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1.
Waste Manag ; 186: 205-213, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-38924981

ABSTRACT

Multilayer film packaging (MLP) waste was decomposed completely at 500 °C. Catalysts were employed to convert residue polymer to waxes via pyrolysis at 500 °C. The activities achieved from using mordenite (Si/Al = 10), H-ZSM-5 (Si/Al = 25), MCM-41, and Al-MCM-41 (Si/Al ratio of 25, 50, and 75) catalysts were studied. The yield and property of the wax were improved with the use of the catalysis with various acidity and porous structure. The low yield of the waxes, when using mordenite and H-ZSM-5 catalysts, was caused by the microporous structure and strong acidic properties of the catalysts resulting in larger amount of gas production. The MCM-41 catalyst modified with various aluminum content raised the wax yield to 60 %. Al-MCM-41(50) produced the largest amount of wax when compared to Al-MCM-41(25), Al-MCM-41(75), and MCM-41. The mild acidity and mesoporous structure of Al-MCM-41(50) significantly enhanced the paraffins structure of the obtained waxes over other structures, while lower Si/Al ratios favored the conversion of paraffins toward olefin structure. The pyrolysis of MLP with Al-MCM-41(50) produced paraffins and olefins with the middle carbon ranging (C11-20) which were similar quality to pharmaceutical grade of petroleum wax. The spent catalysts of Al-MCM-41 series gradually decreased in wax yield and paraffins composition during the sequential MLP pyrolysis; however, the activity of catalysts was recovered after calcination of the spent catalysts. Furthermore, the viscosity of waxes obtained from Al-MCM-41(50) was 2384 Pa.s at 25 °C similar to the viscosity from commercial petroleum jelly base of 2333 Pa.s.


Subject(s)
Pyrolysis , Waxes , Waxes/chemistry , Catalysis , Product Packaging , Refuse Disposal/methods
2.
J Food Sci ; 89(7): 4372-4388, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38837376

ABSTRACT

High concentrations of carnauba waxes (CRWs) that can compromise organoleptic properties are required to create self-sustained and functional oleogels. The weak physical properties and stability of 4% w/w CRW-rice bran oil (RBO) oleogel were addressed by substituting CRW with beeswax (BW) in different weight ratios. The texture profile analyzer revealed that substituting only 10% (weight ratio) of CRW with BW improved the hardness compared to the mono-CRW oleogel. The hardness of binary oleogels increased gradually as the proportion of BW increased. At a BW ratio of 70% or more, the hardness was three times higher than that of mono-BW oleogel. Rheology analysis showed the same trend as the large deformation test; however, the hardest binary oleogels had lower critical strain and yield point compared to the mono-wax oleogels, implying that they are more prone to lose their structure upon applied stress. Nevertheless, nearly all binary mixtures (except for 10%BW90%CRW) showed oil-binding capacities above 99%, suggesting improved nucleation and crystallization process. Polarized light microscopy showed the coexistence of BW and CRW crystals and changes in the size and arrangement of wax crystals upon proportional changes of the two waxes. X-ray diffraction confirmed no differences in the peaks' location, and all oleogels had ß' polymorphism. Differential scanning calorimetry showed eutectic melting behavior in some binary blends. Oxidation stability in the binary wax oleogels improved as compared to the mono-wax oleogel and bulk RBO. BW and CRW mixtures have promising oil-structuring abilities and have various properties at different ratios that have the potential to be used as solid fat substitutes. PRACTICAL APPLICATION: As a trending green oil-structuring technology, oleogelation has shown great potential to reduce saturated fats in food systems. The current research provides valuable fundamental information on the strong synergistic interactions between beeswax and carnauba wax that have the potential to be used as solid fat substitutes created with a much lower total concentration of the required wax. This will help create wax oleogels with better organoleptic properties and less negative waxy mouthfeel. Such knowledge could prove beneficial for the development of healthy products that have potential applications in meat, bakery, dairy, pharmaceutical, as well as cosmetic industries.


Subject(s)
Organic Chemicals , Oxidation-Reduction , Rheology , Waxes , Waxes/chemistry , Organic Chemicals/chemistry , X-Ray Diffraction
3.
Adv Exp Med Biol ; 2024 Jun 08.
Article in English | MEDLINE | ID: mdl-38848019

ABSTRACT

Lipids are a diverse group of compounds that play several important roles in insect physiology. Among biological lipids, the fundamental category comprises fatty acyl structures, with significant members being fatty acids (FAs). They play several crucial functions in insect physiology; they are used as the source of energy for flight and play key roles in the insect immune system. The FAs present in the insect cuticle are known to demonstrate antibacterial and antifungal activity and are considered as potential insecticides. The most abundant family of lipids are the glycerolipids, with numerous cellular functions including storage of energy, structural compartmentation of cells and organelles, and important signaling activities required for regulation of physiological processes (i.e., growth, development, reproduction, diapause, and overwintering). The phospholipids are also highly diversified key components of all cell membranes; they can modify cellular components in response to rapid cold-hardening (RCH), enhancing membrane fluidity and improving survival at low temperatures. The sphingolipids are important structural and signaling bioactive compounds, mostly detected in membranes.Insects are sterol-auxotrophs: they do not have genes, which code enzymes converting farnesyl pyrophosphate to squalene. Similarly, to mammals, the production of steroids in insects is regulated by cytochrome P450 enzymes that convert sterols (mostly cholesterol) to hormonally active steroids. The major molting hormone in insects is 20-hydroxyecdysone, and cholesterol is the required precursor; however, several exemptions from this rule have been noted. This manuscript also reviews the roles of prenol lipids, isoprenoids, lipid vitamins, polyketides, and waxes in the vital processes of insects.

4.
Foods ; 13(9)2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38731723

ABSTRACT

The intensity of the odor in food-grade paraffin waxes is a pivotal quality characteristic, with odor panel ratings currently serving as the primary criterion for its assessment. This study presents an innovative method for assessing odor intensity in food-grade paraffin waxes, employing headspace gas chromatography with mass spectrometry (HS/GC-MS) and integrating total ion spectra with advanced machine learning (ML) algorithms for enhanced detection and quantification. Optimization was conducted using Box-Behnken design and response surface methodology, ensuring precision with coefficients of variance below 9%. Analytical techniques, including hierarchical cluster analysis (HCA) and principal component analysis (PCA), efficiently categorized samples by odor intensity. The Gaussian support vector machine (SVM), random forest, partial least squares regression, and support vector regression (SVR) algorithms were evaluated for their efficacy in odor grade classification and quantification. Gaussian SVM emerged as superior in classification tasks, achieving 100% accuracy, while Gaussian SVR excelled in quantifying odor levels, with a coefficient of determination (R2) of 0.9667 and a root mean square error (RMSE) of 6.789. This approach offers a fast, reliable, robust, objective, and reproducible alternative to the current ASTM sensory panel assessments, leveraging the analytical capabilities of HS-GC/MS and the predictive power of ML for quality control in the petrochemical sector's food-grade paraffin waxes.

5.
Open Biol ; 14(5): 230430, 2024 May.
Article in English | MEDLINE | ID: mdl-38806146

ABSTRACT

Both leaves and petals are covered in a cuticle, which itself contains and is covered by cuticular waxes. The waxes perform various roles in plants' lives, and the cuticular composition of leaves has received much attention. To date, the cuticular composition of petals has been largely ignored. Being the outermost boundary between the plant and the environment, the cuticle is the first point of contact between a flower and a pollinator, yet we know little about how plant-pollinator interactions shape its chemical composition. Here, we investigate the general structure and composition of floral cuticular waxes by analysing the cuticular composition of leaves and petals of 49 plant species, representing 19 orders and 27 families. We show that the flowers of plants from across the phylogenetic range are nearly devoid of wax crystals and that the total wax load of leaves in 90% of the species is higher than that of petals. The proportion of alkanes is higher, and the chain lengths of the aliphatic compounds are shorter in petals than in leaves. We argue these differences are a result of adaptation to the different roles leaves and petals play in plant biology.


Subject(s)
Flowers , Plant Leaves , Waxes , Plant Leaves/chemistry , Plant Leaves/metabolism , Waxes/chemistry , Waxes/metabolism , Flowers/chemistry , Flowers/metabolism , Phylogeny , Plant Epidermis/chemistry , Plant Epidermis/metabolism , Plants/chemistry , Plants/metabolism , Species Specificity
6.
Plant Mol Biol ; 114(3): 36, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38598012

ABSTRACT

Increasing evidence indicates a strong correlation between the deposition of cuticular waxes and drought tolerance. However, the precise regulatory mechanism remains elusive. Here, we conducted a comprehensive transcriptome analysis of two wheat (Triticum aestivum) near-isogenic lines, the glaucous line G-JM38 rich in cuticular waxes and the non-glaucous line NG-JM31. We identified 85,143 protein-coding mRNAs, 4,485 lncRNAs, and 1,130 miRNAs. Using the lncRNA-miRNA-mRNA network and endogenous target mimic (eTM) prediction, we discovered that lncRNA35557 acted as an eTM for the miRNA tae-miR6206, effectively preventing tae-miR6206 from cleaving the NAC transcription factor gene TaNAC018. This lncRNA-miRNA interaction led to higher transcript abundance for TaNAC018 and enhanced drought-stress tolerance. Additionally, treatment with mannitol and abscisic acid (ABA) each influenced the levels of tae-miR6206, lncRNA35557, and TaNAC018 transcript. The ectopic expression of TaNAC018 in Arabidopsis also improved tolerance toward mannitol and ABA treatment, whereas knocking down TaNAC018 transcript levels via virus-induced gene silencing in wheat rendered seedlings more sensitive to mannitol stress. Our results indicate that lncRNA35557 functions as a competing endogenous RNA to modulate TaNAC018 expression by acting as a decoy target for tae-miR6206 in glaucous wheat, suggesting that non-coding RNA has important roles in the regulatory mechanisms responsible for wheat stress tolerance.


Subject(s)
Arabidopsis , MicroRNAs , RNA, Long Noncoding , RNA, Competitive Endogenous , RNA, Long Noncoding/genetics , Abscisic Acid/pharmacology , Arabidopsis/genetics , Mannitol , MicroRNAs/genetics , RNA, Messenger , Triticum/genetics , Waxes
7.
Materials (Basel) ; 17(5)2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38473574

ABSTRACT

The article presents the exploration of flax and hemp fibers' surface free energy depending on the chemical composition of the fiber, which is closely related to the plant variety and the method of extracting the fiber. For this purpose, tests of the surface free energy (SFE), evaluation of the percentage content of individual fiber components and FTIR analyses were conducted. The research was carried out with the use of fibrous materials prepared in three different ways: 1. To analyze the effect of subsequent stages of flax fibers refining process on chemical composition and SFE, 2. to explore the dependence of fiber SFE on hemp variety, the water-retting hemp fibers were used, 3. To evaluate the influence of the retting method of hemp fibers BIALOBRZESKIE variety on SFE, the fibers extracted with the use of dew and water retting were used as the research material. The study confirmed that the content of individual components in the fiber influenced its sorption capacity and therefore determined its hydrophilic properties. The values of Pearson's linear correlation coefficients determined in the statistical analysis proved that the surface free energy was strongly correlated with the content of individual components in the fibers. Understanding the wettability characteristics of bast fibers will allow modeling the properties of products made of these fibers and designing surface modification processes in order to obtain specific functionality of textile products, depending on their intended utilization.

8.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123910, 2024 Apr 05.
Article in English | MEDLINE | ID: mdl-38244432

ABSTRACT

Petroleum waxes are products derived from lubricating oils with a wide spectrum of industrial and consumer applications that depend on their composition. In addition, the intended applications of this product are also subject to the practice of blending petroleum waxes with different chemical characteristics (e.g., paraffin waxes and microwaxes) to achieve the appropriate physicochemical properties. This study introduces a novel method based on visible and near-infrared spectroscopy (Vis-NIR) combined with machine learning (ML) for the characterization of blends of the two types of commonly marketed petroleum waxes (paraffin waxes and microwaxes). With spectroscopic data, Partial Least Squared Regression (PLSR), Support Vector Regression (SVR), and Random Forest (RF) Regression-based regression ML models have been developed, obtaining satisfactory results for the characterization of the percentage of blending in petroleum waxes. Moreover, strategies using wrapper variable selection methods like the Boruta algorithm and Genetic Algorithm (GA) have been implemented to assess if fewer predictors enhance model performance. Particularly, the application of wrapper variable selection methods, specifically the Boruta algorithm, has led to an improvement in the performance of the models obtained. Results obtained by the Boruta-PLS model showed the best performance with an RMSE of 2.972 and an R2 of 0.9925 for the test set and an RMSE of 1.814 and an R2 of 0.9977 for the external validation set. Additionally, this model allowed for establishing the relative importance of the variables in the characterization of the waxes mixture, pointing out that the hydrocarbon content ratio is critical in the determination of this value. An interactive web application was developed using the best model developed for easy processing of the data by the users.

9.
Arch Toxicol ; 98(2): 551-565, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38085275

ABSTRACT

The present study evaluates the in vitro developmental toxicity and the possible underlying mode of action of DMSO extracts of a series of highly complex petroleum substances in the mouse embryonic stem cell test (mEST), the zebrafish embryotoxicity test (ZET) and the aryl hydrocarbon receptor reporter gene assay (AhR CALUX assay). Results show that two out of sixteen samples tested, both being poorly refined products that may contain a substantial amount of 3- to 7-ring polycyclic aromatic compounds (PACs), induced sustained AhR activation in the AhR CALUX assay, and concentration-dependent developmental toxicity in both mEST and ZET. The other samples tested, representing highly refined petroleum substances and petroleum-derived waxes (containing typically a very low amount or no PACs at all), were negative in all assays applied, pointing to their inability to induce developmental toxicity in vitro. The refining processes applied during the production of highly refined petroleum products, such as solvent extraction and hydrotreatment which focus on the removal of undesired constituents, including 3- to 7-ring PACs, abolish the in vitro developmental toxicity. In conclusion, the obtained results support the hypothesis that 3- to 7-ring PACs are the primary inducers of the developmental toxicity induced by some (i.e., poorly refined) petroleum substances and that the observed effect is partially AhR-mediated.


Subject(s)
Petroleum , Polycyclic Aromatic Hydrocarbons , Mice , Animals , Petroleum/toxicity , Petroleum/analysis , Zebrafish , Mouse Embryonic Stem Cells
10.
Int J Biol Macromol ; 254(Pt 2): 127776, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37907180

ABSTRACT

Inspired by the natural plant cuticles, a novel strategy was proposed for the fabrication of biomimetic plant cuticles from pullulan-graphene oxide (PU-GO) and beeswax-stearic acid (BW-SA), which could serve as hydrophilic polysaccharides and hydrophobic waxes, respectively. PU-GO and PU-GO/BW-SA in different GO concentrations (0, 10, 30 and 50 µg/mL) were prepared, and their structural characteristics and basic properties were investigated. Results showed that PU-GO/BW-SA possessed a hydrophilic layer and a hydrophobic structure similar to the structure of natural plant cuticles. The incorporation of GO enhanced the barrier properties of the films and PU-GO/BW-SA showed a higher contact angle, lower tensile strength and higher barrier properties compared with PU-GO. In addition, PU-GO/BW-SA in 10 µg/mL GO concentration (PU-GO10/BW-SA) possessed the lowest WVP (7.2 × 10-7 g/(m h Pa)) and a contact angle (93.78°) similar to natural plant cuticles. Applications in Citrus Limon Rosso further proved the potential of PU-GO10/BW-SA as a biomimetic plant cuticle in fruit preservation.


Subject(s)
Citrus , Biomimetics , Waxes/chemistry
11.
Proc Natl Acad Sci U S A ; 120(49): e2307012120, 2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38019866

ABSTRACT

The cuticle is a hydrophobic structure that seals plant aerial surfaces from the surrounding environment. To better understand how cuticular wax composition changes over development, we conducted an untargeted screen of leaf surface lipids from black cottonwood (Populus trichocarpa). We observed major shifts to the lipid profile across development, from a phenolic and terpene-dominated profile in young leaves to an aliphatic wax-dominated profile in mature leaves. Contrary to the general pattern, levels of aliphatic cis-9-alkenes decreased in older leaves following their accumulation. A thorough examination revealed that the decrease in cis-9-alkenes was accompanied by a concomitant increase in aldehydes, one of them being the volatile compound nonanal. By applying exogenous alkenes to P. trichocarpa leaves, we show that unsaturated waxes in the cuticle undergo spontaneous oxidative cleavage to generate aldehydes and that this process occurs similarly in other alkene-accumulating systems such as balsam poplar (Populus balsamifera) leaves and corn (Zea mays) silk. Moreover, we show that the production of cuticular wax-derived compounds can be extended to other wax components. In bread wheat (Triticum aestivum), 9-hydroxy-14,16-hentriacontanedione likely decomposes to generate 2-heptadecanone and 7-octyloxepan-2-one (a caprolactone). These findings highlight an unusual route to the production of plant volatiles that are structurally encoded within cuticular wax precursors. These processes could play a role in modulating ecological interactions and open the possibility for engineering bioactive volatile compounds into plant waxes.


Subject(s)
Aldehydes , Populus , Waxes/chemistry , Plant Leaves/chemistry , Triticum/chemistry , Alkenes , Zea mays , Plant Epidermis
12.
J Food Sci ; 88(12): 4879-4891, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37876294

ABSTRACT

To investigate the influence of heat treatment (HT) on Satsuma mandarin fruit's postharvest quality and cuticle composition, we immersed the fruit for 3 min in hot water at 52°C and subsequently stored them at room temperature (25°C) for 28 days, and fruit quality parameters, such as good fruit rate, weight loss rate, firmness, total soluble solids, total titratable acidity, and ascorbic acid content, were monitored. Additionally, changes in the peel's cuticle composition were analyzed, and wax crystal morphologies on the fruit surface were examined using scanning electron microscopy (SEM). The findings revealed that appropriate HT effectively preserved fruit quality. The main compositions of wax and cutin on the fruit's surface remained consistent between the HT and the CK during storage. The total content of wax and cutin initially increased, peaking on the 14th day of storage, and then decreased, falling below the levels observed on day 0. Notably, the total amount of cutin in the HT group exceeded that of the control group. Specifically, ω-hydroxy fatty acids with mid-chain oxo groups and mid-oh-ω-hydroxy fatty acids constituted approximately 90% of the total cutin content. Moreover, the HT group exhibited higher (p < 0.05) total wax content in relation to the control. Fatty acids and alkanes were the predominant components, accounting for approximately 87.5% of the total wax. SEM analysis demonstrated that HT caused wax crystals to melt and redistribute, effectively filling wax gaps. It suggests that HT holds promising potential as a green, safe, and eco-friendly commercial treatment for preserving the postharvest quality of Satsuma mandarin. PRACTICAL APPLICATION: In this study, Satsuma citrus (Citrus unshiu) underwent heat treatment (HT) and was subsequently preserved at room temperature (25°C) for 28 days. The findings revealed that HT significantly improved fruit quality compared to the control group. These findings provide valuable insights into the advancement of eco-friendly and pollution-free citrus preservation methods, offering essential strategies and process parameters for their practical application.


Subject(s)
Citrus , Citrus/chemistry , Hot Temperature , Fruit/chemistry , Ascorbic Acid/analysis , Fatty Acids/analysis
13.
Foods ; 12(18)2023 Sep 07.
Article in English | MEDLINE | ID: mdl-37761070

ABSTRACT

Petroleum-derived waxes are used in the food industry as additives to provide texture and as coatings for foodstuffs such as fruits and cheeses. Therefore, food waxes are subject to strict quality controls to comply with regulations. In this research, a combination of visible and near-infrared (Vis-NIR) spectroscopy with machine learning was employed to effectively characterize two commonly marketed petroleum waxes of food interest: macrocrystalline and microcrystalline. The present study employed unsupervised machine learning algorithms like hierarchical cluster analysis (HCA) and principal component analysis (PCA) to differentiate the wax samples based on their chemical composition. Furthermore, nonparametric supervised machine learning algorithms, such as support vector machines (SVMs) and random forest (RF), were applied to the spectroscopic data for precise classification. Results from the HCA and PCA demonstrated a clear trend of grouping the wax samples according to their chemical composition. In combination with five-fold cross-validation (CV), the SVM models accurately classified all samples as either macrocrystalline or microcrystalline wax during the test phase. Similar high-performance outcomes were observed with RF models along with five-fold CV, enabling the identification of specific wavelengths that facilitate discrimination between the wax types, which also made it possible to select the wavelengths that allow discrimination of the samples to build the characteristic spectralprint of each type of petroleum wax. This research underscores the effectiveness of the proposed analytical method in providing fast, environmentally friendly, and cost-effective quality control for waxes. The approach offers a promising alternative to existing techniques, making it a viable option for automated quality assessment of waxes in food industrial applications.

14.
Gels ; 9(8)2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37623082

ABSTRACT

Waxes and monoglycerides (MGs) added in edible oils form oleogels that can be used as an alternative structured fat, providing healthier substitutes to saturated and trans fats in foods. This study aimed to investigate the properties of oleogels formed by the interaction between monoglycerides and different waxes in various edible oils. For this purpose, waxes, namely rice bran (RBW), candelilla (CDW), sunflower (SW), and beeswax (BW), together with MGs in a total concentration level of 15% (w/w) were dissolved in several edible oils (olive, sunflower, sesame, and soybean). The structure and physical properties of oleogels were investigated using texture analysis, polarized light microscopy, melting point measurements, and Fourier-transform infrared spectroscopy (FTIR). The hardest structure was produced by SW/MG (5.18 N), followed by CDW (2.87 N), RBW (2.34 N), BW (2.24 N) and plain MG (1.92 N). Furthermore, RBW and SW led to a higher melting point (69.2 and 67.3 °C) than the plain MG oleogels (64.5 °C). Different crystallization structures, i.e., needle-like crystals and spherulites, were observed depending on the type of wax, its concentration, and the oil used. These results can be used to control the properties of oleogels by adjusting the gelator composition for a variety of potential food applications.

15.
Plant J ; 116(5): 1293-1308, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37596909

ABSTRACT

With climate change, an aggravation in summer drought is expected in the Mediterranean region. To assess the impact of such a future scenario, we compared the response of Quercus pubescens, a drought-resistant deciduous oak species, to long-term amplified drought (AD) (partial rain exclusion in natura for 10 years) and natural drought (ND). We studied leaf physiological and physico-chemical trait responses to ND and AD over the seasonal cycle, with a focus on chemical traits including major groups of central (photosynthetic pigments and plastoquinones) and specialized (tocochromanols, phenolic compounds, and cuticular waxes) metabolites. Seasonality was the main driver of all leaf traits, including cuticular triterpenoids, which were highly concentrated in summer, suggesting their importance to cope with drought and thermal stress periods. Under AD, trees not only reduced CO2 assimilation (-42%) in summer and leaf concentrations of some phenolic compounds and photosynthetic pigments (carotenoids from the xanthophyll cycle) but also enhanced the levels of other photosynthetic pigments (chlorophylls, lutein, and neoxanthin) and plastochromanol-8, an antioxidant located in chloroplasts. Overall, the metabolomic adjustments across seasons and drought conditions reinforce the idea that Q. pubescens is highly resistant to drought although significant losses of antioxidant defenses and photoprotection were identified under AD.


Subject(s)
Quercus , Quercus/metabolism , Antioxidants/metabolism , Seasons , Forests , Rain , Plant Leaves/metabolism , Trees/metabolism , Droughts , Water/metabolism
16.
Cureus ; 15(6): e41235, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37529510

ABSTRACT

Introduction Tooth loss significantly impacts individuals' functional capabilities and quality of life. Fixed partial dentures have been a reliable treatment method for tooth replacement, with their fabrication often involving waxes. Waxes play a crucial role in creating a wax pattern in dental restoration; in particular, inlay waxes play a role in the shape, size, and contour of the restorations. However, these waxes have inherent disadvantages, including a high thermal expansion coefficient and propensity to warp or distort over time. This study aimed to compare wax patterns derived from two heat sources, an electric heat source and a conventional flame, to enhance their marginal accuracy and dimensional stability. Methods This study used an abutment resembling a prepared maxillary right central incisor designed via computer-aided design software and milled from zirconia. Inlay wax was melted using either an electrically heated spatula or a conventional flame, poured into a metal sleeve or a cuboidal mold, and allowed to cool to room temperature. The wax patterns were stored at room temperature for one hour and 24 hours. Subsequently, linear and volumetric measurements were taken to assess the shrinkage of the wax patterns. Results Patterns fabricated using the electric heat source showed less shrinkage at both time points for linear shrinkage and at one hour for volumetric shrinkage than those made using the conventional flame. However, by the 24th hour, patterns made with the electric heat source showed more volumetric shrinkage than those made with the conventional heat source. Significant shrinkage was observed between one hour and 24 hours for both heat sources, suggesting that wax patterns should be invested immediately after fabrication for maximum precision. Conclusions The results suggest that electric heating may be a viable alternative to conventional flame for minimizing discrepancies in wax patterns, particularly in the initial stages of wax pattern fabrication. However, prolonged use may lead to greater volumetric shrinkage with electric heating. These findings point to the potential of electric heating as an alternative to conventional flame in dental restorations, although further research is needed to validate and expand upon these findings.

17.
Microsc Res Tech ; 86(9): 1177-1196, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37486152

ABSTRACT

Morphoanatomical studies can provide useful and relevant information to support taxonomic groupings. Jacquemontia evolvuloides shows great morphological variability, which has led to numerous taxonomic classifications. To determine if anatomical characters can be used to recognize operational taxonomic units within populations of that species, we analyzed the leaves and stems of 22 populations using light and scanning electron microscopy. The variability of the analyzed characters allowed the grouping of these populations into five morphotypes. The presence of paracytic stomata, laticiferous canals, and stellate trichomes can be considered diagnostic characters of J. evolvuloides. The presence and types of epicuticular waxes, as well as a layer similar to palisade parenchyma in the petioles and stems, the classifications of glandular trichomes, and new types of stomata (anomocytic, anomotetracytic, and brachyparatetracytic) are reported here for the first time for Jacquemontia. The results discussed here help clarify the classification of this species complex and contribute to the taxonomy of Jacquemontia-a genus that has historically been difficult to define due to its wide morphological variation at the species level. RESEARCH HIGHLIGHTS: Seven types of epicuticular waxes were identified among J. evolvuloides specimens: granules, threads, entire platelets, coiled rodlets, fissured layers, membranous platelets, and tubules. Six types of trichomes were observed among J. evolvuloides populations: stellate, malpighiaceous, sessile peltate glandular, short pedunculate glandular, stipitate-glandular, and capitate glandular. We observed that six populations of Jacquemontia evolvuloides located in the Brazilian Caatinga domain have unprecedented sessile peltate trichomes restricted to the main leaf midrib, which were only observed under light microscopy.


Subject(s)
Convolvulaceae , Microscopy, Electron, Scanning , Plant Leaves/anatomy & histology , Trichomes/anatomy & histology , Waxes
18.
Chem Biodivers ; 20(7): e202300553, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37329266

ABSTRACT

This is the first study on cuticular wax variability of Abies alba, A.×borisii-regis and A. cephalonica, using 18 native populations from the assumed hybrid zone in the Balkan Peninsula. Presence of 13 n-alkanes with chain-lengths ranging from C21 to C33 , one primary alcohol, two diterpenes, one triterpene and one sterol was determined in hexane extracts of 269 needle samples. The multivariate statistical analyses at the population level entirely failed in supporting circumscription of Balkan Abies taxa and therefore, in identifying hybrid populations. However, performed at the species level, these analyses revealed a certain tendency of differentiation between A. alba and A. cephalonica, while individuals of A.×borisii-regis were largely overlapped by the clouds of both parent species. Finally, the correlation analysis suggested that the observed variation of wax compounds was probably genetically conditioned and that it does not represent an adaptive response to various environmental factors.


Subject(s)
Abies , Plant Leaves , Humans , Plant Leaves/chemistry , Balkan Peninsula , Waxes/analysis , Ethanol
19.
Foods ; 12(12)2023 Jun 07.
Article in English | MEDLINE | ID: mdl-37372502

ABSTRACT

Waxes, phospholipids, free fatty acids, peroxides, aldehydes, soap, trace metals and moisture present in crude sunflower oil have a negative effect on the oil quality and are, therefore, removed during the refining process. Waxes crystallizing at low temperatures are removed during winterization by cooling and filtration. Waxes have poor filtration characteristics and an industrial filtration process must be enhanced by the use of filtration aids, which improve filter cake structure and properties, and consequently prolong the filtration cycle. Today, traditional filtration aids (diatomite, perlite, etc.) being used in the industry are frequently replaced by cellulose-based aids. The aim of this study is to examine the effect of oil filtration assisted by two cellulose-based filtration aids on the chemical parameters (wax, moisture, phospholipids, soaps, and fatty acids), oil transparency, carotenoids, and Fe and Cu content of sunflower oil obtained in an industrial horizontal pressure leaf filter. In order to investigate the mentioned parameters, the following techniques were used: gravimetric (waxes and moisture content), spectrophotometric (phospholipids and carotenoid content and oil transparency), volumetric (soaps and free fatty acids content) as well as inductively coupled plasma mass spectrometry (ICP-MS) for Fe and Cu content. An artificial neural network model (ANN) was employed for the prediction of removal efficiency based on the chemical quality, oil transparency, Fe and Cu content in oils before filtration, as well as filtration aid quantity and filtration time. Cellulose-based filtration aids had multiple beneficial effects; on average, 99.20% of waxes, 74.88% of phospholipids, 100% of soap, 7.99% of carotenoids, 16.39% of Fe and 18.33% of Cu were removed.

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