Search Results (5,499)

Background: Temporomandibular disorders (TMDs) are multifactorial conditions frequently encountered in orthodontic practice, and the independent associations of occlusal and structural variables remain unclear. This case–control study constructed a multivariable model integrating clinical, cephalometric, panoramic, and functional variables to examine their associations with TMD, diagnosed according to the DC/TMD Axis I protocol. Fifty patients with TMD and 50 non-TMD controls were consecutively recruited between October 2024 and December 2025. Occlusal characteristics, lateral cephalometric measurements, and Kjellberg panoramic symmetry indices (SI1/SI2) were assessed using standardized protocols. Candidate variables were initially explored using univariable analyses with false discovery rate adjustment, followed by multivariable Firth penalized logistic regression to reduce small-sample bias and separation. Mandibular deflection (OR = 3.57, 95% CI 1.54–9.09) and deviation (OR = 4.35, 95% CI 1.69–12.50) demonstrated the strongest independent associations with TMD, while SI1 asymmetry (<90%) became significant after multivariable adjustment (OR = 3.57, 95% CI 1.08–14.29). The final model showed apparent discrimination within the study sample (AUC = 0.822; 95% CI: 0.742–0.902). However, this value was calculated using the same dataset and should not be interpreted as validated model performance or compared to other studies. The observed SI1 effect should be interpreted cautiously, as it may reflect model instability due to the relatively small sample size. Within the limitations of this case–control design, functional disturbances showed stronger associations with TMD than static structural variables; however, external validation is required before clinical application. Full article

Background/Objectives: Patients with poor sleep are at high risk of developing type II diabetes mellitus (T2DM). Since T2DM is linked to increased risk of obstructive sleep apnea (OSA), and Metformin is commonly used to treat T2DM, we examined how Metformin affects sleep stages in patients with concurrent T2DM and OSA-related symptoms of snoring and fatigue. Patients with T2DM on Metformin progressively develop increased insulin resistance associated with sleep disturbances and poor glycemic control. We therefore explored sleep pattern changes in patients with OSA symptoms and T2DM on Metformin, with a special focus on whether Metformin affects sleep architecture. Methods: Polysomnogram (PSG) data from patients with T2DM on Metformin was evaluated along with data on age, body-mass index (BMI), and biological sex. Data analysis included mean ± standard deviation, t-test with p < 0.05 taken as significant, and linear regression. Results: Patients with a BMI of less than 30 (non-obese) and taking Metformin exhibited a significantly shorter rapid eye movement sleep stage (REM) duration than patients on alternative therapies (p = 0.036). No such difference in REM was found for patients with a BMI of 30 or greater (obese) taking Metformin. While there was also no significant difference in slow-wave sleep stage (N3) duration with Metformin use, linear regression identified a moderate negative correlation between N3 and age in patients taking non-Metformin therapies (R² = 0.4555). No significant correlations between sleep stage duration and patient sex, smoking status, or BMI greater than 30 were identified. Conclusions: Overall, patients with OSA and T2DM on Metformin had lower mean quantities of N3, and REM sleep compared to those not on Metformin. Non-obese patients with T2DM and OSA being treated with Metformin were observed to have less REM sleep, regardless of sex or smoking history. N3 and REM sleep are needed for the timely secretion of growth hormone and memory consolidation. Since Metformin is correlated with differences in N3 and REM sleep, it may contribute to the development of insulin resistance. Future studies are needed to explore potential causes for this relationship and how it may affect the treatment of T2DM. Full article

The gimbal servo system in a control moment gyroscope (CMG) is critical for high-precision spacecraft attitude control, where comprehensive performance testing and evaluation are essential for ensuring spacecraft reliability and service life. Traditional motor testbenches exhibit limitations, whereas the electric motor emulator (EME) based on power electronic converters is a promising alternative for testing extreme operating conditions, such as ultra-low speed operation and fault scenarios. However, existing EME control methods suffer from limited system bandwidth and insufficient emulation accuracy, which limits their applicability. To address these issues, this paper proposes an improved current control strategy for the ultra-low speed permanent magnet synchronous motor (PMSM) emulator. First, a mathematical model of the EME based on the topology of the voltage source converter is established. Then, based on the deadbeat control concept, a deadbeat predictive current control (DPCC) strategy is developed to enhance the dynamic performance. Furthermore, to suppress the parameter mismatch disturbance, an optimization scheme based on a cascaded extended state observer (CESO) is introduced. The first-stage ESO is applied to estimate and compensate for total disturbances, while the second-stage ESO is a supplement to suppress the remaining disturbances in the EME system, which improves the robustness of the DPCC controller. Finally, the effectiveness of the improved emulation accuracy of the proposed method is verified through experiments. Full article

Background: Sleep disturbance and psychosocial stress are emerging contributors to hypertensive disorders of pregnancy. The present cohort was recruited during the COVID-19 period, a time marked by substantial changes in prenatal care delivery, social support, and daily routines, which may have influenced maternal sleep and stress burden. Objective: This study aimed to evaluate the independent and integrated associations between maternal sleep quality, psychological stress, and pregnancy outcomes in women at moderate to high risk for preeclampsia. Methods: In a single-center observational cohort of 170 pregnant women enrolled at 16 weeks’ gestation, sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Fitbit Sense 2™ wearable data, while stress was measured through the Perceived Stress Scale (PSS-10), Generalized Anxiety Disorder-7 (GAD-7), and morning salivary cortisol. Associations with preeclampsia, birth weight, gestational age, and NICU admission were analyzed using multivariate regression and receiver operating characteristic (ROC) models. The COVID-19 period was treated as the contextual background of recruitment rather than as a directly compared exposure. Results: Poorer subjective sleep quality (higher PSQI) correlated negatively with birth weight (r = −0.34, p = 0.008) and gestational age (r = −0.28, p = 0.04). Elevated morning cortisol was significantly associated with NICU admission (r = 0.28, p = 0.002). The combined sleep + stress model predicted birth weight (R² = 0.26, p = 0.003) and preeclampsia (pseudo R² = 0.15, p = 0.015) more accurately than individual domains, achieving an ROC-AUC of 0.86 (95% CI: 0.78–0.92). Conclusions: In high-risk pregnancies, integrated evaluation of sleep and stress parameters may improve the prediction of fetal growth impairment and preeclampsia beyond single-domain models. These findings support the incorporation of psychosocial and behavioral markers into antenatal risk stratification. Because no pre-pandemic or post-pandemic comparator group was included, the COVID-19 period should be interpreted as the contextual background of the study rather than as an independently tested exposure. Full article

Endovascular aneurysm repair (EVAR) is a widely used minimally invasive treatment for abdominal aortic aneurysms. However, postoperative type II endoleak (T2EL) remains a relevant complication associated with a risk of aneurysm rupture and the need for repeated imaging follow-up, resulting in exposure to ionizing radiation. Identification of biological factors predisposing to T2EL may improve risk stratification. This pilot study aimed to investigate whether disturbances in hemostasis are associated with early T2EL development after EVAR. A total of 103 patients treated with EVAR for symptomatic or asymptomatic abdominal aortic aneurysms in a tertiary vascular center were prospectively enrolled. Blood samples were collected preoperatively and one month postoperatively to assess fibrinogen, prothrombin fragment F1+2 (F1+2), thrombin–antithrombin complex (TAT), tissue plasminogen activator antigen (tPA), plasminogen activator inhibitor-1 (PAI-1) activity, and platelet activity. Computed tomography angiography (CTA) during follow-up was used to detect endoleaks and calculate their volume. Patients with T2EL had significantly lower levels of prothrombin fragment F1+2 and higher PAI-1 activity compared with patients without endoleak. No significant association was observed between the analyzed biomarkers and endoleak volume. These findings suggest that reduced thrombin generation and impaired fibrinolysis may contribute to endoleak formation after EVAR and warrant further investigation in larger, confirmatory studies. Full article

Background: Transient ischemic attack (TIA) and minor stroke often result in excellent functional recovery but are frequently followed by substantial psychological morbidity. It remains unclear whether mood disturbances or cognitive impairment are the primary contributors to reduced health-related quality of life (HRQoL) in this population. Methods: We conducted a prospective observational case–control study including 90 patients with acute TIA or minor stroke confirmed by diffusion-weighted imaging and 92 age-matched healthy controls. At 90 days, participants completed the Hamilton Depression Rating Scale, Hamilton Anxiety Rating Scale, Montreal Cognitive Assessment, and the EQ-5D-5L. Hierarchical multiple regression using standardized z-scores identified independent predictors of HRQoL. Bias-corrected bootstrapped mediation analyses (5000 iterations) assessed whether cognitive impairment mediated the relationship between mood symptoms and HRQoL. Results: Compared with controls, patients exhibited markedly higher rates of depressive symptoms (82.2% vs. 18.5%), anxiety symptoms (81.1% vs. 21.7%), and cognitive impairment (66.7% vs. 13.0%) (all p < 0.001). Psychopathological variables explained an additional 36.6% of HRQoL variance, whereas cognitive and neuroimaging variables contributed only 1.7% (ΔR² = 0.017; p = 0.523). In the fully adjusted regression model, HAM-A showed the numerically largest standardized coefficient (β = −0.055; p = 0.064), representing a trend toward significance, while HDRS-17 did not individually reach statistical significance (β = −0.043; p = 0.147); cognitive impairment had negligible independent effects (β = −0.001; p = 0.947). Both mood variables collectively accounted for the substantial majority of explained HRQoL variance, far exceeding the contribution of cognitive and neuroimaging predictors. Mediation analyses revealed no significant indirect effects, indicating that mood and cognitive complications are statistically consistent with a model in which mood and cognitive symptoms exert independent effects on HRQoL; temporal ordering cannot be established from these cross-sectional measures. Conclusions: Following TIA or minor stroke, depressive and anxiety symptoms are highly prevalent, persist despite good neurological recovery, and exert a disproportionately negative impact on HRQoL. Anxiety appears particularly influential in determining patient-reported outcomes. The statistical consistency of the mediation models with parallel rather than sequential mood–cognition pathways suggests that these represent independent neurobiological sequelae requiring separate clinical attention, underscoring the need for routine and concurrent assessment of both mood and cognitive function after TIA and minor stroke. Full article

Chlorinated paraffins (CPs) are widely used, structurally complex mixtures of chlorinated alkanes whose ecological risks in aquatic ecosystems have raised increasing concern. However, the toxic effects and molecular mechanisms of CPs on primary aquatic producers remain poorly understood. In this study, we used the eukaryotic green algae Chlorella sp. and the prokaryotic cyanobacterium Microcystis aeruginosa (M. aeruginosa) as test organisms to systematically investigate the effects of CPs with different carbon chain lengths, namely short-chain CPs (SCCPs), medium-chain CPs (MCCPs), and long-chain CPs (LCCPs), on algal growth, photosynthetic pigment content, antioxidant systems, cellular ultrastructure, and the underlying molecular responses. Our results showed that CPs toxicity to algae is significantly dependent on both CPs carbon-chain length and algal species. Exposure to 1.0 mg/L SCCPs for 96 h produced a growth inhibition of Chlorella sp. of 14.45%. CPs’ exposure significantly altered algal Chl-a content and elicited antioxidant defense responses, and affected the synthesis and extracellular release of MC-RR and MC-LR in M. aeruginosa. Ultrastructural observations revealed cell surface wrinkling and deformation in both Chlorella sp. and M. aeruginosa. Chlorella sp. additionally exhibited thylakoid disintegration and plasmolysis. Transcriptomic analysis indicated that CPs with different chain lengths significantly downregulated genes in Chlorella sp. associated with DNA replication and mismatch repair, suggesting impairment of replication initiation and elongation and compromised genome stability. Concurrently, genes encoding photosynthetic antenna proteins and carbon fixation were upregulated. In M. aeruginosa, CPs exposure markedly disturbed energy metabolism pathways, including glycolysis/gluconeogenesis and oxidative phosphorylation, which were generally downregulated. This study provides a comparative assessment of CPs’ toxicity between the eukaryotic algae Chlorella sp. and the prokaryotic algae M. aeruginosa, revealing that toxicity is co-determined by carbon chain length and algal species. Additionally, it provides critical toxicological data and establishes a theoretical foundation for the scientific assessment of the aquatic ecological risks posed by CPs with different carbon chain lengths. Full article

Cultural and natural heritage are increasingly framed as components of territorial governance rather than isolated conservation elements; yet, a structural gap persists between their strategic recognition in planning documents and their measurable integration into statutory land-use systems that guide spatial decision-making. This gap is particularly pronounced in protected areas, where ecological integrity, cultural and symbolic values, tourism functions, and socio-economic expectations converge within environmentally sensitive landscapes. This study develops and empirically applies a compatibility-based analytical framework that embeds Multi-Criteria Decision Analysis (MCDA) within the statutory spatial planning system of Kozara National Park. The framework combines (i) institutional analysis of legally binding planning instruments, (ii) zoning-aligned analytical units derived from the Special-Purpose Spatial Plan and Management Plan, and (iii) a weighted multi-criteria model incorporating ecological integrity, cultural–historical significance, tourism and recreation capacity under controlled use, and socio-economic feasibility. Climate-related disturbance exposure is incorporated as a planning-relevant modifier of ecological compatibility. Composite compatibility scores under the baseline configuration range from 2.55 to 3.85 across analytical units. Rank correlation analysis suggests a high degree of structural consistency across both alternative weighting configurations relative to the baseline scenario (Spearman’s ρ ≈ 0.90), with only limited rank reordering observed, primarily between the two highest-ranked analytical units. Dispersed low-intensity recreational configurations demonstrate the highest structural robustness, whereas infrastructure-intensive zones exhibit management-dependent compatibility. The findings show how spatial planning in protected areas can operationalize compatibility as a measurable decision-support principle without substituting statutory zoning logic. Full article

Background: Sleep disturbance is a well-recognized contributor to headache burden, yet the specific sleep domains associated with disability may differ between episodic migraine (EM) and episodic cluster headache (ECH). Methods: In this prospective observational study, 20 EM patients, 21 ECH patients, and 18 age-, sex-, and BMI-matched healthy controls (HCs) were evaluated during interictal periods. None of the patients were receiving prophylactic headache treatment. Sleep was assessed using the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Epworth Sleepiness Scale (ESS), and Sleep Hygiene Index (SHI). Psychological status was measured with the Hospital Anxiety and Depression Scale (HADS). Headache-related disability was assessed using the Headache Impact Test-6 (HIT-6) as a continuous outcome. Separate multivariable linear regression models were constructed for each headache group. Results: Both headache groups showed significantly impaired sleep and higher anxiety and depression scores compared with controls (all p < 0.001). HIT-6 scores did not differ between EM and ECH (p = 0.770 after Bonferroni correction). In multivariable regression, excessive daytime sleepiness (ESS) independently predicted disability in EM (B = 1.633, p = 0.033; R² = 0.571). In ECH, global sleep quality (PSQI; B = 0.701, p = 0.004) and sleep hygiene (SHI; B = 0.557, p = 0.033) were independently associated with HIT-6 (R² = 0.562). No significant multicollinearity was observed (all VIF < 2.5). Conclusions: Sleep disturbance is prevalent in both EM and ECH; however, the sleep domains associated with disability differ between phenotypes. Daytime sleepiness is more relevant in EM, whereas global sleep quality and sleep hygiene are more strongly associated with disability in ECH. These findings support a phenotype-specific approach to sleep assessment in headache management. Full article

To address the challenge of surrounding rock instability in deep-buried tunnels crossing fractured fault zones, this study focuses on the Xigu Tunnel of the Lanzhou–Hezuo Railway. A combination of laboratory triaxial tests, an optimized multi-source advanced geological prediction workflow, and a site-specific parameter-weakened Mohr–Coulomb numerical simulation is employed to systematically reveal the physical–mechanical properties, spatial distribution, and deformation response of fractured rock masses under excavation-induced disturbance. The triaxial test results show that the average peak strength of the surrounding rock reaches 149.04 MPa; however, significant variability is observed among samples, and the failure mode exhibits a typical brittle–shear composite feature. The measured cohesion and internal friction angle are 20.57 MPa and 49.91°, respectively, indicating high intrinsic strength of individual rock blocks. Nevertheless, due to the presence of densely developed joints and crushed structures, the overall mass is loose and highly sensitive to dynamic disturbances such as blasting and excavation, revealing a unique mechanical paradox of high-strength rock blocks with low overall rock mass stability in deep-buried fractured zones. Joint TSP (Tunnel Seismic Prediction Ahead) and ground-penetrating radar (GPR) prediction reveals decreased P-wave velocity, increased Poisson’s ratio, and intensive seismic reflection interfaces; a quantitative index system for identifying the boundaries of narrow deep-buried fractured zones is proposed based on these geophysical characteristics. Combined with geological face mapping, these results confirm the existence of a highly fractured zone approximately 130 m in width, characterized by well-developed joints, heterogeneous mechanical properties, and localized risks of blockfall and groundwater ingress. The developed numerical model, with parameters weakened based on triaxial test and geological prediction data, effectively reproduces the deformation law of the fractured zone, and the simulation results agree well with field monitoring data, with peak displacement concentrated at section DK4 + 595, thus accurately identifying the center of the fractured belt as a key engineering validation result of the integrated technical framework. During construction, based on the identified spatial characteristics of the fractured zone and the proposed targeted support insight, enhanced dynamic monitoring and targeted support measures at the fractured zone center are required to ensure structural safety and long-term stability of the tunnel. This study develops an integrated engineering-oriented technical framework for deep-buried tunnels crossing narrow fractured zones, and provides novel mechanical insights and quantitative identification indices for such complex geological engineering scenarios. Full article

Lithium-ion batteries in hybrid solar-grid systems experience complex electro-thermal dynamics and stochastic mode switching that threshold-based battery management systems fail to capture. This paper proposes a hybrid deviation detection framework that treats anomaly detection as a trajectory-consistency problem over a power-feasible Markov jump nonlinear system. A disturbance-robust invariant operating region is first established under explicit current bounds. A reachable-set equivalence is then derived, linking residual consistency to disturbance-augmented trajectory membership. Building on this structure, Isolation Forest empirically estimates the support of admissible electro-thermal trajectories, capturing nonlinear and mode-dependent behaviors not fully described by the analytical disturbance model. A unified sequential detection rule integrates structural constraint violations, model-based residual deviations, and empirical support inconsistencies into a coherent real-time monitor. The framework is validated on a hybrid solar-grid platform with a 6 W photovoltaic panel, a 3.7 V 1820 mAh lithium-ion battery, and a Raspberry Pi, collecting 3976 samples over four days. Results demonstrate early detection of depletion events and mode-transition anomalies before hard threshold violations, with zero false alarms during steady operation and an overall deviation rate of 4.8%, aligning with the configured contamination level. Early warning was observed at 20% state of charge, providing a 10% margin before the hardware threshold of 10%, while 88% of detected anomalies occurred in sequences, validating the persistence rule. Real-time inference required 47 ms per cycle with a 156 MB memory footprint, confirming edge deployment feasibility. Full article

Background: Gaucher disease (GD) is a rare lysosomal storage disorder caused by mutations in the GBA1 gene. Traditionally, GD is classified into three subtypes based on the severity of neurological involvement; however, overlapping clinical features increasingly suggest a continuum of phenotypes rather than distinct categories. In this prospective observational cohort study, we conducted a multidisciplinary assessment of patients with GD to identify and monitor neurological, cognitive, auditory, and visual impairments. Materials and Methods: A comprehensive clinical and instrumental evaluation was performed at baseline and repeated at follow-up, with a median interval of 37 months (IQR 36–38). Neurological assessments included physical examination, clinical rating scales, video-EEG, and brain MRI. Cognitive status was assessed using a standardized battery of neuropsychological tests. Detailed audiological and ophthalmological evaluations were also conducted. Paired parametric or non-parametric tests were applied as appropriate, with Bonferroni correction for cognitive outcomes (p < 0.05). Results: Of the 22 patients assessed at baseline, 18 completed the follow-up evaluation. Neurological assessments showed a worsening of subtle parkinsonian signs, with significant increases in Movement Disorder Society–Unified Parkinson’s Disease Rating Scale Part III scores (p = 0.04) and non-motor symptom scores (p = 0.01). Two of the eighteen patients developed epilepsy during follow-up. A high prevalence of sleep disturbances was confirmed, with 27.8% exhibiting excessive daytime sleepiness and 16.7% reporting REM sleep behaviour disorder on standardized questionnaires. Compared with baseline, cognitive assessments revealed a higher proportion of patients with performance below normative population scores in at least one cognitive domain, particularly memory. Sensorineural hearing loss was confirmed in 11 of 15 patients (73.3%) who underwent audiological evaluation, with progressive worsening of audiometric thresholds observed in 7 of 11 (64%). Ophthalmological evaluations showed no changes in visual acuity or OCT findings; however, multifocal electroretinography abnormalities were detected in 12 of 13 patients. Conclusions: Through in-depth phenotyping, this study identifies measurable neurological, cognitive, and sensory progressive changes in patients with GD over time, supporting the value of tailored, multidisciplinary long-term care strategies to monitor and address emerging clinical needs in this rare disease. Full article

Modern pollen rain studies provide essential calibration for interpreting fossil pollen records, particularly in montane environments. This study explores pollen–vegetation relationships along an altitudinal transect in the Rarău Massif (Eastern Carpathians, Romania). Eight moss cushion samples collected between 1215 and 1619 m a.s.l. were analysed palynologically and compared with eight paired vegetation surveys. Multivariate analyses, including hierarchical clustering, Mantel tests, NMDS, and Procrustes analysis, were applied to evaluate floristic and palynological similarity in relation to altitude. Pollen spectra are dominated by Picea, reflecting the prevalence of spruce forests characteristic of the montane belt, while Abies and Pinus occur in lower proportions, indicating a secondary role. Broad-leaved taxa such as Fagus, Betula, and Alnus complement the arboreal pollen signal, whereas thermophilous taxa Quercus and Tilia represent extra-local pollen input from lower altitudes. Herbaceous and shrub taxa are generally underrepresented in the pollen record relative to field observations. Pollen taxa associated with anthropogenic disturbance (Plantago, Rumex, Artemisia and Urtica) show a constant presence, which may suggest localized human influence likely linked to grazing and tourism. Statistical results show weak and non-significant correlations between pollen composition, vegetation structure, and altitude. Overall, modern pollen rain reflects the dominant vegetation structure of the studied montane belt but shows limited fidelity at the local floristic scale. Full article

Sleep disturbances are early hallmarks of Alzheimer’s disease (AD) and other dementias, yet the molecular mechanisms remain poorly understood. We previously showed that dipeptidyl aminopeptidase-like protein 6-knockout (DPP6-KO) mice exhibit accelerated neurodegeneration with synaptic loss, neuronal death, and circadian dysfunction resembling AD pathology. Here, we investigate whether DPP6 deficiency directly causes sleep dysregulation and assess age-dependent effects using wireless EEG/EMG telemetry, behavioral monitoring, and body temperature recordings. We found striking age-dependent sleep phenotypes in DPP6-KO mice. Adult (3-month) DPP6-KO mice showed hyperactivity-driven REM sleep increases, while aged (12-month) DPP6-KO mice developed insomnia with fragmented sleep architecture. Critically, aged DPP6-KO mice exhibited decreased REM latency, a biomarker of depression, which we confirmed by behavioral assays. Conversely, DPP6 overexpression in aged wild-type mice increased NREM duration and reduced sleep fragmentation, demonstrating a protective effect. Throughout aging, DPP6-KO mice showed dysregulated locomotor activity and body temperature rhythms, suggesting broader disruption of circadian and metabolic homeostasis. These findings establish DPP6 as a critical regulator of sleep architecture whose loss recapitulates key sleep disturbances observed in AD/dementia. The progressive nature of sleep dysfunction in DPP6-KO mice, from REM abnormalities to insomnia, parallels human disease progression and positions DPP6 as a potential therapeutic target for sleep-related symptoms in neurodegenerative disorders. Full article

This study used Global Navigation Satellite System (GNSS) observations from the China Crustal Movement Observation Network (CMONOC) and the Kunming Continuously Operating Reference Station (KMCORS) network to investigate ionospheric response characteristics over China during the geomagnetic storm of 4–6 November 2023, and to assess their impacts on CORS-based real-time kinematic (RTK) positioning performance in the low-latitude Kunming region. A quantitative assessment was conducted by integrating regional two-dimensional dTEC (%) maps over China, BeiDou Navigation Satellite System (BDS) Geostationary Earth Orbit (GEO) total electron content (TEC), the rate of TEC index (ROTI), and RTK positioning solutions to evaluate ionospheric disturbances, irregularity activity, and associated degradation in positioning performance. Results indicate that, during geomagnetic storms, ionospheric responses over China exhibit pronounced phase-dependent and latitudinal variations. During the second geomagnetic storm on 5–6 November, positive responses were dominant at mid-to-high latitudes, whereas alternating positive and negative responses were observed at low latitudes. During the recovery phase, the Kunming region successively experienced a positive ionospheric storm lasting approximately 10 h, followed by a negative ionospheric storm lasting about 7 h, with relative TEC variations reaching a maximum of approximately 90%. The GEO TEC time series was consistent with the temporal evolution of the two-dimensional dTEC (%), while ROTI increased markedly during the disturbance enhancement period (21:00 UT on 5 November to 07:00 UT on 6 November 2023). During periods of enhanced ionospheric response and irregularities, RTK positioning performance was observed to deteriorate markedly. The fixed-solution rate at medium-to-long baseline stations decreased from nearly 100% to close to 0%, accompanied by an increase in vertical positioning errors to approximately 20 cm, whereas short-baseline stations were only minimally affected. These results indicate that ionospheric disturbances during geomagnetic storms exert a pronounced impact on CORS-based RTK positioning services in the Kunming region, with the magnitude of this impact being closely related to baseline length. Full article