250 research outputs found
Effects of Acute Eccentric Exercise on Appetite-Related Hormones and Food Preferences in Men
Eccentric exercise has been suggested to improve muscle atrophy, muscle function, and insulin sensitivity. The aim of this study was to examine the effect of acute eccentric exercise on appetite-related hormones, food preferences, and food intake. Fourteen moderately active men were recruited to participate in this study (age 24.2 ± 5.5 years; BMI 23.4 ± 3.3 kg/m2; VO2max 48.9 ± 3.1 ml/kg/min). Three different conditions were implemented; no exercise, flat running “inclination 0” and downhill running “inclination –12%.” Appetite-related hormones, subjective appetite sensations, food preference and reward, and ad libitum food intake were measured at pre-, immediately post-, and 24 h post exercise.There were no significant median changes in total ghrelin or pancreatic peptide concentrations between conditions. There were also no median differences in subjective appetite ratings or energy intake between conditions, but the median change in explicit liking of sweet versus savory foods differed significantly between pre-exercise and 24 h post exercise (p = .013). Post-hoc analysis observed a significant difference in the pre-exercise to 24 h post exercise change between front running and downhill running (p = .023), and indicated greater liking of savory foods over sweet foods in downhill running than front running. However, no further differences were seen between conditions for the remaining food preference parameters, suggesting there were no systematic trends in these data. In conclusion, there was no effect of front and downhill running on eating behavior as compared to a nonexercise control condition, but these data need to be replicated in a larger and more heterogeneous sample
The pH and Concentration of Hydrogen Peroxide – Impact upon Dental Enamel Properties and Response to Dietary Staining, Erosion, and Remineralisation
Ph. D. Thesis.Hydrogen peroxide (HP) based whitening products can damage enamel due to their pH and
concentration. This in-vitro study investigates the effect of HP pH and concentration on selected
enamel properties. In addition, combined effects of whitening/remineralisation and subsequent
resistance to simulated dietary erosion and staining were investigated.
Polished bovine enamel samples were treated with 6, 20, 40wt.% HP at pH 5, 7 and 9, for 2
hours daily for ten days. Samples were stored in artificial saliva at 37C before and after
treatment. Whitening/remineralisation investigations were performed using 6wt.% HP in
combination with either casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) or
nanohydroxyapatite (nHA). Samples were then subjected to simulated dietary staining using
coffee and erosion using 0.3% citric acid (pH3.8). Measurements of enamel roughness (Ra),
hardness (HV), and colour change (E) were made before and after treatment using atomic
force microscopy, micro-hardness testing, and spectrophotometry. Mineral loss and qualitative
surface evaluations were undertaken using energy dispersive x-ray spectroscopy (EDX) and
scanning electron microscopy (SEM), respectively, after treatment.
As HP concentration increased and pH decreased there was a statistically significant increase
in E (P<0.05). Greatest increase in Ra and decrease in HV occurred in enamel treated with
pH9 40% HP. Remineralisation did not significantly affect E, Ra, and HV of whitened enamel.
CPP-ACP was effective in preventing statistically significant changes in Ra and HV values
after erosive cycling. Enamel treated with nHA exhibited the greatest dietary stain uptake. No
significant changes in enamel Ca, C, and P occurred after whitening, remineralisation, and
erosion. SEM images revealed distinct surface changes mostly in pH9 and nHA treated samples.
All whitened specimens exhibited significantly greater colour change than the control group.
Neutral HP caused the least damage to whitened enamel while producing a satisfactory
whitening effect. Remineralising agents did not reduce whitening side effects, however, CPPACP prevented significant Ra and HV changes after dietary erosion.College of Dentistry-Princess
Nourah bint Abdulrahman Universit
Ultrasound-based techniques as alternative treatments for chronic wounds: A comprehensive review of clinical applications
Ultrasound (US) waves have been recently developed for the treatment of different chronic wounds with promising therapeutic outcomes. However, the clinical efficacy of these techniques is still not fully understood and standard guidelines on dose ranges and possible side effects should be determined. This paper aims to comprehensively review the recent advances in US techniques for chronic wound treatment, their therapeutic efficacies, and clinical considerations and challenges. The databases of PubMed (1985-2017), EMBASE (1985-2017), Web of Sciences (1985-2017), Cochrane central library (1990-2017), and Google Scholar (1980-2017) were searched using the set terms. The obtained results were screened for the title and abstract by two authors and the relevant papers were reviewed for further details. Preclinical and clinical studies have shown strong evidence on the therapeutic efficiency of US in chronic wounds. The main limitation on developing clinical standard protocols of US for treatment of wounds is the lack of definite dose-response for each wound. However, spatial average temporal average is the main parameter for defining US dosage in wound treatment. The range of 0.5 to 3 W/cm2 is a range of dose exerting significant therapeutic outcomes and minimum adverse effects. Low-frequency US waves can accelerate the healing speed of open wounds as well as deep-tissue injuries. In addition, US waves show promising therapeutic efficacy for chronic wounds. To develop clinical US protocol for each wound type, further in vitro and in vivo preclinical and clinical trials are needed to reach an exact dose-response for each wound type
ADSORPTION OF FOOD COLORING ALLURA RED DYE (E129) FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON
The adsorption behavior of Allura red (E129) from aqueous solutions onto activated carbon was successfully investigated. All factors affecting the adsorption process were carefully studied and the conditions were optimized. Adsorption of E129 onto activated carbon was found to increase by decreasing the mass of activated carbon, pH and ionic strength of the solution and by increasing temperature. The adsorption capacity of the activated carbon for Allura red was relatively high. Under the optimum conditions, the maximum adsorption capacity for E129 dye was 72.85 mg/g. Three adsorption models; Langmuir, Freundlich and Temkin model were investigated regarding the adsorption of E129. The models’ parameters KL, qm, R2, (n) were determined and found to be 0.0222, 72.85 mg/g, 0.9057-0.9984, and 0.992, respectively. Also, pseudo first and second-order kinetic models were tested to determine the best-fit model to the adsorption of E129 dye onto activated carbon. The results showed that the adsorption of E129 onto activated carbon obeyed both the Freundlich isotherm and pseudo second-order kinetic models. Moreover, thermodynamic studies indicated that the adsorption of E129 dye onto the activated carbon was spontaneous.Â
3D printed electro-responsive system with programmable drug release
Precision medicine is the next frontier in pharmaceutical research, aiming to improve the safety and efficacy of therapeutics for patients. The ideal drug delivery system (DDS) should be programmable to provide real-time controlled delivery that is personalised to the patient's needs. However, little progress has been made in this domain. Herein, we combined two cutting-edge technologies, conductive polymers (CPs) and three-dimensional (3D) printing, to demonstrate their potential for achieving programmable controlled release. A DDS was formulated where the CP provided temporal control over drug release. 3D printing was used to ensure dimensional control over the design of the DDS. The CP used in this study is known to be fragile, and thus was blended with thermoplastic polyurethane (TPU) to achieve a conductive elastomer with sound mechanical properties. Rheological and mechanical analyses were performed, where it was revealed that formulation inks with a storage modulus in the order of 103–104 Pa were both extrudable and maintained their structural integrity. Physico-chemical analysis confirmed the presence of the CP functional groups in the 3D printed DDS. Cyclic voltammetry demonstrated that the DDS remained conductive for 100 stimulations. in vitro drug release was performed for 180 min at varying voltages, where a significant difference (p < 0.05) in cumulative release was observed between either ±1.0 V and passive release. Furthermore, the responsiveness of the DDS to pulsatile stimuli was tested, where it was found to rapidly respond to the voltage stimuli, consequently altering the release mechanism. The study is the first to 3D print electroactive medicines using CPs and paves the way for digitalising DDS that can be integrated into the Internet of Things (IoT) framework
Intelligent Optimization Systems for MaintenanceScheduling of Power Plant Generators
This paper presents a Genetic Algorithm (GA) and Ant-Colony (AC) optimization model for power plant generators’ maintenance scheduling. Maintenance scheduling of power plant generators is essential for ensuring the reliability and economic operation of a power system. Proper maintenance scheduling prolongs the shelf life of the generators and prevents unexpected failures. To reduce the cost and duration of generator maintenance, these models are built with various constants, fitness functions, and objective functions. The Analytical Hierarchy Process (AHP), a decision-making tool, is implemented to aid the researcher in prioritizing and re-ranking the maintenance activities from the most important to the least. The intelligent optimization models are developed using MATLAB and the developed intelligent algorithms are tested on a case study in a coal power plant located at minjung, Perak, Malaysia. The power plant is owned and operated by Tenaga Nasional Berhad (TNB), the electric utility company in peninsular Malaysia. The results show that GA outperforms ACO since it reduces maintenance costs by 39.78% and maintenance duration by 60%. The study demonstrates that the proposed optimization method is effective in reducing maintenance time and cost while also optimizing power plant operation
Electroactive Polymers for On-Demand Drug Release
Conductive materials have played a significant role in advancing society into the digital era. Such materials are able to harness the power of electricity and are used to control many aspects of daily life. Conductive polymers (CPs) are an emerging group of polymers that possess metal-like conductivity yet retain desirable polymeric features, such as processability, mechanical properties, and biodegradability. Upon receiving an electrical stimulus, CPs can be tailored to achieve a number of responses, such as harvesting energy and stimulating tissue growth. The recent FDA approval of a CP-based material for a medical device has invigorated their research in healthcare. In drug delivery, CPs can act as electrical switches, drug release is achieved at a flick of a switch, thereby providing unprecedented control over drug release. In this review, recent developments in CP as electroactive polymers for voltage-stimuli responsive drug delivery systems are evaluated. The review demonstrates the distinct drug release profiles achieved by electroactive formulations, and both the precision and ease of stimuli response. This level of dynamism promises to yield “smart medicines” and warrants further research. The review concludes by providing an outlook on electroactive formulations in drug delivery and highlighting their integral roles in healthcare IoT
Multi Criteria Optimization Approach for Dressing of Vitrified Grinding Wheel
Rotary diamond dressers are widely used for the dressing to improve the efficiency of vitrified grinding wheel. The paper focuses on the process parameters, i.e., feed speed of dresser, depth of cut, grinding wheel velocity, velocity ratio between grinding wheel and rotary dresser, number of pass and dressing method (up-cut or down-cut) in rotary diamond dressing. The objective is to investigate the effect of these process parameters with their interactions for two response parameters, dressing ratio and overlapped dressed area. As far as the response parameters are concerned, the goal is to maximize dressing ratio and minimize overlapped dressed area simultaneously. Thirty-six experiments were designed and performed. Analysis of variance and multi-criteria optimization approach are opted to find out significant process parameters and optimal parameter setting. Finally, the significant process parameters, dressing method and number of pass are identified as well and the optimal parameter setting is also determined
A non-nutritive feeding intervention alters the expression of efflux transporters in the gastrointestinal tract
Intestinal interactions with nutrients, xenobiotics and endogenous hormones can influence the expression of clinically relevant membrane transporters. These changes in the gastrointestinal (GI) physiology can in turn affect the absorption of numerous drug substrates. Several studies have examined the effect of food on intestinal transporters in male and female humans and animal models. However, to our knowledge no studies have investigated the influence of a non-nutritive fibre meal on intestinal efflux transporters and key sex and GI hormones. Here, we show that a fibre meal increased the acute expression of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug-resistance-associated protein-2 (MRP2) in small intestinal segments in both male and female Wistar rats. Enzyme-linked immunosorbent assays were used for the protein quantification of efflux transporters and hormonal plasma concentration. In male rats, the fibre meal caused the plasma concentration of the GI hormone cholecystokinin (CCK) to increase by 75% and the sex hormone testosterone to decrease by 50%, whereas, in contrast, the housing food meal caused a decrease in CCK by 32% and testosterone saw an increase of 31%. No significant changes in the hormonal concentrations, however, were seen in female rats. A deeper understanding of the modulation of efflux transporters by sex, food intake and time can improve our understanding of inter- and intra-variability in the pharmacokinetics of drug substrates
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