Search Results (14,885)

Background: Obstructive sleep apnea (OSA) is increasingly recognized as a systemic disorder associated with insulin resistance and elevated risk of type 2 diabetes. While continuous positive airway pressure (CPAP) is the standard therapy, its long-term metabolic benefits remain inconsistent. The metabolic impact of upper airway surgery is less well defined. Methods: In this retrospective study, 49 patients with polysomnography-confirmed OSA who underwent upper airway surgery were evaluated. Respiratory and metabolic parameters—including apnea–hypopnea index (AHI), fasting plasma glucose, fasting insulin, glycated hemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR)—were assessed preoperatively and at 6 months postoperatively. Associations between changes in AHI (ΔAHI) and insulin resistance (ΔHOMA-IR) were analyzed using correlation and receiver operating characteristic (ROC) analyses. Results: Significant improvements were observed in both respiratory and metabolic parameters. AHI decreased from 46.6 ± 25.8 to 20.7 ± 14.1 events/h (p < 0.001). Fasting plasma glucose, insulin levels, and HOMA-IR were significantly reduced postoperatively (all p < 0.05), while HbA1c showed a downward trend. Reduction in AHI was moderately correlated with improvement in insulin resistance (r = 0.527, p < 0.001). ROC analysis demonstrated modest discriminative ability of ΔAHI for identifying normalization of insulin resistance (AUC = 0.62). Conclusions: Upper airway surgery was associated with significant improvements in insulin resistance and glycemic parameters in patients with OSA. The correlation between airway improvement and metabolic change supports a physiological link between upper airway obstruction and insulin sensitivity. These findings suggest that upper airway surgery may represent a clinically relevant adjunct within multimodal strategies for metabolic risk reduction, particularly in patients unable to tolerate CPAP therapy. Full article

Impacted mandibular third molars present a common challenge in oral surgery, often associated with postoperative complications such as delayed healing and periodontal defects; therefore, optimizing adjunctive therapies is clinically important. In this study, we aimed to evaluate the efficacy of platelet-rich fibrin (PRF) and preoperative azithromycin in modulating inflammation and enhancing wound healing following surgical extraction of impacted mandibular third molars. In this prospective clinical study, healthy subjects aged 18–50 years were randomly assigned to three groups: a control group receiving standard postoperative amoxicillin therapy, a PRF group receiving PRF with standard therapy, and a PRF-plus-azithromycin group receiving PRF, standard therapy, and a single preoperative dose of azithromycin. Clinical parameters were assessed and cytomorphometric analysis was performed preoperatively and postoperatively. Clinical parameters generally improved over time in all groups (p < 0.001). Differences between groups were observed for interincisal distance, Landry Index, and pain scores, with a trend toward more favorable outcomes in the combined-therapy group. Cytomorphometric analysis revealed cellular alterations in the control group, relative stability in the PRF group, and intermediate changes in the combined-therapy group. Within the limitations of this study, the combination of PRF and preoperative azithromycin showed potential benefits in several postoperative outcomes. However, given the study design and sample characteristics, these findings should be considered preliminary and require confirmation in larger prospective studies before definitive clinical recommendations can be made. Full article

Background: Osteochondral lesions of the talus (OLT) remain a challenging condition due to the limited regenerative potential of articular cartilage. Conventional bone marrow stimulation (BMS) techniques often result in fibrocartilage formation with inferior biomechanical properties. This study aimed to evaluate the safety and preliminary clinical efficacy of an arthroscopically assisted, single-stage injection of a heparin-conjugated fibrin hydrogel (HCFH) for OLT treatment. Methods: Twelve patients with symptomatic OLT underwent arthroscopic debridement, microfracturing, and HCFH injection containing autologous mesenchymal stromal cells (MSCs) and growth factors. Safety was assessed through systematic monitoring of adverse events (graded according to Common Terminology Criteria for Adverse Events criteria), wound healing, and serial laboratory inflammatory markers (leukocytes, erythrocyte sedimentation rate, C-reactive protein) during early and late follow-up. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) and American Orthopedic Foot and Ankle Society score (AOFAS) preoperatively and at 6 and 12 months. Morphological assessment was performed using magnetic resonance imaging (MRI) with the modified Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scoring system, evaluated independently by two blinded musculoskeletal radiologists. Results: No serious adverse events (Grade III–IV) were observed during the 12-month follow-up. All adverse events were mild (Grade I) and self-limited. A transient postoperative elevation in inflammatory markers was observed, returning to clinically acceptable levels by day 14. Significant improvements were noted in pain (VAS decreased from 6.0 to 2.0) and ankle function (AOFAS increased from 70.0 to 90.6) (p < 0.001). MRI demonstrated progressive morphological improvement, with the MOCART score increasing from 34.16 ± 17.1 at 6 months to 75 ± 5.43 at 12 months (p < 0.001). This increase corresponded with imaging features consistent with tissue maturation over time. The favorable MOCART outcomes observed in this study may be explained by the regenerative properties of heparin-conjugated fibrin hydrogels; however, larger randomized controlled trials with longer follow-up are needed to confirm the durability of the regenerated tissue. Interobserver agreement was substantial to almost perfect for MOCART scoring (κ = 0.68–0.84), with perfect agreement observed for surface assessment, bony defect/overgrowth, and cysts. Conclusions: Within the limitations of this study, single-stage HCFH injection demonstrated an acceptable safety profile and favorable preliminary clinical and radiological outcomes at 12 months. These findings suggest potential regenerative capability; however, controlled studies with larger cohorts and longer follow-up are required to determine comparative efficacy and long-term durability. Full article

Background: Osteoporosis (OP) is a chronic disease characterized by decreased bone mass and altered microarchitecture, leading to bone fragility and fracture risk. To date, although carbohydrate-binding proteins Galectins 1 and 3 (Gal-1/Gal-3) have been implicated in bone metabolism, inflammation and aging, their levels and potential regulation by microRNAs (miRNAs) have not yet been investigated in OP. Methods: In this pilot study, 13 osteoporotic (OP) and 10 non-osteoporotic (NOP) patients, all undergoing hip or knee arthroplasty, were enrolled. Due to the unavailability of DXA measurements, OP classification was based on cortical bone ratio and distal femoral cortical index. Clinical parameters and blood samples were collected preoperatively, while bone biopsies were obtained intraoperatively. ELISA and qRT-PCR were used to quantify Gal-1, Gal-3, miR-22 and miR-21 in bones and sera. Correlations with clinical parameters were assessed. Results: Several OP biopsies exhibited a reduction in Gal-1 levels, whereas miR-22, Gal-3 and miR-21 were increased. Serum analysis revealed similar dysregulation patterns, with increased miR-21 and decreased Gal-1 and miR-22 levels in several OP patients. Conclusions: This pilot study suggests a putative association of Gal-1, Gal-3, and their previously reported related miRNAs with osteoporotic bone status, indicating their potential involvement in OP-related bone metabolism. Full article

The rapid expansion of molecular point-of-care (POC) diagnostics into decentralized settings, including emergency departments, retail pharmacies, and home environments, has shifted the burden of diagnostic performance from laboratory professionals to heterogeneous, often non-expert users. While traditional evaluation frameworks focus on analytical and clinical validity, they often overlook the impact of human-system interactions on real-world reliability. This review introduces the concept of Operational Validity: the ability of a diagnostic system to preserve its intended performance when operated by intended users within the constraints of real-world workflows and environments. To establish a rigorous foundation for this concept, this study provides a critical comparative analysis contrasting Operational Validity against traditional clinical evaluation dimensions (analytical validity, clinical validity, and clinical utility) and post-market metrics. While existing literature outlines isolated usability principles, the significance of this study lies in its synthesis of these fragmented concepts into a formalized, lifecycle-based “Operational Validity” framework that explicitly maps the causal mechanisms connecting initial user interaction directly to downstream clinical outcomes. By synthesizing international standards (IEC 62366-1) alongside the newly finalized May 2026 U.S. Food and Drug Administration (FDA) guidance on the Content of Human Factors Information in Medical Device Marketing Submissions, we examine how human factors engineering (HFE) and usability engineering serve as the methodological foundation for operational validity. We analyze the specific complexities of molecular workflows, identify key parameters of use-related failure modes in pre-analytical and interpretation stages, and detail the mandatory role of iterative formative and final summative usability testing in mitigating these risks. Finally, we propose a lifecycle-based approach to HFE that integrates design, simulated-use validation, and post-market surveillance. Establishing operational validity is essential to ensure that the high analytical sensitivity of molecular POC platforms translates into consistent clinical utility across the full spectrum of decentralized care. Full article

It is an accepted paradigm in the already matured industry of Quantum Key Distribution (QKD) implementations that when the quantum channel is attacked or unresponsive, the system reverts to classical security. Thus, in times of crises, when the quantum system is severely damaged, the saving resort is considered to be the classical solution. This paper explores the opposite approach. In the case of disaster, when parts of the classical part of the key distribution system are broken, are there any possible crisis management options to give some limited functionality? The result of this research shows that if the classical channel fails, the quantum channel can still produce and distribute keys. The experimental results of the contingency QKD show that, using positive operator-valued measurements (POVMs), keys can still be produced and shared. The scheme described in this paper uses the quantum channel only to distribute imperfect keys. Any one distributed key has a theoretical overlap of approximately $75\%$ between Alice’s key and Bob’s key, respectively. The experimental POVM circuit is implemented with two different Naimark dilation approximations: one using $R_z$ gates and the other using $R_y$ gates. The practical implementation results are close to the theoretical analysis. As the keys have a partial overlap, the encryption/ decryption algorithm also needs to adjust to this reality. The encryption/decryption algorithm used in the experiments is a repetition algorithm that is simple but shows the resilience of the scheme. Ultimately, the classical channel is not used during the contingency QKD at all, while the quantum channel is assumed trusted under a restricted adversary model in which Eve is limited to individual attacks. Under this model, partial secrecy is retained for all non-zero channel error rates below a pre-agreed threshold. Full article

Background: Pressure injuries (PIs) are common in patients with limited mobility and may require flap reconstruction for definitive management. However, postoperative complications and PI recurrence frequently occur. Certain flap types may be more prone to poor outcomes. This study evaluated outcomes after flap reconstruction for PIs in a medically complex population. Methods: We performed a retrospective review of patients who underwent flap reconstruction for sacral, ischial, trochanteric, or lateral malleolar PIs by a single surgeon at a tertiary care center between 2015 and 2023. Patient demographics, comorbidities, neurologic status, wound characteristics, flap type, and postoperative outcomes were collected. Outcomes were analyzed at the flap level. Results: Sixty-eight patients underwent 101 flap reconstructions. Most patients were male (68%), and spinal cord injury was present in 71%. Medical comorbidity burden was high, including anemia (61%), malnutrition (42%), preoperative osteomyelitis (44%), stool exposure near the wound (49%), and near-universal urinary incontinence. Postoperative complications were common across flap types, most commonly wound dehiscence and PI recurrence. New PIs developed at non-operative sites in about 14% of reconstructions during recovery. During the eight-year follow-up period, 19 (28%) patients expired and 21% of reconstructions were complicated by recurrence at the operative site. Conclusions: Flap reconstruction remains an important treatment for advanced PIs but is associated with high complication and recurrence rates in patients with substantial comorbidities and limited mobility. These findings support careful patient selection, preoperative optimization, and multidisciplinary postoperative care focused on preventing new PIs. Full article

Identity verification across pre-operative and post-operative facial images remains a challenging task, particularly following eyelid surgery, where localized periocular changes can disrupt conventional face recognition systems. This research introduces a novel verification framework using an ensemble-based autoencoder-initialized Siamese eye-region periocular verification network designed to remain resilient to surgically induced appearance variation. The proposed approach integrates anatomy-guided periocular normalization with a Siamese deep metric learning architecture, initialized via unsupervised autoencoder pretraining, enabling the model to acquire periocular-specific representations before supervised learning. Robustness in this data-limited clinical setting is enhanced through a combination of constrained periocular augmentation, dropout-based regularization, L2 weight decay, validation-guided checkpoint selection, staged hard-negative mining, validation-weighted multi-seed ensemble learning, and bootstrap-based threshold calibration. Experimental evaluation demonstrates recognition rates of 96.08% on the test set. These results indicate that the proposed framework maintains discriminative periocular identity representations under post-surgical appearance variation while remaining robust in a limited-data clinical setting. Full article

Background and Objectives: Patients undergoing incisional hernia repair constitute a clinically heterogeneous population with variable postoperative outcomes. Conventional risk models based on isolated risk factors may inadequately capture this complexity. This study aimed to identify data-driven clinical phenotypes and evaluate their association with surgical outcomes. Methods and Materials: A retrospective cohort of 1262 patients undergoing retromuscular incisional hernia repair (Rives–Stoppa technique) was analyzed. Unsupervised clinical phenotyping was performed using latent class analysis based on seven preoperative variables. Model selection was guided by Akaike information criterion (AIC), Bayesian information criterion (BIC), entropy, and clinical interpretability. Postoperative outcomes were compared across phenotypes. Results: Three distinct phenotypes were identified: metabolic (34.6%), structural (33.9%), and frailty (31.5%). The structural phenotype showed the highest complication (22.7%) and recurrence rates (8.6%), while the frailty phenotype had the lowest complication burden (14.6%). The metabolic phenotype was characterized by obesity and diabetes, consistent with increased wound-related morbidity. Cluster robustness was supported by internal validation metrics and sensitivity analyses. Conclusions: In this retrospective single-center cohort, distinct clinical phenotypes with different outcome profiles were identified among patients undergoing incisional hernia repair, supporting the concept that this population comprises clinically heterogeneous subgroups with distinct patterns of vulnerability. These findings should be considered preliminary and hypothesis-generating. Further external validation and prospective studies are required to determine the clinical utility of phenotype-based risk stratification. Full article

Background/Objectives: This investigation was performed because corticosteroid injections are commonly used for symptomatic relief in patients with meniscal deficiency, yet their effect on graft survivorship and postoperative outcomes following meniscal allograft transplantation (MAT) remains poorly understood, with limited literature specifically addressing this topic. The aim of this study is to evaluate whether preoperative intra-articular corticosteroid injections (ICS) are associated with reoperation after MAT. Secondary aims included comparing reoperation-free survival, patient-reported outcome measures (PROMs), and patient acceptable symptom state (PASS) achievement. Methods: A retrospective review of 130 adults undergoing meniscal allograft transplantation (MAT) between 2011 and 2023 was performed. Patients with documented corticosteroid injection (CSI) status and ≥2 years of follow-up were included. Exclusion criteria included prior meniscal allograft transplantation, receipt of non-corticosteroid injections (e.g., hyaluronic acid or platelet-rich plasma), concomitant osteotomy procedures, multi-ligament knee reconstruction or inadequate follow-up. Propensity score matching (2:1 no steroid: steroid) based on age, sex, body mass index, fixation technique, operative compartment, and concomitant procedures yielded 54 matched patients (35 no steroid, 19 steroid). The primary outcome was ipsilateral knee reoperation, categorized as major reoperation (revision MAT, anterior cruciate ligament reconstruction, osteochondral allograft transplantation, conversion to total knee arthroplasty, meniscectomy and meniscus repair). Minor reoperations included irrigation and debridement, lysis of adhesions or manipulation under anesthesia, hardware removal, chondroplasty, and synovectomy. Reoperation-free survival was assessed using Kaplan–Meier analysis. PROMs and PASS were compared using adjusted regression models. Statistical significance was set at p < 0.05. Results: Baseline characteristics and follow-up were comparable between groups (7.6 ± 3.5 vs. 6.6 ± 3.2 years; p = 0.30). Overall reoperation occurred in 37.1% of patients in the no-steroid group and 31.6% in the steroid group (p = 0.771). Major reoperation rates were similar (17.1% vs. 15.8%; p = 1.000. There was no significant difference in minor reoperations between groups (20.0% vs. 10.5%; p = 0.468). Kaplan–Meier analysis demonstrated no difference in reoperation-free survival (p = 0.903), with comparable survival at the 1-, 2-, and 5-year time points. No individual subtypes differed significantly between groups. PROMs and PASS achievement were also similar, with no statistically significant differences observed. Conclusions: Preoperative corticosteroid injection was not associated with increased reoperation risk, inferior reoperation-free survival, or worse patient-reported outcomes following meniscal allograft transplantation. However, given the study’s limited power, lack of detailed injection characteristics, and the use of a heterogeneous complication outcome, these findings should be interpreted cautiously, as further investigation is warranted. Full article

Under weak-grid conditions, grid-following (GFL) control of doubly fed induction generators (DFIGs) suffers from reduced stability margins, deteriorated dynamic performance, and intensified oscillations near the stability boundary. To address these issues, a pre-synchronized switching strategy between GFL and grid-forming (GFM) modes, triggered by locally measured operating variables, is proposed. Based on the GFL control model, the evolution of system dynamics with decreasing short-circuit ratio is analyzed, thereby elucidating how reduced grid strength progressively weakens robustness and disturbance rejection and eventually leads to instability. To characterize this deterioration, a set of normalized indices is constructed to quantify the oscillation levels of active power, phase-locked loop frequency, and point of common coupling voltage, enabling reliable identification of control-performance deterioration. A pre-synchronization scheme based on a virtual power closed loop is then developed, allowing the target mode to converge to the current operating point prior to takeover and enabling smooth bidirectional switching between GFL and GFM modes. Hardware-in-the-loop results demonstrate that the proposed strategy accurately detects GFL performance deterioration and effectively suppresses boundary oscillations while mitigating switching transients, thereby enhancing the adaptability of DFIGs to variations in grid strength. Full article

Matrilysins and stromelysins play a vital role in cancer, facilitating tumor invasion and metastasis. The aim of this study was to investigate the diagnostic significance of selected matrilysins and stromelysins in comparison to routine tumor markers in gynecological malignancies, relative to a control group (benign tumors and healthy women). Preoperative plasma levels of selected metalloproteinases were determined using ELISA, while levels of CA125, SCC-Ag, and HE4 by CMIA. In endometrial and cervical cancers, matrilysins (MMP-7 and MMP-26) exhibited higher diagnostic utility than routine markers. Similarly, all stromelysins in cervical cancer outperformed CA125; furthermore, MMP-10 also outperformed SCC-Ag, achieving the highest diagnostic utility among all parameters tested in cervical cancer. For ovarian cancer, diagnostic utility remained highest for routine markers. In endometrial and cervical cancers, the AUCs for all studied parameters exceeded those of standard markers, while in ovarian cancer, MMP-7 had an AUC higher than HE4 and comparable to CA 125. Combined analysis of the studied parameters in diagnostic panels demonstrated that their introduction into routine diagnostics could provide tangible benefits in the detection of malignant gynecological lesions, especially the combination of MMP-7 or MMP-10 with routine markers. These results indicate the usefulness and high diagnostic power of selected MMPs in the detection of these malignancies. Full article

Background/Objectives: A macular hole represents a significant surgical condition in an increasingly aging population. Advances in surgical techniques, particularly pars plana vitrectomy with inverted internal limiting membrane (ILM) flap, have established high anatomical closure rates exceeding 90%. The prognostic factors influencing visual recovery remain incompletely understood, and it is unclear which patients can be expected to achieve optimal functional outcomes. Methods: This retrospective longitudinal study included 35 eyes of 32 patients followed for 3–12 months. Preoperative OCT parameters (minimum linear diameter, basal diameter, and hole height) and derived indices were correlated with functional outcomes, including best-corrected visual acuity (BCVA) and microperimetry, stratified as central macular sensitivity (CMS) and sensitivity at 4° and 20°. Postoperative ellipsoid zone (EZ) and external limiting membrane (ELM) integrity were also analyzed. Predictive performance was assessed using root mean square error (RMSE) and coefficient of determination (R²). A linear regression model based on BCVA served as baseline, while Extreme Gradient Boosting (XGBoost) models incorporating OCT features were developed. Feature importance was evaluated using Shapley Additive Explanations (SHAP). Results: Overall closure rate was 100%, including 91.4% Type 1 and 8.6% Type 2 closure. Models incorporating OCT parameters outperformed BCVA-based models (lower RMSE, and higher R²). Minimum linear diameter and hole height were the strongest predictors of postoperative outcomes. Microperimetry detected functional improvement beyond BCVA and correlated with EZ and ELM restoration. Conclusions: Preoperative macular hole morphology represents a key determinant of postoperative functional recovery. These structural parameters provide meaningful prognostic value beyond visual acuity alone, supporting the role of combined OCT and microperimetric assessment in predicting surgical outcomes. Full article

Methods of ridge preservation following tooth extraction, aiming to maintain alveolar bone volume and support tissue regeneration, have been extensively researched. Continuously, new approaches and materials are being explored in this context. To scientifically evaluate outcomes, the pre-implant situation is usually assessed radiologically, histologically, and/or clinically. However, the influence of ridge preservation on implant placement itself is rarely examined in depth, and if at all, the focus has been on implant stability or survival rates. Based on the assumption that preoperative radiological assessment, including cone beam computed tomography, provides only an indirect and inherently limited approximation of actual intraoperative bone condition, undetected factors such as insufficient bone density, mechanically unfavorable trabecular structure, or incompletely resorbed residual biomaterial may necessitate a shift of the implant from the preferred position originally occupied by the tooth root. We therefore established a method that evaluates and categorizes implant position in three dimensions based on radiological data post-implantation. Our data, derived from a multicenter randomized clinical trial (RCT), demonstrate that the greatest positional deviations are observed without preservation, whereas the combination of biomaterial and PRF most frequently allowed for central implant placement. The proposed method proves well suited for evaluating the outcome of ridge preservation procedures. The findings demonstrate that both the absence and presence, and further the type, of preservation have a measurable influence on the final implant positioning. Full article

Background: Patients undergoing open-heart surgery (OHS) are at risk of postoperative morbidity and mortality. Physical performance has been increasingly recognized as an important factor influencing postoperative outcomes. Therefore, the study aimed to investigate the associations and predictive value of physical performance on postoperative complications and duration of hospital stay. Methods: A prospective cohort study was conducted in 116 patients who were admitted to OHS. Preoperative assessment of physical performance, i.e., Short Physical Performance Battery (SPPB), Five Times Sit to Stand Test (5STS), gait speed (5 m walk test: 5MWT), Timed Up and Go (TUG), and handgrip strength. Duration of hospital stay and incidence of post-operative complications were recorded. Differences between participants with and without postoperative complications were analyzed using independent samples t-tests for continuous variables and chi-square tests for categorical variables. The associations between physical performance and postoperative outcomes were assessed using Spearman’s rank correlation coefficient. Hierarchical regression analysis was conducted to determine the predictive contribution of physical performance. Results: A total of 116 participants were submitted for OHS in two medical school hospitals; however, 108 individuals completed the pre-operative physical performance. The most common procedures were coronary artery bypass grafting and valve surgery. Fifty-one participants (47.22%) experienced postoperative complications, including five deaths, corresponding to 4.63% mortality. For the length of hospital stay analysis, five participants who died postoperatively were excluded, resulting in a final sample of 103 participants. Physical performance was significantly associated with the length of hospital stay (p < 0.05). Hierarchical regression analysis showed that the final prediction model explained 13.4% of the variance in length of hospital stay, with SPPB independently contributing an additional 6.0% to the model, followed by 5STS, 5MWT, handgrip strength, and TUG, which accounted for an additional 5.1%, 4.6%, 4.4%, and 3.7%, respectively. Conclusions: Preoperative physical performance was associated with length of hospital stay. While each measure explained a relatively small proportion of the variance in hospital stay, these assessments offer a simple, non-invasive, and clinically feasible approach to evaluating functional reserve before surgery. These findings highlight the importance of incorporating functional assessment into perioperative care to support risk stratification and guide rehabilitation strategies. Full article