Search Results (21)

Passenger car tires (PCTs) usually consist of a silica/silane-filled Butadiene Rubber (BR) or Solution Styrene Butadiene (SSBR) tread compound. This system is widely used due to improvements observed in rolling resistance (RR) as well as wet grip compared to carbon black-filled compounds. However, the covalent bond that couples silica via silane with the rubber increases the challenge of recycling these products. Furthermore, this strong covalent bond is unable to reform once it is broken, leading to a deterioration in tire properties. This work aims to improve these negative aspects of silica-filled compounds by developing a novel coupling system based on non-covalent interactions, which exhibit a reversible feature. The formation of this new coupling was accomplished by reacting silica with silane and a phenolic resin in order to obtain simultaneous π–π interactions and hydrogen bonding. The reaction was performed using two different silanes (amino and epoxy silane) and an alkyl phenol–formaldehyde resin. The implementation of the new coupling resulted in improved crosslink density, better mechanical performance, superior fatigue behavior, and a similar rolling resistance indicator. Full article

Background/Objectives: Our previous study demonstrated that 3-(4-hydroxy-3-methoxyphenyl)propionic acid (HMPA) administration improved grip strength and reduced blood urea nitrogen levels, but its underlying mechanisms remain unclear. This study aimed to investigate the effects of HMPA on oxidative stress and muscle fiber composition, emphasizing its potential role in modulating redox signaling pathways and influencing muscle development. Methods: Eight-week-old male C57BL/6 mice were orally administered HMPA solution (50 or 500 mg/kg/day) or distilled water (10 mL/kg) for 14 days, and then divided into sedentary and exhaustive exercise groups to evaluate oxidative stress status, myosin heavy chain (MHC) isoform expression, and underlying mechanisms. Results: Both low and high doses of HMPA reduced oxidative stress by decreasing plasma reactive oxygen metabolites. High-dose HMPA reduced plasma nitrite/nitrate levels and enhanced antioxidant capacity post-exercise, accompanied by changes in the mRNA abundance of antioxidant enzymes (e.g., Sod1 and Nqo1) and reductions in the mRNA abundance of nitric oxide synthases (e.g., Nos2 and Nos3) in the soleus. Additionally, high-dose HMPA administration increased the protein expression of MYH4 in the soleus, while low-dose HMPA enhanced the gene expression of Myh4 and Igf1, suggesting that HMPA may promote fast-twitch fiber hypertrophy through the activation of the IGF-1 pathway. Furthermore, low-dose HMPA significantly increased the gene expression of Sirt1 and Nrf1, as well as AMPK phosphorylation post-exercise, suggesting low-dose HMPA may improve mitochondrial biogenesis and exercise adaptation. Conclusions: These findings suggest that HMPA may serve as a dietary supplement to regulate redox balance, enhance antioxidant defenses, and promote the formation of fast-twitch fibers. Full article

Background/Objectives: Carbohydrate and protein restriction are associated with sarcopenia and osteopenia, but the underlying mechanisms remain unclear. We aimed to determine whether mild protein restriction affects muscle and bone function in wild-type (WT) and homozygous carbohydrate response element binding protein (Chrebp) knockout (KO) mice. Methods: Eighteen-week-old male wild-type and homozygous carbohydrate response element binding protein (Chrebp) knockout (KO) mice were fed a control diet (20% protein) or a low-protein diet (15% protein) for 12 weeks. We estimated the muscle weight and limb grip strength as well as the bone mineral density, bone structure, and bone morphometry. Results: Chrebp deletion and a low-protein diet additively decreased body weight (WT control–KO low-protein: mean difference with 95% CI, 8.7 [6.3, 11.0], p < 0.0001) and epidydimal fat weight (1.0 [0.7, 1.2], p < 0.0001). Chrebp deletion and a low-protein diet additively decreased tibialis anterior muscle weight (0.03 [0.01, 0.05], p = 0.002) and limb grip strength (63.9 [37.4, 90.5], p < 0.0001) due to a decrease in insulin/insulin-like growth factor 1 mRNA and an increase in myostatin mRNA. In contrast, Chrebp deletion increased bone mineral density (BMD) (WT control–KO control: –6.1 [–1.0, –2.3], p = 0.0009), stiffness (–21.4 [–38.8, –4.1], p = 0.011), cancellous bone BV/TV (–6.517 [–10.99, –2.040], p = 0.003), and the number of trabeculae (–1.1 [–1.8, –0.5], p = 0.0008). However, in KO mice, protein restriction additively decreased BMD (KO control–KO low-protein: 8.1 [4.3, 11.9], p < 0.0001), bone stiffness (38.0 [21.3, 54.7], p < 0.0001), cancellous bone BV/TV (7.7 [3.3, 12.2], p = 0.006), and the number of trabeculae (1.2 [0.6, 1.9], p = 0.0004). The effects of mild protein restriction on bone formation parameters (osteoid volume (WT control–WT low-protein: –1.7 [–2.7, –0.7], p = 0.001) and the osteoid surface (–11.2 [–20.8, –1.5], p = 0.02) were observed only in wild-type (WT) mice. The levels of bone resorption markers, such as the number of osteoclasts on the surface, the number of osteoclasts, and surface erosion, did not differ between the groups. Conclusions: Both Chrebp deletion and protein restriction led to a decrease in muscle and bone function; therefore, an adequate intake of carbohydrates and proteins is important for maintaining muscle and bone mass and function. Further studies will be needed to elucidate the mechanisms by which ChREBP deletion and a low-protein diet cause osteosarcopenia. Full article

Background: Orthodontic treatment involves moving teeth within the alveolar ridge. Bone remodeling is associated with the activity of osteoblasts and osteoclasts. Procedures such as corticotomy-assisted orthodontic therapy (CAOT) or periodontally accelerated osteogenic orthodontics (PAOO) are intended to reduce bone density and negative stress on the grip side and therefore limit bone resorption during orthodontic movement or add bone substitute material so that the tooth does not cross the vestibular plate. Methods: The study was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The study design was defined in the PICO format—Population (P): patients with full permanent dentition, both adolescents and adults; Intervention (I): orthodontic treatment with fixed appliances using additional supportive treatments such as CAOT or PAOO; Comparison (C): assessment of the impact of additional treatments during orthodontic treatment on the remodeling of the alveolar bone and the condition of the periodontium; Result (O): statistically significant/non-significant differences in the condition of the alveolar bone before and after orthodontic treatment. Search filters include the time of publication of the article, systematic reviews from the last five years, and publications that appeared in English. The information provided in the abstracts of systematic reviews that describe the effects of additional procedures during orthodontic treatment such as CAOT or PAOO on the health of periodontium was analyzed. Articles unrelated to the subject of the planned study and those in which tooth movement acceleration was analyzed were excluded. Results: Eight articles were selected in which a total number of 835 subjects took part. The changes in bone density and effects on periodontium were different after CAOT and PAOO. Conclusions: The validity of CAOT and PAOO procedures remains controversial. Better results are obtained when combined with tissue augmentation or thickening of the gingival phenotype rather than as stand-alone procedures, as their uses to protect periodontal tissues are limited. Full article

Aging leads to tissue and cellular changes, often driven by oxidative stress and inflammation, which contribute to age-related diseases. Our research focuses on harnessing the potent anti-inflammatory and antioxidant properties of Korean Ulmus macrocarpa Hance, a traditional herbal remedy, to address muscle loss and atrophy. We evaluated the effects of Ulmus extract on various parameters in a muscle atrophy model, including weight, exercise performance, grip strength, body composition, muscle mass, and fiber characteristics. Additionally, we conducted Western blot and RT-PCR analyses to examine muscle protein regulation, apoptosis factors, inflammation, and antioxidants. In a dexamethasone-induced muscle atrophy model, Ulmus extract administration promoted genes related to muscle formation while reducing those associated with muscle atrophy. It also mitigated inflammation and boosted muscle antioxidants, indicating a potential improvement in muscle atrophy. These findings highlight the promise of Ulmus extract for developing pharmaceuticals and supplements to combat muscle loss and atrophy, paving the way for clinical applications. Full article

Through an immersive qualitative exploration, we delve into the narratives of East Jerusalem’s Palestinian students as they navigate the complexities of an Israeli teacher training college. Workshops and artistic expression unearth their aspirations, challenges, and coping strategies within a labyrinthine educational landscape. Our findings illuminate their indomitable spirit and unwavering pursuit of dreams despite isolation, discrimination, and the ever-present Israeli–Palestinian conflict. This study contributes to understanding minority students’ experiences in higher education, particularly those in conflict-ridden regions. Drawing upon Resilience Theory, Social Identity Theory, Critical Race Theory, and Cross-Cultural Psychology, we weave a multi-dimensional framework elucidating factors shaping academic achievements, identity formation, and psychological well-being. The fruits of this research empower educators and policymakers to nurture resilience and inclusivity among diverse student populations navigating tempestuous waters. Amplifying Palestinian students’ voices, our work stands as a clarion call for equity and social justice in education, even amidst adversity. We underscore the paramount importance of tailored support systems and interventions, illuminating education’s transformative potential as a catalyst for positive change within communities gripped by conflict. Full article

Handover actions are joint actions between two people in which an object is handed over from a giver to a receiver. This necessitates precise coordination and synchronization of both the reach and grasp kinematics and the scaling of grip forces of the actors during the interaction. For this purpose, a measurement object is presented that records the grip forces of both actors on the instrument and allows synchronous measurement of the kinematic data of both actors and the position and orientation of the instrument in space using an optical motion capture system. Additionally, the object allows one to alter its weight in a covert fashion so that it cannot be anticipated by the actors. It is shown that the four phases of a handover, (1) reach and grasp, (2) object transport, (3) object transfer, and (4) end of handover, can be clearly identified with the described measurement system. This allows the user to measure movement kinematics and grip forces during the individual phases with high precision and therefore systematically investigate handover actions. Using exemplary data, we demonstrate in this study how movement kinematics and grip forces during a handover depend on the characteristics of the object to be measured (i.e., its size or weight). Full article

The latest developments in tissue engineering scaffolds have sparked a growing interest in the creation of controlled 3D cellular structures that emulate the intricate biophysical and biochemical elements found within versatile in vivo microenvironments. The objective of this study was to 3D-print a monolithic silica scaffold specifically designed for the cultivation of neural precursor cells. Initially, a preliminary investigation was conducted to identify the critical parameters pertaining to calcination. This investigation aimed to produce sturdy and uniform scaffolds with a minimal wall-thickness of 0.5 mm in order to mitigate the formation of cracks. Four cubic specimens, with different wall-thicknesses of 0.5, 1, 2, and 4 mm, were 3D-printed and subjected to two distinct calcination profiles. Thermogravimetric analysis was employed to examine the freshly printed material, revealing critical temperatures associated with increased mass loss. Isothermal steps were subsequently introduced to facilitate controlled phase transitions and reduce crack formation even at the minimum wall thickness of 0.5 mm. The optimized structure stability was obtained for the slow calcination profile (160 min) then the fast calcination profile (60 min) for temperatures up to 900 °C. In situ X-ray diffraction analysis was also employed to assess the crystal phases of the silicate based material throughout various temperature profiles up to 1200 °C, while scanning electron microscopy was utilized to observe micro-scale crack formation. Then, ceramic scaffolds were 3D-printed, adopting a hexagonal and spherical channel structures with channel opening of 2 mm, and subsequently calcined using the optimized slow profile. Finally, the scaffolds were evaluated in terms of biocompatibility, cell proliferation, and differentiation using neural precursor cells (NPCs). These experiments indicated proliferation of NPCs (for 13 days) and differentiation into neurons which remained viable (up to 50 days in culture). In parallel, functionality was verified by expression of pre- (SYN1) and post-synaptic (GRIP1) markers, suggesting that 3D-printed scaffolds are a promising system for biotechnological applications using NPCs. Full article

Bayberry is known to be a rich source of natural flavonoids and has been reported to have various health-promoting abilities. However, its function on regulating skeletal muscle fiber type remains unclear. This study examined whether bayberry extract affects skeletal muscle fiber type by promoting fast myofiber formation, as well as the potential molecular mechanism. After eight weeks, the “Biqi” bayberry extract (BBE) groups mice displayed markedly enhanced grip strength and improved metabolic rate compared to the control group mice. BBE also significantly increased myofibers size, LDH activity, MyHC-IIb (fast-twitch mRNA) expression, and the percentage of fast-twitch myofibers, while decreasing SDH activity, MyHC-I (slow-twitch mRNA) expression, and slow-twitch myofibers percentage in the skeletal muscle of the mice. The effect of BBE on regulating skeletal muscle fiber type remodeling is likely attributed to its activation of the Akt-FoxO1 pathway. Our findings indicated that BBE can effectively regulate the expression and proportion of fast-twitch fibers, making it a potential therapy for improving glucose homeostasis of skeletal muscle. Full article

Duckweeds (Lemnaceae) are small, simply constructed aquatic higher plants that grow on or just below the surface of quiet waters. They consist primarily of leaf-like assimilatory organs, or fronds, that reproduce mainly by vegetative replication. Despite their diminutive size and inornate habit, duckweeds have been able to colonize and maintain themselves in almost all of the world’s climate zones. They are thereby subject to multiple adverse influences during the growing season, such as high temperatures, extremes of light intensity and pH, nutrient shortage, damage by microorganisms and herbivores, the presence of harmful substances in the water, and competition from other aquatic plants, and they must also be able to withstand winter cold and drought that can be lethal to the fronds. This review discusses the means by which duckweeds come to grips with these adverse influences to ensure their survival. Important duckweed attributes in this regard are a pronounced potential for rapid growth and frond replication, a juvenile developmental status facilitating adventitious organ formation, and clonal diversity. Duckweeds have specific features at their disposal for coping with particular environmental difficulties and can also cooperate with other organisms of their surroundings to improve their survival chances. Full article

Additive technologies have been widely adopted in various industries. The choice of additive technology and material directly affects the functionality of the manufactured components. The development of materials with better mechanical properties has led to a growing interest in replacing traditional metal components with those manufactured using additive technologies. The application of Onyx as a material comes into consideration, which contains short carbon fibers to increase the mechanical properties. This study aims to experimentally verify the viability of substituting metal gripping elements with nylon and composite materials. The design of the jaws was customized to meet the requirements of a three-jaw chuck of a CNC machining center. The evaluation process involved monitoring the functionality and deformation effects on the clamped PTFE polymer material. When the metal jaws were applied, significant deformation of the clamped material occurred, which varied with the clamping pressure. This deformation was evidenced by the formation of spreading cracks on the clamped material and permanent shape changes in the tested material. Conversely, nylon and composite jaws manufactured using additive technology demonstrated functionality across all tested clamping pressures, without causing permanent deformation of the clamped material, unlike the traditional metal jaws. The results of this study confirm the applicability of the Onyx material and provide practical evidence of the potential for reducing deformation caused by clamping mechanisms. Full article

The application of additive technologies, namely, fused deposition modeling, is a new reality for prototyping gripping devices of industrial robots. However, during 3D printing of holes and nozzle elements, difficulties arise with reducing their diameter. Therefore, this article conducts a comprehensive study of the Bernoulli gripping device prototype with a cylindrical nozzle, manufactured by fused deposition modeling 3D printing. The three main reasons for reducing the diameter of the gripper nozzle after printing were due to the poor-quality model, excessive extrusion of plastic in the middle of the arc printing path, and linear shrinkage of printing material after cooling. The proposed methodology consisted of determining the three coefficients that allowed the determination of the diameter of the designed nozzle. The use of air pressure distributions on the surface of the manipulation object, and lifting forces of gripping devices with different 3D printing layer heights were found. It was experimentally determined that as the height of the printing layer increased, the lifting force decreased. This was due to the formation of swirls due to the increased roughness of the grip surface. It was proven that as the height between the manipulation object and the grip increased, the effect of surface roughness on the lifting force decreased, resulting in an increase in the lifting force. Determination of the rational operating parameters of gripping devices manufactured by 3D printing from the point of view of maximum lifting force, were determined. Full article

Parkinson’s disease (PD) is characterised by dopaminergic neuronal loss in the brain area. PD is a complex disease that deteriorates patients’ motor and non-motor functions. In experimental animals, the neurotoxin 6-OHDA induces neuropathological, behavioural, neurochemical and mitochondrial abnormalities and the formation of free radicals, which is related to Parkinson-like symptoms after inter-striatal 6-OHDA injection. Pathological manifestations of PD disrupt the cAMP/ATP-mediated activity of the transcription factor CREB, resulting in Parkinson’s-like symptoms. Forskolin (FSK) is a direct AC/cAMP/CREB activator isolated from Coleus forskohlii with various neuroprotective properties. FSK has already been proven in our laboratory to directly activate the enzyme adenylcyclase (AC) and reverse the neurodegeneration associated with the progression of Autism, Multiple Sclerosis, ALS, and Huntington’s disease. Several behavioural paradigms were used to confirm the post-lesion effects, including the rotarod, open field, grip strength, narrow beam walk (NBW) and Morris water maze (MWM) tasks. Our results were supported by examining brain cellular, molecular, mitochondrial and histopathological alterations. The FSK treatment (15, 30 and 45 mg/kg, orally) was found to be effective in restoring behavioural and neurochemical defects in a 6-OHDA-induced experimental rat model of PD. As a result, the current study successfully contributes to the investigation of FSK’s neuroprotective role in PD prevention via the activation of the AC/cAMP/PKA-driven CREB pathway and the restoration of mitochondrial ETC-complex enzymes. Full article

As a neurodegenerative disease, Alzheimer’s disease (AD) seriously affects the health of older people. Changes in synapses occur first over the course of the disease, perhaps even before the formation of Aβ plaques. Histone deacetylase (HDAC) mediates the damage of Aβ oligomers to dendritic spines. Therefore, we examined the relationship between HDAC activity and synaptic defects using an HDAC inhibitor (HDACI), BG45, in the human neuroblastoma SH-SY5Y cell line with stable overexpression of Swedish mutant APP (APPsw) and in APP/PS1 transgenic mice during this study. The cells were treated with 15 μM BG45 and the APP/PS1 mice were treated with 30 mg/kg BG45. We detected the levels of synapse-related proteins, HDACs, tau phosphorylation, and amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors using Western blotting and immunohistochemistry. We also measured the expression of cytoskeletal proteins in the cell model. The mRNA levels of the glutamate ion receptor alginate subunit 2 (GRIK2), sodium voltage-gated channel beta subunit (SCN3B), synaptophysin (SYP), Grm2 (the gene encoding glutamate receptor subunit 2 (GluR2)), Grid2IP, glutamate receptor interacting protein 1 (GRIP1), and GRIP2 were detected to explore the effects of the HDACI on regulating the expression of synaptic proteins and AMPA receptors. According to our studies, the expressions of HDAC1, HDAC2, and HDAC3 were increased, which were accompanied by the downregulation of the synapse-related proteins SYP, postsynaptic dendritic protein (PSD-95), and spinophilin as early as 24 h after transfection with the APPsw gene. BG45 upregulated the expression of synapse-related proteins and repaired cytoskeletal damage. In vivo, BG45 alleviated the apoptosis-mediated loss of hippocampal neurons, upregulated synapse-related proteins, reduced Aβ deposition and phosphorylation of tau, and increased the levels of the synapse-related genes GRIK2, SCN3B, SYP, Grm2, and Grid2IP. BG45 increased the expression of the AMPA receptor subunits GluA1, GluA2, and GluA3 on APPsw-transfected cells and increased GRIP1 and GRIP2 expression and AMPA receptor phosphorylation in vivo. Based on these results, HDACs are involved in the early process of synaptic defects in AD models, and BG45 may rescue synaptic damage and the loss of hippocampal neurons by specifically inhibiting HDAC1, HDAC2, and HDAC3, thereby modulating AMPA receptor transduction, increasing synapse-related gene expression, and finally enhancing the function of excitatory synapses. BG45 may be considered a potential drug for the treatment of early AD in further studies. Full article

Drug-resistance-associated mutation in essential proteins of the viral life cycle is a major concern in anti-retroviral therapy. M46I, a non-active site mutation in HIV-1 protease has been clinically associated with saquinavir resistance in HIV patients. A 100 ns molecular dynamics (MD) simulation and MM-PBSA calculations were performed to study the molecular mechanism of M46I-mutation-based saquinavir resistance. In order to acquire deeper insight into the drug-resistance mechanism, the flap curling, closed/semi-open/open conformations, and active site compactness were studied. The M46I mutation significantly affects the energetics and conformational stability of HIV-1 protease in terms of RMSD, RMSF, Rg, SASA, and hydrogen formation potential. This mutation significantly decreased van der Waals interaction and binding free energy (∆G) in the M46I–saquinavir complex and induced inward flap curling and a wider opening of the flaps for most of the MD simulation period. The predominant open conformation was reduced, but inward flap curling/active site compactness was increased in the presence of saquinavir in M46I HIV-1 protease. In conclusion, the M46I mutation induced structural dynamics changes that weaken the protease grip on saquinavir without distorting the active site of the protein. The produced information may be utilized for the discovery of inhibitor(s) against drug-resistant HIV-1 protease. Full article