Search Results (82)

Hiking poles significantly benefit hikers by improving balance, reducing strain on lower limbs and spine, and redistributing workload to the upper extremities. However, exercise at moderate altitude often causes respiratory muscle fatigue (RMF), which limits performance. This study investigated the effect of mountaineering poles use on RMF during submaximal uphill walking, examining cardiovascular and pulmonary responses, perceived exertion (RPE) and perceived dyspnea (DYS). Seventeen hikers (36.2 ± 11.9 years) walked a 6.4 km trail (1010 m elevation) at 65–85% of their heart rate maximum (HR_max), with and without poles (wp/np). Maximum voluntary ventilation (MVV₁₂), inspiratory capacity (IC), expiratory reserve volume (ERV), vital capacity (VC), tidal volume (VT), ventilation (VE), forced expiratory volume (FEV₁), forced vital capacity (FVC), respiration rate (RR), heart rate (HR), oxygen saturation (SaO₂), blood lactate accumulation (BLC), energy expenditure (EE), RPE, DYS, and performance (Time) were measured at the trail’s end (2070 m). Paired samples t-tests and Wilcoxon signed-rank tests were used for comparison. IC was higher when using poles compared to hiking without poles (Δ = 0.21 L, p = 0.011, adjusted p = 0.187). Non-significant differences were observed for MVV₁₂, ERV, VT, VE, RR, and BLC. In conclusion, under the investigated submaximal conditions, pole use did not significantly alter the overall physiological load or respiratory muscle endurance. These findings suggest that recreational hikers can utilize poles for mechanical support, without additional ventilatory or cardiovascular strain. Full article

Background: Discontinuing mechanical ventilation during cardiopulmonary bypass (CPB) is common but may adversely affect postoperative pulmonary function. This study aimed to evaluate the impact of stopping ventilation during CPB on postoperative gas exchange, radiographic findings, intensive care unit (ICU) length of stay (LOS), mortality, reintubation, re-exploration, and bleeding. Methods: A prospective observational study was performed involving adult patients scheduled for elective cardiac surgery requiring CPB. Participants were divided into ventilated and non-ventilated groups according to intraoperative strategy. Postoperative arterial carbon dioxide levels (PaCO₂), arterial partial pressure of oxygen (PaO₂), the PaO₂/FiO₂ ratio (P/F ratio), arterial oxygen saturation (SaO₂), and the ratio of PaCO₂ to minute ventilation (PaCO₂/MV) were measured before the induction of anesthesia (within 5 min after transportation into the operating room), postoperatively within 5–10 min after transportation to the ICU, and in a 24 h postoperative period. Chest X-ray data, mechanical ventilation time, LOS in ICU, re-exploration, reintubation, and bleeding parameters were documented. Analyses were also conducted with the estimation of the age effect and BMI. Results: Individuals in the non-ventilated group exhibited lower postoperative P/F ratios and elevated postoperative PaCO₂ and PaCO₂/MV ratios. The difference in gas exchange leveled off within 24 h. There was no difference in the incidence of atelectasis (postoperatively in a 24 h period), mechanical ventilation time, LOS in ICU, or mortality. However, the incidence of bleeding was higher in the non-ventilated group (χ² = 5.78, p = 0.016). Interestingly, postoperative PaCO₂ and PaCO₂/MV peaked in the 50-year age group. Conclusions: Continued mechanical ventilation during CPB correlates with better postoperative gas exchange, better CO₂ clearance, and fewer bleeding events. The results suggest that maintaining low tidal volume ventilation during CPB may provide benefits, especially for patients aged 50 years. Full article

Background/Objectives: Children with single left ventricle (SLV) anatomy following Fontan palliation are at high risk for subclinical ventricular dysfunction, which may not be detected by conventional echocardiographic measures. Our objectives are as follows: (1) to assess myocardial and atrial strain profiles in pediatric Fontan patients with SLV using 2-dimensional speckle-tracking echocardiography (2D-STE), (2) to compare these findings with a healthy control group, (3) to investigate correlations with conventional echocardiographic and functional parameters. Methods: A single-center study of 66 pediatric patients, who underwent echocardiographic evaluation and a 6 min walk test (6 MWT). Conventional, 3D, and strain-based echocardiographic parameters were compared between groups. Correlations with clinical and functional indices were assessed using ANCOVA, analysis, generalized additive models, and Pearson’s correlation coefficient. Results: Fontan patients showed significantly reduced 6 MWT distances compared to controls (mean difference: 201.6 m, p < 0.0001). Post-test heart rate (HR) and oxygen saturation were significantly impaired (HR: 104.6 vs. 100.8 bpm, p = 0.0012; SaO₂: 90.3% vs. 99.8%, p < 0.0001). Fontan patients showed statistically significant differences in nearly all the 2D parameters. Three-dimensional echocardiography revealed significantly lower left ventricular (LV) ejection fraction (p = 0.0020), higher end-diastolic (p = 0.0275) and end-systolic volumes (p = 0.0125) in the study group. Global longitudinal strain (LV_GLS) was reduced in Fontan patients compared to controls (p < 0.0001), with significant differences across nearly all LV segments. Left atrial (LA) reservoir and conduit strain were markedly decreased, while contractile strain remained similar. LV_GLS was negatively correlated with IVCT (r = −0.50, p = 0.0175). The LA reservoir strain (LASr_AC) significantly correlated with MAPSE (r = 0.43, p = 0.0461). Conclusions: In pediatric Fontan patients, myocardial and atrial strain imaging reveals subclinical dysfunction despite preserved conventional ejection fraction. Full article

Background: This study examined the impact of amnestic mild cognitive impairment (aMCI) on dynamic changes in cerebrocortical oxygen saturation (ScO₂) and O₂ extraction during acute, moderately intense, normobaric hypoxia and reoxygenation in elderly adults (71 ± 6 years old). Methods: Thirty-two aMCI and thirty-five control subjects participated. Inspired and expired fractions of O₂ and CO₂ (mass spectrometry), arterial O₂ saturation (SaO₂) and prefrontal ScO₂ (near-infrared spectroscopy), heart rate, tidal volume and breathing frequency were monitored while subjects breathed hypoxic air (fractional inspired O₂ 0.10) for 3–5 min (aMCI: 4.5 ± 0.7 min; control: 4.5 ± 0.6 min) and recovered on room air. Values at the pre-hypoxia baseline, the first and last min of hypoxia and the first min of recovery were compared within and between groups using two-factor ANOVA. Results: Despite a similar baseline SaO₂ in aMCI (97.2 ± 1.6%) and control (97.3 ± 1.3%) subjects, prefrontal ScO₂ was lower (p < 0.05) in the aMCI subjects in both the left (67.0 ± 1.7% vs. 69.6 ± 4.5%) and right (66.8 ± 4.6% vs. 69.4 ± 4.1%) hemispheres. Hypoxia similarly decreased SaO₂ and ScO₂ in both groups (last min hypoxia, aMCI vs. control subjects: SaO₂ 76.6 ± 5.3% vs. 77.4 ± 6.1%, left prefrontal ScO₂ 54.0 ± 4.9% vs. 55.2 ± 6.4%, right prefrontal ScO₂ 56.0 ± 4.3% vs. 58.2 ± 4.4%). Upon the resumption of room-air breathing, ScO₂ recovered at similar rates in aMCI and control subjects. Conclusions: Although it produced a greater deoxygenation in the left vs. the right prefrontal cortex, acute, normobaric, moderate hypoxia was well tolerated by elderly adults, even those with aMCI. Dynamic changes in cerebral oxygenation during hypoxia and recovery were unaltered by aMCI. Brief, moderate hypoxia does not impose more intense cerebrocortical oxygen depletion in elderly adults with aMCI, despite pre-hypoxic cerebrocortical oxygenation below that of their non-MCI counterparts. Full article

Background/Objectives: Pharmaceutical cocrystallization offers a promising strategy to enhance drug properties while preserving molecular integrity. Ezetimibe, a BCS Class II hypolipidemic agent, faces therapeutic limitations due to poor aqueous solubility. This study aimed to systematically evaluate cocrystallization of ezetimibe with organic acid (benzoic, tartaric, or succinic acid) at varying stoichiometric ratios (1:0.5–1:2) to optimize physicochemical properties and oral bioavailability. Methods: Cocrystals were prepared via solvent evaporation (SEV) and solvent/anti-solvent (SAS) methods. Structural characterization included Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder/single-crystal X-ray diffraction (PXRD/SCXRD). Physicochemical performance was assessed through saturation solubility, in vitro dissolution, and in vivo pharmacokinetics in male Sprague Dawley rats (n = 4/group). Results: Benzoic acid cocrystals (1:2 ratio, SEV) showed O−H⋯N hydrogen bonding (FTIR band shifts: 2928 → 3264 cm⁻¹) and novel crystalline phases (12.4°, 16.7°, and 24.9°). SCXRD confirmed monoclinic P2₁/n symmetry (a = 5.42 Å, b = 5.05 Å) for benzoic acid cocrystals. Ezetimibe/benzoic acid cocrystals (1:2) achieved 64-fold solubility enhancement and 2× faster dissolution vs. pure ezetimibe. Pharmacokinetics revealed 3× higher Cmax (18.38 ng/mL) and 4× greater AUC (40.36 h·ng/mL) for optimized cocrystals. Tartaric and succinic acid cocrystals showed moderate improvements, with melting points intermediate between parent compounds. Conclusions: Both stoichiometry and preparation method strongly determined cocrystal performance. Benzoic acid at a 1:2 ratio via SEV demonstrated superior solubility, dissolution, and bioavailability, addressing ezetimibe’s formulation challenges. These findings underscore the potential of rational cocrystal design to overcome solubility barriers in oral dosage development, particularly for hydrophobic therapeutics. Full article

This study aimed to explore the added value and usage of laser Doppler flowmetry (LDF) in conjunction with continuous tissue (arterial) oxygen saturation (SO₂) monitoring, electrical pulp testing (EPT), cold stimulation (CS) testing, and apical X-rays (RX). LDF data were evaluated in relation to three different scenarios. LDF records of all four upper incisors from 30 randomly selected patients aged 21–40 were analysed in relation to the following scenarios: (a) simultaneous SO₂ measurements using a pre-manufactured splint handled by an experienced LDF dentist, (b) EPT, and (c) CS. A total of 120 teeth were analysed, of which 11 were non-vital (7 denervated and 4 traumatised). Data assessment showed the following mean LDF values: vital teeth: 23.6 Perfusion Units (PU), SD 6.3 and SaO₂ of 88.7%, SD 17.1. For non-vital teeth, the mean LDF value was 16.1 PU (SD 11.8) and the mean SO₂ value was 70.8% (SD 31.9). The standard deviation was found to be twice as high for non-vital teeth as for vital teeth. No direct relationship was found between LDF and SO₂ values at low SO₂. For vitality discrimination, the ROC curves showed an area under the curve of 0.799 for LDF and 0.643 for SO₂. EPT data assessment showed a mean value of 18.1 (SD 19.7) out of a possible score of 0–80. This was distributed as follows: seven non-vital teeth (80/80); 109 vital teeth; and four undecided teeth. This was compared to the LDF and SO₂ results. The data assessment showed nine non-vital teeth, 108 vital teeth, and three undecided teeth in comparison to LDF and SO₂ results. Conclusion: LDF and SO₂ do not complement each other sufficiently in detecting non-vital teeth when the selection criteria are applied. While LDF clearly contributes, the vital or non-vital classification still depends on a combination of X-ray, sensitivity, and vitality tests. Full article

Background and Objectives: Apelin-13 and its receptor (APJ) are increasingly recognized as key regulators of metabolic pathways that may contribute to the pathophysiology of obstructive sleep apnea (OSA) syndrome. This study aimed to investigate the relationship between circulating apelin-13 and APJ levels with disease severity in patients diagnosed with OSA, considering the impact of obesity. Materials and Methods: A total of 105 subjects were enrolled: 35 obese patients with OSA, 35 non-obese patients with OSA, and 35 healthy controls. Demographic data, polysomnographic parameters, metabolic markers, Apelin-13, and APJ levels were compared across groups. Patients were further classified as mild-moderate, or severe OSA for subgroup analysis. Correlations between Apelin-13, APJ, BMI, minimum oxygen saturation (Min SaO₂), and apnea–hypopnea index (AHI) were assessed. ROC analysis was used to examine the potential of Apelin-13 and APJ to predict severe OSA. Results: Apelin-13 levels were significantly higher in obese patients with OSA compared to non-obese OSA and controls (p < 0.001), whereas APJ levels were lowest in obese OSA subjects. Apelin-13 showed significant positive correlations with BMI (r = 0.63, p < 0.001) and AHI (r = 0.33, p = 0.005), and a negative correlation with Min SaO₂ (r = −0.35, p = 0.004). Conversely, APJ levels were negatively correlated with BMI (r = −0.60, p < 0.001) and AHI (r = −0.40, p = 0.002) and positively correlated with minimum SaO₂ (r = 0.40, p = 0.002). In severe OSA, insulin and HOMA-IR levels were significantly higher than in mild-moderate OSA (p = 0.02 and p = 0.003, respectively). However, there was no significant difference in Apelin-13 and APJ levels by OSA severity category. ROC analysis revealed that neither Apelin-13 nor APJ demonstrated sufficient diagnostic performance to predict severe OSA (AUC = 0.50 and 0.63, respectively). Conclusions: Apelin and APJ levels are correlated with key metabolic and hypoxic parameters in OSA, indicating that the apelin/APJ system may play a compensatory role in mitigating hypoxia-induced and metabolic complications. However, neither marker alone provides sufficient predictive value for disease severity, emphasizing the need for further studies to clarify the mechanisms and potential clinical applications of this system in OSA management. Full article

Background: Expert guidelines recommend using pulse oximetry (PO) in the delivery room to monitor oxygen saturation (SpO₂) and heart rate (HR). Umbilical cord pulse oximetry (UCP) is a novel concept that, despite being postductal, could provide accurate measurements of SpO₂ and HR, as it overcomes barriers associated with skin pigmentation. Methods: This pilot study used NONIN pulse oximetry on an intact umbilical cord that underwent deferred cord clamping (DCC) to evaluate umbilical cord SpO₂ in a preterm asphyxiated ovine model (N of 5) with an HR of <100 bpm. The UCP HR served as a surrogate marker for umbilical vessel flow. A receiver operator characteristic (ROC) curve was used to evaluate UCP parameters with arterial saturations (SaO₂) and carotid HR between 2 and 10 min. Results: Following asphyxia, five preterm lambs underwent DCC for 4 min. A significant relationship was noted between SaO₂ and umbilical SpO₂ (area under the curve (AUC) of 0.907, CI 0.857–0.968, p < 0.0001) along with carotid and umbilical HR (AUC) of 0.842 (CI 0.663–0.902, p < 0.0001). Conclusions: In a translational preterm model, UCP accurately predicted preductal SaO₂ and carotid HR (a surrogate for umbilical flow). Using UCP in the delivery room will help guide supplemental oxygen and determine the optimal duration of clamping the umbilical cord. These proof-of-concept studies/pilot findings require validation with larger animal cohorts and newborn infants. Full article

This study presents the synthesis of manganese molybdenum tetraoxide (MnMoO₄)-based nanoparticles and then their experimental demonstration as saturable absorbers (SAs) in erbium-doped fiber lasers (EDFLs). The MnMoO₄ nanoparticles were prepared and then embedded between the fiber ferrule to act as an SA to generate Q-switched pulsed operation in EDFLs. For the characterization, scanning electron microscopy (SEM) was employed to confirm the particle size of the prepared MnMoO₄ nanoparticles, and the SA optical properties were further investigated by measuring their modulation depth and saturation intensity. By implementing the prepared SA within the cavity, the measured results revealed that under pump power ranging from 28 to 312.5 mW, the laser exhibited Q-switched pulse durations varying from 15.22 to 2.35 µs and repetition rates spanning from 24.98 to 88.11 kHz. The proposed EDFL system delivered an average output power between 0.128 and 2.95 mW, pulse energies ranging from 5.12 to 33.49 nJ, and peak power from 0.281 to 6.26 mW. The laser stability was also confirmed by continuously noticing the pulse duration, emission wavelengths, and pulse repetition rates for 4 h. Finally, a numerical model based on a nonlinear Schrödinger equation (NLSE) was employed to validate both experimental and theoretical results of the passive Q-switched EDFL. These findings highlight the potential of EDFLs utilizing MnMoO₄-based SAs for potential applications in pulsed laser sources. Full article

Background: The US Food and Drug Administration (FDA) and International Organization for Standardization (ISO) clearance standards for the clinical use of smart device pulse oximetry require in-laboratory human hypoxemia testing in healthy human individuals using arterial blood gas analysis. Methods: We evaluated the SpO₂ measurements of the Samsung smartphone (Galaxy S9/10) and smartwatch (Galaxy 4) at stable arterial oxygen saturations (SaO₂) between 70 and 100% in 24 healthy participants. Testing followed FDA/ISO-stipulated procedures for pulse oximetry performance validation, which include questionnaire estimation of skin tone based on Fitzpatrick estimation of skin types I–VI. During testing, inspired oxygen, nitrogen, and carbon dioxide partial pressures were monitored and adjusted via partial rebreathing circuits to achieve stable target arterial blood oxygen (SaO₂) plateaus between 70% and 100%. Arterial blood samples were taken at each plateau, with device SpO₂ readings taken at each sample extraction. An ABL-90FLEX blood gas analyzer determined arterial blood sample SaO₂. Bias, calculated from device readings minus corresponding arterial blood measurements, was reported as root mean square deviation (RMSD). Results: Combined Participants demographics were: 62.5% female; median age 26 years (range 21–46); and race/ethnicity 16.7% African American, 33.3% Asian, 12.5% multi-ethnic, and 37.5% Caucasian. Fitzpatrick Skin Scale-identified skin tones were: white–fair (I&II), 20.8%; average–light brown (III–IV), 54% and brown–black (V–VI), 25%. There were no adverse events. The RMSD values of SpO₂ measurements were: smartphone 2.6% (257 data pairs) and smartwatch 1.8% (247 data pairs). Conclusions: Device SpO₂ demonstrated RMSD < 3.0% to SaO₂, meeting FDA/ISO clearance standards at the time of study. However, additional testing in persons with darker skin tones is necessary. Smartphones and paired wearables, when cleared for clinical use following revision of FDA clearance standards, may expand access to remote pulse oximetry. Full article

Aim: The objective of this research was to compare two methods of conscious sedation (midazolam vs. sevoflurane) used for performing oral surgical procedures in the older adult population by analyzing dental treatment-related anxiety levels, the quality of sedation, and potential hemodynamic changes during the interventions, as well as post-recovery symptoms and patient satisfaction levels. Methods: A total of 104 patients underwent oral surgery with intravenous (age: 84.00 ± 8.410; 17 men and 36 women) and inhalation conscious sedation (age: 82.73 ± 8.809; 18 men and 33 women). Anxiety levels were recorded using the Modified Corah Dental Anxiety Scale (MDAS) and the Hamilton Anxiety Rating Scale (HARS). During the intervention, the heart rate, systolic/diastolic blood pressure, oxygen saturation, episodes of hypoxia (<90%SpO2), sedation duration, and Sedation–Agitation Scale (SAS) values were monitored. Upon completion of their treatment, all patients completed three questionnaires which evaluated their recall of the intervention, postoperative symptoms, and recommendation of the sedation method used. Results: Anxiety levels were slightly higher in the midazolam group (MDAS score: 9.60 ± 5.849; HARS score: 27.19 ± 6.802) compared to the sevoflurane group (MDAS score: 8.37 ± 5.063; HARS score: 24.92 ± 5.199), with no statistical significance (MDAS, p = 0.453/HARS, p = 0.065). No significant differences in the analyzed hemodynamic parameters were observed between the two groups. However, SAS values were significantly higher in the sevoflurane group (p = 0.006), while the sedation duration was longer in the midazolam group (p = 0.000). Postoperative symptoms, particularly gastrointestinal disturbances and dry mouth, were significantly more prevalent in the midazolam group, while there were no differences in neurological symptoms between the two groups. The majority of patients expressed a preference for either of these sedation methods. Conclusions: Sedation with agents such as midazolam and sevoflurane appears to be quite safe, given the absence of relevant hemodynamic changes. Midazolam has been shown to be effective for a longer duration, as well as to have a lower risk of developing greater digestive problems during the postoperative period. On the contrary, sevoflurane produced a greater sensation of dry mouth. Both sedative agents are perceived by the older adult population as satisfactory, recommending their use. Full article

Background/Objectives: Childhood obesity appears to be an alarmingly growing global threat. Current evidence has shown that obesity can be successfully managed with interventions targeting movement skills, motor coordination and physical activity. However, data concerning physiotherapy practice are limited. We aimed to assess the impact of therapeutic exercise on the 6-minute walk test (6-MWT) in obese children and adolescents. Methods: A total of 31 obese children and adolescents (BMI > 30 kg/m²), 18 males and 13 females, aged from 8 to 18 years, were enrolled. Two study groups were formed: the control group (Group A), comprising ten children; and the intervention group (Group B), comprising 21 children. Daily exercise habits were obtained via interview; anthropometric data (weight, height and BMI) were recorded; and 6-MWT parameters, blood pressure and oxygen saturation (SaO₂) were assessed before and after a 4-month intervention program consisting of breathing and aerobic exercises. Results: There was a statistically significant increase in 6-minute walk distance (+43.34, p < 0.001) and an improvement in body weight (p < 0.01), blood pressure (p < 0.01) and oxygen saturation (p < 0.03) in Group B after the 4-month training program. Conclusions: All results highlight the potential of physical exercise in clinical practice to improve functional status and achieve weight loss. Future randomized controlled trials, including individualized therapeutic exercise programs in larger samples of obese children, are much anticipated. Full article

Background and Objectives: Coronary sinus oxygen saturation is a useful indicator of health and disease states. However, it is not routinely used in clinical practice. Cardiovascular magnetic resonance imaging (CMR) oximetry can accurately estimate oxygen saturation in the pulmonary artery. This research aimed to provide a method for calculating coronary sinus oxygen saturation (ScsO₂) from pulmonary artery oxygen saturation (SpaO₂) that could be applied to CMR. Materials and Methods: A systematic literature review was conducted to identify prior work that included invasive measures of ScsO₂ and either SpaO₂ or right ventricular oxygen saturation. This revealed one study with appropriate data (ScsO₂ and SpaO₂ measurements, n = 18). We then carried out agreement and correlation analyses. Results: Regression analysis demonstrated a statistically significant, positive relationship between ScsO₂ and SpaO₂, giving a regression equation of ScsO₂ = −31.198 + 1.062 × SpaO₂ (r = 0.76, p < 0.001). A multivariable regression analysis of all reported variables, excluding SpaO₂, independently identified superior vena cava oxygen saturation (SsvcO₂) and arterial oxygen saturation (SaO₂) as predictors of ScsO₂ (r = 0.78, p < 0.001), deriving the equation ScsO₂ = −452.8345 + 4.3579 × SaO₂ + 0.8537 × SsvcO₂. Conclusions: In this study, we demonstrated a correlation between coronary sinus oxygen saturation and pulmonary artery oxygen saturation, allowing the estimation of ScsO₂ from SpaO₂. This association enables the estimation of ScsO₂ from purely CMR-derived data. We have also described a second model using arterial and superior vena cava saturation measurements, providing an alternative method. Future validation in larger, independent cohorts is needed. Full article

Owing to their remarkable characteristics, two-dimensional (2D) layered, MAX phase materials have garnered significant attention in the field of optoelectronics in recent years. Herein, a novel MAX phase ceramic material (Mo₂TiAlC₂) was prepared into a saturable absorber (SA) by the spin-coating method for passively Q-switching (PQS), and its nonlinear optical absorption properties were characterized with a Tm:YAlO₃ (Tm:YAP) nanosecond laser. The structure characteristics and composition analysis revealed that the Mo₂TiAlC₂ material exhibits a well-defined and stable structure, with a uniform thin film successfully obtained through spin coating. In this study of a PQS laser by employing a Mo₂TiAlC₂-based SA, an average output power of 292 mW was achieved when the absorbed pump power was approximately 4.59 W, corresponding to a central output wavelength of 1931.2 nm. Meanwhile, a stable pulse with a duration down to 242.9 ns was observed at a repetition frequency of 47.07 kHz, which is the narrowest pulse width recorded among PQS solid-state lasers using MAX phase materials as SAs. Our findings indicate that the Mo₂TiAlC₂ MAX phase ceramic material is an excellent modulator and has promising potential for ultrafast nonlinear photonic applications. Full article

We report passively Q-switched pulse operation through an erbium-doped fiber laser (EDFL) utilizing graphene oxide/titania (GO/TiO₂) nanorods as a saturable absorber. The GO/TiO₂ nanorods were fabricated using a Sol–gel-assisted hydrothermal method. The optical and physical characterization of the GO/TiO₂ was then characterized using a field-emission-scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), and diffuses reflectance spectroscopy (DRS). To investigate the performance of the Q-switched EDFL based on the GO/TiO₂ SA, the prepared nanorods were mechanically deposited on the fiber ferrule employing adhesion effects of in-dex-matching gel. This integration of the nanorod SA resulted in a self-starting Q-switching opera-tion initiated at a pump power of 17.5 mW and sustained up to 306.9 mW. When the pump range was tuned from 17.5 to 306.9 mW, the emission wavelength varied from 1564.2 to 1562.9 nm, pulse repetition rates increased from 13.87 kHz to 83.33 kHz, and pulse width decreased from 30.27 µs to 3.75 µs. Moreover, at the maximum pump power of 306.9 mW, the laser exhibited an average output power of 0.74 mW, a peak power of 1.54 mW, and a pulse energy of 8.88 nJ. Furthermore, this study investigates the GO/TiO₂ damage threshold and prolonged stability of the proposed EDFL system. Full article