microbiological safety in the broiler industry

The effect of temperature and storage time off semen samples on the spermatozoa deoxyribonucleic acid (DNA) fragmentation

DNA fragmentation analysis is essential for evaluating sperm DNA integrity, which affects fertilization, embryo development, and pregnancy outcomes. However, many Indonesian laboratories lack access to this testing due to limited availability of commercial kits. This study aimed to assess the effects of storage temperature and duration on sperm DNA fragmentation by comparing fresh semen samples with those stored under various conditions. This post-test-only experimental study was conducted at the Biomedical Laboratory, Faculty of Medicine, Universitas Airlangga, Surabaya, from March to October 2023. Semen samples were collected from ten normozoospermic men aged 20-35 years. The samples were divided into four groups: fresh samples (P1), samples stored in a cool box (7-8 °C) for 3 hours (P2), and samples stored in a freezer at-16 °C for 3 days (P3) and 7 days (P4). DNA fragmentation was assessed using the Sperm Chromatin Dispersion (SCD) method. The Shapiro-Wilk test was used for normality. Depending on data distribution, paired t-tests or Wilcoxon signed-rank tests were applied. No significant differences were found in DNA fragmentation index between fresh and stored samples: P1 vs. P2 (p = 0.257), P1 vs. P3 (p = 0.705), and P1 vs. P4 (p = 0.102), indicating DNA stability. Sperm DNA fragmentation remains stable under the tested storage conditions. Semen samples can be stored at 7-8 °C for 3 hours or frozen at-16 °C for up to 7 days without compromising DNA integrity

Enhancing aviation sustainability: bimetallic Ni–Co catalysts for bio-jet fuel from palm kernel oil

The production of bio-jet fuel from renewable sources such as palm kernel oil (PKO) biomass has been extensively been studied for the production of transportation fuel due to its availability. Hence, this study was focused on the production of bio-jet fuel (BJF; C8-C16) derived from PKO via catalytic deoxygenation (DO) reaction under H2-free environment over Nix-Cox supported on magnetite (Fe3O4) catalyst. The Ni and Co concentrations have been kept within 0.5–0.75 wt% to optimize the synergistic interaction between the metals and the support. The result indicated that Ni0.5-Co0.5/Fe3O4 catalyst exhibited high surface area (156.75 m2g−1) with weak (437.1 μmol/g) + strong (14601.0 μmol/g) acidic sites. In a preliminary PKO catalytic DO study conducted at 350℃ for 3 h using a 5 wt% catalyst loading under an inert N2 atmosphere, the results revealed that the Ni0.5-Co0.5/Fe3O4 catalyst exhibited higher DO activity, achieving approximately 91 % hydrocarbon selectivity. The majority of the product was in the BJF (C8-C16) fraction, accounting for 95 %. The data also showed that the Ni0.5-Co0.5/Fe3O4 catalyst was more selective towards BJF, with a selectivity value of 77 %, the highest observed for the C11 carbon chain. Based on the kinetic and deactivation study of the Ni0.5-Co0.5/Fe3O4 catalyst over a 500mins DO reaction, the results revealed that the primary cause of catalyst deactivation was coking activity. It also appeared that a higher DO temperature (350℃) positively affected coking activity. Interestingly, a longer reaction time at a lower DO temperature mitigated coking activity, with coke deposition reaching approximately 5 wt%. The Ni0.5-Co0.5/Fe3O4 catalyst demonstrates significant commercial viability for industrial bio-jet fuel production owing to its exceptional deoxygenation efficacy and adequate coking resistance

Research on strain-responsive Arsenene/SnSeS heterojunction for digital media technology: a first-principles calculations

The rapid advancement of artificial intelligence and big data has led to a significant increase in global demand for data storage and information transmission, raising concerns regarding capacity and efficiency. Consequently, the development of novel stimulus-responsive materials has emerged as a critical area of research. This study presents the construction of a new Arsenene/SnSeS heterojunction and employs first-principles methods to manipulate its electronic and optical properties through the application of strain. The computational findings reveal that the Arsenene/SnSeS heterojunction demonstrates remarkable stability and favorable electronic characteristics. Notably, the bandgap of the heterojunction is smaller than that of both the Arsenene monolayer and the SnSeS monolayer, thereby facilitating enhanced charge transfer. Furthermore, the electronic properties of the Arsenene/SnSeS heterojunction can be effectively modulated by strain, which induces redshift or blueshift in the optical absorption peaks. These research outcomes offer valuable insights for the advancement of intelligent stimulus-responsive materials