Anchor Positions Research Articles

Analysis of air‐inflated rubber dam for flood‐fighting at the subway entrance

AbstractThe air‐inflated rubber dam is innovatively adopted in this paper for temporary flood‐fighting at the subway entrance. Numerical studies using the FLAC2D software are carried out to investigate the behavior of the proposed structure. Laboratory model tests are also conducted to verify the accuracy of the numerical model. The results from the model tests agree well with those from the numerical analysis. Parametric studies are carried out to investigate the influences of the external floodwater head, inflated air pressure, and anchor position on the performance of the proposed air‐inflated rubber dam. It is found that the external floodwater head reduces the tensile force but nonlinearly increases the height of the rubber dam. The inflated air pressure has no obvious effect on the cross‐section of the rubber dam but heavily influences the ultimate flood‐fighting height and tensile force. An optimum design line for the inflated air pressure of the rubber dam is provided. A deeper anchor position results in a smaller ultimate flood‐fighting height. A rubber dam design with a lower anchor depth that has to satisfy the requirements of the anchor bolt is therefore concluded.

Change in humeral anchor position significantly affects isometry in ulnar collateral ligament repair: a 3-dimensional computer modeling study.

Medial ulnar collateral ligament (UCL) repair utilization is increasing in recent years, bolstered by shorter rehabilitation and satisfactory clinical outcomes. Although previous literature has illustrated the importance of tunnel position on restoring graft isometry in reconstruction, there remains a paucity of literature guiding anchor placement in UCL repair. The purpose of this study is to design a 3-dimensional (3D) elbow model to understand the effect of anchor location on UCL repair isometry. A 3D computer model of an elbow joint was created using computed tomographic and magnetic resonance imaging MRI scans from a single patient. The humeral and ulnar attachments of the UCL were plotted using 3 methodologies: (1) geometric cloud mapping and (2) quantitative measurements from the anatomic studies by Camp etal and (3) Frangiamore etal. A 3.5-mm-diameter clockface was placed on each attachment site, which allowed for simulation of 12 distinct 1.75-mm deviations in anchor position. The 3 models were ranged through 0°-120° at 10° increments, and the 3D distances were measured between the ligament centroids. The humeral and ulnar anchors were sequentially repositioned around the clockfaces, and construct lengths were again measured to evaluate changes in isometry. A paired Student t test was performed to determine if there was a significant difference in isometry between the humeral and ulnar anchor deviations. Using method 1, the UCL repair length at 90° of elbow flexion was 26.8 mm. This construct underwent 13.6 mm of total excursion for a 46.4% change in length throughout its arc of motion. Method 2 produced a 19.3-mm construct that underwent 0.8 mm of excursion for a 3.9% length change throughout the arc. Method 3 produced a 24.5-mm construct that underwent 2.3 mm of excursion for a 9.4% length change. Identifying ligament footprints using the quantitative anatomic measurements from Camp etal and Frangiamore etal improved construct isometry through 120° of flexion (length changes of 3.9% and 9.4%, respectively) when compared to using the geometric cloud technique alone (46.4% length change). Humeral anchor deviations produced a significant increase in repair construct excursion compared with ulnar anchor deviations (P<.001). When performing UCL repair, small deviations in humeral anchor position may significantly influence ligament repair isometry. Using quantitative anatomic data may help identify anchor positions with improved repair isometry. Particularly when addressing detachments of the humeral footprint, surgeons should be critical of the humeral anchor position in order to restore native anatomy and optimal biomechanics.

In silico Immunogenicity Assessment for Sequences Containing Unnatural Amino Acids: A Method Using Existing in silico Algorithm Infrastructure and a Vision for Future Enhancements.

The in silico prediction of T cell epitopes within any peptide or biologic drug candidate serves as an important first step for assessing immunogenicity. T cell epitopes bind human leukocyte antigen (HLA) by a well-characterized interaction of amino acid side chains and pockets in the HLA molecule binding groove. Immunoinformatics tools, such as the EpiMatrix algorithm, have been developed to screen natural amino acid sequences for peptides that will bind HLA. In addition to commonly occurring in synthetic peptide impurities, unnatural amino acids (UAA) are also often incorporated into novel peptide therapeutics to improve properties of the drug product. To date, the HLA binding properties of peptides containing UAA are not accurately estimated by most algorithms. Both scenarios warrant the need for enhanced predictive tools. The authors developed an in silico method for modeling the impact of a given UAA on a peptide's likelihood of binding to HLA and, by extension, its immunogenic potential. In silico assessment of immunogenic potential allows for risk-based selection of best candidate peptides in further confirmatory in vitro, ex vivo and in vivo assays, thereby reducing the overall cost of immunogenicity evaluation. Examples demonstrating in silico immunogenicity prediction for product impurities that are commonly found in formulations of the generic peptides teriparatide and semaglutide are provided. Next, this article discusses how HLA binding studies can be used to estimate the binding potentials of commonly encountered UAA and "correct" in silico estimates of binding based on their naturally occurring counterparts. As demonstrated here, these in vitro binding studies are usually performed with known ligands which have been modified to contain UAA in HLA anchor positions. An example using D-amino acids in relative binding position 1 (P1) of the PADRE peptide is presented. As more HLA binding data become available, new predictive models allowing for the direct estimation of HLA binding for peptides containing UAA can be established.

Non-Anatomic All-Inside Arthroscopic Anterior Talofibular Ligament Repair with a High Position Anchor Shows Inferior Clinical Outcomes: A 3D-CT Based Analysis in Chronic Ankle Instability Patients

Category: Arthroscopy; Sports Introduction/Purpose: In chronic ankle instability (CAI), it is important to repair the anterior talofibular ligament (ATFL) at the anatomic origin site. However, there are limited reports on the clinical outcomes according to anatomical ATFL repair. The purpose of this study is to compare the clinical outcomes after arthroscopic ATFL repair, according to whether the anchor is fixed at an anatomic position. Methods: We performed a retrospective review of consecutive patients who underwent arthroscopic ATFL repair for CAI and were available for a minimum of 2 years follow-up. The patients were divided into three groups according to the anchor position at the distal fibula on 3-dimensional computer tomography: group A, anatomical arthroscopic ATFL repair; group S, sub- anatomical arthroscopic ATFL repair; and group N, non-anatomical arthroscopic ATFL repair. The pain (visual analogue scale [VAS]) score, foot and ankle outcome score (FAOS), and the Karlsson ankle functional score were measured as subjective outcomes. Posturographic analysis and radiologic evaluation using stress radiographs and axial view magnetic resonance imaging were performed as objective outcomes. Results: Of 96 patients, 16 were excluded based on the exclusion criteria, and 80 were evaluated (group A, n = 24; group S, n = 42; and group N, n = 14). The mean age of the patients was 34.5 years, and the mean follow-up period was 27.4 months. A between-group comparison revealed significant differences in the FAOS, Karlsson score, and fall risk evaluated by posturography at the final follow-up. Post hoc analysis revealed that group A patients showed better clinical scores in the FAOS than group N patients in all five domains (all p &lt; 0.017). Patients in groups A and S showed better Karlsson score and fall risk than those in group N (p = 0.004 and 0.013, respectively). In terms of objective outcomes, patients in groups A and S showed better outcomes in fall risk than those in group N (both p = 0.001). Conclusion: Non-anatomic ATFL repair showed inferior outcomes compared to anatomic ATFL repair. When performing arthroscopic ATFL repair, the anchor should be fixed in the anatomical position to improve prognosis.

Optimal Position of the Bone Anchor for the Internal Brace Suspensionplasty Technique for Thumb Basal Joint Arthroplasty

Ligament reconstruction and tendon interposition is a common technique for thumb basal joint arthroplasty. Recently, a variation of this technique, a suture suspensionplasty, has been introduced. The goal of our study was to assess the optimal position of the bone anchor in the thumb metacarpal. We hypothesized that an anchor placed in the radial aspect of the thumb metacarpal base would provide improved stability and resist subsidence more effectively than an ulnar-based thumb anchor. Eight fresh-frozen cadaver arms were imaged fluoroscopically in anteroposterior and lateral views centered over the thumb carpometacarpal joint before and after trapeziectomy and after the placement of radial-based and ulnar-based bone anchors. The intermetacarpal angle between the thumb and index metacarpals was measured on all images after the application of a standard force. Radial abduction, opposition, subsidence, palmar abduction, and adduction were measured. Subsidence was calculated as the percentage loss of the trapezial space. Both radially and ulnarly placed internal brace constructs allowed more radial abduction, opposition, and palmar abduction than the pretrapeziectomy constructs. They both also reduced subsidence by approximately 20% to 29% compared with the posttrapeziectomy constructs. Comparing radial to ulnar constructs, motion and subsidence were similar. There was immediate stability of the thumb with respect to axial load and subsidence after anchor placement, and this was independent of the anchor position. The position of the bone anchor in the thumb metacarpal base did not affect the range of motion. Although the device can limit subsidence, it does not appear to restrict any range of motion of the thumb, irrespective of anchor position. This cadaver study can help hand surgeons understand the effect of positioning of bone anchors when performing a specific suture suspensionplasty technique.

Localization Method and Finite Element Modelling of the Mid-Point Anchor of High-Speed Railway Distributed in Long Straight Line with Large Slope

In order to ensure the safe and reliable operation of a high-speed railway, the precise positioning of the mid-point anchor in the catenary is very important. In view of the two problems in the calculation of the mid-point anchor position of the catenary in a long ramp section, the calculation accuracy is low, and the calculation of the central anchor clamp position is lacking. In this study, the predetermined location of the mid-point anchor is chosen based on the mid-point anchor location principle and the line condition, and the range of the allowable error of the mid-point anchor setting is determined according to the predetermined position of the mid-point anchor. Secondly, by considering the impact of the line ramp and using the measured span length, the tension difference of the clue in the direction of the line is calculated. Then, the theoretical location of the mid-point anchor clamp is determined using the downhill component and the tension difference. Finally, the theoretical position of the clamp is corrected according to the setting of the dropper to obtain the corrected position of the clamp. An FEM (finite element method) of the catenary is established in ANSYS software to calculate the height difference between the messenger cable and the contact wire at the point of the mid-point anchor setting, and then the length of the mid-point anchor rope is obtained. Through the calculation of actual case data, the maximum value of the relative error of the location of the mid-point anchor obtained by this proposed method is very small compared with the actual position, which verifies the effectiveness of this method.

Optimization of Anchor Placement in TPoS MEMS Resonators: Modeling and Experimental Validation

In this paper, a semi-analytical model is derived to calculate the anchor loss of TPoS resonators operating in higher-order length extensional modes. This model provides valuable insights on the effect of order, device dimensions, position and number of anchors on the quality factor (Q) of these resonators. Results from this model are in close agreement with the FEM simulations. The optimum position, dimension, and the number of anchors to deliver the highest Q are also discussed. Predictions of the model are validated through characterization of TPoS resonators fabricated to operate at a resonant frequency of around 1 GHz with different number of anchor pairs and position. A <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$23^{rd}$ </tex-math></inline-formula> order resonator with a W/L ratio of 1.5 with three pairs of anchors placed at positions suggested by the model gave a loaded Q of 4431, which is 65% more than the conventional case where anchors are uniformly placed towards the edge, and also an improvement in the insertion loss by 5.5 dB compared to the latter. For resonators where the anchor loss is predominant, our results show that the performance can be improved by placing the anchors at the optimum position, closer to the middle of the resonator than the conventional scheme where anchors are uniformly placed towards the edge.

Solid‐Supported Tetrahydropyran‐Based Hybrid Dipeptide Catalysts for Michael Addition of Aldehydes to Nitrostyrenes

AbstractThe heterogenization of homogeneous catalysts onto a solid support is a step towards a more sustainable chemistry. The recovery and reuse of catalysts is extremely important from a practical, economic and environmental point of view. In this regards, we report a series of polymer‐supported tetrahydropyran‐based hybrid dipeptides that serve as active catalysts for the enantioselective Michael addition of aldehydes to β‐nitrostyrenes. These supported catalysts have been designed considering the optimal anchor position and orientation between the catalyst and the solid support. Additionally, the influence of the linker length on the catalytic efficiency was studied. The catalysts allowed the transformation of a variety of substrates in 76–98% yield and with 94–97% enantiomeric excess. Detailed deactivation studies have provided important information, which allows to increase the useful life of these immobilized catalysts.magnified image

O099 Position and number of anchors in hip arthroscopy labrum repair: a systematic review

Abstract Introduction Hip labral tears are reported in 22–55% of patients with hip or groin pain. Operative treatment is necessary for most cases, via hip arthroscopy with the use of suture anchors. This systematic review aims to determine the optimal number and position of anchors in hip labral repair. Methods Pubmed, Ovid &amp; Embase were searched, and 2 researchers independently screened the 1,304 results. Outcome measures such as procedures performed, number &amp; (clockface) position of anchors, failure &amp; articular involvement of anchors were extracted. Results 5 studies were included in the analysis: 1 Cross-Sectional Study (1645 Hips, mean age (MA):33.7 years), 3 Retrospective case studies (491 hips, MA:31.0) and 1 Controlled Cadaveric study (32 cadaveric hips, MA:62.7). Chi-squared statistical analysis of 323 hips found a significant difference (X2 (2, N = 323) = 17.88, p &amp;lt; .001) in the risk of articular involvement with the position of anchors at 11°-12° o’clock, 1°-2° and 3°-4°. There is an absolute risk reduction (ARR) of 19% with anchors positioned at 11°-12° compared to anchors positioned at 3°-4° (X2 (1, N=178) =15.79, p &amp;lt; .001) and an ARR of 12% with anchors at 1°-2° compared to anchors positioned at 3°-4° (X2 (1, N = 237) = 15.79, p &amp;lt; .0109). Additionally, by assessing 1645 operations it was found that for tears spanning &amp;gt;2 hours, a minimum of 2 anchors was placed. Conclusion Placement of anchors in the 3°-4° o’clock position carries the highest risk for articular involvement. Small diameter anchors and careful placement can be used to minimize articular injury. Preferable positions of anchors are 11°-12°, furthermore, for tears spanning over 2 hours, a minimum of 2 anchors was placed. Take-home message In Hip Arthroscopy labral repair, placement of anchors in the 3°-4° o’clock position carries the highest risk for articular involvement. Small diameter anchors and 2 hours. flexible anchor instrumentation can be used to minimize articular injury, furthermore, for tears spanning over 2 hours, a minimum of 2 anchors was placed.

Tailorable stimulated Brillouin scattering in a partially suspended aluminium nitride waveguide in the visible range.

Stimulated Brillouin scattering (SBS) has been widely applied in narrow line-width laser, microwave filters, optical gyroscopes, and other fields. However, most research is limited within near-infrared to mid-infrared range. This is due to the limited transparent window in most materials, such as silicon and germanium. Aluminium nitride (AlN) is a novel III-V material with a wide transparent window from 200 nm and an appropriate refractive index to confine the light. In this paper, we first validate the full-vectorial formalism to calculate SBS gain based on the measured results from a silicon platform. Compared to previous research, our model achieves higher accuracy in terms of frequency, Q factor, as well as Brillouin gain coefficient without modifying the waveguide width. It also reveals the importance of matching rotation matrix and crystalline coordinate system. Then, we investigate the SBS in a partially suspended AlN waveguide at 450 nm based on the validated method. It shows a wide tunability in frequency from 16 GHz to 32 GHz for forward SBS and a range from 42 GHz to 49 GHz for backward SBS. We numerically obtain the value of Brillouin gain of 1311 W-1m-1 when Q factor is dominated by anchor loss for forward SBS of transverse electric mode. We also find out that in the case for forward SBS of transverse-magnetic mode, anchor loss could be greatly suppressed when the node point of the selected acoustic mode matches with the position of pillar anchor. Our findings, to the best of our knowledge, pave a new way to obtain Brillouin-related applications in integrated photonic circuit within the visible range.

Paper 36: Change in Humeral Anchor Position Significantly Affects Isometry in UCL Repair: A 3-Dimensional Computer Modeling Study

Objectives:Medial ulnar collateral ligament (UCL) repair utilization is increasing in recent years, bolstered by shorter rehabilitation and satisfactory clinical outcomes. While previous literature has illustrated the importance of tunnel position on restoring graft isometry in UCL reconstruction, there remains a paucity of literature guiding anchor placement in UCL repair. Herein, we describe a 3-dimensional (3D) elbow model to measure and optimize anchor location during UCL repair.Methods:A 3D computer model of a human elbow joint was created using CT and MRI images from a single patient. The humeral and ulnar attachments of the UCL were plotted using three distinct methodologies: 1) geometric cloud mapping; 2) quantitative measurements as described by the anatomical studies by Camp et al1; and 3) Frangiamore et al2. A 3.5mm-diameter clockface was placed on each attachment site which allowed for simulation of 12 distinct, 1.75mm deviations in anchor position. The three elbow models were then ranged through 0-120 degrees of flexion at 10-degree increments, and the 3D distances were measured between the two ligament centroids. The humeral and ulnar anchors were sequentially repositioned around the clockfaces, and ligament lengths were again measured to evaluate changes in isometry. An independent t-test was performed to determine if there was a significant difference in isometry between the humeral or ulnar anchor deviations.Results:Using method 1, the UCL length at 90 degrees of elbow flexion was 26.8mm. This ligament underwent 13.6mm of total excursion for a 46.4% change in length throughout arc of motion. Method 2 produced a 19.3mm ligament that underwent 0.8mm of excursion for a 3.9% length change throughout the arc. Method 3 produced a 24.5mm ligament that underwent 2.3mm of excursion for a 9.4% length change throughout arc. Identifying ligament footprints using the quantitative anatomical measurements as described by Camp et al1 and Frangiamore et al2 produced better ligament isometry through 120 degrees of flexion (ligament length changes of 3.9% and 9.4%, respectively) when compared to using the geometric cloud technique (46.4% length change). Humeral anchor deviations produced a statistically significant increase in ligament excursion when compared to ulnar anchor deviations (p < 0.001).Conclusions:When performing UCL repair, small deviations in humeral anchor position may significantly influence graft and ligament isometry. Anchor position was most isometric while using the quantitative measurements as described in Camp et al1. Particularly when addressing detachments of the humeral footprint, surgeons should be critical of the humeral anchor position in order to restore native anatomy and optimal biomechanics.

Abstract 1374: Discovery of MHC class I and class II neoantigens in lung cancer in needle biopsy tissue samples using an optimized high-throughput workflow

Abstract Human leukocyte antigen-associated peptides, known as immunopeptides, play an essential role in adaptive immunity by activating and ensuring the specificity of T-cells. The identification and quantification of the immunopeptidome bear the potential to enable personalized treatments, especially in cancers, vaccines, infectious, and autoimmune diseases. Mass spectrometry is currently the only technology that can reliably measure and identify immunopeptide profiles of biological samples on a large scale. However, the usually high sample input amount and poor scalability are limiting. Here, we introduce a semi-automated workflow to robustly identify immunopeptides from low amounts of cultured cells and tissue samples by systematically optimizing each step of the sample preparation and acquisition. We optimized the native lysis and immunoprecipitation workflow while ensuring scalability and reproducibility. Leveraging the magnetic properties of the beads, 1,000 samples can be processed within a week by a single operator. The established sample preparation offers high reproducibility and identifications of good quality. For class-I immunopeptides, &amp;gt60% of the peptides identified are 9-mers, &amp;gt80% predicted strong binders, and the expected amino acids are enriched at the anchor positions. For class-II, &amp;gt50% of the peptides identified are 14-to-16-mers, and &amp;gt50% are predicted strong binders. Furthermore, the pipeline is highly sensitive as we could still identify over 2,800 class-I immunopeptides when processing as little as 2.5 mg fresh frozen tissue and &amp;gt9,000 class-I and &amp;gt12,000 class-II immunopeptides when preparing 10 million JY cells. Overall, the pipeline is scalable, highly reproducible, and results in high-quality identifications while supporting very limited sample input. Finally, we measured a cohort of 12 cancerous and matched healthy lung tissues from as little as 15 mg tissue, whereby we could identify &amp;gt11,000 class-I immunopeptides and &amp;gt9,000 class-II on average. For class-I, matched samples clustered together, while &amp;gt3,000 immunopeptides were upregulated in the cancer tissues, with a significant enrichment for proteins related to lung cancer. Overall, we established a scalable, efficient pipeline for cell line and tissues immunopeptidomics for class-I and II that generates high-quality identifications and that only requires small amounts of input material and is ready to shed light into immunopeptidomics heterogeneity through large-scale profiling of patients. Citation Format: Ilja E. Shapiro, Luca Raess, Marco Tognetti, Tikira Temu, Oliver M. Bernhardt, Yuehan Feng, Roland Bruderer, Lukas Reiter. Discovery of MHC class I and class II neoantigens in lung cancer in needle biopsy tissue samples using an optimized high-throughput workflow [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1374.

Abstract 5639: Computational prediction of MHC anchor locations guide neoantigen prediction and prioritization

Abstract Neoantigens are novel peptide sequences resulting from somatic mutations in tumors that upon loading onto major histocompatibility complex (MHC) molecules allow recognition by T cells. Accurate neoantigen identification is thus critical for designing cancer vaccines and predicting response to immunotherapies. Neoantigen identification and prioritization relies on correctly inferring whether the presenting peptide sequence can successfully induce an immune response. As the majority of somatic mutations are SNVs, changes between wildtype and mutant peptide are subtle and require cautious interpretation. An important, yet underappreciated, variable in neoantigen-prediction pipelines is the mutation position within the peptide relative to its anchor positions for the patient’s specific HLA alleles. While a subset of peptide positions are presented to the T-cell receptor for recognition, others are responsible for anchoring to the MHC, making these positional considerations critical for predicting T-cell responses. However, a systematic method for determining anchor locations for the wide range of HLA alleles present in the population and application of these to evaluate MT/WT peptide pairs arising in tumors has not been reported. As a result, many neoantigen studies have either failed to adequately consider this crucial factor or have used conventional assumptions to guide their neoantigen identification process. Here, we provide a computational workflow for predicting anchor locations for a wide range of HLA alleles, using a reference dataset generated from clinical and The Cancer Genome Atlas (TCGA) patient samples. We calculated high probability anchor positions for different peptide lengths for over 300 common HLA alleles. Analysis of these results showed clusters of different anchor trends among the HLA alleles analyzed. A subset of these HLA anchor results were orthogonally validated using protein crystallography structures. Analysis of 923 tumor samples showed that 7-41% of neoantigen candidates were potentially misclassified in the neoantigen selection process and can be rescued using allele-specific knowledge of anchor positions. These anchor predictions are currently undergoing experimental validation using both peptide-MHC stability assays as well as fluorescence-based competition binding assays. By incorporating our anchor prediction results into neoantigen prediction pipelines, such as pVACtools, we hope to formalize and streamline the identification process for relevant clinical studies. Citation Format: Huiming Xia, Joshua McMichael, Michelle Becker-Hapak, Onyinyechi C. Onyeador, Rico Buchli, Ethan McClain, Patrick Pence, Suangson Supabphol, Megan M. Richters, Anamika Basu, Cody A. Ramirez, Cristina Puig-Saus, Kelsy C. Cotto, Jasreet Hundal, Susanna Kiwala, S. Peter Goedegebuure, Tanner M. Johanns, Gavin P. Dunn, Antoni Ribas, Christopher A. Miller, William Gillanders, Todd A. Fehniger, Obi L. Griffith, Malachi Griffith. Computational prediction of MHC anchor locations guide neoantigen prediction and prioritization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5639.

Simultaneous prediction of antibody backbone and side-chain conformations with deep learning.

Antibody engineering is becoming increasingly popular in medicine for the development of diagnostics and immunotherapies. Antibody function relies largely on the recognition and binding of antigenic epitopes via the loops in the complementarity determining regions. Hence, accurate high-resolution modeling of these loops is essential for effective antibody engineering and design. Deep learning methods have previously been shown to effectively predict antibody backbone structures described as a set of inter-residue distances and orientations. However, antigen binding is also dependent on the specific conformations of surface side-chains. To address this shortcoming, we created DeepSCAb: a deep learning method that predicts inter-residue geometries as well as side-chain dihedrals of the antibody variable fragment. The network requires only sequence as input, rendering it particularly useful for antibodies without any known backbone conformations. Rotamer predictions use an interpretable self-attention layer, which learns to identify structurally conserved anchor positions across several species. We evaluate the performance of the model for discriminating near-native structures from sets of decoys and find that DeepSCAb outperforms similar methods lacking side-chain context. When compared to alternative rotamer repacking methods, which require an input backbone structure, DeepSCAb predicts side-chain conformations competitively. Our findings suggest that DeepSCAb improves antibody structure prediction with accurate side-chain modeling and is adaptable to applications in docking of antibody-antigen complexes and design of new therapeutic antibody sequences.

Research on Intelligent Detection Algorithm of the Single Anchored Mooring Area for Maritime Autonomous Surface Ships

Mooring area detection represents one of the key technological problems that must be solved in the development of Maritime Autonomous Surface Ships (MASS). In view of the lack of research on the current detection methods for ship mooring area, a new intelligent detection algorithm of the single anchored mooring area for MASS was proposed in this study, aiming at improving the detection ability and accuracy of the MASS mooring area. Firstly, the laws of short period swinging motion, long period circumferential motion and reciprocating motion in the radial direction of an anchoring ship were summarized. Secondly, an anchorage circle radius model and safety distance model between the anchor positions were established and various constrains were considered including ship type, ship particulars, draft, safety impact caused by other ships passing through the anchoring ship. Thirdly, the Monte-Carlo stochastic simulation method was used to measure the mooring area, which can detect the anchor position intelligently. Finally, a case study on MATLAB demonstrated that the proposed intelligent detection algorithm for MASS is effective under various marine scenarios. The results enrich the theory of MASS mooring area detection; therefore, the algorithm has great potential to be equipped on MASS in the future.

Establishing the correspondences between 2D UWB positions and image coordinates

Ultra wide band (UWB) positioning system and camera are two types of sensors which records positions and images respectively. In many applications, it is expected to fuse the data obtained by the two types of sensors in two different coordinate systems. In this work, we study the problem of establishing the correspondences between 2D UWB positions and image coordinates of a camera. We propose a simple yet effective method which requires simple apparatus and does not need to know in advance the positions of the UWB anchors in camera frame. Experimental results have demonstrated the effectiveness of proposed method.

Sex of first child: like migrant father, like son

Abstract As males in Mexico have the authority in households and dominate migration flows to the US, this paper argues that having a son as the first child provides an early additional candidate for the anchor position in Mexico and for migration trips to the US, making households better off. Fathers with longer migration experiences have higher expectations for future migration trips and stronger incentives to manipulate the sex of their first child. The empirical analysis confirms that by presenting positive effects of fathers’ previous migration experiences on the probability of having a son as a firstborn child, though abortions are widely illegal in Mexico.

Nonanatomic All-Inside Arthroscopic Anterior Talofibular Ligament Repair With a High-Position Anchor versus Anatomic Repair: An Analysis Based on 3D CT

Background: In patients with chronic ankle instability, it is important to repair the anterior talofibular ligament (ATFL) at the anatomic origin site. However, there are limited reports on the clinical outcomes according to anatomic ATFL repair. Purpose: To compare the clinical outcomes after arthroscopic ATFL repair according to whether the anchor is fixed at an anatomic position. Study Design: Cohort study; Level of evidence, 3. Methods: We performed a retrospective review of consecutive patients who underwent arthroscopic ATFL repair for chronic ankle instability and were available for a minimum 2-year follow-up. The patients were divided into 3 groups according to the anchor position at the distal fibula on 3-dimensional computed tomography: anatomic arthroscopic ATFL repair (anatomic group), subanatomic arthroscopic ATFL repair (subanatomic group), and nonanatomic arthroscopic ATFL repair (nonanatomic group). The visual analog scale for pain, Foot and Ankle Outcome Score (FAOS), and Karlsson ankle functional score were measured as subjective outcomes. Posturographic analysis and radiologic evaluation using stress radiographs and axial view magnetic resonance imaging were performed as objective outcomes. Results: Of 96 patients, 16 were excluded per the exclusion criteria, and 80 were evaluated (anatomic group, n = 24; subanatomic group, n = 42; nonanatomic group, n = 14). The mean age of the patients was 34.5 years, and the mean follow-up period was 27.4 months. A between-group comparison revealed significant differences in FAOS, Karlsson score, and fall risk evaluated by posturography at the final follow-up. Post hoc analysis revealed that the anatomic group had better clinical scores on the FAOS than did the nonanatomic group in all 5 domains (all P < .017). Patients in the anatomic and subanatomic groups had better Karlsson scores and fall risk than those in the nonanatomic group (P = .004 and P = .013, respectively). In terms of objective outcomes, patients in the anatomic and subanatomic groups had better outcomes in fall risk than did those in the nonanatomic group (both P = .001). There were no differences in clinical scores and objective outcomes between the anatomic and subanatomic groups. Conclusion: Nonanatomic ATFL repair showed inferior outcomes when compared with anatomic ATFL repair. When arthroscopic ATFL repair is performed, the anchor should be fixed in the anatomic position to improve prognosis.

Opening opportunities for Kd determination and screening of MHC peptide complexes

An essential element of adaptive immunity is selective binding of peptide antigens by major histocompatibility complex (MHC) class I proteins and their presentation to cytotoxic T lymphocytes. Using native mass spectrometry, we analyze the binding of peptides to an empty disulfide-stabilized HLA-A*02:01 molecule and, due to its unique stability, we determine binding affinities of complexes loaded with truncated or charge-reduced peptides. We find that the two anchor positions can be stabilized independently, and we further analyze the contribution of additional amino acid positions to the binding strength. As a complement to computational prediction tools, our method estimates binding strength of even low-affinity peptides to MHC class I complexes quickly and efficiently. It has huge potential to eliminate binding affinity biases and thus accelerate drug discovery in infectious diseases, autoimmunity, vaccine design, and cancer immunotherapy.

Parameter Estimation and Tracking of an Expandable Cable-Driven Parallel Mechanism for Minimally Invasive Interventions

Conventional catheter-based procedures suffer from inaccurate device steering, and navigation limitations as the long and flexible devices are manipulated remotely from outside the patient body. A recently developed approach aims to overcome these limitations by using an expandable cable-driven parallel mechanism for local device manipulation and tracking relative to the anatomy. However, as the frame of this system is flexible and may be constrained by unknown anatomical constraints inside the patient body, accurate system identification is a key and critical step which would ultimately determine the accuracy in device steering and tracking. In this paper, we present an optimization approach to identify the parameters of an expandable cable-driven parallel mechanism deployed in an unknown environment, merely based on measurements of the cable length variations that would be available outside the patient body. We have verified and validated the proposed approach in terms of accuracy in the prediction of the frame shape and cable anchor locations, as well as its tracking accuracy. Both simulations and experimental studies have been performed, and we have demonstrated that the proposed method allows for rapid frame shape and anchor position estimation with unknown anatomical constraints and permits localized device tracking and steering with submillimeter accuracy.