Removal of Direct Red 12B from aqueous medium by ZnCl2 activated Jatropha husk carbon: Adsorption dynamics and equilibrium studies

Adsorption isotherms and kinetics of adsorption of Direct Red 12B (DR 12B) on zinc chloride activated carbon prepared from Jatropha husk (ZAJHC) have been determined from batch tests. Effects of contact time, initial dye concentration, initial pH, adsorbent dose and solution temperature have been investigated. The equilibrium data are best represented by Langmuir isotherm model, showing monolayer adsorption capacity (Qo) of 39 mg g-1. The kinetic data are fitted to pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and are found to follow closely the pseudo-first-order kinetic model. Thermodynamic parameters such as standard enthalpy (∆Ho), standard entropy (∆So) and standard free energy (∆Go) have been evaluated. The adsorption interaction is found to be endothermic in nature. Acidic pH is favourable for the adsorption of DR 12B. Desorption studies show that chemisorption seems to be the major mode of adsorption. ZAJHC is shown to be a promising adsorbent for removal of DR 12B from aqueous solutions

Removal of Direct Red 12B from aqueous medium by ZnCl₂ activated <i>Jatropha</i> husk carbon: Adsorption dynamics and equilibrium studies

73-81Adsorption isotherms and kinetics of adsorption of Direct Red 12B (DR 12B) on zinc chloride activated carbon prepared from Jatropha husk (ZAJHC) have been determined from batch tests. Effects of contact time, initial dye concentration, initial pH, adsorbent dose and solution temperature have been investigated. The equilibrium data are best represented by Langmuir isotherm model, showing monolayer adsorption capacity (Qo) of 39 mg g-1. The kinetic data are fitted to pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and are found to follow closely the pseudo-first-order kinetic model. Thermodynamic parameters such as standard enthalpy (∆Ho), standard entropy (∆So) and standard free energy (∆Go) have been evaluated. The adsorption interaction is found to be endothermic in nature. Acidic pH is favourable for the adsorption of DR 12B. Desorption studies show that chemisorption seems to be the major mode of adsorption. ZAJHC is shown to be a promising adsorbent for removal of DR 12B from aqueous solutions

Use of digital images in the assessment and treatment of pressure ulcers in patients with spinal injuries in community settings.

We conducted a retrospective review of the digital images in the clinical records of 50 patients with pressure ulcers. Ten nurses independently assessed one image from each patient. There was a total of 414 responses from the nurses about the stage and location of the ulcers (83% response rate). The average agreement about the stage and location of the ulcers was 85%. The overall agreement declined as the stage of the ulcer increased. The average agreement regarding the wound descriptors was: necrosis 85%, granulation tissue 81%, ischaemia 83%, cellulitis /infection 69%, erythema 68%. Almost all nurses felt the need to change the current management of the wound (460 responses, or 92%). The nurses judged that most digital images were of good quality (17%) or very good quality (79%). The present study suggests that a high percentage of assessments for patients currently travelling to specialist clinics could be performed in the community using digital images and telemedicine

Diagnostic accuracy of a two-stage model for detecting obstructive sleep apnoea in chronic tetraplegia

BackgroundObstructive sleep apnoea (OSA) is highly prevalent in people with spinal cord injury (SCI). Polysomnography (PSG) is the gold-standard diagnostic test for OSA, however PSG is expensive and frequently inaccessible, especially in SCI. A two-stage model, incorporating a questionnaire followed by oximetry, has been found to accurately detect moderate to severe OSA (MS-OSA) in a non-disabled primary care population. This study investigated the accuracy of the two-stage model in chronic tetraplegia using both the original model and a modified version for tetraplegia.MethodsAn existing data set of 78 people with tetraplegia was used to modify the original two-stage model. Multivariable analysis identified significant risk factors for inclusion in a new tetraplegia-specific questionnaire. Receiver operating characteristic (ROC) curve analyses of the questionnaires and oximetry established thresholds for diagnosing MS-OSA. The accuracy of both models in diagnosing MS-OSA was prospectively evaluated in 100 participants with chronic tetraplegia across four international SCI units.ResultsInjury completeness, sleepiness, self-reported snoring and apnoeas were included in the modified questionnaire, which was highly predictive of MS-OSA (ROC area under the curve 0.87 (95% CI 0.79 to 0.95)). The 3% oxygen desaturation index was also highly predictive (0.93 (0.87–0.98)). The two-stage model with modified questionnaire had a sensitivity and specificity of 83% (66–93) and 88% (75–94) in the development group, and 77% (65–87) and 81% (68–90) in the validation group. Similar results were demonstrated with the original model.ConclusionImplementation of this simple alternative to full PSG could substantially increase the detection of OSA in patients with tetraplegia and improve access to treatments.Trial registration numberResults, ACTRN12615000896572 (The Australian and New Zealand Clinical Trials Registry) and pre-results, NCT02176928 (clinicaltrials.gov)