19672 research outputs found
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Dynamic characterisation of Össur Flex-Run prosthetic feet for a more informed prescription
No full textBackground: The current method of prescribing composite running-specific energy-storing-and-returning feet is subjective and is based only on the amputee’s static body weight/mass. Objectives: The aim was to investigate their dynamic characteristics and create a relationship between these dynamic data and the prescription of foot. Study Design: Experimental Assessment. Methods: This article presents the modal analysis results of the full range of Össur Flex-Run ™ running feet that are commercially available (1LO–9LO) using experimental modal analysis technique under a constant mass at 53 kg and boundary condition. Results: It was shown that both the undamped natural frequency and stiffness increase linearly from the lowest to the highest stiffness category of foot which allows for a more informed prescription of foot when tuning to a matched natural frequency. The low damping characteristics determined experimentally that ranged between 1.5% and 2.0% indicates that the feet require less input energy to maintain the steady-state cyclic motion before take-off from the ground. An analysis of the mode shapes also showed a unique design feature of these feet that is hypothesised to enhance their performance. Conclusion: A better understanding of dynamic characteristics of the feet can help tune the feet to the user’s requirements in promoting a better gait performance. Clinical relevance: The dynamic data determined from this study are needed to better inform the amputees in predicting the natural frequency of the foot prescribed. The amputees can intuitively tune the cyclic body rhythm during walking or running to match with the natural frequency. This could eventually promote a better gait performance. © The International Society for Prosthetics and Orthotics 2018
Important Metabolites in Maintaining Folate Cycle, Homocysteine, and Polyamine Metabolism Associated with Ranibizumab Treatment in Cultured Human Tenon’s Fibroblasts
No full textThe anti-fibrotic properties of ranibizumab have been well documented. As an antagonist to vascular endothelial growth factor (VEGF), ranibizumab works by binding and neutralizing all active VEGF-A, thus limiting progressive cell growth and proliferation. Ranibizumab application in ocular diseases has shown remarkable desired effects; however, to date, its antifibrotic mechanism is not well understood. In this study, we identified metabolic changes in ranibizumab-treated human Tenon’s fibroblasts (HTFs). Cultured HTFs were treated for 48 h with 0.5 mg/mL of ranibizumab and 0.5 mg/mL control IgG antibody which serves as a negative control. Samples from each group were injected into Agilent 6520 Q-TOF liquid chromatography/mass spectrometer (LC/MS) system to establish the metabolite expression in both ranibizumab treated cells and control group. Data obtained was analyzed using Agilent Mass Hunter Qualitative Analysis software to identify the most regulated metabolite following ranibizumab treatment. At p-value < 0.01 with the cut off value of two-fold change, 31 identified metabolites were found to be significantly upregulated in ranibizumab-treated group, with six of the mostly upregulated having insignificant role in fibroblast cell cycle and wound healing regulations. Meanwhile, 121 identified metabolites that were downregulated, and seven of the mostly downregulated are significantly involved in cell cycle and proliferation. Our findings suggest that ranibizumab abrogates the tissue scarring and wound healing process by regulating the expression of metabolites associated with fibrotic activity. In particular, we found that vitamin Bs are important in maintaining normal folate cycle, nucleotide synthesis, and homocysteine and spermidine metabolism. This study provides an insight into ranibizumab’s mechanism of action in HTFs from the perspective of metabolomics. © 2019 by the authors. Licensee MDPI, Basel, Switzerland
Do country stereotypes influence language learning motivation? A study among foreign language learners in Malaysia
No full textIt has been acknowledged in research literature that stereotypes about a target language country held by language learners influence the students’ motivation to learn a foreign language (L2 motivation). However, there is a lack of studies that link explorations of these stereotypes and L2 motivation in a single research project. This mixed-methods study addressed this gap in research literature. It examined relationships between endogenous stereotypes about target language countries and L2 motivation using a sample of 194 students learning foreign languages in a major public university in Malaysia. These languages included French, German, Italian, Portuguese (European and Brazilian varieties), Russian and Spanish. The data were collected through a questionnaire survey. One open-ended question sought the students’ mental images of the target language countries; two thermometer-type scales assessed the students’ general attitudes toward the target language countries and people and 16 closed-ended statements with attached Likert-type scales assessed their L2 motivation. The findings from the qualitative strand of the analysis revealed that the respondents had distinct and predominantly positive images of each of the target language countries. This allowed making a tentative proposition that the country stereotypes would have a positive relationship with the students’ L2 motivation, especially the integrative orientation. Results of the statistical analyses in the quantitative phase indicated that the relationship between the country stereotypes and L2 motivation was the strongest in the case of the integrative orientation. The article concludes with a brief discussion of implications that can be drawn from this study
Factors influencing professional values among Indonesian undergraduate nursing students
No full textBackground: Undergraduate nursing students are required to acquire professional values during professional nurse education to provide safe and high quality patient care. However, there was no documentation in professional values among Indonesian undergraduate nursing students and the factors influencing its development. Purpose: The purpose of this study was to determine professional values among Indonesian undergraduate nursing students and examine the relationship between students’ demographic factors and professional values. Design: A cross-sectional study using convenience sampling was applied to recruit 391 Indonesian undergraduate nursing students. The 26 items of Nurses Professional Values Scale Revision (NPVS-R) with five dimensions was employed to collect data. Descriptive and inferential statistics, independent samples t-test were applied to analyse and interpret data. Results: The result showed that the total score of nurse professional values was high (95.80 ± 12.93). The most important professional value dimension was caring, while activism was the least important values. The NPVS-R total score had a significant association with length of professional clinical practice of the students (p < .05). Conclusion: Nurse educators need to consider the integration of professional values when developing nursing curriculum, in order to ensure that the students develop their own understanding of these values and their importance in practice. © 2019 Elsevier Lt
Uniaxial Cyclic Tensile Stretching at 8% Strain Exclusively Promotes Tenogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stromal Cells
No full textThe present study was conducted to establish the amount of mechanical strain (uniaxial cyclic stretching) required to provide optimal tenogenic differentiation expression in human mesenchymal stromal cells (hMSCs) in vitro, in view of its potential application for tendon maintenance and regeneration. Methods. In the present study, hMSCs were subjected to 1 Hz uniaxial cyclic stretching for 6, 24, 48, and 72 hours; and were compared to unstretched cells. Changes in cell morphology were observed under light and atomic force microscopy. The tenogenic, osteogenic, adipogenic, and chondrogenic differentiation potential of hMSCs were evaluated using biochemical assays, extracellular matrix expressions, and selected mesenchyme gene expression markers; and were compared to primary tenocytes. Results. Cells subjected to loading displayed cytoskeletal coarsening, longer actin stress fiber, and higher cell stiffness as early as 6 hours. At 8% and 12% strains, an increase in collagen I, collagen III, fibronectin, and N-cadherin production was observed. Tenogenic gene expressions were highly expressed (p<0.05) at 8% (highest) and 12%, both comparable to tenocytes. In contrast, the osteoblastic, chondrogenic, and adipogenic marker genes appeared to be downregulated. Conclusion. Our study suggests that mechanical loading at 8% strain and 1 Hz provides exclusive tenogenic differentiation; and produced comparable protein and gene expression to primary tenocytes. © 2019 Hui Yin Nam et al
Shaping properties and outcomes of nickel-titanium rotary and reciprocation systems using micro-computed tomography: A systematic review
No full textObjectives: This systematic review aims to discuss the shaping properties and outcomes of nickel-titanium (NiTi) rotary and reciprocation systems assessed by micro-computed tomography. Data source: A literature search was conducted in PubMed and SCOPUS database until April 2018 to identify investigations examining the shaping properties and outcomes of rotary and reciprocation NiTi systems using micro-computed tomography. In addition, a quality assessment was undertaken for the included studies. Results: A total of 1,110 titles were identified in the literature search. After removal of duplicates, 25 studies satisfied the inclusion criteria. Quality assessment showed that 17 studies were of low risk of bias. Six shaping properties and outcomes including centering ability, transportation, untouched canal walls, canal surface area and volume, microcrack formation, and debris accumulation were discussed. Conclusions: The use of the same system in rotary or reciprocation motions and reciprocating single file systems have comparable transportation and centering ability. No difference was observed between rotary and reciprocation systems/motions in surface area and volume of the canal changes. Untouched canal walls and accumulation of debris remained controversial. No relationship was found between kinematics of instrumentation and the formation of dentinal cracks. © Quintessence
Mechanomyography-based muscle fatigue detection during electrically elicited cycling in patients with spinal cord injury
No full textPatients with spinal cord injury (SCI) benefit from muscle training with functional electrical stimulation (FES). For safety reasons and to optimize training outcome, the fatigue state of the target muscle must be monitored. Detection of muscle fatigue from mel frequency cepstral coefficient (MFCC) feature of mechanomyographic (MMG) signal using support vector machine (SVM) classifier is a promising new approach. Five individuals with SCI performed FES cycling exercises for 30 min. MMG signals were recorded on the quadriceps muscle group (rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM)) and categorized into non-fatigued and fatigued muscle contractions for the first and last 10 min of the cycling session. For each subject, a total of 1800 contraction-related MMG signals were used to train the SVM classifier and another 300 signals were used for testing. The average classification accuracy (4-fold) of non-fatigued and fatigued state was 90.7% using MFCC feature, 74.5% using root mean square (RMS), and 88.8% with combined MFCC and RMS features. Inter-subject prediction accuracy suggested training and testing data to be based on a particular subject or large collection of subjects to improve fatigue prediction capacity. [Figure not available: see fulltext.]. © 2019, International Federation for Medical and Biological Engineering
Radiation dose to Maldivians via the consumption of tuna fish caught from the coastal waters of Indian Ocean
No full textRecognising the consumption of tuna fish as a major foodstuff in Maldivian diet, the presence of naturally occurring radionuclides in Yellowfin and Skipjack tuna are determined by using HPGe gamma-ray spectrometry to evaluate the health hazards to Maldivians. The samples were collected from different atolls of Maldives adjacent to the coastal waters of Indian Ocean. The activity concentrations (Bq kg-1) in Yellowfin tuna for 226Ra, 232Th and 40K are in the ranges of 4.2 ± 1.8-10.5 ± 1.1, 1.3 ± 0.3-3.2 ± 0.7 and 589 ± 29-697 ± 34, respectively while in Skipjack tuna the respective ranges are 3.9 ± 0.5-13.2 ± 1.1, 1.3 ± 0.3-2.7 ± 0.6 and 511 ± 28-681 ± 35. The committed effective dose (mean 263 μSv y-1) received by an individual due to the dietary intake of Yellowfin tuna falling below the UNSCEAR referenced global internal dose limit of 290 μSv y-1; while for Skipjack tuna, the estimated dose (mean 365 μSv y-1) exceeds the world average limiting value. The carcinogenic risk was found to be well below the ICRP referenced acceptable limit of 2.5 × 10-3. The present study indicates that the radiation dose to Maldivian via the consumption of Yellowfin tuna poses an insignificant threat to the public health. However, prolonged consumption of Skipjack tuna fish from the studied areas may pose a cumulative risk to the public health. © 2019 The Author(s)
“The Constructiveness and Dialogic Energy of the ‘Postcolonial Imagination’”: In Conversation with Bill Ashcroft
No full text[No abstract available
Evaluation of pathogenicity level of three different strains of fusarium oxysporum in Musa acuminata cv. Berangan
No full textFusarium oxysporum is one of the most adaptive and pathogenic fungus that causes wilting in banana. It is regarded as one of the economically destructive fungus and control of this disease is always ineffective once the disease becomes established in banana plantations. Various researches have been carried out, but sustainable solution is yet to achieve. In this study, we identified the infection phenotypically through LSI and RDI which can be only done after 5 th -week of post inoculation. With qPCR application, we identified the infection level much faster within 2 to 96 hrs. Disease severity index obtained from LSI and RDI value showed that Berangan is highly susceptible towards C1 HIR, 9888 and 2296. Meanwhile, qPCR analysis besides showing infection pattern as early as 2 hrs in Berangan was infected with C1 HIR, 9888 and 2296. We also found that additional information such as specific genes were expressed in the Berangan infected with C1 HIR, 9888 or 2296. This information can be used to identify the fusarium strain that is actually infecting Berangan. This could help planters to identify early infection of fusarium as well as strain recognition. © 2019, World Research Association. All rights reserved