Distribution and release of PFAS from AFFF-impacted asphalt: How does it compare to concrete?

Aqueous film forming foam (AFFF)-impacted asphalt and concrete may serve as potential secondary sources of per- and polyfluoroalkyl substances (PFAS) to the environment through surficial leaching. We aimed to understand the vertical distribution and surficial release of PFAS from AFFF-impacted asphalt and concrete cores collected from various locations (∼10-70 m distance between samples). Among the PFAS analyzed, 6:2 FTS was observed as having the highest concentration in the surface layer (0 - 0.5 cm) of concrete (225 µg kg-1) and in the runoff from the concrete (2600 ng L-1). PFOS was detected at the highest concentration in the surface layer (0 - 0.5 cm) of asphalt (47 µg kg-1) and associated runoff (780 ng L-1). The total mass of PFAS released during three rainfall simulations accounts for a fraction of the total mass in the surface layer (0 - 0.5 cm), ranging from 0.10 - 9.8% and 0.078 - 2.4% for asphalt and concrete cores, respectively. Asphalt exhibited a higher release rate than concrete, demonstrated by the higher total release coefficient of PFAS (4 - 16 m-2) compared to that of concrete cores (1 - 5 m-2). These results suggested that, similar to concrete, AFFF-impacted asphalt may be a secondary source of PFAS to the environment.

Lewis Acidic Aluminosilicates: Synthesis, 27Al MQ/MAS NMR, and DFT-Calculated 27Al NMR Parameters.

Porous aluminosilicates are functional materials of paramount importance as Lewis acid catalysts in the synthetic industry, yet the participating aluminum species remain poorly studied. Herein, a series of model aluminosilicate networks containing [L-AlO3] (L = THF, Et3N, pyridine, triethylphosphine oxide (TEPO)) and [AlO4]- centers were prepared through nonhydrolytic sol-gel condensation reactions of the spherosilicate building block (Me3Sn)8Si8O20 with L-AlX3 (X = Cl, Me, Et) and [Me4N] [AlCl4] compounds in THF or toluene. The substoichiometric dosage of the Al precursors ensured complete condensation and uniform incorporation, with the bulky spherosilicate forcing a separation between neighboring aluminum centers. The materials were characterized by 1H, 13C, 27Al, 29Si, and 31P MAS NMR and FTIR spectroscopies, ICP-OES, gravimetry, and N2 adsorption porosimetry. The resulting aluminum centers were resolved by 27Al TQ/MAS NMR techniques and assigned based on their spectroscopic parameters obtained by peak fitting (δiso, CQ, η) and their correspondence to the values calculated on model structures by DFT methods. A clear correlation between the decrease in the symmetry of the Al centers and the increase of the observed CQ was established with values spanning from 4.4 MHz for distorted [AlO4]- to 15.1 MHz for [THF-AlO3]. Products containing exclusively [TEPO-AlO3] or [AlO4]- centers could be obtained (single-site materials). For L = THF, Et3N, and pyridine, the [AlO4]- centers were formed together with the expected [L-AlO3] species, and a viable mechanism for the unexpected emergence of [AlO4]- was proposed.

Biomonitoring of per- and polyfluoroalkyl substances (PFAS) exposure in firefighters: Study design and lessons learned from stakeholder and participant engagement.

Firefighters may be occupationally exposed to per- and polyfluoroalkyl substances (PFASs) through Aqueous Film-Forming Foam (AFFF), smoke, dust and turnout gear, in addition to other background exposure sources. Epidemiological assessment of PFAS exposure in an occupational cohort of firefighting staff commenced in 2013-2014, following cessation of PFAS-based AFFF in Australian aviation. Here we present the study design and methodology of a follow-up study conducted in 2018-2019. We focus on our experiences engaging with stakeholders and participants with the establishment of an inclusive study group and highlight the key lessons learned from implementing a co-design process in the study. The study included a cross-sectional assessment of blood serum concentrations of 40 PFASs, including perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS), and 14 health-related biomarkers in 799 current and former Aviation Rescue Firefighting Services employees. A large proportion (87%) of the participants from the preliminary exposure study in 2013-2014 were re-recruited in the follow-up study. This enabled further longitudinal analyses in this subset of 130 participants. Participants included employees from different work roles and timeframes, reflecting the periods when three different firefighting foams were utilised in Australia. Establishment of a collaborative and inclusive study group (including stakeholders and participants) contributed to several components of the study design, including the expansion of robust analytical quality assurance and control measurements, and tailoring of communication and dissemination strategies. These outcomes were key factors that improved transparency of the research design, methods and results. Additionally, implementing elements of co-design helped build trust between researchers and participants, which is an important consideration for studies funded by stakeholders related to the exposure source.

The Biomedical Research Hub: a federated platform for patient research data.

OBJECTIVE: The objective was to develop and operate a cloud-based federated system for managing, analyzing, and sharing patient data for research purposes, while allowing each resource sharing patient data to operate their component based upon their own governance rules. The federated system is called the Biomedical Research Hub (BRH). MATERIALS AND METHODS: The BRH is a cloud-based federated system built over a core set of software services called framework services. BRH framework services include authentication and authorization, services for generating and assessing findable, accessible, interoperable, and reusable (FAIR) data, and services for importing and exporting bulk clinical data. The BRH includes data resources providing data operated by different entities and workspaces that can access and analyze data from one or more of the data resources in the BRH. RESULTS: The BRH contains multiple data commons that in aggregate provide access to over 6 PB of research data from over 400 000 research participants. DISCUSSION AND CONCLUSION: With the growing acceptance of using public cloud computing platforms for biomedical research, and the growing use of opaque persistent digital identifiers for datasets, data objects, and other entities, there is now a foundation for systems that federate data from multiple independently operated data resources that expose FAIR application programming interfaces, each using a separate data model. Applications can be built that access data from one or more of the data resources.

Comparing the Leaching Behavior of Per- and Polyfluoroalkyl Substances from Contaminated Soils Using Static and Column Leaching Tests.

Soil contaminated with aqueous film-forming foams (AFFFs) containing per- and polyfluoroalkyl substances (PFASs) at firefighting training sites has become a major concern worldwide. To date, most studies have focused on assessing soil-water partitioning behavior of PFASs and the key factors that can affect their sorption, whereas PFASs leaching from contaminated soils have not yet been widely investigated. This study evaluated the leaching and desorption of a wide range of PFASs from twelve contaminated soils using the Australian Standard Leaching Procedure (ASLP), the U.S. EPA Multiple Extraction Procedure (MEP), and Leaching Environmental Assessment Framework (LEAF). All three leaching tests provided a similar assessment of PFAS leaching behavior. Leaching of PFASs from soils was related to C-chain lengths and their functional head groups. While short-chain (CF2 ≤ 6) PFASs were easily desorbed and leached, long-chain PFASs were more difficult to desorb. PFASs with a carboxylate head group were leached more readily and to a greater extent than those with a sulfonate or sulfonamide head group. Leaching of long-chain PFASs was pH-dependent where leaching increased at high pH, while leaching of short-chain PFASs was less sensitive to pH. Comparing different leaching tests showed that the results using the alkaline ASLP were similar to the cumulative MEP data and the former might be more practical for routine use than the MEP. No single soil property was adequately able to describe PFAS leaching from the soils. Overall, the PFAS chemical structure appeared to have a greater effect on PFAS leaching from soil than soil physicochemical properties.

Sorbent assisted immobilisation of perfluoroalkyl acids in soils - effect on leaching and bioavailability.

Contamination of soils and groundwater with perfluoroalkyl acids (PFAAs) is widespread due to their use in aqueous film-forming foams (AFFF). In this study the effectiveness of RemBind®, a sorbent containing activated carbon and aluminium oxyhydroxides was tested, as a tool to reduce the leaching and bioavailability of 12 PFAAs in soils, by amending contaminated soils with 5-30% (by weight) of the sorbents. Batch tests were used to determine the leaching of PFAAs. Their bioavailability to earthworms and wheat grass was assessed in greenhouse microcosms. Leaching and bioavailability of PFOS was reduced by up to 99.9%, at most sorbent application rates. Lowest reduction of leaching was found for shorter perfluoroalkyl chain length chemicals. The specific formulation of RemBind®, which is available in a basic and superior formulation, as well as the application rate were parameters for increasing effectiveness of the treatment. Furthermore, differences in leaching as well as bioavailability were seen depending on the perfluoroalkyl chain length. A preliminary assessment of the long-term stability of the treatment, assessed after a three-year curing period, suggested that the sorbent continued to be effective in reducing PFAAs in leachates, thus showing the potential of this sorbent to hinder further environmental contamination.

Influences of Chemical Properties, Soil Properties, and Solution pH on Soil-Water Partitioning Coefficients of Per- and Polyfluoroalkyl Substances (PFASs).

The aim of this study was to assess the soil-water partitioning behavior of a wider range of per- and polyfluoroalkyl substances (PFASs) onto soils covering diverse soil properties. The PFASs studied include perfluoroalkyl carboxylates (PFCAs), perfluoroalkane sulfonates (PFSAs), fluorotelomer sulfonates (FTSs), nonionic perfluoroalkane sulfonamides (FASAs), cyclic PFAS (PFEtCHxS), per- and polyfluoroalkyl ether acids (GenX, ADONA, 9Cl-PF3ONS), and three aqueous film-forming foam (AFFF)-related zwitterionic PFASs (AmPr-FHxSA, TAmPr-FHxSA, 6:2 FTSA-PrB). Soil-water partitioning coefficients (log Kd values) of the PFASs ranged from less than zero to approximately three, were chain-length-dependent, and were significantly linearly related to molecular weight (MW) for PFASs with MW > 350 g/mol (R2 = 0.94, p < 0.0001). Across all soils, the Kd values of all short-chain PFASs (≤5 -CF2- moieties) were similar and varied less (<0.5 log units) compared to long-chain PFASs (>0.5 to 1.5  log units) and zwitterions AmPr- and TAmPr-FHxSA (∼1.5 to 2 log units). Multiple soil properties described sorption of PFASs better than any single property. The effects of soil properties on sorption were different for anionic, nonionic, and zwitterionic PFASs. Solution pH could change both PFAS speciation and soil chemistry affecting surface complexation and electrostatic processes. The Kd values of all PFASs increased when solution pH decreased from approximately eight to three. Short-chain PFASs were less sensitive to solution pH than long-chain PFASs. The results indicate the complex interactions of PFASs with soil surfaces and the need to consider both PFAS type and soil properties to describe mobility in the environment.

Dynamic ultrasound in the evaluation of patients with suspected slipping rib syndrome.

OBJECTIVE: Slipping rib syndrome (SRS) affects adolescents and young adults. Dynamic ultrasound plays a potential and likely significant role; however, limited data exist describing the protocol and techniques available. It is our intent to describe the development of a reproducible protocol for imaging in patients with SRS. MATERIALS AND METHODS: Retrospective review of suspected SRS patients from March 2017 to April 2018. A total of 46 patients were evaluated. Focused history and imaging was performed at the site of pain. Images of the ribs were obtained in the parasagittal plane at rest and with dynamic maneuvers. Dynamic maneuvers included Valsalva, crunch, rib push maneuver, and any provocative movement that elicited pain. Imaging was compared with records from the pediatric surgeon specializing in slipping ribs. Statistical analysis was performed. RESULTS: Thirty-six of the 46 patients had a diagnosis of SRS, and had an average age of 17 years. Thirty-one patients were female, 15 were male. Thirty-one out of 46 (67%) were athletes. Average BMI was 22.6. Dynamic ultrasound correctly detected SRS in 89% of patients (32 out of 36) and correctly detected the absence in 100% (10 out of 10). Push maneuver had the highest sensitivity (87%; 0.70, 0.96) followed by morphology (68%; 0.51, 0.81) and crunch maneuver (54%; 0.37, 0.71). Valsalva was the least sensitive (13%; 0.04, 0.29). CONCLUSION: Dynamic ultrasound of the ribs, particularly with crunch and push maneuvers, is an effective and reproducible tool for diagnosing SRS. Valsalva plays a limited role. In addition to diagnosing SRS, ultrasound can give the surgeon morphological data and information on additional ribs at risk, thereby assisting in surgical planning.

Leaching and bioavailability of selected perfluoroalkyl acids (PFAAs) from soil contaminated by firefighting activities.

Historical usage of aqueous film-forming foam (AFFF) at firefighting training grounds (FTGs) is a potential source of perfluoroalkyl acids (PFAAs) to the surrounding environment. In this study the leaching of PFAAs from field contaminated soil and their uptake into biota was investigated. Soil was sampled from FTGs at two airports and the total as well as the leachable concentration of 12 PFAAs was determined. A greenhouse study was carried out to investigate the uptake of PFAAs from soils into earthworms (Eisenia fetida) and wheat grass (Elymus scaber). Perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were the most dominant PFAAs in all soils samples, with concentrations of PFOS reaching 13,400 ng/g. Leachable concentrations of PFOS and PFHxS reached up to 550 µg/L and 22 µg/L, respectively. In earthworms concentrations of PFOS reached 65,100 ng/g after a 28-day exposure period, while in wheat grass the highest concentration was measured for uptake of PFHxS (2,800 ng/g) after a 10-week growth-period. Bioaccumulation factors (BAFs) for earthworms ranged from 0.1 for perfluorohexanoic acid (PFHxA) to 23 for perfluorododecanoic acid (PFDoA) and initially showed a decreasing trend with increasing perfluoroalkyl chain length, followed by an increase with increasing perfluoroalkyl chain length for perfluoroalkyl carboxylic acids (PFCAs). In wheat grass the highest BAF was found for perfluorobutanoic acid (BAF = 70), while the lowest was observed for perfluorononanoic acid (BAF = 0.06). BAFs in wheat grass decreased with increasing perfluoroalkyl chain length for both PFCAs and perfluoroalkyl sulfonic acids (PFSAs). The results show that PFAAs readily leach from impacted soils and are bioaccumulated into earthworms and plants in an analyte dependent way. This shows considerable potential for PFAAs to move away from the original source either by leaching or uptake into ecological receptors, which may be a potential entry route into the terrestrial foodweb.

Three-Dimensional Technology to Diagnose Unilateral Cervical Atresia in Obstructive Hemivagina with Ipsilateral Renal Anomaly: A Case Report and Review of the Literature.

BACKGROUND: Congenital atresia of the cervix in the setting of an obstructed hemivagina with ipsilateral renal anomaly (OHVIRA) is an unusual occurrence that is frequently missed using preoperative imaging modalities. CASE: A 14-year-old female adolescent presented to a tertiary care facility with abdominal pain associated with a mass. Initial imaging with ultrasound and magnetic resonance suggested OHVIRA but 3-D magnetic resonance imaging (MRI) also correctly identified unilateral cervical atresia on the obstructed left side. SUMMARY AND CONCLUSION: Three-dimensional MRI in the setting of OHVIRA was used successfully in this case to preoperatively identify cervical atresia and to guide preoperative surgical counseling and planning. The use of 3-D MRI for this purpose has, to our knowledge, never been described in the literature. Three-dimensional printed models derived from 3-D MRI can play an evolving role in the management of Müllerian anomalies as preoperative planning and surgical counseling tools.

Seven rules to live by: accommodations in social work education and the field.

Students with disabilities are a growing population in higher education (National Center for Education Statistics, 2009 ). Providing accommodations for students with disabilities can raise ethical and social justice questions and pose challenges for social work faculty, administrators, and field instructors. Social work educators must balance the legal mandates for nondiscrimination and reasonable accommodation against ethical obligations around protection of clients and preparation for practice. This article presents case examples in the context of legal analysis to help social work educators make difficult decisions about student academic performance.

The role of cephalometry in assessing velopharyngeal dysfunction in velocardiofacial syndrome.

OBJECTIVE: To report our experience with cephalometry in evaluating velopharyngeal dysfunction (VPD) in velocardiofacial syndrome (VCFS) and its utility in assessing the role of cervical spine abnormalities in VPD, prior to surgical correction of VPD. DESIGN: Clinical charts and cephalometric radiographs done prior to surgery for VPD were retrospectively analyzed to ascertain velopharyngeal measurements and cervical spine abnormalities. PATIENTS: Twenty-six patients (age: 6-23 years) with molecularly confirmed VCFS. SETTING: Wake Forest University Health Sciences (1997-2005). MEASUREMENTS: Cranial base angle, nasopharyngeal depth, velum length, and Need ratio at rest, velar dimple location, and velopharyngeal length during phonation; information on presence/absence of submucous cleft palate and cervical spine abnormalities were also obtained. The relationship between C1 anterior arch abnormalities and Need ratio was examined. RESULTS: Seventy-three percent of the VCFS patients had excessive nasopharyngeal depth, 80% had an abnormal Need ratio, 50% had a short velum, 81% had a submucous or occult submucous cleft palate, 90.5% had a cervical spine abnormality (C1 anterior arch abnormalities in 38%) and 11.5% had platybasia. There was a significant difference in the Need ratio between patients with and without C1 anterior arch abnormalities. CONCLUSION: Cephalometry can be used to delineate factors such as C1 vertebral abnormalities, excessive pharyngeal depth, and short velum that contribute to VPD in VCFS. This would help otolaryngologists better understand the anatomy prior to surgical treatment of VPD. This is the first study to highlight the frequent occurrence of C1 anterior arch abnormalities in VCFS.

Retropharyngeal edema: an unusual manifestation of Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is an acute multisystem vasculitis of unknown etiology that typically affects young children. KD presenting as a retropharyngeal inflammatory process is very rare. OBJECTIVES: To report a case of KD initially presenting as a retropharyngeal edema mimicking a deep neck infection, and to review previously published reports in the literature. CASE REPORT: We report a case of KD in a previously healthy 3-year-old child who presented with acute onset of fever and cervical adenitis, along with computed tomography scan findings of retropharyngeal edema and inflammation. KD was suspected due to persistent fever and no improvement in the patient's condition despite appropriate antibiotic therapy; and other classic findings of KD eventually developed. An echocardiogram obtained on the 10th day of illness revealed pericardial effusion but no coronary ectasia or aneurysm. Treatment with high-dose intravenous immunoglobulin resulted in dramatic clinical improvement. Follow-up echocardiograms obtained 2 and 8 weeks after discharge revealed a small left coronary artery aneurysm (CAA). Nine months later, the CAA had resolved and the patient was well with no sequelae. CONCLUSIONS: Although unusual, physicians should be aware of retropharyngeal edema as an atypical presentation of KD.

119Sn NMR chemical shift tensors in anhydrous and hydrated Si8O20(SnMe3)8 crystals.

(119)Sn chemical shift tensors of crystalline trialkyltin functionalized octameric spherosilicates, Si(8)O(20)(SnMe(3))(8), have been determined by fitting sideband intensities in solid-state magic angle spinning (MAS) NMR spectra. Tin chemical shift parameters are exquisitely sensitive to the presence of water of crystallization. Both hydrogen bonding and incipient oxygen-tin bonding from molecular water impact the local tin environment. Tin chemical shift tensors in the crystalline derivatives reflect the changes in geometry and coordination number at the tin centers. Chemical shift correlations on the crystalline derivatives, with known x-ray structures, are used to infer the tin coordination environment in an amorphous sample.

MR urography: techniques and clinical applications.

Magnetic resonance (MR) urography comprises an evolving group of techniques with the potential for allowing optimal noninvasive evaluation of many abnormalities of the urinary tract. MR urography is clinically useful in the evaluation of suspected urinary tract obstruction, hematuria, and congenital anomalies, as well as surgically altered anatomy, and can be particularly beneficial in pediatric or pregnant patients or when ionizing radiation is to be avoided. The most common MR urographic techniques for displaying the urinary tract can be divided into two categories: static-fluid MR urography and excretory MR urography. Static-fluid MR urography makes use of heavily T2-weighted sequences to image the urinary tract as a static collection of fluid, can be repeated sequentially (cine MR urography) to better demonstrate the ureters in their entirety and to confirm the presence of fixed stenoses, and is most successful in patients with dilated or obstructed collecting systems. Excretory MR urography is performed during the excretory phase of enhancement after the intravenous administration of gadolinium-based contrast material; thus, the patient must have sufficient renal function to allow the excretion and even distribution of the contrast material. Diuretic administration is an important adjunct to excretory MR urography, which can better demonstrate nondilated systems. Static-fluid and excretory MR urography can be combined with conventional MR imaging for comprehensive evaluation of the urinary tract. The successful interpretation of MR urographic examinations requires familiarity with the many pitfalls and artifacts that can be encountered with these techniques.

Soft tissue amyloidoma of the extremities: a case report and review of the literature.

The deposition of amyloid as a distinct, clinically apparent mass is uncommon, particularly in soft tissues. Among reported sites of soft tissue amyloidomas, the extremities are quite rare. Amyloid tumors can mimic malignant neoplasms both clinically and radiologically. We report a case of AA amyloidoma presenting in the deltoid region with radiological features suggesting sarcoma. Cytomorphology from fine-needle aspiration material, tissue histology, and appearance by magnetic resonance imaging are described. The literature on soft tissue amyloidoma is reviewed.

Spontaneous formation of an exfoliated polystyrene-clay nanocomposite using a star-shaped polymer.

Mixtures of five-arm star polystyrene with an organoclay spontaneously formed exfoliated nanocomposites when annealed, validating a recent theoretical prediction by Singh and Balazs (Polym. Int. 2000, 49, 469.). An analogous linear polystyrene sample produced only an intercalated morphology under the same conditions. The nanocomposite morphologies were characterized by X-ray diffraction and transmission electron microscopy. These results suggest a general strategy for forming exfoliated nanocomposites in commodity polymers via melt compounding.

Building block syntheses of site-isolated vanadyl groups in silicate oxides.

Cross-linking of the cubic silicate building block, Si8O20 with vanadyl chloride leads to porous solids in which a homogeneous dispersion of isolated vanadyl groups is maintained throughout the matrix even at high loadings of vanadium.

Mechanistic investigation of hydrolysis reactions of dithioacetal derivatives grafted on silica gels.

Silica gels believed to be grafted with dithioacetal derivatives were recently used for Hg(II) extraction, and were found to selectively remove 94-100% of Hg(2+) ions from metal ion mixtures. The current studies with one derivative suggest that the functional group in the Hg(II) removal is the mercapto (SH) ligand. The dithioacetal group in (ClCOCH(2)S)(2)CHPh (2) was hydrolyzed during its reaction with amine (O)(3)Si(CH(2))(3)NH(2) (3) grafted on silica gel to give the mercapto ligand (O)(3)Si(CH(2))(3)NHCOCH(2)SH (4). The silica gel grafted with the mercapto ligand 4 selectively removed Hg(2+) ions with reported high capacities.