Intermittent mechanical strain

Obesity, a public health challenge, arises from a complex interplay of factors such as dietary habits and genetic predisposition. Alterations in gut microbiota, characterized by an imbalance between Firmicutes and Bacteroidetes, further exacerbate metabolic dysregulation, promoting inflammation and metabolic disturbances. Intermittent fasting (IF) emerges as a promising dietary strategy showing efficacy in weight management and favoring fat utilization. Studies have used mice as animal models to demonstrate the impact of IF on gut microbiota composition, highlighting enhanced metabolism and reduced inflammation...

Hierarchical collagen fibers are the primary source of strength in tendons and ligaments, however these fibers do not regenerate after injury or with repair, resulting in limited treatment options. We previously developed a culture system that guides ACL fibroblasts to produce native-sized fibers and fascicles by 6 weeks. These constructs are promising ligament replacements, but further maturation is needed. Mechanical cues are critical for development in vivo and in engineered tissues; however, the effect on larger fiber and fascicle formation is largely unknown...

Partial cystectomy procedures for urinary bladder-related dysfunction involve long recovery periods, during which urodynamic studies (UDS) intermittently assess lower urinary tract function. However, UDS are not patient-friendly, they exhibit user-to-user variability, and they amount to snapshots in time, limiting the ability to collect continuous, longitudinal data. These procedures also pose the risk of catheter-associated urinary tract infections, which can progress to ascending pyelonephritis due to prolonged lower tract manipulation in high-risk patients...

Osteoarthritis (OA) is a multifactorial disease depending on molecular, genetic, and environmental factors like mechanical strain. Next to the cartilage and the subchondral bone, OA also affects the synovium, which is critically involved in the maintenance of joint homeostasis. As there is a correlation between the extracellular sodium content in the knee joint and OA, this study investigates the impact of sodium on OA-associated processes like inflammation and bone remodeling without and with mechanical loading in synovial fibroblasts...

Materials that combine high stiffness with effective damping are in high demand across various industries. While polymers excel in damping, they often lack stiffness and thermal stability. Conversely, metals and ceramics boast high mechanical and thermal properties but lack damping. This study demonstrates that graphene oxide (GO) and reduced graphene oxide (rGO) films can achieve exceptional viscoelastic properties across a wide temperature range. Furthermore, it explains the damping mechanisms and structural characteristics that influence the unique viscoelastic behavior of GO and rGO films...

Obstructive sleep apnea (OSA) is a common respiratory disorder. Multiple organs, especially the central nervous system (CNS), are damaged, and dysfunctional when intermittent hypoxia (IH) occurs during sleep for a long time. The quality of life of individuals with OSA is significantly impacted by cognitive decline, which also escalates the financial strain on their families. Consequently, the development of novel therapies becomes imperative. IH induces oxidative stress, endoplasmic reticulum stress, iron deposition, and neuroinflammation in neurons...

BACKGROUND: PEEP can potentially modulate inspiratory effort (ΔPes), which is the major determinant of self-inflicted lung injury. RESEARCH QUESTION: Does high PEEP reduce ΔPes in moderate-to-severe ARDS patients on assisted ventilation? STUDY DESIGN AND METHODS: Sixteen patients with PaO2 /FiO2 ≤200 mmHg and ΔPes≥10 cmH2 O underwent a randomized sequence of four ventilator settings: PEEP=5 cmH2 O or PEEP=15 cmH2 O + synchronous (pressure support ventilation, PSV) or asynchronous (pressure-controlled intermittent mandatory ventilation, PC-IMV) inspiratory assistance...

In situ straining tests in high purity α-Fe thin foils at low temperatures1 have demonstrated that crystal line defects, called dislocations, have a jerky type of motion made of intermittent long jumps of several nanometres. This observation conflicts with the standard Peierls mechanism for plastic deformation in body-centred cubic crystals, where the screw dislocation jumps are limited by inter-reticular distances, that is, distances of a few angstroms. Employing atomic-scale simulations, we show that although the short jumps are initially more favourable, their realization requires the propagation of a kinked profile along the dislocation line, which yields coherent atomic vibrations acting as travelling thermal spikes...

The absolute magnitude and rate of arterial desaturation each independently impair whole-body aerobic exercise. This study examined potential mechanisms underlying the rate-dependent relationship. Utilizing an exercise protocol involving unilateral, intermittent, isometric knee extensions (UIIKE), we provided sufficient reperfusion time between contractions to reduce the accumulation of intramuscular metabolic by-products that typically stimulate muscle afferents. The objective was to create a milieu conducive to accentuating any influence of arterial desaturation rate on muscular fatigue...

In this paper, a new technology for on-orbit cold forming of space truss rods is proposed. For the cold roll forming process of asymmetric cross sections of thin strips, the effects of roll gap and roll spacing on the forming of asymmetric cross sections of strips were investigated using ABAQUS simulation + experiments. The study shows the following. When forming a strip with a specific asymmetric cross section, the stresses are mainly concentrated in corners 2/4/6, with the largest strain value in corner 2...

In this study, we aimed to quantify the localised effects of mechanical loading (ML), low (20 μg/kg/day), moderate (40 μg/kg/day) or high (80 μg/kg/day) dosages of parathyroid hormone (PTH), and combined (PTHML) treatments on cortical bone adaptation in healthy 19-week old female C57BL/6 mice. To this end, we utilise a previously reported image analysis algorithm on μCT data of the mouse tibia published by Sugiyama et al. (2008) to measure changes in cortical area, marrow cavity area and local cortical thickness measures (ΔCt...

Renewable energy integration introduces grid instability due to variable and intermittent sources like solar and wind, impacting reliability. This paper provides a thorough discussion of recent advancements and emerging trends in grid-integrated wind energy systems (GIWES) and grid-integrated solar energy systems (GISES). More than 70 research articles have been rigorously assessed and listed the technological and economic challenges. The increase in installations of grid-Integrating systems gives rise to challenges like as grid strain, peak shaving impacts, unpredictability of renewable energy sources (RES), and power quality disturbances...

CONTEXT: Most articles on gut microbiota argue the importance of body composition assessment in patients; however, body composition assessments are fragile (ie, with methodological limitations) in the most recent studies. OBJECTIVE: To present two suggestions for further research using the human body composition assessment. METHODS: The methods used in this study are based on a Pinto et al article published in Nutrition Reviews. DATA EXTRACTION: On the basis of data...

BACKGROUND: High post-surgical failure rates following tendon injury generate high medical costs and poor patient recovery. Cell-based tendon tissue engineering has the potential to produce fully functional replacement tissue and provide new strategies to restore tendon function and healing. In this endeavour, the application of mesenchymal stromal cells (MSCs) encapsulated in biomaterial scaffolds has shown great promise. However, a consensus on optimal promotion of tenogenic differentiation of MSCs has yet to be reached, although growth factors and mechanical cues are generally acknowledged as important factors...

Chronic alcohol consumption can lead to tolerance and escalation of drinking in humans and animals, but mechanisms underlying these changes are not fully characterized. Preclinical models can delineate which mechanisms are involved. The chronic intermittent ethanol exposure (CIE) procedure uses forced exposure to vaporized alcohol that elicits withdrawal and increased responding for alcohol in operant tasks in C57BL/6J inbred mice (Lopez et al, 2008; Kliethermes et al., 2006). Chronic two-bottle choice (2BC) drinking in the same strain elicits abstinent-related depression-like behavior (Stevenson et al...

Background (1): Men's football is a physically demanding contact sport that involves intermittent bouts of sprinting, jogging, walking, jumping and changes of direction. The physical demands of the game vary by level of play (amateur club, sub-elite and open club or international), but injury rates at all levels of the men's football game remain the highest of all sports. Objective: The aim of this study is to conduct a systematic review of data from the epidemiological literature regarding the profile, severity and mechanisms of injuries and the frequency of recurrent injuries in professional and amateur football players...

An abnormal mechanical load is a pivotal inducer of endplate cartilage degeneration, which subsequently promotes intervertebral disc degeneration. Our previous study indicated that intermittent cyclic mechanical compression (ICMC) promotes endplate chondrocyte degeneration, but the mechanism underlying this effect is unclear. In this study, we investigated PTEN-induced kinase 1(PINK1) dependent mitophagy during ICMC-induced endplate chondrocyte degeneration. Furthermore, we determined whether NF-E2-related factor 2 (Nrf2) activation correlated with PINK1-dependent mitophagy regulation and increased oxidation resistance of endplate chondrocytes under ICMC application...

Skeletal muscle regeneration remains a clinical unmet need for volumetric muscle loss and atrophy where muscle function cannot be restored to prior capacity. Current experimental approaches do not account for the complex microenvironmental factors that modulate myogenesis. In this study we developed a biomimetic tissue chip platform to systematically study the combined effects of the extracellular matrix (ECM) microenvironment and mechanical strain on myogenesis of murine myoblasts. Using stretchable tissue chips composed of collagen I (C), fibronectin (F) and laminin (L), as well as their combinations thereof, we tested the addition of mechanical strain regimens on myogenesis at the transcriptomic and translational levels...

Persister cells are drug-tolerant bacteria capable of surviving antibiotic treatment despite the absence of heritable resistance mechanisms. It is generally thought that persister cells survive antibiotic exposure through the implementation of stress responses and/or energy-sparing strategies. Exposure to DNA gyrase-targeting antibiotics could be particularly detrimental for bacteria that carry prophages integrated in their genomes. Gyrase inhibitors are known to induce prophages to switch from their dormant lysogenic state into the lytic cycle, causing the lysis of their bacterial host...

BACKGROUND: Predicting left ventricular recovery (LVR) after acute ST-segment elevation myocardial infarction (STEMI) is of prognostic importance. This study aims to explore the prognostic implications of segmental noninvasive myocardial work (MW) and microvascular perfusion (MVP) after STEMI. METHODS: In this retrospective study, 112 patients with STEMI who underwent primary percutaneous coronary intervention (PCI) and transthoracic echocardiography after PCI were enrolled...