Impaired Processing Research Articles

The influence of drying and storage conditions on the volatilome and cannabinoid content of Cannabis sativa L. inflorescences.

The increasing interest in hemp and cannabis poses new questions about the influence of drying and storage conditions on the overall aroma and cannabinoids profile of these products. Cannabis inflorescences are subjected to drying shortly after harvest and then to storage in different containers. These steps may cause a process of rapid deterioration with consequent changes in precious secondary metabolite content, negatively impacting on the product quality and potency. In this context, in this work, the investigation of the effects of freeze vs tray drying and three storage conditions on the preservation of cannabis compounds has been performed. A multi-trait approach, combining both solid-phase microextraction (SPME) two-dimensional gas chromatography coupled to mass spectrometry (SPME-GC × GC-MS) and high-performance liquid chromatography (HPLC), is presented for the first time. This approach has permitted to obtain the detailed characterisation of the whole cannabis matrix in terms of volatile compounds and cannabinoids. Moreover, multivariate statistical analyses were performed on the obtained data, helping to show that freeze drying conditions is useful to preserve cannabinoid content, preventing decarboxylation of acid cannabinoids, but leads to a loss of volatile compounds which are responsible for the cannabis aroma. Furthermore, among storage conditions, storage in glass bottle seems more beneficial for the retention of the initial VOC profile compared to open to air dry tray and closed high-density polyethylene box. However, the glass bottle storage condition causes formation of neutral cannabinoids at the expenses of the highly priced acid forms. This work will contribute to help define optimal storage conditions useful to produce highly valuable and high-quality products.

Degradation of anti-rust oil film in a simulated coastal atmosphere: inhibition mechanism and in-situ monitoring

Anti-rust oils (ARO) are widely used to inhibit atmospheric corrosion of metal structures, but their degradation mechanisms are unclear, particularly in coastal environments. In this work, we first prepared a kind of ARO made of sodium petroleum sulfonate (SPS) and white oil, then coated the ARO on a mild steel plate to investigate its deterioration process beneath saline water droplets by Quartz crystal microbalance (QCM) and electrochemical mapping techniques. It shows that the SPS concentration is crucial to the ARO inhibition property. When the SPS content is lower than its critical micelle concentration (CMC), saline droplets may intrude the barrier formed by the nonpolar paraffin groups of SPS and then adsorb on the steel surface, resulting in localised corrosion. However, once the SPS content exceeds its CMC, the saline droplets will be emulsified and captured in the oil phase by the reverse micelle effect, thus inhibiting the corrosion of steel substrates. Moreover, the atmospheric corrosion rate of mild steel obeys a power decaying under ARO film. Finally, a capacitive sensor was invented to evaluate the degree of degradation of ARO in situ by dielectric constant measurement.

Temporal Dynamics of Fungal Communities in Alkali-Treated Round Bamboo Deterioration under Natural Weathering

Microbes naturally inhabit bamboo-based materials in outdoor environments, sequentially contributing to their deterioration. Fungi play a significant role in deterioration, especially in environments with abundant water and favorable temperatures. Alkali treatment is often employed in the pretreatment of round bamboo to change its natural elastic and aesthetic behaviors. However, little research has investigated the structure and dynamics of fungal communities on alkali-treated round bamboo during natural deterioration. In this work, high-throughput sequencing and multiple characterization methods were used to disclose the fungal community succession and characteristic alterations of alkali-treated round bamboo in both roofed and unroofed habitats throughout a 13-week deterioration period. In total, 192 fungal amplicon sequence variants (ASVs) from six phyla were identified. The fungal community richness of roofed bamboo samples declined, whereas that of unroofed bamboo samples increased during deterioration. The phyla Ascomycota and Basidiomycota exhibited dominance during the entire deterioration process in two distinct environments, and the relative abundance of them combined was more than 99%. A distinct shift in fungal communities from Basidiomycota dominant in the early stage to Ascomycota dominant in the late stage was observed, which may be attributed to the increase of moisture and temperature during succession and the effect of alkali treatment. Among all environmental factors, temperature contributed most to the variation in the fungal community. The surface of round bamboo underwent continuous destruction from fungi and environmental factors. The total amount of cell wall components in bamboo epidermis in both roofed and unroofed conditions presented a descending trend. The content of hemicellulose declined sharply by 8.3% and 11.1% under roofed and unroofed environments after 9 weeks of deterioration. In addition, the contact angle was reduced throughout the deterioration process in both roofed and unroofed samples, which might be attributed to wax layer removal and lignin degradation. This study provides theoretical support for the protection of round bamboo under natural weathering.

Time-varying damage evolution of concrete under cyclic disturbance loading- an experimental observation utilizing AE and DIC

Cyclic disturbance loading affects the continuous operation of concrete structures. This study aims to better understand the failure behavior of concrete structures under cyclic disturbance loading. This study combined acoustic emission (AE) and digital image correlation (DIC) technologies to study mechanical failure behavior and damage evolution of concrete materials under cyclic disturbance loading and unloading. The AE event time-frequency characteristics, surface principal strain program, and damage parameters of samples with different cyclic disturbance amplitudes were obtained by theoretical calculation. The results reveal that when minor disturbance amplitudes are applied, the elastic modulus of concrete specimens tends to increase. When the disturbance amplitude is too large, the elastic modulus of the specimens drops, leading to faster specimen failure. The AE characteristic parameters exhibit a Felicity effect after the sample is subjected to a cyclic disturbance loading. Moreover, the larger the amplitude of the disturbance load, the more frequent the low-frequency and high-amplitude events generated during the final rupture, the higher the concentration of the principal strain on the sample's surface, and the wider the crack band distribution. AE energy and Effective crack are consistent in characterizing damage, and the changing trend of these two damage parameters can better reflect the deterioration process of concrete. The research results will provide practical and theoretical insights for safely operating and maintaining concrete structures.

Changing Conditions: Global Warming-Related Hazards and Vulnerable Rural Populations in Mediterranean Europe

Human-induced climate change has profound effects on extreme events, particularly those linked to global warming, such as heatwaves, droughts, and wildfires. These events disrupt ecosystems, emphasizing the imperative to understand the interactions among them to gauge the risks faced by vulnerable communities. Vulnerability levels vary primarily based on a community’s resources. Rural areas, especially in the Mediterranean region of Europe, are experiencing acute depopulation, creating a complex situation affecting various aspects of society, from economic declines to cultural heritage loss. Population decline in rural regions weakens resources, leading to the abandonment of built environments, fostering desertification, and elevating the risk of wildfires. Communities undergoing this deterioration process become exceptionally vulnerable, especially when dealing with and recovering from extreme natural phenomena. This review offers insights into the dynamics of these hazards and the predominant challenges in rural areas. By focusing on a topic that has received limited attention, the aim is to inform future research initiatives, ultimately improving risk assessment and mitigation strategies for these vulnerable communities.

Penurunan Mutu Ikan Segar Hasil Budidaya Keramba Jaring Apung Di Teluk Ambon Pada Suhu Kamar

The research was conducted to determine the quality deterioration of several types of fish from floating net cage cultivation in Ambon Bay during a 10-hour of observation period at room temperature. Observations were made on test parameters such as pH, total volatile base (TVB), trimethylamine (TMA), and total microbes (TPC). The results of the analysis showed that over the course of 10 hours at room temperature, the process of quality deterioration in Lates calcarifer was slower compared to Gnathanodon speciosus and Oreochromis niloticus. This is evident in the fish quality parameter values. For instance, the average pH of the three types of fish during room temperature storage ranges from 6.13 to 6.65. The TVB value of G. speciosus and O. niloticus exceeded acceptable levels after 6 hours of storage, while the TVB value of Lates calcarifer remained acceptable even after 6 hours. At six hours, the TVB values exceeded 10 mg N%, indicating spoilage, while the TMA value in L. calcarifer sea bass did not exceed 10 mg N% after 10 hours of storage. The total microbial value of the three fish samples stored for 10 hours at room temperature still meets the standards for fresh fish quality.

Causal chain event graphs for remedial maintenance.

The analysis of system reliability has often benefited from graphical tools such as fault trees and Bayesian networks. In this article, instead of conventional graphical tools, we apply a probabilistic graphical model called the chain event graph (CEG) to represent the failures and processes of deterioration of a system. The CEG is derived from an event tree and can flexibly represent the unfolding of asymmetric processes. For this application, we need to define a new class of formal intervention we call remedial to model the causal effects of remedial maintenance. This fixes the root causes of a failure and returns the status of the system to as good as new. We demonstrate that the semantics of the CEG are rich enough to express this novel type of intervention. Furthermore, through the bespoke causal algebras, the CEG provides a transparent framework with which to guide and express the rationale behind predictive inferences about the effects of various types of remedial intervention. A backdoor theorem is adapted to apply to these interventions to help discover when a system is only partiallyobserved.

Decipherment of text on foxed documents by Hyperspectral Imaging on VSC 6000

Foxing is a process of deterioration that generates spots and browning on ancient paper documents such as books, monographs, postage stamps, certificates, etc. It is believed that metals and bacteria are the primary causes of foxing production. According to scientific studies, physical, chemical, and biological processes degrade paper. Paper is especially prone to biodeterioration processes due to its organic composition and hygroscopic nature; as a result, foxed paper becomes weaker, more fragile, and more acidic than undamaged paper. In circumstances where the text of a book or other document becomes unreadable owing to foxing, measures must be established to make the content readable. In the present study, efforts were made to understand the unreadable text content of books damaged by foxing, and the capabilities of Hyperspectral Image on VSC 6000 employing Near-Infrared Multispectral imaging analysis were presented. It is a method for optimising spectral differences that is non-invasive. First, microbiological flora (fungal and bacterial) from old books were identified, followed by the selection of the mechanism of VSC. The results revealed a correlation between fungal foxing and bacterial foxing, leading to the conclusion that fungus foxing necessitates distinct wavelength ranges between 600 and 800 nm for the decipherment of text, but bacterial foxing allows for decipherment at 645nm. Purchase Article - $10

Theoretical modeling of concrete friction-impact deterioration using water-borne sand abrasion experiment

To explore the influence of impact angle on concrete abrasion deterioration under water-borne sand, a theoretical model for friction-impact deterioration was developed. This model innovatively proposes the inhibition effect of the normal impact action on the tangential friction mass loss and the facilitation effect of the tangential friction action on the normal impact mass loss to rationally explain the effect of impact angle on concrete mass loss. Simultaneously, a water-borne sand accelerated abrasion experiment was conducted to initiate a comprehensive discussion on surface abrasion deterioration indicators, including mass loss, number of holes, aperture, hole area, and hole volume. In addition, the concrete abrasion mass loss rate was evaluated based on the friction-impact deterioration model combined with experimental data. Applying this model facilitates a reliable prediction of concrete's mass loss caused by abrasion. Consequently, this allows for a more accurate assurance of the safety of concrete structures exposed to abrasive conditions throughout their operational life. The results show that the mass loss per unit area, maximum aperture, hole area ratio, and hole volume exhibit a trend of first decreasing, then increasing and finally decreasing with the increase of impact angle. Under 15°, 60°, and 90°, 70 % of the mass loss per unit area of the concrete specimens occurred within the first 6 d of abrasion. When the angles were 30° and 45°, 50 % of the mass loss per unit area of the concrete specimens occurred in the 9–12 d abrasion. It has been revealed that 69° results in the most severe abrasion mass loss. The abrasion deterioration process of concrete can be divided into three primary stages, including surface mortar abrasion, prime aggregate-mortar abrasion, and continuous aggregate-mortar abrasion. Additionally, the friction-impact theoretical model was employed to simulate the abrasion of both single and multiple pier columns, and the simulations provided insights into the non-uniform mass loss rate distribution around the pier columns.

Stability of monovarietal Sicilian olive oils under different storage condition: Chemical composition, sensory characteristics, and consumer preference

Monovarietal olive oils, known for their distinct aromatic profiles, face challenges in preserving their initial quality due to variations in stability and susceptibility to oxidative deterioration. This study focused on the storage stability of two Italian cultivars, ‘Biancolilla’ and ‘Cerasuola’, from Sicily, chosen for their aromatic complexity and divergent storage stability. Oils, whether filtered or unfiltered, underwent storage at two thermal regimes (18 °C and – 20 °C) over a year. The combination of filtration and low-temperature storage was employed to mitigate oxidative deterioration and hydrolytic processes, as filtration removes suspended particles and emulsified water, while low temperatures slow down enzymatic activities and oxidative reactions, thereby enhancing the overall stability and shelf life of the olive oils. Unfiltered samples at room temperature showed a significant increase in secoiridoid aglycone derivatives (Hydroxytyrosol and Tyrosol) due to hydrolytic processes, along with a decrease in secoiridoid aglycone. Filtration delayed these processes, with a more pronounced effect observed when combined with −20 °C storage. Sensory analysis identified the emergence of the “fusty” defect in the less resilient ‘Biancolilla’ cultivar after six months, a phenomenon mitigated by filtration and freezing. Consumer tests validated these findings. In summary, the synergistic approach of combining filtration with low-temperature storage emerges as a promising strategy for maintaining high-quality standards, especially for less stable monovarietal extra virgin olive oils. This strategy ensures compliance with EU regulations beyond the conventional 12-month shelf life, offering a practical solution for preserving the nutritional and sensory quality of olive oil.

Prohibiting pure and saline water infiltration into organic-nano-coated calcium silicate hydrates surface: A nanoscale mechanisms analysis

Extend the lifetime of coated cement paste under severe environment is a big challenge and the most crucial problems are related the degradation in the interface between coating and cement paste. This work is devoted to an in-depth investigation under aggressive environment of the deterioration process between epoxy coating and nano-granular Calcium-Silicate-Hydrate (CSH) paste. Further, a depth analyze of what properties make an organic-coating (epoxy and rubber) impermeable is established by means of Molecular Dynamics simulations (MD). Results indicate that the chlorine ions are responsible to attack the epoxy resins coating and CSH surface. Non-fully epoxy coating is detached more distorted in salty solution (4 wt% of NaCl) than in pure water solution. The Casurface-Oepoxy and Casurface-NMPD are the two bonds responsible for the bonding strength of epoxy resins coating and CSH surface. It is found that both the pore structure and the big surface roughness in organic-coating could accelerate the degradation in the interface. The water sorption in the permeable epoxy coating is increasing within time, in agreement with experimental investigations. Nevertheless, a continuous well-distributed rubber nano-coating is capable to make CSH impermeable under harsh environment. The obtained diffusion coefficient is decreased by 12.26 % in 4 wt% of NaCl solution.

A deep dive into green infrastructure failures using fault tree analysis

Green Infrastructure has transformed traditional urban stormwater management systems by fostering a wide range of service functions. Despite their popularity, green infrastructure's performance can deteriorate over their lifecycle, leading to operational failures. The operation of green infrastructure has predominantly relied on reactive maintenance strategies. To anticipate malfunctions and enhance the performance of green infrastructure in the long run, failure data needs to be recorded so that deterioration processes and component vulnerabilities can be recognized, modelled and included in predictive maintenance schemes. This study investigates possible failures in representative GIs and provides insights into the most important events that should be prioritized in the data collection process. A method for qualitative Fault Tree Analysis using minimal cut sets are introduced, aiming to identify potential failures with the minimum number of events. To identify events of interest fault trees were constructed for bioswales, rain gardens and green roofs, for three groups of service function failures, namely runoff quantity control, runoff quality control and additional service functions. The resulting fault trees consisted of 45 intermediate and 54 basic events. The minimal cut set analysis identified recurring basic events that could affect operation among all three green infrastructure instances. These events are ‘trash accumulation’, ‘clogging due to sediment accumulation’, and ‘overly dense vegetation’. Among all the possible cut sets, events such as ‘plants not thriving’, ‘invasive plants taking over’, and ‘deterioration caused by external influences’ could potentially disrupt most of the service functions green infrastructure provides. Furthermore, the analysis of interactions between component failures shows vegetation and filter media layer failures have the highest influence over other components. The constructed fault trees and identified basic events could be potentially employed for additional research on data collection processes and calculating the failure rates of green infrastructure and as a result, contribute to a shift toward their proactive operation and maintenance.

Deterioration Models and Service Life Prediction of Vertical Assets of Urban Water Systems

AbstractThis study proposes a methodology for developing deterioration models and predicting the service lives of vertical assets of urban water systems (i.e., water storage tanks and pumping stations) using regression analysis. The main factors contributing to the deterioration of these assets are analyzed. Simple and multiple linear regression models of average and maximum deterioration are calculated for 22 water storage tanks and 17 wastewater pumping stations. Data on a set of four water storage tanks are used to validate the developed deterioration models. Service life prediction is carried out using the developed models and considering two maximum deterioration levels: the maximum recommended and admissible deterioration levels. Two water storage tanks are further studied to illustrate and discuss the effect of maintenance and rehabilitation interventions on asset service life by comparing the asset deterioration before and after the interventions. Results include simple linear regression models of average and maximum deterioration indices as a function of asset age and multiple linear regression models that incorporate other physical, operational and environmental factors. The results show that simple linear regression models of asset deterioration show a better predictive power than multiple regression models. Despite the higher data variability of multiple regression models, these models allow to include the random process of asset deterioration, through the calculation of the standard deviation. This study also shows that periodic interventions are a preferable maintenance and rehabilitation strategy over major sporadic rehabilitation interventions since it allows to maintain assets in good condition and to extend their service life almost indefinitely.

Deterioration Mechanism and Status Prediction of Hydrocarbon Lubricants under High Temperatures and Humid Environments

In practical engineering applications, high temperatures and water ingress seriously affect the service life of hydrocarbon lubricants. In this study, the deterioration process of hydrocarbon lubricants under high temperatures and humid environments was investigated, and a new health state prediction model was proposed. Simulation of hydrocarbon lubricant Polyalpha−olefin (PAO) molecules used the ReaxFF force field to analyse the high temperature thermal oxidation process of lubricants. The rheological properties of oil−water emulsions were determined by observing the morphology of oil−water two−phase mixtures with different water contents. A multiparameter fusion viscosity prediction model was proposed using a linear model of the viscosity of aqueous fluids, as affected by temperature and water content, and was fitted with the Andrade viscosity−temperature equation to predict lubricant viscosity changes under multiple parameters. Online validation tests were carried out on a compound planetary transmission system, and the surface topographical parameters of the transmission components were further discussed. Experimental results show that the linear correlation with the improved lubricant viscosity prediction model is 0.966, and the surface wear of transmission components is consistent with the trend of lubricant quality change. These findings provide a fundamental basis for the assessment of lubricant service life in high temperatures and humid environments.

From risk study to field evidence: an unprecedented and isolated case of DEF in Brazil

This paper presents the first case ever reported in Brazil where delayed ettringite formation (DEF) has been confirmed as the sole cause of deterioration in field concrete. Still under construction and with less than 2 years of age, numerous cracks were observed in the foundation structures of a building located in Recife, a city known for its history of alkali-aggregate reaction (AAR) cases. In addition to the field survey of cracks, microstructural analyses, residual expansion, compressive strength, review of structural design, the determination of the sulfates content in the groundwater and simplified thermal analysis were carried out. Results confirmed that the DEF was the isolated cause of the damages present in those cast-in-place concrete structures, with no evidence of AAR or any other deterioration process. This work corroborates studies previously published on the high risk of the occurrence of DEF in the region, demonstrating the urgent need for a preventive technical standard in the country, considering the chemical composition of cements and mainly prior thermal analyzes to adopt possible preventive measures to limit the maximum internal temperature of the concrete.

A forgotten structure in the rural setting of Kastamonu/Turkey: Documentation, restitution and restoration proposal for Mehran Mosque

Especially in rural areas, where the deterioration process of religious structures is rapid, it is necessary to undertake efforts for their preservation and restoration. The main reason for this is the scarcity of similar examples due to the region-specific nature of mosque structures in rural areas. The fundamental problem addressed in the research is the rapid deterioration and impending disappearance of structures in rural areas due to declining population and subsequent abandonment. Documentation processes for Mehran Mosque located in Hacımuharrem Village of Kastamonu province were carried out in the study, and restoration and restitution proposals were put forward. Additionally, the structural stability of the mosque was analyzed to assess its behavior under seismic impact. The study concluded that there were no structural issues found, indicating that the mosque could be restored and utilized promptly. However, it is essential not only to make the structure usable individually but also to evaluate it within its surroundings. The study is significant in understanding the adverse effects of population decline on historical buildings. Furthermore, the fact that the selected structure has been preserved in its original state and was built during the same period as Mahmut Bey Mosque also adds importance to the study.

Curcumin and silver nanoparticles loaded antibacterial multifunctional pectin/gelatin films for food packaging applications

Renewable biomass-based materials have a huge potential to replace petroleum-based products in food packaging. Herein, pectin/gelatin films loaded with curcumin and silver nanoparticles (AgNPs) are prepared by solution-pouring technology to serve as antimicrobial multifunctional food packaging films. AgNPs and curcumin are found to equally distribute in the films. Fourier transform infrared spectroscopy (FT-IR) reveal the hydrogen bonding and electrostatic interaction among curcumin, AgNPs, pectin and gelatin. The composite films show good antioxidant activity, mechanical performance, hydrophobicity and antibacterial ability. The films of P-GCA 0.5 showed 99.57 ± 0.16 % and 100 % inhibition against E. coli and S. aureus, respectively. The films also demonstrate excellent water vapor barrier qualities. In addition, the composite films possess pH-responsive color change behaviors from yellow (pH 3–8) to light red (pH 8–9) to dark red (pH 11–12), which is suitable for monitoring the freshness of shrimp packaging based on pH changes during deterioration process. As sustainable biomass-based materials, the multifunctional composite films are promising in intelligent food packaging applications.

Evaluation of Material Characteristics and Structural Dynamic Properties of a Historical Church: The Case of 19th Century Bursa Derekoy Church (Ayia Paraskevi)

Derekoy (Ayia Paraskevi) Church, built by the Orthodox Greeks in Bursa, is one of the prominent monuments built in the 19th century. The structure, which lost its community with the population exchange (1923) between Turkey and Greece, has since then been out of service and a rapid deterioration process has begun. Analysis works are frequently implemented for this purpose and become crucial in Turkey, of which a large part is within the earthquake zone. However, the majority of the studies on the preservation of historical buildings are lacking in detailed material analysis and numerical methods. Conducting a series of material tests and numerical analyses for the structure provides more reliable and qualified interventions since they influence the decisions on the reinforcement and protection methods employed for historical buildings. For this purpose, the material characterizations of the mortar, plaster and stones used in the church were carried out by performing physical, chemical, mechanical, petrographic and mineralogical tests on samples taken from the church. Afterwards, mechanical tests of the walls and vibration tests were conducted to determine the dynamic behavior of the building. Based on the results obtained from the analyses, a series of intervention methods were proposed. It is understood that the flat-jack, shear and vibration tests are vital for determining the real structural behavior of the building. Furthermore, it is recommended that vibration tests are carried out on both the overall structure and individual walls to determine the dynamic behavior of similar structures where only outer walls remain standing.  

Degradation modeling and reliability estimation for mechanical transmission mechanism considering the clearance between kinematic pairs

The mechanical transmission mechanism is the core component of electromechanical systems, of which the health state can affect the accuracy and stability of the entire system. Due to machining errors and thermal deformation, clearance often exists between the kinematic pairs, which leads to irregular collision- separation during the operation. The clearance size and the surface quality of pairs change during the service life, leading to the time-varying damage and degradation state of the mechanism. Therefore, the kinematic pairs suffer from not only natural deterioration process such as wear, fatigue, etc., but also the collision-separation process caused by the clearance. In this paper, a degradation and shock model for the mechanical transmission mechanism is proposed considering the influence of clearance between the kinematic pairs. The degradation process is divided into running-in stage, stable degradation stage, and fast degradation stage according to the health states, and is modeled by a transformed gamma process to account for the dependency between service time and health state. Random shocks caused by the collision-separation process are classified into different zones in terms of their sizes, and the arrival rate of the shocks also change with the health state of the mechanism. The closed-form reliability function is derived and verified by the experiment of rotating pair of the crank and rocker mechanism. Results show that the proposed degradation and shock model can obtain a more realistic and reasonable reliability of the transmission mechanism.

Abstract 4398: TET2 accelerates clonal hematopoiesis in an age-dependent manner

Abstract Aging is a process of systemic deterioration and the most significant risk factor for cancers. Clonal hematopoiesis (CH) commonly occurs with aging and links to higher mortality, leukemia risk, and cardiovascular diseases. Age-related CH involves the abnormal clonal expansion of hematopoietic stem cells (HSCs) bearing somatic mutations in genes frequently mutated in leukemia, including genes encoding epigenetic regulators, such as the DNA demethylase TET2. While such mutations are known to alter the HSC epigenome, the mechanisms through which these mutations drive HSC self-renewal, myeloid transformation, and inflammatory response remain elusive. In this study, we hypothesize that aging and CH mutations cooperatively reshape the HSC transcriptomic landscape and enhancing HSC competitive advantage that facilitates clonal expansion. Recently, TET2-mutant CH in humans has been strongly associated with epigenetic age acceleration. Using single-cell multi-omic analyses and flow-cytometric phenotyping, we demonstrated, for the first time, that HSC aging processes at transcriptomic, epigenomic, and cellular levels are accelerated by Tet2 deficiency in mice, in an age-dependent manner. Tet2-deficient HSCs increase the HSC aging scores at an older age of greater than or equal to 16 months, but not at a young or mid-age, based on gene expression and chromatin accessibility at a single-cell resolution. This age acceleration was further validated by epigenetic clock analysis of DNA methylation mapping. Moreover, we found that Tet2 deficiency drives a significant expansion of HSCs, a cellular hallmark of HSC aging, in an age-dependent manner. Specifically, we observed increased expression of S100a6, Cdk6, Egr1 in Tet2-deficient HSCs from older mice, suggesting that Tet2 deficiency hijacks the HSC expansion strategy during HSC aging by enhanced self-renewal. We also observed that the differentially expressed genes between Tet2-deficient older HSCs and control older HSCs are associated with open chromatin accessibility. Many of these genes are enriched in the targets of specific transcription factors (TFs), such as Egr1, Creb1, Stat family and Hoxb8. These target genes play critical roles in inflammatory pathways and HSC functions. In conclusion, our findings reveal that Tet2 deficiency significantly contributes to the acceleration of HSC aging, and hijacks the HSC expansion strategy (e.g., self-renewal) during HSC aging, which exacerbates age-related clonal hematopoiesis. By elucidating the transcriptomic and epigenomic alterations in Tet2-deficient HSCs, our study provides novel insights into how age and somatic mutations collaborate to promote the pathogenesis of age-related hematological diseases. These discoveries not only enhance our understanding of HSC aging mechanisms but also offer potential biomarkers for early detection and targets for therapeutic intervention in age-associated clonal disorders. Citation Format: Shilpita Karmakar, Yang Liu, Efthymios Motakis, Kaustav Sengupta, Travis Roeder, Kristina Mujica, Jennifer Trowbridge, Hideyuki Oguro, Sheng Li. TET2 accelerates clonal hematopoiesis in an age-dependent manner [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4398.