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1.
Water Res ; 261: 122062, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-39002419

RESUMO

Liquid crystal monomers (LCMs) are a new class of emerging pollutants with high octanol-water partition coefficients; however, their transformation behavior and associated risk to environments with high organic matter content has rarely been reported. In this study, we investigated the photodegradation kinetics, mechanism, and toxicity variation of 23 LCMs on leaf wax models (e.g., organic solvents methanol and n-hexane). The order of the photolysis rates of these LCMs were biphenylethyne LCMs > phenylbenzoate LCMs > diphenyl/terphenyl LCMs under simulated sunlight, while the phenylcyclohexane LCMs were resistant to photodegradation. The phenylbenzoate and biphenylethyne LCMs mainly undergo direct photolysis, while the diphenyl/terphenyl LCMs mainly undergo self-sensitized photolysis. The main photolysis pathways are the cleavage of ester bonds for phenylbenzoate LCMs, the addition, oxidation and cleavage of alkynyl groups for biphenylethyne LCMs, and the cleavage/oxidation of chains attached to phenyls and the benzene ring opening for diphenyl/terphenyls LCMs. Most photolysis products remained toxic to aquatic organisms to some degree. Additionally, two quantitative structure-activity relationship models for predicting kobs of LCMs in methanol and n-hexane were developed, and employed to predict kobs of 93 LCMs to fill the kobs data gap in systems mimicking leaf surfaces. These results can be helpful for evaluating the fate and risk of LCMs in environments with high content of organic phase.

2.
Materials (Basel) ; 17(13)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38998385

RESUMO

The effects of four modifiers were studied to compare their roles in the self-healing ability of asphalt binder: elemental sulfur, with a known plasticizing effect; wax, containing long alkane chains (>C50) with a known crystallizing capability; a plastic oil, with short alkane chains (

3.
EFSA J ; 22(7): e8888, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38993592

RESUMO

The European Commission requested the EFSA Panel on Plant Health to conduct a pest categorisation of Ceroplastes rubens Maskell (Hemiptera: Coccidae), following the commodity risk assessments of Acer palmatum plants grafted on A. davidii and Pinus parviflora bonsai plants grafted on P. thunbergii from China, in which C. rubens was identified as a pest of possible concern to the European Union (EU). The pest, which is commonly known as the pink, red or ruby wax scale, originates in Africa and is highly polyphagous attacking plants from more than 193 genera in 84 families. It has been present in Germany since 2010 in a single tropical glasshouse. It is known to attack primarily tropical and subtropical plants, but also other host plants commonly found in the EU, such as Malus sylvestris, Prunus spp., Pyrus spp. and ornamentals. It is considered an important pest of Citrus spp. The pink wax scale reproduces mainly parthenogenetically, and it has one or two generations per year. Fecundity ranges from 5 to 1178 eggs. Crawlers settle usually on young twigs and later stages are sessile. All life stages of C. rubens egest honeydew on which sooty mould grows. Host availability and climate suitability suggest that parts of the EU would be suitable for establishment. Plants for planting and cut branches provide the main pathways for entry. Crawlers could spread over short distances naturally through wind, animals, humans or machinery. C. rubens could be dispersed more rapidly and over long distances via infested plants for planting for trade. The introduction of C. rubens into the EU could lead to outbreaks causing damage to orchards, amenity ornamental trees and shrubs. Phytosanitary measures are available to inhibit the entry and spread of this species. C. rubens satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

4.
Polymers (Basel) ; 16(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39000742

RESUMO

This research aimed to produce eco-friendly straws using soy protein isolate (SPI) and cassava starch (CS) at different ratios by the extrusion technique and by coating with beeswax and shellac wax. Three straw formulations (F) (F1: 24.39% SPI-24.39% CS; F2: 19.51% SPI-29.37% CS; and F3: 14.63% SPI-34.15% CS) were prepared, incorporating glycerol (14.6% w/w) and water (36.6% w/w). After extrusion and drying at 80 °C for 20 h, visual assessment favored F2 straws due to smoother surfaces, the absence of particles, and enhanced straightness. For the physical property test, the straws were softened in pH buffer solutions for 5 min. To simulate practical application, mechanical bending strength was studied under different relative humidity (RH) settings. Water absorption reduced the strength as RH increased. F2 straws outperformed other formulations in bending strength at 54% RH. For hydrophobic coatings, F2 was chosen. Beeswax- and shellac wax-coated straws displayed negligible water absorption and sustained their integrity for over 6 h compared to uncoated straws. This study shows that extrusion and natural coatings may make sustainable straws from SPI and CS. These efforts help meet the growing demand for eco-friendly plastic alternatives, opening up new options for single-use straws.

5.
Cureus ; 16(6): e61950, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38978887

RESUMO

Melorheostosis is a noncancerous bone disease characterized by abnormal bone and soft tissue growth. Despite being identified almost a century ago, there are still many unknown aspects surrounding this condition. It can often be an incidental discovery, with patients experiencing associated pain and deformities. Diagnosis typically relies on X-rays, although not all cases exhibit the classic candle wax appearance. A new imaging sign known as the "dumpling on a plate sign" has been proposed for flat bones for both MRI and CT scans. A biopsy may be necessary in cases of uncertainty, as there is not a definitive histological feature. It is not uncommon for melorheostosis to be linked with other conditions, and a collaborative approach involving a multidisciplinary team should be considered. This condition should be considered in the differential diagnosis of sclerotic bone conditions. Management is generally aimed at symptom relief, either through conservative measures or surgical intervention.

6.
Anal Bioanal Chem ; 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39030399

RESUMO

Wax esters play critical roles in biological systems, serving functions from energy storage to chemical signaling. Their diversity is attributed to variations in alcohol and acyl chains, including their length, branching, and the stereochemistry of double bonds. Traditional analysis by mass spectrometry with collisional activations (CID, HCD) offers insights into acyl chain lengths and unsaturation level. Still, it falls short in pinpointing more nuanced structural features like the position of double bonds. As a solution, this study explores the application of 213-nm ultraviolet photodissociation (UVPD) for the detailed structural analysis of wax esters. It is shown that lithium adducts provide unique fragments as a result of Norrish and Norrish-Yang reactions at the ester moieties and photoinduced cleavages of double bonds. The product ions are useful for determining chain lengths and localizing double bonds. UVPD spectra of various wax esters are presented systematically, and the effect of activation time is discussed. The applicability of tandem mass spectrometry with UVPD is demonstrated for wax esters from natural sources. The UHPLC analysis of jojoba oil proves the compatibility of MS2 UVPD with the chromatography time scale, and a direct infusion is used to analyze wax esters from vernix caseosa. Data shows the potential of UVPD and its combination with CID or HCD in advancing our understanding of wax ester structures.

7.
J Exp Bot ; 2024 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-39041593

RESUMO

Cuticular wax (CW) is the first defensive barrier of plants that forms a waterproof barrier, protects the plant from desiccation, and defends against insects, pathogens, and UV radiation. Sorghum, an important grass crop with high heat and drought tolerance, exhibits a much higher wax load than other grasses and the model plant Arabidopsis. In this study, we explored the regulation of sorghum CW biosynthesis using a bloomless mutant. The CW on leaf sheaths of bloomless 41 (bm41) mutant showed significantly reduced very long-chain fatty acids (VLCFAs), triterpenoids, alcohols, and other wax components, with an overall 86% decrease in total wax content compared to the wild-type. Notably, the 28-carbon and 30-carbon VLCFAs were decreased in the mutants. Using bulk segregant analysis, we identified the causal gene of the bloomless phenotype as a leucine-rich repeat transmembrane protein kinase. Transcriptome analysis of the wild-type and bm41 mutant leaf sheaths revealed BM41 as a positive regulator of lipid biosynthesis and steroid metabolism. BM41 may regulate CW biosynthesis by regulating the expression of the gene encoding 3-ketoacyl-CoA synthase 6. Identification of BM41 as a new regulator of CW biosynthesis provides fundamental knowledge for improving grass crops' heat and drought tolerance by increasing CW.

8.
BMC Plant Biol ; 24(1): 623, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951751

RESUMO

BACKGROUND: Ideally, the barrier properties of a fruit's cuticle persist throughout its development. This presents a challenge for strawberry fruit, with their rapid development and thin cuticles. The objective was to establish the developmental time course of cuticle deposition in strawberry fruit. RESULTS: Fruit mass and surface area increase rapidly, with peak growth rate coinciding with the onset of ripening. On a whole-fruit basis, the masses of cutin and wax increase but on a unit surface-area basis, they decrease. The decrease is associated with marked increases in elastic strain. The expressions of cuticle-associated genes involved in transcriptional regulation (FaSHN1, FaSHN2, FaSHN3), synthesis of cutin (FaLACS2, FaGPAT3) and wax (FaCER1, FaKCS10, FaKCR1), and those involved in transport of cutin monomers and wax constituents (FaABCG11, FaABCG32) decreased until maturity. The only exceptions were FaLACS6 and FaGPAT6 that are presumably involved in cutin synthesis, and FaCER1 involved in wax synthesis. This result was consistent across five strawberry cultivars. Strawberry cutin consists mainly of C16 and C18 monomers, plus minor amounts of C19, C20, C22 and C24 monomers, ω-hydroxy acids, dihydroxy acids, epoxy acids, primary alcohols, carboxylic acids and dicarboxylic acids. The most abundant monomer is 10,16-dihydroxyhexadecanoic acid. Waxes comprise mainly long-chain fatty acids C29 to C46, with smaller amounts of C16 to C28. Wax constituents are carboxylic acids, primary alcohols, alkanes, aldehydes, sterols and esters. CONCLUSION: The downregulation of cuticle deposition during development accounts for the marked cuticular strain, for the associated microcracking, and for their high susceptibility to the disorders of water soaking and cracking.


Assuntos
Fragaria , Frutas , Lipídeos de Membrana , Ceras , Fragaria/crescimento & desenvolvimento , Fragaria/genética , Fragaria/metabolismo , Fragaria/enzimologia , Frutas/crescimento & desenvolvimento , Frutas/genética , Frutas/metabolismo , Ceras/metabolismo , Lipídeos de Membrana/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética
9.
J Sci Food Agric ; 2024 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-39030951

RESUMO

BACKGROUND: The first step in the contamination of leafy vegetables by human pathogens is their attachment to the leaf surface. The success of this is influenced strongly by the physical and chemical characteristics of the surface itself (number and size of stomata, presence of trichomes and veins, epicuticular waxes, hydrophobicity, etc.). This study evaluated the attachment of Salmonella enterica to 30 baby-leaf salads and tested whether the differences found among them were related to the following leaf traits: hydrophobicity, roughness, and epicuticular waxes. RESULTS: Differences in susceptibility to contamination by S. enterica were found between the 30 baby-leaf salads investigated. The lowest attachment was found in wild lettuce (Lactuca serriola L.) and lamb's lettuce 'Trophy F1' (Valerianella locusta [L.] Laterr.), with values of 1.63 ± 0.39 Log(CFU/cm2) and 1.79 ± 0.54 Log(CFU/cm2), respectively. Attachment was correlated with hydrophobicity (measured as contact angle) (r = -0.39) and epicuticular waxes (r = -0.81) but not with roughness (r = 0.24). The most important wax components for attachment were alcohols and, in particular, the three-dimensional (3D) wax crystals of C26 alcohol, but fatty acids probably also had a role. Both these compounds increased hydrophobicity. The presence of thymol, whose antimicrobial properties are well known, was found in lamb's lettuce. CONCLUSIONS: The findings of this study can help to predict and control the attachment and contamination of leafy salads by enterobacteria. They also provide useful information for breeding programs aiming to develop cultivars that are less susceptible to human pathogens, enhancing the food safety of vegetables. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

10.
Integr Comp Biol ; 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38982316

RESUMO

The striking appearance of wax 'tails' - posterior wax projections on planthopper nymphs - has captivated entomologists and naturalists alike. Despite their intriguing presence, the functional roles of these formations remain largely unexplored. This study leverages high-speed imaging to uncover the biomechanical implications of wax structures in the aerial dynamics of planthopper nymphs (Ricania sp.). We quantitatively demonstrate that removing wax tails significantly increases body rotations during jumps. Specifically, nymphs without wax undergo continuous rotations, averaging 4.2 ± 1.8 per jump, in contrast to wax-intact nymphs, who do not complete a full rotation, averaging only 0.7 ± 0.2 per jump. This along with significant reductions in angular and translational velocity from takeoff to landing suggest that aerodynamic drag forces on wax structures effectively counteract rotation. These stark differences in body rotation correlate with landing success: nymphs with wax intact achieve a near perfect landing rate of 98.5%, while those without wax manage only a 35.5% success rate. Jump trajectory analysis reveals that wax-intact jumps transition from parabolic to asymmetric shapes at higher take-off velocities and show a significantly greater reduction in velocity from takeoff to landing compared to wax-removed jumps, demonstrating how wax structures help nymphs achieve more stable, controlled descents. Our findings confirm the aerodynamic self-righting functionality of wax tails in stabilizing planthopper nymph landings, advancing our understanding of the complex relationship between wax morphology and aerial maneuverability, with broader implications for wingless insect aerial adaptations and bioinspired robotics.

11.
Plants (Basel) ; 13(13)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38999643

RESUMO

Stem color is an important agronomic trait of wax gourds. However, its regulatory genes have not been identified. In this study, 105 inbred lines constructed from two parents (GX-71 and MY-1) were sequenced and quantitative trait loci sequencing was used to mine the genes that regulate stem color in wax gourds. The results identified two quantitative trait loci related to stem color, qSC5 and qSC12, located on Chr05 (11,134,567-16,459,268) and Chr12 (74,618,168-75,712,335), respectively. The qSC5 had a phenotypic variation rate of 36.9% and a maximum limit of detection of 16.9. And the qSC12 had a phenotypic variation rate of 20.9%, and a maximum limit of detection of 11.2. Bch05G003950 (named BchAPRR2) and Bch12G020400 were identified as candidate genes involved in stem color regulation in wax gourds. The chlorophyll content and expression of BchAPRR2 and Bch12G020400 were significantly higher in green-stemmed wax gourds than in white-stemmed ones. Therefore, BchAPRR2 and Bch12G020400 were considered the main and secondary regulatory genes for wax gourd stem color, respectively. Finally, InDel markers closely linked to BchAPRR2 were developed to validate the prediction of wax gourd stem color traits in 55 germplasm lines, with an accuracy of 81.8%. These findings lay the foundation for exploring the genetic regulation of wax gourd stem color and future research on wax gourd breeding.

12.
Ann Bot ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38836501

RESUMO

BACKGROUND AND AIMS: The benefits and costs of amphistomy (AS) vs. hypostomy (HS) are not fully understood. Here, we quantify benefits of access of CO2 through stomata on the upper (adaxial) leaf surface, using 13C abundance in the adaxial and abaxial epicuticular wax. Additionally, a relationship between the distribution of stomata and epicuticular wax (EW) on the opposite leaf sides is studied. METHODS: We suggest that the 13C content of long-chain aliphatic compounds of cuticular wax records the leaf internal CO2 concentration in chloroplasts adjacent to the adaxial and abaxial epidermes. This unique property stems from (i) wax synthesis being located exclusively in epidermal cells and (ii) ongoing wax renewal over the whole leaf lifespan. Compound-specific and bulk wax 13C abundance (δ) was related to amphistomy level (ASL, fraction of adaxial in all stomata) of four AS and five HS species grown under various levels of irradiance. The isotopic polarity of EW, i.e. the difference in abaxial and adaxial δ(δab-δad), was used to calculate the leaf dorsi-ventral CO2 gradient. Leaf-side specific EW deposition, amphiwaxy level (AWL), was estimated and related to ASL. KEY RESULTS: In HS species, the CO2 concentration in the adaxial epidermis was lower than in the abaxial one independently of light conditions. In high-light and low-light grown AS leaves, the isotopic polarity and CO2 gradient varied in parallel with ASL. AS leaves grown under high light increased ASL compared to low light, and δab-δad approached near-zero values. Changes in ASL occurred concomitantly with changes in AWL. CONCLUSIONS: The leaf wax isotopic polarity is a newly identified leaf trait, distinguishing between hypo- and amphistomatous species and indicating that increased ASL in sun-exposed AS leaves reduces the CO2 gradient across the leaf mesophyll. Stomata and epicuticular wax deposition follow similar leaf-side patterning.

13.
Small ; : e2402765, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38940416

RESUMO

Droplet-based electricity generators (DEGs) are increasingly recognized for their potential in converting renewable energy sources. This study explores the interplay of surface hydrophobicity and stickiness in improving DEG efficiency. It find that the high-performance C-WaxDEGs leverage both these properties. Specifically, DEGs incorporating polydimethylsiloxane (PDMS) with carnauba wax (C-wax) exhibit increased output as surface stickiness decreases. Through experimental comparisons, PDMS with 1wt.% C-wax demonstrated a significant power output increase from 0.07 to 1.2 W m- 2, which attribute to the minimized adhesion between water molecules and the polymer surface, achieved by embedding C-wax into PDMS surface to form microstructures. This improvement in DEG performance is notable even among samples with similar surface potentials and contact angles, suggesting that C-wax's primary contribution is in reducing surface stickiness rather than altering other surface properties. The further investigations into the C-WaxDEG variant with 1wt.% C-wax PDMS uncover its potential as a sensor for water quality parameters such as temperature, pH, and heavy metal ion concentration. These findings open avenues for the integration of C-WaxDEGs into flexible electronic devices aimed at environmental monitoring.

14.
Gels ; 10(6)2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38920943

RESUMO

The objective of this study was to develop candelilla wax oleogels with hemp seed oil and olive oil and use them as a fat source in the development of new plant-based ice cream assortments. Oleogels were structured with 3 and 9% candelilla wax and characterized by oil-binding capacity, peroxide value and color parameters. The oil-binding capacities of 9% wax oleogels were significantly higher than those of 3% wax oleogels, while peroxide values of oleogels decrease with increasing wax dosage. All oleogel samples are yellow-green due to the pigments present in the oils and candelilla wax. Physicochemical (pH, titratable acidity, soluble solids, fat, protein) and rheological (viscosity and viscoelastic modulus) parameters of plant-based ice cream mixes with oleogels were determined. Also, sensory attributes and texture parameters were investigated. The results showed that titratable acidity and fat content of plant-based ice cream samples increased with increasing wax percentage, while pH, soluble solids and protein values are more influenced by the type of plant milk used. The plant-based ice cream sample with spelt milk, hemp oil and 9% candelilla wax received the highest overall acceptability score. The hardness of the plant-based ice cream samples increased as the percentage of candelilla wax added increased.

15.
Gels ; 10(6)2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38920945

RESUMO

The aim of this study was to produce Bologna sausages rich in unsaturated fatty acids and to evaluate this replacement on the structural characteristics. For the purpose of a comparative analysis, three different types of sausages were produced, distinct only in the type of fat used: I. sausages obtained with pork backfat (PBF), II. sausages produced with oleogel formed from refined sunflower oil and glycerol monostearate (GM_OG), and III. with candelilla wax oleogel (CW_OG). The meat composition was also analyzed to better understand the process in the dynamics and the finished products were analyzed both uncooked and cooked. The enhanced oil-binding capacity of oleogels suggests their potential value as substitutes for saturated fats (>99%). In terms of meat composition textural analysis, the highest hardness value was registered for PBF_C of 25.23 N, followed by a CW_OG_C of 13.08 N and a GM_OG_C of 12.27 N. However, adhesiveness, cohesiveness, springiness index, and gumminess showed similar values between samples. Reformulation of products with oleogels as a fat source abundant in mono- and polyunsaturated fatty acids resulted in uncooked products exhibiting reduced hardness values of 49.01 N (CW_OG_US) and 40.51 N (GM_OG_US), compared to 65.03 N (PBF_US). Color results of the cross-section color can indicate the potential for consumer acceptance due to the reduced color differences between the conventional and oleogel samples.

16.
Heliyon ; 10(11): e31879, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38882355

RESUMO

The paper deals with the design and execution of the test of the castability into preheated plaster moulds. Castability is an important parameter for the evaluation of foundry alloys. When the metal does not run, it usually causes an irreparable defect in the casting. Therefore, it is necessary to verify this technological property correctly for different types of moulds. The castability test for plaster moulds and bronze is not defined, therefore The Vertical Bar Test was adopted, subsequently modified, and applied to plaster moulds. The models are made of wax and the plaster moulds are made according to the manufacturer's prescription and heated to a predetermined temperature. Copper alloy specifically CuSn10 was selected as the alloy to be investigated. The aim of the experiment is to correctly set up and observe the parameters and the method of performing the castability test using gravity casting technology in plaster moulds. It is assumed, as the casting temperature increases, the run-in length of the metal alloy will increase. An important goal is to obtain relevant results, as many variables affect the progress of the test and so there is a risk of error. Due to the time-consuming nature of producing a real disposable model and mould, any failure to succeed would have an economic impact on the foundry, affecting the price of castings. The new method for evaluating castability in plaster moulds can be applied to other types of alloys when temperature changes occur.

17.
Front Plant Sci ; 15: 1379299, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38882571

RESUMO

The commonly used analytical tools for metabolomics cannot directly probe metabolic activities or distinguish metabolite differences between cells and suborgans in multicellular organisms. These issues can be addressed by in-vivo isotope labeling and mass spectrometry imaging (MSI), respectively, but the combination of the two, a newly emerging technology we call MSIi, has been rarely applied to plant systems. In this study, we explored MSIi of Arabidopsis thaliana with D2O labeling to study and visualize D-labeling in three classes of lipids: arabidopsides, chloroplast lipids, and epicuticular wax. Similar to other stress responses, D2O-induced stress increased arabidopsides in an hour, but it was relatively minor for matured plants and reverted to the normal level in a few hours. The D-labeling isotopologue patterns of arabidopsides matched with those of galactolipid precursors, supporting the currently accepted biosynthesis mechanism. Matrix-assisted laser desorption/ionization (MALDI)-MSI was used to visualize the spatiotemporal distribution of deuterated chloroplast lipids, pheophytin a, MGDGs, and DGDGs, after growing day-after-sowing (DAS) 28 plants in D2O condition for 3-12 days. There was a gradual change of deuteration amount along the leaf tissues and with a longer labeling time, which was attributed to slow respiration leading to low D2O concentration in the tissues. Finally, deuterium incorporation in epicuticular wax was visualized on the surfaces of the stem and flower. The conversion efficiency of newly synthesized C30 aldehyde to C29 ketone was very low in the lower stem but very high at the top of the stem near the flower or on the flower carpel. This study successfully demonstrated that MSIi can unveil spatiotemporal metabolic activities in various tissues of A. thaliana.

18.
Food Res Int ; 189: 114579, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38876599

RESUMO

Utilizing waxes to gel oils presents a viable approach for diminishing trans and saturated fat levels in commercial fats such as margarines. This technique ensures that oleogels mimic traditional fats in terms of rheological properties, oil-binding capacity, and overall structure. Our study employed cooling-shear rates to finely adjust physical characteristics, evaluating rheology via SAOS-LAOS, oil retention, and crystal structure of wax oleogels, compared against commercial margarines as benchmarks. Findings indicate that wax oleogels, under specific cooling/shear conditions, exhibit softer yet more ductile-like behavior, akin to margarine, while retaining oil effectively. This similarity is evidenced through Lissajous curves and plastic dissipation ratio during yielding, reflecting a ductile yielding response characterized by square-like Lissajous curves and a plastic dissipation ratio index approximating one. Although these crystallization conditions influence the mechanical properties of wax oleogels, they do not alter oil losses or wax characteristics.


Assuntos
Margarina , Compostos Orgânicos , Reologia , Ceras , Ceras/química , Compostos Orgânicos/química , Margarina/análise , Cristalização
19.
New Phytol ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38863314

RESUMO

Nicotiana benthamiana is predominantly distributed in arid habitats across northern Australia. However, none of six geographically isolated accessions shows obvious xerophytic morphological features. To investigate how these tender-looking plants withstand drought, we examined their responses to water deprivation, assessed phenotypic, physiological, and cellular responses, and analysed cuticular wax composition and wax biosynthesis gene expression profiles. Results showed that the Central Australia (CA) accession, globally known as a research tool, has evolved a drought escape strategy with early vigour, short life cycle, and weak, water loss-limiting responses. By contrast, a northern Queensland (NQ) accession responded to drought by slowing growth, inhibiting flowering, increasing leaf cuticle thickness, and altering cuticular wax composition. Under water stress, NQ increased the heat stability and water impermeability of its cuticle by extending the carbon backbone of cuticular long-chain alkanes from c. 25 to 33. This correlated with rapid upregulation of at least five wax biosynthesis genes. In CA, the alkane chain lengths (c. 25) and gene expression profiles remained largely unaltered. This study highlights complex genetic and environmental control over cuticle composition and provides evidence for divergence into at least two fundamentally different drought response strategies within the N. benthamiana species in < 1 million years.

20.
Swiss Dent J ; 134(3): 18-34, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38864504

RESUMO

This study investigated and compared the consistency and compressive strength of two commercially available paraffin wax chewing gums (Aurosan (AU) and GC Europe (GC)), as well as their impact on stimulated salivary flow rate. Instrumental texture analysis was uti-lized to assess the consistency and compressive strength of AU and GC during a 7-min chewing period. Subsequently, stimulated salivary flow rate (sSFR) was evaluated in healthy subjects using AU and GC over a 7-minute period. The compressive strengths from the pre-liminary test were compared over time with the sialometry data. Eighty-one test subjects, comprising 33 men and 48 women, participated. Over the 7-min measurement period, dif-ferences were observed in the total amount of saliva accumulated per minute. Direct com-parison of AU and GC revealed that regardless of age and gender, the amount of saliva formed after 1 min was 0.63 times less with AU than with GC (95% CI: 0.56 - 0.70; P < 0.001). The accumulated saliva volume with AU was also significantly lower than that with GC in the first 4 min (P = 0.016). However, from minute 5 onwards, the two products no longer showed statistical differences in the total amount of saliva. Comparison of the com-pressive strength of AU and GC showed that the values after 1 and 2 min were significantly higher for AU than for GC (P < 0.05); for all other time points, the compressive strength was higher for GC. In the mixed-effects model after log-transformation of compressive strength and saliva volume, GC exhibited decreasing saliva volumes with increasing compressive strength (P <0.001). Conversely, the opposite was observed for AU (P = 0.019). The study suggests that the consistency or compressive strength of paraffin wax chewing gums from different manufacturers could impact sSFR.


Assuntos
Goma de Mascar , Parafina , Saliva , Humanos , Feminino , Masculino , Adulto , Saliva/química , Força Compressiva/fisiologia , Mastigação/fisiologia , Adulto Jovem , Pessoa de Meia-Idade , Taxa Secretória/fisiologia , Taxa Secretória/efeitos dos fármacos
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