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BMC Oral Health May 2024Erbium lasers safely offer the possibility of reuse for debonded restorations. Since these lasers have a high affinity for water molecules, they are absorbed by resin...
BACKGROUND
Erbium lasers safely offer the possibility of reuse for debonded restorations. Since these lasers have a high affinity for water molecules, they are absorbed by resin cement causing explosive ablation of the cement and thus, the restoration debonds. The efficiency of this process depends on many factors, including the ceramic type, its chemical composition and thickness. Therefore, this study was designed to test the time taken to debond ultrathin occlusal veneers made of three types of milled ceramic materials and evaluate the integrity of these restorations after debonding.
METHODS
Three ceramic types were evaluated in this study: lithium disilicate (IPS Emax CAD), highly condensed lithium disilicate (GC initial®LiSi), and translucent zirconia (Katana zirconia STML). Each group consisted of 8 occlusal veneers of 0.5 mm thickness. The samples were cemented to the occlusal surfaces of the upper molar teeth. An Er; Cr: YSGG laser was applied to the occlusal veneers using the scanning method, and time until debonding was calculated. The debonded samples were then inspected under a stereomicroscope for possible damage. Numerical data are presented as the mean with 95% confidence interval (CI), standard deviation (SD), minimum (min.) and maximum (max.) values. Normality and variance homogeneity assumptions were confirmed using Shapiro-Wilk's and Levene's tests, respectively. Data were normally distributed and were analyzed using one-way ANOVA followed by Tukey's post hoc test. The significance level was set at p < 0.05 for all tests. Statistical analysis was performed with R statistical analysis software version 4.3.2 for Windows (R Core Team (2023). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/).
RESULTS
There was no significant difference in debonding time between the different materials (p = 0.995). The longest debonding time was found for Katana STML (87.52 ± 20.45) (seconds), followed by Emax (86.94 ± 20.63) (seconds), while the lowest value was found for LiSi initial (86.14 ± 25.16) (seconds). In terms of damage to the debonded veneers, The Emax and zirconia samples showed no damage. However, 40% of the LiSi samples fractured during debonding, and 20% exhibited cracks. Only 40% of the LiSi samples were sound after debonding.
CONCLUSION
Er; Cr: YSGG laser can be used efficiently to remove ceramic occlusal veneers. However, its effect on LiSi restorations needs further research.
Topics: Dental Veneers; Computer-Aided Design; Ceramics; Dental Porcelain; Humans; Zirconium; Lasers, Solid-State; Dental Debonding; Materials Testing
PubMed: 38802801
DOI: 10.1186/s12903-024-04314-6 -
Plants (Basel, Switzerland) May 2024Milling quality directly affects production efficiency in rice, which is closely related to the brown rice recovery (BRR), the milled rice recovery (MRR) and the head...
Milling quality directly affects production efficiency in rice, which is closely related to the brown rice recovery (BRR), the milled rice recovery (MRR) and the head milled rice recovery (HMRR). The present study investigated these three traits in 173 germplasms in two environments, finding abundant phenotypic variation. Three QTLs for BRR, two for MRR, and three for HMRR were identified in a genome-wide association study, five of these were identified in previously reported QTLs and three were newly identified. By combining the linkage disequilibrium (LD) analyses, the candidate gene was identified. It had two haplotypes with significant differences and Hap 2 increased the BRR by 4.40%. The results of the qRT-PCR showed that the expression of in small-BRR accessions was significantly higher than that in large-BRR accessions at Stages 4-5 of young panicle development, reaching the maximum value at Stage 5. The increase in thickness of the spikelet hulls of the accession carrying occurred due to an increase in the cell width and the cell numbers in cross-sections of spikelet hulls. These results help to further clarify the molecular genetic mechanism of milling-quality-related traits and provide genetic germplasm materials for high-quality breeding in rice.
PubMed: 38794395
DOI: 10.3390/plants13101324 -
Sensors (Basel, Switzerland) May 2024Quenched Co-based ribbon strips are widely used in the fields of magnetic amplifier, magnetic head material, magnetic shield, electric reactor, inductance core, sensor...
Quenched Co-based ribbon strips are widely used in the fields of magnetic amplifier, magnetic head material, magnetic shield, electric reactor, inductance core, sensor core, anti-theft system label, and so on. In this study, Co-based composite CoFeNiSiB ribbon strips with a micron width were fabricated by micro-electro-mechanical systems (MEMS) technology. The carbon and FeCoGa nanofilms were deposited for surface modification. The effect of carbon and FeCoGa nanofilm coatings on the crystal structure, surface morphology, magnetic properties, and magnetoimpedance (MI) effect of composite ribbon strips were systematically investigated. The results show that the surface roughness and coercivity of the composite ribbon strips are minimum at a thickness of the carbon coating of 60 nm. The maximum value of MI effect is 41% at 2 MHz, which is approximately 2.4 times greater than plain ribbon and 1.6 times greater than FeCoGa-coated composite ribbon strip. The addition of a carbon layer provides a conductive path for high frequency currents, which effectively reduces the characteristic frequency of the composite ribbon strip. The FeCoGa coating is able to close the flux path and reduce the coercivity, which, in turn, increases the transverse permeability and improves the MI effect. The findings indicate that a successful combination of carbon layer and magnetostrictive FeCoGa nanofilm layer can improve the MI effect and magnetic field sensitivity of the ribbon strips, demonstrating the potential of the composite strips for local and micro area field sensing applications.
PubMed: 38793816
DOI: 10.3390/s24102961 -
Journal of Clinical Medicine May 2024: In this multicenter case series analysis, the authors present successful instances of 20 single-screw-retained and implant-supported prosthetic rehabilitation samples....
High-Density Dermal Matrix for Soft Tissue Augmentation Using a Matrix Tissue Graph Technique-A Comprehensive Multicenter Analysis of 20 Implants: A 1-Year Follow-Up Retrospective Study.
: In this multicenter case series analysis, the authors present successful instances of 20 single-screw-retained and implant-supported prosthetic rehabilitation samples. : A high-density heterologous dermal matrix (Derma Osteobiol by Tecnoss, Torino, Italy) was employed with a specific technique named the matrix tissue graft (MTG) in all these cases characterized by an inadequate initial supra-crestal tissue height (thin if 1 mm or medium if 2 mm) to enhance the peri-implant soft tissues both vertically and horizontally. : The implants were deemed successful in all cases, yielding a success proportion of 100% (one-sided 97.5% confidence interval = 83.2-100%). The buccal and lingual gains were, respectively, 2.2 ± 0.38 mm (range 1.7-3.22 mm) and 0.83 ± 0.33 mm (range 0.1-1.5 mm). These measurements were calculated as the maximum distance between two superimposed .stl file models (derived from two different IOS devices) scanned before implant placement and 1 year after dermal matrix healing. : An outstanding vertical and horizontal gain was obtained using this heterologous derma matrix placed above the bone crest and surrounding the dental implants.
PubMed: 38792495
DOI: 10.3390/jcm13102954 -
Journal of Clinical Medicine May 2024: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and...
: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and atherosclerosis-related body fat distribution in patients with type 2 diabetes mellitus and obesity. Resting brain perfusion single-photon emission computed tomography (SPECT) imaging with Technetium-99m hexamethylpropylene amine oxime ([Tc]Tc-HMPAO SPECT) was performed, and the breath-holding index (BHI) and carotid intima-media thickness (cIMT) were measured to characterise central microcirculation. Besides CT-based abdominal fat tissue segmentation, C-peptide level, glycaemic and anthropometric parameters were registered to search for correlations with cerebral blood flow and vasoreactivity. : Although no significant difference was found between the resting cerebral perfusion of the two patient cohorts, a greater blood flow increase was experienced in the obese after the breath-holding test than in the diabetics ( < 0.05). A significant positive correlation was encountered between resting and provocation-triggered brain perfusion and C-peptide levels ( < 0.005). BMI and cIMT were negatively correlated (rho = -0.27 and -0.23 for maximum and mean cIMT, respectively), while BMI and BHI showed a positive association (rho = 0.31 and rho = 0.29 for maximum and mean BHI, respectively), which could be explained by BMI-dependent changes in fat tissue distribution. cIMT demonstrated a disproportional relationship with increasing age, and higher cIMT values were observed for the men. Overall, C-peptide levels and circulatory parameters seem to be strong applicants to predict brain microvascular alterations and related cognitive decline in such patient populations.
PubMed: 38792441
DOI: 10.3390/jcm13102900 -
Molecules (Basel, Switzerland) May 2024Conducting polymers like polypyrrole, polyaniline, and polythiophene with nanostructures offers several advantages, such as high conductivity, a conjugated structure,...
Conducting polymers like polypyrrole, polyaniline, and polythiophene with nanostructures offers several advantages, such as high conductivity, a conjugated structure, and a large surface area, making them highly desirable for energy storage applications. However, the direct synthesis of conducting polymers with nanostructures poses a challenge. In this study, we employed a hard template method to fabricate polystyrene@polypyrrole (PS@PPy) core-shell nanoparticles. It is important to note that PS itself is a nonconductive material that hinders electron and ion transport, compromising the desired electrochemical properties. To overcome this limitation, the PS cores were removed using organic solvents to create hollow PPy nanospheres. We investigated six different organic solvents (cyclohexane, toluene, tetrahydrofuran, chloroform, acetone, and N,N-dimethylformamide (DMF)) for etching the PS cores. The resulting hollow PPy nanospheres showed various nanostructures, including intact, hollow, buckling, and collapsed structures, depending on the thickness of the PPy shell and the organic solvent used. PPy nanospheres synthesized with DMF demonstrated superior electrochemical properties compared to those prepared with other solvents, attributed to their highly effective PS removal efficiency, increased specific surface area, and improved charge transport efficiency. The specific capacitances of PPy nanospheres treated with DMF were as high as 350 F/g at 1 A/g. And the corresponding symmetric supercapacitor demonstrated a maximum energy density of 40 Wh/kg at a power density of 490 W/kg. These findings provide new insights into the synthesis method and energy storage mechanisms of PPy nanoparticles.
PubMed: 38792192
DOI: 10.3390/molecules29102331 -
Bioengineering (Basel, Switzerland) Apr 2024This study aimed to employ the incremental digital image correlation (DIC) method to obtain displacement and strain field data of the cornea from Corvis ST (CVS)...
PURPOSE
This study aimed to employ the incremental digital image correlation (DIC) method to obtain displacement and strain field data of the cornea from Corvis ST (CVS) sequences and access the performance of embedding these biomechanical data with machine learning models to distinguish forme fruste keratoconus (FFKC) from normal corneas.
METHODS
100 subjects were categorized into normal (N = 50) and FFKC (N = 50) groups. Image sequences depicting the horizontal cross-section of the human cornea under air puff were captured using the Corvis ST tonometer. The high-speed evolution of full-field corneal displacement, strain, velocity, and strain rate was reconstructed utilizing the incremental DIC approach. Maximum (max-) and average (ave-) values of full-field displacement V, shear strain γxy, velocity VR, and shear strain rate γxyR were determined over time, generating eight evolution curves denoting max-V, max-γxy, max-VR, max-γxyR, ave-V, ave-γxy, ave-VR, and ave-γxyR, respectively. These evolution data were inputted into two machine learning (ML) models, specifically Naïve Bayes (NB) and Random Forest (RF) models, which were subsequently employed to construct a voting classifier. The performance of the models in diagnosing FFKC from normal corneas was compared to existing CVS parameters.
RESULTS
The Normal group and the FFKC group each included 50 eyes. The FFKC group did not differ from healthy controls for age ( = 0.26) and gender ( = 0.36) at baseline, but they had significantly lower bIOP ( < 0.001) and thinner central cornea thickness (CCT) ( < 0.001). The results demonstrated that the proposed voting ensemble model yielded the highest performance with an AUC of 1.00, followed by the RF model with an AUC of 0.99. Radius and A2 Time emerged as the best-performing CVS parameters with AUC values of 0.948 and 0.938, respectively. Nonetheless, no existing Corvis ST parameters outperformed the ML models. A progressive enhancement in performance of the ML models was observed with incremental time points during the corneal deformation.
CONCLUSION
This study represents the first instance where displacement and strain data following incremental DIC analysis of Corvis ST images were integrated with machine learning models to effectively differentiate FFKC corneas from normal ones, achieving superior accuracy compared to existing CVS parameters. Considering biomechanical responses of the inner cornea and their temporal pattern changes may significantly improve the early detection of keratoconus.
PubMed: 38790296
DOI: 10.3390/bioengineering11050429 -
A prospective cohort study of factors associated with the digital cushion thickness in dairy cattle.Journal of Dairy Science May 2024Key factors such as stage of lactation, parity and body fat reserves have been associated with the digital cushion thickness, however, there are discrepancies between...
Key factors such as stage of lactation, parity and body fat reserves have been associated with the digital cushion thickness, however, there are discrepancies between the results of previously published studies. The objective of this study was to examine the association of stage of lactation, body fat reserves, parity, and lesion incidence with the digital cushion thickness (DCT) in a large cohort of intensively monitored cows. Across 4 UK farms, 2,352 cows were prospectively enrolled and assessed at 4 time points; before calving (T1-Precalving), immediately post-calving (T2-Calving), in early lactation (T3-Early) and late lactation (T4-Late). At each time point body condition score was recorded, the presence of sole lesions (sole ulcers and sole hemorrhage) and white line lesions were assessed by veterinarians, and an ultrasound image was taken to retrospectively measure the back-fat thickness in the pelvic (BFT) region and the digital cushion on the hind left lateral claw. Mixed effects multivariable linear regression models, with the cow as a random effect were fit to examine the association between explanatory variables and the DCT. Explanatory variables tested were farm, parity, stage of lactation, body condition score, BFT, height, the presence of a lesion at the time of measurement, the chronicity of a lesion during early lactation, predicted maximum daily milk yield and the rate of milk production rise in early lactation. Stage of lactation and farm were both associated with the DCT, however an interaction was present and this DCT pattern of change was farm dependent. Two distinct patterns emerged; one indicated the nadir to occur shortly after calving, the other indicated the nadir to occur during early lactation. Neither back fat thickness nor BCS were significantly associated with the DCT. Heifers displayed thinner digital cushions compared with multiparous cows, however, this effect was dependent on the stage of lactation, with heifers having a thinner digital cushion up until late lactation, by which time the DCT was commensurate with multiparous animals. Sole lesions and white line lesions at the time of measurement were associated with the DCT (sole lesion; Estimate: -0.07mm, 95% CI: -0.14-0.00, P = 0.039, white line lesion; Estimate: 0.28mm, 95% CI: 0.15-0.42, P < 0.001).
PubMed: 38788843
DOI: 10.3168/jds.2023-24563 -
Nanomaterials (Basel, Switzerland) May 2024Two-dimensional layered materials, characterized by their atomically thin thicknesses and surfaces that are free of dangling bonds, hold great promise for fabricating...
Two-dimensional layered materials, characterized by their atomically thin thicknesses and surfaces that are free of dangling bonds, hold great promise for fabricating ultrathin, lightweight, and flexible bipolar junction transistors (BJTs). In this paper, a van der Waals (vdW) BJT was fabricated by vertically stacking MoS, WSe, and MoS flakes in sequence. The AC characteristics of the vdW BJT were studied for the first time, in which a maximum common emitter voltage gain of around 3.5 was observed. By investigating the time domain characteristics of the device under various operating frequencies, the frequency response of the device was summarized, which experimentally proved that the MoS/WSe/MoS BJT has voltage amplification capability in the 0-200 Hz region. In addition, the phase response of the device was also investigated. A phase inversion was observed in the low-frequency range. As the operating frequency increases, the relative phase between the input and output signals gradually shifts until it is in phase at frequencies exceeding 2.3 kHz. This work demonstrates the signal amplification applications of the vdW BJTs for neuromorphic computing and wearable healthcare devices.
PubMed: 38786807
DOI: 10.3390/nano14100851 -
Cureus Apr 2024This study aimed to investigate optical coherence tomography (OCT) biomarkers as potential predictors of treatment response in chronic central serous chorioretinopathy...
PURPOSE
This study aimed to investigate optical coherence tomography (OCT) biomarkers as potential predictors of treatment response in chronic central serous chorioretinopathy (CSCR).
MATERIALS AND METHODS
It was a retrospective cohort study that included 42 patients with chronic CSCR. After complete ocular and hematological examinations, all patients received 50 mg/day of oral eplerenone for three months and were followed for at least six months. All participants were divided into two groups: Group 1 participants with a positive response to treatment (complete resolution of subretinal fluid (SRF) at six months) and Group 2 poor responders (moderate or less than 50% reduction in SRF from baseline). The primary outcome measure was the resolution of SRF, and various OCT biomarkers like central macular thickness (CMT), pigment epithelial detachments (PED), double-layer sign, elongation of the photoreceptor's outer segment, the integrity of the external limiting membrane, the integrity of the ellipsoid zone, hyperreflective foci in the outer segment, and subretinal deposits in the SRF were assessed.
RESULTS
The mean age was 41.33 ± 10.75 years, and 34 participants were male. Thirty-seven (88.1%) of the participants had good responses to eplerenone, with the mean height of SRF decreasing significantly from a maximum of 269.74 µm to a minimum of 21.86 µm at six months (p<0.001). The mean CMT decreased from the first visit time point to the third visit time (p<0.001). Logistic regression analysis assessed the absence of PED and double-layer signs associated with a good response.
CONCLUSION
The eplerenone therapy seems to be efficient for chronic CSCR, and OCT can be an invaluable aid to the treating physician.
PubMed: 38784343
DOI: 10.7759/cureus.58791