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In industrial applications such as numerical control machine tools and robots, high-speed positioning operations are always required to improve productivity. However, high-speed positioning operations cause residual vibration owing to the inertial force of the driven object. To suppress this vibration, researchers have proposed adjusting the time constant and/or applying filters for the positioning command; these are generally applied in the field. However, the acceleration and deceleration time increases when the conventional vibration-suppression methods are applied to suppress lower frequency vibration. The purpose of this study was to establish a design method for positioning commands that minimizes the residual vibration and positioning time. A method to eliminate the natural frequency component was applied. This method is based on the principle that when a specific natural frequency component of an external force is reduced to zero, the natural frequency component of the system will not oscillate. Although the approach can be used to design positioning commands with any positioning time, for actual systems, the torque limitation of motors should be considered because it limits the minimum positioning time. Therefore, in this study, a positioning command that can minimize the positioning time and residual vibration was designed based on the formulated relationships between positioning time and maximum acceleration of positioning command. The effectiveness of this method was verified using an experimental system with torsional beams. We confirmed that the positioning commands designed using the proposed method can minimize residual vibration and positioning time.

To improve the productivity of the machining process, it is crucial to minimize non-productive time during the manufacturing process. For instance, a significant amount of time is often spent troubleshooting issues on-site when machining failures occur, which reduces overall productivity as the machine remains idle during this period. Recently, using virtual environments constructed in computer systems to predict and resolve such problems has become increasingly popular. This approach, often referred to as a “digital twin,” can be highly effective in addressing issues. However, accurately predicting physical phenomena in a virtual environment can be challenging, requiring considerable effort to ensure the virtual model correctly represents real-world behavior. This study presents a technique for simulating coupled vibrations between machine tool dynamics and cutting forces using MATLAB/Simulink, a widely used commercial software. Machine tool dynamics are modeled with the “Simscape Multibody” function, which allows the construction of a multi-body dynamics model by defining mass, inertia, and constraint conditions. Cutting forces and machined surface geometry are calculated through Boolean operations between two geometric shapes represented by polygonal models. Self-excited chatter vibrations are simulated as an example of coupled vibrations, and actual cutting tests are conducted to validate the accuracy of the simulated results. A stability lobe diagram of the chatter vibrations is also generated based on measured and simulated frequency responses. The results demonstrate that the constructed model can accurately predict machining stability and cutting forces.

Characteristics of the coupling system influence the characteristics of entire machines, such as ball screw feed drive systems. However, quantitatively evaluating the characteristics of coupling systems is difficult because coupling systems have frictional contact surfaces that exhibit nonlinear characteristics. Hence, effective evaluation and analysis methods have not been proposed, and factors that influence the characteristics have not been investigated. In this study, the influences of contact characteristics between shaft and borehole surfaces are investigated. The characteristics of several samples were evaluated by measuring frequency responses, and it was found that the stiffness and damping of the system varied with the fixing torque and geometry of the clamp hub. It is assumed that this phenomenon is attributable to the change of the contact surface pressure, which depends on the fixing torque and geometry of the clamp hubs. Concerning the stiffness, in this study, a simple model considering the real contact area to calculate the relationship between the contact surface pressure and contact stiffness was constructed. Results obtained by applying the model were compared with experimental results, and the proposed model was confirmed to be representative of the influences of the fixed torque and coupling clamp hub bore diameter.

Background/Objectives: In Japan, evidence on catecholamine syringe exchange methods is limited, with practices varying across facilities and individuals. In this study, we aimed to determine the effect of the catecholamine syringe exchange method on blood pressure variability in intensive care unit patients. Methods: We retrospectively analyzed 119 patients (308 syringe exchanges) who underwent catecholamine syringe exchange between 1 April 2020 and 31 March 2022. Patient characteristics for the double-pumping changeover (DPC) and quick syringe changeover (QC) groups were matched and compared using propensity scores. A sub-analysis focused on patients with severe shock with systolic blood pressures ≤ 90 mmHg. Logistic regression analysis was used to examine factors influencing blood pressure variability during the catecholamine syringe changeover. Results: Neither propensity score matching nor the sub-analysis for patients with shock revealed significant differences in the coefficient of variation or absolute systolic/diastolic/mean blood pressure within 15 min of syringe exchange in the two groups. Logistic regression revealed that age was the sole risk factor affecting blood pressure variability during syringe changeover (odds ratio: 1.018, 95% confidence interval: 1.001–1.036), while syringe changeover methods did not contribute to circulating variability (odds ratio: 1.186, 95% confidence interval: 0.672–2.092). Conclusions: Differences between the DPC and QC methods did not significantly affect blood pressure variability during catecholamine syringe changeovers. However, in older adult patients, catecholamine syringe changeover may be more likely to cause blood pressure variability.

Angiopoietin-like protein 4 (ANGPTL4) is a multifunctional protein, playing roles in glucose and lipid metabolism, inflammation, angiogenesis, and tumorigenesis. Recent research suggests that ANGPTL4 is induced by hypoxia and is a useful diagnostic or prognostic marker for various cancers. However, it remains unclear whether ANGPTL4 expression influences prostate cancer. Here we examined the biological and clinical relevance of ANGPTL4 expression in prostate cancer. Firstly we examined ANGPTL4 expression in the prostate cancer cell lines LNCaP and LNCaP/CH incubated at 1% O2 for at least 6 months. We compared cellular proliferation, migration, and ANGPTL4 secretion in a culture medium between these cell lines. In addition, we investigated the effect of various concentrations of recombinant ANGPTL4 protein (rANGPTL4) on cellular proliferation and intracellular signaling pathways. Moreover, we used ANGPTL4 knockdown by RNA interference to investigate the influence of ANGPTL4 expression on these cell lines. Finally, we investigated the correlation between ANGPTL4 expression in prostate cancer specimens and clinicopathological parameters using immunohistochemistry. Our data suggested that the expression of ANGPTL4 in hypoxic conditions was 14.4-fold higher than that in normoxic condition. ANGPTL4 secretion in the culture medium increased 7.0-fold. In addition, rANGPTL4 increased cellular proliferation 1.72-fold via Akt activation. Moreover, ANGPTL4 knockdown decreased cell growth and its secretion by 25.7 and 41.4%, respectively, compared with the control. A multivariate analysis showed that positive ANGPTL4 expression in the resected specimens was an independent prognostic indicator of biochemical recurrence (P=0.03, hazard ratio = 2.02). Our results show that ANGPTL4 is induced by hypoxia and promotes cancer progression via the activated PI3K/Akt pathway. Moreover, ANGPTL4 can be used as a prognostic marker for prostate cancer patients undergoing radical prostatectomy.

Articulated robots are widely used in industries because they can perform manufacturing tasks with complicated movements. Higher speed and accuracy of motions are always required to improve the quality and productivity of products. The vibration characteristics of the robots are an important factor to achieve higher speed and accuracy motions. Robots are increasingly being used for machining. The vibration characteristics must also be considered when designing proper cutting conditions for the machining. To design control and cutting strategies for higher speed and accuracy motions or higher productivity of the machining process, it is effective to investigate the vibration characteristics of the robot and develop a mathematical model which can represents the vibration characteristics. The aim of this study is to investigate the vibration characteristics of an architectural robot and develop a mathematical model which can represent the dynamic behavior of the robot. To achieve this, vibration mode of an industrial architectural robot is analyzed based on measured frequency characteristics. According to the results of the modal analysis, it was clarified that the axial and angular stiffness of bearings of each joint of the robot has a significant impact on the vibration characteristics. Therefore, in this study, a mathematical model of the robot is developed considering the joint bearing stiffness. The mathematical model that also considers the kinematics of the robot, stiffness of reduction gears, control system for motors, and disturbance, such as friction and gravity, is introduced into the model. The control system is precisely modeled based on actual control algorithm in accordance with the implemented source codes. Although mass and inertia of the links are obtained from the 3D-CAD model, stiffness and damping parameters of the bearings and reduction gears are identified by matching the measured and simulated frequency responses. It has been confirmed that the model can adequately represents the vibration mode of the actual robot. Circular motion tests were performed to verify the model. Motion trajectories of the end effector were measured and simulated. As a result, it has been confirmed that the developed model is effective to analyze the dynamic behaviors.

This study proposes an identification and compensation method for the geometric errors of the rotary axes in five-axis machining centers, based on the on-machine measurement results of the machined workpiece. Geometric errors can be identified from the shape geometry of the workpiece machined by five-axis motions because the influence of the errors appears on the shape geometry. An observation equation can be obtained based on the geometric error model and machined shape. The actual geometric errors can be identified by the least square matching of the measured and simulated machined shapes. In order to confirm the effectiveness of the proposed method, an actual cutting test and a simulation are performed. Based on their results, it is confirmed that the proposed method can successfully identify the geometric errors in the simulation. However, these errors cannot be identified in the experiments because a few of them do not have sufficient influences onto the machined shape. On the other hand, although the geometric errors cannot be correctly identified, it is confirmed that the they can be adequately compensated for based on the identified errors in both the simulation and experiment.

For the creation of a successful antibody–drug conjugate (ADC), both scientific and clinical evidence has indicated that highly toxic anticancer agents (ACA) should be conjugated to a monoclonal antibody (mAb) to administer a reasonable amount of ADC to patients without compromising the affinity of the mAb. For ordinary ACA, the conjugation of a mAb to ACA‐loaded micellar nanoparticles is clinically applicable. Tissue factor (TF) is often overexpressed in various cancer cells and tumor vascular endothelium. Accordingly, anti‐TF‐NC‐6300, consisting of epirubicin‐incorporating micelles (NC‐6300) conjugated with the F(ab')2 of anti‐TF mAb was developed. The in vitro and in vivo efficacy and pharmacokinetics of anti‐TF‐NC‐6300 were compared to NC‐6300 using two human pancreatic cancer cell lines, BxPC3 (high TF expression) and SUIT2 (low TF expression), and a gastric cancer cell line, 44As3 (high TF expression). The intracellular uptake of epirubicin was faster and greater in BxPC3 cells treated with anti‐TF‐NC‐6300, compared with NC‐6300. Anti‐TF‐NC‐6300 showed a superior antitumor activity in BxPC3 and 44As3 xenografts, compared with NC‐6300, while the activities of both micelles were similar in the SUIT2 xenograft. A higher tumor accumulation of anti‐TF‐NC‐6300 compared to NC‐6300 was seen, regardless of the TF expression levels. However, anti‐TF‐NC‐6300 appeared to be localized to the tumor cells with high TF expression. These results indicated that the enhanced antitumor effect of anti‐TF‐NC6300 may be independent of the tumor accumulation but may depend on the selective intratumor localization and the preferential internalization of anti‐TF‐NC‐6300 into high TF tumor cells. Considering its possible clinical use, our anti‐TF‐NC‐6300 may continue to exert a high antitumor activity despite the existence of the tumor stromal barrier, since anti‐TF‐NC‐6300 was capable of suppressing tumor growth associated with damage to the tumor vessels and the death of cancer cells in humans.

Positioning systems play an important role in industrial and scientific applications, making their performance improvements and functional expansions crucial. Positioning systems generally consist of mechanisms, actuators, controllers, and sensors, with performances and functions depending on their integration. Accordingly, positioning technologies focus on these elements and their integration into the system. Actuators are fundamental and critical elements that characterize positioning systems. Electromagnetic actuators are the most widely used because of their high basic performance, and piezoelectric actuators are often used for fine movement. In addition, research on new actuators with unique characteristics is actively being pursued. In component integration, control technology plays a crucial role in effectively utilizing the characteristics of elements and addressing their drawbacks. With the recent advances in digital technology facilitating nonlinear representations and structural modifications, various control methods have been proposed and evaluated to benefit from these advances. In addition to proposing modeling methods, the effects of manufacturing processes on system performance have been evaluated. This special issue contains 18 papers covering the design and characteristics of mechanisms and actuators, control technology, system design, and modeling, along with three review papers on positioning technology and its applications. We would like to express our sincere gratitude to the authors for their excellent contributions to the special issue. We also thank the reviewers for their incisive efforts in editing this special issue. We hope that this special issue will help readers enhance their knowledge and understanding of positioning technology and its applications, thereby contributing to its progress.

Energy consumption in the manufacturing sector is becoming a very hot topic due to its significant ecological relevance, especially for energy intensive processes such as machining. Machining finds nowadays large application mainly due to its high performance, in terms of both surface finish and tolerances achievable; as an example this is the key technology in dies and molds production, largely used in the automotive and housewares sectors. Process optimization could be carried out using different strategies, as already proposed by many authors, such as by optimizing machining parameters or implementing alternative toolpath capable of reducing both machining time and energy consumption. Within this paper will be presented a novel approach that takes into account the product orientation within the working zone of the machine. Milling machines are usually non symmetric regarding the energy consumptions of the axes due to the different masses that have to be moved, hence product orientation could sensibly affect energy consumption in performing a toolpath. Optimizing product orientation has the advantage not to affect product quality and require no adjustment of machining parameters. An approach to model the machine power consumption and to optimize the workpiece orientation is presented together with the results of validation experiments.