Search Results (2,009)

Background/Objectives: Brain death determination in children is clinically challenging. When standard clinical examination cannot be completed or reliably interpreted, ancillary testing is required—yet many established methods depend on infrastructure or patient transport that may not be feasible in critically ill pediatric patients. Orbital ultrasonography is bedside-applicable and non-invasive, but remains poorly characterized in children. Methods: We conducted a single-center retrospective study of 28 pediatric patients evaluated for suspected brain death between January 2021 and February 2025. Patients were classified as brain death-positive [BD(+), n = 20] or brain death-negative [BD(−), n = 8] based on clinical criteria independent of imaging findings. Orbital color Doppler parameters (ophthalmic artery, central retinal artery, posterior ciliary artery) and optic nerve sheath diameter (ONSD) were measured under a standardized protocol by a single experienced operator. Ophthalmic artery resistive index (OA-RI) was defined a priori as the primary outcome; ONSD was the secondary outcome. Group comparisons used the Mann–Whitney U test with Cliff’s delta effect sizes; false discovery rate correction was applied to secondary and exploratory comparisons. ROC analyses were performed to assess discriminative performance. The study was reported in accordance with the STARD 2015 guidelines for diagnostic accuracy research. Results: OA-RI was markedly higher in BD(+) patients (0.84 [IQR 0.80–0.90] vs. 0.65 [0.58–0.69]; p < 0.001; δ = 0.975). ROC analysis yielded an AUC of 0.99 (95% CI: 0.96–1.00); at a cut-off of ≥0.77, sensitivity was 95.0% and specificity 100.0%. ONSD also differed significantly between groups (4.75 [4.15–5.08] mm vs. 3.90 [3.40–4.15] mm; p = 0.012; δ = 0.619; AUC = 0.81, 95% CI: 0.62–1.00; cut-off ≥ 4.2 mm; sensitivity and specificity both 75.0%). Across all three orbital vessels, end-diastolic velocity was consistently reduced and resistive indices elevated in BD(+) patients. Systolic velocities did not differ meaningfully between groups. Cut-off values represent cohort-specific statistical optima and should be interpreted as exploratory. Conclusions: Orbital Doppler ultrasonography demonstrates a coherent high-resistance hemodynamic pattern in pediatric brain death. OA-RI showed strong discriminative performance and may serve as a useful bedside adjunct in selected cases where ancillary testing is indicated. ONSD provides complementary anatomical evidence. These findings are exploratory and require prospective validation in larger, multicenter pediatric cohorts. Full article

Tool wear remains a critical limiting factor in machining performance, particularly in dry cutting conditions where friction and tribological interactions dominate. This study investigates the influence of a 5–8 μm PVD-deposited TiN coating on the wear behavior of high-speed steel (HSS) end mills during milling of three representative wood species (oak, beech, and fir). A spatially resolved wear evaluation methodology was employed, based on ten measurement points distributed along a 20 mm active cutting edge, enabling simultaneous assessment of mean wear and maximum localized wear (Umax). A factorial experimental design combining material type and feed rate (1500–2500 mm/min) was analyzed using two-way ANOVA with effect size quantification (η²). The results reveal a statistically significant reduction in mean wear for TiN-coated tools (F = 7.46, p = 0.0195, η² = 0.34), corresponding to an average decrease of approximately 46% compared to uncoated tools. Maximum wear was influenced by both coating (F = 14.73, p = 0.0028, η² = 0.399) and material (F = 4.37, p = 0.040, η² = 0.237). The experimental findings are interpreted through a tribological framework, indicating a transition from abrasion- and micro-chipping-dominated degradation in uncoated tools to a controlled wear regime in TiN-coated tools, characterized by reduced asperity penetration, delayed crack initiation, and limited tribochemical interactions. These results demonstrate that coating effects dominate global wear evolution, while material properties influence localized degradation. The proposed combined experimental–statistical–mechanistic approach provides a robust framework for understanding and optimizing tool performance in dry machining environments. Full article

Background: Triple-negative breast cancer (TNBC) is associated with poor prognosis, highlighting the need for innovative therapeutic strategies. Chronomodulated chemotherapy yielded improved efficacy and tolerability in several malignancies; however, evidence in breast cancer remains limited. This study investigated the association between the time of day of administration (ToDA) of neoadjuvant chemotherapy (NAC) and clinical outcomes in patients with TNBC treated in a day hospital setting. Methods: This retrospective cohort included patients treated at Saint-Louis Hospital with neoadjuvant dose-dense, dose-intense cyclophosphamide–epirubicin followed by weekly paclitaxel. Infusion start times of each chemotherapy agent were systematically recorded. The primary endpoint was pathological complete response (pCR; Residual Cancer Burden [RCB] = 0). Secondary endpoints included RCB classes, early metabolic response, treatment tolerance, and 36-month event-free survival (EFS). Patients were classified into early or late infusion groups using multiple ToDA cut-offs, and cosine-based analyses were performed. Results: Ninety-four patients (median age 51 years) received NAC between 9:00 and 17:40 which aligns with the day hospital unit’s opening hours. With a median follow-up of 39.9 months, the pCR rate was 48.9%. No significant differences were observed between early and late infusion groups for any endpoint, regardless of ToDA cut-off or analytical approach. Conclusions: This first chronotherapeutic study in patients with early TNBC showed no association between ToDA of NAC administered between 9:00 and 17:40 and histological response or EFS. Although limited by sample size and the restricted infusion time window, our study provides novel data and methodological insights supporting further investigation of chronotherapy in patients with breast cancer. Full article

Overcoming the inherent permeability–selectivity trade−off is essential to broaden the practical application of polyamide (PA) reverse osmosis (RO) membranes in brackish water desalination. In this study, we developed a facile and cost-effective alkaline (NaOH) post-treatment method to fabricate high−performance loose-structured RO membranes. The NaOH post−treatment hydrolyzed part of the amide bonds within the membrane, converting them to negatively charged carboxyl groups. This process led to a slight increase in pore size and the formation of a looser structure. Molecular weight cut−off (MWCO) measurements confirmed that the pore size slightly increased from 0.19 nm to 0.21 nm, while X−ray photoelectron spectroscopy (XPS) and zeta potential measurements confirmed the conversion of amide bonds to carboxyl groups, which further enhanced the surface electronegativity. The synergistic effects of pore size enlargement and surface charge modification were elucidated as the key mechanisms for performance enhancement. The TPA membrane exhibited a 2−fold increase in water permeance (from 1.05 to 3.21 L m⁻² h⁻¹ bar⁻¹), while the enhanced surface negative charge contributed to maintaining a high NaCl rejection of 98.5%. Additionally, the membrane also exhibited excellent pH stability as well as long-term stability over 100 h of continuous operation. This easily scalable post−treatment strategy offers a low−cost route to fabricate loose-structured membranes, with significant potential to enhance efficiency and reduce costs in brackish water desalination. Full article

In response to the pressing need for miniaturized MEMS microphones in wearable technology and mobile devices, and to surmount the technical limitations inherent in conventional piezoelectric microphones, which typically depend on enlarging chip dimensions or decreasing stiffness to attain low resonance frequencies, this study introduces a novel piezoelectric MEMS microphone (PMM) design predicated on a flexibility-enhanced rotating structure. The proposed design utilizes an aluminum scandium nitride (Al_0.8Sc_0.2N) piezoelectric thin film with 20% scandium doping and incorporates four equivalent sensing units formed by four curved cutting lines centrally located on the chip. This configuration employs a nested arrangement of four cantilever beams to substantially increase vibration compliance, thereby effectively lowering the natural frequency without altering the chip’s external size. Three-dimensional finite element simulations reveal that, relative to traditional triangular cantilever beam architectures, the flexibility-enhanced rotating structure reduces the natural frequency from 15.6 kHz to 13.49 kHz while enhancing sensitivity from −44.6 dB to −40 dB. The device was fabricated via a comprehensive microfabrication process and subsequently characterized within a standardized acoustic testing environment. Experimental results indicate that the microphone attains a sensitivity of −43.84 dB at 1 kHz and exhibits a first resonance frequency of 13.5 kHz, closely aligning with simulation predictions. Furthermore, the signal-to-noise ratio (SNR) reaches 58.3 dB across the full range of human-audible frequencies. By leveraging the flexibility-enhanced rotating structure, this work achieves an optimal compromise between elevated sensitivity and reduced resonance frequency within a compact form factor, thereby offering a viable technical solution for the advancement of high-performance miniature acoustic sensors. Full article

Since the features of cross-seeding of alpha-synuclein forms may affect the sensitivity and specificity of the test systems, we developed a modified approach to obtain alpha-synuclein amyloid seeds with particle sizes from 20 to 50 nm prepared from either the wild-type protein (α-synWT) or its more fibrillation-prone form A53T (α-synA53T). These seeds had optimal properties for subsequent initiation of fibrillation. Our data showed that the elevated efficiency of alpha-synuclein A53T monomer transformation was hardly affected by the type of used seeds, whereas the addition of the seeds obtained from the alpha-synuclein mutant form to wild-type protein monomers had a significantly smaller effect than α-synWT seeds. Transmission electron microscopy data revealed that in the presence of α-synWT seeds the wild-type alpha-synuclein formed long and wide fibrils, while the addition of α-synA53T seeds led to the formation of long, but thin fibrils. Since the lag period of α-synA53T monomer fibrillation was significantly reduced compared to the wild-type protein, the replacing of α-synWT with α-synA53T in current assay systems designed to detect aberrant forms of α-synuclein in biological fluid samples (e.g., RT-QuIC) could substantially cut the time of analysis. In the future, a set of alpha-synuclein mutant forms could be used for the differential diagnosis of synucleinopathies caused by the different mutations of this protein. Full article

To address the issues of high cutting temperatures and severe tool wear during titanium alloy machining, this study proposes a hybrid surface modification strategy combining micro-textures and multicomponent titanium nitride (TiN)-based coatings on cemented carbide tools. Using YG8 cemented carbide as the substrate, micro-dimple textures were fabricated by fiber laser, and three coatings with different architectures (TiAlSiN, TiSiN/TiAlN, and TiSiN/TiAlSiN/TiAlN) were deposited via multi-arc ion plating technology. Based on a two-factor (texture diameter and texture spacing) and three-level orthogonal experiment, the evolution behaviors of surface morphology, phase composition, and mechanical properties of the textured multicomponent TiN-based coatings were systematically characterized and comparatively analyzed. The results reveal that: compared to the monolithic-structured TiAlSiN coating, the TiSiN/TiAlSiN/TiAlN and TiSiN/TiAlN composite coatings with multilayered composite structures can effectively relieve the residual stress inside the film–substrate system, and significantly suppress the phenomena of coating cracking and localized spallation caused by irregular protrusions of the recast layer at the micro-texture edges. X-ray diffraction (XRD) and crystallite size analyses indicate that the amorphous Si₃N₄ phase promoted by the Si element in the composite coatings effectively impedes the growth of TiN columnar crystals, achieving significant grain refinement. Mechanical property tests confirm that the existence of multicomponent composite interfaces effectively hinders dislocation movement. Among them, the textured TiSiN/TiAlSiN/TiAlN composite coating exhibits the optimal comprehensive performance; its microhardness, nanohardness, and H/E ratio (characterizing the resistance to plastic deformation) are increased by 17.94%, 8%, and approximately 45%, respectively, compared to those of the textured TiAlSiN coating. This study deeply elucidates the synergistic strengthening and toughening mechanisms between micro-texture parameters and the internal structures of the coatings, providing important theoretical guidance and experimental data support for the surface design of long-lifespan tools oriented towards the high-efficiency machining of titanium alloys. Full article

This paper presents the design of a compact four-element MIMO antenna based on a metamaterial structure and a reactive load generated by an open-circuit stub. The radiator array, arranged in an axial symmetry configuration, provides high inter-element isolation despite a sub-millimeter separation. The design is optimized for 5G n77/n78 band applications and employs a metamaterial structure composed of embedded octagonal split-ring resonators (SRRs) integrated on a Duroid RT5880 0500 (${ϵ}_r=2.2,h=1.27 \mathrm{m}\mathrm{m}$) substrate. This configuration achieves high miniaturization, with individual radiators of $19\times 9.53 \mathrm{m}{\mathrm{m}}^2$. Furthermore, through a stub-loading technique, the array is enhanced in two significant aspects: (a) it exhibits an increased impedance bandwidth, rising from a 23% fractional bandwidth in the stub-less design to 39% in the final architecture; and (b) a shift of the lower cut-off frequency toward lower values is obtained, resulting in a reduction of the radiator’s electrical length, which translates into physical size diminution. The total array has a size of only $28.8\times 28.8 \mathrm{m}{\mathrm{m}}^2$ ($0.24{\lambda }_0\times 0.24{\lambda }_0$, considering the lower cut-off frequency). Despite the proximity between radiators and the absence of electromagnetic decoupling structures, the design ensures inter-element isolation exceeding 15 dB in the lower band and reaching values above 20 dB in the mid and upper bands. Diversity metric analysis confirms high performance, yielding an Envelope Correlation Coefficient (ECC) $\ll 0.005$, Diversity Gain (DG) close to the ideal value ($\ge 9.9$), Total Active Reflection Coefficient (TARC) below −10 dB (converging in random phase analysis), and a Channel Capacity Loss (CCL) of less than $0.4$ bits/s/Hz. Therefore, the proposed antenna stands as an ideal design for compact 5G communication devices. Full article

Background and Objectives: Acute exacerbation of COPD (AECOPD) poses a major burden on healthcare systems, with critically ill AECOPD patients having increased morbidity and mortality. Since adverse outcomes are due both to respiratory failure and the systemic inflammatory response, prognostic markers accounting for these patterns are needed. Our aim was to investigate the predictive power of derived hematological indices for intensive care unit (ICU) mortality in patients with non-infectious versus infectious AECOPD. Materials and Methods: This is a retrospective, observational, monocentric cohort study on 88 AECOPD patients admitted to the ICU between 2018 and 2023. Descriptive statistics were performed for the entire cohort, and for predefined subgroups (non-infectious, infectious and bacterial AECOPD). Receiver Operating Characteristics (ROC) analysis was performed to test the predictive power of the studied indices. Cut-off values were identified using the Youden index. Kaplan–Meier analysis was conducted to test the association with ICU mortality. Results: Overall ICU mortality was 44%. For the whole cohort, neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-platelets ratio (NPR) and systemic inflammation response index (SIRI) showed moderate predictive power for ICU mortality (areas under the curve (AUCs) of 0.71–0.73). Non-infectious and infectious subgroups were comparable in terms of size, demographics, comorbidities and baseline COPD characteristics (p > 0.05). Mortality was significantly higher in infectious AECOPD (64.6% versus 20%, p < 0.001). For non-infectious AECOPD, monocyte-to-lymphocyte ratio (MLR) and SIRI had very good predictive power (AUCs between 0.82 and 0.855), while NPR and systemic inflammation index (SII) showed moderate AUC values (between 0.7 and 0.79). In infectious AECOPD, only NPR retained fair predictive power (AUC 0.691), which improved in bacterial AECOPD (AUC 0.781). Conclusions: Derived hematological indices have different predictive values for ICU mortality. MLR and SIRI exhibited very good predictive power in non-infectious AECOPD, while NPR was the best discriminator in bacterial AECOPD. These stress the importance of individualized prognostication in AECOPD. Full article

People spend most of their time indoors, highlighting the importance of indoor environmental quality for health and wellbeing. While previous studies have shown that exposure to nature can benefit wellbeing, much of this research has focused on outdoor environments, and less is known about how indoor plants and their spatial characteristics influence human perceptions and experiences. This paper reports on a survey study exploring how perceived health and wellbeing are influenced by indoor plants and human preferences for their characteristics, spatial arrangement, and other features within indoor environments. Indoor plants serve as visual and multisensory environmental stimuli. By examining the relationship between indoor plants, preferences, perceptions, visual comfort, multisensory experiences, and wellbeing, the study aims to understand these influences. The questionnaires include multiple-choice questions, yes-no questions, and open-ended questions, allowing the collection of both quantitative and qualitative data. The survey findings highlight the unique benefits of indoor plants, emphasising their potential to enhance wellbeing in ways that outdoor nature may not fully replicate in indoor settings. One significant finding of this study is that scattering indoor plants throughout a space can enhance the connection to nature through three-dimensional spatial interaction, potentially improving wellbeing. This arrangement may serve as a bridge to the outdoors, providing a psychological link to the natural environment. Crucial preference factors also include the complexity and coherence of indoor plants’ appearance, such as colour, shape, and size. The results further indicate that students prefer indoor plants over other elements such as cut flowers, fake plants, or artificial plant representations. The findings indicate that caring for indoor plants may foster emotional engagement, a sense of fulfilment, and place attachment through everyday interaction. In public spaces, plants may also enhance feelings of refuge and perceived security. These findings provide practical recommendations for designing indoor environments that enhance student wellbeing and human–environment interaction. Full article

Background: Inflammation is central to myocardial injury and repair after ST-segment elevation myocardial infarction (STEMI). C-reactive protein (CRP) is an established biomarker of systemic inflammation, but its prognostic thresholds across patient subgroups are not well defined. Methods: In this retrospective cohort study, admission CRP was analyzed in 958 consecutive STEMI patients admitted to University Hospital Salzburg 2018–2020 and categorized into four groups (Serum CRP < 5.0, 5.0–9.9, 10.0–15, and >15.0 mg/dL). Mortality was assessed during short- (30, 90, and 180 days) and long-term (1, 3, and 5 years) follow-up. Kaplan–Meier analyses compared survival, Cox regression tested associations, and receiver operating characteristic (ROC) curves determined discriminatory value and optimal cut-offs. Results: Elevated admission CRP was associated with larger infarct size, impaired left ventricular function, and increased mortality. Kaplan–Meier curves showed progressively poorer survival with higher CRP, with worst outcomes at >15 mg/dL. At 30, 90, and 180 days, CRP demonstrated moderate discrimination (AUC 0.628, 0.653, and 0.654; all p < 0.001), with predictive cut-offs 11–15 mg/dL in the overall cohort. Subgroup analyses revealed markedly lower thresholds in vulnerable populations. Diabetic patients showed cut-offs 5–6 mg/dL with the highest AUC values (up to 0.714). Younger patients and smokers exhibited thresholds near 9–10 mg/dL, while subacute STEMI presentations demonstrated lower cut-offs compared with acute infarction. These findings indicate that the prognostic value of CRP is context-dependent rather than uniform. Conclusions: Admission CRP predicts short-term mortality after STEMI, with subgroup-specific cut-offs emerging below conventional thresholds, highlighting profiles where modest inflammatory activation carries disproportionate risk. Full article

Background: Early risk assessment in non-variceal upper gastrointestinal bleeding (NVUGIB) is essential for guiding clinical management. The neutrophil percentage-to-albumin ratio (NPAR) has recently been proposed as a marker reflecting both inflammatory response and physiological reserve. This study aimed to evaluate the prognostic value of NPAR for in-hospital mortality and its relationship with established risk scores in patients with NVUGIB. Methods: This retrospective observational study included 94 patients hospitalized with NVUGIB. NPAR was calculated using laboratory parameters obtained at admission. Patients were stratified according to AIMS65 (<2 vs. ≥2) and Rockall (<5 vs. ≥5) scores. In addition, inflammation-based indices, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), were calculated. Predictive performance was evaluated using receiver operating characteristic (ROC) curve analysis, and associations with clinical outcomes were assessed. Results: The in-hospital mortality rate was 12.8%. NPAR values were significantly higher in patients with AIMS65 ≥ 2 and Rockall ≥ 5 (p < 0.001 for both). NPAR demonstrated good discriminative ability for AIMS65 ≥ 2 (AUC: 0.843) and moderate performance for Rockall ≥ 5 (AUC: 0.714). For mortality prediction, NPAR showed excellent performance (AUC: 0.900). A cut-off value of 27.4 yielded a sensitivity of 91.7% and a specificity of 75.6%. Higher NPAR values were associated with increased mortality risk (OR 31.9, 95% CI: 3.88–102.59, p < 0.001), while the negative predictive value was high (98.4%). In contrast, NLR, PLR, and SII showed limited predictive value for in-hospital mortality. Conclusions: NPAR shows promise as a potential prognostic biomarker for assessing disease severity and in-hospital mortality in NVUGIB. Its high negative predictive value and association with established risk scores suggest that it may complement current risk stratification approaches. However, these findings should be considered preliminary, given the retrospective design and limited sample size, and require validation in larger prospective studies. Full article

This article analyzes the scale, fluctuations and geographical distribution of olive (Olea europaea) cultivation in Palestine over 550 years, from the Late Mamluk period (1300–1517), through the Ottoman era (1517–1917), until the end of the British Mandate in 1947. Although olive oil played a dominant role in the diet and the local economy, there is currently no research that measures and quantifies the number of olive trees or the number of villages and towns that cultivated olive trees and produced olive oil. We reconstruct the agricultural landscape with its vast olive groves and examine the cultural history of olive tree farming, the growth of the olive oil industries and their economic role and importance. The earliest figures we have, that are from the year 1596, show that 400 villages cultivated 1,400,794 olive trees. By 1943, there were 6,053,367 olive trees that were cultivated by 644 villages. We found a strong correlation (R² = 0.96, p < 0.01) between the number of olive trees and the number of villages, indicating that olive oil demand and the olive oil industry align with population size. The research data derives from a variety of medieval local chroniclers, as well as diaries by European, North African and Middle Eastern travelers who provide descriptions of olive groves and the olive oil industry. Among the most important sources are the 1596 Ottoman tax registers. The tax registers are the first document that present clear-cut figures on the numbers of olive trees, olive presses and the names of the villages that cultivated olive groves. The main sources for the last period dealt with in this study are the British Mandate maps (1943), which display the acreage of the different crops across Palestine. The data from the maps is supplemented by two modern works on olive cultivation written by agronomists Assaf Goor (b. 1894) and Ali Nasouh (b. 1906) who were born in Palestine and employed by the British department of agriculture. The analysis of data shows that demands of local and oversea markets; the olive oil soap industry, which was based on the local olive oil; as well as competing agricultural crops like sugarcane, cotton and citrus, contributed to a complex economic structure. Olive tree cultivation did not depend on government investment. Olive groves in Palestine were rain fed, and, except for the harvest, they required relatively few working days a year. Hence, moderate policies (low taxation during periods of drought and low yields) adopted by enterprising local rulers and the central British government created a unique and relatively balanced relationship between rulers and farmers, which encouraged olive cultivation and led to a constant increase in the number of olive trees and the development of the olive oil industry. Full article

Background/Objectives: Testicular germ cell tumors, particularly seminoma, represent the leading cause of cancer in men aged 15–40 years. The decision about adjuvant therapy relies on histological features with uncertain prognostic value. The Pituitary-Tumor-Transforming Gene 1 (PTTG1), which encodes the securin protein, is crucial in sister chromatid separation. Our previous in vitro studies demonstrated that PTTG1 nuclear expression promotes invasiveness, dedifferentiation, and neolymphangiogenesis in testicular seminoma. Methods: We conducted a hypothesis-generating retrospective observational study on 51 patients (aged 23–68) with testicular seminoma, with (43%) or without (57%) lymph node involvement, evaluating potential correlations between PTTG1 and currently known prognostic factors. Clinical and pathological data were collected, including lymph node involvement, recurrence, necrosis, rete testis invasion, vascular invasion, and adipose tissue invasion. An immunohistochemical scoring system assessing intranuclear PTTG1 expression was developed. Results: The PTTG1 score was related to lymph node metastasis and adipose tissue invasion. ROC curve analysis showed that the PTTG1 immunohistochemical score showed good discriminatory ability in identifying lymph node involvement (AUC = 0.939); the optimal cut-off was 4.0 (sensitivity 90.5%; specificity 57.1%), while the ROC curve for adipose tissue invasion was inadequate. Lymph node metastasis also correlated with necrosis; however, logistic regression confirmed that PTTG1 score was independently associated with nodal involvement (p = 0.002), regardless of tumor size and necrosis. Conclusions: Our findings suggest a correlation between PTTG1 expression and lymphadenopathy at diagnosis, independent of tumor size and T stage. It may reflect biological features associated with lymphatic dissemination and requires further investigation in larger prospective studies. Full article

As an efficient solid–liquid separation device, the hydrocyclone is widely applied in various industrial fields such as coal preparation and oil impurity removal, and its classification performance directly determines the efficiency of industrial separation operations., As the core separation zone of the hydrocyclone, the cone segment, its structure and the number of cone angles directly affect the flow field distribution characteristics and particle classification performance of the hydrocyclone. To reveal the regulation mechanism of the combined cone angles on the classification performance of hydrocyclones, numerical analysis and experimental verification methods were adopted to investigate the internal flow field and classification performance of hydrocyclones under different cone angle combinations. The evolution laws of velocity field, pressure field, turbulence characteristics, and particle classification effect under different configurations were systematically explored. The results show that the basic characteristics of the core flow field of the hydrocyclone do not change essentially with the increase in the number of cone segments, but the amplitude, distribution, and stability of flow field parameters are significantly regulated. The three-cone configuration achieves the optimal flow field synergy effect: the amplitude of the high turbulence intensity zone is lower and concentrated near the central axis; the zero-velocity envelope surface is stably maintained at approximately 8 mm in the core separation zone; and the full axial fluctuation of the air core is gentle, which effectively inhibits random particle diffusion and flow pattern mixing. In terms of separation performance, the three-cone configuration exhibits the highest classification efficiency in the core range of sub-coarse particles (10~30 μm), with the cut size (approximately 17.5 μm) in a reasonable range, the steepness index reaching a peak value (approximately 0.55), and the pressure drop (approximately 1.8 × 10⁵ Pa) and split ratio (2.8%) achieving synergistic optimization, balancing separation accuracy and energy consumption control. The single-cone configuration causes flow field disturbance due to the one-time contraction of the flow channel, while the four-cone configuration falls into the dilemma of “high pressure drop–marginal performance gain”, and neither achieves optimal performance. The regulation law of the number of cone segments revealed in this study provides a scientific basis for the structural optimization and engineering application of multi-cone hydrocyclones, and is of great significance for improving the particle classification efficiency in fields such as wastewater treatment and mineral processing. Full article