192 research outputs found
Response Surface Modelling of Methylene Blue Adsorption onto Seaweed, Coconut Shell and Oak Wood Hydrochars
Adsorption of methylene blue (MB) dye from an aqueous solution onto hydrochars produced from brown seaweed (Fucus Serratus) (FS-HC), coconut shell (CS-HC), and oak wood (Oak-HC) at different temperatures (200β250 Β°C) was investigated in a batch system. Response surface modelling (RSM) was used to investigate the effect of initial MB concentration (50β300 mg/L), contact time (0β240 min), and solution pH (2β12) on the adsorption process. RSM was also used to model and optimise these parameters for efficient adsorption. Kinetic and isotherms studies were carried out to study the adsorption mechanism onto the hydrochars. It was found that the best adsorbent from the RSM model was FS-HC200, and the optimal conditions for greater MB dye uptake were lower initial MB concentration (50 mg/L), pH 6 and contact time of 84 min; removing >99% of MB. Langmuir and RedlichβPeterson isotherm models fitted the adsorption of MB onto hydrochars prepared at 200 and 250 Β°C. Freundlich and RedlichβPeterson isotherms were suitable for hydrochars produced at 220 Β°C. FS-HCs have the highest maximum adsorption capacity of MB of about (8.60β28.57) mg/g calculated from the Langmuir isotherm. The adsorption process for all the hydrochars followed a pseudo-second-order model (RΒ² = 0.96β1.00), and film diffusion and intraparticle diffusion were the rate-determining steps. Therefore, this work identifies cheap adsorbents from biowaste that are effective for the removal of cationic pollutants from wastewater
Trials and tribulations: understanding motivations for clinical research participation amongst adults with cystic fibrosis
In the context of understanding motivations for clinical research participation, many authors consider issues such as informed consent and how patients perceive the research method and process. However, many investigations focus only on one method of research, most commonly the randomised controlled trial. Understanding how chronically ill members of one specific patient group respond to all requests for research participation are rare. Cystic fibrosis (CF), a genetic condition whereby those affected are used to taking a wide array of treatments and attending a specialist care centre over many years, and are generally knowledgeable about their condition, represents an ideal case for investigating how staff requests for clinical research participation are accepted or declined. Using Bloor's systems of relevance framework for risk behaviour and risk reduction, specialist CF centre patients' motivations for participation or non-participation in clinical research can be understood. The framework takes into account two sets of conceptual oppositions: habituation and calculation, constraint and volition. These oppositions represent a range along a continuum of risk behaviour rather than being absolute distinctions. Decisions to participate are influenced mainly by the patient's state of health at the time of request, the nature of the trial and the social context within which sufferers are placed. Understanding why chronically ill patients refuse some requests and yet accept others may assist researchers in designing protocols that take these factors into account and achieve the desired numbers of participants whilst protecting those in vulnerable positions. Β© 2005 Elsevier Ltd. All rights reserved
Mediators of the relationship between thin-ideal internalization and body dissatisfaction in the natural environment
Social comparisons (i.e., body, eating, exercise) and body surveillance were tested as mediators of the thin-ideal internalization-body dissatisfaction relationship using ecological momentary assessment (EMA). Participants were 232 college women who completed a 2-week EMA protocol, responding to questions three times per day. Multilevel path analysis was used to examine a 2-1-1 mediation model (thin-ideal internalization assessed as trait; between-person effects examined) and a 1-1-1 model (component of thin-ideal internalization [thin-ideal importance] assessed momentarily; within- and between-person effects examined). For the 2-1-1 model, only body comparison and body surveillance were significant specific mediators of the between-person effect. For the 1-1-1 model, all four variables were significant specific mediators of the within-person effect. Only body comparison was a significant specific mediator of the between-person effect. At the state level, many processes explain the thin-ideal internalization-body dissatisfaction relationship. However, at the trait level, body comparison and body surveillance are more important explanatory factors
Examining an elaborated sociocultural model of disordered eating among college women: The roles of social comparison and body surveillance
Social comparison (i.e., body, eating, exercise) and body surveillance were tested as mediators of the thin-ideal internalization-body dissatisfaction relationship in the context of an elaborated sociocultural model of disordered eating. Participants were 219 college women who completed two questionnaire sessions 3 months apart. The cross-sectional elaborated sociocultural model (i.e., including social comparison and body surveillance as mediators of the thin-ideal internalization-body dissatisfaction relation) provided a good fit to the data, and the total indirect effect from thin-ideal internalization to body dissatisfaction through the mediators was significant. Social comparison emerged as a significant specific mediator while body surveillance did not. The mediation model did not hold prospectively; however, social comparison accounted for unique variance in body dissatisfaction and disordered eating 3 months later. Results suggest that thin-ideal internalization may not be βautomaticallyβ associated with body dissatisfaction and that it may be especially important to target comparison in prevention and intervention efforts
Antibody Responses to <i>Schistosoma mansoni</i> Schistosomula Antigens
While antigens from Schistosoma schistosomula have been suggested as potential vaccine candidates, the association between antibody responses with schistosomula antigens and infection intensity at reinfection is not well known. Schistosoma mansoni-infected individuals were recruited from a schistosomiasis endemic area in Uganda (nΒ =Β 372), treated with 40Β mg/kg praziquantel (PZQ) and followed up at five weeks and at one year post-treatment. Pre-treatment and five weeks post-treatment immunoglobulin (Ig) E, IgG1 and IgG4 levels against recombinant schistosomula antigens rSmKK7, rSmLy6A, rSmLy6B and rSmTSP7 were measured using ELISA. Factors associated with detectable pre-treatment or post-treatment antibody response against the schistosomula antigens and the association between five-week antibody responses and one year post-treatment reinfection intensity among antibody responders were examined. Being male was associated with higher pre-treatment IgG1 to rSmKK7, rSmLy6a and AWA. Five weeks post-treatment antibody responses against schistosomula antigens were not associated with one year post-treatment reinfection intensity among antibody responders' antibody levels against rSmKK7, rSmLy6B and rSmTSP7 dropped, but increased against rSmLy6A, AWA and SEA at five weeks post-treatment among antibody responders. S.Β mansoni-infected individuals exhibit detectable antibody responses to schistosomula antigens that are affected by treatment. These findings indicate that schistosomula antigens induce highly varied antibody responses and could have implications for vaccine development
Hard exercise, affect lability, and personality among individuals with bulimia nervosa
The current study explores the personality traits of compulsivity (e.g., sense of orderliness and duty to perform tasks completely) and restricted expression (e.g., emotion expression difficulties) as potential moderators of the relation between affect lability and frequency of hard exercise episodes in a sample of individuals with bulimic pathology. Participants were 204 adult females recruited in five Midwestern cities who met criteria for threshold or subthreshold bulimia nervosa (BN). Compulsivity was found to significantly moderate the relation between affect lability and number of hard exercise episodes over the past 28 days, such that among those with high compulsivity, level of affect lability was associated with the number of hard exercise episodes; whereas, among those with low compulsivity, affect lability was not associated with the number of hard exercise episodes. The same pattern of findings emerged for restricted expression; however, this finding approached, but did not reach statistical significance. As such, it appears that affect lability is differentially related to hard exercise among individuals with BN depending upon the level of compulsivity and, to a more limited extent, restricted expression. These results suggest that, for individuals with BN with either compulsivity or restricted expression, focusing treatment on increasing flexibility and/or verbal expression of emotions may help them in the context of intense, fluctuating affect
Subjective and objective binge eating in relation to eating disorder symptomatology, negative affect, and personality dimensions
The current study explored the clinical meaningfulness of distinguishing subjective (SBE) from objective binge eating (OBE) among individuals with threshold/subthreshold bulimia nervosa (BN). We examined relations between OBEs and SBEs and eating disorder symptoms, negative affect, and personality dimensions using both a group comparison and a continuous approach
Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer
BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kgβ1over 1 h, followed by a maintenance infusion of 4 mg kgβ1hβ1for 5 h. MMC 6 mg mβ2was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1β4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities β nausea/vomiting and vein pain β were mild and did not exceed CTC grade 2. Liver31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity. Β© 2000 Cancer Research Campaig
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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