Search Results (273)

To address the challenges of low efficiency and high damage rates in dryland safflower harvesting, a roller-brush type harvesting device was developed. The design was developed following a detailed analysis of the spatial distribution and mechanical characteristics of safflower plants. The pose adjustment process begins with helical grooves clamping and contacting the plant stem. The propulsion action of the helix then forces the stem to undergo a predetermined deflection displacement. The optimal picking pose occurs when the plant’s longitudinal axis is perpendicular to the rotational axis of the picking roller brush. In this position, the picking roller brush shears the filaments at the necking zone through gentle contact with the fruit balls. This mechanism transforms the traditional pull-off separation into a low-damage shear-separation mode. The Box–Behnken test was designed to find the optimal combination of parameters for picking: picking roller brush speed of 282.5 r/min, roller brush spacing of 3.7 mm, and brush bristle diameter of 0.1 mm. Verification tests showed the picking, damage and fruit injury rates were 92.4%, 7.1% and 1.2%, respectively, with standard deviations of 5.42%, 0.51%, and 0.08%. The harvesting efficiency reached 0.053 hm²/h, 8.48 to 12.01 times higher than manual harvesting. Full article

In this study, a highly conductive nickel (Ni) layer was deposited onto a P-type (Zr,Ti)Co(Sn,Sb) half-Heusler (HH) thermoelectric (TE) material using a low-cost electro-brush plating technique. Before depositing Ni on the TE material, the plating process was optimised on a stainless steel (SS) substrate. An optimal medium-rate deposition voltage of 6V was identified on the SS substrate, with the desired thickness, superior mechanical performance, reduced sheet resistance and surface roughness, and enhanced electrical conductivity. The optimised deposition condition was then applied to the P-type (Zr,Ti)Co(Sn,Sb) material, resulting in a Ni layer that significantly enhanced its electrical and thermal stability. After thermal exposure at 500 °C for 10 h, the Ni coating effectively protected the TE surface against oxidation and sublimation, suggesting that the interfacial contact properties of P-type (Zr,Ti)Co(Sn,Sb) TE material can be effectively enhanced by depositing a highly conductive, oxidation-resistant Ni layer using the cost-effective, straightforward electro-brush plating technique. Full article

In chronic obstructive pulmonary disease (COPD), dysregulated calcium homeostasis, oxidative stress, and mucus hypersecretion converge to suppress ciliary beat frequency (CBF), thereby compromising mucociliary clearance (MCC). These mechanisms are subject to pharmacological modulation. Long-acting muscarinic antagonists (LAMAs) exert direct cilia-stimulatory effects and may counteract pathogen-induced mucin overproduction without impairing clearance. Long-acting β₂-agonists (LABAs) enhance ciliary activity through the cAMP–PKA–dynein (cyclic adenosine monophosphate–protein kinase A–dynein) signalling pathway. Inhaled corticosteroids (ICSs), although largely neutral on CBF, provide indirect protection by suppressing IL-13–driven inflammation. Phosphodiesterase (PDE)-4 inhibitors sustain intracellular cAMP and promote ciliary motility, though their clinical use remains limited by adverse effects. Emerging evidence suggests that dual and triple therapies may provide additive or synergistic benefits for preserving mucociliary function. Clinically, ex vivo CBF interpretation may be influenced by ongoing pharmacotherapy and tissue sampling site. Nasal brush samples may predominantly reflect systemic rather than inhaled therapy. Moreover, differences in PDE isoform expression between nasal and bronchial epithelium further complicate direct extrapolation of results. Rigorous patient stratification by treatment regimen is therefore essential to reconcile inconsistencies reported across studies. Ultimately, preservation of MCC in COPD depends on a delicate balance between oxidative stress and pharmacological modulation of ciliary function. Full article

This study investigates the effect of different sintering parameters on the surface roughness and fracture resistance of different CAD/CAM lithium disilicate ceramics before and after thermocycling and simulated toothbrushing. Sixty lithium disilicate ceramic samples were categorized according to ceramic type (AMB: Amber Mill, ECAD: IPS e.max CAD) and level of translucency (LT: low and HT: high) into four groups: AMB_LT, AMB_HT, ECAD_LT and ECAD_HT. Specimens were prepared to 2 mm thickness, crystallized, polished, and subjected to thermocycling to simulate five years of clinical aging. Simulated toothbrushing was performed using a soft-bristled mechanical brushing system under controlled force and strokes. Surface roughness was assessed using a profilometer before and after brushing, and fracture resistance was measured using a universal testing machine. Data were statistically evaluated using paired t-tests, one-way ANOVA with Bonferroni post hoc correction (p ≤ 0.05). LT lithium disilicate specimens exhibited significantly smoother surfaces than high-translucency counterparts. After thermocycling and brushing simulation, all groups showed a statistically significant increase in surface roughness, ranging between 0.239 ± 0.012 μm (AMB_LT) and 0.486 ± 0.014 μm (ECAD_HT). In terms of fracture resistance, the highest values were recorded for ECAD_HT (636 ± 8.29 N), and the lowest in the AMB_HT group (546.3 ± 21.9 N) with significant differences observed between materials and translucency levels. Sintering parameters and artificial aging significantly influenced the surface roughness and fracture resistance of lithium disilicate ceramics. Low-translucency variants demonstrated smoother surfaces and higher strength than high-translucency groups, while all materials exhibited increased roughness after aging. These findings provide guidance for the selection of lithium disilicate ceramics, balancing esthetic and mechanical requirements in anterior and posterior restorations. Full article

Rigid polyurethane foams (RPUFs) are essential polymeric materials, prized for their low density, high mechanical strength, and superior thermal insulation, making them indispensable in construction, refrigeration, and transportation. Despite these advantages, their highly porous, carbon-rich structure renders them intrinsically flammable, promoting rapid flame spread, intense heat release, and the generation of toxic smoke. Traditional strategies to reduce flammability have primarily focused on incorporating additive or reactive flame retardants into the foam matrix, which can effectively suppress combustion but often compromise mechanical integrity, suffer from migration or compatibility issues, and involve complex synthesis routes. Despite recent progress, the long-term stability, scalability, and durability of surface flame-retardant coatings for RPUFs remain underexplored, limiting their practical application in industrial environments. Recent advances have emphasized the development of surface-engineered flame-retardant coatings, including intumescent systems, inorganic–organic hybrids, bio-inspired materials, and nanostructured composites. These coatings form protective interfaces that inhibit ignition, restrict heat and mass transfer, promote char formation, and suppress smoke without altering the intrinsic properties of RPUFs. Emerging deposition methods, such as layer-by-layer assembly, spray coating, ultraviolet (UV) curing, and brush application, enable precise control over thickness, uniformity, and adhesion, enhancing durability and multifunctionality. Integrating bio-based and hybrid approaches further offers environmentally friendly and sustainable solutions. Collectively, these developments demonstrate the potential of surface-engineered coatings to achieve high-efficiency flame retardancy while preserving thermal and mechanical performance, providing a pathway for safe, multifunctional, and industrially viable RPUFs. Full article

Background/Objectives: This in vitro study evaluated the effects of fluoride-free toothpaste, fluoride-containing toothpaste, and a color-correcting gel on the morphology, composition, and mechanical properties of demineralized human enamel. The hypothesis was that fluoride-containing formulations would better preserve enamel integrity compared to non-fluoride and cosmetic products. Methods: Extracted human teeth (n = 3 per group) were demineralized with 36% phosphoric acid and assigned to four groups: E0 (control), E1 (fluoride-free toothpaste), E2 (fluoride-containing toothpaste), and E3 (color-correcting gel). Brushing was performed manually twice daily for 7 days using standardized force. Surface morphology and elemental composition were assessed via SEM–EDX; chemical changes were analyzed by FTIR; mechanical properties were evaluated using the Vickers microhardness test. Results: E1 exhibited the highest microhardness (343.6 HV) but also the highest Ca/P ratio (2.37) and most pronounced surface roughness (p < 0.05 vs. control). E2 showed a balanced Ca/P ratio (2.07), smoother morphology, and detectable fluoride incorporation, despite a lower hardness value (214.5 HV). E3 presented moderate changes in both morphology and composition, with a Ca/P ratio similar to the control (2.06) but surface irregularities visible by SEM. The apparent paradox in E1—high hardness with structural damage—may be due to superficial mineral precipitation without true remineralization. Conclusions: Fluoride-containing toothpaste preserved enamel morphology and chemistry more effectively than the other formulations. Increased hardness in E1 does not necessarily indicate clinical benefit. In vivo studies with longer protocols and pH cycling are needed to confirm these findings. Full article

The working environment of carbon brushes and slip rings in marine applications is extremely harsh, as salt spray deposition alters the contact surface and significantly affects contact resistance. To accurately evaluate the electrical contact performance of carbon brushes and slip rings, it is essential to establish a mathematical model of contact resistance. The main influencing factors include salt spray concentration, sliding speed, contact current, and contact pressure. In this study, the variation trends of dynamic contact resistance with respect to these four factors were investigated through experiments, and the corresponding mechanisms were analyzed. The results show that contact resistance increases consistently with rising salt spray concentration, and the trend continues upward. It also increases gradually with higher sliding speed. Conversely, contact resistance decreases gradually as contact pressure increases. Similarly, an increase in contact current leads to a gradual decrease in contact resistance. Based on the experimental results, a sliding electrical contact resistance (ECR) model incorporating salt spray concentration, sliding speed, contact current, and contact pressure was developed. The findings confirm that the proposed model can be used to predict sliding ECR under various marine working conditions. Full article

Apis cerana cerana is a key social insect, and its ability to recognize chemical signals is crucial for maintaining colony homeostasis and coordinating collective behaviors, such as foraging, nursing, and defense. The legs of insects play a significant role in gustatory perception and proximity olfactory perception. In this study, the leg sensilla of A. c. cerana were observed by scanning electron microscopy (SEM). Two types of sensilla were observed, including sensilla trichodea (Str I, Str II, Str III, Str IV, Str V, and Str VI) and sensilla chaetica (Sch I, Sch II, and Sch III). The two unique structures of the tibial spur (Tsp I, Tsp II) and antennal brush (Abr) are carefully observed. The electrophysiological responses of workers at different ages to diverse chemical compounds were measured via electrolegogram (ELG) recordings on their legs. The results showed that 1-day-old A. c. cerana was more sensitive to nonanal; 10-day-old and 25-day-old A. c. cerana were more sensitive to ocimene. The results of behavioral responses showed that nonanal and ocimene can significantly attract 10-day-old workers of A. c. cerana. This study establishes a foundation for further exploration of the mechanisms by which the legs of A. c. cerana facilitate colony-level communication through chemical signals. It also provides an important theoretical basis for understanding their social organization and information transmission. Full article

Background: Inherited epidermolysis bullosa (EB) includes a group of rare genetic disorders affecting the skin and mucous membranes. These disorders are characterized by extreme fragility and blister formation after minimal or no trauma. Oral and systemic manifestations vary by subtype; the more severe forms often present with extensive intra-oral blistering, scarring, microstomia, vestibular obliteration, ankyloglossia, and—in some cases—oral cancer. This study aims to collect data on oral-health practices and challenges in people with EB to inform preventive strategies and dental care. Methods: An international, structured online questionnaire with 31 items was distributed to individuals with a confirmed diagnosis of EB. The survey explored clinical and oral manifestations, home-care routines (oral hygiene and diet), experiences with dental professionals, and the impact of oral health on quality of life. Results: Eighty-two questionnaires were completed. Dystrophic EB was the most often reported subtype (69.5%). Most respondents (67.1%) experienced recurrent oral blisters and/or erosions. Many reported relying exclusively on soft foods and struggling with mechanical plaque removal because of microstomia and pseudo-syndactyly. Severe oral pain hindered effective brushing in 17% of participants. Hand contractures and microstomia interfered with oral hygiene in 74% and 31% of participants, respectively. Nearly 30% sought dental care only when in pain. Among those who did not attend regular check-ups or hygiene sessions (44.6%), the most cited reason was that dental clinics were inadequately equipped or trained to manage EB. Conclusions: Because dental procedures carry significant risks for patients with EB, preventive care should begin in early childhood. Yet many patients are still insufficiently informed about essential preventive measures and lack access to dental professionals trained in EB management. Full article

Cu–graphite composites are widely used in pantograph sliders and crane brushes. Conventional sintering protocols, however, mandate processing temperatures above 860 °C with prolonged holding periods, which inevitably introduce defects within copper matrices. Drawing inspiration from ultrasonic machining, this study presents an innovative ultrasonic-assisted hot-press sintering (UAHP) technique. Using this novel method, Cu–graphite composites with graphite contents ranging from 0 to 30 vol.% were fabricated at a reduced temperature of 700 °C and a short holding time of 10 min, achieving a ca. 160 °C reduction in densification temperature. Aside from the high densification efficiency, enhanced mechanical properties were also obtained for UAHP-sintered Cu–graphite composites. The Cu–15 vol.% graphite composite exhibited a yield strength of 232 MPa, showing only a 7.2% decrease compared to pure Cu. The friction coefficient decreased with increasing graphite content, reaching a plateau value of 0.140 at 15 vol.% graphite, representing a 77.16% reduction compared to pure Cu. The wear rate initially decreased but gradually increased with the increase in graphite content. The superior tribological performance is attributed to the insitu-formed graphite lubricating film, while the primary wear mechanisms are deemed to be oxidative and abrasive wear. The ultrasonic vibration provides additional sintering driving force and enhances elemental diffusion, establishing UAHP as an innovative technical route for fabricating composites with an optimized microstructure and superior comprehensive properties. Full article

The interaction between tires and snow layer is fundamental for vehicle safety on snowy roads. Due to the instantaneous high torque output characteristics of electric vehicles, they are more prone to slipping when driving in snow, which exacerbates the complexity of tire–snow interaction. In order to construct a more accurate tire–snow interaction model in Northern China, the Bekker formula is introduced to establish the snow pressure–sinkage relationship formula, and the parameters are calibrated by disk experiments. Then the improved tire–snow interaction model is proposed by combining the use of the brush model on the rigid road surface and the dynamic discussion of the tire’s motion behavior on the snow. A coupled finite element (FE) tire model and discrete element (DE) snow terrain model are established, with interactions governed by snow–rubber contact mechanics. The simulation tests the sinking depth of tires on snowy road surface under different slip rates and different loads, as well as the force on tires. The model provides high-precision input to the EV snow traction control algorithm to optimize motor torque distribution to improve energy efficiency. By comparing and analyzing with theoretical values, the traditional empirical model, and the modified physical model, it is finally concluded that the modified model has better reliability than the original model. Compared with the empirical model, the improved model reduces the vertical stress prediction error from 5% to less than 1%, and the motion resistance error from 6% to approximately 2%, providing high-precision input for the snow traction control of electric vehicles. Full article

Obesity is a complex chronic inflammatory condition that results from excess fat accumulation. It increases the risk of developing numerous co-morbidities such as Type 2 diabetes mellitus, cardiovascular disease, hypertension, and stroke. The adipose tissue is itself a vital endocrine organ that secretes numerous adipokines, cytokines, and exosomes, which are collectively known as the adipose-derived secretome (ADS). This ADS has been shown to influence and modulate many physiological processes. During obesity, the composition of ADS is altered, which may contribute to the development of obesity-associated diseases. Type-2 diabetes mellitus is one of the most common complications of obesity due to alterations in glucose homeostasis. Glucose absorption occurs via Na-glucose co-transport via SGLT1 at the brush border membrane (BBM) of small intestinal villus cells. This process of transepithelial glucose uptake is the primary method of glucose absorption from diet. However, how ADS mediates the function of SGLT1 is not yet known. This study aims to determine the mechanism of regulation of SGLT1 by ADS in intestinal epithelial cells. We show that ADS from OZR (but not LZR) stimulates SGLT1 in IEC-18 cells. OZR-ADS treatment diminished Na/K-ATPase activity in IEC-18 cells. Kinetic studies indicated that the mechanism of stimulation for SGLT1 during OZR-ADS treatment was secondary to an increase in the affinity (1/K_m) of the co-transporter for glucose without a change in co-transporter number. Western blot studies revealed that SGLT1 protein expression was unaltered in the two groups, confirming our kinetic studies. Immunoprecipitation demonstrated that an increase in the affinity of the SGLT1 protein was mediated by altered phosphorylation. In conclusion, during obesity, the adipose tissue secretome stimulates SGLT1 in intestinal epithelial cells, leading to an increase in affinity for glucose. The affinity change is due to alterations in SGLT1 phosphorylation. Together, these results may provide important insight into the mechanisms underlying altered glucose homeostasis in obesity and how this may lead to the development of Type 2 diabetes mellitus. Full article

Camellia oleifera is one of the four largest woody oil species in the world, with more than 5 million hectares planted in China alone. Reducing bud damage and improving harvesting net rate and efficiency have become the key challenges to mechanized harvesting of Camellia oleifera fruits. This paper presents a novel comb-spiral impact harvesting device primarily composed of four parts, which are lifting mechanism, picking mechanism, rotating mechanism, and tracked chassis. The workspace of the four-degree-of-freedom lifting mechanism was simulated, and the harvesting reachable area was maximized using MATLAB R2021a software. The picking mechanism, which includes dozens of spirally arranged impact pillars, achieves high harvesting efficiency through impacting, brushing, and dragging, while maintaining a low bud shedding rate. The rotary mechanism provides effective harvesting actions, and the tracked chassis guarantees free movement of the equipment. Simulation experiments and field validation experiments indicate that optimal performance can be achieved when the brushing speed is set to 21.45 r/min, the picking finger speed is set to 341.27 r/min, and the picking device tilt angle is set to 1.0°. With these parameters, the harvesting quantity of Camellia oleifera fruits is 119.75 kg/h, fruit shedding rate 92.30%, and bud shedding rate as low as 9.16%. This new model for fruit shedding and the comb-spiral impact harvesting principle shows promise as a mechanized harvesting solution for nut-like fruits. Full article

Intestinal alkaline phosphatase (IAP) is a brush border enzyme secreted by enterocytes, playing a crucial role in maintaining gut mucosal defense. This study investigated the expression dynamics of IAP in the small intestine of pigs challenged with Escherichia coli (E. coli) K88, compared to healthy controls. Five-week-old pigs (n = 8) were orally administered E. coli K88 at a concentration of 2 × 10⁸ CFU/mL, with a dose of 2 mL per pig at 0 and 24 h. Five days post-challenge, tissue samples from the duodenum, jejunum, and ileum were collected for mucosal morphometric analysis and evaluation of IAP expression via immunohistochemistry, Western blotting, and real-time PCR. The results revealed the presence of IAP on the apical surface of villi throughout the small intestine, along with significantly upregulated IAP expression in E. coli-challenged pigs compared to controls. These findings suggest that Gram-negative bacteria such as E. coli can induce IAP expression, likely through lipopolysaccharide (LPS) stimulation, thereby enhancing its enzymatic activity as part of the intestinal defense mechanism. This study provides insight into the protective role of IAP and highlights its potential as a biomarker for assessing gut health and diagnosing enteric infections in animals. Full article

Bamboo, as a forest product material with good mechanical properties, is considered to be a future timber alternative due to its fast growth and accelerated reforestation potential. The use of OSB panels has significantly increased in the market and OSB has replaced traditional panels. Three different OSB panels coded Type 1, Type 2, and Type 3 were produced using bamboo and some mechanical properties were evaluated. Based on the results, Type 2 OSB panels yielded statistically higher bending strength values than Type 1 and Type 3 panels. There were no significant differences between the Type 1 and the Type 3 OSB panels. When the internal bonding (IB) values of the panels were examined, Type 3 yielded the highest values, followed by Type 2 and Type 1. However, it was observed that these resistance differences were not statistically significant. The only type of failure mode observed was brush-shaped separation from the center of the panels. The load–displacement graph of the OSB bamboo panels under bending load indicated a similar load-displacement curve of typical wood under bending load. Full article