3D Alignment Research Articles

High variability exists in 3D leg alignment analysis, but underlying principles that might lead to agreement on a universal framework could be identified: A systematic review.

To (1) investigate the hypothesis that there is high variability in the reported methods to derive axes and joint orientations from three-dimensional (3D) bone models to (a) perform 3D knee-related leg alignment analysis and (b) define coordinate systems for the femur, tibia and leg and (2) identify underlying principles that might lead to agreement on a universal 3D leg alignment analysis framework. A systematic review of the literature between January 2006 and June 2024 was performed. Articles explicitly reporting methods to derive axes and joint orientations from CT-based 3D bone models for alignment parameters and/or coordinate systems of the femur, tibia and leg were included. Study characteristics and reported methods were extracted and presented as a qualitative synthesis. A total of 93 studies were included. There was high variability in the reported methods to derive axes and joint orientations from 3D bone models. Nevertheless, the reported methods could be categorized into four groups, and several underlying principles of the four groups could be identified. Furthermore, the definitions of femoral and tibial coordinate systems were most frequently based on the mechanical axis (femoral, 13/19 [68%]; tibial, 13/26 [50%]) and a central medial-lateral axis (femoral, 16/19 [84%]; tibial, 12/26 [46%]); no leg coordinate system was reported. Interestingly, of the included studies that reported on leg alignment parameters (76/93, 82%), only a minority reported expressing these in a complete coordinate system (25/76, 33%). There is high variability in 3D knee-related leg alignment analysis. Therefore, universal 3D reference values for alignment parameters cannot yet be defined, and comparison of alignment parameter values between different studies is impossible. However, several underlying principles to the reported methods were identified, which could serve to reach more agreement on a future universal 3D framework for leg alignment analysis. Level I (1).

3D alignment of distant patterns with deep-subwavelength precision using metasurfaces

Measurement of the relative positions of two objects in three dimensions with sub-nanometer precision is essential to fundamental physics experiments and applications such as aligning multi-layer patterns of semiconductor chips. Existing methods, which rely on microscopic imaging and registration of distant patterns, lack the required accuracy and precision for the next generation of three-dimensional (3D) chips. Here we show that 3D misalignment between two distant objects can be measured using metasurface alignment marks, a laser, and a camera with sub-nanometer precision. Through simulations, we demonstrate that the shot noise-limited precisions of the lateral and axial misalignments between the marks are λ0/50, 000 and λ0/6, 300 (λ0: laser’s wavelength), respectively. With its high precision and simplicity, the technique enables the next generation of 3D-integrated optical and electronic chips and paves the way for developing cost-effective and compact sensors relying on sub-nanometer displacement measurements.

Variability of three-dimensional knee morphology cannot be effectively assessed using a coronal plane knee alignment classification in total knee arthroplasty patients.

Optimal reproduction of the native three-dimensional (3D) alignment in total knee arthroplasty (TKA) influences outcomes; however, much of the modern TKA alignment research, such as the coronal plane alignment of the knee (CPAK), focuses only on coronal alignment. Tibial, femoral and tibiofemoral measurements on the axial and sagittal planes were evaluated for their relationship to the arithmetic hip-knee-ankle angle (aHKA) and joint-line obliquity (JLO). These 3D anatomical measurements are also evaluated across CPAK groups. A retrospective analysis of the 360 Med Care computed tomography (CT) database was performed. Patient CT scans were segmented and landmarked. Linear regression analysis compared 12 axial and sagittal plane measurements (representing tibial, femoral and tibiofemoral rotation, tibial slope and femoral flexion) with both aHKA and JLO. Nonparametric tests assessed these anatomical measurements across the different CPAK groups, while Cohen's delta (d) determined the effect size. With a sample size of 7450 osteoarthritic knees, significant but weak relationships (r < 0.30) were observed between all 12 anatomical measurements and both aHKA and JLO. Tibiofemoral rotations between Insall's axis and both the posterior condylar and the surgical transepicondylar axes demonstrated large effect sizes (d > 0.80). However, trivial to small effect sizes (d < 0.50) were broadly observed across the 12 axial and sagittal measurements, underscoring their limited clinical significance. While useful for describing coronal knee anatomy, CPAK phenotypes fail to differentiate tibial, femoral and tibiofemoral rotation, tibial slope or femoral flexion-crucial aspects of 3D surgical planning. Therefore, more comprehensive knee phenotyping solutions are required to guide individualised TKA alignment strategies. Level II.

Four Different Build Angles in 3D-Printed Complete Denture Bases: A Comparative In Vitro Study

In this study, we aimed to investigate the differences in tissue surface adaptation and the variations in distances between reference points on the polished surfaces of 3D-printed denture bases produced at different build angles. The build angles were 0°, 30°, 60°, and 90°, with 15 denture bases printed for each angle. Using the Geomagic Control® software, a 3D best-fit alignment was conducted between the denture base tissue surface and the reference shape of the edentulous maxilla model to calculate the root mean square error. The distances between reference points on the polished surface were measured using digital calipers. A one-way analysis of variance was conducted for statistical analysis. The adaptation, as measured by the root mean square error, varied significantly among denture bases with different build angles. The distances between the anterior and posterior reference points of the polished surface were also significantly different. However, within the limitations of this study, the variations in adaptations and dimensional accuracy across different build angles were within clinically acceptable ranges. In clinical practice, the print angle can be adjusted based on factors such as printing time, resin consumption, and the number of denture bases being printed simultaneously.

Individualized C1-2 intra-articular three-dimensional printed porous titanium alloy cage for craniovertebral deformity

BackgroundCongenital craniovertebral deformity, including basilar invagination (BI) and atlantoaxial instability (AAI), are often associated with three-dimensional (3D) deformity, such as C1-2 rotational deformity, craniocervical kyphosis, C1 lateral inclination, among other abnormalities. Effective management of these conditions requires the restoration of the 3D alignment to achieve optimal reduction. Recently, 3D printing technology has emerged as a valuable tool in spine surgery, offering the significant advantage of allowing surgeons to customize the prosthesis design. This innovation provides an ideal solution for precise 3D reduction in the treatment of craniovertebral deformities.ObjectiveThis study aims to describe our approach to individualized computer-simulated reduction and the design of C1-2 intra-articular 3D printed porous titanium alloy cages for the quantitative correction of craniovertebral junction deformities.MethodsA retrospective analysis was conducted on patients with craniovertebral deformities treated at our institution using individualized 3D-printed porous titanium alloy cages. Preoperative CT data were used to construct models for 3D realignment simulations. Cage designs were tailored to the simulated joint morphology following computer-assisted realignment. Preoperative and postoperative parameters were statistically analyzed.ResultsFourteen patients were included in the study, with a total of 28 3D-printed porous titanium alloy cages implanted. There were no cases of C2 nerve root resection or vertebral artery injury. All patients experienced symptom relief and stable implant fixation achieved in all cases. No implant-related complications were reported.ConclusionThe use of individualized computer-simulated reduction and the design of C1-2 intra-articular 3D printed porous titanium alloy cage facilitates precise 3D realignment in patients with craniovertebral deformities, demonstrating effectiveness in symptom relief and stability.

Talar and Calcaneal Coordinate Axes Definitions across Foot Pathologies

The understanding of foot and ankle biomechanics is improving as new technology provides more detailed information about the motion of foot and ankle bones with biplane fluoroscopy, as well as the ability to analyze the hindfoot under weightbearing conditions with weightbearing computed tomography. Three-dimensional anatomical coordinate systems are necessary to describe the 3D alignment and kinematics of the foot and ankle. The lack of standard coordinate systems across research study sites can significantly alter experimental data analyses used for pre-surgical evaluation and post-operative outcome assessments. Clinical treatment paradigms are changing based on the expanding knowledge of complex pes planovalgus morphologies or progressive collapsing foot deformity, which is present in both neurologic and non-neurologic populations. Four patient cohorts were created from 10 flexible PCFD, 10 rigid PCFD, 10 adult cerebral palsy, and 10 asymptomatic control patients. Six coordinate systems were tested on both the talus and calcaneus for all groups. The aim of this study was to evaluate axes definitions for the subtalar joint across four different patient populations to determine the influence of morphology on the implementation of previously defined coordinate systems. Different morphologic presentations from various pathologies have a substantial impact on coordinate system definitions, given that numerous axes definitions are defined through geometric fits or manual landmark selection. Automated coordinate systems that align with clinically relevant anatomic planes are preferred. Principal component axes are automatic, but do not align with clinically relevant planes and should not be used for such analysis where anatomic planes are critical.

Complete 3D Relationships Extraction Modality Alignment Network for 3D Dense Captioning.

3D dense captioning aims to semantically describe each object detected in a 3D scene, which plays a significant role in 3D scene understanding. Previous works lack a complete definition of 3D spatial relationships and the directly integrate visual and language modalities, thus ignoring the discrepancies between the two modalities. To address these issues, we propose a novel complete 3D relationship extraction modality alignment network, which consists of three steps: 3D object detection, complete 3D relationships extraction, and modality alignment caption. To comprehensively capture the 3D spatial relationship features, we define a complete set of 3D spatial relationships, including the local spatial relationship between objects and the global spatial relationship between each object and the entire scene. To this end, we propose a complete 3D relationships extraction module based on message passing and self-attention to mine multi-scale spatial relationship features and inspect the transformation to obtain features in different views. In addition, we propose the modality alignment caption module to fuse multi-scale relationship features and generate descriptions to bridge the semantic gap from the visual space to the language space with the prior information in the word embedding, and help generate improved descriptions for the 3D scene. Extensive experiments demonstrate that the proposed model outperforms the state-of-the-art methods on the ScanRefer and Nr3D datasets.

Effects of three-dimensional femur and tibia postures on the parameters of standing long-leg radiographs for osteoarthritic knees in elderly female subjects

BackgroundLong-leg frontal radiographs of the lower extremities are used to assess knee osteoarthritis. Given the three-dimensional (3D) nature of alignment changes in osteoarthritis, postural alterations in the femur and tibia extend beyond the coronal plane (in-plane) to include the transverse and sagittal planes (out-of-plane). This study investigates the impact of these out-of-plane factors on in-plane knee alignment parameters observed in frontal radiographs. MethodsA total of 97 osteoarthritic knees in women were examined. Using a 3D-to-two-dimensional (2D) image matching technique, we evaluated the 3D postures of the femur and tibia in the standing position as viewed from frontal radiographs in the world coordinate system. Statistical analyses were conducted to explore associations between these 3D postures and 2D alignment parameters obtained from frontal radiographs under identical conditions. FindingsThe femur exhibited a medial inclination of 2.7°, a posterior inclination of 3.9°, and an internal rotation of 4.2°, whereas the tibia showed a lateral inclination of 6.4°, an anterior inclination of 6.7°, and an internal rotation of 6.7°. Both coronal and rotational postures of femur and tibia influenced the hip-knee-ankle angle, mechanical axis percentage, and medial proximal tibial angle. However, only coronal factors of tibia impacted tibial joint line obliquity relative to the floor. InterpretationAttention should be paid to the potential impact of the out-of-plane postures of the femur and tibia on parameters assessed in plain frontal radiographs of the lower extremities.

3D Directional Assembly of Liquid Crystal Molecules.

The precise construction of hierarchically long-range ordered structures using molecules as fundamental building blocks can fully harness their anisotropy and potential. However, the 3D, high-precision, and single-step directional assembly of molecules is a long-pending challenge. Here, a 3D directional molecular assembly strategy via femtosecond laser direct writing (FsLDW) is proposed and the feasibility of this approach using liquid crystal (LC) molecules as an illustrative example is demonstrated. The physical mechanism for femtosecond (fs) laser-induced assembly of LC molecules is investigated, and precise 3D arbitrary assembly of LC molecules is achieved by defining the discretized laser scanning pathway. Additionally, an LC-based Fresnel zone plate array with polarization selection and colorization imaging functions is fabricated to further illustrate the potential of this method. This study not only introduces a 3D high-resolution alignment method for LC-based functional devices but also establishes a universal protocol for the precise 3D directional assembly of anisotropic molecules.

Development and validation of a fully automated tool to quantify 3D foot and ankle alignment using weight-bearing CT

IntroductionFoot and ankle alignment plays a pivotal role in human gait and posture. Traditional assessment methods, relying on 2D standing radiographs, present limitations in capturing the dynamic 3D nature of foot alignment during weight-bearing and are prone to observer error. This study aims to integrate weight-bearing CT (WBCT) imaging and advanced deep learning (DL) techniques to automate and enhance quantification of the 3D foot and ankle alignment. MethodsThirty-two patients who underwent a WBCT of the foot and ankle were retrospectively included. After training and validation of a 3D nnU-Net model on 45 cases to automate the segmentation into bony models, 35 clinically relevant 3D measurements were automatically computed using a custom-made tool. Automated measurements were assessed for accuracy against manual measurements, while the latter were analyzed for inter-observer reliability. ResultsDL-segmentation results showed a mean dice coefficient of 0.95 and mean Hausdorff distance of 1.41 mm. A good to excellent reliability and mean prediction error of under 2 degrees was found for all angles except the talonavicular coverage angle and distal metatarsal articular angle. ConclusionIn summary, this study introduces a fully automated framework for quantifying foot and ankle alignment, showcasing reliability comparable to current clinical practice measurements. This operator-friendly and time-efficient tool holds promise for implementation in clinical settings, benefiting both radiologists and surgeons. Future studies are encouraged to assess the tool's impact on streamlining image assessment workflows in a clinical environment.

An optimized multisource acquisition and registration workflow for imaging guided ventricular tachycardia ablation

Abstract Background Catheter ablation is a cornerstone treatment for scar-related ventricular arrhythmias arising in patients affected by structural heart disease. Imaging integration with electroanatomical mapping (EAM) suites for ventricular tachycardia (VT) ablation procedural guidance is an established step for advanced substrate characterization and treatment. Purpose To compare and validate different approaches for intraprocedural multisource imaging registration and integration with EAM suites for VT ablation guidance. Methods Thirty consecutive patients prospectively enrolled in the ongoing VOYAGE clinical trial for imaging guided/aided VT ablation at our center were retrospectively analyzed. Multidetector computed tomography (MDCT) and late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) imaging was performed before procedure. MDCT and LGE-CMR images were both acquired during end-expiratory breath hold. Same cardiac cycle phase images were used. Wide band LGE-CMR was acquired in case of a cardiac implantable electronic device was present to reduce artifacts. Images were imported in ADAS3D software. MDCT and CMR images were manually registered using established anatomical landmarks (left ventricle outflow tract, left ventricle apex, papillary muscles, left and right ventricle junction), were then respectively processed for aortic/ventricular anatomical reconstruction and myocardial characterization and then imported in CARTO3 electroanatomical mapping suite for procedural guidance. Registration between EAM and imaging was either performed with ascending aorta fast anatomical mapping (FAM) and 3D landmark alignment with aortic MDCT or via intracardiac echocardiography (ICE) left ventricle (LV) chamber segmentation and 3D landmark alignment with ventricular MDCT. ICE segmentation was also obtained for every case regardless of aortic FAM. Surface match between ICE and MDCT LV chamber reconstructions was calculated for method comparison. Results All 30 patients had an ICE segmentation of the LV, with a mean of 15,66±4,89 contours. Aortic FAM was obtained and used for aortic MDCT registration in 10 subjects. LV ICE was instead used for imaging alignment in 20 subjects. When compared to aortic FAM, LV ICE to LV MDCT alignment achieved lower average surface distance (3,86±1,41 mm vs 8,884±6,77 mm; p&amp;lt;0,001), lower minimum surface distance (0,002±0,03 vs 0,07±0,06; p= 0,001) and lower maximum surface distance (14,16±4,37 vs 22,93±11,10; p&amp;lt;0,001). Conclusion An optimized workflow consisting of ICE LV chamber segmentation was superior in terms of 3D surface distance to aortic FAM reconstruction to obtain reliable multisource imaging registration for MDCT/CMR guided/aided VT ablation.

Subtraction of liposome signals in cryo-EM structural determination of protein–liposome complexes

Abstract Reconstituting membrane proteins in liposomes and determining their structure is a common method for determining membrane protein structures using single-particle cryo-electron microscopy (cryo-EM). However, the strong signal of liposomes under cryo-EM imaging conditions often interferes with the structural determination of the embedded membrane proteins. Here, we propose a liposome signal subtraction method based on single-particle two-dimensional (2D) classification average images, aimed at enhancing the reconstruction resolution of membrane proteins. We analyzed the signal distribution characteristics of liposomes and proteins within the 2D classification average images of protein–liposome complexes in the frequency domain. Based on this analysis, we designed a method to subtract the liposome signals from the original particle images. After the subtraction, the accuracy of single-particle three-dimensional (3D) alignment was improved, enhancing the resolution of the final 3D reconstruction. We demonstrated this method using a PIEZO1-proteoliposome dataset by improving the resolution of the PIEZO1 protein.

Polarization Holes as an Indicator of Magnetic Field−Angular Momentum Alignment. I. Initial Tests

The formation of protostellar disks is still a mystery, largely due to the difficulties in observations that can constrain theories. For example, the 3D alignment between the rotation of the disk and the magnetic fields (B-fields) in the formation environment is critical in some models, but so far it is impossible to observe. Here we study the possibility of probing the alignment between B-field and disk rotation using “polarization holes” (PHs). PHs are widely observed and are caused by unresolved B-field structures. With ideal magnetohydrodynamic simulations, we demonstrate that different initial alignments between B-field and angular momentum (AM) can result in B-field structures that are distinct enough to produce distinguishable PHs. Thus, PHs can potentially serve as probes for alignments between B-field and AM in disk formation.

Electrospun Aligned Nanofiber Yarns Constructed Biomimetic M-Type Interface Integrated into Precise Co-Culture System as Muscle-Tendon Junction-on-a-Chip for Drug Development.

The incorporation of engineered muscle-tendon junction (MTJ) with organ-on-a-chip technology provides promising in vitro models for the understanding of cell-cell interaction at the interface between muscle and tendon tissues. However, developing engineered MTJ tissue with biomimetic anatomical interface structure remains challenging, and the precise co-culture of engineered interface tissue is further regarded as a remarkable obstacle. Herein, an interwoven waving approach is presented to develop engineered MTJ tissue with a biomimetic "M-type" interface structure, and further integrated into a precise co-culture microfluidic device for functional MTJ-on-a-chip fabrication. These multiscale MTJ scaffolds based on electrospun nanofiber yarns enabled 3D cellular alignment and differentiation, and the "M-type" structure led to cellular organization and interaction at the interface zone. Crucially, a compartmentalized co-culture system is integrated into an MTJ-on-a-chip device for the precise co-culture of muscle and tendon zones using their medium at the same time. Such an MTJ-on-a-chip device is further served for drug-associated MTJ toxic or protective efficacy investigations. These results highlight that these interwoven nanofibrous scaffolds with biomimetic "M-type" interface are beneficial for engineered MTJ tissue development, and MTJ-on-a-chip with precise co-culture system indicated their promising potential as in vitro musculoskeletal models for drug development and biological mechanism studies.

A robust transformer-based pipeline of 3D cell alignment, denoise and instance segmentation on electron microscopy sequence images

Germline cells are critical for transmitting genetic information to subsequent generations in biological organisms. While their differentiation from somatic cells during embryonic development is well-documented in most animals, the regulatory mechanisms initiating plant germline cells are not well understood. To thoroughly investigate the complex morphological transformations of their ultrastructure over developmental time, nanoscale 3D reconstruction of entire plant tissues is necessary, achievable exclusively through electron microscopy imaging. This paper presents a full-process framework designed for reconstructing large-volume plant tissue from serial electron microscopy images. The framework ensures end-to-end direct output of reconstruction results, including topological networks and morphological analysis. The proposed 3D cell alignment, denoise, and instance segmentation pipeline (3DCADS) leverages deep learning to provide a cell instance segmentation workflow for electron microscopy image series, ensuring accurate and robust 3D cell reconstructions with high computational efficiency. The pipeline involves five stages: the registration of electron microscopy serial images; image enhancement and denoising; semantic segmentation using a Transformer-based neural network; instance segmentation through a supervoxel-based clustering algorithm; and an automated analysis and statistical assessment of the reconstruction results, with the mapping of topological connections. The 3DCADS model's precision was validated on a plant tissue ground-truth dataset, outperforming traditional baseline models and deep learning baselines in overall accuracy. The framework was applied to the reconstruction of early meiosis stages in the anthers of Arabidopsis thaliana, resulting in a topological connectivity network and analysis of morphological parameters and characteristics of cell distribution. The experiment underscores the 3DCADS model's potential for biological tissue identification and its significance in quantitative analysis of plant cell development, crucial for examining samples across different genetic phenotypes and mutations in plant development. Additionally, the paper discusses the regulatory mechanisms of Arabidopsis thaliana's germline cells and the development of stamen cells before meiosis, offering new insights into the transition from somatic to germline cell fate in plants.

Clubfoot Correction with Ponseti Technique: Three-Dimensional Alignment Analysis and Residual Adult Deformity Effects on Patient-Reported Outcomes

Introduction/Purpose: Few studies have assessed the long-term outcomes of the Ponseti technique and none have utilized 3- dimensional weightbearing analysis. The goal of this study was to understand how potential residual 3D deformities and abnormalities influence patient reported outcomes (PROs). This was accomplished by assessing anatomical foot and ankle alignment in adult clubfoot patients treated with the Ponseti method using 3D weightbearing CT (WBCT) imaging and then correlating residual foot and ankle malalignment with PROs. Methods: There were 37 consecutive patients (57 feet) included and 14 volunteers healthy controls (28 feet) included in this study. Every participant was evaluated using a WBCT (HiRise©) in a bipedal standing position. From these scans Cavus, Adductus, and Varus components were evaluated using multiple 3D measurements calculated using the semi-automatic segmentation software Bonelogic®. Specific Cavus related measurements included sagittal talus-first metatarsal angle and the calcaneal inclination angle. Varus related measurements included talocalcaneal angle in both the sagittal and axial planes as well as the hindfoot moment arm and the hindfoot alignment angle. Adductus deformity was evaluated using talonavicular coverage angle. These measurements were then correlated with patient reported outcome surveys, which included Visual Acuity Scale for pain, PROMIS general health, PROMIS physical function, PROMIS pain interference, pain catastrophic scale, and European foot and ankle society score. Results: There was no significant overall residual 3D-deformity observed in clubfoot patients when compared to controls, with similar FAO measurements observed between the groups, clubfoot=2.63% (95%CI=1.41%-3.85%) and control=3.2% (CI=1.6%- 4.8%,P=0.58). The sagittal talus-first-metatarsal in the clubfoot-patients had a mean-value of -0.12° compared to the controls, −5.2°. Clubfoot patients also had a decreased calcaneal-inclination-angle relative to the controls, 13.01° and 21.5° respectively. Talocalcaneal-angle for clubfoot patients in both the sagittal-plane,44.28°, and axial-plane, 17.74°, were reduced compared to the controls, 57.51° and 25.78°. Talonavicular-coverage-angle in the clubfoot-group (18.63°) was less than the controls (29.19°). Talus- first-metatarsal-angle in the sagittal-plane was significantly correlated with VAS-scores (RSquare=0.19,P=0.0118) and the EFAS- Score (RSquare=0.27,P=0.0025). Talocalcaneal-angle in the sagittal plane was also significantly correlated with the PROMIS-Pain- Interference-score (P=0.038) and PROMIS-Physical-Function-score (RSquare=0.32,P=0.0007). Conclusion: The Ponseti technique is an effective nonsurgical treatment for the overall three-dimensional foot and ankle alignment of Clubfoot. While mild, but statistically significant residual Varus and Adductus deformities were observed in adult clubfoot patients, the overall 3D alignment (FAO) was found to be similar between clubfoot patients and controls. These findings highlight the efficacy of the Ponseti technique and potentially explain the overall good PROs. The results of this study could potentially provide insight into treatment targets that may be applied to help optimize patient outcomes when treating children with Clubfoot in the future. The Ponseti technique is an effective nonsurgical treatment for Clubfoot's overall three-dimensional foot and ankle alignment. While mild, but statistically significant residual Varus and Adductus deformities were observed in adult clubfoot patients, the overall 3D alignment (FAO) was found to be similar between clubfoot patients and controls. These findings highlight the efficacy of the Ponseti technique and potentially explain the overall good PROs. The results of this study could potentially provide insight into treatment targets that may be applied to help optimize patient outcomes when treating children with Clubfoot in the future.

Are 3D Face Shapes Expressive Enough for Recognising Continuous Emotions and Action Unit Intensities?

Recognising continuous emotions and action unit (AU) intensities from face videos, requires a spatial and temporal understanding of expression dynamics. Existing works primarily rely on 2D face appearance features to extract such dynamics. This work focuses on a promising alternative based on parametric 3D face alignment models, which disentangle different factors of variation, including expression-induced shape variations. We aim to understand how expressive 3D face shapes are in estimating valence-arousal and AU intensities compared to the state-of-the-art 2D appearance-based models. We benchmark five recent 3D face models: ExpNet, 3DDFA-V2, RingNet, DECA, and EMOCA. In valence-arousal estimation, expression features of 3D face models consistently surpassed previous works and yielded an average concordance correlation of. 745 and. 574 on SEWA and AVEC 2019 CES corpora, respectively. We also study how 3D face shapes performed on AU intensity estimation on BP4D and DISFA datasets, and report that 3D face features were on par with 2D appearance features in recognising AUs 4, 6, 10, 12, and 25, but not the entire set of AUs. To understand this discrepancy, we conduct a correspondence analysis between valence-arousal and AUs, which points out that accurate prediction of valence-arousal may require the knowledge of only a few AUs.

Research on 3D point cloud alignment algorithm based on SHOT features.

To overcome the problem of the high initial position of the point cloud required by the traditional Iterative Closest Point (ICP) algorithm, in this paper, we propose a point cloud registration method based on normal vector and directional histogram features (SHOT). Firstly, a hybrid filtering method based on the voxel idea is proposed and verified using the measured point cloud data, and the noise removal rates of 97.5%, 97.8%, and 93.8% are obtained. Secondly, in terms of feature point extraction, the original algorithm is optimized, and the optimized algorithm can better extract the missing part of the point cloud. Finally, a fine alignment method based on normal vector and directional histogram features (SHOT) is proposed, and the improved algorithm is compared with the existing algorithm. Taking the Stanford University point cloud data and the self-measured point cloud data as examples, the plotted iteration-error plots can be concluded that the improved method can reduce the number of iterations by 40.23% and 37.62%, respectively.

In Silico Prediction and Molecular Simulation of Antimicrobial Peptide Variants From Lactobacillus sp. Against Porphyromonas gingivalis and Fusobacterium nucleatum in Oral Squamous Cell Carcinoma

ABSTRACT Porphyromonas gingivalis and Fusobacterium nucleatum are known to contribute to a variety of tumorigenic pathways linked to the progression of oral squamous cell carcinoma (OSCC). The growing global incidence of antibiotic resistance highlights the critical need to consider the use of antimicrobial peptides (AMPs) as a viable alternative to conventional antibiotics. The current study comprehensively tested Lactobacillus sp.−derived AMPs against bacterially exacerbated OSCC. A total of 52 AMPs were obtained from various databases, and an in silico analysis determined their potent antibacterial and anticancer characteristics after a rigorous screening and pruning approach. Twelve AMPs were tested for 3D structural alignment prediction and validation, with the GH12 synthetic AMP serving as a control. These candidate peptides were thoroughly screened against six important virulence proteins of P. gingivalis and four of F. nucleatum, with the lowest energy score of the docked complexes measuring binding affinity and interactions with active residues being chosen. plpl_18 was determined as the most efficient new AMP that interacted with the virulence protein RagB of P. gingivalis and Fap2 of F. nucleatum with docking scores of −238.24 and −254.27 kcal/mol, respectively. This AMP plpl_18 was docked against selective target OSCC regulatory proteins such as cytokines, metallomatrix proteinase, MAPK, E‐cadherin, and JAK‐1 proteins. Among these proteins, it docked against matrix metalloproteinase‐9 with the highest negative docking scores of −7.5, −260.956, and −1361.9 kcal/mol using AutoDock Vina, HPEPDOCK, and ClusPro 2.0, respectively. Molecular dynamic simulation was used to perform extrapolated validation. These computational studies provide an essential foundation for anticipated laboratory and clinical investigations concerning the possibility of adapting therapeutic peptides based on probiotics to combat the proliferation of OSCC, which is accelerated by F. nucleatum and P. gingivalis.

Accurate global and local 3D alignment of cryo-EM density maps using local spatial structural features.

Advances in cryo-electron microscopy (cryo-EM) imaging technologies have led to a rapidly increasing number of cryo-EM density maps. Alignment and comparison of density maps play a crucial role in interpreting structural information, such as conformational heterogeneity analysis using global alignment and atomic model assembly through local alignment. Here, we present a fast and accurate global and local cryo-EM density map alignment method called CryoAlign, that leverages local density feature descriptors to capture spatial structure similarities. CryoAlign is a feature-based cryo-EM map alignment tool, in which the employment of feature-based architecture enables the rapid establishment of point pair correspondences and robust estimation of alignment parameters. Extensive experimental evaluations demonstrate the superiority of CryoAlign over the existing methods in terms of both alignment accuracy and speed.