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Summary: Analyses of leaf gas exchange rely on an Ohmic analogy that arrays single stomatal, internal air space, and mesophyll conductances in series. Such models underlie inferences of mesophyll conductance and the relative humidity of leaf airspaces, reported to fall as low as 80%. An unresolved question is whether such series models are biased with respect to real leaves, whose internal air spaces are chambered at various scales by vasculature.To test whether unsaturation could emerge from modeling artifacts, we compared series model estimates with true parameter values for a chambered leaf with varying distributions and magnitudes of leaf surface conductance ('patchiness').Distributions of surface conductance can create large biases in gas exchange calculations. Both apparent unsaturation and internal CO2 gradient inversion can be produced by the evolution of broader distributions of stomatal apertures consistent with a decrease in surface conductance, as might occur under increasing vapor pressure deficit.In gas exchange experiments, the behaviors of derived quantities defined by simple series models are highly sensitive to the true partitioning of flux and stomatal apertures across leaf surfaces. New methods are needed to disentangle model artifacts from real biological responses. [ABSTRACT FROM AUTHOR]

Salt stress on green microalgae increases lipid production at the cost of cellular homeostasis. Rapid optimization of growth conditions for high lipid productivity and biomass yield is crucial for translation to industrial-scale biodiesel production. To achieve this, the present study has developed a spectroscopic non-invasive analysis of lipid molecules produced by Chlamydomonas reinhardtii in two-stage salt stress, wherein 100 mM NaCl was added at two different time points: day 2 (D2 100) and day 4 (D4 100) of growth. Two-stage stress resulted in cell morphology like the photoautotrophic control grown in normal conditions, with negligible palmelloid formation in contrast to single-stage. Raman spectra acquired from ~ 30 individual cells in each culture revealed heterogeneities in lipid composition. Discrete wavelet transform decomposition of the Raman signal was used to enhance the signal-to-noise ratio and accuracy of Raman peak center estimation. An overall increase in heterogeneity indices for fatty acid degree of unsaturation was observed under two-stage salt stress: fourfold for D2 100 and ninefold for D4 100, especially at the stationary growth phase. The ratio of the CH2/CH3 scissoring mode (1440 cm−1) and the C = O stretching mode (1750 cm−1) reveals the shortening of fatty acid chain length in D4 100. Although Raman bands of lipids formed in all growth conditions are on average like Triolein (18:1), analyses of the degree of unsaturation (1656/1440 cm−1) clarify the increased content of bi and tri-unsaturation only in D4 100. This non-invasive lipid profiling reveals that D4 100 is likely a non-ideal condition to obtain high-quality biodiesel-producing lipids. A comparative analysis of single-cell fluorescence microscopy of lipid droplets and Raman intensity of lipids shows the sensitivity of Raman intensity in deciphering the relative response of the cells to salt stress. [ABSTRACT FROM AUTHOR]

We consider the compact set of -smooth periodic functions in a Gevrey class that admits a bounded embedding into the space of continuous functions on the unit circle. We describe the asymptotic behavior of Alexandrov's -width of this compact set. [ABSTRACT FROM AUTHOR]

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A fundamental assumption in plant science posits that leaf air spaces remain vapor saturated, leading to the predominant view that stomata alone control leaf water loss. This concept has been pivotal in photosynthesis and water-use efficiency research. However, recent evidence has refuted this longstanding assumption by providing evidence of unsaturation in the leaf air space of C3 plants under relatively mild vapor pressure deficit (VPD) stress. This phenomenon represents a nonstomatal mechanism restricting water loss from the mesophyll. The potential ubiquity and physiological implications of this phenomenon, its driving mechanisms in different plant species and habitats, and its interaction with other ecological adaptations have. In this context, C4 plants spark particular interest for their importance as crops, bundle sheath cells' unique anatomical characteristics and specialized functions, and notably higher water-use efficiency relative to C3 plants. Here, we confirm reduced relative humidities in the substomatal cavity of the C4 plants maize, sorghum, and proso millet down to 80% under mild VPD stress. We demonstrate the critical role of nonstomatal control in these plants, indicating that the role of the CO2 concentration mechanism in CO2 management at a high VPD may have been overestimated. Our findings offer a mechanistic reconciliation between discrepancies in CO2 and VPD responses reported in C4 species. They also reveal that nonstomatal control is integral to maintaining an advantageous microclimate of relatively higher CO2 concentrations in the mesophyll air space of C4 plants for carbon fixation, proving vital when these plants face VPD stress. [ABSTRACT FROM AUTHOR]

Plant fatty acids (FAs) are critical components of lipids and play an important role in coping with pollution-induced stress. However, the relationship between the fluctuating changes of FAs and the toxic effects of pollutants is not clear. Here, we analyzed and identified 19 FAs, namely 14 medium and long chain fatty acids (MLCFAs) and 5 very long chain fatty acids (VLCFAs). First, a positive correlation between plant biomass and LCFA content was observed. Changes in unsaturation were inversely related to cell membrane permeability, which serves as an indicator of the toxic effects. In particular, the use of herbicides led to a reduction in total FA content, but caused a significant increase in free fatty acids (FFAs), which facilitate oxidative stress. In addition, supplementation with exogenous FAs, particularly linoleic and alpha-linolenic acids, effectively alleviated the toxic inhibition. (R)-dichlorprop causes abnormal FA metabolism that can be reversed by ferrostatin-1, a ferroptosis inhibitor. Under (R)-dichlorprop exposure, the balance of FA unsaturation in plants is disrupted by inhibition of FA desaturase activity, ultimately leading to ferroptosis and disruption of cell membrane integrity. This study aims to enhance the understanding of the ecotoxic effects of herbicides by examining changes in FAs. The findings will provide a scientific basis for controlling environmental risks associated with hazardous substances. [ABSTRACT FROM AUTHOR]

Atomically precise nanoclusters hold promise for supramolecular assembly and (opto)electronic‐ as well as magnetic materials. Herein, this work reports that treating palladium(0) precursors with a triphosphirane affords strongly colored Pd8(PDip)6 that is fully characterized by mass spectrometry, heteronuclear and Cross‐Polarization Magic‐Angle Spinning (CP‐MAS) NMR‐, infrared (IR), UV–vis, and X‐ray photoelectron (XP) spectroscopies, single‐crystal X‐Ray diffraction (sc‐XRD), mass spectrometry, and cyclovoltammetry (CV). This coordinatively unsaturated 104‐electron Pd(0) cluster features a cubic Pd8‐core, µ4‐capping phosphinidene ligands, and is air‐stable. Quantum chemical calculations provide insight to the cluster's electronic structure and suggest 5s/4d orbital mixing as well as minor Pd─P covalency. Trapping experiments reveal that cluster growth proceeds via insertion of Pd(0) into the triphosphirane. The unsaturated cluster senses ethylene and binds isocyanides, which triggers the rearrangement to a tetrahedral structure with a reduced frontier orbital energy gap. These experiments demonstrate facile cluster manipulation and highlight non‐destructive cluster rearrangement as is required for supramolecular assembly. [ABSTRACT FROM AUTHOR]

Leaf gas-exchange measurements are useful in assessing plant environmental responses. However, uncertainties in the leaf gas-exchange model potentially limit its application. The main challenge in the model-dependent calculations is to detect violations of assumptions. Here, we developed a system that integrates into one instrument the direct measurement of leaf intercellular CO2 concentration and the standard open-flow (OF) and novel open-diffusion (OD) systems for flux measurement. In the OD system, a gas-permeable membrane between the leaf ambient air and outside air creates CO2 and H2O differentials, rather than the air flow in the OF chamber. We measured hypostomatous and amphistomatous leaves of several species with different photosynthetic capacities [sunflower (Helianthus annuus), grape (Vitis vinifera), lemon (Citrus limon), and cherry (Prunus avium)]. The CO2 and H2O differentials in the OD system strictly depend on the flux measured by the OF system. The lower permeability of the membrane resulted in a larger differential per flux, indicating that the OD system can increase the resolution for a small flux. An analysis of the conductance model along with observations suggested that cuticle and leaf intercellular conductances and the unsaturation of leaf humidity contributed to discrepancies between the direct measurement and standard calculation. The combined system developed here provides an opportunity to address these overlooked concepts in leaf gas exchange. [ABSTRACT FROM AUTHOR]

Although it is important to understand the factors affecting the physical properties of oleogels for their application in food products, the effects of the kind of oils and components in them are not well understood. Previous studies on the effects of unsaturation and polar compounds of oils on the properties of oleogels reported inconsistent results, presumably, due to different gelling agents, experimental conditions, and different amounts of minor components in oils. In this study, a systematic study was conducted with 12 vegetable oils with and without polar compounds to understand these effects on the properties of 3% and 7% sunflower wax (SW)‐oleogels. In general, oils with higher unsaturation produced oleogels with lower gel strength. Polar compounds in oil negatively affected the gel strength. Melting and crystallization temperatures increased with increasing unsaturation of oil. The platelet shape of SW crystals was almost identical, regardless of the kind of oil. Solid wax content values were similar across the oleogel samples with 12 different oils. This study enlightens several factors affecting the physical properties of SW‐oleogels. Practical Application: This study provides information about the effects of unsaturation of oil and polar compounds in oil on firmness and melting properties of sunflower wax (SW)‐based oleogels. It was found that the firmness of SW‐oleogel can be significantly different (up to 65%) depending on vegetable oils used, and it decreased with increasing unsaturation of oil. It was also found that the firmness of the oleogel can be increased by up to 36% by removing polar compounds in oil. Solid wax content (SWC) of oleogels did show meaningful correlations with the firmness of SW‐oleogels. All the oleogels examined in this study had very similar shapes and sizes of SW crystals. For practical application, the unsaturation of oil and the polar compound content have to be considered when designing oleogels with desired textural properties. [ABSTRACT FROM AUTHOR]

Biodiesel is a mixture of saturated and unsaturated Fatty Acid Methyl Esters (FAMEs) whose composition affects the corrosion behavior of metal containers during storage. This study examines the effect of the C=C bond present in selected FAMEs (Methyl Stearate, Methyl Oleate, and Methyl Linoleate) in aluminum corrosion in the absence of oxygen. First, mass loss assays were carried out at 100, 200, and 280 °C for 1000 h using pure Methyl Stearate (MS), 5% Methyl Oleate in Methyl Stearate (MS-5% MO), and 5% Methyl Linoleate in Methyl Stearate (MS-5% ML). Next, chemical changes in FAMEs were studied using FTIR, TGA, and GC/MS. SEM/EDS analysis allowed us to inspect the aluminum surfaces and their chemical characterization. We estimated higher corrosion rates for MS assays than those of unsaturated methyl ester mixtures. In a separate set of experiments, we used electrochemical techniques (potentiodynamic polarization, linear polarization resistance, and electrochemical impedance spectroscopy) to investigate aluminum corrosion induced by thermal-degraded products from FAMEs at 100, 200, and 280 °C for 300 h able to dissolve in aqueous extracts. These electrochemical experiments revealed that the products in the aqueous extracts from the unsaturated methyl ester mixture form a passive layer on the Al surface thicker than pure MS at the corresponding degradation temperatures. [ABSTRACT FROM AUTHOR]

Summary: Chlorogenic acid (CGA) was modified using acyl chlorides with different levels of unsaturation (C18:0–C18:3) to enhance the lipophilicity and promote its application. The antioxidant activity of CGA derivatives in food and biological models was evaluated. All CGA derivatives had significantly greater antioxidative activity than CGA in fish oil and β‐carotene/linoleic acid emulsions (P < 0.05), but there was no linear relationship between antioxidative activity and unsaturation. The effectiveness of CGA‐C18:0 was significantly greater than that of CGA in scavenging H2O2 and reducing copper‐induced human low‐density lipoprotein (LDL) oxidation (P < 0.05). Furthermore, the H2O2 scavenging activity, inhibitions of copper‐induced human LDL oxidation and hydroxyl or peroxyl radical‐induced DNA oxidation were all linearly related to the unsaturation of the alkyl chains, mainly with the free radical chain reactions of the unsaturated bonds. Our findings showed that CGA derivatives could potentially be used as antioxidants in food and biological systems. [ABSTRACT FROM AUTHOR]

Converting biomass materials to humic acid is a sustainable method for humic acid production and achieve biomass valorization. A two-step hydrothermal treatment method was adopted in this study to produce humic acid from corn stalks. In the first step of the process, hydrochar was prepared at different hydrothermal temperatures and pH values. Their chemical properties were then analyzed, and the hydrochar-derived humic acids were produced under alkaline hydrothermal conditions (denoted as HHAalk). The hydrochar, prepared under high temperature (200 °C) and strong acidic (pH 0) conditions, achieved high HHAalk yields (i.e., 67.9 wt% and 68.8 wt% calculated based on weight of hydrochar). The sources of HHAalk formation were as follows: 1) production in the hydrochar preparation stage, and 2) increment under the alkaline hydrothermal treatment of hydrochar. The degree of hydrochar unsaturation was suggested as an indicator for evaluating the hydrochar humification potential under alkaline hydrothermal conditions. This study provides an important reference for the preparation of suitable hydrochar with high hydrothermal humification potential. [ABSTRACT FROM AUTHOR]

The Rouse formula and its variants have been widely used to describe the vertical distribution of the sediment concentration in sediment-laden flows in equilibrium. Han's formula extends the Rouse formula to non-equilibrium regimes, where the diffusive flux is still assumed to be Fickian. The turbulent flow and suspension regimes downstream of a mega-reservoir, e.g., the Three Gorges Reservoir, usually exhibit fractal and unsaturated properties, respectively. To characterize the non-Fickian dynamics of suspended sediment and the non-equilibrium regime in natural dammed rivers, this study proposes a new formula for the concentration profile of unsaturated sediment based on the Hausdorff fractal derivative advection–dispersion equation. In addition, we find that the order of the Hausdorff fractal derivative is related to the sizes of the sediment and the degrees of non-equilibrium. Compared to Rouse and Han's formulae, the new formula performs better in describing the sediment concentration profiles in the Jingjiang Reach, approximately 100 km below the Three Gorges Dam. [ABSTRACT FROM AUTHOR]

The study was carried out to investigate the effect of storage time at ambient temperature on pH and iodine value of palm oil and groundnut oil using appropriate standard methods. The iodine value of palm oil decreased from 45.69 ± 0.01a to 45.11± 0.00k while that for groundnut oil decreased from 56.72 ± 0.01a to 56.22 ± 0.01k during the period of storage indicating loss of unsaturation due to oxidation. On the other hand, the pH of both palm and groundnut oils showed a more impressive decrease from 6.85 ± 0.05a to 4.19 ± 0.00j and 6.40 ± 0.00a to 4.40 ± 0.00h ., respectively, due to autoxidation of the oils. A trend of decreasing order of iodine and pH value as the number of days of storage increases for both oils (palm and groundnut oil) was observed. This study shows that the storage time has a high significant effect on the iodine Value and pH value of both oil (palm and groundnut oil) with p ˂ 0.00 as against p ≤ 0.05. It was also observed that there was loss of unsaturation in both oils but higher in palm oil. However, groundnut oil had a higher iodine value, implying that groundnut oil had more of unsaturated fatty acid than palm oil which tends towards saturation due to high level of decreasing iodine value. However, from literature, it has been stated that groundnut oil is likely to be healthier for consumption due to the presence of unsaturated fat it contains. [ABSTRACT FROM AUTHOR]

The effect of oleogels prepared using γ-oryzanol, β-sitosterol and vegetable oils with different unsaturation on the gel properties of surimi was compared. The findings from SEM and optical microscopy demonstrated that direct addition of vegetable oils caused loose surimi gel three-dimensional network structure, which negatively impacted the water holding capacity (WHC) and texture properties. However, oleogels increased the hydrophobic interaction and disulfide bond content, facilitated the transition from α-helix to β-sheet, improving the WHC and gel strength of surimi. Among them, the surimi containing oleogels prepared by linseed oil with the highest polyunsaturated fatty acid (PUFA) content had the highest gel strength and WHC, which were 3936.067 g·mm and 66.77 %, respectively. The results of microstructure showed that linseed oil based oleogels were able to fill the gaps of gel network more uniformly with smaller holes. Therefore, oleogels enriched with PUFA were more effective in enhancing the gel properties of surimi. [Display omitted] • Oleogels improved negative impact of vegetable oils on gel properties of surimi • Oleogels contributed to protein interactions and transition from α-helix to β-sheet • Oleogels enriching polyunsaturated fatty acids is best for enhancing gel properties [ABSTRACT FROM AUTHOR]

The study was carried out to investigate the effect of storage time at ambient temperature on pH and iodine value of palm oil and groundnut oil using appropriate standard methods. The iodine value of palm oil decreased from 45.69 ± 0.01a to 45.11± 0.00k while that for groundnut oil decreased from 56.72 ± 0.01a to 56.22 ± 0.01k during the period of storage indicating loss of unsaturation due to oxidation. On the other hand, the pH of both palm and groundnut oils showed a more impressive decrease from 6.85 ± 0.05a to 4.19 ± 0.00j and 6.40 ± 0.00a to 4.40 ± 0.00h., respectively, due to autoxidation of the oils. A trend of decreasing order of iodine and pH value as the number of days of storage increases for both oils (palm and groundnut oil) was observed. This study shows that the storage time has a high significant effect on the iodine Value and pH value of both oil (palm and groundnut oil) with p ˂ 0.00 as against p ≤ 0.05. It was also observed that there was loss of unsaturation in both oils but higher in palm oil. However, groundnut oil had a higher iodine value, implying that groundnut oil had more of unsaturated fatty acid than palm oil which tends towards saturation due to high level of decreasing iodine value. However, from literature, it has been stated that groundnut oil is likely to be healthier for consumption due to the presence of unsaturated fat it contains.

This study investigates the impact of interruption of injections on the transfer and retention of suspended particles (SP) in granular media. Columns packed with sand were operated in the laboratory, and a series of experiments of SP injections were conducted: the first by injecting SP without interrupting injection, the second and third experiments with 3 pauses of injection of 24 h and 48 h, respectively. Results showed that interrupted injections induced a significant release of particles showing peaks of concentration in the effluent immediately after the pause periods. These peaks increase with pause durations. Interruption of injections allowed the transport of coarser particles deeper into the columns. For all experiments carried out, the hydraulic conductivity, measured during injection, decreased with the number of pore volumes injected. This decrease is almost linear for continuous injection experiments. Whereas, the hydraulic conductivity decreased brutally when reinjecting SP, after pauses, highlighting the desaturation of the porous medium during pause periods. The results obtained show that all the phenomena (hydraulic conductivity drop, SP transport, and deeper transfer of coarser particles) occurred during the dynamic phase of the experiments for the first 75% of pore volumes injected. Beyond that, the porous medium is completely clogged. [ABSTRACT FROM AUTHOR]

The main objective of this paper is studying the behaviour of dense RF Hostun sand subjected to dynamic loading in the triaxial apparatus. The samples with the same initial conditions (water content, void ratio) were prepared by the wet tamping method. After that, the samples were saturated, and then an effective cell pressure of 100 kPa was used to consolidate the sample. To study the liquefaction behaviour of sand, all the samples were subjected to dynamic deviator loading until liquefaction. The experiments show that the cyclic stress ratio needed to liquefy the sample was significantly affected by the saturation degree. All saturated samples were liquefied by the same level of deviator stress; however, the cycle numbers needed to liquefy the samples are different. The results suggest that besides the void ratio and the saturation degree, the sand liquefaction susceptibility may be affected by the different soil fabrics caused by sample preparation technique. [ABSTRACT FROM AUTHOR]

Cold stress breeding that focuses on the improvement of chilling tolerance at the germination stage is constrained by the complexities of the trait which involves integrated cellular, biochemical, hormonal and molecular responses. Biological membrane serves as the first line of plant defense under stress. Membranes receive cold stress signals and transduce them into intracellular responses. Low temperature stress, in particular, primarily and effectively affects the structure, composition and properties of cell membranes, which ultimately disturbs cellular homeostasis. Under cold stress, maintenance of membrane integrity through the alteration of membrane lipid composition is of prime importance to cope with the stress. This review describes the critical role of cell membranes in cold stress responses as well as the physiological and biochemical manifestations of cold stress in plants. The potential of cell membrane properties as breeding targets in developing strategies to improve cold germination ability is discussed using cotton (Gossypium hirsutum L.) as a model. [ABSTRACT FROM AUTHOR]

High‐energy lithium‐ion batteries (LIBs) can be realized with the use of nickel‐rich materials, however, their reversible operation requires long‐term cathode‐electrolyte interfacial (CEI) stability, especially for high‐temperature applications, but how the CEIs evolves during operation is still a mystery. The unstable CEIs have been recently ascribed to them generating/disappearing/regenerating during Li+ extraction/insertion by in situ Fourier Transform Infrared Spectroscopy spectrum. Herein, a strategy of insoluble CEI is proposed toward addressing the interfacially induced deterioration of cathodes with a focus on Ni‐rich layered oxides. Incorporating unsaturated units (CC/CC) to siloxane as electrolyte additives advances the commercial LiNi0.8Co0.1Mn0.1O2/graphite cells up to around 300 cycles at 60 °C with more than 85% capacity retention, along with the LiCoO2 cells reaching ≈90% capacity retention over 350 cycles under 80 °C. The experimentally and theoretically detailed investigation shows that the higher unsaturation bond with high reactive sites show more polymerization via a 3D topological pathway to form insoluble CEI species, leading to suppression of parasitic reactions, corrosive acid, transition‐metal dissolution, stress corrosive cracking, and impedance growth. The scientific discoveries of this study highlight the pivotal role of electrode–electrolyte interactions and recapitulates the tried‐and‐true "electrolyte" approach for the future development of high‐energy batteries under extreme temperature conditions. [ABSTRACT FROM AUTHOR]

Recently, it has been reported that combinations of various types of vegetable oils containing organic acids and DLC coatings are effective for reducing friction, but there are few reports of detailed investigations into the relationship between differences in the chemical structures of vegetable oil lubricants and friction reduction. Therefore, the authors investigated the influence on friction properties of two types of DLC coatings, a-C:H and ta-C under lubrication with vegetable oils which have different degrees of unsaturation. The ta-C coating displayed markedly lower friction coefficients than the a-C:H coating and the uncoated steel with all of the vegetable oil lubricants used. It was found that the low friction properties of the ta-C coating showed even lower friction coefficients with vegetable oils containing a higher content of monounsaturated fatty acids. Additionally, the sliding surfaces of ta-C coated discs and cylinders were analyzed by XPS and ToF-SIMS analysis. The results confirmed the formation of a surface layer consisting of C-OH bonds, and a lower friction coefficient was seen as the detected intensity of these bonds increased.

Glioblastoma is the most common and lethal primary malignant brain tumor in adults. Glioblastoma stem cells (GSCs) promote and are responsible for glioblastoma intratumoral heterogeneity and therapy resistance, due to their two main features: self-renewal and differentiation. Lipids have important biological and physiological functions that are critical for understanding the regulation and control of stem cell fate; lipid metabolism and related unsaturation levels play a possible role as the target of therapeutics to overcome glioblastoma radioresistance. This paper aimed at an in-depth analysis of 13 GSC mesenchymal (MES) lines, two subclones, and a stabilized glioblastoma line (T98G) by magnetic resonance spectroscopy (MRS). Particularly, 2D MRS was used to investigate lipid unsaturation behavior during growth in culture and after treatment with etomoxir and photon beams. MES lines, although belonging to the same genetic and metabolic cluster, showed metabolic heterogeneity when observed by MRS, focusing on lipid signals. Nonetheless, the observed unsaturation level stability for two representative lines after stressful treatments suggests unusual robustness of the unsaturation levels for each line, as a peculiar and intrinsic characteristic of GSCs. [ABSTRACT FROM AUTHOR]

To explore mechanic texture of sand landslide, a centrifuge modelling test device for rainfall induced landslide was developed to carry out coarse sand centrifuge model test. Based on the test results, the improved discrete element numerical simulation program was used to study the meso scale process of landslide, and the centrifuge model test was supplemented from the perspective of meso scale and discontinuity. The results show that: the meso mechanism of coarse sand landslide is that the water in the slope cannot be discharged in time, resulting in the soil particles suspended in the water particles, the contact between the soil particles is reduced or even separated, the interaction between the soil particles is transformed into the interaction between the soil particles and the water particles, the fluid characteristics of the soil appear, and the shear strength is lost. There are two possible forms of landslide development: the force exerted by the water particles on the soil particles is exactly equal to the contact force of the soil particles at this position, which shows the overall sliding. The force exerted by the water particles on the soil particles is equal to the sum of the gravity of the soil particles and the contact force of the front soil particles, which shows that the rear landslide develops forward. [ABSTRACT FROM AUTHOR]

Short‐term hypobaric treatment (SHT) on postharvest quality and membrane fatty acids metabolism were studied in peach fruit (Prunus persica [L.] Batsch., cv. Feicheng) during shelf life after cold storage. SHT was effective in alleviating chilling injury (CI) and maintaining postharvest quality. SHT reduced the production of malondialdehyde (MDA) and electrolyte leakage (EL), and increased membrane fluidity. In addition, SHT plays an imperative role in reducing saturated fatty acid (SFA), increasing unsaturated fatty acid (USFA), and keeping a higher unsaturation level in peach fruit. Meanwhile, SHT enhanced the activity of fatty acid synthetase (FAS), upregulated the expression levels of FAD2, FAD3‐1, FAD3‐2, and FAD7 genes at the early stage of storage, as well as inhibited the activity of lipoxygenase (LOX) and gene expression of LOX1. These results suggested that SHT could increase fatty acids unsaturation by regulating FAS activity, FAD and LOX1 gene expression, thus maintain high membrane stability and alleviate CI. Practical applications: CI is an important factor affecting the postharvest quality of peaches in cold storage, and metabolism of membrane fatty acids is one of the main CI response mechanisms. Our previous study has shown that SHT could alleviate CI in peach fruit. Therefore, it is of great significance to investigate the regulation of membrane fatty acids metabolism under SHT. Results from this study suggest that the enhancement of chilling tolerance by SHT in peaches could be explained, at least in part, as being due to enhanced FAS activity, upregulated the expression of FAD gene, and inhibited LOX1 to maintain higher unsaturation level. All in all, we explored the response mechanism of membrane fatty acids metabolism under SHT in peach fruit, and supplied theoretical guidance for application of the technology. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of four fatty acids with the same carbon-chain length and different saturations, stearic acid (SA), oleic acid (OA), linoleic acid (LA), and linolenic acid (LNA), on the growth performance and muscle quality of Megalobrama amblycephala through in vivo and in vitro experiments. A total of 320 fish with similar initial weight (34.97 ± 0.14 g) were randomly fed 3% four kinds of 18-carbon fatty acids with different carbon saturation. Growth performance was assessed at the end of the feeding trial, and samples were collected for the corresponding indicators. Results showed that the weight gain rate (WGR) and specific growth rate (SGR) of unsaturated fatty acids groups were significantly increased (P

Biodiesel properties are in general attributed to the composition and properties of the oil feedstock used, overlooking the possible impacts of the catalyst preparation details. In light of that, the impacts of different catalyst preparation techniques alongside those of different support materials on the yield, composition, and fuel properties of biodiesels produced from the same oil feedstock were investigated. More specifically, tri-metallic (Fe-Co-Ni) catalyst was synthesized through two different techniques (green synthesis and wet impregnation) using MgO or ZnO as support material. The generated catalyst pairs, i.e., Fe-Co-Ni/MgO and Fe-Co-Ni/ZnO prepared by wet impregnation and Fe-Co-Ni-MgO and Fe-Co-Ni-ZnO prepared by green synthesis (using leaf extracts) were used in the transesterification process of Jatropha curcas oil. Detailed morphological properties, composition, thermal stability, crystalline nature, and functional groups characterization of the catalysts were also carried out. Using Box-Behnken Design response surface methodology, it was found that the green-synthesized Fe-Co-Ni-MgO catalyst resulted in the highest biodiesel yield of 97.9%. More importantly, the fatty acid methyl ester (FAME) profiles of the biodiesels produced using the four catalysts as well as their respective fuel properties were different in spite of using the same oil feedstock.

Oleogelation is emerging as one of the most exigent oil structuring technique. The main objective of this study was to formulate and characterize rice bran/ sunflower wax-based oleogels using eight refined food grade oils such as sunflower oil, mustard oil, soybean oil, sesame oil, groundnut oil, rice bran oil, palm oil, and coconut oil. Stability and properties of these oleogels with respect to oil unsaturation and wax composition were explored. Sunflower wax exhibited excellent gelation ability even at 1%–1.5% (w/v) concentration compared to rice bran wax (8%–10% w/v). As the oleogelator concentration increased, peak melting temperature also increased with increase in strength of oleogels as per rheological studies. X-ray diffraction and morphological studies revealed that oleogel microstructure has major influence of wax composition only. Sunflower wax oleogels unveiled rapid crystal formation with maximum oil binding capacity of 99.46% in highly unsaturated sunflower oil with maximum polyunsaturated fatty acid content. Further, the applicability of this wax based oleogels as solid fat substitute in marketed butter products was also scrutinized. The lowest value of solid fat content (SFC) in oleogel was 0.20% at 25oC, resembling closely with the marketed butter products. With increase in oil unsaturation, oleogels displayed remarkable reduction in SFC. Depending upon prerequisite, oleogel properties can be modulated by tuning wax type and oil unsaturation. In conclusion, this wax-based oleogel can be used as solid fat substitute in food products with extensive applications in other fields too. [ABSTRACT FROM AUTHOR]

Cold stress breeding that focuses on the improvement of chilling tolerance at the germination stage is constrained by the complexities of the trait which involves integrated cellular, biochemical, hormonal and molecular responses. Biological membrane serves as the first line of plant defense under stress. Membranes receive cold stress signals and transduce them into intracellular responses. Low temperature stress, in particular, primarily and effectively affects the structure, composition and properties of cell membranes, which ultimately disturbs cellular homeostasis. Under cold stress, maintenance of membrane integrity through the alteration of membrane lipid composition is of prime importance to cope with the stress. This review describes the critical role of cell membranes in cold stress responses as well as the physiological and biochemical manifestations of cold stress in plants. The potential of cell membrane properties as breeding targets in developing strategies to improve cold germination ability is discussed using cotton (Gossypium hirsutum L.) as a model.

Soil is typically unsaturated, with water films covering the soil particles playing a crucial role in soil mechanics, structure, and element transport. However, the unusual behavior of these water films and the underlying mechanisms are not yet fully understood. This study, which used molecular dynamics methods, sheds light on the distinct interactions between water films and clay surfaces under unsaturation. At the water-mineral interface, water molecules formed a layered structure, while they rearranged as a meniscus as the unsaturation extent increased. On the other hand, unsaturation had a significant impact on the location of water molecules at the water-vapor interface, but only a limited effect at the water-mineral interface. The water's orientational ordering and hydrogen bonding interactions were significantly affected by changes in relative humidity (RH). Based on the distance-dependent diffusion coefficient, the water molecules within the water film were classified into three types: WT1 (< 5 Å) had faster diffusivity at higher RH , WT2 (5–6 Å) had comparable diffusivity at any RH , and WT3 (> 6 Å) had faster diffusivity at intermediate RH. This classification was supported by the retention dynamics analysis. The specific behaviors mentioned above, which are associated with unsaturation, are closely linked to Na+ hydration. This is because the interaction between water and Na+ is more pronounced than the interaction between water and minerals or Cl−. The results indicate that unsaturation triggers specific adsorption behaviors of water films that cover the clay surfaces. These behaviors should be considered in interfacial processes and environmental engineering. [Display omitted] • Wettability and adsorption are significantly different in clay particles under non-saturation. • Three types of water molecules are classified according to the diffusion and retention behaviors. • "Transmission effect" passes from the water-vapor to the water-clay interface. • Cation hydration controls the specific performance of water films in unsaturated condition. [ABSTRACT FROM AUTHOR]

• Average molar mass and unsaturation in FAME and BD estimated by Inverse QSPR (IQSPR). • Molecular parameters averages estimated from refractive index and speed of sound data. • Averages of molecular parameters obtained from explicit solutions of IQSPR equations. • IQSPR method may be extended to other pure substances or mixtures. Quantitative Structure-Properties Relationships (QSPR) are widely used for the prediction of physical and chemical properties in many pure substances. They have also been successfully applied to liquid mixtures, such as fatty acid methyl esters and biodiesel of known molecular composition. For these substances, we propose that molar averages of the number of carbon atoms and double bonds in the methyl ester molecules are relevant parameters for QSPR estimations. In this work, we define a system of Inverse QSPR (IQSPR) to estimate the molar averages of carbon chain length, number of double bonds, and molar mass of fatty acid methyl esters, biodiesel, and blends from refractive index and speed of sound measurements. The comparison with chromatography data for saturated and unsaturated fatty acid methyl esters, with a chain length between 8 and 18 carbon atoms, and biodiesel samples from different feedstock, shows that the relative difference in the estimation of the molar mass is lower than 2.1 %. The difference (absolute value) between the estimated and experimental molar averages of chain length and number of double bonds per ester molecule are less than 0.34 and 0.14, respectively. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phytosterols are partly removed during oil refining, and the magnitude of phytosterols loss largely depends on the refining conditions applied and the molecular conformation. The aim of this research was to study the effect of deodorization conditions and molecular unsaturation on the esterification of phytosterols during deodorization of corn oil. RESULTS: In the chemical model, free fatty acids (FFAs) were the major provider of acyl groups during the formation of phytosteryl fatty acid esters (PEs) under deodorization conditions. Among the main parameters of the deodorization, temperature played a role in the formation of PEs with a time‐dependent manner. In comparison, saturated palmitic acid had a higher capability of esterifying free phytosterols (FPs) to PEs than unsaturated oleic acid and linoleic acid. Moreover, the influence of FFA unsaturation on the degradation of FPs depended on temperature. Besides, the formation of stigmasteryl ester had a competitive advantage over that of sitosteryl ester by quantum chemistry simulation. CONCLUSION: For laboratory‐scale deodorization of corn oil, saturated fatty acids and deodorization process with steam as stripping gas could obviously esterify FPs to PEs. FPs were abundantly enriched in distillate during the deodorization process with nitrogen as stripping gas, whereas FPs and PEs were distilled simultaneously during the deodorization process with steam. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This study aims to investigate the influence of high‐intensity sunlight radiation on the photooxidation of tropical oils (TO). Coconut oil (CNO), palm oil (PO), and palm kernel oil (PKO) were chosen for determining the indicators of photooxidation when exposed to and in the absence of sunlight for 7 weeks. The results showed a significant (P < 0.05) increase in free fatty acid (FFA) levels and peroxide value (PV) when the TO were exposed to sunlight. The iodine value and color content decreased significantly (P < 0.05) due to the decomposition of unsaturated FFA owing to the breaking down of the π‐bonds and the degradation of color pigments during photooxidation. Fourier transform infrared spectroscopy (FTIR) analysis showed strong vibrational absorptions at 1721 and 3505 cm−3, 1720 and 3560 cm−3, and 1721 and 3554 cm−3 for the CNO, PO, and PKO samples exposed to sunlight, respectively. These bands can be attributed to the presence of secondary oxidation products, which were absent in the TO that were not exposed to sunlight. A simulation was performed to support the FTIR results, which also indicated peaks from the secondary oxidation products at 1744 and 3660 cm−3. The study also revealed that the rate of photooxidation was different for each TO. The rate of oxidation followed the order PO > PKO > CNO. In contrast, no notable changes were observed in the TO kept away from sunlight. These results suggest that exposing TO to sunlight influences their oxidation stability and quality. [ABSTRACT FROM AUTHOR]

Summary: Canonical fatty acid metabolism describes specific enzyme-substrate interactions that result in products with well-defined chain lengths, degree(s), and positions of unsaturation. Deep profiling of lipids across a range of prostate cancer cell lines reveals a variety of fatty acids with unusual site(s) of unsaturation that are not described by canonical pathways. The structure and abundance of these unusual lipids correlate with changes in desaturase expression and are strong indicators of cellular phenotype. Gene silencing and stable isotope tracing demonstrate that direct Δ6 and Δ8 desaturation of 14:0 (myristic), 16:0 (palmitic), and 18:0 (stearic) acids by FADS2 generate new families of unsaturated fatty acids (including n-8, n-10, and n-12) that have rarely—if ever—been reported in human-derived cells. Isomer-resolved lipidomics reveals the selective incorporation of these unusual fatty acids into complex structural lipids and identifies their presence in cancer tissues, indicating functional roles in membrane structure and signaling.

Abstract Background Soybean oil constitutes an important source of vegetable oil and biofuel. However, high temperature and humidity adversely impacts soybean seed development, yield, and quality during plant development and after harvest. Genetic improvement of soybean tolerance to stress environments is highly desirable. Results Transgenic soybean lines with knockdown of phospholipase Dα1 (PLDα1KD) were generated to study PLDα1′s effects on lipid metabolism and seed vigor under high temperature and humidity conditions. Under such stress, as compared with normal growth conditions, PLDα1KD lines showed an attenuated stress-induced deterioration during soybean seed development, which was associated with elevated expression of reactive oxygen species-scavenging genes when compared with wild-type control. The developing seeds of PLDα1KD had higher levels of unsaturation in triacylglycerol (TAG) and major membrane phospholipids, but lower levels of phosphatidic acid and lysophospholipids compared with control cultivar. Lipid metabolite and gene expression profiling indicates that the increased unsaturation on phosphatidylcholine (PC) and enhanced conversion between PC and diacylglycerol (DAG) by PC:DAG acyltransferase underlie a basis for increased TAG unsaturation in PLDα1KD seeds. Meanwhile, the turnover of PC and phosphatidylethanolamine (PE) into lysoPC and lysoPE was suppressed in PLDα1KD seeds under high temperature and humidity conditions. PLDα1KD developing seeds suffered lighter oxidative stresses than did wild-type developing seeds in the stressful environments. PLDα1KD seeds contain higher oil contents and maintained higher germination rates than the wild-type seeds. Conclusions The study provides insights into the roles of PLDα1 in developing soybean seeds under high temperature and humidity stress. PLDα1KD decreases pre-harvest deterioration and enhances acyl editing in phospholipids and TAGs. The results indicate a way towards improving production of quality soybean seeds as foods and biofuels under increasing environmental stress.

In this short review, we introduce various aspects of insect body lipids, which have been progressively found to have many crucial physiological roles. The body-surface of insects is covered with cuticular lipids, mainly hydrocarbons. The cuticular hydrocarbons are synthesized in specialized cells called oenocytes residing beneath the epidermis. The hydrocarbons synthesized are transported to the outermost layer, wax layer, by the circulating lipoprotein, lipophorin. Although the principal role of the wax layer is the protection of internal body from desiccation, the essential features vary depending on insect species and development stage. The diapausing pupae of large and small cabbage white butterflies change the thickness and unsaturation of their cuticular hydrocarbons from their non-diapausing ones. The cuticular hydrocarbons also contribute to chemical communications. The unsaturated hydrocarbons of male crickets play an important role for sex discrimination before copulation. Modern in-situ surface analytical methods have a potential to provide more abundant and precise information about the structure and physicochemical properties of the cuticular hydrocarbons. Recent ATR FTIR spectroscopic studies indicated the necessity of correction in the phase-separation model of cuticular hydrocarbons proposed by A. G. Gibbs. [ABSTRACT FROM AUTHOR]

The present work deals with the synthesis and characterization of pure and transition metal (Ni, Cu and Fe) doped spinel Co3O4 nanoparticles (NPs), which are well known for their physical and chemical features. These transition metal doped Co3O4 NPs were tailored through thermal decomposition of precursors synthesized by simple co-precipitation, the simple and cost-effective strategy of fabricating mesoporous spinel cobalt oxide. This study investigates the photocatalytic degradation of industrial dyes Rhodamine B (RhB) and Methyl Orange (MO) under sunlight by using NPs as catalysts. Among the different nanocatalysts, Ni doped Co3O4 NP exhibited the highest efficiency in degrading the environmentally harmful dyes, proving the positive correlation between surface area and photodegradation efficiency. The structures and optical properties were investigated by Powder X-Ray Diffraction (PXRD), X-ray Photoelectron Spectroscopy (XPS), High-Resolution Transmission Electron Microscopy (HR-TEM), Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS) and Photoluminescence (PL) under dopant control. The morphology and polycrystallinity of the samples were studied using SEM-EDS and SAED patterns, respectively. The doped ferromagnetic samples showed unsaturation in hysteresis loops which specified the oxygen vacancy. [ABSTRACT FROM AUTHOR]

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Phosphatidylinositol-3-phosphate (PtdIns3P) is essential for generating autophagosomes and regulating endocytic trafficking. Recently, we have shown that the activities of human PIK3C3/VPS34-containing complexes I and II, which synthesize PtdIns3P, are greatly affected by three membrane physicochemical parameters: lipid unsaturation, membrane curvature, and negative charge. Both complexes are more active on membranes composed of unsaturated lipids than saturated lipids, and high membrane curvature can compensate for the negative effect of high lipid saturation. Negatively charged phosphatidylserine (PS) activates the complexes, as well as PIK3C3/VPS34 alone. The kinase activity of complex I depends critically on the ATG14 BATS domain, whereas complex II relies on the BECN1 BARA domain. Our findings highlight the importance of the membrane character as sensed by the unique membrane binding motifs/domain of the complexes for regulating PIK3C3/VPS34 activity. [ABSTRACT FROM AUTHOR]

This study investigates the effect of degumming process and catalyst type on physiochemical and biodiesel properties of tropical-almond (Terminalia catappa) seed oil (TCSO) extracted via mechanical pressing and solvent extraction method. The oil was degummed using 4% citric acid in amount of 10% by volume of the oil to reduce the acid value, ash content, and water and sediment value of the degummed oil compared to the raw oil. Data obtained show that degumming process reduces the acid value, ash content and water and sediment value from 7.57 mg KOH/g, 0.86 %w/w and 2.48% to 3.82 mg KOH/g, 0.65 %w/w and 2.40% respectively, and the percentage oil yield was 56.30±1.50%. Biodiesel was produced using a two-step reaction system from raw and degummed TCSO catalyzed by NaOH, KOH and CaO/Al2O3. The process yielded a higher yield (97.20±0.35) of biodiesel from degummed oil catalyzed by CaO/Al2O3. The fuel properties of the biodiesels were found to fulfill both ASTM D6751 and EN14214 biodiesel standard except the raw biodiesel. this study confirm that degumming process improves the susceptibility of oil for biodiesel production and that heterogeneous base catalyst produce higher yield and quality fuel than their homogenous counterpart. Keywords: Degummed, Transeterification, Biodiesel, Catalyst, Raw oil, unsaturation