623 research outputs found

    Effects of blanching, drying and extraction processes on the antioxidant activity of yam (Dioscorea alata)

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    [[abstract]]The effects of blanching, drying and extraction processes on the antioxidant activities of one kind of Taiwanese yam peel, Darsan (Dioscorea alata), were investigated. The antioxidant measurements included total phenolic content, reducing power and α ,α-diphenyl-ÎČ-pricryl-hydrazyl (DPPH) radical-scavenging activity. The 50% ethanolic, hot water and water extracts from the peel all had much higher antioxidant activities than those extracts from the flesh. Among three extraction methods, 50% ethanolic extraction resulted in the highest antioxidant activities in the peel, while hot water extraction was more appropriate for the flesh. Blanching by immersing the peel in 85 °C water for 30 s caused significant reductions in the antioxidant activities of all the extracts from the peel. Generally speaking, freeze-dried peel maintained higher antioxidant activities than hot air-dried peel

    Multizone decomposition for simulation of time-dependent problems using the multiquadric scheme

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    AbstractThis paper discusses the application of the multizone decomposition technique with multiquadric scheme for the numerical solutions of a time-dependent problem. The construction of the multizone algorithm is based on a domain decomposition technique to subdivide the global region into a number of finite subdomains. The reduction of ill-conditioning and the improvement of the computational efficiency can be achieved with a smaller resulting matrix on each subdomain. The proposed scheme is applied to a hypothetical linear two-dimensional hydrodynamic model as well as a real-life nonlinear two-dimensional hydrodynamic model in the Tolo Harbour of Hong Kong to simulate the water flow circulation patterns. To illustrate the computational efficiency and accuracy of the technique, the numerical results are compared with those solutions obtained from the same problem using a single domain multiquadric scheme. The computational efficiency of the multizone technique is improved substantially with faster convergence without significant degradation in accuracy

    A personal knowledge management tool that supports organizational knowledge management

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    This paper describes the concept and design of PK-MAST (a Personal Knowledge Management And Sharing Tool), which is a novel knowledge management tool and framework that seeks to bridge the gap between personal knowledge management and organizational knowledge sharing. PK-MAST gives the user a strong ‘personal’ feel in capturing knowledge for his/her own purposes and is very easy to use, but it also supports selective knowledge sharing with minimal effort from the user

    A loop-mediated isothermal amplification (LAMP) assay for rapid detection of Anaplasma phagocytophilum infection in dogs

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    A simple and rapid diagnostic method of Anaplasma phagocytophilum infection was established, employing the loop-mediated isothermal amplification (LAMP) reaction. With 1 set of 4 specific primers targeting the citrate synthase (gltA) gene of A. phagocytophilum, the LAMP assay rapidly amplified the target DNA sequence in a single tube in 1 h, requiring only a water bath for reaction. When visualized by gel electrophoresis, the LAMP products appeared as a ladder-like pattern, with many bands of different sizes from 180 base pairs up to the loading well. The results obtained from testing 32 clinical blood samples of dogs demonstrated that the LAMP method was more sensitive than nested PCR in the diagnosis reaction for the detection of A. phagocytophilum DNA

    Knowledge-based process management – an approach to handling adaptive workflow

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    In recent years, many organisations have found enterprise modelling, especially business process modelling, to be an effective tool for managing organisational change. The application of business processing modelling has brought benefits to many organisations, but the models developed tend to be used for reference during business operations and re-engineering activities; they rarely play an active role in supporting the day-to-day execution of the processes. While workflow management systems are widely used for the streamlined management of "administrative" business processes, current systems are unable to cope with the more dynamic situations encountered in ad-hoc and collaborative processes [1]. A system that supports complex and dynamically changing processes is required. There is increasing interest in making workflow systems more adaptive [8][20] and using knowledge-based techniques to provide more flexible process management support than is possible Published in Knowledge-based Systems, Vol 16, 2003, pp149-160 Page 2 using current workflow systems [4][21]. This paper describes the results of a collaborative project between Loughborough University and the University of Edinburgh. ICI and Unilever were industrial partners on the project, providing real business requirements in the application domain. The project investigated the use of ontologies, agents and knowledge based planning techniques to provide support for adaptive workflow or flexible workflow management, especially in the area of new product development within the chemical industries

    Evaluating the health-related quality of life of the rare disease population in Hong Kong using EQ-5D 3-level

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    Objectives This study aimed to establish a normative profile of health-related quality of life (HRQOL) of the rare disease (RD) population in Hong Kong (HK) and identify potential predictors. Methods Between March 2020 and October 2020, patients with RD and caregivers were recruited through Rare Disease Hong Kong, the largest RD patient group alliance in HK. HRQOL was derived using the EQ-5D 3-Level with reference to the established HK value set. Utility scores were stratified according to demographics and disease-related information. Multiple linear regression was performed to explore the associations between patient characteristics and HRQOL. Results A total of 286 patients, covering 107 unique RDs, reported a mean utility score of 0.53 (SD 0.36). Thirty patients (10.5%) reported negative utility scores, indicating worse-than-death health states. More problems were recorded in the “usual activities” and “self-care” dimensions. Univariate analyses revealed that neurologic diseases, high out-of-pocket expenditure, home modification, and living in public housing or subdivided flats/units were significantly associated with lower HRQOL. A total of 99 caregivers reported a mean utility score of 0.78 (SD 0.17), which was significantly associated with the utility score of patients they took care of (r = 0.32; P = .001). Conclusions The normative profile of the RD population was established, which revealed lower HRQOL in the RD population than other chronic disease groups and general population in HK. Findings were corroborated by evidence from other cohorts using EQ-5D, combined as part of a meta-analysis. Identifying predictors highlight areas that should be prioritized to improve HRQOL of RD population through clinical and psychosocial dimensions

    Litter inputs, but not litter diversity, maintain soil processes in degraded tropical forests — a cross-continental comparison

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    Land-use change in tropical forests can reduce biodiversity and ecosystem carbon (C) storage, but although changes in aboveground biomass C in human-modified tropical forests are well-documented, patterns in the dynamics and storage of C belowground are less well characterised. To address this, we used a reciprocal litter transplant experiment to assess litter decomposition and soil respiration under distinct litter types in forested or converted habitats in Panama, Central America, and in Sabah, Malaysian Borneo. The converted habitats comprised a large clearing on the Panama Canal and oil palm plantation in Borneo; forested habitats comprised a 60-year old secondary forest in Panama and a disturbed forest in Borneo that was selectively logged until 2008. In each habitat, we installed mesocosms and litterbags with litter collected from old-growth forest, secondary forest or an introduced species: Elaeis guineensis in Borneo and Saccharum spontaneum in Panama. We measured litter mass loss, soil respiration, and soil microbial biomass during nine months at each site. Decomposition differed markedly between habitat types and between forest vs. introduced litter, but the decay rates and properties of old-growth and secondary forest litters in the forest habitats were remarkably similar, even across continents. Slower decomposition of all litter types in the converted habitats was largely explained by microclimate, but the faster decay of introduced litter was linked to lower lignin content compared to the forest litter. Despite marked differences in litter properties and decomposition, there was no effect of litter type on soil respiration or microbial biomass. However, regardless of location, litter type, and differences in soil characteristics, we measured a similar decline in microbial activity and biomass in the absence of litter inputs. Interestingly, whereas microbial biomass and soil respiration increased substantially in response to litter inputs in the forested habitats and the converted habitat in Panama, there was little or no corresponding increase in the converted habitat in Borneo, indicating that soil recovery capacity had declined substantially in oil palm plantations. Overall, our results suggest that litter inputs are essential to preserve key soil processes, but litter diversity may be less important, especially in highly disturbed habitats

    Active ingredients in Chinese medicines promoting blood circulation as Na+/K+-ATPase inhibitors

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    The positive inotropic effect of cardiac glycosides lies in their reversible inhibition on the membrane-bound Na+/K+-ATPase in human myocardium. Steroid-like compounds containing a core structure similar to cardiac glycosides are found in many Chinese medicines conventionally used for promoting blood circulation. Some of them are demonstrated to be Na+/K+-ATPase inhibitors and thus putatively responsible for their therapeutic effects via the same molecular mechanism as cardiac glycosides. On the other hand, magnesium lithospermate B of danshen is also proposed to exert its cardiac therapeutic effect by effectively inhibiting Na+/K+-ATPase. Theoretical modeling suggests that the number of hydrogen bonds and the strength of hydrophobic interaction between the effective ingredients of various medicines and residues around the binding pocket of Na+/K+-ATPase are crucial for the inhibitory potency of these active ingredients. Ginsenosides, the active ingredients in ginseng and sanqi, substantially inhibit Na+/K+-ATPase when sugar moieties are attached only to the C-3 position of their steroid-like structure, equivalent to the sugar position in cardiac glycosides. Their inhibitory potency is abolished, however, when sugar moieties are linked to C-6 or C-20 position of the steroid nucleus; presumably, these sugar attachments lead to steric hindrance for the entrance of ginsenosides into the binding pocket of Na+/K+-ATPase. Neuroprotective effects of cardiac glycosides, several steroid-like compounds, and magnesium lithospermate B against ischemic stroke have been accordingly observed in a cortical brain slice-based assay model, and cumulative data support that effective inhibitors of Na+/K+-ATPase in the brain could be potential drugs for the treatment of ischemic stroke

    Green and efficient production of octyl hydroxyphenylpropionate using an ultrasound-assisted packed-bed bioreactor

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    A solvent-free system to produce octyl hydroxyphenylpropionate (OHPP) from p-hydroxyphenylpropionic acid (HPPA) and octanol using immobilized lipase (Novozym(A (R)) 435) as a catalyst in an ultrasound-assisted packed-bed bioreactor was investigated. Response-surface methodology (RSM) and a three-level-three-factor Box-Behnken design were employed to evaluate the effects of reaction temperature (x (1)), flow rate (x (2)) and ultrasonic power (x (3)) on the percentage of molar production of OHPP. The results indicate that the reaction temperature and flow rate were the most important variables in optimizing the production of OHPP. Based on a ridge max analysis, the optimum conditions for OHPP synthesis were predicted to consist of a reaction temperature of 65A degrees C, a flow rate of 0.05 ml/min and an ultrasonic power of 1.74 W/cm(2) with a yield of 99.25%. A reaction was performed under these optimal conditions, and a yield of 99.33 +/- A 0.1% was obtained
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