One-pot synthesis of sulfonic acid functionalized Zr-MOFs for rapid and specific removal of radioactive Ba2.

Efficient decontamination of radioactive Ba2+ is of great significance to human health and environmental safety. Herein, an adsorbent based on the sulfonic acid functionalized Zr-MOF has been successfully developed, which could efficiently decontaminate radioactive Ba2+ with excellent selectivity, recyclability, a high adsorption capacity up to 60.8 mg g-1 as well as a short adsorption kinetic time of less than 5 min. This outstanding adsorption performance is attributed to the strong affinity between Ba2+ and high density -SO3H active sites in MOFs which were introduced by an in situ ligand modification strategy during the assembly of MOFs.

Nuclear data for reactor production of 131Ba and 133Ba.

The newest radioisotope for brachytherapy treatment of prostate cancer is 131Cs (t1/2 = 9.69 d, 100% EC). Generated via electron capture decay of 131Ba (t1/2 = 11.6 d, 100% EC), 131Cs has been used in brachytherapy for prostate cancer since 2004. The 131Ba parent is produced through neutron capture of enriched 130Ba in a nuclear reactor. For large-scale production of 131Ba, an accurate knowledge of production and burnup cross sections of 131Ba are essential. In this paper, we report two group cross sections (thermal and resonance integrals) for 130Ba and 131Ba and a new measure of the half-life of 131Ba. Targets consisting of milligram quantities of enriched 130Ba (∼35%) were irradiated in Oak Ridge National Laboratory's High Flux Isotope Reactor at thermal and resonance neutron fluxes of (1.9-2.1) × 1015 and (5.8-7.0) × 1013 neutrons·cm-2 s-1, respectively, for durations ranging from 3 to 26 days. In addition, cadmium covered samples of 130Ba were irradiated for 1 hour at 12.6% full reactor power (10.7 MW). The yield of 131Ba approaches a saturation value of ∼60 GBq (∼1.6 Ci) per mg of 130Ba for 20 days irradiation at a thermal neutron flux of 1.8 × 1015 n·s-1·cm-2, with a thermal/epithermal ratio of ∼30. Under the above experimental conditions, the two group cross sections of 130Ba are 6.9 ±â€¯0.5 b (thermal, σ0) and 173 ±â€¯7 b (resonance, I0). These values represent the sum of cross sections to metastable and ground states of 131Ba. For 131Ba, the empirically measured thermal cross section is 200 ±â€¯50 b assuming an I0/σ0 of 10. This cross section is reported for the first time. Further, the half-life of 131Ba was remeasured to be 11.657 ±â€¯0.008 d. Lastly, this study also resulted in the co-production of 133Ba (t1/2 = 10.52 y, 100% EC). The experimental yield of 133Ba is ∼370 MBq (∼10 mCi) per mg of 132Ba (thin target) for one cycle irradiation in the High Flux Isotope Reactor, and measured two-group 132Ba cross sections are 7.2 ±â€¯0.2 b and 39.9 ±â€¯1.3 b. These values also represent the sum of cross sections to metastable and ground states of 133Ba.

Physiological Compensation for Advanced Bolus Location at Swallow Onset: A Retrospective Analysis in Healthy Seniors.

Purpose Previous work has established that advanced bolus location at swallow onset (BLSO) alone is not correlated with an increased swallowing safety risk in healthy seniors. The primary goal of this retrospective study was to examine whether healthy seniors systematically alter their laryngeal vestibule closure reaction time (LVCrt) to maintain a safe swallow in the context of advanced BLSO. The secondary goal was to determine if longer LVCrt distinguished Penetration-Aspiration Scale (PAS; Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996) scores of 1 versus 2. Method Videofluoroscopy studies from 43 healthy seniors (21 men, 22 women; M age = 76.7 years, SD = 7.2) were analyzed. LVCrt was calculated for 3 × 5 ml and 3 × 20 ml thin liquid barium boluses per participant. PAS and BLSO (Modified Barium Swallow Impairment Profile Component 6) were scored for all swallows. Reliability (intraclass correlation coefficient > .75) was established on all measures. A linear mixed-effects regression was run to examine the effect of PAS and BLSO on LVCrt while controlling for bolus volume and repeated swallow trial. Results There was a main effect of BLSO (F = 4.6, p = .004) and PAS (F = 29.3, p < .001) on LVCrt. Post hoc pairwise comparisons revealed that LVCrt was significantly faster in BLSO scores of 3 (pyriforms) compared to scores of both 0 (posterior angle of the ramus) and 1 (valleculae). Significantly prolonged LVCrt was observed in PAS scores of 2 in comparison to 1. No significant main effects of bolus volume or trial, or interactions, were observed. Conclusions Our findings suggest that healthy seniors compensate for advanced BLSO by increasing their LVCrt. Furthermore, faster LVCrt was shown to distinguish PAS scores of 1 versus 2. Additional work should explore the relationship between LVCrt, BLSO, and PAS scores in dysphagic populations, specifically those with known sensory impairments.

Natural history of silent aspiration on modified barium swallow studies in the pediatric population.

OBJECTIVES: To investigate the natural history of silent aspiration in the pediatric population. METHODS: Retrospective chart review of patients (age < 3 years) who underwent modified barium swallow studies (MBSS), between January 1, 2007, to December 31, 2017, were studied to compare comorbidities and determine course of resolution in those with silent aspiration. RESULTS: A total of 148 charts were reviewed. Patients that underwent surgical intervention for laryngeal anomalies causing silent aspiration and those with overt aspiration or oral aversion were excluded. Of the 56 patients in the study, 25 had silent aspiration and 31 demonstrated no silent aspiration on MBSS. There was a higher rate of overall comorbidities amongst silent aspirators (96.0% vs. 48.4%, p=0.003) in comparison to patients with no silent aspiration on MBSS. Silent aspirators had higher rates of cerebral palsy (16.0% vs. 0%, p=0.034), and seizures (36.0% vs. 3.2%, p=0.003). Of the 20 patients with silent aspiration with an MBSS completed beyond the initial one, 13 (65.0%) experienced resolution, 5 (20.0%) did not experience resolution by age 5, and 2 (10.0%) had unknown resolution due to being lost to follow up or not yet reaching age 5. No statistically significant associations were found between comorbidities, gender, presence of a gastrostomy tube and resolution. CONCLUSIONS: Silent aspiration in children is associated with neurological comorbidities, particularly cerebral palsy and seizures. More than half of the patients with silent aspiration spontaneously resolve over time. Expectant management, close surveillance, and clinical assessments can be considered in these patients on an individual basis.

The Association of 3-D Volume and 2-D Area of Post-swallow Pharyngeal Residue on CT Imaging.

Pharyngeal residue, the material that remains in the pharynx after swallowing, is an important marker of impairments in swallowing and prandial aspiration risk. The goals of this study were to determine whether the 2D area of post-swallow residue accurately represents its 3D volume, and if the laterality of residue would affect this association. Thirteen patients with dysphagia due to brainstem stroke completed dynamic 320-detector row computed tomography while swallowing a trial of 10 ml honey-thick barium. 3D volumes of pharyngeal residue were compared to 2D lateral and anterior-posterior areas, and a laterality index for residue location was computed. Although the anteroposterior area of residue was larger than the lateral area, the two measures were positively correlated with one another and with residue volume. On separate bivariate regression analyses, residue volume was accurately predicted by both lateral (R2 = 0.91) and anteroposterior (R2 = 0.88) residue areas, with limited incidence of high residuals. Half of the sample demonstrated a majority of pharyngeal residue lateralized to one side of the pharynx, with no effect of laterality on the association between areas and volume. In conclusion, the area of post-swallow pharyngeal residue was associated with volume, with limitations in specific cases. Direct measurement of pharyngeal residue volume and swallowing physiology with 3D-CT can be used to validate results from standard 2D instrumentation.

Improving the Diagnostic Capability of the Modified Barium Swallow Study Through Standardization of an Esophageal Sweep Protocol.

The modified  barium swallow (MBS) study is a videofluoroscopic evaluation of oropharyngeal swallow function. Esophageal imaging is not routinely performed during an MBS, and few guidelines for implementation or interpretation exist. Aims of the current investigation were to (1) delineate the percentage of normal, oropharyngeal, esophageal, and mixed swallowing dysfunction, (2) develop operational definitions for rating our standardization cursory view of esophageal bolus flow, and (3) determine inter-rater reliability between speech pathology (SLP) and physician raters for categorizing esophageal abnormalities. A two-phase retrospective review of 358 patient charts and MBS studies was conducted. Esophageal bolus flow was operationally defined as (1) normal, (2) anatomic abnormality, (3) dysmotility and (4) combined. Descriptive statistics, a Chi square with alpha set at 0.05, and Kappa analysis were performed. Esophageal dysfunction was identified in 80 (26%) patients and included: anatomic abnormality (69%), dysmotility (17%), and combined abnormality (14%). Phase one reliability testing yielded fair agreement between SLP and MD raters k = 0.5. Following revision of definitions and consensus training, phase two reliability testing resulted in excellent agreement between the same raters k = 0.9. Multiphase or primary esophageal dysphagia was found in 26% of our sample using a standardized protocol rating esophageal bolus flow from the upper esophageal sphincter through the lower esophageal sphincter during the MBS. Improved agreement between SLP and MD raters after definition revision and training suggests these operational definitions are concise, objective and reliable. An expanded MBS study may lead to early identification of esophageal disorders, encourage multidisciplinary patient care, and improve patient health outcomes.

Tongue Pressure Measurement and Videofluoroscopic Study of Swallowing in Patients with Parkinson's Disease.

This study investigated the relationship between tongue pressure during swallowing and dysphagia in patients with Parkinson's disease (PD). A total of 24 patients with PD (12 men and 12 women, mean age 70.4 years) were studied. Their mean Hoehn and Yahr scale was 3.0 ± 1.3 (range 1-5). All participants underwent tongue pressure measurement and videofluorography during swallowing. Tongue pressure when swallowing 5 mL of barium on videofluorography was measured using a sensor sheet with five sensors. Based on the findings of videofluorography, the patients were divided into two groups: dysphagic PD group (n = 9) and non-dysphagic PD group (n = 15). The maximal magnitude (kPa), duration (s), time to peak pressure (s), and pressure gradient (kPa/s) of tongue pressure were analyzed for each part. For duration, time to peak pressure, and pressure gradient, similar values were calculated from the total waveform. There was no significant difference in maximal tongue pressure between the groups. The dysphagic PD group had prolonged duration of tongue pressure and time to peak pressure and a reduced pressure gradient compared with the non-dysphagic PD group. These results indicate that there is a clear difference in the temporal aspects of tongue pressure between the non-dysphagic and dysphagic PD patients. These differences provide the characteristics of tongue movement during swallowing in PD patients with dysphagia, which may be useful for the diagnosis and treatment of dysphagia.

Characterizing the Flow of Thickened Barium and Non-barium Liquid Recipes Using the IDDSI Flow Test.

The use of thickened liquids for dysphagia management has become wide-spread. Videofluoroscopy is commonly used to determine dysphagia severity and to evaluate the effectiveness of interventions, including texture modification, but this requires the use of radio-opaque contrast media. In order for the results of a videofluoroscopy to have validity with respect to confirming swallowing safety and efficiency on different liquid consistencies, it is important to understand the flow characteristics of the contrast media used and how the flow of these stimuli compares to the flow of liquids that are provided outside the assessment context. In this study, we explored the flow characteristics of 20% w/v barium and non-barium stimuli prepared using starch and gum thickeners to reach the slightly, mildly and moderately thick liquid categories defined by the International Dysphagia Diet Standardisation Initiative (IDDSI). Our goal was to identify recipes that would produce stimuli with stable flow properties over a 3 h time frame post mixing. Thickener concentration was titrated to achieve matching flow (i.e., IDDSI Flow Test results within a 1 ml range) across the four stimulus types (non-barium starch, non-barium gum, barium starch, barium gum) within each IDDSI level. The combination of barium and thickeners resulted in further thickening, particularly with starch-based thickening agents. A probe of the influence of refrigeration showed no difference in flow measures between chilled and room temperature stimuli over a 3-h time frame. Overall, recipes with stable flow over three hours were identified for all barium and non-barium liquids tested.

Volumetric Changes to the Pharynx in Healthy Aging: Consequence for Pharyngeal Swallow Mechanics and Function.

Pharyngeal lumen volume is prone to increase as a consequence of pharyngeal muscle atrophy in aging. Yet, the impact of this on swallowing mechanics and function is poorly understood. We examined the relationship between pharyngeal volume and pharyngeal swallowing mechanics and function in a sample of healthy community-dwelling seniors. Data were collected from 44 healthy seniors (21 male, mean age = 76.9, SD = 7.1). Each participant swallowed 9 boluses of barium (3 × 5 ml thin, 3 × 20 ml thin, 3 × 5 ml nectar). Pharyngeal shortening, pharyngeal constriction, pyriform sinus and vallecular residue were quantified from lateral view videofluorosopic swallowing studies. Pharyngeal lumen volume was captured during an oral breathing task with acoustic pharyngometry. In addition, within-participant measures of strength and anthropometrics were collected. Four linear mixed effects regression models were run to study the relationship between pharyngeal volume and pharyngeal constriction, pharyngeal shortening, pyriform sinus residue, and vallecular residue while controlling for bolus condition, age, sex, and posterior tongue strength. Increasing pharyngeal lumen volume was significantly related to worse constriction and vallecular residue. In general, larger and thicker boluses resulted in worse pharyngeal constriction and residue. Pharyngeal shortening was only significantly related to posterior tongue strength. Our work establishes the utility of acoustic pharyngometry to monitor pharyngeal lumen volume. Increasing pharyngeal lumen volume appears to impact both pharyngeal swallowing mechanics and function in a sample of healthy, functional seniors.

Encapsulating Peritoneal Sclerosis: The Abdominal Cocoon.

Encapsulating peritoneal sclerosis (EPS) is a rare but serious condition that results in (a) encapsulation of bowel within a thickened fibrocollagenous peritoneal membrane and (b) recurrent episodes of bowel obstruction. Although described by various names in the literature, the preferred term is encapsulating peritoneal sclerosis because it best describes the morphologic and histologic changes in this disorder. The etiology of EPS is multifactorial, with a wide variety of implicated predisposing factors that disrupt the normal physiologic function of the peritoneal membrane-prime among these factors being long-term peritoneal dialysis and bacterial peritoneal infections, especially tuberculosis. The clinical features of EPS are usually nonspecific, and knowledge of the radiologic features is necessary to make a specific diagnosis. The findings on radiographs are usually normal. Images from small-bowel follow-through studies show the bowel loops conglomerated in a concertina-like fashion with a serpentine arrangement in a fixed U-shaped configuration. US demonstrates a "cauliflower" appearance of bowel with a narrow base, as well as a "trilaminar" appearance depicted especially with use of high-resolution US probes. CT is the imaging modality of choice and allows identification of the thickened contrast material-enhanced abnormal peritoneal membrane and the encapsulated clumped bowel loops. In addition, CT can potentially help identify the cause of EPS (omental granuloma in tuberculosis), as well as the complications of EPS (bowel obstruction). Conservative medical treatment and surgical therapy early in the course of EPS have been used for management of the condition. The purpose of this article is to review the nomenclature and etiopathogenesis of EPS, describe the multimodality imaging appearances of EPS, including differentiating its features from those of other conditions mimicking EPS, and give an overview of management options. Online DICOM image stacks are available for this article. ©RSNA, 2018.

A composite position independent monitor of reactor fuel irradiation using Pu, Cs, and Ba isotope ratios.

When post-irradiation materials from the nuclear fuel cycle are released to the environment, certain isotopes of actinides and fission products carry signatures of irradiation history that can potentially aid a nuclear forensic investigation into the material's provenance. In this study, combinations of Pu, Cs, and Ba isotope ratios that produce position (in the reactor core) independent monitors of irradiation history in spent light water reactor fuel are identified and explored. These position independent monitors (PIMs) are modeled for various irradiation scenarios using automated depletion codes as well as ordinary differential equation solutions to approximate nuclear physics models. Experimental validation was performed using irradiated low enriched uranium oxide fuel from a light water reactor, which was sampled at 8 axial positions from a single rod. Plutonium, barium and cesium were chemically separated and isotope ratio measurements of the separated solutions were made by quadrupole and multi-collector inductively coupled mass spectrometry (Cs and Pu, respectively) and thermal ionization mass spectrometry (Ba). The effect of axial variations in neutron fluence and energy spectrum are evident in the measured isotope ratios. Two versions of a combined Pu and Cs based PIM are developed. A linear PIM model, which can be used to solve for irradiation time is found to work well for natural U fuel with <10% 240Pu and known or short cooling times. A non-linear PIM model, which cannot be solved explicitly for irradiation time without additional information, can nonetheless still group samples by irradiation history, including high burnup LEU fuel with unknown cooling time. 137Ba/138Ba is also observed to act as a position independent monitor; it is nearly single valued across the sampled fuel rod, indicating that samples sharing an irradiation history (same irradiation time and cooling time) in a reactor despite experiencing different neutron fluxes will have a common 137Ba/138Ba ratio. Modeling of this Ba PIM shows it increases monotonically with irradiation and cooling time, and a confirmatory first order analytical solution is also presented.

Distal Esophageal Spasm: A Review.

Distal esophageal spasm is a rare motility disorder presenting principally with nonobstructive dysphagia and noncardiac chest pain. In symptomatic patients, the manometric diagnosis is made when >10% of the wet swallows have simultaneous and/or premature contractions intermixed with normal peristalsis. We characterize manometry and barium as complementary diagnostic approaches, and given the intermittent nature of the disorder, one should be always aware that it is almost impossible to rule out spasm. Treatment is difficult; we propose an approach beginning with the least invasive intervention.

Stenosis of gastric sleeve after laparoscopic sleeve gastrectomy: clinical, radiographic and endoscopic findings.

OBJECTIVE: To determine the clinical, radiographic, and endoscopic findings of sleeve stenosis after sleeve gastrectomy and to correlate treatment with outcomes. METHODS: We identified 43 patients who underwent barium studies to evaluate upper GI symptoms after laparoscopic sleeve gastrectomy. The clinical, radiographic, and endoscopic findings were reviewed and correlated with treatment and outcomes. RESULTS: 26 patients (60%) had sleeve stenoses. All stenoses appeared as short segments of smooth, tapered narrowing, with a mean length of 8.0 mm and mean width of 7.5 mm, and 24 (92%) were located in the proximal or distal third of the sleeve. 23 patients (88%) had upstream dilation, and 1 (4%) had retained food proximal to the stenosis. 23 (70%) of 33 patients with obstructive symptoms and 3 (30%) of 10 without obstructive symptoms had sleeve stenoses. Endoscopy revealed sleeve stenosis in 8 (67%) of 12 patients with radiographic stenosis. Endoscopic dilation resulted in improvement/resolution of symptoms in seven (88%) of 8 patients. CONCLUSION: Sleeve stenosis after sleeve gastrectomy was characterized radiographically by a short segment of smooth, tapered narrowing, typically in the proximal or distal third of the sleeve. Approximately, 70% of patients with obstructive symptoms and 30% with non-obstructive symptoms had sleeve stenosis. One-third of radiographically diagnosed stenoses were not seen at endoscopy. The barium study, therefore, is a useful test for sleeve stenosis in patients with obstructive or nonobstructive symptoms after sleeve gastrectomy. Advances in knowledge: This article describes the appearance and location of sleeve stenoses after laparoscopic sleeve gastrectomy and the clinical presentation and treatment options for these patients.

Oesophageal dysphagia: a stepwise approach to diagnosis and management.

Dysphagia is a common symptom in the general population. Incidence varies depending on the specific definition used. A good medical history is vital for distinguishing true oesophageal dysphagia from oropharyngeal dysphagia or other causes. Oesophageal dysphagia is a so-called red flag alarm symptom requiring oesophagogastroduodenoscopy. However, even after investigations including oesophagogastroduodenoscopy (with biopsy), barium swallow, and oesophageal manometry, no obstructive cause may be found. This Review suggests an algorithm of history-taking and investigation to allow the causes of non-obstructive dysphagia to be identified, including functional dysphagia. The Review then discusses management strategies and outcomes for functional dysphagia.

Thyroid monitoring of adults and children after reactor accidents with a new dose rate measurement device.

A specialized dose rate measurement device that was designed for monitoring the thyroid dose of children and adults after reactor accidents was tested. In measurements with neck phantoms and a human patient, the device was found to be capable of measuring the required low dose rates, even within increased ambient radiation. It is suitable for the application in emergency care centers.

Evaluation of an early warning system for airborne radionuclides.

An early warning system for detection of increased levels of radioactivity in outdoor air was operative between 2004 and 2011 at the Swedish air sampling stations. The system consisted of a low resolution detector (NaI), positioned directly behind the filter and measurement of the accumulated radioactivity were performed continuously. An evaluation of the data collected during the period is presented with emphasis on natural occurring radionuclides and their influence on the detectability of anthropogenic radionuclides.

Determination of uncertainties associated to the in vivo measurement of iodine-131 in the thyroid.

Intakes of radionuclides can be estimated through in vivo measurements, and the uncertainties associated to the measured activities should be clearly stated in monitoring program reports. This study aims to evaluate the uncertainties of in vivo monitoring of iodine 131 in the thyroid. The reference values for high-energy photons are based on the IDEAS Guide. Measurements were performed at the In Vivo Monitoring Laboratory of the Institute of Radiation Protection and Dosimetry (IRD) and at the Internal Dosimetry Laboratory of the Regional Center of Nuclear Sciences (CRCN-NE). In both institutions, the experiment was performed using a NaI(Tl) 3''3″ scintillation detector and a neck-thyroid phantom. Scattering factors were calculated and compared in different counting geometries. The results show that the technique produces reproducibility equivalent to the values suggested in the IDEAS Guide and measurement uncertainties is comparable to international quality standards for this type of in vivo monitoring.

(Mis)use of (133)Ba as a calibration surrogate for (131)I in clinical activity calibrators.

Using NIST-calibrated solutions of (131)Ba and (131)I in the 5mL NIST ampoule geometry, measurements were made in three NIST-maintained Capintec activity calibrators and the NIST Vinten 671 ionization chamber to evaluate the suitability of using (133)Ba as a calibration surrogate for (131)I. For the Capintec calibrators, the (133)Ba response was a factor of about 300% higher than that of the same amount of (131)I. For the Vinten 671, the Ba-133 response was about 7% higher than that of (131)I. These results demonstrate that (133)Ba is a poor surrogate for (131)I. New calibration factors for these radionuclides in the ampoule geometry for the Vinten 671 and Capintec activity calibrators were also determined.

Efficiency of barium removal from radioactive waste water using the combination of maghemite and titania nanoparticles in PVA and alginate beads.

In this paper, both maghemite (γ-Fe2O3) and titanium oxide (TiO2) nanoparticles were synthesized and mixed in various ratios and embedded in PVA and alginate beads. Batch sorption experiments were applied for removal of barium ions from aqueous solution under sunlight using the beads. The process has been investigated as a function of pH, contact time, temperature, initial barium ion concentration and TiO2:γ-Fe2O3 ratios (1:10, 1:60 and 1). The recycling attributes of these beads were also considered. Furthermore, the results revealed that 99% of the Ba(II) was eliminated in 150min at pH 8 under sunlight. Also, the maghemite and titania PVA-alginate beads can be readily isolated from the aqueous solution after the process and reused for at least 7 times without significant losses of their initial properties. The reduction of Ba(II) with maghemite and titania PVA-alginate beads fitted the pseudo first order and second order Langmuir-Hinshelwood (L-H) kinetic model.