Search Results (96)

Rhamnose is a natural sugar found in glycoproteins and structural polysaccharides of plants, fungi, and bacteria. Its incorporation into glycoconjugates is mediated by rhamnosyltransferases (RHTs), key enzymes for biomolecular stability and function. While rhamnose biosynthesis has been studied in certain fungal genera, the evolutionary history and distribution of RHTs across the fungal kingdom remain largely unknown. In this study, 351 fungal species were found to encode putative RHTs. Phylogenetic and structural analyses revealed conserved patterns and similarities with previously characterized RHTs. Molecular docking predicted a high affinity of these proteins for UDP-L-rhamnose, and in silico mutagenesis identified key residues potentially involved in substrate binding. Carbohydrate profiling confirmed the presence of rhamnose in the cell walls of multiple fungi, including Aspergillus, Madurella, Metarhizium, and Trichoderma species. Enzymatic assays further supported rhamnose transfer activity. These findings provide the first comprehensive in silico characterization of fungal RHTs, uncovering conserved sequence motifs despite overall diversity, which may be linked to functional adaptation in different fungal lineages. Full article

Abrasive waterjet technology is a promising sustainable and green technology for cutting underground structures. Abrasive waterjet usage in demolition promotes sustainable and green construction practices by reduction of noise, dust, secondary waste, and disturbances to the surrounding infrastructure. In this study, a numerical framework based on a coupled Smoothed Particle Hydrodynamics (SPH)–Finite Element Method (FEM) algorithm incorporating the Riedel–Hiermaier–Thoma (RHT) constitutive model is proposed to investigate the damage mechanism of concrete subjected to abrasive waterjet. Numerical simulation results show a stratified damage observation in the concrete, consisting of a crushing zone (plastic damage), crack formation zone (plastic and brittle damage), and crack propagation zone (brittle damage). Furthermore, concrete undergoes plastic failure when the shear stress on an element exceeds 5 MPa. Brittle failure due to tensile stress occurs only when both the maximum principal stress (σ₁) and the minimum principal stress (σ₃) are greater than zero at the same time. The damage degree ($\chi$) of the concrete is observed to increase with jet diameter, concentration of abrasive particles, and velocity of jet. A series of orthogonal tests are performed to analyze the influence of velocity of jet, concentration of abrasive particles, and jet diameter on the damage degree and impact depth (h). The parametric numerical studies indicates that jet diameter has the most significant influence on damage degree, followed by abrasive concentration and jet velocity, respectively, whereas the primary determinant of impact depth is the abrasive concentration followed by jet velocity and jet diameter. Based on the parametric analysis, two optimized abrasive waterjet configurations are proposed: one tailored for rock fragmentation in tunnel boring machine (TBM) operations; and another for cutting reinforced concrete piles in shield tunneling applications. These configurations aim to enhance the efficiency and sustainability of excavation and tunneling processes through improved material removal performance and reduced mechanical wear. Full article

The applicability of RHT in the treatment and supportive care of tumors has been discussed for years in many publications. There are hundreds of articles that have reported on the good acceptance and feasibility of HT, as well as its value in terms of controlling malignant diseases, enhancing response and, in some randomized controlled trials (RCTs), clear improvements in OS. Despite this, HT has never fully been accepted as a standard treatment among radiation and medical oncologists. The increased activity that HT offers in the context of chemotherapy (CHT), radiotherapy (RT), chemoradiotherapy (CRT), and immunotherapy, thus facilitating programmed cell death (PCD), has been documented in many studies. This aspect has been demonstrated in many tumors, including soft tissue sarcoma, cancers of the cervix, esophagus, stomach, colon/rectum, pancreas, breast, head and neck, and prostate, and bone metastases. HT improves cancer cell death through many modalities, targeting both the tumor microenvironment (TME) and the cancer cells directly. Targeted HT increases the temperature of the primary tumor and surrounding tissues to 39–43 °C, causing the tumor cells to become more immune-responsive. HT can also activate the immune response of the TME through inducing heat shock proteins (HSPs), which also promote an immunological response and PCD. HT can oxygenate hypoxic tumors, facilitating RT-induced DNA damage in cancer cells. At present, it seems that the combination of HT and RT, CHT, and immunotherapy might lead to immune enhancement effects in the TME, making cancer cells more responsive to immunotherapies. This narrative review presents the novel aspects of HT reported in recent years. Full article

This study investigates the failure modes and damage extent of reinforced concrete (RC) columns under the combined action of eccentric blast loading and axial compressive loading through experimental tests and numerical simulations. Field blast tests were performed using half-scaled-down models for close-in airburst tests. The effects of charge mass, explosive position, and axial load on the failure modes and damage levels of RC columns under close-range blast loading were investigated. Eight experimental datasets of blast overpressure were obtained, and curve fitting was performed on these data to establish an empirical formula, thereby enhancing the predictive accuracy of blast effect assessment in practical engineering scenarios. The test results indicated that when the explosive position is closer to the column base, the structural failure mode becomes closer to shear failure. To further interpret the experimental data, a detailed finite element model of RC columns was developed. Numerical simulations of RC columns were conducted using the RHT model. The rationality of the model was validated through comparison with experimental data and the SDOF method, with dynamic response analyses performed on cross-sectional dimensions, the longitudinal reinforcement ratio, the scaled distance, the explosion location, and axial compression. An empirical formula was ultimately established to predict the maximum support rotation of RC columns. Studies have shown that when the explosive position is closer to the column base, the structural failure mode approaches shear failure, and axial compression significantly increases the propensity for shear failure. Full article

The electrical conductivity of nanocrystalline CuMnO₂ samples, obtained by microwave-assisted hydrothermal synthesis (MWH), is studied by impedance spectroscopy over a frequency range of 30 Hz to 2 MHz and a temperature range from 30 to 120 °C. Three samples are prepared to start from a mixture of sulphate reactants, at two synthesis temperatures and different reaction times (of applying microwaves): sample S1 at 80 °C for 5 min; sample S2 at 120 °C for 5 min and sample S3 at 120 °C for one hour. The static conductivity values, σ_DC of samples S2 and S3, are approximately equal but larger than those of sample S1. This result suggests that using MWH synthesis at 120 °C, with different reaction times (samples S2 and S3), is sufficient for microwaves to be applied for at least 5 min to obtain samples with similar electrical properties. The experimental data were analysed based on three theoretical models, demonstrating that the most appropriate theoretical model to explain the electrical conduction mechanism in the samples is Mott’s variable range hopping (VRH) model. Using this model, the activation energy of conduction, (E_A,cond), the density of localized states near the Fermi level, N(E_F), the hopping distance, R_h(T), the hopping energy, W_h(T) and the charge carrier mobility (μ) were determined for the first time, for microwave-assisted hydrothermally synthesized crednerite. Additionally, the band gap energy (W_m) and hopping frequency (ω_h) were evaluated at various temperatures T. Understanding the electrical conduction mechanism in the polycrystalline CuMnO₂ materials is important for their use in photo-electrochemical and photocatalytic applications, photovoltaic devices, and, more recently, in environmental protection. Full article

A high-pressure torsion (HPT) with a number of revolutions (n) of up to 10 and an advanced method of accumulative HPT (AccHPT), n = 10 with subsequent post-deformation annealing (PDA) at 500 and 600 °C, were applied to a biodegradable Fe-30Mn-5Si (wt.%) alloy. The effect of HPT, AccHPT and AccHPT with PDA on the microstructure, phase composition, microhardness and electrochemical behavior in Hanks’ solution was studied. HPT with n = 1 and 5 resulted in forming a mixed submicrocrystalline (SMCS) and nanocrystalline (NCS)structure, while HPT, n = 10 and AccHPT, n = 10 resulted in a predominant NCS with grain/subgrain sizes of 15–100 nm and 5–40 nm, respectively. PDA after AccHPT resulted in a mixture of SMCS and NCS. HPT, n = 5, n = 10 and AccHPT, n = 10 led to a transition from a two-phase (γ-austenite and ε-martensite) state after reference quenching, and HPT, n = 1 to a single-phase state (stress-induced and deformed ε-martensite), while the AccHPT, n = 10 with PDA results in a two-phase state of γ-austenite and cooling-induced ε-martensite, similarly to reference heat treatment (RHT). The increase in n resulted in the microhardness increasing up to its maximum after AccHPT, followed by a slight decrease after PDA. HPT and AccHPT led the biodegradation rate to decrease as compared to the initial state. PDA after AccHPT at 500 and 600 °C resulted in a two-phase state corresponding to an elevated biodegradation rate without significant material softening. The observed electrochemical behavior features are explained by changes in a combination of the phase state and the overall level of crystal lattice distortion. Full article

This study examines the behaviour of reinforced concrete (RC) slabs subjected to contact explosions through experimental investigations and numerical simulations. A contact explosive charge field experiment was conducted on a bi-directionally reinforced RC slab to characterise the resulting damage patterns. The experimental findings revealed localised perforation and substantial deformation of the reinforcement bars without bar rupture. A numerical model employing the RHT concrete and Johnson–Cook steel material models was implemented in Ansys Autodyn (v 2023 R2) to replicate the observed responses. Initial verification was carried out against data from the literature, and calibration was performed using the instantaneous geometric strain (IGS) as the erosion parameter. An optimal IGS value of 0.375 was found to reproduce the experimental damage most accurately. Subsequent parametric analyses of the validated models investigated the influence of slab thickness and reinforcement ratios on blast resistance. The results demonstrated that increasing the slab thickness substantially mitigates perforation, while higher reinforcement ratios improve overall structural integrity. This work confirms the reliability of the calibrated numerical models for predicting the response of RC slabs to contact explosions, and it offers valuable insight into the design of blast-resistant structures. Full article

Dentine hypersensitivity (DH) causes pain from exposed dentine, triggered by external stimuli. Limited evidence exists on its impact on quality of life (QoL), the effectiveness of hypersensitivity toothpaste (HT) and the dental behaviors of DH sufferers. This study therefore aimed to generate evidence to address these evidence gaps and validate the existing science behind the effectiveness of HT. An observational retrospective cross-sectional survey was conducted in Indonesia, which included the Dentine Hypersensitivity Experience Questionnaire-15 (DHEQ-15), items related to the perceived effectiveness of HT and self-reported dental health behaviors. A total of 511 respondents completed the survey. The mean (standard deviation) DHEQ score of participants was 82.44 (14.41), showing the substantial impact of DH on QoL. Nearly all HT users (97.7%) reported relief from DH, with additional benefits like long-lasting fresh breath (96.4%) and cleaner teeth (97.1%), with regular HT users experiencing greater benefits such as improvements in DH (R-HT users [4.65 (0.55)] vs. E-HT users [4.46 (0.65)], p < 0.01). Compared to HT users, mainstream toothpaste (MT) users were significantly less likely to brush their teeth at least three times a day (HT users [41.9%], MT users [18.7%], p < 0.05) and to have had a dental check-up within the past year (HT users [82.5%], MT users [47.3%], p < 0.05). This study found that DH significantly impacts QoL, and that HT effectively relieves DH symptoms, particularly for regular users, who also show better dental health behaviors than users of mainstream toothpaste. The preliminary results indicate that educating users about dental products, like hypersensitivity toothpaste, can improve oral health behaviors and outcomes. Full article

To investigate the propagation of stress waves in viscoelastic joints under blasting loads, and their impact on crack propagation and dynamic response in rock masses, a numerical model incorporating intersecting viscoelastic joints was developed using LS-DYNA. This study focuses on the influence of various joint geometric parameters, including thickness and angle, on stress wave propagation and damage patterns in rock. The Riedel–Hiermaier–Thoma (RHT) model was employed to simulate the dynamic behavior of rock, while the Poynting–Thomson model was used to describe the viscoelastic properties of the joint fillings. The simulation results provide detailed insights into the principal stress, displacement, and particle vibration velocity around the joints. Based on the stress wave propagation theory, the velocity transmission coefficients were calculated to quantify the attenuation of stress waves across the joints. The findings demonstrate that viscoelastic joint properties significantly affect the damage patterns in the rock mass. Specifically, the area of the crushed zone and the width of cracks on the blasting side are proportional to joint thickness, while crack propagation at the joint tips is governed by differences in principal stress. Moreover, the propagation of vibration velocity is notably weakened at the second joint, highlighting the critical role played by joint characteristics in stress wave dynamics. These results underscore the complex interaction between joint properties and stress wave behavior in rock masses, providing valuable insights for optimizing blasting designs and improving the safety of underground engineering projects. Full article

To improve the microstructure and mechanical properties of heat-resistant 12Kh1MF steel after long-term operation in the stretched bend zone of the main steam pipeline of a thermal power plant, restorative heat treatment (RHT) was proposed. The RHT mode consisted of two normalization stages (from temperatures of 1100 and 960 °C, respectively) followed by tempering at a temperature of 740 °C. The RHT mode, regulated for steel in the initial state, was applied only after its normalization from a significantly higher temperature (1100 °C). It was shown that the proportion of fine grains in the steel structure increased to 55% over the entire pipe wall thickness after using RHT. At the same time, the proportion of large grains in the restored steel decreased significantly (to 10%), while in exploited steel, their proportion reached almost 50%. The proposed RHT mode increased the hardness, strength, plasticity, and resistance to brittle fracture of the restored steel relative to the corresponding characteristics of the operated steel. The maximum positive effect of the RHT was obtained during impact testing. The fractographic features of the exploited and restored steel were studied on fractures of samples tested by tension. The main fractographic feature of the operated steel was nanosized particles at the bottom of large dimples. These tiny particles were considered to be fragments of large carbides formed due to their final decohesion from the matrix during tensile testing. However, such nanosized particles were not found on the samples’ fracture surfaces in the steel after restorative heat treatment. In addition, the ductile dimples on the fractures of the restored steel were more prominent, which indicated high energy costs for their formation. Thus, all the obtained research results suggest the possibility of using the proposed RHT mode to extend the service life of long-operated critical elements of a thermal power plant’s steam pipelines. Full article

The choice of constitutive model significantly affects the accuracy of concrete perforation simulation. This study analyzes four concrete constitutive models, HJC, RHT, KCC, and TCK, focusing on their strength models, damage evolution, and strain rate effects. Combining the damage pattern and erosion cracks, the effectiveness of the four constitutive models in simulating the penetration of reinforced concrete targets is evaluated using LS-DYNA 11.0. The results indicate that the RHT and TCK models accurately depict the concrete damage and failure modes under the same test conditions. In contrast, the KCC and HJC models demonstrate superior capability in predicting the residual velocity of the projectile. Additionally, this study highlights the significant impact of the erosion parameters on the simulation results. This study offers a valuable reference for the application and parameter set of constitutive models in simulating concrete target perforation. Full article

Rock mass consists of many discontinuities, such as faults, joints, etc., and layered joints are a common kind of rock mass structure. The joints affect the stress wave propagation, and blasting is an economical and efficient rock fragmentation method for rock mass engineering. So, the rock mass fragmentation effect and construction progress are affected by these layered joints. Numerical studies were carried out to analyze the damage evolution process of intact rock and rock mass with layered joints subjected to blasting loads based on the Riedel–Hiermaier–Thoma (RHT) model in LS-DYNA software (smp s R11.0.), and the effects of the location of initiation points and the fracture distribution on dynamic damage evolution of the rock mass were discussed. Bottom initiation tends to direct the blasting energy toward the blasthole mouth, resulting in effective rock fragmentation and ejection. Gradually adjusting the initiation point upward can improve the stress and damage distribution, allowing some of the blasting stress waves to propagate toward the bottom and enhance the fragmentation of the rock at the bottom. The distribution of layered joints exacerbates the damage to the rock mass on the upstream surface, but also acts as a certain shield to the propagation of stress waves, increasing the asymmetry of the damage distribution. It is useful to know the damage mechanism of the rock mass with layered joints to improve the effect of rock mass fragmentation by blasting. These results have very important theoretical significance and application value for the optimization of blasting construction technology. Full article

In the context of crop breeding, plant height (PH) plays a pivotal role in determining straw and grain yield. Although extensive research has explored the genetic control of PH in wheat, there remains an opportunity for further advancements by integrating genomics with growth-related phenomics. Our study utilizes the latest genome-wide association scan (GWAS) techniques to unravel the genetic basis of temporal variation in PH across 179 Bulgarian bread wheat accessions, including landraces, tall historical, and semi-dwarf modern varieties. A GWAS was performed with phenotypic data from three growing seasons, the calculated best linear unbiased estimators, and the leveraging genotypic information from the 25K Infinium iSelect array, using three statistical methods (MLM, FarmCPU, and BLINK). Twenty-five quantitative trait loci (QTL) associated with PH were identified across fourteen chromosomes, encompassing 21 environmentally stable quantitative trait nucleotides (QTNs), and four haplotype blocks. Certain loci (17) on chromosomes 1A, 1B, 1D, 2A, 2D, 3A, 3B, 4A, 5B, 5D, and 6A remain unlinked to any known Rht (Reduced height) genes, QTL, or GWAS loci associated with PH, and represent novel regions of potential breeding significance. Notably, these loci exhibit varying effects on PH, contribute significantly to natural variance, and are expressed during seedling to reproductive stages. The haplotype block on chromosome 6A contains five QTN loci associated with reduced height and two loci promoting height. This configuration suggests a substantial impact on natural variation and holds promise for accurate marker-assisted selection. The potentially novel genomic regions harbor putative candidate gene coding for glutamine synthetase, gibberellin 2-oxidase, auxin response factor, ethylene-responsive transcription factor, and nitric oxide synthase; cell cycle-related genes, encoding cyclin, regulator of chromosome condensation (RCC1) protein, katanin p60 ATPase-containing subunit, and expansins; genes implicated in stem mechanical strength and defense mechanisms, as well as gene regulators such as transcription factors and protein kinases. These findings enrich the pool of semi-dwarfing gene resources, providing the potential to further optimize PH, improve lodging resistance, and achieve higher grain yields in bread wheat. Full article

The solidification processes of two compositions, hypereutectic (21.0 mol% Y₂O₃–79.0 mol% Al₂O₃) and eutectic (18.5 mol% Y₂O₃–81.5 mol% Al₂O₃), were used via the horizontal directional solidification (HDS) method to produce two ingots with dimensions of 317 × 220 × 35 mm and 210 × 180 × 35 mm, respectively. The first ingot was heterogeneous and characterized by a two-layer structure with an expressed horizontal boundary, which is parallel to the solidification direction (an experimental fact observed for the first time), separating eutectic-type ceramics in the upper layer from the lower one containing the YAG dendrites. Considering the heat transfer feature characteristic of the HDS method and its action during the solidification of materials scattering thermal radiation, an explanation of the occurrence of such structure has been proposed. On this basis, the solidification parameters of the second ingot, providing its homogeneous structure, were selected. Characterization of the crystallographic texture and microstructure of both ingots revealed the advantage of the second solidification processing conditions. Full article

This paper aims to investigate the response and fracture of EMT carbon steel round-hole tubes (EMT carbon steel RHTs) under cyclic bending loads. The study considers four different hole orientations (0°, 30°, 60°, and 90°) and five distinct hole diameters (2, 4, 6, 8, and 10 mm). The results reveal that hole orientation and diameter exert a minimal impact on the moment-curvature relationship, leading to the formation of stable loops. The ovalization-curvature graphs demonstrate a trend of asymmetry, serration, and growth with an increasing number of bending cycles. Additionally, larger hole orientations or smaller notch diameters result in reduced ovalization. Furthermore, the double logarithmic coordinates of the controlled curvature–number of cycles required to induce fracture reveal five parallel lines for different hole diameters when the hole orientation is fixed. Finally, in adopting the formulas for smooth tubes and for 6061-T6 aluminum alloy round-hole tubes (6061 aluminum alloy RHTs), this study adjusts the related material parameters. These modifications effectively describe the controlled curvature–number of cycles required to induce fracture for EMT carbon steel RHTs with different hole orientations and diameters under cyclic bending, demonstrating reasonable agreement with the experimental results. Full article