Development of the Korean construction job exposure matrix (KoConJEM) based on experts' judgment using the 60 consolidated occupations for construction workers.

BACKGROUND: This study was conducted as an effort to develop a Korean construction job exposure matrix (KoConJEM) based on 60 occupations recently consolidated by the construction workers mutual aid association for use by the construction industry. METHODS: The probability, intensity, and prevalence of exposure to 26 hazardous agents for 60 consolidated occupations were evaluated as binary (Yes/No) or four categories (1 to 4) by 30 industrial hygiene experts. The score for risk was calculated by multiplying the exposure intensity by the prevalence of exposure. Fleiss' kappa for each hazardous agent and occupation was used to determine agreement among the 30 experts. The JEM was expressed on a heatmap and a web-based dashboard to facilitate comparison of factors affecting exposure according to each occupation and hazardous agent. RESULTS: Awkward posture, heat/cold, heavy lifting, and noise were hazardous agents regarded as exposure is probable by at least one or more experts in all occupations, while exposure to asphalt fumes was considered hazardous in the smallest number of occupations (n = 5). Based on the degree of agreement among experts, more than half of the harmful factors and most occupations showed fair to good results. The highest risk value was 16 for awkward posture for most occupations other than safety officer. CONCLUSIONS: The KoConJEM provides information on the probability, intensity, and prevalence of exposure to harmful factors, including most occupations employing construction workers; therefore, it may be useful in the conduct of epidemiological studies on assessment of health risk for construction workers.

Development of occupation-based exposure matrix of lead for Korean workers: challenges and opportunities.

OBJECTIVES: Industry- and occupation-based carcinogen exposure matrices play a pivotal role in preventing occupational cancer. While the Korean CARcinogen EXposure (K-CAREX) has been developed in recent years to assess exposure prevalence and intensity by industry, the feasibility of constructing an occupation-based exposure matrix remains unexplored. Hence, the objective of this study is to explore the potential of combining the nationwide work environment measurement database (WEMD) and the special health examination database (SHED) to develop a comprehensive occupation-based exposure matrix. METHODS: The WEMD provides information on airborne lead measurements, including industry codes, but it does not include data related to occupations. In contrast, the SHED contains information on both occupation and blood lead levels. By integrating these 2 databases, we attempted to assess airborne lead exposure levels by occupation. Additionally, we performed a rank correlation analysis to compare the airborne exposure levels with corresponding blood lead levels according to occupation. RESULTS: A total of 35 425 workers who both wore air samplers for lead and underwent special health examinations for lead were extracted between 2019 and 2021. An occupation-based exposure matrix was developed to evaluate the intensity of lead exposure across a range of occupations, encompassing 51 minor occupations and 70-unit occupations. Rank correlation analyses showed strong positive correlations between airborne lead and blood lead measurements according to occupation. CONCLUSIONS: Our study findings suggest that combining 2 nationwide surveillance databases can be an effective approach for creating an occupation-based exposure matrix. However, our results also highlight several limitations that need to be addressed in future studies to improve the accuracy and reliability of such matrices.

Pectin Nanoporous Structures Prepared via Salt-Induced Phase Separation and Ambient Azeotropic Evaporation Processes.

Polysaccharide nanoporous structures are suitable for various applications, ranging from biomedical scaffolds to adsorption materials, owing to their biocompatibility and large surface areas. Pectin, in particular, can create 3D nanoporous structures in aqueous solutions by binding with calcium cations and creating nanopores by phase separation; this process involves forming hydrogen bonds between alcohols and pectin chains in water and alcohol mixtures and the resulting penetration of alcohols into calcium-bound pectin gels. However, owing to the dehydration and condensation of polysaccharide chains during drying, it has proven to be challenging to maintain the 3D nanoporous structure without using a freeze-drying process or supercritical fluid. Herein, we report a facile method for creating polysaccharide-based xerogels, involving the co-evaporation of water with a nonsolvent (e.g., a low-molecular-weight hydrophobic alcohol such as isopropyl or n-propyl alcohol) at ambient conditions. Experiments and coarse-grained molecular dynamics simulations confirmed that salt-induced phase separation and hydrogen bonding between hydrophobic alcohols and pectin chains were the dominant processes in mixtures of pectin, water, and hydrophobic alcohols. Furthermore, the azeotropic evaporation of water and alcohol mixed in approximately 1:1 molar ratios was maintained during the natural drying process under ambient conditions, preventing the hydration and aggregation of the hydrophilic pectin chains. These results introduce a simple and convenient process to produce 3D polysaccharide xerogels under ambient conditions.

Evaluation on the Sex-Specific Association Between Cigarette Smoke Exposure and Inflammation Markers-C-Reactive Protein and White Blood Cell Count.

INTRODUCTION: Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent. AIMS AND METHODS: Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature. RESULTS: A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (p = .002), whereas no significant increase was found in female smokers compared to female nonsmokers (p = .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (p = .018), whereas no significant association was found in female smokers (p = .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes. CONCLUSIONS: WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies. IMPLICATIONS: Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.

Decentering from Emotions in Daily Life: Dynamic Associations with Affect, Symptoms, and Wellbeing.

Decentering is thought to be protective against a range of psychological symptoms, but little is known about the outcomes of decentering as a momentary state in daily life. We used ecological momentary assessment (42 reports across one week) to examine the temporal ordering of the associations of decentering with affect, dysphoria, participant-specific idiographic symptoms, and wellbeing. We also hypothesized that greater decentering predicts less inertia (persistence) of each variable, and weakens the association of affect with dysphoria, idiographic symptoms, and wellbeing. Results in 345 community participants indicated that decentering and these variables were mutually reinforcing over time, and that greater decentering was associated with less inertia of negative affect and dysphoria. Decentering generally predicted reduced impact of positive and negative affect on dysphoria symptoms, but results were mixed when predicting idiographic symptoms or wellbeing. Clinical implications and refinements for theory on decentering are discussed.

Preparation and characterization of lysozyme loaded liposomal dry powder inhalation using non-ionic surfactants.

Delivering protein drugs through dry powder inhalation (DPI) remains a significant challenge. Liposomes offer a promising solution, providing protection for proteins from external environment and controlled release capabilities. Furthermore, the use of non-ionic surfactants plays a crucial role in protecting the activity of proteins because of how the surfactants positioning themselves at the liquid-gas interface during the spray-drying process. In this study, lysozyme-loaded liposomal DPI formulations were prepared using various non-ionic surfactants, including polysorbate 80, poloxamer 188, poloxamer 407, and sucrose stearate. Lysozyme solution and 1,2-distearoyl-sn-glycero-3-phosphatidylcholine liposomes were subjected through high-pressure homogenization to form lysozyme-loaded liposomes. Formulations of homogenized lysozyme liposomes were spray-dried and further characterized. The particle size of reconstituted liposomal lysozyme DPI was from 129.5 to 816.9 nm. The formulations showed encapsulation efficiency up to 32.5% with zeta potential value of around - 30 mV, and spherical structures were observed. The aerosol dispersion performance of the dry powder inhalers was evaluated with emitted doses reaching up to 103% and fine particle fractions up to 28.4%. Significantly higher lysozyme activity was confirmed in formulation with drug to PS 80 ratio of 1: 0.5 w/w (92.1%) compared to that of formulation containing no surfactant (59.8%). The formulation stood out as the only formulation that maintained protein activity while demonstrating good aerosol performance.

Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data.

BACKGROUND: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. METHODS: A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994-2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987-2021 was also performed. RESULTS: A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by -6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of -12% annually. CONCLUSIONS: Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.

Neural response to rewards moderates the within-person association between daily positive events and positive affect during a period of stress exposure.

Stress and neural responses to reward can interact to predict psychopathology, but the mechanisms of this interaction are unclear. One possibility is that the strength of neural responses to reward can affect the ability to maintain positive affect during stress. In this study, 105 participants completed a monetary reward task to elicit the reward positivity (RewP), an event-related potential sensitive to rewards. Subsequently, during a stressful period, participants reported on their affect nine times a day and on daily positive and negative events for 10 days. Even during heightened stress, experiencing more positive events was associated with increased positive affect. The RewP significantly moderated this association: Individuals with a larger RewP reported greater increases in positive affect when they experienced more positive events, relative to individuals with a smaller RewP. A blunted RewP might contribute to stress susceptibility by affecting how much individuals engage in positive emotion regulation during stress.

Korean Society of Endourology and Robotics (KSER) recommendation on the diagnosis, treatment, and prevention of urolithiasis.

This article provides evidence-based recommendations and expert opinions to aid urologists in making optimal decisions regarding managing urolithiasis in various clinical scenarios. The most frequently asked questions by urologists in their clinical practice have been collected and answered in the form of FAQs; based on the latest evidence and expert opinions. The natural history of urolithiasis is divided into active treatment and silent phases, with the active treatment stage divided into typical and special situations and peri-treatment management. The authors address 28 key questions, offering practical guidance for the proper diagnosis, treatment, and prevention of urolithiasis in clinical practice. This article is expected to be served as a valuable resource for urologists.

Chronic stress in peer relationships moderates the association between pubertal development and neural response to emotional faces in adolescence.

Adolescence is a period of heightened risk for multiple forms of psychopathology, partly due to greater exposure to interpersonal stress. One way that interpersonal stress may increase risk for psychopathology is by altering the normative development of neural systems that support socio-affective processing. The late positive potential (LPP) is an event-related potential component that reflects sustained attention to motivationally-salient information and is a promising marker of risk for stress-related psychopathology. However, it is not clear how the LPP to socio-affective information changes across adolescence, nor whether exposure to stress with peers interferes with normative developmental differences in the LPP to socio-affective content during this period. In 92 adolescent girls (10-19 years old), we assessed the LPP to task-irrelevant emotional and neutral faces, as well as behavioural measures of interference following the presentation of these faces. Adolescents at more advanced stages of puberty showed a smaller LPP to emotional faces, but adolescents exposed to greater peer stress exhibited a larger LPP to these stimuli. Additionally, for girls exposed to lower levels of peer stress, more advanced pubertal development was associated with a smaller LPP to emotional faces, whereas for girls exposed to higher levels of peer stress, the association between pubertal development and the LPP to emotional faces was not significant. Neither stress nor pubertal stage was significantly associated with behavioural measures. Combined, these data suggest that one pathway through which stress exposure increases risk for psychopathology during adolescence is by interfering with the normative development of socio-affective processing.

Parsing patterns of reward responsiveness: Initial evidence from latent profile analysis.

Variation in reward responsiveness has been linked to psychopathology. Reward responsiveness is a complex phenomenon that encompasses different temporal dimensions (i.e., reward anticipation or consumption) that can be measured using multiple appetitive stimuli. Furthermore, distinct measures, such as neural and self-report measures, reflect related but distinct aspects of reward responsiveness. To understand reward responsiveness more comprehensively and better identify deficits in reward responsiveness implicated in psychopathology, we examined ways multiple measures of reward responsiveness jointly contribute to distinct psychological problems by using latent profile analysis. Specifically, we identified three profiles of reward responsiveness among 139 female participants based on their neural responses to money, food, social acceptance, and erotic images and self-reported responsiveness to reward anticipation and consumption. Profile 1 (n = 30) exhibited blunted neural responses to social rewards and erotic images, low self-reported reward responsiveness, but average neural responses to monetary and food rewards. Profile 2 (n = 71) showed elevated neural response to monetary rewards, average neural responses to other stimuli, and average self-reported reward responsiveness. Profile 3 (n = 38) showed more variable neural responses to reward (e.g., hypersensitivity to erotic images, hyposensitivity to monetary rewards), and high self-reported reward responsiveness. These profiles were differentially associated with variables generally linked to aberrations in reward responsiveness. For example, Profile 1 was most strongly associated with anhedonic depression and social dysfunction, whereas Profile 3 was associated with risk-taking behaviors. These preliminary findings may help to elucidate ways different measures of reward responsiveness manifest within and across individuals and identify specific vulnerabilities for distinct psychological problems.

A Newly Developed Hematuria Grading System May Predict the Status of Stone-Free and Acute Pyelonephritis of Minimally Invasive Renal Stone Surgery.

OBJECTIVES: The aim of this study was to evaluate the level of hematuria and the presence of clots during retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mPCNL) to predict surgical outcomes. MATERIALS AND METHODS: The data of patients who underwent RIRS and mPCNL were analyzed separately. A hematuria grading (HG) system was classified into five grades based on the presence of blood clots and any visible stones according to the irrigation settings. Inter-observer reliability of the grading system was assessed using intra-class correlation and Spearman's rho. RESULTS: The HG system showed high agreement among examiners, with high intra-class reliability and a strong correlation between RIRS and mPCNL groups. The stone density of the Houns-field unit was the most important factor in determining the hematuria across the development and validation groups of RIRS and mPCNL patients. Multivariate logistic regression analysis showed that the HG system was a significant predictor for remnant stones in the PCNL group and the probability of acute pyelonephritis or sepsis in the RIRS group. The high hematuria group showed lower basketing difficulty with the basket with a blue marker instrument than with others. CONCLUSIONS: The new HG system shows excellent inter-observer reliability and a correlation with a gradual increase in stone density and surgical difficulty.

Characteristics of Peak Exposure of Semiconductor Workers to Extremely Low-Frequency Magnetic Fields.

OBJECTIVES: Peak exposure to extremely low-frequency magnetic fields (ELF-MF) among semiconductor workers was characterized by type of factory, operation, and job. METHODS: A portable EMDEX meter was used to monitor the ELF-MF exposure of 117 semiconductor workers who are involved in wafer fabrication (fab) and assembly operations. ELF-MF measurements were logged every 3 s and categorized by process and job or activity during working hours. Two values of 0.5 and 1 µT were adopted subjectively as cutoff values of peak exposure levels based on a literature review. RESULTS: All semiconductor workers who were involved in diffusion, ion implanter operation, module, and chip test were exposed to ELF-MF higher than 0.5 µT during their entire working time. Engineers who maintained electric facilities in the semiconductor operations were exposed to the highest ELF-MF peak levels (2.5 µT on average above 0.5 µT and 3.6 µT on average above 1 µT). Operators working in chip testing showed the highest daily contribution of their peak levels to their daily average ELF-MF exposure levels (98.1% and 83.9%). In contrast, chemical mechanical planarization engineers, wafer test operators, and administrative workers outside clean rooms showed average exposure to less than 0.5 µT and a low proportion of duration of time exposed above either the 0.5 µT or 1 µT peak level points, along with a low daily contribution of peak exposure levels (16.0, 11.9, and 18.7%). CONCLUSIONS: Most of the activities and working locations next to machines generating ELF-MF in semiconductor operations showed high contributions of ELF-MF peak exposure to daily exposure dose despite their relative minor fraction of workers' daily time.

Deep-Learning Segmentation of Urinary Stones in Noncontrast Computed Tomography.

Background: Noncontrast CT (NCCT) relies on labor-intensive examinations of CT slices to identify urolithiasis in the urinary tract, and, despite the use of deep-learning algorithms, false positives remain. Materials and Methods: A total of 410 NCCT axial scans from patients undergoing surgical treatment for urolithiasis were used for model development. The deep learning model was customized to combine a urolithiasis segmentation with per-slice classification for screening. Prediction models of the axial, coronal, and sagittal views were trained, and an additive model with an intersection of the coronal and sagittal predictions added to the axial outcome was introduced. Automated quantification of clinical metrics was evaluated in three-dimensional models of urinary stones. Results: The axial model detected 88.92% of urinary stones and produced a dice similarity coefficient of 87.56% in the urolithiasis segmentation. For urolithiasis (>5 mm), the sensitivity of the axial model reached 95.10%. False positives were reduced to 0.34 per patient using an ensemble of individual models. The additive model improved the sensitivity to 90.97% by detecting more small urolithiasis (<5 mm). All clinical metrics of size, long-axis diameter, volume, mean stone density, stone heterogeneity index, and skin-to-stone distance showed a strong correlation of R2 > 0.964. Conclusions: The proposed system could reduce the burden on the physician for imaging diagnosis and help determine treatment strategies for urinary stones through automated quantification of clinical metrics with high accuracy and reproducibility.

Metal(loid)-specific sources and distribution mechanisms of riverside soil contamination near an abandoned gold mine in Mongolia.

Tailings were discharged to the Boroo River from gold mining by amalgamation, resulting in soil contamination near the river. To identify the sources and distribution mechanisms of each metal(loid) in the soil, a total of 184 soil samples were collected near the river and analyzed for As, Cd, Cu, Pb, Zn, and Hg contents. According to the positive matrix factorization result, three factors affected the contamination levels: the application of Hg for gold mining (Factor 1), light minerals containing Cu and Zn (Factor 2), and heavy minerals containing As and Cd (Factor 3). Soil samples were classified into four groups by hierarchical clustering. Groups A and B seemed to be affected by light and heavy minerals discharged in early and later stages of ore processing, respectively. The spatial distribution of the groups suggested differentiation in travel distances by specific gravity. Groups C and D showed high Hg contents implying the effect of Hg mismanagement and spill accidents. The study results show that the distribution of soil contaminants near rivers in mining areas is controlled by the specific gravity of minerals discharged to the environment (e.g., river), ore processing stages, and insufficient recovery and/or spills of Hg, which will help establish restoration measures.

Pretreatment C-reactive protein-to-albumin ratio predicts clinical outcomes in patients with peripheral T-cell lymphoma.

PURPOSE: Peripheral T-cell lymphoma (PTCL) is an aggressive and heterogenous T-cell lymphoid malignancy. The prognostic value of C-reactive protein-to-albumin ratio (CAR) has never been assessed in PTCL. MATERIALS AND METHODS: This study retrospectively reviewed the medical records of 76 patients diagnosed with various subtypes of PTCL. A CAR cutoff value of 0.794 was determined, and clinical outcomes, including response rate, overall survival (OS), and progression-free survival (PFS), were compared between the high (> 0.794) and low (≤ 0.794) CAR groups. RESULTS: After induction therapy, complete response was achieved in 8 (32.0%) and 39 patients (76.5%) in the high and low CAR groups, respectively. During the median follow-up of 57.5 months, the high CAR group had significantly worse 5-year PFS and 5-year OS rates. Even with adjustment for the International Prognostic Index (≥ 3), Prognostic Index for PTCL-unspecified (≥ 3), and T cell score (≥ 2), high CAR remained a significant prognostic factor for PFS (hazard ratio [HR]: 4.01, 95% confidence interval [CI] 2.04-7.86, p < 0.001) and OS (HR: 2.97, 95% CI: 1.33-6.64, p = 0.008). CONCLUSION: CAR may play a complementary role in predicting prognosis in patients with PTCL, considering its simplicity, objectivity, and easy accessibility.

Characteristics of workers' compensation claim applications for COVID-19 infections in South Korea.

This study aimed to identify the major industries and jobs with the highest proportion of workers' compensation (WC) claims for COVID-19, characterize COVID-19 WC claims in terms of their demographic properties and disease severity, and identify factors influencing the approval of COVID-19 WC claims as occupational disease. A total of 488 workers who submitted COVID-19-related claims to the Korea Workers' Compensation and Welfare Service (KWCWS) from January 2020 to July 2021 were analyzed. A Fisher's exact test was employed to associate the severity of COVID-19 infection with demographic properties. The highest proportion of all COVID-19 WC claims compensated as occupational disease (N=462) were submitted by healthcare workers (HCW=233, 50%), while only 9% (N=41) of the total originated from manufacturing industries. The 5% (N=26) of the COVID-19 WC claims accepted were evaluated as severe (N=15) and acute respiratory distress syndrome (N=9). A total of 71% (N=329) of the COVID-19 patients compensated (N=462) were from workplaces with infection clusters. A total of 26 WC cases were rejected for various reasons, including unclear infection routes, infection at private gatherings (including within families), no diagnosis, and more. Given our findings, we suggest an official system should be established to detect and compensate more job-associated infectious diseases like COVID-19.

A Pilot Establishment of the Job-Exposure Matrix of Lead Using the Standard Process Code of Nationwide Exposure Databases in Korea.

Background: The purpose of this study is to construct a job-exposure matrix for lead that accounts for industry and work processes within industries using a nationwide exposure database. Methods: We used the work environment measurement data (WEMD) of lead monitored nationwide from 2015 to 2016. Industrial hygienists standardized the work process codes in the database to 37 standard process and extracted key index words for each process. A total of 37 standardized process codes were allocated to each measurement based on an automated key word search based on the degree of agreement between the measurement information and the standard process index. Summary statistics, including the arithmetic mean, geometric mean, and 95th percentile level (X95), was calculated according to industry, process, and industry process. Using statistical parameters of contrast and precision, we compared the similarity of exposure groups by industry, process, and industry process. Results: The exposure intensity of lead was estimated for 583 exposure groups combined with 128 industry and 35 process. The X95 value of the "casting" process of the "manufacture of basic precious and non-ferrous metals" industry was 53.29 µg/m3, exceeding the occupational exposure limit of 50 µg/m3. Regardless of the limitation of the minimum number of samples in the exposure group, higher contrast was observed when the exposure groups were by industry process than by industry or process. Conclusion: We evaluated the exposure intensities of lead by combination of industry and process. The results will be helpful in determining more accurate information regarding exposure in lead-related epidemiological studies.

The usefulness and ergonomics of a new robotic system for flexible ureteroscopy and laser lithotripsy for treating renal stones.

PURPOSE: To investigate the usefulness and ergonomics of a newly developed robotic system for flexible ureteroscopy (easyUretero). MATERIALS AND METHODS: During in vitro testing, six participants performed renal stone removal four times in an artificial kidney-ureter-bladder model. Each participant manipulated a single-use digital flexible ureteroscope (LithoVue) with their hands and the robotic system, sequentially. We compared the task completion times of each participant. The ergonomics of and operational satisfaction with each procedure were assessed by questionnaires. In vivo tests evaluated the operability and safety of the robotic system in two live female pigs. We checked that all the steps of flexible lithotomy for renal stones could be completed individually. RESULTS: The task completion time with the robotic system during in vitro testing was significantly longer than with manual ureteroscopy regardless of the operator's competence level (expert professors: 282.6±92.4 seconds vs. 73.6±43.3 seconds, p<0.001; fellows: 247.5±57.7 seconds vs. 95.8±43.7 seconds, p<0.001; residents: 281.3±111.0 seconds vs. 188.6±138.6 seconds, p<0.001). The residents took more time to remove the upper and mid caliceal stones with the robotic system. The ergonomic evaluation was better for the robotic system, but operational satisfaction was lower, and there was no statistical difference among the groups. In vivo tests showed that all the steps of robotic flexible ureteroscopy could be completed without difficulty. No safety issues were encountered during the procedure. CONCLUSIONS: The robotic system (easyUretero) was ergonomic and safe for flexible ureteroscopy and laser lithotripsy for renal stones.