Mixed Mode Research Articles

Continuing medical education for attending physicians in anesthesia: Feasibility of an innovative blended learning approach.

Continuing medical education plays a pivotal role in fostering and upholding the standard of excellence in medicine. Both SPOC (small private online course) and BOPPPS (bridge-in, learning objective, pretest, participatory learning, posttest, and summary) methodologies are rooted in the same educational and learning theories, emphasizing active student engagement, interaction, and feedback. Using ultrasound-guided spinal anesthesia as an exemplar, we aimed to investigate the feasibility of blended teaching (combination of BOPPPS and SPOC) for anesthesiology clinicians and explore trainees' and trainers' perspectives towards the innovative method. Twenty-seven attending anesthesiologists were randomly divided into experimental group (n = 14, blended teaching method) and control group (n = 13, traditional teaching method). The questionnaire was administered before and a week post-training. Their operative skills (measured by operation time) were assessed. The students' cognitive evaluation of the blended teaching mode was conducted in the experimental group. The experimental group demonstrated notably higher theoretical scores compared to the control group [(46.42 ± 5.345) vs (41.92 ± 5.219), t = 2.213, P < .05]. The operation time in the experimental group was significantly shorter than that in the control group [(84.79 ± 28.450) seconds vs (114.23 ± 35.607) seconds, t = -2.383, P < .05]. Most participants preferred blended learning as it was more effective than traditional learning. Suggestions for enhancement included enhanced online interactivity with trainers and the inclusion of case analysis. Integration of blended teaching incorporating BOPPPS and SPOC methodologies holds promise for enhancing the efficiency of skill training among anesthesiologists. Blended learning may become a viable and well-received option among anesthesia clinicians in China.

Unveiling the tyrosinase inhibitory potential of phenolics from Centaurium spicatum: Bridging in silico and in vitro perspectives

Phenolics, abundant in plants, constitute a significant portion of phytoconstituents consumed in the human diet. The phytochemical screening of the aerial parts of Centaurium spicatum led to the isolation of five phenolics. The anti-tyrosinase activities of the isolated compounds were assessed through a combination of in vitro experiments and multiple in silico approaches. Docking and molecular dynamics (MD) simulation techniques were utilized to figure out the binding interactions of the isolated phytochemicals with tyrosinase. The findings from molecular docking analysis revealed that the isolated phenolics were able to bind effectively to tyrosinase and potentially inhibit substrate binding, consequently diminishing the catalytic activity of tyrosinase. Among isolated compounds, cichoric acid displayed the lowest binding energy and the highest extent of polar interactions with the target enzyme. Analysis of MD simulation trajectories indicated that equilibrium was reached within 30 ns for all complexes of tyrosinase with the isolated phenolics. Among the five ligands studied, cichoric acid exhibited the lowest interaction energies, rendering its complex with tyrosinase the most stable. Considering these collective findings, cichoric acid emerges as a promising candidate for the design and development of a potential tyrosinase inhibitor. Furthermore, the in vitro anti-tyrosinase activity assay unveiled significant variations among the isolated compounds. Notably, cichoric acid exhibited the most potent inhibitory effect, as evidenced by the lowest IC50 value (7.92 ± 1.32 µg/ml), followed by isorhamnetin and gentiopicrin. In contrast, sinapic acid demonstrated the least inhibitory activity against tyrosinase, with the highest IC50 value. Moreover, cichoric acid exhibited a mixed inhibition mode against the hydrolysis of l-DOPA catalyzed by tyrosinase, with Ki value of 1.64. Remarkably, these experimental findings align well with the outcomes of docking and MD simulations, underscoring the consistency and reliability of our computational predictions with the actual inhibitory potential observed in vitro.

Inertial Waves in a Nonlinear Simulation of the Sun's Convection Zone and Radiative Interior

Recent observations of Rossby waves and other more exotic forms of inertial oscillations in the Sun’s convection zone have kindled the hope that such waves might be used as a seismic probe of the Sun's interior. Here, we present a 3D numerical simulation in spherical geometry that models the Sun’s convection zone and upper radiative interior. This model features a wide variety of inertial oscillations, including both sectoral and tesseral equatorial Rossby waves, retrograde mixed inertial modes, prograde thermal Rossby waves, the recently observed high-frequency retrograde (HFR) vorticity modes, and what may be latitudinal overtones of these HFR modes. With this model, we demonstrate that sectoral and tesseral Rossby waves are ubiquitous within the radiative interior as well as within the convection zone. We suggest that there are two different Rossby-wave families in this simulation that live in different wave cavities: one in the radiative interior and one in the convection zone. Finally, we suggest that many of the retrograde inertial waves that appear in the convection zone, including the HFR modes, are in fact all related, being latitudinal overtones that are mixed modes with the prograde thermal Rossby waves.

An eco-extraction protocol based on blended mode microwave hydrodiffusion and gravity (MHG) principle for floral biomass valorisation through simultaneous recovery of volatile and non-volatile principles: the case of Tagetes erecta

An eco-extraction protocol based on blended mode microwave hydrodiffusion and gravity (MHG) principle for floral biomass valorisation through simultaneous recovery of volatile and non-volatile principles: the case of Tagetes erecta

Evolution of microstructure and mechanical properties of aluminum matrix composites reinforced with dual-phase heterostructures

The trade-off between strength and plasticity has long been challenging in particle-reinforced aluminum matrix composites (PRAMCs). This study proposes an innovative approach for preparing aluminum matrix composites (AMCs) using a dual-phase hybrid of FeCoNiCrMn high entropy alloy (HEA) and multiscale aluminum oxide (Al2O3) particles. The microstructure evolution and strengthening mechanisms were evaluated through scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The results demonstrated that the dual-phase particle strengthening resulted from the alternating distribution and synergistic action of HEA and Al2O3 particles within the matrix, forming a continuous strain buffer with a strength gradient. Notably, introducing HEA and nano-Al2O3 led to a higher density of dislocations. Additionally, EBSD analysis revealed a uniform strain distribution within the AMCs, with a significant concentration of kernel average misorientation (KAM) near the grain boundaries (GBs). In terms of micromechanical properties, the micro-zones of heterogeneous phases exhibit exceptionally high elastic modulus and nanohardness. In terms of macroscopic mechanical properties, the material exhibited impressive ultimate compressive strength and compression ratio values of 447.9 MPa and 37.9 %, respectively. These results represented a remarkable enhancement of 72.1 % and 6.6 % compared to the single FeCoNiCrMn HEA strengthening. Moreover, when applying the HEA + nano-Al2O3 blending mode, the ultimate compressive strength further increased to 506.7 MPa, representing an astonishing boost of 94.7 %. This significant strength improvement can be attributed to effective interfacial bonding, grain refinement, and a high dislocation density resulting from both HEA and Al2O3 particles.

Blended learning as a means of improvement of Business English proficiency

The paper introduces the findings and results of a quantitative and qualitative study of the use of online technologies and platforms during blended learning classes and their impact on students' performance in learning Business English at Armenian State University of Economics. The current resulted in the fact that we arrived at the conclusion that blended learning has its advantages and disadvantages, but the advantages are prevalent in this case. By the means of blended learning in teaching Business English, lecturers improve their skills in utilizing online websites, online learning resources and tools, online platforms (especially www.nearpod.com) to develop and design effective lessons, to increase student productivity and performance, by developing specially designed lessons, tests, as well as online games in the form of tests. All online tools, resources and platforms that are investigated and introduced in the paper were used on an ongoing basis during our teaching practices and justified the hypothesis that was aimed to be tested and justified. As a result of the study, through the utilization of online platforms and resources and their implementation in blended learning settings as well as be the means of diagnostic, progress and final tests, we have identified that the knowledge has doubled among students studying the subject (in our case, Business English) in a blended mode of learning.

The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study.

This study aimed to compare the bond strength of AH Plus sealer to root canal dentin when used with or without various antibiotics including amoxicillin, clindamycin, and triple antibiotic mixture (TAM). A total of 80 single-rooted extracted human teeth were instrumented and obturated with gutta-percha and four different sealer-antibiotic combinations (n = 20). Group I: AH Plus without any antibiotics, Group II: AH Plus with amoxicillin, Group III: AH Plus with clindamycin, and Group IV: AH Plus with TAM. After seven days, the roots were sectioned perpendicular to their long axis and 1 mm thick slices were obtained from the midroots. The specimens were subjected to a push-out bond strength test and failure modes were also evaluated. Data was analyzed using Kruskal-Wallis and Dunn's post hoc tests. Group IV had significantly higher bond strength compared to other groups (p ≤ 0.05). No significant differences were found between other groups. While the sealer-antibiotic groups predominantly showed cohesive failure modes, the control group displayed both cohesive and mixed failure modes. Within the limitations of this study, the addition of TAM increased the push-out bond strength of AH Plus. Amoxicillin, clindamycin, or TAM can be added to AH Plus for increased antibacterial efficacy without concern about their effects on the bond strength of the sealer. How to cite this article: Adl A, Shojaei NS, Ranjbar N. The Effect of Adding Various Antibiotics on the Push-out Bond Strength of a Resin-based Sealer: An In Vitro Study. J Contemp Dent Pract 2024;25(3):231-235.

Understanding the influence of environmental conditions on the low cycle fatigue behaviour of high strength low alloy (HSLA) steel under air and corrosive (3.5% NaCl) conditions

Offshore structures which are made up of high-strength low alloy (HSLA) steel experience fatigue load due to sea waves and corrosion. In the present work, the influence of environmental conditions (air and 3.5 % NaCl solution) on the strain-controlled fatigue life of High Strength Low Alloy (HSLA) steel has been determined. Low cycle fatigue experiments were conducted on HSLA steel specimens of 12 mm diameter which were prepared parallel to the rolling direction. The strain amplitude was varied in the range of 0.4 to 0.7 % for a constant test frequency of 0.3 Hz. For all the total strain amplitudes (Δεt/2), a significant reduction in fatigue life was observed while testing the specimens under the presence of 3.5 % NaCl solution compared to the air environment. Microscopic investigation indicates that rigorous grain boundary oxidation has happened, and it has created the grain boundary cracking and several sites for fatigue crack initiation and propagation. The presence of corrosive compounds (Fe2O3, FeOOH) was also confirmed by the X-ray diffraction patterns. In addition, mixed modes (transannular and intergranular) of fractures were observed due to the presence of 3.5 % NaCl solution.

Learning paragraph writing electronically: An insight into impact of blended learning strategies on ESL learners in Pakistan

A comprehensive teaching plan, mindful practices and effective use of technology can boost the writing skills of Second Language Learners by improving spontaneity, naturalness, and accuracy. A vibrant learning community, strongly connected through on-site and online mediums, is ideal for enhancing the skills of foreign language students. This research focuses on enhancing students’ paragraph writing skills by blending traditional and modern technology tools in a hybrid form of instruction. The participants of the study were divided into experimental and control groups; they were students of English as a Second Language (ESL) learners at a private university in Pakistan. After the pre-test, both groups were taught the same curriculum through different pedagogy for six weeks. The experimental group received instructions in a blended mode with the help of technology tools. The results were analyzed at pre and post-research levels by applying a t-test. The results showed a noticeable improvement in the skills of the experimental group. The same course taught with a traditional pedagogy could not produce the desirable results in the control group. The analysis includes vocabulary, reflective thinking, adherence to language mechanics, and grammar to boost the students’ creative writing ability for paragraph composition.

Multifractal characteristics of soil particle size distribution of abandoned homestead reclamation under different forest management modes

In this study, fast-growing poplar reclaimed from abandoned homestead in Xixian New District, Xi’an City, Shaanxi Province, was used as the research object to explore the multi-fractal characteristics of soil particle size distribution under different management modes of abandoned land (control), irrigation, fertilizer irrigation and mixed fertilizer irrigation. The results showed that the mean values of soil clay, silt and sand in abandoned land were 14.58%, 81.21% and 4.22% respectively, 14.08%, 79.92% and 5.99% under irrigation, 15.17%, 81.19% and 3.64% under fertilizer irrigation, and 16.75%, 80.20% and 3.05% in mixed fertilizer treatment. From 40 cm, with increasing soil depth, soil clay particles increase under irrigation, fertilizer irrigation, and mixed fertilizer irrigation modes. The single fractal dimension of soil particle size distribution (D) in each treatment ranges from 2.721 to 2.808. At 60–100 cm, D shows fertilizer irrigation > mixed fertilizer irrigation > irrigation > abandoned land, indicating that fertilization and irrigation can increase the fine-grained matter of deep soil particles and reduce soil roughness. Compared with abandoned land, under irrigation, fertilizer irrigation and mixed fertilizer modes the capacity dimension (D0), entropy dimension (D1), correlation dimension(D2), shape characteristics of the multifractal spectrum (Δf) and overall inhomogeneity of the soil particle size distribution (D0–D10) indicate an uneven distribution of soil particle size; fractal structure characteristics of soil (D−10–D0) indicate a simplified soil structure, and degree of dispersion of soil particle size distribution (D1/D0) indicates that soil particle size is distributed in dense areas. Pearson correlation analysis showed that D was significantly correlated with clay, sand, D0–D10, soil organic matter (SOM) and soil available phosphorus (SAP) (P < 0.05). Stepwise regression analysis showed that clay was the main controlling factor of D and D0–D10 changes. The research results can provide some potential indicators for the quality evaluation of abandoned homestead reclamation.

Asteroseismology of three evolved stars in M67: testing systematic biases in seismic masses and ages

ABSTRACT Asteroseismology can precisely characterize stars, but the accuracy of seismic inference is still an open question. In this work, we use three evolved stars, including one late subgiant (EPIC 211411922) and two young red giants (EPIC 211409560 and EPIC 211416749) in the open cluster M67 to validate seismic inferences of stellar mass and age. We start by measuring oscillation mode frequencies and identifying acoustic and mixed modes in all three stars. We then fit the stars to determine their masses and ages with a detailed modelling approach. Our age estimates for all stars agree well with the literature consensus age range of M67 (3.0–5.0 Gyr). Mass estimates for EPIC 211411922 and EPIC 211409560 are sensible because they are slightly higher than the typical turn-off mass of the cluster. The inferred mass for EPIC 211416749 is underestimated by 5–10 per cent compared with the turn-off mass, but this could be caused by poor data quality. Our results indicate that the detailed modelling can determine sensible masses and ages for evolved stars near the base of the red giant branch.

The Future Higher Education in Albania in the Digital Era–Challenges and Opportunities

Over the last decade, Albania made genuine attempts to adopt its education system after the European model considering the implementation and integration of ICT as a functional skill of digital literacy to face, among others, the challenges of current globalization. But the Covid-19 crisis evidenced that such a revolutionizing of the education system was applied to ICT incorporation and implementation into a curriculum of merely conventionally-based teaching and learning process. Precisely, the research question addresses the evolution of the higher education in Albania against the backdrop of lessons learned from the pandemic crisis in view of an effective and qualitative education system while making the most of technological and digitalized tools. The study is based on a qualitative analysis offering a theoretical approach of primary and secondary sources and continues with the empirical research conducted in 2023 - a survey questionnaire regarding students’ perceptions of the blended mode of teaching and learning process and also a comparative assessment with the one conducted in 2020 regarding their attitudes of online delivery. Hence, by considering the analysis in two quite differing contexts, the aim is to explore how have students’ outlooks changed regarding the mode of delivery of the teaching and learning process since the pandemic period to date. The study also includes in-field expertise acquired to that aim from the University of Münster (Germany) in the framework of the RESILIENCE Project.

Universal slope-based J-integral methods for characterization of the mode I, mode II and mixed mode I/II fracture behaviour of adhesively bonded interfaces

Universal slope-based J-integral methods have been developed for the determination of the energy release rate for adhesively bonded joints under mode I, mode II and mixed-mode (I/II) loading conditions. The individual J components corresponding to the mode I and mode II loading were separated based on the J-integral decomposition theory. The proposed methods use the slopes of the substrates at various locations to characterize the energy release rate and thus avoid the measurement of crack lengths, which are especially suitable for characterizing the tough interfaces associated with large fracture process zones ahead of crack tips. Under linear elastic deformation, the slope-based J equations were found to be equivalent to classical G equations based on linear elastic fracture mechanics (LEFM). Both experimental and numerical testing of adhesively bonded joints were undertaken to validate the slope-based J equations. The universal slope-based J-integral methods provide a reliable alternative to the measurement of G for adhesive joints or laminated composites undergoing nonlinear or inelastic deformations where conventional LEFM is not valid. It is shown that LEFM, even when coupled with an effective crack length approach, can be inaccurate when damage occurs in a test specimen away from the fracture process zone, as was seen here in mode II. Slope-based J equations can avoid these inaccuracies with a careful selection of contour paths. Slope based methods are therefore strong candidates for selection in future test standards for mode II fracture characterisation of structural adhesive joints.

Crashworthiness Performance of Circular Hybrid Crash Box Due to Axial Load

In the previous study, hybrid crash box combines low-density and high strength of composite materials with aluminum materials had been developed. In this study, circular hybrid crash box with friction model is investigated. Crash box design is modelled by using computer simulation with ANSYS workbench. Composite carbon toray T300 – epoxy resin (CCE) and metal aluminum alloy 6063 (AA6063) is used as hybrid crash box material. Axial loading with a speed of 10 m/s is applied to circular hybrid crash box model by using impactor with mass of 100 kg. The orientation angle of composite lay-up and hybrid material configuration with two models of friction was running as 16 models. Energy absorption and deformation pattern were observed to determine crashworthiness performance. Based on the results, it can be denoted that the Al-Ko45 with friction model of 0.68 shows largest energy absorption of 7.53 kJ with specific energy absorption of 32.552 kJ/kg. The deformation pattern produces mixed mode with progressive crushing folding that can enhance energy absorption.

Study of fatigue crack propagation on modified CT specimens under variable amplitude loadings using machine learning

This study focuses on predicting fatigue crack paths and fatigue life in modified compact tension specimens, under mixed mode and variable amplitude loading conditions, using Machine Learning techniques. Mixed-mode conditions were induced by using specimens that incorporated holes with different radii and center coordinates. Initially, multiple Finite Element Method (FEM) simulations were conducted to determine the fatigue crack path for different configurations. Subsequently, several configurations were selected for experimental fatigue testing, in which the fatigue crack path was monitored and recorded. The final phase of the study involved Machine Learning (ML) techniques, specifically Artificial Neural Networks (ANN) and k-Nearest Neighbors (kNN), to predict fatigue crack propagation. The models were trained using different numerical and experimental data. Predicted results were then compared with experimentally tested data, and the behavior and accuracy of the models were evaluated. Overall, the implemented models demonstrated the ability to predict fatigue crack path with average deviations (ANN – 1.19 mm; kNN – 1.10 mm) closely resembling results obtained through Finite Element simulations (1.65 mm). The models were also able to predict fatigue life with average errors of 10.1 % (ANN) and 16.7 % (kNN), all achieved with a reduction of computational costs greater than 90 %.

Laboratory Investigations on Fracture Toughness of Self-compacting Concrete Containing Recycled Materials

This article investigates the fracture toughness in self-compacting concrete containing different percentages of recycled concrete materials using edge-notched disc bend (ENDB) samples. For this reason, 0, 25, 50, 75 and 100 percent of recycled aggregate were used instead of natural aggregate in the mixing designs. To obtain the fracture toughness, ENDB samples were used under loading of mixed mode I/III and pure modes I and III. Cubic samples were also used to obtain compressive strength. The results show that the compressive strength of the samples has a direct relationship with the fracture toughness and the reverse ratio with the percentage of recycled concrete materials. Also, samples containing 25% recycled materials have the highest compressive strength and fracture toughness. Furthermore, as the recycled percentage of the samples increases, the performance of samples against shear forces and compressive strength is reduced. Keywords: Fracture toughness, Mixed mode I/III, Recycled materials, Self-compacting concrete, ENDB sample

Two new species of Strandesia Stuhlmann, 1888 (Crustacea: Ostracoda) from Thailand, with first record of a male S. martensi Savatenalinton, 2015

Two new species of Strandesia Stuhlmann, 1888 are described from the northeastern part of Thailand: S. karanovicae sp. nov. and S. amnatcharoenensis sp. nov. Strandesia karanovicae is characterized by a tumid carapace in dorsal view, a small anterior overlap, the absence of a dorso-subapical seta on the first segment of the antennule (A1), a large aesthetasc Y on the antenna, an α seta shape with a needle-like tip and a large β seta on the mandibular palp (Md-palp), serrated bristles on the maxilla, a long h1 seta on the second thoracopod (T2) and a slender caudal ramus (CR). Strandesia amnatcharoenensis has a small compressed posterior part of the right valves (RV) which makes it closely related to S. pholpunthini Savatenalinton, 2015. The new species can be distinguished primarily by a considerably small anterior overlap of the left valve over the right valve (RV), a postero-ventral flange of the RV, a remarkably large claw Ga of the CR and the chaetotaxy of the limbs, especially A1, Md-palp and T2. In addition, in the present study, the sexual population of S. martensi Savatenalinton, 2015 is recorded for the first time, and thus the first description of the male is provided here. Moreover, the morphological examination of both males and females revealed differences between asexual and sexual females and also points to the fact that S. martensi is a mixed reproduction species. This is the first record of the mixed reproductive mode in the genus Strandesia or even in the Cypricercinae.

Mixed Variable Parameter Energy Storage-Assisted Frequency Support Strategy

With the continuous increase in the installed capacity of new energy systems, the impact of power shocks on grid frequency is becoming more significant, seriously affecting the stability of the grid and thermal power units. For this reason, a mixed variable parameter energy storage-assisted frequency support control method is proposed. This method introduces an integral control mode based on the existing control mode and forms a co-ordinated control mode. The impact of the switching point of the mixed control mode is analyzed, and a new mode switching method is used. The model adjusts the frequency regulation parameters according to the different states of the grid frequency, making the frequency regulation more efficient. Finally, a frequency regulation model that integrates various improvement methods is built, and a 10 min continuous load disturbance is applied to compare and verify the frequency regulation performance of the model as a whole. The results indicate that the proposed control method can significantly improve the quality of grid frequency regulation, reduce the frequency deviation amplitude to 0.00096 p.u., reduce the participation time of thermal power units to 190.8393 s, and reduce the peak output to 0.1934 MW, demonstrating its engineering feasibility.

Novel EDTA mediated ethanol protein precipitation method and the application for polysorbate quantification in high protein concentration biopharmaceuticals

Non-ionic surfactants such as Polysorbate 20/ 80 (PS20/ PS80), are commonly used in protein drug formulations to increase protein stability by protecting against interfacial stress and surface absorption. Polysorbate is susceptible to degradation which can impact product stability, leading to the formation of sub-visible and/or visible particles in the drug product during its shelf-life, affecting patient safety and efficacy. Therefore, it is important to monitor polysorbate concentration in drug product formulations of biotherapeutic drugs. The common method for measuring polysorbate concentration in drug product formulations uses mixed mode ion exchange reversed phase HPLC (MAX) coupled to evaporative light scattering detection (ELSD). However, high protein concentration can adversely impact method performance due to high sample viscosity, gel formation, column clogging, interfering peaks and loss of accuracy. To overcome this, a new method was developed based on EDTA mediated ethanol protein precipitation (EDTA/EtOH). This method was successfully implemented for the analysis of polysorbate in antibody formulations with wide range of protein concentration (10–250 mg/mL).

Electromagnetically driven flow in unsupported electrolyte layers: lubrication theory and linear stability of annular flow

We consider a thin horizontal layer of a non-magnetic electrolyte containing a bulk solution of salt and carrying an electric current. The layer is bounded by two deformable free surfaces loaded with an insoluble surfactant and is placed in a vertical magnetic field. The arising Lorentz force drives the electrolyte in the plane of the layer. We employ the long-wave approximation to derive general two-dimensional hydrodynamic equations describing symmetric pinching-type deformations of the free surfaces. These equations are used to study the azimuthal flow in an annular film spanning the gap between two coaxial cylindrical electrodes. In weakly deformed films, the base azimuthal flow and its linear stability with respect to azimuthally invariant perturbations are studied analytically. For relatively thick layers and weak magnetic fields, the leading mode with the smallest decay rate is found to correspond to a monotonic azimuthal velocity perturbation. The Marangoni effect leads to further stabilisation of the flow while perturbations of the solute concentration in the bulk of the fluid have no influence on the flow stability. In strongly deformed films in the diffusion-dominated regime, the azimuthal flow becomes linearly unstable with respect to an oscillatory mixed mode characterised by the combination of radial and azimuthal velocity perturbations when the voltage applied between electrodes exceeds the critical value.