Anti-aging Ability Research Articles

Study on HPLC fingerprint of Saposhnikovia divaricata lipophilic components and anti-aging effects

Saposhnikovia divaricata is commonly used in clinical practice as a heat-clearing and detoxifying traditional Chinese medicine. Current research on Saposhnikovia divaricata has mostly focused on chromones, while studies on its lipophilic parts remain scarce. In this study, samples of the lipophilic components of Saposhnikovia divaricata (SDL) from different regions in China were collected to establish an HPLC fingerprint. The quality of SDL was evaluated through chemical pattern recognition and multi-component content determination. Furthermore, using the Caenorhabditis elegans (C. elegans) model, the anti-aging ability of SDL was preliminarily studied. In the HPLC fingerprints of 11 batches of SDL, 19 common peaks were identified, and 4 components were characterized as follows: peak 14, linolenic acid (ALA); peak 15, docosahexaenoic acid (DHA); peak 16, linoleic acid (LA); peak 17, oleic acid (OA). The similarity of the fingerprint ranged from 0.704 to 0.929. The results indicate that the content of ALA, DHA, LA, and OA are 0.040–0.440 mg/g, 0.003–0.116 mg/g, 1.047–6.460 mg/g, and 0.040–0.294 mg/g, respectively. HCA analysis divided 11 batches of SDL into two categories, and PCA analysis extracted 6 principal components with a cumulative contribution rate of 85.91%. The anti-aging ability of the SDL was proved by measuring the lifespan, reproductive capacity, body length, mobility, lipofuscin content, and heat stress resistance of C. elegans. The combination of high-performance liquid chromatography fingerprint and chemical pattern recognition for multi-component content determination is a reliable, comprehensive, and promising evaluation of the quality of SDL. The confirmation of SDL’s anti-aging ability provides the possibility for the research of Saposhnikovia divaricata in the field of healthy food and cosmetics.

Simulation and investigation of the mild-moderate aging properties of SBS modified bitumen: Physical, microscopic and rheological properties

Styrene-butadiene-styrene block copolymer (SBS) modified bitumen (SMB) is unable to meet usage requirements after being exposed to sun-light, heat and oxygen. The researches show that it is difficult to restore bitumen effectively when the penetration of the aged bitumen is below 20 dmm. Therefore, the penetration of 20 dmm is taken as the dividing line in this paper. Higher than 20 dmm is considered as mild-moderate aging, while lower than 20 dmm is considered as severe aging. The traditional rotating thin-film ovens (RTFO) and pressure aging vessels (PAV) methods are similar to simulate the aging behavior of the upper layer of bitumen pavement, but they are difficult to simulate the aging in the depth direction of bitumen pavement. In this paper, the aging of the modified bitumen is simulated by extending the aging time and deepening the depth of the aging mold, and then it is graded according to the penetration. We aimed to investigate the differences in physical, microscopic and rheological properties of SMB with including 0 wt%, 1.5 wt%, 2.5 wt%, 3.5 wt%, 4.5 wt% and 5.5 wt% SBS content before and after aging. Through the physical performance, such as penetration, softening point, ductility and elastic recovery, it was observed that a high SBS content leads to strong anti-aging ability. Fourier Transform Infrared (FTIR), fluorescence microscopy (FM), scanning electron microscopy (SEM) and atomic-force microscope (AFM) revealed that a good network structure can be formed through absorbing light components when the SBS exceeds 3.5 wt%. After that, it was found that there is a positive correlation between aromatic index and penetration, as well as a positive correlation between butadiene index and softening point. Additionally, rheological frequency scanning and temperature scanning indicated that the modulus was increased and the phase angle was decreased with increasing SBS content or aging. After aging, the rutting resistance of SMB was enhanced but the cracking resistance was weakened. This research can establish a theoretical support and foundation for the regeneration of the mild-moderate aged SMB.

GDF11 protects against mitochondrial-dysfunction-dependent NLRP3 inflammasome activation to attenuate osteoarthritis

IntroductionOsteoarthritis (OA) is a highly prevalent degenerative disease worldwide, and tumor necrosis factor (TNF-α) is closely associated with its development. Growth differentiation factor 11 (GDF11) has demonstrated anti-injury and anti-aging abilities in certain tissues; however, its regulatory role in OA remains unclear and requires further investigation. ObjectivesTo identify whether GDF11 can attenuate osteoarthritis. To exploring the the potential mechanism of GDF11 in alleviating osteoarthritis. MethodsIn this study, we cultured and stimulated mouse primary chondrocytes with or without TNF-α, analyzing the resulting damage phenotype through microarray analysis. Additionally, we employed GDF11 conditional knockout mice OA model to examine the relationship between GDF11 and OA. To investigate the target of GDF11′s function, we utilized NLRP3 knockout mice and its inhibitor to verify the potential involvement of the NLRP3 inflammasome. ResultsOur in vitro experiments demonstrated that endogenous overexpression of GDF11 significantly inhibited TNF-α-induced cartilage matrix degradation and inflammatory expression in chondrocytes. Furthermore, loss of GDF11 led to NLRP3 inflammasome activation, inflammation, and metabolic dysfunction. In an in vivo surgically induced mouse model, intraarticular administration of recombinant human GDF11 alleviated OA pathogenesis, whereas GDF11 conditional knockout reversed this effect. Additionally, findings from the NLRP3-knockout DMM mouse model revealed that GDF11 exerted its protective effect by inhibiting NLRP3. ConclusionThese findings demonstrate the ability of GDF11 to suppress TNF-α-induced inflammation and cartilage degeneration by preventing mitochondrial dysfunction and inhibiting NLRP3 inflammasome activation, suggesting its potential as a promising therapeutic drug for osteoarthritis.

The Impacts of Red Mud on Road Performance and Aging Resistance of Asphalt Mixture

Abstract Red mud as an asphalt modifier has been investigated in some studies, but few studies are further concerned about the effect of red mud on performance of asphalt mixture. In this study, the impact of red mud on road performance and aging endurance of asphalt mixtures was evaluated. Primarily, the optimal asphalt content was determined based on mechanical strength and volumetric properties. Then, the performance evaluations, including Marshall stability, low-temperature splitting, freeze-thaw splitting, indirect tensile fatigue, and thermal-oxidative aging, were executed. The outcomes demonstrate that in comparison with the base asphalt mixture, red mud asphalt mixture exhibits worse high-temperature stability and moisture resistance, and superior temperature shrinkage cracking resistance and fatigue performance. After the surface of red mud has been modified, the adhesion between asphalt mastics and aggregate is strengthened, and the distribution of red mud in asphalt mixture becomes more uniform, which intensifies the rigidity and road performance (except for low-temperature cracking resistance) of asphalt mixture. Furthermore, since red mud absorbs a portion of asphalt content, it can hinder the physical hardening and oxidation rate of asphalt mixture. The anti-aging ability of asphalt mixture is further reinforced by the incorporation of organic red mud.

Creation of fully degradable and mechanically robust poly(4-hydroxybutyrate) films by filling modified starch

Chemically synthesized poly(4-hydroxybutyrate) (P4HB) is a new generation of biomass-derived and degradable semi-crystalline polymer with good comprehensive properties, but high costs limit its application. Starch, as an inexpensive natural polymer, can reduce the cost of P4HB products. However, starch lacks thermoplastic behavior and has poor compatibility with P4HB, thus its extensive use will inevitably impair the mechanical properties of P4HB. In this study, the ball-milling starch grafting process is adopted, which can simultaneously solve the two major deficiencies of starch, and the prepared ball-milling starch-g-polycaprolactone (BSt-g-PCL) has thermoplasticity and better compatibility with P4HB. BSt-g-PCL can melt near 55 °C, and the interweaving of its molecular chains with P4HB reduces the binding energy (Einteraction) of both, making the phase interface blurred or even disappear. Therefore, the elongation at break retention (REB) of P4HB/BSt-g-PCL can increase from 37.1 % to 74.3 % compared to P4HB/starch at the same filling (70 Phr). Additionally, BSt-g-PCL can exert the effect of accelerating P4HB degradation and still make it maintain excellent anti-aging ability. The ball-milling starch graft process provides a simple and effective method for the preparation of inexpensive fully biodegradable P4HB composite films with excellent mechanical properties.

The Combined Anti-Aging Effect of Hydrolyzed Collagen Oligopeptides and Exosomes Derived from Human Umbilical Cord Mesenchymal Stem Cells on Human Skin Fibroblasts.

Stem cell-derived exosomes (SC-Exos) are used as a source of regenerative medicine, but certain limitations hinder their uses. The effect of hydrolyzed collagen oligopeptides (HCOPs), a functional ingredient of SC-Exos is not widely known to the general public. We herein evaluated the combined anti-aging effects of HCOPs and exosomes derived from human umbilical cord mesenchymal stem cells (HucMSC-Exos) using a senescence model established on human skin fibroblasts (HSFs). This study discovered that cells treated with HucMSC-Exos + HCOPs enhanced their proliferative and migratory capabilities; reduced both reactive oxygen species production and senescence-associated β-galactosidase activity; augmented type I and type III collagen expression; attenuated the expression of matrix-degrading metalloproteinases (MMP-1, MMP-3, and MMP-9), interleukin 1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α); and decreased the expression of p16, p21, and p53 as compared with the cells treated with HucMSC-Exos or HCOPs alone. These results suggest a possible strategy for enhancing the skin anti-aging ability of HucMSC-Exos with HCOPs.

Construction of unique oxygen vacancy defect through various metal-doping (Cu, Mn, Zr) of Ce2Co1Ox nanoparticles towards boosting the catalytic oxidation toluene performance

Achievement of catalytic oxidation of volatile organic compounds (VOCs) at low temperature is still a challenge to be addressed. Promoting catalytic activity via constructing oxygen vacancy defect is an attractive strategy in heterogeneous catalysis. Herein, a series of Ce2Co1M1 (M = Cu, Mn, Zr) catalysts were prepared by modified co-precipitation method and their catalytic oxidation performance of toluene was measured. Activity results suggested that the introduction of doping-metals significantly enhanced the catalytic performance of Ce2Co1Ox, with Ce2Co1Cu1 possessed the optimal catalytic activity (T90 = 210 ℃), robust stability, water resistance, GHSV tolerance and anti-aging ability. It has been demonstrated that Cu-doping resulted in the formation of Cu-Ce solid solution and constructed a Cu2+-O-Ce4+ complex active site. Benefiting from this, the redox and gaseous oxygen molecule capture & activation capabilities of the catalyst are tremendously improved via constructing abundant oxygen vacancies. The in-situ DRIFTS results revealed that Ce2Co1Cu1 exhibited a better C=C breaking of aromatic rings ability, a faster consumption rate of benzoate and maleic anhydride, and is less prone to accumulation of by-products, the above account for its enhanced low-temperature catalytic performance for toluene. This work may provide a new strategy to design the high-efficiency toluene oxidation catalysts.

COP-22 Alleviates d-Galactose–Induced Brain Aging by Attenuating Oxidative Stress, Inflammation, and Apoptosis in Mice

Aging is a natural and inevitable process of organisms. With the intensification of population aging, research on aging has become a hot topic of global attention. The most obvious manifestation of human aging is the aging of brain function, which has been linked to the development of neurodegenerative diseases. In this study, COP-22, a mono-carbonyl curcumin derivative, was evaluated for its anti-aging ability, especially its ability to resist brain aging induced by D-galactose (D-gal) in mice. For brain protection, COP-22 could resist D-gal–induced oxidative stress by increasing the activity of antioxidative defense enzymes and enhancing antioxidant capacity in the brain tissue; COP-22 could improve the dysfunction of the cholinergic system by decreasing the increased activity of acetylcholinesterase and increasing the reduced content of acetylcholine induced by D-gal; and COP-22 could protect nerve cells of the brain. Further, western blot was used to determine related proteins of the brain. We found that COP-22 could effectively protect against brain injury (SIRT1, p53, p21, and p16) by inhibiting oxidative stress (Nrf2 and HO-1), inflammation (IL-6 and TNF-α), and apoptosis (Bax and caspase-3) in D-gal–induced aging mice. Additionally, COP-22 demonstrated the ability to reduce oxidative stress in serum and liver caused by D-gal, as well as relieve the damages in the liver and kidney induced by D-gal. These results indicated that COP-22 had potential anti-aging activity and could be used in the therapy of aging and aging-associated diseases like Alzheimer disease.

Performance investigation of phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT) compound-modified bituminous mixture

ABSTRACT Composite modification has proven to be an effective strategy in addressing the insufficient performance associated with single-modified bituminous mixture. This research aims to thoroughly investigate the performance of the compound-modified bituminous mixture incorporation phenol–formaldehyde resin (PF) and organic montmorillonite (OMMT). The performance investigations of the bituminous mixture were conducted through the Marshall stability test, dynamic stability test, indirect tensile test, immersion Marshall test, freeze–thaw splitting test, indirect tensile fatigue test and long-term aging test. The test results indicated that OMMT plays a crucial role in advancing thermal storage stability and compatibility between PF and bitumen. Importantly, the optimal dosage of OMMT was determined not to exceed 5%. The 3%PF+5%OMMT bituminous mixture demonstrated excellent rutting and cracking resistance, superior water stability and anti-fatigue capabilities. Furthermore, the 2%PF+5%OMMT and 3%PF+5%OMMT bituminous mixtures exhibited superior anti-aging abilities. In consideration of laboratory performance and bitumen compatibility, the combination of 3%PF+5%OMMT can be utilised to enhance the bituminous mixture performance. The results of single-factor analysis of variance indicated that PF and OMMT had significantly impact on the bituminous mixture performance. Notably, the influence of PF/OMMT dosage on the cracking resistance, water stability and anti-aging ability requiring attention when considering them as bitumen modifiers.

The protective effect of PL 1-3 on D-galactose-induced aging mice.

The aging population has become an issue that cannot be ignored, and research on aging is receiving increasing attention. PL 1-3 possesses diverse pharmacological properties including anti-oxidative stress, inhibits inflammatory responses and anti-apoptosis. This study showed that PL 1-3 could protect mice, especially the brain, against the aging caused by D-galactose (D-gal). D-gal could cause oxidative stress, inflammation, apoptosis and tissue pathological injury and so on in aging mice. The treatment of PL 1-3 could increase the anti-oxidative stress ability in the serum, liver, kidney and brain of aging mice, via increasing the total antioxidant capacity and the levels of anti-oxidative defense enzymes (superoxide dismutase, glutathione peroxidase, and catalase), and reducing the end product of lipid peroxidation (malondialdehyde). In the brain, in addition to the enhanced anti-oxidative stress via upregulating the level of the nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, PL 1-3 could improve the dysfunction of the cholinergic system via reducing the active of acetylcholinesterase so as to increase the level of acetylcholine, increase the anti-inflammatory and anti-apoptosis activities via downregulating the expressions of pro-inflammatory cytokines (interleukin-6 and tumor necrosis factor-α) and pro-apoptosis proteins (Bcl-2 associated X protein and Caspase-3) in the D-gal-induced aging mice, to enhance the anti-aging ability via upregulating the expression of sirtuin 1 and downregulating the expressions of p53, p21, and p16. Besides, PL 1-3 could reverse the liver, kidney and spleen damages induced by D-gal in aging mice. These results suggested that PL 1-3 may be developed as an anti-aging drug for the prevention and intervention of age-related diseases.

Anti-phototoxicity and anti-melanogenesis activities of eelgrass Zostera marina and its phenolic constituents

The eelgrass Zostera marina L. has several economic roles, from its earlier usage in the insulation industry to protecting the earth from global warming. In this study, we aimed to discover the cosmetic potential of Z. marina. A methanolic extract of Z. marina showed anti-phototoxicity and anti-melanogenesis activity with an IC50 of 17.5 μM, followed by a phytochemical analysis of its phenolic constituents. Ten compounds (1−10) were isolated by several chromatographic techniques and identified by means of nuclear magnetic resonance spectroscopy (NMR) as well as high-resolution mass spectrometry (HR/MS). The identified compounds are caffeic acid (1), 3,4-dihydroxybenzoic acid (protocatechuic acid) (2), luteolin (3), diosmetin (4), 4-coumaroyl-4′-hydroxyl phenyllactic acid (5), rosmarinic acid (6), caffeoyl-4′-hydroxy-phenyllactic acid (isorinic acid) (7), apigenin 7-O-β-D-glucopyranoside (8), luteolin 7-O-β-D-glucopyranoside (9), and luteolin 7-sulfate (10). This is the first report to identify compounds 5 and 7 from the family Zosteraceae. The isolated compounds were assessed for their anti-aging abilities and were found to exhibit good anti-phototoxicity and anti-melanogenesis activities by increasing the viability of UVB-irradiated HaCaT cells by 6% to 34% and by inhibiting melanin synthesis in B16 melanoma cells by 44% to 65%.

Anti-Aging Properties of Temulawak Extract (Curcuma xanthorrhiza L.) by In Vitro Assay

Highlights:1. Elastase, hyaluronidase, and tyrosinase can all be inhibited by temulawak extract.2. Temulawak extract has strong anti-aging ability and can be used as a candidate for cosmetic applications. AbstractThe process of aging is the gradual loss of a tissue's capacity to heal and maintain normal or physiological form and function. Elastase, hyaluronidase, and tyrosinase are the enzymes that contribute to skin aging. The anti-aging effect is connected to the inhibition of these enzymes' activity. Many medicinal plants with active metabolite have been utilized extensively to treat aging. Active compounds of temulawak (Curcuma xanthorrhiza L.) such as phenolic, curcuminoid and xanthorrhizol have potential as antiaging. This study aims to determine whether temulawak extract (TE), a potential candidate for cosmeceutical agent, has anti-aging characteristics by inhibiting the elastase, hyaluronidase, and tyrosinase enzymes. TE was processedxby PT FAST. Stock solution of TE was made by dissolving 20 mg of extract with 1 ml of DMSO 100%, the stock solution was then diluted to achieve the concentrations level 31.25 - 1000 μg/ml working solution of TE. The antiaging activity assays were carried out at PT Aretha Medika Utama. In vitro antiaging assay of TE includes elastase, hyaluronidase, and tyrosinase enzyme inhibition at 7 level of various concentrations of 2.08-66.67 μg/ml for anti-elastase assay, 5.21-166.67 μg/ml for anti-hyaluronidase assay, and 3.125-100 μg/ml for anti-tyrosinase assay with three replications. SPSS software was used to conduct the statistical analysis (p<0,05 is considered significant). TE exhibited highest inhibition percentage of 82.72%, 89.41%, and 94.17% for anti-tyrosinase, anti-elastase, and anti-hyaluronidase, respectively. The median inhibitory concentration (IC50) for elastase inhibitory activity was 10.66 μg/ml, hyaluronidase 70.39 μg/ml, and tyrosinase 55.87 μg/ml. According to this study, TE can be used as cosmeceu

Enhanced anti-aging behaviors in cubic phase CeO2 induced BaSnO3 thermosensitive ceramics

The anti-aging ability is an important index to measure the temperature measurement application of thermosensitive materials. Herein, the BaSnO3 + xCeO2 (x = 0 %, 2 %, 4 %, 7 %) ceramics were synthesized via mixing BaSnO3 with CeO2. By combining with CeO2, some Ce4+ replaces Sn4+ to improve the phase structure stability, which improves the high-temperature stability of the thermosensitive ceramic, reducing the aging coefficient from 50 % to 2.5 %. Meanwhile, the resistivity decreases with the increase of CeO2 composition, which can be attributed to the increase of Ce3+ content, resulting in the increase of the number of small polaron. With the increase of x content, thematerial constant B500/850, activation energy Ea and resistivity ρ500 of the ceramic decrease. The B values and Ea values of the thermistors are in the range of 12341–17155 K and 1.06–1.48 eV, respectively. These results indicate that BaSnO3 + xCeO2 composites are potential candidates in high temperature NTC thermistor devices.

In-depth understanding of the ‘‘promoting and binding’’ effects of Rh/CeO2-ZrO2 interaction regulation on TWCs performance

How metal-support interaction (MSI) affects three-way catalysts (TWCs) performance has always been a focus. This work regulated the interaction between Rh and CeO2-ZrO2 (CZ) by support pretreatment scheme, meanwhile deeply analyzed the effect on activity and stability. CZ after 1000 ℃ pretreatment weakened the MSI and made more active Rh on CZ surface, which significantly enhanced catalytic efficiency (C3H8 T90 decreased by 40 ℃). However, this weakened MSI prevented CZ from anchoring Rh, leading to the growth of Rh after aging and adversely affecting anti-aging ability (T90 increased by 90 °C). Fortunately, when CZ pretreatment at 900 °C, the catalytic performance did not decrease after aging due to the retained strong MSI. In addition, the change of oxygen vacancy concentration caused by CZ pretreatment was positively correlated with MSI strength. This work provided an in-depth understanding for MSI and a new idea for Rh-based TWCs design by elucidating the correlation between MSI and TWCs performance.

Synergistic effect of surface modified nano-zinc oxide and organic vermiculite on long-term ultraviolet and thermal-oxidative aging resistance of different asphalt binders

Asphalt pavement will be subjected to the action of thermal, oxygen and ultraviolet during long-term service, which in turn causes the ultraviolet and thermal-oxidative aging of asphalt simultaneously. Based on the long-term aging mechanism, the double retarding effect of surface modified nano-zinc oxide (ZnO) and organic vermiculite (OEVMT) in different stages of long-term aging was utilized in the research. This work investigated the synergistic effect of ZnO and OEVMT on rheological properties and chemical structures of base asphalts (70# and SK-70) and polymer modified asphalts (SBS modified asphalt and SBR modified asphalt) after long-term ultraviolet and thermal-oxidative aging. Dynamic shear rheological (DSR), bending beam rheological (BBR) and Fourier infrared spectroscopy tests were utilized to study the DSR properties, BBR properties at low temperature and chemical structures, respectively. Meanwhile, the synergistic effect mechanism was analyzed. Results showed that the effect of 1 % ZnO to resist the long-term ultraviolet aging of 70# base asphalt approximates that of 3 % OEVMT, while the long-term thermal-oxidative anti-aging ability of 1 % OEVMT for 70# base asphalt is equivalent to that of 3 % ZnO. Besides, compared with 2 % ZnO or 2 % OEVMT, 1 % ZnO + 1 % OEVMT shows a better long-term ultraviolet and thermal-oxidative aging resistance for different asphalt binders, indicating its synergistic effect in strengthening the anti-aging performance of asphalt. Moreover, 1 % ZnO + 1 % OEVMT not only can effectively retard the oxidation rate of asphalt in the process of long-term aging, but also inhibit the degradation degree of modifiers in SBS modified asphalt. The research could propose a new design idea to effectively solve the long-term aging problem of asphalt.

WS2-based inorganic triboelectric nanogenerators with light-enhanced output and excellent anti-aging ability

Conventional triboelectric nanogenerators (TENGs) usually use polymer as friction layers, because polymer usually has large electronegativity differences and reliable frictional recovery properties. In recent years, inorganic material-based TENG has drawn attention due to its much higher resistance to high-temperature aging, light aging, and fatigue resistance than polymer. However, the performance of TENG with aging has not been fully studied. In this work, pure inorganic TENG based on WS2 and ITO glass was prepared, achieving a short-current (ISC) of 0.3 μA and an open voltage (VOC) of 30 V in the dark. Particularly, the current output of the nanogenerator could be enhanced to 0.61 μA under illumination. In addition, accelerated aging experiments indicated that the inorganic nanogenerator had a good improvement in performance degradation compared to most conventional polymeric nanogenerators. Based on this work, WS2-based inorganic TENGs have stability advantages and may be fully used in a wider range of environments.

Acteoside palliates d-galactose induced cognitive impairment by regulating intestinal homeostasis.

Acteoside, an important phenylethanol glycoside, is the main active component in Osmanthus fragrans flower. Our previous study found that acteoside showed high antiaging effect but its absorption rate was low. We speculated acteoside palliated aging-related cognitive impairment before being absorbed, that was intestinal homeostasis underlie the antiaging effect of acteoside. In this study, acteoside was confirmed to palliate cognitive impairment in d-galactose induced aging mice. Acteoside treatment dramatically reduced oxidative stress, alleviated intestinal inflammation, restored intestinal mucosal barrier, rebuilt gut microbiome structure and upregulated gut microbiome metabolites short-chain fatty acids (SCFAs) and amino acids (AAs). Furthermore, antibiotic treatment revealed that the antiaging ability of acteoside was abolished in microbiota depleted mice, which offered direct evidence for the essential role of gut microbiota in the attenuation of cognitive impairment of acteoside. Together, our study indicated that acteoside palliated cognitive impairment by regulating intestinal homeostasisand acteoside intake might be a promising nutritional intervention in prevention of neurodegenerative diseases.

Study on Aging Mechanism and High-Temperature Rheological Properties of Low-Grade Hard Asphalt.

In order to investigate the potential application of low-grade hard asphalt in high-temperature and high-altitude areas, various tests were conducted to analyze the performance and high-temperature rheological properties of 30#, 50#, and 70# matrix asphalt under thermo-oxidative aging and ultraviolet aging. The tests utilized for analysis included the examination of basic asphalt properties, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), gel permeation chromatography (GPC), dynamic shear rheology (DSR), and multi-stress creep recovery (MSCR). The results indicate a progressive decrease in asphalt performance with increasing aging time. Prolonged exposure to thermal oxygen aging and ultraviolet irradiation significantly diminishes the plasticity of asphalt. The carbonyl index and sulfoxide index of asphalt increase after thermal oxygen aging and ultraviolet aging. Notably, 30# asphalt demonstrates greater resistance to aging compared to 50# and 70# asphalt under long-term high ultraviolet radiation. The LMS% of 30#, 50#, and 70# asphalt increases by 14%, 15%, and 16%, respectively. Following photothermal oxidative aging, a larger proportion of lighter components in the asphalt transforms into resins and asphaltenes. The high-temperature rheological properties of the three types of asphalt rank as 30# > 50# > 70#, while within the same type of asphalt, the high-temperature rheological properties rank as PAV > UV3 > UV2 > UV1 > RTFOT > virgin. Elevating temperature, stress level, and stress duration negatively impact the high-temperature stability of asphalt. In general, low-grade asphalt demonstrates superior anti-aging ability and high-temperature rheological properties during the aging process.

Research on Controllable Artificial Chalking Method for Silicone Rubber

Chalking of silicone rubber (SR) is a universal and important aging phenomenon. However, performing chalking simulation to study the aging performance of SR in the laboratory is difficult. In this study, a controllable artificial chalking method, which was based on selective scission reactions using methylcyclohexane (MCH) and diethylamine (DEA) as solvents, and tetramethylammonium hydroxide as the catalyst, was developed. Through controlling the ratio between DEA and MCH, different chalking degrees of SR could be realized artificially. The macroscopic observation, scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were conducted to compare the differences of samples with various chalking degrees. Furthermore, the control mechanism of the degree of chalking and the function of DEA during the artificial chalking process was elucidated. The results demonstrated that the artificial chalking method was feasible and could help identify the anti-aging ability of SR.

Fenugreek seed ethanolic extract inhibited formation of advanced glycation end products via scavenging reactive carbonyl intermediates

Senescence is a natural phenomenon of growing old. It accelerates under certain conditions like diabetes mellitus resulting in early decline of bodily functions, which can be avoided by many claimed functional foods. The present study aims to investigate the anti-aging ability of Fenugreek seeds (Trigonellafoenum-graecum); a common ingredient of Indo-Pak cuisines. Briefly, the Fenugreek seeds extract (FgSE) in concentrationsof0.1, 0.5 and 1 mg/ml inhibited the formation of Advanced Glycation End products (AGEs) and fructosamine adducts in Bovine serum albumin (BSA)/fructose model in vitro. The BSA conformational analysis via Circular Dichorism and Congo red assays showed that it preserves secondary structure of BSA in aforementioned model. Although mechanistic studies revealed insignificant lysine blocking ability of Fenugreek by OPA assay, however carbonyl entrapping was found to be 24%, 34% and 42% at 0.1, 0.5 and 1 mg/ml, respectively. In vivo model of High Fructose diet (HFD) induced glycation, FgSE treatment in doses of 10, 25 & 50 mg/kg markedly improved Escape latency (p < 0.01) and preserved cognition in Morris Water Maze. Our data further exhibits significant decrease of CML (Nε-carboxymethyl lysine) levels in serum and hippocampus byFgSE treatment in comparison with HFD group. Therefore, we deduced that FgSE prevents glycation-induced memory decline via entrapping the reactive carbonyl intermediates, formed during production of AGEs. Hence, as a promising functional food it slows down the harmful process of glycation and aging associated morbidities.