A review of the six-minute walk test: Its implication as a self-administered assessment tool

Promoting self-management and monitoring physical activity are important strategies in chronic heart disease (CHD) management. The six-minute walk test (6MWT) is a commonly used sub-maximal exercise test for measuring physical functional capacity. The aim of this paper is to review the current literature on 6MWT relating to methodological issues as well as exploring the potential of the protocol to be adopted as a self-administered exercise test. The Medline, CINAHL, Science Direct and the World Wide Web using the search engine Google, were searched for articles describing the administration, reliability and validity of the 6MWT. Findings of the integrative literature review the 6MWT is a simple, safe tool. To date, the capacity for self-administration of the 6MWT has not been investigated. Adapting the 6MWT as a patient-reported outcome measure may enhance the capacity, not only for clinicians to monitor functional status, but also promote self-management by enabling individuals to monitor changes in their functional capacity

Effective inhibition of foot-and-mouth disease virus (FMDV) replication in vitro by vector-delivered microRNAs targeting the 3D gene

<p>Abstract</p> <p>Background</p> <p>Foot-and-mouth disease virus (FMDV) causes an economically important and highly contagious disease of cloven-hoofed animals. RNAi triggered by small RNA molecules, including siRNAs and miRNAs, offers a new approach for controlling viral infections. There is no report available for FMDV inhibition by vector-delivered miRNA, although miRNA is believed to have more potential than siRNA. In this study, the inhibitory effects of vector-delivered miRNAs targeting the 3D gene on FMDV replication were examined.</p> <p>Results</p> <p>Four pairs of oligonucleotides encoding 3D-specific miRNA of FMDV were designed and selected for construction of miRNA expression plasmids. In the reporter assays, two of four miRNA expression plasmids were able to significantly silence the expression of 3D-GFP fusion proteins from the reporter plasmid, p3D-GFP, which was cotransfected with each miRNA expression plasmid. After detecting the silencing effects of the reporter genes, the inhibitory effects of FMDV replication were determined in the miRNA expression plasmid-transfected and FMDV-infected cells. Virus titration and real-time RT-PCR assays showed that the p3D715-miR and p3D983-miR plasmids were able to potently inhibit the replication of FMDV when BHK-21 cells were infected with FMDV.</p> <p>Conclusion</p> <p>Our results indicated that vector-delivered miRNAs targeting the 3D gene efficiently inhibits FMDV replication <it>in vitro</it>. This finding provides evidence that miRNAs could be used as a potential tool against FMDV infection.</p

Lentviral-mediated RNAi to inhibit target gene expression of the porcine integrin αv subunit, the FMDV receptor, and against FMDV infection in PK-15 cells

<p>Abstract</p> <p>Background</p> <p>shRNA targeting the integrin αv subunit, which is the foot-and-mouth disease virus (FMDV) receptor, plays a key role in virus attachment to susceptible cells. We constructed a RNAi lentiviral vector, iαv pLenti6/BLOCK -iT™, which expressed siRNA targeting the FMDV receptor, the porcine integrin αv subunit, on PK-15 cells. We also produced a lentiviral stock, established an iαv-PK-15 cell line, evaluated the gene silencing efficiency of mRNA using real-time qRT-PCR, integrand αv expression by indirect immunofluorescence assay (IIF) and cell enzyme linked immunosorbent assays (cell ELISA), and investigated the in vivo inhibitory effect of shRNA on FMDV replication in PK-15 cells.</p> <p>Results</p> <p>Our results indicated successful establishment of the iαv U6 RNAi entry vector and the iαv pLenti6/BLOCK -iT expression vector. The functional titer of obtained virus was 1.0 × 10⁶TU/mL. To compare with the control and mock group, the iαv-PK-15 group αv mRNA expression rate in group was reduced by 89.5%, whilst IIF and cell ELISA clearly indicated suppression in the experimental group. Thus, iαv-PK-15 cells could reduce virus growth by more than three-fold and there was a > 99% reduction in virus titer when cells were challenged with 10²TCID₅₀of FMDV.</p> <p>Conclusions</p> <p>Iαv-PK-15 cells were demonstrated as a cell model for anti-FMDV potency testing, and this study suggests that shRNA could be a viable therapeutic approach for controlling the severity of FMD infection and spread.</p

Global-regional nested simulation of particle number concentration by combing microphysical processes with an evolving organic aerosol module

Aerosol microphysical processes are essential for the next generation of global and regional climate and air quality models to determine particle size distribution. The contribution of organic aerosols (OAs) to particle formation, mass, and number concentration is one of the major uncertainties in current models. A new global–regional nested aerosol model was developed to simulate detailed microphysical processes. The model combines an advanced particle microphysics (APM) module and a volatility basis set (VBS) OA module to calculate the kinetic condensation of low-volatility organic compounds and equilibrium partitioning of semi-volatile organic compounds in a 3-D framework using global–regional nested domain. In addition to the condensation of sulfuric acid, the equilibrium partitioning of nitrate and ammonium, and the coagulation process of particles, the microphysical processes of the OAs are realistically represented in our new model. The model uses high-resolution size bins to calculate the size distribution of new particles formed through nucleation and subsequent growth. The multi-scale nesting enables the model to perform high-resolution simulations of the particle formation processes in the urban atmosphere in the background of regional and global environments. By using the nested domains, the model reasonably reproduced the OA components obtained from the analysis of aerosol mass spectrometry measurements through positive matrix factorization and the particle number size distribution in the megacity of Beijing during a period of approximately a month. Anthropogenic organic species accounted for 67 % of the OAs of secondary particles formed by nucleation and subsequent growth, which is considerably larger than that of biogenic OAs. On the global scale, the model well predicted the particle number concentration in various environments. The microphysical module combined with the VBS simulated the universal distribution of organic components among the different aerosol populations. The model results strongly suggest the importance of anthropogenic organic species in aerosol particle formation and growth at polluted urban sites and over the whole globe.Aerosol microphysical processes are essential for the next generation of global and regional climate and air quality models to determine particle size distribution. The contribution of organic aerosols (OAs) to particle formation, mass, and number concentration is one of the major uncertainties in current models. A new global-regional nested aerosol model was developed to simulate detailed microphysical processes. The model combines an advanced particle microphysics (APM) module and a volatility basis set (VBS) OA module to calculate the kinetic condensation of low-volatility organic compounds and equilibrium partitioning of semi-volatile organic compounds in a 3-D framework using global-regional nested domain In addition to the condensation of sulfuric acid, the equilibrium partitioning of nitrate and ammonium, and the coagulation process of particles, the microphysical processes of the OAs are realistically represented in our new model. The model uses high-resolution size bins to calculate the size distribution of new particles formed through nucleation and subsequent growth. The multi-scale nesting enables the model to perform high-resolution simulations of the particle formation processes in the urban atmosphere in the background of regional and global environments. By using the nested domains, the model reasonably reproduced the OA components obtained from the analysis of aerosol mass spectrometry measurements through positive matrix factorization and the particle number size distribution in the megacity of Beijing during a period of approximately a month. Anthropogenic organic species accounted for 67 % of the OAs of secondary particles formed by nucleation and subsequent growth, which is considerably larger than that of biogenic OAs. On the global scale, the model well predicted the particle number concentration in various environments. The microphysical module combined with the VBS simulated the universal distribution of organic components among the different aerosol populations. The model results strongly suggest the importance of anthropogenic organic species in aerosol particle formation and growth at polluted urban sites and over the whole globe.Peer reviewe

Development, piloting and validation of the Recommending Cardiac Rehabilitation (ReCaRe) instrument

Background: Health practitioners’values, attitudes and beliefs largely determine their referrals to cardiac rehabilitation (CR).Objective:To develop and test the Recommending Cardiac Rehabilitation scale (ReCaRe), designed to assess health professionals attitudes, values and beliefs to CR referral. Methods: ReCaRe was appraised for: content validity (Delphi method, expert panel); interpretability and face validity (interview, health professionals); factor structure and internal consistency (survey, health professionals); and test-retest reliability (survey, health professionals). Normative scores were collated. Results: ReCaRe initially comprised 75 items. Initially, a Content Validity Index (CVI) was calculated for ratings of item relevance (CVI range; 0.271.0), which resulted in the removal of 19 items. After preliminary validation and psychometric testing, 34 items were factor-analysed (n= 24) providing a 17-item, four-factor scale: perceived severity and susceptibility (a= 0.93,k= 0.37); perceived service accessibility (a= 0.91,k= 0.67); perceived benefit(a= 0.97,k= 0.47); perceived barriers and attitudes (a= 0.82,k= 0.49). ReCaRe normative scores (n= 75) are reported.Conclusions:This psychometric analysis found ReCaRe to demonstrate good face validity, internal consistency and fair to substantial test-retest reliability. The next step is to validate these initial findings on a larger sample size to confirm whether ReCaRe can enable identification of factors impacting CR referra

Development of a synchronous recording and photo-stimulating electrode in multiple brain neurons

The investigation of brain networks and neural circuits involves the crucial aspects of observing and modulating neurophysiological activity. Recently, opto-electrodes have emerged as an efficient tool for electrophysiological recording and optogenetic stimulation, which has greatly facilitated the analysis of neural coding. However, implantation and electrode weight control have posed significant challenges in achieving long-term and multi-regional brain recording and stimulation. To address this issue, we have developed a mold and custom-printed circuit board-based opto-electrode. We report successful opto-electrode placement and high-quality electrophysiological recordings from the default mode network (DMN) of the mouse brain. This novel opto-electrode facilitates synchronous recording and stimulation in multiple brain regions and holds promise for advancing future research on neural circuits and networks

Home-Heart-Walk : evaluation of an intervention to promote and monitor physical activity

Chronic heart failure is a complex and multifaceted clinical syndrome and impacts adversely on health related quality of life and also increases the risk of hospitalisation and major acute coronary events. Self-care in chronic heart failure requires lifestyle changes, such as dietary modifications, fluid restriction, medication adherence and increasing physical activity. Enhancing self-care has been shown to result in better health outcomes and improved quality of life. Promoting better self-care is an important and effective strategy in chronic heart failure management. Exercise and physical activity are part of best practice recommendation. Despite compelling evidence to support the benefits of physical activity in improving functional capacity and quality of life, physical activity adherence remains low. Many people find following physical activity recommendations more difficult than following their medication regime, fluid restriction and diet. To date, the majority of interventions have focused on improving physical functioning of people living with CHF involving supervised, clinic based exercise programs although the benefits for home based programs is evident. Nevertheless, the impressive gains people have achieved through physical activity programs are often lost as many fail to maintain a physically active lifestyle after they complete the program.Based upon a comprehensive literature review and theoretical framework, the Home-Heart-Walk has been developed. The Home-Heart-Walk is a novel theoretically informed self-monitoring intervention, sought to promote physical functioning in people living with chronic heart failure. This model is a self-administered intervention adapted from the standard six minute walk test. It comprised six months of weekly Home-Heart-Walk and monthly telephone follow-up. This doctoral project evaluated the effect of the Home-Heart-Walk in promoting physical functioning in a group people with chronic heart failure.Based upon a comprehensive literature review and theoretical framework, the Home-Heart-Walk has been developed. The Home-Heart-Walk is a novel theoretically informed self-monitoring intervention, sought to promote physical functioning in people living with chronic heart failure. This model is a self-administered intervention adapted from the standard six minute walk test. It comprised six months of weekly Home-Heart-Walk and monthly telephone follow-up. This doctoral project evaluated the effect of the Home-Heart-Walk in promoting physical functioning in a group people with chronic heart failure.Participants were followed up at three months and six months. The primary outcome was the physical function domain of the Medical Outcome Study Short Form-36. Secondary outcomes included the Six Minute Walk Test (6MWT) distance, European Heart Failure Self-care Behaviour Scale, Bandura’s exercise self-efficacy, generic health related quality of life (Medical Outcome Study Short Form-36) and disease specific (Minnesota Living with Heart Failure Questionnaire) as well as Physical Activity Scale.This thesis presents the conceptual underpinnings of a theoretically derived intervention, clinical trial methodology and the interim analysis of the first 67 participants who have completed the six-month study. All participants’ data were analysed on the basis of the intention to treat principle. Despite there were no statistical or clinical significant difference observed between the intervention and the control group at six-month follow-up, there was a significant increase in the 6MWT distance over the six-month study period, in the intervention group (p=0.05). A trend of improved self-reported health related quality of life was also observed in the intervention group, with a slight decreased Minnesota Living with Heart Failure Questionnaire score (baseline: 45.4 [95% CI: 37.0-53.9]; three-month: 41.7 [95% CI: 32.6-50.9]) compared to the clinically meaningful deterioration (increased score) in the control group (baseline: 36.3 [95% CI: 27.8-44.7]; three-month: 43.9 [95% CI: 35.3-52.6]). The deterioration observed in control group was sustained at six-month follow-up. Similarly, score in self-care behaviour was also slightly decreased (improvement) (26.2 [95% CI: 23.4-29.0] to 24.0 [95% CI: 21.6-26.3]) compared to a slight increase (deterioration) in the control group (25.6 [95% CI: 22.9-28.5] to 26.5 [95% CI: 23.4-29.6]), over the study period.While results from this interim analysis will not allow conclusion to be made on the effectiveness of the Home-Heart-Walk, they have provided preliminary data and insights into the challenge of promoting physical functioning in people living with chronic heart failure. This study highlights the challenges of achieving long-term physical activity adherence for people living with CHF. This has been demonstrated in recruitment challenges, and the refractory dimension of increasing physical activity

Simulation of rock fragmentation induced by a tunnel boring machine disk cutter

A constitutive model based on the Johnson–Cook material model and the extended Drucker–Prager strength criterion was implemented in LS-DYNA to simulate the rock failure process induced by a single disk cutter of a tunnel boring machine. The normal, rolling, and side forces were determined by numerical tests. The simulation results showed that the normal and rolling forces increased with increasing penetration while the side force changed little. The normal force also increased under the conditions of confining pressures. The damage region of rock and cutting forces were also obtained by simulation of two disk cutters acting in tandem with different cutting spacings. The optimum ratio of cutter spacing to penetration depth determined from numerical modeling agrees well with that obtained by linear cutting machine tests. The average normal and rolling forces acting on the first cutter are slightly greater than those acting on the second when the cutting disk spacing is relatively small. The numerical modeling was verified to accurately capture the fragmentation of rock induced by disk cutter