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Urolithiasis
Published in Karl H. Pang, Nadir I. Osman, James W.F. Catto, Christopher R. Chapple, Basic Urological Sciences, 2021
Infection stones: (historically known as struvite stone): 5−10% of all calculi.Magnesium, ammonium, phosphate components
Renal calculi
Published in Mark Davenport, James D. Geiger, Nigel J. Hall, Steven S. Rothenberg, Operative Pediatric Surgery, 2020
Eleni Papageorgiou, Naima Smeulders
Until recently, most renal calculi in children were considered infective in origin. The organisms most commonly associated with infective calculi are the urea-splitting Proteus spp. and Escherichia coli. Infective calculi are usually soft, contain organic matrix, and opacify poorly. They usually consist of calcium, magnesium, and ammonium phosphate. Today, the epidemiology appears to have changed. In a review from our institution (1993–2015) a metabolic abnormality was detected in 34% of children with urolithiasis; 22% of stones were classified as infective, while in 44% of patients no etiological factor could be identified (Figure 72.1a). Hypercalciuria (52%) was the most common metabolic abnormality, followed by cystinuria (22%), hyperoxaluria (21%), unclassified hypercalcemia (2%), abnormalities in the purine metabolism (autosomal recessive adenine phosphoribosyl transferase deficiency, 2%), and hyperuricosuria (1%) (Figure 72.1b).
High-Performance Liquid Chromatography
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Joel J. Kirschbaum, Adorjan Aszalos
After oral administration, pyrazinamide is hydrolyzed to pyrazinoic acid, which was determined at concentrations of 1–10 μg/ml in 300 μl of serum with its metabolite, 5-hydroxypyrazinoic acid [80]. An amino column and precolumn, 40 × 4.6 mm, were used with a mobile phase of 0.01 M ammonium phosphate buffer, pH 4.2-acetonitrile (30:70) flowing at 2 ml/min through a 254 nm detector.
Stability screening of pharmaceutical cocrystals
Published in Pharmaceutical Development and Technology, 2021
Kenneth C. Waterman, Alisa K. Waterman, Teslin M. Botoy, Jane Li, Fenghe Qiu, Michael Hawley
All cocrystals and un-complexed drugs were provided by Boehringer Ingelheim Pharmaceuticals, Inc. microcrystalline cellulose, MCC (Avicel® PH 102 NF) was received from Mutchler (Harrington Park, NJ). Sodium hydroxide, D- lactose and ammonium phosphate dibasic were purchased from Fisher Scientific (Fair Lawn, NJ). Sodium starch glycolate (SSG), magnesium stearate (MgSt), and croscarmellose sodium (CCS) were purchased from Spectrum (Gardena, CA). Hydroxypropyl cellulose, HPC (Klucel™ EF Pharm), was supplied by Ashland (Wilmington, DE).Mannitol, ammonium dihydrogen phosphate, ammonium acetate, acetonitrile (ACN), phosphoric acid, and povidone, PVP (K30), were purchased from Millipore Sigma (St. Louis, MO). YMC Pack Pro C8 100 × 3 mm 3.0 µm column was purchased from YMC (Japan). Waters X-Bridge C18, 100 × 3.0 mm, 3.5 µm, and X-Bridge Shield RP18 100 × 3.0 mm 3.5 µm columns were purchased from Waters (USA). Nylon syringe filters (0.45 µm) were purchased from Omicron Scientific (Alpharetta, GA). A Waters 2695 separation module with a 2996 PDA detector was used (Milford, MA) with the HPLC data analyzed using Empower 3 software.
Application of zinc oxide and sodium alginate for biofouling mitigation in a membrane bioreactor treating urban wastewater
Published in Biofouling, 2020
Fatemeh Sokhandan, Maryam Homayoonfal, Fatemeh Davar
To conduct the test in the membrane bioreactor, urban wastewater sludge was prepared from the treatment plant in south of Isfahan (Iran) and was fed for 60 days with a COD of 1000 mg l−1, in order to adapt to the laboratory conditions. Activated sludge was fed with an organic loading rate (OLR) of 0.07 kgCOD m−3 day with an F/M ratio of 0.95 l day−1. In this reactor, the pH was fixed at 9 ± 0.2. The air diffusers (spargers) placed under the membrane module, in addition to air scouring and mixing, would increase the dissolved oxygen (DO) to keep it at levels of 4 ± 0.7 mg l−1. The solid retention time (SRT) was also fixed and equal to infinity in the operation period (35 days). The hydraulic retention time (HRT) was about 20 h and the operational pressure was also a constant 0.5 bar. Ammonium nitrate, ammonium phosphate, and glucose were added as the feed to the activated sludge for supplying nitrogen, phosphorus, and carbon with 1, 5, and 100 ratios.
Preparation and characterisation of flame retardant encapsulated with functionalised silica-based shell
Published in Journal of Microencapsulation, 2018
Doan-Trang Hoang, Diane Schorr, Véronic Landry, Pierre Blanchet, Stéphanie Vanslambrouck, Christian Dagenais
Despite many advantages, IFR coatings (but also some non-intumescent types) are extremely sensitive to the moisture in the air, and its effectiveness is reduced under long time exposure to high humidity conditions. This is due to the hygroscopic character of the flame retardant additives (Truax 1956, Goldsmith 2011, Mariappan 2016). Ammonium polyphosphate (APP), one of the principal compounds in IFR coatings, tends to hydrolyse to water-soluble mono-ammonium phosphate when exposed to relatively high humidity. Inorganic salts from the intumescent coating migrate towards the surface of the polymer matrix, which deteriorates fire protection performance (Daniliuc et al.2012, Qu et al.2012, Deng et al.2014). The hydrophilic elements in IFR coating cause non-uniform of the charred structure, which reduces the thermal stability and interaction of the components in the coating and leads to the loss of mechanical strength and oxidation resistance of char at high temperature (Lv et al.2009, Mariappan 2016). For this reason, the IFR coatings are not widely used in the exterior wood siding. It is also problematic for some indoor uses (relative humidity <70%) (Daniliuc et al.2012).