Spectroscopic and Microscopic Characterization of Microbial Biofouling on Aircraft Fuel Tanks.

Avoiding microbial contamination and biofilm formation on the surfaces of aircraft fuel tanks is a major challenge in the aviation industry. The inevitable presence of water in fuel systems and nutrients provided by the fuel makes an ideal environment for bacteria, fungi, and yeast to grow. Understanding how microbes grow on different fuel tank materials is the first step to control biofilm formation in aviation fuel systems. In this study, biofilms of Pseudomonas putida, a model Gram-negative bacterium previously found in aircraft fuel tanks, were characterized on aluminum 7075-T6 surfaces, which is an alloy used by the aviation industry due to favorable properties including high strength and fatigue resistance. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray (EDX) showed that extracellular polymeric substances (EPS) produced by P. putida were important components of biofilms with a likely role in biofilm stability and adhesion to the surfaces. EDX analysis showed that the proportion of phosphorus with respect to nitrogen is higher in the EPS than in the bacterial cells. Additionally, different morphologies in biofilm formation were observed in the fuel phase compared to the water phase. Micro-Fourier transform infrared spectroscopy (micro-FTIR) analysis suggested that phosphoryl and carboxyl functional groups are fundamental for the irreversible attachment between the EPS of bacteria and the aluminum surface, by the formation of hydrogen bonds and inner-sphere complexes between the macromolecules and the aluminum surface. Based on the hypothesis that nucleic acids (particularly DNA) are an important component of EPS in P. putida biofilms, the impact of degrading extracellular DNA was tested. Treatment with the enzyme DNase I affected both water and fuel phase biofilms─with the cell structure disrupted in the aqueous phase, but cells remained attached to the aluminum coupons.

Educational Strategies in Pediatric Trauma Resuscitation Across Disciplines: A Scoping Review.

INTRODUCTION: Trauma is the leading cause of death and disability in children. Differences in mechanism, injury pattern, severity, and physiology in this population distinguish pediatric trauma patients from adults. Educational techniques including simulation and didactics may improve pediatric readiness in this setting. We summarize the literature across disciplines, highlighting the curricular approaches, target provider population, educational content, content delivery method, and Kirkpatrick level for pediatric trauma resuscitation education. METHODS: The MEDLINE (via Ovid), Embase (via Elsevier), Cumulative Index to Nursing & Allied Health Literature Complete (via EBSCO), Education Database (via ProQuest), and Web of Science Social Science Citation Index and Science Citation Index (via Clarivate) were searched. We reviewed 90 manuscripts describing pediatric trauma resuscitation education programs. When available, target provider population, curricular content, delivery method, and Kirkpatrick level were obtained. RESULTS: Nurses (50%), residents (45%), and attending physicians (43%) were the most common participants. Airway management (25%), shock (25%), and general trauma (25%) were the most frequently taught concepts, and delivery of content was more frequently via simulation (65%) or didactics (52%). Most studies (39%) were Kirkpatrick Level 1. CONCLUSIONS: This review suggests that diverse strategies exist to promote pediatric readiness. Most training programs are interdisciplinary and use a variety of educational techniques. However, studies infrequently report examining the impact of educational interventions on patient-centered outcomes and lack detail in describing their curriculum. Future educational efforts would benefit from heightened attention to such outcome measures and a rigorous description of their curricula to allow for reproducibility.

A National Comparison of Volume and Acuity for Adult and Pediatric Trauma: A Trauma Quality Improvement Program Cohort Study.

INTRODUCTION: Most injured children receive trauma care outside of a pediatric trauma center. Differences in physiology, dosing, and injury pattern limit extrapolation of adult trauma principles to pediatrics. We compare US trauma center experience with pediatric and adult trauma resuscitation. MATERIALS AND METHODS: We queried the 2019 Trauma Quality Improvement Program to describe the experience of US trauma centers with pediatric (<15 y) and adult trauma. We quantified blunt, penetrating, burn, and unspecified traumas and compared minor, moderate, severe, and critical traumas (ISS 1-8 Minor, ISS 9-14 Moderate, ISS 15-24 Severe, ISS 25+ Critical). We estimated center-level volumes for adults and children. Institutional identifiers were generated based on unique center specific factors including hospital teaching status, hospital type, verification level, pediatric verification level, state designation, state pediatric designation, and bed size. RESULTS: A total of 755,420 adult and 76,449 pediatric patients were treated for traumatic injuries. There were 21 times as many critical or major injuries in adults compared to children, 17 times more moderate injuries, and 6 times more minor injuries. Children and adults presented with similar rates of blunt trauma, but penetrating injuries were more common in adults and burn injuries were more common in children. Comparing center-level data, adult trauma exceeded pediatric for every severity and mechanism. CONCLUSIONS: There is relatively limited exposure to high-acuity pediatric trauma at US centers. Investigation into pediatric trauma resuscitation education and simulation may promote pediatric readiness and lead to improved outcomes.

Improved survival and higher rates of surgical resection associated with hepatocellular carcinoma in children as compared to young adults.

Hepatocellular adenocarcinoma (HCC) is the second most common primary hepatic malignancy in children with a 5-year overall survival of 30%. Few studies have examined the similarities and differences between pediatric and adult HCC. This article aims to examine the relationship between tumor characteristics, treatments and outcomes in pediatric and adult patients with HCC. The 2019 National Cancer Database was queried for patients with HCC. Patients were stratified by age: pediatric <21 years (n = 214) and young adults 21 to 40 (n = 1102). Descriptive statistics and chi square were performed. The mean age at diagnosis was 15.5 years (SD 5.6) in the pediatric and 33 years (5.3) in the adult group. Children had a comparable rate of metastasis (30% vs 28%, P = .47) and increased fibrolamellar histology (32% vs 9%). Surgical resection was more common in children compared to adults (74% vs 62%, P < .001), children also had more lymph nodes examined (39% vs 19%, P < .001), positive lymph nodes (35% vs 17%, P = .02) and surgical resection when metastasis were present at diagnosis (46% vs 18%, P < .001). The 1-, 3- and 5-year overall survival was higher for pediatric patients than adults (81%, 65%, 55%, vs 70%, 54%, 48%). Despite higher prevalence of fibrolamellar histology, greater number of positive lymph nodes and comparable rates of metastasis at diagnosis, children with HCC have improved overall survival compared to adults. Age did not significantly contribute to survivorship, so it is likely that the more aggressive surgical approach contributed to the improved overall survival in pediatric patients.

Comparison of median sternotomy and left anterior mini-incision for pulmonary valve replacement following primary tetralogy of Fallot repair.

OBJECTIVE: Pulmonary insufficiency requiring reintervention frequently occurs after primary tetralogy of Fallot repair. Repeat interventions present a challenge for both the surgeon and patient. We compare a minimally invasive, 5 cm left anterior mini-incision to redo median sternotomy for pulmonary valve replacement in tetralogy of Fallot patients. METHODS: Following Internal Review Board approval, we conducted a single institution retrospective review of patients with tetralogy of Fallot who underwent pulmonary valve replacement via redo median sternotomy or left anterior mini-incision between 13 July, 2016 and 6 March, 2020. RESULTS: Twenty-three patients underwent pulmonary valve replacement following primary tetralogy of Fallot repair between March 2016 and March 2020. Twelve patients received a redo-median sternotomy from March 2016 to August 2018. Left anterior mini-incision was first offered in August of 2018 and was chosen by all eleven patients thereafter. The two groups had similar baseline characteristics including preoperative pulmonary valve dysfunction. Early trends suggest a longer cardiopulmonary bypass time for patients who received left anterior mini-incisions. Other outcomes were comparable, including operative times, blood product requirements, residual pulmonary valve dysfunction, postoperative pain, narcotic requirements, ICU length of stay, total length of stay, and postoperative complications. CONCLUSIONS: In patients who have previously undergone primary repairs of tetralogy of Fallot, outcomes for pulmonary valve replacement via left anterior mini-incision are comparable to those via redo median sternotomy.

Evaluation of the Arabin cervical pessary for prevention of preterm birth in women with a twin pregnancy and short cervix (STOPPIT-2): An open-label randomised trial and updated meta-analysis.

BACKGROUND: Preterm-labour-associated preterm birth is a common cause of perinatal mortality and morbidity in twin pregnancy. We aimed to test the hypothesis that the Arabin pessary would reduce preterm-labour-associated preterm birth by 40% or greater in women with a twin pregnancy and a short cervix. METHODS AND FINDINGS: We conducted an open-label randomised controlled trial in 57 hospital antenatal clinics in the UK and Europe. From 1 April 2015 to 14 February 2019, 2,228 women with a twin pregnancy underwent cervical length screening between 18 weeks 0 days and 20 weeks 6 days of gestation. In total, 503 women with cervical length ≤ 35 mm were randomly assigned to pessary in addition to standard care (n = 250, mean age 32.4 years, mean cervical length 29 mm, with pessary inserted in 230 women [92.0%]) or standard care alone (n = 253, mean age 32.7 years, mean cervical length 30 mm). The pessary was inserted before 21 completed weeks of gestation and removed at between 35 and 36 weeks or before birth if earlier. The primary obstetric outcome, spontaneous onset of labour and birth before 34 weeks 0 days of gestation, was present in 46/250 (18.4%) in the pessary group compared to 52/253 (20.6%) following standard care alone (adjusted odds ratio [aOR] 0.87 [95% CI 0.55-1.38], p = 0.54). The primary neonatal outcome-a composite of any of stillbirth, neonatal death, periventricular leukomalacia, early respiratory morbidity, intraventricular haemorrhage, necrotising enterocolitis, or proven sepsis, from birth to 28 days after the expected date of delivery-was present in 67/500 infants (13.4%) in the pessary group compared to 76/506 (15.0%) following standard care alone (aOR 0.86 [95% CI 0.54-1.36], p = 0.50). The positive and negative likelihood ratios of a short cervix (≤35 mm) to predict preterm birth before 34 weeks were 2.14 and 0.83, respectively. A meta-analysis of data from existing publications (4 studies, 313 women) and from STOPPIT-2 indicated that a cervical pessary does not reduce preterm birth before 34 weeks in women with a short cervix (risk ratio 0.74 [95% CI 0.50-1.11], p = 0.15). No women died in either arm of the study; 4.4% of babies in the Arabin pessary group and 5.5% of babies in the standard treatment group died in utero or in the neonatal period (p = 0.53). Study limitations include lack of power to exclude a smaller than 40% reduction in preterm labour associated preterm birth, and to be conclusive about subgroup analyses. CONCLUSIONS: These results led us to reject our hypothesis that the Arabin pessary would reduce the risk of the primary outcome by 40%. Smaller treatment effects cannot be ruled out. TRIAL REGISTRATION: ISRCTN Registry ISRCTN 02235181. ClinicalTrials.gov NCT02235181.

Randomized Trials of Retosiban Versus Placebo or Atosiban in Spontaneous Preterm Labor.

OBJECTIVE: The aim of this study is to assess the efficacy and safety of retosiban in spontaneous preterm labor (sPTL). STUDY DESIGN: Two multicenter, randomized, and double-blind trials compared retosiban with placebo and retosiban with atosiban in women with a singleton pregnancy and intact membranes in sPTL at 24 to 336/7 weeks' gestation. Coprimary endpoints in the placebo-controlled trial were time to delivery (TTD) or treatment failure (whichever occurred first) and neonatal composite morbidity and mortality. The primary endpoint of the atosiban comparator trial was TTD. RESULTS: The trials were terminated early because of slow recruitment. The placebo-controlled trial enrolled 23 participants (February 2016-July 2017; 2.6% of target);the atosiban-comparator trial enrolled 97 (March 2015-August 2017; 29% of target). Baseline participant characteristics were similar between treatments. In the placebo-controlled trial, mean gestational ages at randomization were 30.8 (retosiban, n = 10) and 30.5 weeks (placebo, n = 13), and mean times to delivery/treatment failure were 18.9 days (retosiban) and 11.1 days (placebo). Two and four neonates in the retosiban and placebo groups, respectively, had ≥1 component of the neonatal composite endpoint. In the atosiban-comparator trial, mean gestational age at randomization was 31.5 weeks (for both retosiban, n = 47, and atosiban, n = 50), and adjusted mean TTDs were 32.51 days (retosiban) and 33.71 days (atosiban; p > 0.05). Adverse events were no more common with retosiban than placebo or atosiban. CONCLUSION: Despite considerable efforts to conduct two adequate and well-controlled studies in patients with sPTL, both studies were unable to recruit effectively and consequently terminated prematurely. Key factors negatively affecting participation were patient and physician resistance to use of a placebo comparator, lack of investigator consensus on diagnostic criteria and acceptance of protocol procedures, and ethics committee decisions. Meaningful cooperation between pharmaceutical companies, regulatory authorities, and the obstetric community is essential for future development of drugs to treat sPTL.

MAVRIC: a multicenter randomized controlled trial of transabdominal vs transvaginal cervical cerclage.

BACKGROUND: Vaginal cerclage (a suture around the cervix) commonly is placed in women with recurrent pregnancy loss. These women may experience late miscarriage or extreme preterm delivery, despite being treated with cerclage. Transabdominal cerclage has been advocated after failed cerclage, although its efficacy is unproved by randomized controlled trial. OBJECTIVE: The objective of this study was to compare transabdominal cerclage or high vaginal cerclage with low vaginal cerclage in women with a history of failed cerclage. Our primary outcome was delivery at <32 completed weeks of pregnancy. STUDY DESIGN: This was a multicenter randomized controlled trial. Women were assigned randomly (1:1:1) to receive transabdominal cerclage, high vaginal cerclage, or low vaginal cerclage either before conception or at <14 weeks of gestation. RESULTS: The data for 111 of 139 women who were recruited and who conceived were analyzed: 39 had transabdominal cerclage; 39 had high vaginal cerclage, and 33 had low vaginal cerclage. Rates of preterm birth at <32 weeks of gestation were significantly lower in women who received transabdominal cerclage compared with low vaginal cerclage (8% [3/39] vs 33% [11/33]; relative risk, 0.23; 95% confidence interval, 0.07-0.76; P=.0157). The number needed to treat to prevent 1 preterm birth was 3.9 (95% confidence interval, 2.32-12.1). There was no difference in preterm birth rates between high and low vaginal cerclage (38% [15/39] vs 33% [11/33]; relative risk, 1.15; 95% confidence interval, 0.62-2.16; P=.81). No neonatal deaths occurred. In an exploratory analysis, women with transabdominal cerclage had fewer fetal losses compared with low vaginal cerclage (3% [1/39] vs 21% [7/33]; relative risk, 0.12; 95% confidence interval, 0.016-0.93; P=.02). The number needed to treat to prevent 1 fetal loss was 5.3 (95% confidence interval, 2.9-26). CONCLUSION: Transabdominal cerclage is the treatment of choice for women with failed vaginal cerclage. It is superior to low vaginal cerclage in the reduction of risk of early preterm birth and fetal loss in women with previous failed vaginal cerclage. High vaginal cerclage does not confer this benefit. The numbers needed to treat are sufficiently low to justify transabdominal surgery and cesarean delivery required in this select cohort.

Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial.

BACKGROUND: Progesterone administration has been shown to reduce the risk of preterm birth and neonatal morbidity in women at high risk, but there is uncertainty about longer term effects on the child. METHODS: We did a double-blind, randomised, placebo-controlled trial of vaginal progesterone, 200 mg daily taken from 22-24 to 34 weeks of gestation, on pregnancy and infant outcomes in women at risk of preterm birth (because of previous spontaneous birth at ≤34 weeks and 0 days of gestation, or a cervical length ≤25 mm, or because of a positive fetal fibronectin test combined with other clinical risk factors for preterm birth [any one of a history in a previous pregnancy of preterm birth, second trimester loss, preterm premature fetal membrane rupture, or a history of a cervical procedure to treat abnormal smears]). The objective of the study was to determine whether vaginal progesterone prophylaxis given to reduce the risk of preterm birth affects neonatal and childhood outcomes. We defined three primary outcomes: fetal death or birth before 34 weeks and 0 days gestation (obstetric), a composite of death, brain injury, or bronchopulmonary dysplasia (neonatal), and a standardised cognitive score at 2 years of age (childhood), imputing values for deaths. Randomisation was done through a web portal, with participants, investigators, and others involved in giving the intervention, assessing outcomes, or analysing data masked to treatment allocation until the end of the study. Analysis was by intention to treat. This trial is registered at ISRCTN.com, number ISRCTN14568373. FINDINGS: Between Feb 2, 2009, and April 12, 2013, we randomly assigned 1228 women to the placebo group (n=610) and the progesterone group (n=618). In the placebo group, data from 597, 587, and 439 women or babies were available for analysis of obstetric, neonatal, and childhood outcomes, respectively; in the progesterone group the corresponding numbers were 600, 589, and 430. After correction for multiple outcomes, progesterone had no significant effect on the primary obstetric outcome (odds ratio adjusted for multiple comparisons [OR] 0·86, 95% CI 0·61-1·22) or neonatal outcome (OR 0·62, 0·38-1·03), nor on the childhood outcome (cognitive score, progesterone group vs placebo group, 97·3 [SD 17·9] vs 97·7 [17·5]; difference in means -0·48, 95% CI -2·77 to 1·81). Maternal or child serious adverse events were reported in 70 (11%) of 610 patients in the placebo group and 59 (10%) of 616 patients in the progesterone group (p=0·27). INTERPRETATION: Vaginal progesterone was not associated with reduced risk of preterm birth or composite neonatal adverse outcomes, and had no long-term benefit or harm on outcomes in children at 2 years of age. FUNDING: Efficacy and Mechanism Evaluation (EME) Programme, a Medical Research Council (MRC) and National Institute for Health Research (NIHR) partnership. The EME Programme is funded by the MRC and NIHR, with contributions from the Chief Scientist Office in Scotland and National Institute for Social Care and Research in Wales.

Treatment of spontaneous preterm labour with retosiban: a phase II pilot dose-ranging study.

AIMS: The aims of the present study were to investigate the maternal, fetal and neonatal safety and tolerability, pharmacodynamics and pharmacokinetics of intravenous (IV) retosiban in pregnant women with spontaneous preterm labour (PTL) between 340/7 and 356/7  weeks' gestation. METHODS: In parts A and B of a three-part, double-blind, placebo-controlled, multicentre study, women were randomized 3:1 (Part A) or 2:1 (Part B) to either 12-h IV retosiban followed by a single dose of oral placebo (R-P) or 12-h IV placebo followed by single-dose oral retosiban (P-R). RESULTS: A total of 29 women were randomized; 20 to R-P and nine to P-R. An integrated analysis found that adverse events were infrequent in mothers/newborns and consistent with events expected in the population under study or associated with confounding factors. Retosiban was rapidly absorbed after oral administration, with an observed half-life of 1.45 h. Efficacy analyses included 19 women. While not statistically significant, those receiving R-P more frequently achieved uterine quiescence in 6 h (R-P, 63%; 95% credible interval [CrI]: 38, 84; P-R, 43%; 95% CrI: 12, 78) and more achieved a reduction of ≥50% in uterine contractions in 6 h (R-P, 63%; 95% CrI: 38, 84; P-R, 29%; 95% CrI: 4, 64). The number of days to delivery was increased in women receiving R-P (median 26 days for R-P vs. 13 days for P-R). CONCLUSIONS: Intravenous retosiban has a favourable safety and tolerability profile and might prolong pregnancies in women with PTL. The study provides the rationale and dosing strategy for further evaluation of the efficacy of retosiban in the treatment of PTL.

The influence of air-filled structures on wave propagation and beam formation of a pygmy sperm whale (Kogia breviceps) in horizontal and vertical planes.

The wave propagation, sound field, and transmission beam pattern of a pygmy sperm whale (Kogia breviceps) were investigated in both the horizontal and vertical planes. Results suggested that the signals obtained at both planes were similarly characterized with a high peak frequency and a relatively narrow bandwidth, close to the ones recorded from live animals. The sound beam measured outside the head in the vertical plane was narrower than that of the horizontal one. Cases with different combinations of air-filled structures in both planes were used to study the respective roles in controlling wave propagation and beam formation. The wave propagations and beam patterns in the horizontal and vertical planes elucidated the important reflection effect of the spermaceti and vocal chambers on sound waves, which was highly significant in forming intensive forward sound beams. The air-filled structures, the forehead soft tissues and skull structures formed wave guides in these two planes for emitted sounds to propagate forward.

Holistic Evaluation of Field-Scale Denitrifying Bioreactors as a Basis to Improve Environmental Sustainability.

Denitrifying bioreactors convert nitrate-nitrogen (NO-N) to di-nitrogen and protect water quality. Herein, the performance of a pilot-scale bioreactor (10 m long, 5 m wide, 2 m deep) containing seven alternating cells filled with either sandy loam soil or lodgepole pine woodchip and with a novel "zig-zag" flow pattern was investigated. The influent water had an average NO-N concentration of 25 mg L. The performance of the bioreactor was evaluated in two scenarios. In Scenario 1, only NO-N removal was evaluated; in Scenario 2, NO-N removal, ammonium-N (NH-N), and dissolved reactive phosphorus (DRP) generation was considered. These data were used to generate a sustainability index (SI), which evaluated the overall performance taking these parameters into account. In Scenario 1, the bioreactor was a net reducer of contaminants, but it transformed into a net producer of contaminants in Scenario 2. Inquisition of the data using these scenarios meant that an optimum bioreactor design could be identified. This would involve reduction to two cells: a single sandy loam soil cell followed by a woodchip cell, which would remove NO-N and reduce greenhouse gas (GHG) emissions and DRP losses. An additional post-bed chamber containing media to eliminate NH-N and surface capping to reduce GHG emissions further is advised. Scenario modeling, such as that proposed in this paper, should ideally include GHG in the SI, but because different countries have different emission targets, future work should concentrate on the development of geographically appropriate weightings to facilitate the incorporation of GHG into a SI.

Treatment of spontaneous preterm labour with retosiban: a phase 2 proof-of-concept study.

AIM: The aim was to investigate the efficacy and safety of intravenous retosiban in women with spontaneous preterm labour. METHODS: This was a randomized, double-blind, placebo-controlled, phase 2 trial. Retosiban was administered intravenously for 48 h to women in spontaneous preterm labour between 30(0/7) and 35(6/7) weeks' gestation with an uncomplicated singleton pregnancy in an in-patient obstetric unit. Outcome measures were uterine quiescence (primary endpoint), days to delivery, preterm delivery and safety. RESULTS: Uterine quiescence was achieved in 62% of women who received retosiban (n = 30) compared with 41% who received placebo (n = 34). The relative risk (RR) was 1.53 (95% credible interval [CrI] 0.98, 2.48; NS). Retosiban resulted in a significant increase in time to delivery compared with placebo (mean difference 8.2 days, 95% CrI 2.7, 13.74). This difference was consistent across all gestational ages. The proportion of preterm births in the retosiban and placebo groups was 18.7% (95% CrI 7.4%, 33.7%) and 47.2% (95% CrI 31.4%, 63.4%), respectively. The RR of preterm birth in women treated with retosiban was 0.38 (95% CrI 0.15, 0.81). There were no deliveries within 7 days in the retosiban group, but there were six (17.6%) births in the placebo group. The maternal, fetal and neonatal adverse events were comparable in the retosiban and placebo groups. CONCLUSIONS: Intravenous administration of retosiban in women with spontaneous preterm labour was associated with a greater than 1 week increase in time to delivery compared with placebo, a significant reduction in preterm deliveries, a non-significant increase in uterine quiescence and a favourable safety profile.

Late preterm birth is associated with short-term morbidity but not with adverse neurodevelopmental and physical outcomes at 1 year.

We compared the neonatal and infant outcomes at one year (Bayley mental and psychomotor development index, and physical growth) of babies who were (n = 63) or were not (n = 100) delivered prior to 37 weeks in women admitted in threatened late preterm labor (34-35(+6) weeks) with a cervix ≤15 mm. The women were part of a clinical trial to investigate the tocolytic effect of the oxytocin antagonist barusiban. Babies born late preterm (34-36(+6) weeks) had a significantly increased risk of short-term morbidity (hepatobiliary disorders, respiratory disorders, metabolic disorders, nervous system disorders, infection; p < 0.05 for each) compared with those born at term, but there were no significant differences in the neurodevelopmental and physical outcomes at one year (p > 0.05 for both one-year outcomes).

Enhancing in situ biodegradation in groundwater using pump and treat remediation: a proof of concept and modelling analysis of controlling variables.

A remediation approach which uses pump and treatment (PAT) to enhance the biodegradation of organic contaminants by increasing dispersive mixing between plumes and groundwater was evaluated for a phenol-contaminated aquifer, using a reactive transport model which simulates kinetic reactions between an electron donor (ED) in the plume and electron acceptor (EA) in the groundwater. The influence of system design and operation was examined in six modelling scenarios. Injection or extraction of groundwater increases biodegradation above no action and the location, pumping rate, and distance between well(s) are important variables which influence biodegradation. An increase in pumping rate, distance of the wells from the plume centreline, and changing the flow direction increase dispersive mixing between the plume and groundwater. This increases plume spreading and the plume fringe interface, providing a greater flux of dissolved EAs for biodegradation. In general, injection of groundwater containing natural EAs enhances biodegradation more than extraction. The enhancement of biodegradation is sensitive to the relative fluxes of ED and EA, as controlled by the arrangement of the wells. In the best performing scenario, biodegradation was enhanced by 128%, compared with no action.

Longitudinal Integrated Clerkships and Undergraduate Surgical Education: A Scoping Review and Gap Analysis.

OBJECTIVE: Longitudinal integrated clerkships (LICs) are an increasingly popular approach to medical student clinical education, and the literature describing them is expanding. Despite this, there is a lack of understanding for how surgery didactics and skills are currently taught as a part of the LIC curriculum. DESIGN: We conducted a scoping literature review in July 2022 using terms related to LIC and surgical education. Abstract and full-length text screening followed. Data extraction was completed in August 2022. Articles published in English, focused on LIC students, and discussed any element of LIC curriculum surgical education was included. SETTING: Scoping literature review. PARTICIPANTS: A total of 282 studies describing LICs were identified from the scoping literature review. After applying inclusion and exclusion criteria, 37 (13%) studies describing some element of surgical education were included. RESULTS: Of these 37 studies, the majority did not delve into pertinent details related to students' surgery experience, expectations, and surgical skills accomplishments. Four studies (11%) reported on the outpatient surgical experience, such as minimum required time that students were expected to be in the clinic, and 8 studies (22%) described the inpatient and operating room exposure. Only 1 study (3%) described the surgical floor management of surgical patients, including tasks like documentation and wound care, and 3 studies (8%) reported formal assessment of surgical skills, such as suturing technique. CONCLUSIONS: Our study highlights the paucity LIC literature examining the relationship between this curricular innovation and the unique needs of medical students on a surgical clerkship. Surgeon educators should embrace the opportunity to contribute LIC curriculum development and subsequent investigation into how this modality interfaces with the learning objectives of undergraduate surgical education. A formal description of essential curriculum components for all surgical LIC programs is needed to ensure appropriate surgical education across the varied LIC models.

Quality improvement initiative to increase radial artery usage as a second arterial conduit in coronary artery bypass grafting.

OBJECTIVES: Use of radial artery as a second arterial graft, compared to a saphenous vein, in coronary artery bypass grafting (CABG) can improve late outcomes. However, the radial artery remains underutilized. We initiated a quality improvement (QI) initiative to increase the usage of radial artery grafts. METHODS: During our 4-month lead period, we disseminated evidence for radial artery graft usage to surgeons, developed a radial artery decision-making algorithm and adopted endoscopic harvesting. Our QI initiative was conducted over a 6-month period and included a postoperative survey of decision-making for graft selection and obstacles to radial artery usage. RESULTS: Over the 6-month study period, 247 patients received isolated CABG which included 98 (40%) with radial arteries as a second arterial graft and 144 (58%) with greater saphenous veins. Radial artery usage increased with QI initiative implementation by 67% compared to 6 months prior to the study period (60 radial arteries/252 isolated CABG, 24%) (P = 0.006). The survey response rate was 93% (231/247). Barriers to radial artery graft usage were poor quality target vessel or stenosis <80% (24%), patient age >75 years (20%), ejection fraction ≤35% (8%) and renal insufficiency/dialysis (7%). No patients experienced significant complications from radial artery harvest. CONCLUSIONS: Our institutional QI initiative was successful in (i) increasing the usage of radial artery as a second arterial graft and (ii) understanding barriers to radial artery graft usage. Implementation of a QI program can improve radial artery usage in CABG with low risk of patient morbidity from radial artery harvest.

Roles, Responsibilities, and Expectations of Medical Students on Surgical Subinternships: A Modified Delphi Consensus Study.

PURPOSE: Surgical subinternships are important rotations for students preparing for a career in general surgery; however, these rotations often vary by institution and service. This modified Delphi study was conducted to reach a consensus set of roles, responsibilities, and expectations of fourth-year medical students on their surgical subinternships. METHOD: Candidate statements on roles, responsibilities, and expectations of subinterns were categorized into 7 domains: rotation structure, rounding and patient care, operating room conduct, technical skills, knowledge base, clinic, and professionalism. Expert panels were assembled of key stakeholders: program directors, clerkship directors, other education faculty, trainees, and recent subinterns. Three Delphi rounds were conducted from January to April 2023 to reach consensus defined a priori as a Cronbach α ≥ 0.8 and 80% or greater panel agreement. RESULTS: Forty-six expert panelists were recruited to participate in Delphi rounds, with 100%, 95.7%, and 97.8% response rates in the first, second, and third rounds, respectively. By the third round, 67 statements reached consensus as essential roles, responsibilities, and expectations of surgical subinterns. Key themes from these 67 statements included subinterns approximating the role of an intern with respect to work hours, patient care responsibilities, basic technical skills, and knowledge base. Panelists rated rounding and patient care as the most important domain, followed closely by professionalism. Additional key domains for evaluation in descending order were knowledge base, operating room conduct, clinic, and technical skills. By the third round, notable disagreements in the Delphi process included technical skills and rounding and patient care (93.3% and 88.9% agreement, respectively). CONCLUSIONS: This study provides a national consensus on core roles, responsibilities, and expectations for medical students completing surgical subinternships. Students can use these recommendations to prepare for subinternships, whereas faculty as well as residents and fellows can use them to evaluate applicants for general surgery residency positions.

Potential of stable isotope analysis to deduce anaerobic biodegradation of ethyl tert-butyl ether (ETBE) and tert-butyl alcohol (TBA) in groundwater: a review.

Understanding anaerobic biodegradation of ether oxygenates beyond MTBE in groundwater is important, given that it is replaced by ETBE as a gasoline additive in several regions. The lack of studies demonstrating anaerobic biodegradation of ETBE, and its product TBA, reflects the relative resistance of ethers and alcohols with a tertiary carbon atom to enzymatic attack under anoxic conditions. Anaerobic ETBE- or TBA-degrading microorganisms have not been characterized. Only one field study suggested anaerobic ETBE biodegradation. Anaerobic (co)metabolism of ETBE or TBA was reported in anoxic microcosms, indicating their biodegradation potential in anoxic groundwater systems. Non-isotopic methods, such as the detection of contaminant loss, metabolites, or ETBE- and TBA-degrading bacteria are not sufficiently sensitive to track anaerobic biodegradation in situ. Compound- and position-specific stable isotope analysis provides a means to study MTBE biodegradation, but isotopic fractionation of ETBE has only been studied with a few aerobic bacteria (εC -0.7 to -1.7‰, εH -11 to -73‰) and at one anoxic field site (δ2H-ETBE +14‰). Similarly, stable carbon isotope enrichment (δ13C-TBA +6.5‰) indicated TBA biodegradation at an anoxic field site. CSIA and PSIA are promising methods to detect anaerobic ETBE and TBA biodegradation but need to be investigated further to assess their full potential at field scale.