30 research outputs found
Competitive Adsorption of a Multi-functional Amine and Phenol Surfactant with Ethanol on Hematite from Non-Aqueous Solution
Surfactants, which contain phenol and amine groups, are commonly used in industries to protect metallic surfaces, and their efficiency depends strongly on factors such as pressure and temperature, solvent properties, and the presence of other surfactants in the system. In this work, we present a molecular simulation study of the competitive adsorption between a multifunctional phenol and amine surfactant model and ethanol at the oil/solid interface formed between iso-octane and a model hematite (α-Fe2O3) slab. We show that the surfactant strongly adsorbs at the iso-octane/hematite interface in the absence of ethanol at moderate temperatures. As the concentration of ethanol is increased, the ethanol molecules compete effectively for the adsorption sites on the iron oxide surface. This competition drives the surfactant molecules to remain in the bulk solution, while ethanol forms ordered and strongly coordinated layers at the oil/solid interface, despite the well-known complete miscibility of ethanol in iso-octane in bulk under standard conditions. Potential of mean force calculations show that the free energy of adsorption of the surfactant is approximately two times larger than that for a single ethanol molecule, but the simulations also reveal that a single surfactant chain needs to displace up to five ethanol molecules to adsorb onto the surface. The end result is more favorable ethanol adsorption which agrees with the experimental analysis of similar oil/iron oxide systems also reported in this work.Industr
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Adsorption of 4-n-Nonylphenol, Carvacrol, and Ethanol onto Iron Oxide from Nonaqueous Hydrocarbon Solvents.
The adsorption of 4-n-nonylphenol (4NP), carvacrol, and ethanol onto the surface of iron oxide from nonaqueous solutions is presented. It is found that adsorption of 4NP from alkanes is strong and proceeds to monolayer formation, where the molecules are essentially "upright". However, at high relative concentrations, ethanol successfully out-competes 4NP for the iron oxide surface. Estimates of the enthalpy and entropy of binding of 4NP were found to be exothermic and entropically disfavored. Sum frequency generation vibrational spectroscopy data indicate some evidence of binding through a phenolate anion, despite the nonpolar, nonaqueous solvent. Carvacrol is also found to adsorb as a monolayer where the molecules are lying "flat". The adsorption of ethanol onto iron oxide from dodecane was investigated through the use of quantitative NMR, which is a convenient analytical technique for measuring adsorption isotherms. It was concluded that ethanol does not form adsorbed monolayers on the surface. Instead, it partitions onto the surface as a surface-enhanced local phase separation related to its poor solubility in alkane solvents.B
Preparing for responsive management versus preparing for renal dialysis in multimorbid older people with advanced chronic kidney disease (Prepare for Kidney Care): study protocol for a randomised controlled trial.
BackgroundChronic kidney disease (CKD) prevalence is steadily increasing, in part due to increased multimorbidity in our aging global population. When progression to kidney failure cannot be avoided, people need unbiased information to inform decisions about whether to start dialysis, if or when indicated, or continue with holistic person-centred care without dialysis (conservative kidney management). Comparisons suggest that while there may be some survival benefit from dialysis over conservative kidney management, in people aged 80 years and over, or with multiple health problems or frailty, this may be at the expense of quality of life, hospitalisations, symptom burden and preferred place of death. Prepare for Kidney Care aims to compare preparation for a renal dialysis pathway with preparation for a conservative kidney management pathway, in relation to quantity and quality of life in multimorbid, frail, older people with advanced CKD.MethodsThis is a two-arm, superiority, parallel group, non-blinded, individual-level, multi-centre, pragmatic trial, set in United Kingdom National Health Service (NHS) kidney units. Patients with advanced CKD (estimated glomerular filtration rate < 15 mL/min/1.73 m2, not due to acute kidney injury) who are (a) 80 years of age and over regardless of frailty or multimorbidity, or (b) 65–79 years of age if they are frail or multimorbid, are randomised 1:1 to ‘prepare for responsive management’, a protocolised form of conservative kidney management, or ‘prepare for renal dialysis’. An integrated QuinteT Recruitment Intervention is included. The primary outcome is mean total number of quality-adjusted life years during an average follow-up of 3 years. The primary analysis is a modified intention-to-treat including all participants contributing at least one quality of life measurement. Secondary outcomes include survival, patient-reported outcomes, physical functioning, relative/carer reported outcomes and qualitative assessments of treatment arm acceptability. Cost-effectiveness is estimated from (i) NHS and personal social services and (ii) societal perspectives.DiscussionThis randomised study is designed to provide high-quality evidence for frail, multimorbid, older patients with advanced CKD choosing between preparing for dialysis or conservative kidney management, and healthcare professionals and policy makers planning the related services.Trial registrationISRCTN, ISRCTN17133653 (https://doi.org/10.1186/ISRCTN17133653). Registered 31 May 2017.<br/
Canakinumab relieves symptoms of acute flares and improves health-related quality of life in patients with difficult-to-treat Gouty Arthritis by suppressing inflammation: results of a randomized, dose-ranging study
INTRODUCTION: We report the impact of canakinumab, a fully human anti-interleukin-1β monoclonal antibody, on inflammation and health-related quality of life (HRQoL) in patients with difficult-to-treat Gouty Arthritis.
METHODS: In this eight-week, single-blind, double-dummy, dose-ranging study, patients with acute Gouty Arthritis flares who were unresponsive or intolerant to--or had contraindications for--non-steroidal anti-inflammatory drugs and/or colchicine were randomized to receive a single subcutaneous dose of canakinumab (10, 25, 50, 90, or 150 mg) (N = 143) or an intramuscular dose of triamcinolone acetonide 40 mg (N = 57). Patients assessed pain using a Likert scale, physicians assessed clinical signs of joint inflammation, and HRQoL was measured using the 36-item Short-Form Health Survey (SF-36) (acute version).
RESULTS: At baseline, 98% of patients were suffering from moderate-to-extreme pain. The percentage of patients with no or mild pain was numerically greater in most canakinumab groups compared with triamcinolone acetonide from 24 to 72 hours post-dose; the difference was statistically significant for canakinumab 150 mg at these time points (P < 0.05). Treatment with canakinumab 150 mg was associated with statistically significant lower Likert scores for tenderness (odds ratio (OR), 3.2; 95% confidence interval (CI), 1.27 to 7.89; P = 0.014) and swelling (OR, 2.7; 95% CI, 1.09 to 6.50, P = 0.032) at 72 hours compared with triamcinolone acetonide. Median C-reactive protein and serum amyloid A levels were normalized by seven days post-dose in most canakinumab groups, but remained elevated in the triamcinolone acetonide group. Improvements in physical health were observed at seven days post-dose in all treatment groups; increases in scores were highest for canakinumab 150 mg. In this group, the mean SF-36 physical component summary score increased by 12.0 points from baseline to 48.3 at seven days post-dose. SF-36 scores for physical functioning and bodily pain for the canakinumab 150 mg group approached those for the US general population by seven days post-dose and reached norm values by eight weeks post-dose.
CONCLUSIONS: Canakinumab 150 mg provided significantly greater and more rapid reduction in pain and signs and symptoms of inflammation compared with triamcinolone acetonide 40 mg. Improvements in HRQoL were seen in both treatment groups with a faster onset with canakinumab 150 mg compared with triamcinolone acetonide 40 mg.
TRIAL REGISTRATION: clinicaltrials.gov: NCT00798369
Do actions speak louder than words? Examining children’s ability to follow instructions
The ability to encode, retain, and implement instructions within working memory is central to many behaviours, including classroom activities which underpin learning. The three experiments presented here explored how action—planned, enacted, and observed—impacted 6- to 10-year-old’s ability to follow instructions. Experiment 1 (N = 81) found enacted recall was superior to verbal recall, but self-enactment at encoding had a negative effect on enacted recall and verbal recall. In contrast, observation of other-enactment (demonstration) at encoding facilitated both types of recall (Experiment 2a: N = 81). Further, reducing task demands through a reduced set of possible actions (Experiment 2b; N = 64) led to a positive effect of self-enactment at encoding for later recall (both verbal and enacted). Expecting to enact at recall may lead to the creation of an imaginal spatial-motoric plan at encoding that boosts later recall. However, children’s ability to use the additional spatial-motoric codes generated via self-enactment at encoding depends on the demands the task places on central executive resources. Demonstration at encoding appears to reduce executive demands and enable use of these additional forms of coding
One-Year Outcomes of the Multi-Center StudY to Transplant Hepatitis C-InfeCted kidneys (MYTHIC) Trial
Transplanting kidneys from hepatitis C virus (HCV) viremic donors into HCV-negative patients (HCV D-RNA-positive/R-negative) has evolved from experimental to “standard-of-care” at many centers. Nevertheless, most data derive from single centers and provide only short-term follow-up.
The Multicenter Study to Transplant Hepatitis C-Infected Kidneys (MYTHIC) study was a multicenter (7 sites) trial of HCV D-RNA-positive/R-negative kidney transplantation (KT) followed by 8 weeks of glecaprevir/pibrentasvir (G/P) initiated 2 to 5 days post-KT. Prespecified outcomes included probability of KT (vs. matched waitlist comparators) and 1-year safety outcomes, allograft function, and survival.
Among 63 enrolled patients, 1-year cumulative incidence of KT was approximately 3.5-fold greater for the MYTHIC cohort versus 2055 matched United Network for Organ Sharing (UNOS) comparators who did not opt-in to receive a kidney from an HCV-viremic donor (68% vs. 19%, P < 0.0001). Of 30 HCV D-RNA-positive/R-negative KT recipients, all achieved HCV cure. None developed clinically significant liver disease or HCV-related kidney injury. Furthermore, 1-year survival was 93% and 1-year graft function was excellent (median creatinine 1.17; interquartile range [IQR]: 1.02–1.38 mg/dl). There were 4 cases of cytomegalovirus (CMV) disease among 10 CMV-negative patients transplanted with a kidney from an HCV-viremic/CMV-positive donor.
The 1-year findings from this multicenter trial suggest that opting-in for HCV-viremic KT offers can increase probability of KT with excellent 1-year outcomes. Trial Registration: NCT03781726
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