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Nanomaterials (Basel, Switzerland) May 2024In this work, Er-doped BiVO/BiFeO composites are prepared using the sonochemical process with a difference of rare earth loading compositions. The crystallinity and...
In this work, Er-doped BiVO/BiFeO composites are prepared using the sonochemical process with a difference of rare earth loading compositions. The crystallinity and chemical and morphological structure of as-synthesized samples were investigated via X-ray diffraction, Raman scattering, and electron microscopy, respectively. The diffuse reflectance technique was used to extract the optical property and calculate the optical band gap of the composite sample. The piezo-photocatalytic performance was evaluated according to the decomposition of a Rhodamine B organic compound. The decomposition of the organic compound was achieved under ultrasonic bath irradiation combined with light exposure. The Er-doped BiVO/BiFeO composite heterojunction material exhibited significant enhancement of the piezo-photocatalytic activity under both ultrasonic and light irradiation due to the improvement in charge generation and separation. The result indicates that Er dopant strongly affects the phase transformation, change in morphology, and alternation in optical band gap of the BiVO matrix. The incorporation of BiFeO in the composite form with BiVO doped with 1%Er can improve the photocatalytic performance of BiVO via piezo-induced charge separation and charge recombination retardment.
PubMed: 38869579
DOI: 10.3390/nano14110954 -
Journal of International Society of... 2024The success of composite restorations relies on material selection and practitioner-related factors that shape the overall outcome. This study explores the practices of...
AIM
The success of composite restorations relies on material selection and practitioner-related factors that shape the overall outcome. This study explores the practices of Palestinian general dental practitioners in placing posterior composites, examining the impact of work sector, experience, and gender on their choices.
MATERIALS AND METHODS
The study was conducted as an online cross-sectional questionnaire and involved 351 participants, with a response rate of 69.8%. The survey comprised 18 closed-ended questions covering demographics, material selection, and composite placement in special cases, techniques, and factors influencing the choices. Statistical analyses included descriptive statistics, chi-squared tests, and Fisher's exact tests.
RESULTS
Composite was the predominant choice for small-size (83.7%) and large-size posterior cavities (60.4%). Practitioners commonly opted for composite restorations in cases involving occlusal parafunctional activity (60%), poor oral hygiene (78%), and subgingival cavities (72.2%). Only 19.6% and 5.3% reported occlusal and gingival beveling, respectively. Rubber dams for isolation stood at 30%, one-step self-etch adhesives at 44.9%, and the oblique layering technique at 51%. Light-emitting diode curing units were popular (97.55%), but monitoring output with a radiometer was infrequent (93.5%). Tofflemire metal matrix usage was 46.1%, whereas a sectional matrix system was employed by 29.8%. A 2 mm layer exposure to light curing for 20 s was reported by 62%, and 27.75% utilized additional light-curing postmatrix band removal.
CONCLUSION
The study highlights the need for Palestinian dental professionals to update their clinical approaches in placing composite restorations in posterior teeth. Gender, work sector, and experience influence practitioners' choices, emphasizing the importance of tailored continuing education programs for improving clinical practices.
PubMed: 38827352
DOI: 10.4103/jispcd.jispcd_157_23 -
Scientific Reports May 2024This work presents a facile approach for controlling the optical and electrical parameters of a biopolymeric matrix for optoelectronics. Vanadium oxide (VO) and chromium...
This work presents a facile approach for controlling the optical and electrical parameters of a biopolymeric matrix for optoelectronics. Vanadium oxide (VO) and chromium oxide (CrO) nanoparticles (NPs) were prepared and incorporated into the carboxymethylcellulose/polyethylene glycol (CMC/PEG) blend by simple chemical techniques. Transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD) data showed that VO and CrO exhibited spherical shapes with sizes in the range of 40-50 nm and 10-20 nm, respectively. In addition, the blend's degree of crystallinity was sensitive to the VO and CrO doping ratios. The scanning electron microscopy (FE-SEM) and the elemental chemical analysis (EDAX) used to study the filler distribution inside the blend, and confirmed the existence of both V and Cr in the matrix. Fourier transform infrared (FTIR) spectroscopy showed that the dopants significantly affected the blend reactive (C-O-C, OH, and C=O) groups. The stress-strain curves illustrated the reinforcing effect of the dopants up to 1.0 CrO/V. The transmittance and absorption index spectra in the visible-IR wavelengths decreased with increasing filler content. Utilizing Tauc's relation and (optical) dielectric loss, the direct (indirect) band gap narrowed from 5.6 (4.5) eV to 4.7 (3.05) eV at 1.0 CrO/V. All films have an index of refraction in the range of 1.93-2.17. AC conductivity was improved with increasing filler content and temperature. The energy density at 50 °C is in the range of 1-3 J/m. The influence of VO and CrO content on the optical conductivity, dielectric constant, loss, and dielectric modulus of CMC/PEG was reported. These enhancements in electrical and optical properties, along with the potential for band gap engineering, offer promising prospects for advanced applications in optoelectronics and energy-related fields.
PubMed: 38822031
DOI: 10.1038/s41598-024-62643-6 -
Heliyon May 2024New calcium borovanadate glass containing manganese ions within the system x MnO-(30-x) VO-50 BO-20 CaO has been elaborated in this work using melt quench process. The...
New calcium borovanadate glass containing manganese ions within the system x MnO-(30-x) VO-50 BO-20 CaO has been elaborated in this work using melt quench process. The primary objective of this research is to examine the influence of introducing MnO upon the various properties of the elaborated glass specimens including physical, thermal, structural, optical and magnetic properties. X-ray diffraction indicated that the samples prepared were amorphous. The variation in density and molar volume revealed that the structure of the glass matrix cross-links and becomes more compact with increasing MnO content, which is confirmed when the glass transition temperature is increased. Furthermore, in order to check the group constitution of our glasses, a structural study was carried out using infrared (FTIR) and Raman spectroscopy. The optical characteristics of our vitreous materials were analyzed by UV solid, and the results of the band gap energy and refractive index values revealed an enhancement of non-bridging oxygen atoms (NBOs) with rising MnO concentration, also suggests that manganese acts as a structure modifier. The low Urbach energy values are an indication that the structure of our glasses is stable and uniform. The magnetic investigation highlighted the presence of the predominant antiferromagnetic order in the glass samples studied, which becomes stronger with the incorporation of more manganese ions into the structure.
PubMed: 38807897
DOI: 10.1016/j.heliyon.2024.e31219 -
Polymers May 2024Nanotechnology is one of the newest directions for plant-based therapies. Chronic venous disease often predisposes to long-term and invasive treatment. This research...
Preparation and Preliminary Analysis of Several Nanoformulations Based on Plant Extracts and Biodegradable Polymers as a Possible Application for Chronic Venous Disease Therapy.
Nanotechnology is one of the newest directions for plant-based therapies. Chronic venous disease often predisposes to long-term and invasive treatment. This research focused on the inclusion of vegetal extracts from (SE), (CE), and (GE) in formulations with PHB and PLGA polymers and their physicochemical characterization as a preliminary stage for possible use in the development of a complex therapeutic product. The samples were prepared by an oil-water emulsification and solvent evaporation technique, resulting in suspensions with high spreadability and a pH of 5.5. ATR-FTIR analysis revealed bands for stretching vibrations (O-H, C=O, and C-H in symmetric and asymmetric methyl and methylene) in the same regions as the base components, but switched to high or low wavenumbers and absorbance, highlighting the formation of adducts/complexes between the extracts and polymers. The obtained formulations were in the amorphous phase, as confirmed by XRD analysis. AFM analysis emphasized the morphological peculiarities of the extract-polymer nanoformulations. It could be noticed that, in the case of SE-based formulations, the dominant characteristics for SE-PHB and SE-PLGA composition were the formation of random large (SE-PHB) and smaller uniform (SE-PLGA) particles; further on, these particles tended to aggregate in the case of SE-PHB-PLGA. For the CE- and GE-based formulations, the dominant surface morphology was their porosity, generally with small pores, but larger cavities were observed in some cases (CE- and GE-PHB). The highest roughness values at the (8 µm × 8 μm) scale were found for the following samples and succession: CE-PHB < SE-PLGA < SE-PHB-PLGA. In addition, by thermogravimetric analysis, impregnation in the matrix of compression stockings was evaluated, which varied in the following order: CE-polymer > SE-polymer > GE-polymer. In conclusion, nine vegetal extract-polymer nanoformulations were prepared and preliminarily characterized (by advanced physicochemical methods) as a starting point for further optimization, stability studies, and possible use in complex pharmaceutical products.
PubMed: 38794552
DOI: 10.3390/polym16101362 -
Polymers May 2024Polymeric hybrid films, for their application in organic electronics, were produced from new ruthenium indanones in poly(methyl methacrylate) (PMMA) by the drop-casting...
Polymeric hybrid films, for their application in organic electronics, were produced from new ruthenium indanones in poly(methyl methacrylate) (PMMA) by the drop-casting procedure. Initially, the synthesis and structural characterization of the ruthenium complexes were performed, and subsequently, their properties as a potential semiconductor material were explored. Hence hybrid films in ruthenium complexes were deposited using PMMA as a polymeric matrix. The hybrid films were characterized by infrared spectrophotometry and atomic force microscopy. The obtained results confirmed that the presence of the ruthenium complexes enhanced the mechanical properties in addition to increasing the transmittance, favoring the determination of their optical parameters. Both hybrid films exhibited a maximum stress around 10.5 MPa and a Knoop hardness between 2.1 and 18.4. Regarding the optical parameters, the maximum transparency was obtained at wavelengths greater than 590 nm, the optical band gap was in the range of 1.73-2.24 eV, while the Tauc band gap was in the range of 1.68-2.17 eV, and the Urbach energy was between 0.29 and 0.50 eV. Consequently, the above comments are indicative of an adequate semiconductor behavior; hence, the target polymeric hybrid films must be welcomed as convenient candidates as active layers or transparent electrodes in organic electronics.
PubMed: 38794531
DOI: 10.3390/polym16101338 -
Sensors (Basel, Switzerland) May 2024Modular control of the muscle, which is called muscle synergy, simplifies control of the movement by the central nervous system. The purpose of this study was to explore...
Modular control of the muscle, which is called muscle synergy, simplifies control of the movement by the central nervous system. The purpose of this study was to explore the synergy in both the frequency and movement domains based on the non-negative Tucker decomposition (NTD) method. Surface electromyography (sEMG) data of 8 upper limb muscles in 10 healthy subjects under wrist flexion (WF) and wrist extension (WE) were recorded. NTD was selected for exploring the multi-domain muscle synergy from the sEMG data. The results showed two synergistic flexor pairs, Palmaris longus-Flexor Digitorum Superficialis (PL-FDS) and Extensor Carpi Radialis-Flexor Carpi Radialis (ECR-FCR), in the WF stage. Their spectral components are mainly in the respective bands 0-20 Hz and 25-50 Hz. And the spectral components of two extensor pairs, Extensor Digitorum-Extensor Carpi Ulnar (ED-ECU) and Extensor Carpi Radialis-Brachioradialis (ECR-B), are mainly in the respective bands 0-20 Hz and 7-45 Hz in the WE stage. Additionally, further analysis showed that the Biceps Brachii (BB) muscle was a shared muscle synergy module of the WE and WF stage, while the flexor muscles FCR, PL and FDS were the specific synergy modules of the WF stage, and the extensor muscles ED, ECU, ECR and B were the specific synergy modules of the WE stage. This study showed that NTD is a meaningful method to explore the multi-domain synergistic characteristics of multi-channel sEMG signals. The results can help us to better understand the frequency features of muscle synergy and shared and specific synergies, and expand the study perspective related to motor control in the nervous system.
Topics: Humans; Electromyography; Muscle, Skeletal; Male; Wrist; Adult; Movement; Female; Young Adult; Signal Processing, Computer-Assisted
PubMed: 38794079
DOI: 10.3390/s24103225 -
Sensors (Basel, Switzerland) May 2024Aiming at the problem that ultra-wide band (UWB) cannot be accurately localized in environments with large noise variations and unknown statistical properties, a...
Aiming at the problem that ultra-wide band (UWB) cannot be accurately localized in environments with large noise variations and unknown statistical properties, a combinatorial localization method based on improved cubature (CKF) is proposed. First, in order to overcome the problem of inaccurate local approximation or even the inability to converge due to the initial value not being set near the optimal solution in the process of solving the UWB position by the least-squares method, the Levenberg-Marquardt algorithm (L-M) is adopted to optimally solve the UWB position. Secondly, because UWB and IMU information are centrally fused, an adaptive factor is introduced to update the measurement noise covariance matrix in real time to update the observation noise, and the fading factor is added to suppress the filtering divergence to achieve an improvement for the traditional CKF algorithm. Finally, the performance of the proposed combined localization method is verified by field experiments in line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios, respectively. The results show that the proposed method can maintain high localization accuracy in both LOS and NLOS scenarios. Compared with the Extended Kalman filter (EKF), unbiased Kalman filter (UKF), and CKF algorithms, the localization accuracies of the proposed method in NLOS scenarios are improved by 25.2%, 18.3%, and 11.3%, respectively.
PubMed: 38794017
DOI: 10.3390/s24103165 -
Sensors (Basel, Switzerland) May 2024High-precision positioning and multi-target detection have been proposed as key technologies for robotic path planning and obstacle avoidance. First, the Cartographer...
High-precision positioning and multi-target detection have been proposed as key technologies for robotic path planning and obstacle avoidance. First, the Cartographer algorithm was used to generate high-quality maps. Then, the iterative nearest point (ICP) and the occupation probability algorithms were combined to scan and match the local point cloud, and the positions and attitudes of the robot were obtained. Furthermore, Sparse Matrix Pose Optimization was carried out to improve the positioning accuracy. The positioning accuracy of the robot in x and y directions was kept within 5 cm, the angle error was controlled within 2°, and the positioning time was reduced by 40%. An improved timing elastic band (TEB) algorithm was proposed to guide the robot to move safely and smoothly. A critical factor was introduced to adjust the distance between the waypoints and the obstacle, generating a safer trajectory, and increasing the constraint of acceleration and end speed; thus, smooth navigation of the robot to the target point was achieved. The experimental results showed that, in the case of multiple obstacles being present, the robot could choose the path with fewer obstacles, and the robot moved smoothly when facing turns and approaching the target point by reducing its overshoot. The proposed mapping, positioning, and improved TEB algorithms were effective for high-precision positioning and efficient multi-target detection.
PubMed: 38793954
DOI: 10.3390/s24103100