Search Results (502,668)

MEMS (microelectromechanical system) resonators, meticulously fabricated by advanced lithographic and etching processes, have become indispensable technological cornerstones across modern sensing, time-keeping and actuation applications. Yet, realising 3D coupled architectures for these silicon-based resonators remains a fundamental microfabrication challenge, limiting the toolkit of exploitable dynamic phenomena to the in-plane and flexural modes. Nature, however, through 200 million years of evolutionary refinement, has nano-engineered a ready-made solution: the diatom frustule made from biosilica (SiO${}_2$), a robust material with mechanical properties well-suited to micro-mechanical resonator applications. Unlike planar MEMS counterparts, frustules are typically dual-membrane structures, vertically coupled by a girdle band, introducing complex 3D coupling dynamics that are prohibitively complex to achieve with MEMS fabrication. This paper explores the analytical and numerical modelling of a typical circular frustule’s dynamic behaviour. Alongside the typical transverse modes expected from MEMS resonators, the 3D coupled structure also exhibits unique girdle band tilt modes, exclusively activated by antisymmetric excitations. Collectively, the presence of partial mode localisation, mechanical energy amplification through the low-inertia girdle band, and rotational–transverse modal coupling, demonstrates the diatom frustule to be a dynamically rich resonator. This establishes the theoretical framework for exploiting the diatom frustule as a novel bio-inspired and bio-derived 3D resonator building block. Full article

Background/Objectives: Catheter-appropriateness audits report a single rate without a measure of its reliability. We measured how far an emergency department (ED) estimate depends on the clinician applying the checklist, and which items carry that dependence. Methods: We enrolled 117 consecutive adults catheterized in a tertiary ED between 21 January and 21 May 2026. Three emergency physicians independently classified every patient against a ten-item checklist drawn from the 2009 CDC/HICPAC guideline and the Ann Arbor criteria. A designated senior rater served as comparator, a clinical judgment rather than a criterion standard. We computed standalone rates, per-item Fleiss’ κ and Gwet’s AC1, patient-level agreement, and a post hoc counterfactual item-replacement analysis. Results: Ten patients (8.5%, 95% CI 4.7–15.0) had no valid indication according to the senior rater. Auditing alone, the two index raters would have reported 0.9% and 25.6%. Pooled agreement over 1170 patient-by-indication decisions was substantial by κ (0.630 and 0.707) and almost perfect by AC1 (0.885 and 0.925); excluding the complementary item changed neither. Patient-level agreement was lower (three-rater κ 0.199, AC1 0.792). Disagreement concentrated in hourly urine-output monitoring (AC1 0.617) and neurogenic bladder, endorsed in 44 patients by one rater and none by another (AC1 0.668). That item accounted for 48% of one rater’s excess endorsements; replacing that rater’s item-5 ratings with the senior rater’s narrowed the between-rater range from 30-fold to 6-fold. Conclusions: In this cohort the audit rate was rater-dependent, and the dependence concentrated in identifiable checklist items. Item-level operational definitions and prospective calibration should be evaluated as strategies for improving audit reliability, and per-item agreement should be reported with a prevalence-robust coefficient alongside κ. Full article

This study evaluated the potential of Nanche seeds as a bio-adsorbent for removing TA from aqueous solutions. Additionally, we inferred the interaction mechanisms involved in the adsorption process from physicochemical evidence, isotherm modelling, and ADI analysis. The Langmuir model best fit the experimental data (R² = 0.999) across temperatures (20–60 °C). Thermodynamically, the process was endothermic and spontaneous, (∆H° = 10.11 ± 0.45 kJ/mol and ∆G° = −28.58 ± 1.03 kJ/mol), indicating that the interaction mechanisms were physical. The value of ∆S° (0.116 ± 0.003 kJ/mol·K), the Freundlich constant (n > 1), and data derived from ADI analysis of SEM micrographs that support the increased complexity and multifractal nature of the process. FTIR revealed surface changes in the adsorbent material attributable to the interactions between the seed and the TA. Extent of vibrations associated with carboxyl groups decreased after adsorption, which was attributed to low-energy interactions, such as π-π stacking, supporting physisorption interaction. The ki values increased linearly with temperature and TA concentration. This study used ideal adsorption systems to elucidate fundamental mechanisms, providing a foundation for future, more complex research. Nance seeds proved to be effective yet underutilized adsorbent material. Further studies are needed on its applicability in continuous processes and multicomponent matrices systems. Full article

The western desert of Iraq is one of the most water-stressed environments in the Middle East. Characterized by unpredictable rainfall and long periods of evaporation. Several small earth dams have been constructed in this region, which are the only available surface water source. This makes the reliability of these structures extremely important. Four small dams, Al-Rutbah, Al-Ubiliah, Horan 2, and Horan 3, are evaluated concurrently across five dry seasons (2016, 2018–2021), a design chosen to separate each dam’s own structural characteristics from the shared regional climate. Surface area was extracted from Landsat 8 imagery for 2019 and 2020 and from the JRC Global Surface Water dataset for 2016, 2018, and 2021, then converted to storage volume and used to build a seasonal water balance around evaporation and infiltration losses; a volumetric adequacy index and a composite drought vulnerability index were derived from this balance. Al-Rutbah’s mean adequacy reached the marginal band (0.488), with a mean vulnerability score at the high-risk threshold (0.501). Al-Ubiliah, Horan 2, and Horan 3 remained unreliable by the adequacy index (0.294, 0.154, and 0.256, respectively) and high-risk by the vulnerability index. Al-Rutbah’s greater design capacity provided a partial buffer against the deficits observed at the smaller dams. Full article

Background/Objectives: Immune checkpoint inhibitor-related hepatitis (ICI-H) can resemble classical autoimmune hepatitis (AIH), but comparative multidomain data remain limited. We compared their clinical, biochemical, and serological profiles and descriptively summarized histopathological findings. Methods: This single-centre retrospective cohort screened 100 records from January 2018 to October 2023; 79 patients met predefined criteria (40 ICI-H; 39 AIH). ICI-H required an updated RUCAM score of ≥6, whereas AIH required a simplified AIH score of ≥6 and compatible histology. Continuous and categorical variables were assessed using Mann–Whitney U and Fisher’s exact tests with Benjamini–Hochberg correction where applicable; histopathological findings were summarized descriptively because biopsy ascertainment was markedly unequal between groups. Results: Compared with AIH, ICI-H occurred more often in men (65.0% vs. 20.5%) and showed higher AST, ALT, ALP, GGT, INR, CRP, and neutrophil-to-lymphocyte ratio (all q < 0.001), but lower ANA positivity (12.5% vs. 74.4%; q < 0.001). Histopathological observations were limited to the biopsy-assessed subgroup (10 ICI-H; 39 AIH) and are reported descriptively because biopsy ascertainment was markedly unequal and non-random. Conclusions: ICI-H and classical AIH showed different observed clinical, biochemical, and serological profiles; however, these differences should not be interpreted as independent diagnostic discriminators because disease-specific criteria contributed to group assignment. Diagnosis after ICI exposure should integrate exposure timing, exclusion of competing causes, structured causality assessment, serology, and selective histology. Outcome comparisons require standardized longitudinal follow-up. Full article

Renewable power plants with co-located battery energy storage systems (BESSs) coordinate forecast-deviation control, renewable-surplus management, electricity-price arbitrage, and ancillary-service commitments through the shared power and energy capability of the battery. This study develops a layered framework for scenario-based intraday multi-service co-optimization and grid-value assessment. The plant-level mixed-integer linear programming (MILP) model operates at 15 min resolution and represents piecewise deviation penalties, time-varying export limits, battery dynamics, a terminal state-of-charge condition, throughput-based degradation costs, and the opportunity cost of reserving regulation headroom. Its scenario-contingent formulation evaluates expected intraday operating value across ten representative photovoltaic trajectories under a perfect-information structure. A complementary service map assigns fast dynamic and system-level indicators to the control, power-flow, and dispatch models appropriate to their time scales. The numerical study considers an 80 MW photovoltaic plant with a 10 MW/20 MWh BESS, evaluates four regulation-compensation cases, and records a complete C4 run time of 209.421893 s on an Intel Core i7-10710U computer with 16 GB RAM. Energy-oriented service stacking increases expected daily plant benefit in the case study, while regulation reservation becomes attractive when compensation exceeds the opportunity cost of battery power and energy headroom. The framework provides a consistent basis for interpreting service interactions, decision timing, data provenance, and plant- and system-level value. Full article

A-type mold flow analyses were performed to examine the effects of the feedstock flow behavior on the powder particle distribution in the weld zone following the forward collision of two flow fronts during metal powder injection molding. Although the A-type mold cavity and the two converging feedstock flow paths are geometrically symmetric about the central weld plane, the present numerical results indicate that the coupled shear-heating and viscosity variation during flow-front collision break this symmetry, resulting in an asymmetric powder concentration and temperature field at the weld zone. This local departure from mirror symmetry was quantified using a proposed Mirror Asymmetry Index (MAI). The complex rheological characteristics of the weld zone result in a separation of the particles and the binder, which leads to changes in the powder concentration distribution. Such predicted concentration non-uniformity may be relevant to local density variation after de-binding and sintering; however, the present study does not simulate sintering or experimentally measure density or mechanical properties. Thus, to enhance the powder concentration in the weld zone and ensure a uniform distribution of the particles, mold flow analysis simulations, combined with the Taguchi experimental method, were performed to identify the optimal material and processing parameters for the metal powder injection molding process. The results indicate that regions of the weld zone with higher shear rates exhibit lower powder concentrations. In addition, local stagnation occurs at the intersection of the two flow fronts, which causes radial flow and phase-separation effects in the weld zone. Among the four factors examined (melt temperature, mold temperature, particle diameter, and injection flow rate), particle diameter was found to exert the dominant effect on weld-plane powder concentration, while the injection flow rate had the least influence. The optimal material and processing conditions (a melt temperature of 220 °C, a mold temperature of 60 °C, a particle diameter of 5 micron, and a filling rate of 10 cm³/s) improved the powder concentration in the weld zone and achieved a more uniform distribution, raising the mean particle concentration by 63.3% and reducing its standard deviation by 74.2% relative to the default settings. These findings show that geometric symmetry alone does not necessarily guarantee perfectly mirror-symmetric predicted process fields under the numerical assumptions used here. Physical confirmation of the predicted asymmetry remains necessary. Full article

Background/Objectives: Modifiable lifestyle factors are established determinants of venous thromboembolism risk, but their relationship with the severity and early course of acute pulmonary embolism (PE) is poorly characterized, and no validated Romanian-language instrument captures these domains in the acute PE setting. This protocol describes a prospective observational study with two distinct components: (i) a measurement component that develops and validates the Pulmonary Embolism Lifestyle and Nutrition Questionnaire (PE-LNQ), a composite patient-completed instrument, and (ii) a clinical component that analyzes the associations between lifestyle factors, routine clinical and laboratory data, and the severity and early outcomes of acute PE. Methods: Phase 1 comprises cross-cultural adaptation, content validation, piloting, and COSMIN-based psychometric evaluation. Its primary endpoints are test–retest reliability (ICC ≥ 0.70) and confirmation of ≥ 75% of a priori construct-validity hypotheses, including convergent validity against measured anthropometry and routine biomarkers. Phase 2 enrolls consecutive adults with CTPA-confirmed acute PE in a staged design (minimum 220 patients single-center; approximately 400 with a planned multicenter extension). The primary clinical endpoint is intermediate-/high-risk PE (vs. low risk) by sPESI/PESI, with the ordinal PESI class (I–V) as the key secondary endpoint. Severity data and a pre-specified panel of routine admission laboratory parameters are extracted from the medical record without study-specific sampling; patients are followed for in-hospital, 3-, and 6-month adverse events. The confirmatory analysis is multivariable logistic regression; ordinal, survival, incremental-value, and biomarker analyses are pre-specified as secondary or exploratory. Expected Results: The PE-LNQ is expected to show adequate reliability and validity, and less favorable lifestyle profiles to be associated with higher severity class and more early adverse events. Conclusions: This study will deliver a validated, freely reusable instrument and clarify the prognostic relevance of modifiable lifestyle factors, supporting their integration into risk assessment and secondary prevention. Full article

Laser-induced graphene (LIG) is a promising porous carbon electrode for flexible microsupercapacitors (MSCs), and defocusing is an established means of tuning its morphology. Here, a defocusing series was evaluated as a complete process-to-device chain with the CO₂ laser power and scan speed fixed at 5.0 W and 46 mm s⁻¹. A polyimide substrate was positioned 0–3 mm below the focal plane to produce laser-induced graphene fibers (LIGFs), LIG-1, LIG-2, and LIG-3. Increasing the defocusing distance lowered the peak fluence per pulse from 16.7 to 2.1 J cm⁻², transforming a fibrous network into porous LIG, an open-cell-like network, and a film whose smooth, oxygen-rich surface skin covered a porous interior. LIG-2 showed the lowest sheet resistance (15.3 Ω sq⁻¹), I_D/I_G ratio (0.29), and equivalent series resistance (78 Ω), delivering 2.88 mF cm⁻² at 0.05 mA cm⁻² and 97.4% retention after 2000 cycles. LIGF showed the lowest contact angle (12.1°), retained 57.3% of its capacitance at 0.25 mA cm⁻², and surpassed LIG-2 at ≥0.10 mA cm⁻². Both electrodes retained their cyclic voltammetry (CV) response under a single 180° bend. Thus, substrate-height adjustment tunes LIG morphology and rate-dependent MSC performance without changing laser power or scan speed. Full article

Employee happiness is increasingly recognized as a core condition underpinning sustainable human resource management in organizations, yet existing measurement instruments have a limitation in that they do not sufficiently reflect the workplace context. Building on a workplace happiness conceptual model (four dimensions—work, relationship, system, and culture—comprising 11 sub-factors) that was separately established through a literature review and expert Delphi surveys, this study aimed to develop and validate an inventory capable of measuring this construct in practice. From an initial pool of 125 preliminary items, two rounds of expert Delphi surveys refined the item set to 91 items, and a pilot survey of 122 respondents narrowed this further to 87 items. A main survey was then conducted with 580 corporate employees, and exploratory and confirmatory factor analyses yielded a final inventory of 85 items comprising four dimensions and 11 sub-factors (model fit: RMSEA = 0.048, CFI = 0.888). Overall reliability was very high (Cronbach’s α = 0.982), and criterion validity—assessed through correlations with existing happiness-related scales—was also confirmed to be adequate (r = 0.675–0.897, p < 0.01). Unlike existing instruments largely adapted from Western scales, this inventory incorporates system- and culture-level dimensions specific to the Korean corporate workplace context and complements existing K-ESG Social-area disclosure indicators, which do not capture employees’ psychological experience of institutional conditions. This inventory offers a valid tool for systematically diagnosing employees’ workplace happiness and can serve as evidence to support sustainable human resource management interventions. Full article

Background: Anti-Müllerian hormone (AMH) is a key biomarker of ovarian reserve, reflecting the quantity of the remaining follicular pool. While chronological age is the primary determinant of AMH concentrations, emerging evidence suggests that vitamin D, vitamin B12, folate, and iron metabolism parameters may also influence ovarian function through mechanisms involving steroidogenesis, DNA synthesis, and oxidative stress regulation. However, clinical findings regarding these associations remain inconsistent. Objective: The aim of this study was to evaluate the relationships between serum AMH concentrations and biomarkers of vitamin D status, vitamin B12, folate, ferritin, and lipid profile in women of reproductive age, and to compare the strength of these associations with that of chronological age. Methods: This retrospective, observational, cross-sectional study included 264 women who underwent AMH testing at Atlas University Hospital. Demographic and laboratory data including AMH, age, vitamin D, vitamin B12, folic acid, ferritin, and lipid parameters were extracted from electronic medical records. Bivariate correlations were assessed using Pearson’s and Spearman’s coefficients on both untransformed and Box–Cox power-transformed data, and were repeated as first-order partial correlations conditioning on chronological age. Statistical significance was set at p < 0.05. Results: The mean age was 34.61 ± 5.75 years, and median AMH was 0.96 ng/mL (Q1–Q3: 0.34–2.34). Age showed a moderate-to-strong, significant inverse correlation with AMH (Pearson’s r = −0.508, Spearman’s rho = −0.547; p < 0.001), and the linear component of this association strengthened after Box–Cox transformation (Pearson’s r = −0.553; p < 0.001). In contrast, vitamin D, vitamin B12, folic acid, ferritin, and lipid parameters (triglycerides, HDL, LDL, total cholesterol) showed no statistically significant and no clinically meaningful correlation with AMH, with all coefficients remaining below 0.20 regardless of transformation (all p > 0.05). After adjustment for age, every coefficient attenuated further towards the null (all |r_partial| < 0.10; all p ≥ 0.127), the largest being that of 25-hydroxyvitamin D (r_partial = 0.094, 95% CI −0.027 to 0.213). A sensitivity power analysis confirmed 80% power to detect an age-adjusted partial correlation of |r| = 0.172 and 91% power at |r| = 0.200. Conclusions: Age remains the principal determinant of ovarian reserve, while vitamin D, vitamin B12, folic acid, ferritin, and lipid parameters show no statistically significant or clinically meaningful association with AMH. These findings suggest that any biological influence of these micronutrients on ovarian reserve, if present, is markedly overshadowed by age-dependent follicular decline. Prospective studies incorporating longitudinal AMH measurements and standardized nutritional assessment are needed to further clarify these relationships. Full article

Background: In the 1960s and 1970s, several authors reported that manipulation of diet by excluding certain additives and natural chemical substances led to apparent clinical benefit for patients with adverse food reactions involving the skin, gastrointestinal tract, respiratory tract, and central nervous system. Methods: Over the past 48 years, patients of all ages presenting to the Royal Prince Alfred Hospital Allergy Unit with adverse food reactions were offered an elimination diet low in natural salicylates, biogenic amines, and glutamate, and free of additives such as preservatives and colors, for two to six weeks. Those who became asymptomatic were offered testing with a “N-of-1” double-blind, placebo-controlled (DBPC) challenge protocol. Results: There were 14,119 patients who elected to undertake either the strict elimination diet (10,074) (71.4%), the moderate approach (2760) (19.5%), or the simple approach (1285) (9.1%). Of these, 6645 (47.1%) became asymptomatic within two to six weeks; 628 (4.4%) reported no improvement; and 6846 (48.5%) were lost to follow-up. Of those who improved, 4963 (35.2%) returned for interpretation of their challenges, and 2429 had undertaken open food challenges; 3326 had completed the DBPC capsule challenge protocol, and 1830 completed both DBPC capsule and food challenges. Although individual reactivity was idiosyncratic, a highly reproducible pattern was evident across the entire group. The proportion reacting to each of the active chemical challenges versus placebo was highly significant (p < 0.001). Conclusions: In many patients with food intolerance, idiosyncratic dietary triggers can be reliably identified with a standardized elimination diet and DBPC challenge protocol. Long-term symptom control can be achieved by appropriate dietary modification. Full article

This paper investigates the controllability and observability of fractional-order dynamical systems on time scales by developing a unified analytical framework based on the Caputo fractional nabla derivative, thereby avoiding separate treatments of continuous and discrete systems. For linear dynamical systems, necessary and sufficient criteria are established through controllability and observability Gramians, together with algebraic rank conditions. Counterexamples demonstrate that the classical full-rank conditions are not sufficient to guarantee controllability and observability on arbitrary time scales. For nonlinear systems, sufficient conditions of controllability and observability are derived using Schauder’s and Banach’s fixed-point theorems. Numerical examples on continuous, uniform discrete, and nonuniform time scales illustrate the applicability and generality of the proposed framework, with potential applications in networked dynamical systems evolving over diverse time scales. Full article

Jobs–housing balance is an important goal of urban sustainable development, and Transit-Oriented Development (TOD) is widely regarded as an effective pathway to optimize the jobs–housing relationship. However, station-area-scale jobs–housing studies remain limited, and existing jobs–housing typologies have not been linked to regulable TOD characteristics, leaving jobs–housing optimization without a basis for differentiated regulation. Using 72 built subway station areas in Shenzhen’s Density Zone 1 as samples, this study draws on three dimensions, namely transport supply (Node), land use (Place), and jobs–housing, and applies hierarchical clustering, multiple linear regression, and Lasso regression to examine jobs–housing typologies, land use and building distribution characteristics, and the effects of transport supply and land use on the jobs–housing relationship in TOD station areas. Regression analysis uses jobs–housing value, a weighted score derived from the employment–residential area ratio (JH1) and the employment–residential population ratio (JH2), as the dependent variable. The main findings are as follows. (1) TOD station areas can be classified into four types, which differ significantly in land use and building distribution; planning strategies should therefore be differentiated according to the characteristics of each type. (2) The four types exhibit a concentric spatial structure comprising an employment-oriented core, a jobs–housing balanced middle ring, and a residential-oriented periphery, with the mean betweenness centrality increasing gradually, indicating that TOD intensity rises in tandem with subway network hub status. (3) Across the full sample, the interaction term between transport supply and land use is significantly and positively associated with jobs–housing value, a result supported by spatial econometric robustness checks; the main effects of Node and Place are significantly negative only in ordinary least squares. (4) Subway line direction, bus stop density, floor area ratio, and maximum planned floor area ratio are positively associated with jobs–housing value, whereas shared bike density, POI density, total road length, and building mixing entropy are negatively associated with it. This study provides a quantitative basis and actionable planning pathways for the differentiated regulation of the jobs–housing relationship in TOD station areas. Full article