Clinical efficacy of intraoral ultrasonography versus transgingival probing for measurement of gingival thickness in different gingival biotypes: a clinical trial

BACKGROUND

Transgingival probing is conventionally used for gingival thickness (GT) measurement. However, invasiveness is a major drawback of transgingival probing. Thus, researchers have been in search of alternative methods for measurement of GT. This study compared the clinical efficacy of intraoral ultrasonography and transgingival probing for measurement of GT in different biotypes.

MATERIALS AND METHODS

This clinical trial was conducted on 34 patients requiring crown lengthening surgery. GT was measured at 40 points with 2- and 4-mm distances from the free gingival margin (FGM) of anterior and premolar teeth of both jaws in each patient by an intraoral ultrasound probe. For measurement of GT by the transgingival probing method, infiltration anesthesia was induced, and a #25 finger spreader (25 mm) was vertically inserted into the soft tissue until contacting bone. The inserted length was measured by a digital caliper with 0.01 mm accuracy. All measurements were made by an operator with high reliability under the supervision of a radiologist. Data were analyzed by t-test, Power and Effect Size formula, and intraclass correlation coefficient (ICC).

RESULTS

The two methods were significantly different in measurement of GT in both thick and thin biotypes at 2- and 4-mm distances (P < 0.001). The two methods had a significant difference in both the mandible (P < 0.001) and maxilla (P < 0.001) and in both the anterior (P < 0.003) and premolar (P < 0.003) regions. Although the difference was statistically significant in t-tests, the power and effect formula proved it to be clinically insignificant. Also, the ICC of the two methods revealed excellent agreement.

CONCLUSION

The results showed optimal agreement of ultrasound and transgingival probing for measurement of GT.

TRIAL REGISTRATION

The study was approved by the ethics committee of Shahid Beheshti University of Medical Sciences on 2021-12-28 (IR.SBMU.DRC.REC.1400.138) and registered in the Iranian Registry of Clinical Trials on 2022-03-14 (IRCT20211229053566N1).

Numerical simulation based performance enhancement approach for an inorganic BaZrS3/CuO heterojunction solar cell

One of the main components of the worldwide transition to sustainable energy is solar cells, usually referred to as photovoltaics. By converting sunlight into power, they lessen their reliance on fossil fuels and the release of greenhouse gases. Because solar cells are decentralized, distributed energy systems may be developed, which increases the efficiency of the cells. Chalcogenide perovskites have drawn interest due to their potential in solar energy conversion since they provide distinctive optoelectronic characteristics and stability. But high temperatures and lengthy reaction periods make it difficult to synthesise and process them. Therefore, we present the inaugural numerical simulation using SCAPS-1D for emerging inorganic BaZrS3/CuO heterojunction solar cells. This study delves into the behaviour of diverse parameters in photovoltaic devices, encompassing efficiency (η) values, short-circuit current density (Jsc), fill factor (FF), and open-circuit voltage (Voc). Additionally, we thoroughly examine the impact of window and absorber layer thickness, carrier concentration, and bandgap on the fundamental characteristics of solar cells. Our findings showcase the attainment of the highest efficiency (η) values, reaching 27.3% for our modelled devices, accompanied by Jsc values of 40.5 mA/cm2, Voc value of 0.79 V, and FF value of 85.2. The efficiency (η) values are chiefly influenced by the combined effects of Voc, Jsc, and FF values. This optimal efficiency was achieved with CuO thickness, band gap, and carrier concentration set at 5 µm, 1.05 eV, and above 1019 cm-3, respectively. In comparison, the optimal parameters for BaZrS3 include a thickness of 1 µm, a carrier concentration below 1020 cm-3, and a band gap less than 1.6 eV. Therefore, in the near future, the present simulation will simultaneously provide up an entirely novel field for the less defective perovskite solar cell.

Comparison of ultrasonography-based masticatory muscle thickness between temporomandibular disorders bruxers and temporomandibular disorders non-bruxers

To compare masticatory muscle thickness in patients with temporomandibular disorders (TMDs) during rest and clenching, and by body position, using ultrasonography. This prospective study included 96 patients with TMD (67 females, 29 males; mean age: 40.41 ± 17.88 years): group 1, comprising 66 patients with TMD without bruxism (TMD_nonbruxer), and group 2, comprising 30 patients with concurrent TMD and bruxism (TMD_bruxer). In patients with TMD, bruxism was correlated with the presence of tinnitus, muscle stiffness, sleep problems, psychological stress, and restricted mouth opening. The masseter muscle significantly thickened during clenching (11.16 ± 3.03 mm vs 14.04 ± 3.47 mm, p < 0.001), whereas the temporalis muscle showed no significant increase in thickness from resting to clenching in an upright position (7.91 ± 1.98 vs 8.39 ± 2.08, p = 0.103). Similarly, during clenching in the supine position, the masseter muscle was significantly thicker compared with rest (11.24 ± 2.42 vs 13.49 ± 3.09, p < 0.001), but no significant difference was observed in temporal muscle thickness (8.21 ± 2.16 vs 8.43 ± 1.94, p = 0.464). In comparison between two groups, the average thickness of the masseter muscle was greater among TMD_bruxers than among TMD_nonbruxers in both the upright and supine positions (all p < 0.05). In the generalized lineal model, female sex (B = - 1.018, 95% confidence interval [CI] - 1.855 to - 0.181, p = 0.017) and bruxism (B = 0.868, 95% CI 0.567 to 1.169, p = 0.048) significantly predicted changes in masseter muscle thickness. Female sex (B = - 0.201, 95% CI - 0.299 to - 0.103, p = 0.011), increased age (B = - 0.003, 95% CI - 0.005 to 0.000, p = 0.038), and muscle stiffness (B = - 1.373, 95% CI - 2.369 to - 0.376, p = 0.007) were linked to decreased temporal muscle thickness. Comparing TMD nonbruxer and bruxer muscle thicknesses in upright and supine positions revealed significant increased thickness in the masseter muscle during clenching but not in the temporalis muscle. Masseter muscle thickness varied significantly by sex, body position, and resting/clenching, notably influenced by bruxism. These findings emphasize the relevance of these factors in clinical examinations of patients with TMD.

A new possible marker: can pennation angle defined by ultrasound predict the frailty?

BACKGROUND

Frailty indicates older people who are vulnerable to stressors. The relation between ultrasonographic parameters of muscle and frailty among older people has yet to be investigated.

AIMS

The aim of the study is to investigate the relationship between frailty and the ultrasonographic measurements of the rectus femoris muscle (RFM).

METHODS

This cross-sectional study included 301 participants who were ≥65 years. The FRAIL questionnaire assessed frailty. The thickness, cross-sectional area (CSA), fascicle length, pennation angle (PA), stiffness, and echogenicity of RFM were assessed by ultrasound. The accuracy of parameters in predicting the frailty was evaluated by ROC analysis.

RESULTS

Of all 301 participants, 24.6% were frail. Pre-frail and frail participants had significantly lower thickness (p = 0.002), CSA (p = 0.009), and fascicle length (p = 0.043) of RFM compared to robust. PA was significantly lowest in frails (p < 0.001). The multivariate logistic regression analysis showed that PA values lower than 10.65 degrees were an independent predictor of frailty (OR = 0.83, 95% Cl: 0.70-0.97, p = 0.019). Results of ROC analysis demonstrated a satisfactory result between the PA and frailty (AUC = 0.692, p < 0.001).

DISCUSSION

Thickness, CSA, and PA of RFM were found to be lower in frail subjects, which may indicate the changes in muscle structure in frailty. Among all parameters, lower PA values were independent predictors of frailty. These findings may indicate a novel ultrasound-based method in frailty, that is more objective and unrelated to the cross-sectional evaluation.

CONCLUSIONS

Ultrasonographic measurements of RFM, especially the lower PA may predict frailty in older people. As an objective and quantitative method, PA may be used to define frailty with acceptable sensitivity.

Development of a prediction model for facilitating the clinical application of transcranial color-coded duplex ultrasonography

BACKGROUND

Transcranial color-coded duplex ultrasonography (TCCD) is an important diagnostic tool in the investigation of cerebrovascular diseases. TCCD is often hampered by the temporal window that ultrasound cannot penetrate. Rapidly determine whether ultrasound can penetrate the temporal window in order to determine whether to use other acoustic windows to complete the examination process. In this study, Skull thickness can be measured simultaneously during TCCD examination, which makes it possible to use skull thickness to rapidly determine whether the temporal window is penetrated by ultrasound.

METHODS

This retrospective study included 301 patients with clinical symptoms of cerebrovascular diseases. These 301 patients were divided into an impenetrable temporal window (ITW) group and a penetrable temporal window group according to the results of the TCCD examination.

RESULTS

The area under the receiver operating characteristic (ROC) curve (AUC) for skull thickness was 0.887 (cutoff value 1.045 cm). Following multivariate logistic regression, sex, age, and skull thickness were used to develop a nomogram. The AUC for the nomogram was 0.923 (cutoff value 0.407).

CONCLUSIONS

The skull thickness at the temporal window was measured by ultrasound, which was convenient and accurate. The probability of ITW in females was higher than that in males, and it increased with age. In this study, a prediction model incorporating sex, age and skull thickness could predict ITW probability well. If the patient's temporal window was rapidly predicted as an ITW, other acoustic window examinations were used to complete the TCCD examination process to optimize the TCCD examination process of cerebrovascular diseases and facilitate the popularization of TCCD in clinical application.

Corneal Stress Distribution Evolves from Thickness-Driven in Normal Corneas to Curvature-Driven with Progression in Keratoconus

Purpose

To introduce the novel parameter of Corneal Contribution to Stress (CCS) and compare stress distribution patterns between keratoconus (KCN) and normal corneas.

Design

Prospective, observational, cross-sectional study.

Participants

The study included 66 eyes of 40 subjects diagnosed with KCN and 155 left eyes from 155 normal control (NRL) subjects.

Methods

Tomography was obtained to calculate the newly proposed CCS, defined according to the hoop stress formula without intraocular pressure, R/2t, where R is the radius of curvature and t is the thickness. CCS maps were calculated from pachymetry and tangential curvature maps. Custom software identified the 2-mm-diameter zones of greatest curvature (Cspot-max), thinnest pachymetry (Pach-min), greatest stress (CCSmax), and lowest stress (CCSmin). Stress difference (CCSdiff) was calculated as CCSmax - CCSmin. Distances between Cspot-max vs. Pach-min, vs. CCSmax, and vs. CCSmin, as well as between Pach-min vs. CCSmax and vs. CCSmin, were calculated. t tests were performed between cohorts, and paired t tests were performed within cohorts. Univariate linear regression analyses were performed between parameters and distances. The significance threshold was P < 0.05.

Main Outcome Measures

Corneal stress parameters, corneal features of maximum curvature, minimum thickness, and distances between corneal stress parameters and corneal features.

Results

CCSmax was significantly closer to Pach-min (0.79 ± 0.92) and Cspot-max (2.04 ± 0.85) than CCSmin (3.17 ± 0.38, 2.73 ± 1.53, respectively) in NRL, P < 0.0001, whereas CCSmin was significantly closer to Cspot-max (1.35 ± 1.43) than CCSmax (2.52 ± 0.72) in KCN, P < 0.0001. Cspot-max (severity) was significantly related to CCSdiff in KCN (P < 0.0001; R2 = 0.5882) with a weak relationship in NRL (P < 0.0080, R2 = 0.0451). Cspot-max was significantly related to the distance from Pach-min to CCSmax (P < 0.0001; R2 = 0.3737) without significance in NRL (P = 0.8011).

Conclusions

Corneal stress is driven by thickness in NRL, with greatest stress at thinnest pachymetry and greatest curvature. However, maximum stress moves away from thinnest pachymetry with progression in KCN, and minimum stress is associated with maximum curvature. Severity in KCN is significantly related to greater difference between maximum and minimum stress, consistent with the biomechanical cycle of decompensation.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Nuance and profound impact: Evaluating the effects of the unmet full coma scale in patients with mild subdural hemorrhage

INTRODUCTION

Patients with subdural hemorrhage (SDH) and a Glasgow Coma Scale (GCS) score of 13-15 are typically categorized as having mild traumatic brain injury. We hypothesize that patients without a maximum GCS score - specifically, patients with GCS scores of 13 and 14 - may exhibit poorer neurological outcomes.

METHOD

Between January 1, 2019, and December 31, 2020, SDH patients with GCS scores ranging from 13 to 15 were retrospectively studied. We compared outcomes between patients with a maximum GCS score of 15 and those with scores of either 13 or 14. Independent factors associated with neurological deterioration among patients with a GCS score of 15 were evaluated using multivariate logistic regression (MLR) analysis.

RESULTS

During the study period, 470 patients with SDH and GCS scores between 13 and 15 were examined. Compared to patients with a maximum GCS score (N = 375), those in the GCS 13-14 group (N = 95) showed significantly higher rates of neurological deterioration (33.7% vs. 10.4%, p value <0.001) and neurosurgical interventions (26.3% vs. 16.3%, p value <0.024). Moreover, the GCS 13-14 group had a significantly poorer prognosis than patients with a GCS score of 15 [mortality rate: 7.4% vs. 2.4%, p value <0.017; rate of impaired consciousness at discharge: 21.1% vs. 4.0%, p value <0.001; and rate of neurological disability at discharge: 29.5% vs. 6.9%, p value <0.001]. The MLR analysis revealed that SDH thickness (odds ratio = 1.127, p value = 0.006) was an independent risk factor for neurological disability at discharge in patients with a GCS score of 15.

CONCLUSION

Among SDH patients with mild TBI, those with GCS scores of 13-14 exhibited poorer neurological outcomes than those with a maximum GCS score. The thickness of the SDH is positively associated with neurological disability in SDH patients with a maximum GCS score.

Light transmittance through resin-matrix composite onlays adhered to resin-matrix cements or flowable composites

OBJECTIVE

The aim of this study was to evaluate the influence of the thickness of resin-matrix composite blocks manufactured by CAD-CAM on the light transmittance towards different resin-matrix cements or flowable composites.

METHODS

Sixty specimens of resin-matrix composite CAD-CAM blocks reinforced with 89 wt% inorganic fillers were cross-sectioned with 2 or 3 mm thicknesses. The specimens were conditioned with adhesive system and divided in groups according to the luting material, namely: two dual-cured resin-matrix cements, two traditional flowable resin-matrix composites, and one thermal-induced flowable resin-matrix composite. Specimens were light-cured at 900 mW/cm2 for 40s. Light transmittance assays were preformed using a spectrophotometer with an integrated monochromator before and after light-curing. Microstructural analysis was performed by optical and scanning electron microscopy (SEM). Nanoindentation tests were performed to evaluate mechanical properties for indirect evaluation of degree of monomers conversion.

RESULTS

Optical and SEM images revealed low thickness values for the cementation interfaces for the traditional flowable resin-matrix composite. The cement thickness increased with the size and content of inorganic fillers. The highest light transmittance was recorded for the onlay blocks cemented with the traditional flowable resin-matrix composites while a group cemented with the dual-cured resin-matrix cement revealed the lowest light transmittance. The elastic modulus and hardness increased for specimens with high content of inorganic fillers as well as it increased in function of the light transmittance.

CONCLUSIONS

The light transmittance of flowable resin-matrix composites was higher than that for resin-matrix cement after cementation to resin-matrix composites blocks. The type, size, and content of inorganic fillers of the luting material affected the thickness of the cement layer and light transmittance through the materials.

CLINICAL RELEVANCE

On chair-side light curing, the transmission of visible light can be interfered by the chemical composition and viscosity of the luting materials. The increase in size and content of inorganic fillers of resin-matrix composites and luting materials can decrease the light transmittance leading to inefficient polymerization.

Senile Cataract Formation Does Not Affect Crystalline Lens Thickness

INTRODUCTION

Characterizing lens thickness (LT) in patients with cataracts is important for better understanding the lens aging process and for designing new intraocular lens power formulas. This study aimed to analyze the influence of common senile cataract formation on the LT, anterior (ACS) and posterior (PCS) cortex space, and nuclear thickness (NT), controlling for sex, age, and axial length.

METHODS

A cross-sectional study was performed. A consecutive sample of 603 volunteers (403 women, 200 men) aged 59.1 ± 18.8 years was recruited. The standardized Lens Opacification Classification System (LOCS)-III was used to classify eyes (randomly selected) into cataractous and non-cataractous groups. Also, they were classified according to the cataract location (presence or absence of cortical, nuclear, or posterior subcapsular cataract). Optical biometry was performed to measure LT, ACS, NT, and PCS. Propensity score was used to match participants one-to-one for sex, age, and axial length. Groups were compared using the Student's t test or Yuen's test.

RESULTS

The four classifications divided unmatched eyes into: 361 cataractous lenses and 242 non-cataractous, 226 cortical and 377 non-cortical cataractous, 313 nuclear and 290 non-nuclear cataractous and 242 subcapsular and 361 non-subcapsular cataractous. Before matching, cataractous eyes showed significantly higher LT (4.52 ± 0.39 vs. 3.94 ± 0.46 mm, p < 0.001), ACS (0.75 ± 0.20 vs. 0.58 ± 0.23 mm, p < 0.001), NT (3.34 ± 0.23 vs. 3.18 ± 0.25 mm, p < 0.001) and PCS (0.42 ± 0.19 vs. 0.37 ± 0.19 mm, p = 0.003). Matched lens, cortical, nuclear, and subcapsular cataract samples comprised 146, 258, 182, and 226 eyes, respectively. After matching, no significant differences were observed in LT (4.34 ± 0.37 vs. 4.33 ± 0.36 mm, p = 0.94), ACS (0.72 ± 0.20 vs. 0.76 ± 0.19 mm, p = 0.08), NT (3.31 ± 0.22 vs. 3.30 ± 0.23 mm, p = 0.24) and PCS (0.42 ± 0.19 vs. 0.43 ± 0.16 mm, p = 0.79).

CONCLUSIONS

The presence of senile cortical, nuclear, and posterior subcapsular cataract have no effect on LT, ACS, NT, and PCS. Confounding factors should be controlled for when measuring LT and its main components.

Thickness ranges calculation method of double asphalt overlay on concrete pavement

Asphalt overlay is widely used in maintaining and rehabilitating highway system performance. However, explicit calculation methods for the asphalt overlay thickness range is lacking. Taking stone mastic asphalt (SMA) and asphalt concrete (AC) asphalt overlay on cement concrete pavement as examples, the paper proposed a design method for the asphalt overlay thickness range based on the shear performance of the interlayer. Firstly, the shear stress distribution regularities on the asphalt overlay and Portland cement concrete interlayer was calculated with a multilayer elastic theory. Meanwhile, the shear strength was obtained from a series of direct shear tests. The shear characters of the asphalt overlay met with the Mohr-Coulomb criterion, and the shear strength parameters cohesive force c and interface friction angle φ on the interlayer were acquired. Finally, a method for determining the thickness range of double layer asphalt overlay under different traffic conditions was given. The epoxy resin adhesive was recommended for the highway with severe local premature shear failure compared with the modified emulsion asphalt. Therefore, through the above research, the amount of asphalt used is controlled in a reasonable range, thus improving the pavement structure durability and reducing energy consumption.

Gradual and synergistic correlation of tumor thickness and histological grade in penile invasive carcinomas

Histological grade and depth of invasion are among the best outcome pathological predictors in penile cancer. The TNM system is based on a combination of both for some stages. It is assumed that high-grade and deep tumors carry the worst prognosis, and the opposite occurs with superficial and low-grade neoplasms. However, there is no systematic evaluation of the phenomenon. We studied 147 patients from the Hospital de Oncologia - Instituto Mexicano del Seguro Social (period 2000 to 2013). They were treated by total or partial penectomies. Lymph node involvement was evaluated by bilateral inguinal node dissection (126 cases) or ultrasonography (21 cases). Tumor thickness was measured in mm from tumor surface to deepest invasion point, using a cut-point for superficial (≤10 mm) vs deep (>10 mm) tumors. Histological grade was from 1 to 3 according to WHO and AFIP criteria and considering G1 and G2 as low-grade and G3 as high-grade. Average age was 62 (26-98) years old. Tumor thickness mean was 15 mm (2-30 mm). G1, G2 and G3 tumors corresponded to 19 (13 %), 48 (33 %), and 80 (54 %) cases, respectively. Follow-up ranged from 10 to 82 months (median: 57 months). Fifty-three (36 %) patients died of disease. There was an overall correlation of tumor thickness and grade in most of the cases. Low-grade tumors were encountered in 92 % (12/13 cases) of superficial tumors. Deep tumors showed high-grade in 75 % of cases (73/97 cases). Superficial tumors with low histological grade had negative inguinal nodes and no mortality whereas deep tumors showing high histological grade were associated with high metastatic risk to lymph nodes (62/73 cases) and mortality (52/73 cases). Out of 24 deep tumors with low histological grade, seven had nodal spread (29 %) but only one died of disease. No outcome difference was found in HPV associated vs HPV independent tumors. Tumor thickness and grade are important synergistic and predictive pathological factors in relation to prognosis.

Feasibility of anaerobic co-digestion of biodegradable plastics with food waste, investigation of microbial diversity and digestate phytotoxicity

The effects of biodegradable plastics of different thicknesses (30 and 40 μm) and sizes (20 × 20, 2 × 2, and 1 × 1 mm) on anaerobic digestion of food waste and digestate phytotoxicity were investigated. Methane productions (38 days) for the groups with 20 × 20, 2 × 2, and 1 × 1 mm of 30 μm plastics were 92.46, 138.27, and 259.95 mL/gVSremoval, respectively which are nearly 58 % higher than the control group (58.86 mL/gVSremoval). Methane production in 40 μm plastics groups was lower than in 30 μm groups of equal size. All sizes of 30 µm plastics promoted substrate hydrolysis, acidification, and relative abundance of key hydrolytic bacteria and methanogens. Phytotoxicity tests results showed that seed root elongation was inhibited in groups with 40 μm plastics. In conclusion, 30 μm biodegradable plastics were more suitable for anaerobic digestion with food waste than 40 μm.

Effect of tin concentrations on the elemental and optical properties of zinc oxide thin films

Pure zinc oxide and Sn-doped ZnO thin films were deposited on a pre-heated glass substrate from tin (II) chloride dihydrate (SnCl2.2H2O) and zinc acetate (Zn(CH3COO))2 precursors using spray pyrolysis technique. The doped films were achieved by adding various quantities of (SnCl2. 2H2O) precursor to the solution of zinc acetate in volume percent range of 0-10. Rutherford Backscattering Spectrometry (RBS) was used to characterise the prepared films to determine their thickness and elemental composition. To examine the films' optical characteristics, a UV spectrometer operating at room temperature and covering a wavelength range of 300-1100 nm was employed. The film's thickness and composition show that as the volume of Sn in the thin films increases, so does the film's thickness. With average transmittance values up to 70 %, all the films are quite transparent in the visible region of the electromagnetic spectrum and have a significant UV cut-off at roughly 380 nm. The reflectivity of Sn-doped ZnO films is seen to be independent of the volume of Sn in the films, and the reflectivity of the films diminishes as the wavelength increases. Sn-doped ZnO thin film has an optical band gap of 3.14-3.18 eV. The properties of the thin film produced make it suitable for solar energy collection and improve the efficiency of solar energy system, various optoelectronics devices and sensor.

The FEDBD plasma's quantitative investigation of skin parameters: Skin elasticity, thickness, density, tissue oxygenation, perfusion, and edema

This study used the FEDBD plasma device for skin rejuvenation in animal samples. There were two groups of six male Wistar rats. Before starting the treatment, immediately after the treatment, the fourth week, and the tenth week of follow-up, biometric tests were performed, including moisture level, evaporation from the skin surface, erythema and melanin, skin elasticity and firmness with an MPA9 device and cutometer. The thickness and density of the epidermis and dermis, an essential indicator in rejuvenation, were evaluated with a skin ultrasound device. Also, the level of oxygen, perfusion, and interstitial water (edema) was checked using a Tivita tissue hyperspectral camera at a depth of 6 mm of the skin.

Evaluating laser surface melting of NiCrAlY-APS coating and its effect on high-temperature oxidation behavior of NiCrAlY/YSZ thermal barrier coating before and after surface melting

This research study was conducted to investigate the laser melting parameters of NiCrAlY-APS coating. High-temperature oxidation was investigated using yttria partially stabilized zirconia (YSZ) ceramic coating. Also, the oxidation behavior of the TBC coating was investigated and studied before to and after laser surface melting of the NiCrAlY coating. Microstructural characterization was done using a scanning electron microscope (SEM), elemental analysis by energy dispersive spectroscopy (EDS), and phase analysis by X-ray diffraction (XRD). Surface melting was then performed in the power range of 150-300 W and scanning speed of 2-6 mm s-1. Surface melting was also conducted on the coating using two strategies: single-pass and multi-pass. The obtained results showed that the average melting depth and thickness reduction were directly related to the laser power, while they had an inverse relation with the laser scanning speed. Furthermore, multi-pass surface melting parameters reduced porosity to less than 0.1 %. Roughness measurements also showed a decrease in the coating's surface hardness after surface melting, as compared to the APS coating. The structure consisted of oriented columnar dendrites after melting the laser. The adhesion strength of the TBC coating and laser surface melting coating was at 41 MPa and 53 MPa, respectively. After 200 h of oxidation in the G1504 sample, the TGO layer's growth was decreased; due to the growth of a single oxide layer, it had better oxidation resistance in comparison to the other sample.

Evaluation of choroidal thickness and choroidal vascularity index in patients with Crimean-Congo hemorrhagic fever

PURPOSE

This study aimed to compare choroidal thickness parameters between patients diagnosed with Crimean-Congo hemorrhagic fever (CCHF) and healthy individuals using spectral domain optical coherence tomography.

METHODS

The right eyes of 27 individuals diagnosed with CCHF and 27 healthy subjects were included in this study. CCHF cases were assessed based on a history of tick bites and hospitalization. Choroidal thickness was measured using enhanced depth imaging optical coherence tomography. Measurements of choroidal thickness were taken at 5 different points, including the subfoveal quadrant and the fovea up to 2000 μm with 1000 μm intervals in the temporal and nasal quadrants. Choroidal vascular index (CVI) was calculated as the ratio of luminal area (LA) to total choroidal area (TCA) at the macula's total area and at 1500 μm from the center (CVI and CVI1500).

RESULTS

Choroidal thickness in the CCHF group was found to be thicker in each quadrant compared to the control group, with the subfoveal and nasal quadrants showing significantly greater thickness. TCA, stromal area, and LA were significantly higher in the CCHF group, while no significant difference was observed in CVI and CVI1500.

CONCLUSION

The findings of this study suggest that CCHF disease may have an impact on the choroidal structure.

DTV-CNN: Neural network based on depth and thickness views for efficient 3D shape classification

Fast and effective algorithms for deep learning on 3D shapes are keys to innovate mechanical and electronic engineering design workflow. In this paper, an efficient 3D shape to 2D images projection algorithm and a shallow 2.5D convolutional neural network architecture is proposed. A smaller convolutional neural network (CNN) model is achieved by information enrichment at the preprocessing stage, i.e. 3D geometry is compressed into 2D "thickness view" and "depth view". Fusing the depth view and thickness view (DTV) from the same projection view into a dual-channel grayscale image, can improve information locality for geometry and topology feature extraction. This approach bridges the gap between mature image deep learning technologies to the applications of 3D shape. Enhanced by several essential scalar geometry properties and only 3 projection views, a mixed CNN and multiple linear parameter (MLP) neural network model achives a validation accuracy of 92 % for ModelNet10 mesh-based dataset, while the training time is one order of magnitude less than the original multi-view CNN approach. This study also creates new 3D shape datasets from 2 open source CAD projects. Higher validation accuracy is obtained for realistic CAD datasets, i.e. 97 % for FreeCAD's mechanical part library and 95 % for KiCAD electronic part library. The training cost reduces to tens of minutes on a laptop CPU, given the smaller input data size and shallow neural network design. It is expected that this approach can be adapted for other machine learning scenarios involved in CAD geometry.

Comparison of the thickness of the erector spinae muscles between aspiration pneumonia and bacterial pneumonia patients

BACKGROUND AND AIMS

Aspiration pneumonia is generally associated with deterioration of skeletal muscle mass, which is usually evaluated by the erector spinae muscle cross-sectional area (ESMCSA); however, no report has assessed ESMCSA in patients with aspiration pneumonia. Furthermore, erector spinae muscle thickness (ESMT) was developed to be easier to measure than ESMCSA. Therefore, this study investigated the relationship between ESMT and ESMCSA in aspiration pneumonia patients compared to bacterial pneumonia patients.

METHODS

We retrospectively collected data for 164 patients with aspiration pneumonia and 480 patients with bacterial pneumonia who were hospitalized at Fukujuji Hospital between September 2018 and May 2022. We assessed the correlations between ESMCSA and ESMT and compared the data between the two groups.

RESULTS

ESMT had a strong, proportional relationship with ESMCSA in all patients (r = 0.908, p < 0.001) and those with aspiration pneumonia (r = 0.896, p < 0.001). ESMCSA (median 671.8 mm2 [range 164.0-1636.7] vs. median 1057.0 mm2 [range 161.3-2412.5], p < 0.001) and ESMT (median 17.1 mm [range 6.95-34.4] vs. median 23.8 mm [range 6.95-43.7], p < 0.001) were significantly lower in patients with aspiration pneumonia. A multivariate analysis of aspiration pneumonia diagnosis showed significant independent differences from bacterial pneumonia in ESMCSA (odds ratio 0.998 [95% CI: 0.996-0.999], p = 0.001) and ESMT (odds ratio 0.90 [95% CI: 0.84-0.96], p = 0.002).

CONCLUSION

This study demonstrates a strong correlation between ESMCSA and ESMT. ESMT can be more easily used to evaluate skeletal muscle mass and can help in diagnosing aspiration pneumonia.

Optical behavior of 3D-printed dental restorative resins: Influence of thickness and printing angle

OBJECTIVES

To evaluate the influence of thickness and printing angle on the optical properties of 3D-printed dental restorative resins.

METHODS

Four 3D printing resin systems were evaluated: DFT-Detax Freeprint Temp; FP- Formlabs Permanent Crown; FP- Formlabs Temporary CB; and GCT- GC Temporary-. Samples from each material were printed at 0° and 90°, and polished up to 0.5, 1.0, 1.5 and 2.0 mm thickness. Scattering (S), absorption (K) and albedo (a) coefficients, transmittance (T%), light reflectivity (RI) and infinite optical thickness (X∞) were calculated using Kubelka-Munk's model. Data were statistically analyzed using Kruskal-Wallis¸ Mann-Whitney tests, and VAF coefficient.

RESULTS

The spectral distribution on S, K, T%, RI,X∞ were wavelength dependent. Although the spectral behaviors were similar for all the specimens evaluated, the values of S, K, T% andX∞ presented significant differences between specimen thicknesses for all the materials used and for both printing orientations. Values for S and K increased, and T% and X∞ decreased. Significant differences between 0° and 90° were found for RI values at 0.5 and 1.0 mm thick samples, for S and K at 2.0 mm, for X∞ at 0.5 and 1.0 mm for DFT, and at 0.5 mm for FT.

CONCLUSIONS

Optical properties of 3D-printed restorative resins vary between thicknesses, and could be affected by the building orientation. Therefore, these factors should be considered in order to improve the biomimetic potential of 3D-printed dental restorative resins.

CLINICAL SIGNIFICANCE

Understanding the optical behavior of the 3D-printed restorative resins is essential to optimize their clinical performance.

Performance evaluation of ZnSnN2 solar cells with Si back surface field using SCAPS-1D: A theoretical study

The earth-abundant semiconductor zinc tin nitride (ZnSnN2) has garnered significant attention as a prospective material in photovoltaic and lighting applications, primarily due to its tunable narrow bandgap and high absorption coefficient. This study focuses on a numerical investigation of ZnSnN2 solar cell structures using the SCAPS 1-D software. The objective is to analyze the influence of various physical and geometrical parameters on solar cell performance. These parameters include the thicknesses of the ZnO window layer, CdS buffer layer, ZnSnN2 absorber layer, and Si back surface field layer (BSF), as well as operating temperature, series and shunt resistances (RS and Rsh), absorber layer defect density, interface defects, and the generation-recombination profile of the n-ZnO:Al/n-CdS/p-ZnSnN2/p-Si/Mo structure. We have evaluated the capabilities of this novel material absorber by investigating its performance across a range of thicknesses. We have started with ultrathin absorber thicknesses and gradually increased them to thicker levels to determine the optimal thickness for achieving high efficiency. Under optimal conditions, a thin solar cell with a thickness (wp) of 1 μm achieved an efficiency (η) of 23.9%. In a practical solar cell operating at room temperature, optimal parameters were observed with a thicker absorber layer (wp = 8 μm) and a BSF width of 0.3 μm. The cell exhibited resistances of Rsh = 106 Ω cm2 and Rs = 1 Ω cm2, along with a low defect density (Nt = 1010 cm-3) in the ZnSnN2 semiconductor. These factors combined to yield an impressive efficiency of 29.5%. Numerous studies on emerging ternary nitride semiconductors (Zn-IV-N2) have highlighted ZnSnN2 as a promising material for thin-film photovoltaics. This compound is appealing due to its abundance, non-toxicity, and cost-effectiveness. Unlike conventional solar cells that depend on rare, toxic, and costly elements, these components are still essential for today's solar cell technology.

Dosimetry characteristics of Epoxy/MWCNT nanocomposite in the field of gamma-rays: Effect of thickness

Polymer-carbon nanostructures have been used as gamma-ray dosimeters. The thickness of the sensitive volume material plays an important role in the determination of the dosimetry response. In this work, the thickness effect of a real-time dosimeter based on the Epoxy/Multi-walled carbon nanotube (MWCNT) nanocomposite was investigated. The amount of electrical percolation threshold (EPT) for Epoxy/MWCNT nanocomposite was initially simulated using the finite element method. Then, the 0.1 MWCNT wt% nanocomposite was fabricated using a solution method with three thicknesses of 1, 2, and 3 mm. FESEM images demonstrated a good dispersion state of the inclusions into the Epoxy matrix. The samples were irradiated by gamma-rays of Co-60 source over the dose rates of 25-166 mGy/min. In addition, dosimetric characteristics were performed, including linearity, bias-polarity, angular dependence, energy dependence, field size, and repeatability. Results revealed that with increasing the thickness, the dosimetry response was enhanced remarkably.

Dimensional distress and orbitofrontal thickness in anxiety patients

Thickness of the medial orbitofrontal cortex (mOFC) was assessed as it varied with reported symptoms of anxiety and depression in a large sample of anxiety patients. A principal component analysis identified a primary factor of transdiagnostic dimensional distress that predicted 24% of the mOFC variance. Severity of distress symptomology was associated with thinning of the mOFC in both hemispheres for both men and women, regardless of the primary DSM diagnosis. Taken together, the data indicate that mOFC thickness might be useful as an objective measure of disorder severity as well as to assess pharmacological or psychological treatment outcome.

Ultrasonographic echo intensity in the medial femoral cartilage is enhanced prior to cartilage thinning in women with early mild knee osteoarthritis

PURPOSE

We aimed to determine whether altered cartilage echo intensity is associated with knee osteoarthritis (OA) severity and whether the alteration occurs before thinning of the femoral cartilage in knee OA.

METHODS

The medial femoral cartilage thickness and echo intensity of 118 women aged ≥ 50 years were assessed using an ultrasound imaging device. Based on the Kellgren-Lawrence (KL) grade and knee symptoms, participants were classified into five groups: control (asymptomatic grades 0-1), early OA (symptomatic grade 1), grade 2, grade 3, and grade 4. Analysis of covariance, with adjusted age and height, and the Sidak post hoc test were used to assess the differences in cartilage thickness and echo intensity in knees with varying OA severity.

RESULTS

The echo intensity on longitudinal images, equivalent to the tibiofemoral weight-bearing surface, was significantly higher in the grade 2 group than that in the control group (p = 0.049). However, no significant difference was noted in cartilage thickness (n.s.). In the grades 3 and 4 groups, cartilage thickness became thinner as OA progressed (p < 0.001 and p < 0.001, respectively). However, the cartilage echo intensity was not significantly enhanced compared with that of the grade 2 group (n.s.). There were no significant differences in the cartilage thickness and echo intensity between the early OA and control groups on the longitudinal images (n.s.).

CONCLUSIONS

The echo intensity of the medial femoral cartilage was high in patients with KL grade 2, without decreased thickness. Our findings suggested that higher echo intensity is a feature of early cartilage degeneration in mild knee OA. Further studies are needed to establish this feature as a useful screening parameter of early cartilage degeneration in knee OA.

LEVEL OF EVIDENCE

Level III.

Influence of resistance training on muscle architecture in older adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Resistance training (RT) consists of planned exercise programs to increase muscle strength capacity through neural and structural adaptations, such as changes in the geometric arrangement of muscle fibers. This study aimed to analyze the influence of RT on muscle architecture in older people.

METHODS

This PROSPERO-registered systematic review and meta-analysis (identification number CRD42022340477) followed the PRISMA guidelines. Four electronic databases were searched for eligible randomized controlled trials (RCTs) that observed older individuals submitted to RT programs that reported muscle architecture outcomes.

RESULTS

Seventeen RCTs met the eligibility criteria with a total of 488 participants. The main results of the meta-analysis showed that RT interventions had a significant effect on the thickness of the medial gastrocnemius (SMD = 0.12; 95% CI: - 0.07 to 0.17; p < 0.00001; I2 = 0%).

CONCLUSION

Based on available evidence, studies included in this review showed improvement in maximum isometric force, pennation angle, fascicle length, thickness, and muscle activation after RT interventions. In turn, the meta-analysis suggested a potential for improving the thickness of the medial gastrocnemius after the intervention. However, any clinical implications drawn from the analyses should be interpreted with caution, as these findings are substantially limited due to a low number of included studies and a potential heterogeneity between studies.

Effects of thickness and polishing treatment on the translucency and opalescence of six dental CAD-CAM monolithic restorative materials: an in vitro study

BACKGROUND

Computer-aided design and computer-aided manufacturing (CAD-CAM) materials for prosthetic is gaining popularity in dentistry. However, limited information exists regarding the impact of thickness and roughening treatment on the optical properties of contemporary CAD-CAM restorative materials. This study aimed to quantitatively evaluate the translucency and opalescence of six dental CAD-CAM materials in response to different thicknesses and roughening treatments.

METHODS

Six dental CAD-CAM materials, lithium disilicate glass-ceramic (IPS e.max CAD, LS), polymer-infiltrated ceramic (VITA Enamic, VE), resin-nano ceramic glass-ceramic (LAVA Ultimate, LU), polymethyl methacrylate (Telio CAD, TE), and two zirconia reinforced lithium silicate (VITA Suprinity, VS, and Celtra Duo, CD), in shade A2 were prepared as 12 × 12mm2 specimens of four thicknesses (0.5mm, 1.0mm, 1.5mm, and 2.0mm) (N = 240, n = 10). After three different treatments (polished, roughened by SiC P800-grit, and SiC P300-grit), the translucency parameter (TP00) and opalescence parameter (OP) were measured with a spectrophotometer (VITA Easyshade V). The surface roughness was analyzed with a shape measurement laser microscope. The data were analyzed using a MANOVA, post hoc Tukey-Kramer test, the t test, and regression analysis (α = .05).

RESULTS

The TP00 and OP were significantly influenced by material type, thickness and roughening treatment (P < .05). TP00 showed a continues decline with increasing thicknesses, while the variations of OP were material-dependent. TP00 ranged from 37.80 (LS in 0.5mm) to 5.66 (VS in 2.0mm), and OP ranged from 5.66 (LU in 0.5mm) to 9.55 (VS in 0.5mm). The variations in TP00 of all materials between adjacent thicknesses ranged from 2.10 to 15.29, exceeding the acceptable translucency threshold except for LU. Quadratic and logarithmic regression curves exhibited the best fit for TP00 among the materials. Compared to polished specimens, rougher specimens exhibited lower TP00 and higher OP in all materials except for LS (P < 0.05). Roughening with P300-grit decreased TP00 and OP by an average of 2.59 and 0.43 for 0.5mm specimens, and 1.26 and 0.25 for 2.0mm specimens, respectively.

CONCLUSIONS

Variations in translucency caused by thickness and roughening treatment were perceptible and may be clinically unacceptable. Careful consideration should be given to the selection of CAD-CAM materials based on their distinct optical properties.

Neurodevelopmental risk and adaptation as a model for comorbidity among internalizing and externalizing disorders: genomics and cell-specific expression enriched morphometric study

BACKGROUND

Comorbidity is the rule rather than the exception for childhood and adolescent onset mental disorders, but we cannot predict its occurrence and do not know the neural mechanisms underlying comorbidity. We investigate if the effects of comorbid internalizing and externalizing disorders on anatomical differences represent a simple aggregate of the effects on each disorder and if these comorbidity-associated cortical surface differences relate to a distinct genetic underpinning.

METHODS

We studied the cortical surface area (SA) and thickness (CT) of 11,878 preadolescents (9-10 years) from the Adolescent Brain and Cognitive Development Study. Linear mixed models were implemented in comparative and association analyses among internalizing (dysthymia, major depressive disorder, disruptive mood dysregulation disorder, agoraphobia, panic disorder, specific phobia, separation anxiety disorder, social anxiety disorder, generalized anxiety disorder, post-traumatic stress disorder), externalizing (attention-deficit/hyperactivity disorder, oppositional defiant disorder, conduct disorder) diagnostic groups, a group with comorbidity of the two and a healthy control group. Genome-wide association analysis (GWAS) and cell type specificity analysis were performed on 4468 unrelated European participants from this cohort.

RESULTS

Smaller cortical surface area but higher thickness was noted across patient groups when compared to controls. Children with comorbid internalizing and externalizing disorders had more pronounced areal reduction than those without comorbidity, indicating an additive burden. In contrast, cortical thickness had a non-linear effect with comorbidity: the comorbid group had no significant CT differences, while those patient groups without comorbidity had significantly higher thickness compare to healthy controls. Distinct biological pathways were implicated in regional SA and CT differences. Specifically, CT differences were associated with immune-related processes implicating astrocytes and oligodendrocytes, while SA-related differences related mainly to inhibitory neurons.

CONCLUSION

The emergence of comorbidity across distinct clusters of psychopathology is unlikely to be due to a simple additive neurobiological effect alone. Distinct developmental risk moderated by immune-related adaptation processes, with unique genetic and cell-specific factors, may contribute to underlying SA and CT differences. Children with the highest risk but lowest resilience, both captured in their developmental morphometry, may develop a comorbid illness pattern.

C-Reactive protein and cognition: Mediation analyses with brain morphology in the UK Biobank

Cognitive impairments and abnormal immune activity are both associated with various clinical disorders. The association between C-Reactive protein (CRP), a marker associated with inflammation, and cognitive performance remains unclear. Further, mechanisms potentially linking CRP to cognition are not yet established. Brain structure may well mediate this relationship: immune processes play crucial roles in shaping and maintaining brain structure, with brain structure and function driving cognition. The United Kingdom Biobank (UKBB) is a large cohort study with extensive assessments, including high-sensitivity serum CRP levels, brain imaging, and various cognitive tasks. With data from 39,200 UKBB participants, we aimed first to determine the relationship between CRP and cognitive performance, and second, to assess metrics of brain morphology as potential mediators in this relationship. Participants were aged 40 to 70 at initial assessment and were mostly Caucasian. After accounting for potential covariates (e.g., age, sex, medical diagnoses, use of selective-serotonin reuptake inhibitors), we found CRP levels to have small, negative associations with fluid intelligence (b = -0.03, 95%CI[-0.05,-0.02], t(14381) = -3.62, p_cor = .004), and numeric memory (b = -0.03, 95%CI[-0.05,-0.01], t(14366) = -3.31, p_cor = .007). We found no evidence of brain morphology mediating these relationships (all |ab| < 0.001, all p_cor > .55). Our findings from this large sample suggest that serum-assessed CRP is of marginal importance for cognitive performance in mid-to-late aged Caucasians; the small effect sizes of statistically significant associations provide context to previous inconsistent results. The seeming lack of involvement of brain morphology suggests that other brain metrics (e.g., connectivity, functional activation) may be more pertinent to this relationship. Future work should also consider CRP levels measured in the central nervous system and/or other cytokines that may better predict cognitive performance in this population.

An automated, geometry-based method for hippocampal shape and thickness analysis

The hippocampus is one of the most studied neuroanatomical structures due to its involvement in attention, learning, and memory as well as its atrophy in ageing, neurological, and psychiatric diseases. Hippocampal shape changes, however, are complex and cannot be fully characterized by a single summary metric such as hippocampal volume as determined from MR images. In this work, we propose an automated, geometry-based approach for the unfolding, point-wise correspondence, and local analysis of hippocampal shape features such as thickness and curvature. Starting from an automated segmentation of hippocampal subfields, we create a 3D tetrahedral mesh model as well as a 3D intrinsic coordinate system of the hippocampal body. From this coordinate system, we derive local curvature and thickness estimates as well as a 2D sheet for hippocampal unfolding. We evaluate the performance of our algorithm with a series of experiments to quantify neurodegenerative changes in Mild Cognitive Impairment and Alzheimer's disease dementia. We find that hippocampal thickness estimates detect known differences between clinical groups and can determine the location of these effects on the hippocampal sheet. Further, thickness estimates improve classification of clinical groups and cognitively unimpaired controls when added as an additional predictor. Comparable results are obtained with different datasets and segmentation algorithms. Taken together, we replicate canonical findings on hippocampal volume/shape changes in dementia, extend them by gaining insight into their spatial localization on the hippocampal sheet, and provide additional, complementary information beyond traditional measures. We provide a new set of sensitive processing and analysis tools for the analysis of hippocampal geometry that allows comparisons across studies without relying on image registration or requiring manual intervention.

Cortical and subcortical brain morphometry abnormalities in youth at clinical high-risk for psychosis and individuals with early illness schizophrenia

Neuroimaging studies have documented morphometric brain abnormalities in schizophrenia, but less is known about them in individuals at clinical high-risk for psychosis (CHR-P), including how they compare with those observed in early schizophrenia (ESZ). Accordingly, we implemented multivariate profile analysis of regional morphometric profiles in CHR-P (n = 89), ESZ (n = 93) and healthy controls (HC; n = 122). ESZ profiles differed from HC and CHR-P profiles, including 1) cortical thickness: significant level reduction and regional non-parallelism reflecting widespread thinning, except for entorhinal and pericalcarine cortex, 2) basal ganglia volume: significant level increase and regional non-parallelism reflecting larger caudate and pallidum, and 3) ventricular volume: significant level increase with parallel regional profiles. CHR-P and ESZ cerebellar profiles showed significant non-parallelism with HC profiles. Regional profiles did not significantly differ between groups for cortical surface area or subcortical volume. Compared to CHR-P followed for ≥18 months without psychosis conversion (n = 31), CHR-P converters (n = 17) showed significant non-parallel ventricular volume expansion reflecting specific enlargement of lateral and inferolateral regions. Antipsychotic dosage in ESZ was significantly correlated with frontal cortical thinning. Results suggest that morphometric abnormalities in ESZ are not present in CHR-P, except for ventricular enlargement, which was evident in CHR-P who developed psychosis.

Influence of thickness and surface conditioning on fracture resistance of occlusal veneer

BACKGROUND

The purpose of the current study was to assess the impact of restoration thickness, surface conditioning and the interaction between them on the fracture resistance of CAD/CAM fabricated lithium disilicate occlusal veneers.

METHODS

A total of 42 maxillary molars were prepared to receive CAD/CAM fabricated lithium disilicate occlusal veneer either with 0.5 mm (n = 21) or 1 mm (n = 21) thickness. Each main group was divided into 3 subgroups (n = 7), according to surface treatment, HF acid (HF-1, HF-0.5), acidulated phosphate fluoride (APF-1, APF-0.5) and Monobond etch & prime (MON-1, MON-0.5). Multilinik N (Ivoclar-Vivadent) adhesive resin cement was used for bonding according to the manufacturer instructions. One hour after bonding, specimens were stored in water bath for 75 days followed by cyclic loading fatigue for 240,000 cycles to simulate clinical situation. Finally, specimens were fractured under compressive load in (N) using a universal testing machine. Two and one-way ANOVA and Post Hoc Tukey test were used for statistical analysis.

RESULTS

The means ± SD (N) fracture load for each group were calculated. MON-1 group showed the highest fracture load (1644.7 ± 155.3) followed by HF-1 group (1514.6 ± 212.5). Meanwhile, APF-0.5 showed the lowest fracture load (962 ± 249.6).

CONCLUSION

CAD/CAM fabricated lithium disilicate occlusal veneers can be used with a thickness of 0.5 mm instead of conventional crowns. Monobond etch & prime is recommended as a surface treatment for CAD/CAM fabricated lithium disilicate occlusal veneer due to biological hazards of Hydrofluoric acid.

Development and application of an optimal three-wavelength combination for liquid film measurement with absorption spectroscopy

In the simultaneous measurement of liquid film temperature and thickness based on multi-wavelength absorption spectroscopy, selecting optimal wavelength combinations can significantly improve the measurement accuracy. In the work, the absorption spectra of e-liquid at different temperatures were measured firstly. And ten sets of two-wavelength and three-wavelength combinations were then established based on five specific wavelengths from the absorption spectra, respectively. And the measurement accuracy of all the combinations were validated with a home-made calibration system. Among them, an optimal three-wavelength combination were selected. Finally, the evaporation processes of e-liquid films at three initial thicknesses (921/780/629 μm) on a horizontal quartz plate were then investigated with the optimal combination. The variation trends of film temperature and thickness measured by the combination were consistent with imaging method and thermocouple. It was found that the optimal three-wavelength combination could achieve high accuracy in simultaneous measurement of liquid film temperature and thickness.

Statistical analysis of the thickness and biomechanical properties of Japanese children's skulls

OBJECTIVE

The structure and strength of a child's skull are important in accurately determining what and how external forces were applied when examining head injuries. The aims of this study were to measure skull thickness and strength in children, evaluate sex differences, and investigate the correlation between skull thickness and strength and age.

MATERIALS AND METHODS

Skulls were obtained from 42 Japanese dead bodies under 20 years of age. During the autopsies, bone samples were taken from each skull. The length, width, and central thickness of the skulls were measured using calipers. Three-point bending tests were conducted, and bending load and displacement were recorded. Bending stress and bending strain were calculated, and Young's modulus, 0.2% proof stress, and maximum stress were obtained.

RESULTS

In cases under 1.5 years old, 14 out of 46 male samples and 20 out of 40 female samples did not fracture during the three-point bending test, though no significant sex differences were detected. No significant differences in age, sample thickness, Young's modulus, 0.2% proof stress, or maximum stress were detected between the sexes. The sample thickness, Young's modulus, 0.2% proof stress, and maximum stress increased significantly and logarithmically with age (R² = 0.761-0.899). Although age correlated with thickness, Young's modulus, and maximum stress more in females than in males, 0.2% proof stress correlated slightly better in males than in females.

CONCLUSION

The skulls of preschool children, in particular, are thin, have low strength, and are at high risk of fracturing even with relatively small external forces. Unlike adults, no significant sex differences in skull thickness or strength were observed in children.

Assessment of mouthguards worn by Irish children playing contact sports: an observational cross-sectional cohort study

PURPOSE

Traumatic dental injuries occur during participation in sports. Prevention of these injuries by wearing a mouthguard (MG) is desirable, especially in a paediatric population. There are several types of MG available, and their effectiveness depends on device design. The aim of this study was to examine the features of MG worn by children playing a contact sport (Gaelic football), and to determine whether these MG fulfilled recommendations for adequate dentoalveolar protection.

METHODS

A cross-sectional observational cohort study design was developed. Dentists were trained and calibrated in assessing MGs, both qualitatively (retention, extension, integrity) and quantitatively (thickness). A convenience sample of male and female subjects aged 9-16 years was selected for MG assessment via their sports clubs. Data were collected anonymously and analysed using descriptive and comparative statistics.

RESULTS

One hundred and six children presented with their MG for assessment. Two-thirds were wearing mouth-formed MG (N = 71, 66.96%). Only four were wearing custom MG (3.77%). Most MG had inadequate retention (N = 86, 81.13%) and labial extension (N = 89, 83.96%), with a significant relationship between MG type and retention. Mouthguard thickness varied widely at each site. Mouth-formed MG were significantly thicker than both stock and custom MG.

CONCLUSIONS

Mouth-formed MG were the most common type followed by stock MG. Most MG did not have appropriate retention or labial extension. Parents and coaches need to be aware of MG features that maximise protection. If mouth-formed MG are provided in this age group, education on how to adapt them is essential. Paediatric dentists should check MG routinely for appropriate fit.

The impact of lipid polyunsaturation on the physical and mechanical properties of lipid membranes

The lipid composition of cellular membranes and the balance between the different lipid components can be impacted by aging, certain pathologies, specific diets and other factors. This is the case in a subgroup of individuals with psychiatric disorders, such as schizophrenia, where cell membranes of patients have been shown to be deprived in polyunsaturated fatty acids (PUFAs), not only in brain areas where the target receptors are expressed but also in peripheral tissues. This PUFA deprivation thus represents a biomarker of such disorders that might impact not only the interaction of antipsychotic medications with these membranes but also the activation and signaling of the targeted receptors embedded in the lipid membrane. Therefore, it is crucial to understand how PUFAs levels alterations modulate the different physical properties of membranes. In this paper, several biophysical approaches were combined (Laurdan fluorescence spectroscopy, atomic force microscopy, differential scanning calorimetry, molecular modeling) to characterize membrane properties such as fluidity, elasticity and thickness in PUFA-enriched cell membranes and lipid model systems reflecting the PUFA imbalance observed in some diseases. The impact of both the number of unsaturations and their position along the chain on the above properties was investigated. Briefly, data revealed that PUFA presence in membranes increases membrane fluidity, elasticity and flexibility and decreases its thickness and order parameter. Both the level of unsaturation and their position affect these membrane properties.

Effect of precursor concentration on stoichiometry and optical properties of spray pyrolyzed nanostructured NiO thin films

In this study, spray pyrolysis was used to produce nanostructured NiO thin films from high purity nickel acetate (Ni(CH₃COO)₂.3H₂O) precursors on pre-heated ultrasonically cleaned soda-lime glass substrates. The metallic constituent concentrations in the films were varied, and the precursors were produced in distilled water at various molarities ranging from 0.1 to 0.4 M. In the study, the field-emission scanning electron microscope (FESEM) results strongly confirmed adherence of the films to the glass substrate at 350 °C. The presence of Ni and O in the samples was confirmed using Rutherford backscattering spectroscopy (RBS), X-ray diffractometry (XRD) and energy dispersive X-ray spectroscopy (EDX). For the 0.1 M NiO thin films, the thickness was approximately 43 nm, and for the 0.2 M, 0.3 M, and 0.4 M films, the thickness was 46 nm, 47 nm, and 49 nm, respectively. The XRD findings were supported by the increased Raman intensity peaks with increased precursor concentration, which confirmed the films' improved crystallinity. For the same number of passes of films deposition, as the molar concentration increases, the films thickness increases. The amount of nickel in NiO thin films increases as the molarity increases, but the amount of oxygen in NiO thin films decreases as the molarity increases. It was discovered that as molarity increases, the optical transmittance decreases and the optical band gap narrows. The qualities of NiO discovered in this study suggest the films' potentials for usage as window layer and buffer material in thin film solar cells.

Thicker polyethylene inserts (≥ 13 mm) increase the risk for early failure after primary cruciate-retaining total knee arthroplasty (TKA): a single-centre study of 7643 TKAs

PURPOSE

This study investigates whether thicker (PE) inserts lead to a greater risk for revision after TKA. The differences between the TKA designs of three manufacturers (NexGen, PFC Sigma, Triathlon) are also compared.

METHODS

A total of 7643 primary TKA surgeries were included. PE inserts were divided into two groups-"thick PE inserts" with a thickness of 13 mm (mm) or more and "standard PE inserts" with a thickness of less than 13 mm. Three cruciate-retaining (CR) TKA designs (NexGen, PFC Sigma, Triathlon) were included in the study. The differences in failure rates between groups were investigated using Kaplan-Meier survival curves and Cox regression model with hazard ratios (HR). Failure rates were investigated short-term (< 2 years) and long-term (the whole follow-up period). The TKA designs were analysed both together and separately.

RESULTS

During the whole follow-up period, there were 184 (2.4%) aseptic revisions. The thick PE insert group showed an increased risk for revision compared to the standard PE insert group in both short-term (< 2 years; HR 2.0, CI 1.3 to 3.2) and long term (> 2 years; HR 1.6, CI 1.1 to 2.3) follow-up. The highest revision rate was observed in patients who received the Triathlon TKA with a thicker PE insert (HR 2.6, CI 1.2 to 5.7).

CONCLUSION

The results indicate that thicker PE inserts are associated with increased risk for revision in primary TKA. Further research is required to ascertain whether more conformed PE inserts or constrained knee designs instead of thick CR inserts will ultimately lead to better clinical outcomes.

LEVEL OF EVIDENCE

III.

Stiffness and thickness of the upper trapezius muscle increase after repeated climbing bouts in male climbers

Background

Indoor climbing involves overloading the shoulder girdle, including the rotator cuff and upper trapezius muscles. This on the field study aimed to investigate the effects of repeated climbing bouts on morphological and mechanical measures of the upper trapezius muscle.

Materials and Methods

Fifteen experienced male climbers participated in the study. Rate of perceived exertion (RPE), blood lactate concentration ([La^-]_b), and stiffness and thickness over four points of the upper trapezius were assessed before and after a repeated climbing exercise. The procedure for the climbing exercise consisted of five climbs for a total time of 5-minutes per climb, followed by a 5-minute rest.

Results

The analysis showed an increase from baseline to after the 3rd climb (p ≤ 0.01) for RPE and after the 5th climb for [La^-]_b (p ≤ 0.001). Muscle stiffness and thickness increased at all points (1-2-3-4) after the 5th climb (p ≤ 0.01). We found spatial heterogeneity in muscle stiffness and thickness; muscle stiffness was the highest at Point 4 (p ≤ 0.01), while muscle thickness reached the highest values at points 1-2 (both p ≤ 0.01). Moreover, the analysis between the dominant and non-dominant shoulder showed greater stiffness after the 1^st climb at Point 1 (p = 0.004) and after the 5^th climb at Point 4 (p ≤ 0.001).

Conclusions

For muscle thickness, the analysis showed significant changes in time and location between the dominant and the non-dominant shoulder. Bilateral increases in upper trapezius muscle stiffness and thickness, with simultaneous increases in RPE and blood lactate in response to consecutive climbs eliciting fatigue.

Comparative analysis of very volatile organic compounds and odors released from decorative medium density fiberboard using gas chromatography-mass spectrometry and olfactory detection

VVOCs with a retention range below C₆ have become one of the main indoor pollutants that negatively affect human health. Most studies have focused on the emission of VOCs from furniture and decorative materials, seldom consider VVOCs. To close this gap, a 15-L environmental chamber, combined with multi-absorbent tube, was used for gas sampling. Emissions of VVOCs and odors released from decorative medium density fiberboard (MDF) were measured using gas chromatography-mass spectrometry and olfactometry detection. The results demonstrated that multi-absorbent tubes had excellent capture capacity for low-molecular-weight VVOCs. Thickness and decorative materials had conspicuous effects on VVOCs and odor emissions. The total VVOCs (TVVOC) from 18-mm decorative MDF was consistently higher than that of 8-mm samples. The major VVOCs from these decorative MDF were alcohols, esters and ketones, which were the major odor contributors with high odor intensity values. VVOCs concentration generally increased as thickness increased, but it decreased after decorative treatment. Fruity and alcohol-like were the main odor impressions of 8-mm MDF, whereas sweet and fruity were the major odor impressions of 8-mm polyvinyl chloride decorative MDF (PVC-MDF) and melamine impregnated paper decorative MDF (MI-MDF). Fruity was the main odor impression of 18-mm decorative MDF. The overall odor intensity increased and the major odor impression may differ when thickness was changed. Both the MI and the PVC decorative materials blocked some odor emissions but did so to a greater extent with the former than with the latter. Identification and analysis of the composition of VVOCs can supplement a database structure network of volatile pollutants and establish a novel and feasible method to investigate low-molecular-weight substances from wooden materials and their products.

Bending modulus of the rippled graphene: the role of thickness

Bending modulus is a key parameter to characterize the stiffness of materials. Commonly, it is believed that the bending modulus is closely related to the thickness as described by the thin plate theory. However, the thin plate theory fails in multilayer van der Waals materials like multilayer graphene, suggesting a more complex relationship between the bending modulus and thickness. Here, rippled graphene structures containing non-hexagonal carbon rings with different thicknesses are constructed to study the thickness-dependent bending modulus by the first-principles calculations. It is found that the bending modulus of rippled graphene depends on several factors, such as geometry, bending curvature, and thickness. Particularly, for the egg-tray graphene structures with similar structural pattern and bending curvature, i.e., eliminating the effects of structural pattern and bending curvature, the bending modulus could show a linear relationship to the thickness. Moreover, this linear relationship is very robust even in the case of changing the thickness through heteroatom doping.

Solar-Driven Photocatalytic Films: Synthesis Approaches, Factors Affecting Environmental Activity, and Characterization Features

Solar-powered photocatalysis has come a long way since its humble beginnings in the 1990s, producing more than a thousand research papers per year over the past decade. In this review, immobilized photocatalysts operating under sunlight are highlighted. First, a literature review of solar-driven films is presented, along with some fundamental operational differences in relation to reactions involving suspended nanoparticles. Common strategies for achieving sunlight activity from films are then described, including doping, surface grafting, semiconductor coupling, and defect engineering. Synthetic routes to fabricate photocatalytically active films are briefly reviewed, followed by the important factors that determine solar photocatalysis efficiency, such as film thickness and structure. Finally, some important and specific characterization methods for films are described. This review shows that there are two main challenges in the study of photocatalytic materials in the form of (thin) films. First, the production of stable and efficient solar-driven films is still a challenge that requires an integrated approach from synthesis to characterization. The second is the difficulty in properly characterizing films. In any case, the research community needs to address these, as solar-driven photocatalytic films represent a viable option for sustainable air and water purification.

Anatomical Variation in Diaphragm Thickness Assessed with Ultrasound in Healthy Volunteers

Ultrasonography of the diaphragm in the zone of apposition has become increasingly popular to evaluate muscle thickness and thickening fraction. However, measurements in this anatomical location are frequently hindered by factors that constrain physical accessibility or that alter diaphragm position. Therefore, other anatomical positions at the chest wall for transducer placement are used, but the variability in diaphragm thickness across the dome has not been systematically studied. The aim of this study was to evaluate anatomical variation of diaphragm thickness in 46 healthy volunteers on three ventrodorsal lines and two craniocaudal positions on these three lines. The intraclass correlation coefficient (ICC) for diaphragm thickness in the craniocaudal direction on the mid-axillary line was significantly higher than those on the posterior axillary and midclavicular lines, suggesting it had the lowest variability (ICC_midaxillary = .89, 95% confidence interval [CI]: 0.83-0.93, ICC_{posterior axillary} = 0.74, 95% CI: 0.62-0.85, ICC_{midclavicular} = 0.62, 95% CI: 0.43-0.47, p < 0.05). Average diaphragm thickness was comparable on the posterior axillary and midaxillary lines and substantially larger on the midclavicular line (1.24 mm [1.06-1.47], 1.27 mm [1.10-1.42] and 2.32 [1.97-2.70], p < 0.01). We conclude that the normal diaphragm has a large variability in thickness, especially in the ventrodorsal direction. Variability in craniocaudal position is the lowest at the midaxillary line, which therefore appears to be the preferred site for diaphragm thickness measurement.

Peripapillary structural and microvascular alterations in early dysthyroid optic neuropathy

Background

To explore the changes in blood supply and structure around the optic nerve head (ONH) in thyroid-associated ophthalmopathy (TAO) patients with suspected dysthyroid optic neuropathy (DON).

Methods

TAO patients [19 with DON; 24 non-DON (NDON); 20 with equivocal DON (EDON)], and 34 control subjects were examined. Optical coherence tomography angiography (OCTA) was used to obtain peripapillary retinal nerve fiber layer (p-RNFL) and vessel density parameters, including the ONH whole image vessel density (ONH-wiVD) and the radial peripapillary capillary vessel density (RPC-VD) in early DON.

Results

Although there were no differences in p-RNFL thickness among the groups, there were differences in the ONH-wiVD of each grid section and the RPC-VD in all areas (P < 0.01). Compared with healthy controls, the EDON eyes had significantly lower RPC-VDs in all aeras (P < 0.05).The peripapillary region was further divided into eight sectors, and the RPC-VD in the temporal upper, superior temporal, and temporal lower sectors in the EDON group were significantly lower than in the controls. The visual impairment was closely related to the loss of peripapillary capillary vessel density. Univariate correlation analysis showed that the ONH-wiVD and RPC-VD of the TAO groups were negatively correlated with the intraocular pressure (r = − 0.296, P = 0.006; r = − 0.258, P = 0.016 respectively).

Conclusions

EDON patients had significantly lower ONH-wiVD and RPC-VD than control subjects, and the temporal and upper VDs were more likely to be affected in the early stage of TAO. The combined use of spectral domain optical coherence tomography and OCTA technologies offer a new method for early diagnosis of suspected DON patients.

Optical coherence tomography reveals retinal thinning in schizophrenia spectrum disorders

BACKGROUND

Schizophrenia spectrum disorders (SSDs) are presumed to be associated with retinal thinning. However, evidence is lacking as to whether these retinal alterations reflect a disease-specific process or are rather a consequence of comorbid diseases or concomitant microvascular impairment.

METHODS

The study included 126 eyes of 65 patients with SSDs and 143 eyes of 72 healthy controls. We examined macula and optic disc measures by optical coherence tomography (OCT) and OCT angiography (OCT-A). Additive mixed models were used to assess the impact of SSDs on retinal thickness and perfusion and to explore the association of retinal and clinical disease-related parameters by controlling for several ocular and systemic covariates (age, sex, spherical equivalent, intraocular pressure, body mass index, diabetes, hypertension, smoking status, and OCT signal strength).

RESULTS

OCT revealed significantly lower parafoveal macular, macular ganglion cell-inner plexiform layer (GCIPL), and macular retinal nerve fiber layer (RNFL) thickness and thinner mean and superior peripapillary RNFL in SSDs. In contrast, the applied OCT-A investigations, which included macular and peripapillary perfusion density, macular vessel density, and size of the foveal avascular zone, did not reveal any significant between-group differences. Finally, a longer duration of illness and higher chlorpromazine equivalent doses were associated with lower parafoveal macular and macular RNFL thickness.

CONCLUSIONS

This study strengthens the evidence for disease-related retinal thinning in SSDs.

History of suicide attempts associated with the thinning right superior temporal gyrus among individuals with schizophrenia

Individuals with schizophrenia have higher rates of suicide attempts than the general population. Specific cortical abnormalities (e.g., the cortical surface area and thickness) may be associated with a history of suicide attempts. We recruited 74 individuals with schizophrenia (37 suicide attempters were individually matched with 37 non-attempters on age, sex, phase of illness, and study center) and 37 healthy volunteers. The cortical surface area and thickness data were extracted from structural MRI and compared between the groups. Suicide attempters showed significantly smaller surface areas in the whole brain (p = .028, Cohen's d = -0.54) than non-attempters. No association was found between the cortical surface area of individual brain regions and a history of suicide attempts. The mean cortical thickness did not differ significantly between the groups; however, suicide attempters demonstrated a thinner cortex in the right superior temporal gyrus (p < .001, q = 0.037, Cohen's d = -0.88). These findings indicate that a history of suicide attempts among individuals with schizophrenia is associated with a reduction in the global cortical surface area and specific cortical thinning of the right superior temporal gyrus. The morphometric alteration of the right superior temporal gyrus may represent a biomarker of suicidal behavior in individuals with schizophrenia.

Design of a CH3NH3PbI3/CsPbI3-based bilayer solar cell using device simulation

With lead-based light harvesters, perovskite solar cells (PSCs) have an efficiency of approximately 25.5%, making them a viable photovoltaic technology. The selection of the absorber materials for PSC in this work are (i) Cesium lead iodide (CsPbI₃) with a 1.73eV bandgap as the first absorber layer, this halide imparts higher stability to perovskite solar cells (ii) CH₃NH₃PbI₃ (MAPbI₃) with a bandgap of 1.55eV is selected as the second absorber layer as this material provides better efficiency to the perovskite solar cells. SCAPS-1D simulation software is used to perform an efficiency analysis of perovskite-perovskite CsPbI₃/MAPbI₃ bilayer solar cell. For efficiency optimization of the perovskite-perovskite bilayer solar cell, we have tried to calibrate seven parameters of the cell. These parameters are (i & ii) selection of the electron and hole transport material (iii, iv & v) variation in the: defect density of bulk material, doping concentration and the thickness of absorber layers, (vi) variation in work function of front electrode (vii) varying interface defect density. After optimization, the efficiency (η) of bilayer PSC is estimated to be 33.54%. The other PV parameters observed in optimal efficiency condition are open-circuit voltage (V_OC) = 1.34V, short-circuit current density (J_SC) = 27.45 mA/cm² and fill factor (FF) = 90.49%. The CsPbI₃/MAPbI₃ bilayer perovskite solar cell efficiency is roughly double the efficiency of single junction CsPbI₃ or MAPbI₃ PSC. Our analysis observed that the variation in the doping and defect density of narrow bandgap material profoundly impacts the efficiency of perovskite-perovskite bilayer solar cells compared to the wide bandgap material.

Surface protection method for the magnetic core using covalent organic framework shells and its application in As(III) depth removal from acid wastewater

Fe₃O₄-based materials are widely used for magnetic separation from wastewater. However, they often suffer from Fe-leaching behavior under acidic conditions, decreasing their activity and limiting sustainable practical applications. In this study, covalent organic frameworks (COFs) were used as the shell to protect the Fe₃O₄ core, and the Fe₃O₄@COF core-shell composites were synthesized for As(III) removal from acid wastewater. The imine-linked COFs can in situ grow on the surface of the Fe₃O₄ core layer by layer with [COFs/Fe₃O₄]_mol ratio of up to 2:1. The Fe-leaching behavior was weakened over a wide pH range of 1-13. Moreover, such composites keep their magnetic characteristic, making them favorable for nanomaterial separation. As(III) batch adsorption experiments results indicated that, when COFs are used as the shell for the Fe₃O₄ core, a balance between As(III) removal efficiencies and the thickness of the COF shell exists. Higher As(III) removal efficiencies are obtained when the [COFs/Fe₃O₄]_mol ratios were < 1.5:1, but thicker COF shells were not beneficial for As(III) removal. Such composites also exhibited better As(III) removal performances in the pH range of 1-7. Over a wide pH range, the zeta potential of Fe₃O₄@COF core-shell composites becomes more positive, which benefits the capture of negative arsenic ions. In addition, thinner surface COFs were favorable for mass transfer and facilitating the reaction of Fe and As elements. Our study highlights the promise of using COFs in nanomaterial surface protection and achieving As(III) depth removal under acidic conditions.

Integrity of the hip capsule measured with magnetic resonance imaging after capsular repair or unrepaired capsulotomy in hip arthroscopy

BACKGROUND

Current literature shows no clear answer on the question how to manage the capsule after hip arthroscopy. Regarding patient reported outcome measures there seems to be no difference between capsular repair or unrepaired capsulotomy.

AIM

To evaluate and compare the integrity of the hip capsule measured on a magnetic resonance imaging (MRI) scan after capsular repair or unrepaired capsulotomy.

METHODS

A case series study was performed; a random sample of patients included in a trial comparing capsular repair vs unrepaired capsulotomy had a postoperative MRI scan. The presence of a capsular defect and gap size were independently evaluated on MRI.

RESULTS

A total of 28 patients (29 hips) were included. Patient demographics were comparable between treatment groups. There were 2 capsular defects in the capsular repair group and 7 capsular defects in the unrepaired capsulotomy group (P = 0.13). In the group of patients with a defect, median gap sizes at the acetabular side were 5.9 mm (range: 2.7-9.0) in the repaired and 8.0 mm (range: 4.5-18.0) in the unrepaired group (P = 0.462). At the muscular side gap sizes were 6.6 mm (range: 4.1-9.0) in the repaired group and 11.5 mm (range: 3.0-18.0) in the unrepaired group (P = 0.857). The calculated Odds ratio (OR) for having a capsular defect with an increasing lateral center-edge (CE) angle was 1.12 (P = 0.06). The OR for having a capsular defect is lower in the group of patients that underwent a labral repair with an OR of 0.1 (P = 0.05).

CONCLUSION

There is no significant difference in capsular defects between capsular repair or unrepaired capsulotomy. Regarding clinical characteristics our case series shows that a larger CE angle increases the likelihood of a capsular defect and the presence of a labral repair decreases the likelihood of a capsular defect.

Effect of thickness on color appearance of multilayer CAD/CAM composite resin blocks

The aim of this study was to evaluate the effect of thickness on the color appearance and translucency parameter (TP) of multilayer CAD/CAM composite resin blocks. Four brands of A3-shade multilayer CAD/CAM composite resin blocks were examined (Katana Avencia, CERASMART Multi, KZR-CAD HR Block 4 E-va, and Block HC Hard AN). Six specimens of five thicknesses were prepared for each brand, yielding 120 specimens in total. CIEL*a*b* values were determined using a spectrophotometer against black and white backgrounds, and the TP was calculated. The color differences (ΔE₀₀) between layers (cervical/middle/incisal) and brands for each thickness against the black background were calculated using the CIEDE2000 system. As a result, on the black background, L* of the incisal layer was greater while a* and b* were smaller than those of the cervical layer for all brands. The ΔE₀₀ values between the cervical and middle layers (1.23-3.27) were smaller than those between the cervical and incisal layers (3.98-5.67) and those between the middle and incisal layers (3.14-5.92). TP decreased with increasing block thickness. Some TP differences between layers were significant, but they were less than 2.75. In conclusion, the color appearance of CAD/CAM blocks was significantly influenced by both the thickness and layer. L*a*b* decreased with thickness, and a negative exponential relationship between TP and thickness was observed for all layers and brands.

Acoustic properties across the human skull

Transcranial ultrasound is emerging as a noninvasive tool for targeted treatments of brain disorders. Transcranial ultrasound has been used for remotely mediated surgeries, transient opening of the blood-brain barrier, local drug delivery, and neuromodulation. However, all applications have been limited by the severe attenuation and phase distortion of ultrasound by the skull. Here, we characterized the dependence of the aberrations on specific anatomical segments of the skull. In particular, we measured ultrasound propagation properties throughout the perimeter of intact human skulls at 500 kHz. We found that the parietal bone provides substantially higher transmission (average pressure transmission 31 ± 7%) and smaller phase distortion (242 ± 44 degrees) than frontal (13 ± 2%, 425 ± 47 degrees) and occipital bone regions (16 ± 4%, 416 ± 35 degrees). In addition, we found that across skull regions, transmission strongly anti-correlated (R=-0.79) and phase distortion correlated (R=0.85) with skull thickness. This information guides the design, positioning, and skull correction functionality of next-generation devices for effective, safe, and reproducible transcranial focused ultrasound therapies.

Gravity measurement to probe the depth of African-continental crust over a north-south profile: theory and modeling

Based upon gravity measurements and calculations, the depth of the African continental crust is estimated. Taking as constraints the mass and radius of earth, and measured gravity, this theoretical method explores the use of gravitational potential to calculate the absolute gravity at three locations in Africa (e.g., Cape Town at latitude -34^o, central Africa at latitude 0, and Benghazi at latitude 32^o). The computational method uses as input a continental crust density ρ₁ = 2.65-2.75 g/cm³ while compromising the oceanic crust density ρ₂ to maintain the average crust density of the planet fixed at <ρ₁₂> = 2.60 g/cm³. Crustal depth is assumed uniform around the earth and kept as a free parameter to adjust for the best fitting of gravity but using values of less than 100 km. A solid angle α_o is a solid angle whose vertex is at the center of earth used to separate continental and oceanic crusts (α_o = 10^o, 20^o, 35^o). The results obtained for the continental crust were H = 36 km near continental edges at both Benghazi and Cape Town, whereas H = 44.4 km at the center of continent. These results are in excellent agreement with those reported by Tedla and coworkers (H = 39 ± 5 km) using an Euler deconvolution method. Our theoretical results from the developed code are also corroborated by results of numerical forward modeling supporting our code's reliability for further geoscience explorations.