Stress Recovery Research Articles

Creating restorative corridors - Perceptual and physiological feedback of children on the audiovisual environment in primary school corridors

The corridor space of the primary school campus is frequently used for recess and relaxation by the students, which brings stress and emotional recovery from the intense academic work. How to integrate natural restorative environment into the corridor has attracted academic and practical attention. Based on Kaplan's theory of Restorative Environment, this study combined subjective evaluation with physiological feedback to explore the primary school children's perception and evaluation of corridor space, and proposed the effects of different audio-visual indicators. Based on a questionnaire survey of children's activities and restoration in two schools, the paper found the association between perceived restoration and high interaction behavior in the corridor, including floriculture and interacting with hands-on devices. The richness of amenities and colors in the corridor space had the highest correlation with children's restorative ratings, followed by interface openness and sky visibility. Natural soundscapes also had a strong correlation with children's auditory restorability. Subsequent virtual audition experiments validated above findings, suggesting the benefits of increased greenery, sky and natural sounds in reducing children's stress.

Enhanced recovery after bariatric surgery: a comprehensive survey-based analysis of ERABS actual clinical implementation in Italian bariatric centers.

The escalating global prevalence of bariatric procedures necessitates an enhanced focus on optimizing perioperative care for improved patient outcomes. This study focuses on the implementation of Enhanced Recovery After Bariatric Surgery (ERABS) protocols in Italian bariatric centers to optimize perioperative care. An online survey comprising 19 items was conducted in October 2023, targeting managing surgeons in 139 registered bariatric centers. This survey explored geographic and center-type variations, knowledge, and application of ERABS protocols, along with perioperative, intraoperative, and postoperative practices. Statistical analysis employed included one-way ANOVA and Tukey post hoc tests. Responses from 72 centers (51.8%) revealed a strong awareness of ERABS protocols among managing surgeons. Adherence rates varied geographically (46.3-63%) and among center types (60.8-56.3%). Perioperative practices, including the abandonment of antibiotics for perioperative prophylaxis by 77.5% of surgeons and the adoption of the TAP block technique in 69% of centers, aligned well with ERABS recommendations. However, inconsistencies were noted in abdominal drain usage (61.5% after SG; 70.5% after RYGB/OAGB), with a substantial percentage not adhering to ERABS guidelines. Intraoperative habits generally adhered to ERABS protocols, yet preferences for certain tests, particularly the methylene blue test (70.4%), deviated. Postoperative practices displayed positive trends, with early reintroduction of oral feeding (71.8%) and opioid-free pain management (71.8%). Variations existed in discharge timing and patient monitoring, indicating areas for further improvement. This study offers a comprehensive snapshot of ERABS protocol adherence in Italy, emphasizing the positive trend toward optimizing recovery and reducing patient stress. Despite variations, a majority of centers demonstrated commitment to ERABS principles. Ongoing education, interdisciplinary collaboration, and nationwide dialogue are essential for standardizing ERABS protocols and advancing bariatric-metabolic surgery outcomes in Italy.

Physical and numerical tests on adjustable–height structures of high–speed railway transition section

The disparity in stiffness and differential settlement between the subgrade and rigid structures can lead to track irregularities within transition sections, resulting in significant train vibrations and impacts. This study proposes an adjustable–height subgrade structure for transition sections by introducing a raft slab to divide the subgrade into upper and lower parts. When settlement occurs in the subgrade, the raft slab can be elevated using height–adjustment techniques to compensate for the settlement. To this end, large–scale physical model tests are conducted under train loading to verify the design's rationality and to elucidate the influence of settlement magnitude and train speed on the stress and deformation of the slab. The experimental results indicate that the maximum principal stress and maximum shear stress of the slab generally increase with settlement magnitude and train speed, and the area near the abutment end is the most unfavorable position for the deformation of the slab. However, it is still lower than the design compressive strength of the C40 concrete structure. Thus, the designed adjustable–height structure meets the load–bearing requirements under train loading. Additionally, a numerical simulation model of the adjustable–height structure is developed to investigate the recovery capabilities and stress distribution of the settled raft slab. The results indicated that whether the lifting operation employed linear load or equal load methods, the raft slab primarily endured compressive stress, and there is stress concentration at the lifting points. For the same lifting displacement, the linear load method proved to be more reasonable than the equal load method. These findings have significant practical and theoretical implications for ensuring the safe and smooth operation of high–speed railways, effectively addressing the post–construction settlement deformation control challenges in ballastless track transition sections.

Bibliometric analysis of the inflammation expression after spinal cord injury: current research status and emerging frontiers.

Bibliometric analysis. To analyze literature on inflammatory expression following spinal cord injury, highlighting development trends, current research status, and potential emerging frontiers. Not applicable. Articles were retrieved using terms related to spinal cord injury and inflammatory responses from the Web of Science Core Collection, covering January 1, 1980, to May 23, 2024. Tools like CiteSpace and VOSviewer assessed the research landscape, evaluating core authors, journals, and contributing countries. Keyword co-occurrence analyses identified research trends. A total of 2504 articles were retrieved, showing a consistent increase in publications. The Journal of Neurotrauma had the highest publication volume and influence. The most prolific author was Cuzzocrea S, with Popovich PG having the highest H-index. China led in the number of publications, followed closely by the United States, which had the highest impact and extensive international collaboration. Research mainly focused on nerve function recovery, glial scar formation, and oxidative stress. Future research is expected to investigate cellular autophagy, vesicular transport, and related signaling pathways. The growing interest in inflammation caused by spinal cord injury is evident, with current research focusing on oxidative stress, glial scar, and neurological recovery. Future directions include exploring autophagy and extracellular vesicles for new therapies. Interdisciplinary research and extensive clinical trials are essential for validating new treatments. Biomarker discovery is crucial for diagnosis and monitoring, while understanding autophagy and signaling pathways is vital for drug development. Global cooperation is needed to accelerate the application of scientific findings, improving spinal cord injury treatment.

Back‐Propagating Rupture: Nature, Excitation, and Implications

AbstractRecent observations show that certain rupture phase can propagate backward relative to the earlier one during a single earthquake event. Such back‐propagating rupture (BPR) was not well considered by the conventional earthquake source studies and remains a mystery to the seismological community. Here we present a comprehensive analysis of BPR, by combining theoretical considerations, numerical simulations, and observational evidences. First, we argue that BPR in terms of back‐propagating stress wave is an intrinsic feature during dynamic ruptures; however, its signature can be easily masked by the destructive interference behind the primary rupture front. Then, we propose an idea that perturbation to an otherwise smooth rupture process may make some phases of BPR observable. We test and verify this idea by numerically simulating rupture propagation under a variety of perturbations, including a sudden change of stress, bulk or interfacial property and fault geometry along rupture propagation path. We further cross‐validate the numerical results by available observations from laboratory and natural earthquakes, and confirm that rupture “reflection” at free surface, rupture coalescence and breakage of prominent asperity are very efficient for exciting observable BPR. Based on the simulated and observed results, we classify BPR into two general types: interface wave and high‐order re‐rupture, depending on the stress recovery and drop before and after the arrival of BPR, respectively. Our work clarifies the nature and excitation of BPR, and can help improve the understanding of earthquake physics, the inference of fault property distribution and evolution, and the assessment of earthquake hazard.

Rheological and mechanical evaluation of a novel fast curing cold asphalt concrete made with asphalt emulsion, by-products and magnetic induction

This work studies the feasibility of a new cold asphalt concrete with 5 % voids with fast curing, developed with asphalt emulsion and magnetic induction. Until now, it was impossible to produce fast curing cold asphalt concretes due to the impossibility of compacting and evaporating the water in the asphalt emulsion quickly. Therefore, the aim of this work is to solve the impossibility of compacting the cold asphalt concrete and thus reduce the long curing times. For this purpose, at laboratory level, an experimental cold asphalt concrete was designed with magnetic induction and compared with two reference hot asphalt concretes manufactured according to Spanish standards without magnetic induction (one with 50–70 grade bitumen and another with a PMB45/80–65 type polymer-modified bitumen). The research was carried out in two stages. First, the new cold asphalt concrete was rheologically characterized, the binder recovered from the asphalt concrete was analyzed according to the tests of ring and ball, penetration, dynamic shear rheometer (DSR) and multiple stress creep and recovery (MSCR). Secondly, the new cold concrete asphalt was mechanically characterized, the mechanical performance of the cold asphalt concrete was analyzed by evaluating stability and deformation, dry and wet indirect tensile strengths (ITS), wheel tracking test, stiffness modulus and resistance to raveling dry and wet conditions. Based on the rheological analysis results, the asphalt emulsion recovered from the cold asphalt concrete is extremely soft with a low softening point and a high penetration rate. On the other hand, the values of viscosity, phase angle, stiffness and non-recoverable creep compliance are between those of the bitumen 50/70 and the PMB45/80–65, but closer to bitumen 50/70. As for their mechanical performance, the novel cold asphalt concrete studied presents better resistance to water damage and particle loss, both in dry and wet conditions, but also high permanent deformations and low ITS, probably due to the fact that the residual binder of the emulsion used is softer than the others.

The influence of non-Newtonian behaviors of blood on the hemodynamics past a bileaflet mechanical heart valve

This study employs extensive three-dimensional direct numerical simulations to investigate the hemodynamics around a bileaflet mechanical heart valve. In particular, this study focuses on assessing whether non-Newtonian rheological behaviors of blood, such as shear-thinning and yield stress behaviors, exert an influence on hemodynamics compared to the simplistic Newtonian behavior under both steady inflow and physiologically realistic pulsatile flow conditions. Under steady inflow conditions, the study reveals that blood rheology impacts velocity and pressure field variations, as well as the values of clinically important surface and time-averaged parameters like wall shear stress (WSS) and pressure recovery. Notably, this influence is most pronounced at low Reynolds numbers, gradually diminishing as the Reynolds number increases. For instance, surface-averaged WSS values obtained with the non-Newtonian shear-thinning power-law model exceed those obtained with the Newtonian model. At Re=750, this difference reaches around 67%, reducing to less than 1% at Re=5000. Correspondingly, pressure recovery downstream of the valve leaflets is lower for the shear-thinning blood than the constant viscosity one, with the difference decreasing as the Reynolds number increases. On the other hand, in pulsatile flow conditions, jets formed between the leaflets and the valve housing wall are shorter than steady inflow conditions. Additionally, surface-averaged wall shear stress and blood damage (BD) parameter values are higher (with differences more than 13% and 47%, respectively) during the peak stage of the cardiac cycle, especially for blood exhibiting non-Newtonian yield stress characteristics compared to the shear-thinning or constant viscosity characteristics. Therefore, blood non-Newtonian behaviors, including shear-thinning and yield stress behaviors, exert a considerable influence on the hemodynamics around a mechanical heart valve. All in all, the findings of this study demonstrate the importance of considering non-Newtonian blood behaviors when designing blood-contacting medical devices, such as mechanical heart valves, to enhance functionality and performance.

Effect of Laparoscopic Inguinal Hernia Repairs on Inflammatory Factors, Oxidative Stress Levels and Postoperative Recovery.

To unravel the effects of different laparoscopic inguinal hernia repairs (IHRs) on inflammatory factors, oxidative stress, and postoperative recovery of inguinal hernia (IH) patients. A total of 88 patients for laparoscopic treatment of IH were studied in a retrospective cohort, and were randomized into the transabdominal preperitoneal (TAPP) repair group (n = 44) and the total extraperitoneal (TEP) repair group (n = 44) according to the method of treatment. Patients in the TAPP group underwent laparoscopic TAPP IHR, while patients in the TEP group underwent laparoscopic TEP IHR. Visual analogue scores (VAS) were measured at 1, 3, and 7 d after repair. Gastrin (GAS), motilin (MTL), matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinases-1 (TIMP-1) were assessed by enzyme-linked immunosorbent assay. Superoxide dismutase (SOD) was tested by spectrophotometry and malondialdehyde (MDA) and β-endorphin (β-EP) were examined by radioimmunoprecipitation. Total antioxidant capacity (T-AOC) was evaluated by chemical colorimetry, quality of life was evaluated by SF-36, and fibrinogen (FIB), C-reactive protein (CRP), antitrypsin (al-AT), and interleukin-6 (IL-6) levels were determined by immunoturbidimetry. Complications and postoperative recurrence were recorded. VAS scores in the TEP group were lower than those in the TAPP group. Operative time, hospital stay, time for postoperative activity out of bed, and time taken to exhaust were shorter in the TEP group than in the TAPP group. Intraoperative blood loss was less in the TEP group than in the TAPP group. GAS, MTL, SOD, and T-AOC were higher, and MDA, β-EP, CRP, FIB, alAT, IL-6, MMP-2, MMP-9, and TIMP-1 were lower in the TEP group than the TAPP group. Quality of life was improved in the TEP group compared with the TAPP group. There was no significant difference in the rate of postoperative complications and recurrence rates between both groups of patients. For IHs, laparoscopic TEP repair can effectively relieve pain, reduce inflammatory factors and oxidative stress indices, and facilitate postoperative recovery.

Comparison between three different delivery technologies of virtual nature on psychological state related to general stress recovery: An experimental study

Visiting nature has been shown to have several benefits for psychological state related to general stress recovery. However, for many people, access to nature is limited. Technological development has made it possible to deliver nature environments virtually. The present study examines the benefits of a same virtual nature (forest) environment delivered through different technologies on psychological state related to general stress recovery, more precisely, on restoration, current stress, subjective vitality, and affective response. The main focus is on comparing three different delivery technologies of virtual nature: TV (75″), VR headset (Meta Quest 2), and virtual nature room (30m2). The study applies a three-condition randomized trial with pre-post assessments and a crossover design, where 62 participants visited once in each condition for a 15-minute exposure of virtual nature (360-degree video with congruent soundscape). The participants responded to psychological measures before and after each condition. Overall, participants’ restoration increased, while current stress and negative affect decreased during the exposure. In comparison to the TV (control) condition, both the VR headset condition and the virtual nature room condition had a better impact on psychological state related to general stress recovery, as restoration and subjective vitality increased more. There were no statistically significant differences between the VR headset and virtual nature room conditions in any of the measures.

Redox control of the deubiquitinating enzyme Ubp2 regulates translation during stress

Protein ubiquitination is essential to govern cells’ ability to cope with harmful environments by regulating many aspects of protein dynamics from synthesis to degradation. As important as the ubiquitination process, the reversal of ubiquitin chains mediated by deubiquitinating enzymes (DUBs) is critical for proper recovery from stress and re-establishment of proteostasis. Although it is known that ribosomes are decorated with K63-linked polyubiquitin (K63-ub) chains that control protein synthesis under stress, the mechanisms by which these ubiquitin chains are reversed and regulate proteostasis during stress recovery remain elusive. Here, we showed in budding yeast that the DUB Ubp2 is redox-regulated during oxidative stress in a reversible manner, which determines the levels of K63-ub chains present on ribosomes. We also demonstrate that Ubp2 can cleave single ubiquitin moieties out of chain and its activity is modulated by a series of repeated domains and the formation of disulfide bonds. By combining cellular, biochemical, and proteomics analyses, we showed that Ubp2 is crucial for restoring translation after stress cessation, indicating an important role in determining the cellular response to oxidative stress. Our work demonstrates a novel role for Ubp2, revealing that a range of signaling pathways can be controlled by redox regulation of DUB activity in eukaryotes, which in turn will define cellular states of health and diseases.

Ag-S coordination strategy for high recovery driving stress in recyclable shape memory polymers

To address the issue of low strength and recovery stress in recyclable shape memory polymer (SMP) materials with dynamic covalent bonds in practical applications, we propose a method based on Ag-S coordination interactions to improve dynamic covalent bonds, thereby preparing recyclable SMP with high recovery stress and large recovery strain. The introduction of in situ reduced silver nanoparticles (AgNPs) in the SMP system play multiple roles, serving as additional physical crosslinking points at the microscale and coordinating with disulfide bonds in the system to construct a multi-level dynamic network structure. This endows the material with exceptional mechanical properties (tensile strength of 25.93 MPa and fracture strain of 1466.83 %) and recovery driving stress (5.59 MPa), while maintaining more than 99 % shape recovery and fixity rate. Furthermore, due to the outstanding photothermal performance of AgNPs, the composite material has acquired remote photothermal driving capabilities. The proposed Ag-S coordination enhancement offers a new approach for SMP materials that achieve both large actuation distance and high recovery stress, holding significant potential for applications in soft robotics and actuators.

Physiological and Transcriptomic Characterization of Rice Genotypes under Drought Stress

Drought is a primary abiotic stress that inhibits rice (Oryza sativa L.) growth and development, and during the reproductive stage it has a negative impact on the rice seed-setting rate. This research study examined two rice lines, La-96 (drought sensitive) and La-163 (drought resistant), for drought stress treatment (with soil moisture at 20% for 7 days) and control (normal irrigation and kept soil moisture ≥40%). To elucidate the photosynthesis and molecular mechanisms underlying drought tolerance in rice, leaf photosynthetic traits and transcriptome sequencing were used to compare differences between two contrasting recombinant inbred lines (RIL) during drought and subsequent recovery at the booting stage. The rice line La-96 showed a significant decrease in seed-setting rate after being treated for seven days’ drought stress (from 86.64% to 22.75%), while La-163 was slightly affected (from 89.04% to 79.33%). The photosynthetic activities of both lines significantly decreased under the drought treatment, and these traits of La-163 recovered to a comparable level with the control after three days of rewatering. The transcriptome of both lines in three treatments (the control, drought stress, and subsequent recovery) were tested, and a total of 16,051 genes were identified, among which 10,566 genes were differentially expressed in various treatments and rice lines. Comprehensive gene expression profiles revealed that the specifically identified DEGs were involved in the ribosome synthesis and the metabolic pathway of photosynthesis, starch, and sucrose metabolism. The DEGs that are activated and respond quickly, as seen during recovery in the tolerant rice line, may play essential roles in regulating subsequent growth and development. This study uncovered the molecular genetic pathways of drought tolerance and extended our understanding of the drought tolerance mechanisms and subsequent recovery regulation in rice.

Effects of the Acoustic-Visual Indoor Environment on Relieving Mental Stress Based on Facial Electromyography and Micro-Expression Recognition

People working and studying indoors for a long time can easily experience mental fatigue and stress. Virtual natural elements introduced into indoor environments can stimulate the human visual and auditory senses, thus relieving psychological stress. In this study, stress induction was achieved through noise playback, and the recovery effects on psychological stress of three set indoor environments, visual, auditory, and audio-visual, were investigated through changes in subjects’ facial expressions, electromyographic (EMG) signals, and subjective questionnaires. The experiment found that after stress induction through noise, the participants’ stress levels changed significantly. At this time, the subject scored low on the questionnaire, with electromyography readings higher than usual, and micro-expression recognition indicated negative emotions. After the restoration effects under the three working conditions of visual, auditory, and audio-visual combination, the average EMG values during the recovery period decreased from the baseline period (10 min after the subject acclimated to the environment), respectively. The results indicate that all three restoration conditions have the effect of relieving psychological stress, with the stress recovery effects of auditory and audio-visual conditions being superior to visual conditions. This study is of great significance for creating comfortable indoor environments and minimizing psychological pressure on indoor office workers.

Quercus glauca Acorn Seed Coat Extract Promotes Wound Re-Epithelialization by Facilitating Fibroblast Migration and Inhibiting Dermal Inflammation.

The skin, recognized as the largest organ in the human body, serves a vital function in safeguarding against external threats. Severe damage to the skin can pose significant risks to human health. There is an urgent requirement for safe and effective therapies for wound healing. While phytotherapy has been widely utilized for various health conditions, the potential of Quercus glauca in promoting wound healing has not been thoroughly explored. Q. glauca is a cultivated crop known for its abundance of bioactive compounds. This study examined the wound-healing properties of Quercus glauca acorn seed coat water extract (QGASE). The findings from the study suggest that QGASE promotes wound closure in HF cells by upregulating essential markers related to the wound-healing process. Additionally, QGASE demonstrates antioxidant effects, mitigating oxidative stress and aiding in recovery from injuries induced by H2O2. In vivo experiments provide additional substantiation supporting the efficacy of QGASE in enhancing wound healing. The collective results indicate that QGASE may be a promising candidate for the development of innovative therapeutic strategies aimed at enhancing skin wound repair.

Evaluating waterlogging stress response and recovery in barley (Hordeum vulgare L.): an image-based phenotyping approach

Waterlogging is expected to become a more prominent yield restricting stress for barley as rainfall frequency is increasing in many regions due to climate change. The duration of waterlogging events in the field is highly variable throughout the season, and this variation is also observed in experimental waterlogging studies. Such variety of protocols make intricate physiological responses challenging to assess and quantify. To assess barley waterlogging tolerance in controlled conditions, we present an optimal duration and setup of simulated waterlogging stress using image-based phenotyping. Six protocols durations, 5, 10, and 14 days of stress with and without seven days of recovery, were tested. To quantify the physiological effects of waterlogging on growth and greenness, we used top down and side view RGB (Red-Green-Blue) images. These images were taken daily throughout each of the protocols using the PSI PlantScreen™ imaging platform. Two genotypes of two-row spring barley, grown in glasshouse conditions, were subjected to each of the six protocols, with stress being imposed at the three-leaf stage. Shoot biomass and root imaging data were analysed to determine the optimal stress protocol duration, as well as to quantify the growth and morphometric changes of barley in response to waterlogging stress. Our time-series results show a significant growth reduction and alteration of greenness, allowing us to determine an optimal protocol duration of 14 days of stress and seven days of recovery for controlled conditions. Moreover, to confirm the reproducibility of this protocol, we conducted the same experiment in a different facility equipped with RGB and chlorophyll fluorescence imaging sensors. Our results demonstrate that the selected protocol enables the assessment of genotypic differences, which allow us to further determine tolerance responses in a glasshouse environment. Altogether, this work presents a new and reproducible image-based protocol to assess early stage waterlogging tolerance, empowering a precise quantification of waterlogging stress relevant markers such as greenness, Fv/Fm and growth rates.

Hair cortisol sampling as a measure of physiological stress in youth with acute musculoskeletal pain

Stress physiology contributes to health outcomes. Hair cortisol concentration (HCC) is an objective measure of cumulative cortisol secretion associated with health, including pain. The aim of the current study was to describe associations between pre-injury stress physiology (as measured by HCC), acute pain characteristics and relevant demographic factors (i.e., BMI, age, sex, days since injury) in youth with an acute musculoskeletal (MSK) injury. Participants were 58 youth aged 11 to 17 with acute MSK pain. Participants completed self-report measures assessing pain intensity, pain catastrophizing, and pain interference. Hair was collected within 1 month after injury using hair cortisol collection procedures adapted from published research protocols. Correlations examining associations among HCC values and clinical/demographic factors revealed that higher HCC was associated with lower body mass index (BMI) and male sex. HCC was not associated with pain variables or age. Additional research is needed to clarify the relation between HCC and psychosocial variables to aid researchers in studying the role of pre-injury stress in acute MSK injury and pain recovery in youth.

The numerical simulation study on the Fe-SMA-strengthened PCCP with broken wires

This paper conducted a full-scale experiment on a PCCP with an inner diameter of 1400 mm and a length of 6000 mm. A finite element model was established on the basis of this experiment, and the influence of different recovery stresses, Fe-SMA bar diameters, and material types on the strengthening effect was investigated. The simulation results indicated a notable enhancement in the strengthening effect upon employing Fe-SMA bars with recovery stresses of 0 MPa, 175 MPa, 330 MPa, and 382 MPa, respectively. With the increased recovery stress, the micro-cracking pressure enhanced 33.8 %, 51.5 %, 72.1 %, and 80.9 % and the visible cracking pressure enhanced 12 %, 24.8 %, 31.6 %, and 33.1 %, respectively, compared to the non-strengthened PCCP. Finally, this paper proposed a design concept for a short-duration, micro excavation PCCP strengthening method based on the self-prestressing of the Fe-SMA.

Dynamic interplay of cortisol and BDNF in males under acute and chronic psychosocial stress – A randomized controlled study

The neurotrophic protein brain-derived neurotrophic factor (BDNF) plays a pivotal role in brain function and is affected by acute and chronic stress. We here investigate the patterns of BDNF and cortisol stress reactivity and recovery under the standardized stress protocol of the TSST and the effect of perceived chronic stress on the basal BDNF levels in healthy young men. Twenty-nine lean young men underwent the Trier Social Stress Test (TSST) and a resting condition. Serum BDNF and cortisol were measured before and repeatedly after both conditions. The perception of chronic stress was assessed by the Trier Inventory for Chronic Stress (TICS). After the TSST, there was a significant increase over time for BDNF and cortisol. Stronger increase in cortisol in response to stress was linked to an accelerated BDNF decline after stress. Basal resting levels of BDNF was significantly predicted by chronic stress perception. The increased BDNF level following psychosocial stress suggest a stress-induced neuroprotective mechanism. The presumed interplay between BDNF and the HPA-axis indicates an antagonistic relationship of cortisol on BDNF recovery post-stress. Chronically elevated high cortisol levels, as present in chronic stress, could thereby contribute to reduced neurogenesis, and an increased risk of neurodegenerative conditions in persons suffering from chronic stress.

Sewage sludge ash as filler in asphalt mastic: Low-temperature towards high-temperature performance

The sewage sludge ash (SSA) is characterized as a by-product used in the pavement industry to mitigate the environmental risks, enhance the landfill capacity and conserve the non-renewable resources. This research utilized SSA as a filler substitute in asphalt mastic, and its performance-based properties from low towards high temperatures were evaluated. For this goal, the physical and chemical properties of SSA and rock powder (used as base filler) were determined using BET surface area measurement, X-ray fluorescence, and scanning electron microscopy tests. The performance of base and SSA-modified asphalt mastics in four filler/bitumen weight ratios (0.6, 0.8, 1, and 1.2) was investigated using dynamic shear rheometer, multiple stress creep and recovery, linear amplitude sweep, and bending beam rheometer tests across a wide temperature range. The results indicate that SSA has a higher specific surface area, better bitumen absorption, and lower density compared to the base filler. Additionally, unlike the acidic nature of the base filler, SSA possesses strong basic properties, leading to a stronger chemical bond with bitumen and enhanced resistance to aging, particularly at high temperatures. Moreover, the lower density of SSA escalates the amount of filler per unit volume of the SSA-modified asphalt mastic, leading to the increased stiffness and elasticity. This trend improves resistance to permanent deformation and cracking at medium temperatures, although it has an adverse effect on performance of mastic at low temperatures. Moreover, due to the improved performance of SSA-modified asphalt mastic, this study can contribute to the sustainable development of the pavement industry.

Effect of displacement loading rate on dynamic mechanical characteristics of fault stick-slip under constant normal stiffness conditions

The role of the displacement loading rate in fault activation and evolution is of utmost importance, yet most existing studies have primarily focused on its effect under constant normal load (CNL) conditions. However, in reality, the rock mass surrounding the earthquake source at the deep part of the fault provides normal stiffness conditions. Therefore, the influence of the displacement loading rate on the dynamic mechanical characteristics of fault stick-slip under constant normal stiffness (CNS) conditions remains uncertain. To bridge this research gap, we conducted an experimental investigation on simulated faults in granite under constant normal stiffness (CNS) conditions. Our analysis focused on the influence of the displacement loading rate on the spatial and temporal evolution of local stresses along the fault and the size of the fault nucleation zone. The findings revealed the following: Under the CNS condition, the equivalent shear stress is larger compared to the CNL condition, while the shear stress drop is smaller. The recovery of normal stress under CNS conditions depends more on the displacement loading rate. The nucleation location of the fault is influenced by the normal boundary conditions, with a larger nucleation zone observed in the CNS condition than in the CNL condition. In the early stage of friction, the local stress and stress drop of the fault exhibit a positive correlation with the displacement loading rate, whereas in the later stage, they display a negative correlation. Moreover, at the same location, the order of local stress drop rates for the fault is v3 > v1 > v2, where v1 represents the local normal stress drop rate, v2 represents the local shear stress drop rate and v3 represents the local friction coefficient drop rate. These research results contribute to a further understanding of the deep fault-slip mechanical behavior.