Thermodynamic description of Be(II) solubility and hydrolysis in acidic to hyperalkaline NaCl and KCl solutions

The solubility of Be(II) is investigated in carbonate-free dilute to concentrated HCl–NaCl–NaOH, KCl–KOH, NaOH and KOH solutions. Undersaturation experiments were performed under Ar atmosphere at T= (22 ± 2) °C. XRD, XPS, SEM and quantitative chemical analysis confirm that α-Be(OH)$_{2}$(cr) is the solid phase controlling the solubility in all evaluated systems. No transformation of α-Be(OH)$_{2}$(cr) to β-Be(OH)$_{2}$(cr) or ternary solid phases Na/K–Be(II)–OH(s) is observed in the investigated systems within the timeframe of this study (t ≤ 600 days). An amphoteric solubility behaviour of Be(II) is observed with a solubility minimum at pH$_{m}$ ≈ 9.5 (with [Be(II)] ≈ 10$^{-6.8}$M), regardless of the ionic strength. The combination of solubility data determined in acidic pH$_{m}$ conditions and the hydrolysis scheme reported in the literature for cationic hydrolysis species of Be(II) is used for the determination of the solubility constant of α-Be(OH)$_{2}$(cr), log *K°$_{s,0}$ = (6.9 ± 0.4). Slope analysis of the solubility data in alkaline to hyperalkaline conditions and $^{9}$Be NMR support the predominance of the monomeric hydrolysis species Be(OH)$_{2}$(aq), Be(OH)$_{3}$– and Be(OH)$_{4}$$^{2-}$ within the strongly alkaline pH$_{m}$-conditions relevant in cementitious systems. The comprehensive solubility dataset collected within this study in combination with extensive solid and aqueous phase characterization allow the development of a complete chemical, thermodynamic and (SIT) activity model for the system Be$^{2+}$–Na$^{+}$–K$^{+}$–H$^{+}$–Cl$^{-}$–OH$^{-}$–H$_{2}$O(l). This model provides an accurate and robust tool for the evaluation of Be(II) solubility and speciation in a diversity of geochemical conditions, including source term calculations of beryllium in the context of the nuclear waste disposal Safety Case

Predictors of recurrence after surgical treatment of idiopathic progressive subglottic stenosis

Predittori di recidiva dopo trattamento chirurgico delle stenosi idiopatiche subglottiche progressive. RIASSUNTO: La stenosi idiopatica subglottica progressiva rappresenta una rara causa di restringimento della laringe. La resezione parziale con successiva anastomosi pu\uf2 potenzialmente essere curativa; nonostante ci\uf2 alcuni pazienti richiedono un numero elevato di ritrattamenti e possono sviluppare disfonia e disfagia in seguito all\u2019intervento. In questo studio abbiamo investigato i fattori di rischio per il ritrattamento e abbiamo valutato l\u2019impatto della resezione crico-tracheale sui parametri funzionali. \uc8 stata condotta un\u2019analisi multicentrica retrospettiva su 44 pazienti di sesso femminile (et\ue0 media 52,6 \ub1 13,1 anni), sottoposti a resezione crico-tracheale tra il 2002 e il 2016. Gli esiti funzionali sono stati valutati utilizzando la scala \u201cvie aeree-dispnea-voce-disfagia\u201d dove ognuno di questi parametri \ue8 stato valutato con un punteggio da 1 a 5, ove 1 esprime una funzione normale e 5 una funzione completamente compromessa. L\u2019esistenza di trattamenti pregressi, il grado di stenosi, il sito della stenosi, la presenza di comorbidit\ue0 delle vie aeree, l\u2019et\ue0 e la lunghezza del segmento resecato sono stati testati all\u2019analisi bivariata e multivariata come predittori di complicanze e di trattamenti aggiuntivi. Il trattamento ha permesso la decannulazione del paziente nel 97,3% dei casi. L\u2019indice di dispnea \ue8 migliorato (variazione media 1,4 \ub1 1,0; p < 0,001), mentre quelli relativi alla voce e alla deglutizione sono peggiorati (variazione media 1,6 \ub1 0,9 and 0,5 \ub1 0,7, rispettivamente; p < 0,001). I pazienti affetti da comorbidit\ue0 delle vie aeree hanno presentato un tasso pi\uf9 alto di complicanze (p < 0,05). La lunghezza del segmento resecato ha dimostrato una correlazione diretta con il numero dei ritrattamenti (R = 0,52; p < 0,01). All\u2019analisi multivariata, le complicazioni post-operatorie erano predette dall\u2019esistenza di comorbidit\ue0 e dallo stadio di malattia (p < 0,05); il numero dei ritrattamenti era associato alla lunghezza del tratto resecato (p < 0,05) e all\u2019applicazione di Mitomicina C (p < 0,001). La resezione crico-tracheale offre dei buoni risultati funzionali per la cura della stenosi idiopatica subglottica progressiva, in termini di perviet\ue0 delle vie aeree. I nostri dati suggeriscono che i pazienti affetti da comorbidit\ue0 possono presentare un\u2019incidenza pi\uf9 alta di complicazioni. Inoltre, resezioni chirurgiche pi\uf9 estese sembrano essere associate all\u2019incidenza e al numero dei ritrattamenti. Al contrario, l\u2019applicazione di sostanza anti-proliferativa non sembra essere utile nella prevenzione delle recidive.Idiopathic progressive subglottic stenosis is a rare cause of tracheal narrowing. Partial cricotracheal resection and anastomosis can cure idiopathic stenosis, even if some patients may require multiple interventions and experience voice and swallowing deterioration. We investigated risk factors for retreatment and assessed the impact of crico-tracheal resection on functional parameters. We conducted a retrospective multicentric study on 44 female patients (mean age 52.6 \ub1 13.1 years) affected by idiopathic stenosis and treated by crico-tracheal resection between 2002 and 2016. Functional outcomes after crico-tracheal resection were assessed by the airway-dyspnoea-voice-swallowing score (range 1-5, with "1" expressing normal and "5" completely altered function). Previous treatments, grade of stenosis, site, airway comorbidities, age and resection length were tested as predictors of postoperative complications and number of additional treatments, using bivariate and multivariate analysis. The overall decannulation rate was 97.3%. The dyspnoea score improved (mean variation 1.4 \ub1 1.0; p < 0.001), while voice and swallowing were negatively affected (mean variation 1.6 \ub1 0.9 and 0.5 \ub1 0.7, respectively; p < 0.001). Airway comorbidities were associated with a higher rate of complications (p < 0.05). Retreatments were more frequent in patients with postoperative complications (p < 0.05). The length of resection correlated with the number of subsequent treatments (R = 0.52; p < 0.01). At multivariate analysis, post-operative complications were predicted by comorbidities and disease stage (p < 0.05); number of retreatments was linked to the length of resection (p < 0.05) as well as with the application of mitomycin C (p < 0.001). Crico-tracheal resection for idiopathic progressive subglottic stenosis offers good functional results in terms of airway patency. These data suggest that a higher complication rate can be expected in patients affected by comorbidities. Moreover, more extensive surgical resection seems to be associated with the occurrence and number of subsequent retreatments. On the contrary, the local application of an anti-proliferative drug does not seem to be of use in preventing recurrences

Management of peripheral facial nerve palsy

Peripheral facial nerve palsy (FNP) may (secondary FNP) or may not have a detectable cause (Bell’s palsy). Three quarters of peripheral FNP are primary and one quarter secondary. The most prevalent causes of secondary FNP are systemic viral infections, trauma, surgery, diabetes, local infections, tumor, immunological disorders, or drugs. The diagnosis of FNP relies upon the presence of typical symptoms and signs, blood chemical investigations, cerebro-spinal-fluid-investigations, X-ray of the scull and mastoid, cerebral MRI, or nerve conduction studies. Bell’s palsy may be diagnosed after exclusion of all secondary causes, but causes of secondary FNP and Bell’s palsy may coexist. Treatment of secondary FNP is based on the therapy of the underlying disorder. Treatment of Bell’s palsy is controversial due to the lack of large, randomized, controlled, prospective studies. There are indications that steroids or antiviral agents are beneficial but also studies, which show no beneficial effect. Additional measures include eye protection, physiotherapy, acupuncture, botulinum toxin, or possibly surgery. Prognosis of Bell’s palsy is fair with complete recovery in about 80% of the cases, 15% experience some kind of permanent nerve damage and 5% remain with severe sequelae

Pathologies of the larynx and trachea in childhood

Pathologies in the larynx and trachea in the pediatric age can be characterized in 4 main groups: airway stenosis, acute infections, benign neoplasia and foreign body aspiration. In this review main diagnostic strategies and therapeutic options are presented.Laryngomalazia is the most frequent condition of supraglottic stenosis. The term supraglottoplasty summarizes all different techniques used for it's repair using an endoscopic approach.Glottic stenosis is rare in children. Usually a compromise between voice preservation and airway restoration has to be sought. Type of reconstruction and timing are varying considerably in individual cases, endoscopic approaches should be preferred.Subglottic stenosis remains the largest group in paediatric airway pathology, with cicatrial stenosis being predominant. Today, cricotracheal resection is the most successful treatment option, followed by the classical laryngotracheal reconstruction with autologous cartilage. In early infancy subglottic stenosis is particularly demanding. Endoscopic treatment is possible in selected patients, but open reconstruction is superior in more severe cases.Tracheostomy is not a safe airway in early infancy, it's indication should be strict.Foreign body aspiration needs to be managed according to a clear algorhythm.Recurrent respiratory papillomatosis should be treated with emphasis on function preservation. The role of adjuvant medication remains unclear.Infectious diseases can be managed conservatively by a pediatrician in the majority of cases

Grass, Legume and Forb Cultivation

Photograph of Sericea lespedeza. The grass is cut and raked in windrows on 4 acres of an idle, cultivated field, which was seeded at the rate of 25 pounds per acre on June 10, 1942 with a cyclone seeder. The field was flattened, disked and harrowed. Three and one half acres were fertilized with 200 pounds of 20% phosphate per acre and the seed bed packed with a cultipacker. Seeds were covered with a second rolling of the cultipacker. A severe drought in 1943 prevented all but one hay crop. Freddie Brown, the District Supervisor, estimated that he harvested 1.5 tons of hay per acre for a total of 6 tons. One hay crop in 1944 yielded 8 tons. A seed crop will be harvested later this year. One-half acre was left unphosphated at the time of seeding for a field test. The area phosphate yielded 50% more hay than the untreated area. Soil is very infertile. Adjacent land sodded to Bermuda grass in June and July, 1942 is living but making no growth whatever. L to R: Maynard Collins, Freddie Brown and John Moberly. OK-8960