Search Results (193)

Restricting the use of chemical pesticides in forestry requires the search for alternative solutions. These could be volatile organic compounds produced by three investigated species of bacteria (Bacillus amyloliquefaciens (ex Fukumoto) Priest, B. subtilis (Ehrenberg) Cohn and B. thuringiensis Berliner), which inhibit the growth of the pathogen F. oxysporum Schltdl. emend. Snyder & Hansen in forest nurseries. The highest inhibition of fungal growth (70%) was observed with B. amyloliquefaciens after 24 h of antagonism test, which had a higher content of carbonyl compounds (46.83 ± 8.41%) than B. subtilis (41.50 ± 6.45%) or B. thuringiensis (34.62 ± 4.77%). Only in the volatile emissions of B. amyloliquefaciens were 3-hydroxybutan-2-one, undecan-2-one, dodecan-5-one and tetradecan-5-one found. In contrast, the main components of the volatile emissions of F. oxysporum were chlorinated derivatives of benzaldehyde (e.g., 3,5-dichloro-4-methoxybenzaldehyde) and chlorinated derivatives of benzene (e.g., 1,4-dichloro-2,5-dimethoxybenzene), as well as carbonyl compounds (e.g., benzaldehyde) and alcohols (e.g., benzyl alcohol). Further compounds were found in the interactions between B. amyloliquefaciens and F. oxysporum (e.g., $\alpha$-cubebene, linalool, undecan-2-ol, decan-2-one and 2,6-dichloroanisole). Specific substances were found for B. amyloliquefaciens (limonene, nonan-2-ol, phenethyl alcohol, heptan-2-one and tridecan-2-one) and for F. oxysporum (propan-1-ol, propan-2-ol, heptan-2-one and tridecan-2-one). The amounts of volatile chemical compounds found in B. amyloliquefaciens or in the bacterium–fungus interaction can be used for further research to limit the pathogenic fungus. In the future, one should focus on the compounds that were found exclusively in interactions and whose content was higher than in isolated bacteria. In order to conquer an ecological niche, bacteria increase the production of secondary metabolites, including specific chemical compounds. The results presented are a prerequisite for creating an alternative solution or supplementing the currently used methods of plant protection against F. oxysporum. Understanding and applying the volatile organic compounds produced by bacteria can complement chemical plant protection against the pathogen, especially in greenhouses or tunnels where plants grow in conditions that favour fungal growth. Full article

Background: Insulin resistance (IR) is an underlying pathophysiology for type 2 diabetes (T2D). The Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) is the simplest method for evaluating IR. At the same time, volatile organic compounds (VOCs) detected in human respiration can be correlated with specific diseases. To date, machine learning (Mach-L) has yet to be used to examine potential relationships between VOCs and IR. The present study has two aims: (1) to identify the VOCs most relevant to HOMA-IR, and (2) to use Shapley addictive explanation (SHAP) to determine the impacts of the distributions and directions of each feature in Taiwanese women. Methods: A total of 1432 Taiwanese women between the ages of 19 and 84 years were enrolled, and 344 VOCs were measured. Traditional multiple linear regression (MLR) was used as a benchmark for comparison, applying three Mach-L methods. Finally, SHAP was used to evaluate the directions of impacts of the features on HOMA-IR. Results: Six VOCs were identified as important: dimethylfuran, propanamine, aniline, butoxyethanol, and isopropyltoluene, in order from most to least important. SHAP found that dimethylfuran, isopropyltoluene, and dodecane were positively correlated to HOMA-IR, while butoxyethanol, aniline, and propanamine were negatively correlated. Conclusions: Using three different Mach-L methods, six VOCs were selected to be related to IR in Taiwanese women. According to their importance, dimethylfuran, propanamine, aniline, butoxyethanol, and isopropyltoluene could be used to help diagnose HOMA-IR. Furthermore, by using SHAP, dimethylfuran, isopropyltoluene, and dodecane had a positive and the other three had a negative influence. Full article

Thrips can be attracted or repelled by volatiles from different host plant species. Houttuynia cordata is a common plant species with a strong, offensive smell, and few pests have been detected on this plant. Here, the olfactory responses of Frankliniella occidentalis to H. cordata volatiles were tested using electroantennography (EAG) and behavioral bioassays in different types of olfactometers, and the behavioral responses of Orius similis, a natural enemy of F. occidentalis, to the related main volatile compounds were also evaluated. Y-tube olfactometer bioassays showed that F. occidentalis performed negative responses to H. cordata volatiles. Decanal (47.21%), 1-decanol (11.02%), dodecanal (7.13%), β-myrcene (5.12%), and decanoyl acetaldehyde (3.76%) were the more abundant components in the H. cordata volatile profile in gas chromatography–mass spectrometry analysis. EAG recordings showed that the antennae of female thrips could perceive these five compounds at a wide range of concentrations. In six-arm olfactometer bioassays, F. occidentalis exhibited negative responses to decanal, dodecanal, and decanoyl acetaldehyde at various doses but performed positive responses to 1-decanol and β-myrcene at certain doses. Furthermore, decanal, dodecanal, and decanoyl acetaldehyde at all concentrations showed no significant influences on the behavioral responses of O. similis. According to the results above, H. cordata can be a repellent plant species to F. occidentalis, and decanal, dodecanal, and decanoyl acetaldehyde show great potential for development as repellents for the control of F. occidentalis. In short, our results suggest that an integrated pest management system combining H. cordata-derived biopesticides with releases of the predator O. similis could effectively control F. occidentalis. Full article

To address the design and optimization of the ignition system for the microgravity single-droplet combustion experiment module within the Combustion Science Experimental System (CSES) aboard the Chinese Space Station (CSS), it is essential to first determine the ignition temperatures required for typical liquid fuel droplets. In this study, ignition experiments were conducted on droplets of three representative hydrocarbon fuels—ethanol, n-heptane, and n-dodecane—in static air at high temperatures ranging from 760 K to 1100 K. The experimental results show that the initial droplet diameter is inversely correlated with the ambient temperature at which ignition occurs. Subsequently, based on Frank-Kamenetskii’s analytical method and combined with experimental data, a semi-empirical predictive model for droplet ignition temperatures in a normal-gravity environment was derived. Building upon this, and considering the characteristics of the microgravity environment, an appropriate empirical formula was applied to refine the model, resulting in a predictive model for droplet ignition temperatures in the microgravity environment. Furthermore, by comparing the experimental data and the observed phenomena from existing microgravity experiments, this semi-empirical predictive model used in the microgravity environment effectively reflects the trend of droplet ignition temperature variations. Full article

This paper investigates the influence of ventilation conditions, including oxidizer flow speed and oxygen concentration, on major species composition in favor of estimating a risk of flame acceleration at reduced gravity. A two-step chemical reaction for gas phase and a soot formation model based on laminar smoke point are used. To calculate thermal radiation from flame, a discrete-ordinates method is coupled with a non-grey model by taking into account the radiative properties of CO, CO₂, H₂O and soot. The predictions provide further insights into the intimate coupling of fuel types, such as heptane and dodecane, with burning rate, flame structure and toxic emissions as a consequence of changes in ventilation conditions such as oxidizer flow velocity and oxygen concentration. From a boundary-layer microgravity flame, the CO₂ to CO ratio is less than 3, and the unburnt hydrocarbons C_mH_n to CO ratio is less than 2, with a concentration of unburnt fuel that exceeds the Lower Flammability Limit. This finding on the production of unburnt species is contrasted to the case of a buoyancy-controlled flame at Earth gravity. Full article

Porous materials are used in many important applications, such as separation technologies, catalysis, and chromatography. They may be obtained from various monomers via diverse polymerization techniques and a wide range of synthesis parameters. The study is devoted to the synthesis and characterization of crosslinked porous polymeric spheres containing pyrrolidone subunits. To achieve this goal, two methods were applied: direct synthesis from N-vinyl-2-pyrrolidone (NVP) with ethylene glycol dimethacrylate (EGDMA) and via a modification reaction of porous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) with pyrrolidone (P). The polymerization was carried out with the use of different molar ratios of the monomers. In order to obtain highly porous materials, pore-forming diluents (toluene, dodecane, and dodecan-1-ol) were used. The synthesized copolymers were characterized using size distribution analysis, ATR-FTIR spectroscopy, scanning electron microscopy, thermogravimetry, and inverse gas chromatography. Determined by the nitrogen adsorption/desorption method, the specific surface area was in the range of 55–468 m²/g. The good thermal properties of the poly(VP-co-EGDMA) copolymers allowed them to be applied as the stationary phase in gas chromatography. Full article

This study develops iridium (Ir)-based catalysts for the hydrogenation of dodecanoic acid, a medium-chain fatty acid abundant in palm kernel and coconut oils, for producing fatty alcohols and alkanes. Among various supports such as AlOOH, SiO₂, TiO₂, Nb₂O₅, MoO₃, Ta₂O₅, ZrO₂, and WO₃ for 7.5 wt% Ir loading, an Ir-impregnated Nb₂O₅ (Ir/Nb₂O₅) catalyst demonstrated remarkable performance with 100% conversion and a high dodecanol yield (89.1%) under mild conditions (170 °C, 4.0 MPa H₂), while at higher temperatures and pressures (200 °C, 8.0 MPa H₂), Ir-impregnated MoO₃ (Ir/MoO₃) produced dodecane as the main product with a yield of 90.7%. These findings can tailor product selectivity toward desired bio-based chemicals and fuels, offering sustainable pathways for fatty acid hydrogenation by optimizing catalyst supports and reaction conditions in the Ir-based catalyst. Full article

The influence of boiling time on the persistent changes in the surface color, water content and distribution, protein secondary structure, and the concentration of volatile compounds in beef were studied, in order to obtain quality short-term boiled beef slices. The results show that the water content of beef samples significantly decreased and migration occurred between the high-freedom water and the low-freedom water. On average, boiling for 1 min was a key point in the changes of color parameters (L*, a*, b*, w, ΔE, and BI) and partial protein secondary structure because of the change in the ambient temperature around beef. In six samples, 29 volatile compounds were confirmed by GC–MS, and 13 compounds were regarded as the potential key volatile compounds, including 1-heptanol, 1-octen-3-ol, octanal, hexanal, decanal, heptanal, nonanal, (E, E)-2,4-decadienal, (E, E)-2,4-nonadienal, dodecanal, (E)-2-undecenal, 2,3-octanedione, and 2-pentylfuran. The color, water, and protein secondary structure were closely correlated with some potential key volatile compounds. The results could be used to guide the consumers to better grasp the quality of hot-pot meat during gatherings and have a comfortable consumer experience. Full article

Retinoids, including retinol, retinal, and retinoic acid, are a group of vitamin A derivatives with skin-improving effects. Retinoic acid is highly effective for skin anti-aging but can cause irritation, requiring a prescription. Retinol, a less irritating alternative, needs conversion to retinal and then retinoic acid in the skin, whereas direct absorption of retinal enhances efficacy by bypassing this conversion process. This study aimed to produce retinal through precision fermentation using metabolically engineered Saccharomyces cerevisiae. The introduction of heterologous retinal biosynthetic genes and overexpression of the truncated HMG-CoA reductase (tHMG1) and acetyl-CoA acetyltransferase (ERG10) genes in the mevalonate (MVA) pathway increased retinal production up to 10.2 mg/L. At the same time, ethanol was produced as a major byproduct in S. cerevisiae. To address this, a pyruvate decarboxylase (Pdc)-deficient S. cerevisiae strain, incapable of producing ethanol, was employed. Overexpression of ERG10 and tHMG1 in the Pdc-deficient S. cerevisiae harboring the retinal biosynthetic plasmids achieved a retinal production up to 117.4 mg/L in the dodecane layer without ethanol through a two-phase in situ fermentation and extraction. This study demonstrates that eliminating pyruvate decarboxylase activity effectively redirects carbon flux toward retinal biosynthesis in the recombinant S. cerevisiae, offering a promising approach for sustainable retinal production through precision fermentation. Full article

This study aimed to thoroughly investigate the quality differences and influencing factors of Dahongpao tea of different grades. Through sensory evaluation, electronic nose analysis, electronic tongue analysis, biochemical component analysis, and HS-SPME-GC-MS, the taste and aroma characteristics of Dahongpao samples of different grades (superfine, first, and second grades) were comprehensively studied. The results showed that there were significant differences in sensory quality, aroma components, and taste components among Dahongpao of different grades. Superfine Dahongpao has a rich aroma and mellow taste, containing a higher content of esters and aromatic hydrocarbons such as benzaldehyde (2-hydroxy-5-methoxy), hexyl benzoate, and cyclohexanecarboxylic acid 2,3-dichlorophenyl ester, which endow it with fruity, floral, and woody characteristics. In contrast, first- and second-grade Dahongpao contain more alkanes, pyrazines, and furans such as benzene (1-ethyl-1-propenyl), dodecane (2,6,10-trimethyl), and pyrazine (2,6-dimethyl), which impart floral, roasted, and nutty flavors. Moreover, superfine Dahongpao has a more bitter and astringent taste, but the bitterness and astringency dissipate more quickly, while the taste of first- and second-grade Dahongpao is relatively bland. These differences provide a scientific basis for the grade classification of Dahongpao tea and offer references for improving tea quality and standardized production. Full article

To investigate the specific performance enhancement of oilfield surfactants by using sodium p-aminobenzenesulfonate as a connecting group, cationic surfactant N,N-dimethyl-N-(oxiran-2-ylmethyl)dodecan-1-aminium (DDPA) and zwitterionic gemini surfactant sodium 4-[bis(3-(dodecyldimethylamino)-2-hydroxypropyl)amino]benzenesulfonate (DDBS) were synthesized. The oil recovery performance of these surfactants was compared, revealing that DDBS outperforms DDPA in thermal stability, wettability, adsorption, and resistance to temperature and salinity variations, as well as surface/interface activity, except for emulsification. Core flooding experiments, simulating the conditions of the Xinjiang oilfield, demonstrated that DDBS can achieve the same enhanced oil recovery effect at a concentration that is 1/15 of that of DDPA. Compared with water, DDBS and DDPA can incrementally enhance recovery rates by 7.9% and 8.5%. Furthermore, the synergistic formulation of DDBS with sodium dodecylbenzenesulfonate (SDS) significantly optimized performance, achieving a reduction in interfacial tension to 0.0301 mN m⁻¹. This study provides a research and data foundation for the application of new surfactants in petroleum extraction. Full article

Since the 1960s, theorists have claimed that the electroweak force, which unifies parity-conserving electromagnetic and parity-violating weak nuclear forces, induces tiny parity-violating energy differences (10⁻¹⁰–10⁻²¹ eV) between mirror-image molecules. This study reports the dual mirror-symmetry-breaking and second-order phase transition characteristics of mirror-symmetric 7₃-helical poly(di-n-butylsilane) in n-alkanes under static (non-stirring) conditions. In particular, n-dodecane-h₂₆ significantly enhances the circular dichroism (CD) and circularly polarized luminescence (CPL) spectra. A new (−)-CD band emerges at 299 nm below T_C1 ~ 105 °C, with a helix–helix transition at T_C2 ~ 28 °C, and exhibits g_abs = +1.3 × 10⁻² at −10 °C. Synchronously, the CPL band at 340 nm exhibiting g_lum = −0.7 × 10⁻² at 60 °C inverts to g_lum = +2.0 × 10⁻² at 0 °C. Interestingly, clockwise and counterclockwise stirring of the mixture induced non-mirror-image CD spectra. n-Dodecane-d₂₆ weakens the g_abs values by an order of magnitude, and oppositely signed CD and a lower T_C1 of ~45 °C are observed. The notable H/D isotope effect suggests that the CH₃ termini of the polysilane and n-dodecane-h₂₆, which comprise a three identical nuclear spin-1/2 system in a triple-well potential, effectively work as unidirectional hindered rotors due to the handedness of nuclear-spin-dependent parity-violating universal forces. This is supported by the (−)-sign vibrational CD bands in the symmetric and asymmetric bending modes of the CH₃ group in n-dodecane-h₂₆. Full article

Legumes consumption is still low in Western countries, and their incorporation into bakery products could be a solution. However, a minimally processed legume-based product is still a challenge because of its negative impact on acceptance by consumers. Here, an oven-baked chip recipe, based on lentil flour, was fortified with 5% hazelnut skin (HS), a byproduct of hazelnut industrial processing, to improve the nutritional, antioxidant, and sensory features of this innovative food. Indeed, HS addition allows a nutritional profile improvement, increasing the fibers from 11.71% to 15.63%, and maintaining a high protein content (24.03 g/100 g). Furthermore, HS fortification increased total phenolic compounds and total antioxidant capacity by 1.6- and 2-fold, respectively, compared to the control. Finally, HS significantly improved the overall judgment score by 1.2 points (from 5.6 to 6.8 in control and experimental chips, respectively) halving the pulse-like aroma from 8.6 to 4.3 due to the strong decrease in the dodecane compound and due to HS volatile composition, rich in hexanal. Therefore, HS could be a valuable ingredient in improving the nutritional and functional features of bakery products as well as the sensory profiles of less palatable but healthy legume-based foods. Full article

In this study, a novel slow-release material using recycled waste foamed polystyrene (WFPS) as the carrier was developed for the degradation of aniline-contaminated groundwater. Sodium persulfate (SPS) and zero-valent iron (ZVI) were embedded in WFPS, enabling the controlled and sustained release of reactive species. Systematic investigations were conducted to optimize the material’s composition and evaluate its performance under various conditions, including pH, initial aniline concentration, and the presence of common groundwater anions. The results revealed that the slow-release material effectively enhanced aniline degradation, achieving a maximum removal rate of 93.45% under flowing conditions. The degradation pathway was analyzed using GC-MS, identifying intermediates such as benzoquinone, hydroquinone, and dodecane, with eventual mineralization into CO₂ and H₂O. The material demonstrated robust performance, offering an efficient, cost-effective, and environmentally sustainable approach for in situ groundwater remediation. Full article

Atopic dermatitis (AD) or eczema is an important inflammatory chronic skin disease that brings many complications in its management and treatment. Although several chemical agents are used for treatment, the search for better anti-inflammatory and antibacterial agents of plant origin has been ongoing, since natural compounds, it is commonly believed, are less dangerous than synthetic ones. Therefore, the present study explored a medicinal plant—Eclipta prostrata (L.) L.—for its anti-inflammatory activity alone and in combination with a non-steroidal anti-inflammatory drug (NSAID), diclofenac. The plant extract was used to make a cream formulation for treating atopic dermatitis and as an antibacterial agent against Staphylococcus aures, the major infectious agent associated with AD. The phytochemical analysis of the E. prostrata extract showed the presence of various phytochemicals, including flavonoids, Tannin, saponin, terpenoids, glycosides, phenol, alkaloids, quinone, and protein. The GC-MS profiling of methanolic E. prostrata extract was performed predicted the presence of twenty important phytochemicals, including 2-[5-(2-Hydroxypropyl) oxolan-2-yl]propanoic acid, dl-Menthol, dodecane, undecane, 4,7-dimethyl-, dodecane, 2,6,10-trimethyl-, decane, 2,3,5,8-tetramethyl-, cholest-5-en-3-ol, (3.alpha.)-, TMS derivative, cyclopropane carboxylic acid, 1-hydroxy-, (2,6-di-t-butyl-4-methylphenyl) ester, alpha.-farnesene, propanoic acid, 2-methyl-, 2-ethyl-1-propyl-1,3-propanediyl ester, diethyl phthalate, corticosterone, 2-methylpropionate, hentriacontan-13-ol, O-TMS, phthalic acid, 2,4-dimethylpent-3-yl dodecyl ester, hexasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11-dodecamethyl-, acetic acid, 4-t-butyl-4-hydroxy-1,5-dimethyl-hex-2-ynyl ester, octadecane, 2-methyl- octacosane, 1-iodo-, nonacosane, and eicosyl isopropyl ether. Using an egg albumin denaturation inhibition assay, the anti-inflammatory activities of E. prostrata alone and in combination with diclofenac were investigated, and they showed 93% and 99% denaturation inhibition at 5 mg concentration of E. prostrata in alone and combination with diclofenac, respectively. Heat-induced haemolysis showed 2.5% and 2.4% of haemolysis at 5 mg of E. prostrata alone and in combination with diclofenac, respectively. An MTT assay performed using L₉₂₉ cells proved that the extract has no cytotoxic effect. The plant extract displayed potential antibacterial activity against Staphylococcus aureus; the growth was inhibited at 1 mg/mL of E. prostrata extract. Thus, based on this evidence, the authors suggest that E. prostrata extract should be studied further for its anti-inflammatory and antibacterial activities and topical application in the treatment of atopic dermatitis. Full article