Adjustable Frequency Research Articles

Microwave-Absorbing Foams with Adjustable Absorption Frequency and Structural Coloration.

Microwave-absorbing materials with regulatable absorption frequency and optical camouflage hold great significance in intelligent electronic devices and advanced stealth technology. Herein, we present an innovative microwave-absorbing foam that can dynamically tune microwave absorption frequencies via a simple mechanical compression while in parallel enabling optical camouflage over broad spectral ranges by adjusting the structural colors. The vivid colors spanning different color categories generated from thin-film interference can be precisely regulated by adjusting the thickness of the conformal TiO2 coatings on Ni/melamine foam. Enhanced interfacial and defect-induced polarizations resulting from the introduction of TiO2 coating synergistically contribute to the dielectric attenuation performance. Consequently, such a foam exhibits exceptional microwave absorption capabilities, and the absorption frequency can be dynamically tuned from the S band to the Ku band by manipulating its compression ratio. Additionally, simulation calculations validate the adjustable electromagnetic wave loss behavior, offering valuable insights for the development of next-generation intelligent electromagnetic devices across diverse fields.

A security‐enhanced equipment predictive maintenance solution for the ETO manufacturing

SummaryWith the rapid advancement of intelligent manufacturing, ensuring equipment safety has become a crucial prerequisite for enterprise production. In the engineer‐to‐order (ETO) production mode, characterized by diverse equipment types and frequent adjustments in production lines, equipment maintenance has become increasingly complex. Traditional maintenance plans are no longer adequate to meet the evolving demands of equipment maintenance. This paper proposes a security‐enhanced predictive maintenance scheme specifically designed for ETO‐type production equipment. The scheme utilizes industrial Internet of Things (IIoT) technology to monitor machines and equipment, constructs prediction models using machine learning methods, and reinforces the security of the prediction system through adoption of a decentralized architecture with blockchain distributed storage. In this experiment, six supervised learning models were compared, and it was found that the model based on the random forest algorithm achieved an outstanding accuracy rate of 98.88%. Furthermore, the average total response time for generating predictions within the system is 2.0 s, demonstrating a performance suitable for practical equipment maintenance applications.

Rotor resonance avoidance by continuous adjustment of support stiffness

This paper presents a method to reduce lateral vibration amplitudes in large rotating machines. The method is based on avoiding resonances by altering the natural frequencies of the rotor system at each rotating speed during operation. While many research papers have considered altering support stiffness during crossing critical speeds, continuous adjustment methods have received less attention. Continuous on-line adjustment of the natural frequencies of a rotor system is possible to a large range by adjusting the support stiffness of the bearing housings. The optimal foundation stiffness tuning policy can be defined utilizing a rotordynamic model or experimental measurements, effectively creating a resonance-free operating speed region, where vibrations are drastically reduced. It is shown through full-scale experimental laboratory tests, that the subcritical and supercritical response of the rotor system is significantly decreased during run-up and run-down with the optimal foundation stiffness tuning strategy. The developed method can be applied to reduce vibrations in any rotating machinery, where a variable foundation stiffness control can be installed. Moreover, this on-line foundation stiffness tuning strategy could also be applied in combination with resonance crossing methods involving stiffness manipulation.

The novel LESS (low-cost entrainment syringe system) O2 blender for use in modified bubble CPAP circuits: a clinical study of safety.

Bubble continuous positive airway pressure (bCPAP) is used in resource-limited settings for children with respiratory distress. Low-cost modifications of bCPAP use 100% oxygen and may cause morbidity from oxygen toxicity. We sought to test a novel constructible low-cost entrainment syringe system (LESS) oxygen blender with low-cost modified bCPAP in a relevant clinical setting. We conducted a clinical trial evaluating safety of the LESS O2 blender among hospitalized children under five years old in rural Cambodia evaluating the rate of clinical failure within one hour of initiation of the LESS O2 blender and monitoring for any other blender-related complications. Thirty-two patients were included. The primary outcome (clinical failure) occurred in one patient (3.1%, 95% CI = 0.1-16.2%). Clinical failure was defined as intubation, death, transfer to another hospital, or two of the following: oxygen saturation <85% after 30 min of treatment; new signs of respiratory distress; or partial pressure of carbon dioxide ≥60 mmHg and pH <7.2 on a capillary blood gas. Secondary outcomes included average generated FiO2's with blender use, which were 59% and 52% when a 5 mm entrainment was used vs. a 10 mm entrainment port with 5-7 cm H2O of CPAP and 1-7 L/min (LPM) of flow; and adverse events including loss of CPAP bubbling (64% of all adverse events), frequency of repair or adjustment (44%), replacement (25%), and median time of respiratory support (44 h). Overall the LESS O2 blender was safe for clinical use. The design could be modified for improved performance including less repair needs and improved nasal interface, which requires modification for the blender to function more consistently.

An enhanced wideband tracking method for characteristic modes

Abstract An enhanced wideband tracking method for characteristic modes (CMs) is investigated in this paper. The method consists of three stages, and its core tracking stage (CTS) is based on a classical eigenvector correlation-based algorithm. To decrease the tracking time and eliminate the crossing avoidance (CRA), we append a commonly used eigenvalue filter (EF) as the preprocessing stage and a novel postprocessing stage to the CTS. The proposed postprocessing stage can identify all CRA mode pairs by analyzing their trajectory and correlation characteristics. Subsequently, it can predict corresponding CRA frequencies and correct problematic qualities rapidly. Considering potential variations in eigenvector numbers at consecutive frequency samples caused by the EF, a new execution condition for the adaptive frequency adjustment in the CTS is introduced. Finally, CMs of a conductor plate and a fractal structure are investigated to demonstrate the performance of the proposed method, and the obtained results are discussed.

Tunable Ultralow-Frequency Bandgaps Based on Locally Resonant Plate with Quasi-Zero-Stiffness Resonators

In order to suppress the transverse vibration of a plate, a quasi-zero-stiffness (QZS) resonator with tunable ultralow frequency bandgaps was introduced and analyzed. The resonator was designed by introducing the quasi-zero-stiffness systems into mass-in-mass resonators. The plane wave expansion method was employed to derive the bandgap characteristics of the locally resonant (LR) plate with QZS resonators, and corresponding simulations were carried out by finite element method (FEM). The results show that an LR plate with a QZS resonator can provide two bandgaps, and the ranges of the bandgaps agree well with the vibration attenuation bands calculated by FEM. Owing to the introduction of the QZS system, the bandgaps can be easily transferred to a lower frequency or even an ultralow frequency. The damping of the QZS resonators can effectively broaden the vibration attenuation bands. In addition, the differentiated design of the bandgap frequencies can be realized to obtain broadband low-frequency transverse wave suppression performance. Finally, a mechanical structure design scheme was proposed in order to achieve flexible adjustment of the bandgap frequency, which significantly increases the engineering applicability of QZS resonators.

Automatic adjustment of oxygen concentration during high-flow nasal cannula treatment using a targeted SpO2 feedback system.

To test whether targeted SpO2 feedback (TSF), an automatic control system for fraction of inspired oxygen (FiO2), achieves more time in the optimal SpO2 range and/or reduces the frequency of manual adjustments to administered FiO2 compared with conventional manual titration in patients with hypoxia on high-flow nasal cannula (HFNC) therapy. Twenty-two patients were recruited from two hospitals. For each, two sessions of manual mode and two sessions of TSF were applied in a random order, each session lasting 2 h. The target SpO2 on TSF was 95%. Oxygen monitoring levels were classified into four SpO2 ranges: hypoxia (≤ 89%), borderline (90%-93%), optimal (94%-96%) and hyperoxia (≥ 97%). The two modes were compared based on the proportion of time spent in each SpO2 range and the number of manual FiO2 adjustments. The proportion of time in the optimal SpO2 range was 20.5% under manual titration mode and 65.4% under TSF (p < .01). The proportions of time in the hypoxia range were 1.1% and 0.4%, respectively (p = .31), in the borderline range 4.7% and 3.5%, respectively (p = .54), and in the hyperoxia range 73.7% and 30.7%, respectively (p < .01). There were statistical differences only in the optimal and hyperoxia SpO2 ranges. During the 8 h, the frequency of manual FiO2 adjustment was 0.7 times for the manual mode and 0.2 times for TSF, showing no statistically significant difference (p = 0.076). Compared with manual titration, TSF achieved greater time of the optimal SpO2 and less time of hyperoxia during HFNC. The frequency of manual adjustments on TSF tended to be less than on manual titration mode. Automatic closed-loop algorithm FiO2 monitoring systems can achieve better oxygen treatments than conventional monitoring and may reduce nurse workloads. In the era of pandemic respiratory diseases, this system can also facilitate contactless SpO2 monitoring during HFNC therapy.

A scoping review of Indigenous community-specific physical activity measures developed with and for Indigenous Peoples in Canada, Australia, and New Zealand.

Historical factors including colonization and ongoing socioeconomic inequities impact Indigenous Peoples' ability to mitigate chronic disease risks such as achieving recommended physical activity (PA) levels. Reliably assessing, reflecting, and promoting PA participation among Indigenous Peoples may be impacted by a lack of culturally appropriate assessment methods and meaningful engagement with Indigenous communities throughout the research process. The objectives of this scoping review were to examine: (1) How PA research with Indigenous Peoples used community-specific PA measures developed with and/or for Indigenous Peoples in Canada, Australia, and New Zealand; and (2) How the studies utilized community-based participatory research (CBPR) principles to engage communities. A systematic search was conducted in four electronic databases (Web of Science, Medline, University of Saskatchewan Indigenous Portal, and ProQuest Dissertations and Theses Global). Thirty-one (n=31) articles were identified and data extracted for narrative synthesis. Studies using community-specific PA measures have been increasing over time. Adapting questionnaires to traditional Indigenous activities such as cultural dances, ceremonies, and food-gathering activities were the most frequent adjustments undertaken to use community-specific measures. There are, however, gaps in research partnering with communities with only 6% of studies including all eight CBPR principles. Practical ways researchers can engage Indigenous communities and build capacity such as training and employing community members were highlighted. More needs to be done to facilitate community self-determination and develop long-term sustainable initiatives. Using culturally appropriate and relevant methodologies including partnering with Indigenous communities may help identification and implementation of culturally relevant and sustainable health-promoting initiatives.

Investigation of Terp-Pyr/p-Si diode using complex impedance spectroscopy depending on measurement temperatures and frequencies

A unique Al/Terp-Pyr/p-Si/Al diode structure that has not before been presented was introduced in this paper. Utilizing capacitance-conductance-frequency (C-G-f) characteristics in the frequency range of 20 Hz− 1.5 MHz for four temperatures of 300 K, 325 K, 350 K, and 375 K, admittance analysis was carried out to disclose the impedance and dielectric properties of the diode. The appearance of interface states at the Terp-Pyr/p-Si interface leads to an increase in capacitance values at low frequencies. Using complex impedance spectroscopy, the impedance characteristics of the Al/ Terp-Pyr/p-Si/Al Schottky diode were examined. The fabricated diode’s dielectric, modulus, and ac conductivity properties were investigated in the same frequency and temperature range. It has been revealed that while ϵ′\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\epsilon }^{{\\prime }}$$\\end{document} decreases up to high frequencies for all temperatures, it grows with temperature in the low-frequency zone. It becomes apparent that while the real component (M’) of modulus grows for all temperatures from low to high frequencies, it decreases at high frequencies as temperature rises. remarkably adjustable temperature, voltage, and frequency tuning of the dielectric constants (ϵ′,ϵ′′)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$({\\epsilon }^{{\\prime }},{{\\epsilon }^{{\\prime }}}^{{\\prime }})$$\\end{document} and dielectric loss tangent (tanδ). Additionally, the equivalent circuit of the Al/ Terp-Pyr/p-Si/Al Schottky diode and Cole-Cole diagrams were explored.

Ultrabroadband vernier cascaded microring filters based on dispersive Si3N4 waveguides

A viable candidate for use in silicon photonics and microwave photonics is the hybrid external cavity laser (ECL) chip, which offers a high extinction ratio, ultrabroadband mode-hopping-free tuning range, and small linewidth. It requires a photonic filter device with an ultrabroadband operating bandwidth and adjustable frequency selection capability. The Vernier cascaded microring filter is a prevailing filter technique that usually ignores chromatic dispersion and will result in noticeable frequency variations, particularly over a large frequency range. Based on dispersive Si3N4 waveguides, we develop ultrabroadband Vernier cascaded microring filters and examine the impact of chromatic dispersion. For the same waveguide geometry, the filter’s effective free spectral range (FSR) varies by more than 400 GHz with and without the dispersion. Furthermore, these Vernier filters, which are made of anomalous and normal dispersive waveguides respectively, exhibit mode hopping at the opposite frequency side. It leads to a sudden mode number leap and, consequently, a diversified dispersion condition for the convoluted filtering frequency. We show that this phenomenon is caused by the interplay between half of the FSR difference, and the accumulated frequency difference caused by the chromatic dispersion. Finally, the use of thermal-optical tuning enables accurate frequency tuning. Our findings offer a valuable resource for the engineering of hybrid ECLs at the chip scale.

Dual excitation self-balancing capacitance measurement method based on frequency adjustment

The double-ended excitation self-balancing bridge excitation method is a capacitance measurement method with rather a high measurement accuracy currently. However, the reference impedance of the electric bridge limits the traditional self-balancing excitation measurement method, making it difficult to achieve high accuracy and a wide range of capacitance sensor measurements. In the proposed paper, frequency adjustment method is introduced to enable impedance matching between the measured capacitance and the reference resistance. The measurement range is broadened as well as maintaining the accuracy of the capacitance measurement. The measurement circuit is composed of a reference resistor, a bridge in series with the measured capacitance and an operational amplifier follower circuit. First, we roughly measure the input impedance of the operational amplifier and the capacitive reactance of the capacitance under test using a two-step excitation method. Then, the best excitation frequency is calculated to match the reference resistor according to the capacitive reactance under test, and the input impedance of the operational amplifier is re-estimated with the best frequency. Finally, we complete the accurate measurement of the capacitive reactance under test through the use of dual excitation. The experimental results demonstrate the method’s high accuracy measurement within the range of 1.6 pF–16 nF, with the reference resistance set at 1 MΩ and the excitation frequency adjusted between 10 and 100 kHz. Additionally, dual excitation stability testing verifies relative standard deviations in the range of 0.01%–0.12%. Experiments on filter capsule sensing detection show that the proposed frequency adjustment measurement method can perform highly sensitive capacitive sensing measurements under the influence of parasitic effects.

Rancang Bangun Multilevel Inverter dengan Filter Pasif L-C-L dan Teknologi IoT Untuk Memantau Perubahan Kecepatan Motor Induksi Satu Fasa

Multilevel inverter is a type of inverter used to generate AC signals with adjustable frequency and better quality. L-C-L passive filter is used to eliminate harmonic distortion in the generated AC signals. Meanwhile, IoT technology is used to remotely monitor and control the speed of the motor through a mobile application. In this thesis, the design of a flying capacitor multilevel inverter is used as an induction motor speed controller with the resulting Total Harmonic Distortion (THD) can be reduced if you add a level to the inverter. Then, L-C-L passive filter is designed to eliminate harmonic distortion in the generated AC signals. Furthermore, the implementation of IoT technology is carried out using Blynk IoT platform. The test results show that the multilevel inverter with L-C-L passive filter successfully generates AC signals with better quality compare without L-C-L passife filter. In addition, IoT technology is successfully implemented and allows users to remotely monitor and control the speed of the motor through a mobile application. Thus, the use of multilevel inverter with L-C-L passive filter and IoT technology can effectively increase the efficiency and control of single-phase induction motor.&#x0D; Keywords: multilevel inverter, L-C-L passive filter, IoT, induction motor, total harmonic distortion.

An LLC resonant converter with wide output range fixed frequency PWM control for PEV charging applications

PurposeThis study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.Design/methodology/approachTo address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.FindingsAccording to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.Originality/valueThe feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.

Development of experimental device for inductive heating of magnetic nanoparticles

Inductive heating using magnetic nanoparticles is a critical process extensively investigated for cancer treatment. However, the high cost of commercially available equipment hinders its accessibility for many research groups. In response, this paper introduces a simple electronic circuit with low-cost components, making it easy to construct even for non-electronic experts. Operating within the 50–200 kHz range, the circuit employs a parallel inductor-capacitor configuration, providing a maximum induction magnetic field of 23.6 mT. Ltspice software simulations align well with oscilloscope measurements. Using commercial iron oxide nanoparticles (∼16 nm) in water suspensions (1–10 mg ml−1), the device exhibited a concentration-dependent reduction in specific absorption rate values, consistent with literature findings. Hyperthermia temperatures were achieved in a few minutes at 52.5 kHz and 23.6 mT in the highest concentration. At 81.9 kHz and 21.5 mT, a temperature of 93 °C was achieved after 22 min at 10 mg ml−1. Additionally, the device demonstrated stable and safe operation over a 100 min period, as validated by an ice-melting experiment. These results highlight the device’s efficacy for hyperthermia experiments in both biological and non-biological systems, particularly advantageous for larger nanoparticles in a blocked state. The proposed device holds significant potential for contributing to hyperthermia studies across diverse research groups. Future development will focus on frequency adjustment without reducing the alternating magnetic field amplitude and a thorough investigation of field homogeneity inside the coils.

A multichannel phase-locked waveform generator for a rotating electric field mass analyzer

We have developed a multichannel phase-locked sine waveform generator for a mass dispersive rotating electric field device, known as a rotating wall mass analyzer (RWMA). The waveform generator outputs eight sine waves phase shifted by 45°. The frequency of the waveforms is adjustable in the range of 0.1–100 kHz and the maximum amplitude is 100 Vp-p, which is greater than 20 Vp-p provided by commercial arbitrary waveform generators. Adjustment of either amplitude or frequency maintains phase alignment for all eight output channels to continually generate a uniform rotating electric field inside the RWMA. The RWMA is a high-throughput mass analyzer for preparative mass spectrometry that separates a multicomponent continuous ion beam in space and enables the deposition of ions of different m/z onto concentric ring shapes on surfaces. Here, we demonstrate that increasing the generator's amplitude from 20 Vp-p to 50 Vp-p resolves a continuous ion beam of ubiquitin charge states with a measured mass resolution (m/Δm) of R = 14. This resolution improves to R = 26 for a 100 Vp-p generator output. Furthermore, the designed waveform generator facilitates a single m/z calibration of the rotating electric field parameters to extract a m/z value from a measured radius. These parameters are shown to be valid for other m/z species, ion beam kinetic energies, and ionization polarity modes.

The Optimal Maintained Effective-site Concentration of Propofol under Target-controlled Infusion in Same-day Bidirectional Endoscopy

Background: The same-day bidirectional endoscopy (BDE) under anesthesia is commonly performed for its efficacy. Until now, the optimal regimen of sedation for same-day BDE is still inconclusive. Aim: The aim of this study is to investigate the relationship between the effect-site concentration at loss of consciousness (CeLOC) and maximal maintained Ce (CeM) in patients undergoing sole propofol sedation with the targeted-controlled infusion (TCI) pump and to explore the potential factors for extra fentanyl administration for same-day BDE to improve the quality of anesthesia. Methods: After excluding the patients with different anesthesiologists/endoscopists and esophagogastroduodenoscopy before colonoscopy, a total of 183 patients receiving BDE with the American Society of Anesthesiologists I to III were enrolled. Anesthesia with TCI of propofol ranged from 2.5 to 5.0 μg/mL was administrated and propofol was increased in steps of 0.5 μg/mL when inadequate or too deep sedation during the procedure. If the sedation level failed to meet satisfaction after two times of Ce increments or CeM achieve 5.0 μg/mL, bolus of fentanyl (25 μg) would be administered. The age, height, weight, gender, CeLOC, CeM, awake Ce, anesthesia time, examination time, frequency of TCI adjustments, total consumption of propofol or fentanyl, incidence of patient movements affecting the procedure, and use of ephedrine or atropine were retrieved from anesthetic charts and electronic medical record was recorded and the factors affecting the extra bolus of fentanyl or CeM were calculated. Results: One hundred and fifty-seven patients underwent procedures with only propofol sedation and 26 patients with additional fentanyl bolus 25 μg. There were three patients with hypotension, bradycardia, and transient hypoxemia in only propofol sedation, respectively. The incidence of patient movements affecting the procedure was 36.6% (67/183), 41 patients completed the procedure after increasing propofol Ce, and 26 patients required an extra bolus of fentanyl. After linear regression, the optimal formula was CeM = 1.9 – (0.006 × age) + 0.658 × CeLOC. After controlling for confounding covariates, only CeLOC was the most informative covariate for the demand for fentanyl. Finally, we simplified the formula as propofol CeM = CeLOC + 0.7 µg/mL to avoid patient movements affecting the procedure and adverse effects. Conclusion: We showed that the age and CeLOC were associated with CeM and only higher CeLOC (&gt;4.5 µg/mL) was the only contributing factor for the extra bolus of fentanyl in BDE. We also provided the simplified formula as propofol CeM = CeLOC + 0.7 µg/mL to avoid patient movements affecting the procedure and adverse effects.

P610 Ustekinumab demonstrates superior treatment persistence over anti-TNF in Crohn’s disease patients previously treated with vedolizumab

Abstract Background With the rise in biologic therapies to manage moderate to severe inflammatory bowel disease (IBD), determining the optimal treatment sequence has become crucial. This aids in the selection of the next biologic agent after prior exposure or unresponsiveness to a previous regimen. Vedolizumab (VDZ) is a gut-specific α4β7-integrin inhibitor recognized for its efficacy in treating moderate to severe IBD. Yet, only a few studies have assessed the comparative effectiveness of alternative biologics, such as ustekinumab (UST) and antitumor necrosis factor agents (anti-TNF), following VDZ exposure. Methods In our retrospective study conducted at Chang Gung Memorial Hospital at Linkou, a leading 3700-bed medical facility in Taiwan, we examined 110 IBD patients who underwent treatment with UST or anti-TNF agents (including adalimumab and infliximab) from May 2019 to September 2023. UST's standard maintenance dosing in Taiwan is every 12 weeks. We utilized Kaplan-Meier analysis and Cox proportional hazards models to evaluate the 52-week treatment retention of UST versus anti-TNF. Results Of the 110 participants, 40 were diagnosed with ulcerative colitis (UC), and 70 with Crohn’s disease. The demographics between the anti-TNF and UST groups regarding age, gender, and body mass index were comparable. The primary reason for vedolizumab discontinuation in both groups was secondary non-response (Table 1). UST exhibited a notably higher 52-week retention in overall IBD (HR: 5.36, 95% CI: 1.84-15.62, P = 0.002, Figure 1a) and in Crohn’s disease patients (HR: 10.75, 95% CI: 1.34-86, P = 0.025, Figure 1b) compared to anti-TNF. While UST also showed superior persistence at 52 weeks in UC patients, the difference was not statistically significant (HR: 2.25, 95% CI: 0.63-8, P = 0.211, Figure 1c). At the 52-week mark, 73.5% of the anti-TNF group and 81% of the UST group were not on steroids. Secondary non-response was the predominant cause for discontinuation of the current biologic. Notably, UST required more frequent dose adjustments than anti-TNF. The safety profile of both treatments was comparable. Conclusion UST showed superior treatment persistence, compared to anti-TNF in Crohn's disease patients who had previously been exposed to vedolizumab. However, UST required more frequent dosing adjustments compared to anti-TNF.

P1025 Analysis of the Clinical Characteristics of Elderly-onset Crohn's Disease

Abstract Background The prevalence of Crohn's disease in the elderly is increasing today. The purpose of this study was to analyze the clinical characteristics of elderly-onset patients with Crohn's disease and compare with non-elderly-onset adult patients. Methods All Crohn's disease patients with onset aged 60 years and older at our Inflammatory Bowel Disease Center in recently ten years were retrospectively included. The elderly were compared with adult patients aged 18-59 at the time of onset, who were matched according to diagnosis time and gender by a 1:3 ratio of propensity score matching. After matching, the clinical data were recorded and analyzed to compared between the two groups of patients. Results A total of 68 patients were included, including 17 patients in the elderly-onset group and 51 patients in the non-elderly-onset adult group. The mean age of diagnosis in the two groups was 30.3±8.7 years and 63.9±4.24 years, and the mean course of disease was 30.3 months and 63.9 months, respectively. According to the Montreal classification, most elderly patients presented with L3 (70.6%) and B1 (58.8%), no cases involving the upper digestive tract or multiple lesion sites, showed mild disease activity (76.5%). The elderly group had fewer intestinal complications and parenteral manifestations. The medication types of elderly are 5-aminosalicylates (52.9%), traditional immunosuppressive agents (45.6%) and enteral nutrition preparations (29.4%) being the more frequent types of medications used, and glucocorticoids and biologics being used less frequently. Exposure to two or more IBD medications was 31.4% and 52.9% in the non-elderly onset adult group versus the elderly onset group, respectively (p=0.110). During follow-up, symptoms such as diarrhea (11.8 vs 5.9%), abdominal pain (35.3% vs 17.6%) and weight loss (11.8% vs 3.9%) were more common in the elderly-onset group. Elderly patients had more hospitalizations on average (0.22 vs. 1.12). 40.7% of elderly patients underwent CD-related surgery during the duration of their disease, with 50.0% of patients undergoing reoperation. Conclusion Compared with non-elderly-onset adult patients, elderly-onset patients with Crohn's disease are more common in women, and the lesion mainly in the ileum and ilecolon; the disease behavior is mainly B1; nearly half of the patients have intestinal complications The elderly have atypical clinical manifestations, basically haven’t family history of IBD, take longer to diagnose, have more underlying diseases, more hospitalizations on average, and are more likely to have complications. They are more likely to receive conservative treatment, but with more frequent medication adjustments and a higher likelihood of undergoing CD-related surgery.

The importance of vocal self-regulation

The human voice is extremely flexible and adjustments of quality, frequency, and intensity serve to signal various moods, emotions, and intentions. These modifications occur automatically in daily life, but can also be implemented in a developed, controlled, and consciously applied way, in spoken and sung artistic expression. The vocal output depends on a series of anatomical, physiological, and neurological factors, however, there is a crucial participation of the emotional component that impacts the vocal output.

Development of an energy-saving PWM driving method for precision pesticide application using adjustable frequency and characterization of spray

Precise pesticide application is mainly to control the solenoid valve by pulse width modulation (PWM). However, as the number of solenoid valves increases, power consumption and heat generation become significant challenges that impact values the efficiency and lifetime. In this study, an automated pressure monitoring system was constructed and an energy-saving PWM driving method was developed that uses different frequency drive signals during different stages of the solenoid valve operation. The parameters such as power consumption, coil surface temperature rise, opening and closing delays, rise and fall times, activation time, and spray flow characteristics were tested and evaluated. The results showed that this method can significantly reduce the holding current of the solenoid valves, resulting in energy savings of up to 92% and effectively reducing the surface temperature rise. Furthermore, the pattern between flowrate and opening/closing delays was established, with an RMSE of 1.96% in flowrate prediction based on activation time. The developed energy-saving driving method enhances the application potential while the established flowrate model provides valuable insights for precise pesticide application based on PWM technology.