Critical Value Research Articles

Design and build an airbag system for elderly fall protection using the MPU6050 sensor module

The use of technology has a significant impact to reduce the consequences of accidents. Sensors, small components that detect interactions experienced by various components, play a crucial role in this regard. This study focuses on how the MPU6050 sensor module can be used to detect the movement of people who are falling, defined as the inability of the lower body, including the hips and feet, to support the body effectively. An airbag system is proposed to reduce the impact of a fall. The data processing method in this study involves the use of a threshold value to identify falling motion. The results of the study have identified a threshold value for falling motion, including an acceleration relative (AR) value of less than or equal to 0.38 g, an angle slope of more than or equal to 40 degrees, and an angular velocity of more than or equal to 30 °/s. The airbag system is designed to inflate faster than the time of impact, with a gas flow rate of 0.04876 m3 /s and an inflating time of 0.05 s. The overall system has a specificity value of 100%, a sensitivity of 85%, and an accuracy of 94%.

Role of beta-hydroxybutyrate measurement in the evaluation of plasma glucose concentrations in newborn infants

ObjectiveThe Glucose in Well Babies (GLOW) Study showed that there are two phases of low glucose concentrations in healthy newborn infants: an initial phase in which plasma concentrations of ketones...

Advancements in Laplace transform techniques: Performing non-parametric hypothesis testing on real-world data through statistical analysis

This research delves into the exploration of a statistical testing approach grounded in Laplace transform techniques specifically tailored for the New Better than Used Laplace transform order (NBUL) class of life distributions. The developed test exhibits versatility, accommodating both complete and censored data, and critical values are systematically calculated for its application. Beyond the methodological presentation, our study investigates the test’s statistical power and explores Pitman’s asymptotic efficiency concerning various alternative distributions. Comparative analyses with other tests within the same class contribute to a comprehensive understanding of the proposed approach. To demonstrate practical applicability, we apply this novel testing technique to authentic engineering and medical datasets. The outcomes of these applications serve as illustrative examples, showcasing the effectiveness and relevance of the proposed methodology in real-world scenarios.

Switching of magnetic bilayer nanotube ring with antiferromagnetically coupled layers in an annular field

The magnetization switching behavior of magnetic nanotube rings with core–shell structure is investigated by solving the Landau-Lifshitz-Gilbert (LLG) equation, focusing on the effects of the magnetic structure, interfacial exchange interactions, anisotropy constants, and transverse field on the coercivity of the system. The reduction of the coercivity of the magnetic nanorings can increase the magnetization switching rate and reduces the energy consumption when the magnetic nanorings are used as magnetic storage units. In the study, it is found that the antiferromagnetic exchange interaction between the spins in the core can greatly reduce the coercivity of the system, and the coercivity decreases with the increase of the interface exchange interaction. When the anisotropy constant of the antiferromagnetic core gradually increases, the coercivity of the system varies nonlinearly and a point of minima occurs. Finally, the effect of the transverse magnetic field on the hysteresis behavior of the system is also discussed, and it is found that the coercivity of the system decreases gradually with the increase of the transverse magnetic field, but the hysteresis loop of the system is distorted when the critical value is exceeded.

Computational study of a thin film flow over a topographical feature using phase-field lattice Boltzmann method

The study employs the phase-field lattice Boltzmann method (PFLBM) to explore the dynamics of a thin film flowing over a topographical feature such as a mound or a trench. The mesoscopic nature of PFLBM makes it a suitable technique for problems involving tracking the evolution of a liquid–air interface. PFLBM simulation results are validated with experimental and analytical results confirming the viability of the numerical approach for such problems. The effect of changing the topographical height, aspect ratio, viscosity ratio, and presence of multiple mounds on the film profiles are systematically analyzed. It is observed that a steady-state solution could not be obtained for large height topographical features. The transition from a steady-state interfacial pattern to an unsteady-steady state is found to depend on the width of the topography. Geometry-based condition is employed to deal with the contact points present in the film dynamics beyond rupture. For large contact angles, the unsteady cases result in film rupture and form a continuous array of droplets of equivalent dimensions at a periodic interval. Increasing the aspect ratio reduces the width of the capillary ridge formed above the topographical feature, while the viscosity ratio reduces the maximum height of the ridge. The shapes of the capillary ridges formed over multiple mounds in the flow direction are independent if the separation between the successive mounds is beyond a critical value. This critical value strongly depends on the capillary number and is independent of the dimensions of the mound.

Effect of Different Temperature and Nuclear Data Libraries in Criticality Calculations of 300 MWt Molten Salt Reactor

The Molten Salt Reactor (MSR) is a type of reactor in which coolant and fuel are blended with liquid salts. Liquid fuel enhances heat transfer and temperature control, establishing the MSR as one of the Generation IV reactor types. This study aims to analyze the impact of temperature variations on MSR reactor criticality and evaluate the effect of different nuclear data libraries, namely JENDL 3.2, JENDL 3.3, and JENDL 4.0, in neutron analysis. The observed temperature variations are 600 K, 700 K, 833 K, 903 K, and 1000 K. The analysis spans low to operational temperatures to comprehend reactor performance under differing thermal conditions. The study is conducted on a 300 MWTh MSR design, utilizing SRAC2006 with PIJ and CITATION modules for calculations. The results reveal the impact of temperature variations and nuclear data library disparities on reactor criticality. The outcomes demonstrate that higher temperatures correspond to lower values of the effective multiplication factor. At lower temperatures, neutrons experience greater moderation compared to higher temperatures. As a result, a higher number of thermal neutrons influences an increased probability of fission reactions within the reactor. Different nuclear data libraries also yield varied criticality values due to differing cross-sectional areas and quantities of data within each JENDL library. JENDL 4.0 generates the highest criticality value, attributed to elevated cross-sectional regions of each respective nuclear data entry and a greater quantity of nuclear data entries than JENDL 3.2 and JENDL 3.3.

Imperfectly conducting eigenflows in a vertical fluid layer

The stability of buoyant flow in an infinite vertical fluid layer bounded by imperfectly conducting rigid walls, called imperfectly conducting eigenflows, is discussed. The third kind boundary conditions describing heat transfer to the external environment are applied to perturbations in temperature. The linear stability analysis is carried out numerically by employing the Chebyshev collocation method. Instability arises when the Grashof number G exceeds its critical value, which depends on the Prandtl number Pr and the Biot number Bi. It is found that the onset of instability changes dramatically depending on the magnitude of Prandtl and Biot numbers particularly when the instability is through the traveling-wave mode. The numerical results show that the Biot number plays a pivotal role in determining the transition Prandtl number PrT at which the instability switches over from one mode to another mode. The novel outcomes suggest the presence of a single PrT for Bi<2.1739 while three distinct values of PrT for Bi≥2.1739. The departure from the conventional single value typically observed at isothermal boundaries signifies the complexity of the instability mechanism.

Polarized images of charged particles in vortical motions around a magnetized Kerr black hole

In this work, we study the images of a Kerr black hole (BH) immersed in uniform magnetic fields, illuminated by the synchrotron radiation of charged particles in the jet. We particularly focus on the spontaneously vortical motions (SVMs) of charged particles in the jet region and investigate the polarized images of electromagnetic radiations from the trajectories along SVMs. We notice that there is a critical value ω_c for charged particle released at a given initial position and subjected an outward force, and once |qB_0/m|=|ω_B|>|ω_c| charged particles can move along SVMs in the jet region. We obtain the polarized images of the electromagnetic radiations from the trajectories along SVMs. Our simplified model suggests that the SVM radiations can act as the light source to illuminate the BH and form a photon ring structure.

Comparative multimodal sensory testing in multifocal motor neuropathy and multifocal variant of chronic inflammatory demyelinating polyradiculoneuropathy

Comparative multimodal sensory testing in multifocal motor neuropathy and multifocal variant of chronic inflammatory demyelinating polyradiculoneuropathy

Aveir VR real-world performance and chronic pacing threshold prediction using mapping and fixation electrical data.

Aveir VR performance and predictors for its pacing threshold (PCT) in a real-world cohort were investigated. Electrical measurements at various stages of an Aveir VR implant were prospectively collected. Predictors for 3-month PCT were studied. A retrospective cohort of consecutive 139 Micra implants was used to compare the PCT evolution. High PCT was defined as ≥1.5 V, using a pulse width of 0.4 ms for Aveir and 0.24 ms for Micra. Excellent PCT was defined as ≤0.5 V at the respective pulse width. Among the 123 consecutive Aveir VR implant attempts, 122 (99.2%) were successful. The majority were of advanced age (mean 79.7) and small body size (mean BSA 1.60). Two patients (1.6%) experienced complications, including one pericardial effusion after device reposition and one intraoperative device dislodgement. Eighty-eight patients reached a 3-month follow-up. Aveir 3-month PCT was correlated with impedance at mapping (P = 0.015), tether mode (P < 0.001), end-of-procedure (P < 0.001), and mapping PCT (P = 0.035), but not with PCTs after fixation (P > 0.05). Tether mode impedance >470 ohms had 88% sensitivity and 71% specificity in predicting excellent 3-month PCT. Although it is more common for Aveir to have high PCT at end of procedure (11.5% for Aveir and 2.2% for Micra, P = 0.004), the rate at 3 months was similar (2.3% for Aveir and 3.1% for Micra, P = 1.000). Aveir VR demonstrated satisfactory performance in this high-risk cohort. Pacing thresholds tend to improve to a greater extent than Micra after implantation. The PCT after fixation, even after a waiting period, has limited predictive value for the chronic threshold. Low-mapping PCT and high intraoperative impedance predict chronic low PCT.

Efficacy of povidone-iodine nasal rinse and mouth wash in COVID-19 management: a prospective, randomized pilot clinical trial (povidone-iodine in COVID-19 management)

Objectives/HypothesisTo assess the efficacy of 0.23% povidone-iodine (PVP-I) nasal rinses and mouth washes on detectability of the coronavirus disease 2019 (COVID-19) virus and cycle threshold (Ct) values in nasopharyngeal swabs.Study designThis was an open-label, prospective, randomized, placebo-controlled clinical trial.SettingThe study was conducted in King Saud University Medical City, Riyadh, Saudi Arabia, from August 2021 to July 2022.MethodsParticipants diagnosed with SARS-CoV-2 were randomly assigned to one of three groups, with participants receiving either 0.23% PVP-I, 0.9% normal saline (NS) nasal rinses and mouth washes, or no intervention (control group). Nasopharyngeal swabs were taken 4, 8, 12, and 18 days after the first swab to measure the detectability of the virus and the Ct.ResultsA total of 19 participants were involved in this study. The mean viral survival was 9.8, 12, and 12.6 days for the PVP-I, NS, and control groups, respectively, with a statistically significant difference (p = 0.046). The Ct mean values were 23 ± 3.4, 23.5 ± 6.3, and 26.3 ± 5.9 at the time of recruitment and 25.2 ± 3.5, 15 ± 11.7, and 26.9 ± 6.4 after 4 days for the PVP-I, NS, and control groups, respectively.ConclusionsWhen used continuously at a concentration of 0.23%, PVP-I showed promising results in terms of decreasing the pandemic burden by reducing the period of infectiousness and viral load. However, the use of PVP-I did not result in significantly different changes in the quality-of-life parameters in recently vaccinated and mild COVID-19 patients.

Association of RT-qPCR Ct Values and Disease Severity among COVID-19 Patients Visiting a Tertiary Care Hospital in Nepal

COVID-19 pandemic due to SARS-CoV-2 has been one of the major global health issues of this aeon. The aim of this study was to evaluate the association of SARS-CoV-2 cycle threshold (Ct) values with multiple factors among COVID-19 patients visiting a tertiary care hospital in Sudurpashchim province of Nepal. A retrospective analysis was performed on the data of randomly selected COVID-19 cases among the total RT-qPCR tested patients from March 2020 to April 2022. The Ct values at the time of patient admission and their clinical outcomes (discharge or death) were compared. Among the COVID-19 patients, survivor group had significantly higher initial Ct value compared to non-survivors [median Ct values 23.21 and 24.39 (P &lt; 0.0001)]. Selected haematological parameters; white blood cells (P&lt;001), neutrophils (P&lt;001), and monocytes (P&lt;0.0001), and all the biochemical parameters were significantly different between these two groups (p &lt; 0.005). Furthermore, significantly increased CRP (61.54±63.00, P&lt;0.0017), D-dimer levels (0.8979± 1.480, P&lt;0.0001), creatinine (0.7931±0.2551, P&lt;0.0001), monocytes (0.6782±0.7981, P&lt;0.0001), and random blood sugar (152.4±34.32, P&lt;0.0001) were observed among non-survivors indicating as cause of disease severity in COVID-19. The findings of this study imply that the Ct value, CRP and D-dimer levels could be a crucial marker for the early detection of severe COVID-19 patients or those at higher risk of developing severe disease. This will eventually help to identify cases requiring immediate and critical medical care and reduce mortality.

Possibility of massless Dirac fermions in an Aubry–André–Harper potential

In this study, we present a one-dimensional tight-binding model designed to explore the impact of electric fields on an incommensurate quantum system. We specifically focus on the Aubry–André–Harper model, a quasiperiodic model known to exhibit a metal–insulator transition at a critical potential value of λc = 2. This model combines Anderson and Aubry–André–Harper localization phenomena in a quantum system, leading to intriguing effects on the lattice band structure upon the application of an electric field F to the Aubry–André–Harper potential. Our investigation reveals that by choosing a specific value for the applied electric field, it becomes feasible to generate effective massless Dirac fermions within our Aubry–André–Harper system. Furthermore, we note that the extension or localization of the massless particle wave function is contingent upon the potential strength value λ within our incommensurate model. Importantly, our findings highlight the potential for detecting this intriguing phenomenon through experimental means.

Non-linear electro-rheological model of a membrane immersed in Tanner-Power law fluids applied to outer hair cells: Shear-thinning mechanisms

Flexoelectric actuation employs an applied electric field to induce membrane curvature, which is the mechanism utilized by the outer hair cells (OHC) present in the inner ear. The model developed for this study, representing the OHC, integrates two key components: (i) an approximation of the flexoelectric membrane shape equation for circular membranes attached to the inner surface of a circular capillary, and (ii) the coupled capillary flow of contacting liquid viscoelastic phases characterized by the Tanner-Power law rheological equation of state. A second-order non-linear differential equation for average curvature has been derived, and a robust numerical method has been programmed. This model simplifies to a linear model used previously. The main challenge involves identifying and describing the enhancement in curvature change rate. It was observed that low symmetry, low viscosity, and soft membrane and shear-thickening behavior of the phases enhance the curvature change rate. Additionally, there exists a critical electric field frequency value that maximizes the curvature change rate (resonance effect). The current theory, model, and computational simulations add to the ongoing development comprehension of how biological membrane shape actuation through electromechanical couplings.

Virtual clinical QT exposure-response studies – A translational computational approach

Background and purposeA recent paradigm shift in proarrhythmic risk assessment suggests that the integration of clinical, non-clinical, and computational evidence can be used to reach a comprehensive understanding of the proarrhythmic potential of drug candidates. While current computational methodologies focus on predicting the incidence of proarrhythmic events after drug administration, the objective of this study is to predict concentration-response relationships of QTc as a clinical endpoint. Experimental approachFull heart computational models reproducing human cardiac populations were created to predict the concentration-response relationship of changes in the QT interval as recommended for clinical trials. The concentration-response relationship of the QT-interval prolongation obtained from the computational cardiac population was compared against the relationship from clinical trial data for a set of well-characterized compounds: moxifloxacin, dofetilide, verapamil, and ondansetron. Key resultsComputationally derived concentration–response relationships of QT interval changes for three of the four drugs had slopes within the confidence interval of clinical trials (dofetilide, moxifloxacin and verapamil) when compared to placebo-corrected concentration-ΔQT and concentration-ΔQT regressions. Moxifloxacin showed a higher intercept, outside the confidence interval of the clinical data, demonstrating that in this example, the standard linear regression does not appropriately capture the concentration-response results at very low concentrations. The concentrations corresponding to a mean QTc prolongation of 10 ms were consistently lower in the computational model than in clinical data. The critical concentration varied within an approximate ratio of 0.5 (moxifloxacin and ondansetron) and 1 times (dofetilide, verapamil) the critical concentration observed in human clinical trials. Notably, no other in silico methodology can approximate the human critical concentration values for a QT interval prolongation of 10 ms. Conclusion and implicationsComputational concentration-response modelling of a virtual population of high-resolution, 3-dimensional cardiac models can provide comparable information to clinical data and could be used to complement pre-clinical and clinical safety packages. It provides access to an unlimited exposure range to support trial design and can improve the understanding of pre-clinical-clinical translation.

Self-assessment questionnaire development for soft skills competency and core value evaluations

Soft skills play a vital role for providing excellent customer service in the healthcare setting. This study aims to develop and assess the instrument validity and reliability before measuring the levels of soft skills competency and core value internalization on staffs at the Sultan Ahmad Shah Medical Centre @International Islamic University Malaysia (SASMEC@IIUM). A self-assessment questionnaire was developed through three phases. The first phase involved reviewing and identifying relevant literatures and existing soft skills assessment instruments through bibliographic searches and expert consultations. A conceptual model was then established based on the selected conceptual frameworks after determining all relevant soft skill domains. The second phase involved generating relevant items, removing duplicate or irrelevant items, and appraising the content validity by three experts. The third phase was data collection, wherein the finalized instrument was distributed to 32 staff of SASMEC@IIUM via google forms. The instrument reliability was investigated through internal consistency reliability or Cronbach’s alpha, with all items, except for the construct ‘gratitude’, achieving acceptable values by exceeding the threshold value of 0.7. Subsequently, two gratitude items were removed from the questionnaire. The current instrument and theoretical framework employed in the self-assessment questionnaire development are valid and reliable for the actual application.

Study of SVOM/ECLAIRs inhomogeneities in the detection plane below 8 keV and their mitigation for the trigger performances

Context. The Space-based multi-band astronomical Variable Objects Monitor is a Chinese-French mission dedicated to the study of the transient sky. It is scheduled to start operations in 2024. ECLAIRs is a coded-mask telescope with a large field of view. It is designed to detect and localize gamma-ray bursts in the energy range from 4 keV up to 120 keV. In 2021, the ECLAIRs telescope underwent various calibration campaigns in vacuum test-chambers to evaluate its performance. Between 4 and 8 keV, the counting response of the detection plane shows inhomogeneities between pixels from different production batches. The efficiency inhomogeneity is caused by low-efficiency pixels (LEPs) from one of the two batches, together with high-threshold pixels (HTPs) whose threshold was raised to avoid cross-talk effects. In addition, some unexpected noise was found in the detection plane regions close to the heat pipes. Aims. We study the impact of these inhomogeneities and of the heat-pipe noise at low energies on the ECLAIRs onboard triggers. We propose different strategies in order to mitigate these impacts and to improve the onboard trigger performance. Methods. We analyzed the data from the calibration campaigns and performed simulations with the ground model of the ECLAIRs trigger software in order to design and evaluate the different strategies. Most of the impact of HTPs can be corrected for by excluding HTPs from the trigger processing. To correct for the impact of LEPs, an efficiency correction in the shadowgram seems to be a good solution. An effective solution for the heat-pipe noise is selecting the noisy pixels and ignoring their data in the 4–8 keV band during the data analysis. Results. The trigger threshold is the minimum value of the signal-to-noise ratio that is required to claim that ECLAIRs has detected a candidate event that is not related to a background fluctuation. After introducing the efficiency inhomogeneity in the imaging simulation, the trigger threshold in the 4–8 keV band increased by a factor of 5.75 times and 1.43 times due to the impact of HTPs and LEPs, respectively, in the worst case (on a timescale of about 20 min). The trigger threshold value was restored to its normal value after we applied an efficiency-correction method. Introducing the heat-pipe noise in our simulations in the worst case (timescale of about 20 min) resulted in an increase in the trigger threshold of approximately 100% in the 4–8 keV band compared to observations without heat-pipe noise. Moreover, even with this increased threshold, we estimated a false-trigger rate of 99.26% in the 4–8 keV band and 4.44% in the 4-120 keV band. By accepting a loss of 2.5-5% noisy pixels in the 4–8 keV energy band, we can prevent false triggers caused by heat-pipe noise and reduce the threshold increment to about 20% for the longest timescale (about 20 min) of the ECLAIRs trigger in the 4–8 keV range.

Clinical Performance of BALF Droplet Digital PCR for Differential Diagnosis of Pneumocystis jirovecii Pneumonia and Pneumocystis jirovecii Colonization

BackgroundAccurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment. MethodsFrom September 2016 to June 2022, 89 immunocompromised patients with unexplained lung infiltrates and clinical suspicion of Pj pneumonia were enrolled at Peking University People's Hospital. Bronchoalveolar lavage fluid (BALF) of these patients were detected by quantitative PCR (qPCR) and droplet digital PCR (ddPCR). ResultsThe performance of ddPCR was superior to qPCR in detecting Pj infection. Area under the curve was 0.97 (95%CI: 0.94–1) for ddPCR of the BALF in all patients. The optimal threshold value for discriminating Pj infection from colonization was 13.98 copies/test, with a sensitivity of 97.96%, specificity of 85.71%. No obvious correlation between ddPCR copy number and disease severity was observed. ConclusionBALF ddPCR exhibits robust potential in detecting Pj and effectively discriminating colonization and infection.

Predicting an increased risk of severe clinical mastitis and economic loss using a threshold value of bovine leukemia virus proviral load.

To establish a threshold value of bovine leukemia virus (BLV) proviral load (PVL) to identify increased risk of severe clinical mastitis, and to examine the prognosis and economic loss of clinical mastitis based on the newly established PVL cut-off value. 97 lactating Holstein cows with clinical mastitis. Blood and milk samples were collected aseptically from each cow. Youden index was used for receiver-operating characteristic curve analysis with the severity rate of clinical mastitis as the dependent variable and PVL as an independent variable. PVL cut-off value was used as a criterion to compare the severity rate of clinical mastitis, percentage of cows with and without systemic treatments, number of treatments, cost of treatment, and prognosis. PVL cut-off value was 17.8 copies/10 ng DNA for the dependent variable MILD vs SEVERE. The severity rate of clinical mastitis, percentage of cows given systemic treatments, and technical fees for medical treatment were significantly higher in the group above the PVL cut-off value than in the group below the PVL cut-off value and the negative group. Number of treatments was significantly higher in the group above the cut-off value than in the group below the cut-off value. There was no significant difference in prognosis after mastitis among the 3 groups. These results suggested that PVL cut-off value of 17.8 copies/10 ng DNA was a useful threshold for increased economic losses in BLV-infected cows; it may also serve as a new standard value for the detection and culling of BLV-infected cows in Japan.

Stress hyperglycemia ratio linked to worse prognosis in Cardiac Intensive Care Unit patients: A retrospective observational study

AimsThis study aimed to delineate correlation between stress hyperglycemia ratio (SHR) and clinical outcomes among patients in the cardiac intensive care unit (CICU). MethodsParticipants were categorized based on their SHR threshold values. Key outcomes were short-term mortality and major adverse cardiovascular events (MACEs) at 1-year follow-up. The association between SHR and outcomes was estimated using inverse probability of treatment weighting (IPTW) and Kaplan-Meier analyses. The C-statistic was used to gauge the predictive capability of SHR. ResultsThe study included 1,133 patients from the Medical Information Mart for Intensive Care IV and 412 from the Second Affiliated Hospital of Wenzhou Medical University. Kaplan-Meier curves revealed that individuals with elevated SHR exhibited higher 90-day mortality and MACEs. When considering SHR levels and diabetes status simultaneously, those with increased SHR but non-diabetes had the highest 90-day mortality and MACEs. SHR was associated with short-term mortality and MACEs (HRadjusted 1.63 95%CI 1.15–2.30; HRIPTW 1.47 95%CI 1.05–2.05). Upon integrating SHR into the foundational model, the C-statistic was 0.821, outperforming other hyperglycemia metrics. ConclusionSHR is a valuable indicator for predicting poor outcomes in CICU patients. Its utility spans potential risk stratification and offers insights for tailoring prognostic treatments to CICU patients.