Monte Carlo modelling of cyclotron and radioisotope center (CYRIC) at Tohoku University: a radiation protection study.

Protection against ionizing radiations is important in laboratories with radioactive materials and high energy cyclotron beams. The Cyclotron and Radioisotope Center (CYRIC) located in Tohoku University in Miyagi prefecture, Japan and is a well-known nuclear science laboratory with cyclotron beams and substantial number of high activity radioactive materials. Considering this, it is important to perform complete radiation transport computations to ensure the safety of non-occupational and occupational workers. In the present work, we have developed a complete 3-dimensional model of the main cyclotron building and radiation labs using Monte Carlo method. We have found that the dispersed photons and neutrons inside and in the surrounding of the CYRIC building pose no significant risk to occupational and non-occupational workers. The present work and the developed models would be useful in the field of radiation protection.

Hate Speech Against Asian American Youth: Pre-Pandemic Trends and The Role of School Factors.

Although hate speech against Asian American youth has intensified in recent years-fueled, in part, by anti-Asian rhetoric associated with the COVID-19 pandemic-the phenomenon remains largely understudied at scale and in relation to the role of schools prior to the pandemic. This study describes the prevalence of hate speech against Asian American adolescents in the US between 2015 and 2019 and investigates how school-related factors are associated with whether Asian American youth are victims of hate speech at school. Analyses are based on a sample of 938 Asian American adolescents (Mage = 14.8; 48% female) from the three most recently available waves (2015, 2017, and 2019) of the School Crime Supplement to the National Crime Victimization Survey. On average, approximately 7% of Asian Americans were targets of hate speech at school between 2015 and 2019, with rates remaining stable over time. Findings also indicate that students had lower odds of experiencing hate speech if they attended schools with a stronger authoritative school climate, which is characterized by strict, yet fair disciplinary rules coupled with high levels of support from adults. On the other hand, Asian American youth faced higher odds of experiencing hate speech if they were involved in school fights. Authoritative school climate and exposure to fights are malleable and can be shaped directly by broader school climate related policies, programs and interventions. Accordingly, efforts to promote stronger authoritative climates and reduce exposure to physical fights hold considerable potential in protecting Asian American youth from hate speech at school.

Variability in Standardized Mortality Rates Among Pediatric Traumatic Brain Injury Patients: A Comparative Analysis of Trauma Centers.

INTRODUCTION: Traumatic brain injury (TBI) causes significant morbidity and mortality in pediatric patients and care is highly variable. Standardized mortality ratio (SMR) summarizes the mortality rate of a specific center relative to the expected rates across all centers, adjusted for case-mix. This study aimed to evaluate variations in SMRs among pediatric trauma centers for TBI. METHODS: Patients aged 1-18 diagnosed with TBI within the National Trauma Data Bank (NTDB) from 2017 to 2019 were included. Center-specific SMRs and 95% confidence intervals identified centers with mortality rates significantly better or worse than the median SMR for all centers. RESULTS: 316 centers with 10,598 patients were included. SMRs were risk-adjusted for patient risk factors. Unadjusted mortality ranged from 16.5 to 29.5%. Three centers (1.5%) had significantly better SMR (SMR <1) and three centers (1.5%) had significantly worse SMR (SMR >1). Significantly better centers had a lower proportion of neurosurgical intervention (2.4% vs. 11.8%, p < 0.001), a higher proportion of supplemental oxygen administration (93.7% vs. 83.5%, p = 0.004) and venous thromboembolism prophylaxis (53.2% vs. 40.6%, p < 0.001) compared to significantly worse centers. CONCLUSIONS: This study identified centers that have significantly higher and lower mortality rates for pediatric TBI patients relative to the overall median rate. These data provide a benchmark for pediatric TBI outcomes and institutional quality improvement. LEVEL OF EVIDENCE: Level III. TYPE OF STUDY: Retrospective Comparative Study.

Congenital anomalies and predisposition to severe COVID-19 among pediatric patients in the United States.

BACKGROUND AND OBJECTIVE: Congenital heart defects are known to be associated with increased odds of severe COVID-19. Congenital anomalies affecting other body systems may also be associated with poor outcomes. This study is an exhaustive assessment of congenital anomalies and odds of severe COVID-19 in pediatric patients. METHODS: Data were retrieved from the COVID-19 dataset of Cerner® Real-World Data for encounters from March 2020 to February 2022. Prior to matching, the data consisted of 664,523 patients less than 18 years old and 927,805 corresponding encounters with COVID-19 from 117 health systems across the United States. One-to-one propensity score matching was performed, and a cumulative link mixed-effects model with random intercepts for health system and patients was built to assess corresponding associations. RESULTS: All congenital anomalies were associated with worse COVID-19 outcomes, with the strongest association observed for cardiovascular anomalies (odds ratio [OR], 3.84; 95% CI, 3.63-4.06) and the weakest association observed for anomalies affecting the eye/ear/face/neck (OR, 1.16; 95% CI, 1.03-1.31). CONCLUSIONS AND RELEVANCE: Congenital anomalies are associated with greater odds of experiencing severe symptoms of COVID-19. In addition to congenital heart defects, all other birth defects may increase the odds for more severe COVID-19. IMPACT: All congenital anomalies are associated with increased odds of severe COVID-19. This study is the largest and among the first to investigate birth defects across all body systems. The multicenter large data and analysis demonstrate the increased odds of severe COVID19 in pediatric patients with congenital anomalies affecting any body system. These data demonstrate that all children with birth defects are at increased odds of more severe COVID-19, not only those with heart defects. This should be taken into consideration when optimizing prevention and intervention resources within a hospital.

The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study.

BACKGROUND: COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes. METHODS: Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2, hospitalized and received supplemental O2, admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality. RESULTS: Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity. CONCLUSIONS: Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

A video-based decision aid improved knowledge and decreased decisional conflict for asymptomatic persistent endodontic lesions.

AIM: This prospective cohort study aimed to (i) evaluate patients' treatment decisions, decisional conflict and knowledge levels before and after use of a video-based decision aid (DA) on asymptomatic persistent endodontic lesions (APEL) and to (ii) elicit important decision factors for patients in the decision-making process. METHODOLOGY: A video DA modelled after the International Patient Decision Aids Standards (IPDAS) was designed. The video was pilot-tested, revised and used on 50 patients referred to the graduate endodontic clinic and presenting with an incidental finding of APEL detected on radiographs, with informed consent (DSRB 2020/00133). Recruitment was conducted from June 2020 to November 2021. Patients' treatment decisions and decision-making process were studied. Patients also completed a questionnaire on knowledge gain, decisional conflict and confidence levels. RESULTS: Forty-three patients (48 teeth) out of 50 patients chose long-term monitoring of APEL while 7 patients (7 teeth) decided on endodontic intervention. Median knowledge scores increased from 58.3 (IQR: 41.7, 75.0) to 87.5 (IQR: 75.0, 100.0) (p < .001); median decisional conflict scale (DCS) scores decreased from 25.0 (IQR: 12.5, 34.4) to 3.1 (IQR: 0, 23.8) (p < .001), and 44 (88%) patients were confident or very confident with their treatment decisions. Statistical analyses showed that asymptomatic condition of tooth was the sole decision factor with statistical significance while socioeconomic factors (age, gender, race, education and income levels) showed no significant trend. CONCLUSIONS: The majority of patients presenting with APEL in this study chose long-term monitoring over immediate intervention. Using the video-based DA in the decision-making process significantly improved patients' knowledge and decreased their decisional conflict levels.

Racial Disparity among Youth Decedents of Legal Intervention Trauma.

BACKGROUND: Legal intervention trauma (LIT) is defined as injury due to any encounter with law enforcement. This study investigates associations between demographics, violent status, and law enforcement tactics among youth decedents of LIT. STUDY DESIGN: Decedents of LIT age 26 years or younger were identified using the CDC's National Violent Death Reporting System from 2003 to 2018. Decedents were classified as "violent" if they possessed a weapon, were committing a violent crime, or if law enforcement reported justified use of force. All others were classified as "nonviolent." Law enforcement tactics were stratified into "lethal" (firearm with standard ammunition) or "less lethal" (any other) force. Differences in the racial distribution across these classifications were assessed using chi-square tests of proportions. RESULTS: We identified 1,281 youth decedents of LIT; of which, 92.5% met violent criteria. Black youths were less likely than White youths to possess a weapon (71.6% vs 77.4%, p = 0.02) and were not more likely to be committing a violent crime (63.6% vs 60.4%, p = 0.27). They were, however, more likely than White youths to experience force reported as justified by law enforcement (89.9% vs 82.4%, p = 0.002) and to experience exclusively lethal force not preceded by less-lethal tactics (94.0% vs 88.7%, p = 0.001). Among the subset of 85 cases where law enforcement reported justified use of force despite the decedent not possessing a weapon or committing a violent crime, the precipitating event was more often a traffic stop for Black youths than for White youths (28.5% vs 6.66%, p = 0.02). CONCLUSIONS: These findings indicate a racial disparity among youth decedents of LIT.

Low-drift-rate external cavity diode laser.

We present the design, construction, and simulation of a simple, low-cost external cavity diode laser with a measured free-running frequency drift rate of 1.4(1) MHz/h at 852 nm. This performance is achieved in a compact aluminum structure held inside an airtight, temperature-controlled enclosure. The high thermal conductivity of the laser cavity and the stable temperature environment inside the enclosure minimize the time-varying, spatial temperature gradients across the laser cavity. We present thermal finite element method simulations, which quantify the effects of temperature gradients, and suggest that the drift rate is likely limited by the laser-diode and piezo-aging.

Non-steroidal anti-inflammatory drugs reduce pleural adhesion in human: evidence from redo surgery.

Non-steroidal anti-inflammatory drugs (NSAIDs) reduced pleural adhesion in animal studies, but its effect on human had not been studied. A retrospective study was carried out for patients with solitary pulmonary nodules without a pre-operative tissue diagnosis positive for malignancy. The impact of the use of NSAIDs after stage one wedge resection was assessed by the degree of pleural adhesions encountered during second-stage, redo completion lobectomy. From April 2016 to March 2022, 50 consecutive patients meeting the inclusion criteria were included, and 44 patients were selected for analysis after exclusion (Treatment group with NSAID: N = 27; Control group without NSAID: N = 17). The preoperative characteristics and the final tumor pathologies were similar between the groups. The use of NSAID was significantly associated with lower risk of severe pleural adhesions and complete pleural symphysis (risk difference = -29%, p = 0.03). After controlling the effect of tumor size and chest drain duration, only the use of NSAID was statistically associated with the lowered risk of severe pleural adhesions and complete pleural symphysis. No statistically significant effects of NSAID on operative time (p = 0.86), blood loss (p = 0.72), and post-operative length of stay (p = 0.72) were demonstrated. In human, NSAIDs attenuated the formation of pleural adhesions after pleural disruptions. Physicians and surgeons should avoid the use of NSAIDs when pleural adhesion formation is the intended treatment outcome.

Debunking Myths of Gender Informed Care: What Every Pediatric Surgeon Should Know.

As the transgender population in the United States grows, gender-affirming care is becoming increasingly relevant to the practice of pediatric surgery. Medical care for the transgender and gender diverse population is a politically charged topic with significant complexity and opportunities for clarification. It is important for providers to better understand this population's unique health and social needs. This review aims to debunk long-standing myths regarding gender-affirming care and highlight the current therapeutic and legislative landscapes within the scope of pediatric surgical practice. LEVEL OF EVIDENCE: IV.

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia.

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression toward severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.

Center Volume and Survival Relationship for Neonates With Congenital Diaphragmatic Hernia Treated With Extracorporeal Life Support.

OBJECTIVES: Literature is emerging regarding the role of center volume as an independent variable contributing to improved outcomes. A higher volume of index procedures may be associated with decreased morbidity and mortality. This association has not been examined for the subgroup of infants with congenital diaphragmatic hernia (CDH) receiving extracorporeal life support (ECLS). Our study aims to examine the risk-adjusted association between center volume and outcomes in CDH-ECLS neonates, hypothesizing that higher center volume confers a survival advantage. DESIGN: Multicenter, retrospective comparative study using the Extracorporeal Life Support Organization database. SETTING: One hundred twenty international pediatric centers. PATIENTS: Neonates with CDH managed with ECLS from 2000 to 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The cohort included 4,985 neonates with a mortality rate of 50.6%. For the 120 centers studied, mean center volume was 42.4 ± 34.6 CDH ECLS cases over the 20-year study period. In an adjusted model, higher ECLS volume was associated with lower odds of mortality: odds ratio (OR) 0.995 (95% CI, 0.992-0.999; p = 0.014). For an increase in one sd in volume, that is, 1.75 cases annually, the OR for mortality was lower by 16.7%. Volume was examined as a categorical exposure variable where low-volume centers (fewer than 2 cases/yr) were associated with 54% higher odds of mortality (OR, 1.54; 95% CI, 1.03-2.29) compared with high-volume centers. On-ECLS complications (mechanical, neurologic, cardiac, hematologic metabolic, and renal) were not associated with volume. The likelihood of infectious complications was higher for low- (OR, 1.90; 95% CI, 1.06-3.40) and medium-volume (OR, 1.87; 95% CI, 1.03-3.39) compared with high-volume centers. CONCLUSIONS: In this study, a survival advantage directly proportional to center volume was observed for CDH patients managed with ECLS. There was no significant difference in most complication rates. Future studies should aim to identify factors contributing to the higher mortality and morbidity observed at low-volume centers.

A Novel VACTERL Assessment Tool to Facilitate Counseling for Expectant Families.

INTRODUCTION: VACTERL is defined as 3 or more of the following congenital defects: vertebral, anorectal, cardiac, tracheoesophageal (TE), renal, and limb. The purpose of this study was to create an easy-to-use assessment tool to help providers counsel expecting families regarding the likelihood of additional anomalies and postnatal outcomes. METHODS: Employing the Kids' Inpatient Database from 2003-2016, neonates (<29 days old) with VACTERL were identified using ICD-9-CM and ICD-10-CM codes. For each unique combination of VACTERL, multivariable logistic regression was used to estimate inpatient mortality, and Poisson regression was used to estimate length-of-stay during the initial hospitalization. RESULTS: The assessment tool used in this study is available at https://choc-trauma.shinyapps.io/VACTERL. 1,886 of 11,813,782 (0.016%) neonates presented with VACTERL. 32% weighed <1,750 g, and 239 (12.7%) died prior to discharge. Associated with mortality were limb anomaly (1.8 [1.01-3.22], p < 0.05), prematurity (1.99 [1.14-3.47], p < 0.02), and weight <1,750 g (2.19 [1.25-3.82], p < 0.01). Median length-of-stay was 14 days (IQR: 7-32). Associated with increased length-of-stay were cardiac defect (1.47 [1.37-1.56], p < 0.001), vertebral anomaly (1.1 [1.05-1.14], p < 0.001), TE fistula (1.73 [1.66-1.81], p < 0.001), anorectal malformation (1.12 [1.07-1.16], p < 0.001), and weight <1,750 g (1.65 [1.57-1.73], p < 0.001). CONCLUSION: This novel assessment tool may help providers counsel families confronting a VACTERL diagnosis.

Multigenerational impacts of EE2 on reproductive fitness and immune competence of marine medaka.

Estrogenic endocrine disrupting chemicals (EEDC) have been suspected to impact offspring in a transgenerational manner via modifications of the germline epigenome in the directly exposed generations. A holistic assessment of the concentration/ exposure duration-response, threshold level, and critical exposure windows (parental gametogenesis and embryogenesis) for the transgenerational evaluation of reproduction and immune compromise concomitantly will inform the overall EEDC exposure risk. We conducted a multigenerational study using the environmental estrogen, 17α-ethinylestradiol (EE2), and the marine laboratory model fish Oryzias melastigma (adult, F0) and their offspring (F1-F4) to identify transgenerationally altered offspring generations and phenotype persistence. Three exposure scenarios were used: short parental exposure, long parental exposure, and a combined parental and embryonic exposure using two concentrations of EE2 (33ng/L, 113ng/L). The reproductive fitness of fish was evaluated by assessing fecundity, fertilization rate, hatching success, and sex ratio. Immune competence was assessed in adults via a host-resistance assay. EE2 exposure during both parental gametogenesis and embryogenesis was found to induce concentration/ exposure duration-dependent transgenerational reproductive effects in the unexposed F4 offspring. Furthermore, embryonic exposure to 113 ng/L EE2 induced feminization of the directly exposed F1 generation, followed by subsequent masculinization of the F2 and F3 generations. A sex difference was found in the transgenerationally impaired reproductive output with F4 females being sensitive to the lowest concentration of EE2 (33 ng/L) upon long-term ancestral parent exposure (21 days). Conversely, F4 males were affected by ancestral embryonic EE2 exposure. No definitive transgenerational impacts on immune competence were identified in male or female offspring. In combination, these results indicate that EEDCs can be transgenerational toxicants that may negatively impact the reproductive success and population sustainability of fish populations.

Single-Droplet Microsensor for Ultra-Short Circulating EFGR Mutation Detection in Lung Cancer Based on Multiplex EFIRM Liquid Biopsy.

Liquid biopsy is a rapidly emerging field that involves the minimal/non-invasive assessment of signature somatic mutations through the analysis of circulating tumor DNA (ctDNA) shed by tumor cells in bodily fluids. Broadly speaking, the unmet need in liquid biopsy lung cancer detection is the lack of a multiplex platform that can detect a mutation panel of lung cancer genes using a minimum amount of sample, especially for ultra-short ctDNA (usctDNA). Here, we developed a non-PCR and non-NGS-based single-droplet-based multiplexing microsensor technology, "Electric-Field-Induced Released and Measurement (EFIRM) Liquid Biopsy" (m-eLB), for lung cancer-associated usctDNA. The m-eLB provides a multiplexable assessment of usctDNA within a single droplet of biofluid in only one well of micro-electrodes, as each electrode is coated with different probes for the ctDNA. This m-eLB prototype demonstrates accuracy for three tyrosine-kinase-inhibitor-related EGFR target sequences in synthetic nucleotides. The accuracy of the multiplexing assay has an area under the curve (AUC) of 0.98 for L858R, 0.94 for Ex19 deletion, and 0.93 for T790M. In combination, the 3 EGFR assay has an AUC of 0.97 for the multiplexing assay.

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia.

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression towards severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.

A pilot study of multi-modal pain management for same-day discharge after minimally invasive repair of pectus excavatum (Nuss procedure) in children.

BACKGROUND: Despite advancements in minimally invasive repair of pectus excavatum (MIRPE), Nuss procedure, postoperative pain control remains challenging. This report covers a multimodal regimen using bilateral single-shot paravertebral block (PVB) and bilateral thoracoscopic intercostal nerve (T3-T7) cryoablation, leading to significant reduction in length of stay (LOS) and high rate of same-day discharge. METHODS: This is a comparative study of pain management protocols for patients undergoing the Nuss procedure at a single center from 2016 through 2020. All patients underwent the the same surgical technique for the treatment of pectus excavatum at a single center. Patients received bilateral PVB with continuous infusion (Group 1, n = 12), bilateral PVB with infusion and right-side cryoablation (Group 2, n = 9), or bilateral single-shot PVB and bilateral cryoablation (Group 3, n = 17). The primary outcome was LOS with focus on same-day discharge, and the secondary outcome was decreased opioid usage. RESULTS: Eleven of 17 patients in Group 3 (65%) (bilateral single-shot PVB and bilateral cryoablation) were discharged the same day as surgery. The remaining Group 3 patients were discharged the following day with no complications or interventions. Compared to Group 1 (no cryoablation), Group 3 had shorter LOS (median 4.4 days vs. 0.7 days, respectively, p < 0.001) and significantly decreased median opioid use on the day of surgery (0.92 mg/kg vs. 0.47 mg/kg, p = 0.006). CONCLUSION: Findings demonstrate the feasibility of multimodal pain management for same-day discharge after the Nuss procedure. Future multisite studies are needed to investigate the superiority of this approach to established methods. LEVEL OF EVIDENCE: III.

Single-center comparison of outcomes between laparoscopic appendectomy and transumbilical laparoscopic assisted appendectomy.

PURPOSE: Appendectomy is the most common pediatric emergency surgery performed to date. This study compared outcomes between laparoscopic appendectomy (LA) and transumbilical laparoscopic assisted appendectomy (TULAA) for 1154 uncomplicated patients across 5 years at a single institution. Primary outcomes include length of stay (LOS), post-operative complications, pain score, and operating room (OR) time. METHODS: Demographic and clinical data was collected for 1154 eligible patients treated for uncomplicated appendicitis between August 2014-October 2019, with 830 patients in the LA group, and 324 in the TULAA group. Mixed effects modeling procedure using logistic and linear regression examined the effect of surgery type on the four primary outcomes after adjustment for potential clustering effect of surgeon and confounding factors. RESULTS: Of 1154 patients, 62.7% were male, and mean (SD) age was 10.9 (3.6) years. Median [IQR] LOS was 28.0 h [22.0, 36.0], mean (SD) OR time was 29.0 (10.0) minutes, and median [IQR] pain at maximum level was 5.5 (2.7). The complication rate overall was <5.0% and did not differ between TULAA and LA groups (p > 0.05). OR time was reduced by an average of 5.2 min in the TULAA group (p < 0.001), pain did not differ between groups overall (p > 0.05), and patients were more likely to be discharged within 24 h in patients who underwent TULAA (OR = 5.3 [1.6, 17.4], p = 0.007). CONCLUSION: Retrospective analysis of 1154 pediatric appendectomies, found no difference in complications between single- and three-incision laparoscopic procedures (TULAA vs. LA). Findings suggest TULAA is a safe procedure for acute appendicitis in pediatrics. LEVEL OF EVIDENCE: IV.

Application of a Machine Learning Method for Prediction of Urban Neighborhood-Scale Air Pollution.

Urban air pollution has aroused growing attention due to its associated adverse health effects. A model which could promptly predict urban air quality with considerable accuracy is, therefore, important and will benefit the development of smart cities. However, only a computational fluid dynamics (CFD) model could better resolve the dispersion behavior within an urban canyon layer. A machine learning (ML) model using the Artificial Neural Network (ANN) approach was formulated in the current study to investigate vehicle-derived airborne particulate (PM10) dispersion within a compact high-rise-built environment. Various measured meteorological parameters and PM10 concentrations were adopted as the model inputs to train the ANN model. A building-resolved CFD model under the same environmental settings was also set up to compare its model performance with the ANN model. Our results showed that the ANN model exhibited promising performance (r = 0.82, fractional bias = 0.002) when comparing the > 1000 h PM10 measurements. When comparing the diurnal hourly measured PM10 variations in a clear-sky day, both the ANN and CFD models performed well (r > 0.8). The good performance of the CFD model relied on the knowledge of the in situ diurnal traffic profile, the adoption of suitable mobile source emission factor(s) (e.g., from MOBILE 6 and COPERT4), and the use of urban thermal and dynamical variables to capture PM10 variations in both neutral and unstable atmospheric conditions. These requirements/constraints make it impractical for daily operation. On the contrary, the ML (ANN) model adopted here is free from these constraints and is fast (less than 0.1% computational time relative to the CFD model). These results demonstrate that the ANN model is a superior option for a smart city application.