Operating Characteristics Research Articles

Nomogram based on virtual hyperemic pullback pressure gradients for predicting the suboptimal post-PCI QFR outcome after stent implantation.

Growing evidence shows an association between higher post-PCI quantitative flow ratios (QFR) and improved clinical prognosis, however, no models are available to predict suboptimal QFRs (< 0.91) after angiographically successful PCI. This study aims to establish a prediction nomogram for this domain. This study included 450 vessels derived from 421 consecutive patients enrolled in the PIONEER IV trial, which were randomly assigned in a 1:1 ratio to a training (N = 225) and internal validation (N = 225) set, with external validation performed in 97 vessels from 95 consecutive patients enrolled in the ASET Japan trial. LASSO regression was used for optimal feature selection, and multivariate logistic regression was subsequently utilized to construct the nomogram. The performance of the nomograms was assessed and validated by area under the receiver operating characteristics curve (AUC), calibration curves, decision curve analysis, and clinical impact curves. The nomogram was constructed incorporating a novel metric, quantitative flow ratio derived pullback pressure gradient (QFR-PPG), alongside four conventional parameters: left anterior descending artery disease, pre-procedural QFR, reference vessel diameter, and percent diameter stenosis. AUCs of the nomogram were 0.866 (95%CI:0.818-0.914), 0.784 (95% CI:0.722-0.847), and 0.781 (95% CI:0.682-0.879) in the training, internal validation and external validation sets, respectively. Bias-corrected curves revealed a strong consistency between actual observations and prediction. The risk of a suboptimal post-PCI QFR in patients after angiographically successful PCI can be effectively predicted using a nomogram incorporating five variables available pre-PCI, with its performance and clinical predictive value confirming its utility in helping clinicians with decision-making and planning revascularization. Registered on clinicaltrial.gov (NCT04923191 and NCT05117866).

Comparison of intraepidermal nerve fiber density and confocal corneal microscopy for neuropathy.

Compare the diagnostic characteristics of intraepidermal nerve fiber density (IENFD) and confocal corneal microscopy (CCM) for distal symmetric polyneuropathy (DSP) and small fiber neuropathy (SFN). Participants with obesity were recruited from bariatric surgery clinics and testing was performed prior to surgery. DSP and SFN were determined using the Toronto consensus definitions of probable neuropathy. IENFD was assessed from 3 mm punch biopsies of the distal leg and proximal thigh. CCM was performed on both eyes with manual and automated counting. The Michigan Neuropathy Screening Instrument questionnaire (MNSIq) was also completed. Diagnostic capability was determined using areas under the receiver operating characteristics curve (AUC) from logistic regression. We enrolled 140 participants (mean [standard deviation [SD]] age: 50.3 years [7.1], 77.1% female, BMI: 44.4 kg/m2 [6.7]). In this population, 22.9% had DSP and 14.3% had SFN. Distal leg IENFD had the largest AUC (95% confidence interval) for DSP (0.78, 0.68-0.89) and SFN (0.85, 0.75-0.96). Proximal thigh IENFD (DSP: AUC: 0.59, 0.48-0.69, SFN: AUC: 0.59, 0.46-0.73) and CCM metrics (DSP: AUC range: 0.55-0.60, SFN: AUC range: 0.45-0.62) had poorer diagnostic capability than distal leg IENFD for DSP/SFN (P < 0.05). MNSIq had similar diagnostic capability to distal leg IENFD for both DSP/SFN (DSP: AUC: 0.76, 0.68-0.85, SFN: AUC: 0.81, 0.73-0.88). More participants (52%) preferred skin biopsies to CCM. Distal leg IENFD was the best quantitative measure of DSP/SFN. CCM had poor diagnostic characteristics and fewer patients preferred this test to IENFD. The MNSIq had similar diagnostic characteristics to distal leg IENFD, indicating its value as a diagnostic tool in the clinical setting. clinicaltrials.gov: NCT03617185.

Multi-omics approach to reveal follicular metabolic changes and their effects on oocyte competence in PCOS patients

BackgroundPolycystic ovary syndrome (PCOS) is a common heterogeneous disorder linked with endocrine and metabolic disturbances. The underlying mechanism of PCOS, especially its effect on oocyte competence, remains unclear. The study aimed to identify abnormal follicular metabolic changes using a multi-omics approach in follicular fluid from PCOS patients and to determine their effects on oocyte competence.MethodsA total of 36 women with PCOS and 35 women without PCOS who underwent in vitro fertilization and embryo transfer were included in the study. Cumulus cells and follicular fluid samples were collected. Follicular fluid samples underwent metabolomic analysis, while cumulus cell clusters from the same patients were assessed using transcriptomic analysis. Clinical information of patients and assisted reproductive technology (ART) results were recorded. Transcriptomics and metabolomics were integrated to identify disrupted pathways, and receiver operation characteristics (ROC) analysis was conducted to identify potential diagnostic biomarkers for PCOS. Pearson correlation analysis was conducted to assess the relationship between metabolites in follicular fluid and oocyte competence (fertilization and early embryo development potential).ResultsThrough multi-omics analysis, we identified aberrantly expressed pathways at both transcriptional and metabolic levels, such as the citrate cycle (TCA cycle), oxidative phosphorylation, the cAMP signaling pathway, the mTOR signaling pathway, and steroid hormone biosynthesis. Ten candidate metabolites were identified based on metabolic profiling data from these altered pathways. Phytic acid, succinic acid, 2’-deoxyinosine triphosphate, and 4-trimethylammoniobutanoic acid in the follicular fluid exhibited high specificity and sensitivity in distinguishing PCOS. Among these metabolites, L-arginine showed a negative correlation with the 2PN fertilization rate and cleavage rate, while estrone sulfate showed a negative correlation with the high-quality embryo rate in the in-vitro fertilization (IVF) cycle.ConclusionsWe have conducted a preliminary study of a novel metabolic signature in women with PCOS using a multi-omics approach. The alterations in key metabolic pathways may enhance our understanding of the pathogenesis of PCOS.

A systematic review of unique methods for measuring discount rates

AbstractDiscount rates play a pivotal role in various fields, capturing the trade-off between present and future, influencing predictions of unhealthy behaviors. Despite substantial variations in discount rates across studies, methods, and individuals, our goal was to systematically overview diverse methods for measuring discount rates. We conducted a comprehensive literature review across multiple databases, targeting English studies introducing and utilizing discounting measurement methods in human subjects. Two authors screened titles and abstracts, with full text review split between them. Extracted data encompassed bibliographic details, theoretical aspects (e.g., discount function), and operational features (e.g., elicitation procedure). After deduplication, 4976, 218, and 83 records underwent title and abstract screening, full text screening, and inclusion, respectively. A total of 86 unique methods were identified. Predominantly, methods were devised for money (75%) and health (22%) discounting. Network analysis on citations indicated limited cross-disciplinary overlap. Only about one fourth, one third, and one third of methods possessed theoretically desirable traits: i) allowance for negative discount rates, ii) application of multiple discount functions, and iii) correction for non-linear utility of outcomes. Diverse discounting measurement methods exist, showcasing varied theoretical and operational characteristics. These differences may stem from the isolation of development in fields like psychology, experimental economics, and health economics. Our systematic review aids readers in choosing methods aligned with their priorities when measuring discount rates.

Myocardial strain analysis by feature tracking cardiac magnetic resonance to identify subclinical cardiac dysfunction in patients with MINOCA

BackgroundTo investigate whether feature tracking cardiac magnetic resonance (FT-CMR) can identify subclinical myocardial dysfunction in patients with myocardial infarction with non-obstructed coronary arteries (MINOCA).MethodsClinical data and CMR images of MINOCA patients (N = 46) and control individuals (N = 12) were compared. The infarct and edema volume to total myocardium, peak global longitudinal strain (GLS), global longitudinal strain rate (GLSR), peak global circumferential strain (GCS), global circumferential strain rate, peak global radial strain, and global radial strain rate were measured. Diagnostic performances of strain parameters for MINOCA were evaluated by logistic regression and receiver operating characteristics analysis.ResultsExcept smoking history, the two groups showed no significant differences in cardiovascular risk factors and traditional heart function. GLS (-14.67 ± 1.96% vs. -19.19 ± 2.05%), GLSR (-0.94 ± 0.16 S− 1 vs. -1.23 ± 0.14 S− 1) and GCS (-17.59 ± 1.81% vs. -19.22 ± 1.76%) were impaired in MINOCA patients compared with the control group. MINOCA patients with normal routine CMR showed abnormalities in GLS (-16.23 ± 1.16%) and GLSR (-1.04 ± 0.16 S− 1). GLS and GLSR were predictive for MINOCA diagnosis (P = 0.002 vs. P = 0.033). GLS correlated strongly with myocardial infarction and edema. The optimal diagnostic threshold for GLS was <-16.9% for MINOCA diagnosis (sensitivity 87.1%, specificity 92.9%); the area under the receiver operating characteristic curve was 0.968.ConclusionsMyocardial strain by FT-CMR may effectively detect early myocardial impairment with MINOCA, especially in patients with normal routine MRI.

Design and performance of a dual-band plasmonic perfect absorber for infrared refractive index sensing

In this study, we introduce what we believe is an innovative design for a plasmonic perfect absorber (PPA) that is based on half-cut disk resonator metamaterials. This design exhibits remarkable stability and versatility, demonstrating effective functionality across a wide range of incident angles for both transverse electric (TE) and transverse magnetic (TM) polarization. The distinct operational characteristics of the PPA are highlighted by the presence of two corresponding absorption peaks at wavelengths of 870 and 1599 nm, where it achieves outstanding maximum absorption rates of 98.99% and 97.5%, respectively. The design’s ultra-narrow resonance peaks are indicative of its high-quality factors, which are vital for enhancing sensitivity in plasmonic sensory applications. This characteristic renders our PPA an exceptional candidate for refractive index (RI) sensing, where precision is critical. The dual-band perfect absorber (PA)-based sensor demonstrates significant RI sensitivity, with values approximately equal to 365 nm/RIU at the first absorption peak and 733 nm/RIU at the second. Our findings elucidate the exceptional potential inherent in this novel dual-band perfect absorber design. The versatility and efficiency across varied applications not only contribute to the existing body of knowledge but also pave the way for future advancements in plasmonic sensor technologies and metamaterial research.

Characterizing myocardial edema and fibrosis in hypertensive crisis with cardiovascular magnetic resonance imaging.

A hypertensive crisis is associated with an increased risk of cardiovascular events. Although altered cardiac structure, function, and myocardial architecture on cardiovascular magnetic resonance (CMR) have been associated with increased adverse events in hypertensive patients, the studies did not include patients with hypertensive crisis. Our study aimed to determine myocardial tissue characteristics in patients with hypertensive crisis using CMR imaging. Participants underwent comprehensive CMR imaging at 1.5T. The imaging protocol included cine-, T2-weighted-, contrasted- and multi-parametric mapping images. Blood and imaging biomarkers were compared in hypertensive emergency and hypertensive urgency. Predictors of myocardial edema was assessed using linear regression. The predictive value of T1- and T2 mapping for identifying hypertensive emergency (from urgency) was assessed with receiver operator characteristics curves. Eighty-two patients (48.5 ± 13.4 years, 57% men) were included. Hypertensive emergency constituted 78%. Native T1 was higher in patients with LVH compared to those without (1056 ± 33 vs. 1013 ± 40, P < 0.001), and tended to be higher in hypertensive emergency than urgency (1051 ± 37 vs. 1033 ± 40, P = 0.077). T2-w signal intensity (SI) ratio and T2 mapping values were higher in hypertensive emergency (1.5 ± 0.2 vs. 1.4 ± 0.1, P = 0.044 and 48 ± 2 vs. 47 ± 2, P = 0.004), and in patients with than without LVH (1.5 ± 0.2 vs. 1.4 ± 0.1, P = 0.045 and P = 0.030). A trend for higher extracellular volume was noted in hypertensive emergency compared to urgency (25 ± 4 vs. 22 ± 3, P = 0.050). Native T1 correlated with T2 mapping (rs = 0.429, P < 0.001), indexed LV mass (rs = 0.493, P < 0.001), cardiac troponin (rs = 0.316, P < 0.001) and NT-proBNP (rs = 0.537, P < 0.001), while T2 correlated with cardiac troponin (rs = 0.390, P < 0.001), and NT-proBNP (rs = 0.348, P < 0.001). Non-ischemic LGE pattern occurred in 59% and was 21% more prevalent in the hypertensive emergency group (P = 0.005). Our findings demonstrate that hypertensive crisis is associated with distinct myocardial tissue alterations, including increased myocardial edema and fibrosis, as detected on CMR. Patients with hypertensive emergency had a higher degree of myocardial oedema than hypertensive urgency. Further research is necessary to explore the prognostic value of these findings.

The impact of surface metallization on multilayer carbon nanotubes regarding the operational characteristics of composite electric heaters utilized for anti-icing protection

The design of energy-efficient heating techniques is emerging as a crucial scientific and technical challenge, driven by the growing focus on the advancement of the northern regions of the country, particularly the Arctic. Research in Arctic materials science, which incorporates cutting-edge techniques from various interdisciplinary fields like nanotechnology and electrotechnology, could become a key area of study for the development of these northern regions. The development of an electric heating composite material that utilizes an organosilicon elastomer as the polymer matrix and metallized multilayer carbon nanotubes (MWCNTs) serving as a conductive filler with enhanced resistance to icing enables an efficient electrothermal anti-icing system The paper presents the results of the study of an electric heater based on the wiring of an elastic composite with the effect of temperature self-regulation. For modification of the silicon-organic compound, metallized MWCNTs were used, which increased the sensitivity of heating elements to ice formation. When the ambient temperature decreases, the polymer composite has different values of electrophysical parameters, which create the effect of acceptable electrical heating concerning the ambient temperature. The research results have significant practical value, as the heating elements can have different compositions and can be operated at low temperatures. Heating elements can effectively adjust the heating mode to the ambient temperature conditions, saving electrical energy. The heating time required for the ice to melt is 210 seconds, and the dynamics of the current consumption value correlate with the ambient temperature, reflecting the effect of temperature self-regulation.

Investigating the Performance Optimization of Three‐Quantum‐Well High Electron Mobility Transistor Device: Analyzing Operational Characteristics and Gate Voltage Influence

Quantum well AlGaN/AlN/GaN high electron mobility transistor (HEMT) devices are a unique kind of semiconductor device that make use of a heterostructure made up of layers of different materials. In this study, the operational characteristics and performance optimization of HEMT devices, with a specific emphasis on the behavior of three‐quantum‐well (3QW) HEMT devices, are explored. The impact of gate voltage is explored and is observed that higher gate voltages result in lower pinch‐off voltages and higher saturation drain currents. In these findings, valuable insights for optimizing circuit designs and ensuring dependable operation across a range of electronic applications are offered. In addition, In this study, the device's ability to detect changes in gate voltage and its nonlinear characteristics is emphasized, providing valuable information for improving the device's performance. Additionally, the benefits of HEMT devices with negative threshold voltages are explored. Devices utilizing AlGaN/AlN/GaN structures demonstrate exceptional performance characteristics, such as rapid switching capabilities, high energy efficiency, and low noise performance, making them well suited for a wide range of scientific and technological applications. Finally, when comparing a QW HEMT device at different drain bias conditions (Vd = 1 V and Vd = 5 V), noticeable variations suggesting improved performance with higher drain bias.

REMaQE: Reverse Engineering Math Equations from Executables

Cybersecurity attacks on embedded devices for industrial control systems and cyber-physical systems may cause catastrophic physical damage as well as economic loss. This could be achieved by infecting device binaries with malware that modifies the physical characteristics of the system operation. Mitigating such attacks benefits from reverse engineering tools that recover sufficient semantic knowledge in terms of mathematical equations of the implemented algorithm. Conventional reverse engineering tools can decompile binaries to low-level code, but offer little semantic insight. This paper proposes the REMaQE automated framework for reverse engineering of math equations from binary executables. Improving over state-of-the-art, REMaQE handles equation parameters accessed via registers, the stack, global memory, or pointers, and can reverse engineer equations from object-oriented implementations such as C++ classes. Using REMaQE, we discovered a bug in the Linux kernel thermal monitoring tool “tmon”. To evaluate REMaQE, we generate a dataset of 25,096 binaries with math equations implemented in C and Simulink. REMaQE successfully recovers a semantically matching equation for all 25,096 binaries. REMaQE executes in 0.48 seconds on average and in up to 2 seconds for complex equations. Real-time execution enables integration in an interactive math-oriented reverse engineering workflow.

Numerical Simulation of “Submachinegun - Grenade Launcher” Dynamic System

In modern small arms, one of the most important technical characteristics is the survivability of barrel, which greatly affects the competitiveness of the product on the market. The task of increasing the survivability of the barrel of automatic small arms has not yet lost its relevance. Based on the modern nature of combat and the multitasking of combat operations, complexes of manual automatic weapons with the use of various external devices, such as sighting devices of various designs, under-barrel grenade launchers, low-noise shooting devices, etc., are currently being developed on the basis of a single reference sample. When designing new samples, several approximated mathematical models are currently used, that do not take into account the impact of external devices on the dynamic and oscillatory processes occurring during firing from modern hand-held automatic weapons. This article describes a physical and mathematical model of the dynamic interaction of an under-barrel grenade launcher and small arms (submachine gun), demonstrates a computational mathematical model for different types and methods of securing a device such as an under-barrel grenade launcher. The optimal computational model is revealed, allowing to describe the dynamic process of interaction of the system elements in the numerical simulation of the shot. Advantages and disadvantages have been identified, on the basis of which the goals and objectives of further work have been determined, consisting in studying the influence of external devices on the parameters of the barrel of automatic small arms, in order to improve the operational, tactical and technical characteristics of automatic small arms systems based on the development of a numerical and analytical approach, and a modular mathematical model of automatic small arms weapons.

Forced randomization: the what, why, and how.

When running a randomized controlled trial (RCT), a clinical site may face a situation when an eligible trial participant is to be randomized to the treatment that is not available at the site. In this case, there are two options: not to enroll the participant, or, without disclosing to the site, allocate the participant to a treatment arm with drug available at the site using a built-in feature of the interactive response technology (IRT). In the latter case, one has employed a "forced randomization" (FR). There seems to be an industry-wide consensus that using FR can be acceptable in confirmatory trials provided there are "not too many" instances of forcing. A better understanding of statistical properties of FR is warranted. We described four different IRT configurations with or without FR and illustrated them using a simple example. We discussed potential merits of FR and outlined some relevant theoretical risks and risk mitigation strategies. We performed a search using Cortellis Regulatory Intelligence database (IDRAC) ( www.cortellis.com ) to understand the prevalence of FR in clinical trial practice. We also proposed a structured template for development and evaluation of randomization designs featuring FR and showcased an application of this template for a hypothetical multi-center 1:1 RCT under three experimental settings ("base case", "slower recruitment", and "faster recruitment") to explore the effect of four different IRT configurations in combination with three different drug supply/re-supply strategies on some important operating characteristics of the trial. We also supplied the Julia code that can be used to reproduce our simulation results and generate additional results under user-specified experimental scenarios. FR can eliminate refusals to randomize patients, which can cause frustration for patients and study site personnel, improve the study logistics, drug supply management, cost-efficiency, and recruitment time. Nevertheless, FR carries some potential risks that should be reviewed at the study planning stage and, ideally, prospectively addressed through risk mitigation planning. The Cortellis search identified only 9 submissions that have reported the use of FR; typically, the FR option was documented in IRT specifications. Our simulation evidence showed that under the considered realistic experimental settings, the percentage of FR is expected to be low. When FR with backfilling was used in combination with high re-supply strategy, the final treatment imbalance was negligibly small, the proportion of patients not randomized due to the lack of drug supply was close to zero, and the time to complete recruitment was shortened compared to the case when FR was not allowed. The drug overage was primarily determined by the intensity of the re-supply strategy and to a smaller extent by the presence or absence of the FR feature in IRT. FR with a carefully chosen drug supply/re-supply strategy can result in quantifiable improvements in the patients' and site personnel experience, trial logistics and efficiency while preventing an undesirable refusal to randomize a patient and a consequential unblinding at the site. FR is a useful design feature of multi-center RCTs provided it is properly planned for and carefully implemented.

Flood vulnerability map of the Bagmati River basin, Nepal: a comparative approach of the analytical hierarchy process and frequency ratio model

AbstractThe analytical hierarchy process (AHP) and frequency ratio model (FR), along with the integration of GIS, have proven to be successful approaches for assessing flood-prone areas. However, in Nepal flood vulnerability mapping based on GIS decision analysis is limited. Thus, this study focused on comparing the data-driven FR method and expert knowledge-based AHP technique in a GIS environment to prepare a flood vulnerability map for the Bagmati River basin, helping to explore the gap in flood vulnerability mapping methodologies and approaches. By combining all class-weighted contributing factors, like elevation, precipitation, flow accumulation, drainage density, soil, distance from the river, land use land cover, normalized difference vegetative index, slope and topographic wetness index, the study evaluated the efficiency of FR and AHP in assessing flood vulnerability maps. An inventory map of floods containing 107 flood points was created. Subsequently, the flood vulnerability maps generated using FR and AHP models revealed that 9.30% and 11.36% of regions were in highly vulnerable areas, respectively. Receiver operating characteristics validated the model outcomes, indicating that the FR model’s accuracy of 91% outperformed the AHP model’s 84% accuracy. The study findings will assist decision-makers in enacting sustainable management techniques to reduce future damage in the Bagmati basin.

Collaborative optimization of multi-modal transport solutions for urban-rural bus routes.

Faced with the land use heterogeneity and trip distribution non-equilibrium along the corridor connecting urban district and rural area, the operation characteristics of the all-stop bus, the express bus and the shuttle bus running on the transportation corridor should be given full consideration, as well as the tradeoff between passenger trip cost and bus operation cost during the peak-hour period. In order to realize the reliable decision of bus resources configuration for urban-rural public transportation, a bi-objective programming model of multi-modal urban-rural bus operation scheme is established, where the decision variables include the departure frequency of different bus modals, the terminals of shuttle buses, and the stop scheme of express buses, under the constraints of departure interval, passenger volume, vehicle occupancy, section capacity usage and modal competition. To validate the feasibility of proposed optimization model, an urban-rural bus corridor from Rural Jasmine Ecological Park in Hanjiang District to West Xiangyang Bridge in Songqiao Town was chosen as a study case, and the operation organization scheme of three bus modals were solved by the mathematical solver Lingo using mixed integer programming. Meanwhile, the scheme differences under different subobjective weights were discussed, taking into account the uncertain passenger demand and operation supply. The result shows that the increase of passenger trip cost weight will increase the departure frequency of all three bus modals, while the increase of operation cost weight will decrease the total operating vehicles, but the stop frequency at middle stations for express buses will increase accordingly. Compared to the current operation scheme, the optimized scheme can greatly enhance the section capacity usage at a slight sacrifice of passenger trip time with fewer bus vehicles.

Surgical complications after targeted muscle reinnervation at a safety-net hospital.

BACKGROUND Targeted muscle reinnervation (TMR) and regenerative peripheral nerve interface (RPNI) can reduce rates of neuroma formation and phantom limb pain (PLP) after lower extremity (LE) amputation. However, these techniques have not been examined for patients at safety-net hospitals. The purpose of this study is to examine surgical complication rates after TMR and/or RPNI at a safety-net hospital. METHODS This was a retrospective review of patients >18 years who had prior above- (AKA) or below-knee (BKA) guillotine amputation and underwent stump formalization with TMR and/or RPNI from 2020 to 2022. Demographics, medical history, operative and postoperative characteristics were collected. The primary outcome was any surgical complication, defined as infection, dehiscence, hematoma, neuroma, or reoperation. Univariate analysis was conducted to identify variables associated with surgical complications and PLP. RESULTS Thirty-two patients met inclusion criteria. The median age was 52 years, and 75% were male. BKA was the most common indication for formalization (93.8%). Most patients (56.3%) had formalization with TMR and RPNI, 34.4% patients had TMR only, and 9.4% had RPNI alone. The incidence of postoperative complications was 46.9%, with infection being the most common (31.3%). There was no significant difference in demographics, medical history, or operative characteristics between patients who did and did not have surgical complications. However, there was a trend toward higher rates of PLP in patients who had a postoperative wound infection (odds ratio 6.2, 95% CI 0.70-84.6, p = 0.06). CONCLUSION Overall complication rates after LE formalization with TMR and/or RPNI at our safety-net hospital were similar to what has been reported in the literature. Given the benefits of these surgical techniques, including reduced chronic pain and decreased healthcare cost, we believe that these techniques should be widely adopted at other safety-net hospitals.

The Influence of Thickness and Spectral Properties of Green Color-Emitting Polymer Thin Films on Their Implementation in Wearable PLED Applications

A systematic investigation of optical, electrochemical, photophysical, and electrooptical properties of printable green color-emitting polymer (poly(9,9-dioctylfluorene-alt-bithiophene)) (F8T2) and spiro-copolymer (SPG-01T) was conducted to explore their potentiality as an emissive layer for wearable polymer light-emitting diode (PLED) applications. We compared the two photoactive polymers in terms of their spectral characteristics and color purity, as these are the most critical factors for wearable lighting sources and optical sensors. Low-cost, solution-based methods and facile architecture were applied to produce rigid and flexible light-emitting devices with high luminance efficiencies. Emission bandwidths, color coordinates, operational characteristics, and luminance were also derived to evaluate the device’s stability. The tuning of emission’s spectral features by layer thickness variation was realized and was correlated with the interplay between H-aggregates and J-aggregates formations for both conjugated polymers. Finally, we applied the functional green light-emitting PLED devices based on the two studied materials for the detection of Rhodamine 6G. It was determined that the optical detection of the R6G photoluminescence is heavily influenced by the emission spectrum characteristics of the PLED and changes in the thickness of the active layer.

An experimental study of the response characteristics of end milling operations and their finite element simulation

The present study investigates the effect of milling parameters on cutting forces and performance characteristics in end mill operations using two different types of end milling tools. The end milling experiments were performed on AA7075-T6 grade aluminium alloy using a vertical milling machine fitted with a Kistler dynamometer to acquire the data of cutting forces during the milling operation. A matrix of process parameters was created by varying spindle rotational speed in the range of 500–1200 rpm while the feed rate was kept between 10 and 30 mm/min, keeping a maximum depth of cut of 4 mm. The data obtained from the experimental results were analysed and validated by simulation using the DEFORM-3D software facility. The experimental results reflect that with the increase in cutting speed, the cutting force first increases and then decreases, while an increase in feed rate enhances the cutting forces. The combination of high cutting speed with low feed rate was found to be suitable as the force required in this case exhibits a minimum to achieve both efficiency and machinability for a tool. Validated experimental results can be useful for finding new combinations of parameters in the defined parameter range for milling applications.

Extracellular Vesicle Characteristics in Local Fluid and Plasma Measured by Nanoparticle Tracking Analysis Can Help Differentiate High-Grade Serous Carcinoma from Benign Ovarian Pathology

Background: High-grade serous carcinoma (HGSC) is the most lethal of gynecological cancers in developed countries. It usually presents late with non-specific symptoms and most cases are diagnosed at an advanced stage, with 5-year overall survival being around 40%. Biomarkers for screening and early diagnosis of this aggressive disease are, thus, a research priority. Extracellular vesicles (EVs) that reflect the cell of origin and that can be isolated from local fluid and plasma by minimally invasive liquid biopsy are such promising biomarkers. Besides EV concentration and molecular profile, which have been the main focus of research for many years, recent studies have also called attention to EV size distribution. The aim of our study was to evaluate the potential of EV concentration and size distribution in local fluid and plasma as diagnostic biomarkers for HGSC. Methods: Paired pretreatment ascites and plasma samples from 37 patients with advanced HGSC and paired pretreatment free peritoneal fluid (FPF) and plasma samples from 40 controls with benign ovarian pathology (BOP) were analyzed using nanoparticle tracking analysis (NTA). Results: We observed a significant difference in EV concentration in local fluid, but not in plasma, between HGSC patients and the control group. We also found a significant difference in EV size distribution in both local fluid and plasma between HGSC patients and the control group. The receiver operating characteristics (ROC) curve analysis of EV characteristics showed excellent diagnostic performance for the mode, D10, and D50 in local fluid and acceptable diagnostic performance for EV concentration and mean EV size in local fluid, as well as for the mode and D10 value in plasma. Conclusions: The results of our study show that EV concentration in local fluid and more importantly EV size distribution in both local fluid and plasma are significantly changed in the presence of HGSC. Future research of size-dependent molecular profiling of EVs could help identify novel diagnostic biomarkers for HGSC.

Control Voltage Effect on Operational Characteristics of Vehicle Magnetorheological Damper

Considering the increasingly large-scale application of magnetic fluids in various industries, we can confidently state that in the near future magnetorheological dampers will be widely used in adaptive automotive suspensions due to their operational flexibility and simplicity of controlling damping forces by changing the magnetic fluid properties according to parameters of surrounding electromagnetic field. The antivibration efficiency during operation is achieved by regulating the hydraulic resistance of the “magnetic” shock absorber by applying voltage to the windings of its coil. In addition to the physical properties of the oil used in the “magnetic” shock absorber, the viscosity of the working magnetorheological fluid is greatly influenced by the shape of the control signal. The paper focuses on the theoretical aspects of constructing a mathematical model of ac magnetorheological damper and presents the results of a computer experiment to assess effectiveness of its use as part of the adaptive suspension a passenger vehicle. In this case, the actual parameters of the “magnetic” shock absorber, used in modeling the dynamic process, were determined experimentally on a test bench, and the adequacy of the developed mathematical model was confirmed by the results of a semi-natural experiment. Using a verified model, the magnetorheological damper characteristics were obtained and compared for various forms of control signal, including rectangular voltage pulses of various frequencies and duty cycles, sinusoidal pulses and constant voltage signals. The analysis of the antivibration efficiency was carried out on the basis of the developed “quarter” model of a semi-active car suspension with a verified submodel of a magnetorheological damper integrated into its structure. Moreover, the simulation scenarios were based on the selected strategy for controlling the voltage supplied to the windings of the “magnetic” shock absorber. As the results of theoretical and experimental studies have shown in terms of energy consumption, expansion of the working area of the damping characteristic and achieving smooth control of the damping force, the most effective is the use of a sinusoidal pulse voltage signal in the control circuit, which ensures a reduction in both the amplitude and damping time of oscillations. However, when de-signing and manufacturing a controller, creating a pulse modulator for generating sinusoidal pulses coinciding in phase and frequency with the vibrations of the car body is very difficult due to the random nature of external disturbances from the road surface. When a constant voltage is applied to the magnetorheological damper winding, the damping properties of the suspension are also improved compared to the basic design based on a traditional hydraulic shock absorber. Moreover, there is a proportional relationship between the voltage supplying the damper, the amplitude and damping time of the vibrations of the car body is observed. An increase in the control signal voltage from 1 to 2 V leads, in comparison with passive control of a magnetic shock absorber, to a decrease in the maximum amplitude of vibrations of the car body by 6.25 and 11.25 %, respectively, and a decrease in the vibration damping time by 0.72 and 1.41 s.

Aggressive Behaviour Risk Assessment Tool for Hospitalised Patients in Non-Psychiatric Inpatient Units.

To refine and validate an electronic version of the Aggressive Behaviour Risk Assessment Tool (ABRAT) and determine the sensitivity and specificity for identifying potentially violent patients in non-psychiatric inpatient units. A prospective cohort study design was used. All patients admitted or transferred to three inpatient units of an acute care hospital in Nebraska, USA, from 7 February to 9 April 2023, were included. The 10-item ABRAT assessments were performed daily for the first 3 days of admission. The violent events were collected until discharge in three categories: Physical aggression towards others, physical aggression towards property and verbal intimidation/threat towards others. Kendall's tau tests and a multivariate logistic regression procedure were performed to select a parsimonious set of items that best predict violent events. Of 1179 patients, 69 had ≥1 violent event (5.9%). The revised six-item tool with item weighting was named ABRAT for Hospitalised Patients (ABRAT-H). The area under the curve from the Receiver Operating Characteristics analysis was 0.82. The sensitivity and specificity at a cutoff score of two were 68.1% and 85.2%, respectively. As ABRAT-H scores increased, the percentage of violent patients also increased and for patients with scores ≥5, 55.2% became violent. ABRAT-H appears to be useful for identifying potentially violent patients in non-psychiatric inpatient units with satisfactory sensitivity and specificity. The availability of ABRAT-H may help provide focused preventive measures that target patients at high risk for violence and reduce violent events. A majority of the nursing workforce is employed in acute care hospital setting, and the availability of ABRAT-H can further enhance the culture of a safe work environment and have positive impacts not only on the nurses' physical and mental health but also on the quality of patient care. We have adhered to relevant STROBE guidelines for reporting observational studies. No Patient or Public Contribution.