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Abstract Optical metasurfaces, planar artificial media capable of controlling light propagation, are transitioning from laboratory curiosity to commercial applications. This shift requires advanced meta-atom and metasurface designs, considering manufacturability and enhancing optical performance with post-processing algorithms. Artificial-Intelligence(AI), particularly machine-learning(ML) and optimization, offers solutions to these demands. This perspective systematically reviews AI’s potential impact in three critical areas: AI-enabled metasurface design-for-manufacturing(DFM), design beyond the classical local phase approximation, and AI-empowered computational backend.

Background: Reproducing the medial pivot pattern after total knee arthroplasty (TKA) is known to improve patient satisfaction. However, the factors affecting the postoperative medial pivot pattern in TKA are controversial. The purpose of this study was to examine the factors affecting the postoperative medial pivot pattern in posterior-stabilized TKA. Methods: This study involved 30 cases with knee osteoarthritis who underwent primary posterior-stabilized TKA. The preoperative and postoperative kinematics were measured using a computed tomography–free navigation system, and the patients were divided into the following 2 groups: the medial pivot pattern (MP) group and non–medial pivot pattern (non-MP) group. In addition, we measured each of the following angles on X-ray films (preoperative and postoperative femorotibial angle, hip-knee-ankle angle, mechanical lateral distal femoral angle, medial proximal tibial angle). We examine the factors affecting the postoperative medial pivot pattern. Results: There were 14 cases in the MP group and 16 cases in the non-MP group at the preoperative knee kinematic assessment and 17 cases in the MP group and 13 cases in the non-MP group at the postoperative knee kinematic assessment. The preoperative kinematic pattern was conserved after the surgery at a rate of 76.7%. The postoperative MP-group showed a significantly smaller preoperative femorotibial angle and hip-knee-ankle and a significantly smaller postoperative mechanical lateral distal femoral angle and medial proximal tibial angle in comparison to the postoperative non-MP group. Conclusions: Preoperative kinematics and postoperative mechanical lateral distal femoral angle and medial proximal tibial angle may be important factors that affect the postoperative medial pivot pattern.

Summary: Evaluating the serum cross-neutralization responses after breakthrough infection with various SARS-CoV-2 variants provides valuable insight for developing variant-proof COVID-19 booster vaccines. However, fairly comparing the impact of breakthrough infections with distinct epidemic timing on cross-neutralization responses, influenced by the exposure interval between vaccination and infection, is challenging. To compare the impact of pre-Omicron to Omicron breakthrough infection, we estimated the effects on cross-neutralizing responses by the exposure interval using Bayesian hierarchical modeling. The saturation time required to generate saturated cross-neutralization responses differed by variant, with variants more antigenically distant from the ancestral strain requiring longer intervals of 2–4 months. The breadths of saturated cross-neutralization responses to Omicron lineages were comparable in pre-Omicron and Omicron breakthrough infections. Our results highlight the importance of vaccine dosage intervals of 4 months or longer, regardless of the antigenicity of the exposed antigen, to maximize the breadth of serum cross-neutralization covering SARS-CoV-2 Omicron lineages.

Summary: The immune responses to SARS-CoV-2 variants in COVID-19 cases are influenced by various factors including pre-existing immunity via vaccination and prior infection. Elucidating the drivers for upgrading neutralizing activity to SARS-CoV-2 in COVID-19 cases with pre-existing immunity will aid in improving COVID-19 booster vaccines with enhanced cross-protection against antigenically distinct variants, including the Omicron sub-lineage BA.4/5. This study revealed that the magnitude and breadth of neutralization activity to SARS-CoV-2 variants after breakthrough infections are determined primarily by upper respiratory viral load and vaccination-infection time interval. Extensive neutralizing breadth, covering even the most antigenically distant BA.4/5, was observed in cases with higher viral load and longer time intervals. Antigenic cartography depicted a critical role of the time interval in expanding the breadth of neutralization to SARS-CoV-2 variants. Our results illustrate the importance of dosing interval optimization as well as antigen design in developing variant-proof booster vaccines.

Abstract Background Patients with a temporary pacemaker (TPM) for bradycardias are required to maintain bedrest until permanent pacemakers (PPMs) are implanted because of the development of Adams–Stokes syndrome, worsening heart failure, or complications associated with TPMs is anticipated. However, bedrest may be detrimental in patients because it leads to disuse syndrome. This study examined whether bedrest could decrease the incidence of cardiovascular events or complications associated with TPMs in patients waiting for PPM implantation. Methods We conducted a retrospective cohort study on 88 patients who had emergency hospitalization for the treatment of bradycardias, and a TPM was inserted during the waiting period before PPM implantation. We divided patients into two groups according to whether they underwent bedrest (Bedrest Group) or not (Ambulation Group) during the period that patients were supported with TPM. We evaluated whether bedrest was a predictor of adverse events using a logistic regression analysis. Results Adverse events occurred in 31 patients (35%). In the univariate analysis, there was no significant difference in the incidence of adverse events between the Bedrest and Ambulation Groups (39% vs. 29%). In the logistic regression analysis, bedrest was not a predictor of adverse events (odds ratio, 1.40; 95% confidence interval, 0.53‐3.68, P = .497). Conclusions In patients with TPMs for bradyarrhythmias during the waiting period for PPM implantations, bedrest might not prevent adverse events, such as cardiovascular events and complications associated with TPMs.

Abstract Background Hallux valgus deformity has been reported to be associated with increased postural sway. However, the direction and magnitude of postural sway associated with hallux valgus remain inconclusive. We assessed the association between hallux valgus deformity and postural sway using a force plate. Methods The subjects were 169 healthy volunteers, > 40 years old (63 males, 106 females, average age: 66.0 ± 12.4 years old), who took part in an annual medical examination. We investigated the photographic hallux valgus angle (°), total trajectory length of the gravity center fluctuation (mm), area of the center of pressure (mm2), mediolateral and anteroposterior postural sway (mm) in a standing position with 2-legged stance and eyes open, hallux pain (Numerical Rating Scale), trunk and lower limb muscle mass (kg). We classified the subjects into a hallux valgus group (n = 44, photographic hallux valgus angle of 1 or both feet ≥ 20°) and a no hallux valgus group (n = 125, photographic hallux valgus angle of both feet

In recent years, the popularity of fiber-reinforced materials in the aerospace and automobile industries grows due to their high stiffness-to-weight ratios. Thus, a structural design methodology is needed to bring out the celebrated mechanical properties of these materials as much as possible. From this aspect, topology optimization has been considered as an effective method for such a method. As a natural consequence of the trend, intensive researches on topology optimization methodologies to handle the anisotropy of fibrous materials has been conducted. However, these researches were limited to the static problem, i.e., compliance minimization problem. In the present work, we propose a dynamic topology optimization method for fiber-reinforced materials which is capable of optimizing element-by-element orientations. Our method builds upon a framework of SIMP type topology optimization and can optimize each element’s density and orientation as design variables. Numerical analysis is done by Finite Element Method and Method of Moving Asymptotes is implemented as an updating scheme of design variables. The effectiveness of our method is validated through the eigenfrequency maximization problem and eigenfrequency gap maximization problem.

The stalk domain of influenza virus envelope glycoprotein hemagglutinin (HA) constitutes the axis connecting the head and transmembrane domains, and plays pivotal roles in conformational rearrangements of HA for virus infection. Here we characterized molecular interactions between the anti-HA stalk neutralization antibody F11 and influenza A(H1N1)pdm09 HA to understand the structural basis of the actions and modifications of this antibody. In silico structural analyses using a model of the trimeric HA ectodomain indicated that the F11 Fab fragment has physicochemical properties, allowing it to crosslink two HA monomers by binding to a region near the proteolytic cleavage site of the stalk domain. Interestingly, the F11 binding allosterically caused a marked suppression of the structural dynamics of the HA cleavage loop and flanking regions. Structure-guided mutagenesis of the F11 antibody revealed a critical residue in the F11 light chain for the F11-mediated neutralization. Finally, the mutagenesis led to identification of a unique F11 derivative that can neutralize both F11-sensitive and F11-resistant A(H1N1)pdm09 viruses. These results raise the possibility that F11 sterically and physically disturbs proteolytic cleavage of HA for the ordered conformational rearrangements and suggest that in silico guiding experiments can be useful to create anti-HA stalk antibodies with new phenotypes.

In the present work, the four-point bending loading fatigue properties of a heterogeneously distributed grain size microstructure consolidated from Ti-6Al-4V alloy powder are studied. The microstructure involved here, a so-called “harmonic structure”, possesses quasi-spherical large grain regions (“cores”) embedded in a continuous fine grain region (“shell”). Unlike the previous reports dealing with this issue, the effect of the specimen size on the fatigue characteristics is also probed, since two distinct specimen configurations are considered. Furthermore, the obtained experimental data are compared with the corresponding fatigue results derived from homogeneous coarse grain counterparts. Contrary to homogeneous structure material, discrepancies on both the fatigue strength and the fatigue crack initiation aspects are found for the harmonic structure material. Consequently, the present work aims to clarify the underlining phenomena involved in the specimen size effect detected for Ti-6Al-4V designed in the harmonic structure. A less active interface surface between the core and the shell combined with a wider critical volume in the large size specimen should be the main reasons of the fatigue strength discrepancy.

Manufacturing industry tends to high-mix low-volume production, and it is strongly required to shorten the manufacturing lead time of products. In the field of machining, complex machining by means of multi-tasking machine tools attracts the attention. However, the machining operation is not easy to understand due to the highly complicated machine tool structure. Thus, NC programming for multi-tasking machine tools spends much time and labor. Therefore, it is required for CAPP/CAM system to minimize the effort of NC programming in terms of easily realizing highly efficient machining. Though there are some CAM systems for a multi-tasking machine tool, they generally need long operating time caused by the manual allocation of parts to generate tool paths. In this study, novel machining features are proposed for complex machining by means of multi-tasking machine tools. Proposed machining features deal with several alternative machining methods and contribute directly to the suitable allocation of machining order. Therefore, process planning can be conducted depending on machining strategy considering available cutting tools and the structure of a multi-tasking machine tool. From the result of case studies, it is found that the proposed machining features show the possibility to reduce the effort and to decide the effective machining process of complex machining.

Introduction: Due to the difficulty in performing detailed mapping around the tricuspid annulus and the high occurrence of mechanical trauma during the procedure, the outcome of right-sided accessory pathway (AP) ablation still has a relatively high primary failure and recurrence rate. Methods and Results: Six patients with right free-wall APs underwent electroanatomical mapping. The AP had retrograde unidirectional conduction in 3 patients, anterograde unidirectional conduction in 1 patient, and bidirectional conduction in 2 patients. The right atrial (RA) activation map was constructed during right ventricular (RV) pacing (n = 5), and the RV activation map was constructed during RA pacing (n = 3). During mapping, the AP conduction was interrupted by catheter mechanical trauma in 3 patients. The first RF application successfully eliminated the AP conduction within 2 seconds in 3 patients with concealed pathways. In the remaining 3 patients, rescue RF energy was delivered at the tagged bump site on the map. The mean procedure time was 214 ± 77 minutes, and mean fluoroscopy time 63 ± 23 minutes. No recurrence occurred during 12 ± 3.2 months of followup in any of the patients. Conclusions: With the guidance of an electroanatomical mapping system, right-sided accessory pathways can be satisfactorily eliminated without later recurrence.

The H ^− ion beam intensity required for high-energy and high-intensity proton accelerators is continuously increasing. The required 95%-beam transverse normalized root mean square emittance ( ε _95%rnms _x _/ _y ) of the beam is around 0.25 π mm mrad for all accelerators. The Japan Proton Accelerator Complex (J-PARC) 400 MeV linear accelerator (LINAC) succeeded in accelerating the world’s highest-class H ^− ion beam of 50 mA with a cesiated RF-driven H ^− ion source. This was achieved by increasing the beam brightness through the following measures: (1) 45°-tapered plasma electrode (PE) with a 16 mm thickness to increase beam intensity by 56%, (2) continuous-wave igniter plasma driven by 50 W 30 MHz RF to reduce hydrogen pressure in the plasma chamber (PCH) by 50% and beam loss in low-energy beam transport by 12%, compared with that by the commonly used 300 W 13.56 MHz RF, (3) axial magnetic-field correction around the PE beam aperture to increase beam intensity by a maximum of 15%, (4) operation at a low PE temperature ( T _PE ) of about 70 °C to reduce ε _95%nrms _x _/ _y by 27%, (5) suitable beam apertures of the plasma and the extraction electrodes to increase beam intensity by a maximum of 7% and to reduce ε _95%nrms _x _/ _y by more than 4%, (6) argon/nitrogen elimination and 39% filter-field reduction to reduce ε _95%nrms _x _/ _y by 9% and the required 2 MHz RF power by around 30%, (7) eight-hours conditioning with a 50 kW 2 MHz RF and a 5% (1 ms × 50 Hz) duty factor to reduce ε _95%nrms _x _/ _y by 15%, and (8) slight water molecules (H _2 Os) feeding in hydrogen to avoid ε _95%nrms _x _/ _y increase by 72% and divergence angle expansion by 50%. In the studies, we investigated principally the 66 mA H ^− ion beams extracted from the source in order to achieve a 50 mA beam at the J-PARC LINAC exit regardless of the beam’s brightness. Consequently, the source can produce the required beam for a 60 mA J-PARC LINAC operation, since the world’s brightest-class beam with the ε _95%nrms _x _/ _y of 0.23 π mm mrad and beam intensity of 66 mA is successfully produced through the above measures.

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.

The first annular-ring coupled structure (ACS) cavity for the Japan Proton Accelerator Research Complex (J-PARC) linac has been developed in order to confirm and establish its fabrication processes. This cavity includes 34 accelerating cells, which is 3.4 times as many as the prototype cavity (buncher) of the J-PARC ACS. The cell frequencies before brazing were tuned within the required accuracies. After brazing, the accelerating- and coupling-mode frequencies were 972.19 and 972.63 MHz on average, respectively, which were higher than the operating frequency of 972 MHz. Although the accelerating-mode frequency can be corrected to 972 MHz using adjustable plungers, these frequency errors adversely affected the on-axis electric field. This cavity was successfully conditioned up to 1.6 MW. This power corresponds to an accelerating field of 4.7 MV/m, which is 10% higher than the design value of 4.2 MV/m. In order to find the issue caused by the excited coupling cells, this cavity was also conditioned at the higher and lower frequencies that were detuned from the operating frequency of 972 MHz. Here we present the frequency tuning processes, the low-level rf measurements, and the high-power test results. We also discuss the most reasonable scenario for frequency tuning in future work.

Infectious virus shedding from individuals infected with severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is used to estimate human-to-human transmission risk. Control of SARS-CoV-2 transmission requires identifying the immune correlates that protect infectious virus shedding. Mucosal immunity prevents infection by SARS-CoV-2, which replicates in the respiratory epithelium and spreads rapidly to other hosts. However, whether mucosal immunity prevents the shedding of the infectious virus in SARS-CoV-2-infected individuals is unknown. We examined the relationship between viral RNA shedding dynamics, duration of infectious virus shedding, and mucosal antibody responses during SARS-CoV-2 infection. Anti-spike secretory IgA antibodies (S-IgA) reduced viral RNA load and infectivity more than anti-spike IgG/IgA antibodies in infected nasopharyngeal samples. Compared with the IgG/IgA response, the anti-spike S-IgA post-infection responses affected the viral RNA shedding dynamics and predicted the duration of infectious virus shedding regardless of the immune history. These findings highlight the importance of anti-spike S-IgA responses in individuals infected with SARS-CoV-2 for preventing infectious virus shedding and SARS-CoV-2 transmission. Developing medical countermeasures to shorten S-IgA response time may help control human-to-human transmission of SARS-CoV-2 infection and prevent future respiratory virus pandemics. [ABSTRACT FROM AUTHOR]

A 76 y/o women presented with 2 different types of premature ventricular contractions (VPCs 1 and 2) arising from the right ventricular outflow tract (RVOT). Catheter ablation (CA) eliminated PVC1 at the earliest activation site (EAS), but thereafter another PVC morphology (PVC3) appeared. Small potentials preceding the local potential were broadly exhibited from the RVOT's supero-anterior region to the EAS during PVC3. Point CA targeting such pre-potentials failed. Transverse-linear CA with a line connecting sites with such pre-potentials eliminated both PVCs 3 and 2. In cases with broadly spreading preferential pathways, extensive CA might be needed to eliminate the PVCs.