Compensatory Mechanisms in Acid–Base Disorders
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
Titratable acidity refers to the hydrogen ions bound to filtered buffers in urine, and it is equal to the amount of alkali (NaOH) required to titrate the urine to a pH of 7.4. Urinary titratable acidity is due to the conversion of monohydrogen phosphate to dihydrogen phosphate in the tubule. At the maximal urine acidity of 4.5, all the urinary phosphate is in the form of dihydrogen phosphate. After all the bicarbonate ions in the tubular fluid are reabsorbed, excess H+ ions in the tubular fluid combine with monohydrogen phosphate to form dihydrogen phosphate. A bicarbonate ion is added to peritubular capillary blood for each dihydrogen phosphate ion produced. Other filtered buffers in the tubular fluid, including creatinine, β-hydroxybutyrate and sulphates, contribute only a minor extent to titratable acidity. The proximal tubule is the chief site for the formation of titratable acidity (Figure 48.3). The kidney can excrete H+ ions using the phosphate buffer system at a rate of 40 mmol per day. However, the availability of phosphate cannot be easily increased to increase acid excretion.
Diagnostic methods in malaria
David A Warrell, Herbert M Gilles in Essential Malariology, 2017
Stock solutions of Giemsa stain must always be diluted by mixing an appropriate amount of the stain with distilled neutral or slightly alkaline water. Buffered saline is preferred because it provides a cleaner background and a better preservation of parasite morphology. A buffer solution that gives a pH of 7.2 is prepared as follows: Potassium dihydrogen phosphate KH2P04): 0.7 gDisodium hydrogen phosphate (Na2HP04): 1.0 gDistilled water: 1 L.
Acid–base physiology
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2015
Titratable acidity refers to the hydrogen ions bound to filtered buffers in urine, and it is equal to the amount of alkali (NaOH) required to titrate the urine to a pH of 7.4. Urinary titratable acidity is due to the conversion of monohydrogen phosphate to dihydrogen phosphate in the tubule. At the maximal urine acidity of 4.5, all the urinary phosphate is in the form of dihydrogen phosphate. After all the bicarbonate ions in the tubular fluid are reabsorbed, excess H+ ions in the tubular fluid combine with monohydrogen phosphate to form dihydrogen phosphate. A bicarbonate ion is added to peritubular capillary blood for each dihydrogen phosphate ion produced. Other filtered buffers in the tubular fluid, including creatinine, β-hydroxybutyrate and sulphates, contribute only a minor extent to titratable acidity. The proximal tubule is the chief site for the formation of titratable acidity (Figure 8.6).
Plasma protein binding, metabolism, reaction phenotyping and toxicokinetic studies of fenarimol after oral and intravenous administration in rats
Published in Xenobiotica, 2021
Kajal Karsauliya, Ashish Kumar Sonker, Manisha Bhateria, Isha Taneja, Anshuman Srivastava, Manu Sharma, Sheelendra Pratap Singh
FNL (CAS no. 60168-88-9, purity ≥ 98.0%) was procured from Sigma Aldrich (St Louis, MO) whereas, Centchroman (internal standard, IS) was a generous gift from CSIR-Central Drug Research Institute, Lucknow, India. The chemical structures of FNL and IS are represented in Figure 1. Propranolol, ethylenediaminetetraacetic acid (EDTA), ketoconazole, LC grades of acetonitrile and formic acid were supplied by Sigma Aldrich (St. Louis, Germany). Dipotassium hydrogen phosphate anhydrous and potassium dihydrogen phosphate were purchased from Merck Life Sciences Pvt. Ltd (Mumbai, India). Magnesium chloride was procured from Loba Chemie Pvt. Ltd (Mumbai, India). NADPH was procured from SRL Pvt. Ltd (Mumbai, India). Liver microsomes (Catalogue number: RTMCPL (rat liver microsomes) and HMMCPL (human liver microsomes)) and recombinant human CYP450 isoforms (1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4) were purchased from Invitrogen (Thermo Fisher Scientific, Bangalore, India). Milli Q water was obtained from a Millipore gradient water purification system (Millipore India Pvt. Ltd, New Delhi, India). MultiScreen Solvinert Filter Plate (96-well device with 0.45 µm PTFE membranes) were purchased from Millipore Corporation (Milford, CT). Blank plasma was obtained from healthy adult Wistar rats procured from the animal facility of the CSIR-Indian Institute of Toxicology Research, Lucknow, India. For maintenance, experimental studies, euthanasia, and disposal of the carcass, prior approval was taken from Institutional Animal Ethics Committee (IITR/IAEC/03/19). Human blank plasma was offered by healthy volunteers.
Bond strength of zirconia- or polymer-based copings cemented on implant-supported titanium bases – an in vitro study
Published in Biomaterial Investigations in Dentistry, 2021
Eliann Oddbratt, Lisa Hua, Bruno R. Chrcanovic, Evaggelia Papia
The adhesive cement systems used in the present study have an indication for permanent use in clinical practice. The results from the bond strength test showed that the cement system Multilink Hybrid Abutment (MHA) had significant lower value than Panavia V5 (PV5) and Rely X Ultimate (RXU) in general. The bond strength of the adhesive cement system depends on several factors such as micro- and macromechanical retention, chemical retention, dental materials used, type of adhesive resin cement and how the operator handle the materials in the dental laboratory, that is, if the instructions are followed according to the manufacturer [12]. The cement composition influences the bond strength and the adhesive resin cement systems tested contain different filler particles and matrix. The majority of studies reports that the highest retention was achieved when phosphate monomers [13], and more specific 10-methacryloyloxy-decyl dihydrogenphosphate (MDP) were present in the cements’ composition [14,15]. However, MHA is polymerized through auto polymerization which differs from PV5 and RXU, which both are dual polymerized and have been reported to obtain the high bond strength even after thermocycling [16].
One-step preparation of ibuprofen fast- and sustained-release formulation by electrospinning with improved efficacy and reduced side effect
Published in Pharmaceutical Development and Technology, 2020
Xin Che, Juan Xue, Jianfeng Zhang, Xiangbo Yang, Lihong Wang
The electrostatic spinner used in the experiments was purchased from Yongkangleye Ltd. equipped with a high-voltage DC supply, rotate collector, and two syringe pumps. The electrical potential applied on the spinneret electrode was 30 kV. The collector was covered with aluminum foil to collect the NFs. The distance between the spinneret and the receiver was 25 cm, and the experiments were performed at ambient temperature (25 °C). The polymer solutions were pulled out of the syringe needles and dosed by syringe pumps. The dosing rate was 20 ml/h. The solution of fast-release part for electrospinning was 10.0 g ibuprofen in 500 ml 40% PVP ethanol solution. The solution of sustained-release part for electrospinning was 10.0 g ibuprofen in 500 ml 30% HPMC methanol solution. The viscosity of the electrospinning fluids were tested by a Ubbelohde viscosity meter. The surface tension of the electrospinning fluids were determined by a surface tension meter (Sigma 703 D, Finland). The drug loading content within the complex preparation was determined by HPLC using C18 column (15 × 4.6 mm, 5 μm). The mobile phase consisted of methanol—0.1 mol/l potassium dihydrogen phosphate solution—phosphoric acid (700: 300: 0.1). Before the analysis, the complex preparation was dissolved in methanol–dichloromethane (1:1), and diluted by mobile phase. In order to carry out the comparing study, an ibuprofen preparation prepared by co-precipitation was prepared. The solution used for co-precipitated ibuprofen preparation was the same as the solution of the fast-release part.
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