Search Results (222)

Background/Objectives: Depression is a serious mental illness worldwide, with a continuously increasing prevalence. As evidence supporting forest therapy as a non-pharmacological intervention has accumulated, the need for collaboration between the medical and forest therapy sectors has emerged; however, practical tools applicable in real-world clinical settings remain limited. This study aimed to derive components of a diagnostic assessment sheet to support clinicians in developing personalized forest therapy programs for patients with depression. Methods: Program-related literature and case materials from diverse disciplines were systematically analyzed to identify transferable program development elements and therapeutic activities. Based on these findings, a two-round Delphi survey was conducted with 17 experts in forest therapy and medicine. Results: Through the Delphi process, 26 therapeutic activities were identified and classified into six final activity types. Assessment items were developed to support clinicians in selecting appropriate activity types, and nine key precaution items were identified to enhance safety and appropriateness during program design and implementation. Conclusions: This study provides a structured framework to guide clinicians and forest therapy instructors in composing individualized forest therapy programs for patients with depression, supporting practical medical–forest therapy integration. Future research should validate the diagnostic assessment sheet through empirical field testing. Full article

This work presents a direct conversion transmitter (DCT) for 5G new radio (NR) that eliminates the RF driver by directly feeding a single stage cascode PA through a baseband buffer amplifier and passive up-conversion mixer. The baseband interface uses Class-AB buffers to hold the output capacitor voltage, enabling accurate sampling at the PA input. A mixer switch is selected for minimal on-resistance variation over the required baseband swing. The PA is designed with separate I and Q voltage inputs and a current summing structure. The PA operates at 2.5 V; other blocks use 1.2 V. Post-layout two-tone simulations at 5 GHz indicate 21 dBm output saturation power and −36.1 dBc of IMD3 at 9 dB PBO power while removing the driver to inter stage matching network of a two-stage design. The results validate a compact, driverless architecture for integrated transmitters. Full article

Polymeric materials have become important components in prefilled syringes, drug delivery systems, and advanced medical devices. Background/Objectives: Nitrogen dioxide gas is used for the terminal sterilization of drug delivery systems. For the implementation of sterilization methods, compatibility with materials must be demonstrated such that the materials maintain product requirements and specifications after sterilization and at the time of use (i.e., product shelf life). Methods: Commonly used polymers were selected based on their chemical structures to provide insight into the nature of reactions that occur at the temperature and NO₂ concentration levels used in the sterilization process. After exposure to the NO₂ process, materials were evaluated for chemical, mechanical, and biocompatibility properties. Results: In this paper, we demonstrated the compatibility of polymers comprising carbonyl, unsaturated ester, and ketone groups which have been used in medical devices sterilized with NO₂. No significant chemical or physical changes were observed upon the treatment of Amorphous Polyester, Polysulfone (PSU), Polycarbonate (PC), PolyEtherEtherKetone (PEEK), PolyArylEtherKetone (PAEK), and Polypropylene (PP) with NO₂ at a sterilization temperature of 20 °C. At this relatively low sterilization temperature, the reactions of NO₂ with the polymer do not typically occur because the activation energies of these reactions require much higher temperatures. Conclusions: Not all materials will be compatible with NO₂ sterilization, and even with the established data, many devices will need to have their polymers evaluated for compatibility before moving to NO₂ sterilization. These results will provide guidance to device designers selecting materials for new drug delivery devices and to regulators that review the safety and efficacy of these devices. Full article

Additive manufacturing (AM) of polyetheretherketone (PEEK) offers a promising route for producing lightweight, biocompatible, and patient-specific medical implants with complex geometries. This study investigates and optimizes fused deposition modeling (FDM) parameters for fabricating small-scale PEEK medical components with improved dimensional accuracy and surface quality. PEEK’s high processing temperature and thermal contraction make precision printing of fine features challenging. A Taguchi design of experiments (L9 orthogonal array) was employed to assess the effects of nozzle temperature, layer height, printing speed, and extrusion width on dimensional deviation and surface roughness using 5 × 5 × 5 mm cube specimens. Dimensional accuracy was quantified along the horizontal and vertical axes, and surface roughness was measured using a stylus profilometer. Statistical analysis showed layer height was the most significant factor affecting horizontal accuracy (p = 0.0225), while printing speed most strongly influenced vertical deviation. The optimal parameters, 450 °C nozzle temperature, 0.06 mm layer height, 7.5 mm/s printing speed, and 0.4 mm extrusion width, achieved mean deviations of 0.013 mm (horizontal) and 0.049 mm (vertical) with a surface roughness of 4.01 µm. Validation using a benchmark model and micro-computed tomography confirmed improved reproduction of small features under these conditions. The results demonstrate that precise control of FDM parameters enables accurate fabrication of sub-millimeter PEEK structures suitable for medical device applications. Full article

Background: Smoking cessation has been associated with reduced lung cancer mortality. This study aimed to synthesize current evidence on the impact of quitting smoking at or around the time of diagnosis of lung cancer on survival, considering factors such as histological subtype, cancer stage, and cessation intervention. Methods: A systematic search was conducted in the Ovid-MEDLINE, Ovid-EMBASE, Cochrane Central Register of Controlled Trials, and KoreaMed databases up to September 2024. Randomized controlled trials and cohort studies enrolling adult current smokers with pathologically confirmed lung cancer and comparing smoking cessation at or around diagnosis with continued smoking, were included. The primary outcome was overall survival (minimum follow-up of 3 months). The included studies were critically appraised using the revised Risk of Bias for Nonrandomized Studies (RoBANS 2) tool and meta-analyzed. Results: A total of 25 cohort studies comprising 17,584 patients were reviewed. Quitting smoking at diagnosis was associated with a 26% reduction in mortality risk (adjusted HR [aHR] 0.74, 95% CI 0.68–0.81). In subgroup analyses, quitting smoking was associated with improved survival in both non-small cell lung cancer (aHR 0.73, 95% CI 0.64–0.83) and small cell lung cancer (aHR 0.61, 95% CI 0.51–0.72), with a more pronounced benefit among patients with early-stage disease (stage I–III or limited stage; aHR 0.64, 95% CI 0.56–0.74). Furthermore, active smoking cessation interventions were significantly associated with improved survival (aHR 0.55, 95% CI 0.35–0.88). Conclusions: The findings underscore the importance of encouraging smoking cessation at the time of lung cancer diagnosis as an integral part of patient management to improve survival outcomes. Full article

The crystallization behavior of poly(aryletherketone) (PAEK) determines its applicable molding process and profoundly affects its mechanical properties. However, research on the crystallization behavior of new PAEKs and their impact on performance is still insufficient. In this work, the isothermal crystallization behavior of a novel PAEK was studied and compared with that of standard poly(etheretherketone) (PEEK). The influence of molding temperatures on the mechanical properties of thermoplastics was revealed by controlling the crystallization temperatures and analyzing the crystallization behavior. The results indicate that due to the disruption of the molecular structure regularity of PAEK, its melting temperature for primary crystallization is generally about 30 °C lower than that of PEEK, which is beneficial for its molding at lower temperatures. At the same undercooling level, the crystallization rate of PAEK is lower than that of PEEK, making it easier to control the crystallinity of PAEK through process parameters. The crystallinity of the thermoplastics increases with the increase in soaking time, thereby improving their tensile strength and modulus. The maximum crystallinity of PAEK is approximately 20.5%, which is lower than PEEK’s value of 31.8%. Therefore, under the same undercooling condition, the tensile strength and modulus of PEEK increase by up to 29.5% and 17.1%, respectively, compared to PAEK. Therefore, by precisely controlling the molding process parameters of PAEK, their crystallization behavior can be managed, enabling the achievement of various properties as needed. Full article

Background/Objectives: Pediatric foreign body (FB) ingestion is a common clinical problem that frequently necessitates time-sensitive decisions regarding esophagogastroduodenoscopy (EGDS). Although established high-risk criteria guide the indication for EGDS, coins—despite their high prevalence—are not uniformly classified as high-risk FBs. In this study, we aimed to delineate epidemiology and endoscopic outcomes and to identify predictors of EGDS. Methods: We retrospectively reviewed cases of children younger than 15 years presenting to an urban emergency department (ED) with suspected or confirmed FB ingestion between 2014 and 2020. After applying exclusion criteria, 757 patients remained for analysis. Data abstracted included demographic characteristics, presenting symptoms, type and location of FB, ED length of stay (EDLOS), and whether EGDS was performed along with its outcomes. Multivariable logistic regression was used to identify predictors of EGDS, including age group, sex, symptom presence, established high-risk criteria, and type of FB (coin, button battery, magnet). Results: Among 757 children (median age 17.0 months; 54.0% male), 55.2% were asymptomatic. EGDS was performed in 47 of the 757 children (6.2%), with a success rate of 74.5% (35/47). Among EGDS cases, the most common foreign bodies were coins (29.8%), button batteries (27.7%), and magnets (17.0%). In multivariable models, established high-risk criteria were the dominant determinant of EGDS (adjusted OR ≈ 179.4; 95% CI, 29.9–1075.8; p < 0.001). Compared with button batteries, coin ingestion was independently associated with EGDS (adjusted OR ≈ 7.26; 95% CI, 1.07–49.31; p = 0.042). Conclusions: Established high-risk criteria were the primary determinant of EGDS, and coin ingestion showed a possible independent association with EGDS; these findings suggest that coin ingestion may warrant consideration as a potential high-risk factor when determining whether endoscopy is indicated. Full article

Traditional encryption prioritises confidentiality but complicates search operations, requiring decryption before searches can be conducted. The public key encryption with keyword search (PEKS) scheme addresses this limitation by enabling authorised users to search for specific keywords within encrypted data without compromising the underlying encryption. This facilitates efficient and secure data retrieval without the need to decrypt the entire dataset. However, PEKS is susceptible to the keyword guessing attack (KGA), exploiting the deterministic nature of the PEKS trapdoor so that the adversary can correctly guess the keyword encrypted in a trapdoor. To enhance PEKS security to counter a KGA, various schemes have been proposed. A notable one is public key authenticated encryption with keyword search (PAEKS). PAEKS combines authentication and encryption with keyword-based search functionalities, ensuring data source authentication, encrypted information security, and keyword-based searches. However, many existing PAEKS schemes rely on computationally exhaustive bilinear pairing. In this paper, we propose a PAEKS scheme based on k-resilient identity-based encryption without bilinear pairing. By using the provable security approach, we show that our proposed PAEKS scheme satisfies both ciphertext privacy and trapdoor privacy. We present a comparison of the computation cost of our proposed PAEKS scheme with the existing PAEKS schemes and highlight its efficiency, particularly in the $\mathsf{Test}$ algorithm, where it achieves the fastest execution time. By performing experiments using the real-world Enron Email dataset, we show that the proposed scheme is efficient. Full article

This paper presents the first hybrid supply modulator (HSM) designed for envelope tracking power amplifiers (ET-PAs) in base station applications. The focus is on a rail-to-rail Class-AB linear amplifier (LA) optimized for high-voltage and wide-bandwidth operation. The LA is designed using 130 nm BCD technology, utilizing Laterally Diffused Metal-Oxide Semiconductor (LDMOS) transistors for high-voltage operation and incorporating shielding MOSFETs to protect the low-voltage devices. The circuit utilizes dual power supply domains (5 V and 30 V) to improve power efficiency. The proposed LA achieves a bandwidth of 100 MHz and a slew rate of +1003/−852 V/$\mathsf{\mu }\mathrm{s}$, with a quiescent power consumption of 0.89 W. Transient simulations using a 50 MHz bandwidth 5G NR envelope input demonstrate that the proposed HSM achieves a power efficiency of 83%. Consequently, the proposed HSM supports high-output (100 W) wideband 5G NR transmission with enhanced efficiency. Full article

Thermoplastic in situ Automated Fiber Placement (AFP) is an additive manufacturing method currently investigated for its suitability for the production of aerospace-grade composite structures. A considerable expense in this process is the manufacturing and preparation of a mold in which a composite part can be manufactured. One approach to lowering these costs is the use of a 3D-printable thermoplastic mold. However, AFP lay-up on a 3D-printed mold differs from the usage of a traditional metallic mold in various aspects. Most notable is a reduced stiffness of the mold, a lower thermal conductivity of the mold, and the need for varied process parameters of the AFP process. This study focuses on the investigation of the difference in mechanical and morphological characteristics of laminates produced on metallic and polymeric molds. To this end, the tensile strength and the interlaminar shear strength of laminates manufactured on each substrate were measured and compared. Additionally, morphological analysis using scanning electron microscopy and differential scanning calorimetry was performed to compare the crystallinity in laminates. No statistically significant difference in mechanical or morphological properties was found. Thus, thermoplastics were shown to be a suitable material for non-heated molds to manufacture in situ AFP composites. Full article

With the advent of the Internet of Things (IoT), large volumes of sensitive data are produced from IoT devices, driving the adoption of Machine Learning as a Service (MLaaS) to overcome their limited computational resources. However, as privacy concerns in MLaaS grow, the demand for Privacy-Preserving Machine Learning (PPML) has increased. Fully Homomorphic Encryption (FHE) offers a promising solution by enabling computations on encrypted data without exposing the raw data. However, FHE-based neural network inference suffers from substantial overhead due to expensive primitive operations, such as ciphertext rotation and bootstrapping. While previous research has primarily focused on optimizing the efficiency of these computations, our work takes a different approach by concentrating on the rotation keyset design, a pre-generated data structure prepared before execution. We systematically explore three key design spaces (KDS) that influence rotation keyset design and propose an optimized keyset that reduces both computational overhead and memory consumption. To demonstrate the effectiveness of our new KDS design, we present two case studies that achieve up to 11.29× memory reduction and 1.67–2.55× speedup, highlighting the benefits of our optimized keyset. Full article

Polyaryletherketone (PAEK) polymers inherently exhibit low surface activity, leading to poor adhesive bonding performance when using epoxy-based adhesives. In this study, low-temperature plasma surface modification was conducted on carbon fiber-reinforced polyetherketone ketone (CF/PEKK) composites to investigate the influence of plasma treatment parameters on their lap shear strength. Surface characterization was systematically performed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle analysis to evaluate morphological, chemical, and wettability changes induced via plasma treatment. The results demonstrated a significant enhancement in lap shear strength after plasma treatment. Optimal bonding performance was achieved at a treatment speed of 10 mm/s and a nozzle-to-substrate distance of 5 mm, yielding a maximum shear strength of 28.28 MPa, a 238% improvement compared to the untreated control. Notably, the failure mode transitioned from interfacial fracture in the untreated sample to a mixed-mode failure dominated by cohesive failure of the adhesive and substrate. Plasma treatment substantially reduced the contact angle of CF/PEKK, indicating improved surface wettability. SEM micrographs revealed an increased micro-porous texture on the treated surface, which enhanced mechanical interlocking between the composite and adhesive. XPS analysis confirmed compositional alterations, specifically elevated oxygen-containing functional groups on the plasma-treated surface. These modifications facilitated stronger chemical bonding between CF/PEKK and the epoxy resin, thereby validating the efficacy of plasma treatment in optimizing surface chemical activity and adhesion performance. Full article

The aim of this study was to evaluate the influence of filler type, filler content, and filler silanization on the flexural strength (FX), elastic modulus (E_m), shore D hardness (SDH), and two-body wear (2BW) of polyaryletherketone (PAEK) compounds. Specimens (40 wt% PEEK, 40 wt% PEK) with different filler types: 20 wt%: fumed silica (FS), calcium silicate (CS), feldspar (FP), magnesium silicate hydrate (MSH), no filler (NF); different filler content: 20, 25 or 30 wt% CS; different filler silanization: 20 wt% CS silanized with alkylsilane/aminosilane, FP silanized with methylsilane/ vinylsilane, no silanization; and PEEK₂₀ (BioHPP) or PEEK₂₅ (BioHPP plus) controls were fabricated and tested for FX, E_m, and SDH. Two-body wear (4 × 100,000 cycles, 50 N, 2.5 Hz) with composite resin antagonists was measured with PAEK_i (35 wt% PEEK, 35 wt% PEK, 30 wt% CS), PAEK_ii (70 wt% PEEK, 30 wt% CS), PAEK_iii (70 wt% PEEK, 25 wt% CS, 5 wt% FP), and PEEK₂₀ controls. Data were analyzed with Kolmogorov–Smirnov-, Kruskal–Wallis-H-, post hoc Scheffé test, pairwise comparisons, Bonferroni correction, one-way ANOVA, and Spearman rho (α = 0.05). An abrasion area analysis was performed. Adding filler increased FX, E_m, and SDH, with CS and MSH showing the highest values for FX and E_m. Adding 30 wt% CS increased FX, E_m, and SDH compared with 20 wt%. Silanization with methylsilane increased FX, E_m, and SDH. Silanization with aminosilane increased FX and SDH. PEEK₂₀ showed the lowest 2BW compared with all EPCs. No material losses were detected on the antagonists. PAEK compounds with 25 to 30 wt% CS increased FX and E_m compared to lower contents, no filler, or PEEK₂₀. Higher values of FX and E_m did not lead to lower 2BW. Full article

Objectives: This study aimed to compare the impact of robotic (RO) versus laparoscopic single-site ovarian cystectomy (LO) on ovarian reserve, as measured by changes in anti-Müllerian hormone (AMH) levels. Methods: A total of 43 women undergoing LO and 40 women undergoing RO for mature cystic teratoma were included. The baseline characteristics and surgical outcomes were scrutinized. AMH levels were evaluated preoperatively and at 3 months after surgery. Results: BMI (body mass index) was higher in the LO group (23.1 ± 3.6 cm vs. 21.7 ± 2.1 kg/m², p = 0.03) than in the RO group. Otherwise, there were no statistically significant differences in patient characteristics. The LO group showed a shorter operative time (70.0 ± 24.0 vs. 86.5 ± 26.7 min, p = 0.002) than the RO group., However, multiple linear regression analysis revealed that BMI was independently associated with increased operative time (p = 0.001), while the surgical method was not a significant predictor (p = 0.725). There were no significant differences in the rate of decline in AMH level between the LO and RO groups (13.3 ± 21.2 vs. 4.64 ± 34.1%, p = 0.167). There were intergroup differences in the hemostasis method: in the LO group, bipolar coagulation was performed for 27 (62.8%) patients, and sutures were performed for 16 (37.2%) patients; in the RO group, bipolar coagulation was performed for 5 (12.5%) patients, and sutures were performed for 33 (82.5%) patients, while in the case of 2 (5.0%) patients, hemostasis was not performed (p < 0.001). However, note that in our logistic regression analysis, the hemostasis method was excluded as an independent factor affecting AMH. Conclusions: There appear to be no significant advantages of RO over LO in terms of ovarian reserve preservation. Full article