Inelastic effects in bulge formation of inflated polymer tubes.

When a soft tube is inflated, it may sometimes show a bulge instability wherein a portion of the tube inflates much more than the rest. The bulge instability is well-understood for hyperelastic materials. We examine inflation of polyurethane tubes whose material behavior is not strictly hyperelastic. Upon inflating at constant rate, the tubes deform into a variety of shapes including irregular axisymmetric shapes with multiple localized bulges, a single axially-propagating bulge, or homogeneous cylindrical shapes. In all cases regardless of the inflation mode, the pressure first rises to a maximum, and then gradually reduces towards a plateau. We document numerous differences as compared to hyperelastic tubes. Most notably a pressure maximum can appear even without bulging, whereas for hyperelastic tubes, a pressure maximum is necessarily accompanied by bulging. Further, the decrease in pressure beyond the maximum occurs gradually over timescales as long as an hour, whereas bulging of hyperelastic tubes induces an instantaneous drop in pressure. We also observe permanent deformation upon deflation, a decrease in the pressure maximum during a subsequent second inflation, and more severe bulge localization at low inflation rates. Existing theory of hyperelastic tube inflation cannot capture the observed behaviors, even qualitatively. Finite element simulations suggest that many of the observations can be explained by viscoelasticity, specifically that a slow material response allows the pressure to remain high for long durations, which in turn allows growth of multiple bulges.

A New Tool for Probabilistic Assessment of MPS Data Associated with mtDNA Mixtures.

Mitochondrial (mt) DNA plays an important role in the fields of forensic and clinical genetics, molecular anthropology, and population genetics, with mixture interpretation being of particular interest in medical and forensic genetics. The high copy number, haploid state (only a single haplotype contributed per individual), high mutation rate, and well-known phylogeny of mtDNA, makes it an attractive marker for mixture deconvolution in damaged and low quantity samples of all types. Given the desire to deconvolute mtDNA mixtures, the goals of this study were to (1) create a new software, MixtureAceMT™, to deconvolute mtDNA mixtures by assessing and combining two existing software tools, MixtureAce™ and Mixemt, (2) create a dataset of in-silico MPS mixtures from whole mitogenome haplotypes representing a diverse set of population groups, and consisting of two and three contributors at different dilution ratios, and (3) since amplicon targeted sequencing is desirable, and is a commonly used approach in forensic laboratories, create biological mixture data associated with two amplification kits: PowerSeq™ Whole Genome Mito (Promega™, Madison, WI, USA) and Precision ID mtDNA Whole Genome Panel (Thermo Fisher Scientific by AB™, Waltham, MA, USA) to further validate the software for use in forensic laboratories. MixtureAceMT™ provides a user-friendly interface while reducing confounding features such as NUMTs and noise, reducing traditionally prohibitive processing times. The new software was able to detect the correct contributing haplogroups and closely estimate contributor proportions in sequencing data generated from small amplicons for mixtures with minor contributions of ≥5%. A challenge of mixture deconvolution using small amplicon sequencing is the potential generation of spurious haplogroups resulting from private mutations that differ from Phylotree. MixtureAceMT™ was able to resolve these additional haplogroups by including known haplotype/s in the evaluation. In addition, for some samples, the inclusion of known haplotypes was also able to resolve trace contributors (minor contribution 1-2%), which remain challenging to resolve even with deep sequencing.

Protected Time for Program Administration among Nephrology Program Leadership in the United States.

BACKGROUND: In 2022, the Accreditation Council for Graduate Medical Education reduced minimum program director protected time for program administration from 10 to 8 h/wk, with no core faculty requirement. We surveyed program leaders regarding the effect of these changes. METHODS: This is an anonymous, online survey of all US adult nephrology program directors (March 2023), who forwarded core faculty/associate program director (APD) surveys. The questions included protected time in 2022-2023 and 2021-2022, whether it was sufficient, estimated time needed, and two validated single-item burnout measures (emotional exhaustion and depersonalization). The analysis was descriptive. RESULTS: Program directors: Their response was 62% (92/149), with geographic distribution/approved fellow positions similar to those nationally. Overall, protected time slightly increased from 2021 to 2022, largely in >6-fellow programs, but 42% (13/31) of these were still not meeting minimum requirements. Only 37% (30/81) agreed that they had sufficient protected time. Those with ≤6 fellows estimated needing 11±4 h/wk (15±4 h/wk with >6 fellows). Twenty-five percent (20/81) reported high levels of emotional exhaustion. Core faculty: 57 of 149 program directors (38%) forwarded the link to 454 faculty. Ninety-four percent of APDs (49/52) responded, reported 3±3 h/wk protected time (42% had none), and estimated needing 6±3 h/wk, regardless of program size. Sixty-seven of 402 core faculty (17%) responded, reported 2±3 h/wk (50% had none), and estimated needing 5±3 h/wk, regardless of program size. ≥85% of APDs and core faculty precepted clinical rotations, gave lectures, evaluated fellows, mentored scholarly work, and participated in recruitment. The majority assisted in fellow remediation. Thirty-four percent (15/44) of APDs and 21% (13/61) of core faculty reported high levels of emotional exhaustion. CONCLUSIONS: Program leaders estimated minimum necessary program administration times (on the basis of program size) that exceeded the Accreditation Council for Graduate Medical Education requirements. APDs/core faculty contributed substantially to nonclinical training. Thirty-four percent of APDs and 25% of program directors had a high likelihood of burnout.

Effect of on-farm poultry litter composting processes on physicochemical, biological, and toxicological parameters and reduction of antibiotics and antibiotic-resistant Escherichia coli.

Poultry litter is a valuable source of nutrients for crop production, but its use in agriculture can lead to environmental and public health concerns due to the presence of pollutants, antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs). We compared the effect of different on-farm poultry litter composting processes on physicochemical, biological, and toxicological parameters, as well as on the occurrence of antibiotics and resistant Escherichia coli. The composting treatments consisted of passively-aerated piles C:N = 19 (PAC19), mechanically-aerated piles C:N = 19 (MAC19), and mechanically-aerated piles C:N = 30 (MAC30). Poultry litter composting led to a significant reduction of antibiotic residues, enteroparasites and antibiotic resistant E. coli. The conditions of the process, such as extra C source and mechanical aeration influence the quality of the final product. MAC19 is a low-cost effective method to reduce the potential risks associated with poultry litter use in agriculture and produce good quality compost.

Modular Aptamer Switches for the Continuous Optical Detection of Small-Molecule Analytes in Complex Media.

Aptamers are a promising class of affinity reagents because signal transduction mechanisms can be built into the reagent, so that they can directly produce a physically measurable output signal upon target binding. However, endowing the signal transduction functionality into an aptamer remains a trial-and-error process that can compromise its affinity or specificity and typically requires knowledge of the ligand binding domain or its structure. In this work, a design architecture that can convert an existing aptamer into a "reversible aptamer switch" whose kinetic and thermodynamic properties can be tuned without a priori knowledge of the ligand binding domain or its structure is described. Finally, by combining these aptamer switches with evanescent-field-based optical detection hardware that minimizes sample autofluorescence, this study demonstrates the first optical biosensor system that can continuously measure multiple biomarkers (dopamine and cortisol) in complex samples (artificial cerebrospinal fluid and undiluted plasma) with second and subsecond-scale time responses at physiologically relevant concentration ranges.

Outcomes of Injured Patients Before and After the Institution of a Third-Tier Activation at a Level 1 Trauma Center.

BACKGROUND: We hypothesized that the addition of a third-level trauma activation would improve outcomes by formalizing an evaluation process for patients in need of urgent evaluation who did not meet the criteria for full or partial trauma alert activation. METHODS: Admission records for all trauma patients admitted between 2000 and 2021 were obtained. The gamma alert trauma activation was implemented in 2011. A washout period of 6 months was used to account for adjustment to the new protocol. Propensity score matching was performed based on ISS scores, age, injury mechanism, and best-validated comorbidities to create a balanced patient distribution. Patients with missing data were excluded from this study. The association between era and outcomes was determined using logistic and linear regression analyses. RESULTS: The matched cohort was well balanced (SMD <.1, all balanced covariates) and included 18,572 patients. Patients in the gamma alert era had decreased ED dwell time, hospital length of stay, and intensive care unit (ICU) length of stay. Readmission rates and rates of upgrade to ICU status were reduced in the gamma alert era. This era was also associated with lower rates of renal failure, UTI, and pneumonia. There was no significant difference in mortality following implementation of the gamma alert. DISCUSSION: Implementation of the gamma alert was associated with an improvement in ED dwell times, fewer unplanned admissions to the ICU, decreased readmissions, and a reduction in other in-hospital events. We believe that this reflects improved triage of patients to the ICU and more effective care of trauma patients.

What drives outcomes in infants of mothers with congenital heart disease? A mediation analysis.

OBJECTIVE: Infants of mothers with adult congenital heart disease (ACHD) are at increased risk for adverse pregnancy and neonatal outcomes. We aim to identify mediators in the relationship between ACHD and pregnancy and infant outcomes. STUDY DESIGN: Case-control study using linked maternal and infant hospital records. Structural equation modeling was performed to assess for potential mediators of pregnancy and infant outcomes. RESULT: We showed an increased risk of multiple adverse infant and pregnancy outcomes among infants born to mothers with ACHD. Maternal placental syndrome and congestive heart failure were mediators of prematurity. Prematurity and critical congenital heart disease in the infant were mediators of infant outcomes. However, the direct effect of ACHD on outcomes beyond that explained by these mediators remained significant. CONCLUSION: While significant mediators of infant and pregnancy outcomes were identified, there was a large direct effect of maternal ACHD. Further studies should aim to identify more factors that explain these infants' vulnerability.

Physical therapist awareness of diagnostic imaging referral jurisdictional scope of practice: an observational study.

OBJECTIVES: To examine physical therapist awareness and utilization of imaging referral privileges in the United States (US) and how it relates to direct access frequency. METHODS: This study utilized survey data collected in 2020-2021 from US physical therapists. Subjects were asked about imaging referral jurisdictional authority in their state. Responses were analyzed for accuracy and compared to the level of jurisdictional authority and its impact on imaging referral. Analysis of imaging skills performance and imaging referral practices were compared to direct access frequency. RESULTS: Only 42.0% of physical therapists practicing in states that allow imaging referral were aware of this privilege. Those practicing where imaging referral was allowed via state legislation were significantly more likely (p < 0.01) to be aware of this privilege (71.4%) compared to those granted by the state board (25.2%). Those aware of their imaging referral scope were more likely (p < 0.01) to practice imaging referral (44.5%) compared to those who were unaware (3.2%). Direct access frequency was positively associated with imaging skill performance and imaging referral practice (p < 0.01). Doctors of Physical Therapy, residency/fellowship-trained physical therapists, and board-certified physical therapists all reported practicing greater frequency of direct access (p < 0.01). DISCUSSION/CONCLUSION: There is a striking lack of awareness of imaging privileges among physical therapists as influenced by the level of jurisdictional scope. These results suggest that the lack of awareness may have a dampening effect on diagnostic imaging referrals. The American Physical Therapy Association should consider engaging with state boards to raise imaging privilege awareness.

Predictors of ECG Interpretation Proficiency in Healthcare Professionals.

Accurate ECG interpretation is vital, but variations in skills exist among healthcare professionals. This study aims to identify factors contributing to ECG interpretation proficiency. Survey data and ECG interpretation test scores from participants in the EDUCATE Trial were analyzed to identify predictors of performance for 30 sequential 12-lead ECGs. Nonmodifiable factors (being a physician, clinical experience, patient care impact) and modifiable factors (weekly interpretation volume, training hours, expert supervision frequency) were analyzed. Bivariate and multivariate analyses were used to generate a Comprehensive Model (incorporating all factors) and Actionable Model (incorporating modifiable factors only). Among 1206 participants analyzed, there were 72 (6.0%) primary care physicians, 146 (12.1%) cardiology fellows-in-training, 353 (29.3%) resident physicians, 182 (15.1%) medical students, 84 (7.0%) advanced practice providers, 120 (9.9%) nurses, and 249 (20.7%) allied health professionals. Among them, 571 (47.3%) were physicians and 453 (37.6%) were nonphysicians. The average test score was 56.4% ± 17.2%. Bivariate analysis demonstrated significant associations between test scores and >10 weekly ECG interpretations, being a physician, >5 training hours, patient care impact, and expert supervision but not clinical experience. In the Comprehensive Model, independent associations were found with weekly interpretation volume (9.9 score increase; 95% CI, 7.9-11.8; P < 0.001), being a physician (9.0 score increase; 95% CI, 7.2-10.8; P < 0.001), and training hours (5.7 score increase; 95% CI, 3.7-7.6; P < 0.001). In the Actionable Model, scores were independently associated with weekly interpretation volume (12.0 score increase; 95% CI, 10.0-14.0; P < 0.001) and training hours (4.7 score increase; 95% CI, 2.6-6.7; P < 0.001). The Comprehensive and Actionable Models explained 18.7% and 12.3% of the variance in test scores, respectively. Predictors of ECG interpretation proficiency include nonmodifiable factors like physician status and modifiable factors such as training hours and weekly ECG interpretation volume.

Impact of Computer-Interpreted ECGs on the Accuracy of Healthcare Professionals.

The interpretation of electrocardiograms (ECGs) involves a dynamic interplay between computerized ECG interpretation (CEI) software and human overread. However, the impact of computer ECG interpretation on the performance of healthcare professionals remains largely unexplored. The aim of this study was to evaluate the interpretation proficiency of various medical professional groups, with and without access to the CEI report. Healthcare professionals from diverse disciplines, training levels, and countries sequentially interpreted 60 standard 12-lead ECGs, demonstrating both urgent and nonurgent findings. The interpretation process consisted of 2 phases. In the first phase, participants interpreted 30 ECGs with clinical statements. In the second phase, the same 30 ECGs and clinical statements were randomized and accompanied by a CEI report. Diagnostic performance was evaluated based on interpretation accuracy, time per ECG (in seconds [s]), and self-reported confidence (rated 0 [not confident], 1 [somewhat confident], or 2 [confident]). A total of 892 participants from various medical professional groups participated in the study. This cohort included 44 (4.9%) primary care physicians, 123 (13.8%) cardiology fellows-in-training, 259 (29.0%) resident physicians, 137 (15.4%) medical students, 56 (6.3%) advanced practice providers, 82 (9.2%) nurses, and 191 (21.4%) allied health professionals. The inclusion of the CEI was associated with a significant improvement in interpretation accuracy by 15.1% (95% confidence interval, 14.3-16.0; P < 0.001), decrease in interpretation time by 52 s (-56 to -48; P < 0.001), and increase in confidence by 0.06 (0.03-0.09; P = 0.003). Improvement in interpretation accuracy was seen across all professional subgroups, including primary care physicians by 12.9% (9.4-16.3; P = 0.003), cardiology fellows-in-training by 10.9% (9.1-12.7; P < 0.001), resident physicians by 14.4% (13.0-15.8; P < 0.001), medical students by 19.9% (16.8-23.0; P < 0.001), advanced practice providers by 17.1% (13.3-21.0; P < 0.001), nurses by 16.2% (13.4-18.9; P < 0.001), allied health professionals by 15% (13.4-16.6; P < 0.001), physicians by 13.2% (12.2-14.3; P < 0.001), and nonphysicians by 15.6% (14.3-17.0; P < 0.001).CEI integration improves ECG interpretation accuracy, efficiency, and confidence among healthcare professionals.

Successful Prolonged Desensitization to Epoetin-Alfa Hypersensitivity in an Adult Patient With Advanced Chronic Kidney Disease.

The use of erythropoiesis-stimulating agents (ESAs) reduces the need for recurrent blood transfusions in patients with advanced kidney disease. Rarely, allergic reactions to recombinant human erythropoietin can develop, complicating anemia management due to cross-reactivity between these agents. We report the use of an outpatient desensitization protocol, which was successfully completed in an adult patient who developed a maculopapular rash as a form of delayed-type hypersensitivity reaction (DTH) to epoetin-alfa (EPO) use, followed by successful re-introduction of EPO and continued tolerance.

Exploring Factors Influencing ECG Interpretation Proficiency of Medical Professionals.

The electrocardiogram (ECG) is a crucial diagnostic tool in medicine with concerns about its interpretation proficiency across various medical disciplines. Our study aimed to explore potential causes of these issues and identify areas requiring improvement. A survey was conducted among medical professionals to understand their experiences with ECG interpretation and education. A total of 2515 participants from diverse medical backgrounds were surveyed. A total of 1989 (79%) participants reported ECG interpretation as part of their practice. However, 45% expressed discomfort with independent interpretation. A significant 73% received less than 5 hours of ECG-specific education, with 45% reporting no education at all. Also, 87% reported limited or no expert supervision. Nearly all medical professionals (2461, 98%) expressed a desire for more ECG education. These findings were consistent across all groups and did not vary between primary care physicians, cardiology FIT, resident physicians, medical students, APPs, nurses, physicians, and nonphysicians. This study reveals substantial deficiencies in ECG interpretation training, supervision, and confidence among medical professionals, despite a strong interest in increased ECG education.

Observational study of early diaphragm pacing in cervical spinal cord injured patients to decrease mechanical ventilation during the COVID-19 pandemic.

BACKGROUND: Decreasing the burden of mechanical ventilation for spinal cord injuries was never more relevant than during the COVID-19 pandemic. Data have shown diaphragm pacing can replace mechanical ventilation, decrease wean times, improve respiratory mechanics, and decrease hospital costs for patients with spinal cord injuries. This is the largest report of diaphragm pacing during the pandemic. METHODS: This is a retrospective analysis of prospective Institutional Review Board approved databases of nonrandomized interventional experience at a single institution. Subgroup analysis limited to traumatic cervical spinal cord injuries that were implanted laparoscopically with diaphragm electrodes within 30 days of injury. RESULTS: For the study group of early implanted traumatic cervical spinal cord injuries, 13 subjects were identified from a database of 197 diaphragm pacing implantations from January 1, 2020, to December 31, 2022, for all indications. All subjects were male with an average age of 49.3 years (range, 17-70). Injury mechanisms included falls (6), motor vehicle accident (4), gunshot wound (2), and diving (1). Time from injury to diaphragm pacing averaged 11 days (range, 3-22). Two patients are deceased and neither weaned from mechanical ventilation. Nine of the remaining 11 patients weaned from mechanical ventilation. Four patients never had a tracheostomy and 3 additional patients had tracheostomy decannulation. Three of these high-risk pulmonary compromised patients survived COVID-19 infections utilizing diaphragm pacing. CONCLUSION: Diaphragm pacing successfully weaned from mechanical ventilation 82% of patients surviving past 90 days. Forty-four percent of this group never underwent a tracheostomy. Only 22% of the weaned group required long term tracheostomies. Early diaphragm pacing for spinal cord injuries decreases mechanical ventilation usage and tracheostomy need which allows for earlier placement for rehabilitation.

The Use of Raw Poultry Waste as Soil Amendment Under Field Conditions Caused a Loss of Bacterial Genetic Diversity Together with an Increment of Eutrophic Risk and Phytotoxic Effects.

Poultry waste has been used as fertilizer to avoid soil degradation caused by the long-term application of chemical fertilizer. However, few studies have evaluated field conditions where livestock wastes have been used for extended periods of time. In this study, physicochemical parameters, metabarcoding of the 16S rRNA gene, and ecotoxicity indexes were used for the characterization of chicken manure and poultry litter to examine the effect of their application to agricultural soils for 10 years. Poultry wastes showed high concentrations of nutrients and increased electrical conductivity leading to phytotoxic effects on seeds. The bacterial communities were dominated by typical members of the gastrointestinal tract, noting the presence of pathogenic bacteria. Soils subjected to poultry manure applications showed statistically higher values of total and extractable phosphorous, increasing the risk of eutrophication. Moreover, while the soil bacterial community remained dominated by the ones related to the biogeochemical cycles of nutrients and plant growth promotion, losses of alpha diversity were observed on treated soils. Altogether, our work would contribute to understand the effects of common local agricultural practices and support the adoption of the waste treatment process in compliance with environmental sustainability guidelines.

Immediate Effects of Adding Dry Needling to Thoracic Manipulation and Exercise in Cervical Range of Motion for Adults With Neck Pain: A Randomized Clinical Trial.

OBJECTIVE: The purpose of this study was to determine the immediate effects of adding dry needling (DN) to thoracic spine manipulation and neck-specific exercise in individuals with neck pain. METHODS: Forty-two participants with neck pain were randomized to either the true (n = 21) or sham (n = 21) DN groups, receiving treatment on the initial visit and 2 to 3 days later. Outcomes were assessed on day 1, both at baseline and immediately after the initial treatment, at the second treatment 2 to 3 days later, and at the final visit 5 to 7 days after visit 2. Primary outcomes were Neck Disability Index (NDI) (0-50) and current pain via numeric pain rating scale (0-10). Secondary outcomes were cervical range of motion, pain pressure threshold, and global rating of change. RESULTS: Repeated measures analysis of covariance with baseline value as covariate revealed no significant difference in NDI scores at either follow-up time point with adjusted mean differences (95% confidence interval) of -0.11 (-2.70 to 2.48) and 0.31 (-1.96 to 2.57). There were no between-group differences in pain at any time point via Independent-Samples Median Test (P value range of .54-1.0). Secondary outcome measures were similarly not statistically different between groups except for immediate improvements in rotation to the side opposite of pain, which favored DN, with an adjusted mean difference (95% confidence interval) of 7.85 (3.54-12.15) degrees. CONCLUSION: The addition of DN to thoracic spinal manipulation and neck-specific exercise did not affect improvements in NDI score or numeric pain rating scale but showed an increase in cervical range of motion.

GFR Estimation in Potential Living Kidney Donors: Race- and Nonrace-based Equations and Measured GFR.

Rationale & Objective: Recent studies evaluated and proposed new race-neutral, creatinine-based glomerular filtration rate (GFR) estimation equations. The performance of these equations in diverse potential living kidney donors requires study. Study Design: Cross-sectional study. Setting & Participants: 637 potential living kidney donors from one tertiary hospital with serum creatinine concentration measurement and GFR measurement by iohexol plasma clearance between October 2016 and December 2020. Exposure: Creatinine-based estimation of GFR by Chronic Kidney Disease Epidemiology Collaboration (2009, CKDEPI09; 2021, CKDEPI21) and Modification of Diet in Renal Disease equations with and without inclusion of race coefficient, where applicable. Outcomes: Equation bias, precision, accuracy, and accurate classification of GFR as equal to and above or below 80 mL/min/1.73 m2. Analytical Approach: GFR estimation equation performance compared to measured GFR (mGFR) by iohexol clearance. Results: The median bias of the CKDEPI21 equation underestimated mGFR by 2.8 mL/min/1.73 m2. The bias in the Black subgroup underestimated mGFR by 9.0 mL/min/1.73 m2. Compared to CKDEPI09 with and without race adjustment, the accuracy of CKDEPI21 increased across all subgroups. On average, 3.9% of individuals were misclassified by CKDEPI21 as having a GFR greater than, and 8.9% misclassified less than, 80 mL/min/1.73 m2, compared to 3.1% and 13.2% for CKDEPI09 with race adjustment, respectively. Total misclassification (either above or below 80 mL/min/1.73 m2) was 16.3% for CKDEPI21 and 16.0% for CKDEPI09 (with race adjustment). Limitations: Limited sample of individuals identifying as Black. Lack of cystatin C data. Conclusions: In our potential living donor sample, GFR estimation by creatinine-based CKDEPI21 is less biased and more accurate than previous creatinine-based estimated GFR equations. When evaluated by race, this summative improvement remains in individuals identifying as Asian, Hispanic, or White. More external validation is needed to assess whether the new equation is an improvement over the previous CKDEPI equation with a race coefficient.

Nephrology Program Director Protected Time for Program Administration in the United States.

BACKGROUND AND OBJECTIVES: The Accreditation Council for Graduate Medical Education (ACGME) required that program directors receive 10-20 h/wk of protected time for program administration (including didactic teaching). In July 2022, this was reduced for all internal medicine subspecialties on the basis of program size, with 8 h/wk required for programs with fewer than seven fellows, the majority of nephrology programs. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We surveyed all 151 US adult nephrology program directors (ACGME Public List of Programs 2021-2022) to determine how much protected time they receive, how much they think is necessary, and the division of their professional time. The anonymous 20-question online survey was administered from March 31 to April 30, 2022. The analysis was descriptive. RESULTS: Response rate was 66% (99 of 151). Geographic distribution and approved fellow positions were similar to programs nationally; 59% had fewer than seven approved positions. Median protected time was 10 h/wk (interquartile range, 5-10), with 8 h/wk (interquartile range, 5-10) for those with fewer than seven positions. Program directors estimated needing 12 h/wk (interquartile range, 10-16) to effectively administer programs, including those with fewer than seven positions, a median 5 h/wk (interquartile range, 0-7) more than received. Of program directors reporting <10 h/wk for program administration, 62% provided >20 hours of direct patient care. Thirty-nine percent had no protected time for core faculty. Fellow recruitment (68%) was the most time-consuming task, and didactic teaching (80%) was the most professionally rewarding. CONCLUSIONS: Approximately half of the nephrology programs surveyed were not in compliance with the ACGME-stipulated 10-h/wk minimum protected time for the 2021-2022 training year. Program directors estimated a median of 12 h/wk are needed to effectively manage programs.

Phytoextraction of Cu, Cd, Zn and As in four shrubs and trees growing on soil contaminated with mining waste.

Mining activity has degraded large extensions of soil and its waste is composed of metals, anthropogenic chemicals, and sterile rocks. The use of native species in the recovery of polluted soils improves the conditions for the emergence of other species, tending to a process of ecosystem restoration. The objective of this study was to evaluate the bioaccumulation of metal(loid)s in four species of native plants and the effect of their distribution and bioavailability in soil with waste from an abandoned gold mine. Soil samples were taken from two sites in La Planta, San Juan, Argentina: Site 1 and Site 2 (mining waste and reference soil, respectively). In Site 1, vegetative organ samples were taken from Larrea cuneifolia, Bulnesia retama, Plectrocarpa tetracantha, and Prosopis flexuosa. The concentration of metal(loid)s in soil from Site 1 were Zn > As > Cu > Cd, reaching values of 7123, 6516, 240 and 76 mg kg-1, respectively. The contamination indices were among the highest categories of contamination for all four metal(loid)s. The spatial interpolation analysis showed the effect of the vegetation as the lowest concentration of metal(loid)s were found in rhizospheric soil. The maximum concentrations of As, Cu, Cd and Zn found in vegetative organs were 371, 461, 28, and 1331 mg kg-1, respectively. L. cuneifolia and B. retama presented high concentrations of Cu and Zn. The most concentrated metal(loid)s in P. tetracantha and P. flexuosa were Zn, As and Cu. Cd was the least concentrated metal in all four species. The values of BAF and TF were greater than one for all four species. In conclusion, the different phytoextraction capacities and the adaptations to arid environments of these four species are an advantage for future phytoremediation strategies. Their application contributes to the ecological restoration and risk reduction, allowing the recovery of ecosystem services.

Chronic toxicity, bioavailability and bioaccumulation of Zn, Cu and Pb in Lactuca sativa exposed to waste from an abandoned gold mine.

Abandoned mines with untreated waste cause environmental pollution. The complex mixture of mining waste includes high metal content, anthropogenic chemicals and sterile rocks. Adverse effects of contaminated soils have been widely assessed by the use of plants. The aim of this study was to assess the chronic toxicity of a contaminated soil by waste from an abandoned gold mine on Lactuca sativa and its relationship with the bioavailability and bioaccumulation of Zn, Cu and Pb. Soil samples were taken from the site of mining waste stacking and a reference site in La Planta (Argentina). Contamination indices were calculated and acute and chronic exposures on L. sativa were carried out. Phytotoxicity indices, morphological and biochemical parameters, and concentrations of Zn, Cu and Pb in pseudo total and bioavailable soil fractions and in plant tissue were determined. Concentration- and time-dependent toxicity effects were observed, especially on plant width, fresh aerial biomass, leaf area and percentage of plants with completely necrotic aerial biomass. High levels of Zn (1453.3 ± 220.3 µg g-1) were found in plant tissue compared to Pb (277.2 ± 18.0 µg g-1) and Cu (255.3 ± 25.6 µg g-1). Toxicological endpoints correlated with metal uptake and mining waste concentration. In addition, bioaccumulation factors correlated with mobilisable and water soluble fractions. The concentration of Pb in aerial biomass surpassed the permissible concentrations in leaf vegetables, even at the reference site, indicating that lettuce crop consumption could be risky for the local population's health. This study demonstrated a strong relationship between metal bioavailability, toxicity endpoints and bioaccumulation, contributing with novel information to future ecotoxicological risk assessments and remediation plans.