Effect Of Stearic Acid Research Articles

The Thiol Group Reactivity and the Antioxidant Property of Human Serum Albumin Are Controlled by the Joint Action of Fatty Acids and Glucose Binding.

The binding of ubiquitous serum ligands (free fatty acids) to human serum albumin (HSA) or its glycation can affect thiol group reactivity, thus influencing its antioxidant activity. The effects of stearic acid (SA) and glucose binding on HSA structural changes and thiol group content and reactivity were monitored by fluoroscopy and the Ellman method during a 14-day incubation in molar ratios to HSA that mimic pathophysiological conditions. Upon incubation with 5 mM glucose, HSA glycation was the same as HSA without it, in three different HSA:SA molar ratios (HSA:SA-1:1-2-4). The protective effect of SA on the antioxidant property of HSA under different glucose regimes (5-10-20 mM) was significantly affected by molar ratios of HSA:SA. Thiol reactivity was fully restored with 5-20 mM glucose at a 1:1 HSA:SA ratio, while the highest thiol content recovery was in pathological glucose regimes at a 1:1 HSA:SA ratio. The SA affinity for HSA increased significantly (1.5- and 1.3-fold, p < 0.01) with 5 and 10 mM glucose compared to the control. These results deepen the knowledge about the possible regulation of the antioxidant role of HSA in diabetes and other pathophysiological conditions and enable the design of future HSA-drug studies which, in turn, is important for clinicians when designing information-based treatments.

Effects of stearic acid on the cryotolerance of the domestic cat (Felis silvestris catus) embryos

The current work aimed to study the effect of domestic cat (Felissilvestris catus) embryosin vitroexposure to saturated stearic acid (SA) and to evaluate how the change in lipid content affects the cryopreservation results. The addition of SA to the culture medium did not affect the development of cat embryosin vitrobefore cryopreservation. The total lipid amount in the SA-treated embryos was not changed as well. However, the lipid unsaturation degree was lower in embryos afterin vitroexposure to SA. Moreover, the lipid phase transition onset temperature (T*) was higher in SA-treated embryos as compared with controls. These changes of intracellular lipids unsaturation degree andT*were associated with the impairment of embryo cryopreservation effectiveness. The results obtained may be of importance for the applying Genome Resource Banking concept to the Felinae species.

Effect of Stearic Acid on the Efficiency of Cryopreservation of Embryos of the Domestic Cat (Felis silvestris catus)

Effect of Stearic Acid on the Efficiency of Cryopreservation of Embryos of the Domestic Cat (Felis silvestris catus)

Effects of stearic acid on the embryo cryopreservation in mouse

BACKGROUND: Intracellular lipids are sensitive to freezing. Lipidome modification is an important tool for studying the role of intracellular lipids in cryotolerance of mammalian oocytes and preimplantation embryos. OBJECTIVE: To study the effects of in vitro exposure of murine embryos to saturated stearic acid (SA) on the lipid content, embryo development and cryotolerance. MATERIALS AND METHODS: In vivo derived mouse embryos were cultured with 100 μM SA for 48 h up to the morula/blastocyst stage. Some of the SA-treated embryos were chosen for the evaluation of their development competence and the change in the lipidome, and other embryos were either slowly frozen or rapidly vitrified. RESULTS: Nile red staining combined with confocal laser scanning microscopy revealed a decrease in the total amount of lipids in the SA-treated embryos. Raman measurements showed that the lipid unsaturation was lower in embryos after in vitro SA culture. The addition of SA did not affect the embryo development before cryopreservation, but negatively affected the results of slow freezing cryopreservation and vitrification. CONCLUSION: In vitro SA exposure lowered the total amount of intracellular lipids and unsaturation in mouse embryos. The changes were accompanied with a significantly lower efficacy of embryo cryopreservation.

Effects of stearic acid on the tensile properties of ultrahigh molecular weight polyethylene fibers

AbstractFor the purpose of the development of ultrahigh molecular weight polyethylene (UHMWPE) fibers with improved tensile properties, the stearic acid (SA) was added to the gel spinning of UHMWPE and acted as a lubricant film. SA addition was intended to be 0.2, 0.4, 0.6, 0.8, and 1.0 wt% of UHMWPE for forming the SA modified UHMWPE fibers. The tensile properties, thermal properties, crystallization properties, and orientation properties of the prepared UHMWPE fibers were systematically investigated. Results show that there is a more significant tensile property for UHMWPE fibers as SA addition is 0.6 wt%. Their tensile strength and tensile modulus reach 32.86 and 1580.89 cN/dtex, which are raised to an extent of 12.0% and 7.7%, respectively, compared with UHMWPE fibers alone. Moreover, the thermal properties, crystallization properties, and orientation properties of the prepared UHMWPE fibers are enhanced observably when the SA addition is 0.6 wt%.

Effect of stearic acid on corrosion inhibition in magnesium-based materials

Effect of stearic acid on corrosion inhibition in magnesium-based materials

Effect of stearic acid on the mechanical and rheological properties of PLA/HA biocomposites

In this study, biocomposite filaments of polylactic acid (PLA) combined with stearic acid (SA)-coated nano-hydroxyapatite (HA) filler were prepared and characterized. These filaments were then used in material extrusion (MEX) additive manufacturing via fused deposition modeling (FDM) to create scaffolds for bone tissue engineering (BTE). Initially, HA was characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), and the Rietveld method. Particle size distribution was examined through dynamic light scattering (DLS), and its specific surface area was determined by the Brunauer-Emmett-Teller (BET) method. Subsequently, the HA nanoparticles were coated with stearic acid (SA) to explore its potential as a surfactant for PLA/HA nanocomposites. For composite fabrication, pure HA and SA-coated HA were mixed with PLA in a torque rheometer to obtain PLA/HA and PLA/HA-SA biocomposites. Their flow behavior was evaluated using a slit die rheometer, demonstrating that the SA coating improved rheological properties. The composites were extruded to produce 1.75 mm diameter filaments, which were analyzed by mechanical tensile testing, showing that the SA coating reduced the fragility of the PLA/HA filaments. The filaments exhibited high repeatability in terms of quality, facilitating scaffold printing. The FDM-manufactured scaffolds were analyzed through compressive testing, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and AlamarBlue Cell Viability Analysis. The results demonstrated that these scaffolds possess the required mechanical, thermal, and cytotoxicity properties for applications in bone tissue engineering.

Improvement in Luminescence Intensity of β-NaYF4: 18%Yb3+, 2%Er3+@β-NaYF4 Nanoparticles as a Result of Synthesis in the Presence of Stearic Acid.

The synthesis of upconverting nanoparticles (NPs) is crucial for their spectroscopic properties and further applications. Reducing the size of materials to nano-dimensions usually decreases emission intensity. Therefore, scientists around the world are trying to improve the methods of obtaining NPs to approach levels of emission intensity similar to their bulk counterparts. In this article, the effects of stearic acid on the synthesis of core@shell β-NaYF4: 18%Yb3+, 2%Er3+@β-NaYF4 upconverting NPs were thoroughly investigated and presented. Using a mixture of stearic acid (SA) with oleic acid and 1-octadecene as components of the reaction medium leads to the obtaining of monodispersed NPs with enhanced emission intensity when irradiated with 975 nm laser wavelength, as compared with NPs prepared analogously but without SA. This article also reports how the addition of SA influences the structural properties of core@shell NPs and reaction time. The presence of SA in the reaction medium accelerates the growth of NPs in comparison with the analogic reaction but without SA. In addition, transmission electron microscopy studies reveal an additional effect of the presence of SA on the surface of NPs, which is to cause their self-organization due to steric effects.

Effect of stearic acid on the microstructural, rheological and 3D printing characteristics of rice starch

The aim of this study was to investigate the changes of the microstructural, rheological and printing properties of rice starch-stearic acid (SA) paste during the hot-extrusion 3D printing (HE-3DP). The results showed that starch chains could complex with SA to form V-type crystalline structure and its molecular kinematic behaviors were changed under shear force, and crystalline structure were then embedded and rearranged to constitute an ordered sea-island structure, thus improving the rigidity and dynamic storage modulus of network structure, leading to the increased layer number. Interestingly, with the increase of SA addition, the network structure became weakened and the viscosity decreased which might due to the destroyed continuity and the breaking of entanglement and hydrogen bonding between starch chains, and finally impairing the printing accuracy of objects. Overall, this study provided important information for the application of lipid in the preparation of starch-based food by HE-3DP.

A Synergistic Effect between Stearic Acid and (+)-α-Tocopherol as a Green Inhibitor on Ferritic Stainless Steel Corrosion Inhibition in 3.0% NaCl Solution

The synergistic inhibitory effect of stearic acid and (+)-α-tocopherol (E307) as a green inhibitor within a highly hydrophobic layer on the corrosion of low-carbon ferritic stainless steels was investigated in 3.0 wt% NaCl solution at 25 °C, focusing on long-term immersion tests. For a broader characterisation of the surface properties, especially the modified surfaces, of the samples used, the following methods were chosen: SEM was used to investigate the surface morphologies, the water contact angle to examine the wettability, while the corrosion resistance was investigated by potentiodynamic measurements and electrochemical impedance spectroscopy. The inhibition efficiency for modified ferritic stainless steel surfaces reached more than 99% after 1 h of immersion and remained the same after 5 days immersion testing when the surfaces were modified with (SA + 2.0 wt% E307) and more than 97% with (SA + 0.5 wt% E307) under the same test conditions.

The effect of stearic acid and different loading treated and untreated EFB fiber on the tensile, structural and chemical properties of polypropylene/recycled acrylonitrile butadiene rubber/empty fruit bunch composites

A new developed of polymer materials made up of polypropylene (PP), recycled nitrile gloves (NBRr) and empty fruit bunch (EFB) fiber was fabricated. Recycled nitrile glove was blended together with PP plastic to reduce the use of petroleum based and to solve the issue of waste discarded at the landfill. EFB fiber was incorporated to lower the production cost of composite. Due to incompatibility of different phases, stearic acid treatment was used to improve the EFB fiber polarity. Thus, the effect of different EFB loading for untreated and treated stearic acid of PP/NBRr/EFB composite was studied. In this work, all the materials were mixed well using a heated two roll mill with temperature 180 °C within 9 minutes. The EFB loading were varied from 0 to 30 phr. The analysis of tensile properties was tested followed the ASTM D638, Type IV, testing procedure, to analyze tensile strength, Young’s modulus and elongation at break. The structural properties of the fracture sample surfaces were observed using Scanning Electron Microscope (SEM) and the chemical properties was analyzed using Fourier Transform Infra-Red (FTIR). Composites with stearic acid treatment have shown higher tensile strength compared to untreated EFB fiber. Besides, the micrograph structure surface from scanning electron microscopy analysis showed better fiber and matrix interaction, as the treated-EFB fiber is well encapsulated with the PP matrix. From the FTIR analysis, the intensity peak of OH for PP/NBRr/EFB/SA was reduced due to the removal O-H bond of cellulose from fibers during the surface modification of fibers.

Date Seeds Fiber Reinforced Low-Density Polyethylene: Effect of Stearic Acid on its Mechanical and Morphological Characteristics

The effect of different content of steric acid (3, 6 and 9 wt.%) on the mechanical properies (tensile, flexural and impact properties) and morphology of linear low-density polyethylene / date seeds (LLDPE/DS) composites were evaulated in this research. The composites were produced by using extrusion followed by injuction molding process. Results presented that the addition of steric acid at 3 wt.% to the composite has shown highest tensile strength and elongation at break as compared to other treated samples. This is due to the improvement on the fiber surface in presence of SA. However, the tensile strength and elongation at break decreased thereafter treatment with 6% and 9% of SA. Furthermore, the flexural and impact properties have shown the same trend of the tensile properties, this was consistent with the results shown on SEM micrographs.

The Effects of Stearic Acid (SA) on the Thermal and Physical Properties of LLDPE/DS Composites

In this study, polymer composites were synthesized from date seeds (DS) powder as natural filler and low-density polyethylene (LLDPE) as polymer matrix. This composite was exposed into chemical modification using different content of Stearic Acid (SA) (3, 6 and 9 wt.%). The composite was fabricated by using the process of extrusion and injection molding respectively. The prepared samples were examined using TGA, DSC, FTIR, and Gel Content test. It can be clearly observed that all the treated samples have presented three-steps of decomposition as shown in TGA curves. It is also observed that the Tm, Tc, and degree of crystallinity of the modified LLDPE/DS biocomposites increased as SA increase. Thr FTIR spectra have shown different type of stretching bands, the band at 3346 - 3347 cm-1 appeared because of hydroxyle (OH) groups that is described as a hydrophilicity measure. Beside, there was a minor decrease on the peak between 3346 and 3347 cm-1 of modified composite, whichwas attributed to the hemicellulose removal from the modified composite. The gel content of the treated mples increased due to the increase of crosslinking between DS and LLDPE in existence of SA.

Diet containing stearic acid increases food reward-related behaviors in mice compared with oleic acid

Obesity is currently a worldwide phenomenon. The consumption of calorie-rich foods is responsible for most obesity cases, but not all humans exposed to high-calorie diets develop obesity. According to recent studies, exposure to fat-rich diets may be the actual cause of obesity. Dietary long-chain fatty acids affect brain function and are linked to food intake and motivation-related behaviors. Recently, many studies have shown that different types of fatty acids play different roles in animals. In our study, the effects of stearic acid (a saturated fatty acid) and oleic acid (a monounsaturated fatty acid) in diets on hedonic feeding behaviors were investigated, and changes of feeding-related protein levels in the brain were detected to explore the possible mechanism underlying the effects of these fatty acids. As a result, mice fed a diet containing stearic acid, compared to a diet containing oleic acid, exhibited increased food intake, hedonic eating, and an operant response to sucrose and locomotor activity. Furthermore, stearic acid corresponded to a higher level of leptin in serum than oleic acid. In addition, the stearic acid treated group had lower protein levels of p-JAK2 and p-STAT3 in the VTA and a higher dopamine concentration in the NAc than the oleic acid-treated group. Meanwhile, the protein level of TH in the NAc was higher and the protein level of the DA transporter in the VTA was lower in the stearic acid-fed group than in the oleic acid-fed group. In conclusion, these findings indicated that a diet containing stearic acid can increase hedonic feeding behavior and affect mesolimbic dopamine system signals in mice. Moreover, the lowering of serum leptin and leptin signaling in the VTA may contribute to this effect.

Effect of stearic acid on rheological properties and printability of ethylene vinyl acetate based feedstocks for fused filament fabrication of alumina

Alumina ceramic feedstocks with ethylene vinyl acetate and stearic acid as an organic binder were prepared and shaped by a commercial 3D filament printer. Rheological properties and the ability of ceramic feedstocks to be processed into filaments and shaped by the fused deposition modeling/filament (FDM/FFF) technique were investigated.The addition of stearic acid affects the viscosity as a function of shear rate in a complex way. Analysis with rheological models shows that while using a small amount of stearic acid, a viscosity plateau at low shear rate (cross model) can be observed. At high stearic acid content, a yield point (Herschel-Bulkley model) occurs, as the stearic acid content surpasses the amount needed to cover the powder surface. The stearic acid also influences the properties of the solidified filament, making it more brittle and less flexible.Thin wall structures were printed, debinded and sintered to demonstrate the shape stability and fusion between the layers. Ring-on-ring bending tests of sintered discs show that the printing defects are the primary concerns that determine the strength of sintered samples.

Effects of Stearic Acid on Proliferation, Differentiation, Apoptosis, and Autophagy in Porcine Intestinal Epithelial Cells.

Stearic acid (SA), a saturated long-chain fatty acid consisting of 18 carbon atoms, is widely found in feed ingredients, such as corn, soybeans, and wheat. However, the roles of SA in the renewal of intestinal epithelial cells remain unclear. In the present study, we found that 0.01-0.1 mM SA promoted IPEC-J2 cell differentiation and did not affect IPEC-J2 cell viability. In addition, the results showed that the viability of IPEC-J2 cells was inhibited by SA in a time- and dose-dependent manner at high concentrations. Flow cytometry and western blot analysis suggested that SA induced apoptosis, autophagy and ER stress in cells. In addition, the amounts of triglyceride were significantly increased upon challenge with SA. Moreover, the decrease in the viability of cells induced by SA could be attenuated by 4-PBA, an inhibitor of ER stress. In summary, SA accelerated IPEC-J2 cell differentiation at 0.01-0.1 mM. Furthermore, SA induced IPEC-J2 cell apoptosis and autophagy by causing ER stress.

Оценка воздействия стеариновой кислоты (С18:0) на количественный состав микробиома рубцовой жидкости молодняка крупного рогатого скота

Оценка воздействия стеариновой кислоты (С18:0) на количественный состав микробиома рубцовой жидкости молодняка крупного рогатого скота

Effect of stearic acid as a low cost and green material on the self-cleaning and anti-corrosion behavior of anodized titanium

A simple and highly effective route for preparation of superhydrophobic titanium (Ti) surface by single-step anodization in an organic electrolyte and subsequent stearic acid modification is suggested in this paper. Ti was anodized to produce micro-nano hierarchical morphology, which is extremely important for superhydrophobic surface. The anodized Ti was then treated with stearic acid to reduce surface energy. Surface morphology and structure of the anodized surfaces was characterized by field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). X-ray diffraction (XRD), X-ray energy dispersive spectrometry (EDS), and Fourier transform infrared (FT-IR) spectroscopy were utilized to specify chemical composition of superhydrophobic surfaces. The morphology of the surfaces was modified by adjusting anodizing parameters such as time (1, 2, 3, 4 and 5 h) and voltage (5, 20, 35 and 50 V). The results showed that static water contact angle and contact angle hysteresis on the best superhydrophobic Ti surface (with anodizing parameters of 3 h and 35 V) are 160.1° ± 0.5˚ and 7°, respectively. Furthermore, the superhydrophobic surface obtained has an acceptable self-cleaning and anticorrosion properties.

Understanding the Role of Fatty Acid Substrates on Primycin Biosynthesis by Saccharomonospora azurea During Batch Fermentation

Primycin is a 36-membered marginolactone antibiotic that is biosynthesized through the modular type I polyketide synthase pathway produced by Saccharomonospora azurea, a Gram-positive, soil-dwelling filamentous bacteria. In industrial-scale batch fermentation the primycin-producing strain is cultivated in a complex fermentation media empirically optimized for antibiotic production. To determine the role of various fatty acids on primycin production, the effect of stearic acid (C18:0), palmitic acid (C16:0), lauric acid (C12:0), capric acid (C10:0), enanthic acid (C7:0), caproic acid (C6:0), and butyric acid (C4:0) in growth medium was studied. Our results clearly show that palmitic acid was a better alternative of the originally applied stearic acid in all tested concentrations, while 4.5 g/L proved to be the most effective.

Effect of Stearic Acid as a Co‐solvent on the Solubility Enhancement of Aspirin in Supercritical CO2

AbstractThe solubility of aspirin in supercritical CO2 (SC‐CO2) with stearic acid as a co‐solvent was measured at various pressures and temperatures. The experimental data were obtained by a static method. Stearic acid had a significant effect on the enhancement of solubility, as the aspirin solubility increased by up to 16 times. Further, the effect of stearic acid on the solubility enhancement of aspirin was compared with that of other co‐solvents. Different semi‐empirical models from the literature were applied for correlating the experimental data, proving good agreement with the experimental data. The model of Sung and Shim exhibited the lowest deviation from the obtained data. The results of the solubility test can be employed to produce aspirin‐based pharmaceuticals using supercritical fluid technology (SFT).