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Background: Three-dimensional weightbearing CT (WBCT) has been widely used to assess foot and ankle alignment. However, most current measurement methods are based on 2-dimensional concepts—distance, long axis, angulation, etc—and are sensitive to changes in orientation of the WBCT images. This study demonstrated how changes in positioning of the image can significantly influence the evaluation of hindfoot alignment. Methods: WBCT scans of 10 feet without deformities were used. In the horizontal view, the long axis of the foot image was aligned to a neutral position and then rotated 5, 10, 15, and 20 degrees both internally and externally to simulate malposition. The Calcaneal Moment Arm (CMA) was measured by 2 investigators independently in the above positions. An intraclass correlation coefficient (ICC) model was used to assess the intra- and interobserver reliabilities. The correlation between the CMA and the rotation angle of the foot images was analyzed using linear regression. Results: The CMA measurements demonstrated that internal rotation of the image changed the neutral hindfoot into valgus, whereas external rotation led to varus. A 1-degree internal or external rotation of the image correlated with 0.48 (±0.03) mm increase or decrease in the modified WBCT-CMA value (P <.0001, R 2 = 0.6406). Conclusion: This study demonstrated that although 3D WBCT provides the ability to observe the foot from different perspectives, current alignment evaluation tools are limited to 2 dimensions. Therefore, positioning the WBCT images in a consistent orientation is important to generate correct data. [ABSTRACT FROM AUTHOR]

Automated segmentation of 3-dimensional pulp space on cone-beam computed tomography images presents a significant opportunity for enhancing diagnosis, treatment planning, and clinical education in endodontics. The aim of this systematic review was to investigate the performance of artificial intelligence-driven automated pulp space segmentation on cone-beam computed tomography images. A comprehensive electronic search was performed using PubMed, Web of Science, and Cochrane databases, up until February 2024. Two independent reviewers participated in the selection of studies, data extraction, and evaluation of the included studies. Any disagreements were resolved by a third reviewer. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to assess the risk of bias. Thirteen studies that met the eligibility criteria were included. Most studies demonstrated high accuracy in their respective segmentation methods, although there was some variation across different structures (pulp chamber, root canal) and tooth types (single-rooted, multirooted). Automated segmentation showed slightly superior performance for segmenting the pulp chamber compared to the root canal and single-rooted teeth compared to multi-rooted ones. Furthermore, the second mesiobuccal (MB2) canalsegmentation also demonstrated high performance. In terms of time efficiency, the minimum time required for segmentation was 13 seconds. Artificial intelligence-driven models demonstrated outstanding performance in pulp space segmentation. Nevertheless, these findings warrant careful interpretation, and their generalizability is limited due to the potential risk and low evidence level arising from inadequately detailed methodologies and inconsistent assessment techniques. In addition, there is room for further improvement, specifically for root canal segmentation and testing of artificial intelligence performance in artifact-induced images. [ABSTRACT FROM AUTHOR]

Three-dimensional printing (3DP) is being integrated into surgical practice at a significant pace, from preprocedural planning to procedure simulation. 3DP is especially useful in surgical education, where printed models are highly accurate and customizable. The aim of this study was to evaluate how 3DP is being integrated most recently into surgical residency training. We performed a structured literature search of the OVID/MEDLINE, EMBASE, and PUBMED databases following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Articles published from 2016 to 2023 that met predefined inclusion and exclusion criteria were included. Data extracted included surgical subspecialty using 3DP, application of 3DP, and any reported satisfaction measures of trainees. A thorough analysis of pooled data was performed to evaluate satisfaction rates among studies. A total of 85 studies were included. The median number of participants was 18 (interquartile range 10-27). Fourteen surgical disciplines were represented, with ear, nose, and throat/otolaryngology having the highest recorded utilization of 3DP models among residents and medical students (22.0%), followed by neurosurgery (14.0%) and urology (12.0%). 3DP models were created most frequently to model soft tissue (35.3%), bone (24.7%), vessel (14.1%), mixed (16.4%), or whole organs (6.66%) (Fig.1). Feedback from trainees was overwhelmingly positive regarding the fidelity of the models and their support for integration into their training programs. Among trainees, the combined satisfaction rate with their use in the curriculum was 95% (95% confidence interval, 0.92-0.97), and the satisfaction rate with the model fidelity was 90% (95% confidence interval, 0.86-0.94). There is wide variation in the surgical specialties utilizing 3DP models in training. These models are effective in increasing trainee comfort with both common and rare scenarios and are associated with a high degree of resident support and satisfaction. Plastic surgery programs may benefit from the integration of this technology, potentially strengthening future surgical curricula. Objective evaluations of their pedagogic effects on residents are areas of future research. [ABSTRACT FROM AUTHOR]

The increasing application of virtual surgical planning (VSP) in orthognathic surgery implies a critical need for accurate prediction of facial and skeletal shapes. The craniofacial relationship in patients with dentofacial deformities is still not understood, and transformations between facial and skeletal shapes remain a challenging task due to intricate anatomical structures and nonlinear relationships between the facial soft tissue and bones. In this study, a novel bidirectional 3-dimensional (3D) deep learning framework, named P2P-ConvGC, was developed and validated based on a large-scale data set for accurate subject-specific transformations between facial and skeletal shapes. Specifically, the 2-stage point-sampling strategy was used to generate multiple nonoverlapping point subsets to represent high-resolution facial and skeletal shapes. Facial and skeletal point subsets were separately input into the prediction system to predict the corresponding skeletal and facial point subsets via the skeletal prediction subnetwork and facial prediction subnetwork. For quantitative evaluation, the accuracy was calculated with shape errors and landmark errors between the predicted skeleton or face with corresponding ground truths. The shape error was calculated by comparing the predicted point sets with the ground truths, with P2P-ConvGC outperforming existing state-of-the-art algorithms including P2P-Net, P2P-ASNL, and P2P-Conv. The total landmark errors (Euclidean distances of craniomaxillofacial landmarks) of P2P-ConvGC in the upper skull, mandible, and facial soft tissues were 1.964 ± 0.904 mm, 2.398 ± 1.174 mm, and 2.226 ± 0.774 mm, respectively. Furthermore, the clinical feasibility of the bidirectional model was validated using a clinical cohort. The result demonstrated its prediction ability with average surface deviation errors of 0.895 ± 0.175 mm for facial prediction and 0.906 ± 0.082 mm for skeletal prediction. To conclude, our proposed model achieved good performance on the subject-specific prediction of facial and skeletal shapes and showed clinical application potential in postoperative facial prediction and VSP for orthognathic surgery. [ABSTRACT FROM AUTHOR]

In the recent paper "On a formula for sets of constant width in 2D, Comm. Pure Appl. Anal. 18 (2019), 2117–2131", we gave a constructive formula for all 2d sets of constant width. Based on this result we derive here a formula for the parametrization of the boundary of bodies of constant width in 3 dimensions, with the formula depending on one function defined on S 2 . Each such function gives a minimal value r 0 and for all r ≥ r 0 one finds a body of constant width 2r. Moreover, we show that all bodies of constant width in 3d have such a parametrization. The last result needs a tool that we describe as 'shadow domain' and which is explained in an appendix. The construction is explicit and offers a parametrization different from the one given by T. Bayen, T. Lachand-Robert and É. Oudet in "Analytic parametrization of three-dimensional bodies of constant width. Arch. Ration. Mech. Anal., 186 (2007), 225–249". [ABSTRACT FROM AUTHOR]

Background: 3D visualization systems in laparoscopic surgery have been proposed to improve manual task handling compared to 2D, however, few studies have compared the intra‐operative efficacy in laparoscopic cholecystectomy (LC). The aim of this study is to determine if there is a benefit in intra‐operative efficiency when using a 3D visualization system in difficult LC compared to traditional 2D visualization systems. Method s : Retrospective analysis of 'difficult' LCs (Grades 3 or 4) was completed. The assessor was blinded as all cases were recorded and viewed in 2D only. Variables collected included time to complete steps, missed hook diathermy attempts, failed grasp attempts, missed clip attempts and preparation steps for intra‐operative cholangiogram (IOC). Multiple linear regression was undertaken for time variables, Poisson regression or negative binomial regression was completed for continuous variables. Results: Fifty‐two operative videos of 'difficult' LC were reviewed. 3D systems were associated with reduced operative times, although this was not statistically significant (CI: −2.93–14.93, P‐value = 0.183). Dissection of the anterior fold to achieve the critical view of safety was significantly faster by 3.55 min (CI: 1.215–9.206, P‐value = 0.002), and with considerably fewer errors when using 3D systems. Fewer IOC preparation errors were observed with a 3D system compared with a 2D system. Conclusions: 3D systems appear to enhance operator efficiency, allowing faster completion of critical steps with fewer errors. This pilot study underscores the utility of video annotation for intra‐operative assessment and suggests that, in larger multi‐centre studies, 3D systems may demonstrate superior intra‐operative efficiency over 2D systems during a 'difficult' LC. [ABSTRACT FROM AUTHOR]

The University of Johannesburg has integrated serious games into its teaching, exemplified by Codebreakers, a 2D game teaching information theory. While successful, Codebreakers lacked personalisation and used a criticised assessment method based on answer streaks. Knowledge tracing algorithms, known for their effectiveness in intelligent tutoring systems, were considered to address these limitations. This led to the research question: "Can a new serious game be designed, incorporating knowledge tracing algorithms to deliver personalised learning experiences in telecommunications education?" In response, an escape-themed serious game was developed, integrating Bayesian Knowledge Tracing as a statistical student model for personalised learning. This innovative approach combines free-roam gameplay with tailored educational content, significantly advancing serious game design. While primarily aimed at enhancing Codebreakers, this new game contributes substantially to serious game theory by successfully implementing personalised learning within an engaging format. The project showcases the potential of knowledge tracing algorithms in creating adaptive, student-centered learning experiences within the context of educational games. [ABSTRACT FROM AUTHOR]

Background: Unintended secondary changes in the posterior tibial slope (PTS) and tibial torsion angle (TTA) may occur after medial open-wedge high tibial osteotomy (MOWHTO). In surgical procedures using patient-specific instruments (PSIs), it is essential to reproduce the PTS and TTA that were planned in simulations. Purpose: To analyze the factors causing unintended sagittal and axial alignment changes after MOWHTO. Study Design: Case series; Level of evidence, 4. Methods: Overall, 63 patients (70 knees) who underwent MOWHTO using a PSI between June 2020 and June 2023 were retrospectively reviewed. Preoperative and postoperative computed tomography scans were 3-dimensionally reconstructed. Simulated osteotomy was performed so that the weightbearing line could pass through the target point. A PSI gapper was 3-dimensionally printed to fit the posteromedial corner of the osteotomy gap in the simulated HTO model. After MOWHTO using the PSI gapper, the actual postoperative model was compared with the preoperative or simulation model. This assessment included PTS, TTA, hinge axis, and osteotomy-related parameters. Cortical breakage around the lateral hinge was evaluated to assess stability. Results: The mean PTS and TTA did not change in the simulation. However, significant changes were observed in the actual postoperative PTS and TTA (change, –2.4°± 2.2° and −3.9°± 4.7°, respectively). The PTS was reduced, while the TTA decreased with internal rotation of the distal fragment. The difference in the axial hinge axis angle (AHA) between the simulation and actual surgery was the factor most correlated with the difference in the PTS (r = 0.625; P <.001). In regression analysis, the difference in the AHA was the only factor associated with the difference in the PTS (β = 0.558; P =.001), and there were no factors that showed any significant associations with the difference in the TTA. In subgroup analyses for the change in the TTA, the correction angle and anterior osteotomy angle were significantly higher in the more internal rotation group (P =.023 and P =.010, respectively). The TTA change was significantly higher in the unstable group with lateral cortical breakage (P =.018). The unstable group was more likely to show an internal rotation of ≥5° (odds ratio, 5.0; P =.007). Conclusion: The AHA was associated with a difference in the PTS between the simulation and actual surgery. The change in the TTA was caused by a combination of multiple factors, such as a large correction angle and anterior osteotomy angle, but mainly by instability of the lateral cortical hinge. [ABSTRACT FROM AUTHOR]

Background: Assessment of 3-dimensional (3D) femoral head coverage is critical in evaluating, preoperative planning, and treating hip dysplasia. Purpose: To (1) propose a mathematical model to establish 3D femoral head coverage using conventional computed tomography (CT), (2) determine the correlation of 2D parameters with 3D coverage, and (3) characterize the patterns of dysplasia based on 3D morphology. Study Design: Cross-sectional study; Level of evidence, 3. Methods: We identified 30 patients (n = hips) with symptomatic dysplasia and 30 patients (n = hips) without dysplasia. Patients with dysplastic hips were matched with regard to sex, age, and body mass index to those with nondysplastic hips. Preoperative CTs were analyzed using 3D software, and 3D femoral head surface area coverage (FHSAC; in %) was assessed in 4 quadrant zones: anteromedial, anterolateral, posteromedial, and posterolateral. To assess lateral coverage of the femoral head, we introduced the anterolateral femoral head coverage angle (ALFC) and the posterolateral femoral head coverage angle (PLFC). Results: Reduced femoral head coverage was more pronounced in dysplastic versus nondysplastic hips in the anterolateral quadrant (18% vs 40.7%, respectively) and posterolateral quadrant (35.8% vs 56.9%, respectively) (P <.0001 for both). Dysplastic hips had smaller ALFC and PLFC (18.4° vs 38.7°; P <.0001; 47.2° vs 72.3°; P =.0002). Anterolateral and posterolateral FHSAC were strongly correlated with the ALFC (r = 0.88; P <.0001) and the PLFC (r = 0.82; P <.0001) along with the lateral center-edge angle (anterolateral, r = 0.75; P <.0001; posterolateral, r = 0.73; P <.0001). Prediction models established for FHSAC had strong agreement with explanatory CT variables (anterolateral: r = 0.91; P <.0001; posterolateral: r = 0.90; P <.0001). The cutoff values for anterolateral and posterolateral FHSAC were 25% and 41%, respectively. In dysplastic hips, global deficiency was most common (15/30 hips), 9 hips showed an anterolateral deficiency, and 4 hips had a posterolateral deficiency pattern. Conclusion: The ALFC and The PLFC were strongly correlated with 3D lateral FHSAC and were able to predict 3D coverage accurately. [ABSTRACT FROM AUTHOR]

Background: The paranasal depression is a common facial feature of Oriental populations. One of the most wildly used method to improve it was paranasal augmentation using expanded polytetrafluoroethylene (ePTFE). The effectiveness of it should be tested by three-dimensional morphological measurements. Methods: Patients who underwent paranasal augmentation using ePTFE between January 2017 and December 2022 were recruited in the study. The preoperative and postoperative clinical variables and three-dimensional measurement of patients were also collected. The satisfaction outcome were assessed. Results: By establishing a coordinate system based on the Frankfurt plane, 16 landmarks including nasal alar crest, subnasal point, upper lip, pogonion, glabella, sub-cheek, orbitale, tragion in left and right side of faces were marked. Five segments, 4 ratios, and 3 angles were measured based on it. The significant increase of segments, ratios, and angles indicated that paranasal augmentation could increase the protrusion of paranasal area, both in absolute value and relative proportion. The significant decrease of other data indicated that the protrusion difference between paranasal base and upper lip, forehead, and chin, respectively, were shortened after surgery. The average size of implant was 6.54 ± 1.02 mm, and the average increase of paranasal height was 4.38 ± 1.04 mm postoperatively. This indicates that two-thirds of its height will ultimately be reflected effectively in the sagittal elevation of the paranasal base. Conclusions: Paranasal augmentation using ePTFE could effectively increase paranasal height and improve subunits relationships, and the ePTFE prosthesis should be designed and carve considering the 1/3 loss of height after implantation. Level of Evidence III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266. [ABSTRACT FROM AUTHOR]

Stent underexpansion in calcified coronary stenosis is an important predictor of major short- and long-term adverse cardiovascular events. In this case, we describe a novel method for assessing stent expansion using 3-dimensional stent reconstruction with C-arm motion compensated computed tomography.

Abstract Deconstructing surgeries into steps and providing instructions with illustrations has been the staple of surgical textbooks for decades. However, it may be difficult for the novice surgeon to interpret 2‐dimensional (2D) illustrations into 3D surgeries. The objective of this study is to create operable models that demonstrate the progression of surgery in 3D and allow for mastering the final steps of the operation first. Mastoidectomy was performed in a stepwise fashion to different end points on 5 identical 3D‐printed temporal bone models to represent 5 major steps of the operation. The drilled models were computed tomography scanned and the subsequent images were used to create 3D model copies of each step. This is the first study to demonstrate that it is possible to create, scan, and copy stepwise, operable, patient‐specific 3D‐printed models, which the trainee can both reference as a 3D dissection guide and can operate on repeatedly and in any order.

Objectives: The aim of this study was to identify cone-beam computed tomography (CBCT) protocols that offer an optimal balance between effective dose (ED) and 3D model for orthognathic virtual surgery planning, using CT as a reference, and to assess whether such protocols can be defined based on technical image quality metrics., Methods: Eleven CBCT (VISO G7, Planmeca Oy, Helsinki, Finland) scan protocols were selected out of 32 candidate protocols, based on ED and technical image quality measurements. Next, an anthropomorphic RANDO SK150 phantom was scanned using these 11 CBCT protocols and 2 CT scanners for bone quantity assessments. The resulting DICOM (Digital Imaging and Communications in Medicine) files were converted into Standard Tessellation Language (STL) models that were used for bone volume and area measurements in the predefined orbital region to assess the validity of each CBCT protocol for virtual surgical planning., Results: The highest CBCT bone volume and area of the STL models were obtained using normal dose protocol (F2) and ultra-low dose protocol (J13), which resulted in 48% and 96% of the mean STL bone volume and 48% and 95% of the bone area measured on CT scanners, respectively., Conclusions: The normal dose CBCT protocol "F2" offered optimal bone area and volume balance for STL. The optimal CBCT protocol can be defined using contrast-to-noise ratio and modulation transfer function values that were similar to those of the reference CT scanners'. CBCT scanners with selected protocols can offer a viable alternative to CT scanners for acquiring STL models for virtual surgical planning at a lower effective dose., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology and the International Association of Dentomaxillofacial Radiology.)

Background: Although the substrate in persistent atrial fibrillation (PeAF) is not limited to the pulmonary veins (PVs), PV isolation (PVI) remains the cornerstone ablation strategy., Objectives: The aim of this study was to describe the mechanism of outgoing wavefronts (WFs) originating in the PV sleeves during PeAF., Methods: Eleven patients presenting for first-time PeAF ablation were recruited (mean age 63.1 ± 10.9 years, 91% men). A 64-electrode catheter (Constellation; 38 mm) was positioned within the PV under fluoroscopic guidance. An inverse mapping technique was used to reconstruct unipolar atrial electrograms on the PV surface, and the resulting phase maps were used to identify incoming and outgoing WFs at the PV junction and to classify focal and re-entrant activity within the PV sleeves., Results: During PeAF, the PVs gave rise to outgoing WFs with a frequency of 3.7 s -1 (Q1-Q3: 3.4-5.4 s -1 ) compared with 3.6 s -1 (Q1-Q3: 2.8-4.2 s -1 ) for incoming WFs. Circuitous macroscopic re-entry was the dominant mechanism driving outgoing WFs (frequency of re-entry 2.7 s -1 [Q1-Q3: 2.0-3.3 s -1 ] compared with focal activity 1.4 s -1 [Q1-Q3: 1.1-1.5 s -1 ]; P < 0.006). This was initiated by incoming WFs in 80% of cases. Consecutive focal activation from the same location was infrequent (10.0% ± 6.6%, n = 10). Rotors ≥360° were never observed. The median ratio (R) of outgoing to incoming WF frequency was 1.14 (Q1-Q3: 0.84-1.75), with R > 1 in 6 of 11 PVs., Conclusions: Electric activity generated by PV sleeves during PeAF is due mainly to circuitous re-entry initiated by incoming waves, frequently with R > 1. That is, the PVs act less as drivers of atrial fibrillation than as "echo chambers" that sustain and amplify fibrillatory activity., Competing Interests: Funding Support and Author Disclosures Basket catheters were provided by Boston Scientific. Drs Al-Kaisey and Parameswaran are supported by a National Health and Medical Research Council (NHMRC) research scholarship. Prof Kalman is supported by a practitioner fellowship from the NHMRC; and has received research support from Biosense Webster and Medtronic. Drs Meng and Sunderland were supported by Endeavour Fund Grant CONT-50916-ENDSI-UOA from the New Zealand Ministry of Business and Innovation. Assoc Prof Budgett and Prof Smaill have received funding from the New Zealand Ministry of Business and Innovation and from Return on Sciences, New Zealand. Dr Kistler is a recipient of a Clinical Investigator grant from the NHMRC of Australia; has received grants from the Baker Department of Metabolic Health University of Melbourne; has received speaker fees from Abbott Medical; and has served on an advisory board for Biosense Webster. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Side branch (SB) occlusion during bifurcation stenting is a serious complication. This study aimed to predict SB compromise (SBC) using optical coherence tomography (OCT)., Methods and results: Among the 168 patients who enrolled in the 3D-OCT Bifurcation Registry, 111 bifurcation lesions were analyzed to develop an OCT risk score for predicting SBC. SBC was defined as worsening of angiographic SB ostial stenosis (≥90%) immediately after stenting. On the basis of OCT before stenting, geometric parameters (SB diameter [SBd], length from proximal branching point to carina tip [BP-CT length], and distance of the polygon of confluence [dPOC]) and 3-dimensional bifurcation types (parallel or perpendicular) were evaluated. SBC occurred in 36 (32%) lesions. The parallel-type bifurcation was significantly more frequent in lesions with SBC. The receiver operating characteristic curve indicated SBd ≤1.77 mm (area under the curve [AUC]=0.73, sensitivity 64%, specificity 75%), BP-CT length ≤1.8 mm (AUC=0.83, sensitivity 86%, specificity 68%), and dPOC ≤3.96 mm (AUC=0.68, sensitivity 63%, specificity 69%) as the best cut-off values for predicting SBC. To create the OCT risk score, we assigned 1 point to each of these factors. As the score increased, the frequency of SBC increased significantly (Score 0, 0%; Score 1, 8.7%; Score 2, 28%; Score 3, 58%; Score 4, 85%; P<0.0001)., Conclusions: Prediction of SBC using OCT is feasible with high probability.

Tricuspid valve (TV) remodeling occurs in patients with atrial fibrillation (AF); however, the affecting factor related to TV remodeling in AF remains to be elucidated. We sought to explore whether the AF persistence itself affects right heart remodeling. A total of 372 lone AF patients (234 paroxysmal AF [paroxAF] and 138 persistent AF [persAF]) who underwent 3-dimensional transesophageal echocardiography (3D-TEE) was retrospectively reviewed. The duration from first-detected episode of AF to the TEE exam date was defined as AF duration. PersAF patients had a larger TV area index (625.4 vs 719.0 mm2/m2; P < 0.001) and a higher right atrium area-to-right ventricle end-systolic area ratio (RA/RVESA ratio, 1.7 vs 1.9; P = 0.005) than paroxAF patients. The prevalence of AF-tricuspid regurgitation was higher in persAF than in paroxAF patients (1.3% vs 12.3%; P < 0.001). In persAF patients, AF duration was moderately correlated with TV diameter and 3D-TEE-derived TV annular area but not in paroxAF. On multivariable analysis, AF duration was independently associated with TV annular dilatation even after adjustment for RA/RVESA ratio and tricuspid regurgitation severity (β 0.37 [95% CI: 0.77–1.81]; P < 0.001). Additionally, AF duration with cutoff values of 20 months for predicting TV annular dilatation and 37 months for predicting RA/RVESA ratio > 2.1 had both high diagnostic accuracies among persAF patients (both P < 0.01). AF duration itself is independently associated with right heart remodeling in persAF but not in paroxAF, such as TV annular dilatation and predominant RA remodeling which may lead to subsequent TR progression and adverse outcomes. • Previous studies have suggested that increasing tricuspid regurgitation (TR) severity is associated with worse survival and atrial fibrillation (AF) persisting itself is associated with adverse cardiovascular outcomes; hence it is important to prevent tricuspid valve (TV) remodeling and progression of atrial functional TR (AF-TR) to improve prognosis. • In this study, AF duration itself is one of independent determinants of TV annular dilatation only in patients with persistent AF, not in paroxysmal AF. • Significant TV annular dilatation (TV annular area index ≥840 mm2/m2) and predominant right atrial remodeling (right atrium area-to-right ventricle end-systolic area ratio > 2.1) has already initiated at AF duration of 20 months and 37 months, respectively. • Based on the relationship between AF duration and right heart remodeling to progress along the time sequence in this study, early rhythm control may be important in the management of AF patients to prevent right heart structure remodeling leading to the incidence of AF-TR. [ABSTRACT FROM AUTHOR]

Through the integration of SEM-BSE and TEM, we gained a comprehensive 3-dimensional understanding of different distribution patterns of inner hydration products of slag. For fully hydrated small slag grains, two distinct sub-zones were formed in the rims. Lath-like, well-crystalline hydrotalcite-like crystals were found to precipitate, grow, and accumulate near the boundary, forming a layer with a thickness slightly exceeding 0.5 μm. In the center, entrapped calcium and silicon played roles in the formation of a homogeneous and fibrous C−(A)–S–H gel phase. The concentration equilibrium between cement matrix and grain core led to the establishment of a similar grey pixel value and Ca/Si atomic ratio of gel phase at ~1.10. As the size of slag grains increased, three sub-zones became visible. Hydrotalcite-like phase was enriched near the boundary, followed by a sandwiched area abundant in C–(A)–S–H gel phase. Due to the low mobility and increased migration distance, newly released magnesium from reaction front accumulated locally to form a new Mg-rich region. [ABSTRACT FROM AUTHOR]

Deconstructing surgeries into steps and providing instructions with illustrations has been the staple of surgical textbooks for decades. However, it may be difficult for the novice surgeon to interpret 2-dimensional (2D) illustrations into 3D surgeries. The objective of this study is to create operable models that demonstrate the progression of surgery in 3D and allow for mastering the final steps of the operation first. Mastoidectomy was performed in a stepwise fashion to different end points on 5 identical 3D-printed temporal bone models to represent 5 major steps of the operation. The drilled models were computed tomography scanned and the subsequent images were used to create 3D model copies of each step. This is the first study to demonstrate that it is possible to create, scan, and copy stepwise, operable, patient-specific 3D-printed models, which the trainee can both reference as a 3D dissection guide and can operate on repeatedly and in any order., Competing Interests: None., (© 2024 The Authors. OTO Open published by Wiley Periodicals LLC on behalf of American Academy of Otolaryngology–Head and Neck Surgery Foundation.)

Transformed lung organoids have extensive applications in lung cancer modeling and drug screening. Traditional two-dimensional (2D) cultures fail to propagate a large subpopulation of murine primary tumors in vitro. However, three-dimensional (3D) air-liquid interface (ALI) cultures, which are employed to grow normal lung organoids, can be used to efficiently culture cancerous lung tumor cells. Here, we detail a procedure for cultivating genetically modified lung organoids in 3D-ALI cultures. This protocol contains two parts. The first part describes how to transduce lung epithelial cells, which are either freshly sorted from lungs or from actively growing murine organoids, with virus in order to modify gene expression. The target lung cells are incubated with virus for 1-2 h for transduction. Then, the transduced cells are thoroughly washed and mixed with stromal support cells and Matrigel and are loaded into transwell inserts for culture and validated for genetic modifications through downstream assays. The second part describes how to isolate tumor cells growing orthotopically in genetically engineered mouse models to produce organoid cell lines that can be used for ex vivo drug discovery assays. For this protocol, tumors are isolated from lungs of mice, finely chopped and washed. Then, tumor chunks are mixed with Matrigel for 3D-ALI culture. Finally, organoids budding from tumor chunks are trypsinized and passaged to establish an organoid line. Together these two protocols provide a promising platform to study the genesis, progression, and treatment of lung cancer., (© 2024. The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)